Am 25.05.2016 um 00:25 hat Eric Blake geschrieben:
> Another step on our continuing quest to switch to byte-based
> interfaces.
>
> Kill an abuse of the comma operator while at it (fortunately,
> the semantics were still right).
>
> Signed-off-by: Eric Blake <ebl...@redhat.com>
> ---
> block/qed.c | 25 +++++++++++++------------
> 1 file changed, 13 insertions(+), 12 deletions(-)
>
> diff --git a/block/qed.c b/block/qed.c
> index 0ab5b40..a0be886 100644
> --- a/block/qed.c
> +++ b/block/qed.c
> @@ -1419,7 +1419,7 @@ typedef struct {
> bool done;
> } QEDWriteZeroesCB;
>
> -static void coroutine_fn qed_co_write_zeroes_cb(void *opaque, int ret)
> +static void coroutine_fn qed_co_pwrite_zeroes_cb(void *opaque, int ret)
> {
> QEDWriteZeroesCB *cb = opaque;
>
> @@ -1430,10 +1430,10 @@ static void coroutine_fn qed_co_write_zeroes_cb(void
> *opaque, int ret)
> }
> }
>
> -static int coroutine_fn bdrv_qed_co_write_zeroes(BlockDriverState *bs,
> - int64_t sector_num,
> - int nb_sectors,
> - BdrvRequestFlags flags)
> +static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
> + int64_t offset,
> + int count,
> + BdrvRequestFlags flags)
> {
> BlockAIOCB *blockacb;
> BDRVQEDState *s = bs->opaque;
> @@ -1443,10 +1443,10 @@ static int coroutine_fn
> bdrv_qed_co_write_zeroes(BlockDriverState *bs,
>
> /* Refuse if there are untouched backing file sectors */
> if (bs->backing) {
> - if (qed_offset_into_cluster(s, sector_num * BDRV_SECTOR_SIZE) != 0) {
> + if (qed_offset_into_cluster(s, offset) != 0) {
> return -ENOTSUP;
> }
> - if (qed_offset_into_cluster(s, nb_sectors * BDRV_SECTOR_SIZE) != 0) {
> + if (qed_offset_into_cluster(s, count) != 0) {
> return -ENOTSUP;
> }
> }
Unaligned requests are only emulated if there is no backing file...
> @@ -1454,12 +1454,13 @@ static int coroutine_fn
> bdrv_qed_co_write_zeroes(BlockDriverState *bs,
> /* Zero writes start without an I/O buffer. If a buffer becomes
> necessary
> * then it will be allocated during request processing.
> */
> - iov.iov_base = NULL,
> - iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE,
> + iov.iov_base = NULL;
> + iov.iov_len = count;
>
> qemu_iovec_init_external(&qiov, &iov, 1);
> - blockacb = qed_aio_setup(bs, sector_num, &qiov, nb_sectors,
> - qed_co_write_zeroes_cb, &cb,
> + blockacb = qed_aio_setup(bs, offset >> BDRV_SECTOR_BITS, &qiov,
> + count >> BDRV_SECTOR_BITS,
...so offset and count can still be unaligned here and we end up zeroing
out the wrong part of the sector. I guess we need to return -ENOTSUP for
all sub-sector requests, even without a backing file.
> + qed_co_pwrite_zeroes_cb, &cb,
> QED_AIOCB_WRITE | QED_AIOCB_ZERO);
> if (!blockacb) {
> return -EIO;
Kevin
