lkml.org 
[lkml]   [2012]   [Nov]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 139/270] libceph: avoid dropping con mutex before fault
Date
3.5.7u1 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sage Weil <sage@inktank.com>

commit 8636ea672f0c5ab7478c42c5b6705ebd1db7eb6a upstream.

The ceph_fault() function takes the con mutex, so we should avoid
dropping it before calling it. This fixes a potential race with
another thread calling ceph_con_close(), or _open(), or similar (we
don't reverify con->state after retaking the lock).

Add annotation so that lockdep realizes we will drop the mutex before
returning.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
net/ceph/messenger.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index feb5a2a..c3b628c 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2336,7 +2336,6 @@ done_unlocked:
return;

fault:
- mutex_unlock(&con->mutex);
ceph_fault(con); /* error/fault path */
goto done_unlocked;
}
@@ -2347,9 +2346,8 @@ fault:
* exponential backoff
*/
static void ceph_fault(struct ceph_connection *con)
+ __releases(con->mutex)
{
- mutex_lock(&con->mutex);
-
pr_err("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
ceph_pr_addr(&con->peer_addr.in_addr), con->error_msg);
dout("fault %p state %lu to peer %s\n",
--
1.7.9.5


\
 
 \ /
  Last update: 2012-11-26 20:21    [W:1.418 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site