UPSTREAM: io_uring: import 5.15-stable io_uring
No upstream commit exists.
This imports the io_uring codebase from 5.15.85, wholesale. Changes
from that code base:
- Drop IOCB_ALLOC_CACHE, we don't have that in 5.10.
- Drop MKDIRAT/SYMLINKAT/LINKAT. Would require further VFS backports,
and we don't support these in 5.10 to begin with.
- sock_from_file() old style calling convention.
- Use compat_get_bitmap() only for CONFIG_COMPAT=y
Change-Id: I7ce5226d6b39763ffc246fd6357cece9aafd4b59
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
(cherry picked from commit 788d0824269bef539fe31a785b1517882eafed93)
Bug: 268174392
Signed-off-by: Greg Kroah-Hartman <[email protected]>
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
new file mode 100644
index 0000000..473dbd1
--- /dev/null
+++ b/io_uring/io_uring.c
@@ -0,0 +1,10945 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Shared application/kernel submission and completion ring pairs, for
+ * supporting fast/efficient IO.
+ *
+ * A note on the read/write ordering memory barriers that are matched between
+ * the application and kernel side.
+ *
+ * After the application reads the CQ ring tail, it must use an
+ * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
+ * before writing the tail (using smp_load_acquire to read the tail will
+ * do). It also needs a smp_mb() before updating CQ head (ordering the
+ * entry load(s) with the head store), pairing with an implicit barrier
+ * through a control-dependency in io_get_cqe (smp_store_release to
+ * store head will do). Failure to do so could lead to reading invalid
+ * CQ entries.
+ *
+ * Likewise, the application must use an appropriate smp_wmb() before
+ * writing the SQ tail (ordering SQ entry stores with the tail store),
+ * which pairs with smp_load_acquire in io_get_sqring (smp_store_release
+ * to store the tail will do). And it needs a barrier ordering the SQ
+ * head load before writing new SQ entries (smp_load_acquire to read
+ * head will do).
+ *
+ * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
+ * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
+ * updating the SQ tail; a full memory barrier smp_mb() is needed
+ * between.
+ *
+ * Also see the examples in the liburing library:
+ *
+ * git://git.kernel.dk/liburing
+ *
+ * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
+ * from data shared between the kernel and application. This is done both
+ * for ordering purposes, but also to ensure that once a value is loaded from
+ * data that the application could potentially modify, it remains stable.
+ *
+ * Copyright (C) 2018-2019 Jens Axboe
+ * Copyright (c) 2018-2019 Christoph Hellwig
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/syscalls.h>
+#include <linux/compat.h>
+#include <net/compat.h>
+#include <linux/refcount.h>
+#include <linux/uio.h>
+#include <linux/bits.h>
+
+#include <linux/sched/signal.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/percpu.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/bvec.h>
+#include <linux/net.h>
+#include <net/sock.h>
+#include <net/af_unix.h>
+#include <net/scm.h>
+#include <linux/anon_inodes.h>
+#include <linux/sched/mm.h>
+#include <linux/uaccess.h>
+#include <linux/nospec.h>
+#include <linux/sizes.h>
+#include <linux/hugetlb.h>
+#include <linux/highmem.h>
+#include <linux/namei.h>
+#include <linux/fsnotify.h>
+#include <linux/fadvise.h>
+#include <linux/eventpoll.h>
+#include <linux/splice.h>
+#include <linux/task_work.h>
+#include <linux/pagemap.h>
+#include <linux/io_uring.h>
+#include <linux/tracehook.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "../fs/internal.h"
+#include "io-wq.h"
+
+#define IORING_MAX_ENTRIES 32768
+#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
+#define IORING_SQPOLL_CAP_ENTRIES_VALUE 8
+
+/* only define max */
+#define IORING_MAX_FIXED_FILES (1U << 15)
+#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
+ IORING_REGISTER_LAST + IORING_OP_LAST)
+
+#define IO_RSRC_TAG_TABLE_SHIFT (PAGE_SHIFT - 3)
+#define IO_RSRC_TAG_TABLE_MAX (1U << IO_RSRC_TAG_TABLE_SHIFT)
+#define IO_RSRC_TAG_TABLE_MASK (IO_RSRC_TAG_TABLE_MAX - 1)
+
+#define IORING_MAX_REG_BUFFERS (1U << 14)
+
+#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
+ IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
+ IOSQE_BUFFER_SELECT)
+#define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \
+ REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS)
+
+#define IO_TCTX_REFS_CACHE_NR (1U << 10)
+
+struct io_uring {
+ u32 head ____cacheline_aligned_in_smp;
+ u32 tail ____cacheline_aligned_in_smp;
+};
+
+/*
+ * This data is shared with the application through the mmap at offsets
+ * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
+ *
+ * The offsets to the member fields are published through struct
+ * io_sqring_offsets when calling io_uring_setup.
+ */
+struct io_rings {
+ /*
+ * Head and tail offsets into the ring; the offsets need to be
+ * masked to get valid indices.
+ *
+ * The kernel controls head of the sq ring and the tail of the cq ring,
+ * and the application controls tail of the sq ring and the head of the
+ * cq ring.
+ */
+ struct io_uring sq, cq;
+ /*
+ * Bitmasks to apply to head and tail offsets (constant, equals
+ * ring_entries - 1)
+ */
+ u32 sq_ring_mask, cq_ring_mask;
+ /* Ring sizes (constant, power of 2) */
+ u32 sq_ring_entries, cq_ring_entries;
+ /*
+ * Number of invalid entries dropped by the kernel due to
+ * invalid index stored in array
+ *
+ * Written by the kernel, shouldn't be modified by the
+ * application (i.e. get number of "new events" by comparing to
+ * cached value).
+ *
+ * After a new SQ head value was read by the application this
+ * counter includes all submissions that were dropped reaching
+ * the new SQ head (and possibly more).
+ */
+ u32 sq_dropped;
+ /*
+ * Runtime SQ flags
+ *
+ * Written by the kernel, shouldn't be modified by the
+ * application.
+ *
+ * The application needs a full memory barrier before checking
+ * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
+ */
+ u32 sq_flags;
+ /*
+ * Runtime CQ flags
+ *
+ * Written by the application, shouldn't be modified by the
+ * kernel.
+ */
+ u32 cq_flags;
+ /*
+ * Number of completion events lost because the queue was full;
+ * this should be avoided by the application by making sure
+ * there are not more requests pending than there is space in
+ * the completion queue.
+ *
+ * Written by the kernel, shouldn't be modified by the
+ * application (i.e. get number of "new events" by comparing to
+ * cached value).
+ *
+ * As completion events come in out of order this counter is not
+ * ordered with any other data.
+ */
+ u32 cq_overflow;
+ /*
+ * Ring buffer of completion events.
+ *
+ * The kernel writes completion events fresh every time they are
+ * produced, so the application is allowed to modify pending
+ * entries.
+ */
+ struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
+};
+
+enum io_uring_cmd_flags {
+ IO_URING_F_NONBLOCK = 1,
+ IO_URING_F_COMPLETE_DEFER = 2,
+};
+
+struct io_mapped_ubuf {
+ u64 ubuf;
+ u64 ubuf_end;
+ unsigned int nr_bvecs;
+ unsigned long acct_pages;
+ struct bio_vec bvec[];
+};
+
+struct io_ring_ctx;
+
+struct io_overflow_cqe {
+ struct io_uring_cqe cqe;
+ struct list_head list;
+};
+
+struct io_fixed_file {
+ /* file * with additional FFS_* flags */
+ unsigned long file_ptr;
+};
+
+struct io_rsrc_put {
+ struct list_head list;
+ u64 tag;
+ union {
+ void *rsrc;
+ struct file *file;
+ struct io_mapped_ubuf *buf;
+ };
+};
+
+struct io_file_table {
+ struct io_fixed_file *files;
+};
+
+struct io_rsrc_node {
+ struct percpu_ref refs;
+ struct list_head node;
+ struct list_head rsrc_list;
+ struct io_rsrc_data *rsrc_data;
+ struct llist_node llist;
+ bool done;
+};
+
+typedef void (rsrc_put_fn)(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
+
+struct io_rsrc_data {
+ struct io_ring_ctx *ctx;
+
+ u64 **tags;
+ unsigned int nr;
+ rsrc_put_fn *do_put;
+ atomic_t refs;
+ struct completion done;
+ bool quiesce;
+};
+
+struct io_buffer {
+ struct list_head list;
+ __u64 addr;
+ __u32 len;
+ __u16 bid;
+};
+
+struct io_restriction {
+ DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
+ DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
+ u8 sqe_flags_allowed;
+ u8 sqe_flags_required;
+ bool registered;
+};
+
+enum {
+ IO_SQ_THREAD_SHOULD_STOP = 0,
+ IO_SQ_THREAD_SHOULD_PARK,
+};
+
+struct io_sq_data {
+ refcount_t refs;
+ atomic_t park_pending;
+ struct mutex lock;
+
+ /* ctx's that are using this sqd */
+ struct list_head ctx_list;
+
+ struct task_struct *thread;
+ struct wait_queue_head wait;
+
+ unsigned sq_thread_idle;
+ int sq_cpu;
+ pid_t task_pid;
+ pid_t task_tgid;
+
+ unsigned long state;
+ struct completion exited;
+};
+
+#define IO_COMPL_BATCH 32
+#define IO_REQ_CACHE_SIZE 32
+#define IO_REQ_ALLOC_BATCH 8
+
+struct io_submit_link {
+ struct io_kiocb *head;
+ struct io_kiocb *last;
+};
+
+struct io_submit_state {
+ struct blk_plug plug;
+ struct io_submit_link link;
+
+ /*
+ * io_kiocb alloc cache
+ */
+ void *reqs[IO_REQ_CACHE_SIZE];
+ unsigned int free_reqs;
+
+ bool plug_started;
+
+ /*
+ * Batch completion logic
+ */
+ struct io_kiocb *compl_reqs[IO_COMPL_BATCH];
+ unsigned int compl_nr;
+ /* inline/task_work completion list, under ->uring_lock */
+ struct list_head free_list;
+
+ unsigned int ios_left;
+};
+
+struct io_ring_ctx {
+ /* const or read-mostly hot data */
+ struct {
+ struct percpu_ref refs;
+
+ struct io_rings *rings;
+ unsigned int flags;
+ unsigned int compat: 1;
+ unsigned int drain_next: 1;
+ unsigned int eventfd_async: 1;
+ unsigned int restricted: 1;
+ unsigned int off_timeout_used: 1;
+ unsigned int drain_active: 1;
+ } ____cacheline_aligned_in_smp;
+
+ /* submission data */
+ struct {
+ struct mutex uring_lock;
+
+ /*
+ * Ring buffer of indices into array of io_uring_sqe, which is
+ * mmapped by the application using the IORING_OFF_SQES offset.
+ *
+ * This indirection could e.g. be used to assign fixed
+ * io_uring_sqe entries to operations and only submit them to
+ * the queue when needed.
+ *
+ * The kernel modifies neither the indices array nor the entries
+ * array.
+ */
+ u32 *sq_array;
+ struct io_uring_sqe *sq_sqes;
+ unsigned cached_sq_head;
+ unsigned sq_entries;
+ struct list_head defer_list;
+
+ /*
+ * Fixed resources fast path, should be accessed only under
+ * uring_lock, and updated through io_uring_register(2)
+ */
+ struct io_rsrc_node *rsrc_node;
+ struct io_file_table file_table;
+ unsigned nr_user_files;
+ unsigned nr_user_bufs;
+ struct io_mapped_ubuf **user_bufs;
+
+ struct io_submit_state submit_state;
+ struct list_head timeout_list;
+ struct list_head ltimeout_list;
+ struct list_head cq_overflow_list;
+ struct xarray io_buffers;
+ struct xarray personalities;
+ u32 pers_next;
+ unsigned sq_thread_idle;
+ } ____cacheline_aligned_in_smp;
+
+ /* IRQ completion list, under ->completion_lock */
+ struct list_head locked_free_list;
+ unsigned int locked_free_nr;
+
+ const struct cred *sq_creds; /* cred used for __io_sq_thread() */
+ struct io_sq_data *sq_data; /* if using sq thread polling */
+
+ struct wait_queue_head sqo_sq_wait;
+ struct list_head sqd_list;
+
+ unsigned long check_cq_overflow;
+
+ struct {
+ unsigned cached_cq_tail;
+ unsigned cq_entries;
+ struct eventfd_ctx *cq_ev_fd;
+ struct wait_queue_head poll_wait;
+ struct wait_queue_head cq_wait;
+ unsigned cq_extra;
+ atomic_t cq_timeouts;
+ unsigned cq_last_tm_flush;
+ } ____cacheline_aligned_in_smp;
+
+ struct {
+ spinlock_t completion_lock;
+
+ spinlock_t timeout_lock;
+
+ /*
+ * ->iopoll_list is protected by the ctx->uring_lock for
+ * io_uring instances that don't use IORING_SETUP_SQPOLL.
+ * For SQPOLL, only the single threaded io_sq_thread() will
+ * manipulate the list, hence no extra locking is needed there.
+ */
+ struct list_head iopoll_list;
+ struct hlist_head *cancel_hash;
+ unsigned cancel_hash_bits;
+ bool poll_multi_queue;
+ } ____cacheline_aligned_in_smp;
+
+ struct io_restriction restrictions;
+
+ /* slow path rsrc auxilary data, used by update/register */
+ struct {
+ struct io_rsrc_node *rsrc_backup_node;
+ struct io_mapped_ubuf *dummy_ubuf;
+ struct io_rsrc_data *file_data;
+ struct io_rsrc_data *buf_data;
+
+ struct delayed_work rsrc_put_work;
+ struct llist_head rsrc_put_llist;
+ struct list_head rsrc_ref_list;
+ spinlock_t rsrc_ref_lock;
+ };
+
+ /* Keep this last, we don't need it for the fast path */
+ struct {
+ #if defined(CONFIG_UNIX)
+ struct socket *ring_sock;
+ #endif
+ /* hashed buffered write serialization */
+ struct io_wq_hash *hash_map;
+
+ /* Only used for accounting purposes */
+ struct user_struct *user;
+ struct mm_struct *mm_account;
+
+ /* ctx exit and cancelation */
+ struct llist_head fallback_llist;
+ struct delayed_work fallback_work;
+ struct work_struct exit_work;
+ struct list_head tctx_list;
+ struct completion ref_comp;
+ u32 iowq_limits[2];
+ bool iowq_limits_set;
+ };
+};
+
+struct io_uring_task {
+ /* submission side */
+ int cached_refs;
+ struct xarray xa;
+ struct wait_queue_head wait;
+ const struct io_ring_ctx *last;
+ struct io_wq *io_wq;
+ struct percpu_counter inflight;
+ atomic_t inflight_tracked;
+ atomic_t in_idle;
+
+ spinlock_t task_lock;
+ struct io_wq_work_list task_list;
+ struct callback_head task_work;
+ bool task_running;
+};
+
+/*
+ * First field must be the file pointer in all the
+ * iocb unions! See also 'struct kiocb' in <linux/fs.h>
+ */
+struct io_poll_iocb {
+ struct file *file;
+ struct wait_queue_head *head;
+ __poll_t events;
+ struct wait_queue_entry wait;
+};
+
+struct io_poll_update {
+ struct file *file;
+ u64 old_user_data;
+ u64 new_user_data;
+ __poll_t events;
+ bool update_events;
+ bool update_user_data;
+};
+
+struct io_close {
+ struct file *file;
+ int fd;
+ u32 file_slot;
+};
+
+struct io_timeout_data {
+ struct io_kiocb *req;
+ struct hrtimer timer;
+ struct timespec64 ts;
+ enum hrtimer_mode mode;
+ u32 flags;
+};
+
+struct io_accept {
+ struct file *file;
+ struct sockaddr __user *addr;
+ int __user *addr_len;
+ int flags;
+ u32 file_slot;
+ unsigned long nofile;
+};
+
+struct io_sync {
+ struct file *file;
+ loff_t len;
+ loff_t off;
+ int flags;
+ int mode;
+};
+
+struct io_cancel {
+ struct file *file;
+ u64 addr;
+};
+
+struct io_timeout {
+ struct file *file;
+ u32 off;
+ u32 target_seq;
+ struct list_head list;
+ /* head of the link, used by linked timeouts only */
+ struct io_kiocb *head;
+ /* for linked completions */
+ struct io_kiocb *prev;
+};
+
+struct io_timeout_rem {
+ struct file *file;
+ u64 addr;
+
+ /* timeout update */
+ struct timespec64 ts;
+ u32 flags;
+ bool ltimeout;
+};
+
+struct io_rw {
+ /* NOTE: kiocb has the file as the first member, so don't do it here */
+ struct kiocb kiocb;
+ u64 addr;
+ u64 len;
+};
+
+struct io_connect {
+ struct file *file;
+ struct sockaddr __user *addr;
+ int addr_len;
+};
+
+struct io_sr_msg {
+ struct file *file;
+ union {
+ struct compat_msghdr __user *umsg_compat;
+ struct user_msghdr __user *umsg;
+ void __user *buf;
+ };
+ int msg_flags;
+ int bgid;
+ size_t len;
+ struct io_buffer *kbuf;
+};
+
+struct io_open {
+ struct file *file;
+ int dfd;
+ u32 file_slot;
+ struct filename *filename;
+ struct open_how how;
+ unsigned long nofile;
+};
+
+struct io_rsrc_update {
+ struct file *file;
+ u64 arg;
+ u32 nr_args;
+ u32 offset;
+};
+
+struct io_fadvise {
+ struct file *file;
+ u64 offset;
+ u32 len;
+ u32 advice;
+};
+
+struct io_madvise {
+ struct file *file;
+ u64 addr;
+ u32 len;
+ u32 advice;
+};
+
+struct io_epoll {
+ struct file *file;
+ int epfd;
+ int op;
+ int fd;
+ struct epoll_event event;
+};
+
+struct io_splice {
+ struct file *file_out;
+ loff_t off_out;
+ loff_t off_in;
+ u64 len;
+ int splice_fd_in;
+ unsigned int flags;
+};
+
+struct io_provide_buf {
+ struct file *file;
+ __u64 addr;
+ __u32 len;
+ __u32 bgid;
+ __u16 nbufs;
+ __u16 bid;
+};
+
+struct io_statx {
+ struct file *file;
+ int dfd;
+ unsigned int mask;
+ unsigned int flags;
+ const char __user *filename;
+ struct statx __user *buffer;
+};
+
+struct io_shutdown {
+ struct file *file;
+ int how;
+};
+
+struct io_rename {
+ struct file *file;
+ int old_dfd;
+ int new_dfd;
+ struct filename *oldpath;
+ struct filename *newpath;
+ int flags;
+};
+
+struct io_unlink {
+ struct file *file;
+ int dfd;
+ int flags;
+ struct filename *filename;
+};
+
+struct io_mkdir {
+ struct file *file;
+ int dfd;
+ umode_t mode;
+ struct filename *filename;
+};
+
+struct io_symlink {
+ struct file *file;
+ int new_dfd;
+ struct filename *oldpath;
+ struct filename *newpath;
+};
+
+struct io_hardlink {
+ struct file *file;
+ int old_dfd;
+ int new_dfd;
+ struct filename *oldpath;
+ struct filename *newpath;
+ int flags;
+};
+
+struct io_completion {
+ struct file *file;
+ u32 cflags;
+};
+
+struct io_async_connect {
+ struct sockaddr_storage address;
+};
+
+struct io_async_msghdr {
+ struct iovec fast_iov[UIO_FASTIOV];
+ /* points to an allocated iov, if NULL we use fast_iov instead */
+ struct iovec *free_iov;
+ struct sockaddr __user *uaddr;
+ struct msghdr msg;
+ struct sockaddr_storage addr;
+};
+
+struct io_async_rw {
+ struct iovec fast_iov[UIO_FASTIOV];
+ const struct iovec *free_iovec;
+ struct iov_iter iter;
+ struct iov_iter_state iter_state;
+ size_t bytes_done;
+ struct wait_page_queue wpq;
+};
+
+enum {
+ REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
+ REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
+ REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
+ REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
+ REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
+ REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
+
+ /* first byte is taken by user flags, shift it to not overlap */
+ REQ_F_FAIL_BIT = 8,
+ REQ_F_INFLIGHT_BIT,
+ REQ_F_CUR_POS_BIT,
+ REQ_F_NOWAIT_BIT,
+ REQ_F_LINK_TIMEOUT_BIT,
+ REQ_F_NEED_CLEANUP_BIT,
+ REQ_F_POLLED_BIT,
+ REQ_F_BUFFER_SELECTED_BIT,
+ REQ_F_COMPLETE_INLINE_BIT,
+ REQ_F_REISSUE_BIT,
+ REQ_F_CREDS_BIT,
+ REQ_F_REFCOUNT_BIT,
+ REQ_F_ARM_LTIMEOUT_BIT,
+ /* keep async read/write and isreg together and in order */
+ REQ_F_NOWAIT_READ_BIT,
+ REQ_F_NOWAIT_WRITE_BIT,
+ REQ_F_ISREG_BIT,
+
+ /* not a real bit, just to check we're not overflowing the space */
+ __REQ_F_LAST_BIT,
+};
+
+enum {
+ /* ctx owns file */
+ REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
+ /* drain existing IO first */
+ REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
+ /* linked sqes */
+ REQ_F_LINK = BIT(REQ_F_LINK_BIT),
+ /* doesn't sever on completion < 0 */
+ REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
+ /* IOSQE_ASYNC */
+ REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
+ /* IOSQE_BUFFER_SELECT */
+ REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
+
+ /* fail rest of links */
+ REQ_F_FAIL = BIT(REQ_F_FAIL_BIT),
+ /* on inflight list, should be cancelled and waited on exit reliably */
+ REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
+ /* read/write uses file position */
+ REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
+ /* must not punt to workers */
+ REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
+ /* has or had linked timeout */
+ REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
+ /* needs cleanup */
+ REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
+ /* already went through poll handler */
+ REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
+ /* buffer already selected */
+ REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
+ /* completion is deferred through io_comp_state */
+ REQ_F_COMPLETE_INLINE = BIT(REQ_F_COMPLETE_INLINE_BIT),
+ /* caller should reissue async */
+ REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT),
+ /* supports async reads */
+ REQ_F_NOWAIT_READ = BIT(REQ_F_NOWAIT_READ_BIT),
+ /* supports async writes */
+ REQ_F_NOWAIT_WRITE = BIT(REQ_F_NOWAIT_WRITE_BIT),
+ /* regular file */
+ REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
+ /* has creds assigned */
+ REQ_F_CREDS = BIT(REQ_F_CREDS_BIT),
+ /* skip refcounting if not set */
+ REQ_F_REFCOUNT = BIT(REQ_F_REFCOUNT_BIT),
+ /* there is a linked timeout that has to be armed */
+ REQ_F_ARM_LTIMEOUT = BIT(REQ_F_ARM_LTIMEOUT_BIT),
+};
+
+struct async_poll {
+ struct io_poll_iocb poll;
+ struct io_poll_iocb *double_poll;
+};
+
+typedef void (*io_req_tw_func_t)(struct io_kiocb *req, bool *locked);
+
+struct io_task_work {
+ union {
+ struct io_wq_work_node node;
+ struct llist_node fallback_node;
+ };
+ io_req_tw_func_t func;
+};
+
+enum {
+ IORING_RSRC_FILE = 0,
+ IORING_RSRC_BUFFER = 1,
+};
+
+/*
+ * NOTE! Each of the iocb union members has the file pointer
+ * as the first entry in their struct definition. So you can
+ * access the file pointer through any of the sub-structs,
+ * or directly as just 'ki_filp' in this struct.
+ */
+struct io_kiocb {
+ union {
+ struct file *file;
+ struct io_rw rw;
+ struct io_poll_iocb poll;
+ struct io_poll_update poll_update;
+ struct io_accept accept;
+ struct io_sync sync;
+ struct io_cancel cancel;
+ struct io_timeout timeout;
+ struct io_timeout_rem timeout_rem;
+ struct io_connect connect;
+ struct io_sr_msg sr_msg;
+ struct io_open open;
+ struct io_close close;
+ struct io_rsrc_update rsrc_update;
+ struct io_fadvise fadvise;
+ struct io_madvise madvise;
+ struct io_epoll epoll;
+ struct io_splice splice;
+ struct io_provide_buf pbuf;
+ struct io_statx statx;
+ struct io_shutdown shutdown;
+ struct io_rename rename;
+ struct io_unlink unlink;
+ struct io_mkdir mkdir;
+ struct io_symlink symlink;
+ struct io_hardlink hardlink;
+ /* use only after cleaning per-op data, see io_clean_op() */
+ struct io_completion compl;
+ };
+
+ /* opcode allocated if it needs to store data for async defer */
+ void *async_data;
+ u8 opcode;
+ /* polled IO has completed */
+ u8 iopoll_completed;
+
+ u16 buf_index;
+ u32 result;
+
+ struct io_ring_ctx *ctx;
+ unsigned int flags;
+ atomic_t refs;
+ struct task_struct *task;
+ u64 user_data;
+
+ struct io_kiocb *link;
+ struct percpu_ref *fixed_rsrc_refs;
+
+ /* used with ctx->iopoll_list with reads/writes */
+ struct list_head inflight_entry;
+ struct io_task_work io_task_work;
+ /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
+ struct hlist_node hash_node;
+ struct async_poll *apoll;
+ struct io_wq_work work;
+ const struct cred *creds;
+
+ /* store used ubuf, so we can prevent reloading */
+ struct io_mapped_ubuf *imu;
+ /* stores selected buf, valid IFF REQ_F_BUFFER_SELECTED is set */
+ struct io_buffer *kbuf;
+ atomic_t poll_refs;
+};
+
+struct io_tctx_node {
+ struct list_head ctx_node;
+ struct task_struct *task;
+ struct io_ring_ctx *ctx;
+};
+
+struct io_defer_entry {
+ struct list_head list;
+ struct io_kiocb *req;
+ u32 seq;
+};
+
+struct io_op_def {
+ /* needs req->file assigned */
+ unsigned needs_file : 1;
+ /* hash wq insertion if file is a regular file */
+ unsigned hash_reg_file : 1;
+ /* unbound wq insertion if file is a non-regular file */
+ unsigned unbound_nonreg_file : 1;
+ /* opcode is not supported by this kernel */
+ unsigned not_supported : 1;
+ /* set if opcode supports polled "wait" */
+ unsigned pollin : 1;
+ unsigned pollout : 1;
+ /* op supports buffer selection */
+ unsigned buffer_select : 1;
+ /* do prep async if is going to be punted */
+ unsigned needs_async_setup : 1;
+ /* should block plug */
+ unsigned plug : 1;
+ /* size of async data needed, if any */
+ unsigned short async_size;
+};
+
+static const struct io_op_def io_op_defs[] = {
+ [IORING_OP_NOP] = {},
+ [IORING_OP_READV] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .buffer_select = 1,
+ .needs_async_setup = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_WRITEV] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .needs_async_setup = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_FSYNC] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_READ_FIXED] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_WRITE_FIXED] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_POLL_ADD] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ [IORING_OP_POLL_REMOVE] = {},
+ [IORING_OP_SYNC_FILE_RANGE] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_SENDMSG] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .needs_async_setup = 1,
+ .async_size = sizeof(struct io_async_msghdr),
+ },
+ [IORING_OP_RECVMSG] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .buffer_select = 1,
+ .needs_async_setup = 1,
+ .async_size = sizeof(struct io_async_msghdr),
+ },
+ [IORING_OP_TIMEOUT] = {
+ .async_size = sizeof(struct io_timeout_data),
+ },
+ [IORING_OP_TIMEOUT_REMOVE] = {
+ /* used by timeout updates' prep() */
+ },
+ [IORING_OP_ACCEPT] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ },
+ [IORING_OP_ASYNC_CANCEL] = {},
+ [IORING_OP_LINK_TIMEOUT] = {
+ .async_size = sizeof(struct io_timeout_data),
+ },
+ [IORING_OP_CONNECT] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .needs_async_setup = 1,
+ .async_size = sizeof(struct io_async_connect),
+ },
+ [IORING_OP_FALLOCATE] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_OPENAT] = {},
+ [IORING_OP_CLOSE] = {},
+ [IORING_OP_FILES_UPDATE] = {},
+ [IORING_OP_STATX] = {},
+ [IORING_OP_READ] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .buffer_select = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_WRITE] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ .plug = 1,
+ .async_size = sizeof(struct io_async_rw),
+ },
+ [IORING_OP_FADVISE] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_MADVISE] = {},
+ [IORING_OP_SEND] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollout = 1,
+ },
+ [IORING_OP_RECV] = {
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ .pollin = 1,
+ .buffer_select = 1,
+ },
+ [IORING_OP_OPENAT2] = {
+ },
+ [IORING_OP_EPOLL_CTL] = {
+ .unbound_nonreg_file = 1,
+ },
+ [IORING_OP_SPLICE] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ [IORING_OP_PROVIDE_BUFFERS] = {},
+ [IORING_OP_REMOVE_BUFFERS] = {},
+ [IORING_OP_TEE] = {
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ [IORING_OP_SHUTDOWN] = {
+ .needs_file = 1,
+ },
+ [IORING_OP_RENAMEAT] = {},
+ [IORING_OP_UNLINKAT] = {},
+};
+
+/* requests with any of those set should undergo io_disarm_next() */
+#define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL)
+
+static bool io_disarm_next(struct io_kiocb *req);
+static void io_uring_del_tctx_node(unsigned long index);
+static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
+ struct task_struct *task,
+ bool cancel_all);
+static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
+
+static void io_fill_cqe_req(struct io_kiocb *req, s32 res, u32 cflags);
+
+static void io_put_req(struct io_kiocb *req);
+static void io_put_req_deferred(struct io_kiocb *req);
+static void io_dismantle_req(struct io_kiocb *req);
+static void io_queue_linked_timeout(struct io_kiocb *req);
+static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type,
+ struct io_uring_rsrc_update2 *up,
+ unsigned nr_args);
+static void io_clean_op(struct io_kiocb *req);
+static struct file *io_file_get(struct io_ring_ctx *ctx,
+ struct io_kiocb *req, int fd, bool fixed);
+static void __io_queue_sqe(struct io_kiocb *req);
+static void io_rsrc_put_work(struct work_struct *work);
+
+static void io_req_task_queue(struct io_kiocb *req);
+static void io_submit_flush_completions(struct io_ring_ctx *ctx);
+static int io_req_prep_async(struct io_kiocb *req);
+
+static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
+ unsigned int issue_flags, u32 slot_index);
+static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags);
+
+static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer);
+
+static struct kmem_cache *req_cachep;
+
+static const struct file_operations io_uring_fops;
+
+struct sock *io_uring_get_socket(struct file *file)
+{
+#if defined(CONFIG_UNIX)
+ if (file->f_op == &io_uring_fops) {
+ struct io_ring_ctx *ctx = file->private_data;
+
+ return ctx->ring_sock->sk;
+ }
+#endif
+ return NULL;
+}
+EXPORT_SYMBOL(io_uring_get_socket);
+
+static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
+{
+ if (!*locked) {
+ mutex_lock(&ctx->uring_lock);
+ *locked = true;
+ }
+}
+
+#define io_for_each_link(pos, head) \
+ for (pos = (head); pos; pos = pos->link)
+
+/*
+ * Shamelessly stolen from the mm implementation of page reference checking,
+ * see commit f958d7b528b1 for details.
+ */
+#define req_ref_zero_or_close_to_overflow(req) \
+ ((unsigned int) atomic_read(&(req->refs)) + 127u <= 127u)
+
+static inline bool req_ref_inc_not_zero(struct io_kiocb *req)
+{
+ WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT));
+ return atomic_inc_not_zero(&req->refs);
+}
+
+static inline bool req_ref_put_and_test(struct io_kiocb *req)
+{
+ if (likely(!(req->flags & REQ_F_REFCOUNT)))
+ return true;
+
+ WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
+ return atomic_dec_and_test(&req->refs);
+}
+
+static inline void req_ref_get(struct io_kiocb *req)
+{
+ WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT));
+ WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
+ atomic_inc(&req->refs);
+}
+
+static inline void __io_req_set_refcount(struct io_kiocb *req, int nr)
+{
+ if (!(req->flags & REQ_F_REFCOUNT)) {
+ req->flags |= REQ_F_REFCOUNT;
+ atomic_set(&req->refs, nr);
+ }
+}
+
+static inline void io_req_set_refcount(struct io_kiocb *req)
+{
+ __io_req_set_refcount(req, 1);
+}
+
+static inline void io_req_set_rsrc_node(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (!req->fixed_rsrc_refs) {
+ req->fixed_rsrc_refs = &ctx->rsrc_node->refs;
+ percpu_ref_get(req->fixed_rsrc_refs);
+ }
+}
+
+static void io_refs_resurrect(struct percpu_ref *ref, struct completion *compl)
+{
+ bool got = percpu_ref_tryget(ref);
+
+ /* already at zero, wait for ->release() */
+ if (!got)
+ wait_for_completion(compl);
+ percpu_ref_resurrect(ref);
+ if (got)
+ percpu_ref_put(ref);
+}
+
+static bool io_match_task(struct io_kiocb *head, struct task_struct *task,
+ bool cancel_all)
+ __must_hold(&req->ctx->timeout_lock)
+{
+ struct io_kiocb *req;
+
+ if (task && head->task != task)
+ return false;
+ if (cancel_all)
+ return true;
+
+ io_for_each_link(req, head) {
+ if (req->flags & REQ_F_INFLIGHT)
+ return true;
+ }
+ return false;
+}
+
+static bool io_match_linked(struct io_kiocb *head)
+{
+ struct io_kiocb *req;
+
+ io_for_each_link(req, head) {
+ if (req->flags & REQ_F_INFLIGHT)
+ return true;
+ }
+ return false;
+}
+
+/*
+ * As io_match_task() but protected against racing with linked timeouts.
+ * User must not hold timeout_lock.
+ */
+static bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
+ bool cancel_all)
+{
+ bool matched;
+
+ if (task && head->task != task)
+ return false;
+ if (cancel_all)
+ return true;
+
+ if (head->flags & REQ_F_LINK_TIMEOUT) {
+ struct io_ring_ctx *ctx = head->ctx;
+
+ /* protect against races with linked timeouts */
+ spin_lock_irq(&ctx->timeout_lock);
+ matched = io_match_linked(head);
+ spin_unlock_irq(&ctx->timeout_lock);
+ } else {
+ matched = io_match_linked(head);
+ }
+ return matched;
+}
+
+static inline void req_set_fail(struct io_kiocb *req)
+{
+ req->flags |= REQ_F_FAIL;
+}
+
+static inline void req_fail_link_node(struct io_kiocb *req, int res)
+{
+ req_set_fail(req);
+ req->result = res;
+}
+
+static void io_ring_ctx_ref_free(struct percpu_ref *ref)
+{
+ struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
+
+ complete(&ctx->ref_comp);
+}
+
+static inline bool io_is_timeout_noseq(struct io_kiocb *req)
+{
+ return !req->timeout.off;
+}
+
+static void io_fallback_req_func(struct work_struct *work)
+{
+ struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
+ fallback_work.work);
+ struct llist_node *node = llist_del_all(&ctx->fallback_llist);
+ struct io_kiocb *req, *tmp;
+ bool locked = false;
+
+ percpu_ref_get(&ctx->refs);
+ llist_for_each_entry_safe(req, tmp, node, io_task_work.fallback_node)
+ req->io_task_work.func(req, &locked);
+
+ if (locked) {
+ if (ctx->submit_state.compl_nr)
+ io_submit_flush_completions(ctx);
+ mutex_unlock(&ctx->uring_lock);
+ }
+ percpu_ref_put(&ctx->refs);
+
+}
+
+static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
+{
+ struct io_ring_ctx *ctx;
+ int hash_bits;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return NULL;
+
+ /*
+ * Use 5 bits less than the max cq entries, that should give us around
+ * 32 entries per hash list if totally full and uniformly spread.
