On Fri 12-02-21 09:38:35, Sascha Hauer wrote:

On Thu, Feb 11, 2021 at 03:38:13PM +0000, Christoph Hellwig wrote:

quoted

quoted

+	if (!mountpoint)
+		return -ENODEV;
+
+	ret = user_path_at(AT_FDCWD, mountpoint,
+			     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);

user_path_at handles an empty path, although you'll get EFAULT instead.
Do we care about the -ENODEV here?

The quotactl manpage documents EFAULT as error code for invalid addr or
special argument, so we really should return -EFAULT here.

Existing quotactl gets this wrong as well:

	if (!special) {
		if (cmds == Q_SYNC)
			return quota_sync_all(type);
		return -ENODEV;
	}

Should we fix this or is there userspace code that is confused by a changed
return value?

I'd leave the original quotactl(2) as is. There's no strong reason to risk
breaking some userspace. For the new syscall, I agree we can just
standardize the return value, there ENODEV makes even less sense since
there's no device in that call.

								Honza

-- 
Jan Kara [off-list ref]
SUSE Labs, CR