#include <linux/slab.h>
#include <linux/module.h>
#include <linux/spinlock.h>
-#include <linux/version.h>
#include <linux/hardirq.h>
#include "extent_map.h"
static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
struct rb_node *node)
{
- struct rb_node ** p = &root->rb_node;
- struct rb_node * parent = NULL;
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
struct extent_map *entry;
- while(*p) {
+ while (*p) {
parent = *p;
entry = rb_entry(parent, struct extent_map, rb_node);
return NULL;
}
+/*
+ * search through the tree for an extent_map with a given offset. If
+ * it can't be found, try to find some neighboring extents
+ */
static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
struct rb_node **prev_ret,
struct rb_node **next_ret)
{
- struct rb_node * n = root->rb_node;
+ struct rb_node *n = root->rb_node;
struct rb_node *prev = NULL;
struct rb_node *orig_prev = NULL;
struct extent_map *entry;
struct extent_map *prev_entry = NULL;
- while(n) {
+ while (n) {
entry = rb_entry(n, struct extent_map, rb_node);
prev = n;
prev_entry = entry;
if (prev_ret) {
orig_prev = prev;
- while(prev && offset >= extent_map_end(prev_entry)) {
+ while (prev && offset >= extent_map_end(prev_entry)) {
prev = rb_next(prev);
prev_entry = rb_entry(prev, struct extent_map, rb_node);
}
if (next_ret) {
prev_entry = rb_entry(prev, struct extent_map, rb_node);
- while(prev && offset < prev_entry->start) {
+ while (prev && offset < prev_entry->start) {
prev = rb_prev(prev);
prev_entry = rb_entry(prev, struct extent_map, rb_node);
}
return NULL;
}
+/*
+ * look for an offset in the tree, and if it can't be found, return
+ * the first offset we can find smaller than 'offset'.
+ */
static inline struct rb_node *tree_search(struct rb_root *root, u64 offset)
{
struct rb_node *prev;
return ret;
}
+/* check to see if two extent_map structs are adjacent and safe to merge */
static int mergable_maps(struct extent_map *prev, struct extent_map *next)
{
if (test_bit(EXTENT_FLAG_PINNED, &prev->flags))
return 0;
+ /*
+ * don't merge compressed extents, we need to know their
+ * actual size
+ */
+ if (test_bit(EXTENT_FLAG_COMPRESSED, &prev->flags))
+ return 0;
+
if (extent_map_end(prev) == next->start &&
prev->flags == next->flags &&
prev->bdev == next->bdev &&
if (rb && mergable_maps(merge, em)) {
em->start = merge->start;
em->len += merge->len;
+ em->block_len += merge->block_len;
em->block_start = merge->block_start;
merge->in_tree = 0;
rb_erase(&merge->rb_node, &tree->map);
merge = rb_entry(rb, struct extent_map, rb_node);
if (rb && mergable_maps(em, merge)) {
em->len += merge->len;
+ em->block_len += merge->len;
rb_erase(&merge->rb_node, &tree->map);
merge->in_tree = 0;
free_extent_map(merge);
}
EXPORT_SYMBOL(add_extent_mapping);
+/* simple helper to do math around the end of an extent, handling wrap */
static u64 range_end(u64 start, u64 len)
{
if (start + len < start)