net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/poll.h>
  32 #include <linux/idr.h>
  33 #include <linux/mutex.h>
  34 #include <linux/slab.h>
  35 #include <linux/sched/signal.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/uio.h>
  38 #include <net/9p/9p.h>
  39 #include <linux/parser.h>
  40 #include <linux/seq_file.h>
  41 #include <net/9p/client.h>
  42 #include <net/9p/transport.h>
  43 #include "protocol.h"
  44
  45 #define CREATE_TRACE_POINTS
  46 #include <trace/events/9p.h>
  47
  48 /*
  49   * Client Option Parsing (code inspired by NFS code)
  50   *  - a little lazy - parse all client options
  51   */
  52
  53 enum {
  54         Opt_msize,
  55         Opt_trans,
  56         Opt_legacy,
  57         Opt_version,
  58         Opt_err,
  59 };
  60
  61 static const match_table_t tokens = {
  62         {Opt_msize, "msize=%u"},
  63         {Opt_legacy, "noextend"},
  64         {Opt_trans, "trans=%s"},
  65         {Opt_version, "version=%s"},
  66         {Opt_err, NULL},
  67 };
  68
  69 inline int p9_is_proto_dotl(struct p9_client *clnt)
  70 {
  71         return clnt->proto_version == p9_proto_2000L;
  72 }
  73 EXPORT_SYMBOL(p9_is_proto_dotl);
  74
  75 inline int p9_is_proto_dotu(struct p9_client *clnt)
  76 {
  77         return clnt->proto_version == p9_proto_2000u;
  78 }
  79 EXPORT_SYMBOL(p9_is_proto_dotu);
  80
  81 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
  82 {
  83         if (clnt->msize != 8192)
  84                 seq_printf(m, ",msize=%u", clnt->msize);
  85         seq_printf(m, ",trans=%s", clnt->trans_mod->name);
  86
  87         switch (clnt->proto_version) {
  88         case p9_proto_legacy:
  89                 seq_puts(m, ",noextend");
  90                 break;
  91         case p9_proto_2000u:
  92                 seq_puts(m, ",version=9p2000.u");
  93                 break;
  94         case p9_proto_2000L:
  95                 /* Default */
  96                 break;
  97         }
  98
  99         if (clnt->trans_mod->show_options)
 100                 return clnt->trans_mod->show_options(m, clnt);
 101         return 0;
 102 }
 103 EXPORT_SYMBOL(p9_show_client_options);
 104
 105 /*
 106  * Some error codes are taken directly from the server replies,
 107  * make sure they are valid.
 108  */
 109 static int safe_errno(int err)
 110 {
 111         if ((err > 0) || (err < -MAX_ERRNO)) {
 112                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
 113                 return -EPROTO;
 114         }
 115         return err;
 116 }
 117
 118
 119 /* Interpret mount option for protocol version */
 120 static int get_protocol_version(char *s)
 121 {
 122         int version = -EINVAL;
 123
 124         if (!strcmp(s, "9p2000")) {
 125                 version = p9_proto_legacy;
 126                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
 127         } else if (!strcmp(s, "9p2000.u")) {
 128                 version = p9_proto_2000u;
 129                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
 130         } else if (!strcmp(s, "9p2000.L")) {
 131                 version = p9_proto_2000L;
 132                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
 133         } else
 134                 pr_info("Unknown protocol version %s\n", s);
 135
 136         return version;
 137 }
 138
 139 /**
 140  * parse_options - parse mount options into client structure
 141  * @opts: options string passed from mount
 142  * @clnt: existing v9fs client information
 143  *
 144  * Return 0 upon success, -ERRNO upon failure
 145  */
 146
 147 static int parse_opts(char *opts, struct p9_client *clnt)
 148 {
 149         char *options, *tmp_options;
 150         char *p;
 151         substring_t args[MAX_OPT_ARGS];
 152         int option;
 153         char *s;
 154         int ret = 0;
 155
 156         clnt->proto_version = p9_proto_2000L;
 157         clnt->msize = 8192;
 158
 159         if (!opts)
 160                 return 0;
 161
 162         tmp_options = kstrdup(opts, GFP_KERNEL);
 163         if (!tmp_options) {
 164                 p9_debug(P9_DEBUG_ERROR,
 165                          "failed to allocate copy of option string\n");
 166                 return -ENOMEM;
 167         }
 168         options = tmp_options;
 169
 170         while ((p = strsep(&options, ",")) != NULL) {
 171                 int token, r;
 172                 if (!*p)
 173                         continue;
 174                 token = match_token(p, tokens, args);
 175                 switch (token) {
 176                 case Opt_msize:
 177                         r = match_int(&args[0], &option);
 178                         if (r < 0) {
 179                                 p9_debug(P9_DEBUG_ERROR,
 180                                          "integer field, but no integer?\n");
 181                                 ret = r;
 182                                 continue;
 183                         }
 184                         clnt->msize = option;
 185                         break;
 186                 case Opt_trans:
 187                         s = match_strdup(&args[0]);
 188                         if (!s) {
 189                                 ret = -ENOMEM;
 190                                 p9_debug(P9_DEBUG_ERROR,
 191                                          "problem allocating copy of trans arg\n");
 192                                 goto free_and_return;
 193                         }
 194
 195                         v9fs_put_trans(clnt->trans_mod);
 196                         clnt->trans_mod = v9fs_get_trans_by_name(s);
 197                         if (clnt->trans_mod == NULL) {
 198                                 pr_info("Could not find request transport: %s\n",
 199                                         s);
 200                                 ret = -EINVAL;
 201                         }
 202                         kfree(s);
 203                         break;
 204                 case Opt_legacy:
 205                         clnt->proto_version = p9_proto_legacy;
 206                         break;
 207                 case Opt_version:
 208                         s = match_strdup(&args[0]);
 209                         if (!s) {
 210                                 ret = -ENOMEM;
 211                                 p9_debug(P9_DEBUG_ERROR,
 212                                          "problem allocating copy of version arg\n");
 213                                 goto free_and_return;
 214                         }
 215                         r = get_protocol_version(s);
 216                         if (r < 0)
 217                                 ret = r;
 218                         else
 219                                 clnt->proto_version = r;
 220                         kfree(s);
 221                         break;
 222                 default:
 223                         continue;
 224                 }
 225         }
 226
 227 free_and_return:
 228         if (ret)
 229                 v9fs_put_trans(clnt->trans_mod);
 230         kfree(tmp_options);
 231         return ret;
 232 }
 233
 234 static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
 235 {
 236         struct p9_fcall *fc;
 237         fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
 238         if (!fc)
 239                 return NULL;
 240         fc->capacity = alloc_msize;
 241         fc->sdata = (char *) fc + sizeof(struct p9_fcall);
 242         return fc;
 243 }
 244
 245 /**
 246  * p9_tag_alloc - lookup/allocate a request by tag
 247  * @c: client session to lookup tag within
 248  * @tag: numeric id for transaction
 249  *
 250  * this is a simple array lookup, but will grow the
 251  * request_slots as necessary to accommodate transaction
 252  * ids which did not previously have a slot.
 253  *
 254  * this code relies on the client spinlock to manage locks, its
 255  * possible we should switch to something else, but I'd rather
 256  * stick with something low-overhead for the common case.
