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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/transport.h>
  43
  44 #define P9_PORT 564
  45 #define MAX_SOCK_BUF (64*1024)
  46 #define ERREQFLUSH      1
  47 #define SCHED_TIMEOUT   10
  48 #define MAXPOLLWADDR    2
  49
  50 struct p9_fd_opts {
  51         int rfd;
  52         int wfd;
  53         u16 port;
  54 };
  55
  56 struct p9_trans_fd {
  57         struct file *rd;
  58         struct file *wr;
  59         struct p9_conn *conn;
  60 };
  61
  62 /*
  63   * Option Parsing (code inspired by NFS code)
  64   *  - a little lazy - parse all fd-transport options
  65   */
  66
  67 enum {
  68         /* Options that take integer arguments */
  69         Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
  70 };
  71
  72 static match_table_t tokens = {
  73         {Opt_port, "port=%u"},
  74         {Opt_rfdno, "rfdno=%u"},
  75         {Opt_wfdno, "wfdno=%u"},
  76         {Opt_err, NULL},
  77 };
  78
  79 enum {
  80         Rworksched = 1,         /* read work scheduled or running */
  81         Rpending = 2,           /* can read */
  82         Wworksched = 4,         /* write work scheduled or running */
  83         Wpending = 8,           /* can write */
  84 };
  85
  86 enum {
  87         None,
  88         Flushing,
  89         Flushed,
  90 };
  91
  92 struct p9_req;
  93
  94 typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a);
  95 struct p9_req {
  96         spinlock_t lock; /* protect request structure */
  97         int tag;
  98         struct p9_fcall *tcall;
  99         struct p9_fcall *rcall;
 100         int err;
 101         p9_conn_req_callback cb;
 102         void *cba;
 103         int flush;
 104         struct list_head req_list;
 105 };
 106
 107 struct p9_mux_poll_task;
 108
 109 struct p9_conn {
 110         spinlock_t lock; /* protect lock structure */
 111         struct list_head mux_list;
 112         struct p9_mux_poll_task *poll_task;
 113         int msize;
 114         unsigned char extended;
 115         struct p9_trans *trans;
 116         struct p9_idpool *tagpool;
 117         int err;
 118         wait_queue_head_t equeue;
 119         struct list_head req_list;
 120         struct list_head unsent_req_list;
 121         struct p9_fcall *rcall;
 122         int rpos;
 123         char *rbuf;
 124         int wpos;
 125         int wsize;
 126         char *wbuf;
 127         wait_queue_t poll_wait[MAXPOLLWADDR];
 128         wait_queue_head_t *poll_waddr[MAXPOLLWADDR];
 129         poll_table pt;
 130         struct work_struct rq;
 131         struct work_struct wq;
 132         unsigned long wsched;
 133 };
 134
 135 struct p9_mux_poll_task {
 136         struct task_struct *task;
 137         struct list_head mux_list;
 138         int muxnum;
 139 };
 140
 141 struct p9_mux_rpc {
 142         struct p9_conn *m;
 143         int err;
 144         struct p9_fcall *tcall;
 145         struct p9_fcall *rcall;
 146         wait_queue_head_t wqueue;
 147 };
 148
 149 static int p9_poll_proc(void *);
 150 static void p9_read_work(struct work_struct *work);
 151 static void p9_write_work(struct work_struct *work);
 152 static void p9_pollwait(struct file *filp, wait_queue_head_t *wait_address,
 153                                                                 poll_table *p);
 154 static int p9_fd_write(struct p9_trans *trans, void *v, int len);
 155 static int p9_fd_read(struct p9_trans *trans, void *v, int len);
 156
 157 static DEFINE_MUTEX(p9_mux_task_lock);
 158 static struct workqueue_struct *p9_mux_wq;
 159
 160 static int p9_mux_num;
 161 static int p9_mux_poll_task_num;
 162 static struct p9_mux_poll_task p9_mux_poll_tasks[100];
 163
 164 static void p9_conn_destroy(struct p9_conn *);
 165 static unsigned int p9_fd_poll(struct p9_trans *trans,
 166                                                 struct poll_table_struct *pt);
 167
 168 #ifdef P9_NONBLOCK
 169 static int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
 170         p9_conn_req_callback cb, void *a);
 171 #endif /* P9_NONBLOCK */
 172
 173 static void p9_conn_cancel(struct p9_conn *m, int err);
 174
 175 static int p9_mux_global_init(void)
 176 {
 177         int i;
 178
 179         for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++)
 180                 p9_mux_poll_tasks[i].task = NULL;
 181
 182         p9_mux_wq = create_workqueue("v9fs");
 183         if (!p9_mux_wq) {
 184                 printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
 185                 return -ENOMEM;
 186         }
 187
 188         return 0;
 189 }
 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 /**
 209  * p9_mux_calc_poll_procs - calculates the number of polling procs
 210  * based on the number of mounted v9fs filesystems.
 211  *
 212  * The current implementation returns sqrt of the number of mounts.
