diff options
| author | Joe Thornber <ejt@redhat.com> | 2014-10-06 15:24:55 +0100 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2014-11-10 15:25:26 -0500 |
| commit | e5cfc69a513cdc9d9e753c5ce07f0cc6b496bfd3 (patch) | |
| tree | 720c80d4d1cda8be53296d215bcfed7c404cf45b | |
| parent | a195db2d29a47c2c3a61386009bd400df18c86cf (diff) | |
dm thin metadata: change dm_thin_find_block to allow blocking, but not issuing, IO
This change is a prerequisite for allowing metadata to be prefetched.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| -rw-r--r-- | drivers/md/dm-thin-metadata.c | 30 | ||||
| -rw-r--r-- | drivers/md/dm-thin-metadata.h | 4 |
2 files changed, 15 insertions, 19 deletions
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index e9d33ad59df5..ee42d1c52387 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1384,42 +1384,38 @@ static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time) } int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, - int can_block, struct dm_thin_lookup_result *result) + int can_issue_io, struct dm_thin_lookup_result *result) { - int r = -EINVAL; - uint64_t block_time = 0; + int r; __le64 value; struct dm_pool_metadata *pmd = td->pmd; dm_block_t keys[2] = { td->id, block }; struct dm_btree_info *info; - if (can_block) { - down_read(&pmd->root_lock); - info = &pmd->info; - } else if (down_read_trylock(&pmd->root_lock)) - info = &pmd->nb_info; - else - return -EWOULDBLOCK; - if (pmd->fail_io) - goto out; + return -EINVAL; - r = dm_btree_lookup(info, pmd->root, keys, &value); - if (!r) - block_time = le64_to_cpu(value); + down_read(&pmd->root_lock); -out: - up_read(&pmd->root_lock); + if (can_issue_io) { + info = &pmd->info; + } else + info = &pmd->nb_info; + r = dm_btree_lookup(info, pmd->root, keys, &value); if (!r) { + uint64_t block_time = 0; dm_block_t exception_block; uint32_t exception_time; + + block_time = le64_to_cpu(value); unpack_block_time(block_time, &exception_block, &exception_time); result->block = exception_block; result->shared = __snapshotted_since(td, exception_time); } + up_read(&pmd->root_lock); return r; } diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h index e3c857db195a..efedd5a4cd8f 100644 --- a/drivers/md/dm-thin-metadata.h +++ b/drivers/md/dm-thin-metadata.h @@ -139,12 +139,12 @@ struct dm_thin_lookup_result { /* * Returns: - * -EWOULDBLOCK iff @can_block is set and would block. + * -EWOULDBLOCK iff @can_issue_io is set and would issue IO * -ENODATA iff that mapping is not present. * 0 success */ int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, - int can_block, struct dm_thin_lookup_result *result); + int can_issue_io, struct dm_thin_lookup_result *result); /* * Obtain an unused block. |