net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <[email protected]>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <[email protected]>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/poll.h>
  32 #include <linux/idr.h>
  33 #include <linux/mutex.h>
  34 #include <linux/slab.h>
  35 #include <linux/sched/signal.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/uio.h>
  38 #include <net/9p/9p.h>
  39 #include <linux/parser.h>
  40 #include <linux/seq_file.h>
  41 #include <net/9p/client.h>
  42 #include <net/9p/transport.h>
  43 #include "protocol.h"
  44
  45 #define CREATE_TRACE_POINTS
  46 #include <trace/events/9p.h>
  47
  48 /*
  49   * Client Option Parsing (code inspired by NFS code)
  50   *  - a little lazy - parse all client options
  51   */
  52
  53 enum {
  54         Opt_msize,
  55         Opt_trans,
  56         Opt_legacy,
  57         Opt_version,
  58         Opt_err,
  59 };
  60
  61 static const match_table_t tokens = {
  62         {Opt_msize, "msize=%u"},
  63         {Opt_legacy, "noextend"},
  64         {Opt_trans, "trans=%s"},
  65         {Opt_version, "version=%s"},
  66         {Opt_err, NULL},
  67 };
  68
  69 inline int p9_is_proto_dotl(struct p9_client *clnt)
  70 {
  71         return clnt->proto_version == p9_proto_2000L;
  72 }
  73 EXPORT_SYMBOL(p9_is_proto_dotl);
  74
  75 inline int p9_is_proto_dotu(struct p9_client *clnt)
  76 {
  77         return clnt->proto_version == p9_proto_2000u;
  78 }
  79 EXPORT_SYMBOL(p9_is_proto_dotu);
  80
  81 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
  82 {
  83         if (clnt->msize != 8192)
  84                 seq_printf(m, ",msize=%u", clnt->msize);
  85         seq_printf(m, ",trans=%s", clnt->trans_mod->name);
  86
  87         switch (clnt->proto_version) {
  88         case p9_proto_legacy:
  89                 seq_puts(m, ",noextend");
  90                 break;
  91         case p9_proto_2000u:
  92                 seq_puts(m, ",version=9p2000.u");
  93                 break;
  94         case p9_proto_2000L:
  95                 /* Default */
  96                 break;
  97         }
  98
  99         if (clnt->trans_mod->show_options)
 100                 return clnt->trans_mod->show_options(m, clnt);
 101         return 0;
 102 }
 103 EXPORT_SYMBOL(p9_show_client_options);
 104
 105 /*
 106  * Some error codes are taken directly from the server replies,
 107  * make sure they are valid.
 108  */
 109 static int safe_errno(int err)
 110 {
 111         if ((err > 0) || (err < -MAX_ERRNO)) {
 112                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
 113                 return -EPROTO;
 114         }
 115         return err;
 116 }
 117
 118
 119 /* Interpret mount option for protocol version */
 120 static int get_protocol_version(char *s)
 121 {
 122         int version = -EINVAL;
 123
 124         if (!strcmp(s, "9p2000")) {
 125                 version = p9_proto_legacy;
 126                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
 127         } else if (!strcmp(s, "9p2000.u")) {
 128                 version = p9_proto_2000u;
 129                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
 130         } else if (!strcmp(s, "9p2000.L")) {
 131                 version = p9_proto_2000L;
 132                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
 133         } else
 134                 pr_info("Unknown protocol version %s\n", s);
 135
 136         return version;
 137 }
 138
 139 /**
 140  * parse_options - parse mount options into client structure
 141  * @opts: options string passed from mount
 142  * @clnt: existing v9fs client information
 143  *
 144  * Return 0 upon success, -ERRNO upon failure
 145  */
 146
 147 static int parse_opts(char *opts, struct p9_client *clnt)
 148 {
 149         char *options, *tmp_options;
 150         char *p;
 151         substring_t args[MAX_OPT_ARGS];
 152         int option;
 153         char *s;
 154         int ret = 0;
 155
 156         clnt->proto_version = p9_proto_2000L;
 157         clnt->msize = 8192;
 158
 159         if (!opts)
 160                 return 0;
 161
 162         tmp_options = kstrdup(opts, GFP_KERNEL);
 163         if (!tmp_options) {
 164                 p9_debug(P9_DEBUG_ERROR,
 165                          "failed to allocate copy of option string\n");
 166                 return -ENOMEM;
 167         }
 168         options = tmp_options;
 169
 170         while ((p = strsep(&options, ",")) != NULL) {
 171                 int token, r;
 172                 if (!*p)
 173                         continue;
 174                 token = match_token(p, tokens, args);
 175                 switch (token) {
 176                 case Opt_msize:
 177                         r = match_int(&args[0], &option);
 178                         if (r < 0) {
 179                                 p9_debug(P9_DEBUG_ERROR,
 180                                          "integer field, but no integer?\n");
 181                                 ret = r;
 182                                 continue;
 183                         }
 184                         clnt->msize = option;
 185                         break;
 186                 case Opt_trans:
 187                         s = match_strdup(&args[0]);
 188                         if (!s) {
 189                                 ret = -ENOMEM;
 190                                 p9_debug(P9_DEBUG_ERROR,
 191                                          "problem allocating copy of trans arg\n");
 192                                 goto free_and_return;
 193                         }
 194
 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                         }
 202                         kfree(s);
 203                         break;
 204                 case Opt_legacy:
 205                         clnt->proto_version = p9_proto_legacy;
 206                         break;
 207                 case Opt_version:
 208                         s = match_strdup(&args[0]);
 209                         if (!s) {
 210                                 ret = -ENOMEM;
 211                                 p9_debug(P9_DEBUG_ERROR,
 212                                          "problem allocating copy of version arg\n");
 213                                 goto free_and_return;
 214                         }
 215                         r = get_protocol_version(s);
 216                         if (r < 0)
 217                                 ret = r;
 218                         else
 219                                 clnt->proto_version = r;
 220                         kfree(s);
 221                         break;
 222                 default:
 223                         continue;
 224                 }
 225         }
 226
 227 free_and_return:
 228         if (ret)
 229                 v9fs_put_trans(clnt->trans_mod);
 230         kfree(tmp_options);
 231         return ret;
 232 }
 233
 234 static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
 235 {
 236         struct p9_fcall *fc;
 237         fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
 238         if (!fc)
 239                 return NULL;
 240         fc->capacity = alloc_msize;
 241         fc->sdata = (char *) fc + sizeof(struct p9_fcall);
 242         return fc;
 243 }
 244
 245 /**
 246  * p9_tag_alloc - lookup/allocate a request by tag
 247  * @c: client session to lookup tag within
 248  * @tag: numeric id for transaction
 249  *
 250  * this is a simple array lookup, but will grow the
 251  * request_slots as necessary to accommodate transaction
 252  * ids which did not previously have a slot.
 253  *
 254  * this code relies on the client spinlock to manage locks, its
 255  * possible we should switch to something else, but I'd rather
 256  * stick with something low-overhead for the common case.
