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 #include <linux/utsname.h>
  21
  22 #include <asm/ioctls.h>
  23 #include <linux/poll.h>
  24 #include <linux/wait.h>
  25 #include <linux/seq_file.h>
  26
  27 #include <linux/sunrpc/clnt.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/sunrpc/rpc_pipe_fs.h>
  30 #include <linux/sunrpc/cache.h>
  31 #include <linux/nsproxy.h>
  32 #include <linux/notifier.h>
  33
  34 #include "netns.h"
  35 #include "sunrpc.h"
  36
  37 #define RPCDBG_FACILITY RPCDBG_DEBUG
  38
  39 #define NET_NAME(net)   ((net == &init_net) ? " (init_net)" : "")
  40
  41 static struct file_system_type rpc_pipe_fs_type;
  42 static const struct rpc_pipe_ops gssd_dummy_pipe_ops;
  43
  44 static struct kmem_cache *rpc_inode_cachep __read_mostly;
  45
  46 #define RPC_UPCALL_TIMEOUT (30*HZ)
  47
  48 static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
  49
  50 int rpc_pipefs_notifier_register(struct notifier_block *nb)
  51 {
  52         return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
  53 }
  54 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
  55
  56 void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
  57 {
  58         blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
  59 }
  60 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
  61
  62 static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head,
  63                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
  64 {
  65         struct rpc_pipe_msg *msg;
  66
  67         if (list_empty(head))
  68                 return;
  69         do {
  70                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
  71                 list_del_init(&msg->list);
  72                 msg->errno = err;
  73                 destroy_msg(msg);
  74         } while (!list_empty(head));
  75
  76         if (waitq)
  77                 wake_up(waitq);
  78 }
  79
  80 static void
  81 rpc_timeout_upcall_queue(struct work_struct *work)
  82 {
  83         LIST_HEAD(free_list);
  84         struct rpc_pipe *pipe =
  85                 container_of(work, struct rpc_pipe, queue_timeout.work);
  86         void (*destroy_msg)(struct rpc_pipe_msg *);
  87         struct dentry *dentry;
  88
  89         spin_lock(&pipe->lock);
  90         destroy_msg = pipe->ops->destroy_msg;
  91         if (pipe->nreaders == 0) {
  92                 list_splice_init(&pipe->pipe, &free_list);
  93                 pipe->pipelen = 0;
  94         }
  95         dentry = dget(pipe->dentry);
  96         spin_unlock(&pipe->lock);
  97         rpc_purge_list(dentry ? &RPC_I(d_inode(dentry))->waitq : NULL,
  98                         &free_list, destroy_msg, -ETIMEDOUT);
  99         dput(dentry);
 100 }
 101
 102 ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 103                                 char __user *dst, size_t buflen)
 104 {
 105         char *data = (char *)msg->data + msg->copied;
 106         size_t mlen = min(msg->len - msg->copied, buflen);
 107         unsigned long left;
 108
 109         left = copy_to_user(dst, data, mlen);
 110         if (left == mlen) {
 111                 msg->errno = -EFAULT;
 112                 return -EFAULT;
 113         }
 114
 115         mlen -= left;
 116         msg->copied += mlen;
 117         msg->errno = 0;
 118         return mlen;
 119 }
 120 EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
 121
 122 /**
 123  * rpc_queue_upcall - queue an upcall message to userspace
 124  * @pipe: upcall pipe on which to queue given message
 125  * @msg: message to queue
 126  *
 127  * Call with an @inode created by rpc_mkpipe() to queue an upcall.
 128  * A userspace process may then later read the upcall by performing a
 129  * read on an open file for this inode.  It is up to the caller to
 130  * initialize the fields of @msg (other than @msg->list) appropriately.
 131  */
 132 int
 133 rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
 134 {
 135         int res = -EPIPE;
 136         struct dentry *dentry;
 137
 138         spin_lock(&pipe->lock);
 139         if (pipe->nreaders) {
 140                 list_add_tail(&msg->list, &pipe->pipe);
 141                 pipe->pipelen += msg->len;
 142                 res = 0;
 143         } else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
 144                 if (list_empty(&pipe->pipe))
 145                         queue_delayed_work(rpciod_workqueue,
 146                                         &pipe->queue_timeout,
 147                                         RPC_UPCALL_TIMEOUT);
 148                 list_add_tail(&msg->list, &pipe->pipe);
 149                 pipe->pipelen += msg->len;
 150                 res = 0;
 151         }
 152         dentry = dget(pipe->dentry);
 153         spin_unlock(&pipe->lock);
 154         if (dentry) {
 155                 wake_up(&RPC_I(d_inode(dentry))->waitq);
 156                 dput(dentry);
 157         }
 158         return res;
 159 }
 160 EXPORT_SYMBOL_GPL(rpc_queue_upcall);
 161
 162 static inline void
 163 rpc_inode_setowner(struct inode *inode, void *private)
 164 {
 165         RPC_I(inode)->private = private;
 166 }
 167
 168 static void
 169 rpc_close_pipes(struct inode *inode)
 170 {
 171         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 172         int need_release;
 173         LIST_HEAD(free_list);
 174
 175         inode_lock(inode);
 176         spin_lock(&pipe->lock);
 177         need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
 178         pipe->nreaders = 0;
 179         list_splice_init(&pipe->in_upcall, &free_list);
 180         list_splice_init(&pipe->pipe, &free_list);
 181         pipe->pipelen = 0;
 182         pipe->dentry = NULL;
 183         spin_unlock(&pipe->lock);
 184         rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
 185         pipe->nwriters = 0;
 186         if (need_release && pipe->ops->release_pipe)
 187                 pipe->ops->release_pipe(inode);
 188         cancel_delayed_work_sync(&pipe->queue_timeout);
 189         rpc_inode_setowner(inode, NULL);
 190         RPC_I(inode)->pipe = NULL;
 191         inode_unlock(inode);
 192 }
 193
 194 static struct inode *
 195 rpc_alloc_inode(struct super_block *sb)
 196 {
 197         struct rpc_inode *rpci;
 198         rpci = kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
 199         if (!rpci)
 200                 return NULL;
 201         return &rpci->vfs_inode;
 202 }
 203
 204 static void
 205 rpc_i_callback(struct rcu_head *head)
 206 {
 207         struct inode *inode = container_of(head, struct inode, i_rcu);
 208         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 209 }
 210
 211 static void
 212 rpc_destroy_inode(struct inode *inode)
 213 {
 214         call_rcu(&inode->i_rcu, rpc_i_callback);
 215 }
 216
 217 static int
 218 rpc_pipe_open(struct inode *inode, struct file *filp)
 219 {
 220         struct rpc_pipe *pipe;
 221         int first_open;
 222         int res = -ENXIO;
 223
 224         inode_lock(inode);
 225         pipe = RPC_I(inode)->pipe;
 226         if (pipe == NULL)
 227                 goto out;
 228         first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
