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                 break;
 963         }
 964
 965         if (IS_ERR(req))
 966                 return PTR_ERR(req);
 967
 968         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 969         if (err) {
 970                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 971                 trace_9p_protocol_dump(c, req->rc);
 972                 goto error;
 973         }
 974
 975         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 976         if (!strncmp(version, "9P2000.L", 8))
 977                 c->proto_version = p9_proto_2000L;
 978         else if (!strncmp(version, "9P2000.u", 8))
 979                 c->proto_version = p9_proto_2000u;
 980         else if (!strncmp(version, "9P2000", 6))
 981                 c->proto_version = p9_proto_legacy;
 982         else {
 983                 err = -EREMOTEIO;
 984                 goto error;
 985         }
 986
 987         if (msize < c->msize)
 988                 c->msize = msize;
 989
 990 error:
 991         kfree(version);
 992         p9_free_req(c, req);
 993
 994         return err;
 995 }
 996
 997 struct p9_client *p9_client_create(const char *dev_name, char *options)
 998 {
 999         int err;
1000         struct p9_client *clnt;
1001         char *client_id;
1002
1003         err = 0;
1004         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1005         if (!clnt)
1006                 return ERR_PTR(-ENOMEM);
1007
1008         clnt->trans_mod = NULL;
1009         clnt->trans = NULL;
1010
1011         client_id = utsname()->nodename;
1012         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1013
1014         spin_lock_init(&clnt->lock);
1015         INIT_LIST_HEAD(&clnt->fidlist);
1016
1017         err = p9_tag_init(clnt);
1018         if (err < 0)
1019                 goto free_client;
1020
1021         err = parse_opts(options, clnt);
1022         if (err < 0)
1023                 goto destroy_tagpool;
1024
1025         if (!clnt->trans_mod)
1026                 clnt->trans_mod = v9fs_get_default_trans();
1027
1028         if (clnt->trans_mod == NULL) {
1029                 err = -EPROTONOSUPPORT;
1030                 p9_debug(P9_DEBUG_ERROR,
1031                          "No transport defined or default transport\n");
1032                 goto destroy_tagpool;
1033         }
1034
1035         clnt->fidpool = p9_idpool_create();
1036         if (IS_ERR(clnt->fidpool)) {
1037                 err = PTR_ERR(clnt->fidpool);
1038                 goto put_trans;
1039         }
1040
1041         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1042                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1043
1044         err = clnt->trans_mod->create(clnt, dev_name, options);
1045         if (err)
1046                 goto destroy_fidpool;
1047
1048         if (clnt->msize > clnt->trans_mod->maxsize)
1049                 clnt->msize = clnt->trans_mod->maxsize;
1050
1051         err = p9_client_version(clnt);
1052         if (err)
1053                 goto close_trans;
1054
1055         return clnt;
1056
1057 close_trans:
1058         clnt->trans_mod->close(clnt);
1059 destroy_fidpool:
1060         p9_idpool_destroy(clnt->fidpool);
1061 put_trans:
1062         v9fs_put_trans(clnt->trans_mod);
1063 destroy_tagpool:
1064         p9_idpool_destroy(clnt->tagpool);
1065 free_client:
1066         kfree(clnt);
1067         return ERR_PTR(err);
1068 }
1069 EXPORT_SYMBOL(p9_client_create);
1070
1071 void p9_client_destroy(struct p9_client *clnt)
1072 {
1073         struct p9_fid *fid, *fidptr;
1074
1075         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1076
1077         if (clnt->trans_mod)
1078                 clnt->trans_mod->close(clnt);
1079
1080         v9fs_put_trans(clnt->trans_mod);
1081
1082         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1083                 pr_info("Found fid %d not clunked\n", fid->fid);
1084                 p9_fid_destroy(fid);
1085         }
1086
1087         if (clnt->fidpool)
1088                 p9_idpool_destroy(clnt->fidpool);
1089
1090         p9_tag_cleanup(clnt);
1091
1092         kfree(clnt);
1093 }
1094 EXPORT_SYMBOL(p9_client_destroy);
1095
1096 void p9_client_disconnect(struct p9_client *clnt)
1097 {
1098         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1099         clnt->status = Disconnected;
1100 }
1101 EXPORT_SYMBOL(p9_client_disconnect);
1102
1103 void p9_client_begin_disconnect(struct p9_client *clnt)
1104 {
1105         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1106         clnt->status = BeginDisconnect;
1107 }
1108 EXPORT_SYMBOL(p9_client_begin_disconnect);
1109
1110 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1111         char *uname, kuid_t n_uname, char *aname)
1112 {
1113         int err = 0;
1114         struct p9_req_t *req;
1115         struct p9_fid *fid;
1116         struct p9_qid qid;
1117
1118
1119         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1120                  afid ? afid->fid : -1, uname, aname);
1121         fid = p9_fid_create(clnt);
1122         if (IS_ERR(fid)) {
1123                 err = PTR_ERR(fid);
1124                 fid = NULL;
1125                 goto error;
1126         }
1127
1128         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1129                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1130         if (IS_ERR(req)) {
1131                 err = PTR_ERR(req);
1132                 goto error;
1133         }
1134
