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   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/fs.h>
  29 #include <linux/poll.h>
  30 #include <linux/idr.h>
  31 #include <linux/mutex.h>
  32 #include <linux/sched.h>
  33 #include <linux/uaccess.h>
  34 #include <net/9p/9p.h>
  35 #include <linux/parser.h>
  36 #include <net/9p/client.h>
  37 #include <net/9p/transport.h>
  38 #include "protocol.h"
  39
  40 /*
  41   * Client Option Parsing (code inspired by NFS code)
  42   *  - a little lazy - parse all client options
  43   */
  44
  45 enum {
  46         Opt_msize,
  47         Opt_trans,
  48         Opt_legacy,
  49         Opt_err,
  50 };
  51
  52 static const match_table_t tokens = {
  53         {Opt_msize, "msize=%u"},
  54         {Opt_legacy, "noextend"},
  55         {Opt_trans, "trans=%s"},
  56         {Opt_err, NULL},
  57 };
  58
  59 static struct p9_req_t *
  60 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
  61
  62 /**
  63  * v9fs_parse_options - parse mount options into session structure
  64  * @options: options string passed from mount
  65  * @v9ses: existing v9fs session information
  66  *
  67  * Return 0 upon success, -ERRNO upon failure
  68  */
  69
  70 static int parse_opts(char *opts, struct p9_client *clnt)
  71 {
  72         char *options;
  73         char *p;
  74         substring_t args[MAX_OPT_ARGS];
  75         int option;
  76         int ret = 0;
  77
  78         clnt->dotu = 1;
  79         clnt->msize = 8192;
  80
  81         if (!opts)
  82                 return 0;
  83
  84         options = kstrdup(opts, GFP_KERNEL);
  85         if (!options) {
  86                 P9_DPRINTK(P9_DEBUG_ERROR,
  87                                 "failed to allocate copy of option string\n");
  88                 return -ENOMEM;
  89         }
  90
  91         while ((p = strsep(&options, ",")) != NULL) {
  92                 int token;
  93                 if (!*p)
  94                         continue;
  95                 token = match_token(p, tokens, args);
  96                 if (token < Opt_trans) {
  97                         int r = match_int(&args[0], &option);
  98                         if (r < 0) {
  99                                 P9_DPRINTK(P9_DEBUG_ERROR,
 100                                         "integer field, but no integer?\n");
 101                                 ret = r;
 102                                 continue;
 103                         }
 104                 }
 105                 switch (token) {
 106                 case Opt_msize:
 107                         clnt->msize = option;
 108                         break;
 109                 case Opt_trans:
 110                         clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
 111                         break;
 112                 case Opt_legacy:
 113                         clnt->dotu = 0;
 114                         break;
 115                 default:
 116                         continue;
 117                 }
 118         }
 119
 120         if (!clnt->trans_mod)
 121                 clnt->trans_mod = v9fs_get_default_trans();
 122
 123         kfree(options);
 124         return ret;
 125 }
 126
 127 /**
 128  * p9_tag_alloc - lookup/allocate a request by tag
 129  * @c: client session to lookup tag within
 130  * @tag: numeric id for transaction
 131  *
 132  * this is a simple array lookup, but will grow the
 133  * request_slots as necessary to accomodate transaction
 134  * ids which did not previously have a slot.
 135  *
 136  * this code relies on the client spinlock to manage locks, its
 137  * possible we should switch to something else, but I'd rather
 138  * stick with something low-overhead for the common case.
