net/sunrpc/rpc_pipe.c

   1 /*
   2  * net/sunrpc/rpc_pipe.c
   3  *
   4  * Userland/kernel interface for rpcauth_gss.
   5  * Code shamelessly plagiarized from fs/nfsd/nfsctl.c
   6  * and fs/sysfs/inode.c
   7  *
   8  * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
   9  *
  10  */
  11 #include <linux/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/string.h>
  14 #include <linux/pagemap.h>
  15 #include <linux/mount.h>
  16 #include <linux/namei.h>
  17 #include <linux/fsnotify.h>
  18 #include <linux/kernel.h>
  19 #include <linux/rcupdate.h>
  20
  21 #include <asm/ioctls.h>
  22 #include <linux/poll.h>
  23 #include <linux/wait.h>
  24 #include <linux/seq_file.h>
  25
  26 #include <linux/sunrpc/clnt.h>
  27 #include <linux/workqueue.h>
  28 #include <linux/sunrpc/rpc_pipe_fs.h>
  29 #include <linux/sunrpc/cache.h>
  30 #include <linux/nsproxy.h>
  31 #include <linux/notifier.h>
  32
  33 #include "netns.h"
  34 #include "sunrpc.h"
  35
  36 #define RPCDBG_FACILITY RPCDBG_DEBUG
  37
  38 #define NET_NAME(net)   ((net == &init_net) ? " (init_net)" : "")
  39
  40 static struct file_system_type rpc_pipe_fs_type;
  41
  42
  43 static struct kmem_cache *rpc_inode_cachep __read_mostly;
  44
  45 #define RPC_UPCALL_TIMEOUT (30*HZ)
  46
  47 static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
  48
  49 int rpc_pipefs_notifier_register(struct notifier_block *nb)
  50 {
  51         return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
  52 }
  53 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
  54
  55 void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
  56 {
  57         blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
  58 }
  59 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
  60
  61 static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head,
  62                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
  63 {
  64         struct rpc_pipe_msg *msg;
  65
  66         if (list_empty(head))
  67                 return;
  68         do {
  69                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
  70                 list_del_init(&msg->list);
  71                 msg->errno = err;
  72                 destroy_msg(msg);
  73         } while (!list_empty(head));
  74
  75         if (waitq)
  76                 wake_up(waitq);
  77 }
  78
  79 static void
  80 rpc_timeout_upcall_queue(struct work_struct *work)
  81 {
  82         LIST_HEAD(free_list);
  83         struct rpc_pipe *pipe =
  84                 container_of(work, struct rpc_pipe, queue_timeout.work);
  85         void (*destroy_msg)(struct rpc_pipe_msg *);
  86         struct dentry *dentry;
  87
  88         spin_lock(&pipe->lock);
  89         destroy_msg = pipe->ops->destroy_msg;
  90         if (pipe->nreaders == 0) {
  91                 list_splice_init(&pipe->pipe, &free_list);
  92                 pipe->pipelen = 0;
  93         }
  94         dentry = dget(pipe->dentry);
  95         spin_unlock(&pipe->lock);
  96         rpc_purge_list(dentry ? &RPC_I(dentry->d_inode)->waitq : NULL,
  97                         &free_list, destroy_msg, -ETIMEDOUT);
  98         dput(dentry);
  99 }
 100
 101 ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 102                                 char __user *dst, size_t buflen)
 103 {
 104         char *data = (char *)msg->data + msg->copied;
 105         size_t mlen = min(msg->len - msg->copied, buflen);
 106         unsigned long left;
 107
 108         left = copy_to_user(dst, data, mlen);
 109         if (left == mlen) {
 110                 msg->errno = -EFAULT;
 111                 return -EFAULT;
 112         }
 113
 114         mlen -= left;
 115         msg->copied += mlen;
 116         msg->errno = 0;
 117         return mlen;
 118 }
 119 EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
 120
 121 /**
 122  * rpc_queue_upcall - queue an upcall message to userspace
 123  * @pipe: upcall pipe on which to queue given message
 124  * @msg: message to queue
 125  *
 126  * Call with an @inode created by rpc_mkpipe() to queue an upcall.
 127  * A userspace process may then later read the upcall by performing a
 128  * read on an open file for this inode.  It is up to the caller to
 129  * initialize the fields of @msg (other than @msg->list) appropriately.
