[PATCH] f2fs: return error number for quota_write

[PATCH] f2fs: return error number for quota_write

[Jaegeuk Kim]

This patch returns an error number to quota_write in order for quota to handle
it correctly.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/super.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 2feecf5e7f4c..840a0876005b 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1397,8 +1397,11 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type,
 
 		err = a_ops->write_begin(NULL, mapping, off, tocopy, 0,
 							&page, NULL);
-		if (unlikely(err))
+		if (unlikely(err)) {
+			if (len == towrite)
+				return err;
 			break;
+		}
 
 		kaddr = kmap_atomic(page);
 		memcpy(kaddr + offset, data, tocopy);
-- 
2.14.0.rc1.383.gd1ce394fe2-goog

Re: [PATCH] f2fs: return error number for quota_write

[Chao Yu]

Hi Jaegeuk,

On 2017/10/13 7:15, Jaegeuk Kim wrote:
> This patch returns an error number to quota_write in order for quota to handle
> it correctly.

We should return error number like __generic_file_write_iter, right? it
needs to return written bytes if we have written one page or more, otherwise
return error number feedbacked from write_begin.

So how about reverting 4f31d26b0c17 ("f2fs: return wrong error number on
f2fs_quota_write")?

Thanks,

> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
>  fs/f2fs/super.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 2feecf5e7f4c..840a0876005b 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -1397,8 +1397,11 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type,
>  
>  		err = a_ops->write_begin(NULL, mapping, off, tocopy, 0,
>  							&page, NULL);
> -		if (unlikely(err))
> +		if (unlikely(err)) {
> +			if (len == towrite)
> +				return err;
>  			break;
> +		}
>  
>  		kaddr = kmap_atomic(page);
>  		memcpy(kaddr + offset, data, tocopy);
> 

Re: [PATCH] f2fs: return error number for quota_write

[Jaegeuk Kim]

On 10/16, Chao Yu wrote:
> Hi Jaegeuk,
> 
> On 2017/10/13 7:15, Jaegeuk Kim wrote:
> > This patch returns an error number to quota_write in order for quota to handle
> > it correctly.
> 
> We should return error number like __generic_file_write_iter, right? it
> needs to return written bytes if we have written one page or more, otherwise
> return error number feedbacked from write_begin.
> 
> So how about reverting 4f31d26b0c17 ("f2fs: return wrong error number on
> f2fs_quota_write")?

I thought like that, but realized the code change is somewhat different between
them.

Thanks,

> 
> Thanks,
> 
> > 
> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> > ---
> >  fs/f2fs/super.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 2feecf5e7f4c..840a0876005b 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -1397,8 +1397,11 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type,
> >  
> >  		err = a_ops->write_begin(NULL, mapping, off, tocopy, 0,
> >  							&page, NULL);
> > -		if (unlikely(err))
> > +		if (unlikely(err)) {
> > +			if (len == towrite)
> > +				return err;
> >  			break;
> > +		}
> >  
> >  		kaddr = kmap_atomic(page);
> >  		memcpy(kaddr + offset, data, tocopy);
> > 

Re: [f2fs-dev] [PATCH] f2fs: return error number for quota_write

[Chao Yu]

On 2017/10/17 7:04, Jaegeuk Kim wrote:
> On 10/16, Chao Yu wrote:
>> Hi Jaegeuk,
>>
>> On 2017/10/13 7:15, Jaegeuk Kim wrote:
>>> This patch returns an error number to quota_write in order for quota to handle
>>> it correctly.
>>
>> We should return error number like __generic_file_write_iter, right? it
>> needs to return written bytes if we have written one page or more, otherwise
>> return error number feedbacked from write_begin.
>>
>> So how about reverting 4f31d26b0c17 ("f2fs: return wrong error number on
>> f2fs_quota_write")?
> 
> I thought like that, but realized the code change is somewhat different between
> them.

Hmm... main structure of codes here is copied from other file systems, is there
the same problem in *_quota_write of other file systems?

