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>

2 files changed, 37 insertions, 30 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 694d82bccb0b..5688b7821b3d 100644
--- 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 8663bf7c5051..38450dc28837 100644
--- 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