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->uid = current_fsuid();
 586         fid->clnt = clnt;
 587         fid->rdir = NULL;
 588         spin_lock_irqsave(&clnt->lock, flags);
 589         list_add(&fid->flist, &clnt->fidlist);
 590         spin_unlock_irqrestore(&clnt->lock, flags);
 591
 592         return fid;
 593
 594 error:
 595         kfree(fid);
 596         return ERR_PTR(ret);
 597 }
 598
 599 static void p9_fid_destroy(struct p9_fid *fid)
 600 {
 601         struct p9_client *clnt;
 602         unsigned long flags;
 603
 604         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
 605         clnt = fid->clnt;
 606         p9_idpool_put(fid->fid, clnt->fidpool);
 607         spin_lock_irqsave(&clnt->lock, flags);
 608         list_del(&fid->flist);
 609         spin_unlock_irqrestore(&clnt->lock, flags);
 610         kfree(fid->rdir);
 611         kfree(fid);
 612 }
 613
 614 int p9_client_version(struct p9_client *c)
 615 {
 616         int err = 0;
 617         struct p9_req_t *req;
 618         char *version;
 619         int msize;
 620
 621         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
 622                                                         c->msize, c->dotu);
 623         req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
 624                                 c->dotu ? "9P2000.u" : "9P2000");
 625         if (IS_ERR(req))
 626                 return PTR_ERR(req);
 627
 628         err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
 629         if (err) {
 630                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
 631                 p9pdu_dump(1, req->rc);
 632                 goto error;
 633         }
 634
 635         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 636         if (!memcmp(version, "9P2000.u", 8))
 637                 c->dotu = 1;
 638         else if (!memcmp(version, "9P2000", 6))
 639                 c->dotu = 0;
 640         else {
 641                 err = -EREMOTEIO;
 642                 goto error;
 643         }
 644
 645         if (msize < c->msize)
 646                 c->msize = msize;
 647
 648 error:
 649         kfree(version);
 650         p9_free_req(c, req);
 651
 652         return err;
 653 }
 654 EXPORT_SYMBOL(p9_client_version);
 655
 656 struct p9_client *p9_client_create(const char *dev_name, char *options)
 657 {
 658         int err;
 659         struct p9_client *clnt;
 660
 661         err = 0;
 662         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 663         if (!clnt)
 664                 return ERR_PTR(-ENOMEM);
 665
 666         clnt->trans_mod = NULL;
 667         clnt->trans = NULL;
 668         spin_lock_init(&clnt->lock);
 669         INIT_LIST_HEAD(&clnt->fidlist);
 670         clnt->fidpool = p9_idpool_create();
 671         if (IS_ERR(clnt->fidpool)) {
 672                 err = PTR_ERR(clnt->fidpool);
 673                 clnt->fidpool = NULL;
 674                 goto error;
 675         }
 676
 677         p9_tag_init(clnt);
 678
 679         err = parse_opts(options, clnt);
 680         if (err < 0)
 681                 goto error;
 682
 683         if (!clnt->trans_mod)
 684                 clnt->trans_mod = v9fs_get_default_trans();
 685
 686         if (clnt->trans_mod == NULL) {
 687                 err = -EPROTONOSUPPORT;
 688                 P9_DPRINTK(P9_DEBUG_ERROR,
 689                                 "No transport defined or default transport\n");
 690                 goto error;
 691         }
 692
 693         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
 694                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 695
 696         err = clnt->trans_mod->create(clnt, dev_name, options);
 697         if (err)
 698                 goto error;
 699
 700         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 701                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 702
 703         err = p9_client_version(clnt);
 704         if (err)
 705                 goto error;
 706
 707         return clnt;
 708
 709 error:
 710         p9_client_destroy(clnt);
 711         return ERR_PTR(err);
 712 }
 713 EXPORT_SYMBOL(p9_client_create);
 714
 715 void p9_client_destroy(struct p9_client *clnt)
 716 {
 717         struct p9_fid *fid, *fidptr;
 718
 719         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
 720
 721         if (clnt->trans_mod)
 722                 clnt->trans_mod->close(clnt);
 723
 724         v9fs_put_trans(clnt->trans_mod);
 725
 726         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 727                 p9_fid_destroy(fid);
 728
 729         if (clnt->fidpool)
 730                 p9_idpool_destroy(clnt->fidpool);
 731
 732         p9_tag_cleanup(clnt);
 733
 734         kfree(clnt);
 735 }
 736 EXPORT_SYMBOL(p9_client_destroy);
 737
 738 void p9_client_disconnect(struct p9_client *clnt)
 739 {
 740         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 741         clnt->status = Disconnected;
 742 }
 743 EXPORT_SYMBOL(p9_client_disconnect);
 744
 745 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 746         char *uname, u32 n_uname, char *aname)
 747 {
 748         int err;
 749         struct p9_req_t *req;
 750         struct p9_fid *fid;
 751         struct p9_qid qid;
 752
 753         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
 754                                         afid ? afid->fid : -1, uname, aname);
 755         err = 0;
 756
