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_version,
  50         Opt_err,
  51 };
  52
  53 static const match_table_t tokens = {
  54         {Opt_msize, "msize=%u"},
  55         {Opt_legacy, "noextend"},
  56         {Opt_trans, "trans=%s"},
  57         {Opt_version, "version=%s"},
  58         {Opt_err, NULL},
  59 };
  60
  61 inline int p9_is_proto_dotl(struct p9_client *clnt)
  62 {
  63         return (clnt->proto_version == p9_proto_2010L);
  64 }
  65 EXPORT_SYMBOL(p9_is_proto_dotl);
  66
  67 inline int p9_is_proto_dotu(struct p9_client *clnt)
  68 {
  69         return (clnt->proto_version == p9_proto_2000u);
  70 }
  71 EXPORT_SYMBOL(p9_is_proto_dotu);
  72
  73 /* Interpret mount option for protocol version */
  74 static unsigned char get_protocol_version(const substring_t *name)
  75 {
  76         unsigned char version = -EINVAL;
  77         if (!strncmp("9p2000", name->from, name->to-name->from)) {
  78                 version = p9_proto_legacy;
  79                 P9_DPRINTK(P9_DEBUG_9P, "Protocol version: Legacy\n");
  80         } else if (!strncmp("9p2000.u", name->from, name->to-name->from)) {
  81                 version = p9_proto_2000u;
  82                 P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
  83         } else if (!strncmp("9p2010.L", name->from, name->to-name->from)) {
  84                 version = p9_proto_2010L;
  85                 P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2010.L\n");
  86         } else {
  87                 P9_DPRINTK(P9_DEBUG_ERROR, "Unknown protocol version %s. ",
  88                                                         name->from);
  89         }
  90         return version;
  91 }
  92
  93 static struct p9_req_t *
  94 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
  95
  96 /**
  97  * parse_options - parse mount options into client structure
  98  * @opts: options string passed from mount
  99  * @clnt: existing v9fs client information
 100  *
 101  * Return 0 upon success, -ERRNO upon failure
 102  */
 103
 104 static int parse_opts(char *opts, struct p9_client *clnt)
 105 {
 106         char *options, *tmp_options;
 107         char *p;
 108         substring_t args[MAX_OPT_ARGS];
 109         int option;
 110         int ret = 0;
 111
 112         clnt->proto_version = p9_proto_2000u;
 113         clnt->msize = 8192;
 114
 115         if (!opts)
 116                 return 0;
 117
 118         tmp_options = kstrdup(opts, GFP_KERNEL);
 119         if (!tmp_options) {
 120                 P9_DPRINTK(P9_DEBUG_ERROR,
 121                                 "failed to allocate copy of option string\n");
 122                 return -ENOMEM;
 123         }
 124         options = tmp_options;
 125
 126         while ((p = strsep(&options, ",")) != NULL) {
 127                 int token;
 128                 if (!*p)
 129                         continue;
 130                 token = match_token(p, tokens, args);
 131                 if (token < Opt_trans) {
 132                         int r = match_int(&args[0], &option);
 133                         if (r < 0) {
 134                                 P9_DPRINTK(P9_DEBUG_ERROR,
 135                                         "integer field, but no integer?\n");
 136                                 ret = r;
 137                                 continue;
 138                         }
 139                 }
 140                 switch (token) {
 141                 case Opt_msize:
 142                         clnt->msize = option;
 143                         break;
 144                 case Opt_trans:
 145                         clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
 146                         if(clnt->trans_mod == NULL) {
 147                                 P9_DPRINTK(P9_DEBUG_ERROR,
 148                                    "Could not find request transport: %s\n",
 149                                    (char *) &args[0]);
 150                                 ret = -EINVAL;
 151                                 goto free_and_return;
 152                         }
 153                         break;
 154                 case Opt_legacy:
 155                         clnt->proto_version = p9_proto_legacy;
 156                         break;
 157                 case Opt_version:
 158                         ret = get_protocol_version(&args[0]);
 159                         if (ret == -EINVAL)
 160                                 goto free_and_return;
 161                         clnt->proto_version = ret;
 162                         break;
 163                 default:
 164                         continue;
 165                 }
 166         }
 167
 168 free_and_return:
 169         kfree(tmp_options);
 170         return ret;
 171 }
 172
 173 /**
 174  * p9_tag_alloc - lookup/allocate a request by tag
 175  * @c: client session to lookup tag within
 176  * @tag: numeric id for transaction
 177  *
 178  * this is a simple array lookup, but will grow the
 179  * request_slots as necessary to accomodate transaction
 180  * ids which did not previously have a slot.
