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 <linux/uio.h>
  38 #include <net/9p/9p.h>
  39 #include <linux/parser.h>
  40 #include <net/9p/client.h>
  41 #include <net/9p/transport.h>
  42 #include "protocol.h"
  43
  44 #define CREATE_TRACE_POINTS
  45 #include <trace/events/9p.h>
  46
  47 /*
  48   * Client Option Parsing (code inspired by NFS code)
  49   *  - a little lazy - parse all client options
  50   */
  51
  52 enum {
  53         Opt_msize,
  54         Opt_trans,
  55         Opt_legacy,
  56         Opt_version,
  57         Opt_err,
  58 };
  59
  60 static const match_table_t tokens = {
  61         {Opt_msize, "msize=%u"},
  62         {Opt_legacy, "noextend"},
  63         {Opt_trans, "trans=%s"},
  64         {Opt_version, "version=%s"},
  65         {Opt_err, NULL},
  66 };
  67
  68 inline int p9_is_proto_dotl(struct p9_client *clnt)
  69 {
  70         return clnt->proto_version == p9_proto_2000L;
  71 }
  72 EXPORT_SYMBOL(p9_is_proto_dotl);
  73
  74 inline int p9_is_proto_dotu(struct p9_client *clnt)
  75 {
  76         return clnt->proto_version == p9_proto_2000u;
  77 }
  78 EXPORT_SYMBOL(p9_is_proto_dotu);
  79
  80 /*
  81  * Some error codes are taken directly from the server replies,
  82  * make sure they are valid.
  83  */
  84 static int safe_errno(int err)
  85 {
  86         if ((err > 0) || (err < -MAX_ERRNO)) {
  87                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
  88                 return -EPROTO;
  89         }
  90         return err;
  91 }
  92
  93
  94 /* Interpret mount option for protocol version */
  95 static int get_protocol_version(char *s)
  96 {
  97         int version = -EINVAL;
  98
  99         if (!strcmp(s, "9p2000")) {
 100                 version = p9_proto_legacy;
 101                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
 102         } else if (!strcmp(s, "9p2000.u")) {
 103                 version = p9_proto_2000u;
 104                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
 105         } else if (!strcmp(s, "9p2000.L")) {
 106                 version = p9_proto_2000L;
 107                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
 108         } else
 109                 pr_info("Unknown protocol version %s\n", s);
 110
 111         return version;
 112 }
 113
 114 /**
 115  * parse_options - parse mount options into client structure
 116  * @opts: options string passed from mount
 117  * @clnt: existing v9fs client information
 118  *
 119  * Return 0 upon success, -ERRNO upon failure
 120  */
 121
 122 static int parse_opts(char *opts, struct p9_client *clnt)
 123 {
 124         char *options, *tmp_options;
 125         char *p;
 126         substring_t args[MAX_OPT_ARGS];
 127         int option;
 128         char *s;
 129         int ret = 0;
 130
 131         clnt->proto_version = p9_proto_2000L;
 132         clnt->msize = 8192;
 133
 134         if (!opts)
 135                 return 0;
 136
 137         tmp_options = kstrdup(opts, GFP_KERNEL);
 138         if (!tmp_options) {
 139                 p9_debug(P9_DEBUG_ERROR,
 140                          "failed to allocate copy of option string\n");
 141                 return -ENOMEM;
 142         }
 143         options = tmp_options;
 144
 145         while ((p = strsep(&options, ",")) != NULL) {
 146                 int token, r;
 147                 if (!*p)
 148                         continue;
 149                 token = match_token(p, tokens, args);
 150                 switch (token) {
 151                 case Opt_msize:
 152                         r = match_int(&args[0], &option);
 153                         if (r < 0) {
 154                                 p9_debug(P9_DEBUG_ERROR,
 155                                          "integer field, but no integer?\n");
 156                                 ret = r;
 157                                 continue;
 158                         }
 159                         if (option < 4096) {
 160                                 p9_debug(P9_DEBUG_ERROR,
 161                                          "msize should be at least 4k\n");
 162                                 ret = -EINVAL;
 163                                 continue;
 164                         }
 165                         clnt->msize = option;
 166                         break;
 167                 case Opt_trans:
 168                         s = match_strdup(&args[0]);
 169                         if (!s) {
 170                                 ret = -ENOMEM;
 171                                 p9_debug(P9_DEBUG_ERROR,
 172                                          "problem allocating copy of trans arg\n");
 173                                 goto free_and_return;
 174                          }
 175                         clnt->trans_mod = v9fs_get_trans_by_name(s);
 176                         if (clnt->trans_mod == NULL) {
 177                                 pr_info("Could not find request transport: %s\n",
 178                                         s);
 179                                 ret = -EINVAL;
 180                                 kfree(s);
 181                                 goto free_and_return;
 182                         }
 183                         kfree(s);
 184                         break;
 185                 case Opt_legacy:
 186                         clnt->proto_version = p9_proto_legacy;
 187                         break;
 188                 case Opt_version:
 189                         s = match_strdup(&args[0]);
 190                         if (!s) {
 191                                 ret = -ENOMEM;
 192                                 p9_debug(P9_DEBUG_ERROR,
 193                                          "problem allocating copy of version arg\n");
 194                                 goto free_and_return;
 195                         }
 196                         ret = get_protocol_version(s);
 197                         if (ret == -EINVAL) {
 198                                 kfree(s);
 199                                 goto free_and_return;
 200                         }
 201                         kfree(s);
 202                         clnt->proto_version = ret;
 203                         break;
 204                 default:
 205                         continue;
 206                 }
 207         }
 208
 209 free_and_return:
 210         kfree(tmp_options);
 211         return ret;
 212 }
 213
 214 static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
 215 {
 216         struct p9_fcall *fc;
 217         fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
 218         if (!fc)
 219                 return NULL;
 220         fc->capacity = alloc_msize;
 221         fc->sdata = (char *) fc + sizeof(struct p9_fcall);
 222         return fc;
 223 }
 224
 225 /**
 226  * p9_tag_alloc - lookup/allocate a request by tag
 227  * @c: client session to lookup tag within
 228  * @tag: numeric id for transaction
 229  *
 230  * this is a simple array lookup, but will grow the
 231  * request_slots as necessary to accommodate transaction
 232  * ids which did not previously have a slot.
 233  *
 234  * this code relies on the client spinlock to manage locks, its
 235  * possible we should switch to something else, but I'd rather
 236  * stick with something low-overhead for the common case.
