Set time of pool links

This avoid index refresh from various applications.

HISTORY

@@ -13,6 +13,7 @@ SnapRAID HISTORY
    compatibility.
  * Fixed building in platforms that don't provide major/minor definitions
    in sys/types.h.
+ * When creating 'pool' symbolic links, set their time as the linked files.
  * Added support for the Windows 10 symbolic link unprivileged creation,
    using SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE.
  * Windows binaries built with gcc 4.9.4 using the MXE cross compiler at

TODO

@@ -5,9 +5,6 @@ This is the list of TODO items for SnapRAID.
 
 - Next
 
-* When creating links, set the mtime like the linked file.
-See: https://sourceforge.net/p/snapraid/discussion/1677233/thread/936f0087/?limit=25#b3d6
-
 - Minor
 
 * Allow to filter in diff/list by disk name.

cmdline/mingw.c

@@ -1040,6 +1040,70 @@ int windows_futimens(int fd, struct windows_timespec tv[2])
 	return 0;
 }
 
+int windows_utimensat(int fd, const char* file, struct windows_timespec tv[2], int flags)
+{
+	wchar_t conv_buf[CONV_MAX];
+	HANDLE h;
+	FILETIME ft;
+	uint64_t mtime;
+	DWORD wflags;
+
+	/*
+	 * Support only the absolute paths
+	 */
+	if (fd != AT_FDCWD) {
+		errno = EBADF;
+		return -1;
+	}
+
+	/*
+	 * Open the handle of the file.
+	 *
+	 * Use FILE_FLAG_BACKUP_SEMANTICS to open directories (it's just ignored for files).
+	 * Use FILE_FLAG_OPEN_REPARSE_POINT to open symbolic links and not the their target.
+	 *
+	 * Note that even with FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+	 * and FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT some paths
+	 * cannot be opened like "C:\System Volume Information" resulting
+	 * in error ERROR_ACCESS_DENIED.
+	 */
+	wflags = FILE_FLAG_BACKUP_SEMANTICS;
+	if ((flags & AT_SYMLINK_NOFOLLOW) != 0)
+		wflags |= FILE_FLAG_OPEN_REPARSE_POINT;
+	h = CreateFileW(convert(conv_buf, file), 0, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, 0, OPEN_EXISTING, wflags, 0);
+	if (h == INVALID_HANDLE_VALUE) {
+		windows_errno(GetLastError());
+		return -1;
+	}
+
+	/*
+	 * Convert to windows time
+	 *
+	 * How To Convert a UNIX time_t to a Win32 FILETIME or SYSTEMTIME
+	 * http://support.microsoft.com/kb/167296
+	 */
+	mtime = tv[0].tv_sec;
+	mtime *= 10000000;
+	mtime += tv[0].tv_nsec / 100;
+	mtime += 116444736000000000;
+
+	ft.dwHighDateTime = mtime >> 32;
+	ft.dwLowDateTime = mtime;
+
+	if (!SetFileTime(h, 0, 0, &ft)) {
+		windows_errno(GetLastError());
+		CloseHandle(h);
+		return -1;
+	}
+
+	if (!CloseHandle(h)) {
+		windows_errno(GetLastError());
+		return -1;
+	}
+
+	return 0;
+}
+
 int windows_rename(const char* from, const char* to)
 {
 	wchar_t conv_buf_from[CONV_MAX];

cmdline/mingw.h

@@ -85,6 +85,11 @@
 #define HAVE_FUTIMENS 1
 #undef futimens
 #define futimens windows_futimens
+#define HAVE_UTIMENSAT 1
+#define AT_FDCWD -1
+#define AT_SYMLINK_NOFOLLOW 1
+#undef utimensat
+#define utimensat windows_utimensat
 #define O_NOFOLLOW 0
 #define dirent_hidden windows_dirent_hidden
 #define HAVE_STRUCT_DIRENT_D_STAT 1
@@ -241,6 +246,11 @@ struct windows_timespec {
  */
 int windows_futimens(int fd, struct windows_timespec tv[2]);
 
+/**
+ * Like the C utimensat().
+ */
+int windows_utimensat(int fd, const char* file, struct windows_timespec tv[2], int flags);
+
 /**
  * Like the C rename().
  */

