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