net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/poll.h>
  32 #include <linux/idr.h>
  33 #include <linux/mutex.h>
  34 #include <linux/slab.h>
  35 #include <linux/sched/signal.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/uio.h>
  38 #include <net/9p/9p.h>
  39 #include <linux/parser.h>
  40 #include <linux/seq_file.h>
  41 #include <net/9p/client.h>
  42 #include <net/9p/transport.h>
  43 #include "protocol.h"
  44
  45 #define CREATE_TRACE_POINTS
  46 #include <trace/events/9p.h>
  47
  48 /*
  49   * Client Option Parsing (code inspired by NFS code)
  50   *  - a little lazy - parse all client options
  51   */
  52
  53 enum {
  54         Opt_msize,
  55         Opt_trans,
  56         Opt_legacy,
  57         Opt_version,
  58         Opt_err,
  59 };
  60
  61 static const match_table_t tokens = {
  62         {Opt_msize, "msize=%u"},
  63         {Opt_legacy, "noextend"},
  64         {Opt_trans, "trans=%s"},
  65         {Opt_version, "version=%s"},
  66         {Opt_err, NULL},
  67 };
  68
  69 inline int p9_is_proto_dotl(struct p9_client *clnt)
  70 {
  71         return clnt->proto_version == p9_proto_2000L;
  72 }
  73 EXPORT_SYMBOL(p9_is_proto_dotl);
  74
  75 inline int p9_is_proto_dotu(struct p9_client *clnt)
  76 {
  77         return clnt->proto_version == p9_proto_2000u;
  78 }
  79 EXPORT_SYMBOL(p9_is_proto_dotu);
  80
  81 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
  82 {
  83         if (clnt->msize != 8192)
  84                 seq_printf(m, ",msize=%u", clnt->msize);
  85         seq_printf(m, ",trans=%s", clnt->trans_mod->name);
  86
  87         switch (clnt->proto_version) {
  88         case p9_proto_legacy:
  89                 seq_puts(m, ",noextend");
  90                 break;
  91         case p9_proto_2000u:
  92                 seq_puts(m, ",version=9p2000.u");
  93                 break;
  94         case p9_proto_2000L:
  95                 /* Default */
  96                 break;
  97         }
  98
  99         if (clnt->trans_mod->show_options)
 100                 return clnt->trans_mod->show_options(m, clnt);
 101         return 0;
 102 }
 103 EXPORT_SYMBOL(p9_show_client_options);
 104
 105 /*
 106  * Some error codes are taken directly from the server replies,
 107  * make sure they are valid.
 108  */
 109 static int safe_errno(int err)
 110 {
 111         if ((err > 0) || (err < -MAX_ERRNO)) {
 112                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
 113                 return -EPROTO;
 114         }
 115         return err;
 116 }
 117
 118
 119 /* Interpret mount option for protocol version */
 120 static int get_protocol_version(char *s)
 121 {
 122         int version = -EINVAL;
 123
 124         if (!strcmp(s, "9p2000")) {
 125                 version = p9_proto_legacy;
 126                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
 127         } else if (!strcmp(s, "9p2000.u")) {
 128                 version = p9_proto_2000u;
 129                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
 130         } else if (!strcmp(s, "9p2000.L")) {
 131                 version = p9_proto_2000L;
 132                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
 133         } else
 134                 pr_info("Unknown protocol version %s\n", s);
 135
 136         return version;
 137 }
 138
 139 /**
 140  * parse_options - parse mount options into client structure
 141  * @opts: options string passed from mount
 142  * @clnt: existing v9fs client information
 143  *
 144  * Return 0 upon success, -ERRNO upon failure
 145  */
 146
 147 static int parse_opts(char *opts, struct p9_client *clnt)
 148 {
 149         char *options, *tmp_options;
 150         char *p;
 151         substring_t args[MAX_OPT_ARGS];
 152         int option;
 153         char *s;
 154         int ret = 0;
 155
 156         clnt->proto_version = p9_proto_2000L;
 157         clnt->msize = 8192;
 158
 159         if (!opts)
 160                 return 0;
 161
 162         tmp_options = kstrdup(opts, GFP_KERNEL);
 163         if (!tmp_options) {
 164                 p9_debug(P9_DEBUG_ERROR,
 165                          "failed to allocate copy of option string\n");
 166                 return -ENOMEM;
 167         }
 168         options = tmp_options;
 169
 170         while ((p = strsep(&options, ",")) != NULL) {
 171                 int token, r;
 172                 if (!*p)
 173                         continue;
 174                 token = match_token(p, tokens, args);
 175                 switch (token) {
 176                 case Opt_msize:
 177                         r = match_int(&args[0], &option);
 178                         if (r < 0) {
 179                                 p9_debug(P9_DEBUG_ERROR,
 180                                          "integer field, but no integer?\n");
 181                                 ret = r;
 182                                 continue;
 183                         }
 184                         clnt->msize = option;
 185                         break;
 186                 case Opt_trans:
 187                         s = match_strdup(&args[0]);
 188                         if (!s) {
 189                                 ret = -ENOMEM;
 190                                 p9_debug(P9_DEBUG_ERROR,
 191                                          "problem allocating copy of trans arg\n");
 192                                 goto free_and_return;
 193                         }
 194
 195                         v9fs_put_trans(clnt->trans_mod);
 196                         clnt->trans_mod = v9fs_get_trans_by_name(s);
 197                         if (clnt->trans_mod == NULL) {
 198                                 pr_info("Could not find request transport: %s\n",
 199                                         s);
 200                                 ret = -EINVAL;
 201                                 kfree(s);
 202                                 goto free_and_return;
 203                         }
 204                         kfree(s);
 205                         break;
 206                 case Opt_legacy:
 207                         clnt->proto_version = p9_proto_legacy;
 208                         break;
 209                 case Opt_version:
 210                         s = match_strdup(&args[0]);
 211                         if (!s) {
 212                                 ret = -ENOMEM;
 213                                 p9_debug(P9_DEBUG_ERROR,
 214                                          "problem allocating copy of version arg\n");
 215                                 goto free_and_return;
 216                         }
 217                         ret = get_protocol_version(s);
 218                         if (ret == -EINVAL) {
 219                                 kfree(s);
 220                                 goto free_and_return;
 221                         }
 222                         kfree(s);
 223                         clnt->proto_version = ret;
 224                         break;
 225                 default:
 226                         continue;
 227                 }
 228         }
 229
 230 free_and_return:
 231         v9fs_put_trans(clnt->trans_mod);
 232         kfree(tmp_options);
 233         return ret;
 234 }
 235
 236 static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
 237 {
 238         struct p9_fcall *fc;
 239         fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
 240         if (!fc)
 241                 return NULL;
 242         fc->capacity = alloc_msize;
 243         fc->sdata = (char *) fc + sizeof(struct p9_fcall);
 244         return fc;
 245 }
 246
 247 /**
 248  * p9_tag_alloc - lookup/allocate a request by tag
 249  * @c: client session to lookup tag within
 250  * @tag: numeric id for transaction
 251  *
 252  * this is a simple array lookup, but will grow the
 253  * request_slots as necessary to accommodate transaction
 254  * ids which did not previously have a slot.
 255  *
 256  * this code relies on the client spinlock to manage locks, its
 257  * possible we should switch to something else, but I'd rather
 258  * stick with something low-overhead for the common case.
