block/genhd.c: apply pm_runtime_set_memalloc_noio on block devices

[karo-tx-linux.git] / block / genhd.c

diff --git a/block/genhd.c b/block/genhd.c
index 3993ebf4135fb1adb8e25c9562dadd996d1c6be2..5f73c2435fde7c14726eb2776289941c8c70761e 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -18,6 +18,7 @@
 #include <linux/mutex.h>
 #include <linux/idr.h>
 #include <linux/log2.h>
+#include <linux/pm_runtime.h>
 
 #include "blk.h"
 
@@ -534,6 +535,14 @@ static void register_disk(struct gendisk *disk)
                        return;
                }
        }
+
+       /*
+        * avoid probable deadlock caused by allocating memory with
+        * GFP_KERNEL in runtime_resume callback of its all ancestor
+        * devices
+        */
+       pm_runtime_set_memalloc_noio(ddev, true);
+
        disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
        disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
 
@@ -663,6 +672,7 @@ void del_gendisk(struct gendisk *disk)
        disk->driverfs_dev = NULL;
        if (!sysfs_deprecated)
                sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
+       pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
        device_del(disk_to_dev(disk));
 }
 EXPORT_SYMBOL(del_gendisk);