NFS: Move cl_state_owners and related fields to the nfs_server struct

NFSv4 migration needs to reassociate state owners from the source to
the destination nfs_server data structures.  To make that easier, move
the cl_state_owners field to the nfs_server struct.  cl_openowner_id
and cl_lockowner_id accompany this move, as they are used in
conjunction with cl_state_owners.

The cl_lock field in the parent nfs_client continues to protect all
three of these fields.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 186 insertions, 76 deletions

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 18d64cb5985b..7a7474073148 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -110,7 +110,7 @@ struct nfs_unique_id {
 struct nfs4_state_owner {
 	struct nfs_unique_id so_owner_id;
 	struct nfs_server    *so_server;
-	struct rb_node	     so_client_node;
+	struct rb_node	     so_server_node;
 
 	struct rpc_cred	     *so_cred;	 /* Associated cred */
 
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 286084f148e3..2336d532cf66 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -105,14 +105,17 @@ static void nfs4_clear_machine_cred(struct nfs_client *clp)
 		put_rpccred(cred);
 }
 
-struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
+static struct rpc_cred *
+nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 {
+	struct rpc_cred *cred = NULL;
 	struct nfs4_state_owner *sp;
 	struct rb_node *pos;
-	struct rpc_cred *cred = NULL;
 
-	for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
-		sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
+	for (pos = rb_first(&server->state_owners);
+	     pos != NULL;
+	     pos = rb_next(pos)) {
+		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 		if (list_empty(&sp->so_states))
 			continue;
 		cred = get_rpccred(sp->so_cred);
@@ -121,6 +124,28 @@ struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
 	return cred;
 }
 
+/**
+ * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
+ * @clp: client state handle
+ *
+ * Returns an rpc_cred with reference count bumped, or NULL.
+ * Caller must hold clp->cl_lock.
+ */
+struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
+{
+	struct rpc_cred *cred = NULL;
+	struct nfs_server *server;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		cred = nfs4_get_renew_cred_server_locked(server);
+		if (cred != NULL)
+			break;
+	}
+	rcu_read_unlock();
+	return cred;
+}
+
 #if defined(CONFIG_NFS_V4_1)
 
 static int nfs41_setup_state_renewal(struct nfs_client *clp)
@@ -231,28 +256,56 @@ struct rpc_cred *nfs4_get_exchange_id_cred(struct nfs_client *clp)
 
 #endif /* CONFIG_NFS_V4_1 */
 
-struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
+static struct rpc_cred *
+nfs4_get_setclientid_cred_server(struct nfs_server *server)
 {
+	struct nfs_client *clp = server->nfs_client;
+	struct rpc_cred *cred = NULL;
 	struct nfs4_state_owner *sp;
 	struct rb_node *pos;
+
+	spin_lock(&clp->cl_lock);
+	pos = rb_first(&server->state_owners);
+	if (pos != NULL) {
+		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
+		cred = get_rpccred(sp->so_cred);
+	}
+	spin_unlock(&clp->cl_lock);
+	return cred;
+}
+
+/**
+ * nfs4_get_setclientid_cred - Acquire credential for a setclientid operation
+ * @clp: client state handle
+ *
+ * Returns an rpc_cred with reference count bumped, or NULL.
+ */
+struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
+{
+	struct nfs_server *server;
 	struct rpc_cred *cred;
 
 	spin_lock(&clp->cl_lock);
 	cred = nfs4_get_machine_cred_locked(clp);
+	spin_unlock(&clp->cl_lock);
 	if (cred != NULL)
 		goto out;
-	pos = rb_first(&clp->cl_state_owners);
-	if (pos != NULL) {
-		sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
-		cred = get_rpccred(sp->so_cred);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		cred = nfs4_get_setclientid_cred_server(server);
+		if (cred != NULL)
+			break;
 	}
+	rcu_read_unlock();
+
 out:
-	spin_unlock(&clp->cl_lock);
 	return cred;
 }
 
