lio_listio(2): Allow LIO_READV and LIO_WRITEV.

Allow multiple vector IOs to be started with one system call.
aio_readv() and aio_writev() already used these opcodes under the
covers.  This commit makes them available to user space.

Being non-standard extensions, they're only visible if __BSD_VISIBLE is
defined, like the functions.

Reviewed by:    asomers, kib
MFC after:      2 weeks
Differential Revision:  https://reviews.freebsd.org/D31627

1 files changed, 15 insertions, 1 deletions

diff --git a/lib/libc/sys/lio_listio.2 b/lib/libc/sys/lio_listio.2
index 0e04e7c88338..ef1b1add3376 100644
--- a/lib/libc/sys/lio_listio.2
+++ b/lib/libc/sys/lio_listio.2
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd December 7, 2019
+.Dd August 22, 2021
 .Dt LIO_LISTIO 2
 .Os
 .Sh NAME
@@ -66,11 +66,17 @@ The following operations are supported:
 .It Dv LIO_READ
 Read data as if by a call to
 .Xr aio_read 2 .
+.It Dv LIO_READV
+Read data as if by a call to
+.Xr aio_readv 2 .
 .It Dv LIO_NOP
 No operation.
 .It Dv LIO_WRITE
 Write data as if by a call to
 .Xr aio_write 2 .
+.It Dv LIO_WRITEV
+Write data as if by a call to
+.Xr aio_writev 2 .
 .El
 .Pp
 If the
@@ -205,7 +211,9 @@ structure individually by calling
 .Sh SEE ALSO
 .Xr aio_error 2 ,
 .Xr aio_read 2 ,
+.Xr aio_readv 2 ,
 .Xr aio_write 2 ,
+.Xr aio_writev 2 ,
 .Xr read 2 ,
 .Xr write 2 ,
 .Xr sigevent 3 ,
@@ -216,6 +224,12 @@ The
 .Fn lio_listio
 function is expected to conform to
 .St -p1003.1-2001 .
+The
+.Dv LIO_READV
+and
+.Dv LIO_WRITEV
+operations are
+.Fx extensions, and should not be used in portable code.
 .Sh HISTORY
 The
 .Fn lio_listio