1135         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1136         if (err) {
1137                 trace_9p_protocol_dump(clnt, req->rc);
1138                 p9_free_req(clnt, req);
1139                 goto error;
1140         }
1141
1142         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1143                  qid.type, (unsigned long long)qid.path, qid.version);
1144
1145         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1146
1147         p9_free_req(clnt, req);
1148         return fid;
1149
1150 error:
1151         if (fid)
1152                 p9_fid_destroy(fid);
1153         return ERR_PTR(err);
1154 }
1155 EXPORT_SYMBOL(p9_client_attach);
1156
1157 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1158                 char **wnames, int clone)
1159 {
1160         int err;
1161         struct p9_client *clnt;
1162         struct p9_fid *fid;
1163         struct p9_qid *wqids;
1164         struct p9_req_t *req;
1165         uint16_t nwqids, count;
1166
1167         err = 0;
1168         wqids = NULL;
1169         clnt = oldfid->clnt;
1170         if (clone) {
1171                 fid = p9_fid_create(clnt);
1172                 if (IS_ERR(fid)) {
1173                         err = PTR_ERR(fid);
1174                         fid = NULL;
1175                         goto error;
1176                 }
1177
1178                 fid->uid = oldfid->uid;
1179         } else
1180                 fid = oldfid;
1181
1182
1183         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1184                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1185
1186         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1187                                                                 nwname, wnames);
1188         if (IS_ERR(req)) {
1189                 err = PTR_ERR(req);
1190                 goto error;
1191         }
1192
1193         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1194         if (err) {
1195                 trace_9p_protocol_dump(clnt, req->rc);
1196                 p9_free_req(clnt, req);
1197                 goto clunk_fid;
1198         }
1199         p9_free_req(clnt, req);
1200
1201         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1202
1203         if (nwqids != nwname) {
1204                 err = -ENOENT;
1205                 goto clunk_fid;
1206         }
1207
1208         for (count = 0; count < nwqids; count++)
1209                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1210                         count, wqids[count].type,
1211                         (unsigned long long)wqids[count].path,
1212                         wqids[count].version);
1213
1214         if (nwname)
1215                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1216         else
1217                 fid->qid = oldfid->qid;
1218
1219         kfree(wqids);
1220         return fid;
1221
1222 clunk_fid:
1223         kfree(wqids);
1224         p9_client_clunk(fid);
1225         fid = NULL;
1226
1227 error:
1228         if (fid && (fid != oldfid))
1229                 p9_fid_destroy(fid);
1230
1231         return ERR_PTR(err);
1232 }
1233 EXPORT_SYMBOL(p9_client_walk);
1234
1235 int p9_client_open(struct p9_fid *fid, int mode)
1236 {
1237         int err;
1238         struct p9_client *clnt;
1239         struct p9_req_t *req;
1240         struct p9_qid qid;
1241         int iounit;
1242
1243         clnt = fid->clnt;
1244         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1245                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1246         err = 0;
1247
1248         if (fid->mode != -1)
1249                 return -EINVAL;
1250
1251         if (p9_is_proto_dotl(clnt))
1252                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1253         else
1254                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1255         if (IS_ERR(req)) {
1256                 err = PTR_ERR(req);
1257                 goto error;
1258         }
1259
1260         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1261         if (err) {
1262                 trace_9p_protocol_dump(clnt, req->rc);
1263                 goto free_and_error;
1264         }
1265
1266         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1267                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1268                 (unsigned long long)qid.path, qid.version, iounit);
1269
1270         fid->mode = mode;
1271         fid->iounit = iounit;
1272
1273 free_and_error:
1274         p9_free_req(clnt, req);
1275 error:
1276         return err;
1277 }
1278 EXPORT_SYMBOL(p9_client_open);
1279
1280 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1281                 kgid_t gid, struct p9_qid *qid)
1282 {
1283         int err = 0;
1284         struct p9_client *clnt;
1285         struct p9_req_t *req;
1286         int iounit;
1287
1288         p9_debug(P9_DEBUG_9P,
1289                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1290                         ofid->fid, name, flags, mode,
1291                         from_kgid(&init_user_ns, gid));
1292         clnt = ofid->clnt;
1293
1294         if (ofid->mode != -1)
1295                 return -EINVAL;
1296
1297         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1298                         mode, gid);
1299         if (IS_ERR(req)) {
1300                 err = PTR_ERR(req);
1301                 goto error;
1302         }
1303
1304         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1305         if (err) {
1306                 trace_9p_protocol_dump(clnt, req->rc);
