Merge tag 'v3.14.52' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable into linux-linaro-lsk-v3.14lsk-v3.14-15.09

This is the 3.14.52 stable release

* tag 'v3.14.52' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable: (64 commits)
  Linux 3.14.52
  arm64: KVM: Fix host crash when injecting a fault into a 32bit guest
  SCSI: Fix NULL pointer dereference in runtime PM
  arm64/mm: Remove hack in mmap randomize layout
  crypto: caam - fix memory corruption in ahash_final_ctx
  regmap: regcache-rbtree: Clean new present bits on present bitmap resize
  libfc: Fix fc_fcp_cleanup_each_cmd()
  libfc: Fix fc_exch_recv_req() error path
  drm/vmwgfx: Fix execbuf locking issues
  drm/radeon: add new OLAND pci id
  EDAC, ppc4xx: Access mci->csrows array elements properly
  localmodconfig: Use Kbuild files too
  dm thin metadata: delete btrees when releasing metadata snapshot
  perf: Fix PERF_EVENT_IOC_PERIOD migration race
  perf: Fix fasync handling on inherited events
  xen-blkfront: don't add indirect pages to list when !feature_persistent
  mm/hwpoison: fix page refcount of unknown non LRU page
  ipc/sem.c: update/correct memory barriers
  ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits
  Linux 3.14.51
  ...

1 files changed, 5 insertions, 9 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index b850ced69ed6..88edf53748ee 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -871,21 +871,17 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 		 *
 		 * 2) Global reclaim encounters a page, memcg encounters a
 		 *    page that is not marked for immediate reclaim or
-		 *    the caller does not have __GFP_IO. In this case mark
+		 *    the caller does not have __GFP_FS (or __GFP_IO if it's
+		 *    simply going to swap, not to fs). In this case mark
 		 *    the page for immediate reclaim and continue scanning.
 		 *
-		 *    __GFP_IO is checked  because a loop driver thread might
+		 *    Require may_enter_fs because we would wait on fs, which
+		 *    may not have submitted IO yet. And the loop driver 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.
-		 *
 		 * 3) memcg encounters a page that is not already marked
 		 *    PageReclaim. memcg does not have any dirty pages
 		 *    throttling so we could easily OOM just because too many
@@ -902,7 +898,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 
 			/* Case 2 above */
 			} else 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