vfs: make it possible to access the dentry hash/len as one 64-bit entry
[linux-3.10.git] / net / sunrpc / rpc_pipe.c
index 8fa7182..fd24239 100644 (file)
@@ -16,9 +16,9 @@
 #include <linux/namei.h>
 #include <linux/fsnotify.h>
 #include <linux/kernel.h>
+#include <linux/rcupdate.h>
 
 #include <asm/ioctls.h>
-#include <linux/fs.h>
 #include <linux/poll.h>
 #include <linux/wait.h>
 #include <linux/seq_file.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/workqueue.h>
 #include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/sunrpc/cache.h>
+#include <linux/nsproxy.h>
+#include <linux/notifier.h>
 
-static struct vfsmount *rpc_mount __read_mostly;
-static int rpc_mount_count;
+#include "netns.h"
+#include "sunrpc.h"
+
+#define RPCDBG_FACILITY RPCDBG_DEBUG
+
+#define NET_NAME(net)  ((net == &init_net) ? " (init_net)" : "")
 
 static struct file_system_type rpc_pipe_fs_type;
 
@@ -37,7 +44,21 @@ static struct kmem_cache *rpc_inode_cachep __read_mostly;
 
 #define RPC_UPCALL_TIMEOUT (30*HZ)
 
-static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
+static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
+
+int rpc_pipefs_notifier_register(struct notifier_block *nb)
+{
+       return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
+
+void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
+{
+       blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
+
+static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head,
                void (*destroy_msg)(struct rpc_pipe_msg *), int err)
 {
        struct rpc_pipe_msg *msg;
@@ -46,38 +67,59 @@ static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
                return;
        do {
                msg = list_entry(head->next, struct rpc_pipe_msg, list);
-               list_del(&msg->list);
+               list_del_init(&msg->list);
                msg->errno = err;
                destroy_msg(msg);
        } while (!list_empty(head));
-       wake_up(&rpci->waitq);
+       wake_up(waitq);
 }
 
 static void
 rpc_timeout_upcall_queue(struct work_struct *work)
 {
        LIST_HEAD(free_list);
-       struct rpc_inode *rpci =
-               container_of(work, struct rpc_inode, queue_timeout.work);
-       struct inode *inode = &rpci->vfs_inode;
+       struct rpc_pipe *pipe =
+               container_of(work, struct rpc_pipe, queue_timeout.work);
        void (*destroy_msg)(struct rpc_pipe_msg *);
+       struct dentry *dentry;
 
-       spin_lock(&inode->i_lock);
-       if (rpci->ops == NULL) {
-               spin_unlock(&inode->i_lock);
-               return;
+       spin_lock(&pipe->lock);
+       destroy_msg = pipe->ops->destroy_msg;
+       if (pipe->nreaders == 0) {
+               list_splice_init(&pipe->pipe, &free_list);
+               pipe->pipelen = 0;
        }
-       destroy_msg = rpci->ops->destroy_msg;
-       if (rpci->nreaders == 0) {
-               list_splice_init(&rpci->pipe, &free_list);
-               rpci->pipelen = 0;
+       dentry = dget(pipe->dentry);
+       spin_unlock(&pipe->lock);
+       if (dentry) {
+               rpc_purge_list(&RPC_I(dentry->d_inode)->waitq,
+                              &free_list, destroy_msg, -ETIMEDOUT);
+               dput(dentry);
+       }
+}
+
+ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
+                               char __user *dst, size_t buflen)
+{
+       char *data = (char *)msg->data + msg->copied;
+       size_t mlen = min(msg->len - msg->copied, buflen);
+       unsigned long left;
+
+       left = copy_to_user(dst, data, mlen);
+       if (left == mlen) {
+               msg->errno = -EFAULT;
+               return -EFAULT;
        }
-       spin_unlock(&inode->i_lock);
-       rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
+
+       mlen -= left;
+       msg->copied += mlen;
+       msg->errno = 0;
+       return mlen;
 }
+EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
 
 /**
- * rpc_queue_upcall
+ * rpc_queue_upcall - queue an upcall message to userspace
  * @inode: inode of upcall pipe on which to queue given message
  * @msg: message to queue
  *
@@ -87,30 +129,31 @@ rpc_timeout_upcall_queue(struct work_struct *work)
  * initialize the fields of @msg (other than @msg->list) appropriately.
  */
 int
-rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
+rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
 {
-       struct rpc_inode *rpci = RPC_I(inode);
        int res = -EPIPE;
+       struct dentry *dentry;
 
-       spin_lock(&inode->i_lock);
-       if (rpci->ops == NULL)
-               goto out;
-       if (rpci->nreaders) {
-               list_add_tail(&msg->list, &rpci->pipe);
-               rpci->pipelen += msg->len;
+       spin_lock(&pipe->lock);
+       if (pipe->nreaders) {
+               list_add_tail(&msg->list, &pipe->pipe);
+               pipe->pipelen += msg->len;
                res = 0;
-       } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
-               if (list_empty(&rpci->pipe))
+       } else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
+               if (list_empty(&pipe->pipe))
                        queue_delayed_work(rpciod_workqueue,
-                                       &rpci->queue_timeout,
+                                       &pipe->queue_timeout,
                                        RPC_UPCALL_TIMEOUT);
-               list_add_tail(&msg->list, &rpci->pipe);
-               rpci->pipelen += msg->len;
+               list_add_tail(&msg->list, &pipe->pipe);
+               pipe->pipelen += msg->len;
                res = 0;
        }
-out:
-       spin_unlock(&inode->i_lock);
-       wake_up(&rpci->waitq);
+       dentry = dget(pipe->dentry);
+       spin_unlock(&pipe->lock);
+       if (dentry) {
+               wake_up(&RPC_I(dentry->d_inode)->waitq);
+               dput(dentry);
+       }
        return res;
 }
 EXPORT_SYMBOL_GPL(rpc_queue_upcall);
@@ -124,29 +167,26 @@ rpc_inode_setowner(struct inode *inode, void *private)
 static void
 rpc_close_pipes(struct inode *inode)
 {
-       struct rpc_inode *rpci = RPC_I(inode);
-       const struct rpc_pipe_ops *ops;
+       struct rpc_pipe *pipe = RPC_I(inode)->pipe;
        int need_release;
+       LIST_HEAD(free_list);
 