 259  *
 260  */
 261
 262 static struct p9_req_t *
 263 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
 264 {
 265         unsigned long flags;
 266         int row, col;
 267         struct p9_req_t *req;
 268         int alloc_msize = min(c->msize, max_size);
 269
 270         /* This looks up the original request by tag so we know which
 271          * buffer to read the data into */
 272         tag++;
 273
 274         if (tag >= c->max_tag) {
 275                 spin_lock_irqsave(&c->lock, flags);
 276                 /* check again since original check was outside of lock */
 277                 while (tag >= c->max_tag) {
 278                         row = (tag / P9_ROW_MAXTAG);
 279                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 280                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 281
 282                         if (!c->reqs[row]) {
 283                                 pr_err("Couldn't grow tag array\n");
 284                                 spin_unlock_irqrestore(&c->lock, flags);
 285                                 return ERR_PTR(-ENOMEM);
 286                         }
 287                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 288                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 289                                 c->reqs[row][col].tc = NULL;
 290                         }
 291                         c->max_tag += P9_ROW_MAXTAG;
 292                 }
 293                 spin_unlock_irqrestore(&c->lock, flags);
 294         }
 295         row = tag / P9_ROW_MAXTAG;
 296         col = tag % P9_ROW_MAXTAG;
 297
 298         req = &c->reqs[row][col];
 299         if (!req->wq) {
 300                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
 301                 if (!req->wq)
 302                         goto grow_failed;
 303                 init_waitqueue_head(req->wq);
 304         }
 305
 306         if (!req->tc)
 307                 req->tc = p9_fcall_alloc(alloc_msize);
 308         if (!req->rc)
 309                 req->rc = p9_fcall_alloc(alloc_msize);
 310         if (!req->tc || !req->rc)
 311                 goto grow_failed;
 312
 313         p9pdu_reset(req->tc);
 314         p9pdu_reset(req->rc);
 315
 316         req->tc->tag = tag-1;
 317         req->status = REQ_STATUS_ALLOC;
 318
 319         return req;
 320
 321 grow_failed:
 322         pr_err("Couldn't grow tag array\n");
 323         kfree(req->tc);
 324         kfree(req->rc);
 325         kfree(req->wq);
 326         req->tc = req->rc = NULL;
 327         req->wq = NULL;
 328         return ERR_PTR(-ENOMEM);
 329 }
 330
 331 /**
 332  * p9_tag_lookup - lookup a request by tag
 333  * @c: client session to lookup tag within
 334  * @tag: numeric id for transaction
 335  *
 336  */
 337
 338 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 339 {
 340         int row, col;
 341
 342         /* This looks up the original request by tag so we know which
 343          * buffer to read the data into */
 344         tag++;
 345
 346         if(tag >= c->max_tag)
 347                 return NULL;
 348
 349         row = tag / P9_ROW_MAXTAG;
 350         col = tag % P9_ROW_MAXTAG;
 351
 352         return &c->reqs[row][col];
 353 }
 354 EXPORT_SYMBOL(p9_tag_lookup);
 355
 356 /**
 357  * p9_tag_init - setup tags structure and contents
 358  * @c:  v9fs client struct
 359  *
 360  * This initializes the tags structure for each client instance.
 361  *
 362  */
 363
 364 static int p9_tag_init(struct p9_client *c)
 365 {
 366         int err = 0;
 367
 368         c->tagpool = p9_idpool_create();
 369         if (IS_ERR(c->tagpool)) {
 370                 err = PTR_ERR(c->tagpool);
 371                 goto error;
 372         }
 373         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
 374         if (err < 0) {
 375                 p9_idpool_destroy(c->tagpool);
 376                 goto error;
 377         }
 378         c->max_tag = 0;
 379 error:
 380         return err;
 381 }
 382
 383 /**
 384  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 385  * @c:  v9fs client struct
 386  *
 387  * This frees resources associated with the tags structure
 388  *
 389  */
 390 static void p9_tag_cleanup(struct p9_client *c)
 391 {
 392         int row, col;
 393
 394         /* check to insure all requests are idle */
 395         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 396                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 397                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 398                                 p9_debug(P9_DEBUG_MUX,
 399                                          "Attempting to cleanup non-free tag %d,%d\n",
 400                                          row, col);
 401                                 /* TODO: delay execution of cleanup */
 402                                 return;
 403                         }
 404                 }
 405         }
 406
 407         if (c->tagpool) {
 408                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
 409                 p9_idpool_destroy(c->tagpool);
 410         }
 411
 412         /* free requests associated with tags */
 413         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 414                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 415                         kfree(c->reqs[row][col].wq);
 416                         kfree(c->reqs[row][col].tc);
 417                         kfree(c->reqs[row][col].rc);
 418                 }
 419                 kfree(c->reqs[row]);
 420         }
 421         c->max_tag = 0;
 422 }
 423
 424 /**
 425  * p9_free_req - free a request and clean-up as necessary
 426  * c: client state
 427  * r: request to release
 428  *
 429  */
 430
 431 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 432 {
 433         int tag = r->tc->tag;
 434         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 435
 436         r->status = REQ_STATUS_IDLE;
 437         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 438                 p9_idpool_put(tag, c->tagpool);
 439 }
 440
 441 /**
 442  * p9_client_cb - call back from transport to client
 443  * c: client state
 444  * req: request received
 445  *
 446  */
 447 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 448 {
 449         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 450
 451         /*
 452          * This barrier is needed to make sure any change made to req before
 453          * the other thread wakes up will indeed be seen by the waiting side.
 454          */
 455         smp_wmb();
 456         req->status = status;
 457
 458         wake_up(req->wq);
 459         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 460 }
 461 EXPORT_SYMBOL(p9_client_cb);
 462
 463 /**
 464  * p9_parse_header - parse header arguments out of a packet
 465  * @pdu: packet to parse
 466  * @size: size of packet
 467  * @type: type of request
 468  * @tag: tag of packet
 469  * @rewind: set if we need to rewind offset afterwards
 470  */
 471
 472 int
 473 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 474                                                                 int rewind)
 475 {
 476         int8_t r_type;
 477         int16_t r_tag;
 478         int32_t r_size;
 479         int offset = pdu->offset;
 480         int err;
 481
 482         pdu->offset = 0;
 483         if (pdu->size == 0)
 484                 pdu->size = 7;
 485
 486         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 487         if (err)
 488                 goto rewind_and_exit;
 489
 490         pdu->size = r_size;
 491         pdu->id = r_type;
 492         pdu->tag = r_tag;
 493
 494         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 495                  pdu->size, pdu->id, pdu->tag);
 496
 497         if (type)
 498                 *type = r_type;
 499         if (tag)
 500                 *tag = r_tag;
 501         if (size)
 502                 *size = r_size;
 503
 504
 505 rewind_and_exit:
 506         if (rewind)
 507                 pdu->offset = offset;
 508         return err;
 509 }
 510 EXPORT_SYMBOL(p9_parse_header);
 511
 512 /**
 513  * p9_check_errors - check 9p packet for error return and process it
 514  * @c: current client instance
 515  * @req: request to parse and check for error conditions
 516  *
 517  * returns error code if one is discovered, otherwise returns 0
 518  *
 519  * this will have to be more complicated if we have multiple
 520  * error packet types
 521  */
 522
 523 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 524 {
 525         int8_t type;
 526         int err;
 527         int ecode;
 528
 529         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 530         /*
 531          * dump the response from server
 532          * This should be after check errors which poplulate pdu_fcall.
 533          */
 534         trace_9p_protocol_dump(c, req->rc);
 535         if (err) {
 536                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 537                 return err;
 538         }
 539         if (type != P9_RERROR && type != P9_RLERROR)
 540                 return 0;
 541
 542         if (!p9_is_proto_dotl(c)) {
 543                 char *ename;
 544                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 545                                   &ename, &ecode);
 546                 if (err)
 547                         goto out_err;
 548
 549                 if (p9_is_proto_dotu(c) && ecode < 512)
 550                         err = -ecode;
 551
 552                 if (!err) {
 553                         err = p9_errstr2errno(ename, strlen(ename));
 554
 555                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 556                                  -ecode, ename);
 557                 }
 558                 kfree(ename);
 559         } else {
 560                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 561                 err = -ecode;
 562
 563                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 564         }
 565
 566         return err;
 567
 568 out_err:
 569         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 570
 571         return err;
 572 }
 573
 574 /**
 575  * p9_check_zc_errors - check 9p packet for error return and process it
 576  * @c: current client instance
 577  * @req: request to parse and check for error conditions
 578  * @in_hdrlen: Size of response protocol buffer.
