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   1 /*
   2  * linux/fs/9p/trans_fd.c
   3  *
   4  * Fd transport layer.  Includes deprecated socket layer.
   5  *
   6  *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
   7  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
   8  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
   9  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License version 2
  13  *  as published by the Free Software Foundation.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to:
  22  *  Free Software Foundation
  23  *  51 Franklin Street, Fifth Floor
  24  *  Boston, MA  02111-1301  USA
  25  *
  26  */
  27
  28 #include <linux/in.h>
  29 #include <linux/module.h>
  30 #include <linux/net.h>
  31 #include <linux/ipv6.h>
  32 #include <linux/kthread.h>
  33 #include <linux/errno.h>
  34 #include <linux/kernel.h>
  35 #include <linux/un.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/inet.h>
  38 #include <linux/idr.h>
  39 #include <linux/file.h>
  40 #include <linux/parser.h>
  41 #include <net/9p/9p.h>
  42 #include <net/9p/client.h>
  43 #include <net/9p/transport.h>
  44
  45 #define P9_PORT 564
  46 #define MAX_SOCK_BUF (64*1024)
  47 #define ERREQFLUSH      1
  48 #define MAXPOLLWADDR    2
  49
  50 /**
  51  * struct p9_fd_opts - per-transport options
  52  * @rfd: file descriptor for reading (trans=fd)
  53  * @wfd: file descriptor for writing (trans=fd)
  54  * @port: port to connect to (trans=tcp)
  55  *
  56  */
  57
  58 struct p9_fd_opts {
  59         int rfd;
  60         int wfd;
  61         u16 port;
  62 };
  63
  64 /**
  65  * struct p9_trans_fd - transport state
  66  * @rd: reference to file to read from
  67  * @wr: reference of file to write to
  68  * @conn: connection state reference
  69  *
  70  */
  71
  72 struct p9_trans_fd {
  73         struct file *rd;
  74         struct file *wr;
  75         struct p9_conn *conn;
  76 };
  77
  78 /*
  79   * Option Parsing (code inspired by NFS code)
  80   *  - a little lazy - parse all fd-transport options
  81   */
  82
  83 enum {
  84         /* Options that take integer arguments */
  85         Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
  86 };
  87
  88 static const match_table_t tokens = {
  89         {Opt_port, "port=%u"},
  90         {Opt_rfdno, "rfdno=%u"},
  91         {Opt_wfdno, "wfdno=%u"},
  92         {Opt_err, NULL},
  93 };
  94
  95 enum {
  96         Rworksched = 1,         /* read work scheduled or running */
  97         Rpending = 2,           /* can read */
  98         Wworksched = 4,         /* write work scheduled or running */
  99         Wpending = 8,           /* can write */
 100 };
 101
 102 enum {
 103         None,
 104         Flushing,
 105         Flushed,
 106 };
 107
 108 /**
 109  * struct p9_req - fd mux encoding of an rpc transaction
 110  * @lock: protects req_list
 111  * @tag: numeric tag for rpc transaction
 112  * @tcall: request &p9_fcall structure
 113  * @rcall: response &p9_fcall structure
 114  * @err: error state
 115  * @flush: flag to indicate RPC has been flushed
 116  * @req_list: list link for higher level objects to chain requests
 117  * @m: connection this request was issued on
 118  * @wqueue: wait queue that client is blocked on for this rpc
 119  *
 120  */
 121
 122 struct p9_req {
 123         spinlock_t lock;
 124         int tag;
 125         struct p9_fcall *tcall;
 126         struct p9_fcall *rcall;
 127         int err;
 128         int flush;
 129         struct list_head req_list;
 130         struct p9_conn *m;
 131         wait_queue_head_t wqueue;
 132 };
 133
 134 struct p9_poll_wait {
 135         struct p9_conn *conn;
 136         wait_queue_t wait;
 137         wait_queue_head_t *wait_addr;
 138 };
 139
 140 /**
 141  * struct p9_conn - fd mux connection state information
 142  * @lock: protects mux_list (?)
 143  * @mux_list: list link for mux to manage multiple connections (?)
 144  * @client: reference to client instance for this connection
 145  * @tagpool: id accounting for transactions
 146  * @err: error state
 147  * @req_list: accounting for requests which have been sent
 148  * @unsent_req_list: accounting for requests that haven't been sent
 149  * @rcall: current response &p9_fcall structure
 150  * @rpos: read position in current frame
 151  * @rbuf: current read buffer
 152  * @wpos: write position for current frame
 153  * @wsize: amount of data to write for current frame
 154  * @wbuf: current write buffer
 155  * @poll_wait: array of wait_q's for various worker threads
 156  * @poll_waddr: ????
 157  * @pt: poll state
 158  * @rq: current read work
 159  * @wq: current write work
 160  * @wsched: ????
