linux/net/sunrpc/rpc_pipe.c
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   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
  41static struct file_system_type rpc_pipe_fs_type;
  42static const struct rpc_pipe_ops gssd_dummy_pipe_ops;
  43
  44static struct kmem_cache *rpc_inode_cachep __read_mostly;
  45
  46#define RPC_UPCALL_TIMEOUT (30*HZ)
  47
  48static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
  49
  50int rpc_pipefs_notifier_register(struct notifier_block *nb)
  51{
  52        return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
  53}
  54EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
  55
  56void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
  57{
  58        blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
  59}
  60EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
  61
  62static 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
  80static void
  81rpc_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(dentry->d_inode)->waitq : NULL,
  98                        &free_list, destroy_msg, -ETIMEDOUT);
  99        dput(dentry);
 100}
 101
 102ssize_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}
 120EXPORT_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 */
 132int
 133rpc_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(dentry->d_inode)->waitq);
 156                dput(dentry);
 157        }
 158        return res;
 159}
 160EXPORT_SYMBOL_GPL(rpc_queue_upcall);
 161
 162static inline void
 163rpc_inode_setowner(struct inode *inode, void *private)
 164{
 165        RPC_I(inode)->private = private;
 166}
 167
 168static void
 169rpc_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        mutex_lock(&inode->i_mutex);
 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        mutex_unlock(&inode->i_mutex);
 192}
 193
 194static struct inode *
 195rpc_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
 204static void
 205rpc_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
 211static void
 212rpc_destroy_inode(struct inode *inode)
 213{
 214        call_rcu(&inode->i_rcu, rpc_i_callback);
 215}
 216
 217static int
 218rpc_pipe_open(struct inode *inode, struct file *filp)
 219{
 220        struct rpc_pipe *pipe;
 221        int first_open;
 222        int res = -ENXIO;
 223
 224        mutex_lock(&inode->i_mutex);
 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;
 239out:
 240        mutex_unlock(&inode->i_mutex);
 241        return res;
 242}
 243
 244static int
 245rpc_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        mutex_lock(&inode->i_mutex);
 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);
 280out:
 281        mutex_unlock(&inode->i_mutex);
 282        return 0;
 283}
 284
 285static ssize_t
 286rpc_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        mutex_lock(&inode->i_mutex);
 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        }
 324out_unlock:
 325        mutex_unlock(&inode->i_mutex);
 326        return res;
 327}
 328
 329static ssize_t
 330rpc_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        mutex_lock(&inode->i_mutex);
 336        res = -EPIPE;
 337        if (RPC_I(inode)->pipe != NULL)
 338                res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
 339        mutex_unlock(&inode->i_mutex);
 340        return res;
 341}
 342
 343static unsigned int
 344rpc_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        mutex_lock(&inode->i_mutex);
 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        mutex_unlock(&inode->i_mutex);
 358        return mask;
 359}
 360
 361static long
 362rpc_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                mutex_lock(&inode->i_mutex);
 371                pipe = RPC_I(inode)->pipe;
 372                if (pipe == NULL) {
 373                        mutex_unlock(&inode->i_mutex);
 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                mutex_unlock(&inode->i_mutex);
 385                return put_user(len, (int __user *)arg);
 386        default:
 387                return -EINVAL;
 388        }
 389}
 390
 391static 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
 402static int
 403rpc_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
 419static int
 420rpc_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
 443static int
 444rpc_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
 454static 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 */
 466struct rpc_filelist {
 467        const char *name;
 468        const struct file_operations *i_fop;
 469        umode_t mode;
 470};
 471
 472static struct inode *
 473rpc_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
 492static 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;
 510out_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
 517static 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
 531static 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
 546static void
 547init_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
 562void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
 563{
 564        kfree(pipe);
 565}
 566EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
 567
 568struct 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}
 580EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
 581
 582static 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(dentry->d_inode);
 595        rpci->private = private;
 596        rpci->pipe = pipe;
 597        fsnotify_create(dir, dentry);
 598        return 0;
 599}
 600
 601static 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
 612int 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 = parent->d_inode;
 620        mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 621        error = __rpc_rmdir(dir, dentry);
 622        mutex_unlock(&dir->i_mutex);
 623        dput(parent);
 624        return error;
 625}
 626EXPORT_SYMBOL_GPL(rpc_rmdir);
 627
 628static 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
 639static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
 640{
 641        struct inode *inode = dentry->d_inode;
 642
 643        rpc_close_pipes(inode);
 644        return __rpc_unlink(dir, dentry);
 645}
 646
 647static 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 (dentry->d_inode == NULL)
 658                return dentry;
 659        dput(dentry);
 660        return ERR_PTR(-EEXIST);
 661}
 662
 663/*
 664 * FIXME: This probably has races.
