* Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx> [230426 00:15]:
>
> 在 2023/4/25 22:09, Liam R. Howlett 写道:
> > From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
> >
> > mas_parent_enum() is a simple wrapper for mte_parent_enum() which is
> > only called from that wrapper. Remove the wrapper and inline
> > mte_parent_enum() into mas_parent_enum().
> >
> > At the same time, clean up the bit masking of the root pointer since it
> > cannot be set by the time the bit masking occurs. Change the check on
> > the root bit to a WARN_ON(), and fix the verification code to not
> > trigger the WARN_ON() before checking if the node is root.
> >
> > Reported-by: Wei Yang <richard.weiyang@xxxxxxxxx>
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> > ---
> > lib/maple_tree.c | 28 +++++++++++-----------------
> > 1 file changed, 11 insertions(+), 17 deletions(-)
> >
> > diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> > index 9cf4fca42310c..ac0245dd88dad 100644
> > --- a/lib/maple_tree.c
> > +++ b/lib/maple_tree.c
> > @@ -428,25 +428,23 @@ static inline unsigned long mte_parent_slot_mask(unsigned long parent)
> > * mas_parent_enum() - Return the maple_type of the parent from the stored
> > * parent type.
> > * @mas: The maple state
> > - * @node: The maple_enode to extract the parent's enum
> > + * @enode: The maple_enode to extract the parent's enum
> > * Return: The node->parent maple_type
> > */
> > static inline
> > -enum maple_type mte_parent_enum(struct maple_enode *p_enode,
> > - struct maple_tree *mt)
> > +enum maple_type mas_parent_enum(struct ma_state *mas, struct maple_enode *enode)
>
> Do you think it's better to rename this function to mas_parent_type()?
> The meaning of enum is not obvious and there is already a similar
> function mte_node_type().
Yes, thanks. I'll make that change in v2.
>
> > {
> > unsigned long p_type;
> > - p_type = (unsigned long)p_enode;
> > - if (p_type & MAPLE_PARENT_ROOT)
> > - return 0; /* Validated in the caller. */
> > + p_type = (unsigned long)mte_to_node(enode)->parent;
> > + if (WARN_ON(p_type & MAPLE_PARENT_ROOT))
> > + return 0;
> > p_type &= MAPLE_NODE_MASK;
> > - p_type = p_type & ~(MAPLE_PARENT_ROOT | mte_parent_slot_mask(p_type));
> > -
> > + p_type &= ~mte_parent_slot_mask(p_type);
> > switch (p_type) {
> > case MAPLE_PARENT_RANGE64: /* or MAPLE_PARENT_ARANGE64 */
> > - if (mt_is_alloc(mt))
> > + if (mt_is_alloc(mas->tree))
> > return maple_arange_64;
> > return maple_range_64;
> > }
> > @@ -454,12 +452,6 @@ enum maple_type mte_parent_enum(struct maple_enode *p_enode,
> > return 0;
> > }
> > -static inline
> > -enum maple_type mas_parent_enum(struct ma_state *mas, struct maple_enode *enode)
> > -{
> > - return mte_parent_enum(ma_enode_ptr(mte_to_node(enode)->parent), mas->tree);
> > -}
> > -
> > /*
> > * mte_set_parent() - Set the parent node and encode the slot
> > * @enode: The encoded maple node.
> > @@ -7008,14 +7000,16 @@ static void mas_validate_parent_slot(struct ma_state *mas)
> > {
> > struct maple_node *parent;
> > struct maple_enode *node;
> > - enum maple_type p_type = mas_parent_enum(mas, mas->node);
> > - unsigned char p_slot = mte_parent_slot(mas->node);
> > + enum maple_type p_type;
> > + unsigned char p_slot;
> > void __rcu **slots;
> > int i;
> > if (mte_is_root(mas->node))
> > return;
> > + p_slot = mte_parent_slot(mas->node);
> > + p_type = mas_parent_enum(mas, mas->node);
> > parent = mte_parent(mas->node);
> > slots = ma_slots(parent, p_type);
> > MT_BUG_ON(mas->tree, mas_mn(mas) == parent);
