[BZ #5778]

	* sysdeps/unix/sysv/linux/pathconf.h: Declare
	__statfs_chown_restricted.
	* sysdeps/unix/sysv/linux/fpathconf.c: Call __statfs_chown_restricted
	for _PC_CHOWN_RESTRICTED.
	* sysdeps/unix/sysv/linux/pathconf.c: Likewise.
	Implement __statfs_chown_restricted.
	* sysdeps/unix/sysv/linux/bits/posix_opt.h: Change
	_POSIX_CHOWN_RESTRICTED value to zero.

2008-02-26  Harsha Jagasia  <harsha.jagasia@amd.com>

4 files changed, 64 insertions, 9 deletions

diff --git a/sysdeps/unix/sysv/linux/bits/posix_opt.h b/sysdeps/unix/sysv/linux/bits/posix_opt.h
index 1a96db2982..37612e0bd5 100644
--- a/sysdeps/unix/sysv/linux/bits/posix_opt.h
+++ b/sysdeps/unix/sysv/linux/bits/posix_opt.h
@@ -1,5 +1,6 @@
 /* Define POSIX options for Linux.
-   Copyright (C) 1996,1997,1999,2000,2002,2003 Free Software Foundation, Inc.
+   Copyright (C) 1996,1997,1999,2000,2002,2003,2008
+   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
@@ -51,8 +52,8 @@
 /* Setting of memory protections is supported.  */
 #define	_POSIX_MEMORY_PROTECTION	200112L
 
-/* Only root can change owner of file.  */
-#define	_POSIX_CHOWN_RESTRICTED	1
+/* Some filesystems allow all users to change file ownership.  */
+#define	_POSIX_CHOWN_RESTRICTED	0
 
 /* `c_cc' member of 'struct termios' structure can be disabled by
    using the value _POSIX_VDISABLE.  */
diff --git a/sysdeps/unix/sysv/linux/fpathconf.c b/sysdeps/unix/sysv/linux/fpathconf.c
index c1cdb1b899..2701c9ec99 100644
--- a/sysdeps/unix/sysv/linux/fpathconf.c
+++ b/sysdeps/unix/sysv/linux/fpathconf.c
@@ -1,5 +1,5 @@
 /* Get file-specific information about descriptor FD.  Linux version.
-   Copyright (C) 1991,1995,1996,1998-2002,2003 Free Software Foundation, Inc.
+   Copyright (C) 1991,1995,1996,1998-2003,2008 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
@@ -45,6 +45,9 @@ __fpathconf (fd, name)
     case _PC_2_SYMLINKS:
       return __statfs_symlinks (__fstatfs (fd, &fsbuf), &fsbuf);
 
+    case _PC_CHOWN_RESTRICTED:
+      return __statfs_chown_restricted (__fstatfs (fd, &fsbuf), &fsbuf);
+
     default:
       return posix_fpathconf (fd, name);
     }
diff --git a/sysdeps/unix/sysv/linux/pathconf.c b/sysdeps/unix/sysv/linux/pathconf.c
index e12a08434a..db03529fe8 100644
--- a/sysdeps/unix/sysv/linux/pathconf.c
+++ b/sysdeps/unix/sysv/linux/pathconf.c
@@ -1,5 +1,5 @@
 /* Get file-specific information about a file.  Linux version.
-   Copyright (C) 1991,1995,1996,1998-2002,2003 Free Software Foundation, Inc.
+   Copyright (C) 1991,1995,1996,1998-2003,2008 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
@@ -19,8 +19,10 @@
 
 #include <unistd.h>
 #include <errno.h>
+
 #include "pathconf.h"
 #include "linux_fsinfo.h"
+#include <not-cancel.h>
 
 static long int posix_pathconf (const char *file, int name);
 
@@ -46,6 +48,9 @@ __pathconf (const char *file, int name)
     case _PC_2_SYMLINKS:
       return __statfs_symlinks (__statfs (file, &fsbuf), &fsbuf);
 
+    case _PC_CHOWN_RESTRICTED:
+      return __statfs_chown_restricted (__statfs (file, &fsbuf), &fsbuf);
+
     default:
       return posix_pathconf (file, name);
     }
@@ -179,3 +184,44 @@ __statfs_symlinks (int result, const struct statfs *fsbuf)
       return 1;
     }
 }
+
+
+/* Used like: return __statfs_chown_restricted (__statfs (name, &buf), &buf);*/
+long int
+__statfs_chown_restricted (int result, const struct statfs *fsbuf)
+{
+  if (result < 0)
+    {
+      if (errno == ENOSYS)
+	/* Not possible, return the default value.  */
+	return 1;
+
+      /* Some error occured.  */
+      return -1;
+    }
+
+  int fd;
+  long int retval = 1;
+  switch (fsbuf->f_type)
+    {
+    case XFS_SUPER_MAGIC:
+      /* Read the value from /proc/sys/fs/xfs/restrict_chown.  If we cannot
+	 read it default to assume the restriction is in place.  */
+      fd = open_not_cancel_2 ("/proc/sys/fs/xfs/restrict_chown", O_RDONLY);
+      if (fd != -1)
+	{
+	  char buf[2];
+	  if (TEMP_FAILURE_RETRY (read_not_cancel (fd, buf, 2)) == 2
+	      && buf[0] >= '0' && buf[0] <= '1')
+	    retval = buf[0] - '0';
+
+	  close_not_cancel_no_status (fd);
+	}
+      break;
+
+    default:
+      break;
+    }
+
+  return retval;
+}
diff --git a/sysdeps/unix/sysv/linux/pathconf.h b/sysdeps/unix/sysv/linux/pathconf.h
index 20e23685eb..806adcc5ea 100644
--- a/sysdeps/unix/sysv/linux/pathconf.h
+++ b/sysdeps/unix/sysv/linux/pathconf.h
@@ -1,5 +1,5 @@
 /* Common parts of Linux implementation of pathconf and fpathconf.
-   Copyright (C) 1991,1995,1996,1998-2002,2003 Free Software Foundation, Inc.
+   Copyright (C) 1991,1995,1996,1998-2003,2008 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
@@ -22,13 +22,18 @@
 #include <sys/statfs.h>
 
 
-/* Used like: return statfs_link_max (__statfs (name, &buf), &buf); */
+/* Used like: return __statfs_link_max (__statfs (name, &buf), &buf); */
 extern long int __statfs_link_max (int result, const struct statfs *fsbuf);
 
 
-/* Used like: return statfs_filesize_max (__statfs (name, &buf), &buf); */
+/* Used like: return __statfs_filesize_max (__statfs (name, &buf), &buf); */
 extern long int __statfs_filesize_max (int result, const struct statfs *fsbuf);
 
 
-/* Used like: return statfs_link_max (__statfs (name, &buf), &buf); */
+/* Used like: return __statfs_link_max (__statfs (name, &buf), &buf); */
 extern long int __statfs_symlinks (int result, const struct statfs *fsbuf);
+
+
+/* Used like: return __statfs_chown_restricted (__statfs (name, &buf), &buf);*/
+extern long int __statfs_chown_restricted (int result,
+					   const struct statfs *fsbuf);