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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                         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->flush_tag = 0;
 204         req->tc->tag = tag-1;
 205         req->status = REQ_STATUS_ALLOC;
 206
 207         return &c->reqs[row][col];
 208 }
 209
 210 /**
 211  * p9_tag_lookup - lookup a request by tag
 212  * @c: client session to lookup tag within
 213  * @tag: numeric id for transaction
 214  *
 215  */
 216
 217 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 218 {
 219         int row, col;
 220
 221         /* This looks up the original request by tag so we know which
 222          * buffer to read the data into */
 223         tag++;
 224
 225         BUG_ON(tag >= c->max_tag);
 226
 227         row = tag / P9_ROW_MAXTAG;
 228         col = tag % P9_ROW_MAXTAG;
 229
 230         return &c->reqs[row][col];
 231 }
 232 EXPORT_SYMBOL(p9_tag_lookup);
 233
 234 /**
 235  * p9_tag_init - setup tags structure and contents
 236  * @tags: tags structure from the client struct
 237  *
 238  * This initializes the tags structure for each client instance.
 239  *
 240  */
 241
 242 static int p9_tag_init(struct p9_client *c)
 243 {
 244         int err = 0;
 245
 246         c->tagpool = p9_idpool_create();
 247         if (IS_ERR(c->tagpool)) {
 248                 err = PTR_ERR(c->tagpool);
 249                 c->tagpool = NULL;
 250                 goto error;
 251         }
 252
 253         p9_idpool_get(c->tagpool); /* reserve tag 0 */
 254
 255         c->max_tag = 0;
 256 error:
 257         return err;
 258 }
 259
 260 /**
 261  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 262  * @tags: tags structure from the client struct
 263  *
 264  * This frees resources associated with the tags structure
 265  *
 266  */
 267 static void p9_tag_cleanup(struct p9_client *c)
 268 {
 269         int row, col;
 270
 271         /* check to insure all requests are idle */
 272         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 273                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 274                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 275                                 P9_DPRINTK(P9_DEBUG_MUX,
 276                                   "Attempting to cleanup non-free tag %d,%d\n",
 277                                   row, col);
 278                                 /* TODO: delay execution of cleanup */
 279                                 return;
 280                         }
 281                 }
 282         }
 283
 284         if (c->tagpool)
 285                 p9_idpool_destroy(c->tagpool);
 286
 287         /* free requests associated with tags */
 288         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 289                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 290                         kfree(c->reqs[row][col].wq);
 291                         kfree(c->reqs[row][col].tc);
 292                         kfree(c->reqs[row][col].rc);
 293                 }
 294                 kfree(c->reqs[row]);
 295         }
 296         c->max_tag = 0;
 297 }
 298
 299 /**
 300  * p9_free_req - free a request and clean-up as necessary
 301  * c: client state
 302  * r: request to release
 303  *
 304  */
 305
 306 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 307 {
 308         int tag = r->tc->tag;
 309         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 310
 311         r->status = REQ_STATUS_IDLE;
 312         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 313                 p9_idpool_put(tag, c->tagpool);
 314
 315         /* if this was a flush request we have to free response fcall */
 316         if (r->rc->id == P9_RFLUSH) {
 317                 kfree(r->tc);
 318                 kfree(r->rc);
 319         }
 320 }
 321
 322 /**
 323  * p9_client_cb - call back from transport to client
 324  * c: client state
 325  * req: request received
 326  *
 327  */
 328 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
 329 {
 330         struct p9_req_t *other_req;
 331         unsigned long flags;
 332
 333         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 334
 335         if (req->status == REQ_STATUS_ERROR)
 336                 wake_up(req->wq);
 337
 338         if (req->flush_tag) {                   /* flush receive path */
 339                 P9_DPRINTK(P9_DEBUG_9P, "<<< RFLUSH %d\n", req->tc->tag);
 340                 spin_lock_irqsave(&c->lock, flags);
 341                 other_req = p9_tag_lookup(c, req->flush_tag);
