Re: [syzbot] [PATCH] test 305230142ae0

[syzbot <syzbot+4d81015bc10889fd12ea@syzkaller.appspotmail.com>]

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Subject: [PATCH] test 305230142ae0
Author: eadavis@qq.com

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 305230142ae0

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index edb84cc03237..9be5a836c9c0 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -218,6 +218,7 @@ static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
 			p = &(*p)->rb_right;
 		} else {
 			kfree(prealloc);
+			prealloc = NULL;
 			return qgroup;
 		}
 	}
@@ -1697,6 +1698,7 @@ int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
 	struct btrfs_root *quota_root;
 	struct btrfs_qgroup *qgroup;
 	struct btrfs_qgroup *prealloc = NULL;
+	u64 objid;
 	int ret = 0;
 
 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED)
@@ -1727,6 +1729,8 @@ int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
 	spin_lock(&fs_info->qgroup_lock);
 	qgroup = add_qgroup_rb(fs_info, prealloc, qgroupid);
 	spin_unlock(&fs_info->qgroup_lock);
+	while (!prealloc && !btrfs_get_free_objectid(fs_info->tree_root, 
+				&objid) && objid <= qgroupid);
 	prealloc = NULL;
 
 	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
-- 
2.25.1