Let mtree_alloc_range() and mtree_alloc_rrange() use mas_empty_area()
and mas_empty_area_rev() respectively for allocation to reduce code
redundancy. And after doing this, we don't need to maintain two logically
identical codes to improve maintainability.
In fact, mtree_alloc_range/rrange() has some bugs. For example, when
dealing with min equals to max (mas_empty_area/area_rev() has been fixed),
the allocation will fail.
There are still some other bugs in it, I saw it with my naked eyes, but
I didn't test it, for example:
When mtree_alloc_range()->mas_alloc()->mas_awalk(), we set mas.index = min,
mas.last = max - size. However, mas_awalk() requires mas.index = min,
mas.last = max, which may lead to allocation failures.
Right now no users are using these two functions so the bug won't trigger,
but this might trigger in the future.
Also use mas_store_gfp() instead of mas_fill_gap() as I don't see any
difference between them.
After doing this, we no longer need the three functions
mas_fill_gap(), mas_alloc(), and mas_rev_alloc().
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Peng Zhang <[email protected]>
---
lib/maple_tree.c | 45 ++++++++++++---------------------------------
1 file changed, 12 insertions(+), 33 deletions(-)
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index aa55c914818a0..294d4c8668323 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -6362,32 +6362,20 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
{
int ret = 0;
- MA_STATE(mas, mt, min, max - size);
+ MA_STATE(mas, mt, 0, 0);
if (!mt_is_alloc(mt))
return -EINVAL;
if (WARN_ON_ONCE(mt_is_reserved(entry)))
return -EINVAL;
- if (min > max)
- return -EINVAL;
-
- if (max < size)
- return -EINVAL;
-
- if (!size)
- return -EINVAL;
-
mtree_lock(mt);
-retry:
- mas.offset = 0;
- mas.index = min;
- mas.last = max - size;
- ret = mas_alloc(&mas, entry, size, startp);
- if (mas_nomem(&mas, gfp))
- goto retry;
-
+ ret = mas_empty_area(&mas, min, max, size);
+ if (!ret)
+ ret = mas_store_gfp(&mas, entry, gfp);
mtree_unlock(mt);
+ if (!ret)
+ *startp = mas.index;
return ret;
}
EXPORT_SYMBOL(mtree_alloc_range);
@@ -6398,29 +6386,20 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
{
int ret = 0;
- MA_STATE(mas, mt, min, max - size);
+ MA_STATE(mas, mt, 0, 0);
if (!mt_is_alloc(mt))
return -EINVAL;
if (WARN_ON_ONCE(mt_is_reserved(entry)))
return -EINVAL;
- if (min >= max)
- return -EINVAL;
-
- if (max < size - 1)
- return -EINVAL;
-
- if (!size)
- return -EINVAL;
-
mtree_lock(mt);
-retry:
- ret = mas_rev_alloc(&mas, min, max, entry, size, startp);
- if (mas_nomem(&mas, gfp))
- goto retry;
-
+ ret = mas_empty_area_rev(&mas, min, max, size);
+ if (!ret)
+ ret = mas_store_gfp(&mas, entry, gfp);
mtree_unlock(mt);
+ if (!ret)
+ *startp = mas.index;
return ret;
}
EXPORT_SYMBOL(mtree_alloc_rrange);
--
2.20.1
* Peng Zhang <[email protected]> [230425 07:05]:
> Let mtree_alloc_range() and mtree_alloc_rrange() use mas_empty_area()
> and mas_empty_area_rev() respectively for allocation to reduce code
> redundancy. And after doing this, we don't need to maintain two logically
> identical codes to improve maintainability.
>
> In fact, mtree_alloc_range/rrange() has some bugs. For example, when
> dealing with min equals to max (mas_empty_area/area_rev() has been fixed),
> the allocation will fail.
> There are still some other bugs in it, I saw it with my naked eyes, but
> I didn't test it, for example:
> When mtree_alloc_range()->mas_alloc()->mas_awalk(), we set mas.index = min,
> mas.last = max - size. However, mas_awalk() requires mas.index = min,
> mas.last = max, which may lead to allocation failures.
Please don't re-state code in your commit messages.
Try to focus on what you did, and not why.
ie: Aligned mtree_alloc_range() to use the same internal function as
mas_empty_area().
>
> Right now no users are using these two functions so the bug won't trigger,
> but this might trigger in the future.
>
> Also use mas_store_gfp() instead of mas_fill_gap() as I don't see any
> difference between them.