 342                 if (other_req->status != REQ_STATUS_FLSH) /* stale flush */
 343                         spin_unlock_irqrestore(&c->lock, flags);
 344                 else {
 345                         other_req->status = REQ_STATUS_FLSHD;
 346                         spin_unlock_irqrestore(&c->lock, flags);
 347                         wake_up(other_req->wq);
 348                 }
 349                 p9_free_req(c, req);
 350         } else {                                /* normal receive path */
 351                 P9_DPRINTK(P9_DEBUG_MUX, "normal: tag %d\n", req->tc->tag);
 352                 spin_lock_irqsave(&c->lock, flags);
 353                 if (req->status != REQ_STATUS_FLSHD)
 354                         req->status = REQ_STATUS_RCVD;
 355                 spin_unlock_irqrestore(&c->lock, flags);
 356                 wake_up(req->wq);
 357                 P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 358         }
 359 }
 360 EXPORT_SYMBOL(p9_client_cb);
 361
 362 /**
 363  * p9_parse_header - parse header arguments out of a packet
 364  * @pdu: packet to parse
 365  * @size: size of packet
 366  * @type: type of request
 367  * @tag: tag of packet
 368  * @rewind: set if we need to rewind offset afterwards
 369  */
 370
 371 int
 372 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 373                                                                 int rewind)
 374 {
 375         int8_t r_type;
 376         int16_t r_tag;
 377         int32_t r_size;
 378         int offset = pdu->offset;
 379         int err;
 380
 381         pdu->offset = 0;
 382         if (pdu->size == 0)
 383                 pdu->size = 7;
 384
 385         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 386         if (err)
 387                 goto rewind_and_exit;
 388
 389         pdu->size = r_size;
 390         pdu->id = r_type;
 391         pdu->tag = r_tag;
 392
 393         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
 394                                                         pdu->id, pdu->tag);
 395
 396         if (type)
 397                 *type = r_type;
 398         if (tag)
 399                 *tag = r_tag;
 400         if (size)
 401                 *size = r_size;
 402
 403
 404 rewind_and_exit:
 405         if (rewind)
 406                 pdu->offset = offset;
 407         return err;
 408 }
 409 EXPORT_SYMBOL(p9_parse_header);
 410
 411 /**
 412  * p9_check_errors - check 9p packet for error return and process it
 413  * @c: current client instance
 414  * @req: request to parse and check for error conditions
 415  *
 416  * returns error code if one is discovered, otherwise returns 0
 417  *
 418  * this will have to be more complicated if we have multiple
 419  * error packet types
 420  */
 421
 422 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 423 {
 424         int8_t type;
 425         int err;
 426
 427         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 428         if (err) {
 429                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 430                 return err;
 431         }
 432
 433         if (type == P9_RERROR) {
 434                 int ecode;
 435                 char *ename;
 436
 437                 err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
 438                 if (err) {
 439                         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
 440                                                                         err);
 441                         return err;
 442                 }
 443
 444                 if (c->dotu)
 445                         err = -ecode;
 446
 447                 if (!err) {
 448                         err = p9_errstr2errno(ename, strlen(ename));
 449
 450                         /* string match failed */
 451                         if (!err)
 452                                 err = -ESERVERFAULT;
 453                 }
 454
 455                 P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
 456
 457                 kfree(ename);
 458         } else
 459                 err = 0;
 460
 461         return err;
 462 }
 463
 464 /**
 465  * p9_client_flush - flush (cancel) a request
 466  * c: client state
 467  * req: request to cancel
 468  *
 469  * This sents a flush for a particular requests and links
 470  * the flush request to the original request.  The current
 471  * code only supports a single flush request although the protocol
 472  * allows for multiple flush requests to be sent for a single request.
