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From: Jinjie Ruan <ruanjinjie@huawei.com>
To: <axboe@kernel.dk>, <dlemoal@kernel.org>, <hare@suse.de>,
	<johannes.thumshirn@wdc.com>, <ming.lei@redhat.com>,
	<zhouchengming@bytedance.com>, <nj.shetty@samsung.com>,
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	<shinichiro.kawasaki@wdc.com>, <linux-block@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
CC: <ruanjinjie@huawei.com>
Subject: [PATCH] null_blk: Add __must_hold macro for null_flush_cache_page()
Date: Thu, 9 May 2024 17:33:04 +0800
Message-ID: <20240509093304.1618775-1-ruanjinjie@huawei.com>
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It seems that call null_flush_cache_page() must hold nullb->lock and it
returns with nullb->lock held. However, this is not clearly described, and
the caller may forget to hold the lock. Therefore, add __must_hold() macro
to the function entry to show that the lock is held on function entry and
exit, which allows sparse to do lock checking.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 drivers/block/null_blk/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index ed33cf7192d2..adca31e55deb 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1013,7 +1013,7 @@ static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page)
 	return 0;
 }
 
-static int null_make_cache_space(struct nullb *nullb, unsigned long n)
+static int null_make_cache_space(struct nullb *nullb, unsigned long n) __must_hold(&nullb->lock)
 {
 	int i, err, nr_pages;
 	struct nullb_page *c_pages[FREE_BATCH];
-- 
2.34.1