 257  *
 258  */
 259
 260 static struct p9_req_t *
 261 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
 262 {
 263         unsigned long flags;
 264         int row, col;
 265         struct p9_req_t *req;
 266         int alloc_msize = min(c->msize, max_size);
 267
 268         /* This looks up the original request by tag so we know which
 269          * buffer to read the data into */
 270         tag++;
 271
 272         if (tag >= c->max_tag) {
 273                 spin_lock_irqsave(&c->lock, flags);
 274                 /* check again since original check was outside of lock */
 275                 while (tag >= c->max_tag) {
 276                         row = (tag / P9_ROW_MAXTAG);
 277                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 278                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 279
 280                         if (!c->reqs[row]) {
 281                                 pr_err("Couldn't grow tag array\n");
 282                                 spin_unlock_irqrestore(&c->lock, flags);
 283                                 return ERR_PTR(-ENOMEM);
 284                         }
 285                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 286                                 req = &c->reqs[row][col];
 287                                 req->status = REQ_STATUS_IDLE;
 288                                 init_waitqueue_head(&req->wq);
 289                         }
 290                         c->max_tag += P9_ROW_MAXTAG;
 291                 }
 292                 spin_unlock_irqrestore(&c->lock, flags);
 293         }
 294         row = tag / P9_ROW_MAXTAG;
 295         col = tag % P9_ROW_MAXTAG;
 296
 297         req = &c->reqs[row][col];
 298         if (!req->tc)
 299                 req->tc = p9_fcall_alloc(alloc_msize);
 300         if (!req->rc)
 301                 req->rc = p9_fcall_alloc(alloc_msize);
 302         if (!req->tc || !req->rc)
 303                 goto grow_failed;
 304
 305         p9pdu_reset(req->tc);
 306         p9pdu_reset(req->rc);
 307
 308         req->tc->tag = tag-1;
 309         req->status = REQ_STATUS_ALLOC;
 310
 311         return req;
 312
 313 grow_failed:
 314         pr_err("Couldn't grow tag array\n");
 315         kfree(req->tc);
 316         kfree(req->rc);
 317         req->tc = req->rc = NULL;
 318         return ERR_PTR(-ENOMEM);
 319 }
 320
 321 /**
 322  * p9_tag_lookup - lookup a request by tag
 323  * @c: client session to lookup tag within
 324  * @tag: numeric id for transaction
 325  *
 326  */
 327
 328 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 329 {
 330         int row, col;
 331
 332         /* This looks up the original request by tag so we know which
 333          * buffer to read the data into */
 334         tag++;
 335
 336         if (tag >= c->max_tag)
 337                 return NULL;
 338
 339         row = tag / P9_ROW_MAXTAG;
 340         col = tag % P9_ROW_MAXTAG;
 341
 342         return &c->reqs[row][col];
 343 }
 344 EXPORT_SYMBOL(p9_tag_lookup);
 345
 346 /**
 347  * p9_tag_init - setup tags structure and contents
 348  * @c:  v9fs client struct
 349  *
 350  * This initializes the tags structure for each client instance.
 351  *
 352  */
 353
 354 static int p9_tag_init(struct p9_client *c)
 355 {
 356         int err = 0;
 357
 358         c->tagpool = p9_idpool_create();
 359         if (IS_ERR(c->tagpool)) {
 360                 err = PTR_ERR(c->tagpool);
 361                 goto error;
 362         }
 363         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
 364         if (err < 0) {
 365                 p9_idpool_destroy(c->tagpool);
 366                 goto error;
 367         }
 368         c->max_tag = 0;
 369 error:
 370         return err;
 371 }
 372
 373 /**
 374  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 375  * @c:  v9fs client struct
 376  *
 377  * This frees resources associated with the tags structure
 378  *
 379  */
 380 static void p9_tag_cleanup(struct p9_client *c)
 381 {
 382         int row, col;
 383
 384         /* check to insure all requests are idle */
 385         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 386                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 387                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 388                                 p9_debug(P9_DEBUG_MUX,
 389                                          "Attempting to cleanup non-free tag %d,%d\n",
 390                                          row, col);
 391                                 /* TODO: delay execution of cleanup */
 392                                 return;
 393                         }
 394                 }
 395         }
 396
 397         if (c->tagpool) {
 398                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
 399                 p9_idpool_destroy(c->tagpool);
 400         }
 401
 402         /* free requests associated with tags */
 403         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 404                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 405                         kfree(c->reqs[row][col].tc);
 406                         kfree(c->reqs[row][col].rc);
 407                 }
 408                 kfree(c->reqs[row]);
 409         }
 410         c->max_tag = 0;
 411 }
 412
 413 /**
 414  * p9_free_req - free a request and clean-up as necessary
 415  * c: client state
 416  * r: request to release
 417  *
 418  */
 419
 420 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 421 {
 422         int tag = r->tc->tag;
 423         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 424
 425         r->status = REQ_STATUS_IDLE;
 426         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 427                 p9_idpool_put(tag, c->tagpool);
 428 }
 429
 430 /**
 431  * p9_client_cb - call back from transport to client
 432  * c: client state
 433  * req: request received
 434  *
 435  */
 436 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 437 {
 438         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 439
 440         /*
 441          * This barrier is needed to make sure any change made to req before
 442          * the status change is visible to another thread
 443          */
 444         smp_wmb();
 445         req->status = status;
 446
 447         wake_up(&req->wq);
 448         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 449 }
 450 EXPORT_SYMBOL(p9_client_cb);
 451
 452 /**
 453  * p9_parse_header - parse header arguments out of a packet
 454  * @pdu: packet to parse
 455  * @size: size of packet
 456  * @type: type of request
 457  * @tag: tag of packet
 458  * @rewind: set if we need to rewind offset afterwards
 459  */
 460
 461 int
 462 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 463                                                                 int rewind)
 464 {
 465         int8_t r_type;
 466         int16_t r_tag;
 467         int32_t r_size;
 468         int offset = pdu->offset;
 469         int err;
 470
 471         pdu->offset = 0;
 472
 473         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 474         if (err)
 475                 goto rewind_and_exit;
 476
 477         if (type)
 478                 *type = r_type;
 479         if (tag)
 480                 *tag = r_tag;
 481         if (size)
 482                 *size = r_size;
 483
 484         if (pdu->size != r_size || r_size < 7) {
 485                 err = -EINVAL;
 486                 goto rewind_and_exit;
 487         }
 488
 489         pdu->id = r_type;
 490         pdu->tag = r_tag;
 491
 492         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 493                  pdu->size, pdu->id, pdu->tag);
 494
 495 rewind_and_exit:
 496         if (rewind)
 497                 pdu->offset = offset;
 498         return err;
 499 }
 500 EXPORT_SYMBOL(p9_parse_header);
 501
 502 /**
 503  * p9_check_errors - check 9p packet for error return and process it
 504  * @c: current client instance
 505  * @req: request to parse and check for error conditions
 506  *
 507  * returns error code if one is discovered, otherwise returns 0
 508  *
 509  * this will have to be more complicated if we have multiple
 510  * error packet types
 511  */
 512
 513 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 514 {
 515         int8_t type;
 516         int err;
 517         int ecode;
 518
 519         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 520         if (req->rc->size >= c->msize) {
 521                 p9_debug(P9_DEBUG_ERROR,
 522                          "requested packet size too big: %d\n",
 523                          req->rc->size);
 524                 return -EIO;
 525         }
 526         /*
 527          * dump the response from server
 528          * This should be after check errors which poplulate pdu_fcall.
 529          */
 530         trace_9p_protocol_dump(c, req->rc);
 531         if (err) {
 532                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 533                 return err;
 534         }
 535         if (type != P9_RERROR && type != P9_RLERROR)
 536                 return 0;
 537
 538         if (!p9_is_proto_dotl(c)) {
 539                 char *ename;
 540                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 541                                   &ename, &ecode);
 542                 if (err)
 543                         goto out_err;
 544
 545                 if (p9_is_proto_dotu(c) && ecode < 512)
 546                         err = -ecode;
 547
 548                 if (!err) {
 549                         err = p9_errstr2errno(ename, strlen(ename));
 550
 551                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 552                                  -ecode, ename);
 553                 }
 554                 kfree(ename);
 555         } else {
 556                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 557                 err = -ecode;
 558
 559                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 560         }
 561
 562         return err;
 563
 564 out_err:
 565         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 566
 567         return err;
 568 }
 569
 570 /**
 571  * p9_check_zc_errors - check 9p packet for error return and process it
 572  * @c: current client instance
 573  * @req: request to parse and check for error conditions
 574  * @in_hdrlen: Size of response protocol buffer.
