From patchwork Thu Oct 12 16:22:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 1847641 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org 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=aOUFy7tg; dkim-atps=neutral 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=patchwork.ozlabs.org) 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 4S5wBX0bvTz26jV for ; Fri, 13 Oct 2023 03:31:32 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qqySr-0003bn-VU; Thu, 12 Oct 2023 12:23:09 -0400 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 1qqySf-0003W7-6Z for qemu-devel@nongnu.org; Thu, 12 Oct 2023 12:22:58 -0400 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 1qqySZ-0000aX-Ix for qemu-devel@nongnu.org; Thu, 12 Oct 2023 12:22:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697127770; 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=tlN6iMJXkvZ5CxaOBhxGfG4aTt2NXDSLahJ4Qvh91PM=; b=aOUFy7tgU2/uMLG7mG1N863NFy32ipQQFMPDnZloJQLxB7uu5jpEPPmxZFyPX98NqxIfHR LhnT7ns9KK5/s72MB2yd5vkMNaLCvBRL4XErxOJ/W0QVVvyB0DVM0ZkjEbj23ng8t/CBCE CLpuBBxH+ILQfM/Fs1QxSM/rzcX/ibQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-581-wU8iDFY7NdKt2Ia21aYq-A-1; Thu, 12 Oct 2023 12:22:45 -0400 X-MC-Unique: wU8iDFY7NdKt2Ia21aYq-A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8D6668039C1; Thu, 12 Oct 2023 16:22:44 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.192.233]) by smtp.corp.redhat.com (Postfix) with ESMTP id F1BA920296DB; Thu, 12 Oct 2023 16:22:43 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [PULL 11/26] block: Mark bdrv_snapshot_fallback() and callers GRAPH_RDLOCK Date: Thu, 12 Oct 2023 18:22:09 +0200 Message-ID: <20231012162224.240535-12-kwolf@redhat.com> In-Reply-To: <20231012162224.240535-1-kwolf@redhat.com> References: <20231012162224.240535-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 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 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_snapshot_fallback() need to hold a reader lock for the graph because it accesses the children list of a node. Signed-off-by: Kevin Wolf Message-ID: <20230929145157.45443-8-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- include/block/block_int-common.h | 18 ++++++++-------- include/block/snapshot.h | 24 +++++++++++++--------- block/snapshot.c | 35 ++++++++++++++++++++++++++------ blockdev.c | 9 ++++++++ qemu-img.c | 5 +++++ 5 files changed, 67 insertions(+), 24 deletions(-) diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index 8ef68176a5..29c5b8a3c5 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -313,14 +313,16 @@ struct BlockDriver { int GRAPH_RDLOCK_PTR (*bdrv_inactivate)(BlockDriverState *bs); - int (*bdrv_snapshot_create)(BlockDriverState *bs, - QEMUSnapshotInfo *sn_info); - int (*bdrv_snapshot_goto)(BlockDriverState *bs, - const char *snapshot_id); - int (*bdrv_snapshot_delete)(BlockDriverState *bs, - const char *snapshot_id, - const char *name, - Error **errp); + int GRAPH_RDLOCK_PTR (*bdrv_snapshot_create)( + BlockDriverState *bs, QEMUSnapshotInfo *sn_info); + + int GRAPH_UNLOCKED_PTR (*bdrv_snapshot_goto)( + BlockDriverState *bs, const char *snapshot_id); + + int GRAPH_RDLOCK_PTR (*bdrv_snapshot_delete)( + BlockDriverState *bs, const char *snapshot_id, const char *name, + Error **errp); + int (*bdrv_snapshot_list)(BlockDriverState *bs, QEMUSnapshotInfo **psn_info); int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs, diff --git a/include/block/snapshot.h b/include/block/snapshot.h index 50ff924710..d49c5599d9 100644 --- a/include/block/snapshot.h +++ b/include/block/snapshot.h @@ -25,6 +25,7 @@ #ifndef SNAPSHOT_H #define SNAPSHOT_H +#include "block/graph-lock.h" #include "qapi/qapi-builtin-types.h" #define SNAPSHOT_OPT_BASE "snapshot." @@ -59,16 +60,19 @@ bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs, const char *name, QEMUSnapshotInfo *sn_info, Error **errp); -int bdrv_can_snapshot(BlockDriverState *bs); -int bdrv_snapshot_create(BlockDriverState *bs, - QEMUSnapshotInfo *sn_info); -int bdrv_snapshot_goto(BlockDriverState *bs, - const char *snapshot_id, - Error **errp); -int bdrv_snapshot_delete(BlockDriverState *bs, - const char *snapshot_id, - const char *name, - Error **errp); + +int GRAPH_RDLOCK bdrv_can_snapshot(BlockDriverState *bs); + +int GRAPH_RDLOCK +bdrv_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); + +int GRAPH_UNLOCKED +bdrv_snapshot_goto(BlockDriverState *bs, const char *snapshot_id, Error **errp); + +int GRAPH_RDLOCK +bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id, + const char *name, Error **errp); + int