Re: [Qemu-devel] [PATCH 4/7] block: make discard asynchronous

[Stefan Hajnoczi]

On Mon, Jan 14, 2013 at 04:26:55PM +0100, Paolo Bonzini wrote:
> +static ssize_t handle_aiocb_discard(RawPosixAIOData *aiocb)
> +{
> +    int ret = -EOPNOTSUPP;
> +    BDRVRawState *s = aiocb->bs->opaque;
> +
> +    if (s->has_discard == 0) {
> +        return 0;
> +    }
> +
> +    if (aiocb->aio_type & QEMU_AIO_BLKDEV) {
> +#ifdef BLKDISCARD
> +        do {
> +            uint64_t range[2] = { aiocb->aio_offset, aiocb->aio_nbytes };
> +            if (ioctl(aiocb->aio_fildes, BLKDISCARD, range) == 0) {
> +                return 0;
> +            }
> +        } while (errno == EINTR);
> +
> +        ret = -errno;
> +#endif
> +    } else {
> +#ifdef CONFIG_XFS
> +        if (s->is_xfs) {
> +            return xfs_discard(s, aiocb->aio_offset, aiocb->aio_nbytes);
> +        }
> +#endif
> +
> +#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
> +        do {
> +            if (fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
> +                          aiocb->aio_offset, aiocb->aio_nbytes) == 0) {

It is cleaner to use either aiocb->aio_fildes or s->fd consistently in
this function.  Minor issue, not worth respinning for.

Stefan