X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=mm%2Ftruncate.c;h=c6ab55ec6883378cb46367e54c7568f1f2b3983d;hb=e129b5c23c2b471d47f1c5d2b8b193fc2034af43;hp=6cb3fff25f670948d1ef519d7609793b54bfdca3;hpb=9fdb62af92c741addbea15545f214a6e89460865;p=linux-2.6-microblaze.git

diff --git a/mm/truncate.c b/mm/truncate.c
index 6cb3fff25f67..c6ab55ec6883 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -68,10 +68,10 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
 		return 0;
 
 	write_lock_irq(&mapping->tree_lock);
-	if (PageDirty(page)) {
-		write_unlock_irq(&mapping->tree_lock);
-		return 0;
-	}
+	if (PageDirty(page))
+		goto failed;
+	if (page_count(page) != 2)	/* caller's ref + pagecache ref */
+		goto failed;
 
 	BUG_ON(PagePrivate(page));
 	__remove_from_page_cache(page);
@@ -79,6 +79,9 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
 	ClearPageUptodate(page);
 	page_cache_release(page);	/* pagecache ref */
 	return 1;
+failed:
+	write_unlock_irq(&mapping->tree_lock);
+	return 0;
 }
 
 /**
@@ -230,14 +233,24 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
 			pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
 		for (i = 0; i < pagevec_count(&pvec); i++) {
 			struct page *page = pvec.pages[i];
+			pgoff_t index;
+			int lock_failed;
 
-			if (TestSetPageLocked(page)) {
-				next++;
-				continue;
-			}
-			if (page->index > next)
-				next = page->index;
+			lock_failed = TestSetPageLocked(page);
+
+			/*
+			 * We really shouldn't be looking at the ->index of an
+			 * unlocked page.  But we're not allowed to lock these
+			 * pages.  So we rely upon nobody altering the ->index
+			 * of this (pinned-by-us) page.
+			 */
+			index = page->index;
+			if (index > next)
+				next = index;
 			next++;
+			if (lock_failed)
+				continue;
+
 			if (PageDirty(page) || PageWriteback(page))
 				goto unlock;
 			if (page_mapped(page))