 139  *
 140  */
 141
 142 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
 143 {
 144         unsigned long flags;
 145         int row, col;
 146         struct p9_req_t *req;
 147
 148         /* This looks up the original request by tag so we know which
 149          * buffer to read the data into */
 150         tag++;
 151
 152         if (tag >= c->max_tag) {
 153                 spin_lock_irqsave(&c->lock, flags);
 154                 /* check again since original check was outside of lock */
 155                 while (tag >= c->max_tag) {
 156                         row = (tag / P9_ROW_MAXTAG);
 157                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 158                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 159
 160                         if (!c->reqs[row]) {
 161                                 printk(KERN_ERR "Couldn't grow tag array\n");
 162                                 spin_unlock_irqrestore(&c->lock, flags);
 163                                 return ERR_PTR(-ENOMEM);
 164                         }
 165                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 166                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 167                                 c->reqs[row][col].tc = NULL;
 168                         }
 169                         c->max_tag += P9_ROW_MAXTAG;
 170                 }
 171                 spin_unlock_irqrestore(&c->lock, flags);
 172         }
 173         row = tag / P9_ROW_MAXTAG;
 174         col = tag % P9_ROW_MAXTAG;
 175
 176         req = &c->reqs[row][col];
 177         if (!req->tc) {
 178                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
 179                 if (!req->wq) {
 180                         printk(KERN_ERR "Couldn't grow tag array\n");
 181                         return ERR_PTR(-ENOMEM);
 182                 }
 183                 init_waitqueue_head(req->wq);
 184                 req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 185                                                                 GFP_KERNEL);
 186                 req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 187                                                                 GFP_KERNEL);
 188                 if ((!req->tc) || (!req->rc)) {
 189                         printk(KERN_ERR "Couldn't grow tag array\n");
 190                         kfree(req->tc);
 191                         kfree(req->rc);
 192                         kfree(req->wq);
 193                         req->tc = req->rc = NULL;
 194                         req->wq = NULL;
 195                         return ERR_PTR(-ENOMEM);
 196                 }
 197                 req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
 198                 req->tc->capacity = c->msize;
 199                 req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
 200                 req->rc->capacity = c->msize;
 201         }
 202
 203         p9pdu_reset(req->tc);
 204         p9pdu_reset(req->rc);
 205
 206         req->tc->tag = tag-1;
 207         req->status = REQ_STATUS_ALLOC;
 208
 209         return &c->reqs[row][col];
 210 }
 211
 212 /**
 213  * p9_tag_lookup - lookup a request by tag
 214  * @c: client session to lookup tag within
 215  * @tag: numeric id for transaction
 216  *
 217  */
 218
 219 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 220 {
 221         int row, col;
 222
 223         /* This looks up the original request by tag so we know which
 224          * buffer to read the data into */
 225         tag++;
 226
 227         BUG_ON(tag >= c->max_tag);
 228
 229         row = tag / P9_ROW_MAXTAG;
 230         col = tag % P9_ROW_MAXTAG;
 231
 232         return &c->reqs[row][col];
 233 }
 234 EXPORT_SYMBOL(p9_tag_lookup);
 235
 236 /**
 237  * p9_tag_init - setup tags structure and contents
 238  * @tags: tags structure from the client struct
 239  *
 240  * This initializes the tags structure for each client instance.
 241  *
 242  */
 243
 244 static int p9_tag_init(struct p9_client *c)
 245 {
 246         int err = 0;
 247
 248         c->tagpool = p9_idpool_create();
 249         if (IS_ERR(c->tagpool)) {
 250                 err = PTR_ERR(c->tagpool);
 251                 c->tagpool = NULL;
 252                 goto error;
 253         }
 254
 255         p9_idpool_get(c->tagpool); /* reserve tag 0 */
 256
 257         c->max_tag = 0;
 258 error:
 259         return err;
 260 }
 261
 262 /**
 263  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 264  * @tags: tags structure from the client struct
 265  *
 266  * This frees resources associated with the tags structure
 267  *
 268  */
 269 static void p9_tag_cleanup(struct p9_client *c)
 270 {
 271         int row, col;
 272
 273         /* check to insure all requests are idle */
 274         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 275                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 276                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 277                                 P9_DPRINTK(P9_DEBUG_MUX,
 278                                   "Attempting to cleanup non-free tag %d,%d\n",
 279                                   row, col);