 229         if (first_open && pipe->ops->open_pipe) {
 230                 res = pipe->ops->open_pipe(inode);
 231                 if (res)
 232                         goto out;
 233         }
 234         if (filp->f_mode & FMODE_READ)
 235                 pipe->nreaders++;
 236         if (filp->f_mode & FMODE_WRITE)
 237                 pipe->nwriters++;
 238         res = 0;
 239 out:
 240         inode_unlock(inode);
 241         return res;
 242 }
 243
 244 static int
 245 rpc_pipe_release(struct inode *inode, struct file *filp)
 246 {
 247         struct rpc_pipe *pipe;
 248         struct rpc_pipe_msg *msg;
 249         int last_close;
 250
 251         inode_lock(inode);
 252         pipe = RPC_I(inode)->pipe;
 253         if (pipe == NULL)
 254                 goto out;
 255         msg = filp->private_data;
 256         if (msg != NULL) {
 257                 spin_lock(&pipe->lock);
 258                 msg->errno = -EAGAIN;
 259                 list_del_init(&msg->list);
 260                 spin_unlock(&pipe->lock);
 261                 pipe->ops->destroy_msg(msg);
 262         }
 263         if (filp->f_mode & FMODE_WRITE)
 264                 pipe->nwriters --;
 265         if (filp->f_mode & FMODE_READ) {
 266                 pipe->nreaders --;
 267                 if (pipe->nreaders == 0) {
 268                         LIST_HEAD(free_list);
 269                         spin_lock(&pipe->lock);
 270                         list_splice_init(&pipe->pipe, &free_list);
 271                         pipe->pipelen = 0;
 272                         spin_unlock(&pipe->lock);
 273                         rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
 274                                         pipe->ops->destroy_msg, -EAGAIN);
 275                 }
 276         }
 277         last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
 278         if (last_close && pipe->ops->release_pipe)
 279                 pipe->ops->release_pipe(inode);
 280 out:
 281         inode_unlock(inode);
 282         return 0;
 283 }
 284
 285 static ssize_t
 286 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 287 {
 288         struct inode *inode = file_inode(filp);
 289         struct rpc_pipe *pipe;
 290         struct rpc_pipe_msg *msg;
 291         int res = 0;
 292
 293         inode_lock(inode);
 294         pipe = RPC_I(inode)->pipe;
 295         if (pipe == NULL) {
 296                 res = -EPIPE;
 297                 goto out_unlock;
 298         }
 299         msg = filp->private_data;
 300         if (msg == NULL) {
 301                 spin_lock(&pipe->lock);
 302                 if (!list_empty(&pipe->pipe)) {
 303                         msg = list_entry(pipe->pipe.next,
 304                                         struct rpc_pipe_msg,
 305                                         list);
 306                         list_move(&msg->list, &pipe->in_upcall);
 307                         pipe->pipelen -= msg->len;
 308                         filp->private_data = msg;
 309                         msg->copied = 0;
 310                 }
 311                 spin_unlock(&pipe->lock);
 312                 if (msg == NULL)
 313                         goto out_unlock;
 314         }
 315         /* NOTE: it is up to the callback to update msg->copied */
 316         res = pipe->ops->upcall(filp, msg, buf, len);
 317         if (res < 0 || msg->len == msg->copied) {
 318                 filp->private_data = NULL;
 319                 spin_lock(&pipe->lock);
 320                 list_del_init(&msg->list);
 321                 spin_unlock(&pipe->lock);
 322                 pipe->ops->destroy_msg(msg);
 323         }
 324 out_unlock:
 325         inode_unlock(inode);
 326         return res;
 327 }
 328
 329 static ssize_t
 330 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 331 {
 332         struct inode *inode = file_inode(filp);
 333         int res;
 334
 335         inode_lock(inode);
 336         res = -EPIPE;
 337         if (RPC_I(inode)->pipe != NULL)
 338                 res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
 339         inode_unlock(inode);
 340         return res;
 341 }
 342
 343 static __poll_t
 344 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 345 {
 346         struct inode *inode = file_inode(filp);
 347         struct rpc_inode *rpci = RPC_I(inode);
 348         __poll_t mask = EPOLLOUT | EPOLLWRNORM;
 349
 350         poll_wait(filp, &rpci->waitq, wait);
 351
 352         inode_lock(inode);
 353         if (rpci->pipe == NULL)
 354                 mask |= EPOLLERR | EPOLLHUP;
 355         else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
 356                 mask |= EPOLLIN | EPOLLRDNORM;
 357         inode_unlock(inode);
 358         return mask;
 359 }
 360
 361 static long
 362 rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 363 {
 364         struct inode *inode = file_inode(filp);
 365         struct rpc_pipe *pipe;
 366         int len;
 367
 368         switch (cmd) {
 369         case FIONREAD:
 370                 inode_lock(inode);
 371                 pipe = RPC_I(inode)->pipe;
 372                 if (pipe == NULL) {
 373                         inode_unlock(inode);
 374                         return -EPIPE;
 375                 }
 376                 spin_lock(&pipe->lock);
 377                 len = pipe->pipelen;
 378                 if (filp->private_data) {
 379                         struct rpc_pipe_msg *msg;
 380                         msg = filp->private_data;
 381                         len += msg->len - msg->copied;
 382                 }
 383                 spin_unlock(&pipe->lock);
 384                 inode_unlock(inode);
 385                 return put_user(len, (int __user *)arg);
 386         default:
 387                 return -EINVAL;
 388         }
 389 }
 390
 391 static const struct file_operations rpc_pipe_fops = {
 392         .owner          = THIS_MODULE,
 393         .llseek         = no_llseek,
 394         .read           = rpc_pipe_read,
 395         .write          = rpc_pipe_write,
 396         .poll           = rpc_pipe_poll,
 397         .unlocked_ioctl = rpc_pipe_ioctl,
 398         .open           = rpc_pipe_open,
 399         .release        = rpc_pipe_release,
 400 };
 401
 402 static int
 403 rpc_show_info(struct seq_file *m, void *v)
 404 {
 405         struct rpc_clnt *clnt = m->private;
 406
 407         rcu_read_lock();
 408         seq_printf(m, "RPC server: %s\n",
 409                         rcu_dereference(clnt->cl_xprt)->servername);
 410         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_program->name,
 411                         clnt->cl_prog, clnt->cl_vers);
 412         seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
 413         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
 414         seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
 415         rcu_read_unlock();
 416         return 0;
 417 }
 418
 419 static int
 420 rpc_info_open(struct inode *inode, struct file *file)
 421 {
 422         struct rpc_clnt *clnt = NULL;
 423         int ret = single_open(file, rpc_show_info, NULL);
 424
 425         if (!ret) {
 426                 struct seq_file *m = file->private_data;
