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/extent-tree.c b/fs/btrfs/extent-tree.c
index fcdccfa..44d7a32 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3454,14 +3454,6 @@
else
old_val -= num_bytes;
btrfs_set_super_bytes_used(&info->super_copy, old_val);
-
- /* block accounting for root item */
- old_val = btrfs_root_used(&root->root_item);
- if (alloc)
- old_val += num_bytes;
- else
- old_val -= num_bytes;
- btrfs_set_root_used(&root->root_item, old_val);
spin_unlock(&info->delalloc_lock);
while (total) {
@@ -4049,6 +4041,21 @@
return ret;
}
+int btrfs_free_tree_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 bytenr, u32 blocksize,
+ u64 parent, u64 root_objectid, int level)
+{
+ u64 used;
+ spin_lock(&root->node_lock);
+ used = btrfs_root_used(&root->root_item) - blocksize;
+ btrfs_set_root_used(&root->root_item, used);
+ spin_unlock(&root->node_lock);
+
+ return btrfs_free_extent(trans, root, bytenr, blocksize,
+ parent, root_objectid, level, 0);
+}
+
static u64 stripe_align(struct btrfs_root *root, u64 val)
{
u64 mask = ((u64)root->stripesize - 1);
@@ -4897,6 +4904,14 @@
extent_op);
BUG_ON(ret);
}
+
+ if (root_objectid == root->root_key.objectid) {
+ u64 used;
+ spin_lock(&root->node_lock);
+ used = btrfs_root_used(&root->root_item) + num_bytes;
+ btrfs_set_root_used(&root->root_item, used);
+ spin_unlock(&root->node_lock);
+ }
return ret;
}