 280                                 /* TODO: delay execution of cleanup */
 281                                 return;
 282                         }
 283                 }
 284         }
 285
 286         if (c->tagpool)
 287                 p9_idpool_destroy(c->tagpool);
 288
 289         /* free requests associated with tags */
 290         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 291                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 292                         kfree(c->reqs[row][col].wq);
 293                         kfree(c->reqs[row][col].tc);
 294                         kfree(c->reqs[row][col].rc);
 295                 }
 296                 kfree(c->reqs[row]);
 297         }
 298         c->max_tag = 0;
 299 }
 300
 301 /**
 302  * p9_free_req - free a request and clean-up as necessary
 303  * c: client state
 304  * r: request to release
 305  *
 306  */
 307
 308 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 309 {
 310         int tag = r->tc->tag;
 311         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 312
 313         r->status = REQ_STATUS_IDLE;
 314         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 315                 p9_idpool_put(tag, c->tagpool);
 316 }
 317
 318 /**
 319  * p9_client_cb - call back from transport to client
 320  * c: client state
 321  * req: request received
 322  *
 323  */
 324 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
 325 {
 326         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 327         wake_up(req->wq);
 328         P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 329 }
 330 EXPORT_SYMBOL(p9_client_cb);
 331
 332 /**
 333  * p9_parse_header - parse header arguments out of a packet
 334  * @pdu: packet to parse
 335  * @size: size of packet
 336  * @type: type of request
 337  * @tag: tag of packet
 338  * @rewind: set if we need to rewind offset afterwards
 339  */
 340
 341 int
 342 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 343                                                                 int rewind)
 344 {
 345         int8_t r_type;
 346         int16_t r_tag;
 347         int32_t r_size;
 348         int offset = pdu->offset;
 349         int err;
 350
 351         pdu->offset = 0;
 352         if (pdu->size == 0)
 353                 pdu->size = 7;
 354
 355         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 356         if (err)
 357                 goto rewind_and_exit;
 358
 359         pdu->size = r_size;
 360         pdu->id = r_type;
 361         pdu->tag = r_tag;
 362
 363         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
 364                                                         pdu->id, pdu->tag);
 365
 366         if (type)
 367                 *type = r_type;
 368         if (tag)
 369                 *tag = r_tag;
 370         if (size)
 371                 *size = r_size;
 372
 373
 374 rewind_and_exit:
 375         if (rewind)
 376                 pdu->offset = offset;
 377         return err;
 378 }
 379 EXPORT_SYMBOL(p9_parse_header);
 380
 381 /**
 382  * p9_check_errors - check 9p packet for error return and process it
 383  * @c: current client instance
 384  * @req: request to parse and check for error conditions
 385  *
 386  * returns error code if one is discovered, otherwise returns 0
 387  *
 388  * this will have to be more complicated if we have multiple
 389  * error packet types
 390  */
 391
 392 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 393 {
 394         int8_t type;
 395         int err;
 396
 397         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 398         if (err) {
 399                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 400                 return err;
 401         }
 402
 403         if (type == P9_RERROR) {
 404                 int ecode;
 405                 char *ename;
 406
 407                 err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
 408                 if (err) {
 409                         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
 410                                                                         err);
 411                         return err;
 412                 }
 413
 414                 if (c->dotu)
 415                         err = -ecode;
 416
 417                 if (!err) {
 418                         err = p9_errstr2errno(ename, strlen(ename));
 419
 420                         /* string match failed */
 421                         if (!err)
 422                                 err = -ESERVERFAULT;
 423                 }
 424
 425                 P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
 426
 427                 kfree(ename);
 428         } else
 429                 err = 0;
 430
 431         return err;
 432 }
 433
 434 /**
 435  * p9_client_flush - flush (cancel) a request
 436  * c: client state
 437  * req: request to cancel
 438  *
 439  * This sents a flush for a particular requests and links
 440  * the flush request to the original request.  The current
 441  * code only supports a single flush request although the protocol
 442  * allows for multiple flush requests to be sent for a single request.
