From: Fam Zheng <f...@redhat.com> Currently all drivers that support .bdrv_aio_ioctl also implement .bdrv_ioctl redundantly. To track ioctl requests in block layer it is easier if we unify the two paths, because we'll need to run it in a coroutine, as required by tracked_request_begin. While we're at it, use .bdrv_aio_ioctl plus aio_poll() to emulate bdrv_ioctl().
Signed-off-by: Fam Zheng <f...@redhat.com> Message-id: 1447064214-29930-7-git-send-email-f...@redhat.com Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> --- block/io.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 92 insertions(+), 9 deletions(-) diff --git a/block/io.c b/block/io.c index 324ae5a..4ecb171 100644 --- a/block/io.c +++ b/block/io.c @@ -2528,26 +2528,109 @@ int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) return rwco.ret; } +typedef struct { + CoroutineIOCompletion *co; + QEMUBH *bh; +} BdrvIoctlCompletionData; + +static void bdrv_ioctl_bh_cb(void *opaque) +{ + BdrvIoctlCompletionData *data = opaque; + + bdrv_co_io_em_complete(data->co, -ENOTSUP); + qemu_bh_delete(data->bh); +} + +static int bdrv_co_do_ioctl(BlockDriverState *bs, int req, void *buf) +{ + BlockDriver *drv = bs->drv; + BdrvTrackedRequest tracked_req; + CoroutineIOCompletion co = { + .coroutine = qemu_coroutine_self(), + }; + BlockAIOCB *acb; + + tracked_request_begin(&tracked_req, bs, 0, 0, BDRV_TRACKED_IOCTL); + if (!drv || !drv->bdrv_aio_ioctl) { + co.ret = -ENOTSUP; + goto out; + } + + acb = drv->bdrv_aio_ioctl(bs, req, buf, bdrv_co_io_em_complete, &co); + if (!acb) { + BdrvIoctlCompletionData *data = g_new(BdrvIoctlCompletionData, 1); + data->bh = aio_bh_new(bdrv_get_aio_context(bs), + bdrv_ioctl_bh_cb, data); + data->co = &co; + qemu_bh_schedule(data->bh); + } + qemu_coroutine_yield(); +out: + tracked_request_end(&tracked_req); + return co.ret; +} + +typedef struct { + BlockDriverState *bs; + int req; + void *buf; + int ret; +} BdrvIoctlCoData; + +static void coroutine_fn bdrv_co_ioctl_entry(void *opaque) +{ + BdrvIoctlCoData *data = opaque; + data->ret = bdrv_co_do_ioctl(data->bs, data->req, data->buf); +} + /* needed for generic scsi interface */ - int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) { - BlockDriver *drv = bs->drv; + BdrvIoctlCoData data = { + .bs = bs, + .req = req, + .buf = buf, + .ret = -EINPROGRESS, + }; - if (drv && drv->bdrv_ioctl) - return drv->bdrv_ioctl(bs, req, buf); - return -ENOTSUP; + if (qemu_in_coroutine()) { + /* Fast-path if already in coroutine context */ + bdrv_co_ioctl_entry(&data); + } else { + Coroutine *co = qemu_coroutine_create(bdrv_co_ioctl_entry); + qemu_coroutine_enter(co, &data); + } + while (data.ret == -EINPROGRESS) { + aio_poll(bdrv_get_aio_context(bs), true); + } + return data.ret; +} + +static void coroutine_fn bdrv_co_aio_ioctl_entry(void *opaque) +{ + BlockAIOCBCoroutine *acb = opaque; + acb->req.error = bdrv_co_do_ioctl(acb->common.bs, + acb->req.req, acb->req.buf); + bdrv_co_complete(acb); } BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, unsigned long int req, void *buf, BlockCompletionFunc *cb, void *opaque) { - BlockDriver *drv = bs->drv; + BlockAIOCBCoroutine *acb = qemu_aio_get(&bdrv_em_co_aiocb_info, + bs, cb, opaque); + Coroutine *co; - if (drv && drv->bdrv_aio_ioctl) - return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque); - return NULL; + acb->need_bh = true; + acb->req.error = -EINPROGRESS; + acb->req.req = req; + acb->req.buf = buf; + co = qemu_coroutine_create(bdrv_co_aio_ioctl_entry); + qemu_coroutine_enter(co, acb); + + bdrv_co_maybe_schedule_bh(acb); + return &acb->common; } void *qemu_blockalign(BlockDriverState *bs, size_t size) -- 2.5.0