# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
#   2005/03/13 16:15:58-08:00 andrea@suse.de 
#   [PATCH] orphaned pagecache memleak fix
#   
#   Chris found that with data journaling a reiserfs pagecache may be truncate
#   while still pinned.  The truncation removes the page->mapping, but the page
#   is still listed in the VM queues because it still has buffers.  Then during
#   the journaling process, a buffer is marked dirty and that sets the PG_dirty
#   bitflag as well (in mark_buffer_dirty).  After that the page is leaked
#   because it's both dirty and without a mapping.
#   
#   So we must allow pages without mapping and dirty to reach the PagePrivate
#   check.  The page->mapping will be checked again right after the PagePrivate
#   check.
#   
#   Signed-off-by: Andrea Arcangeli <andrea@suse.de>
#   Signed-off-by: Andrew Morton <akpm@osdl.org>
#   Signed-off-by: Linus Torvalds <torvalds@osdl.org>
# 
# mm/vmscan.c
#   2005/03/13 15:29:39-08:00 andrea@suse.de +13 -1
#   orphaned pagecache memleak fix
# 
diff -Nru a/mm/vmscan.c b/mm/vmscan.c
--- a/mm/vmscan.c	2005-03-24 16:12:42 +01:00
+++ b/mm/vmscan.c	2005-03-24 16:12:42 +01:00
@@ -313,8 +313,20 @@
 	 */
 	if (!is_page_cache_freeable(page))
 		return PAGE_KEEP;
-	if (!mapping)
+	if (!mapping) {
+		/*
+		 * Some data journaling orphaned pages can have
+		 * page->mapping == NULL while being dirty with clean buffers.
+		 */
+		if (PageDirty(page) && PagePrivate(page)) {
+			if (try_to_free_buffers(page)) {
+				ClearPageDirty(page);
+				printk("%s: orphaned page\n", __FUNCTION__);
+				return PAGE_CLEAN;
+			}
+		}
 		return PAGE_KEEP;
+	}
 	if (mapping->a_ops->writepage == NULL)
 		return PAGE_ACTIVATE;
 	if (!may_write_to_queue(mapping->backing_dev_info))