 130  */
 131 int
 132 rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
 133 {
 134         int res = -EPIPE;
 135         struct dentry *dentry;
 136
 137         spin_lock(&pipe->lock);
 138         if (pipe->nreaders) {
 139                 list_add_tail(&msg->list, &pipe->pipe);
 140                 pipe->pipelen += msg->len;
 141                 res = 0;
 142         } else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
 143                 if (list_empty(&pipe->pipe))
 144                         queue_delayed_work(rpciod_workqueue,
 145                                         &pipe->queue_timeout,
 146                                         RPC_UPCALL_TIMEOUT);
 147                 list_add_tail(&msg->list, &pipe->pipe);
 148                 pipe->pipelen += msg->len;
 149                 res = 0;
 150         }
 151         dentry = dget(pipe->dentry);
 152         spin_unlock(&pipe->lock);
 153         if (dentry) {
 154                 wake_up(&RPC_I(dentry->d_inode)->waitq);
 155                 dput(dentry);
 156         }
 157         return res;
 158 }
 159 EXPORT_SYMBOL_GPL(rpc_queue_upcall);
 160
 161 static inline void
 162 rpc_inode_setowner(struct inode *inode, void *private)
 163 {
 164         RPC_I(inode)->private = private;
 165 }
 166
 167 static void
 168 rpc_close_pipes(struct inode *inode)
 169 {
 170         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 171         int need_release;
 172         LIST_HEAD(free_list);
 173
 174         mutex_lock(&inode->i_mutex);
 175         spin_lock(&pipe->lock);
 176         need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
 177         pipe->nreaders = 0;
 178         list_splice_init(&pipe->in_upcall, &free_list);
 179         list_splice_init(&pipe->pipe, &free_list);
 180         pipe->pipelen = 0;
 181         pipe->dentry = NULL;
 182         spin_unlock(&pipe->lock);
 183         rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
 184         pipe->nwriters = 0;
 185         if (need_release && pipe->ops->release_pipe)
 186                 pipe->ops->release_pipe(inode);
 187         cancel_delayed_work_sync(&pipe->queue_timeout);
 188         rpc_inode_setowner(inode, NULL);
 189         RPC_I(inode)->pipe = NULL;
 190         mutex_unlock(&inode->i_mutex);
 191 }
 192
 193 static struct inode *
 194 rpc_alloc_inode(struct super_block *sb)
 195 {
 196         struct rpc_inode *rpci;
 197         rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
 198         if (!rpci)
 199                 return NULL;
 200         return &rpci->vfs_inode;
 201 }
 202
 203 static void
 204 rpc_i_callback(struct rcu_head *head)
 205 {
 206         struct inode *inode = container_of(head, struct inode, i_rcu);
 207         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 208 }
 209
 210 static void
 211 rpc_destroy_inode(struct inode *inode)
 212 {
 213         call_rcu(&inode->i_rcu, rpc_i_callback);
 214 }
 215
 216 static int
 217 rpc_pipe_open(struct inode *inode, struct file *filp)
 218 {
 219         struct net *net = inode->i_sb->s_fs_info;
 220         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 221         struct rpc_pipe *pipe;
 222         int first_open;
 223         int res = -ENXIO;
 224
 225         mutex_lock(&inode->i_mutex);
 226         sn->gssd_running = 1;
 227         pipe = RPC_I(inode)->pipe;
 228         if (pipe == NULL)
 229                 goto out;
 230         first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
 231         if (first_open && pipe->ops->open_pipe) {
 232                 res = pipe->ops->open_pipe(inode);
 233                 if (res)
 234                         goto out;
 235         }
 236         if (filp->f_mode & FMODE_READ)
 237                 pipe->nreaders++;
 238         if (filp->f_mode & FMODE_WRITE)
 239                 pipe->nwriters++;
 240         res = 0;
 241 out:
 242         mutex_unlock(&inode->i_mutex);
 243         return res;
 244 }
 245
 246 static int
 247 rpc_pipe_release(struct inode *inode, struct file *filp)
 248 {
 249         struct rpc_pipe *pipe;
 250         struct rpc_pipe_msg *msg;
 251         int last_close;
 252
 253         mutex_lock(&inode->i_mutex);
 254         pipe = RPC_I(inode)->pipe;
 255         if (pipe == NULL)
 256                 goto out;
 257         msg = filp->private_data;
 258         if (msg != NULL) {
 259                 spin_lock(&pipe->lock);
 260                 msg->errno = -EAGAIN;
 261                 list_del_init(&msg->list);
 262                 spin_unlock(&pipe->lock);
 263                 pipe->ops->destroy_msg(msg);
 264         }
 265         if (filp->f_mode & FMODE_WRITE)
 266                 pipe->nwriters --;
 267         if (filp->f_mode & FMODE_READ) {
 268                 pipe->nreaders --;
 269                 if (pipe->nreaders == 0) {
 270                         LIST_HEAD(free_list);
 271                         spin_lock(&pipe->lock);
 272                         list_splice_init(&pipe->pipe, &free_list);
 273                         pipe->pipelen = 0;
 274                         spin_unlock(&pipe->lock);
 275                         rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
 276                                         pipe->ops->destroy_msg, -EAGAIN);
 277                 }
 278         }
 279         last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
 280         if (last_close && pipe->ops->release_pipe)
 281                 pipe->ops->release_pipe(inode);
 282 out:
 283         mutex_unlock(&inode->i_mutex);
 284         return 0;
 285 }
 286
 287 static ssize_t
 288 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 289 {
 290         struct inode *inode = file_inode(filp);
 291         struct rpc_pipe *pipe;
 292         struct rpc_pipe_msg *msg;
 293         int res = 0;
 294
 295         mutex_lock(&inode->i_mutex);
 296         pipe = RPC_I(inode)->pipe;
 297         if (pipe == NULL) {
 298                 res = -EPIPE;
 299                 goto out_unlock;
 300         }
 301         msg = filp->private_data;
 302         if (msg == NULL) {
