NFS: Generalise the nfs_client structure

Generalise the nfs_client structure by:

 (1) Moving nfs_client to a more general place (nfs_fs_sb.h).

 (2) Renaming its maintenance routines to be non-NFS4 specific.

 (3) Move those maintenance routines to a new non-NFS4 specific file (client.c)
     and move the declarations to internal.h.

 (4) Make nfs_find/get_client() take a full sockaddr_in to include the port
     number (will be required for NFS2/3).

 (5) Make nfs_find/get_client() take the NFS protocol version (again will be
     required to differentiate NFS2, 3 & 4 client records).

Also:

 (6) Make nfs_client construction proceed akin to inodes, marking them as under
     construction and providing a function to indicate completion.

 (7) Make nfs_get_client() wait interruptibly if it finds a client that it can
     share, but that client is currently being constructed.

 (8) Make nfs4_create_client() use (6) and (7) instead of locking cl_sem.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

12 files changed, 425 insertions, 222 deletions

diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
index 0b572a0c1967..3b993a6f8163 100644
--- a/fs/nfs/Makefile
+++ b/fs/nfs/Makefile
@@ -4,9 +4,9 @@
 
 obj-$(CONFIG_NFS_FS) += nfs.o
 
-nfs-y                   := dir.o file.o inode.o super.o nfs2xdr.o pagelist.o \
-                           proc.o read.o symlink.o unlink.o write.o \
-                           namespace.o
+nfs-y                   := client.o dir.o file.o inode.o super.o nfs2xdr.o \
+                           pagelist.o proc.o read.o symlink.o unlink.o \
+                           write.o namespace.o
 nfs-$(CONFIG_ROOT_NFS)  += nfsroot.o mount_clnt.o      
 nfs-$(CONFIG_NFS_V3)    += nfs3proc.o nfs3xdr.o
 nfs-$(CONFIG_NFS_V3_ACL)        += nfs3acl.o
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 1b596b6d9dc2..a3ee11364db0 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -19,6 +19,7 @@
 
 #include "nfs4_fs.h"
 #include "callback.h"
+#include "internal.h"
 
 #define NFSDBG_FACILITY NFSDBG_CALLBACK
 
@@ -166,15 +167,15 @@ void nfs_callback_down(void)
 
 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
 {
-        struct in_addr *addr = &rqstp->rq_addr.sin_addr;
+        struct sockaddr_in *addr = &rqstp->rq_addr;
         struct nfs_client *clp;
 
         /* Don't talk to strangers */
-        clp = nfs4_find_client(addr);
+        clp = nfs_find_client(addr, 4);
         if (clp == NULL)
                 return SVC_DROP;
-        dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr));
-        nfs4_put_client(clp);
+        dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr->sin_addr));
+        nfs_put_client(clp);
         switch (rqstp->rq_authop->flavour) {
                 case RPC_AUTH_NULL:
                         if (rqstp->rq_proc != CB_NULL)
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 55d6e2ec157f..97cf8f71451f 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -10,6 +10,7 @@
 #include "nfs4_fs.h"
 #include "callback.h"
 #include "delegation.h"
+#include "internal.h"
 
 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  
@@ -22,7 +23,7 @@ unsigned nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getattrres
         
         res->bitmap[0] = res->bitmap[1] = 0;
         res->status = htonl(NFS4ERR_BADHANDLE);
-        clp = nfs4_find_client(&args->addr->sin_addr);
+        clp = nfs_find_client(args->addr, 4);
         if (clp == NULL)
                 goto out;
         inode = nfs_delegation_find_inode(clp, &args->fh);
@@ -48,7 +49,7 @@ out_iput:
         up_read(&nfsi->rwsem);
         iput(inode);
 out_putclient:
-        nfs4_put_client(clp);
+        nfs_put_client(clp);
 out:
         dprintk("%s: exit with status = %d\n", __FUNCTION__, ntohl(res->status));
         return res->status;
@@ -61,7 +62,7 @@ unsigned nfs4_callback_recall(struct cb_recallargs *args, void *dummy)
         unsigned res;
         
