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, *tmp_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         tmp_options = kstrdup(opts, GFP_KERNEL);
  85         if (!tmp_options) {
  86                 P9_DPRINTK(P9_DEBUG_ERROR,
  87                                 "failed to allocate copy of option string\n");
  88                 return -ENOMEM;
  89         }
  90         options = tmp_options;
  91
  92         while ((p = strsep(&options, ",")) != NULL) {
  93                 int token;
  94                 if (!*p)
  95                         continue;
  96                 token = match_token(p, tokens, args);
  97                 if (token < Opt_trans) {
  98                         int r = match_int(&args[0], &option);
  99                         if (r < 0) {
 100                                 P9_DPRINTK(P9_DEBUG_ERROR,
 101                                         "integer field, but no integer?\n");
 102                                 ret = r;
 103                                 continue;
 104                         }
 105                 }
 106                 switch (token) {
 107                 case Opt_msize:
 108                         clnt->msize = option;
 109                         break;
 110                 case Opt_trans:
 111                         clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
 112                         if(clnt->trans_mod == NULL) {
 113                                 P9_DPRINTK(P9_DEBUG_ERROR,
 114                                    "Could not find request transport: %s\n",
 115                                    (char *) &args[0]);
 116                                 ret = -EINVAL;
 117                                 goto free_and_return;
 118                         }
 119                         break;
 120                 case Opt_legacy:
 121                         clnt->dotu = 0;
 122                         break;
 123                 default:
 124                         continue;
 125                 }
 126         }
 127
 128 free_and_return:
 129         kfree(tmp_options);
 130         return ret;
 131 }
 132
 133 /**
 134  * p9_tag_alloc - lookup/allocate a request by tag
 135  * @c: client session to lookup tag within
 136  * @tag: numeric id for transaction
 137  *
 138  * this is a simple array lookup, but will grow the
 139  * request_slots as necessary to accomodate transaction
 140  * ids which did not previously have a slot.
 141  *
 142  * this code relies on the client spinlock to manage locks, its
 143  * possible we should switch to something else, but I'd rather
 144  * stick with something low-overhead for the common case.
 145  *
 146  */
 147
 148 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
 149 {
 150         unsigned long flags;
 151         int row, col;
 152         struct p9_req_t *req;
 153
 154         /* This looks up the original request by tag so we know which
 155          * buffer to read the data into */
 156         tag++;
 157
 158         if (tag >= c->max_tag) {
 159                 spin_lock_irqsave(&c->lock, flags);
 160                 /* check again since original check was outside of lock */
 161                 while (tag >= c->max_tag) {
 162                         row = (tag / P9_ROW_MAXTAG);
 163                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 164                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 165
 166                         if (!c->reqs[row]) {
 167                                 printk(KERN_ERR "Couldn't grow tag array\n");
 168                                 spin_unlock_irqrestore(&c->lock, flags);
 169                                 return ERR_PTR(-ENOMEM);
 170                         }
 171                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 172                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 173                                 c->reqs[row][col].tc = NULL;
 174                         }
 175                         c->max_tag += P9_ROW_MAXTAG;
 176                 }
 177                 spin_unlock_irqrestore(&c->lock, flags);
 178         }
 179         row = tag / P9_ROW_MAXTAG;
 180         col = tag % P9_ROW_MAXTAG;
 181
 182         req = &c->reqs[row][col];
 183         if (!req->tc) {
 184                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
 185                 if (!req->wq) {
 186                         printk(KERN_ERR "Couldn't grow tag array\n");
 187                         return ERR_PTR(-ENOMEM);
 188                 }
 189                 init_waitqueue_head(req->wq);
 190                 req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 191                                                                 GFP_KERNEL);
