Re: [PATCHv2 3/3] reiser4: mark pages created during tail2extent conversion as dirty.

[Edward Shishkin <edward.shishkin@gmail.com>]

On 11/11/2015 11:30 AM, Edward Shishkin wrote:
>
>
> On 11/09/2015 01:18 PM, Edward Shishkin wrote:
>> On 10/25/2015 01:02 AM, Ivan Shapovalov wrote:
>>> This is responsible for an oops in v4.2 in
>>> write_jnodes_to_disk_extent() -> set_page_writeback().
>
>
> As to me, this patch doesn't prevent the oops,
> so someone else forgets to set pages dirty...


False alarm: I applied to the old stuff..
Everything woks without the hack in
write_jnodes_to_disk_extent().
Good work! Merged to reiser4-for-4.2.3.

Thanks,
Edward.

>
>
>>>
>>> The pages needs to be marked dirty before marked writeback.
>>>
>>>  From a similar problem in f2fs:
>>> "The cgroup attaches inode->i_wb via mark_inode_dirty and when
>>> set_page_writeback is called, __inc_wb_stat() updates i_wb's stat.
>>>
>>> So, we need to explicitly call set_page_dirty->__mark_inode_dirty in
>>> prior to any writebacking pages."
>>>
>>> Signed-off-by: Ivan Shapovalov <intelfx100@gmail.com>
>>> ---
>>>   fs/reiser4/plugin/file/tail_conversion.c | 1 +
>>>   1 file changed, 1 insertion(+)
>>>
>>> diff --git a/fs/reiser4/plugin/file/tail_conversion.c 
>>> b/fs/reiser4/plugin/file/tail_conversion.c
>>> index 7542c03..c856b73 100644
>>> --- a/fs/reiser4/plugin/file/tail_conversion.c
>>> +++ b/fs/reiser4/plugin/file/tail_conversion.c
>>> @@ -175,6 +175,7 @@ static int replace(struct inode *inode, struct 
>>> page **pages, unsigned nr_pages,
>>>                                   i_mapping));
>>>           if (result)
>>>               break;
>>> +        set_page_dirty_notag(pages[i]);
>>
>>
>> So, at this point the page is dirty but not uptodate.
>> I am confused with this. Why not to set the page
>> uptodate right before setting it dirty? At this point
>> everything has been copied already, so the page is
>> in fact uptodate. Could you please try this?
>>
>> Thanks,
>> Edward.
>>
>>
>>>           unlock_page(pages[i]);
>>>           result = find_or_create_extent(pages[i]);
>>>           if (result) {
>>
>