 473  *
 474  */
 475
 476 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 477 {
 478         struct p9_req_t *req;
 479         int16_t oldtag;
 480         int err;
 481
 482         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 483         if (err)
 484                 return err;
 485
 486         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 487
 488         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 489         if (IS_ERR(req))
 490                 return PTR_ERR(req);
 491
 492         req->flush_tag = oldtag;
 493
 494         /* we don't free anything here because RPC isn't complete */
 495         return 0;
 496 }
 497
 498 /**
 499  * p9_client_rpc - issue a request and wait for a response
 500  * @c: client session
 501  * @type: type of request
 502  * @fmt: protocol format string (see protocol.c)
 503  *
 504  * Returns request structure (which client must free using p9_free_req)
 505  */
 506
 507 static struct p9_req_t *
 508 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 509 {
 510         va_list ap;
 511         int tag, err;
 512         struct p9_req_t *req;
 513         unsigned long flags;
 514         int sigpending;
 515         int flushed = 0;
 516
 517         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 518
 519         if (c->status != Connected)
 520                 return ERR_PTR(-EIO);
 521
 522         if (signal_pending(current)) {
 523                 sigpending = 1;
 524                 clear_thread_flag(TIF_SIGPENDING);
 525         } else
 526                 sigpending = 0;
 527
 528         tag = P9_NOTAG;
 529         if (type != P9_TVERSION) {
 530                 tag = p9_idpool_get(c->tagpool);
 531                 if (tag < 0)
 532                         return ERR_PTR(-ENOMEM);
 533         }
 534
 535         req = p9_tag_alloc(c, tag);
 536         if (IS_ERR(req))
 537                 return req;
 538
 539         /* marshall the data */
 540         p9pdu_prepare(req->tc, tag, type);
 541         va_start(ap, fmt);
 542         err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
 543         va_end(ap);
 544         p9pdu_finalize(req->tc);
 545
 546         err = c->trans_mod->request(c, req);
 547         if (err < 0) {
 548                 c->status = Disconnected;
 549                 goto reterr;
 550         }
 551
 552         /* if it was a flush we just transmitted, return our tag */
 553         if (type == P9_TFLUSH)
 554                 return req;
 555 again:
 556         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
 557         err = wait_event_interruptible(*req->wq,
 558                                                 req->status >= REQ_STATUS_RCVD);
 559         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d (flushed=%d)\n",
 560                                                 req->wq, tag, err, flushed);
 561
 562         if (req->status == REQ_STATUS_ERROR) {
 563                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 564                 err = req->t_err;
 565         } else if (err == -ERESTARTSYS && flushed) {
 566                 P9_DPRINTK(P9_DEBUG_MUX, "flushed - going again\n");
 567                 goto again;
 568         } else if (req->status == REQ_STATUS_FLSHD) {
 569                 P9_DPRINTK(P9_DEBUG_MUX, "flushed - erestartsys\n");
 570                 err = -ERESTARTSYS;
 571         }
 572
 573         if ((err == -ERESTARTSYS) && (c->status == Connected) && (!flushed)) {
 574                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
 575                 spin_lock_irqsave(&c->lock, flags);
 576                 if (req->status == REQ_STATUS_SENT)
 577                         req->status = REQ_STATUS_FLSH;
 578                 spin_unlock_irqrestore(&c->lock, flags);
 579                 sigpending = 1;
 580                 flushed = 1;
 581                 clear_thread_flag(TIF_SIGPENDING);
 582
 583                 if (c->trans_mod->cancel(c, req)) {
 584                         err = p9_client_flush(c, req);
 585                         if (err == 0)
 586                                 goto again;
 587                 }
 588         }
 589
 590         if (sigpending) {
 591                 spin_lock_irqsave(&current->sighand->siglock, flags);
 592                 recalc_sigpending();
 593                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 594         }
 595
 596         if (err < 0)
 597                 goto reterr;
 598
 599         err = p9_check_errors(c, req);
 600         if (!err) {
 601                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
 602                 return req;
 603         }
 604
 605 reterr:
 606         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
 607                                                                         err);
 608         p9_free_req(c, req);
 609         return ERR_PTR(err);
 610 }
 611
 612 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 613 {
 614         int err;
 615         struct p9_fid *fid;
 616         unsigned long flags;
 617
 618         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
 619         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 620         if (!fid)
