From: =?UTF-8?q?Javier=20Gonz=C3=A1lez?= <javier@cnexlabs.com>
Date: Fri, 13 Oct 2017 14:46:06 +0200
Subject: [PATCH] lightnvm: pblk: fix min size for page mempool
Git-commit: bd432417681a224d9fa4a9d43be7d4edc82135b2
Patch-mainline: v4.15-rc1
References: bsc#1104967,FATE#325924
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

pblk uses an internal page mempool for allocating pages on internal
bios. The main two users of this memory pool are partial reads (reads
with some sectors in cache and some on media) and padded writes, which
need to add dummy pages to an existing bio already containing valid
data (and with a large enough bioset allocated). In both cases, the
maximum number of pages per bio is defined by the maximum number of
physical sectors supported by the underlying device.

This patch fixes a bad mempool allocation, where the min_nr of elements
on the pool was fixed (to 16), which is lower than the maximum number
of sectors supported by NVMe (as of the time for this patch). Instead,
use the maximum number of allowed sectors reported by the device.

Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/lightnvm/pblk-core.c |  6 +++---
 drivers/lightnvm/pblk-init.c | 15 ++++++++-------
 drivers/lightnvm/pblk-read.c |  2 +-
 drivers/lightnvm/pblk.h      |  2 +-
 4 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 9299a5a75a18..f5fbb9a46784 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -192,7 +192,7 @@ void pblk_bio_free_pages(struct pblk *pblk, struct bio *bio, int off,
 
 	for (i = off; i < nr_pages + off; i++) {
 		bv = bio->bi_io_vec[i];
-		mempool_free(bv.bv_page, pblk->page_pool);
+		mempool_free(bv.bv_page, pblk->page_bio_pool);
 	}
 }
 
@@ -204,14 +204,14 @@ int pblk_bio_add_pages(struct pblk *pblk, struct bio *bio, gfp_t flags,
 	int i, ret;
 
 	for (i = 0; i < nr_pages; i++) {
-		page = mempool_alloc(pblk->page_pool, flags);
+		page = mempool_alloc(pblk->page_bio_pool, flags);
 		if (!page)
 			goto err;
 
 		ret = bio_add_pc_page(q, bio, page, PBLK_EXPOSED_PAGE_SIZE, 0);
 		if (ret != PBLK_EXPOSED_PAGE_SIZE) {
 			pr_err("pblk: could not add page to bio\n");
-			mempool_free(page, pblk->page_pool);
+			mempool_free(page, pblk->page_bio_pool);
 			goto err;
 		}
 	}
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index eee4eeb47d07..7b1f29c71338 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -132,7 +132,6 @@ static int pblk_rwb_init(struct pblk *pblk)
 }
 
 /* Minimum pages needed within a lun */
-#define PAGE_POOL_SIZE 16
 #define ADDR_POOL_SIZE 64
 
 static int pblk_set_ppaf(struct pblk *pblk)
@@ -247,14 +246,16 @@ static int pblk_core_init(struct pblk *pblk)
 	if (pblk_init_global_caches(pblk))
 		return -ENOMEM;
 
-	pblk->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
-	if (!pblk->page_pool)
+	/* internal bios can be at most the sectors signaled by the device. */
+	pblk->page_bio_pool = mempool_create_page_pool(nvm_max_phys_sects(dev),
+									0);
+	if (!pblk->page_bio_pool)
 		return -ENOMEM;
 
 	pblk->line_ws_pool = mempool_create_slab_pool(PBLK_WS_POOL_SIZE,
 							pblk_blk_ws_cache);
 	if (!pblk->line_ws_pool)
-		goto free_page_pool;
+		goto free_page_bio_pool;
 
 	pblk->rec_pool = mempool_create_slab_pool(geo->nr_luns, pblk_rec_cache);
 	if (!pblk->rec_pool)
@@ -309,8 +310,8 @@ static int pblk_core_init(struct pblk *pblk)
 	mempool_destroy(pblk->rec_pool);
 free_blk_ws_pool:
 	mempool_destroy(pblk->line_ws_pool);
-free_page_pool:
-	mempool_destroy(pblk->page_pool);
+free_page_bio_pool:
+	mempool_destroy(pblk->page_bio_pool);
 	return -ENOMEM;
 }
 
@@ -322,7 +323,7 @@ static void pblk_core_free(struct pblk *pblk)
 	if (pblk->bb_wq)
 		destroy_workqueue(pblk->bb_wq);
 
-	mempool_destroy(pblk->page_pool);
+	mempool_destroy(pblk->page_bio_pool);
 	mempool_destroy(pblk->line_ws_pool);
 	mempool_destroy(pblk->rec_pool);
 	mempool_destroy(pblk->g_rq_pool);
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index ee8efb55b330..402c732f0970 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -238,7 +238,7 @@ static int pblk_fill_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
 		kunmap_atomic(src_p);
 		kunmap_atomic(dst_p);
 
-		mempool_free(src_bv.bv_page, pblk->page_pool);
+		mempool_free(src_bv.bv_page, pblk->page_bio_pool);
 
 		hole = find_next_zero_bit(read_bitmap, nr_secs, hole + 1);
 	} while (hole < nr_secs);
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index b592e5194b0f..229f6020ad8a 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -620,7 +620,7 @@ struct pblk {
 
 	struct list_head compl_list;
 
-	mempool_t *page_pool;
+	mempool_t *page_bio_pool;
 	mempool_t *line_ws_pool;
 	mempool_t *rec_pool;
 	mempool_t *g_rq_pool;
-- 
2.12.3