diff options
Diffstat (limited to 'drivers/md/dm-thin-metadata.c')
| -rw-r--r-- | drivers/md/dm-thin-metadata.c | 45 |
1 files changed, 35 insertions, 10 deletions
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 36ef284ad086..74f6770c70b1 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -189,6 +189,12 @@ struct dm_pool_metadata { sector_t data_block_size; /* + * We reserve a section of the metadata for commit overhead. + * All reported space does *not* include this. + */ + dm_block_t metadata_reserve; + + /* * Set if a transaction has to be aborted but the attempt to roll back * to the previous (good) transaction failed. The only pool metadata * operation possible in this state is the closing of the device. @@ -776,7 +782,6 @@ static int __write_changed_details(struct dm_pool_metadata *pmd) static int __commit_transaction(struct dm_pool_metadata *pmd) { int r; - size_t metadata_len, data_len; struct thin_disk_superblock *disk_super; struct dm_block *sblock; @@ -797,14 +802,6 @@ static int __commit_transaction(struct dm_pool_metadata *pmd) if (r < 0) return r; - r = dm_sm_root_size(pmd->metadata_sm, &metadata_len); - if (r < 0) - return r; - - r = dm_sm_root_size(pmd->data_sm, &data_len); - if (r < 0) - return r; - r = save_sm_roots(pmd); if (r < 0) return r; @@ -825,6 +822,22 @@ static int __commit_transaction(struct dm_pool_metadata *pmd) return dm_tm_commit(pmd->tm, sblock); } +static void __set_metadata_reserve(struct dm_pool_metadata *pmd) +{ + int r; + dm_block_t total; + dm_block_t max_blocks = 4096; /* 16M */ + + r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total); + if (r) { + DMERR("could not get size of metadata device"); + pmd->metadata_reserve = max_blocks; + } else { + sector_div(total, 10); + pmd->metadata_reserve = min(max_blocks, total); + } +} + struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, sector_t data_block_size, bool format_device) @@ -858,6 +871,8 @@ struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, return ERR_PTR(r); } + __set_metadata_reserve(pmd); + return pmd; } @@ -1829,6 +1844,13 @@ int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, down_read(&pmd->root_lock); if (!pmd->fail_io) r = dm_sm_get_nr_free(pmd->metadata_sm, result); + + if (!r) { + if (*result < pmd->metadata_reserve) + *result = 0; + else + *result -= pmd->metadata_reserve; + } up_read(&pmd->root_lock); return r; @@ -1941,8 +1963,11 @@ int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_cou int r = -EINVAL; down_write(&pmd->root_lock); - if (!pmd->fail_io) + if (!pmd->fail_io) { r = __resize_space_map(pmd->metadata_sm, new_count); + if (!r) + __set_metadata_reserve(pmd); + } up_write(&pmd->root_lock); return r; |