On Fri, Jun 01, 2007 at 11:53:13AM +0200, Miklos Szeredi wrote: > > On Fri, Jun 01, 2007 at 09:49:05AM +0100, Christoph Hellwig wrote: > > > On Fri, Jun 01, 2007 at 10:33:09AM +0200, Karel Zak wrote: > > > > The core of the problem is that HAL doesn't have entries in > > > > /etc/fstab, so you cannot check for "user=" and "users=" by > > > > umount(8). The HAL have enough information about user's privileges, > > > > but the umount(8) knows nothing. > > > > > > Please don't put this in. The last thing we need is more ugly hacks > > > and suid mess in the mount code. Miklos is working towards proper > > > > suid mess? Fortunately, we use external umount programs for all > > network filesystems. > > > > > non-privilegued mounts and you should better support him there. > > > > Yes, I look forward to his patches, but there is still a fstab check > > in umount. The current umount(8) code expects "user" or "users" option > > in /etc/mtab (or in Miklos's /proc/mounts) and *also* in /etc/fstab. > > > > Maybe the umount(8) code is too much paranoid and we needn't the > > fstab check, especially with non-suid umount(2). Miklos's patches > > also add support for "a submount under the owned mount" -- this is > > probably next situation when check against fstab is useless. > > This is a crucial question. The unpriv patches assume, that the owner > can unmount, regardless of what's in fstab. Yes. > The question is: why does umount(8) currently check /etc/fstab? I can I think I found why. See http://git.kernel.org/?p=utils/util-linux-ng/util-linux-ng.git;a=blob;f=mount/umount.c;h=c3cfee71aa0c0072b67a128f0956be6a01f3d4ac;hb=6dbe3af945a63f025561abb83275cee9ff06c57b that's umount(8) from util-linux-2.2 (year 1995). There is fstab check *only*. It seems that there wasn't originally a "user=" option in /etc/mtab... ... around version 2.9 has been added mtab check and "user=" is in fstab and mtab now. IMHO the fstab check is legacy. > imagine, that this is a sort of sanity check, if the mount is really > the same as it was (hasn't been moved, remounted, umounted etc). > > In this case it's OK to get rid of this check, since the kernel will > know if something happened to the mount. Yes. Karel -- Karel Zak <kzak@xxxxxxxxxx> - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
