On Sunday February 16, qralston+ml.linux-raid@andrew.cmu.edu wrote: > On 2003-02-17 at 09:09:53+1100 Neil Brown <neilb@cse.unsw.edu.au> wrote: > > > > https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=82815 > > > > I think that bug should be fixed by the follow patch which has been > > submitted and accepted and should be in 2.4.21. > > I already tried backporting the md driver from 2.4.21-pre3 (which > contains the patch you included). Unfortunately, not only does it not > fix the problem, but it makes it worse: with the patch applied, after > the Oops occurs, touching the md device in any way hangs. This > includes the "md: stopping all md devices" which occurs at shutdown, > so as a result, at shutdown, the entire machine hangs, and you have to > go physically reset or power cycle the machine. > > I've appended the Oops I generated using the md driver from > 2.4.21-pre3 in Red Hat's kernel-2.4.18-19.8.0. This is how I produced > it: > > $ mdadm --create /dev/md0 --verbose --level=mirror --raid-devices=2 /dev/sdb1 /dev/sdc1 > <wait for sync> > $ mdadm /dev/md0 -f /dev/sdc1 -r /dev/sdc1 -a /dev/sdc1 > <wait for sync> > $ mdadm /dev/md0 -f /dev/sdb1 -r /dev/sdb1 -a /dev/sdb1 > <mdrecovery generates Oops> > > As I said before, I'm at a loss to figure out where the bug is, but if > you have any further things to try, I'd be happy to give them a > whirl... Hmmm... you can probasbly alleviate the symptoms with: diff ./drivers/md/md.c~current~ ./drivers/md/md.c --- ./drivers/md/md.c~current~ 2003-02-17 13:24:11.000000000 +1100 +++ ./drivers/md/md.c 2003-02-17 13:24:59.000000000 +1100 @@ -1048,7 +1048,7 @@ repeat: printk("(skipping faulty "); if (rdev->alias_device) printk("(skipping alias "); - if (disk_faulty(&rdev->sb->this_disk)) { + if (!rdev->faulty && disk_faulty(&rdev->sb->this_disk)) { printk("(skipping new-faulty %s )\n", partition_name(rdev->dev)); continue; but the real problem is a lack of locking. A lot of work went into 2.5 to get the locking right in the md driver and it resulted in a substantial shake-up of the code. I do have a patch that does better locking for 2.4, but it is rather ugly.... maybe I should revisit it. NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