 443  *
 444  */
 445
 446 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 447 {
 448         struct p9_req_t *req;
 449         int16_t oldtag;
 450         int err;
 451
 452         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 453         if (err)
 454                 return err;
 455
 456         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 457
 458         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 459         if (IS_ERR(req))
 460                 return PTR_ERR(req);
 461
 462
 463         /* if we haven't received a response for oldreq,
 464            remove it from the list. */
 465         spin_lock(&c->lock);
 466         if (oldreq->status == REQ_STATUS_FLSH)
 467                 list_del(&oldreq->req_list);
 468         spin_unlock(&c->lock);
 469
 470         p9_free_req(c, req);
 471         return 0;
 472 }
 473
 474 /**
 475  * p9_client_rpc - issue a request and wait for a response
 476  * @c: client session
 477  * @type: type of request
 478  * @fmt: protocol format string (see protocol.c)
 479  *
 480  * Returns request structure (which client must free using p9_free_req)
 481  */
 482
 483 static struct p9_req_t *
 484 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 485 {
 486         va_list ap;
 487         int tag, err;
 488         struct p9_req_t *req;
 489         unsigned long flags;
 490         int sigpending;
 491
 492         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 493
 494         if (c->status != Connected)
 495                 return ERR_PTR(-EIO);
 496
 497         if (signal_pending(current)) {
 498                 sigpending = 1;
 499                 clear_thread_flag(TIF_SIGPENDING);
 500         } else
 501                 sigpending = 0;
 502
 503         tag = P9_NOTAG;
 504         if (type != P9_TVERSION) {
 505                 tag = p9_idpool_get(c->tagpool);
 506                 if (tag < 0)
 507                         return ERR_PTR(-ENOMEM);
 508         }
 509
 510         req = p9_tag_alloc(c, tag);
 511         if (IS_ERR(req))
 512                 return req;
 513
 514         /* marshall the data */
 515         p9pdu_prepare(req->tc, tag, type);
 516         va_start(ap, fmt);
 517         err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
 518         va_end(ap);
 519         p9pdu_finalize(req->tc);
 520
 521         err = c->trans_mod->request(c, req);
 522         if (err < 0) {
 523                 c->status = Disconnected;
 524                 goto reterr;
 525         }
 526
 527         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
 528         err = wait_event_interruptible(*req->wq,
 529                                                 req->status >= REQ_STATUS_RCVD);
 530         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
 531                                                 req->wq, tag, err);
 532
 533         if (req->status == REQ_STATUS_ERROR) {
 534                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 535                 err = req->t_err;
 536         }
 537
 538         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 539                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
 540                 sigpending = 1;
 541                 clear_thread_flag(TIF_SIGPENDING);
 542
 543                 if (c->trans_mod->cancel(c, req))
 544                         p9_client_flush(c, req);
 545
 546                 /* if we received the response anyway, don't signal error */
 547                 if (req->status == REQ_STATUS_RCVD)
 548                         err = 0;
 549         }
 550
 551         if (sigpending) {
 552                 spin_lock_irqsave(&current->sighand->siglock, flags);
 553                 recalc_sigpending();
 554                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 555         }
 556
 557         if (err < 0)
 558                 goto reterr;
 559
 560         err = p9_check_errors(c, req);
 561         if (!err) {
 562                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
 563                 return req;
 564         }
 565
 566 reterr:
 567         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
 568                                                                         err);
 569         p9_free_req(c, req);
 570         return ERR_PTR(err);
 571 }
 572
 573 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 574 {
 575         int ret;
 576         struct p9_fid *fid;
 577         unsigned long flags;
 578
 579         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
 580         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 581         if (!fid)
 582                 return ERR_PTR(-ENOMEM);
 583
 584         ret = p9_idpool_get(clnt->fidpool);
 585         if (ret < 0) {
 586                 ret = -ENOSPC;
 587                 goto error;
 588         }
 589         fid->fid = ret;
 590
 591         memset(&fid->qid, 0, sizeof(struct p9_qid));
 592         fid->mode = -1;
 593         fid->rdir_fpos = 0;
 594         fid->uid = current_fsuid();
 595         fid->clnt = clnt;
 596         fid->aux = NULL;
 597
 598         spin_lock_irqsave(&clnt->lock, flags);
 599         list_add(&fid->flist, &clnt->fidlist);
 600         spin_unlock_irqrestore(&clnt->lock, flags);
 601
 602         return fid;
 603
 604 error:
 605         kfree(fid);
 606         return ERR_PTR(ret);
 607 }
 608
 609 static void p9_fid_destroy(struct p9_fid *fid)
