From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:47037) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QzC9S-0000Xb-CI for qemu-devel@nongnu.org; Thu, 01 Sep 2011 14:38:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QzC9R-0004Hn-6X for qemu-devel@nongnu.org; Thu, 01 Sep 2011 14:38:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30884) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QzC9Q-0004Hc-SM for qemu-devel@nongnu.org; Thu, 01 Sep 2011 14:38:09 -0400 From: Luiz Capitulino Date: Thu, 1 Sep 2011 15:37:50 -0300 Message-Id: <1314902275-5240-2-git-send-email-lcapitulino@redhat.com> In-Reply-To: <1314902275-5240-1-git-send-email-lcapitulino@redhat.com> References: <1314902275-5240-1-git-send-email-lcapitulino@redhat.com> Subject: [Qemu-devel] [PATCH 1/6] block: Keep track of devices' I/O status List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, aliguori@us.ibm.com, armbru@redhat.com This commit adds support to the BlockDriverState type to keep track of the devices' I/O status. There are three possible status: BDRV_IOS_OK (no error so far), 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 host's underline device and put the VM 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 set back 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 with the I/O status information. Signed-off-by: Luiz Capitulino --- block.c | 32 ++++++++++++++++++++++++++++++++ block.h | 9 +++++++++ block_int.h | 1 + monitor.c | 6 ++++++ 4 files changed, 48 insertions(+), 0 deletions(-) diff --git a/block.c b/block.c index 03a21d8..c54caf2 100644 --- a/block.c +++ b/block.c @@ -220,6 +220,7 @@ BlockDriverState *bdrv_new(const char *device_name) if (device_name[0] != '\0') { QTAILQ_INSERT_TAIL(&bdrv_states, bs, list); } + bs->iostatus = BDRV_IOS_INVAL; return bs; } @@ -3165,6 +3166,37 @@ int bdrv_in_use(BlockDriverState *bs) return bs->in_use; } +void bdrv_iostatus_enable(BlockDriverState *bs) +{ + assert(bs->iostatus == BDRV_IOS_INVAL); + 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_reset(BlockDriverState *bs) +{ + if (bdrv_iostatus_is_enabled(bs)) { + bs->iostatus = BDRV_IOS_OK; + } +} + +void bdrv_iostatus_update(BlockDriverState *bs, int error) +{ + if (bdrv_iostatus_is_enabled(bs) && bs->iostatus == BDRV_IOS_OK) { + bs->iostatus = (abs(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 3ac0b94..24914e0 100644 --- a/block.h +++ b/block.h @@ -51,6 +51,15 @@ 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); +bool bdrv_iostatus_is_enabled(const BlockDriverState *bs); +void bdrv_iostatus_update(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 8a72b80..600801d 100644 --- a/block_int.h +++ b/block_int.h @@ -203,6 +203,7 @@ 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 9807005..69f1b3c 100644 --- a/monitor.c +++ b/monitor.c @@ -1302,6 +1302,11 @@ struct bdrv_iterate_context { int err; }; +static void iostatus_bdrv_it(void *opaque, BlockDriverState *bs) +{ + bdrv_iostatus_reset(bs); +} + /** * do_cont(): Resume emulation. */ @@ -1318,6 +1323,7 @@ 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) { -- 1.7.7.rc0.72.g4b5ea