linux-kernel - [PATCH] drivers/block/zram/zram_drv.c: remove WARN_ON_ONCE() in free_block

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Date:   Wed, 26 Feb 2020 16:32:17 +0800
From:   Yue Hu <zbestahu@...il.com>
To:     minchan@...nel.org, ngupta@...are.org,
        sergey.senozhatsky.work@...il.com, axboe@...nel.dk
Cc:     linux-kernel@...r.kernel.org, linux-block@...r.kernel.org,
        huyue2@...ong.com, zbestahu@....com
Subject: [PATCH] drivers/block/zram/zram_drv.c: remove WARN_ON_ONCE() in free_block_bdev()

From: Yue Hu <huyue2@...ong.com>

Currently, free_block_bdev() only happens after calling alloc_block_bdev()
which will ensure blk_idx bit to be set using test_and_set_bit(). So no
need to do WARN_ON_ONCE(!was_set) again when freeing.

Signed-off-by: Yue Hu <huyue2@...ong.com>
---
 drivers/block/zram/zram_drv.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 1bdb579..61b10ab 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -570,10 +570,7 @@ static unsigned long alloc_block_bdev(struct zram *zram)
 
 static void free_block_bdev(struct zram *zram, unsigned long blk_idx)
 {
-	int was_set;
-
-	was_set = test_and_clear_bit(blk_idx, zram->bitmap);
-	WARN_ON_ONCE(!was_set);
+	clear_bit(blk_idx, zram->bitmap);
 	atomic64_dec(&zram->stats.bd_count);
 }
 
-- 
1.9.1