block: Make bdrv_pread() a bdrv_prwv_co() wrapper

Instead of implementing the alignment adjustment here, use the now
existing functionality of bdrv_co_do_preadv().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2013-12-05 12:29:59 +01:00
parent 775aa8b6e0
commit a3ef657185

47
block.c
View File

@ -2721,49 +2721,26 @@ int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
} }
} }
int bdrv_pread(BlockDriverState *bs, int64_t offset, int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
void *buf, int count1)
{ {
uint8_t tmp_buf[BDRV_SECTOR_SIZE]; QEMUIOVector qiov;
int len, nb_sectors, count; struct iovec iov = {
int64_t sector_num; .iov_base = (void *)buf,
.iov_len = bytes,
};
int ret; int ret;
count = count1; if (bytes < 0) {
/* first read to align to sector start */ return -EINVAL;
len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
if (len > count)
len = count;
sector_num = offset >> BDRV_SECTOR_BITS;
if (len > 0) {
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
return ret;
memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
count -= len;
if (count == 0)
return count1;
sector_num++;
buf += len;
} }
/* read the sectors "in place" */ qemu_iovec_init_external(&qiov, &iov, 1);
nb_sectors = count >> BDRV_SECTOR_BITS; ret = bdrv_prwv_co(bs, offset, &qiov, false, 0);
if (nb_sectors > 0) { if (ret < 0) {
if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
return ret; return ret;
sector_num += nb_sectors;
len = nb_sectors << BDRV_SECTOR_BITS;
buf += len;
count -= len;
} }
/* add data from the last sector */ return bytes;
if (count > 0) {
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
return ret;
memcpy(buf, tmp_buf, count);
}
return count1;
} }
int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov) int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)