From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:54131) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RPvu5-0008UE-0w for qemu-devel@nongnu.org; Mon, 14 Nov 2011 07:44:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RPvu4-00049F-3A for qemu-devel@nongnu.org; Mon, 14 Nov 2011 07:44:48 -0500 Received: from mtagate3.uk.ibm.com ([194.196.100.163]:52283) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RPvu3-00048a-RA for qemu-devel@nongnu.org; Mon, 14 Nov 2011 07:44:48 -0500 Received: from d06nrmr1707.portsmouth.uk.ibm.com (d06nrmr1707.portsmouth.uk.ibm.com [9.149.39.225]) by mtagate3.uk.ibm.com (8.13.1/8.13.1) with ESMTP id pAECijPc015287 for ; Mon, 14 Nov 2011 12:44:45 GMT Received: from d06av01.portsmouth.uk.ibm.com (d06av01.portsmouth.uk.ibm.com [9.149.37.212]) by d06nrmr1707.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id pAECij3L2523192 for ; Mon, 14 Nov 2011 12:44:45 GMT Received: from d06av01.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av01.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id pAECiinF006256 for ; Mon, 14 Nov 2011 05:44:45 -0700 From: Stefan Hajnoczi Date: Mon, 14 Nov 2011 12:44:19 +0000 Message-Id: <1321274666-14041-3-git-send-email-stefanha@linux.vnet.ibm.com> In-Reply-To: <1321274666-14041-1-git-send-email-stefanha@linux.vnet.ibm.com> References: <1321274666-14041-1-git-send-email-stefanha@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH v2 2/9] block: add .bdrv_co_is_allocated() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Paolo Bonzini , Marcelo Tosatti , Stefan Hajnoczi This patch adds the .bdrv_co_is_allocated() interface which is identical to .bdrv_is_allocated() but runs in coroutine context. Running in coroutine context implies that other coroutines might be performing I/O at the same time. Therefore it must be safe to run while the following BlockDriver functions are in-flight: .bdrv_co_readv() .bdrv_co_writev() .bdrv_co_flush() .bdrv_co_is_allocated() The new .bdrv_co_is_allocated() interface is useful because it can be used when a VM is running, whereas .bdrv_is_allocated() is a synchronous interface that does not cope with parallel requests. Signed-off-by: Stefan Hajnoczi --- block.c | 37 +++++++++++++++++++++++++++++++++++++ block_int.h | 2 ++ 2 files changed, 39 insertions(+), 0 deletions(-) diff --git a/block.c b/block.c index ab68e53..69989b0 100644 --- a/block.c +++ b/block.c @@ -1887,6 +1887,26 @@ int bdrv_has_zero_init(BlockDriverState *bs) return 1; } +typedef struct BdrvCoIsAllocatedData { + BlockDriverState *bs; + int64_t sector_num; + int nb_sectors; + int *pnum; + int ret; + bool done; +} BdrvCoIsAllocatedData; + +/* Coroutine wrapper for bdrv_is_allocated() */ +static void coroutine_fn bdrv_is_allocated_co_entry(void *opaque) +{ + BdrvCoIsAllocatedData *data = opaque; + BlockDriverState *bs = data->bs; + + data->ret = bs->drv->bdrv_co_is_allocated(bs, data->sector_num, + data->nb_sectors, data->pnum); + data->done = true; +} + /* * Returns true iff the specified sector is present in the disk image. Drivers * not implementing the functionality are assumed to not support backing files, @@ -1902,6 +1922,23 @@ int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum) { int64_t n; + if (bs->drv->bdrv_co_is_allocated) { + Coroutine *co; + BdrvCoIsAllocatedData data = { + .bs = bs, + .sector_num = sector_num, + .nb_sectors = nb_sectors, + .pnum = pnum, + .done = false, + }; + + co = qemu_coroutine_create(bdrv_is_allocated_co_entry); + qemu_coroutine_enter(co, &data); + while (!data.done) { + qemu_aio_wait(); + } + return data.ret; + } if (!bs->drv->bdrv_is_allocated) { if (sector_num >= bs->total_sectors) { *pnum = 0; diff --git a/block_int.h b/block_int.h index b537d5a..01f73ba 100644 --- a/block_int.h +++ b/block_int.h @@ -103,6 +103,8 @@ struct BlockDriver { int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs, int64_t sector_num, int nb_sectors); + int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, int *pnum); /* * Flushes all data that was already written to the OS all the way down to -- 1.7.7.1