From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38323) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wka5Q-0006jT-G7 for qemu-devel@nongnu.org; Wed, 14 May 2014 10:23:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wka5H-0003ip-Jx for qemu-devel@nongnu.org; Wed, 14 May 2014 10:23:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8107) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wka5H-0003ih-BJ for qemu-devel@nongnu.org; Wed, 14 May 2014 10:23:03 -0400 From: Stefan Hajnoczi Date: Wed, 14 May 2014 16:22:47 +0200 Message-Id: <1400077367-23409-4-git-send-email-stefanha@redhat.com> In-Reply-To: <1400077367-23409-1-git-send-email-stefanha@redhat.com> References: <1400077367-23409-1-git-send-email-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH 3/3] blockdev: acquire AioContext in block_set_io_throttle List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , =?UTF-8?q?Beno=C3=AEt=20Canet?= , =?UTF-8?q?Beno=C3=AEt=20Canet?= , Stefan Hajnoczi The block_set_io_throttle QMP and HMP commands modify I/O throttling limits for block devices. Acquire the BlockDriverState's AioContext to protect against race conditions with an IOThread that is running I/O for this device. Cc: Beno=C3=AEt Canet Signed-off-by: Stefan Hajnoczi --- blockdev.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/blockdev.c b/blockdev.c index 7810e9f..e0f1978 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1663,6 +1663,7 @@ void qmp_block_set_io_throttle(const char *device, = int64_t bps, int64_t bps_rd, { ThrottleConfig cfg; BlockDriverState *bs; + AioContext *aio_context; =20 bs =3D bdrv_find(device); if (!bs) { @@ -1706,6 +1707,9 @@ void qmp_block_set_io_throttle(const char *device, = int64_t bps, int64_t bps_rd, return; } =20 + aio_context =3D bdrv_get_aio_context(bs); + aio_context_acquire(aio_context); + if (!bs->io_limits_enabled && throttle_enabled(&cfg)) { bdrv_io_limits_enable(bs); } else if (bs->io_limits_enabled && !throttle_enabled(&cfg)) { @@ -1715,6 +1719,8 @@ void qmp_block_set_io_throttle(const char *device, = int64_t bps, int64_t bps_rd, if (bs->io_limits_enabled) { bdrv_set_io_limits(bs, &cfg); } + + aio_context_release(aio_context); } =20 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data) --=20 1.9.0