SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/9p/trans_fd.c

   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 MAXPOLLWADDR    2
  48
  49 /**
  50  * struct p9_fd_opts - per-transport options
  51  * @rfd: file descriptor for reading (trans=fd)
  52  * @wfd: file descriptor for writing (trans=fd)
  53  * @port: port to connect to (trans=tcp)
  54  *
  55  */
  56
  57 struct p9_fd_opts {
  58         int rfd;
  59         int wfd;
  60         u16 port;
  61 };
  62
  63 /**
  64  * struct p9_trans_fd - transport state
  65  * @rd: reference to file to read from
  66  * @wr: reference of file to write to
  67  * @conn: connection state reference
  68  *
  69  */
  70
  71 struct p9_trans_fd {
  72         struct file *rd;
  73         struct file *wr;
  74         struct p9_conn *conn;
  75 };
  76
  77 /*
  78   * Option Parsing (code inspired by NFS code)
  79   *  - a little lazy - parse all fd-transport options
  80   */
  81
  82 enum {
  83         /* Options that take integer arguments */
  84         Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
  85 };
  86
  87 static const match_table_t tokens = {
  88         {Opt_port, "port=%u"},
  89         {Opt_rfdno, "rfdno=%u"},
  90         {Opt_wfdno, "wfdno=%u"},
  91         {Opt_err, NULL},
  92 };
  93
  94 enum {
  95         Rworksched = 1,         /* read work scheduled or running */
  96         Rpending = 2,           /* can read */
  97         Wworksched = 4,         /* write work scheduled or running */
  98         Wpending = 8,           /* can write */
  99 };
 100
 101 struct p9_poll_wait {
 102         struct p9_conn *conn;
 103         wait_queue_t wait;
 104         wait_queue_head_t *wait_addr;
 105 };
 106
 107 /**
 108  * struct p9_conn - fd mux connection state information
 109  * @mux_list: list link for mux to manage multiple connections (?)
 110  * @client: reference to client instance for this connection
 111  * @err: error state
 112  * @req_list: accounting for requests which have been sent
 113  * @unsent_req_list: accounting for requests that haven't been sent
 114  * @req: current request being processed (if any)
 115  * @tmp_buf: temporary buffer to read in header
 116  * @rsize: amount to read for current frame
 117  * @rpos: read position in current frame
 118  * @rbuf: current read buffer
 119  * @wpos: write position for current frame
 120  * @wsize: amount of data to write for current frame
 121  * @wbuf: current write buffer
 122  * @poll_wait: array of wait_q's for various worker threads
 123  * @poll_waddr: ????
 124  * @pt: poll state
 125  * @rq: current read work
 126  * @wq: current write work
 127  * @wsched: ????
 128  *
 129  */
 130
 131 struct p9_conn {
 132         struct list_head mux_list;
 133         struct p9_client *client;
 134         int err;
 135         struct list_head req_list;
 136         struct list_head unsent_req_list;
 137         struct p9_req_t *req;
 138         char tmp_buf[7];
 139         int rsize;
 140         int rpos;
 141         char *rbuf;
 142         int wpos;
 143         int wsize;
 144         char *wbuf;
 145         struct list_head poll_pending_link;
 146         struct p9_poll_wait poll_wait[MAXPOLLWADDR];
 147         poll_table pt;
 148         struct work_struct rq;
 149         struct work_struct wq;
 150         unsigned long wsched;
 151 };
 152
 153 static DEFINE_SPINLOCK(p9_poll_lock);
 154 static LIST_HEAD(p9_poll_pending_list);
 155 static struct workqueue_struct *p9_mux_wq;
 156 static struct task_struct *p9_poll_task;
 157
 158 static void p9_mux_poll_stop(struct p9_conn *m)
 159 {
 160         unsigned long flags;
 161         int i;
 162
 163         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 164                 struct p9_poll_wait *pwait = &m->poll_wait[i];
 165
 166                 if (pwait->wait_addr) {
 167                         remove_wait_queue(pwait->wait_addr, &pwait->wait);
 168                         pwait->wait_addr = NULL;
 169                 }
 170         }
 171
 172         spin_lock_irqsave(&p9_poll_lock, flags);
 173         list_del_init(&m->poll_pending_link);
 174         spin_unlock_irqrestore(&p9_poll_lock, flags);
 175 }
 176
 177 static void p9_conn_rpc_cb(struct p9_client *, struct p9_req_t *);
 178
 179 static void p9_mux_flush_cb(struct p9_client *client, struct p9_req_t *freq)
 180 {
 181         struct p9_conn *m = client->trans;
 182         struct p9_req_t *req;
 183
 184         P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m,
 185                 freq->tc, freq->rc, freq->t_err,
 186                 freq->tc->params.tflush.oldtag);
 187
 188         req = p9_tag_lookup(client, freq->tc->params.tflush.oldtag);
 189         if (req) {
 190                 req->status = REQ_STATUS_FLSHD;
 191                 list_del(&req->req_list);
 192                 p9_conn_rpc_cb(client, req);
 193         }
 194
 195         p9_free_req(client, freq);
 196 }
 197
 198 static void p9_conn_rpc_cb(struct p9_client *client, struct p9_req_t *req)
 199 {
 200         P9_DPRINTK(P9_DEBUG_MUX, "req %p\n", req);
 201
 202         if (req->tc->id == P9_TFLUSH) { /* flush callback */
 203                 P9_DPRINTK(P9_DEBUG_MUX, "flush req %p\n", req);
 204                 p9_mux_flush_cb(client, req);
 205         } else {                        /* normal wakeup path */
 206                 P9_DPRINTK(P9_DEBUG_MUX, "normal req %p\n", req);
