Pileus Git - ~andy/linux/blob - 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
  20 #include <asm/ioctls.h>
  21 #include <linux/fs.h>
  22 #include <linux/poll.h>
  23 #include <linux/wait.h>
  24 #include <linux/seq_file.h>
  25
  26 #include <linux/sunrpc/clnt.h>
  27 #include <linux/workqueue.h>
  28 #include <linux/sunrpc/rpc_pipe_fs.h>
  29 #include <linux/sunrpc/cache.h>
  30 #include <linux/nsproxy.h>
  31 #include <linux/notifier.h>
  32
  33 #include "netns.h"
  34 #include "sunrpc.h"
  35
  36 #define RPCDBG_FACILITY RPCDBG_DEBUG
  37
  38 #define NET_NAME(net)   ((net == &init_net) ? " (init_net)" : "")
  39
  40 static struct vfsmount *rpc_mnt __read_mostly;
  41 static int rpc_mount_count;
  42
  43 static struct file_system_type rpc_pipe_fs_type;
  44
  45
  46 static struct kmem_cache *rpc_inode_cachep __read_mostly;
  47
  48 #define RPC_UPCALL_TIMEOUT (30*HZ)
  49
  50 static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
  51
  52 int rpc_pipefs_notifier_register(struct notifier_block *nb)
  53 {
  54         return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
  55 }
  56 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
  57
  58 void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
  59 {
  60         blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
  61 }
  62 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
  63
  64 static void rpc_purge_list(struct rpc_pipe *pipe, struct list_head *head,
  65                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
  66 {
  67         struct rpc_pipe_msg *msg;
  68
  69         if (list_empty(head))
  70                 return;
  71         do {
  72                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
  73                 list_del_init(&msg->list);
  74                 msg->errno = err;
  75                 destroy_msg(msg);
  76         } while (!list_empty(head));
  77         wake_up(&pipe->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
  88         spin_lock(&pipe->lock);
  89         destroy_msg = pipe->ops->destroy_msg;
  90         if (pipe->nreaders == 0) {
  91                 list_splice_init(&pipe->pipe, &free_list);
  92                 pipe->pipelen = 0;
  93         }
  94         spin_unlock(&pipe->lock);
  95         rpc_purge_list(pipe, &free_list, destroy_msg, -ETIMEDOUT);
  96 }
  97
  98 ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
  99                                 char __user *dst, size_t buflen)
 100 {
 101         char *data = (char *)msg->data + msg->copied;
 102         size_t mlen = min(msg->len - msg->copied, buflen);
 103         unsigned long left;
 104
 105         left = copy_to_user(dst, data, mlen);
 106         if (left == mlen) {
 107                 msg->errno = -EFAULT;
 108                 return -EFAULT;
 109         }
 110
 111         mlen -= left;
 112         msg->copied += mlen;
 113         msg->errno = 0;
 114         return mlen;
 115 }
 116 EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
 117
 118 /**
 119  * rpc_queue_upcall - queue an upcall message to userspace
 120  * @inode: inode of upcall pipe on which to queue given message
 121  * @msg: message to queue
 122  *
 123  * Call with an @inode created by rpc_mkpipe() to queue an upcall.
 124  * A userspace process may then later read the upcall by performing a
 125  * read on an open file for this inode.  It is up to the caller to
 126  * initialize the fields of @msg (other than @msg->list) appropriately.