 257  *
 258  */
 259
 260 static struct p9_req_t *
 261 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
 262 {
 263         unsigned long flags;
 264         int row, col;
 265         struct p9_req_t *req;
 266         int alloc_msize = min(c->msize, max_size);
 267
 268         /* This looks up the original request by tag so we know which
 269          * buffer to read the data into */
 270         tag++;
 271
 272         if (tag >= c->max_tag) {
 273                 spin_lock_irqsave(&c->lock, flags);
 274                 /* check again since original check was outside of lock */
 275                 while (tag >= c->max_tag) {
 276                         row = (tag / P9_ROW_MAXTAG);
 277                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 278                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 279
 280                         if (!c->reqs[row]) {
 281                                 pr_err("Couldn't grow tag array\n");
 282                                 spin_unlock_irqrestore(&c->lock, flags);
 283                                 return ERR_PTR(-ENOMEM);
 284                         }
 285                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 286                                 req = &c->reqs[row][col];
 287                                 req->status = REQ_STATUS_IDLE;
 288                                 init_waitqueue_head(&req->wq);
 289                         }
 290                         c->max_tag += P9_ROW_MAXTAG;
 291                 }
 292                 spin_unlock_irqrestore(&c->lock, flags);
 293         }
 294         row = tag / P9_ROW_MAXTAG;
 295         col = tag % P9_ROW_MAXTAG;
 296
 297         req = &c->reqs[row][col];
 298         if (!req->tc)
 299                 req->tc = p9_fcall_alloc(alloc_msize);
 300         if (!req->rc)
 301                 req->rc = p9_fcall_alloc(alloc_msize);
 302         if (!req->tc || !req->rc)
 303                 goto grow_failed;
 304
 305         p9pdu_reset(req->tc);
 306         p9pdu_reset(req->rc);
 307
 308         req->tc->tag = tag-1;
 309         req->status = REQ_STATUS_ALLOC;
 310
 311         return req;
 312
 313 grow_failed:
 314         pr_err("Couldn't grow tag array\n");
 315         kfree(req->tc);
 316         kfree(req->rc);
 317         req->tc = req->rc = NULL;
 318         return ERR_PTR(-ENOMEM);
 319 }
 320
 321 /**
 322  * p9_tag_lookup - lookup a request by tag
 323  * @c: client session to lookup tag within
 324  * @tag: numeric id for transaction
 325  *
 326  */
 327
 328 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 329 {
 330         int row, col;
 331
 332         /* This looks up the original request by tag so we know which
 333          * buffer to read the data into */
 334         tag++;
 335
 336         if(tag >= c->max_tag)
 337                 return NULL;
 338
 339         row = tag / P9_ROW_MAXTAG;
 340         col = tag % P9_ROW_MAXTAG;
 341
 342         return &c->reqs[row][col];
 343 }
 344 EXPORT_SYMBOL(p9_tag_lookup);
 345
 346 /**
 347  * p9_tag_init - setup tags structure and contents
 348  * @c:  v9fs client struct
 349  *
 350  * This initializes the tags structure for each client instance.
 351  *
 352  */
 353
 354 static int p9_tag_init(struct p9_client *c)
 355 {
 356         int err = 0;
 357
 358         c->tagpool = p9_idpool_create();
 359         if (IS_ERR(c->tagpool)) {
 360                 err = PTR_ERR(c->tagpool);
 361                 goto error;
 362         }
 363         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
 364         if (err < 0) {
 365                 p9_idpool_destroy(c->tagpool);
 366                 goto error;
 367         }
 368         c->max_tag = 0;
 369 error:
 370         return err;
 371 }
 372
 373 /**
 374  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 375  * @c:  v9fs client struct
 376  *
 377  * This frees resources associated with the tags structure
 378  *
 379  */
 380 static void p9_tag_cleanup(struct p9_client *c)
 381 {
 382         int row, col;
 383
 384         /* check to insure all requests are idle */
 385         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 386                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 387                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 388                                 p9_debug(P9_DEBUG_MUX,
 389                                          "Attempting to cleanup non-free tag %d,%d\n",
 390                                          row, col);
 391                                 /* TODO: delay execution of cleanup */
 392                                 return;
 393                         }
 394                 }
 395         }
 396
 397         if (c->tagpool) {
 398                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
 399                 p9_idpool_destroy(c->tagpool);
 400         }
 401
 402         /* free requests associated with tags */
 403         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 404                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 405                         kfree(c->reqs[row][col].tc);
 406                         kfree(c->reqs[row][col].rc);
 407                 }
 408                 kfree(c->reqs[row]);
 409         }
 410         c->max_tag = 0;
 411 }
 412
 413 /**
 414  * p9_free_req - free a request and clean-up as necessary
 415  * c: client state
 416  * r: request to release
 417  *
 418  */
 419
 420 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 421 {
 422         int tag = r->tc->tag;
 423         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 424
 425         r->status = REQ_STATUS_IDLE;
 426         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 427                 p9_idpool_put(tag, c->tagpool);
 428 }
 429
 430 /**
 431  * p9_client_cb - call back from transport to client
 432  * c: client state
 433  * req: request received
 434  *
 435  */
 436 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 437 {
 438         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 439
 440         /*
 441          * This barrier is needed to make sure any change made to req before
 442          * the status change is visible to another thread
 443          */
 444         smp_wmb();
 445         req->status = status;
 446
 447         wake_up(&req->wq);
 448         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 449 }
 450 EXPORT_SYMBOL(p9_client_cb);
 451
 452 /**
 453  * p9_parse_header - parse header arguments out of a packet
 454  * @pdu: packet to parse
 455  * @size: size of packet
 456  * @type: type of request
 457  * @tag: tag of packet
 458  * @rewind: set if we need to rewind offset afterwards
 459  */
 460
 461 int
 462 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 463                                                                 int rewind)
 464 {
 465         int8_t r_type;
 466         int16_t r_tag;
 467         int32_t r_size;
 468         int offset = pdu->offset;
 469         int err;
 470
 471         pdu->offset = 0;
 472         if (pdu->size == 0)
 473                 pdu->size = 7;
 474
 475         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 476         if (err)
 477                 goto rewind_and_exit;
 478
 479         pdu->size = r_size;
 480         pdu->id = r_type;
 481         pdu->tag = r_tag;
 482
 483         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 484                  pdu->size, pdu->id, pdu->tag);
 485
 486         if (type)
 487                 *type = r_type;
 488         if (tag)
 489                 *tag = r_tag;
 490         if (size)
 491                 *size = r_size;
 492
 493
 494 rewind_and_exit:
 495         if (rewind)
 496                 pdu->offset = offset;
 497         return err;
 498 }
 499 EXPORT_SYMBOL(p9_parse_header);
 500
 501 /**
 502  * p9_check_errors - check 9p packet for error return and process it
 503  * @c: current client instance
 504  * @req: request to parse and check for error conditions
 505  *
 506  * returns error code if one is discovered, otherwise returns 0
 507  *
 508  * this will have to be more complicated if we have multiple
 509  * error packet types
 510  */
 511
 512 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 513 {
 514         int8_t type;
 515         int err;
 516         int ecode;
 517
 518         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 519         /*
 520          * dump the response from server
 521          * This should be after check errors which poplulate pdu_fcall.
 522          */
 523         trace_9p_protocol_dump(c, req->rc);
 524         if (err) {
 525                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 526                 return err;
 527         }
 528         if (type != P9_RERROR && type != P9_RLERROR)
 529                 return 0;
 530
 531         if (!p9_is_proto_dotl(c)) {
 532                 char *ename;
 533                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 534                                   &ename, &ecode);
 535                 if (err)
 536                         goto out_err;
 537
 538                 if (p9_is_proto_dotu(c) && ecode < 512)
 539                         err = -ecode;
 540
 541                 if (!err) {
 542                         err = p9_errstr2errno(ename, strlen(ename));
 543
 544                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 545                                  -ecode, ename);
 546                 }
 547                 kfree(ename);
 548         } else {
 549                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 550                 err = -ecode;
 551
 552                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 553         }
 554
 555         return err;
 556
 557 out_err:
 558         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 559
 560         return err;
 561 }
 562
 563 /**
 564  * p9_check_zc_errors - check 9p packet for error return and process it
 565  * @c: current client instance
 566  * @req: request to parse and check for error conditions
 567  * @in_hdrlen: Size of response protocol buffer.
