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  * parse_options - parse mount options into client structure
  64  * @opts: options string passed from mount
  65  * @clnt: existing v9fs client 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         kfree(options);
 121         return ret;
 122 }
 123
 124 /**
 125  * p9_tag_alloc - lookup/allocate a request by tag
 126  * @c: client session to lookup tag within
 127  * @tag: numeric id for transaction
 128  *
 129  * this is a simple array lookup, but will grow the
 130  * request_slots as necessary to accomodate transaction
 131  * ids which did not previously have a slot.
 132  *
 133  * this code relies on the client spinlock to manage locks, its
 134  * possible we should switch to something else, but I'd rather
 135  * stick with something low-overhead for the common case.
 136  *
 137  */
 138
 139 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
 140 {
 141         unsigned long flags;
 142         int row, col;
 143         struct p9_req_t *req;
 144
 145         /* This looks up the original request by tag so we know which
 146          * buffer to read the data into */
 147         tag++;
 148
 149         if (tag >= c->max_tag) {
 150                 spin_lock_irqsave(&c->lock, flags);
 151                 /* check again since original check was outside of lock */
 152                 while (tag >= c->max_tag) {
 153                         row = (tag / P9_ROW_MAXTAG);
 154                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 155                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 156
 157                         if (!c->reqs[row]) {
 158                                 printk(KERN_ERR "Couldn't grow tag array\n");
 159                                 spin_unlock_irqrestore(&c->lock, flags);
 160                                 return ERR_PTR(-ENOMEM);
 161                         }
 162                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 163                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 164                                 c->reqs[row][col].tc = NULL;
 165                         }
 166                         c->max_tag += P9_ROW_MAXTAG;
 167                 }
 168                 spin_unlock_irqrestore(&c->lock, flags);
 169         }
 170         row = tag / P9_ROW_MAXTAG;
 171         col = tag % P9_ROW_MAXTAG;
 172
 173         req = &c->reqs[row][col];
 174         if (!req->tc) {
 175                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
 176                 if (!req->wq) {
 177                         printk(KERN_ERR "Couldn't grow tag array\n");
 178                         return ERR_PTR(-ENOMEM);
 179                 }
 180                 init_waitqueue_head(req->wq);
 181                 req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 182                                                                 GFP_KERNEL);
 183                 req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 184                                                                 GFP_KERNEL);
 185                 if ((!req->tc) || (!req->rc)) {
 186                         printk(KERN_ERR "Couldn't grow tag array\n");
 187                         kfree(req->tc);
 188                         kfree(req->rc);
 189                         kfree(req->wq);
 190                         req->tc = req->rc = NULL;
 191                         req->wq = NULL;
 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->tc->tag = tag-1;
 204         req->status = REQ_STATUS_ALLOC;
 205
 206         return &c->reqs[row][col];
 207 }
 208
 209 /**
 210  * p9_tag_lookup - lookup a request by tag
 211  * @c: client session to lookup tag within
 212  * @tag: numeric id for transaction
 213  *
 214  */
 215
 216 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 217 {
 218         int row, col;
 219
 220         /* This looks up the original request by tag so we know which
 221          * buffer to read the data into */
 222         tag++;
 223
 224         BUG_ON(tag >= c->max_tag);
 225
 226         row = tag / P9_ROW_MAXTAG;
 227         col = tag % P9_ROW_MAXTAG;
 228
 229         return &c->reqs[row][col];
 230 }
 231 EXPORT_SYMBOL(p9_tag_lookup);
 232
 233 /**
 234  * p9_tag_init - setup tags structure and contents
 235  * @c:  v9fs client struct
 236  *
 237  * This initializes the tags structure for each client instance.
