nfsd4_locku / nfs4_free_lock_stateid question

[Christoph Hellwig <hch@infradead.org>]

Hi Jeff,

while reviewing some of your patches I've started wondering about
some v4 locking code.

In nfsd4_locku we're doing a call to find_any_file to grab a file
structure for the lock stateid, which nfs4_free_lock_stateid tries to
close. But what guarantees that we're actually getting the same file
descriptor back?

The nfs4_file is shared by and stateid that access a given inode,
so the first call to find_any_file might return the read/only file
structure because that's the only one available so far, while
by the time we unlock we might have a read/write and/or write-only file
available as well, which find_any_file will return.

It seems like the lock stateid needs a pointer to the actual file
locked, and keep a reference to it independent of the nfs4_file, or am I
missing something?