+ */
+ hash_bits = ilog2(p->cq_entries);
+ hash_bits -= 5;
+ if (hash_bits <= 0)
+ hash_bits = 1;
+ ctx->cancel_hash_bits = hash_bits;
+ ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
+ GFP_KERNEL);
+ if (!ctx->cancel_hash)
+ goto err;
+ __hash_init(ctx->cancel_hash, 1U << hash_bits);
+
+ ctx->dummy_ubuf = kzalloc(sizeof(*ctx->dummy_ubuf), GFP_KERNEL);
+ if (!ctx->dummy_ubuf)
+ goto err;
+ /* set invalid range, so io_import_fixed() fails meeting it */
+ ctx->dummy_ubuf->ubuf = -1UL;
+
+ if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
+ PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
+ goto err;
+
+ ctx->flags = p->flags;
+ init_waitqueue_head(&ctx->sqo_sq_wait);
+ INIT_LIST_HEAD(&ctx->sqd_list);
+ init_waitqueue_head(&ctx->poll_wait);
+ INIT_LIST_HEAD(&ctx->cq_overflow_list);
+ init_completion(&ctx->ref_comp);
+ xa_init_flags(&ctx->io_buffers, XA_FLAGS_ALLOC1);
+ xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
+ mutex_init(&ctx->uring_lock);
+ init_waitqueue_head(&ctx->cq_wait);
+ spin_lock_init(&ctx->completion_lock);
+ spin_lock_init(&ctx->timeout_lock);
+ INIT_LIST_HEAD(&ctx->iopoll_list);
+ INIT_LIST_HEAD(&ctx->defer_list);
+ INIT_LIST_HEAD(&ctx->timeout_list);
+ INIT_LIST_HEAD(&ctx->ltimeout_list);
+ spin_lock_init(&ctx->rsrc_ref_lock);
+ INIT_LIST_HEAD(&ctx->rsrc_ref_list);
+ INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work);
+ init_llist_head(&ctx->rsrc_put_llist);
+ INIT_LIST_HEAD(&ctx->tctx_list);
+ INIT_LIST_HEAD(&ctx->submit_state.free_list);
+ INIT_LIST_HEAD(&ctx->locked_free_list);
+ INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func);
+ return ctx;
+err:
+ kfree(ctx->dummy_ubuf);
+ kfree(ctx->cancel_hash);
+ kfree(ctx);
+ return NULL;
+}
+
+static void io_account_cq_overflow(struct io_ring_ctx *ctx)
+{
+ struct io_rings *r = ctx->rings;
+
+ WRITE_ONCE(r->cq_overflow, READ_ONCE(r->cq_overflow) + 1);
+ ctx->cq_extra--;
+}
+
+static bool req_need_defer(struct io_kiocb *req, u32 seq)
+{
+ if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
+ struct io_ring_ctx *ctx = req->ctx;
+
+ return seq + READ_ONCE(ctx->cq_extra) != ctx->cached_cq_tail;
+ }
+
+ return false;
+}
+
+#define FFS_ASYNC_READ 0x1UL
+#define FFS_ASYNC_WRITE 0x2UL
+#ifdef CONFIG_64BIT
+#define FFS_ISREG 0x4UL
+#else
+#define FFS_ISREG 0x0UL
+#endif
+#define FFS_MASK ~(FFS_ASYNC_READ|FFS_ASYNC_WRITE|FFS_ISREG)
+
+static inline bool io_req_ffs_set(struct io_kiocb *req)
+{
+ return IS_ENABLED(CONFIG_64BIT) && (req->flags & REQ_F_FIXED_FILE);
+}
+
+static void io_req_track_inflight(struct io_kiocb *req)
+{
+ if (!(req->flags & REQ_F_INFLIGHT)) {
+ req->flags |= REQ_F_INFLIGHT;
+ atomic_inc(&req->task->io_uring->inflight_tracked);
+ }
+}
+
+static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req)
+{
+ if (WARN_ON_ONCE(!req->link))
+ return NULL;
+
+ req->flags &= ~REQ_F_ARM_LTIMEOUT;
+ req->flags |= REQ_F_LINK_TIMEOUT;
+
+ /* linked timeouts should have two refs once prep'ed */
+ io_req_set_refcount(req);
+ __io_req_set_refcount(req->link, 2);
+ return req->link;
+}
+
+static inline struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
+{
+ if (likely(!(req->flags & REQ_F_ARM_LTIMEOUT)))
+ return NULL;
+ return __io_prep_linked_timeout(req);
+}
+
+static void io_prep_async_work(struct io_kiocb *req)
+{
+ const struct io_op_def *def = &io_op_defs[req->opcode];
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (!(req->flags & REQ_F_CREDS)) {
+ req->flags |= REQ_F_CREDS;
+ req->creds = get_current_cred();
+ }
+
+ req->work.list.next = NULL;
+ req->work.flags = 0;
+ if (req->flags & REQ_F_FORCE_ASYNC)
+ req->work.flags |= IO_WQ_WORK_CONCURRENT;
+
+ if (req->flags & REQ_F_ISREG) {
+ if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
+ io_wq_hash_work(&req->work, file_inode(req->file));
+ } else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) {
+ if (def->unbound_nonreg_file)
+ req->work.flags |= IO_WQ_WORK_UNBOUND;
+ }
+}
+
+static void io_prep_async_link(struct io_kiocb *req)
+{
+ struct io_kiocb *cur;
+
+ if (req->flags & REQ_F_LINK_TIMEOUT) {
+ struct io_ring_ctx *ctx = req->ctx;
+
+ spin_lock_irq(&ctx->timeout_lock);
+ io_for_each_link(cur, req)
+ io_prep_async_work(cur);
+ spin_unlock_irq(&ctx->timeout_lock);
+ } else {
+ io_for_each_link(cur, req)
+ io_prep_async_work(cur);
+ }
+}
+
+static void io_queue_async_work(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_kiocb *link = io_prep_linked_timeout(req);
+ struct io_uring_task *tctx = req->task->io_uring;
+
+ /* must not take the lock, NULL it as a precaution */
+ locked = NULL;
+
+ BUG_ON(!tctx);
+ BUG_ON(!tctx->io_wq);
+
+ /* init ->work of the whole link before punting */
+ io_prep_async_link(req);
+
+ /*
+ * Not expected to happen, but if we do have a bug where this _can_
+ * happen, catch it here and ensure the request is marked as
+ * canceled. That will make io-wq go through the usual work cancel
+ * procedure rather than attempt to run this request (or create a new
+ * worker for it).
+ */
+ if (WARN_ON_ONCE(!same_thread_group(req->task, current)))
+ req->work.flags |= IO_WQ_WORK_CANCEL;
+
+ trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
+ &req->work, req->flags);
+ io_wq_enqueue(tctx->io_wq, &req->work);
+ if (link)
+ io_queue_linked_timeout(link);
+}
+
+static void io_kill_timeout(struct io_kiocb *req, int status)
+ __must_hold(&req->ctx->completion_lock)
+ __must_hold(&req->ctx->timeout_lock)
+{
+ struct io_timeout_data *io = req->async_data;
+
+ if (hrtimer_try_to_cancel(&io->timer) != -1) {
+ if (status)
+ req_set_fail(req);
+ atomic_set(&req->ctx->cq_timeouts,
+ atomic_read(&req->ctx->cq_timeouts) + 1);
+ list_del_init(&req->timeout.list);
+ io_fill_cqe_req(req, status, 0);
+ io_put_req_deferred(req);
+ }
+}
+
+static void io_queue_deferred(struct io_ring_ctx *ctx)
+{
+ while (!list_empty(&ctx->defer_list)) {
+ struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
+ struct io_defer_entry, list);
+
+ if (req_need_defer(de->req, de->seq))
+ break;
+ list_del_init(&de->list);
+ io_req_task_queue(de->req);
+ kfree(de);
+ }
+}
+
+static void io_flush_timeouts(struct io_ring_ctx *ctx)
+ __must_hold(&ctx->completion_lock)
+{
+ u32 seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
+ struct io_kiocb *req, *tmp;
+
+ spin_lock_irq(&ctx->timeout_lock);
+ list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
+ u32 events_needed, events_got;
+
+ if (io_is_timeout_noseq(req))
+ break;
+
+ /*
+ * Since seq can easily wrap around over time, subtract
+ * the last seq at which timeouts were flushed before comparing.
+ * Assuming not more than 2^31-1 events have happened since,
+ * these subtractions won't have wrapped, so we can check if
+ * target is in [last_seq, current_seq] by comparing the two.
+ */
+ events_needed = req->timeout.target_seq - ctx->cq_last_tm_flush;
+ events_got = seq - ctx->cq_last_tm_flush;
+ if (events_got < events_needed)
+ break;
+
+ io_kill_timeout(req, 0);
+ }
+ ctx->cq_last_tm_flush = seq;
+ spin_unlock_irq(&ctx->timeout_lock);
+}
+
+static void __io_commit_cqring_flush(struct io_ring_ctx *ctx)
+{
+ if (ctx->off_timeout_used)
+ io_flush_timeouts(ctx);
+ if (ctx->drain_active)
+ io_queue_deferred(ctx);
+}
+
+static inline void io_commit_cqring(struct io_ring_ctx *ctx)
+{
+ if (unlikely(ctx->off_timeout_used || ctx->drain_active))
+ __io_commit_cqring_flush(ctx);
+ /* order cqe stores with ring update */
+ smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
+}
+
+static inline bool io_sqring_full(struct io_ring_ctx *ctx)
+{
+ struct io_rings *r = ctx->rings;
+
+ return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
+}
+
+static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
+{
+ return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
+}
+
+static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
+{
+ struct io_rings *rings = ctx->rings;
+ unsigned tail, mask = ctx->cq_entries - 1;
+
+ /*
+ * writes to the cq entry need to come after reading head; the
+ * control dependency is enough as we're using WRITE_ONCE to
+ * fill the cq entry
+ */
+ if (__io_cqring_events(ctx) == ctx->cq_entries)
+ return NULL;
+
+ tail = ctx->cached_cq_tail++;
+ return &rings->cqes[tail & mask];
+}
+
+static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
+{
+ if (likely(!ctx->cq_ev_fd))
+ return false;
+ if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
+ return false;
+ return !ctx->eventfd_async || io_wq_current_is_worker();
+}
+
+/*
+ * This should only get called when at least one event has been posted.
+ * Some applications rely on the eventfd notification count only changing
+ * IFF a new CQE has been added to the CQ ring. There's no depedency on
+ * 1:1 relationship between how many times this function is called (and
+ * hence the eventfd count) and number of CQEs posted to the CQ ring.
+ */
+static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
+{
+ /*
+ * wake_up_all() may seem excessive, but io_wake_function() and
+ * io_should_wake() handle the termination of the loop and only
+ * wake as many waiters as we need to.
+ */
+ if (wq_has_sleeper(&ctx->cq_wait))
+ wake_up_all(&ctx->cq_wait);
+ if (ctx->sq_data && waitqueue_active(&ctx->sq_data->wait))
+ wake_up(&ctx->sq_data->wait);
+ if (io_should_trigger_evfd(ctx))
+ eventfd_signal(ctx->cq_ev_fd, 1);
+ if (waitqueue_active(&ctx->poll_wait))
+ wake_up_interruptible(&ctx->poll_wait);
+}
+
+static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
+{
+ /* see waitqueue_active() comment */
+ smp_mb();
+
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
+ if (waitqueue_active(&ctx->cq_wait))
+ wake_up_all(&ctx->cq_wait);
+ }
+ if (io_should_trigger_evfd(ctx))
+ eventfd_signal(ctx->cq_ev_fd, 1);
+ if (waitqueue_active(&ctx->poll_wait))
+ wake_up_interruptible(&ctx->poll_wait);
+}
+
+/* Returns true if there are no backlogged entries after the flush */
+static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
+{
+ bool all_flushed, posted;
+
+ if (!force && __io_cqring_events(ctx) == ctx->cq_entries)
+ return false;
+
+ posted = false;
+ spin_lock(&ctx->completion_lock);
+ while (!list_empty(&ctx->cq_overflow_list)) {
+ struct io_uring_cqe *cqe = io_get_cqe(ctx);
+ struct io_overflow_cqe *ocqe;
+
+ if (!cqe && !force)
+ break;
+ ocqe = list_first_entry(&ctx->cq_overflow_list,
+ struct io_overflow_cqe, list);
+ if (cqe)
+ memcpy(cqe, &ocqe->cqe, sizeof(*cqe));
+ else
+ io_account_cq_overflow(ctx);
+
+ posted = true;
+ list_del(&ocqe->list);
+ kfree(ocqe);
+ }
+
+ all_flushed = list_empty(&ctx->cq_overflow_list);
+ if (all_flushed) {
+ clear_bit(0, &ctx->check_cq_overflow);
+ WRITE_ONCE(ctx->rings->sq_flags,
+ ctx->rings->sq_flags & ~IORING_SQ_CQ_OVERFLOW);
+ }
+
+ if (posted)
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ if (posted)
+ io_cqring_ev_posted(ctx);
+ return all_flushed;
+}
+
+static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx)
+{
+ bool ret = true;
+
+ if (test_bit(0, &ctx->check_cq_overflow)) {
+ /* iopoll syncs against uring_lock, not completion_lock */
+ if (ctx->flags & IORING_SETUP_IOPOLL)
+ mutex_lock(&ctx->uring_lock);
+ ret = __io_cqring_overflow_flush(ctx, false);
+ if (ctx->flags & IORING_SETUP_IOPOLL)
+ mutex_unlock(&ctx->uring_lock);
+ }
+
+ return ret;
+}
+
+/* must to be called somewhat shortly after putting a request */
+static inline void io_put_task(struct task_struct *task, int nr)
+{
+ struct io_uring_task *tctx = task->io_uring;
+
+ if (likely(task == current)) {
+ tctx->cached_refs += nr;
+ } else {
+ percpu_counter_sub(&tctx->inflight, nr);
+ if (unlikely(atomic_read(&tctx->in_idle)))
+ wake_up(&tctx->wait);
+ put_task_struct_many(task, nr);
+ }
+}
+
+static void io_task_refs_refill(struct io_uring_task *tctx)
+{
+ unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR;
+
+ percpu_counter_add(&tctx->inflight, refill);
+ refcount_add(refill, ¤t->usage);
+ tctx->cached_refs += refill;
+}
+
+static inline void io_get_task_refs(int nr)
+{
+ struct io_uring_task *tctx = current->io_uring;
+
+ tctx->cached_refs -= nr;
+ if (unlikely(tctx->cached_refs < 0))
+ io_task_refs_refill(tctx);
+}
+
+static __cold void io_uring_drop_tctx_refs(struct task_struct *task)
+{
+ struct io_uring_task *tctx = task->io_uring;
+ unsigned int refs = tctx->cached_refs;
+
+ if (refs) {
+ tctx->cached_refs = 0;
+ percpu_counter_sub(&tctx->inflight, refs);
+ put_task_struct_many(task, refs);
+ }
+}
+
+static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,
+ s32 res, u32 cflags)
+{
+ struct io_overflow_cqe *ocqe;
+
+ ocqe = kmalloc(sizeof(*ocqe), GFP_ATOMIC | __GFP_ACCOUNT);
+ if (!ocqe) {
+ /*
+ * If we're in ring overflow flush mode, or in task cancel mode,
+ * or cannot allocate an overflow entry, then we need to drop it
+ * on the floor.
+ */
+ io_account_cq_overflow(ctx);
+ return false;
+ }
+ if (list_empty(&ctx->cq_overflow_list)) {
+ set_bit(0, &ctx->check_cq_overflow);
+ WRITE_ONCE(ctx->rings->sq_flags,
+ ctx->rings->sq_flags | IORING_SQ_CQ_OVERFLOW);
+
+ }
+ ocqe->cqe.user_data = user_data;
+ ocqe->cqe.res = res;
+ ocqe->cqe.flags = cflags;
+ list_add_tail(&ocqe->list, &ctx->cq_overflow_list);
+ return true;
+}
+
+static inline bool __io_fill_cqe(struct io_ring_ctx *ctx, u64 user_data,
+ s32 res, u32 cflags)
+{
+ struct io_uring_cqe *cqe;
+
+ trace_io_uring_complete(ctx, user_data, res, cflags);
+
+ /*
+ * If we can't get a cq entry, userspace overflowed the
+ * submission (by quite a lot). Increment the overflow count in
+ * the ring.
+ */
+ cqe = io_get_cqe(ctx);
+ if (likely(cqe)) {
+ WRITE_ONCE(cqe->user_data, user_data);
+ WRITE_ONCE(cqe->res, res);
+ WRITE_ONCE(cqe->flags, cflags);
+ return true;
+ }
+ return io_cqring_event_overflow(ctx, user_data, res, cflags);
+}
+
+static noinline void io_fill_cqe_req(struct io_kiocb *req, s32 res, u32 cflags)
+{
+ __io_fill_cqe(req->ctx, req->user_data, res, cflags);
+}
+
+static noinline bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data,
+ s32 res, u32 cflags)
+{
+ ctx->cq_extra++;
+ return __io_fill_cqe(ctx, user_data, res, cflags);
+}
+
+static void io_req_complete_post(struct io_kiocb *req, s32 res,
+ u32 cflags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ spin_lock(&ctx->completion_lock);
+ __io_fill_cqe(ctx, req->user_data, res, cflags);
+ /*
+ * If we're the last reference to this request, add to our locked
+ * free_list cache.
+ */
+ if (req_ref_put_and_test(req)) {
+ if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
+ if (req->flags & IO_DISARM_MASK)
+ io_disarm_next(req);
+ if (req->link) {
+ io_req_task_queue(req->link);
+ req->link = NULL;
+ }
+ }
+ io_dismantle_req(req);
+ io_put_task(req->task, 1);
+ list_add(&req->inflight_entry, &ctx->locked_free_list);
+ ctx->locked_free_nr++;
+ } else {
+ if (!percpu_ref_tryget(&ctx->refs))
+ req = NULL;
+ }
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+
+ if (req) {
+ io_cqring_ev_posted(ctx);
+ percpu_ref_put(&ctx->refs);
+ }
+}
+
+static inline bool io_req_needs_clean(struct io_kiocb *req)
+{
+ return req->flags & IO_REQ_CLEAN_FLAGS;
+}
+
+static inline void io_req_complete_state(struct io_kiocb *req, s32 res,
+ u32 cflags)
+{
+ if (io_req_needs_clean(req))
+ io_clean_op(req);
+ req->result = res;
+ req->compl.cflags = cflags;
+ req->flags |= REQ_F_COMPLETE_INLINE;
+}
+
+static inline void __io_req_complete(struct io_kiocb *req, unsigned issue_flags,
+ s32 res, u32 cflags)
+{
+ if (issue_flags & IO_URING_F_COMPLETE_DEFER)
+ io_req_complete_state(req, res, cflags);
+ else
+ io_req_complete_post(req, res, cflags);
+}
+
+static inline void io_req_complete(struct io_kiocb *req, s32 res)
+{
+ __io_req_complete(req, 0, res, 0);
+}
+
+static void io_req_complete_failed(struct io_kiocb *req, s32 res)
+{
+ req_set_fail(req);
+ io_req_complete_post(req, res, 0);
+}
+
+static void io_req_complete_fail_submit(struct io_kiocb *req)
+{
+ /*
+ * We don't submit, fail them all, for that replace hardlinks with
+ * normal links. Extra REQ_F_LINK is tolerated.
+ */
+ req->flags &= ~REQ_F_HARDLINK;
+ req->flags |= REQ_F_LINK;
+ io_req_complete_failed(req, req->result);
+}
+
+/*
+ * Don't initialise the fields below on every allocation, but do that in
+ * advance and keep them valid across allocations.
+ */
+static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
+{
+ req->ctx = ctx;
+ req->link = NULL;
+ req->async_data = NULL;
+ /* not necessary, but safer to zero */
+ req->result = 0;
+}
+
+static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,
+ struct io_submit_state *state)
+{
+ spin_lock(&ctx->completion_lock);
+ list_splice_init(&ctx->locked_free_list, &state->free_list);
+ ctx->locked_free_nr = 0;
+ spin_unlock(&ctx->completion_lock);
+}
+
+/* Returns true IFF there are requests in the cache */
+static bool io_flush_cached_reqs(struct io_ring_ctx *ctx)
+{
+ struct io_submit_state *state = &ctx->submit_state;
+ int nr;
+
+ /*
+ * If we have more than a batch's worth of requests in our IRQ side
+ * locked cache, grab the lock and move them over to our submission
+ * side cache.
+ */
+ if (READ_ONCE(ctx->locked_free_nr) > IO_COMPL_BATCH)
+ io_flush_cached_locked_reqs(ctx, state);
+
+ nr = state->free_reqs;
+ while (!list_empty(&state->free_list)) {
+ struct io_kiocb *req = list_first_entry(&state->free_list,
+ struct io_kiocb, inflight_entry);
+
+ list_del(&req->inflight_entry);
+ state->reqs[nr++] = req;
+ if (nr == ARRAY_SIZE(state->reqs))
+ break;
+ }
+
+ state->free_reqs = nr;
+ return nr != 0;
+}
+
+/*
+ * A request might get retired back into the request caches even before opcode
+ * handlers and io_issue_sqe() are done with it, e.g. inline completion path.
+ * Because of that, io_alloc_req() should be called only under ->uring_lock
+ * and with extra caution to not get a request that is still worked on.
+ */
+static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_submit_state *state = &ctx->submit_state;
+ gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
+ int ret, i;
+
+ BUILD_BUG_ON(ARRAY_SIZE(state->reqs) < IO_REQ_ALLOC_BATCH);
+
+ if (likely(state->free_reqs || io_flush_cached_reqs(ctx)))
+ goto got_req;
+
+ ret = kmem_cache_alloc_bulk(req_cachep, gfp, IO_REQ_ALLOC_BATCH,
+ state->reqs);
+
+ /*
+ * Bulk alloc is all-or-nothing. If we fail to get a batch,
+ * retry single alloc to be on the safe side.
+ */
+ if (unlikely(ret <= 0)) {
+ state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
+ if (!state->reqs[0])
+ return NULL;
+ ret = 1;
+ }
+
+ for (i = 0; i < ret; i++)
+ io_preinit_req(state->reqs[i], ctx);
+ state->free_reqs = ret;
+got_req:
+ state->free_reqs--;
+ return state->reqs[state->free_reqs];
+}
+
+static inline void io_put_file(struct file *file)
+{
+ if (file)
+ fput(file);
+}
+
+static void io_dismantle_req(struct io_kiocb *req)
+{
+ unsigned int flags = req->flags;
+
+ if (io_req_needs_clean(req))
+ io_clean_op(req);
+ if (!(flags & REQ_F_FIXED_FILE))
+ io_put_file(req->file);
+ if (req->fixed_rsrc_refs)
+ percpu_ref_put(req->fixed_rsrc_refs);
+ if (req->async_data) {
+ kfree(req->async_data);
+ req->async_data = NULL;
+ }
+}
+
+static void __io_free_req(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ io_dismantle_req(req);
+ io_put_task(req->task, 1);
+
+ spin_lock(&ctx->completion_lock);
+ list_add(&req->inflight_entry, &ctx->locked_free_list);
+ ctx->locked_free_nr++;
+ spin_unlock(&ctx->completion_lock);
+
+ percpu_ref_put(&ctx->refs);
+}
+
+static inline void io_remove_next_linked(struct io_kiocb *req)
+{
+ struct io_kiocb *nxt = req->link;
+
+ req->link = nxt->link;
+ nxt->link = NULL;
+}
+
+static bool io_kill_linked_timeout(struct io_kiocb *req)
+ __must_hold(&req->ctx->completion_lock)
+ __must_hold(&req->ctx->timeout_lock)
+{
+ struct io_kiocb *link = req->link;
+
+ if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {
+ struct io_timeout_data *io = link->async_data;
+
+ io_remove_next_linked(req);
+ link->timeout.head = NULL;
+ if (hrtimer_try_to_cancel(&io->timer) != -1) {
+ list_del(&link->timeout.list);
+ io_fill_cqe_req(link, -ECANCELED, 0);
+ io_put_req_deferred(link);
+ return true;
+ }
+ }
+ return false;
+}
+
+static void io_fail_links(struct io_kiocb *req)
+ __must_hold(&req->ctx->completion_lock)
+{
+ struct io_kiocb *nxt, *link = req->link;
+
+ req->link = NULL;
+ while (link) {
+ long res = -ECANCELED;
+
+ if (link->flags & REQ_F_FAIL)
+ res = link->result;
+
+ nxt = link->link;
+ link->link = NULL;
+
+ trace_io_uring_fail_link(req, link);
+ io_fill_cqe_req(link, res, 0);
+ io_put_req_deferred(link);
+ link = nxt;
+ }
+}
+
+static bool io_disarm_next(struct io_kiocb *req)
+ __must_hold(&req->ctx->completion_lock)
+{
+ bool posted = false;
+
+ if (req->flags & REQ_F_ARM_LTIMEOUT) {
+ struct io_kiocb *link = req->link;
+
+ req->flags &= ~REQ_F_ARM_LTIMEOUT;
+ if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {
+ io_remove_next_linked(req);
+ io_fill_cqe_req(link, -ECANCELED, 0);
+ io_put_req_deferred(link);
+ posted = true;
+ }
+ } else if (req->flags & REQ_F_LINK_TIMEOUT) {
+ struct io_ring_ctx *ctx = req->ctx;
+
+ spin_lock_irq(&ctx->timeout_lock);
+ posted = io_kill_linked_timeout(req);
+ spin_unlock_irq(&ctx->timeout_lock);
+ }
+ if (unlikely((req->flags & REQ_F_FAIL) &&
+ !(req->flags & REQ_F_HARDLINK))) {
+ posted |= (req->link != NULL);
+ io_fail_links(req);
+ }
+ return posted;
+}
+
+static struct io_kiocb *__io_req_find_next(struct io_kiocb *req)
+{
+ struct io_kiocb *nxt;
+
+ /*
+ * If LINK is set, we have dependent requests in this chain. If we
+ * didn't fail this request, queue the first one up, moving any other
+ * dependencies to the next request. In case of failure, fail the rest
+ * of the chain.
+ */
+ if (req->flags & IO_DISARM_MASK) {
+ struct io_ring_ctx *ctx = req->ctx;
+ bool posted;
+
+ spin_lock(&ctx->completion_lock);
+ posted = io_disarm_next(req);
+ if (posted)
+ io_commit_cqring(req->ctx);
+ spin_unlock(&ctx->completion_lock);
+ if (posted)
+ io_cqring_ev_posted(ctx);
+ }
+ nxt = req->link;
+ req->link = NULL;
+ return nxt;
+}
+
+static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
+{
+ if (likely(!(req->flags & (REQ_F_LINK|REQ_F_HARDLINK))))
+ return NULL;
+ return __io_req_find_next(req);
+}
+
+static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked)
+{
+ if (!ctx)
+ return;
+ if (*locked) {
+ if (ctx->submit_state.compl_nr)
+ io_submit_flush_completions(ctx);
+ mutex_unlock(&ctx->uring_lock);
+ *locked = false;
+ }
+ percpu_ref_put(&ctx->refs);
+}
+
+static void tctx_task_work(struct callback_head *cb)
+{
+ bool locked = false;
+ struct io_ring_ctx *ctx = NULL;
+ struct io_uring_task *tctx = container_of(cb, struct io_uring_task,
+ task_work);
+
+ while (1) {
+ struct io_wq_work_node *node;
+
+ if (!tctx->task_list.first && locked && ctx->submit_state.compl_nr)
+ io_submit_flush_completions(ctx);
+
+ spin_lock_irq(&tctx->task_lock);
+ node = tctx->task_list.first;
+ INIT_WQ_LIST(&tctx->task_list);
+ if (!node)
+ tctx->task_running = false;
+ spin_unlock_irq(&tctx->task_lock);
+ if (!node)
+ break;
+
+ do {
+ struct io_wq_work_node *next = node->next;
+ struct io_kiocb *req = container_of(node, struct io_kiocb,
+ io_task_work.node);
+
+ if (req->ctx != ctx) {
+ ctx_flush_and_put(ctx, &locked);
+ ctx = req->ctx;
+ /* if not contended, grab and improve batching */
+ locked = mutex_trylock(&ctx->uring_lock);
+ percpu_ref_get(&ctx->refs);
+ }
+ req->io_task_work.func(req, &locked);
+ node = next;
+ } while (node);
+
+ cond_resched();
+ }
+
+ ctx_flush_and_put(ctx, &locked);
+
+ /* relaxed read is enough as only the task itself sets ->in_idle */
+ if (unlikely(atomic_read(&tctx->in_idle)))
+ io_uring_drop_tctx_refs(current);
+}
+
+static void io_req_task_work_add(struct io_kiocb *req)
+{
+ struct task_struct *tsk = req->task;
+ struct io_uring_task *tctx = tsk->io_uring;
+ enum task_work_notify_mode notify;
+ struct io_wq_work_node *node;
+ unsigned long flags;
+ bool running;
+
+ WARN_ON_ONCE(!tctx);
+
+ spin_lock_irqsave(&tctx->task_lock, flags);
+ wq_list_add_tail(&req->io_task_work.node, &tctx->task_list);
+ running = tctx->task_running;
+ if (!running)
+ tctx->task_running = true;
+ spin_unlock_irqrestore(&tctx->task_lock, flags);
+
+ /* task_work already pending, we're done */
+ if (running)
+ return;
+
+ /*
+ * SQPOLL kernel thread doesn't need notification, just a wakeup. For
+ * all other cases, use TWA_SIGNAL unconditionally to ensure we're
+ * processing task_work. There's no reliable way to tell if TWA_RESUME
+ * will do the job.
+ */
+ notify = (req->ctx->flags & IORING_SETUP_SQPOLL) ? TWA_NONE : TWA_SIGNAL;
+ if (!task_work_add(tsk, &tctx->task_work, notify)) {
+ wake_up_process(tsk);
+ return;
+ }
+
+ spin_lock_irqsave(&tctx->task_lock, flags);
+ tctx->task_running = false;
+ node = tctx->task_list.first;
+ INIT_WQ_LIST(&tctx->task_list);
+ spin_unlock_irqrestore(&tctx->task_lock, flags);
+
+ while (node) {
+ req = container_of(node, struct io_kiocb, io_task_work.node);
+ node = node->next;
+ if (llist_add(&req->io_task_work.fallback_node,
+ &req->ctx->fallback_llist))
+ schedule_delayed_work(&req->ctx->fallback_work, 1);
+ }
+}
+
+static void io_req_task_cancel(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ /* not needed for normal modes, but SQPOLL depends on it */
+ io_tw_lock(ctx, locked);
+ io_req_complete_failed(req, req->result);
+}
+
+static void io_req_task_submit(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ io_tw_lock(ctx, locked);
+ /* req->task == current here, checking PF_EXITING is safe */
+ if (likely(!(req->task->flags & PF_EXITING)))
+ __io_queue_sqe(req);
+ else
+ io_req_complete_failed(req, -EFAULT);
+}
+
+static void io_req_task_queue_fail(struct io_kiocb *req, int ret)
+{
+ req->result = ret;
+ req->io_task_work.func = io_req_task_cancel;
+ io_req_task_work_add(req);
+}
+
+static void io_req_task_queue(struct io_kiocb *req)
+{
+ req->io_task_work.func = io_req_task_submit;
+ io_req_task_work_add(req);
+}
+
+static void io_req_task_queue_reissue(struct io_kiocb *req)
+{
+ req->io_task_work.func = io_queue_async_work;
+ io_req_task_work_add(req);
+}
+
+static inline void io_queue_next(struct io_kiocb *req)
+{
+ struct io_kiocb *nxt = io_req_find_next(req);
+
+ if (nxt)
+ io_req_task_queue(nxt);
+}
+
+static void io_free_req(struct io_kiocb *req)
+{
+ io_queue_next(req);
+ __io_free_req(req);
+}
+
+static void io_free_req_work(struct io_kiocb *req, bool *locked)
+{
+ io_free_req(req);
+}
+
+struct req_batch {
+ struct task_struct *task;
+ int task_refs;
+ int ctx_refs;
+};
+
+static inline void io_init_req_batch(struct req_batch *rb)
+{
+ rb->task_refs = 0;
+ rb->ctx_refs = 0;
+ rb->task = NULL;
+}
+
+static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
+ struct req_batch *rb)
+{
+ if (rb->ctx_refs)
+ percpu_ref_put_many(&ctx->refs, rb->ctx_refs);
+ if (rb->task)
+ io_put_task(rb->task, rb->task_refs);
+}
+
+static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req,
+ struct io_submit_state *state)
+{
+ io_queue_next(req);
+ io_dismantle_req(req);
+
+ if (req->task != rb->task) {
+ if (rb->task)
+ io_put_task(rb->task, rb->task_refs);
+ rb->task = req->task;
+ rb->task_refs = 0;
+ }
+ rb->task_refs++;
+ rb->ctx_refs++;
+
+ if (state->free_reqs != ARRAY_SIZE(state->reqs))
+ state->reqs[state->free_reqs++] = req;
+ else
+ list_add(&req->inflight_entry, &state->free_list);
+}
+
+static void io_submit_flush_completions(struct io_ring_ctx *ctx)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_submit_state *state = &ctx->submit_state;
+ int i, nr = state->compl_nr;
+ struct req_batch rb;
+
+ spin_lock(&ctx->completion_lock);
+ for (i = 0; i < nr; i++) {
+ struct io_kiocb *req = state->compl_reqs[i];
+
+ __io_fill_cqe(ctx, req->user_data, req->result,
+ req->compl.cflags);
+ }
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ io_cqring_ev_posted(ctx);
+
+ io_init_req_batch(&rb);
+ for (i = 0; i < nr; i++) {
+ struct io_kiocb *req = state->compl_reqs[i];
+
+ if (req_ref_put_and_test(req))
+ io_req_free_batch(&rb, req, &ctx->submit_state);
+ }
+
+ io_req_free_batch_finish(ctx, &rb);
+ state->compl_nr = 0;
+}
+
+/*
+ * Drop reference to request, return next in chain (if there is one) if this
+ * was the last reference to this request.
+ */
+static inline struct io_kiocb *io_put_req_find_next(struct io_kiocb *req)
+{
+ struct io_kiocb *nxt = NULL;
+
+ if (req_ref_put_and_test(req)) {
+ nxt = io_req_find_next(req);
+ __io_free_req(req);
+ }
+ return nxt;
+}
+
+static inline void io_put_req(struct io_kiocb *req)
+{
+ if (req_ref_put_and_test(req))
+ io_free_req(req);
+}
+
+static inline void io_put_req_deferred(struct io_kiocb *req)
+{
+ if (req_ref_put_and_test(req)) {
+ req->io_task_work.func = io_free_req_work;
+ io_req_task_work_add(req);
+ }
+}
+
+static unsigned io_cqring_events(struct io_ring_ctx *ctx)
+{
+ /* See comment at the top of this file */
+ smp_rmb();
+ return __io_cqring_events(ctx);
+}
+
+static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
+{
+ struct io_rings *rings = ctx->rings;
+
+ /* make sure SQ entry isn't read before tail */
+ return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
+}
+
+static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf)
+{
+ unsigned int cflags;
+
+ cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
+ cflags |= IORING_CQE_F_BUFFER;
+ req->flags &= ~REQ_F_BUFFER_SELECTED;
+ kfree(kbuf);
+ return cflags;
+}
+
+static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
+{
+ struct io_buffer *kbuf;
+
+ if (likely(!(req->flags & REQ_F_BUFFER_SELECTED)))
+ return 0;
+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
+ return io_put_kbuf(req, kbuf);
+}
+
+static inline bool io_run_task_work(void)
+{
+ if (test_thread_flag(TIF_NOTIFY_SIGNAL) || current->task_works) {
+ __set_current_state(TASK_RUNNING);
+ tracehook_notify_signal();
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * Find and free completed poll iocbs
+ */
+static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
+ struct list_head *done)
+{
+ struct req_batch rb;
+ struct io_kiocb *req;
+
+ /* order with ->result store in io_complete_rw_iopoll() */
+ smp_rmb();
+
+ io_init_req_batch(&rb);
+ while (!list_empty(done)) {
+ req = list_first_entry(done, struct io_kiocb, inflight_entry);
+ list_del(&req->inflight_entry);
+
+ io_fill_cqe_req(req, req->result, io_put_rw_kbuf(req));
+ (*nr_events)++;
+
+ if (req_ref_put_and_test(req))
+ io_req_free_batch(&rb, req, &ctx->submit_state);
+ }
+
+ io_commit_cqring(ctx);
+ io_cqring_ev_posted_iopoll(ctx);
+ io_req_free_batch_finish(ctx, &rb);
+}
+
+static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
+ long min)
+{
+ struct io_kiocb *req, *tmp;
+ LIST_HEAD(done);
+ bool spin;
+
+ /*
+ * Only spin for completions if we don't have multiple devices hanging
+ * off our complete list, and we're under the requested amount.
+ */
+ spin = !ctx->poll_multi_queue && *nr_events < min;
+
+ list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) {
+ struct kiocb *kiocb = &req->rw.kiocb;
+ int ret;
+
+ /*
+ * Move completed and retryable entries to our local lists.
+ * If we find a request that requires polling, break out
+ * and complete those lists first, if we have entries there.
+ */
+ if (READ_ONCE(req->iopoll_completed)) {
+ list_move_tail(&req->inflight_entry, &done);
+ continue;
+ }
+ if (!list_empty(&done))
+ break;
+
+ ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
+ if (unlikely(ret < 0))
+ return ret;
+ else if (ret)
+ spin = false;
+
+ /* iopoll may have completed current req */
+ if (READ_ONCE(req->iopoll_completed))
+ list_move_tail(&req->inflight_entry, &done);
+ }
+
+ if (!list_empty(&done))
+ io_iopoll_complete(ctx, nr_events, &done);
+
+ return 0;
+}
+
+/*
+ * We can't just wait for polled events to come to us, we have to actively
+ * find and complete them.
+ */
+static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
+{
+ if (!(ctx->flags & IORING_SETUP_IOPOLL))
+ return;
+
+ mutex_lock(&ctx->uring_lock);
+ while (!list_empty(&ctx->iopoll_list)) {
+ unsigned int nr_events = 0;
+
+ io_do_iopoll(ctx, &nr_events, 0);
+
+ /* let it sleep and repeat later if can't complete a request */
+ if (nr_events == 0)
+ break;
+ /*
+ * Ensure we allow local-to-the-cpu processing to take place,
+ * in this case we need to ensure that we reap all events.
+ * Also let task_work, etc. to progress by releasing the mutex
+ */
+ if (need_resched()) {
+ mutex_unlock(&ctx->uring_lock);
+ cond_resched();
+ mutex_lock(&ctx->uring_lock);
+ }
+ }
+ mutex_unlock(&ctx->uring_lock);
+}
+
+static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
+{
+ unsigned int nr_events = 0;
+ int ret = 0;
+
+ /*
+ * We disallow the app entering submit/complete with polling, but we
+ * still need to lock the ring to prevent racing with polled issue
+ * that got punted to a workqueue.
+ */
+ mutex_lock(&ctx->uring_lock);
+ /*
+ * Don't enter poll loop if we already have events pending.
+ * If we do, we can potentially be spinning for commands that
+ * already triggered a CQE (eg in error).
+ */
+ if (test_bit(0, &ctx->check_cq_overflow))
+ __io_cqring_overflow_flush(ctx, false);
+ if (io_cqring_events(ctx))
+ goto out;
+ do {
+ /*
+ * If a submit got punted to a workqueue, we can have the
+ * application entering polling for a command before it gets
+ * issued. That app will hold the uring_lock for the duration
+ * of the poll right here, so we need to take a breather every
+ * now and then to ensure that the issue has a chance to add
+ * the poll to the issued list. Otherwise we can spin here
+ * forever, while the workqueue is stuck trying to acquire the
+ * very same mutex.
+ */
+ if (list_empty(&ctx->iopoll_list)) {
+ u32 tail = ctx->cached_cq_tail;
+
+ mutex_unlock(&ctx->uring_lock);
+ io_run_task_work();
+ mutex_lock(&ctx->uring_lock);
+
+ /* some requests don't go through iopoll_list */
+ if (tail != ctx->cached_cq_tail ||
+ list_empty(&ctx->iopoll_list))
+ break;
+ }
+ ret = io_do_iopoll(ctx, &nr_events, min);
+ } while (!ret && nr_events < min && !need_resched());
+out:
+ mutex_unlock(&ctx->uring_lock);
+ return ret;
+}
+
+static void kiocb_end_write(struct io_kiocb *req)
+{
+ /*
+ * Tell lockdep we inherited freeze protection from submission
+ * thread.
+ */
+ if (req->flags & REQ_F_ISREG) {
+ struct super_block *sb = file_inode(req->file)->i_sb;
+
+ __sb_writers_acquired(sb, SB_FREEZE_WRITE);
+ sb_end_write(sb);
+ }
+}
+
+#ifdef CONFIG_BLOCK
+static bool io_resubmit_prep(struct io_kiocb *req)
+{
+ struct io_async_rw *rw = req->async_data;
+
+ if (!rw)
+ return !io_req_prep_async(req);
+ iov_iter_restore(&rw->iter, &rw->iter_state);
+ return true;
+}
+
+static bool io_rw_should_reissue(struct io_kiocb *req)
+{
+ umode_t mode = file_inode(req->file)->i_mode;
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (!S_ISBLK(mode) && !S_ISREG(mode))
+ return false;
+ if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() &&
+ !(ctx->flags & IORING_SETUP_IOPOLL)))
+ return false;
+ /*
+ * If ref is dying, we might be running poll reap from the exit work.
