From patchwork Fri Oct 14 16:48:58 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 119885 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 30411B700E for ; Sat, 15 Oct 2011 05:18:32 +1100 (EST) Received: from localhost ([::1]:53887 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1REkue-0007ht-DQ for incoming@patchwork.ozlabs.org; Fri, 14 Oct 2011 12:47:12 -0400 Received: from eggs.gnu.org ([140.186.70.92]:58691) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1REkts-0005Td-R1 for qemu-devel@nongnu.org; Fri, 14 Oct 2011 12:46:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1REktr-0001AL-CU for qemu-devel@nongnu.org; Fri, 14 Oct 2011 12:46:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58838) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1REktr-0001A9-11 for qemu-devel@nongnu.org; Fri, 14 Oct 2011 12:46:23 -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 p9EGkLRY022443 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 14 Oct 2011 12:46:21 -0400 Received: from dhcp-5-188.str.redhat.com (vpn1-4-247.ams2.redhat.com [10.36.4.247]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p9EGkF2I024913; Fri, 14 Oct 2011 12:46:20 -0400 From: Kevin Wolf To: anthony@codemonkey.ws Date: Fri, 14 Oct 2011 18:48:58 +0200 Message-Id: <1318610959-17971-4-git-send-email-kwolf@redhat.com> In-Reply-To: <1318610959-17971-1-git-send-email-kwolf@redhat.com> References: <1318610959-17971-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH 03/24] block: Keep track of devices' I/O status 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: Luiz Capitulino This commit adds support to the BlockDriverState type to keep track of devices' I/O status. There are three possible status: BDRV_IOS_OK (no error), BDRV_IOS_ENOSPC (no space error) and BDRV_IOS_FAILED (any other error). The distinction between no space and other errors is important because a management application may want to watch for no space in order to extend the space assigned to the VM and put it to run again. Qemu devices supporting the I/O status feature have to enable it explicitly by calling bdrv_iostatus_enable() _and_ have to be configured to stop the VM on errors (ie. werror=stop|enospc or rerror=stop). In case of multiple errors being triggered in sequence only the first one is stored. The I/O status is always reset to BDRV_IOS_OK when the 'cont' command is issued. Next commits will add support to some devices and extend the query-block/info block commands to return the I/O status information. Signed-off-by: Luiz Capitulino Reviewed-by: Markus Armbruster Signed-off-by: Kevin Wolf --- block.c | 40 ++++++++++++++++++++++++++++++++++++++++ block.h | 10 ++++++++++ block_int.h | 1 + monitor.c | 6 ++++++ 4 files changed, 57 insertions(+), 0 deletions(-) diff --git a/block.c b/block.c index e865fab..92ec2c3 100644 --- a/block.c +++ b/block.c @@ -221,6 +221,7 @@ BlockDriverState *bdrv_new(const char *device_name) if (device_name[0] != '\0') { QTAILQ_INSERT_TAIL(&bdrv_states, bs, list); } + bdrv_iostatus_disable(bs); return bs; } @@ -772,6 +773,7 @@ int bdrv_attach_dev(BlockDriverState *bs, void *dev) return -EBUSY; } bs->dev = dev; + bdrv_iostatus_reset(bs); return 0; } @@ -3183,6 +3185,44 @@ int bdrv_in_use(BlockDriverState *bs) return bs->in_use; } +void bdrv_iostatus_enable(BlockDriverState *bs) +{ + bs->iostatus = BDRV_IOS_OK; +} + +/* The I/O status is only enabled if the drive explicitly + * enables it _and_ the VM is configured to stop on errors */ +bool bdrv_iostatus_is_enabled(const BlockDriverState *bs) +{ + return (bs->iostatus != BDRV_IOS_INVAL && + (bs->on_write_error == BLOCK_ERR_STOP_ENOSPC || + bs->on_write_error == BLOCK_ERR_STOP_ANY || + bs->on_read_error == BLOCK_ERR_STOP_ANY)); +} + +void bdrv_iostatus_disable(BlockDriverState *bs) +{ + bs->iostatus = BDRV_IOS_INVAL; +} + +void bdrv_iostatus_reset(BlockDriverState *bs) +{ + if (bdrv_iostatus_is_enabled(bs)) { + bs->iostatus = BDRV_IOS_OK; + } +} + +/* XXX: Today this is set by device models because it makes the implementation + quite simple. However, the block layer knows about the error, so it's + possible to implement this without device models being involved */ +void bdrv_iostatus_set_err(BlockDriverState *bs, int error) +{ + if (bdrv_iostatus_is_enabled(bs) && bs->iostatus == BDRV_IOS_OK) { + assert(error >= 0); + bs->iostatus = error == ENOSPC ? BDRV_IOS_ENOSPC : BDRV_IOS_FAILED; + } +} + void bdrv_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie, int64_t bytes, enum BlockAcctType type) diff --git a/block.h b/block.h index 16bfa0a..e77988e 100644 --- a/block.h +++ b/block.h @@ -77,6 +77,16 @@ typedef enum { BDRV_ACTION_REPORT, BDRV_ACTION_IGNORE, BDRV_ACTION_STOP } BlockMonEventAction; +typedef enum { + BDRV_IOS_INVAL, BDRV_IOS_OK, BDRV_IOS_FAILED, BDRV_IOS_ENOSPC, + BDRV_IOS_MAX +} BlockIOStatus; + +void bdrv_iostatus_enable(BlockDriverState *bs); +void bdrv_iostatus_reset(BlockDriverState *bs); +void bdrv_iostatus_disable(BlockDriverState *bs); +bool bdrv_iostatus_is_enabled(const BlockDriverState *bs); +void bdrv_iostatus_set_err(BlockDriverState *bs, int error); void bdrv_mon_event(const BlockDriverState *bdrv, BlockMonEventAction action, int is_read); void bdrv_info_print(Monitor *mon, const QObject *data); diff --git a/block_int.h b/block_int.h index 8c3b863..f2f4f2d 100644 --- a/block_int.h +++ b/block_int.h @@ -199,6 +199,7 @@ struct BlockDriverState { drivers. They are not used by the block driver */ int cyls, heads, secs, translation; BlockErrorAction on_read_error, on_write_error; + BlockIOStatus iostatus; char device_name[32]; unsigned long *dirty_bitmap; int64_t dirty_count; diff --git a/monitor.c b/monitor.c index 31b212a..1a28956 100644 --- a/monitor.c +++ b/monitor.c @@ -1221,6 +1221,11 @@ struct bdrv_iterate_context { int err; }; +static void iostatus_bdrv_it(void *opaque, BlockDriverState *bs) +{ + bdrv_iostatus_reset(bs); +} + /** * do_cont(): Resume emulation. */ @@ -1237,6 +1242,7 @@ static int do_cont(Monitor *mon, const QDict *qdict, QObject **ret_data) return -1; } + bdrv_iterate(iostatus_bdrv_it, NULL); bdrv_iterate(encrypted_bdrv_it, &context); /* only resume the vm if all keys are set and valid */ if (!context.err) {