Mapping inode numbers to file names

[Edward Ned Harvey]

Let's suppose you rename a file or directory.

/tank/widgets/a/rel2049_773.13-4/somefile.txt

Becomes

/tank/widgets/b/foogoo_release_1.9/README

 

Let's suppose you are now working on widget B, and you want to look at the
past zfs snapshot of README, but you don't remember where it came from.
That is, you don't know the previous name or location where that file used
to be.  One way you could do it would be:

 

Look up the inode number of README.  (for example, ls -i README)

                (suppose it's inode 12345)

find /tank/.zfs/snapshot -inum 12345

 

Problem is, the find command will run for a long time.

 

Is there any faster way to find the file name(s) when all you know is the
inode number?  (Actually, all you know is all the info that's in the present
directory, which is not limited to inode number; but, inode number is the
only information that I personally know could be useful.)