 757         fid = p9_fid_create(clnt);
 758         if (IS_ERR(fid)) {
 759                 err = PTR_ERR(fid);
 760                 fid = NULL;
 761                 goto error;
 762         }
 763
 764         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
 765                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 766         if (IS_ERR(req)) {
 767                 err = PTR_ERR(req);
 768                 goto error;
 769         }
 770
 771         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 772         if (err) {
 773                 p9pdu_dump(1, req->rc);
 774                 p9_free_req(clnt, req);
 775                 goto error;
 776         }
 777
 778         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
 779                                         qid.type,
 780                                         (unsigned long long)qid.path,
 781                                         qid.version);
 782
 783         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
 784
 785         p9_free_req(clnt, req);
 786         return fid;
 787
 788 error:
 789         if (fid)
 790                 p9_fid_destroy(fid);
 791         return ERR_PTR(err);
 792 }
 793 EXPORT_SYMBOL(p9_client_attach);
 794
 795 struct p9_fid *
 796 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
 797 {
 798         int err;
 799         struct p9_req_t *req;
 800         struct p9_qid qid;
 801         struct p9_fid *afid;
 802
 803         P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
 804         err = 0;
 805
 806         afid = p9_fid_create(clnt);
 807         if (IS_ERR(afid)) {
 808                 err = PTR_ERR(afid);
 809                 afid = NULL;
 810                 goto error;
 811         }
 812
 813         req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
 814                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 815         if (IS_ERR(req)) {
 816                 err = PTR_ERR(req);
 817                 goto error;
 818         }
 819
 820         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 821         if (err) {
 822                 p9pdu_dump(1, req->rc);
 823                 p9_free_req(clnt, req);
 824                 goto error;
 825         }
 826
 827         P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
 828                                         qid.type,
 829                                         (unsigned long long)qid.path,
 830                                         qid.version);
 831
 832         memmove(&afid->qid, &qid, sizeof(struct p9_qid));
 833         p9_free_req(clnt, req);
 834         return afid;
 835
 836 error:
 837         if (afid)
 838                 p9_fid_destroy(afid);
 839         return ERR_PTR(err);
 840 }
 841 EXPORT_SYMBOL(p9_client_auth);
 842
 843 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 844         int clone)
 845 {
 846         int err;
 847         struct p9_client *clnt;
 848         struct p9_fid *fid;
 849         struct p9_qid *wqids;
 850         struct p9_req_t *req;
 851         int16_t nwqids, count;
 852
 853         err = 0;
 854         clnt = oldfid->clnt;
 855         if (clone) {
 856                 fid = p9_fid_create(clnt);
 857                 if (IS_ERR(fid)) {
 858                         err = PTR_ERR(fid);
 859                         fid = NULL;
 860                         goto error;
 861                 }
 862
 863                 fid->uid = oldfid->uid;
 864         } else
 865                 fid = oldfid;
 866
 867
 868         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
 869                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
 870
 871         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
 872                                                                 nwname, wnames);
 873         if (IS_ERR(req)) {
 874                 err = PTR_ERR(req);
 875                 goto error;
 876         }
 877
 878         err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
 879         if (err) {
 880                 p9pdu_dump(1, req->rc);
 881                 p9_free_req(clnt, req);
 882                 goto clunk_fid;
 883         }
 884         p9_free_req(clnt, req);
 885
 886         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
 887
 888         if (nwqids != nwname) {
 889                 err = -ENOENT;
 890                 goto clunk_fid;
 891         }
 892
 893         for (count = 0; count < nwqids; count++)
 894                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
 895                         count, wqids[count].type,
 896                         (unsigned long long)wqids[count].path,
 897                         wqids[count].version);
 898
 899         if (nwname)
 900                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
 901         else
 902                 fid->qid = oldfid->qid;
 903
 904         return fid;
 905
 906 clunk_fid:
 907         p9_client_clunk(fid);
 908         fid = NULL;
 909
 910 error:
 911         if (fid && (fid != oldfid))
 912                 p9_fid_destroy(fid);
 913
 914         return ERR_PTR(err);
 915 }
 916 EXPORT_SYMBOL(p9_client_walk);
 917
 918 int p9_client_open(struct p9_fid *fid, int mode)
 919 {
 920         int err;
 921         struct p9_client *clnt;
 922         struct p9_req_t *req;
 923         struct p9_qid qid;
 924         int iounit;
 925
 926         P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
 927         err = 0;