 161  *
 162  */
 163
 164 struct p9_conn {
 165         spinlock_t lock; /* protect lock structure */
 166         struct list_head mux_list;
 167         struct p9_client *client;
 168         struct p9_idpool *tagpool;
 169         int err;
 170         struct list_head req_list;
 171         struct list_head unsent_req_list;
 172         struct p9_fcall *rcall;
 173         int rpos;
 174         char *rbuf;
 175         int wpos;
 176         int wsize;
 177         char *wbuf;
 178         struct list_head poll_pending_link;
 179         struct p9_poll_wait poll_wait[MAXPOLLWADDR];
 180         poll_table pt;
 181         struct work_struct rq;
 182         struct work_struct wq;
 183         unsigned long wsched;
 184 };
 185
 186 static DEFINE_SPINLOCK(p9_poll_lock);
 187 static LIST_HEAD(p9_poll_pending_list);
 188 static struct workqueue_struct *p9_mux_wq;
 189 static struct task_struct *p9_poll_task;
 190
 191 static u16 p9_mux_get_tag(struct p9_conn *m)
 192 {
 193         int tag;
 194
 195         tag = p9_idpool_get(m->tagpool);
 196         if (tag < 0)
 197                 return P9_NOTAG;
 198         else
 199                 return (u16) tag;
 200 }
 201
 202 static void p9_mux_put_tag(struct p9_conn *m, u16 tag)
 203 {
 204         if (tag != P9_NOTAG && p9_idpool_check(tag, m->tagpool))
 205                 p9_idpool_put(tag, m->tagpool);
 206 }
 207
 208 static void p9_mux_poll_stop(struct p9_conn *m)
 209 {
 210         unsigned long flags;
 211         int i;
 212
 213         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 214                 struct p9_poll_wait *pwait = &m->poll_wait[i];
 215
 216                 if (pwait->wait_addr) {
 217                         remove_wait_queue(pwait->wait_addr, &pwait->wait);
 218                         pwait->wait_addr = NULL;
 219                 }
 220         }
 221
 222         spin_lock_irqsave(&p9_poll_lock, flags);
 223         list_del_init(&m->poll_pending_link);
 224         spin_unlock_irqrestore(&p9_poll_lock, flags);
 225 }
 226
 227 static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req)
 228 {
 229         p9_mux_put_tag(m, req->tag);
 230         kfree(req);
 231 }
 232
 233 static void p9_conn_rpc_cb(struct p9_req *req);
 234
 235 static void p9_mux_flush_cb(struct p9_req *freq)
 236 {
 237         int tag;
 238         struct p9_conn *m = freq->m;
 239         struct p9_req *req, *rreq, *rptr;
 240
 241         P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m,
 242                 freq->tcall, freq->rcall, freq->err,
 243                 freq->tcall->params.tflush.oldtag);
 244
 245         spin_lock(&m->lock);
 246         tag = freq->tcall->params.tflush.oldtag;
 247         req = NULL;
 248         list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
 249                 if (rreq->tag == tag) {
 250                         req = rreq;
 251                         list_del(&req->req_list);
 252                         break;
 253                 }
 254         }
 255         spin_unlock(&m->lock);
 256
 257         if (req) {
 258                 spin_lock(&req->lock);
 259                 req->flush = Flushed;
 260                 spin_unlock(&req->lock);
 261
 262                 p9_conn_rpc_cb(req);
 263         }
 264
 265         kfree(freq->tcall);
 266         kfree(freq->rcall);
 267         p9_mux_free_request(m, freq);
 268 }
 269
 270 static void p9_conn_rpc_cb(struct p9_req *req)
 271 {
 272         P9_DPRINTK(P9_DEBUG_MUX, "req %p\n", req);
 273
 274         if (req->tcall->id == P9_TFLUSH) { /* flush callback */
 275                 P9_DPRINTK(P9_DEBUG_MUX, "flush req %p\n", req);
 276                 p9_mux_flush_cb(req);
 277         } else {                        /* normal wakeup path */
 278                 P9_DPRINTK(P9_DEBUG_MUX, "normal req %p\n", req);
 279                 if (req->flush != None && !req->err)
 280                         req->err = -ERESTARTSYS;
 281
 282                 wake_up(&req->wqueue);
 283         }
 284 }
 285
 286 /**
 287  * p9_conn_cancel - cancel all pending requests with error
 288  * @m: mux data
 289  * @err: error code
 290  *
 291  */
 292
 293 void p9_conn_cancel(struct p9_conn *m, int err)
 294 {
 295         struct p9_req *req, *rtmp;
 296         LIST_HEAD(cancel_list);
 297
 298         P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
 299         m->err = err;
 300         spin_lock(&m->lock);
 301         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
 302                 list_move(&req->req_list, &cancel_list);
 303         }
 304         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
 305                 list_move(&req->req_list, &cancel_list);
 306         }
 307         spin_unlock(&m->lock);
 308
 309         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
 310                 list_del(&req->req_list);
 311                 if (!req->err)
 312                         req->err = err;
 313
 314                 p9_conn_rpc_cb(req);
 315         }
 316 }
 317
 318 static void process_request(struct p9_conn *m, struct p9_req *req)
 319 {
 320         int ecode;
 321         struct p9_str *ename;
 322
 323         if (!req->err && req->rcall->id == P9_RERROR) {
 324                 ecode = req->rcall->params.rerror.errno;
 325                 ename = &req->rcall->params.rerror.error;
 326
 327                 P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
 328                                                                 ename->str);
 329
 330                 if (m->client->dotu)
 331                         req->err = -ecode;
 332
 333                 if (!req->err) {
 334                         req->err = p9_errstr2errno(ename->str, ename->len);
 335
 336                         /* string match failed */
 337                         if (!req->err) {
 338                                 PRINT_FCALL_ERROR("unknown error", req->rcall);
 339                                 req->err = -ESERVERFAULT;
 340                         }
 341                 }
 342         } else if (req->tcall && req->rcall->id != req->tcall->id + 1) {
 343                 P9_DPRINTK(P9_DEBUG_ERROR,
 344                                 "fcall mismatch: expected %d, got %d\n",
 345                                 req->tcall->id + 1, req->rcall->id);
 346                 if (!req->err)
 347                         req->err = -EIO;
 348         }
 349 }
 350
 351 static unsigned int
 352 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
 353 {
 354         int ret, n;
 355         struct p9_trans_fd *ts = NULL;
 356
 357         if (client && client->status == Connected)