 575  *
 576  * returns error code if one is discovered, otherwise returns 0
 577  *
 578  * this will have to be more complicated if we have multiple
 579  * error packet types
 580  */
 581
 582 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 583                               struct iov_iter *uidata, int in_hdrlen)
 584 {
 585         int err;
 586         int ecode;
 587         int8_t type;
 588         char *ename = NULL;
 589
 590         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 591         /*
 592          * dump the response from server
 593          * This should be after parse_header which poplulate pdu_fcall.
 594          */
 595         trace_9p_protocol_dump(c, req->rc);
 596         if (err) {
 597                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 598                 return err;
 599         }
 600
 601         if (type != P9_RERROR && type != P9_RLERROR)
 602                 return 0;
 603
 604         if (!p9_is_proto_dotl(c)) {
 605                 /* Error is reported in string format */
 606                 int len;
 607                 /* 7 = header size for RERROR; */
 608                 int inline_len = in_hdrlen - 7;
 609
 610                 len =  req->rc->size - req->rc->offset;
 611                 if (len > (P9_ZC_HDR_SZ - 7)) {
 612                         err = -EFAULT;
 613                         goto out_err;
 614                 }
 615
 616                 ename = &req->rc->sdata[req->rc->offset];
 617                 if (len > inline_len) {
 618                         /* We have error in external buffer */
 619                         if (!copy_from_iter_full(ename + inline_len,
 620                                              len - inline_len, uidata)) {
 621                                 err = -EFAULT;
 622                                 goto out_err;
 623                         }
 624                 }
 625                 ename = NULL;
 626                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 627                                   &ename, &ecode);
 628                 if (err)
 629                         goto out_err;
 630
 631                 if (p9_is_proto_dotu(c) && ecode < 512)
 632                         err = -ecode;
 633
 634                 if (!err) {
 635                         err = p9_errstr2errno(ename, strlen(ename));
 636
 637                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 638                                  -ecode, ename);
 639                 }
 640                 kfree(ename);
 641         } else {
 642                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 643                 err = -ecode;
 644
 645                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 646         }
 647         return err;
 648
 649 out_err:
 650         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 651         return err;
 652 }
 653
 654 static struct p9_req_t *
 655 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 656
 657 /**
 658  * p9_client_flush - flush (cancel) a request
 659  * @c: client state
 660  * @oldreq: request to cancel
 661  *
 662  * This sents a flush for a particular request and links
 663  * the flush request to the original request.  The current
 664  * code only supports a single flush request although the protocol
 665  * allows for multiple flush requests to be sent for a single request.
 666  *
 667  */
 668
 669 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 670 {
 671         struct p9_req_t *req;
 672         int16_t oldtag;
 673         int err;
 674
 675         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 676         if (err)
 677                 return err;
 678
 679         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 680
 681         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 682         if (IS_ERR(req))
 683                 return PTR_ERR(req);
 684
 685         /*
 686          * if we haven't received a response for oldreq,
 687          * remove it from the list
 688          */
 689         if (oldreq->status == REQ_STATUS_SENT)
 690                 if (c->trans_mod->cancelled)
 691                         c->trans_mod->cancelled(c, oldreq);
 692
 693         p9_free_req(c, req);
 694         return 0;
 695 }
 696
 697 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 698                                               int8_t type, int req_size,
 699                                               const char *fmt, va_list ap)
 700 {
 701         int tag, err;
 702         struct p9_req_t *req;
 703
 704         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 705
 706         /* we allow for any status other than disconnected */
 707         if (c->status == Disconnected)
 708                 return ERR_PTR(-EIO);
 709
 710         /* if status is begin_disconnected we allow only clunk request */
 711         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 712                 return ERR_PTR(-EIO);
 713
 714         tag = P9_NOTAG;
 715         if (type != P9_TVERSION) {
 716                 tag = p9_idpool_get(c->tagpool);
 717                 if (tag < 0)
 718                         return ERR_PTR(-ENOMEM);
 719         }
 720
 721         req = p9_tag_alloc(c, tag, req_size);
 722         if (IS_ERR(req))
 723                 return req;
 724
 725         /* marshall the data */
 726         p9pdu_prepare(req->tc, tag, type);
 727         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 728         if (err)
 729                 goto reterr;
 730         p9pdu_finalize(c, req->tc);
 731         trace_9p_client_req(c, type, tag);
 732         return req;
 733 reterr:
 734         p9_free_req(c, req);
 735         return ERR_PTR(err);
 736 }
 737
 738 /**
 739  * p9_client_rpc - issue a request and wait for a response
 740  * @c: client session
 741  * @type: type of request
 742  * @fmt: protocol format string (see protocol.c)
 743  *
 744  * Returns request structure (which client must free using p9_free_req)
 745  */
 746
 747 static struct p9_req_t *
 748 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 749 {
 750         va_list ap;
 751         int sigpending, err;
 752         unsigned long flags;
 753         struct p9_req_t *req;
 754
 755         va_start(ap, fmt);
 756         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 757         va_end(ap);
 758         if (IS_ERR(req))
 759                 return req;
 760
 761         if (signal_pending(current)) {
 762                 sigpending = 1;
 763                 clear_thread_flag(TIF_SIGPENDING);
 764         } else
 765                 sigpending = 0;
 766
 767         err = c->trans_mod->request(c, req);
 768         if (err < 0) {
 769                 if (err != -ERESTARTSYS && err != -EFAULT)
 770                         c->status = Disconnected;
 771                 goto recalc_sigpending;
 772         }
 773 again:
 774         /* Wait for the response */
 775         err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
 776
 777         /*
 778          * Make sure our req is coherent with regard to updates in other
 779          * threads - echoes to wmb() in the callback
 780          */
 781         smp_rmb();
 782
 783         if ((err == -ERESTARTSYS) && (c->status == Connected)
 784                                   && (type == P9_TFLUSH)) {
 785                 sigpending = 1;
 786                 clear_thread_flag(TIF_SIGPENDING);
 787                 goto again;
 788         }
 789
 790         if (req->status == REQ_STATUS_ERROR) {
 791                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 792                 err = req->t_err;
 793         }
 794         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 795                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 796                 sigpending = 1;
 797                 clear_thread_flag(TIF_SIGPENDING);
 798
 799                 if (c->trans_mod->cancel(c, req))
 800                         p9_client_flush(c, req);
 801
 802                 /* if we received the response anyway, don't signal error */
 803                 if (req->status == REQ_STATUS_RCVD)
 804                         err = 0;
 805         }
 806 recalc_sigpending:
 807         if (sigpending) {
 808                 spin_lock_irqsave(&current->sighand->siglock, flags);
 809                 recalc_sigpending();
 810                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 811         }
 812         if (err < 0)
 813                 goto reterr;
 814
 815         err = p9_check_errors(c, req);
 816         trace_9p_client_res(c, type, req->rc->tag, err);
 817         if (!err)
 818                 return req;
 819 reterr:
 820         p9_free_req(c, req);
 821         return ERR_PTR(safe_errno(err));
 822 }
 823
 824 /**
 825  * p9_client_zc_rpc - issue a request and wait for a response
 826  * @c: client session
 827  * @type: type of request
 828  * @uidata: destination for zero copy read
 829  * @uodata: source for zero copy write
 830  * @inlen: read buffer size
 831  * @olen: write buffer size
 832  * @hdrlen: reader header size, This is the size of response protocol data
 833  * @fmt: protocol format string (see protocol.c)
 834  *
 835  * Returns request structure (which client must free using p9_free_req)
 836  */
 837 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 838                                          struct iov_iter *uidata,
 839                                          struct iov_iter *uodata,
 840                                          int inlen, int olen, int in_hdrlen,
 841                                          const char *fmt, ...)
