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                         if (option < 4096) {
 185                                 p9_debug(P9_DEBUG_ERROR,
 186                                          "msize should be at least 4k\n");
 187                                 ret = -EINVAL;
 188                                 continue;
 189                         }
 190                         clnt->msize = option;
 191                         break;
 192                 case Opt_trans:
 193                         s = match_strdup(&args[0]);
 194                         if (!s) {
 195                                 ret = -ENOMEM;
 196                                 p9_debug(P9_DEBUG_ERROR,
 197                                          "problem allocating copy of trans arg\n");
 198                                 goto free_and_return;
 199                          }
 200                         clnt->trans_mod = v9fs_get_trans_by_name(s);
 201                         if (clnt->trans_mod == NULL) {
 202                                 pr_info("Could not find request transport: %s\n",
 203                                         s);
 204                                 ret = -EINVAL;
 205                                 kfree(s);
 206                                 goto free_and_return;
 207                         }
 208                         kfree(s);
 209                         break;
 210                 case Opt_legacy:
 211                         clnt->proto_version = p9_proto_legacy;
 212                         break;
 213                 case Opt_version:
 214                         s = match_strdup(&args[0]);
 215                         if (!s) {
 216                                 ret = -ENOMEM;
 217                                 p9_debug(P9_DEBUG_ERROR,
 218                                          "problem allocating copy of version arg\n");
 219                                 goto free_and_return;
 220                         }
 221                         ret = get_protocol_version(s);
 222                         if (ret == -EINVAL) {
 223                                 kfree(s);
 224                                 goto free_and_return;
 225                         }
 226                         kfree(s);
 227                         clnt->proto_version = ret;
 228                         break;
 229                 default:
 230                         continue;
 231                 }
 232         }
 233
 234 free_and_return:
 235         kfree(tmp_options);
 236         return ret;
 237 }
 238
 239 static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
 240 {
 241         struct p9_fcall *fc;
 242         fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
 243         if (!fc)
 244                 return NULL;
 245         fc->capacity = alloc_msize;
 246         fc->sdata = (char *) fc + sizeof(struct p9_fcall);
 247         return fc;
 248 }
 249
 250 /**
 251  * p9_tag_alloc - lookup/allocate a request by tag
 252  * @c: client session to lookup tag within
 253  * @tag: numeric id for transaction
 254  *
 255  * this is a simple array lookup, but will grow the
 256  * request_slots as necessary to accommodate transaction
 257  * ids which did not previously have a slot.
 258  *
 259  * this code relies on the client spinlock to manage locks, its
 260  * possible we should switch to something else, but I'd rather
 261  * stick with something low-overhead for the common case.
 262  *
 263  */
 264
 265 static struct p9_req_t *
 266 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
 267 {
 268         unsigned long flags;
 269         int row, col;
 270         struct p9_req_t *req;
 271         int alloc_msize = min(c->msize, max_size);
 272
 273         /* This looks up the original request by tag so we know which
 274          * buffer to read the data into */
 275         tag++;
 276
 277         if (tag >= c->max_tag) {
 278                 spin_lock_irqsave(&c->lock, flags);
 279                 /* check again since original check was outside of lock */
 280                 while (tag >= c->max_tag) {
 281                         row = (tag / P9_ROW_MAXTAG);
 282                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 283                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 284
 285                         if (!c->reqs[row]) {
 286                                 pr_err("Couldn't grow tag array\n");
 287                                 spin_unlock_irqrestore(&c->lock, flags);
 288                                 return ERR_PTR(-ENOMEM);
 289                         }
 290                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 291                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 292                                 c->reqs[row][col].tc = NULL;
 293                         }
 294                         c->max_tag += P9_ROW_MAXTAG;
 295                 }
 296                 spin_unlock_irqrestore(&c->lock, flags);
 297         }
 298         row = tag / P9_ROW_MAXTAG;
 299         col = tag % P9_ROW_MAXTAG;
 300
 301         req = &c->reqs[row][col];
 302         if (!req->wq) {
 303                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
 304                 if (!req->wq)
 305                         goto grow_failed;
 306                 init_waitqueue_head(req->wq);
 307         }
 308
 309         if (!req->tc)
 310                 req->tc = p9_fcall_alloc(alloc_msize);
 311         if (!req->rc)
 312                 req->rc = p9_fcall_alloc(alloc_msize);
 313         if (!req->tc || !req->rc)
 314                 goto grow_failed;
 315
 316         p9pdu_reset(req->tc);
 317         p9pdu_reset(req->rc);
 318
 319         req->tc->tag = tag-1;
 320         req->status = REQ_STATUS_ALLOC;
 321
 322         return req;
 323
 324 grow_failed:
 325         pr_err("Couldn't grow tag array\n");
 326         kfree(req->tc);
 327         kfree(req->rc);
 328         kfree(req->wq);
 329         req->tc = req->rc = NULL;
 330         req->wq = NULL;
 331         return ERR_PTR(-ENOMEM);
 332 }
 333
 334 /**
 335  * p9_tag_lookup - lookup a request by tag
 336  * @c: client session to lookup tag within
 337  * @tag: numeric id for transaction
 338  *
 339  */
 340
 341 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 342 {
 343         int row, col;
 344
 345         /* This looks up the original request by tag so we know which
 346          * buffer to read the data into */
 347         tag++;
 348
 349         if(tag >= c->max_tag)
 350                 return NULL;
 351
 352         row = tag / P9_ROW_MAXTAG;
 353         col = tag % P9_ROW_MAXTAG;
 354
 355         return &c->reqs[row][col];
 356 }
 357 EXPORT_SYMBOL(p9_tag_lookup);
 358
 359 /**
 360  * p9_tag_init - setup tags structure and contents
 361  * @c:  v9fs client struct
 362  *
 363  * This initializes the tags structure for each client instance.
 364  *
 365  */
 366
 367 static int p9_tag_init(struct p9_client *c)
 368 {
 369         int err = 0;
 370
 371         c->tagpool = p9_idpool_create();
 372         if (IS_ERR(c->tagpool)) {
 373                 err = PTR_ERR(c->tagpool);
 374                 goto error;
 375         }
 376         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
 377         if (err < 0) {
 378                 p9_idpool_destroy(c->tagpool);
 379                 goto error;
 380         }
 381         c->max_tag = 0;
 382 error:
 383         return err;
 384 }
 385
 386 /**
 387  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 388  * @c:  v9fs client struct
 389  *
 390  * This frees resources associated with the tags structure
 391  *
 392  */
 393 static void p9_tag_cleanup(struct p9_client *c)
 394 {
 395         int row, col;
 396
 397         /* check to insure all requests are idle */
 398         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 399                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 400                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 401                                 p9_debug(P9_DEBUG_MUX,
 402                                          "Attempting to cleanup non-free tag %d,%d\n",
 403                                          row, col);
 404                                 /* TODO: delay execution of cleanup */
 405                                 return;
 406                         }
 407                 }
 408         }
 409
 410         if (c->tagpool) {
 411                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
 412                 p9_idpool_destroy(c->tagpool);
 413         }
 414
 415         /* free requests associated with tags */
 416         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 417                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 418                         kfree(c->reqs[row][col].wq);
 419                         kfree(c->reqs[row][col].tc);
 420                         kfree(c->reqs[row][col].rc);
 421                 }
 422                 kfree(c->reqs[row]);
 423         }
 424         c->max_tag = 0;
 425 }
 426
 427 /**
 428  * p9_free_req - free a request and clean-up as necessary
 429  * c: client state
 430  * r: request to release
 431  *
 432  */
 433
 434 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 435 {
 436         int tag = r->tc->tag;
 437         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 438
 439         r->status = REQ_STATUS_IDLE;
 440         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 441                 p9_idpool_put(tag, c->tagpool);
 442 }
 443
 444 /**
 445  * p9_client_cb - call back from transport to client
 446  * c: client state
 447  * req: request received
 448  *
 449  */
 450 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 451 {
 452         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 453
 454         /*
 455          * This barrier is needed to make sure any change made to req before
 456          * the other thread wakes up will indeed be seen by the waiting side.