 427
 428                 spin_lock(&file->f_path.dentry->d_lock);
 429                 if (!d_unhashed(file->f_path.dentry))
 430                         clnt = RPC_I(inode)->private;
 431                 if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
 432                         spin_unlock(&file->f_path.dentry->d_lock);
 433                         m->private = clnt;
 434                 } else {
 435                         spin_unlock(&file->f_path.dentry->d_lock);
 436                         single_release(inode, file);
 437                         ret = -EINVAL;
 438                 }
 439         }
 440         return ret;
 441 }
 442
 443 static int
 444 rpc_info_release(struct inode *inode, struct file *file)
 445 {
 446         struct seq_file *m = file->private_data;
 447         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
 448
 449         if (clnt)
 450                 rpc_release_client(clnt);
 451         return single_release(inode, file);
 452 }
 453
 454 static const struct file_operations rpc_info_operations = {
 455         .owner          = THIS_MODULE,
 456         .open           = rpc_info_open,
 457         .read           = seq_read,
 458         .llseek         = seq_lseek,
 459         .release        = rpc_info_release,
 460 };
 461
 462
 463 /*
 464  * Description of fs contents.
 465  */
 466 struct rpc_filelist {
 467         const char *name;
 468         const struct file_operations *i_fop;
 469         umode_t mode;
 470 };
 471
 472 static struct inode *
 473 rpc_get_inode(struct super_block *sb, umode_t mode)
 474 {
 475         struct inode *inode = new_inode(sb);
 476         if (!inode)
 477                 return NULL;
 478         inode->i_ino = get_next_ino();
 479         inode->i_mode = mode;
 480         inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 481         switch (mode & S_IFMT) {
 482         case S_IFDIR:
 483                 inode->i_fop = &simple_dir_operations;
 484                 inode->i_op = &simple_dir_inode_operations;
 485                 inc_nlink(inode);
 486         default:
 487                 break;
 488         }
 489         return inode;
 490 }
 491
 492 static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
 493                                umode_t mode,
 494                                const struct file_operations *i_fop,
 495                                void *private)
 496 {
 497         struct inode *inode;
 498
 499         d_drop(dentry);
 500         inode = rpc_get_inode(dir->i_sb, mode);
 501         if (!inode)
 502                 goto out_err;
 503         inode->i_ino = iunique(dir->i_sb, 100);
 504         if (i_fop)
 505                 inode->i_fop = i_fop;
 506         if (private)
 507                 rpc_inode_setowner(inode, private);
 508         d_add(dentry, inode);
 509         return 0;
 510 out_err:
 511         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %pd\n",
 512                         __FILE__, __func__, dentry);
 513         dput(dentry);
 514         return -ENOMEM;
 515 }
 516
 517 static int __rpc_create(struct inode *dir, struct dentry *dentry,
 518                         umode_t mode,
 519                         const struct file_operations *i_fop,
 520                         void *private)
 521 {
 522         int err;
 523
 524         err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
 525         if (err)
 526                 return err;
 527         fsnotify_create(dir, dentry);
 528         return 0;
 529 }
 530
 531 static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
 532                        umode_t mode,
 533                        const struct file_operations *i_fop,
 534                        void *private)
 535 {
 536         int err;
 537
 538         err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
 539         if (err)
 540                 return err;
 541         inc_nlink(dir);
 542         fsnotify_mkdir(dir, dentry);
 543         return 0;
 544 }
 545
 546 static void
 547 init_pipe(struct rpc_pipe *pipe)
 548 {
 549         pipe->nreaders = 0;
 550         pipe->nwriters = 0;
 551         INIT_LIST_HEAD(&pipe->in_upcall);
 552         INIT_LIST_HEAD(&pipe->in_downcall);
 553         INIT_LIST_HEAD(&pipe->pipe);
 554         pipe->pipelen = 0;
 555         INIT_DELAYED_WORK(&pipe->queue_timeout,
 556                             rpc_timeout_upcall_queue);
 557         pipe->ops = NULL;
 558         spin_lock_init(&pipe->lock);
 559         pipe->dentry = NULL;
 560 }
 561
 562 void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
 563 {
 564         kfree(pipe);
 565 }
 566 EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
 567
 568 struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
 569 {
 570         struct rpc_pipe *pipe;
 571
 572         pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
 573         if (!pipe)
 574                 return ERR_PTR(-ENOMEM);
 575         init_pipe(pipe);
 576         pipe->ops = ops;
 577         pipe->flags = flags;
 578         return pipe;
 579 }
 580 EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
 581
 582 static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
 583                                umode_t mode,
 584                                const struct file_operations *i_fop,
 585                                void *private,
 586                                struct rpc_pipe *pipe)
 587 {
 588         struct rpc_inode *rpci;
 589         int err;
 590
 591         err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
 592         if (err)
 593                 return err;
 594         rpci = RPC_I(d_inode(dentry));
 595         rpci->private = private;
 596         rpci->pipe = pipe;
 597         fsnotify_create(dir, dentry);
 598         return 0;
 599 }
 600
 601 static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 602 {
 603         int ret;
 604
 605         dget(dentry);
 606         ret = simple_rmdir(dir, dentry);
 607         d_delete(dentry);
 608         dput(dentry);
 609         return ret;
 610 }
 611
 612 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
 613 {
 614         int ret;
 615
 616         dget(dentry);
 617         ret = simple_unlink(dir, dentry);
 618         d_delete(dentry);
 619         dput(dentry);
 620         return ret;
 621 }
 622
 623 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
 624 {
 625         struct inode *inode = d_inode(dentry);
 626
 627         rpc_close_pipes(inode);
 628         return __rpc_unlink(dir, dentry);
 629 }
 630
 631 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
 632                                           const char *name)
 633 {
 634         struct qstr q = QSTR_INIT(name, strlen(name));
 635         struct dentry *dentry = d_hash_and_lookup(parent, &q);
 636         if (!dentry) {
 637                 dentry = d_alloc(parent, &q);
 638                 if (!dentry)
 639                         return ERR_PTR(-ENOMEM);
 640         }
 641         if (d_really_is_negative(dentry))
 642                 return dentry;
 643         dput(dentry);
 644         return ERR_PTR(-EEXIST);
 645 }
 646
 647 /*
 648  * FIXME: This probably has races.
