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spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:52472 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kzJhI-00055i-8w for qemu-devel@archiver.kernel.org; Tue, 12 Jan 2021 08:27:04 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:35580) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzJeE-0003Ru-17 for qemu-devel@nongnu.org; Tue, 12 Jan 2021 08:23:46 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:42389) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kzJeA-0006qe-E2 for qemu-devel@nongnu.org; Tue, 12 Jan 2021 08:23:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610457821; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gswitTSe3iYhD8ouzsmowrwKZdgBW2DPzl6oPa1zhr8=; b=ZwFcz65QUPfAoFiWNpCCtzU+tcTxzCTmElAcyXbY63NK4aJbGmAz/El0K033FKCD+LuSSf hgWGmVO25Z4KmhWzfve4IkJA4YFFmWMXXUn5Qk60iQYlc8LBBzD5clARNDgC/haJQ0m4jJ EoUPRNw+kk9BOxGwNClpaW5Lqm4Q7rI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-436-MTPKjTxPM9WfYP00HE9dNg-1; Tue, 12 Jan 2021 08:23:39 -0500 X-MC-Unique: MTPKjTxPM9WfYP00HE9dNg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 943F19CDB3; Tue, 12 Jan 2021 13:23:38 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-115-161.ams2.redhat.com [10.36.115.161]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 64F8110016F5; Tue, 12 Jan 2021 13:23:36 +0000 (UTC) Subject: Re: [PATCH v3 19/25] backup: move to block-copy To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20201026171815.13233-1-vsementsov@virtuozzo.com> <20201026171815.13233-20-vsementsov@virtuozzo.com> From: Max Reitz Message-ID: <9708f8d8-3afc-f30d-9245-20071763c5a3@redhat.com> Date: Tue, 12 Jan 2021 14:23:34 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <20201026171815.13233-20-vsementsov@virtuozzo.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.251, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, wencongyang2@huawei.com, xiechanglong.d@gmail.com, qemu-devel@nongnu.org, armbru@redhat.com, den@openvz.org, jsnow@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 26.10.20 18:18, Vladimir Sementsov-Ogievskiy wrote: > This brings async request handling and block-status driven chunk sizes > to backup out of the box, which improves backup performance. > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > block/backup.c | 187 ++++++++++++++++++++++++++++++++----------------- > 1 file changed, 121 insertions(+), 66 deletions(-) Reviewed-by: Max Reitz Irrelevant notes below. > diff --git a/block/backup.c b/block/backup.c > index 449b763ce4..0d1cd64eab 100644 > --- a/block/backup.c > +++ b/block/backup.c (Just something I noted when looking for remaining instances of “ratelimit”: backup.c includes ratelimit.h, which I don’t think it needs to do any longer) [...] > static int coroutine_fn backup_loop(BackupBlockJob *job) > { [...] > + if (!block_copy_call_finished(s) && > + job_is_cancelled(&job->common.job)) > + { Just for the sake of clarity: If !block_copy_call_finished(), then job_is_cancelled() must be true, right? (I.e., could be an assertion instead of the second part of the condition. I don’t mind how it is, but then again, it did made me ask.) > + /* > + * Note that we can't use job_yield() here, as it doesn't work for > + * cancelled job. > + */ > + block_copy_call_cancel(s); > + job->wait = true; > + qemu_coroutine_yield(); > + assert(block_copy_call_finished(s)); > + ret = 0; > + goto out; > + } > + > + if (job_is_cancelled(&job->common.job) || > + block_copy_call_succeeded(s)) > + { > + ret = 0; > + goto out; > + } > + > + if (block_copy_call_cancelled(s)) { > + /* > + * Job is not cancelled but only block-copy call. This is possible > + * after job pause. Now the pause is finished, start new block-copy > + * iteration. > + */ > + block_copy_call_free(s); > + continue; If one were to avoid all continues, we could alternatively put the whole error handling into a block_copy_call_failed() condition, and have the block_copy_call_free() common for both the cancel and the fail case. *shrug* > + } > + > + /* The only remaining case is failed block-copy call. */ > + assert(block_copy_call_failed(s)); > + > + ret = block_copy_call_status(s, &error_is_read); > + act = backup_error_action(job, error_is_read, -ret); > + switch (act) { > + case BLOCK_ERROR_ACTION_REPORT: > + goto out; > + case BLOCK_ERROR_ACTION_STOP: > + /* > + * Go to pause prior to starting new block-copy call on the next > + * iteration. > + */ > + job_pause_point(&job->common.job); > + break; > + case BLOCK_ERROR_ACTION_IGNORE: > + /* Proceed to new block-copy call to retry. */ > + break; > + default: > + abort(); > + } > + > + block_copy_call_free(s); > } > > - out: > - bdrv_dirty_iter_free(bdbi); > +out: > + block_copy_call_free(s); Reads a bit weird after the block_copy_call_free(s) at the end of the while (true) loop, but is entirely correct, of course. (And I can’t offer any better alternative.) Max > + job->bg_bcs_call = NULL; > return ret; > }