net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/fs.h>
  29 #include <linux/poll.h>
  30 #include <linux/idr.h>
  31 #include <linux/mutex.h>
  32 #include <linux/sched.h>
  33 #include <linux/uaccess.h>
  34 #include <net/9p/9p.h>
  35 #include <linux/parser.h>
  36 #include <net/9p/client.h>
  37 #include <net/9p/transport.h>
  38 #include "protocol.h"
  39
  40 /*
  41   * Client Option Parsing (code inspired by NFS code)
  42   *  - a little lazy - parse all client options
  43   */
  44
  45 enum {
  46         Opt_msize,
  47         Opt_trans,
  48         Opt_legacy,
  49         Opt_err,
  50 };
  51
  52 static const match_table_t tokens = {
  53         {Opt_msize, "msize=%u"},
  54         {Opt_legacy, "noextend"},
  55         {Opt_trans, "trans=%s"},
  56         {Opt_err, NULL},
  57 };
  58
  59 static struct p9_req_t *
  60 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
  61
  62 /**
  63  * v9fs_parse_options - parse mount options into session structure
  64  * @options: options string passed from mount
  65  * @v9ses: existing v9fs session information
  66  *
  67  * Return 0 upon success, -ERRNO upon failure
  68  */
  69
  70 static int parse_opts(char *opts, struct p9_client *clnt)
  71 {
  72         char *options;
  73         char *p;
  74         substring_t args[MAX_OPT_ARGS];
  75         int option;
  76         int ret = 0;
  77
  78         clnt->dotu = 1;
  79         clnt->msize = 8192;
  80
  81         if (!opts)
  82                 return 0;
  83
  84         options = kstrdup(opts, GFP_KERNEL);
  85         if (!options) {
  86                 P9_DPRINTK(P9_DEBUG_ERROR,
  87                                 "failed to allocate copy of option string\n");
  88                 return -ENOMEM;
  89         }
  90
  91         while ((p = strsep(&options, ",")) != NULL) {
  92                 int token;
  93                 if (!*p)
  94                         continue;
  95                 token = match_token(p, tokens, args);
  96                 if (token < Opt_trans) {
  97                         int r = match_int(&args[0], &option);
  98                         if (r < 0) {
  99                                 P9_DPRINTK(P9_DEBUG_ERROR,
 100                                         "integer field, but no integer?\n");
 101                                 ret = r;
 102                                 continue;
 103                         }
 104                 }
 105                 switch (token) {
 106                 case Opt_msize:
 107                         clnt->msize = option;
 108                         break;
 109                 case Opt_trans:
 110                         clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
 111                         break;
 112                 case Opt_legacy:
 113                         clnt->dotu = 0;
 114                         break;
 115                 default:
 116                         continue;
 117                 }
 118         }
 119
 120         if (!clnt->trans_mod)
 121                 clnt->trans_mod = v9fs_get_default_trans();
 122
 123         kfree(options);
 124         return ret;
 125 }
 126
 127 /**
 128  * p9_tag_alloc - lookup/allocate a request by tag
 129  * @c: client session to lookup tag within
 130  * @tag: numeric id for transaction
 131  *
 132  * this is a simple array lookup, but will grow the
 133  * request_slots as necessary to accomodate transaction
 134  * ids which did not previously have a slot.
 135  *
 136  * this code relies on the client spinlock to manage locks, its
 137  * possible we should switch to something else, but I'd rather
 138  * stick with something low-overhead for the common case.