 457          */
 458         smp_wmb();
 459         req->status = status;
 460
 461         wake_up(req->wq);
 462         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 463 }
 464 EXPORT_SYMBOL(p9_client_cb);
 465
 466 /**
 467  * p9_parse_header - parse header arguments out of a packet
 468  * @pdu: packet to parse
 469  * @size: size of packet
 470  * @type: type of request
 471  * @tag: tag of packet
 472  * @rewind: set if we need to rewind offset afterwards
 473  */
 474
 475 int
 476 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 477                                                                 int rewind)
 478 {
 479         int8_t r_type;
 480         int16_t r_tag;
 481         int32_t r_size;
 482         int offset = pdu->offset;
 483         int err;
 484
 485         pdu->offset = 0;
 486         if (pdu->size == 0)
 487                 pdu->size = 7;
 488
 489         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 490         if (err)
 491                 goto rewind_and_exit;
 492
 493         pdu->size = r_size;
 494         pdu->id = r_type;
 495         pdu->tag = r_tag;
 496
 497         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 498                  pdu->size, pdu->id, pdu->tag);
 499
 500         if (type)
 501                 *type = r_type;
 502         if (tag)
 503                 *tag = r_tag;
 504         if (size)
 505                 *size = r_size;
 506
 507
 508 rewind_and_exit:
 509         if (rewind)
 510                 pdu->offset = offset;
 511         return err;
 512 }
 513 EXPORT_SYMBOL(p9_parse_header);
 514
 515 /**
 516  * p9_check_errors - check 9p packet for error return and process it
 517  * @c: current client instance
 518  * @req: request to parse and check for error conditions
 519  *
 520  * returns error code if one is discovered, otherwise returns 0
 521  *
 522  * this will have to be more complicated if we have multiple
 523  * error packet types
 524  */
 525
 526 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 527 {
 528         int8_t type;
 529         int err;
 530         int ecode;
 531
 532         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 533         /*
 534          * dump the response from server
 535          * This should be after check errors which poplulate pdu_fcall.
 536          */
 537         trace_9p_protocol_dump(c, req->rc);
 538         if (err) {
 539                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 540                 return err;
 541         }
 542         if (type != P9_RERROR && type != P9_RLERROR)
 543                 return 0;
 544
 545         if (!p9_is_proto_dotl(c)) {
 546                 char *ename;
 547                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 548                                   &ename, &ecode);
 549                 if (err)
 550                         goto out_err;
 551
 552                 if (p9_is_proto_dotu(c) && ecode < 512)
 553                         err = -ecode;
 554
 555                 if (!err) {
 556                         err = p9_errstr2errno(ename, strlen(ename));
 557
 558                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 559                                  -ecode, ename);
 560                 }
 561                 kfree(ename);
 562         } else {
 563                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 564                 err = -ecode;
 565
 566                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 567         }
 568
 569         return err;
 570
 571 out_err:
 572         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 573
 574         return err;
 575 }
 576
 577 /**
 578  * p9_check_zc_errors - check 9p packet for error return and process it
 579  * @c: current client instance
 580  * @req: request to parse and check for error conditions
 581  * @in_hdrlen: Size of response protocol buffer.
 582  *
 583  * returns error code if one is discovered, otherwise returns 0
 584  *
 585  * this will have to be more complicated if we have multiple
 586  * error packet types
 587  */
 588
 589 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 590                               struct iov_iter *uidata, int in_hdrlen)
 591 {
 592         int err;
 593         int ecode;
 594         int8_t type;
 595         char *ename = NULL;
 596
 597         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 598         /*
 599          * dump the response from server
 600          * This should be after parse_header which poplulate pdu_fcall.
 601          */
 602         trace_9p_protocol_dump(c, req->rc);
 603         if (err) {
 604                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 605                 return err;
 606         }
 607
 608         if (type != P9_RERROR && type != P9_RLERROR)
 609                 return 0;
 610
 611         if (!p9_is_proto_dotl(c)) {
 612                 /* Error is reported in string format */
 613                 int len;
 614                 /* 7 = header size for RERROR; */
 615                 int inline_len = in_hdrlen - 7;
 616
 617                 len =  req->rc->size - req->rc->offset;
 618                 if (len > (P9_ZC_HDR_SZ - 7)) {
 619                         err = -EFAULT;
 620                         goto out_err;
 621                 }
 622
 623                 ename = &req->rc->sdata[req->rc->offset];
 624                 if (len > inline_len) {
 625                         /* We have error in external buffer */
 626                         if (!copy_from_iter_full(ename + inline_len,
 627                                              len - inline_len, uidata)) {
 628                                 err = -EFAULT;
 629                                 goto out_err;
 630                         }
 631                 }
 632                 ename = NULL;
 633                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 634                                   &ename, &ecode);
 635                 if (err)
 636                         goto out_err;
 637
 638                 if (p9_is_proto_dotu(c) && ecode < 512)
 639                         err = -ecode;
 640
 641                 if (!err) {
 642                         err = p9_errstr2errno(ename, strlen(ename));
 643
 644                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 645                                  -ecode, ename);
 646                 }
 647                 kfree(ename);
 648         } else {
 649                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 650                 err = -ecode;
 651
 652                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 653         }
 654         return err;
 655
 656 out_err:
 657         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 658         return err;
 659 }
 660
 661 static struct p9_req_t *
 662 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 663
 664 /**
 665  * p9_client_flush - flush (cancel) a request
 666  * @c: client state
 667  * @oldreq: request to cancel
 668  *
 669  * This sents a flush for a particular request and links
 670  * the flush request to the original request.  The current
 671  * code only supports a single flush request although the protocol
 672  * allows for multiple flush requests to be sent for a single request.