bdrv_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_info); int bdrv_snapshot_load_tmp(BlockDriverState *bs, diff --git a/block/snapshot.c b/block/snapshot.c index 633391e8a9..554065578b 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -155,11 +155,15 @@ bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs, * back if the given BDS does not support snapshots. * Return NULL if there is no BDS to (safely) fall back to. */ -static BdrvChild *bdrv_snapshot_fallback_child(BlockDriverState *bs) +static BdrvChild * GRAPH_RDLOCK +bdrv_snapshot_fallback_child(BlockDriverState *bs) { BdrvChild *fallback = bdrv_primary_child(bs); BdrvChild *child; + GLOBAL_STATE_CODE(); + assert_bdrv_graph_readable(); + /* We allow fallback only to primary child */ if (!fallback) { return NULL; @@ -182,8 +186,10 @@ static BdrvChild *bdrv_snapshot_fallback_child(BlockDriverState *bs) return fallback; } -static BlockDriverState *bdrv_snapshot_fallback(BlockDriverState *bs) +static BlockDriverState * GRAPH_RDLOCK +bdrv_snapshot_fallback(BlockDriverState *bs) { + GLOBAL_STATE_CODE(); return child_bs(bdrv_snapshot_fallback_child(bs)); } @@ -254,7 +260,10 @@ int bdrv_snapshot_goto(BlockDriverState *bs, return ret; } + bdrv_graph_rdlock_main_loop(); fallback = bdrv_snapshot_fallback_child(bs); + bdrv_graph_rdunlock_main_loop(); + if (fallback) { QDict *options; QDict *file_options; @@ -374,10 +383,12 @@ int bdrv_snapshot_delete(BlockDriverState *bs, int bdrv_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_info) { + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + BlockDriver *drv = bs->drv; BlockDriverState *fallback_bs = bdrv_snapshot_fallback(bs); - GLOBAL_STATE_CODE(); if (!drv) { return -ENOMEDIUM; } @@ -498,6 +509,9 @@ bdrv_all_get_snapshot_devices(bool has_devices, strList *devices, static bool GRAPH_RDLOCK bdrv_all_snapshots_includes_bs(BlockDriverState *bs) { + GLOBAL_STATE_CODE(); + assert_bdrv_graph_readable(); + if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { return false; } @@ -595,11 +609,15 @@ int bdrv_all_goto_snapshot(const char *name, { g_autoptr(GList) bdrvs = NULL; GList *iterbdrvs; + int ret; GLOBAL_STATE_CODE(); - GRAPH_RDLOCK_GUARD_MAINLOOP(); - if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) { + bdrv_graph_rdlock_main_loop(); + ret = bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp); + bdrv_graph_rdunlock_main_loop(); + + if (ret < 0) { return -1; } @@ -608,9 +626,14 @@ int bdrv_all_goto_snapshot(const char *name, BlockDriverState *bs = iterbdrvs->data; AioContext *ctx = bdrv_get_aio_context(bs); int ret = 0; + bool all_snapshots_includes_bs; aio_context_acquire(ctx); - if (devices || bdrv_all_snapshots_includes_bs(bs)) { + bdrv_graph_rdlock_main_loop(); + all_snapshots_includes_bs = bdrv_all_snapshots_includes_bs(bs); + bdrv_graph_rdunlock_main_loop(); + + if (devices || all_snapshots_includes_bs) { ret = bdrv_snapshot_goto(bs, name, errp); } aio_context_release(ctx); diff --git a/blockdev.c b/blockdev.c index b6b7c44288..43e0c4ddf2 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1138,6 +1138,9 @@ SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device, SnapshotInfo *info = NULL; int ret; + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + bs = qmp_get_root_bs(device, errp); if (!bs) { return NULL; @@ -1223,6 +1226,9 @@ static void internal_snapshot_action(BlockdevSnapshotInternal *internal, AioContext *aio_context; int ret1; + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + tran_add(tran, &internal_snapshot_drv, state); device = internal->device; @@ -1311,6 +1317,9 @@ static void internal_snapshot_abort(void *opaque) AioContext *aio_context; Error *local_error = NULL; + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + if (!state->created) { return; } diff --git a/qemu-img.c b/qemu-img.c index 6068ab0d27..5a74e9b10e 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3470,7 +3470,10 @@ static int img_snapshot(int argc, char **argv) sn.date_sec = rt / G_USEC_PER_SEC; sn.date_nsec = (rt % G_USEC_PER_SEC) * 1000; + bdrv_graph_rdlock_main_loop(); ret = bdrv_snapshot_create(bs, &sn); + bdrv_graph_rdunlock_main_loop(); + if (ret) { error_report("Could not create snapshot '%s': %s", snapshot_name, strerror(-ret)); @@ -3486,6 +3489,7 @@ static int img_snapshot(int argc, char **argv) break; case SNAPSHOT_DELETE: + bdrv_graph_rdlock_main_loop(); ret = bdrv_snapshot_find(bs, &sn, snapshot_name); if (ret < 0) { error_report("Could not delete snapshot '%s': snapshot not " @@ -3499,6 +3503,7 @@ static int img_snapshot(int argc, char **argv) ret = 1; } } + bdrv_graph_rdunlock_main_loop(); break; }