        mutex_lock(&inode->i_mutex);
-       ops = rpci->ops;
-       if (ops != NULL) {
-               LIST_HEAD(free_list);
-               spin_lock(&inode->i_lock);
-               need_release = rpci->nreaders != 0 || rpci->nwriters != 0;
-               rpci->nreaders = 0;
-               list_splice_init(&rpci->in_upcall, &free_list);
-               list_splice_init(&rpci->pipe, &free_list);
-               rpci->pipelen = 0;
-               rpci->ops = NULL;
-               spin_unlock(&inode->i_lock);
-               rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
-               rpci->nwriters = 0;
-               if (need_release && ops->release_pipe)
-                       ops->release_pipe(inode);
-               cancel_delayed_work_sync(&rpci->queue_timeout);
-       }
+       spin_lock(&pipe->lock);
+       need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
+       pipe->nreaders = 0;
+       list_splice_init(&pipe->in_upcall, &free_list);
+       list_splice_init(&pipe->pipe, &free_list);
+       pipe->pipelen = 0;
+       pipe->dentry = NULL;
+       spin_unlock(&pipe->lock);
+       rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
+       pipe->nwriters = 0;
+       if (need_release && pipe->ops->release_pipe)
+               pipe->ops->release_pipe(inode);
+       cancel_delayed_work_sync(&pipe->queue_timeout);
        rpc_inode_setowner(inode, NULL);
+       RPC_I(inode)->pipe = NULL;
        mutex_unlock(&inode->i_mutex);
 }
 
@@ -161,31 +201,39 @@ rpc_alloc_inode(struct super_block *sb)
 }
 
 static void
-rpc_destroy_inode(struct inode *inode)
+rpc_i_callback(struct rcu_head *head)
 {
+       struct inode *inode = container_of(head, struct inode, i_rcu);
        kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 }
 
+static void
+rpc_destroy_inode(struct inode *inode)
+{
+       call_rcu(&inode->i_rcu, rpc_i_callback);
+}
+
 static int
 rpc_pipe_open(struct inode *inode, struct file *filp)
 {
-       struct rpc_inode *rpci = RPC_I(inode);
+       struct rpc_pipe *pipe;
        int first_open;
        int res = -ENXIO;
 
        mutex_lock(&inode->i_mutex);
-       if (rpci->ops == NULL)
+       pipe = RPC_I(inode)->pipe;
+       if (pipe == NULL)
                goto out;
-       first_open = rpci->nreaders == 0 && rpci->nwriters == 0;
-       if (first_open && rpci->ops->open_pipe) {
-               res = rpci->ops->open_pipe(inode);
+       first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
+       if (first_open && pipe->ops->open_pipe) {
+               res = pipe->ops->open_pipe(inode);
                if (res)
                        goto out;
        }
        if (filp->f_mode & FMODE_READ)
-               rpci->nreaders++;
+               pipe->nreaders++;
        if (filp->f_mode & FMODE_WRITE)
-               rpci->nwriters++;
+               pipe->nwriters++;
        res = 0;
 out:
        mutex_unlock(&inode->i_mutex);
@@ -195,38 +243,39 @@ out:
 static int
 rpc_pipe_release(struct inode *inode, struct file *filp)
 {
-       struct rpc_inode *rpci = RPC_I(inode);
+       struct rpc_pipe *pipe;
        struct rpc_pipe_msg *msg;
        int last_close;
 
        mutex_lock(&inode->i_mutex);
-       if (rpci->ops == NULL)
+       pipe = RPC_I(inode)->pipe;
+       if (pipe == NULL)
                goto out;
-       msg = (struct rpc_pipe_msg *)filp->private_data;
+       msg = filp->private_data;
        if (msg != NULL) {
-               spin_lock(&inode->i_lock);
+               spin_lock(&pipe->lock);
                msg->errno = -EAGAIN;
-               list_del(&msg->list);
-               spin_unlock(&inode->i_lock);
-               rpci->ops->destroy_msg(msg);
+               list_del_init(&msg->list);
+               spin_unlock(&pipe->lock);
+               pipe->ops->destroy_msg(msg);
        }
        if (filp->f_mode & FMODE_WRITE)
-               rpci->nwriters --;
+               pipe->nwriters --;
        if (filp->f_mode & FMODE_READ) {
-               rpci->nreaders --;
-               if (rpci->nreaders == 0) {
+               pipe->nreaders --;
+               if (pipe->nreaders == 0) {
                        LIST_HEAD(free_list);
-                       spin_lock(&inode->i_lock);
-                       list_splice_init(&rpci->pipe, &free_list);
-                       rpci->pipelen = 0;
-                       spin_unlock(&inode->i_lock);
-                       rpc_purge_list(rpci, &free_list,
-                                       rpci->ops->destroy_msg, -EAGAIN);
+                       spin_lock(&pipe->lock);
+                       list_splice_init(&pipe->pipe, &free_list);
+                       pipe->pipelen = 0;
+                       spin_unlock(&pipe->lock);
+                       rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
+                                       pipe->ops->destroy_msg, -EAGAIN);
                }
        }
-       last_close = rpci->nwriters == 0 && rpci->nreaders == 0;
-       if (last_close && rpci->ops->release_pipe)
-               rpci->ops->release_pipe(inode);
+       last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
+       if (last_close && pipe->ops->release_pipe)
+               pipe->ops->release_pipe(inode);
 out:
        mutex_unlock(&inode->i_mutex);
        return 0;
@@ -236,39 +285,40 @@ static ssize_t
 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 {
        struct inode *inode = filp->f_path.dentry->d_inode;
-       struct rpc_inode *rpci = RPC_I(inode);
+       struct rpc_pipe *pipe;
        struct rpc_pipe_msg *msg;
        int res = 0;
 