Yeah, evolution of the code converged on the same design. Thanks for
seeing this.
>
> After doing this, we no longer need the three functions
> mas_fill_gap(), mas_alloc(), and mas_rev_alloc().
Let's just drop mtree_alloc_range() and mtree_alloc_rrange() and
whatever else you found here. They were planned to simplify the mmap
code allocations, but since there would need to be arch involvement
(coloring, etc) and alignment, etc; it is better to leave this job to
the mm code itself.
>
> Fixes: 54a611b60590 ("Maple Tree: add new data structure")
> Signed-off-by: Peng Zhang <[email protected]>
> ---
> lib/maple_tree.c | 45 ++++++++++++---------------------------------
> 1 file changed, 12 insertions(+), 33 deletions(-)
>
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index aa55c914818a0..294d4c8668323 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -6362,32 +6362,20 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
> {
> int ret = 0;
>
> - MA_STATE(mas, mt, min, max - size);
> + MA_STATE(mas, mt, 0, 0);
> if (!mt_is_alloc(mt))
> return -EINVAL;
>
> if (WARN_ON_ONCE(mt_is_reserved(entry)))
> return -EINVAL;
>
> - if (min > max)
> - return -EINVAL;
> -
> - if (max < size)
> - return -EINVAL;
> -
> - if (!size)
> - return -EINVAL;
> -
> mtree_lock(mt);
> -retry:
> - mas.offset = 0;
> - mas.index = min;
> - mas.last = max - size;
> - ret = mas_alloc(&mas, entry, size, startp);
> - if (mas_nomem(&mas, gfp))
> - goto retry;
> -
> + ret = mas_empty_area(&mas, min, max, size);
> + if (!ret)
> + ret = mas_store_gfp(&mas, entry, gfp);
> mtree_unlock(mt);
> + if (!ret)
> + *startp = mas.index;
> return ret;
> }
> EXPORT_SYMBOL(mtree_alloc_range);
> @@ -6398,29 +6386,20 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
> {
> int ret = 0;
>
> - MA_STATE(mas, mt, min, max - size);
> + MA_STATE(mas, mt, 0, 0);
> if (!mt_is_alloc(mt))
> return -EINVAL;
>
> if (WARN_ON_ONCE(mt_is_reserved(entry)))
> return -EINVAL;
>
> - if (min >= max)
> - return -EINVAL;
> -
> - if (max < size - 1)
> - return -EINVAL;
> -
> - if (!size)
> - return -EINVAL;
> -
> mtree_lock(mt);
> -retry:
> - ret = mas_rev_alloc(&mas, min, max, entry, size, startp);
> - if (mas_nomem(&mas, gfp))
> - goto retry;
> -
> + ret = mas_empty_area_rev(&mas, min, max, size);
> + if (!ret)
> + ret = mas_store_gfp(&mas, entry, gfp);
> mtree_unlock(mt);
> + if (!ret)
> + *startp = mas.index;
> return ret;
> }
> EXPORT_SYMBOL(mtree_alloc_rrange);
> --
> 2.20.1
>
在 2023/4/26 00:08, Liam R. Howlett 写道:
> * Peng Zhang <[email protected]> [230425 07:05]:
>> Let mtree_alloc_range() and mtree_alloc_rrange() use mas_empty_area()
>> and mas_empty_area_rev() respectively for allocation to reduce code
>> redundancy. And after doing this, we don't need to maintain two logically
>> identical codes to improve maintainability.
>>
>> In fact, mtree_alloc_range/rrange() has some bugs. For example, when
>> dealing with min equals to max (mas_empty_area/area_rev() has been fixed),
>> the allocation will fail.
>> There are still some other bugs in it, I saw it with my naked eyes, but
>> I didn't test it, for example:
>> When mtree_alloc_range()->mas_alloc()->mas_awalk(), we set mas.index = min,
>> mas.last = max - size. However, mas_awalk() requires mas.index = min,
>> mas.last = max, which may lead to allocation failures.
>
> Please don't re-state code in your commit messages.
>
> Try to focus on what you did, and not why.
>
> ie: Aligned mtree_alloc_range() to use the same internal function as
> mas_empty_area().
>
>>
>> Right now no users are using these two functions so the bug won't trigger,
>> but this might trigger in the future.
>>
>> Also use mas_store_gfp() instead of mas_fill_gap() as I don't see any
>> difference between them.
>
> Yeah, evolution of the code converged on the same design. Thanks for
> seeing this.
>
>>
>> After doing this, we no longer need the three functions
>> mas_fill_gap(), mas_alloc(), and mas_rev_alloc().
