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authorSage Weil <sage@inktank.com>2012-07-30 18:19:45 -0700
committerSage Weil <sage@inktank.com>2012-07-30 18:19:45 -0700
commit6139919133377652992a5fe134e22abce3e9c25e (patch)
tree57245239564583e968e4e8fb94d493bde69fb18b /net
parent4740a623d20c51d167da7f752b63e2b8714b2543 (diff)
downloadlinux-6139919133377652992a5fe134e22abce3e9c25e.tar.gz
libceph: recheck con state after allocating incoming message
We drop the lock when calling the ->alloc_msg() con op, which means we need to (a) not clobber con->in_msg without the mutex held, and (b) we need to verify that we are still in the OPEN state when we retake it to avoid causing any mayhem. If the state does change, -EAGAIN will get us back to con_work() and loop. Signed-off-by: Sage Weil <sage@inktank.com> Reviewed-by: Alex Elder <elder@inktank.com>
Diffstat (limited to 'net')
-rw-r--r--net/ceph/messenger.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 13b549b6b1b..b6655b13155 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2735,9 +2735,16 @@ static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
BUG_ON(con->in_msg != NULL);
if (con->ops->alloc_msg) {
+ struct ceph_msg *msg;
+
mutex_unlock(&con->mutex);
- con->in_msg = con->ops->alloc_msg(con, hdr, skip);
+ msg = con->ops->alloc_msg(con, hdr, skip);
mutex_lock(&con->mutex);
+ if (con->state != CON_STATE_OPEN) {
+ ceph_msg_put(msg);
+ return -EAGAIN;
+ }
+ con->in_msg = msg;
if (con->in_msg) {
con->in_msg->con = con->ops->get(con);
BUG_ON(con->in_msg->con == NULL);