BTW, it looks making below judgment condition being useless.

	if (len == towrite)
		return 0;

Thanks,

> 
> Thanks,
> 
>>
>> Thanks,
>>
>>>
>>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
>>> ---
>>>  fs/f2fs/super.c | 5 ++++-
>>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>> index 2feecf5e7f4c..840a0876005b 100644
>>> --- a/fs/f2fs/super.c
>>> +++ b/fs/f2fs/super.c
>>> @@ -1397,8 +1397,11 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type,
>>>  
>>>  		err = a_ops->write_begin(NULL, mapping, off, tocopy, 0,
>>>  							&page, NULL);
>>> -		if (unlikely(err))
>>> +		if (unlikely(err)) {
>>> +			if (len == towrite)
>>> +				return err;
>>>  			break;
>>> +		}
>>>  
>>>  		kaddr = kmap_atomic(page);
>>>  		memcpy(kaddr + offset, data, tocopy);
>>>
> 
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> 

Re: [f2fs-dev] [PATCH] f2fs: return error number for quota_write

[Jaegeuk Kim]

On 10/17, Chao Yu wrote:
> 
> 
> On 2017/10/17 7:04, Jaegeuk Kim wrote:
> > On 10/16, Chao Yu wrote:
> >> Hi Jaegeuk,
> >>
> >> On 2017/10/13 7:15, Jaegeuk Kim wrote:
> >>> This patch returns an error number to quota_write in order for quota to handle
> >>> it correctly.
> >>
> >> We should return error number like __generic_file_write_iter, right? it
> >> needs to return written bytes if we have written one page or more, otherwise
> >> return error number feedbacked from write_begin.
> >>
> >> So how about reverting 4f31d26b0c17 ("f2fs: return wrong error number on
> >> f2fs_quota_write")?
> > 
> > I thought like that, but realized the code change is somewhat different between
> > them.
> 
> Hmm... main structure of codes here is copied from other file systems, is there
> the same problem in *_quota_write of other file systems?
> 
> BTW, it looks making below judgment condition being useless.
> 
> 	if (len == towrite)
> 		return 0;

We need this to avoid needless inode updates. :P

Thanks,

> 
> Thanks,
> 
> > 
> > Thanks,
> > 
> >>
> >> Thanks,
> >>
> >>>
> >>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> >>> ---
> >>>  fs/f2fs/super.c | 5 ++++-
> >>>  1 file changed, 4 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> >>> index 2feecf5e7f4c..840a0876005b 100644
> >>> --- a/fs/f2fs/super.c
> >>> +++ b/fs/f2fs/super.c
> >>> @@ -1397,8 +1397,11 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type,
> >>>  
> >>>  		err = a_ops->write_begin(NULL, mapping, off, tocopy, 0,
> >>>  							&page, NULL);
> >>> -		if (unlikely(err))
> >>> +		if (unlikely(err)) {
> >>> +			if (len == towrite)
> >>> +				return err;
> >>>  			break;
> >>> +		}
> >>>  
> >>>  		kaddr = kmap_atomic(page);
> >>>  		memcpy(kaddr + offset, data, tocopy);
> >>>
> > 
> > ------------------------------------------------------------------------------
> > Check out the vibrant tech community on one of the world's most
> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > Linux-f2fs-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > 

Re: [f2fs-dev] [PATCH] f2fs: return error number for quota_write

[Chao Yu]

On 2017/10/18 2:17, Jaegeuk Kim wrote:
> On 10/17, Chao Yu wrote:
>>
>>
>> On 2017/10/17 7:04, Jaegeuk Kim wrote:
>>> On 10/16, Chao Yu wrote:
>>>> Hi Jaegeuk,
>>>>
>>>> On 2017/10/13 7:15, Jaegeuk Kim wrote:
>>>>> This patch returns an error number to quota_write in order for quota to handle
>>>>> it correctly.
>>>>
>>>> We should return error number like __generic_file_write_iter, right? it
>>>> needs to return written bytes if we have written one page or more, otherwise
>>>> return error number feedbacked from write_begin.
>>>>
>>>> So how about reverting 4f31d26b0c17 ("f2fs: return wrong error number on
>>>> f2fs_quota_write")?
>>>
>>> I thought like that, but realized the code change is somewhat different between
>>> them.
>>
>> Hmm... main structure of codes here is copied from other file systems, is there
>> the same problem in *_quota_write of other file systems?
>>
>> BTW, it looks making below judgment condition being useless.
>>
>> 	if (len == towrite)
>> 		return 0;
> 
> We need this to avoid needless inode updates. :P

For err = 0 and len == towrite case, it more likes a bug of quota that passing
0 in @len.

:(, Oh, still didn't get that why there is difference in between reverting and
this fixing. Can you please explain more about this?

