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authorJoe Thornber <ejt@redhat.com>2015-12-09 16:38:12 +0000
committerMike Snitzer <snitzer@redhat.com>2015-12-09 13:27:25 -0500
commit50dd842ad83b43bed71790efb31cfb2f6c05c9c1 (patch)
tree89ae0e1fc73b57d071fcec92d120fa3a19500cfd /drivers/md/persistent-data
parent49e99fc717f624aa75ca755d6e7bc029efd3f0e9 (diff)
downloadlinux-50dd842ad83b43bed71790efb31cfb2f6c05c9c1.tar.bz2
dm space map metadata: fix ref counting bug when bootstrapping a new space map
When applying block operations (BOPs) do not remove them from the uncommitted BOP ring-buffer until after they've been applied -- in case we recurse. Also, perform BOP_INC operation, in dm_sm_metadata_create() and sm_metadata_extend(), in terms of the uncommitted BOP ring-buffer rather than using direct calls to sm_ll_inc(). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/md/persistent-data')
-rw-r--r--drivers/md/persistent-data/dm-space-map-metadata.c32
1 files changed, 22 insertions, 10 deletions
diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
index 53091295fce9..fca6dbcf9a47 100644
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -136,7 +136,7 @@ static int brb_push(struct bop_ring_buffer *brb,
return 0;
}
-static int brb_pop(struct bop_ring_buffer *brb, struct block_op *result)
+static int brb_peek(struct bop_ring_buffer *brb, struct block_op *result)
{
struct block_op *bop;
@@ -147,6 +147,17 @@ static int brb_pop(struct bop_ring_buffer *brb, struct block_op *result)
result->type = bop->type;
result->block = bop->block;
+ return 0;
+}
+
+static int brb_pop(struct bop_ring_buffer *brb)
+{
+ struct block_op *bop;
+
+ if (brb_empty(brb))
+ return -ENODATA;
+
+ bop = brb->bops + brb->begin;
brb->begin = brb_next(brb, brb->begin);
return 0;
@@ -211,7 +222,7 @@ static int apply_bops(struct sm_metadata *smm)
while (!brb_empty(&smm->uncommitted)) {
struct block_op bop;
- r = brb_pop(&smm->uncommitted, &bop);
+ r = brb_peek(&smm->uncommitted, &bop);
if (r) {
DMERR("bug in bop ring buffer");
break;
@@ -220,6 +231,8 @@ static int apply_bops(struct sm_metadata *smm)
r = commit_bop(smm, &bop);
if (r)
break;
+
+ brb_pop(&smm->uncommitted);
}
return r;
@@ -683,7 +696,6 @@ static struct dm_space_map bootstrap_ops = {
static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
{
int r, i;
- enum allocation_event ev;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
dm_block_t old_len = smm->ll.nr_blocks;
@@ -705,11 +717,12 @@ static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
* allocate any new blocks.
*/
do {
- for (i = old_len; !r && i < smm->begin; i++) {
- r = sm_ll_inc(&smm->ll, i, &ev);
- if (r)
- goto out;
- }
+ for (i = old_len; !r && i < smm->begin; i++)
+ r = add_bop(smm, BOP_INC, i);
+
+ if (r)
+ goto out;
+
old_len = smm->begin;
r = apply_bops(smm);
@@ -754,7 +767,6 @@ int dm_sm_metadata_create(struct dm_space_map *sm,
{
int r;
dm_block_t i;
- enum allocation_event ev;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
smm->begin = superblock + 1;
@@ -782,7 +794,7 @@ int dm_sm_metadata_create(struct dm_space_map *sm,
* allocated blocks that they were built from.
*/
for (i = superblock; !r && i < smm->begin; i++)
- r = sm_ll_inc(&smm->ll, i, &ev);
+ r = add_bop(smm, BOP_INC, i);
if (r)
return r;