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