diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-02 17:39:40 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-02 17:39:40 -0700 |
commit | 912afc3616b94c5c4af584972c7f5903b53cf15a (patch) | |
tree | 3edd4596fe53ce5bc8224b1cccd5d34dcac040a7 /drivers/md/dm-thin-metadata.c | |
parent | 4fc3acf2918fa158dc651a0c824a23944e956919 (diff) | |
parent | cc8394d86f045b86ff303d3c9e4ce47d97148951 (diff) |
Merge tag 'dm-3.5-changes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm
Pull device-mapper updates from Alasdair G Kergon:
"Improve multipath's retrying mechanism in some defined circumstances
and provide a simple reserve/release mechanism for userspace tools to
access thin provisioning metadata while the pool is in use."
* tag 'dm-3.5-changes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
dm thin: provide userspace access to pool metadata
dm thin: use slab mempools
dm mpath: allow ioctls to trigger pg init
dm mpath: delay retry of bypassed pg
dm mpath: reduce size of struct multipath
Diffstat (limited to 'drivers/md/dm-thin-metadata.c')
-rw-r--r-- | drivers/md/dm-thin-metadata.c | 136 |
1 files changed, 130 insertions, 6 deletions
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 737d38865b6..3e2907f0bc4 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1082,12 +1082,89 @@ int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, return 0; } -static int __get_held_metadata_root(struct dm_pool_metadata *pmd, - dm_block_t *result) +static int __reserve_metadata_snap(struct dm_pool_metadata *pmd) +{ + int r, inc; + struct thin_disk_superblock *disk_super; + struct dm_block *copy, *sblock; + dm_block_t held_root; + + /* + * Copy the superblock. + */ + dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION); + r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION, + &sb_validator, ©, &inc); + if (r) + return r; + + BUG_ON(!inc); + + held_root = dm_block_location(copy); + disk_super = dm_block_data(copy); + + if (le64_to_cpu(disk_super->held_root)) { + DMWARN("Pool metadata snapshot already exists: release this before taking another."); + + dm_tm_dec(pmd->tm, held_root); + dm_tm_unlock(pmd->tm, copy); + pmd->need_commit = 1; + + return -EBUSY; + } + + /* + * Wipe the spacemap since we're not publishing this. + */ + memset(&disk_super->data_space_map_root, 0, + sizeof(disk_super->data_space_map_root)); + memset(&disk_super->metadata_space_map_root, 0, + sizeof(disk_super->metadata_space_map_root)); + + /* + * Increment the data structures that need to be preserved. + */ + dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root)); + dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root)); + dm_tm_unlock(pmd->tm, copy); + + /* + * Write the held root into the superblock. + */ + r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, + &sb_validator, &sblock); + if (r) { + dm_tm_dec(pmd->tm, held_root); + pmd->need_commit = 1; + return r; + } + + disk_super = dm_block_data(sblock); + disk_super->held_root = cpu_to_le64(held_root); + dm_bm_unlock(sblock); + + pmd->need_commit = 1; + + return 0; +} + +int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd) +{ + int r; + + down_write(&pmd->root_lock); + r = __reserve_metadata_snap(pmd); + up_write(&pmd->root_lock); + + return r; +} + +static int __release_metadata_snap(struct dm_pool_metadata *pmd) { int r; struct thin_disk_superblock *disk_super; - struct dm_block *sblock; + struct dm_block *sblock, *copy; + dm_block_t held_root; r = dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, &sb_validator, &sblock); @@ -1095,18 +1172,65 @@ static int __get_held_metadata_root(struct dm_pool_metadata *pmd, return r; disk_super = dm_block_data(sblock); + held_root = le64_to_cpu(disk_super->held_root); + disk_super->held_root = cpu_to_le64(0); + pmd->need_commit = 1; + + dm_bm_unlock(sblock); + + if (!held_root) { + DMWARN("No pool metadata snapshot found: nothing to release."); + return -EINVAL; + } + + r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©); + if (r) + return r; + + disk_super = dm_block_data(copy); + dm_sm_dec_block(pmd->metadata_sm, le64_to_cpu(disk_super->data_mapping_root)); + dm_sm_dec_block(pmd->metadata_sm, le64_to_cpu(disk_super->device_details_root)); + dm_sm_dec_block(pmd->metadata_sm, held_root); + + return dm_tm_unlock(pmd->tm, copy); +} + +int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd) +{ + int r; + + down_write(&pmd->root_lock); + r = __release_metadata_snap(pmd); + up_write(&pmd->root_lock); + + return r; +} + +static int __get_metadata_snap(struct dm_pool_metadata *pmd, + dm_block_t *result) +{ + int r; + struct thin_disk_superblock *disk_super; + struct dm_block *sblock; + + r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, + &sb_validator, &sblock); + if (r) + return r; + + disk_super = dm_block_data(sblock); *result = le64_to_cpu(disk_super->held_root); return dm_bm_unlock(sblock); } -int dm_pool_get_held_metadata_root(struct dm_pool_metadata *pmd, - dm_block_t *result) +int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, + dm_block_t *result) { int r; down_read(&pmd->root_lock); - r = __get_held_metadata_root(pmd, result); + r = __get_metadata_snap(pmd, result); up_read(&pmd->root_lock); return r; |