 358                 ts = client->trans;
 359
 360         if (!ts)
 361                 return -EREMOTEIO;
 362
 363         if (!ts->rd->f_op || !ts->rd->f_op->poll)
 364                 return -EIO;
 365
 366         if (!ts->wr->f_op || !ts->wr->f_op->poll)
 367                 return -EIO;
 368
 369         ret = ts->rd->f_op->poll(ts->rd, pt);
 370         if (ret < 0)
 371                 return ret;
 372
 373         if (ts->rd != ts->wr) {
 374                 n = ts->wr->f_op->poll(ts->wr, pt);
 375                 if (n < 0)
 376                         return n;
 377                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
 378         }
 379
 380         return ret;
 381 }
 382
 383 /**
 384  * p9_fd_read- read from a fd
 385  * @client: client instance
 386  * @v: buffer to receive data into
 387  * @len: size of receive buffer
 388  *
 389  */
 390
 391 static int p9_fd_read(struct p9_client *client, void *v, int len)
 392 {
 393         int ret;
 394         struct p9_trans_fd *ts = NULL;
 395
 396         if (client && client->status != Disconnected)
 397                 ts = client->trans;
 398
 399         if (!ts)
 400                 return -EREMOTEIO;
 401
 402         if (!(ts->rd->f_flags & O_NONBLOCK))
 403                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
 404
 405         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
 406         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 407                 client->status = Disconnected;
 408         return ret;
 409 }
 410
 411 /**
 412  * p9_read_work - called when there is some data to be read from a transport
 413  * @work: container of work to be done
 414  *
 415  */
 416
 417 static void p9_read_work(struct work_struct *work)
 418 {
 419         int n, err;
 420         struct p9_conn *m;
 421         struct p9_req *req, *rptr, *rreq;
 422         struct p9_fcall *rcall;
 423         char *rbuf;
 424
 425         m = container_of(work, struct p9_conn, rq);
 426
 427         if (m->err < 0)
 428                 return;
 429
 430         rcall = NULL;
 431         P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
 432
 433         if (!m->rcall) {
 434                 m->rcall =
 435                     kmalloc(sizeof(struct p9_fcall) + m->client->msize,
 436                                                                 GFP_KERNEL);
 437                 if (!m->rcall) {
 438                         err = -ENOMEM;
 439                         goto error;
 440                 }
 441
 442                 m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
 443                 m->rpos = 0;
 444         }
 445
 446         clear_bit(Rpending, &m->wsched);
 447         err = p9_fd_read(m->client, m->rbuf + m->rpos,
 448                                                 m->client->msize - m->rpos);
 449         P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err);
 450         if (err == -EAGAIN) {
 451                 clear_bit(Rworksched, &m->wsched);
 452                 return;
 453         }
 454
 455         if (err <= 0)
 456                 goto error;
 457
 458         m->rpos += err;
 459         while (m->rpos > 4) {
 460                 n = le32_to_cpu(*(__le32 *) m->rbuf);
 461                 if (n >= m->client->msize) {
 462                         P9_DPRINTK(P9_DEBUG_ERROR,
 463                                 "requested packet size too big: %d\n", n);
 464                         err = -EIO;
 465                         goto error;
 466                 }
 467
 468                 if (m->rpos < n)
 469                         break;
 470
 471                 err =
 472                     p9_deserialize_fcall(m->rbuf, n, m->rcall, m->client->dotu);
 473                 if (err < 0)
 474                         goto error;
 475
 476 #ifdef CONFIG_NET_9P_DEBUG
 477                 if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
 478                         char buf[150];
 479
 480                         p9_printfcall(buf, sizeof(buf), m->rcall,
 481                                 m->client->dotu);
 482                         printk(KERN_NOTICE ">>> %p %s\n", m, buf);
 483                 }
 484 #endif
 485
 486                 rcall = m->rcall;
 487                 rbuf = m->rbuf;
 488                 if (m->rpos > n) {
 489                         m->rcall = kmalloc(sizeof(struct p9_fcall) +
 490                                                 m->client->msize, GFP_KERNEL);
 491                         if (!m->rcall) {
 492                                 err = -ENOMEM;
 493                                 goto error;
 494                         }
 495
 496                         m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
 497                         memmove(m->rbuf, rbuf + n, m->rpos - n);
 498                         m->rpos -= n;
 499                 } else {
 500                         m->rcall = NULL;
 501                         m->rbuf = NULL;
 502                         m->rpos = 0;
 503                 }
 504
 505                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m,
 506                                                         rcall->id, rcall->tag);
 507
 508                 req = NULL;
 509                 spin_lock(&m->lock);
 510                 list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
 511                         if (rreq->tag == rcall->tag) {
 512                                 req = rreq;
 513                                 if (req->flush != Flushing)
 514                                         list_del(&req->req_list);
 515                                 break;
 516                         }
 517                 }
 518                 spin_unlock(&m->lock);
 519
 520                 if (req) {
 521                         req->rcall = rcall;
 522                         process_request(m, req);
 523
 524                         if (req->flush != Flushing)
 525                                 p9_conn_rpc_cb(req);
 526                 } else {
 527                         if (err >= 0 && rcall->id != P9_RFLUSH)
 528                                 P9_DPRINTK(P9_DEBUG_ERROR,
 529                                   "unexpected response mux %p id %d tag %d\n",
 530                                   m, rcall->id, rcall->tag);
 531                         kfree(rcall);
 532                 }
 533         }
 534
 535         if (!list_empty(&m->req_list)) {
 536                 if (test_and_clear_bit(Rpending, &m->wsched))
 537                         n = POLLIN;
 538                 else
