net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #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/signal.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/uio.h>
  38 #include <net/9p/9p.h>
  39 #include <linux/parser.h>
  40 #include <linux/seq_file.h>
  41 #include <net/9p/client.h>
  42 #include <net/9p/transport.h>
  43 #include "protocol.h"
  44
  45 #define CREATE_TRACE_POINTS
  46 #include <trace/events/9p.h>
  47
  48 /*
  49   * Client Option Parsing (code inspired by NFS code)
  50   *  - a little lazy - parse all client options
  51   */
  52
  53 enum {
  54         Opt_msize,
  55         Opt_trans,
  56         Opt_legacy,
  57         Opt_version,
  58         Opt_err,
  59 };
  60
  61 static const match_table_t tokens = {
  62         {Opt_msize, "msize=%u"},
  63         {Opt_legacy, "noextend"},
  64         {Opt_trans, "trans=%s"},
  65         {Opt_version, "version=%s"},
  66         {Opt_err, NULL},
  67 };
  68
  69 inline int p9_is_proto_dotl(struct p9_client *clnt)
  70 {
  71         return clnt->proto_version == p9_proto_2000L;
  72 }
  73 EXPORT_SYMBOL(p9_is_proto_dotl);
  74
  75 inline int p9_is_proto_dotu(struct p9_client *clnt)
  76 {
  77         return clnt->proto_version == p9_proto_2000u;
  78 }
  79 EXPORT_SYMBOL(p9_is_proto_dotu);
  80
  81 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
  82 {
  83         if (clnt->msize != 8192)
  84                 seq_printf(m, ",msize=%u", clnt->msize);
  85         seq_printf(m, "trans=%s", clnt->trans_mod->name);
  86
  87         switch (clnt->proto_version) {
  88         case p9_proto_legacy:
  89                 seq_puts(m, ",noextend");
  90                 break;
  91         case p9_proto_2000u:
  92                 seq_puts(m, ",version=9p2000.u");
  93                 break;
  94         case p9_proto_2000L:
  95                 /* Default */
  96                 break;
  97         }
  98
  99         if (clnt->trans_mod->show_options)
 100                 return clnt->trans_mod->show_options(m, clnt);
 101         return 0;
 102 }
 103 EXPORT_SYMBOL(p9_show_client_options);
 104
 105 /*
 106  * Some error codes are taken directly from the server replies,
 107  * make sure they are valid.
 108  */
 109 static int safe_errno(int err)
 110 {
 111         if ((err > 0) || (err < -MAX_ERRNO)) {
 112                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
 113                 return -EPROTO;
 114         }
 115         return err;
 116 }
 117
 118
 119 /* Interpret mount option for protocol version */
 120 static int get_protocol_version(char *s)
 121 {
 122         int version = -EINVAL;
 123
 124         if (!strcmp(s, "9p2000")) {
 125                 version = p9_proto_legacy;
 126                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
 127         } else if (!strcmp(s, "9p2000.u")) {
 128                 version = p9_proto_2000u;
 129                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
 130         } else if (!strcmp(s, "9p2000.L")) {
 131                 version = p9_proto_2000L;
 132                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
 133         } else
 134                 pr_info("Unknown protocol version %s\n", s);
 135
 136         return version;
 137 }
 138
 139 /**
 140  * parse_options - parse mount options into client structure
 141  * @opts: options string passed from mount
 142  * @clnt: existing v9fs client information
 143  *
 144  * Return 0 upon success, -ERRNO upon failure
 145  */
 146
 147 static int parse_opts(char *opts, struct p9_client *clnt)
 148 {
 149         char *options, *tmp_options;
 150         char *p;
 151         substring_t args[MAX_OPT_ARGS];
 152         int option;
 153         char *s;
 154         int ret = 0;
 155
 156         clnt->proto_version = p9_proto_2000L;
 157         clnt->msize = 8192;
 158
 159         if (!opts)
 160                 return 0;
 161
 162         tmp_options = kstrdup(opts, GFP_KERNEL);
 163         if (!tmp_options) {
 164                 p9_debug(P9_DEBUG_ERROR,
 165                          "failed to allocate copy of option string\n");
 166                 return -ENOMEM;
 167         }
 168         options = tmp_options;
 169
 170         while ((p = strsep(&options, ",")) != NULL) {
 171                 int token, r;
 172                 if (!*p)
 173                         continue;
 174                 token = match_token(p, tokens, args);
 175                 switch (token) {
 176                 case Opt_msize:
 177                         r = match_int(&args[0], &option);
 178                         if (r < 0) {
 179                                 p9_debug(P9_DEBUG_ERROR,
 180                                          "integer field, but no integer?\n");
 181                                 ret = r;
 182                                 continue;
 183                         }
 184                         clnt->msize = option;
 185                         break;
 186                 case Opt_trans:
 187                         s = match_strdup(&args[0]);
 188                         if (!s) {
 189                                 ret = -ENOMEM;
 190                                 p9_debug(P9_DEBUG_ERROR,
 191                                          "problem allocating copy of trans arg\n");
 192                                 goto free_and_return;
 193                          }
 194                         clnt->trans_mod = v9fs_get_trans_by_name(s);
 195                         if (clnt->trans_mod == NULL) {
 196                                 pr_info("Could not find request transport: %s\n",
 197                                         s);
 198                                 ret = -EINVAL;
 199                                 kfree(s);
 200                                 goto free_and_return;
 201                         }
 202                         kfree(s);
 203                         break;
 204                 case Opt_legacy:
 205                         clnt->proto_version = p9_proto_legacy;
 206                         break;
 207                 case Opt_version:
 208                         s = match_strdup(&args[0]);
 209                         if (!s) {
 210                                 ret = -ENOMEM;
 211                                 p9_debug(P9_DEBUG_ERROR,
 212                                          "problem allocating copy of version arg\n");
 213                                 goto free_and_return;
 214                         }
 215                         ret = get_protocol_version(s);
 216                         if (ret == -EINVAL) {
 217                                 kfree(s);
 218                                 goto free_and_return;
 219                         }
 220                         kfree(s);
 221                         clnt->proto_version = ret;
 222                         break;
 223                 default:
 224                         continue;
 225                 }
 226         }
 227
 228 free_and_return:
 229         kfree(tmp_options);
 230         return ret;
 231 }
 232
 233 static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
 234 {
 235         struct p9_fcall *fc;
 236         fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
 237         if (!fc)
 238                 return NULL;
 239         fc->capacity = alloc_msize;
 240         fc->sdata = (char *) fc + sizeof(struct p9_fcall);
 241         return fc;
 242 }
 243
 244 /**
 245  * p9_tag_alloc - lookup/allocate a request by tag
 246  * @c: client session to lookup tag within
 247  * @tag: numeric id for transaction
 248  *
 249  * this is a simple array lookup, but will grow the
 250  * request_slots as necessary to accommodate transaction
 251  * ids which did not previously have a slot.
 252  *
 253  * this code relies on the client spinlock to manage locks, its
 254  * possible we should switch to something else, but I'd rather
 255  * stick with something low-overhead for the common case.
