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) && ecode < 512)
 528                         err = -ecode;
 529
 530                 if (!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) && ecode < 512)
 615                         err = -ecode;
 616
 617                 if (!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 = kzalloc(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         fid->mode = -1;
 906         fid->uid = current_fsuid();
 907         fid->clnt = clnt;
 908         spin_lock_irqsave(&clnt->lock, flags);
 909         list_add(&fid->flist, &clnt->fidlist);
 910         spin_unlock_irqrestore(&clnt->lock, flags);
 911
 912         return fid;
 913
 914 error:
 915         kfree(fid);
 916         return ERR_PTR(ret);
 917 }
 918
 919 static void p9_fid_destroy(struct p9_fid *fid)
 920 {
 921         struct p9_client *clnt;
 922         unsigned long flags;
 923
 924         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 925         clnt = fid->clnt;
 926         p9_idpool_put(fid->fid, clnt->fidpool);
 927         spin_lock_irqsave(&clnt->lock, flags);
 928         list_del(&fid->flist);
 929         spin_unlock_irqrestore(&clnt->lock, flags);
 930         kfree(fid->rdir);
 931         kfree(fid);
 932 }
 933
 934 static int p9_client_version(struct p9_client *c)
 935 {
 936         int err = 0;
 937         struct p9_req_t *req;
 938         char *version = NULL;
 939         int msize;
 940
 941         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 942                  c->msize, c->proto_version);
 943
 944         switch (c->proto_version) {
 945         case p9_proto_2000L:
 946                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 947                                         c->msize, "9P2000.L");
 948                 break;
 949         case p9_proto_2000u:
 950                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 951                                         c->msize, "9P2000.u");
 952                 break;
 953         case p9_proto_legacy:
 954                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 955                                         c->msize, "9P2000");
 956                 break;
 957         default:
 958                 return -EINVAL;
 959         }
 960
 961         if (IS_ERR(req))
 962                 return PTR_ERR(req);
 963
 964         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 965         if (err) {
 966                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 967                 trace_9p_protocol_dump(c, req->rc);
 968                 goto error;
 969         }
 970
 971         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 972         if (!strncmp(version, "9P2000.L", 8))
 973                 c->proto_version = p9_proto_2000L;
 974         else if (!strncmp(version, "9P2000.u", 8))
 975                 c->proto_version = p9_proto_2000u;
 976         else if (!strncmp(version, "9P2000", 6))
 977                 c->proto_version = p9_proto_legacy;
 978         else {
 979                 p9_debug(P9_DEBUG_ERROR,
 980                          "server returned an unknown version: %s\n", version);
 981                 err = -EREMOTEIO;
 982                 goto error;
 983         }
 984
 985         if (msize < 4096) {
 986                 p9_debug(P9_DEBUG_ERROR,
 987                          "server returned a msize < 4096: %d\n", msize);
 988                 err = -EREMOTEIO;
 989                 goto error;
 990         }
 991         if (msize < c->msize)
 992                 c->msize = msize;
 993
 994 error:
 995         kfree(version);
 996         p9_free_req(c, req);
 997
 998         return err;
 999 }
1000
1001 struct p9_client *p9_client_create(const char *dev_name, char *options)
1002 {
1003         int err;
1004         struct p9_client *clnt;
1005         char *client_id;
1006
1007         err = 0;
1008         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1009         if (!clnt)
1010                 return ERR_PTR(-ENOMEM);
1011
1012         clnt->trans_mod = NULL;
1013         clnt->trans = NULL;
1014
1015         client_id = utsname()->nodename;
1016         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1017
1018         spin_lock_init(&clnt->lock);
1019         INIT_LIST_HEAD(&clnt->fidlist);
1020
1021         err = p9_tag_init(clnt);
1022         if (err < 0)
1023                 goto free_client;
1024
1025         err = parse_opts(options, clnt);
1026         if (err < 0)
1027                 goto destroy_tagpool;
1028
1029         if (!clnt->trans_mod)
1030                 clnt->trans_mod = v9fs_get_default_trans();
1031
1032         if (clnt->trans_mod == NULL) {
1033                 err = -EPROTONOSUPPORT;
1034                 p9_debug(P9_DEBUG_ERROR,
1035                          "No transport defined or default transport\n");
1036                 goto destroy_tagpool;
1037         }
1038
1039         clnt->fidpool = p9_idpool_create();
1040         if (IS_ERR(clnt->fidpool)) {
1041                 err = PTR_ERR(clnt->fidpool);
1042                 goto put_trans;
1043         }
1044
1045         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1046                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1047
1048         err = clnt->trans_mod->create(clnt, dev_name, options);
1049         if (err)
1050                 goto destroy_fidpool;
1051
1052         if (clnt->msize > clnt->trans_mod->maxsize)
1053                 clnt->msize = clnt->trans_mod->maxsize;
1054
1055         if (clnt->msize < 4096) {
1056                 p9_debug(P9_DEBUG_ERROR,
1057                          "Please specify a msize of at least 4k\n");
1058                 err = -EINVAL;
1059                 goto close_trans;
1060         }
1061
1062         err = p9_client_version(clnt);
1063         if (err)
1064                 goto close_trans;
1065
1066         return clnt;
1067
1068 close_trans:
1069         clnt->trans_mod->close(clnt);
1070 destroy_fidpool:
1071         p9_idpool_destroy(clnt->fidpool);
1072 put_trans:
