btrfs: fix null pointer deref when target device is missing

[sfrench/cifs-2.6.git] / fs / btrfs / dev-replace.c

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 7efbc4d1128b222f0d18c18998b0f955debc2ac9..c523478b3de2298e45c5b58e8671b9b58b499fac 100644 (file)
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -44,7 +44,6 @@ static void btrfs_dev_replace_update_device_in_mapping_tree(
                                                struct btrfs_fs_info *fs_info,
                                                struct btrfs_device *srcdev,
                                                struct btrfs_device *tgtdev);
-static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
 static int btrfs_dev_replace_kthread(void *data);
 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
 
@@ -174,8 +173,14 @@ no_valid_dev_replace_entry_found:
                        }
                        set_bit(BTRFS_DEV_STATE_REPLACE_TGT,
                                &dev_replace->tgtdev->dev_state);
-                       btrfs_init_dev_replace_tgtdev_for_resume(fs_info,
-                               dev_replace->tgtdev);
+
+                       WARN_ON(fs_info->fs_devices->rw_devices == 0);
+                       dev_replace->tgtdev->io_width = fs_info->sectorsize;
+                       dev_replace->tgtdev->io_align = fs_info->sectorsize;
+                       dev_replace->tgtdev->sector_size = fs_info->sectorsize;
+                       dev_replace->tgtdev->fs_info = fs_info;
+                       set_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
+                               &dev_replace->tgtdev->dev_state);
                }
                break;
        }
@@ -307,7 +312,7 @@ void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info)
 
 static char* btrfs_dev_name(struct btrfs_device *device)
 {
-       if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
+       if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
                return "<missing disk>";
        else
                return rcu_str_deref(device->name);
@@ -694,20 +699,13 @@ void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
        btrfs_dev_replace_unlock(dev_replace, 0);
 }
 
-int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
-                            struct btrfs_ioctl_dev_replace_args *args)
-{
-       args->result = __btrfs_dev_replace_cancel(fs_info);
-       return 0;
-}
-
-static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
+int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
 {
        struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
        struct btrfs_device *tgt_device = NULL;
        struct btrfs_trans_handle *trans;
        struct btrfs_root *root = fs_info->tree_root;
-       u64 result;
+       int result;
        int ret;
 
        if (sb_rdonly(fs_info->sb))