 539                         n = p9_fd_poll(m->client, NULL);
 540
 541                 if (n & POLLIN) {
 542                         P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
 543                         queue_work(p9_mux_wq, &m->rq);
 544                 } else
 545                         clear_bit(Rworksched, &m->wsched);
 546         } else
 547                 clear_bit(Rworksched, &m->wsched);
 548
 549         return;
 550
 551 error:
 552         p9_conn_cancel(m, err);
 553         clear_bit(Rworksched, &m->wsched);
 554 }
 555
 556 /**
 557  * p9_fd_write - write to a socket
 558  * @client: client instance
 559  * @v: buffer to send data from
 560  * @len: size of send buffer
 561  *
 562  */
 563
 564 static int p9_fd_write(struct p9_client *client, void *v, int len)
 565 {
 566         int ret;
 567         mm_segment_t oldfs;
 568         struct p9_trans_fd *ts = NULL;
 569
 570         if (client && client->status != Disconnected)
 571                 ts = client->trans;
 572
 573         if (!ts)
 574                 return -EREMOTEIO;
 575
 576         if (!(ts->wr->f_flags & O_NONBLOCK))
 577                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
 578
 579         oldfs = get_fs();
 580         set_fs(get_ds());
 581         /* The cast to a user pointer is valid due to the set_fs() */
 582         ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
 583         set_fs(oldfs);
 584
 585         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 586                 client->status = Disconnected;
 587         return ret;
 588 }
 589
 590 /**
 591  * p9_write_work - called when a transport can send some data
 592  * @work: container for work to be done
 593  *
 594  */
 595
 596 static void p9_write_work(struct work_struct *work)
 597 {
 598         int n, err;
 599         struct p9_conn *m;
 600         struct p9_req *req;
 601
 602         m = container_of(work, struct p9_conn, wq);
 603
 604         if (m->err < 0) {
 605                 clear_bit(Wworksched, &m->wsched);
 606                 return;
 607         }
 608
 609         if (!m->wsize) {
 610                 if (list_empty(&m->unsent_req_list)) {
 611                         clear_bit(Wworksched, &m->wsched);
 612                         return;
 613                 }
 614
 615                 spin_lock(&m->lock);
 616 again:
 617                 req = list_entry(m->unsent_req_list.next, struct p9_req,
 618                                req_list);
 619                 list_move_tail(&req->req_list, &m->req_list);
 620                 if (req->err == ERREQFLUSH)
 621                         goto again;
 622
 623                 m->wbuf = req->tcall->sdata;
 624                 m->wsize = req->tcall->size;
 625                 m->wpos = 0;
 626                 spin_unlock(&m->lock);
 627         }
 628
 629         P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos,
 630                                                                 m->wsize);
 631         clear_bit(Wpending, &m->wsched);
 632         err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
 633         P9_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
 634         if (err == -EAGAIN) {
 635                 clear_bit(Wworksched, &m->wsched);
 636                 return;
 637         }
 638
 639         if (err < 0)
 640                 goto error;
 641         else if (err == 0) {
 642                 err = -EREMOTEIO;
 643                 goto error;
 644         }
 645
 646         m->wpos += err;
 647         if (m->wpos == m->wsize)
 648                 m->wpos = m->wsize = 0;
 649
 650         if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
 651                 if (test_and_clear_bit(Wpending, &m->wsched))
 652                         n = POLLOUT;
 653                 else
 654                         n = p9_fd_poll(m->client, NULL);
 655
 656                 if (n & POLLOUT) {
 657                         P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
 658                         queue_work(p9_mux_wq, &m->wq);
 659                 } else
 660                         clear_bit(Wworksched, &m->wsched);
 661         } else
 662                 clear_bit(Wworksched, &m->wsched);
 663
 664         return;
 665
 666 error:
 667         p9_conn_cancel(m, err);
 668         clear_bit(Wworksched, &m->wsched);
 669 }
 670
 671 static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
 672 {
 673         struct p9_poll_wait *pwait =
 674                 container_of(wait, struct p9_poll_wait, wait);
 675         struct p9_conn *m = pwait->conn;
 676         unsigned long flags;
 677         DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
 678
 679         spin_lock_irqsave(&p9_poll_lock, flags);
 680         if (list_empty(&m->poll_pending_link))
 681                 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
 682         spin_unlock_irqrestore(&p9_poll_lock, flags);
 683
 684         /* perform the default wake up operation */
 685         return default_wake_function(&dummy_wait, mode, sync, key);
 686 }
 687
 688 /**
 689  * p9_pollwait - add poll task to the wait queue
 690  * @filp: file pointer being polled
 691  * @wait_address: wait_q to block on
 692  * @p: poll state
 693  *
 694  * called by files poll operation to add v9fs-poll task to files wait queue
 695  */
 696
 697 static void
 698 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
 699 {
 700         struct p9_conn *m = container_of(p, struct p9_conn, pt);
 701         struct p9_poll_wait *pwait = NULL;
 702         int i;
 703
 704         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 705                 if (m->poll_wait[i].wait_addr == NULL) {
 706                         pwait = &m->poll_wait[i];
 707                         break;
 708                 }
 709         }
 710
 711         if (!pwait) {
 712                 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
 713                 return;
 714         }
 715
 716         if (!wait_address) {
 717                 P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
 718                 pwait->wait_addr = ERR_PTR(-EIO);
 719                 return;
 720         }
 721
 722         pwait->conn = m;
 723         pwait->wait_addr = wait_address;
 724         init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
 725         add_wait_queue(wait_address, &pwait->wait);
 726 }
 727
 728 /**
 729  * p9_conn_create - allocate and initialize the per-session mux data
 730  * @client: client instance
 731  *
 732  * Note: Creates the polling task if this is the first session.