 192                 req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 193                                                                 GFP_KERNEL);
 194                 if ((!req->tc) || (!req->rc)) {
 195                         printk(KERN_ERR "Couldn't grow tag array\n");
 196                         kfree(req->tc);
 197                         kfree(req->rc);
 198                         kfree(req->wq);
 199                         req->tc = req->rc = NULL;
 200                         req->wq = NULL;
 201                         return ERR_PTR(-ENOMEM);
 202                 }
 203                 req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
 204                 req->tc->capacity = c->msize;
 205                 req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
 206                 req->rc->capacity = c->msize;
 207         }
 208
 209         p9pdu_reset(req->tc);
 210         p9pdu_reset(req->rc);
 211
 212         req->tc->tag = tag-1;
 213         req->status = REQ_STATUS_ALLOC;
 214
 215         return &c->reqs[row][col];
 216 }
 217
 218 /**
 219  * p9_tag_lookup - lookup a request by tag
 220  * @c: client session to lookup tag within
 221  * @tag: numeric id for transaction
 222  *
 223  */
 224
 225 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 226 {
 227         int row, col;
 228
 229         /* This looks up the original request by tag so we know which
 230          * buffer to read the data into */
 231         tag++;
 232
 233         BUG_ON(tag >= c->max_tag);
 234
 235         row = tag / P9_ROW_MAXTAG;
 236         col = tag % P9_ROW_MAXTAG;
 237
 238         return &c->reqs[row][col];
 239 }
 240 EXPORT_SYMBOL(p9_tag_lookup);
 241
 242 /**
 243  * p9_tag_init - setup tags structure and contents
 244  * @c:  v9fs client struct
 245  *
 246  * This initializes the tags structure for each client instance.
 247  *
 248  */
 249
 250 static int p9_tag_init(struct p9_client *c)
 251 {
 252         int err = 0;
 253
 254         c->tagpool = p9_idpool_create();
 255         if (IS_ERR(c->tagpool)) {
 256                 err = PTR_ERR(c->tagpool);
 257                 c->tagpool = NULL;
 258                 goto error;
 259         }
 260
 261         p9_idpool_get(c->tagpool); /* reserve tag 0 */
 262
 263         c->max_tag = 0;
 264 error:
 265         return err;
 266 }
 267
 268 /**
 269  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 270  * @c:  v9fs client struct
 271  *
 272  * This frees resources associated with the tags structure
 273  *
 274  */
 275 static void p9_tag_cleanup(struct p9_client *c)
 276 {
 277         int row, col;
 278
 279         /* check to insure all requests are idle */
 280         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 281                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 282                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 283                                 P9_DPRINTK(P9_DEBUG_MUX,
 284                                   "Attempting to cleanup non-free tag %d,%d\n",
 285                                   row, col);
 286                                 /* TODO: delay execution of cleanup */
 287                                 return;
 288                         }
 289                 }
 290         }
 291
 292         if (c->tagpool)
 293                 p9_idpool_destroy(c->tagpool);
 294
 295         /* free requests associated with tags */
 296         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 297                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 298                         kfree(c->reqs[row][col].wq);
 299                         kfree(c->reqs[row][col].tc);
 300                         kfree(c->reqs[row][col].rc);
 301                 }
 302                 kfree(c->reqs[row]);
 303         }
 304         c->max_tag = 0;
 305 }
 306
 307 /**
 308  * p9_free_req - free a request and clean-up as necessary
 309  * c: client state
 310  * r: request to release
 311  *
 312  */
 313
 314 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 315 {
 316         int tag = r->tc->tag;
 317         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 318
 319         r->status = REQ_STATUS_IDLE;
 320         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 321                 p9_idpool_put(tag, c->tagpool);
 322 }
 323
 324 /**
 325  * p9_client_cb - call back from transport to client
 326  * c: client state
 327  * req: request received
 328  *
 329  */
 330 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
 331 {
 332         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 333         wake_up(req->wq);
 334         P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 335 }
 336 EXPORT_SYMBOL(p9_client_cb);
 337
 338 /**
 339  * p9_parse_header - parse header arguments out of a packet
 340  * @pdu: packet to parse
