[PATCH] f2fs: fix to redirty page if fail to gc data page

[PATCH] f2fs: fix to redirty page if fail to gc data page

[Chao Yu]

From: Chao Yu <yuchao0@huawei.com>

If we fail to move data page during foreground GC, we should give another
chance to writeback that page which was set dirty previously by writer.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 fs/f2fs/gc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 38d56f6..ee213a8 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -653,12 +653,15 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type)
 			.page = page,
 			.encrypted_page = NULL,
 		};
+		bool is_dirty = PageDirty(page);
+
 		set_page_dirty(page);
 		f2fs_wait_on_page_writeback(page, DATA, true);
 		if (clear_page_dirty_for_io(page))
 			inode_dec_dirty_pages(inode);
 		set_cold_data(page);
-		do_write_data_page(&fio);
+		if (do_write_data_page(&fio) && is_dirty)
+			set_page_dirty(page);
 		clear_cold_data(page);
 	}
 out:
-- 
2.7.2

Re: [PATCH] f2fs: fix to redirty page if fail to gc data page

[Chao Yu]

Ping,

On 2016/5/21 13:19, Chao Yu wrote:
> From: Chao Yu <yuchao0@huawei.com>
> 
> If we fail to move data page during foreground GC, we should give another
> chance to writeback that page which was set dirty previously by writer.
> 
> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> ---
>  fs/f2fs/gc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 38d56f6..ee213a8 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -653,12 +653,15 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type)
>  			.page = page,
>  			.encrypted_page = NULL,
>  		};
> +		bool is_dirty = PageDirty(page);
> +
>  		set_page_dirty(page);
>  		f2fs_wait_on_page_writeback(page, DATA, true);
>  		if (clear_page_dirty_for_io(page))
>  			inode_dec_dirty_pages(inode);
>  		set_cold_data(page);
> -		do_write_data_page(&fio);
> +		if (do_write_data_page(&fio) && is_dirty)
> +			set_page_dirty(page);
>  		clear_cold_data(page);
>  	}
>  out:
> 

Re: [PATCH] f2fs: fix to redirty page if fail to gc data page

[Jaegeuk Kim]

Hi Chao,

On Sat, May 21, 2016 at 01:19:11PM +0800, Chao Yu wrote:
> From: Chao Yu <yuchao0@huawei.com>
> 
> If we fail to move data page during foreground GC, we should give another
> chance to writeback that page which was set dirty previously by writer.
> 
> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> ---
>  fs/f2fs/gc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 38d56f6..ee213a8 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -653,12 +653,15 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type)
>  			.page = page,
>  			.encrypted_page = NULL,
>  		};
> +		bool is_dirty = PageDirty(page);
> +
>  		set_page_dirty(page);
>  		f2fs_wait_on_page_writeback(page, DATA, true);
>  		if (clear_page_dirty_for_io(page))
>  			inode_dec_dirty_pages(inode);
>  		set_cold_data(page);
> -		do_write_data_page(&fio);
> +		if (do_write_data_page(&fio) && is_dirty)
> +			set_page_dirty(page);

If this page is truncated with -ENOENT, we don't need to set it dirty again.
I expect that, if we get an error here, do_garbage_collect() would retry FG_GC
again.

Thanks,

>  		clear_cold_data(page);
>  	}
>  out:
> -- 
> 2.7.2

Re: [PATCH] f2fs: fix to redirty page if fail to gc data page

[Chao Yu]

Hi Jaegeuk,

On 2016/5/30 10:37, Jaegeuk Kim wrote:
> Hi Chao,
> 
> On Sat, May 21, 2016 at 01:19:11PM +0800, Chao Yu wrote:
>> From: Chao Yu <yuchao0@huawei.com>
>>
>> If we fail to move data page during foreground GC, we should give another
>> chance to writeback that page which was set dirty previously by writer.
>>
>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
>> ---
>>  fs/f2fs/gc.c | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>> index 38d56f6..ee213a8 100644
>> --- a/fs/f2fs/gc.c
>> +++ b/fs/f2fs/gc.c
>> @@ -653,12 +653,15 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type)
>>  			.page = page,
>>  			.encrypted_page = NULL,
>>  		};
>> +		bool is_dirty = PageDirty(page);
>> +
>>  		set_page_dirty(page);
>>  		f2fs_wait_on_page_writeback(page, DATA, true);
>>  		if (clear_page_dirty_for_io(page))
>>  			inode_dec_dirty_pages(inode);
>>  		set_cold_data(page);
>> -		do_write_data_page(&fio);
>> +		if (do_write_data_page(&fio) && is_dirty)
>> +			set_page_dirty(page);
> 
> If this page is truncated with -ENOENT, we don't need to set it dirty again.

