diff --git a/include/linux/swap.h b/include/linux/swap.h index b17cc4830fa6..4a529c984a3f 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -257,6 +257,7 @@ static inline void workingset_node_pages_inc(struct radix_tree_node *node) static inline void workingset_node_pages_dec(struct radix_tree_node *node) { + VM_BUG_ON(!workingset_node_pages(node)); node->count--; } @@ -272,6 +273,7 @@ static inline void workingset_node_shadows_inc(struct radix_tree_node *node) static inline void workingset_node_shadows_dec(struct radix_tree_node *node) { + VM_BUG_ON(!workingset_node_shadows(node)); node->count -= 1U << RADIX_TREE_COUNT_SHIFT; } diff --git a/mm/filemap.c b/mm/filemap.c index 8a287dfc5372..2d0986a64f1f 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -110,6 +110,62 @@ * ->tasklist_lock (memory_failure, collect_procs_ao) */ +static int page_cache_tree_insert(struct address_space *mapping, + struct page *page, void **shadowp) +{ + struct radix_tree_node *node; + void **slot; + int error; + + error = __radix_tree_create(&mapping->page_tree, page->index, 0, + &node, &slot); + if (error) + return error; + if (*slot) { + void *p; + + p = radix_tree_deref_slot_protected(slot, &mapping->tree_lock); + if (!radix_tree_exceptional_entry(p)) + return -EEXIST; + + mapping->nrexceptional--; + if (!dax_mapping(mapping)) { + if (shadowp) + *shadowp = p; + if (node) + workingset_node_shadows_dec(node); + } else { + /* DAX can replace empty locked entry with a hole */ + WARN_ON_ONCE(p != + (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | + RADIX_DAX_ENTRY_LOCK)); + /* DAX accounts exceptional entries as normal pages */ + if (node) + workingset_node_pages_dec(node); + /* Wakeup waiters for exceptional entry lock */ + dax_wake_mapping_entry_waiter(mapping, page->index, + false); + } + } + radix_tree_replace_slot(slot, page); + mapping->nrpages++; + if (node) { + workingset_node_pages_inc(node); + /* + * Don't track node that contains actual pages. + * + * Avoid acquiring the list_lru lock if already + * untracked. The list_empty() test is safe as + * node->private_list is protected by + * mapping->tree_lock. + */ + if (!list_empty(&node->private_list)) + list_lru_del(&workingset_shadow_nodes, + &node->private_list); + } + return 0; +} + static void page_cache_tree_delete(struct address_space *mapping, struct page *page, void *shadow) { @@ -561,7 +617,7 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) spin_lock_irqsave(&mapping->tree_lock, flags); __delete_from_page_cache(old, NULL); - error = radix_tree_insert(&mapping->page_tree, offset, new); + error = page_cache_tree_insert(mapping, new, NULL); BUG_ON(error); mapping->nrpages++; @@ -584,62 +640,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) } EXPORT_SYMBOL_GPL(replace_page_cache_page); -static int page_cache_tree_insert(struct address_space *mapping, - struct page *page, void **shadowp) -{ - struct radix_tree_node *node; - void **slot; - int error; - - error = __radix_tree_create(&mapping->page_tree, page->index, 0, - &node, &slot); - if (error) - return error; - if (*slot) { - void *p; - - p = radix_tree_deref_slot_protected(slot, &mapping->tree_lock); - if (!radix_tree_exceptional_entry(p)) - return -EEXIST; - - mapping->nrexceptional--; - if (!dax_mapping(mapping)) { - if (shadowp) - *shadowp = p; - if (node) - workingset_node_shadows_dec(node); - } else { - /* DAX can replace empty locked entry with a hole */ - WARN_ON_ONCE(p != - (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | - RADIX_DAX_ENTRY_LOCK)); - /* DAX accounts exceptional entries as normal pages */ - if (node) - workingset_node_pages_dec(node); - /* Wakeup waiters for exceptional entry lock */ - dax_wake_mapping_entry_waiter(mapping, page->index, - false); - } - } - radix_tree_replace_slot(slot, page); - mapping->nrpages++; - if (node) { - workingset_node_pages_inc(node); - /* - * Don't track node that contains actual pages. - * - * Avoid acquiring the list_lru lock if already - * untracked. The list_empty() test is safe as - * node->private_list is protected by - * mapping->tree_lock. - */ - if (!list_empty(&node->private_list)) - list_lru_del(&workingset_shadow_nodes, - &node->private_list); - } - return 0; -} - static int __add_to_page_cache_locked(struct page *page, struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask, diff --git a/mm/workingset.c b/mm/workingset.c index 69551cfae97b..617475f529f4 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -418,21 +418,19 @@ static enum lru_status shadow_lru_isolate(struct list_head *item, * no pages, so we expect to be able to remove them all and * delete and free the empty node afterwards. */ - - BUG_ON(!node->count); - BUG_ON(node->count & RADIX_TREE_COUNT_MASK); + BUG_ON(!workingset_node_shadows(node)); + BUG_ON(workingset_node_pages(node)); for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) { if (node->slots[i]) { BUG_ON(!radix_tree_exceptional_entry(node->slots[i])); node->slots[i] = NULL; - BUG_ON(node->count < (1U << RADIX_TREE_COUNT_SHIFT)); - node->count -= 1U << RADIX_TREE_COUNT_SHIFT; + workingset_node_shadows_dec(node); BUG_ON(!mapping->nrexceptional); mapping->nrexceptional--; } } - BUG_ON(node->count); + BUG_ON(workingset_node_shadows(node)); inc_node_state(page_pgdat(virt_to_page(node)), WORKINGSET_NODERECLAIM); if (!__radix_tree_delete_node(&mapping->page_tree, node)) BUG();