Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753705AbaLFPYQ (ORCPT ); Sat, 6 Dec 2014 10:24:16 -0500 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:47700 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752066AbaLFPIE (ORCPT ); Sat, 6 Dec 2014 10:08:04 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Jeff Layton , Markus Blank-Burian , Jiri Slaby Subject: [PATCH 3.12 64/66] locks: eliminate BUG() call when there's an unexpected lock on file close Date: Sat, 6 Dec 2014 16:07:56 +0100 Message-Id: X-Mailer: git-send-email 2.1.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jeff Layton 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 8c3cac5e6a85f03602ffe09c44f14418699e31ec upstream. A leftover lock on the list is surely a sign of a problem of some sort, but it's not necessarily a reason to panic the box. Instead, just log a warning with some info about the lock, and then delete it like we would any other lock. In the event that the filesystem declares a ->lock f_op, we may end up leaking something, but that's generally preferable to an immediate panic. Acked-by: J. Bruce Fields Signed-off-by: Jeff Layton Cc: Markus Blank-Burian Signed-off-by: Jiri Slaby --- fs/locks.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index ad95fbd20f8a..0d2b5febc627 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2199,16 +2199,28 @@ void locks_remove_flock(struct file *filp) while ((fl = *before) != NULL) { if (fl->fl_file == filp) { - if (IS_FLOCK(fl)) { - locks_delete_lock(before); - continue; - } if (IS_LEASE(fl)) { lease_modify(before, F_UNLCK); continue; } - /* What? */ - BUG(); + + /* + * There's a leftover lock on the list of a type that + * we didn't expect to see. Most likely a classic + * POSIX lock that ended up not getting released + * properly, or that raced onto the list somehow. Log + * some info about it and then just remove it from + * the list. + */ + WARN(!IS_FLOCK(fl), + "leftover lock: dev=%u:%u ino=%lu type=%hhd flags=0x%x start=%lld end=%lld\n", + MAJOR(inode->i_sb->s_dev), + MINOR(inode->i_sb->s_dev), inode->i_ino, + fl->fl_type, fl->fl_flags, + fl->fl_start, fl->fl_end); + + locks_delete_lock(before); + continue; } before = &fl->fl_next; } -- 2.1.3 -- 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/