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 unsigned int
 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         unsigned int mask = POLLOUT | POLLWRNORM;
 349
 350         poll_wait(filp, &rpci->waitq, wait);
 351
 352         inode_lock(inode);
 353         if (rpci->pipe == NULL)
 354                 mask |= POLLERR | POLLHUP;
 355         else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
 356                 mask |= POLLIN | POLLRDNORM;
 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;
 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 int rpc_rmdir(struct dentry *dentry)
 613 {
 614         struct dentry *parent;
 615         struct inode *dir;
 616         int error;
 617
 618         parent = dget_parent(dentry);
 619         dir = d_inode(parent);
 620         inode_lock_nested(dir, I_MUTEX_PARENT);
 621         error = __rpc_rmdir(dir, dentry);
 622         inode_unlock(dir);
 623         dput(parent);
 624         return error;
 625 }
 626 EXPORT_SYMBOL_GPL(rpc_rmdir);
 627
 628 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
 629 {
 630         int ret;
 631
 632         dget(dentry);
 633         ret = simple_unlink(dir, dentry);
 634         d_delete(dentry);
 635         dput(dentry);
 636         return ret;
 637 }
 638
 639 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
 640 {
 641         struct inode *inode = d_inode(dentry);
 642
 643         rpc_close_pipes(inode);
 644         return __rpc_unlink(dir, dentry);
 645 }
 646
 647 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
 648                                           const char *name)
 649 {
 650         struct qstr q = QSTR_INIT(name, strlen(name));
 651         struct dentry *dentry = d_hash_and_lookup(parent, &q);
 652         if (!dentry) {
 653                 dentry = d_alloc(parent, &q);
 654                 if (!dentry)
 655                         return ERR_PTR(-ENOMEM);
 656         }
 657         if (d_really_is_negative(dentry))
 658                 return dentry;
 659         dput(dentry);
 660         return ERR_PTR(-EEXIST);
 661 }
 662
 663 /*
 664  * FIXME: This probably has races.
 665  */
 666 static void __rpc_depopulate(struct dentry *parent,
 667                              const struct rpc_filelist *files,
 668                              int start, int eof)
 669 {
 670         struct inode *dir = d_inode(parent);
 671         struct dentry *dentry;
 672         struct qstr name;
 673         int i;
 674
 675         for (i = start; i < eof; i++) {
 676                 name.name = files[i].name;
 677                 name.len = strlen(files[i].name);
 678                 dentry = d_hash_and_lookup(parent, &name);
 679
 680                 if (dentry == NULL)
 681                         continue;
 682                 if (d_really_is_negative(dentry))
 683                         goto next;
 684                 switch (d_inode(dentry)->i_mode & S_IFMT) {
 685                         default:
 686                                 BUG();
 687                         case S_IFREG:
 688                                 __rpc_unlink(dir, dentry);
 689                                 break;
 690                         case S_IFDIR:
 691                                 __rpc_rmdir(dir, dentry);
 692                 }
 693 next:
 694                 dput(dentry);
 695         }
 696 }
 697
 698 static void rpc_depopulate(struct dentry *parent,
 699                            const struct rpc_filelist *files,
 700                            int start, int eof)
 701 {
 702         struct inode *dir = d_inode(parent);
 703
 704         inode_lock_nested(dir, I_MUTEX_CHILD);
 705         __rpc_depopulate(parent, files, start, eof);
 706         inode_unlock(dir);
 707 }
 708
 709 static int rpc_populate(struct dentry *parent,
 710                         const struct rpc_filelist *files,
 711                         int start, int eof,
 712                         void *private)
 713 {
 714         struct inode *dir = d_inode(parent);
 715         struct dentry *dentry;
 716         int i, err;
 717
 718         inode_lock(dir);
 719         for (i = start; i < eof; i++) {
 720                 dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
 721                 err = PTR_ERR(dentry);
 722                 if (IS_ERR(dentry))
 723                         goto out_bad;
 724                 switch (files[i].mode & S_IFMT) {
 725                         default:
 726                                 BUG();
 727                         case S_IFREG:
 728                                 err = __rpc_create(dir, dentry,
 729                                                 files[i].mode,
 730                                                 files[i].i_fop,
 731                                                 private);