 139  *
 140  */
 141
 142 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
 143 {
 144         unsigned long flags;
 145         int row, col;
 146         struct p9_req_t *req;
 147
 148         /* This looks up the original request by tag so we know which
 149          * buffer to read the data into */
 150         tag++;
 151
 152         if (tag >= c->max_tag) {
 153                 spin_lock_irqsave(&c->lock, flags);
 154                 /* check again since original check was outside of lock */
 155                 while (tag >= c->max_tag) {
 156                         row = (tag / P9_ROW_MAXTAG);
 157                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 158                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 159
 160                         if (!c->reqs[row]) {
 161                                 printk(KERN_ERR "Couldn't grow tag array\n");
 162                                 spin_unlock_irqrestore(&c->lock, flags);
 163                                 return ERR_PTR(-ENOMEM);
 164                         }
 165                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 166                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 167                                 c->reqs[row][col].tc = NULL;
 168                         }
 169                         c->max_tag += P9_ROW_MAXTAG;
 170                 }
 171                 spin_unlock_irqrestore(&c->lock, flags);
 172         }
 173         row = tag / P9_ROW_MAXTAG;
 174         col = tag % P9_ROW_MAXTAG;
 175
 176         req = &c->reqs[row][col];
 177         if (!req->tc) {
 178                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
 179                 if (!req->wq) {
 180                         printk(KERN_ERR "Couldn't grow tag array\n");
 181                         return ERR_PTR(-ENOMEM);
 182                 }
 183                 init_waitqueue_head(req->wq);
 184                 req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 185                                                                 GFP_KERNEL);
 186                 req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 187                                                                 GFP_KERNEL);
 188                 if ((!req->tc) || (!req->rc)) {
 189                         printk(KERN_ERR "Couldn't grow tag array\n");
 190                         kfree(req->tc);
 191                         kfree(req->rc);
 192                         return ERR_PTR(-ENOMEM);
 193                 }
 194                 req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
 195                 req->tc->capacity = c->msize;
 196                 req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
 197                 req->rc->capacity = c->msize;
 198         }
 199
 200         p9pdu_reset(req->tc);
 201         p9pdu_reset(req->rc);
 202
 203         req->flush_tag = 0;
 204         req->tc->tag = tag-1;
 205         req->status = REQ_STATUS_ALLOC;
 206
 207         return &c->reqs[row][col];
 208 }
 209
 210 /**
 211  * p9_tag_lookup - lookup a request by tag
 212  * @c: client session to lookup tag within
 213  * @tag: numeric id for transaction
 214  *
 215  */
 216
 217 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 218 {
 219         int row, col;
 220
 221         /* This looks up the original request by tag so we know which
 222          * buffer to read the data into */
 223         tag++;
 224
 225         BUG_ON(tag >= c->max_tag);
 226
 227         row = tag / P9_ROW_MAXTAG;
 228         col = tag % P9_ROW_MAXTAG;
 229
 230         return &c->reqs[row][col];
 231 }
 232 EXPORT_SYMBOL(p9_tag_lookup);
 233
 234 /**
 235  * p9_tag_init - setup tags structure and contents
 236  * @tags: tags structure from the client struct
 237  *
 238  * This initializes the tags structure for each client instance.
 239  *
 240  */
 241
 242 static int p9_tag_init(struct p9_client *c)
 243 {
 244         int err = 0;
 245
 246         c->tagpool = p9_idpool_create();
 247         if (IS_ERR(c->tagpool)) {
 248                 err = PTR_ERR(c->tagpool);
 249                 c->tagpool = NULL;
 250                 goto error;
 251         }
 252
 253         p9_idpool_get(c->tagpool); /* reserve tag 0 */
 254
 255         c->max_tag = 0;
 256 error:
 257         return err;
 258 }
 259
 260 /**
 261  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 262  * @tags: tags structure from the client struct
 263  *
 264  * This frees resources associated with the tags structure
 265  *
 266  */
 267 static void p9_tag_cleanup(struct p9_client *c)
 268 {
 269         int row, col;
 270
 271         /* check to insure all requests are idle */
 272         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 273                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 274                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 275                                 P9_DPRINTK(P9_DEBUG_MUX,
 276                                   "Attempting to cleanup non-free tag %d,%d\n",
 277                                   row, col);
 278                                 /* TODO: delay execution of cleanup */
 279                                 return;
 280                         }
 281                 }
 282         }
 283
 284         if (c->tagpool)
 285                 p9_idpool_destroy(c->tagpool);
 286
 287         /* free requests associated with tags */
 288         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 289                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 290                         kfree(c->reqs[row][col].wq);
 291                         kfree(c->reqs[row][col].tc);
 292                         kfree(c->reqs[row][col].rc);
 293                 }
 294                 kfree(c->reqs[row]);
