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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Xie Yongji <xieyongji@bytedance.com>,
        Jens Axboe <axboe@kernel.dk>, Lee Jones <lee.jones@linaro.org>
Subject: [PATCH 4.19 014/338] block: Add a helper to validate the block size
Date:   Thu, 14 Apr 2022 15:08:37 +0200
Message-Id: <20220414110839.298193727@linuxfoundation.org>
In-Reply-To: <20220414110838.883074566@linuxfoundation.org>
References: <20220414110838.883074566@linuxfoundation.org>
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From: Xie Yongji <xieyongji@bytedance.com>

commit 570b1cac477643cbf01a45fa5d018430a1fddbce upstream.

There are some duplicated codes to validate the block
size in block drivers. This limitation actually comes
from block layer, so this patch tries to add a new block
layer helper for that.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20211026144015.188-2-xieyongji@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/blkdev.h |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -56,6 +56,14 @@ struct blk_stat_callback;
  */
 #define BLKCG_MAX_POLS		5
 
+static inline int blk_validate_block_size(unsigned int bsize)
+{
+	if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize))
+		return -EINVAL;
+
+	return 0;
+}
+
 typedef void (rq_end_io_fn)(struct request *, blk_status_t);
 
 #define BLK_RL_SYNCFULL		(1U << 0)