Btrfs: Fix per root used space accounting
The bytes_used field in root item was originally planned to
trace the amount of used data and tree blocks. But it never
worked right since we can't trace freeing of data accurately.
This patch changes it to only trace the amount of tree blocks.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 75b31ca..b2acc79 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -501,13 +501,16 @@
{
int ret;
u64 old_root_bytenr;
+ u64 old_root_used;
struct btrfs_root *tree_root = root->fs_info->tree_root;
+ old_root_used = btrfs_root_used(&root->root_item);
btrfs_write_dirty_block_groups(trans, root);
while (1) {
old_root_bytenr = btrfs_root_bytenr(&root->root_item);
- if (old_root_bytenr == root->node->start)
+ if (old_root_bytenr == root->node->start &&
+ old_root_used == btrfs_root_used(&root->root_item))
break;
btrfs_set_root_node(&root->root_item, root->node);
@@ -516,6 +519,7 @@
&root->root_item);
BUG_ON(ret);
+ old_root_used = btrfs_root_used(&root->root_item);
ret = btrfs_write_dirty_block_groups(trans, root);
BUG_ON(ret);
}