Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC 268531,269079,269204:
Fix various edge cases with rewinddir(), seekdir(), and telldir():
- In the unionfs case, opendir() and fdopendir() read the directory's full
contents and cache it. This cache is not refreshed when rewinddir() is
called, so rewinddir() will not notice updates to a directory. Fix this
by splitting the code to fetch a directory's contents out of
__opendir_common() into a new _filldir() function and call this from
rewinddir() when operating on a unionfs directory.
- If rewinddir() is called on a directory opened with fdopendir() before
any directory entries are fetched, rewinddir() will not adjust the seek
location of the backing file descriptor. If the file descriptor passed
to fdopendir() had a non-zero offset, the rewinddir() will not rewind to
the beginning. Fix this by always seeking back to 0 in rewinddir().
This means the dd_rewind hack can also be removed.
- Add missing locking to rewinddir()
- POSIX says that passing a location returned by telldir() to seekdir()
after an intervening call to rewinddir() is undefined, so reclaim any
pending telldir() cookies in the directory when rewinddir() is called.
- If telldir() is called immediately after a call to seekdir(), POSIX
requires the return value of telldir() to equal the value passed to
seekdir(). The current seekdir code with SINGLEUSE enabled breaks
this case as each call to telldir() allocates a new cookie. Instead,
remove the SINGLEUSE code and change telldir() to look for an existing
cookie for the directory's current location rather than always creating
a new cookie.

PR: 121656

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Implement fdclosedir(3) function, which is equivalent to the closedir(3)
function, but returns directory file descriptor instead of closing it.

Submitted by: Mariusz Zaborski <oshogbo@FreeBSD.org>
Sponsored by: Google Summer of Code 2013

Hide DIR definition by making it an opaque struct typedef.

Introduce dirfd() libc exported symbol replacing macro with same name,
preserve _dirfd() macro for internal use.

Replace dirp->dd_fd with dirfd() call. Avoid using dirfd as variable
name to prevent shadowing global symbol.

Sponsored by: Google Summer Of Code 2011

Remove the Berkeley clause 3's.
Add a few $FreeBSD$

Move scandir(3) and alphasort(3) into XSI namespace.

Noted and reviewed by: bde
MFC after: 2 weeks

Modernize scandir(3) and alphasort(3) interfaces according to the IEEE
Std 1003.1-2008. Both Linux and Solaris conforms to the new definitions,
so we better follow too (older glibc used old BSDish alphasort prototype
and corresponding type of the comparision function for scandir). While
there, change the definitions of the functions to ANSI C and fix several
style issues nearby.

Remove requirement for "sys/types.h" include for functions from manpage.

POSIX also requires that alphasort(3) sorts as if strcoll(3) was used,
but leave the strcmp(3) call in the function for now.

Adapt in-tree callers of scandir(3) to new declaration. The fact that
select_sections() from catman(1) could modify supplied struct dirent is
a bug.

PR: standards/142255
MFC after: 2 weeks

Implement fdopendir(3) by splitting __opendir2() into two parts, the upper part
deals with the usual __opendir2() calls, and the rest part with an interface
translator to expose fdopendir(3) functionality. Manual page was obtained from
kib@'s work for *at(2) system calls.

Use a forward definition of an opaque structure rather than a void
to avoid a strict alias type check failure in gcc 4.2.

Change the definition of NULL on ia64 (for LP64 compilations) from
an int constant to a long constant. This change improves consistency
in the following two ways:
1. The first 8 arguments are always passed in registers on ia64, which
by virtue of the generated code implicitly widens ints to longs and
allows the use of an 32-bit integral type for 64-bit arguments.
Subsequent arguments are passed onto the memory stack, which does
not exhibit the same behaviour and consequently do not allow this.
In practice this means that variadic functions taking pointers
and given NULL (without cast) work as long as the NULL is passed
in one of the first 8 arguments. A SIGSEGV is more likely the
result if such would be done for stack-based arguments. This is
due to the fact that the upper 4 bytes remain undefined.
2. All 64-bit platforms that FreeBSD supports, with the obvious
exception of ia64, allow 32-bit integral types (specifically NULL)
when 64-bit pointers are expected in variadic functions by way of
how the compiler generates code. As such, code that works correctly
(whether rightfully so or not) on any platform other than ia64, may
fail on ia64.

To more easily allow tweaking of the definition of NULL, this commit
removes the 12 definitions in the various headers and puts it in a
new header that can be included whenever NULL is to be made visible.

This commit fixes GNOME, emacs, xemacs and a whole bunch of ports
that I don't particularly care about at this time...

Fix namespace issues by using the relatively new visibility
primitives.

style(9): line up function names.

Breath deep and take __P out of the system include files.

# This appears to not break X11, but I'm having problems compiling the
# glide part of the server with or without this patch, so I can't tell
# for sure.

Add a lock to DIR to make telldir and friends MT-safe.

Clean up stdio.h a bit and remove _THREAD_SAFE. Some of the
usual macros getc, putc, getchar, putchar are no longer macros.

Approved by: -arch

Move telldir position recording type definitions and prototypes
to "telldir.h" in order to prevent namespace pollution in
<dirent.h> (which was including <sys/queue.h>).

Add $FreeBSD$ to rewinddir.c and seekdir.c.

Add a LIST_HEAD to DIR for a queue of telldir positions.
Also add a location count (used as the magic for telldir)
to DIR. A future change will also add a mutex/lock.

Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.

Fixed missing declaration of getdents(2).

style fixes, remove extra braces.

readdir_r is not POSIX according to POSIX_SOURCE, bruce says:
> readdir_r() is in the _POSIX_SOURCE section, but is not a POSIX.1-1990
> function. It's POSIX.1-1996 so it should be under a different feature
> test which we don't support yet.

make sure errno is saved so that its contents are cleared unless
necessary.

Submitted by: bde

add pthread_cancel, obtained from OpenBSD.

eischen (Daniel Eischen) added wrappers to protect against cancled
threads orphaning internal resources.

the cancelability code is still a bit fuzzy but works for test
programs of my own, OpenBSD's and some examples from ORA's books.

add readdir_r to both libc and libc_r

add some 'const' attributes to function parameters

Reviewed by: eischen, jasone

Merge Lite2 changes onto mainline:
- declare opendir2(), which is used to control how readdir() handles
whiteouts etc.

Remove trailing whitespace.

This commit was generated by cvs2svn to compensate for changes in r1539,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite Include Sources