 341  * @size: size of packet
 342  * @type: type of request
 343  * @tag: tag of packet
 344  * @rewind: set if we need to rewind offset afterwards
 345  */
 346
 347 int
 348 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 349                                                                 int rewind)
 350 {
 351         int8_t r_type;
 352         int16_t r_tag;
 353         int32_t r_size;
 354         int offset = pdu->offset;
 355         int err;
 356
 357         pdu->offset = 0;
 358         if (pdu->size == 0)
 359                 pdu->size = 7;
 360
 361         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 362         if (err)
 363                 goto rewind_and_exit;
 364
 365         pdu->size = r_size;
 366         pdu->id = r_type;
 367         pdu->tag = r_tag;
 368
 369         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
 370                                                         pdu->id, pdu->tag);
 371
 372         if (type)
 373                 *type = r_type;
 374         if (tag)
 375                 *tag = r_tag;
 376         if (size)
 377                 *size = r_size;
 378
 379
 380 rewind_and_exit:
 381         if (rewind)
 382                 pdu->offset = offset;
 383         return err;
 384 }
 385 EXPORT_SYMBOL(p9_parse_header);
 386
 387 /**
 388  * p9_check_errors - check 9p packet for error return and process it
 389  * @c: current client instance
 390  * @req: request to parse and check for error conditions
 391  *
 392  * returns error code if one is discovered, otherwise returns 0
 393  *
 394  * this will have to be more complicated if we have multiple
 395  * error packet types
 396  */
 397
 398 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 399 {
 400         int8_t type;
 401         int err;
 402
 403         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 404         if (err) {
 405                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 406                 return err;
 407         }
 408
 409         if (type == P9_RERROR) {
 410                 int ecode;
 411                 char *ename;
 412
 413                 err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
 414                 if (err) {
 415                         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
 416                                                                         err);
 417                         return err;
 418                 }
 419
 420                 if (c->dotu)
 421                         err = -ecode;
 422
 423                 if (!err || !IS_ERR_VALUE(err))
 424                         err = p9_errstr2errno(ename, strlen(ename));
 425
 426                 P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
 427
 428                 kfree(ename);
 429         } else
 430                 err = 0;
 431
 432         return err;
 433 }
 434
 435 /**
 436  * p9_client_flush - flush (cancel) a request
 437  * @c: client state
 438  * @oldreq: request to cancel
 439  *
 440  * This sents a flush for a particular requests and links
 441  * the flush request to the original request.  The current
 442  * code only supports a single flush request although the protocol
 443  * allows for multiple flush requests to be sent for a single request.
 444  *
 445  */
 446
 447 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 448 {
 449         struct p9_req_t *req;
 450         int16_t oldtag;
 451         int err;
 452
 453         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 454         if (err)
 455                 return err;
 456
 457         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 458
 459         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 460         if (IS_ERR(req))
 461                 return PTR_ERR(req);
 462
 463
 464         /* if we haven't received a response for oldreq,
 465            remove it from the list. */
 466         spin_lock(&c->lock);
 467         if (oldreq->status == REQ_STATUS_FLSH)
 468                 list_del(&oldreq->req_list);
 469         spin_unlock(&c->lock);
 470
 471         p9_free_req(c, req);
 472         return 0;
 473 }
 474
 475 /**
 476  * p9_client_rpc - issue a request and wait for a response
 477  * @c: client session
 478  * @type: type of request
 479  * @fmt: protocol format string (see protocol.c)
 480  *
 481  * Returns request structure (which client must free using p9_free_req)
 482  */
 483
 484 static struct p9_req_t *
 485 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 486 {
 487         va_list ap;
 488         int tag, err;
 489         struct p9_req_t *req;
 490         unsigned long flags;
 491         int sigpending;
 492
 493         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 494
 495         if (c->status != Connected)
 496                 return ERR_PTR(-EIO);