 213  */
 214 static int p9_mux_calc_poll_procs(int muxnum)
 215 {
 216         int n;
 217
 218         if (p9_mux_poll_task_num)
 219                 n = muxnum / p9_mux_poll_task_num +
 220                     (muxnum % p9_mux_poll_task_num ? 1 : 0);
 221         else
 222                 n = 1;
 223
 224         if (n > ARRAY_SIZE(p9_mux_poll_tasks))
 225                 n = ARRAY_SIZE(p9_mux_poll_tasks);
 226
 227         return n;
 228 }
 229
 230 static int p9_mux_poll_start(struct p9_conn *m)
 231 {
 232         int i, n;
 233         struct p9_mux_poll_task *vpt, *vptlast;
 234         struct task_struct *pproc;
 235
 236         P9_DPRINTK(P9_DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, p9_mux_num,
 237                 p9_mux_poll_task_num);
 238         mutex_lock(&p9_mux_task_lock);
 239
 240         n = p9_mux_calc_poll_procs(p9_mux_num + 1);
 241         if (n > p9_mux_poll_task_num) {
 242                 for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
 243                         if (p9_mux_poll_tasks[i].task == NULL) {
 244                                 vpt = &p9_mux_poll_tasks[i];
 245                                 P9_DPRINTK(P9_DEBUG_MUX, "create proc %p\n",
 246                                                                         vpt);
 247                                 pproc = kthread_create(p9_poll_proc, vpt,
 248                                                                 "v9fs-poll");
 249
 250                                 if (!IS_ERR(pproc)) {
 251                                         vpt->task = pproc;
 252                                         INIT_LIST_HEAD(&vpt->mux_list);
 253                                         vpt->muxnum = 0;
 254                                         p9_mux_poll_task_num++;
 255                                         wake_up_process(vpt->task);
 256                                 }
 257                                 break;
 258                         }
 259                 }
 260
 261                 if (i >= ARRAY_SIZE(p9_mux_poll_tasks))
 262                         P9_DPRINTK(P9_DEBUG_ERROR,
 263                                         "warning: no free poll slots\n");
 264         }
 265
 266         n = (p9_mux_num + 1) / p9_mux_poll_task_num +
 267             ((p9_mux_num + 1) % p9_mux_poll_task_num ? 1 : 0);
 268
 269         vptlast = NULL;
 270         for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
 271                 vpt = &p9_mux_poll_tasks[i];
 272                 if (vpt->task != NULL) {
 273                         vptlast = vpt;
 274                         if (vpt->muxnum < n) {
 275                                 P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
 276                                 list_add(&m->mux_list, &vpt->mux_list);
 277                                 vpt->muxnum++;
 278                                 m->poll_task = vpt;
 279                                 memset(&m->poll_waddr, 0,
 280                                                         sizeof(m->poll_waddr));
 281                                 init_poll_funcptr(&m->pt, p9_pollwait);
 282                                 break;
 283                         }
 284                 }
 285         }
 286
 287         if (i >= ARRAY_SIZE(p9_mux_poll_tasks)) {
 288                 if (vptlast == NULL) {
 289                         mutex_unlock(&p9_mux_task_lock);
 290                         return -ENOMEM;
 291                 }
 292
 293                 P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
 294                 list_add(&m->mux_list, &vptlast->mux_list);
 295                 vptlast->muxnum++;
 296                 m->poll_task = vptlast;
 297                 memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
 298                 init_poll_funcptr(&m->pt, p9_pollwait);
 299         }
 300
 301         p9_mux_num++;
 302         mutex_unlock(&p9_mux_task_lock);
 303
 304         return 0;
 305 }
 306
 307 static void p9_mux_poll_stop(struct p9_conn *m)
 308 {
 309         int i;
 310         struct p9_mux_poll_task *vpt;
 311
 312         mutex_lock(&p9_mux_task_lock);
 313         vpt = m->poll_task;
 314         list_del(&m->mux_list);
 315         for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
 316                 if (m->poll_waddr[i] != NULL) {
 317                         remove_wait_queue(m->poll_waddr[i], &m->poll_wait[i]);
 318                         m->poll_waddr[i] = NULL;
 319                 }
 320         }
 321         vpt->muxnum--;
 322         if (!vpt->muxnum) {
 323                 P9_DPRINTK(P9_DEBUG_MUX, "destroy proc %p\n", vpt);
 324                 kthread_stop(vpt->task);
 325                 vpt->task = NULL;
 326                 p9_mux_poll_task_num--;
 327         }
 328         p9_mux_num--;
 329         mutex_unlock(&p9_mux_task_lock);
 330 }
 331
 332 /**
 333  * p9_conn_create - allocate and initialize the per-session mux data
 334  * Creates the polling task if this is the first session.
 335  *
 336  * @trans - transport structure
 337  * @msize - maximum message size
 338  * @extended - extended flag
 339  */
 340 static struct p9_conn *p9_conn_create(struct p9_trans *trans)
 341 {
 342         int i, n;
 343         struct p9_conn *m, *mtmp;
 344
 345         P9_DPRINTK(P9_DEBUG_MUX, "transport %p msize %d\n", trans,
 346                                                                 trans->msize);
 347         m = kmalloc(sizeof(struct p9_conn), GFP_KERNEL);
 348         if (!m)
 349                 return ERR_PTR(-ENOMEM);
 350
 351         spin_lock_init(&m->lock);
 352         INIT_LIST_HEAD(&m->mux_list);
 353         m->msize = trans->msize;
 354         m->extended = trans->extended;
 355         m->trans = trans;
 356         m->tagpool = p9_idpool_create();
 357         if (IS_ERR(m->tagpool)) {
 358                 mtmp = ERR_PTR(-ENOMEM);
 359                 kfree(m);
 360                 return mtmp;
 361         }
 362
 363         m->err = 0;
 364         init_waitqueue_head(&m->equeue);
 365         INIT_LIST_HEAD(&m->req_list);
 366         INIT_LIST_HEAD(&m->unsent_req_list);
 367         m->rcall = NULL;
 368         m->rpos = 0;
 369         m->rbuf = NULL;
 370         m->wpos = m->wsize = 0;
 371         m->wbuf = NULL;
 372         INIT_WORK(&m->rq, p9_read_work);
 373         INIT_WORK(&m->wq, p9_write_work);
 374         m->wsched = 0;
 375         memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
 376         m->poll_task = NULL;
 377         n = p9_mux_poll_start(m);
 378         if (n) {
 379                 kfree(m);
 380                 return ERR_PTR(n);
 381         }
 382
 383         n = p9_fd_poll(trans, &m->pt);
 384         if (n & POLLIN) {
 385                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
 386                 set_bit(Rpending, &m->wsched);
 387         }
 388
 389         if (n & POLLOUT) {
 390                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
 391                 set_bit(Wpending, &m->wsched);
 392         }
 393
 394         for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
 395                 if (IS_ERR(m->poll_waddr[i])) {
 396                         p9_mux_poll_stop(m);