 238  *
 239  */
 240
 241 static int p9_tag_init(struct p9_client *c)
 242 {
 243         int err = 0;
 244
 245         c->tagpool = p9_idpool_create();
 246         if (IS_ERR(c->tagpool)) {
 247                 err = PTR_ERR(c->tagpool);
 248                 c->tagpool = NULL;
 249                 goto error;
 250         }
 251
 252         p9_idpool_get(c->tagpool); /* reserve tag 0 */
 253
 254         c->max_tag = 0;
 255 error:
 256         return err;
 257 }
 258
 259 /**
 260  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 261  * @c:  v9fs client struct
 262  *
 263  * This frees resources associated with the tags structure
 264  *
 265  */
 266 static void p9_tag_cleanup(struct p9_client *c)
 267 {
 268         int row, col;
 269
 270         /* check to insure all requests are idle */
 271         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 272                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 273                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 274                                 P9_DPRINTK(P9_DEBUG_MUX,
 275                                   "Attempting to cleanup non-free tag %d,%d\n",
 276                                   row, col);
 277                                 /* TODO: delay execution of cleanup */
 278                                 return;
 279                         }
 280                 }
 281         }
 282
 283         if (c->tagpool)
 284                 p9_idpool_destroy(c->tagpool);
 285
 286         /* free requests associated with tags */
 287         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 288                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 289                         kfree(c->reqs[row][col].wq);
 290                         kfree(c->reqs[row][col].tc);
 291                         kfree(c->reqs[row][col].rc);
 292                 }
 293                 kfree(c->reqs[row]);
 294         }
 295         c->max_tag = 0;
 296 }
 297
 298 /**
 299  * p9_free_req - free a request and clean-up as necessary
 300  * c: client state
 301  * r: request to release
 302  *
 303  */
 304
 305 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 306 {
 307         int tag = r->tc->tag;
 308         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 309
 310         r->status = REQ_STATUS_IDLE;
 311         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 312                 p9_idpool_put(tag, c->tagpool);
 313 }
 314
 315 /**
 316  * p9_client_cb - call back from transport to client
 317  * c: client state
 318  * req: request received
 319  *
 320  */
 321 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
 322 {
 323         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 324         wake_up(req->wq);
 325         P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 326 }
 327 EXPORT_SYMBOL(p9_client_cb);
 328
 329 /**
 330  * p9_parse_header - parse header arguments out of a packet
 331  * @pdu: packet to parse
 332  * @size: size of packet
 333  * @type: type of request
 334  * @tag: tag of packet
 335  * @rewind: set if we need to rewind offset afterwards
 336  */
 337
 338 int
 339 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 340                                                                 int rewind)
 341 {
 342         int8_t r_type;
 343         int16_t r_tag;
 344         int32_t r_size;
 345         int offset = pdu->offset;
 346         int err;
 347
 348         pdu->offset = 0;
 349         if (pdu->size == 0)
 350                 pdu->size = 7;
 351
 352         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 353         if (err)
 354                 goto rewind_and_exit;
 355
 356         pdu->size = r_size;
 357         pdu->id = r_type;
 358         pdu->tag = r_tag;
 359
 360         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
 361                                                         pdu->id, pdu->tag);
 362
 363         if (type)
 364                 *type = r_type;
 365         if (tag)
 366                 *tag = r_tag;
 367         if (size)
 368                 *size = r_size;
 369
 370
 371 rewind_and_exit:
 372         if (rewind)
 373                 pdu->offset = offset;
 374         return err;
 375 }
 376 EXPORT_SYMBOL(p9_parse_header);
 377
 378 /**
 379  * p9_check_errors - check 9p packet for error return and process it
 380  * @c: current client instance
 381  * @req: request to parse and check for error conditions
 382  *
 383  * returns error code if one is discovered, otherwise returns 0
 384  *
 385  * this will have to be more complicated if we have multiple
 386  * error packet types
 387  */
 388
 389 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 390 {
 391         int8_t type;
 392         int err;
 393
 394         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 395         if (err) {
 396                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 397                 return err;
 398         }
 399
 400         if (type == P9_RERROR) {
 401                 int ecode;
 402                 char *ename;
 403
 404                 err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
 405                 if (err) {
 406                         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
 407                                                                         err);
 408                         return err;
 409                 }
 410
 411                 if (c->dotu)
 412                         err = -ecode;
 413
 414                 if (!err || !IS_ERR_VALUE(err))
 415                         err = p9_errstr2errno(ename, strlen(ename));
 416
 417                 P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
 418
 419                 kfree(ename);
 420         } else
 421                 err = 0;
 422
 423         return err;
 424 }
 425
 426 /**
 427  * p9_client_flush - flush (cancel) a request
 428  * @c: client state
 429  * @oldreq: request to cancel
 430  *
 431  * This sents a flush for a particular requests and links
 432  * the flush request to the original request.  The current
 433  * code only supports a single flush request although the protocol
 434  * allows for multiple flush requests to be sent for a single request.
