From d3604d3795872e788fb3fe32bcd072bff53c169c Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Fri, 23 Jun 2006 02:05:48 -0700
Subject: [PATCH] --- yaml --- r: 29068 b: refs/heads/master c:
 e0f23603fb2607315ce52432cc4225df410828cf h: refs/heads/master v: v3

---
 [refs]              |  2 +-
 trunk/mm/truncate.c | 22 ++++++++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/[refs] b/[refs]
index 353f0026f7e3..4595db64fe0c 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 57ae2508610d50893cb3e3bbb869ff70ff724a2a
+refs/heads/master: e0f23603fb2607315ce52432cc4225df410828cf
diff --git a/trunk/mm/truncate.c b/trunk/mm/truncate.c
index 6cb3fff25f67..cf1b015df4a7 100644
--- a/trunk/mm/truncate.c
+++ b/trunk/mm/truncate.c
@@ -230,14 +230,24 @@ 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))