Re: [PATCH v5 5/7] fs: make vfs_fileattr_[get|set] return -EOPNOSUPP

[Andrey Albershteyn <aalbersh@redhat.com>]

On 2025-05-12 15:22:52, Andrey Albershteyn wrote:
> Future patches will add new syscalls which use these functions. As
> this interface won't be used for ioctls only the EOPNOSUPP is more
> appropriate return code.
> 
> This patch coverts return code from ENOIOCTLCMD to EOPNOSUPP for
> vfs_fileattr_get and vfs_fileattr_set. To save old behavior
> translate EOPNOSUPP back for current users - overlayfs, encryptfs
> and fs/ioctl.c.
> 
> Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
> ---
>  fs/ecryptfs/inode.c  |  8 +++++++-
>  fs/file_attr.c       | 12 ++++++++++--
>  fs/overlayfs/inode.c |  2 +-
>  3 files changed, 18 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
> index 51a5c54eb740..6bf08ff4d7f7 100644
> --- a/fs/ecryptfs/inode.c
> +++ b/fs/ecryptfs/inode.c
> @@ -1124,7 +1124,13 @@ static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
>  
>  static int ecryptfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
>  {
> -	return vfs_fileattr_get(ecryptfs_dentry_to_lower(dentry), fa);
> +	int rc;
> +
> +	rc = vfs_fileattr_get(ecryptfs_dentry_to_lower(dentry), fa);
> +	if (rc == -EOPNOTSUPP)
> +		rc = -ENOIOCTLCMD;
> +
> +	return rc;
>  }
>  
>  static int ecryptfs_fileattr_set(struct mnt_idmap *idmap,
> diff --git a/fs/file_attr.c b/fs/file_attr.c
> index d9eab553dc25..d696f440fa4f 100644
> --- a/fs/file_attr.c
> +++ b/fs/file_attr.c
> @@ -79,7 +79,7 @@ int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
>  	int error;
>  
>  	if (!inode->i_op->fileattr_get)
> -		return -ENOIOCTLCMD;
> +		return -EOPNOTSUPP;
>  
>  	error = security_inode_file_getattr(dentry, fa);
>  	if (error)
> @@ -239,7 +239,7 @@ int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
>  	int err;
>  
>  	if (!inode->i_op->fileattr_set)
> -		return -ENOIOCTLCMD;
> +		return -EOPNOTSUPP;
>  
>  	if (!inode_owner_or_capable(idmap, inode))
>  		return -EPERM;
> @@ -281,6 +281,8 @@ int ioctl_getflags(struct file *file, unsigned int __user *argp)
>  	int err;
>  
>  	err = vfs_fileattr_get(file->f_path.dentry, &fa);
> +	if (err == -EOPNOTSUPP)
> +		err = -ENOIOCTLCMD;
>  	if (!err)
>  		err = put_user(fa.flags, argp);
>  	return err;
> @@ -302,6 +304,8 @@ int ioctl_setflags(struct file *file, unsigned int __user *argp)
>  			fileattr_fill_flags(&fa, flags);
>  			err = vfs_fileattr_set(idmap, dentry, &fa);
>  			mnt_drop_write_file(file);
> +			if (err == -EOPNOTSUPP)
> +				err = -ENOIOCTLCMD;
>  		}
>  	}
>  	return err;
> @@ -314,6 +318,8 @@ int ioctl_fsgetxattr(struct file *file, void __user *argp)
>  	int err;
>  
>  	err = vfs_fileattr_get(file->f_path.dentry, &fa);
> +	if (err == -EOPNOTSUPP)
> +		err = -ENOIOCTLCMD;
>  	if (!err)
>  		err = copy_fsxattr_to_user(&fa, argp);
>  
> @@ -334,6 +340,8 @@ int ioctl_fssetxattr(struct file *file, void __user *argp)
>  		if (!err) {
>  			err = vfs_fileattr_set(idmap, dentry, &fa);
>  			mnt_drop_write_file(file);
> +			if (err == -EOPNOTSUPP)
> +				err = -ENOIOCTLCMD;
>  		}
>  	}
>  	return err;
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index 6f0e15f86c21..096d44712bb1 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -721,7 +721,7 @@ int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa)
>  		return err;
>  
>  	err = vfs_fileattr_get(realpath->dentry, fa);
> -	if (err == -ENOIOCTLCMD)
> +	if (err == -EOPNOTSUPP)
>  		err = -ENOTTY;
>  	return err;
>  }
> 
> -- 
> 2.47.2
> 
> 
> -- 
> - Andrey

Ignore please, sorry, wrong in-reply-to

-- 
- Andrey