From patchwork Fri Oct 11 15:05:07 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 282878 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 037B62C0199 for ; Sat, 12 Oct 2013 04:42:16 +1100 (EST) Received: from localhost ([::1]:54856 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VUeP7-0006fi-T4 for incoming@patchwork.ozlabs.org; Fri, 11 Oct 2013 11:13:25 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42957) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VUeIN-00078Q-Tb for qemu-devel@nongnu.org; Fri, 11 Oct 2013 11:06:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VUeII-0005Gs-PG for qemu-devel@nongnu.org; Fri, 11 Oct 2013 11:06:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:24242) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VUeII-0005Gk-HA for qemu-devel@nongnu.org; Fri, 11 Oct 2013 11:06:22 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r9BF6Lag011882 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 11 Oct 2013 11:06:21 -0400 Received: from dhcp-200-207.str.redhat.com (dhcp-192-197.str.redhat.com [10.33.192.197]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id r9BF5s2Y006329; Fri, 11 Oct 2013 11:06:19 -0400 From: Kevin Wolf To: anthony@codemonkey.ws Date: Fri, 11 Oct 2013 17:05:07 +0200 Message-Id: <1381503951-27985-18-git-send-email-kwolf@redhat.com> In-Reply-To: <1381503951-27985-1-git-send-email-kwolf@redhat.com> References: <1381503951-27985-1-git-send-email-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-MIME-Autoconverted: from 8bit to quoted-printable by mx1.redhat.com id r9BF6Lag011882 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [Qemu-devel] [PULL 17/61] block: Add BlockDriver.bdrv_check_ext_snapshot. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Benoît Canet This field is used by blkverify to disable external snapshots creation. It will also be used by block filters like quorum to disable external snapshot creation. Signed-off-by: Benoit Canet Reviewed-by: Max Reitz Signed-off-by: Kevin Wolf --- block.c | 19 +++++++++++++++++++ block/blkverify.c | 2 ++ blockdev.c | 5 +++++ include/block/block.h | 14 ++++++++++++++ include/block/block_int.h | 6 ++++++ 5 files changed, 46 insertions(+) diff --git a/block.c b/block.c index d86efad..beea027 100644 --- a/block.c +++ b/block.c @@ -4647,3 +4647,22 @@ int bdrv_amend_options(BlockDriverState *bs, QEMUOptionParameter *options) } return bs->drv->bdrv_amend_options(bs, options); } + +ExtSnapshotPerm bdrv_check_ext_snapshot(BlockDriverState *bs) +{ + if (bs->drv->bdrv_check_ext_snapshot) { + return bs->drv->bdrv_check_ext_snapshot(bs); + } + + if (bs->file && bs->file->drv && bs->file->drv->bdrv_check_ext_snapshot) { + return bs->file->drv->bdrv_check_ext_snapshot(bs); + } + + /* external snapshots are allowed by default */ + return EXT_SNAPSHOT_ALLOWED; +} + +ExtSnapshotPerm bdrv_check_ext_snapshot_forbidden(BlockDriverState *bs) +{ + return EXT_SNAPSHOT_FORBIDDEN; +} diff --git a/block/blkverify.c b/block/blkverify.c index bff95d2..1e8e6d9 100644 --- a/block/blkverify.c +++ b/block/blkverify.c @@ -417,6 +417,8 @@ static BlockDriver bdrv_blkverify = { .bdrv_aio_readv = blkverify_aio_readv, .bdrv_aio_writev = blkverify_aio_writev, .bdrv_aio_flush = blkverify_aio_flush, + + .bdrv_check_ext_snapshot = bdrv_check_ext_snapshot_forbidden, }; static void bdrv_blkverify_init(void) diff --git a/blockdev.c b/blockdev.c index 8c83f6f..a91d5a8 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1131,6 +1131,11 @@ static void external_snapshot_prepare(BlkTransactionState *common, } } + if (bdrv_check_ext_snapshot(state->old_bs) != EXT_SNAPSHOT_ALLOWED) { + error_set(errp, QERR_FEATURE_DISABLED, "snapshot"); + return; + } + flags = state->old_bs->open_flags; /* create new image w/backing file */ diff --git a/include/block/block.h b/include/block/block.h index 0d4d5c3..3560deb 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -248,6 +248,20 @@ int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix); int bdrv_amend_options(BlockDriverState *bs_new, QEMUOptionParameter *options); +/* external snapshots */ + +typedef enum { + EXT_SNAPSHOT_ALLOWED, + EXT_SNAPSHOT_FORBIDDEN, +} ExtSnapshotPerm; + +/* return EXT_SNAPSHOT_ALLOWED if external snapshot is allowed + * return EXT_SNAPSHOT_FORBIDDEN if external snapshot is forbidden + */ +ExtSnapshotPerm bdrv_check_ext_snapshot(BlockDriverState *bs); +/* helper used to forbid external snapshots like in blkverify */ +ExtSnapshotPerm bdrv_check_ext_snapshot_forbidden(BlockDriverState *bs); + /* async block I/O */ typedef void BlockDriverDirtyHandler(BlockDriverState *bs, int64_t sector, int sector_num); diff --git a/include/block/block_int.h b/include/block/block_int.h index 17b26b2..a48731d 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -67,6 +67,12 @@ typedef struct BdrvTrackedRequest { struct BlockDriver { const char *format_name; int instance_size; + + /* if not defined external snapshots are allowed + * future block filters will query their children to build the response + */ + ExtSnapshotPerm (*bdrv_check_ext_snapshot)(BlockDriverState *bs); + int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename); int (*bdrv_probe_device)(const char *filename);