 303                 spin_lock(&pipe->lock);
 304                 if (!list_empty(&pipe->pipe)) {
 305                         msg = list_entry(pipe->pipe.next,
 306                                         struct rpc_pipe_msg,
 307                                         list);
 308                         list_move(&msg->list, &pipe->in_upcall);
 309                         pipe->pipelen -= msg->len;
 310                         filp->private_data = msg;
 311                         msg->copied = 0;
 312                 }
 313                 spin_unlock(&pipe->lock);
 314                 if (msg == NULL)
 315                         goto out_unlock;
 316         }
 317         /* NOTE: it is up to the callback to update msg->copied */
 318         res = pipe->ops->upcall(filp, msg, buf, len);
 319         if (res < 0 || msg->len == msg->copied) {
 320                 filp->private_data = NULL;
 321                 spin_lock(&pipe->lock);
 322                 list_del_init(&msg->list);
 323                 spin_unlock(&pipe->lock);
 324                 pipe->ops->destroy_msg(msg);
 325         }
 326 out_unlock:
 327         mutex_unlock(&inode->i_mutex);
 328         return res;
 329 }
 330
 331 static ssize_t
 332 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 333 {
 334         struct inode *inode = file_inode(filp);
 335         int res;
 336
 337         mutex_lock(&inode->i_mutex);
 338         res = -EPIPE;
 339         if (RPC_I(inode)->pipe != NULL)
 340                 res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
 341         mutex_unlock(&inode->i_mutex);
 342         return res;
 343 }
 344
 345 static unsigned int
 346 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 347 {
 348         struct inode *inode = file_inode(filp);
 349         struct rpc_inode *rpci = RPC_I(inode);
 350         unsigned int mask = POLLOUT | POLLWRNORM;
 351
 352         poll_wait(filp, &rpci->waitq, wait);
 353
 354         mutex_lock(&inode->i_mutex);
 355         if (rpci->pipe == NULL)
 356                 mask |= POLLERR | POLLHUP;
 357         else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
 358                 mask |= POLLIN | POLLRDNORM;
 359         mutex_unlock(&inode->i_mutex);
 360         return mask;
 361 }
 362
 363 static long
 364 rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 365 {
 366         struct inode *inode = file_inode(filp);
 367         struct rpc_pipe *pipe;
 368         int len;
 369
 370         switch (cmd) {
 371         case FIONREAD:
 372                 mutex_lock(&inode->i_mutex);
 373                 pipe = RPC_I(inode)->pipe;
 374                 if (pipe == NULL) {
 375                         mutex_unlock(&inode->i_mutex);
 376                         return -EPIPE;
 377                 }
 378                 spin_lock(&pipe->lock);
 379                 len = pipe->pipelen;
 380                 if (filp->private_data) {
 381                         struct rpc_pipe_msg *msg;
 382                         msg = filp->private_data;
 383                         len += msg->len - msg->copied;
 384                 }
 385                 spin_unlock(&pipe->lock);
 386                 mutex_unlock(&inode->i_mutex);
 387                 return put_user(len, (int __user *)arg);
 388         default:
 389                 return -EINVAL;
 390         }
 391 }
 392
 393 static const struct file_operations rpc_pipe_fops = {
 394         .owner          = THIS_MODULE,
 395         .llseek         = no_llseek,
 396         .read           = rpc_pipe_read,
 397         .write          = rpc_pipe_write,
 398         .poll           = rpc_pipe_poll,
 399         .unlocked_ioctl = rpc_pipe_ioctl,
 400         .open           = rpc_pipe_open,
 401         .release        = rpc_pipe_release,
 402 };
 403
 404 static int
 405 rpc_show_info(struct seq_file *m, void *v)
 406 {
 407         struct rpc_clnt *clnt = m->private;
 408
 409         rcu_read_lock();
 410         seq_printf(m, "RPC server: %s\n",
 411                         rcu_dereference(clnt->cl_xprt)->servername);
 412         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_program->name,
 413                         clnt->cl_prog, clnt->cl_vers);
 414         seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
 415         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
 416         seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
 417         rcu_read_unlock();
 418         return 0;
 419 }
 420
 421 static int
 422 rpc_info_open(struct inode *inode, struct file *file)
 423 {
 424         struct rpc_clnt *clnt = NULL;
 425         int ret = single_open(file, rpc_show_info, NULL);
 426
 427         if (!ret) {
 428                 struct seq_file *m = file->private_data;
 429
 430                 spin_lock(&file->f_path.dentry->d_lock);
 431                 if (!d_unhashed(file->f_path.dentry))
 432                         clnt = RPC_I(inode)->private;
 433                 if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
 434                         spin_unlock(&file->f_path.dentry->d_lock);
 435                         m->private = clnt;
 436                 } else {
 437                         spin_unlock(&file->f_path.dentry->d_lock);
 438                         single_release(inode, file);
 439                         ret = -EINVAL;
 440                 }
 441         }
 442         return ret;
 443 }
 444
 445 static int
 446 rpc_info_release(struct inode *inode, struct file *file)
 447 {
 448         struct seq_file *m = file->private_data;
 449         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
 450
 451         if (clnt)
 452                 rpc_release_client(clnt);
 453         return single_release(inode, file);
 454 }
 455
 456 static const struct file_operations rpc_info_operations = {
 457         .owner          = THIS_MODULE,
 458         .open           = rpc_info_open,
 459         .read           = seq_read,
 460         .llseek         = seq_lseek,
 461         .release        = rpc_info_release,
 462 };
 463
 464
 465 /*
 466  * Description of fs contents.