1073         v9fs_put_trans(clnt->trans_mod);
1074 destroy_tagpool:
1075         p9_idpool_destroy(clnt->tagpool);
1076 free_client:
1077         kfree(clnt);
1078         return ERR_PTR(err);
1079 }
1080 EXPORT_SYMBOL(p9_client_create);
1081
1082 void p9_client_destroy(struct p9_client *clnt)
1083 {
1084         struct p9_fid *fid, *fidptr;
1085
1086         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1087
1088         if (clnt->trans_mod)
1089                 clnt->trans_mod->close(clnt);
1090
1091         v9fs_put_trans(clnt->trans_mod);
1092
1093         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1094                 pr_info("Found fid %d not clunked\n", fid->fid);
1095                 p9_fid_destroy(fid);
1096         }
1097
1098         if (clnt->fidpool)
1099                 p9_idpool_destroy(clnt->fidpool);
1100
1101         p9_tag_cleanup(clnt);
1102
1103         kfree(clnt);
1104 }
1105 EXPORT_SYMBOL(p9_client_destroy);
1106
1107 void p9_client_disconnect(struct p9_client *clnt)
1108 {
1109         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1110         clnt->status = Disconnected;
1111 }
1112 EXPORT_SYMBOL(p9_client_disconnect);
1113
1114 void p9_client_begin_disconnect(struct p9_client *clnt)
1115 {
1116         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1117         clnt->status = BeginDisconnect;
1118 }
1119 EXPORT_SYMBOL(p9_client_begin_disconnect);
1120
1121 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1122         char *uname, kuid_t n_uname, char *aname)
1123 {
1124         int err = 0;
1125         struct p9_req_t *req;
1126         struct p9_fid *fid;
1127         struct p9_qid qid;
1128
1129
1130         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1131                  afid ? afid->fid : -1, uname, aname);
1132         fid = p9_fid_create(clnt);
1133         if (IS_ERR(fid)) {
1134                 err = PTR_ERR(fid);
1135                 fid = NULL;
1136                 goto error;
1137         }
1138         fid->uid = n_uname;
1139
1140         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1141                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1142         if (IS_ERR(req)) {
1143                 err = PTR_ERR(req);
1144                 goto error;
1145         }
1146
1147         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1148         if (err) {
1149                 trace_9p_protocol_dump(clnt, req->rc);
1150                 p9_free_req(clnt, req);
1151                 goto error;
1152         }
1153
1154         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1155                  qid.type, (unsigned long long)qid.path, qid.version);
1156
1157         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1158
1159         p9_free_req(clnt, req);
1160         return fid;
1161
1162 error:
1163         if (fid)
1164                 p9_fid_destroy(fid);
1165         return ERR_PTR(err);
1166 }
1167 EXPORT_SYMBOL(p9_client_attach);
1168
1169 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1170                 char **wnames, int clone)
1171 {
1172         int err;
1173         struct p9_client *clnt;
1174         struct p9_fid *fid;
1175         struct p9_qid *wqids;
1176         struct p9_req_t *req;
1177         uint16_t nwqids, count;
1178
1179         err = 0;
1180         wqids = NULL;
1181         clnt = oldfid->clnt;
1182         if (clone) {
1183                 fid = p9_fid_create(clnt);
1184                 if (IS_ERR(fid)) {
1185                         err = PTR_ERR(fid);
1186                         fid = NULL;
1187                         goto error;
1188                 }
1189
1190                 fid->uid = oldfid->uid;
1191         } else
1192                 fid = oldfid;
1193
1194
1195         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1196                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1197
1198         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1199                                                                 nwname, wnames);
1200         if (IS_ERR(req)) {
1201                 err = PTR_ERR(req);
1202                 goto error;
1203         }
1204
1205         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1206         if (err) {
1207                 trace_9p_protocol_dump(clnt, req->rc);
1208                 p9_free_req(clnt, req);
1209                 goto clunk_fid;
1210         }
1211         p9_free_req(clnt, req);
1212
1213         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1214
1215         if (nwqids != nwname) {
1216                 err = -ENOENT;
1217                 goto clunk_fid;
1218         }
1219
1220         for (count = 0; count < nwqids; count++)
1221                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1222                         count, wqids[count].type,
1223                         (unsigned long long)wqids[count].path,
1224                         wqids[count].version);
1225
1226         if (nwname)
1227                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1228         else
1229                 fid->qid = oldfid->qid;
1230
1231         kfree(wqids);
1232         return fid;
1233
1234 clunk_fid:
1235         kfree(wqids);
1236         p9_client_clunk(fid);
1237         fid = NULL;
1238
1239 error:
1240         if (fid && (fid != oldfid))
1241                 p9_fid_destroy(fid);
1242
1243         return ERR_PTR(err);
1244 }
1245 EXPORT_SYMBOL(p9_client_walk);
1246
1247 int p9_client_open(struct p9_fid *fid, int mode)
1248 {
1249         int err;
1250         struct p9_client *clnt;
1251         struct p9_req_t *req;
1252         struct p9_qid qid;
1253         int iounit;
1254
1255         clnt = fid->clnt;
1256         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1257                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1258         err = 0;
1259
1260         if (fid->mode != -1)
1261                 return -EINVAL;
1262
1263         if (p9_is_proto_dotl(clnt))
1264                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1265         else