>
> Let's just drop mtree_alloc_range() and mtree_alloc_rrange() and
> whatever else you found here. They were planned to simplify the mmap
> code allocations, but since there would need to be arch involvement
> (coloring, etc) and alignment, etc; it is better to leave this job to
> the mm code itself.
Ok, I will remove some useless functions here.
But mtree_alloc_range() and mtree_alloc_rrange() really don't need to be
reserved? Because I don't know if there will be users using it in other
scenarios in the future.
Thank you for all your suggestions on this patch set, I will update them.
>
>>
>> Fixes: 54a611b60590 ("Maple Tree: add new data structure")
>> Signed-off-by: Peng Zhang <[email protected]>
>> ---
>> lib/maple_tree.c | 45 ++++++++++++---------------------------------
>> 1 file changed, 12 insertions(+), 33 deletions(-)
>>
>> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
>> index aa55c914818a0..294d4c8668323 100644
>> --- a/lib/maple_tree.c
>> +++ b/lib/maple_tree.c
>> @@ -6362,32 +6362,20 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
>> {
>> int ret = 0;
>>
>> - MA_STATE(mas, mt, min, max - size);
>> + MA_STATE(mas, mt, 0, 0);
>> if (!mt_is_alloc(mt))
>> return -EINVAL;
>>
>> if (WARN_ON_ONCE(mt_is_reserved(entry)))
>> return -EINVAL;
>>
>> - if (min > max)
>> - return -EINVAL;
>> -
>> - if (max < size)
>> - return -EINVAL;
>> -
>> - if (!size)
>> - return -EINVAL;
>> -
>> mtree_lock(mt);
>> -retry:
>> - mas.offset = 0;
>> - mas.index = min;
>> - mas.last = max - size;
>> - ret = mas_alloc(&mas, entry, size, startp);
>> - if (mas_nomem(&mas, gfp))
>> - goto retry;
>> -
>> + ret = mas_empty_area(&mas, min, max, size);
>> + if (!ret)
>> + ret = mas_store_gfp(&mas, entry, gfp);
>> mtree_unlock(mt);
>> + if (!ret)
>> + *startp = mas.index;
>> return ret;
>> }
>> EXPORT_SYMBOL(mtree_alloc_range);
>> @@ -6398,29 +6386,20 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
>> {
>> int ret = 0;
>>
>> - MA_STATE(mas, mt, min, max - size);
>> + MA_STATE(mas, mt, 0, 0);
>> if (!mt_is_alloc(mt))
>> return -EINVAL;
>>
>> if (WARN_ON_ONCE(mt_is_reserved(entry)))
>> return -EINVAL;
>>
>> - if (min >= max)
>> - return -EINVAL;
>> -
>> - if (max < size - 1)
>> - return -EINVAL;
>> -
>> - if (!size)
>> - return -EINVAL;
>> -
>> mtree_lock(mt);
>> -retry:
>> - ret = mas_rev_alloc(&mas, min, max, entry, size, startp);
>> - if (mas_nomem(&mas, gfp))
>> - goto retry;
>> -
>> + ret = mas_empty_area_rev(&mas, min, max, size);
>> + if (!ret)
>> + ret = mas_store_gfp(&mas, entry, gfp);
>> mtree_unlock(mt);
>> + if (!ret)
>> + *startp = mas.index;
>> return ret;
>> }
>> EXPORT_SYMBOL(mtree_alloc_rrange);
>> --
>> 2.20.1
>>
* Peng Zhang <[email protected]> [230426 08:34]:
>
>
> 在 2023/4/26 00:08, Liam R. Howlett 写道:
> > * Peng Zhang <[email protected]> [230425 07:05]:
> > > Let mtree_alloc_range() and mtree_alloc_rrange() use mas_empty_area()
> > > and mas_empty_area_rev() respectively for allocation to reduce code
> > > redundancy. And after doing this, we don't need to maintain two logically
> > > identical codes to improve maintainability.
> > >
> > > In fact, mtree_alloc_range/rrange() has some bugs. For example, when
> > > dealing with min equals to max (mas_empty_area/area_rev() has been fixed),
> > > the allocation will fail.
> > > There are still some other bugs in it, I saw it with my naked eyes, but
> > > I didn't test it, for example:
> > > When mtree_alloc_range()->mas_alloc()->mas_awalk(), we set mas.index = min,
> > > mas.last = max - size. However, mas_awalk() requires mas.index = min,
> > > mas.last = max, which may lead to allocation failures.