 579  *
 580  * returns error code if one is discovered, otherwise returns 0
 581  *
 582  * this will have to be more complicated if we have multiple
 583  * error packet types
 584  */
 585
 586 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 587                               struct iov_iter *uidata, int in_hdrlen)
 588 {
 589         int err;
 590         int ecode;
 591         int8_t type;
 592         char *ename = NULL;
 593
 594         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 595         /*
 596          * dump the response from server
 597          * This should be after parse_header which poplulate pdu_fcall.
 598          */
 599         trace_9p_protocol_dump(c, req->rc);
 600         if (err) {
 601                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 602                 return err;
 603         }
 604
 605         if (type != P9_RERROR && type != P9_RLERROR)
 606                 return 0;
 607
 608         if (!p9_is_proto_dotl(c)) {
 609                 /* Error is reported in string format */
 610                 int len;
 611                 /* 7 = header size for RERROR; */
 612                 int inline_len = in_hdrlen - 7;
 613
 614                 len =  req->rc->size - req->rc->offset;
 615                 if (len > (P9_ZC_HDR_SZ - 7)) {
 616                         err = -EFAULT;
 617                         goto out_err;
 618                 }
 619
 620                 ename = &req->rc->sdata[req->rc->offset];
 621                 if (len > inline_len) {
 622                         /* We have error in external buffer */
 623                         if (!copy_from_iter_full(ename + inline_len,
 624                                              len - inline_len, uidata)) {
 625                                 err = -EFAULT;
 626                                 goto out_err;
 627                         }
 628                 }
 629                 ename = NULL;
 630                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 631                                   &ename, &ecode);
 632                 if (err)
 633                         goto out_err;
 634
 635                 if (p9_is_proto_dotu(c) && ecode < 512)
 636                         err = -ecode;
 637
 638                 if (!err) {
 639                         err = p9_errstr2errno(ename, strlen(ename));
 640
 641                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 642                                  -ecode, ename);
 643                 }
 644                 kfree(ename);
 645         } else {
 646                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 647                 err = -ecode;
 648
 649                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 650         }
 651         return err;
 652
 653 out_err:
 654         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 655         return err;
 656 }
 657
 658 static struct p9_req_t *
 659 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 660
 661 /**
 662  * p9_client_flush - flush (cancel) a request
 663  * @c: client state
 664  * @oldreq: request to cancel
 665  *
 666  * This sents a flush for a particular request and links
 667  * the flush request to the original request.  The current
 668  * code only supports a single flush request although the protocol
 669  * allows for multiple flush requests to be sent for a single request.
 670  *
 671  */
 672
 673 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 674 {
 675         struct p9_req_t *req;
 676         int16_t oldtag;
 677         int err;
 678
 679         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 680         if (err)
 681                 return err;
 682
 683         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 684
 685         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 686         if (IS_ERR(req))
 687                 return PTR_ERR(req);
 688
 689         /*
 690          * if we haven't received a response for oldreq,
 691          * remove it from the list
 692          */
 693         if (oldreq->status == REQ_STATUS_SENT)
 694                 if (c->trans_mod->cancelled)
 695                         c->trans_mod->cancelled(c, oldreq);
 696
 697         p9_free_req(c, req);
 698         return 0;
 699 }
 700
 701 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 702                                               int8_t type, int req_size,
 703                                               const char *fmt, va_list ap)
 704 {
 705         int tag, err;
 706         struct p9_req_t *req;
 707
 708         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 709
 710         /* we allow for any status other than disconnected */
 711         if (c->status == Disconnected)
 712                 return ERR_PTR(-EIO);
 713
 714         /* if status is begin_disconnected we allow only clunk request */
 715         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 716                 return ERR_PTR(-EIO);
 717
 718         tag = P9_NOTAG;
 719         if (type != P9_TVERSION) {
 720                 tag = p9_idpool_get(c->tagpool);
 721                 if (tag < 0)
 722                         return ERR_PTR(-ENOMEM);
 723         }
 724
 725         req = p9_tag_alloc(c, tag, req_size);
 726         if (IS_ERR(req))
 727                 return req;
 728
 729         /* marshall the data */
 730         p9pdu_prepare(req->tc, tag, type);
 731         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 732         if (err)
 733                 goto reterr;
 734         p9pdu_finalize(c, req->tc);
 735         trace_9p_client_req(c, type, tag);
 736         return req;
 737 reterr:
 738         p9_free_req(c, req);
 739         return ERR_PTR(err);
 740 }
 741
 742 /**
 743  * p9_client_rpc - issue a request and wait for a response
 744  * @c: client session
 745  * @type: type of request
 746  * @fmt: protocol format string (see protocol.c)
 747  *
 748  * Returns request structure (which client must free using p9_free_req)
 749  */
 750
 751 static struct p9_req_t *
 752 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 753 {
 754         va_list ap;
 755         int sigpending, err;
 756         unsigned long flags;
 757         struct p9_req_t *req;
 758
 759         va_start(ap, fmt);
 760         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 761         va_end(ap);
 762         if (IS_ERR(req))
 763                 return req;
 764
 765         if (signal_pending(current)) {
 766                 sigpending = 1;
 767                 clear_thread_flag(TIF_SIGPENDING);
 768         } else
 769                 sigpending = 0;
 770
 771         err = c->trans_mod->request(c, req);
 772         if (err < 0) {
 773                 if (err != -ERESTARTSYS && err != -EFAULT)
 774                         c->status = Disconnected;
 775                 goto recalc_sigpending;
 776         }
 777 again:
 778         /* Wait for the response */
 779         err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD);
 780
 781         /*
 782          * Make sure our req is coherent with regard to updates in other
 783          * threads - echoes to wmb() in the callback
 784          */
 785         smp_rmb();
 786
 787         if ((err == -ERESTARTSYS) && (c->status == Connected)
 788                                   && (type == P9_TFLUSH)) {
 789                 sigpending = 1;
 790                 clear_thread_flag(TIF_SIGPENDING);
 791                 goto again;
 792         }
 793
 794         if (req->status == REQ_STATUS_ERROR) {
 795                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 796                 err = req->t_err;
 797         }
 798         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 799                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 800                 sigpending = 1;
 801                 clear_thread_flag(TIF_SIGPENDING);
 802
 803                 if (c->trans_mod->cancel(c, req))
 804                         p9_client_flush(c, req);
 805
 806                 /* if we received the response anyway, don't signal error */
 807                 if (req->status == REQ_STATUS_RCVD)
 808                         err = 0;
 809         }
 810 recalc_sigpending:
 811         if (sigpending) {
 812                 spin_lock_irqsave(&current->sighand->siglock, flags);
 813                 recalc_sigpending();
 814                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 815         }
 816         if (err < 0)
 817                 goto reterr;
 818
 819         err = p9_check_errors(c, req);
 820         trace_9p_client_res(c, type, req->rc->tag, err);
 821         if (!err)
 822                 return req;
 823 reterr:
 824         p9_free_req(c, req);
 825         return ERR_PTR(safe_errno(err));
 826 }
 827
 828 /**
 829  * p9_client_zc_rpc - issue a request and wait for a response
 830  * @c: client session
 831  * @type: type of request
 832  * @uidata: destination for zero copy read
 833  * @uodata: source for zero copy write
 834  * @inlen: read buffer size
 835  * @olen: write buffer size
 836  * @hdrlen: reader header size, This is the size of response protocol data
 837  * @fmt: protocol format string (see protocol.c)
 838  *
 839  * Returns request structure (which client must free using p9_free_req)
 840  */
 841 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 842                                          struct iov_iter *uidata,
 843                                          struct iov_iter *uodata,
 844                                          int inlen, int olen, int in_hdrlen,
 845                                          const char *fmt, ...)
