Re: [PATCH] MD: Quickly return errors if too many devices have failed.

[NeilBrown <neilb@suse.de>]

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On Tue, 19 Mar 2013 16:15:35 -0500 Brassow Jonathan <jbrassow@redhat.com>
wrote:

> 
> On Mar 17, 2013, at 6:49 PM, NeilBrown wrote:
> 
> > On Wed, 13 Mar 2013 12:29:24 -0500 Jonathan Brassow <jbrassow@redhat.com>
> > wrote:
> > 
> >> Neil,
> >> 
> >> I've noticed that when too many devices fail in a RAID arrary that
> >> addtional I/O will hang, yielding an endless supply of:
> >> Mar 12 11:52:53 bp-01 kernel: Buffer I/O error on device md1, logical block 3
> >> Mar 12 11:52:53 bp-01 kernel: lost page write due to I/O error on md1
> >> Mar 12 11:52:53 bp-01 kernel: sector=800 i=3           (null)           (null)  
> >>         (null)           (null) 1
> > 
> > This is the third report in as many weeks that mentions that WARN_ON.
> > The first two where quite different causes.
> > I think this one is the same as the first one, which means it would be fixed
> > by  
> >      md/raid5: schedule_construction should abort if nothing to do.
> > 
> > which is commit 29d90fa2adbdd9f in linux-next.
> 
> Sorry, I don't see this commit in linux-next:
> (the "for-next" branch of) git://github.com/neilbrown/linux.git
> or git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> 
> Where should I be looking?

Sorry, I probably messed up.
I meant this commit:
 http://git.neil.brown.name/?p=md.git;a=commitdiff;h=ce7d363aaf1e28be8406a2976220944ca487e8ca


> 
> I did grab a patch from an earlier discussion where you mentioned a similar commit ID.  It didn't solve the problem, but it did prevent an endless progression of the same error messages.  I only saw one instance of the above after the patch.
> 
> I'm fairly certain that the hang was affecting more than just RAID5 though.  It also happened with raid1/10.  I'll go back with 3.9.0-rc3 and make sure that's true until I can figure out which 'linux-next' commit you are talking about.

If you could get something concrete I'd love to hear about it, thanks.

NeilBrown

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