 397                         mtmp = (void *)m->poll_waddr;   /* the error code */
 398                         kfree(m);
 399                         m = mtmp;
 400                         break;
 401                 }
 402         }
 403
 404         return m;
 405 }
 406
 407 /**
 408  * p9_mux_destroy - cancels all pending requests and frees mux resources
 409  */
 410 static void p9_conn_destroy(struct p9_conn *m)
 411 {
 412         P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
 413                 m->mux_list.prev, m->mux_list.next);
 414         p9_conn_cancel(m, -ECONNRESET);
 415
 416         if (!list_empty(&m->req_list)) {
 417                 /* wait until all processes waiting on this session exit */
 418                 P9_DPRINTK(P9_DEBUG_MUX,
 419                         "mux %p waiting for empty request queue\n", m);
 420                 wait_event_timeout(m->equeue, (list_empty(&m->req_list)), 5000);
 421                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p request queue empty: %d\n", m,
 422                         list_empty(&m->req_list));
 423         }
 424
 425         p9_mux_poll_stop(m);
 426         m->trans = NULL;
 427         p9_idpool_destroy(m->tagpool);
 428         kfree(m);
 429 }
 430
 431 /**
 432  * p9_pollwait - called by files poll operation to add v9fs-poll task
 433  *      to files wait queue
 434  */
 435 static void
 436 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
 437 {
 438         int i;
 439         struct p9_conn *m;
 440
 441         m = container_of(p, struct p9_conn, pt);
 442         for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++)
 443                 if (m->poll_waddr[i] == NULL)
 444                         break;
 445
 446         if (i >= ARRAY_SIZE(m->poll_waddr)) {
 447                 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
 448                 return;
 449         }
 450
 451         m->poll_waddr[i] = wait_address;
 452
 453         if (!wait_address) {
 454                 P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
 455                 m->poll_waddr[i] = ERR_PTR(-EIO);
 456                 return;
 457         }
 458
 459         init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task);
 460         add_wait_queue(wait_address, &m->poll_wait[i]);
 461 }
 462
 463 /**
 464  * p9_poll_mux - polls a mux and schedules read or write works if necessary
 465  */
 466 static void p9_poll_mux(struct p9_conn *m)
 467 {
 468         int n;
 469
 470         if (m->err < 0)
 471                 return;
 472
 473         n = p9_fd_poll(m->trans, NULL);
 474         if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
 475                 P9_DPRINTK(P9_DEBUG_MUX, "error mux %p err %d\n", m, n);
 476                 if (n >= 0)
 477                         n = -ECONNRESET;
 478                 p9_conn_cancel(m, n);
 479         }
 480
 481         if (n & POLLIN) {
 482                 set_bit(Rpending, &m->wsched);
 483                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
 484                 if (!test_and_set_bit(Rworksched, &m->wsched)) {
 485                         P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
 486                         queue_work(p9_mux_wq, &m->rq);
 487                 }
 488         }
 489
 490         if (n & POLLOUT) {
 491                 set_bit(Wpending, &m->wsched);
 492                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
 493                 if ((m->wsize || !list_empty(&m->unsent_req_list))
 494                     && !test_and_set_bit(Wworksched, &m->wsched)) {
 495                         P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
 496                         queue_work(p9_mux_wq, &m->wq);
 497                 }
 498         }
 499 }
 500
 501 /**
 502  * p9_poll_proc - polls all v9fs transports for new events and queues
 503  *      the appropriate work to the work queue
 504  */
 505 static int p9_poll_proc(void *a)
 506 {
 507         struct p9_conn *m, *mtmp;
 508         struct p9_mux_poll_task *vpt;
 509
 510         vpt = a;
 511         P9_DPRINTK(P9_DEBUG_MUX, "start %p %p\n", current, vpt);
 512         while (!kthread_should_stop()) {
 513                 set_current_state(TASK_INTERRUPTIBLE);
 514
 515                 list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
 516                         p9_poll_mux(m);
 517                 }
 518
 519                 P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
 520                 schedule_timeout(SCHED_TIMEOUT * HZ);
 521         }
 522
 523         __set_current_state(TASK_RUNNING);
 524         P9_DPRINTK(P9_DEBUG_MUX, "finish\n");
 525         return 0;
 526 }
 527
 528 /**
 529  * p9_write_work - called when a transport can send some data
 530  */
 531 static void p9_write_work(struct work_struct *work)
 532 {
 533         int n, err;
 534         struct p9_conn *m;
 535         struct p9_req *req;
 536
 537         m = container_of(work, struct p9_conn, wq);
 538
 539         if (m->err < 0) {
 540                 clear_bit(Wworksched, &m->wsched);
 541                 return;
 542         }
 543
 544         if (!m->wsize) {
 545                 if (list_empty(&m->unsent_req_list)) {
 546                         clear_bit(Wworksched, &m->wsched);
 547                         return;
 548                 }
 549
 550                 spin_lock(&m->lock);
 551 again:
 552                 req = list_entry(m->unsent_req_list.next, struct p9_req,
 553                                req_list);
 554                 list_move_tail(&req->req_list, &m->req_list);
 555                 if (req->err == ERREQFLUSH)
 556                         goto again;
 557
 558                 m->wbuf = req->tcall->sdata;
 559                 m->wsize = req->tcall->size;
 560                 m->wpos = 0;
 561                 spin_unlock(&m->lock);
 562         }
 563
 564         P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos,
 565                                                                 m->wsize);
 566         clear_bit(Wpending, &m->wsched);
 567         err = p9_fd_write(m->trans, m->wbuf + m->wpos, m->wsize - m->wpos);
 568         P9_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
 569         if (err == -EAGAIN) {
 570                 clear_bit(Wworksched, &m->wsched);
 571                 return;
 572         }
 573
 574         if (err < 0)
 575                 goto error;
 576         else if (err == 0) {
 577                 err = -EREMOTEIO;
 578                 goto error;
 579         }
 580
 581         m->wpos += err;
 582         if (m->wpos == m->wsize)
 583                 m->wpos = m->wsize = 0;
 584
 585         if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
 586                 if (test_and_clear_bit(Wpending, &m->wsched))
 587                         n = POLLOUT;
 588                 else
 589                         n = p9_fd_poll(m->trans, NULL);
 590
 591                 if (n & POLLOUT) {
 592                         P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
 593                         queue_work(p9_mux_wq, &m->wq);
 594                 } else
 595                         clear_bit(Wworksched, &m->wsched);
 596         } else
 597                 clear_bit(Wworksched, &m->wsched);
 598