1307                 goto free_and_error;
1308         }
1309
1310         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1311                         qid->type,
1312                         (unsigned long long)qid->path,
1313                         qid->version, iounit);
1314
1315         ofid->mode = mode;
1316         ofid->iounit = iounit;
1317
1318 free_and_error:
1319         p9_free_req(clnt, req);
1320 error:
1321         return err;
1322 }
1323 EXPORT_SYMBOL(p9_client_create_dotl);
1324
1325 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1326                      char *extension)
1327 {
1328         int err;
1329         struct p9_client *clnt;
1330         struct p9_req_t *req;
1331         struct p9_qid qid;
1332         int iounit;
1333
1334         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1335                                                 fid->fid, name, perm, mode);
1336         err = 0;
1337         clnt = fid->clnt;
1338
1339         if (fid->mode != -1)
1340                 return -EINVAL;
1341
1342         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1343                                 mode, extension);
1344         if (IS_ERR(req)) {
1345                 err = PTR_ERR(req);
1346                 goto error;
1347         }
1348
1349         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1350         if (err) {
1351                 trace_9p_protocol_dump(clnt, req->rc);
1352                 goto free_and_error;
1353         }
1354
1355         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1356                                 qid.type,
1357                                 (unsigned long long)qid.path,
1358                                 qid.version, iounit);
1359
1360         fid->mode = mode;
1361         fid->iounit = iounit;
1362
1363 free_and_error:
1364         p9_free_req(clnt, req);
1365 error:
1366         return err;
1367 }
1368 EXPORT_SYMBOL(p9_client_fcreate);
1369
1370 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
1371                 struct p9_qid *qid)
1372 {
1373         int err = 0;
1374         struct p9_client *clnt;
1375         struct p9_req_t *req;
1376
1377         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1378                         dfid->fid, name, symtgt);
1379         clnt = dfid->clnt;
1380
1381         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1382                         gid);
1383         if (IS_ERR(req)) {
1384                 err = PTR_ERR(req);
1385                 goto error;
1386         }
1387
1388         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1389         if (err) {
1390                 trace_9p_protocol_dump(clnt, req->rc);
1391                 goto free_and_error;
1392         }
1393
1394         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1395                         qid->type, (unsigned long long)qid->path, qid->version);
1396
1397 free_and_error:
1398         p9_free_req(clnt, req);
1399 error:
1400         return err;
1401 }
1402 EXPORT_SYMBOL(p9_client_symlink);
1403
1404 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1405 {
1406         struct p9_client *clnt;
1407         struct p9_req_t *req;
1408
1409         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1410                         dfid->fid, oldfid->fid, newname);
1411         clnt = dfid->clnt;
1412         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1413                         newname);
1414         if (IS_ERR(req))
1415                 return PTR_ERR(req);
1416
1417         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1418         p9_free_req(clnt, req);
1419         return 0;
1420 }
1421 EXPORT_SYMBOL(p9_client_link);
1422
1423 int p9_client_fsync(struct p9_fid *fid, int datasync)
1424 {
1425         int err;
1426         struct p9_client *clnt;
1427         struct p9_req_t *req;
1428
1429         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1430                         fid->fid, datasync);
1431         err = 0;
1432         clnt = fid->clnt;
1433
1434         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1435         if (IS_ERR(req)) {
1436                 err = PTR_ERR(req);
1437                 goto error;
1438         }
1439
1440         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1441
1442         p9_free_req(clnt, req);
1443
1444 error:
1445         return err;
1446 }
1447 EXPORT_SYMBOL(p9_client_fsync);
1448
1449 int p9_client_clunk(struct p9_fid *fid)
1450 {
1451         int err;
1452         struct p9_client *clnt;
1453         struct p9_req_t *req;
1454         int retries = 0;
1455
1456         if (!fid) {
1457                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1458                         __func__, task_pid_nr(current));
1459                 dump_stack();
1460                 return 0;
1461         }
1462
1463 again:
1464         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1465                                                                 retries);
1466         err = 0;
1467         clnt = fid->clnt;
1468
1469         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1470         if (IS_ERR(req)) {
1471                 err = PTR_ERR(req);
1472                 goto error;
1473         }
1474
1475         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1476
1477         p9_free_req(clnt, req);
1478 error:
1479         /*
1480          * Fid is not valid even after a failed clunk
1481          * If interrupted, retry once then give up and
1482          * leak fid until umount.