         res = htonl(NFS4ERR_BADHANDLE);
-        clp = nfs4_find_client(&args->addr->sin_addr);
+        clp = nfs_find_client(args->addr, 4);
         if (clp == NULL)
                 goto out;
         inode = nfs_delegation_find_inode(clp, &args->fh);
@@ -80,7 +81,7 @@ unsigned nfs4_callback_recall(struct cb_recallargs *args, void *dummy)
         }
         iput(inode);
 out_putclient:
-        nfs4_put_client(clp);
+        nfs_put_client(clp);
 out:
         dprintk("%s: exit with status = %d\n", __FUNCTION__, ntohl(res));
         return res;
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
new file mode 100644
index 000000000000..cb5e92463bdb
--- /dev/null
+++ b/fs/nfs/client.c
@@ -0,0 +1,312 @@
+/* client.c: NFS client sharing and management code
+ *
+ * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/metrics.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/nfs4_mount.h>
+#include <linux/lockd/bind.h>
+#include <linux/smp_lock.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/nfs_idmap.h>
+#include <linux/vfs.h>
+#include <linux/inet.h>
+#include <linux/nfs_xdr.h>
+
+#include <asm/system.h>
+
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "delegation.h"
+#include "iostat.h"
+#include "internal.h"
+
+#define NFSDBG_FACILITY         NFSDBG_CLIENT
+
+static DEFINE_SPINLOCK(nfs_client_lock);
+static LIST_HEAD(nfs_client_list);
+static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
+
+/*
+ * Allocate a shared client record
+ *
+ * Since these are allocated/deallocated very rarely, we don't
+ * bother putting them in a slab cache...
+ */
+static struct nfs_client *nfs_alloc_client(const char *hostname,
+                                           const struct sockaddr_in *addr,
+                                           int nfsversion)
+{
+        struct nfs_client *clp;
+        int error;
+
+        if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
+                goto error_0;
+
+        error = rpciod_up();
+        if (error < 0) {
+                dprintk("%s: couldn't start rpciod! Error = %d\n",
+                                __FUNCTION__, error);
+                __set_bit(NFS_CS_RPCIOD, &clp->cl_res_state);
+                goto error_1;
+        }
+
+        if (nfsversion == 4) {
+                if (nfs_callback_up() < 0)
+                        goto error_2;
+                __set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
+        }
+
+        atomic_set(&clp->cl_count, 1);
+        clp->cl_cons_state = NFS_CS_INITING;
+
+        clp->cl_nfsversion = nfsversion;
+        memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
+
+        if (hostname) {
+                clp->cl_hostname = kstrdup(hostname, GFP_KERNEL);
+                if (!clp->cl_hostname)
+                        goto error_3;
+        }
+
+        INIT_LIST_HEAD(&clp->cl_superblocks);
+        clp->cl_rpcclient = ERR_PTR(-EINVAL);
+
+#ifdef CONFIG_NFS_V4
+        init_rwsem(&clp->cl_sem);
+        INIT_LIST_HEAD(&clp->cl_delegations);
+        INIT_LIST_HEAD(&clp->cl_state_owners);
+        INIT_LIST_HEAD(&clp->cl_unused);
+        spin_lock_init(&clp->cl_lock);
+        INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
+        rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
+        clp->cl_boot_time = CURRENT_TIME;
+        clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
+#endif
+
+        return clp;
+
+error_3:
+        nfs_callback_down();
+        __clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
+error_2:
+        rpciod_down();
+        __clear_bit(NFS_CS_RPCIOD, &clp->cl_res_state);
+error_1:
+        kfree(clp);
+error_0:
+        return NULL;
+}
+
+/*
+ * Destroy a shared client record
+ */
+static void nfs_free_client(struct nfs_client *clp)
+{
+        dprintk("--> nfs_free_client(%d)\n", clp->cl_nfsversion);
+
+#ifdef CONFIG_NFS_V4
+        if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state)) {
+                while (!list_empty(&clp->cl_unused)) {
+                        struct nfs4_state_owner *sp;
+
+                        sp = list_entry(clp->cl_unused.next,
+                                        struct nfs4_state_owner,
+                                        so_list);
+                        list_del(&sp->so_list);
+                        kfree(sp);
+                }
+                BUG_ON(!list_empty(&clp->cl_state_owners));
+                nfs_idmap_delete(clp);
+        }
+#endif
+
+        /* -EIO all pending I/O */
+        if (!IS_ERR(clp->cl_rpcclient))
+                rpc_shutdown_client(clp->cl_rpcclient);
+
+        if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
+                nfs_callback_down();
+
+        if (__test_and_clear_bit(NFS_CS_RPCIOD, &clp->cl_res_state))