 127  */
 128 int
 129 rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
 130 {
 131         int res = -EPIPE;
 132
 133         spin_lock(&pipe->lock);
 134         if (pipe->nreaders) {
 135                 list_add_tail(&msg->list, &pipe->pipe);
 136                 pipe->pipelen += msg->len;
 137                 res = 0;
 138         } else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
 139                 if (list_empty(&pipe->pipe))
 140                         queue_delayed_work(rpciod_workqueue,
 141                                         &pipe->queue_timeout,
 142                                         RPC_UPCALL_TIMEOUT);
 143                 list_add_tail(&msg->list, &pipe->pipe);
 144                 pipe->pipelen += msg->len;
 145                 res = 0;
 146         }
 147         spin_unlock(&pipe->lock);
 148         wake_up(&pipe->waitq);
 149         return res;
 150 }
 151 EXPORT_SYMBOL_GPL(rpc_queue_upcall);
 152
 153 static inline void
 154 rpc_inode_setowner(struct inode *inode, void *private)
 155 {
 156         RPC_I(inode)->private = private;
 157 }
 158
 159 static void
 160 rpc_close_pipes(struct inode *inode)
 161 {
 162         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 163         int need_release;
 164         LIST_HEAD(free_list);
 165
 166         mutex_lock(&inode->i_mutex);
 167         spin_lock(&pipe->lock);
 168         need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
 169         pipe->nreaders = 0;
 170         list_splice_init(&pipe->in_upcall, &free_list);
 171         list_splice_init(&pipe->pipe, &free_list);
 172         pipe->pipelen = 0;
 173         pipe->dentry = NULL;
 174         spin_unlock(&pipe->lock);
 175         rpc_purge_list(pipe, &free_list, pipe->ops->destroy_msg, -EPIPE);
 176         pipe->nwriters = 0;
 177         if (need_release && pipe->ops->release_pipe)
 178                 pipe->ops->release_pipe(inode);
 179         cancel_delayed_work_sync(&pipe->queue_timeout);
 180         rpc_inode_setowner(inode, NULL);
 181         mutex_unlock(&inode->i_mutex);
 182 }
 183
 184 static struct inode *
 185 rpc_alloc_inode(struct super_block *sb)
 186 {
 187         struct rpc_inode *rpci;
 188         rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
 189         if (!rpci)
 190                 return NULL;
 191         return &rpci->vfs_inode;
 192 }
 193
 194 static void
 195 rpc_i_callback(struct rcu_head *head)
 196 {
 197         struct inode *inode = container_of(head, struct inode, i_rcu);
 198         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 199 }
 200
 201 static void
 202 rpc_destroy_inode(struct inode *inode)
 203 {
 204         call_rcu(&inode->i_rcu, rpc_i_callback);
 205 }
 206
 207 static int
 208 rpc_pipe_open(struct inode *inode, struct file *filp)
 209 {
 210         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 211         int first_open;
 212         int res = -ENXIO;
 213
 214         mutex_lock(&inode->i_mutex);
 215         if (pipe->dentry == NULL)
 216                 goto out;
 217         first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
 218         if (first_open && pipe->ops->open_pipe) {
 219                 res = pipe->ops->open_pipe(inode);
 220                 if (res)
 221                         goto out;
 222         }
 223         if (filp->f_mode & FMODE_READ)
 224                 pipe->nreaders++;
 225         if (filp->f_mode & FMODE_WRITE)
 226                 pipe->nwriters++;
 227         res = 0;
 228 out:
 229         mutex_unlock(&inode->i_mutex);
 230         return res;
 231 }
 232
 233 static int
 234 rpc_pipe_release(struct inode *inode, struct file *filp)
 235 {
 236         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 237         struct rpc_pipe_msg *msg;
 238         int last_close;
 239
 240         mutex_lock(&inode->i_mutex);
 241         if (pipe->dentry == NULL)
 242                 goto out;
 243         msg = filp->private_data;
 244         if (msg != NULL) {
 245                 spin_lock(&pipe->lock);
 246                 msg->errno = -EAGAIN;
 247                 list_del_init(&msg->list);
 248                 spin_unlock(&pipe->lock);
 249                 pipe->ops->destroy_msg(msg);
 250         }
 251         if (filp->f_mode & FMODE_WRITE)
 252                 pipe->nwriters --;
 253         if (filp->f_mode & FMODE_READ) {
 254                 pipe->nreaders --;
 255                 if (pipe->nreaders == 0) {
 256                         LIST_HEAD(free_list);
 257                         spin_lock(&pipe->lock);
 258                         list_splice_init(&pipe->pipe, &free_list);
 259                         pipe->pipelen = 0;
 260                         spin_unlock(&pipe->lock);
 261                         rpc_purge_list(pipe, &free_list,
 262                                         pipe->ops->destroy_msg, -EAGAIN);
 263                 }
 264         }
 265         last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
 266         if (last_close && pipe->ops->release_pipe)
 267                 pipe->ops->release_pipe(inode);
 268 out:
 269         mutex_unlock(&inode->i_mutex);
 270         return 0;
 271 }
 272
 273 static ssize_t
 274 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 275 {
 276         struct inode *inode = filp->f_path.dentry->d_inode;
 277         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 278         struct rpc_pipe_msg *msg;
 279         int res = 0;
 280
 281         mutex_lock(&inode->i_mutex);
 282         if (pipe->dentry == NULL) {
 283                 res = -EPIPE;
 284                 goto out_unlock;
 285         }
 286         msg = filp->private_data;
 287         if (msg == NULL) {
 288                 spin_lock(&pipe->lock);
