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                 goto reterr;
 847         }
 848         if (req->status == REQ_STATUS_ERROR) {
 849                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 850                 err = req->t_err;
 851         }
 852         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 853                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 854                 sigpending = 1;
 855                 clear_thread_flag(TIF_SIGPENDING);
 856
 857                 if (c->trans_mod->cancel(c, req))
 858                         p9_client_flush(c, req);
 859
 860                 /* if we received the response anyway, don't signal error */
 861                 if (req->status == REQ_STATUS_RCVD)
 862                         err = 0;
 863         }
 864         if (sigpending) {
 865                 spin_lock_irqsave(&current->sighand->siglock, flags);
 866                 recalc_sigpending();
 867                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 868         }
 869         if (err < 0)
 870                 goto reterr;
 871
 872         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 873         trace_9p_client_res(c, type, req->rc->tag, err);
 874         if (!err)
 875                 return req;
 876 reterr:
 877         p9_free_req(c, req);
 878         return ERR_PTR(safe_errno(err));
 879 }
 880
 881 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 882 {
 883         int ret;
 884         struct p9_fid *fid;
 885         unsigned long flags;
 886
 887         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 888         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 889         if (!fid)
 890                 return ERR_PTR(-ENOMEM);
 891
 892         ret = p9_idpool_get(clnt->fidpool);
 893         if (ret < 0) {
 894                 ret = -ENOSPC;
 895                 goto error;
 896         }
 897         fid->fid = ret;
 898
 899         memset(&fid->qid, 0, sizeof(struct p9_qid));
 900         fid->mode = -1;
 901         fid->uid = current_fsuid();
 902         fid->clnt = clnt;
 903         fid->rdir = NULL;
 904         spin_lock_irqsave(&clnt->lock, flags);
 905         list_add(&fid->flist, &clnt->fidlist);
 906         spin_unlock_irqrestore(&clnt->lock, flags);
 907
 908         return fid;
 909
 910 error:
 911         kfree(fid);
 912         return ERR_PTR(ret);
 913 }
 914
 915 static void p9_fid_destroy(struct p9_fid *fid)
 916 {
 917         struct p9_client *clnt;
 918         unsigned long flags;
 919
 920         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 921         clnt = fid->clnt;
 922         p9_idpool_put(fid->fid, clnt->fidpool);
 923         spin_lock_irqsave(&clnt->lock, flags);
 924         list_del(&fid->flist);
 925         spin_unlock_irqrestore(&clnt->lock, flags);
 926         kfree(fid->rdir);
 927         kfree(fid);
 928 }
 929
 930 static int p9_client_version(struct p9_client *c)
 931 {
 932         int err = 0;
 933         struct p9_req_t *req;
 934         char *version;
 935         int msize;
 936
 937         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 938                  c->msize, c->proto_version);
 939
 940         switch (c->proto_version) {
 941         case p9_proto_2000L:
 942                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 943                                         c->msize, "9P2000.L");
 944                 break;
 945         case p9_proto_2000u:
 946                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 947                                         c->msize, "9P2000.u");
 948                 break;
 949         case p9_proto_legacy:
 950                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 951                                         c->msize, "9P2000");
 952                 break;
 953         default:
 954                 return -EINVAL;
 955         }
 956
 957         if (IS_ERR(req))
 958                 return PTR_ERR(req);
 959
 960         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 961         if (err) {
 962                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 963                 trace_9p_protocol_dump(c, req->rc);
 964                 goto error;
 965         }
 966
 967         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 968         if (!strncmp(version, "9P2000.L", 8))
 969                 c->proto_version = p9_proto_2000L;
 970         else if (!strncmp(version, "9P2000.u", 8))
 971                 c->proto_version = p9_proto_2000u;
 972         else if (!strncmp(version, "9P2000", 6))
 973                 c->proto_version = p9_proto_legacy;
 974         else {
 975                 err = -EREMOTEIO;
 976                 goto error;
 977         }
 978
 979         if (msize < c->msize)
 980                 c->msize = msize;
 981
 982 error:
 983         kfree(version);
 984         p9_free_req(c, req);
 985
 986         return err;
 987 }
 988
 989 struct p9_client *p9_client_create(const char *dev_name, char *options)
 990 {
 991         int err;
 992         struct p9_client *clnt;
