Re: [PATCH 1/4] f2fs: fix to do cast in F2FS_{BLK_TO_BYTES, BTYES_TO_BLK} to avoid overflow

[Chao Yu <chao@kernel.org>]

On 2024/11/19 2:07, Jaegeuk Kim wrote:
> I applied this with the below change to avoid build failure.

Thank you!

Thanks,
> 
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -3336,7 +3336,7 @@ loff_t max_file_blocks(struct inode *inode)
>           * fit within U32_MAX + 1 data units.
>           */
> 
> -       result = min(result, F2FS_BYTES_TO_BLK(((loff_t)U32_MAX + 1) * 4096));
> +       result = umin(result, F2FS_BYTES_TO_BLK(((loff_t)U32_MAX + 1) * 4096));
> 
>          return result;
>   }
> 
> On 11/08, Chao Yu wrote:
>> It missed to cast variable to unsigned long long type before
>> bit shift, which will cause overflow, fix it.
>>
>> Fixes: f7ef9b83b583 ("f2fs: introduce macros to convert bytes and blocks in f2fs")
>> Signed-off-by: Chao Yu <chao@kernel.org>
>> ---
>>   include/linux/f2fs_fs.h | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
>> index b0b821edfd97..3b2ad444c002 100644
>> --- a/include/linux/f2fs_fs.h
>> +++ b/include/linux/f2fs_fs.h
>> @@ -24,10 +24,10 @@
>>   #define NEW_ADDR		((block_t)-1)	/* used as block_t addresses */
>>   #define COMPRESS_ADDR		((block_t)-2)	/* used as compressed data flag */
>>   
>> -#define F2FS_BYTES_TO_BLK(bytes)	((bytes) >> F2FS_BLKSIZE_BITS)
>> -#define F2FS_BLK_TO_BYTES(blk)		((blk) << F2FS_BLKSIZE_BITS)
>> +#define F2FS_BYTES_TO_BLK(bytes)	((unsigned long long)(bytes) >> F2FS_BLKSIZE_BITS)
>> +#define F2FS_BLK_TO_BYTES(blk)		((unsigned long long)(blk) << F2FS_BLKSIZE_BITS)
>>   #define F2FS_BLK_END_BYTES(blk)		(F2FS_BLK_TO_BYTES(blk + 1) - 1)
>> -#define F2FS_BLK_ALIGN(x)			(F2FS_BYTES_TO_BLK((x) + F2FS_BLKSIZE - 1))
>> +#define F2FS_BLK_ALIGN(x)		(F2FS_BYTES_TO_BLK((x) + F2FS_BLKSIZE - 1))
>>   
>>   /* 0, 1(node nid), 2(meta nid) are reserved node id */
>>   #define F2FS_RESERVED_NODE_NUM		3
>> -- 
>> 2.40.1