Agree

> I expect that, if we get an error here, do_garbage_collect() would retry FG_GC

IIRC, you have reworked the FG_GC flows changed from an infinite loop to trying
do the movement just one time. Here, I think if there are just few of blocks are
failed to be moved, we can give one more time for retrying. How do you think?

> again.
> 
> Thanks,
> 
>>  		clear_cold_data(page);
>>  	}
>>  out:
>> -- 
>> 2.7.2
> .
> 

Re: [PATCH] f2fs: fix to redirty page if fail to gc data page

[Jaegeuk Kim]

On Tue, May 31, 2016 at 02:10:50PM +0800, Chao Yu wrote:
> Hi Jaegeuk,
> 
> On 2016/5/30 10:37, Jaegeuk Kim wrote:
> > Hi Chao,
> > 
> > On Sat, May 21, 2016 at 01:19:11PM +0800, Chao Yu wrote:
> >> From: Chao Yu <yuchao0@huawei.com>
> >>
> >> If we fail to move data page during foreground GC, we should give another
> >> chance to writeback that page which was set dirty previously by writer.
> >>
> >> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> >> ---
> >>  fs/f2fs/gc.c | 5 ++++-
> >>  1 file changed, 4 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> >> index 38d56f6..ee213a8 100644
> >> --- a/fs/f2fs/gc.c
> >> +++ b/fs/f2fs/gc.c
> >> @@ -653,12 +653,15 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type)
> >>  			.page = page,
> >>  			.encrypted_page = NULL,
> >>  		};
> >> +		bool is_dirty = PageDirty(page);
> >> +
> >>  		set_page_dirty(page);
> >>  		f2fs_wait_on_page_writeback(page, DATA, true);
> >>  		if (clear_page_dirty_for_io(page))
> >>  			inode_dec_dirty_pages(inode);
> >>  		set_cold_data(page);
> >> -		do_write_data_page(&fio);
> >> +		if (do_write_data_page(&fio) && is_dirty)
> >> +			set_page_dirty(page);
> > 
> > If this page is truncated with -ENOENT, we don't need to set it dirty again.
> 
> Agree
> 
> > I expect that, if we get an error here, do_garbage_collect() would retry FG_GC
> 
> IIRC, you have reworked the FG_GC flows changed from an infinite loop to trying
> do the movement just one time. Here, I think if there are just few of blocks are
> failed to be moved, we can give one more time for retrying. How do you think?

Mostly I expected here -ENOENT caused by race condition.
Do we have another expectation?

Thanks,

> 
> > again.
> > 
> > Thanks,
> > 
> >>  		clear_cold_data(page);
> >>  	}
> >>  out:
> >> -- 
> >> 2.7.2
> > .
> > 

Re: [PATCH] f2fs: fix to redirty page if fail to gc data page

[Chao Yu]