 568  *
 569  * returns error code if one is discovered, otherwise returns 0
 570  *
 571  * this will have to be more complicated if we have multiple
 572  * error packet types
 573  */
 574
 575 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 576                               struct iov_iter *uidata, int in_hdrlen)
 577 {
 578         int err;
 579         int ecode;
 580         int8_t type;
 581         char *ename = NULL;
 582
 583         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 584         /*
 585          * dump the response from server
 586          * This should be after parse_header which poplulate pdu_fcall.
 587          */
 588         trace_9p_protocol_dump(c, req->rc);
 589         if (err) {
 590                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 591                 return err;
 592         }
 593
 594         if (type != P9_RERROR && type != P9_RLERROR)
 595                 return 0;
 596
 597         if (!p9_is_proto_dotl(c)) {
 598                 /* Error is reported in string format */
 599                 int len;
 600                 /* 7 = header size for RERROR; */
 601                 int inline_len = in_hdrlen - 7;
 602
 603                 len =  req->rc->size - req->rc->offset;
 604                 if (len > (P9_ZC_HDR_SZ - 7)) {
 605                         err = -EFAULT;
 606                         goto out_err;
 607                 }
 608
 609                 ename = &req->rc->sdata[req->rc->offset];
 610                 if (len > inline_len) {
 611                         /* We have error in external buffer */
 612                         if (!copy_from_iter_full(ename + inline_len,
 613                                              len - inline_len, uidata)) {
 614                                 err = -EFAULT;
 615                                 goto out_err;
 616                         }
 617                 }
 618                 ename = NULL;
 619                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 620                                   &ename, &ecode);
 621                 if (err)
 622                         goto out_err;
 623
 624                 if (p9_is_proto_dotu(c) && ecode < 512)
 625                         err = -ecode;
 626
 627                 if (!err) {
 628                         err = p9_errstr2errno(ename, strlen(ename));
 629
 630                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 631                                  -ecode, ename);
 632                 }
 633                 kfree(ename);
 634         } else {
 635                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 636                 err = -ecode;
 637
 638                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 639         }
 640         return err;
 641
 642 out_err:
 643         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 644         return err;
 645 }
 646
 647 static struct p9_req_t *
 648 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 649
 650 /**
 651  * p9_client_flush - flush (cancel) a request
 652  * @c: client state
 653  * @oldreq: request to cancel
 654  *
 655  * This sents a flush for a particular request and links
 656  * the flush request to the original request.  The current
 657  * code only supports a single flush request although the protocol
 658  * allows for multiple flush requests to be sent for a single request.
 659  *
 660  */
 661
 662 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 663 {
 664         struct p9_req_t *req;
 665         int16_t oldtag;
 666         int err;
 667
 668         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 669         if (err)
 670                 return err;
 671
 672         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 673
 674         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 675         if (IS_ERR(req))
 676                 return PTR_ERR(req);
 677
 678         /*
 679          * if we haven't received a response for oldreq,
 680          * remove it from the list
 681          */
 682         if (oldreq->status == REQ_STATUS_SENT)
 683                 if (c->trans_mod->cancelled)
 684                         c->trans_mod->cancelled(c, oldreq);
 685
 686         p9_free_req(c, req);
 687         return 0;
 688 }
 689
 690 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 691                                               int8_t type, int req_size,
 692                                               const char *fmt, va_list ap)
 693 {
 694         int tag, err;
 695         struct p9_req_t *req;
 696
 697         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 698
 699         /* we allow for any status other than disconnected */
 700         if (c->status == Disconnected)
 701                 return ERR_PTR(-EIO);
 702
 703         /* if status is begin_disconnected we allow only clunk request */
 704         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 705                 return ERR_PTR(-EIO);
 706
 707         tag = P9_NOTAG;
 708         if (type != P9_TVERSION) {
 709                 tag = p9_idpool_get(c->tagpool);
 710                 if (tag < 0)
 711                         return ERR_PTR(-ENOMEM);
 712         }
 713
 714         req = p9_tag_alloc(c, tag, req_size);
 715         if (IS_ERR(req))
 716                 return req;
 717
 718         /* marshall the data */
 719         p9pdu_prepare(req->tc, tag, type);
 720         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 721         if (err)
 722                 goto reterr;
 723         p9pdu_finalize(c, req->tc);
 724         trace_9p_client_req(c, type, tag);
 725         return req;
 726 reterr:
 727         p9_free_req(c, req);
 728         return ERR_PTR(err);
 729 }
 730
 731 /**
 732  * p9_client_rpc - issue a request and wait for a response
 733  * @c: client session
 734  * @type: type of request
 735  * @fmt: protocol format string (see protocol.c)
 736  *
 737  * Returns request structure (which client must free using p9_free_req)
 738  */
 739
 740 static struct p9_req_t *
 741 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 742 {
 743         va_list ap;
 744         int sigpending, err;
 745         unsigned long flags;
 746         struct p9_req_t *req;
 747
 748         va_start(ap, fmt);
 749         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 750         va_end(ap);
 751         if (IS_ERR(req))
 752                 return req;
 753
 754         if (signal_pending(current)) {
 755                 sigpending = 1;
 756                 clear_thread_flag(TIF_SIGPENDING);
 757         } else
 758                 sigpending = 0;
 759
 760         err = c->trans_mod->request(c, req);
 761         if (err < 0) {
 762                 if (err != -ERESTARTSYS && err != -EFAULT)
 763                         c->status = Disconnected;
 764                 goto recalc_sigpending;
 765         }
 766 again:
 767         /* Wait for the response */
 768         err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
 769
 770         /*
 771          * Make sure our req is coherent with regard to updates in other
 772          * threads - echoes to wmb() in the callback
 773          */
 774         smp_rmb();
 775
 776         if ((err == -ERESTARTSYS) && (c->status == Connected)
 777                                   && (type == P9_TFLUSH)) {
 778                 sigpending = 1;
 779                 clear_thread_flag(TIF_SIGPENDING);
 780                 goto again;
 781         }
 782
 783         if (req->status == REQ_STATUS_ERROR) {
 784                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 785                 err = req->t_err;
 786         }
 787         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 788                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 789                 sigpending = 1;
 790                 clear_thread_flag(TIF_SIGPENDING);
 791
 792                 if (c->trans_mod->cancel(c, req))
 793                         p9_client_flush(c, req);
 794
 795                 /* if we received the response anyway, don't signal error */
 796                 if (req->status == REQ_STATUS_RCVD)
 797                         err = 0;
 798         }
 799 recalc_sigpending:
 800         if (sigpending) {
 801                 spin_lock_irqsave(&current->sighand->siglock, flags);
 802                 recalc_sigpending();
 803                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 804         }
 805         if (err < 0)
 806                 goto reterr;
 807
 808         err = p9_check_errors(c, req);
 809         trace_9p_client_res(c, type, req->rc->tag, err);
 810         if (!err)
 811                 return req;
 812 reterr:
 813         p9_free_req(c, req);
 814         return ERR_PTR(safe_errno(err));
 815 }
 816
 817 /**
 818  * p9_client_zc_rpc - issue a request and wait for a response
 819  * @c: client session
 820  * @type: type of request
 821  * @uidata: destination for zero copy read
 822  * @uodata: source for zero copy write
 823  * @inlen: read buffer size
 824  * @olen: write buffer size
 825  * @hdrlen: reader header size, This is the size of response protocol data
 826  * @fmt: protocol format string (see protocol.c)
 827  *
 828  * Returns request structure (which client must free using p9_free_req)
 829  */
 830 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 831                                          struct iov_iter *uidata,
 832                                          struct iov_iter *uodata,
 833                                          int inlen, int olen, int in_hdrlen,
 834                                          const char *fmt, ...)