 610 {
 611         struct p9_client *clnt;
 612         unsigned long flags;
 613
 614         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
 615         clnt = fid->clnt;
 616         p9_idpool_put(fid->fid, clnt->fidpool);
 617         spin_lock_irqsave(&clnt->lock, flags);
 618         list_del(&fid->flist);
 619         spin_unlock_irqrestore(&clnt->lock, flags);
 620         kfree(fid);
 621 }
 622
 623 int p9_client_version(struct p9_client *c)
 624 {
 625         int err = 0;
 626         struct p9_req_t *req;
 627         char *version;
 628         int msize;
 629
 630         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
 631                                                         c->msize, c->dotu);
 632         req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
 633                                 c->dotu ? "9P2000.u" : "9P2000");
 634         if (IS_ERR(req))
 635                 return PTR_ERR(req);
 636
 637         err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
 638         if (err) {
 639                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
 640                 p9pdu_dump(1, req->rc);
 641                 goto error;
 642         }
 643
 644         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 645         if (!memcmp(version, "9P2000.u", 8))
 646                 c->dotu = 1;
 647         else if (!memcmp(version, "9P2000", 6))
 648                 c->dotu = 0;
 649         else {
 650                 err = -EREMOTEIO;
 651                 goto error;
 652         }
 653
 654         if (msize < c->msize)
 655                 c->msize = msize;
 656
 657 error:
 658         kfree(version);
 659         p9_free_req(c, req);
 660
 661         return err;
 662 }
 663 EXPORT_SYMBOL(p9_client_version);
 664
 665 struct p9_client *p9_client_create(const char *dev_name, char *options)
 666 {
 667         int err;
 668         struct p9_client *clnt;
 669
 670         err = 0;
 671         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 672         if (!clnt)
 673                 return ERR_PTR(-ENOMEM);
 674
 675         clnt->trans_mod = NULL;
 676         clnt->trans = NULL;
 677         spin_lock_init(&clnt->lock);
 678         INIT_LIST_HEAD(&clnt->fidlist);
 679         clnt->fidpool = p9_idpool_create();
 680         if (IS_ERR(clnt->fidpool)) {
 681                 err = PTR_ERR(clnt->fidpool);
 682                 clnt->fidpool = NULL;
 683                 goto error;
 684         }
 685
 686         p9_tag_init(clnt);
 687
 688         err = parse_opts(options, clnt);
 689         if (err < 0)
 690                 goto error;
 691
 692         if (clnt->trans_mod == NULL) {
 693                 err = -EPROTONOSUPPORT;
 694                 P9_DPRINTK(P9_DEBUG_ERROR,
 695                                 "No transport defined or default transport\n");
 696                 goto error;
 697         }
 698
 699         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
 700                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 701
 702         err = clnt->trans_mod->create(clnt, dev_name, options);
 703         if (err)
 704                 goto error;
 705
 706         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 707                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 708
 709         err = p9_client_version(clnt);
 710         if (err)
 711                 goto error;
 712
 713         return clnt;
 714
 715 error:
 716         p9_client_destroy(clnt);
 717         return ERR_PTR(err);
 718 }
 719 EXPORT_SYMBOL(p9_client_create);
 720
 721 void p9_client_destroy(struct p9_client *clnt)
 722 {
 723         struct p9_fid *fid, *fidptr;
 724
 725         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
 726
 727         if (clnt->trans_mod)
 728                 clnt->trans_mod->close(clnt);
 729
 730         v9fs_put_trans(clnt->trans_mod);
 731
 732         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 733                 p9_fid_destroy(fid);
 734
 735         if (clnt->fidpool)
 736                 p9_idpool_destroy(clnt->fidpool);
 737
 738         p9_tag_cleanup(clnt);
 739
 740         kfree(clnt);
 741 }
 742 EXPORT_SYMBOL(p9_client_destroy);
 743
 744 void p9_client_disconnect(struct p9_client *clnt)
 745 {
 746         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 747         clnt->status = Disconnected;
 748 }
 749 EXPORT_SYMBOL(p9_client_disconnect);
 750
 751 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 752         char *uname, u32 n_uname, char *aname)
 753 {
 754         int err;
 755         struct p9_req_t *req;
 756         struct p9_fid *fid;
 757         struct p9_qid qid;
 758
 759         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
 760                                         afid ? afid->fid : -1, uname, aname);
 761         err = 0;
 762
 763         fid = p9_fid_create(clnt);
 764         if (IS_ERR(fid)) {
 765                 err = PTR_ERR(fid);
 766                 fid = NULL;
 767                 goto error;
 768         }
 769
 770         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
 771                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 772         if (IS_ERR(req)) {
 773                 err = PTR_ERR(req);
 774                 goto error;
 775         }
 776
 777         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 778         if (err) {
