[PATCH] Statlite - without VFS changes

[Simo]

On Fri, 2014-12-19 at 10:36 -0800, Jeremy Allison wrote:
> On Fri, Dec 19, 2014 at 12:43:29PM +0530, Shekhar Amlekar wrote:
> > Hi,
> > 
> > Few days back I submitted a stat-lite patch that proposed a
> > new samba VFS call and hence needed changes to few
> > VFS modules. Here's an attempt to implement the functionality
> > without making changes to Samba VFS. The interface is as
> > follows-
> > 
> > The statlite mask (in stat structure) is always populated by
> > Samba before making a stat call and entering the VFS. For
> > normal stat calls, all the bits are set and for partial stats, only
> > the select bits are set. Samba also updates the mask, after
> > the call.(1)
> > 
> > The opaque VFS modules that support statlite functionality
> > (currently vfs_gpfs) read the mask and retrieve requested
> > attribs. If all the requested attribs can't be retrieved, an error
> > is returned. (2)
> > 
> > Because of (1) and (2), no changes are required to the
> > opaque modules that do not support statlite functionality.
> > They overwriting the mask field would cause no harm
> > (vfs_ceph and vfs_glusterfs zero out the stat structure).
> > 
> > Request your kind review.
> 
> Unfortunately the SMB_STRUCT_STAT is implicitly part of the VFS
> interface, so this still means a VFS change.

Would it be a good time to make it (all or partially) opaque, so we stop
having to bump the VFS interface for internal changes ?
Haven't looked at the patches, so ignore if the changes all need to be
visible by modules and are not just internal.

Simo.

> However these patches look really interesting - I like the
> cleanups you've done around the boilerplate:
> 
>         if (posix_paths) {
>                 ret = SMB_VFS_LSTAT(conn, smb_fname);
>         } else {
>                 ret = SMB_VFS_STAT(conn, smb_fname);
>         }
> 
> code. I'll try and take a closer look soon !
> 
> Thanks a *LOT* for this work.
> 
> Jeremy.


-- 
Simo Sorce