 256  *
 257  */
 258
 259 static struct p9_req_t *
 260 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
 261 {
 262         unsigned long flags;
 263         int row, col;
 264         struct p9_req_t *req;
 265         int alloc_msize = min(c->msize, max_size);
 266
 267         /* This looks up the original request by tag so we know which
 268          * buffer to read the data into */
 269         tag++;
 270
 271         if (tag >= c->max_tag) {
 272                 spin_lock_irqsave(&c->lock, flags);
 273                 /* check again since original check was outside of lock */
 274                 while (tag >= c->max_tag) {
 275                         row = (tag / P9_ROW_MAXTAG);
 276                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 277                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 278
 279                         if (!c->reqs[row]) {
 280                                 pr_err("Couldn't grow tag array\n");
 281                                 spin_unlock_irqrestore(&c->lock, flags);
 282                                 return ERR_PTR(-ENOMEM);
 283                         }
 284                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 285                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 286                                 c->reqs[row][col].tc = NULL;
 287                         }
 288                         c->max_tag += P9_ROW_MAXTAG;
 289                 }
 290                 spin_unlock_irqrestore(&c->lock, flags);
 291         }
 292         row = tag / P9_ROW_MAXTAG;
 293         col = tag % P9_ROW_MAXTAG;
 294
 295         req = &c->reqs[row][col];
 296         if (!req->wq) {
 297                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
 298                 if (!req->wq)
 299                         goto grow_failed;
 300                 init_waitqueue_head(req->wq);
 301         }
 302
 303         if (!req->tc)
 304                 req->tc = p9_fcall_alloc(alloc_msize);
 305         if (!req->rc)
 306                 req->rc = p9_fcall_alloc(alloc_msize);
 307         if (!req->tc || !req->rc)
 308                 goto grow_failed;
 309
 310         p9pdu_reset(req->tc);
 311         p9pdu_reset(req->rc);
 312
 313         req->tc->tag = tag-1;
 314         req->status = REQ_STATUS_ALLOC;
 315
 316         return req;
 317
 318 grow_failed:
 319         pr_err("Couldn't grow tag array\n");
 320         kfree(req->tc);
 321         kfree(req->rc);
 322         kfree(req->wq);
 323         req->tc = req->rc = NULL;
 324         req->wq = NULL;
 325         return ERR_PTR(-ENOMEM);
 326 }
 327
 328 /**
 329  * p9_tag_lookup - lookup a request by tag
 330  * @c: client session to lookup tag within
 331  * @tag: numeric id for transaction
 332  *
 333  */
 334
 335 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 336 {
 337         int row, col;
 338
 339         /* This looks up the original request by tag so we know which
 340          * buffer to read the data into */
 341         tag++;
 342
 343         if(tag >= c->max_tag)
 344                 return NULL;
 345
 346         row = tag / P9_ROW_MAXTAG;
 347         col = tag % P9_ROW_MAXTAG;
 348
 349         return &c->reqs[row][col];
 350 }
 351 EXPORT_SYMBOL(p9_tag_lookup);
 352
 353 /**
 354  * p9_tag_init - setup tags structure and contents
 355  * @c:  v9fs client struct
 356  *
 357  * This initializes the tags structure for each client instance.
 358  *
 359  */
 360
 361 static int p9_tag_init(struct p9_client *c)
 362 {
 363         int err = 0;
 364
 365         c->tagpool = p9_idpool_create();
 366         if (IS_ERR(c->tagpool)) {
 367                 err = PTR_ERR(c->tagpool);
 368                 goto error;
 369         }
 370         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
 371         if (err < 0) {
 372                 p9_idpool_destroy(c->tagpool);
 373                 goto error;
 374         }
 375         c->max_tag = 0;
 376 error:
 377         return err;
 378 }
 379
 380 /**
 381  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 382  * @c:  v9fs client struct
 383  *
 384  * This frees resources associated with the tags structure
 385  *
 386  */
 387 static void p9_tag_cleanup(struct p9_client *c)
 388 {
 389         int row, col;
 390
 391         /* check to insure all requests are idle */
 392         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 393                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 394                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 395                                 p9_debug(P9_DEBUG_MUX,
 396                                          "Attempting to cleanup non-free tag %d,%d\n",
 397                                          row, col);
 398                                 /* TODO: delay execution of cleanup */
 399                                 return;
 400                         }
 401                 }
 402         }
 403
 404         if (c->tagpool) {
 405                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
 406                 p9_idpool_destroy(c->tagpool);
 407         }
 408
 409         /* free requests associated with tags */
 410         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 411                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 412                         kfree(c->reqs[row][col].wq);
 413                         kfree(c->reqs[row][col].tc);
 414                         kfree(c->reqs[row][col].rc);
 415                 }
 416                 kfree(c->reqs[row]);
 417         }
 418         c->max_tag = 0;
 419 }
 420
 421 /**
 422  * p9_free_req - free a request and clean-up as necessary
 423  * c: client state
 424  * r: request to release
 425  *
 426  */
 427
 428 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 429 {
 430         int tag = r->tc->tag;
 431         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 432
 433         r->status = REQ_STATUS_IDLE;
 434         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 435                 p9_idpool_put(tag, c->tagpool);
 436 }
 437
 438 /**
 439  * p9_client_cb - call back from transport to client
 440  * c: client state
 441  * req: request received
 442  *
 443  */
 444 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 445 {
 446         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 447
 448         /*
 449          * This barrier is needed to make sure any change made to req before
 450          * the other thread wakes up will indeed be seen by the waiting side.
 451          */
 452         smp_wmb();
 453         req->status = status;
 454
 455         wake_up(req->wq);
 456         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 457 }
 458 EXPORT_SYMBOL(p9_client_cb);
 459
 460 /**
 461  * p9_parse_header - parse header arguments out of a packet
 462  * @pdu: packet to parse
 463  * @size: size of packet
 464  * @type: type of request
 465  * @tag: tag of packet
 466  * @rewind: set if we need to rewind offset afterwards
 467  */
 468
 469 int
 470 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 471                                                                 int rewind)
 472 {
 473         int8_t r_type;
 474         int16_t r_tag;
 475         int32_t r_size;
 476         int offset = pdu->offset;
 477         int err;
 478
 479         pdu->offset = 0;
 480         if (pdu->size == 0)
 481                 pdu->size = 7;
 482
 483         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 484         if (err)
 485                 goto rewind_and_exit;
 486
 487         pdu->size = r_size;
 488         pdu->id = r_type;
 489         pdu->tag = r_tag;
 490
 491         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 492                  pdu->size, pdu->id, pdu->tag);
 493
 494         if (type)
 495                 *type = r_type;
 496         if (tag)
 497                 *tag = r_tag;
 498         if (size)
 499                 *size = r_size;
 500
 501
 502 rewind_and_exit:
 503         if (rewind)
 504                 pdu->offset = offset;
 505         return err;
 506 }
 507 EXPORT_SYMBOL(p9_parse_header);
 508
 509 /**
 510  * p9_check_errors - check 9p packet for error return and process it
 511  * @c: current client instance
 512  * @req: request to parse and check for error conditions
 513  *
 514  * returns error code if one is discovered, otherwise returns 0
 515  *
 516  * this will have to be more complicated if we have multiple
 517  * error packet types
 518  */
 519
 520 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 521 {
 522         int8_t type;
 523         int err;
 524         int ecode;
 525
 526         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 527         /*
 528          * dump the response from server
 529          * This should be after check errors which poplulate pdu_fcall.
 530          */
 531         trace_9p_protocol_dump(c, req->rc);
 532         if (err) {
 533                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 534                 return err;
 535         }
 536         if (type != P9_RERROR && type != P9_RLERROR)
 537                 return 0;
 538
 539         if (!p9_is_proto_dotl(c)) {
 540                 char *ename;
 541                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 542                                   &ename, &ecode);
 543                 if (err)
 544                         goto out_err;
 545
 546                 if (p9_is_proto_dotu(c) && ecode < 512)
 547                         err = -ecode;
 548
 549                 if (!err) {
 550                         err = p9_errstr2errno(ename, strlen(ename));
 551
 552                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 553                                  -ecode, ename);
 554                 }
 555                 kfree(ename);
 556         } else {
 557                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 558                 err = -ecode;
 559
 560                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 561         }
 562
 563         return err;
 564
 565 out_err:
 566         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 567
 568         return err;
 569 }
 570
 571 /**
 572  * p9_check_zc_errors - check 9p packet for error return and process it
 573  * @c: current client instance
 574  * @req: request to parse and check for error conditions
 575  * @in_hdrlen: Size of response protocol buffer.
