From nobody Sat Nov 15 22:35:19 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 17477372456771002.616293618843; Tue, 20 May 2025 03:34:05 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uHKFG-00082G-79; Tue, 20 May 2025 06:30:50 -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 1uHKEv-0006zU-QW; Tue, 20 May 2025 06:30:30 -0400 Received: from proxmox-new.maurer-it.com ([94.136.29.106]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uHKEt-00052F-3Q; Tue, 20 May 2025 06:30:29 -0400 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id B817E43BB1; Tue, 20 May 2025 12:30:20 +0200 (CEST) From: Fiona Ebner To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, kwolf@redhat.com, den@virtuozzo.com, andrey.drobyshev@virtuozzo.com, hreitz@redhat.com, stefanha@redhat.com, eblake@redhat.com, jsnow@redhat.com, vsementsov@yandex-team.ru, xiechanglong.d@gmail.com, wencongyang2@huawei.com, berto@igalia.com, fam@euphon.net, ari@tuxera.com Subject: [PATCH v2 18/24] blockdev: drain while unlocked in external_snapshot_action() Date: Tue, 20 May 2025 12:30:06 +0200 Message-Id: <20250520103012.424311-19-f.ebner@proxmox.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250520103012.424311-1-f.ebner@proxmox.com> References: <20250520103012.424311-1-f.ebner@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=94.136.29.106; envelope-from=f.ebner@proxmox.com; helo=proxmox-new.maurer-it.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1747737246724116600 Content-Type: text/plain; charset="utf-8" This is in preparation to mark bdrv_drained_begin() as GRAPH_UNLOCKED. Signed-off-by: Fiona Ebner --- Changes in v2: * Check that associated bs did not change with the drain. blockdev.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/blockdev.c b/blockdev.c index 506755bef1..2e7fda6780 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1377,9 +1377,10 @@ static void external_snapshot_action(TransactionActi= on *action, const char *new_image_file; ExternalSnapshotState *state =3D g_new0(ExternalSnapshotState, 1); uint64_t perm, shared; + BlockDriverState *check_bs; =20 /* TODO We'll eventually have to take a writer lock in this function */ - GRAPH_RDLOCK_GUARD_MAINLOOP(); + bdrv_graph_rdlock_main_loop(); =20 tran_add(tran, &external_snapshot_drv, state); =20 @@ -1412,11 +1413,25 @@ static void external_snapshot_action(TransactionAct= ion *action, =20 state->old_bs =3D bdrv_lookup_bs(device, node_name, errp); if (!state->old_bs) { + bdrv_graph_rdunlock_main_loop(); return; } =20 + /* Need to drain while unlocked. */ + bdrv_graph_rdunlock_main_loop(); /* Paired with .clean() */ bdrv_drained_begin(state->old_bs); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + + /* Make sure the associated bs did not change with the drain. */ + check_bs =3D bdrv_lookup_bs(device, node_name, errp); + if (state->old_bs !=3D check_bs) { + if (check_bs) { + error_setg(errp, "Block node of device '%s' unexpectedly chang= ed", + device); + } /* else errp is already set */ + return; + } =20 if (!bdrv_is_inserted(state->old_bs)) { error_setg(errp, "Device '%s' has no medium", --=20 2.39.5