 181  *
 182  * this code relies on the client spinlock to manage locks, its
 183  * possible we should switch to something else, but I'd rather
 184  * stick with something low-overhead for the common case.
 185  *
 186  */
 187
 188 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
 189 {
 190         unsigned long flags;
 191         int row, col;
 192         struct p9_req_t *req;
 193
 194         /* This looks up the original request by tag so we know which
 195          * buffer to read the data into */
 196         tag++;
 197
 198         if (tag >= c->max_tag) {
 199                 spin_lock_irqsave(&c->lock, flags);
 200                 /* check again since original check was outside of lock */
 201                 while (tag >= c->max_tag) {
 202                         row = (tag / P9_ROW_MAXTAG);
 203                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 204                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 205
 206                         if (!c->reqs[row]) {
 207                                 printk(KERN_ERR "Couldn't grow tag array\n");
 208                                 spin_unlock_irqrestore(&c->lock, flags);
 209                                 return ERR_PTR(-ENOMEM);
 210                         }
 211                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 212                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 213                                 c->reqs[row][col].tc = NULL;
 214                         }
 215                         c->max_tag += P9_ROW_MAXTAG;
 216                 }
 217                 spin_unlock_irqrestore(&c->lock, flags);
 218         }
 219         row = tag / P9_ROW_MAXTAG;
 220         col = tag % P9_ROW_MAXTAG;
 221
 222         req = &c->reqs[row][col];
 223         if (!req->tc) {
 224                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
 225                 if (!req->wq) {
 226                         printk(KERN_ERR "Couldn't grow tag array\n");
 227                         return ERR_PTR(-ENOMEM);
 228                 }
 229                 init_waitqueue_head(req->wq);
 230                 req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 231                                                                 GFP_KERNEL);
 232                 req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 233                                                                 GFP_KERNEL);
 234                 if ((!req->tc) || (!req->rc)) {
 235                         printk(KERN_ERR "Couldn't grow tag array\n");
 236                         kfree(req->tc);
 237                         kfree(req->rc);
 238                         kfree(req->wq);
 239                         req->tc = req->rc = NULL;
 240                         req->wq = NULL;
 241                         return ERR_PTR(-ENOMEM);
 242                 }
 243                 req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
 244                 req->tc->capacity = c->msize;
 245                 req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
 246                 req->rc->capacity = c->msize;
 247         }
 248
 249         p9pdu_reset(req->tc);
 250         p9pdu_reset(req->rc);
 251
 252         req->tc->tag = tag-1;
 253         req->status = REQ_STATUS_ALLOC;
 254
 255         return &c->reqs[row][col];
 256 }
 257
 258 /**
 259  * p9_tag_lookup - lookup a request by tag
 260  * @c: client session to lookup tag within
 261  * @tag: numeric id for transaction
 262  *
 263  */
 264
 265 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 266 {
 267         int row, col;
 268
 269         /* This looks up the original request by tag so we know which
 270          * buffer to read the data into */
 271         tag++;
 272
 273         BUG_ON(tag >= c->max_tag);
 274
 275         row = tag / P9_ROW_MAXTAG;
 276         col = tag % P9_ROW_MAXTAG;
 277
 278         return &c->reqs[row][col];
 279 }
 280 EXPORT_SYMBOL(p9_tag_lookup);
 281
 282 /**
 283  * p9_tag_init - setup tags structure and contents
 284  * @c:  v9fs client struct
 285  *
 286  * This initializes the tags structure for each client instance.
