ext4: make fsync to sync parent dir in no-journal for real this time

[firefly-linux-kernel-4.4.55.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 378a15bcd64940cd4bab29335604f757543839be..494a081ec5e4c56dad62f3ca8d4646fd96043191 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -360,9 +360,11 @@ void prep_compound_page(struct page *page, unsigned long order)
        __SetPageHead(page);
        for (i = 1; i < nr_pages; i++) {
                struct page *p = page + i;
-               __SetPageTail(p);
                set_page_count(p, 0);
                p->first_page = page;
+               /* Make sure p->first_page is always valid for PageTail() */
+               smp_wmb();
+               __SetPageTail(p);
        }
 }
 
@@ -1628,6 +1630,7 @@ static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
        long min = mark;
        long lowmem_reserve = z->lowmem_reserve[classzone_idx];
        int o;
+       long free_cma = 0;
 
        free_pages -= (1 << order) - 1;
        if (alloc_flags & ALLOC_HIGH)
@@ -1637,9 +1640,10 @@ static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 #ifdef CONFIG_CMA
        /* If allocation can't use CMA areas don't use free CMA pages */
        if (!(alloc_flags & ALLOC_CMA))
-               free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
+               free_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
 #endif
-       if (free_pages <= min + lowmem_reserve)
+
+       if (free_pages - free_cma <= min + lowmem_reserve)
                return false;
        for (o = 0; o < order; o++) {
                /* At the next order, this order's pages become unavailable */
@@ -2115,6 +2119,14 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
                return NULL;
        }
 
+       /*
+        * PM-freezer should be notified that there might be an OOM killer on
+        * its way to kill and wake somebody up. This is too early and we might
+        * end up not killing anything but false positives are acceptable.
+        * See freeze_processes.
+        */
+       note_oom_kill();
+
        /*
         * Go through the zonelist yet one more time, keep very high watermark
         * here, this is only to catch a parallel oom killing, we must fail if
@@ -2335,7 +2347,7 @@ static inline int
 gfp_to_alloc_flags(gfp_t gfp_mask)
 {
        int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
-       const gfp_t wait = gfp_mask & __GFP_WAIT;
+       const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));
 
        /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
        BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
@@ -2344,20 +2356,20 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
         * The caller may dip into page reserves a bit more if the caller
         * cannot run direct reclaim, or if the caller has realtime scheduling
         * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
-        * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
+        * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
         */
        alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
 
-       if (!wait) {
+       if (atomic) {
                /*
-                * Not worth trying to allocate harder for
-                * __GFP_NOMEMALLOC even if it can't schedule.
+                * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
+                * if it can't schedule.
                 */
-               if  (!(gfp_mask & __GFP_NOMEMALLOC))
+               if (!(gfp_mask & __GFP_NOMEMALLOC))
                        alloc_flags |= ALLOC_HARDER;
                /*
-                * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
-                * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
+                * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
+                * comment for __cpuset_node_allowed_softwall().
                 */
                alloc_flags &= ~ALLOC_CPUSET;
        } else if (unlikely(rt_task(current)) && !in_interrupt())
@@ -6140,6 +6152,10 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
                list_del(&page->lru);
                rmv_page_order(page);
                zone->free_area[order].nr_free--;
+#ifdef CONFIG_HIGHMEM
+               if (PageHighMem(page))
+                       totalhigh_pages -= 1 << order;
+#endif
                for (i = 0; i < (1 << order); i++)
                        SetPageReserved((page+i));
                pfn += (1 << order);