Re: 2.4.5 + ReiserFS + SMP + umount = oops

[Ed Tomlinson]

Hi,

This was reported on the reiserfs list yesterday.  Seems that the cleanup
applied late in  2.4.5-pre affected the locking of the umount process.  This
was posted to fix the problem.

Ed Tomlinson

-----------------------

"Vladimir V. Saveliev" wrote:
> 
> Hi
> 
> Gergely Tamas wrote:
> > 
> > Hi!
> > 
> > Kernel is 2.4.5
> > 
> > I've tried to unmount a reiserfs device (/uu.new) and got a segfault.
>
> Well, sys_umount in 2.4.5 changed to not lock_kernel() at the beginning and to not unlock_kernel() at the end correspondingly.
> journal_begin expectes kernel locked and it oopses when it is not. Maybe reiserfs_put_super should lock_kernel () itself?
> 

Hi,

You are right.
It seems, the next patch can fix umount reiserfs bug in linux-2.4.5 :

diff -urN v2.4.5/fs/reiserfs/super.c linux/fs/reiserfs/super.c
--- v2.4.5/fs/reiserfs/super.c   Sun Apr 29 16:02:25 2001
+++ linux/fs/reiserfs/super.c    Sat May 26 19:10:16 2001
@@ -104,7 +104,8 @@
 {
   int i;
   struct reiserfs_transaction_handle th ;
-  
+
+  lock_kernel() ;  
   /* change file system state to current state if it was mounted with
read-write permissions */
   if (!(s->s_flags & MS_RDONLY)) {
     journal_begin(&th, s, 10) ;
@@ -117,6 +118,7 @@
   ** to do a journal_end
   */
   journal_release(&th, s) ;
+  unlock_kernel() ;
 
   for (i = 0; i < SB_BMAP_NR (s); i ++)
     brelse (SB_AP_BITMAP (s)[i]);

Thanks,
Yura.