 287  *
 288  */
 289
 290 static int p9_tag_init(struct p9_client *c)
 291 {
 292         int err = 0;
 293
 294         c->tagpool = p9_idpool_create();
 295         if (IS_ERR(c->tagpool)) {
 296                 err = PTR_ERR(c->tagpool);
 297                 c->tagpool = NULL;
 298                 goto error;
 299         }
 300
 301         p9_idpool_get(c->tagpool); /* reserve tag 0 */
 302
 303         c->max_tag = 0;
 304 error:
 305         return err;
 306 }
 307
 308 /**
 309  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 310  * @c:  v9fs client struct
 311  *
 312  * This frees resources associated with the tags structure
 313  *
 314  */
 315 static void p9_tag_cleanup(struct p9_client *c)
 316 {
 317         int row, col;
 318
 319         /* check to insure all requests are idle */
 320         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 321                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 322                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 323                                 P9_DPRINTK(P9_DEBUG_MUX,
 324                                   "Attempting to cleanup non-free tag %d,%d\n",
 325                                   row, col);
 326                                 /* TODO: delay execution of cleanup */
 327                                 return;
 328                         }
 329                 }
 330         }
 331
 332         if (c->tagpool)
 333                 p9_idpool_destroy(c->tagpool);
 334
 335         /* free requests associated with tags */
 336         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 337                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 338                         kfree(c->reqs[row][col].wq);
 339                         kfree(c->reqs[row][col].tc);
 340                         kfree(c->reqs[row][col].rc);
 341                 }
 342                 kfree(c->reqs[row]);
 343         }
 344         c->max_tag = 0;
 345 }
 346
 347 /**
 348  * p9_free_req - free a request and clean-up as necessary
 349  * c: client state
 350  * r: request to release
 351  *
 352  */
 353
 354 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 355 {
 356         int tag = r->tc->tag;
 357         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 358
 359         r->status = REQ_STATUS_IDLE;
 360         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 361                 p9_idpool_put(tag, c->tagpool);
 362 }
 363
 364 /**
 365  * p9_client_cb - call back from transport to client
 366  * c: client state
 367  * req: request received
 368  *
 369  */
 370 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
 371 {
 372         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 373         wake_up(req->wq);
 374         P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 375 }
 376 EXPORT_SYMBOL(p9_client_cb);
 377
 378 /**
 379  * p9_parse_header - parse header arguments out of a packet
 380  * @pdu: packet to parse
 381  * @size: size of packet
 382  * @type: type of request
 383  * @tag: tag of packet
 384  * @rewind: set if we need to rewind offset afterwards
 385  */
 386
 387 int
 388 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 389                                                                 int rewind)
 390 {
 391         int8_t r_type;
 392         int16_t r_tag;
 393         int32_t r_size;
 394         int offset = pdu->offset;
 395         int err;
 396
 397         pdu->offset = 0;
 398         if (pdu->size == 0)
 399                 pdu->size = 7;
 400
 401         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 402         if (err)
 403                 goto rewind_and_exit;
 404
 405         pdu->size = r_size;
 406         pdu->id = r_type;
 407         pdu->tag = r_tag;
 408
 409         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
 410                                                         pdu->id, pdu->tag);
 411
 412         if (type)
 413                 *type = r_type;
 414         if (tag)
 415                 *tag = r_tag;
 416         if (size)
 417                 *size = r_size;
 418
 419
 420 rewind_and_exit:
 421         if (rewind)
 422                 pdu->offset = offset;
 423         return err;
 424 }
 425 EXPORT_SYMBOL(p9_parse_header);
 426
 427 /**
 428  * p9_check_errors - check 9p packet for error return and process it
 429  * @c: current client instance
 430  * @req: request to parse and check for error conditions
 431  *
 432  * returns error code if one is discovered, otherwise returns 0
 433  *
 434  * this will have to be more complicated if we have multiple
 435  * error packet types
 436  */
 437
 438 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 439 {
 440         int8_t type;
 441         int err;
 442
 443         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 444         if (err) {
 445                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 446                 return err;
 447         }
 448
 449         if (type == P9_RERROR) {
 450                 int ecode;
 451                 char *ename;
 452
 453                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 454                                                         &ename, &ecode);
 455                 if (err) {
 456                         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
 457                                                                         err);
 458                         return err;
 459                 }
 460
 461                 if (p9_is_proto_dotu(c))
 462                         err = -ecode;
 463
 464                 if (!err || !IS_ERR_VALUE(err))
 465                         err = p9_errstr2errno(ename, strlen(ename));
 466
 467                 P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
 468
 469                 kfree(ename);
 470         } else
 471                 err = 0;
 472
 473         return err;
 474 }
 475
 476 /**
 477  * p9_client_flush - flush (cancel) a request
 478  * @c: client state
 479  * @oldreq: request to cancel
 480  *
 481  * This sents a flush for a particular requests and links
 482  * the flush request to the original request.  The current
 483  * code only supports a single flush request although the protocol
 484  * allows for multiple flush requests to be sent for a single request.
