6 files changed, 49 insertions, 21 deletions

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 0e0865e38065..1bb297243624 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -8,6 +8,7 @@
 #include <linux/nfs4.h>
 #include <linux/nfs_fs.h>
 #include <linux/slab.h>
+#include <linux/rcupdate.h>
 #include "nfs4_fs.h"
 #include "callback.h"
 #include "delegation.h"
@@ -33,7 +34,7 @@ __be32 nfs4_callback_getattr(struct cb_getattrargs *args,
         res->bitmap[0] = res->bitmap[1] = 0;
         res->status = htonl(NFS4ERR_BADHANDLE);
 
-        dprintk("NFS: GETATTR callback request from %s\n",
+        dprintk_rcu("NFS: GETATTR callback request from %s\n",
                 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 
         inode = nfs_delegation_find_inode(cps->clp, &args->fh);
@@ -73,7 +74,7 @@ __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
         if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
                 goto out;
 
-        dprintk("NFS: RECALL callback request from %s\n",
+        dprintk_rcu("NFS: RECALL callback request from %s\n",
                 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 
         res = htonl(NFS4ERR_BADHANDLE);
@@ -533,7 +534,7 @@ __be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy,
         if (!cps->clp) /* set in cb_sequence */
                 goto out;
 
-        dprintk("NFS: RECALL_ANY callback request from %s\n",
+        dprintk_rcu("NFS: RECALL_ANY callback request from %s\n",
                 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 
         status = cpu_to_be32(NFS4ERR_INVAL);
@@ -568,7 +569,7 @@ __be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy,
         if (!cps->clp) /* set in cb_sequence */
                 goto out;
 
-        dprintk("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
+        dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
                 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
                 args->crsa_target_max_slots);
 
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 1506adf4d4ed..d038dc5916e5 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1284,16 +1284,18 @@ static int nfs4_init_callback(struct nfs_client *clp)
         int error;
 
         if (clp->rpc_ops->version == 4) {
+                struct rpc_xprt *xprt;
+
+                xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
+
                 if (nfs4_has_session(clp)) {
-                        error = xprt_setup_backchannel(
-                                                clp->cl_rpcclient->cl_xprt,
+                        error = xprt_setup_backchannel(xprt,
                                                 NFS41_BC_MIN_CALLBACKS);
                         if (error < 0)
                                 return error;
                 }
 
-                error = nfs_callback_up(clp->cl_mvops->minor_version,
-                                        clp->cl_rpcclient->cl_xprt);
+                error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
                 if (error < 0) {
                         dprintk("%s: failed to start callback. Error = %d\n",
                                 __func__, error);
@@ -1678,7 +1680,7 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
                                 data->addrlen,
                                 parent_client->cl_ipaddr,
                                 data->authflavor,
-                                parent_server->client->cl_xprt->prot,
+                                rpc_protocol(parent_server->client),
                                 parent_server->client->cl_timeout,
                                 parent_client->cl_mvops->minor_version,
                                 parent_client->net);
@@ -1905,12 +1907,14 @@ static int nfs_server_list_show(struct seq_file *m, void *v)
         if (clp->cl_cons_state != NFS_CS_READY)
                 return 0;
 
+        rcu_read_lock();
         seq_printf(m, "v%u %s %s %3d %s\n",
                    clp->rpc_ops->version,
                    rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
                    rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
                    atomic_read(&clp->cl_count),
                    clp->cl_hostname);
+        rcu_read_unlock();
 
         return 0;
 }
@@ -1993,6 +1997,7 @@ static int nfs_volume_list_show(struct seq_file *m, void *v)
                  (unsigned long long) server->fsid.major,
                  (unsigned long long) server->fsid.minor);
 