 621                 return ERR_PTR(-ENOMEM);
 622
 623         fid->fid = p9_idpool_get(clnt->fidpool);
 624         if (fid->fid < 0) {
 625                 err = -ENOSPC;
 626                 goto error;
 627         }
 628
 629         memset(&fid->qid, 0, sizeof(struct p9_qid));
 630         fid->mode = -1;
 631         fid->rdir_fpos = 0;
 632         fid->uid = current->fsuid;
 633         fid->clnt = clnt;
 634         fid->aux = NULL;
 635
 636         spin_lock_irqsave(&clnt->lock, flags);
 637         list_add(&fid->flist, &clnt->fidlist);
 638         spin_unlock_irqrestore(&clnt->lock, flags);
 639
 640         return fid;
 641
 642 error:
 643         kfree(fid);
 644         return ERR_PTR(err);
 645 }
 646
 647 static void p9_fid_destroy(struct p9_fid *fid)
 648 {
 649         struct p9_client *clnt;
 650         unsigned long flags;
 651
 652         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
 653         clnt = fid->clnt;
 654         p9_idpool_put(fid->fid, clnt->fidpool);
 655         spin_lock_irqsave(&clnt->lock, flags);
 656         list_del(&fid->flist);
 657         spin_unlock_irqrestore(&clnt->lock, flags);
 658         kfree(fid);
 659 }
 660
 661 int p9_client_version(struct p9_client *c)
 662 {
 663         int err = 0;
 664         struct p9_req_t *req;
 665         char *version;
 666         int msize;
 667
 668         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
 669                                                         c->msize, c->dotu);
 670         req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
 671                                 c->dotu ? "9P2000.u" : "9P2000");
 672         if (IS_ERR(req))
 673                 return PTR_ERR(req);
 674
 675         err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
 676         if (err) {
 677                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
 678                 p9pdu_dump(1, req->rc);
 679                 goto error;
 680         }
 681
 682         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 683         if (!memcmp(version, "9P2000.u", 8))
 684                 c->dotu = 1;
 685         else if (!memcmp(version, "9P2000", 6))
 686                 c->dotu = 0;
 687         else {
 688                 err = -EREMOTEIO;
 689                 goto error;
 690         }
 691
 692         if (msize < c->msize)
 693                 c->msize = msize;
 694
 695 error:
 696         kfree(version);
 697         p9_free_req(c, req);
 698
 699         return err;
 700 }
 701 EXPORT_SYMBOL(p9_client_version);
 702
 703 struct p9_client *p9_client_create(const char *dev_name, char *options)
 704 {
 705         int err;
 706         struct p9_client *clnt;
 707
 708         err = 0;
 709         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 710         if (!clnt)
 711                 return ERR_PTR(-ENOMEM);
 712
 713         clnt->trans_mod = NULL;
 714         clnt->trans = NULL;
 715         spin_lock_init(&clnt->lock);
 716         INIT_LIST_HEAD(&clnt->fidlist);
 717         clnt->fidpool = p9_idpool_create();
 718         if (IS_ERR(clnt->fidpool)) {
 719                 err = PTR_ERR(clnt->fidpool);
 720                 clnt->fidpool = NULL;
 721                 goto error;
 722         }
 723
 724         p9_tag_init(clnt);
 725
 726         err = parse_opts(options, clnt);
 727         if (err < 0)
 728                 goto error;
 729
 730         if (clnt->trans_mod == NULL) {
 731                 err = -EPROTONOSUPPORT;
 732                 P9_DPRINTK(P9_DEBUG_ERROR,
 733                                 "No transport defined or default transport\n");
 734                 goto error;
 735         }
 736
 737         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
 738                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 739
 740         err = clnt->trans_mod->create(clnt, dev_name, options);
 741         if (err)
 742                 goto error;
 743
 744         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 745                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 746
 747         err = p9_client_version(clnt);
 748         if (err)
 749                 goto error;
 750
 751         return clnt;
 752
 753 error:
 754         p9_client_destroy(clnt);
 755         return ERR_PTR(err);
 756 }
 757 EXPORT_SYMBOL(p9_client_create);
 758
 759 void p9_client_destroy(struct p9_client *clnt)
 760 {
 761         struct p9_fid *fid, *fidptr;
 762
 763         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
 764
 765         if (clnt->trans_mod)
 766                 clnt->trans_mod->close(clnt);
 767
 768         v9fs_put_trans(clnt->trans_mod);
 769
 770         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 771                 p9_fid_destroy(fid);
 772
 773         if (clnt->fidpool)
 774                 p9_idpool_destroy(clnt->fidpool);
 775
 776         p9_tag_cleanup(clnt);
 777
 778         kfree(clnt);
 779 }
 780 EXPORT_SYMBOL(p9_client_destroy);
 781
 782 void p9_client_disconnect(struct p9_client *clnt)
 783 {
 784         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 785         clnt->status = Disconnected;
 786 }
 787 EXPORT_SYMBOL(p9_client_disconnect);
 788