 842 {
 843         va_list ap;
 844         int sigpending, err;
 845         unsigned long flags;
 846         struct p9_req_t *req;
 847
 848         va_start(ap, fmt);
 849         /*
 850          * We allocate a inline protocol data of only 4k bytes.
 851          * The actual content is passed in zero-copy fashion.
 852          */
 853         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 854         va_end(ap);
 855         if (IS_ERR(req))
 856                 return req;
 857
 858         if (signal_pending(current)) {
 859                 sigpending = 1;
 860                 clear_thread_flag(TIF_SIGPENDING);
 861         } else
 862                 sigpending = 0;
 863
 864         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 865                                        inlen, olen, in_hdrlen);
 866         if (err < 0) {
 867                 if (err == -EIO)
 868                         c->status = Disconnected;
 869                 if (err != -ERESTARTSYS)
 870                         goto recalc_sigpending;
 871         }
 872         if (req->status == REQ_STATUS_ERROR) {
 873                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 874                 err = req->t_err;
 875         }
 876         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 877                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 878                 sigpending = 1;
 879                 clear_thread_flag(TIF_SIGPENDING);
 880
 881                 if (c->trans_mod->cancel(c, req))
 882                         p9_client_flush(c, req);
 883
 884                 /* if we received the response anyway, don't signal error */
 885                 if (req->status == REQ_STATUS_RCVD)
 886                         err = 0;
 887         }
 888 recalc_sigpending:
 889         if (sigpending) {
 890                 spin_lock_irqsave(&current->sighand->siglock, flags);
 891                 recalc_sigpending();
 892                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 893         }
 894         if (err < 0)
 895                 goto reterr;
 896
 897         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 898         trace_9p_client_res(c, type, req->rc->tag, err);
 899         if (!err)
 900                 return req;
 901 reterr:
 902         p9_free_req(c, req);
 903         return ERR_PTR(safe_errno(err));
 904 }
 905
 906 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 907 {
 908         int ret;
 909         struct p9_fid *fid;
 910
 911         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 912         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 913         if (!fid)
 914                 return NULL;
 915
 916         memset(&fid->qid, 0, sizeof(struct p9_qid));
 917         fid->mode = -1;
 918         fid->uid = current_fsuid();
 919         fid->clnt = clnt;
 920         fid->rdir = NULL;
 921         fid->fid = 0;
 922
 923         idr_preload(GFP_KERNEL);
 924         spin_lock_irq(&clnt->lock);
 925         ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
 926                             GFP_NOWAIT);
 927         spin_unlock_irq(&clnt->lock);
 928         idr_preload_end();
 929
 930         if (!ret)
 931                 return fid;
 932
 933         kfree(fid);
 934         return NULL;
 935 }
 936
 937 static void p9_fid_destroy(struct p9_fid *fid)
 938 {
 939         struct p9_client *clnt;
 940         unsigned long flags;
 941
 942         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 943         clnt = fid->clnt;
 944         spin_lock_irqsave(&clnt->lock, flags);
 945         idr_remove(&clnt->fids, fid->fid);
 946         spin_unlock_irqrestore(&clnt->lock, flags);
 947         kfree(fid->rdir);
 948         kfree(fid);
 949 }
 950
 951 static int p9_client_version(struct p9_client *c)
 952 {
 953         int err = 0;
 954         struct p9_req_t *req;
 955         char *version = NULL;
 956         int msize;
 957
 958         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 959                  c->msize, c->proto_version);
 960
 961         switch (c->proto_version) {
 962         case p9_proto_2000L:
 963                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 964                                         c->msize, "9P2000.L");
 965                 break;
 966         case p9_proto_2000u:
 967                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 968                                         c->msize, "9P2000.u");
 969                 break;
 970         case p9_proto_legacy:
 971                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 972                                         c->msize, "9P2000");
 973                 break;
 974         default:
 975                 return -EINVAL;
 976         }
 977
 978         if (IS_ERR(req))
 979                 return PTR_ERR(req);
 980
 981         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 982         if (err) {
 983                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 984                 trace_9p_protocol_dump(c, req->rc);
 985                 goto error;
 986         }
 987
 988         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 989         if (!strncmp(version, "9P2000.L", 8))
 990                 c->proto_version = p9_proto_2000L;
 991         else if (!strncmp(version, "9P2000.u", 8))
 992                 c->proto_version = p9_proto_2000u;
 993         else if (!strncmp(version, "9P2000", 6))
 994                 c->proto_version = p9_proto_legacy;
 995         else {
 996                 err = -EREMOTEIO;
 997                 goto error;
 998         }
 999
1000         if (msize < c->msize)
1001                 c->msize = msize;
1002
1003 error:
1004         kfree(version);
1005         p9_free_req(c, req);
1006
1007         return err;
1008 }
1009
1010 struct p9_client *p9_client_create(const char *dev_name, char *options)
1011 {
1012         int err;
1013         struct p9_client *clnt;
1014         char *client_id;
1015
1016         err = 0;
1017         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1018         if (!clnt)
1019                 return ERR_PTR(-ENOMEM);
1020
1021         clnt->trans_mod = NULL;
1022         clnt->trans = NULL;
1023
1024         client_id = utsname()->nodename;
1025         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1026
1027         spin_lock_init(&clnt->lock);
1028         idr_init(&clnt->fids);
1029
1030         err = p9_tag_init(clnt);
1031         if (err < 0)
1032                 goto free_client;
1033
1034         err = parse_opts(options, clnt);
1035         if (err < 0)
1036                 goto destroy_tagpool;
1037
1038         if (!clnt->trans_mod)
1039                 clnt->trans_mod = v9fs_get_default_trans();
1040
1041         if (clnt->trans_mod == NULL) {
1042                 err = -EPROTONOSUPPORT;
1043                 p9_debug(P9_DEBUG_ERROR,
1044                          "No transport defined or default transport\n");
1045                 goto destroy_tagpool;
1046         }
1047
1048         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1049                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1050
1051         err = clnt->trans_mod->create(clnt, dev_name, options);
1052         if (err)
1053                 goto put_trans;
1054
1055         if (clnt->msize > clnt->trans_mod->maxsize)
1056                 clnt->msize = clnt->trans_mod->maxsize;
1057
1058         err = p9_client_version(clnt);
1059         if (err)
1060                 goto close_trans;
1061
1062         return clnt;
1063
1064 close_trans:
1065         clnt->trans_mod->close(clnt);
1066 put_trans:
1067         v9fs_put_trans(clnt->trans_mod);
1068 destroy_tagpool:
1069         p9_idpool_destroy(clnt->tagpool);
1070 free_client:
1071         kfree(clnt);
1072         return ERR_PTR(err);
1073 }
1074 EXPORT_SYMBOL(p9_client_create);
1075
1076 void p9_client_destroy(struct p9_client *clnt)
1077 {
1078         struct p9_fid *fid;
1079         int id;
1080
1081         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1082
1083         if (clnt->trans_mod)
1084                 clnt->trans_mod->close(clnt);
1085
1086         v9fs_put_trans(clnt->trans_mod);
1087
1088         idr_for_each_entry(&clnt->fids, fid, id) {
1089                 pr_info("Found fid %d not clunked\n", fid->fid);
1090                 p9_fid_destroy(fid);
1091         }
1092
1093         p9_tag_cleanup(clnt);
1094
1095         kfree(clnt);
1096 }
1097 EXPORT_SYMBOL(p9_client_destroy);
1098
1099 void p9_client_disconnect(struct p9_client *clnt)
1100 {
1101         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1102         clnt->status = Disconnected;
1103 }
1104 EXPORT_SYMBOL(p9_client_disconnect);
1105
1106 void p9_client_begin_disconnect(struct p9_client *clnt)
1107 {
1108         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1109         clnt->status = BeginDisconnect;
1110 }
1111 EXPORT_SYMBOL(p9_client_begin_disconnect);
1112
1113 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1114         const char *uname, kuid_t n_uname, const char *aname)
1115 {
1116         int err = 0;
1117         struct p9_req_t *req;
1118         struct p9_fid *fid;
1119         struct p9_qid qid;
1120
1121
1122         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1123                  afid ? afid->fid : -1, uname, aname);
1124         fid = p9_fid_create(clnt);
1125         if (!fid) {
1126                 err = -ENOMEM;
1127                 goto error;
1128         }
1129         fid->uid = n_uname;
1130
1131         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1132                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1133         if (IS_ERR(req)) {
1134                 err = PTR_ERR(req);
1135                 goto error;
1136         }
1137
1138         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1139         if (err) {
1140                 trace_9p_protocol_dump(clnt, req->rc);
1141                 p9_free_req(clnt, req);
1142                 goto error;
1143         }
1144
1145         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1146                  qid.type, (unsigned long long)qid.path, qid.version);
1147
1148         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1149
1150         p9_free_req(clnt, req);
1151         return fid;
1152
1153 error:
1154         if (fid)
1155                 p9_fid_destroy(fid);
1156         return ERR_PTR(err);
1157 }
