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authorPaolo Bonzini <pbonzini@redhat.com>2011-10-20 13:16:22 +0200
committerKevin Wolf <kwolf@redhat.com>2011-10-21 17:34:14 +0200
commit2914caa088e3fbbdbfd73106af0cae49af1d472e (patch)
tree07d3de39e3839400dd903e53c3a86e5224c58def /block/cow.c
parent848c66e8f5b631961580f7f010a5831430dc84c2 (diff)
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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>
Diffstat (limited to 'block/cow.c')
-rw-r--r--block/cow.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/block/cow.c b/block/cow.c
index 2f426e7..a5fcd20 100644
--- a/block/cow.c
+++ b/block/cow.c
@@ -201,6 +201,17 @@ static int cow_read(BlockDriverState *bs, int64_t sector_num,
return 0;
}
+static coroutine_fn int cow_co_read(BlockDriverState *bs, int64_t sector_num,
+ uint8_t *buf, int nb_sectors)
+{
+ int ret;
+ BDRVCowState *s = bs->opaque;
+ qemu_co_mutex_lock(&s->lock);
+ ret = cow_read(bs, sector_num, buf, nb_sectors);
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+}
+
static int cow_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
@@ -308,7 +319,7 @@ static BlockDriver bdrv_cow = {
.instance_size = sizeof(BDRVCowState),
.bdrv_probe = cow_probe,
.bdrv_open = cow_open,
- .bdrv_read = cow_read,
+ .bdrv_read = cow_co_read,
.bdrv_write = cow_write,
.bdrv_close = cow_close,
.bdrv_create = cow_create,