        mutex_lock(&inode->i_mutex);
-       if (rpci->ops == NULL) {
+       pipe = RPC_I(inode)->pipe;
+       if (pipe == NULL) {
                res = -EPIPE;
                goto out_unlock;
        }
        msg = filp->private_data;
        if (msg == NULL) {
-               spin_lock(&inode->i_lock);
-               if (!list_empty(&rpci->pipe)) {
-                       msg = list_entry(rpci->pipe.next,
+               spin_lock(&pipe->lock);
+               if (!list_empty(&pipe->pipe)) {
+                       msg = list_entry(pipe->pipe.next,
                                        struct rpc_pipe_msg,
                                        list);
-                       list_move(&msg->list, &rpci->in_upcall);
-                       rpci->pipelen -= msg->len;
+                       list_move(&msg->list, &pipe->in_upcall);
+                       pipe->pipelen -= msg->len;
                        filp->private_data = msg;
                        msg->copied = 0;
                }
-               spin_unlock(&inode->i_lock);
+               spin_unlock(&pipe->lock);
                if (msg == NULL)
                        goto out_unlock;
        }
        /* NOTE: it is up to the callback to update msg->copied */
-       res = rpci->ops->upcall(filp, msg, buf, len);
+       res = pipe->ops->upcall(filp, msg, buf, len);
        if (res < 0 || msg->len == msg->copied) {
                filp->private_data = NULL;
-               spin_lock(&inode->i_lock);
-               list_del(&msg->list);
-               spin_unlock(&inode->i_lock);
-               rpci->ops->destroy_msg(msg);
+               spin_lock(&pipe->lock);
+               list_del_init(&msg->list);
+               spin_unlock(&pipe->lock);
+               pipe->ops->destroy_msg(msg);
        }
 out_unlock:
        mutex_unlock(&inode->i_mutex);
@@ -279,13 +329,12 @@ static ssize_t
 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 {
        struct inode *inode = filp->f_path.dentry->d_inode;
-       struct rpc_inode *rpci = RPC_I(inode);
        int res;
 
        mutex_lock(&inode->i_mutex);
        res = -EPIPE;
-       if (rpci->ops != NULL)
-               res = rpci->ops->downcall(filp, buf, len);
+       if (RPC_I(inode)->pipe != NULL)
+               res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
        mutex_unlock(&inode->i_mutex);
        return res;
 }
@@ -293,37 +342,45 @@ rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *of
 static unsigned int
 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 {
-       struct rpc_inode *rpci;
-       unsigned int mask = 0;
+       struct inode *inode = filp->f_path.dentry->d_inode;
+       struct rpc_inode *rpci = RPC_I(inode);
+       unsigned int mask = POLLOUT | POLLWRNORM;
 
-       rpci = RPC_I(filp->f_path.dentry->d_inode);
        poll_wait(filp, &rpci->waitq, wait);
 
-       mask = POLLOUT | POLLWRNORM;
-       if (rpci->ops == NULL)
+       mutex_lock(&inode->i_mutex);
+       if (rpci->pipe == NULL)
                mask |= POLLERR | POLLHUP;
-       if (filp->private_data || !list_empty(&rpci->pipe))
+       else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
                mask |= POLLIN | POLLRDNORM;
+       mutex_unlock(&inode->i_mutex);
        return mask;
 }
 
-static int
-rpc_pipe_ioctl(struct inode *ino, struct file *filp,
-               unsigned int cmd, unsigned long arg)
+static long
+rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
-       struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
+       struct inode *inode = filp->f_path.dentry->d_inode;
+       struct rpc_pipe *pipe;
        int len;
 
        switch (cmd) {
        case FIONREAD:
-               if (rpci->ops == NULL)
+               mutex_lock(&inode->i_mutex);
+               pipe = RPC_I(inode)->pipe;
+               if (pipe == NULL) {
+                       mutex_unlock(&inode->i_mutex);
                        return -EPIPE;
-               len = rpci->pipelen;
+               }
+               spin_lock(&pipe->lock);
+               len = pipe->pipelen;
                if (filp->private_data) {
                        struct rpc_pipe_msg *msg;
-                       msg = (struct rpc_pipe_msg *)filp->private_data;
+                       msg = filp->private_data;
                        len += msg->len - msg->copied;
                }
+               spin_unlock(&pipe->lock);
+               mutex_unlock(&inode->i_mutex);
                return put_user(len, (int __user *)arg);
        default:
                return -EINVAL;
@@ -336,7 +393,7 @@ static const struct file_operations rpc_pipe_fops = {
        .read           = rpc_pipe_read,
        .write          = rpc_pipe_write,
        .poll           = rpc_pipe_poll,
-       .ioctl          = rpc_pipe_ioctl,
+       .unlocked_ioctl = rpc_pipe_ioctl,
        .open           = rpc_pipe_open,
        .release        = rpc_pipe_release,
 };
@@ -346,33 +403,38 @@ rpc_show_info(struct seq_file *m, void *v)
 {
        struct rpc_clnt *clnt = m->private;
 
-       seq_printf(m, "RPC server: %s\n", clnt->cl_server);
+       rcu_read_lock();
+       seq_printf(m, "RPC server: %s\n",
+                       rcu_dereference(clnt->cl_xprt)->servername);
        seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
                        clnt->cl_prog, clnt->cl_vers);
        seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
        seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
        seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
+       rcu_read_unlock();
        return 0;
 }
 
 static int
 rpc_info_open(struct inode *inode, struct file *file)
 {
-       struct rpc_clnt *clnt;
+       struct rpc_clnt *clnt = NULL;
        int ret = single_open(file, rpc_show_info, NULL);
 
        if (!ret) {
                struct seq_file *m = file->private_data;
-               mutex_lock(&inode->i_mutex);
-               clnt = RPC_I(inode)->private;
-               if (clnt) {
-                       kref_get(&clnt->cl_kref);
+
+               spin_lock(&file->f_path.dentry->d_lock);
+               if (!d_unhashed(file->f_path.dentry))
+                       clnt = RPC_I(inode)->private;
+               if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
+                       spin_unlock(&file->f_path.dentry->d_lock);
                        m->private = clnt;
                } else {
+                       spin_unlock(&file->f_path.dentry->d_lock);
                        single_release(inode, file);
                        ret = -EINVAL;
                }
-               mutex_unlock(&inode->i_mutex);
        }
        return ret;
 }
@@ -398,349 +460,344 @@ static const struct file_operations rpc_info_operations = {
 
 
 /*
- * We have a single directory with 1 node in it.
- */
-enum {
-       RPCAUTH_Root = 1,
-       RPCAUTH_lockd,
-       RPCAUTH_mount,
-       RPCAUTH_nfs,
-       RPCAUTH_portmap,
-       RPCAUTH_statd,
-       RPCAUTH_nfsd4_cb,
-       RPCAUTH_RootEOF
-};
-
-/*
  * Description of fs contents.
  */
 struct rpc_filelist {
-       char *name;
+       const char *name;
        const struct file_operations *i_fop;
        umode_t mode;
 };
 
