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