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

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

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 91397e989393d10b3a22814c2034a3d8af3c8514..8ab4954f6ad0b73f7278f21194ce2da8325cd865 100644 (file)
--- 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: