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bh=9jar66EgWAWpe6Qk8yO0Iso5fl52X8ZjyyQ+aBAGVe0=; b=g8j5hIlRIahdpp5Ji0sJ70ewIhlkq3+qlo31/Wb3MTXTKJ11aX/aZst81UpvMH/a+ORbGy mPJmuDw18THgfd36VeZuxRSf3+hlB3FuRd3aK0AT0lQxYjzvVw9qQDiFjcNvlbPqYCyqTg +6J0Bzkzuoo6GfF1QWZWMtFW/G1IV3s= X-MC-Unique: b5FlmGpuOb-BSFCwX5_cWw-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Fam Zheng , qemu-block@nongnu.org, Emanuele Giuseppe Esposito , Markus Armbruster , Kevin Wolf , Stefan Hajnoczi , "Dr. David Alan Gilbert" , Hanna Reitz Subject: [PATCH 3/6] block: convert bdrv_graph_wrlock() to AIO_WAIT_WHILE_UNLOCKED() Date: Wed, 1 Mar 2023 15:57:58 -0500 Message-Id: <20230301205801.2453491-4-stefanha@redhat.com> In-Reply-To: <20230301205801.2453491-1-stefanha@redhat.com> References: <20230301205801.2453491-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1677704396377100003 Content-Type: text/plain; charset="utf-8" The following conversion is safe and does not change behavior: GLOBAL_STATE_CODE(); ... - AIO_WAIT_WHILE(qemu_get_aio_context(), ...); + AIO_WAIT_WHILE_UNLOCKED(NULL, ...); Since we're in GLOBAL_STATE_CODE(), qemu_get_aio_context() is our home thread's AioContext. Thus AIO_WAIT_WHILE() does not unlock the AioContext: if (ctx_ && in_aio_context_home_thread(ctx_)) { \ while ((cond)) { \ aio_poll(ctx_, true); \ waited_ =3D true; \ } \ And that means AIO_WAIT_WHILE_UNLOCKED(NULL, ...) can be substituted. Signed-off-by: Stefan Hajnoczi Reviewed-by: Philippe Mathieu-Daud=C3=A9 Tested-by: Philippe Mathieu-Daud=C3=A9 --- block/graph-lock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/graph-lock.c b/block/graph-lock.c index 454c31e691..639526608f 100644 --- a/block/graph-lock.c +++ b/block/graph-lock.c @@ -127,7 +127,7 @@ void bdrv_graph_wrlock(void) * reader lock. */ qatomic_set(&has_writer, 0); - AIO_WAIT_WHILE(qemu_get_aio_context(), reader_count() >=3D 1); + AIO_WAIT_WHILE_UNLOCKED(NULL, reader_count() >=3D 1); qatomic_set(&has_writer, 1); =20 /* --=20 2.39.2