NFS: blocklayout pipe creation per network namespace context introduced

This patch implements blocklayout pipe creation and registration per each
existent network namespace.
This was achived by registering NFS per-net operations, responsible for
blocklayout pipe allocation/register and unregister/destruction instead of
initialization and destruction of static "bl_device_pipe" pipe (this one was
removed).
Note, than pointer to network blocklayout pipe is stored in per-net "nfs_net"
structure, because allocating of one more per-net structure for blocklayout
module looks redundant.
This patch also changes dev_remove() function prototype (and all it's callers,
where it' requied) by adding network namespace pointer parameter, which is used
to discover proper blocklayout pipe for rpc_queue_upcall() call.

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

1 files changed, 35 insertions, 19 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 80b0c4a40485..9da72b8a5542 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -46,7 +46,6 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>");
 MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
 
-struct rpc_pipe *bl_device_pipe;
 wait_queue_head_t bl_wq;
 
 static void print_page(struct page *page)
@@ -1071,6 +1070,37 @@ static void nfs4blocklayout_unregister_net(struct net *net,
         }
 }
 
+static int nfs4blocklayout_net_init(struct net *net)
+{
+        struct nfs_net *nn = net_generic(net, nfs_net_id);
+        struct dentry *dentry;
+
+        nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
+        if (IS_ERR(nn->bl_device_pipe))
+                return PTR_ERR(nn->bl_device_pipe);
+        dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
+        if (IS_ERR(dentry)) {
+                rpc_destroy_pipe_data(nn->bl_device_pipe);
+                return PTR_ERR(dentry);
+        }
+        nn->bl_device_pipe->dentry = dentry;
+        return 0;
+}
+
+static void nfs4blocklayout_net_exit(struct net *net)
+{
+        struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+        nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
+        rpc_destroy_pipe_data(nn->bl_device_pipe);
+        nn->bl_device_pipe = NULL;
+}
+
+static struct pernet_operations nfs4blocklayout_net_ops = {
+        .init = nfs4blocklayout_net_init,
+        .exit = nfs4blocklayout_net_exit,
+};
+
 static int __init nfs4blocklayout_init(void)
 {
         struct vfsmount *mnt;
@@ -1089,24 +1119,12 @@ static int __init nfs4blocklayout_init(void)
                 ret = PTR_ERR(mnt);
                 goto out_remove;
         }
-        bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
-        if (IS_ERR(bl_device_pipe)) {
-                ret = PTR_ERR(bl_device_pipe);
-                goto out_putrpc;
-        }
-        bl_device_pipe->dentry = nfs4blocklayout_register_net(&init_net,
-                                                              bl_device_pipe);
-        if (IS_ERR(bl_device_pipe->dentry)) {
-                ret = PTR_ERR(bl_device_pipe->dentry);
-                goto out_destroy_pipe;
-        }
+        ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
+        if (ret)
+                goto out_remove;
 out:
         return ret;
 
-out_destroy_pipe:
-        rpc_destroy_pipe_data(bl_device_pipe);
-out_putrpc:
-        rpc_put_mount();
 out_remove:
         pnfs_unregister_layoutdriver(&blocklayout_type);
         return ret;
@@ -1117,10 +1135,8 @@ static void __exit nfs4blocklayout_exit(void)
         dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
                __func__);
 
+        unregister_pernet_subsys(&nfs4blocklayout_net_ops);
         pnfs_unregister_layoutdriver(&blocklayout_type);
-        nfs4blocklayout_unregister_net(&init_net, bl_device_pipe);
-        rpc_destroy_pipe_data(bl_device_pipe);
-        rpc_put_mount();
 }
 
 MODULE_ALIAS("nfs-layouttype4-3");