RE:(2) [PATCH] f2fs: fix null reference error when checking end of zone

[Daejun Park <daejun7.park@samsung.com>]

Hi Chao Yu,
> 
>--------- Original Message ---------
>Sender : Chao Yu <chao@kernel.org>
>Date : 2024-07-04 16:16 (GMT+9)
>Title : Re: [PATCH] f2fs: fix null reference error when checking end of zone
> 
>On 2024/7/4 9:01, Daejun Park wrote:
>> This patch fixes a potentially null pointer being accessed by
>> is_end_zone_blkaddr() that checks the last block of a zone
>> when f2fs is mounted as a single device.
>
>blkzoned feature depends on multiple device feature? One regular
>device and one seq-zone device?

According to mkfs.f2fs, if there are a sufficient number of
conventional zones, a single zoned device can be used.

Thanks,
Daejun

>
>Thanks,
>
>>
>> Fixes: e067dc3c6b9c ("f2fs: maintain six open zones for zoned devices")
>> Signed-off-by: Daejun Park <daejun7.park@samsung.com>
>> ---
>>  fs/f2fs/data.c 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>> index b6dcb3bcaef7..1aa7eefa659c 100644
>> --- a/fs/f2fs/data.c
>> +++ b/fs/f2fs/data.c
>> @@ -925,6 +925,7 @@ int f2fs_merge_page_bio(struct f2fs_io_info *fio)
>>  #ifdef CONFIG_BLK_DEV_ZONED
>>  static bool is_end_zone_blkaddr(struct f2fs_sb_info *sbi, block_t blkaddr)
>>  {
>> +        struct block_device *bdev = sbi->sb->s_bdev;
>>           int devi = 0;
>> 
>>           if (f2fs_is_multi_device(sbi)) {
>> @@ -935,8 +936,9 @@ static bool is_end_zone_blkaddr(struct f2fs_sb_info *sbi, block_t blkaddr)
>>                           return false;
>>                   }
>>                   blkaddr -= FDEV(devi).start_blk;
>> +                bdev = FDEV(devi).bdev;
>>           }
>> -        return bdev_is_zoned(FDEV(devi).bdev) &&
>> +        return bdev_is_zoned(bdev) &&
>>                   f2fs_blkz_is_seq(sbi, devi, blkaddr) &&
>>                   (blkaddr % sbi->blocks_per_blkz == sbi->blocks_per_blkz - 1);
>>  }