+ * Don't attempt to reissue from that path, just let it fail with
+ * -EAGAIN.
+ */
+ if (percpu_ref_is_dying(&ctx->refs))
+ return false;
+ /*
+ * Play it safe and assume not safe to re-import and reissue if we're
+ * not in the original thread group (or in task context).
+ */
+ if (!same_thread_group(req->task, current) || !in_task())
+ return false;
+ return true;
+}
+#else
+static bool io_resubmit_prep(struct io_kiocb *req)
+{
+ return false;
+}
+static bool io_rw_should_reissue(struct io_kiocb *req)
+{
+ return false;
+}
+#endif
+
+static bool __io_complete_rw_common(struct io_kiocb *req, long res)
+{
+ if (req->rw.kiocb.ki_flags & IOCB_WRITE) {
+ kiocb_end_write(req);
+ fsnotify_modify(req->file);
+ } else {
+ fsnotify_access(req->file);
+ }
+ if (res != req->result) {
+ if ((res == -EAGAIN || res == -EOPNOTSUPP) &&
+ io_rw_should_reissue(req)) {
+ req->flags |= REQ_F_REISSUE;
+ return true;
+ }
+ req_set_fail(req);
+ req->result = res;
+ }
+ return false;
+}
+
+static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res)
+{
+ struct io_async_rw *io = req->async_data;
+
+ /* add previously done IO, if any */
+ if (io && io->bytes_done > 0) {
+ if (res < 0)
+ res = io->bytes_done;
+ else
+ res += io->bytes_done;
+ }
+ return res;
+}
+
+static void io_req_task_complete(struct io_kiocb *req, bool *locked)
+{
+ unsigned int cflags = io_put_rw_kbuf(req);
+ int res = req->result;
+
+ if (*locked) {
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_submit_state *state = &ctx->submit_state;
+
+ io_req_complete_state(req, res, cflags);
+ state->compl_reqs[state->compl_nr++] = req;
+ if (state->compl_nr == ARRAY_SIZE(state->compl_reqs))
+ io_submit_flush_completions(ctx);
+ } else {
+ io_req_complete_post(req, res, cflags);
+ }
+}
+
+static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
+ unsigned int issue_flags)
+{
+ if (__io_complete_rw_common(req, res))
+ return;
+ __io_req_complete(req, issue_flags, io_fixup_rw_res(req, res), io_put_rw_kbuf(req));
+}
+
+static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
+{
+ struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
+
+ if (__io_complete_rw_common(req, res))
+ return;
+ req->result = io_fixup_rw_res(req, res);
+ req->io_task_work.func = io_req_task_complete;
+ io_req_task_work_add(req);
+}
+
+static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
+{
+ struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
+
+ if (kiocb->ki_flags & IOCB_WRITE)
+ kiocb_end_write(req);
+ if (unlikely(res != req->result)) {
+ if (res == -EAGAIN && io_rw_should_reissue(req)) {
+ req->flags |= REQ_F_REISSUE;
+ return;
+ }
+ }
+
+ WRITE_ONCE(req->result, res);
+ /* order with io_iopoll_complete() checking ->result */
+ smp_wmb();
+ WRITE_ONCE(req->iopoll_completed, 1);
+}
+
+/*
+ * After the iocb has been issued, it's safe to be found on the poll list.
+ * Adding the kiocb to the list AFTER submission ensures that we don't
+ * find it from a io_do_iopoll() thread before the issuer is done
+ * accessing the kiocb cookie.
+ */
+static void io_iopoll_req_issued(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ const bool in_async = io_wq_current_is_worker();
+
+ /* workqueue context doesn't hold uring_lock, grab it now */
+ if (unlikely(in_async))
+ mutex_lock(&ctx->uring_lock);
+
+ /*
+ * Track whether we have multiple files in our lists. This will impact
+ * how we do polling eventually, not spinning if we're on potentially
+ * different devices.
+ */
+ if (list_empty(&ctx->iopoll_list)) {
+ ctx->poll_multi_queue = false;
+ } else if (!ctx->poll_multi_queue) {
+ struct io_kiocb *list_req;
+ unsigned int queue_num0, queue_num1;
+
+ list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb,
+ inflight_entry);
+
+ if (list_req->file != req->file) {
+ ctx->poll_multi_queue = true;
+ } else {
+ queue_num0 = blk_qc_t_to_queue_num(list_req->rw.kiocb.ki_cookie);
+ queue_num1 = blk_qc_t_to_queue_num(req->rw.kiocb.ki_cookie);
+ if (queue_num0 != queue_num1)
+ ctx->poll_multi_queue = true;
+ }
+ }
+
+ /*
+ * For fast devices, IO may have already completed. If it has, add
+ * it to the front so we find it first.
+ */
+ if (READ_ONCE(req->iopoll_completed))
+ list_add(&req->inflight_entry, &ctx->iopoll_list);
+ else
+ list_add_tail(&req->inflight_entry, &ctx->iopoll_list);
+
+ if (unlikely(in_async)) {
+ /*
+ * If IORING_SETUP_SQPOLL is enabled, sqes are either handle
+ * in sq thread task context or in io worker task context. If
+ * current task context is sq thread, we don't need to check
+ * whether should wake up sq thread.
+ */
+ if ((ctx->flags & IORING_SETUP_SQPOLL) &&
+ wq_has_sleeper(&ctx->sq_data->wait))
+ wake_up(&ctx->sq_data->wait);
+
+ mutex_unlock(&ctx->uring_lock);
+ }
+}
+
+static bool io_bdev_nowait(struct block_device *bdev)
+{
+ return !bdev || blk_queue_nowait(bdev_get_queue(bdev));
+}
+
+/*
+ * If we tracked the file through the SCM inflight mechanism, we could support
+ * any file. For now, just ensure that anything potentially problematic is done
+ * inline.
+ */
+static bool __io_file_supports_nowait(struct file *file, int rw)
+{
+ umode_t mode = file_inode(file)->i_mode;
+
+ if (S_ISBLK(mode)) {
+ if (IS_ENABLED(CONFIG_BLOCK) &&
+ io_bdev_nowait(I_BDEV(file->f_mapping->host)))
+ return true;
+ return false;
+ }
+ if (S_ISSOCK(mode))
+ return true;
+ if (S_ISREG(mode)) {
+ if (IS_ENABLED(CONFIG_BLOCK) &&
+ io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
+ file->f_op != &io_uring_fops)
+ return true;
+ return false;
+ }
+
+ /* any ->read/write should understand O_NONBLOCK */
+ if (file->f_flags & O_NONBLOCK)
+ return true;
+
+ if (!(file->f_mode & FMODE_NOWAIT))
+ return false;
+
+ if (rw == READ)
+ return file->f_op->read_iter != NULL;
+
+ return file->f_op->write_iter != NULL;
+}
+
+static bool io_file_supports_nowait(struct io_kiocb *req, int rw)
+{
+ if (rw == READ && (req->flags & REQ_F_NOWAIT_READ))
+ return true;
+ else if (rw == WRITE && (req->flags & REQ_F_NOWAIT_WRITE))
+ return true;
+
+ return __io_file_supports_nowait(req->file, rw);
+}
+
+static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
+ int rw)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct kiocb *kiocb = &req->rw.kiocb;
+ struct file *file = req->file;
+ unsigned ioprio;
+ int ret;
+
+ if (!io_req_ffs_set(req) && S_ISREG(file_inode(file)->i_mode))
+ req->flags |= REQ_F_ISREG;
+
+ kiocb->ki_pos = READ_ONCE(sqe->off);
+ if (kiocb->ki_pos == -1) {
+ if (!(file->f_mode & FMODE_STREAM)) {
+ req->flags |= REQ_F_CUR_POS;
+ kiocb->ki_pos = file->f_pos;
+ } else {
+ kiocb->ki_pos = 0;
+ }
+ }
+ kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
+ kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
+ ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
+ if (unlikely(ret))
+ return ret;
+
+ /*
+ * If the file is marked O_NONBLOCK, still allow retry for it if it
+ * supports async. Otherwise it's impossible to use O_NONBLOCK files
+ * reliably. If not, or it IOCB_NOWAIT is set, don't retry.
+ */
+ if ((kiocb->ki_flags & IOCB_NOWAIT) ||
+ ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req, rw)))
+ req->flags |= REQ_F_NOWAIT;
+
+ ioprio = READ_ONCE(sqe->ioprio);
+ if (ioprio) {
+ ret = ioprio_check_cap(ioprio);
+ if (ret)
+ return ret;
+
+ kiocb->ki_ioprio = ioprio;
+ } else
+ kiocb->ki_ioprio = get_current_ioprio();
+
+ if (ctx->flags & IORING_SETUP_IOPOLL) {
+ if (!(kiocb->ki_flags & IOCB_DIRECT) ||
+ !kiocb->ki_filp->f_op->iopoll)
+ return -EOPNOTSUPP;
+
+ kiocb->ki_flags |= IOCB_HIPRI;
+ kiocb->ki_complete = io_complete_rw_iopoll;
+ req->iopoll_completed = 0;
+ } else {
+ if (kiocb->ki_flags & IOCB_HIPRI)
+ return -EINVAL;
+ kiocb->ki_complete = io_complete_rw;
+ }
+
+ /* used for fixed read/write too - just read unconditionally */
+ req->buf_index = READ_ONCE(sqe->buf_index);
+ req->imu = NULL;
+
+ if (req->opcode == IORING_OP_READ_FIXED ||
+ req->opcode == IORING_OP_WRITE_FIXED) {
+ struct io_ring_ctx *ctx = req->ctx;
+ u16 index;
+
+ if (unlikely(req->buf_index >= ctx->nr_user_bufs))
+ return -EFAULT;
+ index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
+ req->imu = ctx->user_bufs[index];
+ io_req_set_rsrc_node(req);
+ }
+
+ req->rw.addr = READ_ONCE(sqe->addr);
+ req->rw.len = READ_ONCE(sqe->len);
+ return 0;
+}
+
+static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
+{
+ switch (ret) {
+ case -EIOCBQUEUED:
+ break;
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ case -ERESTARTNOHAND:
+ case -ERESTART_RESTARTBLOCK:
+ /*
+ * We can't just restart the syscall, since previously
+ * submitted sqes may already be in progress. Just fail this
+ * IO with EINTR.
+ */
+ ret = -EINTR;
+ fallthrough;
+ default:
+ kiocb->ki_complete(kiocb, ret, 0);
+ }
+}
+
+static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
+ unsigned int issue_flags)
+{
+ struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
+
+ if (req->flags & REQ_F_CUR_POS)
+ req->file->f_pos = kiocb->ki_pos;
+ if (ret >= 0 && (kiocb->ki_complete == io_complete_rw))
+ __io_complete_rw(req, ret, 0, issue_flags);
+ else
+ io_rw_done(kiocb, ret);
+
+ if (req->flags & REQ_F_REISSUE) {
+ req->flags &= ~REQ_F_REISSUE;
+ if (io_resubmit_prep(req)) {
+ io_req_task_queue_reissue(req);
+ } else {
+ unsigned int cflags = io_put_rw_kbuf(req);
+ struct io_ring_ctx *ctx = req->ctx;
+
+ ret = io_fixup_rw_res(req, ret);
+ req_set_fail(req);
+ if (!(issue_flags & IO_URING_F_NONBLOCK)) {
+ mutex_lock(&ctx->uring_lock);
+ __io_req_complete(req, issue_flags, ret, cflags);
+ mutex_unlock(&ctx->uring_lock);
+ } else {
+ __io_req_complete(req, issue_flags, ret, cflags);
+ }
+ }
+ }
+}
+
+static int __io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter,
+ struct io_mapped_ubuf *imu)
+{
+ size_t len = req->rw.len;
+ u64 buf_end, buf_addr = req->rw.addr;
+ size_t offset;
+
+ if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end)))
+ return -EFAULT;
+ /* not inside the mapped region */
+ if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end))
+ return -EFAULT;
+
+ /*
+ * May not be a start of buffer, set size appropriately
+ * and advance us to the beginning.
+ */
+ offset = buf_addr - imu->ubuf;
+ iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
+
+ if (offset) {
+ /*
+ * Don't use iov_iter_advance() here, as it's really slow for
+ * using the latter parts of a big fixed buffer - it iterates
+ * over each segment manually. We can cheat a bit here, because
+ * we know that:
+ *
+ * 1) it's a BVEC iter, we set it up
+ * 2) all bvecs are PAGE_SIZE in size, except potentially the
+ * first and last bvec
+ *
+ * So just find our index, and adjust the iterator afterwards.
+ * If the offset is within the first bvec (or the whole first
+ * bvec, just use iov_iter_advance(). This makes it easier
+ * since we can just skip the first segment, which may not
+ * be PAGE_SIZE aligned.
+ */
+ const struct bio_vec *bvec = imu->bvec;
+
+ if (offset <= bvec->bv_len) {
+ iov_iter_advance(iter, offset);
+ } else {
+ unsigned long seg_skip;
+
+ /* skip first vec */
+ offset -= bvec->bv_len;
+ seg_skip = 1 + (offset >> PAGE_SHIFT);
+
+ iter->bvec = bvec + seg_skip;
+ iter->nr_segs -= seg_skip;
+ iter->count -= bvec->bv_len + offset;
+ iter->iov_offset = offset & ~PAGE_MASK;
+ }
+ }
+
+ return 0;
+}
+
+static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter)
+{
+ if (WARN_ON_ONCE(!req->imu))
+ return -EFAULT;
+ return __io_import_fixed(req, rw, iter, req->imu);
+}
+
+static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
+{
+ if (needs_lock)
+ mutex_unlock(&ctx->uring_lock);
+}
+
+static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
+{
+ /*
+ * "Normal" inline submissions always hold the uring_lock, since we
+ * grab it from the system call. Same is true for the SQPOLL offload.
+ * The only exception is when we've detached the request and issue it
+ * from an async worker thread, grab the lock for that case.
+ */
+ if (needs_lock)
+ mutex_lock(&ctx->uring_lock);
+}
+
+static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
+ int bgid, struct io_buffer *kbuf,
+ bool needs_lock)
+{
+ struct io_buffer *head;
+
+ if (req->flags & REQ_F_BUFFER_SELECTED)
+ return kbuf;
+
+ io_ring_submit_lock(req->ctx, needs_lock);
+
+ lockdep_assert_held(&req->ctx->uring_lock);
+
+ head = xa_load(&req->ctx->io_buffers, bgid);
+ if (head) {
+ if (!list_empty(&head->list)) {
+ kbuf = list_last_entry(&head->list, struct io_buffer,
+ list);
+ list_del(&kbuf->list);
+ } else {
+ kbuf = head;
+ xa_erase(&req->ctx->io_buffers, bgid);
+ }
+ if (*len > kbuf->len)
+ *len = kbuf->len;
+ } else {
+ kbuf = ERR_PTR(-ENOBUFS);
+ }
+
+ io_ring_submit_unlock(req->ctx, needs_lock);
+
+ return kbuf;
+}
+
+static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
+ bool needs_lock)
+{
+ struct io_buffer *kbuf;
+ u16 bgid;
+
+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
+ bgid = req->buf_index;
+ kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
+ if (IS_ERR(kbuf))
+ return kbuf;
+ req->rw.addr = (u64) (unsigned long) kbuf;
+ req->flags |= REQ_F_BUFFER_SELECTED;
+ return u64_to_user_ptr(kbuf->addr);
+}
+
+#ifdef CONFIG_COMPAT
+static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
+ bool needs_lock)
+{
+ struct compat_iovec __user *uiov;
+ compat_ssize_t clen;
+ void __user *buf;
+ ssize_t len;
+
+ uiov = u64_to_user_ptr(req->rw.addr);
+ if (!access_ok(uiov, sizeof(*uiov)))
+ return -EFAULT;
+ if (__get_user(clen, &uiov->iov_len))
+ return -EFAULT;
+ if (clen < 0)
+ return -EINVAL;
+
+ len = clen;
+ buf = io_rw_buffer_select(req, &len, needs_lock);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+ iov[0].iov_base = buf;
+ iov[0].iov_len = (compat_size_t) len;
+ return 0;
+}
+#endif
+
+static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
+ bool needs_lock)
+{
+ struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
+ void __user *buf;
+ ssize_t len;
+
+ if (copy_from_user(iov, uiov, sizeof(*uiov)))
+ return -EFAULT;
+
+ len = iov[0].iov_len;
+ if (len < 0)
+ return -EINVAL;
+ buf = io_rw_buffer_select(req, &len, needs_lock);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+ iov[0].iov_base = buf;
+ iov[0].iov_len = len;
+ return 0;
+}
+
+static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
+ bool needs_lock)
+{
+ if (req->flags & REQ_F_BUFFER_SELECTED) {
+ struct io_buffer *kbuf;
+
+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
+ iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
+ iov[0].iov_len = kbuf->len;
+ return 0;
+ }
+ if (req->rw.len != 1)
+ return -EINVAL;
+
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ return io_compat_import(req, iov, needs_lock);
+#endif
+
+ return __io_iov_buffer_select(req, iov, needs_lock);
+}
+
+static int io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec,
+ struct iov_iter *iter, bool needs_lock)
+{
+ void __user *buf = u64_to_user_ptr(req->rw.addr);
+ size_t sqe_len = req->rw.len;
+ u8 opcode = req->opcode;
+ ssize_t ret;
+
+ if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
+ *iovec = NULL;
+ return io_import_fixed(req, rw, iter);
+ }
+
+ /* buffer index only valid with fixed read/write, or buffer select */
+ if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))
+ return -EINVAL;
+
+ if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+ req->rw.len = sqe_len;
+ }
+
+ ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
+ *iovec = NULL;
+ return ret;
+ }
+
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ ret = io_iov_buffer_select(req, *iovec, needs_lock);
+ if (!ret)
+ iov_iter_init(iter, rw, *iovec, 1, (*iovec)->iov_len);
+ *iovec = NULL;
+ return ret;
+ }
+
+ return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter,
+ req->ctx->compat);
+}
+
+static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
+{
+ return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos;
+}
+
+/*
+ * For files that don't have ->read_iter() and ->write_iter(), handle them
+ * by looping over ->read() or ->write() manually.
+ */
+static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter)
+{
+ struct kiocb *kiocb = &req->rw.kiocb;
+ struct file *file = req->file;
+ ssize_t ret = 0;
+
+ /*
+ * Don't support polled IO through this interface, and we can't
+ * support non-blocking either. For the latter, this just causes
+ * the kiocb to be handled from an async context.
+ */
+ if (kiocb->ki_flags & IOCB_HIPRI)
+ return -EOPNOTSUPP;
+ if (kiocb->ki_flags & IOCB_NOWAIT)
+ return -EAGAIN;
+
+ while (iov_iter_count(iter)) {
+ struct iovec iovec;
+ ssize_t nr;
+
+ if (!iov_iter_is_bvec(iter)) {
+ iovec = iov_iter_iovec(iter);
+ } else {
+ iovec.iov_base = u64_to_user_ptr(req->rw.addr);
+ iovec.iov_len = req->rw.len;
+ }
+
+ if (rw == READ) {
+ nr = file->f_op->read(file, iovec.iov_base,
+ iovec.iov_len, io_kiocb_ppos(kiocb));
+ } else {
+ nr = file->f_op->write(file, iovec.iov_base,
+ iovec.iov_len, io_kiocb_ppos(kiocb));
+ }
+
+ if (nr < 0) {
+ if (!ret)
+ ret = nr;
+ break;
+ }
+ ret += nr;
+ if (!iov_iter_is_bvec(iter)) {
+ iov_iter_advance(iter, nr);
+ } else {
+ req->rw.addr += nr;
+ req->rw.len -= nr;
+ if (!req->rw.len)
+ break;
+ }
+ if (nr != iovec.iov_len)
+ break;
+ }
+
+ return ret;
+}
+
+static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
+ const struct iovec *fast_iov, struct iov_iter *iter)
+{
+ struct io_async_rw *rw = req->async_data;
+
+ memcpy(&rw->iter, iter, sizeof(*iter));
+ rw->free_iovec = iovec;
+ rw->bytes_done = 0;
+ /* can only be fixed buffers, no need to do anything */
+ if (iov_iter_is_bvec(iter))
+ return;
+ if (!iovec) {
+ unsigned iov_off = 0;
+
+ rw->iter.iov = rw->fast_iov;
+ if (iter->iov != fast_iov) {
+ iov_off = iter->iov - fast_iov;
+ rw->iter.iov += iov_off;
+ }
+ if (rw->fast_iov != fast_iov)
+ memcpy(rw->fast_iov + iov_off, fast_iov + iov_off,
+ sizeof(struct iovec) * iter->nr_segs);
+ } else {
+ req->flags |= REQ_F_NEED_CLEANUP;
+ }
+}
+
+static inline int io_alloc_async_data(struct io_kiocb *req)
+{
+ WARN_ON_ONCE(!io_op_defs[req->opcode].async_size);
+ req->async_data = kmalloc(io_op_defs[req->opcode].async_size, GFP_KERNEL);
+ return req->async_data == NULL;
+}
+
+static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
+ const struct iovec *fast_iov,
+ struct iov_iter *iter, bool force)
+{
+ if (!force && !io_op_defs[req->opcode].needs_async_setup)
+ return 0;
+ if (!req->async_data) {
+ struct io_async_rw *iorw;
+
+ if (io_alloc_async_data(req)) {
+ kfree(iovec);
+ return -ENOMEM;
+ }
+
+ io_req_map_rw(req, iovec, fast_iov, iter);
+ iorw = req->async_data;
+ /* we've copied and mapped the iter, ensure state is saved */
+ iov_iter_save_state(&iorw->iter, &iorw->iter_state);
+ }
+ return 0;
+}
+
+static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
+{
+ struct io_async_rw *iorw = req->async_data;
+ struct iovec *iov = iorw->fast_iov;
+ int ret;
+
+ ret = io_import_iovec(rw, req, &iov, &iorw->iter, false);
+ if (unlikely(ret < 0))
+ return ret;
+
+ iorw->bytes_done = 0;
+ iorw->free_iovec = iov;
+ if (iov)
+ req->flags |= REQ_F_NEED_CLEANUP;
+ iov_iter_save_state(&iorw->iter, &iorw->iter_state);
+ return 0;
+}
+
+static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (unlikely(!(req->file->f_mode & FMODE_READ)))
+ return -EBADF;
+ return io_prep_rw(req, sqe, READ);
+}
+
+/*
+ * This is our waitqueue callback handler, registered through lock_page_async()
+ * when we initially tried to do the IO with the iocb armed our waitqueue.
+ * This gets called when the page is unlocked, and we generally expect that to
+ * happen when the page IO is completed and the page is now uptodate. This will
+ * queue a task_work based retry of the operation, attempting to copy the data
+ * again. If the latter fails because the page was NOT uptodate, then we will
+ * do a thread based blocking retry of the operation. That's the unexpected
+ * slow path.
+ */
+static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
+ int sync, void *arg)
+{
+ struct wait_page_queue *wpq;
+ struct io_kiocb *req = wait->private;
+ struct wait_page_key *key = arg;
+
+ wpq = container_of(wait, struct wait_page_queue, wait);
+
+ if (!wake_page_match(wpq, key))
+ return 0;
+
+ req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
+ list_del_init(&wait->entry);
+ io_req_task_queue(req);
+ return 1;
+}
+
+/*
+ * This controls whether a given IO request should be armed for async page
+ * based retry. If we return false here, the request is handed to the async
+ * worker threads for retry. If we're doing buffered reads on a regular file,
+ * we prepare a private wait_page_queue entry and retry the operation. This
+ * will either succeed because the page is now uptodate and unlocked, or it
+ * will register a callback when the page is unlocked at IO completion. Through
+ * that callback, io_uring uses task_work to setup a retry of the operation.
+ * That retry will attempt the buffered read again. The retry will generally
+ * succeed, or in rare cases where it fails, we then fall back to using the
+ * async worker threads for a blocking retry.
+ */
+static bool io_rw_should_retry(struct io_kiocb *req)
+{
+ struct io_async_rw *rw = req->async_data;
+ struct wait_page_queue *wait = &rw->wpq;
+ struct kiocb *kiocb = &req->rw.kiocb;
+
+ /* never retry for NOWAIT, we just complete with -EAGAIN */
+ if (req->flags & REQ_F_NOWAIT)
+ return false;
+
+ /* Only for buffered IO */
+ if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))
+ return false;
+
+ /*
+ * just use poll if we can, and don't attempt if the fs doesn't
+ * support callback based unlocks
+ */
+ if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
+ return false;
+
+ wait->wait.func = io_async_buf_func;
+ wait->wait.private = req;
+ wait->wait.flags = 0;
+ INIT_LIST_HEAD(&wait->wait.entry);
+ kiocb->ki_flags |= IOCB_WAITQ;
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
+ kiocb->ki_waitq = wait;
+ return true;
+}
+
+static inline int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter)
+{
+ if (req->file->f_op->read_iter)
+ return call_read_iter(req->file, &req->rw.kiocb, iter);
+ else if (req->file->f_op->read)
+ return loop_rw_iter(READ, req, iter);
+ else
+ return -EINVAL;
+}
+
+static bool need_read_all(struct io_kiocb *req)
+{
+ return req->flags & REQ_F_ISREG ||
+ S_ISBLK(file_inode(req->file)->i_mode);
+}
+
+static int io_read(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
+ struct kiocb *kiocb = &req->rw.kiocb;
+ struct iov_iter __iter, *iter = &__iter;
+ struct io_async_rw *rw = req->async_data;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ struct iov_iter_state __state, *state;
+ ssize_t ret, ret2;
+
+ if (rw) {
+ iter = &rw->iter;
+ state = &rw->iter_state;
+ /*
+ * We come here from an earlier attempt, restore our state to
+ * match in case it doesn't. It's cheap enough that we don't
+ * need to make this conditional.
+ */
+ iov_iter_restore(iter, state);
+ iovec = NULL;
+ } else {
+ ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock);
+ if (ret < 0)
+ return ret;
+ state = &__state;
+ iov_iter_save_state(iter, state);
+ }
+ req->result = iov_iter_count(iter);
+
+ /* Ensure we clear previously set non-block flag */
+ if (!force_nonblock)
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
+ else
+ kiocb->ki_flags |= IOCB_NOWAIT;
+
+ /* If the file doesn't support async, just async punt */
+ if (force_nonblock && !io_file_supports_nowait(req, READ)) {
+ ret = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
+ return ret ?: -EAGAIN;
+ }
+
+ ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), req->result);
+ if (unlikely(ret)) {
+ kfree(iovec);
+ return ret;
+ }
+
+ ret = io_iter_do_read(req, iter);
+
+ if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) {
+ req->flags &= ~REQ_F_REISSUE;
+ /* IOPOLL retry should happen for io-wq threads */
+ if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
+ goto done;
+ /* no retry on NONBLOCK nor RWF_NOWAIT */
+ if (req->flags & REQ_F_NOWAIT)
+ goto done;
+ ret = 0;
+ } else if (ret == -EIOCBQUEUED) {
+ goto out_free;
+ } else if (ret <= 0 || ret == req->result || !force_nonblock ||
+ (req->flags & REQ_F_NOWAIT) || !need_read_all(req)) {
+ /* read all, failed, already did sync or don't want to retry */
+ goto done;
+ }
+
+ /*
+ * Don't depend on the iter state matching what was consumed, or being
+ * untouched in case of error. Restore it and we'll advance it
+ * manually if we need to.
+ */
+ iov_iter_restore(iter, state);
+
+ ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
+ if (ret2)
+ return ret2;
+
+ iovec = NULL;
+ rw = req->async_data;
+ /*
+ * Now use our persistent iterator and state, if we aren't already.
+ * We've restored and mapped the iter to match.
+ */
+ if (iter != &rw->iter) {
+ iter = &rw->iter;
+ state = &rw->iter_state;
+ }
+
+ do {
+ /*
+ * We end up here because of a partial read, either from
+ * above or inside this loop. Advance the iter by the bytes
+ * that were consumed.
+ */
+ iov_iter_advance(iter, ret);
+ if (!iov_iter_count(iter))
+ break;
+ rw->bytes_done += ret;
+ iov_iter_save_state(iter, state);
+
+ /* if we can retry, do so with the callbacks armed */
+ if (!io_rw_should_retry(req)) {
+ kiocb->ki_flags &= ~IOCB_WAITQ;
+ return -EAGAIN;
+ }
+
+ req->result = iov_iter_count(iter);
+ /*
+ * Now retry read with the IOCB_WAITQ parts set in the iocb. If
+ * we get -EIOCBQUEUED, then we'll get a notification when the
+ * desired page gets unlocked. We can also get a partial read
+ * here, and if we do, then just retry at the new offset.
+ */
+ ret = io_iter_do_read(req, iter);
+ if (ret == -EIOCBQUEUED)
+ return 0;
+ /* we got some bytes, but not all. retry. */
+ kiocb->ki_flags &= ~IOCB_WAITQ;
+ iov_iter_restore(iter, state);
+ } while (ret > 0);
+done:
+ kiocb_done(kiocb, ret, issue_flags);
+out_free:
+ /* it's faster to check here then delegate to kfree */
+ if (iovec)
+ kfree(iovec);
+ return 0;
+}
+
+static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
+ return -EBADF;
+ return io_prep_rw(req, sqe, WRITE);
+}
+
+static int io_write(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
+ struct kiocb *kiocb = &req->rw.kiocb;
+ struct iov_iter __iter, *iter = &__iter;
+ struct io_async_rw *rw = req->async_data;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ struct iov_iter_state __state, *state;
+ ssize_t ret, ret2;
+
+ if (rw) {
+ iter = &rw->iter;
+ state = &rw->iter_state;
+ iov_iter_restore(iter, state);
+ iovec = NULL;
+ } else {
+ ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock);
+ if (ret < 0)
+ return ret;
+ state = &__state;
+ iov_iter_save_state(iter, state);
+ }
+ req->result = iov_iter_count(iter);
+
+ /* Ensure we clear previously set non-block flag */
+ if (!force_nonblock)
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
+ else
+ kiocb->ki_flags |= IOCB_NOWAIT;
+
+ /* If the file doesn't support async, just async punt */
+ if (force_nonblock && !io_file_supports_nowait(req, WRITE))
+ goto copy_iov;
+
+ /* file path doesn't support NOWAIT for non-direct_IO */
+ if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
+ (req->flags & REQ_F_ISREG))
+ goto copy_iov;
+
+ ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result);
+ if (unlikely(ret))
+ goto out_free;
+
+ /*
+ * Open-code file_start_write here to grab freeze protection,
+ * which will be released by another thread in
+ * io_complete_rw(). Fool lockdep by telling it the lock got
+ * released so that it doesn't complain about the held lock when
+ * we return to userspace.
+ */
+ if (req->flags & REQ_F_ISREG) {
+ sb_start_write(file_inode(req->file)->i_sb);
+ __sb_writers_release(file_inode(req->file)->i_sb,
+ SB_FREEZE_WRITE);
+ }
+ kiocb->ki_flags |= IOCB_WRITE;
+
+ if (req->file->f_op->write_iter)
+ ret2 = call_write_iter(req->file, kiocb, iter);
+ else if (req->file->f_op->write)
+ ret2 = loop_rw_iter(WRITE, req, iter);
+ else
+ ret2 = -EINVAL;
+
+ if (req->flags & REQ_F_REISSUE) {
+ req->flags &= ~REQ_F_REISSUE;
+ ret2 = -EAGAIN;
+ }
+
+ /*
+ * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
+ * retry them without IOCB_NOWAIT.
+ */
+ if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
+ ret2 = -EAGAIN;
+ /* no retry on NONBLOCK nor RWF_NOWAIT */
+ if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT))
+ goto done;
+ if (!force_nonblock || ret2 != -EAGAIN) {
+ /* IOPOLL retry should happen for io-wq threads */
+ if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
+ goto copy_iov;
+done:
+ kiocb_done(kiocb, ret2, issue_flags);
+ } else {
+copy_iov:
+ iov_iter_restore(iter, state);
+ ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
+ if (!ret) {
+ if (kiocb->ki_flags & IOCB_WRITE)
+ kiocb_end_write(req);
+ return -EAGAIN;
+ }
+ return ret;
+ }
+out_free:
+ /* it's reportedly faster than delegating the null check to kfree() */
+ if (iovec)
+ kfree(iovec);
+ return ret;
+}
+
+static int io_renameat_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_rename *ren = &req->rename;
+ const char __user *oldf, *newf;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
+ return -EBADF;
+
+ ren->old_dfd = READ_ONCE(sqe->fd);
+ oldf = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ newf = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ ren->new_dfd = READ_ONCE(sqe->len);
+ ren->flags = READ_ONCE(sqe->rename_flags);
+
+ ren->oldpath = getname(oldf);
+ if (IS_ERR(ren->oldpath))
+ return PTR_ERR(ren->oldpath);
+
+ ren->newpath = getname(newf);
+ if (IS_ERR(ren->newpath)) {
+ putname(ren->oldpath);
+ return PTR_ERR(ren->newpath);
+ }
+
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return 0;
+}
+
+static int io_renameat(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_rename *ren = &req->rename;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = do_renameat2(ren->old_dfd, ren->oldpath, ren->new_dfd,
+ ren->newpath, ren->flags);
+
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_unlinkat_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_unlink *un = &req->unlink;
+ const char __user *fname;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
+ return -EBADF;
+
+ un->dfd = READ_ONCE(sqe->fd);
+
+ un->flags = READ_ONCE(sqe->unlink_flags);
+ if (un->flags & ~AT_REMOVEDIR)
+ return -EINVAL;
+
+ fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ un->filename = getname(fname);
+ if (IS_ERR(un->filename))
+ return PTR_ERR(un->filename);
+
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return 0;
+}
+
+static int io_unlinkat(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_unlink *un = &req->unlink;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ if (un->flags & AT_REMOVEDIR)
+ ret = do_rmdir(un->dfd, un->filename);
+ else
+ ret = do_unlinkat(un->dfd, un->filename);
+
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_shutdown_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_NET)
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->ioprio || sqe->off || sqe->addr || sqe->rw_flags ||
+ sqe->buf_index || sqe->splice_fd_in))
+ return -EINVAL;
+
+ req->shutdown.how = READ_ONCE(sqe->len);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
+{
+#if defined(CONFIG_NET)
+ struct socket *sock;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ ret = __sys_shutdown_sock(sock, req->shutdown.how);
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int __io_splice_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_splice *sp = &req->splice;
+ unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ sp->len = READ_ONCE(sqe->len);
+ sp->flags = READ_ONCE(sqe->splice_flags);
+ if (unlikely(sp->flags & ~valid_flags))
+ return -EINVAL;
+ sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in);
+ return 0;
+}
+
+static int io_tee_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
+ return -EINVAL;
+ return __io_splice_prep(req, sqe);
+}
+
+static int io_tee(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_splice *sp = &req->splice;
+ struct file *out = sp->file_out;
+ unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
+ struct file *in;
+ long ret = 0;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ in = io_file_get(req->ctx, req, sp->splice_fd_in,
+ (sp->flags & SPLICE_F_FD_IN_FIXED));
+ if (!in) {
+ ret = -EBADF;
+ goto done;
+ }
+
+ if (sp->len)
+ ret = do_tee(in, out, sp->len, flags);
+
+ if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
+ io_put_file(in);
+done:
+ if (ret != sp->len)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_splice *sp = &req->splice;
+
+ sp->off_in = READ_ONCE(sqe->splice_off_in);
+ sp->off_out = READ_ONCE(sqe->off);
+ return __io_splice_prep(req, sqe);
+}
+
+static int io_splice(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_splice *sp = &req->splice;
+ struct file *out = sp->file_out;
+ unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
+ loff_t *poff_in, *poff_out;
+ struct file *in;
+ long ret = 0;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ in = io_file_get(req->ctx, req, sp->splice_fd_in,
+ (sp->flags & SPLICE_F_FD_IN_FIXED));
+ if (!in) {
+ ret = -EBADF;
+ goto done;
+ }
+
+ poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
+ poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
+
+ if (sp->len)
+ ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
+
+ if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
+ io_put_file(in);
+done:
+ if (ret != sp->len)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+/*
+ * IORING_OP_NOP just posts a completion event, nothing else.
+ */
+static int io_nop(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ __io_req_complete(req, issue_flags, 0, 0);
+ return 0;
+}
+
+static int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
+ sqe->splice_fd_in))
+ return -EINVAL;
+
+ req->sync.flags = READ_ONCE(sqe->fsync_flags);
+ if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC))
+ return -EINVAL;
+
+ req->sync.off = READ_ONCE(sqe->off);
+ req->sync.len = READ_ONCE(sqe->len);
+ return 0;
+}
+
+static int io_fsync(struct io_kiocb *req, unsigned int issue_flags)
+{
+ loff_t end = req->sync.off + req->sync.len;
+ int ret;
+
+ /* fsync always requires a blocking context */
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = vfs_fsync_range(req->file, req->sync.off,
+ end > 0 ? end : LLONG_MAX,
+ req->sync.flags & IORING_FSYNC_DATASYNC);
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_fallocate_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (sqe->ioprio || sqe->buf_index || sqe->rw_flags ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ req->sync.off = READ_ONCE(sqe->off);
+ req->sync.len = READ_ONCE(sqe->addr);
+ req->sync.mode = READ_ONCE(sqe->len);
+ return 0;
+}
+
+static int io_fallocate(struct io_kiocb *req, unsigned int issue_flags)
+{
+ int ret;
+
+ /* fallocate always requiring blocking context */
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+ ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
+ req->sync.len);
+ if (ret < 0)
+ req_set_fail(req);
+ else
+ fsnotify_modify(req->file);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ const char __user *fname;
+ int ret;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->ioprio || sqe->buf_index))
+ return -EINVAL;
+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
+ return -EBADF;
+
+ /* open.how should be already initialised */
+ if (!(req->open.how.flags & O_PATH) && force_o_largefile())
+ req->open.how.flags |= O_LARGEFILE;
+
+ req->open.dfd = READ_ONCE(sqe->fd);
+ fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ req->open.filename = getname(fname);
+ if (IS_ERR(req->open.filename)) {
+ ret = PTR_ERR(req->open.filename);
+ req->open.filename = NULL;
+ return ret;
+ }
+
+ req->open.file_slot = READ_ONCE(sqe->file_index);
+ if (req->open.file_slot && (req->open.how.flags & O_CLOEXEC))
+ return -EINVAL;
+
+ req->open.nofile = rlimit(RLIMIT_NOFILE);
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return 0;
+}
+
+static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ u64 mode = READ_ONCE(sqe->len);
+ u64 flags = READ_ONCE(sqe->open_flags);
+
+ req->open.how = build_open_how(flags, mode);
+ return __io_openat_prep(req, sqe);
+}
+
+static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct open_how __user *how;
+ size_t len;
+ int ret;
+
+ how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ len = READ_ONCE(sqe->len);
+ if (len < OPEN_HOW_SIZE_VER0)
+ return -EINVAL;
+
+ ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
+ len);
+ if (ret)
+ return ret;
+
+ return __io_openat_prep(req, sqe);
+}
+
+static int io_openat2(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct open_flags op;
+ struct file *file;
+ bool resolve_nonblock, nonblock_set;
+ bool fixed = !!req->open.file_slot;
+ int ret;
+
+ ret = build_open_flags(&req->open.how, &op);
+ if (ret)
+ goto err;
+ nonblock_set = op.open_flag & O_NONBLOCK;
+ resolve_nonblock = req->open.how.resolve & RESOLVE_CACHED;
+ if (issue_flags & IO_URING_F_NONBLOCK) {
+ /*
+ * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open,
+ * it'll always -EAGAIN
+ */
+ if (req->open.how.flags & (O_TRUNC | O_CREAT | O_TMPFILE))
+ return -EAGAIN;
+ op.lookup_flags |= LOOKUP_CACHED;
+ op.open_flag |= O_NONBLOCK;
+ }
+
+ if (!fixed) {
+ ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
+ if (ret < 0)
+ goto err;
+ }
+
+ file = do_filp_open(req->open.dfd, req->open.filename, &op);
+ if (IS_ERR(file)) {
+ /*
+ * We could hang on to this 'fd' on retrying, but seems like
+ * marginal gain for something that is now known to be a slower
+ * path. So just put it, and we'll get a new one when we retry.