 435  *
 436  */
 437
 438 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 439 {
 440         struct p9_req_t *req;
 441         int16_t oldtag;
 442         int err;
 443
 444         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 445         if (err)
 446                 return err;
 447
 448         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 449
 450         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 451         if (IS_ERR(req))
 452                 return PTR_ERR(req);
 453
 454
 455         /* if we haven't received a response for oldreq,
 456            remove it from the list. */
 457         spin_lock(&c->lock);
 458         if (oldreq->status == REQ_STATUS_FLSH)
 459                 list_del(&oldreq->req_list);
 460         spin_unlock(&c->lock);
 461
 462         p9_free_req(c, req);
 463         return 0;
 464 }
 465
 466 /**
 467  * p9_client_rpc - issue a request and wait for a response
 468  * @c: client session
 469  * @type: type of request
 470  * @fmt: protocol format string (see protocol.c)
 471  *
 472  * Returns request structure (which client must free using p9_free_req)
 473  */
 474
 475 static struct p9_req_t *
 476 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 477 {
 478         va_list ap;
 479         int tag, err;
 480         struct p9_req_t *req;
 481         unsigned long flags;
 482         int sigpending;
 483
 484         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 485
 486         if (c->status != Connected)
 487                 return ERR_PTR(-EIO);
 488
 489         if (signal_pending(current)) {
 490                 sigpending = 1;
 491                 clear_thread_flag(TIF_SIGPENDING);
 492         } else
 493                 sigpending = 0;
 494
 495         tag = P9_NOTAG;
 496         if (type != P9_TVERSION) {
 497                 tag = p9_idpool_get(c->tagpool);
 498                 if (tag < 0)
 499                         return ERR_PTR(-ENOMEM);
 500         }
 501
 502         req = p9_tag_alloc(c, tag);
 503         if (IS_ERR(req))
 504                 return req;
 505
 506         /* marshall the data */
 507         p9pdu_prepare(req->tc, tag, type);
 508         va_start(ap, fmt);
 509         err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
 510         va_end(ap);
 511         p9pdu_finalize(req->tc);
 512
 513         err = c->trans_mod->request(c, req);
 514         if (err < 0) {
 515                 c->status = Disconnected;
 516                 goto reterr;
 517         }
 518
 519         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
 520         err = wait_event_interruptible(*req->wq,
 521                                                 req->status >= REQ_STATUS_RCVD);
 522         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
 523                                                 req->wq, tag, err);
 524
 525         if (req->status == REQ_STATUS_ERROR) {
 526                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 527                 err = req->t_err;
 528         }
 529
 530         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 531                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
 532                 sigpending = 1;
 533                 clear_thread_flag(TIF_SIGPENDING);
 534
 535                 if (c->trans_mod->cancel(c, req))
 536                         p9_client_flush(c, req);
 537
 538                 /* if we received the response anyway, don't signal error */
 539                 if (req->status == REQ_STATUS_RCVD)
 540                         err = 0;
 541         }
 542
 543         if (sigpending) {
 544                 spin_lock_irqsave(&current->sighand->siglock, flags);
 545                 recalc_sigpending();
 546                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 547         }
 548
 549         if (err < 0)
 550                 goto reterr;
 551
 552         err = p9_check_errors(c, req);
 553         if (!err) {
 554                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
 555                 return req;
 556         }
 557
 558 reterr:
 559         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
 560                                                                         err);
 561         p9_free_req(c, req);
 562         return ERR_PTR(err);
 563 }
 564
 565 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 566 {
 567         int ret;
 568         struct p9_fid *fid;
 569         unsigned long flags;
 570
 571         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
 572         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 573         if (!fid)
 574                 return ERR_PTR(-ENOMEM);
 575
 576         ret = p9_idpool_get(clnt->fidpool);
 577         if (ret < 0) {
 578                 ret = -ENOSPC;
 579                 goto error;
 580         }
 581         fid->fid = ret;
 582
 583         memset(&fid->qid, 0, sizeof(struct p9_qid));
 584         fid->mode = -1;
 585         fid->rdir_fpos = 0;
 586         fid->uid = current_fsuid();
 587         fid->clnt = clnt;
 588         fid->aux = NULL;
 589
 590         spin_lock_irqsave(&clnt->lock, flags);
 591         list_add(&fid->flist, &clnt->fidlist);
 592         spin_unlock_irqrestore(&clnt->lock, flags);
 593
 594         return fid;
 595
 596 error:
 597         kfree(fid);
 598         return ERR_PTR(ret);
 599 }
 600