 732                                 break;
 733                         case S_IFDIR:
 734                                 err = __rpc_mkdir(dir, dentry,
 735                                                 files[i].mode,
 736                                                 NULL,
 737                                                 private);
 738                 }
 739                 if (err != 0)
 740                         goto out_bad;
 741         }
 742         inode_unlock(dir);
 743         return 0;
 744 out_bad:
 745         __rpc_depopulate(parent, files, start, eof);
 746         inode_unlock(dir);
 747         printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
 748                         __FILE__, __func__, parent);
 749         return err;
 750 }
 751
 752 static struct dentry *rpc_mkdir_populate(struct dentry *parent,
 753                 const char *name, umode_t mode, void *private,
 754                 int (*populate)(struct dentry *, void *), void *args_populate)
 755 {
 756         struct dentry *dentry;
 757         struct inode *dir = d_inode(parent);
 758         int error;
 759
 760         inode_lock_nested(dir, I_MUTEX_PARENT);
 761         dentry = __rpc_lookup_create_exclusive(parent, name);
 762         if (IS_ERR(dentry))
 763                 goto out;
 764         error = __rpc_mkdir(dir, dentry, mode, NULL, private);
 765         if (error != 0)
 766                 goto out_err;
 767         if (populate != NULL) {
 768                 error = populate(dentry, args_populate);
 769                 if (error)
 770                         goto err_rmdir;
 771         }
 772 out:
 773         inode_unlock(dir);
 774         return dentry;
 775 err_rmdir:
 776         __rpc_rmdir(dir, dentry);
 777 out_err:
 778         dentry = ERR_PTR(error);
 779         goto out;
 780 }
 781
 782 static int rpc_rmdir_depopulate(struct dentry *dentry,
 783                 void (*depopulate)(struct dentry *))
 784 {
 785         struct dentry *parent;
 786         struct inode *dir;
 787         int error;
 788
 789         parent = dget_parent(dentry);
 790         dir = d_inode(parent);
 791         inode_lock_nested(dir, I_MUTEX_PARENT);
 792         if (depopulate != NULL)
 793                 depopulate(dentry);
 794         error = __rpc_rmdir(dir, dentry);
 795         inode_unlock(dir);
 796         dput(parent);
 797         return error;
 798 }
 799
 800 /**
 801  * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
 802  * @parent: dentry of directory to create new "pipe" in
 803  * @name: name of pipe
 804  * @private: private data to associate with the pipe, for the caller's use
 805  * @pipe: &rpc_pipe containing input parameters
 806  *
 807  * Data is made available for userspace to read by calls to
 808  * rpc_queue_upcall().  The actual reads will result in calls to
 809  * @ops->upcall, which will be called with the file pointer,
 810  * message, and userspace buffer to copy to.
 811  *
 812  * Writes can come at any time, and do not necessarily have to be
 813  * responses to upcalls.  They will result in calls to @msg->downcall.
 814  *
 815  * The @private argument passed here will be available to all these methods
 816  * from the file pointer, via RPC_I(file_inode(file))->private.
 817  */
 818 struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
 819                                  void *private, struct rpc_pipe *pipe)
 820 {
 821         struct dentry *dentry;
 822         struct inode *dir = d_inode(parent);
 823         umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
 824         int err;
 825
 826         if (pipe->ops->upcall == NULL)
 827                 umode &= ~S_IRUGO;
 828         if (pipe->ops->downcall == NULL)
 829                 umode &= ~S_IWUGO;
 830
 831         inode_lock_nested(dir, I_MUTEX_PARENT);
 832         dentry = __rpc_lookup_create_exclusive(parent, name);
 833         if (IS_ERR(dentry))
 834                 goto out;
 835         err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
 836                                   private, pipe);
 837         if (err)
 838                 goto out_err;
 839 out:
 840         inode_unlock(dir);
 841         return dentry;
 842 out_err:
 843         dentry = ERR_PTR(err);
 844         printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n",
 845                         __FILE__, __func__, parent, name,
 846                         err);
 847         goto out;
 848 }
 849 EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
 850
 851 /**
 852  * rpc_unlink - remove a pipe
 853  * @dentry: dentry for the pipe, as returned from rpc_mkpipe
 854  *
 855  * After this call, lookups will no longer find the pipe, and any
 856  * attempts to read or write using preexisting opens of the pipe will
 857  * return -EPIPE.
