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/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_killable(*req->wq, req->status >= REQ_STATUS_RCVD);
 777
 778         /*
 779          * Make sure our req is coherent with regard to updates in other
 780          * threads - echoes to wmb() in the callback
 781          */
 782         smp_rmb();
 783
 784         if ((err == -ERESTARTSYS) && (c->status == Connected)
 785                                   && (type == P9_TFLUSH)) {
 786                 sigpending = 1;
 787                 clear_thread_flag(TIF_SIGPENDING);
 788                 goto again;
 789         }
 790
 791         if (req->status == REQ_STATUS_ERROR) {
 792                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 793                 err = req->t_err;
 794         }
 795         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 796                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 797                 sigpending = 1;
 798                 clear_thread_flag(TIF_SIGPENDING);
 799
 800                 if (c->trans_mod->cancel(c, req))
 801                         p9_client_flush(c, req);
 802
 803                 /* if we received the response anyway, don't signal error */
 804                 if (req->status == REQ_STATUS_RCVD)
 805                         err = 0;
 806         }
 807         if (sigpending) {
 808                 spin_lock_irqsave(&current->sighand->siglock, flags);
 809                 recalc_sigpending();
 810                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 811         }
 812         if (err < 0)
 813                 goto reterr;
 814
 815         err = p9_check_errors(c, req);
 816         trace_9p_client_res(c, type, req->rc->tag, err);
 817         if (!err)
 818                 return req;
 819 reterr:
 820         p9_free_req(c, req);
 821         return ERR_PTR(safe_errno(err));
 822 }
 823
 824 /**
 825  * p9_client_zc_rpc - issue a request and wait for a response
 826  * @c: client session
 827  * @type: type of request
 828  * @uidata: destination for zero copy read
 829  * @uodata: source for zero copy write
 830  * @inlen: read buffer size
 831  * @olen: write buffer size
 832  * @hdrlen: reader header size, This is the size of response protocol data
 833  * @fmt: protocol format string (see protocol.c)
 834  *
 835  * Returns request structure (which client must free using p9_free_req)
 836  */
 837 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 838                                          struct iov_iter *uidata,
 839                                          struct iov_iter *uodata,
 840                                          int inlen, int olen, int in_hdrlen,
 841                                          const char *fmt, ...)
 842 {
 843         va_list ap;
 844         int sigpending, err;
 845         unsigned long flags;
 846         struct p9_req_t *req;
 847
 848         va_start(ap, fmt);
 849         /*
 850          * We allocate a inline protocol data of only 4k bytes.
 851          * The actual content is passed in zero-copy fashion.
 852          */
 853         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 854         va_end(ap);
 855         if (IS_ERR(req))
 856                 return req;
 857
 858         if (signal_pending(current)) {
 859                 sigpending = 1;
 860                 clear_thread_flag(TIF_SIGPENDING);
 861         } else
 862                 sigpending = 0;
 863
 864         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 865                                        inlen, olen, in_hdrlen);
 866         if (err < 0) {
 867                 if (err == -EIO)
 868                         c->status = Disconnected;
 869                 if (err != -ERESTARTSYS)
 870                         goto reterr;
 871         }
 872         if (req->status == REQ_STATUS_ERROR) {
 873                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 874                 err = req->t_err;
 875         }
 876         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 877                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 878                 sigpending = 1;
 879                 clear_thread_flag(TIF_SIGPENDING);
 880
 881                 if (c->trans_mod->cancel(c, req))
 882                         p9_client_flush(c, req);
 883
 884                 /* if we received the response anyway, don't signal error */
 885                 if (req->status == REQ_STATUS_RCVD)
 886                         err = 0;
 887         }
 888         if (sigpending) {
 889                 spin_lock_irqsave(&current->sighand->siglock, flags);
 890                 recalc_sigpending();
 891                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 892         }
 893         if (err < 0)
 894                 goto reterr;
 895
 896         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 897         trace_9p_client_res(c, type, req->rc->tag, err);
 898         if (!err)
 899                 return req;
 900 reterr:
 901         p9_free_req(c, req);
 902         return ERR_PTR(safe_errno(err));
 903 }
 904
 905 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 906 {
 907         int ret;
 908         struct p9_fid *fid;
 909         unsigned long flags;
 910
 911         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 912         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 913         if (!fid)
 914                 return ERR_PTR(-ENOMEM);
 915
 916         ret = p9_idpool_get(clnt->fidpool);
 917         if (ret < 0) {
 918                 ret = -ENOSPC;
 919                 goto error;
 920         }
 921         fid->fid = ret;
 922
 923         memset(&fid->qid, 0, sizeof(struct p9_qid));
 924         fid->mode = -1;
 925         fid->uid = current_fsuid();
 926         fid->clnt = clnt;
 927         fid->rdir = NULL;
 928         spin_lock_irqsave(&clnt->lock, flags);
 929         list_add(&fid->flist, &clnt->fidlist);
 930         spin_unlock_irqrestore(&clnt->lock, flags);
 931
 932         return fid;
 933
 934 error:
