From patchwork Fri Nov 11 16:47:15 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [03/10] qed: convert to .bdrv_co_is_allocated() Date: Fri, 11 Nov 2011 06:47:15 -0000 From: Stefan Hajnoczi X-Patchwork-Id: 125217 Message-Id: <1321030042-20446-4-git-send-email-stefanha@linux.vnet.ibm.com> To: Cc: Kevin Wolf , Paolo Bonzini , Marcelo Tosatti , Stefan Hajnoczi The bdrv_qed_is_allocated() function is a synchronous wrapper around qed_find_cluster(), which performs the cluster lookup. In order to convert the synchronous function to a coroutine function we yield instead of using qemu_aio_wait(). Note that QED's cache is already safe for parallel requests so no locking is needed. Signed-off-by: Stefan Hajnoczi --- block/qed.c | 15 +++++++++++---- 1 files changed, 11 insertions(+), 4 deletions(-) diff --git a/block/qed.c b/block/qed.c index d032a45..8a05445 100644 --- a/block/qed.c +++ b/block/qed.c @@ -651,6 +651,7 @@ static int bdrv_qed_create(const char *filename, QEMUOptionParameter *options) } typedef struct { + Coroutine *co; int is_allocated; int *pnum; } QEDIsAllocatedCB; @@ -660,10 +661,14 @@ static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t l QEDIsAllocatedCB *cb = opaque; *cb->pnum = len / BDRV_SECTOR_SIZE; cb->is_allocated = (ret == QED_CLUSTER_FOUND || ret == QED_CLUSTER_ZERO); + if (cb->co) { + qemu_coroutine_enter(cb->co, NULL); + } } -static int bdrv_qed_is_allocated(BlockDriverState *bs, int64_t sector_num, - int nb_sectors, int *pnum) +static int coroutine_fn bdrv_qed_co_is_allocated(BlockDriverState *bs, + int64_t sector_num, + int nb_sectors, int *pnum) { BDRVQEDState *s = bs->opaque; uint64_t pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE; @@ -676,8 +681,10 @@ static int bdrv_qed_is_allocated(BlockDriverState *bs, int64_t sector_num, qed_find_cluster(s, &request, pos, len, qed_is_allocated_cb, &cb); + /* Now sleep if the callback wasn't invoked immediately */ while (cb.is_allocated == -1) { - qemu_aio_wait(); + cb.co = qemu_coroutine_self(); + qemu_coroutine_yield(); } qed_unref_l2_cache_entry(request.l2_table); @@ -1475,7 +1482,7 @@ static BlockDriver bdrv_qed = { .bdrv_open = bdrv_qed_open, .bdrv_close = bdrv_qed_close, .bdrv_create = bdrv_qed_create, - .bdrv_is_allocated = bdrv_qed_is_allocated, + .bdrv_co_is_allocated = bdrv_qed_co_is_allocated, .bdrv_make_empty = bdrv_qed_make_empty, .bdrv_aio_readv = bdrv_qed_aio_readv, .bdrv_aio_writev = bdrv_qed_aio_writev,