mm/zsmalloc.c: migration can leave pages in ZS_EMPTY indefinitely

[sfrench/cifs-2.6.git] / mm / zsmalloc.c

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index db09eb3669c5d9ca630d1cea5ea66d85e2dea70d..5105b9b666537970160001095aa0174820f2a4ed 100644 (file)
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -52,6 +52,7 @@
 #include <linux/zsmalloc.h>
 #include <linux/zpool.h>
 #include <linux/mount.h>
+#include <linux/pseudo_fs.h>
 #include <linux/migrate.h>
 #include <linux/pagemap.h>
 #include <linux/fs.h>
@@ -1798,19 +1799,14 @@ static void lock_zspage(struct zspage *zspage)
        } while ((page = get_next_page(page)) != NULL);
 }
 
-static struct dentry *zs_mount(struct file_system_type *fs_type,
-                               int flags, const char *dev_name, void *data)
+static int zs_init_fs_context(struct fs_context *fc)
 {
-       static const struct dentry_operations ops = {
-               .d_dname = simple_dname,
-       };
-
-       return mount_pseudo(fs_type, "zsmalloc:", NULL, &ops, ZSMALLOC_MAGIC);
+       return init_pseudo(fc, ZSMALLOC_MAGIC) ? 0 : -ENOMEM;
 }
 
 static struct file_system_type zsmalloc_fs = {
        .name           = "zsmalloc",
-       .mount          = zs_mount,
+       .init_fs_context = zs_init_fs_context,
        .kill_sb        = kill_anon_super,
 };
 
@@ -1866,6 +1862,18 @@ static void dec_zspage_isolation(struct zspage *zspage)
        zspage->isolated--;
 }
 
+static void putback_zspage_deferred(struct zs_pool *pool,
+                                   struct size_class *class,
+                                   struct zspage *zspage)
+{
+       enum fullness_group fg;
+
+       fg = putback_zspage(class, zspage);
+       if (fg == ZS_EMPTY)
+               schedule_work(&pool->free_work);
+
+}
+
 static void replace_sub_page(struct size_class *class, struct zspage *zspage,
                                struct page *newpage, struct page *oldpage)
 {
@@ -2035,7 +2043,7 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage,
         * the list if @page is final isolated subpage in the zspage.
         */
        if (!is_zspage_isolated(zspage))
-               putback_zspage(class, zspage);
+               putback_zspage_deferred(pool, class, zspage);
 
        reset_page(page);
        put_page(page);
@@ -2081,14 +2089,13 @@ static void zs_page_putback(struct page *page)
        spin_lock(&class->lock);
        dec_zspage_isolation(zspage);
        if (!is_zspage_isolated(zspage)) {
-               fg = putback_zspage(class, zspage);
                /*
                 * Due to page_lock, we cannot free zspage immediately
                 * so let's defer.
                 */
-               if (fg == ZS_EMPTY)
-                       schedule_work(&pool->free_work);
+               putback_zspage_deferred(pool, class, zspage);
        }
+
        spin_unlock(&class->lock);
 }