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authorJoe Thornber <ejt@redhat.com>2012-07-27 14:08:09 (GMT)
committerAlasdair G Kergon <agk@redhat.com>2012-07-27 14:08:09 (GMT)
commit2597119206405b9dbaee491e7c2389b7570b3227 (patch)
treee3b21489dd14fde4f8ed30c67f4431285c08852c
parent3c9ad9bd87b03032999ddbeb44bdf7938f7dbd57 (diff)
downloadlinux-2597119206405b9dbaee491e7c2389b7570b3227.tar.xz
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>
-rw-r--r--drivers/md/dm-thin-metadata.c41
1 files changed, 20 insertions, 21 deletions
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 4aadeae..dd3a89b 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -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;