+        rcu_read_lock();
         seq_printf(m, "v%u %s %s %-7s %-17s %s\n",
                    clp->rpc_ops->version,
                    rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
@@ -2000,6 +2005,7 @@ static int nfs_volume_list_show(struct seq_file *m, void *v)
                    dev,
                    fsid,
                    nfs_server_fscache_state(server));
+        rcu_read_unlock();
 
         return 0;
 }
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 667ea7406fd3..9c8eca315f43 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -96,8 +96,8 @@ static int nfs4_validate_fspath(struct dentry *dentry,
 static size_t nfs_parse_server_name(char *string, size_t len,
                 struct sockaddr *sa, size_t salen, struct nfs_server *server)
 {
+        struct net *net = rpc_net_ns(server->client);
         ssize_t ret;
-        struct net *net = server->client->cl_xprt->xprt_net;
 
         ret = rpc_pton(net, string, len, sa, salen);
         if (ret == 0) {
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 6c8e170e2e6b..671510cc14c0 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3833,6 +3833,7 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program,
         *p = htonl((u32)clp->cl_boot_time.tv_nsec);
 
         for(;;) {
+                rcu_read_lock();
                 setclientid.sc_name_len = scnprintf(setclientid.sc_name,
                                 sizeof(setclientid.sc_name), "%s/%s %s %s %u",
                                 clp->cl_ipaddr,
@@ -3849,6 +3850,7 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program,
                 setclientid.sc_uaddr_len = scnprintf(setclientid.sc_uaddr,
                                 sizeof(setclientid.sc_uaddr), "%s.%u.%u",
                                 clp->cl_ipaddr, port >> 8, port & 255);
+                rcu_read_unlock();
 
                 status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
                 if (status != -NFS4ERR_CLID_INUSE)
@@ -5244,11 +5246,16 @@ struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
 
 void nfs4_destroy_session(struct nfs4_session *session)
 {
+        struct rpc_xprt *xprt;
+
         nfs4_proc_destroy_session(session);
+
+        rcu_read_lock();
+        xprt = rcu_dereference(session->clp->cl_rpcclient->cl_xprt);
+        rcu_read_unlock();
         dprintk("%s Destroy backchannel for xprt %p\n",
-                __func__, session->clp->cl_rpcclient->cl_xprt);
-        xprt_destroy_backchannel(session->clp->cl_rpcclient->cl_xprt,
-                                NFS41_BC_MIN_CALLBACKS);
+                __func__, xprt);
+        xprt_destroy_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
         nfs4_destroy_slot_tables(session);
         kfree(session);
 }
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index c1111a37dc14..bae959e294cd 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1037,19 +1037,28 @@ static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
 void nfs4_schedule_state_manager(struct nfs_client *clp)
 {
         struct task_struct *task;
+        char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
 
         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
                 return;
         __module_get(THIS_MODULE);
         atomic_inc(&clp->cl_count);
-        task = kthread_run(nfs4_run_state_manager, clp, "%s-manager",
-                                rpc_peeraddr2str(clp->cl_rpcclient,
-                                                        RPC_DISPLAY_ADDR));
-        if (!IS_ERR(task))
-                return;
-        nfs4_clear_state_manager_bit(clp);
-        nfs_put_client(clp);
-        module_put(THIS_MODULE);
+
+        /* The rcu_read_lock() is not strictly necessary, as the state
+         * manager is the only thread that ever changes the rpc_xprt
+         * after it's initialized.  At this point, we're single threaded. */
+        rcu_read_lock();
+        snprintf(buf, sizeof(buf), "%s-manager",
+                        rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
+        rcu_read_unlock();
+        task = kthread_run(nfs4_run_state_manager, clp, buf);
+        if (IS_ERR(task)) {
+                printk(KERN_ERR "%s: kthread_run: %ld\n",
+                        __func__, PTR_ERR(task));
+                nfs4_clear_state_manager_bit(clp);
+                nfs_put_client(clp);
+                module_put(THIS_MODULE);
+        }
 }
 
 /*
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index f4ccdae6a0cf..7002be11d99f 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -53,6 +53,7 @@
 #include <linux/magic.h>
 #include <linux/parser.h>
 #include <linux/nsproxy.h>
+#include <linux/rcupdate.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -701,8 +702,10 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
                 else
                         seq_puts(m, nfs_infop->nostr);
         }
+        rcu_read_lock();
         seq_printf(m, ",proto=%s",
                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
+        rcu_read_unlock();
         if (version == 4) {
                 if (nfss->port != NFS_PORT)
                         seq_printf(m, ",port=%u", nfss->port);
@@ -751,9 +754,11 @@ static int nfs_show_options(struct seq_file *m, struct dentry *root)
 
         nfs_show_mount_options(m, nfss, 0);
 
+        rcu_read_lock();
         seq_printf(m, ",addr=%s",
                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
                                                         RPC_DISPLAY_ADDR));
+        rcu_read_unlock();
 
         return 0;
 }