 858  */
 859 int
 860 rpc_unlink(struct dentry *dentry)
 861 {
 862         struct dentry *parent;
 863         struct inode *dir;
 864         int error = 0;
 865
 866         parent = dget_parent(dentry);
 867         dir = d_inode(parent);
 868         inode_lock_nested(dir, I_MUTEX_PARENT);
 869         error = __rpc_rmpipe(dir, dentry);
 870         inode_unlock(dir);
 871         dput(parent);
 872         return error;
 873 }
 874 EXPORT_SYMBOL_GPL(rpc_unlink);
 875
 876 /**
 877  * rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head
 878  * @pdh: pointer to struct rpc_pipe_dir_head
 879  */
 880 void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh)
 881 {
 882         INIT_LIST_HEAD(&pdh->pdh_entries);
 883         pdh->pdh_dentry = NULL;
 884 }
 885 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head);
 886
 887 /**
 888  * rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object
 889  * @pdo: pointer to struct rpc_pipe_dir_object
 890  * @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops
 891  * @pdo_data: pointer to caller-defined data
 892  */
 893 void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
 894                 const struct rpc_pipe_dir_object_ops *pdo_ops,
 895                 void *pdo_data)
 896 {
 897         INIT_LIST_HEAD(&pdo->pdo_head);
 898         pdo->pdo_ops = pdo_ops;
 899         pdo->pdo_data = pdo_data;
 900 }
 901 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
 902
 903 static int
 904 rpc_add_pipe_dir_object_locked(struct net *net,
 905                 struct rpc_pipe_dir_head *pdh,
 906                 struct rpc_pipe_dir_object *pdo)
 907 {
 908         int ret = 0;
 909
 910         if (pdh->pdh_dentry)
 911                 ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo);
 912         if (ret == 0)
 913                 list_add_tail(&pdo->pdo_head, &pdh->pdh_entries);
 914         return ret;
 915 }
 916
 917 static void
 918 rpc_remove_pipe_dir_object_locked(struct net *net,
 919                 struct rpc_pipe_dir_head *pdh,
 920                 struct rpc_pipe_dir_object *pdo)
 921 {
 922         if (pdh->pdh_dentry)
 923                 pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo);
 924         list_del_init(&pdo->pdo_head);
 925 }
 926
 927 /**
 928  * rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory
 929  * @net: pointer to struct net
 930  * @pdh: pointer to struct rpc_pipe_dir_head
 931  * @pdo: pointer to struct rpc_pipe_dir_object
 932  *
 933  */
 934 int
 935 rpc_add_pipe_dir_object(struct net *net,
 936                 struct rpc_pipe_dir_head *pdh,
 937                 struct rpc_pipe_dir_object *pdo)
 938 {
 939         int ret = 0;
 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                 ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo);
 946                 mutex_unlock(&sn->pipefs_sb_lock);
 947         }
 948         return ret;
 949 }
 950 EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object);
 951
 952 /**
 953  * rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory
 954  * @net: pointer to struct net
 955  * @pdh: pointer to struct rpc_pipe_dir_head
 956  * @pdo: pointer to struct rpc_pipe_dir_object
 957  *
 958  */
 959 void
 960 rpc_remove_pipe_dir_object(struct net *net,
 961                 struct rpc_pipe_dir_head *pdh,
 962                 struct rpc_pipe_dir_object *pdo)
 963 {
 964         if (!list_empty(&pdo->pdo_head)) {
 965                 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 966
 967                 mutex_lock(&sn->pipefs_sb_lock);
 968                 rpc_remove_pipe_dir_object_locked(net, pdh, pdo);
 969                 mutex_unlock(&sn->pipefs_sb_lock);
 970         }
 971 }
 972 EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
 973
 974 /**
 975  * rpc_find_or_alloc_pipe_dir_object
 976  * @net: pointer to struct net
 977  * @pdh: pointer to struct rpc_pipe_dir_head
 978  * @match: match struct rpc_pipe_dir_object to data
 979  * @alloc: allocate a new struct rpc_pipe_dir_object
 980  * @data: user defined data for match() and alloc()
 981  *
 982  */
 983 struct rpc_pipe_dir_object *
 984 rpc_find_or_alloc_pipe_dir_object(struct net *net,
 985                 struct rpc_pipe_dir_head *pdh,
 986                 int (*match)(struct rpc_pipe_dir_object *, void *),
 987                 struct rpc_pipe_dir_object *(*alloc)(void *),
 988                 void *data)
 989 {
 990         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 991         struct rpc_pipe_dir_object *pdo;
 992
 993         mutex_lock(&sn->pipefs_sb_lock);
 994         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
 995                 if (!match(pdo, data))
 996                         continue;
 997                 goto out;
 998         }
 999         pdo = alloc(data);
1000         if (!pdo)
1001                 goto out;
1002         rpc_add_pipe_dir_object_locked(net, pdh, pdo);
1003 out:
