From patchwork Tue Sep 18 11:40:40 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 184685 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id EA4262C009D for ; Tue, 18 Sep 2012 21:43:05 +1000 (EST) Received: from localhost ([::1]:37993 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDwCl-0002tJ-Bv for incoming@patchwork.ozlabs.org; Tue, 18 Sep 2012 07:43:03 -0400 Received: from eggs.gnu.org ([208.118.235.92]:35494) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDwAr-0007Pq-GB for qemu-devel@nongnu.org; Tue, 18 Sep 2012 07:41:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TDwAl-0005KZ-HE for qemu-devel@nongnu.org; Tue, 18 Sep 2012 07:41:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53470) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDwAl-0005KL-7n for qemu-devel@nongnu.org; Tue, 18 Sep 2012 07:40:59 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q8IBewF5018431 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 18 Sep 2012 07:40:58 -0400 Received: from dhcp-5-188.str.redhat.com (dhcp-5-175.str.redhat.com [10.32.5.175]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q8IBegGY028821; Tue, 18 Sep 2012 07:40:57 -0400 From: Kevin Wolf To: qemu-devel@nongnu.org Date: Tue, 18 Sep 2012 13:40:40 +0200 Message-Id: <1347968442-8860-15-git-send-email-kwolf@redhat.com> In-Reply-To: <1347968442-8860-1-git-send-email-kwolf@redhat.com> References: <1347968442-8860-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com Subject: [Qemu-devel] [RFC PATCH 14/16] qcow2: Execute run_dependent_requests() without lock X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org There's no reason for run_dependent_requests() to hold s->lock, and a later patch will require that in fact the lock is not held. Also, before this patch, run_dependent_requests() not only does what its name suggests, but also removes the l2meta from the list of in-flight requests. Change this, while we're touching it. Signed-off-by: Kevin Wolf --- block/qcow2.c | 26 +++++++++++++++----------- 1 files changed, 15 insertions(+), 11 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index e001436..88a2020 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -739,16 +739,9 @@ fail: static void run_dependent_requests(BDRVQcowState *s, QCowL2Meta *m) { - /* Take the request off the list of running requests */ - if (m->nb_clusters != 0) { - QLIST_REMOVE(m, next_in_flight); - } - /* Restart all dependent requests */ if (!qemu_co_queue_empty(&m->dependent_requests)) { - qemu_co_mutex_unlock(&s->lock); qemu_co_queue_restart_all(&m->dependent_requests); - qemu_co_mutex_lock(&s->lock); } } @@ -800,10 +793,18 @@ again: goto again; } + qemu_co_mutex_unlock(&s->lock); + + /* Take the request off the list of running requests */ + if (m->nb_clusters != 0) { + QLIST_REMOVE(m, next_in_flight); + } + + /* Meanwhile some new dependencies could have accumulated */ run_dependent_requests(s, m); + g_free(m); - qemu_co_mutex_unlock(&s->lock); qemu_co_rwlock_unlock(&s->l2meta_flush); } @@ -961,13 +962,16 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, ret = 0; fail: + qemu_co_mutex_unlock(&s->lock); + if (l2meta != NULL) { + if (l2meta->nb_clusters != 0) { + QLIST_REMOVE(l2meta, next_in_flight); + } run_dependent_requests(s, l2meta); g_free(l2meta); } - qemu_co_mutex_unlock(&s->lock); - qemu_iovec_destroy(&hd_qiov); qemu_vfree(cluster_data); trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); @@ -1259,7 +1263,7 @@ static int preallocate(BlockDriverState *bs) /* There are no dependent requests, but we need to remove our request * from the list of in-flight requests */ if (meta != NULL) { - run_dependent_requests(bs->opaque, meta); + QLIST_REMOVE(meta, next_in_flight); } /* TODO Preallocate data if requested */