1483          */
1484         if (err == -ERESTARTSYS) {
1485                 if (retries++ == 0)
1486                         goto again;
1487         } else
1488                 p9_fid_destroy(fid);
1489         return err;
1490 }
1491 EXPORT_SYMBOL(p9_client_clunk);
1492
1493 int p9_client_remove(struct p9_fid *fid)
1494 {
1495         int err;
1496         struct p9_client *clnt;
1497         struct p9_req_t *req;
1498
1499         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1500         err = 0;
1501         clnt = fid->clnt;
1502
1503         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1504         if (IS_ERR(req)) {
1505                 err = PTR_ERR(req);
1506                 goto error;
1507         }
1508
1509         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1510
1511         p9_free_req(clnt, req);
1512 error:
1513         if (err == -ERESTARTSYS)
1514                 p9_client_clunk(fid);
1515         else
1516                 p9_fid_destroy(fid);
1517         return err;
1518 }
1519 EXPORT_SYMBOL(p9_client_remove);
1520
1521 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1522 {
1523         int err = 0;
1524         struct p9_req_t *req;
1525         struct p9_client *clnt;
1526
1527         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1528                    dfid->fid, name, flags);
1529
1530         clnt = dfid->clnt;
1531         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1532         if (IS_ERR(req)) {
1533                 err = PTR_ERR(req);
1534                 goto error;
1535         }
1536         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1537
1538         p9_free_req(clnt, req);
1539 error:
1540         return err;
1541 }
1542 EXPORT_SYMBOL(p9_client_unlinkat);
1543
1544 int
1545 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1546                                                                 u32 count)
1547 {
1548         char *dataptr;
1549         int kernel_buf = 0;
1550         struct p9_req_t *req;
1551         struct p9_client *clnt;
1552         int err, rsize, non_zc = 0;
1553
1554
1555         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1556                    fid->fid, (unsigned long long) offset, count);
1557         err = 0;
1558         clnt = fid->clnt;
1559
1560         rsize = fid->iounit;
1561         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1562                 rsize = clnt->msize - P9_IOHDRSZ;
1563
1564         if (count < rsize)
1565                 rsize = count;
1566
1567         /* Don't bother zerocopy for small IO (< 1024) */
1568         if (clnt->trans_mod->zc_request && rsize > 1024) {
1569                 char *indata;
1570                 if (data) {
1571                         kernel_buf = 1;
1572                         indata = data;
1573                 } else
1574                         indata = (__force char *)udata;
1575                 /*
1576                  * response header len is 11
1577                  * PDU Header(7) + IO Size (4)
1578                  */
1579                 req = p9_client_zc_rpc(clnt, P9_TREAD, indata, NULL, rsize, 0,
1580                                        11, kernel_buf, "dqd", fid->fid,
1581                                        offset, rsize);
1582         } else {
1583                 non_zc = 1;
1584                 req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1585                                     rsize);
1586         }
1587         if (IS_ERR(req)) {
1588                 err = PTR_ERR(req);
1589                 goto error;
1590         }
1591
1592         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1593         if (err) {
1594                 trace_9p_protocol_dump(clnt, req->rc);
1595                 goto free_and_error;
1596         }
1597
1598         p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1599
1600         if (non_zc) {
1601                 if (data) {
1602                         memmove(data, dataptr, count);
1603                 } else {
1604                         err = copy_to_user(udata, dataptr, count);
1605                         if (err) {
1606                                 err = -EFAULT;
1607                                 goto free_and_error;
1608                         }
1609                 }
1610         }
1611         p9_free_req(clnt, req);
1612         return count;
1613
1614 free_and_error:
1615         p9_free_req(clnt, req);
1616 error:
1617         return err;
1618 }
1619 EXPORT_SYMBOL(p9_client_read);
1620
1621 int
1622 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1623                                                         u64 offset, u32 count)
1624 {
1625         int err, rsize;
1626         int kernel_buf = 0;
1627         struct p9_client *clnt;
1628         struct p9_req_t *req;
1629
1630         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1631                                 fid->fid, (unsigned long long) offset, count);
1632         err = 0;
1633         clnt = fid->clnt;
1634
1635         rsize = fid->iounit;
1636         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1637                 rsize = clnt->msize - P9_IOHDRSZ;
1638
1639         if (count < rsize)
1640                 rsize = count;
1641
1642         /* Don't bother zerocopy for small IO (< 1024) */
1643         if (clnt->trans_mod->zc_request && rsize > 1024) {
1644                 char *odata;
1645                 if (data) {
1646                         kernel_buf = 1;
1647                         odata = data;
1648                 } else
1649                         odata = (char *)udata;
1650                 req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, odata, 0, rsize,
