lightnvm: pblk: allocate line map bitmaps using a mempool

Line map bitmap allocations are fairly large and can fail. Allocation
failures are fatal to pblk, stopping the write pipeline. To avoid this,
allocate the bitmaps using a mempool instead.

Mempool allocations never fail if called from a process context,
and pblk *should* only allocate map bitmaps in process context,
but keep the failure handling for robustness sake.

Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 8adc8ac8b03c..76a4a271b9cf 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -498,6 +498,9 @@ static void pblk_line_mg_free(struct pblk *pblk)
 		pblk_mfree(l_mg->eline_meta[i]->buf, l_mg->emeta_alloc_type);
 		kfree(l_mg->eline_meta[i]);
 	}
+
+	mempool_destroy(l_mg->bitmap_pool);
+	kmem_cache_destroy(l_mg->bitmap_cache);
 }
 
 static void pblk_line_meta_free(struct pblk_line_mgmt *l_mg,
@@ -797,6 +800,17 @@ static int pblk_line_mg_init(struct pblk *pblk)
 			goto fail_free_smeta;
 	}
 
+	l_mg->bitmap_cache = kmem_cache_create("pblk_lm_bitmap",
+			lm->sec_bitmap_len, 0, 0, NULL);
+	if (!l_mg->bitmap_cache)
+		goto fail_free_smeta;
+
+	/* the bitmap pool is used for both valid and map bitmaps */
+	l_mg->bitmap_pool = mempool_create_slab_pool(PBLK_DATA_LINES * 2,
+				l_mg->bitmap_cache);
+	if (!l_mg->bitmap_pool)
+		goto fail_destroy_bitmap_cache;
+
 	/* emeta allocates three different buffers for managing metadata with
 	 * in-memory and in-media layouts
 	 */
@@ -849,6 +863,10 @@ fail_free_emeta:
 			kfree(l_mg->eline_meta[i]->buf);
 		kfree(l_mg->eline_meta[i]);
 	}
+
+	mempool_destroy(l_mg->bitmap_pool);
+fail_destroy_bitmap_cache:
+	kmem_cache_destroy(l_mg->bitmap_cache);
 fail_free_smeta:
 	for (i = 0; i < PBLK_DATA_LINES; i++)
 		kfree(l_mg->sline_meta[i]);