X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=lib%2Futimens.c;h=8d8bef468ecdef2f444f2434d20cdbdbe3e0a31b;hb=2ddb59ff29a52f07859d76eeb92dc7cfded8bbc6;hp=0b2f3e4d091f5b7568d4241db93e63910effe706;hpb=9a66010992ca6ea590f26fc89362b5b288e5ffbd;p=gnulib.git

diff --git a/lib/utimens.c b/lib/utimens.c
index 0b2f3e4d0..8d8bef468 100644
--- a/lib/utimens.c
+++ b/lib/utimens.c
@@ -26,6 +26,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <unistd.h>
 
 #if HAVE_UTIME_H
 # include <utime.h>
@@ -41,6 +42,16 @@ struct utimbuf
 };
 #endif
 
+/* Some systems don't have ENOSYS.  */
+#ifndef ENOSYS
+# ifdef ENOTSUP
+#  define ENOSYS ENOTSUP
+# else
+/* Some systems don't have ENOTSUP either.  */
+#  define ENOSYS EINVAL
+# endif
+#endif
+
 #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
 # define __attribute__(x)
 #endif
@@ -53,7 +64,11 @@ struct utimbuf
    TIMESPEC[0] and TIMESPEC[1], respectively.
    FD must be either negative -- in which case it is ignored --
    or a file descriptor that is open on FILE.
-   If TIMESPEC is null, set the time stamps to the current time.  */
+   If FD is nonnegative, then FILE can be NULL, which means
+   use just futimes (or equivalent) instead of utimes (or equivalent),
+   and fail if on an old system without futimes (or equivalent).
+   If TIMESPEC is null, set the time stamps to the current time.
+   Return 0 on success, -1 (setting errno) on failure.  */
 
 int
 futimens (int fd ATTRIBUTE_UNUSED,
@@ -78,42 +93,64 @@ futimens (int fd ATTRIBUTE_UNUSED,
 
 # if HAVE_FUTIMESAT
   return fd < 0 ? futimesat (AT_FDCWD, file, t) : futimesat (fd, NULL, t);
-# else
-#  if HAVE_FUTIMES
+# elif HAVE_FUTIMES
   if (0 <= fd)
     {
       if (futimes (fd, t) == 0)
 	return 0;
 
-      /* On GNU/Linux without the futimes syscall and without /proc
-	 mounted, glibc futimes fails with errno == ENOENT.  Fall back
-	 on utimes if we get a weird error number like that.  */
-      switch (errno)
-	{
-	case EACCES:
-	case EIO:
-	case EPERM:
-	case EROFS:
-	  return -1;
-	}
+      /* Don't worry about trying to speed things up by returning right
+	 away here.  glibc futimes can incorrectly fail with errno ==
+	 ENOENT if /proc isn't mounted.  Also, Mandrake 10.0 in high
+	 security mode doesn't allow ordinary users to read /proc/self, so
+	 glibc futimes incorrectly fails with errno == EACCES.  If futimes
+	 fails with errno == EIO, EPERM, or EROFS, it's probably safe to
+	 fail right away, but these cases are rare enough that they're not
+	 worth optimizing, and who knows what other messed-up systems are
+	 out there?  So play it safe and fall back on the code below.  */
     }
-#  endif
-  return utimes (file, t);
 # endif
+#endif
 
-#else
+#if ! HAVE_FUTIMESAT
 
-  struct utimbuf utimbuf;
-  struct utimbuf const *t;
-  if (timespec)
+  if (!file)
     {
-      utimbuf.actime = timespec[0].tv_sec;
-      utimbuf.modtime = timespec[1].tv_sec;
-      t = &utimbuf;
+# if ! (HAVE_WORKING_UTIMES && HAVE_FUTIMES)
+      errno = ENOSYS;
+# endif
+
+      /* Prefer EBADF to ENOSYS if both error numbers apply.  */
+      if (errno == ENOSYS)
+	{
+	  int fd2 = dup (fd);
+	  int dup_errno = errno;
+	  if (0 <= fd2)
+	    close (fd2);
+	  errno = (fd2 < 0 && dup_errno == EBADF ? EBADF : ENOSYS);
+	}
+
+      return -1;
     }
-  else
-    t = NULL;
-  return utime (file, t);
+
+# if HAVE_WORKING_UTIMES
+  return utimes (file, t);
+# else
+  {
+    struct utimbuf utimbuf;
+    struct utimbuf const *ut;
+    if (timespec)
+      {
+	utimbuf.actime = timespec[0].tv_sec;
+	utimbuf.modtime = timespec[1].tv_sec;
+	ut = &utimbuf;
+      }
+    else
+      ut = NULL;
+
+    return utime (file, ut);
+  }
+# endif
 
 #endif
 }