 928         clnt = fid->clnt;
 929
 930         if (fid->mode != -1)
 931                 return -EINVAL;
 932
 933         req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
 934         if (IS_ERR(req)) {
 935                 err = PTR_ERR(req);
 936                 goto error;
 937         }
 938
 939         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 940         if (err) {
 941                 p9pdu_dump(1, req->rc);
 942                 goto free_and_error;
 943         }
 944
 945         P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
 946                                 qid.type,
 947                                 (unsigned long long)qid.path,
 948                                 qid.version, iounit);
 949
 950         fid->mode = mode;
 951         fid->iounit = iounit;
 952
 953 free_and_error:
 954         p9_free_req(clnt, req);
 955 error:
 956         return err;
 957 }
 958 EXPORT_SYMBOL(p9_client_open);
 959
 960 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 961                      char *extension)
 962 {
 963         int err;
 964         struct p9_client *clnt;
 965         struct p9_req_t *req;
 966         struct p9_qid qid;
 967         int iounit;
 968
 969         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
 970                                                 fid->fid, name, perm, mode);
 971         err = 0;
 972         clnt = fid->clnt;
 973
 974         if (fid->mode != -1)
 975                 return -EINVAL;
 976
 977         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
 978                                 mode, extension);
 979         if (IS_ERR(req)) {
 980                 err = PTR_ERR(req);
 981                 goto error;
 982         }
 983
 984         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 985         if (err) {
 986                 p9pdu_dump(1, req->rc);
 987                 goto free_and_error;
 988         }
 989
 990         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
 991                                 qid.type,
 992                                 (unsigned long long)qid.path,
 993                                 qid.version, iounit);
 994
 995         fid->mode = mode;
 996         fid->iounit = iounit;
 997
 998 free_and_error:
 999         p9_free_req(clnt, req);
1000 error:
1001         return err;
1002 }
1003 EXPORT_SYMBOL(p9_client_fcreate);
1004
1005 int p9_client_clunk(struct p9_fid *fid)
1006 {
1007         int err;
1008         struct p9_client *clnt;
1009         struct p9_req_t *req;
1010
1011         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1012         err = 0;
1013         clnt = fid->clnt;
1014
1015         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1016         if (IS_ERR(req)) {
1017                 err = PTR_ERR(req);
1018                 goto error;
1019         }
1020
1021         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1022
1023         p9_free_req(clnt, req);
1024         p9_fid_destroy(fid);
1025
1026 error:
1027         return err;
1028 }
1029 EXPORT_SYMBOL(p9_client_clunk);
1030
1031 int p9_client_remove(struct p9_fid *fid)
1032 {
1033         int err;
1034         struct p9_client *clnt;
1035         struct p9_req_t *req;
1036
1037         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1038         err = 0;
1039         clnt = fid->clnt;
1040
1041         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1042         if (IS_ERR(req)) {
1043                 err = PTR_ERR(req);
1044                 goto error;
1045         }
1046
1047         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1048
1049         p9_free_req(clnt, req);
1050         p9_fid_destroy(fid);
1051
1052 error:
1053         return err;
1054 }
1055 EXPORT_SYMBOL(p9_client_remove);
1056
1057 int
1058 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1059                                                                 u32 count)
1060 {
1061         int err, rsize, total;
1062         struct p9_client *clnt;
1063         struct p9_req_t *req;
1064         char *dataptr;
1065
1066         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1067                                         (long long unsigned) offset, count);
1068         err = 0;
1069         clnt = fid->clnt;
1070         total = 0;
1071
1072         rsize = fid->iounit;
1073         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1074                 rsize = clnt->msize - P9_IOHDRSZ;
1075
1076         if (count < rsize)
1077                 rsize = count;
1078
1079         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1080         if (IS_ERR(req)) {
1081                 err = PTR_ERR(req);
1082                 goto error;
1083         }
1084
1085         err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1086         if (err) {
1087                 p9pdu_dump(1, req->rc);
1088                 goto free_and_error;
1089         }
1090
1091         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1092
1093         if (data) {
1094                 memmove(data, dataptr, count);
1095         }
1096
1097         if (udata) {
1098                 err = copy_to_user(udata, dataptr, count);
1099                 if (err) {
1100                         err = -EFAULT;
1101                         goto free_and_error;
1102                 }
1103         }
1104
1105         p9_free_req(clnt, req);
1106         return count;
1107
1108 free_and_error:
1109         p9_free_req(clnt, req);
