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-rw-r--r--fs/btrfs/misc.h54
1 files changed, 54 insertions, 0 deletions
diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h
index 72bab64ecf60..6461ebc3a1c1 100644
--- a/fs/btrfs/misc.h
+++ b/fs/btrfs/misc.h
@@ -6,6 +6,7 @@
#include <linux/sched.h>
#include <linux/wait.h>
#include <asm/div64.h>
+#include <linux/rbtree.h>
#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
@@ -58,4 +59,57 @@ static inline bool has_single_bit_set(u64 n)
return is_power_of_two_u64(n);
}
+/*
+ * Simple bytenr based rb_tree relate structures
+ *
+ * Any structure wants to use bytenr as single search index should have their
+ * structure start with these members.
+ */
+struct rb_simple_node {
+ struct rb_node rb_node;
+ u64 bytenr;
+};
+
+static inline struct rb_node *rb_simple_search(struct rb_root *root, u64 bytenr)
+{
+ struct rb_node *node = root->rb_node;
+ struct rb_simple_node *entry;
+
+ while (node) {
+ entry = rb_entry(node, struct rb_simple_node, rb_node);
+
+ if (bytenr < entry->bytenr)
+ node = node->rb_left;
+ else if (bytenr > entry->bytenr)
+ node = node->rb_right;
+ else
+ return node;
+ }
+ return NULL;
+}
+
+static inline struct rb_node *rb_simple_insert(struct rb_root *root, u64 bytenr,
+ struct rb_node *node)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct rb_simple_node *entry;
+
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct rb_simple_node, rb_node);
+
+ if (bytenr < entry->bytenr)
+ p = &(*p)->rb_left;
+ else if (bytenr > entry->bytenr)
+ p = &(*p)->rb_right;
+ else
+ return parent;
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+ return NULL;
+}
+
#endif