 467  */
 468 struct rpc_filelist {
 469         const char *name;
 470         const struct file_operations *i_fop;
 471         umode_t mode;
 472 };
 473
 474 static struct inode *
 475 rpc_get_inode(struct super_block *sb, umode_t mode)
 476 {
 477         struct inode *inode = new_inode(sb);
 478         if (!inode)
 479                 return NULL;
 480         inode->i_ino = get_next_ino();
 481         inode->i_mode = mode;
 482         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 483         switch (mode & S_IFMT) {
 484         case S_IFDIR:
 485                 inode->i_fop = &simple_dir_operations;
 486                 inode->i_op = &simple_dir_inode_operations;
 487                 inc_nlink(inode);
 488         default:
 489                 break;
 490         }
 491         return inode;
 492 }
 493
 494 static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
 495                                umode_t mode,
 496                                const struct file_operations *i_fop,
 497                                void *private)
 498 {
 499         struct inode *inode;
 500
 501         d_drop(dentry);
 502         inode = rpc_get_inode(dir->i_sb, mode);
 503         if (!inode)
 504                 goto out_err;
 505         inode->i_ino = iunique(dir->i_sb, 100);
 506         if (i_fop)
 507                 inode->i_fop = i_fop;
 508         if (private)
 509                 rpc_inode_setowner(inode, private);
 510         d_add(dentry, inode);
 511         return 0;
 512 out_err:
 513         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %pd\n",
 514                         __FILE__, __func__, dentry);
 515         dput(dentry);
 516         return -ENOMEM;
 517 }
 518
 519 static int __rpc_create(struct inode *dir, struct dentry *dentry,
 520                         umode_t mode,
 521                         const struct file_operations *i_fop,
 522                         void *private)
 523 {
 524         int err;
 525
 526         err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
 527         if (err)
 528                 return err;
 529         fsnotify_create(dir, dentry);
 530         return 0;
 531 }
 532
 533 static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
 534                        umode_t mode,
 535                        const struct file_operations *i_fop,
 536                        void *private)
 537 {
 538         int err;
 539
 540         err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
 541         if (err)
 542                 return err;
 543         inc_nlink(dir);
 544         fsnotify_mkdir(dir, dentry);
 545         return 0;
 546 }
 547
 548 static void
 549 init_pipe(struct rpc_pipe *pipe)
 550 {
 551         pipe->nreaders = 0;
 552         pipe->nwriters = 0;
 553         INIT_LIST_HEAD(&pipe->in_upcall);
 554         INIT_LIST_HEAD(&pipe->in_downcall);
 555         INIT_LIST_HEAD(&pipe->pipe);
 556         pipe->pipelen = 0;
 557         INIT_DELAYED_WORK(&pipe->queue_timeout,
 558                             rpc_timeout_upcall_queue);
 559         pipe->ops = NULL;
 560         spin_lock_init(&pipe->lock);
 561         pipe->dentry = NULL;
 562 }
 563
 564 void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
 565 {
 566         kfree(pipe);
 567 }
 568 EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
 569
 570 struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
 571 {
 572         struct rpc_pipe *pipe;
 573
 574         pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
 575         if (!pipe)
 576                 return ERR_PTR(-ENOMEM);
 577         init_pipe(pipe);
 578         pipe->ops = ops;
 579         pipe->flags = flags;
 580         return pipe;
 581 }
 582 EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
 583
 584 static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
 585                                umode_t mode,
 586                                const struct file_operations *i_fop,
 587                                void *private,
 588                                struct rpc_pipe *pipe)
 589 {
 590         struct rpc_inode *rpci;
 591         int err;
 592
 593         err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
 594         if (err)
 595                 return err;
 596         rpci = RPC_I(dentry->d_inode);
 597         rpci->private = private;
 598         rpci->pipe = pipe;
 599         fsnotify_create(dir, dentry);
 600         return 0;
 601 }
 602
 603 static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 604 {
 605         int ret;
 606
 607         dget(dentry);
 608         ret = simple_rmdir(dir, dentry);
 609         d_delete(dentry);
 610         dput(dentry);
 611         return ret;
 612 }
 613
 614 int rpc_rmdir(struct dentry *dentry)
 615 {
 616         struct dentry *parent;
 617         struct inode *dir;
 618         int error;
 619
 620         parent = dget_parent(dentry);
 621         dir = parent->d_inode;
 622         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 623         error = __rpc_rmdir(dir, dentry);
 624         mutex_unlock(&dir->i_mutex);
 625         dput(parent);
 626         return error;
 627 }
 628 EXPORT_SYMBOL_GPL(rpc_rmdir);
 629
 630 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
 631 {
 632         int ret;
 633
 634         dget(dentry);
 635         ret = simple_unlink(dir, dentry);
 636         d_delete(dentry);
 637         dput(dentry);
 638         return ret;
 639 }
 640
 641 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
 642 {
 643         struct inode *inode = dentry->d_inode;
 644
 645         rpc_close_pipes(inode);
 646         return __rpc_unlink(dir, dentry);
 647 }
 648
 649 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
 650                                           const char *name)
 651 {
 652         struct qstr q = QSTR_INIT(name, strlen(name));
 653         struct dentry *dentry = d_hash_and_lookup(parent, &q);
 654         if (!dentry) {
 655                 dentry = d_alloc(parent, &q);
 656                 if (!dentry)
 657                         return ERR_PTR(-ENOMEM);
 658         }
 659         if (dentry->d_inode == NULL)
 660                 return dentry;
 661         dput(dentry);
 662         return ERR_PTR(-EEXIST);
 663 }
 664
 665 /*
 666  * FIXME: This probably has races.