 497
 498         if (signal_pending(current)) {
 499                 sigpending = 1;
 500                 clear_thread_flag(TIF_SIGPENDING);
 501         } else
 502                 sigpending = 0;
 503
 504         tag = P9_NOTAG;
 505         if (type != P9_TVERSION) {
 506                 tag = p9_idpool_get(c->tagpool);
 507                 if (tag < 0)
 508                         return ERR_PTR(-ENOMEM);
 509         }
 510
 511         req = p9_tag_alloc(c, tag);
 512         if (IS_ERR(req))
 513                 return req;
 514
 515         /* marshall the data */
 516         p9pdu_prepare(req->tc, tag, type);
 517         va_start(ap, fmt);
 518         err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
 519         va_end(ap);
 520         p9pdu_finalize(req->tc);
 521
 522         err = c->trans_mod->request(c, req);
 523         if (err < 0) {
 524                 c->status = Disconnected;
 525                 goto reterr;
 526         }
 527
 528         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
 529         err = wait_event_interruptible(*req->wq,
 530                                                 req->status >= REQ_STATUS_RCVD);
 531         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
 532                                                 req->wq, tag, err);
 533
 534         if (req->status == REQ_STATUS_ERROR) {
 535                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 536                 err = req->t_err;
 537         }
 538
 539         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 540                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
 541                 sigpending = 1;
 542                 clear_thread_flag(TIF_SIGPENDING);
 543
 544                 if (c->trans_mod->cancel(c, req))
 545                         p9_client_flush(c, req);
 546
 547                 /* if we received the response anyway, don't signal error */
 548                 if (req->status == REQ_STATUS_RCVD)
 549                         err = 0;
 550         }
 551
 552         if (sigpending) {
 553                 spin_lock_irqsave(&current->sighand->siglock, flags);
 554                 recalc_sigpending();
 555                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 556         }
 557
 558         if (err < 0)
 559                 goto reterr;
 560
 561         err = p9_check_errors(c, req);
 562         if (!err) {
 563                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
 564                 return req;
 565         }
 566
 567 reterr:
 568         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
 569                                                                         err);
 570         p9_free_req(c, req);
 571         return ERR_PTR(err);
 572 }
 573
 574 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 575 {
 576         int ret;
 577         struct p9_fid *fid;
 578         unsigned long flags;
 579
 580         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
 581         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 582         if (!fid)
 583                 return ERR_PTR(-ENOMEM);
 584
 585         ret = p9_idpool_get(clnt->fidpool);
 586         if (ret < 0) {
 587                 ret = -ENOSPC;
 588                 goto error;
 589         }
 590         fid->fid = ret;
 591
 592         memset(&fid->qid, 0, sizeof(struct p9_qid));
 593         fid->mode = -1;
 594         fid->uid = current_fsuid();
 595         fid->clnt = clnt;
 596         fid->rdir = NULL;
 597         spin_lock_irqsave(&clnt->lock, flags);
 598         list_add(&fid->flist, &clnt->fidlist);
 599         spin_unlock_irqrestore(&clnt->lock, flags);
 600
 601         return fid;
 602
 603 error:
 604         kfree(fid);
 605         return ERR_PTR(ret);
 606 }
 607
 608 static void p9_fid_destroy(struct p9_fid *fid)
 609 {
 610         struct p9_client *clnt;
 611         unsigned long flags;
 612
 613         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
 614         clnt = fid->clnt;
 615         p9_idpool_put(fid->fid, clnt->fidpool);
 616         spin_lock_irqsave(&clnt->lock, flags);
 617         list_del(&fid->flist);
 618         spin_unlock_irqrestore(&clnt->lock, flags);
 619         kfree(fid->rdir);
 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
 680         p9_tag_init(clnt);
 681
 682         err = parse_opts(options, clnt);
 683         if (err < 0)
 684                 goto free_client;
 685
 686         if (!clnt->trans_mod)
 687                 clnt->trans_mod = v9fs_get_default_trans();
 688
 689         if (clnt->trans_mod == NULL) {
 690                 err = -EPROTONOSUPPORT;
 691                 P9_DPRINTK(P9_DEBUG_ERROR,
 692                                 "No transport defined or default transport\n");
