From: Mike Snitzer <snitzer@redhat.com>
To: Joe Thornber <ejt@redhat.com>
Cc: dm-devel@redhat.com
Subject: Re: [PATCH 5/8] [dm-thin] Fix a race condition between discard bios and ordinary bios.
Date: Fri, 14 Dec 2012 10:52:22 -0500 [thread overview]
Message-ID: <20121214155222.GA1145@redhat.com> (raw)
In-Reply-To: <1355429956-22785-6-git-send-email-ejt@redhat.com>
On Thu, Dec 13 2012 at 3:19pm -0500,
Joe Thornber <ejt@redhat.com> wrote:
> The deferred_set entries should not be incremented until the bio
> prison cells are held. Otherwise quiescing a block for discard may
> end up waiting for a bio that's held in the discard bios cell.
This patch's subject and header needs help. We've already fixed the
race with discards and normal bios in an earlier patch:
https://www.redhat.com/archives/dm-devel/2012-December/msg00010.html
This patch is purely about adapting dm-thin to use the new bio-prison
interface where the memory is now passed in rather than using a mempool
in bio-prison. Two preallocated cells are now included in struct
thin_c; this allows the map function to not block performing allocations
(we want to avoid the cell allocation that is done in bio_detain).
The thin_c is allocated once in the constructor (thin_ctr). Because the
thin_c is a shared resource, access to its cells must be serialized
using a new spinlock.
(NOTE: elevating the dm_bio_prison_cell structure from dm-bio-prison.c
to dm-bio-prison.h really should be part of this patch -- rather than
the previous patch).
next prev parent reply other threads:[~2012-12-14 15:52 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-13 20:19 Another cache target Joe Thornber
2012-12-13 20:19 ` [PATCH 1/8] [persistent-data] Fix a bug in btree_del, and another bug that was compensating for it Joe Thornber
2012-12-13 20:19 ` [PATCH 2/8] [persistent-data] dm_btree_walk Joe Thornber
2012-12-13 20:19 ` [PATCH 3/8] [persistent-data] tweak an error message Joe Thornber
2012-12-13 20:19 ` [PATCH 4/8] [dm-bio-prison] Change the bio-prison interface so the memory for the cells is passed in Joe Thornber
2013-01-14 10:02 ` Alasdair G Kergon
2013-01-14 14:06 ` thornber
2013-01-14 14:22 ` Alasdair G Kergon
2013-01-21 23:32 ` Alasdair G Kergon
2013-01-22 11:31 ` thornber
2013-01-22 12:10 ` Alasdair G Kergon
2012-12-13 20:19 ` [PATCH 5/8] [dm-thin] Fix a race condition between discard bios and ordinary bios Joe Thornber
2012-12-14 15:52 ` Mike Snitzer [this message]
2013-01-22 0:03 ` Alasdair G Kergon
2013-01-24 2:35 ` Alasdair G Kergon
2013-01-24 13:23 ` thornber
2013-02-06 0:11 ` Mikulas Patocka
2013-02-07 11:20 ` thornber
2012-12-13 20:19 ` [PATCH 6/8] [persistent-data] Add a transactional array Joe Thornber
2013-01-22 21:18 ` Alasdair G Kergon
2013-01-23 12:07 ` thornber
2013-01-25 20:11 ` Alasdair G Kergon
2013-01-28 13:06 ` thornber
2013-01-28 20:25 ` Alasdair G Kergon
2013-01-28 14:57 ` thornber
2013-01-28 20:22 ` Alasdair G Kergon
2012-12-13 20:19 ` [PATCH 7/8] [persistent-data] transactional bitset Joe Thornber
2013-01-22 21:59 ` Alasdair G Kergon
2012-12-13 20:19 ` [PATCH 8/8] [dm-cache] cache target Joe Thornber
2012-12-14 0:17 ` Darrick J. Wong
2012-12-14 10:09 ` thornber
2013-02-12 15:27 ` Alasdair G Kergon
2013-02-12 16:40 ` Alasdair G Kergon
2013-02-12 17:29 ` Alasdair G Kergon
2013-02-14 13:57 ` Joe Thornber
2013-02-14 14:05 ` Joe Thornber
2013-02-14 21:06 ` Alasdair G Kergon
2012-12-13 21:57 ` Another " Mike Snitzer
2012-12-14 1:16 ` Darrick J. Wong
2012-12-14 2:19 ` Mike Snitzer
2012-12-14 2:27 ` Mike Snitzer
2012-12-14 2:42 ` Darrick J. Wong
2012-12-14 4:23 ` Mike Snitzer
2012-12-14 2:34 ` Darrick J. Wong
2012-12-14 10:24 ` thornber
2012-12-14 12:11 ` thornber
2012-12-14 21:51 ` Darrick J. Wong
2012-12-15 8:23 ` Joe Thornber
2012-12-18 1:49 ` Darrick J. Wong
2012-12-18 2:31 ` Alasdair G Kergon
2013-01-08 0:19 ` Darrick J. Wong
2013-01-08 13:55 ` thornber
2012-12-22 18:50 ` Mark Hills
2012-12-17 16:54 ` Heinz Mauelshagen
2012-12-18 15:44 ` basic cache policy module fix [was: Re: Another cache target] Mike Snitzer
2012-12-20 1:14 ` Darrick J. Wong
2012-12-20 12:57 ` Heinz Mauelshagen
2012-12-20 13:24 ` Mike Snitzer
2012-12-20 16:10 ` Darrick J. Wong
2012-12-20 17:02 ` Heinz Mauelshagen
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