net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <[email protected]>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <[email protected]>
   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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/poll.h>
  32 #include <linux/idr.h>
  33 #include <linux/mutex.h>
  34 #include <linux/slab.h>
  35 #include <linux/sched.h>
  36 #include <linux/uaccess.h>
  37 #include <net/9p/9p.h>
  38 #include <linux/parser.h>
  39 #include <net/9p/client.h>
  40 #include <net/9p/transport.h>
  41 #include "protocol.h"
  42
  43 #define CREATE_TRACE_POINTS
  44 #include <trace/events/9p.h>
  45
  46 /*
  47   * Client Option Parsing (code inspired by NFS code)
  48   *  - a little lazy - parse all client options
  49   */
  50
  51 enum {
  52         Opt_msize,
  53         Opt_trans,
  54         Opt_legacy,
  55         Opt_version,
  56         Opt_err,
  57 };
  58
  59 static const match_table_t tokens = {
  60         {Opt_msize, "msize=%u"},
  61         {Opt_legacy, "noextend"},
  62         {Opt_trans, "trans=%s"},
  63         {Opt_version, "version=%s"},
  64         {Opt_err, NULL},
  65 };
  66
  67 inline int p9_is_proto_dotl(struct p9_client *clnt)
  68 {
  69         return clnt->proto_version == p9_proto_2000L;
  70 }
  71 EXPORT_SYMBOL(p9_is_proto_dotl);
  72
  73 inline int p9_is_proto_dotu(struct p9_client *clnt)
  74 {
  75         return clnt->proto_version == p9_proto_2000u;
  76 }
  77 EXPORT_SYMBOL(p9_is_proto_dotu);
  78
  79 /*
  80  * Some error codes are taken directly from the server replies,
  81  * make sure they are valid.
  82  */
  83 static int safe_errno(int err)
  84 {
  85         if ((err > 0) || (err < -MAX_ERRNO)) {
  86                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
  87                 return -EPROTO;
  88         }
  89         return err;
  90 }
  91
  92
  93 /* Interpret mount option for protocol version */
  94 static int get_protocol_version(char *s)
  95 {
  96         int version = -EINVAL;
  97
  98         if (!strcmp(s, "9p2000")) {
  99                 version = p9_proto_legacy;
 100                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
 101         } else if (!strcmp(s, "9p2000.u")) {
 102                 version = p9_proto_2000u;
 103                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
 104         } else if (!strcmp(s, "9p2000.L")) {
 105                 version = p9_proto_2000L;
 106                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
 107         } else
 108                 pr_info("Unknown protocol version %s\n", s);
 109
 110         return version;
 111 }
 112
 113 /**
 114  * parse_options - parse mount options into client structure
 115  * @opts: options string passed from mount
 116  * @clnt: existing v9fs client information
 117  *
 118  * Return 0 upon success, -ERRNO upon failure
 119  */
 120
 121 static int parse_opts(char *opts, struct p9_client *clnt)
 122 {
 123         char *options, *tmp_options;
 124         char *p;
 125         substring_t args[MAX_OPT_ARGS];
 126         int option;
 127         char *s;
 128         int ret = 0;
 129
 130         clnt->proto_version = p9_proto_2000L;
 131         clnt->msize = 8192;
 132
 133         if (!opts)
 134                 return 0;
 135
 136         tmp_options = kstrdup(opts, GFP_KERNEL);
 137         if (!tmp_options) {
 138                 p9_debug(P9_DEBUG_ERROR,
 139                          "failed to allocate copy of option string\n");
 140                 return -ENOMEM;
 141         }
 142         options = tmp_options;
 143
 144         while ((p = strsep(&options, ",")) != NULL) {
 145                 int token, r;
 146                 if (!*p)
 147                         continue;
 148                 token = match_token(p, tokens, args);
 149                 switch (token) {
 150                 case Opt_msize:
 151                         r = match_int(&args[0], &option);
 152                         if (r < 0) {
 153                                 p9_debug(P9_DEBUG_ERROR,
 154                                          "integer field, but no integer?\n");
 155                                 ret = r;
 156                                 continue;
 157                         }
 158                         clnt->msize = option;
 159                         break;
 160                 case Opt_trans:
 161                         s = match_strdup(&args[0]);
 162                         if (!s) {
 163                                 ret = -ENOMEM;
 164                                 p9_debug(P9_DEBUG_ERROR,
 165                                          "problem allocating copy of trans arg\n");
 166                                 goto free_and_return;
 167                          }
 168                         clnt->trans_mod = v9fs_get_trans_by_name(s);
 169                         if (clnt->trans_mod == NULL) {
 170                                 pr_info("Could not find request transport: %s\n",
 171                                         s);
 172                                 ret = -EINVAL;
 173                                 kfree(s);
 174                                 goto free_and_return;
 175                         }
 176                         kfree(s);
 177                         break;
 178                 case Opt_legacy:
 179                         clnt->proto_version = p9_proto_legacy;
 180                         break;
 181                 case Opt_version:
 182                         s = match_strdup(&args[0]);
 183                         if (!s) {
 184                                 ret = -ENOMEM;
 185                                 p9_debug(P9_DEBUG_ERROR,
 186                                          "problem allocating copy of version arg\n");
 187                                 goto free_and_return;
 188                         }
 189                         ret = get_protocol_version(s);
 190                         if (ret == -EINVAL) {
 191                                 kfree(s);
 192                                 goto free_and_return;
 193                         }
 194                         kfree(s);
 195                         clnt->proto_version = ret;
 196                         break;
 197                 default:
 198                         continue;
 199                 }
 200         }
 201
 202 free_and_return:
 203         kfree(tmp_options);
 204         return ret;
 205 }
 206
 207 static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
 208 {
 209         struct p9_fcall *fc;
 210         fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
 211         if (!fc)
 212                 return NULL;
 213         fc->capacity = alloc_msize;
 214         fc->sdata = (char *) fc + sizeof(struct p9_fcall);
 215         return fc;
 216 }
 217
 218 /**
 219  * p9_tag_alloc - lookup/allocate a request by tag
 220  * @c: client session to lookup tag within
 221  * @tag: numeric id for transaction
 222  *
 223  * this is a simple array lookup, but will grow the
 224  * request_slots as necessary to accommodate transaction
 225  * ids which did not previously have a slot.
 226  *
 227  * this code relies on the client spinlock to manage locks, its
 228  * possible we should switch to something else, but I'd rather
 229  * stick with something low-overhead for the common case.