+        rpciod_down();
+
+        kfree(clp->cl_hostname);
+        kfree(clp);
+
+        dprintk("<-- nfs_free_client()\n");
+}
+
+/*
+ * Release a reference to a shared client record
+ */
+void nfs_put_client(struct nfs_client *clp)
+{
+        dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
+
+        if (atomic_dec_and_lock(&clp->cl_count, &nfs_client_lock)) {
+                list_del(&clp->cl_share_link);
+                spin_unlock(&nfs_client_lock);
+
+                BUG_ON(!list_empty(&clp->cl_superblocks));
+
+                nfs_free_client(clp);
+        }
+}
+
+/*
+ * Find a client by address
+ * - caller must hold nfs_client_lock
+ */
+static struct nfs_client *__nfs_find_client(const struct sockaddr_in *addr, int nfsversion)
+{
+        struct nfs_client *clp;
+
+        list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
+                /* Different NFS versions cannot share the same nfs_client */
+                if (clp->cl_nfsversion != nfsversion)
+                        continue;
+
+                if (memcmp(&clp->cl_addr.sin_addr, &addr->sin_addr,
+                           sizeof(clp->cl_addr.sin_addr)) != 0)
+                        continue;
+
+                if (clp->cl_addr.sin_port == addr->sin_port)
+                        goto found;
+        }
+
+        return NULL;
+
+found:
+        atomic_inc(&clp->cl_count);
+        return clp;
+}
+
+/*
+ * Find a client by IP address and protocol version
+ * - returns NULL if no such client
+ */
+struct nfs_client *nfs_find_client(const struct sockaddr_in *addr, int nfsversion)
+{
+        struct nfs_client *clp;
+
+        spin_lock(&nfs_client_lock);
+        clp = __nfs_find_client(addr, nfsversion);
+        spin_unlock(&nfs_client_lock);
+
+        BUG_ON(clp->cl_cons_state == 0);
+
+        return clp;
+}
+
+/*
+ * Look up a client by IP address and protocol version
+ * - creates a new record if one doesn't yet exist
+ */
+struct nfs_client *nfs_get_client(const char *hostname,
+                                  const struct sockaddr_in *addr,
+                                  int nfsversion)
+{
+        struct nfs_client *clp, *new = NULL;
+        int error;
+
+        dprintk("--> nfs_get_client(%s,"NIPQUAD_FMT":%d,%d)\n",
+                hostname ?: "", NIPQUAD(addr->sin_addr),
+                addr->sin_port, nfsversion);
+
+        /* see if the client already exists */
+        do {
+                spin_lock(&nfs_client_lock);
+
+                clp = __nfs_find_client(addr, nfsversion);
+                if (clp)
+                        goto found_client;
+                if (new)
+                        goto install_client;
+
+                spin_unlock(&nfs_client_lock);
+
+                new = nfs_alloc_client(hostname, addr, nfsversion);
+        } while (new);
+
+        return ERR_PTR(-ENOMEM);
+
+        /* install a new client and return with it unready */
+install_client:
+        clp = new;
+        list_add(&clp->cl_share_link, &nfs_client_list);
+        spin_unlock(&nfs_client_lock);
+        dprintk("--> nfs_get_client() = %p [new]\n", clp);
+        return clp;
+
+        /* found an existing client
+         * - make sure it's ready before returning
+         */
+found_client:
+        spin_unlock(&nfs_client_lock);
+
+        if (new)
+                nfs_free_client(new);
+
+        if (clp->cl_cons_state == NFS_CS_INITING) {
+                DECLARE_WAITQUEUE(myself, current);
+
+                add_wait_queue(&nfs_client_active_wq, &myself);
+
+                for (;;) {
+                        set_current_state(TASK_INTERRUPTIBLE);
+                        if (signal_pending(current) ||
+                            clp->cl_cons_state > NFS_CS_READY)
+                                break;
+                        schedule();
+                }
+
+                remove_wait_queue(&nfs_client_active_wq, &myself);
+
+                if (signal_pending(current)) {
+                        nfs_put_client(clp);
+                        return ERR_PTR(-ERESTARTSYS);
+                }
+        }
+
+        if (clp->cl_cons_state < NFS_CS_READY) {
+                error = clp->cl_cons_state;
+                nfs_put_client(clp);
+                return ERR_PTR(error);
+        }
+
+        dprintk("--> nfs_get_client() = %p [share]\n", clp);
+        return clp;
+}
+
+/*
+ * Mark a server as ready or failed
+ */
+void nfs_mark_client_ready(struct nfs_client *clp, int state)
+{
+        clp->cl_cons_state = state;
+        wake_up_all(&nfs_client_active_wq);
+}
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index cfe239736ac0..57133678db16 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -18,6 +18,7 @@
 
