FTL: Initialize nv_cache metadata on startup

Signed-off-by: Kozlowski Mateusz <mateusz.kozlowski@intel.com>
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Change-Id: Ie1a60ec8d1e05b1e4dec85a7187cffad24496460
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/13320
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

lib/ftl/ftl_nv_cache.c

@@ -325,6 +325,44 @@ chunk_free_p2l_map(struct ftl_nv_cache_chunk *chunk)
 	ftl_chunk_free_md_entry(chunk);
 }
 
+int
+ftl_nv_cache_save_state(struct ftl_nv_cache *nv_cache)
+{
+	struct spdk_ftl_dev *dev = SPDK_CONTAINEROF(nv_cache, struct spdk_ftl_dev, nv_cache);
+	struct ftl_nv_cache_chunk *chunk;
+	int status = 0;
+	uint64_t i;
+
+	assert(nv_cache->chunk_open_count == 0);
+
+	chunk = nv_cache->chunks;
+	if (!chunk) {
+		FTL_ERRLOG(dev, "Cannot save NV cache state, no NV cache metadata\n");
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < nv_cache->chunk_count; i++, chunk++) {
+		nvc_validate_md(nv_cache, chunk->md);
+
+		if (chunk->md->blocks_written == nv_cache->chunk_blocks) {
+			/* Full chunk */
+		} else if (0 == chunk->md->blocks_written) {
+			/* Empty chunk */
+		} else {
+			assert(0);
+			status = -EINVAL;
+			break;
+		}
+	}
+
+	if (status) {
+		FTL_ERRLOG(dev, "Cannot save NV cache state, inconsistent NV cache"
+			   "metadata\n");
+	}
+
+	return status;
+}
+
 static int
 chunk_alloc_p2l_map(struct ftl_nv_cache_chunk *chunk)
 {

lib/ftl/ftl_nv_cache.h

@@ -137,6 +137,8 @@ int ftl_nv_cache_read(struct ftl_io *io, ftl_addr addr, uint32_t num_blocks,
 bool ftl_nv_cache_full(struct ftl_nv_cache *nv_cache);
 void ftl_nv_cache_process(struct spdk_ftl_dev *dev);
 
+int ftl_nv_cache_save_state(struct ftl_nv_cache *nv_cache);
+
 void ftl_nv_cache_halt(struct ftl_nv_cache *nv_cache);
 
 int ftl_nv_cache_chunks_busy(struct ftl_nv_cache *nv_cache);

lib/ftl/mngt/ftl_mngt_md.c

@@ -120,6 +120,17 @@ persist(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt,
 	ftl_md_persist(md);
 }
 
+void
+ftl_mngt_persist_nv_cache_metadata(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt)
+{
+	if (ftl_nv_cache_save_state(&dev->nv_cache)) {
+		ftl_mngt_fail_step(mngt);
+		return;
+	}
+
+	persist(dev, mngt, FTL_LAYOUT_REGION_TYPE_NVC_MD);
+}
+
 static uint32_t
 get_sb_crc(struct ftl_superblock *sb)
 {

lib/ftl/mngt/ftl_mngt_startup.c

@@ -108,6 +108,10 @@ static const struct ftl_mngt_process_desc desc_first_start = {
 			.name = "Scrub NV cache",
 			.action = ftl_mngt_scrub_nv_cache,
 		},
+		{
+			.name = "Save initial chunk info metadata",
+			.action = ftl_mngt_persist_nv_cache_metadata,
+		},
 		{
 			.name = "Set FTL dirty state",
 			.action = ftl_mngt_set_dirty,

lib/ftl/mngt/ftl_mngt_steps.h

@@ -68,4 +68,6 @@ void ftl_mngt_init_default_sb(struct spdk_ftl_dev *dev, struct ftl_mngt_process
 
 void ftl_mngt_set_dirty(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt);
 
+void ftl_mngt_persist_nv_cache_metadata(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt);
+
 #endif /* FTL_MNGT_STEPS_H */