nfsd: Add a struct nfs4_file field to struct nfs4_stid

All stateids are associated with a nfs4_file. Let's consolidate.
Replace delegation->dl_file with the dl_stid.sc_file, and
nfs4_ol_stateid->st_file with st_stid.sc_file.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 8574c70..e0be57b 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -337,7 +337,7 @@
 	p = xdr_reserve_space(xdr, 4);
 	*p++ = xdr_zero;			/* truncate */
 
-	encode_nfs_fh4(xdr, &dp->dl_file->fi_fhandle);
+	encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
 
 	hdr->nops++;
 }
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 60ab22b..344cd1a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -515,10 +515,6 @@
 
 static void nfs4_free_deleg(struct nfs4_stid *stid)
 {
-	struct nfs4_delegation *dp = delegstateid(stid);
-
-	if (dp->dl_file)
-		put_nfs4_file(dp->dl_file);
 	kmem_cache_free(deleg_slab, stid);
 	atomic_long_dec(&num_delegations);
 }
@@ -636,12 +632,15 @@
 void
 nfs4_put_stid(struct nfs4_stid *s)
 {
+	struct nfs4_file *fp = s->sc_file;
 	struct nfs4_client *clp = s->sc_client;
 
 	if (!atomic_dec_and_test(&s->sc_count))
 		return;
 	idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id);
 	s->sc_free(s);
+	if (fp)
+		put_nfs4_file(fp);
 }
 
 static void nfs4_put_deleg_lease(struct nfs4_file *fp)
@@ -677,7 +676,7 @@
 static void
 unhash_delegation_locked(struct nfs4_delegation *dp)
 {
-	struct nfs4_file *fp = dp->dl_file;
+	struct nfs4_file *fp = dp->dl_stid.sc_file;
 
 	lockdep_assert_held(&state_lock);
 
@@ -864,7 +863,7 @@
 
 	/* Recalculate per-file deny mode if there was a change */
 	if (change)
-		recalculate_deny_mode(stp->st_file);
+		recalculate_deny_mode(stp->st_stid.sc_file);
 }
 
 /* release all access and file references for a given stateid */
@@ -872,21 +871,21 @@
 release_all_access(struct nfs4_ol_stateid *stp)
 {
 	int i;
-	struct nfs4_file *fp = stp->st_file;
+	struct nfs4_file *fp = stp->st_stid.sc_file;
 
 	if (fp && stp->st_deny_bmap != 0)
 		recalculate_deny_mode(fp);
 
 	for (i = 1; i < 4; i++) {
 		if (test_access(i, stp))
-			nfs4_file_put_access(stp->st_file, i);
+			nfs4_file_put_access(stp->st_stid.sc_file, i);
 		clear_access(i, stp);
 	}
 }
 
 static void unhash_generic_stateid(struct nfs4_ol_stateid *stp)
 {
-	struct nfs4_file *fp = stp->st_file;
+	struct nfs4_file *fp = stp->st_stid.sc_file;
 
 	spin_lock(&fp->fi_lock);
 	list_del(&stp->st_perfile);
@@ -899,8 +898,6 @@
 	struct nfs4_ol_stateid *stp = openlockstateid(stid);
 
 	release_all_access(stp);
-	if (stp->st_file)
-		put_nfs4_file(stp->st_file);
 	kmem_cache_free(stateid_slab, stid);
 }
 
@@ -911,7 +908,7 @@
 	list_del(&stp->st_locks);
 	unhash_generic_stateid(stp);
 	unhash_stid(&stp->st_stid);
-	file = find_any_file(stp->st_file);
+	file = find_any_file(stp->st_stid.sc_file);
 	if (file)
 		filp_close(file, (fl_owner_t)lockowner(stp->st_stateowner));
 	nfs4_put_stid(&stp->st_stid);
@@ -2976,7 +2973,7 @@
 	list_add(&stp->st_perstateowner, &oo->oo_owner.so_stateids);
 	stp->st_stateowner = &oo->oo_owner;
 	get_nfs4_file(fp);
-	stp->st_file = fp;
+	stp->st_stid.sc_file = fp;
 	stp->st_access_bmap = 0;
 	stp->st_deny_bmap = 0;
 	stp->st_openstp = NULL;
@@ -3097,10 +3094,10 @@
 
 void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp)
 {
-	struct nfs4_client *clp = dp->dl_stid.sc_client;
-	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct nfsd_net *nn = net_generic(dp->dl_stid.sc_client->net,
+					  nfsd_net_id);
 