 733  */
 734
 735 static struct p9_conn *p9_conn_create(struct p9_client *client)
 736 {
 737         int i, n;
 738         struct p9_conn *m;
 739
 740         P9_DPRINTK(P9_DEBUG_MUX, "client %p msize %d\n", client, client->msize);
 741         m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
 742         if (!m)
 743                 return ERR_PTR(-ENOMEM);
 744
 745         spin_lock_init(&m->lock);
 746         INIT_LIST_HEAD(&m->mux_list);
 747         m->client = client;
 748         m->tagpool = p9_idpool_create();
 749         if (IS_ERR(m->tagpool)) {
 750                 kfree(m);
 751                 return ERR_PTR(-ENOMEM);
 752         }
 753
 754         INIT_LIST_HEAD(&m->req_list);
 755         INIT_LIST_HEAD(&m->unsent_req_list);
 756         INIT_WORK(&m->rq, p9_read_work);
 757         INIT_WORK(&m->wq, p9_write_work);
 758         INIT_LIST_HEAD(&m->poll_pending_link);
 759         init_poll_funcptr(&m->pt, p9_pollwait);
 760
 761         n = p9_fd_poll(client, &m->pt);
 762         if (n & POLLIN) {
 763                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
 764                 set_bit(Rpending, &m->wsched);
 765         }
 766
 767         if (n & POLLOUT) {
 768                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
 769                 set_bit(Wpending, &m->wsched);
 770         }
 771
 772         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 773                 if (IS_ERR(m->poll_wait[i].wait_addr)) {
 774                         p9_mux_poll_stop(m);
 775                         kfree(m);
 776                         /* return the error code */
 777                         return (void *)m->poll_wait[i].wait_addr;
 778                 }
 779         }
 780
 781         return m;
 782 }
 783
 784 /**
 785  * p9_poll_mux - polls a mux and schedules read or write works if necessary
 786  * @m: connection to poll
 787  *
 788  */
 789
 790 static void p9_poll_mux(struct p9_conn *m)
 791 {
 792         int n;
 793
 794         if (m->err < 0)
 795                 return;
 796
 797         n = p9_fd_poll(m->client, NULL);
 798         if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
 799                 P9_DPRINTK(P9_DEBUG_MUX, "error mux %p err %d\n", m, n);
 800                 if (n >= 0)
 801                         n = -ECONNRESET;
 802                 p9_conn_cancel(m, n);
 803         }
 804
 805         if (n & POLLIN) {
 806                 set_bit(Rpending, &m->wsched);
 807                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
 808                 if (!test_and_set_bit(Rworksched, &m->wsched)) {
 809                         P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
 810                         queue_work(p9_mux_wq, &m->rq);
 811                 }
 812         }
 813
 814         if (n & POLLOUT) {
 815                 set_bit(Wpending, &m->wsched);
 816                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
 817                 if ((m->wsize || !list_empty(&m->unsent_req_list))
 818                     && !test_and_set_bit(Wworksched, &m->wsched)) {
 819                         P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
 820                         queue_work(p9_mux_wq, &m->wq);
 821                 }
 822         }
 823 }
 824
 825 /**
 826  * p9_send_request - send 9P request
 827  * The function can sleep until the request is scheduled for sending.
 828  * The function can be interrupted. Return from the function is not
 829  * a guarantee that the request is sent successfully. Can return errors
 830  * that can be retrieved by PTR_ERR macros.
 831  *
 832  * @m: mux data
 833  * @tc: request to be sent
 834  *
 835  */
 836
 837 static struct p9_req *p9_send_request(struct p9_conn *m, struct p9_fcall *tc)
 838 {
 839         int n;
 840         struct p9_req *req;
 841
 842         P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
 843                 tc, tc->id);
 844         if (m->err < 0)
 845                 return ERR_PTR(m->err);
 846
 847         req = kmalloc(sizeof(struct p9_req), GFP_KERNEL);
 848         if (!req)
 849                 return ERR_PTR(-ENOMEM);
 850
 851         if (tc->id == P9_TVERSION)
 852                 n = P9_NOTAG;
 853         else
 854                 n = p9_mux_get_tag(m);
 855
 856         if (n < 0) {
 857                 kfree(req);
 858                 return ERR_PTR(-ENOMEM);
 859         }
 860
 861         p9_set_tag(tc, n);
 862
 863 #ifdef CONFIG_NET_9P_DEBUG
 864         if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
 865                 char buf[150];
 866
 867                 p9_printfcall(buf, sizeof(buf), tc, m->client->dotu);
 868                 printk(KERN_NOTICE "<<< %p %s\n", m, buf);
 869         }
 870 #endif
 871
 872         spin_lock_init(&req->lock);
 873         req->m = m;
 874         init_waitqueue_head(&req->wqueue);
 875         req->tag = n;
 876         req->tcall = tc;
 877         req->rcall = NULL;
 878         req->err = 0;
 879         req->flush = None;
 880
 881         spin_lock(&m->lock);
 882         list_add_tail(&req->req_list, &m->unsent_req_list);
 883         spin_unlock(&m->lock);
 884
 885         if (test_and_clear_bit(Wpending, &m->wsched))
 886                 n = POLLOUT;
 887         else
 888                 n = p9_fd_poll(m->client, NULL);
 889
 890         if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
 891                 queue_work(p9_mux_wq, &m->wq);
 892
 893         return req;
 894 }
 895
 896 static int
 897 p9_mux_flush_request(struct p9_conn *m, struct p9_req *req)
 898 {
 899         struct p9_fcall *fc;
 900         struct p9_req *rreq, *rptr;
 901
 902         P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
