UPSTREAM: io_uring: update kiocb->ki_pos at execution time
commit d34e1e5b396a0dbaa4a29b7138df662cfb9d8e8e upstream.
Update kiocb->ki_pos at execution time rather than in io_prep_rw().
io_prep_rw() happens before the job is enqueued to a worker and so the
offset might be read multiple times before being executed once.
Ensures that the file position in a set of _linked_ SQEs will be only
obtained after earlier SQEs have completed, and so will include their
incremented file position.
Change-Id: I3c5abbf6a337ec1958fd6600c5feb44fb61a5772
Signed-off-by: Dylan Yudaken <[email protected]>
Reviewed-by: Pavel Begunkov <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Bug: 268174392
(cherry picked from commit ea528ecac3ae58d8197871b29748eefca7d46be8)
Signed-off-by: Greg Kroah-Hartman <[email protected]>
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 7b26c0c..ad58603 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2929,14 +2929,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
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));
@@ -3018,6 +3010,20 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
}
}
+static inline void io_kiocb_update_pos(struct io_kiocb *req)
+{
+ struct kiocb *kiocb = &req->rw.kiocb;
+
+ if (kiocb->ki_pos == -1) {
+ if (!(req->file->f_mode & FMODE_STREAM)) {
+ req->flags |= REQ_F_CUR_POS;
+ kiocb->ki_pos = req->file->f_pos;
+ } else {
+ kiocb->ki_pos = 0;
+ }
+ }
+}
+
static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
unsigned int issue_flags)
{
@@ -3573,6 +3579,8 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
return ret ?: -EAGAIN;
}
+ io_kiocb_update_pos(req);
+
ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), req->result);
if (unlikely(ret)) {
kfree(iovec);
@@ -3707,6 +3715,8 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
(req->flags & REQ_F_ISREG))
goto copy_iov;
+ io_kiocb_update_pos(req);
+
ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result);
if (unlikely(ret))
goto out_free;