 649  */
 650 static void __rpc_depopulate(struct dentry *parent,
 651                              const struct rpc_filelist *files,
 652                              int start, int eof)
 653 {
 654         struct inode *dir = d_inode(parent);
 655         struct dentry *dentry;
 656         struct qstr name;
 657         int i;
 658
 659         for (i = start; i < eof; i++) {
 660                 name.name = files[i].name;
 661                 name.len = strlen(files[i].name);
 662                 dentry = d_hash_and_lookup(parent, &name);
 663
 664                 if (dentry == NULL)
 665                         continue;
 666                 if (d_really_is_negative(dentry))
 667                         goto next;
 668                 switch (d_inode(dentry)->i_mode & S_IFMT) {
 669                         default:
 670                                 BUG();
 671                         case S_IFREG:
 672                                 __rpc_unlink(dir, dentry);
 673                                 break;
 674                         case S_IFDIR:
 675                                 __rpc_rmdir(dir, dentry);
 676                 }
 677 next:
 678                 dput(dentry);
 679         }
 680 }
 681
 682 static void rpc_depopulate(struct dentry *parent,
 683                            const struct rpc_filelist *files,
 684                            int start, int eof)
 685 {
 686         struct inode *dir = d_inode(parent);
 687
 688         inode_lock_nested(dir, I_MUTEX_CHILD);
 689         __rpc_depopulate(parent, files, start, eof);
 690         inode_unlock(dir);
 691 }
 692
 693 static int rpc_populate(struct dentry *parent,
 694                         const struct rpc_filelist *files,
 695                         int start, int eof,
 696                         void *private)
 697 {
 698         struct inode *dir = d_inode(parent);
 699         struct dentry *dentry;
 700         int i, err;
 701
 702         inode_lock(dir);
 703         for (i = start; i < eof; i++) {
 704                 dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
 705                 err = PTR_ERR(dentry);
 706                 if (IS_ERR(dentry))
 707                         goto out_bad;
 708                 switch (files[i].mode & S_IFMT) {
 709                         default:
 710                                 BUG();
 711                         case S_IFREG:
 712                                 err = __rpc_create(dir, dentry,
 713                                                 files[i].mode,
 714                                                 files[i].i_fop,
 715                                                 private);
 716                                 break;
 717                         case S_IFDIR:
 718                                 err = __rpc_mkdir(dir, dentry,
 719                                                 files[i].mode,
 720                                                 NULL,
 721                                                 private);
 722                 }
 723                 if (err != 0)
 724                         goto out_bad;
 725         }
 726         inode_unlock(dir);
 727         return 0;
 728 out_bad:
 729         __rpc_depopulate(parent, files, start, eof);
 730         inode_unlock(dir);
 731         printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
 732                         __FILE__, __func__, parent);
 733         return err;
 734 }
 735
 736 static struct dentry *rpc_mkdir_populate(struct dentry *parent,
 737                 const char *name, umode_t mode, void *private,
 738                 int (*populate)(struct dentry *, void *), void *args_populate)
 739 {
 740         struct dentry *dentry;
 741         struct inode *dir = d_inode(parent);
 742         int error;
 743
 744         inode_lock_nested(dir, I_MUTEX_PARENT);
 745         dentry = __rpc_lookup_create_exclusive(parent, name);
 746         if (IS_ERR(dentry))
 747                 goto out;
 748         error = __rpc_mkdir(dir, dentry, mode, NULL, private);
 749         if (error != 0)
 750                 goto out_err;
 751         if (populate != NULL) {
 752                 error = populate(dentry, args_populate);
 753                 if (error)
 754                         goto err_rmdir;
 755         }
 756 out:
 757         inode_unlock(dir);
 758         return dentry;
 759 err_rmdir:
 760         __rpc_rmdir(dir, dentry);
 761 out_err:
 762         dentry = ERR_PTR(error);
 763         goto out;
 764 }
 765
 766 static int rpc_rmdir_depopulate(struct dentry *dentry,
 767                 void (*depopulate)(struct dentry *))
 768 {
 769         struct dentry *parent;
 770         struct inode *dir;
 771         int error;
 772
 773         parent = dget_parent(dentry);
 774         dir = d_inode(parent);
 775         inode_lock_nested(dir, I_MUTEX_PARENT);
 776         if (depopulate != NULL)
 777                 depopulate(dentry);
 778         error = __rpc_rmdir(dir, dentry);
 779         inode_unlock(dir);
 780         dput(parent);
 781         return error;
 782 }
 783
 784 /**
 785  * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
 786  * @parent: dentry of directory to create new "pipe" in
 787  * @name: name of pipe
 788  * @private: private data to associate with the pipe, for the caller's use
 789  * @pipe: &rpc_pipe containing input parameters
 790  *
 791  * Data is made available for userspace to read by calls to
 792  * rpc_queue_upcall().  The actual reads will result in calls to
 793  * @ops->upcall, which will be called with the file pointer,
 794  * message, and userspace buffer to copy to.
