Btrfs: do not overwrite error return value in the device replace ioctl

If the call to btrfs_dev_replace_by_ioctl() failed we would overwrite the
error returned to user space with -EFAULT if the call to copy_to_user()
failed as well. Fix that by calling copy_to_user() only if no error
happened before or a device replace operation was canceled.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Filipe Manana 2019-01-08 11:42:09 +00:00 committed by David Sterba
parent 0f39b60563
commit d3a53286c1

View file

@ -4475,7 +4475,7 @@ static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
break;
}
if (copy_to_user(arg, p, sizeof(*p)))
if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
ret = -EFAULT;
out:
kfree(p);