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

From: Joseph Qi <jiangqi903@gmail.com>
To: ocfs2-devel@oss.oracle.com
Subject: [Ocfs2-devel] [PATCH] ocfs2: return -EROFS to upper if inode block is invalid
Date: Tue, 26 Dec 2017 14:59:33 +0800	[thread overview]
Message-ID: <008c191a-71b7-0cac-a356-9922b9f2d376@gmail.com> (raw)
In-Reply-To: <5A41F022.6040400@huawei.com>


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@huawei.com>
>>>>> Reviewed-by: Alex Chen <alex.chen@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,
>>> 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;
>>>>>
>>>> .
>>>>
>> .
>>