 795  *
 796  * Writes can come at any time, and do not necessarily have to be
 797  * responses to upcalls.  They will result in calls to @msg->downcall.
 798  *
 799  * The @private argument passed here will be available to all these methods
 800  * from the file pointer, via RPC_I(file_inode(file))->private.
 801  */
 802 struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
 803                                  void *private, struct rpc_pipe *pipe)
 804 {
 805         struct dentry *dentry;
 806         struct inode *dir = d_inode(parent);
 807         umode_t umode = S_IFIFO | 0600;
 808         int err;
 809
 810         if (pipe->ops->upcall == NULL)
 811                 umode &= ~0444;
 812         if (pipe->ops->downcall == NULL)
 813                 umode &= ~0222;
 814
 815         inode_lock_nested(dir, I_MUTEX_PARENT);
 816         dentry = __rpc_lookup_create_exclusive(parent, name);
 817         if (IS_ERR(dentry))
 818                 goto out;
 819         err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
 820                                   private, pipe);
 821         if (err)
 822                 goto out_err;
 823 out:
 824         inode_unlock(dir);
 825         return dentry;
 826 out_err:
 827         dentry = ERR_PTR(err);
 828         printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n",
 829                         __FILE__, __func__, parent, name,
 830                         err);
 831         goto out;
 832 }
 833 EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
 834
 835 /**
 836  * rpc_unlink - remove a pipe
 837  * @dentry: dentry for the pipe, as returned from rpc_mkpipe
 838  *
 839  * After this call, lookups will no longer find the pipe, and any
 840  * attempts to read or write using preexisting opens of the pipe will
 841  * return -EPIPE.
 842  */
 843 int
 844 rpc_unlink(struct dentry *dentry)
 845 {
 846         struct dentry *parent;
 847         struct inode *dir;
 848         int error = 0;
 849
 850         parent = dget_parent(dentry);
 851         dir = d_inode(parent);
 852         inode_lock_nested(dir, I_MUTEX_PARENT);
 853         error = __rpc_rmpipe(dir, dentry);
 854         inode_unlock(dir);
 855         dput(parent);
 856         return error;
 857 }
 858 EXPORT_SYMBOL_GPL(rpc_unlink);
 859
 860 /**
 861  * rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head
 862  * @pdh: pointer to struct rpc_pipe_dir_head
 863  */
 864 void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh)
 865 {
 866         INIT_LIST_HEAD(&pdh->pdh_entries);
 867         pdh->pdh_dentry = NULL;
 868 }
 869 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head);
 870
 871 /**
 872  * rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object
 873  * @pdo: pointer to struct rpc_pipe_dir_object
 874  * @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops
 875  * @pdo_data: pointer to caller-defined data
 876  */
 877 void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
 878                 const struct rpc_pipe_dir_object_ops *pdo_ops,
 879                 void *pdo_data)
 880 {
 881         INIT_LIST_HEAD(&pdo->pdo_head);
 882         pdo->pdo_ops = pdo_ops;
 883         pdo->pdo_data = pdo_data;
 884 }
 885 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
 886
 887 static int
 888 rpc_add_pipe_dir_object_locked(struct net *net,
 889                 struct rpc_pipe_dir_head *pdh,
 890                 struct rpc_pipe_dir_object *pdo)
 891 {
 892         int ret = 0;
 893
 894         if (pdh->pdh_dentry)
 895                 ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo);
 896         if (ret == 0)
 897                 list_add_tail(&pdo->pdo_head, &pdh->pdh_entries);
 898         return ret;
 899 }
 900
 901 static void
 902 rpc_remove_pipe_dir_object_locked(struct net *net,
 903                 struct rpc_pipe_dir_head *pdh,
 904                 struct rpc_pipe_dir_object *pdo)
 905 {
 906         if (pdh->pdh_dentry)
 907                 pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo);
 908         list_del_init(&pdo->pdo_head);
 909 }
 910
 911 /**
 912  * rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory
 913  * @net: pointer to struct net
 914  * @pdh: pointer to struct rpc_pipe_dir_head
 915  * @pdo: pointer to struct rpc_pipe_dir_object
 916  *
 917  */
 918 int
 919 rpc_add_pipe_dir_object(struct net *net,
 920                 struct rpc_pipe_dir_head *pdh,
 921                 struct rpc_pipe_dir_object *pdo)
 922 {
 923         int ret = 0;
 924
 925         if (list_empty(&pdo->pdo_head)) {
 926                 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 927
 928                 mutex_lock(&sn->pipefs_sb_lock);
 929                 ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo);
 930                 mutex_unlock(&sn->pipefs_sb_lock);
 931         }
 932         return ret;
 933 }
 934 EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object);
 935
 936 /**
 937  * rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory
 938  * @net: pointer to struct net
 939  * @pdh: pointer to struct rpc_pipe_dir_head
 940  * @pdo: pointer to struct rpc_pipe_dir_object
 941  *
 942  */
 943 void
 944 rpc_remove_pipe_dir_object(struct net *net,
 945                 struct rpc_pipe_dir_head *pdh,
 946                 struct rpc_pipe_dir_object *pdo)
 947 {
 948         if (!list_empty(&pdo->pdo_head)) {
 949                 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 950
 951                 mutex_lock(&sn->pipefs_sb_lock);
 952                 rpc_remove_pipe_dir_object_locked(net, pdh, pdo);
 953                 mutex_unlock(&sn->pipefs_sb_lock);
 954         }
 955 }
 956 EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
 957
 958 /**
 959  * rpc_find_or_alloc_pipe_dir_object
 960  * @net: pointer to struct net
 961  * @pdh: pointer to struct rpc_pipe_dir_head
 962  * @match: match struct rpc_pipe_dir_object to data