 935         kfree(fid);
 936         return ERR_PTR(ret);
 937 }
 938
 939 static void p9_fid_destroy(struct p9_fid *fid)
 940 {
 941         struct p9_client *clnt;
 942         unsigned long flags;
 943
 944         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 945         clnt = fid->clnt;
 946         p9_idpool_put(fid->fid, clnt->fidpool);
 947         spin_lock_irqsave(&clnt->lock, flags);
 948         list_del(&fid->flist);
 949         spin_unlock_irqrestore(&clnt->lock, flags);
 950         kfree(fid->rdir);
 951         kfree(fid);
 952 }
 953
 954 static int p9_client_version(struct p9_client *c)
 955 {
 956         int err = 0;
 957         struct p9_req_t *req;
 958         char *version;
 959         int msize;
 960
 961         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 962                  c->msize, c->proto_version);
 963
 964         switch (c->proto_version) {
 965         case p9_proto_2000L:
 966                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 967                                         c->msize, "9P2000.L");
 968                 break;
 969         case p9_proto_2000u:
 970                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 971                                         c->msize, "9P2000.u");
 972                 break;
 973         case p9_proto_legacy:
 974                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 975                                         c->msize, "9P2000");
 976                 break;
 977         default:
 978                 return -EINVAL;
 979         }
 980
 981         if (IS_ERR(req))
 982                 return PTR_ERR(req);
 983
 984         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 985         if (err) {
 986                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 987                 trace_9p_protocol_dump(c, req->rc);
 988                 goto error;
 989         }
 990
 991         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 992         if (!strncmp(version, "9P2000.L", 8))
 993                 c->proto_version = p9_proto_2000L;
 994         else if (!strncmp(version, "9P2000.u", 8))
 995                 c->proto_version = p9_proto_2000u;
 996         else if (!strncmp(version, "9P2000", 6))
 997                 c->proto_version = p9_proto_legacy;
 998         else {
 999                 err = -EREMOTEIO;
1000                 goto error;
1001         }
1002
1003         if (msize < c->msize)
1004                 c->msize = msize;
1005
1006 error:
1007         kfree(version);
1008         p9_free_req(c, req);
1009
1010         return err;
1011 }
1012
1013 struct p9_client *p9_client_create(const char *dev_name, char *options)
1014 {
1015         int err;
1016         struct p9_client *clnt;
1017         char *client_id;
1018
1019         err = 0;
1020         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1021         if (!clnt)
1022                 return ERR_PTR(-ENOMEM);
1023
1024         clnt->trans_mod = NULL;
1025         clnt->trans = NULL;
1026
1027         client_id = utsname()->nodename;
1028         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1029
1030         spin_lock_init(&clnt->lock);
1031         INIT_LIST_HEAD(&clnt->fidlist);
1032
1033         err = p9_tag_init(clnt);
1034         if (err < 0)
1035                 goto free_client;
1036
1037         err = parse_opts(options, clnt);
1038         if (err < 0)
1039                 goto destroy_tagpool;
1040
1041         if (!clnt->trans_mod)
1042                 clnt->trans_mod = v9fs_get_default_trans();
1043
1044         if (clnt->trans_mod == NULL) {
1045                 err = -EPROTONOSUPPORT;
1046                 p9_debug(P9_DEBUG_ERROR,
1047                          "No transport defined or default transport\n");
1048                 goto destroy_tagpool;
1049         }
1050
1051         clnt->fidpool = p9_idpool_create();
1052         if (IS_ERR(clnt->fidpool)) {
1053                 err = PTR_ERR(clnt->fidpool);
1054                 goto put_trans;
1055         }
1056
1057         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1058                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1059
1060         err = clnt->trans_mod->create(clnt, dev_name, options);
1061         if (err)
1062                 goto destroy_fidpool;
1063
1064         if (clnt->msize > clnt->trans_mod->maxsize)
1065                 clnt->msize = clnt->trans_mod->maxsize;
1066
1067         err = p9_client_version(clnt);
1068         if (err)
1069                 goto close_trans;
1070
1071         return clnt;
1072
1073 close_trans:
1074         clnt->trans_mod->close(clnt);
1075 destroy_fidpool:
1076         p9_idpool_destroy(clnt->fidpool);
1077 put_trans:
1078         v9fs_put_trans(clnt->trans_mod);
1079 destroy_tagpool:
1080         p9_idpool_destroy(clnt->tagpool);
1081 free_client:
1082         kfree(clnt);
1083         return ERR_PTR(err);
1084 }
1085 EXPORT_SYMBOL(p9_client_create);
1086
1087 void p9_client_destroy(struct p9_client *clnt)
1088 {
1089         struct p9_fid *fid, *fidptr;
1090
1091         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1092
1093         if (clnt->trans_mod)
1094                 clnt->trans_mod->close(clnt);
1095
1096         v9fs_put_trans(clnt->trans_mod);
1097
1098         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1099                 pr_info("Found fid %d not clunked\n", fid->fid);
1100                 p9_fid_destroy(fid);
1101         }
1102
1103         if (clnt->fidpool)
1104                 p9_idpool_destroy(clnt->fidpool);
1105
1106         p9_tag_cleanup(clnt);
1107
1108         kfree(clnt);
1109 }
1110 EXPORT_SYMBOL(p9_client_destroy);
1111
1112 void p9_client_disconnect(struct p9_client *clnt)
1113 {
1114         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1115         clnt->status = Disconnected;
1116 }
1117 EXPORT_SYMBOL(p9_client_disconnect);
1118
1119 void p9_client_begin_disconnect(struct p9_client *clnt)
1120 {
1121         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1122         clnt->status = BeginDisconnect;
