Btrfs: Fix extent allocation for btree blocks as the disk fills

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 17 insertions, 11 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 91397e989393..8ab4954f6ad0 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -172,9 +172,7 @@ static u64 find_search_start(struct btrfs_root *root,
         int wrapped = 0;
 
         if (!cache) {
-                cache = btrfs_lookup_block_group(root->fs_info, search_start);
-                if (!cache)
-                        return search_start;
+                goto out;
         }
 again:
         ret = cache_block_group(root, cache);
@@ -205,6 +203,13 @@ again:
                 return start;
         }
 out:
+        cache = btrfs_lookup_block_group(root->fs_info, search_start);
+        if (!cache) {
+                printk("Unable to find block group for %Lu\n",
+                       search_start);
+                WARN_ON(1);
+                return search_start;
+        }
         return search_start;
 
 new_group:
@@ -219,15 +224,14 @@ no_cache:
                         data = BTRFS_BLOCK_GROUP_MIXED;
                         goto wrapped;
                 }
-                return search_start;
+                goto out;
         }
         if (cache_miss && !cache->cached) {
                 cache_block_group(root, cache);
                 last = cache_miss;
                 cache = btrfs_lookup_block_group(root->fs_info, last);
         }
-        if (!full_scan)
-                cache = btrfs_find_block_group(root, cache, last, data, 0);
+        cache = btrfs_find_block_group(root, cache, last, data, 0);
         if (!cache)
                 goto no_cache;
         *cache_ret = cache;
@@ -985,12 +989,14 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
                 search_end = btrfs_super_total_bytes(&info->super_copy);
         if (hint_byte) {
                 block_group = btrfs_lookup_block_group(info, hint_byte);
+                if (!block_group)
+                        hint_byte = search_start;
                 block_group = btrfs_find_block_group(root, block_group,
                                                      hint_byte, data, 1);
         } else {
                 block_group = btrfs_find_block_group(root,
-                                                     trans->block_group, 0,
-                                                     data, 1);
+                                                     trans->block_group,
+                                                     search_start, data, 1);
         }
 
         total_needed += empty_size;
@@ -1159,14 +1165,14 @@ enospc:
                         if (!full_scan)
                                 total_needed -= empty_size;
                         full_scan = 1;
+                        data = BTRFS_BLOCK_GROUP_MIXED;
                 } else
                         wrapped = 1;
         }
         block_group = btrfs_lookup_block_group(info, search_start);
         cond_resched();
-        if (!full_scan)
-                block_group = btrfs_find_block_group(root, block_group,
-                                                     search_start, data, 0);
+        block_group = btrfs_find_block_group(root, block_group,
+                                             search_start, data, 0);
         goto check_failed;
 
 error: