libceph: preallocate message data items
Currently message data items are allocated with ceph_msg_data_create()
in setup_request_data() inside send_request(). send_request() has never
been allowed to fail, so each allocation is followed by a BUG_ON:
data = ceph_msg_data_create(...);
BUG_ON(!data);
It's been this way since support for multiple message data items was
added in commit 6644ed7b7e04 ("libceph: make message data be a pointer")
in 3.10.
There is no reason to delay the allocation of message data items until
the last possible moment and we certainly don't need a linked list of
them as they are only ever appended to the end and never erased. Make
ceph_msg_new2() take max_data_items and adapt the rest of the code.
Reported-by: Jerry Lee <[email protected]>
Signed-off-by: Ilya Dryomov <[email protected]>
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index fc2b449..800a212 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -82,22 +82,6 @@ enum ceph_msg_data_type {
CEPH_MSG_DATA_BVECS, /* data source/destination is a bio_vec array */
};
-static __inline__ bool ceph_msg_data_type_valid(enum ceph_msg_data_type type)
-{
- switch (type) {
- case CEPH_MSG_DATA_NONE:
- case CEPH_MSG_DATA_PAGES:
- case CEPH_MSG_DATA_PAGELIST:
-#ifdef CONFIG_BLOCK
- case CEPH_MSG_DATA_BIO:
-#endif /* CONFIG_BLOCK */
- case CEPH_MSG_DATA_BVECS:
- return true;
- default:
- return false;
- }
-}
-
#ifdef CONFIG_BLOCK
struct ceph_bio_iter {
@@ -181,7 +165,6 @@ struct ceph_bvec_iter {
} while (0)
struct ceph_msg_data {
- struct list_head links; /* ceph_msg->data */
enum ceph_msg_data_type type;
union {
#ifdef CONFIG_BLOCK
@@ -202,7 +185,6 @@ struct ceph_msg_data {
struct ceph_msg_data_cursor {
size_t total_resid; /* across all data items */
- struct list_head *data_head; /* = &ceph_msg->data */
struct ceph_msg_data *data; /* current data item */
size_t resid; /* bytes not yet consumed */
@@ -240,7 +222,9 @@ struct ceph_msg {
struct ceph_buffer *middle;
size_t data_length;
- struct list_head data;
+ struct ceph_msg_data *data;
+ int num_data_items;
+ int max_data_items;
struct ceph_msg_data_cursor cursor;
struct ceph_connection *con;
@@ -381,6 +365,8 @@ void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
struct ceph_bvec_iter *bvec_pos);
+struct ceph_msg *ceph_msg_new2(int type, int front_len, int max_data_items,
+ gfp_t flags, bool can_fail);
extern struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
bool can_fail);
diff --git a/include/linux/ceph/msgpool.h b/include/linux/ceph/msgpool.h
index 76c98a5..729cdf7 100644
--- a/include/linux/ceph/msgpool.h
+++ b/include/linux/ceph/msgpool.h
@@ -13,14 +13,15 @@ struct ceph_msgpool {
mempool_t *pool;
int type; /* preallocated message type */
int front_len; /* preallocated payload size */
+ int max_data_items;
};
-extern int ceph_msgpool_init(struct ceph_msgpool *pool, int type,
- int front_len, int size, bool blocking,
- const char *name);
+int ceph_msgpool_init(struct ceph_msgpool *pool, int type,
+ int front_len, int max_data_items, int size,
+ const char *name);
extern void ceph_msgpool_destroy(struct ceph_msgpool *pool);
-extern struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *,
- int front_len);
+struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool, int front_len,
+ int max_data_items);
extern void ceph_msgpool_put(struct ceph_msgpool *, struct ceph_msg *);
#endif
