From: Joe Thornber Date: Tue, 1 Mar 2016 10:58:44 +0000 (+0000) Subject: dm thin metadata: don't issue prefetches if a transaction abort has failed X-Git-Tag: v4.6-rc1~132^2~7 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2eae9e4489b4cf83213fa3bd508b5afca3f01780;p=karo-tx-linux.git dm thin metadata: don't issue prefetches if a transaction abort has failed 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 --- diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index dc947f54824e..43824d73366d 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1981,5 +1981,8 @@ 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); }