allow qemu_iovec_from_buffer() to specify offset from which to start copying
Similar to
qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
int c, size_t bytes);
the new prototype is:
qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,
const void *buf, size_t bytes);
The processing starts at offset bytes within qiov.
This way, we may copy a bounce buffer directly to
a middle of qiov.
This is exactly the same function as iov_from_buf() from
iov.c, so use the existing implementation and rename it
to qemu_iovec_from_buf() to be shorter and to match the
utility function.
As with utility implementation, we now assert that the
offset is inside actual iovec. Nothing changed for
current callers, because `offset' parameter is new.
While at it, stop using "bounce-qiov" in block/qcow2.c
and copy decrypted data directly from cluster_data
instead of recreating a temp qiov for doing that.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/block.c b/block.c
index 7547051..e0ef95e 100644
--- a/block.c
+++ b/block.c
@@ -1821,8 +1821,8 @@
}
skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
- qemu_iovec_from_buffer(qiov, bounce_buffer + skip_bytes,
- nb_sectors * BDRV_SECTOR_SIZE);
+ qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,
+ nb_sectors * BDRV_SECTOR_SIZE);
err:
qemu_vfree(bounce_buffer);
@@ -3382,7 +3382,7 @@
BlockDriverAIOCBSync *acb = opaque;
if (!acb->is_write)
- qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
+ qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
qemu_vfree(acb->bounce);
acb->common.cb(acb->common.opaque, acb->ret);
qemu_bh_delete(acb->bh);