 601 static void p9_fid_destroy(struct p9_fid *fid)
 602 {
 603         struct p9_client *clnt;
 604         unsigned long flags;
 605
 606         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
 607         clnt = fid->clnt;
 608         p9_idpool_put(fid->fid, clnt->fidpool);
 609         spin_lock_irqsave(&clnt->lock, flags);
 610         list_del(&fid->flist);
 611         spin_unlock_irqrestore(&clnt->lock, flags);
 612         kfree(fid);
 613 }
 614
 615 int p9_client_version(struct p9_client *c)
 616 {
 617         int err = 0;
 618         struct p9_req_t *req;
 619         char *version;
 620         int msize;
 621
 622         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
 623                                                         c->msize, c->dotu);
 624         req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
 625                                 c->dotu ? "9P2000.u" : "9P2000");
 626         if (IS_ERR(req))
 627                 return PTR_ERR(req);
 628
 629         err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
 630         if (err) {
 631                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
 632                 p9pdu_dump(1, req->rc);
 633                 goto error;
 634         }
 635
 636         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 637         if (!memcmp(version, "9P2000.u", 8))
 638                 c->dotu = 1;
 639         else if (!memcmp(version, "9P2000", 6))
 640                 c->dotu = 0;
 641         else {
 642                 err = -EREMOTEIO;
 643                 goto error;
 644         }
 645
 646         if (msize < c->msize)
 647                 c->msize = msize;
 648
 649 error:
 650         kfree(version);
 651         p9_free_req(c, req);
 652
 653         return err;
 654 }
 655 EXPORT_SYMBOL(p9_client_version);
 656
 657 struct p9_client *p9_client_create(const char *dev_name, char *options)
 658 {
 659         int err;
 660         struct p9_client *clnt;
 661
 662         err = 0;
 663         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 664         if (!clnt)
 665                 return ERR_PTR(-ENOMEM);
 666
 667         clnt->trans_mod = NULL;
 668         clnt->trans = NULL;
 669         spin_lock_init(&clnt->lock);
 670         INIT_LIST_HEAD(&clnt->fidlist);
 671         clnt->fidpool = p9_idpool_create();
 672         if (IS_ERR(clnt->fidpool)) {
 673                 err = PTR_ERR(clnt->fidpool);
 674                 clnt->fidpool = NULL;
 675                 goto error;
 676         }
 677
 678         p9_tag_init(clnt);
 679
 680         err = parse_opts(options, clnt);
 681         if (err < 0)
 682                 goto error;
 683
 684         if (!clnt->trans_mod)
 685                 clnt->trans_mod = v9fs_get_default_trans();
 686
 687         if (clnt->trans_mod == NULL) {
 688                 err = -EPROTONOSUPPORT;
 689                 P9_DPRINTK(P9_DEBUG_ERROR,
 690                                 "No transport defined or default transport\n");
 691                 goto error;
 692         }
 693
 694         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
 695                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 696
 697         err = clnt->trans_mod->create(clnt, dev_name, options);
 698         if (err)
 699                 goto error;
 700
 701         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 702                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 703
 704         err = p9_client_version(clnt);
 705         if (err)
 706                 goto error;
 707
 708         return clnt;
 709
 710 error:
 711         p9_client_destroy(clnt);
 712         return ERR_PTR(err);
 713 }
 714 EXPORT_SYMBOL(p9_client_create);
 715
 716 void p9_client_destroy(struct p9_client *clnt)
 717 {
 718         struct p9_fid *fid, *fidptr;
 719
 720         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
 721
 722         if (clnt->trans_mod)
 723                 clnt->trans_mod->close(clnt);
 724
 725         v9fs_put_trans(clnt->trans_mod);
 726
 727         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 728                 p9_fid_destroy(fid);
 729
 730         if (clnt->fidpool)
 731                 p9_idpool_destroy(clnt->fidpool);
 732
 733         p9_tag_cleanup(clnt);
 734
 735         kfree(clnt);
 736 }
 737 EXPORT_SYMBOL(p9_client_destroy);
 738
 739 void p9_client_disconnect(struct p9_client *clnt)
 740 {
 741         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 742         clnt->status = Disconnected;
 743 }
 744 EXPORT_SYMBOL(p9_client_disconnect);
 745
 746 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 747         char *uname, u32 n_uname, char *aname)
 748 {
 749         int err;
 750         struct p9_req_t *req;
 751         struct p9_fid *fid;
 752         struct p9_qid qid;
 753
 754         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
 755                                         afid ? afid->fid : -1, uname, aname);
 756         err = 0;
 757
 758         fid = p9_fid_create(clnt);
 759         if (IS_ERR(fid)) {
 760                 err = PTR_ERR(fid);
 761                 fid = NULL;
 762                 goto error;
 763         }
 764
 765         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
 766                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 767         if (IS_ERR(req)) {
