[PATCH] Statlite - without VFS changes

[Jeremy Allison]

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.

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.