* [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove
@ 2019-02-12 20:07 John Snow
2019-02-12 20:16 ` Eric Blake
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: John Snow @ 2019-02-12 20:07 UTC (permalink / raw)
To: qemu-block, qemu-devel
Cc: Kevin Wolf, vsementsov, Max Reitz, pbonzini, eblake,
Markus Armbruster, John Snow
When bitmaps are persistent, they may incur a disk read or write when bitmaps
are added or removed. For configurations like virtio-dataplane, failing to
acquire this lock will abort QEMU when disk IO occurs.
We used to acquire aio_context as part of the bitmap lookup, so re-introduce
the lock for just the cases that have an IO penalty.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1672010
Reported-By: Aihua Liang <aliang@redhat.com>
---
blockdev.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index fb18e9c975..790b0e0ac8 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2820,6 +2820,7 @@ void qmp_block_dirty_bitmap_add(const char *node, const char *name,
{
BlockDriverState *bs;
BdrvDirtyBitmap *bitmap;
+ AioContext *aio_context = NULL;
if (!name || name[0] == '\0') {
error_setg(errp, "Bitmap name cannot be empty");
@@ -2854,15 +2855,17 @@ void qmp_block_dirty_bitmap_add(const char *node, const char *name,
disabled = false;
}
- if (persistent &&
- !bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp))
- {
- return;
+ if (persistent) {
+ aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(aio_context);
+ if (!bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp)) {
+ goto out;
+ }
}
bitmap = bdrv_create_dirty_bitmap(bs, granularity, name, errp);
if (bitmap == NULL) {
- return;
+ goto out
}
if (disabled) {
@@ -2870,6 +2873,10 @@ void qmp_block_dirty_bitmap_add(const char *node, const char *name,
}
bdrv_dirty_bitmap_set_persistance(bitmap, persistent);
+ out:
+ if (aio_context) {
+ aio_context_release(aio_context);
+ }
}
void qmp_block_dirty_bitmap_remove(const char *node, const char *name,
@@ -2878,6 +2885,7 @@ void qmp_block_dirty_bitmap_remove(const char *node, const char *name,
BlockDriverState *bs;
BdrvDirtyBitmap *bitmap;
Error *local_err = NULL;
+ AioContext *aio_context = NULL;
bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
if (!bitmap || !bs) {
@@ -2892,14 +2900,20 @@ void qmp_block_dirty_bitmap_remove(const char *node, const char *name,
}
if (bdrv_dirty_bitmap_get_persistance(bitmap)) {
+ aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(aio_context);
bdrv_remove_persistent_dirty_bitmap(bs, name, &local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
- return;
+ goto out;
}
}
bdrv_release_dirty_bitmap(bs, bitmap);
+ out:
+ if (aio_context) {
+ aio_context_release(aio_context);
+ }
}
/**
--
2.17.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove
2019-02-12 20:07 [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove John Snow
@ 2019-02-12 20:16 ` Eric Blake
2019-02-12 21:37 ` John Snow
2019-02-13 16:41 ` no-reply
2019-02-14 4:26 ` no-reply
2 siblings, 1 reply; 6+ messages in thread
From: Eric Blake @ 2019-02-12 20:16 UTC (permalink / raw)
To: John Snow, qemu-block, qemu-devel
Cc: Kevin Wolf, vsementsov, Max Reitz, pbonzini, Markus Armbruster
[-- Attachment #1: Type: text/plain, Size: 1006 bytes --]
On 2/12/19 2:07 PM, John Snow wrote:
> When bitmaps are persistent, they may incur a disk read or write when bitmaps
> are added or removed. For configurations like virtio-dataplane, failing to
> acquire this lock will abort QEMU when disk IO occurs.
>
> We used to acquire aio_context as part of the bitmap lookup, so re-introduce
> the lock for just the cases that have an IO penalty.
It would be nice to call out which commit id dropped the aio_context
acquisition during bitmap lookup (making it easier to analyze how long
this has broken, and which downstream builds need the backport.
>
> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1672010
> Reported-By: Aihua Liang <aliang@redhat.com>
> ---
> blockdev.c | 26 ++++++++++++++++++++------
> 1 file changed, 20 insertions(+), 6 deletions(-)
Reviewed-by: Eric Blake <eblake@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove
2019-02-12 20:16 ` Eric Blake
@ 2019-02-12 21:37 ` John Snow
2019-02-12 22:04 ` Eric Blake
0 siblings, 1 reply; 6+ messages in thread
From: John Snow @ 2019-02-12 21:37 UTC (permalink / raw)
To: Eric Blake, qemu-block, qemu-devel
Cc: Kevin Wolf, pbonzini, vsementsov, Markus Armbruster, Max Reitz
On 2/12/19 3:16 PM, Eric Blake wrote:
> On 2/12/19 2:07 PM, John Snow wrote:
>> When bitmaps are persistent, they may incur a disk read or write when bitmaps
>> are added or removed. For configurations like virtio-dataplane, failing to
>> acquire this lock will abort QEMU when disk IO occurs.
>>
>> We used to acquire aio_context as part of the bitmap lookup, so re-introduce
>> the lock for just the cases that have an IO penalty.
>
> It would be nice to call out which commit id dropped the aio_context
> acquisition during bitmap lookup (making it easier to analyze how long
> this has broken, and which downstream builds need the backport.
>
OK, I will amend this.
Looks like:
commit 2119882c7eb7e2c612b24fc0c8d86f5887d6f1c3
Author: Paolo Bonzini <pbonzini@redhat.com>
Date: Mon Jun 5 14:39:03 2017 +0200
since 2.10.