 835 {
 836         va_list ap;
 837         int sigpending, err;
 838         unsigned long flags;
 839         struct p9_req_t *req;
 840
 841         va_start(ap, fmt);
 842         /*
 843          * We allocate a inline protocol data of only 4k bytes.
 844          * The actual content is passed in zero-copy fashion.
 845          */
 846         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 847         va_end(ap);
 848         if (IS_ERR(req))
 849                 return req;
 850
 851         if (signal_pending(current)) {
 852                 sigpending = 1;
 853                 clear_thread_flag(TIF_SIGPENDING);
 854         } else
 855                 sigpending = 0;
 856
 857         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 858                                        inlen, olen, in_hdrlen);
 859         if (err < 0) {
 860                 if (err == -EIO)
 861                         c->status = Disconnected;
 862                 if (err != -ERESTARTSYS)
 863                         goto recalc_sigpending;
 864         }
 865         if (req->status == REQ_STATUS_ERROR) {
 866                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 867                 err = req->t_err;
 868         }
 869         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 870                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 871                 sigpending = 1;
 872                 clear_thread_flag(TIF_SIGPENDING);
 873
 874                 if (c->trans_mod->cancel(c, req))
 875                         p9_client_flush(c, req);
 876
 877                 /* if we received the response anyway, don't signal error */
 878                 if (req->status == REQ_STATUS_RCVD)
 879                         err = 0;
 880         }
 881 recalc_sigpending:
 882         if (sigpending) {
 883                 spin_lock_irqsave(&current->sighand->siglock, flags);
 884                 recalc_sigpending();
 885                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 886         }
 887         if (err < 0)
 888                 goto reterr;
 889
 890         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 891         trace_9p_client_res(c, type, req->rc->tag, err);
 892         if (!err)
 893                 return req;
 894 reterr:
 895         p9_free_req(c, req);
 896         return ERR_PTR(safe_errno(err));
 897 }
 898
 899 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 900 {
 901         int ret;
 902         struct p9_fid *fid;
 903
 904         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 905         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 906         if (!fid)
 907                 return NULL;
 908
 909         memset(&fid->qid, 0, sizeof(struct p9_qid));
 910         fid->mode = -1;
 911         fid->uid = current_fsuid();
 912         fid->clnt = clnt;
 913         fid->rdir = NULL;
 914         fid->fid = 0;
 915
 916         idr_preload(GFP_KERNEL);
 917         spin_lock_irq(&clnt->lock);
 918         ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
 919                             GFP_NOWAIT);
 920         spin_unlock_irq(&clnt->lock);
 921         idr_preload_end();
 922
 923         if (!ret)
 924                 return fid;
 925
 926         kfree(fid);
 927         return NULL;
 928 }
 929
 930 static void p9_fid_destroy(struct p9_fid *fid)
 931 {
 932         struct p9_client *clnt;
 933         unsigned long flags;
 934
 935         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 936         clnt = fid->clnt;
 937         spin_lock_irqsave(&clnt->lock, flags);
 938         idr_remove(&clnt->fids, fid->fid);
 939         spin_unlock_irqrestore(&clnt->lock, flags);
 940         kfree(fid->rdir);
 941         kfree(fid);
 942 }
 943
 944 static int p9_client_version(struct p9_client *c)
 945 {
 946         int err = 0;
 947         struct p9_req_t *req;
 948         char *version = NULL;
 949         int msize;
 950
 951         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 952                  c->msize, c->proto_version);
 953
 954         switch (c->proto_version) {
 955         case p9_proto_2000L:
 956                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 957                                         c->msize, "9P2000.L");
 958                 break;
 959         case p9_proto_2000u:
 960                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 961                                         c->msize, "9P2000.u");
 962                 break;
 963         case p9_proto_legacy:
 964                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 965                                         c->msize, "9P2000");
 966                 break;
 967         default:
 968                 return -EINVAL;
 969         }
 970
 971         if (IS_ERR(req))
 972                 return PTR_ERR(req);
 973
 974         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 975         if (err) {
 976                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 977                 trace_9p_protocol_dump(c, req->rc);
 978                 goto error;
 979         }
 980
 981         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 982         if (!strncmp(version, "9P2000.L", 8))
 983                 c->proto_version = p9_proto_2000L;
 984         else if (!strncmp(version, "9P2000.u", 8))
 985                 c->proto_version = p9_proto_2000u;
 986         else if (!strncmp(version, "9P2000", 6))
 987                 c->proto_version = p9_proto_legacy;
 988         else {
 989                 err = -EREMOTEIO;
 990                 goto error;
 991         }
 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         idr_init(&clnt->fids);
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         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1042                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1043
1044         err = clnt->trans_mod->create(clnt, dev_name, options);
1045         if (err)
1046                 goto put_trans;
1047
1048         if (clnt->msize > clnt->trans_mod->maxsize)
1049                 clnt->msize = clnt->trans_mod->maxsize;
1050
1051         err = p9_client_version(clnt);
1052         if (err)
1053                 goto close_trans;
1054
1055         return clnt;
1056
1057 close_trans:
1058         clnt->trans_mod->close(clnt);
1059 put_trans:
1060         v9fs_put_trans(clnt->trans_mod);
1061 destroy_tagpool:
1062         p9_idpool_destroy(clnt->tagpool);
1063 free_client:
1064         kfree(clnt);
1065         return ERR_PTR(err);
1066 }
1067 EXPORT_SYMBOL(p9_client_create);
1068
1069 void p9_client_destroy(struct p9_client *clnt)
1070 {
1071         struct p9_fid *fid;
1072         int id;
1073
1074         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1075
1076         if (clnt->trans_mod)
1077                 clnt->trans_mod->close(clnt);
1078
1079         v9fs_put_trans(clnt->trans_mod);
1080
1081         idr_for_each_entry(&clnt->fids, fid, id) {
1082                 pr_info("Found fid %d not clunked\n", fid->fid);
1083                 p9_fid_destroy(fid);
1084         }
1085
1086         p9_tag_cleanup(clnt);
1087
1088         kfree(clnt);
1089 }
1090 EXPORT_SYMBOL(p9_client_destroy);
1091
1092 void p9_client_disconnect(struct p9_client *clnt)
1093 {
1094         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1095         clnt->status = Disconnected;
1096 }
1097 EXPORT_SYMBOL(p9_client_disconnect);
1098
1099 void p9_client_begin_disconnect(struct p9_client *clnt)
1100 {
1101         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1102         clnt->status = BeginDisconnect;
1103 }
1104 EXPORT_SYMBOL(p9_client_begin_disconnect);
1105
1106 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1107         const char *uname, kuid_t n_uname, const char *aname)
1108 {
1109         int err = 0;
1110         struct p9_req_t *req;
1111         struct p9_fid *fid;
1112         struct p9_qid qid;
1113
1114
1115         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1116                  afid ? afid->fid : -1, uname, aname);
1117         fid = p9_fid_create(clnt);
1118         if (!fid) {
1119                 err = -ENOMEM;
1120                 goto error;
1121         }
1122         fid->uid = n_uname;
1123
1124         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1125                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1126         if (IS_ERR(req)) {
1127                 err = PTR_ERR(req);
1128                 goto error;
1129         }
1130
1131         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1132         if (err) {
1133                 trace_9p_protocol_dump(clnt, req->rc);
1134                 p9_free_req(clnt, req);
1135                 goto error;
1136         }
1137
1138         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1139                  qid.type, (unsigned long long)qid.path, qid.version);
1140
1141         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1142
1143         p9_free_req(clnt, req);
1144         return fid;
1145
1146 error:
1147         if (fid)
1148                 p9_fid_destroy(fid);
1149         return ERR_PTR(err);
1150 }
1151 EXPORT_SYMBOL(p9_client_attach);
1152
1153 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1154                 const unsigned char * const *wnames, int clone)
1155 {
1156         int err;
1157         struct p9_client *clnt;
1158         struct p9_fid *fid;
1159         struct p9_qid *wqids;
1160         struct p9_req_t *req;
1161         uint16_t nwqids, count;
1162
1163         err = 0;
1164         wqids = NULL;
1165         clnt = oldfid->clnt;
1166         if (clone) {
1167                 fid = p9_fid_create(clnt);
1168                 if (!fid) {
1169                         err = -ENOMEM;
1170                         goto error;