 903
 904         /* if a response was received for a request, do nothing */
 905         spin_lock(&req->lock);
 906         if (req->rcall || req->err) {
 907                 spin_unlock(&req->lock);
 908                 P9_DPRINTK(P9_DEBUG_MUX,
 909                         "mux %p req %p response already received\n", m, req);
 910                 return 0;
 911         }
 912
 913         req->flush = Flushing;
 914         spin_unlock(&req->lock);
 915
 916         spin_lock(&m->lock);
 917         /* if the request is not sent yet, just remove it from the list */
 918         list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) {
 919                 if (rreq->tag == req->tag) {
 920                         P9_DPRINTK(P9_DEBUG_MUX,
 921                            "mux %p req %p request is not sent yet\n", m, req);
 922                         list_del(&rreq->req_list);
 923                         req->flush = Flushed;
 924                         spin_unlock(&m->lock);
 925                         p9_conn_rpc_cb(req);
 926                         return 0;
 927                 }
 928         }
 929         spin_unlock(&m->lock);
 930
 931         clear_thread_flag(TIF_SIGPENDING);
 932         fc = p9_create_tflush(req->tag);
 933         p9_send_request(m, fc);
 934         return 1;
 935 }
 936
 937 /**
 938  * p9_fd_rpc- sends 9P request and waits until a response is available.
 939  *      The function can be interrupted.
 940  * @client: client instance
 941  * @tc: request to be sent
 942  * @rc: pointer where a pointer to the response is stored
 943  *
 944  */
 945
 946 int
 947 p9_fd_rpc(struct p9_client *client, struct p9_fcall *tc, struct p9_fcall **rc)
 948 {
 949         struct p9_trans_fd *p = client->trans;
 950         struct p9_conn *m = p->conn;
 951         int err, sigpending;
 952         unsigned long flags;
 953         struct p9_req *req;
 954
 955         if (rc)
 956                 *rc = NULL;
 957
 958         sigpending = 0;
 959         if (signal_pending(current)) {
 960                 sigpending = 1;
 961                 clear_thread_flag(TIF_SIGPENDING);
 962         }
 963
 964         req = p9_send_request(m, tc);
 965         if (IS_ERR(req)) {
 966                 err = PTR_ERR(req);
 967                 P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
 968                 return err;
 969         }
 970
 971         err = wait_event_interruptible(req->wqueue, req->rcall != NULL ||
 972                                                                 req->err < 0);
 973         if (req->err < 0)
 974                 err = req->err;
 975
 976         if (err == -ERESTARTSYS && client->status == Connected
 977                                                         && m->err == 0) {
 978                 if (p9_mux_flush_request(m, req)) {
 979                         /* wait until we get response of the flush message */
 980                         do {
 981                                 clear_thread_flag(TIF_SIGPENDING);
 982                                 err = wait_event_interruptible(req->wqueue,
 983                                         req->rcall || req->err);
 984                         } while (!req->rcall && !req->err &&
 985                                         err == -ERESTARTSYS &&
 986                                         client->status == Connected && !m->err);
 987
 988                         err = -ERESTARTSYS;
 989                 }
 990                 sigpending = 1;
 991         }
 992
 993         if (sigpending) {
 994                 spin_lock_irqsave(&current->sighand->siglock, flags);
 995                 recalc_sigpending();
 996                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 997         }
 998
 999         if (rc)
1000                 *rc = req->rcall;
1001         else
1002                 kfree(req->rcall);
1003
1004         p9_mux_free_request(m, req);
1005         if (err > 0)
1006                 err = -EIO;
1007
1008         return err;
1009 }
1010
1011 /**
1012  * parse_options - parse mount options into session structure
1013  * @options: options string passed from mount
1014  * @opts: transport-specific structure to parse options into
1015  *
1016  * Returns 0 upon success, -ERRNO upon failure
1017  */
1018
1019 static int parse_opts(char *params, struct p9_fd_opts *opts)
1020 {
1021         char *p;
1022         substring_t args[MAX_OPT_ARGS];
1023         int option;
1024         char *options;
1025         int ret;
1026
1027         opts->port = P9_PORT;
1028         opts->rfd = ~0;
1029         opts->wfd = ~0;
1030
1031         if (!params)
1032                 return 0;
1033
1034         options = kstrdup(params, GFP_KERNEL);
1035         if (!options) {
1036                 P9_DPRINTK(P9_DEBUG_ERROR,
1037                                 "failed to allocate copy of option string\n");
1038                 return -ENOMEM;
1039         }
1040
1041         while ((p = strsep(&options, ",")) != NULL) {
1042                 int token;
1043                 int r;
1044                 if (!*p)
1045                         continue;
1046                 token = match_token(p, tokens, args);
1047                 r = match_int(&args[0], &option);
1048                 if (r < 0) {
1049                         P9_DPRINTK(P9_DEBUG_ERROR,
1050                          "integer field, but no integer?\n");
1051                         ret = r;
1052                         continue;
1053                 }
1054                 switch (token) {
1055                 case Opt_port:
1056                         opts->port = option;
1057                         break;
1058                 case Opt_rfdno:
