dm thin metadata: wrap superblock locking

Introduce wrappers to handle write locking the superblock
appropriately.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Joe Thornber 2012-07-27 15:08:09 +01:00 committed by Alasdair G Kergon
parent 3c9ad9bd87
commit 2597119206
1 changed files with 20 additions and 21 deletions

View File

@ -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;