cmdline/pool.c

@@ -147,7 +147,7 @@ static int clean_dir(struct snapraid_state* state, const char* dir)
 /**
  * Create a link to the specified disk entry.
  */
-static void make_link(const char* pool_dir, const char* share_dir, struct snapraid_disk* disk, const char* sub)
+static void make_link(const char* pool_dir, const char* share_dir, struct snapraid_disk* disk, const char* sub, int64_t mtime_sec, int mtime_nsec)
 {
 	char path[PATH_MAX];
 	char linkto[PATH_MAX];
@@ -196,6 +196,16 @@ static void make_link(const char* pool_dir, const char* share_dir, struct snapra
 			/* LCOV_EXCL_STOP */
 		}
 	}
+
+	if (mtime_sec) {
+		ret = lmtime(path, mtime_sec, mtime_nsec);
+		if (ret != 0) {
+			/* LCOV_EXCL_START */
+			log_fatal("Error setting time to symlink '%s'. %s.\n", path, strerror(errno));
+			exit(EXIT_FAILURE);
+			/* LCOV_EXCL_STOP */
+		}
+	}
 }
 
 void state_pool(struct snapraid_state* state)
@@ -236,14 +246,14 @@ void state_pool(struct snapraid_state* state)
 		/* for each file */
 		for (j = disk->filelist; j != 0; j = j->next) {
 			struct snapraid_file* file = j->data;
-			make_link(pool_dir, share_dir, disk, file->sub);
+			make_link(pool_dir, share_dir, disk, file->sub, file->mtime_sec, file->mtime_nsec);
 			++count;
 		}
 
 		/* for each link */
 		for (j = disk->linklist; j != 0; j = j->next) {
 			struct snapraid_link* slink = j->data;
-			make_link(pool_dir, share_dir, disk, slink->sub);
+			make_link(pool_dir, share_dir, disk, slink->sub, 0, 0);
 			++count;
 		}
 

cmdline/support.c

@@ -897,6 +897,52 @@ int fmtime(int f, int64_t mtime_sec, int mtime_nsec)
 	return ret;
 }
 
+int lmtime(const char* path, int64_t mtime_sec, int mtime_nsec)
+{
+#if HAVE_UTIMENSAT
+	struct timespec tv[2];
+#else
+	struct timeval tv[2];
+#endif
+	int ret;
+
+#if HAVE_UTIMENSAT /* utimensat() is preferred because it gives nanosecond precision */
+	tv[0].tv_sec = mtime_sec;
+	if (mtime_nsec != STAT_NSEC_INVALID)
+		tv[0].tv_nsec = mtime_nsec;
+	else
+		tv[0].tv_nsec = 0;
+	tv[1].tv_sec = tv[0].tv_sec;
+	tv[1].tv_nsec = tv[0].tv_nsec;
+
+	ret = utimensat(AT_FDCWD, path, tv, AT_SYMLINK_NOFOLLOW);
+#elif HAVE_LUTIMES /* fallback to lutimes() if nanosecond precision is not available */
+	tv[0].tv_sec = mtime_sec;
+	if (mtime_nsec != STAT_NSEC_INVALID)
+		tv[0].tv_usec = mtime_nsec / 1000;
+	else
+		tv[0].tv_usec = 0;
+	tv[1].tv_sec = tv[0].tv_sec;
+	tv[1].tv_usec = tv[0].tv_usec;
+
+	ret = lutimes(path, tv);
+#elif HAVE_FUTIMESAT /* fallback to futimesat() for Solaris, it only has futimesat() */
+	tv[0].tv_sec = mtime_sec;
+	if (mtime_nsec != STAT_NSEC_INVALID)
+		tv[0].tv_usec = mtime_nsec / 1000;
+	else
+		tv[0].tv_usec = 0;
+	tv[1].tv_sec = tv[0].tv_sec;
+	tv[1].tv_usec = tv[0].tv_usec;
+
+	ret = futimesat(AT_FDCWD, path, tv);
+#else
+#error No function available to set file timestamps with sub-second precision
+#endif
+
+	return ret;
+}
+
 /****************************************************************************/
 /* advise */
 

cmdline/support.h

@@ -322,6 +322,12 @@ int mkancestor(const char* file);
  */
 int fmtime(int f, int64_t mtime_sec, int mtime_nsec);
 
+/**
+ * Change the modification time of a file or link.
+ * Note that links are NOT deferenced.
+ */
+int lmtime(const char* path, int64_t mtime_sec, int mtime_nsec);
+
 /****************************************************************************/
 /* advise */
 

configure.ac

@@ -99,7 +99,7 @@ AC_CHECK_FUNCS([getopt getopt_long snprintf vsnprintf sigaction])
 AC_CHECK_FUNCS([ftruncate fallocate access])
 AC_CHECK_FUNCS([fsync posix_fadvise sync_file_range])
 AC_CHECK_FUNCS([getc_unlocked ferror_unlocked fnmatch])
-AC_CHECK_FUNCS([futimes futimens futimesat localtime_r])
+AC_CHECK_FUNCS([futimes futimens futimesat localtime_r lutimes utimensat])
 AC_CHECK_FUNCS([fstatat flock statfs])
 AC_CHECK_FUNCS([mach_absolute_time])
 AC_CHECK_FUNCS([backtrace backtrace_symbols])