2024-05-09 09:33:55

by Jinjie Ruan

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Subject: [PATCH] null_blk: Add __must_hold macro for null_flush_cache_page()

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 <[email protected]>
---
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