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: 10516177 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1E21D6020F for ; Tue, 10 Jul 2018 06:42:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0C68A1FF40 for ; Tue, 10 Jul 2018 06:42:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F30FD252D5; Tue, 10 Jul 2018 06:42:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 74EBD1FF40 for ; Tue, 10 Jul 2018 06:42:08 +0000 (UTC) Received: from localhost ([::1]:46105 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcmLf-0000e1-Q2 for patchwork-qemu-devel@patchwork.kernel.org; Tue, 10 Jul 2018 02:42:07 -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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP 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);