From patchwork Tue Jun 30 03:34:36 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 489478 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id D6B6B140913 for ; Tue, 30 Jun 2015 13:33:42 +1000 (AEST) Received: from localhost ([::1]:44802 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9mIm-00065V-Vh for incoming@patchwork.ozlabs.org; Mon, 29 Jun 2015 23:33:40 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52813) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9mGc-0001g0-81 for qemu-devel@nongnu.org; Mon, 29 Jun 2015 23:31:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z9mGa-0008Pv-3v for qemu-devel@nongnu.org; Mon, 29 Jun 2015 23:31:26 -0400 Received: from [59.151.112.132] (port=38433 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9mGZ-0008EB-Id; Mon, 29 Jun 2015 23:31:24 -0400 X-IronPort-AV: E=Sophos;i="5.13,665,1427731200"; d="scan'208";a="97890035" Received: from unknown (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 30 Jun 2015 11:35:06 +0800 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t5U3TRTf028000; Tue, 30 Jun 2015 11:29:27 +0800 Received: from G08FNSTD140052.g08.fujitsu.local (10.167.226.52) by G08CNEXCHPEKD02.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Tue, 30 Jun 2015 11:31:07 +0800 From: Wen Congyang To: qemu devel , Fam Zheng , Max Reitz , Paolo Bonzini Date: Tue, 30 Jun 2015 11:34:36 +0800 Message-ID: <1435635285-5804-9-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1435635285-5804-1-git-send-email-wency@cn.fujitsu.com> References: <1435635285-5804-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.52] X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 59.151.112.132 Cc: Kevin Wolf , qemu block , Lai Jiangshan , Jiang Yunhong , Dong Eddie , "Dr. David Alan Gilbert" , Stefan Hajnoczi , Yang Hongyang Subject: [Qemu-devel] [PATCH COLO-BLOCK v7 08/17] block: make bdrv_put_ref_bh_schedule() as a public API 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 Signed-off-by: Wen Congyang --- block.c | 25 +++++++++++++++++++++++++ blockdev.c | 37 ++++++------------------------------- include/block/block.h | 1 + 3 files changed, 32 insertions(+), 31 deletions(-) diff --git a/block.c b/block.c index dbbba5d..7619981 100644 --- a/block.c +++ b/block.c @@ -3574,6 +3574,31 @@ void bdrv_unref(BlockDriverState *bs) } } +typedef struct { + QEMUBH *bh; + BlockDriverState *bs; +} BDRVPutRefBH; + +static void bdrv_put_ref_bh(void *opaque) +{ + BDRVPutRefBH *s = opaque; + + bdrv_unref(s->bs); + qemu_bh_delete(s->bh); + g_free(s); +} + +/* Release a BDS reference in a BH */ +void bdrv_put_ref_bh_schedule(BlockDriverState *bs) +{ + BDRVPutRefBH *s; + + s = g_new(BDRVPutRefBH, 1); + s->bh = qemu_bh_new(bdrv_put_ref_bh, s); + s->bs = bs; + qemu_bh_schedule(s->bh); +} + struct BdrvOpBlocker { Error *reason; QLIST_ENTRY(BdrvOpBlocker) list; diff --git a/blockdev.c b/blockdev.c index 935c081..dd1022c 100644 --- a/blockdev.c +++ b/blockdev.c @@ -276,37 +276,6 @@ static void bdrv_format_print(void *opaque, const char *name) error_printf(" %s", name); } -typedef struct { - QEMUBH *bh; - BlockDriverState *bs; -} BDRVPutRefBH; - -static void bdrv_put_ref_bh(void *opaque) -{ - BDRVPutRefBH *s = opaque; - - bdrv_unref(s->bs); - qemu_bh_delete(s->bh); - g_free(s); -} - -/* - * Release a BDS reference in a BH - * - * It is not safe to use bdrv_unref() from a callback function when the callers - * still need the BlockDriverState. In such cases we schedule a BH to release - * the reference. - */ -static void bdrv_put_ref_bh_schedule(BlockDriverState *bs) -{ - BDRVPutRefBH *s; - - s = g_new(BDRVPutRefBH, 1); - s->bh = qemu_bh_new(bdrv_put_ref_bh, s); - s->bs = bs; - qemu_bh_schedule(s->bh); -} - static int parse_block_error_action(const char *buf, bool is_read, Error **errp) { if (!strcmp(buf, "ignore")) { @@ -2329,6 +2298,12 @@ static void block_job_cb(void *opaque, int ret) block_job_event_completed(bs->job, msg); } + + /* + * It is not safe to use bdrv_unref() from a callback function when the + * callers still need the BlockDriverState. In such cases we schedule + * a BH to release the reference. + */ bdrv_put_ref_bh_schedule(bs); } diff --git a/include/block/block.h b/include/block/block.h index c43160d..0dec16c 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -503,6 +503,7 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs); void bdrv_ref(BlockDriverState *bs); void bdrv_unref(BlockDriverState *bs); +void bdrv_put_ref_bh_schedule(BlockDriverState *bs); bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);