 693                 goto free_client;
 694         }
 695
 696         clnt->fidpool = p9_idpool_create();
 697         if (IS_ERR(clnt->fidpool)) {
 698                 err = PTR_ERR(clnt->fidpool);
 699                 clnt->fidpool = NULL;
 700                 goto put_trans;
 701         }
 702
 703         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
 704                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 705
 706         err = clnt->trans_mod->create(clnt, dev_name, options);
 707         if (err)
 708                 goto destroy_fidpool;
 709
 710         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 711                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 712
 713         err = p9_client_version(clnt);
 714         if (err)
 715                 goto close_trans;
 716
 717         return clnt;
 718
 719 close_trans:
 720         clnt->trans_mod->close(clnt);
 721 destroy_fidpool:
 722         p9_idpool_destroy(clnt->fidpool);
 723 put_trans:
 724         v9fs_put_trans(clnt->trans_mod);
 725 free_client:
 726         kfree(clnt);
 727         return ERR_PTR(err);
 728 }
 729 EXPORT_SYMBOL(p9_client_create);
 730
 731 void p9_client_destroy(struct p9_client *clnt)
 732 {
 733         struct p9_fid *fid, *fidptr;
 734
 735         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
 736
 737         if (clnt->trans_mod)
 738                 clnt->trans_mod->close(clnt);
 739
 740         v9fs_put_trans(clnt->trans_mod);
 741
 742         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 743                 p9_fid_destroy(fid);
 744
 745         if (clnt->fidpool)
 746                 p9_idpool_destroy(clnt->fidpool);
 747
 748         p9_tag_cleanup(clnt);
 749
 750         kfree(clnt);
 751 }
 752 EXPORT_SYMBOL(p9_client_destroy);
 753
 754 void p9_client_disconnect(struct p9_client *clnt)
 755 {
 756         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 757         clnt->status = Disconnected;
 758 }
 759 EXPORT_SYMBOL(p9_client_disconnect);
 760
 761 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 762         char *uname, u32 n_uname, char *aname)
 763 {
 764         int err;
 765         struct p9_req_t *req;
 766         struct p9_fid *fid;
 767         struct p9_qid qid;
 768
 769         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
 770                                         afid ? afid->fid : -1, uname, aname);
 771         err = 0;
 772
 773         fid = p9_fid_create(clnt);
 774         if (IS_ERR(fid)) {
 775                 err = PTR_ERR(fid);
 776                 fid = NULL;
 777                 goto error;
 778         }
 779
 780         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
 781                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 782         if (IS_ERR(req)) {
 783                 err = PTR_ERR(req);
 784                 goto error;
 785         }
 786
 787         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 788         if (err) {
 789                 p9pdu_dump(1, req->rc);
 790                 p9_free_req(clnt, req);
 791                 goto error;
 792         }
 793
 794         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
 795                                         qid.type,
 796                                         (unsigned long long)qid.path,
 797                                         qid.version);
 798
 799         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
 800
 801         p9_free_req(clnt, req);
 802         return fid;
 803
 804 error:
 805         if (fid)
 806                 p9_fid_destroy(fid);
 807         return ERR_PTR(err);
 808 }
 809 EXPORT_SYMBOL(p9_client_attach);
 810
 811 struct p9_fid *
 812 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
 813 {
 814         int err;
 815         struct p9_req_t *req;
 816         struct p9_qid qid;
 817         struct p9_fid *afid;
 818
 819         P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
 820         err = 0;
 821
 822         afid = p9_fid_create(clnt);
 823         if (IS_ERR(afid)) {
 824                 err = PTR_ERR(afid);
 825                 afid = NULL;
 826                 goto error;
 827         }
 828
 829         req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
 830                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 831         if (IS_ERR(req)) {
 832                 err = PTR_ERR(req);
 833                 goto error;
 834         }
 835
 836         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 837         if (err) {
 838                 p9pdu_dump(1, req->rc);
 839                 p9_free_req(clnt, req);
 840                 goto error;
 841         }
 842
 843         P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