1158 EXPORT_SYMBOL(p9_client_attach);
1159
1160 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1161                 const unsigned char * const *wnames, int clone)
1162 {
1163         int err;
1164         struct p9_client *clnt;
1165         struct p9_fid *fid;
1166         struct p9_qid *wqids;
1167         struct p9_req_t *req;
1168         uint16_t nwqids, count;
1169
1170         err = 0;
1171         wqids = NULL;
1172         clnt = oldfid->clnt;
1173         if (clone) {
1174                 fid = p9_fid_create(clnt);
1175                 if (!fid) {
1176                         err = -ENOMEM;
1177                         goto error;
1178                 }
1179
1180                 fid->uid = oldfid->uid;
1181         } else
1182                 fid = oldfid;
1183
1184
1185         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1186                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1187
1188         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1189                                                                 nwname, wnames);
1190         if (IS_ERR(req)) {
1191                 err = PTR_ERR(req);
1192                 goto error;
1193         }
1194
1195         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1196         if (err) {
1197                 trace_9p_protocol_dump(clnt, req->rc);
1198                 p9_free_req(clnt, req);
1199                 goto clunk_fid;
1200         }
1201         p9_free_req(clnt, req);
1202
1203         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1204
1205         if (nwqids != nwname) {
1206                 err = -ENOENT;
1207                 goto clunk_fid;
1208         }
1209
1210         for (count = 0; count < nwqids; count++)
1211                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1212                         count, wqids[count].type,
1213                         (unsigned long long)wqids[count].path,
1214                         wqids[count].version);
1215
1216         if (nwname)
1217                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1218         else
1219                 fid->qid = oldfid->qid;
1220
1221         kfree(wqids);
1222         return fid;
1223
1224 clunk_fid:
1225         kfree(wqids);
1226         p9_client_clunk(fid);
1227         fid = NULL;
1228
1229 error:
1230         if (fid && (fid != oldfid))
1231                 p9_fid_destroy(fid);
1232
1233         return ERR_PTR(err);
1234 }
1235 EXPORT_SYMBOL(p9_client_walk);
1236
1237 int p9_client_open(struct p9_fid *fid, int mode)
1238 {
1239         int err;
1240         struct p9_client *clnt;
1241         struct p9_req_t *req;
1242         struct p9_qid qid;
1243         int iounit;
1244
1245         clnt = fid->clnt;
1246         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1247                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1248         err = 0;
1249
1250         if (fid->mode != -1)
1251                 return -EINVAL;
1252
1253         if (p9_is_proto_dotl(clnt))
1254                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1255         else
1256                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1257         if (IS_ERR(req)) {
1258                 err = PTR_ERR(req);
1259                 goto error;
1260         }
1261
1262         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1263         if (err) {
1264                 trace_9p_protocol_dump(clnt, req->rc);
1265                 goto free_and_error;
1266         }
1267
1268         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1269                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1270                 (unsigned long long)qid.path, qid.version, iounit);
1271
1272         fid->mode = mode;
1273         fid->iounit = iounit;
1274
1275 free_and_error:
1276         p9_free_req(clnt, req);
1277 error:
1278         return err;
1279 }
1280 EXPORT_SYMBOL(p9_client_open);
1281
1282 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1283                 kgid_t gid, struct p9_qid *qid)
1284 {
1285         int err = 0;
1286         struct p9_client *clnt;
1287         struct p9_req_t *req;
1288         int iounit;
1289
1290         p9_debug(P9_DEBUG_9P,
1291                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1292                         ofid->fid, name, flags, mode,
1293                         from_kgid(&init_user_ns, gid));
1294         clnt = ofid->clnt;
1295
1296         if (ofid->mode != -1)
1297                 return -EINVAL;
1298
1299         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1300                         mode, gid);
1301         if (IS_ERR(req)) {
1302                 err = PTR_ERR(req);
1303                 goto error;
1304         }
1305
1306         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1307         if (err) {
1308                 trace_9p_protocol_dump(clnt, req->rc);
1309                 goto free_and_error;
1310         }
1311
1312         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1313                         qid->type,
1314                         (unsigned long long)qid->path,
1315                         qid->version, iounit);
1316
1317         ofid->mode = mode;
1318         ofid->iounit = iounit;
1319
1320 free_and_error:
1321         p9_free_req(clnt, req);
1322 error:
1323         return err;
1324 }
1325 EXPORT_SYMBOL(p9_client_create_dotl);
1326
1327 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1328                      char *extension)
1329 {
1330         int err;
1331         struct p9_client *clnt;
1332         struct p9_req_t *req;
1333         struct p9_qid qid;
1334         int iounit;
1335
1336         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1337                                                 fid->fid, name, perm, mode);
1338         err = 0;
1339         clnt = fid->clnt;
1340
1341         if (fid->mode != -1)
1342                 return -EINVAL;
1343
1344         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1345                                 mode, extension);
1346         if (IS_ERR(req)) {
1347                 err = PTR_ERR(req);
1348                 goto error;
1349         }
1350
1351         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1352         if (err) {
1353                 trace_9p_protocol_dump(clnt, req->rc);
1354                 goto free_and_error;
1355         }
1356
1357         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1358                                 qid.type,
1359                                 (unsigned long long)qid.path,
1360                                 qid.version, iounit);
1361
1362         fid->mode = mode;
1363         fid->iounit = iounit;
1364
1365 free_and_error:
1366         p9_free_req(clnt, req);
1367 error:
1368         return err;
1369 }
1370 EXPORT_SYMBOL(p9_client_fcreate);
1371
1372 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1373                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1374 {
1375         int err = 0;
1376         struct p9_client *clnt;
1377         struct p9_req_t *req;
1378
1379         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1380                         dfid->fid, name, symtgt);
1381         clnt = dfid->clnt;
1382
1383         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1384                         gid);
1385         if (IS_ERR(req)) {
1386                 err = PTR_ERR(req);
1387                 goto error;
1388         }
1389
1390         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1391         if (err) {
1392                 trace_9p_protocol_dump(clnt, req->rc);
1393                 goto free_and_error;
1394         }
1395
1396         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1397                         qid->type, (unsigned long long)qid->path, qid->version);
1398
1399 free_and_error:
1400         p9_free_req(clnt, req);
1401 error:
1402         return err;
1403 }
1404 EXPORT_SYMBOL(p9_client_symlink);
1405
1406 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1407 {
1408         struct p9_client *clnt;
1409         struct p9_req_t *req;
1410
1411         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1412                         dfid->fid, oldfid->fid, newname);
1413         clnt = dfid->clnt;
1414         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1415                         newname);
1416         if (IS_ERR(req))
1417                 return PTR_ERR(req);
1418
1419         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1420         p9_free_req(clnt, req);
1421         return 0;
1422 }
1423 EXPORT_SYMBOL(p9_client_link);
1424
1425 int p9_client_fsync(struct p9_fid *fid, int datasync)
1426 {
1427         int err;
1428         struct p9_client *clnt;
1429         struct p9_req_t *req;
1430
1431         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1432                         fid->fid, datasync);
1433         err = 0;
1434         clnt = fid->clnt;
1435
1436         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1437         if (IS_ERR(req)) {
1438                 err = PTR_ERR(req);
1439                 goto error;
1440         }
1441
1442         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1443
1444         p9_free_req(clnt, req);
1445
1446 error:
1447         return err;
1448 }
1449 EXPORT_SYMBOL(p9_client_fsync);
1450
1451 int p9_client_clunk(struct p9_fid *fid)
1452 {
1453         int err;
1454         struct p9_client *clnt;
1455         struct p9_req_t *req;
1456         int retries = 0;
1457
1458         if (!fid) {
1459                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1460                         __func__, task_pid_nr(current));
1461                 dump_stack();
1462                 return 0;
1463         }
1464
1465 again:
1466         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1467                                                                 retries);
1468         err = 0;
1469         clnt = fid->clnt;
1470
1471         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1472         if (IS_ERR(req)) {
1473                 err = PTR_ERR(req);
1474                 goto error;
1475         }
1476
1477         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1478
1479         p9_free_req(clnt, req);
1480 error:
1481         /*
1482          * Fid is not valid even after a failed clunk
1483          * If interrupted, retry once then give up and
1484          * leak fid until umount.
