linux-kernel - [PATCH] loop: avoid out-of-range warning

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Date:   Mon, 27 Sep 2021 11:43:00 +0200
From:   Arnd Bergmann <arnd@...nel.org>
To:     Jens Axboe <axboe@...nel.dk>,
        Nathan Chancellor <nathan@...nel.org>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Martijn Coenen <maco@...roid.com>
Cc:     Arnd Bergmann <arnd@...db.de>,
        Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>,
        Dan Schatzberg <schatzberg.dan@...il.com>,
        linux-block@...r.kernel.org, linux-kernel@...r.kernel.org,
        llvm@...ts.linux.dev
Subject: [PATCH] loop: avoid out-of-range warning

From: Arnd Bergmann <arnd@...db.de>

clang warns that the sanity check for page size always succeeds
when building with 64KB pages:

drivers/block/loop.c:282:27: error: result of comparison of constant 65536 with expression of type 'unsigned short' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
        if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize))
                           ~~~~~ ^ ~~~~~~~~~

There is nothing wrong here, so just shut up the check by changing
the type of the bsize argument.

Fixes: 3448914e8cc5 ("loop: Add LOOP_CONFIGURE ioctl")
Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 drivers/block/loop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 7bf4686af774..51315a93b399 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -277,7 +277,7 @@ static void __loop_update_dio(struct loop_device *lo, bool dio)
  * @bsize: size to validate
  */
 static int
-loop_validate_block_size(unsigned short bsize)
+loop_validate_block_size(unsigned int bsize)
 {
 	if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize))
 		return -EINVAL;
-- 
2.29.2