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 8F716C5AD49 for ; Fri, 30 May 2025 15:12:30 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uL1Op-0002ux-VD; Fri, 30 May 2025 11:11:59 -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 1uL1On-0002sm-7G; Fri, 30 May 2025 11:11:57 -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 1uL1Ok-0002Fr-Uf; Fri, 30 May 2025 11:11:56 -0400 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id A0A6244A8C; Fri, 30 May 2025 17:11:43 +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 v4 18/48] blockdev: drain while unlocked in external_snapshot_action() Date: Fri, 30 May 2025 17:10:55 +0200 Message-Id: <20250530151125.955508-19-f.ebner@proxmox.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250530151125.955508-1-f.ebner@proxmox.com> References: <20250530151125.955508-1-f.ebner@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org This is in preparation to mark bdrv_drained_begin() as GRAPH_UNLOCKED. Signed-off-by: Fiona Ebner --- 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(TransactionAction *action, const char *new_image_file; ExternalSnapshotState *state = g_new0(ExternalSnapshotState, 1); uint64_t perm, shared; + BlockDriverState *check_bs; /* TODO We'll eventually have to take a writer lock in this function */ - GRAPH_RDLOCK_GUARD_MAINLOOP(); + bdrv_graph_rdlock_main_loop(); tran_add(tran, &external_snapshot_drv, state); @@ -1412,11 +1413,25 @@ static void external_snapshot_action(TransactionAction *action, state->old_bs = bdrv_lookup_bs(device, node_name, errp); if (!state->old_bs) { + bdrv_graph_rdunlock_main_loop(); return; } + /* 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 = bdrv_lookup_bs(device, node_name, errp); + if (state->old_bs != check_bs) { + if (check_bs) { + error_setg(errp, "Block node of device '%s' unexpectedly changed", + device); + } /* else errp is already set */ + return; + } if (!bdrv_is_inserted(state->old_bs)) { error_setg(errp, "Device '%s' has no medium", -- 2.39.5