1485          */
1486         if (err == -ERESTARTSYS) {
1487                 if (retries++ == 0)
1488                         goto again;
1489         } else
1490                 p9_fid_destroy(fid);
1491         return err;
1492 }
1493 EXPORT_SYMBOL(p9_client_clunk);
1494
1495 int p9_client_remove(struct p9_fid *fid)
1496 {
1497         int err;
1498         struct p9_client *clnt;
1499         struct p9_req_t *req;
1500
1501         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1502         err = 0;
1503         clnt = fid->clnt;
1504
1505         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1506         if (IS_ERR(req)) {
1507                 err = PTR_ERR(req);
1508                 goto error;
1509         }
1510
1511         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1512
1513         p9_free_req(clnt, req);
1514 error:
1515         if (err == -ERESTARTSYS)
1516                 p9_client_clunk(fid);
1517         else
1518                 p9_fid_destroy(fid);
1519         return err;
1520 }
1521 EXPORT_SYMBOL(p9_client_remove);
1522
1523 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1524 {
1525         int err = 0;
1526         struct p9_req_t *req;
1527         struct p9_client *clnt;
1528
1529         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1530                    dfid->fid, name, flags);
1531
1532         clnt = dfid->clnt;
1533         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1534         if (IS_ERR(req)) {
1535                 err = PTR_ERR(req);
1536                 goto error;
1537         }
1538         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1539
1540         p9_free_req(clnt, req);
1541 error:
1542         return err;
1543 }
1544 EXPORT_SYMBOL(p9_client_unlinkat);
1545
1546 int
1547 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1548 {
1549         struct p9_client *clnt = fid->clnt;
1550         struct p9_req_t *req;
1551         int total = 0;
1552         *err = 0;
1553
1554         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1555                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1556
1557         while (iov_iter_count(to)) {
1558                 int count = iov_iter_count(to);
1559                 int rsize, non_zc = 0;
1560                 char *dataptr;
1561
1562                 rsize = fid->iounit;
1563                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1564                         rsize = clnt->msize - P9_IOHDRSZ;
1565
1566                 if (count < rsize)
1567                         rsize = count;
1568
1569                 /* Don't bother zerocopy for small IO (< 1024) */
1570                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1571                         /*
1572                          * response header len is 11
1573                          * PDU Header(7) + IO Size (4)
1574                          */
1575                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1576                                                0, 11, "dqd", fid->fid,
1577                                                offset, rsize);
1578                 } else {
1579                         non_zc = 1;
1580                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1581                                             rsize);
1582                 }
1583                 if (IS_ERR(req)) {
1584                         *err = PTR_ERR(req);
1585                         break;
1586                 }
1587
1588                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1589                                    "D", &count, &dataptr);
1590                 if (*err) {
1591                         trace_9p_protocol_dump(clnt, req->rc);
1592                         p9_free_req(clnt, req);
1593                         break;
1594                 }
1595                 if (rsize < count) {
1596                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1597                         count = rsize;
1598                 }
1599
1600                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1601                 if (!count) {
1602                         p9_free_req(clnt, req);
1603                         break;
1604                 }
1605
1606                 if (non_zc) {
1607                         int n = copy_to_iter(dataptr, count, to);
1608                         total += n;
1609                         offset += n;
1610                         if (n != count) {
1611                                 *err = -EFAULT;
1612                                 p9_free_req(clnt, req);
1613                                 break;
1614                         }
1615                 } else {
1616                         iov_iter_advance(to, count);
1617                         total += count;
1618                         offset += count;
1619                 }
1620                 p9_free_req(clnt, req);
1621         }
1622         return total;
1623 }
1624 EXPORT_SYMBOL(p9_client_read);
1625
1626 int
1627 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1628 {
1629         struct p9_client *clnt = fid->clnt;
1630         struct p9_req_t *req;
1631         int total = 0;
1632         *err = 0;
1633
1634         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1635                                 fid->fid, (unsigned long long) offset,
1636                                 iov_iter_count(from));
1637
1638         while (iov_iter_count(from)) {
1639                 int count = iov_iter_count(from);
1640                 int rsize = fid->iounit;
1641                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1642                         rsize = clnt->msize - P9_IOHDRSZ;
1643
1644                 if (count < rsize)
1645                         rsize = count;
1646
1647                 /* Don't bother zerocopy for small IO (< 1024) */
1648                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1649                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1650                                                rsize, P9_ZC_HDR_SZ, "dqd",
1651                                                fid->fid, offset, rsize);
1652                 } else {
1653                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1654                                                     offset, rsize, from);
1655                 }
1656                 if (IS_ERR(req)) {
1657                         *err = PTR_ERR(req);
1658                         break;
1659                 }
1660
1661                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1662                 if (*err) {
1663                         trace_9p_protocol_dump(clnt, req->rc);
1664                         p9_free_req(clnt, req);
1665                         break;
1666                 }
1667                 if (rsize < count) {
1668                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1669                         count = rsize;
1670                 }
1671
1672                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1673
1674                 p9_free_req(clnt, req);
1675                 iov_iter_advance(from, count);
1676                 total += count;
1677                 offset += count;
1678         }
1679         return total;
1680 }
1681 EXPORT_SYMBOL(p9_client_write);
1682
1683 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1684 {
1685         int err;
1686         struct p9_client *clnt;
1687         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1688         struct p9_req_t *req;
1689         u16 ignored;
1690
1691         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1692
1693         if (!ret)
1694                 return ERR_PTR(-ENOMEM);
1695
1696         err = 0;
1697         clnt = fid->clnt;
1698
1699         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1700         if (IS_ERR(req)) {
1701                 err = PTR_ERR(req);
1702                 goto error;
1703         }
1704
1705         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1706         if (err) {
1707                 trace_9p_protocol_dump(clnt, req->rc);
1708                 p9_free_req(clnt, req);
1709                 goto error;
1710         }
1711
1712         p9_debug(P9_DEBUG_9P,
1713                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1714                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1715                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1716                 "<<<    uid=%d gid=%d n_muid=%d\n",
1717                 ret->size, ret->type, ret->dev, ret->qid.type,
1718                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1719                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1720                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1721                 from_kuid(&init_user_ns, ret->n_uid),
1722                 from_kgid(&init_user_ns, ret->n_gid),
1723                 from_kuid(&init_user_ns, ret->n_muid));
1724
1725         p9_free_req(clnt, req);
1726         return ret;
1727
1728 error:
1729         kfree(ret);
1730         return ERR_PTR(err);
1731 }
1732 EXPORT_SYMBOL(p9_client_stat);
1733
1734 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1735                                                         u64 request_mask)
1736 {
1737         int err;
1738         struct p9_client *clnt;
1739         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1740                                                                 GFP_KERNEL);
1741         struct p9_req_t *req;
1742
1743         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1744                                                         fid->fid, request_mask);
1745
1746         if (!ret)
