vcfgrestore: add prompt with active volumes

Add check for active device with names matching restored VG.
When such devices are present in dm table, prompt user, if he
wish to continue.

diff --git a/WHATS_NEW b/WHATS_NEW
index 70fb76ac733b4b68145b3a0c3a8a88e7b3845736..d90ff3ad68680b90976ffa230524390c9c26f673 100644 (file)
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 3.0.0
 =============
+  Enhance vgcfgrestore to check for active LVs in restored VG.
   Configure supports --disable-silent-rules for verbose builds.
   Fix unmonitoring of merging snapshots.
   Cache can uses metadata format 2 with cleaner policy.

diff --git a/tools/vgcfgrestore.c b/tools/vgcfgrestore.c
index 0b0368769c8714fba46eaa992bb5eed34b30d966..0dd7d4d771f85a374400898ff991fc160f3cbac8 100644 (file)
--- a/tools/vgcfgrestore.c
+++ b/tools/vgcfgrestore.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
- * Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004-2018 Red Hat, Inc. All rights reserved.
  *
  * This file is part of LVM2.
  *
@@ -15,11 +15,70 @@
 
 #include "tools.h"
 #include "daemons/lvmetad/lvmetad-client.h"
+#include "device_mapper/all.h"
+#include "device_mapper/misc/dm-ioctl.h"
+
+/*
+ * Check if there are any active volumes from restored vg_name.
+ * We can prompt user, as such operation may make some serious
+ * troubles later, when user will try to continue such devices.
+ */
+static int _check_all_dm_devices(const char *vg_name, unsigned *found)
+{
+       struct dm_task *dmt;
+       struct dm_names *names;
+       char vgname_buf[DM_NAME_LEN * 2];
+       char *vgname, *lvname, *lvlayer;
+       unsigned next = 0;
+       int r = 1;
+
+       if (!(dmt = dm_task_create(DM_DEVICE_LIST)))
+               return_0;
+
+       if (!dm_task_run(dmt)) {
+               r = 0;
+               goto_out;
+       }
+
+       if (!(names = dm_task_get_names(dmt))) {
+               r = 0;
+               goto_out;
+       }
+
+       if (!names->dev) {
+               log_verbose("No devices found.");
+               goto out;
+       }
+
+       do {
+               /* TODO: Do we want to validate UUID LVM- prefix as well ? */
+               names = (struct dm_names *)((char *) names + next);
+               if (!dm_strncpy(vgname_buf, names->name, sizeof(vgname_buf))) {
+                       r = 0;
+                       goto_out;
+               }
+               vgname = vgname_buf;
+               if (!dm_split_lvm_name(NULL, NULL, &vgname, &lvname, &lvlayer)) {
+                       r = 0;
+                       goto_out;
+               }
+               if (strcmp(vgname, vg_name) == 0) {
+                       log_print("Volume group %s has active volume: %s.", vgname, lvname);
+                       (*found)++;
+               }
+               next = names->next;
+       } while (next);
+
+out:
+       dm_task_destroy(dmt);
+       return r;
+}
 
 int vgcfgrestore(struct cmd_context *cmd, int argc, char **argv)
 {
        const char *vg_name = NULL;
        int lvmetad_rescan = 0;
+       unsigned found = 0;
        int ret;
 
        if (argc == 1) {
@@ -47,6 +106,21 @@ int vgcfgrestore(struct cmd_context *cmd, int argc, char **argv)
                return ECMD_PROCESSED;
        }
 
+       if (!_check_all_dm_devices(vg_name, &found)) {
+               log_warn("WARNING: Failed to check for active volumes in volume group \"%s\".", vg_name);
+       } else if (found) {
+               log_warn("WARNING: Found %u active volume(s) in volume group \"%s\".",
+                        found, vg_name);
+               log_print("Restoring VG with active LVs, may cause mismatch with its metadata.");
+               if (!arg_is_set(cmd, yes_ARG) &&
+                   yes_no_prompt("Do you really want to proceed with restore of volume group \"%s\", "
+                                 "while %u volume(s) are active? [y/n]: ",
+                                 vg_name, found) == 'n') {
+                       log_error("Restore aborted.");
+                       return ECMD_FAILED;
+               }
+       }
+
        /*
         * lvmetad does not handle a VG being restored, which would require
         * vg_remove of the existing VG, then vg_update of the restored VG.  A