 673  *
 674  */
 675
 676 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 677 {
 678         struct p9_req_t *req;
 679         int16_t oldtag;
 680         int err;
 681
 682         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 683         if (err)
 684                 return err;
 685
 686         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 687
 688         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 689         if (IS_ERR(req))
 690                 return PTR_ERR(req);
 691
 692         /*
 693          * if we haven't received a response for oldreq,
 694          * remove it from the list
 695          */
 696         if (oldreq->status == REQ_STATUS_SENT)
 697                 if (c->trans_mod->cancelled)
 698                         c->trans_mod->cancelled(c, oldreq);
 699
 700         p9_free_req(c, req);
 701         return 0;
 702 }
 703
 704 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 705                                               int8_t type, int req_size,
 706                                               const char *fmt, va_list ap)
 707 {
 708         int tag, err;
 709         struct p9_req_t *req;
 710
 711         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 712
 713         /* we allow for any status other than disconnected */
 714         if (c->status == Disconnected)
 715                 return ERR_PTR(-EIO);
 716
 717         /* if status is begin_disconnected we allow only clunk request */
 718         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 719                 return ERR_PTR(-EIO);
 720
 721         tag = P9_NOTAG;
 722         if (type != P9_TVERSION) {
 723                 tag = p9_idpool_get(c->tagpool);
 724                 if (tag < 0)
 725                         return ERR_PTR(-ENOMEM);
 726         }
 727
 728         req = p9_tag_alloc(c, tag, req_size);
 729         if (IS_ERR(req))
 730                 return req;
 731
 732         /* marshall the data */
 733         p9pdu_prepare(req->tc, tag, type);
 734         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 735         if (err)
 736                 goto reterr;
 737         p9pdu_finalize(c, req->tc);
 738         trace_9p_client_req(c, type, tag);
 739         return req;
 740 reterr:
 741         p9_free_req(c, req);
 742         return ERR_PTR(err);
 743 }
 744
 745 /**
 746  * p9_client_rpc - issue a request and wait for a response
 747  * @c: client session
 748  * @type: type of request
 749  * @fmt: protocol format string (see protocol.c)
 750  *
 751  * Returns request structure (which client must free using p9_free_req)
 752  */
 753
 754 static struct p9_req_t *
 755 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 756 {
 757         va_list ap;
 758         int sigpending, err;
 759         unsigned long flags;
 760         struct p9_req_t *req;
 761
 762         va_start(ap, fmt);
 763         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 764         va_end(ap);
 765         if (IS_ERR(req))
 766                 return req;
 767
 768         if (signal_pending(current)) {
 769                 sigpending = 1;
 770                 clear_thread_flag(TIF_SIGPENDING);
 771         } else
 772                 sigpending = 0;
 773
 774         err = c->trans_mod->request(c, req);
 775         if (err < 0) {
 776                 if (err != -ERESTARTSYS && err != -EFAULT)
 777                         c->status = Disconnected;
 778                 goto reterr;
 779         }
 780 again:
 781         /* Wait for the response */
 782         err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD);
 783
 784         /*
 785          * Make sure our req is coherent with regard to updates in other
 786          * threads - echoes to wmb() in the callback
 787          */
 788         smp_rmb();
 789
 790         if ((err == -ERESTARTSYS) && (c->status == Connected)
 791                                   && (type == P9_TFLUSH)) {
 792                 sigpending = 1;
 793                 clear_thread_flag(TIF_SIGPENDING);
 794                 goto again;
 795         }
 796
 797         if (req->status == REQ_STATUS_ERROR) {
 798                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 799                 err = req->t_err;
 800         }
 801         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 802                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 803                 sigpending = 1;
 804                 clear_thread_flag(TIF_SIGPENDING);
 805
 806                 if (c->trans_mod->cancel(c, req))
 807                         p9_client_flush(c, req);
 808
 809                 /* if we received the response anyway, don't signal error */
 810                 if (req->status == REQ_STATUS_RCVD)
 811                         err = 0;
 812         }
 813         if (sigpending) {
 814                 spin_lock_irqsave(&current->sighand->siglock, flags);
 815                 recalc_sigpending();
 816                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 817         }
 818         if (err < 0)
 819                 goto reterr;
 820
 821         err = p9_check_errors(c, req);
 822         trace_9p_client_res(c, type, req->rc->tag, err);
 823         if (!err)
 824                 return req;
 825 reterr:
 826         p9_free_req(c, req);
 827         return ERR_PTR(safe_errno(err));
 828 }
 829
 830 /**
 831  * p9_client_zc_rpc - issue a request and wait for a response
 832  * @c: client session
 833  * @type: type of request
 834  * @uidata: destination for zero copy read
 835  * @uodata: source for zero copy write
 836  * @inlen: read buffer size
 837  * @olen: write buffer size
 838  * @hdrlen: reader header size, This is the size of response protocol data
 839  * @fmt: protocol format string (see protocol.c)
 840  *
 841  * Returns request structure (which client must free using p9_free_req)
 842  */
 843 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 844                                          struct iov_iter *uidata,
 845                                          struct iov_iter *uodata,
 846                                          int inlen, int olen, int in_hdrlen,
 847                                          const char *fmt, ...)
 848 {
 849         va_list ap;
 850         int sigpending, err;
 851         unsigned long flags;
 852         struct p9_req_t *req;
 853
 854         va_start(ap, fmt);
 855         /*
 856          * We allocate a inline protocol data of only 4k bytes.
 857          * The actual content is passed in zero-copy fashion.
 858          */
 859         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 860         va_end(ap);
 861         if (IS_ERR(req))
 862                 return req;
 863
 864         if (signal_pending(current)) {
 865                 sigpending = 1;
 866                 clear_thread_flag(TIF_SIGPENDING);
 867         } else
 868                 sigpending = 0;
 869
 870         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 871                                        inlen, olen, in_hdrlen);
 872         if (err < 0) {
 873                 if (err == -EIO)
 874                         c->status = Disconnected;
 875                 if (err != -ERESTARTSYS)
 876                         goto reterr;
 877         }
 878         if (req->status == REQ_STATUS_ERROR) {
 879                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 880                 err = req->t_err;
 881         }
 882         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 883                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 884                 sigpending = 1;
 885                 clear_thread_flag(TIF_SIGPENDING);
 886
 887                 if (c->trans_mod->cancel(c, req))
 888                         p9_client_flush(c, req);
 889
 890                 /* if we received the response anyway, don't signal error */
 891                 if (req->status == REQ_STATUS_RCVD)
 892                         err = 0;
 893         }
 894         if (sigpending) {
 895                 spin_lock_irqsave(&current->sighand->siglock, flags);
 896                 recalc_sigpending();
 897                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 898         }
 899         if (err < 0)
 900                 goto reterr;
 901
 902         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 903         trace_9p_client_res(c, type, req->rc->tag, err);
 904         if (!err)
 905                 return req;
 906 reterr:
 907         p9_free_req(c, req);
 908         return ERR_PTR(safe_errno(err));
 909 }
 910
 911 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 912 {
 913         int ret;
 914         struct p9_fid *fid;
 915         unsigned long flags;
 916
 917         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 918         fid = kzalloc(sizeof(struct p9_fid), GFP_KERNEL);
 919         if (!fid)
 920                 return ERR_PTR(-ENOMEM);
 921
 922         ret = p9_idpool_get(clnt->fidpool);
 923         if (ret < 0) {
 924                 ret = -ENOSPC;
 925                 goto error;
 926         }
 927         fid->fid = ret;
 928
 929         fid->mode = -1;
 930         fid->uid = current_fsuid();
 931         fid->clnt = clnt;
 932         spin_lock_irqsave(&clnt->lock, flags);
 933         list_add(&fid->flist, &clnt->fidlist);
 934         spin_unlock_irqrestore(&clnt->lock, flags);
 935
 936         return fid;
 937
 938 error:
