Merge tag 'v3.10.87' into update

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1dcef0ceed212f236a09cee1f6d729ed79b98c99..bf4921af2170ccce73fd8404959af657598f04eb 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -773,20 +773,15 @@ 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