 #include "nfs4_fs.h"
 #include "delegation.h"
+#include "internal.h"
 
 static struct nfs_delegation *nfs_alloc_delegation(void)
 {
@@ -145,7 +146,7 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
                                         sizeof(delegation->stateid)) != 0 ||
                                 delegation->type != nfsi->delegation->type) {
                         printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
-                                        __FUNCTION__, NIPQUAD(clp->cl_addr));
+                                        __FUNCTION__, NIPQUAD(clp->cl_addr.sin_addr));
                         status = -EIO;
                 }
         }
@@ -254,7 +255,7 @@ restart:
         }
 out:
         spin_unlock(&clp->cl_lock);
-        nfs4_put_client(clp);
+        nfs_put_client(clp);
         module_put_and_exit(0);
 }
 
@@ -266,10 +267,10 @@ void nfs_expire_all_delegations(struct nfs_client *clp)
         atomic_inc(&clp->cl_count);
         task = kthread_run(nfs_do_expire_all_delegations, clp,
                         "%u.%u.%u.%u-delegreturn",
-                        NIPQUAD(clp->cl_addr));
+                        NIPQUAD(clp->cl_addr.sin_addr));
         if (!IS_ERR(task))
                 return;
-        nfs4_put_client(clp);
+        nfs_put_client(clp);
         module_put(THIS_MODULE);
 }
 
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 4802157963f8..ac370d5d4494 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -15,6 +15,12 @@ struct nfs_clone_mount {
         rpc_authflavor_t authflavor;
 };
 
+/* client.c */
+extern void nfs_put_client(struct nfs_client *);
+extern struct nfs_client *nfs_find_client(const struct sockaddr_in *, int);
+extern struct nfs_client *nfs_get_client(const char *, const struct sockaddr_in *, int);
+extern void nfs_mark_client_ready(struct nfs_client *, int);
+
 /* nfs4namespace.c */
 #ifdef CONFIG_NFS_V4
 extern struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry);
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 4e334cb48498..e7879245361e 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -43,55 +43,6 @@ enum nfs4_client_state {
 };
 