1266                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1267         if (IS_ERR(req)) {
1268                 err = PTR_ERR(req);
1269                 goto error;
1270         }
1271
1272         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1273         if (err) {
1274                 trace_9p_protocol_dump(clnt, req->rc);
1275                 goto free_and_error;
1276         }
1277
1278         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1279                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1280                 (unsigned long long)qid.path, qid.version, iounit);
1281
1282         fid->mode = mode;
1283         fid->iounit = iounit;
1284
1285 free_and_error:
1286         p9_free_req(clnt, req);
1287 error:
1288         return err;
1289 }
1290 EXPORT_SYMBOL(p9_client_open);
1291
1292 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1293                 kgid_t gid, struct p9_qid *qid)
1294 {
1295         int err = 0;
1296         struct p9_client *clnt;
1297         struct p9_req_t *req;
1298         int iounit;
1299
1300         p9_debug(P9_DEBUG_9P,
1301                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1302                         ofid->fid, name, flags, mode,
1303                         from_kgid(&init_user_ns, gid));
1304         clnt = ofid->clnt;
1305
1306         if (ofid->mode != -1)
1307                 return -EINVAL;
1308
1309         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1310                         mode, gid);
1311         if (IS_ERR(req)) {
1312                 err = PTR_ERR(req);
1313                 goto error;
1314         }
1315
1316         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1317         if (err) {
1318                 trace_9p_protocol_dump(clnt, req->rc);
1319                 goto free_and_error;
1320         }
1321
1322         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1323                         qid->type,
1324                         (unsigned long long)qid->path,
1325                         qid->version, iounit);
1326
1327         ofid->mode = mode;
1328         ofid->iounit = iounit;
1329
1330 free_and_error:
1331         p9_free_req(clnt, req);
1332 error:
1333         return err;
1334 }
1335 EXPORT_SYMBOL(p9_client_create_dotl);
1336
1337 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1338                      char *extension)
1339 {
1340         int err;
1341         struct p9_client *clnt;
1342         struct p9_req_t *req;
1343         struct p9_qid qid;
1344         int iounit;
1345
1346         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1347                                                 fid->fid, name, perm, mode);
1348         err = 0;
1349         clnt = fid->clnt;
1350
1351         if (fid->mode != -1)
1352                 return -EINVAL;
1353
1354         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1355                                 mode, extension);
1356         if (IS_ERR(req)) {
1357                 err = PTR_ERR(req);
1358                 goto error;
1359         }
1360
1361         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1362         if (err) {
1363                 trace_9p_protocol_dump(clnt, req->rc);
1364                 goto free_and_error;
1365         }
1366
1367         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1368                                 qid.type,
1369                                 (unsigned long long)qid.path,
1370                                 qid.version, iounit);
1371
1372         fid->mode = mode;
1373         fid->iounit = iounit;
1374
1375 free_and_error:
1376         p9_free_req(clnt, req);
1377 error:
1378         return err;
1379 }
1380 EXPORT_SYMBOL(p9_client_fcreate);
1381
1382 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
1383                 struct p9_qid *qid)
1384 {
1385         int err = 0;
1386         struct p9_client *clnt;
1387         struct p9_req_t *req;
1388
1389         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1390                         dfid->fid, name, symtgt);
1391         clnt = dfid->clnt;
1392
1393         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1394                         gid);
1395         if (IS_ERR(req)) {
1396                 err = PTR_ERR(req);
1397                 goto error;
1398         }
1399
1400         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1401         if (err) {
1402                 trace_9p_protocol_dump(clnt, req->rc);
1403                 goto free_and_error;
1404         }
1405
1406         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1407                         qid->type, (unsigned long long)qid->path, qid->version);
1408
1409 free_and_error:
1410         p9_free_req(clnt, req);
1411 error:
1412         return err;
1413 }
1414 EXPORT_SYMBOL(p9_client_symlink);
1415
1416 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1417 {
1418         struct p9_client *clnt;
1419         struct p9_req_t *req;
1420
1421         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1422                         dfid->fid, oldfid->fid, newname);
1423         clnt = dfid->clnt;
1424         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1425                         newname);
1426         if (IS_ERR(req))
1427                 return PTR_ERR(req);
1428
1429         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1430         p9_free_req(clnt, req);
1431         return 0;
1432 }
1433 EXPORT_SYMBOL(p9_client_link);
1434
1435 int p9_client_fsync(struct p9_fid *fid, int datasync)
1436 {
1437         int err;
1438         struct p9_client *clnt;
1439         struct p9_req_t *req;
1440
1441         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1442                         fid->fid, datasync);
1443         err = 0;
1444         clnt = fid->clnt;
1445
1446         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1447         if (IS_ERR(req)) {
1448                 err = PTR_ERR(req);
1449                 goto error;
1450         }
1451
1452         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1453
