blobstore: Change behaviour of dirty bit

The patch disables writing dirty bit during blobstore loading.
Instead, dirty bit is written prior to the first metadata update.

Signed-off-by: Piotr Pelplinski <piotr.pelplinski@intel.com>
Change-Id: I7be81009a99f09048bf23749c8f6ef5e9f7b3751

Reviewed-on: https://review.gerrithub.io/410884
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Maciej Szwed <maciej.szwed@intel.com>

lib/blob/blobstore.c

@@ -953,6 +953,8 @@ _spdk_blob_load(spdk_bs_sequence_t *seq, struct spdk_blob *blob,
 struct spdk_blob_persist_ctx {
 	struct spdk_blob		*blob;
 
+	struct spdk_bs_super_block	*super;
+
 	struct spdk_blob_md_page	*pages;
 
 	uint64_t			idx;
@@ -1341,6 +1343,34 @@ _spdk_blob_persist_start(struct spdk_blob_persist_ctx *ctx)
 	_spdk_blob_persist_write_page_chain(seq, ctx, 0);
 }
 
+static void
+_spdk_blob_persist_dirty_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
+{
+	struct spdk_blob_persist_ctx *ctx = cb_arg;
+
+	ctx->blob->bs->clean = 0;
+
+	spdk_dma_free(ctx->super);
+
+	_spdk_blob_persist_start(ctx);
+}
+
+static void
+_spdk_bs_write_super(spdk_bs_sequence_t *seq, struct spdk_blob_store *bs,
+		     struct spdk_bs_super_block *super, spdk_bs_sequence_cpl cb_fn, void *cb_arg);
+
+
+static void
+_spdk_blob_persist_dirty(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
+{
+	struct spdk_blob_persist_ctx *ctx = cb_arg;
+
+	ctx->super->clean = 0;
+
+	_spdk_bs_write_super(seq, ctx->blob->bs, ctx->super, _spdk_blob_persist_dirty_cpl, ctx);
+}
+
+
 /* Write a blob to disk */
 static void
 _spdk_blob_persist(spdk_bs_sequence_t *seq, struct spdk_blob *blob,
@@ -1365,7 +1395,20 @@ _spdk_blob_persist(spdk_bs_sequence_t *seq, struct spdk_blob *blob,
 	ctx->cb_fn = cb_fn;
 	ctx->cb_arg = cb_arg;
 
-	_spdk_blob_persist_start(ctx);
+	if (blob->bs->clean) {
+		ctx->super = spdk_dma_zmalloc(sizeof(*ctx->super), 0x1000, NULL);
+		if (!ctx->super) {
+			cb_fn(seq, cb_arg, -ENOMEM);
+			free(ctx);
+			return;
+		}
+
+		spdk_bs_sequence_read_dev(seq, ctx->super, _spdk_bs_page_to_lba(blob->bs, 0),
+					  _spdk_bs_byte_to_lba(blob->bs, sizeof(*ctx->super)),
+					  _spdk_blob_persist_dirty, ctx);
+	} else {
+		_spdk_blob_persist_start(ctx);
+	}
 }
 
 struct spdk_blob_copy_cluster_ctx {
@@ -2618,7 +2661,7 @@ _spdk_bs_load_used_pages_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
 }
 
 static void
-_spdk_bs_load_write_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
+_spdk_bs_load_read_used_pages(spdk_bs_sequence_t *seq, void *cb_arg)
 {
 	struct spdk_bs_load_ctx	*ctx = cb_arg;
 	uint64_t lba, lba_count, mask_size;
@@ -2906,6 +2949,7 @@ _spdk_bs_load_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
 	}
 
 	/* Parse the super block */
+	ctx->bs->clean = 1;
 	ctx->bs->cluster_sz = ctx->super->cluster_size;
 	ctx->bs->total_clusters = ctx->bs->dev->blockcnt / (ctx->bs->cluster_sz / ctx->bs->dev->blocklen);
 	ctx->bs->pages_per_cluster = ctx->bs->cluster_sz / SPDK_BS_PAGE_SIZE;
@@ -2925,10 +2969,10 @@ _spdk_bs_load_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
 		 *  using _spdk_bs_recover.
 		 */
 		ctx->super->clean = 0;
+		ctx->bs->clean = 0;
 		_spdk_bs_write_super(seq, ctx->bs, ctx->super, _spdk_bs_recover, ctx);
 	} else {
-		ctx->super->clean = 0;
+		_spdk_bs_load_read_used_pages(seq, ctx);
-		_spdk_bs_write_super(seq, ctx->bs, ctx->super, _spdk_bs_load_write_super_cpl, ctx);
 	}
 }
 

lib/blob/blobstore.h

@@ -180,6 +180,8 @@ struct spdk_blob_store {
 
 	TAILQ_HEAD(, spdk_blob)		blobs;
 	TAILQ_HEAD(, spdk_blob_list)	snapshots;
+
+	bool                            clean;
 };
 
 struct spdk_bs_channel {

test/unit/lib/blob/blob.c/blob_ut.c

@@ -1863,13 +1863,17 @@ bs_load(void)
 	SPDK_CU_ASSERT_FATAL(g_bs != NULL);
 
 	super_block = (struct spdk_bs_super_block *)g_dev_buffer;
-	CU_ASSERT(super_block->clean == 0);
+	CU_ASSERT(super_block->clean == 1);
 
 	spdk_bs_open_blob(g_bs, blobid, blob_op_with_handle_complete, NULL);
 	CU_ASSERT(g_bserrno == 0);
 	CU_ASSERT(g_blob != NULL);
 	blob = g_blob;
 
+	/* Verify that blobstore is marked dirty after first metadata sync */
+	spdk_blob_sync_md(blob, blob_op_complete, NULL);
+	CU_ASSERT(super_block->clean == 1);
+
 	/* Get the xattrs */
 	value = NULL;
 	rc = spdk_blob_get_xattr_value(blob, "length", &value, &value_len);