1 files changed, 14 insertions, 5 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0d73a53c6763..b92e92c29e3b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2152,11 +2152,13 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
         }
         search_start = max(search_start, first_logical_byte(root, 0));
         search_start = max(search_start, hint_byte);
-        total_needed += empty_size;
 
-        if (search_start != last_wanted)
+        if (last_wanted && search_start != last_wanted) {
                 last_wanted = 0;
+                empty_size += empty_cluster;
+        }
 
+        total_needed += empty_size;
         block_group = btrfs_lookup_block_group(root->fs_info, search_start);
         if (!block_group)
                 block_group = btrfs_lookup_first_block_group(root->fs_info,
@@ -2171,7 +2173,9 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
                  * group thats not of the proper type, while looping this
                  * should never happen
                  */
-                WARN_ON(!block_group);
+                if (!block_group)
+                        goto new_group_no_lock;
+
                 mutex_lock(&block_group->alloc_mutex);
                 if (unlikely(!block_group_bits(block_group, data)))
                         goto new_group;
@@ -2248,12 +2252,13 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
                         break;
                 }
 new_group:
+                mutex_unlock(&block_group->alloc_mutex);
+new_group_no_lock:
                 last_wanted = 0;
-                if (loop > 0) {
+                if (!allowed_chunk_alloc && loop > 0) {
                         total_needed -= empty_cluster;
                         empty_cluster = 0;
                 }
-                mutex_unlock(&block_group->alloc_mutex);
                 /*
                  * Here's how this works.
                  * loop == 0: we were searching a block group via a hint
@@ -2271,6 +2276,10 @@ new_group:
                         cur = head->next;
                         loop++;
                 } else if (loop == 1 && cur == head) {
+
+                        total_needed -= empty_cluster;
+                        empty_cluster = 0;
+
                         if (allowed_chunk_alloc && !chunk_alloc_done) {
                                 up_read(&space_info->groups_sem);
                                 ret = do_chunk_alloc(trans, root, num_bytes +