Thanks,

> 
> Thanks,
> 
>>
>> Thanks,
>>
>>>
>>> Thanks,
>>>
>>>>
>>>> Thanks,
>>>>
>>>>>
>>>>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
>>>>> ---
>>>>>  fs/f2fs/super.c | 5 ++++-
>>>>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>>>> index 2feecf5e7f4c..840a0876005b 100644
>>>>> --- a/fs/f2fs/super.c
>>>>> +++ b/fs/f2fs/super.c
>>>>> @@ -1397,8 +1397,11 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type,
>>>>>  
>>>>>  		err = a_ops->write_begin(NULL, mapping, off, tocopy, 0,
>>>>>  							&page, NULL);
>>>>> -		if (unlikely(err))
>>>>> +		if (unlikely(err)) {
>>>>> +			if (len == towrite)
>>>>> +				return err;
>>>>>  			break;
>>>>> +		}
>>>>>  
>>>>>  		kaddr = kmap_atomic(page);
>>>>>  		memcpy(kaddr + offset, data, tocopy);
>>>>>
>>>
>>> ------------------------------------------------------------------------------
>>> Check out the vibrant tech community on one of the world's most
>>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>>> _______________________________________________
>>> Linux-f2fs-devel mailing list
>>> Linux-f2fs-devel@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>>
> 
> .
> 

Re: [f2fs-dev] [PATCH] f2fs: return error number for quota_write

[Jaegeuk Kim]

On 10/18, Chao Yu wrote:
> On 2017/10/18 2:17, Jaegeuk Kim wrote:
> > On 10/17, Chao Yu wrote:
> >>
> >>
> >> On 2017/10/17 7:04, Jaegeuk Kim wrote:
> >>> On 10/16, Chao Yu wrote:
> >>>> Hi Jaegeuk,
> >>>>
> >>>> On 2017/10/13 7:15, Jaegeuk Kim wrote:
> >>>>> This patch returns an error number to quota_write in order for quota to handle
> >>>>> it correctly.
> >>>>
> >>>> We should return error number like __generic_file_write_iter, right? it
> >>>> needs to return written bytes if we have written one page or more, otherwise
> >>>> return error number feedbacked from write_begin.
> >>>>
> >>>> So how about reverting 4f31d26b0c17 ("f2fs: return wrong error number on
> >>>> f2fs_quota_write")?
> >>>
> >>> I thought like that, but realized the code change is somewhat different between
> >>> them.
> >>
> >> Hmm... main structure of codes here is copied from other file systems, is there
> >> the same problem in *_quota_write of other file systems?
> >>
> >> BTW, it looks making below judgment condition being useless.
> >>
> >> 	if (len == towrite)
> >> 		return 0;
> > 
> > We need this to avoid needless inode updates. :P
> 
> For err = 0 and len == towrite case, it more likes a bug of quota that passing
> 0 in @len.
> 
> :(, Oh, still didn't get that why there is difference in between reverting and
> this fixing. Can you please explain more about this?

Ah, right. Let me just revert the original patch. :)

Thanks,

Re: [f2fs-dev] [PATCH] f2fs: return error number for quota_write

[Chao Yu]

On 2017/10/20 3:08, Jaegeuk Kim wrote:
> On 10/18, Chao Yu wrote:
>> On 2017/10/18 2:17, Jaegeuk Kim wrote:
>>> On 10/17, Chao Yu wrote:
>>>>
>>>>
>>>> On 2017/10/17 7:04, Jaegeuk Kim wrote:
>>>>> On 10/16, Chao Yu wrote:
>>>>>> Hi Jaegeuk,
>>>>>>
>>>>>> On 2017/10/13 7:15, Jaegeuk Kim wrote:
>>>>>>> This patch returns an error number to quota_write in order for quota to handle
>>>>>>> it correctly.
>>>>>>
>>>>>> We should return error number like __generic_file_write_iter, right? it
>>>>>> needs to return written bytes if we have written one page or more, otherwise
>>>>>> return error number feedbacked from write_begin.
>>>>>>
>>>>>> So how about reverting 4f31d26b0c17 ("f2fs: return wrong error number on
>>>>>> f2fs_quota_write")?
>>>>>
>>>>> I thought like that, but realized the code change is somewhat different between
>>>>> them.
>>>>
>>>> Hmm... main structure of codes here is copied from other file systems, is there
>>>> the same problem in *_quota_write of other file systems?
>>>>
>>>> BTW, it looks making below judgment condition being useless.
>>>>
>>>> 	if (len == towrite)
>>>> 		return 0;
>>>
>>> We need this to avoid needless inode updates. :P
>>
>> For err = 0 and len == towrite case, it more likes a bug of quota that passing
>> 0 in @len.
>>
>> :(, Oh, still didn't get that why there is difference in between reverting and
>> this fixing. Can you please explain more about this?
> 
> Ah, right. Let me just revert the original patch. :)

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,

> 
> Thanks,
>