 230  *
 231  */
 232
 233 static struct p9_req_t *
 234 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
 235 {
 236         unsigned long flags;
 237         int row, col;
 238         struct p9_req_t *req;
 239         int alloc_msize = min(c->msize, max_size);
 240
 241         /* This looks up the original request by tag so we know which
 242          * buffer to read the data into */
 243         tag++;
 244
 245         if (tag >= c->max_tag) {
 246                 spin_lock_irqsave(&c->lock, flags);
 247                 /* check again since original check was outside of lock */
 248                 while (tag >= c->max_tag) {
 249                         row = (tag / P9_ROW_MAXTAG);
 250                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 251                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 252
 253                         if (!c->reqs[row]) {
 254                                 pr_err("Couldn't grow tag array\n");
 255                                 spin_unlock_irqrestore(&c->lock, flags);
 256                                 return ERR_PTR(-ENOMEM);
 257                         }
 258                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 259                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 260                                 c->reqs[row][col].tc = NULL;
 261                         }
 262                         c->max_tag += P9_ROW_MAXTAG;
 263                 }
 264                 spin_unlock_irqrestore(&c->lock, flags);
 265         }
 266         row = tag / P9_ROW_MAXTAG;
 267         col = tag % P9_ROW_MAXTAG;
 268
 269         req = &c->reqs[row][col];
 270         if (!req->wq) {
 271                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
 272                 if (!req->wq)
 273                         goto grow_failed;
 274                 init_waitqueue_head(req->wq);
 275         }
 276
 277         if (!req->tc)
 278                 req->tc = p9_fcall_alloc(alloc_msize);
 279         if (!req->rc)
 280                 req->rc = p9_fcall_alloc(alloc_msize);
 281         if (!req->tc || !req->rc)
 282                 goto grow_failed;
 283
 284         p9pdu_reset(req->tc);
 285         p9pdu_reset(req->rc);
 286
 287         req->tc->tag = tag-1;
 288         req->status = REQ_STATUS_ALLOC;
 289
 290         return req;
 291
 292 grow_failed:
 293         pr_err("Couldn't grow tag array\n");
 294         kfree(req->tc);
 295         kfree(req->rc);
 296         kfree(req->wq);
 297         req->tc = req->rc = NULL;
 298         req->wq = NULL;
 299         return ERR_PTR(-ENOMEM);
 300 }
 301
 302 /**
 303  * p9_tag_lookup - lookup a request by tag
 304  * @c: client session to lookup tag within
 305  * @tag: numeric id for transaction
 306  *
 307  */
 308
 309 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 310 {
 311         int row, col;
 312
 313         /* This looks up the original request by tag so we know which
 314          * buffer to read the data into */
 315         tag++;
 316
 317         if(tag >= c->max_tag)
 318                 return NULL;
 319
 320         row = tag / P9_ROW_MAXTAG;
 321         col = tag % P9_ROW_MAXTAG;
 322
 323         return &c->reqs[row][col];
 324 }
 325 EXPORT_SYMBOL(p9_tag_lookup);
 326
 327 /**
 328  * p9_tag_init - setup tags structure and contents
 329  * @c:  v9fs client struct
 330  *
 331  * This initializes the tags structure for each client instance.
 332  *
 333  */
 334
 335 static int p9_tag_init(struct p9_client *c)
 336 {
 337         int err = 0;
 338
 339         c->tagpool = p9_idpool_create();
 340         if (IS_ERR(c->tagpool)) {
 341                 err = PTR_ERR(c->tagpool);
 342                 goto error;
 343         }
 344         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
 345         if (err < 0) {
 346                 p9_idpool_destroy(c->tagpool);
 347                 goto error;
 348         }
 349         c->max_tag = 0;
 350 error:
 351         return err;
 352 }
 353
 354 /**
 355  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 356  * @c:  v9fs client struct
 357  *
 358  * This frees resources associated with the tags structure
 359  *
 360  */
 361 static void p9_tag_cleanup(struct p9_client *c)
 362 {
 363         int row, col;
 364
 365         /* check to insure all requests are idle */
 366         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 367                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 368                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 369                                 p9_debug(P9_DEBUG_MUX,
 370                                          "Attempting to cleanup non-free tag %d,%d\n",
 371                                          row, col);
 372                                 /* TODO: delay execution of cleanup */
 373                                 return;
 374                         }
 375                 }
 376         }
 377
 378         if (c->tagpool) {
 379                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
 380                 p9_idpool_destroy(c->tagpool);
 381         }
 382
 383         /* free requests associated with tags */
 384         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 385                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 386                         kfree(c->reqs[row][col].wq);
 387                         kfree(c->reqs[row][col].tc);
 388                         kfree(c->reqs[row][col].rc);
 389                 }
 390                 kfree(c->reqs[row]);
 391         }
 392         c->max_tag = 0;
 393 }
 394
 395 /**
 396  * p9_free_req - free a request and clean-up as necessary
 397  * c: client state
 398  * r: request to release
 399  *
 400  */
 401
 402 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 403 {
 404         int tag = r->tc->tag;
 405         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 406
 407         r->status = REQ_STATUS_IDLE;
 408         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 409                 p9_idpool_put(tag, c->tagpool);
 410 }
 411
 412 /**
 413  * p9_client_cb - call back from transport to client
 414  * c: client state
 415  * req: request received
 416  *
 417  */
 418 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 419 {
 420         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 421
 422         /*
 423          * This barrier is needed to make sure any change made to req before
 424          * the other thread wakes up will indeed be seen by the waiting side.
 425          */
 426         smp_wmb();
 427         req->status = status;
 428
 429         wake_up(req->wq);
 430         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 431 }
 432 EXPORT_SYMBOL(p9_client_cb);
 433
 434 /**
 435  * p9_parse_header - parse header arguments out of a packet
 436  * @pdu: packet to parse
 437  * @size: size of packet
 438  * @type: type of request
 439  * @tag: tag of packet
 440  * @rewind: set if we need to rewind offset afterwards
 441  */
 442
 443 int
 444 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 445                                                                 int rewind)
 446 {
 447         int8_t r_type;
 448         int16_t r_tag;
 449         int32_t r_size;
 450         int offset = pdu->offset;
 451         int err;
 452
 453         pdu->offset = 0;
 454         if (pdu->size == 0)
 455                 pdu->size = 7;
 456
 457         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 458         if (err)
 459                 goto rewind_and_exit;
 460
 461         pdu->size = r_size;
 462         pdu->id = r_type;
 463         pdu->tag = r_tag;
 464
 465         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 466                  pdu->size, pdu->id, pdu->tag);
 467
 468         if (type)
 469                 *type = r_type;
 470         if (tag)
 471                 *tag = r_tag;
 472         if (size)
 473                 *size = r_size;
 474
 475
 476 rewind_and_exit:
 477         if (rewind)
 478                 pdu->offset = offset;
 479         return err;
 480 }
 481 EXPORT_SYMBOL(p9_parse_header);
 482
 483 /**
 484  * p9_check_errors - check 9p packet for error return and process it
 485  * @c: current client instance
 486  * @req: request to parse and check for error conditions
 487  *
 488  * returns error code if one is discovered, otherwise returns 0
 489  *
 490  * this will have to be more complicated if we have multiple
 491  * error packet types
 492  */
 493
 494 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 495 {
 496         int8_t type;
 497         int err;
 498         int ecode;
 499
 500         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 501         /*
 502          * dump the response from server
 503          * This should be after check errors which poplulate pdu_fcall.
 504          */
 505         trace_9p_protocol_dump(c, req->rc);
 506         if (err) {
 507                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 508                 return err;
 509         }
 510         if (type != P9_RERROR && type != P9_RLERROR)
 511                 return 0;
 512
 513         if (!p9_is_proto_dotl(c)) {
 514                 char *ename;
 515                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 516                                   &ename, &ecode);
 517                 if (err)
 518                         goto out_err;
 519
 520                 if (p9_is_proto_dotu(c))
 521                         err = -ecode;
 522
 523                 if (!err || !IS_ERR_VALUE(err)) {
 524                         err = p9_errstr2errno(ename, strlen(ename));
 525
 526                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 527                                  -ecode, ename);
 528                 }
 529                 kfree(ename);
 530         } else {
 531                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 532                 err = -ecode;
 533
 534                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 535         }
 536
 537         return err;
 538
 539 out_err:
 540         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 541
 542         return err;
 543 }
 544
 545 /**
 546  * p9_check_zc_errors - check 9p packet for error return and process it
 547  * @c: current client instance
 548  * @req: request to parse and check for error conditions
 549  * @in_hdrlen: Size of response protocol buffer.
 550  *
 551  * returns error code if one is discovered, otherwise returns 0
 552  *
 553  * this will have to be more complicated if we have multiple
 554  * error packet types
 555  */
 556
 557 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 558                               char *uidata, int in_hdrlen, int kern_buf)
 559 {
 560         int err;
 561         int ecode;
 562         int8_t type;
 563         char *ename = NULL;
 564
 565         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 566         /*
 567          * dump the response from server
 568          * This should be after parse_header which poplulate pdu_fcall.