 237  *
 238  */
 239
 240 static struct p9_req_t *
 241 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
 242 {
 243         unsigned long flags;
 244         int row, col;
 245         struct p9_req_t *req;
 246         int alloc_msize = min(c->msize, max_size);
 247
 248         /* This looks up the original request by tag so we know which
 249          * buffer to read the data into */
 250         tag++;
 251
 252         if (tag >= c->max_tag) {
 253                 spin_lock_irqsave(&c->lock, flags);
 254                 /* check again since original check was outside of lock */
 255                 while (tag >= c->max_tag) {
 256                         row = (tag / P9_ROW_MAXTAG);
 257                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 258                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 259
 260                         if (!c->reqs[row]) {
 261                                 pr_err("Couldn't grow tag array\n");
 262                                 spin_unlock_irqrestore(&c->lock, flags);
 263                                 return ERR_PTR(-ENOMEM);
 264                         }
 265                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 266                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 267                                 c->reqs[row][col].tc = NULL;
 268                         }
 269                         c->max_tag += P9_ROW_MAXTAG;
 270                 }
 271                 spin_unlock_irqrestore(&c->lock, flags);
 272         }
 273         row = tag / P9_ROW_MAXTAG;
 274         col = tag % P9_ROW_MAXTAG;
 275
 276         req = &c->reqs[row][col];
 277         if (!req->wq) {
 278                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
 279                 if (!req->wq)
 280                         goto grow_failed;
 281                 init_waitqueue_head(req->wq);
 282         }
 283
 284         if (!req->tc)
 285                 req->tc = p9_fcall_alloc(alloc_msize);
 286         if (!req->rc)
 287                 req->rc = p9_fcall_alloc(alloc_msize);
 288         if (!req->tc || !req->rc)
 289                 goto grow_failed;
 290
 291         p9pdu_reset(req->tc);
 292         p9pdu_reset(req->rc);
 293
 294         req->tc->tag = tag-1;
 295         req->status = REQ_STATUS_ALLOC;
 296
 297         return req;
 298
 299 grow_failed:
 300         pr_err("Couldn't grow tag array\n");
 301         kfree(req->tc);
 302         kfree(req->rc);
 303         kfree(req->wq);
 304         req->tc = req->rc = NULL;
 305         req->wq = NULL;
 306         return ERR_PTR(-ENOMEM);
 307 }
 308
 309 /**
 310  * p9_tag_lookup - lookup a request by tag
 311  * @c: client session to lookup tag within
 312  * @tag: numeric id for transaction
 313  *
 314  */
 315
 316 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 317 {
 318         int row, col;
 319
 320         /* This looks up the original request by tag so we know which
 321          * buffer to read the data into */
 322         tag++;
 323
 324         if(tag >= c->max_tag)
 325                 return NULL;
 326
 327         row = tag / P9_ROW_MAXTAG;
 328         col = tag % P9_ROW_MAXTAG;
 329
 330         return &c->reqs[row][col];
 331 }
 332 EXPORT_SYMBOL(p9_tag_lookup);
 333
 334 /**
 335  * p9_tag_init - setup tags structure and contents
 336  * @c:  v9fs client struct
 337  *
 338  * This initializes the tags structure for each client instance.
 339  *
 340  */
 341
 342 static int p9_tag_init(struct p9_client *c)
 343 {
 344         int err = 0;
 345
 346         c->tagpool = p9_idpool_create();
 347         if (IS_ERR(c->tagpool)) {
 348                 err = PTR_ERR(c->tagpool);
 349                 goto error;
 350         }
 351         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
 352         if (err < 0) {
 353                 p9_idpool_destroy(c->tagpool);
 354                 goto error;
 355         }
 356         c->max_tag = 0;
 357 error:
 358         return err;
 359 }
 360
 361 /**
 362  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 363  * @c:  v9fs client struct
 364  *
 365  * This frees resources associated with the tags structure
 366  *
 367  */
 368 static void p9_tag_cleanup(struct p9_client *c)
 369 {
 370         int row, col;
 371
 372         /* check to insure all requests are idle */
 373         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 374                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 375                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 376                                 p9_debug(P9_DEBUG_MUX,
 377                                          "Attempting to cleanup non-free tag %d,%d\n",
 378                                          row, col);
 379                                 /* TODO: delay execution of cleanup */
 380                                 return;
 381                         }
 382                 }
 383         }
 384
 385         if (c->tagpool) {
 386                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
 387                 p9_idpool_destroy(c->tagpool);
 388         }
 389
 390         /* free requests associated with tags */
 391         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 392                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 393                         kfree(c->reqs[row][col].wq);
 394                         kfree(c->reqs[row][col].tc);
 395                         kfree(c->reqs[row][col].rc);
 396                 }
 397                 kfree(c->reqs[row]);
 398         }
 399         c->max_tag = 0;
 400 }
 401
 402 /**
 403  * p9_free_req - free a request and clean-up as necessary
 404  * c: client state
 405  * r: request to release
 406  *
 407  */
 408
 409 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 410 {
 411         int tag = r->tc->tag;
 412         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 413
 414         r->status = REQ_STATUS_IDLE;
 415         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 416                 p9_idpool_put(tag, c->tagpool);
 417 }
 418
 419 /**
 420  * p9_client_cb - call back from transport to client
 421  * c: client state
 422  * req: request received
 423  *
 424  */
 425 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 426 {
 427         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 428
 429         /*
 430          * This barrier is needed to make sure any change made to req before
 431          * the other thread wakes up will indeed be seen by the waiting side.
 432          */
 433         smp_wmb();
 434         req->status = status;
 435
 436         wake_up(req->wq);
 437         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 438 }
 439 EXPORT_SYMBOL(p9_client_cb);
 440
 441 /**
 442  * p9_parse_header - parse header arguments out of a packet
 443  * @pdu: packet to parse
 444  * @size: size of packet
 445  * @type: type of request
 446  * @tag: tag of packet
 447  * @rewind: set if we need to rewind offset afterwards
 448  */
 449
 450 int
 451 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 452                                                                 int rewind)
 453 {
 454         int8_t r_type;
 455         int16_t r_tag;
 456         int32_t r_size;
 457         int offset = pdu->offset;
 458         int err;
 459
 460         pdu->offset = 0;
 461         if (pdu->size == 0)
 462                 pdu->size = 7;
 463
 464         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 465         if (err)
 466                 goto rewind_and_exit;
 467
 468         pdu->size = r_size;
 469         pdu->id = r_type;
 470         pdu->tag = r_tag;
 471
 472         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 473                  pdu->size, pdu->id, pdu->tag);
 474
 475         if (type)
 476                 *type = r_type;
 477         if (tag)
 478                 *tag = r_tag;
 479         if (size)
 480                 *size = r_size;
 481
 482
 483 rewind_and_exit:
 484         if (rewind)
 485                 pdu->offset = offset;
 486         return err;
 487 }
 488 EXPORT_SYMBOL(p9_parse_header);
 489
 490 /**
 491  * p9_check_errors - check 9p packet for error return and process it
 492  * @c: current client instance
 493  * @req: request to parse and check for error conditions
 494  *
 495  * returns error code if one is discovered, otherwise returns 0
 496  *
 497  * this will have to be more complicated if we have multiple
 498  * error packet types
 499  */
 500
 501 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 502 {
 503         int8_t type;
 504         int err;
 505         int ecode;
 506
 507         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 508         /*
 509          * dump the response from server
 510          * This should be after check errors which poplulate pdu_fcall.
 511          */
 512         trace_9p_protocol_dump(c, req->rc);
 513         if (err) {
 514                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 515                 return err;
 516         }
 517         if (type != P9_RERROR && type != P9_RLERROR)
 518                 return 0;
 519
 520         if (!p9_is_proto_dotl(c)) {
 521                 char *ename;
 522                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 523                                   &ename, &ecode);
 524                 if (err)
 525                         goto out_err;
 526
 527                 if (p9_is_proto_dotu(c))
 528                         err = -ecode;
 529
 530                 if (!err || !IS_ERR_VALUE(err)) {
 531                         err = p9_errstr2errno(ename, strlen(ename));
 532
 533                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 534                                  -ecode, ename);
 535                 }
 536                 kfree(ename);
 537         } else {
 538                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 539                 err = -ecode;
 540
 541                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 542         }
 543
 544         return err;
 545
 546 out_err:
 547         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 548
 549         return err;
 550 }
 551
 552 /**
 553  * p9_check_zc_errors - check 9p packet for error return and process it
 554  * @c: current client instance
 555  * @req: request to parse and check for error conditions
 556  * @in_hdrlen: Size of response protocol buffer.
 557  *
 558  * returns error code if one is discovered, otherwise returns 0
 559  *
 560  * this will have to be more complicated if we have multiple
 561  * error packet types
 562  */
 563
 564 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 565                               struct iov_iter *uidata, int in_hdrlen)
 566 {
 567         int err;
 568         int ecode;
 569         int8_t type;
 570         char *ename = NULL;
 571
 572         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 573         /*
 574          * dump the response from server
 575          * This should be after parse_header which poplulate pdu_fcall.