>>
>> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1672010
>> Reported-By: Aihua Liang <aliang@redhat.com>
>> ---
>> blockdev.c | 26 ++++++++++++++++++++------
>> 1 file changed, 20 insertions(+), 6 deletions(-)
>
> Reviewed-by: Eric Blake <eblake@redhat.com>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove
2019-02-12 21:37 ` John Snow
@ 2019-02-12 22:04 ` Eric Blake
0 siblings, 0 replies; 6+ messages in thread
From: Eric Blake @ 2019-02-12 22:04 UTC (permalink / raw)
To: John Snow, qemu-block, qemu-devel
Cc: Kevin Wolf, pbonzini, vsementsov, Markus Armbruster, Max Reitz
[-- Attachment #1: Type: text/plain, Size: 1318 bytes --]
On 2/12/19 3:37 PM, John Snow wrote:
>
>
> On 2/12/19 3:16 PM, Eric Blake wrote:
>> On 2/12/19 2:07 PM, John Snow wrote:
>>> When bitmaps are persistent, they may incur a disk read or write when bitmaps
>>> are added or removed. For configurations like virtio-dataplane, failing to
>>> acquire this lock will abort QEMU when disk IO occurs.
>>>
>>> We used to acquire aio_context as part of the bitmap lookup, so re-introduce
>>> the lock for just the cases that have an IO penalty.
>>
>> It would be nice to call out which commit id dropped the aio_context
>> acquisition during bitmap lookup (making it easier to analyze how long
>> this has broken, and which downstream builds need the backport.
>>
>
> OK, I will amend this.
>
> Looks like:
>
> commit 2119882c7eb7e2c612b24fc0c8d86f5887d6f1c3
> Author: Paolo Bonzini <pbonzini@redhat.com>
> Date: Mon Jun 5 14:39:03 2017 +0200
>
> since 2.10.
Hmm. block-dirty-bitmap-add's "persistent":true parameter was also added
in 2.10 in commit fd5ae4cc. In fact, 2119882c was made at a time when
there were not persistent bitmaps; so I guess that this means we have
always been broken since fd5ae4cc.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove
2019-02-12 20:07 [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove John Snow
2019-02-12 20:16 ` Eric Blake
@ 2019-02-13 16:41 ` no-reply
2019-02-14 4:26 ` no-reply
2 siblings, 0 replies; 6+ messages in thread
From: no-reply @ 2019-02-13 16:41 UTC (permalink / raw)
To: jsnow
Cc: fam, qemu-block, qemu-devel, kwolf, vsementsov, armbru, mreitz, pbonzini
Patchew URL: https://patchew.org/QEMU/20190212200750.27521-1-jsnow@redhat.com/
Hi,
This series seems to have some coding style problems. See output below for
more information:
Subject: [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove
Type: series
Message-id: 20190212200750.27521-1-jsnow@redhat.com
=== TEST SCRIPT BEGIN ===
#!/bin/bash
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===
Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
From https://github.com/patchew-project/qemu
* [new tag] patchew/20190212200750.27521-1-jsnow@redhat.com -> patchew/20190212200750.27521-1-jsnow@redhat.com
Switched to a new branch 'test'
b3b11e3e6f blockdev: acquire aio_context for bitmap add/remove
=== OUTPUT BEGIN ===
ERROR: Missing Signed-off-by: line(s)
total: 1 errors, 0 warnings, 67 lines checked
Commit b3b11e3e6f40 (blockdev: acquire aio_context for bitmap add/remove) has style problems, please review. If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
=== OUTPUT END ===
Test command exited with code: 1
The full log is available at
http://patchew.org/logs/20190212200750.27521-1-jsnow@redhat.com/testing.checkpatch/?type=message.
---
Email generated automatically by Patchew [http://patchew.org/].
Please send your feedback to patchew-devel@redhat.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove
2019-02-12 20:07 [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove John Snow
2019-02-12 20:16 ` Eric Blake
2019-02-13 16:41 ` no-reply
@ 2019-02-14 4:26 ` no-reply
2 siblings, 0 replies; 6+ messages in thread
From: no-reply @ 2019-02-14 4:26 UTC (permalink / raw)
To: jsnow
Cc: fam, qemu-block, qemu-devel, kwolf, vsementsov, armbru, mreitz, pbonzini
Patchew URL: https://patchew.org/QEMU/20190212200750.27521-1-jsnow@redhat.com/
Hi,
This series failed the docker-mingw@fedora build test. Please find the testing commands and
their output below. If you have Docker installed, you can probably reproduce it
locally.
=== TEST SCRIPT BEGIN ===
#!/bin/bash
time make docker-test-mingw@fedora SHOW_ENV=1 J=14
=== TEST SCRIPT END ===
CC ui/input-keymap.o
CC ui/kbd-state.o
/tmp/qemu-test/src/blockdev.c: In function 'qmp_block_dirty_bitmap_add':
/tmp/qemu-test/src/blockdev.c:2868:17: error: expected ';' before '}' token
goto out
^
;
The full log is available at
http://patchew.org/logs/20190212200750.27521-1-jsnow@redhat.com/testing.docker-mingw@fedora/?type=message.
---
Email generated automatically by Patchew [http://patchew.org/].
Please send your feedback to patchew-devel@redhat.com
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-02-14 4:28 UTC | newest]
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-- links below jump to the message on this page --
2019-02-12 20:07 [Qemu-devel] [PATCH v2] blockdev: acquire aio_context for bitmap add/remove John Snow
2019-02-12 20:16 ` Eric Blake
2019-02-12 21:37 ` John Snow
2019-02-12 22:04 ` Eric Blake
2019-02-13 16:41 ` no-reply
2019-02-14 4:26 ` no-reply
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