lightnvm: pblk: support packed metadata

pblk performs recovery of open lines by storing the LBA in the per LBA
metadata field. Recovery therefore only works for drives that has this
field.

This patch adds support for packed metadata, which store l2p mapping
for open lines in last sector of every write unit and enables drives
without per IO metadata to recover open lines.

After this patch, drives with OOB size <16B will use packed metadata
and metadata size larger than16B will continue to use the device per
IO metadata.

Reviewed-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 44 insertions, 4 deletions

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 7e3397f8ead1..1ff165351180 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -376,7 +376,7 @@ void pblk_write_should_kick(struct pblk *pblk)
 {
 	unsigned int secs_avail = pblk_rb_read_count(&pblk->rwb);
 
-	if (secs_avail >= pblk->min_write_pgs)
+	if (secs_avail >= pblk->min_write_pgs_data)
 		pblk_write_kick(pblk);
 }
 
@@ -407,7 +407,9 @@ struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
 	struct pblk_line_meta *lm = &pblk->lm;
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct list_head *move_list = NULL;
-	int vsc = le32_to_cpu(*line->vsc);
+	int packed_meta = (le32_to_cpu(*line->vsc) / pblk->min_write_pgs_data)
+			* (pblk->min_write_pgs - pblk->min_write_pgs_data);
+	int vsc = le32_to_cpu(*line->vsc) + packed_meta;
 
 	lockdep_assert_held(&line->lock);
 
@@ -620,12 +622,15 @@ out:
 }
 
 int pblk_calc_secs(struct pblk *pblk, unsigned long secs_avail,
-		   unsigned long secs_to_flush)
+		   unsigned long secs_to_flush, bool skip_meta)
 {
 	int max = pblk->sec_per_write;
 	int min = pblk->min_write_pgs;
 	int secs_to_sync = 0;
 
+	if (skip_meta && pblk->min_write_pgs_data != pblk->min_write_pgs)
+		min = max = pblk->min_write_pgs_data;
+
 	if (secs_avail >= max)
 		secs_to_sync = max;
 	else if (secs_avail >= min)
@@ -852,7 +857,7 @@ int pblk_line_emeta_read(struct pblk *pblk, struct pblk_line *line,
 next_rq:
 	memset(&rqd, 0, sizeof(struct nvm_rq));
 
-	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
+	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0, false);
 	rq_len = rq_ppas * geo->csecs;
 
 	bio = pblk_bio_map_addr(pblk, emeta_buf, rq_ppas, rq_len,
@@ -2169,3 +2174,38 @@ void pblk_lookup_l2p_rand(struct pblk *pblk, struct ppa_addr *ppas,
 	}
 	spin_unlock(&pblk->trans_lock);
 }
+
+void *pblk_get_meta_for_writes(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	void *buffer;
+
+	if (pblk_is_oob_meta_supported(pblk)) {
+		/* Just use OOB metadata buffer as always */
+		buffer = rqd->meta_list;
+	} else {
+		/* We need to reuse last page of request (packed metadata)
+		 * in similar way as traditional oob metadata
+		 */
+		buffer = page_to_virt(
+			rqd->bio->bi_io_vec[rqd->bio->bi_vcnt - 1].bv_page);
+	}
+
+	return buffer;
+}
+
+void pblk_get_packed_meta(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	void *meta_list = rqd->meta_list;
+	void *page;
+	int i = 0;
+
+	if (pblk_is_oob_meta_supported(pblk))
+		return;
+
+	page = page_to_virt(rqd->bio->bi_io_vec[rqd->bio->bi_vcnt - 1].bv_page);
+	/* We need to fill oob meta buffer with data from packed metadata */
+	for (; i < rqd->nr_ppas; i++)
+		memcpy(pblk_get_meta(pblk, meta_list, i),
+			page + (i * sizeof(struct pblk_sec_meta)),
+			sizeof(struct pblk_sec_meta));
+}