 846 {
 847         va_list ap;
 848         int sigpending, err;
 849         unsigned long flags;
 850         struct p9_req_t *req;
 851
 852         va_start(ap, fmt);
 853         /*
 854          * We allocate a inline protocol data of only 4k bytes.
 855          * The actual content is passed in zero-copy fashion.
 856          */
 857         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 858         va_end(ap);
 859         if (IS_ERR(req))
 860                 return req;
 861
 862         if (signal_pending(current)) {
 863                 sigpending = 1;
 864                 clear_thread_flag(TIF_SIGPENDING);
 865         } else
 866                 sigpending = 0;
 867
 868         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 869                                        inlen, olen, in_hdrlen);
 870         if (err < 0) {
 871                 if (err == -EIO)
 872                         c->status = Disconnected;
 873                 if (err != -ERESTARTSYS)
 874                         goto recalc_sigpending;
 875         }
 876         if (req->status == REQ_STATUS_ERROR) {
 877                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 878                 err = req->t_err;
 879         }
 880         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 881                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 882                 sigpending = 1;
 883                 clear_thread_flag(TIF_SIGPENDING);
 884
 885                 if (c->trans_mod->cancel(c, req))
 886                         p9_client_flush(c, req);
 887
 888                 /* if we received the response anyway, don't signal error */
 889                 if (req->status == REQ_STATUS_RCVD)
 890                         err = 0;
 891         }
 892 recalc_sigpending:
 893         if (sigpending) {
 894                 spin_lock_irqsave(&current->sighand->siglock, flags);
 895                 recalc_sigpending();
 896                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 897         }
 898         if (err < 0)
 899                 goto reterr;
 900
 901         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 902         trace_9p_client_res(c, type, req->rc->tag, err);
 903         if (!err)
 904                 return req;
 905 reterr:
 906         p9_free_req(c, req);
 907         return ERR_PTR(safe_errno(err));
 908 }
 909
 910 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 911 {
 912         int ret;
 913         struct p9_fid *fid;
 914         unsigned long flags;
 915
 916         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 917         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 918         if (!fid)
 919                 return ERR_PTR(-ENOMEM);
 920
 921         ret = p9_idpool_get(clnt->fidpool);
 922         if (ret < 0) {
 923                 ret = -ENOSPC;
 924                 goto error;
 925         }
 926         fid->fid = ret;
 927
 928         memset(&fid->qid, 0, sizeof(struct p9_qid));
 929         fid->mode = -1;
 930         fid->uid = current_fsuid();
 931         fid->clnt = clnt;
 932         fid->rdir = NULL;
 933         spin_lock_irqsave(&clnt->lock, flags);
 934         list_add(&fid->flist, &clnt->fidlist);
 935         spin_unlock_irqrestore(&clnt->lock, flags);
 936
 937         return fid;
 938
 939 error:
 940         kfree(fid);
 941         return ERR_PTR(ret);
 942 }
 943
 944 static void p9_fid_destroy(struct p9_fid *fid)
 945 {
 946         struct p9_client *clnt;
 947         unsigned long flags;
 948
 949         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 950         clnt = fid->clnt;
 951         p9_idpool_put(fid->fid, clnt->fidpool);
 952         spin_lock_irqsave(&clnt->lock, flags);
 953         list_del(&fid->flist);
 954         spin_unlock_irqrestore(&clnt->lock, flags);
 955         kfree(fid->rdir);
 956         kfree(fid);
 957 }
 958
 959 static int p9_client_version(struct p9_client *c)
 960 {
 961         int err = 0;
 962         struct p9_req_t *req;
 963         char *version;
 964         int msize;
 965
 966         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 967                  c->msize, c->proto_version);
 968
 969         switch (c->proto_version) {
 970         case p9_proto_2000L:
 971                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 972                                         c->msize, "9P2000.L");
 973                 break;
 974         case p9_proto_2000u:
 975                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 976                                         c->msize, "9P2000.u");
 977                 break;
 978         case p9_proto_legacy:
 979                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 980                                         c->msize, "9P2000");
 981                 break;
 982         default:
 983                 return -EINVAL;
 984         }
 985
 986         if (IS_ERR(req))
 987                 return PTR_ERR(req);
 988
 989         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 990         if (err) {
 991                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 992                 trace_9p_protocol_dump(c, req->rc);
 993                 goto error;
 994         }
 995
 996         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 997         if (!strncmp(version, "9P2000.L", 8))
 998                 c->proto_version = p9_proto_2000L;
 999         else if (!strncmp(version, "9P2000.u", 8))
1000                 c->proto_version = p9_proto_2000u;
1001         else if (!strncmp(version, "9P2000", 6))
1002                 c->proto_version = p9_proto_legacy;
1003         else {
1004                 err = -EREMOTEIO;
1005                 goto error;
1006         }
1007
1008         if (msize < c->msize)
1009                 c->msize = msize;
1010
1011 error:
1012         kfree(version);
1013         p9_free_req(c, req);
1014
1015         return err;
1016 }
1017
1018 struct p9_client *p9_client_create(const char *dev_name, char *options)
1019 {
1020         int err;
1021         struct p9_client *clnt;
1022         char *client_id;
1023
1024         err = 0;
1025         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1026         if (!clnt)
1027                 return ERR_PTR(-ENOMEM);
1028
1029         clnt->trans_mod = NULL;
1030         clnt->trans = NULL;
1031
1032         client_id = utsname()->nodename;
1033         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1034
1035         spin_lock_init(&clnt->lock);
1036         INIT_LIST_HEAD(&clnt->fidlist);
1037
1038         err = p9_tag_init(clnt);
1039         if (err < 0)
1040                 goto free_client;
1041
1042         err = parse_opts(options, clnt);
1043         if (err < 0)
1044                 goto destroy_tagpool;
1045
1046         if (!clnt->trans_mod)
1047                 clnt->trans_mod = v9fs_get_default_trans();
1048
1049         if (clnt->trans_mod == NULL) {
1050                 err = -EPROTONOSUPPORT;
1051                 p9_debug(P9_DEBUG_ERROR,
1052                          "No transport defined or default transport\n");
1053                 goto destroy_tagpool;
1054         }
1055
1056         clnt->fidpool = p9_idpool_create();
1057         if (IS_ERR(clnt->fidpool)) {
1058                 err = PTR_ERR(clnt->fidpool);
1059                 goto put_trans;
1060         }
1061
1062         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1063                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1064
1065         err = clnt->trans_mod->create(clnt, dev_name, options);
1066         if (err)
1067                 goto destroy_fidpool;
1068
1069         if (clnt->msize > clnt->trans_mod->maxsize)
1070                 clnt->msize = clnt->trans_mod->maxsize;
1071
1072         err = p9_client_version(clnt);
1073         if (err)
1074                 goto close_trans;
1075
1076         return clnt;
1077
1078 close_trans:
1079         clnt->trans_mod->close(clnt);
1080 destroy_fidpool:
1081         p9_idpool_destroy(clnt->fidpool);
1082 put_trans:
1083         v9fs_put_trans(clnt->trans_mod);
1084 destroy_tagpool:
1085         p9_idpool_destroy(clnt->tagpool);
1086 free_client:
1087         kfree(clnt);
1088         return ERR_PTR(err);
1089 }
1090 EXPORT_SYMBOL(p9_client_create);
1091
1092 void p9_client_destroy(struct p9_client *clnt)
1093 {
1094         struct p9_fid *fid, *fidptr;
1095
1096         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1097
1098         if (clnt->trans_mod)
1099                 clnt->trans_mod->close(clnt);
1100
1101         v9fs_put_trans(clnt->trans_mod);
1102
1103         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1104                 pr_info("Found fid %d not clunked\n", fid->fid);
1105                 p9_fid_destroy(fid);
1106         }
1107
1108         if (clnt->fidpool)
1109                 p9_idpool_destroy(clnt->fidpool);
1110
1111         p9_tag_cleanup(clnt);
1112
1113         kfree(clnt);
1114 }
1115 EXPORT_SYMBOL(p9_client_destroy);
1116
1117 void p9_client_disconnect(struct p9_client *clnt)
1118 {
1119         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1120         clnt->status = Disconnected;
1121 }
1122 EXPORT_SYMBOL(p9_client_disconnect);
1123
1124 void p9_client_begin_disconnect(struct p9_client *clnt)
1125 {
1126         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1127         clnt->status = BeginDisconnect;
1128 }
1129 EXPORT_SYMBOL(p9_client_begin_disconnect);
1130
1131 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1132         const char *uname, kuid_t n_uname, const char *aname)
1133 {
1134         int err = 0;
1135         struct p9_req_t *req;
1136         struct p9_fid *fid;
1137         struct p9_qid qid;
1138
1139
1140         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1141                  afid ? afid->fid : -1, uname, aname);
1142         fid = p9_fid_create(clnt);
1143         if (IS_ERR(fid)) {
1144                 err = PTR_ERR(fid);
1145                 fid = NULL;
1146                 goto error;
1147         }
1148         fid->uid = n_uname;
1149
1150         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1151                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1152         if (IS_ERR(req)) {
1153                 err = PTR_ERR(req);
1154                 goto error;
1155         }
1156
1157         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1158         if (err) {
1159                 trace_9p_protocol_dump(clnt, req->rc);
1160                 p9_free_req(clnt, req);
1161                 goto error;
1162         }
1163
1164         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1165                  qid.type, (unsigned long long)qid.path, qid.version);
1166