> >
> > Please don't re-state code in your commit messages.
> >
> > Try to focus on what you did, and not why.
> >
> > ie: Aligned mtree_alloc_range() to use the same internal function as
> > mas_empty_area().
> >
> > >
> > > Right now no users are using these two functions so the bug won't trigger,
> > > but this might trigger in the future.
> > >
> > > Also use mas_store_gfp() instead of mas_fill_gap() as I don't see any
> > > difference between them.
> >
> > Yeah, evolution of the code converged on the same design. Thanks for
> > seeing this.
> >
> > >
> > > After doing this, we no longer need the three functions
> > > mas_fill_gap(), mas_alloc(), and mas_rev_alloc().
> >
> > Let's just drop mtree_alloc_range() and mtree_alloc_rrange() and
> > whatever else you found here. They were planned to simplify the mmap
> > code allocations, but since there would need to be arch involvement
> > (coloring, etc) and alignment, etc; it is better to leave this job to
> > the mm code itself.
> Ok, I will remove some useless functions here.
> But mtree_alloc_range() and mtree_alloc_rrange() really don't need to be
> reserved? Because I don't know if there will be users using it in other
> scenarios in the future.
As you showed, a lot of the code is now the same elsewhere, so it
wouldn't take much to make a version of this outside of the tree if
someone needs the functionality.
>
> Thank you for all your suggestions on this patch set, I will update them.
> >
> > >
> > > Fixes: 54a611b60590 ("Maple Tree: add new data structure")
> > > Signed-off-by: Peng Zhang <[email protected]>
> > > ---
> > > lib/maple_tree.c | 45 ++++++++++++---------------------------------
> > > 1 file changed, 12 insertions(+), 33 deletions(-)
> > >
> > > diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> > > index aa55c914818a0..294d4c8668323 100644
> > > --- a/lib/maple_tree.c
> > > +++ b/lib/maple_tree.c
> > > @@ -6362,32 +6362,20 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
> > > {
> > > int ret = 0;
> > > - MA_STATE(mas, mt, min, max - size);
> > > + MA_STATE(mas, mt, 0, 0);
> > > if (!mt_is_alloc(mt))
> > > return -EINVAL;
> > > if (WARN_ON_ONCE(mt_is_reserved(entry)))
> > > return -EINVAL;
> > > - if (min > max)
> > > - return -EINVAL;
> > > -
> > > - if (max < size)
> > > - return -EINVAL;
> > > -
> > > - if (!size)
> > > - return -EINVAL;
> > > -
> > > mtree_lock(mt);
> > > -retry:
> > > - mas.offset = 0;
> > > - mas.index = min;
> > > - mas.last = max - size;
> > > - ret = mas_alloc(&mas, entry, size, startp);
> > > - if (mas_nomem(&mas, gfp))
> > > - goto retry;
> > > -
> > > + ret = mas_empty_area(&mas, min, max, size);
> > > + if (!ret)
> > > + ret = mas_store_gfp(&mas, entry, gfp);
> > > mtree_unlock(mt);
> > > + if (!ret)
> > > + *startp = mas.index;
> > > return ret;
> > > }
> > > EXPORT_SYMBOL(mtree_alloc_range);
> > > @@ -6398,29 +6386,20 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
> > > {
> > > int ret = 0;
> > > - MA_STATE(mas, mt, min, max - size);
> > > + MA_STATE(mas, mt, 0, 0);
> > > if (!mt_is_alloc(mt))
> > > return -EINVAL;
> > > if (WARN_ON_ONCE(mt_is_reserved(entry)))
> > > return -EINVAL;
> > > - if (min >= max)
> > > - return -EINVAL;
> > > -
> > > - if (max < size - 1)
> > > - return -EINVAL;
> > > -
> > > - if (!size)
> > > - return -EINVAL;
> > > -
> > > mtree_lock(mt);
> > > -retry:
> > > - ret = mas_rev_alloc(&mas, min, max, entry, size, startp);
> > > - if (mas_nomem(&mas, gfp))
> > > - goto retry;
> > > -
> > > + ret = mas_empty_area_rev(&mas, min, max, size);
> > > + if (!ret)
> > > + ret = mas_store_gfp(&mas, entry, gfp);
> > > mtree_unlock(mt);
> > > + if (!ret)
> > > + *startp = mas.index;
> > > return ret;
> > > }
> > > EXPORT_SYMBOL(mtree_alloc_rrange);
> > > --
> > > 2.20.1
> > >