1454         p9_free_req(clnt, req);
1455
1456 error:
1457         return err;
1458 }
1459 EXPORT_SYMBOL(p9_client_fsync);
1460
1461 int p9_client_clunk(struct p9_fid *fid)
1462 {
1463         int err;
1464         struct p9_client *clnt;
1465         struct p9_req_t *req;
1466         int retries = 0;
1467
1468         if (!fid) {
1469                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1470                         __func__, task_pid_nr(current));
1471                 dump_stack();
1472                 return 0;
1473         }
1474
1475 again:
1476         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1477                                                                 retries);
1478         err = 0;
1479         clnt = fid->clnt;
1480
1481         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1482         if (IS_ERR(req)) {
1483                 err = PTR_ERR(req);
1484                 goto error;
1485         }
1486
1487         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1488
1489         p9_free_req(clnt, req);
1490 error:
1491         /*
1492          * Fid is not valid even after a failed clunk
1493          * If interrupted, retry once then give up and
1494          * leak fid until umount.
1495          */
1496         if (err == -ERESTARTSYS) {
1497                 if (retries++ == 0)
1498                         goto again;
1499         } else
1500                 p9_fid_destroy(fid);
1501         return err;
1502 }
1503 EXPORT_SYMBOL(p9_client_clunk);
1504
1505 int p9_client_remove(struct p9_fid *fid)
1506 {
1507         int err;
1508         struct p9_client *clnt;
1509         struct p9_req_t *req;
1510
1511         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1512         err = 0;
1513         clnt = fid->clnt;
1514
1515         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1516         if (IS_ERR(req)) {
1517                 err = PTR_ERR(req);
1518                 goto error;
1519         }
1520
1521         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1522
1523         p9_free_req(clnt, req);
1524 error:
1525         if (err == -ERESTARTSYS)
1526                 p9_client_clunk(fid);
1527         else
1528                 p9_fid_destroy(fid);
1529         return err;
1530 }
1531 EXPORT_SYMBOL(p9_client_remove);
1532
1533 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1534 {
1535         int err = 0;
1536         struct p9_req_t *req;
1537         struct p9_client *clnt;
1538
1539         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1540                    dfid->fid, name, flags);
1541
1542         clnt = dfid->clnt;
1543         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1544         if (IS_ERR(req)) {
1545                 err = PTR_ERR(req);
1546                 goto error;
1547         }
1548         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1549
1550         p9_free_req(clnt, req);
1551 error:
1552         return err;
1553 }
1554 EXPORT_SYMBOL(p9_client_unlinkat);
1555
1556 int
1557 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1558 {
1559         struct p9_client *clnt = fid->clnt;
1560         struct p9_req_t *req;
1561         int total = 0;
1562         *err = 0;
1563
1564         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1565                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1566
1567         while (iov_iter_count(to)) {
1568                 int count = iov_iter_count(to);
1569                 int rsize, non_zc = 0;
1570                 char *dataptr;
1571
1572                 rsize = fid->iounit;
1573                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1574                         rsize = clnt->msize - P9_IOHDRSZ;
1575
1576                 if (count < rsize)
1577                         rsize = count;
1578
1579                 /* Don't bother zerocopy for small IO (< 1024) */
1580                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1581                         /*
1582                          * response header len is 11
1583                          * PDU Header(7) + IO Size (4)
1584                          */
1585                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1586                                                0, 11, "dqd", fid->fid,
1587                                                offset, rsize);
1588                 } else {
1589                         non_zc = 1;
1590                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1591                                             rsize);
1592                 }
1593                 if (IS_ERR(req)) {
1594                         *err = PTR_ERR(req);
1595                         break;
1596                 }
1597
1598                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1599                                    "D", &count, &dataptr);
1600                 if (*err) {
1601                         trace_9p_protocol_dump(clnt, req->rc);
1602                         p9_free_req(clnt, req);
1603                         break;
1604                 }
1605                 if (rsize < count) {
1606                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1607                         count = rsize;
1608                 }
1609
1610                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1611                 if (!count) {
1612                         p9_free_req(clnt, req);
1613                         break;
1614                 }
1615
1616                 if (non_zc) {
1617                         int n = copy_to_iter(dataptr, count, to);
1618                         total += n;
1619                         offset += n;
1620                         if (n != count) {
1621                                 *err = -EFAULT;
1622                                 p9_free_req(clnt, req);
1623                                 break;
1624                         }
1625                 } else {
1626                         iov_iter_advance(to, count);
1627                         total += count;
1628                         offset += count;
1629                 }