1167         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1168
1169         p9_free_req(clnt, req);
1170         return fid;
1171
1172 error:
1173         if (fid)
1174                 p9_fid_destroy(fid);
1175         return ERR_PTR(err);
1176 }
1177 EXPORT_SYMBOL(p9_client_attach);
1178
1179 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1180                 const unsigned char * const *wnames, int clone)
1181 {
1182         int err;
1183         struct p9_client *clnt;
1184         struct p9_fid *fid;
1185         struct p9_qid *wqids;
1186         struct p9_req_t *req;
1187         uint16_t nwqids, count;
1188
1189         err = 0;
1190         wqids = NULL;
1191         clnt = oldfid->clnt;
1192         if (clone) {
1193                 fid = p9_fid_create(clnt);
1194                 if (IS_ERR(fid)) {
1195                         err = PTR_ERR(fid);
1196                         fid = NULL;
1197                         goto error;
1198                 }
1199
1200                 fid->uid = oldfid->uid;
1201         } else
1202                 fid = oldfid;
1203
1204
1205         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1206                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1207
1208         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1209                                                                 nwname, wnames);
1210         if (IS_ERR(req)) {
1211                 err = PTR_ERR(req);
1212                 goto error;
1213         }
1214
1215         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1216         if (err) {
1217                 trace_9p_protocol_dump(clnt, req->rc);
1218                 p9_free_req(clnt, req);
1219                 goto clunk_fid;
1220         }
1221         p9_free_req(clnt, req);
1222
1223         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1224
1225         if (nwqids != nwname) {
1226                 err = -ENOENT;
1227                 goto clunk_fid;
1228         }
1229
1230         for (count = 0; count < nwqids; count++)
1231                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1232                         count, wqids[count].type,
1233                         (unsigned long long)wqids[count].path,
1234                         wqids[count].version);
1235
1236         if (nwname)
1237                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1238         else
1239                 fid->qid = oldfid->qid;
1240
1241         kfree(wqids);
1242         return fid;
1243
1244 clunk_fid:
1245         kfree(wqids);
1246         p9_client_clunk(fid);
1247         fid = NULL;
1248
1249 error:
1250         if (fid && (fid != oldfid))
1251                 p9_fid_destroy(fid);
1252
1253         return ERR_PTR(err);
1254 }
1255 EXPORT_SYMBOL(p9_client_walk);
1256
1257 int p9_client_open(struct p9_fid *fid, int mode)
1258 {
1259         int err;
1260         struct p9_client *clnt;
1261         struct p9_req_t *req;
1262         struct p9_qid qid;
1263         int iounit;
1264
1265         clnt = fid->clnt;
1266         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1267                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1268         err = 0;
1269
1270         if (fid->mode != -1)
1271                 return -EINVAL;
1272
1273         if (p9_is_proto_dotl(clnt))
1274                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1275         else
1276                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1277         if (IS_ERR(req)) {
1278                 err = PTR_ERR(req);
1279                 goto error;
1280         }
1281
1282         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1283         if (err) {
1284                 trace_9p_protocol_dump(clnt, req->rc);
1285                 goto free_and_error;
1286         }
1287
1288         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1289                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1290                 (unsigned long long)qid.path, qid.version, iounit);
1291
1292         fid->mode = mode;
1293         fid->iounit = iounit;
1294
1295 free_and_error:
1296         p9_free_req(clnt, req);
1297 error:
1298         return err;
1299 }
1300 EXPORT_SYMBOL(p9_client_open);
1301
1302 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1303                 kgid_t gid, struct p9_qid *qid)
1304 {
1305         int err = 0;
1306         struct p9_client *clnt;
1307         struct p9_req_t *req;
1308         int iounit;
1309
1310         p9_debug(P9_DEBUG_9P,
1311                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1312                         ofid->fid, name, flags, mode,
1313                         from_kgid(&init_user_ns, gid));
1314         clnt = ofid->clnt;
1315
1316         if (ofid->mode != -1)
1317                 return -EINVAL;
1318
1319         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1320                         mode, gid);
1321         if (IS_ERR(req)) {
1322                 err = PTR_ERR(req);
1323                 goto error;
1324         }
1325
1326         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1327         if (err) {
1328                 trace_9p_protocol_dump(clnt, req->rc);
1329                 goto free_and_error;
1330         }
1331
1332         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1333                         qid->type,
1334                         (unsigned long long)qid->path,
1335                         qid->version, iounit);
1336
1337         ofid->mode = mode;
1338         ofid->iounit = iounit;
1339
1340 free_and_error:
1341         p9_free_req(clnt, req);
1342 error:
1343         return err;
1344 }
1345 EXPORT_SYMBOL(p9_client_create_dotl);
1346
1347 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1348                      char *extension)
1349 {
1350         int err;
1351         struct p9_client *clnt;
1352         struct p9_req_t *req;
1353         struct p9_qid qid;
1354         int iounit;
1355
1356         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1357                                                 fid->fid, name, perm, mode);
1358         err = 0;
1359         clnt = fid->clnt;
1360
1361         if (fid->mode != -1)
1362                 return -EINVAL;
1363
1364         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1365                                 mode, extension);
1366         if (IS_ERR(req)) {
1367                 err = PTR_ERR(req);
1368                 goto error;
1369         }
1370
1371         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1372         if (err) {
1373                 trace_9p_protocol_dump(clnt, req->rc);
1374                 goto free_and_error;
1375         }
1376
1377         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1378                                 qid.type,
1379                                 (unsigned long long)qid.path,
1380                                 qid.version, iounit);
1381
1382         fid->mode = mode;
1383         fid->iounit = iounit;
1384
1385 free_and_error:
1386         p9_free_req(clnt, req);
1387 error:
1388         return err;
1389 }
1390 EXPORT_SYMBOL(p9_client_fcreate);
1391
1392 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1393                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1394 {
1395         int err = 0;
1396         struct p9_client *clnt;
1397         struct p9_req_t *req;
1398
1399         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1400                         dfid->fid, name, symtgt);
1401         clnt = dfid->clnt;
1402
1403         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1404                         gid);
1405         if (IS_ERR(req)) {
1406                 err = PTR_ERR(req);
1407                 goto error;
1408         }
1409
1410         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1411         if (err) {
1412                 trace_9p_protocol_dump(clnt, req->rc);
1413                 goto free_and_error;
1414         }
1415
1416         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1417                         qid->type, (unsigned long long)qid->path, qid->version);
1418
1419 free_and_error:
1420         p9_free_req(clnt, req);
1421 error:
1422         return err;
1423 }
1424 EXPORT_SYMBOL(p9_client_symlink);
1425
1426 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1427 {
1428         struct p9_client *clnt;
1429         struct p9_req_t *req;
1430
1431         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1432                         dfid->fid, oldfid->fid, newname);
1433         clnt = dfid->clnt;
1434         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1435                         newname);
1436         if (IS_ERR(req))
1437                 return PTR_ERR(req);
1438
1439         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1440         p9_free_req(clnt, req);
1441         return 0;
1442 }
1443 EXPORT_SYMBOL(p9_client_link);
1444
1445 int p9_client_fsync(struct p9_fid *fid, int datasync)
1446 {
1447         int err;
1448         struct p9_client *clnt;
1449         struct p9_req_t *req;
1450
1451         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1452                         fid->fid, datasync);
1453         err = 0;
1454         clnt = fid->clnt;
1455
1456         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1457         if (IS_ERR(req)) {
1458                 err = PTR_ERR(req);
1459                 goto error;
1460         }
1461
1462         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1463
1464         p9_free_req(clnt, req);
1465
1466 error:
1467         return err;
1468 }
1469 EXPORT_SYMBOL(p9_client_fsync);
1470
1471 int p9_client_clunk(struct p9_fid *fid)
1472 {
1473         int err;
1474         struct p9_client *clnt;
1475         struct p9_req_t *req;
1476         int retries = 0;
1477
1478         if (!fid) {
1479                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1480                         __func__, task_pid_nr(current));
1481                 dump_stack();
1482                 return 0;
1483         }
1484
1485 again:
1486         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1487                                                                 retries);
1488         err = 0;
1489         clnt = fid->clnt;
1490
1491         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1492         if (IS_ERR(req)) {
1493                 err = PTR_ERR(req);
1494                 goto error;
1495         }
1496
1497         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1498
1499         p9_free_req(clnt, req);
1500 error:
1501         /*
1502          * Fid is not valid even after a failed clunk
1503          * If interrupted, retry once then give up and
1504          * leak fid until umount.