 207                 if (!req->t_err && (req->status == REQ_STATUS_FLSHD ||
 208                                  req->status == REQ_STATUS_FLSH))
 209                         req->t_err = -ERESTARTSYS;
 210
 211                 wake_up(req->wq);
 212         }
 213 }
 214
 215 /**
 216  * p9_conn_cancel - cancel all pending requests with error
 217  * @m: mux data
 218  * @err: error code
 219  *
 220  */
 221
 222 void p9_conn_cancel(struct p9_conn *m, int err)
 223 {
 224         struct p9_req_t *req, *rtmp;
 225         LIST_HEAD(cancel_list);
 226
 227         P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
 228         m->err = err;
 229         spin_lock(&m->client->lock);
 230         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
 231                 req->status = REQ_STATUS_ERROR;
 232                 if (!req->t_err)
 233                         req->t_err = err;
 234                 list_move(&req->req_list, &cancel_list);
 235         }
 236         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
 237                 req->status = REQ_STATUS_ERROR;
 238                 if (!req->t_err)
 239                         req->t_err = err;
 240                 list_move(&req->req_list, &cancel_list);
 241         }
 242         spin_unlock(&m->client->lock);
 243
 244         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
 245                 list_del(&req->req_list);
 246                 p9_conn_rpc_cb(m->client, req);
 247         }
 248 }
 249
 250 static void process_request(struct p9_conn *m, struct p9_req_t *req)
 251 {
 252         int ecode;
 253         struct p9_str *ename;
 254
 255         if (!req->t_err && req->rc->id == P9_RERROR) {
 256                 ecode = req->rc->params.rerror.errno;
 257                 ename = &req->rc->params.rerror.error;
 258
 259                 P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
 260                                                                 ename->str);
 261
 262                 if (m->client->dotu)
 263                         req->t_err = -ecode;
 264
 265                 if (!req->t_err) {
 266                         req->t_err = p9_errstr2errno(ename->str, ename->len);
 267
 268                         /* string match failed */
 269                         if (!req->t_err) {
 270                                 PRINT_FCALL_ERROR("unknown error", req->rc);
 271                                 req->t_err = -ESERVERFAULT;
 272                         }
 273                 }
 274         } else if (req->tc && req->rc->id != req->tc->id + 1) {
 275                 P9_DPRINTK(P9_DEBUG_ERROR,
 276                                 "fcall mismatch: expected %d, got %d\n",
 277                                 req->tc->id + 1, req->rc->id);
 278                 if (!req->t_err)
 279                         req->t_err = -EIO;
 280         }
 281 }
 282
 283 static unsigned int
 284 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
 285 {
 286         int ret, n;
 287         struct p9_trans_fd *ts = NULL;
 288
 289         if (client && client->status == Connected)
 290                 ts = client->trans;
 291
 292         if (!ts)
 293                 return -EREMOTEIO;
 294
 295         if (!ts->rd->f_op || !ts->rd->f_op->poll)
 296                 return -EIO;
 297
 298         if (!ts->wr->f_op || !ts->wr->f_op->poll)
 299                 return -EIO;
 300
 301         ret = ts->rd->f_op->poll(ts->rd, pt);
 302         if (ret < 0)
 303                 return ret;
 304
 305         if (ts->rd != ts->wr) {
 306                 n = ts->wr->f_op->poll(ts->wr, pt);
 307                 if (n < 0)
 308                         return n;
 309                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
 310         }
 311
 312         return ret;
 313 }
 314
 315 /**
 316  * p9_fd_read- read from a fd
 317  * @client: client instance
 318  * @v: buffer to receive data into
 319  * @len: size of receive buffer
 320  *
 321  */
 322
 323 static int p9_fd_read(struct p9_client *client, void *v, int len)
 324 {
 325         int ret;
 326         struct p9_trans_fd *ts = NULL;
 327
 328         if (client && client->status != Disconnected)
 329                 ts = client->trans;
 330
 331         if (!ts)
 332                 return -EREMOTEIO;
 333
 334         if (!(ts->rd->f_flags & O_NONBLOCK))
 335                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
 336
 337         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
 338         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 339                 client->status = Disconnected;
 340         return ret;
 341 }
 342
 343 /**
 344  * p9_read_work - called when there is some data to be read from a transport
 345  * @work: container of work to be done
 346  *
 347  */
 348
 349 static void p9_read_work(struct work_struct *work)
 350 {
 351         int n, err;
 352         struct p9_conn *m;
 353
 354         m = container_of(work, struct p9_conn, rq);
 355
 356         if (m->err < 0)
 357                 return;
 358
 359         P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
 360
 361         if (!m->rbuf) {
 362                 m->rbuf = m->tmp_buf;
 363                 m->rpos = 0;
 364                 m->rsize = 7; /* start by reading header */
 365         }
 366
 367         clear_bit(Rpending, &m->wsched);
 368         P9_DPRINTK(P9_DEBUG_MUX, "read mux %p pos %d size: %d = %d\n", m,