 576  *
 577  * returns error code if one is discovered, otherwise returns 0
 578  *
 579  * this will have to be more complicated if we have multiple
 580  * error packet types
 581  */
 582
 583 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 584                               struct iov_iter *uidata, int in_hdrlen)
 585 {
 586         int err;
 587         int ecode;
 588         int8_t type;
 589         char *ename = NULL;
 590
 591         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 592         /*
 593          * dump the response from server
 594          * This should be after parse_header which poplulate pdu_fcall.
 595          */
 596         trace_9p_protocol_dump(c, req->rc);
 597         if (err) {
 598                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 599                 return err;
 600         }
 601
 602         if (type != P9_RERROR && type != P9_RLERROR)
 603                 return 0;
 604
 605         if (!p9_is_proto_dotl(c)) {
 606                 /* Error is reported in string format */
 607                 int len;
 608                 /* 7 = header size for RERROR; */
 609                 int inline_len = in_hdrlen - 7;
 610
 611                 len =  req->rc->size - req->rc->offset;
 612                 if (len > (P9_ZC_HDR_SZ - 7)) {
 613                         err = -EFAULT;
 614                         goto out_err;
 615                 }
 616
 617                 ename = &req->rc->sdata[req->rc->offset];
 618                 if (len > inline_len) {
 619                         /* We have error in external buffer */
 620                         if (!copy_from_iter_full(ename + inline_len,
 621                                              len - inline_len, uidata)) {
 622                                 err = -EFAULT;
 623                                 goto out_err;
 624                         }
 625                 }
 626                 ename = NULL;
 627                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 628                                   &ename, &ecode);
 629                 if (err)
 630                         goto out_err;
 631
 632                 if (p9_is_proto_dotu(c) && ecode < 512)
 633                         err = -ecode;
 634
 635                 if (!err) {
 636                         err = p9_errstr2errno(ename, strlen(ename));
 637
 638                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 639                                  -ecode, ename);
 640                 }
 641                 kfree(ename);
 642         } else {
 643                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 644                 err = -ecode;
 645
 646                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 647         }
 648         return err;
 649
 650 out_err:
 651         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 652         return err;
 653 }
 654
 655 static struct p9_req_t *
 656 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 657
 658 /**
 659  * p9_client_flush - flush (cancel) a request
 660  * @c: client state
 661  * @oldreq: request to cancel
 662  *
 663  * This sents a flush for a particular request and links
 664  * the flush request to the original request.  The current
 665  * code only supports a single flush request although the protocol
 666  * allows for multiple flush requests to be sent for a single request.
 667  *
 668  */
 669
 670 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 671 {
 672         struct p9_req_t *req;
 673         int16_t oldtag;
 674         int err;
 675
 676         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 677         if (err)
 678                 return err;
 679
 680         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 681
 682         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 683         if (IS_ERR(req))
 684                 return PTR_ERR(req);
 685
 686         /*
 687          * if we haven't received a response for oldreq,
 688          * remove it from the list
 689          */
 690         if (oldreq->status == REQ_STATUS_SENT)
 691                 if (c->trans_mod->cancelled)
 692                         c->trans_mod->cancelled(c, oldreq);
 693
 694         p9_free_req(c, req);
 695         return 0;
 696 }
 697
 698 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 699                                               int8_t type, int req_size,
 700                                               const char *fmt, va_list ap)
 701 {
 702         int tag, err;
 703         struct p9_req_t *req;
 704
 705         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 706
 707         /* we allow for any status other than disconnected */
 708         if (c->status == Disconnected)
 709                 return ERR_PTR(-EIO);
 710
 711         /* if status is begin_disconnected we allow only clunk request */
 712         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 713                 return ERR_PTR(-EIO);
 714
 715         tag = P9_NOTAG;
 716         if (type != P9_TVERSION) {
 717                 tag = p9_idpool_get(c->tagpool);
 718                 if (tag < 0)
 719                         return ERR_PTR(-ENOMEM);
 720         }
 721
 722         req = p9_tag_alloc(c, tag, req_size);
 723         if (IS_ERR(req))
 724                 return req;
 725
 726         /* marshall the data */
 727         p9pdu_prepare(req->tc, tag, type);
 728         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 729         if (err)
 730                 goto reterr;
 731         p9pdu_finalize(c, req->tc);
 732         trace_9p_client_req(c, type, tag);
 733         return req;
 734 reterr:
 735         p9_free_req(c, req);
 736         return ERR_PTR(err);
 737 }
 738
 739 /**
 740  * p9_client_rpc - issue a request and wait for a response
 741  * @c: client session
 742  * @type: type of request
 743  * @fmt: protocol format string (see protocol.c)
 744  *
 745  * Returns request structure (which client must free using p9_free_req)
 746  */
 747
 748 static struct p9_req_t *
 749 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 750 {
 751         va_list ap;
 752         int sigpending, err;
 753         unsigned long flags;
 754         struct p9_req_t *req;
 755
 756         va_start(ap, fmt);
 757         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 758         va_end(ap);
 759         if (IS_ERR(req))
 760                 return req;
 761
 762         if (signal_pending(current)) {
 763                 sigpending = 1;
 764                 clear_thread_flag(TIF_SIGPENDING);
 765         } else
 766                 sigpending = 0;
 767
 768         err = c->trans_mod->request(c, req);
 769         if (err < 0) {
 770                 if (err != -ERESTARTSYS && err != -EFAULT)
 771                         c->status = Disconnected;
 772                 goto reterr;
 773         }
 774 again:
 775         /* Wait for the response */
 776         err = wait_event_interruptible(*req->wq,
 777                                        req->status >= REQ_STATUS_RCVD);
 778
 779         /*
 780          * Make sure our req is coherent with regard to updates in other
 781          * threads - echoes to wmb() in the callback
 782          */
 783         smp_rmb();
 784
 785         if ((err == -ERESTARTSYS) && (c->status == Connected)
 786                                   && (type == P9_TFLUSH)) {
 787                 sigpending = 1;
 788                 clear_thread_flag(TIF_SIGPENDING);
 789                 goto again;
 790         }
 791
 792         if (req->status == REQ_STATUS_ERROR) {
 793                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 794                 err = req->t_err;
 795         }
 796         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 797                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 798                 sigpending = 1;
 799                 clear_thread_flag(TIF_SIGPENDING);
 800
 801                 if (c->trans_mod->cancel(c, req))
 802                         p9_client_flush(c, req);
 803
 804                 /* if we received the response anyway, don't signal error */
 805                 if (req->status == REQ_STATUS_RCVD)
 806                         err = 0;
 807         }
 808         if (sigpending) {
 809                 spin_lock_irqsave(&current->sighand->siglock, flags);
 810                 recalc_sigpending();
 811                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 812         }
 813         if (err < 0)
 814                 goto reterr;
 815
 816         err = p9_check_errors(c, req);
 817         trace_9p_client_res(c, type, req->rc->tag, err);
 818         if (!err)
 819                 return req;
 820 reterr:
 821         p9_free_req(c, req);
 822         return ERR_PTR(safe_errno(err));
 823 }
 824
 825 /**
 826  * p9_client_zc_rpc - issue a request and wait for a response
 827  * @c: client session
 828  * @type: type of request
 829  * @uidata: destination for zero copy read
 830  * @uodata: source for zero copy write
 831  * @inlen: read buffer size
 832  * @olen: write buffer size
 833  * @hdrlen: reader header size, This is the size of response protocol data
 834  * @fmt: protocol format string (see protocol.c)
 835  *
 836  * Returns request structure (which client must free using p9_free_req)
 837  */
 838 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 839                                          struct iov_iter *uidata,
 840                                          struct iov_iter *uodata,
 841                                          int inlen, int olen, int in_hdrlen,
 842                                          const char *fmt, ...)
 843 {
 844         va_list ap;
 845         int sigpending, err;
 846         unsigned long flags;
 847         struct p9_req_t *req;
 848
 849         va_start(ap, fmt);
 850         /*
 851          * We allocate a inline protocol data of only 4k bytes.