1747                 return ERR_PTR(-ENOMEM);
1748
1749         err = 0;
1750         clnt = fid->clnt;
1751
1752         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1753         if (IS_ERR(req)) {
1754                 err = PTR_ERR(req);
1755                 goto error;
1756         }
1757
1758         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1759         if (err) {
1760                 trace_9p_protocol_dump(clnt, req->rc);
1761                 p9_free_req(clnt, req);
1762                 goto error;
1763         }
1764
1765         p9_debug(P9_DEBUG_9P,
1766                 "<<< RGETATTR st_result_mask=%lld\n"
1767                 "<<< qid=%x.%llx.%x\n"
1768                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1769                 "<<< st_uid=%d st_gid=%d\n"
1770                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1771                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1772                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1773                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1774                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1775                 "<<< st_gen=%lld st_data_version=%lld\n",
1776                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1777                 ret->qid.version, ret->st_mode, ret->st_nlink,
1778                 from_kuid(&init_user_ns, ret->st_uid),
1779                 from_kgid(&init_user_ns, ret->st_gid),
1780                 ret->st_rdev, ret->st_size, ret->st_blksize,
1781                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1782                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1783                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1784                 ret->st_gen, ret->st_data_version);
1785
1786         p9_free_req(clnt, req);
1787         return ret;
1788
1789 error:
1790         kfree(ret);
1791         return ERR_PTR(err);
1792 }
1793 EXPORT_SYMBOL(p9_client_getattr_dotl);
1794
1795 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1796 {
1797         int ret;
1798
1799         /* NOTE: size shouldn't include its own length */
1800         /* size[2] type[2] dev[4] qid[13] */
1801         /* mode[4] atime[4] mtime[4] length[8]*/
1802         /* name[s] uid[s] gid[s] muid[s] */
1803         ret = 2+4+13+4+4+4+8+2+2+2+2;
1804
1805         if (wst->name)
1806                 ret += strlen(wst->name);
1807         if (wst->uid)
1808                 ret += strlen(wst->uid);
1809         if (wst->gid)
1810                 ret += strlen(wst->gid);
1811         if (wst->muid)
1812                 ret += strlen(wst->muid);
1813
1814         if ((proto_version == p9_proto_2000u) ||
1815                 (proto_version == p9_proto_2000L)) {
1816                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1817                 if (wst->extension)
1818                         ret += strlen(wst->extension);
1819         }
1820
1821         return ret;
1822 }
1823
1824 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1825 {
1826         int err;
1827         struct p9_req_t *req;
1828         struct p9_client *clnt;
1829
1830         err = 0;
1831         clnt = fid->clnt;
1832         wst->size = p9_client_statsize(wst, clnt->proto_version);
1833         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1834         p9_debug(P9_DEBUG_9P,
1835                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1836                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1837                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1838                 "     uid=%d gid=%d n_muid=%d\n",
1839                 wst->size, wst->type, wst->dev, wst->qid.type,
1840                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1841                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1842                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1843                 from_kuid(&init_user_ns, wst->n_uid),
1844                 from_kgid(&init_user_ns, wst->n_gid),
1845                 from_kuid(&init_user_ns, wst->n_muid));
1846
1847         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1848         if (IS_ERR(req)) {
1849                 err = PTR_ERR(req);
1850                 goto error;
1851         }
1852
1853         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1854
1855         p9_free_req(clnt, req);
1856 error:
1857         return err;
1858 }
1859 EXPORT_SYMBOL(p9_client_wstat);
1860
1861 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1862 {
1863         int err;
1864         struct p9_req_t *req;
1865         struct p9_client *clnt;
1866
1867         err = 0;
1868         clnt = fid->clnt;
1869         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1870         p9_debug(P9_DEBUG_9P,
1871                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1872                 "    atime_sec=%lld atime_nsec=%lld\n"
1873                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1874                 p9attr->valid, p9attr->mode,
1875                 from_kuid(&init_user_ns, p9attr->uid),
1876                 from_kgid(&init_user_ns, p9attr->gid),
1877                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1878                 p9attr->mtime_sec, p9attr->mtime_nsec);
1879
1880         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1881
1882         if (IS_ERR(req)) {
1883                 err = PTR_ERR(req);
1884                 goto error;
1885         }
1886         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1887         p9_free_req(clnt, req);
1888 error:
1889         return err;
1890 }
1891 EXPORT_SYMBOL(p9_client_setattr);
1892
1893 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1894 {
1895         int err;
1896         struct p9_req_t *req;
1897         struct p9_client *clnt;
1898
1899         err = 0;
1900         clnt = fid->clnt;
1901
1902         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1903
1904         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1905         if (IS_ERR(req)) {
1906                 err = PTR_ERR(req);
1907                 goto error;
1908         }
1909
1910         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1911                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1912                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1913         if (err) {
1914                 trace_9p_protocol_dump(clnt, req->rc);
1915                 p9_free_req(clnt, req);
1916                 goto error;
1917         }
1918
1919         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1920                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1921                 "fsid %llu namelen %ld\n",
1922                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1923                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1924                 sb->fsid, (long int)sb->namelen);
1925
1926         p9_free_req(clnt, req);
1927 error:
1928         return err;
1929 }
1930 EXPORT_SYMBOL(p9_client_statfs);
1931
1932 int p9_client_rename(struct p9_fid *fid,
1933                      struct p9_fid *newdirfid, const char *name)
1934 {
1935         int err;
1936         struct p9_req_t *req;
1937         struct p9_client *clnt;
1938
1939         err = 0;
1940         clnt = fid->clnt;
1941
1942         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1943                         fid->fid, newdirfid->fid, name);
1944
1945         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1946                         newdirfid->fid, name);
1947         if (IS_ERR(req)) {
1948                 err = PTR_ERR(req);
1949                 goto error;
1950         }
1951
1952         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1953
1954         p9_free_req(clnt, req);
1955 error:
1956         return err;
1957 }
1958 EXPORT_SYMBOL(p9_client_rename);
1959
1960 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1961                        struct p9_fid *newdirfid, const char *new_name)
1962 {
1963         int err;
1964         struct p9_req_t *req;
1965         struct p9_client *clnt;
1966
1967         err = 0;
1968         clnt = olddirfid->clnt;
1969
1970         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1971                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1972                    newdirfid->fid, new_name);
1973
1974         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1975                             old_name, newdirfid->fid, new_name);
1976         if (IS_ERR(req)) {
1977                 err = PTR_ERR(req);
1978                 goto error;
1979         }
1980
1981         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1982                    newdirfid->fid, new_name);
1983
1984         p9_free_req(clnt, req);
1985 error:
1986         return err;
1987 }
1988 EXPORT_SYMBOL(p9_client_renameat);
1989
1990 /*
1991  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1992  */
1993 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1994                                 const char *attr_name, u64 *attr_size)
1995 {
1996         int err;
1997         struct p9_req_t *req;
1998         struct p9_client *clnt;
1999         struct p9_fid *attr_fid;
2000
2001         err = 0;
2002         clnt = file_fid->clnt;
2003         attr_fid = p9_fid_create(clnt);
2004         if (!attr_fid) {
2005                 err = -ENOMEM;
2006                 goto error;
2007         }
2008         p9_debug(P9_DEBUG_9P,
2009                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2010                 file_fid->fid, attr_fid->fid, attr_name);
2011
