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block: Emulate bdrv_ioctl with bdrv_aio_ioctl and track both

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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 <famz@redhat.com>
Message-id: 1447064214-29930-7-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Fam Zheng 2015-11-09 18:16:51 +08:00 committed by Kevin Wolf
parent 8b45f6878d
commit 5c5ae76acb
1 changed files with 92 additions and 9 deletions
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101
block/io.c
View file

@ -2528,26 +2528,109 @@ int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
return rwco.ret;
}
/* needed for generic scsi interface */
typedef struct {
CoroutineIOCompletion *co;
QEMUBH *bh;
} BdrvIoctlCompletionData;
int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
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;
if (drv && drv->bdrv_ioctl)
return drv->bdrv_ioctl(bs, req, buf);
return -ENOTSUP;
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)
{
BdrvIoctlCoData data = {
.bs = bs,
.req = req,
.buf = buf,
.ret = -EINPROGRESS,
};
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)