1630                 p9_free_req(clnt, req);
1631         }
1632         return total;
1633 }
1634 EXPORT_SYMBOL(p9_client_read);
1635
1636 int
1637 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1638 {
1639         struct p9_client *clnt = fid->clnt;
1640         struct p9_req_t *req;
1641         int total = 0;
1642         *err = 0;
1643
1644         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1645                                 fid->fid, (unsigned long long) offset,
1646                                 iov_iter_count(from));
1647
1648         while (iov_iter_count(from)) {
1649                 int count = iov_iter_count(from);
1650                 int rsize = fid->iounit;
1651                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1652                         rsize = clnt->msize - P9_IOHDRSZ;
1653
1654                 if (count < rsize)
1655                         rsize = count;
1656
1657                 /* Don't bother zerocopy for small IO (< 1024) */
1658                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1659                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1660                                                rsize, P9_ZC_HDR_SZ, "dqd",
1661                                                fid->fid, offset, rsize);
1662                 } else {
1663                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1664                                                     offset, rsize, from);
1665                 }
1666                 if (IS_ERR(req)) {
1667                         *err = PTR_ERR(req);
1668                         break;
1669                 }
1670
1671                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1672                 if (*err) {
1673                         trace_9p_protocol_dump(clnt, req->rc);
1674                         p9_free_req(clnt, req);
1675                         break;
1676                 }
1677                 if (rsize < count) {
1678                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1679                         count = rsize;
1680                 }
1681
1682                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1683
1684                 p9_free_req(clnt, req);
1685                 iov_iter_advance(from, count);
1686                 total += count;
1687                 offset += count;
1688         }
1689         return total;
1690 }
1691 EXPORT_SYMBOL(p9_client_write);
1692
1693 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1694 {
1695         int err;
1696         struct p9_client *clnt;
1697         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1698         struct p9_req_t *req;
1699         u16 ignored;
1700
1701         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1702
1703         if (!ret)
1704                 return ERR_PTR(-ENOMEM);
1705
1706         err = 0;
1707         clnt = fid->clnt;
1708
1709         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1710         if (IS_ERR(req)) {
1711                 err = PTR_ERR(req);
1712                 goto error;
1713         }
1714
1715         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1716         if (err) {
1717                 trace_9p_protocol_dump(clnt, req->rc);
1718                 p9_free_req(clnt, req);
1719                 goto error;
1720         }
1721
1722         p9_debug(P9_DEBUG_9P,
1723                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1724                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1725                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1726                 "<<<    uid=%d gid=%d n_muid=%d\n",
1727                 ret->size, ret->type, ret->dev, ret->qid.type,
1728                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1729                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1730                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1731                 from_kuid(&init_user_ns, ret->n_uid),
1732                 from_kgid(&init_user_ns, ret->n_gid),
1733                 from_kuid(&init_user_ns, ret->n_muid));
1734
1735         p9_free_req(clnt, req);
1736         return ret;
1737
1738 error:
1739         kfree(ret);
1740         return ERR_PTR(err);
1741 }
1742 EXPORT_SYMBOL(p9_client_stat);
1743
1744 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1745                                                         u64 request_mask)
1746 {
1747         int err;
1748         struct p9_client *clnt;
1749         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1750                                                                 GFP_KERNEL);
1751         struct p9_req_t *req;
1752
1753         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1754                                                         fid->fid, request_mask);
1755
1756         if (!ret)
1757                 return ERR_PTR(-ENOMEM);
1758
1759         err = 0;
1760         clnt = fid->clnt;
1761
1762         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1763         if (IS_ERR(req)) {
1764                 err = PTR_ERR(req);
1765                 goto error;
1766         }
1767
1768         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1769         if (err) {
1770                 trace_9p_protocol_dump(clnt, req->rc);
1771                 p9_free_req(clnt, req);
1772                 goto error;
1773         }
1774
1775         p9_debug(P9_DEBUG_9P,
1776                 "<<< RGETATTR st_result_mask=%lld\n"
1777                 "<<< qid=%x.%llx.%x\n"
1778                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1779                 "<<< st_uid=%d st_gid=%d\n"
1780                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1781                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1782                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1783                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1784                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1785                 "<<< st_gen=%lld st_data_version=%lld",