1110 error:
1111         return err;
1112 }
1113 EXPORT_SYMBOL(p9_client_read);
1114
1115 int
1116 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1117                                                         u64 offset, u32 count)
1118 {
1119         int err, rsize, total;
1120         struct p9_client *clnt;
1121         struct p9_req_t *req;
1122
1123         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1124                                 fid->fid, (long long unsigned) offset, count);
1125         err = 0;
1126         clnt = fid->clnt;
1127         total = 0;
1128
1129         rsize = fid->iounit;
1130         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1131                 rsize = clnt->msize - P9_IOHDRSZ;
1132
1133         if (count < rsize)
1134                 rsize = count;
1135         if (data)
1136                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1137                                                                 rsize, data);
1138         else
1139                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1140                                                                 rsize, udata);
1141         if (IS_ERR(req)) {
1142                 err = PTR_ERR(req);
1143                 goto error;
1144         }
1145
1146         err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1147         if (err) {
1148                 p9pdu_dump(1, req->rc);
1149                 goto free_and_error;
1150         }
1151
1152         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1153
1154         p9_free_req(clnt, req);
1155         return count;
1156
1157 free_and_error:
1158         p9_free_req(clnt, req);
1159 error:
1160         return err;
1161 }
1162 EXPORT_SYMBOL(p9_client_write);
1163
1164 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1165 {
1166         int err;
1167         struct p9_client *clnt;
1168         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1169         struct p9_req_t *req;
1170         u16 ignored;
1171
1172         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1173
1174         if (!ret)
1175                 return ERR_PTR(-ENOMEM);
1176
1177         err = 0;
1178         clnt = fid->clnt;
1179
1180         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1181         if (IS_ERR(req)) {
1182                 err = PTR_ERR(req);
1183                 goto error;
1184         }
1185
1186         err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1187         if (err) {
1188                 p9pdu_dump(1, req->rc);
1189                 p9_free_req(clnt, req);
1190                 goto error;
1191         }
1192
1193         P9_DPRINTK(P9_DEBUG_9P,
1194                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1195                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1196                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1197                 "<<<    uid=%d gid=%d n_muid=%d\n",
1198                 ret->size, ret->type, ret->dev, ret->qid.type,
1199                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1200                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1201                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1202                 ret->n_uid, ret->n_gid, ret->n_muid);
1203
1204         p9_free_req(clnt, req);
1205         return ret;
1206
1207 error:
1208         kfree(ret);
1209         return ERR_PTR(err);
1210 }
1211 EXPORT_SYMBOL(p9_client_stat);
1212
1213 static int p9_client_statsize(struct p9_wstat *wst, int optional)
1214 {
1215         int ret;
1216
1217         /* size[2] type[2] dev[4] qid[13] */
1218         /* mode[4] atime[4] mtime[4] length[8]*/
1219         /* name[s] uid[s] gid[s] muid[s] */
1220         ret = 2+2+4+13+4+4+4+8+2+2+2+2;
1221
1222         if (wst->name)
1223                 ret += strlen(wst->name);
1224         if (wst->uid)
1225                 ret += strlen(wst->uid);
1226         if (wst->gid)
1227                 ret += strlen(wst->gid);
1228         if (wst->muid)
1229                 ret += strlen(wst->muid);
1230
1231         if (optional) {
1232                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1233                 if (wst->extension)
1234                         ret += strlen(wst->extension);
1235         }
1236
1237         return ret;
1238 }
1239
1240 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1241 {
1242         int err;
1243         struct p9_req_t *req;
1244         struct p9_client *clnt;
1245
1246         err = 0;
1247         clnt = fid->clnt;
1248         wst->size = p9_client_statsize(wst, clnt->dotu);
1249         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1250         P9_DPRINTK(P9_DEBUG_9P,
1251                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1252                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1253                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1254                 "     uid=%d gid=%d n_muid=%d\n",
1255                 wst->size, wst->type, wst->dev, wst->qid.type,
1256                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1257                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1258                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1259                 wst->n_uid, wst->n_gid, wst->n_muid);
1260
1261         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size, 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);