diff options
| author | Joe Thornber <ejt@redhat.com> | 2015-06-17 14:35:19 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2015-06-17 16:09:23 +0200 |
| commit | 6096d91af0b65a3967139b32d5adbb3647858a26 (patch) | |
| tree | 1c78bce04092967acee14e57887ab64c48d865a7 | |
| parent | dm thin metadata: fix a race when entering fail mode (diff) | |
| download | linux-6096d91af0b65a3967139b32d5adbb3647858a26.tar.xz linux-6096d91af0b65a3967139b32d5adbb3647858a26.zip | |
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.c | 50 |
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); } |