 768                 err = PTR_ERR(req);
 769                 goto error;
 770         }
 771
 772         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 773         if (err) {
 774                 p9pdu_dump(1, req->rc);
 775                 p9_free_req(clnt, req);
 776                 goto error;
 777         }
 778
 779         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
 780                                         qid.type,
 781                                         (unsigned long long)qid.path,
 782                                         qid.version);
 783
 784         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
 785
 786         p9_free_req(clnt, req);
 787         return fid;
 788
 789 error:
 790         if (fid)
 791                 p9_fid_destroy(fid);
 792         return ERR_PTR(err);
 793 }
 794 EXPORT_SYMBOL(p9_client_attach);
 795
 796 struct p9_fid *
 797 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
 798 {
 799         int err;
 800         struct p9_req_t *req;
 801         struct p9_qid qid;
 802         struct p9_fid *afid;
 803
 804         P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
 805         err = 0;
 806
 807         afid = p9_fid_create(clnt);
 808         if (IS_ERR(afid)) {
 809                 err = PTR_ERR(afid);
 810                 afid = NULL;
 811                 goto error;
 812         }
 813
 814         req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
 815                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 816         if (IS_ERR(req)) {
 817                 err = PTR_ERR(req);
 818                 goto error;
 819         }
 820
 821         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 822         if (err) {
 823                 p9pdu_dump(1, req->rc);
 824                 p9_free_req(clnt, req);
 825                 goto error;
 826         }
 827
 828         P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
 829                                         qid.type,
 830                                         (unsigned long long)qid.path,
 831                                         qid.version);
 832
 833         memmove(&afid->qid, &qid, sizeof(struct p9_qid));
 834         p9_free_req(clnt, req);
 835         return afid;
 836
 837 error:
 838         if (afid)
 839                 p9_fid_destroy(afid);
 840         return ERR_PTR(err);
 841 }
 842 EXPORT_SYMBOL(p9_client_auth);
 843
 844 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 845         int clone)
 846 {
 847         int err;
 848         struct p9_client *clnt;
 849         struct p9_fid *fid;
 850         struct p9_qid *wqids;
 851         struct p9_req_t *req;
 852         int16_t nwqids, count;
 853
 854         err = 0;
 855         clnt = oldfid->clnt;
 856         if (clone) {
 857                 fid = p9_fid_create(clnt);
 858                 if (IS_ERR(fid)) {
 859                         err = PTR_ERR(fid);
 860                         fid = NULL;
 861                         goto error;
 862                 }
 863
 864                 fid->uid = oldfid->uid;
 865         } else
 866                 fid = oldfid;
 867
 868
 869         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
 870                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
 871
 872         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
 873                                                                 nwname, wnames);
 874         if (IS_ERR(req)) {
 875                 err = PTR_ERR(req);
 876                 goto error;
 877         }
 878
 879         err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
 880         if (err) {
 881                 p9pdu_dump(1, req->rc);
 882                 p9_free_req(clnt, req);
 883                 goto clunk_fid;
 884         }
 885         p9_free_req(clnt, req);
 886
 887         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
 888
 889         if (nwqids != nwname) {
 890                 err = -ENOENT;
 891                 goto clunk_fid;
 892         }
 893
 894         for (count = 0; count < nwqids; count++)
 895                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
 896                         count, wqids[count].type,
 897                         (unsigned long long)wqids[count].path,
 898                         wqids[count].version);
 899
 900         if (nwname)
 901                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
 902         else
 903                 fid->qid = oldfid->qid;
 904
 905         return fid;
 906
 907 clunk_fid:
 908         p9_client_clunk(fid);
 909         fid = NULL;
 910
 911 error:
 912         if (fid && (fid != oldfid))
 913                 p9_fid_destroy(fid);
 914
 915         return ERR_PTR(err);
 916 }
 917 EXPORT_SYMBOL(p9_client_walk);
 918
 919 int p9_client_open(struct p9_fid *fid, int mode)
 920 {
 921         int err;
 922         struct p9_client *clnt;
 923         struct p9_req_t *req;
 924         struct p9_qid qid;
 925         int iounit;
 926
 927         P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
 928         err = 0;
 929         clnt = fid->clnt;
 930
 931         if (fid->mode != -1)
 932                 return -EINVAL;
 933
 934         req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
 935         if (IS_ERR(req)) {
 936                 err = PTR_ERR(req);
 937                 goto error;
 938         }