 939         kfree(fid);
 940         return ERR_PTR(ret);
 941 }
 942
 943 static void p9_fid_destroy(struct p9_fid *fid)
 944 {
 945         struct p9_client *clnt;
 946         unsigned long flags;
 947
 948         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 949         clnt = fid->clnt;
 950         p9_idpool_put(fid->fid, clnt->fidpool);
 951         spin_lock_irqsave(&clnt->lock, flags);
 952         list_del(&fid->flist);
 953         spin_unlock_irqrestore(&clnt->lock, flags);
 954         kfree(fid->rdir);
 955         kfree(fid);
 956 }
 957
 958 static int p9_client_version(struct p9_client *c)
 959 {
 960         int err = 0;
 961         struct p9_req_t *req;
 962         char *version = NULL;
 963         int msize;
 964
 965         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 966                  c->msize, c->proto_version);
 967
 968         switch (c->proto_version) {
 969         case p9_proto_2000L:
 970                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 971                                         c->msize, "9P2000.L");
 972                 break;
 973         case p9_proto_2000u:
 974                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 975                                         c->msize, "9P2000.u");
 976                 break;
 977         case p9_proto_legacy:
 978                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 979                                         c->msize, "9P2000");
 980                 break;
 981         default:
 982                 return -EINVAL;
 983         }
 984
 985         if (IS_ERR(req))
 986                 return PTR_ERR(req);
 987
 988         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 989         if (err) {
 990                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 991                 trace_9p_protocol_dump(c, req->rc);
 992                 goto error;
 993         }
 994
 995         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 996         if (!strncmp(version, "9P2000.L", 8))
 997                 c->proto_version = p9_proto_2000L;
 998         else if (!strncmp(version, "9P2000.u", 8))
 999                 c->proto_version = p9_proto_2000u;
1000         else if (!strncmp(version, "9P2000", 6))
1001                 c->proto_version = p9_proto_legacy;
1002         else {
1003                 p9_debug(P9_DEBUG_ERROR,
1004                          "server returned an unknown version: %s\n", version);
1005                 err = -EREMOTEIO;
1006                 goto error;
1007         }
1008
1009         if (msize < 4096) {
1010                 p9_debug(P9_DEBUG_ERROR,
1011                          "server returned a msize < 4096: %d\n", msize);
1012                 err = -EREMOTEIO;
1013                 goto error;
1014         }
1015         if (msize < c->msize)
1016                 c->msize = msize;
1017
1018 error:
1019         kfree(version);
1020         p9_free_req(c, req);
1021
1022         return err;
1023 }
1024
1025 struct p9_client *p9_client_create(const char *dev_name, char *options)
1026 {
1027         int err;
1028         struct p9_client *clnt;
1029         char *client_id;
1030
1031         err = 0;
1032         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1033         if (!clnt)
1034                 return ERR_PTR(-ENOMEM);
1035
1036         clnt->trans_mod = NULL;
1037         clnt->trans = NULL;
1038
1039         client_id = utsname()->nodename;
1040         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1041
1042         spin_lock_init(&clnt->lock);
1043         INIT_LIST_HEAD(&clnt->fidlist);
1044
1045         err = p9_tag_init(clnt);
1046         if (err < 0)
1047                 goto free_client;
1048
1049         err = parse_opts(options, clnt);
1050         if (err < 0)
1051                 goto destroy_tagpool;
1052
1053         if (!clnt->trans_mod)
1054                 clnt->trans_mod = v9fs_get_default_trans();
1055
1056         if (clnt->trans_mod == NULL) {
1057                 err = -EPROTONOSUPPORT;
1058                 p9_debug(P9_DEBUG_ERROR,
1059                          "No transport defined or default transport\n");
1060                 goto destroy_tagpool;
1061         }
1062
1063         clnt->fidpool = p9_idpool_create();
1064         if (IS_ERR(clnt->fidpool)) {
1065                 err = PTR_ERR(clnt->fidpool);
1066                 goto put_trans;
1067         }
1068
1069         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1070                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1071
1072         err = clnt->trans_mod->create(clnt, dev_name, options);
1073         if (err)
1074                 goto destroy_fidpool;
1075
1076         if (clnt->msize > clnt->trans_mod->maxsize)
1077                 clnt->msize = clnt->trans_mod->maxsize;
1078
1079         if (clnt->msize < 4096) {
1080                 p9_debug(P9_DEBUG_ERROR,
1081                          "Please specify a msize of at least 4k\n");
1082                 err = -EINVAL;
1083                 goto close_trans;
1084         }
1085
1086         err = p9_client_version(clnt);
1087         if (err)
1088                 goto close_trans;
1089
1090         return clnt;
1091
1092 close_trans:
1093         clnt->trans_mod->close(clnt);
1094 destroy_fidpool:
1095         p9_idpool_destroy(clnt->fidpool);
1096 put_trans:
1097         v9fs_put_trans(clnt->trans_mod);
1098 destroy_tagpool:
1099         p9_idpool_destroy(clnt->tagpool);
1100 free_client:
1101         kfree(clnt);
1102         return ERR_PTR(err);
1103 }
1104 EXPORT_SYMBOL(p9_client_create);
1105
1106 void p9_client_destroy(struct p9_client *clnt)
1107 {
1108         struct p9_fid *fid, *fidptr;
1109
1110         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1111
1112         if (clnt->trans_mod)
1113                 clnt->trans_mod->close(clnt);
1114
1115         v9fs_put_trans(clnt->trans_mod);
1116
1117         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1118                 pr_info("Found fid %d not clunked\n", fid->fid);
1119                 p9_fid_destroy(fid);
1120         }
1121
1122         if (clnt->fidpool)
1123                 p9_idpool_destroy(clnt->fidpool);
1124
1125         p9_tag_cleanup(clnt);
1126
1127         kfree(clnt);
1128 }
1129 EXPORT_SYMBOL(p9_client_destroy);
1130
1131 void p9_client_disconnect(struct p9_client *clnt)
1132 {
1133         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1134         clnt->status = Disconnected;
1135 }
1136 EXPORT_SYMBOL(p9_client_disconnect);
1137
1138 void p9_client_begin_disconnect(struct p9_client *clnt)
1139 {
1140         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1141         clnt->status = BeginDisconnect;
1142 }
1143 EXPORT_SYMBOL(p9_client_begin_disconnect);
1144
1145 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1146         const char *uname, kuid_t n_uname, const char *aname)
1147 {
1148         int err = 0;
1149         struct p9_req_t *req;
1150         struct p9_fid *fid;
1151         struct p9_qid qid;
1152
1153
1154         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1155                  afid ? afid->fid : -1, uname, aname);
1156         fid = p9_fid_create(clnt);
1157         if (IS_ERR(fid)) {
1158                 err = PTR_ERR(fid);
1159                 fid = NULL;
1160                 goto error;
1161         }
1162         fid->uid = n_uname;
1163
1164         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1165                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1166         if (IS_ERR(req)) {
1167                 err = PTR_ERR(req);
1168                 goto error;
1169         }
1170
1171         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1172         if (err) {
1173                 trace_9p_protocol_dump(clnt, req->rc);
1174                 p9_free_req(clnt, req);
1175                 goto error;
1176         }
1177
1178         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1179                  qid.type, (unsigned long long)qid.path, qid.version);
1180
1181         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1182
1183         p9_free_req(clnt, req);
1184         return fid;
1185
1186 error:
1187         if (fid)
1188                 p9_fid_destroy(fid);
1189         return ERR_PTR(err);
1190 }
1191 EXPORT_SYMBOL(p9_client_attach);
1192
1193 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1194                 const unsigned char * const *wnames, int clone)
1195 {
1196         int err;
1197         struct p9_client *clnt;
1198         struct p9_fid *fid;
1199         struct p9_qid *wqids;
1200         struct p9_req_t *req;
1201         uint16_t nwqids, count;
1202
1203         err = 0;
1204         wqids = NULL;
1205         clnt = oldfid->clnt;
1206         if (clone) {
1207                 fid = p9_fid_create(clnt);
1208                 if (IS_ERR(fid)) {
1209                         err = PTR_ERR(fid);
1210                         fid = NULL;
1211                         goto error;
1212                 }
1213
1214                 fid->uid = oldfid->uid;
1215         } else
1216                 fid = oldfid;
1217
1218
1219         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1220                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1221
1222         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1223                                                                 nwname, wnames);