 289                 if (!list_empty(&pipe->pipe)) {
 290                         msg = list_entry(pipe->pipe.next,
 291                                         struct rpc_pipe_msg,
 292                                         list);
 293                         list_move(&msg->list, &pipe->in_upcall);
 294                         pipe->pipelen -= msg->len;
 295                         filp->private_data = msg;
 296                         msg->copied = 0;
 297                 }
 298                 spin_unlock(&pipe->lock);
 299                 if (msg == NULL)
 300                         goto out_unlock;
 301         }
 302         /* NOTE: it is up to the callback to update msg->copied */
 303         res = pipe->ops->upcall(filp, msg, buf, len);
 304         if (res < 0 || msg->len == msg->copied) {
 305                 filp->private_data = NULL;
 306                 spin_lock(&pipe->lock);
 307                 list_del_init(&msg->list);
 308                 spin_unlock(&pipe->lock);
 309                 pipe->ops->destroy_msg(msg);
 310         }
 311 out_unlock:
 312         mutex_unlock(&inode->i_mutex);
 313         return res;
 314 }
 315
 316 static ssize_t
 317 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 318 {
 319         struct inode *inode = filp->f_path.dentry->d_inode;
 320         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 321         int res;
 322
 323         mutex_lock(&inode->i_mutex);
 324         res = -EPIPE;
 325         if (pipe->dentry != NULL)
 326                 res = pipe->ops->downcall(filp, buf, len);
 327         mutex_unlock(&inode->i_mutex);
 328         return res;
 329 }
 330
 331 static unsigned int
 332 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 333 {
 334         struct rpc_pipe *pipe = RPC_I(filp->f_path.dentry->d_inode)->pipe;
 335         unsigned int mask = 0;
 336
 337         poll_wait(filp, &pipe->waitq, wait);
 338
 339         mask = POLLOUT | POLLWRNORM;
 340         if (pipe->dentry == NULL)
 341                 mask |= POLLERR | POLLHUP;
 342         if (filp->private_data || !list_empty(&pipe->pipe))
 343                 mask |= POLLIN | POLLRDNORM;
 344         return mask;
 345 }
 346
 347 static long
 348 rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 349 {
 350         struct inode *inode = filp->f_path.dentry->d_inode;
 351         struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 352         int len;
 353
 354         switch (cmd) {
 355         case FIONREAD:
 356                 spin_lock(&pipe->lock);
 357                 if (pipe->dentry == NULL) {
 358                         spin_unlock(&pipe->lock);
 359                         return -EPIPE;
 360                 }
 361                 len = pipe->pipelen;
 362                 if (filp->private_data) {
 363                         struct rpc_pipe_msg *msg;
 364                         msg = filp->private_data;
 365                         len += msg->len - msg->copied;
 366                 }
 367                 spin_unlock(&pipe->lock);
 368                 return put_user(len, (int __user *)arg);
 369         default:
 370                 return -EINVAL;
 371         }
 372 }
 373
 374 static const struct file_operations rpc_pipe_fops = {
 375         .owner          = THIS_MODULE,
 376         .llseek         = no_llseek,
 377         .read           = rpc_pipe_read,
 378         .write          = rpc_pipe_write,
 379         .poll           = rpc_pipe_poll,
 380         .unlocked_ioctl = rpc_pipe_ioctl,
 381         .open           = rpc_pipe_open,
 382         .release        = rpc_pipe_release,
 383 };
 384
 385 static int
 386 rpc_show_info(struct seq_file *m, void *v)
 387 {
 388         struct rpc_clnt *clnt = m->private;
 389
 390         seq_printf(m, "RPC server: %s\n", clnt->cl_server);
 391         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
 392                         clnt->cl_prog, clnt->cl_vers);
 393         seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
 394         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
 395         seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
 396         return 0;
 397 }
 398
 399 static int
 400 rpc_info_open(struct inode *inode, struct file *file)
 401 {
 402         struct rpc_clnt *clnt = NULL;
 403         int ret = single_open(file, rpc_show_info, NULL);
 404
 405         if (!ret) {
 406                 struct seq_file *m = file->private_data;
 407
 408                 spin_lock(&file->f_path.dentry->d_lock);
 409                 if (!d_unhashed(file->f_path.dentry))
 410                         clnt = RPC_I(inode)->private;
 411                 if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
 412                         spin_unlock(&file->f_path.dentry->d_lock);
 413                         m->private = clnt;
 414                 } else {
 415                         spin_unlock(&file->f_path.dentry->d_lock);
 416                         single_release(inode, file);
 417                         ret = -EINVAL;
 418                 }
 419         }
 420         return ret;
 421 }
 422
 423 static int
 424 rpc_info_release(struct inode *inode, struct file *file)
 425 {
 426         struct seq_file *m = file->private_data;
 427         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
 428
 429         if (clnt)
 430                 rpc_release_client(clnt);
 431         return single_release(inode, file);
 432 }
 433
 434 static const struct file_operations rpc_info_operations = {
 435         .owner          = THIS_MODULE,
 436         .open           = rpc_info_open,
 437         .read           = seq_read,
 438         .llseek         = seq_lseek,
 439         .release        = rpc_info_release,
 440 };
 441
 442
 443 /*
 444  * Description of fs contents.
