diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index b6a2d2081a24..a010ff1e5c92 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -186,6 +186,7 @@ struct dm_pool_metadata { uint32_t time; dm_block_t root; dm_block_t details_root; + dm_block_t held_root; struct list_head thin_devices; uint64_t trans_id; unsigned long flags; @@ -748,6 +749,7 @@ static int __open_metadata(struct dm_pool_metadata *pmd) */ pmd->root = le64_to_cpu(disk_super->data_mapping_root); pmd->details_root = le64_to_cpu(disk_super->device_details_root); + pmd->held_root = le64_to_cpu(disk_super->held_root); __setup_btree_details(pmd); dm_bm_unlock(sblock); @@ -838,6 +840,7 @@ static int __begin_transaction(struct dm_pool_metadata *pmd) pmd->time = le32_to_cpu(disk_super->time); pmd->root = le64_to_cpu(disk_super->data_mapping_root); pmd->details_root = le64_to_cpu(disk_super->device_details_root); + pmd->held_root = le64_to_cpu(disk_super->held_root); pmd->trans_id = le64_to_cpu(disk_super->trans_id); pmd->flags = le32_to_cpu(disk_super->flags); pmd->data_block_size = le32_to_cpu(disk_super->data_block_size); @@ -928,6 +931,7 @@ static int __commit_transaction(struct dm_pool_metadata *pmd) disk_super->time = cpu_to_le32(pmd->time); disk_super->data_mapping_root = cpu_to_le64(pmd->root); disk_super->device_details_root = cpu_to_le64(pmd->details_root); + disk_super->held_root = cpu_to_le64(pmd->held_root); disk_super->trans_id = cpu_to_le64(pmd->trans_id); disk_super->flags = cpu_to_le32(pmd->flags); @@ -1333,9 +1337,14 @@ static int __reserve_metadata_snap(struct dm_pool_metadata *pmd) { int r, inc; struct thin_disk_superblock *disk_super; - struct dm_block *copy, *sblock; + struct dm_block *copy; dm_block_t held_root; + if (pmd->held_root) { + DMWARN("Pool metadata snapshot already exists: release this before taking another."); + return -EBUSY; + } + /* * We commit to ensure the btree roots which we increment in a * moment are up to date. @@ -1361,14 +1370,6 @@ static int __reserve_metadata_snap(struct dm_pool_metadata *pmd) 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); - return -EBUSY; - } - /* * Wipe the spacemap since we're not publishing this. */ @@ -1384,18 +1385,8 @@ static int __reserve_metadata_snap(struct dm_pool_metadata *pmd) 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 = superblock_lock(pmd, &sblock); - if (r) { - dm_tm_dec(pmd->tm, held_root); - return r; - } + pmd->held_root = held_root; - disk_super = dm_block_data(sblock); - disk_super->held_root = cpu_to_le64(held_root); - dm_bm_unlock(sblock); return 0; } @@ -1415,18 +1406,10 @@ static int __release_metadata_snap(struct dm_pool_metadata *pmd) { int r; struct thin_disk_superblock *disk_super; - struct dm_block *sblock, *copy; + struct dm_block *copy; dm_block_t held_root; - r = superblock_lock(pmd, &sblock); - if (r) - 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); - - dm_bm_unlock(sblock); + held_root = pmd->held_root; if (!held_root) { DMWARN("No pool metadata snapshot found: nothing to release."); @@ -1437,13 +1420,15 @@ static int __release_metadata_snap(struct dm_pool_metadata *pmd) if (r) return r; + pmd->held_root = 0; + disk_super = dm_block_data(copy); dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root)); dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root)); - dm_sm_dec_block(pmd->metadata_sm, held_root); - dm_tm_unlock(pmd->tm, copy); + dm_sm_dec_block(pmd->metadata_sm, held_root); + return 0; } @@ -1462,19 +1447,7 @@ int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd) 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); - - dm_bm_unlock(sblock); + *result = pmd->held_root; return 0; }