1224         if (IS_ERR(req)) {
1225                 err = PTR_ERR(req);
1226                 goto error;
1227         }
1228
1229         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1230         if (err) {
1231                 trace_9p_protocol_dump(clnt, req->rc);
1232                 p9_free_req(clnt, req);
1233                 goto clunk_fid;
1234         }
1235         p9_free_req(clnt, req);
1236
1237         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1238
1239         if (nwqids != nwname) {
1240                 err = -ENOENT;
1241                 goto clunk_fid;
1242         }
1243
1244         for (count = 0; count < nwqids; count++)
1245                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1246                         count, wqids[count].type,
1247                         (unsigned long long)wqids[count].path,
1248                         wqids[count].version);
1249
1250         if (nwname)
1251                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1252         else
1253                 fid->qid = oldfid->qid;
1254
1255         kfree(wqids);
1256         return fid;
1257
1258 clunk_fid:
1259         kfree(wqids);
1260         p9_client_clunk(fid);
1261         fid = NULL;
1262
1263 error:
1264         if (fid && (fid != oldfid))
1265                 p9_fid_destroy(fid);
1266
1267         return ERR_PTR(err);
1268 }
1269 EXPORT_SYMBOL(p9_client_walk);
1270
1271 int p9_client_open(struct p9_fid *fid, int mode)
1272 {
1273         int err;
1274         struct p9_client *clnt;
1275         struct p9_req_t *req;
1276         struct p9_qid qid;
1277         int iounit;
1278
1279         clnt = fid->clnt;
1280         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1281                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1282         err = 0;
1283
1284         if (fid->mode != -1)
1285                 return -EINVAL;
1286
1287         if (p9_is_proto_dotl(clnt))
1288                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1289         else
1290                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1291         if (IS_ERR(req)) {
1292                 err = PTR_ERR(req);
1293                 goto error;
1294         }
1295
1296         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1297         if (err) {
1298                 trace_9p_protocol_dump(clnt, req->rc);
1299                 goto free_and_error;
1300         }
1301
1302         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1303                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1304                 (unsigned long long)qid.path, qid.version, iounit);
1305
1306         fid->mode = mode;
1307         fid->iounit = iounit;
1308
1309 free_and_error:
1310         p9_free_req(clnt, req);
1311 error:
1312         return err;
1313 }
1314 EXPORT_SYMBOL(p9_client_open);
1315
1316 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1317                 kgid_t gid, struct p9_qid *qid)
1318 {
1319         int err = 0;
1320         struct p9_client *clnt;
1321         struct p9_req_t *req;
1322         int iounit;
1323
1324         p9_debug(P9_DEBUG_9P,
1325                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1326                         ofid->fid, name, flags, mode,
1327                         from_kgid(&init_user_ns, gid));
1328         clnt = ofid->clnt;
1329
1330         if (ofid->mode != -1)
1331                 return -EINVAL;
1332
1333         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1334                         mode, gid);
1335         if (IS_ERR(req)) {
1336                 err = PTR_ERR(req);
1337                 goto error;
1338         }
1339
1340         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1341         if (err) {
1342                 trace_9p_protocol_dump(clnt, req->rc);
1343                 goto free_and_error;
1344         }
1345
1346         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1347                         qid->type,
1348                         (unsigned long long)qid->path,
1349                         qid->version, iounit);
1350
1351         ofid->mode = mode;
1352         ofid->iounit = iounit;
1353
1354 free_and_error:
1355         p9_free_req(clnt, req);
1356 error:
1357         return err;
1358 }
1359 EXPORT_SYMBOL(p9_client_create_dotl);
1360
1361 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1362                      char *extension)
1363 {
1364         int err;
1365         struct p9_client *clnt;
1366         struct p9_req_t *req;
1367         struct p9_qid qid;
1368         int iounit;
1369
1370         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1371                                                 fid->fid, name, perm, mode);
1372         err = 0;
1373         clnt = fid->clnt;
1374
1375         if (fid->mode != -1)
1376                 return -EINVAL;
1377
1378         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1379                                 mode, extension);
1380         if (IS_ERR(req)) {
1381                 err = PTR_ERR(req);
1382                 goto error;
1383         }
1384
1385         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1386         if (err) {
1387                 trace_9p_protocol_dump(clnt, req->rc);
1388                 goto free_and_error;
1389         }
1390
1391         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1392                                 qid.type,
1393                                 (unsigned long long)qid.path,
1394                                 qid.version, iounit);
1395
1396         fid->mode = mode;
1397         fid->iounit = iounit;
1398
1399 free_and_error:
1400         p9_free_req(clnt, req);
1401 error:
1402         return err;
1403 }
1404 EXPORT_SYMBOL(p9_client_fcreate);
1405
1406 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1407                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1408 {
1409         int err = 0;
1410         struct p9_client *clnt;
1411         struct p9_req_t *req;
1412
1413         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1414                         dfid->fid, name, symtgt);
1415         clnt = dfid->clnt;
1416
1417         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1418                         gid);
1419         if (IS_ERR(req)) {
1420                 err = PTR_ERR(req);
1421                 goto error;
1422         }
1423
1424         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1425         if (err) {
1426                 trace_9p_protocol_dump(clnt, req->rc);
1427                 goto free_and_error;
1428         }
1429
1430         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1431                         qid->type, (unsigned long long)qid->path, qid->version);
1432
1433 free_and_error:
1434         p9_free_req(clnt, req);
1435 error:
1436         return err;
1437 }
1438 EXPORT_SYMBOL(p9_client_symlink);
1439
1440 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1441 {
1442         struct p9_client *clnt;
1443         struct p9_req_t *req;
1444
1445         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1446                         dfid->fid, oldfid->fid, newname);
1447         clnt = dfid->clnt;
1448         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1449                         newname);
1450         if (IS_ERR(req))
1451                 return PTR_ERR(req);
1452
1453         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1454         p9_free_req(clnt, req);
1455         return 0;
1456 }
1457 EXPORT_SYMBOL(p9_client_link);
1458
1459 int p9_client_fsync(struct p9_fid *fid, int datasync)
1460 {
1461         int err;
1462         struct p9_client *clnt;
1463         struct p9_req_t *req;
1464
1465         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1466                         fid->fid, datasync);
1467         err = 0;
1468         clnt = fid->clnt;
1469
1470         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1471         if (IS_ERR(req)) {
1472                 err = PTR_ERR(req);
1473                 goto error;
1474         }
1475
1476         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1477
1478         p9_free_req(clnt, req);
1479
1480 error:
1481         return err;
1482 }
1483 EXPORT_SYMBOL(p9_client_fsync);
1484
1485 int p9_client_clunk(struct p9_fid *fid)
1486 {
1487         int err;
1488         struct p9_client *clnt;
1489         struct p9_req_t *req;
1490         int retries = 0;
1491
1492         if (!fid) {
1493                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1494                         __func__, task_pid_nr(current));
1495                 dump_stack();
1496                 return 0;
1497         }
1498
1499 again:
1500         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1501                                                                 retries);
1502         err = 0;
1503         clnt = fid->clnt;
1504
1505         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1506         if (IS_ERR(req)) {
1507                 err = PTR_ERR(req);
1508                 goto error;
1509         }
1510
1511         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1512
1513         p9_free_req(clnt, req);
1514 error:
1515         /*
1516          * Fid is not valid even after a failed clunk
1517          * If interrupted, retry once then give up and
1518          * leak fid until umount.
