From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033909AbdEWU45 (ORCPT ); Tue, 23 May 2017 16:56:57 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49858 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033338AbdEWUfG (ORCPT ); Tue, 23 May 2017 16:35:06 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Mike Snitzer Subject: [PATCH 4.4 014/103] dm cache metadata: fail operations if fail_io mode has been established Date: Tue, 23 May 2017 22:08:40 +0200 Message-Id: <20170523200858.579524208@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170523200856.903752266@linuxfoundation.org> References: <20170523200856.903752266@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Snitzer commit 10add84e276432d9dd8044679a1028dd4084117e upstream. Otherwise it is possible to trigger crashes due to the metadata being inaccessible yet these methods don't safely account for that possibility without these checks. Reported-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-cache-metadata.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -1326,17 +1326,19 @@ void dm_cache_metadata_set_stats(struct int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown) { - int r; + int r = -EINVAL; flags_mutator mutator = (clean_shutdown ? set_clean_shutdown : clear_clean_shutdown); WRITE_LOCK(cmd); + if (cmd->fail_io) + goto out; + r = __commit_transaction(cmd, mutator); if (r) goto out; r = __begin_transaction(cmd); - out: WRITE_UNLOCK(cmd); return r; @@ -1348,7 +1350,8 @@ int dm_cache_get_free_metadata_block_cou int r = -EINVAL; READ_LOCK(cmd); - r = dm_sm_get_nr_free(cmd->metadata_sm, result); + if (!cmd->fail_io) + r = dm_sm_get_nr_free(cmd->metadata_sm, result); READ_UNLOCK(cmd); return r; @@ -1360,7 +1363,8 @@ int dm_cache_get_metadata_dev_size(struc int r = -EINVAL; READ_LOCK(cmd); - r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); + if (!cmd->fail_io) + r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); READ_UNLOCK(cmd); return r;