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

[piaojun]

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?

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;
>>
> .
>