1171                 }
1172
1173                 fid->uid = oldfid->uid;
1174         } else
1175                 fid = oldfid;
1176
1177
1178         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1179                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1180
1181         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1182                                                                 nwname, wnames);
1183         if (IS_ERR(req)) {
1184                 err = PTR_ERR(req);
1185                 goto error;
1186         }
1187
1188         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1189         if (err) {
1190                 trace_9p_protocol_dump(clnt, req->rc);
1191                 p9_free_req(clnt, req);
1192                 goto clunk_fid;
1193         }
1194         p9_free_req(clnt, req);
1195
1196         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1197
1198         if (nwqids != nwname) {
1199                 err = -ENOENT;
1200                 goto clunk_fid;
1201         }
1202
1203         for (count = 0; count < nwqids; count++)
1204                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1205                         count, wqids[count].type,
1206                         (unsigned long long)wqids[count].path,
1207                         wqids[count].version);
1208
1209         if (nwname)
1210                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1211         else
1212                 fid->qid = oldfid->qid;
1213
1214         kfree(wqids);
1215         return fid;
1216
1217 clunk_fid:
1218         kfree(wqids);
1219         p9_client_clunk(fid);
1220         fid = NULL;
1221
1222 error:
1223         if (fid && (fid != oldfid))
1224                 p9_fid_destroy(fid);
1225
1226         return ERR_PTR(err);
1227 }
1228 EXPORT_SYMBOL(p9_client_walk);
1229
1230 int p9_client_open(struct p9_fid *fid, int mode)
1231 {
1232         int err;
1233         struct p9_client *clnt;
1234         struct p9_req_t *req;
1235         struct p9_qid qid;
1236         int iounit;
1237
1238         clnt = fid->clnt;
1239         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1240                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1241         err = 0;
1242
1243         if (fid->mode != -1)
1244                 return -EINVAL;
1245
1246         if (p9_is_proto_dotl(clnt))
1247                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1248         else
1249                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1250         if (IS_ERR(req)) {
1251                 err = PTR_ERR(req);
1252                 goto error;
1253         }
1254
1255         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1256         if (err) {
1257                 trace_9p_protocol_dump(clnt, req->rc);
1258                 goto free_and_error;
1259         }
1260
1261         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1262                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1263                 (unsigned long long)qid.path, qid.version, iounit);
1264
1265         fid->mode = mode;
1266         fid->iounit = iounit;
1267
1268 free_and_error:
1269         p9_free_req(clnt, req);
1270 error:
1271         return err;
1272 }
1273 EXPORT_SYMBOL(p9_client_open);
1274
1275 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1276                 kgid_t gid, struct p9_qid *qid)
1277 {
1278         int err = 0;
1279         struct p9_client *clnt;
1280         struct p9_req_t *req;
1281         int iounit;
1282
1283         p9_debug(P9_DEBUG_9P,
1284                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1285                         ofid->fid, name, flags, mode,
1286                         from_kgid(&init_user_ns, gid));
1287         clnt = ofid->clnt;
1288
1289         if (ofid->mode != -1)
1290                 return -EINVAL;
1291
1292         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1293                         mode, gid);
1294         if (IS_ERR(req)) {
1295                 err = PTR_ERR(req);
1296                 goto error;
1297         }
1298
1299         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1300         if (err) {
1301                 trace_9p_protocol_dump(clnt, req->rc);
1302                 goto free_and_error;
1303         }
1304
1305         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1306                         qid->type,
1307                         (unsigned long long)qid->path,
1308                         qid->version, iounit);
1309
1310         ofid->mode = mode;
1311         ofid->iounit = iounit;
1312
1313 free_and_error:
1314         p9_free_req(clnt, req);
1315 error:
1316         return err;
1317 }
1318 EXPORT_SYMBOL(p9_client_create_dotl);
1319
1320 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1321                      char *extension)
1322 {
1323         int err;
1324         struct p9_client *clnt;
1325         struct p9_req_t *req;
1326         struct p9_qid qid;
1327         int iounit;
1328
1329         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1330                                                 fid->fid, name, perm, mode);
1331         err = 0;
1332         clnt = fid->clnt;
1333
1334         if (fid->mode != -1)
1335                 return -EINVAL;
1336
1337         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1338                                 mode, extension);
1339         if (IS_ERR(req)) {
1340                 err = PTR_ERR(req);
1341                 goto error;
1342         }
1343
1344         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1345         if (err) {
1346                 trace_9p_protocol_dump(clnt, req->rc);
1347                 goto free_and_error;
1348         }
1349
1350         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1351                                 qid.type,
1352                                 (unsigned long long)qid.path,
1353                                 qid.version, iounit);
1354
1355         fid->mode = mode;
1356         fid->iounit = iounit;
1357
1358 free_and_error:
1359         p9_free_req(clnt, req);
1360 error:
1361         return err;
1362 }
1363 EXPORT_SYMBOL(p9_client_fcreate);
1364
1365 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1366                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1367 {
1368         int err = 0;
1369         struct p9_client *clnt;
1370         struct p9_req_t *req;
1371
1372         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1373                         dfid->fid, name, symtgt);
1374         clnt = dfid->clnt;
1375
1376         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1377                         gid);
1378         if (IS_ERR(req)) {
1379                 err = PTR_ERR(req);
1380                 goto error;
1381         }
1382
1383         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1384         if (err) {
1385                 trace_9p_protocol_dump(clnt, req->rc);
1386                 goto free_and_error;
1387         }
1388
1389         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1390                         qid->type, (unsigned long long)qid->path, qid->version);
1391
1392 free_and_error:
1393         p9_free_req(clnt, req);
1394 error:
1395         return err;
1396 }
1397 EXPORT_SYMBOL(p9_client_symlink);
1398
1399 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1400 {
1401         struct p9_client *clnt;
1402         struct p9_req_t *req;
1403
1404         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1405                         dfid->fid, oldfid->fid, newname);
1406         clnt = dfid->clnt;
1407         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1408                         newname);
1409         if (IS_ERR(req))
1410                 return PTR_ERR(req);
1411
1412         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1413         p9_free_req(clnt, req);
1414         return 0;
1415 }
1416 EXPORT_SYMBOL(p9_client_link);
1417
1418 int p9_client_fsync(struct p9_fid *fid, int datasync)
1419 {
1420         int err;
1421         struct p9_client *clnt;
1422         struct p9_req_t *req;
1423
1424         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1425                         fid->fid, datasync);
1426         err = 0;
1427         clnt = fid->clnt;
1428
1429         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1430         if (IS_ERR(req)) {
1431                 err = PTR_ERR(req);
1432                 goto error;
1433         }
1434
1435         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1436
1437         p9_free_req(clnt, req);
1438
1439 error:
1440         return err;
1441 }
1442 EXPORT_SYMBOL(p9_client_fsync);
1443
1444 int p9_client_clunk(struct p9_fid *fid)
1445 {
1446         int err;
1447         struct p9_client *clnt;
1448         struct p9_req_t *req;
1449         int retries = 0;
1450
1451         if (!fid) {
1452                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1453                         __func__, task_pid_nr(current));
1454                 dump_stack();
1455                 return 0;
1456         }
1457
1458 again:
1459         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1460                                                                 retries);
1461         err = 0;
1462         clnt = fid->clnt;
1463
1464         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1465         if (IS_ERR(req)) {
1466                 err = PTR_ERR(req);
1467                 goto error;
1468         }
1469
1470         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1471
1472         p9_free_req(clnt, req);
1473 error:
1474         /*
1475          * Fid is not valid even after a failed clunk
1476          * If interrupted, retry once then give up and
1477          * leak fid until umount.
