lib/ftl: Keep DMA buffer for metadata as part of ftl_md structure

This patch is starting point for metadata refactor
which is needed for efficient ANM events support.

Change-Id: I81d864605e69008d8e3922fb61adf504187447a1
Signed-off-by: Wojciech Malikowski <wojciech.malikowski@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/449328
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

lib/ftl/ftl_band.c

@@ -174,7 +174,9 @@ ftl_band_free_md(struct ftl_band *band)
 	}
 
 	spdk_mempool_put(dev->lba_pool, md->lba_map);
+	spdk_dma_free(md->dma_buf);
 	md->lba_map = NULL;
+	md->dma_buf = NULL;
 }
 
 static void
@@ -660,6 +662,13 @@ ftl_band_alloc_md(struct ftl_band *band)
 		return -1;
 	}
 
+	md->dma_buf = spdk_dma_zmalloc(ftl_tail_md_num_lbks(dev) * FTL_BLOCK_SIZE,
+				       FTL_BLOCK_SIZE, NULL);
+	if (!md->dma_buf) {
+		spdk_mempool_put(dev->lba_pool, md->lba_map);
+		return -1;
+	}
+
 	ftl_band_acquire_md(band);
 	return 0;
 }

lib/ftl/ftl_band.h

@@ -100,8 +100,11 @@ struct ftl_md {
 	/* Bitmap of valid LBAs */
 	struct spdk_bit_array			*vld_map;
 
-	/* LBA map (only valid for open bands) */
+	/* LBA map (only valid for open/relocating bands) */
 	uint64_t				*lba_map;
+
+	/* Metadata DMA buffer (only valid for open/relocating bands) */
+	void					*dma_buf;
 };
 
 enum ftl_band_state {

lib/ftl/ftl_core.c

@@ -66,9 +66,6 @@ struct ftl_wptr {
 	/* Current erase block */
 	struct ftl_chunk		*chunk;
 
-	/* Metadata DMA buffer */
-	void				*md_buf;
-
 	/* List link */
 	LIST_ENTRY(ftl_wptr)		list_entry;
 };
@@ -114,7 +111,6 @@ ftl_wptr_free(struct ftl_wptr *wptr)
 		return;
 	}
 
-	spdk_dma_free(wptr->md_buf);
 	free(wptr);
 }
 
@@ -253,7 +249,7 @@ ftl_wptr_close_band(struct ftl_wptr *wptr)
 	ftl_band_set_state(band, FTL_BAND_STATE_CLOSING);
 	band->tail_md_ppa = wptr->ppa;
 
-	return ftl_band_write_tail_md(band, wptr->md_buf, ftl_md_write_cb);
+	return ftl_band_write_tail_md(band, band->md.dma_buf, ftl_md_write_cb);
 }
 
 static int
@@ -269,7 +265,7 @@ ftl_wptr_open_band(struct ftl_wptr *wptr)
 	assert(band->state == FTL_BAND_STATE_PREP);
 	ftl_band_set_state(band, FTL_BAND_STATE_OPENING);
 
-	return ftl_band_write_head_md(band, wptr->md_buf, ftl_md_write_cb);
+	return ftl_band_write_head_md(band, band->md.dma_buf, ftl_md_write_cb);
 }
 
 static int
@@ -390,13 +386,6 @@ ftl_wptr_init(struct ftl_band *band)
 		return NULL;
 	}
 
-	wptr->md_buf = spdk_dma_zmalloc(ftl_tail_md_num_lbks(dev) * FTL_BLOCK_SIZE,
-					FTL_BLOCK_SIZE, NULL);
-	if (!wptr->md_buf) {
-		ftl_wptr_free(wptr);
-		return NULL;
-	}
-
 	wptr->dev = dev;
 	wptr->band = band;
 	wptr->chunk = CIRCLEQ_FIRST(&band->chunks);

lib/ftl/ftl_reloc.c

@@ -77,9 +77,6 @@ struct ftl_band_reloc {
 	struct spdk_ring			*write_queue;
 
 	TAILQ_ENTRY(ftl_band_reloc)		entry;
-
-	/* TODO: get rid of md_buf */
-	void					*md_buf;
 };
 
 struct ftl_reloc {
@@ -172,7 +169,6 @@ ftl_reloc_read_lba_map_cb(void *arg, int status)
 	struct ftl_band_reloc *breloc = ftl_io_get_band_reloc(io);
 
 	assert(status == 0);
-	spdk_dma_free(breloc->md_buf);
 	ftl_io_free(io);
 	_ftl_reloc_prep(breloc);
 }
@@ -189,17 +185,11 @@ ftl_reloc_read_lba_map(struct ftl_band_reloc *breloc)
 	io->cb.ctx = io;
 	io->cb.fn = ftl_reloc_read_lba_map_cb;
 
-	breloc->md_buf = spdk_dma_zmalloc(ftl_lba_map_num_lbks(dev) * FTL_BLOCK_SIZE,
-					  FTL_BLOCK_SIZE, NULL);
-	if (!breloc->md_buf) {
-		return -1;
-	}
-
 	if (ftl_band_alloc_md(band)) {
 		assert(false);
 	}
 
-	return ftl_band_read_lba_map(band, &band->md, breloc->md_buf, &io->cb);
+	return ftl_band_read_lba_map(band, &band->md, band->md.dma_buf, &io->cb);
 }
 
 static void

test/unit/lib/ftl/common/utils.c

@@ -133,6 +133,7 @@ test_free_ftl_band(struct ftl_band *band)
 	spdk_bit_array_free(&band->md.vld_map);
 	free(band->chunk_buf);
 	free(band->md.lba_map);
+	spdk_dma_free(band->md.dma_buf);
 }
 
 uint64_t

test/unit/lib/ftl/ftl_md/ftl_md_ut.c

@@ -63,7 +63,7 @@ setup_band(struct ftl_band **band, const struct spdk_ocssd_geometry_data *geo,
 	dev = test_init_ftl_dev(geo, range);
 	*band = test_init_ftl_band(dev, 0);
 	rc = ftl_band_alloc_md(*band);
-	CU_ASSERT_EQUAL_FATAL(rc, 0);
+	SPDK_CU_ASSERT_FATAL(rc == 0);
 	ftl_band_clear_md(*band);
 }