fcntl.2: BUGS: The O_SYNC and O_DSYNC flags are not modifiable using F_SETFL

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/fcntl.2

@@ -58,7 +58,7 @@
 .\" 2010-06-17, Michael Kerrisk
 .\"	Document F_SETPIPE_SZ and F_GETPIPE_SZ.
 .\"
-.TH FCNTL 2 2012-04-15 "Linux" "Linux Programmer's Manual"
+.TH FCNTL 2 2014-01-21 "Linux" "Linux Programmer's Manual"
 .SH NAME
 fcntl \- manipulate file descriptor
 .SH SYNOPSIS
@@ -185,9 +185,11 @@ On Linux this command can change only the
 and
 .B O_NONBLOCK
 flags.
-.\" FIXME . According to POSIX.1-2001, O_SYNC should also be modifiable
-.\" via fcntl(2), but currently Linux does not permit this
-.\" See http://bugzilla.kernel.org/show_bug.cgi?id=5994
+It is not possible to change the
+.BR O_DSYNC
+and
+.BR O_SYNC
+flags; see BUGS, below.
 .SS Advisory locking
 .BR F_GETLK ", " F_SETLK " and " F_SETLKW
 are used to acquire, release, and test for the existence of record
@@ -1237,6 +1239,18 @@ Clearly,
 alone is not going to be very useful if the process holding the lock
 may live on a different machine.
 .SH BUGS
+.SS F_SETFL
+It is not possible to use
+.BR F_SETFL
+to change the state of the
+.BR O_DYSNC
+and
+.BR O_SYNC
+flags.
+.\" FIXME . According to POSIX.1-2001, O_SYNC should also be modifiable
+.\" via fcntl(2), but currently Linux does not permit this
+.\" See http://bugzilla.kernel.org/show_bug.cgi?id=5994
+Attempts to change the state of these flags are silently ignored.
 .SS F_GETOWN
 A limitation of the Linux system call conventions on some
 architectures (notably i386) means that if a (negative)