 569          */
 570         trace_9p_protocol_dump(c, req->rc);
 571         if (err) {
 572                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 573                 return err;
 574         }
 575
 576         if (type != P9_RERROR && type != P9_RLERROR)
 577                 return 0;
 578
 579         if (!p9_is_proto_dotl(c)) {
 580                 /* Error is reported in string format */
 581                 int len;
 582                 /* 7 = header size for RERROR; */
 583                 int inline_len = in_hdrlen - 7;
 584
 585                 len =  req->rc->size - req->rc->offset;
 586                 if (len > (P9_ZC_HDR_SZ - 7)) {
 587                         err = -EFAULT;
 588                         goto out_err;
 589                 }
 590
 591                 ename = &req->rc->sdata[req->rc->offset];
 592                 if (len > inline_len) {
 593                         /* We have error in external buffer */
 594                         if (kern_buf) {
 595                                 memcpy(ename + inline_len, uidata,
 596                                        len - inline_len);
 597                         } else {
 598                                 err = copy_from_user(ename + inline_len,
 599                                                      uidata, len - inline_len);
 600                                 if (err) {
 601                                         err = -EFAULT;
 602                                         goto out_err;
 603                                 }
 604                         }
 605                 }
 606                 ename = NULL;
 607                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 608                                   &ename, &ecode);
 609                 if (err)
 610                         goto out_err;
 611
 612                 if (p9_is_proto_dotu(c))
 613                         err = -ecode;
 614
 615                 if (!err || !IS_ERR_VALUE(err)) {
 616                         err = p9_errstr2errno(ename, strlen(ename));
 617
 618                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 619                                  -ecode, ename);
 620                 }
 621                 kfree(ename);
 622         } else {
 623                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 624                 err = -ecode;
 625
 626                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 627         }
 628         return err;
 629
 630 out_err:
 631         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 632         return err;
 633 }
 634
 635 static struct p9_req_t *
 636 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 637
 638 /**
 639  * p9_client_flush - flush (cancel) a request
 640  * @c: client state
 641  * @oldreq: request to cancel
 642  *
 643  * This sents a flush for a particular request and links
 644  * the flush request to the original request.  The current
 645  * code only supports a single flush request although the protocol
 646  * allows for multiple flush requests to be sent for a single request.
 647  *
 648  */
 649
 650 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 651 {
 652         struct p9_req_t *req;
 653         int16_t oldtag;
 654         int err;
 655
 656         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 657         if (err)
 658                 return err;
 659
 660         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 661
 662         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 663         if (IS_ERR(req))
 664                 return PTR_ERR(req);
 665
 666         /*
 667          * if we haven't received a response for oldreq,
 668          * remove it from the list
 669          */
 670         if (oldreq->status == REQ_STATUS_SENT)
 671                 if (c->trans_mod->cancelled)
 672                         c->trans_mod->cancelled(c, oldreq);
 673
 674         p9_free_req(c, req);
 675         return 0;
 676 }
 677
 678 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 679                                               int8_t type, int req_size,
 680                                               const char *fmt, va_list ap)
 681 {
 682         int tag, err;
 683         struct p9_req_t *req;
 684
 685         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 686
 687         /* we allow for any status other than disconnected */
 688         if (c->status == Disconnected)
 689                 return ERR_PTR(-EIO);
 690
 691         /* if status is begin_disconnected we allow only clunk request */
 692         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 693                 return ERR_PTR(-EIO);
 694
 695         tag = P9_NOTAG;
 696         if (type != P9_TVERSION) {
 697                 tag = p9_idpool_get(c->tagpool);
 698                 if (tag < 0)
 699                         return ERR_PTR(-ENOMEM);
 700         }
 701
 702         req = p9_tag_alloc(c, tag, req_size);
 703         if (IS_ERR(req))
 704                 return req;
 705
 706         /* marshall the data */
 707         p9pdu_prepare(req->tc, tag, type);
 708         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 709         if (err)
 710                 goto reterr;
 711         p9pdu_finalize(c, req->tc);
 712         trace_9p_client_req(c, type, tag);
 713         return req;
 714 reterr:
 715         p9_free_req(c, req);
 716         return ERR_PTR(err);
 717 }
 718
 719 /**
 720  * p9_client_rpc - issue a request and wait for a response
 721  * @c: client session
 722  * @type: type of request
 723  * @fmt: protocol format string (see protocol.c)
 724  *
 725  * Returns request structure (which client must free using p9_free_req)
 726  */
 727
 728 static struct p9_req_t *
 729 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 730 {
 731         va_list ap;
 732         int sigpending, err;
 733         unsigned long flags;
 734         struct p9_req_t *req;
 735
 736         va_start(ap, fmt);
 737         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 738         va_end(ap);
 739         if (IS_ERR(req))
 740                 return req;
 741
 742         if (signal_pending(current)) {
 743                 sigpending = 1;
 744                 clear_thread_flag(TIF_SIGPENDING);
 745         } else
 746                 sigpending = 0;
 747
 748         err = c->trans_mod->request(c, req);
 749         if (err < 0) {
 750                 if (err != -ERESTARTSYS && err != -EFAULT)
 751                         c->status = Disconnected;
 752                 goto reterr;
 753         }
 754 again:
 755         /* Wait for the response */
 756         err = wait_event_interruptible(*req->wq,
 757                                        req->status >= REQ_STATUS_RCVD);
 758
 759         /*
 760          * Make sure our req is coherent with regard to updates in other
 761          * threads - echoes to wmb() in the callback
 762          */
 763         smp_rmb();
 764
 765         if ((err == -ERESTARTSYS) && (c->status == Connected)
 766                                   && (type == P9_TFLUSH)) {
 767                 sigpending = 1;
 768                 clear_thread_flag(TIF_SIGPENDING);
 769                 goto again;
 770         }
 771
 772         if (req->status == REQ_STATUS_ERROR) {
 773                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 774                 err = req->t_err;
 775         }
 776         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 777                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 778                 sigpending = 1;
 779                 clear_thread_flag(TIF_SIGPENDING);
 780
 781                 if (c->trans_mod->cancel(c, req))
 782                         p9_client_flush(c, req);
 783
 784                 /* if we received the response anyway, don't signal error */
 785                 if (req->status == REQ_STATUS_RCVD)
 786                         err = 0;
 787         }
 788         if (sigpending) {
 789                 spin_lock_irqsave(&current->sighand->siglock, flags);
 790                 recalc_sigpending();
 791                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 792         }
 793         if (err < 0)
 794                 goto reterr;
 795
 796         err = p9_check_errors(c, req);
 797         trace_9p_client_res(c, type, req->rc->tag, err);
 798         if (!err)
 799                 return req;
 800 reterr:
 801         p9_free_req(c, req);
 802         return ERR_PTR(safe_errno(err));
 803 }
 804
 805 /**
 806  * p9_client_zc_rpc - issue a request and wait for a response
 807  * @c: client session
 808  * @type: type of request
 809  * @uidata: user bffer that should be ued for zero copy read
 810  * @uodata: user buffer that shoud be user for zero copy write
 811  * @inlen: read buffer size
 812  * @olen: write buffer size
 813  * @hdrlen: reader header size, This is the size of response protocol data
 814  * @fmt: protocol format string (see protocol.c)
 815  *
 816  * Returns request structure (which client must free using p9_free_req)
 817  */
 818 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 819                                          char *uidata, char *uodata,
 820                                          int inlen, int olen, int in_hdrlen,
 821                                          int kern_buf, const char *fmt, ...)
 822 {
 823         va_list ap;
 824         int sigpending, err;
 825         unsigned long flags;
 826         struct p9_req_t *req;
 827
 828         va_start(ap, fmt);
 829         /*
 830          * We allocate a inline protocol data of only 4k bytes.
 831          * The actual content is passed in zero-copy fashion.