 295         }
 296         c->max_tag = 0;
 297 }
 298
 299 /**
 300  * p9_free_req - free a request and clean-up as necessary
 301  * c: client state
 302  * r: request to release
 303  *
 304  */
 305
 306 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 307 {
 308         int tag = r->tc->tag;
 309         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 310
 311         r->status = REQ_STATUS_IDLE;
 312         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 313                 p9_idpool_put(tag, c->tagpool);
 314 }
 315
 316 /**
 317  * p9_client_cb - call back from transport to client
 318  * c: client state
 319  * req: request received
 320  *
 321  */
 322 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
 323 {
 324         struct p9_req_t *other_req;
 325         unsigned long flags;
 326
 327         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 328
 329         if (req->status == REQ_STATUS_ERROR)
 330                 wake_up(req->wq);
 331
 332         if (req->flush_tag) {                   /* flush receive path */
 333                 P9_DPRINTK(P9_DEBUG_9P, "<<< RFLUSH %d\n", req->tc->tag);
 334                 spin_lock_irqsave(&c->lock, flags);
 335                 other_req = p9_tag_lookup(c, req->flush_tag);
 336                 if (other_req->status != REQ_STATUS_FLSH) /* stale flush */
 337                         spin_unlock_irqrestore(&c->lock, flags);
 338                 else {
 339                         other_req->status = REQ_STATUS_FLSHD;
 340                         spin_unlock_irqrestore(&c->lock, flags);
 341                         wake_up(other_req->wq);
 342                 }
 343                 p9_free_req(c, req);
 344         } else {                                /* normal receive path */
 345                 P9_DPRINTK(P9_DEBUG_MUX, "normal: tag %d\n", req->tc->tag);
 346                 spin_lock_irqsave(&c->lock, flags);
 347                 if (req->status != REQ_STATUS_FLSHD)
 348                         req->status = REQ_STATUS_RCVD;
 349                 spin_unlock_irqrestore(&c->lock, flags);
 350                 wake_up(req->wq);
 351                 P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 352         }
 353 }
 354 EXPORT_SYMBOL(p9_client_cb);
 355
 356 /**
 357  * p9_parse_header - parse header arguments out of a packet
 358  * @pdu: packet to parse
 359  * @size: size of packet
 360  * @type: type of request
 361  * @tag: tag of packet
 362  * @rewind: set if we need to rewind offset afterwards
 363  */
 364
 365 int
 366 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 367                                                                 int rewind)
 368 {
 369         int8_t r_type;
 370         int16_t r_tag;
 371         int32_t r_size;
 372         int offset = pdu->offset;
 373         int err;
 374
 375         pdu->offset = 0;
 376         if (pdu->size == 0)
 377                 pdu->size = 7;
 378
 379         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 380         if (err)
 381                 goto rewind_and_exit;
 382
 383         pdu->size = r_size;
 384         pdu->id = r_type;
 385         pdu->tag = r_tag;
 386
 387         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
 388                                                         pdu->id, pdu->tag);
 389
 390         if (type)
 391                 *type = r_type;
 392         if (tag)
 393                 *tag = r_tag;
 394         if (size)
 395                 *size = r_size;
 396
 397
 398 rewind_and_exit:
 399         if (rewind)
 400                 pdu->offset = offset;
 401         return err;
 402 }
 403 EXPORT_SYMBOL(p9_parse_header);
 404
 405 /**
 406  * p9_check_errors - check 9p packet for error return and process it
 407  * @c: current client instance
 408  * @req: request to parse and check for error conditions
 409  *
 410  * returns error code if one is discovered, otherwise returns 0
 411  *
 412  * this will have to be more complicated if we have multiple
 413  * error packet types
 414  */
 415
 416 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 417 {
 418         int8_t type;
 419         int err;
 420
 421         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 422         if (err) {
 423                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 424                 return err;
 425         }
 426
 427         if (type == P9_RERROR) {
 428                 int ecode;
 429                 char *ename;
 430
 431                 err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
 432                 if (err) {
 433                         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
 434                                                                         err);
 435                         return err;
 436                 }
 437
 438                 if (c->dotu)
 439                         err = -ecode;
 440
 441                 if (!err) {
 442                         err = p9_errstr2errno(ename, strlen(ename));
 443
 444                         /* string match failed */
 445                         if (!err)
 446                                 err = -ESERVERFAULT;
 447                 }
 448
 449                 P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
 450
 451                 kfree(ename);
 452         } else
 453                 err = 0;
 454
 455         return err;
 456 }
 457
 458 /**
 459  * p9_client_flush - flush (cancel) a request
 460  * c: client state
 461  * req: request to cancel
 462  *
 463  * This sents a flush for a particular requests and links
 464  * the flush request to the original request.  The current
 465  * code only supports a single flush request although the protocol
 466  * allows for multiple flush requests to be sent for a single request.
