From c64f387854e68afb0fb047953bcadb1d0d9b34f4 Mon Sep 17 00:00:00 2001 From: Jeffrey Cody Date: Wed, 21 Mar 2012 21:54:41 +0100 Subject: [PATCH 14/55] block: add .bdrv_co_is_allocated() RH-Author: Jeffrey Cody Message-id: <1541f0f979f112cfa4bf912bb34d62dbf117d955.1332362400.git.jcody@redhat.com> Patchwork-id: 38864 O-Subject: [RHEL6.3 qemu-kvm PATCH v8 14/54] block: add .bdrv_co_is_allocated() Bugzilla: 582475 RH-Acked-by: Paolo Bonzini RH-Acked-by: Marcelo Tosatti RH-Acked-by: Kevin Wolf 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 (cherry picked from commit 376ae3f1cb5a08f53c9425bfaf90b3f70ab240f1) Signed-off-by: Stefan Hajnoczi Signed-off-by: Anthony Liguori Signed-off-by: Jeff Cody --- block.c | 37 +++++++++++++++++++++++++++++++++++++ block_int.h | 2 ++ 2 files changed, 39 insertions(+), 0 deletions(-) Signed-off-by: Michal Novotny --- block.c | 37 +++++++++++++++++++++++++++++++++++++ block_int.h | 2 ++ 2 files changed, 39 insertions(+), 0 deletions(-) diff --git a/block.c b/block.c index 1db27aa..61e1882 100644 --- a/block.c +++ b/block.c @@ -1756,6 +1756,26 @@ 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, @@ -1771,6 +1791,23 @@ 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 8446fe6..5c564ae 100644 --- a/block_int.h +++ b/block_int.h @@ -85,6 +85,8 @@ struct BlockDriver { int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs); 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); int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs, int num_reqs); -- 1.7.7.6