/* Avoid recursion with rpl_futimens. */
#undef futimens
+#if HAVE_UTIMENSAT || HAVE_FUTIMENS
+/* Cache variable for whether syscall works; used to avoid calling the
+ syscall if we know it will just fail with ENOSYS. 0 = unknown, 1 =
+ yes, -1 = no. */
+static int utimensat_works_really;
+#endif /* HAVE_UTIMENSAT || HAVE_UTIMENSAT */
+
/* Validate the requested timestamps. Return 0 if the resulting
timespec can be used for utimensat (after possibly modifying it to
work around bugs in utimensat). Return 1 if the timespec needs
#endif
/* POSIX 2008 added two interfaces to set file timestamps with
- nanosecond resolution. We provide a fallback for ENOSYS (for
- example, compiling against Linux 2.6.25 kernel headers and glibc
- 2.7, but running on Linux 2.6.18 kernel). */
-#if HAVE_UTIMENSAT
- if (fd < 0)
+ nanosecond resolution; newer Linux implements both functions via
+ a single syscall. We provide a fallback for ENOSYS (for example,
+ compiling against Linux 2.6.25 kernel headers and glibc 2.7, but
+ running on Linux 2.6.18 kernel). */
+#if HAVE_UTIMENSAT || HAVE_FUTIMENS
+ if (0 <= utimensat_works_really)
{
- int result = utimensat (AT_FDCWD, file, ts, 0);
-# ifdef __linux__
- /* Work around a kernel bug:
- http://bugzilla.redhat.com/442352
- http://bugzilla.redhat.com/449910
- It appears that utimensat can mistakenly return 280 rather
- than -1 upon failure.
- FIXME: remove in 2010 or whenever the offending kernels
- are no longer in common use. */
- if (0 < result)
- errno = ENOSYS;
-# endif
-
- if (result == 0 || errno != ENOSYS)
- return result;
+# if HAVE_UTIMENSAT
+ if (fd < 0)
+ {
+ int result = utimensat (AT_FDCWD, file, ts, 0);
+# ifdef __linux__
+ /* Work around a kernel bug:
+ http://bugzilla.redhat.com/442352
+ http://bugzilla.redhat.com/449910
+ It appears that utimensat can mistakenly return 280 rather
+ than -1 upon ENOSYS failure.
+ FIXME: remove in 2010 or whenever the offending kernels
+ are no longer in common use. */
+ if (0 < result)
+ errno = ENOSYS;
+# endif /* __linux__ */
+ if (result == 0 || errno != ENOSYS)
+ {
+ utimensat_works_really = 1;
+ return result;
+ }
+ }
+# endif /* HAVE_UTIMENSAT */
+# if HAVE_FUTIMENS
+ {
+ int result = futimens (fd, timespec);
+# ifdef __linux__
+ /* Work around the same bug as above. */
+ if (0 < result)
+ errno = ENOSYS;
+# endif /* __linux__ */
+ if (result == 0 || errno != ENOSYS)
+ {
+ utimensat_works_really = 1;
+ return result;
+ }
+ }
+# endif /* HAVE_FUTIMENS */
}
-#endif
-#if HAVE_FUTIMENS
- {
- int result = futimens (fd, timespec);
-# ifdef __linux__
- /* Work around the same bug as above. */
- if (0 < result)
- errno = ENOSYS;
-# endif
- if (result == 0 || errno != ENOSYS)
- return result;
- }
-#endif
+ utimensat_works_really = -1;
+#endif /* HAVE_UTIMENSAT || HAVE_FUTIMENS */
/* The platform lacks an interface to set file timestamps with
nanosecond resolution, so do the best we can, discarding any
worry about bogus return values. */
#if HAVE_UTIMENSAT
- {
- int result = utimensat (AT_FDCWD, file, ts, AT_SYMLINK_NOFOLLOW);
+ if (0 <= utimensat_works_really)
+ {
+ int result = utimensat (AT_FDCWD, file, ts, AT_SYMLINK_NOFOLLOW);
# ifdef __linux__
- /* Work around a kernel bug:
- http://bugzilla.redhat.com/442352
- http://bugzilla.redhat.com/449910
- It appears that utimensat can mistakenly return 280 rather
- than -1 upon ENOSYS failure.
- FIXME: remove in 2010 or whenever the offending kernels
- are no longer in common use. */
- if (0 < result)
- errno = ENOSYS;
+ /* Work around a kernel bug:
+ http://bugzilla.redhat.com/442352
+ http://bugzilla.redhat.com/449910
+ It appears that utimensat can mistakenly return 280 rather
+ than -1 upon ENOSYS failure.
+ FIXME: remove in 2010 or whenever the offending kernels
+ are no longer in common use. */
+ if (0 < result)
+ errno = ENOSYS;
# endif
-
- if (result == 0 || errno != ENOSYS)
- return result;
- }
+ if (result == 0 || errno != ENOSYS)
+ {
+ utimensat_works_really = 1;
+ return result;
+ }
+ }
+ utimensat_works_really = -1;
#endif /* HAVE_UTIMENSAT */
/* The platform lacks an interface to set file timestamps with