2012         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2013                         file_fid->fid, attr_fid->fid, attr_name);
2014         if (IS_ERR(req)) {
2015                 err = PTR_ERR(req);
2016                 goto error;
2017         }
2018         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2019         if (err) {
2020                 trace_9p_protocol_dump(clnt, req->rc);
2021                 p9_free_req(clnt, req);
2022                 goto clunk_fid;
2023         }
2024         p9_free_req(clnt, req);
2025         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2026                 attr_fid->fid, *attr_size);
2027         return attr_fid;
2028 clunk_fid:
2029         p9_client_clunk(attr_fid);
2030         attr_fid = NULL;
2031 error:
2032         if (attr_fid && (attr_fid != file_fid))
2033                 p9_fid_destroy(attr_fid);
2034
2035         return ERR_PTR(err);
2036 }
2037 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2038
2039 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2040                         u64 attr_size, int flags)
2041 {
2042         int err;
2043         struct p9_req_t *req;
2044         struct p9_client *clnt;
2045
2046         p9_debug(P9_DEBUG_9P,
2047                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2048                 fid->fid, name, (long long)attr_size, flags);
2049         err = 0;
2050         clnt = fid->clnt;
2051         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2052                         fid->fid, name, attr_size, flags);
2053         if (IS_ERR(req)) {
2054                 err = PTR_ERR(req);
2055                 goto error;
2056         }
2057         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2058         p9_free_req(clnt, req);
2059 error:
2060         return err;
2061 }
2062 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2063
2064 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2065 {
2066         int err, rsize, non_zc = 0;
2067         struct p9_client *clnt;
2068         struct p9_req_t *req;
2069         char *dataptr;
2070         struct kvec kv = {.iov_base = data, .iov_len = count};
2071         struct iov_iter to;
2072
2073         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2074
2075         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2076                                 fid->fid, (unsigned long long) offset, count);
2077
2078         err = 0;
2079         clnt = fid->clnt;
2080
2081         rsize = fid->iounit;
2082         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2083                 rsize = clnt->msize - P9_READDIRHDRSZ;
2084
2085         if (count < rsize)
2086                 rsize = count;
2087
2088         /* Don't bother zerocopy for small IO (< 1024) */
2089         if (clnt->trans_mod->zc_request && rsize > 1024) {
2090                 /*
2091                  * response header len is 11
2092                  * PDU Header(7) + IO Size (4)
2093                  */
2094                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2095                                        11, "dqd", fid->fid, offset, rsize);
2096         } else {
2097                 non_zc = 1;
2098                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2099                                     offset, rsize);
2100         }
2101         if (IS_ERR(req)) {
2102                 err = PTR_ERR(req);
2103                 goto error;
2104         }
2105
2106         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2107         if (err) {
2108                 trace_9p_protocol_dump(clnt, req->rc);
2109                 goto free_and_error;
2110         }
2111         if (rsize < count) {
2112                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2113                 count = rsize;
2114         }
2115
2116         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2117
2118         if (non_zc)
2119                 memmove(data, dataptr, count);
2120
2121         p9_free_req(clnt, req);
2122         return count;
2123
2124 free_and_error:
2125         p9_free_req(clnt, req);
2126 error:
2127         return err;
2128 }
2129 EXPORT_SYMBOL(p9_client_readdir);
2130
2131 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2132                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2133 {
2134         int err;
2135         struct p9_client *clnt;
2136         struct p9_req_t *req;
2137
2138         err = 0;
2139         clnt = fid->clnt;
2140         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2141                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2142         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2143                 MAJOR(rdev), MINOR(rdev), gid);
2144         if (IS_ERR(req))
2145                 return PTR_ERR(req);
2146
2147         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2148         if (err) {
2149                 trace_9p_protocol_dump(clnt, req->rc);
2150                 goto error;
2151         }
2152         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2153                                 (unsigned long long)qid->path, qid->version);
2154
2155 error:
2156         p9_free_req(clnt, req);
2157         return err;
2158
2159 }
2160 EXPORT_SYMBOL(p9_client_mknod_dotl);
2161
2162 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2163                                 kgid_t gid, struct p9_qid *qid)
2164 {
2165         int err;
2166         struct p9_client *clnt;
2167         struct p9_req_t *req;
2168
2169         err = 0;
2170         clnt = fid->clnt;
2171         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2172                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2173         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2174                 gid);
2175         if (IS_ERR(req))
2176                 return PTR_ERR(req);
2177
2178         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2179         if (err) {
2180                 trace_9p_protocol_dump(clnt, req->rc);
2181                 goto error;
2182         }
2183         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2184                                 (unsigned long long)qid->path, qid->version);
2185
2186 error:
2187         p9_free_req(clnt, req);
2188         return err;
2189
2190 }
2191 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2192
2193 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2194 {
2195         int err;
2196         struct p9_client *clnt;
2197         struct p9_req_t *req;
2198
2199         err = 0;
2200         clnt = fid->clnt;
2201         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2202                         "start %lld length %lld proc_id %d client_id %s\n",
2203                         fid->fid, flock->type, flock->flags, flock->start,
2204                         flock->length, flock->proc_id, flock->client_id);
2205
2206         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2207                                 flock->flags, flock->start, flock->length,
2208                                         flock->proc_id, flock->client_id);
2209
2210         if (IS_ERR(req))
2211                 return PTR_ERR(req);
2212
2213         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2214         if (err) {
2215                 trace_9p_protocol_dump(clnt, req->rc);
2216                 goto error;
2217         }
2218         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2219 error:
2220         p9_free_req(clnt, req);
2221         return err;
2222
2223 }
2224 EXPORT_SYMBOL(p9_client_lock_dotl);
2225
2226 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2227 {
2228         int err;
2229         struct p9_client *clnt;
2230         struct p9_req_t *req;
2231
2232         err = 0;
2233         clnt = fid->clnt;
2234         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2235                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2236                 glock->start, glock->length, glock->proc_id, glock->client_id);
2237
2238         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2239                 glock->start, glock->length, glock->proc_id, glock->client_id);
2240
2241         if (IS_ERR(req))
2242                 return PTR_ERR(req);
2243
2244         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2245                         &glock->start, &glock->length, &glock->proc_id,
2246                         &glock->client_id);
2247         if (err) {
2248                 trace_9p_protocol_dump(clnt, req->rc);
2249                 goto error;
2250         }
2251         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2252                 "proc_id %d client_id %s\n", glock->type, glock->start,
2253                 glock->length, glock->proc_id, glock->client_id);
2254 error:
2255         p9_free_req(clnt, req);
2256         return err;
2257 }
2258 EXPORT_SYMBOL(p9_client_getlock_dotl);
2259
2260 int p9_client_readlink(struct p9_fid *fid, char **target)
2261 {
2262         int err;
2263         struct p9_client *clnt;
2264         struct p9_req_t *req;
2265
2266         err = 0;
2267         clnt = fid->clnt;
2268         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2269
2270         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2271         if (IS_ERR(req))
2272                 return PTR_ERR(req);
2273
2274         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2275         if (err) {
2276                 trace_9p_protocol_dump(clnt, req->rc);
2277                 goto error;
2278         }
2279         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2280 error:
2281         p9_free_req(clnt, req);
2282         return err;
2283 }
2284 EXPORT_SYMBOL(p9_client_readlink);