 844                                         qid.type,
 845                                         (unsigned long long)qid.path,
 846                                         qid.version);
 847
 848         memmove(&afid->qid, &qid, sizeof(struct p9_qid));
 849         p9_free_req(clnt, req);
 850         return afid;
 851
 852 error:
 853         if (afid)
 854                 p9_fid_destroy(afid);
 855         return ERR_PTR(err);
 856 }
 857 EXPORT_SYMBOL(p9_client_auth);
 858
 859 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 860         int clone)
 861 {
 862         int err;
 863         struct p9_client *clnt;
 864         struct p9_fid *fid;
 865         struct p9_qid *wqids;
 866         struct p9_req_t *req;
 867         int16_t nwqids, count;
 868
 869         err = 0;
 870         clnt = oldfid->clnt;
 871         if (clone) {
 872                 fid = p9_fid_create(clnt);
 873                 if (IS_ERR(fid)) {
 874                         err = PTR_ERR(fid);
 875                         fid = NULL;
 876                         goto error;
 877                 }
 878
 879                 fid->uid = oldfid->uid;
 880         } else
 881                 fid = oldfid;
 882
 883
 884         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
 885                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
 886
 887         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
 888                                                                 nwname, wnames);
 889         if (IS_ERR(req)) {
 890                 err = PTR_ERR(req);
 891                 goto error;
 892         }
 893
 894         err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
 895         if (err) {
 896                 p9pdu_dump(1, req->rc);
 897                 p9_free_req(clnt, req);
 898                 goto clunk_fid;
 899         }
 900         p9_free_req(clnt, req);
 901
 902         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
 903
 904         if (nwqids != nwname) {
 905                 err = -ENOENT;
 906                 goto clunk_fid;
 907         }
 908
 909         for (count = 0; count < nwqids; count++)
 910                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
 911                         count, wqids[count].type,
 912                         (unsigned long long)wqids[count].path,
 913                         wqids[count].version);
 914
 915         if (nwname)
 916                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
 917         else
 918                 fid->qid = oldfid->qid;
 919
 920         return fid;
 921
 922 clunk_fid:
 923         p9_client_clunk(fid);
 924         fid = NULL;
 925
 926 error:
 927         if (fid && (fid != oldfid))
 928                 p9_fid_destroy(fid);
 929
 930         return ERR_PTR(err);
 931 }
 932 EXPORT_SYMBOL(p9_client_walk);
 933
 934 int p9_client_open(struct p9_fid *fid, int mode)
 935 {
 936         int err;
 937         struct p9_client *clnt;
 938         struct p9_req_t *req;
 939         struct p9_qid qid;
 940         int iounit;
 941
 942         P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
 943         err = 0;
 944         clnt = fid->clnt;
 945
 946         if (fid->mode != -1)
 947                 return -EINVAL;
 948
 949         req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
 950         if (IS_ERR(req)) {
 951                 err = PTR_ERR(req);
 952                 goto error;
 953         }
 954
 955         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 956         if (err) {
 957                 p9pdu_dump(1, req->rc);
 958                 goto free_and_error;
 959         }
 960
 961         P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
 962                                 qid.type,
 963                                 (unsigned long long)qid.path,
 964                                 qid.version, iounit);
 965
 966         fid->mode = mode;
 967         fid->iounit = iounit;
 968
 969 free_and_error:
 970         p9_free_req(clnt, req);
 971 error:
 972         return err;
 973 }
 974 EXPORT_SYMBOL(p9_client_open);
 975
 976 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 977                      char *extension)
 978 {
 979         int err;
 980         struct p9_client *clnt;
 981         struct p9_req_t *req;
 982         struct p9_qid qid;
 983         int iounit;
 984
 985         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
 986                                                 fid->fid, name, perm, mode);
 987         err = 0;
 988         clnt = fid->clnt;
 989
 990         if (fid->mode != -1)
 991                 return -EINVAL;
 992
 993         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
 994                                 mode, extension);
 995         if (IS_ERR(req)) {
