Commit f4b477c4 authored by Artem Bityutskiy's avatar Artem Bityutskiy Committed by Linus Torvalds

rbtree: add const qualifier to some functions

The 'rb_first()', 'rb_last()', 'rb_next()' and 'rb_prev()' calls
take a pointer to an RB node or RB root. They do not change the
pointed objects, so add a 'const' qualifier in order to make life
of the users of these functions easier.

Indeed, if I have my own constant pointer &const struct my_type *p,
and I call 'rb_next(&p->rb)', I get a GCC warning:

warning: passing argument 1 of ‘rb_next’ discards qualifiers from pointer target type
Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cfce41a6
...@@ -140,10 +140,10 @@ extern void rb_insert_color(struct rb_node *, struct rb_root *); ...@@ -140,10 +140,10 @@ extern void rb_insert_color(struct rb_node *, struct rb_root *);
extern void rb_erase(struct rb_node *, struct rb_root *); extern void rb_erase(struct rb_node *, struct rb_root *);
/* Find logical next and previous nodes in a tree */ /* Find logical next and previous nodes in a tree */
extern struct rb_node *rb_next(struct rb_node *); extern struct rb_node *rb_next(const struct rb_node *);
extern struct rb_node *rb_prev(struct rb_node *); extern struct rb_node *rb_prev(const struct rb_node *);
extern struct rb_node *rb_first(struct rb_root *); extern struct rb_node *rb_first(const struct rb_root *);
extern struct rb_node *rb_last(struct rb_root *); extern struct rb_node *rb_last(const struct rb_root *);
/* Fast replacement of a single node without remove/rebalance/add/rebalance */ /* Fast replacement of a single node without remove/rebalance/add/rebalance */
extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
......
...@@ -292,7 +292,7 @@ EXPORT_SYMBOL(rb_erase); ...@@ -292,7 +292,7 @@ EXPORT_SYMBOL(rb_erase);
/* /*
* This function returns the first node (in sort order) of the tree. * This function returns the first node (in sort order) of the tree.
*/ */
struct rb_node *rb_first(struct rb_root *root) struct rb_node *rb_first(const struct rb_root *root)
{ {
struct rb_node *n; struct rb_node *n;
...@@ -305,7 +305,7 @@ struct rb_node *rb_first(struct rb_root *root) ...@@ -305,7 +305,7 @@ struct rb_node *rb_first(struct rb_root *root)
} }
EXPORT_SYMBOL(rb_first); EXPORT_SYMBOL(rb_first);
struct rb_node *rb_last(struct rb_root *root) struct rb_node *rb_last(const struct rb_root *root)
{ {
struct rb_node *n; struct rb_node *n;
...@@ -318,7 +318,7 @@ struct rb_node *rb_last(struct rb_root *root) ...@@ -318,7 +318,7 @@ struct rb_node *rb_last(struct rb_root *root)
} }
EXPORT_SYMBOL(rb_last); EXPORT_SYMBOL(rb_last);
struct rb_node *rb_next(struct rb_node *node) struct rb_node *rb_next(const struct rb_node *node)
{ {
struct rb_node *parent; struct rb_node *parent;
...@@ -331,7 +331,7 @@ struct rb_node *rb_next(struct rb_node *node) ...@@ -331,7 +331,7 @@ struct rb_node *rb_next(struct rb_node *node)
node = node->rb_right; node = node->rb_right;
while (node->rb_left) while (node->rb_left)
node=node->rb_left; node=node->rb_left;
return node; return (struct rb_node *)node;
} }
/* No right-hand children. Everything down and left is /* No right-hand children. Everything down and left is
...@@ -347,7 +347,7 @@ struct rb_node *rb_next(struct rb_node *node) ...@@ -347,7 +347,7 @@ struct rb_node *rb_next(struct rb_node *node)
} }
EXPORT_SYMBOL(rb_next); EXPORT_SYMBOL(rb_next);
struct rb_node *rb_prev(struct rb_node *node) struct rb_node *rb_prev(const struct rb_node *node)
{ {
struct rb_node *parent; struct rb_node *parent;
...@@ -360,7 +360,7 @@ struct rb_node *rb_prev(struct rb_node *node) ...@@ -360,7 +360,7 @@ struct rb_node *rb_prev(struct rb_node *node)
node = node->rb_left; node = node->rb_left;
while (node->rb_right) while (node->rb_right)
node=node->rb_right; node=node->rb_right;
return node; return (struct rb_node *)node;
} }
/* No left-hand children. Go up till we find an ancestor which /* No left-hand children. Go up till we find an ancestor which
......
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