added --backup-dir option from Bob Edwards

this is very useful for incremental backups

1 files changed, 134 insertions, 1 deletions

diff --git a/backup.c b/backup.c
index 54d5fae8..24f8523a 100644
--- a/backup.c
+++ b/backup.c
@@ -22,9 +22,11 @@
 
 extern int verbose;
 extern char *backup_suffix;
+extern char *backup_dir;
 
 
-int make_backup(char *fname)
+/* simple backup creates a backup with a suffix in the same directory */
+static int make_simple_backup(char *fname)
 {
 	char fnamebak[MAXPATHLEN];
 	if (strlen(fname) + strlen(backup_suffix) > (MAXPATHLEN-1)) {
@@ -44,3 +46,134 @@ int make_backup(char *fname)
 	}
 	return 1;
 }
+
+
+/* recursively make a directory path */
+static int make_dir(char *name, int mask)
+{
+	char newdir [MAXPATHLEN];
+	char *p, *d;
+
+	/* copy pathname over, look for last '/' */
+	for (p = d = newdir; *name; *d++ = *name++)
+		if (*name == '/')
+			p = d;
+	if (p == newdir)
+		return 0;
+	*p = 0;
+
+	/* make the new directory, if that fails then make its parent */
+	while (do_mkdir (newdir, mask) != 0)
+		if ((errno != ENOENT) || !make_dir (newdir, mask))
+			return 0;
+
+	return 1;
+} /* make_dir */
+
+
+/* robustly move a file, creating new directory structures if necessary */
+static int robust_move(char *src, char *dst)
+{
+	int keep_trying = 4;
+	int keep_path_extfs = 0;
+	int failed;
+
+	while (keep_trying) {
+		if (keep_path_extfs)
+			failed = copy_file (src, dst, 0755);
+		else
+			failed = robust_rename (src, dst);
+
+		if (failed) {
+			if (verbose > 2)
+				rprintf (FERROR, "robust_move failed: %s(%d)\n",
+					strerror (errno), errno);
+			switch (errno) {
+				/* external filesystem */
+				case EXDEV:
+					keep_path_extfs = 1;
+					keep_trying--;
+					break;
+				/* no directory to write to */
+				case ENOENT:
+					make_dir (dst, 0755);
+					keep_trying--;
+					break;
+				default:
+					keep_trying = 0;
+			} /* switch */
+		} else
+			keep_trying = 0;
+	} /* while */
+	return (!failed);
+} /* robust_move */
+
+
+/* if we have a backup_dir, then we get here from make_backup().
+   We will move the file to be deleted into a parallel directory tree */
+static int keep_backup(char *fname)
+{
+	static int initialised;
+
+	char keep_name [MAXPATHLEN];
+	STRUCT_STAT st;
+	struct file_struct *file;
+
+	if (!initialised) {
+		if (backup_dir[strlen(backup_dir) - 1] == '/')
+			backup_dir[strlen(backup_dir) - 1] = 0;
+		if (verbose > 0)
+			rprintf (FINFO, "backup_dir is %s\n", backup_dir);
+		initialised = 1;
+	}
+
+	/* return if no file to keep */
+#if SUPPORT_LINKS
+	if (do_lstat (fname, &st)) return 1;
+#else
+	if (do_stat (fname, &st)) return 1;
+#endif
+
+	file = make_file (0, fname);
+
+	/* make a complete pathname for backup file */
+	if (strlen(backup_dir) + strlen(fname) > (MAXPATHLEN - 1)) {
+		rprintf (FERROR, "keep_backup filename too long\n");
+		return 0;
+	}
+	slprintf(keep_name, sizeof (keep_name), "%s/%s", backup_dir, fname);
+
+	if (!S_ISDIR(file->mode)) {
+	/* move to keep tree if a file */
+		if (!robust_move (fname, keep_name))
+			rprintf(FERROR, "keep_backup failed %s -> %s : %s\n",
+				fname, keep_name, strerror(errno));
+	} else {
+	/* this bit only used to "keep" empty directories */
+		/* make the parent directories */
+		make_dir (keep_name, 0755);
+		/* now make the (empty) directory */
+		do_mkdir (keep_name, file->mode);
+		if (verbose > 1)
+			rprintf (FINFO, "keep_backup: made empty dir: %s\n",
+				keep_name);
+	}
+
+	set_perms (keep_name, file, NULL, 0);
+	free_file (file);
+	free (file);
+	if (verbose > 1)
+		rprintf (FINFO, "keep_backup %s -> %s\n", fname, keep_name);
+	return 1;
+} /* keep_backup */
+
+
+/* main backup switch routine */
+int make_backup(char *fname)
+{
+	if (backup_dir)
+		return (keep_backup(fname));
+	else
+		return (make_simple_backup(fname));
+}
+