From: Nix <nix@esperi.org.uk>
To: Wols Lists <antlists@youngman.org.uk>
Cc: NeilBrown <neilb@suse.com>, linux-raid@vger.kernel.org
Subject: Re: 4.11.2: reshape raid5 -> raid6 atop bcache deadlocks at start on md_attr_store / raid5_make_request
Date: Tue, 23 May 2017 16:00:37 +0100 [thread overview]
Message-ID: <87r2zfvcru.fsf@esperi.org.uk> (raw)
In-Reply-To: <59244428.4050001@youngman.org.uk> (Wols Lists's message of "Tue, 23 May 2017 15:16:08 +0100")
On 23 May 2017, Wols Lists told this:
> On 22/05/17 22:38, Nix wrote:
>> Everything else hangs the same way, too. This was surprising enough that
>> I double-checked to be sure the patch was applied: it was. I suspect the
>> deadlock is somewhat different than you supposed... (and quite possibly
>> not a race at all, or I wouldn't be hitting it so consistently, every
>> time. I mean, I only need to miss it *once* and I'll have reshaped... :) )
>>
>> It seems I can reproduce this on demand, so if you want to throw a patch
>> with piles of extra printks my way, feel free.
>
> Could this be the long-standing bug that hangs raid5 and raid6 reshapes?
> I don't remember it being found and fixed. iirc (it's too long ago) it
> hit people adding a drive to a raid5 (occasionally a raid6), and was
> fairly easy to get round. Again it's too long ago but stopping and
> starting the reshape fixed it usually iirc.
It hangs access to the whole drive irretrievably, immediately on
starting the reshape (it can't happen at any later time because it is
associated with writing out the level change itself: thank goodness, it
happens *before* the write, not afterwards). I don't know if the hangs
you refer to have similar symptoms.
--
NULL && (void)
next prev parent reply other threads:[~2017-05-23 15:00 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-22 9:13 4.11.2: reshape raid5 -> raid6 atop bcache deadlocks at start on md_attr_store / raid5_make_request Nix
2017-05-22 11:35 ` NeilBrown
2017-05-22 15:30 ` Nix
2017-05-22 19:07 ` Wols Lists
2017-05-22 20:43 ` Nix
2017-05-23 1:20 ` NeilBrown
2017-05-23 10:10 ` Nix
2017-05-23 1:39 ` NeilBrown
2017-05-23 14:47 ` Wols Lists
2017-05-24 1:50 ` NeilBrown
2017-05-23 1:07 ` NeilBrown
2017-05-22 21:38 ` Nix
2017-05-23 14:16 ` Wols Lists
2017-05-23 15:00 ` Nix [this message]
2017-05-24 1:24 ` NeilBrown
2017-05-24 13:28 ` Nix
2017-05-25 1:31 ` NeilBrown
2017-05-25 12:14 ` Nix
2017-05-24 19:42 ` Nix
2017-05-24 22:57 ` Shaohua Li
2017-05-25 1:30 ` NeilBrown
2017-05-25 1:46 ` Shaohua Li
2017-05-26 3:23 ` NeilBrown
2017-05-26 16:40 ` Shaohua Li
2017-05-28 23:17 ` NeilBrown
2017-05-30 17:41 ` Shaohua Li
2017-06-05 6:49 ` [PATCH] md: fix deadlock between mddev_suspend() and md_write_start() NeilBrown
2017-06-06 0:01 ` Shaohua Li
2017-06-07 1:45 ` NeilBrown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87r2zfvcru.fsf@esperi.org.uk \
--to=nix@esperi.org.uk \
--cc=antlists@youngman.org.uk \
--cc=linux-raid@vger.kernel.org \
--cc=neilb@suse.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.