1123 }
1124 EXPORT_SYMBOL(p9_client_begin_disconnect);
1125
1126 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1127         const char *uname, kuid_t n_uname, const char *aname)
1128 {
1129         int err = 0;
1130         struct p9_req_t *req;
1131         struct p9_fid *fid;
1132         struct p9_qid qid;
1133
1134
1135         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1136                  afid ? afid->fid : -1, uname, aname);
1137         fid = p9_fid_create(clnt);
1138         if (IS_ERR(fid)) {
1139                 err = PTR_ERR(fid);
1140                 fid = NULL;
1141                 goto error;
1142         }
1143         fid->uid = n_uname;
1144
1145         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1146                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1147         if (IS_ERR(req)) {
1148                 err = PTR_ERR(req);
1149                 goto error;
1150         }
1151
1152         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1153         if (err) {
1154                 trace_9p_protocol_dump(clnt, req->rc);
1155                 p9_free_req(clnt, req);
1156                 goto error;
1157         }
1158
1159         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1160                  qid.type, (unsigned long long)qid.path, qid.version);
1161
1162         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1163
1164         p9_free_req(clnt, req);
1165         return fid;
1166
1167 error:
1168         if (fid)
1169                 p9_fid_destroy(fid);
1170         return ERR_PTR(err);
1171 }
1172 EXPORT_SYMBOL(p9_client_attach);
1173
1174 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1175                 const unsigned char * const *wnames, int clone)
1176 {
1177         int err;
1178         struct p9_client *clnt;
1179         struct p9_fid *fid;
1180         struct p9_qid *wqids;
1181         struct p9_req_t *req;
1182         uint16_t nwqids, count;
1183
1184         err = 0;
1185         wqids = NULL;
1186         clnt = oldfid->clnt;
1187         if (clone) {
1188                 fid = p9_fid_create(clnt);
1189                 if (IS_ERR(fid)) {
1190                         err = PTR_ERR(fid);
1191                         fid = NULL;
1192                         goto error;
1193                 }
1194
1195                 fid->uid = oldfid->uid;
1196         } else
1197                 fid = oldfid;
1198
1199
1200         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1201                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1202
1203         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1204                                                                 nwname, wnames);
1205         if (IS_ERR(req)) {
1206                 err = PTR_ERR(req);
1207                 goto error;
1208         }
1209
1210         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1211         if (err) {
1212                 trace_9p_protocol_dump(clnt, req->rc);
1213                 p9_free_req(clnt, req);
1214                 goto clunk_fid;
1215         }
1216         p9_free_req(clnt, req);
1217
1218         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1219
1220         if (nwqids != nwname) {
1221                 err = -ENOENT;
1222                 goto clunk_fid;
1223         }
1224
1225         for (count = 0; count < nwqids; count++)
1226                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1227                         count, wqids[count].type,
1228                         (unsigned long long)wqids[count].path,
1229                         wqids[count].version);
1230
1231         if (nwname)
1232                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1233         else
1234                 fid->qid = oldfid->qid;
1235
1236         kfree(wqids);
1237         return fid;
1238
1239 clunk_fid:
1240         kfree(wqids);
1241         p9_client_clunk(fid);
1242         fid = NULL;
1243
1244 error:
1245         if (fid && (fid != oldfid))
1246                 p9_fid_destroy(fid);
1247
1248         return ERR_PTR(err);
1249 }
1250 EXPORT_SYMBOL(p9_client_walk);
1251
1252 int p9_client_open(struct p9_fid *fid, int mode)
1253 {
1254         int err;
1255         struct p9_client *clnt;
1256         struct p9_req_t *req;
1257         struct p9_qid qid;
1258         int iounit;
1259
1260         clnt = fid->clnt;
1261         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1262                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1263         err = 0;
1264
1265         if (fid->mode != -1)
1266                 return -EINVAL;
1267
1268         if (p9_is_proto_dotl(clnt))
1269                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1270         else
1271                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1272         if (IS_ERR(req)) {
1273                 err = PTR_ERR(req);
1274                 goto error;
1275         }
1276
1277         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1278         if (err) {
1279                 trace_9p_protocol_dump(clnt, req->rc);
1280                 goto free_and_error;
1281         }
1282
1283         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1284                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1285                 (unsigned long long)qid.path, qid.version, iounit);
1286
1287         fid->mode = mode;
1288         fid->iounit = iounit;
1289
1290 free_and_error:
1291         p9_free_req(clnt, req);
1292 error:
1293         return err;
1294 }
1295 EXPORT_SYMBOL(p9_client_open);
1296
1297 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1298                 kgid_t gid, struct p9_qid *qid)
1299 {
1300         int err = 0;
1301         struct p9_client *clnt;
1302         struct p9_req_t *req;
1303         int iounit;
1304
1305         p9_debug(P9_DEBUG_9P,
1306                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1307                         ofid->fid, name, flags, mode,
1308                         from_kgid(&init_user_ns, gid));
