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bh=F7NwFsCFY1ZCxrd9bRPmNUOXiKGCgh0XcDto2jSEUCQ=; b=i7fDYh0d95vWOWQfukIOZNs7wAqgRWFDVBMLe8WVhq3gRlGRcpk7k9K17VmDELrcK1xm/7 oQPqErrlQlvwmkd9malBUk3huj7h4ZlMQAtXXHq9l61+3brl1W9RpXkUja308yzh8G72yd 4f7Y/LSC38fB5YTl/jHBWrpuo7E999I= X-MC-Unique: cxtm6m-yN_uXk7RBST2ShA-1 From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH v2 2/8] block: protect write threshold QMP commands from concurrent requests Date: Mon, 19 Apr 2021 10:55:35 +0200 Message-Id: <20210419085541.22310-3-eesposit@redhat.com> In-Reply-To: <20210419085541.22310-1-eesposit@redhat.com> References: <20210419085541.22310-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eesposit@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable 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=170.10.133.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, 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: Kevin Wolf , Fam Zheng , qemu-devel@nongnu.org, Emanuele Giuseppe Esposito , Markus Armbruster , Max Reitz , Stefan Hajnoczi , Paolo Bonzini , John Snow Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" For simplicity, use bdrv_drained_begin/end to avoid concurrent writes to the write threshold, or reading it while it is being set. qmp_block_set_write_threshold is protected by the BQL. Reviewed-by: Stefan Hajnoczi Co-developed-by: Paolo Bonzini Signed-off-by: Emanuele Giuseppe Esposito --- block/write-threshold.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/block/write-threshold.c b/block/write-threshold.c index 63040fa4f2..77c74bdaa7 100644 --- a/block/write-threshold.c +++ b/block/write-threshold.c @@ -111,7 +111,6 @@ void qmp_block_set_write_threshold(const char *node_nam= e, Error **errp) { BlockDriverState *bs; - AioContext *aio_context; =20 bs =3D bdrv_find_node(node_name); if (!bs) { @@ -119,10 +118,8 @@ void qmp_block_set_write_threshold(const char *node_na= me, return; } =20 - aio_context =3D bdrv_get_aio_context(bs); - aio_context_acquire(aio_context); - + /* Avoid a concurrent write_threshold_disable. */ + bdrv_drained_begin(bs); bdrv_write_threshold_set(bs, threshold_bytes); - - aio_context_release(aio_context); + bdrv_drained_end(bs); } --=20 2.30.2