1651                                        P9_ZC_HDR_SZ, kernel_buf, "dqd",
1652                                        fid->fid, offset, rsize);
1653         } else {
1654                 if (data)
1655                         req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1656                                             offset, rsize, data);
1657                 else
1658                         req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1659                                             offset, rsize, udata);
1660         }
1661         if (IS_ERR(req)) {
1662                 err = PTR_ERR(req);
1663                 goto error;
1664         }
1665
1666         err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1667         if (err) {
1668                 trace_9p_protocol_dump(clnt, req->rc);
1669                 goto free_and_error;
1670         }
1671
1672         p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1673
1674         p9_free_req(clnt, req);
1675         return count;
1676
1677 free_and_error:
1678         p9_free_req(clnt, req);
1679 error:
1680         return err;
1681 }
1682 EXPORT_SYMBOL(p9_client_write);
1683
1684 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1685 {
1686         int err;
1687         struct p9_client *clnt;
1688         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1689         struct p9_req_t *req;
1690         u16 ignored;
1691
1692         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1693
1694         if (!ret)
1695                 return ERR_PTR(-ENOMEM);
1696
1697         err = 0;
1698         clnt = fid->clnt;
1699
1700         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1701         if (IS_ERR(req)) {
1702                 err = PTR_ERR(req);
1703                 goto error;
1704         }
1705
1706         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1707         if (err) {
1708                 trace_9p_protocol_dump(clnt, req->rc);
1709                 p9_free_req(clnt, req);
1710                 goto error;
1711         }
1712
1713         p9_debug(P9_DEBUG_9P,
1714                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1715                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1716                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1717                 "<<<    uid=%d gid=%d n_muid=%d\n",
1718                 ret->size, ret->type, ret->dev, ret->qid.type,
1719                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1720                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1721                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1722                 from_kuid(&init_user_ns, ret->n_uid),
1723                 from_kgid(&init_user_ns, ret->n_gid),
1724                 from_kuid(&init_user_ns, ret->n_muid));
1725
1726         p9_free_req(clnt, req);
1727         return ret;
1728
1729 error:
1730         kfree(ret);
1731         return ERR_PTR(err);
1732 }
1733 EXPORT_SYMBOL(p9_client_stat);
1734
1735 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1736                                                         u64 request_mask)
1737 {
1738         int err;
1739         struct p9_client *clnt;
1740         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1741                                                                 GFP_KERNEL);
1742         struct p9_req_t *req;
1743
1744         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1745                                                         fid->fid, request_mask);
1746
1747         if (!ret)
1748                 return ERR_PTR(-ENOMEM);
1749
1750         err = 0;
1751         clnt = fid->clnt;
1752
1753         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1754         if (IS_ERR(req)) {
1755                 err = PTR_ERR(req);
1756                 goto error;
1757         }
1758
1759         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1760         if (err) {
1761                 trace_9p_protocol_dump(clnt, req->rc);
1762                 p9_free_req(clnt, req);
1763                 goto error;
1764         }
1765
1766         p9_debug(P9_DEBUG_9P,
1767                 "<<< RGETATTR st_result_mask=%lld\n"
1768                 "<<< qid=%x.%llx.%x\n"
1769                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1770                 "<<< st_uid=%d st_gid=%d\n"
1771                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1772                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1773                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1774                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1775                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1776                 "<<< st_gen=%lld st_data_version=%lld",
1777                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1778                 ret->qid.version, ret->st_mode, ret->st_nlink,
1779                 from_kuid(&init_user_ns, ret->st_uid),
1780                 from_kgid(&init_user_ns, ret->st_gid),
1781                 ret->st_rdev, ret->st_size, ret->st_blksize,
1782                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1783                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1784                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1785                 ret->st_gen, ret->st_data_version);
1786
1787         p9_free_req(clnt, req);
1788         return ret;
1789
1790 error:
1791         kfree(ret);
1792         return ERR_PTR(err);
1793 }
1794 EXPORT_SYMBOL(p9_client_getattr_dotl);
1795
1796 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1797 {
1798         int ret;
1799
