autofs - remove autofs dentry mount check

When checking if an autofs mount point is busy it isn't sufficient to
only check if it's a mount point.

For example, if the mount of an offset mountpoint in a tree is denied
for this host by its export and the dentry becomes a process working
directory the check incorrectly returns the mount as not in use at
expire.

This can happen since the default when mounting within a tree is
nostrict, which means ingnore mount fails on mounts within the tree and
continue.  The nostrict option is meant to allow mounting in this case.

Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Jeffery 2013-05-06 13:49:30 +08:00 committed by Linus Torvalds
parent 954829863d
commit ce8a5dbdf9

View File

@ -61,15 +61,6 @@ static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
/* This is an autofs submount, we can't expire it */
if (autofs_type_indirect(sbi->type))
goto done;
/*
* Otherwise it's an offset mount and we need to check
* if we can umount its mount, if there is one.
*/
if (!d_mountpoint(path.dentry)) {
status = 0;
goto done;
}
}
/* Update the expiry counter if fs is busy */