diff options
Diffstat (limited to '')
-rw-r--r-- | fs/btrfs/misc.h | 91 |
1 files changed, 90 insertions, 1 deletions
diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h index 72bab64ecf60..f9850edfd726 100644 --- a/fs/btrfs/misc.h +++ b/fs/btrfs/misc.h @@ -5,7 +5,8 @@ #include <linux/sched.h> #include <linux/wait.h> -#include <asm/div64.h> +#include <linux/math64.h> +#include <linux/rbtree.h> #define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len)) @@ -58,4 +59,92 @@ 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; +} + +/* + * Search @root from an entry that starts or comes after @bytenr. + * + * @root: the root to search. + * @bytenr: bytenr to search from. + * + * Return the rb_node that start at or after @bytenr. If there is no entry at + * or after @bytner return NULL. + */ +static inline struct rb_node *rb_simple_search_first(struct rb_root *root, + u64 bytenr) +{ + struct rb_node *node = root->rb_node, *ret = NULL; + struct rb_simple_node *entry, *ret_entry = NULL; + + while (node) { + entry = rb_entry(node, struct rb_simple_node, rb_node); + + if (bytenr < entry->bytenr) { + if (!ret || entry->bytenr < ret_entry->bytenr) { + ret = node; + ret_entry = entry; + } + + node = node->rb_left; + } else if (bytenr > entry->bytenr) { + node = node->rb_right; + } else { + return node; + } + } + + return ret; +} + +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 |