On 2019/7/23 9:35, Jaegeuk Kim wrote:
> On 07/16, Chao Yu wrote:
>> Hi Jaegeuk,
>>
>> On 2019/5/9 9:15, Chao Yu wrote:
>>> On 2019/5/5 10:51, Chao Yu wrote:
>>>> On 2019/5/1 11:22, Jaegeuk Kim wrote:
>>>>> On 04/29, Chao Yu wrote:
>>>>>> On 2019-4-28 21:38, Jaegeuk Kim wrote:
>>>>>>> On 04/24, Chao Yu wrote:
>>>>>>>> This patch fixes to do sanity with enabled features in image, if
>>>>>>>> there are features kernel can not recognize, just fail the mount.
>>>>>>>
>>>>>>> We need to figure out per-feature-based rejection, since some of them 
>>>>>>> can
>>>>>>> be set without layout change.
>>
>> What about adding one field in superblock for compatible features in future?
>>
>> sb.feature(F2FS_FEATURE_LAST, max] stores uncompatible features
>> sb.compatible_feature stores compatible features
>>
>> If we follow above rule when adding one feature, then, we can fail the mount 
>> if
>> sb.feature(F2FS_FEATURE_LAST, max] is valid.
> 
> How about adding required_features flag in sb to check part of features only?

You mean all incompatible features can be add into sb.required_features later
like this?

__le32 required_features;       /* incompatible feature to old kernel */

And we can check required_features with supported features in current kernel?

if (le32_to_cpu(raw_super->required_features) &
        (~NOW_SUPPORTED_FEATURES_IN_CURRENT_KERNEL)) {
        print msg & ret error;
}

Thanks,

> 
>>
>> Thanks,
>>
>>>>>>
>>>>>> So any suggestion on how to implement this?
>>>>>
>>>>> Which features do we need to disallow? When we introduce new features, 
>>>>> they
>>>>
>>>> I guess it should be the new features.
>>>>
>>>>> didn't hurt the previous flow by checking f2fs_sb_has_###().
>>>>
>>>> Yes, but new features may use new disk layout, if old kernel handled it 
>>>> with old
>>>> disk layout, there must be problematic.
>>>>
>>>> e.g. format image with -O extra_attr, and mount it with kernel who don't
>>>> recognize new inode layout.
>>>
>>> Jaegeuk,
>>>
>>> Any thoughts?
>>>
>>> Thanks,
>>>
>>>>
>>>> Thanks,
>>>>
>>>>>
>>>>>>
>>>>>> Maybe:
>>>>>>
>>>>>> if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 14, 0))
>>>>>>  check 4.14+ features
>>>>>> else if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 0))
>>>>>>  check 4.9+ features
>>>>>> else if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 4, 0))
>>>>>>  check 4.4+ features
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> Signed-off-by: Chao Yu <yuch...@huawei.com>
>>>>>>>> ---
>>>>>>>>  fs/f2fs/f2fs.h  | 13 +++++++++++++
>>>>>>>>  fs/f2fs/super.c |  9 +++++++++
>>>>>>>>  2 files changed, 22 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>>>>>>> index f5ffc09705eb..15b640967e12 100644
>>>>>>>> --- a/fs/f2fs/f2fs.h
>>>>>>>> +++ b/fs/f2fs/f2fs.h
>>>>>>>> @@ -151,6 +151,19 @@ struct f2fs_mount_info {
>>>>>>>>  #define F2FS_FEATURE_VERITY           0x0400  /* reserved */
>>>>>>>>  #define F2FS_FEATURE_SB_CHKSUM                0x0800
>>>>>>>>  
>>>>>>>> +#define F2FS_ALL_FEATURES     (F2FS_FEATURE_ENCRYPT |                 
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_BLKZONED |                 
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_ATOMIC_WRITE |             
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_EXTRA_ATTR |               
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_PRJQUOTA |                 
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_INODE_CHKSUM |             
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_FLEXIBLE_INLINE_XATTR |    
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_QUOTA_INO |                
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_INODE_CRTIME |             
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_LOST_FOUND |               
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_VERITY |                   
>>>>>>>> \
>>>>>>>> +                              F2FS_FEATURE_SB_CHKSUM)
>>>>>>>> +
>>>>>>>>  #define __F2FS_HAS_FEATURE(raw_super, mask)                           
>>>>>>>> \
>>>>>>>>        ((raw_super->feature & cpu_to_le32(mask)) != 0)
>>>>>>>>  #define F2FS_HAS_FEATURE(sbi, mask)   
>>>>>>>> __F2FS_HAS_FEATURE(sbi->raw_super, mask)
>>>>>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>>>>>>> index 4f8e9ab48b26..57f2fc6d14ba 100644
>>>>>>>> --- a/fs/f2fs/super.c
>>>>>>>> +++ b/fs/f2fs/super.c
>>>>>>>> @@ -2573,6 +2573,15 @@ static int sanity_check_raw_super(struct 
>>>>>>>> f2fs_sb_info *sbi,
>>>>>>>>                return 1;
>>>>>>>>        }
>>>>>>>>  
>>>>>>>> +      /* check whether kernel supports all features */
>>>>>>>> +      if (le32_to_cpu(raw_super->feature) & (~F2FS_ALL_FEATURES)) {
>>>>>>>> +              f2fs_msg(sb, KERN_INFO,
>>>>>>>> +                      "Unsupported feature:%u: supported:%u",
>>>>>>>> +                      le32_to_cpu(raw_super->feature),
>>>>>>>> +                      F2FS_ALL_FEATURES);
>>>>>>>> +              return 1;
>>>>>>>> +      }
>>>>>>>> +
>>>>>>>>        /* check CP/SIT/NAT/SSA/MAIN_AREA area boundary */
>>>>>>>>        if (sanity_check_area_boundary(sbi, bh))
>>>>>>>>                return 1;
>>>>>>>> -- 
>>>>>>>> 2.18.0.rc1
>>>>> .
>>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Linux-f2fs-devel mailing list
>>>> Linux-f2fs-devel@lists.sourceforge.net
>>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>>> .
>>>>
>>>
>>>
>>> _______________________________________________
>>> Linux-f2fs-devel mailing list
>>> Linux-f2fs-devel@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>> .
>>>
> .
> 


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