return 0;
}
-static void zswap_rb_erase(struct rb_root *root, struct zswap_entry *entry)
+static bool zswap_rb_erase(struct rb_root *root, struct zswap_entry *entry)
{
if (!RB_EMPTY_NODE(&entry->rbnode)) {
rb_erase(&entry->rbnode, root);
RB_CLEAR_NODE(&entry->rbnode);
+ return true;
}
+ return false;
}
/*
return NULL;
}
+/*
+ * If the entry is still valid in the tree, drop the initial ref and remove it
+ * from the tree. This function must be called with an additional ref held,
+ * otherwise it may race with another invalidation freeing the entry.
+ */
static void zswap_invalidate_entry(struct zswap_tree *tree,
struct zswap_entry *entry)
{
- /* remove from rbtree */
- zswap_rb_erase(&tree->rbroot, entry);
-
- /* drop the initial reference from entry creation */
- zswap_entry_put(tree, entry);
+ if (zswap_rb_erase(&tree->rbroot, entry))
+ zswap_entry_put(tree, entry);
}
static int zswap_reclaim_entry(struct zswap_pool *pool)
* swapcache. Drop the entry from zswap - unless invalidate already
* took it out while we had the tree->lock released for IO.
*/
- if (entry == zswap_rb_search(&tree->rbroot, swpoffset))
- zswap_invalidate_entry(tree, entry);
+ zswap_invalidate_entry(tree, entry);
put_unlock:
/* Drop local reference */
count_objcg_event(entry->objcg, ZSWPIN);
freeentry:
spin_lock(&tree->lock);
- zswap_entry_put(tree, entry);
if (!ret && zswap_exclusive_loads_enabled) {
zswap_invalidate_entry(tree, entry);
*exclusive = true;
list_move(&entry->lru, &entry->pool->lru);
spin_unlock(&entry->pool->lru_lock);
}
+ zswap_entry_put(tree, entry);
spin_unlock(&tree->lock);
return ret;