[PATCH] memory hotadd fixes: enhance collision check

[pandora-kernel.git] / mm / memory_hotplug.c

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 26f1840..c373195 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -52,6 +52,9 @@ static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
        int nr_pages = PAGES_PER_SECTION;
        int ret;
 
+       if (pfn_valid(phys_start_pfn))
+               return -EEXIST;
+
        ret = sparse_add_one_section(zone, phys_start_pfn, nr_pages);
 
        if (ret < 0)
@@ -220,10 +223,9 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
 }
 
 /* add this memory to iomem resource */
-static int register_memory_resource(u64 start, u64 size)
+static struct resource *register_memory_resource(u64 start, u64 size)
 {
        struct resource *res;
-       int ret = 0;
        res = kzalloc(sizeof(struct resource), GFP_KERNEL);
        BUG_ON(!res);
 
@@ -235,9 +237,18 @@ static int register_memory_resource(u64 start, u64 size)
                printk("System RAM resource %llx - %llx cannot be added\n",
                (unsigned long long)res->start, (unsigned long long)res->end);
                kfree(res);
-               ret = -EEXIST;
+               res = NULL;
        }
-       return ret;
+       return res;
+}
+
+static void release_memory_resource(struct resource *res)
+{
+       if (!res)
+               return;
+       release_resource(res);
+       kfree(res);
+       return;
 }
 
 
@@ -246,8 +257,13 @@ int add_memory(int nid, u64 start, u64 size)
 {
        pg_data_t *pgdat = NULL;
        int new_pgdat = 0;
+       struct resource *res;
        int ret;
 
+       res = register_memory_resource(start, size);
+       if (!res)
+               return -EEXIST;
+
        if (!node_online(nid)) {
                pgdat = hotadd_new_pgdat(nid, start);
                if (!pgdat)
@@ -277,14 +293,13 @@ int add_memory(int nid, u64 start, u64 size)
                BUG_ON(ret);
        }
 
-       /* register this memory as resource */
-       ret = register_memory_resource(start, size);
-
        return ret;
 error:
        /* rollback pgdat allocation and others */
        if (new_pgdat)
                rollback_node_hotadd(nid, pgdat);
+       if (res)
+               release_memory_resource(res);
 
        return ret;
 }