+ */
+ if (!fixed)
+ put_unused_fd(ret);
+
+ ret = PTR_ERR(file);
+ /* only retry if RESOLVE_CACHED wasn't already set by application */
+ if (ret == -EAGAIN &&
+ (!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK)))
+ return -EAGAIN;
+ goto err;
+ }
+
+ if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set)
+ file->f_flags &= ~O_NONBLOCK;
+ fsnotify_open(file);
+
+ if (!fixed)
+ fd_install(ret, file);
+ else
+ ret = io_install_fixed_file(req, file, issue_flags,
+ req->open.file_slot - 1);
+err:
+ putname(req->open.filename);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_openat(struct io_kiocb *req, unsigned int issue_flags)
+{
+ return io_openat2(req, issue_flags);
+}
+
+static int io_remove_buffers_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_provide_buf *p = &req->pbuf;
+ u64 tmp;
+
+ if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+
+ tmp = READ_ONCE(sqe->fd);
+ if (!tmp || tmp > USHRT_MAX)
+ return -EINVAL;
+
+ memset(p, 0, sizeof(*p));
+ p->nbufs = tmp;
+ p->bgid = READ_ONCE(sqe->buf_group);
+ return 0;
+}
+
+static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
+ int bgid, unsigned nbufs)
+{
+ unsigned i = 0;
+
+ /* shouldn't happen */
+ if (!nbufs)
+ return 0;
+
+ /* the head kbuf is the list itself */
+ while (!list_empty(&buf->list)) {
+ struct io_buffer *nxt;
+
+ nxt = list_first_entry(&buf->list, struct io_buffer, list);
+ list_del(&nxt->list);
+ kfree(nxt);
+ if (++i == nbufs)
+ return i;
+ cond_resched();
+ }
+ i++;
+ kfree(buf);
+ xa_erase(&ctx->io_buffers, bgid);
+
+ return i;
+}
+
+static int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_provide_buf *p = &req->pbuf;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_buffer *head;
+ int ret = 0;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ io_ring_submit_lock(ctx, !force_nonblock);
+
+ lockdep_assert_held(&ctx->uring_lock);
+
+ ret = -ENOENT;
+ head = xa_load(&ctx->io_buffers, p->bgid);
+ if (head)
+ ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
+ if (ret < 0)
+ req_set_fail(req);
+
+ /* complete before unlock, IOPOLL may need the lock */
+ __io_req_complete(req, issue_flags, ret, 0);
+ io_ring_submit_unlock(ctx, !force_nonblock);
+ return 0;
+}
+
+static int io_provide_buffers_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ unsigned long size, tmp_check;
+ struct io_provide_buf *p = &req->pbuf;
+ u64 tmp;
+
+ if (sqe->ioprio || sqe->rw_flags || sqe->splice_fd_in)
+ return -EINVAL;
+
+ tmp = READ_ONCE(sqe->fd);
+ if (!tmp || tmp > USHRT_MAX)
+ return -E2BIG;
+ p->nbufs = tmp;
+ p->addr = READ_ONCE(sqe->addr);
+ p->len = READ_ONCE(sqe->len);
+
+ if (check_mul_overflow((unsigned long)p->len, (unsigned long)p->nbufs,
+ &size))
+ return -EOVERFLOW;
+ if (check_add_overflow((unsigned long)p->addr, size, &tmp_check))
+ return -EOVERFLOW;
+
+ size = (unsigned long)p->len * p->nbufs;
+ if (!access_ok(u64_to_user_ptr(p->addr), size))
+ return -EFAULT;
+
+ p->bgid = READ_ONCE(sqe->buf_group);
+ tmp = READ_ONCE(sqe->off);
+ if (tmp > USHRT_MAX)
+ return -E2BIG;
+ p->bid = tmp;
+ return 0;
+}
+
+static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
+{
+ struct io_buffer *buf;
+ u64 addr = pbuf->addr;
+ int i, bid = pbuf->bid;
+
+ for (i = 0; i < pbuf->nbufs; i++) {
+ buf = kmalloc(sizeof(*buf), GFP_KERNEL_ACCOUNT);
+ if (!buf)
+ break;
+
+ buf->addr = addr;
+ buf->len = min_t(__u32, pbuf->len, MAX_RW_COUNT);
+ buf->bid = bid;
+ addr += pbuf->len;
+ bid++;
+ if (!*head) {
+ INIT_LIST_HEAD(&buf->list);
+ *head = buf;
+ } else {
+ list_add_tail(&buf->list, &(*head)->list);
+ }
+ cond_resched();
+ }
+
+ return i ? i : -ENOMEM;
+}
+
+static int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_provide_buf *p = &req->pbuf;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_buffer *head, *list;
+ int ret = 0;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ io_ring_submit_lock(ctx, !force_nonblock);
+
+ lockdep_assert_held(&ctx->uring_lock);
+
+ list = head = xa_load(&ctx->io_buffers, p->bgid);
+
+ ret = io_add_buffers(p, &head);
+ if (ret >= 0 && !list) {
+ ret = xa_insert(&ctx->io_buffers, p->bgid, head,
+ GFP_KERNEL_ACCOUNT);
+ if (ret < 0)
+ __io_remove_buffers(ctx, head, p->bgid, -1U);
+ }
+ if (ret < 0)
+ req_set_fail(req);
+ /* complete before unlock, IOPOLL may need the lock */
+ __io_req_complete(req, issue_flags, ret, 0);
+ io_ring_submit_unlock(ctx, !force_nonblock);
+ return 0;
+}
+
+static int io_epoll_ctl_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_EPOLL)
+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ req->epoll.epfd = READ_ONCE(sqe->fd);
+ req->epoll.op = READ_ONCE(sqe->len);
+ req->epoll.fd = READ_ONCE(sqe->off);
+
+ if (ep_op_has_event(req->epoll.op)) {
+ struct epoll_event __user *ev;
+
+ ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
+ return -EFAULT;
+ }
+
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
+{
+#if defined(CONFIG_EPOLL)
+ struct io_epoll *ie = &req->epoll;
+ int ret;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
+ if (force_nonblock && ret == -EAGAIN)
+ return -EAGAIN;
+
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
+ if (sqe->ioprio || sqe->buf_index || sqe->off || sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ req->madvise.addr = READ_ONCE(sqe->addr);
+ req->madvise.len = READ_ONCE(sqe->len);
+ req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_madvise(struct io_kiocb *req, unsigned int issue_flags)
+{
+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
+ struct io_madvise *ma = &req->madvise;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice);
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (sqe->ioprio || sqe->buf_index || sqe->addr || sqe->splice_fd_in)
+ return -EINVAL;
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+
+ req->fadvise.offset = READ_ONCE(sqe->off);
+ req->fadvise.len = READ_ONCE(sqe->len);
+ req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
+ return 0;
+}
+
+static int io_fadvise(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_fadvise *fa = &req->fadvise;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK) {
+ switch (fa->advice) {
+ case POSIX_FADV_NORMAL:
+ case POSIX_FADV_RANDOM:
+ case POSIX_FADV_SEQUENTIAL:
+ break;
+ default:
+ return -EAGAIN;
+ }
+ }
+
+ ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
+ return -EINVAL;
+ if (req->flags & REQ_F_FIXED_FILE)
+ return -EBADF;
+
+ req->statx.dfd = READ_ONCE(sqe->fd);
+ req->statx.mask = READ_ONCE(sqe->len);
+ req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ req->statx.flags = READ_ONCE(sqe->statx_flags);
+
+ return 0;
+}
+
+static int io_statx(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_statx *ctx = &req->statx;
+ int ret;
+
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask,
+ ctx->buffer);
+
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
+ sqe->rw_flags || sqe->buf_index)
+ return -EINVAL;
+ if (req->flags & REQ_F_FIXED_FILE)
+ return -EBADF;
+
+ req->close.fd = READ_ONCE(sqe->fd);
+ req->close.file_slot = READ_ONCE(sqe->file_index);
+ if (req->close.file_slot && req->close.fd)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int io_close(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct files_struct *files = current->files;
+ struct io_close *close = &req->close;
+ struct fdtable *fdt;
+ struct file *file = NULL;
+ int ret = -EBADF;
+
+ if (req->close.file_slot) {
+ ret = io_close_fixed(req, issue_flags);
+ goto err;
+ }
+
+ spin_lock(&files->file_lock);
+ fdt = files_fdtable(files);
+ if (close->fd >= fdt->max_fds) {
+ spin_unlock(&files->file_lock);
+ goto err;
+ }
+ file = fdt->fd[close->fd];
+ if (!file || file->f_op == &io_uring_fops) {
+ spin_unlock(&files->file_lock);
+ file = NULL;
+ goto err;
+ }
+
+ /* if the file has a flush method, be safe and punt to async */
+ if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) {
+ spin_unlock(&files->file_lock);
+ return -EAGAIN;
+ }
+
+ ret = __close_fd_get_file(close->fd, &file);
+ spin_unlock(&files->file_lock);
+ if (ret < 0) {
+ if (ret == -ENOENT)
+ ret = -EBADF;
+ goto err;
+ }
+
+ /* No ->flush() or already async, safely close from here */
+ ret = filp_close(file, current->files);
+err:
+ if (ret < 0)
+ req_set_fail(req);
+ if (file)
+ fput(file);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_sfr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
+ sqe->splice_fd_in))
+ return -EINVAL;
+
+ req->sync.off = READ_ONCE(sqe->off);
+ req->sync.len = READ_ONCE(sqe->len);
+ req->sync.flags = READ_ONCE(sqe->sync_range_flags);
+ return 0;
+}
+
+static int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags)
+{
+ int ret;
+
+ /* sync_file_range always requires a blocking context */
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ return -EAGAIN;
+
+ ret = sync_file_range(req->file, req->sync.off, req->sync.len,
+ req->sync.flags);
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete(req, ret);
+ return 0;
+}
+
+#if defined(CONFIG_NET)
+static int io_setup_async_msg(struct io_kiocb *req,
+ struct io_async_msghdr *kmsg)
+{
+ struct io_async_msghdr *async_msg = req->async_data;
+
+ if (async_msg)
+ return -EAGAIN;
+ if (io_alloc_async_data(req)) {
+ kfree(kmsg->free_iov);
+ return -ENOMEM;
+ }
+ async_msg = req->async_data;
+ req->flags |= REQ_F_NEED_CLEANUP;
+ memcpy(async_msg, kmsg, sizeof(*kmsg));
+ if (async_msg->msg.msg_name)
+ async_msg->msg.msg_name = &async_msg->addr;
+ /* if were using fast_iov, set it to the new one */
+ if (!async_msg->free_iov)
+ async_msg->msg.msg_iter.iov = async_msg->fast_iov;
+
+ return -EAGAIN;
+}
+
+static int io_sendmsg_copy_hdr(struct io_kiocb *req,
+ struct io_async_msghdr *iomsg)
+{
+ iomsg->msg.msg_name = &iomsg->addr;
+ iomsg->free_iov = iomsg->fast_iov;
+ return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg,
+ req->sr_msg.msg_flags, &iomsg->free_iov);
+}
+
+static int io_sendmsg_prep_async(struct io_kiocb *req)
+{
+ int ret;
+
+ ret = io_sendmsg_copy_hdr(req, req->async_data);
+ if (!ret)
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return ret;
+}
+
+static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->addr2 || sqe->file_index))
+ return -EINVAL;
+ if (unlikely(sqe->addr2 || sqe->file_index || sqe->ioprio))
+ return -EINVAL;
+
+ sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ sr->len = READ_ONCE(sqe->len);
+ sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
+ if (sr->msg_flags & MSG_DONTWAIT)
+ req->flags |= REQ_F_NOWAIT;
+
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ sr->msg_flags |= MSG_CMSG_COMPAT;
+#endif
+ return 0;
+}
+
+static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_async_msghdr iomsg, *kmsg;
+ struct socket *sock;
+ unsigned flags;
+ int min_ret = 0;
+ int ret;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ kmsg = req->async_data;
+ if (!kmsg) {
+ ret = io_sendmsg_copy_hdr(req, &iomsg);
+ if (ret)
+ return ret;
+ kmsg = &iomsg;
+ }
+
+ flags = req->sr_msg.msg_flags;
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ flags |= MSG_DONTWAIT;
+ if (flags & MSG_WAITALL)
+ min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
+ ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
+ if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)
+ return io_setup_async_msg(req, kmsg);
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+
+ /* fast path, check for non-NULL to avoid function call */
+ if (kmsg->free_iov)
+ kfree(kmsg->free_iov);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < min_ret)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_send(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct msghdr msg;
+ struct iovec iov;
+ struct socket *sock;
+ unsigned flags;
+ int min_ret = 0;
+ int ret;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
+ if (unlikely(ret))
+ return ret;
+
+ msg.msg_name = NULL;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_namelen = 0;
+
+ flags = req->sr_msg.msg_flags;
+ if (issue_flags & IO_URING_F_NONBLOCK)
+ flags |= MSG_DONTWAIT;
+ if (flags & MSG_WAITALL)
+ min_ret = iov_iter_count(&msg.msg_iter);
+
+ msg.msg_flags = flags;
+ ret = sock_sendmsg(sock, &msg);
+ if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)
+ return -EAGAIN;
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+
+ if (ret < min_ret)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
+ struct io_async_msghdr *iomsg)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct iovec __user *uiov;
+ size_t iov_len;
+ int ret;
+
+ ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg,
+ &iomsg->uaddr, &uiov, &iov_len);
+ if (ret)
+ return ret;
+
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ if (iov_len > 1)
+ return -EINVAL;
+ if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov)))
+ return -EFAULT;
+ sr->len = iomsg->fast_iov[0].iov_len;
+ iomsg->free_iov = NULL;
+ } else {
+ iomsg->free_iov = iomsg->fast_iov;
+ ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
+ &iomsg->free_iov, &iomsg->msg.msg_iter,
+ false);
+ if (ret > 0)
+ ret = 0;
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
+ struct io_async_msghdr *iomsg)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct compat_iovec __user *uiov;
+ compat_uptr_t ptr;
+ compat_size_t len;
+ int ret;
+
+ ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr,
+ &ptr, &len);
+ if (ret)
+ return ret;
+
+ uiov = compat_ptr(ptr);
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ compat_ssize_t clen;
+
+ if (len > 1)
+ return -EINVAL;
+ if (!access_ok(uiov, sizeof(*uiov)))
+ return -EFAULT;
+ if (__get_user(clen, &uiov->iov_len))
+ return -EFAULT;
+ if (clen < 0)
+ return -EINVAL;
+ sr->len = clen;
+ iomsg->free_iov = NULL;
+ } else {
+ iomsg->free_iov = iomsg->fast_iov;
+ ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
+ UIO_FASTIOV, &iomsg->free_iov,
+ &iomsg->msg.msg_iter, true);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+#endif
+
+static int io_recvmsg_copy_hdr(struct io_kiocb *req,
+ struct io_async_msghdr *iomsg)
+{
+ iomsg->msg.msg_name = &iomsg->addr;
+
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ return __io_compat_recvmsg_copy_hdr(req, iomsg);
+#endif
+
+ return __io_recvmsg_copy_hdr(req, iomsg);
+}
+
+static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
+ bool needs_lock)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct io_buffer *kbuf;
+
+ kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
+ if (IS_ERR(kbuf))
+ return kbuf;
+
+ sr->kbuf = kbuf;
+ req->flags |= REQ_F_BUFFER_SELECTED;
+ return kbuf;
+}
+
+static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req)
+{
+ return io_put_kbuf(req, req->sr_msg.kbuf);
+}
+
+static int io_recvmsg_prep_async(struct io_kiocb *req)
+{
+ int ret;
+
+ ret = io_recvmsg_copy_hdr(req, req->async_data);
+ if (!ret)
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return ret;
+}
+
+static int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_sr_msg *sr = &req->sr_msg;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(sqe->addr2 || sqe->file_index))
+ return -EINVAL;
+ if (unlikely(sqe->addr2 || sqe->file_index || sqe->ioprio))
+ return -EINVAL;
+
+ sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ sr->len = READ_ONCE(sqe->len);
+ sr->bgid = READ_ONCE(sqe->buf_group);
+ sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
+ if (sr->msg_flags & MSG_DONTWAIT)
+ req->flags |= REQ_F_NOWAIT;
+
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ sr->msg_flags |= MSG_CMSG_COMPAT;
+#endif
+ return 0;
+}
+
+static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_async_msghdr iomsg, *kmsg;
+ struct socket *sock;
+ struct io_buffer *kbuf;
+ unsigned flags;
+ int min_ret = 0;
+ int ret, cflags = 0;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ kmsg = req->async_data;
+ if (!kmsg) {
+ ret = io_recvmsg_copy_hdr(req, &iomsg);
+ if (ret)
+ return ret;
+ kmsg = &iomsg;
+ }
+
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ kbuf = io_recv_buffer_select(req, !force_nonblock);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+ kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
+ kmsg->fast_iov[0].iov_len = req->sr_msg.len;
+ iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->fast_iov,
+ 1, req->sr_msg.len);
+ }
+
+ flags = req->sr_msg.msg_flags;
+ if (force_nonblock)
+ flags |= MSG_DONTWAIT;
+ if (flags & MSG_WAITALL)
+ min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
+ ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
+ kmsg->uaddr, flags);
+ if (force_nonblock && ret == -EAGAIN)
+ return io_setup_async_msg(req, kmsg);
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+
+ if (req->flags & REQ_F_BUFFER_SELECTED)
+ cflags = io_put_recv_kbuf(req);
+ /* fast path, check for non-NULL to avoid function call */
+ if (kmsg->free_iov)
+ kfree(kmsg->free_iov);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+ if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, cflags);
+ return 0;
+}
+
+static int io_recv(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_buffer *kbuf;
+ struct io_sr_msg *sr = &req->sr_msg;
+ struct msghdr msg;
+ void __user *buf = sr->buf;
+ struct socket *sock;
+ struct iovec iov;
+ unsigned flags;
+ int min_ret = 0;
+ int ret, cflags = 0;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ sock = sock_from_file(req->file, &ret);
+ if (unlikely(!sock))
+ return ret;
+
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ kbuf = io_recv_buffer_select(req, !force_nonblock);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+ buf = u64_to_user_ptr(kbuf->addr);
+ }
+
+ ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter);
+ if (unlikely(ret))
+ goto out_free;
+
+ msg.msg_name = NULL;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_namelen = 0;
+ msg.msg_iocb = NULL;
+ msg.msg_flags = 0;
+
+ flags = req->sr_msg.msg_flags;
+ if (force_nonblock)
+ flags |= MSG_DONTWAIT;
+ if (flags & MSG_WAITALL)
+ min_ret = iov_iter_count(&msg.msg_iter);
+
+ ret = sock_recvmsg(sock, &msg, flags);
+ if (force_nonblock && ret == -EAGAIN)
+ return -EAGAIN;
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+out_free:
+ if (req->flags & REQ_F_BUFFER_SELECTED)
+ cflags = io_put_recv_kbuf(req);
+ if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, cflags);
+ return 0;
+}
+
+static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_accept *accept = &req->accept;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->len || sqe->buf_index)
+ return -EINVAL;
+
+ accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+ accept->flags = READ_ONCE(sqe->accept_flags);
+ accept->nofile = rlimit(RLIMIT_NOFILE);
+
+ accept->file_slot = READ_ONCE(sqe->file_index);
+ if (accept->file_slot && (accept->flags & SOCK_CLOEXEC))
+ return -EINVAL;
+ if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
+ return -EINVAL;
+ if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
+ accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
+ return 0;
+}
+
+static int io_accept(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_accept *accept = &req->accept;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
+ bool fixed = !!accept->file_slot;
+ struct file *file;
+ int ret, fd;
+
+ if (req->file->f_flags & O_NONBLOCK)
+ req->flags |= REQ_F_NOWAIT;
+
+ if (!fixed) {
+ fd = __get_unused_fd_flags(accept->flags, accept->nofile);
+ if (unlikely(fd < 0))
+ return fd;
+ }
+ file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
+ accept->flags);
+
+ if (IS_ERR(file)) {
+ if (!fixed)
+ put_unused_fd(fd);
+ ret = PTR_ERR(file);
+ if (ret == -EAGAIN && force_nonblock)
+ return -EAGAIN;
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+ req_set_fail(req);
+ } else if (!fixed) {
+ fd_install(fd, file);
+ ret = fd;
+ } else {
+ ret = io_install_fixed_file(req, file, issue_flags,
+ accept->file_slot - 1);
+ }
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_connect_prep_async(struct io_kiocb *req)
+{
+ struct io_async_connect *io = req->async_data;
+ struct io_connect *conn = &req->connect;
+
+ return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address);
+}
+
+static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_connect *conn = &req->connect;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+
+ conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
+ conn->addr_len = READ_ONCE(sqe->addr2);
+ return 0;
+}
+
+static int io_connect(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_async_connect __io, *io;
+ unsigned file_flags;
+ int ret;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+ if (req->async_data) {
+ io = req->async_data;
+ } else {
+ ret = move_addr_to_kernel(req->connect.addr,
+ req->connect.addr_len,
+ &__io.address);
+ if (ret)
+ goto out;
+ io = &__io;
+ }
+
+ file_flags = force_nonblock ? O_NONBLOCK : 0;
+
+ ret = __sys_connect_file(req->file, &io->address,
+ req->connect.addr_len, file_flags);
+ if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
+ if (req->async_data)
+ return -EAGAIN;
+ if (io_alloc_async_data(req)) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ memcpy(req->async_data, &__io, sizeof(__io));
+ return -EAGAIN;
+ }
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+out:
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+#else /* !CONFIG_NET */
+#define IO_NETOP_FN(op) \
+static int io_##op(struct io_kiocb *req, unsigned int issue_flags) \
+{ \
+ return -EOPNOTSUPP; \
+}
+
+#define IO_NETOP_PREP(op) \
+IO_NETOP_FN(op) \
+static int io_##op##_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) \
+{ \
+ return -EOPNOTSUPP; \
+} \
+
+#define IO_NETOP_PREP_ASYNC(op) \
+IO_NETOP_PREP(op) \
+static int io_##op##_prep_async(struct io_kiocb *req) \
+{ \
+ return -EOPNOTSUPP; \
+}
+
+IO_NETOP_PREP_ASYNC(sendmsg);
+IO_NETOP_PREP_ASYNC(recvmsg);
+IO_NETOP_PREP_ASYNC(connect);
+IO_NETOP_PREP(accept);
+IO_NETOP_FN(send);
+IO_NETOP_FN(recv);
+#endif /* CONFIG_NET */
+
+struct io_poll_table {
+ struct poll_table_struct pt;
+ struct io_kiocb *req;
+ int nr_entries;
+ int error;
+};
+
+#define IO_POLL_CANCEL_FLAG BIT(31)
+#define IO_POLL_RETRY_FLAG BIT(30)
+#define IO_POLL_REF_MASK GENMASK(29, 0)
+
+/*
+ * We usually have 1-2 refs taken, 128 is more than enough and we want to
+ * maximise the margin between this amount and the moment when it overflows.
+ */
+#define IO_POLL_REF_BIAS 128
+
+static bool io_poll_get_ownership_slowpath(struct io_kiocb *req)
+{
+ int v;
+
+ /*
+ * poll_refs are already elevated and we don't have much hope for
+ * grabbing the ownership. Instead of incrementing set a retry flag
+ * to notify the loop that there might have been some change.
+ */
+ v = atomic_fetch_or(IO_POLL_RETRY_FLAG, &req->poll_refs);
+ if (v & IO_POLL_REF_MASK)
+ return false;
+ return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK);
+}
+
+/*
+ * If refs part of ->poll_refs (see IO_POLL_REF_MASK) is 0, it's free. We can
+ * bump it and acquire ownership. It's disallowed to modify requests while not
+ * owning it, that prevents from races for enqueueing task_work's and b/w
+ * arming poll and wakeups.
+ */
+static inline bool io_poll_get_ownership(struct io_kiocb *req)
+{
+ if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS))
+ return io_poll_get_ownership_slowpath(req);
+ return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK);
+}
+
+static void io_poll_mark_cancelled(struct io_kiocb *req)
+{
+ atomic_or(IO_POLL_CANCEL_FLAG, &req->poll_refs);
+}
+
+static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req)
+{
+ /* pure poll stashes this in ->async_data, poll driven retry elsewhere */
+ if (req->opcode == IORING_OP_POLL_ADD)
+ return req->async_data;
+ return req->apoll->double_poll;
+}
+
+static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req)
+{
+ if (req->opcode == IORING_OP_POLL_ADD)
+ return &req->poll;
+ return &req->apoll->poll;
+}
+
+static void io_poll_req_insert(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct hlist_head *list;
+
+ list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
+ hlist_add_head(&req->hash_node, list);
+}
+
+static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events,
+ wait_queue_func_t wake_func)
+{
+ poll->head = NULL;
+#define IO_POLL_UNMASK (EPOLLERR|EPOLLHUP|EPOLLNVAL|EPOLLRDHUP)
+ /* mask in events that we always want/need */
+ poll->events = events | IO_POLL_UNMASK;
+ INIT_LIST_HEAD(&poll->wait.entry);
+ init_waitqueue_func_entry(&poll->wait, wake_func);
+}
+
+static inline void io_poll_remove_entry(struct io_poll_iocb *poll)
+{
+ struct wait_queue_head *head = smp_load_acquire(&poll->head);
+
+ if (head) {
+ spin_lock_irq(&head->lock);
+ list_del_init(&poll->wait.entry);
+ poll->head = NULL;
+ spin_unlock_irq(&head->lock);
+ }
+}
+
+static void io_poll_remove_entries(struct io_kiocb *req)
+{
+ struct io_poll_iocb *poll = io_poll_get_single(req);
+ struct io_poll_iocb *poll_double = io_poll_get_double(req);
+
+ /*
+ * While we hold the waitqueue lock and the waitqueue is nonempty,
+ * wake_up_pollfree() will wait for us. However, taking the waitqueue
+ * lock in the first place can race with the waitqueue being freed.
+ *
+ * We solve this as eventpoll does: by taking advantage of the fact that
+ * all users of wake_up_pollfree() will RCU-delay the actual free. If
+ * we enter rcu_read_lock() and see that the pointer to the queue is
+ * non-NULL, we can then lock it without the memory being freed out from
+ * under us.
+ *
+ * Keep holding rcu_read_lock() as long as we hold the queue lock, in
+ * case the caller deletes the entry from the queue, leaving it empty.
+ * In that case, only RCU prevents the queue memory from being freed.
+ */
+ rcu_read_lock();
+ io_poll_remove_entry(poll);
+ if (poll_double)
+ io_poll_remove_entry(poll_double);
+ rcu_read_unlock();
+}
+
+/*
+ * All poll tw should go through this. Checks for poll events, manages
+ * references, does rewait, etc.
+ *
+ * Returns a negative error on failure. >0 when no action require, which is
+ * either spurious wakeup or multishot CQE is served. 0 when it's done with
+ * the request, then the mask is stored in req->result.
+ */
+static int io_poll_check_events(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_poll_iocb *poll = io_poll_get_single(req);
+ int v;
+
+ /* req->task == current here, checking PF_EXITING is safe */
+ if (unlikely(req->task->flags & PF_EXITING))
+ io_poll_mark_cancelled(req);
+
+ do {
+ v = atomic_read(&req->poll_refs);
+
+ /* tw handler should be the owner, and so have some references */
+ if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK)))
+ return 0;
+ if (v & IO_POLL_CANCEL_FLAG)
+ return -ECANCELED;
+ /*
+ * cqe.res contains only events of the first wake up
+ * and all others are be lost. Redo vfs_poll() to get
+ * up to date state.
+ */
+ if ((v & IO_POLL_REF_MASK) != 1)
+ req->result = 0;
+ if (v & IO_POLL_RETRY_FLAG) {
+ req->result = 0;
+ /*
+ * We won't find new events that came in between
+ * vfs_poll and the ref put unless we clear the
+ * flag in advance.
+ */
+ atomic_andnot(IO_POLL_RETRY_FLAG, &req->poll_refs);
+ v &= ~IO_POLL_RETRY_FLAG;
+ }
+
+ if (!req->result) {
+ struct poll_table_struct pt = { ._key = poll->events };
+
+ req->result = vfs_poll(req->file, &pt) & poll->events;
+ }
+
+ /* multishot, just fill an CQE and proceed */
+ if (req->result && !(poll->events & EPOLLONESHOT)) {
+ __poll_t mask = mangle_poll(req->result & poll->events);
+ bool filled;
+
+ spin_lock(&ctx->completion_lock);
+ filled = io_fill_cqe_aux(ctx, req->user_data, mask,
+ IORING_CQE_F_MORE);
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ if (unlikely(!filled))
+ return -ECANCELED;
+ io_cqring_ev_posted(ctx);
+ } else if (req->result) {
+ return 0;
+ }
+
+ /* force the next iteration to vfs_poll() */
+ req->result = 0;
+
+ /*
+ * Release all references, retry if someone tried to restart
+ * task_work while we were executing it.
+ */
+ } while (atomic_sub_return(v & IO_POLL_REF_MASK, &req->poll_refs) &
+ IO_POLL_REF_MASK);
+
+ return 1;
+}
+
+static void io_poll_task_func(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ int ret;
+
+ ret = io_poll_check_events(req);
+ if (ret > 0)
+ return;
+
+ if (!ret) {
+ req->result = mangle_poll(req->result & req->poll.events);
+ } else {
+ req->result = ret;
+ req_set_fail(req);
+ }
+
+ io_poll_remove_entries(req);
+ spin_lock(&ctx->completion_lock);
+ hash_del(&req->hash_node);
+ spin_unlock(&ctx->completion_lock);
+ io_req_complete_post(req, req->result, 0);
+}
+
+static void io_apoll_task_func(struct io_kiocb *req, bool *locked)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ int ret;
+
+ ret = io_poll_check_events(req);
+ if (ret > 0)
+ return;
+
+ io_poll_remove_entries(req);
+ spin_lock(&ctx->completion_lock);
+ hash_del(&req->hash_node);
+ spin_unlock(&ctx->completion_lock);
+
+ if (!ret)
+ io_req_task_submit(req, locked);
+ else
+ io_req_complete_failed(req, ret);
+}
+
+static void __io_poll_execute(struct io_kiocb *req, int mask)
+{
+ req->result = mask;
+ if (req->opcode == IORING_OP_POLL_ADD)
+ req->io_task_work.func = io_poll_task_func;
+ else
+ req->io_task_work.func = io_apoll_task_func;
+
+ trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask);
+ io_req_task_work_add(req);
+}
+
+static inline void io_poll_execute(struct io_kiocb *req, int res)
+{
+ if (io_poll_get_ownership(req))
+ __io_poll_execute(req, res);
+}
+
+static void io_poll_cancel_req(struct io_kiocb *req)
+{
+ io_poll_mark_cancelled(req);
+ /* kick tw, which should complete the request */
+ io_poll_execute(req, 0);
+}
+
+static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
+ void *key)
+{
+ struct io_kiocb *req = wait->private;
+ struct io_poll_iocb *poll = container_of(wait, struct io_poll_iocb,
+ wait);
+ __poll_t mask = key_to_poll(key);
+
+ if (unlikely(mask & POLLFREE)) {
+ io_poll_mark_cancelled(req);
+ /* we have to kick tw in case it's not already */
+ io_poll_execute(req, 0);
+
+ /*
+ * If the waitqueue is being freed early but someone is already
+ * holds ownership over it, we have to tear down the request as
+ * best we can. That means immediately removing the request from
+ * its waitqueue and preventing all further accesses to the
+ * waitqueue via the request.
+ */
+ list_del_init(&poll->wait.entry);
+
+ /*
+ * Careful: this *must* be the last step, since as soon
+ * as req->head is NULL'ed out, the request can be
+ * completed and freed, since aio_poll_complete_work()
+ * will no longer need to take the waitqueue lock.
+ */
+ smp_store_release(&poll->head, NULL);
+ return 1;
+ }
+
+ /* for instances that support it check for an event match first */
+ if (mask && !(mask & poll->events))
+ return 0;
+
+ if (io_poll_get_ownership(req))
+ __io_poll_execute(req, mask);
+ return 1;
+}
+
+static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
+ struct wait_queue_head *head,
+ struct io_poll_iocb **poll_ptr)
+{
+ struct io_kiocb *req = pt->req;
+
+ /*
+ * The file being polled uses multiple waitqueues for poll handling
+ * (e.g. one for read, one for write). Setup a separate io_poll_iocb
+ * if this happens.
+ */
+ if (unlikely(pt->nr_entries)) {
+ struct io_poll_iocb *first = poll;
+
+ /* double add on the same waitqueue head, ignore */
+ if (first->head == head)
+ return;
+ /* already have a 2nd entry, fail a third attempt */
+ if (*poll_ptr) {
+ if ((*poll_ptr)->head == head)
+ return;
+ pt->error = -EINVAL;
+ return;
+ }
+
+ poll = kmalloc(sizeof(*poll), GFP_ATOMIC);
+ if (!poll) {
+ pt->error = -ENOMEM;
+ return;
+ }
+ io_init_poll_iocb(poll, first->events, first->wait.func);
+ *poll_ptr = poll;
+ }
+
+ pt->nr_entries++;
+ poll->head = head;
+ poll->wait.private = req;
+
+ if (poll->events & EPOLLEXCLUSIVE)
+ add_wait_queue_exclusive(head, &poll->wait);
+ else
+ add_wait_queue(head, &poll->wait);
+}
+
+static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
+ struct poll_table_struct *p)
+{
+ struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
+
+ __io_queue_proc(&pt->req->poll, pt, head,
+ (struct io_poll_iocb **) &pt->req->async_data);
+}
+
+static int __io_arm_poll_handler(struct io_kiocb *req,
+ struct io_poll_iocb *poll,
+ struct io_poll_table *ipt, __poll_t mask)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ INIT_HLIST_NODE(&req->hash_node);
+ io_init_poll_iocb(poll, mask, io_poll_wake);
+ poll->file = req->file;
+ poll->wait.private = req;
+
+ ipt->pt._key = mask;
+ ipt->req = req;
+ ipt->error = 0;
+ ipt->nr_entries = 0;
+
+ /*
+ * Take the ownership to delay any tw execution up until we're done
+ * with poll arming. see io_poll_get_ownership().
+ */
+ atomic_set(&req->poll_refs, 1);
+ mask = vfs_poll(req->file, &ipt->pt) & poll->events;
+
+ if (mask && (poll->events & EPOLLONESHOT)) {
+ io_poll_remove_entries(req);
+ /* no one else has access to the req, forget about the ref */
+ return mask;
+ }
+ if (!mask && unlikely(ipt->error || !ipt->nr_entries)) {
+ io_poll_remove_entries(req);
+ if (!ipt->error)
+ ipt->error = -EINVAL;
+ return 0;
+ }
+
+ spin_lock(&ctx->completion_lock);
+ io_poll_req_insert(req);
+ spin_unlock(&ctx->completion_lock);
+
+ if (mask) {
+ /* can't multishot if failed, just queue the event we've got */
+ if (unlikely(ipt->error || !ipt->nr_entries)) {
+ poll->events |= EPOLLONESHOT;
+ ipt->error = 0;
+ }
+ __io_poll_execute(req, mask);
+ return 0;
+ }
+
+ /*
+ * Try to release ownership. If we see a change of state, e.g.
+ * poll was waken up, queue up a tw, it'll deal with it.