 963  * @alloc: allocate a new struct rpc_pipe_dir_object
 964  * @data: user defined data for match() and alloc()
 965  *
 966  */
 967 struct rpc_pipe_dir_object *
 968 rpc_find_or_alloc_pipe_dir_object(struct net *net,
 969                 struct rpc_pipe_dir_head *pdh,
 970                 int (*match)(struct rpc_pipe_dir_object *, void *),
 971                 struct rpc_pipe_dir_object *(*alloc)(void *),
 972                 void *data)
 973 {
 974         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 975         struct rpc_pipe_dir_object *pdo;
 976
 977         mutex_lock(&sn->pipefs_sb_lock);
 978         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
 979                 if (!match(pdo, data))
 980                         continue;
 981                 goto out;
 982         }
 983         pdo = alloc(data);
 984         if (!pdo)
 985                 goto out;
 986         rpc_add_pipe_dir_object_locked(net, pdh, pdo);
 987 out:
 988         mutex_unlock(&sn->pipefs_sb_lock);
 989         return pdo;
 990 }
 991 EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
 992
 993 static void
 994 rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
 995 {
 996         struct rpc_pipe_dir_object *pdo;
 997         struct dentry *dir = pdh->pdh_dentry;
 998
 999         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1000                 pdo->pdo_ops->create(dir, pdo);
1001 }
1002
1003 static void
1004 rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
1005 {
1006         struct rpc_pipe_dir_object *pdo;
1007         struct dentry *dir = pdh->pdh_dentry;
1008
1009         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1010                 pdo->pdo_ops->destroy(dir, pdo);
1011 }
1012
1013 enum {
1014         RPCAUTH_info,
1015         RPCAUTH_EOF
1016 };
1017
1018 static const struct rpc_filelist authfiles[] = {
1019         [RPCAUTH_info] = {
1020                 .name = "info",
1021                 .i_fop = &rpc_info_operations,
1022                 .mode = S_IFREG | 0400,
1023         },
1024 };
1025
1026 static int rpc_clntdir_populate(struct dentry *dentry, void *private)
1027 {
1028         return rpc_populate(dentry,
1029                             authfiles, RPCAUTH_info, RPCAUTH_EOF,
1030                             private);
1031 }
1032
1033 static void rpc_clntdir_depopulate(struct dentry *dentry)
1034 {
1035         rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
1036 }
1037
1038 /**
1039  * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
1040  * @dentry: the parent of new directory
1041  * @name: the name of new directory
1042  * @rpc_client: rpc client to associate with this directory
1043  *
1044  * This creates a directory at the given @path associated with
1045  * @rpc_clnt, which will contain a file named "info" with some basic
1046  * information about the client, together with any "pipes" that may
1047  * later be created using rpc_mkpipe().
1048  */
1049 struct dentry *rpc_create_client_dir(struct dentry *dentry,
1050                                    const char *name,
1051                                    struct rpc_clnt *rpc_client)
1052 {
1053         struct dentry *ret;
1054
1055         ret = rpc_mkdir_populate(dentry, name, 0555, NULL,
1056                                  rpc_clntdir_populate, rpc_client);
1057         if (!IS_ERR(ret)) {
1058                 rpc_client->cl_pipedir_objects.pdh_dentry = ret;
1059                 rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1060         }
1061         return ret;
1062 }
1063
1064 /**
1065  * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
1066  * @rpc_client: rpc_client for the pipe
1067  */
1068 int rpc_remove_client_dir(struct rpc_clnt *rpc_client)
1069 {
1070         struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry;
1071
1072         if (dentry == NULL)
1073                 return 0;
1074         rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1075         rpc_client->cl_pipedir_objects.pdh_dentry = NULL;
1076         return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
1077 }
1078
1079 static const struct rpc_filelist cache_pipefs_files[3] = {
1080         [0] = {
1081                 .name = "channel",
1082                 .i_fop = &cache_file_operations_pipefs,
1083                 .mode = S_IFREG | 0600,
1084         },
1085         [1] = {
1086                 .name = "content",
1087                 .i_fop = &content_file_operations_pipefs,
1088                 .mode = S_IFREG | 0400,
1089         },
1090         [2] = {
1091                 .name = "flush",
1092                 .i_fop = &cache_flush_operations_pipefs,
1093                 .mode = S_IFREG | 0600,
1094         },
1095 };
1096
1097 static int rpc_cachedir_populate(struct dentry *dentry, void *private)
1098 {
1099         return rpc_populate(dentry,
1100                             cache_pipefs_files, 0, 3,
1101                             private);
1102 }
1103
1104 static void rpc_cachedir_depopulate(struct dentry *dentry)
1105 {
1106         rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
1107 }
1108
1109 struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
1110                                     umode_t umode, struct cache_detail *cd)
1111 {
1112         return rpc_mkdir_populate(parent, name, umode, NULL,
1113                         rpc_cachedir_populate, cd);
1114 }
1115
1116 void rpc_remove_cache_dir(struct dentry *dentry)
1117 {
1118         rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
1119 }
1120
1121 /*
1122  * populate the filesystem
1123  */
1124 static const struct super_operations s_ops = {
1125         .alloc_inode    = rpc_alloc_inode,
1126         .destroy_inode  = rpc_destroy_inode,
1127         .statfs         = simple_statfs,
1128 };
1129
1130 #define RPCAUTH_GSSMAGIC 0x67596969
1131
1132 /*
1133  * We have a single directory with 1 node in it.