 576          */
 577         trace_9p_protocol_dump(c, req->rc);
 578         if (err) {
 579                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 580                 return err;
 581         }
 582
 583         if (type != P9_RERROR && type != P9_RLERROR)
 584                 return 0;
 585
 586         if (!p9_is_proto_dotl(c)) {
 587                 /* Error is reported in string format */
 588                 int len;
 589                 /* 7 = header size for RERROR; */
 590                 int inline_len = in_hdrlen - 7;
 591
 592                 len =  req->rc->size - req->rc->offset;
 593                 if (len > (P9_ZC_HDR_SZ - 7)) {
 594                         err = -EFAULT;
 595                         goto out_err;
 596                 }
 597
 598                 ename = &req->rc->sdata[req->rc->offset];
 599                 if (len > inline_len) {
 600                         /* We have error in external buffer */
 601                         err = copy_from_iter(ename + inline_len,
 602                                              len - inline_len, uidata);
 603                         if (err != len - inline_len) {
 604                                 err = -EFAULT;
 605                                 goto out_err;
 606                         }
 607                 }
 608                 ename = NULL;
 609                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 610                                   &ename, &ecode);
 611                 if (err)
 612                         goto out_err;
 613
 614                 if (p9_is_proto_dotu(c))
 615                         err = -ecode;
 616
 617                 if (!err || !IS_ERR_VALUE(err)) {
 618                         err = p9_errstr2errno(ename, strlen(ename));
 619
 620                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 621                                  -ecode, ename);
 622                 }
 623                 kfree(ename);
 624         } else {
 625                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 626                 err = -ecode;
 627
 628                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 629         }
 630         return err;
 631
 632 out_err:
 633         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 634         return err;
 635 }
 636
 637 static struct p9_req_t *
 638 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 639
 640 /**
 641  * p9_client_flush - flush (cancel) a request
 642  * @c: client state
 643  * @oldreq: request to cancel
 644  *
 645  * This sents a flush for a particular request and links
 646  * the flush request to the original request.  The current
 647  * code only supports a single flush request although the protocol
 648  * allows for multiple flush requests to be sent for a single request.
 649  *
 650  */
 651
 652 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 653 {
 654         struct p9_req_t *req;
 655         int16_t oldtag;
 656         int err;
 657
 658         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 659         if (err)
 660                 return err;
 661
 662         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 663
 664         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 665         if (IS_ERR(req))
 666                 return PTR_ERR(req);
 667
 668         /*
 669          * if we haven't received a response for oldreq,
 670          * remove it from the list
 671          */
 672         if (oldreq->status == REQ_STATUS_SENT)
 673                 if (c->trans_mod->cancelled)
 674                         c->trans_mod->cancelled(c, oldreq);
 675
 676         p9_free_req(c, req);
 677         return 0;
 678 }
 679
 680 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 681                                               int8_t type, int req_size,
 682                                               const char *fmt, va_list ap)
 683 {
 684         int tag, err;
 685         struct p9_req_t *req;
 686
 687         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 688
 689         /* we allow for any status other than disconnected */
 690         if (c->status == Disconnected)
 691                 return ERR_PTR(-EIO);
 692
 693         /* if status is begin_disconnected we allow only clunk request */
 694         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 695                 return ERR_PTR(-EIO);
 696
 697         tag = P9_NOTAG;
 698         if (type != P9_TVERSION) {
 699                 tag = p9_idpool_get(c->tagpool);
 700                 if (tag < 0)
 701                         return ERR_PTR(-ENOMEM);
 702         }
 703
 704         req = p9_tag_alloc(c, tag, req_size);
 705         if (IS_ERR(req))
 706                 return req;
 707
 708         /* marshall the data */
 709         p9pdu_prepare(req->tc, tag, type);
 710         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 711         if (err)
 712                 goto reterr;
 713         p9pdu_finalize(c, req->tc);
 714         trace_9p_client_req(c, type, tag);
 715         return req;
 716 reterr:
 717         p9_free_req(c, req);
 718         return ERR_PTR(err);
 719 }
 720
 721 /**
 722  * p9_client_rpc - issue a request and wait for a response
 723  * @c: client session
 724  * @type: type of request
 725  * @fmt: protocol format string (see protocol.c)
 726  *
 727  * Returns request structure (which client must free using p9_free_req)
 728  */
 729
 730 static struct p9_req_t *
 731 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 732 {
 733         va_list ap;
 734         int sigpending, err;
 735         unsigned long flags;
 736         struct p9_req_t *req;
 737
 738         va_start(ap, fmt);
 739         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 740         va_end(ap);
 741         if (IS_ERR(req))
 742                 return req;
 743
 744         if (signal_pending(current)) {
 745                 sigpending = 1;
 746                 clear_thread_flag(TIF_SIGPENDING);
 747         } else
 748                 sigpending = 0;
 749
 750         err = c->trans_mod->request(c, req);
 751         if (err < 0) {
 752                 if (err != -ERESTARTSYS && err != -EFAULT)
 753                         c->status = Disconnected;
 754                 goto reterr;
 755         }
 756 again:
 757         /* Wait for the response */
 758         err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD);
 759
 760         /*
 761          * Make sure our req is coherent with regard to updates in other
 762          * threads - echoes to wmb() in the callback
 763          */
 764         smp_rmb();
 765
 766         if ((err == -ERESTARTSYS) && (c->status == Connected)
 767                                   && (type == P9_TFLUSH)) {
 768                 sigpending = 1;
 769                 clear_thread_flag(TIF_SIGPENDING);
 770                 goto again;
 771         }
 772
 773         if (req->status == REQ_STATUS_ERROR) {
 774                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 775                 err = req->t_err;
 776         }
 777         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 778                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 779                 sigpending = 1;
 780                 clear_thread_flag(TIF_SIGPENDING);
 781
 782                 if (c->trans_mod->cancel(c, req))
 783                         p9_client_flush(c, req);
 784
 785                 /* if we received the response anyway, don't signal error */
 786                 if (req->status == REQ_STATUS_RCVD)
 787                         err = 0;
 788         }
 789         if (sigpending) {
 790                 spin_lock_irqsave(&current->sighand->siglock, flags);
 791                 recalc_sigpending();
 792                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 793         }
 794         if (err < 0)
 795                 goto reterr;
 796
 797         err = p9_check_errors(c, req);
 798         trace_9p_client_res(c, type, req->rc->tag, err);
 799         if (!err)
 800                 return req;
 801 reterr:
 802         p9_free_req(c, req);
 803         return ERR_PTR(safe_errno(err));
 804 }
 805
 806 /**
 807  * p9_client_zc_rpc - issue a request and wait for a response
 808  * @c: client session
 809  * @type: type of request
 810  * @uidata: destination for zero copy read
 811  * @uodata: source for zero copy write
 812  * @inlen: read buffer size
 813  * @olen: write buffer size
 814  * @hdrlen: reader header size, This is the size of response protocol data
 815  * @fmt: protocol format string (see protocol.c)
 816  *
 817  * Returns request structure (which client must free using p9_free_req)
 818  */
 819 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 820                                          struct iov_iter *uidata,
 821                                          struct iov_iter *uodata,
 822                                          int inlen, int olen, int in_hdrlen,
 823                                          const char *fmt, ...)
 824 {
 825         va_list ap;
 826         int sigpending, err;
 827         unsigned long flags;
 828         struct p9_req_t *req;
 829
 830         va_start(ap, fmt);
 831         /*
 832          * We allocate a inline protocol data of only 4k bytes.
 833          * The actual content is passed in zero-copy fashion.