1478          */
1479         if (err == -ERESTARTSYS) {
1480                 if (retries++ == 0)
1481                         goto again;
1482         } else
1483                 p9_fid_destroy(fid);
1484         return err;
1485 }
1486 EXPORT_SYMBOL(p9_client_clunk);
1487
1488 int p9_client_remove(struct p9_fid *fid)
1489 {
1490         int err;
1491         struct p9_client *clnt;
1492         struct p9_req_t *req;
1493
1494         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1495         err = 0;
1496         clnt = fid->clnt;
1497
1498         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1499         if (IS_ERR(req)) {
1500                 err = PTR_ERR(req);
1501                 goto error;
1502         }
1503
1504         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1505
1506         p9_free_req(clnt, req);
1507 error:
1508         if (err == -ERESTARTSYS)
1509                 p9_client_clunk(fid);
1510         else
1511                 p9_fid_destroy(fid);
1512         return err;
1513 }
1514 EXPORT_SYMBOL(p9_client_remove);
1515
1516 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1517 {
1518         int err = 0;
1519         struct p9_req_t *req;
1520         struct p9_client *clnt;
1521
1522         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1523                    dfid->fid, name, flags);
1524
1525         clnt = dfid->clnt;
1526         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1527         if (IS_ERR(req)) {
1528                 err = PTR_ERR(req);
1529                 goto error;
1530         }
1531         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1532
1533         p9_free_req(clnt, req);
1534 error:
1535         return err;
1536 }
1537 EXPORT_SYMBOL(p9_client_unlinkat);
1538
1539 int
1540 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1541 {
1542         struct p9_client *clnt = fid->clnt;
1543         struct p9_req_t *req;
1544         int total = 0;
1545         *err = 0;
1546
1547         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1548                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1549
1550         while (iov_iter_count(to)) {
1551                 int count = iov_iter_count(to);
1552                 int rsize, non_zc = 0;
1553                 char *dataptr;
1554
1555                 rsize = fid->iounit;
1556                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1557                         rsize = clnt->msize - P9_IOHDRSZ;
1558
1559                 if (count < rsize)
1560                         rsize = count;
1561
1562                 /* Don't bother zerocopy for small IO (< 1024) */
1563                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1564                         /*
1565                          * response header len is 11
1566                          * PDU Header(7) + IO Size (4)
1567                          */
1568                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1569                                                0, 11, "dqd", fid->fid,
1570                                                offset, rsize);
1571                 } else {
1572                         non_zc = 1;
1573                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1574                                             rsize);
1575                 }
1576                 if (IS_ERR(req)) {
1577                         *err = PTR_ERR(req);
1578                         break;
1579                 }
1580
1581                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1582                                    "D", &count, &dataptr);
1583                 if (*err) {
1584                         trace_9p_protocol_dump(clnt, req->rc);
1585                         p9_free_req(clnt, req);
1586                         break;
1587                 }
1588                 if (rsize < count) {
1589                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1590                         count = rsize;
1591                 }
1592
1593                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1594                 if (!count) {
1595                         p9_free_req(clnt, req);
1596                         break;
1597                 }
1598
1599                 if (non_zc) {
1600                         int n = copy_to_iter(dataptr, count, to);
1601                         total += n;
1602                         offset += n;
1603                         if (n != count) {
1604                                 *err = -EFAULT;
1605                                 p9_free_req(clnt, req);
1606                                 break;
1607                         }
1608                 } else {
1609                         iov_iter_advance(to, count);
1610                         total += count;
1611                         offset += count;
1612                 }
1613                 p9_free_req(clnt, req);
1614         }
1615         return total;
1616 }
1617 EXPORT_SYMBOL(p9_client_read);
1618
1619 int
1620 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1621 {
1622         struct p9_client *clnt = fid->clnt;
1623         struct p9_req_t *req;
1624         int total = 0;
1625         *err = 0;
1626
1627         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1628                                 fid->fid, (unsigned long long) offset,
1629                                 iov_iter_count(from));
1630
1631         while (iov_iter_count(from)) {
1632                 int count = iov_iter_count(from);
1633                 int rsize = fid->iounit;
1634                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1635                         rsize = clnt->msize - P9_IOHDRSZ;
1636
1637                 if (count < rsize)
1638                         rsize = count;
1639
1640                 /* Don't bother zerocopy for small IO (< 1024) */
1641                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1642                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1643                                                rsize, P9_ZC_HDR_SZ, "dqd",
1644                                                fid->fid, offset, rsize);
1645                 } else {
1646                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1647                                                     offset, rsize, from);
1648                 }
1649                 if (IS_ERR(req)) {
1650                         *err = PTR_ERR(req);
1651                         break;
1652                 }
1653
1654                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1655                 if (*err) {
1656                         trace_9p_protocol_dump(clnt, req->rc);
1657                         p9_free_req(clnt, req);
1658                         break;
1659                 }
1660                 if (rsize < count) {
1661                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1662                         count = rsize;
1663                 }
1664
1665                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1666
1667                 p9_free_req(clnt, req);
1668                 iov_iter_advance(from, count);
1669                 total += count;
1670                 offset += count;
1671         }
1672         return total;
1673 }
1674 EXPORT_SYMBOL(p9_client_write);
1675
1676 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1677 {
1678         int err;
1679         struct p9_client *clnt;
1680         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1681         struct p9_req_t *req;
1682         u16 ignored;
1683
1684         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1685
1686         if (!ret)
1687                 return ERR_PTR(-ENOMEM);
1688
1689         err = 0;
1690         clnt = fid->clnt;
1691
1692         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1693         if (IS_ERR(req)) {
1694                 err = PTR_ERR(req);
1695                 goto error;
1696         }
1697
1698         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1699         if (err) {
1700                 trace_9p_protocol_dump(clnt, req->rc);
1701                 p9_free_req(clnt, req);
1702                 goto error;
1703         }
1704
1705         p9_debug(P9_DEBUG_9P,
1706                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1707                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1708                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1709                 "<<<    uid=%d gid=%d n_muid=%d\n",
1710                 ret->size, ret->type, ret->dev, ret->qid.type,
1711                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1712                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1713                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1714                 from_kuid(&init_user_ns, ret->n_uid),
1715                 from_kgid(&init_user_ns, ret->n_gid),
1716                 from_kuid(&init_user_ns, ret->n_muid));
1717
1718         p9_free_req(clnt, req);
1719         return ret;
1720
1721 error:
1722         kfree(ret);
1723         return ERR_PTR(err);
1724 }
1725 EXPORT_SYMBOL(p9_client_stat);
1726
1727 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1728                                                         u64 request_mask)
1729 {
1730         int err;
1731         struct p9_client *clnt;
1732         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1733                                                                 GFP_KERNEL);
1734         struct p9_req_t *req;
1735
1736         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1737                                                         fid->fid, request_mask);
1738
1739         if (!ret)
