[PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx

[PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx

[Yue Hu]

From: Yue Hu <huyue2@yulong.com>

Currently, the whole indexes will only be compacted 4B if
compacted_4b_initial > totalidx. So, the calculated compacted_2b
is worthless for that case. It may waste CPU resources.

No need to update compacted_4b_initial as mkfs since it's used to
fulfill the alignment of the 1st compacted_2b pack and would handle
the case above.

We also need to clarify compacted_4b_end here. It's used for the
last lclusters which aren't fitted in the previous compacted_2b
packs.

Some messages are from Xiang.

Signed-off-by: Yue Hu <huyue2@yulong.com>
---
 fs/erofs/zmap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 9fb98d8..aeed404 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -369,7 +369,8 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
 	if (compacted_4b_initial == 32 / 4)
 		compacted_4b_initial = 0;
 
-	if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
+	if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
+	    compacted_4b_initial <= totalidx) {
 		compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
 	else
 		compacted_2b = 0;
-- 
1.9.1

Re: [PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx

[Gao Xiang]

On Tue, Sep 14, 2021 at 11:59:15AM +0800, Yue Hu wrote:
> From: Yue Hu <huyue2@yulong.com>
> 
> Currently, the whole indexes will only be compacted 4B if
> compacted_4b_initial > totalidx. So, the calculated compacted_2b
> is worthless for that case. It may waste CPU resources.
> 
> No need to update compacted_4b_initial as mkfs since it's used to
> fulfill the alignment of the 1st compacted_2b pack and would handle
> the case above.
> 
> We also need to clarify compacted_4b_end here. It's used for the
> last lclusters which aren't fitted in the previous compacted_2b
> packs.
> 
> Some messages are from Xiang.
> 
> Signed-off-by: Yue Hu <huyue2@yulong.com>

Looks good to me,
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>

(although I think the subject title would be better changed into
 "clear compacted_2b if compacted_4b_initial > totalidx"
 since 'fix'-likewise words could trigger some AI bot for stable
 kernel backporting..)

Thanks,
Gao Xiang

> ---
>  fs/erofs/zmap.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> index 9fb98d8..aeed404 100644
> --- a/fs/erofs/zmap.c
> +++ b/fs/erofs/zmap.c
> @@ -369,7 +369,8 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
>  	if (compacted_4b_initial == 32 / 4)
>  		compacted_4b_initial = 0;
>  
> -	if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> +	if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
> +	    compacted_4b_initial <= totalidx) {
>  		compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
>  	else
>  		compacted_2b = 0;
> -- 
> 1.9.1

Re: [PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx

[Yue Hu]

On Tue, 14 Sep 2021 12:37:14 +0800
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:

> On Tue, Sep 14, 2021 at 11:59:15AM +0800, Yue Hu wrote:
> > From: Yue Hu <huyue2@yulong.com>
> > 
> > Currently, the whole indexes will only be compacted 4B if
> > compacted_4b_initial > totalidx. So, the calculated compacted_2b
> > is worthless for that case. It may waste CPU resources.
> > 
> > No need to update compacted_4b_initial as mkfs since it's used to
> > fulfill the alignment of the 1st compacted_2b pack and would handle
> > the case above.
> > 
> > We also need to clarify compacted_4b_end here. It's used for the
> > last lclusters which aren't fitted in the previous compacted_2b
> > packs.
> > 
> > Some messages are from Xiang.
> > 
> > Signed-off-by: Yue Hu <huyue2@yulong.com>  
> 
> Looks good to me,
> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> 
> (although I think the subject title would be better changed into
>  "clear compacted_2b if compacted_4b_initial > totalidx"

Yeah, 'clear' is much better for this change.

Thanks.

>  since 'fix'-likewise words could trigger some AI bot for stable
>  kernel backporting..)
> 
> Thanks,
> Gao Xiang
> 
> > ---
> >  fs/erofs/zmap.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> > index 9fb98d8..aeed404 100644
> > --- a/fs/erofs/zmap.c
> > +++ b/fs/erofs/zmap.c
> > @@ -369,7 +369,8 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> >  	if (compacted_4b_initial == 32 / 4)
> >  		compacted_4b_initial = 0;
> >  
> > -	if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > +	if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
> > +	    compacted_4b_initial <= totalidx) {
> >  		compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
> >  	else
> >  		compacted_2b = 0;
> > -- 
> > 1.9.1  

Re: [PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx

[Gao Xiang]