 779                 p9pdu_dump(1, req->rc);
 780                 p9_free_req(clnt, req);
 781                 goto error;
 782         }
 783
 784         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
 785                                         qid.type,
 786                                         (unsigned long long)qid.path,
 787                                         qid.version);
 788
 789         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
 790
 791         p9_free_req(clnt, req);
 792         return fid;
 793
 794 error:
 795         if (fid)
 796                 p9_fid_destroy(fid);
 797         return ERR_PTR(err);
 798 }
 799 EXPORT_SYMBOL(p9_client_attach);
 800
 801 struct p9_fid *
 802 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
 803 {
 804         int err;
 805         struct p9_req_t *req;
 806         struct p9_qid qid;
 807         struct p9_fid *afid;
 808
 809         P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
 810         err = 0;
 811
 812         afid = p9_fid_create(clnt);
 813         if (IS_ERR(afid)) {
 814                 err = PTR_ERR(afid);
 815                 afid = NULL;
 816                 goto error;
 817         }
 818
 819         req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
 820                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 821         if (IS_ERR(req)) {
 822                 err = PTR_ERR(req);
 823                 goto error;
 824         }
 825
 826         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 827         if (err) {
 828                 p9pdu_dump(1, req->rc);
 829                 p9_free_req(clnt, req);
 830                 goto error;
 831         }
 832
 833         P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
 834                                         qid.type,
 835                                         (unsigned long long)qid.path,
 836                                         qid.version);
 837
 838         memmove(&afid->qid, &qid, sizeof(struct p9_qid));
 839         p9_free_req(clnt, req);
 840         return afid;
 841
 842 error:
 843         if (afid)
 844                 p9_fid_destroy(afid);
 845         return ERR_PTR(err);
 846 }
 847 EXPORT_SYMBOL(p9_client_auth);
 848
 849 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 850         int clone)
 851 {
 852         int err;
 853         struct p9_client *clnt;
 854         struct p9_fid *fid;
 855         struct p9_qid *wqids;
 856         struct p9_req_t *req;
 857         int16_t nwqids, count;
 858
 859         err = 0;
 860         clnt = oldfid->clnt;
 861         if (clone) {
 862                 fid = p9_fid_create(clnt);
 863                 if (IS_ERR(fid)) {
 864                         err = PTR_ERR(fid);
 865                         fid = NULL;
 866                         goto error;
 867                 }
 868
 869                 fid->uid = oldfid->uid;
 870         } else
 871                 fid = oldfid;
 872
 873
 874         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
 875                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
 876
 877         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
 878                                                                 nwname, wnames);
 879         if (IS_ERR(req)) {
 880                 err = PTR_ERR(req);
 881                 goto error;
 882         }
 883
 884         err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
 885         if (err) {
 886                 p9pdu_dump(1, req->rc);
 887                 p9_free_req(clnt, req);
 888                 goto clunk_fid;
 889         }
 890         p9_free_req(clnt, req);
 891
 892         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
 893
 894         if (nwqids != nwname) {
 895                 err = -ENOENT;
 896                 goto clunk_fid;
 897         }
 898
 899         for (count = 0; count < nwqids; count++)
 900                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
 901                         count, wqids[count].type,
 902                         (unsigned long long)wqids[count].path,
 903                         wqids[count].version);
 904
 905         if (nwname)
 906                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
 907         else
 908                 fid->qid = oldfid->qid;
 909
 910         return fid;
 911
 912 clunk_fid:
 913         p9_client_clunk(fid);
 914         fid = NULL;
 915
 916 error:
 917         if (fid && (fid != oldfid))
 918                 p9_fid_destroy(fid);
 919
 920         return ERR_PTR(err);
 921 }
 922 EXPORT_SYMBOL(p9_client_walk);
 923
 924 int p9_client_open(struct p9_fid *fid, int mode)
 925 {
 926         int err;
 927         struct p9_client *clnt;
 928         struct p9_req_t *req;
 929         struct p9_qid qid;
 930         int iounit;
 931
 932         P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
 933         err = 0;
 934         clnt = fid->clnt;
 935
 936         if (fid->mode != -1)
 937                 return -EINVAL;
 938
 939         req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
 940         if (IS_ERR(req)) {
 941                 err = PTR_ERR(req);
 942                 goto error;
 943         }
 944
 945         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 946         if (err) {
 947                 p9pdu_dump(1, req->rc);
 948                 goto free_and_error;