 789 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 790         char *uname, u32 n_uname, char *aname)
 791 {
 792         int err;
 793         struct p9_req_t *req;
 794         struct p9_fid *fid;
 795         struct p9_qid qid;
 796
 797         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
 798                                         afid ? afid->fid : -1, uname, aname);
 799         err = 0;
 800
 801         fid = p9_fid_create(clnt);
 802         if (IS_ERR(fid)) {
 803                 err = PTR_ERR(fid);
 804                 fid = NULL;
 805                 goto error;
 806         }
 807
 808         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
 809                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 810         if (IS_ERR(req)) {
 811                 err = PTR_ERR(req);
 812                 goto error;
 813         }
 814
 815         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 816         if (err) {
 817                 p9pdu_dump(1, req->rc);
 818                 p9_free_req(clnt, req);
 819                 goto error;
 820         }
 821
 822         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
 823                                         qid.type, qid.path, qid.version);
 824
 825         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
 826
 827         p9_free_req(clnt, req);
 828         return fid;
 829
 830 error:
 831         if (fid)
 832                 p9_fid_destroy(fid);
 833         return ERR_PTR(err);
 834 }
 835 EXPORT_SYMBOL(p9_client_attach);
 836
 837 struct p9_fid *
 838 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
 839 {
 840         int err;
 841         struct p9_req_t *req;
 842         struct p9_qid qid;
 843         struct p9_fid *afid;
 844
 845         P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
 846         err = 0;
 847
 848         afid = p9_fid_create(clnt);
 849         if (IS_ERR(afid)) {
 850                 err = PTR_ERR(afid);
 851                 afid = NULL;
 852                 goto error;
 853         }
 854
 855         req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
 856                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 857         if (IS_ERR(req)) {
 858                 err = PTR_ERR(req);
 859                 goto error;
 860         }
 861
 862         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 863         if (err) {
 864                 p9pdu_dump(1, req->rc);
 865                 p9_free_req(clnt, req);
 866                 goto error;
 867         }
 868
 869         P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
 870                                         qid.type, qid.path, qid.version);
 871
 872         memmove(&afid->qid, &qid, sizeof(struct p9_qid));
 873         p9_free_req(clnt, req);
 874         return afid;
 875
 876 error:
 877         if (afid)
 878                 p9_fid_destroy(afid);
 879         return ERR_PTR(err);
 880 }
 881 EXPORT_SYMBOL(p9_client_auth);
 882
 883 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 884         int clone)
 885 {
 886         int err;
 887         struct p9_client *clnt;
 888         struct p9_fid *fid;
 889         struct p9_qid *wqids;
 890         struct p9_req_t *req;
 891         int16_t nwqids, count;
 892
 893         err = 0;
 894         clnt = oldfid->clnt;
 895         if (clone) {
 896                 fid = p9_fid_create(clnt);
 897                 if (IS_ERR(fid)) {
 898                         err = PTR_ERR(fid);
 899                         fid = NULL;
 900                         goto error;
 901                 }
 902
 903                 fid->uid = oldfid->uid;
 904         } else
 905                 fid = oldfid;
 906
 907
 908         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
 909                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
 910
 911         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
 912                                                                 nwname, wnames);
 913         if (IS_ERR(req)) {
 914                 err = PTR_ERR(req);
 915                 goto error;
 916         }
 917
 918         err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
 919         if (err) {
 920                 p9pdu_dump(1, req->rc);
 921                 p9_free_req(clnt, req);
 922                 goto clunk_fid;
 923         }
 924         p9_free_req(clnt, req);
 925
 926         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
 927
 928         if (nwqids != nwname) {
 929                 err = -ENOENT;
 930                 goto clunk_fid;
 931         }
 932
 933         for (count = 0; count < nwqids; count++)
 934                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
 935                         count, wqids[count].type, wqids[count].path,
 936                         wqids[count].version);
 937
 938         if (nwname)
 939                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
 940         else
 941                 fid->qid = oldfid->qid;
 942
 943         return fid;
 944
 945 clunk_fid:
 946         p9_client_clunk(fid);
 947         fid = NULL;
 948
 949 error:
 950         if (fid && (fid != oldfid))
 951                 p9_fid_destroy(fid);