 667  */
 668 static void __rpc_depopulate(struct dentry *parent,
 669                              const struct rpc_filelist *files,
 670                              int start, int eof)
 671 {
 672         struct inode *dir = parent->d_inode;
 673         struct dentry *dentry;
 674         struct qstr name;
 675         int i;
 676
 677         for (i = start; i < eof; i++) {
 678                 name.name = files[i].name;
 679                 name.len = strlen(files[i].name);
 680                 dentry = d_hash_and_lookup(parent, &name);
 681
 682                 if (dentry == NULL)
 683                         continue;
 684                 if (dentry->d_inode == NULL)
 685                         goto next;
 686                 switch (dentry->d_inode->i_mode & S_IFMT) {
 687                         default:
 688                                 BUG();
 689                         case S_IFREG:
 690                                 __rpc_unlink(dir, dentry);
 691                                 break;
 692                         case S_IFDIR:
 693                                 __rpc_rmdir(dir, dentry);
 694                 }
 695 next:
 696                 dput(dentry);
 697         }
 698 }
 699
 700 static void rpc_depopulate(struct dentry *parent,
 701                            const struct rpc_filelist *files,
 702                            int start, int eof)
 703 {
 704         struct inode *dir = parent->d_inode;
 705
 706         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
 707         __rpc_depopulate(parent, files, start, eof);
 708         mutex_unlock(&dir->i_mutex);
 709 }
 710
 711 static int rpc_populate(struct dentry *parent,
 712                         const struct rpc_filelist *files,
 713                         int start, int eof,
 714                         void *private)
 715 {
 716         struct inode *dir = parent->d_inode;
 717         struct dentry *dentry;
 718         int i, err;
 719
 720         mutex_lock(&dir->i_mutex);
 721         for (i = start; i < eof; i++) {
 722                 dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
 723                 err = PTR_ERR(dentry);
 724                 if (IS_ERR(dentry))
 725                         goto out_bad;
 726                 switch (files[i].mode & S_IFMT) {
 727                         default:
 728                                 BUG();
 729                         case S_IFREG:
 730                                 err = __rpc_create(dir, dentry,
 731                                                 files[i].mode,
 732                                                 files[i].i_fop,
 733                                                 private);
 734                                 break;
 735                         case S_IFDIR:
 736                                 err = __rpc_mkdir(dir, dentry,
 737                                                 files[i].mode,
 738                                                 NULL,
 739                                                 private);
 740                 }
 741                 if (err != 0)
 742                         goto out_bad;
 743         }
 744         mutex_unlock(&dir->i_mutex);
 745         return 0;
 746 out_bad:
 747         __rpc_depopulate(parent, files, start, eof);
 748         mutex_unlock(&dir->i_mutex);
 749         printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
 750                         __FILE__, __func__, parent);
 751         return err;
 752 }
 753
 754 static struct dentry *rpc_mkdir_populate(struct dentry *parent,
 755                 const char *name, umode_t mode, void *private,
 756                 int (*populate)(struct dentry *, void *), void *args_populate)
 757 {
 758         struct dentry *dentry;
 759         struct inode *dir = parent->d_inode;
 760         int error;
 761
 762         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 763         dentry = __rpc_lookup_create_exclusive(parent, name);
 764         if (IS_ERR(dentry))
 765                 goto out;
 766         error = __rpc_mkdir(dir, dentry, mode, NULL, private);
 767         if (error != 0)
 768                 goto out_err;
 769         if (populate != NULL) {
 770                 error = populate(dentry, args_populate);
 771                 if (error)
 772                         goto err_rmdir;
 773         }
 774 out:
 775         mutex_unlock(&dir->i_mutex);
 776         return dentry;
 777 err_rmdir:
 778         __rpc_rmdir(dir, dentry);
 779 out_err:
 780         dentry = ERR_PTR(error);
 781         goto out;
 782 }
 783
 784 static int rpc_rmdir_depopulate(struct dentry *dentry,
 785                 void (*depopulate)(struct dentry *))
 786 {
 787         struct dentry *parent;
 788         struct inode *dir;
 789         int error;
 790
 791         parent = dget_parent(dentry);
 792         dir = parent->d_inode;
 793         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 794         if (depopulate != NULL)
 795                 depopulate(dentry);
 796         error = __rpc_rmdir(dir, dentry);
 797         mutex_unlock(&dir->i_mutex);
 798         dput(parent);
 799         return error;
 800 }
 801
 802 /**
 803  * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
 804  * @parent: dentry of directory to create new "pipe" in
 805  * @name: name of pipe
 806  * @private: private data to associate with the pipe, for the caller's use
 807  * @pipe: &rpc_pipe containing input parameters
 808  *
 809  * Data is made available for userspace to read by calls to
 810  * rpc_queue_upcall().  The actual reads will result in calls to
 811  * @ops->upcall, which will be called with the file pointer,
 812  * message, and userspace buffer to copy to.
 813  *
 814  * Writes can come at any time, and do not necessarily have to be
 815  * responses to upcalls.  They will result in calls to @msg->downcall.
 816  *
 817  * The @private argument passed here will be available to all these methods
 818  * from the file pointer, via RPC_I(file_inode(file))->private.
 819  */
 820 struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
 821                                  void *private, struct rpc_pipe *pipe)
 822 {
 823         struct dentry *dentry;
 824         struct inode *dir = parent->d_inode;
 825         umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
 826         int err;
 827
 828         if (pipe->ops->upcall == NULL)
 829                 umode &= ~S_IRUGO;
 830         if (pipe->ops->downcall == NULL)
 831                 umode &= ~S_IWUGO;
 832
 833         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 834         dentry = __rpc_lookup_create_exclusive(parent, name);
 835         if (IS_ERR(dentry))
 836                 goto out;
 837         err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
 838                                   private, pipe);
 839         if (err)
 840                 goto out_err;
 841 out:
 842         mutex_unlock(&dir->i_mutex);
 843         return dentry;
 844 out_err:
 845         dentry = ERR_PTR(err);
 846         printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n",
 847                         __FILE__, __func__, parent, name,
 848                         err);
 849         goto out;
 850 }
 851 EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
 852
 853 /**
 854  * rpc_unlink - remove a pipe
 855  * @dentry: dentry for the pipe, as returned from rpc_mkpipe
 856  *
 857  * After this call, lookups will no longer find the pipe, and any
 858  * attempts to read or write using preexisting opens of the pipe will
 859  * return -EPIPE.