1740                 return ERR_PTR(-ENOMEM);
1741
1742         err = 0;
1743         clnt = fid->clnt;
1744
1745         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1746         if (IS_ERR(req)) {
1747                 err = PTR_ERR(req);
1748                 goto error;
1749         }
1750
1751         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1752         if (err) {
1753                 trace_9p_protocol_dump(clnt, req->rc);
1754                 p9_free_req(clnt, req);
1755                 goto error;
1756         }
1757
1758         p9_debug(P9_DEBUG_9P,
1759                 "<<< RGETATTR st_result_mask=%lld\n"
1760                 "<<< qid=%x.%llx.%x\n"
1761                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1762                 "<<< st_uid=%d st_gid=%d\n"
1763                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1764                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1765                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1766                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1767                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1768                 "<<< st_gen=%lld st_data_version=%lld\n",
1769                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1770                 ret->qid.version, ret->st_mode, ret->st_nlink,
1771                 from_kuid(&init_user_ns, ret->st_uid),
1772                 from_kgid(&init_user_ns, ret->st_gid),
1773                 ret->st_rdev, ret->st_size, ret->st_blksize,
1774                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1775                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1776                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1777                 ret->st_gen, ret->st_data_version);
1778
1779         p9_free_req(clnt, req);
1780         return ret;
1781
1782 error:
1783         kfree(ret);
1784         return ERR_PTR(err);
1785 }
1786 EXPORT_SYMBOL(p9_client_getattr_dotl);
1787
1788 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1789 {
1790         int ret;
1791
1792         /* NOTE: size shouldn't include its own length */
1793         /* size[2] type[2] dev[4] qid[13] */
1794         /* mode[4] atime[4] mtime[4] length[8]*/
1795         /* name[s] uid[s] gid[s] muid[s] */
1796         ret = 2+4+13+4+4+4+8+2+2+2+2;
1797
1798         if (wst->name)
1799                 ret += strlen(wst->name);
1800         if (wst->uid)
1801                 ret += strlen(wst->uid);
1802         if (wst->gid)
1803                 ret += strlen(wst->gid);
1804         if (wst->muid)
1805                 ret += strlen(wst->muid);
1806
1807         if ((proto_version == p9_proto_2000u) ||
1808                 (proto_version == p9_proto_2000L)) {
1809                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1810                 if (wst->extension)
1811                         ret += strlen(wst->extension);
1812         }
1813
1814         return ret;
1815 }
1816
1817 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1818 {
1819         int err;
1820         struct p9_req_t *req;
1821         struct p9_client *clnt;
1822
1823         err = 0;
1824         clnt = fid->clnt;
1825         wst->size = p9_client_statsize(wst, clnt->proto_version);
1826         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1827         p9_debug(P9_DEBUG_9P,
1828                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1829                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1830                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1831                 "     uid=%d gid=%d n_muid=%d\n",
1832                 wst->size, wst->type, wst->dev, wst->qid.type,
1833                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1834                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1835                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1836                 from_kuid(&init_user_ns, wst->n_uid),
1837                 from_kgid(&init_user_ns, wst->n_gid),
1838                 from_kuid(&init_user_ns, wst->n_muid));
1839
1840         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1841         if (IS_ERR(req)) {
1842                 err = PTR_ERR(req);
1843                 goto error;
1844         }
1845
1846         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1847
1848         p9_free_req(clnt, req);
1849 error:
1850         return err;
1851 }
1852 EXPORT_SYMBOL(p9_client_wstat);
1853
1854 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1855 {
1856         int err;
1857         struct p9_req_t *req;
1858         struct p9_client *clnt;
1859
1860         err = 0;
1861         clnt = fid->clnt;
1862         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1863         p9_debug(P9_DEBUG_9P,
1864                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1865                 "    atime_sec=%lld atime_nsec=%lld\n"
1866                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1867                 p9attr->valid, p9attr->mode,
1868                 from_kuid(&init_user_ns, p9attr->uid),
1869                 from_kgid(&init_user_ns, p9attr->gid),
1870                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1871                 p9attr->mtime_sec, p9attr->mtime_nsec);
1872
1873         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1874
1875         if (IS_ERR(req)) {
1876                 err = PTR_ERR(req);
1877                 goto error;
1878         }
1879         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1880         p9_free_req(clnt, req);
1881 error:
1882         return err;
1883 }
1884 EXPORT_SYMBOL(p9_client_setattr);
1885
1886 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1887 {
1888         int err;
1889         struct p9_req_t *req;
1890         struct p9_client *clnt;
1891
1892         err = 0;
1893         clnt = fid->clnt;
1894
1895         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1896
1897         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1898         if (IS_ERR(req)) {
1899                 err = PTR_ERR(req);
1900                 goto error;
1901         }
1902
1903         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1904                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1905                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1906         if (err) {
1907                 trace_9p_protocol_dump(clnt, req->rc);
1908                 p9_free_req(clnt, req);
1909                 goto error;
1910         }
1911
1912         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1913                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1914                 "fsid %llu namelen %ld\n",
1915                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1916                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1917                 sb->fsid, (long int)sb->namelen);
1918
1919         p9_free_req(clnt, req);
1920 error:
1921         return err;
1922 }
1923 EXPORT_SYMBOL(p9_client_statfs);
1924
1925 int p9_client_rename(struct p9_fid *fid,
1926                      struct p9_fid *newdirfid, const char *name)
1927 {
1928         int err;
1929         struct p9_req_t *req;
1930         struct p9_client *clnt;
1931
1932         err = 0;
1933         clnt = fid->clnt;
1934
1935         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1936                         fid->fid, newdirfid->fid, name);
1937
1938         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1939                         newdirfid->fid, name);
1940         if (IS_ERR(req)) {
1941                 err = PTR_ERR(req);
1942                 goto error;
1943         }
1944
1945         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1946
1947         p9_free_req(clnt, req);
1948 error:
1949         return err;
1950 }
1951 EXPORT_SYMBOL(p9_client_rename);
1952
1953 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1954                        struct p9_fid *newdirfid, const char *new_name)
1955 {
1956         int err;
1957         struct p9_req_t *req;
1958         struct p9_client *clnt;
1959
1960         err = 0;
1961         clnt = olddirfid->clnt;
1962
1963         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1964                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1965                    newdirfid->fid, new_name);
1966
1967         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1968                             old_name, newdirfid->fid, new_name);
1969         if (IS_ERR(req)) {
1970                 err = PTR_ERR(req);
1971                 goto error;
1972         }
1973
1974         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1975                    newdirfid->fid, new_name);
1976
1977         p9_free_req(clnt, req);
1978 error:
1979         return err;
1980 }
1981 EXPORT_SYMBOL(p9_client_renameat);
1982
1983 /*
1984  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1985  */
1986 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1987                                 const char *attr_name, u64 *attr_size)
1988 {
1989         int err;
1990         struct p9_req_t *req;
1991         struct p9_client *clnt;
1992         struct p9_fid *attr_fid;
1993
1994         err = 0;
1995         clnt = file_fid->clnt;
1996         attr_fid = p9_fid_create(clnt);
1997         if (!attr_fid) {
1998                 err = -ENOMEM;
1999                 goto error;
2000         }
2001         p9_debug(P9_DEBUG_9P,
2002                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2003                 file_fid->fid, attr_fid->fid, attr_name);
2004
