X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=mm%2Freadahead.c;fp=mm%2Freadahead.c;h=54d3393219345f0f6c593f535917caba20fcc1d2;hb=16c70f8c1b54b61c3b951b6fb220df250fe09b32;hp=0f142a40984b1674228e067f491159d42b13f32d;hpb=4e76c8a9fa413ccc09d3f7f664183dcce3555d57;p=linux-2.6.git

diff --git a/mm/readahead.c b/mm/readahead.c
index 0f142a409..54d339321 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -14,6 +14,7 @@
 #include <linux/blkdev.h>
 #include <linux/backing-dev.h>
 #include <linux/pagevec.h>
+#include <linux/buffer_head.h>
 
 void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 {
@@ -117,9 +118,28 @@ static inline unsigned long get_next_ra_size(struct file_ra_state *ra)
 
 #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 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_release_page(struct address_space *mapping,
+					  struct page *page)
+{
+	if (PagePrivate(page)) {
+		if (TestSetPageLocked(page))
+			BUG();
+		page->mapping = mapping;
+		try_to_release_page(page, GFP_KERNEL);
+		page->mapping = NULL;
+		unlock_page(page);
+	}
+	page_cache_release(page);
+}
+
 /**
- * read_cache_pages - populate an address space with some pages, and
- * 			start reads against them.
+ * read_cache_pages - populate an address space with some pages & start reads against them
  * @mapping: the address_space
  * @pages: The address of a list_head which contains the target pages.  These
  *   pages have their ->index populated and are otherwise uninitialised.
@@ -141,7 +161,7 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages,
 		page = list_to_page(pages);
 		list_del(&page->lru);
 		if (add_to_page_cache(page, mapping, page->index, GFP_KERNEL)) {
-			page_cache_release(page);
+			read_cache_pages_release_page(mapping, page);
 			continue;
 		}
 		ret = filler(data, page);
@@ -153,7 +173,7 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages,
 
 				victim = list_to_page(pages);
 				list_del(&victim->lru);
-				page_cache_release(victim);
+				read_cache_pages_release_page(mapping, victim);
 			}
 			break;
 		}
@@ -182,14 +202,11 @@ static int read_pages(struct address_space *mapping, struct file *filp,
 		list_del(&page->lru);
 		if (!add_to_page_cache(page, mapping,
 					page->index, GFP_KERNEL)) {
-			ret = mapping->a_ops->readpage(filp, page);
-			if (ret != AOP_TRUNCATED_PAGE) {
-				if (!pagevec_add(&lru_pvec, page))
-					__pagevec_lru_add(&lru_pvec);
-				continue;
-			} /* else fall through to release */
-		}
-		page_cache_release(page);
+			mapping->a_ops->readpage(filp, page);
+			if (!pagevec_add(&lru_pvec, page))
+				__pagevec_lru_add(&lru_pvec);
+		} else
+			page_cache_release(page);
 	}
 	pagevec_lru_add(&lru_pvec);
 	ret = 0;
@@ -394,8 +411,8 @@ int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
  * Read 'nr_to_read' pages starting at page 'offset'. If the flag 'block'
  * is set wait till the read completes.  Otherwise attempt to read without
  * blocking.
- * Returns 1 meaning 'success' if read is succesfull without switching off
- * readhaead mode. Otherwise return failure.
+ * Returns 1 meaning 'success' if read is successful without switching off
+ * readahead mode. Otherwise return failure.
  */
 static int
 blockable_page_cache_readahead(struct address_space *mapping, struct file *filp,