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

@@ -2071,7 +2071,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
if (req->r_old_dentry_drop)
len += req->r_old_dentry->d_name.len;
msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
if (!msg) {
msg = ERR_PTR(-ENOMEM);
goto out_free2;
@@ -3129,7 +3129,7 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
if (!pagelist)
goto fail_nopagelist;
reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
if (!reply)
goto fail_nomsg;