 993         char *client_id;
 994
 995         err = 0;
 996         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 997         if (!clnt)
 998                 return ERR_PTR(-ENOMEM);
 999
1000         clnt->trans_mod = NULL;
1001         clnt->trans = NULL;
1002
1003         client_id = utsname()->nodename;
1004         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1005
1006         spin_lock_init(&clnt->lock);
1007         INIT_LIST_HEAD(&clnt->fidlist);
1008
1009         err = p9_tag_init(clnt);
1010         if (err < 0)
1011                 goto free_client;
1012
1013         err = parse_opts(options, clnt);
1014         if (err < 0)
1015                 goto destroy_tagpool;
1016
1017         if (!clnt->trans_mod)
1018                 clnt->trans_mod = v9fs_get_default_trans();
1019
1020         if (clnt->trans_mod == NULL) {
1021                 err = -EPROTONOSUPPORT;
1022                 p9_debug(P9_DEBUG_ERROR,
1023                          "No transport defined or default transport\n");
1024                 goto destroy_tagpool;
1025         }
1026
1027         clnt->fidpool = p9_idpool_create();
1028         if (IS_ERR(clnt->fidpool)) {
1029                 err = PTR_ERR(clnt->fidpool);
1030                 goto put_trans;
1031         }
1032
1033         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1034                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1035
1036         err = clnt->trans_mod->create(clnt, dev_name, options);
1037         if (err)
1038                 goto destroy_fidpool;
1039
1040         if (clnt->msize > clnt->trans_mod->maxsize)
1041                 clnt->msize = clnt->trans_mod->maxsize;
1042
1043         err = p9_client_version(clnt);
1044         if (err)
1045                 goto close_trans;
1046
1047         return clnt;
1048
1049 close_trans:
1050         clnt->trans_mod->close(clnt);
1051 destroy_fidpool:
1052         p9_idpool_destroy(clnt->fidpool);
1053 put_trans:
1054         v9fs_put_trans(clnt->trans_mod);
1055 destroy_tagpool:
1056         p9_idpool_destroy(clnt->tagpool);
1057 free_client:
1058         kfree(clnt);
1059         return ERR_PTR(err);
1060 }
1061 EXPORT_SYMBOL(p9_client_create);
1062
1063 void p9_client_destroy(struct p9_client *clnt)
1064 {
1065         struct p9_fid *fid, *fidptr;
1066
1067         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1068
1069         if (clnt->trans_mod)
1070                 clnt->trans_mod->close(clnt);
1071
1072         v9fs_put_trans(clnt->trans_mod);
1073
1074         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1075                 pr_info("Found fid %d not clunked\n", fid->fid);
1076                 p9_fid_destroy(fid);
1077         }
1078
1079         if (clnt->fidpool)
1080                 p9_idpool_destroy(clnt->fidpool);
1081
1082         p9_tag_cleanup(clnt);
1083
1084         kfree(clnt);
1085 }
1086 EXPORT_SYMBOL(p9_client_destroy);
1087
1088 void p9_client_disconnect(struct p9_client *clnt)
1089 {
1090         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1091         clnt->status = Disconnected;
1092 }
1093 EXPORT_SYMBOL(p9_client_disconnect);
1094
1095 void p9_client_begin_disconnect(struct p9_client *clnt)
1096 {
1097         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1098         clnt->status = BeginDisconnect;
1099 }
1100 EXPORT_SYMBOL(p9_client_begin_disconnect);
1101
1102 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1103         char *uname, kuid_t n_uname, char *aname)
1104 {
1105         int err = 0;
1106         struct p9_req_t *req;
1107         struct p9_fid *fid;
1108         struct p9_qid qid;
1109
1110
1111         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1112                  afid ? afid->fid : -1, uname, aname);
1113         fid = p9_fid_create(clnt);
1114         if (IS_ERR(fid)) {
1115                 err = PTR_ERR(fid);
1116                 fid = NULL;
1117                 goto error;
1118         }
1119
1120         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1121                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1122         if (IS_ERR(req)) {
1123                 err = PTR_ERR(req);
1124                 goto error;
1125         }
1126
1127         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1128         if (err) {
1129                 trace_9p_protocol_dump(clnt, req->rc);
1130                 p9_free_req(clnt, req);
1131                 goto error;
1132         }
1133
1134         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1135                  qid.type, (unsigned long long)qid.path, qid.version);
1136
1137         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1138
1139         p9_free_req(clnt, req);
1140         return fid;
1141
1142 error:
1143         if (fid)
1144                 p9_fid_destroy(fid);
1145         return ERR_PTR(err);
1146 }
1147 EXPORT_SYMBOL(p9_client_attach);
1148
1149 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1150                 char **wnames, int clone)
1151 {
1152         int err;
1153         struct p9_client *clnt;
1154         struct p9_fid *fid;