 445  */
 446 struct rpc_filelist {
 447         const char *name;
 448         const struct file_operations *i_fop;
 449         umode_t mode;
 450 };
 451
 452 struct vfsmount *rpc_get_mount(void)
 453 {
 454         int err;
 455
 456         err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mnt, &rpc_mount_count);
 457         if (err != 0)
 458                 return ERR_PTR(err);
 459         return rpc_mnt;
 460 }
 461 EXPORT_SYMBOL_GPL(rpc_get_mount);
 462
 463 void rpc_put_mount(void)
 464 {
 465         simple_release_fs(&rpc_mnt, &rpc_mount_count);
 466 }
 467 EXPORT_SYMBOL_GPL(rpc_put_mount);
 468
 469 static int rpc_delete_dentry(const struct dentry *dentry)
 470 {
 471         return 1;
 472 }
 473
 474 static const struct dentry_operations rpc_dentry_operations = {
 475         .d_delete = rpc_delete_dentry,
 476 };
 477
 478 static struct inode *
 479 rpc_get_inode(struct super_block *sb, umode_t mode)
 480 {
 481         struct inode *inode = new_inode(sb);
 482         if (!inode)
 483                 return NULL;
 484         inode->i_ino = get_next_ino();
 485         inode->i_mode = mode;
 486         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 487         switch (mode & S_IFMT) {
 488         case S_IFDIR:
 489                 inode->i_fop = &simple_dir_operations;
 490                 inode->i_op = &simple_dir_inode_operations;
 491                 inc_nlink(inode);
 492         default:
 493                 break;
 494         }
 495         return inode;
 496 }
 497
 498 static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
 499                                umode_t mode,
 500                                const struct file_operations *i_fop,
 501                                void *private)
 502 {
 503         struct inode *inode;
 504
 505         d_drop(dentry);
 506         inode = rpc_get_inode(dir->i_sb, mode);
 507         if (!inode)
 508                 goto out_err;
 509         inode->i_ino = iunique(dir->i_sb, 100);
 510         if (i_fop)
 511                 inode->i_fop = i_fop;
 512         if (private)
 513                 rpc_inode_setowner(inode, private);
 514         d_add(dentry, inode);
 515         return 0;
 516 out_err:
 517         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
 518                         __FILE__, __func__, dentry->d_name.name);
 519         dput(dentry);
 520         return -ENOMEM;
 521 }
 522
 523 static int __rpc_create(struct inode *dir, struct dentry *dentry,
 524                         umode_t mode,
 525                         const struct file_operations *i_fop,
 526                         void *private)
 527 {
 528         int err;
 529
 530         err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
 531         if (err)
 532                 return err;
 533         fsnotify_create(dir, dentry);
 534         return 0;
 535 }
 536
 537 static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
 538                        umode_t mode,
 539                        const struct file_operations *i_fop,
 540                        void *private)
 541 {
 542         int err;
 543
 544         err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
 545         if (err)
 546                 return err;
 547         inc_nlink(dir);
 548         fsnotify_mkdir(dir, dentry);
 549         return 0;
 550 }
 551
 552 static void
 553 init_pipe(struct rpc_pipe *pipe)
 554 {
 555         pipe->nreaders = 0;
 556         pipe->nwriters = 0;
 557         INIT_LIST_HEAD(&pipe->in_upcall);
 558         INIT_LIST_HEAD(&pipe->in_downcall);
 559         INIT_LIST_HEAD(&pipe->pipe);
 560         pipe->pipelen = 0;
 561         init_waitqueue_head(&pipe->waitq);
 562         INIT_DELAYED_WORK(&pipe->queue_timeout,
 563                             rpc_timeout_upcall_queue);
 564         pipe->ops = NULL;
 565         spin_lock_init(&pipe->lock);
 566         pipe->dentry = NULL;
 567 }
 568
 569 void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
 570 {
 571         kfree(pipe);
 572 }
 573 EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
 574
 575 struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
 576 {
 577         struct rpc_pipe *pipe;
 578
 579         pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
 580         if (!pipe)
 581                 return ERR_PTR(-ENOMEM);
 582         init_pipe(pipe);
 583         pipe->ops = ops;
 584         pipe->flags = flags;
 585         return pipe;
 586 }
 587 EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
 588
 589 static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
 590                                umode_t mode,
 591                                const struct file_operations *i_fop,
 592                                void *private,
 593                                struct rpc_pipe *pipe)
 594 {
 595         struct rpc_inode *rpci;
 596         int err;
 597
 598         err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
 599         if (err)
 600                 return err;
 601         rpci = RPC_I(dentry->d_inode);
 602         rpci->private = private;
 603         rpci->pipe = pipe;
 604         fsnotify_create(dir, dentry);
