[PATCH 1/4] iov: Update parameter usage in iov_(to|from)_buf()

Hannes Reinecke
2011-07-11T13:03:13Z

iov_to_buf() has an 'offset' parameter, iov_from_buf() hasn't.
This patch adds the missing parameter to iov_from_buf().
It also renames the 'offset' parameter to 'iov_off' to
emphasize it's the offset into the iovec and not the buffer.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Alexander Graf <agraf@suse.de>
---
hw/virtio-net.c | 2 +-
hw/virtio-serial-bus.c | 2 +-
iov.c | 49 ++++++++++++++++++++++++++---------------------
iov.h | 10 ++++----
4 files changed, 34 insertions(+), 29 deletions(-)

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 6997e02..a32cc01 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -657,7 +657,7 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_

/* copy in packet. ugh */
len = iov_from_buf(sg, elem.in_num,
- buf + offset, size - offset);
+ buf + offset, 0, size - offset);
total += len;
offset += len;
/* If buffers can't be merged, at this point we
diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index 7f6db7b..53c58d0 100644
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -103,7 +103,7 @@ static size_t write_to_port(VirtIOSerialPort *port,
}

len = iov_from_buf(elem.in_sg, elem.in_num,
- buf + offset, size - offset);
+ buf + offset, 0, size - offset);
offset += len;

virtqueue_push(vq, &elem, len);
diff --git a/iov.c b/iov.c
index 588cd04..1e02791 100644
--- a/iov.c
+++ b/iov.c
@@ -14,56 +14,61 @@

#include "iov.h"

-size_t iov_from_buf(struct iovec *iov, unsigned int iovcnt,
- const void *buf, size_t size)
+size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt,
+ const void *buf, size_t iov_off, size_t size)
{
- size_t offset;
+ size_t iovec_off, buf_off;
unsigned int i;

- offset = 0;
- for (i = 0; offset < size && i < iovcnt; i++) {
- size_t len;
+ iovec_off = 0;
+ buf_off = 0;
+ for (i = 0; i < iov_cnt && size; i++) {
+ if (iov_off < (iovec_off + iov[i].iov_len)) {
+ size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off, size);

- len = MIN(iov[i].iov_len, size - offset);
+ memcpy(iov[i].iov_base + (iov_off - iovec_off), buf + buf_off, len);

- memcpy(iov[i].iov_base, buf + offset, len);
- offset += len;
+ buf_off += len;
+ iov_off += len;
+ size -= len;
+ }
+ iovec_off += iov[i].iov_len;
}
- return offset;
+ return buf_off;
}

-size_t iov_to_buf(const struct iovec *iov, const unsigned int iovcnt,
- void *buf, size_t offset, size_t size)
+size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt,
+ void *buf, size_t iov_off, size_t size)
{
uint8_t *ptr;
- size_t iov_off, buf_off;
+ size_t iovec_off, buf_off;
unsigned int i;

ptr = buf;
- iov_off = 0;
+ iovec_off = 0;
buf_off = 0;
- for (i = 0; i < iovcnt && size; i++) {
- if (offset < (iov_off + iov[i].iov_len)) {
- size_t len = MIN((iov_off + iov[i].iov_len) - offset , size);
+ for (i = 0; i < iov_cnt && size; i++) {
+ if (iov_off < (iovec_off + iov[i].iov_len)) {
+ size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size);

- memcpy(ptr + buf_off, iov[i].iov_base + (offset - iov_off), len);
+ memcpy(ptr + buf_off, iov[i].iov_base + (iov_off - iovec_off), len);

buf_off += len;
- offset += len;
+ iov_off += len;
size -= len;
}
- iov_off += iov[i].iov_len;
+ iovec_off += iov[i].iov_len;
}
return buf_off;
}

-size_t iov_size(const struct iovec *iov, const unsigned int iovcnt)
+size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt)
{
size_t len;
unsigned int i;

len = 0;
- for (i = 0; i < iovcnt; i++) {
+ for (i = 0; i < iov_cnt; i++) {
len += iov[i].iov_len;
}
return len;
diff --git a/iov.h b/iov.h
index 60a8547..110f67a 100644
--- a/iov.h
+++ b/iov.h
@@ -12,8 +12,8 @@

#include "qemu-common.h"

-size_t iov_from_buf(struct iovec *iov, unsigned int iovcnt,
- const void *buf, size_t size);
-size_t iov_to_buf(const struct iovec *iov, const unsigned int iovcnt,
- void *buf, size_t offset, size_t size);
-size_t iov_size(const struct iovec *iov, const unsigned int iovcnt);
+size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt,
+ const void *buf, size_t iov_off, size_t size);
+size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt,
+ void *buf, size_t iov_off, size_t size);
+size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt);
--
1.7.3.4