1800         /* NOTE: size shouldn't include its own length */
1801         /* size[2] type[2] dev[4] qid[13] */
1802         /* mode[4] atime[4] mtime[4] length[8]*/
1803         /* name[s] uid[s] gid[s] muid[s] */
1804         ret = 2+4+13+4+4+4+8+2+2+2+2;
1805
1806         if (wst->name)
1807                 ret += strlen(wst->name);
1808         if (wst->uid)
1809                 ret += strlen(wst->uid);
1810         if (wst->gid)
1811                 ret += strlen(wst->gid);
1812         if (wst->muid)
1813                 ret += strlen(wst->muid);
1814
1815         if ((proto_version == p9_proto_2000u) ||
1816                 (proto_version == p9_proto_2000L)) {
1817                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1818                 if (wst->extension)
1819                         ret += strlen(wst->extension);
1820         }
1821
1822         return ret;
1823 }
1824
1825 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1826 {
1827         int err;
1828         struct p9_req_t *req;
1829         struct p9_client *clnt;
1830
1831         err = 0;
1832         clnt = fid->clnt;
1833         wst->size = p9_client_statsize(wst, clnt->proto_version);
1834         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1835         p9_debug(P9_DEBUG_9P,
1836                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1837                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1838                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1839                 "     uid=%d gid=%d n_muid=%d\n",
1840                 wst->size, wst->type, wst->dev, wst->qid.type,
1841                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1842                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1843                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1844                 from_kuid(&init_user_ns, wst->n_uid),
1845                 from_kgid(&init_user_ns, wst->n_gid),
1846                 from_kuid(&init_user_ns, wst->n_muid));
1847
1848         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1849         if (IS_ERR(req)) {
1850                 err = PTR_ERR(req);
1851                 goto error;
1852         }
1853
1854         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1855
1856         p9_free_req(clnt, req);
1857 error:
1858         return err;
1859 }
1860 EXPORT_SYMBOL(p9_client_wstat);
1861
1862 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1863 {
1864         int err;
1865         struct p9_req_t *req;
1866         struct p9_client *clnt;
1867
1868         err = 0;
1869         clnt = fid->clnt;
1870         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1871         p9_debug(P9_DEBUG_9P,
1872                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1873                 "    atime_sec=%lld atime_nsec=%lld\n"
1874                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1875                 p9attr->valid, p9attr->mode,
1876                 from_kuid(&init_user_ns, p9attr->uid),
1877                 from_kgid(&init_user_ns, p9attr->gid),
1878                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1879                 p9attr->mtime_sec, p9attr->mtime_nsec);
1880
1881         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1882
1883         if (IS_ERR(req)) {
1884                 err = PTR_ERR(req);
1885                 goto error;
1886         }
1887         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1888         p9_free_req(clnt, req);
1889 error:
1890         return err;
1891 }
1892 EXPORT_SYMBOL(p9_client_setattr);
1893
1894 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1895 {
1896         int err;
1897         struct p9_req_t *req;
1898         struct p9_client *clnt;
1899
1900         err = 0;
1901         clnt = fid->clnt;
1902
1903         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1904
1905         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1906         if (IS_ERR(req)) {
1907                 err = PTR_ERR(req);
1908                 goto error;
1909         }
1910
1911         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1912                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1913                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1914         if (err) {
1915                 trace_9p_protocol_dump(clnt, req->rc);
1916                 p9_free_req(clnt, req);
1917                 goto error;
1918         }
1919
1920         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1921                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1922                 "fsid %llu namelen %ld\n",
1923                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1924                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1925                 sb->fsid, (long int)sb->namelen);
1926
1927         p9_free_req(clnt, req);
1928 error:
1929         return err;
1930 }
1931 EXPORT_SYMBOL(p9_client_statfs);
1932
1933 int p9_client_rename(struct p9_fid *fid,
1934                      struct p9_fid *newdirfid, const char *name)
1935 {
1936         int err;
1937         struct p9_req_t *req;
1938         struct p9_client *clnt;
1939
1940         err = 0;
1941         clnt = fid->clnt;
1942
1943         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1944                         fid->fid, newdirfid->fid, name);
1945
1946         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1947                         newdirfid->fid, name);
1948         if (IS_ERR(req)) {
1949                 err = PTR_ERR(req);
1950                 goto error;
1951         }
1952
1953         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1954
