From 78243d0a1221f06af96a8952cd5ac71cd1fe5376 Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Tue, 1 Mar 2016 10:58:44 +0000 Subject: [PATCH] dm thin metadata: don't issue prefetches if a transaction abort has failed [ Upstream commit 2eae9e4489b4cf83213fa3bd508b5afca3f01780 ] 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") Cc: stable@vger.kernel.org # 3.19+ Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin --- drivers/md/dm-thin-metadata.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index cde1d67..9b4f73e 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1803,5 +1803,8 @@ bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd) 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); } -- 2.7.4