+ */
+ if (atomic_cmpxchg(&req->poll_refs, 1, 0) != 1)
+ __io_poll_execute(req, 0);
+ return 0;
+}
+
+static void io_async_queue_proc(struct file *file, struct wait_queue_head *head,
+ struct poll_table_struct *p)
+{
+ struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
+ struct async_poll *apoll = pt->req->apoll;
+
+ __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll);
+}
+
+enum {
+ IO_APOLL_OK,
+ IO_APOLL_ABORTED,
+ IO_APOLL_READY
+};
+
+static int io_arm_poll_handler(struct io_kiocb *req)
+{
+ const struct io_op_def *def = &io_op_defs[req->opcode];
+ struct io_ring_ctx *ctx = req->ctx;
+ struct async_poll *apoll;
+ struct io_poll_table ipt;
+ __poll_t mask = EPOLLONESHOT | POLLERR | POLLPRI;
+ int ret;
+
+ if (!req->file || !file_can_poll(req->file))
+ return IO_APOLL_ABORTED;
+ if (req->flags & REQ_F_POLLED)
+ return IO_APOLL_ABORTED;
+ if (!def->pollin && !def->pollout)
+ return IO_APOLL_ABORTED;
+
+ if (def->pollin) {
+ mask |= POLLIN | POLLRDNORM;
+
+ /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */
+ if ((req->opcode == IORING_OP_RECVMSG) &&
+ (req->sr_msg.msg_flags & MSG_ERRQUEUE))
+ mask &= ~POLLIN;
+ } else {
+ mask |= POLLOUT | POLLWRNORM;
+ }
+
+ apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
+ if (unlikely(!apoll))
+ return IO_APOLL_ABORTED;
+ apoll->double_poll = NULL;
+ req->apoll = apoll;
+ req->flags |= REQ_F_POLLED;
+ ipt.pt._qproc = io_async_queue_proc;
+
+ ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask);
+ if (ret || ipt.error)
+ return ret ? IO_APOLL_READY : IO_APOLL_ABORTED;
+
+ trace_io_uring_poll_arm(ctx, req, req->opcode, req->user_data,
+ mask, apoll->poll.events);
+ return IO_APOLL_OK;
+}
+
+/*
+ * Returns true if we found and killed one or more poll requests
+ */
+static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
+ bool cancel_all)
+{
+ struct hlist_node *tmp;
+ struct io_kiocb *req;
+ bool found = false;
+ int i;
+
+ spin_lock(&ctx->completion_lock);
+ for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
+ struct hlist_head *list;
+
+ list = &ctx->cancel_hash[i];
+ hlist_for_each_entry_safe(req, tmp, list, hash_node) {
+ if (io_match_task_safe(req, tsk, cancel_all)) {
+ hlist_del_init(&req->hash_node);
+ io_poll_cancel_req(req);
+ found = true;
+ }
+ }
+ }
+ spin_unlock(&ctx->completion_lock);
+ return found;
+}
+
+static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, __u64 sqe_addr,
+ bool poll_only)
+ __must_hold(&ctx->completion_lock)
+{
+ struct hlist_head *list;
+ struct io_kiocb *req;
+
+ list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
+ hlist_for_each_entry(req, list, hash_node) {
+ if (sqe_addr != req->user_data)
+ continue;
+ if (poll_only && req->opcode != IORING_OP_POLL_ADD)
+ continue;
+ return req;
+ }
+ return NULL;
+}
+
+static bool io_poll_disarm(struct io_kiocb *req)
+ __must_hold(&ctx->completion_lock)
+{
+ if (!io_poll_get_ownership(req))
+ return false;
+ io_poll_remove_entries(req);
+ hash_del(&req->hash_node);
+ return true;
+}
+
+static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr,
+ bool poll_only)
+ __must_hold(&ctx->completion_lock)
+{
+ struct io_kiocb *req = io_poll_find(ctx, sqe_addr, poll_only);
+
+ if (!req)
+ return -ENOENT;
+ io_poll_cancel_req(req);
+ return 0;
+}
+
+static __poll_t io_poll_parse_events(const struct io_uring_sqe *sqe,
+ unsigned int flags)
+{
+ u32 events;
+
+ events = READ_ONCE(sqe->poll32_events);
+#ifdef __BIG_ENDIAN
+ events = swahw32(events);
+#endif
+ if (!(flags & IORING_POLL_ADD_MULTI))
+ events |= EPOLLONESHOT;
+ return demangle_poll(events) | (events & (EPOLLEXCLUSIVE|EPOLLONESHOT));
+}
+
+static int io_poll_update_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_poll_update *upd = &req->poll_update;
+ u32 flags;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
+ return -EINVAL;
+ flags = READ_ONCE(sqe->len);
+ if (flags & ~(IORING_POLL_UPDATE_EVENTS | IORING_POLL_UPDATE_USER_DATA |
+ IORING_POLL_ADD_MULTI))
+ return -EINVAL;
+ /* meaningless without update */
+ if (flags == IORING_POLL_ADD_MULTI)
+ return -EINVAL;
+
+ upd->old_user_data = READ_ONCE(sqe->addr);
+ upd->update_events = flags & IORING_POLL_UPDATE_EVENTS;
+ upd->update_user_data = flags & IORING_POLL_UPDATE_USER_DATA;
+
+ upd->new_user_data = READ_ONCE(sqe->off);
+ if (!upd->update_user_data && upd->new_user_data)
+ return -EINVAL;
+ if (upd->update_events)
+ upd->events = io_poll_parse_events(sqe, flags);
+ else if (sqe->poll32_events)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_poll_iocb *poll = &req->poll;
+ u32 flags;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->off || sqe->addr)
+ return -EINVAL;
+ flags = READ_ONCE(sqe->len);
+ if (flags & ~IORING_POLL_ADD_MULTI)
+ return -EINVAL;
+
+ io_req_set_refcount(req);
+ poll->events = io_poll_parse_events(sqe, flags);
+ return 0;
+}
+
+static int io_poll_add(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_poll_iocb *poll = &req->poll;
+ struct io_poll_table ipt;
+ int ret;
+
+ ipt.pt._qproc = io_poll_queue_proc;
+
+ ret = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events);
+ if (!ret && ipt.error)
+ req_set_fail(req);
+ ret = ret ?: ipt.error;
+ if (ret)
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_poll_update(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_kiocb *preq;
+ int ret2, ret = 0;
+
+ spin_lock(&ctx->completion_lock);
+ preq = io_poll_find(ctx, req->poll_update.old_user_data, true);
+ if (!preq || !io_poll_disarm(preq)) {
+ spin_unlock(&ctx->completion_lock);
+ ret = preq ? -EALREADY : -ENOENT;
+ goto out;
+ }
+ spin_unlock(&ctx->completion_lock);
+
+ if (req->poll_update.update_events || req->poll_update.update_user_data) {
+ /* only mask one event flags, keep behavior flags */
+ if (req->poll_update.update_events) {
+ preq->poll.events &= ~0xffff;
+ preq->poll.events |= req->poll_update.events & 0xffff;
+ preq->poll.events |= IO_POLL_UNMASK;
+ }
+ if (req->poll_update.update_user_data)
+ preq->user_data = req->poll_update.new_user_data;
+
+ ret2 = io_poll_add(preq, issue_flags);
+ /* successfully updated, don't complete poll request */
+ if (!ret2)
+ goto out;
+ }
+ req_set_fail(preq);
+ io_req_complete(preq, -ECANCELED);
+out:
+ if (ret < 0)
+ req_set_fail(req);
+ /* complete update request, we're done with it */
+ io_req_complete(req, ret);
+ return 0;
+}
+
+static void io_req_task_timeout(struct io_kiocb *req, bool *locked)
+{
+ req_set_fail(req);
+ io_req_complete_post(req, -ETIME, 0);
+}
+
+static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
+{
+ struct io_timeout_data *data = container_of(timer,
+ struct io_timeout_data, timer);
+ struct io_kiocb *req = data->req;
+ struct io_ring_ctx *ctx = req->ctx;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctx->timeout_lock, flags);
+ list_del_init(&req->timeout.list);
+ atomic_set(&req->ctx->cq_timeouts,
+ atomic_read(&req->ctx->cq_timeouts) + 1);
+ spin_unlock_irqrestore(&ctx->timeout_lock, flags);
+
+ req->io_task_work.func = io_req_task_timeout;
+ io_req_task_work_add(req);
+ return HRTIMER_NORESTART;
+}
+
+static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx,
+ __u64 user_data)
+ __must_hold(&ctx->timeout_lock)
+{
+ struct io_timeout_data *io;
+ struct io_kiocb *req;
+ bool found = false;
+
+ list_for_each_entry(req, &ctx->timeout_list, timeout.list) {
+ found = user_data == req->user_data;
+ if (found)
+ break;
+ }
+ if (!found)
+ return ERR_PTR(-ENOENT);
+
+ io = req->async_data;
+ if (hrtimer_try_to_cancel(&io->timer) == -1)
+ return ERR_PTR(-EALREADY);
+ list_del_init(&req->timeout.list);
+ return req;
+}
+
+static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data)
+ __must_hold(&ctx->completion_lock)
+ __must_hold(&ctx->timeout_lock)
+{
+ struct io_kiocb *req = io_timeout_extract(ctx, user_data);
+
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ req_set_fail(req);
+ io_fill_cqe_req(req, -ECANCELED, 0);
+ io_put_req_deferred(req);
+ return 0;
+}
+
+static clockid_t io_timeout_get_clock(struct io_timeout_data *data)
+{
+ switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) {
+ case IORING_TIMEOUT_BOOTTIME:
+ return CLOCK_BOOTTIME;
+ case IORING_TIMEOUT_REALTIME:
+ return CLOCK_REALTIME;
+ default:
+ /* can't happen, vetted at prep time */
+ WARN_ON_ONCE(1);
+ fallthrough;
+ case 0:
+ return CLOCK_MONOTONIC;
+ }
+}
+
+static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
+ struct timespec64 *ts, enum hrtimer_mode mode)
+ __must_hold(&ctx->timeout_lock)
+{
+ struct io_timeout_data *io;
+ struct io_kiocb *req;
+ bool found = false;
+
+ list_for_each_entry(req, &ctx->ltimeout_list, timeout.list) {
+ found = user_data == req->user_data;
+ if (found)
+ break;
+ }
+ if (!found)
+ return -ENOENT;
+
+ io = req->async_data;
+ if (hrtimer_try_to_cancel(&io->timer) == -1)
+ return -EALREADY;
+ hrtimer_init(&io->timer, io_timeout_get_clock(io), mode);
+ io->timer.function = io_link_timeout_fn;
+ hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode);
+ return 0;
+}
+
+static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
+ struct timespec64 *ts, enum hrtimer_mode mode)
+ __must_hold(&ctx->timeout_lock)
+{
+ struct io_kiocb *req = io_timeout_extract(ctx, user_data);
+ struct io_timeout_data *data;
+
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ req->timeout.off = 0; /* noseq */
+ data = req->async_data;
+ list_add_tail(&req->timeout.list, &ctx->timeout_list);
+ hrtimer_init(&data->timer, io_timeout_get_clock(data), mode);
+ data->timer.function = io_timeout_fn;
+ hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode);
+ return 0;
+}
+
+static int io_timeout_remove_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ struct io_timeout_rem *tr = &req->timeout_rem;
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->len || sqe->splice_fd_in)
+ return -EINVAL;
+
+ tr->ltimeout = false;
+ tr->addr = READ_ONCE(sqe->addr);
+ tr->flags = READ_ONCE(sqe->timeout_flags);
+ if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) {
+ if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
+ return -EINVAL;
+ if (tr->flags & IORING_LINK_TIMEOUT_UPDATE)
+ tr->ltimeout = true;
+ if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS))
+ return -EINVAL;
+ if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2)))
+ return -EFAULT;
+ } else if (tr->flags) {
+ /* timeout removal doesn't support flags */
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags)
+{
+ return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS
+ : HRTIMER_MODE_REL;
+}
+
+/*
+ * Remove or update an existing timeout command
+ */
+static int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_timeout_rem *tr = &req->timeout_rem;
+ struct io_ring_ctx *ctx = req->ctx;
+ int ret;
+
+ if (!(req->timeout_rem.flags & IORING_TIMEOUT_UPDATE)) {
+ spin_lock(&ctx->completion_lock);
+ spin_lock_irq(&ctx->timeout_lock);
+ ret = io_timeout_cancel(ctx, tr->addr);
+ spin_unlock_irq(&ctx->timeout_lock);
+ spin_unlock(&ctx->completion_lock);
+ } else {
+ enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags);
+
+ spin_lock_irq(&ctx->timeout_lock);
+ if (tr->ltimeout)
+ ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode);
+ else
+ ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode);
+ spin_unlock_irq(&ctx->timeout_lock);
+ }
+
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete_post(req, ret, 0);
+ return 0;
+}
+
+static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
+ bool is_timeout_link)
+{
+ struct io_timeout_data *data;
+ unsigned flags;
+ u32 off = READ_ONCE(sqe->off);
+
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->buf_index || sqe->len != 1 ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+ if (off && is_timeout_link)
+ return -EINVAL;
+ flags = READ_ONCE(sqe->timeout_flags);
+ if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK))
+ return -EINVAL;
+ /* more than one clock specified is invalid, obviously */
+ if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
+ return -EINVAL;
+
+ INIT_LIST_HEAD(&req->timeout.list);
+ req->timeout.off = off;
+ if (unlikely(off && !req->ctx->off_timeout_used))
+ req->ctx->off_timeout_used = true;
+
+ if (!req->async_data && io_alloc_async_data(req))
+ return -ENOMEM;
+
+ data = req->async_data;
+ data->req = req;
+ data->flags = flags;
+
+ if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
+ return -EFAULT;
+
+ INIT_LIST_HEAD(&req->timeout.list);
+ data->mode = io_translate_timeout_mode(flags);
+ hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode);
+
+ if (is_timeout_link) {
+ struct io_submit_link *link = &req->ctx->submit_state.link;
+
+ if (!link->head)
+ return -EINVAL;
+ if (link->last->opcode == IORING_OP_LINK_TIMEOUT)
+ return -EINVAL;
+ req->timeout.head = link->last;
+ link->last->flags |= REQ_F_ARM_LTIMEOUT;
+ }
+ return 0;
+}
+
+static int io_timeout(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_timeout_data *data = req->async_data;
+ struct list_head *entry;
+ u32 tail, off = req->timeout.off;
+
+ spin_lock_irq(&ctx->timeout_lock);
+
+ /*
+ * sqe->off holds how many events that need to occur for this
+ * timeout event to be satisfied. If it isn't set, then this is
+ * a pure timeout request, sequence isn't used.
+ */
+ if (io_is_timeout_noseq(req)) {
+ entry = ctx->timeout_list.prev;
+ goto add;
+ }
+
+ tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
+ req->timeout.target_seq = tail + off;
+
+ /* Update the last seq here in case io_flush_timeouts() hasn't.
+ * This is safe because ->completion_lock is held, and submissions
+ * and completions are never mixed in the same ->completion_lock section.
+ */
+ ctx->cq_last_tm_flush = tail;
+
+ /*
+ * Insertion sort, ensuring the first entry in the list is always
+ * the one we need first.
+ */
+ list_for_each_prev(entry, &ctx->timeout_list) {
+ struct io_kiocb *nxt = list_entry(entry, struct io_kiocb,
+ timeout.list);
+
+ if (io_is_timeout_noseq(nxt))
+ continue;
+ /* nxt.seq is behind @tail, otherwise would've been completed */
+ if (off >= nxt->timeout.target_seq - tail)
+ break;
+ }
+add:
+ list_add(&req->timeout.list, entry);
+ data->timer.function = io_timeout_fn;
+ hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
+ spin_unlock_irq(&ctx->timeout_lock);
+ return 0;
+}
+
+struct io_cancel_data {
+ struct io_ring_ctx *ctx;
+ u64 user_data;
+};
+
+static bool io_cancel_cb(struct io_wq_work *work, void *data)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+ struct io_cancel_data *cd = data;
+
+ return req->ctx == cd->ctx && req->user_data == cd->user_data;
+}
+
+static int io_async_cancel_one(struct io_uring_task *tctx, u64 user_data,
+ struct io_ring_ctx *ctx)
+{
+ struct io_cancel_data data = { .ctx = ctx, .user_data = user_data, };
+ enum io_wq_cancel cancel_ret;
+ int ret = 0;
+
+ if (!tctx || !tctx->io_wq)
+ return -ENOENT;
+
+ cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, &data, false);
+ switch (cancel_ret) {
+ case IO_WQ_CANCEL_OK:
+ ret = 0;
+ break;
+ case IO_WQ_CANCEL_RUNNING:
+ ret = -EALREADY;
+ break;
+ case IO_WQ_CANCEL_NOTFOUND:
+ ret = -ENOENT;
+ break;
+ }
+
+ return ret;
+}
+
+static int io_try_cancel_userdata(struct io_kiocb *req, u64 sqe_addr)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ int ret;
+
+ WARN_ON_ONCE(!io_wq_current_is_worker() && req->task != current);
+
+ ret = io_async_cancel_one(req->task->io_uring, sqe_addr, ctx);
+ if (ret != -ENOENT)
+ return ret;
+
+ spin_lock(&ctx->completion_lock);
+ spin_lock_irq(&ctx->timeout_lock);
+ ret = io_timeout_cancel(ctx, sqe_addr);
+ spin_unlock_irq(&ctx->timeout_lock);
+ if (ret != -ENOENT)
+ goto out;
+ ret = io_poll_cancel(ctx, sqe_addr, false);
+out:
+ spin_unlock(&ctx->completion_lock);
+ return ret;
+}
+
+static int io_async_cancel_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags ||
+ sqe->splice_fd_in)
+ return -EINVAL;
+
+ req->cancel.addr = READ_ONCE(sqe->addr);
+ return 0;
+}
+
+static int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ u64 sqe_addr = req->cancel.addr;
+ struct io_tctx_node *node;
+ int ret;
+
+ ret = io_try_cancel_userdata(req, sqe_addr);
+ if (ret != -ENOENT)
+ goto done;
+
+ /* slow path, try all io-wq's */
+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+ ret = -ENOENT;
+ list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
+ struct io_uring_task *tctx = node->task->io_uring;
+
+ ret = io_async_cancel_one(tctx, req->cancel.addr, ctx);
+ if (ret != -ENOENT)
+ break;
+ }
+ io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+done:
+ if (ret < 0)
+ req_set_fail(req);
+ io_req_complete_post(req, ret, 0);
+ return 0;
+}
+
+static int io_rsrc_update_prep(struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+{
+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->rw_flags || sqe->splice_fd_in)
+ return -EINVAL;
+
+ req->rsrc_update.offset = READ_ONCE(sqe->off);
+ req->rsrc_update.nr_args = READ_ONCE(sqe->len);
+ if (!req->rsrc_update.nr_args)
+ return -EINVAL;
+ req->rsrc_update.arg = READ_ONCE(sqe->addr);
+ return 0;
+}
+
+static int io_files_update(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_uring_rsrc_update2 up;
+ int ret;
+
+ up.offset = req->rsrc_update.offset;
+ up.data = req->rsrc_update.arg;
+ up.nr = 0;
+ up.tags = 0;
+ up.resv = 0;
+ up.resv2 = 0;
+
+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+ ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE,
+ &up, req->rsrc_update.nr_args);
+ io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+
+ if (ret < 0)
+ req_set_fail(req);
+ __io_req_complete(req, issue_flags, ret, 0);
+ return 0;
+}
+
+static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ switch (req->opcode) {
+ case IORING_OP_NOP:
+ return 0;
+ case IORING_OP_READV:
+ case IORING_OP_READ_FIXED:
+ case IORING_OP_READ:
+ return io_read_prep(req, sqe);
+ case IORING_OP_WRITEV:
+ case IORING_OP_WRITE_FIXED:
+ case IORING_OP_WRITE:
+ return io_write_prep(req, sqe);
+ case IORING_OP_POLL_ADD:
+ return io_poll_add_prep(req, sqe);
+ case IORING_OP_POLL_REMOVE:
+ return io_poll_update_prep(req, sqe);
+ case IORING_OP_FSYNC:
+ return io_fsync_prep(req, sqe);
+ case IORING_OP_SYNC_FILE_RANGE:
+ return io_sfr_prep(req, sqe);
+ case IORING_OP_SENDMSG:
+ case IORING_OP_SEND:
+ return io_sendmsg_prep(req, sqe);
+ case IORING_OP_RECVMSG:
+ case IORING_OP_RECV:
+ return io_recvmsg_prep(req, sqe);
+ case IORING_OP_CONNECT:
+ return io_connect_prep(req, sqe);
+ case IORING_OP_TIMEOUT:
+ return io_timeout_prep(req, sqe, false);
+ case IORING_OP_TIMEOUT_REMOVE:
+ return io_timeout_remove_prep(req, sqe);
+ case IORING_OP_ASYNC_CANCEL:
+ return io_async_cancel_prep(req, sqe);
+ case IORING_OP_LINK_TIMEOUT:
+ return io_timeout_prep(req, sqe, true);
+ case IORING_OP_ACCEPT:
+ return io_accept_prep(req, sqe);
+ case IORING_OP_FALLOCATE:
+ return io_fallocate_prep(req, sqe);
+ case IORING_OP_OPENAT:
+ return io_openat_prep(req, sqe);
+ case IORING_OP_CLOSE:
+ return io_close_prep(req, sqe);
+ case IORING_OP_FILES_UPDATE:
+ return io_rsrc_update_prep(req, sqe);
+ case IORING_OP_STATX:
+ return io_statx_prep(req, sqe);
+ case IORING_OP_FADVISE:
+ return io_fadvise_prep(req, sqe);
+ case IORING_OP_MADVISE:
+ return io_madvise_prep(req, sqe);
+ case IORING_OP_OPENAT2:
+ return io_openat2_prep(req, sqe);
+ case IORING_OP_EPOLL_CTL:
+ return io_epoll_ctl_prep(req, sqe);
+ case IORING_OP_SPLICE:
+ return io_splice_prep(req, sqe);
+ case IORING_OP_PROVIDE_BUFFERS:
+ return io_provide_buffers_prep(req, sqe);
+ case IORING_OP_REMOVE_BUFFERS:
+ return io_remove_buffers_prep(req, sqe);
+ case IORING_OP_TEE:
+ return io_tee_prep(req, sqe);
+ case IORING_OP_SHUTDOWN:
+ return io_shutdown_prep(req, sqe);
+ case IORING_OP_RENAMEAT:
+ return io_renameat_prep(req, sqe);
+ case IORING_OP_UNLINKAT:
+ return io_unlinkat_prep(req, sqe);
+ }
+
+ printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
+ req->opcode);
+ return -EINVAL;
+}
+
+static int io_req_prep_async(struct io_kiocb *req)
+{
+ if (!io_op_defs[req->opcode].needs_async_setup)
+ return 0;
+ if (WARN_ON_ONCE(req->async_data))
+ return -EFAULT;
+ if (io_alloc_async_data(req))
+ return -EAGAIN;
+
+ switch (req->opcode) {
+ case IORING_OP_READV:
+ return io_rw_prep_async(req, READ);
+ case IORING_OP_WRITEV:
+ return io_rw_prep_async(req, WRITE);
+ case IORING_OP_SENDMSG:
+ return io_sendmsg_prep_async(req);
+ case IORING_OP_RECVMSG:
+ return io_recvmsg_prep_async(req);
+ case IORING_OP_CONNECT:
+ return io_connect_prep_async(req);
+ }
+ printk_once(KERN_WARNING "io_uring: prep_async() bad opcode %d\n",
+ req->opcode);
+ return -EFAULT;
+}
+
+static u32 io_get_sequence(struct io_kiocb *req)
+{
+ u32 seq = req->ctx->cached_sq_head;
+
+ /* need original cached_sq_head, but it was increased for each req */
+ io_for_each_link(req, req)
+ seq--;
+ return seq;
+}
+
+static bool io_drain_req(struct io_kiocb *req)
+{
+ struct io_kiocb *pos;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_defer_entry *de;
+ int ret;
+ u32 seq;
+
+ if (req->flags & REQ_F_FAIL) {
+ io_req_complete_fail_submit(req);
+ return true;
+ }
+
+ /*
+ * If we need to drain a request in the middle of a link, drain the
+ * head request and the next request/link after the current link.
+ * Considering sequential execution of links, IOSQE_IO_DRAIN will be
+ * maintained for every request of our link.
+ */
+ if (ctx->drain_next) {
+ req->flags |= REQ_F_IO_DRAIN;
+ ctx->drain_next = false;
+ }
+ /* not interested in head, start from the first linked */
+ io_for_each_link(pos, req->link) {
+ if (pos->flags & REQ_F_IO_DRAIN) {
+ ctx->drain_next = true;
+ req->flags |= REQ_F_IO_DRAIN;
+ break;
+ }
+ }
+
+ /* Still need defer if there is pending req in defer list. */
+ spin_lock(&ctx->completion_lock);
+ if (likely(list_empty_careful(&ctx->defer_list) &&
+ !(req->flags & REQ_F_IO_DRAIN))) {
+ spin_unlock(&ctx->completion_lock);
+ ctx->drain_active = false;
+ return false;
+ }
+ spin_unlock(&ctx->completion_lock);
+
+ seq = io_get_sequence(req);
+ /* Still a chance to pass the sequence check */
+ if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list))
+ return false;
+
+ ret = io_req_prep_async(req);
+ if (ret)
+ goto fail;
+ io_prep_async_link(req);
+ de = kmalloc(sizeof(*de), GFP_KERNEL);
+ if (!de) {
+ ret = -ENOMEM;
+fail:
+ io_req_complete_failed(req, ret);
+ return true;
+ }
+
+ spin_lock(&ctx->completion_lock);
+ if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
+ spin_unlock(&ctx->completion_lock);
+ kfree(de);
+ io_queue_async_work(req, NULL);
+ return true;
+ }
+
+ trace_io_uring_defer(ctx, req, req->user_data);
+ de->req = req;
+ de->seq = seq;
+ list_add_tail(&de->list, &ctx->defer_list);
+ spin_unlock(&ctx->completion_lock);
+ return true;
+}
+
+static void io_clean_op(struct io_kiocb *req)
+{
+ if (req->flags & REQ_F_BUFFER_SELECTED) {
+ switch (req->opcode) {
+ case IORING_OP_READV:
+ case IORING_OP_READ_FIXED:
+ case IORING_OP_READ:
+ kfree((void *)(unsigned long)req->rw.addr);
+ break;
+ case IORING_OP_RECVMSG:
+ case IORING_OP_RECV:
+ kfree(req->sr_msg.kbuf);
+ break;
+ }
+ }
+
+ if (req->flags & REQ_F_NEED_CLEANUP) {
+ switch (req->opcode) {
+ case IORING_OP_READV:
+ case IORING_OP_READ_FIXED:
+ case IORING_OP_READ:
+ case IORING_OP_WRITEV:
+ case IORING_OP_WRITE_FIXED:
+ case IORING_OP_WRITE: {
+ struct io_async_rw *io = req->async_data;
+
+ kfree(io->free_iovec);
+ break;
+ }
+ case IORING_OP_RECVMSG:
+ case IORING_OP_SENDMSG: {
+ struct io_async_msghdr *io = req->async_data;
+
+ kfree(io->free_iov);
+ break;
+ }
+ case IORING_OP_OPENAT:
+ case IORING_OP_OPENAT2:
+ if (req->open.filename)
+ putname(req->open.filename);
+ break;
+ case IORING_OP_RENAMEAT:
+ putname(req->rename.oldpath);
+ putname(req->rename.newpath);
+ break;
+ case IORING_OP_UNLINKAT:
+ putname(req->unlink.filename);
+ break;
+ }
+ }
+ if ((req->flags & REQ_F_POLLED) && req->apoll) {
+ kfree(req->apoll->double_poll);
+ kfree(req->apoll);
+ req->apoll = NULL;
+ }
+ if (req->flags & REQ_F_INFLIGHT) {
+ struct io_uring_task *tctx = req->task->io_uring;
+
+ atomic_dec(&tctx->inflight_tracked);
+ }
+ if (req->flags & REQ_F_CREDS)
+ put_cred(req->creds);
+
+ req->flags &= ~IO_REQ_CLEAN_FLAGS;
+}
+
+static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ const struct cred *creds = NULL;
+ int ret;
+
+ if ((req->flags & REQ_F_CREDS) && req->creds != current_cred())
+ creds = override_creds(req->creds);
+
+ switch (req->opcode) {
+ case IORING_OP_NOP:
+ ret = io_nop(req, issue_flags);
+ break;
+ case IORING_OP_READV:
+ case IORING_OP_READ_FIXED:
+ case IORING_OP_READ:
+ ret = io_read(req, issue_flags);
+ break;
+ case IORING_OP_WRITEV:
+ case IORING_OP_WRITE_FIXED:
+ case IORING_OP_WRITE:
+ ret = io_write(req, issue_flags);
+ break;
+ case IORING_OP_FSYNC:
+ ret = io_fsync(req, issue_flags);
+ break;
+ case IORING_OP_POLL_ADD:
+ ret = io_poll_add(req, issue_flags);
+ break;
+ case IORING_OP_POLL_REMOVE:
+ ret = io_poll_update(req, issue_flags);
+ break;
+ case IORING_OP_SYNC_FILE_RANGE:
+ ret = io_sync_file_range(req, issue_flags);
+ break;
+ case IORING_OP_SENDMSG:
+ ret = io_sendmsg(req, issue_flags);
+ break;
+ case IORING_OP_SEND:
+ ret = io_send(req, issue_flags);
+ break;
+ case IORING_OP_RECVMSG:
+ ret = io_recvmsg(req, issue_flags);
+ break;
+ case IORING_OP_RECV:
+ ret = io_recv(req, issue_flags);
+ break;
+ case IORING_OP_TIMEOUT:
+ ret = io_timeout(req, issue_flags);
+ break;
+ case IORING_OP_TIMEOUT_REMOVE:
+ ret = io_timeout_remove(req, issue_flags);
+ break;
+ case IORING_OP_ACCEPT:
+ ret = io_accept(req, issue_flags);
+ break;
+ case IORING_OP_CONNECT:
+ ret = io_connect(req, issue_flags);
+ break;
+ case IORING_OP_ASYNC_CANCEL:
+ ret = io_async_cancel(req, issue_flags);
+ break;
+ case IORING_OP_FALLOCATE:
+ ret = io_fallocate(req, issue_flags);
+ break;
+ case IORING_OP_OPENAT:
+ ret = io_openat(req, issue_flags);
+ break;
+ case IORING_OP_CLOSE:
+ ret = io_close(req, issue_flags);
+ break;
+ case IORING_OP_FILES_UPDATE:
+ ret = io_files_update(req, issue_flags);
+ break;
+ case IORING_OP_STATX:
+ ret = io_statx(req, issue_flags);
+ break;
+ case IORING_OP_FADVISE:
+ ret = io_fadvise(req, issue_flags);
+ break;
+ case IORING_OP_MADVISE:
+ ret = io_madvise(req, issue_flags);
+ break;
+ case IORING_OP_OPENAT2:
+ ret = io_openat2(req, issue_flags);
+ break;
+ case IORING_OP_EPOLL_CTL:
+ ret = io_epoll_ctl(req, issue_flags);
+ break;
+ case IORING_OP_SPLICE:
+ ret = io_splice(req, issue_flags);
+ break;
+ case IORING_OP_PROVIDE_BUFFERS:
+ ret = io_provide_buffers(req, issue_flags);
+ break;
+ case IORING_OP_REMOVE_BUFFERS:
+ ret = io_remove_buffers(req, issue_flags);
+ break;
+ case IORING_OP_TEE:
+ ret = io_tee(req, issue_flags);
+ break;
+ case IORING_OP_SHUTDOWN:
+ ret = io_shutdown(req, issue_flags);
+ break;
+ case IORING_OP_RENAMEAT:
+ ret = io_renameat(req, issue_flags);
+ break;
+ case IORING_OP_UNLINKAT:
+ ret = io_unlinkat(req, issue_flags);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ if (creds)
+ revert_creds(creds);
+ if (ret)
+ return ret;
+ /* If the op doesn't have a file, we're not polling for it */
+ if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file)
+ io_iopoll_req_issued(req);
+
+ return 0;
+}
+
+static struct io_wq_work *io_wq_free_work(struct io_wq_work *work)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+
+ req = io_put_req_find_next(req);
+ return req ? &req->work : NULL;
+}
+
+static void io_wq_submit_work(struct io_wq_work *work)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+ struct io_kiocb *timeout;
+ int ret = 0;
+
+ /* one will be dropped by ->io_free_work() after returning to io-wq */
+ if (!(req->flags & REQ_F_REFCOUNT))
+ __io_req_set_refcount(req, 2);
+ else
+ req_ref_get(req);
+
+ timeout = io_prep_linked_timeout(req);
+ if (timeout)
+ io_queue_linked_timeout(timeout);
+
+ /* either cancelled or io-wq is dying, so don't touch tctx->iowq */
+ if (work->flags & IO_WQ_WORK_CANCEL)
+ ret = -ECANCELED;
+
+ if (!ret) {
+ do {
+ ret = io_issue_sqe(req, 0);
+ /*
+ * We can get EAGAIN for polled IO even though we're
+ * forcing a sync submission from here, since we can't
+ * wait for request slots on the block side.
+ */
+ if (ret != -EAGAIN || !(req->ctx->flags & IORING_SETUP_IOPOLL))
+ break;
+ cond_resched();
+ } while (1);
+ }
+
+ /* avoid locking problems by failing it from a clean context */
+ if (ret)
+ io_req_task_queue_fail(req, ret);
+}
+
+static inline struct io_fixed_file *io_fixed_file_slot(struct io_file_table *table,
+ unsigned i)
+{
+ return &table->files[i];
+}
+
+static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
+ int index)
+{
+ struct io_fixed_file *slot = io_fixed_file_slot(&ctx->file_table, index);
+
+ return (struct file *) (slot->file_ptr & FFS_MASK);
+}
+
+static void io_fixed_file_set(struct io_fixed_file *file_slot, struct file *file)
+{
+ unsigned long file_ptr = (unsigned long) file;
+
+ if (__io_file_supports_nowait(file, READ))
+ file_ptr |= FFS_ASYNC_READ;
+ if (__io_file_supports_nowait(file, WRITE))
+ file_ptr |= FFS_ASYNC_WRITE;
+ if (S_ISREG(file_inode(file)->i_mode))
+ file_ptr |= FFS_ISREG;
+ file_slot->file_ptr = file_ptr;
+}
+
+static inline struct file *io_file_get_fixed(struct io_ring_ctx *ctx,
+ struct io_kiocb *req, int fd)
+{
+ struct file *file;
+ unsigned long file_ptr;
+
+ if (unlikely((unsigned int)fd >= ctx->nr_user_files))
+ return NULL;
+ fd = array_index_nospec(fd, ctx->nr_user_files);
+ file_ptr = io_fixed_file_slot(&ctx->file_table, fd)->file_ptr;
+ file = (struct file *) (file_ptr & FFS_MASK);
+ file_ptr &= ~FFS_MASK;
+ /* mask in overlapping REQ_F and FFS bits */
+ req->flags |= (file_ptr << REQ_F_NOWAIT_READ_BIT);
+ io_req_set_rsrc_node(req);
+ return file;
+}
+
+static struct file *io_file_get_normal(struct io_ring_ctx *ctx,
+ struct io_kiocb *req, int fd)
+{
+ struct file *file = fget(fd);
+
+ trace_io_uring_file_get(ctx, fd);
+
+ /* we don't allow fixed io_uring files */
+ if (file && unlikely(file->f_op == &io_uring_fops))
+ io_req_track_inflight(req);
+ return file;
+}
+
+static inline struct file *io_file_get(struct io_ring_ctx *ctx,
+ struct io_kiocb *req, int fd, bool fixed)
+{
+ if (fixed)
+ return io_file_get_fixed(ctx, req, fd);
+ else
+ return io_file_get_normal(ctx, req, fd);
+}
+
+static void io_req_task_link_timeout(struct io_kiocb *req, bool *locked)
+{
+ struct io_kiocb *prev = req->timeout.prev;
+ int ret = -ENOENT;
+
+ if (prev) {
+ if (!(req->task->flags & PF_EXITING))
+ ret = io_try_cancel_userdata(req, prev->user_data);
+ io_req_complete_post(req, ret ?: -ETIME, 0);
+ io_put_req(prev);
+ } else {
+ io_req_complete_post(req, -ETIME, 0);
+ }
+}
+
+static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
+{
+ struct io_timeout_data *data = container_of(timer,
+ struct io_timeout_data, timer);
+ struct io_kiocb *prev, *req = data->req;
+ struct io_ring_ctx *ctx = req->ctx;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctx->timeout_lock, flags);
+ prev = req->timeout.head;
+ req->timeout.head = NULL;
+
+ /*
+ * We don't expect the list to be empty, that will only happen if we
+ * race with the completion of the linked work.
+ */
+ if (prev) {
+ io_remove_next_linked(prev);
+ if (!req_ref_inc_not_zero(prev))
+ prev = NULL;
+ }
+ list_del(&req->timeout.list);
+ req->timeout.prev = prev;
+ spin_unlock_irqrestore(&ctx->timeout_lock, flags);
+
+ req->io_task_work.func = io_req_task_link_timeout;
+ io_req_task_work_add(req);
+ return HRTIMER_NORESTART;
+}
+
+static void io_queue_linked_timeout(struct io_kiocb *req)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+
+ spin_lock_irq(&ctx->timeout_lock);
+ /*
+ * If the back reference is NULL, then our linked request finished
+ * before we got a chance to setup the timer
+ */
+ if (req->timeout.head) {
+ struct io_timeout_data *data = req->async_data;
+
+ data->timer.function = io_link_timeout_fn;
+ hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
+ data->mode);
+ list_add_tail(&req->timeout.list, &ctx->ltimeout_list);
+ }
+ spin_unlock_irq(&ctx->timeout_lock);
+ /* drop submission reference */
+ io_put_req(req);
+}
+
+static void __io_queue_sqe(struct io_kiocb *req)
+ __must_hold(&req->ctx->uring_lock)
+{
+ struct io_kiocb *linked_timeout;
+ int ret;
+
+issue_sqe:
+ ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER);
+
+ /*
+ * We async punt it if the file wasn't marked NOWAIT, or if the file
+ * doesn't support non-blocking read/write attempts
+ */
+ if (likely(!ret)) {
+ if (req->flags & REQ_F_COMPLETE_INLINE) {
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_submit_state *state = &ctx->submit_state;
+
+ state->compl_reqs[state->compl_nr++] = req;
+ if (state->compl_nr == ARRAY_SIZE(state->compl_reqs))
+ io_submit_flush_completions(ctx);
+ return;
+ }
+
+ linked_timeout = io_prep_linked_timeout(req);
+ if (linked_timeout)
+ io_queue_linked_timeout(linked_timeout);
+ } else if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
+ linked_timeout = io_prep_linked_timeout(req);
+
+ switch (io_arm_poll_handler(req)) {
+ case IO_APOLL_READY:
+ if (linked_timeout)
+ io_queue_linked_timeout(linked_timeout);
+ goto issue_sqe;
+ case IO_APOLL_ABORTED:
+ /*
+ * Queued up for async execution, worker will release
+ * submit reference when the iocb is actually submitted.
+ */
+ io_queue_async_work(req, NULL);
+ break;
+ }
+
+ if (linked_timeout)
+ io_queue_linked_timeout(linked_timeout);
+ } else {
+ io_req_complete_failed(req, ret);
+ }
+}
+
+static inline void io_queue_sqe(struct io_kiocb *req)
+ __must_hold(&req->ctx->uring_lock)
+{
+ if (unlikely(req->ctx->drain_active) && io_drain_req(req))
+ return;
+
+ if (likely(!(req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL)))) {
+ __io_queue_sqe(req);
+ } else if (req->flags & REQ_F_FAIL) {
+ io_req_complete_fail_submit(req);
+ } else {
+ int ret = io_req_prep_async(req);
+
+ if (unlikely(ret))
+ io_req_complete_failed(req, ret);
+ else
+ io_queue_async_work(req, NULL);
+ }
+}
+
+/*
+ * Check SQE restrictions (opcode and flags).
+ *
+ * Returns 'true' if SQE is allowed, 'false' otherwise.
