lightnvm: pblk: protect line bitmap while submitting meta io

[ 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@tuxera.com>
Reviewed-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index bb3e9d5..3f0ddc0 100644 (file)
--- 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)