1786                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1787                 ret->qid.version, ret->st_mode, ret->st_nlink,
1788                 from_kuid(&init_user_ns, ret->st_uid),
1789                 from_kgid(&init_user_ns, ret->st_gid),
1790                 ret->st_rdev, ret->st_size, ret->st_blksize,
1791                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1792                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1793                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1794                 ret->st_gen, ret->st_data_version);
1795
1796         p9_free_req(clnt, req);
1797         return ret;
1798
1799 error:
1800         kfree(ret);
1801         return ERR_PTR(err);
1802 }
1803 EXPORT_SYMBOL(p9_client_getattr_dotl);
1804
1805 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1806 {
1807         int ret;
1808
1809         /* NOTE: size shouldn't include its own length */
1810         /* size[2] type[2] dev[4] qid[13] */
1811         /* mode[4] atime[4] mtime[4] length[8]*/
1812         /* name[s] uid[s] gid[s] muid[s] */
1813         ret = 2+4+13+4+4+4+8+2+2+2+2;
1814
1815         if (wst->name)
1816                 ret += strlen(wst->name);
1817         if (wst->uid)
1818                 ret += strlen(wst->uid);
1819         if (wst->gid)
1820                 ret += strlen(wst->gid);
1821         if (wst->muid)
1822                 ret += strlen(wst->muid);
1823
1824         if ((proto_version == p9_proto_2000u) ||
1825                 (proto_version == p9_proto_2000L)) {
1826                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1827                 if (wst->extension)
1828                         ret += strlen(wst->extension);
1829         }
1830
1831         return ret;
1832 }
1833
1834 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1835 {
1836         int err;
1837         struct p9_req_t *req;
1838         struct p9_client *clnt;
1839
1840         err = 0;
1841         clnt = fid->clnt;
1842         wst->size = p9_client_statsize(wst, clnt->proto_version);
1843         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1844         p9_debug(P9_DEBUG_9P,
1845                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1846                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1847                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1848                 "     uid=%d gid=%d n_muid=%d\n",
1849                 wst->size, wst->type, wst->dev, wst->qid.type,
1850                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1851                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1852                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1853                 from_kuid(&init_user_ns, wst->n_uid),
1854                 from_kgid(&init_user_ns, wst->n_gid),
1855                 from_kuid(&init_user_ns, wst->n_muid));
1856
1857         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1858         if (IS_ERR(req)) {
1859                 err = PTR_ERR(req);
1860                 goto error;
1861         }
1862
1863         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1864
1865         p9_free_req(clnt, req);
1866 error:
1867         return err;
1868 }
1869 EXPORT_SYMBOL(p9_client_wstat);
1870
1871 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1872 {
1873         int err;
1874         struct p9_req_t *req;
1875         struct p9_client *clnt;
1876
1877         err = 0;
1878         clnt = fid->clnt;
1879         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1880         p9_debug(P9_DEBUG_9P,
1881                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1882                 "    atime_sec=%lld atime_nsec=%lld\n"
1883                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1884                 p9attr->valid, p9attr->mode,
1885                 from_kuid(&init_user_ns, p9attr->uid),
1886                 from_kgid(&init_user_ns, p9attr->gid),
1887                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1888                 p9attr->mtime_sec, p9attr->mtime_nsec);
1889
1890         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1891
1892         if (IS_ERR(req)) {
1893                 err = PTR_ERR(req);
1894                 goto error;
1895         }
1896         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1897         p9_free_req(clnt, req);
1898 error:
1899         return err;
1900 }
1901 EXPORT_SYMBOL(p9_client_setattr);
1902
1903 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1904 {
1905         int err;
1906         struct p9_req_t *req;
1907         struct p9_client *clnt;
1908
1909         err = 0;
1910         clnt = fid->clnt;
1911
1912         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1913
1914         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1915         if (IS_ERR(req)) {
1916                 err = PTR_ERR(req);
1917                 goto error;
1918         }
1919
1920         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1921                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1922                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1923         if (err) {
1924                 trace_9p_protocol_dump(clnt, req->rc);
1925                 p9_free_req(clnt, req);
1926                 goto error;
1927         }
1928
1929         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1930                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1931                 "fsid %llu namelen %ld\n",
1932                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1933                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1934                 sb->fsid, (long int)sb->namelen);
1935
1936         p9_free_req(clnt, req);
1937 error:
1938         return err;
1939 }
1940 EXPORT_SYMBOL(p9_client_statfs);
1941
1942 int p9_client_rename(struct p9_fid *fid,
1943                      struct p9_fid *newdirfid, const char *name)
1944 {
1945         int err;
1946         struct p9_req_t *req;
1947         struct p9_client *clnt;