1004         mutex_unlock(&sn->pipefs_sb_lock);
1005         return pdo;
1006 }
1007 EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
1008
1009 static void
1010 rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
1011 {
1012         struct rpc_pipe_dir_object *pdo;
1013         struct dentry *dir = pdh->pdh_dentry;
1014
1015         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1016                 pdo->pdo_ops->create(dir, pdo);
1017 }
1018
1019 static void
1020 rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
1021 {
1022         struct rpc_pipe_dir_object *pdo;
1023         struct dentry *dir = pdh->pdh_dentry;
1024
1025         list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1026                 pdo->pdo_ops->destroy(dir, pdo);
1027 }
1028
1029 enum {
1030         RPCAUTH_info,
1031         RPCAUTH_EOF
1032 };
1033
1034 static const struct rpc_filelist authfiles[] = {
1035         [RPCAUTH_info] = {
1036                 .name = "info",
1037                 .i_fop = &rpc_info_operations,
1038                 .mode = S_IFREG | S_IRUSR,
1039         },
1040 };
1041
1042 static int rpc_clntdir_populate(struct dentry *dentry, void *private)
1043 {
1044         return rpc_populate(dentry,
1045                             authfiles, RPCAUTH_info, RPCAUTH_EOF,
1046                             private);
1047 }
1048
1049 static void rpc_clntdir_depopulate(struct dentry *dentry)
1050 {
1051         rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
1052 }
1053
1054 /**
1055  * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
1056  * @dentry: the parent of new directory
1057  * @name: the name of new directory
1058  * @rpc_client: rpc client to associate with this directory
1059  *
1060  * This creates a directory at the given @path associated with
1061  * @rpc_clnt, which will contain a file named "info" with some basic
1062  * information about the client, together with any "pipes" that may
1063  * later be created using rpc_mkpipe().
1064  */
1065 struct dentry *rpc_create_client_dir(struct dentry *dentry,
1066                                    const char *name,
1067                                    struct rpc_clnt *rpc_client)
1068 {
1069         struct dentry *ret;
1070
1071         ret = rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
1072                         rpc_clntdir_populate, rpc_client);
1073         if (!IS_ERR(ret)) {
1074                 rpc_client->cl_pipedir_objects.pdh_dentry = ret;
1075                 rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1076         }
1077         return ret;
1078 }
1079
1080 /**
1081  * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
1082  * @rpc_client: rpc_client for the pipe
1083  */
1084 int rpc_remove_client_dir(struct rpc_clnt *rpc_client)
1085 {
1086         struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry;
1087
1088         if (dentry == NULL)
1089                 return 0;
1090         rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1091         rpc_client->cl_pipedir_objects.pdh_dentry = NULL;
1092         return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
1093 }
1094
1095 static const struct rpc_filelist cache_pipefs_files[3] = {
1096         [0] = {
1097                 .name = "channel",
1098                 .i_fop = &cache_file_operations_pipefs,
1099                 .mode = S_IFREG|S_IRUSR|S_IWUSR,
1100         },
1101         [1] = {
1102                 .name = "content",
1103                 .i_fop = &content_file_operations_pipefs,
1104                 .mode = S_IFREG|S_IRUSR,
1105         },
1106         [2] = {
1107                 .name = "flush",
1108                 .i_fop = &cache_flush_operations_pipefs,
1109                 .mode = S_IFREG|S_IRUSR|S_IWUSR,
1110         },
1111 };
1112
1113 static int rpc_cachedir_populate(struct dentry *dentry, void *private)
1114 {
1115         return rpc_populate(dentry,
1116                             cache_pipefs_files, 0, 3,
1117                             private);
1118 }
1119
1120 static void rpc_cachedir_depopulate(struct dentry *dentry)
1121 {
1122         rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
1123 }
1124
1125 struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
1126                                     umode_t umode, struct cache_detail *cd)
1127 {
1128         return rpc_mkdir_populate(parent, name, umode, NULL,
1129                         rpc_cachedir_populate, cd);
1130 }
1131
1132 void rpc_remove_cache_dir(struct dentry *dentry)
1133 {
1134         rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
1135 }
1136
1137 /*
1138  * populate the filesystem
1139  */
1140 static const struct super_operations s_ops = {
1141         .alloc_inode    = rpc_alloc_inode,
1142         .destroy_inode  = rpc_destroy_inode,
1143         .statfs         = simple_statfs,
1144 };
1145
1146 #define RPCAUTH_GSSMAGIC 0x67596969
1147
1148 /*
1149  * We have a single directory with 1 node in it.
