| Message ID | 20230505145829.74574-1-zhangpeng.00@bytedance.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] maple_tree: Make maple state reusable after mas_empty_area() | expand |
* Peng Zhang <zhangpeng.00@bytedance.com> [230505 10:59]: > Make mas->min and mas->max point to a node range instead of a leaf entry > range. This allows mas to still be usable after mas_empty_area() returns. > Users would get unexpected results from other operations on the maple > state after calling the affected function. > > Reported-by: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> > Reported-by: Tad <support@spotco.us> > Reported-by: Michael Keyes <mgkeyes@vigovproductions.net> > Link: https://lore.kernel.org/linux-mm/32f156ba80010fd97dbaf0a0cdfc84366608624d.camel@intel.com/ > Link: https://lore.kernel.org/linux-mm/e6108286ac025c268964a7ead3aab9899f9bc6e9.camel@spotco.us/ > Fixes: 54a611b60590 ("Maple Tree: add new data structure") > Cc: <Stable@vger.kernel.org> > Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> > --- > lib/maple_tree.c | 12 +++--------- > 1 file changed, 3 insertions(+), 9 deletions(-) > > diff --git a/lib/maple_tree.c b/lib/maple_tree.c > index 110a36479dced..8ebc43d4cc8c5 100644 > --- a/lib/maple_tree.c > +++ b/lib/maple_tree.c > @@ -5317,15 +5317,9 @@ int mas_empty_area(struct ma_state *mas, unsigned long min, > > mt = mte_node_type(mas->node); > pivots = ma_pivots(mas_mn(mas), mt); > - if (offset) > - mas->min = pivots[offset - 1] + 1; > - > - if (offset < mt_pivots[mt]) > - mas->max = pivots[offset]; > - > - if (mas->index < mas->min) > - mas->index = mas->min; > - > + min = mas_safe_min(mas, pivots, offset); > + if (mas->index < min) > + mas->index = min; > mas->last = mas->index + size - 1; > return 0; > } > -- > 2.20.1 >
On Fri, 2023-05-05 at 22:58 +0800, Peng Zhang wrote: > Make mas->min and mas->max point to a node range instead of a leaf > entry > range. This allows mas to still be usable after mas_empty_area() > returns. > Users would get unexpected results from other operations on the maple > state after calling the affected function. > > Reported-by: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> > Reported-by: Tad <support@spotco.us> > Reported-by: Michael Keyes <mgkeyes@vigovproductions.net> > Link: > https://lore.kernel.org/linux-mm/32f156ba80010fd97dbaf0a0cdfc84366608624d.camel@intel.com/ > Link: > https://lore.kernel.org/linux-mm/e6108286ac025c268964a7ead3aab9899f9bc6e9.camel@spotco.us/ > Fixes: 54a611b60590 ("Maple Tree: add new data structure") > Cc: <Stable@vger.kernel.org> > Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> > --- Yep, this also works for me. Thanks.
diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 110a36479dced..8ebc43d4cc8c5 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -5317,15 +5317,9 @@ int mas_empty_area(struct ma_state *mas, unsigned long min, mt = mte_node_type(mas->node); pivots = ma_pivots(mas_mn(mas), mt); - if (offset) - mas->min = pivots[offset - 1] + 1; - - if (offset < mt_pivots[mt]) - mas->max = pivots[offset]; - - if (mas->index < mas->min) - mas->index = mas->min; - + min = mas_safe_min(mas, pivots, offset); + if (mas->index < min) + mas->index = min; mas->last = mas->index + size - 1; return 0; }
Make mas->min and mas->max point to a node range instead of a leaf entry range. This allows mas to still be usable after mas_empty_area() returns. Users would get unexpected results from other operations on the maple state after calling the affected function. Reported-by: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> Reported-by: Tad <support@spotco.us> Reported-by: Michael Keyes <mgkeyes@vigovproductions.net> Link: https://lore.kernel.org/linux-mm/32f156ba80010fd97dbaf0a0cdfc84366608624d.camel@intel.com/ Link: https://lore.kernel.org/linux-mm/e6108286ac025c268964a7ead3aab9899f9bc6e9.camel@spotco.us/ Fixes: 54a611b60590 ("Maple Tree: add new data structure") Cc: <Stable@vger.kernel.org> Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> --- lib/maple_tree.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)