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>

4 files changed, 45 insertions, 24 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");
diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
index 49c670b18a9e..0966b39bbcfb 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -37,6 +37,7 @@
 #include <linux/sunrpc/rpc_pipe_fs.h>
 
 #include "../pnfs.h"
+#include "../netns.h"
 
 #define PAGE_CACHE_SECTORS (PAGE_CACHE_SIZE >> SECTOR_SHIFT)
 #define PAGE_CACHE_SECTOR_SHIFT (PAGE_CACHE_SHIFT - SECTOR_SHIFT)
@@ -50,6 +51,7 @@ struct pnfs_block_dev {
         struct list_head                bm_node;
         struct nfs4_deviceid            bm_mdevid;    /* associated devid */
         struct block_device             *bm_mdev;     /* meta device itself */
+        struct net                      *net;
 };
 
 enum exstate4 {
@@ -161,7 +163,6 @@ struct bl_msg_hdr {
         u16 totallen; /* length of entire message, including hdr itself */
 };
 
-extern struct rpc_pipe *bl_device_pipe;
 extern wait_queue_head_t bl_wq;
 
 #define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */
diff --git a/fs/nfs/blocklayout/blocklayoutdev.c b/fs/nfs/blocklayout/blocklayoutdev.c
index 949b62478799..94ed978860c0 100644
--- a/fs/nfs/blocklayout/blocklayoutdev.c
+++ b/fs/nfs/blocklayout/blocklayoutdev.c
@@ -120,6 +120,8 @@ nfs4_blk_decode_device(struct nfs_server *server,
         DECLARE_WAITQUEUE(wq, current);
         struct bl_dev_msg *reply = &bl_mount_reply;
         int offset, len, i, rc;
+        struct net *net = server->nfs_client->net;
+        struct nfs_net *nn = net_generic(net, nfs_net_id);
 
         dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);
         dprintk("%s: deviceid: %s, mincount: %d\n", __func__, dev->dev_id.data,
@@ -146,7 +148,7 @@ nfs4_blk_decode_device(struct nfs_server *server,
 
         dprintk("%s CALLING USERSPACE DAEMON\n", __func__);
         add_wait_queue(&bl_wq, &wq);
-        rc = rpc_queue_upcall(bl_device_pipe, &msg);
+        rc = rpc_queue_upcall(nn->bl_device_pipe, &msg);
         if (rc < 0) {
                 remove_wait_queue(&bl_wq, &wq);
                 rv = ERR_PTR(rc);
@@ -181,6 +183,7 @@ nfs4_blk_decode_device(struct nfs_server *server,
 
         rv->bm_mdev = bd;
         memcpy(&rv->bm_mdevid, &dev->dev_id, sizeof(struct nfs4_deviceid));
+        rv->net = net;
         dprintk("%s Created device %s with bd_block_size %u\n",
                 __func__,
                 bd->bd_disk->disk_name,
diff --git a/fs/nfs/blocklayout/blocklayoutdm.c b/fs/nfs/blocklayout/blocklayoutdm.c
index 631f254d12ab..970490f556de 100644
--- a/fs/nfs/blocklayout/blocklayoutdm.c
+++ b/fs/nfs/blocklayout/blocklayoutdm.c
@@ -38,7 +38,7 @@
 
 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
 
-static void dev_remove(dev_t dev)
+static void dev_remove(struct net *net, dev_t dev)
 {
         struct rpc_pipe_msg msg;
         struct bl_dev_msg bl_umount_request;
@@ -48,6 +48,7 @@ static void dev_remove(dev_t dev)
         };
         uint8_t *dataptr;
         DECLARE_WAITQUEUE(wq, current);
+        struct nfs_net *nn = net_generic(net, nfs_net_id);
 
         dprintk("Entering %s\n", __func__);
 
@@ -66,7 +67,7 @@ static void dev_remove(dev_t dev)
         msg.len = sizeof(bl_msg) + bl_msg.totallen;
 
         add_wait_queue(&bl_wq, &wq);
-        if (rpc_queue_upcall(bl_device_pipe, &msg) < 0) {
+        if (rpc_queue_upcall(nn->bl_device_pipe, &msg) < 0) {
                 remove_wait_queue(&bl_wq, &wq);
                 goto out;
         }
@@ -93,7 +94,7 @@ static void nfs4_blk_metadev_release(struct pnfs_block_dev *bdev)
                 printk(KERN_ERR "%s nfs4_blkdev_put returns %d\n",
                                 __func__, rv);
 
-        dev_remove(bdev->bm_mdev->bd_dev);
+        dev_remove(bdev->net, bdev->bm_mdev->bd_dev);
 }
 
 void bl_free_block_dev(struct pnfs_block_dev *bdev)