-static struct rpc_filelist files[] = {
-       [RPCAUTH_lockd] = {
-               .name = "lockd",
-               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
-       },
-       [RPCAUTH_mount] = {
-               .name = "mount",
-               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
-       },
-       [RPCAUTH_nfs] = {
-               .name = "nfs",
-               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
-       },
-       [RPCAUTH_portmap] = {
-               .name = "portmap",
-               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
-       },
-       [RPCAUTH_statd] = {
-               .name = "statd",
-               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
-       },
-       [RPCAUTH_nfsd4_cb] = {
-               .name = "nfsd4_cb",
-               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
-       },
-};
+static int rpc_delete_dentry(const struct dentry *dentry)
+{
+       return 1;
+}
 
-enum {
-       RPCAUTH_info = 2,
-       RPCAUTH_EOF
+static const struct dentry_operations rpc_dentry_operations = {
+       .d_delete = rpc_delete_dentry,
 };
 
-static struct rpc_filelist authfiles[] = {
-       [RPCAUTH_info] = {
-               .name = "info",
-               .i_fop = &rpc_info_operations,
-               .mode = S_IFREG | S_IRUSR,
-       },
-};
+static struct inode *
+rpc_get_inode(struct super_block *sb, umode_t mode)
+{
+       struct inode *inode = new_inode(sb);
+       if (!inode)
+               return NULL;
+       inode->i_ino = get_next_ino();
+       inode->i_mode = mode;
+       inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+       switch (mode & S_IFMT) {
+       case S_IFDIR:
+               inode->i_fop = &simple_dir_operations;
+               inode->i_op = &simple_dir_inode_operations;
+               inc_nlink(inode);
+       default:
+               break;
+       }
+       return inode;
+}
 
-struct vfsmount *rpc_get_mount(void)
+static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
+                              umode_t mode,
+                              const struct file_operations *i_fop,
+                              void *private)
 {
-       int err;
+       struct inode *inode;
 
-       err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
-       if (err != 0)
-               return ERR_PTR(err);
-       return rpc_mount;
+       d_drop(dentry);
+       inode = rpc_get_inode(dir->i_sb, mode);
+       if (!inode)
+               goto out_err;
+       inode->i_ino = iunique(dir->i_sb, 100);
+       if (i_fop)
+               inode->i_fop = i_fop;
+       if (private)
+               rpc_inode_setowner(inode, private);
+       d_add(dentry, inode);
+       return 0;
+out_err:
+       printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
+                       __FILE__, __func__, dentry->d_name.name);
+       dput(dentry);
+       return -ENOMEM;
 }
 
-void rpc_put_mount(void)
+static int __rpc_create(struct inode *dir, struct dentry *dentry,
+                       umode_t mode,
+                       const struct file_operations *i_fop,
+                       void *private)
 {
-       simple_release_fs(&rpc_mount, &rpc_mount_count);
+       int err;
+
+       err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
+       if (err)
+               return err;
+       fsnotify_create(dir, dentry);
+       return 0;
 }
 
-static int rpc_delete_dentry(struct dentry *dentry)
+static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
+                      umode_t mode,
+                      const struct file_operations *i_fop,
+                      void *private)
 {
-       return 1;
+       int err;
+
+       err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
+       if (err)
+               return err;
+       inc_nlink(dir);
+       fsnotify_mkdir(dir, dentry);
+       return 0;
 }
 
-static const struct dentry_operations rpc_dentry_operations = {
-       .d_delete = rpc_delete_dentry,
-};
+static void
+init_pipe(struct rpc_pipe *pipe)
+{
+       pipe->nreaders = 0;
+       pipe->nwriters = 0;
+       INIT_LIST_HEAD(&pipe->in_upcall);
+       INIT_LIST_HEAD(&pipe->in_downcall);
+       INIT_LIST_HEAD(&pipe->pipe);
+       pipe->pipelen = 0;
+       INIT_DELAYED_WORK(&pipe->queue_timeout,
+                           rpc_timeout_upcall_queue);
+       pipe->ops = NULL;
+       spin_lock_init(&pipe->lock);
+       pipe->dentry = NULL;
+}
 
-static int
-rpc_lookup_parent(char *path, struct nameidata *nd)
+void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
 {
-       struct vfsmount *mnt;
+       kfree(pipe);
+}
+EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
 
-       if (path[0] == '\0')
-               return -ENOENT;
+struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
+{
+       struct rpc_pipe *pipe;
+
+       pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
+       if (!pipe)
+               return ERR_PTR(-ENOMEM);
+       init_pipe(pipe);
+       pipe->ops = ops;
+       pipe->flags = flags;
+       return pipe;
+}
+EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
 
-       mnt = rpc_get_mount();
-       if (IS_ERR(mnt)) {
-               printk(KERN_WARNING "%s: %s failed to mount "
-                              "pseudofilesystem \n", __FILE__, __func__);
-               return PTR_ERR(mnt);
-       }
+static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
+                              umode_t mode,
+                              const struct file_operations *i_fop,
+                              void *private,
+                              struct rpc_pipe *pipe)
+{
+       struct rpc_inode *rpci;
+       int err;
 
-       if (vfs_path_lookup(mnt->mnt_root, mnt, path, LOOKUP_PARENT, nd)) {
-               printk(KERN_WARNING "%s: %s failed to find path %s\n",
-                               __FILE__, __func__, path);
-               rpc_put_mount();
-               return -ENOENT;
-       }
+       err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
+       if (err)
+               return err;
+       rpci = RPC_I(dentry->d_inode);
+       rpci->private = private;
+       rpci->pipe = pipe;
+       fsnotify_create(dir, dentry);
        return 0;
 }
 
-static void
-rpc_release_path(struct nameidata *nd)
+static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 {
-       path_put(&nd->path);
-       rpc_put_mount();
+       int ret;
+
+       dget(dentry);
+       ret = simple_rmdir(dir, dentry);
+       d_delete(dentry);
+       dput(dentry);
+       return ret;
 }
 