 467  *
 468  */
 469
 470 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 471 {
 472         struct p9_req_t *req;
 473         int16_t oldtag;
 474         int err;
 475
 476         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 477         if (err)
 478                 return err;
 479
 480         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 481
 482         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 483         if (IS_ERR(req))
 484                 return PTR_ERR(req);
 485
 486         req->flush_tag = oldtag;
 487
 488         /* we don't free anything here because RPC isn't complete */
 489         return 0;
 490 }
 491
 492 /**
 493  * p9_client_rpc - issue a request and wait for a response
 494  * @c: client session
 495  * @type: type of request
 496  * @fmt: protocol format string (see protocol.c)
 497  *
 498  * Returns request structure (which client must free using p9_free_req)
 499  */
 500
 501 static struct p9_req_t *
 502 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 503 {
 504         va_list ap;
 505         int tag, err;
 506         struct p9_req_t *req;
 507         unsigned long flags;
 508         int sigpending;
 509         int flushed = 0;
 510
 511         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 512
 513         if (c->status != Connected)
 514                 return ERR_PTR(-EIO);
 515
 516         if (signal_pending(current)) {
 517                 sigpending = 1;
 518                 clear_thread_flag(TIF_SIGPENDING);
 519         } else
 520                 sigpending = 0;
 521
 522         tag = P9_NOTAG;
 523         if (type != P9_TVERSION) {
 524                 tag = p9_idpool_get(c->tagpool);
 525                 if (tag < 0)
 526                         return ERR_PTR(-ENOMEM);
 527         }
 528
 529         req = p9_tag_alloc(c, tag);
 530         if (IS_ERR(req))
 531                 return req;
 532
 533         /* marshall the data */
 534         p9pdu_prepare(req->tc, tag, type);
 535         va_start(ap, fmt);
 536         err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
 537         va_end(ap);
 538         p9pdu_finalize(req->tc);
 539
 540         err = c->trans_mod->request(c, req);
 541         if (err < 0) {
 542                 c->status = Disconnected;
 543                 goto reterr;
 544         }
 545
 546         /* if it was a flush we just transmitted, return our tag */
 547         if (type == P9_TFLUSH)
 548                 return req;
 549 again:
 550         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
 551         err = wait_event_interruptible(*req->wq,
 552                                                 req->status >= REQ_STATUS_RCVD);
 553         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d (flushed=%d)\n",
 554                                                 req->wq, tag, err, flushed);
 555
 556         if (req->status == REQ_STATUS_ERROR) {
 557                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 558                 err = req->t_err;
 559         } else if (err == -ERESTARTSYS && flushed) {
 560                 P9_DPRINTK(P9_DEBUG_MUX, "flushed - going again\n");
 561                 goto again;
 562         } else if (req->status == REQ_STATUS_FLSHD) {
 563                 P9_DPRINTK(P9_DEBUG_MUX, "flushed - erestartsys\n");
 564                 err = -ERESTARTSYS;
 565         }
 566
 567         if ((err == -ERESTARTSYS) && (c->status == Connected) && (!flushed)) {
 568                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
 569                 spin_lock_irqsave(&c->lock, flags);
 570                 if (req->status == REQ_STATUS_SENT)
 571                         req->status = REQ_STATUS_FLSH;
 572                 spin_unlock_irqrestore(&c->lock, flags);
 573                 sigpending = 1;
 574                 flushed = 1;
 575                 clear_thread_flag(TIF_SIGPENDING);
 576
 577                 if (c->trans_mod->cancel(c, req)) {
 578                         err = p9_client_flush(c, req);
 579                         if (err == 0)
 580                                 goto again;
 581                 }
 582         }
 583
 584         if (sigpending) {
 585                 spin_lock_irqsave(&current->sighand->siglock, flags);
 586                 recalc_sigpending();
 587                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 588         }
 589
 590         if (err < 0)
 591                 goto reterr;
 592
 593         err = p9_check_errors(c, req);
 594         if (!err) {
 595                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
 596                 return req;
 597         }
 598
 599 reterr:
 600         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
 601                                                                         err);
 602         p9_free_req(c, req);
 603         return ERR_PTR(err);
 604 }
 605
 606 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 607 {
 608         int err;
 609         struct p9_fid *fid;
 610         unsigned long flags;
 611
 612         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
 613         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 614         if (!fid)