-static void nfs_alloc_unique_id(struct rb_root *root, struct nfs_unique_id *new,
-		__u64 minval, int maxbits)
+static void nfs_alloc_unique_id_locked(struct rb_root *root,
+				       struct nfs_unique_id *new,
+				       __u64 minval, int maxbits)
 {
 	struct rb_node **p, *parent;
 	struct nfs_unique_id *pos;
@@ -307,16 +360,15 @@ static void nfs_free_unique_id(struct rb_root *root, struct nfs_unique_id *id)
 }
 
 static struct nfs4_state_owner *
-nfs4_find_state_owner(struct nfs_server *server, struct rpc_cred *cred)
+nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
 {
-	struct nfs_client *clp = server->nfs_client;
-	struct rb_node **p = &clp->cl_state_owners.rb_node,
+	struct rb_node **p = &server->state_owners.rb_node,
 		       *parent = NULL;
 	struct nfs4_state_owner *sp, *res = NULL;
 
 	while (*p != NULL) {
 		parent = *p;
-		sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
+		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 
 		if (server < sp->so_server) {
 			p = &parent->rb_left;
@@ -340,24 +392,17 @@ nfs4_find_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 }
 
 static struct nfs4_state_owner *
-nfs4_insert_state_owner(struct nfs_client *clp, struct nfs4_state_owner *new)
+nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 {
-	struct rb_node **p = &clp->cl_state_owners.rb_node,
+	struct nfs_server *server = new->so_server;
+	struct rb_node **p = &server->state_owners.rb_node,
 		       *parent = NULL;
 	struct nfs4_state_owner *sp;
 
 	while (*p != NULL) {
 		parent = *p;
-		sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
+		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 
-		if (new->so_server < sp->so_server) {
-			p = &parent->rb_left;
-			continue;
-		}
-		if (new->so_server > sp->so_server) {
-			p = &parent->rb_right;
-			continue;
-		}
 		if (new->so_cred < sp->so_cred)
 			p = &parent->rb_left;
 		else if (new->so_cred > sp->so_cred)
@@ -367,18 +412,21 @@ nfs4_insert_state_owner(struct nfs_client *clp, struct nfs4_state_owner *new)
 			return sp;
 		}
 	}
-	nfs_alloc_unique_id(&clp->cl_openowner_id, &new->so_owner_id, 1, 64);
-	rb_link_node(&new->so_client_node, parent, p);
-	rb_insert_color(&new->so_client_node, &clp->cl_state_owners);
+	nfs_alloc_unique_id_locked(&server->openowner_id,
+					&new->so_owner_id, 1, 64);
+	rb_link_node(&new->so_server_node, parent, p);
+	rb_insert_color(&new->so_server_node, &server->state_owners);
 	return new;
 }
 
 static void
-nfs4_remove_state_owner(struct nfs_client *clp, struct nfs4_state_owner *sp)
+nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 {
-	if (!RB_EMPTY_NODE(&sp->so_client_node))
-		rb_erase(&sp->so_client_node, &clp->cl_state_owners);
-	nfs_free_unique_id(&clp->cl_openowner_id, &sp->so_owner_id);
+	struct nfs_server *server = sp->so_server;
+
+	if (!RB_EMPTY_NODE(&sp->so_server_node))
+		rb_erase(&sp->so_server_node, &server->state_owners);
+	nfs_free_unique_id(&server->openowner_id, &sp->so_owner_id);
 }
 
 /*
@@ -407,23 +455,32 @@ nfs4_alloc_state_owner(void)
 static void
 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 {
-	if (!RB_EMPTY_NODE(&sp->so_client_node)) {
-		struct nfs_client *clp = sp->so_server->nfs_client;
+	if (!RB_EMPTY_NODE(&sp->so_server_node)) {
+		struct nfs_server *server = sp->so_server;
+		struct nfs_client *clp = server->nfs_client;
 
 		spin_lock(&clp->cl_lock);
-		rb_erase(&sp->so_client_node, &clp->cl_state_owners);
-		RB_CLEAR_NODE(&sp->so_client_node);
+		rb_erase(&sp->so_server_node, &server->state_owners);
+		RB_CLEAR_NODE(&sp->so_server_node);
 		spin_unlock(&clp->cl_lock);
 	}
 }
 
-struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
+/**
+ * nfs4_get_state_owner - Look up a state owner given a credential
+ * @server: nfs_server to search
+ * @cred: RPC credential to match
+ *
+ * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
+ */
+struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
+					      struct rpc_cred *cred)
 {
 	struct nfs_client *clp = server->nfs_client;
 	struct nfs4_state_owner *sp, *new;
 
 	spin_lock(&clp->cl_lock);
-	sp = nfs4_find_state_owner(server, cred);
+	sp = nfs4_find_state_owner_locked(server, cred);
 	spin_unlock(&clp->cl_lock);
 	if (sp != NULL)
 		return sp;
@@ -433,7 +490,7 @@ struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct
 	new->so_server = server;
 	new->so_cred = cred;
 	spin_lock(&clp->cl_lock);
-	sp = nfs4_insert_state_owner(clp, new);
+	sp = nfs4_insert_state_owner_locked(new);
 	spin_unlock(&clp->cl_lock);
 	if (sp == new)
 		get_rpccred(cred);
@@ -444,6 +501,11 @@ struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct
 	return sp;
 }
 
+/**
+ * nfs4_put_state_owner - Release a nfs4_state_owner
+ * @sp: state owner data to release
+ *
+ */
 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 {
 	struct nfs_client *clp = sp->so_server->nfs_client;
@@ -451,7 +513,7 @@ void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 
 	if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 		return;
-	nfs4_remove_state_owner(clp, sp);
+	nfs4_remove_state_owner_locked(sp);
 	spin_unlock(&clp->cl_lock);
 	rpc_destroy_wait_queue(&sp->so_sequence.wait);
 	put_rpccred(cred);
@@ -657,7 +719,8 @@ __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_p
 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
 {
 	struct nfs4_lock_state *lsp;
-	struct nfs_client *clp = state->owner->so_server->nfs_client;
+	struct nfs_server *server = state->owner->so_server;
+	struct nfs_client *clp = server->nfs_client;
 
 	lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
 	if (lsp == NULL)
@@ -681,7 +744,7 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f
 		return NULL;
 	}
 	spin_lock(&clp->cl_lock);
-	nfs_alloc_unique_id(&clp->cl_lockowner_id, &lsp->ls_id, 1, 64);
+	nfs_alloc_unique_id_locked(&server->lockowner_id, &lsp->ls_id, 1, 64);
 	spin_unlock(&clp->cl_lock);
 	INIT_LIST_HEAD(&lsp->ls_locks);
 	return lsp;
@@ -689,10 +752,11 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f
 
 static void nfs4_free_lock_state(struct nfs4_lock_state *lsp)
 {
-	struct nfs_client *clp = lsp->ls_state->owner->so_server->nfs_client;
+	struct nfs_server *server = lsp->ls_state->owner->so_server;
+	struct nfs_client *clp = server->nfs_client;
 
 	spin_lock(&clp->cl_lock);
-	nfs_free_unique_id(&clp->cl_lockowner_id, &lsp->ls_id);
+	nfs_free_unique_id(&server->lockowner_id, &lsp->ls_id);
 	spin_unlock(&clp->cl_lock);
 	rpc_destroy_wait_queue(&lsp->ls_sequence.wait);
 	kfree(lsp);
@@ -1138,15 +1202,19 @@ static void nfs4_clear_open_state(struct nfs4_state *state)
 	}
 }
 
-static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp, int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
+static void nfs4_reset_seqids(struct nfs_server *server,
+	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
 {
+	struct nfs_client *clp = server->nfs_client;
 	struct nfs4_state_owner *sp;
 	struct rb_node *pos;
 	struct nfs4_state *state;
 
-	/* Reset all sequence ids to zero */
-	for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
-		sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
+	spin_lock(&clp->cl_lock);
+	for (pos = rb_first(&server->state_owners);
+	     pos != NULL;
+	     pos = rb_next(pos)) {
+		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 		sp->so_seqid.flags = 0;
 		spin_lock(&sp->so_lock);
 		list_for_each_entry(state, &sp->so_states, open_states) {
@@ -1155,6 +1223,18 @@ static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp, int (*mark_re
 		}
 		spin_unlock(&sp->so_lock);
 	}
+	spin_unlock(&clp->cl_lock);
+}
+
+static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
+	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
+{
+	struct nfs_server *server;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		nfs4_reset_seqids(server, mark_reclaim);
+	rcu_read_unlock();
 }
 
