[Ocfs2-devel] [PATCH] ocfs2: return -EROFS to upper if inode block is invalid

[piaojun]

Hi Joseph,

On 2017/12/26 14:59, Joseph Qi wrote:
> 
> 
> On 17/12/26 14:45, piaojun wrote:
>> Hi Joseph,
>>
>> On 2017/12/26 14:10, Joseph Qi wrote:
>>>
>>>
>>> On 17/12/26 13:35, piaojun wrote:
>>>> Hi Joseph,
>>>>
>>>> On 2017/12/26 11:05, Joseph Qi wrote:
>>>>>
>>>>>
>>>>> On 17/12/26 10:11, piaojun wrote:
>>>>>> If metadata is corrupted such as 'invalid inode block', we will get
>>>>>> failed by calling 'mount()' as below:
>>>>>>
>>>>>> ocfs2_mount
>>>>>>   ocfs2_initialize_super
>>>>>>     ocfs2_init_global_system_inodes : return -EINVAL if inode is NULL
>>>>>>       ocfs2_get_system_file_inode
>>>>>>         _ocfs2_get_system_file_inode : return NULL if inode is errno
>>>>> Do you mean inode is bad?
>>>>>
>>>> Here we have to face two abnormal cases:
>>>> 1. inode is bad;
>>>> 2. read inode from disk failed due to bad storage link.
>>>>>>           ocfs2_iget
>>>>>>             ocfs2_read_locked_inode
>>>>>>               ocfs2_validate_inode_block
>>>>>>
>>>>>> In this situation we need return -EROFS to upper application, so that
>>>>>> user can fix it by fsck. And then mount again.
>>>>>>
>>>>>> Signed-off-by: Jun Piao <piaojun at huawei.com>
>>>>>> Reviewed-by: Alex Chen <alex.chen at huawei.com>
>>>>>> ---
>>>>>>  fs/ocfs2/super.c | 10 ++++++++--
>>>>>>  1 file changed, 8 insertions(+), 2 deletions(-)
>>>>>>
>>>>>> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
>>>>>> index 040bbb6..dea21a7 100644
>>>>>> --- a/fs/ocfs2/super.c
>>>>>> +++ b/fs/ocfs2/super.c
>>>>>> @@ -474,7 +474,10 @@ static int ocfs2_init_global_system_inodes(struct ocfs2_super *osb)
>>>>>>  		new = ocfs2_get_system_file_inode(osb, i, osb->slot_num);
>>>>>>  		if (!new) {
>>>>>>  			ocfs2_release_system_inodes(osb);
>>>>>> -			status = -EINVAL;
>>>>>> +			if (ocfs2_is_soft_readonly(osb))
>>>>> I'm afraid that having bad inode doesn't means ocfs2 is readonly.
>>>>> And the calling application is mount.ocfs2. So do you mean mount.ocfs2
>>>>> have to handle EROFS like printing corresponding error log?
>>>>>
>>>> I agree that 'bad inode' also means other abnormal cases like
>>>> 'bad storage link' or 'no memory', but we can distinguish that by
>>>> ocfs2_is_soft_readonly(). I found that 'mount.ocfs2' did not
>>>> distinguish any error type and just return 1 for all error cases. I
>>>> wonder if we should return the exact errno for users?
>>>> Soft readonly is an in-memory status. The case you described is just
>>> trying to read inode and then check if it is bad. So where to set the
>>> status before?
>>>
>> we set readonly status in the following process:
>> ocfs2_validate_inode_block()
>>   ocfs2_error
>>     ocfs2_handle_error
>>       ocfs2_set_ro_flag(osb, 0);
>>
>> I have a suggestion that we could distinguish readonly status in
>> 'mount.ocfs2', and return -EROFS to users so that they can fix it.
> IC. Please update this information to patch description as well.
> And suggest just use ternary operator instead of if/else.
> BTW, so mount.ocfs2 should be updated correspondingly, right?
> 
> Thanks,
> Joseph

Thanks for your advices, and I will post a patch for mount.ocfs2
correspondingly.

>>>> thanks,
>>>> Jun
>>>>
>>>>>> +				status = -EROFS;
>>>>>> +			else
>>>>>> +				status = -EINVAL;
>>>>>>  			mlog_errno(status);
>>>>>>  			/* FIXME: Should ERROR_RO_FS */
>>>>>>  			mlog(ML_ERROR, "Unable to load system inode %d, "
>>>>>> @@ -505,7 +508,10 @@ static int ocfs2_init_local_system_inodes(struct ocfs2_super *osb)
>>>>>>  		new = ocfs2_get_system_file_inode(osb, i, osb->slot_num);
>>>>>>  		if (!new) {
>>>>>>  			ocfs2_release_system_inodes(osb);
>>>>>> -			status = -EINVAL;
>>>>>> +			if (ocfs2_is_soft_readonly(osb))
>>>>>> +				status = -EROFS;
>>>>>> +			else
>>>>>> +				status = -EINVAL;
>>>>>>  			mlog(ML_ERROR, "status=%d, sysfile=%d, slot=%d\n",
>>>>>>  			     status, i, osb->slot_num);
>>>>>>  			goto bail;
>>>>>>
>>>>> .
>>>>>
>>> .
>>>
> .
>