Optimize fdopendir a bit.

Don't call fcntl(F_SETFD) unnecessarily.

ChangeLog

@@ -1,3 +1,12 @@
+2011-05-08  Ulrich Drepper  <drepper@gmail.com>
+
+	* include/dirent.h (__alloc_dir): Add flags parameter.
+	* sysdeps/unix/fdopendir.c (__fdopendir): Pass flags to __alloc_dir.
+	* sysdeps/unix/opendir.c (__opendir): Pass 0 in new parameter to
+	__alloc_dir.
+	(__alloc_dir): Take new parameter.  Don't call fcntl for invocations
+	from fdopendir if O_CLOEXEC is already set.
+
 2011-03-15  Alan Modra  <amodra@gmail.com>
 
 	* elf/dl-reloc.c (_dl_try_allocate_static_tls <TLS_DTV_AT_TP>): Handle

include/dirent.h

@@ -28,7 +28,8 @@ extern int __alphasort64 (const struct dirent64 **a, const struct dirent64 **b)
 extern int __versionsort64 (const struct dirent64 **a,
 			    const struct dirent64 **b)
      __attribute_pure__;
-extern DIR *__alloc_dir (int fd, bool close_fd, const struct stat64 *statp)
+extern DIR *__alloc_dir (int fd, bool close_fd, int flags,
+			 const struct stat64 *statp)
      internal_function;
 
 #endif

sysdeps/unix/fdopendir.c

@@ -1,4 +1,4 @@
-/* Copyright (C) 2005, 2006 Free Software Foundation, Inc.
+/* Copyright (C) 2005, 2006, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -47,6 +47,6 @@ __fdopendir (int fd)
       return NULL;
     }
 
-  return __alloc_dir (fd, false, &statbuf);
+  return __alloc_dir (fd, false, flags, &statbuf);
 }
 weak_alias (__fdopendir, fdopendir)

sysdeps/unix/opendir.c

@@ -1,4 +1,4 @@
-/* Copyright (C) 1991-1996,98,2000-2003,2005,2007,2009
+/* Copyright (C) 1991-1996,98,2000-2003,2005,2007,2009,2011
    Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -138,7 +138,7 @@ __opendir (const char *name)
       statp = &statbuf;
     }
 
-  return __alloc_dir (fd, true, statp);
+  return __alloc_dir (fd, true, 0, statp);
 }
 weak_alias (__opendir, opendir)
 
@@ -158,13 +158,14 @@ check_have_o_cloexec (int fd)
 
 DIR *
 internal_function
-__alloc_dir (int fd, bool close_fd, const struct stat64 *statp)
+__alloc_dir (int fd, bool close_fd, int flags, const struct stat64 *statp)
 {
   /* We always have to set the close-on-exit flag if the user provided
      the file descriptor.  Otherwise only if we have no working
      O_CLOEXEC support.  */
 #ifdef O_CLOEXEC
-  if (! close_fd || ! check_have_o_cloexec (fd))
+  if ((! close_fd && (flags & O_CLOEXEC) == 0)
+      || ! check_have_o_cloexec (fd))
 #endif
     {
       if (__builtin_expect (__fcntl (fd, F_SETFD, FD_CLOEXEC), 0) < 0)