From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C72BFC4167B for ; Tue, 7 Nov 2023 18:48:46 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r0R69-0004Ln-L7; Tue, 07 Nov 2023 13:46:49 -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 1r0R5h-0003vS-SL for qemu-devel@nongnu.org; Tue, 07 Nov 2023 13:46:23 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r0R5f-0001UH-Ab for qemu-devel@nongnu.org; Tue, 07 Nov 2023 13:46:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1699382777; 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=Drxgkp0ROJENIrnPXu5nTdA0hV4Rbo4Y1Phpl0DAVFc=; b=dbYk8n264owuIk/efYtGjuy+Lb4pV7VGICWkSoRxMK3nfPxYQeKP50XyGVqa27HiSst9w2 uQg290Q5vci/7bsojgIT9+F0RX8a0K0nOLNi/Hsp0Af7biZmZHYjqz3Km0bToIECkDMaQl b5CdLONLKBmbIScUglcagdvLKo1hudU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-639-H-3So__5NB2fZkqyJMTt7g-1; Tue, 07 Nov 2023 13:46:15 -0500 X-MC-Unique: H-3So__5NB2fZkqyJMTt7g-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 77F41101AA42 for ; Tue, 7 Nov 2023 18:46:15 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.197]) by smtp.corp.redhat.com (Postfix) with ESMTP id 023D0C1290F; Tue, 7 Nov 2023 18:46:14 +0000 (UTC) From: Kevin Wolf To: qemu-devel@nongnu.org Cc: kwolf@redhat.com Subject: [PULL 10/25] block: Mark bdrv_chain_contains() and callers GRAPH_RDLOCK Date: Tue, 7 Nov 2023 19:45:50 +0100 Message-ID: <20231107184605.236540-11-kwolf@redhat.com> In-Reply-To: <20231107184605.236540-1-kwolf@redhat.com> References: <20231107184605.236540-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_chain_contains() need to hold a reader lock for the graph because it calls bdrv_filter_or_cow_bs(), which accesses bs->file/backing. Signed-off-by: Kevin Wolf Message-ID: <20231027155333.420094-11-kwolf@redhat.com> Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- include/block/block-global-state.h | 4 ++- block.c | 1 - block/block-copy.c | 2 ++ blockdev.c | 48 +++++++++++++++++------------- 4 files changed, 32 insertions(+), 23 deletions(-) diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h index 545708c35a..9a33bd7ef9 100644 --- a/include/block/block-global-state.h +++ b/include/block/block-global-state.h @@ -199,7 +199,9 @@ XDbgBlockGraph * GRAPH_RDLOCK bdrv_get_xdbg_block_graph(Error **errp); BlockDriverState *bdrv_lookup_bs(const char *device, const char *node_name, Error **errp); -bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base); +bool GRAPH_RDLOCK +bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base); + BlockDriverState *bdrv_next_node(BlockDriverState *bs); BlockDriverState *bdrv_next_all_states(BlockDriverState *bs); diff --git a/block.c b/block.c index dc1980ee42..bb322df7d8 100644 --- a/block.c +++ b/block.c @@ -6524,7 +6524,6 @@ bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) { GLOBAL_STATE_CODE(); - GRAPH_RDLOCK_GUARD_MAINLOOP(); while (top && top != base) { top = bdrv_filter_or_cow_bs(top); diff --git a/block/block-copy.c b/block/block-copy.c index 6b2be3d204..9ee3dd7ef5 100644 --- a/block/block-copy.c +++ b/block/block-copy.c @@ -399,7 +399,9 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target, * For more information see commit f8d59dfb40bb and test * tests/qemu-iotests/222 */ + bdrv_graph_rdlock_main_loop(); is_fleecing = bdrv_chain_contains(target->bs, source->bs); + bdrv_graph_rdunlock_main_loop(); s = g_new(BlockCopyState, 1); *s = (BlockCopyState) { diff --git a/blockdev.c b/blockdev.c index 5f15ea3b1d..f04faf6373 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2450,11 +2450,12 @@ void qmp_block_stream(const char *job_id, const char *device, aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); + bdrv_graph_rdlock_main_loop(); if (base) { base_bs = bdrv_find_backing_image(bs, base); if (base_bs == NULL) { error_setg(errp, "Can't find '%s' in the backing chain", base); - goto out; + goto out_rdlock; } assert(bdrv_get_aio_context(base_bs) == aio_context); } @@ -2462,38 +2463,36 @@ void qmp_block_stream(const char *job_id, const char *device, if (base_node) { base_bs = bdrv_lookup_bs(NULL, base_node, errp); if (!base_bs) { - goto out; + goto out_rdlock; } if (bs == base_bs || !bdrv_chain_contains(bs, base_bs)) { error_setg(errp, "Node '%s' is not a backing image of '%s'", base_node, device); - goto out; + goto out_rdlock; } assert(bdrv_get_aio_context(base_bs) == aio_context); - bdrv_graph_rdlock_main_loop(); bdrv_refresh_filename(base_bs); - bdrv_graph_rdunlock_main_loop(); } if (bottom) { bottom_bs = bdrv_lookup_bs(NULL, bottom, errp); if (!bottom_bs) { - goto out; + goto out_rdlock; } if (!bottom_bs->drv) { error_setg(errp, "Node '%s' is not open", bottom); - goto out; + goto out_rdlock; } if (bottom_bs->drv->is_filter) { error_setg(errp, "Node '%s' is a filter, use a non-filter node " "as 'bottom'", bottom); - goto out; + goto out_rdlock; } if (!bdrv_chain_contains(bs, bottom_bs)) { error_setg(errp, "Node '%s' is not in a chain starting from '%s'", bottom, device); - goto out; + goto out_rdlock; } assert(bdrv_get_aio_context(bottom_bs) == aio_context); } @@ -2501,14 +2500,12 @@ void qmp_block_stream(const char *job_id, const char *device, /* * Check for op blockers in the whole chain between bs and base (or bottom) */ - bdrv_graph_rdlock_main_loop(); iter_end = bottom ? bdrv_filter_or_cow_bs(bottom_bs) : base_bs; for (iter = bs; iter && iter != iter_end; iter = bdrv_filter_or_cow_bs(iter)) { if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_STREAM, errp)) { - bdrv_graph_rdunlock_main_loop(); - goto out; + goto out_rdlock; } } bdrv_graph_rdunlock_main_loop(); @@ -2540,6 +2537,11 @@ void qmp_block_stream(const char *job_id, const char *device, out: aio_context_release(aio_context); + return; + +out_rdlock: + bdrv_graph_rdunlock_main_loop(); + aio_context_release(aio_context); } void qmp_block_commit(const char *job_id, const char *device, @@ -3439,39 +3441,38 @@ void qmp_change_backing_file(const char *device, aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); + bdrv_graph_rdlock_main_loop(); + image_bs = bdrv_lookup_bs(NULL, image_node_name, &local_err); if (local_err) { error_propagate(errp, local_err); - goto out; + goto out_rdlock; } if (!image_bs) { error_setg(errp, "image file not found"); - goto out; + goto out_rdlock; } - bdrv_graph_rdlock_main_loop(); if (bdrv_find_base(image_bs) == image_bs) { error_setg(errp, "not allowing backing file change on an image " "without a backing file"); - bdrv_graph_rdunlock_main_loop(); - goto out; + goto out_rdlock; } /* even though we are not necessarily operating on bs, we need it to * determine if block ops are currently prohibited on the chain */ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) { - bdrv_graph_rdunlock_main_loop(); - goto out; + goto out_rdlock; } - bdrv_graph_rdunlock_main_loop(); /* final sanity check */ if (!bdrv_chain_contains(bs, image_bs)) { error_setg(errp, "'%s' and image file are not in the same chain", device); - goto out; + goto out_rdlock; } + bdrv_graph_rdunlock_main_loop(); /* if not r/w, reopen to make r/w */ ro = bdrv_is_read_only(image_bs); @@ -3499,6 +3500,11 @@ void qmp_change_backing_file(const char *device, out: aio_context_release(aio_context); + return; + +out_rdlock: + bdrv_graph_rdunlock_main_loop(); + aio_context_release(aio_context); } void qmp_blockdev_add(BlockdevOptions *options, Error **errp) -- 2.41.0