 860  */
 861 int
 862 rpc_unlink(struct dentry *dentry)
 863 {
 864         struct dentry *parent;
 865         struct inode *dir;
 866         int error = 0;
 867
 868         parent = dget_parent(dentry);
 869         dir = parent->d_inode;
 870         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 871         error = __rpc_rmpipe(dir, dentry);
 872         mutex_unlock(&dir->i_mutex);
 873         dput(parent);
 874         return error;
 875 }
 876 EXPORT_SYMBOL_GPL(rpc_unlink);
 877
 878 /**
 879  * rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head
 880  * @pdh: pointer to struct rpc_pipe_dir_head
 881  */
 882 void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh)
 883 {
 884         INIT_LIST_HEAD(&pdh->pdh_entries);
 885         pdh->pdh_dentry = NULL;
 886 }
 887 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head);
 888
 889 /**
 890  * rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object
 891  * @pdo: pointer to struct rpc_pipe_dir_object
 892  * @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops
 893  * @pdo_data: pointer to caller-defined data
 894  */
 895 void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
 896                 const struct rpc_pipe_dir_object_ops *pdo_ops,
 897                 void *pdo_data)
 898 {
 899         INIT_LIST_HEAD(&pdo->pdo_head);
 900         pdo->pdo_ops = pdo_ops;
 901         pdo->pdo_data = pdo_data;
 902 }
 903 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
 904
 905 static int
 906 rpc_add_pipe_dir_object_locked(struct net *net,
 907                 struct rpc_pipe_dir_head *pdh,
 908                 struct rpc_pipe_dir_object *pdo)
 909 {
 910         int ret = 0;
 911
 912         if (pdh->pdh_dentry)
 913                 ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo);
 914         if (ret == 0)
 915                 list_add_tail(&pdo->pdo_head, &pdh->pdh_entries);
 916         return ret;
 917 }
 918
 919 static void
 920 rpc_remove_pipe_dir_object_locked(struct net *net,
 921                 struct rpc_pipe_dir_head *pdh,
 922                 struct rpc_pipe_dir_object *pdo)
 923 {
 924         if (pdh->pdh_dentry)
 925                 pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo);
 926         list_del_init(&pdo->pdo_head);
 927 }
 928
 929 /**
 930  * rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory
 931  * @net: pointer to struct net
 932  * @pdh: pointer to struct rpc_pipe_dir_head
 933  * @pdo: pointer to struct rpc_pipe_dir_object
 934  *
 935  */
 936 int
 937 rpc_add_pipe_dir_object(struct net *net,
 938                 struct rpc_pipe_dir_head *pdh,
 939                 struct rpc_pipe_dir_object *pdo)
 940 {
 941         int ret = 0;
 942
 943         if (list_empty(&pdo->pdo_head)) {
 944                 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 945
 946                 mutex_lock(&sn->pipefs_sb_lock);
 947                 ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo);
 948                 mutex_unlock(&sn->pipefs_sb_lock);
 949         }
 950         return ret;
 951 }
 952 EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object);
 953
 954 /**
 955  * rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory
 956  * @net: pointer to struct net
 957  * @pdh: pointer to struct rpc_pipe_dir_head
 958  * @pdo: pointer to struct rpc_pipe_dir_object
 959  *
 960  */
 961 void
 962 rpc_remove_pipe_dir_object(struct net *net,
 963                 struct rpc_pipe_dir_head *pdh,
 964                 struct rpc_pipe_dir_object *pdo)
 965 {
 966         if (!list_empty(&pdo->pdo_head)) {
 967                 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 968
 969                 mutex_lock(&sn->pipefs_sb_lock);
 970                 rpc_remove_pipe_dir_object_locked(net, pdh, pdo);
 971                 mutex_unlock(&sn->pipefs_sb_lock);
 972         }
 973 }
 974 EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
 975
 976 /**
 977  * rpc_find_or_alloc_pipe_dir_object
 978  * @net: pointer to struct net
 979  * @pdh: pointer to struct rpc_pipe_dir_head
 980  * @match: match struct rpc_pipe_dir_object to data
 981  * @alloc: allocate a new struct rpc_pipe_dir_object
 982  * @data: user defined data for match() and alloc()
 983  *
 984  */
 985 struct rpc_pipe_dir_object *
 986 rpc_find_or_alloc_pipe_dir_object(struct net *net,
 987                 struct rpc_pipe_dir_head *pdh,
 988                 int (*match)(struct rpc_pipe_dir_object *, void *),
 989                 struct rpc_pipe_dir_object *(*alloc)(void *),
 990                 void *data)
 991 {
 992         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 993         struct rpc_pipe_dir_object *pdo;
 994
 995         mutex_lock(&sn->pipefs_sb_lock);
 996         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
 997                 if (!match(pdo, data))
 998                         continue;
 999                 goto out;
1000         }
1001         pdo = alloc(data);
1002         if (!pdo)
1003                 goto out;
1004         rpc_add_pipe_dir_object_locked(net, pdh, pdo);
1005 out:
1006         mutex_unlock(&sn->pipefs_sb_lock);
1007         return pdo;
1008 }
1009 EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
1010
1011 static void
1012 rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
1013 {
1014         struct rpc_pipe_dir_object *pdo;
1015         struct dentry *dir = pdh->pdh_dentry;
1016
1017         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1018                 pdo->pdo_ops->create(dir, pdo);
1019 }
1020
1021 static void
1022 rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
1023 {
1024         struct rpc_pipe_dir_object *pdo;
1025         struct dentry *dir = pdh->pdh_dentry;
1026
1027         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1028                 pdo->pdo_ops->destroy(dir, pdo);
1029 }
1030
1031 enum {
1032         RPCAUTH_info,
1033         RPCAUTH_EOF
1034 };
1035
1036 static const struct rpc_filelist authfiles[] = {
1037         [RPCAUTH_info] = {
1038                 .name = "info",
1039                 .i_fop = &rpc_info_operations,
1040                 .mode = S_IFREG | S_IRUSR,
1041         },
1042 };
1043
1044 static int rpc_clntdir_populate(struct dentry *dentry, void *private)
1045 {
1046         return rpc_populate(dentry,
1047                             authfiles, RPCAUTH_info, RPCAUTH_EOF,
1048                             private);
1049 }
1050
1051 static void rpc_clntdir_depopulate(struct dentry *dentry)
1052 {
1053         rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
1054 }
1055
1056 /**
1057  * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
1058  * @dentry: the parent of new directory
1059  * @name: the name of new directory
1060  * @rpc_client: rpc client to associate with this directory
1061  *
1062  * This creates a directory at the given @path associated with
1063  * @rpc_clnt, which will contain a file named "info" with some basic
1064  * information about the client, together with any "pipes" that may
1065  * later be created using rpc_mkpipe().
