From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:46449) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXZNX-0000cU-Cd for qemu-devel@nongnu.org; Mon, 05 Dec 2011 09:18:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RXZNK-0000BP-Mm for qemu-devel@nongnu.org; Mon, 05 Dec 2011 09:18:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:21381) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXZNK-00009L-BE for qemu-devel@nongnu.org; Mon, 05 Dec 2011 09:18:34 -0500 From: Kevin Wolf Date: Mon, 5 Dec 2011 15:20:58 +0100 Message-Id: <1323094878-7967-22-git-send-email-kwolf@redhat.com> In-Reply-To: <1323094878-7967-1-git-send-email-kwolf@redhat.com> References: <1323094878-7967-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH 21/41] block: add .bdrv_co_is_allocated() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: anthony@codemonkey.ws Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: 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 Signed-off-by: Kevin Wolf --- block.c | 37 +++++++++++++++++++++++++++++++++++++ block_int.h | 2 ++ 2 files changed, 39 insertions(+), 0 deletions(-) diff --git a/block.c b/block.c index 0d5bee0..611c429 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 e2799e4..d5b5457 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); /* * Invalidate any cached meta-data. -- 1.7.6.4