Btrfs: remove BUG_ON()s in btrfs_ioctl_setflags()

We can recover from errors and return -errno to user space.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index c04f02c..9619fb0 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -176,6 +176,8 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
        struct btrfs_trans_handle *trans;
        unsigned int flags, oldflags;
        int ret;
+       u64 ip_oldflags;
+       unsigned int i_oldflags;
 
        if (btrfs_root_readonly(root))
                return -EROFS;
@@ -192,6 +194,9 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 
        mutex_lock(&inode->i_mutex);
 
+       ip_oldflags = ip->flags;
+       i_oldflags = inode->i_flags;
+
        flags = btrfs_mask_flags(inode->i_mode, flags);
        oldflags = btrfs_flags_to_ioctl(ip->flags);
        if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
@@ -250,18 +255,23 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
        }
 
        trans = btrfs_join_transaction(root);
-       BUG_ON(IS_ERR(trans));
+       if (IS_ERR(trans)) {
+               ret = PTR_ERR(trans);
+               goto out_drop;
+       }
 
        btrfs_update_iflags(inode);
        inode->i_ctime = CURRENT_TIME;
        ret = btrfs_update_inode(trans, root, inode);
-       BUG_ON(ret);
 
        btrfs_end_transaction(trans, root);
+ out_drop:
+       if (ret) {
+               ip->flags = ip_oldflags;
+               inode->i_flags = i_oldflags;
+       }
 
        mnt_drop_write(file->f_path.mnt);
-
-       ret = 0;
  out_unlock:
        mutex_unlock(&inode->i_mutex);
        return ret;