From: Paolo Bonzini <pbonzini@redhat.com>
To: Fam Zheng <famz@redhat.com>, qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
qemu-block@nongnu.org
Subject: Re: [Qemu-devel] [PATCH v2 05/12] block: Introduce "drained begin/end" API
Date: Mon, 12 Oct 2015 16:27:06 +0200 [thread overview]
Message-ID: <561BC33A.4030108@redhat.com> (raw)
In-Reply-To: <1444650651-26227-6-git-send-email-famz@redhat.com>
On 12/10/2015 13:50, Fam Zheng wrote:
> +void bdrv_drained_begin(BlockDriverState *bs)
> +{
> + if (bs->quiesce_counter++) {
> + return;
> + }
> + aio_disable_external(bdrv_get_aio_context(bs));
> + bdrv_drain(bs);
> +}
I think bdrv_drain should be called unconditionally, i.e. before the
"if". This should also solve Kevin's doubt about new allocating write
request reenabling the timer: any write request from the drained section
happens normally, until you get a nested drain request and then the
callback completes the requests.
Paolo
next prev parent reply other threads:[~2015-10-12 14:27 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-12 11:50 [Qemu-devel] [PATCH v2 00/12] block: bdrv_drained_begin/end for transactions on dataplane devices Fam Zheng
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 01/12] aio: Add "is_external" flag for event handlers Fam Zheng
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 02/12] nbd: Mark fd handlers client type as "external" Fam Zheng
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 03/12] dataplane: Mark host notifiers' " Fam Zheng
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 04/12] aio: introduce aio_{disable, enable}_external Fam Zheng
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 05/12] block: Introduce "drained begin/end" API Fam Zheng
2015-10-12 13:59 ` Kevin Wolf
2015-10-12 14:27 ` Paolo Bonzini [this message]
2015-10-13 9:31 ` Kevin Wolf
2015-10-13 10:39 ` Paolo Bonzini
2015-10-13 11:12 ` Kevin Wolf
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 06/12] block: Add "drained begin/end" for transactional external snapshot Fam Zheng
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 07/12] block: Add "drained begin/end" for transactional backup Fam Zheng
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 08/12] block: Add "drained begin/end" for transactional blockdev-backup Fam Zheng
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 09/12] block: Add "drained begin/end" for internal snapshot Fam Zheng
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 10/12] block: Introduce BlockDriver.bdrv_drain callback Fam Zheng
2015-10-12 14:17 ` Kevin Wolf
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 11/12] qed: Implement .bdrv_drain Fam Zheng
2015-10-12 14:23 ` Kevin Wolf
2015-10-12 11:50 ` [Qemu-devel] [PATCH v2 12/12] tests: Add test case for aio_disable_external Fam Zheng
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