 485  *
 486  */
 487
 488 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 489 {
 490         struct p9_req_t *req;
 491         int16_t oldtag;
 492         int err;
 493
 494         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 495         if (err)
 496                 return err;
 497
 498         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 499
 500         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 501         if (IS_ERR(req))
 502                 return PTR_ERR(req);
 503
 504
 505         /* if we haven't received a response for oldreq,
 506            remove it from the list. */
 507         spin_lock(&c->lock);
 508         if (oldreq->status == REQ_STATUS_FLSH)
 509                 list_del(&oldreq->req_list);
 510         spin_unlock(&c->lock);
 511
 512         p9_free_req(c, req);
 513         return 0;
 514 }
 515
 516 /**
 517  * p9_client_rpc - issue a request and wait for a response
 518  * @c: client session
 519  * @type: type of request
 520  * @fmt: protocol format string (see protocol.c)
 521  *
 522  * Returns request structure (which client must free using p9_free_req)
 523  */
 524
 525 static struct p9_req_t *
 526 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 527 {
 528         va_list ap;
 529         int tag, err;
 530         struct p9_req_t *req;
 531         unsigned long flags;
 532         int sigpending;
 533
 534         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 535
 536         if (c->status != Connected)
 537                 return ERR_PTR(-EIO);
 538
 539         if (signal_pending(current)) {
 540                 sigpending = 1;
 541                 clear_thread_flag(TIF_SIGPENDING);
 542         } else
 543                 sigpending = 0;
 544
 545         tag = P9_NOTAG;
 546         if (type != P9_TVERSION) {
 547                 tag = p9_idpool_get(c->tagpool);
 548                 if (tag < 0)
 549                         return ERR_PTR(-ENOMEM);
 550         }
 551
 552         req = p9_tag_alloc(c, tag);
 553         if (IS_ERR(req))
 554                 return req;
 555
 556         /* marshall the data */
 557         p9pdu_prepare(req->tc, tag, type);
 558         va_start(ap, fmt);
 559         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 560         va_end(ap);
 561         p9pdu_finalize(req->tc);
 562
 563         err = c->trans_mod->request(c, req);
 564         if (err < 0) {
 565                 c->status = Disconnected;
 566                 goto reterr;
 567         }
 568
 569         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
 570         err = wait_event_interruptible(*req->wq,
 571                                                 req->status >= REQ_STATUS_RCVD);
 572         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
 573                                                 req->wq, tag, err);
 574
 575         if (req->status == REQ_STATUS_ERROR) {
 576                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 577                 err = req->t_err;
 578         }
 579
 580         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 581                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
 582                 sigpending = 1;
 583                 clear_thread_flag(TIF_SIGPENDING);
 584
 585                 if (c->trans_mod->cancel(c, req))
 586                         p9_client_flush(c, req);
 587
 588                 /* if we received the response anyway, don't signal error */
 589                 if (req->status == REQ_STATUS_RCVD)
 590                         err = 0;
 591         }
 592
 593         if (sigpending) {
 594                 spin_lock_irqsave(&current->sighand->siglock, flags);
 595                 recalc_sigpending();
 596                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 597         }
 598
 599         if (err < 0)
 600                 goto reterr;
 601
 602         err = p9_check_errors(c, req);
 603         if (!err) {
 604                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
 605                 return req;
 606         }
 607
 608 reterr:
 609         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
 610                                                                         err);
 611         p9_free_req(c, req);
 612         return ERR_PTR(err);
 613 }
 614
 615 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 616 {
 617         int ret;
 618         struct p9_fid *fid;
 619         unsigned long flags;
 620
 621         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
 622         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 623         if (!fid)
 624                 return ERR_PTR(-ENOMEM);
 625
 626         ret = p9_idpool_get(clnt->fidpool);
 627         if (ret < 0) {
 628                 ret = -ENOSPC;
 629                 goto error;
 630         }
 631         fid->fid = ret;
 632
 633         memset(&fid->qid, 0, sizeof(struct p9_qid));
 634         fid->mode = -1;
 635         fid->uid = current_fsuid();
 636         fid->clnt = clnt;
 637         fid->rdir = NULL;
 638         spin_lock_irqsave(&clnt->lock, flags);
 639         list_add(&fid->flist, &clnt->fidlist);
 640         spin_unlock_irqrestore(&clnt->lock, flags);
 641
 642         return fid;
 643
 644 error:
 645         kfree(fid);
 646         return ERR_PTR(ret);
 647 }
 648
 649 static void p9_fid_destroy(struct p9_fid *fid)
 650 {
 651         struct p9_client *clnt;
 652         unsigned long flags;
 653
 654         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
 655         clnt = fid->clnt;
 656         p9_idpool_put(fid->fid, clnt->fidpool);