1155         struct p9_qid *wqids;
1156         struct p9_req_t *req;
1157         uint16_t nwqids, count;
1158
1159         err = 0;
1160         wqids = NULL;
1161         clnt = oldfid->clnt;
1162         if (clone) {
1163                 fid = p9_fid_create(clnt);
1164                 if (IS_ERR(fid)) {
1165                         err = PTR_ERR(fid);
1166                         fid = NULL;
1167                         goto error;
1168                 }
1169
1170                 fid->uid = oldfid->uid;
1171         } else
1172                 fid = oldfid;
1173
1174
1175         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1176                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1177
1178         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1179                                                                 nwname, wnames);
1180         if (IS_ERR(req)) {
1181                 err = PTR_ERR(req);
1182                 goto error;
1183         }
1184
1185         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1186         if (err) {
1187                 trace_9p_protocol_dump(clnt, req->rc);
1188                 p9_free_req(clnt, req);
1189                 goto clunk_fid;
1190         }
1191         p9_free_req(clnt, req);
1192
1193         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1194
1195         if (nwqids != nwname) {
1196                 err = -ENOENT;
1197                 goto clunk_fid;
1198         }
1199
1200         for (count = 0; count < nwqids; count++)
1201                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1202                         count, wqids[count].type,
1203                         (unsigned long long)wqids[count].path,
1204                         wqids[count].version);
1205
1206         if (nwname)
1207                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1208         else
1209                 fid->qid = oldfid->qid;
1210
1211         kfree(wqids);
1212         return fid;
1213
1214 clunk_fid:
1215         kfree(wqids);
1216         p9_client_clunk(fid);
1217         fid = NULL;
1218
1219 error:
1220         if (fid && (fid != oldfid))
1221                 p9_fid_destroy(fid);
1222
1223         return ERR_PTR(err);
1224 }
1225 EXPORT_SYMBOL(p9_client_walk);
1226
1227 int p9_client_open(struct p9_fid *fid, int mode)
1228 {
1229         int err;
1230         struct p9_client *clnt;
1231         struct p9_req_t *req;
1232         struct p9_qid qid;
1233         int iounit;
1234
1235         clnt = fid->clnt;
1236         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1237                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1238         err = 0;
1239
1240         if (fid->mode != -1)
1241                 return -EINVAL;
1242
1243         if (p9_is_proto_dotl(clnt))
1244                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1245         else
1246                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1247         if (IS_ERR(req)) {
1248                 err = PTR_ERR(req);
1249                 goto error;
1250         }
1251
1252         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1253         if (err) {
1254                 trace_9p_protocol_dump(clnt, req->rc);
1255                 goto free_and_error;
1256         }
1257
1258         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1259                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1260                 (unsigned long long)qid.path, qid.version, iounit);
1261
1262         fid->mode = mode;
1263         fid->iounit = iounit;
1264
1265 free_and_error:
1266         p9_free_req(clnt, req);
1267 error:
1268         return err;
1269 }
1270 EXPORT_SYMBOL(p9_client_open);
1271
1272 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1273                 kgid_t gid, struct p9_qid *qid)
1274 {
1275         int err = 0;
1276         struct p9_client *clnt;
1277         struct p9_req_t *req;
1278         int iounit;
1279
1280         p9_debug(P9_DEBUG_9P,
1281                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1282                         ofid->fid, name, flags, mode,
1283                         from_kgid(&init_user_ns, gid));
1284         clnt = ofid->clnt;
1285
1286         if (ofid->mode != -1)
1287                 return -EINVAL;
1288
1289         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1290                         mode, gid);
1291         if (IS_ERR(req)) {
1292                 err = PTR_ERR(req);
1293                 goto error;
1294         }
1295
1296         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1297         if (err) {
1298                 trace_9p_protocol_dump(clnt, req->rc);
1299                 goto free_and_error;
1300         }
1301
1302         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1303                         qid->type,
1304                         (unsigned long long)qid->path,
1305                         qid->version, iounit);
1306
1307         ofid->mode = mode;
1308         ofid->iounit = iounit;
1309
1310 free_and_error:
1311         p9_free_req(clnt, req);
1312 error:
