Merge commit 'v2.6.35-rc3' into perf/core

Merge reason: Go from -rc1 base to -rc3 base, merge in fixes.

3 files changed, 41 insertions, 27 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index b289310e2c89..bbd396ac9546 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -597,7 +597,7 @@ static void balance_dirty_pages(struct address_space *mapping,
 	    (!laptop_mode && ((global_page_state(NR_FILE_DIRTY)
 			       + global_page_state(NR_UNSTABLE_NFS))
 					  > background_thresh)))
-		bdi_start_writeback(bdi, NULL, 0, 0);
+		bdi_start_writeback(bdi, NULL, 0);
 }
 
 void set_page_dirty_balance(struct page *page, int page_mkwrite)
@@ -707,7 +707,7 @@ void laptop_mode_timer_fn(unsigned long data)
 	 */
 
 	if (bdi_has_dirty_io(&q->backing_dev_info))
-		bdi_start_writeback(&q->backing_dev_info, NULL, nr_pages, 0);
+		bdi_start_writeback(&q->backing_dev_info, NULL, nr_pages);
 }
 
 /*
@@ -835,7 +835,6 @@ int write_cache_pages(struct address_space *mapping,
 	pgoff_t done_index;
 	int cycled;
 	int range_whole = 0;
-	long nr_to_write = wbc->nr_to_write;
 
 	pagevec_init(&pvec, 0);
 	if (wbc->range_cyclic) {
@@ -852,7 +851,22 @@ int write_cache_pages(struct address_space *mapping,
 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 			range_whole = 1;
 		cycled = 1; /* ignore range_cyclic tests */
+
+		/*
+		 * If this is a data integrity sync, cap the writeback to the
+		 * current end of file. Any extension to the file that occurs
+		 * after this is a new write and we don't need to write those
+		 * pages out to fulfil our data integrity requirements. If we
+		 * try to write them out, we can get stuck in this scan until
+		 * the concurrent writer stops adding dirty pages and extending
+		 * EOF.
+		 */
+		if (wbc->sync_mode == WB_SYNC_ALL &&
+		    wbc->range_end == LLONG_MAX) {
+			end = i_size_read(mapping->host) >> PAGE_CACHE_SHIFT;
+		}
 	}
+
 retry:
 	done_index = index;
 	while (!done && (index <= end)) {
@@ -935,11 +949,10 @@ continue_unlock:
 					done = 1;
 					break;
 				}
- 			}
+			}
 
-			if (nr_to_write > 0) {
-				nr_to_write--;
-				if (nr_to_write == 0 &&
+			if (wbc->nr_to_write > 0) {
+				if (--wbc->nr_to_write == 0 &&
 				    wbc->sync_mode == WB_SYNC_NONE) {
 					/*
 					 * We stop writing back only if we are
@@ -970,11 +983,8 @@ continue_unlock:
 		end = writeback_index - 1;
 		goto retry;
 	}
-	if (!wbc->no_nrwrite_index_update) {
-		if (wbc->range_cyclic || (range_whole && nr_to_write > 0))
-			mapping->writeback_index = done_index;
-		wbc->nr_to_write = nr_to_write;
-	}
+	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
+		mapping->writeback_index = done_index;
 
 	return ret;
 }
diff --git a/mm/shmem.c b/mm/shmem.c
index 7e5030ae18ff..f65f84062db5 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -764,10 +764,11 @@ done2:
 static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = dentry->d_inode;
+	loff_t newsize = attr->ia_size;
 	int error;
 
-	if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
-		loff_t newsize = attr->ia_size;
+	if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)
+					&& newsize != inode->i_size) {
 		struct page *page = NULL;
 
 		if (newsize < inode->i_size) {
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 915dceb487c1..9c7e57cc63a3 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1724,13 +1724,13 @@ static void shrink_zone(int priority, struct zone *zone,
  * If a zone is deemed to be full of pinned pages then just give it a light
  * scan then give up on it.
  */
-static int shrink_zones(int priority, struct zonelist *zonelist,
+static bool shrink_zones(int priority, struct zonelist *zonelist,
 					struct scan_control *sc)
 {
 	enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask);
 	struct zoneref *z;
 	struct zone *zone;
-	int progress = 0;
+	bool all_unreclaimable = true;
 
 	for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx,
 					sc->nodemask) {
@@ -1757,9 +1757,9 @@ static int shrink_zones(int priority, struct zonelist *zonelist,
 		}
 
 		shrink_zone(priority, zone, sc);
-		progress = 1;
+		all_unreclaimable = false;
 	}
-	return progress;
+	return all_unreclaimable;
 }
 
 /*
@@ -1782,7 +1782,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 					struct scan_control *sc)
 {
 	int priority;
-	unsigned long ret = 0;
+	bool all_unreclaimable;
 	unsigned long total_scanned = 0;
 	struct reclaim_state *reclaim_state = current->reclaim_state;
 	unsigned long lru_pages = 0;
@@ -1813,7 +1813,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 		sc->nr_scanned = 0;
 		if (!priority)
 			disable_swap_token();
-		ret = shrink_zones(priority, zonelist, sc);
+		all_unreclaimable = shrink_zones(priority, zonelist, sc);
 		/*
 		 * Don't shrink slabs when reclaiming memory from
 		 * over limit cgroups
@@ -1826,10 +1826,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 			}
 		}
 		total_scanned += sc->nr_scanned;
-		if (sc->nr_reclaimed >= sc->nr_to_reclaim) {
-			ret = sc->nr_reclaimed;
+		if (sc->nr_reclaimed >= sc->nr_to_reclaim)
 			goto out;
-		}
 
 		/*
 		 * Try to write back as many pages as we just scanned.  This
@@ -1849,9 +1847,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 		    priority < DEF_PRIORITY - 2)
 			congestion_wait(BLK_RW_ASYNC, HZ/10);
 	}
-	/* top priority shrink_zones still had more to do? don't OOM, then */
-	if (ret && scanning_global_lru(sc))
-		ret = sc->nr_reclaimed;
+
 out:
 	/*
 	 * Now that we've scanned all the zones at this priority level, note
@@ -1877,7 +1873,14 @@ out:
 	delayacct_freepages_end();
 	put_mems_allowed();
 
-	return ret;
+	if (sc->nr_reclaimed)
+		return sc->nr_reclaimed;
+
+	/* top priority shrink_zones still had more to do? don't OOM, then */
+	if (scanning_global_lru(sc) && !all_unreclaimable)
+		return 1;
+
+	return 0;
 }
 
 unsigned long try_to_free_pages(struct zonelist *zonelist, int order,