Samba project aspirant for GSOC 2014

[Jeff Layton]

On Tue, 4 Mar 2014 12:24:03 +0100
David Disseldorp <ddiss at suse.de> wrote:

> Thanks for your interest Saket!
> 
> On Tue, 25 Feb 2014 13:51:33 +0530, Saket Sinha wrote:
> 
> > This year I am again interested in applying for GSOC for some linux
> > kernel filesystem related work. I wnet through the Samba GSOC ideas
> > and the following two projects interested me-
> > 

Hmm that page is somewhat out of date now...

> > http://wiki.samba.org/index.php/SoC/Ideas#VFS_change_notification_support
> > 

The above will be tough. You'd have to plumb in inotify operation
support into the VFS layer so that filesystems get called when inotify
watches are set or destroyed. That'll take some careful design work
(and salesmanship to the generic VFS maintainers).

> > http://wiki.samba.org/index.php/SoC/Ideas#Create_a_common_uid_mapping_mechanism_for_Linux_nfs_and_cifs_vfs_clients
> > 

I'm not sure this one is really valid anymore, but Steve might have
other ideas. We have an idmapping mechanism for cifs now though it's
necessarily different from the one NFS uses.

NFSv4 goes something like:

    NFSv4 username at DOMAIN <-> UID

...whereas cifs is:

    Windows SID <-> UID

...given the protocol differences, I'm not sure how much you can really
merge the two (or what the point of doing so would be).

> > Kindly let me know which of these is most viable and how to get
> > started with these projects for this GSOC programme.
> 
> Steve and Jeff (cc'ed) would be best suited to answer your cifs.ko
> questions.
> In terms of where to start, I'd suggest pulling down the latest mainline
> kernel source tree with Git, building a kernel with CONFIG_CIFS enabled,
> and then attempting to mount a Samba or Windows share.
> 
> Documentation/filesystems/inotify.txt may be worth a read if you're
> interested in change notification support.
> 

Yep, that'd be a place to start. Note that we used to have a dir_notify
inode or dentry operation, but Al Viro ripped it out a few years ago
since it was broken by design. You might want to hunt down that
changeset and familiarize yourself with his objections if you're
looking to do that project.

-- 
Jeff Layton <jlayton at redhat.com>