1059                         opts->rfd = option;
1060                         break;
1061                 case Opt_wfdno:
1062                         opts->wfd = option;
1063                         break;
1064                 default:
1065                         continue;
1066                 }
1067         }
1068         kfree(options);
1069         return 0;
1070 }
1071
1072 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
1073 {
1074         struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
1075                                            GFP_KERNEL);
1076         if (!ts)
1077                 return -ENOMEM;
1078
1079         ts->rd = fget(rfd);
1080         ts->wr = fget(wfd);
1081         if (!ts->rd || !ts->wr) {
1082                 if (ts->rd)
1083                         fput(ts->rd);
1084                 if (ts->wr)
1085                         fput(ts->wr);
1086                 kfree(ts);
1087                 return -EIO;
1088         }
1089
1090         client->trans = ts;
1091         client->status = Connected;
1092
1093         return 0;
1094 }
1095
1096 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
1097 {
1098         int fd, ret;
1099
1100         csocket->sk->sk_allocation = GFP_NOIO;
1101         fd = sock_map_fd(csocket, 0);
1102         if (fd < 0) {
1103                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
1104                 return fd;
1105         }
1106
1107         ret = p9_fd_open(client, fd, fd);
1108         if (ret < 0) {
1109                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
1110                 sockfd_put(csocket);
1111                 return ret;
1112         }
1113
1114         ((struct p9_trans_fd *)client->trans)->rd->f_flags |= O_NONBLOCK;
1115
1116         return 0;
1117 }
1118
1119 /**
1120  * p9_mux_destroy - cancels all pending requests and frees mux resources
1121  * @m: mux to destroy
1122  *
1123  */
1124
1125 static void p9_conn_destroy(struct p9_conn *m)
1126 {
1127         P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
1128                 m->mux_list.prev, m->mux_list.next);
1129
1130         p9_mux_poll_stop(m);
1131         cancel_work_sync(&m->rq);
1132         cancel_work_sync(&m->wq);
1133
1134         p9_conn_cancel(m, -ECONNRESET);
1135
1136         m->client = NULL;
1137         p9_idpool_destroy(m->tagpool);
1138         kfree(m);
1139 }
1140
1141 /**
1142  * p9_fd_close - shutdown file descriptor transport
1143  * @client: client instance
1144  *
1145  */
1146
1147 static void p9_fd_close(struct p9_client *client)
1148 {
1149         struct p9_trans_fd *ts;
1150
1151         if (!client)
1152                 return;
1153
1154         ts = client->trans;
1155         if (!ts)
1156                 return;
1157
1158         client->status = Disconnected;
1159
1160         p9_conn_destroy(ts->conn);
1161
1162         if (ts->rd)
1163                 fput(ts->rd);
1164         if (ts->wr)
1165                 fput(ts->wr);
1166
1167         kfree(ts);
1168 }
1169
1170 /*
1171  * stolen from NFS - maybe should be made a generic function?
1172  */
1173 static inline int valid_ipaddr4(const char *buf)
1174 {
1175         int rc, count, in[4];
1176
1177         rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
1178         if (rc != 4)
1179                 return -EINVAL;
1180         for (count = 0; count < 4; count++) {
1181                 if (in[count] > 255)
1182                         return -EINVAL;
1183         }
1184         return 0;
1185 }
1186
1187 static int
1188 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
1189 {
1190         int err;
1191         struct socket *csocket;
1192         struct sockaddr_in sin_server;
1193         struct p9_fd_opts opts;
1194         struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
1195
1196         err = parse_opts(args, &opts);
1197         if (err < 0)
1198                 return err;
1199
1200         if (valid_ipaddr4(addr) < 0)
1201                 return -EINVAL;
1202
1203         csocket = NULL;
1204
1205         sin_server.sin_family = AF_INET;
1206         sin_server.sin_addr.s_addr = in_aton(addr);
1207         sin_server.sin_port = htons(opts.port);
1208         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
1209
1210         if (!csocket) {
1211                 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
1212                 err = -EIO;
1213                 goto error;
1214         }
1215
1216         err = csocket->ops->connect(csocket,
1217                                     (struct sockaddr *)&sin_server,
1218                                     sizeof(struct sockaddr_in), 0);
1219         if (err < 0) {
1220                 P9_EPRINTK(KERN_ERR,
1221                         "p9_trans_tcp: problem connecting socket to %s\n",
1222                         addr);
1223                 goto error;
1224         }
1225
1226         err = p9_socket_open(client, csocket);
1227         if (err < 0)
1228                 goto error;
1229
1230         p = (struct p9_trans_fd *) client->trans;
1231         p->conn = p9_conn_create(client);
1232         if (IS_ERR(p->conn)) {
1233                 err = PTR_ERR(p->conn);
1234                 p->conn = NULL;
1235                 goto error;
1236         }
1237
1238         return 0;
1239
1240 error:
1241         if (csocket)
1242                 sock_release(csocket);
1243
1244         kfree(p);
1245
1246         return err;
1247 }
1248
1249 static int
1250 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
1251 {
1252         int err;
1253         struct socket *csocket;
1254         struct sockaddr_un sun_server;
1255         struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
1256
1257         csocket = NULL;
