request for 4.14-stable: cd8ddbf7a5e2 ("lightnvm: pblk: free padded entries in write buffer")

[Sudip Mukherjee <sudipm.mukherjee@gmail.com>]

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Hi Greg,

This was not marked for stable but seems it should be. Please apply to
your queue.

--
Regards
Sudip

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>From b23d4174232324b5c1d476c317f9f8b8a5b948b4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javier=20Gonz=C3=A1lez?= <javier@cnexlabs.com>
Date: Fri, 13 Oct 2017 14:46:03 +0200
Subject: [PATCH] lightnvm: pblk: free padded entries in write buffer
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit

commit cd8ddbf7a5e206fe6995ab0aee245d597dd6a7f2 upstream

When a REQ_FLUSH reaches pblk, the bio cannot be directly completed.
Instead, data on the write buffer is flushed and the bio is completed on
the completion pah. This might require some sectors to be padded in
order to guarantee a successful write.

This patch fixes a memory leak on the padded pages. A consequence of
this bad free was that internal bios not containing data (only a flush)
were not being completed.

Fixes: a4bd217b4326 ("lightnvm: physical block device (pblk) target")
Signed-off-by: Javier Gonz�lez <javier@cnexlabs.com>
Signed-off-by: Matias Bj�rling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
---
 drivers/lightnvm/pblk-core.c  | 1 -
 drivers/lightnvm/pblk-write.c | 7 ++++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 3f0ddc0d7393..3fb65778e03d 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -190,7 +190,6 @@ void pblk_bio_free_pages(struct pblk *pblk, struct bio *bio, int off,
 
 	WARN_ON(off + nr_pages != bio->bi_vcnt);
 
-	bio_advance(bio, off * PBLK_EXPOSED_PAGE_SIZE);
 	for (i = off; i < nr_pages + off; i++) {
 		bv = bio->bi_io_vec[i];
 		mempool_free(bv.bv_page, pblk->page_bio_pool);
diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c
index 3ad9e56d2473..d89ac573f8d8 100644
--- a/drivers/lightnvm/pblk-write.c
+++ b/drivers/lightnvm/pblk-write.c
@@ -33,6 +33,10 @@ static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
 			bio_endio(original_bio);
 	}
 
+	if (c_ctx->nr_padded)
+		pblk_bio_free_pages(pblk, rqd->bio, c_ctx->nr_valid,
+							c_ctx->nr_padded);
+
 #ifdef CONFIG_NVM_DEBUG
 	atomic_long_add(c_ctx->nr_valid, &pblk->sync_writes);
 #endif
@@ -521,7 +525,8 @@ static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
 	struct bio *bio = rqd->bio;
 
 	if (c_ctx->nr_padded)
-		pblk_bio_free_pages(pblk, bio, rqd->nr_ppas, c_ctx->nr_padded);
+		pblk_bio_free_pages(pblk, bio, c_ctx->nr_valid,
+							c_ctx->nr_padded);
 }
 
 static int pblk_submit_write(struct pblk *pblk)
-- 
2.11.0