 852          * The actual content is passed in zero-copy fashion.
 853          */
 854         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 855         va_end(ap);
 856         if (IS_ERR(req))
 857                 return req;
 858
 859         if (signal_pending(current)) {
 860                 sigpending = 1;
 861                 clear_thread_flag(TIF_SIGPENDING);
 862         } else
 863                 sigpending = 0;
 864
 865         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 866                                        inlen, olen, in_hdrlen);
 867         if (err < 0) {
 868                 if (err == -EIO)
 869                         c->status = Disconnected;
 870                 if (err != -ERESTARTSYS)
 871                         goto reterr;
 872         }
 873         if (req->status == REQ_STATUS_ERROR) {
 874                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 875                 err = req->t_err;
 876         }
 877         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 878                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 879                 sigpending = 1;
 880                 clear_thread_flag(TIF_SIGPENDING);
 881
 882                 if (c->trans_mod->cancel(c, req))
 883                         p9_client_flush(c, req);
 884
 885                 /* if we received the response anyway, don't signal error */
 886                 if (req->status == REQ_STATUS_RCVD)
 887                         err = 0;
 888         }
 889         if (sigpending) {
 890                 spin_lock_irqsave(&current->sighand->siglock, flags);
 891                 recalc_sigpending();
 892                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 893         }
 894         if (err < 0)
 895                 goto reterr;
 896
 897         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 898         trace_9p_client_res(c, type, req->rc->tag, err);
 899         if (!err)
 900                 return req;
 901 reterr:
 902         p9_free_req(c, req);
 903         return ERR_PTR(safe_errno(err));
 904 }
 905
 906 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 907 {
 908         int ret;
 909         struct p9_fid *fid;
 910         unsigned long flags;
 911
 912         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 913         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 914         if (!fid)
 915                 return ERR_PTR(-ENOMEM);
 916
 917         ret = p9_idpool_get(clnt->fidpool);
 918         if (ret < 0) {
 919                 ret = -ENOSPC;
 920                 goto error;
 921         }
 922         fid->fid = ret;
 923
 924         memset(&fid->qid, 0, sizeof(struct p9_qid));
 925         fid->mode = -1;
 926         fid->uid = current_fsuid();
 927         fid->clnt = clnt;
 928         fid->rdir = NULL;
 929         spin_lock_irqsave(&clnt->lock, flags);
 930         list_add(&fid->flist, &clnt->fidlist);
 931         spin_unlock_irqrestore(&clnt->lock, flags);
 932
 933         return fid;
 934
 935 error:
 936         kfree(fid);
 937         return ERR_PTR(ret);
 938 }
 939
 940 static void p9_fid_destroy(struct p9_fid *fid)
 941 {
 942         struct p9_client *clnt;
 943         unsigned long flags;
 944
 945         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 946         clnt = fid->clnt;
 947         p9_idpool_put(fid->fid, clnt->fidpool);
 948         spin_lock_irqsave(&clnt->lock, flags);
 949         list_del(&fid->flist);
 950         spin_unlock_irqrestore(&clnt->lock, flags);
 951         kfree(fid->rdir);
 952         kfree(fid);
 953 }
 954
 955 static int p9_client_version(struct p9_client *c)
 956 {
 957         int err = 0;
 958         struct p9_req_t *req;
 959         char *version;
 960         int msize;
 961
 962         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 963                  c->msize, c->proto_version);
 964
 965         switch (c->proto_version) {
 966         case p9_proto_2000L:
 967                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 968                                         c->msize, "9P2000.L");
 969                 break;
 970         case p9_proto_2000u:
 971                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 972                                         c->msize, "9P2000.u");
 973                 break;
 974         case p9_proto_legacy:
 975                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 976                                         c->msize, "9P2000");
 977                 break;
 978         default:
 979                 return -EINVAL;
 980         }
 981
 982         if (IS_ERR(req))
 983                 return PTR_ERR(req);
 984
 985         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 986         if (err) {
 987                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 988                 trace_9p_protocol_dump(c, req->rc);
 989                 goto error;
 990         }
 991
 992         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 993         if (!strncmp(version, "9P2000.L", 8))
 994                 c->proto_version = p9_proto_2000L;
 995         else if (!strncmp(version, "9P2000.u", 8))
 996                 c->proto_version = p9_proto_2000u;
 997         else if (!strncmp(version, "9P2000", 6))
 998                 c->proto_version = p9_proto_legacy;
 999         else {
1000                 err = -EREMOTEIO;
1001                 goto error;
1002         }
1003
1004         if (msize < c->msize)
1005                 c->msize = msize;
1006
1007 error:
1008         kfree(version);
1009         p9_free_req(c, req);
1010
1011         return err;
1012 }
1013
1014 struct p9_client *p9_client_create(const char *dev_name, char *options)
1015 {
1016         int err;
1017         struct p9_client *clnt;
1018         char *client_id;
1019
1020         err = 0;
1021         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1022         if (!clnt)
1023                 return ERR_PTR(-ENOMEM);
1024
1025         clnt->trans_mod = NULL;
1026         clnt->trans = NULL;
1027
1028         client_id = utsname()->nodename;
1029         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1030
1031         spin_lock_init(&clnt->lock);
1032         INIT_LIST_HEAD(&clnt->fidlist);
1033
1034         err = p9_tag_init(clnt);
1035         if (err < 0)
1036                 goto free_client;
1037
1038         err = parse_opts(options, clnt);
1039         if (err < 0)
1040                 goto destroy_tagpool;
1041
1042         if (!clnt->trans_mod)
1043                 clnt->trans_mod = v9fs_get_default_trans();
1044
1045         if (clnt->trans_mod == NULL) {
1046                 err = -EPROTONOSUPPORT;
1047                 p9_debug(P9_DEBUG_ERROR,
1048                          "No transport defined or default transport\n");
1049                 goto destroy_tagpool;
1050         }
1051
1052         clnt->fidpool = p9_idpool_create();
1053         if (IS_ERR(clnt->fidpool)) {
1054                 err = PTR_ERR(clnt->fidpool);
1055                 goto put_trans;
1056         }
1057
1058         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1059                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1060
1061         err = clnt->trans_mod->create(clnt, dev_name, options);
1062         if (err)
1063                 goto destroy_fidpool;
1064
1065         if (clnt->msize > clnt->trans_mod->maxsize)
1066                 clnt->msize = clnt->trans_mod->maxsize;
1067
1068         err = p9_client_version(clnt);
1069         if (err)
1070                 goto close_trans;
1071
1072         return clnt;
1073
1074 close_trans:
1075         clnt->trans_mod->close(clnt);
1076 destroy_fidpool:
1077         p9_idpool_destroy(clnt->fidpool);
1078 put_trans:
1079         v9fs_put_trans(clnt->trans_mod);
1080 destroy_tagpool:
1081         p9_idpool_destroy(clnt->tagpool);
1082 free_client:
1083         kfree(clnt);
1084         return ERR_PTR(err);
1085 }
1086 EXPORT_SYMBOL(p9_client_create);
1087
1088 void p9_client_destroy(struct p9_client *clnt)
1089 {
1090         struct p9_fid *fid, *fidptr;
1091
1092         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1093
1094         if (clnt->trans_mod)
1095                 clnt->trans_mod->close(clnt);
1096
1097         v9fs_put_trans(clnt->trans_mod);
1098
1099         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1100                 pr_info("Found fid %d not clunked\n", fid->fid);
1101                 p9_fid_destroy(fid);
1102         }
1103
1104         if (clnt->fidpool)
1105                 p9_idpool_destroy(clnt->fidpool);
1106
1107         p9_tag_cleanup(clnt);
1108
1109         kfree(clnt);
1110 }
1111 EXPORT_SYMBOL(p9_client_destroy);
1112
1113 void p9_client_disconnect(struct p9_client *clnt)
1114 {
1115         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1116         clnt->status = Disconnected;
1117 }
1118 EXPORT_SYMBOL(p9_client_disconnect);
1119
1120 void p9_client_begin_disconnect(struct p9_client *clnt)
1121 {
1122         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1123         clnt->status = BeginDisconnect;
1124 }
1125 EXPORT_SYMBOL(p9_client_begin_disconnect);
1126
1127 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1128         const char *uname, kuid_t n_uname, const char *aname)
1129 {
1130         int err = 0;
1131         struct p9_req_t *req;
1132         struct p9_fid *fid;
1133         struct p9_qid qid;
1134
1135
1136         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1137                  afid ? afid->fid : -1, uname, aname);
1138         fid = p9_fid_create(clnt);
1139         if (IS_ERR(fid)) {
1140                 err = PTR_ERR(fid);
1141                 fid = NULL;
1142                 goto error;
1143         }
1144         fid->uid = n_uname;
1145
1146         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1147                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1148         if (IS_ERR(req)) {
1149                 err = PTR_ERR(req);
1150                 goto error;
1151         }
1152
1153         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1154         if (err) {
1155                 trace_9p_protocol_dump(clnt, req->rc);
1156                 p9_free_req(clnt, req);
1157                 goto error;
1158         }
1159
1160         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1161                  qid.type, (unsigned long long)qid.path, qid.version);
1162
1163         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1164
1165         p9_free_req(clnt, req);
1166         return fid;
1167
1168 error:
1169         if (fid)