+ */
+static inline bool io_check_restriction(struct io_ring_ctx *ctx,
+ struct io_kiocb *req,
+ unsigned int sqe_flags)
+{
+ if (likely(!ctx->restricted))
+ return true;
+
+ if (!test_bit(req->opcode, ctx->restrictions.sqe_op))
+ return false;
+
+ if ((sqe_flags & ctx->restrictions.sqe_flags_required) !=
+ ctx->restrictions.sqe_flags_required)
+ return false;
+
+ if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed |
+ ctx->restrictions.sqe_flags_required))
+ return false;
+
+ return true;
+}
+
+static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_submit_state *state;
+ unsigned int sqe_flags;
+ int personality, ret = 0;
+
+ /* req is partially pre-initialised, see io_preinit_req() */
+ req->opcode = READ_ONCE(sqe->opcode);
+ /* same numerical values with corresponding REQ_F_*, safe to copy */
+ req->flags = sqe_flags = READ_ONCE(sqe->flags);
+ req->user_data = READ_ONCE(sqe->user_data);
+ req->file = NULL;
+ req->fixed_rsrc_refs = NULL;
+ req->task = current;
+
+ /* enforce forwards compatibility on users */
+ if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
+ return -EINVAL;
+ if (unlikely(req->opcode >= IORING_OP_LAST))
+ return -EINVAL;
+ if (!io_check_restriction(ctx, req, sqe_flags))
+ return -EACCES;
+
+ if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
+ !io_op_defs[req->opcode].buffer_select)
+ return -EOPNOTSUPP;
+ if (unlikely(sqe_flags & IOSQE_IO_DRAIN))
+ ctx->drain_active = true;
+
+ personality = READ_ONCE(sqe->personality);
+ if (personality) {
+ req->creds = xa_load(&ctx->personalities, personality);
+ if (!req->creds)
+ return -EINVAL;
+ get_cred(req->creds);
+ req->flags |= REQ_F_CREDS;
+ }
+ state = &ctx->submit_state;
+
+ /*
+ * Plug now if we have more than 1 IO left after this, and the target
+ * is potentially a read/write to block based storage.
+ */
+ if (!state->plug_started && state->ios_left > 1 &&
+ io_op_defs[req->opcode].plug) {
+ blk_start_plug(&state->plug);
+ state->plug_started = true;
+ }
+
+ if (io_op_defs[req->opcode].needs_file) {
+ req->file = io_file_get(ctx, req, READ_ONCE(sqe->fd),
+ (sqe_flags & IOSQE_FIXED_FILE));
+ if (unlikely(!req->file))
+ ret = -EBADF;
+ }
+
+ state->ios_left--;
+ return ret;
+}
+
+static int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
+ const struct io_uring_sqe *sqe)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_submit_link *link = &ctx->submit_state.link;
+ int ret;
+
+ ret = io_init_req(ctx, req, sqe);
+ if (unlikely(ret)) {
+fail_req:
+ /* fail even hard links since we don't submit */
+ if (link->head) {
+ /*
+ * we can judge a link req is failed or cancelled by if
+ * REQ_F_FAIL is set, but the head is an exception since
+ * it may be set REQ_F_FAIL because of other req's failure
+ * so let's leverage req->result to distinguish if a head
+ * is set REQ_F_FAIL because of its failure or other req's
+ * failure so that we can set the correct ret code for it.
+ * init result here to avoid affecting the normal path.
+ */
+ if (!(link->head->flags & REQ_F_FAIL))
+ req_fail_link_node(link->head, -ECANCELED);
+ } else if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
+ /*
+ * the current req is a normal req, we should return
+ * error and thus break the submittion loop.
+ */
+ io_req_complete_failed(req, ret);
+ return ret;
+ }
+ req_fail_link_node(req, ret);
+ } else {
+ ret = io_req_prep(req, sqe);
+ if (unlikely(ret))
+ goto fail_req;
+ }
+
+ /* don't need @sqe from now on */
+ trace_io_uring_submit_sqe(ctx, req, req->opcode, req->user_data,
+ req->flags, true,
+ ctx->flags & IORING_SETUP_SQPOLL);
+
+ /*
+ * If we already have a head request, queue this one for async
+ * submittal once the head completes. If we don't have a head but
+ * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
+ * submitted sync once the chain is complete. If none of those
+ * conditions are true (normal request), then just queue it.
+ */
+ if (link->head) {
+ struct io_kiocb *head = link->head;
+
+ if (!(req->flags & REQ_F_FAIL)) {
+ ret = io_req_prep_async(req);
+ if (unlikely(ret)) {
+ req_fail_link_node(req, ret);
+ if (!(head->flags & REQ_F_FAIL))
+ req_fail_link_node(head, -ECANCELED);
+ }
+ }
+ trace_io_uring_link(ctx, req, head);
+ link->last->link = req;
+ link->last = req;
+
+ /* last request of a link, enqueue the link */
+ if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
+ link->head = NULL;
+ io_queue_sqe(head);
+ }
+ } else {
+ if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
+ link->head = req;
+ link->last = req;
+ } else {
+ io_queue_sqe(req);
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Batched submission is done, ensure local IO is flushed out.
+ */
+static void io_submit_state_end(struct io_submit_state *state,
+ struct io_ring_ctx *ctx)
+{
+ if (state->link.head)
+ io_queue_sqe(state->link.head);
+ if (state->compl_nr)
+ io_submit_flush_completions(ctx);
+ if (state->plug_started)
+ blk_finish_plug(&state->plug);
+}
+
+/*
+ * Start submission side cache.
+ */
+static void io_submit_state_start(struct io_submit_state *state,
+ unsigned int max_ios)
+{
+ state->plug_started = false;
+ state->ios_left = max_ios;
+ /* set only head, no need to init link_last in advance */
+ state->link.head = NULL;
+}
+
+static void io_commit_sqring(struct io_ring_ctx *ctx)
+{
+ struct io_rings *rings = ctx->rings;
+
+ /*
+ * Ensure any loads from the SQEs are done at this point,
+ * since once we write the new head, the application could
+ * write new data to them.
+ */
+ smp_store_release(&rings->sq.head, ctx->cached_sq_head);
+}
+
+/*
+ * Fetch an sqe, if one is available. Note this returns a pointer to memory
+ * that is mapped by userspace. This means that care needs to be taken to
+ * ensure that reads are stable, as we cannot rely on userspace always
+ * being a good citizen. If members of the sqe are validated and then later
+ * used, it's important that those reads are done through READ_ONCE() to
+ * prevent a re-load down the line.
+ */
+static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
+{
+ unsigned head, mask = ctx->sq_entries - 1;
+ unsigned sq_idx = ctx->cached_sq_head++ & mask;
+
+ /*
+ * The cached sq head (or cq tail) serves two purposes:
+ *
+ * 1) allows us to batch the cost of updating the user visible
+ * head updates.
+ * 2) allows the kernel side to track the head on its own, even
+ * though the application is the one updating it.
+ */
+ head = READ_ONCE(ctx->sq_array[sq_idx]);
+ if (likely(head < ctx->sq_entries))
+ return &ctx->sq_sqes[head];
+
+ /* drop invalid entries */
+ ctx->cq_extra--;
+ WRITE_ONCE(ctx->rings->sq_dropped,
+ READ_ONCE(ctx->rings->sq_dropped) + 1);
+ return NULL;
+}
+
+static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
+ __must_hold(&ctx->uring_lock)
+{
+ int submitted = 0;
+
+ /* make sure SQ entry isn't read before tail */
+ nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
+ if (!percpu_ref_tryget_many(&ctx->refs, nr))
+ return -EAGAIN;
+ io_get_task_refs(nr);
+
+ io_submit_state_start(&ctx->submit_state, nr);
+ while (submitted < nr) {
+ const struct io_uring_sqe *sqe;
+ struct io_kiocb *req;
+
+ req = io_alloc_req(ctx);
+ if (unlikely(!req)) {
+ if (!submitted)
+ submitted = -EAGAIN;
+ break;
+ }
+ sqe = io_get_sqe(ctx);
+ if (unlikely(!sqe)) {
+ list_add(&req->inflight_entry, &ctx->submit_state.free_list);
+ break;
+ }
+ /* will complete beyond this point, count as submitted */
+ submitted++;
+ if (io_submit_sqe(ctx, req, sqe))
+ break;
+ }
+
+ if (unlikely(submitted != nr)) {
+ int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
+ int unused = nr - ref_used;
+
+ current->io_uring->cached_refs += unused;
+ percpu_ref_put_many(&ctx->refs, unused);
+ }
+
+ io_submit_state_end(&ctx->submit_state, ctx);
+ /* Commit SQ ring head once we've consumed and submitted all SQEs */
+ io_commit_sqring(ctx);
+
+ return submitted;
+}
+
+static inline bool io_sqd_events_pending(struct io_sq_data *sqd)
+{
+ return READ_ONCE(sqd->state);
+}
+
+static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx)
+{
+ /* Tell userspace we may need a wakeup call */
+ spin_lock(&ctx->completion_lock);
+ WRITE_ONCE(ctx->rings->sq_flags,
+ ctx->rings->sq_flags | IORING_SQ_NEED_WAKEUP);
+ spin_unlock(&ctx->completion_lock);
+}
+
+static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx)
+{
+ spin_lock(&ctx->completion_lock);
+ WRITE_ONCE(ctx->rings->sq_flags,
+ ctx->rings->sq_flags & ~IORING_SQ_NEED_WAKEUP);
+ spin_unlock(&ctx->completion_lock);
+}
+
+static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
+{
+ unsigned int to_submit;
+ int ret = 0;
+
+ to_submit = io_sqring_entries(ctx);
+ /* if we're handling multiple rings, cap submit size for fairness */
+ if (cap_entries && to_submit > IORING_SQPOLL_CAP_ENTRIES_VALUE)
+ to_submit = IORING_SQPOLL_CAP_ENTRIES_VALUE;
+
+ if (!list_empty(&ctx->iopoll_list) || to_submit) {
+ unsigned nr_events = 0;
+ const struct cred *creds = NULL;
+
+ if (ctx->sq_creds != current_cred())
+ creds = override_creds(ctx->sq_creds);
+
+ mutex_lock(&ctx->uring_lock);
+ if (!list_empty(&ctx->iopoll_list))
+ io_do_iopoll(ctx, &nr_events, 0);
+
+ /*
+ * Don't submit if refs are dying, good for io_uring_register(),
+ * but also it is relied upon by io_ring_exit_work()
+ */
+ if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs)) &&
+ !(ctx->flags & IORING_SETUP_R_DISABLED))
+ ret = io_submit_sqes(ctx, to_submit);
+ mutex_unlock(&ctx->uring_lock);
+
+ if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait))
+ wake_up(&ctx->sqo_sq_wait);
+ if (creds)
+ revert_creds(creds);
+ }
+
+ return ret;
+}
+
+static void io_sqd_update_thread_idle(struct io_sq_data *sqd)
+{
+ struct io_ring_ctx *ctx;
+ unsigned sq_thread_idle = 0;
+
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
+ sq_thread_idle = max(sq_thread_idle, ctx->sq_thread_idle);
+ sqd->sq_thread_idle = sq_thread_idle;
+}
+
+static bool io_sqd_handle_event(struct io_sq_data *sqd)
+{
+ bool did_sig = false;
+ struct ksignal ksig;
+
+ if (test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state) ||
+ signal_pending(current)) {
+ mutex_unlock(&sqd->lock);
+ if (signal_pending(current))
+ did_sig = get_signal(&ksig);
+ cond_resched();
+ mutex_lock(&sqd->lock);
+ }
+ return did_sig || test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state);
+}
+
+static int io_sq_thread(void *data)
+{
+ struct io_sq_data *sqd = data;
+ struct io_ring_ctx *ctx;
+ unsigned long timeout = 0;
+ char buf[TASK_COMM_LEN];
+ DEFINE_WAIT(wait);
+
+ snprintf(buf, sizeof(buf), "iou-sqp-%d", sqd->task_pid);
+ set_task_comm(current, buf);
+
+ if (sqd->sq_cpu != -1)
+ set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu));
+ else
+ set_cpus_allowed_ptr(current, cpu_online_mask);
+ current->flags |= PF_NO_SETAFFINITY;
+
+ mutex_lock(&sqd->lock);
+ while (1) {
+ bool cap_entries, sqt_spin = false;
+
+ if (io_sqd_events_pending(sqd) || signal_pending(current)) {
+ if (io_sqd_handle_event(sqd))
+ break;
+ timeout = jiffies + sqd->sq_thread_idle;
+ }
+
+ cap_entries = !list_is_singular(&sqd->ctx_list);
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
+ int ret = __io_sq_thread(ctx, cap_entries);
+
+ if (!sqt_spin && (ret > 0 || !list_empty(&ctx->iopoll_list)))
+ sqt_spin = true;
+ }
+ if (io_run_task_work())
+ sqt_spin = true;
+
+ if (sqt_spin || !time_after(jiffies, timeout)) {
+ cond_resched();
+ if (sqt_spin)
+ timeout = jiffies + sqd->sq_thread_idle;
+ continue;
+ }
+
+ prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE);
+ if (!io_sqd_events_pending(sqd) && !current->task_works) {
+ bool needs_sched = true;
+
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
+ io_ring_set_wakeup_flag(ctx);
+
+ if ((ctx->flags & IORING_SETUP_IOPOLL) &&
+ !list_empty_careful(&ctx->iopoll_list)) {
+ needs_sched = false;
+ break;
+ }
+ if (io_sqring_entries(ctx)) {
+ needs_sched = false;
+ break;
+ }
+ }
+
+ if (needs_sched) {
+ mutex_unlock(&sqd->lock);
+ schedule();
+ mutex_lock(&sqd->lock);
+ }
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
+ io_ring_clear_wakeup_flag(ctx);
+ }
+
+ finish_wait(&sqd->wait, &wait);
+ timeout = jiffies + sqd->sq_thread_idle;
+ }
+
+ io_uring_cancel_generic(true, sqd);
+ sqd->thread = NULL;
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
+ io_ring_set_wakeup_flag(ctx);
+ io_run_task_work();
+ mutex_unlock(&sqd->lock);
+
+ complete(&sqd->exited);
+ do_exit(0);
+}
+
+struct io_wait_queue {
+ struct wait_queue_entry wq;
+ struct io_ring_ctx *ctx;
+ unsigned cq_tail;
+ unsigned nr_timeouts;
+};
+
+static inline bool io_should_wake(struct io_wait_queue *iowq)
+{
+ struct io_ring_ctx *ctx = iowq->ctx;
+ int dist = ctx->cached_cq_tail - (int) iowq->cq_tail;
+
+ /*
+ * Wake up if we have enough events, or if a timeout occurred since we
+ * started waiting. For timeouts, we always want to return to userspace,
+ * regardless of event count.
+ */
+ return dist >= 0 || atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts;
+}
+
+static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
+ int wake_flags, void *key)
+{
+ struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue,
+ wq);
+
+ /*
+ * Cannot safely flush overflowed CQEs from here, ensure we wake up
+ * the task, and the next invocation will do it.
+ */
+ if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->check_cq_overflow))
+ return autoremove_wake_function(curr, mode, wake_flags, key);
+ return -1;
+}
+
+static int io_run_task_work_sig(void)
+{
+ if (io_run_task_work())
+ return 1;
+ if (!signal_pending(current))
+ return 0;
+ if (test_thread_flag(TIF_NOTIFY_SIGNAL))
+ return -ERESTARTSYS;
+ return -EINTR;
+}
+
+/* when returns >0, the caller should retry */
+static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq,
+ ktime_t timeout)
+{
+ int ret;
+
+ /* make sure we run task_work before checking for signals */
+ ret = io_run_task_work_sig();
+ if (ret || io_should_wake(iowq))
+ return ret;
+ /* let the caller flush overflows, retry */
+ if (test_bit(0, &ctx->check_cq_overflow))
+ return 1;
+
+ if (!schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS))
+ return -ETIME;
+ return 1;
+}
+
+/*
+ * Wait until events become available, if we don't already have some. The
+ * application must reap them itself, as they reside on the shared cq ring.
+ */
+static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
+ const sigset_t __user *sig, size_t sigsz,
+ struct __kernel_timespec __user *uts)
+{
+ struct io_wait_queue iowq;
+ struct io_rings *rings = ctx->rings;
+ ktime_t timeout = KTIME_MAX;
+ int ret;
+
+ do {
+ io_cqring_overflow_flush(ctx);
+ if (io_cqring_events(ctx) >= min_events)
+ return 0;
+ if (!io_run_task_work())
+ break;
+ } while (1);
+
+ if (uts) {
+ struct timespec64 ts;
+
+ if (get_timespec64(&ts, uts))
+ return -EFAULT;
+ timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns());
+ }
+
+ if (sig) {
+#ifdef CONFIG_COMPAT
+ if (in_compat_syscall())
+ ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
+ sigsz);
+ else
+#endif
+ ret = set_user_sigmask(sig, sigsz);
+
+ if (ret)
+ return ret;
+ }
+
+ init_waitqueue_func_entry(&iowq.wq, io_wake_function);
+ iowq.wq.private = current;
+ INIT_LIST_HEAD(&iowq.wq.entry);
+ iowq.ctx = ctx;
+ iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
+ iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events;
+
+ trace_io_uring_cqring_wait(ctx, min_events);
+ do {
+ /* if we can't even flush overflow, don't wait for more */
+ if (!io_cqring_overflow_flush(ctx)) {
+ ret = -EBUSY;
+ break;
+ }
+ prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq,
+ TASK_INTERRUPTIBLE);
+ ret = io_cqring_wait_schedule(ctx, &iowq, timeout);
+ finish_wait(&ctx->cq_wait, &iowq.wq);
+ cond_resched();
+ } while (ret > 0);
+
+ restore_saved_sigmask_unless(ret == -EINTR);
+
+ return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
+}
+
+static void io_free_page_table(void **table, size_t size)
+{
+ unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
+
+ for (i = 0; i < nr_tables; i++)
+ kfree(table[i]);
+ kfree(table);
+}
+
+static void **io_alloc_page_table(size_t size)
+{
+ unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
+ size_t init_size = size;
+ void **table;
+
+ table = kcalloc(nr_tables, sizeof(*table), GFP_KERNEL_ACCOUNT);
+ if (!table)
+ return NULL;
+
+ for (i = 0; i < nr_tables; i++) {
+ unsigned int this_size = min_t(size_t, size, PAGE_SIZE);
+
+ table[i] = kzalloc(this_size, GFP_KERNEL_ACCOUNT);
+ if (!table[i]) {
+ io_free_page_table(table, init_size);
+ return NULL;
+ }
+ size -= this_size;
+ }
+ return table;
+}
+
+static void io_rsrc_node_destroy(struct io_rsrc_node *ref_node)
+{
+ percpu_ref_exit(&ref_node->refs);
+ kfree(ref_node);
+}
+
+static void io_rsrc_node_ref_zero(struct percpu_ref *ref)
+{
+ struct io_rsrc_node *node = container_of(ref, struct io_rsrc_node, refs);
+ struct io_ring_ctx *ctx = node->rsrc_data->ctx;
+ unsigned long flags;
+ bool first_add = false;
+ unsigned long delay = HZ;
+
+ spin_lock_irqsave(&ctx->rsrc_ref_lock, flags);
+ node->done = true;
+
+ /* if we are mid-quiesce then do not delay */
+ if (node->rsrc_data->quiesce)
+ delay = 0;
+
+ while (!list_empty(&ctx->rsrc_ref_list)) {
+ node = list_first_entry(&ctx->rsrc_ref_list,
+ struct io_rsrc_node, node);
+ /* recycle ref nodes in order */
+ if (!node->done)
+ break;
+ list_del(&node->node);
+ first_add |= llist_add(&node->llist, &ctx->rsrc_put_llist);
+ }
+ spin_unlock_irqrestore(&ctx->rsrc_ref_lock, flags);
+
+ if (first_add)
+ mod_delayed_work(system_wq, &ctx->rsrc_put_work, delay);
+}
+
+static struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx)
+{
+ struct io_rsrc_node *ref_node;
+
+ ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
+ if (!ref_node)
+ return NULL;
+
+ if (percpu_ref_init(&ref_node->refs, io_rsrc_node_ref_zero,
+ 0, GFP_KERNEL)) {
+ kfree(ref_node);
+ return NULL;
+ }
+ INIT_LIST_HEAD(&ref_node->node);
+ INIT_LIST_HEAD(&ref_node->rsrc_list);
+ ref_node->done = false;
+ return ref_node;
+}
+
+static void io_rsrc_node_switch(struct io_ring_ctx *ctx,
+ struct io_rsrc_data *data_to_kill)
+{
+ WARN_ON_ONCE(!ctx->rsrc_backup_node);
+ WARN_ON_ONCE(data_to_kill && !ctx->rsrc_node);
+
+ if (data_to_kill) {
+ struct io_rsrc_node *rsrc_node = ctx->rsrc_node;
+
+ rsrc_node->rsrc_data = data_to_kill;
+ spin_lock_irq(&ctx->rsrc_ref_lock);
+ list_add_tail(&rsrc_node->node, &ctx->rsrc_ref_list);
+ spin_unlock_irq(&ctx->rsrc_ref_lock);
+
+ atomic_inc(&data_to_kill->refs);
+ percpu_ref_kill(&rsrc_node->refs);
+ ctx->rsrc_node = NULL;
+ }
+
+ if (!ctx->rsrc_node) {
+ ctx->rsrc_node = ctx->rsrc_backup_node;
+ ctx->rsrc_backup_node = NULL;
+ }
+}
+
+static int io_rsrc_node_switch_start(struct io_ring_ctx *ctx)
+{
+ if (ctx->rsrc_backup_node)
+ return 0;
+ ctx->rsrc_backup_node = io_rsrc_node_alloc(ctx);
+ return ctx->rsrc_backup_node ? 0 : -ENOMEM;
+}
+
+static int io_rsrc_ref_quiesce(struct io_rsrc_data *data, struct io_ring_ctx *ctx)
+{
+ int ret;
+
+ /* As we may drop ->uring_lock, other task may have started quiesce */
+ if (data->quiesce)
+ return -ENXIO;
+
+ data->quiesce = true;
+ do {
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ break;
+ io_rsrc_node_switch(ctx, data);
+
+ /* kill initial ref, already quiesced if zero */
+ if (atomic_dec_and_test(&data->refs))
+ break;
+ mutex_unlock(&ctx->uring_lock);
+ flush_delayed_work(&ctx->rsrc_put_work);
+ ret = wait_for_completion_interruptible(&data->done);
+ if (!ret) {
+ mutex_lock(&ctx->uring_lock);
+ if (atomic_read(&data->refs) > 0) {
+ /*
+ * it has been revived by another thread while
+ * we were unlocked
+ */
+ mutex_unlock(&ctx->uring_lock);
+ } else {
+ break;
+ }
+ }
+
+ atomic_inc(&data->refs);
+ /* wait for all works potentially completing data->done */
+ flush_delayed_work(&ctx->rsrc_put_work);
+ reinit_completion(&data->done);
+
+ ret = io_run_task_work_sig();
+ mutex_lock(&ctx->uring_lock);
+ } while (ret >= 0);
+ data->quiesce = false;
+
+ return ret;
+}
+
+static u64 *io_get_tag_slot(struct io_rsrc_data *data, unsigned int idx)
+{
+ unsigned int off = idx & IO_RSRC_TAG_TABLE_MASK;
+ unsigned int table_idx = idx >> IO_RSRC_TAG_TABLE_SHIFT;
+
+ return &data->tags[table_idx][off];
+}
+
+static void io_rsrc_data_free(struct io_rsrc_data *data)
+{
+ size_t size = data->nr * sizeof(data->tags[0][0]);
+
+ if (data->tags)
+ io_free_page_table((void **)data->tags, size);
+ kfree(data);
+}
+
+static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, rsrc_put_fn *do_put,
+ u64 __user *utags, unsigned nr,
+ struct io_rsrc_data **pdata)
+{
+ struct io_rsrc_data *data;
+ int ret = -ENOMEM;
+ unsigned i;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ data->tags = (u64 **)io_alloc_page_table(nr * sizeof(data->tags[0][0]));
+ if (!data->tags) {
+ kfree(data);
+ return -ENOMEM;
+ }
+
+ data->nr = nr;
+ data->ctx = ctx;
+ data->do_put = do_put;
+ if (utags) {
+ ret = -EFAULT;
+ for (i = 0; i < nr; i++) {
+ u64 *tag_slot = io_get_tag_slot(data, i);
+
+ if (copy_from_user(tag_slot, &utags[i],
+ sizeof(*tag_slot)))
+ goto fail;
+ }
+ }
+
+ atomic_set(&data->refs, 1);
+ init_completion(&data->done);
+ *pdata = data;
+ return 0;
+fail:
+ io_rsrc_data_free(data);
+ return ret;
+}
+
+static bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files)
+{
+ table->files = kvcalloc(nr_files, sizeof(table->files[0]),
+ GFP_KERNEL_ACCOUNT);
+ return !!table->files;
+}
+
+static void io_free_file_tables(struct io_file_table *table)
+{
+ kvfree(table->files);
+ table->files = NULL;
+}
+
+static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
+{
+#if defined(CONFIG_UNIX)
+ if (ctx->ring_sock) {
+ struct sock *sock = ctx->ring_sock->sk;
+ struct sk_buff *skb;
+
+ while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
+ kfree_skb(skb);
+ }
+#else
+ int i;
+
+ for (i = 0; i < ctx->nr_user_files; i++) {
+ struct file *file;
+
+ file = io_file_from_index(ctx, i);
+ if (file)
+ fput(file);
+ }
+#endif
+ io_free_file_tables(&ctx->file_table);
+ io_rsrc_data_free(ctx->file_data);
+ ctx->file_data = NULL;
+ ctx->nr_user_files = 0;
+}
+
+static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
+{
+ unsigned nr = ctx->nr_user_files;
+ int ret;
+
+ if (!ctx->file_data)
+ return -ENXIO;
+
+ /*
+ * Quiesce may unlock ->uring_lock, and while it's not held
+ * prevent new requests using the table.
+ */
+ ctx->nr_user_files = 0;
+ ret = io_rsrc_ref_quiesce(ctx->file_data, ctx);
+ ctx->nr_user_files = nr;
+ if (!ret)
+ __io_sqe_files_unregister(ctx);
+ return ret;
+}
+
+static void io_sq_thread_unpark(struct io_sq_data *sqd)
+ __releases(&sqd->lock)
+{
+ WARN_ON_ONCE(sqd->thread == current);
+
+ /*
+ * Do the dance but not conditional clear_bit() because it'd race with
+ * other threads incrementing park_pending and setting the bit.
+ */
+ clear_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
+ if (atomic_dec_return(&sqd->park_pending))
+ set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
+ mutex_unlock(&sqd->lock);
+}
+
+static void io_sq_thread_park(struct io_sq_data *sqd)
+ __acquires(&sqd->lock)
+{
+ WARN_ON_ONCE(sqd->thread == current);
+
+ atomic_inc(&sqd->park_pending);
+ set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
+ mutex_lock(&sqd->lock);
+ if (sqd->thread)
+ wake_up_process(sqd->thread);
+}
+
+static void io_sq_thread_stop(struct io_sq_data *sqd)
+{
+ WARN_ON_ONCE(sqd->thread == current);
+ WARN_ON_ONCE(test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state));
+
+ set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state);
+ mutex_lock(&sqd->lock);
+ if (sqd->thread)
+ wake_up_process(sqd->thread);
+ mutex_unlock(&sqd->lock);
+ wait_for_completion(&sqd->exited);
+}
+
+static void io_put_sq_data(struct io_sq_data *sqd)
+{
+ if (refcount_dec_and_test(&sqd->refs)) {
+ WARN_ON_ONCE(atomic_read(&sqd->park_pending));
+
+ io_sq_thread_stop(sqd);
+ kfree(sqd);
+ }
+}
+
+static void io_sq_thread_finish(struct io_ring_ctx *ctx)
+{
+ struct io_sq_data *sqd = ctx->sq_data;
+
+ if (sqd) {
+ io_sq_thread_park(sqd);
+ list_del_init(&ctx->sqd_list);
+ io_sqd_update_thread_idle(sqd);
+ io_sq_thread_unpark(sqd);
+
+ io_put_sq_data(sqd);
+ ctx->sq_data = NULL;
+ }
+}
+
+static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p)
+{
+ struct io_ring_ctx *ctx_attach;
+ struct io_sq_data *sqd;
+ struct fd f;
+
+ f = fdget(p->wq_fd);
+ if (!f.file)
+ return ERR_PTR(-ENXIO);
+ if (f.file->f_op != &io_uring_fops) {
+ fdput(f);
+ return ERR_PTR(-EINVAL);
+ }
+
+ ctx_attach = f.file->private_data;
+ sqd = ctx_attach->sq_data;
+ if (!sqd) {
+ fdput(f);
+ return ERR_PTR(-EINVAL);
+ }
+ if (sqd->task_tgid != current->tgid) {
+ fdput(f);
+ return ERR_PTR(-EPERM);
+ }
+
+ refcount_inc(&sqd->refs);
+ fdput(f);
+ return sqd;
+}
+
+static struct io_sq_data *io_get_sq_data(struct io_uring_params *p,
+ bool *attached)
+{
+ struct io_sq_data *sqd;
+
+ *attached = false;
+ if (p->flags & IORING_SETUP_ATTACH_WQ) {
+ sqd = io_attach_sq_data(p);
+ if (!IS_ERR(sqd)) {
+ *attached = true;
+ return sqd;
+ }
+ /* fall through for EPERM case, setup new sqd/task */
+ if (PTR_ERR(sqd) != -EPERM)
+ return sqd;
+ }
+
+ sqd = kzalloc(sizeof(*sqd), GFP_KERNEL);
+ if (!sqd)
+ return ERR_PTR(-ENOMEM);
+
+ atomic_set(&sqd->park_pending, 0);
+ refcount_set(&sqd->refs, 1);
+ INIT_LIST_HEAD(&sqd->ctx_list);
+ mutex_init(&sqd->lock);
+ init_waitqueue_head(&sqd->wait);
+ init_completion(&sqd->exited);
+ return sqd;
+}
+
+#if defined(CONFIG_UNIX)
+/*
+ * Ensure the UNIX gc is aware of our file set, so we are certain that
+ * the io_uring can be safely unregistered on process exit, even if we have
+ * loops in the file referencing.
+ */
+static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
+{
+ struct sock *sk = ctx->ring_sock->sk;
+ struct scm_fp_list *fpl;
+ struct sk_buff *skb;
+ int i, nr_files;
+
+ fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
+ if (!fpl)
+ return -ENOMEM;
+
+ skb = alloc_skb(0, GFP_KERNEL);
+ if (!skb) {
+ kfree(fpl);
+ return -ENOMEM;
+ }
+
+ skb->sk = sk;
+ skb->scm_io_uring = 1;
+
+ nr_files = 0;
+ fpl->user = get_uid(current_user());
+ for (i = 0; i < nr; i++) {
+ struct file *file = io_file_from_index(ctx, i + offset);
+
+ if (!file)
+ continue;
+ fpl->fp[nr_files] = get_file(file);
+ unix_inflight(fpl->user, fpl->fp[nr_files]);
+ nr_files++;
+ }
+
+ if (nr_files) {
+ fpl->max = SCM_MAX_FD;
+ fpl->count = nr_files;
+ UNIXCB(skb).fp = fpl;
+ skb->destructor = unix_destruct_scm;
+ refcount_add(skb->truesize, &sk->sk_wmem_alloc);
+ skb_queue_head(&sk->sk_receive_queue, skb);
+
+ for (i = 0; i < nr; i++) {
+ struct file *file = io_file_from_index(ctx, i + offset);
+
+ if (file)
+ fput(file);
+ }
+ } else {
+ kfree_skb(skb);
+ free_uid(fpl->user);
+ kfree(fpl);
+ }
+
+ return 0;
+}
+
+/*
+ * If UNIX sockets are enabled, fd passing can cause a reference cycle which
+ * causes regular reference counting to break down. We rely on the UNIX
+ * garbage collection to take care of this problem for us.
+ */
+static int io_sqe_files_scm(struct io_ring_ctx *ctx)
+{
+ unsigned left, total;
+ int ret = 0;
+
+ total = 0;
+ left = ctx->nr_user_files;
+ while (left) {
+ unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
+
+ ret = __io_sqe_files_scm(ctx, this_files, total);
+ if (ret)
+ break;
+ left -= this_files;
+ total += this_files;
+ }
+
+ if (!ret)
+ return 0;
+
+ while (total < ctx->nr_user_files) {
+ struct file *file = io_file_from_index(ctx, total);
+
+ if (file)
+ fput(file);
+ total++;
+ }
+
+ return ret;
+}
+#else
+static int io_sqe_files_scm(struct io_ring_ctx *ctx)
+{
+ return 0;
+}
+#endif
+
+static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
+{
+ struct file *file = prsrc->file;
+#if defined(CONFIG_UNIX)
+ struct sock *sock = ctx->ring_sock->sk;
+ struct sk_buff_head list, *head = &sock->sk_receive_queue;
+ struct sk_buff *skb;
+ int i;
+
+ __skb_queue_head_init(&list);
+
+ /*
+ * Find the skb that holds this file in its SCM_RIGHTS. When found,
+ * remove this entry and rearrange the file array.
+ */
+ skb = skb_dequeue(head);
+ while (skb) {
+ struct scm_fp_list *fp;
+
+ fp = UNIXCB(skb).fp;
+ for (i = 0; i < fp->count; i++) {
+ int left;
+
+ if (fp->fp[i] != file)
+ continue;
+
+ unix_notinflight(fp->user, fp->fp[i]);
+ left = fp->count - 1 - i;
+ if (left) {
+ memmove(&fp->fp[i], &fp->fp[i + 1],
+ left * sizeof(struct file *));
+ }
+ fp->count--;
+ if (!fp->count) {
+ kfree_skb(skb);
+ skb = NULL;
+ } else {
+ __skb_queue_tail(&list, skb);
+ }
+ fput(file);
+ file = NULL;
+ break;
+ }
+
+ if (!file)
+ break;
+
+ __skb_queue_tail(&list, skb);
+
+ skb = skb_dequeue(head);
+ }
+
+ if (skb_peek(&list)) {
+ spin_lock_irq(&head->lock);
+ while ((skb = __skb_dequeue(&list)) != NULL)
+ __skb_queue_tail(head, skb);
+ spin_unlock_irq(&head->lock);
+ }
+#else
+ fput(file);
+#endif
+}
+
+static void __io_rsrc_put_work(struct io_rsrc_node *ref_node)
+{
+ struct io_rsrc_data *rsrc_data = ref_node->rsrc_data;
+ struct io_ring_ctx *ctx = rsrc_data->ctx;
+ struct io_rsrc_put *prsrc, *tmp;
+
+ list_for_each_entry_safe(prsrc, tmp, &ref_node->rsrc_list, list) {
+ list_del(&prsrc->list);
+
+ if (prsrc->tag) {
+ bool lock_ring = ctx->flags & IORING_SETUP_IOPOLL;
+
+ io_ring_submit_lock(ctx, lock_ring);
+ spin_lock(&ctx->completion_lock);
+ io_fill_cqe_aux(ctx, prsrc->tag, 0, 0);
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ io_cqring_ev_posted(ctx);
+ io_ring_submit_unlock(ctx, lock_ring);
+ }
+
+ rsrc_data->do_put(ctx, prsrc);
+ kfree(prsrc);
+ }
+
+ io_rsrc_node_destroy(ref_node);
+ if (atomic_dec_and_test(&rsrc_data->refs))
+ complete(&rsrc_data->done);
+}
+
+static void io_rsrc_put_work(struct work_struct *work)
+{
+ struct io_ring_ctx *ctx;
+ struct llist_node *node;
+
+ ctx = container_of(work, struct io_ring_ctx, rsrc_put_work.work);
+ node = llist_del_all(&ctx->rsrc_put_llist);
+
+ while (node) {
+ struct io_rsrc_node *ref_node;
+ struct llist_node *next = node->next;
+
+ ref_node = llist_entry(node, struct io_rsrc_node, llist);
+ __io_rsrc_put_work(ref_node);
+ node = next;
+ }
+}
+
+static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned nr_args, u64 __user *tags)
+{
+ __s32 __user *fds = (__s32 __user *) arg;
+ struct file *file;
+ int fd, ret;
+ unsigned i;
+
+ if (ctx->file_data)
+ return -EBUSY;
+ if (!nr_args)
+ return -EINVAL;
+ if (nr_args > IORING_MAX_FIXED_FILES)
+ return -EMFILE;
+ if (nr_args > rlimit(RLIMIT_NOFILE))
+ return -EMFILE;
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ return ret;
+ ret = io_rsrc_data_alloc(ctx, io_rsrc_file_put, tags, nr_args,
+ &ctx->file_data);
+ if (ret)
+ return ret;
+
+ ret = -ENOMEM;
+ if (!io_alloc_file_tables(&ctx->file_table, nr_args))
+ goto out_free;
+
+ for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
+ if (copy_from_user(&fd, &fds[i], sizeof(fd))) {
+ ret = -EFAULT;
+ goto out_fput;
+ }
+ /* allow sparse sets */
+ if (fd == -1) {
+ ret = -EINVAL;
+ if (unlikely(*io_get_tag_slot(ctx->file_data, i)))
+ goto out_fput;
+ continue;
+ }
+
+ file = fget(fd);
+ ret = -EBADF;
+ if (unlikely(!file))
+ goto out_fput;
+
+ /*
+ * Don't allow io_uring instances to be registered. If UNIX
+ * isn't enabled, then this causes a reference cycle and this
+ * instance can never get freed. If UNIX is enabled we'll
+ * handle it just fine, but there's still no point in allowing
+ * a ring fd as it doesn't support regular read/write anyway.
+ */
+ if (file->f_op == &io_uring_fops) {
+ fput(file);
+ goto out_fput;
+ }
+ io_fixed_file_set(io_fixed_file_slot(&ctx->file_table, i), file);
+ }
+
+ ret = io_sqe_files_scm(ctx);
+ if (ret) {
+ __io_sqe_files_unregister(ctx);
+ return ret;
+ }
+
+ io_rsrc_node_switch(ctx, NULL);
+ return ret;
+out_fput:
+ for (i = 0; i < ctx->nr_user_files; i++) {
+ file = io_file_from_index(ctx, i);
+ if (file)
+ fput(file);
+ }
+ io_free_file_tables(&ctx->file_table);
+ ctx->nr_user_files = 0;
+out_free:
+ io_rsrc_data_free(ctx->file_data);
+ ctx->file_data = NULL;
+ return ret;
+}
+
+static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
+ int index)
+{
+#if defined(CONFIG_UNIX)
+ struct sock *sock = ctx->ring_sock->sk;
+ struct sk_buff_head *head = &sock->sk_receive_queue;
+ struct sk_buff *skb;
+
+ /*
+ * See if we can merge this file into an existing skb SCM_RIGHTS
+ * file set. If there's no room, fall back to allocating a new skb
+ * and filling it in.