1519          */
1520         if (err == -ERESTARTSYS) {
1521                 if (retries++ == 0)
1522                         goto again;
1523         } else
1524                 p9_fid_destroy(fid);
1525         return err;
1526 }
1527 EXPORT_SYMBOL(p9_client_clunk);
1528
1529 int p9_client_remove(struct p9_fid *fid)
1530 {
1531         int err;
1532         struct p9_client *clnt;
1533         struct p9_req_t *req;
1534
1535         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1536         err = 0;
1537         clnt = fid->clnt;
1538
1539         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1540         if (IS_ERR(req)) {
1541                 err = PTR_ERR(req);
1542                 goto error;
1543         }
1544
1545         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1546
1547         p9_free_req(clnt, req);
1548 error:
1549         if (err == -ERESTARTSYS)
1550                 p9_client_clunk(fid);
1551         else
1552                 p9_fid_destroy(fid);
1553         return err;
1554 }
1555 EXPORT_SYMBOL(p9_client_remove);
1556
1557 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1558 {
1559         int err = 0;
1560         struct p9_req_t *req;
1561         struct p9_client *clnt;
1562
1563         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1564                    dfid->fid, name, flags);
1565
1566         clnt = dfid->clnt;
1567         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1568         if (IS_ERR(req)) {
1569                 err = PTR_ERR(req);
1570                 goto error;
1571         }
1572         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1573
1574         p9_free_req(clnt, req);
1575 error:
1576         return err;
1577 }
1578 EXPORT_SYMBOL(p9_client_unlinkat);
1579
1580 int
1581 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1582 {
1583         struct p9_client *clnt = fid->clnt;
1584         struct p9_req_t *req;
1585         int total = 0;
1586         *err = 0;
1587
1588         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1589                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1590
1591         while (iov_iter_count(to)) {
1592                 int count = iov_iter_count(to);
1593                 int rsize, non_zc = 0;
1594                 char *dataptr;
1595
1596                 rsize = fid->iounit;
1597                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1598                         rsize = clnt->msize - P9_IOHDRSZ;
1599
1600                 if (count < rsize)
1601                         rsize = count;
1602
1603                 /* Don't bother zerocopy for small IO (< 1024) */
1604                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1605                         /*
1606                          * response header len is 11
1607                          * PDU Header(7) + IO Size (4)
1608                          */
1609                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1610                                                0, 11, "dqd", fid->fid,
1611                                                offset, rsize);
1612                 } else {
1613                         non_zc = 1;
1614                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1615                                             rsize);
1616                 }
1617                 if (IS_ERR(req)) {
1618                         *err = PTR_ERR(req);
1619                         break;
1620                 }
1621
1622                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1623                                    "D", &count, &dataptr);
1624                 if (*err) {
1625                         trace_9p_protocol_dump(clnt, req->rc);
1626                         p9_free_req(clnt, req);
1627                         break;
1628                 }
1629                 if (rsize < count) {
1630                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1631                         count = rsize;
1632                 }
1633
1634                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1635                 if (!count) {
1636                         p9_free_req(clnt, req);
1637                         break;
1638                 }
1639
1640                 if (non_zc) {
1641                         int n = copy_to_iter(dataptr, count, to);
1642                         total += n;
1643                         offset += n;
1644                         if (n != count) {
1645                                 *err = -EFAULT;
1646                                 p9_free_req(clnt, req);
1647                                 break;
1648                         }
1649                 } else {
1650                         iov_iter_advance(to, count);
1651                         total += count;
1652                         offset += count;
1653                 }
1654                 p9_free_req(clnt, req);
1655         }
1656         return total;
1657 }
1658 EXPORT_SYMBOL(p9_client_read);
1659
1660 int
1661 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1662 {
1663         struct p9_client *clnt = fid->clnt;
1664         struct p9_req_t *req;
1665         int total = 0;
1666         *err = 0;
1667
1668         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1669                                 fid->fid, (unsigned long long) offset,
1670                                 iov_iter_count(from));
1671
1672         while (iov_iter_count(from)) {
1673                 int count = iov_iter_count(from);
1674                 int rsize = fid->iounit;
1675                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1676                         rsize = clnt->msize - P9_IOHDRSZ;
1677
1678                 if (count < rsize)
1679                         rsize = count;
1680
1681                 /* Don't bother zerocopy for small IO (< 1024) */
1682                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1683                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1684                                                rsize, P9_ZC_HDR_SZ, "dqd",
1685                                                fid->fid, offset, rsize);
1686                 } else {
1687                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1688                                                     offset, rsize, from);
1689                 }
1690                 if (IS_ERR(req)) {
1691                         *err = PTR_ERR(req);
1692                         break;
1693                 }
1694
1695                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1696                 if (*err) {
1697                         trace_9p_protocol_dump(clnt, req->rc);
1698                         p9_free_req(clnt, req);
1699                         break;
1700                 }
1701                 if (rsize < count) {
1702                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1703                         count = rsize;
1704                 }
1705
1706                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1707
1708                 p9_free_req(clnt, req);
1709                 iov_iter_advance(from, count);
1710                 total += count;
1711                 offset += count;
1712         }
1713         return total;
1714 }
1715 EXPORT_SYMBOL(p9_client_write);
1716
1717 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1718 {
1719         int err;
1720         struct p9_client *clnt;
1721         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1722         struct p9_req_t *req;
1723         u16 ignored;
1724
1725         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1726
1727         if (!ret)
1728                 return ERR_PTR(-ENOMEM);
1729
1730         err = 0;
1731         clnt = fid->clnt;
1732
1733         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1734         if (IS_ERR(req)) {
1735                 err = PTR_ERR(req);
1736                 goto error;
1737         }
1738
1739         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1740         if (err) {
1741                 trace_9p_protocol_dump(clnt, req->rc);
1742                 p9_free_req(clnt, req);
1743                 goto error;
1744         }
1745
1746         p9_debug(P9_DEBUG_9P,
1747                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1748                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1749                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1750                 "<<<    uid=%d gid=%d n_muid=%d\n",
1751                 ret->size, ret->type, ret->dev, ret->qid.type,
1752                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1753                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1754                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1755                 from_kuid(&init_user_ns, ret->n_uid),
1756                 from_kgid(&init_user_ns, ret->n_gid),
1757                 from_kuid(&init_user_ns, ret->n_muid));
1758
1759         p9_free_req(clnt, req);
1760         return ret;
1761
1762 error:
1763         kfree(ret);
1764         return ERR_PTR(err);
1765 }
1766 EXPORT_SYMBOL(p9_client_stat);
1767
1768 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1769                                                         u64 request_mask)
1770 {
1771         int err;
1772         struct p9_client *clnt;
1773         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1774                                                                 GFP_KERNEL);
1775         struct p9_req_t *req;
1776
1777         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1778                                                         fid->fid, request_mask);
1779
1780         if (!ret)