On 2016/6/3 13:08, Jaegeuk Kim wrote:
> On Tue, May 31, 2016 at 02:10:50PM +0800, Chao Yu wrote:
>> Hi Jaegeuk,
>>
>> On 2016/5/30 10:37, Jaegeuk Kim wrote:
>>> Hi Chao,
>>>
>>> On Sat, May 21, 2016 at 01:19:11PM +0800, Chao Yu wrote:
>>>> From: Chao Yu <yuchao0@huawei.com>
>>>>
>>>> If we fail to move data page during foreground GC, we should give another
>>>> chance to writeback that page which was set dirty previously by writer.
>>>>
>>>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
>>>> ---
>>>>  fs/f2fs/gc.c | 5 ++++-
>>>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>>>> index 38d56f6..ee213a8 100644
>>>> --- a/fs/f2fs/gc.c
>>>> +++ b/fs/f2fs/gc.c
>>>> @@ -653,12 +653,15 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type)
>>>>  			.page = page,
>>>>  			.encrypted_page = NULL,
>>>>  		};
>>>> +		bool is_dirty = PageDirty(page);
>>>> +
>>>>  		set_page_dirty(page);
>>>>  		f2fs_wait_on_page_writeback(page, DATA, true);
>>>>  		if (clear_page_dirty_for_io(page))
>>>>  			inode_dec_dirty_pages(inode);
>>>>  		set_cold_data(page);
>>>> -		do_write_data_page(&fio);
>>>> +		if (do_write_data_page(&fio) && is_dirty)
>>>> +			set_page_dirty(page);
>>>
>>> If this page is truncated with -ENOENT, we don't need to set it dirty again.
>>
>> Agree
>>
>>> I expect that, if we get an error here, do_garbage_collect() would retry FG_GC
>>
>> IIRC, you have reworked the FG_GC flows changed from an infinite loop to trying
>> do the movement just one time. Here, I think if there are just few of blocks are
>> failed to be moved, we can give one more time for retrying. How do you think?
> 
> Mostly I expected here -ENOENT caused by race condition.

If we hit ENOENT case, we can pass get_valid_blocks check, so we don't need to
worry about this case, right?

> Do we have another expectation?

ENOMEM or EIO?

Thanks,

> 
> Thanks,
> 
>>
>>> again.
>>>
>>> Thanks,
>>>
>>>>  		clear_cold_data(page);
>>>>  	}
>>>>  out:
>>>> -- 
>>>> 2.7.2
>>> .
>>>
> .
> 

Re: [PATCH] f2fs: fix to redirty page if fail to gc data page

[Jaegeuk Kim]

On Fri, Jun 03, 2016 at 01:13:21PM +0800, Chao Yu wrote:
> On 2016/6/3 13:08, Jaegeuk Kim wrote:
> > On Tue, May 31, 2016 at 02:10:50PM +0800, Chao Yu wrote:
> >> Hi Jaegeuk,
> >>
> >> On 2016/5/30 10:37, Jaegeuk Kim wrote:
> >>> Hi Chao,
> >>>
> >>> On Sat, May 21, 2016 at 01:19:11PM +0800, Chao Yu wrote:
> >>>> From: Chao Yu <yuchao0@huawei.com>
> >>>>
> >>>> If we fail to move data page during foreground GC, we should give another
> >>>> chance to writeback that page which was set dirty previously by writer.
> >>>>
> >>>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> >>>> ---
> >>>>  fs/f2fs/gc.c | 5 ++++-
> >>>>  1 file changed, 4 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> >>>> index 38d56f6..ee213a8 100644
> >>>> --- a/fs/f2fs/gc.c
> >>>> +++ b/fs/f2fs/gc.c
> >>>> @@ -653,12 +653,15 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type)
> >>>>  			.page = page,
> >>>>  			.encrypted_page = NULL,
> >>>>  		};
> >>>> +		bool is_dirty = PageDirty(page);
> >>>> +
> >>>>  		set_page_dirty(page);
> >>>>  		f2fs_wait_on_page_writeback(page, DATA, true);
> >>>>  		if (clear_page_dirty_for_io(page))
> >>>>  			inode_dec_dirty_pages(inode);
> >>>>  		set_cold_data(page);
> >>>> -		do_write_data_page(&fio);
> >>>> +		if (do_write_data_page(&fio) && is_dirty)
> >>>> +			set_page_dirty(page);
> >>>
> >>> If this page is truncated with -ENOENT, we don't need to set it dirty again.
> >>
> >> Agree
> >>
> >>> I expect that, if we get an error here, do_garbage_collect() would retry FG_GC
> >>
> >> IIRC, you have reworked the FG_GC flows changed from an infinite loop to trying
> >> do the movement just one time. Here, I think if there are just few of blocks are
> >> failed to be moved, we can give one more time for retrying. How do you think?
> > 
> > Mostly I expected here -ENOENT caused by race condition.
> 
> If we hit ENOENT case, we can pass get_valid_blocks check, so we don't need to
> worry about this case, right?
> 
> > Do we have another expectation?
> 
> ENOMEM or EIO?

EIO will stop everything.
ENOMEM would be better to wait for a while from page reclaim?