1313         return err;
1314 }
1315 EXPORT_SYMBOL(p9_client_create_dotl);
1316
1317 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1318                      char *extension)
1319 {
1320         int err;
1321         struct p9_client *clnt;
1322         struct p9_req_t *req;
1323         struct p9_qid qid;
1324         int iounit;
1325
1326         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1327                                                 fid->fid, name, perm, mode);
1328         err = 0;
1329         clnt = fid->clnt;
1330
1331         if (fid->mode != -1)
1332                 return -EINVAL;
1333
1334         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1335                                 mode, extension);
1336         if (IS_ERR(req)) {
1337                 err = PTR_ERR(req);
1338                 goto error;
1339         }
1340
1341         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1342         if (err) {
1343                 trace_9p_protocol_dump(clnt, req->rc);
1344                 goto free_and_error;
1345         }
1346
1347         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1348                                 qid.type,
1349                                 (unsigned long long)qid.path,
1350                                 qid.version, iounit);
1351
1352         fid->mode = mode;
1353         fid->iounit = iounit;
1354
1355 free_and_error:
1356         p9_free_req(clnt, req);
1357 error:
1358         return err;
1359 }
1360 EXPORT_SYMBOL(p9_client_fcreate);
1361
1362 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
1363                 struct p9_qid *qid)
1364 {
1365         int err = 0;
1366         struct p9_client *clnt;
1367         struct p9_req_t *req;
1368
1369         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1370                         dfid->fid, name, symtgt);
1371         clnt = dfid->clnt;
1372
1373         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1374                         gid);
1375         if (IS_ERR(req)) {
1376                 err = PTR_ERR(req);
1377                 goto error;
1378         }
1379
1380         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1381         if (err) {
1382                 trace_9p_protocol_dump(clnt, req->rc);
1383                 goto free_and_error;
1384         }
1385
1386         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1387                         qid->type, (unsigned long long)qid->path, qid->version);
1388
1389 free_and_error:
1390         p9_free_req(clnt, req);
1391 error:
1392         return err;
1393 }
1394 EXPORT_SYMBOL(p9_client_symlink);
1395
1396 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1397 {
1398         struct p9_client *clnt;
1399         struct p9_req_t *req;
1400
1401         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1402                         dfid->fid, oldfid->fid, newname);
1403         clnt = dfid->clnt;
1404         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1405                         newname);
1406         if (IS_ERR(req))
1407                 return PTR_ERR(req);
1408
1409         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1410         p9_free_req(clnt, req);
1411         return 0;
1412 }
1413 EXPORT_SYMBOL(p9_client_link);
1414
1415 int p9_client_fsync(struct p9_fid *fid, int datasync)
1416 {
1417         int err;
1418         struct p9_client *clnt;
1419         struct p9_req_t *req;
1420
1421         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1422                         fid->fid, datasync);
1423         err = 0;
1424         clnt = fid->clnt;
1425
1426         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1427         if (IS_ERR(req)) {
1428                 err = PTR_ERR(req);
1429                 goto error;
1430         }
1431
1432         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1433
1434         p9_free_req(clnt, req);
1435
1436 error:
1437         return err;
1438 }
1439 EXPORT_SYMBOL(p9_client_fsync);
1440
1441 int p9_client_clunk(struct p9_fid *fid)
1442 {
1443         int err;
1444         struct p9_client *clnt;
1445         struct p9_req_t *req;
1446         int retries = 0;
1447
1448         if (!fid) {
1449                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1450                         __func__, task_pid_nr(current));
1451                 dump_stack();
1452                 return 0;
1453         }
1454
1455 again:
1456         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1457                                                                 retries);
1458         err = 0;
1459         clnt = fid->clnt;
1460
1461         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1462         if (IS_ERR(req)) {
1463                 err = PTR_ERR(req);
1464                 goto error;
1465         }
1466
1467         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1468
1469         p9_free_req(clnt, req);
1470 error:
1471         /*
1472          * Fid is not valid even after a failed clunk
1473          * If interrupted, retry once then give up and
1474          * leak fid until umount.