 996                 err = PTR_ERR(req);
 997                 goto error;
 998         }
 999
1000         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
1001         if (err) {
1002                 p9pdu_dump(1, req->rc);
1003                 goto free_and_error;
1004         }
1005
1006         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1007                                 qid.type,
1008                                 (unsigned long long)qid.path,
1009                                 qid.version, iounit);
1010
1011         fid->mode = mode;
1012         fid->iounit = iounit;
1013
1014 free_and_error:
1015         p9_free_req(clnt, req);
1016 error:
1017         return err;
1018 }
1019 EXPORT_SYMBOL(p9_client_fcreate);
1020
1021 int p9_client_clunk(struct p9_fid *fid)
1022 {
1023         int err;
1024         struct p9_client *clnt;
1025         struct p9_req_t *req;
1026
1027         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1028         err = 0;
1029         clnt = fid->clnt;
1030
1031         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1032         if (IS_ERR(req)) {
1033                 err = PTR_ERR(req);
1034                 goto error;
1035         }
1036
1037         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1038
1039         p9_free_req(clnt, req);
1040         p9_fid_destroy(fid);
1041
1042 error:
1043         return err;
1044 }
1045 EXPORT_SYMBOL(p9_client_clunk);
1046
1047 int p9_client_remove(struct p9_fid *fid)
1048 {
1049         int err;
1050         struct p9_client *clnt;
1051         struct p9_req_t *req;
1052
1053         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1054         err = 0;
1055         clnt = fid->clnt;
1056
1057         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1058         if (IS_ERR(req)) {
1059                 err = PTR_ERR(req);
1060                 goto error;
1061         }
1062
1063         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1064
1065         p9_free_req(clnt, req);
1066         p9_fid_destroy(fid);
1067
1068 error:
1069         return err;
1070 }
1071 EXPORT_SYMBOL(p9_client_remove);
1072
1073 int
1074 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1075                                                                 u32 count)
1076 {
1077         int err, rsize, total;
1078         struct p9_client *clnt;
1079         struct p9_req_t *req;
1080         char *dataptr;
1081
1082         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1083                                         (long long unsigned) offset, count);
1084         err = 0;
1085         clnt = fid->clnt;
1086         total = 0;
1087
1088         rsize = fid->iounit;
1089         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1090                 rsize = clnt->msize - P9_IOHDRSZ;
1091
1092         if (count < rsize)
1093                 rsize = count;
1094
1095         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1096         if (IS_ERR(req)) {
1097                 err = PTR_ERR(req);
1098                 goto error;
1099         }
1100
1101         err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1102         if (err) {
1103                 p9pdu_dump(1, req->rc);
1104                 goto free_and_error;
1105         }
1106
1107         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1108
1109         if (data) {
1110                 memmove(data, dataptr, count);
1111         }
1112
1113         if (udata) {
1114                 err = copy_to_user(udata, dataptr, count);
1115                 if (err) {
1116                         err = -EFAULT;
1117                         goto free_and_error;
1118                 }
1119         }
1120
1121         p9_free_req(clnt, req);
1122         return count;
1123
1124 free_and_error:
1125         p9_free_req(clnt, req);
1126 error:
1127         return err;
1128 }
1129 EXPORT_SYMBOL(p9_client_read);
1130
1131 int
1132 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1133                                                         u64 offset, u32 count)
1134 {
1135         int err, rsize, total;
1136         struct p9_client *clnt;
1137         struct p9_req_t *req;
1138
1139         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1140                                 fid->fid, (long long unsigned) offset, count);
1141         err = 0;
1142         clnt = fid->clnt;
1143         total = 0;
1144
1145         rsize = fid->iounit;
1146         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1147                 rsize = clnt->msize - P9_IOHDRSZ;
1148
1149         if (count < rsize)
1150                 rsize = count;
1151         if (data)
1152                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1153                                                                 rsize, data);
