releases/5.14.21/block-add-a-helper-to-validate-the-block-size.patch

From 570b1cac477643cbf01a45fa5d018430a1fddbce Mon Sep 17 00:00:00 2001
From: Xie Yongji <xieyongji@bytedance.com>
Date: Tue, 26 Oct 2021 22:40:12 +0800
Subject: block: Add a helper to validate the block size

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: 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
@@ -240,6 +240,14 @@ struct request {
 	void *end_io_data;
 };
 
+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;
+}
+
 static inline bool blk_op_is_passthrough(unsigned int op)
 {
 	op &= REQ_OP_MASK;