1258
1259         if (strlen(addr) > UNIX_PATH_MAX) {
1260                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
1261                         addr);
1262                 err = -ENAMETOOLONG;
1263                 goto error;
1264         }
1265
1266         sun_server.sun_family = PF_UNIX;
1267         strcpy(sun_server.sun_path, addr);
1268         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
1269         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1270                         sizeof(struct sockaddr_un) - 1, 0);
1271         if (err < 0) {
1272                 P9_EPRINTK(KERN_ERR,
1273                         "p9_trans_unix: problem connecting socket: %s: %d\n",
1274                         addr, err);
1275                 goto error;
1276         }
1277
1278         err = p9_socket_open(client, csocket);
1279         if (err < 0)
1280                 goto error;
1281
1282         p = (struct p9_trans_fd *) client->trans;
1283         p->conn = p9_conn_create(client);
1284         if (IS_ERR(p->conn)) {
1285                 err = PTR_ERR(p->conn);
1286                 p->conn = NULL;
1287                 goto error;
1288         }
1289
1290         return 0;
1291
1292 error:
1293         if (csocket)
1294                 sock_release(csocket);
1295
1296         kfree(p);
1297         return err;
1298 }
1299
1300 static int
1301 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1302 {
1303         int err;
1304         struct p9_fd_opts opts;
1305         struct p9_trans_fd *p = NULL; /* this get allocated in p9_fd_open */
1306
1307         parse_opts(args, &opts);
1308
1309         if (opts.rfd == ~0 || opts.wfd == ~0) {
1310                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
1311                 return -ENOPROTOOPT;
1312         }
1313
1314         err = p9_fd_open(client, opts.rfd, opts.wfd);
1315         if (err < 0)
1316                 goto error;
1317
1318         p = (struct p9_trans_fd *) client->trans;
1319         p->conn = p9_conn_create(client);
1320         if (IS_ERR(p->conn)) {
1321                 err = PTR_ERR(p->conn);
1322                 p->conn = NULL;
1323                 goto error;
1324         }
1325
1326         return 0;
1327
1328 error:
1329         kfree(p);
1330         return err;
1331 }
1332
1333 static struct p9_trans_module p9_tcp_trans = {
1334         .name = "tcp",
1335         .maxsize = MAX_SOCK_BUF,
1336         .def = 1,
1337         .create = p9_fd_create_tcp,
1338         .close = p9_fd_close,
1339         .rpc = p9_fd_rpc,
1340         .owner = THIS_MODULE,
1341 };
1342
1343 static struct p9_trans_module p9_unix_trans = {
1344         .name = "unix",
1345         .maxsize = MAX_SOCK_BUF,
1346         .def = 0,
1347         .create = p9_fd_create_unix,
1348         .close = p9_fd_close,
1349         .rpc = p9_fd_rpc,
1350         .owner = THIS_MODULE,
1351 };
1352
1353 static struct p9_trans_module p9_fd_trans = {
1354         .name = "fd",
1355         .maxsize = MAX_SOCK_BUF,
1356         .def = 0,
1357         .create = p9_fd_create,
1358         .close = p9_fd_close,
1359         .rpc = p9_fd_rpc,
1360         .owner = THIS_MODULE,
1361 };
1362
1363 /**
1364  * p9_poll_proc - poll worker thread
1365  * @a: thread state and arguments
1366  *
1367  * polls all v9fs transports for new events and queues the appropriate
1368  * work to the work queue
1369  *
1370  */
1371
1372 static int p9_poll_proc(void *a)
1373 {
1374         unsigned long flags;
1375
1376         P9_DPRINTK(P9_DEBUG_MUX, "start %p\n", current);
1377  repeat:
1378         spin_lock_irqsave(&p9_poll_lock, flags);
1379         while (!list_empty(&p9_poll_pending_list)) {
1380                 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1381                                                         struct p9_conn,
1382                                                         poll_pending_link);
1383                 list_del_init(&conn->poll_pending_link);
1384                 spin_unlock_irqrestore(&p9_poll_lock, flags);
1385
1386                 p9_poll_mux(conn);
1387
1388                 spin_lock_irqsave(&p9_poll_lock, flags);
1389         }
1390         spin_unlock_irqrestore(&p9_poll_lock, flags);
1391
1392         set_current_state(TASK_INTERRUPTIBLE);
1393         if (list_empty(&p9_poll_pending_list)) {
1394                 P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
1395                 schedule();
1396         }
1397         __set_current_state(TASK_RUNNING);
1398
1399         if (!kthread_should_stop())
1400                 goto repeat;
1401
1402         P9_DPRINTK(P9_DEBUG_MUX, "finish\n");
1403         return 0;
1404 }
1405
1406 int p9_trans_fd_init(void)
1407 {
1408         p9_mux_wq = create_workqueue("v9fs");
1409         if (!p9_mux_wq) {
1410                 printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
1411                 return -ENOMEM;
1412         }
1413
1414         p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll");
1415         if (IS_ERR(p9_poll_task)) {
1416                 destroy_workqueue(p9_mux_wq);
1417                 printk(KERN_WARNING "v9fs: mux: creating poll task failed\n");
1418                 return PTR_ERR(p9_poll_task);
1419         }
1420
1421         v9fs_register_trans(&p9_tcp_trans);
1422         v9fs_register_trans(&p9_unix_trans);
1423         v9fs_register_trans(&p9_fd_trans);
1424
1425         return 0;
1426 }
1427
1428 void p9_trans_fd_exit(void)
1429 {
1430         kthread_stop(p9_poll_task);
1431         v9fs_unregister_trans(&p9_tcp_trans);
1432         v9fs_unregister_trans(&p9_unix_trans);
1433         v9fs_unregister_trans(&p9_fd_trans);
1434
1435         destroy_workqueue(p9_mux_wq);
1436 }