 369                                         m->rpos, m->rsize, m->rsize-m->rpos);
 370         err = p9_fd_read(m->client, m->rbuf + m->rpos,
 371                                                 m->rsize - m->rpos);
 372         P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err);
 373         if (err == -EAGAIN) {
 374                 clear_bit(Rworksched, &m->wsched);
 375                 return;
 376         }
 377
 378         if (err <= 0)
 379                 goto error;
 380
 381         m->rpos += err;
 382
 383         if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
 384                 u16 tag;
 385                 P9_DPRINTK(P9_DEBUG_MUX, "got new header\n");
 386
 387                 n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
 388                 if (n >= m->client->msize) {
 389                         P9_DPRINTK(P9_DEBUG_ERROR,
 390                                 "requested packet size too big: %d\n", n);
 391                         err = -EIO;
 392                         goto error;
 393                 }
 394
 395                 tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
 396                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p pkt: size: %d bytes tag: %d\n",
 397                                                                  m, n, tag);
 398
 399                 m->req = p9_tag_lookup(m->client, tag);
 400                 if (!m->req) {
 401                         P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
 402                                                                  tag);
 403                         err = -EIO;
 404                         goto error;
 405                 }
 406
 407                 if (m->req->rc == NULL) {
 408                         m->req->rc = kmalloc(sizeof(struct p9_fcall) +
 409                                                 m->client->msize, GFP_KERNEL);
 410                         if (!m->req->rc) {
 411                                 m->req = NULL;
 412                                 err = -ENOMEM;
 413                                 goto error;
 414                         }
 415                 }
 416                 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
 417                 memcpy(m->rbuf, m->tmp_buf, m->rsize);
 418                 m->rsize = n;
 419         }
 420
 421         /* not an else because some packets (like clunk) have no payload */
 422         if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
 423                 P9_DPRINTK(P9_DEBUG_MUX, "got new packet\n");
 424                 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
 425                 err = p9_deserialize_fcall(m->rbuf, m->rsize, m->req->rc,
 426                                                         m->client->dotu);
 427                 if (err < 0) {
 428                         m->req = NULL;
 429                         goto error;
 430                 }
 431
 432 #ifdef CONFIG_NET_9P_DEBUG
 433                 if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
 434                         char buf[150];
 435
 436                         p9_printfcall(buf, sizeof(buf), m->req->rc,
 437                                 m->client->dotu);
 438                         printk(KERN_NOTICE ">>> %p %s\n", m, buf);
 439                 }
 440 #endif
 441
 442                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m,
 443                                         m->req->rc->id, m->req->rc->tag);
 444
 445                 m->rbuf = NULL;
 446                 m->rpos = 0;
 447                 m->rsize = 0;
 448
 449                 if (m->req->status != REQ_STATUS_FLSH) {
 450                         list_del(&m->req->req_list);
 451                         m->req->status = REQ_STATUS_RCVD;
 452                 }
 453
 454                 process_request(m, m->req);
 455
 456                 if (m->req->status != REQ_STATUS_FLSH)
 457                         p9_conn_rpc_cb(m->client, m->req);
 458
 459                 m->req = NULL;
 460         }
 461
 462         if (!list_empty(&m->req_list)) {
 463                 if (test_and_clear_bit(Rpending, &m->wsched))
 464                         n = POLLIN;
 465                 else
 466                         n = p9_fd_poll(m->client, NULL);
 467
 468                 if (n & POLLIN) {
 469                         P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
 470                         queue_work(p9_mux_wq, &m->rq);
 471                 } else
 472                         clear_bit(Rworksched, &m->wsched);
 473         } else
 474                 clear_bit(Rworksched, &m->wsched);
 475
 476         return;
 477 error:
 478         p9_conn_cancel(m, err);
 479         clear_bit(Rworksched, &m->wsched);
 480 }
 481
 482 /**
 483  * p9_fd_write - write to a socket
 484  * @client: client instance
 485  * @v: buffer to send data from
 486  * @len: size of send buffer
 487  *
 488  */
 489
 490 static int p9_fd_write(struct p9_client *client, void *v, int len)
 491 {
 492         int ret;
 493         mm_segment_t oldfs;
 494         struct p9_trans_fd *ts = NULL;
 495
 496         if (client && client->status != Disconnected)
 497                 ts = client->trans;
 498
 499         if (!ts)
 500                 return -EREMOTEIO;
 501
 502         if (!(ts->wr->f_flags & O_NONBLOCK))
