From nobody Mon Sep 22 03:37:04 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 1758110207624498.56811592518113; Wed, 17 Sep 2025 04:56:47 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uyqlw-0001SH-LS; Wed, 17 Sep 2025 07:56:29 -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 1uyqky-0007hm-D3; Wed, 17 Sep 2025 07:55:28 -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 1uyqkv-0004bv-GD; Wed, 17 Sep 2025 07:55:28 -0400 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 7FB204DC09; Wed, 17 Sep 2025 13:55:20 +0200 (CEST) From: Fiona Ebner To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, fam@euphon.net, stefanha@redhat.com, hreitz@redhat.com, kwolf@redhat.com Subject: [PATCH v2 3/5] block: implement 'resize' callback for child_of_bds class Date: Wed, 17 Sep 2025 13:54:50 +0200 Message-ID: <20250917115509.401015-4-f.ebner@proxmox.com> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250917115509.401015-1-f.ebner@proxmox.com> References: <20250917115509.401015-1-f.ebner@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1758110111502 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_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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1758110209716116601 Content-Type: text/plain; charset="utf-8" If a filtered child is resized, the size of the parent node is now also refreshed (recursively for chains of filtered children). For filter block drivers that do not implement .bdrv_co_getlength(), this commit does not change the current behavior, because bdrv_co_refresh_total_sectors() will used the current size via the passed-in hint. This is the case for block drivers for (some) block jobs, as well as copy-before-write. Block jobs already set up a blocker preventing a QMP block_resize operation while the job is running. That does not directly cover an associated 'file' node of a 'raw' node, but resizing such a 'file' node is already prevented too (backup, commit, mirror and stream were checked). The other case is copy-before-write. This commit does not change the fact that the copy-before-write node still has the same size after its filtered child is resized. Block drivers that do implement .bdrv_co_getlength() and where .is_filter is true, already returned the length of the file child, so there is no change before and after this commit, with two exceptions: 1. preallocate can return an early data_end and otherwise queries the file child, but that special casing is not changed. 2. blkverify returns the length of the test file. This commit does not affect that behavior. Signed-off-by: Fiona Ebner --- Changes in v2: * Check for BDRV_CHILD_FILTERED rather than bs->drv->is_filter which is more generic and for example, also covers the case when the child of a 'raw' node is resized. * Expand commit message. block.c | 12 ++++++++++++ include/block/block_int-common.h | 2 +- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/block.c b/block.c index 8848e9a7ed..cf08e64add 100644 --- a/block.c +++ b/block.c @@ -1497,6 +1497,17 @@ static void GRAPH_WRLOCK bdrv_child_cb_detach(BdrvCh= ild *child) } } =20 +static void coroutine_fn GRAPH_RDLOCK bdrv_child_cb_resize(BdrvChild *chil= d) +{ + BlockDriverState *bs =3D child->opaque; + + if (child->role & BDRV_CHILD_FILTERED) { + /* Best effort, ignore errors. */ + bdrv_co_refresh_total_sectors(bs, bs->total_sectors); + bdrv_co_parent_cb_resize(bs); + } +} + static int bdrv_child_cb_update_filename(BdrvChild *c, BlockDriverState *b= ase, const char *filename, bool backing_mask_protocol, @@ -1529,6 +1540,7 @@ const BdrvChildClass child_of_bds =3D { .detach =3D bdrv_child_cb_detach, .inactivate =3D bdrv_child_cb_inactivate, .change_aio_ctx =3D bdrv_child_cb_change_aio_ctx, + .resize =3D bdrv_child_cb_resize, .update_filename =3D bdrv_child_cb_update_filename, .get_parent_aio_context =3D child_of_bds_get_parent_aio_context, }; diff --git a/include/block/block_int-common.h b/include/block/block_int-com= mon.h index 8a3d427356..c55b35da8e 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -1023,7 +1023,7 @@ struct BdrvChildClass { /* * Notifies the parent that the child was resized. */ - void (*resize)(BdrvChild *child); + void GRAPH_RDLOCK_PTR (*resize)(BdrvChild *child); =20 /* * Returns a name that is supposedly more useful for human users than = the --=20 2.47.2