 /*
- * The nfs_client identifies our client state to the server.
- */
-struct nfs_client {
-        struct list_head        cl_servers;     /* Global list of servers */
-        struct in_addr          cl_addr;        /* Server identifier */
-        u64                     cl_clientid;    /* constant */
-        nfs4_verifier           cl_confirm;
-        unsigned long           cl_state;
-
-        u32                     cl_lockowner_id;
-
-        /*
-         * The following rwsem ensures exclusive access to the server
-         * while we recover the state following a lease expiration.
-         */
-        struct rw_semaphore     cl_sem;
-
-        struct list_head        cl_delegations;
-        struct list_head        cl_state_owners;
-        struct list_head        cl_unused;
-        int                     cl_nunused;
-        spinlock_t              cl_lock;
-        atomic_t                cl_count;
-
-        struct rpc_clnt *       cl_rpcclient;
-
-        struct list_head        cl_superblocks; /* List of nfs_server structs */
-
-        unsigned long           cl_lease_time;
-        unsigned long           cl_last_renewal;
-        struct work_struct      cl_renewd;
-        struct work_struct      cl_recoverd;
-
-        struct rpc_wait_queue   cl_rpcwaitq;
-
-        /* used for the setclientid verifier */
-        struct timespec         cl_boot_time;
-
-        /* idmapper */
-        struct idmap *          cl_idmap;
-
-        /* Our own IP address, as a null-terminated string.
-         * This is used to generate the clientid, and the callback address.
-         */
-        char                    cl_ipaddr[16];
-        unsigned char           cl_id_uniquifier;
-};
-
-/*
  * struct rpc_sequence ensures that RPC calls are sent in the exact
  * order that they appear on the list.
  */
@@ -239,9 +190,6 @@ extern void nfs4_renew_state(void *);
 /* nfs4state.c */
 extern void init_nfsv4_state(struct nfs_server *);
 extern void destroy_nfsv4_state(struct nfs_server *);
-extern struct nfs_client *nfs4_get_client(struct in_addr *);
-extern void nfs4_put_client(struct nfs_client *clp);
-extern struct nfs_client *nfs4_find_client(struct in_addr *);
 struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp);
 extern u32 nfs4_alloc_lockowner_id(struct nfs_client *);
 
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 850f0851023a..803c31b88bb5 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2968,7 +2968,7 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program, unsigned short po
         for(;;) {
                 setclientid.sc_name_len = scnprintf(setclientid.sc_name,
                                 sizeof(setclientid.sc_name), "%s/%u.%u.%u.%u %s %u",
-                                clp->cl_ipaddr, NIPQUAD(clp->cl_addr.s_addr),
+                                clp->cl_ipaddr, NIPQUAD(clp->cl_addr.sin_addr),
                                 cred->cr_ops->cr_name,
                                 clp->cl_id_uniquifier);
                 setclientid.sc_netid_len = scnprintf(setclientid.sc_netid,
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index fa51a7d4c022..058811e39555 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -50,12 +50,12 @@
 #include "nfs4_fs.h"
 #include "callback.h"
 #include "delegation.h"
+#include "internal.h"
 
 #define OPENOWNER_POOL_SIZE     8
 
 const nfs4_stateid zero_stateid;
 
-static DEFINE_SPINLOCK(state_spinlock);
 static LIST_HEAD(nfs4_clientid_list);
 
 void
@@ -71,127 +71,11 @@ destroy_nfsv4_state(struct nfs_server *server)
         kfree(server->mnt_path);
         server->mnt_path = NULL;
         if (server->nfs_client) {
-                nfs4_put_client(server->nfs_client);
+                nfs_put_client(server->nfs_client);
                 server->nfs_client = NULL;
         }
 }
 