-static struct inode *
-rpc_get_inode(struct super_block *sb, umode_t mode)
+int rpc_rmdir(struct dentry *dentry)
 {
-       struct inode *inode = new_inode(sb);
-       if (!inode)
-               return NULL;
-       inode->i_mode = mode;
-       inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-       switch(mode & S_IFMT) {
-               case S_IFDIR:
-                       inode->i_fop = &simple_dir_operations;
-                       inode->i_op = &simple_dir_inode_operations;
-                       inc_nlink(inode);
-               default:
-                       break;
+       struct dentry *parent;
+       struct inode *dir;
+       int error;
+
+       parent = dget_parent(dentry);
+       dir = parent->d_inode;
+       mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
+       error = __rpc_rmdir(dir, dentry);
+       mutex_unlock(&dir->i_mutex);
+       dput(parent);
+       return error;
+}
+EXPORT_SYMBOL_GPL(rpc_rmdir);
+
+static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
+{
+       int ret;
+
+       dget(dentry);
+       ret = simple_unlink(dir, dentry);
+       d_delete(dentry);
+       dput(dentry);
+       return ret;
+}
+
+static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
+{
+       struct inode *inode = dentry->d_inode;
+
+       rpc_close_pipes(inode);
+       return __rpc_unlink(dir, dentry);
+}
+
+static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
+                                         struct qstr *name)
+{
+       struct dentry *dentry;
+
+       dentry = d_lookup(parent, name);
+       if (!dentry) {
+               dentry = d_alloc(parent, name);
+               if (!dentry)
+                       return ERR_PTR(-ENOMEM);
        }
-       return inode;
+       if (dentry->d_inode == NULL) {
+               d_set_d_op(dentry, &rpc_dentry_operations);
+               return dentry;
+       }
+       dput(dentry);
+       return ERR_PTR(-EEXIST);
 }
 
 /*
  * FIXME: This probably has races.
  */
-static void rpc_depopulate(struct dentry *parent,
-                          unsigned long start, unsigned long eof)
+static void __rpc_depopulate(struct dentry *parent,
+                            const struct rpc_filelist *files,
+                            int start, int eof)
 {
        struct inode *dir = parent->d_inode;
-       struct list_head *pos, *next;
-       struct dentry *dentry, *dvec[10];
-       int n = 0;
+       struct dentry *dentry;
+       struct qstr name;
+       int i;
 
-       mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
-repeat:
-       spin_lock(&dcache_lock);
-       list_for_each_safe(pos, next, &parent->d_subdirs) {
-               dentry = list_entry(pos, struct dentry, d_u.d_child);
-               if (!dentry->d_inode ||
-                               dentry->d_inode->i_ino < start ||
-                               dentry->d_inode->i_ino >= eof)
+       for (i = start; i < eof; i++) {
+               name.name = files[i].name;
+               name.len = strlen(files[i].name);
+               name.hash = full_name_hash(name.name, name.len);
+               dentry = d_lookup(parent, &name);
+
+               if (dentry == NULL)
                        continue;
-               spin_lock(&dentry->d_lock);
-               if (!d_unhashed(dentry)) {
-                       dget_locked(dentry);
-                       __d_drop(dentry);
-                       spin_unlock(&dentry->d_lock);
-                       dvec[n++] = dentry;
-                       if (n == ARRAY_SIZE(dvec))
+               if (dentry->d_inode == NULL)
+                       goto next;
+               switch (dentry->d_inode->i_mode & S_IFMT) {
+                       default:
+                               BUG();
+                       case S_IFREG:
+                               __rpc_unlink(dir, dentry);
                                break;
-               } else
-                       spin_unlock(&dentry->d_lock);
-       }
-       spin_unlock(&dcache_lock);
-       if (n) {
-               do {
-                       dentry = dvec[--n];
-                       if (S_ISREG(dentry->d_inode->i_mode))
-                               simple_unlink(dir, dentry);
-                       else if (S_ISDIR(dentry->d_inode->i_mode))
-                               simple_rmdir(dir, dentry);
-                       d_delete(dentry);
-                       dput(dentry);
-               } while (n);
-               goto repeat;
+                       case S_IFDIR:
+                               __rpc_rmdir(dir, dentry);
+               }
+next:
+               dput(dentry);
        }
+}
+
+static void rpc_depopulate(struct dentry *parent,
+                          const struct rpc_filelist *files,
+                          int start, int eof)
+{
+       struct inode *dir = parent->d_inode;
+
+       mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
+       __rpc_depopulate(parent, files, start, eof);
        mutex_unlock(&dir->i_mutex);
 }
 
-static int
-rpc_populate(struct dentry *parent,
-               struct rpc_filelist *files,
-               int start, int eof)
+static int rpc_populate(struct dentry *parent,
+                       const struct rpc_filelist *files,
+                       int start, int eof,
+                       void *private)
 {
-       struct inode *inode, *dir = parent->d_inode;
-       void *private = RPC_I(dir)->private;
+       struct inode *dir = parent->d_inode;
        struct dentry *dentry;
-       umode_t mode;
-       int i;
+       int i, err;
 
        mutex_lock(&dir->i_mutex);
        for (i = start; i < eof; i++) {
-               dentry = d_alloc_name(parent, files[i].name);
-               if (!dentry)
-                       goto out_bad;
-               dentry->d_op = &rpc_dentry_operations;
-               mode = files[i].mode;
-               inode = rpc_get_inode(dir->i_sb, mode);
-               if (!inode) {
-                       dput(dentry);
+               struct qstr q;
+
+               q.name = files[i].name;
+               q.len = strlen(files[i].name);
+               q.hash = full_name_hash(q.name, q.len);
+               dentry = __rpc_lookup_create_exclusive(parent, &q);
+               err = PTR_ERR(dentry);
+               if (IS_ERR(dentry))
                        goto out_bad;
+               switch (files[i].mode & S_IFMT) {
+                       default:
+                               BUG();
+                       case S_IFREG:
+                               err = __rpc_create(dir, dentry,
+                                               files[i].mode,
+                                               files[i].i_fop,
+                                               private);
+                               break;
+                       case S_IFDIR:
+                               err = __rpc_mkdir(dir, dentry,
+                                               files[i].mode,
+                                               NULL,
+                                               private);
                }
-               inode->i_ino = i;
-               if (files[i].i_fop)
-                       inode->i_fop = files[i].i_fop;
-               if (private)
-                       rpc_inode_setowner(inode, private);
-               if (S_ISDIR(mode))
-                       inc_nlink(dir);
-               d_add(dentry, inode);
-               fsnotify_create(dir, dentry);
+               if (err != 0)
+                       goto out_bad;
        }
        mutex_unlock(&dir->i_mutex);
        return 0;
 out_bad:
+       __rpc_depopulate(parent, files, start, eof);
        mutex_unlock(&dir->i_mutex);
        printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
                        __FILE__, __func__, parent->d_name.name);
-       return -ENOMEM;
-}
-
-static int
-__rpc_mkdir(struct inode *dir, struct dentry *dentry)
-{
-       struct inode *inode;
-
-       inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
-       if (!inode)
-               goto out_err;
-       inode->i_ino = iunique(dir->i_sb, 100);
-       d_instantiate(dentry, inode);
-       inc_nlink(dir);
-       fsnotify_mkdir(dir, dentry);
-       return 0;
-out_err:
-       printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
-                       __FILE__, __func__, dentry->d_name.name);
-       return -ENOMEM;
-}
-
-static int
-__rpc_rmdir(struct inode *dir, struct dentry *dentry)
-{
-       int error;
-       error = simple_rmdir(dir, dentry);
-       if (!error)
-               d_delete(dentry);
-       return error;
+       return err;
 }
 