 832          */
 833         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 834         va_end(ap);
 835         if (IS_ERR(req))
 836                 return req;
 837
 838         if (signal_pending(current)) {
 839                 sigpending = 1;
 840                 clear_thread_flag(TIF_SIGPENDING);
 841         } else
 842                 sigpending = 0;
 843
 844         /* If we are called with KERNEL_DS force kern_buf */
 845         if (segment_eq(get_fs(), KERNEL_DS))
 846                 kern_buf = 1;
 847
 848         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 849                                        inlen, olen, in_hdrlen, kern_buf);
 850         if (err < 0) {
 851                 if (err == -EIO)
 852                         c->status = Disconnected;
 853                 goto reterr;
 854         }
 855         if (req->status == REQ_STATUS_ERROR) {
 856                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 857                 err = req->t_err;
 858         }
 859         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 860                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 861                 sigpending = 1;
 862                 clear_thread_flag(TIF_SIGPENDING);
 863
 864                 if (c->trans_mod->cancel(c, req))
 865                         p9_client_flush(c, req);
 866
 867                 /* if we received the response anyway, don't signal error */
 868                 if (req->status == REQ_STATUS_RCVD)
 869                         err = 0;
 870         }
 871         if (sigpending) {
 872                 spin_lock_irqsave(&current->sighand->siglock, flags);
 873                 recalc_sigpending();
 874                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 875         }
 876         if (err < 0)
 877                 goto reterr;
 878
 879         err = p9_check_zc_errors(c, req, uidata, in_hdrlen, kern_buf);
 880         trace_9p_client_res(c, type, req->rc->tag, err);
 881         if (!err)
 882                 return req;
 883 reterr:
 884         p9_free_req(c, req);
 885         return ERR_PTR(safe_errno(err));
 886 }
 887
 888 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 889 {
 890         int ret;
 891         struct p9_fid *fid;
 892         unsigned long flags;
 893
 894         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 895         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 896         if (!fid)
 897                 return ERR_PTR(-ENOMEM);
 898
 899         ret = p9_idpool_get(clnt->fidpool);
 900         if (ret < 0) {
 901                 ret = -ENOSPC;
 902                 goto error;
 903         }
 904         fid->fid = ret;
 905
 906         memset(&fid->qid, 0, sizeof(struct p9_qid));
 907         fid->mode = -1;
 908         fid->uid = current_fsuid();
 909         fid->clnt = clnt;
 910         fid->rdir = NULL;
 911         spin_lock_irqsave(&clnt->lock, flags);
 912         list_add(&fid->flist, &clnt->fidlist);
 913         spin_unlock_irqrestore(&clnt->lock, flags);
 914
 915         return fid;
 916
 917 error:
 918         kfree(fid);
 919         return ERR_PTR(ret);
 920 }
 921
 922 static void p9_fid_destroy(struct p9_fid *fid)
 923 {
 924         struct p9_client *clnt;
 925         unsigned long flags;
 926
 927         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 928         clnt = fid->clnt;
 929         p9_idpool_put(fid->fid, clnt->fidpool);
 930         spin_lock_irqsave(&clnt->lock, flags);
 931         list_del(&fid->flist);
 932         spin_unlock_irqrestore(&clnt->lock, flags);
 933         kfree(fid->rdir);
 934         kfree(fid);
 935 }
 936
 937 static int p9_client_version(struct p9_client *c)
 938 {
 939         int err = 0;
 940         struct p9_req_t *req;
 941         char *version;
 942         int msize;
 943
 944         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 945                  c->msize, c->proto_version);
 946
 947         switch (c->proto_version) {
 948         case p9_proto_2000L:
 949                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 950                                         c->msize, "9P2000.L");
 951                 break;
 952         case p9_proto_2000u:
 953                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 954                                         c->msize, "9P2000.u");
 955                 break;
 956         case p9_proto_legacy:
 957                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 958                                         c->msize, "9P2000");
 959                 break;
 960         default:
 961                 return -EINVAL;
 962         }
 963
 964         if (IS_ERR(req))
 965                 return PTR_ERR(req);
 966
 967         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 968         if (err) {
 969                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 970                 trace_9p_protocol_dump(c, req->rc);
 971                 goto error;
 972         }
 973
 974         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 975         if (!strncmp(version, "9P2000.L", 8))
 976                 c->proto_version = p9_proto_2000L;
 977         else if (!strncmp(version, "9P2000.u", 8))
 978                 c->proto_version = p9_proto_2000u;
 979         else if (!strncmp(version, "9P2000", 6))
 980                 c->proto_version = p9_proto_legacy;
 981         else {
 982                 err = -EREMOTEIO;
 983                 goto error;
 984         }
 985
 986         if (msize < c->msize)
 987                 c->msize = msize;
 988
 989 error:
 990         kfree(version);
 991         p9_free_req(c, req);
 992
 993         return err;
 994 }
 995
 996 struct p9_client *p9_client_create(const char *dev_name, char *options)
 997 {
 998         int err;
 999         struct p9_client *clnt;
1000         char *client_id;
1001
1002         err = 0;
1003         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1004         if (!clnt)
1005                 return ERR_PTR(-ENOMEM);
1006
1007         clnt->trans_mod = NULL;
1008         clnt->trans = NULL;
1009
1010         client_id = utsname()->nodename;
1011         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1012
1013         spin_lock_init(&clnt->lock);
1014         INIT_LIST_HEAD(&clnt->fidlist);
1015
1016         err = p9_tag_init(clnt);
1017         if (err < 0)
1018                 goto free_client;
1019
1020         err = parse_opts(options, clnt);
1021         if (err < 0)
1022                 goto destroy_tagpool;
1023
1024         if (!clnt->trans_mod)
1025                 clnt->trans_mod = v9fs_get_default_trans();
1026
1027         if (clnt->trans_mod == NULL) {
1028                 err = -EPROTONOSUPPORT;
1029                 p9_debug(P9_DEBUG_ERROR,
1030                          "No transport defined or default transport\n");
1031                 goto destroy_tagpool;
1032         }
1033
1034         clnt->fidpool = p9_idpool_create();
1035         if (IS_ERR(clnt->fidpool)) {
1036                 err = PTR_ERR(clnt->fidpool);
1037                 goto put_trans;
1038         }
1039
1040         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1041                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1042
1043         err = clnt->trans_mod->create(clnt, dev_name, options);
1044         if (err)
1045                 goto destroy_fidpool;
1046
1047         if (clnt->msize > clnt->trans_mod->maxsize)
1048                 clnt->msize = clnt->trans_mod->maxsize;
1049
1050         err = p9_client_version(clnt);
1051         if (err)
1052                 goto close_trans;
1053
1054         return clnt;
1055
1056 close_trans:
1057         clnt->trans_mod->close(clnt);
1058 destroy_fidpool:
1059         p9_idpool_destroy(clnt->fidpool);
1060 put_trans:
1061         v9fs_put_trans(clnt->trans_mod);
1062 destroy_tagpool:
1063         p9_idpool_destroy(clnt->tagpool);
1064 free_client:
1065         kfree(clnt);
1066         return ERR_PTR(err);
1067 }
1068 EXPORT_SYMBOL(p9_client_create);
1069
1070 void p9_client_destroy(struct p9_client *clnt)
1071 {
1072         struct p9_fid *fid, *fidptr;
1073
1074         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1075
1076         if (clnt->trans_mod)
1077                 clnt->trans_mod->close(clnt);
1078
1079         v9fs_put_trans(clnt->trans_mod);
1080
1081         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1082                 pr_info("Found fid %d not clunked\n", fid->fid);
1083                 p9_fid_destroy(fid);
1084         }
1085
1086         if (clnt->fidpool)
1087                 p9_idpool_destroy(clnt->fidpool);
1088
1089         p9_tag_cleanup(clnt);
1090
1091         kfree(clnt);
1092 }
1093 EXPORT_SYMBOL(p9_client_destroy);
1094
1095 void p9_client_disconnect(struct p9_client *clnt)
1096 {
1097         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1098         clnt->status = Disconnected;
1099 }
1100 EXPORT_SYMBOL(p9_client_disconnect);
1101
1102 void p9_client_begin_disconnect(struct p9_client *clnt)
1103 {
1104         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1105         clnt->status = BeginDisconnect;
1106 }
1107 EXPORT_SYMBOL(p9_client_begin_disconnect);
1108
1109 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1110         char *uname, kuid_t n_uname, char *aname)
1111 {
1112         int err = 0;
1113         struct p9_req_t *req;
1114         struct p9_fid *fid;
1115         struct p9_qid qid;
1116
1117
1118         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1119                  afid ? afid->fid : -1, uname, aname);
1120         fid = p9_fid_create(clnt);
1121         if (IS_ERR(fid)) {
1122                 err = PTR_ERR(fid);
1123                 fid = NULL;
1124                 goto error;
1125         }
1126
1127         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1128                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1129         if (IS_ERR(req)) {
1130                 err = PTR_ERR(req);
1131                 goto error;
1132         }
1133
1134         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1135         if (err) {
1136                 trace_9p_protocol_dump(clnt, req->rc);
1137                 p9_free_req(clnt, req);
1138                 goto error;
1139         }
1140
1141         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1142                  qid.type, (unsigned long long)qid.path, qid.version);
1143
1144         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1145
1146         p9_free_req(clnt, req);
1147         return fid;
