shmem: fix faulting into a hole, not taking i_mutex

[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4b5d4f6..7e7f947 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -69,6 +69,7 @@
 
 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
 static DEFINE_MUTEX(pcp_batch_high_lock);
+#define MIN_PERCPU_PAGELIST_FRACTION   (8)
 
 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
 DEFINE_PER_CPU(int, numa_node);
@@ -798,9 +799,21 @@ void __init init_cma_reserved_pageblock(struct page *page)
                set_page_count(p, 0);
        } while (++p, --i);
 
-       set_page_refcounted(page);
        set_pageblock_migratetype(page, MIGRATE_CMA);
-       __free_pages(page, pageblock_order);
+
+       if (pageblock_order >= MAX_ORDER) {
+               i = pageblock_nr_pages;
+               p = page;
+               do {
+                       set_page_refcounted(p);
+                       __free_pages(p, MAX_ORDER - 1);
+                       p += MAX_ORDER_NR_PAGES;
+               } while (i -= MAX_ORDER_NR_PAGES);
+       } else {
+               set_page_refcounted(page);
+               __free_pages(page, pageblock_order);
+       }
+
        adjust_managed_page_count(page, pageblock_nr_pages);
 }
 #endif
@@ -4106,7 +4119,7 @@ static void __meminit zone_init_free_lists(struct zone *zone)
        memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
 #endif
 
-static int __meminit zone_batchsize(struct zone *zone)
+static int zone_batchsize(struct zone *zone)
 {
 #ifdef CONFIG_MMU
        int batch;
@@ -4222,8 +4235,8 @@ static void pageset_set_high(struct per_cpu_pageset *p,
        pageset_update(&p->pcp, high, batch);
 }
 
-static void __meminit pageset_set_high_and_batch(struct zone *zone,
-               struct per_cpu_pageset *pcp)
+static void pageset_set_high_and_batch(struct zone *zone,
+                                      struct per_cpu_pageset *pcp)
 {
        if (percpu_pagelist_fraction)
                pageset_set_high(pcp,
@@ -5848,23 +5861,38 @@ int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
        void __user *buffer, size_t *length, loff_t *ppos)
 {
        struct zone *zone;
-       unsigned int cpu;
+       int old_percpu_pagelist_fraction;
        int ret;
 
+       mutex_lock(&pcp_batch_high_lock);
+       old_percpu_pagelist_fraction = percpu_pagelist_fraction;
+
        ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
-       if (!write || (ret < 0))
-               return ret;
+       if (!write || ret < 0)
+               goto out;
+
+       /* Sanity checking to avoid pcp imbalance */
+       if (percpu_pagelist_fraction &&
+           percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
+               percpu_pagelist_fraction = old_percpu_pagelist_fraction;
+               ret = -EINVAL;
+               goto out;
+       }
+
+       /* No change? */
+       if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
+               goto out;
 
-       mutex_lock(&pcp_batch_high_lock);
        for_each_populated_zone(zone) {
-               unsigned long  high;
-               high = zone->managed_pages / percpu_pagelist_fraction;
+               unsigned int cpu;
+
                for_each_possible_cpu(cpu)
-                       pageset_set_high(per_cpu_ptr(zone->pageset, cpu),
-                                        high);
+                       pageset_set_high_and_batch(zone,
+                                       per_cpu_ptr(zone->pageset, cpu));
        }
+out:
        mutex_unlock(&pcp_batch_high_lock);
-       return 0;
+       return ret;
 }
 
 int hashdist = HASHDIST_DEFAULT;