From 2914caa088e3fbbdbfd73106af0cae49af1d472e Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 20 Oct 2011 13:16:22 +0200 Subject: 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 Signed-off-by: Kevin Wolf --- block/cow.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'block/cow.c') diff --git a/block/cow.c b/block/cow.c index 2f426e7427..a5fcd20817 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, -- cgit v1.2.3