158 lines
2.5 KiB
HTML
158 lines
2.5 KiB
HTML
<HTML
|
|
><HEAD
|
|
><TITLE
|
|
>dxferp</TITLE
|
|
><META
|
|
NAME="GENERATOR"
|
|
CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
|
|
"><LINK
|
|
REL="HOME"
|
|
TITLE="The Linux SCSI Generic (sg) HOWTO"
|
|
HREF="index.html"><LINK
|
|
REL="UP"
|
|
TITLE="The sg_io_hdr_t structure in detail"
|
|
HREF="sg_io_hdr_t.html"><LINK
|
|
REL="PREVIOUS"
|
|
TITLE="dxfer_len"
|
|
HREF="x198.html"><LINK
|
|
REL="NEXT"
|
|
TITLE="cmdp"
|
|
HREF="x209.html"></HEAD
|
|
><BODY
|
|
CLASS="SECT1"
|
|
BGCOLOR="#FFFFFF"
|
|
TEXT="#000000"
|
|
LINK="#0000FF"
|
|
VLINK="#840084"
|
|
ALINK="#0000FF"
|
|
><DIV
|
|
CLASS="NAVHEADER"
|
|
><TABLE
|
|
SUMMARY="Header navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TH
|
|
COLSPAN="3"
|
|
ALIGN="center"
|
|
>The Linux SCSI Generic (sg) HOWTO</TH
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="left"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="x198.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="80%"
|
|
ALIGN="center"
|
|
VALIGN="bottom"
|
|
>Chapter 6. The sg_io_hdr_t structure in detail</TD
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="right"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="x209.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
></TABLE
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"></DIV
|
|
><DIV
|
|
CLASS="SECT1"
|
|
><H1
|
|
CLASS="SECT1"
|
|
><A
|
|
NAME="AEN204">6.7. dxferp</H1
|
|
><P
|
|
> If 'iovec_count' is zero then this value is a pointer to user memory
|
|
of at least 'dxfer_len' bytes in length. If there is a data transfer
|
|
associated with the command then the data will be transferred to or
|
|
from this user memory.
|
|
If 'iovec_count' is greater than zero then this value points to a
|
|
scatter-gather array in user memory. Each element of this array
|
|
should be an object of type sg_iovec_t.
|
|
Note that data is sometimes written to user memory (e.g. from a failed
|
|
SCSI READ) even when an error has occurred.</P
|
|
><P
|
|
>If mmap-ed IO is selected then the value in 'dxferp' is ignored and any
|
|
data transfers will be to and from the address returned by the prior
|
|
mmap() call.</P
|
|
><P
|
|
>The type of dxferp is void * .</P
|
|
></DIV
|
|
><DIV
|
|
CLASS="NAVFOOTER"
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"><TABLE
|
|
SUMMARY="Footer navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="x198.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="index.html"
|
|
ACCESSKEY="H"
|
|
>Home</A
|
|
></TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="x209.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
>dxfer_len</TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="sg_io_hdr_t.html"
|
|
ACCESSKEY="U"
|
|
>Up</A
|
|
></TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
>cmdp</TD
|
|
></TR
|
|
></TABLE
|
|
></DIV
|
|
></BODY
|
|
></HTML
|
|
> |