+ */
+ spin_lock_irq(&head->lock);
+ skb = skb_peek(head);
+ if (skb) {
+ struct scm_fp_list *fpl = UNIXCB(skb).fp;
+
+ if (fpl->count < SCM_MAX_FD) {
+ __skb_unlink(skb, head);
+ spin_unlock_irq(&head->lock);
+ fpl->fp[fpl->count] = get_file(file);
+ unix_inflight(fpl->user, fpl->fp[fpl->count]);
+ fpl->count++;
+ spin_lock_irq(&head->lock);
+ __skb_queue_head(head, skb);
+ } else {
+ skb = NULL;
+ }
+ }
+ spin_unlock_irq(&head->lock);
+
+ if (skb) {
+ fput(file);
+ return 0;
+ }
+
+ return __io_sqe_files_scm(ctx, 1, index);
+#else
+ return 0;
+#endif
+}
+
+static int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx,
+ struct io_rsrc_node *node, void *rsrc)
+{
+ u64 *tag_slot = io_get_tag_slot(data, idx);
+ struct io_rsrc_put *prsrc;
+
+ prsrc = kzalloc(sizeof(*prsrc), GFP_KERNEL);
+ if (!prsrc)
+ return -ENOMEM;
+
+ prsrc->tag = *tag_slot;
+ *tag_slot = 0;
+ prsrc->rsrc = rsrc;
+ list_add(&prsrc->list, &node->rsrc_list);
+ return 0;
+}
+
+static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
+ unsigned int issue_flags, u32 slot_index)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ bool needs_switch = false;
+ struct io_fixed_file *file_slot;
+ int ret = -EBADF;
+
+ io_ring_submit_lock(ctx, !force_nonblock);
+ if (file->f_op == &io_uring_fops)
+ goto err;
+ ret = -ENXIO;
+ if (!ctx->file_data)
+ goto err;
+ ret = -EINVAL;
+ if (slot_index >= ctx->nr_user_files)
+ goto err;
+
+ slot_index = array_index_nospec(slot_index, ctx->nr_user_files);
+ file_slot = io_fixed_file_slot(&ctx->file_table, slot_index);
+
+ if (file_slot->file_ptr) {
+ struct file *old_file;
+
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ goto err;
+
+ old_file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+ ret = io_queue_rsrc_removal(ctx->file_data, slot_index,
+ ctx->rsrc_node, old_file);
+ if (ret)
+ goto err;
+ file_slot->file_ptr = 0;
+ needs_switch = true;
+ }
+
+ *io_get_tag_slot(ctx->file_data, slot_index) = 0;
+ io_fixed_file_set(file_slot, file);
+ ret = io_sqe_file_register(ctx, file, slot_index);
+ if (ret) {
+ file_slot->file_ptr = 0;
+ goto err;
+ }
+
+ ret = 0;
+err:
+ if (needs_switch)
+ io_rsrc_node_switch(ctx, ctx->file_data);
+ io_ring_submit_unlock(ctx, !force_nonblock);
+ if (ret)
+ fput(file);
+ return ret;
+}
+
+static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags)
+{
+ unsigned int offset = req->close.file_slot - 1;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_fixed_file *file_slot;
+ struct file *file;
+ int ret;
+
+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+ ret = -ENXIO;
+ if (unlikely(!ctx->file_data))
+ goto out;
+ ret = -EINVAL;
+ if (offset >= ctx->nr_user_files)
+ goto out;
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ goto out;
+
+ offset = array_index_nospec(offset, ctx->nr_user_files);
+ file_slot = io_fixed_file_slot(&ctx->file_table, offset);
+ ret = -EBADF;
+ if (!file_slot->file_ptr)
+ goto out;
+
+ file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+ ret = io_queue_rsrc_removal(ctx->file_data, offset, ctx->rsrc_node, file);
+ if (ret)
+ goto out;
+
+ file_slot->file_ptr = 0;
+ io_rsrc_node_switch(ctx, ctx->file_data);
+ ret = 0;
+out:
+ io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+ return ret;
+}
+
+static int __io_sqe_files_update(struct io_ring_ctx *ctx,
+ struct io_uring_rsrc_update2 *up,
+ unsigned nr_args)
+{
+ u64 __user *tags = u64_to_user_ptr(up->tags);
+ __s32 __user *fds = u64_to_user_ptr(up->data);
+ struct io_rsrc_data *data = ctx->file_data;
+ struct io_fixed_file *file_slot;
+ struct file *file;
+ int fd, i, err = 0;
+ unsigned int done;
+ bool needs_switch = false;
+
+ if (!ctx->file_data)
+ return -ENXIO;
+ if (up->offset + nr_args > ctx->nr_user_files)
+ return -EINVAL;
+
+ for (done = 0; done < nr_args; done++) {
+ u64 tag = 0;
+
+ if ((tags && copy_from_user(&tag, &tags[done], sizeof(tag))) ||
+ copy_from_user(&fd, &fds[done], sizeof(fd))) {
+ err = -EFAULT;
+ break;
+ }
+ if ((fd == IORING_REGISTER_FILES_SKIP || fd == -1) && tag) {
+ err = -EINVAL;
+ break;
+ }
+ if (fd == IORING_REGISTER_FILES_SKIP)
+ continue;
+
+ i = array_index_nospec(up->offset + done, ctx->nr_user_files);
+ file_slot = io_fixed_file_slot(&ctx->file_table, i);
+
+ if (file_slot->file_ptr) {
+ file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+ err = io_queue_rsrc_removal(data, i, ctx->rsrc_node, file);
+ if (err)
+ break;
+ file_slot->file_ptr = 0;
+ needs_switch = true;
+ }
+ if (fd != -1) {
+ file = fget(fd);
+ if (!file) {
+ err = -EBADF;
+ break;
+ }
+ /*
+ * Don't allow io_uring instances to be registered. If
+ * UNIX isn't enabled, then this causes a reference
+ * cycle and this instance can never get freed. If UNIX
+ * is enabled we'll handle it just fine, but there's
+ * still no point in allowing a ring fd as it doesn't
+ * support regular read/write anyway.
+ */
+ if (file->f_op == &io_uring_fops) {
+ fput(file);
+ err = -EBADF;
+ break;
+ }
+ *io_get_tag_slot(data, i) = tag;
+ io_fixed_file_set(file_slot, file);
+ err = io_sqe_file_register(ctx, file, i);
+ if (err) {
+ file_slot->file_ptr = 0;
+ fput(file);
+ break;
+ }
+ }
+ }
+
+ if (needs_switch)
+ io_rsrc_node_switch(ctx, data);
+ return done ? done : err;
+}
+
+static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx,
+ struct task_struct *task)
+{
+ struct io_wq_hash *hash;
+ struct io_wq_data data;
+ unsigned int concurrency;
+
+ mutex_lock(&ctx->uring_lock);
+ hash = ctx->hash_map;
+ if (!hash) {
+ hash = kzalloc(sizeof(*hash), GFP_KERNEL);
+ if (!hash) {
+ mutex_unlock(&ctx->uring_lock);
+ return ERR_PTR(-ENOMEM);
+ }
+ refcount_set(&hash->refs, 1);
+ init_waitqueue_head(&hash->wait);
+ ctx->hash_map = hash;
+ }
+ mutex_unlock(&ctx->uring_lock);
+
+ data.hash = hash;
+ data.task = task;
+ data.free_work = io_wq_free_work;
+ data.do_work = io_wq_submit_work;
+
+ /* Do QD, or 4 * CPUS, whatever is smallest */
+ concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
+
+ return io_wq_create(concurrency, &data);
+}
+
+static int io_uring_alloc_task_context(struct task_struct *task,
+ struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx;
+ int ret;
+
+ tctx = kzalloc(sizeof(*tctx), GFP_KERNEL);
+ if (unlikely(!tctx))
+ return -ENOMEM;
+
+ ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL);
+ if (unlikely(ret)) {
+ kfree(tctx);
+ return ret;
+ }
+
+ tctx->io_wq = io_init_wq_offload(ctx, task);
+ if (IS_ERR(tctx->io_wq)) {
+ ret = PTR_ERR(tctx->io_wq);
+ percpu_counter_destroy(&tctx->inflight);
+ kfree(tctx);
+ return ret;
+ }
+
+ xa_init(&tctx->xa);
+ init_waitqueue_head(&tctx->wait);
+ atomic_set(&tctx->in_idle, 0);
+ atomic_set(&tctx->inflight_tracked, 0);
+ task->io_uring = tctx;
+ spin_lock_init(&tctx->task_lock);
+ INIT_WQ_LIST(&tctx->task_list);
+ init_task_work(&tctx->task_work, tctx_task_work);
+ return 0;
+}
+
+void __io_uring_free(struct task_struct *tsk)
+{
+ struct io_uring_task *tctx = tsk->io_uring;
+
+ WARN_ON_ONCE(!xa_empty(&tctx->xa));
+ WARN_ON_ONCE(tctx->io_wq);
+ WARN_ON_ONCE(tctx->cached_refs);
+
+ percpu_counter_destroy(&tctx->inflight);
+ kfree(tctx);
+ tsk->io_uring = NULL;
+}
+
+static int io_sq_offload_create(struct io_ring_ctx *ctx,
+ struct io_uring_params *p)
+{
+ int ret;
+
+ /* Retain compatibility with failing for an invalid attach attempt */
+ if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) ==
+ IORING_SETUP_ATTACH_WQ) {
+ struct fd f;
+
+ f = fdget(p->wq_fd);
+ if (!f.file)
+ return -ENXIO;
+ if (f.file->f_op != &io_uring_fops) {
+ fdput(f);
+ return -EINVAL;
+ }
+ fdput(f);
+ }
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
+ struct task_struct *tsk;
+ struct io_sq_data *sqd;
+ bool attached;
+
+ sqd = io_get_sq_data(p, &attached);
+ if (IS_ERR(sqd)) {
+ ret = PTR_ERR(sqd);
+ goto err;
+ }
+
+ ctx->sq_creds = get_current_cred();
+ ctx->sq_data = sqd;
+ ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
+ if (!ctx->sq_thread_idle)
+ ctx->sq_thread_idle = HZ;
+
+ io_sq_thread_park(sqd);
+ list_add(&ctx->sqd_list, &sqd->ctx_list);
+ io_sqd_update_thread_idle(sqd);
+ /* don't attach to a dying SQPOLL thread, would be racy */
+ ret = (attached && !sqd->thread) ? -ENXIO : 0;
+ io_sq_thread_unpark(sqd);
+
+ if (ret < 0)
+ goto err;
+ if (attached)
+ return 0;
+
+ if (p->flags & IORING_SETUP_SQ_AFF) {
+ int cpu = p->sq_thread_cpu;
+
+ ret = -EINVAL;
+ if (cpu >= nr_cpu_ids || !cpu_online(cpu))
+ goto err_sqpoll;
+ sqd->sq_cpu = cpu;
+ } else {
+ sqd->sq_cpu = -1;
+ }
+
+ sqd->task_pid = current->pid;
+ sqd->task_tgid = current->tgid;
+ tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE);
+ if (IS_ERR(tsk)) {
+ ret = PTR_ERR(tsk);
+ goto err_sqpoll;
+ }
+
+ sqd->thread = tsk;
+ ret = io_uring_alloc_task_context(tsk, ctx);
+ wake_up_new_task(tsk);
+ if (ret)
+ goto err;
+ } else if (p->flags & IORING_SETUP_SQ_AFF) {
+ /* Can't have SQ_AFF without SQPOLL */
+ ret = -EINVAL;
+ goto err;
+ }
+
+ return 0;
+err_sqpoll:
+ complete(&ctx->sq_data->exited);
+err:
+ io_sq_thread_finish(ctx);
+ return ret;
+}
+
+static inline void __io_unaccount_mem(struct user_struct *user,
+ unsigned long nr_pages)
+{
+ atomic_long_sub(nr_pages, &user->locked_vm);
+}
+
+static inline int __io_account_mem(struct user_struct *user,
+ unsigned long nr_pages)
+{
+ unsigned long page_limit, cur_pages, new_pages;
+
+ /* Don't allow more pages than we can safely lock */
+ page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+
+ do {
+ cur_pages = atomic_long_read(&user->locked_vm);
+ new_pages = cur_pages + nr_pages;
+ if (new_pages > page_limit)
+ return -ENOMEM;
+ } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
+ new_pages) != cur_pages);
+
+ return 0;
+}
+
+static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
+{
+ if (ctx->user)
+ __io_unaccount_mem(ctx->user, nr_pages);
+
+ if (ctx->mm_account)
+ atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
+}
+
+static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
+{
+ int ret;
+
+ if (ctx->user) {
+ ret = __io_account_mem(ctx->user, nr_pages);
+ if (ret)
+ return ret;
+ }
+
+ if (ctx->mm_account)
+ atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
+
+ return 0;
+}
+
+static void io_mem_free(void *ptr)
+{
+ struct page *page;
+
+ if (!ptr)
+ return;
+
+ page = virt_to_head_page(ptr);
+ if (put_page_testzero(page))
+ free_compound_page(page);
+}
+
+static void *io_mem_alloc(size_t size)
+{
+ gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP;
+
+ return (void *) __get_free_pages(gfp, get_order(size));
+}
+
+static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
+ size_t *sq_offset)
+{
+ struct io_rings *rings;
+ size_t off, sq_array_size;
+
+ off = struct_size(rings, cqes, cq_entries);
+ if (off == SIZE_MAX)
+ return SIZE_MAX;
+
+#ifdef CONFIG_SMP
+ off = ALIGN(off, SMP_CACHE_BYTES);
+ if (off == 0)
+ return SIZE_MAX;
+#endif
+
+ if (sq_offset)
+ *sq_offset = off;
+
+ sq_array_size = array_size(sizeof(u32), sq_entries);
+ if (sq_array_size == SIZE_MAX)
+ return SIZE_MAX;
+
+ if (check_add_overflow(off, sq_array_size, &off))
+ return SIZE_MAX;
+
+ return off;
+}
+
+static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slot)
+{
+ struct io_mapped_ubuf *imu = *slot;
+ unsigned int i;
+
+ if (imu != ctx->dummy_ubuf) {
+ for (i = 0; i < imu->nr_bvecs; i++)
+ unpin_user_page(imu->bvec[i].bv_page);
+ if (imu->acct_pages)
+ io_unaccount_mem(ctx, imu->acct_pages);
+ kvfree(imu);
+ }
+ *slot = NULL;
+}
+
+static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
+{
+ io_buffer_unmap(ctx, &prsrc->buf);
+ prsrc->buf = NULL;
+}
+
+static void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
+{
+ unsigned int i;
+
+ for (i = 0; i < ctx->nr_user_bufs; i++)
+ io_buffer_unmap(ctx, &ctx->user_bufs[i]);
+ kfree(ctx->user_bufs);
+ io_rsrc_data_free(ctx->buf_data);
+ ctx->user_bufs = NULL;
+ ctx->buf_data = NULL;
+ ctx->nr_user_bufs = 0;
+}
+
+static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
+{
+ unsigned nr = ctx->nr_user_bufs;
+ int ret;
+
+ if (!ctx->buf_data)
+ return -ENXIO;
+
+ /*
+ * Quiesce may unlock ->uring_lock, and while it's not held
+ * prevent new requests using the table.
+ */
+ ctx->nr_user_bufs = 0;
+ ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx);
+ ctx->nr_user_bufs = nr;
+ if (!ret)
+ __io_sqe_buffers_unregister(ctx);
+ return ret;
+}
+
+static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
+ void __user *arg, unsigned index)
+{
+ struct iovec __user *src;
+
+#ifdef CONFIG_COMPAT
+ if (ctx->compat) {
+ struct compat_iovec __user *ciovs;
+ struct compat_iovec ciov;
+
+ ciovs = (struct compat_iovec __user *) arg;
+ if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
+ return -EFAULT;
+
+ dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
+ dst->iov_len = ciov.iov_len;
+ return 0;
+ }
+#endif
+ src = (struct iovec __user *) arg;
+ if (copy_from_user(dst, &src[index], sizeof(*dst)))
+ return -EFAULT;
+ return 0;
+}
+
+/*
+ * Not super efficient, but this is just a registration time. And we do cache
+ * the last compound head, so generally we'll only do a full search if we don't
+ * match that one.
+ *
+ * We check if the given compound head page has already been accounted, to
+ * avoid double accounting it. This allows us to account the full size of the
+ * page, not just the constituent pages of a huge page.
+ */
+static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
+ int nr_pages, struct page *hpage)
+{
+ int i, j;
+
+ /* check current page array */
+ for (i = 0; i < nr_pages; i++) {
+ if (!PageCompound(pages[i]))
+ continue;
+ if (compound_head(pages[i]) == hpage)
+ return true;
+ }
+
+ /* check previously registered pages */
+ for (i = 0; i < ctx->nr_user_bufs; i++) {
+ struct io_mapped_ubuf *imu = ctx->user_bufs[i];
+
+ for (j = 0; j < imu->nr_bvecs; j++) {
+ if (!PageCompound(imu->bvec[j].bv_page))
+ continue;
+ if (compound_head(imu->bvec[j].bv_page) == hpage)
+ return true;
+ }
+ }
+
+ return false;
+}
+
+static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
+ int nr_pages, struct io_mapped_ubuf *imu,
+ struct page **last_hpage)
+{
+ int i, ret;
+
+ imu->acct_pages = 0;
+ for (i = 0; i < nr_pages; i++) {
+ if (!PageCompound(pages[i])) {
+ imu->acct_pages++;
+ } else {
+ struct page *hpage;
+
+ hpage = compound_head(pages[i]);
+ if (hpage == *last_hpage)
+ continue;
+ *last_hpage = hpage;
+ if (headpage_already_acct(ctx, pages, i, hpage))
+ continue;
+ imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
+ }
+ }
+
+ if (!imu->acct_pages)
+ return 0;
+
+ ret = io_account_mem(ctx, imu->acct_pages);
+ if (ret)
+ imu->acct_pages = 0;
+ return ret;
+}
+
+static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
+ struct io_mapped_ubuf **pimu,
+ struct page **last_hpage)
+{
+ struct io_mapped_ubuf *imu = NULL;
+ struct vm_area_struct **vmas = NULL;
+ struct page **pages = NULL;
+ unsigned long off, start, end, ubuf;
+ size_t size;
+ int ret, pret, nr_pages, i;
+
+ if (!iov->iov_base) {
+ *pimu = ctx->dummy_ubuf;
+ return 0;
+ }
+
+ ubuf = (unsigned long) iov->iov_base;
+ end = (ubuf + iov->iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ start = ubuf >> PAGE_SHIFT;
+ nr_pages = end - start;
+
+ *pimu = NULL;
+ ret = -ENOMEM;
+
+ pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
+ if (!pages)
+ goto done;
+
+ vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *),
+ GFP_KERNEL);
+ if (!vmas)
+ goto done;
+
+ imu = kvmalloc(struct_size(imu, bvec, nr_pages), GFP_KERNEL);
+ if (!imu)
+ goto done;
+
+ ret = 0;
+ mmap_read_lock(current->mm);
+ pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
+ pages, vmas);
+ if (pret == nr_pages) {
+ /* don't support file backed memory */
+ for (i = 0; i < nr_pages; i++) {
+ struct vm_area_struct *vma = vmas[i];
+
+ if (vma_is_shmem(vma))
+ continue;
+ if (vma->vm_file &&
+ !is_file_hugepages(vma->vm_file)) {
+ ret = -EOPNOTSUPP;
+ break;
+ }
+ }
+ } else {
+ ret = pret < 0 ? pret : -EFAULT;
+ }
+ mmap_read_unlock(current->mm);
+ if (ret) {
+ /*
+ * if we did partial map, or found file backed vmas,
+ * release any pages we did get
+ */
+ if (pret > 0)
+ unpin_user_pages(pages, pret);
+ goto done;
+ }
+
+ ret = io_buffer_account_pin(ctx, pages, pret, imu, last_hpage);
+ if (ret) {
+ unpin_user_pages(pages, pret);
+ goto done;
+ }
+
+ off = ubuf & ~PAGE_MASK;
+ size = iov->iov_len;
+ for (i = 0; i < nr_pages; i++) {
+ size_t vec_len;
+
+ vec_len = min_t(size_t, size, PAGE_SIZE - off);
+ imu->bvec[i].bv_page = pages[i];
+ imu->bvec[i].bv_len = vec_len;
+ imu->bvec[i].bv_offset = off;
+ off = 0;
+ size -= vec_len;
+ }
+ /* store original address for later verification */
+ imu->ubuf = ubuf;
+ imu->ubuf_end = ubuf + iov->iov_len;
+ imu->nr_bvecs = nr_pages;
+ *pimu = imu;
+ ret = 0;
+done:
+ if (ret)
+ kvfree(imu);
+ kvfree(pages);
+ kvfree(vmas);
+ return ret;
+}
+
+static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args)
+{
+ ctx->user_bufs = kcalloc(nr_args, sizeof(*ctx->user_bufs), GFP_KERNEL);
+ return ctx->user_bufs ? 0 : -ENOMEM;
+}
+
+static int io_buffer_validate(struct iovec *iov)
+{
+ unsigned long tmp, acct_len = iov->iov_len + (PAGE_SIZE - 1);
+
+ /*
+ * Don't impose further limits on the size and buffer
+ * constraints here, we'll -EINVAL later when IO is
+ * submitted if they are wrong.
+ */
+ if (!iov->iov_base)
+ return iov->iov_len ? -EFAULT : 0;
+ if (!iov->iov_len)
+ return -EFAULT;
+
+ /* arbitrary limit, but we need something */
+ if (iov->iov_len > SZ_1G)
+ return -EFAULT;
+
+ if (check_add_overflow((unsigned long)iov->iov_base, acct_len, &tmp))
+ return -EOVERFLOW;
+
+ return 0;
+}
+
+static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned int nr_args, u64 __user *tags)
+{
+ struct page *last_hpage = NULL;
+ struct io_rsrc_data *data;
+ int i, ret;
+ struct iovec iov;
+
+ if (ctx->user_bufs)
+ return -EBUSY;
+ if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS)
+ return -EINVAL;
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ return ret;
+ ret = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, tags, nr_args, &data);
+ if (ret)
+ return ret;
+ ret = io_buffers_map_alloc(ctx, nr_args);
+ if (ret) {
+ io_rsrc_data_free(data);
+ return ret;
+ }
+
+ for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) {
+ ret = io_copy_iov(ctx, &iov, arg, i);
+ if (ret)
+ break;
+ ret = io_buffer_validate(&iov);
+ if (ret)
+ break;
+ if (!iov.iov_base && *io_get_tag_slot(data, i)) {
+ ret = -EINVAL;
+ break;
+ }
+
+ ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],
+ &last_hpage);
+ if (ret)
+ break;
+ }
+
+ WARN_ON_ONCE(ctx->buf_data);
+
+ ctx->buf_data = data;
+ if (ret)
+ __io_sqe_buffers_unregister(ctx);
+ else
+ io_rsrc_node_switch(ctx, NULL);
+ return ret;
+}
+
+static int __io_sqe_buffers_update(struct io_ring_ctx *ctx,
+ struct io_uring_rsrc_update2 *up,
+ unsigned int nr_args)
+{
+ u64 __user *tags = u64_to_user_ptr(up->tags);
+ struct iovec iov, __user *iovs = u64_to_user_ptr(up->data);
+ struct page *last_hpage = NULL;
+ bool needs_switch = false;
+ __u32 done;
+ int i, err;
+
+ if (!ctx->buf_data)
+ return -ENXIO;
+ if (up->offset + nr_args > ctx->nr_user_bufs)
+ return -EINVAL;
+
+ for (done = 0; done < nr_args; done++) {
+ struct io_mapped_ubuf *imu;
+ int offset = up->offset + done;
+ u64 tag = 0;
+
+ err = io_copy_iov(ctx, &iov, iovs, done);
+ if (err)
+ break;
+ if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) {
+ err = -EFAULT;
+ break;
+ }
+ err = io_buffer_validate(&iov);
+ if (err)
+ break;
+ if (!iov.iov_base && tag) {
+ err = -EINVAL;
+ break;
+ }
+ err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage);
+ if (err)
+ break;
+
+ i = array_index_nospec(offset, ctx->nr_user_bufs);
+ if (ctx->user_bufs[i] != ctx->dummy_ubuf) {
+ err = io_queue_rsrc_removal(ctx->buf_data, i,
+ ctx->rsrc_node, ctx->user_bufs[i]);
+ if (unlikely(err)) {
+ io_buffer_unmap(ctx, &imu);
+ break;
+ }
+ ctx->user_bufs[i] = NULL;
+ needs_switch = true;
+ }
+
+ ctx->user_bufs[i] = imu;
+ *io_get_tag_slot(ctx->buf_data, offset) = tag;
+ }
+
+ if (needs_switch)
+ io_rsrc_node_switch(ctx, ctx->buf_data);
+ return done ? done : err;
+}
+
+static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
+{
+ __s32 __user *fds = arg;
+ int fd;
+
+ if (ctx->cq_ev_fd)
+ return -EBUSY;
+
+ if (copy_from_user(&fd, fds, sizeof(*fds)))
+ return -EFAULT;
+
+ ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
+ if (IS_ERR(ctx->cq_ev_fd)) {
+ int ret = PTR_ERR(ctx->cq_ev_fd);
+
+ ctx->cq_ev_fd = NULL;
+ return ret;
+ }
+
+ return 0;
+}
+
+static int io_eventfd_unregister(struct io_ring_ctx *ctx)
+{
+ if (ctx->cq_ev_fd) {
+ eventfd_ctx_put(ctx->cq_ev_fd);
+ ctx->cq_ev_fd = NULL;
+ return 0;
+ }
+
+ return -ENXIO;
+}
+
+static void io_destroy_buffers(struct io_ring_ctx *ctx)
+{
+ struct io_buffer *buf;
+ unsigned long index;
+
+ xa_for_each(&ctx->io_buffers, index, buf)
+ __io_remove_buffers(ctx, buf, index, -1U);
+}
+
+static void io_req_cache_free(struct list_head *list)
+{
+ struct io_kiocb *req, *nxt;
+
+ list_for_each_entry_safe(req, nxt, list, inflight_entry) {
+ list_del(&req->inflight_entry);
+ kmem_cache_free(req_cachep, req);
+ }
+}
+
+static void io_req_caches_free(struct io_ring_ctx *ctx)
+{
+ struct io_submit_state *state = &ctx->submit_state;
+
+ mutex_lock(&ctx->uring_lock);
+
+ if (state->free_reqs) {
+ kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
+ state->free_reqs = 0;
+ }
+
+ io_flush_cached_locked_reqs(ctx, state);
+ io_req_cache_free(&state->free_list);
+ mutex_unlock(&ctx->uring_lock);
+}
+
+static void io_wait_rsrc_data(struct io_rsrc_data *data)
+{
+ if (data && !atomic_dec_and_test(&data->refs))
+ wait_for_completion(&data->done);
+}
+
+static void io_ring_ctx_free(struct io_ring_ctx *ctx)
+{
+ io_sq_thread_finish(ctx);
+
+ /* __io_rsrc_put_work() may need uring_lock to progress, wait w/o it */
+ io_wait_rsrc_data(ctx->buf_data);
+ io_wait_rsrc_data(ctx->file_data);
+
+ mutex_lock(&ctx->uring_lock);
+ if (ctx->buf_data)
+ __io_sqe_buffers_unregister(ctx);
+ if (ctx->file_data)
+ __io_sqe_files_unregister(ctx);
+ if (ctx->rings)
+ __io_cqring_overflow_flush(ctx, true);
+ mutex_unlock(&ctx->uring_lock);
+ io_eventfd_unregister(ctx);
+ io_destroy_buffers(ctx);
+ if (ctx->sq_creds)
+ put_cred(ctx->sq_creds);
+
+ /* there are no registered resources left, nobody uses it */
+ if (ctx->rsrc_node)
+ io_rsrc_node_destroy(ctx->rsrc_node);
+ if (ctx->rsrc_backup_node)
+ io_rsrc_node_destroy(ctx->rsrc_backup_node);
+ flush_delayed_work(&ctx->rsrc_put_work);
+
+ WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
+ WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));
+
+#if defined(CONFIG_UNIX)
+ if (ctx->ring_sock) {
+ ctx->ring_sock->file = NULL; /* so that iput() is called */
+ sock_release(ctx->ring_sock);
+ }
+#endif
+ WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
+
+ if (ctx->mm_account) {
+ mmdrop(ctx->mm_account);
+ ctx->mm_account = NULL;
+ }
+
+ io_mem_free(ctx->rings);
+ io_mem_free(ctx->sq_sqes);
+
+ percpu_ref_exit(&ctx->refs);
+ free_uid(ctx->user);
+ io_req_caches_free(ctx);
+ if (ctx->hash_map)
+ io_wq_put_hash(ctx->hash_map);
+ kfree(ctx->cancel_hash);
+ kfree(ctx->dummy_ubuf);
+ kfree(ctx);
+}
+
+static __poll_t io_uring_poll(struct file *file, poll_table *wait)
+{
+ struct io_ring_ctx *ctx = file->private_data;
+ __poll_t mask = 0;
+
+ poll_wait(file, &ctx->poll_wait, wait);
+ /*
+ * synchronizes with barrier from wq_has_sleeper call in
+ * io_commit_cqring
+ */
+ smp_rmb();
+ if (!io_sqring_full(ctx))
+ mask |= EPOLLOUT | EPOLLWRNORM;
+
+ /*
+ * Don't flush cqring overflow list here, just do a simple check.
+ * Otherwise there could possible be ABBA deadlock:
+ * CPU0 CPU1
+ * ---- ----
+ * lock(&ctx->uring_lock);
+ * lock(&ep->mtx);
+ * lock(&ctx->uring_lock);
+ * lock(&ep->mtx);
+ *
+ * Users may get EPOLLIN meanwhile seeing nothing in cqring, this
+ * pushs them to do the flush.
+ */
+ if (io_cqring_events(ctx) || test_bit(0, &ctx->check_cq_overflow))
+ mask |= EPOLLIN | EPOLLRDNORM;
+
+ return mask;
+}
+
+static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
+{
+ const struct cred *creds;
+
+ creds = xa_erase(&ctx->personalities, id);
+ if (creds) {
+ put_cred(creds);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+struct io_tctx_exit {
+ struct callback_head task_work;
+ struct completion completion;
+ struct io_ring_ctx *ctx;
+};
+
+static void io_tctx_exit_cb(struct callback_head *cb)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_tctx_exit *work;
+
+ work = container_of(cb, struct io_tctx_exit, task_work);
+ /*
+ * When @in_idle, we're in cancellation and it's racy to remove the
+ * node. It'll be removed by the end of cancellation, just ignore it.
+ * tctx can be NULL if the queueing of this task_work raced with
+ * work cancelation off the exec path.
+ */
+ if (tctx && !atomic_read(&tctx->in_idle))
+ io_uring_del_tctx_node((unsigned long)work->ctx);
+ complete(&work->completion);
+}
+
+static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+
+ return req->ctx == data;
+}
+
+static void io_ring_exit_work(struct work_struct *work)
+{
+ struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work);
+ unsigned long timeout = jiffies + HZ * 60 * 5;
+ unsigned long interval = HZ / 20;
+ struct io_tctx_exit exit;
+ struct io_tctx_node *node;
+ int ret;
+
+ /*
+ * If we're doing polled IO and end up having requests being
+ * submitted async (out-of-line), then completions can come in while
+ * we're waiting for refs to drop. We need to reap these manually,
+ * as nobody else will be looking for them.
+ */
+ do {
+ io_uring_try_cancel_requests(ctx, NULL, true);
+ if (ctx->sq_data) {
+ struct io_sq_data *sqd = ctx->sq_data;
+ struct task_struct *tsk;
+
+ io_sq_thread_park(sqd);
+ tsk = sqd->thread;
+ if (tsk && tsk->io_uring && tsk->io_uring->io_wq)
+ io_wq_cancel_cb(tsk->io_uring->io_wq,
+ io_cancel_ctx_cb, ctx, true);
+ io_sq_thread_unpark(sqd);
+ }
+
+ if (WARN_ON_ONCE(time_after(jiffies, timeout))) {
+ /* there is little hope left, don't run it too often */
+ interval = HZ * 60;
+ }
+ } while (!wait_for_completion_timeout(&ctx->ref_comp, interval));
+
+ init_completion(&exit.completion);
+ init_task_work(&exit.task_work, io_tctx_exit_cb);
+ exit.ctx = ctx;
+ /*
+ * Some may use context even when all refs and requests have been put,
+ * and they are free to do so while still holding uring_lock or
+ * completion_lock, see io_req_task_submit(). Apart from other work,
+ * this lock/unlock section also waits them to finish.
+ */
+ mutex_lock(&ctx->uring_lock);
+ while (!list_empty(&ctx->tctx_list)) {
+ WARN_ON_ONCE(time_after(jiffies, timeout));
+
+ node = list_first_entry(&ctx->tctx_list, struct io_tctx_node,
+ ctx_node);
+ /* don't spin on a single task if cancellation failed */
+ list_rotate_left(&ctx->tctx_list);
+ ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL);
+ if (WARN_ON_ONCE(ret))
+ continue;
+ wake_up_process(node->task);
+
+ mutex_unlock(&ctx->uring_lock);
+ wait_for_completion(&exit.completion);
+ mutex_lock(&ctx->uring_lock);
+ }
+ mutex_unlock(&ctx->uring_lock);
+ spin_lock(&ctx->completion_lock);
+ spin_unlock(&ctx->completion_lock);
+
+ io_ring_ctx_free(ctx);
+}
+
+/* Returns true if we found and killed one or more timeouts */
+static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
+ bool cancel_all)
+{
+ struct io_kiocb *req, *tmp;
+ int canceled = 0;
+
+ spin_lock(&ctx->completion_lock);
+ spin_lock_irq(&ctx->timeout_lock);
+ list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
+ if (io_match_task(req, tsk, cancel_all)) {
+ io_kill_timeout(req, -ECANCELED);
+ canceled++;
+ }
+ }
+ spin_unlock_irq(&ctx->timeout_lock);
+ if (canceled != 0)
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ if (canceled != 0)
+ io_cqring_ev_posted(ctx);
+ return canceled != 0;
+}
+
+static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
+{
+ unsigned long index;
+ struct creds *creds;
+
+ mutex_lock(&ctx->uring_lock);
+ percpu_ref_kill(&ctx->refs);
+ if (ctx->rings)
+ __io_cqring_overflow_flush(ctx, true);
+ xa_for_each(&ctx->personalities, index, creds)
+ io_unregister_personality(ctx, index);
+ mutex_unlock(&ctx->uring_lock);
+
+ io_kill_timeouts(ctx, NULL, true);
+ io_poll_remove_all(ctx, NULL, true);
+
+ /* if we failed setting up the ctx, we might not have any rings */
+ io_iopoll_try_reap_events(ctx);
+
+ INIT_WORK(&ctx->exit_work, io_ring_exit_work);
+ /*
+ * Use system_unbound_wq to avoid spawning tons of event kworkers
+ * if we're exiting a ton of rings at the same time. It just adds
+ * noise and overhead, there's no discernable change in runtime
+ * over using system_wq.
+ */
+ queue_work(system_unbound_wq, &ctx->exit_work);
+}
+
+static int io_uring_release(struct inode *inode, struct file *file)
+{
+ struct io_ring_ctx *ctx = file->private_data;
+
+ file->private_data = NULL;
+ io_ring_ctx_wait_and_kill(ctx);
+ return 0;
+}
+
+struct io_task_cancel {
+ struct task_struct *task;
+ bool all;
+};
+
+static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
+{
+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+ struct io_task_cancel *cancel = data;
+
+ return io_match_task_safe(req, cancel->task, cancel->all);
+}
+
+static bool io_cancel_defer_files(struct io_ring_ctx *ctx,
+ struct task_struct *task, bool cancel_all)
+{
+ struct io_defer_entry *de;
+ LIST_HEAD(list);
+
+ spin_lock(&ctx->completion_lock);
+ list_for_each_entry_reverse(de, &ctx->defer_list, list) {
+ if (io_match_task_safe(de->req, task, cancel_all)) {
+ list_cut_position(&list, &ctx->defer_list, &de->list);
+ break;
+ }
+ }
+ spin_unlock(&ctx->completion_lock);
+ if (list_empty(&list))
+ return false;
+
+ while (!list_empty(&list)) {
+ de = list_first_entry(&list, struct io_defer_entry, list);
+ list_del_init(&de->list);
+ io_req_complete_failed(de->req, -ECANCELED);
+ kfree(de);
+ }
+ return true;
+}
+
+static bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx)
+{
+ struct io_tctx_node *node;
+ enum io_wq_cancel cret;
+ bool ret = false;
+
+ mutex_lock(&ctx->uring_lock);
+ list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
+ struct io_uring_task *tctx = node->task->io_uring;
+
+ /*
+ * io_wq will stay alive while we hold uring_lock, because it's
+ * killed after ctx nodes, which requires to take the lock.
+ */
+ if (!tctx || !tctx->io_wq)
+ continue;
+ cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true);
+ ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
+ }
+ mutex_unlock(&ctx->uring_lock);
+
+ return ret;
+}
+
+static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
+ struct task_struct *task,
+ bool cancel_all)
+{
+ struct io_task_cancel cancel = { .task = task, .all = cancel_all, };
+ struct io_uring_task *tctx = task ? task->io_uring : NULL;
+
+ while (1) {
+ enum io_wq_cancel cret;
+ bool ret = false;
+
+ if (!task) {
+ ret |= io_uring_try_cancel_iowq(ctx);
+ } else if (tctx && tctx->io_wq) {
+ /*
+ * Cancels requests of all rings, not only @ctx, but
+ * it's fine as the task is in exit/exec.
+ */
+ cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb,
+ &cancel, true);
+ ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
+ }
+
+ /* SQPOLL thread does its own polling */
+ if ((!(ctx->flags & IORING_SETUP_SQPOLL) && cancel_all) ||
+ (ctx->sq_data && ctx->sq_data->thread == current)) {
+ while (!list_empty_careful(&ctx->iopoll_list)) {
+ io_iopoll_try_reap_events(ctx);
+ ret = true;
+ }
+ }
+
+ ret |= io_cancel_defer_files(ctx, task, cancel_all);
+ ret |= io_poll_remove_all(ctx, task, cancel_all);
+ ret |= io_kill_timeouts(ctx, task, cancel_all);
+ if (task)
+ ret |= io_run_task_work();
+ if (!ret)
+ break;
+ cond_resched();
+ }
+}
+
+static int __io_uring_add_tctx_node(struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_tctx_node *node;
+ int ret;
+
+ if (unlikely(!tctx)) {
+ ret = io_uring_alloc_task_context(current, ctx);
+ if (unlikely(ret))
+ return ret;
+
+ tctx = current->io_uring;
+ if (ctx->iowq_limits_set) {
+ unsigned int limits[2] = { ctx->iowq_limits[0],
+ ctx->iowq_limits[1], };
+
+ ret = io_wq_max_workers(tctx->io_wq, limits);
+ if (ret)
+ return ret;
+ }
+ }
+ if (!xa_load(&tctx->xa, (unsigned long)ctx)) {
+ node = kmalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return -ENOMEM;
+ node->ctx = ctx;
+ node->task = current;
+
+ ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx,
+ node, GFP_KERNEL));
+ if (ret) {
+ kfree(node);
+ return ret;
+ }
+
+ mutex_lock(&ctx->uring_lock);
+ list_add(&node->ctx_node, &ctx->tctx_list);
+ mutex_unlock(&ctx->uring_lock);
+ }
+ tctx->last = ctx;
+ return 0;
+}
+
+/*
+ * Note that this task has used io_uring. We use it for cancelation purposes.