 599         return;
 600
 601 error:
 602         p9_conn_cancel(m, err);
 603         clear_bit(Wworksched, &m->wsched);
 604 }
 605
 606 static void process_request(struct p9_conn *m, struct p9_req *req)
 607 {
 608         int ecode;
 609         struct p9_str *ename;
 610
 611         if (!req->err && req->rcall->id == P9_RERROR) {
 612                 ecode = req->rcall->params.rerror.errno;
 613                 ename = &req->rcall->params.rerror.error;
 614
 615                 P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
 616                                                                 ename->str);
 617
 618                 if (m->extended)
 619                         req->err = -ecode;
 620
 621                 if (!req->err) {
 622                         req->err = p9_errstr2errno(ename->str, ename->len);
 623
 624                         /* string match failed */
 625                         if (!req->err) {
 626                                 PRINT_FCALL_ERROR("unknown error", req->rcall);
 627                                 req->err = -ESERVERFAULT;
 628                         }
 629                 }
 630         } else if (req->tcall && req->rcall->id != req->tcall->id + 1) {
 631                 P9_DPRINTK(P9_DEBUG_ERROR,
 632                                 "fcall mismatch: expected %d, got %d\n",
 633                                 req->tcall->id + 1, req->rcall->id);
 634                 if (!req->err)
 635                         req->err = -EIO;
 636         }
 637 }
 638
 639 /**
 640  * p9_read_work - called when there is some data to be read from a transport
 641  */
 642 static void p9_read_work(struct work_struct *work)
 643 {
 644         int n, err;
 645         struct p9_conn *m;
 646         struct p9_req *req, *rptr, *rreq;
 647         struct p9_fcall *rcall;
 648         char *rbuf;
 649
 650         m = container_of(work, struct p9_conn, rq);
 651
 652         if (m->err < 0)
 653                 return;
 654
 655         rcall = NULL;
 656         P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
 657
 658         if (!m->rcall) {
 659                 m->rcall =
 660                     kmalloc(sizeof(struct p9_fcall) + m->msize, GFP_KERNEL);
 661                 if (!m->rcall) {
 662                         err = -ENOMEM;
 663                         goto error;
 664                 }
 665
 666                 m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
 667                 m->rpos = 0;
 668         }
 669
 670         clear_bit(Rpending, &m->wsched);
 671         err = p9_fd_read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos);
 672         P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err);
 673         if (err == -EAGAIN) {
 674                 clear_bit(Rworksched, &m->wsched);
 675                 return;
 676         }
 677
 678         if (err <= 0)
 679                 goto error;
 680
 681         m->rpos += err;
 682         while (m->rpos > 4) {
 683                 n = le32_to_cpu(*(__le32 *) m->rbuf);
 684                 if (n >= m->msize) {
 685                         P9_DPRINTK(P9_DEBUG_ERROR,
 686                                 "requested packet size too big: %d\n", n);
 687                         err = -EIO;
 688                         goto error;
 689                 }
 690
 691                 if (m->rpos < n)
 692                         break;
 693
 694                 err =
 695                     p9_deserialize_fcall(m->rbuf, n, m->rcall, m->extended);
 696                 if (err < 0)
 697                         goto error;
 698
 699 #ifdef CONFIG_NET_9P_DEBUG
 700                 if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
 701                         char buf[150];
 702
 703                         p9_printfcall(buf, sizeof(buf), m->rcall,
 704                                 m->extended);
 705                         printk(KERN_NOTICE ">>> %p %s\n", m, buf);
 706                 }
 707 #endif
 708
 709                 rcall = m->rcall;
 710                 rbuf = m->rbuf;
 711                 if (m->rpos > n) {
 712                         m->rcall = kmalloc(sizeof(struct p9_fcall) + m->msize,
 713                                            GFP_KERNEL);
 714                         if (!m->rcall) {
 715                                 err = -ENOMEM;
 716                                 goto error;
 717                         }
 718
 719                         m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
 720                         memmove(m->rbuf, rbuf + n, m->rpos - n);
 721                         m->rpos -= n;
 722                 } else {
 723                         m->rcall = NULL;
 724                         m->rbuf = NULL;
 725                         m->rpos = 0;
 726                 }
 727
 728                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m,
 729                                                         rcall->id, rcall->tag);
 730
 731                 req = NULL;
 732                 spin_lock(&m->lock);
 733                 list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
 734                         if (rreq->tag == rcall->tag) {
 735                                 req = rreq;
 736                                 if (req->flush != Flushing)
 737                                         list_del(&req->req_list);
 738                                 break;
 739                         }
 740                 }
 741                 spin_unlock(&m->lock);
 742
 743                 if (req) {
 744                         req->rcall = rcall;
 745                         process_request(m, req);
 746
 747                         if (req->flush != Flushing) {
 748                                 if (req->cb)
 749                                         (*req->cb) (req, req->cba);
 750                                 else
 751                                         kfree(req->rcall);
 752
 753                                 wake_up(&m->equeue);
 754                         }
 755                 } else {
 756                         if (err >= 0 && rcall->id != P9_RFLUSH)
 757                                 P9_DPRINTK(P9_DEBUG_ERROR,
 758                                   "unexpected response mux %p id %d tag %d\n",
 759                                   m, rcall->id, rcall->tag);
 760                         kfree(rcall);
 761                 }
 762         }
 763
 764         if (!list_empty(&m->req_list)) {
 765                 if (test_and_clear_bit(Rpending, &m->wsched))
 766                         n = POLLIN;
 767                 else
 768                         n = p9_fd_poll(m->trans, NULL);
 769
 770                 if (n & POLLIN) {
 771                         P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
 772                         queue_work(p9_mux_wq, &m->rq);
 773                 } else
 774                         clear_bit(Rworksched, &m->wsched);
 775         } else
 776                 clear_bit(Rworksched, &m->wsched);
 777
 778         return;
 779
 780 error:
 781         p9_conn_cancel(m, err);
 782         clear_bit(Rworksched, &m->wsched);
 783 }
 784
 785 /**
 786  * p9_send_request - send 9P request
 787  * The function can sleep until the request is scheduled for sending.