-static struct dentry *
-rpc_lookup_create(struct dentry *parent, const char *name, int len, int exclusive)
+static struct dentry *rpc_mkdir_populate(struct dentry *parent,
+               struct qstr *name, umode_t mode, void *private,
+               int (*populate)(struct dentry *, void *), void *args_populate)
 {
-       struct inode *dir = parent->d_inode;
        struct dentry *dentry;
+       struct inode *dir = parent->d_inode;
+       int error;
 
        mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
-       dentry = lookup_one_len(name, parent, len);
+       dentry = __rpc_lookup_create_exclusive(parent, name);
        if (IS_ERR(dentry))
+               goto out;
+       error = __rpc_mkdir(dir, dentry, mode, NULL, private);
+       if (error != 0)
                goto out_err;
-       if (!dentry->d_inode)
-               dentry->d_op = &rpc_dentry_operations;
-       else if (exclusive) {
-               dput(dentry);
-               dentry = ERR_PTR(-EEXIST);
-               goto out_err;
+       if (populate != NULL) {
+               error = populate(dentry, args_populate);
+               if (error)
+                       goto err_rmdir;
        }
-       return dentry;
-out_err:
-       mutex_unlock(&dir->i_mutex);
-       return dentry;
-}
-
-static struct dentry *
-rpc_lookup_negative(char *path, struct nameidata *nd)
-{
-       struct dentry *dentry;
-       int error;
-
-       if ((error = rpc_lookup_parent(path, nd)) != 0)
-               return ERR_PTR(error);
-       dentry = rpc_lookup_create(nd->path.dentry, nd->last.name, nd->last.len,
-                                  1);
-       if (IS_ERR(dentry))
-               rpc_release_path(nd);
-       return dentry;
-}
-
-/**
- * rpc_mkdir - Create a new directory in rpc_pipefs
- * @path: path from the rpc_pipefs root to the new directory
- * @rpc_client: rpc client to associate with this directory
- *
- * This creates a directory at the given @path associated with
- * @rpc_clnt, which will contain a file named "info" with some basic
- * information about the client, together with any "pipes" that may
- * later be created using rpc_mkpipe().
- */
-struct dentry *
-rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
-{
-       struct nameidata nd;
-       struct dentry *dentry;
-       struct inode *dir;
-       int error;
-
-       dentry = rpc_lookup_negative(path, &nd);
-       if (IS_ERR(dentry))
-               return dentry;
-       dir = nd.path.dentry->d_inode;
-       if ((error = __rpc_mkdir(dir, dentry)) != 0)
-               goto err_dput;
-       RPC_I(dentry->d_inode)->private = rpc_client;
-       error = rpc_populate(dentry, authfiles,
-                       RPCAUTH_info, RPCAUTH_EOF);
-       if (error)
-               goto err_depopulate;
-       dget(dentry);
 out:
        mutex_unlock(&dir->i_mutex);
-       rpc_release_path(&nd);
        return dentry;
-err_depopulate:
-       rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
+err_rmdir:
        __rpc_rmdir(dir, dentry);
-err_dput:
-       dput(dentry);
-       printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
-                       __FILE__, __func__, path, error);
+out_err:
        dentry = ERR_PTR(error);
        goto out;
 }
 
-/**
- * rpc_rmdir - Remove a directory created with rpc_mkdir()
- * @dentry: directory to remove
- */
-int
-rpc_rmdir(struct dentry *dentry)
+static int rpc_rmdir_depopulate(struct dentry *dentry,
+               void (*depopulate)(struct dentry *))
 {
        struct dentry *parent;
        struct inode *dir;
@@ -749,9 +806,9 @@ rpc_rmdir(struct dentry *dentry)
        parent = dget_parent(dentry);
        dir = parent->d_inode;
        mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
-       rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
+       if (depopulate != NULL)
+               depopulate(dentry);
        error = __rpc_rmdir(dir, dentry);
-       dput(dentry);
        mutex_unlock(&dir->i_mutex);
        dput(parent);
        return error;
@@ -764,7 +821,7 @@ rpc_rmdir(struct dentry *dentry)
  * @private: private data to associate with the pipe, for the caller's use
  * @ops: operations defining the behavior of the pipe: upcall, downcall,
  *     release_pipe, open_pipe, and destroy_msg.
- * @flags: rpc_inode flags
+ * @flags: rpc_pipe flags
  *
  * Data is made available for userspace to read by calls to
  * rpc_queue_upcall().  The actual reads will result in calls to
@@ -777,60 +834,43 @@ rpc_rmdir(struct dentry *dentry)
  * The @private argument passed here will be available to all these methods
  * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private.
  */
-struct dentry *rpc_mkpipe(struct dentry *parent, const char *name,
-                         void *private, const struct rpc_pipe_ops *ops,
-                         int flags)
+struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
+                                void *private, struct rpc_pipe *pipe)
 {
        struct dentry *dentry;
-       struct inode *dir, *inode;
-       struct rpc_inode *rpci;
+       struct inode *dir = parent->d_inode;
        umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
+       struct qstr q;
+       int err;
 