1955         p9_free_req(clnt, req);
1956 error:
1957         return err;
1958 }
1959 EXPORT_SYMBOL(p9_client_rename);
1960
1961 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1962                        struct p9_fid *newdirfid, const char *new_name)
1963 {
1964         int err;
1965         struct p9_req_t *req;
1966         struct p9_client *clnt;
1967
1968         err = 0;
1969         clnt = olddirfid->clnt;
1970
1971         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1972                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1973                    newdirfid->fid, new_name);
1974
1975         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1976                             old_name, newdirfid->fid, new_name);
1977         if (IS_ERR(req)) {
1978                 err = PTR_ERR(req);
1979                 goto error;
1980         }
1981
1982         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1983                    newdirfid->fid, new_name);
1984
1985         p9_free_req(clnt, req);
1986 error:
1987         return err;
1988 }
1989 EXPORT_SYMBOL(p9_client_renameat);
1990
1991 /*
1992  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1993  */
1994 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1995                                 const char *attr_name, u64 *attr_size)
1996 {
1997         int err;
1998         struct p9_req_t *req;
1999         struct p9_client *clnt;
2000         struct p9_fid *attr_fid;
2001
2002         err = 0;
2003         clnt = file_fid->clnt;
2004         attr_fid = p9_fid_create(clnt);
2005         if (IS_ERR(attr_fid)) {
2006                 err = PTR_ERR(attr_fid);
2007                 attr_fid = NULL;
2008                 goto error;
2009         }
2010         p9_debug(P9_DEBUG_9P,
2011                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2012                 file_fid->fid, attr_fid->fid, attr_name);
2013
2014         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2015                         file_fid->fid, attr_fid->fid, attr_name);
2016         if (IS_ERR(req)) {
2017                 err = PTR_ERR(req);
2018                 goto error;
2019         }
2020         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2021         if (err) {
2022                 trace_9p_protocol_dump(clnt, req->rc);
2023                 p9_free_req(clnt, req);
2024                 goto clunk_fid;
2025         }
2026         p9_free_req(clnt, req);
2027         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2028                 attr_fid->fid, *attr_size);
2029         return attr_fid;
2030 clunk_fid:
2031         p9_client_clunk(attr_fid);
2032         attr_fid = NULL;
2033 error:
2034         if (attr_fid && (attr_fid != file_fid))
2035                 p9_fid_destroy(attr_fid);
2036
2037         return ERR_PTR(err);
2038 }
2039 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2040
2041 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2042                         u64 attr_size, int flags)
2043 {
2044         int err;
2045         struct p9_req_t *req;
2046         struct p9_client *clnt;
2047
2048         p9_debug(P9_DEBUG_9P,
2049                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2050                 fid->fid, name, (long long)attr_size, flags);
2051         err = 0;
2052         clnt = fid->clnt;
2053         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2054                         fid->fid, name, attr_size, flags);
2055         if (IS_ERR(req)) {
2056                 err = PTR_ERR(req);
2057                 goto error;
2058         }
2059         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2060         p9_free_req(clnt, req);
2061 error:
2062         return err;
2063 }
2064 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2065
2066 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2067 {
2068         int err, rsize, non_zc = 0;
2069         struct p9_client *clnt;
2070         struct p9_req_t *req;
2071         char *dataptr;
2072
2073         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2074                                 fid->fid, (unsigned long long) offset, count);
2075
2076         err = 0;
2077         clnt = fid->clnt;
2078
2079         rsize = fid->iounit;
2080         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2081                 rsize = clnt->msize - P9_READDIRHDRSZ;
2082
2083         if (count < rsize)
2084                 rsize = count;
2085
2086         /* Don't bother zerocopy for small IO (< 1024) */
2087         if (clnt->trans_mod->zc_request && rsize > 1024) {
2088                 /*
2089                  * response header len is 11
2090                  * PDU Header(7) + IO Size (4)
2091                  */
2092                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, data, NULL, rsize, 0,
2093                                        11, 1, "dqd", fid->fid, offset, rsize);
2094         } else {
2095                 non_zc = 1;
2096                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2097                                     offset, rsize);
2098         }
2099         if (IS_ERR(req)) {
2100                 err = PTR_ERR(req);
2101                 goto error;
2102         }
2103
2104         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2105         if (err) {
2106                 trace_9p_protocol_dump(clnt, req->rc);
2107                 goto free_and_error;
2108         }
2109
2110         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2111
2112         if (non_zc)
2113                 memmove(data, dataptr, count);
2114
2115         p9_free_req(clnt, req);
2116         return count;
2117