1309         clnt = ofid->clnt;
1310
1311         if (ofid->mode != -1)
1312                 return -EINVAL;
1313
1314         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1315                         mode, gid);
1316         if (IS_ERR(req)) {
1317                 err = PTR_ERR(req);
1318                 goto error;
1319         }
1320
1321         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1322         if (err) {
1323                 trace_9p_protocol_dump(clnt, req->rc);
1324                 goto free_and_error;
1325         }
1326
1327         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1328                         qid->type,
1329                         (unsigned long long)qid->path,
1330                         qid->version, iounit);
1331
1332         ofid->mode = mode;
1333         ofid->iounit = iounit;
1334
1335 free_and_error:
1336         p9_free_req(clnt, req);
1337 error:
1338         return err;
1339 }
1340 EXPORT_SYMBOL(p9_client_create_dotl);
1341
1342 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1343                      char *extension)
1344 {
1345         int err;
1346         struct p9_client *clnt;
1347         struct p9_req_t *req;
1348         struct p9_qid qid;
1349         int iounit;
1350
1351         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1352                                                 fid->fid, name, perm, mode);
1353         err = 0;
1354         clnt = fid->clnt;
1355
1356         if (fid->mode != -1)
1357                 return -EINVAL;
1358
1359         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1360                                 mode, extension);
1361         if (IS_ERR(req)) {
1362                 err = PTR_ERR(req);
1363                 goto error;
1364         }
1365
1366         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1367         if (err) {
1368                 trace_9p_protocol_dump(clnt, req->rc);
1369                 goto free_and_error;
1370         }
1371
1372         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1373                                 qid.type,
1374                                 (unsigned long long)qid.path,
1375                                 qid.version, iounit);
1376
1377         fid->mode = mode;
1378         fid->iounit = iounit;
1379
1380 free_and_error:
1381         p9_free_req(clnt, req);
1382 error:
1383         return err;
1384 }
1385 EXPORT_SYMBOL(p9_client_fcreate);
1386
1387 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1388                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1389 {
1390         int err = 0;
1391         struct p9_client *clnt;
1392         struct p9_req_t *req;
1393
1394         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1395                         dfid->fid, name, symtgt);
1396         clnt = dfid->clnt;
1397
1398         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1399                         gid);
1400         if (IS_ERR(req)) {
1401                 err = PTR_ERR(req);
1402                 goto error;
1403         }
1404
1405         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1406         if (err) {
1407                 trace_9p_protocol_dump(clnt, req->rc);
1408                 goto free_and_error;
1409         }
1410
1411         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1412                         qid->type, (unsigned long long)qid->path, qid->version);
1413
1414 free_and_error:
1415         p9_free_req(clnt, req);
1416 error:
1417         return err;
1418 }
1419 EXPORT_SYMBOL(p9_client_symlink);
1420
1421 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1422 {
1423         struct p9_client *clnt;
1424         struct p9_req_t *req;
1425
1426         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1427                         dfid->fid, oldfid->fid, newname);
1428         clnt = dfid->clnt;
1429         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1430                         newname);
1431         if (IS_ERR(req))
1432                 return PTR_ERR(req);
1433
1434         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1435         p9_free_req(clnt, req);
1436         return 0;
1437 }
1438 EXPORT_SYMBOL(p9_client_link);
1439
1440 int p9_client_fsync(struct p9_fid *fid, int datasync)
1441 {
1442         int err;
1443         struct p9_client *clnt;
1444         struct p9_req_t *req;
1445
1446         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1447                         fid->fid, datasync);
1448         err = 0;
1449         clnt = fid->clnt;
1450
1451         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1452         if (IS_ERR(req)) {
1453                 err = PTR_ERR(req);
1454                 goto error;
1455         }
1456
1457         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1458
1459         p9_free_req(clnt, req);
1460
1461 error:
1462         return err;
1463 }
1464 EXPORT_SYMBOL(p9_client_fsync);
1465
1466 int p9_client_clunk(struct p9_fid *fid)
1467 {
1468         int err;
1469         struct p9_client *clnt;
1470         struct p9_req_t *req;
1471         int retries = 0;
1472
1473         if (!fid) {
1474                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1475                         __func__, task_pid_nr(current));
1476                 dump_stack();
1477                 return 0;
1478         }
1479
1480 again:
1481         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1482                                                                 retries);
1483         err = 0;
1484         clnt = fid->clnt;
1485
1486         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1487         if (IS_ERR(req)) {
1488                 err = PTR_ERR(req);
1489                 goto error;
1490         }
1491
1492         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1493
1494         p9_free_req(clnt, req);
1495 error:
1496         /*
1497          * Fid is not valid even after a failed clunk
1498          * If interrupted, retry once then give up and
1499          * leak fid until umount.