 952
 953         return ERR_PTR(err);
 954 }
 955 EXPORT_SYMBOL(p9_client_walk);
 956
 957 int p9_client_open(struct p9_fid *fid, int mode)
 958 {
 959         int err;
 960         struct p9_client *clnt;
 961         struct p9_req_t *req;
 962         struct p9_qid qid;
 963         int iounit;
 964
 965         P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
 966         err = 0;
 967         clnt = fid->clnt;
 968
 969         if (fid->mode != -1)
 970                 return -EINVAL;
 971
 972         req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
 973         if (IS_ERR(req)) {
 974                 err = PTR_ERR(req);
 975                 goto error;
 976         }
 977
 978         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 979         if (err) {
 980                 p9pdu_dump(1, req->rc);
 981                 goto free_and_error;
 982         }
 983
 984         P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
 985                                 qid.type, qid.path, qid.version, iounit);
 986
 987         fid->mode = mode;
 988         fid->iounit = iounit;
 989
 990 free_and_error:
 991         p9_free_req(clnt, req);
 992 error:
 993         return err;
 994 }
 995 EXPORT_SYMBOL(p9_client_open);
 996
 997 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 998                      char *extension)
 999 {
1000         int err;
1001         struct p9_client *clnt;
1002         struct p9_req_t *req;
1003         struct p9_qid qid;
1004         int iounit;
1005
1006         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1007                                                 fid->fid, name, perm, mode);
1008         err = 0;
1009         clnt = fid->clnt;
1010
1011         if (fid->mode != -1)
1012                 return -EINVAL;
1013
1014         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1015                                 mode, extension);
1016         if (IS_ERR(req)) {
1017                 err = PTR_ERR(req);
1018                 goto error;
1019         }
1020
1021         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
1022         if (err) {
1023                 p9pdu_dump(1, req->rc);
1024                 goto free_and_error;
1025         }
1026
1027         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1028                                 qid.type, qid.path, qid.version, iounit);
1029
1030         fid->mode = mode;
1031         fid->iounit = iounit;
1032
1033 free_and_error:
1034         p9_free_req(clnt, req);
1035 error:
1036         return err;
1037 }
1038 EXPORT_SYMBOL(p9_client_fcreate);
1039
1040 int p9_client_clunk(struct p9_fid *fid)
1041 {
1042         int err;
1043         struct p9_client *clnt;
1044         struct p9_req_t *req;
1045
1046         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1047         err = 0;
1048         clnt = fid->clnt;
1049
1050         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1051         if (IS_ERR(req)) {
1052                 err = PTR_ERR(req);
1053                 goto error;
1054         }
1055
1056         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1057
1058         p9_free_req(clnt, req);
1059         p9_fid_destroy(fid);
1060
1061 error:
1062         return err;
1063 }
1064 EXPORT_SYMBOL(p9_client_clunk);
1065
1066 int p9_client_remove(struct p9_fid *fid)
1067 {
1068         int err;
1069         struct p9_client *clnt;
1070         struct p9_req_t *req;
1071
1072         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1073         err = 0;
1074         clnt = fid->clnt;
1075
1076         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1077         if (IS_ERR(req)) {
1078                 err = PTR_ERR(req);
1079                 goto error;
1080         }
1081
1082         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1083
1084         p9_free_req(clnt, req);
1085         p9_fid_destroy(fid);
1086
1087 error:
1088         return err;
1089 }
1090 EXPORT_SYMBOL(p9_client_remove);
1091
1092 int
1093 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1094                                                                 u32 count)
1095 {
1096         int err, rsize, total;
1097         struct p9_client *clnt;
1098         struct p9_req_t *req;
1099         char *dataptr;
1100
1101         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1102                                         (long long unsigned) offset, count);
1103         err = 0;
1104         clnt = fid->clnt;
1105         total = 0;
1106
1107         rsize = fid->iounit;
1108         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1109                 rsize = clnt->msize - P9_IOHDRSZ;
1110
1111         if (count < rsize)
1112                 rsize = count;
1113
1114         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1115         if (IS_ERR(req)) {
1116                 err = PTR_ERR(req);
1117                 goto error;
1118         }
1119
1120         err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1121         if (err) {
1122                 p9pdu_dump(1, req->rc);
1123                 goto free_and_error;
1124         }
1125
1126         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1127
1128         if (data) {