1148
1149 error:
1150         if (fid)
1151                 p9_fid_destroy(fid);
1152         return ERR_PTR(err);
1153 }
1154 EXPORT_SYMBOL(p9_client_attach);
1155
1156 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1157                 char **wnames, int clone)
1158 {
1159         int err;
1160         struct p9_client *clnt;
1161         struct p9_fid *fid;
1162         struct p9_qid *wqids;
1163         struct p9_req_t *req;
1164         uint16_t nwqids, count;
1165
1166         err = 0;
1167         wqids = NULL;
1168         clnt = oldfid->clnt;
1169         if (clone) {
1170                 fid = p9_fid_create(clnt);
1171                 if (IS_ERR(fid)) {
1172                         err = PTR_ERR(fid);
1173                         fid = NULL;
1174                         goto error;
1175                 }
1176
1177                 fid->uid = oldfid->uid;
1178         } else
1179                 fid = oldfid;
1180
1181
1182         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1183                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1184
1185         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1186                                                                 nwname, wnames);
1187         if (IS_ERR(req)) {
1188                 err = PTR_ERR(req);
1189                 goto error;
1190         }
1191
1192         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1193         if (err) {
1194                 trace_9p_protocol_dump(clnt, req->rc);
1195                 p9_free_req(clnt, req);
1196                 goto clunk_fid;
1197         }
1198         p9_free_req(clnt, req);
1199
1200         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1201
1202         if (nwqids != nwname) {
1203                 err = -ENOENT;
1204                 goto clunk_fid;
1205         }
1206
1207         for (count = 0; count < nwqids; count++)
1208                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1209                         count, wqids[count].type,
1210                         (unsigned long long)wqids[count].path,
1211                         wqids[count].version);
1212
1213         if (nwname)
1214                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1215         else
1216                 fid->qid = oldfid->qid;
1217
1218         kfree(wqids);
1219         return fid;
1220
1221 clunk_fid:
1222         kfree(wqids);
1223         p9_client_clunk(fid);
1224         fid = NULL;
1225
1226 error:
1227         if (fid && (fid != oldfid))
1228                 p9_fid_destroy(fid);
1229
1230         return ERR_PTR(err);
1231 }
1232 EXPORT_SYMBOL(p9_client_walk);
1233
1234 int p9_client_open(struct p9_fid *fid, int mode)
1235 {
1236         int err;
1237         struct p9_client *clnt;
1238         struct p9_req_t *req;
1239         struct p9_qid qid;
1240         int iounit;
1241
1242         clnt = fid->clnt;
1243         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1244                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1245         err = 0;
1246
1247         if (fid->mode != -1)
1248                 return -EINVAL;
1249
1250         if (p9_is_proto_dotl(clnt))
1251                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1252         else
1253                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1254         if (IS_ERR(req)) {
1255                 err = PTR_ERR(req);
1256                 goto error;
1257         }
1258
1259         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1260         if (err) {
1261                 trace_9p_protocol_dump(clnt, req->rc);
1262                 goto free_and_error;
1263         }
1264
1265         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1266                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1267                 (unsigned long long)qid.path, qid.version, iounit);
1268
1269         fid->mode = mode;
1270         fid->iounit = iounit;
1271
1272 free_and_error:
1273         p9_free_req(clnt, req);
1274 error:
1275         return err;
1276 }
1277 EXPORT_SYMBOL(p9_client_open);
1278
1279 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1280                 kgid_t gid, struct p9_qid *qid)
1281 {
1282         int err = 0;
1283         struct p9_client *clnt;
1284         struct p9_req_t *req;
1285         int iounit;
1286
1287         p9_debug(P9_DEBUG_9P,
1288                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1289                         ofid->fid, name, flags, mode,
1290                         from_kgid(&init_user_ns, gid));
1291         clnt = ofid->clnt;
1292
1293         if (ofid->mode != -1)
1294                 return -EINVAL;
1295
1296         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1297                         mode, gid);
1298         if (IS_ERR(req)) {
1299                 err = PTR_ERR(req);
1300                 goto error;
1301         }
1302
1303         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1304         if (err) {
1305                 trace_9p_protocol_dump(clnt, req->rc);
1306                 goto free_and_error;
1307         }
1308
1309         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1310                         qid->type,
1311                         (unsigned long long)qid->path,
1312                         qid->version, iounit);
1313
1314         ofid->mode = mode;
1315         ofid->iounit = iounit;
1316
1317 free_and_error:
1318         p9_free_req(clnt, req);
1319 error:
1320         return err;
1321 }
1322 EXPORT_SYMBOL(p9_client_create_dotl);
1323
1324 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1325                      char *extension)
1326 {
1327         int err;
1328         struct p9_client *clnt;
1329         struct p9_req_t *req;
1330         struct p9_qid qid;
1331         int iounit;
1332
1333         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1334                                                 fid->fid, name, perm, mode);
1335         err = 0;
1336         clnt = fid->clnt;
1337
1338         if (fid->mode != -1)
1339                 return -EINVAL;
1340
1341         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1342                                 mode, extension);
1343         if (IS_ERR(req)) {
1344                 err = PTR_ERR(req);
1345                 goto error;
1346         }
1347
1348         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1349         if (err) {
1350                 trace_9p_protocol_dump(clnt, req->rc);
1351                 goto free_and_error;
1352         }
1353
1354         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1355                                 qid.type,
1356                                 (unsigned long long)qid.path,
1357                                 qid.version, iounit);
1358
1359         fid->mode = mode;
1360         fid->iounit = iounit;
1361
1362 free_and_error:
1363         p9_free_req(clnt, req);
1364 error:
1365         return err;
1366 }
1367 EXPORT_SYMBOL(p9_client_fcreate);
1368
1369 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
1370                 struct p9_qid *qid)
1371 {
1372         int err = 0;
1373         struct p9_client *clnt;
1374         struct p9_req_t *req;
1375
1376         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1377                         dfid->fid, name, symtgt);
1378         clnt = dfid->clnt;
1379
1380         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1381                         gid);
1382         if (IS_ERR(req)) {
1383                 err = PTR_ERR(req);
1384                 goto error;
1385         }
1386
1387         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1388         if (err) {
1389                 trace_9p_protocol_dump(clnt, req->rc);
1390                 goto free_and_error;
1391         }
1392
1393         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1394                         qid->type, (unsigned long long)qid->path, qid->version);
1395
1396 free_and_error:
1397         p9_free_req(clnt, req);
1398 error:
1399         return err;
1400 }
1401 EXPORT_SYMBOL(p9_client_symlink);
1402
1403 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1404 {
1405         struct p9_client *clnt;
1406         struct p9_req_t *req;
1407
1408         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1409                         dfid->fid, oldfid->fid, newname);
1410         clnt = dfid->clnt;
1411         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1412                         newname);
1413         if (IS_ERR(req))
1414                 return PTR_ERR(req);
1415
1416         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1417         p9_free_req(clnt, req);
1418         return 0;
1419 }
1420 EXPORT_SYMBOL(p9_client_link);
1421
1422 int p9_client_fsync(struct p9_fid *fid, int datasync)
1423 {
1424         int err;
1425         struct p9_client *clnt;
1426         struct p9_req_t *req;
1427
1428         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1429                         fid->fid, datasync);
1430         err = 0;
1431         clnt = fid->clnt;
1432
1433         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1434         if (IS_ERR(req)) {
1435                 err = PTR_ERR(req);
1436                 goto error;
1437         }
1438
1439         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1440
1441         p9_free_req(clnt, req);
1442
1443 error:
1444         return err;
1445 }
1446 EXPORT_SYMBOL(p9_client_fsync);
1447
1448 int p9_client_clunk(struct p9_fid *fid)
1449 {
1450         int err;
1451         struct p9_client *clnt;
1452         struct p9_req_t *req;
1453         int retries = 0;
1454
1455         if (!fid) {
1456                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1457                         __func__, task_pid_nr(current));
1458                 dump_stack();
1459                 return 0;
1460         }
1461
1462 again:
1463         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1464                                                                 retries);
1465         err = 0;
1466         clnt = fid->clnt;
1467
1468         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1469         if (IS_ERR(req)) {
1470                 err = PTR_ERR(req);
1471                 goto error;
1472         }
1473
1474         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1475
1476         p9_free_req(clnt, req);
1477 error:
1478         /*
1479          * Fid is not valid even after a failed clunk
1480          * If interrupted, retry once then give up and
1481          * leak fid until umount.