1500          */
1501         if (err == -ERESTARTSYS) {
1502                 if (retries++ == 0)
1503                         goto again;
1504         } else
1505                 p9_fid_destroy(fid);
1506         return err;
1507 }
1508 EXPORT_SYMBOL(p9_client_clunk);
1509
1510 int p9_client_remove(struct p9_fid *fid)
1511 {
1512         int err;
1513         struct p9_client *clnt;
1514         struct p9_req_t *req;
1515
1516         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1517         err = 0;
1518         clnt = fid->clnt;
1519
1520         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1521         if (IS_ERR(req)) {
1522                 err = PTR_ERR(req);
1523                 goto error;
1524         }
1525
1526         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1527
1528         p9_free_req(clnt, req);
1529 error:
1530         if (err == -ERESTARTSYS)
1531                 p9_client_clunk(fid);
1532         else
1533                 p9_fid_destroy(fid);
1534         return err;
1535 }
1536 EXPORT_SYMBOL(p9_client_remove);
1537
1538 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1539 {
1540         int err = 0;
1541         struct p9_req_t *req;
1542         struct p9_client *clnt;
1543
1544         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1545                    dfid->fid, name, flags);
1546
1547         clnt = dfid->clnt;
1548         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1549         if (IS_ERR(req)) {
1550                 err = PTR_ERR(req);
1551                 goto error;
1552         }
1553         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1554
1555         p9_free_req(clnt, req);
1556 error:
1557         return err;
1558 }
1559 EXPORT_SYMBOL(p9_client_unlinkat);
1560
1561 int
1562 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1563 {
1564         struct p9_client *clnt = fid->clnt;
1565         struct p9_req_t *req;
1566         int total = 0;
1567         *err = 0;
1568
1569         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1570                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1571
1572         while (iov_iter_count(to)) {
1573                 int count = iov_iter_count(to);
1574                 int rsize, non_zc = 0;
1575                 char *dataptr;
1576
1577                 rsize = fid->iounit;
1578                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1579                         rsize = clnt->msize - P9_IOHDRSZ;
1580
1581                 if (count < rsize)
1582                         rsize = count;
1583
1584                 /* Don't bother zerocopy for small IO (< 1024) */
1585                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1586                         /*
1587                          * response header len is 11
1588                          * PDU Header(7) + IO Size (4)
1589                          */
1590                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1591                                                0, 11, "dqd", fid->fid,
1592                                                offset, rsize);
1593                 } else {
1594                         non_zc = 1;
1595                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1596                                             rsize);
1597                 }
1598                 if (IS_ERR(req)) {
1599                         *err = PTR_ERR(req);
1600                         break;
1601                 }
1602
1603                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1604                                    "D", &count, &dataptr);
1605                 if (*err) {
1606                         trace_9p_protocol_dump(clnt, req->rc);
1607                         p9_free_req(clnt, req);
1608                         break;
1609                 }
1610                 if (rsize < count) {
1611                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1612                         count = rsize;
1613                 }
1614
1615                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1616                 if (!count) {
1617                         p9_free_req(clnt, req);
1618                         break;
1619                 }
1620
1621                 if (non_zc) {
1622                         int n = copy_to_iter(dataptr, count, to);
1623                         total += n;
1624                         offset += n;
1625                         if (n != count) {
1626                                 *err = -EFAULT;
1627                                 p9_free_req(clnt, req);
1628                                 break;
1629                         }
1630                 } else {
1631                         iov_iter_advance(to, count);
1632                         total += count;
1633                         offset += count;
1634                 }
1635                 p9_free_req(clnt, req);
1636         }
1637         return total;
1638 }
1639 EXPORT_SYMBOL(p9_client_read);
1640
1641 int
1642 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1643 {
1644         struct p9_client *clnt = fid->clnt;
1645         struct p9_req_t *req;
1646         int total = 0;
1647         *err = 0;
1648
1649         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1650                                 fid->fid, (unsigned long long) offset,
1651                                 iov_iter_count(from));
1652
1653         while (iov_iter_count(from)) {
1654                 int count = iov_iter_count(from);
1655                 int rsize = fid->iounit;
1656                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1657                         rsize = clnt->msize - P9_IOHDRSZ;
1658
1659                 if (count < rsize)
1660                         rsize = count;
1661
1662                 /* Don't bother zerocopy for small IO (< 1024) */
1663                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1664                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1665                                                rsize, P9_ZC_HDR_SZ, "dqd",
1666                                                fid->fid, offset, rsize);
1667                 } else {
1668                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1669                                                     offset, rsize, from);
1670                 }
1671                 if (IS_ERR(req)) {
1672                         *err = PTR_ERR(req);
1673                         break;
1674                 }
1675
1676                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1677                 if (*err) {
1678                         trace_9p_protocol_dump(clnt, req->rc);
1679                         p9_free_req(clnt, req);
1680                         break;
1681                 }
1682                 if (rsize < count) {
1683                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1684                         count = rsize;
1685                 }
1686
1687                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1688
1689                 p9_free_req(clnt, req);
1690                 iov_iter_advance(from, count);
1691                 total += count;
1692                 offset += count;
1693         }
1694         return total;
1695 }
1696 EXPORT_SYMBOL(p9_client_write);
