block: Introduce bdrv_preadv()

We already have a byte-based bdrv_pwritev(), but the read counterpart
was still missing. This commit adds it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Kevin Wolf 2016-06-09 16:36:00 +02:00
parent 48bea96572
commit f1e8474115
2 changed files with 14 additions and 7 deletions

View File

@ -700,6 +700,18 @@ int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
} }
} }
int bdrv_preadv(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
{
int ret;
ret = bdrv_prwv_co(bs, offset, qiov, false, 0);
if (ret < 0) {
return ret;
}
return qiov->size;
}
int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes) int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
{ {
QEMUIOVector qiov; QEMUIOVector qiov;
@ -707,19 +719,13 @@ int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
.iov_base = (void *)buf, .iov_base = (void *)buf,
.iov_len = bytes, .iov_len = bytes,
}; };
int ret;
if (bytes < 0) { if (bytes < 0) {
return -EINVAL; return -EINVAL;
} }
qemu_iovec_init_external(&qiov, &iov, 1); qemu_iovec_init_external(&qiov, &iov, 1);
ret = bdrv_prwv_co(bs, offset, &qiov, false, 0); return bdrv_preadv(bs, offset, &qiov);
if (ret < 0) {
return ret;
}
return bytes;
} }
int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov) int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)

View File

@ -235,6 +235,7 @@ int bdrv_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags); 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 count); void *buf, int count);
int bdrv_preadv(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
int bdrv_pwrite(BlockDriverState *bs, int64_t offset, int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
const void *buf, int count); const void *buf, int count);
int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov); int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);