-       if (ops->upcall == NULL)
+       if (pipe->ops->upcall == NULL)
                umode &= ~S_IRUGO;
-       if (ops->downcall == NULL)
+       if (pipe->ops->downcall == NULL)
                umode &= ~S_IWUGO;
 
-       dentry = rpc_lookup_create(parent, name, strlen(name), 0);
+       q.name = name;
+       q.len = strlen(name);
+       q.hash = full_name_hash(q.name, q.len),
+
+       mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
+       dentry = __rpc_lookup_create_exclusive(parent, &q);
        if (IS_ERR(dentry))
-               return dentry;
-       dir = parent->d_inode;
-       if (dentry->d_inode) {
-               rpci = RPC_I(dentry->d_inode);
-               if (rpci->private != private ||
-                               rpci->ops != ops ||
-                               rpci->flags != flags) {
-                       dput (dentry);
-                       dentry = ERR_PTR(-EBUSY);
-               }
-               rpci->nkern_readwriters++;
                goto out;
-       }
-       inode = rpc_get_inode(dir->i_sb, umode);
-       if (!inode)
-               goto err_dput;
-       inode->i_ino = iunique(dir->i_sb, 100);
-       inode->i_fop = &rpc_pipe_fops;
-       d_instantiate(dentry, inode);
-       rpci = RPC_I(inode);
-       rpci->private = private;
-       rpci->flags = flags;
-       rpci->ops = ops;
-       rpci->nkern_readwriters = 1;
-       fsnotify_create(dir, dentry);
-       dget(dentry);
+       err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
+                                 private, pipe);
+       if (err)
+               goto out_err;
 out:
        mutex_unlock(&dir->i_mutex);
        return dentry;
-err_dput:
-       dput(dentry);
-       dentry = ERR_PTR(-ENOMEM);
+out_err:
+       dentry = ERR_PTR(err);
        printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
                        __FILE__, __func__, parent->d_name.name, name,
-                       -ENOMEM);
+                       err);
        goto out;
 }
-EXPORT_SYMBOL_GPL(rpc_mkpipe);
+EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
 
 /**
  * rpc_unlink - remove a pipe
@@ -850,23 +890,112 @@ rpc_unlink(struct dentry *dentry)
        parent = dget_parent(dentry);
        dir = parent->d_inode;
        mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
-       if (--RPC_I(dentry->d_inode)->nkern_readwriters == 0) {
-               rpc_close_pipes(dentry->d_inode);
-               error = simple_unlink(dir, dentry);
-               if (!error)
-                       d_delete(dentry);
-       }
-       dput(dentry);
+       error = __rpc_rmpipe(dir, dentry);
        mutex_unlock(&dir->i_mutex);
        dput(parent);
        return error;
 }
 EXPORT_SYMBOL_GPL(rpc_unlink);
 
+enum {
+       RPCAUTH_info,
+       RPCAUTH_EOF
+};
+
+static const struct rpc_filelist authfiles[] = {
+       [RPCAUTH_info] = {
+               .name = "info",
+               .i_fop = &rpc_info_operations,
+               .mode = S_IFREG | S_IRUSR,
+       },
+};
+
+static int rpc_clntdir_populate(struct dentry *dentry, void *private)
+{
+       return rpc_populate(dentry,
+                           authfiles, RPCAUTH_info, RPCAUTH_EOF,
+                           private);
+}
+
+static void rpc_clntdir_depopulate(struct dentry *dentry)
+{
+       rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
+}
+
+/**
+ * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
+ * @dentry: dentry from the rpc_pipefs root to the new directory
+ * @name: &struct qstr for the name
+ * @rpc_client: rpc client to associate with this directory
+ *
+ * This creates a directory at the given @path associated with
+ * @rpc_clnt, which will contain a file named "info" with some basic
+ * information about the client, together with any "pipes" that may
+ * later be created using rpc_mkpipe().
+ */
+struct dentry *rpc_create_client_dir(struct dentry *dentry,
+                                  struct qstr *name,
+                                  struct rpc_clnt *rpc_client)
+{
+       return rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
+                       rpc_clntdir_populate, rpc_client);
+}
+
+/**
+ * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
+ * @clnt: rpc client
+ */
+int rpc_remove_client_dir(struct dentry *dentry)
+{
+       return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
+}
+
+static const struct rpc_filelist cache_pipefs_files[3] = {
+       [0] = {
+               .name = "channel",
+               .i_fop = &cache_file_operations_pipefs,
+               .mode = S_IFREG|S_IRUSR|S_IWUSR,
+       },
+       [1] = {
+               .name = "content",
+               .i_fop = &content_file_operations_pipefs,
+               .mode = S_IFREG|S_IRUSR,
+       },
+       [2] = {
+               .name = "flush",
+               .i_fop = &cache_flush_operations_pipefs,
+               .mode = S_IFREG|S_IRUSR|S_IWUSR,
+       },
+};
+
+static int rpc_cachedir_populate(struct dentry *dentry, void *private)
+{
+       return rpc_populate(dentry,
+                           cache_pipefs_files, 0, 3,
+                           private);
+}
+
+static void rpc_cachedir_depopulate(struct dentry *dentry)
+{
+       rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
+}
+
+struct dentry *rpc_create_cache_dir(struct dentry *parent, struct qstr *name,
+                                   umode_t umode, struct cache_detail *cd)
+{
+       return rpc_mkdir_populate(parent, name, umode, NULL,
+                       rpc_cachedir_populate, cd);
+}
+
+void rpc_remove_cache_dir(struct dentry *dentry)
+{
+       rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
+}
+
 /*
  * populate the filesystem
  */
-static struct super_operations s_ops = {
+static const struct super_operations s_ops = {
        .alloc_inode    = rpc_alloc_inode,
        .destroy_inode  = rpc_destroy_inode,
        .statfs         = simple_statfs,
@@ -874,11 +1003,111 @@ static struct super_operations s_ops = {
 