-	block_delegations(&dp->dl_file->fi_fhandle);
+	block_delegations(&dp->dl_stid.sc_file->fi_fhandle);
 
 	/*
 	 * We can't do this in nfsd_break_deleg_cb because it is
@@ -3508,7 +3505,7 @@
 
 static int nfs4_setlease(struct nfs4_delegation *dp)
 {
-	struct nfs4_file *fp = dp->dl_file;
+	struct nfs4_file *fp = dp->dl_stid.sc_file;
 	struct file_lock *fl;
 	struct file *filp;
 	int status = 0;
@@ -3573,7 +3570,7 @@
 	get_nfs4_file(fp);
 	spin_lock(&state_lock);
 	spin_lock(&fp->fi_lock);
-	dp->dl_file = fp;
+	dp->dl_stid.sc_file = fp;
 	if (!fp->fi_lease) {
 		spin_unlock(&fp->fi_lock);
 		spin_unlock(&state_lock);
@@ -3669,7 +3666,7 @@
 		default:
 			goto out_no_deleg;
 	}
-	dp = nfs4_set_delegation(clp, fh, stp->st_file);
+	dp = nfs4_set_delegation(clp, fh, stp->st_stid.sc_file);
 	if (IS_ERR(dp))
 		goto out_no_deleg;
 
@@ -3959,7 +3956,7 @@
 
 static inline __be32 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_ol_stateid *stp)
 {
-	if (!nfsd_fh_match(&fhp->fh_handle, &stp->st_file->fi_fhandle))
+	if (!nfsd_fh_match(&fhp->fh_handle, &stp->st_stid.sc_file->fi_fhandle))
 		return nfserr_bad_stateid;
 	return nfs_ok;
 }
@@ -4167,7 +4164,7 @@
 		if (status)
 			goto out;
 		if (filpp) {
-			file = dp->dl_file->fi_deleg_file;
+			file = dp->dl_stid.sc_file->fi_deleg_file;
 			if (!file) {
 				WARN_ON_ONCE(1);
 				status = nfserr_serverfault;
@@ -4189,10 +4186,12 @@
 		if (status)
 			goto out;
 		if (filpp) {
+			struct nfs4_file *fp = stp->st_stid.sc_file;
+
 			if (flags & RD_STATE)
-				file = find_readable_file(stp->st_file);
+				file = find_readable_file(fp);
 			else
-				file = find_writeable_file(stp->st_file);
+				file = find_writeable_file(fp);
 		}
 		break;
 	default:
@@ -4212,7 +4211,7 @@
 {
 	struct nfs4_lockowner *lo = lockowner(stp->st_stateowner);
 
-	if (check_for_locks(stp->st_file, lo))
+	if (check_for_locks(stp->st_stid.sc_file, lo))
 		return nfserr_locks_held;
 	release_lockowner_if_empty(lo);
 	return nfs_ok;
@@ -4403,7 +4402,7 @@
 {
 	if (!test_access(access, stp))
 		return;
-	nfs4_file_put_access(stp->st_file, access);
+	nfs4_file_put_access(stp->st_stid.sc_file, access);
 	clear_access(access, stp);
 }
 
