diff options
| -rw-r--r-- | drivers/md/dm-thin-metadata.c | 57 | ||||
| -rw-r--r-- | drivers/md/dm-thin-metadata.h | 9 |
2 files changed, 66 insertions, 0 deletions
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index cb6dd055053d..94cf0db8a22e 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1417,6 +1417,63 @@ int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, return r; } +/* FIXME: write a more efficient one in btree */ +int dm_thin_find_mapped_range(struct dm_thin_device *td, + dm_block_t begin, dm_block_t end, + dm_block_t *thin_begin, dm_block_t *thin_end, + dm_block_t *pool_begin, bool *maybe_shared) +{ + int r; + dm_block_t pool_end; + struct dm_thin_lookup_result lookup; + + if (end < begin) + return -ENODATA; + + /* + * Find first mapped block. + */ + while (begin < end) { + r = dm_thin_find_block(td, begin, true, &lookup); + if (r) { + if (r != -ENODATA) + return r; + } else + break; + + begin++; + } + + if (begin == end) + return -ENODATA; + + *thin_begin = begin; + *pool_begin = lookup.block; + *maybe_shared = lookup.shared; + + begin++; + pool_end = *pool_begin + 1; + while (begin != end) { + r = dm_thin_find_block(td, begin, true, &lookup); + if (r) { + if (r == -ENODATA) + break; + else + return r; + } + + if ((lookup.block != pool_end) || + (lookup.shared != *maybe_shared)) + break; + + pool_end++; + begin++; + } + + *thin_end = begin; + return 0; +} + static int __insert(struct dm_thin_device *td, dm_block_t block, dm_block_t data_block) { diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h index fac01a96d303..f11f14095b93 100644 --- a/drivers/md/dm-thin-metadata.h +++ b/drivers/md/dm-thin-metadata.h @@ -147,6 +147,15 @@ int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, int can_issue_io, struct dm_thin_lookup_result *result); /* + * Retrieve the next run of contiguously mapped blocks. Useful for working + * out where to break up IO. Returns 0 on success, < 0 on error. + */ +int dm_thin_find_mapped_range(struct dm_thin_device *td, + dm_block_t begin, dm_block_t end, + dm_block_t *thin_begin, dm_block_t *thin_end, + dm_block_t *pool_begin, bool *maybe_shared); + +/* * Obtain an unused block. */ int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result); |