 939
 940         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 941         if (err) {
 942                 p9pdu_dump(1, req->rc);
 943                 goto free_and_error;
 944         }
 945
 946         P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
 947                                 qid.type,
 948                                 (unsigned long long)qid.path,
 949                                 qid.version, iounit);
 950
 951         fid->mode = mode;
 952         fid->iounit = iounit;
 953
 954 free_and_error:
 955         p9_free_req(clnt, req);
 956 error:
 957         return err;
 958 }
 959 EXPORT_SYMBOL(p9_client_open);
 960
 961 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 962                      char *extension)
 963 {
 964         int err;
 965         struct p9_client *clnt;
 966         struct p9_req_t *req;
 967         struct p9_qid qid;
 968         int iounit;
 969
 970         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
 971                                                 fid->fid, name, perm, mode);
 972         err = 0;
 973         clnt = fid->clnt;
 974
 975         if (fid->mode != -1)
 976                 return -EINVAL;
 977
 978         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
 979                                 mode, extension);
 980         if (IS_ERR(req)) {
 981                 err = PTR_ERR(req);
 982                 goto error;
 983         }
 984
 985         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 986         if (err) {
 987                 p9pdu_dump(1, req->rc);
 988                 goto free_and_error;
 989         }
 990
 991         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
 992                                 qid.type,
 993                                 (unsigned long long)qid.path,
 994                                 qid.version, iounit);
 995
 996         fid->mode = mode;
 997         fid->iounit = iounit;
 998
 999 free_and_error:
1000         p9_free_req(clnt, req);
1001 error:
1002         return err;
1003 }
1004 EXPORT_SYMBOL(p9_client_fcreate);
1005
1006 int p9_client_clunk(struct p9_fid *fid)
1007 {
1008         int err;
1009         struct p9_client *clnt;
1010         struct p9_req_t *req;
1011
1012         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1013         err = 0;
1014         clnt = fid->clnt;
1015
1016         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1017         if (IS_ERR(req)) {
1018                 err = PTR_ERR(req);
1019                 goto error;
1020         }
1021
1022         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1023
1024         p9_free_req(clnt, req);
1025         p9_fid_destroy(fid);
1026
1027 error:
1028         return err;
1029 }
1030 EXPORT_SYMBOL(p9_client_clunk);
1031
1032 int p9_client_remove(struct p9_fid *fid)
1033 {
1034         int err;
1035         struct p9_client *clnt;
1036         struct p9_req_t *req;
1037
1038         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1039         err = 0;
1040         clnt = fid->clnt;
1041
1042         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1043         if (IS_ERR(req)) {
1044                 err = PTR_ERR(req);
1045                 goto error;
1046         }
1047
1048         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1049
1050         p9_free_req(clnt, req);
1051         p9_fid_destroy(fid);
1052
1053 error:
1054         return err;
1055 }
1056 EXPORT_SYMBOL(p9_client_remove);
1057
1058 int
1059 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1060                                                                 u32 count)
1061 {
1062         int err, rsize, total;
1063         struct p9_client *clnt;
1064         struct p9_req_t *req;
1065         char *dataptr;
1066
1067         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1068                                         (long long unsigned) offset, count);
1069         err = 0;
1070         clnt = fid->clnt;
1071         total = 0;
1072
1073         rsize = fid->iounit;
1074         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1075                 rsize = clnt->msize - P9_IOHDRSZ;
1076
1077         if (count < rsize)
1078                 rsize = count;
1079
1080         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1081         if (IS_ERR(req)) {
1082                 err = PTR_ERR(req);
1083                 goto error;
1084         }
1085
1086         err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1087         if (err) {
1088                 p9pdu_dump(1, req->rc);
1089                 goto free_and_error;
1090         }
1091
1092         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1093
1094         if (data) {
1095                 memmove(data, dataptr, count);
1096         }
1097
1098         if (udata) {
1099                 err = copy_to_user(udata, dataptr, count);
1100                 if (err) {
1101                         err = -EFAULT;
1102                         goto free_and_error;
1103                 }
1104         }
1105
1106         p9_free_req(clnt, req);
1107         return count;
1108
1109 free_and_error:
1110         p9_free_req(clnt, req);
1111 error:
1112         return err;
1113 }
1114 EXPORT_SYMBOL(p9_client_read);
1115
1116 int
1117 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1118                                                         u64 offset, u32 count)
