[PATCH AUTOSEL for 4.14 131/135] lightnvm: pblk: protect line bitmap while submitting meta io

[alexander . levin]

From: Rakesh Pandit <rakesh@xxxxxxxxxx>

[ Upstream commit e57903fd972a398b7140d0bc055714e13a0e58c5 ]

It seems pblk_dealloc_page would race against pblk_alloc_pages for
line bitmap for sector allocation.The chances are very low but might
as well protect the bitmap properly.

Signed-off-by: Rakesh Pandit <rakesh@xxxxxxxxxx>
Reviewed-by: Javier GonzÃlez <javier@xxxxxxxxxxxx>
Signed-off-by: Matias BjÃrling <m@xxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
 drivers/lightnvm/pblk-core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index bb3e9d5d4276..3f0ddc0d7393 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -486,12 +486,14 @@ void pblk_dealloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs)
 	u64 addr;
 	int i;
 
+	spin_lock(&line->lock);
 	addr = find_next_zero_bit(line->map_bitmap,
 					pblk->lm.sec_per_line, line->cur_sec);
 	line->cur_sec = addr - nr_secs;
 
 	for (i = 0; i < nr_secs; i++, line->cur_sec--)
 		WARN_ON(!test_and_clear_bit(line->cur_sec, line->map_bitmap));
+	spin_unlock(&line->lock);
 }
 
 u64 __pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs)
-- 
2.11.0