1066  */
1067 struct dentry *rpc_create_client_dir(struct dentry *dentry,
1068                                    const char *name,
1069                                    struct rpc_clnt *rpc_client)
1070 {
1071         struct dentry *ret;
1072
1073         ret = rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
1074                         rpc_clntdir_populate, rpc_client);
1075         if (!IS_ERR(ret)) {
1076                 rpc_client->cl_pipedir_objects.pdh_dentry = ret;
1077                 rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1078         }
1079         return ret;
1080 }
1081
1082 /**
1083  * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
1084  * @rpc_client: rpc_client for the pipe
1085  */
1086 int rpc_remove_client_dir(struct rpc_clnt *rpc_client)
1087 {
1088         struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry;
1089
1090         if (dentry == NULL)
1091                 return 0;
1092         rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1093         rpc_client->cl_pipedir_objects.pdh_dentry = NULL;
1094         return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
1095 }
1096
1097 static const struct rpc_filelist cache_pipefs_files[3] = {
1098         [0] = {
1099                 .name = "channel",
1100                 .i_fop = &cache_file_operations_pipefs,
1101                 .mode = S_IFREG|S_IRUSR|S_IWUSR,
1102         },
1103         [1] = {
1104                 .name = "content",
1105                 .i_fop = &content_file_operations_pipefs,
1106                 .mode = S_IFREG|S_IRUSR,
1107         },
1108         [2] = {
1109                 .name = "flush",
1110                 .i_fop = &cache_flush_operations_pipefs,
1111                 .mode = S_IFREG|S_IRUSR|S_IWUSR,
1112         },
1113 };
1114
1115 static int rpc_cachedir_populate(struct dentry *dentry, void *private)
1116 {
1117         return rpc_populate(dentry,
1118                             cache_pipefs_files, 0, 3,
1119                             private);
1120 }
1121
1122 static void rpc_cachedir_depopulate(struct dentry *dentry)
1123 {
1124         rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
1125 }
1126
1127 struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
1128                                     umode_t umode, struct cache_detail *cd)
1129 {
1130         return rpc_mkdir_populate(parent, name, umode, NULL,
1131                         rpc_cachedir_populate, cd);
1132 }
1133
1134 void rpc_remove_cache_dir(struct dentry *dentry)
1135 {
1136         rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
1137 }
1138
1139 /*
1140  * populate the filesystem
1141  */
1142 static const struct super_operations s_ops = {
1143         .alloc_inode    = rpc_alloc_inode,
1144         .destroy_inode  = rpc_destroy_inode,
1145         .statfs         = simple_statfs,
1146 };
1147
1148 #define RPCAUTH_GSSMAGIC 0x67596969
1149
1150 /*
1151  * We have a single directory with 1 node in it.
1152  */
1153 enum {
1154         RPCAUTH_lockd,
1155         RPCAUTH_mount,
1156         RPCAUTH_nfs,
1157         RPCAUTH_portmap,
1158         RPCAUTH_statd,
1159         RPCAUTH_nfsd4_cb,
1160         RPCAUTH_cache,
1161         RPCAUTH_nfsd,
1162         RPCAUTH_RootEOF
1163 };
1164
1165 static const struct rpc_filelist files[] = {
1166         [RPCAUTH_lockd] = {
1167                 .name = "lockd",
1168                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1169         },
1170         [RPCAUTH_mount] = {
1171                 .name = "mount",
1172                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1173         },
1174         [RPCAUTH_nfs] = {
1175                 .name = "nfs",
1176                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1177         },
1178         [RPCAUTH_portmap] = {
1179                 .name = "portmap",
1180                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1181         },
1182         [RPCAUTH_statd] = {
1183                 .name = "statd",
1184                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1185         },
1186         [RPCAUTH_nfsd4_cb] = {
1187                 .name = "nfsd4_cb",
1188                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1189         },
1190         [RPCAUTH_cache] = {
1191                 .name = "cache",
1192                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1193         },
1194         [RPCAUTH_nfsd] = {
1195                 .name = "nfsd",
1196                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1197         },
1198 };
1199
1200 /*
1201  * This call can be used only in RPC pipefs mount notification hooks.