 605         return 0;
 606 }
 607
 608 static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 609 {
 610         int ret;
 611
 612         dget(dentry);
 613         ret = simple_rmdir(dir, dentry);
 614         d_delete(dentry);
 615         dput(dentry);
 616         return ret;
 617 }
 618
 619 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
 620 {
 621         int ret;
 622
 623         dget(dentry);
 624         ret = simple_unlink(dir, dentry);
 625         d_delete(dentry);
 626         dput(dentry);
 627         return ret;
 628 }
 629
 630 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
 631 {
 632         struct inode *inode = dentry->d_inode;
 633
 634         rpc_close_pipes(inode);
 635         return __rpc_unlink(dir, dentry);
 636 }
 637
 638 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
 639                                           struct qstr *name)
 640 {
 641         struct dentry *dentry;
 642
 643         dentry = d_lookup(parent, name);
 644         if (!dentry) {
 645                 dentry = d_alloc(parent, name);
 646                 if (!dentry)
 647                         return ERR_PTR(-ENOMEM);
 648         }
 649         if (dentry->d_inode == NULL) {
 650                 d_set_d_op(dentry, &rpc_dentry_operations);
 651                 return dentry;
 652         }
 653         dput(dentry);
 654         return ERR_PTR(-EEXIST);
 655 }
 656
 657 /*
 658  * FIXME: This probably has races.
 659  */
 660 static void __rpc_depopulate(struct dentry *parent,
 661                              const struct rpc_filelist *files,
 662                              int start, int eof)
 663 {
 664         struct inode *dir = parent->d_inode;
 665         struct dentry *dentry;
 666         struct qstr name;
 667         int i;
 668
 669         for (i = start; i < eof; i++) {
 670                 name.name = files[i].name;
 671                 name.len = strlen(files[i].name);
 672                 name.hash = full_name_hash(name.name, name.len);
 673                 dentry = d_lookup(parent, &name);
 674
 675                 if (dentry == NULL)
 676                         continue;
 677                 if (dentry->d_inode == NULL)
 678                         goto next;
 679                 switch (dentry->d_inode->i_mode & S_IFMT) {
 680                         default:
 681                                 BUG();
 682                         case S_IFREG:
 683                                 __rpc_unlink(dir, dentry);
 684                                 break;
 685                         case S_IFDIR:
 686                                 __rpc_rmdir(dir, dentry);
 687                 }
 688 next:
 689                 dput(dentry);
 690         }
 691 }
 692
 693 static void rpc_depopulate(struct dentry *parent,
 694                            const struct rpc_filelist *files,
 695                            int start, int eof)
 696 {
 697         struct inode *dir = parent->d_inode;
 698
 699         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
 700         __rpc_depopulate(parent, files, start, eof);
 701         mutex_unlock(&dir->i_mutex);
 702 }
 703
 704 static int rpc_populate(struct dentry *parent,
 705                         const struct rpc_filelist *files,
 706                         int start, int eof,
 707                         void *private)
 708 {
 709         struct inode *dir = parent->d_inode;
 710         struct dentry *dentry;
 711         int i, err;
 712
 713         mutex_lock(&dir->i_mutex);
 714         for (i = start; i < eof; i++) {
 715                 struct qstr q;
 716
 717                 q.name = files[i].name;
 718                 q.len = strlen(files[i].name);
 719                 q.hash = full_name_hash(q.name, q.len);
 720                 dentry = __rpc_lookup_create_exclusive(parent, &q);
 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         mutex_unlock(&dir->i_mutex);
 743         return 0;
 744 out_bad:
 745         __rpc_depopulate(parent, files, start, eof);
 746         mutex_unlock(&dir->i_mutex);
 747         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
 748                         __FILE__, __func__, parent->d_name.name);
 749         return err;
 750 }
 751
 752 static struct dentry *rpc_mkdir_populate(struct dentry *parent,
 753                 struct qstr *name, umode_t mode, void *private,
 754                 int (*populate)(struct dentry *, void *), void *args_populate)
 755 {
 756         struct dentry *dentry;
 757         struct inode *dir = parent->d_inode;
 758         int error;
 759
 760         mutex_lock_nested(&dir->i_mutex, 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         mutex_unlock(&dir->i_mutex);
 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 = parent->d_inode;
 791         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 792         if (depopulate != NULL)
 793                 depopulate(dentry);
 794         error = __rpc_rmdir(dir, dentry);
 795         mutex_unlock(&dir->i_mutex);
 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  * @ops: operations defining the behavior of the pipe: upcall, downcall,
 806  *      release_pipe, open_pipe, and destroy_msg.