1948
1949         err = 0;
1950         clnt = fid->clnt;
1951
1952         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1953                         fid->fid, newdirfid->fid, name);
1954
1955         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1956                         newdirfid->fid, name);
1957         if (IS_ERR(req)) {
1958                 err = PTR_ERR(req);
1959                 goto error;
1960         }
1961
1962         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1963
1964         p9_free_req(clnt, req);
1965 error:
1966         return err;
1967 }
1968 EXPORT_SYMBOL(p9_client_rename);
1969
1970 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1971                        struct p9_fid *newdirfid, const char *new_name)
1972 {
1973         int err;
1974         struct p9_req_t *req;
1975         struct p9_client *clnt;
1976
1977         err = 0;
1978         clnt = olddirfid->clnt;
1979
1980         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1981                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1982                    newdirfid->fid, new_name);
1983
1984         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1985                             old_name, newdirfid->fid, new_name);
1986         if (IS_ERR(req)) {
1987                 err = PTR_ERR(req);
1988                 goto error;
1989         }
1990
1991         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1992                    newdirfid->fid, new_name);
1993
1994         p9_free_req(clnt, req);
1995 error:
1996         return err;
1997 }
1998 EXPORT_SYMBOL(p9_client_renameat);
1999
2000 /*
2001  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2002  */
2003 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2004                                 const char *attr_name, u64 *attr_size)
2005 {
2006         int err;
2007         struct p9_req_t *req;
2008         struct p9_client *clnt;
2009         struct p9_fid *attr_fid;
2010
2011         err = 0;
2012         clnt = file_fid->clnt;
2013         attr_fid = p9_fid_create(clnt);
2014         if (IS_ERR(attr_fid)) {
2015                 err = PTR_ERR(attr_fid);
2016                 attr_fid = NULL;
2017                 goto error;
2018         }
2019         p9_debug(P9_DEBUG_9P,
2020                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2021                 file_fid->fid, attr_fid->fid, attr_name);
2022
2023         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2024                         file_fid->fid, attr_fid->fid, attr_name);
2025         if (IS_ERR(req)) {
2026                 err = PTR_ERR(req);
2027                 goto error;
2028         }
2029         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2030         if (err) {
2031                 trace_9p_protocol_dump(clnt, req->rc);
2032                 p9_free_req(clnt, req);
2033                 goto clunk_fid;
2034         }
2035         p9_free_req(clnt, req);
2036         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2037                 attr_fid->fid, *attr_size);
2038         return attr_fid;
2039 clunk_fid:
2040         p9_client_clunk(attr_fid);
2041         attr_fid = NULL;
2042 error:
2043         if (attr_fid && (attr_fid != file_fid))
2044                 p9_fid_destroy(attr_fid);
2045
2046         return ERR_PTR(err);
2047 }
2048 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2049
2050 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2051                         u64 attr_size, int flags)
2052 {
2053         int err;
2054         struct p9_req_t *req;
2055         struct p9_client *clnt;
2056
2057         p9_debug(P9_DEBUG_9P,
2058                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2059                 fid->fid, name, (long long)attr_size, flags);
2060         err = 0;
2061         clnt = fid->clnt;
2062         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2063                         fid->fid, name, attr_size, flags);
2064         if (IS_ERR(req)) {
2065                 err = PTR_ERR(req);
2066                 goto error;
2067         }
2068         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2069         p9_free_req(clnt, req);
2070 error:
2071         return err;
2072 }
2073 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2074
2075 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2076 {
2077         int err, rsize, non_zc = 0;
2078         struct p9_client *clnt;
2079         struct p9_req_t *req;
2080         char *dataptr;
2081         struct kvec kv = {.iov_base = data, .iov_len = count};
2082         struct iov_iter to;
2083
2084         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2085
2086         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2087                                 fid->fid, (unsigned long long) offset, count);
2088
2089         err = 0;
2090         clnt = fid->clnt;
2091
2092         rsize = fid->iounit;
2093         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2094                 rsize = clnt->msize - P9_READDIRHDRSZ;
2095
2096         if (count < rsize)
2097                 rsize = count;
2098
2099         /* Don't bother zerocopy for small IO (< 1024) */
2100         if (clnt->trans_mod->zc_request && rsize > 1024) {
2101                 /*
2102                  * response header len is 11
2103                  * PDU Header(7) + IO Size (4)
2104                  */
2105                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2106                                        11, "dqd", fid->fid, offset, rsize);
2107         } else {
2108                 non_zc = 1;
2109                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2110                                     offset, rsize);
2111         }
2112         if (IS_ERR(req)) {
2113                 err = PTR_ERR(req);
2114                 goto error;
2115         }
2116
2117         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2118         if (err) {
2119                 trace_9p_protocol_dump(clnt, req->rc);
2120                 goto free_and_error;