1170                 p9_fid_destroy(fid);
1171         return ERR_PTR(err);
1172 }
1173 EXPORT_SYMBOL(p9_client_attach);
1174
1175 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1176                 const unsigned char * const *wnames, int clone)
1177 {
1178         int err;
1179         struct p9_client *clnt;
1180         struct p9_fid *fid;
1181         struct p9_qid *wqids;
1182         struct p9_req_t *req;
1183         uint16_t nwqids, count;
1184
1185         err = 0;
1186         wqids = NULL;
1187         clnt = oldfid->clnt;
1188         if (clone) {
1189                 fid = p9_fid_create(clnt);
1190                 if (IS_ERR(fid)) {
1191                         err = PTR_ERR(fid);
1192                         fid = NULL;
1193                         goto error;
1194                 }
1195
1196                 fid->uid = oldfid->uid;
1197         } else
1198                 fid = oldfid;
1199
1200
1201         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1202                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1203
1204         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1205                                                                 nwname, wnames);
1206         if (IS_ERR(req)) {
1207                 err = PTR_ERR(req);
1208                 goto error;
1209         }
1210
1211         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1212         if (err) {
1213                 trace_9p_protocol_dump(clnt, req->rc);
1214                 p9_free_req(clnt, req);
1215                 goto clunk_fid;
1216         }
1217         p9_free_req(clnt, req);
1218
1219         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1220
1221         if (nwqids != nwname) {
1222                 err = -ENOENT;
1223                 goto clunk_fid;
1224         }
1225
1226         for (count = 0; count < nwqids; count++)
1227                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1228                         count, wqids[count].type,
1229                         (unsigned long long)wqids[count].path,
1230                         wqids[count].version);
1231
1232         if (nwname)
1233                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1234         else
1235                 fid->qid = oldfid->qid;
1236
1237         kfree(wqids);
1238         return fid;
1239
1240 clunk_fid:
1241         kfree(wqids);
1242         p9_client_clunk(fid);
1243         fid = NULL;
1244
1245 error:
1246         if (fid && (fid != oldfid))
1247                 p9_fid_destroy(fid);
1248
1249         return ERR_PTR(err);
1250 }
1251 EXPORT_SYMBOL(p9_client_walk);
1252
1253 int p9_client_open(struct p9_fid *fid, int mode)
1254 {
1255         int err;
1256         struct p9_client *clnt;
1257         struct p9_req_t *req;
1258         struct p9_qid qid;
1259         int iounit;
1260
1261         clnt = fid->clnt;
1262         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1263                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1264         err = 0;
1265
1266         if (fid->mode != -1)
1267                 return -EINVAL;
1268
1269         if (p9_is_proto_dotl(clnt))
1270                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1271         else
1272                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1273         if (IS_ERR(req)) {
1274                 err = PTR_ERR(req);
1275                 goto error;
1276         }
1277
1278         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1279         if (err) {
1280                 trace_9p_protocol_dump(clnt, req->rc);
1281                 goto free_and_error;
1282         }
1283
1284         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1285                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1286                 (unsigned long long)qid.path, qid.version, iounit);
1287
1288         fid->mode = mode;
1289         fid->iounit = iounit;
1290
1291 free_and_error:
1292         p9_free_req(clnt, req);
1293 error:
1294         return err;
1295 }
1296 EXPORT_SYMBOL(p9_client_open);
1297
1298 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1299                 kgid_t gid, struct p9_qid *qid)
1300 {
1301         int err = 0;
1302         struct p9_client *clnt;
1303         struct p9_req_t *req;
1304         int iounit;
1305
1306         p9_debug(P9_DEBUG_9P,
1307                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1308                         ofid->fid, name, flags, mode,
1309                         from_kgid(&init_user_ns, gid));
1310         clnt = ofid->clnt;
1311
1312         if (ofid->mode != -1)
1313                 return -EINVAL;
1314
1315         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1316                         mode, gid);
1317         if (IS_ERR(req)) {
1318                 err = PTR_ERR(req);
1319                 goto error;
1320         }
1321
1322         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1323         if (err) {
1324                 trace_9p_protocol_dump(clnt, req->rc);
1325                 goto free_and_error;
1326         }
1327
1328         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1329                         qid->type,
1330                         (unsigned long long)qid->path,
1331                         qid->version, iounit);
1332
1333         ofid->mode = mode;
1334         ofid->iounit = iounit;
1335
1336 free_and_error:
1337         p9_free_req(clnt, req);
1338 error:
1339         return err;
1340 }
1341 EXPORT_SYMBOL(p9_client_create_dotl);
1342
1343 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1344                      char *extension)
1345 {
1346         int err;
1347         struct p9_client *clnt;
1348         struct p9_req_t *req;
1349         struct p9_qid qid;
1350         int iounit;
1351
1352         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1353                                                 fid->fid, name, perm, mode);
1354         err = 0;
1355         clnt = fid->clnt;
1356
1357         if (fid->mode != -1)
1358                 return -EINVAL;
1359
1360         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1361                                 mode, extension);
1362         if (IS_ERR(req)) {
1363                 err = PTR_ERR(req);
1364                 goto error;
1365         }
1366
1367         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1368         if (err) {
1369                 trace_9p_protocol_dump(clnt, req->rc);
1370                 goto free_and_error;
1371         }
1372
1373         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1374                                 qid.type,
1375                                 (unsigned long long)qid.path,
1376                                 qid.version, iounit);
1377
1378         fid->mode = mode;
1379         fid->iounit = iounit;
1380
1381 free_and_error:
1382         p9_free_req(clnt, req);
1383 error:
1384         return err;
1385 }
1386 EXPORT_SYMBOL(p9_client_fcreate);
1387
1388 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1389                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1390 {
1391         int err = 0;
1392         struct p9_client *clnt;
1393         struct p9_req_t *req;
1394
1395         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1396                         dfid->fid, name, symtgt);
1397         clnt = dfid->clnt;
1398
1399         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1400                         gid);
1401         if (IS_ERR(req)) {
1402                 err = PTR_ERR(req);
1403                 goto error;
1404         }
1405
1406         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1407         if (err) {
1408                 trace_9p_protocol_dump(clnt, req->rc);
1409                 goto free_and_error;
1410         }
1411
1412         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1413                         qid->type, (unsigned long long)qid->path, qid->version);
1414
1415 free_and_error:
1416         p9_free_req(clnt, req);
1417 error:
1418         return err;
1419 }
1420 EXPORT_SYMBOL(p9_client_symlink);
1421
1422 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1423 {
1424         struct p9_client *clnt;
1425         struct p9_req_t *req;
1426
1427         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1428                         dfid->fid, oldfid->fid, newname);
1429         clnt = dfid->clnt;
1430         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1431                         newname);
1432         if (IS_ERR(req))
1433                 return PTR_ERR(req);
1434
1435         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1436         p9_free_req(clnt, req);
1437         return 0;
1438 }
1439 EXPORT_SYMBOL(p9_client_link);
1440
1441 int p9_client_fsync(struct p9_fid *fid, int datasync)
1442 {
1443         int err;
1444         struct p9_client *clnt;
1445         struct p9_req_t *req;
1446
1447         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1448                         fid->fid, datasync);
1449         err = 0;
1450         clnt = fid->clnt;
1451
1452         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1453         if (IS_ERR(req)) {
1454                 err = PTR_ERR(req);
1455                 goto error;
1456         }
1457
1458         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1459
1460         p9_free_req(clnt, req);
1461
1462 error:
1463         return err;
1464 }
1465 EXPORT_SYMBOL(p9_client_fsync);
1466
1467 int p9_client_clunk(struct p9_fid *fid)
1468 {
1469         int err;
1470         struct p9_client *clnt;
1471         struct p9_req_t *req;
1472         int retries = 0;
1473
1474         if (!fid) {
1475                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1476                         __func__, task_pid_nr(current));
1477                 dump_stack();
1478                 return 0;
1479         }
1480
1481 again:
1482         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1483                                                                 retries);
1484         err = 0;
1485         clnt = fid->clnt;
1486
1487         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1488         if (IS_ERR(req)) {
1489                 err = PTR_ERR(req);
1490                 goto error;
1491         }
1492
1493         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1494
1495         p9_free_req(clnt, req);
1496 error:
1497         /*
1498          * Fid is not valid even after a failed clunk
1499          * If interrupted, retry once then give up and
1500          * leak fid until umount.