 807  * @flags: rpc_pipe flags
 808  *
 809  * Data is made available for userspace to read by calls to
 810  * rpc_queue_upcall().  The actual reads will result in calls to
 811  * @ops->upcall, which will be called with the file pointer,
 812  * message, and userspace buffer to copy to.
 813  *
 814  * Writes can come at any time, and do not necessarily have to be
 815  * responses to upcalls.  They will result in calls to @msg->downcall.
 816  *
 817  * The @private argument passed here will be available to all these methods
 818  * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private.
 819  */
 820 struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
 821                                  void *private, struct rpc_pipe *pipe)
 822 {
 823         struct dentry *dentry;
 824         struct inode *dir = parent->d_inode;
 825         umode_t umode = S_IFIFO | S_IRUSR | S_IWUSR;
 826         struct qstr q;
 827         int err;
 828
 829         if (pipe->ops->upcall == NULL)
 830                 umode &= ~S_IRUGO;
 831         if (pipe->ops->downcall == NULL)
 832                 umode &= ~S_IWUGO;
 833
 834         q.name = name;
 835         q.len = strlen(name);
 836         q.hash = full_name_hash(q.name, q.len),
 837
 838         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 839         dentry = __rpc_lookup_create_exclusive(parent, &q);
 840         if (IS_ERR(dentry))
 841                 goto out;
 842         err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
 843                                   private, pipe);
 844         if (err)
 845                 goto out_err;
 846 out:
 847         mutex_unlock(&dir->i_mutex);
 848         return dentry;
 849 out_err:
 850         dentry = ERR_PTR(err);
 851         printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
 852                         __FILE__, __func__, parent->d_name.name, name,
 853                         err);
 854         goto out;
 855 }
 856 EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
 857
 858 /**
 859  * rpc_unlink - remove a pipe
 860  * @dentry: dentry for the pipe, as returned from rpc_mkpipe
 861  *
 862  * After this call, lookups will no longer find the pipe, and any
 863  * attempts to read or write using preexisting opens of the pipe will
 864  * return -EPIPE.
 865  */
 866 int
 867 rpc_unlink(struct dentry *dentry)
 868 {
 869         struct dentry *parent;
 870         struct inode *dir;
 871         int error = 0;
 872
 873         parent = dget_parent(dentry);
 874         dir = parent->d_inode;
 875         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 876         error = __rpc_rmpipe(dir, dentry);
 877         mutex_unlock(&dir->i_mutex);
 878         dput(parent);
 879         return error;
 880 }
 881 EXPORT_SYMBOL_GPL(rpc_unlink);
 882
 883 enum {
 884         RPCAUTH_info,
 885         RPCAUTH_EOF
 886 };
 887
 888 static const struct rpc_filelist authfiles[] = {
 889         [RPCAUTH_info] = {
 890                 .name = "info",
 891                 .i_fop = &rpc_info_operations,
 892                 .mode = S_IFREG | S_IRUSR,
 893         },
 894 };
 895
 896 static int rpc_clntdir_populate(struct dentry *dentry, void *private)
 897 {
 898         return rpc_populate(dentry,
 899                             authfiles, RPCAUTH_info, RPCAUTH_EOF,
 900                             private);
 901 }
 902
 903 static void rpc_clntdir_depopulate(struct dentry *dentry)
 904 {
 905         rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
 906 }
 907
 908 /**
 909  * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
 910  * @dentry: dentry from the rpc_pipefs root to the new directory
 911  * @name: &struct qstr for the name
 912  * @rpc_client: rpc client to associate with this directory
 913  *
 914  * This creates a directory at the given @path associated with
 915  * @rpc_clnt, which will contain a file named "info" with some basic
 916  * information about the client, together with any "pipes" that may
 917  * later be created using rpc_mkpipe().