 503                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
 504
 505         oldfs = get_fs();
 506         set_fs(get_ds());
 507         /* The cast to a user pointer is valid due to the set_fs() */
 508         ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
 509         set_fs(oldfs);
 510
 511         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 512                 client->status = Disconnected;
 513         return ret;
 514 }
 515
 516 /**
 517  * p9_write_work - called when a transport can send some data
 518  * @work: container for work to be done
 519  *
 520  */
 521
 522 static void p9_write_work(struct work_struct *work)
 523 {
 524         int n, err;
 525         struct p9_conn *m;
 526         struct p9_req_t *req;
 527
 528         m = container_of(work, struct p9_conn, wq);
 529
 530         if (m->err < 0) {
 531                 clear_bit(Wworksched, &m->wsched);
 532                 return;
 533         }
 534
 535         if (!m->wsize) {
 536                 if (list_empty(&m->unsent_req_list)) {
 537                         clear_bit(Wworksched, &m->wsched);
 538                         return;
 539                 }
 540
 541                 spin_lock(&m->client->lock);
 542                 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
 543                                req_list);
 544                 req->status = REQ_STATUS_SENT;
 545                 list_move_tail(&req->req_list, &m->req_list);
 546
 547                 m->wbuf = req->tc->sdata;
 548                 m->wsize = req->tc->size;
 549                 m->wpos = 0;
 550                 spin_unlock(&m->client->lock);
 551         }
 552
 553         P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos,
 554                                                                 m->wsize);
 555         clear_bit(Wpending, &m->wsched);
 556         err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
 557         P9_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
 558         if (err == -EAGAIN) {
 559                 clear_bit(Wworksched, &m->wsched);
 560                 return;
 561         }
 562
 563         if (err < 0)
 564                 goto error;
 565         else if (err == 0) {
 566                 err = -EREMOTEIO;
 567                 goto error;
 568         }
 569
 570         m->wpos += err;
 571         if (m->wpos == m->wsize)
 572                 m->wpos = m->wsize = 0;
 573
 574         if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
 575                 if (test_and_clear_bit(Wpending, &m->wsched))
 576                         n = POLLOUT;
 577                 else
 578                         n = p9_fd_poll(m->client, NULL);
 579
 580                 if (n & POLLOUT) {
 581                         P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
 582                         queue_work(p9_mux_wq, &m->wq);
 583                 } else
 584                         clear_bit(Wworksched, &m->wsched);
 585         } else
 586                 clear_bit(Wworksched, &m->wsched);
 587
 588         return;
 589
 590 error:
 591         p9_conn_cancel(m, err);
 592         clear_bit(Wworksched, &m->wsched);
 593 }
 594
 595 static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
 596 {
 597         struct p9_poll_wait *pwait =
 598                 container_of(wait, struct p9_poll_wait, wait);
 599         struct p9_conn *m = pwait->conn;
 600         unsigned long flags;
 601         DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
 602
 603         spin_lock_irqsave(&p9_poll_lock, flags);
 604         if (list_empty(&m->poll_pending_link))
 605                 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
 606         spin_unlock_irqrestore(&p9_poll_lock, flags);
 607
 608         /* perform the default wake up operation */
 609         return default_wake_function(&dummy_wait, mode, sync, key);
 610 }
 611
 612 /**
 613  * p9_pollwait - add poll task to the wait queue
 614  * @filp: file pointer being polled
 615  * @wait_address: wait_q to block on
 616  * @p: poll state
 617  *
 618  * called by files poll operation to add v9fs-poll task to files wait queue
 619  */
 620
 621 static void
 622 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
 623 {
 624         struct p9_conn *m = container_of(p, struct p9_conn, pt);
 625         struct p9_poll_wait *pwait = NULL;
 626         int i;
 627
 628         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 629                 if (m->poll_wait[i].wait_addr == NULL) {
 630                         pwait = &m->poll_wait[i];
 631                         break;
 632                 }
 633         }
 634
 635         if (!pwait) {
 636                 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
 637                 return;
 638         }
 639
 640         if (!wait_address) {
 641                 P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
 642                 pwait->wait_addr = ERR_PTR(-EIO);
 643                 return;
 644         }
 645
 646         pwait->conn = m;
 647         pwait->wait_addr = wait_address;
 648         init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
 649         add_wait_queue(wait_address, &pwait->wait);
 650 }
 651
 652 /**
 653  * p9_conn_create - allocate and initialize the per-session mux data
 654  * @client: client instance
 655  *
 656  * Note: Creates the polling task if this is the first session.