 834          */
 835         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 836         va_end(ap);
 837         if (IS_ERR(req))
 838                 return req;
 839
 840         if (signal_pending(current)) {
 841                 sigpending = 1;
 842                 clear_thread_flag(TIF_SIGPENDING);
 843         } else
 844                 sigpending = 0;
 845
 846         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 847                                        inlen, olen, in_hdrlen);
 848         if (err < 0) {
 849                 if (err == -EIO)
 850                         c->status = Disconnected;
 851                 if (err != -ERESTARTSYS)
 852                         goto reterr;
 853         }
 854         if (req->status == REQ_STATUS_ERROR) {
 855                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 856                 err = req->t_err;
 857         }
 858         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 859                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 860                 sigpending = 1;
 861                 clear_thread_flag(TIF_SIGPENDING);
 862
 863                 if (c->trans_mod->cancel(c, req))
 864                         p9_client_flush(c, req);
 865
 866                 /* if we received the response anyway, don't signal error */
 867                 if (req->status == REQ_STATUS_RCVD)
 868                         err = 0;
 869         }
 870         if (sigpending) {
 871                 spin_lock_irqsave(&current->sighand->siglock, flags);
 872                 recalc_sigpending();
 873                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 874         }
 875         if (err < 0)
 876                 goto reterr;
 877
 878         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 879         trace_9p_client_res(c, type, req->rc->tag, err);
 880         if (!err)
 881                 return req;
 882 reterr:
 883         p9_free_req(c, req);
 884         return ERR_PTR(safe_errno(err));
 885 }
 886
 887 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 888 {
 889         int ret;
 890         struct p9_fid *fid;
 891         unsigned long flags;
 892
 893         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 894         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 895         if (!fid)
 896                 return ERR_PTR(-ENOMEM);
 897
 898         ret = p9_idpool_get(clnt->fidpool);
 899         if (ret < 0) {
 900                 ret = -ENOSPC;
 901                 goto error;
 902         }
 903         fid->fid = ret;
 904
 905         memset(&fid->qid, 0, sizeof(struct p9_qid));
 906         fid->mode = -1;
 907         fid->uid = current_fsuid();
 908         fid->clnt = clnt;
 909         fid->rdir = NULL;
 910         spin_lock_irqsave(&clnt->lock, flags);
 911         list_add(&fid->flist, &clnt->fidlist);
 912         spin_unlock_irqrestore(&clnt->lock, flags);
 913
 914         return fid;
 915
 916 error:
 917         kfree(fid);
 918         return ERR_PTR(ret);
 919 }
 920
 921 static void p9_fid_destroy(struct p9_fid *fid)
 922 {
 923         struct p9_client *clnt;
 924         unsigned long flags;
 925
 926         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 927         clnt = fid->clnt;
 928         p9_idpool_put(fid->fid, clnt->fidpool);
 929         spin_lock_irqsave(&clnt->lock, flags);
 930         list_del(&fid->flist);
 931         spin_unlock_irqrestore(&clnt->lock, flags);
 932         kfree(fid->rdir);
 933         kfree(fid);
 934 }
 935
 936 static int p9_client_version(struct p9_client *c)
 937 {
 938         int err = 0;
 939         struct p9_req_t *req;
 940         char *version = NULL;
 941         int msize;
 942
 943         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 944                  c->msize, c->proto_version);
 945
 946         switch (c->proto_version) {
 947         case p9_proto_2000L:
 948                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 949                                         c->msize, "9P2000.L");
 950                 break;
 951         case p9_proto_2000u:
 952                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 953                                         c->msize, "9P2000.u");
 954                 break;
 955         case p9_proto_legacy:
 956                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 957                                         c->msize, "9P2000");
 958                 break;
 959         default:
 960                 return -EINVAL;
 961         }
 962
 963         if (IS_ERR(req))
 964                 return PTR_ERR(req);
 965
 966         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 967         if (err) {
 968                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 969                 trace_9p_protocol_dump(c, req->rc);
 970                 goto error;
 971         }
 972
 973         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 974         if (!strncmp(version, "9P2000.L", 8))
 975                 c->proto_version = p9_proto_2000L;
 976         else if (!strncmp(version, "9P2000.u", 8))
 977                 c->proto_version = p9_proto_2000u;
 978         else if (!strncmp(version, "9P2000", 6))
 979                 c->proto_version = p9_proto_legacy;
 980         else {
 981                 p9_debug(P9_DEBUG_ERROR,
 982                          "server returned an unknown version: %s\n", version);
 983                 err = -EREMOTEIO;
 984                 goto error;
 985         }
 986
 987         if (msize < 4096) {
 988                 p9_debug(P9_DEBUG_ERROR,
 989                          "server returned a msize < 4096: %d\n", msize);
 990                 err = -EREMOTEIO;
 991                 goto error;
 992         }
 993         if (msize < c->msize)
 994                 c->msize = msize;
 995
 996 error:
 997         kfree(version);
 998         p9_free_req(c, req);
 999
1000         return err;
1001 }
1002
1003 struct p9_client *p9_client_create(const char *dev_name, char *options)
1004 {
1005         int err;
1006         struct p9_client *clnt;
1007         char *client_id;
1008
1009         err = 0;
1010         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1011         if (!clnt)
1012                 return ERR_PTR(-ENOMEM);
1013
1014         clnt->trans_mod = NULL;
1015         clnt->trans = NULL;
1016
1017         client_id = utsname()->nodename;
1018         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1019
1020         spin_lock_init(&clnt->lock);
1021         INIT_LIST_HEAD(&clnt->fidlist);
1022
1023         err = p9_tag_init(clnt);
1024         if (err < 0)
1025                 goto free_client;
1026
1027         err = parse_opts(options, clnt);
1028         if (err < 0)
1029                 goto destroy_tagpool;
1030
1031         if (!clnt->trans_mod)
1032                 clnt->trans_mod = v9fs_get_default_trans();
1033
1034         if (clnt->trans_mod == NULL) {
1035                 err = -EPROTONOSUPPORT;
1036                 p9_debug(P9_DEBUG_ERROR,
1037                          "No transport defined or default transport\n");
1038                 goto destroy_tagpool;
1039         }
1040
1041         clnt->fidpool = p9_idpool_create();
1042         if (IS_ERR(clnt->fidpool)) {
1043                 err = PTR_ERR(clnt->fidpool);
1044                 goto put_trans;
1045         }
1046
1047         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1048                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1049
1050         err = clnt->trans_mod->create(clnt, dev_name, options);
1051         if (err)
1052                 goto destroy_fidpool;
1053
1054         if (clnt->msize > clnt->trans_mod->maxsize)
1055                 clnt->msize = clnt->trans_mod->maxsize;
1056
1057         if (clnt->msize < 4096) {
1058                 p9_debug(P9_DEBUG_ERROR,
1059                          "Please specify a msize of at least 4k\n");
1060                 err = -EINVAL;
1061                 goto close_trans;
1062         }
1063
1064         err = p9_client_version(clnt);
1065         if (err)
1066                 goto close_trans;
1067
1068         return clnt;
1069
1070 close_trans:
1071         clnt->trans_mod->close(clnt);
1072 destroy_fidpool:
1073         p9_idpool_destroy(clnt->fidpool);
1074 put_trans:
1075         v9fs_put_trans(clnt->trans_mod);
1076 destroy_tagpool:
1077         p9_idpool_destroy(clnt->tagpool);
1078 free_client:
1079         kfree(clnt);
1080         return ERR_PTR(err);
1081 }
1082 EXPORT_SYMBOL(p9_client_create);
1083
1084 void p9_client_destroy(struct p9_client *clnt)
1085 {
1086         struct p9_fid *fid, *fidptr;
1087
1088         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1089
1090         if (clnt->trans_mod)
1091                 clnt->trans_mod->close(clnt);
1092
1093         v9fs_put_trans(clnt->trans_mod);
1094
1095         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1096                 pr_info("Found fid %d not clunked\n", fid->fid);
1097                 p9_fid_destroy(fid);
1098         }
1099
1100         if (clnt->fidpool)
1101                 p9_idpool_destroy(clnt->fidpool);
1102
1103         p9_tag_cleanup(clnt);
1104
1105         kfree(clnt);
1106 }
1107 EXPORT_SYMBOL(p9_client_destroy);
1108
1109 void p9_client_disconnect(struct p9_client *clnt)
1110 {
1111         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1112         clnt->status = Disconnected;
1113 }
1114 EXPORT_SYMBOL(p9_client_disconnect);
1115
1116 void p9_client_begin_disconnect(struct p9_client *clnt)
1117 {
1118         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1119         clnt->status = BeginDisconnect;
1120 }
1121 EXPORT_SYMBOL(p9_client_begin_disconnect);
1122
1123 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1124         char *uname, kuid_t n_uname, char *aname)
1125 {
1126         int err = 0;
1127         struct p9_req_t *req;
1128         struct p9_fid *fid;
1129         struct p9_qid qid;
1130
1131
1132         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1133                  afid ? afid->fid : -1, uname, aname);
1134         fid = p9_fid_create(clnt);
1135         if (IS_ERR(fid)) {
1136                 err = PTR_ERR(fid);
1137                 fid = NULL;
1138                 goto error;
1139         }
1140         fid->uid = n_uname;
1141
1142         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1143                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1144         if (IS_ERR(req)) {
1145                 err = PTR_ERR(req);
1146                 goto error;
1147         }
1148
1149         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1150         if (err) {
1151                 trace_9p_protocol_dump(clnt, req->rc);
1152                 p9_free_req(clnt, req);
1153                 goto error;
1154         }
1155