1482          */
1483         if (err == -ERESTARTSYS) {
1484                 if (retries++ == 0)
1485                         goto again;
1486         } else
1487                 p9_fid_destroy(fid);
1488         return err;
1489 }
1490 EXPORT_SYMBOL(p9_client_clunk);
1491
1492 int p9_client_remove(struct p9_fid *fid)
1493 {
1494         int err;
1495         struct p9_client *clnt;
1496         struct p9_req_t *req;
1497
1498         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1499         err = 0;
1500         clnt = fid->clnt;
1501
1502         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1503         if (IS_ERR(req)) {
1504                 err = PTR_ERR(req);
1505                 goto error;
1506         }
1507
1508         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1509
1510         p9_free_req(clnt, req);
1511 error:
1512         if (err == -ERESTARTSYS)
1513                 p9_client_clunk(fid);
1514         else
1515                 p9_fid_destroy(fid);
1516         return err;
1517 }
1518 EXPORT_SYMBOL(p9_client_remove);
1519
1520 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1521 {
1522         int err = 0;
1523         struct p9_req_t *req;
1524         struct p9_client *clnt;
1525
1526         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1527                    dfid->fid, name, flags);
1528
1529         clnt = dfid->clnt;
1530         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1531         if (IS_ERR(req)) {
1532                 err = PTR_ERR(req);
1533                 goto error;
1534         }
1535         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1536
1537         p9_free_req(clnt, req);
1538 error:
1539         return err;
1540 }
1541 EXPORT_SYMBOL(p9_client_unlinkat);
1542
1543 int
1544 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1545                                                                 u32 count)
1546 {
1547         char *dataptr;
1548         int kernel_buf = 0;
1549         struct p9_req_t *req;
1550         struct p9_client *clnt;
1551         int err, rsize, non_zc = 0;
1552
1553
1554         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1555                    fid->fid, (unsigned long long) offset, count);
1556         err = 0;
1557         clnt = fid->clnt;
1558
1559         rsize = fid->iounit;
1560         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1561                 rsize = clnt->msize - P9_IOHDRSZ;
1562
1563         if (count < rsize)
1564                 rsize = count;
1565
1566         /* Don't bother zerocopy for small IO (< 1024) */
1567         if (clnt->trans_mod->zc_request && rsize > 1024) {
1568                 char *indata;
1569                 if (data) {
1570                         kernel_buf = 1;
1571                         indata = data;
1572                 } else
1573                         indata = (__force char *)udata;
1574                 /*
1575                  * response header len is 11
1576                  * PDU Header(7) + IO Size (4)
1577                  */
1578                 req = p9_client_zc_rpc(clnt, P9_TREAD, indata, NULL, rsize, 0,
1579                                        11, kernel_buf, "dqd", fid->fid,
1580                                        offset, rsize);
1581         } else {
1582                 non_zc = 1;
1583                 req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1584                                     rsize);
1585         }
1586         if (IS_ERR(req)) {
1587                 err = PTR_ERR(req);
1588                 goto error;
1589         }
1590
1591         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1592         if (err) {
1593                 trace_9p_protocol_dump(clnt, req->rc);
1594                 goto free_and_error;
1595         }
1596
1597         p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1598
1599         if (non_zc) {
1600                 if (data) {
1601                         memmove(data, dataptr, count);
1602                 } else {
1603                         err = copy_to_user(udata, dataptr, count);
1604                         if (err) {
1605                                 err = -EFAULT;
1606                                 goto free_and_error;
1607                         }
1608                 }
1609         }
1610         p9_free_req(clnt, req);
1611         return count;
1612
1613 free_and_error:
1614         p9_free_req(clnt, req);
1615 error:
1616         return err;
1617 }
1618 EXPORT_SYMBOL(p9_client_read);
1619
1620 int
1621 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1622                                                         u64 offset, u32 count)
1623 {
1624         int err, rsize;
1625         int kernel_buf = 0;
1626         struct p9_client *clnt;
1627         struct p9_req_t *req;
1628
1629         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1630                                 fid->fid, (unsigned long long) offset, count);
1631         err = 0;
1632         clnt = fid->clnt;
1633
1634         rsize = fid->iounit;
1635         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1636                 rsize = clnt->msize - P9_IOHDRSZ;
1637
1638         if (count < rsize)
1639                 rsize = count;
1640
1641         /* Don't bother zerocopy for small IO (< 1024) */
1642         if (clnt->trans_mod->zc_request && rsize > 1024) {
1643                 char *odata;
1644                 if (data) {
1645                         kernel_buf = 1;
1646                         odata = data;
1647                 } else
1648                         odata = (char *)udata;
1649                 req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, odata, 0, rsize,
1650                                        P9_ZC_HDR_SZ, kernel_buf, "dqd",
1651                                        fid->fid, offset, rsize);
1652         } else {
1653                 if (data)
1654                         req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1655                                             offset, rsize, data);
1656                 else
1657                         req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1658                                             offset, rsize, udata);
1659         }
1660         if (IS_ERR(req)) {
1661                 err = PTR_ERR(req);
1662                 goto error;
1663         }
1664
1665         err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1666         if (err) {
1667                 trace_9p_protocol_dump(clnt, req->rc);
1668                 goto free_and_error;
1669         }
1670
1671         p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1672
1673         p9_free_req(clnt, req);
1674         return count;
1675
1676 free_and_error:
1677         p9_free_req(clnt, req);
1678 error:
1679         return err;
1680 }
1681 EXPORT_SYMBOL(p9_client_write);
1682
1683 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1684 {
1685         int err;
1686         struct p9_client *clnt;
1687         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1688         struct p9_req_t *req;
1689         u16 ignored;
1690
1691         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1692
1693         if (!ret)
1694                 return ERR_PTR(-ENOMEM);
1695
1696         err = 0;
1697         clnt = fid->clnt;
1698
1699         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1700         if (IS_ERR(req)) {
1701                 err = PTR_ERR(req);
1702                 goto error;
1703         }
1704
1705         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1706         if (err) {
1707                 trace_9p_protocol_dump(clnt, req->rc);
1708                 p9_free_req(clnt, req);
1709                 goto error;
1710         }
1711
1712         p9_debug(P9_DEBUG_9P,
1713                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1714                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1715                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1716                 "<<<    uid=%d gid=%d n_muid=%d\n",
1717                 ret->size, ret->type, ret->dev, ret->qid.type,
1718                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1719                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1720                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1721                 from_kuid(&init_user_ns, ret->n_uid),
1722                 from_kgid(&init_user_ns, ret->n_gid),
1723                 from_kuid(&init_user_ns, ret->n_muid));
1724
1725         p9_free_req(clnt, req);
1726         return ret;
1727
1728 error:
1729         kfree(ret);
1730         return ERR_PTR(err);
1731 }
1732 EXPORT_SYMBOL(p9_client_stat);
1733
1734 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1735                                                         u64 request_mask)
1736 {
1737         int err;
1738         struct p9_client *clnt;
1739         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1740                                                                 GFP_KERNEL);
1741         struct p9_req_t *req;
1742
1743         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1744                                                         fid->fid, request_mask);
1745
1746         if (!ret)
1747                 return ERR_PTR(-ENOMEM);
1748
1749         err = 0;
1750         clnt = fid->clnt;
1751
1752         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1753         if (IS_ERR(req)) {
