SELinux: don't BUG if fs reuses a superblock

I (wrongly) assumed that nfs_xdev_get_sb() would not ever share a superblock
and so cloning mount options would always be correct.  Turns out that isn't
the case and we could fall over a BUG_ON() that wasn't a BUG at all.  Since
there is little we can do to reconcile different mount options this patch
just leaves the sb alone and the first set of options wins.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
Eric Paris 2008-04-09 14:08:35 -04:00 committed by James Morris
parent 7180c4c9e0
commit 5a55261716

View File

@ -760,13 +760,13 @@ static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
* this early in the boot process. */
BUG_ON(!ss_initialized);
/* this might go away sometime down the line if there is a new user
* of clone, but for now, nfs better not get here... */
BUG_ON(newsbsec->initialized);
/* how can we clone if the old one wasn't set up?? */
BUG_ON(!oldsbsec->initialized);
/* if fs is reusing a sb, just let its options stand... */
if (newsbsec->initialized)
return;
mutex_lock(&newsbsec->lock);
newsbsec->flags = oldsbsec->flags;