libceph: make DEFINE_RB_* helpers more general

Initially for ceph_pg_mapping, ceph_spg_mapping and ceph_hobject_id,
compared with ceph_pg_compare(), ceph_spg_compare() and hoid_compare()
respectively.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 37 insertions, 12 deletions

diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
index 3229ae6c7846..8a79587e1317 100644
--- a/include/linux/ceph/libceph.h
+++ b/include/linux/ceph/libceph.h
@@ -184,10 +184,11 @@ static inline int calc_pages_for(u64 off, u64 len)
                 (off >> PAGE_SHIFT);
 }
 
-/*
- * These are not meant to be generic - an integer key is assumed.
- */
-#define DEFINE_RB_INSDEL_FUNCS(name, type, keyfld, nodefld)             \
+#define RB_BYVAL(a)      (a)
+#define RB_BYPTR(a)      (&(a))
+#define RB_CMP3WAY(a, b) ((a) < (b) ? -1 : (a) > (b))
+
+#define DEFINE_RB_INSDEL_FUNCS2(name, type, keyfld, cmpexp, keyexp, nodefld) \
 static void insert_##name(struct rb_root *root, type *t)                \
 {                                                                       \
         struct rb_node **n = &root->rb_node;                            \
@@ -197,11 +198,13 @@ static void insert_##name(struct rb_root *root, type *t)		\
                                                                         \
         while (*n) {                                                    \
                 type *cur = rb_entry(*n, type, nodefld);                \
+                int cmp;                                                \
                                                                         \
                 parent = *n;                                            \
-                if (t->keyfld < cur->keyfld)                            \
+                cmp = cmpexp(keyexp(t->keyfld), keyexp(cur->keyfld));   \
+                if (cmp < 0)                                            \
                         n = &(*n)->rb_left;                             \
-                else if (t->keyfld > cur->keyfld)                       \
+                else if (cmp > 0)                                       \
                         n = &(*n)->rb_right;                            \
                 else                                                    \
                         BUG();                                          \
@@ -217,19 +220,24 @@ static void erase_##name(struct rb_root *root, type *t)			\
         RB_CLEAR_NODE(&t->nodefld);                                     \
 }
 
-#define DEFINE_RB_LOOKUP_FUNC(name, type, keyfld, nodefld)              \
-extern type __lookup_##name##_key;                                      \
-static type *lookup_##name(struct rb_root *root,                        \
-                           typeof(__lookup_##name##_key.keyfld) key)    \
+/*
+ * @lookup_param_type is a parameter and not constructed from (@type,
+ * @keyfld) with typeof() because adding const is too unwieldy.
+ */
+#define DEFINE_RB_LOOKUP_FUNC2(name, type, keyfld, cmpexp, keyexp,      \
+                               lookup_param_type, nodefld)              \
+static type *lookup_##name(struct rb_root *root, lookup_param_type key) \
 {                                                                       \
         struct rb_node *n = root->rb_node;                              \
                                                                         \
         while (n) {                                                     \
                 type *cur = rb_entry(n, type, nodefld);                 \
+                int cmp;                                                \
                                                                         \
-                if (key < cur->keyfld)                                  \
+                cmp = cmpexp(key, keyexp(cur->keyfld));                 \
+                if (cmp < 0)                                            \
                         n = n->rb_left;                                 \
-                else if (key > cur->keyfld)                             \
+                else if (cmp > 0)                                       \
                         n = n->rb_right;                                \
                 else                                                    \
                         return cur;                                     \
@@ -238,6 +246,23 @@ static type *lookup_##name(struct rb_root *root,			\
         return NULL;                                                    \
 }
 
+#define DEFINE_RB_FUNCS2(name, type, keyfld, cmpexp, keyexp,            \
+                         lookup_param_type, nodefld)                    \
+DEFINE_RB_INSDEL_FUNCS2(name, type, keyfld, cmpexp, keyexp, nodefld)    \
+DEFINE_RB_LOOKUP_FUNC2(name, type, keyfld, cmpexp, keyexp,              \
+                       lookup_param_type, nodefld)
+
+/*
+ * Shorthands for integer keys.
+ */
+#define DEFINE_RB_INSDEL_FUNCS(name, type, keyfld, nodefld)             \
+DEFINE_RB_INSDEL_FUNCS2(name, type, keyfld, RB_CMP3WAY, RB_BYVAL, nodefld)
+
+#define DEFINE_RB_LOOKUP_FUNC(name, type, keyfld, nodefld)              \
+extern type __lookup_##name##_key;                                      \
+DEFINE_RB_LOOKUP_FUNC2(name, type, keyfld, RB_CMP3WAY, RB_BYVAL,        \
+                       typeof(__lookup_##name##_key.keyfld), nodefld)
+
 #define DEFINE_RB_FUNCS(name, type, keyfld, nodefld)                    \
 DEFINE_RB_INSDEL_FUNCS(name, type, keyfld, nodefld)                     \
 DEFINE_RB_LOOKUP_FUNC(name, type, keyfld, nodefld)