1754                 err = PTR_ERR(req);
1755                 goto error;
1756         }
1757
1758         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1759         if (err) {
1760                 trace_9p_protocol_dump(clnt, req->rc);
1761                 p9_free_req(clnt, req);
1762                 goto error;
1763         }
1764
1765         p9_debug(P9_DEBUG_9P,
1766                 "<<< RGETATTR st_result_mask=%lld\n"
1767                 "<<< qid=%x.%llx.%x\n"
1768                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1769                 "<<< st_uid=%d st_gid=%d\n"
1770                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1771                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1772                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1773                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1774                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1775                 "<<< st_gen=%lld st_data_version=%lld",
1776                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1777                 ret->qid.version, ret->st_mode, ret->st_nlink,
1778                 from_kuid(&init_user_ns, ret->st_uid),
1779                 from_kgid(&init_user_ns, ret->st_gid),
1780                 ret->st_rdev, ret->st_size, ret->st_blksize,
1781                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1782                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1783                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1784                 ret->st_gen, ret->st_data_version);
1785
1786         p9_free_req(clnt, req);
1787         return ret;
1788
1789 error:
1790         kfree(ret);
1791         return ERR_PTR(err);
1792 }
1793 EXPORT_SYMBOL(p9_client_getattr_dotl);
1794
1795 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1796 {
1797         int ret;
1798
1799         /* NOTE: size shouldn't include its own length */
1800         /* size[2] type[2] dev[4] qid[13] */
1801         /* mode[4] atime[4] mtime[4] length[8]*/
1802         /* name[s] uid[s] gid[s] muid[s] */
1803         ret = 2+4+13+4+4+4+8+2+2+2+2;
1804
1805         if (wst->name)
1806                 ret += strlen(wst->name);
1807         if (wst->uid)
1808                 ret += strlen(wst->uid);
1809         if (wst->gid)
1810                 ret += strlen(wst->gid);
1811         if (wst->muid)
1812                 ret += strlen(wst->muid);
1813
1814         if ((proto_version == p9_proto_2000u) ||
1815                 (proto_version == p9_proto_2000L)) {
1816                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1817                 if (wst->extension)
1818                         ret += strlen(wst->extension);
1819         }
1820
1821         return ret;
1822 }
1823
1824 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1825 {
1826         int err;
1827         struct p9_req_t *req;
1828         struct p9_client *clnt;
1829
1830         err = 0;
1831         clnt = fid->clnt;
1832         wst->size = p9_client_statsize(wst, clnt->proto_version);
1833         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1834         p9_debug(P9_DEBUG_9P,
1835                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1836                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1837                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1838                 "     uid=%d gid=%d n_muid=%d\n",
1839                 wst->size, wst->type, wst->dev, wst->qid.type,
1840                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1841                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1842                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1843                 from_kuid(&init_user_ns, wst->n_uid),
1844                 from_kgid(&init_user_ns, wst->n_gid),
1845                 from_kuid(&init_user_ns, wst->n_muid));
1846
1847         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1848         if (IS_ERR(req)) {
1849                 err = PTR_ERR(req);
1850                 goto error;
1851         }
1852
1853         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1854
1855         p9_free_req(clnt, req);
1856 error:
1857         return err;
1858 }
1859 EXPORT_SYMBOL(p9_client_wstat);
1860
1861 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1862 {
1863         int err;
1864         struct p9_req_t *req;
1865         struct p9_client *clnt;
1866
1867         err = 0;
1868         clnt = fid->clnt;
1869         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1870         p9_debug(P9_DEBUG_9P,
1871                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1872                 "    atime_sec=%lld atime_nsec=%lld\n"
1873                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1874                 p9attr->valid, p9attr->mode,
1875                 from_kuid(&init_user_ns, p9attr->uid),
1876                 from_kgid(&init_user_ns, p9attr->gid),
1877                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1878                 p9attr->mtime_sec, p9attr->mtime_nsec);
1879
1880         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1881
1882         if (IS_ERR(req)) {
1883                 err = PTR_ERR(req);
1884                 goto error;
1885         }
1886         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1887         p9_free_req(clnt, req);
1888 error:
1889         return err;
1890 }
1891 EXPORT_SYMBOL(p9_client_setattr);
1892
1893 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1894 {
1895         int err;
1896         struct p9_req_t *req;
1897         struct p9_client *clnt;
1898
1899         err = 0;
1900         clnt = fid->clnt;
1901
1902         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1903
1904         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1905         if (IS_ERR(req)) {
1906                 err = PTR_ERR(req);
1907                 goto error;
1908         }
1909
1910         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1911                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1912                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1913         if (err) {
1914                 trace_9p_protocol_dump(clnt, req->rc);
1915                 p9_free_req(clnt, req);
1916                 goto error;
1917         }
1918
1919         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1920                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1921                 "fsid %llu namelen %ld\n",
1922                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1923                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1924                 sb->fsid, (long int)sb->namelen);
1925
1926         p9_free_req(clnt, req);
1927 error:
1928         return err;
1929 }
1930 EXPORT_SYMBOL(p9_client_statfs);
1931
1932 int p9_client_rename(struct p9_fid *fid,
1933                      struct p9_fid *newdirfid, const char *name)
1934 {
1935         int err;
1936         struct p9_req_t *req;
1937         struct p9_client *clnt;
1938
1939         err = 0;
1940         clnt = fid->clnt;
1941
1942         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1943                         fid->fid, newdirfid->fid, name);
1944
1945         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1946                         newdirfid->fid, name);
1947         if (IS_ERR(req)) {
1948                 err = PTR_ERR(req);
1949                 goto error;
1950         }
1951
1952         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1953
1954         p9_free_req(clnt, req);
1955 error:
1956         return err;
1957 }
1958 EXPORT_SYMBOL(p9_client_rename);
1959
1960 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1961                        struct p9_fid *newdirfid, const char *new_name)
1962 {
1963         int err;
1964         struct p9_req_t *req;
1965         struct p9_client *clnt;
1966
1967         err = 0;
1968         clnt = olddirfid->clnt;
1969
1970         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1971                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1972                    newdirfid->fid, new_name);
1973
1974         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1975                             old_name, newdirfid->fid, new_name);
1976         if (IS_ERR(req)) {
1977                 err = PTR_ERR(req);
1978                 goto error;
1979         }
1980
1981         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1982                    newdirfid->fid, new_name);
1983
1984         p9_free_req(clnt, req);
1985 error:
1986         return err;
1987 }
1988 EXPORT_SYMBOL(p9_client_renameat);
1989
1990 /*
1991  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1992  */
1993 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1994                                 const char *attr_name, u64 *attr_size)
1995 {
1996         int err;
1997         struct p9_req_t *req;
1998         struct p9_client *clnt;
1999         struct p9_fid *attr_fid;
2000
2001         err = 0;
2002         clnt = file_fid->clnt;
2003         attr_fid = p9_fid_create(clnt);
2004         if (IS_ERR(attr_fid)) {
2005                 err = PTR_ERR(attr_fid);
2006                 attr_fid = NULL;
2007                 goto error;
2008         }
2009         p9_debug(P9_DEBUG_9P,
2010                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2011                 file_fid->fid, attr_fid->fid, attr_name);