On Tue, Sep 14, 2021 at 12:57:48PM +0800, Yue Hu wrote:
> On Tue, 14 Sep 2021 12:37:14 +0800
> Gao Xiang <hsiangkao@linux.alibaba.com> wrote:
> 
> > On Tue, Sep 14, 2021 at 11:59:15AM +0800, Yue Hu wrote:
> > > From: Yue Hu <huyue2@yulong.com>
> > > 
> > > Currently, the whole indexes will only be compacted 4B if
> > > compacted_4b_initial > totalidx. So, the calculated compacted_2b
> > > is worthless for that case. It may waste CPU resources.
> > > 
> > > No need to update compacted_4b_initial as mkfs since it's used to
> > > fulfill the alignment of the 1st compacted_2b pack and would handle
> > > the case above.
> > > 
> > > We also need to clarify compacted_4b_end here. It's used for the
> > > last lclusters which aren't fitted in the previous compacted_2b
> > > packs.
> > > 
> > > Some messages are from Xiang.
> > > 
> > > Signed-off-by: Yue Hu <huyue2@yulong.com>  
> > 
> > Looks good to me,
> > Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> > 
> > (although I think the subject title would be better changed into
> >  "clear compacted_2b if compacted_4b_initial > totalidx"
> 
> Yeah, 'clear' is much better for this change.

Ok, I will update this when later applying.

Thanks,
Gao Xiang

> 
> Thanks.
> 
> >  since 'fix'-likewise words could trigger some AI bot for stable
> >  kernel backporting..)
> > 
> > Thanks,
> > Gao Xiang
> > 
> > > ---
> > >  fs/erofs/zmap.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> > > index 9fb98d8..aeed404 100644
> > > --- a/fs/erofs/zmap.c
> > > +++ b/fs/erofs/zmap.c
> > > @@ -369,7 +369,8 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> > >  	if (compacted_4b_initial == 32 / 4)
> > >  		compacted_4b_initial = 0;
> > >  
> > > -	if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > > +	if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
> > > +	    compacted_4b_initial <= totalidx) {
> > >  		compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
> > >  	else
> > >  		compacted_2b = 0;
> > > -- 
> > > 1.9.1  

Re: [PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx

[Gao Xiang]

On Tue, Sep 14, 2021 at 12:57:48PM +0800, Yue Hu wrote:
> On Tue, 14 Sep 2021 12:37:14 +0800
> Gao Xiang <hsiangkao@linux.alibaba.com> wrote:
> 
> > On Tue, Sep 14, 2021 at 11:59:15AM +0800, Yue Hu wrote:
> > > From: Yue Hu <huyue2@yulong.com>
> > > 
> > > Currently, the whole indexes will only be compacted 4B if
> > > compacted_4b_initial > totalidx. So, the calculated compacted_2b
> > > is worthless for that case. It may waste CPU resources.
> > > 
> > > No need to update compacted_4b_initial as mkfs since it's used to
> > > fulfill the alignment of the 1st compacted_2b pack and would handle
> > > the case above.
> > > 
> > > We also need to clarify compacted_4b_end here. It's used for the
> > > last lclusters which aren't fitted in the previous compacted_2b
> > > packs.
> > > 
> > > Some messages are from Xiang.
> > > 
> > > Signed-off-by: Yue Hu <huyue2@yulong.com>  
> > 
> > Looks good to me,
> > Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> > 
> > (although I think the subject title would be better changed into
> >  "clear compacted_2b if compacted_4b_initial > totalidx"
> 
> Yeah, 'clear' is much better for this change.
> 
> Thanks.
> 
> >  since 'fix'-likewise words could trigger some AI bot for stable
> >  kernel backporting..)
> > 
> > Thanks,
> > Gao Xiang
> > 
> > > ---
> > >  fs/erofs/zmap.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> > > index 9fb98d8..aeed404 100644
> > > --- a/fs/erofs/zmap.c
> > > +++ b/fs/erofs/zmap.c
> > > @@ -369,7 +369,8 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> > >  	if (compacted_4b_initial == 32 / 4)
> > >  		compacted_4b_initial = 0;
> > >  
> > > -	if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > > +	if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
> > > +	    compacted_4b_initial <= totalidx) {

btw, I've fixed up the build error due to redundant brace '{' when
applying...

