btrfs: Check qgroup level in kernel qgroup assign.

Although we have qgroup level check in btrfs-progs, it's not enough since other programe may still call ioctl directly not using btrfs-progs. For example, systemd. But it's btrfs-progs to be blame since we don't provide a full-function(like subvolume create things) btrfs library with enough check, and only rely on kernel ioctl. So Add level checks in kernel too. Signed-off-by: Qu Wenruo <[email protected]> Reviewed-by: Josef Bacik <[email protected]> Signed-off-by: Chris Mason <[email protected]>
makiko-fly · Apr 13, 2015 · 8465ece · 8465ece
1 parent f5a6b1c
commit 8465ece
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diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
@@ -1061,6 +1061,12 @@ struct btrfs_block_group_item {
 	__le64 flags;
 } __attribute__ ((__packed__));
 
+#define BTRFS_QGROUP_LEVEL_SHIFT		48
+static inline u64 btrfs_qgroup_level(u64 qgroupid)
+{
+	return qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT;
+}
+
 /*
  * is subvolume quota turned on?
  */

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
@@ -1009,6 +1009,10 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
 	struct btrfs_qgroup_list *list;
 	int ret = 0;
 
+	/* Check the level of src and dst first */
+	if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
+		return -EINVAL;
+
 	mutex_lock(&fs_info->qgroup_ioctl_lock);
 	quota_root = fs_info->quota_root;
 	if (!quota_root) {