1156         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1157                  qid.type, (unsigned long long)qid.path, qid.version);
1158
1159         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1160
1161         p9_free_req(clnt, req);
1162         return fid;
1163
1164 error:
1165         if (fid)
1166                 p9_fid_destroy(fid);
1167         return ERR_PTR(err);
1168 }
1169 EXPORT_SYMBOL(p9_client_attach);
1170
1171 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1172                 char **wnames, int clone)
1173 {
1174         int err;
1175         struct p9_client *clnt;
1176         struct p9_fid *fid;
1177         struct p9_qid *wqids;
1178         struct p9_req_t *req;
1179         uint16_t nwqids, count;
1180
1181         err = 0;
1182         wqids = NULL;
1183         clnt = oldfid->clnt;
1184         if (clone) {
1185                 fid = p9_fid_create(clnt);
1186                 if (IS_ERR(fid)) {
1187                         err = PTR_ERR(fid);
1188                         fid = NULL;
1189                         goto error;
1190                 }
1191
1192                 fid->uid = oldfid->uid;
1193         } else
1194                 fid = oldfid;
1195
1196
1197         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1198                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1199
1200         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1201                                                                 nwname, wnames);
1202         if (IS_ERR(req)) {
1203                 err = PTR_ERR(req);
1204                 goto error;
1205         }
1206
1207         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1208         if (err) {
1209                 trace_9p_protocol_dump(clnt, req->rc);
1210                 p9_free_req(clnt, req);
1211                 goto clunk_fid;
1212         }
1213         p9_free_req(clnt, req);
1214
1215         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1216
1217         if (nwqids != nwname) {
1218                 err = -ENOENT;
1219                 goto clunk_fid;
1220         }
1221
1222         for (count = 0; count < nwqids; count++)
1223                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1224                         count, wqids[count].type,
1225                         (unsigned long long)wqids[count].path,
1226                         wqids[count].version);
1227
1228         if (nwname)
1229                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1230         else
1231                 fid->qid = oldfid->qid;
1232
1233         kfree(wqids);
1234         return fid;
1235
1236 clunk_fid:
1237         kfree(wqids);
1238         p9_client_clunk(fid);
1239         fid = NULL;
1240
1241 error:
1242         if (fid && (fid != oldfid))
1243                 p9_fid_destroy(fid);
1244
1245         return ERR_PTR(err);
1246 }
1247 EXPORT_SYMBOL(p9_client_walk);
1248
1249 int p9_client_open(struct p9_fid *fid, int mode)
1250 {
1251         int err;
1252         struct p9_client *clnt;
1253         struct p9_req_t *req;
1254         struct p9_qid qid;
1255         int iounit;
1256
1257         clnt = fid->clnt;
1258         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1259                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1260         err = 0;
1261
1262         if (fid->mode != -1)
1263                 return -EINVAL;
1264
1265         if (p9_is_proto_dotl(clnt))
1266                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1267         else
1268                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1269         if (IS_ERR(req)) {
1270                 err = PTR_ERR(req);
1271                 goto error;
1272         }
1273
1274         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1275         if (err) {
1276                 trace_9p_protocol_dump(clnt, req->rc);
1277                 goto free_and_error;
1278         }
1279
1280         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1281                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1282                 (unsigned long long)qid.path, qid.version, iounit);
1283
1284         fid->mode = mode;
1285         fid->iounit = iounit;
1286
1287 free_and_error:
1288         p9_free_req(clnt, req);
1289 error:
1290         return err;
1291 }
1292 EXPORT_SYMBOL(p9_client_open);
1293
1294 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1295                 kgid_t gid, struct p9_qid *qid)
1296 {
1297         int err = 0;
1298         struct p9_client *clnt;
1299         struct p9_req_t *req;
1300         int iounit;
1301
1302         p9_debug(P9_DEBUG_9P,
1303                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1304                         ofid->fid, name, flags, mode,
1305                         from_kgid(&init_user_ns, gid));
1306         clnt = ofid->clnt;
1307
1308         if (ofid->mode != -1)
1309                 return -EINVAL;
1310
1311         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1312                         mode, gid);
1313         if (IS_ERR(req)) {
1314                 err = PTR_ERR(req);
1315                 goto error;
1316         }
1317
1318         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1319         if (err) {
1320                 trace_9p_protocol_dump(clnt, req->rc);
1321                 goto free_and_error;
1322         }
1323
1324         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1325                         qid->type,
1326                         (unsigned long long)qid->path,
1327                         qid->version, iounit);
1328
1329         ofid->mode = mode;
1330         ofid->iounit = iounit;
1331
1332 free_and_error:
1333         p9_free_req(clnt, req);
1334 error:
1335         return err;
1336 }
1337 EXPORT_SYMBOL(p9_client_create_dotl);
1338
1339 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1340                      char *extension)
1341 {
1342         int err;
1343         struct p9_client *clnt;
1344         struct p9_req_t *req;
1345         struct p9_qid qid;
1346         int iounit;
1347
1348         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1349                                                 fid->fid, name, perm, mode);
1350         err = 0;
1351         clnt = fid->clnt;
1352
1353         if (fid->mode != -1)
1354                 return -EINVAL;
1355
1356         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1357                                 mode, extension);
1358         if (IS_ERR(req)) {
1359                 err = PTR_ERR(req);
1360                 goto error;
1361         }
1362
1363         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1364         if (err) {
1365                 trace_9p_protocol_dump(clnt, req->rc);
1366                 goto free_and_error;
1367         }
1368
1369         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1370                                 qid.type,
1371                                 (unsigned long long)qid.path,
1372                                 qid.version, iounit);
1373
1374         fid->mode = mode;
1375         fid->iounit = iounit;
1376
1377 free_and_error:
1378         p9_free_req(clnt, req);
1379 error:
1380         return err;
1381 }
1382 EXPORT_SYMBOL(p9_client_fcreate);
1383
1384 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
1385                 struct p9_qid *qid)
1386 {
1387         int err = 0;
1388         struct p9_client *clnt;
1389         struct p9_req_t *req;
1390
1391         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1392                         dfid->fid, name, symtgt);
1393         clnt = dfid->clnt;
1394
1395         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1396                         gid);
1397         if (IS_ERR(req)) {
1398                 err = PTR_ERR(req);
1399                 goto error;
1400         }
1401
1402         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1403         if (err) {
1404                 trace_9p_protocol_dump(clnt, req->rc);
1405                 goto free_and_error;
1406         }
1407
1408         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1409                         qid->type, (unsigned long long)qid->path, qid->version);
1410
1411 free_and_error:
1412         p9_free_req(clnt, req);
1413 error:
1414         return err;
1415 }
1416 EXPORT_SYMBOL(p9_client_symlink);
1417
1418 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1419 {
1420         struct p9_client *clnt;
1421         struct p9_req_t *req;
1422
1423         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1424                         dfid->fid, oldfid->fid, newname);
1425         clnt = dfid->clnt;
1426         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1427                         newname);
1428         if (IS_ERR(req))
1429                 return PTR_ERR(req);
1430
1431         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1432         p9_free_req(clnt, req);
1433         return 0;
1434 }
1435 EXPORT_SYMBOL(p9_client_link);
1436
1437 int p9_client_fsync(struct p9_fid *fid, int datasync)
1438 {
1439         int err;
1440         struct p9_client *clnt;
1441         struct p9_req_t *req;
1442
1443         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1444                         fid->fid, datasync);
1445         err = 0;
1446         clnt = fid->clnt;
1447
1448         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1449         if (IS_ERR(req)) {
1450                 err = PTR_ERR(req);
1451                 goto error;
1452         }
1453
1454         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1455
1456         p9_free_req(clnt, req);
1457
1458 error:
1459         return err;
1460 }
1461 EXPORT_SYMBOL(p9_client_fsync);
1462
1463 int p9_client_clunk(struct p9_fid *fid)
1464 {
1465         int err;
1466         struct p9_client *clnt;
1467         struct p9_req_t *req;
1468         int retries = 0;
1469
1470         if (!fid) {
1471                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1472                         __func__, task_pid_nr(current));
1473                 dump_stack();
1474                 return 0;
1475         }
1476
1477 again:
1478         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1479                                                                 retries);
1480         err = 0;
1481         clnt = fid->clnt;
1482
1483         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1484         if (IS_ERR(req)) {
1485                 err = PTR_ERR(req);
1486                 goto error;
1487         }
1488
1489         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1490
1491         p9_free_req(clnt, req);
1492 error:
1493         /*
1494          * Fid is not valid even after a failed clunk
1495          * If interrupted, retry once then give up and
1496          * leak fid until umount.
