Re: BUG: Mount ignores mount options

On 2018/08/10 23:05, Eric W. Biederman wrote:

There is a serious problem with mount options today that fsopen does not
address.  The problem is that mount options are ignored for block based
filesystems, and any other type of filesystem that follows the same
pattern.

The script below demonstrates this bug.  Showing this bug can cause the
ext4 "acl" "quota" and "user_xattr" options to be silently ignored.

fsopen has my nack until it addresses this issue.

I don't know if we can fix this in the context of sys_mount.  But we if
we are redoing the option parsing of how we mount filesystems this needs
to be fixed before we start worrying about bug compatibility.

Hopefully this report is simple and clear enough that we can at least
agree on the problem.

Eric

This might be related to a problem that syzbot is failing to reproduce a problem.

  https://groups.google.com/forum/#!msg/syzkaller-bugs/R03vI7RCVco/0PijCTrcCgAJ

  syzbot found a reproducer, and the reproducer was working until next-20180803.
  But the reproducer is failing to reproduce this problem in next-20180806 despite
  there is no mm related change between next-20180803 and next-20180806.

  Therefore, I suspect that the reproducer is no longer working as intended. And
  there was parser change (David Howells' patch) between next-20180803 and next-20180806.

I'm waiting for response from David Howells...