1202  */
1203 struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1204                                const unsigned char *dir_name)
1205 {
1206         struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
1207         return d_hash_and_lookup(sb->s_root, &dir);
1208 }
1209 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1210
1211 void rpc_pipefs_init_net(struct net *net)
1212 {
1213         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1214
1215         mutex_init(&sn->pipefs_sb_lock);
1216         sn->gssd_running = 1;
1217         sn->pipe_version = -1;
1218 }
1219
1220 /*
1221  * This call will be used for per network namespace operations calls.
1222  * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1223  * found. This lock have to be released by rpc_put_sb_net() when all operations
1224  * will be completed.
1225  */
1226 struct super_block *rpc_get_sb_net(const struct net *net)
1227 {
1228         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1229
1230         mutex_lock(&sn->pipefs_sb_lock);
1231         if (sn->pipefs_sb)
1232                 return sn->pipefs_sb;
1233         mutex_unlock(&sn->pipefs_sb_lock);
1234         return NULL;
1235 }
1236 EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1237
1238 void rpc_put_sb_net(const struct net *net)
1239 {
1240         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1241
1242         WARN_ON(sn->pipefs_sb == NULL);
1243         mutex_unlock(&sn->pipefs_sb_lock);
1244 }
1245 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1246
1247 static int
1248 rpc_fill_super(struct super_block *sb, void *data, int silent)
1249 {
1250         struct inode *inode;
1251         struct dentry *root;
1252         struct net *net = data;
1253         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1254         int err;
1255
1256         sb->s_blocksize = PAGE_CACHE_SIZE;
1257         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1258         sb->s_magic = RPCAUTH_GSSMAGIC;
1259         sb->s_op = &s_ops;
1260         sb->s_d_op = &simple_dentry_operations;
1261         sb->s_time_gran = 1;
1262
1263         inode = rpc_get_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1264         sb->s_root = root = d_make_root(inode);
1265         if (!root)
1266                 return -ENOMEM;
1267         if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1268                 return -ENOMEM;
1269         dprintk("RPC:       sending pipefs MOUNT notification for net %p%s\n",
1270                 net, NET_NAME(net));
1271         mutex_lock(&sn->pipefs_sb_lock);
1272         sn->pipefs_sb = sb;
1273         err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1274                                            RPC_PIPEFS_MOUNT,
1275                                            sb);
1276         if (err)
1277                 goto err_depopulate;
1278         sb->s_fs_info = get_net(net);
1279         mutex_unlock(&sn->pipefs_sb_lock);
1280         return 0;
1281
1282 err_depopulate:
1283         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1284                                            RPC_PIPEFS_UMOUNT,
1285                                            sb);
1286         sn->pipefs_sb = NULL;
1287         __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1288         mutex_unlock(&sn->pipefs_sb_lock);
1289         return err;
1290 }
1291
1292 static struct dentry *
1293 rpc_mount(struct file_system_type *fs_type,
1294                 int flags, const char *dev_name, void *data)
1295 {
1296         return mount_ns(fs_type, flags, current->nsproxy->net_ns, rpc_fill_super);
1297 }
1298
1299 static void rpc_kill_sb(struct super_block *sb)
1300 {
1301         struct net *net = sb->s_fs_info;
1302         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1303
1304         mutex_lock(&sn->pipefs_sb_lock);
1305         if (sn->pipefs_sb != sb) {
1306                 mutex_unlock(&sn->pipefs_sb_lock);
1307                 goto out;
1308         }
1309         sn->pipefs_sb = NULL;
1310         dprintk("RPC:       sending pipefs UMOUNT notification for net %p%s\n",
1311                 net, NET_NAME(net));
1312         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1313                                            RPC_PIPEFS_UMOUNT,
1314                                            sb);
1315         mutex_unlock(&sn->pipefs_sb_lock);
1316         put_net(net);
1317 out:
1318         kill_litter_super(sb);
1319 }
1320
1321 static struct file_system_type rpc_pipe_fs_type = {
1322         .owner          = THIS_MODULE,
1323         .name           = "rpc_pipefs",
1324         .mount          = rpc_mount,
1325         .kill_sb        = rpc_kill_sb,
1326 };
1327 MODULE_ALIAS_FS("rpc_pipefs");
1328 MODULE_ALIAS("rpc_pipefs");
1329
1330 static void
1331 init_once(void *foo)
1332 {
1333         struct rpc_inode *rpci = (struct rpc_inode *) foo;
1334
1335         inode_init_once(&rpci->vfs_inode);
1336         rpci->private = NULL;
1337         rpci->pipe = NULL;
1338         init_waitqueue_head(&rpci->waitq);
1339 }
1340
1341 int register_rpc_pipefs(void)
1342 {
1343         int err;
1344
1345         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1346                                 sizeof(struct rpc_inode),
1347                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1348                                                 SLAB_MEM_SPREAD),
1349                                 init_once);
1350         if (!rpc_inode_cachep)
1351                 return -ENOMEM;
1352         err = rpc_clients_notifier_register();
1353         if (err)
1354                 goto err_notifier;
1355         err = register_filesystem(&rpc_pipe_fs_type);
1356         if (err)
1357                 goto err_register;
1358         return 0;
1359
1360 err_register:
1361         rpc_clients_notifier_unregister();
1362 err_notifier:
1363         kmem_cache_destroy(rpc_inode_cachep);
1364         return err;
1365 }
1366
1367 void unregister_rpc_pipefs(void)
1368 {
1369         rpc_clients_notifier_unregister();
1370         kmem_cache_destroy(rpc_inode_cachep);
1371         unregister_filesystem(&rpc_pipe_fs_type);
1372 }