1475          */
1476         if (err == -ERESTARTSYS) {
1477                 if (retries++ == 0)
1478                         goto again;
1479         } else
1480                 p9_fid_destroy(fid);
1481         return err;
1482 }
1483 EXPORT_SYMBOL(p9_client_clunk);
1484
1485 int p9_client_remove(struct p9_fid *fid)
1486 {
1487         int err;
1488         struct p9_client *clnt;
1489         struct p9_req_t *req;
1490
1491         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1492         err = 0;
1493         clnt = fid->clnt;
1494
1495         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1496         if (IS_ERR(req)) {
1497                 err = PTR_ERR(req);
1498                 goto error;
1499         }
1500
1501         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1502
1503         p9_free_req(clnt, req);
1504 error:
1505         if (err == -ERESTARTSYS)
1506                 p9_client_clunk(fid);
1507         else
1508                 p9_fid_destroy(fid);
1509         return err;
1510 }
1511 EXPORT_SYMBOL(p9_client_remove);
1512
1513 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1514 {
1515         int err = 0;
1516         struct p9_req_t *req;
1517         struct p9_client *clnt;
1518
1519         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1520                    dfid->fid, name, flags);
1521
1522         clnt = dfid->clnt;
1523         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1524         if (IS_ERR(req)) {
1525                 err = PTR_ERR(req);
1526                 goto error;
1527         }
1528         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1529
1530         p9_free_req(clnt, req);
1531 error:
1532         return err;
1533 }
1534 EXPORT_SYMBOL(p9_client_unlinkat);
1535
1536 int
1537 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1538 {
1539         struct p9_client *clnt = fid->clnt;
1540         struct p9_req_t *req;
1541         int total = 0;
1542
1543         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1544                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1545
1546         while (iov_iter_count(to)) {
1547                 int count = iov_iter_count(to);
1548                 int rsize, non_zc = 0;
1549                 char *dataptr;
1550
1551                 rsize = fid->iounit;
1552                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1553                         rsize = clnt->msize - P9_IOHDRSZ;
1554
1555                 if (count < rsize)
1556                         rsize = count;
1557
1558                 /* Don't bother zerocopy for small IO (< 1024) */
1559                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1560                         /*
1561                          * response header len is 11
1562                          * PDU Header(7) + IO Size (4)
1563                          */
1564                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1565                                                0, 11, "dqd", fid->fid,
1566                                                offset, rsize);
1567                 } else {
1568                         non_zc = 1;
1569                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1570                                             rsize);
1571                 }
1572                 if (IS_ERR(req)) {
1573                         *err = PTR_ERR(req);
1574                         break;
1575                 }
1576
1577                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1578                                    "D", &count, &dataptr);
1579                 if (*err) {
1580                         trace_9p_protocol_dump(clnt, req->rc);
1581                         p9_free_req(clnt, req);
1582                         break;
1583                 }
1584
1585                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1586                 if (!count) {
1587                         p9_free_req(clnt, req);
1588                         break;
1589                 }
1590
1591                 if (non_zc) {
1592                         int n = copy_to_iter(dataptr, count, to);
1593                         total += n;
1594                         offset += n;
1595                         if (n != count) {
1596                                 *err = -EFAULT;
1597                                 p9_free_req(clnt, req);
1598                                 break;
1599                         }
1600                 } else {
1601                         iov_iter_advance(to, count);
1602                         total += count;
1603                         offset += count;
1604                 }
1605                 p9_free_req(clnt, req);
1606         }
1607         return total;
1608 }
1609 EXPORT_SYMBOL(p9_client_read);
1610
1611 int
1612 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1613 {
1614         struct p9_client *clnt = fid->clnt;
1615         struct p9_req_t *req;
1616         int total = 0;
1617
1618         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1619                                 fid->fid, (unsigned long long) offset,
1620                                 iov_iter_count(from));
1621
1622         while (iov_iter_count(from)) {
1623                 int count = iov_iter_count(from);
1624                 int rsize = fid->iounit;
1625                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1626                         rsize = clnt->msize - P9_IOHDRSZ;
