Btrfs: add helper for closing one device

Signed-off-by: Anand Jain <anand.jain@oracle.com>
[reworded subject and changelog]
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 694d82b..5688b78 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -764,36 +764,7 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 
        mutex_lock(&fs_devices->device_list_mutex);
        list_for_each_entry_safe(device, tmp, &fs_devices->devices, dev_list) {
-               struct btrfs_device *new_device;
-               struct rcu_string *name;
-
-               if (device->bdev)
-                       fs_devices->open_devices--;
-
-               if (device->writeable &&
-                   device->devid != BTRFS_DEV_REPLACE_DEVID) {
-                       list_del_init(&device->dev_alloc_list);
-                       fs_devices->rw_devices--;
-               }
-
-               if (device->missing)
-                       fs_devices->missing_devices--;
-
-               new_device = btrfs_alloc_device(NULL, &device->devid,
-                                               device->uuid);
-               BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
-
-               /* Safe because we are under uuid_mutex */
-               if (device->name) {
-                       name = rcu_string_strdup(device->name->str, GFP_NOFS);
-                       BUG_ON(!name); /* -ENOMEM */
-                       rcu_assign_pointer(new_device->name, name);
-               }
-
-               list_replace_rcu(&device->dev_list, &new_device->dev_list);
-               new_device->fs_devices = device->fs_devices;
-
-               call_rcu(&device->rcu, free_device);
+               btrfs_close_one_device(device);
        }
        mutex_unlock(&fs_devices->device_list_mutex);
 
@@ -6834,3 +6805,38 @@ void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info)
                fs_devices = fs_devices->seed;
        }
 }
+
+void btrfs_close_one_device(struct btrfs_device *device)
+{
+       struct btrfs_fs_devices *fs_devices = device->fs_devices;
+       struct btrfs_device *new_device;
+       struct rcu_string *name;
+
+       if (device->bdev)
+               fs_devices->open_devices--;
+
+       if (device->writeable &&
+           device->devid != BTRFS_DEV_REPLACE_DEVID) {
+               list_del_init(&device->dev_alloc_list);
+               fs_devices->rw_devices--;
+       }
+
+       if (device->missing)
+               fs_devices->missing_devices--;
+
+       new_device = btrfs_alloc_device(NULL, &device->devid,
+                                       device->uuid);
+       BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
+
+       /* Safe because we are under uuid_mutex */
+       if (device->name) {
+               name = rcu_string_strdup(device->name->str, GFP_NOFS);
+               BUG_ON(!name); /* -ENOMEM */
+               rcu_assign_pointer(new_device->name, name);
+       }
+
+       list_replace_rcu(&device->dev_list, &new_device->dev_list);
+       new_device->fs_devices = device->fs_devices;
+
+       call_rcu(&device->rcu, free_device);
+}

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 8663bf7..38450dc 100644 (file)
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -547,5 +547,6 @@ static inline void unlock_chunks(struct btrfs_root *root)
 struct list_head *btrfs_get_fs_uuids(void);
 void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
 void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
+void btrfs_close_one_device(struct btrfs_device *device);
 
 #endif