1497          */
1498         if (err == -ERESTARTSYS) {
1499                 if (retries++ == 0)
1500                         goto again;
1501         } else
1502                 p9_fid_destroy(fid);
1503         return err;
1504 }
1505 EXPORT_SYMBOL(p9_client_clunk);
1506
1507 int p9_client_remove(struct p9_fid *fid)
1508 {
1509         int err;
1510         struct p9_client *clnt;
1511         struct p9_req_t *req;
1512
1513         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1514         err = 0;
1515         clnt = fid->clnt;
1516
1517         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1518         if (IS_ERR(req)) {
1519                 err = PTR_ERR(req);
1520                 goto error;
1521         }
1522
1523         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1524
1525         p9_free_req(clnt, req);
1526 error:
1527         if (err == -ERESTARTSYS)
1528                 p9_client_clunk(fid);
1529         else
1530                 p9_fid_destroy(fid);
1531         return err;
1532 }
1533 EXPORT_SYMBOL(p9_client_remove);
1534
1535 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1536 {
1537         int err = 0;
1538         struct p9_req_t *req;
1539         struct p9_client *clnt;
1540
1541         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1542                    dfid->fid, name, flags);
1543
1544         clnt = dfid->clnt;
1545         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1546         if (IS_ERR(req)) {
1547                 err = PTR_ERR(req);
1548                 goto error;
1549         }
1550         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1551
1552         p9_free_req(clnt, req);
1553 error:
1554         return err;
1555 }
1556 EXPORT_SYMBOL(p9_client_unlinkat);
1557
1558 int
1559 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1560 {
1561         struct p9_client *clnt = fid->clnt;
1562         struct p9_req_t *req;
1563         int total = 0;
1564         *err = 0;
1565
1566         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1567                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1568
1569         while (iov_iter_count(to)) {
1570                 int count = iov_iter_count(to);
1571                 int rsize, non_zc = 0;
1572                 char *dataptr;
1573
1574                 rsize = fid->iounit;
1575                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1576                         rsize = clnt->msize - P9_IOHDRSZ;
1577
1578                 if (count < rsize)
1579                         rsize = count;
1580
1581                 /* Don't bother zerocopy for small IO (< 1024) */
1582                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1583                         /*
1584                          * response header len is 11
1585                          * PDU Header(7) + IO Size (4)
1586                          */
1587                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1588                                                0, 11, "dqd", fid->fid,
1589                                                offset, rsize);
1590                 } else {
1591                         non_zc = 1;
1592                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1593                                             rsize);
1594                 }
1595                 if (IS_ERR(req)) {
1596                         *err = PTR_ERR(req);
1597                         break;
1598                 }
1599
1600                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1601                                    "D", &count, &dataptr);
1602                 if (*err) {
1603                         trace_9p_protocol_dump(clnt, req->rc);
1604                         p9_free_req(clnt, req);
1605                         break;
1606                 }
1607                 if (rsize < count) {
1608                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1609                         count = rsize;
1610                 }
1611
1612                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1613                 if (!count) {
1614                         p9_free_req(clnt, req);
1615                         break;
1616                 }
1617
1618                 if (non_zc) {
1619                         int n = copy_to_iter(dataptr, count, to);
1620                         total += n;
1621                         offset += n;
1622                         if (n != count) {
1623                                 *err = -EFAULT;
1624                                 p9_free_req(clnt, req);
1625                                 break;
1626                         }
1627                 } else {
1628                         iov_iter_advance(to, count);
1629                         total += count;
1630                         offset += count;
1631                 }
1632                 p9_free_req(clnt, req);
1633         }
1634         return total;
1635 }
1636 EXPORT_SYMBOL(p9_client_read);
1637
1638 int
1639 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1640 {
1641         struct p9_client *clnt = fid->clnt;
1642         struct p9_req_t *req;
1643         int total = 0;
1644         *err = 0;
1645
1646         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1647                                 fid->fid, (unsigned long long) offset,
1648                                 iov_iter_count(from));
1649
1650         while (iov_iter_count(from)) {
1651                 int count = iov_iter_count(from);
1652                 int rsize = fid->iounit;
1653                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1654                         rsize = clnt->msize - P9_IOHDRSZ;
1655
1656                 if (count < rsize)
1657                         rsize = count;
1658
1659                 /* Don't bother zerocopy for small IO (< 1024) */
1660                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1661                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1662                                                rsize, P9_ZC_HDR_SZ, "dqd",
1663                                                fid->fid, offset, rsize);
1664                 } else {
1665                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1666                                                     offset, rsize, from);
1667                 }
1668                 if (IS_ERR(req)) {
1669                         *err = PTR_ERR(req);
1670                         break;
1671                 }
1672
1673                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1674                 if (*err) {
1675                         trace_9p_protocol_dump(clnt, req->rc);
1676                         p9_free_req(clnt, req);
1677                         break;
1678                 }
1679                 if (rsize < count) {
1680                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1681                         count = rsize;
1682                 }
1683
1684                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1685
1686                 p9_free_req(clnt, req);
1687                 iov_iter_advance(from, count);
1688                 total += count;
1689                 offset += count;
1690         }
1691         return total;
1692 }
1693 EXPORT_SYMBOL(p9_client_write);
1694
1695 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1696 {
1697         int err;
1698         struct p9_client *clnt;
1699         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1700         struct p9_req_t *req;
1701         u16 ignored;
1702
1703         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1704
1705         if (!ret)
1706                 return ERR_PTR(-ENOMEM);
1707
1708         err = 0;
1709         clnt = fid->clnt;
1710
1711         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1712         if (IS_ERR(req)) {
1713                 err = PTR_ERR(req);
1714                 goto error;
1715         }
1716
1717         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1718         if (err) {
1719                 trace_9p_protocol_dump(clnt, req->rc);
1720                 p9_free_req(clnt, req);
1721                 goto error;
1722         }
1723
1724         p9_debug(P9_DEBUG_9P,
1725                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1726                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1727                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1728                 "<<<    uid=%d gid=%d n_muid=%d\n",
1729                 ret->size, ret->type, ret->dev, ret->qid.type,
1730                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1731                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1732                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1733                 from_kuid(&init_user_ns, ret->n_uid),
1734                 from_kgid(&init_user_ns, ret->n_gid),
1735                 from_kuid(&init_user_ns, ret->n_muid));
1736
1737         p9_free_req(clnt, req);
1738         return ret;
1739
1740 error:
1741         kfree(ret);
1742         return ERR_PTR(err);
1743 }
1744 EXPORT_SYMBOL(p9_client_stat);
1745
1746 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1747                                                         u64 request_mask)
1748 {
1749         int err;
1750         struct p9_client *clnt;
1751         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1752                                                                 GFP_KERNEL);
1753         struct p9_req_t *req;
1754
1755         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1756                                                         fid->fid, request_mask);
1757
1758         if (!ret)