1129                 memmove(data, dataptr, count);
1130                 data += count;
1131         }
1132
1133         if (udata) {
1134                 err = copy_to_user(udata, dataptr, count);
1135                 if (err) {
1136                         err = -EFAULT;
1137                         goto free_and_error;
1138                 }
1139         }
1140
1141         p9_free_req(clnt, req);
1142         return count;
1143
1144 free_and_error:
1145         p9_free_req(clnt, req);
1146 error:
1147         return err;
1148 }
1149 EXPORT_SYMBOL(p9_client_read);
1150
1151 int
1152 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1153                                                         u64 offset, u32 count)
1154 {
1155         int err, rsize, total;
1156         struct p9_client *clnt;
1157         struct p9_req_t *req;
1158
1159         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1160                                 fid->fid, (long long unsigned) offset, count);
1161         err = 0;
1162         clnt = fid->clnt;
1163         total = 0;
1164
1165         rsize = fid->iounit;
1166         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1167                 rsize = clnt->msize - P9_IOHDRSZ;
1168
1169         if (count < rsize)
1170                 rsize = count;
1171         if (data)
1172                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1173                                                                 rsize, data);
1174         else
1175                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1176                                                                 rsize, udata);
1177         if (IS_ERR(req)) {
1178                 err = PTR_ERR(req);
1179                 goto error;
1180         }
1181
1182         err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1183         if (err) {
1184                 p9pdu_dump(1, req->rc);
1185                 goto free_and_error;
1186         }
1187
1188         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1189
1190         p9_free_req(clnt, req);
1191         return count;
1192
1193 free_and_error:
1194         p9_free_req(clnt, req);
1195 error:
1196         return err;
1197 }
1198 EXPORT_SYMBOL(p9_client_write);
1199
1200 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1201 {
1202         int err;
1203         struct p9_client *clnt;
1204         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1205         struct p9_req_t *req;
1206         u16 ignored;
1207
1208         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1209
1210         if (!ret)
1211                 return ERR_PTR(-ENOMEM);
1212
1213         err = 0;
1214         clnt = fid->clnt;
1215
1216         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1217         if (IS_ERR(req)) {
1218                 err = PTR_ERR(req);
1219                 goto error;
1220         }
1221
1222         err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1223         if (err) {
1224                 ret = ERR_PTR(err);
1225                 p9pdu_dump(1, req->rc);
1226                 goto free_and_error;
1227         }
1228
1229         P9_DPRINTK(P9_DEBUG_9P,
1230                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1231                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1232                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1233                 "<<<    uid=%d gid=%d n_muid=%d\n",
1234                 ret->size, ret->type, ret->dev, ret->qid.type,
1235                 ret->qid.path, ret->qid.version, ret->mode,
1236                 ret->atime, ret->mtime, ret->length, ret->name,
1237                 ret->uid, ret->gid, ret->muid, ret->extension,
1238                 ret->n_uid, ret->n_gid, ret->n_muid);
1239
1240 free_and_error:
1241         p9_free_req(clnt, req);
1242 error:
1243         return ret;
1244 }
1245 EXPORT_SYMBOL(p9_client_stat);
1246
1247 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1248 {
1249         int err;
1250         struct p9_req_t *req;
1251         struct p9_client *clnt;
1252
1253         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1254         P9_DPRINTK(P9_DEBUG_9P,
1255                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1256                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1257                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1258                 "     uid=%d gid=%d n_muid=%d\n",
1259                 wst->size, wst->type, wst->dev, wst->qid.type,
1260                 wst->qid.path, wst->qid.version, wst->mode,
1261                 wst->atime, wst->mtime, wst->length, wst->name,
1262                 wst->uid, wst->gid, wst->muid, wst->extension,
1263                 wst->n_uid, wst->n_gid, wst->n_muid);
1264         err = 0;
1265         clnt = fid->clnt;
1266
1267         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, 0, wst);
1268         if (IS_ERR(req)) {
1269                 err = PTR_ERR(req);
1270                 goto error;
1271         }
1272
1273         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1274
1275         p9_free_req(clnt, req);
1276 error:
1277         return err;
1278 }
1279 EXPORT_SYMBOL(p9_client_wstat);