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 97B41C5AD49 for ; Fri, 30 May 2025 15:15:26 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uL1Om-0002rD-HS; Fri, 30 May 2025 11:11:56 -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 1uL1Oj-0002pp-Ev; Fri, 30 May 2025 11:11:53 -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 1uL1Og-0002EL-QW; Fri, 30 May 2025 11:11:53 -0400 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 62B954489D; Fri, 30 May 2025 17:11:40 +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 02/48] block: move drain outside of read-locked bdrv_reopen_queue_child() Date: Fri, 30 May 2025 17:10:39 +0200 Message-Id: <20250530151125.955508-3-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. More granular draining is not trivially possible, because bdrv_reopen_queue_child() can recursively call itself. Signed-off-by: Fiona Ebner Reviewed-by: Kevin Wolf --- block.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/block.c b/block.c index a5399888ba..3065d5c91e 100644 --- a/block.c +++ b/block.c @@ -4358,7 +4358,7 @@ bdrv_recurse_has_child(BlockDriverState *bs, BlockDriverState *child) * returns a pointer to bs_queue, which is either the newly allocated * bs_queue, or the existing bs_queue being used. * - * bs is drained here and undrained by bdrv_reopen_queue_free(). + * bs must be drained. */ static BlockReopenQueue * GRAPH_RDLOCK bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, BlockDriverState *bs, @@ -4377,12 +4377,7 @@ bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, BlockDriverState *bs, GLOBAL_STATE_CODE(); - /* - * Strictly speaking, draining is illegal under GRAPH_RDLOCK. We know that - * we've been called with bdrv_graph_rdlock_main_loop(), though, so it's ok - * in practice. - */ - bdrv_drained_begin(bs); + assert(bs->quiesce_counter > 0); if (bs_queue == NULL) { bs_queue = g_new0(BlockReopenQueue, 1); @@ -4522,6 +4517,12 @@ BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, QDict *options, bool keep_old_opts) { GLOBAL_STATE_CODE(); + + if (bs_queue == NULL) { + /* Paired with bdrv_drain_all_end() in bdrv_reopen_queue_free(). */ + bdrv_drain_all_begin(); + } + GRAPH_RDLOCK_GUARD_MAINLOOP(); return bdrv_reopen_queue_child(bs_queue, bs, options, NULL, 0, false, @@ -4534,12 +4535,14 @@ void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue) if (bs_queue) { BlockReopenQueueEntry *bs_entry, *next; QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { - bdrv_drained_end(bs_entry->state.bs); qobject_unref(bs_entry->state.explicit_options); qobject_unref(bs_entry->state.options); g_free(bs_entry); } g_free(bs_queue); + + /* Paired with bdrv_drain_all_begin() in bdrv_reopen_queue(). */ + bdrv_drain_all_end(); } } -- 2.39.5