@@ -4492,9 +4491,9 @@
 		 * before returning however.
 		 */
 		release_all_access(s);
-		if (s->st_file) {
-			put_nfs4_file(s->st_file);
-			s->st_file = NULL;
+		if (s->st_stid.sc_file) {
+			put_nfs4_file(s->st_stid.sc_file);
+			s->st_stid.sc_file = NULL;
 		}
 		oo->oo_last_closed_stid = s;
 		if (list_empty(&oo->oo_owner.so_stateids))
@@ -4695,7 +4694,7 @@
 	list_add(&stp->st_perstateowner, &lo->lo_owner.so_stateids);
 	stp->st_stateowner = &lo->lo_owner;
 	get_nfs4_file(fp);
-	stp->st_file = fp;
+	stp->st_stid.sc_file = fp;
 	stp->st_access_bmap = 0;
 	stp->st_deny_bmap = open_stp->st_deny_bmap;
 	stp->st_openstp = open_stp;
@@ -4712,7 +4711,7 @@
 	struct nfs4_ol_stateid *lst;
 
 	list_for_each_entry(lst, &lo->lo_owner.so_stateids, st_perstateowner) {
-		if (lst->st_file == fp)
+		if (lst->st_stid.sc_file == fp)
 			return lst;
 	}
 	return NULL;
@@ -4728,7 +4727,7 @@
 
 static void get_lock_access(struct nfs4_ol_stateid *lock_stp, u32 access)
 {
-	struct nfs4_file *fp = lock_stp->st_file;
+	struct nfs4_file *fp = lock_stp->st_stid.sc_file;
 
 	lockdep_assert_held(&fp->fi_lock);
 
@@ -4740,7 +4739,7 @@
 
 static __be32 lookup_or_create_lock_state(struct nfsd4_compound_state *cstate, struct nfs4_ol_stateid *ost, struct nfsd4_lock *lock, struct nfs4_ol_stateid **lst, bool *new)
 {
-	struct nfs4_file *fi = ost->st_file;
+	struct nfs4_file *fi = ost->st_stid.sc_file;
 	struct nfs4_openowner *oo = openowner(ost->st_stateowner);
 	struct nfs4_client *cl = oo->oo_owner.so_client;
 	struct inode *inode = cstate->current_fh.fh_dentry->d_inode;
@@ -4865,7 +4864,7 @@
 		goto out;
 	}
 
-	fp = lock_stp->st_file;
+	fp = lock_stp->st_stid.sc_file;
 	locks_init_lock(file_lock);
 	switch (lock->lk_type) {
 		case NFS4_READ_LT:
@@ -5065,7 +5064,7 @@
 					&stp, nn);
 	if (status)
 		goto out;
-	filp = find_any_file(stp->st_file);
+	filp = find_any_file(stp->st_stid.sc_file);
 	if (!filp) {
 		status = nfserr_lock_range;
 		goto out;
@@ -5188,7 +5187,7 @@
 	lo = lockowner(sop);
 	/* see if there are still any locks associated with it */
 	list_for_each_entry(stp, &sop->so_stateids, st_perstateowner) {
-		if (check_for_locks(stp->st_file, lo))
+		if (check_for_locks(stp->st_stid.sc_file, lo))
 			goto out;
 	}
 
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 32c4662..af1d9c4 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -85,6 +85,7 @@
 	unsigned char sc_type;
 	stateid_t sc_stateid;
 	struct nfs4_client *sc_client;
+	struct nfs4_file *sc_file;
 	void (*sc_free)(struct nfs4_stid *);
 };
 
@@ -93,7 +94,6 @@
 	struct list_head	dl_perfile;
 	struct list_head	dl_perclnt;
 	struct list_head	dl_recall_lru;  /* delegation recalled */
-	struct nfs4_file	*dl_file;
 	u32			dl_type;
 	time_t			dl_time;
 /* For recall: */
@@ -407,7 +407,6 @@
 	struct list_head              st_perstateowner;
 	struct list_head              st_locks;
 	struct nfs4_stateowner      * st_stateowner;
-	struct nfs4_file            * st_file;
 	unsigned char                 st_access_bmap;
 	unsigned char                 st_deny_bmap;
 	struct nfs4_ol_stateid         * st_openstp;