1505          */
1506         if (err == -ERESTARTSYS) {
1507                 if (retries++ == 0)
1508                         goto again;
1509         } else
1510                 p9_fid_destroy(fid);
1511         return err;
1512 }
1513 EXPORT_SYMBOL(p9_client_clunk);
1514
1515 int p9_client_remove(struct p9_fid *fid)
1516 {
1517         int err;
1518         struct p9_client *clnt;
1519         struct p9_req_t *req;
1520
1521         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1522         err = 0;
1523         clnt = fid->clnt;
1524
1525         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1526         if (IS_ERR(req)) {
1527                 err = PTR_ERR(req);
1528                 goto error;
1529         }
1530
1531         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1532
1533         p9_free_req(clnt, req);
1534 error:
1535         if (err == -ERESTARTSYS)
1536                 p9_client_clunk(fid);
1537         else
1538                 p9_fid_destroy(fid);
1539         return err;
1540 }
1541 EXPORT_SYMBOL(p9_client_remove);
1542
1543 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1544 {
1545         int err = 0;
1546         struct p9_req_t *req;
1547         struct p9_client *clnt;
1548
1549         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1550                    dfid->fid, name, flags);
1551
1552         clnt = dfid->clnt;
1553         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1554         if (IS_ERR(req)) {
1555                 err = PTR_ERR(req);
1556                 goto error;
1557         }
1558         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1559
1560         p9_free_req(clnt, req);
1561 error:
1562         return err;
1563 }
1564 EXPORT_SYMBOL(p9_client_unlinkat);
1565
1566 int
1567 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1568 {
1569         struct p9_client *clnt = fid->clnt;
1570         struct p9_req_t *req;
1571         int total = 0;
1572         *err = 0;
1573
1574         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1575                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1576
1577         while (iov_iter_count(to)) {
1578                 int count = iov_iter_count(to);
1579                 int rsize, non_zc = 0;
1580                 char *dataptr;
1581
1582                 rsize = fid->iounit;
1583                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1584                         rsize = clnt->msize - P9_IOHDRSZ;
1585
1586                 if (count < rsize)
1587                         rsize = count;
1588
1589                 /* Don't bother zerocopy for small IO (< 1024) */
1590                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1591                         /*
1592                          * response header len is 11
1593                          * PDU Header(7) + IO Size (4)
1594                          */
1595                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1596                                                0, 11, "dqd", fid->fid,
1597                                                offset, rsize);
1598                 } else {
1599                         non_zc = 1;
1600                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1601                                             rsize);
1602                 }
1603                 if (IS_ERR(req)) {
1604                         *err = PTR_ERR(req);
1605                         break;
1606                 }
1607
1608                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1609                                    "D", &count, &dataptr);
1610                 if (*err) {
1611                         trace_9p_protocol_dump(clnt, req->rc);
1612                         p9_free_req(clnt, req);
1613                         break;
1614                 }
1615                 if (rsize < count) {
1616                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1617                         count = rsize;
1618                 }
1619
1620                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1621                 if (!count) {
1622                         p9_free_req(clnt, req);
1623                         break;
1624                 }
1625
1626                 if (non_zc) {
1627                         int n = copy_to_iter(dataptr, count, to);
1628                         total += n;
1629                         offset += n;
1630                         if (n != count) {
1631                                 *err = -EFAULT;
1632                                 p9_free_req(clnt, req);
1633                                 break;
1634                         }
1635                 } else {
1636                         iov_iter_advance(to, count);
1637                         total += count;
1638                         offset += count;
1639                 }
1640                 p9_free_req(clnt, req);
1641         }
1642         return total;
1643 }
1644 EXPORT_SYMBOL(p9_client_read);
1645
1646 int
1647 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1648 {
1649         struct p9_client *clnt = fid->clnt;
1650         struct p9_req_t *req;
1651         int total = 0;
1652         *err = 0;
1653
1654         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1655                                 fid->fid, (unsigned long long) offset,
1656                                 iov_iter_count(from));
1657
1658         while (iov_iter_count(from)) {
1659                 int count = iov_iter_count(from);
1660                 int rsize = fid->iounit;
1661                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1662                         rsize = clnt->msize - P9_IOHDRSZ;
1663
1664                 if (count < rsize)
1665                         rsize = count;
1666
1667                 /* Don't bother zerocopy for small IO (< 1024) */
1668                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1669                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1670                                                rsize, P9_ZC_HDR_SZ, "dqd",
1671                                                fid->fid, offset, rsize);
1672                 } else {
1673                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1674                                                     offset, rsize, from);
1675                 }
1676                 if (IS_ERR(req)) {
1677                         *err = PTR_ERR(req);
1678                         break;
1679                 }
1680
1681                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1682                 if (*err) {
1683                         trace_9p_protocol_dump(clnt, req->rc);
1684                         p9_free_req(clnt, req);
1685                         break;
1686                 }
1687                 if (rsize < count) {
1688                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1689                         count = rsize;
1690                 }
1691
1692                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1693
1694                 p9_free_req(clnt, req);
1695                 iov_iter_advance(from, count);
1696                 total += count;
1697                 offset += count;
1698         }
1699         return total;
1700 }
1701 EXPORT_SYMBOL(p9_client_write);
1702
1703 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1704 {
1705         int err;
1706         struct p9_client *clnt;
1707         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1708         struct p9_req_t *req;
1709         u16 ignored;
1710
1711         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1712
1713         if (!ret)
1714                 return ERR_PTR(-ENOMEM);
1715
1716         err = 0;
1717         clnt = fid->clnt;
1718
1719         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1720         if (IS_ERR(req)) {
1721                 err = PTR_ERR(req);
1722                 goto error;
1723         }
1724
1725         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1726         if (err) {
1727                 trace_9p_protocol_dump(clnt, req->rc);
1728                 p9_free_req(clnt, req);
1729                 goto error;
1730         }
1731
1732         p9_debug(P9_DEBUG_9P,
1733                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1734                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1735                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1736                 "<<<    uid=%d gid=%d n_muid=%d\n",
1737                 ret->size, ret->type, ret->dev, ret->qid.type,
1738                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1739                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1740                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1741                 from_kuid(&init_user_ns, ret->n_uid),
1742                 from_kgid(&init_user_ns, ret->n_gid),
1743                 from_kuid(&init_user_ns, ret->n_muid));
1744
1745         p9_free_req(clnt, req);
1746         return ret;
1747
1748 error:
1749         kfree(ret);
1750         return ERR_PTR(err);
1751 }
1752 EXPORT_SYMBOL(p9_client_stat);
1753
1754 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1755                                                         u64 request_mask)
1756 {
1757         int err;
1758         struct p9_client *clnt;
1759         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1760                                                                 GFP_KERNEL);
1761         struct p9_req_t *req;
1762
1763         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1764                                                         fid->fid, request_mask);
1765
1766         if (!ret)
