On 04/28/2016 07:16 AM, Kevin Wolf wrote: > Signed-off-by: Kevin Wolf <kw...@redhat.com> > --- > block/bochs.c | 51 +++++++++++++++++++++++++++++++++------------------ > 1 file changed, 33 insertions(+), 18 deletions(-) >
> + uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
> + int nb_sectors = bytes >> BDRV_SECTOR_BITS;
Since we're using the named constant here (instead of /512 or >>9),...
> + uint64_t bytes_done = 0;
> + QEMUIOVector local_qiov;
> int ret;
>
> + assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
> + assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
> +
> + qemu_iovec_init(&local_qiov, qiov->niov);
> + qemu_co_mutex_lock(&s->lock);
> +
> while (nb_sectors > 0) {
> int64_t block_offset = seek_to_sector(bs, sector_num);
> if (block_offset < 0) {
> - return block_offset;
> - } else if (block_offset > 0) {
> - ret = bdrv_pread(bs->file->bs, block_offset, buf, 512);
> + ret = block_offset;
> + goto fail;
> + }
> +
> + qemu_iovec_reset(&local_qiov);
> + qemu_iovec_concat(&local_qiov, qiov, bytes_done, 512);
should we also use the named constant BDRV_SECTOR_SIZE here instead of 512?
I don't care strongly enough for a respin, though, particularly since it
would affect line wrapping.
Reviewed-by: Eric Blake <ebl...@redhat.com>
> +
> + if (block_offset > 0) {
> + ret = bdrv_co_preadv(bs->file->bs, block_offset, 512,
> + &local_qiov, 0);
> if (ret < 0) {
> - return ret;
> + goto fail;
> }
> } else {
> - memset(buf, 0, 512);
> + qemu_iovec_memset(&local_qiov, 0, 0, 512);
> }
> nb_sectors--;
> sector_num++;
> - buf += 512;
> + bytes_done += 512;
More of the magic 512, if you care.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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