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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 17:39:29 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 17:39:29 +0000
commit8ffec2a3aba6f114784e11f89ef1d57a096ae540 (patch)
treeccebcbad06203e8241a8e7249f8e6c478a3682ea /lib/utimensat.c
parentInitial commit. (diff)
downloadcoreutils-8ffec2a3aba6f114784e11f89ef1d57a096ae540.tar.xz
coreutils-8ffec2a3aba6f114784e11f89ef1d57a096ae540.zip
Adding upstream version 8.32.upstream/8.32upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/utimensat.c')
-rw-r--r--lib/utimensat.c160
1 files changed, 160 insertions, 0 deletions
diff --git a/lib/utimensat.c b/lib/utimensat.c
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+/* Set the access and modification time of a file relative to directory fd.
+ Copyright (C) 2009-2020 Free Software Foundation, Inc.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* written by Eric Blake */
+
+#include <config.h>
+
+/* Specification. */
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+
+#include "stat-time.h"
+#include "timespec.h"
+#include "utimens.h"
+
+#if HAVE_UTIMENSAT
+
+# undef utimensat
+
+/* If we have a native utimensat, but are compiling this file, then
+ utimensat was defined to rpl_utimensat by our replacement
+ sys/stat.h. We assume the native version might fail with ENOSYS,
+ or succeed without properly affecting ctime (as is the case when
+ using newer glibc but older Linux kernel). In this scenario,
+ rpl_utimensat checks whether the native version is usable, and
+ local_utimensat provides the fallback manipulation. */
+
+static int local_utimensat (int, char const *, struct timespec const[2], int);
+# define AT_FUNC_NAME local_utimensat
+
+/* Like utimensat, but work around native bugs. */
+
+int
+rpl_utimensat (int fd, char const *file, struct timespec const times[2],
+ int flag)
+{
+# if defined __linux__ || defined __sun
+ struct timespec ts[2];
+# endif
+
+ /* See comments in utimens.c for details. */
+ static int utimensat_works_really; /* 0 = unknown, 1 = yes, -1 = no. */
+ if (0 <= utimensat_works_really)
+ {
+ int result;
+# if defined __linux__ || defined __sun
+ struct stat st;
+ /* As recently as Linux kernel 2.6.32 (Dec 2009), several file
+ systems (xfs, ntfs-3g) have bugs with a single UTIME_OMIT,
+ but work if both times are either explicitly specified or
+ UTIME_NOW. Work around it with a preparatory [l]stat prior
+ to calling utimensat; fortunately, there is not much timing
+ impact due to the extra syscall even on file systems where
+ UTIME_OMIT would have worked.
+
+ The same bug occurs in Solaris 11.1 (Apr 2013).
+
+ FIXME: Simplify this in 2024, when these file system bugs are
+ no longer common on Gnulib target platforms. */
+ if (times && (times[0].tv_nsec == UTIME_OMIT
+ || times[1].tv_nsec == UTIME_OMIT))
+ {
+ if (fstatat (fd, file, &st, flag))
+ return -1;
+ if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT)
+ return 0;
+ if (times[0].tv_nsec == UTIME_OMIT)
+ ts[0] = get_stat_atime (&st);
+ else
+ ts[0] = times[0];
+ if (times[1].tv_nsec == UTIME_OMIT)
+ ts[1] = get_stat_mtime (&st);
+ else
+ ts[1] = times[1];
+ times = ts;
+ }
+# ifdef __hppa__
+ /* Linux kernel 2.6.22.19 on hppa does not reject invalid tv_nsec
+ values. */
+ else if (times
+ && ((times[0].tv_nsec != UTIME_NOW
+ && ! (0 <= times[0].tv_nsec
+ && times[0].tv_nsec < TIMESPEC_HZ))
+ || (times[1].tv_nsec != UTIME_NOW
+ && ! (0 <= times[1].tv_nsec
+ && times[1].tv_nsec < TIMESPEC_HZ))))
+ {
+ errno = EINVAL;
+ return -1;
+ }
+# endif
+# endif
+ result = utimensat (fd, file, times, flag);
+ /* Linux kernel 2.6.25 has a bug where it returns EINVAL for
+ UTIME_NOW or UTIME_OMIT with non-zero tv_sec, which
+ local_utimensat works around. Meanwhile, EINVAL for a bad
+ flag is indeterminate whether the native utimensat works, but
+ local_utimensat will also reject it. */
+ if (result == -1 && errno == EINVAL && (flag & ~AT_SYMLINK_NOFOLLOW))
+ return result;
+ if (result == 0 || (errno != ENOSYS && errno != EINVAL))
+ {
+ utimensat_works_really = 1;
+ return result;
+ }
+ }
+ /* No point in trying openat/futimens, since on Linux, futimens is
+ implemented with the same syscall as utimensat. Only avoid the
+ native utimensat due to an ENOSYS failure; an EINVAL error was
+ data-dependent, and the next caller may pass valid data. */
+ if (0 <= utimensat_works_really && errno == ENOSYS)
+ utimensat_works_really = -1;
+ return local_utimensat (fd, file, times, flag);
+}
+
+#else /* !HAVE_UTIMENSAT */
+
+# define AT_FUNC_NAME utimensat
+
+#endif /* !HAVE_UTIMENSAT */
+
+/* Set the access and modification timestamps of FILE to be
+ TIMESPEC[0] and TIMESPEC[1], respectively; relative to directory
+ FD. If flag is AT_SYMLINK_NOFOLLOW, change the times of a symlink,
+ or fail with ENOSYS if not possible. If TIMESPEC is null, set the
+ timestamps to the current time. If possible, do it without
+ changing the working directory. Otherwise, resort to using
+ save_cwd/fchdir, then utimens/restore_cwd. If either the save_cwd
+ or the restore_cwd fails, then give a diagnostic and exit nonzero.
+ Return 0 on success, -1 (setting errno) on failure. */
+
+/* AT_FUNC_NAME is now utimensat or local_utimensat. */
+#define AT_FUNC_F1 lutimens
+#define AT_FUNC_F2 utimens
+#define AT_FUNC_USE_F1_COND AT_SYMLINK_NOFOLLOW
+#define AT_FUNC_POST_FILE_PARAM_DECLS , struct timespec const ts[2], int flag
+#define AT_FUNC_POST_FILE_ARGS , ts
+#include "at-func.c"
+#undef AT_FUNC_NAME
+#undef AT_FUNC_F1
+#undef AT_FUNC_F2
+#undef AT_FUNC_USE_F1_COND
+#undef AT_FUNC_POST_FILE_PARAM_DECLS
+#undef AT_FUNC_POST_FILE_ARGS