 615                 return ERR_PTR(-ENOMEM);
 616
 617         fid->fid = p9_idpool_get(clnt->fidpool);
 618         if (fid->fid < 0) {
 619                 err = -ENOSPC;
 620                 goto error;
 621         }
 622
 623         memset(&fid->qid, 0, sizeof(struct p9_qid));
 624         fid->mode = -1;
 625         fid->rdir_fpos = 0;
 626         fid->uid = current->fsuid;
 627         fid->clnt = clnt;
 628         fid->aux = NULL;
 629
 630         spin_lock_irqsave(&clnt->lock, flags);
 631         list_add(&fid->flist, &clnt->fidlist);
 632         spin_unlock_irqrestore(&clnt->lock, flags);
 633
 634         return fid;
 635
 636 error:
 637         kfree(fid);
 638         return ERR_PTR(err);
 639 }
 640
 641 static void p9_fid_destroy(struct p9_fid *fid)
 642 {
 643         struct p9_client *clnt;
 644         unsigned long flags;
 645
 646         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
 647         clnt = fid->clnt;
 648         p9_idpool_put(fid->fid, clnt->fidpool);
 649         spin_lock_irqsave(&clnt->lock, flags);
 650         list_del(&fid->flist);
 651         spin_unlock_irqrestore(&clnt->lock, flags);
 652         kfree(fid);
 653 }
 654
 655 int p9_client_version(struct p9_client *c)
 656 {
 657         int err = 0;
 658         struct p9_req_t *req;
 659         char *version;
 660         int msize;
 661
 662         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
 663                                                         c->msize, c->dotu);
 664         req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
 665                                 c->dotu ? "9P2000.u" : "9P2000");
 666         if (IS_ERR(req))
 667                 return PTR_ERR(req);
 668
 669         err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
 670         if (err) {
 671                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
 672                 p9pdu_dump(1, req->rc);
 673                 goto error;
 674         }
 675
 676         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 677         if (!memcmp(version, "9P2000.u", 8))
 678                 c->dotu = 1;
 679         else if (!memcmp(version, "9P2000", 6))
 680                 c->dotu = 0;
 681         else {
 682                 err = -EREMOTEIO;
 683                 goto error;
 684         }
 685
 686         if (msize < c->msize)
 687                 c->msize = msize;
 688
 689 error:
 690         kfree(version);
 691         p9_free_req(c, req);
 692
 693         return err;
 694 }
 695 EXPORT_SYMBOL(p9_client_version);
 696
 697 struct p9_client *p9_client_create(const char *dev_name, char *options)
 698 {
 699         int err;
 700         struct p9_client *clnt;
 701
 702         err = 0;
 703         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 704         if (!clnt)
 705                 return ERR_PTR(-ENOMEM);
 706
 707         clnt->trans_mod = NULL;
 708         clnt->trans = NULL;
 709         spin_lock_init(&clnt->lock);
 710         INIT_LIST_HEAD(&clnt->fidlist);
 711         clnt->fidpool = p9_idpool_create();
 712         if (IS_ERR(clnt->fidpool)) {
 713                 err = PTR_ERR(clnt->fidpool);
 714                 clnt->fidpool = NULL;
 715                 goto error;
 716         }
 717
 718         p9_tag_init(clnt);
 719
 720         err = parse_opts(options, clnt);
 721         if (err < 0)
 722                 goto error;
 723
 724         if (clnt->trans_mod == NULL) {
 725                 err = -EPROTONOSUPPORT;
 726                 P9_DPRINTK(P9_DEBUG_ERROR,
 727                                 "No transport defined or default transport\n");
 728                 goto error;
 729         }
 730
 731         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
 732                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 733
 734         err = clnt->trans_mod->create(clnt, dev_name, options);
 735         if (err)
 736                 goto error;
 737
 738         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 739                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 740
 741         err = p9_client_version(clnt);
 742         if (err)
 743                 goto error;
 744
 745         return clnt;
 746
 747 error:
 748         p9_client_destroy(clnt);
 749         return ERR_PTR(err);
 750 }
 751 EXPORT_SYMBOL(p9_client_create);
 752
 753 void p9_client_destroy(struct p9_client *clnt)
 754 {
 755         struct p9_fid *fid, *fidptr;
 756
 757         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
 758
 759         if (clnt->trans_mod)
 760                 clnt->trans_mod->close(clnt);
 761
 762         v9fs_put_trans(clnt->trans_mod);
 763
 764         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 765                 p9_fid_destroy(fid);
 766
 767         if (clnt->fidpool)
 768                 p9_idpool_destroy(clnt->fidpool);
 769
 770         p9_tag_cleanup(clnt);
 771
 772         kfree(clnt);
 773 }
 774 EXPORT_SYMBOL(p9_client_destroy);
 775
 776 void p9_client_disconnect(struct p9_client *clnt)
 777 {
 778         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 779         clnt->status = Disconnected;
 780 }
 781 EXPORT_SYMBOL(p9_client_disconnect);
 782
