From 1eeb9f22140f77011d00363ba5184312c74f15ad Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Tue, 22 May 2012 16:33:01 +0100 Subject: [PATCH 15/41] dm thin metadata: add superblock_lock and superblock_lock_zero Introduce wrappers to handle write locking the superblock appropriately. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/dm-thin-metadata.c | 42 +++++++++++++++++++--------------------- 1 files changed, 20 insertions(+), 22 deletions(-) diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 6be601b..a57617f 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; @@ -392,23 +406,11 @@ 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 it's - * 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; @@ -625,8 +627,7 @@ static int __commit_transaction(struct dm_pool_metadata *pmd) if (r < 0) goto out; - r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, - &sb_validator, &sblock); + r = superblock_lock(pmd, &sblock); if (r) goto out; @@ -709,8 +710,7 @@ 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 +1126,7 @@ 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 +1156,7 @@ 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; -- 1.7.1