 918  */
 919 struct dentry *rpc_create_client_dir(struct dentry *dentry,
 920                                    struct qstr *name,
 921                                    struct rpc_clnt *rpc_client)
 922 {
 923         return rpc_mkdir_populate(dentry, name, S_IRUGO | S_IXUGO, NULL,
 924                         rpc_clntdir_populate, rpc_client);
 925 }
 926
 927 /**
 928  * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
 929  * @clnt: rpc client
 930  */
 931 int rpc_remove_client_dir(struct dentry *dentry)
 932 {
 933         return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
 934 }
 935
 936 static const struct rpc_filelist cache_pipefs_files[3] = {
 937         [0] = {
 938                 .name = "channel",
 939                 .i_fop = &cache_file_operations_pipefs,
 940                 .mode = S_IFREG|S_IRUSR|S_IWUSR,
 941         },
 942         [1] = {
 943                 .name = "content",
 944                 .i_fop = &content_file_operations_pipefs,
 945                 .mode = S_IFREG|S_IRUSR,
 946         },
 947         [2] = {
 948                 .name = "flush",
 949                 .i_fop = &cache_flush_operations_pipefs,
 950                 .mode = S_IFREG|S_IRUSR|S_IWUSR,
 951         },
 952 };
 953
 954 static int rpc_cachedir_populate(struct dentry *dentry, void *private)
 955 {
 956         return rpc_populate(dentry,
 957                             cache_pipefs_files, 0, 3,
 958                             private);
 959 }
 960
 961 static void rpc_cachedir_depopulate(struct dentry *dentry)
 962 {
 963         rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
 964 }
 965
 966 struct dentry *rpc_create_cache_dir(struct dentry *parent, struct qstr *name,
 967                                     umode_t umode, struct cache_detail *cd)
 968 {
 969         return rpc_mkdir_populate(parent, name, umode, NULL,
 970                         rpc_cachedir_populate, cd);
 971 }
 972
 973 void rpc_remove_cache_dir(struct dentry *dentry)
 974 {
 975         rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
 976 }
 977
 978 /*
 979  * populate the filesystem
 980  */
 981 static const struct super_operations s_ops = {
 982         .alloc_inode    = rpc_alloc_inode,
 983         .destroy_inode  = rpc_destroy_inode,
 984         .statfs         = simple_statfs,
 985 };
 986
 987 #define RPCAUTH_GSSMAGIC 0x67596969
 988
 989 /*
 990  * We have a single directory with 1 node in it.
 991  */
 992 enum {
 993         RPCAUTH_lockd,
 994         RPCAUTH_mount,
 995         RPCAUTH_nfs,
 996         RPCAUTH_portmap,
 997         RPCAUTH_statd,
 998         RPCAUTH_nfsd4_cb,
 999         RPCAUTH_cache,
1000         RPCAUTH_RootEOF
1001 };
1002
1003 static const struct rpc_filelist files[] = {
1004         [RPCAUTH_lockd] = {
1005                 .name = "lockd",
1006                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1007         },
1008         [RPCAUTH_mount] = {
1009                 .name = "mount",
1010                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1011         },
1012         [RPCAUTH_nfs] = {
1013                 .name = "nfs",
1014                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1015         },
1016         [RPCAUTH_portmap] = {
1017                 .name = "portmap",
1018                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1019         },
1020         [RPCAUTH_statd] = {
1021                 .name = "statd",
1022                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1023         },
1024         [RPCAUTH_nfsd4_cb] = {
1025                 .name = "nfsd4_cb",
1026                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1027         },
1028         [RPCAUTH_cache] = {
1029                 .name = "cache",
1030                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1031         },
1032 };
1033
1034 /*
1035  * This call can be used only in RPC pipefs mount notification hooks.
1036  */
1037 struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1038                                const unsigned char *dir_name)
1039 {
1040         struct qstr dir = {
1041                 .name = dir_name,
1042                 .len = strlen(dir_name),
1043                 .hash = full_name_hash(dir_name, strlen(dir_name)),
1044         };
1045
1046         return d_lookup(sb->s_root, &dir);
1047 }
1048 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1049
1050 void rpc_pipefs_init_net(struct net *net)
1051 {
1052         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1053
1054         mutex_init(&sn->pipefs_sb_lock);
1055 }
1056
1057 /*
1058  * This call will be used for per network namespace operations calls.
1059  * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1060  * found. This lock have to be released by rpc_put_sb_net() when all operations
1061  * will be completed.
