From 2597119206405b9dbaee491e7c2389b7570b3227 Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Fri, 27 Jul 2012 15:08:09 +0100 Subject: dm thin metadata: wrap superblock locking Introduce wrappers to handle write locking the superblock appropriately. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-thin-metadata.c | 41 ++++++++++++++++++++--------------------- 1 file changed, 20 insertions(+), 21 deletions(-) diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 4aadeae3af6..dd3a89b1bf6 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; -- cgit v1.2.3