From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joe Thornber , Mike Snitzer Subject: [PATCH 4.4 049/210] dm thin metadata: dont issue prefetches if a transaction abort has failed Date: Sun, 10 Apr 2016 11:34:30 -0700 Message-Id: <20160410183528.413882646@linuxfoundation.org> In-Reply-To: <20160410183526.651820045@linuxfoundation.org> References: <20160410183526.651820045@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joe Thornber commit 2eae9e4489b4cf83213fa3bd508b5afca3f01780 upstream. If a transaction abort has failed then we can no longer use the metadata device. Typically this happens if the superblock is unreadable. This fix addresses a crash seen during metadata device failure testing. Fixes: 8a01a6af75 ("dm thin: prefetch missing metadata pages") Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-thin-metadata.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1943,5 +1943,8 @@ bool dm_pool_metadata_needs_check(struct void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd) { - dm_tm_issue_prefetches(pmd->tm); + down_read(&pmd->root_lock); + if (!pmd->fail_io) + dm_tm_issue_prefetches(pmd->tm); + up_read(&pmd->root_lock); }