NFSD: Clean up nfsd4_init_file()

Name this function more consistently. I'm going to use nfsd4_file_
and nfsd4_file_hash_ for these helpers.

Change the @fh parameter to be const pointer for better type safety.

Finally, move the hash insertion operation to the caller. This is
typical for most other "init_object" type helpers, and it is where
most of the other nfs4_file hash table operations are located.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

fs/nfsd/nfs4state.c

@@ -4277,11 +4277,9 @@ static struct nfs4_file *nfsd4_alloc_file(void)
 }
 
 /* OPEN Share state helper functions */
-static void nfsd4_init_file(struct svc_fh *fh, unsigned int hashval,
- struct nfs4_file *fp)
-{
- lockdep_assert_held(&state_lock);
 
+static void nfsd4_file_init(const struct svc_fh *fh, struct nfs4_file *fp)
+{
  refcount_set(&fp->fi_ref, 1);
  spin_lock_init(&fp->fi_lock);
  INIT_LIST_HEAD(&fp->fi_stateids);
@@ -4299,7 +4297,6 @@ static void nfsd4_init_file(struct svc_fh *fh, unsigned int hashval,
  INIT_LIST_HEAD(&fp->fi_lo_states);
  atomic_set(&fp->fi_lo_recalls, 0);
 #endif
- hlist_add_head_rcu(&fp->fi_hash, &file_hashtbl[hashval]);
 }
 
 void
@@ -4717,7 +4714,8 @@ static struct nfs4_file *insert_file(struct nfs4_file *new, struct svc_fh *fh,
  fp->fi_aliased = alias_found = true;
  }
  if (likely(ret == NULL)) {
- nfsd4_init_file(fh, hashval, new);
+ nfsd4_file_init(fh, new);
+ hlist_add_head_rcu(&new->fi_hash, &file_hashtbl[hashval]);
  new->fi_aliased = alias_found;
  ret = new;
  }