block: drop emulation functions that use coroutines

Block drivers that implement coroutine functions used to get sync and
aio wrappers.  This is no longer necessary since all request processing
now happens in a coroutine.  If a block driver implements the coroutine
interface then none of the other interfaces will be invoked.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block.c

@@ -61,12 +61,6 @@ 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 BlockDriverAIOCB *bdrv_co_aio_readv_em(BlockDriverState *bs,
-        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque);
-static BlockDriverAIOCB *bdrv_co_aio_writev_em(BlockDriverState *bs,
-        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque);
 static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
                                          int64_t sector_num, int nb_sectors,
                                          QEMUIOVector *iov);
@@ -84,8 +78,7 @@ static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
                                                int nb_sectors,
                                                BlockDriverCompletionFunc *cb,
                                                void *opaque,
-                                               bool is_write,
-                                               CoroutineEntry *entry);
+                                               bool is_write);
 static void coroutine_fn bdrv_co_do_rw(void *opaque);
 
 static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
@@ -199,13 +192,8 @@ void path_combine(char *dest, int dest_size,
 
 void bdrv_register(BlockDriver *bdrv)
 {
-    if (bdrv->bdrv_co_readv) {
-        /* Emulate AIO by coroutines, and sync by AIO */
-        bdrv->bdrv_aio_readv = bdrv_co_aio_readv_em;
-        bdrv->bdrv_aio_writev = bdrv_co_aio_writev_em;
-        bdrv->bdrv_read = bdrv_read_em;
-        bdrv->bdrv_write = bdrv_write_em;
-     } else {
+    /* 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;
 
@@ -2382,7 +2370,7 @@ BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
     trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
 
     return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors,
-                                 cb, opaque, false, bdrv_co_do_rw);
+                                 cb, opaque, false);
 }
 
 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
@@ -2392,7 +2380,7 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
     trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
 
     return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors,
-                                 cb, opaque, true, bdrv_co_do_rw);
+                                 cb, opaque, true);
 }
 
 
@@ -2767,24 +2755,6 @@ static void bdrv_co_rw_bh(void *opaque)
     qemu_aio_release(acb);
 }
 
-/* Invoke .bdrv_co_readv/.bdrv_co_writev */
-static void coroutine_fn bdrv_co_rw(void *opaque)
-{
-    BlockDriverAIOCBCoroutine *acb = opaque;
-    BlockDriverState *bs = acb->common.bs;
-
-    if (!acb->is_write) {
-        acb->req.error = bs->drv->bdrv_co_readv(bs, acb->req.sector,
-            acb->req.nb_sectors, acb->req.qiov);
-    } else {
-        acb->req.error = bs->drv->bdrv_co_writev(bs, acb->req.sector,
-            acb->req.nb_sectors, acb->req.qiov);
-    }
-
-    acb->bh = qemu_bh_new(bdrv_co_rw_bh, acb);
-    qemu_bh_schedule(acb->bh);
-}
-
 /* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
 static void coroutine_fn bdrv_co_do_rw(void *opaque)
 {
@@ -2809,8 +2779,7 @@ static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
                                                int nb_sectors,
                                                BlockDriverCompletionFunc *cb,
                                                void *opaque,
-                                               bool is_write,
-                                               CoroutineEntry *entry)
+                                               bool is_write)
 {
     Coroutine *co;
     BlockDriverAIOCBCoroutine *acb;
@@ -2821,28 +2790,12 @@ static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
     acb->req.qiov = qiov;
     acb->is_write = is_write;
 
-    co = qemu_coroutine_create(entry);
+    co = qemu_coroutine_create(bdrv_co_do_rw);
     qemu_coroutine_enter(co, acb);
 
     return &acb->common;
 }
 
-static BlockDriverAIOCB *bdrv_co_aio_readv_em(BlockDriverState *bs,
-        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
-{
-    return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque,
-                                 false, bdrv_co_rw);
-}
-
-static BlockDriverAIOCB *bdrv_co_aio_writev_em(BlockDriverState *bs,
-        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
-{
-    return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque,
-                                 true, bdrv_co_rw);
-}
-
 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
         BlockDriverCompletionFunc *cb, void *opaque)
 {