1697
1698 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1699 {
1700         int err;
1701         struct p9_client *clnt;
1702         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1703         struct p9_req_t *req;
1704         u16 ignored;
1705
1706         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1707
1708         if (!ret)
1709                 return ERR_PTR(-ENOMEM);
1710
1711         err = 0;
1712         clnt = fid->clnt;
1713
1714         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1715         if (IS_ERR(req)) {
1716                 err = PTR_ERR(req);
1717                 goto error;
1718         }
1719
1720         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1721         if (err) {
1722                 trace_9p_protocol_dump(clnt, req->rc);
1723                 p9_free_req(clnt, req);
1724                 goto error;
1725         }
1726
1727         p9_debug(P9_DEBUG_9P,
1728                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1729                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1730                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1731                 "<<<    uid=%d gid=%d n_muid=%d\n",
1732                 ret->size, ret->type, ret->dev, ret->qid.type,
1733                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1734                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1735                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1736                 from_kuid(&init_user_ns, ret->n_uid),
1737                 from_kgid(&init_user_ns, ret->n_gid),
1738                 from_kuid(&init_user_ns, ret->n_muid));
1739
1740         p9_free_req(clnt, req);
1741         return ret;
1742
1743 error:
1744         kfree(ret);
1745         return ERR_PTR(err);
1746 }
1747 EXPORT_SYMBOL(p9_client_stat);
1748
1749 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1750                                                         u64 request_mask)
1751 {
1752         int err;
1753         struct p9_client *clnt;
1754         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1755                                                                 GFP_KERNEL);
1756         struct p9_req_t *req;
1757
1758         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1759                                                         fid->fid, request_mask);
1760
1761         if (!ret)
1762                 return ERR_PTR(-ENOMEM);
1763
1764         err = 0;
1765         clnt = fid->clnt;
1766
1767         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1768         if (IS_ERR(req)) {
1769                 err = PTR_ERR(req);
1770                 goto error;
1771         }
1772
1773         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1774         if (err) {
1775                 trace_9p_protocol_dump(clnt, req->rc);
1776                 p9_free_req(clnt, req);
1777                 goto error;
1778         }
1779
1780         p9_debug(P9_DEBUG_9P,
1781                 "<<< RGETATTR st_result_mask=%lld\n"
1782                 "<<< qid=%x.%llx.%x\n"
1783                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1784                 "<<< st_uid=%d st_gid=%d\n"
1785                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1786                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1787                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1788                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1789                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1790                 "<<< st_gen=%lld st_data_version=%lld",
1791                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1792                 ret->qid.version, ret->st_mode, ret->st_nlink,
1793                 from_kuid(&init_user_ns, ret->st_uid),
1794                 from_kgid(&init_user_ns, ret->st_gid),
1795                 ret->st_rdev, ret->st_size, ret->st_blksize,
1796                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1797                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1798                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1799                 ret->st_gen, ret->st_data_version);
1800
1801         p9_free_req(clnt, req);
1802         return ret;
1803
1804 error:
1805         kfree(ret);
1806         return ERR_PTR(err);
1807 }
1808 EXPORT_SYMBOL(p9_client_getattr_dotl);
1809
1810 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1811 {
1812         int ret;
1813
1814         /* NOTE: size shouldn't include its own length */
1815         /* size[2] type[2] dev[4] qid[13] */
1816         /* mode[4] atime[4] mtime[4] length[8]*/
1817         /* name[s] uid[s] gid[s] muid[s] */
1818         ret = 2+4+13+4+4+4+8+2+2+2+2;
1819
1820         if (wst->name)
1821                 ret += strlen(wst->name);
1822         if (wst->uid)
1823                 ret += strlen(wst->uid);
1824         if (wst->gid)
1825                 ret += strlen(wst->gid);
1826         if (wst->muid)
1827                 ret += strlen(wst->muid);
1828
1829         if ((proto_version == p9_proto_2000u) ||
1830                 (proto_version == p9_proto_2000L)) {
1831                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1832                 if (wst->extension)
1833                         ret += strlen(wst->extension);
1834         }
1835
1836         return ret;
1837 }
1838
1839 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1840 {
1841         int err;
1842         struct p9_req_t *req;
1843         struct p9_client *clnt;
1844
1845         err = 0;
1846         clnt = fid->clnt;
1847         wst->size = p9_client_statsize(wst, clnt->proto_version);
1848         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1849         p9_debug(P9_DEBUG_9P,
1850                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1851                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1852                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1853                 "     uid=%d gid=%d n_muid=%d\n",
1854                 wst->size, wst->type, wst->dev, wst->qid.type,
1855                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1856                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1857                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1858                 from_kuid(&init_user_ns, wst->n_uid),
1859                 from_kgid(&init_user_ns, wst->n_gid),
1860                 from_kuid(&init_user_ns, wst->n_muid));
1861
1862         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1863         if (IS_ERR(req)) {
1864                 err = PTR_ERR(req);
1865                 goto error;
1866         }
1867
1868         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1869
1870         p9_free_req(clnt, req);
1871 error:
1872         return err;
1873 }
1874 EXPORT_SYMBOL(p9_client_wstat);
1875
1876 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1877 {
1878         int err;
1879         struct p9_req_t *req;
1880         struct p9_client *clnt;
1881
1882         err = 0;
1883         clnt = fid->clnt;
1884         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1885         p9_debug(P9_DEBUG_9P,
