From: Greg KH Subject: [patch 21/39] ext4: Dont overwrite allocation_context ac_status Date: Wed, 18 Feb 2009 13:32:53 -0800 Message-ID: <20090218213253.GV19814@kroah.com> References: <20090218212144.965748151@mini.kroah.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Justin Forbes , Zwane Mwaikambo , Theodore Ts'o , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, linux-ext4@vger.kernel.org, "Aneesh Kumar K.V" To: linux-kernel@vger.kernel.org, stable@kernel.org Return-path: Received: from kroah.org ([198.145.64.141]:56267 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757050AbZBRVfr (ORCPT ); Wed, 18 Feb 2009 16:35:47 -0500 Content-Disposition: inline; filename="ext4-don-t-overwrite-allocation_context-ac_status.patch" In-Reply-To: <20090218213021.GA19814@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2.6.28-stable review patch. If anyone has any objections, please let us know. ------------------ From: Aneesh Kumar K.V (cherry picked from commit 032115fcef837a00336ddf7bda584e89789ea498) We can call ext4_mb_check_limits even after successfully allocating the requested blocks. In that case, make sure we don't overwrite ac_status if it already has the status AC_STATUS_FOUND. This fixes the lockdep warning: ============================================= [ INFO: possible recursive locking detected ] 2.6.28-rc6-autokern1 #1 --------------------------------------------- fsstress/11948 is trying to acquire lock: (&meta_group_info[i]->alloc_sem){----}, at: [] ext4_mb_load_buddy+0x9f/0x278 ..... stack backtrace: ..... [] ext4_mb_regular_allocator+0xbb5/0xd44 ..... but task is already holding lock: (&meta_group_info[i]->alloc_sem){----}, at: [] ext4_mb_load_buddy+0x9f/0x278 Signed-off-by: Aneesh Kumar K.V Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/mballoc.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1326,6 +1326,8 @@ static void ext4_mb_check_limits(struct struct ext4_free_extent ex; int max; + if (ac->ac_status == AC_STATUS_FOUND) + return; /* * We don't want to scan for a whole year */