Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 50dd842a authored by Joe Thornber's avatar Joe Thornber Committed by Mike Snitzer
Browse files

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: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
parent 49e99fc7

drivers/md/persistent-data/dm-space-map-metadata.c

+22 −10
Original line number Diff line number Diff line
@@ -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);

		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;