From patchwork Tue Jul 10 06:31:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 941828 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 41Pt0J6rsXz9rxs for ; Tue, 10 Jul 2018 16:41:52 +1000 (AEST) Received: from localhost ([::1]:46104 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcmLO-0000NM-L2 for incoming@patchwork.ozlabs.org; Tue, 10 Jul 2018 02:41:50 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50477) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcmCr-0002Eu-VV for qemu-devel@nongnu.org; Tue, 10 Jul 2018 02:33:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fcmCq-000812-RR for qemu-devel@nongnu.org; Tue, 10 Jul 2018 02:33:02 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:47890 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fcmCk-0007zr-9S; Tue, 10 Jul 2018 02:32:54 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D19AE7A7EB; Tue, 10 Jul 2018 06:32:53 +0000 (UTC) Received: from lemon.usersys.redhat.com (ovpn-12-114.pek2.redhat.com [10.72.12.114]) by smtp.corp.redhat.com (Postfix) with ESMTP id AF4FC16873; Tue, 10 Jul 2018 06:32:48 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Tue, 10 Jul 2018 14:31:24 +0800 Message-Id: <20180710063124.2263-11-famz@redhat.com> In-Reply-To: <20180710063124.2263-1-famz@redhat.com> References: <20180710063124.2263-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Tue, 10 Jul 2018 06:32:53 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Tue, 10 Jul 2018 06:32:53 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'famz@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v3 10/10] block: Use common write req handling in truncate X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , vsementsov@virtuozzo.com, Fam Zheng , qemu-block@nongnu.org, John Snow , Jeff Cody , Max Reitz , Stefan Hajnoczi , Paolo Bonzini Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Truncation is the last to convert from open coded req handling to reusing helpers. This time the permission check in prepare has to adapt to the new caller: it checks a different permission bit, and doesn't trigger the before write notifier. Also, truncation should always trigger a bs->total_sectors update and in turn call parent resize_cb. Update the condition in finish helper, too. It's intended to do a duplicated bs->read_only check before calling bdrv_co_write_req_prepare() so that we can be more informative with the error message, as bdrv_co_write_req_prepare() doesn't have Error parameter. Signed-off-by: Fam Zheng --- block/io.c | 57 ++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 36 insertions(+), 21 deletions(-) diff --git a/block/io.c b/block/io.c index e3e2d5286d..abcb8b3de6 100644 --- a/block/io.c +++ b/block/io.c @@ -1582,14 +1582,24 @@ bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, uint64_t bytes, is_request_serialising_and_aligned(req)); assert(req->overlap_offset <= offset); assert(offset + bytes <= req->overlap_offset + req->overlap_bytes); - - if (flags & BDRV_REQ_WRITE_UNCHANGED) { - assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE)); - } else { - assert(child->perm & BLK_PERM_WRITE); - } assert(end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE); - return notifier_with_return_list_notify(&bs->before_write_notifiers, req); + + switch (req->type) { + case BDRV_TRACKED_WRITE: + case BDRV_TRACKED_DISCARD: + if (flags & BDRV_REQ_WRITE_UNCHANGED) { + assert(child->perm & (BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE)); + } else { + assert(child->perm & BLK_PERM_WRITE); + } + return notifier_with_return_list_notify(&bs->before_write_notifiers, + req); + case BDRV_TRACKED_TRUNCATE: + assert(child->perm & BLK_PERM_RESIZE); + return 0; + default: + abort(); + } } static inline void coroutine_fn @@ -1608,8 +1618,9 @@ bdrv_co_write_req_finish(BdrvChild *child, int64_t offset, uint64_t bytes, * beyond EOF cannot expand the image anyway. * */ if (ret == 0 && - end_sector > bs->total_sectors && - req->type != BDRV_TRACKED_DISCARD) { + (req->type == BDRV_TRACKED_TRUNCATE || + end_sector > bs->total_sectors) && + req->type != BDRV_TRACKED_DISCARD) { bs->total_sectors = end_sector; bdrv_parent_cb_resize(bs); bdrv_dirty_bitmap_truncate(bs, end_sector << BDRV_SECTOR_BITS); @@ -3088,7 +3099,6 @@ int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, int64_t old_size, new_bytes; int ret; - assert(child->perm & BLK_PERM_RESIZE); /* if bs->drv == NULL, bs is closed, so there's nothing to do here */ if (!drv) { @@ -3121,7 +3131,18 @@ int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, * concurrently or they might be overwritten by preallocation. */ if (new_bytes) { mark_request_serialising(&req, 1); - wait_serialising_requests(&req); + } + if (bs->read_only) { + error_setg(errp, "Image is read-only"); + ret = -EACCES; + goto out; + } + ret = bdrv_co_write_req_prepare(child, offset - new_bytes, new_bytes, &req, + 0); + if (ret < 0) { + error_setg_errno(errp, -ret, + "Failed to prepare request for truncation"); + goto out; } if (!drv->bdrv_co_truncate) { @@ -3133,13 +3154,6 @@ int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, ret = -ENOTSUP; goto out; } - if (bs->read_only) { - error_setg(errp, "Image is read-only"); - ret = -EACCES; - goto out; - } - - assert(!(bs->open_flags & BDRV_O_INACTIVE)); ret = drv->bdrv_co_truncate(bs, offset, prealloc, errp); if (ret < 0) { @@ -3151,9 +3165,10 @@ int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, } else { offset = bs->total_sectors * BDRV_SECTOR_SIZE; } - bdrv_dirty_bitmap_truncate(bs, offset); - bdrv_parent_cb_resize(bs); - atomic_inc(&bs->write_gen); + /* It's possible that truncation succeeded but refresh_total_sectors + * failed, but the latter doesn't affect how we should finish the request. + * Pass 0 as the last parameter so that dirty bitmaps etc. are handled. */ + bdrv_co_write_req_finish(child, offset - new_bytes, new_bytes, &req, 0); out: tracked_request_end(&req);