diff options
Diffstat (limited to 'kernel/mm/filemap.c')
| -rw-r--r-- | kernel/mm/filemap.c | 106 |
1 files changed, 59 insertions, 47 deletions
diff --git a/kernel/mm/filemap.c b/kernel/mm/filemap.c index 44301361c..91dc614cb 100644 --- a/kernel/mm/filemap.c +++ b/kernel/mm/filemap.c @@ -109,6 +109,51 @@ * ->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, + &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; + if (shadowp) + *shadowp = p; + mapping->nrshadows--; + if (node) + workingset_node_shadows_dec(node); + } + 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)) { + local_lock(workingset_shadow_lock); + list_lru_del(&__workingset_shadow_nodes, + &node->private_list); + local_unlock(workingset_shadow_lock); + } + } + return 0; +} + static void page_cache_tree_delete(struct address_space *mapping, struct page *page, void *shadow) { @@ -122,6 +167,14 @@ static void page_cache_tree_delete(struct address_space *mapping, __radix_tree_lookup(&mapping->page_tree, page->index, &node, &slot); + if (!node) { + /* + * We need a node to properly account shadow + * entries. Don't plant any without. XXX + */ + shadow = NULL; + } + if (shadow) { mapping->nrshadows++; /* @@ -540,9 +593,8 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) memcg = mem_cgroup_begin_page_stat(old); spin_lock_irqsave(&mapping->tree_lock, flags); __delete_from_page_cache(old, NULL, memcg); - error = radix_tree_insert(&mapping->page_tree, offset, new); + error = page_cache_tree_insert(mapping, new, NULL); BUG_ON(error); - mapping->nrpages++; /* * hugetlb pages do not participate in page cache accounting. @@ -564,51 +616,6 @@ 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, - &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; - if (shadowp) - *shadowp = p; - mapping->nrshadows--; - if (node) - workingset_node_shadows_dec(node); - } - 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)) { - local_lock(workingset_shadow_lock); - list_lru_del(&__workingset_shadow_nodes, - &node->private_list); - local_unlock(workingset_shadow_lock); - } - } - return 0; -} - static int __add_to_page_cache_locked(struct page *page, struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask, @@ -1557,6 +1564,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos, cond_resched(); find_page: + if (fatal_signal_pending(current)) { + error = -EINTR; + goto out; + } + page = find_get_page(mapping, index); if (!page) { page_cache_sync_readahead(mapping, |