Re: [PATCH] btrfs: remove the cross file system checks from remap

[Nikolay Borisov <nborisov@suse.com>]

On 16.02.22 г. 22:06 ч., Josef Bacik wrote:
> This is handled in the generic VFS helper, we do not need to duplicate
> this inside of btrfs.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
>   fs/btrfs/reflink.c | 4 ----
>   1 file changed, 4 deletions(-)
> 
> diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
> index a3930da4eb3f..4425030e09cb 100644
> --- a/fs/btrfs/reflink.c
> +++ b/fs/btrfs/reflink.c
> @@ -771,10 +771,6 @@ static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
>   
>   		if (btrfs_root_readonly(root_out))
>   			return -EROFS;
> -
> -		if (file_in->f_path.mnt != file_out->f_path.mnt ||
> -		    inode_in->i_sb != inode_out->i_sb)
> -			return -EXDEV;

Where exactly is this check performed in the vfs because I can't see 
anything in generic_remap_file_range_prep.

>   	}
>   
>   	/* Don't make the dst file partly checksummed */