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.