btrfs: qgroup: Add the ability to skip given qgroup for old/new_roots.

This is used by later qgroup fix patches for snapshot.

As current snapshot accounting is done by btrfs_qgroup_inherit(), but
new extent oriented quota mechanism will account extent from
btrfs_copy_root() and other snapshot things, causing wrong result.

So add this ability to handle snapshot accounting.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index 4016f963599e..13fb5e6090fe 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -175,6 +175,14 @@ struct btrfs_delayed_ref_root {
         int flushing;
 
         u64 run_delayed_start;
+
+        /*
+         * To make qgroup to skip given root.
+         * This is for snapshot, as btrfs_qgroup_inherit() will manully
+         * modify counters for snapshot and its source, so we should skip
+         * the snapshot in new_root/old_roots or it will get calculated twice
+         */
+        u64 qgroup_to_skip;
 };
 
 extern struct kmem_cache *btrfs_delayed_ref_head_cachep;