[RFC v1] man/man2/close.2: CAVEATS: Document divergence from POSIX.1-2024

[Alejandro Colomar <alx@kernel.org>]

POSIX.1-2024 now mandates a behavior different from what Linux (and many
other implementations) does.  It requires that we report EINPROGRESS for
what now is EINTR.

There are no plans to conform to POSIX.1-2024 within the Linux kernel,
so document this divergence.  Keep POSIX.1-2008 as the standard to
which we conform in STANDARDS.

Link: <https://sourceware.org/bugzilla/show_bug.cgi?id=14627>
Link: <https://pubs.opengroup.org/onlinepubs/9799919799/functions/close.html>
Cc: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: <linux-api@vger.kernel.org>
Cc: <libc-alpha@sourceware.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---

Hi,

I've prepared this draft for discussion.  While doing so, I've noticed
the glibc bug ticket, which sounds possibly reasonable: returning 0
instead of reporting an error on EINTR.  That would be an option that
would make us conforming to POSIX.1-2024.  And given that a user can
(and must) do nothing after seeing EINTR, returning 0 wouldn't change
things.

So, I'll leave this patch open for discussion.


Have a lovely day!
Alex

 man/man2/close.2 | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/man/man2/close.2 b/man/man2/close.2
index b25ea4de9..9d5e26eed 100644
--- a/man/man2/close.2
+++ b/man/man2/close.2
@@ -191,10 +191,7 @@ .SS Dealing with error returns from close()
 meaning that the file descriptor was invalid)
 even if they subsequently report an error on return from
 .BR close ().
-POSIX.1 is currently silent on this point,
-but there are plans to mandate this behavior in the next major release
-.\" Issue 8
-of the standard.
+POSIX.1-2008 was silent on this point.
 .P
 A careful programmer who wants to know about I/O errors may precede
 .BR close ()
@@ -206,7 +203,7 @@ .SS Dealing with error returns from close()
 error is a somewhat special case.
 Regarding the
 .B EINTR
-error, POSIX.1-2008 says:
+error, POSIX.1-2008 said:
 .P
 .RS
 If
@@ -243,16 +240,10 @@ .SS Dealing with error returns from close()
 error, and on at least one,
 .BR close ()
 must be called again.
-There are plans to address this conundrum for
-the next major release of the POSIX.1 standard.
-.\" FIXME . for later review when Issue 8 is one day released...
-.\" POSIX proposes further changes for EINTR
-.\" http://austingroupbugs.net/tag_view_page.php?tag_id=8
-.\" http://austingroupbugs.net/view.php?id=529
-.\"
-.\" FIXME .
-.\" Review the following glibc bug later
-.\" https://sourceware.org/bugzilla/show_bug.cgi?id=14627
+.P
+POSIX.1-2024 standardized the behavior of HP-UX,
+making Linux and many other implementations non-conforming.
+There are no plans to change the behavior on Linux.
 .SH SEE ALSO
 .BR close_range (2),
 .BR fcntl (2),

Range-diff against v0:
-:  --------- > 1:  efaffc5a4 man/man2/close.2: CAVEATS: Document divergence from POSIX.1-2024

base-commit: 978b017d93e4e32b752b33877e44a8365644630c
-- 
2.49.0