1781                 return ERR_PTR(-ENOMEM);
1782
1783         err = 0;
1784         clnt = fid->clnt;
1785
1786         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1787         if (IS_ERR(req)) {
1788                 err = PTR_ERR(req);
1789                 goto error;
1790         }
1791
1792         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1793         if (err) {
1794                 trace_9p_protocol_dump(clnt, req->rc);
1795                 p9_free_req(clnt, req);
1796                 goto error;
1797         }
1798
1799         p9_debug(P9_DEBUG_9P,
1800                 "<<< RGETATTR st_result_mask=%lld\n"
1801                 "<<< qid=%x.%llx.%x\n"
1802                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1803                 "<<< st_uid=%d st_gid=%d\n"
1804                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1805                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1806                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1807                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1808                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1809                 "<<< st_gen=%lld st_data_version=%lld",
1810                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1811                 ret->qid.version, ret->st_mode, ret->st_nlink,
1812                 from_kuid(&init_user_ns, ret->st_uid),
1813                 from_kgid(&init_user_ns, ret->st_gid),
1814                 ret->st_rdev, ret->st_size, ret->st_blksize,
1815                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1816                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1817                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1818                 ret->st_gen, ret->st_data_version);
1819
1820         p9_free_req(clnt, req);
1821         return ret;
1822
1823 error:
1824         kfree(ret);
1825         return ERR_PTR(err);
1826 }
1827 EXPORT_SYMBOL(p9_client_getattr_dotl);
1828
1829 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1830 {
1831         int ret;
1832
1833         /* NOTE: size shouldn't include its own length */
1834         /* size[2] type[2] dev[4] qid[13] */
1835         /* mode[4] atime[4] mtime[4] length[8]*/
1836         /* name[s] uid[s] gid[s] muid[s] */
1837         ret = 2+4+13+4+4+4+8+2+2+2+2;
1838
1839         if (wst->name)
1840                 ret += strlen(wst->name);
1841         if (wst->uid)
1842                 ret += strlen(wst->uid);
1843         if (wst->gid)
1844                 ret += strlen(wst->gid);
1845         if (wst->muid)
1846                 ret += strlen(wst->muid);
1847
1848         if ((proto_version == p9_proto_2000u) ||
1849                 (proto_version == p9_proto_2000L)) {
1850                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1851                 if (wst->extension)
1852                         ret += strlen(wst->extension);
1853         }
1854
1855         return ret;
1856 }
1857
1858 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1859 {
1860         int err;
1861         struct p9_req_t *req;
1862         struct p9_client *clnt;
1863
1864         err = 0;
1865         clnt = fid->clnt;
1866         wst->size = p9_client_statsize(wst, clnt->proto_version);
1867         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1868         p9_debug(P9_DEBUG_9P,
1869                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1870                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1871                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1872                 "     uid=%d gid=%d n_muid=%d\n",
1873                 wst->size, wst->type, wst->dev, wst->qid.type,
1874                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1875                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1876                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1877                 from_kuid(&init_user_ns, wst->n_uid),
1878                 from_kgid(&init_user_ns, wst->n_gid),
1879                 from_kuid(&init_user_ns, wst->n_muid));
1880
1881         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1882         if (IS_ERR(req)) {
1883                 err = PTR_ERR(req);
1884                 goto error;
1885         }
1886
1887         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1888
1889         p9_free_req(clnt, req);
1890 error:
1891         return err;
1892 }
1893 EXPORT_SYMBOL(p9_client_wstat);
1894
1895 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1896 {
1897         int err;
1898         struct p9_req_t *req;
1899         struct p9_client *clnt;
1900
1901         err = 0;
1902         clnt = fid->clnt;
1903         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1904         p9_debug(P9_DEBUG_9P,
1905                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1906                 "    atime_sec=%lld atime_nsec=%lld\n"
1907                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1908                 p9attr->valid, p9attr->mode,
1909                 from_kuid(&init_user_ns, p9attr->uid),
1910                 from_kgid(&init_user_ns, p9attr->gid),
1911                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1912                 p9attr->mtime_sec, p9attr->mtime_nsec);
1913
1914         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1915
1916         if (IS_ERR(req)) {
1917                 err = PTR_ERR(req);
1918                 goto error;
1919         }
1920         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1921         p9_free_req(clnt, req);
1922 error:
1923         return err;
1924 }
1925 EXPORT_SYMBOL(p9_client_setattr);
1926
1927 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1928 {
1929         int err;
1930         struct p9_req_t *req;
1931         struct p9_client *clnt;
1932
1933         err = 0;
1934         clnt = fid->clnt;
1935
1936         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1937
1938         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1939         if (IS_ERR(req)) {
1940                 err = PTR_ERR(req);
1941                 goto error;
1942         }
1943
1944         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1945                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1946                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1947         if (err) {
1948                 trace_9p_protocol_dump(clnt, req->rc);
1949                 p9_free_req(clnt, req);
1950                 goto error;
1951         }
1952
1953         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1954                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1955                 "fsid %llu namelen %ld\n",
1956                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1957                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1958                 sb->fsid, (long int)sb->namelen);
1959
1960         p9_free_req(clnt, req);
1961 error:
1962         return err;
1963 }
1964 EXPORT_SYMBOL(p9_client_statfs);
1965
1966 int p9_client_rename(struct p9_fid *fid,
1967                      struct p9_fid *newdirfid, const char *name)
1968 {
1969         int err;
1970         struct p9_req_t *req;
1971         struct p9_client *clnt;
1972
1973         err = 0;
1974         clnt = fid->clnt;
1975
1976         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1977                         fid->fid, newdirfid->fid, name);
1978
1979         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1980                         newdirfid->fid, name);
1981         if (IS_ERR(req)) {
1982                 err = PTR_ERR(req);
1983                 goto error;
1984         }
1985
1986         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1987
1988         p9_free_req(clnt, req);
1989 error:
1990         return err;
1991 }
1992 EXPORT_SYMBOL(p9_client_rename);
1993
1994 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1995                        struct p9_fid *newdirfid, const char *new_name)
1996 {
1997         int err;
1998         struct p9_req_t *req;
1999         struct p9_client *clnt;
2000
2001         err = 0;
2002         clnt = olddirfid->clnt;
2003
2004         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
2005                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
2006                    newdirfid->fid, new_name);
2007
2008         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
2009                             old_name, newdirfid->fid, new_name);
2010         if (IS_ERR(req)) {
2011                 err = PTR_ERR(req);
2012                 goto error;
2013         }
2014
2015         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
2016                    newdirfid->fid, new_name);
2017
2018         p9_free_req(clnt, req);
2019 error:
2020         return err;
2021 }
2022 EXPORT_SYMBOL(p9_client_renameat);
2023
2024 /*
2025  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2026  */
2027 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2028                                 const char *attr_name, u64 *attr_size)
2029 {
2030         int err;
2031         struct p9_req_t *req;
2032         struct p9_client *clnt;
2033         struct p9_fid *attr_fid;
2034
2035         err = 0;
2036         clnt = file_fid->clnt;
2037         attr_fid = p9_fid_create(clnt);
2038         if (IS_ERR(attr_fid)) {
2039                 err = PTR_ERR(attr_fid);
2040                 attr_fid = NULL;
2041                 goto error;
2042         }
2043         p9_debug(P9_DEBUG_9P,
2044                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2045                 file_fid->fid, attr_fid->fid, attr_name);
2046