1134  */
1135 enum {
1136         RPCAUTH_lockd,
1137         RPCAUTH_mount,
1138         RPCAUTH_nfs,
1139         RPCAUTH_portmap,
1140         RPCAUTH_statd,
1141         RPCAUTH_nfsd4_cb,
1142         RPCAUTH_cache,
1143         RPCAUTH_nfsd,
1144         RPCAUTH_gssd,
1145         RPCAUTH_RootEOF
1146 };
1147
1148 static const struct rpc_filelist files[] = {
1149         [RPCAUTH_lockd] = {
1150                 .name = "lockd",
1151                 .mode = S_IFDIR | 0555,
1152         },
1153         [RPCAUTH_mount] = {
1154                 .name = "mount",
1155                 .mode = S_IFDIR | 0555,
1156         },
1157         [RPCAUTH_nfs] = {
1158                 .name = "nfs",
1159                 .mode = S_IFDIR | 0555,
1160         },
1161         [RPCAUTH_portmap] = {
1162                 .name = "portmap",
1163                 .mode = S_IFDIR | 0555,
1164         },
1165         [RPCAUTH_statd] = {
1166                 .name = "statd",
1167                 .mode = S_IFDIR | 0555,
1168         },
1169         [RPCAUTH_nfsd4_cb] = {
1170                 .name = "nfsd4_cb",
1171                 .mode = S_IFDIR | 0555,
1172         },
1173         [RPCAUTH_cache] = {
1174                 .name = "cache",
1175                 .mode = S_IFDIR | 0555,
1176         },
1177         [RPCAUTH_nfsd] = {
1178                 .name = "nfsd",
1179                 .mode = S_IFDIR | 0555,
1180         },
1181         [RPCAUTH_gssd] = {
1182                 .name = "gssd",
1183                 .mode = S_IFDIR | 0555,
1184         },
1185 };
1186
1187 /*
1188  * This call can be used only in RPC pipefs mount notification hooks.
1189  */
1190 struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1191                                const unsigned char *dir_name)
1192 {
1193         struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
1194         return d_hash_and_lookup(sb->s_root, &dir);
1195 }
1196 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1197
1198 int rpc_pipefs_init_net(struct net *net)
1199 {
1200         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1201
1202         sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0);
1203         if (IS_ERR(sn->gssd_dummy))
1204                 return PTR_ERR(sn->gssd_dummy);
1205
1206         mutex_init(&sn->pipefs_sb_lock);
1207         sn->pipe_version = -1;
1208         return 0;
1209 }
1210
1211 void rpc_pipefs_exit_net(struct net *net)
1212 {
1213         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1214
1215         rpc_destroy_pipe_data(sn->gssd_dummy);
1216 }
1217
1218 /*
1219  * This call will be used for per network namespace operations calls.
1220  * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1221  * found. This lock have to be released by rpc_put_sb_net() when all operations
1222  * will be completed.
1223  */
1224 struct super_block *rpc_get_sb_net(const struct net *net)
1225 {
1226         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1227
1228         mutex_lock(&sn->pipefs_sb_lock);
1229         if (sn->pipefs_sb)
1230                 return sn->pipefs_sb;
1231         mutex_unlock(&sn->pipefs_sb_lock);
1232         return NULL;
1233 }
1234 EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1235
1236 void rpc_put_sb_net(const struct net *net)
1237 {
1238         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1239
1240         WARN_ON(sn->pipefs_sb == NULL);
1241         mutex_unlock(&sn->pipefs_sb_lock);
1242 }
1243 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1244
1245 static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
1246         [0] = {
1247                 .name = "clntXX",
1248                 .mode = S_IFDIR | 0555,
1249         },
1250 };
1251
1252 static ssize_t
1253 dummy_downcall(struct file *filp, const char __user *src, size_t len)
1254 {
1255         return -EINVAL;
1256 }
1257
1258 static const struct rpc_pipe_ops gssd_dummy_pipe_ops = {
1259         .upcall         = rpc_pipe_generic_upcall,
1260         .downcall       = dummy_downcall,
1261 };
1262
1263 /*
1264  * Here we present a bogus "info" file to keep rpc.gssd happy. We don't expect
1265  * that it will ever use this info to handle an upcall, but rpc.gssd expects
1266  * that this file will be there and have a certain format.
1267  */
1268 static int
1269 rpc_dummy_info_show(struct seq_file *m, void *v)
1270 {
1271         seq_printf(m, "RPC server: %s\n", utsname()->nodename);
1272         seq_printf(m, "service: foo (1) version 0\n");
1273         seq_printf(m, "address: 127.0.0.1\n");
1274         seq_printf(m, "protocol: tcp\n");
1275         seq_printf(m, "port: 0\n");
1276         return 0;
1277 }
1278 DEFINE_SHOW_ATTRIBUTE(rpc_dummy_info);
1279
1280 static const struct rpc_filelist gssd_dummy_info_file[] = {
1281         [0] = {
1282                 .name = "info",
1283                 .i_fop = &rpc_dummy_info_fops,
1284                 .mode = S_IFREG | 0400,
1285         },
1286 };
1287
1288 /**
1289  * rpc_gssd_dummy_populate - create a dummy gssd pipe
1290  * @root:       root of the rpc_pipefs filesystem
1291  * @pipe_data:  pipe data created when netns is initialized
1292  *
1293  * Create a dummy set of directories and a pipe that gssd can hold open to
1294  * indicate that it is up and running.