1501          */
1502         if (err == -ERESTARTSYS) {
1503                 if (retries++ == 0)
1504                         goto again;
1505         } else
1506                 p9_fid_destroy(fid);
1507         return err;
1508 }
1509 EXPORT_SYMBOL(p9_client_clunk);
1510
1511 int p9_client_remove(struct p9_fid *fid)
1512 {
1513         int err;
1514         struct p9_client *clnt;
1515         struct p9_req_t *req;
1516
1517         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1518         err = 0;
1519         clnt = fid->clnt;
1520
1521         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1522         if (IS_ERR(req)) {
1523                 err = PTR_ERR(req);
1524                 goto error;
1525         }
1526
1527         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1528
1529         p9_free_req(clnt, req);
1530 error:
1531         if (err == -ERESTARTSYS)
1532                 p9_client_clunk(fid);
1533         else
1534                 p9_fid_destroy(fid);
1535         return err;
1536 }
1537 EXPORT_SYMBOL(p9_client_remove);
1538
1539 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1540 {
1541         int err = 0;
1542         struct p9_req_t *req;
1543         struct p9_client *clnt;
1544
1545         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1546                    dfid->fid, name, flags);
1547
1548         clnt = dfid->clnt;
1549         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1550         if (IS_ERR(req)) {
1551                 err = PTR_ERR(req);
1552                 goto error;
1553         }
1554         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1555
1556         p9_free_req(clnt, req);
1557 error:
1558         return err;
1559 }
1560 EXPORT_SYMBOL(p9_client_unlinkat);
1561
1562 int
1563 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1564 {
1565         struct p9_client *clnt = fid->clnt;
1566         struct p9_req_t *req;
1567         int total = 0;
1568         *err = 0;
1569
1570         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1571                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1572
1573         while (iov_iter_count(to)) {
1574                 int count = iov_iter_count(to);
1575                 int rsize, non_zc = 0;
1576                 char *dataptr;
1577
1578                 rsize = fid->iounit;
1579                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1580                         rsize = clnt->msize - P9_IOHDRSZ;
1581
1582                 if (count < rsize)
1583                         rsize = count;
1584
1585                 /* Don't bother zerocopy for small IO (< 1024) */
1586                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1587                         /*
1588                          * response header len is 11
1589                          * PDU Header(7) + IO Size (4)
1590                          */
1591                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1592                                                0, 11, "dqd", fid->fid,
1593                                                offset, rsize);
1594                 } else {
1595                         non_zc = 1;
1596                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1597                                             rsize);
1598                 }
1599                 if (IS_ERR(req)) {
1600                         *err = PTR_ERR(req);
1601                         break;
1602                 }
1603
1604                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1605                                    "D", &count, &dataptr);
1606                 if (*err) {
1607                         trace_9p_protocol_dump(clnt, req->rc);
1608                         p9_free_req(clnt, req);
1609                         break;
1610                 }
1611                 if (rsize < count) {
1612                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1613                         count = rsize;
1614                 }
1615
1616                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1617                 if (!count) {
1618                         p9_free_req(clnt, req);
1619                         break;
1620                 }
1621
1622                 if (non_zc) {
1623                         int n = copy_to_iter(dataptr, count, to);
1624                         total += n;
1625                         offset += n;
1626                         if (n != count) {
1627                                 *err = -EFAULT;
1628                                 p9_free_req(clnt, req);
1629                                 break;
1630                         }
1631                 } else {
1632                         iov_iter_advance(to, count);
1633                         total += count;
1634                         offset += count;
1635                 }
1636                 p9_free_req(clnt, req);
1637         }
1638         return total;
1639 }
1640 EXPORT_SYMBOL(p9_client_read);
1641
1642 int
1643 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1644 {
1645         struct p9_client *clnt = fid->clnt;
1646         struct p9_req_t *req;
1647         int total = 0;
1648         *err = 0;
1649
1650         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1651                                 fid->fid, (unsigned long long) offset,
1652                                 iov_iter_count(from));
1653
1654         while (iov_iter_count(from)) {
1655                 int count = iov_iter_count(from);
1656                 int rsize = fid->iounit;
1657                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1658                         rsize = clnt->msize - P9_IOHDRSZ;
1659
1660                 if (count < rsize)
1661                         rsize = count;
1662
1663                 /* Don't bother zerocopy for small IO (< 1024) */
1664                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1665                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1666                                                rsize, P9_ZC_HDR_SZ, "dqd",
1667                                                fid->fid, offset, rsize);
1668                 } else {
1669                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1670                                                     offset, rsize, from);
1671                 }
1672                 if (IS_ERR(req)) {
1673                         *err = PTR_ERR(req);
1674                         break;
1675                 }
1676
1677                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1678                 if (*err) {
1679                         trace_9p_protocol_dump(clnt, req->rc);
1680                         p9_free_req(clnt, req);
1681                         break;
1682                 }
1683                 if (rsize < count) {
1684                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1685                         count = rsize;
1686                 }
1687
1688                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1689
1690                 p9_free_req(clnt, req);
1691                 iov_iter_advance(from, count);
1692                 total += count;
1693                 offset += count;
1694         }
1695         return total;
1696 }
1697 EXPORT_SYMBOL(p9_client_write);
1698
1699 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1700 {
1701         int err;
1702         struct p9_client *clnt;
1703         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1704         struct p9_req_t *req;
1705         u16 ignored;
1706
1707         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1708
1709         if (!ret)
1710                 return ERR_PTR(-ENOMEM);
1711
1712         err = 0;
1713         clnt = fid->clnt;
1714
1715         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1716         if (IS_ERR(req)) {
1717                 err = PTR_ERR(req);
1718                 goto error;
1719         }
1720
1721         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1722         if (err) {
1723                 trace_9p_protocol_dump(clnt, req->rc);
1724                 p9_free_req(clnt, req);
1725                 goto error;
1726         }
1727
1728         p9_debug(P9_DEBUG_9P,
1729                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1730                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1731                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1732                 "<<<    uid=%d gid=%d n_muid=%d\n",
1733                 ret->size, ret->type, ret->dev, ret->qid.type,
1734                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1735                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1736                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1737                 from_kuid(&init_user_ns, ret->n_uid),
1738                 from_kgid(&init_user_ns, ret->n_gid),
1739                 from_kuid(&init_user_ns, ret->n_muid));
1740
1741         p9_free_req(clnt, req);
1742         return ret;
1743
1744 error:
1745         kfree(ret);
1746         return ERR_PTR(err);
1747 }
1748 EXPORT_SYMBOL(p9_client_stat);
1749
1750 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1751                                                         u64 request_mask)
1752 {
1753         int err;
1754         struct p9_client *clnt;
1755         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1756                                                                 GFP_KERNEL);
1757         struct p9_req_t *req;
1758
1759         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1760                                                         fid->fid, request_mask);
1761
1762         if (!ret)
