Hi Jaegeuk and Chao,
On 2018/1/26 9:36, Chao Yu wrote:
> On 2018/1/26 6:06, Jaegeuk Kim wrote:
>>
>> Then, we don't need to wait for this as well as wait_on_all_pages_writeback()
>> in the early stage in do_checkpoint()?
>>
>> So, it seems like we can modify like below:
>>
>> ---
>> 1. while (get_pages())
>> sync_meta_pages()
>> 2. if (enabled_nat_bits())
>> while (get_pages())
>> sync_meta_pages()
>>
>> 3. wait_on_all_pages_writeback()
>> -> remove
>
> Would meta area across two devices? if it would, we need to wait all meta
> be persisted in second device before f2fs_flush_device_cache?
>
>>
>> 4. f2fs_flush_device_cache()
>>
>> 5. update_meta_page() <- for first cp_block
>>
>> 6. update_meta_page()... <- payload
>>
>> 7. orphan writes
>>
>> 8. node_summary writes
>>
>> 9. update_meta_page() <- for last cp_block
>> -> remove
>
- /* writeout checkpoint block */
- update_meta_page(sbi, ckpt, start_blk);
-
- /* wait for previous submitted node/meta pages writeback */
- wait_on_all_pages_writeback(sbi);
-
- if (unlikely(f2fs_cp_error(sbi)))
- return -EIO;
-
Could also be removed, too?
filemap_fdatawait_range(NODE_MAPPING(sbi), 0, LLONG_MAX);
filemap_fdatawait_range(META_MAPPING(sbi), 0, LLONG_MAX);
> 9.1 sync_meta_pages(META) to make sure all meta IOs are issued.
>
If I understand correctly, I have the same questions with Chao.
It seems that META doesn't have another flush mechanism (eg. flush
thread) other than sync_meta_pages?
>>
>> 10. wait_on_all_pages_writeback()
>>
>> ----
>> Add) 11. commit_checkpoint()
>> - update_meta_page() <- for last cp_block
>> - sync_meta_pages(META_FLUSH)
>>
>> We don't need to wait for page_writeback any more.
>>
Apart from that, I think we should "wait_on_all_pages_writeback(sbi);"
after META_FLUSH in case for pulluting the next checkpoint when the last
cp block is failed to write with FUA?
Thanks all,
>>>
>>> @@ -1313,10 +1337,15 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
>>> sbi->last_valid_block_count = sbi->total_valid_block_count;
>>> percpu_counter_set(&sbi->alloc_valid_block_count, 0);
>>>
>>> - /* Here, we only have one bio having CP pack */
>>> - sync_meta_pages(sbi, META_FLUSH, LONG_MAX, FS_CP_META_IO);
>>> + /* Here, we have one bio having CP pack except cp pack 2 page */
>>> + sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO);
>>>
>>> /* wait for previous submitted meta pages writeback */
>>> + if (!test_opt(sbi, NOBARRIER))
>>
>> The above has nothing to do with this patch.
>
> We only need to use wait_on_all_pages_writeback to keep writeback order of
> previous metadata and last cp pack metadata if barrier is on?
>
> Thanks,
>
>>
>>> + wait_on_all_pages_writeback(sbi);
>>> +
>>> + /* barrier and flush checkpoint cp pack 2 page */
>>> + commit_checkpoint(sbi, ckpt, start_blk);
>>> wait_on_all_pages_writeback(sbi);
>>>
>>> release_ino_entry(sbi, false);
>>> --
>>> 2.1.4
>>
>> .
>>
>
