[PATCH 2/4] NFS: make nfs_volume_list per net ns
From: Stanislav Kinsbursky
Date: Mon Jan 23 2012 - 12:26:19 EST
This patch splits global list of NFS servers into per-net-ns array of lists.
This looks more strict and clearer.
BTW, this patch also makes "/proc/fs/nfsfs/volumes" 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@xxxxxxxxxxxxx>
---
fs/nfs/client.c | 20 ++++++++++++++------
fs/nfs/netns.h | 1 +
2 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 058eb9b..d58e838 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -56,7 +56,6 @@
#define NFSDBG_FACILITY NFSDBG_CLIENT
DEFINE_SPINLOCK(nfs_client_lock);
-static LIST_HEAD(nfs_volume_list);
static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
#ifdef CONFIG_NFS_V4
static DEFINE_IDR(cb_ident_idr); /* Protected by nfs_client_lock */
@@ -1036,10 +1035,11 @@ static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_serve
static void nfs_server_insert_lists(struct nfs_server *server)
{
struct nfs_client *clp = server->nfs_client;
+ struct nfs_net *nn = net_generic(clp->net, nfs_net_id);
spin_lock(&nfs_client_lock);
list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
- list_add_tail(&server->master_link, &nfs_volume_list);
+ list_add_tail(&server->master_link, &nn->nfs_volume_list);
clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
spin_unlock(&nfs_client_lock);
@@ -1764,6 +1764,7 @@ void nfs_clients_init(struct net *net)
struct nfs_net *nn = net_generic(net, nfs_net_id);
INIT_LIST_HEAD(&nn->nfs_client_list);
+ INIT_LIST_HEAD(&nn->nfs_volume_list);
}
#ifdef CONFIG_PROC_FS
@@ -1900,13 +1901,15 @@ static int nfs_volume_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_volume_list_ops);
if (ret < 0)
return ret;
m = file->private_data;
- m->private = PDE(inode)->data;
+ m->private = net;
return 0;
}
@@ -1916,9 +1919,11 @@ static int nfs_volume_list_open(struct inode *inode, struct file *file)
*/
static void *nfs_volume_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_volume_list, *_pos);
+ return seq_list_start_head(&nn->nfs_volume_list, *_pos);
}
/*
@@ -1926,7 +1931,9 @@ static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
*/
static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
{
- return seq_list_next(v, &nfs_volume_list, pos);
+ struct nfs_net *nn = net_generic(p->private, nfs_net_id);
+
+ return seq_list_next(v, &nn->nfs_volume_list, pos);
}
/*
@@ -1945,9 +1952,10 @@ static int nfs_volume_list_show(struct seq_file *m, void *v)
struct nfs_server *server;
struct nfs_client *clp;
char dev[8], fsid[17];
+ struct nfs_net *nn = net_generic(m->private, nfs_net_id);
/* display header on line 1 */
- if (v == &nfs_volume_list) {
+ if (v == &nn->nfs_volume_list) {
seq_puts(m, "NV SERVER PORT DEV FSID FSC\n");
return 0;
}
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index feb33c3..0fbd4e0 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -8,6 +8,7 @@ struct nfs_net {
struct cache_detail *nfs_dns_resolve;
struct rpc_pipe *bl_device_pipe;
struct list_head nfs_client_list;
+ struct list_head nfs_volume_list;
};
extern int nfs_net_id;
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