1295  */
1296 static struct dentry *
1297 rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
1298 {
1299         int ret = 0;
1300         struct dentry *gssd_dentry;
1301         struct dentry *clnt_dentry = NULL;
1302         struct dentry *pipe_dentry = NULL;
1303         struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name,
1304                                   strlen(files[RPCAUTH_gssd].name));
1305
1306         /* We should never get this far if "gssd" doesn't exist */
1307         gssd_dentry = d_hash_and_lookup(root, &q);
1308         if (!gssd_dentry)
1309                 return ERR_PTR(-ENOENT);
1310
1311         ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
1312         if (ret) {
1313                 pipe_dentry = ERR_PTR(ret);
1314                 goto out;
1315         }
1316
1317         q.name = gssd_dummy_clnt_dir[0].name;
1318         q.len = strlen(gssd_dummy_clnt_dir[0].name);
1319         clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
1320         if (!clnt_dentry) {
1321                 pipe_dentry = ERR_PTR(-ENOENT);
1322                 goto out;
1323         }
1324
1325         ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL);
1326         if (ret) {
1327                 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1328                 pipe_dentry = ERR_PTR(ret);
1329                 goto out;
1330         }
1331
1332         pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data);
1333         if (IS_ERR(pipe_dentry)) {
1334                 __rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1);
1335                 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1336         }
1337 out:
1338         dput(clnt_dentry);
1339         dput(gssd_dentry);
1340         return pipe_dentry;
1341 }
1342
1343 static void
1344 rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry)
1345 {
1346         struct dentry *clnt_dir = pipe_dentry->d_parent;
1347         struct dentry *gssd_dir = clnt_dir->d_parent;
1348
1349         dget(pipe_dentry);
1350         __rpc_rmpipe(d_inode(clnt_dir), pipe_dentry);
1351         __rpc_depopulate(clnt_dir, gssd_dummy_info_file, 0, 1);
1352         __rpc_depopulate(gssd_dir, gssd_dummy_clnt_dir, 0, 1);
1353         dput(pipe_dentry);
1354 }
1355
1356 static int
1357 rpc_fill_super(struct super_block *sb, void *data, int silent)
1358 {
1359         struct inode *inode;
1360         struct dentry *root, *gssd_dentry;
1361         struct net *net = get_net(sb->s_fs_info);
1362         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1363         int err;
1364
1365         sb->s_blocksize = PAGE_SIZE;
1366         sb->s_blocksize_bits = PAGE_SHIFT;
1367         sb->s_magic = RPCAUTH_GSSMAGIC;
1368         sb->s_op = &s_ops;
1369         sb->s_d_op = &simple_dentry_operations;
1370         sb->s_time_gran = 1;
1371
1372         inode = rpc_get_inode(sb, S_IFDIR | 0555);
1373         sb->s_root = root = d_make_root(inode);
1374         if (!root)
1375                 return -ENOMEM;
1376         if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1377                 return -ENOMEM;
1378
1379         gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy);
1380         if (IS_ERR(gssd_dentry)) {
1381                 __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1382                 return PTR_ERR(gssd_dentry);
1383         }
1384
1385         dprintk("RPC:       sending pipefs MOUNT notification for net %x%s\n",
1386                 net->ns.inum, NET_NAME(net));
1387         mutex_lock(&sn->pipefs_sb_lock);
1388         sn->pipefs_sb = sb;
1389         err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1390                                            RPC_PIPEFS_MOUNT,
1391                                            sb);
1392         if (err)
1393                 goto err_depopulate;
1394         mutex_unlock(&sn->pipefs_sb_lock);
1395         return 0;
1396
1397 err_depopulate:
1398         rpc_gssd_dummy_depopulate(gssd_dentry);
1399         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1400                                            RPC_PIPEFS_UMOUNT,
1401                                            sb);
1402         sn->pipefs_sb = NULL;
1403         __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1404         mutex_unlock(&sn->pipefs_sb_lock);
1405         return err;
1406 }
1407
1408 bool
1409 gssd_running(struct net *net)
1410 {
1411         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1412         struct rpc_pipe *pipe = sn->gssd_dummy;
1413
1414         return pipe->nreaders || pipe->nwriters;
1415 }
1416 EXPORT_SYMBOL_GPL(gssd_running);
1417
1418 static struct dentry *
1419 rpc_mount(struct file_system_type *fs_type,
1420                 int flags, const char *dev_name, void *data)
1421 {
1422         struct net *net = current->nsproxy->net_ns;
1423         return mount_ns(fs_type, flags, data, net, net->user_ns, rpc_fill_super);
1424 }
1425
1426 static void rpc_kill_sb(struct super_block *sb)
1427 {
1428         struct net *net = sb->s_fs_info;
1429         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1430
1431         mutex_lock(&sn->pipefs_sb_lock);
1432         if (sn->pipefs_sb != sb) {
1433                 mutex_unlock(&sn->pipefs_sb_lock);
1434                 goto out;
1435         }
1436         sn->pipefs_sb = NULL;
1437         dprintk("RPC:       sending pipefs UMOUNT notification for net %x%s\n",
1438                 net->ns.inum, NET_NAME(net));
1439         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1440                                            RPC_PIPEFS_UMOUNT,
1441                                            sb);
1442         mutex_unlock(&sn->pipefs_sb_lock);
1443 out:
1444         kill_litter_super(sb);
1445         put_net(net);
1446 }
1447
1448 static struct file_system_type rpc_pipe_fs_type = {
1449         .owner          = THIS_MODULE,
1450         .name           = "rpc_pipefs",
1451         .mount          = rpc_mount,
1452         .kill_sb        = rpc_kill_sb,
1453 };
1454 MODULE_ALIAS_FS("rpc_pipefs");
1455 MODULE_ALIAS("rpc_pipefs");
1456
1457 static void
1458 init_once(void *foo)
1459 {
1460         struct rpc_inode *rpci = (struct rpc_inode *) foo;
1461
1462         inode_init_once(&rpci->vfs_inode);
1463         rpci->private = NULL;
1464         rpci->pipe = NULL;
1465         init_waitqueue_head(&rpci->waitq);
1466 }
1467
1468 int register_rpc_pipefs(void)
1469 {
1470         int err;
1471
1472         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1473                                 sizeof(struct rpc_inode),
1474                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1475                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1476                                 init_once);
1477         if (!rpc_inode_cachep)
1478                 return -ENOMEM;
1479         err = rpc_clients_notifier_register();
1480         if (err)
1481                 goto err_notifier;
1482         err = register_filesystem(&rpc_pipe_fs_type);
1483         if (err)
1484                 goto err_register;
1485         return 0;
1486
1487 err_register:
1488         rpc_clients_notifier_unregister();
1489 err_notifier:
1490         kmem_cache_destroy(rpc_inode_cachep);
1491         return err;
1492 }
1493
1494 void unregister_rpc_pipefs(void)
1495 {
1496         rpc_clients_notifier_unregister();
1497         kmem_cache_destroy(rpc_inode_cachep);
1498         unregister_filesystem(&rpc_pipe_fs_type);
1499 }