 657         spin_lock_irqsave(&clnt->lock, flags);
 658         list_del(&fid->flist);
 659         spin_unlock_irqrestore(&clnt->lock, flags);
 660         kfree(fid->rdir);
 661         kfree(fid);
 662 }
 663
 664 int p9_client_version(struct p9_client *c)
 665 {
 666         int err = 0;
 667         struct p9_req_t *req;
 668         char *version;
 669         int msize;
 670
 671         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 672                                                 c->msize, c->proto_version);
 673
 674         switch (c->proto_version) {
 675         case p9_proto_2010L:
 676                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 677                                         c->msize, "9P2010.L");
 678                 break;
 679         case p9_proto_2000u:
 680                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 681                                         c->msize, "9P2000.u");
 682                 break;
 683         case p9_proto_legacy:
 684                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 685                                         c->msize, "9P2000");
 686                 break;
 687         default:
 688                 return -EINVAL;
 689                 break;
 690         }
 691
 692         if (IS_ERR(req))
 693                 return PTR_ERR(req);
 694
 695         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 696         if (err) {
 697                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
 698                 p9pdu_dump(1, req->rc);
 699                 goto error;
 700         }
 701
 702         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 703         if (!strncmp(version, "9P2010.L", 8))
 704                 c->proto_version = p9_proto_2010L;
 705         else if (!strncmp(version, "9P2000.u", 8))
 706                 c->proto_version = p9_proto_2000u;
 707         else if (!strncmp(version, "9P2000", 6))
 708                 c->proto_version = p9_proto_legacy;
 709         else {
 710                 err = -EREMOTEIO;
 711                 goto error;
 712         }
 713
 714         if (msize < c->msize)
 715                 c->msize = msize;
 716
 717 error:
 718         kfree(version);
 719         p9_free_req(c, req);
 720
 721         return err;
 722 }
 723 EXPORT_SYMBOL(p9_client_version);
 724
 725 struct p9_client *p9_client_create(const char *dev_name, char *options)
 726 {
 727         int err;
 728         struct p9_client *clnt;
 729
 730         err = 0;
 731         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 732         if (!clnt)
 733                 return ERR_PTR(-ENOMEM);
 734
 735         clnt->trans_mod = NULL;
 736         clnt->trans = NULL;
 737         spin_lock_init(&clnt->lock);
 738         INIT_LIST_HEAD(&clnt->fidlist);
 739
 740         p9_tag_init(clnt);
 741
 742         err = parse_opts(options, clnt);
 743         if (err < 0)
 744                 goto free_client;
 745
 746         if (!clnt->trans_mod)
 747                 clnt->trans_mod = v9fs_get_default_trans();
 748
 749         if (clnt->trans_mod == NULL) {
 750                 err = -EPROTONOSUPPORT;
 751                 P9_DPRINTK(P9_DEBUG_ERROR,
 752                                 "No transport defined or default transport\n");
 753                 goto free_client;
 754         }
 755
 756         clnt->fidpool = p9_idpool_create();
 757         if (IS_ERR(clnt->fidpool)) {
 758                 err = PTR_ERR(clnt->fidpool);
 759                 clnt->fidpool = NULL;
 760                 goto put_trans;
 761         }
 762
 763         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
 764                 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
 765
 766         err = clnt->trans_mod->create(clnt, dev_name, options);
 767         if (err)
 768                 goto destroy_fidpool;
 769
 770         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 771                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 772
 773         err = p9_client_version(clnt);
 774         if (err)
 775                 goto close_trans;
 776
 777         return clnt;
 778
 779 close_trans:
 780         clnt->trans_mod->close(clnt);
 781 destroy_fidpool:
 782         p9_idpool_destroy(clnt->fidpool);
 783 put_trans:
 784         v9fs_put_trans(clnt->trans_mod);
 785 free_client:
 786         kfree(clnt);
 787         return ERR_PTR(err);
 788 }
 789 EXPORT_SYMBOL(p9_client_create);
 790
 791 void p9_client_destroy(struct p9_client *clnt)
 792 {
 793         struct p9_fid *fid, *fidptr;
 794
 795         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
 796
 797         if (clnt->trans_mod)
 798                 clnt->trans_mod->close(clnt);
 799
 800         v9fs_put_trans(clnt->trans_mod);
 801
 802         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 803                 p9_fid_destroy(fid);
 804
 805         if (clnt->fidpool)
 806                 p9_idpool_destroy(clnt->fidpool);
 807
 808         p9_tag_cleanup(clnt);
 809
 810         kfree(clnt);
 811 }
 812 EXPORT_SYMBOL(p9_client_destroy);
 813
 814 void p9_client_disconnect(struct p9_client *clnt)
 815 {
 816         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 817         clnt->status = Disconnected;
 818 }
 819 EXPORT_SYMBOL(p9_client_disconnect);
 820
 821 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 822         char *uname, u32 n_uname, char *aname)
 823 {
 824         int err;
 825         struct p9_req_t *req;
 826         struct p9_fid *fid;
 827         struct p9_qid qid;
 828