 657  */
 658
 659 static struct p9_conn *p9_conn_create(struct p9_client *client)
 660 {
 661         int i, n;
 662         struct p9_conn *m;
 663
 664         P9_DPRINTK(P9_DEBUG_MUX, "client %p msize %d\n", client, client->msize);
 665         m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
 666         if (!m)
 667                 return ERR_PTR(-ENOMEM);
 668
 669         INIT_LIST_HEAD(&m->mux_list);
 670         m->client = client;
 671
 672         INIT_LIST_HEAD(&m->req_list);
 673         INIT_LIST_HEAD(&m->unsent_req_list);
 674         INIT_WORK(&m->rq, p9_read_work);
 675         INIT_WORK(&m->wq, p9_write_work);
 676         INIT_LIST_HEAD(&m->poll_pending_link);
 677         init_poll_funcptr(&m->pt, p9_pollwait);
 678
 679         n = p9_fd_poll(client, &m->pt);
 680         if (n & POLLIN) {
 681                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
 682                 set_bit(Rpending, &m->wsched);
 683         }
 684
 685         if (n & POLLOUT) {
 686                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
 687                 set_bit(Wpending, &m->wsched);
 688         }
 689
 690         for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
 691                 if (IS_ERR(m->poll_wait[i].wait_addr)) {
 692                         p9_mux_poll_stop(m);
 693                         kfree(m);
 694                         /* return the error code */
 695                         return (void *)m->poll_wait[i].wait_addr;
 696                 }
 697         }
 698
 699         return m;
 700 }
 701
 702 /**
 703  * p9_poll_mux - polls a mux and schedules read or write works if necessary
 704  * @m: connection to poll
 705  *
 706  */
 707
 708 static void p9_poll_mux(struct p9_conn *m)
 709 {
 710         int n;
 711
 712         if (m->err < 0)
 713                 return;
 714
 715         n = p9_fd_poll(m->client, NULL);
 716         if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
 717                 P9_DPRINTK(P9_DEBUG_MUX, "error mux %p err %d\n", m, n);
 718                 if (n >= 0)
 719                         n = -ECONNRESET;
 720                 p9_conn_cancel(m, n);
 721         }
 722
 723         if (n & POLLIN) {
 724                 set_bit(Rpending, &m->wsched);
 725                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
 726                 if (!test_and_set_bit(Rworksched, &m->wsched)) {
 727                         P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
 728                         queue_work(p9_mux_wq, &m->rq);
 729                 }
 730         }
 731
 732         if (n & POLLOUT) {
 733                 set_bit(Wpending, &m->wsched);
 734                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
 735                 if ((m->wsize || !list_empty(&m->unsent_req_list))
 736                     && !test_and_set_bit(Wworksched, &m->wsched)) {
 737                         P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
 738                         queue_work(p9_mux_wq, &m->wq);
 739                 }
 740         }
 741 }
 742
 743 /**
 744  * p9_send_request - send 9P request
 745  * The function can sleep until the request is scheduled for sending.
 746  * The function can be interrupted. Return from the function is not
 747  * a guarantee that the request is sent successfully. Can return errors
 748  * that can be retrieved by PTR_ERR macros.
 749  *
 750  * @m: mux data
 751  * @tc: request to be sent
 752  *
 753  */
 754
 755 static struct p9_req_t *p9_send_request(struct p9_conn *m, struct p9_fcall *tc)
 756 {
 757         int tag;
 758         int n;
 759         struct p9_req_t *req;
 760
 761         P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
 762                 tc, tc->id);
 763         if (m->err < 0)
 764                 return ERR_PTR(m->err);
 765
 766         tag = P9_NOTAG;
 767         if (tc->id != P9_TVERSION) {
 768                 tag = p9_idpool_get(m->client->tagpool);
 769                 if (tag < 0)
 770                         return ERR_PTR(-ENOMEM);
 771         }
 772
 773         p9_set_tag(tc, tag);
 774
 775         req = p9_tag_alloc(m->client, tag);
 776
 777 #ifdef CONFIG_NET_9P_DEBUG
 778         if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
 779                 char buf[150];
 780
 781                 p9_printfcall(buf, sizeof(buf), tc, m->client->dotu);
 782                 printk(KERN_NOTICE "<<< %p %s\n", m, buf);
 783         }
 784 #endif
 785
 786         req->tag = tag;
 787         req->tc = tc;
 788         req->rc = NULL;
 789         req->t_err = 0;
 790         req->status = REQ_STATUS_UNSENT;
 791
 792         spin_lock(&m->client->lock);
 793         list_add_tail(&req->req_list, &m->unsent_req_list);
 794         spin_unlock(&m->client->lock);
 795
 796         if (test_and_clear_bit(Wpending, &m->wsched))
 797                 n = POLLOUT;
 798         else
 799                 n = p9_fd_poll(m->client, NULL);
 800
 801         if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
 802                 queue_work(p9_mux_wq, &m->wq);
 803
 804         return req;
 805 }
 806
 807 static int
 808 p9_mux_flush_request(struct p9_conn *m, struct p9_req_t *req)
 809 {
 810         struct p9_fcall *fc;
 811         struct p9_req_t *rreq, *rptr;
 812
 813         P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
 814
 815         /* if a response was received for a request, do nothing */
 816         if (req->rc || req->t_err) {
 817                 P9_DPRINTK(P9_DEBUG_MUX,
 818                         "mux %p req %p response already received\n", m, req);
 819                 return 0;
 820         }
 821
 822         req->status = REQ_STATUS_FLSH;
 823
 824         spin_lock(&m->client->lock);
 825         /* if the request is not sent yet, just remove it from the list */
 826         list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) {
 827                 if (rreq->tag == req->tag) {
 828                         P9_DPRINTK(P9_DEBUG_MUX,
 829                            "mux %p req %p request is not sent yet\n", m, req);
 830                         list_del(&rreq->req_list);
 831                         req->status = REQ_STATUS_FLSHD;
 832                         spin_unlock(&m->client->lock);
 833                         p9_conn_rpc_cb(m->client, req);
 834                         return 0;
 835                 }
 836         }
 837         spin_unlock(&m->client->lock);
 838
 839         clear_thread_flag(TIF_SIGPENDING);
 840         fc = p9_create_tflush(req->tag);
 841         p9_send_request(m, fc);
 842         return 1;
 843 }
 844
 845 /**
 846  * p9_fd_rpc- sends 9P request and waits until a response is available.