 783 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 784         char *uname, u32 n_uname, char *aname)
 785 {
 786         int err;
 787         struct p9_req_t *req;
 788         struct p9_fid *fid;
 789         struct p9_qid qid;
 790
 791         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
 792                                         afid ? afid->fid : -1, uname, aname);
 793         err = 0;
 794
 795         fid = p9_fid_create(clnt);
 796         if (IS_ERR(fid)) {
 797                 err = PTR_ERR(fid);
 798                 fid = NULL;
 799                 goto error;
 800         }
 801
 802         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
 803                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 804         if (IS_ERR(req)) {
 805                 err = PTR_ERR(req);
 806                 goto error;
 807         }
 808
 809         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 810         if (err) {
 811                 p9pdu_dump(1, req->rc);
 812                 p9_free_req(clnt, req);
 813                 goto error;
 814         }
 815
 816         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
 817                                         qid.type, qid.path, qid.version);
 818
 819         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
 820
 821         p9_free_req(clnt, req);
 822         return fid;
 823
 824 error:
 825         if (fid)
 826                 p9_fid_destroy(fid);
 827         return ERR_PTR(err);
 828 }
 829 EXPORT_SYMBOL(p9_client_attach);
 830
 831 struct p9_fid *
 832 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
 833 {
 834         int err;
 835         struct p9_req_t *req;
 836         struct p9_qid qid;
 837         struct p9_fid *afid;
 838
 839         P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
 840         err = 0;
 841
 842         afid = p9_fid_create(clnt);
 843         if (IS_ERR(afid)) {
 844                 err = PTR_ERR(afid);
 845                 afid = NULL;
 846                 goto error;
 847         }
 848
 849         req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
 850                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 851         if (IS_ERR(req)) {
 852                 err = PTR_ERR(req);
 853                 goto error;
 854         }
 855
 856         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 857         if (err) {
 858                 p9pdu_dump(1, req->rc);
 859                 p9_free_req(clnt, req);
 860                 goto error;
 861         }
 862
 863         P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
 864                                         qid.type, qid.path, qid.version);
 865
 866         memmove(&afid->qid, &qid, sizeof(struct p9_qid));
 867         p9_free_req(clnt, req);
 868         return afid;
 869
 870 error:
 871         if (afid)
 872                 p9_fid_destroy(afid);
 873         return ERR_PTR(err);
 874 }
 875 EXPORT_SYMBOL(p9_client_auth);
 876
 877 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 878         int clone)
 879 {
 880         int err;
 881         struct p9_client *clnt;
 882         struct p9_fid *fid;
 883         struct p9_qid *wqids;
 884         struct p9_req_t *req;
 885         int16_t nwqids, count;
 886
 887         err = 0;
 888         clnt = oldfid->clnt;
 889         if (clone) {
 890                 fid = p9_fid_create(clnt);
 891                 if (IS_ERR(fid)) {
 892                         err = PTR_ERR(fid);
 893                         fid = NULL;
 894                         goto error;
 895                 }
 896
 897                 fid->uid = oldfid->uid;
 898         } else
 899                 fid = oldfid;
 900
 901
 902         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
 903                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
 904
 905         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
 906                                                                 nwname, wnames);
 907         if (IS_ERR(req)) {
 908                 err = PTR_ERR(req);
 909                 goto error;
 910         }
 911
 912         err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
 913         if (err) {
 914                 p9pdu_dump(1, req->rc);
 915                 p9_free_req(clnt, req);
 916                 goto clunk_fid;
 917         }
 918         p9_free_req(clnt, req);
 919
 920         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
 921
 922         if (nwqids != nwname) {
 923                 err = -ENOENT;
 924                 goto clunk_fid;
 925         }
 926
 927         for (count = 0; count < nwqids; count++)
 928                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
 929                         count, wqids[count].type, wqids[count].path,
 930                         wqids[count].version);
 931
 932         if (nwname)
 933                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
 934         else
 935                 fid->qid = oldfid->qid;
 936
 937         return fid;
 938
 939 clunk_fid:
 940         p9_client_clunk(fid);
 941         fid = NULL;
 942
 943 error:
 944         if (fid && (fid != oldfid))
 945                 p9_fid_destroy(fid);
