block: take lock around bdrv_read implementations
This does the first part of the conversion to coroutines, by
wrapping bdrv_read implementations to take the mutex.
Drivers that implement bdrv_read rather than bdrv_co_readv can
then benefit from asynchronous operation (at least if the underlying
protocol supports it, which is not the case for raw-win32), even
though they still operate with a bounce buffer.
raw-win32 does not need the lock, because it cannot yield.
nbd also doesn't probably, but better be safe.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/bochs.c b/block/bochs.c
index b0f8072..ab7944d 100644
--- a/block/bochs.c
+++ b/block/bochs.c
@@ -209,6 +209,17 @@
return 0;
}
+static coroutine_fn int bochs_co_read(BlockDriverState *bs, int64_t sector_num,
+ uint8_t *buf, int nb_sectors)
+{
+ int ret;
+ BDRVBochsState *s = bs->opaque;
+ qemu_co_mutex_lock(&s->lock);
+ ret = bochs_read(bs, sector_num, buf, nb_sectors);
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+}
+
static void bochs_close(BlockDriverState *bs)
{
BDRVBochsState *s = bs->opaque;
@@ -220,7 +231,7 @@
.instance_size = sizeof(BDRVBochsState),
.bdrv_probe = bochs_probe,
.bdrv_open = bochs_open,
- .bdrv_read = bochs_read,
+ .bdrv_read = bochs_co_read,
.bdrv_close = bochs_close,
};