 949         }
 950
 951         P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
 952                                 qid.type,
 953                                 (unsigned long long)qid.path,
 954                                 qid.version, iounit);
 955
 956         fid->mode = mode;
 957         fid->iounit = iounit;
 958
 959 free_and_error:
 960         p9_free_req(clnt, req);
 961 error:
 962         return err;
 963 }
 964 EXPORT_SYMBOL(p9_client_open);
 965
 966 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 967                      char *extension)
 968 {
 969         int err;
 970         struct p9_client *clnt;
 971         struct p9_req_t *req;
 972         struct p9_qid qid;
 973         int iounit;
 974
 975         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
 976                                                 fid->fid, name, perm, mode);
 977         err = 0;
 978         clnt = fid->clnt;
 979
 980         if (fid->mode != -1)
 981                 return -EINVAL;
 982
 983         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
 984                                 mode, extension);
 985         if (IS_ERR(req)) {
 986                 err = PTR_ERR(req);
 987                 goto error;
 988         }
 989
 990         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 991         if (err) {
 992                 p9pdu_dump(1, req->rc);
 993                 goto free_and_error;
 994         }
 995
 996         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
 997                                 qid.type,
 998                                 (unsigned long long)qid.path,
 999                                 qid.version, iounit);
1000
1001         fid->mode = mode;
1002         fid->iounit = iounit;
1003
1004 free_and_error:
1005         p9_free_req(clnt, req);
1006 error:
1007         return err;
1008 }
1009 EXPORT_SYMBOL(p9_client_fcreate);
1010
1011 int p9_client_clunk(struct p9_fid *fid)
1012 {
1013         int err;
1014         struct p9_client *clnt;
1015         struct p9_req_t *req;
1016
1017         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1018         err = 0;
1019         clnt = fid->clnt;
1020
1021         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1022         if (IS_ERR(req)) {
1023                 err = PTR_ERR(req);
1024                 goto error;
1025         }
1026
1027         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1028
1029         p9_free_req(clnt, req);
1030         p9_fid_destroy(fid);
1031
1032 error:
1033         return err;
1034 }
1035 EXPORT_SYMBOL(p9_client_clunk);
1036
1037 int p9_client_remove(struct p9_fid *fid)
1038 {
1039         int err;
1040         struct p9_client *clnt;
1041         struct p9_req_t *req;
1042
1043         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1044         err = 0;
1045         clnt = fid->clnt;
1046
1047         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1048         if (IS_ERR(req)) {
1049                 err = PTR_ERR(req);
1050                 goto error;
1051         }
1052
1053         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1054
1055         p9_free_req(clnt, req);
1056         p9_fid_destroy(fid);
1057
1058 error:
1059         return err;
1060 }
1061 EXPORT_SYMBOL(p9_client_remove);
1062
1063 int
1064 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1065                                                                 u32 count)
1066 {
1067         int err, rsize, total;
1068         struct p9_client *clnt;
1069         struct p9_req_t *req;
1070         char *dataptr;
1071
1072         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1073                                         (long long unsigned) offset, count);
1074         err = 0;
1075         clnt = fid->clnt;
1076         total = 0;
1077
1078         rsize = fid->iounit;
1079         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1080                 rsize = clnt->msize - P9_IOHDRSZ;
1081
1082         if (count < rsize)
1083                 rsize = count;
1084
1085         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1086         if (IS_ERR(req)) {
1087                 err = PTR_ERR(req);
1088                 goto error;
1089         }
1090
1091         err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1092         if (err) {
1093                 p9pdu_dump(1, req->rc);
1094                 goto free_and_error;
1095         }
1096
1097         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1098
1099         if (data) {
1100                 memmove(data, dataptr, count);
1101                 data += count;
1102         }
1103
1104         if (udata) {
1105                 err = copy_to_user(udata, dataptr, count);
1106                 if (err) {
1107                         err = -EFAULT;
1108                         goto free_and_error;
1109                 }
1110         }
1111
1112         p9_free_req(clnt, req);
1113         return count;
1114
1115 free_and_error:
1116         p9_free_req(clnt, req);
1117 error:
1118         return err;
1119 }
1120 EXPORT_SYMBOL(p9_client_read);
1121
1122 int
1123 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1124                                                         u64 offset, u32 count)
1125 {
1126         int err, rsize, total;
1127         struct p9_client *clnt;
1128         struct p9_req_t *req;
1129
