Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
 "A few misc subsystems and some of MM.

  175 patches.

  Subsystems affected by this patch series: ia64, kbuild, scripts, sh,
  ocfs2, kfifo, vfs, kernel/watchdog, and mm (slab-generic, slub,
  kmemleak, debug, pagecache, msync, gup, memremap, memcg, pagemap,
  mremap, dma, sparsemem, vmalloc, documentation, kasan, initialization,
  pagealloc, and memory-failure)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (175 commits)
  mm/memory-failure: unnecessary amount of unmapping
  mm/mmzone.h: fix existing kernel-doc comments and link them to core-api
  mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1
  net: page_pool: use alloc_pages_bulk in refill code path
  net: page_pool: refactor dma_map into own function page_pool_dma_map
  SUNRPC: refresh rq_pages using a bulk page allocator
  SUNRPC: set rq_page_end differently
  mm/page_alloc: inline __rmqueue_pcplist
  mm/page_alloc: optimize code layout for __alloc_pages_bulk
  mm/page_alloc: add an array-based interface to the bulk page allocator
  mm/page_alloc: add a bulk page allocator
  mm/page_alloc: rename alloced to allocated
  mm/page_alloc: duplicate include linux/vmalloc.h
  mm, page_alloc: avoid page_to_pfn() in move_freepages()
  mm/Kconfig: remove default DISCONTIGMEM_MANUAL
  mm: page_alloc: dump migrate-failed pages
  mm/mempolicy: fix mpol_misplaced kernel-doc
  mm/mempolicy: rewrite alloc_pages_vma documentation
  mm/mempolicy: rewrite alloc_pages documentation
  mm/mempolicy: rename alloc_pages_current to alloc_pages
  ...

1 files changed, 5 insertions, 1 deletions

diff --git a/mm/msync.c b/mm/msync.c
index 69c6d2029531..137d1c104f3e 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -55,7 +55,9 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
 		goto out;
 	/*
 	 * If the interval [start,end) covers some unmapped address ranges,
-	 * just ignore them, but return -ENOMEM at the end.
+	 * just ignore them, but return -ENOMEM at the end. Besides, if the
+	 * flag is MS_ASYNC (w/o MS_INVALIDATE) the result would be -ENOMEM
+	 * anyway and there is nothing left to do, so return immediately.
 	 */
 	mmap_read_lock(mm);
 	vma = find_vma(mm, start);
@@ -69,6 +71,8 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
 			goto out_unlock;
 		/* Here start < vma->vm_end. */
 		if (start < vma->vm_start) {
+			if (flags == MS_ASYNC)
+				goto out_unlock;
 			start = vma->vm_start;
 			if (start >= end)
 				goto out_unlock;