1062  */
1063 struct super_block *rpc_get_sb_net(const struct net *net)
1064 {
1065         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1066
1067         mutex_lock(&sn->pipefs_sb_lock);
1068         if (sn->pipefs_sb)
1069                 return sn->pipefs_sb;
1070         mutex_unlock(&sn->pipefs_sb_lock);
1071         return NULL;
1072 }
1073 EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1074
1075 void rpc_put_sb_net(const struct net *net)
1076 {
1077         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1078
1079         BUG_ON(sn->pipefs_sb == NULL);
1080         mutex_unlock(&sn->pipefs_sb_lock);
1081 }
1082 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1083
1084 static int
1085 rpc_fill_super(struct super_block *sb, void *data, int silent)
1086 {
1087         struct inode *inode;
1088         struct dentry *root;
1089         struct net *net = data;
1090         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1091         int err;
1092
1093         sb->s_blocksize = PAGE_CACHE_SIZE;
1094         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1095         sb->s_magic = RPCAUTH_GSSMAGIC;
1096         sb->s_op = &s_ops;
1097         sb->s_time_gran = 1;
1098
1099         inode = rpc_get_inode(sb, S_IFDIR | 0755);
1100         if (!inode)
1101                 return -ENOMEM;
1102         sb->s_root = root = d_alloc_root(inode);
1103         if (!root) {
1104                 iput(inode);
1105                 return -ENOMEM;
1106         }
1107         if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1108                 return -ENOMEM;
1109         dprintk("RPC:   sending pipefs MOUNT notification for net %p%s\n", net,
1110                                                                 NET_NAME(net));
1111         err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1112                                            RPC_PIPEFS_MOUNT,
1113                                            sb);
1114         if (err)
1115                 goto err_depopulate;
1116         sb->s_fs_info = get_net(net);
1117         sn->pipefs_sb = sb;
1118         return 0;
1119
1120 err_depopulate:
1121         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1122                                            RPC_PIPEFS_UMOUNT,
1123                                            sb);
1124         __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1125         return err;
1126 }
1127
1128 static struct dentry *
1129 rpc_mount(struct file_system_type *fs_type,
1130                 int flags, const char *dev_name, void *data)
1131 {
1132         return mount_ns(fs_type, flags, current->nsproxy->net_ns, rpc_fill_super);
1133 }
1134
1135 void rpc_kill_sb(struct super_block *sb)
1136 {
1137         struct net *net = sb->s_fs_info;
1138         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1139
1140         mutex_lock(&sn->pipefs_sb_lock);
1141         sn->pipefs_sb = NULL;
1142         mutex_unlock(&sn->pipefs_sb_lock);
1143         put_net(net);
1144         dprintk("RPC:   sending pipefs UMOUNT notification for net %p%s\n", net,
1145                                                                 NET_NAME(net));
1146         blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1147                                            RPC_PIPEFS_UMOUNT,
1148                                            sb);
1149         kill_litter_super(sb);
1150 }
1151
1152 static struct file_system_type rpc_pipe_fs_type = {
1153         .owner          = THIS_MODULE,
1154         .name           = "rpc_pipefs",
1155         .mount          = rpc_mount,
1156         .kill_sb        = rpc_kill_sb,
1157 };
1158
1159 static void
1160 init_once(void *foo)
1161 {
1162         struct rpc_inode *rpci = (struct rpc_inode *) foo;
1163
1164         inode_init_once(&rpci->vfs_inode);
1165         rpci->private = NULL;
1166         rpci->pipe = NULL;
1167 }
1168
1169 int register_rpc_pipefs(void)
1170 {
1171         int err;
1172
1173         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1174                                 sizeof(struct rpc_inode),
1175                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1176                                                 SLAB_MEM_SPREAD),
1177                                 init_once);
1178         if (!rpc_inode_cachep)
1179                 return -ENOMEM;
1180         err = rpc_clients_notifier_register();
1181         if (err)
1182                 goto err_notifier;
1183         err = register_filesystem(&rpc_pipe_fs_type);
1184         if (err)
1185                 goto err_register;
1186         return 0;
1187
1188 err_register:
1189         rpc_clients_notifier_unregister();
1190 err_notifier:
1191         kmem_cache_destroy(rpc_inode_cachep);
1192         return err;
1193 }
1194
1195 void unregister_rpc_pipefs(void)
1196 {
1197         rpc_clients_notifier_unregister();
1198         kmem_cache_destroy(rpc_inode_cachep);
1199         unregister_filesystem(&rpc_pipe_fs_type);
1200 }
1201
1202 /* Make 'mount -t rpc_pipefs ...' autoload this module. */
1203 MODULE_ALIAS("rpc_pipefs");