1886                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1887                 "    atime_sec=%lld atime_nsec=%lld\n"
1888                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1889                 p9attr->valid, p9attr->mode,
1890                 from_kuid(&init_user_ns, p9attr->uid),
1891                 from_kgid(&init_user_ns, p9attr->gid),
1892                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1893                 p9attr->mtime_sec, p9attr->mtime_nsec);
1894
1895         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1896
1897         if (IS_ERR(req)) {
1898                 err = PTR_ERR(req);
1899                 goto error;
1900         }
1901         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1902         p9_free_req(clnt, req);
1903 error:
1904         return err;
1905 }
1906 EXPORT_SYMBOL(p9_client_setattr);
1907
1908 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1909 {
1910         int err;
1911         struct p9_req_t *req;
1912         struct p9_client *clnt;
1913
1914         err = 0;
1915         clnt = fid->clnt;
1916
1917         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1918
1919         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1920         if (IS_ERR(req)) {
1921                 err = PTR_ERR(req);
1922                 goto error;
1923         }
1924
1925         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1926                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1927                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1928         if (err) {
1929                 trace_9p_protocol_dump(clnt, req->rc);
1930                 p9_free_req(clnt, req);
1931                 goto error;
1932         }
1933
1934         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1935                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1936                 "fsid %llu namelen %ld\n",
1937                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1938                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1939                 sb->fsid, (long int)sb->namelen);
1940
1941         p9_free_req(clnt, req);
1942 error:
1943         return err;
1944 }
1945 EXPORT_SYMBOL(p9_client_statfs);
1946
1947 int p9_client_rename(struct p9_fid *fid,
1948                      struct p9_fid *newdirfid, const char *name)
1949 {
1950         int err;
1951         struct p9_req_t *req;
1952         struct p9_client *clnt;
1953
1954         err = 0;
1955         clnt = fid->clnt;
1956
1957         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1958                         fid->fid, newdirfid->fid, name);
1959
1960         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1961                         newdirfid->fid, name);
1962         if (IS_ERR(req)) {
1963                 err = PTR_ERR(req);
1964                 goto error;
1965         }
1966
1967         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1968
1969         p9_free_req(clnt, req);
1970 error:
1971         return err;
1972 }
1973 EXPORT_SYMBOL(p9_client_rename);
1974
1975 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1976                        struct p9_fid *newdirfid, const char *new_name)
1977 {
1978         int err;
1979         struct p9_req_t *req;
1980         struct p9_client *clnt;
1981
1982         err = 0;
1983         clnt = olddirfid->clnt;
1984
1985         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1986                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1987                    newdirfid->fid, new_name);
1988
1989         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1990                             old_name, newdirfid->fid, new_name);
1991         if (IS_ERR(req)) {
1992                 err = PTR_ERR(req);
1993                 goto error;
1994         }
1995
1996         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1997                    newdirfid->fid, new_name);
1998
1999         p9_free_req(clnt, req);
2000 error:
2001         return err;
2002 }
2003 EXPORT_SYMBOL(p9_client_renameat);
2004
2005 /*
2006  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2007  */
2008 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2009                                 const char *attr_name, u64 *attr_size)
2010 {
2011         int err;
2012         struct p9_req_t *req;
2013         struct p9_client *clnt;
2014         struct p9_fid *attr_fid;
2015
2016         err = 0;
2017         clnt = file_fid->clnt;
2018         attr_fid = p9_fid_create(clnt);
2019         if (IS_ERR(attr_fid)) {
2020                 err = PTR_ERR(attr_fid);
2021                 attr_fid = NULL;
2022                 goto error;
2023         }
2024         p9_debug(P9_DEBUG_9P,
2025                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2026                 file_fid->fid, attr_fid->fid, attr_name);
2027
2028         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2029                         file_fid->fid, attr_fid->fid, attr_name);
2030         if (IS_ERR(req)) {
2031                 err = PTR_ERR(req);
2032                 goto error;
2033         }
2034         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2035         if (err) {
2036                 trace_9p_protocol_dump(clnt, req->rc);
2037                 p9_free_req(clnt, req);
2038                 goto clunk_fid;
2039         }
2040         p9_free_req(clnt, req);
2041         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2042                 attr_fid->fid, *attr_size);
2043         return attr_fid;
2044 clunk_fid:
2045         p9_client_clunk(attr_fid);
2046         attr_fid = NULL;
2047 error:
2048         if (attr_fid && (attr_fid != file_fid))
2049                 p9_fid_destroy(attr_fid);
2050
2051         return ERR_PTR(err);
2052 }
2053 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2054
2055 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2056                         u64 attr_size, int flags)
2057 {
2058         int err;
2059         struct p9_req_t *req;
2060         struct p9_client *clnt;
2061
2062         p9_debug(P9_DEBUG_9P,
2063                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2064                 fid->fid, name, (long long)attr_size, flags);
2065         err = 0;
2066         clnt = fid->clnt;
2067         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2068                         fid->fid, name, attr_size, flags);
2069         if (IS_ERR(req)) {
2070                 err = PTR_ERR(req);
2071                 goto error;
2072         }
2073         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2074         p9_free_req(clnt, req);
2075 error:
2076         return err;
2077 }
2078 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2079
2080 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2081 {
2082         int err, rsize, non_zc = 0;
2083         struct p9_client *clnt;
2084         struct p9_req_t *req;
2085         char *dataptr;
2086         struct kvec kv = {.iov_base = data, .iov_len = count};
2087         struct iov_iter to;
2088
2089         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2090
2091         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2092                                 fid->fid, (unsigned long long) offset, count);
2093
2094         err = 0;
