| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.2 068/110] dm cache: the CLEAN_SHUTDOWN flag was not being set | Date | Fri, 6 Nov 2015 11:19:15 -0800 |
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4.2-stable review patch. If anyone has any objections, please let me know.
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From: Joe Thornber <ejt@redhat.com>
commit 3201ac452e84a8a368197d648c9b7011e061804a upstream.
If the CLEAN_SHUTDOWN flag is not set when a cache is loaded then all cache blocks are marked as dirty and a full writeback occurs.
__commit_transaction() is responsible for setting/clearing CLEAN_SHUTDOWN (based the flags_mutator that is passed in).
Fix this issue, of the cache's on-disk flags being wrong, by making sure __commit_transaction() does not reset the flags after the mutator has altered the flags in preparation for them being serialized to disk.
before:
sb_flags = mutator(le32_to_cpu(disk_super->flags)); disk_super->flags = cpu_to_le32(sb_flags); disk_super->flags = cpu_to_le32(cmd->flags);
after:
disk_super->flags = cpu_to_le32(cmd->flags); sb_flags = mutator(le32_to_cpu(disk_super->flags)); disk_super->flags = cpu_to_le32(sb_flags);
Reported-by: Bogdan Vasiliev <bogdan.vasiliev@gmail.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/dm-cache-metadata.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -634,10 +634,10 @@ static int __commit_transaction(struct d disk_super = dm_block_data(sblock); + disk_super->flags = cpu_to_le32(cmd->flags); if (mutator) update_flags(disk_super, mutator); - disk_super->flags = cpu_to_le32(cmd->flags); disk_super->mapping_root = cpu_to_le64(cmd->root); disk_super->hint_root = cpu_to_le64(cmd->hint_root); disk_super->discard_root = cpu_to_le64(cmd->discard_root);
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