Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932633AbbKMKLQ (ORCPT ); Fri, 13 Nov 2015 05:11:16 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:48703 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932308AbbKMKLK (ORCPT ); Fri, 13 Nov 2015 05:11:10 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Joe Thornber , Mike Snitzer , Luis Henriques Subject: [PATCH 3.16.y-ckt 19/94] dm cache: fix NULL pointer when switching from cleaner policy Date: Fri, 13 Nov 2015 10:09:13 +0000 Message-Id: <1447409428-12178-20-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1447409428-12178-1-git-send-email-luis.henriques@canonical.com> References: <1447409428-12178-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1614 Lines: 42 3.16.7-ckt20 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Joe Thornber commit 2bffa1503c5c06192eb1459180fac4416575a966 upstream. The cleaner policy doesn't make use of the per cache block hint space in the metadata (unlike the other policies). When switching from the cleaner policy to mq or smq a NULL pointer crash (in dm_tm_new_block) was observed. The crash was caused by bugs in dm-cache-metadata.c when trying to skip creation of the hint btree. The minimal fix is to change hint size for the cleaner policy to 4 bytes (only hint size supported). Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Luis Henriques --- drivers/md/dm-cache-policy-cleaner.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/dm-cache-policy-cleaner.c b/drivers/md/dm-cache-policy-cleaner.c index b04d1f904d07..2eca9084defe 100644 --- a/drivers/md/dm-cache-policy-cleaner.c +++ b/drivers/md/dm-cache-policy-cleaner.c @@ -434,7 +434,7 @@ static struct dm_cache_policy *wb_create(dm_cblock_t cache_size, static struct dm_cache_policy_type wb_policy_type = { .name = "cleaner", .version = {1, 0, 0}, - .hint_size = 0, + .hint_size = 4, .owner = THIS_MODULE, .create = wb_create }; -- 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/