-/*
- * nfs4_get_client(): returns an empty client structure
- * nfs4_put_client(): drops reference to client structure
- *
- * Since these are allocated/deallocated very rarely, we don't
- * bother putting them in a slab cache...
- */
-static struct nfs_client *
-nfs4_alloc_client(struct in_addr *addr)
-{
-        struct nfs_client *clp;
-
-        if (nfs_callback_up() < 0)
-                return NULL;
-        if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL) {
-                nfs_callback_down();
-                return NULL;
-        }
-        memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
-        init_rwsem(&clp->cl_sem);
-        INIT_LIST_HEAD(&clp->cl_delegations);
-        INIT_LIST_HEAD(&clp->cl_state_owners);
-        INIT_LIST_HEAD(&clp->cl_unused);
-        spin_lock_init(&clp->cl_lock);
-        atomic_set(&clp->cl_count, 1);
-        INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
-        INIT_LIST_HEAD(&clp->cl_superblocks);
-        rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
-        clp->cl_rpcclient = ERR_PTR(-EINVAL);
-        clp->cl_boot_time = CURRENT_TIME;
-        clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
-        return clp;
-}
-
-static void
-nfs4_free_client(struct nfs_client *clp)
-{
-        struct nfs4_state_owner *sp;
-
-        while (!list_empty(&clp->cl_unused)) {
-                sp = list_entry(clp->cl_unused.next,
-                                struct nfs4_state_owner,
-                                so_list);
-                list_del(&sp->so_list);
-                kfree(sp);
-        }
-        BUG_ON(!list_empty(&clp->cl_state_owners));
-        nfs_idmap_delete(clp);
-        if (!IS_ERR(clp->cl_rpcclient))
-                rpc_shutdown_client(clp->cl_rpcclient);
-        kfree(clp);
-        nfs_callback_down();
-}
-
-static struct nfs_client *__nfs4_find_client(struct in_addr *addr)
-{
-        struct nfs_client *clp;
-        list_for_each_entry(clp, &nfs4_clientid_list, cl_servers) {
-                if (memcmp(&clp->cl_addr, addr, sizeof(clp->cl_addr)) == 0) {
-                        atomic_inc(&clp->cl_count);
-                        return clp;
-                }
-        }
-        return NULL;
-}
-
-struct nfs_client *nfs4_find_client(struct in_addr *addr)
-{
-        struct nfs_client *clp;
-        spin_lock(&state_spinlock);
-        clp = __nfs4_find_client(addr);
-        spin_unlock(&state_spinlock);
-        return clp;
-}
-
-struct nfs_client *
-nfs4_get_client(struct in_addr *addr)
-{
-        struct nfs_client *clp, *new = NULL;
-
-        spin_lock(&state_spinlock);
-        for (;;) {
-                clp = __nfs4_find_client(addr);
-                if (clp != NULL)
-                        break;
-                clp = new;
-                if (clp != NULL) {
-                        list_add(&clp->cl_servers, &nfs4_clientid_list);
-                        new = NULL;
-                        break;
-                }
-                spin_unlock(&state_spinlock);
-                new = nfs4_alloc_client(addr);
-                spin_lock(&state_spinlock);
-                if (new == NULL)
-                        break;
-        }
-        spin_unlock(&state_spinlock);
-        if (new)
-                nfs4_free_client(new);
-        return clp;
-}
-
-void
-nfs4_put_client(struct nfs_client *clp)
-{
-        if (!atomic_dec_and_lock(&clp->cl_count, &state_spinlock))
-                return;
-        list_del(&clp->cl_servers);
-        spin_unlock(&state_spinlock);
-        BUG_ON(!list_empty(&clp->cl_superblocks));
-        rpc_wake_up(&clp->cl_rpcwaitq);
-        nfs4_kill_renewd(clp);
-        nfs4_free_client(clp);
-}
-
 static int nfs4_init_client(struct nfs_client *clp, struct rpc_cred *cred)
 {
         int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK,
@@ -771,11 +655,11 @@ static void nfs4_recover_state(struct nfs_client *clp)
         __module_get(THIS_MODULE);
         atomic_inc(&clp->cl_count);
         task = kthread_run(reclaimer, clp, "%u.%u.%u.%u-reclaim",
-                        NIPQUAD(clp->cl_addr));
+                        NIPQUAD(clp->cl_addr.sin_addr));
         if (!IS_ERR(task))
                 return;
         nfs4_clear_recover_bit(clp);
-        nfs4_put_client(clp);
+        nfs_put_client(clp);
         module_put(THIS_MODULE);
 }
 