 946
 947         return ERR_PTR(err);
 948 }
 949 EXPORT_SYMBOL(p9_client_walk);
 950
 951 int p9_client_open(struct p9_fid *fid, int mode)
 952 {
 953         int err;
 954         struct p9_client *clnt;
 955         struct p9_req_t *req;
 956         struct p9_qid qid;
 957         int iounit;
 958
 959         P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
 960         err = 0;
 961         clnt = fid->clnt;
 962
 963         if (fid->mode != -1)
 964                 return -EINVAL;
 965
 966         req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
 967         if (IS_ERR(req)) {
 968                 err = PTR_ERR(req);
 969                 goto error;
 970         }
 971
 972         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 973         if (err) {
 974                 p9pdu_dump(1, req->rc);
 975                 goto free_and_error;
 976         }
 977
 978         P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
 979                                 qid.type, qid.path, qid.version, iounit);
 980
 981         fid->mode = mode;
 982         fid->iounit = iounit;
 983
 984 free_and_error:
 985         p9_free_req(clnt, req);
 986 error:
 987         return err;
 988 }
 989 EXPORT_SYMBOL(p9_client_open);
 990
 991 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 992                      char *extension)
 993 {
 994         int err;
 995         struct p9_client *clnt;
 996         struct p9_req_t *req;
 997         struct p9_qid qid;
 998         int iounit;
 999
1000         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1001                                                 fid->fid, name, perm, mode);
1002         err = 0;
1003         clnt = fid->clnt;
1004
1005         if (fid->mode != -1)
1006                 return -EINVAL;
1007
1008         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1009                                 mode, extension);
1010         if (IS_ERR(req)) {
1011                 err = PTR_ERR(req);
1012                 goto error;
1013         }
1014
1015         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
1016         if (err) {
1017                 p9pdu_dump(1, req->rc);
1018                 goto free_and_error;
1019         }
1020
1021         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1022                                 qid.type, qid.path, qid.version, iounit);
1023
1024         fid->mode = mode;
1025         fid->iounit = iounit;
1026
1027 free_and_error:
1028         p9_free_req(clnt, req);
1029 error:
1030         return err;
1031 }
1032 EXPORT_SYMBOL(p9_client_fcreate);
1033
1034 int p9_client_clunk(struct p9_fid *fid)
1035 {
1036         int err;
1037         struct p9_client *clnt;
1038         struct p9_req_t *req;
1039
1040         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1041         err = 0;
1042         clnt = fid->clnt;
1043
1044         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1045         if (IS_ERR(req)) {
1046                 err = PTR_ERR(req);
1047                 goto error;
1048         }
1049
1050         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1051
1052         p9_free_req(clnt, req);
1053         p9_fid_destroy(fid);
1054
1055 error:
1056         return err;
1057 }
1058 EXPORT_SYMBOL(p9_client_clunk);
1059
1060 int p9_client_remove(struct p9_fid *fid)
1061 {
1062         int err;
1063         struct p9_client *clnt;
1064         struct p9_req_t *req;
1065
1066         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1067         err = 0;
1068         clnt = fid->clnt;
1069
1070         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1071         if (IS_ERR(req)) {
1072                 err = PTR_ERR(req);
1073                 goto error;
1074         }
1075
1076         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1077
1078         p9_free_req(clnt, req);
1079         p9_fid_destroy(fid);
1080
1081 error:
1082         return err;
1083 }
1084 EXPORT_SYMBOL(p9_client_remove);
1085
1086 int
1087 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1088                                                                 u32 count)
1089 {
1090         int err, rsize, total;
1091         struct p9_client *clnt;
1092         struct p9_req_t *req;
1093         char *dataptr;
1094
1095         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1096                                         (long long unsigned) offset, count);
1097         err = 0;
1098         clnt = fid->clnt;
1099         total = 0;
1100
1101         rsize = fid->iounit;
1102         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1103                 rsize = clnt->msize - P9_IOHDRSZ;
1104
1105         if (count < rsize)
1106                 rsize = count;
1107
1108         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1109         if (IS_ERR(req)) {
1110                 err = PTR_ERR(req);
1111                 goto error;
1112         }
1113
1114         err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1115         if (err) {
1116                 p9pdu_dump(1, req->rc);
1117                 goto free_and_error;
1118         }
1119
1120         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1121
1122         if (data) {
