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authorSage Weil <sage@inktank.com>2012-07-30 18:19:45 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-11-26 11:38:42 -0800
commit59238927cc8ea6c1e4a8a1136e17598648832db0 (patch)
treeb2039951363d52164113f84a84823be816758e18
parent7389a76f02bf56340f26fa933b9fc6a1dece9148 (diff)
downloadlwn-59238927cc8ea6c1e4a8a1136e17598648832db0.tar.gz
lwn-59238927cc8ea6c1e4a8a1136e17598648832db0.zip
libceph: recheck con state after allocating incoming message
(cherry picked from commit 6139919133377652992a5fe134e22abce3e9c25e) 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 bfd0878c5c4e..0de5a706f2b7 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);