@@ -970,12 +854,12 @@ out:
         if (status == -NFS4ERR_CB_PATH_DOWN)
                 nfs_handle_cb_pathdown(clp);
         nfs4_clear_recover_bit(clp);
-        nfs4_put_client(clp);
+        nfs_put_client(clp);
         module_put_and_exit(0);
         return 0;
 out_error:
         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
-                                NIPQUAD(clp->cl_addr.s_addr), -status);
+                                NIPQUAD(clp->cl_addr.sin_addr), -status);
         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
         goto out;
 }
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 3ee85c4e65d8..f97d7d9c5c32 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1104,47 +1104,46 @@ static struct rpc_clnt *nfs4_create_client(struct nfs_server *server,
         struct rpc_clnt *clnt = NULL;
         int err = -EIO;
 
-        clp = nfs4_get_client(&server->addr.sin_addr);
+        clp = nfs_get_client(server->hostname, &server->addr, 4);
         if (!clp) {
                 dprintk("%s: failed to create NFS4 client.\n", __FUNCTION__);
                 return ERR_PTR(err);
         }
 
         /* Now create transport and client */
-        down_write(&clp->cl_sem);
-        if (IS_ERR(clp->cl_rpcclient)) {
+        if (clp->cl_cons_state == NFS_CS_INITING) {
                 xprt = xprt_create_proto(proto, &server->addr, timeparms);
                 if (IS_ERR(xprt)) {
-                        up_write(&clp->cl_sem);
                         err = PTR_ERR(xprt);
                         dprintk("%s: cannot create RPC transport. Error = %d\n",
                                         __FUNCTION__, err);
-                        goto out_fail;
+                        goto client_init_error;
                 }
                 /* Bind to a reserved port! */
                 xprt->resvport = 1;
                 clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
                                 server->rpc_ops->version, flavor);
                 if (IS_ERR(clnt)) {
-                        up_write(&clp->cl_sem);
                         err = PTR_ERR(clnt);
                         dprintk("%s: cannot create RPC client. Error = %d\n",
                                         __FUNCTION__, err);
-                        goto out_fail;
+                        goto client_init_error;
                 }
                 clnt->cl_intr     = 1;
                 clnt->cl_softrtry = 1;
                 clp->cl_rpcclient = clnt;
                 memcpy(clp->cl_ipaddr, server->ip_addr, sizeof(clp->cl_ipaddr));
-                if (nfs_idmap_new(clp) < 0)
-                        goto out_fail;
+                err = nfs_idmap_new(clp);
+                if (err < 0) {
+                        dprintk("%s: failed to create idmapper.\n",
+                                __FUNCTION__);
+                        goto client_init_error;
+                }
+                __set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
+                nfs_mark_client_ready(clp, 0);
         }
-        list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
+
         clnt = rpc_clone_client(clp->cl_rpcclient);
-        if (!IS_ERR(clnt))
-                server->nfs_client = clp;
-        up_write(&clp->cl_sem);
-        clp = NULL;
 
         if (IS_ERR(clnt)) {
                 dprintk("%s: cannot create RPC client. Error = %d\n",
@@ -1152,11 +1151,6 @@ static struct rpc_clnt *nfs4_create_client(struct nfs_server *server,
                 return clnt;
         }
 
-        if (server->nfs_client->cl_idmap == NULL) {
-                dprintk("%s: failed to create idmapper.\n", __FUNCTION__);
-                return ERR_PTR(-ENOMEM);
-        }
-
         if (clnt->cl_auth->au_flavor != flavor) {
                 struct rpc_auth *auth;
 
@@ -1166,11 +1160,16 @@ static struct rpc_clnt *nfs4_create_client(struct nfs_server *server,
                         return (struct rpc_clnt *)auth;
                 }
         }
+
+        server->nfs_client = clp;
+        down_write(&clp->cl_sem);
+        list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
+        up_write(&clp->cl_sem);
         return clnt;
 
