diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2011-10-20 13:16:22 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2011-10-21 17:34:14 +0200 |
| commit | 2914caa088e3fbbdbfd73106af0cae49af1d472e (patch) | |
| tree | 07d3de39e3839400dd903e53c3a86e5224c58def /block/cow.c | |
| parent | 848c66e8f5b631961580f7f010a5831430dc84c2 (diff) | |
| download | qemu-2914caa088e3fbbdbfd73106af0cae49af1d472e.zip qemu-2914caa088e3fbbdbfd73106af0cae49af1d472e.tar.gz qemu-2914caa088e3fbbdbfd73106af0cae49af1d472e.tar.bz2 | |
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.c | 13 |
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, |