 788  * The function can be interrupted. Return from the function is not
 789  * a guarantee that the request is sent successfully. Can return errors
 790  * that can be retrieved by PTR_ERR macros.
 791  *
 792  * @m: mux data
 793  * @tc: request to be sent
 794  * @cb: callback function to call when response is received
 795  * @cba: parameter to pass to the callback function
 796  */
 797 static struct p9_req *p9_send_request(struct p9_conn *m,
 798                                           struct p9_fcall *tc,
 799                                           p9_conn_req_callback cb, void *cba)
 800 {
 801         int n;
 802         struct p9_req *req;
 803
 804         P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
 805                 tc, tc->id);
 806         if (m->err < 0)
 807                 return ERR_PTR(m->err);
 808
 809         req = kmalloc(sizeof(struct p9_req), GFP_KERNEL);
 810         if (!req)
 811                 return ERR_PTR(-ENOMEM);
 812
 813         if (tc->id == P9_TVERSION)
 814                 n = P9_NOTAG;
 815         else
 816                 n = p9_mux_get_tag(m);
 817
 818         if (n < 0)
 819                 return ERR_PTR(-ENOMEM);
 820
 821         p9_set_tag(tc, n);
 822
 823 #ifdef CONFIG_NET_9P_DEBUG
 824         if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
 825                 char buf[150];
 826
 827                 p9_printfcall(buf, sizeof(buf), tc, m->extended);
 828                 printk(KERN_NOTICE "<<< %p %s\n", m, buf);
 829         }
 830 #endif
 831
 832         spin_lock_init(&req->lock);
 833         req->tag = n;
 834         req->tcall = tc;
 835         req->rcall = NULL;
 836         req->err = 0;
 837         req->cb = cb;
 838         req->cba = cba;
 839         req->flush = None;
 840
 841         spin_lock(&m->lock);
 842         list_add_tail(&req->req_list, &m->unsent_req_list);
 843         spin_unlock(&m->lock);
 844
 845         if (test_and_clear_bit(Wpending, &m->wsched))
 846                 n = POLLOUT;
 847         else
 848                 n = p9_fd_poll(m->trans, NULL);
 849
 850         if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
 851                 queue_work(p9_mux_wq, &m->wq);
 852
 853         return req;
 854 }
 855
 856 static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req)
 857 {
 858         p9_mux_put_tag(m, req->tag);
 859         kfree(req);
 860 }
 861
 862 static void p9_mux_flush_cb(struct p9_req *freq, void *a)
 863 {
 864         p9_conn_req_callback cb;
 865         int tag;
 866         struct p9_conn *m;
 867         struct p9_req *req, *rreq, *rptr;
 868
 869         m = a;
 870         P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m,
 871                 freq->tcall, freq->rcall, freq->err,
 872                 freq->tcall->params.tflush.oldtag);
 873
 874         spin_lock(&m->lock);
 875         cb = NULL;
 876         tag = freq->tcall->params.tflush.oldtag;
 877         req = NULL;
 878         list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
 879                 if (rreq->tag == tag) {
 880                         req = rreq;
 881                         list_del(&req->req_list);
 882                         break;
 883                 }
 884         }
 885         spin_unlock(&m->lock);
 886
 887         if (req) {
 888                 spin_lock(&req->lock);
 889                 req->flush = Flushed;
 890                 spin_unlock(&req->lock);
 891
 892                 if (req->cb)
 893                         (*req->cb) (req, req->cba);
 894                 else
 895                         kfree(req->rcall);
 896
 897                 wake_up(&m->equeue);
 898         }
 899
 900         kfree(freq->tcall);
 901         kfree(freq->rcall);
 902         p9_mux_free_request(m, freq);
 903 }
 904
 905 static int
 906 p9_mux_flush_request(struct p9_conn *m, struct p9_req *req)
 907 {
 908         struct p9_fcall *fc;
 909         struct p9_req *rreq, *rptr;
 910
 911         P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
 912
 913         /* if a response was received for a request, do nothing */
 914         spin_lock(&req->lock);
 915         if (req->rcall || req->err) {
 916                 spin_unlock(&req->lock);
 917                 P9_DPRINTK(P9_DEBUG_MUX,
 918                         "mux %p req %p response already received\n", m, req);
 919                 return 0;
 920         }
 921
 922         req->flush = Flushing;
 923         spin_unlock(&req->lock);
 924
 925         spin_lock(&m->lock);
 926         /* if the request is not sent yet, just remove it from the list */
 927         list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) {
 928                 if (rreq->tag == req->tag) {
 929                         P9_DPRINTK(P9_DEBUG_MUX,
 930                            "mux %p req %p request is not sent yet\n", m, req);
 931                         list_del(&rreq->req_list);
 932                         req->flush = Flushed;
 933                         spin_unlock(&m->lock);
 934                         if (req->cb)
 935                                 (*req->cb) (req, req->cba);
 936                         return 0;
 937                 }
 938         }
 939         spin_unlock(&m->lock);
 940
 941         clear_thread_flag(TIF_SIGPENDING);
 942         fc = p9_create_tflush(req->tag);
 943         p9_send_request(m, fc, p9_mux_flush_cb, m);
 944         return 1;
 945 }
 946
 947 static void
 948 p9_conn_rpc_cb(struct p9_req *req, void *a)
 949 {
 950         struct p9_mux_rpc *r;
 951
 952         P9_DPRINTK(P9_DEBUG_MUX, "req %p r %p\n", req, a);
 953         r = a;
 954         r->rcall = req->rcall;
 955         r->err = req->err;
 956
 957         if (req->flush != None && !req->err)
 958                 r->err = -ERESTARTSYS;
 959
 960         wake_up(&r->wqueue);
 961 }
 962
 963 /**
 964  * p9_fd_rpc- sends 9P request and waits until a response is available.