1763                 return ERR_PTR(-ENOMEM);
1764
1765         err = 0;
1766         clnt = fid->clnt;
1767
1768         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1769         if (IS_ERR(req)) {
1770                 err = PTR_ERR(req);
1771                 goto error;
1772         }
1773
1774         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1775         if (err) {
1776                 trace_9p_protocol_dump(clnt, req->rc);
1777                 p9_free_req(clnt, req);
1778                 goto error;
1779         }
1780
1781         p9_debug(P9_DEBUG_9P,
1782                 "<<< RGETATTR st_result_mask=%lld\n"
1783                 "<<< qid=%x.%llx.%x\n"
1784                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1785                 "<<< st_uid=%d st_gid=%d\n"
1786                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1787                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1788                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1789                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1790                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1791                 "<<< st_gen=%lld st_data_version=%lld",
1792                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1793                 ret->qid.version, ret->st_mode, ret->st_nlink,
1794                 from_kuid(&init_user_ns, ret->st_uid),
1795                 from_kgid(&init_user_ns, ret->st_gid),
1796                 ret->st_rdev, ret->st_size, ret->st_blksize,
1797                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1798                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1799                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1800                 ret->st_gen, ret->st_data_version);
1801
1802         p9_free_req(clnt, req);
1803         return ret;
1804
1805 error:
1806         kfree(ret);
1807         return ERR_PTR(err);
1808 }
1809 EXPORT_SYMBOL(p9_client_getattr_dotl);
1810
1811 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1812 {
1813         int ret;
1814
1815         /* NOTE: size shouldn't include its own length */
1816         /* size[2] type[2] dev[4] qid[13] */
1817         /* mode[4] atime[4] mtime[4] length[8]*/
1818         /* name[s] uid[s] gid[s] muid[s] */
1819         ret = 2+4+13+4+4+4+8+2+2+2+2;
1820
1821         if (wst->name)
1822                 ret += strlen(wst->name);
1823         if (wst->uid)
1824                 ret += strlen(wst->uid);
1825         if (wst->gid)
1826                 ret += strlen(wst->gid);
1827         if (wst->muid)
1828                 ret += strlen(wst->muid);
1829
1830         if ((proto_version == p9_proto_2000u) ||
1831                 (proto_version == p9_proto_2000L)) {
1832                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1833                 if (wst->extension)
1834                         ret += strlen(wst->extension);
1835         }
1836
1837         return ret;
1838 }
1839
1840 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1841 {
1842         int err;
1843         struct p9_req_t *req;
1844         struct p9_client *clnt;
1845
1846         err = 0;
1847         clnt = fid->clnt;
1848         wst->size = p9_client_statsize(wst, clnt->proto_version);
1849         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1850         p9_debug(P9_DEBUG_9P,
1851                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1852                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1853                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1854                 "     uid=%d gid=%d n_muid=%d\n",
1855                 wst->size, wst->type, wst->dev, wst->qid.type,
1856                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1857                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1858                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1859                 from_kuid(&init_user_ns, wst->n_uid),
1860                 from_kgid(&init_user_ns, wst->n_gid),
1861                 from_kuid(&init_user_ns, wst->n_muid));
1862
1863         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1864         if (IS_ERR(req)) {
1865                 err = PTR_ERR(req);
1866                 goto error;
1867         }
1868
1869         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1870
1871         p9_free_req(clnt, req);
1872 error:
1873         return err;
1874 }
1875 EXPORT_SYMBOL(p9_client_wstat);
1876
1877 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1878 {
1879         int err;
1880         struct p9_req_t *req;
1881         struct p9_client *clnt;
1882
1883         err = 0;
1884         clnt = fid->clnt;
1885         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1886         p9_debug(P9_DEBUG_9P,
1887                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1888                 "    atime_sec=%lld atime_nsec=%lld\n"
1889                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1890                 p9attr->valid, p9attr->mode,
1891                 from_kuid(&init_user_ns, p9attr->uid),
1892                 from_kgid(&init_user_ns, p9attr->gid),
1893                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1894                 p9attr->mtime_sec, p9attr->mtime_nsec);
1895
1896         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1897
1898         if (IS_ERR(req)) {
1899                 err = PTR_ERR(req);
1900                 goto error;
1901         }
1902         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1903         p9_free_req(clnt, req);
1904 error:
1905         return err;
1906 }
1907 EXPORT_SYMBOL(p9_client_setattr);
1908
1909 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1910 {
1911         int err;
1912         struct p9_req_t *req;
1913         struct p9_client *clnt;
1914
1915         err = 0;
1916         clnt = fid->clnt;
1917
1918         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1919
1920         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1921         if (IS_ERR(req)) {
1922                 err = PTR_ERR(req);
1923                 goto error;
1924         }
1925
1926         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1927                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1928                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1929         if (err) {
1930                 trace_9p_protocol_dump(clnt, req->rc);
1931                 p9_free_req(clnt, req);
1932                 goto error;
1933         }
1934
1935         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1936                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1937                 "fsid %llu namelen %ld\n",
1938                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1939                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1940                 sb->fsid, (long int)sb->namelen);
1941
1942         p9_free_req(clnt, req);
1943 error:
1944         return err;
1945 }
1946 EXPORT_SYMBOL(p9_client_statfs);
1947
1948 int p9_client_rename(struct p9_fid *fid,
1949                      struct p9_fid *newdirfid, const char *name)
1950 {
1951         int err;
1952         struct p9_req_t *req;
1953         struct p9_client *clnt;
1954
1955         err = 0;
1956         clnt = fid->clnt;
1957
1958         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1959                         fid->fid, newdirfid->fid, name);
1960
1961         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1962                         newdirfid->fid, name);
1963         if (IS_ERR(req)) {
1964                 err = PTR_ERR(req);
1965                 goto error;
1966         }
1967
1968         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1969
1970         p9_free_req(clnt, req);
1971 error:
1972         return err;
1973 }
1974 EXPORT_SYMBOL(p9_client_rename);
1975
1976 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1977                        struct p9_fid *newdirfid, const char *new_name)
1978 {
1979         int err;
1980         struct p9_req_t *req;
1981         struct p9_client *clnt;
1982
1983         err = 0;
1984         clnt = olddirfid->clnt;
1985
1986         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1987                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1988                    newdirfid->fid, new_name);
1989
1990         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1991                             old_name, newdirfid->fid, new_name);
1992         if (IS_ERR(req)) {
1993                 err = PTR_ERR(req);
1994                 goto error;
1995         }
1996
1997         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1998                    newdirfid->fid, new_name);
1999
2000         p9_free_req(clnt, req);
2001 error:
2002         return err;
2003 }
2004 EXPORT_SYMBOL(p9_client_renameat);
2005
2006 /*
2007  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2008  */
2009 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2010                                 const char *attr_name, u64 *attr_size)
2011 {
2012         int err;
2013         struct p9_req_t *req;
2014         struct p9_client *clnt;
2015         struct p9_fid *attr_fid;
2016
2017         err = 0;
2018         clnt = file_fid->clnt;
2019         attr_fid = p9_fid_create(clnt);
2020         if (IS_ERR(attr_fid)) {
2021                 err = PTR_ERR(attr_fid);
2022                 attr_fid = NULL;
2023                 goto error;
2024         }
2025         p9_debug(P9_DEBUG_9P,
2026                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2027                 file_fid->fid, attr_fid->fid, attr_name);
2028