 829         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
 830                                         afid ? afid->fid : -1, uname, aname);
 831         err = 0;
 832
 833         fid = p9_fid_create(clnt);
 834         if (IS_ERR(fid)) {
 835                 err = PTR_ERR(fid);
 836                 fid = NULL;
 837                 goto error;
 838         }
 839
 840         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
 841                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 842         if (IS_ERR(req)) {
 843                 err = PTR_ERR(req);
 844                 goto error;
 845         }
 846
 847         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
 848         if (err) {
 849                 p9pdu_dump(1, req->rc);
 850                 p9_free_req(clnt, req);
 851                 goto error;
 852         }
 853
 854         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
 855                                         qid.type,
 856                                         (unsigned long long)qid.path,
 857                                         qid.version);
 858
 859         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
 860
 861         p9_free_req(clnt, req);
 862         return fid;
 863
 864 error:
 865         if (fid)
 866                 p9_fid_destroy(fid);
 867         return ERR_PTR(err);
 868 }
 869 EXPORT_SYMBOL(p9_client_attach);
 870
 871 struct p9_fid *
 872 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
 873 {
 874         int err;
 875         struct p9_req_t *req;
 876         struct p9_qid qid;
 877         struct p9_fid *afid;
 878
 879         P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
 880         err = 0;
 881
 882         afid = p9_fid_create(clnt);
 883         if (IS_ERR(afid)) {
 884                 err = PTR_ERR(afid);
 885                 afid = NULL;
 886                 goto error;
 887         }
 888
 889         req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
 890                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 891         if (IS_ERR(req)) {
 892                 err = PTR_ERR(req);
 893                 goto error;
 894         }
 895
 896         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
 897         if (err) {
 898                 p9pdu_dump(1, req->rc);
 899                 p9_free_req(clnt, req);
 900                 goto error;
 901         }
 902
 903         P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
 904                                         qid.type,
 905                                         (unsigned long long)qid.path,
 906                                         qid.version);
 907
 908         memmove(&afid->qid, &qid, sizeof(struct p9_qid));
 909         p9_free_req(clnt, req);
 910         return afid;
 911
 912 error:
 913         if (afid)
 914                 p9_fid_destroy(afid);
 915         return ERR_PTR(err);
 916 }
 917 EXPORT_SYMBOL(p9_client_auth);
 918
 919 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 920         int clone)
 921 {
 922         int err;
 923         struct p9_client *clnt;
 924         struct p9_fid *fid;
 925         struct p9_qid *wqids;
 926         struct p9_req_t *req;
 927         int16_t nwqids, count;
 928
 929         err = 0;
 930         clnt = oldfid->clnt;
 931         if (clone) {
 932                 fid = p9_fid_create(clnt);
 933                 if (IS_ERR(fid)) {
 934                         err = PTR_ERR(fid);
 935                         fid = NULL;
 936                         goto error;
 937                 }
 938
 939                 fid->uid = oldfid->uid;
 940         } else
 941                 fid = oldfid;
 942
 943
 944         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
 945                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
 946
 947         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
 948                                                                 nwname, wnames);
 949         if (IS_ERR(req)) {
 950                 err = PTR_ERR(req);
 951                 goto error;
 952         }
 953
 954         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
 955         if (err) {
 956                 p9pdu_dump(1, req->rc);
 957                 p9_free_req(clnt, req);
 958                 goto clunk_fid;
 959         }
 960         p9_free_req(clnt, req);
 961
 962         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
 963
 964         if (nwqids != nwname) {
 965                 err = -ENOENT;
 966                 goto clunk_fid;
 967         }
 968
 969         for (count = 0; count < nwqids; count++)
 970                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
 971                         count, wqids[count].type,
 972                         (unsigned long long)wqids[count].path,
 973                         wqids[count].version);
 974
 975         if (nwname)
 976                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
 977         else
 978                 fid->qid = oldfid->qid;
 979
 980         return fid;
 981
 982 clunk_fid:
 983         p9_client_clunk(fid);
 984         fid = NULL;
 985
 986 error:
 987         if (fid && (fid != oldfid))
 988                 p9_fid_destroy(fid);
 989
 990         return ERR_PTR(err);
 991 }
 992 EXPORT_SYMBOL(p9_client_walk);
 993
 994 int p9_client_open(struct p9_fid *fid, int mode)
 995 {
 996         int err;
 997         struct p9_client *clnt;
 998         struct p9_req_t *req;
 999         struct p9_qid qid;
1000         int iounit;
1001
1002         P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