1130         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1131                                 fid->fid, (long long unsigned) offset, count);
1132         err = 0;
1133         clnt = fid->clnt;
1134         total = 0;
1135
1136         rsize = fid->iounit;
1137         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1138                 rsize = clnt->msize - P9_IOHDRSZ;
1139
1140         if (count < rsize)
1141                 rsize = count;
1142         if (data)
1143                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1144                                                                 rsize, data);
1145         else
1146                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1147                                                                 rsize, udata);
1148         if (IS_ERR(req)) {
1149                 err = PTR_ERR(req);
1150                 goto error;
1151         }
1152
1153         err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1154         if (err) {
1155                 p9pdu_dump(1, req->rc);
1156                 goto free_and_error;
1157         }
1158
1159         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1160
1161         p9_free_req(clnt, req);
1162         return count;
1163
1164 free_and_error:
1165         p9_free_req(clnt, req);
1166 error:
1167         return err;
1168 }
1169 EXPORT_SYMBOL(p9_client_write);
1170
1171 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1172 {
1173         int err;
1174         struct p9_client *clnt;
1175         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1176         struct p9_req_t *req;
1177         u16 ignored;
1178
1179         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1180
1181         if (!ret)
1182                 return ERR_PTR(-ENOMEM);
1183
1184         err = 0;
1185         clnt = fid->clnt;
1186
1187         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1188         if (IS_ERR(req)) {
1189                 err = PTR_ERR(req);
1190                 goto error;
1191         }
1192
1193         err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1194         if (err) {
1195                 ret = ERR_PTR(err);
1196                 p9pdu_dump(1, req->rc);
1197                 goto free_and_error;
1198         }
1199
1200         P9_DPRINTK(P9_DEBUG_9P,
1201                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1202                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1203                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1204                 "<<<    uid=%d gid=%d n_muid=%d\n",
1205                 ret->size, ret->type, ret->dev, ret->qid.type,
1206                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1207                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1208                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1209                 ret->n_uid, ret->n_gid, ret->n_muid);
1210
1211         p9_free_req(clnt, req);
1212         return ret;
1213
1214 free_and_error:
1215         p9_free_req(clnt, req);
1216 error:
1217         kfree(ret);
1218         return ERR_PTR(err);
1219 }
1220 EXPORT_SYMBOL(p9_client_stat);
1221
1222 static int p9_client_statsize(struct p9_wstat *wst, int optional)
1223 {
1224         int ret;
1225
1226         /* size[2] type[2] dev[4] qid[13] */
1227         /* mode[4] atime[4] mtime[4] length[8]*/
1228         /* name[s] uid[s] gid[s] muid[s] */
1229         ret = 2+2+4+13+4+4+4+8+2+2+2+2;
1230
1231         if (wst->name)
1232                 ret += strlen(wst->name);
1233         if (wst->uid)
1234                 ret += strlen(wst->uid);
1235         if (wst->gid)
1236                 ret += strlen(wst->gid);
1237         if (wst->muid)
1238                 ret += strlen(wst->muid);
1239
1240         if (optional) {
1241                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1242                 if (wst->extension)
1243                         ret += strlen(wst->extension);
1244         }
1245
1246         return ret;
1247 }
1248
1249 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1250 {
1251         int err;
1252         struct p9_req_t *req;
1253         struct p9_client *clnt;
1254
1255         err = 0;
1256         clnt = fid->clnt;
1257         wst->size = p9_client_statsize(wst, clnt->dotu);
1258         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1259         P9_DPRINTK(P9_DEBUG_9P,
1260                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1261                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1262                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1263                 "     uid=%d gid=%d n_muid=%d\n",
1264                 wst->size, wst->type, wst->dev, wst->qid.type,
1265                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1266                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1267                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1268                 wst->n_uid, wst->n_gid, wst->n_muid);
1269
1270         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size, wst);
1271         if (IS_ERR(req)) {
1272                 err = PTR_ERR(req);
1273                 goto error;
1274         }
1275
1276         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1277
1278         p9_free_req(clnt, req);
1279 error:
1280         return err;
1281 }
1282 EXPORT_SYMBOL(p9_client_wstat);