Btrfs: bail out if block group has different mixed flag

Currently we allow inconsistence about mixed flag (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA). We'd get ENOSPC if block group has mixed flag and btrfs doesn't. If that happens, we have one space_info with mixed flag and another space_info only with BTRFS_BLOCK_GROUP_METADATA, and global_block_rsv.space_info points to the latter one, but all bytes from block_group contributes to the mixed space_info, thus all the allocation will fail with ENOSPC. This adds a check for the above case. Reported-by: Vegard Nossum <[email protected]> Signed-off-by: Liu Bo <[email protected]> [ updated message ] Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>
redbrain17 · Sep 26, 2016 · 4930338 · 4930338
1 parent 2571e73
commit 4930338
Showing 1 changed file with 14 additions and 0 deletions.
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
@@ -10129,6 +10129,11 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 	struct extent_buffer *leaf;
 	int need_clear = 0;
 	u64 cache_gen;
+	u64 feature;
+	int mixed;
+
+	feature = btrfs_super_incompat_flags(info->super_copy);
+	mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS);
 
 	root = info->extent_root;
 	key.objectid = 0;
@@ -10182,6 +10187,15 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 				   btrfs_item_ptr_offset(leaf, path->slots[0]),
 				   sizeof(cache->item));
 		cache->flags = btrfs_block_group_flags(&cache->item);
+		if (!mixed &&
+		    ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
+		    (cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
+			btrfs_err(info,
+"bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups",
+				  cache->key.objectid);
+			ret = -EINVAL;
+			goto error;
+		}
 
 		key.objectid = found_key.objectid + found_key.offset;
 		btrfs_release_path(path);