On 2018/9/3 下午5:46, Nikolay Borisov wrote:
> Currently this function returns an error code as well as uses one of
> its arguments as a return value for struct btrfs_device. Change the
> function so that it returns btrfs_device directly and use the usual
> "encode error in pointer" mechanics if something goes wrong. No
> functional changes.
>
> Signed-off-by: Nikolay Borisov <nbori...@suse.com>
Reviewed-by: Qu Wenruo <w...@suse.com>
Thanks,
Qu
> ---
> fs/btrfs/volumes.c | 26 ++++++++++++++------------
> 1 file changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index da86706123ff..715ea45c6c28 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -2096,9 +2096,9 @@ void btrfs_destroy_dev_replace_tgtdev(struct
> btrfs_device *tgtdev)
> call_rcu(&tgtdev->rcu, free_device_rcu);
> }
>
> -static int btrfs_find_device_by_path(struct btrfs_fs_info *fs_info,
> - const char *device_path,
> - struct btrfs_device **device)
> +static struct btrfs_device *
> +btrfs_find_device_by_path(struct btrfs_fs_info *fs_info,
> + const char *device_path)
> {
> int ret = 0;
> struct btrfs_super_block *disk_super;
> @@ -2106,21 +2106,21 @@ static int btrfs_find_device_by_path(struct
> btrfs_fs_info *fs_info,
> u8 *dev_uuid;
> struct block_device *bdev;
> struct buffer_head *bh;
> + struct btrfs_device *device;
>
> - *device = NULL;
> ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
> fs_info->bdev_holder, 0, &bdev, &bh);
> if (ret)
> - return ret;
> + return ERR_PTR(ret);
> disk_super = (struct btrfs_super_block *)bh->b_data;
> devid = btrfs_stack_device_id(&disk_super->dev_item);
> dev_uuid = disk_super->dev_item.uuid;
> - *device = btrfs_find_device(fs_info, devid, dev_uuid, disk_super->fsid);
> + device = btrfs_find_device(fs_info, devid, dev_uuid, disk_super->fsid);
> brelse(bh);
> - if (!*device)
> - ret = -ENOENT;
> + if (!device)
> + device = ERR_PTR(-ENOENT);
> blkdev_put(bdev, FMODE_READ);
> - return ret;
> + return device;
> }
>
> int btrfs_find_device_missing_or_by_path(struct btrfs_fs_info *fs_info,
> @@ -2143,11 +2143,13 @@ int btrfs_find_device_missing_or_by_path(struct
> btrfs_fs_info *fs_info,
>
> if (!*device)
> return BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
> -
> - return 0;
> } else {
> - return btrfs_find_device_by_path(fs_info, device_path, device);
> + *device = btrfs_find_device_by_path(fs_info, device_path);
> + if (IS_ERR(*device))
> + return PTR_ERR(*device);
> }
> +
> + return 0;
> }
>
> /*
>