1150  */
1151 enum {
1152         RPCAUTH_lockd,
1153         RPCAUTH_mount,
1154         RPCAUTH_nfs,
1155         RPCAUTH_portmap,
1156         RPCAUTH_statd,
1157         RPCAUTH_nfsd4_cb,
1158         RPCAUTH_cache,
1159         RPCAUTH_nfsd,
1160         RPCAUTH_gssd,
1161         RPCAUTH_RootEOF
1162 };
1163
1164 static const struct rpc_filelist files[] = {
1165         [RPCAUTH_lockd] = {
1166                 .name = "lockd",
1167                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1168         },
1169         [RPCAUTH_mount] = {
1170                 .name = "mount",
1171                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1172         },
1173         [RPCAUTH_nfs] = {
1174                 .name = "nfs",
1175                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1176         },
1177         [RPCAUTH_portmap] = {
1178                 .name = "portmap",
1179                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1180         },
1181         [RPCAUTH_statd] = {
1182                 .name = "statd",
1183                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1184         },
1185         [RPCAUTH_nfsd4_cb] = {
1186                 .name = "nfsd4_cb",
1187                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1188         },
1189         [RPCAUTH_cache] = {
1190                 .name = "cache",
1191                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1192         },
1193         [RPCAUTH_nfsd] = {
1194                 .name = "nfsd",
1195                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1196         },
1197         [RPCAUTH_gssd] = {
1198                 .name = "gssd",
1199                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1200         },
1201 };
1202
1203 /*
1204  * This call can be used only in RPC pipefs mount notification hooks.
1205  */
1206 struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1207                                const unsigned char *dir_name)
1208 {
1209         struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
1210         return d_hash_and_lookup(sb->s_root, &dir);
1211 }
1212 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1213
1214 int rpc_pipefs_init_net(struct net *net)
1215 {
1216         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1217
1218         sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0);
1219         if (IS_ERR(sn->gssd_dummy))
1220                 return PTR_ERR(sn->gssd_dummy);
1221
1222         mutex_init(&sn->pipefs_sb_lock);
1223         sn->pipe_version = -1;
1224         return 0;
1225 }
1226
1227 void rpc_pipefs_exit_net(struct net *net)
1228 {
1229         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1230
1231         rpc_destroy_pipe_data(sn->gssd_dummy);
1232 }
1233
1234 /*
1235  * This call will be used for per network namespace operations calls.
1236  * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1237  * found. This lock have to be released by rpc_put_sb_net() when all operations
1238  * will be completed.
1239  */
1240 struct super_block *rpc_get_sb_net(const struct net *net)
1241 {
1242         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1243
1244         mutex_lock(&sn->pipefs_sb_lock);
1245         if (sn->pipefs_sb)
1246                 return sn->pipefs_sb;
1247         mutex_unlock(&sn->pipefs_sb_lock);
1248         return NULL;
1249 }
1250 EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1251
1252 void rpc_put_sb_net(const struct net *net)
1253 {
1254         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1255
1256         WARN_ON(sn->pipefs_sb == NULL);
1257         mutex_unlock(&sn->pipefs_sb_lock);
1258 }
1259 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1260
1261 static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
1262         [0] = {
1263                 .name = "clntXX",
1264                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1265         },
1266 };
1267
1268 static ssize_t
1269 dummy_downcall(struct file *filp, const char __user *src, size_t len)
1270 {
1271         return -EINVAL;
1272 }
1273
1274 static const struct rpc_pipe_ops gssd_dummy_pipe_ops = {
1275         .upcall         = rpc_pipe_generic_upcall,
1276         .downcall       = dummy_downcall,
1277 };
1278
1279 /*
1280  * Here we present a bogus "info" file to keep rpc.gssd happy. We don't expect
1281  * that it will ever use this info to handle an upcall, but rpc.gssd expects
1282  * that this file will be there and have a certain format.