1003         err = 0;
1004         clnt = fid->clnt;
1005
1006         if (fid->mode != -1)
1007                 return -EINVAL;
1008
1009         req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1010         if (IS_ERR(req)) {
1011                 err = PTR_ERR(req);
1012                 goto error;
1013         }
1014
1015         err = p9pdu_readf(req->rc, clnt->proto_version, "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, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
1022                                 qid.type,
1023                                 (unsigned long long)qid.path,
1024                                 qid.version, iounit);
1025
1026         fid->mode = mode;
1027         fid->iounit = iounit;
1028
1029 free_and_error:
1030         p9_free_req(clnt, req);
1031 error:
1032         return err;
1033 }
1034 EXPORT_SYMBOL(p9_client_open);
1035
1036 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1037                      char *extension)
1038 {
1039         int err;
1040         struct p9_client *clnt;
1041         struct p9_req_t *req;
1042         struct p9_qid qid;
1043         int iounit;
1044
1045         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1046                                                 fid->fid, name, perm, mode);
1047         err = 0;
1048         clnt = fid->clnt;
1049
1050         if (fid->mode != -1)
1051                 return -EINVAL;
1052
1053         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1054                                 mode, extension);
1055         if (IS_ERR(req)) {
1056                 err = PTR_ERR(req);
1057                 goto error;
1058         }
1059
1060         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1061         if (err) {
1062                 p9pdu_dump(1, req->rc);
1063                 goto free_and_error;
1064         }
1065
1066         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1067                                 qid.type,
1068                                 (unsigned long long)qid.path,
1069                                 qid.version, iounit);
1070
1071         fid->mode = mode;
1072         fid->iounit = iounit;
1073
1074 free_and_error:
1075         p9_free_req(clnt, req);
1076 error:
1077         return err;
1078 }
1079 EXPORT_SYMBOL(p9_client_fcreate);
1080
1081 int p9_client_clunk(struct p9_fid *fid)
1082 {
1083         int err;
1084         struct p9_client *clnt;
1085         struct p9_req_t *req;
1086
1087         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1088         err = 0;
1089         clnt = fid->clnt;
1090
1091         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1092         if (IS_ERR(req)) {
1093                 err = PTR_ERR(req);
1094                 goto error;
1095         }
1096
1097         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1098
1099         p9_free_req(clnt, req);
1100         p9_fid_destroy(fid);
1101
1102 error:
1103         return err;
1104 }
1105 EXPORT_SYMBOL(p9_client_clunk);
1106
1107 int p9_client_remove(struct p9_fid *fid)
1108 {
1109         int err;
1110         struct p9_client *clnt;
1111         struct p9_req_t *req;
1112
1113         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1114         err = 0;
1115         clnt = fid->clnt;
1116
1117         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1118         if (IS_ERR(req)) {
1119                 err = PTR_ERR(req);
1120                 goto error;
1121         }
1122
1123         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1124
1125         p9_free_req(clnt, req);
1126         p9_fid_destroy(fid);
1127
1128 error:
1129         return err;
1130 }
1131 EXPORT_SYMBOL(p9_client_remove);
1132
1133 int
1134 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1135                                                                 u32 count)
1136 {
1137         int err, rsize, total;
1138         struct p9_client *clnt;
1139         struct p9_req_t *req;
1140         char *dataptr;
1141
1142         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1143                                         (long long unsigned) offset, count);
1144         err = 0;
1145         clnt = fid->clnt;
1146         total = 0;
1147
1148         rsize = fid->iounit;
1149         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1150                 rsize = clnt->msize - P9_IOHDRSZ;
1151
1152         if (count < rsize)
1153                 rsize = count;
1154
1155         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1156         if (IS_ERR(req)) {
1157                 err = PTR_ERR(req);
1158                 goto error;
1159         }
1160
1161         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1162         if (err) {
1163                 p9pdu_dump(1, req->rc);
1164                 goto free_and_error;
1165         }
1166
1167         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1168
1169         if (data) {
1170                 memmove(data, dataptr, count);
1171         }
1172
1173         if (udata) {
1174                 err = copy_to_user(udata, dataptr, count);
1175                 if (err) {
1176                         err = -EFAULT;
1177                         goto free_and_error;
1178                 }
1179         }
1180
1181         p9_free_req(clnt, req);
1182         return count;
1183
1184 free_and_error:
1185         p9_free_req(clnt, req);
1186 error:
1187         return err;
1188 }
1189 EXPORT_SYMBOL(p9_client_read);
1190
1191 int
1192 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1193                                                         u64 offset, u32 count)