2121         }
2122         if (rsize < count) {
2123                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2124                 count = rsize;
2125         }
2126
2127         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2128
2129         if (non_zc)
2130                 memmove(data, dataptr, count);
2131
2132         p9_free_req(clnt, req);
2133         return count;
2134
2135 free_and_error:
2136         p9_free_req(clnt, req);
2137 error:
2138         return err;
2139 }
2140 EXPORT_SYMBOL(p9_client_readdir);
2141
2142 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2143                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2144 {
2145         int err;
2146         struct p9_client *clnt;
2147         struct p9_req_t *req;
2148
2149         err = 0;
2150         clnt = fid->clnt;
2151         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2152                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2153         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2154                 MAJOR(rdev), MINOR(rdev), gid);
2155         if (IS_ERR(req))
2156                 return PTR_ERR(req);
2157
2158         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2159         if (err) {
2160                 trace_9p_protocol_dump(clnt, req->rc);
2161                 goto error;
2162         }
2163         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2164                                 (unsigned long long)qid->path, qid->version);
2165
2166 error:
2167         p9_free_req(clnt, req);
2168         return err;
2169
2170 }
2171 EXPORT_SYMBOL(p9_client_mknod_dotl);
2172
2173 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2174                                 kgid_t gid, struct p9_qid *qid)
2175 {
2176         int err;
2177         struct p9_client *clnt;
2178         struct p9_req_t *req;
2179
2180         err = 0;
2181         clnt = fid->clnt;
2182         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2183                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2184         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2185                 gid);
2186         if (IS_ERR(req))
2187                 return PTR_ERR(req);
2188
2189         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2190         if (err) {
2191                 trace_9p_protocol_dump(clnt, req->rc);
2192                 goto error;
2193         }
2194         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2195                                 (unsigned long long)qid->path, qid->version);
2196
2197 error:
2198         p9_free_req(clnt, req);
2199         return err;
2200
2201 }
2202 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2203
2204 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2205 {
2206         int err;
2207         struct p9_client *clnt;
2208         struct p9_req_t *req;
2209
2210         err = 0;
2211         clnt = fid->clnt;
2212         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2213                         "start %lld length %lld proc_id %d client_id %s\n",
2214                         fid->fid, flock->type, flock->flags, flock->start,
2215                         flock->length, flock->proc_id, flock->client_id);
2216
2217         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2218                                 flock->flags, flock->start, flock->length,
2219                                         flock->proc_id, flock->client_id);
2220
2221         if (IS_ERR(req))
2222                 return PTR_ERR(req);
2223
2224         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2225         if (err) {
2226                 trace_9p_protocol_dump(clnt, req->rc);
2227                 goto error;
2228         }
2229         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2230 error:
2231         p9_free_req(clnt, req);
2232         return err;
2233
2234 }
2235 EXPORT_SYMBOL(p9_client_lock_dotl);
2236
2237 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2238 {
2239         int err;
2240         struct p9_client *clnt;
2241         struct p9_req_t *req;
2242
2243         err = 0;
2244         clnt = fid->clnt;
2245         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2246                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2247                 glock->start, glock->length, glock->proc_id, glock->client_id);
2248
2249         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2250                 glock->start, glock->length, glock->proc_id, glock->client_id);
2251
2252         if (IS_ERR(req))
2253                 return PTR_ERR(req);
2254
2255         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2256                         &glock->start, &glock->length, &glock->proc_id,
2257                         &glock->client_id);
2258         if (err) {
2259                 trace_9p_protocol_dump(clnt, req->rc);
2260                 goto error;
2261         }
2262         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2263                 "proc_id %d client_id %s\n", glock->type, glock->start,
2264                 glock->length, glock->proc_id, glock->client_id);
2265 error:
2266         p9_free_req(clnt, req);
2267         return err;
2268 }
2269 EXPORT_SYMBOL(p9_client_getlock_dotl);
2270
2271 int p9_client_readlink(struct p9_fid *fid, char **target)
2272 {
2273         int err;
2274         struct p9_client *clnt;
2275         struct p9_req_t *req;
2276
2277         err = 0;
2278         clnt = fid->clnt;
2279         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2280
2281         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2282         if (IS_ERR(req))
2283                 return PTR_ERR(req);
2284
2285         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2286         if (err) {
2287                 trace_9p_protocol_dump(clnt, req->rc);
2288                 goto error;
2289         }
2290         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2291 error:
2292         p9_free_req(clnt, req);
2293         return err;
2294 }
2295 EXPORT_SYMBOL(p9_client_readlink);