 965  *      The function can be interrupted.
 966  * @m: mux data
 967  * @tc: request to be sent
 968  * @rc: pointer where a pointer to the response is stored
 969  */
 970 int
 971 p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
 972 {
 973         struct p9_trans_fd *p = t->priv;
 974         struct p9_conn *m = p->conn;
 975         int err, sigpending;
 976         unsigned long flags;
 977         struct p9_req *req;
 978         struct p9_mux_rpc r;
 979
 980         r.err = 0;
 981         r.tcall = tc;
 982         r.rcall = NULL;
 983         r.m = m;
 984         init_waitqueue_head(&r.wqueue);
 985
 986         if (rc)
 987                 *rc = NULL;
 988
 989         sigpending = 0;
 990         if (signal_pending(current)) {
 991                 sigpending = 1;
 992                 clear_thread_flag(TIF_SIGPENDING);
 993         }
 994
 995         req = p9_send_request(m, tc, p9_conn_rpc_cb, &r);
 996         if (IS_ERR(req)) {
 997                 err = PTR_ERR(req);
 998                 P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
 999                 return err;
1000         }
1001
1002         err = wait_event_interruptible(r.wqueue, r.rcall != NULL || r.err < 0);
1003         if (r.err < 0)
1004                 err = r.err;
1005
1006         if (err == -ERESTARTSYS && m->trans->status == Connected
1007                                                         && m->err == 0) {
1008                 if (p9_mux_flush_request(m, req)) {
1009                         /* wait until we get response of the flush message */
1010                         do {
1011                                 clear_thread_flag(TIF_SIGPENDING);
1012                                 err = wait_event_interruptible(r.wqueue,
1013                                         r.rcall || r.err);
1014                         } while (!r.rcall && !r.err && err == -ERESTARTSYS &&
1015                                 m->trans->status == Connected && !m->err);
1016
1017                         err = -ERESTARTSYS;
1018                 }
1019                 sigpending = 1;
1020         }
1021
1022         if (sigpending) {
1023                 spin_lock_irqsave(&current->sighand->siglock, flags);
1024                 recalc_sigpending();
1025                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
1026         }
1027
1028         if (rc)
1029                 *rc = r.rcall;
1030         else
1031                 kfree(r.rcall);
1032
1033         p9_mux_free_request(m, req);
1034         if (err > 0)
1035                 err = -EIO;
1036
1037         return err;
1038 }
1039
1040 #ifdef P9_NONBLOCK
1041 /**
1042  * p9_conn_rpcnb - sends 9P request without waiting for response.
1043  * @m: mux data
1044  * @tc: request to be sent
1045  * @cb: callback function to be called when response arrives
1046  * @cba: value to pass to the callback function
1047  */
1048 int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
1049                    p9_conn_req_callback cb, void *a)
1050 {
1051         int err;
1052         struct p9_req *req;
1053
1054         req = p9_send_request(m, tc, cb, a);
1055         if (IS_ERR(req)) {
1056                 err = PTR_ERR(req);
1057                 P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
1058                 return PTR_ERR(req);
1059         }
1060
1061         P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag);
1062         return 0;
1063 }
1064 #endif /* P9_NONBLOCK */
1065
1066 /**
1067  * p9_conn_cancel - cancel all pending requests with error
1068  * @m: mux data
1069  * @err: error code
1070  */
1071 void p9_conn_cancel(struct p9_conn *m, int err)
1072 {
1073         struct p9_req *req, *rtmp;
1074         LIST_HEAD(cancel_list);
1075
1076         P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
1077         m->err = err;
1078         spin_lock(&m->lock);
1079         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
1080                 list_move(&req->req_list, &cancel_list);
1081         }
1082         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
1083                 list_move(&req->req_list, &cancel_list);
1084         }
1085         spin_unlock(&m->lock);
1086
1087         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
1088                 list_del(&req->req_list);
1089                 if (!req->err)
1090                         req->err = err;
1091
1092                 if (req->cb)
1093                         (*req->cb) (req, req->cba);
1094                 else
1095                         kfree(req->rcall);
1096         }
1097
1098         wake_up(&m->equeue);
1099 }
1100
1101 /**
1102  * v9fs_parse_options - parse mount options into session structure
1103  * @options: options string passed from mount
1104  * @v9ses: existing v9fs session information
1105  *
1106  */
1107
1108 static void parse_opts(char *options, struct p9_fd_opts *opts)
1109 {
1110         char *p;
1111         substring_t args[MAX_OPT_ARGS];
1112         int option;
1113         int ret;
1114
1115         opts->port = P9_PORT;
1116         opts->rfd = ~0;
1117         opts->wfd = ~0;
1118
1119         if (!options)
1120                 return;
1121
1122         while ((p = strsep(&options, ",")) != NULL) {
1123                 int token;
1124                 if (!*p)
1125                         continue;
1126                 token = match_token(p, tokens, args);
1127                 ret = match_int(&args[0], &option);
1128                 if (ret < 0) {
1129                         P9_DPRINTK(P9_DEBUG_ERROR,
1130                          "integer field, but no integer?\n");
1131                         continue;
1132                 }
1133                 switch (token) {
1134                 case Opt_port:
1135                         opts->port = option;
1136                         break;
1137                 case Opt_rfdno:
1138                         opts->rfd = option;
1139                         break;
1140                 case Opt_wfdno:
