Re: [PATCH] s390: Hypervisor File System

[Andrew Morton <akpm@osdl.org>]

Michael Holzheu <HOLZHEU@de.ibm.com> wrote:
>
> > > +   if (filp->f_mode & FMODE_WRITE) {
>  > > +      if (!(inode->i_mode & S_IWUGO))
>  > > +         return -EACCES;
>  > > +   }
>  > > +   if (filp->f_mode & FMODE_READ) {
>  > > +      if (!(inode->i_mode & S_IRUGO))
>  > > +         return -EACCES;
>  > > +   }
>  >
>  > Is the standard VFS permission checking not appropriate?
>  >
>  > (A comment should be added here).
> 
>  You mean using .permission in the inode operations
>  and using the generic_permission() function?
> 
>  Currently I do not have own inode operations (and
>  I don't want to have them ...)

The VFS-level open() code implements standard permission-checking so I
_think_ you don't need to do anything in here.  See how ramfs does it.

ramfs does have an inode_operations, for ->getattr() support.  So it can
return a correct number in stat->blocks.

sysfs implements inode_operations, so it can do stuff in ->setattr().

I don't think hypfs needs either of those, so you still shouldn't need a
file_inode_operations.