PMFJI, I think the problem is the assumption that the volume has to
be searched in the first place. Most file systems can open an inode
very efficiently when given an inode number.
The Linux VFS currently offers the iget function to retrieve an inode
when given an inode number. Unfortunately, this interface is not very
reliable when it comes to error checking, like when the client gives a
stale handle. Nevertheless, this is IMHO the route to go. You can
either extend the read_inode operation to support better error
reporting for deleted inodes, or introduce new interface.
Searching the entire volume is not an option, IMHO - at least not on
file systems that have the clear notion of inode numbers.
Regards,
Martin