report: report dead LV names with '-' prefix

All names for dead LVs are prefixed with '-' character to make a clear
difference between live and dead LVs. The '-' can't be set by users as
LV names directly hence we never get into a conflict with the names that
user defines for live LVs.

For example:
$ lvs -r -o name,name_removed,lv_attr vg/-rlvol0
  LV     RLV     Attr
  -lvol2 -rlvol0 ----r-----

1 files changed, 39 insertions, 11 deletions

diff --git a/lib/report/report.c b/lib/report/report.c
index 2b0045f1d..8211bf3aa 100644
--- a/lib/report/report.c
+++ b/lib/report/report.c
@@ -1663,33 +1663,47 @@ static int _segtype_disp(struct dm_report *rh __attribute__((unused)),
 	return _field_set_value(field, name, NULL);
 }
 
-static int _lvname_disp(struct dm_report *rh, struct dm_pool *mem,
-			struct dm_report_field *field,
-			const void *data, void *private)
+static int _do_lvname_disp(struct dm_report *rh, struct dm_pool *mem,
+			   struct dm_report_field *field,
+			   const void *data, void *private,
+			   int prefer_dname)
 {
 	struct cmd_context *cmd = (struct cmd_context *) private;
 	const struct logical_volume *lv = (const struct logical_volume *) data;
+	int is_dead = lv_is_dead(lv);
+	const char *tmp_lvname;
 	char *repstr, *lvname;
 	size_t len;
 
-	if (lv_is_dead(lv))
-		return _string_disp(rh, mem, field, &lv->this_glv->dead->name, private);
-
-	if (lv_is_visible(lv) || !cmd->report_mark_hidden_devices)
+	if (!is_dead && (lv_is_visible(lv) || !cmd->report_mark_hidden_devices))
 		return _string_disp(rh, mem, field, &lv->name, private);
 
-	len = strlen(lv->name) + 3;
+	if (is_dead)
+		tmp_lvname = prefer_dname ? lv->this_glv->dead->dname
+					  : lv->this_glv->dead->name;
+	else
+		tmp_lvname = lv->name;
+
+	if (is_dead)
+		len = strlen(tmp_lvname) + strlen(DEAD_LV_PREFIX) + 1;
+	else
+		len = strlen(tmp_lvname) + 3;
 	if (!(repstr = dm_pool_zalloc(mem, len))) {
 		log_error("dm_pool_alloc failed");
 		return 0;
 	}
 
-	if (dm_snprintf(repstr, len, "[%s]", lv->name) < 0) {
+	if (dm_snprintf(repstr, len, "%s%s%s",
+			is_dead ? DEAD_LV_PREFIX : "[",
+			tmp_lvname,
+			is_dead ? "" : "]") < 0) {
 		log_error("lvname snprintf failed");
 		return 0;
 	}
 
-	if (!(lvname = dm_pool_strdup(mem, lv->name))) {
+	if (is_dead)
+		lvname = repstr;
+	else if (!(lvname = dm_pool_strdup(mem, tmp_lvname))) {
 		log_error("dm_pool_strdup failed");
 		return 0;
 	}
@@ -1697,6 +1711,20 @@ static int _lvname_disp(struct dm_report *rh, struct dm_pool *mem,
 	return _field_set_value(field, repstr, lvname);
 }
 
+static int _lvname_disp(struct dm_report *rh, struct dm_pool *mem,
+			struct dm_report_field *field,
+			const void *data, void *private)
+{
+	return _do_lvname_disp(rh, mem, field, data, private, 0);
+}
+
+static int _lvrname_disp(struct dm_report *rh, struct dm_pool *mem,
+			 struct dm_report_field *field,
+			 const void *data, void *private)
+{
+	return _do_lvname_disp(rh, mem, field, data, private, 1);
+}
+
 static int _do_loglv_disp(struct dm_report *rh, struct dm_pool *mem,
 			  struct dm_report_field *field,
 			  const void *data, void *private,
@@ -1738,7 +1766,7 @@ static int _lvnameremoved_disp(struct dm_report *rh, struct dm_pool *mem,
 	if (!lv_is_dead(lv))
 		return _string_disp(rh, mem, field, &blank_name, private);
 
-	return _lvname_disp(rh, mem, field, &lv->this_glv->dead->dname, private);
+	return _lvrname_disp(rh, mem, field, lv, private);
 }
 
 static int _lvfullname_disp(struct dm_report *rh, struct dm_pool *mem,