Instead of registering emulation functions as .bdrv_co_writev, just
directly check whether the function is there or not, and use the AIO
interface if it isn't. This makes the read/write functions more
consistent with how things are done in other places (flush, discard,
etc.)
Signed-off-by: Kevin Wolf <kw...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
---
block/io.c | 126 ++++++++++++++++++++++++-----------------------------------
trace-events | 1 -
2 files changed, 52 insertions(+), 75 deletions(-)
diff --git a/block/io.c b/block/io.c
index c9b2864..86d97c3 100644
--- a/block/io.c
+++ b/block/io.c
@@ -40,12 +40,6 @@ static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockCompletionFunc *cb, void *opaque);
-static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov);
-static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov);
static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
int64_t sector_num,
QEMUIOVector *qiov,
@@ -125,19 +119,13 @@ void bdrv_io_limits_update_group(BlockDriverState *bs,
const char *group)
void bdrv_setup_io_funcs(BlockDriver *bdrv)
{
- /* Block drivers without coroutine functions need emulation */
- if (!bdrv->bdrv_co_readv) {
- 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;
- }
+ /* 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.
+ */
+ 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;
}
}
@@ -800,6 +788,19 @@ int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
return 0;
}
+typedef struct CoroutineIOCompletion {
+ Coroutine *coroutine;
+ int ret;
+} CoroutineIOCompletion;
+
+static void bdrv_co_io_em_complete(void *opaque, int ret)
+{
+ CoroutineIOCompletion *co = opaque;
+
+ co->ret = ret;
+ qemu_coroutine_enter(co->coroutine, NULL);
+}
+
static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags)
@@ -812,7 +813,23 @@ static int coroutine_fn
bdrv_driver_preadv(BlockDriverState *bs,
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS);
- return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+ if (drv->bdrv_co_readv) {
+ return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
+ } else {
+ BlockAIOCB *acb;
+ CoroutineIOCompletion co = {
+ .coroutine = qemu_coroutine_self(),
+ };
+
+ acb = bs->drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
+ bdrv_co_io_em_complete, &co);
+ if (acb == NULL) {
+ return -EIO;
+ } else {
+ qemu_coroutine_yield();
+ return co.ret;
+ }
+ }
}
static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
@@ -831,9 +848,23 @@ static int coroutine_fn
bdrv_driver_pwritev(BlockDriverState *bs,
if (drv->bdrv_co_writev_flags) {
ret = drv->bdrv_co_writev_flags(bs, sector_num, nb_sectors, qiov,
flags);
- } else {
+ } else if (drv->bdrv_co_writev) {
assert(drv->supported_write_flags == 0);
ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
+ } else {
+ BlockAIOCB *acb;
+ CoroutineIOCompletion co = {
+ .coroutine = qemu_coroutine_self(),
+ };
+
+ acb = bs->drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
+ bdrv_co_io_em_complete, &co);
+ if (acb == NULL) {
+ return -EIO;
+ } else {
+ qemu_coroutine_yield();
+ return co.ret;
+ }
}
if (ret == 0 && (flags & BDRV_REQ_FUA) &&
@@ -2351,59 +2382,6 @@ void qemu_aio_unref(void *p)
/**************************************************************/
/* Coroutine block device emulation */
-typedef struct CoroutineIOCompletion {
- Coroutine *coroutine;
- int ret;
-} CoroutineIOCompletion;
-
-static void bdrv_co_io_em_complete(void *opaque, int ret)
-{
- CoroutineIOCompletion *co = opaque;
-
- co->ret = ret;
- qemu_coroutine_enter(co->coroutine, NULL);
-}
-
-static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, QEMUIOVector *iov,
- bool is_write)
-{
- CoroutineIOCompletion co = {
- .coroutine = qemu_coroutine_self(),
- };
- BlockAIOCB *acb;
-
- if (is_write) {
- acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors,
- bdrv_co_io_em_complete, &co);
- } else {
- acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors,
- bdrv_co_io_em_complete, &co);
- }
-
- trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb);
- if (!acb) {
- return -EIO;
- }
- qemu_coroutine_yield();
-
- return co.ret;
-}
-
-static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov)
-{
- return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false);
-}
-
-static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors,
- QEMUIOVector *iov)
-{
- return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true);
-}
-
static void coroutine_fn bdrv_flush_co_entry(void *opaque)
{
RwCo *rwco = opaque;
diff --git a/trace-events b/trace-events
index 8350743..b4acd2a 100644
--- a/trace-events
+++ b/trace-events
@@ -74,7 +74,6 @@ bdrv_co_copy_on_readv(void *bs, int64_t sector_num, int
nb_sector) "bs %p sector
bdrv_co_readv_no_serialising(void *bs, int64_t sector_num, int nb_sector) "bs
%p sector_num %"PRId64" nb_sectors %d"
bdrv_co_writev(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num
%"PRId64" nb_sectors %d"
bdrv_co_write_zeroes(void *bs, int64_t sector_num, int nb_sector, int flags)
"bs %p sector_num %"PRId64" nb_sectors %d flags %#x"
-bdrv_co_io_em(void *bs, int64_t sector_num, int nb_sectors, int is_write, void
*acb) "bs %p sector_num %"PRId64" nb_sectors %d is_write %d acb %p"
bdrv_co_do_copy_on_readv(void *bs, int64_t sector_num, int nb_sectors, int64_t
cluster_sector_num, int cluster_nb_sectors) "bs %p sector_num %"PRId64"
nb_sectors %d cluster_sector_num %"PRId64" cluster_nb_sectors %d"
# block/stream.c
--
1.8.3.1