+ */
+static inline int io_uring_add_tctx_node(struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx = current->io_uring;
+
+ if (likely(tctx && tctx->last == ctx))
+ return 0;
+ return __io_uring_add_tctx_node(ctx);
+}
+
+/*
+ * Remove this io_uring_file -> task mapping.
+ */
+static void io_uring_del_tctx_node(unsigned long index)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_tctx_node *node;
+
+ if (!tctx)
+ return;
+ node = xa_erase(&tctx->xa, index);
+ if (!node)
+ return;
+
+ WARN_ON_ONCE(current != node->task);
+ WARN_ON_ONCE(list_empty(&node->ctx_node));
+
+ mutex_lock(&node->ctx->uring_lock);
+ list_del(&node->ctx_node);
+ mutex_unlock(&node->ctx->uring_lock);
+
+ if (tctx->last == node->ctx)
+ tctx->last = NULL;
+ kfree(node);
+}
+
+static void io_uring_clean_tctx(struct io_uring_task *tctx)
+{
+ struct io_wq *wq = tctx->io_wq;
+ struct io_tctx_node *node;
+ unsigned long index;
+
+ xa_for_each(&tctx->xa, index, node) {
+ io_uring_del_tctx_node(index);
+ cond_resched();
+ }
+ if (wq) {
+ /*
+ * Must be after io_uring_del_task_file() (removes nodes under
+ * uring_lock) to avoid race with io_uring_try_cancel_iowq().
+ */
+ io_wq_put_and_exit(wq);
+ tctx->io_wq = NULL;
+ }
+}
+
+static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked)
+{
+ if (tracked)
+ return atomic_read(&tctx->inflight_tracked);
+ return percpu_counter_sum(&tctx->inflight);
+}
+
+/*
+ * Find any io_uring ctx that this task has registered or done IO on, and cancel
+ * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation.
+ */
+static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ struct io_ring_ctx *ctx;
+ s64 inflight;
+ DEFINE_WAIT(wait);
+
+ WARN_ON_ONCE(sqd && sqd->thread != current);
+
+ if (!current->io_uring)
+ return;
+ if (tctx->io_wq)
+ io_wq_exit_start(tctx->io_wq);
+
+ atomic_inc(&tctx->in_idle);
+ do {
+ io_uring_drop_tctx_refs(current);
+ /* read completions before cancelations */
+ inflight = tctx_inflight(tctx, !cancel_all);
+ if (!inflight)
+ break;
+
+ if (!sqd) {
+ struct io_tctx_node *node;
+ unsigned long index;
+
+ xa_for_each(&tctx->xa, index, node) {
+ /* sqpoll task will cancel all its requests */
+ if (node->ctx->sq_data)
+ continue;
+ io_uring_try_cancel_requests(node->ctx, current,
+ cancel_all);
+ }
+ } else {
+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
+ io_uring_try_cancel_requests(ctx, current,
+ cancel_all);
+ }
+
+ prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE);
+ io_run_task_work();
+ io_uring_drop_tctx_refs(current);
+
+ /*
+ * If we've seen completions, retry without waiting. This
+ * avoids a race where a completion comes in before we did
+ * prepare_to_wait().
+ */
+ if (inflight == tctx_inflight(tctx, !cancel_all))
+ schedule();
+ finish_wait(&tctx->wait, &wait);
+ } while (1);
+
+ io_uring_clean_tctx(tctx);
+ if (cancel_all) {
+ /*
+ * We shouldn't run task_works after cancel, so just leave
+ * ->in_idle set for normal exit.
+ */
+ atomic_dec(&tctx->in_idle);
+ /* for exec all current's requests should be gone, kill tctx */
+ __io_uring_free(current);
+ }
+}
+
+void __io_uring_cancel(bool cancel_all)
+{
+ io_uring_cancel_generic(cancel_all, NULL);
+}
+
+static void *io_uring_validate_mmap_request(struct file *file,
+ loff_t pgoff, size_t sz)
+{
+ struct io_ring_ctx *ctx = file->private_data;
+ loff_t offset = pgoff << PAGE_SHIFT;
+ struct page *page;
+ void *ptr;
+
+ switch (offset) {
+ case IORING_OFF_SQ_RING:
+ case IORING_OFF_CQ_RING:
+ ptr = ctx->rings;
+ break;
+ case IORING_OFF_SQES:
+ ptr = ctx->sq_sqes;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ page = virt_to_head_page(ptr);
+ if (sz > page_size(page))
+ return ERR_PTR(-EINVAL);
+
+ return ptr;
+}
+
+#ifdef CONFIG_MMU
+
+static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ size_t sz = vma->vm_end - vma->vm_start;
+ unsigned long pfn;
+ void *ptr;
+
+ ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
+ if (IS_ERR(ptr))
+ return PTR_ERR(ptr);
+
+ pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
+ return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
+}
+
+#else /* !CONFIG_MMU */
+
+static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL;
+}
+
+static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
+{
+ return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE;
+}
+
+static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
+ unsigned long addr, unsigned long len,
+ unsigned long pgoff, unsigned long flags)
+{
+ void *ptr;
+
+ ptr = io_uring_validate_mmap_request(file, pgoff, len);
+ if (IS_ERR(ptr))
+ return PTR_ERR(ptr);
+
+ return (unsigned long) ptr;
+}
+
+#endif /* !CONFIG_MMU */
+
+static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
+{
+ DEFINE_WAIT(wait);
+
+ do {
+ if (!io_sqring_full(ctx))
+ break;
+ prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE);
+
+ if (!io_sqring_full(ctx))
+ break;
+ schedule();
+ } while (!signal_pending(current));
+
+ finish_wait(&ctx->sqo_sq_wait, &wait);
+ return 0;
+}
+
+static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz,
+ struct __kernel_timespec __user **ts,
+ const sigset_t __user **sig)
+{
+ struct io_uring_getevents_arg arg;
+
+ /*
+ * If EXT_ARG isn't set, then we have no timespec and the argp pointer
+ * is just a pointer to the sigset_t.
+ */
+ if (!(flags & IORING_ENTER_EXT_ARG)) {
+ *sig = (const sigset_t __user *) argp;
+ *ts = NULL;
+ return 0;
+ }
+
+ /*
+ * EXT_ARG is set - ensure we agree on the size of it and copy in our
+ * timespec and sigset_t pointers if good.
+ */
+ if (*argsz != sizeof(arg))
+ return -EINVAL;
+ if (copy_from_user(&arg, argp, sizeof(arg)))
+ return -EFAULT;
+ if (arg.pad)
+ return -EINVAL;
+ *sig = u64_to_user_ptr(arg.sigmask);
+ *argsz = arg.sigmask_sz;
+ *ts = u64_to_user_ptr(arg.ts);
+ return 0;
+}
+
+SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
+ u32, min_complete, u32, flags, const void __user *, argp,
+ size_t, argsz)
+{
+ struct io_ring_ctx *ctx;
+ int submitted = 0;
+ struct fd f;
+ long ret;
+
+ io_run_task_work();
+
+ if (unlikely(flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
+ IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG)))
+ return -EINVAL;
+
+ f = fdget(fd);
+ if (unlikely(!f.file))
+ return -EBADF;
+
+ ret = -EOPNOTSUPP;
+ if (unlikely(f.file->f_op != &io_uring_fops))
+ goto out_fput;
+
+ ret = -ENXIO;
+ ctx = f.file->private_data;
+ if (unlikely(!percpu_ref_tryget(&ctx->refs)))
+ goto out_fput;
+
+ ret = -EBADFD;
+ if (unlikely(ctx->flags & IORING_SETUP_R_DISABLED))
+ goto out;
+
+ /*
+ * For SQ polling, the thread will do all submissions and completions.
+ * Just return the requested submit count, and wake the thread if
+ * we were asked to.
+ */
+ ret = 0;
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
+ io_cqring_overflow_flush(ctx);
+
+ if (unlikely(ctx->sq_data->thread == NULL)) {
+ ret = -EOWNERDEAD;
+ goto out;
+ }
+ if (flags & IORING_ENTER_SQ_WAKEUP)
+ wake_up(&ctx->sq_data->wait);
+ if (flags & IORING_ENTER_SQ_WAIT) {
+ ret = io_sqpoll_wait_sq(ctx);
+ if (ret)
+ goto out;
+ }
+ submitted = to_submit;
+ } else if (to_submit) {
+ ret = io_uring_add_tctx_node(ctx);
+ if (unlikely(ret))
+ goto out;
+ mutex_lock(&ctx->uring_lock);
+ submitted = io_submit_sqes(ctx, to_submit);
+ mutex_unlock(&ctx->uring_lock);
+
+ if (submitted != to_submit)
+ goto out;
+ }
+ if (flags & IORING_ENTER_GETEVENTS) {
+ const sigset_t __user *sig;
+ struct __kernel_timespec __user *ts;
+
+ ret = io_get_ext_arg(flags, argp, &argsz, &ts, &sig);
+ if (unlikely(ret))
+ goto out;
+
+ min_complete = min(min_complete, ctx->cq_entries);
+
+ /*
+ * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
+ * space applications don't need to do io completion events
+ * polling again, they can rely on io_sq_thread to do polling
+ * work, which can reduce cpu usage and uring_lock contention.
+ */
+ if (ctx->flags & IORING_SETUP_IOPOLL &&
+ !(ctx->flags & IORING_SETUP_SQPOLL)) {
+ ret = io_iopoll_check(ctx, min_complete);
+ } else {
+ ret = io_cqring_wait(ctx, min_complete, sig, argsz, ts);
+ }
+ }
+
+out:
+ percpu_ref_put(&ctx->refs);
+out_fput:
+ fdput(f);
+ return submitted ? submitted : ret;
+}
+
+#ifdef CONFIG_PROC_FS
+static int io_uring_show_cred(struct seq_file *m, unsigned int id,
+ const struct cred *cred)
+{
+ struct user_namespace *uns = seq_user_ns(m);
+ struct group_info *gi;
+ kernel_cap_t cap;
+ unsigned __capi;
+ int g;
+
+ seq_printf(m, "%5d\n", id);
+ seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
+ seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
+ seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
+ seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
+ seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
+ seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
+ seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
+ seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
+ seq_puts(m, "\n\tGroups:\t");
+ gi = cred->group_info;
+ for (g = 0; g < gi->ngroups; g++) {
+ seq_put_decimal_ull(m, g ? " " : "",
+ from_kgid_munged(uns, gi->gid[g]));
+ }
+ seq_puts(m, "\n\tCapEff:\t");
+ cap = cred->cap_effective;
+ CAP_FOR_EACH_U32(__capi)
+ seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
+ seq_putc(m, '\n');
+ return 0;
+}
+
+static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
+{
+ struct io_sq_data *sq = NULL;
+ bool has_lock;
+ int i;
+
+ /*
+ * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
+ * since fdinfo case grabs it in the opposite direction of normal use
+ * cases. If we fail to get the lock, we just don't iterate any
+ * structures that could be going away outside the io_uring mutex.
+ */
+ has_lock = mutex_trylock(&ctx->uring_lock);
+
+ if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
+ sq = ctx->sq_data;
+ if (!sq->thread)
+ sq = NULL;
+ }
+
+ seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
+ seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
+ seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
+ for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
+ struct file *f = io_file_from_index(ctx, i);
+
+ if (f)
+ seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
+ else
+ seq_printf(m, "%5u: <none>\n", i);
+ }
+ seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
+ for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
+ struct io_mapped_ubuf *buf = ctx->user_bufs[i];
+ unsigned int len = buf->ubuf_end - buf->ubuf;
+
+ seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len);
+ }
+ if (has_lock && !xa_empty(&ctx->personalities)) {
+ unsigned long index;
+ const struct cred *cred;
+
+ seq_printf(m, "Personalities:\n");
+ xa_for_each(&ctx->personalities, index, cred)
+ io_uring_show_cred(m, index, cred);
+ }
+ seq_printf(m, "PollList:\n");
+ spin_lock(&ctx->completion_lock);
+ for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
+ struct hlist_head *list = &ctx->cancel_hash[i];
+ struct io_kiocb *req;
+
+ hlist_for_each_entry(req, list, hash_node)
+ seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
+ req->task->task_works != NULL);
+ }
+ spin_unlock(&ctx->completion_lock);
+ if (has_lock)
+ mutex_unlock(&ctx->uring_lock);
+}
+
+static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
+{
+ struct io_ring_ctx *ctx = f->private_data;
+
+ if (percpu_ref_tryget(&ctx->refs)) {
+ __io_uring_show_fdinfo(ctx, m);
+ percpu_ref_put(&ctx->refs);
+ }
+}
+#endif
+
+static const struct file_operations io_uring_fops = {
+ .release = io_uring_release,
+ .mmap = io_uring_mmap,
+#ifndef CONFIG_MMU
+ .get_unmapped_area = io_uring_nommu_get_unmapped_area,
+ .mmap_capabilities = io_uring_nommu_mmap_capabilities,
+#endif
+ .poll = io_uring_poll,
+#ifdef CONFIG_PROC_FS
+ .show_fdinfo = io_uring_show_fdinfo,
+#endif
+};
+
+static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
+ struct io_uring_params *p)
+{
+ struct io_rings *rings;
+ size_t size, sq_array_offset;
+
+ /* make sure these are sane, as we already accounted them */
+ ctx->sq_entries = p->sq_entries;
+ ctx->cq_entries = p->cq_entries;
+
+ size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
+ if (size == SIZE_MAX)
+ return -EOVERFLOW;
+
+ rings = io_mem_alloc(size);
+ if (!rings)
+ return -ENOMEM;
+
+ ctx->rings = rings;
+ ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
+ rings->sq_ring_mask = p->sq_entries - 1;
+ rings->cq_ring_mask = p->cq_entries - 1;
+ rings->sq_ring_entries = p->sq_entries;
+ rings->cq_ring_entries = p->cq_entries;
+
+ size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
+ if (size == SIZE_MAX) {
+ io_mem_free(ctx->rings);
+ ctx->rings = NULL;
+ return -EOVERFLOW;
+ }
+
+ ctx->sq_sqes = io_mem_alloc(size);
+ if (!ctx->sq_sqes) {
+ io_mem_free(ctx->rings);
+ ctx->rings = NULL;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
+{
+ int ret, fd;
+
+ fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
+ if (fd < 0)
+ return fd;
+
+ ret = io_uring_add_tctx_node(ctx);
+ if (ret) {
+ put_unused_fd(fd);
+ return ret;
+ }
+ fd_install(fd, file);
+ return fd;
+}
+
+/*
+ * Allocate an anonymous fd, this is what constitutes the application
+ * visible backing of an io_uring instance. The application mmaps this
+ * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
+ * we have to tie this fd to a socket for file garbage collection purposes.
+ */
+static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
+{
+ struct file *file;
+#if defined(CONFIG_UNIX)
+ int ret;
+
+ ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
+ &ctx->ring_sock);
+ if (ret)
+ return ERR_PTR(ret);
+#endif
+
+ file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
+ O_RDWR | O_CLOEXEC);
+#if defined(CONFIG_UNIX)
+ if (IS_ERR(file)) {
+ sock_release(ctx->ring_sock);
+ ctx->ring_sock = NULL;
+ } else {
+ ctx->ring_sock->file = file;
+ }
+#endif
+ return file;
+}
+
+static int io_uring_create(unsigned entries, struct io_uring_params *p,
+ struct io_uring_params __user *params)
+{
+ struct io_ring_ctx *ctx;
+ struct file *file;
+ int ret;
+
+ if (!entries)
+ return -EINVAL;
+ if (entries > IORING_MAX_ENTRIES) {
+ if (!(p->flags & IORING_SETUP_CLAMP))
+ return -EINVAL;
+ entries = IORING_MAX_ENTRIES;
+ }
+
+ /*
+ * Use twice as many entries for the CQ ring. It's possible for the
+ * application to drive a higher depth than the size of the SQ ring,
+ * since the sqes are only used at submission time. This allows for
+ * some flexibility in overcommitting a bit. If the application has
+ * set IORING_SETUP_CQSIZE, it will have passed in the desired number
+ * of CQ ring entries manually.
+ */
+ p->sq_entries = roundup_pow_of_two(entries);
+ if (p->flags & IORING_SETUP_CQSIZE) {
+ /*
+ * If IORING_SETUP_CQSIZE is set, we do the same roundup
+ * to a power-of-two, if it isn't already. We do NOT impose
+ * any cq vs sq ring sizing.
+ */
+ if (!p->cq_entries)
+ return -EINVAL;
+ if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
+ if (!(p->flags & IORING_SETUP_CLAMP))
+ return -EINVAL;
+ p->cq_entries = IORING_MAX_CQ_ENTRIES;
+ }
+ p->cq_entries = roundup_pow_of_two(p->cq_entries);
+ if (p->cq_entries < p->sq_entries)
+ return -EINVAL;
+ } else {
+ p->cq_entries = 2 * p->sq_entries;
+ }
+
+ ctx = io_ring_ctx_alloc(p);
+ if (!ctx)
+ return -ENOMEM;
+ ctx->compat = in_compat_syscall();
+ if (!capable(CAP_IPC_LOCK))
+ ctx->user = get_uid(current_user());
+
+ /*
+ * This is just grabbed for accounting purposes. When a process exits,
+ * the mm is exited and dropped before the files, hence we need to hang
+ * on to this mm purely for the purposes of being able to unaccount
+ * memory (locked/pinned vm). It's not used for anything else.
+ */
+ mmgrab(current->mm);
+ ctx->mm_account = current->mm;
+
+ ret = io_allocate_scq_urings(ctx, p);
+ if (ret)
+ goto err;
+
+ ret = io_sq_offload_create(ctx, p);
+ if (ret)
+ goto err;
+ /* always set a rsrc node */
+ ret = io_rsrc_node_switch_start(ctx);
+ if (ret)
+ goto err;
+ io_rsrc_node_switch(ctx, NULL);
+
+ memset(&p->sq_off, 0, sizeof(p->sq_off));
+ p->sq_off.head = offsetof(struct io_rings, sq.head);
+ p->sq_off.tail = offsetof(struct io_rings, sq.tail);
+ p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
+ p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
+ p->sq_off.flags = offsetof(struct io_rings, sq_flags);
+ p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
+ p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
+
+ memset(&p->cq_off, 0, sizeof(p->cq_off));
+ p->cq_off.head = offsetof(struct io_rings, cq.head);
+ p->cq_off.tail = offsetof(struct io_rings, cq.tail);
+ p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
+ p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
+ p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
+ p->cq_off.cqes = offsetof(struct io_rings, cqes);
+ p->cq_off.flags = offsetof(struct io_rings, cq_flags);
+
+ p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
+ IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
+ IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL |
+ IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED |
+ IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS |
+ IORING_FEAT_RSRC_TAGS;
+
+ if (copy_to_user(params, p, sizeof(*p))) {
+ ret = -EFAULT;
+ goto err;
+ }
+
+ file = io_uring_get_file(ctx);
+ if (IS_ERR(file)) {
+ ret = PTR_ERR(file);
+ goto err;
+ }
+
+ /*
+ * Install ring fd as the very last thing, so we don't risk someone
+ * having closed it before we finish setup
+ */
+ ret = io_uring_install_fd(ctx, file);
+ if (ret < 0) {
+ /* fput will clean it up */
+ fput(file);
+ return ret;
+ }
+
+ trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
+ return ret;
+err:
+ io_ring_ctx_wait_and_kill(ctx);
+ return ret;
+}
+
+/*
+ * Sets up an aio uring context, and returns the fd. Applications asks for a
+ * ring size, we return the actual sq/cq ring sizes (among other things) in the
+ * params structure passed in.
+ */
+static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
+{
+ struct io_uring_params p;
+ int i;
+
+ if (copy_from_user(&p, params, sizeof(p)))
+ return -EFAULT;
+ for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
+ if (p.resv[i])
+ return -EINVAL;
+ }
+
+ if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
+ IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
+ IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
+ IORING_SETUP_R_DISABLED))
+ return -EINVAL;
+
+ return io_uring_create(entries, &p, params);
+}
+
+SYSCALL_DEFINE2(io_uring_setup, u32, entries,
+ struct io_uring_params __user *, params)
+{
+ return io_uring_setup(entries, params);
+}
+
+static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
+{
+ struct io_uring_probe *p;
+ size_t size;
+ int i, ret;
+
+ size = struct_size(p, ops, nr_args);
+ if (size == SIZE_MAX)
+ return -EOVERFLOW;
+ p = kzalloc(size, GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ ret = -EFAULT;
+ if (copy_from_user(p, arg, size))
+ goto out;
+ ret = -EINVAL;
+ if (memchr_inv(p, 0, size))
+ goto out;
+
+ p->last_op = IORING_OP_LAST - 1;
+ if (nr_args > IORING_OP_LAST)
+ nr_args = IORING_OP_LAST;
+
+ for (i = 0; i < nr_args; i++) {
+ p->ops[i].op = i;
+ if (!io_op_defs[i].not_supported)
+ p->ops[i].flags = IO_URING_OP_SUPPORTED;
+ }
+ p->ops_len = i;
+
+ ret = 0;
+ if (copy_to_user(arg, p, size))
+ ret = -EFAULT;
+out:
+ kfree(p);
+ return ret;
+}
+
+static int io_register_personality(struct io_ring_ctx *ctx)
+{
+ const struct cred *creds;
+ u32 id;
+ int ret;
+
+ creds = get_current_cred();
+
+ ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds,
+ XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL);
+ if (ret < 0) {
+ put_cred(creds);
+ return ret;
+ }
+ return id;
+}
+
+static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned int nr_args)
+{
+ struct io_uring_restriction *res;
+ size_t size;
+ int i, ret;
+
+ /* Restrictions allowed only if rings started disabled */
+ if (!(ctx->flags & IORING_SETUP_R_DISABLED))
+ return -EBADFD;
+
+ /* We allow only a single restrictions registration */
+ if (ctx->restrictions.registered)
+ return -EBUSY;
+
+ if (!arg || nr_args > IORING_MAX_RESTRICTIONS)
+ return -EINVAL;
+
+ size = array_size(nr_args, sizeof(*res));
+ if (size == SIZE_MAX)
+ return -EOVERFLOW;
+
+ res = memdup_user(arg, size);
+ if (IS_ERR(res))
+ return PTR_ERR(res);
+
+ ret = 0;
+
+ for (i = 0; i < nr_args; i++) {
+ switch (res[i].opcode) {
+ case IORING_RESTRICTION_REGISTER_OP:
+ if (res[i].register_op >= IORING_REGISTER_LAST) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ __set_bit(res[i].register_op,
+ ctx->restrictions.register_op);
+ break;
+ case IORING_RESTRICTION_SQE_OP:
+ if (res[i].sqe_op >= IORING_OP_LAST) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ __set_bit(res[i].sqe_op, ctx->restrictions.sqe_op);
+ break;
+ case IORING_RESTRICTION_SQE_FLAGS_ALLOWED:
+ ctx->restrictions.sqe_flags_allowed = res[i].sqe_flags;
+ break;
+ case IORING_RESTRICTION_SQE_FLAGS_REQUIRED:
+ ctx->restrictions.sqe_flags_required = res[i].sqe_flags;
+ break;
+ default:
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+out:
+ /* Reset all restrictions if an error happened */
+ if (ret != 0)
+ memset(&ctx->restrictions, 0, sizeof(ctx->restrictions));
+ else
+ ctx->restrictions.registered = true;
+
+ kfree(res);
+ return ret;
+}
+
+static int io_register_enable_rings(struct io_ring_ctx *ctx)
+{
+ if (!(ctx->flags & IORING_SETUP_R_DISABLED))
+ return -EBADFD;
+
+ if (ctx->restrictions.registered)
+ ctx->restricted = 1;
+
+ ctx->flags &= ~IORING_SETUP_R_DISABLED;
+ if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait))
+ wake_up(&ctx->sq_data->wait);
+ return 0;
+}
+
+static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type,
+ struct io_uring_rsrc_update2 *up,
+ unsigned nr_args)
+{
+ __u32 tmp;
+ int err;
+
+ if (check_add_overflow(up->offset, nr_args, &tmp))
+ return -EOVERFLOW;
+ err = io_rsrc_node_switch_start(ctx);
+ if (err)
+ return err;
+
+ switch (type) {
+ case IORING_RSRC_FILE:
+ return __io_sqe_files_update(ctx, up, nr_args);
+ case IORING_RSRC_BUFFER:
+ return __io_sqe_buffers_update(ctx, up, nr_args);
+ }
+ return -EINVAL;
+}
+
+static int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned nr_args)
+{
+ struct io_uring_rsrc_update2 up;
+
+ if (!nr_args)
+ return -EINVAL;
+ memset(&up, 0, sizeof(up));
+ if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update)))
+ return -EFAULT;
+ if (up.resv || up.resv2)
+ return -EINVAL;
+ return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args);
+}
+
+static int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned size, unsigned type)
+{
+ struct io_uring_rsrc_update2 up;
+
+ if (size != sizeof(up))
+ return -EINVAL;
+ if (copy_from_user(&up, arg, sizeof(up)))
+ return -EFAULT;
+ if (!up.nr || up.resv || up.resv2)
+ return -EINVAL;
+ return __io_register_rsrc_update(ctx, type, &up, up.nr);
+}
+
+static int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned int size, unsigned int type)
+{
+ struct io_uring_rsrc_register rr;
+
+ /* keep it extendible */
+ if (size != sizeof(rr))
+ return -EINVAL;
+
+ memset(&rr, 0, sizeof(rr));
+ if (copy_from_user(&rr, arg, size))
+ return -EFAULT;
+ if (!rr.nr || rr.resv || rr.resv2)
+ return -EINVAL;
+
+ switch (type) {
+ case IORING_RSRC_FILE:
+ return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data),
+ rr.nr, u64_to_user_ptr(rr.tags));
+ case IORING_RSRC_BUFFER:
+ return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data),
+ rr.nr, u64_to_user_ptr(rr.tags));
+ }
+ return -EINVAL;
+}
+
+static int io_register_iowq_aff(struct io_ring_ctx *ctx, void __user *arg,
+ unsigned len)
+{
+ struct io_uring_task *tctx = current->io_uring;
+ cpumask_var_t new_mask;
+ int ret;
+
+ if (!tctx || !tctx->io_wq)
+ return -EINVAL;
+
+ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ cpumask_clear(new_mask);
+ if (len > cpumask_size())
+ len = cpumask_size();
+
+#ifdef CONFIG_COMPAT
+ if (in_compat_syscall()) {
+ ret = compat_get_bitmap(cpumask_bits(new_mask),
+ (const compat_ulong_t __user *)arg,
+ len * 8 /* CHAR_BIT */);
+ } else {
+ ret = copy_from_user(new_mask, arg, len);
+ }
+#else
+ ret = copy_from_user(new_mask, arg, len);
+#endif
+
+ if (ret) {
+ free_cpumask_var(new_mask);
+ return -EFAULT;
+ }
+
+ ret = io_wq_cpu_affinity(tctx->io_wq, new_mask);
+ free_cpumask_var(new_mask);
+ return ret;
+}
+
+static int io_unregister_iowq_aff(struct io_ring_ctx *ctx)
+{
+ struct io_uring_task *tctx = current->io_uring;
+
+ if (!tctx || !tctx->io_wq)
+ return -EINVAL;
+
+ return io_wq_cpu_affinity(tctx->io_wq, NULL);
+}
+
+static int io_register_iowq_max_workers(struct io_ring_ctx *ctx,
+ void __user *arg)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_tctx_node *node;
+ struct io_uring_task *tctx = NULL;
+ struct io_sq_data *sqd = NULL;
+ __u32 new_count[2];
+ int i, ret;
+
+ if (copy_from_user(new_count, arg, sizeof(new_count)))
+ return -EFAULT;
+ for (i = 0; i < ARRAY_SIZE(new_count); i++)
+ if (new_count[i] > INT_MAX)
+ return -EINVAL;
+
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
+ sqd = ctx->sq_data;
+ if (sqd) {
+ /*
+ * Observe the correct sqd->lock -> ctx->uring_lock
+ * ordering. Fine to drop uring_lock here, we hold
+ * a ref to the ctx.
+ */
+ refcount_inc(&sqd->refs);
+ mutex_unlock(&ctx->uring_lock);
+ mutex_lock(&sqd->lock);
+ mutex_lock(&ctx->uring_lock);
+ if (sqd->thread)
+ tctx = sqd->thread->io_uring;
+ }
+ } else {
+ tctx = current->io_uring;
+ }
+
+ BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits));
+
+ for (i = 0; i < ARRAY_SIZE(new_count); i++)
+ if (new_count[i])
+ ctx->iowq_limits[i] = new_count[i];
+ ctx->iowq_limits_set = true;
+
+ ret = -EINVAL;
+ if (tctx && tctx->io_wq) {
+ ret = io_wq_max_workers(tctx->io_wq, new_count);
+ if (ret)
+ goto err;
+ } else {
+ memset(new_count, 0, sizeof(new_count));
+ }
+
+ if (sqd) {
+ mutex_unlock(&sqd->lock);
+ io_put_sq_data(sqd);
+ }
+
+ if (copy_to_user(arg, new_count, sizeof(new_count)))
+ return -EFAULT;
+
+ /* that's it for SQPOLL, only the SQPOLL task creates requests */
+ if (sqd)
+ return 0;
+
+ /* now propagate the restriction to all registered users */
+ list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
+ struct io_uring_task *tctx = node->task->io_uring;
+
+ if (WARN_ON_ONCE(!tctx->io_wq))
+ continue;
+
+ for (i = 0; i < ARRAY_SIZE(new_count); i++)
+ new_count[i] = ctx->iowq_limits[i];
+ /* ignore errors, it always returns zero anyway */
+ (void)io_wq_max_workers(tctx->io_wq, new_count);
+ }
+ return 0;
+err:
+ if (sqd) {
+ mutex_unlock(&sqd->lock);
+ io_put_sq_data(sqd);
+ }
+ return ret;
+}
+
+static bool io_register_op_must_quiesce(int op)
+{
+ switch (op) {
+ case IORING_REGISTER_BUFFERS:
+ case IORING_UNREGISTER_BUFFERS:
+ case IORING_REGISTER_FILES:
+ case IORING_UNREGISTER_FILES:
+ case IORING_REGISTER_FILES_UPDATE:
+ case IORING_REGISTER_PROBE:
+ case IORING_REGISTER_PERSONALITY:
+ case IORING_UNREGISTER_PERSONALITY:
+ case IORING_REGISTER_FILES2:
+ case IORING_REGISTER_FILES_UPDATE2:
+ case IORING_REGISTER_BUFFERS2:
+ case IORING_REGISTER_BUFFERS_UPDATE:
+ case IORING_REGISTER_IOWQ_AFF:
+ case IORING_UNREGISTER_IOWQ_AFF:
+ case IORING_REGISTER_IOWQ_MAX_WORKERS:
+ return false;
+ default:
+ return true;
+ }
+}
+
+static int io_ctx_quiesce(struct io_ring_ctx *ctx)
+{
+ long ret;
+
+ percpu_ref_kill(&ctx->refs);
+
+ /*
+ * Drop uring mutex before waiting for references to exit. If another
+ * thread is currently inside io_uring_enter() it might need to grab the
+ * uring_lock to make progress. If we hold it here across the drain
+ * wait, then we can deadlock. It's safe to drop the mutex here, since
+ * no new references will come in after we've killed the percpu ref.
+ */
+ mutex_unlock(&ctx->uring_lock);
+ do {
+ ret = wait_for_completion_interruptible(&ctx->ref_comp);
+ if (!ret)
+ break;
+ ret = io_run_task_work_sig();
+ } while (ret >= 0);
+ mutex_lock(&ctx->uring_lock);
+
+ if (ret)
+ io_refs_resurrect(&ctx->refs, &ctx->ref_comp);
+ return ret;
+}
+
+static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
+ void __user *arg, unsigned nr_args)
+ __releases(ctx->uring_lock)
+ __acquires(ctx->uring_lock)
+{
+ int ret;
+
+ /*
+ * We're inside the ring mutex, if the ref is already dying, then
+ * someone else killed the ctx or is already going through
+ * io_uring_register().
+ */
+ if (percpu_ref_is_dying(&ctx->refs))
+ return -ENXIO;
+
+ if (ctx->restricted) {
+ if (opcode >= IORING_REGISTER_LAST)
+ return -EINVAL;
+ opcode = array_index_nospec(opcode, IORING_REGISTER_LAST);
+ if (!test_bit(opcode, ctx->restrictions.register_op))
+ return -EACCES;
+ }
+
+ if (io_register_op_must_quiesce(opcode)) {
+ ret = io_ctx_quiesce(ctx);
+ if (ret)
+ return ret;
+ }
+
+ switch (opcode) {
+ case IORING_REGISTER_BUFFERS:
+ ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL);
+ break;
+ case IORING_UNREGISTER_BUFFERS:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_sqe_buffers_unregister(ctx);
+ break;
+ case IORING_REGISTER_FILES:
+ ret = io_sqe_files_register(ctx, arg, nr_args, NULL);
+ break;
+ case IORING_UNREGISTER_FILES:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_sqe_files_unregister(ctx);
+ break;
+ case IORING_REGISTER_FILES_UPDATE:
+ ret = io_register_files_update(ctx, arg, nr_args);
+ break;
+ case IORING_REGISTER_EVENTFD:
+ case IORING_REGISTER_EVENTFD_ASYNC:
+ ret = -EINVAL;
+ if (nr_args != 1)
+ break;
+ ret = io_eventfd_register(ctx, arg);
+ if (ret)
+ break;
+ if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
+ ctx->eventfd_async = 1;
+ else
+ ctx->eventfd_async = 0;
+ break;
+ case IORING_UNREGISTER_EVENTFD:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_eventfd_unregister(ctx);
+ break;
+ case IORING_REGISTER_PROBE:
+ ret = -EINVAL;
+ if (!arg || nr_args > 256)
+ break;
+ ret = io_probe(ctx, arg, nr_args);
+ break;
+ case IORING_REGISTER_PERSONALITY:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_register_personality(ctx);
+ break;
+ case IORING_UNREGISTER_PERSONALITY:
+ ret = -EINVAL;
+ if (arg)
+ break;
+ ret = io_unregister_personality(ctx, nr_args);
+ break;
+ case IORING_REGISTER_ENABLE_RINGS:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_register_enable_rings(ctx);
+ break;
+ case IORING_REGISTER_RESTRICTIONS:
+ ret = io_register_restrictions(ctx, arg, nr_args);
+ break;
+ case IORING_REGISTER_FILES2:
+ ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE);
+ break;
+ case IORING_REGISTER_FILES_UPDATE2:
+ ret = io_register_rsrc_update(ctx, arg, nr_args,
+ IORING_RSRC_FILE);
+ break;
+ case IORING_REGISTER_BUFFERS2:
+ ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER);
+ break;
+ case IORING_REGISTER_BUFFERS_UPDATE:
+ ret = io_register_rsrc_update(ctx, arg, nr_args,
+ IORING_RSRC_BUFFER);
+ break;
+ case IORING_REGISTER_IOWQ_AFF:
+ ret = -EINVAL;
+ if (!arg || !nr_args)
+ break;
+ ret = io_register_iowq_aff(ctx, arg, nr_args);
+ break;
+ case IORING_UNREGISTER_IOWQ_AFF:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_unregister_iowq_aff(ctx);
+ break;
+ case IORING_REGISTER_IOWQ_MAX_WORKERS:
+ ret = -EINVAL;
+ if (!arg || nr_args != 2)
+ break;
+ ret = io_register_iowq_max_workers(ctx, arg);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ if (io_register_op_must_quiesce(opcode)) {
+ /* bring the ctx back to life */
+ percpu_ref_reinit(&ctx->refs);
+ reinit_completion(&ctx->ref_comp);
+ }
+ return ret;
+}
+
+SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
+ void __user *, arg, unsigned int, nr_args)
+{
+ struct io_ring_ctx *ctx;
+ long ret = -EBADF;
+ struct fd f;
+
+ f = fdget(fd);
+ if (!f.file)
+ return -EBADF;
+
+ ret = -EOPNOTSUPP;
+ if (f.file->f_op != &io_uring_fops)
+ goto out_fput;
+
+ ctx = f.file->private_data;
+
+ io_run_task_work();
+
+ mutex_lock(&ctx->uring_lock);
+ ret = __io_uring_register(ctx, opcode, arg, nr_args);
+ mutex_unlock(&ctx->uring_lock);
+ trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs,
+ ctx->cq_ev_fd != NULL, ret);
+out_fput:
+ fdput(f);
+ return ret;
+}
+
+static int __init io_uring_init(void)
+{
+#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
+ BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
+ BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
+} while (0)
+
+#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
+ __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
+ BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
+ BUILD_BUG_SQE_ELEM(0, __u8, opcode);
+ BUILD_BUG_SQE_ELEM(1, __u8, flags);
+ BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
+ BUILD_BUG_SQE_ELEM(4, __s32, fd);
+ BUILD_BUG_SQE_ELEM(8, __u64, off);
+ BUILD_BUG_SQE_ELEM(8, __u64, addr2);
+ BUILD_BUG_SQE_ELEM(16, __u64, addr);
+ BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
+ BUILD_BUG_SQE_ELEM(24, __u32, len);
+ BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
+ BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
+ BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
+ BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events);
+ BUILD_BUG_SQE_ELEM(28, __u32, poll32_events);
+ BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
+ BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
+ BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
+ BUILD_BUG_SQE_ELEM(32, __u64, user_data);
+ BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
+ BUILD_BUG_SQE_ELEM(40, __u16, buf_group);
+ BUILD_BUG_SQE_ELEM(42, __u16, personality);
+ BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
+ BUILD_BUG_SQE_ELEM(44, __u32, file_index);
+
+ BUILD_BUG_ON(sizeof(struct io_uring_files_update) !=
+ sizeof(struct io_uring_rsrc_update));
+ BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update) >
+ sizeof(struct io_uring_rsrc_update2));
+
+ /* ->buf_index is u16 */
+ BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16));
+
+ /* should fit into one byte */
+ BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8));
+
+ BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
+ BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof(int));
+
+ req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC |
+ SLAB_ACCOUNT);
+ return 0;
+};
+__initcall(io_uring_init);