1119 {
1120         int err, rsize, total;
1121         struct p9_client *clnt;
1122         struct p9_req_t *req;
1123
1124         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1125                                 fid->fid, (long long unsigned) offset, count);
1126         err = 0;
1127         clnt = fid->clnt;
1128         total = 0;
1129
1130         rsize = fid->iounit;
1131         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1132                 rsize = clnt->msize - P9_IOHDRSZ;
1133
1134         if (count < rsize)
1135                 rsize = count;
1136         if (data)
1137                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1138                                                                 rsize, data);
1139         else
1140                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1141                                                                 rsize, udata);
1142         if (IS_ERR(req)) {
1143                 err = PTR_ERR(req);
1144                 goto error;
1145         }
1146
1147         err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1148         if (err) {
1149                 p9pdu_dump(1, req->rc);
1150                 goto free_and_error;
1151         }
1152
1153         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1154
1155         p9_free_req(clnt, req);
1156         return count;
1157
1158 free_and_error:
1159         p9_free_req(clnt, req);
1160 error:
1161         return err;
1162 }
1163 EXPORT_SYMBOL(p9_client_write);
1164
1165 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1166 {
1167         int err;
1168         struct p9_client *clnt;
1169         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1170         struct p9_req_t *req;
1171         u16 ignored;
1172
1173         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1174
1175         if (!ret)
1176                 return ERR_PTR(-ENOMEM);
1177
1178         err = 0;
1179         clnt = fid->clnt;
1180
1181         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1182         if (IS_ERR(req)) {
1183                 err = PTR_ERR(req);
1184                 goto error;
1185         }
1186
1187         err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1188         if (err) {
1189                 p9pdu_dump(1, req->rc);
1190                 p9_free_req(clnt, req);
1191                 goto error;
1192         }
1193
1194         P9_DPRINTK(P9_DEBUG_9P,
1195                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1196                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1197                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1198                 "<<<    uid=%d gid=%d n_muid=%d\n",
1199                 ret->size, ret->type, ret->dev, ret->qid.type,
1200                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1201                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1202                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1203                 ret->n_uid, ret->n_gid, ret->n_muid);
1204
1205         p9_free_req(clnt, req);
1206         return ret;
1207
1208 error:
1209         kfree(ret);
1210         return ERR_PTR(err);
1211 }
1212 EXPORT_SYMBOL(p9_client_stat);
1213
1214 static int p9_client_statsize(struct p9_wstat *wst, int optional)
1215 {
1216         int ret;
1217
1218         /* size[2] type[2] dev[4] qid[13] */
1219         /* mode[4] atime[4] mtime[4] length[8]*/
1220         /* name[s] uid[s] gid[s] muid[s] */
1221         ret = 2+2+4+13+4+4+4+8+2+2+2+2;
1222
1223         if (wst->name)
1224                 ret += strlen(wst->name);
1225         if (wst->uid)
1226                 ret += strlen(wst->uid);
1227         if (wst->gid)
1228                 ret += strlen(wst->gid);
1229         if (wst->muid)
1230                 ret += strlen(wst->muid);
1231
1232         if (optional) {
1233                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1234                 if (wst->extension)
1235                         ret += strlen(wst->extension);
1236         }
1237
1238         return ret;
1239 }
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         err = 0;
1248         clnt = fid->clnt;
1249         wst->size = p9_client_statsize(wst, clnt->dotu);
1250         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1251         P9_DPRINTK(P9_DEBUG_9P,
1252                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1253                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1254                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1255                 "     uid=%d gid=%d n_muid=%d\n",
1256                 wst->size, wst->type, wst->dev, wst->qid.type,
1257                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1258                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1259                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1260                 wst->n_uid, wst->n_gid, wst->n_muid);
1261
1262         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size, wst);
1263         if (IS_ERR(req)) {
1264                 err = PTR_ERR(req);
1265                 goto error;
1266         }
1267
1268         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1269
1270         p9_free_req(clnt, req);
1271 error:
1272         return err;
1273 }
1274 EXPORT_SYMBOL(p9_client_wstat);