afs: Implement network namespacing

Implement network namespacing within AFS, but don't yet let mounts occur
outside the init namespace.  An additional patch will be required propagate
the network namespace across automounts.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 27 insertions, 6 deletions

diff --git a/fs/afs/main.c b/fs/afs/main.c
index d7560168b3bf..7d2c1354e2ca 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -15,6 +15,7 @@
 #include <linux/completion.h>
 #include <linux/sched.h>
 #include <linux/random.h>
+#include <linux/proc_fs.h>
 #define CREATE_TRACE_POINTS
 #include "internal.h"
 
@@ -32,7 +33,7 @@ module_param(rootcell, charp, 0);
 MODULE_PARM_DESC(rootcell, "root AFS cell name and VL server IP addr list");
 
 struct workqueue_struct *afs_wq;
-struct afs_net __afs_net;
+static struct proc_dir_entry *afs_proc_symlink;
 
 #if defined(CONFIG_ALPHA)
 const char afs_init_sysname[] = "alpha_linux26";
@@ -67,11 +68,13 @@ const char afs_init_sysname[] = "unknown_linux26";
 /*
  * Initialise an AFS network namespace record.
  */
-static int __net_init afs_net_init(struct afs_net *net)
+static int __net_init afs_net_init(struct net *net_ns)
 {
 	struct afs_sysnames *sysnames;
+	struct afs_net *net = afs_net(net_ns);
 	int ret;
 
+	net->net = net_ns;
 	net->live = true;
 	generate_random_uuid((unsigned char *)&net->uuid);
 
@@ -142,8 +145,10 @@ error_sysnames:
 /*
  * Clean up and destroy an AFS network namespace record.
  */
-static void __net_exit afs_net_exit(struct afs_net *net)
+static void __net_exit afs_net_exit(struct net *net_ns)
 {
+	struct afs_net *net = afs_net(net_ns);
+
 	net->live = false;
 	afs_cell_purge(net);
 	afs_purge_servers(net);
@@ -152,6 +157,13 @@ static void __net_exit afs_net_exit(struct afs_net *net)
 	afs_put_sysnames(net->sysnames);
 }
 
+static struct pernet_operations afs_net_ops = {
+	.init	= afs_net_init,
+	.exit	= afs_net_exit,
+	.id	= &afs_net_id,
+	.size	= sizeof(struct afs_net),
+};
+
 /*
  * initialise the AFS client FS module
  */
@@ -178,7 +190,7 @@ static int __init afs_init(void)
 		goto error_cache;
 #endif
 
-	ret = afs_net_init(&__afs_net);
+	ret = register_pernet_subsys(&afs_net_ops);
 	if (ret < 0)
 		goto error_net;
 
@@ -187,10 +199,18 @@ static int __init afs_init(void)
 	if (ret < 0)
 		goto error_fs;
 
+	afs_proc_symlink = proc_symlink("fs/afs", NULL, "../self/net/afs");
+	if (IS_ERR(afs_proc_symlink)) {
+		ret = PTR_ERR(afs_proc_symlink);
+		goto error_proc;
+	}
+
 	return ret;
 
+error_proc:
+	afs_fs_exit();
 error_fs:
-	afs_net_exit(&__afs_net);
+	unregister_pernet_subsys(&afs_net_ops);
 error_net:
 #ifdef CONFIG_AFS_FSCACHE
 	fscache_unregister_netfs(&afs_cache_netfs);
@@ -219,8 +239,9 @@ static void __exit afs_exit(void)
 {
 	printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 unregistering.\n");
 
+	proc_remove(afs_proc_symlink);
 	afs_fs_exit();
-	afs_net_exit(&__afs_net);
+	unregister_pernet_subsys(&afs_net_ops);
 #ifdef CONFIG_AFS_FSCACHE
 	fscache_unregister_netfs(&afs_cache_netfs);
 #endif