[lvm-devel] master - lvconvert: improve validation thin and cache pool conversion

[Zdenek Kabelac]

Gitweb:        https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=7612c21f5511c58bac81fc46e304bd9f4cd2cd75
Commit:        7612c21f5511c58bac81fc46e304bd9f4cd2cd75
Parent:        13fb57bbb1deca9ea14e58a3a4edf284d3f4846c
Author:        Zdenek Kabelac <zkabelac at redhat.com>
AuthorDate:    Fri Sep 6 18:09:40 2019 +0200
Committer:     Zdenek Kabelac <zkabelac at redhat.com>
CommitterDate: Tue Sep 17 13:13:49 2019 +0200

lvconvert: improve validation thin and cache pool conversion

Limit convertible LVs to thin-pool and cache-pools.
Also fix return code on  interal error path to return ECMD_FAILED.
---
 WHATS_NEW         |    1 +
 tools/lvconvert.c |   52 +++++++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/WHATS_NEW b/WHATS_NEW
index cb93bbe..518b944 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.03.06 - 
 ================================
+  Enhance validation for thin and cache pool conversion and swapping.
   Improve internal removal of cached devices.
   Synchronize with udev when dropping snapshot.
   Add missing device synchronization point before removing pvmove node.
diff --git a/tools/lvconvert.c b/tools/lvconvert.c
index 31f9296..d64ab22 100644
--- a/tools/lvconvert.c
+++ b/tools/lvconvert.c
@@ -4455,24 +4455,66 @@ static int _lvconvert_to_pool_or_swap_metadata_single(struct cmd_context *cmd,
 	struct dm_list *use_pvh = NULL;
 	int to_thinpool = 0;
 	int to_cachepool = 0;
+	int lvt_enum = get_lvt_enum(lv);
+	struct lv_type *lvtype;
 
 	switch (cmd->command->command_enum) {
 	case lvconvert_to_thinpool_or_swap_metadata_CMD:
+		if (lv_is_cache(lv))
+			/* For cached LV check the cache origin LV type */
+			lvt_enum = get_lvt_enum(seg_lv(first_seg(lv), 0));
 		to_thinpool = 1;
 		break;
 	case lvconvert_to_cachepool_or_swap_metadata_CMD:
+		if (lv_is_cache(lv))
+			goto_bad; /* Cache over cache is not supported */
 		to_cachepool = 1;
 		break;
 	default:
-		log_error(INTERNAL_ERROR "Invalid lvconvert pool command");
-		return 0;
-	};
+		log_error(INTERNAL_ERROR "Invalid lvconvert pool command.");
+		return ECMD_FAILED;
+	}
+
+	switch (lvt_enum) {
+	case thinpool_LVT:
+		if (!to_thinpool)
+			goto_bad; /* can't accept cache-pool */
+		break; /* swap thin-pool */
+	case cachepool_LVT:
+		if (!to_cachepool)
+			goto_bad; /* can't accept thin-pool */
+		break; /* swap cache-pool */
+	case linear_LVT:
+	case raid_LVT:
+	case striped_LVT:
+	case zero_LVT:
+		break;
+	default:
+bad:
+		lvtype = get_lv_type(lvt_enum);
+		log_error("LV %s with type %s cannot be used as a %s pool LV.",
+			  display_lvname(lv), lvtype ? lvtype->name : "unknown",
+			  to_thinpool ? "thin" : "cache");
+		return ECMD_FAILED;
+	}
 
 	if (lv_is_origin(lv)) {
 		log_error("Cannot convert logical volume %s under snapshot.",
 			  display_lvname(lv));
-		return 0;
-	};
+		return ECMD_FAILED;
+	}
+
+	if (!lv_is_visible(lv)) {
+		log_error("Can't convert internal LV %s.",
+			  display_lvname(lv));
+		return ECMD_FAILED;
+	}
+
+	if (lv_is_locked(lv)) {
+		log_error("Can't convert locked LV %s.",
+			  display_lvname(lv));
+		return ECMD_FAILED;
+	}
 
 	if (cmd->position_argc > 1) {
 		/* First pos arg is required LV, remaining are optional PVs. */