Merge branch 'linux-linaro-lsk-v3.10' into linux-linaro-lsk-v3.10-rtlsk-v3.10-16.03-rtlsk-v3.10-16.02-rtlsk-v3.10-16.01-rtlsk-v3.10-15.12-rtlsk-v3.10-15.11-rtlsk-v3.10-15.10-rtlsk-v3.10-15.09-rtlinux-linaro-lsk-v3.10-rt

1 files changed, 3 insertions, 8 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index a2fd7e759cb7..233f0011f768 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -730,20 +730,15 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			 * could easily OOM just because too many pages are in
 			 * writeback and there is nothing else to reclaim.
 			 *
-			 * Check __GFP_IO, certainly because a loop driver
+			 * Require may_enter_fs to wait on writeback, because
+			 * fs may not have submitted IO yet. And a loop driver
 			 * thread might enter reclaim, and deadlock if it waits
 			 * on a page for which it is needed to do the write
 			 * (loop masks off __GFP_IO|__GFP_FS for this reason);
 			 * but more thought would probably show more reasons.
-			 *
-			 * Don't require __GFP_FS, since we're not going into
-			 * the FS, just waiting on its writeback completion.
-			 * Worryingly, ext4 gfs2 and xfs allocate pages with
-			 * grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so
-			 * testing may_enter_fs here is liable to OOM on them.
 			 */
 			if (global_reclaim(sc) ||
-			    !PageReclaim(page) || !(sc->gfp_mask & __GFP_IO)) {
+			    !PageReclaim(page) || !may_enter_fs) {
 				/*
 				 * This is slightly racy - end_page_writeback()
 				 * might have just cleared PageReclaim, then