1154         else
1155                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1156                                                                 rsize, udata);
1157         if (IS_ERR(req)) {
1158                 err = PTR_ERR(req);
1159                 goto error;
1160         }
1161
1162         err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1163         if (err) {
1164                 p9pdu_dump(1, req->rc);
1165                 goto free_and_error;
1166         }
1167
1168         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1169
1170         p9_free_req(clnt, req);
1171         return count;
1172
1173 free_and_error:
1174         p9_free_req(clnt, req);
1175 error:
1176         return err;
1177 }
1178 EXPORT_SYMBOL(p9_client_write);
1179
1180 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1181 {
1182         int err;
1183         struct p9_client *clnt;
1184         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1185         struct p9_req_t *req;
1186         u16 ignored;
1187
1188         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1189
1190         if (!ret)
1191                 return ERR_PTR(-ENOMEM);
1192
1193         err = 0;
1194         clnt = fid->clnt;
1195
1196         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1197         if (IS_ERR(req)) {
1198                 err = PTR_ERR(req);
1199                 goto error;
1200         }
1201
1202         err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1203         if (err) {
1204                 p9pdu_dump(1, req->rc);
1205                 p9_free_req(clnt, req);
1206                 goto error;
1207         }
1208
1209         P9_DPRINTK(P9_DEBUG_9P,
1210                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1211                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1212                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1213                 "<<<    uid=%d gid=%d n_muid=%d\n",
1214                 ret->size, ret->type, ret->dev, ret->qid.type,
1215                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1216                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1217                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1218                 ret->n_uid, ret->n_gid, ret->n_muid);
1219
1220         p9_free_req(clnt, req);
1221         return ret;
1222
1223 error:
1224         kfree(ret);
1225         return ERR_PTR(err);
1226 }
1227 EXPORT_SYMBOL(p9_client_stat);
1228
1229 static int p9_client_statsize(struct p9_wstat *wst, int optional)
1230 {
1231         int ret;
1232
1233         /* NOTE: size shouldn't include its own length */
1234         /* size[2] type[2] dev[4] qid[13] */
1235         /* mode[4] atime[4] mtime[4] length[8]*/
1236         /* name[s] uid[s] gid[s] muid[s] */
1237         ret = 2+4+13+4+4+4+8+2+2+2+2;
1238
1239         if (wst->name)
1240                 ret += strlen(wst->name);
1241         if (wst->uid)
1242                 ret += strlen(wst->uid);
1243         if (wst->gid)
1244                 ret += strlen(wst->gid);
1245         if (wst->muid)
1246                 ret += strlen(wst->muid);
1247
1248         if (optional) {
1249                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1250                 if (wst->extension)
1251                         ret += strlen(wst->extension);
1252         }
1253
1254         return ret;
1255 }
1256
1257 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1258 {
1259         int err;
1260         struct p9_req_t *req;
1261         struct p9_client *clnt;
1262
1263         err = 0;
1264         clnt = fid->clnt;
1265         wst->size = p9_client_statsize(wst, clnt->dotu);
1266         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1267         P9_DPRINTK(P9_DEBUG_9P,
1268                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1269                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1270                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1271                 "     uid=%d gid=%d n_muid=%d\n",
1272                 wst->size, wst->type, wst->dev, wst->qid.type,
1273                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1274                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1275                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1276                 wst->n_uid, wst->n_gid, wst->n_muid);
1277
1278         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1279         if (IS_ERR(req)) {
1280                 err = PTR_ERR(req);
1281                 goto error;
1282         }
1283
1284         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1285
1286         p9_free_req(clnt, req);
1287 error:
1288         return err;
1289 }
1290 EXPORT_SYMBOL(p9_client_wstat);