2047         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2048                         file_fid->fid, attr_fid->fid, attr_name);
2049         if (IS_ERR(req)) {
2050                 err = PTR_ERR(req);
2051                 goto error;
2052         }
2053         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2054         if (err) {
2055                 trace_9p_protocol_dump(clnt, req->rc);
2056                 p9_free_req(clnt, req);
2057                 goto clunk_fid;
2058         }
2059         p9_free_req(clnt, req);
2060         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2061                 attr_fid->fid, *attr_size);
2062         return attr_fid;
2063 clunk_fid:
2064         p9_client_clunk(attr_fid);
2065         attr_fid = NULL;
2066 error:
2067         if (attr_fid && (attr_fid != file_fid))
2068                 p9_fid_destroy(attr_fid);
2069
2070         return ERR_PTR(err);
2071 }
2072 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2073
2074 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2075                         u64 attr_size, int flags)
2076 {
2077         int err;
2078         struct p9_req_t *req;
2079         struct p9_client *clnt;
2080
2081         p9_debug(P9_DEBUG_9P,
2082                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2083                 fid->fid, name, (long long)attr_size, flags);
2084         err = 0;
2085         clnt = fid->clnt;
2086         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2087                         fid->fid, name, attr_size, flags);
2088         if (IS_ERR(req)) {
2089                 err = PTR_ERR(req);
2090                 goto error;
2091         }
2092         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2093         p9_free_req(clnt, req);
2094 error:
2095         return err;
2096 }
2097 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2098
2099 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2100 {
2101         int err, rsize, non_zc = 0;
2102         struct p9_client *clnt;
2103         struct p9_req_t *req;
2104         char *dataptr;
2105         struct kvec kv = {.iov_base = data, .iov_len = count};
2106         struct iov_iter to;
2107
2108         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2109
2110         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2111                                 fid->fid, (unsigned long long) offset, count);
2112
2113         err = 0;
2114         clnt = fid->clnt;
2115
2116         rsize = fid->iounit;
2117         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2118                 rsize = clnt->msize - P9_READDIRHDRSZ;
2119
2120         if (count < rsize)
2121                 rsize = count;
2122
2123         /* Don't bother zerocopy for small IO (< 1024) */
2124         if (clnt->trans_mod->zc_request && rsize > 1024) {
2125                 /*
2126                  * response header len is 11
2127                  * PDU Header(7) + IO Size (4)
2128                  */
2129                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2130                                        11, "dqd", fid->fid, offset, rsize);
2131         } else {
2132                 non_zc = 1;
2133                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2134                                     offset, rsize);
2135         }
2136         if (IS_ERR(req)) {
2137                 err = PTR_ERR(req);
2138                 goto error;
2139         }
2140
2141         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2142         if (err) {
2143                 trace_9p_protocol_dump(clnt, req->rc);
2144                 goto free_and_error;
2145         }
2146         if (rsize < count) {
2147                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2148                 count = rsize;
2149         }
2150
2151         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2152
2153         if (non_zc)
2154                 memmove(data, dataptr, count);
2155
2156         p9_free_req(clnt, req);
2157         return count;
2158
2159 free_and_error:
2160         p9_free_req(clnt, req);
2161 error:
2162         return err;
2163 }
2164 EXPORT_SYMBOL(p9_client_readdir);
2165
2166 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2167                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2168 {
2169         int err;
2170         struct p9_client *clnt;
2171         struct p9_req_t *req;
2172
2173         err = 0;
2174         clnt = fid->clnt;
2175         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2176                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2177         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2178                 MAJOR(rdev), MINOR(rdev), gid);
2179         if (IS_ERR(req))
2180                 return PTR_ERR(req);
2181
2182         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2183         if (err) {
2184                 trace_9p_protocol_dump(clnt, req->rc);
2185                 goto error;
2186         }
2187         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2188                                 (unsigned long long)qid->path, qid->version);
2189
2190 error:
2191         p9_free_req(clnt, req);
2192         return err;
2193
2194 }
2195 EXPORT_SYMBOL(p9_client_mknod_dotl);
2196
2197 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2198                                 kgid_t gid, struct p9_qid *qid)
2199 {
2200         int err;
2201         struct p9_client *clnt;
2202         struct p9_req_t *req;
2203
2204         err = 0;
2205         clnt = fid->clnt;
2206         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2207                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2208         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2209                 gid);
2210         if (IS_ERR(req))
2211                 return PTR_ERR(req);
2212
2213         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2214         if (err) {
2215                 trace_9p_protocol_dump(clnt, req->rc);
2216                 goto error;
2217         }
2218         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2219                                 (unsigned long long)qid->path, qid->version);
2220
2221 error:
2222         p9_free_req(clnt, req);
2223         return err;
2224
2225 }
2226 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2227
2228 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2229 {
2230         int err;
2231         struct p9_client *clnt;
2232         struct p9_req_t *req;
2233
2234         err = 0;
2235         clnt = fid->clnt;
2236         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2237                         "start %lld length %lld proc_id %d client_id %s\n",
2238                         fid->fid, flock->type, flock->flags, flock->start,
2239                         flock->length, flock->proc_id, flock->client_id);
2240
2241         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2242                                 flock->flags, flock->start, flock->length,
2243                                         flock->proc_id, flock->client_id);
2244
2245         if (IS_ERR(req))
2246                 return PTR_ERR(req);
2247
2248         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2249         if (err) {
2250                 trace_9p_protocol_dump(clnt, req->rc);
2251                 goto error;
2252         }
2253         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2254 error:
2255         p9_free_req(clnt, req);
2256         return err;
2257
2258 }
2259 EXPORT_SYMBOL(p9_client_lock_dotl);
2260
2261 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2262 {
2263         int err;
2264         struct p9_client *clnt;
2265         struct p9_req_t *req;
2266
2267         err = 0;
2268         clnt = fid->clnt;
2269         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2270                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2271                 glock->start, glock->length, glock->proc_id, glock->client_id);
2272
2273         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2274                 glock->start, glock->length, glock->proc_id, glock->client_id);
2275
2276         if (IS_ERR(req))
2277                 return PTR_ERR(req);
2278
2279         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2280                         &glock->start, &glock->length, &glock->proc_id,
2281                         &glock->client_id);
2282         if (err) {
2283                 trace_9p_protocol_dump(clnt, req->rc);
2284                 goto error;
2285         }
2286         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2287                 "proc_id %d client_id %s\n", glock->type, glock->start,
2288                 glock->length, glock->proc_id, glock->client_id);
2289 error:
2290         p9_free_req(clnt, req);
2291         return err;
2292 }
2293 EXPORT_SYMBOL(p9_client_getlock_dotl);
2294
2295 int p9_client_readlink(struct p9_fid *fid, char **target)
2296 {
2297         int err;
2298         struct p9_client *clnt;
2299         struct p9_req_t *req;
2300
2301         err = 0;
2302         clnt = fid->clnt;
2303         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2304
2305         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2306         if (IS_ERR(req))
2307                 return PTR_ERR(req);
2308
2309         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2310         if (err) {
2311                 trace_9p_protocol_dump(clnt, req->rc);
2312                 goto error;
2313         }
2314         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2315 error:
2316         p9_free_req(clnt, req);
2317         return err;
2318 }
2319 EXPORT_SYMBOL(p9_client_readlink);