> 
> Thanks,
> 
> > 
> > Thanks,
> > 
> >>
> >>> again.
> >>>
> >>> Thanks,
> >>>
> >>>>  		clear_cold_data(page);
> >>>>  	}
> >>>>  out:
> >>>> -- 
> >>>> 2.7.2
> >>> .
> >>>
> > .
> > 

Re: [PATCH] f2fs: fix to redirty page if fail to gc data page

[Chao Yu]

On 2016/6/3 13:17, Jaegeuk Kim wrote:
> On Fri, Jun 03, 2016 at 01:13:21PM +0800, Chao Yu wrote:
>> On 2016/6/3 13:08, Jaegeuk Kim wrote:
>>> On Tue, May 31, 2016 at 02:10:50PM +0800, Chao Yu wrote:
>>>> Hi Jaegeuk,
>>>>
>>>> On 2016/5/30 10:37, Jaegeuk Kim wrote:
>>>>> Hi Chao,
>>>>>
>>>>> On Sat, May 21, 2016 at 01:19:11PM +0800, Chao Yu wrote:
>>>>>> From: Chao Yu <yuchao0@huawei.com>
>>>>>>
>>>>>> If we fail to move data page during foreground GC, we should give another
>>>>>> chance to writeback that page which was set dirty previously by writer.
>>>>>>
>>>>>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
>>>>>> ---
>>>>>>  fs/f2fs/gc.c | 5 ++++-
>>>>>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>>>>>> index 38d56f6..ee213a8 100644
>>>>>> --- a/fs/f2fs/gc.c
>>>>>> +++ b/fs/f2fs/gc.c
>>>>>> @@ -653,12 +653,15 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type)
>>>>>>  			.page = page,
>>>>>>  			.encrypted_page = NULL,
>>>>>>  		};
>>>>>> +		bool is_dirty = PageDirty(page);
>>>>>> +
>>>>>>  		set_page_dirty(page);
>>>>>>  		f2fs_wait_on_page_writeback(page, DATA, true);
>>>>>>  		if (clear_page_dirty_for_io(page))
>>>>>>  			inode_dec_dirty_pages(inode);
>>>>>>  		set_cold_data(page);
>>>>>> -		do_write_data_page(&fio);
>>>>>> +		if (do_write_data_page(&fio) && is_dirty)
>>>>>> +			set_page_dirty(page);
>>>>>
>>>>> If this page is truncated with -ENOENT, we don't need to set it dirty again.
>>>>
>>>> Agree
>>>>
>>>>> I expect that, if we get an error here, do_garbage_collect() would retry FG_GC
>>>>
>>>> IIRC, you have reworked the FG_GC flows changed from an infinite loop to trying
>>>> do the movement just one time. Here, I think if there are just few of blocks are
>>>> failed to be moved, we can give one more time for retrying. How do you think?
>>>
>>> Mostly I expected here -ENOENT caused by race condition.
>>
>> If we hit ENOENT case, we can pass get_valid_blocks check, so we don't need to
>> worry about this case, right?
>>
>>> Do we have another expectation?
>>
>> ENOMEM or EIO?
> 
> EIO will stop everything.
> ENOMEM would be better to wait for a while from page reclaim?

Agree, but for ioctl path, IMO, we don't need to let user waiting for ENOMEM
case looping.

> 
>>
>> Thanks,
>>
>>>
>>> Thanks,
>>>
>>>>
>>>>> again.
>>>>>
>>>>> Thanks,
>>>>>
>>>>>>  		clear_cold_data(page);
>>>>>>  	}
>>>>>>  out:
>>>>>> -- 
>>>>>> 2.7.2
>>>>> .
>>>>>
>>> .
>>>
> .
> 

Re: [PATCH] f2fs: fix to redirty page if fail to gc data page

[Jaegeuk Kim]

On Fri, Jun 03, 2016 at 01:59:15PM +0800, Chao Yu wrote:
...

> >>> Do we have another expectation?
> >>
> >> ENOMEM or EIO?
> > 
> > EIO will stop everything.
> > ENOMEM would be better to wait for a while from page reclaim?
> 
> Agree, but for ioctl path, IMO, we don't need to let user waiting for ENOMEM
> case looping.

Well, if user wanted to do a synchronous gc, we need that, IMO.