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 6644ed7b7e ("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 <leisurelysw24@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Ilya Dryomov 2018-10-15 17:38:23 +02:00
parent 26f887e0a3
commit 0d9c1ab3be
6 changed files with 157 additions and 115 deletions

View file

@ -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