linux.git/fs/file.c, branch v3.7-rc2

dup3: Return an error when oldfd == newfd.

2012-10-10T03:33:38+00:00

I have tested the attached patch to fix the dup3 regression.

Rich.

From 0944e30e12dec6544b3602626b60ff412375c78f Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" 
Date: Tue, 9 Oct 2012 14:42:45 +0100
Subject: [PATCH] dup3: Return an error when oldfd == newfd.

The following commit:

  commit fe17f22d7fd0e344ef6447238f799bb49f670c6f
  Author: Al Viro 
  Date:   Tue Aug 21 11:48:11 2012 -0400

    take purely descriptor-related stuff from fcntl.c to file.c

was supposed to be just code motion, but it dropped the following two
lines:

  if (unlikely(oldfd == newfd))
          return -EINVAL;

from the dup3 system call.  dup3 is not specified by POSIX, so Linux
can do what it likes.  However the POSIX proposal for dup3 [1] states
that it should return an error if oldfd == newfd.

[1] http://austingroupbugs.net/view.php?id=411

Signed-off-by: Richard W.M. Jones 
Tested-by: Richard W.M. Jones 
Signed-off-by: Al Viro

export fget_light

2012-09-27T01:10:06+00:00

Signed-off-by: Al Viro

new helper: daemonize_descriptors()

2012-09-27T01:10:00+00:00

descriptor-related parts of daemonize, done right.  As the
result we simplify the locking rules for ->files - we
hold task_lock in *all* cases when we modify ->files.

Signed-off-by: Al Viro

new helper: iterate_fd()

2012-09-27T01:09:59+00:00

iterates through the opened files in given descriptor table,
calling a supplied function; we stop once non-zero is returned.
Callback gets struct file *, descriptor number and const void *
argument passed to iterator.  It is called with files->file_lock
held, so it is not allowed to block.

tty_io, netprio_cgroup and selinux flush_unauthorized_files()
converted to its use.

Signed-off-by: Al Viro

make expand_files() and alloc_fd() static

2012-09-27T01:09:58+00:00

no callers outside of fs/file.c left

Signed-off-by: Al Viro

take __{set,clear}_{open_fd,close_on_exec}() into fs/file.c

2012-09-27T01:09:58+00:00

nobody uses those outside anymore.

Signed-off-by: Al Viro

new helper: replace_fd()

2012-09-27T01:09:57+00:00

analog of dup2(), except that it takes struct file * as source.

Signed-off-by: Al Viro

take purely descriptor-related stuff from fcntl.c to file.c

2012-09-27T01:09:57+00:00

Signed-off-by: Al Viro

take close-on-exec logics to fs/file.c, clean it up a bit

2012-09-27T01:09:56+00:00

... and add cond_resched() there, while we are at it.  We can
get large latencies as is...

Signed-off-by: Al Viro

take descriptor-related part of close() to file.c

2012-09-27T01:08:56+00:00

Signed-off-by: Al Viro