Thanks,
Gao Xiang

> > >  		compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
> > >  	else
> > >  		compacted_2b = 0;
> > > -- 
> > > 1.9.1  

Re: [PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx

[Yue Hu]

On Thu, 23 Sep 2021 19:49:42 +0800
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:

> On Tue, Sep 14, 2021 at 12:57:48PM +0800, Yue Hu wrote:
> > On Tue, 14 Sep 2021 12:37:14 +0800
> > Gao Xiang <hsiangkao@linux.alibaba.com> wrote:
> >   
> > > On Tue, Sep 14, 2021 at 11:59:15AM +0800, Yue Hu wrote:  
> > > > From: Yue Hu <huyue2@yulong.com>
> > > > 
> > > > Currently, the whole indexes will only be compacted 4B if
> > > > compacted_4b_initial > totalidx. So, the calculated compacted_2b
> > > > is worthless for that case. It may waste CPU resources.
> > > > 
> > > > No need to update compacted_4b_initial as mkfs since it's used to
> > > > fulfill the alignment of the 1st compacted_2b pack and would handle
> > > > the case above.
> > > > 
> > > > We also need to clarify compacted_4b_end here. It's used for the
> > > > last lclusters which aren't fitted in the previous compacted_2b
> > > > packs.
> > > > 
> > > > Some messages are from Xiang.
> > > > 
> > > > Signed-off-by: Yue Hu <huyue2@yulong.com>    
> > > 
> > > Looks good to me,
> > > Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> > > 
> > > (although I think the subject title would be better changed into
> > >  "clear compacted_2b if compacted_4b_initial > totalidx"  
> > 
> > Yeah, 'clear' is much better for this change.
> > 
> > Thanks.
> >   
> > >  since 'fix'-likewise words could trigger some AI bot for stable
> > >  kernel backporting..)
> > > 
> > > Thanks,
> > > Gao Xiang
> > >   
> > > > ---
> > > >  fs/erofs/zmap.c | 3 ++-
> > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> > > > index 9fb98d8..aeed404 100644
> > > > --- a/fs/erofs/zmap.c
> > > > +++ b/fs/erofs/zmap.c
> > > > @@ -369,7 +369,8 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> > > >  	if (compacted_4b_initial == 32 / 4)
> > > >  		compacted_4b_initial = 0;
> > > >  
> > > > -	if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > > > +	if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
> > > > +	    compacted_4b_initial <= totalidx) {  
> 
> btw, I've fixed up the build error due to redundant brace '{' when

Thanks.

> applying...
> 
> Thanks,
> Gao Xiang
> 
> > > >  		compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
> > > >  	else
> > > >  		compacted_2b = 0;
> > > > -- 
> > > > 1.9.1    

Re: [PATCH] erofs: fix compacted_2b if compacted_4b_initial > totalidx

[Chao Yu]

On 2021/9/23 19:49, Gao Xiang wrote:
> On Tue, Sep 14, 2021 at 12:57:48PM +0800, Yue Hu wrote:
>> On Tue, 14 Sep 2021 12:37:14 +0800
>> Gao Xiang <hsiangkao@linux.alibaba.com> wrote:
>>
>>> On Tue, Sep 14, 2021 at 11:59:15AM +0800, Yue Hu wrote:
>>>> From: Yue Hu <huyue2@yulong.com>
>>>>
>>>> Currently, the whole indexes will only be compacted 4B if
>>>> compacted_4b_initial > totalidx. So, the calculated compacted_2b
>>>> is worthless for that case. It may waste CPU resources.
>>>>
>>>> No need to update compacted_4b_initial as mkfs since it's used to
>>>> fulfill the alignment of the 1st compacted_2b pack and would handle
>>>> the case above.
>>>>
>>>> We also need to clarify compacted_4b_end here. It's used for the
>>>> last lclusters which aren't fitted in the previous compacted_2b
>>>> packs.
>>>>
>>>> Some messages are from Xiang.
>>>>
>>>> Signed-off-by: Yue Hu <huyue2@yulong.com>
>>>
>>> Looks good to me,
>>> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
>>>
>>> (although I think the subject title would be better changed into
>>>   "clear compacted_2b if compacted_4b_initial > totalidx"
>>
>> Yeah, 'clear' is much better for this change.
>>
>> Thanks.
>>
>>>   since 'fix'-likewise words could trigger some AI bot for stable
>>>   kernel backporting..)
>>>
>>> Thanks,
>>> Gao Xiang
>>>
>>>> ---
>>>>   fs/erofs/zmap.c | 3 ++-
>>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
>>>> index 9fb98d8..aeed404 100644
>>>> --- a/fs/erofs/zmap.c
>>>> +++ b/fs/erofs/zmap.c
>>>> @@ -369,7 +369,8 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
>>>>   	if (compacted_4b_initial == 32 / 4)
>>>>   		compacted_4b_initial = 0;
>>>>   
>>>> -	if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
>>>> +	if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
>>>> +	    compacted_4b_initial <= totalidx) {
> 
> btw, I've fixed up the build error due to redundant brace '{' when
> applying...

It looks good to me after above fix.

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,