1767                 return ERR_PTR(-ENOMEM);
1768
1769         err = 0;
1770         clnt = fid->clnt;
1771
1772         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1773         if (IS_ERR(req)) {
1774                 err = PTR_ERR(req);
1775                 goto error;
1776         }
1777
1778         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1779         if (err) {
1780                 trace_9p_protocol_dump(clnt, req->rc);
1781                 p9_free_req(clnt, req);
1782                 goto error;
1783         }
1784
1785         p9_debug(P9_DEBUG_9P,
1786                 "<<< RGETATTR st_result_mask=%lld\n"
1787                 "<<< qid=%x.%llx.%x\n"
1788                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1789                 "<<< st_uid=%d st_gid=%d\n"
1790                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1791                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1792                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1793                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1794                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1795                 "<<< st_gen=%lld st_data_version=%lld",
1796                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1797                 ret->qid.version, ret->st_mode, ret->st_nlink,
1798                 from_kuid(&init_user_ns, ret->st_uid),
1799                 from_kgid(&init_user_ns, ret->st_gid),
1800                 ret->st_rdev, ret->st_size, ret->st_blksize,
1801                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1802                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1803                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1804                 ret->st_gen, ret->st_data_version);
1805
1806         p9_free_req(clnt, req);
1807         return ret;
1808
1809 error:
1810         kfree(ret);
1811         return ERR_PTR(err);
1812 }
1813 EXPORT_SYMBOL(p9_client_getattr_dotl);
1814
1815 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1816 {
1817         int ret;
1818
1819         /* NOTE: size shouldn't include its own length */
1820         /* size[2] type[2] dev[4] qid[13] */
1821         /* mode[4] atime[4] mtime[4] length[8]*/
1822         /* name[s] uid[s] gid[s] muid[s] */
1823         ret = 2+4+13+4+4+4+8+2+2+2+2;
1824
1825         if (wst->name)
1826                 ret += strlen(wst->name);
1827         if (wst->uid)
1828                 ret += strlen(wst->uid);
1829         if (wst->gid)
1830                 ret += strlen(wst->gid);
1831         if (wst->muid)
1832                 ret += strlen(wst->muid);
1833
1834         if ((proto_version == p9_proto_2000u) ||
1835                 (proto_version == p9_proto_2000L)) {
1836                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1837                 if (wst->extension)
1838                         ret += strlen(wst->extension);
1839         }
1840
1841         return ret;
1842 }
1843
1844 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1845 {
1846         int err;
1847         struct p9_req_t *req;
1848         struct p9_client *clnt;
1849
1850         err = 0;
1851         clnt = fid->clnt;
1852         wst->size = p9_client_statsize(wst, clnt->proto_version);
1853         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1854         p9_debug(P9_DEBUG_9P,
1855                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1856                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1857                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1858                 "     uid=%d gid=%d n_muid=%d\n",
1859                 wst->size, wst->type, wst->dev, wst->qid.type,
1860                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1861                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1862                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1863                 from_kuid(&init_user_ns, wst->n_uid),
1864                 from_kgid(&init_user_ns, wst->n_gid),
1865                 from_kuid(&init_user_ns, wst->n_muid));
1866
1867         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1868         if (IS_ERR(req)) {
1869                 err = PTR_ERR(req);
1870                 goto error;
1871         }
1872
1873         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1874
1875         p9_free_req(clnt, req);
1876 error:
1877         return err;
1878 }
1879 EXPORT_SYMBOL(p9_client_wstat);
1880
1881 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1882 {
1883         int err;
1884         struct p9_req_t *req;
1885         struct p9_client *clnt;
1886
1887         err = 0;
1888         clnt = fid->clnt;
1889         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1890         p9_debug(P9_DEBUG_9P,
1891                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1892                 "    atime_sec=%lld atime_nsec=%lld\n"
1893                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1894                 p9attr->valid, p9attr->mode,
1895                 from_kuid(&init_user_ns, p9attr->uid),
1896                 from_kgid(&init_user_ns, p9attr->gid),
1897                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1898                 p9attr->mtime_sec, p9attr->mtime_nsec);
1899
1900         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1901
1902         if (IS_ERR(req)) {
1903                 err = PTR_ERR(req);
1904                 goto error;
1905         }
1906         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1907         p9_free_req(clnt, req);
1908 error:
1909         return err;
1910 }
1911 EXPORT_SYMBOL(p9_client_setattr);
1912
1913 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1914 {
1915         int err;
1916         struct p9_req_t *req;
1917         struct p9_client *clnt;
1918
1919         err = 0;
1920         clnt = fid->clnt;
1921
1922         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1923
1924         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1925         if (IS_ERR(req)) {
1926                 err = PTR_ERR(req);
1927                 goto error;
1928         }
1929
1930         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1931                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1932                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1933         if (err) {
1934                 trace_9p_protocol_dump(clnt, req->rc);
1935                 p9_free_req(clnt, req);
1936                 goto error;
1937         }
1938
1939         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1940                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1941                 "fsid %llu namelen %ld\n",
1942                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1943                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1944                 sb->fsid, (long int)sb->namelen);
1945
1946         p9_free_req(clnt, req);
1947 error:
1948         return err;
1949 }
1950 EXPORT_SYMBOL(p9_client_statfs);
1951
1952 int p9_client_rename(struct p9_fid *fid,
1953                      struct p9_fid *newdirfid, const char *name)
1954 {
1955         int err;
1956         struct p9_req_t *req;
1957         struct p9_client *clnt;
1958
1959         err = 0;
1960         clnt = fid->clnt;
1961
1962         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1963                         fid->fid, newdirfid->fid, name);
1964
1965         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1966                         newdirfid->fid, name);
1967         if (IS_ERR(req)) {
1968                 err = PTR_ERR(req);
1969                 goto error;
1970         }
1971
1972         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1973
1974         p9_free_req(clnt, req);
1975 error:
1976         return err;
1977 }
1978 EXPORT_SYMBOL(p9_client_rename);
1979
1980 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1981                        struct p9_fid *newdirfid, const char *new_name)
1982 {
1983         int err;
1984         struct p9_req_t *req;
1985         struct p9_client *clnt;
1986
1987         err = 0;
1988         clnt = olddirfid->clnt;
1989
1990         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1991                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1992                    newdirfid->fid, new_name);
1993
1994         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1995                             old_name, newdirfid->fid, new_name);
1996         if (IS_ERR(req)) {
1997                 err = PTR_ERR(req);
1998                 goto error;
1999         }
2000
2001         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
2002                    newdirfid->fid, new_name);
2003
2004         p9_free_req(clnt, req);
2005 error:
2006         return err;
2007 }
2008 EXPORT_SYMBOL(p9_client_renameat);
2009
2010 /*
2011  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2012  */
2013 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2014                                 const char *attr_name, u64 *attr_size)
2015 {
2016         int err;
2017         struct p9_req_t *req;
2018         struct p9_client *clnt;
2019         struct p9_fid *attr_fid;
2020
2021         err = 0;
2022         clnt = file_fid->clnt;
2023         attr_fid = p9_fid_create(clnt);
2024         if (IS_ERR(attr_fid)) {
2025                 err = PTR_ERR(attr_fid);
2026                 attr_fid = NULL;
2027                 goto error;
2028         }
2029         p9_debug(P9_DEBUG_9P,
2030                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2031                 file_fid->fid, attr_fid->fid, attr_name);
2032
