Re: md raid6 oops in 6.6.4 stable

On 12/7/23 09:42, Guoqing Jiang wrote:

Hi,

On 12/7/23 21:55, Genes Lists wrote:

quoted

On 12/7/23 08:30, Bagas Sanjaya wrote:

quoted

On Thu, Dec 07, 2023 at 08:10:04AM -0500, Genes Lists wrote:

quoted

I have not had chance to git bisect this but since it happened in 
stable I
thought it was important to share sooner than later.

One possibly relevant commit between 6.6.3 and 6.6.4 could be:

   commit 2c975b0b8b11f1ffb1ed538609e2c89d8abf800e
   Author: Song Liu [off-list ref]
   Date:   Fri Nov 17 15:56:30 2023 -0800

     md: fix bi_status reporting in md_end_clone_io

log attached shows page_fault_oops.
Machine was up for 3 days before crash happened.

Could you decode the oops (I can't find it in lore for some reason) 
([1])? And
can it be reproduced reliably? If so, pls share the reproduce step.

[1]. https://lwn.net/Articles/592724/

Thanks,
Guoqing

   - reproducing
     An rsync runs 2 x / day. It copies to this server from another. The 
copy is from a (large) top level directory. On the 3rd day after booting 
6.6.4,  the second of these rysnc's triggered the oops. I need to do 
more testing to see if I can reliably reproduce. I have not seen this 
oops on earlier stable kernels.

   - decoding oops with scripts/decode_stacktrace.sh had errors :
    readelf: Error: Not an ELF file - it has the wrong magic bytes at 
the start

    It appears that the decode script doesn't handle compressed modules. 
  I changed the readelf line to decompress first. This fixes the above 
script complaint and the result is attached.

gene