tracing: Append prompt in /debug/tracing/README file

[pandora-kernel.git] / mm / readahead.c

diff --git a/mm/readahead.c b/mm/readahead.c
index 9ce303d..133b6d5 100644 (file)
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -31,6 +31,42 @@ EXPORT_SYMBOL_GPL(file_ra_state_init);
 
 #define list_to_page(head) (list_entry((head)->prev, struct page, lru))
 
+/*
+ * see if a page needs releasing upon read_cache_pages() failure
+ * - the caller of read_cache_pages() may have set PG_private or PG_fscache
+ *   before calling, such as the NFS fs marking pages that are cached locally
+ *   on disk, thus we need to give the fs a chance to clean up in the event of
+ *   an error
+ */
+static void read_cache_pages_invalidate_page(struct address_space *mapping,
+                                            struct page *page)
+{
+       if (page_has_private(page)) {
+               if (!trylock_page(page))
+                       BUG();
+               page->mapping = mapping;
+               do_invalidatepage(page, 0);
+               page->mapping = NULL;
+               unlock_page(page);
+       }
+       page_cache_release(page);
+}
+
+/*
+ * release a list of pages, invalidating them first if need be
+ */
+static void read_cache_pages_invalidate_pages(struct address_space *mapping,
+                                             struct list_head *pages)
+{
+       struct page *victim;
+
+       while (!list_empty(pages)) {
+               victim = list_to_page(pages);
+               list_del(&victim->lru);
+               read_cache_pages_invalidate_page(mapping, victim);
+       }
+}
+
 /**
  * read_cache_pages - populate an address space with some pages & start reads against them
  * @mapping: the address_space
@@ -52,14 +88,14 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages,
                list_del(&page->lru);
                if (add_to_page_cache_lru(page, mapping,
                                        page->index, GFP_KERNEL)) {
-                       page_cache_release(page);
+                       read_cache_pages_invalidate_page(mapping, page);
                        continue;
                }
                page_cache_release(page);
 
                ret = filler(data, page);
                if (unlikely(ret)) {
-                       put_pages_list(pages);
+                       read_cache_pages_invalidate_pages(mapping, pages);
                        break;
                }
                task_io_account_read(PAGE_CACHE_SIZE);