From patchwork Wed Nov 16 13:48:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Emanuele Giuseppe Esposito X-Patchwork-Id: 1704613 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=WGc1+b+E; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4NC4DZ2Wldz23n9 for ; Thu, 17 Nov 2022 00:50:06 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ovIn9-0000vb-1l; Wed, 16 Nov 2022 08:49:27 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ovImw-0000kl-Dp for qemu-devel@nongnu.org; Wed, 16 Nov 2022 08:49:14 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ovImm-00081v-7z for qemu-devel@nongnu.org; Wed, 16 Nov 2022 08:49:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668606542; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=05S0MrrbIh+OBWpI7z5ExyTAe4OPZXPHZsDvNzgylxE=; b=WGc1+b+EnKn6cWWMSU6gEWegsmGTD874ee2cnRPFm1O4Ls9XXJGwj/0iHtpmiSoBhPFpIe agnlDiLVkdS2JsHMwxgOgfrC6sp6JhUjeK23T80O3NM7/hRJ83c9NKHugfuZ0kpWn/C02/ HwNG8zg78ou/X+tN7b2W/Utubhb1nQo= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-148-Hc8eFjYVM--ZTcw0lfKLOw-1; Wed, 16 Nov 2022 08:48:59 -0500 X-MC-Unique: Hc8eFjYVM--ZTcw0lfKLOw-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id ADDCB3C01DED; Wed, 16 Nov 2022 13:48:58 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id CA2D74A9266; Wed, 16 Nov 2022 13:48:57 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Cc: Kevin Wolf , Hanna Reitz , John Snow , Paolo Bonzini , Vladimir Sementsov-Ogievskiy , Stefan Hajnoczi , Fam Zheng , Eric Blake , Cleber Rosa , qemu-devel@nongnu.org, Emanuele Giuseppe Esposito Subject: [PATCH 17/20] block-gen: assert that bdrv_co_pdiscard is always called with graph rdlock taken Date: Wed, 16 Nov 2022 08:48:47 -0500 Message-Id: <20221116134850.3051419-18-eesposit@redhat.com> In-Reply-To: <20221116134850.3051419-1-eesposit@redhat.com> References: <20221116134850.3051419-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 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: -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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This function, in addition to be called by a generated_co_wrapper, is also called by the blk_* API. The strategy is to always take the lock at the function called when the coroutine is created, to avoid recursive locking. Protecting bdrv_co_pdiscard{_snapshot}() implies that the following BlockDriver callbacks always called with graph rdlock taken: - bdrv_co_pdiscard - bdrv_aio_pdiscard - bdrv_co_pdiscard_snapshot Signed-off-by: Emanuele Giuseppe Esposito --- block/block-backend.c | 1 + block/io.c | 2 ++ include/block/block_int-common.h | 3 +++ 3 files changed, 6 insertions(+) diff --git a/block/block-backend.c b/block/block-backend.c index d660772375..211a813523 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1716,6 +1716,7 @@ blk_co_do_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes) IO_CODE(); blk_wait_while_drained(blk); + GRAPH_RDLOCK_GUARD(); ret = blk_check_byte_request(blk, offset, bytes); if (ret < 0) { diff --git a/block/io.c b/block/io.c index c9b451fecd..bc9f47538c 100644 --- a/block/io.c +++ b/block/io.c @@ -2885,6 +2885,7 @@ int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int head, tail, align; BlockDriverState *bs = child->bs; IO_CODE(); + assert_bdrv_graph_readable(); if (!bs || !bs->drv || !bdrv_is_inserted(bs)) { return -ENOMEDIUM; @@ -3488,6 +3489,7 @@ bdrv_co_pdiscard_snapshot(BlockDriverState *bs, int64_t offset, int64_t bytes) BlockDriver *drv = bs->drv; int ret; IO_CODE(); + assert_bdrv_graph_readable(); if (!drv) { return -ENOMEDIUM; diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index 568c2d3092..7c34a8e40f 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -486,6 +486,7 @@ struct BlockDriver { BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque); BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs, BlockCompletionFunc *cb, void *opaque); + /* Called with graph rdlock taken. */ BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs, int64_t offset, int bytes, BlockCompletionFunc *cb, void *opaque); @@ -559,6 +560,7 @@ struct BlockDriver { */ int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs, int64_t offset, int64_t bytes, BdrvRequestFlags flags); + /* Called with graph rdlock taken. */ int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs, int64_t offset, int64_t bytes); @@ -647,6 +649,7 @@ struct BlockDriver { int coroutine_fn (*bdrv_co_snapshot_block_status)(BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file); + /* Called with graph rdlock taken. */ int coroutine_fn (*bdrv_co_pdiscard_snapshot)(BlockDriverState *bs, int64_t offset, int64_t bytes);