2005         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2006                         file_fid->fid, attr_fid->fid, attr_name);
2007         if (IS_ERR(req)) {
2008                 err = PTR_ERR(req);
2009                 goto error;
2010         }
2011         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2012         if (err) {
2013                 trace_9p_protocol_dump(clnt, req->rc);
2014                 p9_free_req(clnt, req);
2015                 goto clunk_fid;
2016         }
2017         p9_free_req(clnt, req);
2018         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2019                 attr_fid->fid, *attr_size);
2020         return attr_fid;
2021 clunk_fid:
2022         p9_client_clunk(attr_fid);
2023         attr_fid = NULL;
2024 error:
2025         if (attr_fid && (attr_fid != file_fid))
2026                 p9_fid_destroy(attr_fid);
2027
2028         return ERR_PTR(err);
2029 }
2030 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2031
2032 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2033                         u64 attr_size, int flags)
2034 {
2035         int err;
2036         struct p9_req_t *req;
2037         struct p9_client *clnt;
2038
2039         p9_debug(P9_DEBUG_9P,
2040                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2041                 fid->fid, name, (long long)attr_size, flags);
2042         err = 0;
2043         clnt = fid->clnt;
2044         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2045                         fid->fid, name, attr_size, flags);
2046         if (IS_ERR(req)) {
2047                 err = PTR_ERR(req);
2048                 goto error;
2049         }
2050         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2051         p9_free_req(clnt, req);
2052 error:
2053         return err;
2054 }
2055 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2056
2057 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2058 {
2059         int err, rsize, non_zc = 0;
2060         struct p9_client *clnt;
2061         struct p9_req_t *req;
2062         char *dataptr;
2063         struct kvec kv = {.iov_base = data, .iov_len = count};
2064         struct iov_iter to;
2065
2066         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2067
2068         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2069                                 fid->fid, (unsigned long long) offset, count);
2070
2071         err = 0;
2072         clnt = fid->clnt;
2073
2074         rsize = fid->iounit;
2075         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2076                 rsize = clnt->msize - P9_READDIRHDRSZ;
2077
2078         if (count < rsize)
2079                 rsize = count;
2080
2081         /* Don't bother zerocopy for small IO (< 1024) */
2082         if (clnt->trans_mod->zc_request && rsize > 1024) {
2083                 /*
2084                  * response header len is 11
2085                  * PDU Header(7) + IO Size (4)
2086                  */
2087                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2088                                        11, "dqd", fid->fid, offset, rsize);
2089         } else {
2090                 non_zc = 1;
2091                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2092                                     offset, rsize);
2093         }
2094         if (IS_ERR(req)) {
2095                 err = PTR_ERR(req);
2096                 goto error;
2097         }
2098
2099         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2100         if (err) {
2101                 trace_9p_protocol_dump(clnt, req->rc);
2102                 goto free_and_error;
2103         }
2104         if (rsize < count) {
2105                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2106                 count = rsize;
2107         }
2108
2109         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2110
2111         if (non_zc)
2112                 memmove(data, dataptr, count);
2113
2114         p9_free_req(clnt, req);
2115         return count;
2116
2117 free_and_error:
2118         p9_free_req(clnt, req);
2119 error:
2120         return err;
2121 }
2122 EXPORT_SYMBOL(p9_client_readdir);
2123
2124 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2125                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2126 {
2127         int err;
2128         struct p9_client *clnt;
2129         struct p9_req_t *req;
2130
2131         err = 0;
2132         clnt = fid->clnt;
2133         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2134                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2135         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2136                 MAJOR(rdev), MINOR(rdev), gid);
2137         if (IS_ERR(req))
2138                 return PTR_ERR(req);
2139
2140         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2141         if (err) {
2142                 trace_9p_protocol_dump(clnt, req->rc);
2143                 goto error;
2144         }
2145         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2146                                 (unsigned long long)qid->path, qid->version);
2147
2148 error:
2149         p9_free_req(clnt, req);
2150         return err;
2151
2152 }
2153 EXPORT_SYMBOL(p9_client_mknod_dotl);
2154
2155 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2156                                 kgid_t gid, struct p9_qid *qid)
2157 {
2158         int err;
2159         struct p9_client *clnt;
2160         struct p9_req_t *req;
2161
2162         err = 0;
2163         clnt = fid->clnt;
2164         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2165                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2166         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2167                 gid);
2168         if (IS_ERR(req))
2169                 return PTR_ERR(req);
2170
2171         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2172         if (err) {
2173                 trace_9p_protocol_dump(clnt, req->rc);
2174                 goto error;
2175         }
2176         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2177                                 (unsigned long long)qid->path, qid->version);
2178
2179 error:
2180         p9_free_req(clnt, req);
2181         return err;
2182
2183 }
2184 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2185
2186 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2187 {
2188         int err;
2189         struct p9_client *clnt;
2190         struct p9_req_t *req;
2191
2192         err = 0;
2193         clnt = fid->clnt;
2194         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2195                         "start %lld length %lld proc_id %d client_id %s\n",
2196                         fid->fid, flock->type, flock->flags, flock->start,
2197                         flock->length, flock->proc_id, flock->client_id);
2198
2199         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2200                                 flock->flags, flock->start, flock->length,
2201                                         flock->proc_id, flock->client_id);
2202
2203         if (IS_ERR(req))
2204                 return PTR_ERR(req);
2205
2206         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2207         if (err) {
2208                 trace_9p_protocol_dump(clnt, req->rc);
2209                 goto error;
2210         }
2211         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2212 error:
2213         p9_free_req(clnt, req);
2214         return err;
2215
2216 }
2217 EXPORT_SYMBOL(p9_client_lock_dotl);
2218
2219 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2220 {
2221         int err;
2222         struct p9_client *clnt;
2223         struct p9_req_t *req;
2224
2225         err = 0;
2226         clnt = fid->clnt;
2227         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2228                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2229                 glock->start, glock->length, glock->proc_id, glock->client_id);
2230
2231         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2232                 glock->start, glock->length, glock->proc_id, glock->client_id);
2233
2234         if (IS_ERR(req))
2235                 return PTR_ERR(req);
2236
2237         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2238                         &glock->start, &glock->length, &glock->proc_id,
2239                         &glock->client_id);
2240         if (err) {
2241                 trace_9p_protocol_dump(clnt, req->rc);
2242                 goto error;
2243         }
2244         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2245                 "proc_id %d client_id %s\n", glock->type, glock->start,
2246                 glock->length, glock->proc_id, glock->client_id);
2247 error:
2248         p9_free_req(clnt, req);
2249         return err;
2250 }
2251 EXPORT_SYMBOL(p9_client_getlock_dotl);
2252
2253 int p9_client_readlink(struct p9_fid *fid, char **target)
2254 {
2255         int err;
2256         struct p9_client *clnt;
2257         struct p9_req_t *req;
2258
2259         err = 0;
2260         clnt = fid->clnt;
2261         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2262
2263         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2264         if (IS_ERR(req))
2265                 return PTR_ERR(req);
2266
2267         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2268         if (err) {
2269                 trace_9p_protocol_dump(clnt, req->rc);
2270                 goto error;
2271         }
2272         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2273 error:
2274         p9_free_req(clnt, req);
2275         return err;
2276 }
2277 EXPORT_SYMBOL(p9_client_readlink);