1627
1628                 if (count < rsize)
1629                         rsize = count;
1630
1631                 /* Don't bother zerocopy for small IO (< 1024) */
1632                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1633                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1634                                                rsize, P9_ZC_HDR_SZ, "dqd",
1635                                                fid->fid, offset, rsize);
1636                 } else {
1637                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1638                                                     offset, rsize, from);
1639                 }
1640                 if (IS_ERR(req)) {
1641                         *err = PTR_ERR(req);
1642                         break;
1643                 }
1644
1645                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1646                 if (*err) {
1647                         trace_9p_protocol_dump(clnt, req->rc);
1648                         p9_free_req(clnt, req);
1649                 }
1650
1651                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1652
1653                 p9_free_req(clnt, req);
1654                 iov_iter_advance(from, count);
1655                 total += count;
1656                 offset += count;
1657         }
1658         return total;
1659 }
1660 EXPORT_SYMBOL(p9_client_write);
1661
1662 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1663 {
1664         int err;
1665         struct p9_client *clnt;
1666         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1667         struct p9_req_t *req;
1668         u16 ignored;
1669
1670         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1671
1672         if (!ret)
1673                 return ERR_PTR(-ENOMEM);
1674
1675         err = 0;
1676         clnt = fid->clnt;
1677
1678         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1679         if (IS_ERR(req)) {
1680                 err = PTR_ERR(req);
1681                 goto error;
1682         }
1683
1684         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1685         if (err) {
1686                 trace_9p_protocol_dump(clnt, req->rc);
1687                 p9_free_req(clnt, req);
1688                 goto error;
1689         }
1690
1691         p9_debug(P9_DEBUG_9P,
1692                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1693                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1694                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1695                 "<<<    uid=%d gid=%d n_muid=%d\n",
1696                 ret->size, ret->type, ret->dev, ret->qid.type,
1697                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1698                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1699                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1700                 from_kuid(&init_user_ns, ret->n_uid),
1701                 from_kgid(&init_user_ns, ret->n_gid),
1702                 from_kuid(&init_user_ns, ret->n_muid));
1703
1704         p9_free_req(clnt, req);
1705         return ret;
1706
1707 error:
1708         kfree(ret);
1709         return ERR_PTR(err);
1710 }
1711 EXPORT_SYMBOL(p9_client_stat);
1712
1713 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1714                                                         u64 request_mask)
1715 {
1716         int err;
1717         struct p9_client *clnt;
1718         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1719                                                                 GFP_KERNEL);
1720         struct p9_req_t *req;
1721
1722         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1723                                                         fid->fid, request_mask);
1724
1725         if (!ret)
1726                 return ERR_PTR(-ENOMEM);
1727
1728         err = 0;
1729         clnt = fid->clnt;
1730
1731         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1732         if (IS_ERR(req)) {
1733                 err = PTR_ERR(req);
1734                 goto error;
1735         }
1736
1737         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1738         if (err) {
1739                 trace_9p_protocol_dump(clnt, req->rc);
1740                 p9_free_req(clnt, req);
1741                 goto error;
1742         }
1743
1744         p9_debug(P9_DEBUG_9P,
1745                 "<<< RGETATTR st_result_mask=%lld\n"
1746                 "<<< qid=%x.%llx.%x\n"
1747                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1748                 "<<< st_uid=%d st_gid=%d\n"
1749                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1750                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1751                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1752                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1753                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1754                 "<<< st_gen=%lld st_data_version=%lld",
1755                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1756                 ret->qid.version, ret->st_mode, ret->st_nlink,
1757                 from_kuid(&init_user_ns, ret->st_uid),
1758                 from_kgid(&init_user_ns, ret->st_gid),
1759                 ret->st_rdev, ret->st_size, ret->st_blksize,
