Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757003Ab2KZRu3 (ORCPT ); Mon, 26 Nov 2012 12:50:29 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:47650 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933202Ab2KZRIc (ORCPT ); Mon, 26 Nov 2012 12:08:32 -0500 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Sage Weil , Herton Ronaldo Krzesinski Subject: [PATCH 139/270] libceph: avoid dropping con mutex before fault Date: Mon, 26 Nov 2012 14:57:09 -0200 Message-Id: <1353949160-26803-140-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> References: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1668 Lines: 54 3.5.7u1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Sage Weil 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 Reviewed-by: Alex Elder Signed-off-by: Herton Ronaldo Krzesinski --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/