Remove PIPE_BUF Linux-specific code

Fixes BZ #12723

The variable pipe buffer size does nothing to the value of PIPE_BUF,
since the number of bytes that are atomically written is still
PIPE_BUF on Linux.

ChangeLog

@@ -1,3 +1,12 @@
+2013-03-07  Siddhesh Poyarekar  <siddhesh@redhat.com>
+
+	[BZ #12723]
+	* posix/Makefile (tests): Add tst-pathconf.
+	* posix/tst-pathconf.c: New test case.
+	* sysdeps/unix/sysv/linux/fpathconf.c (__fpathconf): Remove
+	_PC_PIPE_BUF.
+	* sysdeps/unix/sysv/linux/pathconf.c (__pathconf): Likewise.
+
 2013-03-06  Patsy Franklin  <pfrankli@redhat.com>
 
 	* io/fcntl.h: Added a comment about AT_EACCESS and AT_REMOVEDIR.

NEWS

@@ -9,9 +9,9 @@ Version 2.18
 
 * The following bugs are resolved with this release:
 
-  11561, 13550, 13951, 14142, 14200, 14317, 14327, 14496, 14920, 14964,
+  11561, 12723, 13550, 13951, 14142, 14200, 14317, 14327, 14496, 14920,
-  14981, 14982, 14985, 14994, 14996, 15003, 15006, 15020, 15023, 15036,
+  14964, 14981, 14982, 14985, 14994, 14996, 15003, 15006, 15020, 15023,
-  15054, 15055, 15062, 15078, 15160, 15232.
+  15036, 15054, 15055, 15062, 15078, 15160, 15232.
 
 * Add support for calling C++11 thread_local object destructors on thread
   and program exit.  This needs compiler support for offloading C++11

posix/Makefile

@@ -86,7 +86,8 @@ tests		:= tstgetopt testfnm runtests runptests	     \
 		   tst-rfc3484-3 \
 		   tst-getaddrinfo3 tst-fnmatch2 tst-cpucount tst-cpuset \
 		   bug-getopt1 bug-getopt2 bug-getopt3 bug-getopt4 \
-		   bug-getopt5 tst-getopt_long1 bug-regex34 bug-regex35
+		   bug-getopt5 tst-getopt_long1 bug-regex34 bug-regex35 \
+		   tst-pathconf
 xtests		:= bug-ga2
 ifeq (yes,$(build-shared))
 test-srcs	:= globtest

