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block: drop .bdrv_read()/.bdrv_write() emulation 

There is no need to emulate .bdrv_read()/.bdrv_write() since these
interfaces are only called if aio and coroutine interfaces are not
present.  All valid BlockDrivers must implement either sync, aio, or
coroutine interfaces.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2011-10-13 21:09:31 +01:00 committed by Kevin Wolf
parent d8b7e0adf5
commit f8c35c1d59
1 changed files with 3 additions and 72 deletions
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75
block.c
View File

@ -57,10 +57,6 @@ static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque);
static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque);
static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors);
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors);
static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
QEMUIOVector *iov);
@ -197,14 +193,13 @@ void bdrv_register(BlockDriver *bdrv)
bdrv->bdrv_co_readv = bdrv_co_readv_em;
bdrv->bdrv_co_writev = bdrv_co_writev_em;
/* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if
* the block driver lacks aio we need to emulate that too.
*/
if (!bdrv->bdrv_aio_readv) {
/* add AIO emulation layer */
bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
} else if (!bdrv->bdrv_read) {
/* add synchronous IO emulation layer */
bdrv->bdrv_read = bdrv_read_em;
bdrv->bdrv_write = bdrv_write_em;
}
}
@ -2834,70 +2829,6 @@ static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
return &acb->common;
}
/**************************************************************/
/* sync block device emulation */
static void bdrv_rw_em_cb(void *opaque, int ret)
{
*(int *)opaque = ret;
}
static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
int async_ret;
BlockDriverAIOCB *acb;
struct iovec iov;
QEMUIOVector qiov;
async_ret = NOT_DONE;
iov.iov_base = (void *)buf;
iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
qemu_iovec_init_external(&qiov, &iov, 1);
acb = bs->drv->bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
bdrv_rw_em_cb, &async_ret);
if (acb == NULL) {
async_ret = -1;
goto fail;
}
while (async_ret == NOT_DONE) {
qemu_aio_wait();
}
fail:
return async_ret;
}
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
int async_ret;
BlockDriverAIOCB *acb;
struct iovec iov;
QEMUIOVector qiov;
async_ret = NOT_DONE;
iov.iov_base = (void *)buf;
iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
qemu_iovec_init_external(&qiov, &iov, 1);
acb = bs->drv->bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
bdrv_rw_em_cb, &async_ret);
if (acb == NULL) {
async_ret = -1;
goto fail;
}
while (async_ret == NOT_DONE) {
qemu_aio_wait();
}
fail:
return async_ret;
}
void bdrv_init(void)
{
module_call_init(MODULE_INIT_BLOCK);