Commit 25971192 authored by Joe Thornber's avatar Joe Thornber Committed by Alasdair G Kergon
Browse files

dm thin metadata: wrap superblock locking 



Introduce wrappers to handle write locking the superblock
appropriately.

Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 3c9ad9bd

drivers/md/dm-thin-metadata.c

+20 −21
Original line number Diff line number Diff line
@@ -343,6 +343,20 @@ static int subtree_equal(void *context, void *value1_le, void *value2_le) 


/*----------------------------------------------------------------*/



static int superblock_lock_zero(struct dm_pool_metadata *pmd,

				struct dm_block **sblock)

{

	return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,

				     &sb_validator, sblock);

}



static int superblock_lock(struct dm_pool_metadata *pmd,

			   struct dm_block **sblock)

{

	return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,

				&sb_validator, sblock);

}



static int superblock_all_zeroes(struct dm_block_manager *bm, int *result)

{

	int r;
@@ -430,22 +444,11 @@ static int init_pmd(struct dm_pool_metadata *pmd, 
			r = PTR_ERR(data_sm);

			goto bad;

		}



		/*

		 * We cycle the superblock to let the validator do its stuff.

		 */

		r = dm_bm_write_lock_zero(bm, THIN_SUPERBLOCK_LOCATION, &sb_validator, &sblock);

		if (r < 0) {

			DMERR("couldn't lock superblock");

			goto bad;

		}



		dm_bm_unlock(sblock);



	} else {

		struct thin_disk_superblock *disk_super;



		r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, &sb_validator, &sblock);

		r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION,

				    &sb_validator, &sblock);

		if (r < 0) {

			DMERR("couldn't read superblock");

			return r;
@@ -628,8 +631,7 @@ static int __commit_transaction(struct dm_pool_metadata *pmd) 
	if (r < 0)

		return r;



	r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,

			     &sb_validator, &sblock);

	r = superblock_lock(pmd, &sblock);

	if (r)

		return r;
@@ -709,8 +711,7 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, 
	/*

	 * Create.

	 */

	r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,

			     &sb_validator, &sblock);

	r = superblock_lock_zero(pmd, &sblock);

	if (r)

		goto bad;
@@ -1126,8 +1127,7 @@ static int __reserve_metadata_snap(struct dm_pool_metadata *pmd) 
	/*

	 * Write the held root into the superblock.

	 */

	r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,

			     &sb_validator, &sblock);

	r = superblock_lock(pmd, &sblock);

	if (r) {

		dm_tm_dec(pmd->tm, held_root);

		return r;
@@ -1157,8 +1157,7 @@ static int __release_metadata_snap(struct dm_pool_metadata *pmd) 
	struct dm_block *sblock, *copy;

	dm_block_t held_root;



	r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,

			     &sb_validator, &sblock);

	r = superblock_lock(pmd, &sblock);

	if (r)

		return r;