Add buffer head related helper functions

[linux-2.6-omap-h63xx.git] / mm / backing-dev.c

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 841901a955955a8be07b88a5e75658743c0af5ef..e8644b1e5527df1069f968d17d1893fa0dc3e5fa 100644 (file)
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -5,6 +5,41 @@
 #include <linux/sched.h>
 #include <linux/module.h>
 
+int bdi_init(struct backing_dev_info *bdi)
+{
+       int i;
+       int err;
+
+       for (i = 0; i < NR_BDI_STAT_ITEMS; i++) {
+               err = percpu_counter_init_irq(&bdi->bdi_stat[i], 0);
+               if (err)
+                       goto err;
+       }
+
+       bdi->dirty_exceeded = 0;
+       err = prop_local_init_percpu(&bdi->completions);
+
+       if (err) {
+err:
+               while (i--)
+                       percpu_counter_destroy(&bdi->bdi_stat[i]);
+       }
+
+       return err;
+}
+EXPORT_SYMBOL(bdi_init);
+
+void bdi_destroy(struct backing_dev_info *bdi)
+{
+       int i;
+
+       for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
+               percpu_counter_destroy(&bdi->bdi_stat[i]);
+
+       prop_local_destroy_percpu(&bdi->completions);
+}
+EXPORT_SYMBOL(bdi_destroy);
+
 static wait_queue_head_t congestion_wqh[2] = {
                __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
                __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])
@@ -54,3 +89,4 @@ long congestion_wait(int rw, long timeout)
        return ret;
 }
 EXPORT_SYMBOL(congestion_wait);
+