 847  *      The function can be interrupted.
 848  * @client: client instance
 849  * @tc: request to be sent
 850  * @rc: pointer where a pointer to the response is stored
 851  *
 852  */
 853
 854 int
 855 p9_fd_rpc(struct p9_client *client, struct p9_fcall *tc, struct p9_fcall **rc)
 856 {
 857         struct p9_trans_fd *p = client->trans;
 858         struct p9_conn *m = p->conn;
 859         int err, sigpending;
 860         unsigned long flags;
 861         struct p9_req_t *req;
 862
 863         if (rc)
 864                 *rc = NULL;
 865
 866         sigpending = 0;
 867         if (signal_pending(current)) {
 868                 sigpending = 1;
 869                 clear_thread_flag(TIF_SIGPENDING);
 870         }
 871
 872         req = p9_send_request(m, tc);
 873         if (IS_ERR(req)) {
 874                 err = PTR_ERR(req);
 875                 P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
 876                 return err;
 877         }
 878
 879         err = wait_event_interruptible(*req->wq, req->rc != NULL ||
 880                                                                 req->t_err < 0);
 881         if (req->t_err < 0)
 882                 err = req->t_err;
 883
 884         if (err == -ERESTARTSYS && client->status == Connected
 885                                                         && m->err == 0) {
 886                 if (p9_mux_flush_request(m, req)) {
 887                         /* wait until we get response of the flush message */
 888                         do {
 889                                 clear_thread_flag(TIF_SIGPENDING);
 890                                 err = wait_event_interruptible(*req->wq,
 891                                         req->rc || req->t_err);
 892                         } while (!req->rc && !req->t_err &&
 893                                         err == -ERESTARTSYS &&
 894                                         client->status == Connected && !m->err);
 895
 896                         err = -ERESTARTSYS;
 897                 }
 898                 sigpending = 1;
 899         }
 900
 901         if (sigpending) {
 902                 spin_lock_irqsave(&current->sighand->siglock, flags);
 903                 recalc_sigpending();
 904                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 905         }
 906
 907         if (rc)
 908                 *rc = req->rc;
 909         else
 910                 kfree(req->rc);
 911
 912         p9_free_req(client, req);
 913         if (err > 0)
 914                 err = -EIO;
 915
 916         return err;
 917 }
 918
 919 /**
 920  * parse_options - parse mount options into session structure
 921  * @options: options string passed from mount
 922  * @opts: transport-specific structure to parse options into
 923  *
 924  * Returns 0 upon success, -ERRNO upon failure
 925  */
 926
 927 static int parse_opts(char *params, struct p9_fd_opts *opts)
 928 {
 929         char *p;
 930         substring_t args[MAX_OPT_ARGS];
 931         int option;
 932         char *options;
 933         int ret;
 934
 935         opts->port = P9_PORT;
 936         opts->rfd = ~0;
 937         opts->wfd = ~0;
 938
 939         if (!params)
 940                 return 0;
 941
 942         options = kstrdup(params, GFP_KERNEL);
 943         if (!options) {
 944                 P9_DPRINTK(P9_DEBUG_ERROR,
 945                                 "failed to allocate copy of option string\n");
 946                 return -ENOMEM;
 947         }
 948
 949         while ((p = strsep(&options, ",")) != NULL) {
 950                 int token;
 951                 int r;
 952                 if (!*p)
 953                         continue;
 954                 token = match_token(p, tokens, args);
 955                 r = match_int(&args[0], &option);
 956                 if (r < 0) {
 957                         P9_DPRINTK(P9_DEBUG_ERROR,
 958                          "integer field, but no integer?\n");
 959                         ret = r;
 960                         continue;
 961                 }
 962                 switch (token) {
 963                 case Opt_port:
 964                         opts->port = option;
 965                         break;
 966                 case Opt_rfdno:
 967                         opts->rfd = option;
 968                         break;
 969                 case Opt_wfdno:
 970                         opts->wfd = option;
 971                         break;
 972                 default:
 973                         continue;
 974                 }
 975         }
 976         kfree(options);
 977         return 0;
 978 }
 979
 980 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
 981 {
 982         struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
 983                                            GFP_KERNEL);
 984         if (!ts)
 985                 return -ENOMEM;
 986
 987         ts->rd = fget(rfd);
 988         ts->wr = fget(wfd);
 989         if (!ts->rd || !ts->wr) {
 990                 if (ts->rd)
 991                         fput(ts->rd);
 992                 if (ts->wr)
 993                         fput(ts->wr);
 994                 kfree(ts);
 995                 return -EIO;
 996         }
