1 files changed, 18 insertions, 3 deletions
diff --git a/usr/src/man/man2/open.2 b/usr/src/man/man2/open.2
index 86e00e575a..0e13f5af79 100644
--- a/usr/src/man/man2/open.2
+++ b/usr/src/man/man2/open.2
@@ -46,8 +46,9 @@
 .\" Portions Copyright (c) 2013, OmniTI Computer Consulting, Inc.
 .\" All Rights Reserved.
 .\" Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
+.\" Copyright 2020 Joyent, Inc.
 .\"
-.TH OPEN 2 "Jan 20, 2020"
+.TH OPEN 2 "Mar 10, 2020"
 .SH NAME
 open, openat \- open a file
 .SH SYNOPSIS
@@ -176,6 +177,19 @@ whether the file is open for reading, writing or for both.
 .sp
 .ne 2
 .na
+.B O_DIRECT
+.ad
+.sp .6
+.RS 4n
+Indicates that the file data is not going to be reused in the near future.
+When possible, data is read or written directly between the application's
+memory and the device when the data is accessed with \fBread\fR(2) and
+\fBwrite\fR(2) operations. See \fBdirectio\fR(3C) for more details.
+.RE
+
+.sp
+.ne 2
+.na
 .B O_DIRECTORY
 .ad
 .sp .6
@@ -619,7 +633,7 @@ The \fIpath\fR argument points to an illegal address.
 \fB\fBEINVAL\fR\fR
 .ad
 .RS 16n
-The system does not support synchronized I/O for this file, or the
+The system does not support synchronized or direct I/O for this file, or the
 \fBO_XATTR\fR flag was supplied and the underlying file system does not support
 extended file attributes.
 .RE
@@ -1018,7 +1032,8 @@ Standard	For \fBopen()\fR, see \fBstandards\fR(5).
 \fBIntro\fR(2), \fBchmod\fR(2), \fBclose\fR(2), \fBcreat\fR(2), \fBdup\fR(2),
 \fBexec\fR(2), \fBfcntl\fR(2), \fBgetmsg\fR(2), \fBgetrlimit\fR(2),
 \fBlseek\fR(2), \fBputmsg\fR(2), \fBread\fR(2), \fBstat\fR(2), \fBumask\fR(2),
-\fBwrite\fR(2), \fBattropen\fR(3C), \fBfcntl.h\fR(3HEAD), \fBstat.h\fR(3HEAD),
+\fBwrite\fR(2), \fBattropen\fR(3C), \fBdirectio\fR(3C),
+\fBfcntl.h\fR(3HEAD), \fBstat.h\fR(3HEAD),
 \fBunlockpt\fR(3C), \fBattributes\fR(5), \fBlf64\fR(5), \fBprivileges\fR(5),
 \fBstandards\fR(5), \fBconnld\fR(7M), \fBstreamio\fR(7I)
 .SH NOTES