cache: enhance removal function to work with cvol

To keep things simple, use same code for all cache removal functions,
not just for cachepools but also cachevols.

diff --git a/lib/metadata/cache_manip.c b/lib/metadata/cache_manip.c
index 1a5482b10b0526408162b2e80fc03cb77fe1f449..9ace49431cdcdd7c96a4efa78f0c147345490574 100644 (file)
--- a/lib/metadata/cache_manip.c
+++ b/lib/metadata/cache_manip.c
@@ -747,7 +747,7 @@ int lv_detach_cache_vol(struct logical_volume *cache_lv, int noflush)
  * @cache_lv
  *
  * Given a cache LV, remove the cache layer.  This will unlink
- * the origin and cache_pool, remove the cache LV layer, and promote
+ * the origin and cache_pool/cachevol, remove the cache LV layer, and promote
  * the origin to a usable non-cached LV of the same name as the
  * given cache_lv.
  *
@@ -758,6 +758,8 @@ int lv_cache_remove(struct logical_volume *cache_lv)
        struct lv_segment *cache_seg = first_seg(cache_lv);
        struct logical_volume *corigin_lv;
        struct logical_volume *cache_pool_lv;
+       const struct id *data_id, *metadata_id;
+       uint64_t data_len, metadata_len;
        cache_mode_t cache_mode;
        int is_clear;
 
@@ -767,11 +769,6 @@ int lv_cache_remove(struct logical_volume *cache_lv)
                return 0;
        }
 
-       if (lv_is_cache_vol(cache_seg->pool_lv)) {
-               log_error(INTERNAL_ERROR "Incorrect remove for cache single");
-               return 0;
-       }
-
        if (lv_is_pending_delete(cache_lv)) {
                log_debug(INTERNAL_ERROR "LV %s is already dropped cache volume.",
                          display_lvname(cache_lv));
@@ -849,6 +846,13 @@ int lv_cache_remove(struct logical_volume *cache_lv)
        if (!remove_layer_from_lv(cache_lv, corigin_lv))
                return_0;
 
+       /* Preserve currently imortant data from original cache segment.
+        * TODO: can it be done without this ? */
+       data_id = &cache_seg->data_id;
+       data_len = cache_seg->data_len;
+       metadata_id = &cache_seg->metadata_id;
+       metadata_len = cache_seg->metadata_len;
+
        /* Replace 'error' with 'cache' segtype */
        cache_seg = first_seg(corigin_lv);
        if (!(cache_seg->segtype = get_segtype_from_string(corigin_lv->vg->cmd, SEG_TYPE_NAME_CACHE)))
@@ -864,6 +868,18 @@ int lv_cache_remove(struct logical_volume *cache_lv)
        corigin_lv->size = cache_lv->size;
        corigin_lv->status |= LV_PENDING_DELETE;
 
+       /* Restore preserved data into a new cache segment that is going to be removed. */
+       if ((cache_seg->data_len = data_len)) {
+               cache_seg->metadata_len = metadata_len;
+               memcpy(&cache_seg->data_id, data_id, sizeof(struct id));
+               memcpy(&cache_seg->metadata_id, metadata_id, sizeof(struct id));
+               cache_pool_lv->status |= LV_CACHE_VOL;
+               /* Unused settings set only for passing metadata validation. */
+               cache_seg->cache_mode = CACHE_MODE_WRITETHROUGH;
+               cache_seg->chunk_size = DM_CACHE_MAX_DATA_BLOCK_SIZE;
+               cache_seg->cache_metadata_format = CACHE_METADATA_FORMAT_2;
+       }
+
        /* Reattach cache pool */
        if (!attach_pool_lv(cache_seg, cache_pool_lv, NULL, NULL, NULL))
                return_0;
@@ -879,6 +895,8 @@ remove:
        if (!lv_remove(cache_lv)) /* Will use LV_PENDING_DELETE */
                return_0;
 
+       /* CachePool or CacheVol is left inactivate for further manipulation */
+
        return 1;
 }