[PATCH 13/14] FS-Cache: Release page->private in failed readahead [try #8]

[David Howells <dhowells@redhat.com>]

The attached patch causes read_cache_pages() to release page-private data on a
page for which add_to_page_cache() fails or the filler function fails. This
permits pages with caching references associated with them to be cleaned up.

Signed-Off-By: David Howells <dhowells@redhat.com>
---

 mm/readahead.c |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/mm/readahead.c b/mm/readahead.c
index 0f142a4..82deb7f 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -141,6 +141,12 @@ int read_cache_pages(struct address_spac
 		page = list_to_page(pages);
 		list_del(&page->lru);
 		if (add_to_page_cache(page, mapping, page->index, GFP_KERNEL)) {
+			if (PagePrivate(page) && mapping->a_ops->releasepage) {
+				page->mapping = mapping;
+				mapping->a_ops->releasepage(page, GFP_KERNEL);
+				page->mapping = NULL;
+			}
+				
 			page_cache_release(page);
 			continue;
 		}
@@ -153,6 +159,16 @@ int read_cache_pages(struct address_spac
 
 				victim = list_to_page(pages);
 				list_del(&victim->lru);
+
+				if (PagePrivate(victim) &&
+				    mapping->a_ops->releasepage
+				    ) {
+					victim->mapping = mapping;
+					mapping->a_ops->releasepage(
+						victim, GFP_KERNEL);
+					victim->mapping = NULL;
+				}
+
 				page_cache_release(victim);
 			}
 			break;