2012
2013         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2014                         file_fid->fid, attr_fid->fid, attr_name);
2015         if (IS_ERR(req)) {
2016                 err = PTR_ERR(req);
2017                 goto error;
2018         }
2019         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2020         if (err) {
2021                 trace_9p_protocol_dump(clnt, req->rc);
2022                 p9_free_req(clnt, req);
2023                 goto clunk_fid;
2024         }
2025         p9_free_req(clnt, req);
2026         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2027                 attr_fid->fid, *attr_size);
2028         return attr_fid;
2029 clunk_fid:
2030         p9_client_clunk(attr_fid);
2031         attr_fid = NULL;
2032 error:
2033         if (attr_fid && (attr_fid != file_fid))
2034                 p9_fid_destroy(attr_fid);
2035
2036         return ERR_PTR(err);
2037 }
2038 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2039
2040 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2041                         u64 attr_size, int flags)
2042 {
2043         int err;
2044         struct p9_req_t *req;
2045         struct p9_client *clnt;
2046
2047         p9_debug(P9_DEBUG_9P,
2048                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2049                 fid->fid, name, (long long)attr_size, flags);
2050         err = 0;
2051         clnt = fid->clnt;
2052         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2053                         fid->fid, name, attr_size, flags);
2054         if (IS_ERR(req)) {
2055                 err = PTR_ERR(req);
2056                 goto error;
2057         }
2058         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2059         p9_free_req(clnt, req);
2060 error:
2061         return err;
2062 }
2063 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2064
2065 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2066 {
2067         int err, rsize, non_zc = 0;
2068         struct p9_client *clnt;
2069         struct p9_req_t *req;
2070         char *dataptr;
2071
2072         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2073                                 fid->fid, (unsigned long long) offset, count);
2074
2075         err = 0;
2076         clnt = fid->clnt;
2077
2078         rsize = fid->iounit;
2079         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2080                 rsize = clnt->msize - P9_READDIRHDRSZ;
2081
2082         if (count < rsize)
2083                 rsize = count;
2084
2085         /* Don't bother zerocopy for small IO (< 1024) */
2086         if (clnt->trans_mod->zc_request && rsize > 1024) {
2087                 /*
2088                  * response header len is 11
2089                  * PDU Header(7) + IO Size (4)
2090                  */
2091                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, data, NULL, rsize, 0,
2092                                        11, 1, "dqd", fid->fid, offset, rsize);
2093         } else {
2094                 non_zc = 1;
2095                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2096                                     offset, rsize);
2097         }
2098         if (IS_ERR(req)) {
2099                 err = PTR_ERR(req);
2100                 goto error;
2101         }
2102
2103         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2104         if (err) {
2105                 trace_9p_protocol_dump(clnt, req->rc);
2106                 goto free_and_error;
2107         }
2108
2109         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2110
2111         if (non_zc)
2112                 memmove(data, dataptr, count);
2113
2114         p9_free_req(clnt, req);
2115         return count;
2116
2117 free_and_error:
2118         p9_free_req(clnt, req);
2119 error:
2120         return err;
2121 }
2122 EXPORT_SYMBOL(p9_client_readdir);
2123
2124 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2125                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2126 {
2127         int err;
2128         struct p9_client *clnt;
2129         struct p9_req_t *req;
2130
2131         err = 0;
2132         clnt = fid->clnt;
2133         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2134                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2135         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2136                 MAJOR(rdev), MINOR(rdev), gid);
2137         if (IS_ERR(req))
2138                 return PTR_ERR(req);
2139
2140         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2141         if (err) {
2142                 trace_9p_protocol_dump(clnt, req->rc);
2143                 goto error;
2144         }
2145         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2146                                 (unsigned long long)qid->path, qid->version);
2147
2148 error:
2149         p9_free_req(clnt, req);
2150         return err;
2151
2152 }
2153 EXPORT_SYMBOL(p9_client_mknod_dotl);
2154
2155 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2156                                 kgid_t gid, struct p9_qid *qid)
2157 {
2158         int err;
2159         struct p9_client *clnt;
2160         struct p9_req_t *req;
2161
2162         err = 0;
2163         clnt = fid->clnt;
2164         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2165                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2166         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2167                 gid);
2168         if (IS_ERR(req))
2169                 return PTR_ERR(req);
2170
2171         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2172         if (err) {
2173                 trace_9p_protocol_dump(clnt, req->rc);
2174                 goto error;
2175         }
2176         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2177                                 (unsigned long long)qid->path, qid->version);
2178
2179 error:
2180         p9_free_req(clnt, req);
2181         return err;
2182
2183 }
2184 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2185
2186 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2187 {
2188         int err;
2189         struct p9_client *clnt;
2190         struct p9_req_t *req;
2191
2192         err = 0;
2193         clnt = fid->clnt;
2194         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2195                         "start %lld length %lld proc_id %d client_id %s\n",
2196                         fid->fid, flock->type, flock->flags, flock->start,
2197                         flock->length, flock->proc_id, flock->client_id);
2198
2199         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2200                                 flock->flags, flock->start, flock->length,
2201                                         flock->proc_id, flock->client_id);
2202
2203         if (IS_ERR(req))
2204                 return PTR_ERR(req);
2205
2206         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2207         if (err) {
2208                 trace_9p_protocol_dump(clnt, req->rc);
2209                 goto error;
2210         }
2211         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2212 error:
2213         p9_free_req(clnt, req);
2214         return err;
2215
2216 }
2217 EXPORT_SYMBOL(p9_client_lock_dotl);
2218
2219 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2220 {
2221         int err;
2222         struct p9_client *clnt;
2223         struct p9_req_t *req;
2224
2225         err = 0;
2226         clnt = fid->clnt;
2227         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2228                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2229                 glock->start, glock->length, glock->proc_id, glock->client_id);
2230
2231         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2232                 glock->start, glock->length, glock->proc_id, glock->client_id);
2233
2234         if (IS_ERR(req))
2235                 return PTR_ERR(req);
2236
2237         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2238                         &glock->start, &glock->length, &glock->proc_id,
2239                         &glock->client_id);
2240         if (err) {
2241                 trace_9p_protocol_dump(clnt, req->rc);
2242                 goto error;
2243         }
2244         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2245                 "proc_id %d client_id %s\n", glock->type, glock->start,
2246                 glock->length, glock->proc_id, glock->client_id);
2247 error:
2248         p9_free_req(clnt, req);
2249         return err;
2250 }
2251 EXPORT_SYMBOL(p9_client_getlock_dotl);
2252
2253 int p9_client_readlink(struct p9_fid *fid, char **target)
2254 {
2255         int err;
2256         struct p9_client *clnt;
2257         struct p9_req_t *req;
2258
2259         err = 0;
2260         clnt = fid->clnt;
2261         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2262
2263         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2264         if (IS_ERR(req))
2265                 return PTR_ERR(req);
2266
2267         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2268         if (err) {
2269                 trace_9p_protocol_dump(clnt, req->rc);
2270                 goto error;
2271         }
2272         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2273 error:
2274         p9_free_req(clnt, req);
2275         return err;
2276 }
2277 EXPORT_SYMBOL(p9_client_readlink);