> On Thu, 2 Sept 2021 at 09:18, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > > > Your attitude seems to be that this is a btrfs problem and must be > > > fixed in btrfs. > > > > Yes. > > st_ino space issues affect overlayfs as well. The two problems are > not the same, but do share some characteristics. And this limitation will likely > come up again in the future. > > I suspect the long term solution would involve introducing new userspace API > (variable length inode numbers) and deprecating st_ino. > E.g. make stat return an error if the inode number doesn't fit into st_ino and add > a statx extension to return the full number. But this would be a long process... But then what do we do where fileid in NFS is only 64 bits? The solution of giving each subvol a separate fsid is the only real solution to enlarging the NFS fileid space, however that has downsides on the client side. Frank