 997
 998         client->trans = ts;
 999         client->status = Connected;
1000
1001         return 0;
1002 }
1003
1004 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
1005 {
1006         int fd, ret;
1007
1008         csocket->sk->sk_allocation = GFP_NOIO;
1009         fd = sock_map_fd(csocket, 0);
1010         if (fd < 0) {
1011                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
1012                 return fd;
1013         }
1014
1015         ret = p9_fd_open(client, fd, fd);
1016         if (ret < 0) {
1017                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
1018                 sockfd_put(csocket);
1019                 return ret;
1020         }
1021
1022         ((struct p9_trans_fd *)client->trans)->rd->f_flags |= O_NONBLOCK;
1023
1024         return 0;
1025 }
1026
1027 /**
1028  * p9_mux_destroy - cancels all pending requests and frees mux resources
1029  * @m: mux to destroy
1030  *
1031  */
1032
1033 static void p9_conn_destroy(struct p9_conn *m)
1034 {
1035         P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
1036                 m->mux_list.prev, m->mux_list.next);
1037
1038         p9_mux_poll_stop(m);
1039         cancel_work_sync(&m->rq);
1040         cancel_work_sync(&m->wq);
1041
1042         p9_conn_cancel(m, -ECONNRESET);
1043
1044         m->client = NULL;
1045         kfree(m);
1046 }
1047
1048 /**
1049  * p9_fd_close - shutdown file descriptor transport
1050  * @client: client instance
1051  *
1052  */
1053
1054 static void p9_fd_close(struct p9_client *client)
1055 {
1056         struct p9_trans_fd *ts;
1057
1058         if (!client)
1059                 return;
1060
1061         ts = client->trans;
1062         if (!ts)
1063                 return;
1064
1065         client->status = Disconnected;
1066
1067         p9_conn_destroy(ts->conn);
1068
1069         if (ts->rd)
1070                 fput(ts->rd);
1071         if (ts->wr)
1072                 fput(ts->wr);
1073
1074         kfree(ts);
1075 }
1076
1077 /*
1078  * stolen from NFS - maybe should be made a generic function?
1079  */
1080 static inline int valid_ipaddr4(const char *buf)
1081 {
1082         int rc, count, in[4];
1083
1084         rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
1085         if (rc != 4)
1086                 return -EINVAL;
1087         for (count = 0; count < 4; count++) {
1088                 if (in[count] > 255)
1089                         return -EINVAL;
1090         }
1091         return 0;
1092 }
1093
1094 static int
1095 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
1096 {
1097         int err;
1098         struct socket *csocket;
1099         struct sockaddr_in sin_server;
1100         struct p9_fd_opts opts;
1101         struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
1102
1103         err = parse_opts(args, &opts);
1104         if (err < 0)
1105                 return err;
1106
1107         if (valid_ipaddr4(addr) < 0)
1108                 return -EINVAL;
1109
1110         csocket = NULL;
1111
1112         sin_server.sin_family = AF_INET;
1113         sin_server.sin_addr.s_addr = in_aton(addr);
1114         sin_server.sin_port = htons(opts.port);
1115         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
1116
1117         if (!csocket) {
1118                 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
1119                 err = -EIO;
1120                 goto error;
1121         }
1122
1123         err = csocket->ops->connect(csocket,
1124                                     (struct sockaddr *)&sin_server,
1125                                     sizeof(struct sockaddr_in), 0);
1126         if (err < 0) {
1127                 P9_EPRINTK(KERN_ERR,
1128                         "p9_trans_tcp: problem connecting socket to %s\n",
1129                         addr);
1130                 goto error;
1131         }
1132
1133         err = p9_socket_open(client, csocket);
1134         if (err < 0)
1135                 goto error;
1136
1137         p = (struct p9_trans_fd *) client->trans;
1138         p->conn = p9_conn_create(client);
1139         if (IS_ERR(p->conn)) {
1140                 err = PTR_ERR(p->conn);
1141                 p->conn = NULL;
1142                 goto error;
1143         }
1144
1145         return 0;
1146
1147 error:
1148         if (csocket)
1149                 sock_release(csocket);
1150
1151         kfree(p);
1152
1153         return err;
1154 }
1155
1156 static int
1157 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
1158 {
1159         int err;
1160         struct socket *csocket;
1161         struct sockaddr_un sun_server;
1162         struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
1163
1164         csocket = NULL;
1165
1166         if (strlen(addr) > UNIX_PATH_MAX) {
1167                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
1168                         addr);
1169                 err = -ENAMETOOLONG;
1170                 goto error;
1171         }
1172
1173         sun_server.sun_family = PF_UNIX;
1174         strcpy(sun_server.sun_path, addr);
1175         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
1176         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1177                         sizeof(struct sockaddr_un) - 1, 0);