 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
@@ -1172,25 +1252,41 @@ static void nfs4_reclaim_complete(struct nfs_client *clp,
 		(void)ops->reclaim_complete(clp);
 }
 
-static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
+static void nfs4_clear_reclaim_server(struct nfs_server *server)
 {
+	struct nfs_client *clp = server->nfs_client;
 	struct nfs4_state_owner *sp;
 	struct rb_node *pos;
 	struct nfs4_state *state;
 
-	if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
-		return 0;
-
-	for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
-		sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
+	spin_lock(&clp->cl_lock);
+	for (pos = rb_first(&server->state_owners);
+	     pos != NULL;
+	     pos = rb_next(pos)) {
+		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 		spin_lock(&sp->so_lock);
 		list_for_each_entry(state, &sp->so_states, open_states) {
-			if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags))
+			if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
+						&state->flags))
 				continue;
 			nfs4_state_mark_reclaim_nograce(clp, state);
 		}
 		spin_unlock(&sp->so_lock);
 	}
+	spin_unlock(&clp->cl_lock);
+}
+
+static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
+{
+	struct nfs_server *server;
+
+	if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
+		return 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		nfs4_clear_reclaim_server(server);
+	rcu_read_unlock();
 
 	nfs_delegation_reap_unclaimed(clp);
 	return 1;
@@ -1262,27 +1358,40 @@ static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
 
 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
 {
+	struct nfs4_state_owner *sp;
+	struct nfs_server *server;
 	struct rb_node *pos;
 	int status = 0;
 
 restart:
-	spin_lock(&clp->cl_lock);
-	for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
-		struct nfs4_state_owner *sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
-		if (!test_and_clear_bit(ops->owner_flag_bit, &sp->so_flags))
-			continue;
-		atomic_inc(&sp->so_count);
-		spin_unlock(&clp->cl_lock);
-		status = nfs4_reclaim_open_state(sp, ops);
-		if (status < 0) {
-			set_bit(ops->owner_flag_bit, &sp->so_flags);
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		spin_lock(&clp->cl_lock);
+		for (pos = rb_first(&server->state_owners);
+		     pos != NULL;
+		     pos = rb_next(pos)) {
+			sp = rb_entry(pos,
+				struct nfs4_state_owner, so_server_node);
+			if (!test_and_clear_bit(ops->owner_flag_bit,
+							&sp->so_flags))
+				continue;
+			atomic_inc(&sp->so_count);
+			spin_unlock(&clp->cl_lock);
+			rcu_read_unlock();
+
+			status = nfs4_reclaim_open_state(sp, ops);
+			if (status < 0) {
+				set_bit(ops->owner_flag_bit, &sp->so_flags);
+				nfs4_put_state_owner(sp);
+				return nfs4_recovery_handle_error(clp, status);
+			}
+
 			nfs4_put_state_owner(sp);
-			return nfs4_recovery_handle_error(clp, status);
+			goto restart;
 		}
-		nfs4_put_state_owner(sp);
-		goto restart;
+		spin_unlock(&clp->cl_lock);
 	}
-	spin_unlock(&clp->cl_lock);
+	rcu_read_unlock();
 	return status;
 }
 
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 7f20c0b47a91..27255ffdbe10 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -47,11 +47,7 @@ struct nfs_client {
 	u64			cl_clientid;	/* constant */
 	unsigned long		cl_state;
 
-	struct rb_root		cl_openowner_id;
-	struct rb_root		cl_lockowner_id;
-
 	struct list_head	cl_delegations;
-	struct rb_root		cl_state_owners;
 	spinlock_t		cl_lock;
 
 	unsigned long		cl_lease_time;
@@ -150,6 +146,11 @@ struct nfs_server {
 						   filesystem */
 	struct pnfs_layoutdriver_type  *pnfs_curr_ld; /* Active layout driver */
 	struct rpc_wait_queue	roc_rpcwaitq;
+
+	/* the following fields are protected by nfs_client->cl_lock */
+	struct rb_root		state_owners;
+	struct rb_root		openowner_id;
+	struct rb_root		lockowner_id;
 #endif
 	void (*destroy)(struct nfs_server *);