vnodes and hard links

[Frank Zerangue <frank.zerangue%gmail.com@localhost>]

I am confused about what vnode operation vop_lookup_desc should return for two 
directory entries that refer to the same underling filesystem inode (i.e. hard 
links).

//      VNODE(9): There is a unique vnode allocated for each active file, 
directory, mounted-on file, fifo, domain socket, symbolic link and device."

Does this mean that (1) a unique vnode per directory entry or (2) a unique 
vnode per inode ?

I suspect that the answer is (2), but when I do this and just return the 
already locked vnode, I get this assertion.

//      Reader / writer lock error: rw_vector_exit: assertion failed: 
RW_COUNT(rw) != 0

Examples from other filesystems in the code base either do the same or perform 
a vget() based some flags, but if the vnode is active it would not be on the 
free list. 

Any suggestions? 

Thanks,
FrankZ