2033         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2034                         file_fid->fid, attr_fid->fid, attr_name);
2035         if (IS_ERR(req)) {
2036                 err = PTR_ERR(req);
2037                 goto error;
2038         }
2039         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2040         if (err) {
2041                 trace_9p_protocol_dump(clnt, req->rc);
2042                 p9_free_req(clnt, req);
2043                 goto clunk_fid;
2044         }
2045         p9_free_req(clnt, req);
2046         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2047                 attr_fid->fid, *attr_size);
2048         return attr_fid;
2049 clunk_fid:
2050         p9_client_clunk(attr_fid);
2051         attr_fid = NULL;
2052 error:
2053         if (attr_fid && (attr_fid != file_fid))
2054                 p9_fid_destroy(attr_fid);
2055
2056         return ERR_PTR(err);
2057 }
2058 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2059
2060 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2061                         u64 attr_size, int flags)
2062 {
2063         int err;
2064         struct p9_req_t *req;
2065         struct p9_client *clnt;
2066
2067         p9_debug(P9_DEBUG_9P,
2068                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2069                 fid->fid, name, (long long)attr_size, flags);
2070         err = 0;
2071         clnt = fid->clnt;
2072         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2073                         fid->fid, name, attr_size, flags);
2074         if (IS_ERR(req)) {
2075                 err = PTR_ERR(req);
2076                 goto error;
2077         }
2078         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2079         p9_free_req(clnt, req);
2080 error:
2081         return err;
2082 }
2083 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2084
2085 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2086 {
2087         int err, rsize, non_zc = 0;
2088         struct p9_client *clnt;
2089         struct p9_req_t *req;
2090         char *dataptr;
2091         struct kvec kv = {.iov_base = data, .iov_len = count};
2092         struct iov_iter to;
2093
2094         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2095
2096         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2097                                 fid->fid, (unsigned long long) offset, count);
2098
2099         err = 0;
2100         clnt = fid->clnt;
2101
2102         rsize = fid->iounit;
2103         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2104                 rsize = clnt->msize - P9_READDIRHDRSZ;
2105
2106         if (count < rsize)
2107                 rsize = count;
2108
2109         /* Don't bother zerocopy for small IO (< 1024) */
2110         if (clnt->trans_mod->zc_request && rsize > 1024) {
2111                 /*
2112                  * response header len is 11
2113                  * PDU Header(7) + IO Size (4)
2114                  */
2115                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2116                                        11, "dqd", fid->fid, offset, rsize);
2117         } else {
2118                 non_zc = 1;
2119                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2120                                     offset, rsize);
2121         }
2122         if (IS_ERR(req)) {
2123                 err = PTR_ERR(req);
2124                 goto error;
2125         }
2126
2127         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2128         if (err) {
2129                 trace_9p_protocol_dump(clnt, req->rc);
2130                 goto free_and_error;
2131         }
2132         if (rsize < count) {
2133                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2134                 count = rsize;
2135         }
2136
2137         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2138
2139         if (non_zc)
2140                 memmove(data, dataptr, count);
2141
2142         p9_free_req(clnt, req);
2143         return count;
2144
2145 free_and_error:
2146         p9_free_req(clnt, req);
2147 error:
2148         return err;
2149 }
2150 EXPORT_SYMBOL(p9_client_readdir);
2151
2152 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2153                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2154 {
2155         int err;
2156         struct p9_client *clnt;
2157         struct p9_req_t *req;
2158
2159         err = 0;
2160         clnt = fid->clnt;
2161         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2162                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2163         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2164                 MAJOR(rdev), MINOR(rdev), gid);
2165         if (IS_ERR(req))
2166                 return PTR_ERR(req);
2167
2168         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2169         if (err) {
2170                 trace_9p_protocol_dump(clnt, req->rc);
2171                 goto error;
2172         }
2173         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2174                                 (unsigned long long)qid->path, qid->version);
2175
2176 error:
2177         p9_free_req(clnt, req);
2178         return err;
2179
2180 }
2181 EXPORT_SYMBOL(p9_client_mknod_dotl);
2182
2183 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2184                                 kgid_t gid, struct p9_qid *qid)
2185 {
2186         int err;
2187         struct p9_client *clnt;
2188         struct p9_req_t *req;
2189
2190         err = 0;
2191         clnt = fid->clnt;
2192         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2193                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2194         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2195                 gid);
2196         if (IS_ERR(req))
2197                 return PTR_ERR(req);
2198
2199         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2200         if (err) {
2201                 trace_9p_protocol_dump(clnt, req->rc);
2202                 goto error;
2203         }
2204         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2205                                 (unsigned long long)qid->path, qid->version);
2206
2207 error:
2208         p9_free_req(clnt, req);
2209         return err;
2210
2211 }
2212 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2213
2214 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2215 {
2216         int err;
2217         struct p9_client *clnt;
2218         struct p9_req_t *req;
2219
2220         err = 0;
2221         clnt = fid->clnt;
2222         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2223                         "start %lld length %lld proc_id %d client_id %s\n",
2224                         fid->fid, flock->type, flock->flags, flock->start,
2225                         flock->length, flock->proc_id, flock->client_id);
2226
2227         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2228                                 flock->flags, flock->start, flock->length,
2229                                         flock->proc_id, flock->client_id);
2230
2231         if (IS_ERR(req))
2232                 return PTR_ERR(req);
2233
2234         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2235         if (err) {
2236                 trace_9p_protocol_dump(clnt, req->rc);
2237                 goto error;
2238         }
2239         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2240 error:
2241         p9_free_req(clnt, req);
2242         return err;
2243
2244 }
2245 EXPORT_SYMBOL(p9_client_lock_dotl);
2246
2247 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2248 {
2249         int err;
2250         struct p9_client *clnt;
2251         struct p9_req_t *req;
2252
2253         err = 0;
2254         clnt = fid->clnt;
2255         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2256                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2257                 glock->start, glock->length, glock->proc_id, glock->client_id);
2258
2259         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2260                 glock->start, glock->length, glock->proc_id, glock->client_id);
2261
2262         if (IS_ERR(req))
2263                 return PTR_ERR(req);
2264
2265         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2266                         &glock->start, &glock->length, &glock->proc_id,
2267                         &glock->client_id);
2268         if (err) {
2269                 trace_9p_protocol_dump(clnt, req->rc);
2270                 goto error;
2271         }
2272         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2273                 "proc_id %d client_id %s\n", glock->type, glock->start,
2274                 glock->length, glock->proc_id, glock->client_id);
2275 error:
2276         p9_free_req(clnt, req);
2277         return err;
2278 }
2279 EXPORT_SYMBOL(p9_client_getlock_dotl);
2280
2281 int p9_client_readlink(struct p9_fid *fid, char **target)
2282 {
2283         int err;
2284         struct p9_client *clnt;
2285         struct p9_req_t *req;
2286
2287         err = 0;
2288         clnt = fid->clnt;
2289         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2290
2291         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2292         if (IS_ERR(req))
2293                 return PTR_ERR(req);
2294
2295         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2296         if (err) {
2297                 trace_9p_protocol_dump(clnt, req->rc);
2298                 goto error;
2299         }
2300         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2301 error:
2302         p9_free_req(clnt, req);
2303         return err;
2304 }
2305 EXPORT_SYMBOL(p9_client_readlink);