posix/tst-pathconf.c

@@ -0,0 +1,176 @@
+/* Test that values of pathconf and fpathconf are consistent for a file.
+   Copyright (C) 2013 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+
+static void prepare (void);
+#define PREPARE(argc, argv) prepare ()
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+
+#include "../test-skeleton.c"
+
+static int dir_fd;
+static char *dirbuf;
+
+static void
+prepare (void)
+{
+  size_t test_dir_len = strlen (test_dir);
+  static const char dir_name[] = "/tst-pathconf.XXXXXX";
+
+  size_t dirbuflen = test_dir_len + sizeof (dir_name);
+  dirbuf = malloc (dirbuflen);
+  if (dirbuf == NULL)
+    {
+      puts ("Out of memory");
+      exit (1);
+    }
+
+  snprintf (dirbuf, dirbuflen, "%s%s", test_dir, dir_name);
+  if (mkdtemp (dirbuf) == NULL)
+    {
+      printf ("Cannot create temporary directory: %s\n", strerror (errno));
+      exit (1);
+    }
+
+  add_temp_file (dirbuf);
+
+  dir_fd = open (dirbuf, O_RDONLY);
+  if (dir_fd == -1)
+    {
+      printf ("Cannot open directory: %s\n", strerror (errno));
+      exit (1);
+    }
+}
+
+
+static int
+do_test (void)
+{
+  int ret = 0;
+  static const char *fifo_name = "some-fifo";
+
+  size_t filenamelen = strlen (dirbuf) + strlen (fifo_name) + 2;
+  char *filename = malloc (filenamelen);
+
+  snprintf (filename, filenamelen, "%s/%s", dirbuf, fifo_name);
+
+  /* Create a fifo in the directory.  */
+  int e = mkfifo (filename, 0777);
+  if (e == -1)
+    {
+      printf ("fifo creation failed (%s)\n", strerror (errno));
+      ret = 1;
+      goto out_nofifo;
+    }
+
+  long dir_pathconf = pathconf (dirbuf, _PC_PIPE_BUF);
+
+  if (dir_pathconf < 0)
+    {
+      printf ("pathconf on directory failed: %s\n", strerror (errno));
+      ret = 1;
+      goto out_nofifo;
+    }
+
+  long fifo_pathconf = pathconf (filename, _PC_PIPE_BUF);
+
+  if (fifo_pathconf < 0)
+    {
+      printf ("pathconf on file failed: %s\n", strerror (errno));
+      ret = 1;
+      goto out_nofifo;
+    }
+
+  int fifo = open (filename, O_RDONLY | O_NONBLOCK);
+
+  if (fifo < 0)
+    {
+      printf ("fifo open failed (%s)\n", strerror (errno));
+      ret = 1;
+      goto out_nofifo;
+    }
+
+  long dir_fpathconf = fpathconf (dir_fd, _PC_PIPE_BUF);
+
+  if (dir_fpathconf < 0)
+    {
+      printf ("fpathconf on directory failed: %s\n", strerror (errno));
+      ret = 1;
+      goto out;
+    }
+
+  long fifo_fpathconf = fpathconf (fifo, _PC_PIPE_BUF);
+
+  if (fifo_fpathconf < 0)
+    {
+      printf ("fpathconf on file failed: %s\n", strerror (errno));
+      ret = 1;
+      goto out;
+    }
+
+  if (fifo_pathconf != fifo_fpathconf)
+    {
+      printf ("fifo pathconf (%ld) != fifo fpathconf (%ld)\n", fifo_pathconf,
+	      fifo_fpathconf);
+      ret = 1;
+      goto out;
+    }
+
+  if (dir_pathconf != fifo_pathconf)
+    {
+      printf ("directory pathconf (%ld) != fifo pathconf (%ld)\n",
+	      dir_pathconf, fifo_pathconf);
+      ret = 1;
+      goto out;
+    }
+
+  if (dir_fpathconf != fifo_fpathconf)
+    {
+      printf ("directory fpathconf (%ld) != fifo fpathconf (%ld)\n",
+	      dir_fpathconf, fifo_fpathconf);
+      ret = 1;
+      goto out;
+    }
+
+out:
+  close (fifo);
+out_nofifo:
+  close (dir_fd);
+
+  if (unlink (filename) != 0)
+    {
+      printf ("Could not remove fifo (%s)\n", strerror (errno));
+      ret = 1;
+    }
+
+  if (rmdir (dirbuf) != 0)
+    {
+      printf ("Could not remove directory (%s)\n", strerror (errno));
+      ret = 1;
+    }
+
+  return ret;
+}

sysdeps/unix/sysv/linux/fpathconf.c

@@ -33,7 +33,6 @@ __fpathconf (fd, name)
      int name;
 {
   struct statfs fsbuf;
-  int r;
 
   switch (name)
     {
@@ -49,12 +48,6 @@ __fpathconf (fd, name)
     case _PC_CHOWN_RESTRICTED:
       return __statfs_chown_restricted (__fstatfs (fd, &fsbuf), &fsbuf);
 
-    case _PC_PIPE_BUF:
-      r = __fcntl (fd, F_GETPIPE_SZ);
-      if (r > 0)
-	return r;
-      /* FALLTHROUGH */
-
     default:
       return posix_fpathconf (fd, name);
     }

sysdeps/unix/sysv/linux/pathconf.c

@@ -39,8 +39,6 @@ long int
 __pathconf (const char *file, int name)
 {
   struct statfs fsbuf;
-  int fd;
-  int flags;
 
   switch (name)
     {
@@ -56,21 +54,6 @@ __pathconf (const char *file, int name)
     case _PC_CHOWN_RESTRICTED:
       return __statfs_chown_restricted (__statfs (file, &fsbuf), &fsbuf);
 
-    case _PC_PIPE_BUF:
-      flags = O_RDONLY|O_NONBLOCK|O_NOCTTY;
-#ifdef O_CLOEXEC
-      flags |= O_CLOEXEC;
-#endif
-      fd = open_not_cancel_2 (file, flags);
-      if (fd >= 0)
-	{
-	  long int r = __fcntl (fd, F_GETPIPE_SZ);
-	  close_not_cancel_no_status (fd);
-	  if (r > 0)
-	    return r;
-	}
-      /* FALLTHROUGH */
-
     default:
       return posix_pathconf (file, name);
     }