dm thin: avoid metadata commit if a pool's thin devices haven't changed
Commit 905e51b ("dm thin: commit outstanding data every second")
introduced a periodic commit. This commit occurs regardless of whether
any thin devices have made changes.
Fix the periodic commit to check if any of a pool's thin devices have
changed using dm_pool_changed_this_transaction().
Reported-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 7da3476..3bb4506 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -1489,6 +1489,23 @@
return r;
}
+bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
+{
+ bool r = false;
+ struct dm_thin_device *td, *tmp;
+
+ down_read(&pmd->root_lock);
+ list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
+ if (td->changed) {
+ r = td->changed;
+ break;
+ }
+ }
+ up_read(&pmd->root_lock);
+
+ return r;
+}
+
bool dm_thin_aborted_changes(struct dm_thin_device *td)
{
bool r;