1194 {
1195         int err, rsize, total;
1196         struct p9_client *clnt;
1197         struct p9_req_t *req;
1198
1199         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1200                                 fid->fid, (long long unsigned) offset, count);
1201         err = 0;
1202         clnt = fid->clnt;
1203         total = 0;
1204
1205         rsize = fid->iounit;
1206         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1207                 rsize = clnt->msize - P9_IOHDRSZ;
1208
1209         if (count < rsize)
1210                 rsize = count;
1211         if (data)
1212                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1213                                                                 rsize, data);
1214         else
1215                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1216                                                                 rsize, udata);
1217         if (IS_ERR(req)) {
1218                 err = PTR_ERR(req);
1219                 goto error;
1220         }
1221
1222         err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1223         if (err) {
1224                 p9pdu_dump(1, req->rc);
1225                 goto free_and_error;
1226         }
1227
1228         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1229
1230         p9_free_req(clnt, req);
1231         return count;
1232
1233 free_and_error:
1234         p9_free_req(clnt, req);
1235 error:
1236         return err;
1237 }
1238 EXPORT_SYMBOL(p9_client_write);
1239
1240 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1241 {
1242         int err;
1243         struct p9_client *clnt;
1244         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1245         struct p9_req_t *req;
1246         u16 ignored;
1247
1248         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1249
1250         if (!ret)
1251                 return ERR_PTR(-ENOMEM);
1252
1253         err = 0;
1254         clnt = fid->clnt;
1255
1256         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1257         if (IS_ERR(req)) {
1258                 err = PTR_ERR(req);
1259                 goto error;
1260         }
1261
1262         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1263         if (err) {
1264                 p9pdu_dump(1, req->rc);
1265                 p9_free_req(clnt, req);
1266                 goto error;
1267         }
1268
1269         P9_DPRINTK(P9_DEBUG_9P,
1270                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1271                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1272                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1273                 "<<<    uid=%d gid=%d n_muid=%d\n",
1274                 ret->size, ret->type, ret->dev, ret->qid.type,
1275                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1276                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1277                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1278                 ret->n_uid, ret->n_gid, ret->n_muid);
1279
1280         p9_free_req(clnt, req);
1281         return ret;
1282
1283 error:
1284         kfree(ret);
1285         return ERR_PTR(err);
1286 }
1287 EXPORT_SYMBOL(p9_client_stat);
1288
1289 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1290 {
1291         int ret;
1292
1293         /* NOTE: size shouldn't include its own length */
1294         /* size[2] type[2] dev[4] qid[13] */
1295         /* mode[4] atime[4] mtime[4] length[8]*/
1296         /* name[s] uid[s] gid[s] muid[s] */
1297         ret = 2+4+13+4+4+4+8+2+2+2+2;
1298
1299         if (wst->name)
1300                 ret += strlen(wst->name);
1301         if (wst->uid)
1302                 ret += strlen(wst->uid);
1303         if (wst->gid)
1304                 ret += strlen(wst->gid);
1305         if (wst->muid)
1306                 ret += strlen(wst->muid);
1307
1308         if (proto_version == p9_proto_2000u) {
1309                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1310                 if (wst->extension)
1311                         ret += strlen(wst->extension);
1312         }
1313
1314         return ret;
1315 }
1316
1317 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1318 {
1319         int err;
1320         struct p9_req_t *req;
1321         struct p9_client *clnt;
1322
1323         err = 0;
1324         clnt = fid->clnt;
1325         wst->size = p9_client_statsize(wst, clnt->proto_version);
1326         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1327         P9_DPRINTK(P9_DEBUG_9P,
1328                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1329                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1330                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1331                 "     uid=%d gid=%d n_muid=%d\n",
1332                 wst->size, wst->type, wst->dev, wst->qid.type,
1333                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1334                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1335                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1336                 wst->n_uid, wst->n_gid, wst->n_muid);
1337
1338         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1339         if (IS_ERR(req)) {
1340                 err = PTR_ERR(req);
1341                 goto error;
1342         }
1343
1344         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1345
1346         p9_free_req(clnt, req);
1347 error:
1348         return err;
1349 }
1350 EXPORT_SYMBOL(p9_client_wstat);