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>

1 files changed, 14 insertions, 4 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index c04f02c7d5bb..9619fb03a5d6 100644
--- 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;