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authorJoe Thornber <ejt@redhat.com>2015-06-17 13:35:19 +0100
committerMike Snitzer <snitzer@redhat.com>2015-06-17 10:09:23 -0400
commit6096d91af0b65a3967139b32d5adbb3647858a26 (patch)
tree1c78bce04092967acee14e57887ab64c48d865a7
parentb1f11aff04cc86daa0757ada5deb669a92a8f0fb (diff)
dm space map metadata: fix occasional leak of a metadata block on resize
The metadata space map has a simplified 'bootstrap' mode that is operational when extending the space maps. Whilst in this mode it's possible for some refcount decrement operations to become queued (eg, as a result of shadowing one of the bitmap indexes). These decrements were not being applied when switching out of bootstrap mode. The effect of this bug was the leaking of a 4k metadata block. This is detected by the latest version of thin_check as a non fatal error. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
-rw-r--r--drivers/md/persistent-data/dm-space-map-metadata.c50
1 files changed, 35 insertions, 15 deletions
diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
index e8a904298887..53091295fce9 100644
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -204,6 +204,27 @@ static void in(struct sm_metadata *smm)
smm->recursion_count++;
}
+static int apply_bops(struct sm_metadata *smm)
+{
+ int r = 0;
+
+ while (!brb_empty(&smm->uncommitted)) {
+ struct block_op bop;
+
+ r = brb_pop(&smm->uncommitted, &bop);
+ if (r) {
+ DMERR("bug in bop ring buffer");
+ break;
+ }
+
+ r = commit_bop(smm, &bop);
+ if (r)
+ break;
+ }
+
+ return r;
+}
+
static int out(struct sm_metadata *smm)
{
int r = 0;
@@ -216,21 +237,8 @@ static int out(struct sm_metadata *smm)
return -ENOMEM;
}
- if (smm->recursion_count == 1) {
- while (!brb_empty(&smm->uncommitted)) {
- struct block_op bop;
-
- r = brb_pop(&smm->uncommitted, &bop);
- if (r) {
- DMERR("bug in bop ring buffer");
- break;
- }
-
- r = commit_bop(smm, &bop);
- if (r)
- break;
- }
- }
+ if (smm->recursion_count == 1)
+ apply_bops(smm);
smm->recursion_count--;
@@ -704,6 +712,12 @@ static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
}
old_len = smm->begin;
+ r = apply_bops(smm);
+ if (r) {
+ DMERR("%s: apply_bops failed", __func__);
+ goto out;
+ }
+
r = sm_ll_commit(&smm->ll);
if (r)
goto out;
@@ -773,6 +787,12 @@ int dm_sm_metadata_create(struct dm_space_map *sm,
if (r)
return r;
+ r = apply_bops(smm);
+ if (r) {
+ DMERR("%s: apply_bops failed", __func__);
+ return r;
+ }
+
return sm_metadata_commit(sm);
}