2.4.23aa1 ext3 oops

[Jamie Clark]

OK, no deadlock yet with 2.4.23aa1 however it oopsed under 
ext3_file_write() in __mark_inode_dirty().

Just to recap: this test is dual PIII, running several bonnie++ loads on 
an ext3+noatime+quota filesystem
mounted off

From the oops the fault happens on the last instruction of:

       movl $0,8(%ebx)
       movl $0,4(%edx)
       movl 100(%edi),%eax 
       movl %edx,4(%eax)    <-- here

which appears to be this code in inode.c  [line 221+]

               if (!(inode->i_state & (I_LOCK|I_FREEING|I_CLEAR)) &&
                   !list_empty(&inode->i_hash)) {
                       list_del(&inode->i_list);
                       list_add(&inode->i_list, &sb->s_dirty);

After a quick browse of the assembler output the zeroing would appear to 
be part of the list_del inline,
and edi seems to equate to &sb. If I have read that correctly then the 
oops happens at the beginning of
the list_add() inline and eax is the head of the s_dirty list - pointing 
into oblivion.

__mark_inode_dirty() does not appear to take sb_lock before adding to 
the s_dirty list. Could that
be the culprit?   I'm completely unfamiliar with linux kernel so I might 
be way off here.

-Jamie

Andrea Arcangeli wrote:

> On Tue, Nov 04, 2003 at 07:52:40PM +0800, Jamie Clark wrote:
>  
>
> > I made the quick fix (disabling rq_mergeable) and started the load test.
> > Will let it run for a week or so.
> >    
>
> does your later recent email means it deadlocked again even with this
> disabled?
>
> Could you try again with 2.4.23aa1 again just in case?
>
>  
>
> > FYI an observation from my last test: the read latency seems to be much
> > improved and more consistent under this kernel (2.4.23pre6aa3, before
> > the oops and before this fix).  The maximum latency seemed steady over
> > the whole test without any of the longish pauses that showed up under
> > 2.4.19. Quite a difference.
> >    
>
> nice to hear! thanks.
>  
ksymoops 2.4.5 on i686 2.4.23aa1.  Options used
     -V (default)
     -k /proc/ksyms (default)
     -l /proc/modules (default)
     -o /lib/modules/2.4.23aa1/ (default)
     -m /boot/System.map-2.4.23aa1 (default)

Warning: You did not tell me where to find symbol information.  I will
assume that the log matches the kernel and modules that are running
right now and I'll use the default options above for symbol resolution.
If the current kernel and/or modules do not match the log, you can get
more accurate output by telling me the kernel version and where to find
map, modules, ksyms etc.  ksymoops -h explains the options.

Unable to handle kernel paging request at virtual address d7ffbc0c
c0156eaf
*pde = 17c001e3
Oops: 0002 2.4.23aa1 #2 SMP Sat Dec 6 10:58:56 SGT 2003
CPU:    0
EIP:    0010:[<c0156eaf>]    Not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00010287
eax: d7ffbc08   ebx: e2ae6a00   ecx: c02a11f8   edx: e2ae6a08
esi: 00000001   edi: f769e000   ebp: 00002000   esp: f2799ef8
ds: 0018   es: 0018   ss: 0018
Process bonnie++ (pid: 330, stackpage=f2799000)
Stack: e2ae6a00 e2ae6a00 f5110420 c0130973 e2ae6a00 00000001 e2ae6a6c e2ae6a00
       f5110420 00002000 e2ae6a00 ffffffeb f785d660 c014bf57 e2ae6a00 00000000
       00000000 e2ae6a00 e2ae6ac4 00000000 00000000 00000000 f5110420 c013108f
Call Trace:         [<c0130973>] (40) [<c014bf57>] (40) [<c013108f>] (36) [<c016f377>] (36) [<c0140e57>] (36) [<c0107133>] (60)
Code: 89 50 04 89 43 08 8d 47 64 89 42 04 89 57 64 c6 05 10 12 2a


>>EIP; c0156eaf <__mark_inode_dirty+93/b0>   <=====

>>eax; d7ffbc08 <END_OF_CODE+1462abd5/????>
>>ebx; e2ae6a00 <END_OF_CODE+1f1159cd/????>
>>ecx; c02a11f8 <inode_in_use+0/8>
>>edx; e2ae6a08 <END_OF_CODE+1f1159d5/????>
>>edi; f769e000 <END_OF_CODE+33cccfcd/????>
>>ebp; 00002000 Before first symbol
>>esp; f2799ef8 <END_OF_CODE+2edc8ec5/????>

Trace; c0130973 <generic_file_write_nolock+d3/4c8>
Trace; c014bf57 <permission+7b/84>
Trace; c013108f <generic_file_write+13f/158>
Trace; c016f377 <ext3_file_write+23/bc>
Trace; c0140e57 <sys_write+8f/100>
Trace; c0107133 <system_call+33/38>

Code;  c0156eaf <__mark_inode_dirty+93/b0>
00000000 <_EIP>:
Code;  c0156eaf <__mark_inode_dirty+93/b0>   <=====
   0:   89 50 04                  mov    %edx,0x4(%eax)   <=====
Code;  c0156eb2 <__mark_inode_dirty+96/b0>
   3:   89 43 08                  mov    %eax,0x8(%ebx)
Code;  c0156eb5 <__mark_inode_dirty+99/b0>
   6:   8d 47 64                  lea    0x64(%edi),%eax
Code;  c0156eb8 <__mark_inode_dirty+9c/b0>
   9:   89 42 04                  mov    %eax,0x4(%edx)
Code;  c0156ebb <__mark_inode_dirty+9f/b0>
   c:   89 57 64                  mov    %edx,0x64(%edi)
Code;  c0156ebe <__mark_inode_dirty+a2/b0>
   f:   c6 05 10 12 2a 00 00      movb   $0x0,0x2a1210


1 warning issued.  Results may not be reliable.