Re: [patch 4/8] fs, exportfs: Add export_encode_inode_fh helper

[Marco Stornelli]

Il 23/08/2012 10:06, Cyrill Gorcunov ha scritto:
> On Wed, Aug 22, 2012 at 11:19:07AM +0530, Aneesh Kumar K.V wrote:
> > Pavel Emelyanov <xemul@xxxxxxxxxxxxx> writes:
> >
> > > Why? For e.g. ext4 you can construct a handle in userspace and open by
> > > it.
> >
> > open_by_handle use exportfs_decode_fh which use file system specific
> > fh_to_dentry
> >
> > foe ext4 we require a generation number
> >
> > 		inode = get_inode(sb, fid->i32.ino, fid->i32.gen);
>
> Hi Aneesh, yes we need i_generation but for ext3/4 it could be
> fetched with ioctl as far as i see.
>
> > For brtfs
> >
> > 	objectid = fid->objectid;
> > 	root_objectid = fid->root_objectid;
> > 	generation = fid->gen;
> >
> > 	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
>
> For btrfs it become more complex. But still the last version I'm about
> to send for review today (once everything get tested) will provide
> fhandle carried with inotify mark _and_ inode number and device. This
> information should be enough for us. After all having inode and device
> should allow us to figure out the fs used on inotify target.
>
> 	Cyrill
> --

Sorry if it's a really stupid question but I didn't follow deeply the 
thread. How can you provide a device if the fs is mounted on "none" (ex 
tmpfs)? In this case you can't associate device <=> fs, because you 
haven't got a /dev/something.

Marco
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/