1141                         opts->wfd = option;
1142                         break;
1143                 default:
1144                         continue;
1145                 }
1146         }
1147 }
1148
1149 static int p9_fd_open(struct p9_trans *trans, int rfd, int wfd)
1150 {
1151         struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
1152                                            GFP_KERNEL);
1153         if (!ts)
1154                 return -ENOMEM;
1155
1156         ts->rd = fget(rfd);
1157         ts->wr = fget(wfd);
1158         if (!ts->rd || !ts->wr) {
1159                 if (ts->rd)
1160                         fput(ts->rd);
1161                 if (ts->wr)
1162                         fput(ts->wr);
1163                 kfree(ts);
1164                 return -EIO;
1165         }
1166
1167         trans->priv = ts;
1168         trans->status = Connected;
1169
1170         return 0;
1171 }
1172
1173 static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
1174 {
1175         int fd, ret;
1176
1177         csocket->sk->sk_allocation = GFP_NOIO;
1178         fd = sock_map_fd(csocket);
1179         if (fd < 0) {
1180                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
1181                 return fd;
1182         }
1183
1184         ret = p9_fd_open(trans, fd, fd);
1185         if (ret < 0) {
1186                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
1187                 sockfd_put(csocket);
1188                 return ret;
1189         }
1190
1191         ((struct p9_trans_fd *)trans->priv)->rd->f_flags |= O_NONBLOCK;
1192
1193         return 0;
1194 }
1195
1196 /**
1197  * p9_fd_read- read from a fd
1198  * @v9ses: session information
1199  * @v: buffer to receive data into
1200  * @len: size of receive buffer
1201  *
1202  */
1203 static int p9_fd_read(struct p9_trans *trans, void *v, int len)
1204 {
1205         int ret;
1206         struct p9_trans_fd *ts = NULL;
1207
1208         if (trans && trans->status != Disconnected)
1209                 ts = trans->priv;
1210
1211         if (!ts)
1212                 return -EREMOTEIO;
1213
1214         if (!(ts->rd->f_flags & O_NONBLOCK))
1215                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
1216
1217         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
1218         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
1219                 trans->status = Disconnected;
1220         return ret;
1221 }
1222
1223 /**
1224  * p9_fd_write - write to a socket
1225  * @v9ses: session information
1226  * @v: buffer to send data from
1227  * @len: size of send buffer
1228  *
1229  */
1230 static int p9_fd_write(struct p9_trans *trans, void *v, int len)
1231 {
1232         int ret;
1233         mm_segment_t oldfs;
1234         struct p9_trans_fd *ts = NULL;
1235
1236         if (trans && trans->status != Disconnected)
1237                 ts = trans->priv;
1238
1239         if (!ts)
1240                 return -EREMOTEIO;
1241
1242         if (!(ts->wr->f_flags & O_NONBLOCK))
1243                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
1244
1245         oldfs = get_fs();
1246         set_fs(get_ds());
1247         /* The cast to a user pointer is valid due to the set_fs() */
1248         ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
1249         set_fs(oldfs);
1250
1251         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
1252                 trans->status = Disconnected;
1253         return ret;
1254 }
1255
1256 static unsigned int
1257 p9_fd_poll(struct p9_trans *trans, struct poll_table_struct *pt)
1258 {
1259         int ret, n;
1260         struct p9_trans_fd *ts = NULL;
1261         mm_segment_t oldfs;
1262
1263         if (trans && trans->status == Connected)
1264                 ts = trans->priv;
1265
1266         if (!ts)
1267                 return -EREMOTEIO;
1268
1269         if (!ts->rd->f_op || !ts->rd->f_op->poll)
1270                 return -EIO;
1271
1272         if (!ts->wr->f_op || !ts->wr->f_op->poll)
1273                 return -EIO;
1274
1275         oldfs = get_fs();
1276         set_fs(get_ds());
1277
1278         ret = ts->rd->f_op->poll(ts->rd, pt);
1279         if (ret < 0)
1280                 goto end;
1281
1282         if (ts->rd != ts->wr) {
1283                 n = ts->wr->f_op->poll(ts->wr, pt);
1284                 if (n < 0) {
1285                         ret = n;
1286                         goto end;
1287                 }
1288                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
1289         }
1290
1291 end:
1292         set_fs(oldfs);
1293         return ret;
1294 }
1295
1296 /**
1297  * p9_fd_close - shutdown socket
1298  * @trans: private socket structure
1299  *
1300  */
1301 static void p9_fd_close(struct p9_trans *trans)
1302 {
1303         struct p9_trans_fd *ts;
1304
1305         if (!trans)
1306                 return;
1307
1308         ts = xchg(&trans->priv, NULL);
1309
1310         if (!ts)
1311                 return;
1312
1313         p9_conn_destroy(ts->conn);
1314
1315         trans->status = Disconnected;
1316         if (ts->rd)
1317                 fput(ts->rd);
1318         if (ts->wr)
1319                 fput(ts->wr);
1320         kfree(ts);
1321 }
1322
1323 static struct p9_trans *
1324 p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu)
1325 {
1326         int err;
1327         struct p9_trans *trans;
1328         struct socket *csocket;
1329         struct sockaddr_in sin_server;
1330         struct p9_fd_opts opts;
1331         struct p9_trans_fd *p;
1332
1333         parse_opts(args, &opts);
1334
1335         csocket = NULL;
1336         trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
1337         if (!trans)
1338                 return ERR_PTR(-ENOMEM);
1339         trans->msize = msize;
1340         trans->extended = dotu;
1341         trans->rpc = p9_fd_rpc;
1342         trans->close = p9_fd_close;
1343
1344         sin_server.sin_family = AF_INET;
