btrfs: qgroup: Introduce new functions to reserve/free metadata
Introduce new functions btrfs_qgroup_reserve/free_meta() to reserve/free
metadata reserved space.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 75d8e58..897a49d 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2594,3 +2594,43 @@
{
return __btrfs_qgroup_release_data(inode, start, len, 0);
}
+
+int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes)
+{
+ int ret;
+
+ if (!root->fs_info->quota_enabled || !is_fstree(root->objectid) ||
+ num_bytes == 0)
+ return 0;
+
+ BUG_ON(num_bytes != round_down(num_bytes, root->nodesize));
+ ret = btrfs_qgroup_reserve(root, num_bytes);
+ if (ret < 0)
+ return ret;
+ atomic_add(num_bytes, &root->qgroup_meta_rsv);
+ return ret;
+}
+
+void btrfs_qgroup_free_meta_all(struct btrfs_root *root)
+{
+ int reserved;
+
+ if (!root->fs_info->quota_enabled || !is_fstree(root->objectid))
+ return;
+
+ reserved = atomic_xchg(&root->qgroup_meta_rsv, 0);
+ if (reserved == 0)
+ return;
+ btrfs_qgroup_free(root, reserved);
+}
+
+void btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes)
+{
+ if (!root->fs_info->quota_enabled || !is_fstree(root->objectid))
+ return;
+
+ BUG_ON(num_bytes != round_down(num_bytes, root->nodesize));
+ WARN_ON(atomic_read(&root->qgroup_meta_rsv) < num_bytes);
+ atomic_sub(num_bytes, &root->qgroup_meta_rsv);
+ btrfs_qgroup_free(root, num_bytes);
+}