1123                 memmove(data, dataptr, count);
1124                 data += count;
1125         }
1126
1127         if (udata) {
1128                 err = copy_to_user(udata, dataptr, count);
1129                 if (err) {
1130                         err = -EFAULT;
1131                         goto free_and_error;
1132                 }
1133         }
1134
1135         p9_free_req(clnt, req);
1136         return count;
1137
1138 free_and_error:
1139         p9_free_req(clnt, req);
1140 error:
1141         return err;
1142 }
1143 EXPORT_SYMBOL(p9_client_read);
1144
1145 int
1146 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1147                                                         u64 offset, u32 count)
1148 {
1149         int err, rsize, total;
1150         struct p9_client *clnt;
1151         struct p9_req_t *req;
1152
1153         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1154                                 fid->fid, (long long unsigned) offset, count);
1155         err = 0;
1156         clnt = fid->clnt;
1157         total = 0;
1158
1159         rsize = fid->iounit;
1160         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1161                 rsize = clnt->msize - P9_IOHDRSZ;
1162
1163         if (count < rsize)
1164                 rsize = count;
1165         if (data)
1166                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1167                                                                 rsize, data);
1168         else
1169                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1170                                                                 rsize, udata);
1171         if (IS_ERR(req)) {
1172                 err = PTR_ERR(req);
1173                 goto error;
1174         }
1175
1176         err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1177         if (err) {
1178                 p9pdu_dump(1, req->rc);
1179                 goto free_and_error;
1180         }
1181
1182         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1183
1184         p9_free_req(clnt, req);
1185         return count;
1186
1187 free_and_error:
1188         p9_free_req(clnt, req);
1189 error:
1190         return err;
1191 }
1192 EXPORT_SYMBOL(p9_client_write);
1193
1194 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1195 {
1196         int err;
1197         struct p9_client *clnt;
1198         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1199         struct p9_req_t *req;
1200         u16 ignored;
1201
1202         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1203
1204         if (!ret)
1205                 return ERR_PTR(-ENOMEM);
1206
1207         err = 0;
1208         clnt = fid->clnt;
1209
1210         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1211         if (IS_ERR(req)) {
1212                 err = PTR_ERR(req);
1213                 goto error;
1214         }
1215
1216         err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1217         if (err) {
1218                 ret = ERR_PTR(err);
1219                 p9pdu_dump(1, req->rc);
1220                 goto free_and_error;
1221         }
1222
1223         P9_DPRINTK(P9_DEBUG_9P,
1224                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1225                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1226                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1227                 "<<<    uid=%d gid=%d n_muid=%d\n",
1228                 ret->size, ret->type, ret->dev, ret->qid.type,
1229                 ret->qid.path, ret->qid.version, ret->mode,
1230                 ret->atime, ret->mtime, ret->length, ret->name,
1231                 ret->uid, ret->gid, ret->muid, ret->extension,
1232                 ret->n_uid, ret->n_gid, ret->n_muid);
1233
1234 free_and_error:
1235         p9_free_req(clnt, req);
1236 error:
1237         return ret;
1238 }
1239 EXPORT_SYMBOL(p9_client_stat);
1240
1241 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1242 {
1243         int err;
1244         struct p9_req_t *req;
1245         struct p9_client *clnt;
1246
1247         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1248         P9_DPRINTK(P9_DEBUG_9P,
1249                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1250                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1251                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1252                 "     uid=%d gid=%d n_muid=%d\n",
1253                 wst->size, wst->type, wst->dev, wst->qid.type,
1254                 wst->qid.path, wst->qid.version, wst->mode,
1255                 wst->atime, wst->mtime, wst->length, wst->name,
1256                 wst->uid, wst->gid, wst->muid, wst->extension,
1257                 wst->n_uid, wst->n_gid, wst->n_muid);
1258         err = 0;
1259         clnt = fid->clnt;
1260
1261         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, 0, wst);
1262         if (IS_ERR(req)) {
1263                 err = PTR_ERR(req);
1264                 goto error;
1265         }
1266
1267         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1268
1269         p9_free_req(clnt, req);
1270 error:
1271         return err;
1272 }
1273 EXPORT_SYMBOL(p9_client_wstat);