1345         sin_server.sin_addr.s_addr = in_aton(addr);
1346         sin_server.sin_port = htons(opts.port);
1347         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
1348
1349         if (!csocket) {
1350                 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
1351                 err = -EIO;
1352                 goto error;
1353         }
1354
1355         err = csocket->ops->connect(csocket,
1356                                     (struct sockaddr *)&sin_server,
1357                                     sizeof(struct sockaddr_in), 0);
1358         if (err < 0) {
1359                 P9_EPRINTK(KERN_ERR,
1360                         "p9_trans_tcp: problem connecting socket to %s\n",
1361                         addr);
1362                 goto error;
1363         }
1364
1365         err = p9_socket_open(trans, csocket);
1366         if (err < 0)
1367                 goto error;
1368
1369         p = (struct p9_trans_fd *) trans->priv;
1370         p->conn = p9_conn_create(trans);
1371         if (IS_ERR(p->conn)) {
1372                 err = PTR_ERR(p->conn);
1373                 p->conn = NULL;
1374                 goto error;
1375         }
1376
1377         return trans;
1378
1379 error:
1380         if (csocket)
1381                 sock_release(csocket);
1382
1383         kfree(trans);
1384         return ERR_PTR(err);
1385 }
1386
1387 static struct p9_trans *
1388 p9_trans_create_unix(const char *addr, char *args, int msize,
1389                                                         unsigned char dotu)
1390 {
1391         int err;
1392         struct socket *csocket;
1393         struct sockaddr_un sun_server;
1394         struct p9_trans *trans;
1395         struct p9_trans_fd *p;
1396
1397         csocket = NULL;
1398         trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
1399         if (!trans)
1400                 return ERR_PTR(-ENOMEM);
1401
1402         trans->rpc = p9_fd_rpc;
1403         trans->close = p9_fd_close;
1404
1405         if (strlen(addr) > UNIX_PATH_MAX) {
1406                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
1407                         addr);
1408                 err = -ENAMETOOLONG;
1409                 goto error;
1410         }
1411
1412         sun_server.sun_family = PF_UNIX;
1413         strcpy(sun_server.sun_path, addr);
1414         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
1415         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1416                         sizeof(struct sockaddr_un) - 1, 0);
1417         if (err < 0) {
1418                 P9_EPRINTK(KERN_ERR,
1419                         "p9_trans_unix: problem connecting socket: %s: %d\n",
1420                         addr, err);
1421                 goto error;
1422         }
1423
1424         err = p9_socket_open(trans, csocket);
1425         if (err < 0)
1426                 goto error;
1427
1428         trans->msize = msize;
1429         trans->extended = dotu;
1430         p = (struct p9_trans_fd *) trans->priv;
1431         p->conn = p9_conn_create(trans);
1432         if (IS_ERR(p->conn)) {
1433                 err = PTR_ERR(p->conn);
1434                 p->conn = NULL;
1435                 goto error;
1436         }
1437
1438         return trans;
1439
1440 error:
1441         if (csocket)
1442                 sock_release(csocket);
1443
1444         kfree(trans);
1445         return ERR_PTR(err);
1446 }
1447
1448 static struct p9_trans *
1449 p9_trans_create_fd(const char *name, char *args, int msize,
1450                                                         unsigned char extended)
1451 {
1452         int err;
1453         struct p9_trans *trans;
1454         struct p9_fd_opts opts;
1455         struct p9_trans_fd *p;
1456
1457         parse_opts(args, &opts);
1458
1459         if (opts.rfd == ~0 || opts.wfd == ~0) {
1460                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
1461                 return ERR_PTR(-ENOPROTOOPT);
1462         }
1463
1464         trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
1465         if (!trans)
1466                 return ERR_PTR(-ENOMEM);
1467
1468         trans->rpc = p9_fd_rpc;
1469         trans->close = p9_fd_close;
1470
1471         err = p9_fd_open(trans, opts.rfd, opts.wfd);
1472         if (err < 0)
1473                 goto error;
1474
1475         trans->msize = msize;
1476         trans->extended = extended;
1477         p = (struct p9_trans_fd *) trans->priv;
1478         p->conn = p9_conn_create(trans);
1479         if (IS_ERR(p->conn)) {
1480                 err = PTR_ERR(p->conn);
1481                 p->conn = NULL;
1482                 goto error;
1483         }
1484
1485         return trans;
1486
1487 error:
1488         kfree(trans);
1489         return ERR_PTR(err);
1490 }
1491
1492 static struct p9_trans_module p9_tcp_trans = {
1493         .name = "tcp",
1494         .maxsize = MAX_SOCK_BUF,
1495         .def = 1,
1496         .create = p9_trans_create_tcp,
1497 };
1498
1499 static struct p9_trans_module p9_unix_trans = {
1500         .name = "unix",
1501         .maxsize = MAX_SOCK_BUF,
1502         .def = 0,
1503         .create = p9_trans_create_unix,
1504 };
1505
1506 static struct p9_trans_module p9_fd_trans = {
1507         .name = "fd",
1508         .maxsize = MAX_SOCK_BUF,
1509         .def = 0,
1510         .create = p9_trans_create_fd,
1511 };
1512
1513 static int __init p9_trans_fd_init(void)
1514 {
1515         int ret = p9_mux_global_init();
1516         if (ret) {
1517                 printk(KERN_WARNING "9p: starting mux failed\n");
1518                 return ret;
1519         }
1520
1521         v9fs_register_trans(&p9_tcp_trans);
1522         v9fs_register_trans(&p9_unix_trans);
1523         v9fs_register_trans(&p9_fd_trans);
1524
1525         return 1;
1526 }
1527
1528 module_init(p9_trans_fd_init);
1529
1530 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
1531 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
1532 MODULE_LICENSE("GPL");