2118 free_and_error:
2119         p9_free_req(clnt, req);
2120 error:
2121         return err;
2122 }
2123 EXPORT_SYMBOL(p9_client_readdir);
2124
2125 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2126                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2127 {
2128         int err;
2129         struct p9_client *clnt;
2130         struct p9_req_t *req;
2131
2132         err = 0;
2133         clnt = fid->clnt;
2134         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2135                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2136         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2137                 MAJOR(rdev), MINOR(rdev), gid);
2138         if (IS_ERR(req))
2139                 return PTR_ERR(req);
2140
2141         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2142         if (err) {
2143                 trace_9p_protocol_dump(clnt, req->rc);
2144                 goto error;
2145         }
2146         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2147                                 (unsigned long long)qid->path, qid->version);
2148
2149 error:
2150         p9_free_req(clnt, req);
2151         return err;
2152
2153 }
2154 EXPORT_SYMBOL(p9_client_mknod_dotl);
2155
2156 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2157                                 kgid_t gid, struct p9_qid *qid)
2158 {
2159         int err;
2160         struct p9_client *clnt;
2161         struct p9_req_t *req;
2162
2163         err = 0;
2164         clnt = fid->clnt;
2165         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2166                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2167         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2168                 gid);
2169         if (IS_ERR(req))
2170                 return PTR_ERR(req);
2171
2172         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2173         if (err) {
2174                 trace_9p_protocol_dump(clnt, req->rc);
2175                 goto error;
2176         }
2177         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2178                                 (unsigned long long)qid->path, qid->version);
2179
2180 error:
2181         p9_free_req(clnt, req);
2182         return err;
2183
2184 }
2185 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2186
2187 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2188 {
2189         int err;
2190         struct p9_client *clnt;
2191         struct p9_req_t *req;
2192
2193         err = 0;
2194         clnt = fid->clnt;
2195         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2196                         "start %lld length %lld proc_id %d client_id %s\n",
2197                         fid->fid, flock->type, flock->flags, flock->start,
2198                         flock->length, flock->proc_id, flock->client_id);
2199
2200         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2201                                 flock->flags, flock->start, flock->length,
2202                                         flock->proc_id, flock->client_id);
2203
2204         if (IS_ERR(req))
2205                 return PTR_ERR(req);
2206
2207         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2208         if (err) {
2209                 trace_9p_protocol_dump(clnt, req->rc);
2210                 goto error;
2211         }
2212         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2213 error:
2214         p9_free_req(clnt, req);
2215         return err;
2216
2217 }
2218 EXPORT_SYMBOL(p9_client_lock_dotl);
2219
2220 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2221 {
2222         int err;
2223         struct p9_client *clnt;
2224         struct p9_req_t *req;
2225
2226         err = 0;
2227         clnt = fid->clnt;
2228         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2229                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2230                 glock->start, glock->length, glock->proc_id, glock->client_id);
2231
2232         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2233                 glock->start, glock->length, glock->proc_id, glock->client_id);
2234
2235         if (IS_ERR(req))
2236                 return PTR_ERR(req);
2237
2238         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2239                         &glock->start, &glock->length, &glock->proc_id,
2240                         &glock->client_id);
2241         if (err) {
2242                 trace_9p_protocol_dump(clnt, req->rc);
2243                 goto error;
2244         }
2245         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2246                 "proc_id %d client_id %s\n", glock->type, glock->start,
2247                 glock->length, glock->proc_id, glock->client_id);
2248 error:
2249         p9_free_req(clnt, req);
2250         return err;
2251 }
2252 EXPORT_SYMBOL(p9_client_getlock_dotl);
2253
2254 int p9_client_readlink(struct p9_fid *fid, char **target)
2255 {
2256         int err;
2257         struct p9_client *clnt;
2258         struct p9_req_t *req;
2259
2260         err = 0;
2261         clnt = fid->clnt;
2262         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2263
2264         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2265         if (IS_ERR(req))
2266                 return PTR_ERR(req);
2267
2268         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2269         if (err) {
2270                 trace_9p_protocol_dump(clnt, req->rc);
2271                 goto error;
2272         }
2273         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2274 error:
2275         p9_free_req(clnt, req);
2276         return err;
2277 }
2278 EXPORT_SYMBOL(p9_client_readlink);