1759                 return ERR_PTR(-ENOMEM);
1760
1761         err = 0;
1762         clnt = fid->clnt;
1763
1764         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1765         if (IS_ERR(req)) {
1766                 err = PTR_ERR(req);
1767                 goto error;
1768         }
1769
1770         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1771         if (err) {
1772                 trace_9p_protocol_dump(clnt, req->rc);
1773                 p9_free_req(clnt, req);
1774                 goto error;
1775         }
1776
1777         p9_debug(P9_DEBUG_9P,
1778                 "<<< RGETATTR st_result_mask=%lld\n"
1779                 "<<< qid=%x.%llx.%x\n"
1780                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1781                 "<<< st_uid=%d st_gid=%d\n"
1782                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1783                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1784                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1785                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1786                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1787                 "<<< st_gen=%lld st_data_version=%lld",
1788                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1789                 ret->qid.version, ret->st_mode, ret->st_nlink,
1790                 from_kuid(&init_user_ns, ret->st_uid),
1791                 from_kgid(&init_user_ns, ret->st_gid),
1792                 ret->st_rdev, ret->st_size, ret->st_blksize,
1793                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1794                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1795                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1796                 ret->st_gen, ret->st_data_version);
1797
1798         p9_free_req(clnt, req);
1799         return ret;
1800
1801 error:
1802         kfree(ret);
1803         return ERR_PTR(err);
1804 }
1805 EXPORT_SYMBOL(p9_client_getattr_dotl);
1806
1807 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1808 {
1809         int ret;
1810
1811         /* NOTE: size shouldn't include its own length */
1812         /* size[2] type[2] dev[4] qid[13] */
1813         /* mode[4] atime[4] mtime[4] length[8]*/
1814         /* name[s] uid[s] gid[s] muid[s] */
1815         ret = 2+4+13+4+4+4+8+2+2+2+2;
1816
1817         if (wst->name)
1818                 ret += strlen(wst->name);
1819         if (wst->uid)
1820                 ret += strlen(wst->uid);
1821         if (wst->gid)
1822                 ret += strlen(wst->gid);
1823         if (wst->muid)
1824                 ret += strlen(wst->muid);
1825
1826         if ((proto_version == p9_proto_2000u) ||
1827                 (proto_version == p9_proto_2000L)) {
1828                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1829                 if (wst->extension)
1830                         ret += strlen(wst->extension);
1831         }
1832
1833         return ret;
1834 }
1835
1836 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1837 {
1838         int err;
1839         struct p9_req_t *req;
1840         struct p9_client *clnt;
1841
1842         err = 0;
1843         clnt = fid->clnt;
1844         wst->size = p9_client_statsize(wst, clnt->proto_version);
1845         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1846         p9_debug(P9_DEBUG_9P,
1847                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1848                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1849                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1850                 "     uid=%d gid=%d n_muid=%d\n",
1851                 wst->size, wst->type, wst->dev, wst->qid.type,
1852                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1853                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1854                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1855                 from_kuid(&init_user_ns, wst->n_uid),
1856                 from_kgid(&init_user_ns, wst->n_gid),
1857                 from_kuid(&init_user_ns, wst->n_muid));
1858
1859         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1860         if (IS_ERR(req)) {
1861                 err = PTR_ERR(req);
1862                 goto error;
1863         }
1864
1865         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1866
1867         p9_free_req(clnt, req);
1868 error:
1869         return err;
1870 }
1871 EXPORT_SYMBOL(p9_client_wstat);
1872
1873 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1874 {
1875         int err;
1876         struct p9_req_t *req;
1877         struct p9_client *clnt;
1878
1879         err = 0;
1880         clnt = fid->clnt;
1881         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1882         p9_debug(P9_DEBUG_9P,
1883                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1884                 "    atime_sec=%lld atime_nsec=%lld\n"
1885                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1886                 p9attr->valid, p9attr->mode,
1887                 from_kuid(&init_user_ns, p9attr->uid),
1888                 from_kgid(&init_user_ns, p9attr->gid),
1889                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1890                 p9attr->mtime_sec, p9attr->mtime_nsec);
1891
1892         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1893
1894         if (IS_ERR(req)) {
1895                 err = PTR_ERR(req);
1896                 goto error;
1897         }
1898         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1899         p9_free_req(clnt, req);
1900 error:
1901         return err;
1902 }
1903 EXPORT_SYMBOL(p9_client_setattr);
1904
1905 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1906 {
1907         int err;
1908         struct p9_req_t *req;
1909         struct p9_client *clnt;
1910
1911         err = 0;
1912         clnt = fid->clnt;
1913
1914         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1915
1916         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1917         if (IS_ERR(req)) {
1918                 err = PTR_ERR(req);
1919                 goto error;
1920         }
1921
1922         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1923                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1924                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1925         if (err) {
1926                 trace_9p_protocol_dump(clnt, req->rc);
1927                 p9_free_req(clnt, req);
1928                 goto error;
1929         }
1930
1931         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1932                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1933                 "fsid %llu namelen %ld\n",
1934                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1935                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1936                 sb->fsid, (long int)sb->namelen);
1937
1938         p9_free_req(clnt, req);
1939 error:
1940         return err;
1941 }
1942 EXPORT_SYMBOL(p9_client_statfs);
1943
1944 int p9_client_rename(struct p9_fid *fid,
1945                      struct p9_fid *newdirfid, const char *name)
1946 {
1947         int err;
1948         struct p9_req_t *req;
1949         struct p9_client *clnt;
1950
1951         err = 0;
1952         clnt = fid->clnt;
1953
1954         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1955                         fid->fid, newdirfid->fid, name);
1956
1957         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1958                         newdirfid->fid, name);
1959         if (IS_ERR(req)) {
1960                 err = PTR_ERR(req);
1961                 goto error;
1962         }
1963
1964         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1965
1966         p9_free_req(clnt, req);
1967 error:
1968         return err;
1969 }
1970 EXPORT_SYMBOL(p9_client_rename);
1971
1972 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1973                        struct p9_fid *newdirfid, const char *new_name)
1974 {
1975         int err;
1976         struct p9_req_t *req;
1977         struct p9_client *clnt;
1978
1979         err = 0;
1980         clnt = olddirfid->clnt;
1981
1982         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1983                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1984                    newdirfid->fid, new_name);
1985
1986         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1987                             old_name, newdirfid->fid, new_name);
1988         if (IS_ERR(req)) {
1989                 err = PTR_ERR(req);
1990                 goto error;
1991         }
1992
1993         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1994                    newdirfid->fid, new_name);
1995
1996         p9_free_req(clnt, req);
1997 error:
1998         return err;
1999 }
2000 EXPORT_SYMBOL(p9_client_renameat);
2001
2002 /*
2003  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2004  */
2005 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2006                                 const char *attr_name, u64 *attr_size)
2007 {
2008         int err;
2009         struct p9_req_t *req;
2010         struct p9_client *clnt;
2011         struct p9_fid *attr_fid;
2012
2013         err = 0;
2014         clnt = file_fid->clnt;
2015         attr_fid = p9_fid_create(clnt);
2016         if (IS_ERR(attr_fid)) {
2017                 err = PTR_ERR(attr_fid);
2018                 attr_fid = NULL;
2019                 goto error;
2020         }
2021         p9_debug(P9_DEBUG_9P,
2022                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2023                 file_fid->fid, attr_fid->fid, attr_name);
2024