2029         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2030                         file_fid->fid, attr_fid->fid, attr_name);
2031         if (IS_ERR(req)) {
2032                 err = PTR_ERR(req);
2033                 goto error;
2034         }
2035         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2036         if (err) {
2037                 trace_9p_protocol_dump(clnt, req->rc);
2038                 p9_free_req(clnt, req);
2039                 goto clunk_fid;
2040         }
2041         p9_free_req(clnt, req);
2042         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2043                 attr_fid->fid, *attr_size);
2044         return attr_fid;
2045 clunk_fid:
2046         p9_client_clunk(attr_fid);
2047         attr_fid = NULL;
2048 error:
2049         if (attr_fid && (attr_fid != file_fid))
2050                 p9_fid_destroy(attr_fid);
2051
2052         return ERR_PTR(err);
2053 }
2054 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2055
2056 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2057                         u64 attr_size, int flags)
2058 {
2059         int err;
2060         struct p9_req_t *req;
2061         struct p9_client *clnt;
2062
2063         p9_debug(P9_DEBUG_9P,
2064                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2065                 fid->fid, name, (long long)attr_size, flags);
2066         err = 0;
2067         clnt = fid->clnt;
2068         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2069                         fid->fid, name, attr_size, flags);
2070         if (IS_ERR(req)) {
2071                 err = PTR_ERR(req);
2072                 goto error;
2073         }
2074         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2075         p9_free_req(clnt, req);
2076 error:
2077         return err;
2078 }
2079 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2080
2081 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2082 {
2083         int err, rsize, non_zc = 0;
2084         struct p9_client *clnt;
2085         struct p9_req_t *req;
2086         char *dataptr;
2087         struct kvec kv = {.iov_base = data, .iov_len = count};
2088         struct iov_iter to;
2089
2090         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2091
2092         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2093                                 fid->fid, (unsigned long long) offset, count);
2094
2095         err = 0;
2096         clnt = fid->clnt;
2097
2098         rsize = fid->iounit;
2099         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2100                 rsize = clnt->msize - P9_READDIRHDRSZ;
2101
2102         if (count < rsize)
2103                 rsize = count;
2104
2105         /* Don't bother zerocopy for small IO (< 1024) */
2106         if (clnt->trans_mod->zc_request && rsize > 1024) {
2107                 /*
2108                  * response header len is 11
2109                  * PDU Header(7) + IO Size (4)
2110                  */
2111                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2112                                        11, "dqd", fid->fid, offset, rsize);
2113         } else {
2114                 non_zc = 1;
2115                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2116                                     offset, rsize);
2117         }
2118         if (IS_ERR(req)) {
2119                 err = PTR_ERR(req);
2120                 goto error;
2121         }
2122
2123         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2124         if (err) {
2125                 trace_9p_protocol_dump(clnt, req->rc);
2126                 goto free_and_error;
2127         }
2128         if (rsize < count) {
2129                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2130                 count = rsize;
2131         }
2132
2133         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2134
2135         if (non_zc)
2136                 memmove(data, dataptr, count);
2137
2138         p9_free_req(clnt, req);
2139         return count;
2140
2141 free_and_error:
2142         p9_free_req(clnt, req);
2143 error:
2144         return err;
2145 }
2146 EXPORT_SYMBOL(p9_client_readdir);
2147
2148 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2149                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2150 {
2151         int err;
2152         struct p9_client *clnt;
2153         struct p9_req_t *req;
2154
2155         err = 0;
2156         clnt = fid->clnt;
2157         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2158                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2159         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2160                 MAJOR(rdev), MINOR(rdev), gid);
2161         if (IS_ERR(req))
2162                 return PTR_ERR(req);
2163
2164         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2165         if (err) {
2166                 trace_9p_protocol_dump(clnt, req->rc);
2167                 goto error;
2168         }
2169         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2170                                 (unsigned long long)qid->path, qid->version);
2171
2172 error:
2173         p9_free_req(clnt, req);
2174         return err;
2175
2176 }
2177 EXPORT_SYMBOL(p9_client_mknod_dotl);
2178
2179 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2180                                 kgid_t gid, struct p9_qid *qid)
2181 {
2182         int err;
2183         struct p9_client *clnt;
2184         struct p9_req_t *req;
2185
2186         err = 0;
2187         clnt = fid->clnt;
2188         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2189                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2190         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2191                 gid);
2192         if (IS_ERR(req))
2193                 return PTR_ERR(req);
2194
2195         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2196         if (err) {
2197                 trace_9p_protocol_dump(clnt, req->rc);
2198                 goto error;
2199         }
2200         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2201                                 (unsigned long long)qid->path, qid->version);
2202
2203 error:
2204         p9_free_req(clnt, req);
2205         return err;
2206
2207 }
2208 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2209
2210 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2211 {
2212         int err;
2213         struct p9_client *clnt;
2214         struct p9_req_t *req;
2215
2216         err = 0;
2217         clnt = fid->clnt;
2218         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2219                         "start %lld length %lld proc_id %d client_id %s\n",
2220                         fid->fid, flock->type, flock->flags, flock->start,
2221                         flock->length, flock->proc_id, flock->client_id);
2222
2223         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2224                                 flock->flags, flock->start, flock->length,
2225                                         flock->proc_id, flock->client_id);
2226
2227         if (IS_ERR(req))
2228                 return PTR_ERR(req);
2229
2230         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2231         if (err) {
2232                 trace_9p_protocol_dump(clnt, req->rc);
2233                 goto error;
2234         }
2235         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2236 error:
2237         p9_free_req(clnt, req);
2238         return err;
2239
2240 }
2241 EXPORT_SYMBOL(p9_client_lock_dotl);
2242
2243 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2244 {
2245         int err;
2246         struct p9_client *clnt;
2247         struct p9_req_t *req;
2248
2249         err = 0;
2250         clnt = fid->clnt;
2251         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2252                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2253                 glock->start, glock->length, glock->proc_id, glock->client_id);
2254
2255         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2256                 glock->start, glock->length, glock->proc_id, glock->client_id);
2257
2258         if (IS_ERR(req))
2259                 return PTR_ERR(req);
2260
2261         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2262                         &glock->start, &glock->length, &glock->proc_id,
2263                         &glock->client_id);
2264         if (err) {
2265                 trace_9p_protocol_dump(clnt, req->rc);
2266                 goto error;
2267         }
2268         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2269                 "proc_id %d client_id %s\n", glock->type, glock->start,
2270                 glock->length, glock->proc_id, glock->client_id);
2271 error:
2272         p9_free_req(clnt, req);
2273         return err;
2274 }
2275 EXPORT_SYMBOL(p9_client_getlock_dotl);
2276
2277 int p9_client_readlink(struct p9_fid *fid, char **target)
2278 {
2279         int err;
2280         struct p9_client *clnt;
2281         struct p9_req_t *req;
2282
2283         err = 0;
2284         clnt = fid->clnt;
2285         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2286
2287         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2288         if (IS_ERR(req))
2289                 return PTR_ERR(req);
2290
2291         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2292         if (err) {
2293                 trace_9p_protocol_dump(clnt, req->rc);
2294                 goto error;
2295         }
2296         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2297 error:
2298         p9_free_req(clnt, req);
2299         return err;
2300 }
2301 EXPORT_SYMBOL(p9_client_readlink);