NFS: make nfs_client_list per net ns

This patch splits global list of NFS clients into per-net-ns array of lists.
This looks more strict and clearer.
BTW, this patch also makes "/proc/fs/nfsfs/servers" entry content depends on
/proc mount owner pid namespace. See below for details.

NOTE: few words about how was /proc/fs/nfsfs/ entries content show per network
namespace done. This is a little bit tricky and not the best is could be. But
it's cheap (proper fix for /proc conteinerization is a hard nut to crack).
The idea is simple: take proper network namespace from pid namespace
child reaper nsproxy of /proc/ mount creator.
This actually means, that if there are 2 containers with different net
namespace sharing pid namespace, then read of /proc/fs/nfsfs/ entries will
always return content, taken from net namespace of pid namespace creator task
(and thus second namespace set wil be unvisible).

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 98af1cb..058eb9b 100644 (file)
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -39,6 +39,8 @@
 #include <net/ipv6.h>
 #include <linux/nfs_xdr.h>
 #include <linux/sunrpc/bc_xprt.h>
+#include <linux/nsproxy.h>
+#include <linux/pid_namespace.h>
 
 #include <asm/system.h>
 
@@ -49,11 +51,11 @@
 #include "internal.h"
 #include "fscache.h"
 #include "pnfs.h"
+#include "netns.h"
 
 #define NFSDBG_FACILITY                NFSDBG_CLIENT
 
 DEFINE_SPINLOCK(nfs_client_lock);
-LIST_HEAD(nfs_client_list);
 static LIST_HEAD(nfs_volume_list);
 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
 #ifdef CONFIG_NFS_V4
@@ -464,8 +466,9 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat
 {
        struct nfs_client *clp;
        const struct sockaddr *sap = data->addr;
+       struct nfs_net *nn = net_generic(data->net, nfs_net_id);
 
-       list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
+       list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
                const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
                /* Don't match clients that failed to initialise properly */
                if (clp->cl_cons_state < 0)
@@ -483,9 +486,6 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat
                /* Match the full socket address */
                if (!nfs_sockaddr_cmp(sap, clap))
                        continue;
-               /* Match network namespace */
-               if (clp->net != data->net)
-                       continue;
 
                atomic_inc(&clp->cl_count);
                return clp;
@@ -506,6 +506,7 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
 {
        struct nfs_client *clp, *new = NULL;
        int error;
+       struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
 
        dprintk("--> nfs_get_client(%s,v%u)\n",
                cl_init->hostname ?: "", cl_init->rpc_ops->version);
@@ -531,7 +532,7 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
        /* install a new client and return with it unready */
 install_client:
        clp = new;
-       list_add(&clp->cl_share_link, &nfs_client_list);
+       list_add(&clp->cl_share_link, &nn->nfs_client_list);
        spin_unlock(&nfs_client_lock);
 
        error = cl_init->rpc_ops->init_client(clp, timeparms, ip_addr,
@@ -1227,9 +1228,10 @@ nfs4_find_client_sessionid(const struct sockaddr *addr,
                           struct nfs4_sessionid *sid)
 {
        struct nfs_client *clp;
+       struct nfs_net *nn = net_generic(&init_net, nfs_net_id);
 
        spin_lock(&nfs_client_lock);
-       list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
+       list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
                if (nfs4_cb_match_client(addr, clp, 1) == false)
                        continue;
 
@@ -1757,6 +1759,13 @@ out_free_server:
        return ERR_PTR(error);
 }
 
+void nfs_clients_init(struct net *net)
+{
+       struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+       INIT_LIST_HEAD(&nn->nfs_client_list);
+}
+
 #ifdef CONFIG_PROC_FS
 static struct proc_dir_entry *proc_fs_nfs;
 
@@ -1810,13 +1819,15 @@ static int nfs_server_list_open(struct inode *inode, struct file *file)
 {
        struct seq_file *m;
        int ret;
+       struct pid_namespace *pid_ns = file->f_dentry->d_sb->s_fs_info;
+       struct net *net = pid_ns->child_reaper->nsproxy->net_ns;
 
        ret = seq_open(file, &nfs_server_list_ops);
        if (ret < 0)
                return ret;
 
        m = file->private_data;
-       m->private = PDE(inode)->data;
+       m->private = net;
 
        return 0;
 }
@@ -1826,9 +1837,11 @@ static int nfs_server_list_open(struct inode *inode, struct file *file)
  */
 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
 {
+       struct nfs_net *nn = net_generic(m->private, nfs_net_id);
+
        /* lock the list against modification */
        spin_lock(&nfs_client_lock);
-       return seq_list_start_head(&nfs_client_list, *_pos);
+       return seq_list_start_head(&nn->nfs_client_list, *_pos);
 }
 
 /*
@@ -1836,7 +1849,9 @@ static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
  */
 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
 {
-       return seq_list_next(v, &nfs_client_list, pos);
+       struct nfs_net *nn = net_generic(p->private, nfs_net_id);
+
+       return seq_list_next(v, &nn->nfs_client_list, pos);
 }
 
 /*
@@ -1853,9 +1868,10 @@ static void nfs_server_list_stop(struct seq_file *p, void *v)
 static int nfs_server_list_show(struct seq_file *m, void *v)
 {
        struct nfs_client *clp;
+       struct nfs_net *nn = net_generic(m->private, nfs_net_id);
 
        /* display header on line 1 */
-       if (v == &nfs_client_list) {
+       if (v == &nn->nfs_client_list) {
                seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
                return 0;
        }

diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 83f7d42..2f78f0c 100644 (file)
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -532,13 +532,12 @@ static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
                            void *ptr)
 {
        struct super_block *sb = ptr;
+       struct nfs_net *nn = net_generic(sb->s_fs_info, nfs_net_id);
        struct nfs_client *clp;
        int error = 0;
 
        spin_lock(&nfs_client_lock);
-       list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
-               if (clp->net != sb->s_fs_info)
-                       continue;
+       list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
                if (clp->rpc_ops != &nfs_v4_clientops)
                        continue;
                error = __rpc_pipefs_event(clp, event, sb);

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 028464b..0365b84 100644 (file)
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1558,6 +1558,7 @@ EXPORT_SYMBOL_GPL(nfs_net_id);
 
 static int nfs_net_init(struct net *net)
 {
+       nfs_clients_init(net);
        return nfs_dns_resolver_cache_init(net);
 }
 

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index cdb121d..a9ae806 100644 (file)
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -146,6 +146,7 @@ extern void nfs_umount(const struct nfs_mount_request *info);
 
 /* client.c */
 extern const struct rpc_program nfs_program;
+extern void nfs_clients_init(struct net *net);
 
 extern void nfs_cleanup_cb_ident_idr(void);
 extern void nfs_put_client(struct nfs_client *);
@@ -183,7 +184,6 @@ static inline void nfs_fs_proc_exit(void)
 #endif
 #ifdef CONFIG_NFS_V4
 extern spinlock_t nfs_client_lock;
-extern struct list_head nfs_client_list;
 #endif
 
 /* nfs4namespace.c */

diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index 39ae4ca..feb33c3 100644 (file)
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -7,6 +7,7 @@
 struct nfs_net {
        struct cache_detail *nfs_dns_resolve;
        struct rpc_pipe *bl_device_pipe;
+       struct list_head nfs_client_list;
 };
 
 extern int nfs_net_id;