 #define RPCAUTH_GSSMAGIC 0x67596969
 
+/*
+ * We have a single directory with 1 node in it.
+ */
+enum {
+       RPCAUTH_lockd,
+       RPCAUTH_mount,
+       RPCAUTH_nfs,
+       RPCAUTH_portmap,
+       RPCAUTH_statd,
+       RPCAUTH_nfsd4_cb,
+       RPCAUTH_cache,
+       RPCAUTH_nfsd,
+       RPCAUTH_RootEOF
+};
+
+static const struct rpc_filelist files[] = {
+       [RPCAUTH_lockd] = {
+               .name = "lockd",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
+       [RPCAUTH_mount] = {
+               .name = "mount",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
+       [RPCAUTH_nfs] = {
+               .name = "nfs",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
+       [RPCAUTH_portmap] = {
+               .name = "portmap",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
+       [RPCAUTH_statd] = {
+               .name = "statd",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
+       [RPCAUTH_nfsd4_cb] = {
+               .name = "nfsd4_cb",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
+       [RPCAUTH_cache] = {
+               .name = "cache",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
+       [RPCAUTH_nfsd] = {
+               .name = "nfsd",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
+};
+
+/*
+ * This call can be used only in RPC pipefs mount notification hooks.
+ */
+struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
+                              const unsigned char *dir_name)
+{
+       struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
+
+       dir.hash = full_name_hash(dir.name, dir.len);
+       return d_lookup(sb->s_root, &dir);
+}
+EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
+
+void rpc_pipefs_init_net(struct net *net)
+{
+       struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+       mutex_init(&sn->pipefs_sb_lock);
+}
+
+/*
+ * This call will be used for per network namespace operations calls.
+ * Note: Function will be returned with pipefs_sb_lock taken if superblock was
+ * found. This lock have to be released by rpc_put_sb_net() when all operations
+ * will be completed.
+ */
+struct super_block *rpc_get_sb_net(const struct net *net)
+{
+       struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+       mutex_lock(&sn->pipefs_sb_lock);
+       if (sn->pipefs_sb)
+               return sn->pipefs_sb;
+       mutex_unlock(&sn->pipefs_sb_lock);
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(rpc_get_sb_net);
+
+void rpc_put_sb_net(const struct net *net)
+{
+       struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+       BUG_ON(sn->pipefs_sb == NULL);
+       mutex_unlock(&sn->pipefs_sb_lock);
+}
+EXPORT_SYMBOL_GPL(rpc_put_sb_net);
+
 static int
 rpc_fill_super(struct super_block *sb, void *data, int silent)
 {
        struct inode *inode;
        struct dentry *root;
+       struct net *net = data;
+       struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+       int err;
 
        sb->s_blocksize = PAGE_CACHE_SIZE;
        sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
@@ -887,35 +1116,60 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
        sb->s_time_gran = 1;
 
        inode = rpc_get_inode(sb, S_IFDIR | 0755);
-       if (!inode)
+       sb->s_root = root = d_make_root(inode);
+       if (!root)
                return -ENOMEM;
-       root = d_alloc_root(inode);
-       if (!root) {
-               iput(inode);
+       if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
                return -ENOMEM;
-       }
-       if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
-               goto out;
-       sb->s_root = root;
+       dprintk("RPC:   sending pipefs MOUNT notification for net %p%s\n", net,
+                                                               NET_NAME(net));
+       sn->pipefs_sb = sb;
+       err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
+                                          RPC_PIPEFS_MOUNT,
+                                          sb);
+       if (err)
+               goto err_depopulate;
+       sb->s_fs_info = get_net(net);
        return 0;
-out:
-       d_genocide(root);
-       dput(root);
-       return -ENOMEM;
+
+err_depopulate:
+       blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
+                                          RPC_PIPEFS_UMOUNT,
+                                          sb);
+       sn->pipefs_sb = NULL;
+       __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
+       return err;
 }
 
-static int
-rpc_get_sb(struct file_system_type *fs_type,
-               int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *
+rpc_mount(struct file_system_type *fs_type,
+               int flags, const char *dev_name, void *data)
 {
-       return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
+       return mount_ns(fs_type, flags, current->nsproxy->net_ns, rpc_fill_super);
+}
+
+static void rpc_kill_sb(struct super_block *sb)
+{
+       struct net *net = sb->s_fs_info;
+       struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+       mutex_lock(&sn->pipefs_sb_lock);
+       sn->pipefs_sb = NULL;
+       mutex_unlock(&sn->pipefs_sb_lock);
+       put_net(net);
+       dprintk("RPC:   sending pipefs UMOUNT notification for net %p%s\n", net,
+                                                               NET_NAME(net));
+       blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
+                                          RPC_PIPEFS_UMOUNT,
+                                          sb);
+       kill_litter_super(sb);
 }
 
 static struct file_system_type rpc_pipe_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "rpc_pipefs",
-       .get_sb         = rpc_get_sb,
-       .kill_sb        = kill_litter_super,
+       .mount          = rpc_mount,
+       .kill_sb        = rpc_kill_sb,
 };
 
 static void
@@ -925,16 +1179,8 @@ init_once(void *foo)
 
        inode_init_once(&rpci->vfs_inode);
        rpci->private = NULL;
-       rpci->nreaders = 0;
-       rpci->nwriters = 0;
-       INIT_LIST_HEAD(&rpci->in_upcall);
-       INIT_LIST_HEAD(&rpci->in_downcall);
-       INIT_LIST_HEAD(&rpci->pipe);
-       rpci->pipelen = 0;
+       rpci->pipe = NULL;
        init_waitqueue_head(&rpci->waitq);
-       INIT_DELAYED_WORK(&rpci->queue_timeout,
-                           rpc_timeout_upcall_queue);
-       rpci->ops = NULL;
 }
 
 int register_rpc_pipefs(void)
@@ -948,17 +1194,27 @@ int register_rpc_pipefs(void)
                                init_once);
        if (!rpc_inode_cachep)
                return -ENOMEM;
+       err = rpc_clients_notifier_register();
+       if (err)
+               goto err_notifier;
        err = register_filesystem(&rpc_pipe_fs_type);
-       if (err) {
-               kmem_cache_destroy(rpc_inode_cachep);
-               return err;
-       }
-
+       if (err)
+               goto err_register;
        return 0;
+
+err_register:
+       rpc_clients_notifier_unregister();
+err_notifier:
+       kmem_cache_destroy(rpc_inode_cachep);
+       return err;
 }
 
 void unregister_rpc_pipefs(void)
 {
+       rpc_clients_notifier_unregister();
        kmem_cache_destroy(rpc_inode_cachep);
        unregister_filesystem(&rpc_pipe_fs_type);
 }
+
+/* Make 'mount -t rpc_pipefs ...' autoload this module. */
+MODULE_ALIAS("rpc_pipefs");