1283  */
1284 static int
1285 rpc_show_dummy_info(struct seq_file *m, void *v)
1286 {
1287         seq_printf(m, "RPC server: %s\n", utsname()->nodename);
1288         seq_printf(m, "service: foo (1) version 0\n");
1289         seq_printf(m, "address: 127.0.0.1\n");
1290         seq_printf(m, "protocol: tcp\n");
1291         seq_printf(m, "port: 0\n");
1292         return 0;
1293 }
1294
1295 static int
1296 rpc_dummy_info_open(struct inode *inode, struct file *file)
1297 {
1298         return single_open(file, rpc_show_dummy_info, NULL);
1299 }
1300
1301 static const struct file_operations rpc_dummy_info_operations = {
1302         .owner          = THIS_MODULE,
1303         .open           = rpc_dummy_info_open,
1304         .read           = seq_read,
1305         .llseek         = seq_lseek,
1306         .release        = single_release,
1307 };
1308
1309 static const struct rpc_filelist gssd_dummy_info_file[] = {
1310         [0] = {
1311                 .name = "info",
1312                 .i_fop = &rpc_dummy_info_operations,
1313                 .mode = S_IFREG | S_IRUSR,
1314         },
1315 };
1316
1317 /**
1318  * rpc_gssd_dummy_populate - create a dummy gssd pipe
1319  * @root:       root of the rpc_pipefs filesystem
1320  * @pipe_data:  pipe data created when netns is initialized
1321  *
1322  * Create a dummy set of directories and a pipe that gssd can hold open to
1323  * indicate that it is up and running.
1324  */
1325 static struct dentry *
1326 rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
1327 {
1328         int ret = 0;
1329         struct dentry *gssd_dentry;
1330         struct dentry *clnt_dentry = NULL;
1331         struct dentry *pipe_dentry = NULL;
1332         struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name,
1333                                   strlen(files[RPCAUTH_gssd].name));
1334
1335         /* We should never get this far if "gssd" doesn't exist */
1336         gssd_dentry = d_hash_and_lookup(root, &q);
1337         if (!gssd_dentry)
1338                 return ERR_PTR(-ENOENT);
1339
1340         ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
1341         if (ret) {
1342                 pipe_dentry = ERR_PTR(ret);
1343                 goto out;
1344         }
1345
1346         q.name = gssd_dummy_clnt_dir[0].name;
1347         q.len = strlen(gssd_dummy_clnt_dir[0].name);
1348         clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
1349         if (!clnt_dentry) {
1350                 pipe_dentry = ERR_PTR(-ENOENT);
1351                 goto out;
1352         }
1353
1354         ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL);
1355         if (ret) {
1356                 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1357                 pipe_dentry = ERR_PTR(ret);
1358                 goto out;
1359         }
1360
1361         pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data);
1362         if (IS_ERR(pipe_dentry)) {
1363                 __rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1);
1364                 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1365         }
1366 out:
1367         dput(clnt_dentry);
1368         dput(gssd_dentry);
1369         return pipe_dentry;
1370 }
1371
1372 static void
1373 rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry)
1374 {
1375         struct dentry *clnt_dir = pipe_dentry->d_parent;
1376         struct dentry *gssd_dir = clnt_dir->d_parent;
1377
1378         __rpc_rmpipe(d_inode(clnt_dir), pipe_dentry);
1379         __rpc_depopulate(clnt_dir, gssd_dummy_info_file, 0, 1);
1380         __rpc_depopulate(gssd_dir, gssd_dummy_clnt_dir, 0, 1);
1381         dput(pipe_dentry);
1382 }
1383
1384 static int
1385 rpc_fill_super(struct super_block *sb, void *data, int silent)
1386 {
1387         struct inode *inode;
1388         struct dentry *root, *gssd_dentry;
1389         struct net *net = data;
1390         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1391         int err;
1392
1393         sb->s_blocksize = PAGE_SIZE;
1394         sb->s_blocksize_bits = PAGE_SHIFT;
1395         sb->s_magic = RPCAUTH_GSSMAGIC;
1396         sb->s_op = &s_ops;
1397         sb->s_d_op = &simple_dentry_operations;
1398         sb->s_time_gran = 1;
1399
1400         inode = rpc_get_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1401         sb->s_root = root = d_make_root(inode);
1402         if (!root)
1403                 return -ENOMEM;
