Re: any idea about auto export multiple btrfs snapshots?

NeilBrown
2021-06-21T05:13:37Z

> > It seems more fixes are needed.
>
> I think the problem is that the submount doesn't appear in /proc/mounts.
> "nfsd_fh()" in nfs-utils needs to be able to map from the uuid for a
> filesystem to the mount point. To do this it walks through /proc/mounts
> checking the uuid of each filesystem. If a filesystem isn't listed
> there, it obviously fails.
>
> I guess you could add code to nfs-utils to do whatever "btrfs subvol
> list" does to make up for the fact that btrfs doesn't register in
> /proc/mounts.

Another approach might be to just change svcxdr_encode_fattr3() and
nfsd4_encode_fattr() in the 'FSIDSOJURCE_UUID' case to check if
dentry->d_inode has a different btrfs volume id to
exp->ex_path.dentry->d_inode.
If it does, then mix the volume id into the fsid somehow.

With that, you wouldn't want the first change I suggested.

NeilBrown