2095         clnt = fid->clnt;
2096
2097         rsize = fid->iounit;
2098         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2099                 rsize = clnt->msize - P9_READDIRHDRSZ;
2100
2101         if (count < rsize)
2102                 rsize = count;
2103
2104         /* Don't bother zerocopy for small IO (< 1024) */
2105         if (clnt->trans_mod->zc_request && rsize > 1024) {
2106                 /*
2107                  * response header len is 11
2108                  * PDU Header(7) + IO Size (4)
2109                  */
2110                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2111                                        11, "dqd", fid->fid, offset, rsize);
2112         } else {
2113                 non_zc = 1;
2114                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2115                                     offset, rsize);
2116         }
2117         if (IS_ERR(req)) {
2118                 err = PTR_ERR(req);
2119                 goto error;
2120         }
2121
2122         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2123         if (err) {
2124                 trace_9p_protocol_dump(clnt, req->rc);
2125                 goto free_and_error;
2126         }
2127         if (rsize < count) {
2128                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2129                 count = rsize;
2130         }
2131
2132         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2133
2134         if (non_zc)
2135                 memmove(data, dataptr, count);
2136
2137         p9_free_req(clnt, req);
2138         return count;
2139
2140 free_and_error:
2141         p9_free_req(clnt, req);
2142 error:
2143         return err;
2144 }
2145 EXPORT_SYMBOL(p9_client_readdir);
2146
2147 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2148                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2149 {
2150         int err;
2151         struct p9_client *clnt;
2152         struct p9_req_t *req;
2153
2154         err = 0;
2155         clnt = fid->clnt;
2156         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2157                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2158         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2159                 MAJOR(rdev), MINOR(rdev), gid);
2160         if (IS_ERR(req))
2161                 return PTR_ERR(req);
2162
2163         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2164         if (err) {
2165                 trace_9p_protocol_dump(clnt, req->rc);
2166                 goto error;
2167         }
2168         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2169                                 (unsigned long long)qid->path, qid->version);
2170
2171 error:
2172         p9_free_req(clnt, req);
2173         return err;
2174
2175 }
2176 EXPORT_SYMBOL(p9_client_mknod_dotl);
2177
2178 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2179                                 kgid_t gid, struct p9_qid *qid)
2180 {
2181         int err;
2182         struct p9_client *clnt;
2183         struct p9_req_t *req;
2184
2185         err = 0;
2186         clnt = fid->clnt;
2187         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2188                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2189         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2190                 gid);
2191         if (IS_ERR(req))
2192                 return PTR_ERR(req);
2193
2194         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2195         if (err) {
2196                 trace_9p_protocol_dump(clnt, req->rc);
2197                 goto error;
2198         }
2199         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2200                                 (unsigned long long)qid->path, qid->version);
2201
2202 error:
2203         p9_free_req(clnt, req);
2204         return err;
2205
2206 }
2207 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2208
2209 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2210 {
2211         int err;
2212         struct p9_client *clnt;
2213         struct p9_req_t *req;
2214
2215         err = 0;
2216         clnt = fid->clnt;
2217         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2218                         "start %lld length %lld proc_id %d client_id %s\n",
2219                         fid->fid, flock->type, flock->flags, flock->start,
2220                         flock->length, flock->proc_id, flock->client_id);
2221
2222         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2223                                 flock->flags, flock->start, flock->length,
2224                                         flock->proc_id, flock->client_id);
2225
2226         if (IS_ERR(req))
2227                 return PTR_ERR(req);
2228
2229         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2230         if (err) {
2231                 trace_9p_protocol_dump(clnt, req->rc);
2232                 goto error;
2233         }
2234         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2235 error:
2236         p9_free_req(clnt, req);
2237         return err;
2238
2239 }
2240 EXPORT_SYMBOL(p9_client_lock_dotl);
2241
2242 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2243 {
2244         int err;
2245         struct p9_client *clnt;
2246         struct p9_req_t *req;
2247
2248         err = 0;
2249         clnt = fid->clnt;
2250         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2251                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2252                 glock->start, glock->length, glock->proc_id, glock->client_id);
2253
2254         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2255                 glock->start, glock->length, glock->proc_id, glock->client_id);
2256
2257         if (IS_ERR(req))
2258                 return PTR_ERR(req);
2259
2260         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2261                         &glock->start, &glock->length, &glock->proc_id,
2262                         &glock->client_id);
2263         if (err) {
2264                 trace_9p_protocol_dump(clnt, req->rc);
2265                 goto error;
2266         }
2267         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2268                 "proc_id %d client_id %s\n", glock->type, glock->start,
2269                 glock->length, glock->proc_id, glock->client_id);
2270 error:
2271         p9_free_req(clnt, req);
2272         return err;
2273 }
2274 EXPORT_SYMBOL(p9_client_getlock_dotl);
2275
2276 int p9_client_readlink(struct p9_fid *fid, char **target)
2277 {
2278         int err;
2279         struct p9_client *clnt;
2280         struct p9_req_t *req;
2281
2282         err = 0;
2283         clnt = fid->clnt;
2284         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2285
2286         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2287         if (IS_ERR(req))
2288                 return PTR_ERR(req);
2289
2290         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2291         if (err) {
2292                 trace_9p_protocol_dump(clnt, req->rc);
2293                 goto error;
2294         }
2295         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2296 error:
2297         p9_free_req(clnt, req);
2298         return err;
2299 }
2300 EXPORT_SYMBOL(p9_client_readlink);