Make sure all dirty blocks are written at commit time

Write dirty block groups may make some block groups dirty.
This patch make btrfs_write_dirty_block_groups properly
handle the recursion.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/extent-tree.c b/extent-tree.c
index 6bc1cc8..3ec57fa 100644 (file)
--- a/extent-tree.c
+++ b/extent-tree.c
@@ -1697,8 +1697,6 @@ int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
        struct extent_io_tree *block_group_cache;
        struct btrfs_block_group_cache *cache;
        int ret;
-       int err = 0;
-       int werr = 0;
        struct btrfs_path *path;
        u64 last = 0;
        u64 start;
@@ -1713,30 +1711,26 @@ int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
        while(1) {
                ret = find_first_extent_bit(block_group_cache, last,
                                            &start, &end, BLOCK_GROUP_DIRTY);
-               if (ret)
-                       break;
+               if (ret) {
+                       if (last == 0)
+                               break;
+                       last = 0;
+                       continue;
+               }
 
                last = end + 1;
                ret = get_state_private(block_group_cache, start, &ptr);
-               if (ret)
-                       break;
-               cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
-               err = write_one_cache_group(trans, root,
-                                           path, cache);
-               /*
-                * if we fail to write the cache group, we want
-                * to keep it marked dirty in hopes that a later
-                * write will work
-                */
-               if (err) {
-                       werr = err;
-                       continue;
-               }
+               BUG_ON(ret);
+
                clear_extent_bits(block_group_cache, start, end,
                                  BLOCK_GROUP_DIRTY, GFP_NOFS);
+
+               cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
+               ret = write_one_cache_group(trans, root, path, cache);
+               BUG_ON(ret);
        }
        btrfs_free_path(path);
-       return werr;
+       return 0;
 }
 
 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,