2025         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2026                         file_fid->fid, attr_fid->fid, attr_name);
2027         if (IS_ERR(req)) {
2028                 err = PTR_ERR(req);
2029                 goto error;
2030         }
2031         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2032         if (err) {
2033                 trace_9p_protocol_dump(clnt, req->rc);
2034                 p9_free_req(clnt, req);
2035                 goto clunk_fid;
2036         }
2037         p9_free_req(clnt, req);
2038         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2039                 attr_fid->fid, *attr_size);
2040         return attr_fid;
2041 clunk_fid:
2042         p9_client_clunk(attr_fid);
2043         attr_fid = NULL;
2044 error:
2045         if (attr_fid && (attr_fid != file_fid))
2046                 p9_fid_destroy(attr_fid);
2047
2048         return ERR_PTR(err);
2049 }
2050 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2051
2052 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2053                         u64 attr_size, int flags)
2054 {
2055         int err;
2056         struct p9_req_t *req;
2057         struct p9_client *clnt;
2058
2059         p9_debug(P9_DEBUG_9P,
2060                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2061                 fid->fid, name, (long long)attr_size, flags);
2062         err = 0;
2063         clnt = fid->clnt;
2064         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2065                         fid->fid, name, attr_size, flags);
2066         if (IS_ERR(req)) {
2067                 err = PTR_ERR(req);
2068                 goto error;
2069         }
2070         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2071         p9_free_req(clnt, req);
2072 error:
2073         return err;
2074 }
2075 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2076
2077 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2078 {
2079         int err, rsize, non_zc = 0;
2080         struct p9_client *clnt;
2081         struct p9_req_t *req;
2082         char *dataptr;
2083         struct kvec kv = {.iov_base = data, .iov_len = count};
2084         struct iov_iter to;
2085
2086         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2087
2088         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2089                                 fid->fid, (unsigned long long) offset, count);
2090
2091         err = 0;
2092         clnt = fid->clnt;
2093
2094         rsize = fid->iounit;
2095         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2096                 rsize = clnt->msize - P9_READDIRHDRSZ;
2097
2098         if (count < rsize)
2099                 rsize = count;
2100
2101         /* Don't bother zerocopy for small IO (< 1024) */
2102         if (clnt->trans_mod->zc_request && rsize > 1024) {
2103                 /*
2104                  * response header len is 11
2105                  * PDU Header(7) + IO Size (4)
2106                  */
2107                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2108                                        11, "dqd", fid->fid, offset, rsize);
2109         } else {
2110                 non_zc = 1;
2111                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2112                                     offset, rsize);
2113         }
2114         if (IS_ERR(req)) {
2115                 err = PTR_ERR(req);
2116                 goto error;
2117         }
2118
2119         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2120         if (err) {
2121                 trace_9p_protocol_dump(clnt, req->rc);
2122                 goto free_and_error;
2123         }
2124         if (rsize < count) {
2125                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2126                 count = rsize;
2127         }
2128
2129         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2130
2131         if (non_zc)
2132                 memmove(data, dataptr, count);
2133
2134         p9_free_req(clnt, req);
2135         return count;
2136
2137 free_and_error:
2138         p9_free_req(clnt, req);
2139 error:
2140         return err;
2141 }
2142 EXPORT_SYMBOL(p9_client_readdir);
2143
2144 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2145                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2146 {
2147         int err;
2148         struct p9_client *clnt;
2149         struct p9_req_t *req;
2150
2151         err = 0;
2152         clnt = fid->clnt;
2153         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2154                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2155         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2156                 MAJOR(rdev), MINOR(rdev), gid);
2157         if (IS_ERR(req))
2158                 return PTR_ERR(req);
2159
2160         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2161         if (err) {
2162                 trace_9p_protocol_dump(clnt, req->rc);
2163                 goto error;
2164         }
2165         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2166                                 (unsigned long long)qid->path, qid->version);
2167
2168 error:
2169         p9_free_req(clnt, req);
2170         return err;
2171
2172 }
2173 EXPORT_SYMBOL(p9_client_mknod_dotl);
2174
2175 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2176                                 kgid_t gid, struct p9_qid *qid)
2177 {
2178         int err;
2179         struct p9_client *clnt;
2180         struct p9_req_t *req;
2181
2182         err = 0;
2183         clnt = fid->clnt;
2184         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2185                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2186         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2187                 gid);
2188         if (IS_ERR(req))
2189                 return PTR_ERR(req);
2190
2191         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2192         if (err) {
2193                 trace_9p_protocol_dump(clnt, req->rc);
2194                 goto error;
2195         }
2196         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2197                                 (unsigned long long)qid->path, qid->version);
2198
2199 error:
2200         p9_free_req(clnt, req);
2201         return err;
2202
2203 }
2204 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2205
2206 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2207 {
2208         int err;
2209         struct p9_client *clnt;
2210         struct p9_req_t *req;
2211
2212         err = 0;
2213         clnt = fid->clnt;
2214         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2215                         "start %lld length %lld proc_id %d client_id %s\n",
2216                         fid->fid, flock->type, flock->flags, flock->start,
2217                         flock->length, flock->proc_id, flock->client_id);
2218
2219         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2220                                 flock->flags, flock->start, flock->length,
2221                                         flock->proc_id, flock->client_id);
2222
2223         if (IS_ERR(req))
2224                 return PTR_ERR(req);
2225
2226         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2227         if (err) {
2228                 trace_9p_protocol_dump(clnt, req->rc);
2229                 goto error;
2230         }
2231         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2232 error:
2233         p9_free_req(clnt, req);
2234         return err;
2235
2236 }
2237 EXPORT_SYMBOL(p9_client_lock_dotl);
2238
2239 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2240 {
2241         int err;
2242         struct p9_client *clnt;
2243         struct p9_req_t *req;
2244
2245         err = 0;
2246         clnt = fid->clnt;
2247         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2248                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2249                 glock->start, glock->length, glock->proc_id, glock->client_id);
2250
2251         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2252                 glock->start, glock->length, glock->proc_id, glock->client_id);
2253
2254         if (IS_ERR(req))
2255                 return PTR_ERR(req);
2256
2257         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2258                         &glock->start, &glock->length, &glock->proc_id,
2259                         &glock->client_id);
2260         if (err) {
2261                 trace_9p_protocol_dump(clnt, req->rc);
2262                 goto error;
2263         }
2264         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2265                 "proc_id %d client_id %s\n", glock->type, glock->start,
2266                 glock->length, glock->proc_id, glock->client_id);
2267 error:
2268         p9_free_req(clnt, req);
2269         return err;
2270 }
2271 EXPORT_SYMBOL(p9_client_getlock_dotl);
2272
2273 int p9_client_readlink(struct p9_fid *fid, char **target)
2274 {
2275         int err;
2276         struct p9_client *clnt;
2277         struct p9_req_t *req;
2278
2279         err = 0;
2280         clnt = fid->clnt;
2281         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2282
2283         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2284         if (IS_ERR(req))
2285                 return PTR_ERR(req);
2286
2287         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2288         if (err) {
2289                 trace_9p_protocol_dump(clnt, req->rc);
2290                 goto error;
2291         }
2292         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2293 error:
2294         p9_free_req(clnt, req);
2295         return err;
2296 }
2297 EXPORT_SYMBOL(p9_client_readlink);