o High level archiving and backup functions.

I've split the old autobackup function into two seperate areas:

'archiving' is performed *before* a vg configuration is changed.  This
produces a numbered backup in /etc/lvm/archive.

A 'backup' is performed *after* a vg change.  So the directory /etc/lvm/backup
will hold the  a copy of the current configuration.

tools/archive.c

@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "archive.h"
+#include "dbg_malloc.h"
+
+static struct {
+	int enabled;
+	char *dir;
+	unsigned int keep_days;
+	unsigned int keep_number;
+
+} _archive_params;
+
+int archive_init(const char *dir,
+		 unsigned int keep_days, unsigned int keep_min)
+{
+	if (!(_archive_params.dir = dbg_strdup(dir))) {
+		log_err("Couldn't create copy of archive dir.");
+		return 0;
+	}
+
+	_archive_params.keep_days = keep_days;
+	_archive_params.keep_number = keep_number;
+	_archive_params.enabled = 1;
+	return 1;
+}
+
+void archive_exit(void)
+{
+	dbg_free(_archive_params.dir);
+	memset(&_archive_params, 0, sizeof(_archive_params));
+}
+
+void archive_disable(void)
+{
+	_archive_params.enabled = 0;
+}
+
+void archive_enable(void)
+{
+	_archive_params.enabled = 1;
+}
+
+static int __archive(struct volume_group *vg)
+{
+	int r;
+	struct format_instance *archiver;
+
+	if (!(archiver = backup_format_create(vg->cmd,
+					      _archive_params.dir,
+					      _archive_params.keep_days,
+					      _archive_params.keep_number))) {
+		log_error("Couldn't create archiver object.");
+		return 0;
+	}
+
+	if (!(r = archiver->ops->vg_write(archiver, vg)))
+		stack;
+
+	archiver->ops->destroy(archiver);
+	return r;
+}
+
+int archive(struct volume_group *vg)
+{
+	if (!_archive_params.enabled)
+		return 1;
+
+	if (test_mode()) {
+		log_print("Test mode: Skipping archiving of volume group.");
+		return 1;
+	}
+
+	log_print("Creating archive of volume group '%s' ...", vg->name);
+	if (!__archive(vg)) {
+		log_error("Archiving failed.");
+		return 0;
+	}
+
+	return 1;
+}
+
+
+
+static struct {
+	int enabled;
+	char *dir;
+
+} _backup_params;
+
+int backup_init(const char *dir)
+{
+	if (!(_backup_params.dir = dbg_strdup(dir))) {
+		log_err("Couldn't create copy of backup dir.");
+		return 0;
+	}
+
+	return 1;
+}
+
+void backup_exit(void)
+{
+	dbg_free(_backup_params.dir);
+	memset(&backup_params, 0, sizeof(_backup_params));
+}
+
+static int __backup(struct volume_group *vg)
+{
+	int r;
+	struct format_instance *tf;
+	char name[PATH_MAX];
+
+	if (lvm_snprintf(name, sizeof(name), "%s/%s",
+			 _backup_params.dir, vg->name) < 0) {
+		log_err("Couldn't generate backup filename for volume group.");
+		return 0;
+	}
+
+	if (!(tf = text_format_create(vg->cmd, name))) {
+		log_error("Couldn't create backup object.");
+		return 0;
+	}
+
+	if (!(r = tf->ops->vg_write(tf, vg)))
+		stack;
+
+	tf->ops->destroy(tf);
+	return r;
+}
+
+int backup(struct volume_group *vg)
+{
+	if (!_backup_params.enabled)
+		return 1;
+
+	if (test_mode()) {
+		log_print("Test mode: Skipping volume group backup.");
+		return 1;
+	}
+
+	log_print("Creating backup of volume group '%s' ...", vg->name);
+
+	if (!__backup(vg)) {
+		log_error("Backup failed.");
+		return 0;
+	}
+
+	return 1;
+}

tools/archive.h

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef _LVM_TOOL_ARCHIVE_H
+#define _LVM_TOOL_ARCHIVE_H
+
+/*
+ * There are two operations that come under the
+ * general area of backups.  'Archiving' occurs just
+ * before a volume group configuration is changed.
+ * The user may configure when archived files are expired.
+ * Typically archives will be stored in /etc/lvm/archive.
+ *
+ * A 'backup' is a redundant copy of the *current*
+ * volume group configuration.  As such it should
+ * be taken just after the volume group is
+ * changed.  Only 1 backup file will exist.
+ * Typically backups will be stored in /etc/lvm/backups.
+ */
+
+int archive_init(const char *dir,
+		 unsigned int keep_days, unsigned int keep_min);
+void archive_exit(void);
+
+void archive_disable(void);
+void archive_enable(void);
+int archive(struct volume_group *vg);
+
+int backup_init(const char *dir);
+void backup_exit(void);
+
+void backup_enable(void);
+void backup_disable(void);
+int backup(struct volume_group *vg);
+
+#endif