Btrfs: don't add extent 0 to the free space cache v2
If block group 0 is completely free, btrfs_read_block_groups will
add extent [0, BTRFS_SUPER_INFO_OFFSET) to the free space cache.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 44d7a32..39761ca 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -195,6 +195,14 @@
int stripe_len;
int i, nr, ret;
+ if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
+ stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
+ cache->bytes_super += stripe_len;
+ ret = add_excluded_extent(root, cache->key.objectid,
+ stripe_len);
+ BUG_ON(ret);
+ }
+
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
@@ -255,7 +263,7 @@
if (ret)
break;
- if (extent_start == start) {
+ if (extent_start <= start) {
start = extent_end + 1;
} else if (extent_start > start && extent_start < end) {
size = extent_start - start;