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>

2 files changed, 181 insertions, 72 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;
 }