Re: 答复: [PATCH] f2fs: fix a infinite loop in writting checkpoint

[Chao Yu <yuchao0@huawei.com>]

On 2017/9/1 12:19, heyunlei wrote:
> 
> Hi Yunlei,
> 
> On 2017/8/26 12:15, Yunlei He wrote:
>> The loop reason is DIRTY IMETA always equal to 1:
>>
>> Thread A:
>> -write_checkpoint
>>    -block_operations
>>        -f2fs_sync_inode_meta
>>            -igrab       <--- here igrab return NULL
>>
>> Thread B:
>> -f2fs_evict_inode
>>    -remove_inode_page
>>        -truncate_xattr_node
>>           -__get_node_page
>>              -read_node_page   <---- here return -ENOENT
>>
>> This patch walk around this cause.
> 
> It needs to figure out root cause that why xattr node entry is invalid.
> 
> How about this modification:
> 
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index b4c401d..62de5f7 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -497,7 +497,7 @@ void f2fs_evict_inode(struct inode *inode)
>                 f2fs_lock_op(sbi);
>                 err = remove_inode_page(inode);
>                 f2fs_unlock_op(sbi);
> -               if (err == -ENOENT)
> +               if (err == -ENOENT && is_bad_inode(inode))

So we expect that before new inode page was allocated, it needs to set bad inode
in time covering all error paths?

Thanks,

>                         err = 0;
>         }
> 
> Thanks
> 
>>
>> Signed-off-by: Yunlei He <heyunlei@huawei.com>
>> ---
>>  fs/f2fs/node.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 2654c91..ec7a0e0 
>> 100644
>> --- a/fs/f2fs/node.c
>> +++ b/fs/f2fs/node.c
>> @@ -973,8 +973,9 @@ int truncate_xattr_node(struct inode *inode, struct page *page)
>>  		return 0;
>>  
>>  	npage = get_node_page(sbi, nid);
>> -	if (IS_ERR(npage))
>> +	if (IS_ERR(npage) && PTR_ERR(npage) != -ENOENT) {
>>  		return PTR_ERR(npage);
>> +	}
>>  
>>  	f2fs_i_xnid_write(inode, 0);
>>  
>>
> 


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