Merge remote-tracking branch 'stefanha/block' into staging

* stefanha/block:
  sheepdog: pass oid directly to send_pending_req()
  sheepdog: don't update inode when create_and_write fails
  block/raw-win32: Fix compiler warnings (wrong format specifiers)
  qemu-img: report size overflow error message
  cutils: change strtosz_suffix_unit function
  virtio-blk: Return UNSUPP for unknown request types
  virtio-blk: add x-data-plane=on|off performance feature
  dataplane: add virtio-blk data plane code
  virtio-blk: restore VirtIOBlkConf->config_wce flag
  iov: add qemu_iovec_concat_iov()
  test-iov: add iov_discard_front/back() testcases
  iov: add iov_discard_front/back() to remove data
  dataplane: add Linux AIO request queue
  dataplane: add event loop
  dataplane: add virtqueue vring code
  dataplane: add host memory mapping code
  configure: add CONFIG_VIRTIO_BLK_DATA_PLANE
  raw-posix: add raw_get_aio_fd() for virtio-blk-data-plane

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/qemu/iov.h b/include/qemu/iov.h
index d06f8b9ce3..68d25f29b7 100644
--- a/include/qemu/iov.h
+++ b/include/qemu/iov.h
@@ -99,4 +99,17 @@ unsigned iov_copy(struct iovec *dst_iov, unsigned int dst_iov_cnt,
                  const struct iovec *iov, unsigned int iov_cnt,
                  size_t offset, size_t bytes);
 
+/*
+ * Remove a given number of bytes from the front or back of a vector.
+ * This may update iov and/or iov_cnt to exclude iovec elements that are
+ * no longer required.
+ *
+ * The number of bytes actually discarded is returned.  This number may be
+ * smaller than requested if the vector is too small.
+ */
+size_t iov_discard_front(struct iovec **iov, unsigned int *iov_cnt,
+                         size_t bytes);
+size_t iov_discard_back(struct iovec *iov, unsigned int *iov_cnt,
+                        size_t bytes);
+
 #endif