- out_fail:
-        if (clp)
-                nfs4_put_client(clp);
+client_init_error:
+        nfs_mark_client_ready(clp, err);
+        nfs_put_client(clp);
         return ERR_PTR(err);
 }
 
@@ -1329,14 +1328,6 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
                 goto out_free;
         }
 
-        /* Fire up rpciod if not yet running */
-        error = rpciod_up();
-        if (error < 0) {
-                dprintk("%s: couldn't start rpciod! Error = %d\n",
-                                __FUNCTION__, error);
-                goto out_free;
-        }
-
         s = sget(fs_type, nfs4_compare_super, nfs_set_super, server);
         if (IS_ERR(s)) {
                 error = PTR_ERR(s);
@@ -1383,8 +1374,6 @@ static void nfs4_kill_super(struct super_block *sb)
 
         destroy_nfsv4_state(server);
 
-        rpciod_down();
-
         nfs_free_iostats(server->io_stats);
         kfree(server->hostname);
         kfree(server);
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index a36e01cd6321..70e1dc9162e2 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -586,6 +586,7 @@ extern void * nfs_root_data(void);
 #define NFSDBG_FILE             0x0040
 #define NFSDBG_ROOT             0x0080
 #define NFSDBG_CALLBACK         0x0100
+#define NFSDBG_CLIENT           0x0200
 #define NFSDBG_ALL              0xFFFF
 
 #ifdef __KERNEL__
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index fc20d6b934fb..a727657e0ad3 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -7,6 +7,66 @@
 struct nfs_iostats;
 
 /*
+ * The nfs_client identifies our client state to the server.
+ */
+struct nfs_client {
+        atomic_t                cl_count;
+        int                     cl_cons_state;  /* current construction state (-ve: init error) */
+#define NFS_CS_READY            0               /* ready to be used */
+#define NFS_CS_INITING          1               /* busy initialising */
+        int                     cl_nfsversion;  /* NFS protocol version */
+        unsigned long           cl_res_state;   /* NFS resources state */
+#define NFS_CS_RPCIOD           0               /* - rpciod started */
+#define NFS_CS_CALLBACK         1               /* - callback started */
+#define NFS_CS_IDMAP            2               /* - idmap started */
+        struct sockaddr_in      cl_addr;        /* server identifier */
+        char *                  cl_hostname;    /* hostname of server */
+        struct list_head        cl_share_link;  /* link in global client list */
+        struct list_head        cl_superblocks; /* List of nfs_server structs */
+
+        struct rpc_clnt *       cl_rpcclient;
+
+#ifdef CONFIG_NFS_V4
+        u64                     cl_clientid;    /* constant */
+        nfs4_verifier           cl_confirm;
+        unsigned long           cl_state;
+
+        u32                     cl_lockowner_id;
+
+        /*
+         * The following rwsem ensures exclusive access to the server
+         * while we recover the state following a lease expiration.
+         */
+        struct rw_semaphore     cl_sem;
+
+        struct list_head        cl_delegations;
+        struct list_head        cl_state_owners;
+        struct list_head        cl_unused;
+        int                     cl_nunused;
+        spinlock_t              cl_lock;
+
+        unsigned long           cl_lease_time;
+        unsigned long           cl_last_renewal;
+        struct work_struct      cl_renewd;
+        struct work_struct      cl_recoverd;
+
+        struct rpc_wait_queue   cl_rpcwaitq;
+
+        /* used for the setclientid verifier */
+        struct timespec         cl_boot_time;
+
+        /* idmapper */
+        struct idmap *          cl_idmap;
+
+        /* Our own IP address, as a null-terminated string.
+         * This is used to generate the clientid, and the callback address.
+         */
+        char                    cl_ipaddr[16];
+        unsigned char           cl_id_uniquifier;
+#endif
+};
+
+/*
  * NFS client parameters stored in the superblock.
  */
 struct nfs_server {