1404         if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1405                 return -ENOMEM;
1406
1407         gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy);
1408         if (IS_ERR(gssd_dentry)) {
1409                 __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1410                 return PTR_ERR(gssd_dentry);
1411         }
1412
1413         dprintk("RPC:       sending pipefs MOUNT notification for net %p%s\n",
1414                 net, NET_NAME(net));
1415         mutex_lock(&sn->pipefs_sb_lock);
1416         sn->pipefs_sb = sb;
1417         err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1418                                            RPC_PIPEFS_MOUNT,
1419                                            sb);
1420         if (err)
1421                 goto err_depopulate;
1422         sb->s_fs_info = get_net(net);
1423         mutex_unlock(&sn->pipefs_sb_lock);
1424         return 0;
1425
1426 err_depopulate:
1427         rpc_gssd_dummy_depopulate(gssd_dentry);
1428         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1429                                            RPC_PIPEFS_UMOUNT,
1430                                            sb);
1431         sn->pipefs_sb = NULL;
1432         __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1433         mutex_unlock(&sn->pipefs_sb_lock);
1434         return err;
1435 }
1436
1437 bool
1438 gssd_running(struct net *net)
1439 {
1440         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1441         struct rpc_pipe *pipe = sn->gssd_dummy;
1442
1443         return pipe->nreaders || pipe->nwriters;
1444 }
1445 EXPORT_SYMBOL_GPL(gssd_running);
1446
1447 static struct dentry *
1448 rpc_mount(struct file_system_type *fs_type,
1449                 int flags, const char *dev_name, void *data)
1450 {
1451         return mount_ns(fs_type, flags, current->nsproxy->net_ns, rpc_fill_super);
1452 }
1453
1454 static void rpc_kill_sb(struct super_block *sb)
1455 {
1456         struct net *net = sb->s_fs_info;
1457         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1458
1459         mutex_lock(&sn->pipefs_sb_lock);
1460         if (sn->pipefs_sb != sb) {
1461                 mutex_unlock(&sn->pipefs_sb_lock);
1462                 goto out;
1463         }
1464         sn->pipefs_sb = NULL;
1465         dprintk("RPC:       sending pipefs UMOUNT notification for net %p%s\n",
1466                 net, NET_NAME(net));
1467         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1468                                            RPC_PIPEFS_UMOUNT,
1469                                            sb);
1470         mutex_unlock(&sn->pipefs_sb_lock);
1471         put_net(net);
1472 out:
1473         kill_litter_super(sb);
1474 }
1475
1476 static struct file_system_type rpc_pipe_fs_type = {
1477         .owner          = THIS_MODULE,
1478         .name           = "rpc_pipefs",
1479         .mount          = rpc_mount,
1480         .kill_sb        = rpc_kill_sb,
1481 };
1482 MODULE_ALIAS_FS("rpc_pipefs");
1483 MODULE_ALIAS("rpc_pipefs");
1484
1485 static void
1486 init_once(void *foo)
1487 {
1488         struct rpc_inode *rpci = (struct rpc_inode *) foo;
1489
1490         inode_init_once(&rpci->vfs_inode);
1491         rpci->private = NULL;
1492         rpci->pipe = NULL;
1493         init_waitqueue_head(&rpci->waitq);
1494 }
1495
1496 int register_rpc_pipefs(void)
1497 {
1498         int err;
1499
1500         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1501                                 sizeof(struct rpc_inode),
1502                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1503                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1504                                 init_once);
1505         if (!rpc_inode_cachep)
1506                 return -ENOMEM;
1507         err = rpc_clients_notifier_register();
1508         if (err)
1509                 goto err_notifier;
1510         err = register_filesystem(&rpc_pipe_fs_type);
1511         if (err)
1512                 goto err_register;
1513         return 0;
1514
1515 err_register:
1516         rpc_clients_notifier_unregister();
1517 err_notifier:
1518         kmem_cache_destroy(rpc_inode_cachep);
1519         return err;
1520 }
1521
1522 void unregister_rpc_pipefs(void)
1523 {
1524         rpc_clients_notifier_unregister();
1525         kmem_cache_destroy(rpc_inode_cachep);
1526         unregister_filesystem(&rpc_pipe_fs_type);
1527 }