On Sat, Apr 24, 2010 at 11:08:12AM +1000, Neil Brown wrote: > Maybe map the filesystem part of the handle from UUID (or whatever) to devno > in userspace, then pass the devno+file-part-of-handle to the kernel to > perform, the final mapping. The device number is not a useful kernel interface at all. Getting a uuid really is easy in kernelspace as it's available in the superblock for every reasonable fs. What's more difficult is finding the right vfsmount instance of a superblock to use - not just due to read only but also things like no* per-vfsmount flags. If you look at libhandle in xfsprogs which wraps the existing xfs handle ioctls for use in application you'll see such a hash table to map to open file descriptors per filesystems due to the limits of the ioctl interface. Doing the uuid lookup in kernelspace sounds much saner as we have a list of mounts there anyway. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