 665 */
 666static void __rpc_depopulate(struct dentry *parent,
 667                             const struct rpc_filelist *files,
 668                             int start, int eof)
 669{
 670        struct inode *dir = parent->d_inode;
 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 (dentry->d_inode == NULL)
 683                        goto next;
 684                switch (dentry->d_inode->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                }
 693next:
 694                dput(dentry);
 695        }
 696}
 697
 698static void rpc_depopulate(struct dentry *parent,
 699                           const struct rpc_filelist *files,
 700                           int start, int eof)
 701{
 702        struct inode *dir = parent->d_inode;
 703
 704        mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
 705        __rpc_depopulate(parent, files, start, eof);
 706        mutex_unlock(&dir->i_mutex);
 707}
 708
 709static 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 = parent->d_inode;
 715        struct dentry *dentry;
 716        int i, err;
 717
 718        mutex_lock(&dir->i_mutex);
 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        mutex_unlock(&dir->i_mutex);
 743        return 0;
 744out_bad:
 745        __rpc_depopulate(parent, files, start, eof);
 746        mutex_unlock(&dir->i_mutex);
 747        printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
 748                        __FILE__, __func__, parent);
 749        return err;
 750}
 751
 752static 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 = 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        }
 772out:
 773        mutex_unlock(&dir->i_mutex);
 774        return dentry;
 775err_rmdir:
 776        __rpc_rmdir(dir, dentry);
 777out_err:
 778        dentry = ERR_PTR(error);
 779        goto out;
 780}
 781
 782static 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 * @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 */
 818struct 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 = parent->d_inode;
 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        mutex_lock_nested(&dir->i_mutex, 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;
 839out:
 840        mutex_unlock(&dir->i_mutex);
 841        return dentry;
 842out_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}
 849EXPORT_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 */
 859int
 860rpc_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 = parent->d_inode;
 868        mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 869        error = __rpc_rmpipe(dir, dentry);
 870        mutex_unlock(&dir->i_mutex);
 871        dput(parent);
 872        return error;
 873}
 874EXPORT_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 */
 880void 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}
 885EXPORT_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 */
 893void 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}
 901EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
 902
 903static int
 904rpc_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
 917static void
 918rpc_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 */
 934int
 935rpc_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}
 950EXPORT_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 */
 959void
 960rpc_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}
 972EXPORT_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 */
 983struct rpc_pipe_dir_object *
 984rpc_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);
1003out:
1004        mutex_unlock(&sn->pipefs_sb_lock);
1005        return pdo;
1006}
1007EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
1008
1009static void
1010rpc_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
1019static void
1020rpc_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
1029enum {
1030        RPCAUTH_info,
1031        RPCAUTH_EOF
1032};
1033
1034static 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
1042static 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
1049static 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 */
1065struct 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 */
1084int 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
1095static 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
1113static 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
1120static void rpc_cachedir_depopulate(struct dentry *dentry)
1121{
1122        rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
1123}
1124
1125struct 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
1132void rpc_remove_cache_dir(struct dentry *dentry)
1133{
1134        rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
1135}
1136
1137/*
1138 * populate the filesystem
1139 */
1140static 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 */
1151enum {
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
1164static 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 */
1206struct 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}
1212EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1213
1214int 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
1227void 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 */
1240struct 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}
1250EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1251
1252void 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}
1259EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1260
1261static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
1262        [0] = {
1263                .name = "clntXX",
1264                .mode = S_IFDIR | S_IRUGO | S_IXUGO,
1265        },
1266};
1267
1268static ssize_t
1269dummy_downcall(struct file *filp, const char __user *src, size_t len)
1270{
1271        return -EINVAL;
1272}
1273
1274static 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 */
1284static int
1285rpc_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
1295static int
1296rpc_dummy_info_open(struct inode *inode, struct file *file)
1297{
1298        return single_open(file, rpc_show_dummy_info, NULL);
1299}
1300
1301static 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
1309static 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 */
1325static struct dentry *
1326rpc_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        }
1366out:
1367        dput(clnt_dentry);
1368        dput(gssd_dentry);
1369        return pipe_dentry;
1370}
1371
1372static void
1373rpc_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(clnt_dir->d_inode, 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
1384static int
1385rpc_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_CACHE_SIZE;
1394        sb->s_blocksize_bits = PAGE_CACHE_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
1426err_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
1437bool
1438gssd_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}
1445EXPORT_SYMBOL_GPL(gssd_running);
1446
1447static struct dentry *
1448rpc_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
1454static 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);
1472out:
1473        kill_litter_super(sb);
1474}
1475
1476static 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};
1482MODULE_ALIAS_FS("rpc_pipefs");
1483MODULE_ALIAS("rpc_pipefs");
1484
1485static void
1486init_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
1496int 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),
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
1515err_register:
1516        rpc_clients_notifier_unregister();
1517err_notifier:
1518        kmem_cache_destroy(rpc_inode_cachep);
1519        return err;
1520}
1521
1522void 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}
1528