1178         if (err < 0) {
1179                 P9_EPRINTK(KERN_ERR,
1180                         "p9_trans_unix: problem connecting socket: %s: %d\n",
1181                         addr, err);
1182                 goto error;
1183         }
1184
1185         err = p9_socket_open(client, csocket);
1186         if (err < 0)
1187                 goto error;
1188
1189         p = (struct p9_trans_fd *) client->trans;
1190         p->conn = p9_conn_create(client);
1191         if (IS_ERR(p->conn)) {
1192                 err = PTR_ERR(p->conn);
1193                 p->conn = NULL;
1194                 goto error;
1195         }
1196
1197         return 0;
1198
1199 error:
1200         if (csocket)
1201                 sock_release(csocket);
1202
1203         kfree(p);
1204         return err;
1205 }
1206
1207 static int
1208 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1209 {
1210         int err;
1211         struct p9_fd_opts opts;
1212         struct p9_trans_fd *p = NULL; /* this get allocated in p9_fd_open */
1213
1214         parse_opts(args, &opts);
1215
1216         if (opts.rfd == ~0 || opts.wfd == ~0) {
1217                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
1218                 return -ENOPROTOOPT;
1219         }
1220
1221         err = p9_fd_open(client, opts.rfd, opts.wfd);
1222         if (err < 0)
1223                 goto error;
1224
1225         p = (struct p9_trans_fd *) client->trans;
1226         p->conn = p9_conn_create(client);
1227         if (IS_ERR(p->conn)) {
1228                 err = PTR_ERR(p->conn);
1229                 p->conn = NULL;
1230                 goto error;
1231         }
1232
1233         return 0;
1234
1235 error:
1236         kfree(p);
1237         return err;
1238 }
1239
1240 static struct p9_trans_module p9_tcp_trans = {
1241         .name = "tcp",
1242         .maxsize = MAX_SOCK_BUF,
1243         .def = 1,
1244         .create = p9_fd_create_tcp,
1245         .close = p9_fd_close,
1246         .rpc = p9_fd_rpc,
1247         .owner = THIS_MODULE,
1248 };
1249
1250 static struct p9_trans_module p9_unix_trans = {
1251         .name = "unix",
1252         .maxsize = MAX_SOCK_BUF,
1253         .def = 0,
1254         .create = p9_fd_create_unix,
1255         .close = p9_fd_close,
1256         .rpc = p9_fd_rpc,
1257         .owner = THIS_MODULE,
1258 };
1259
1260 static struct p9_trans_module p9_fd_trans = {
1261         .name = "fd",
1262         .maxsize = MAX_SOCK_BUF,
1263         .def = 0,
1264         .create = p9_fd_create,
1265         .close = p9_fd_close,
1266         .rpc = p9_fd_rpc,
1267         .owner = THIS_MODULE,
1268 };
1269
1270 /**
1271  * p9_poll_proc - poll worker thread
1272  * @a: thread state and arguments
1273  *
1274  * polls all v9fs transports for new events and queues the appropriate
1275  * work to the work queue
1276  *
1277  */
1278
1279 static int p9_poll_proc(void *a)
1280 {
1281         unsigned long flags;
1282
1283         P9_DPRINTK(P9_DEBUG_MUX, "start %p\n", current);
1284  repeat:
1285         spin_lock_irqsave(&p9_poll_lock, flags);
1286         while (!list_empty(&p9_poll_pending_list)) {
1287                 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1288                                                         struct p9_conn,
1289                                                         poll_pending_link);
1290                 list_del_init(&conn->poll_pending_link);
1291                 spin_unlock_irqrestore(&p9_poll_lock, flags);
1292
1293                 p9_poll_mux(conn);
1294
1295                 spin_lock_irqsave(&p9_poll_lock, flags);
1296         }
1297         spin_unlock_irqrestore(&p9_poll_lock, flags);
1298
1299         set_current_state(TASK_INTERRUPTIBLE);
1300         if (list_empty(&p9_poll_pending_list)) {
1301                 P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
1302                 schedule();
1303         }
1304         __set_current_state(TASK_RUNNING);
1305
1306         if (!kthread_should_stop())
1307                 goto repeat;
1308
1309         P9_DPRINTK(P9_DEBUG_MUX, "finish\n");
1310         return 0;
1311 }
1312
1313 int p9_trans_fd_init(void)
1314 {
1315         p9_mux_wq = create_workqueue("v9fs");
1316         if (!p9_mux_wq) {
1317                 printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
1318                 return -ENOMEM;
1319         }
1320
1321         p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll");
1322         if (IS_ERR(p9_poll_task)) {
1323                 destroy_workqueue(p9_mux_wq);
1324                 printk(KERN_WARNING "v9fs: mux: creating poll task failed\n");
1325                 return PTR_ERR(p9_poll_task);
1326         }
1327
1328         v9fs_register_trans(&p9_tcp_trans);
1329         v9fs_register_trans(&p9_unix_trans);
1330         v9fs_register_trans(&p9_fd_trans);
1331
1332         return 0;
1333 }
1334
1335 void p9_trans_fd_exit(void)
1336 {
1337         kthread_stop(p9_poll_task);
1338         v9fs_unregister_trans(&p9_tcp_trans);
1339         v9fs_unregister_trans(&p9_unix_trans);
1340         v9fs_unregister_trans(&p9_fd_trans);
1341
1342         destroy_workqueue(p9_mux_wq);
1343 }