1760                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1761                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1762                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1763                 ret->st_gen, ret->st_data_version);
1764
1765         p9_free_req(clnt, req);
1766         return ret;
1767
1768 error:
1769         kfree(ret);
1770         return ERR_PTR(err);
1771 }
1772 EXPORT_SYMBOL(p9_client_getattr_dotl);
1773
1774 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1775 {
1776         int ret;
1777
1778         /* NOTE: size shouldn't include its own length */
1779         /* size[2] type[2] dev[4] qid[13] */
1780         /* mode[4] atime[4] mtime[4] length[8]*/
1781         /* name[s] uid[s] gid[s] muid[s] */
1782         ret = 2+4+13+4+4+4+8+2+2+2+2;
1783
1784         if (wst->name)
1785                 ret += strlen(wst->name);
1786         if (wst->uid)
1787                 ret += strlen(wst->uid);
1788         if (wst->gid)
1789                 ret += strlen(wst->gid);
1790         if (wst->muid)
1791                 ret += strlen(wst->muid);
1792
1793         if ((proto_version == p9_proto_2000u) ||
1794                 (proto_version == p9_proto_2000L)) {
1795                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1796                 if (wst->extension)
1797                         ret += strlen(wst->extension);
1798         }
1799
1800         return ret;
1801 }
1802
1803 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1804 {
1805         int err;
1806         struct p9_req_t *req;
1807         struct p9_client *clnt;
1808
1809         err = 0;
1810         clnt = fid->clnt;
1811         wst->size = p9_client_statsize(wst, clnt->proto_version);
1812         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1813         p9_debug(P9_DEBUG_9P,
1814                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1815                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1816                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1817                 "     uid=%d gid=%d n_muid=%d\n",
1818                 wst->size, wst->type, wst->dev, wst->qid.type,
1819                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1820                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1821                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1822                 from_kuid(&init_user_ns, wst->n_uid),
1823                 from_kgid(&init_user_ns, wst->n_gid),
1824                 from_kuid(&init_user_ns, wst->n_muid));
1825
1826         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1827         if (IS_ERR(req)) {
1828                 err = PTR_ERR(req);
1829                 goto error;
1830         }
1831
1832         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1833
1834         p9_free_req(clnt, req);
1835 error:
1836         return err;
1837 }
1838 EXPORT_SYMBOL(p9_client_wstat);
1839
1840 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1841 {
1842         int err;
1843         struct p9_req_t *req;
1844         struct p9_client *clnt;
1845
1846         err = 0;
1847         clnt = fid->clnt;
1848         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1849         p9_debug(P9_DEBUG_9P,
1850                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1851                 "    atime_sec=%lld atime_nsec=%lld\n"
1852                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1853                 p9attr->valid, p9attr->mode,
1854                 from_kuid(&init_user_ns, p9attr->uid),
1855                 from_kgid(&init_user_ns, p9attr->gid),
1856                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1857                 p9attr->mtime_sec, p9attr->mtime_nsec);
1858
1859         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1860
1861         if (IS_ERR(req)) {
1862                 err = PTR_ERR(req);
1863                 goto error;
1864         }
1865         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1866         p9_free_req(clnt, req);
1867 error:
1868         return err;
1869 }
1870 EXPORT_SYMBOL(p9_client_setattr);
1871
1872 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1873 {
1874         int err;
1875         struct p9_req_t *req;
1876         struct p9_client *clnt;
1877
1878         err = 0;
1879         clnt = fid->clnt;
1880
1881         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1882
1883         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1884         if (IS_ERR(req)) {
1885                 err = PTR_ERR(req);
1886                 goto error;
1887         }
1888
1889         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1890                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1891                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1892         if (err) {
1893                 trace_9p_protocol_dump(clnt, req->rc);
1894                 p9_free_req(clnt, req);
1895                 goto error;
1896         }
1897
1898         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1899                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1900                 "fsid %llu namelen %ld\n",
1901                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1902                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1903                 sb->fsid, (long int)sb->namelen);
1904
1905         p9_free_req(clnt, req);
1906 error:
1907         return err;
1908 }
1909 EXPORT_SYMBOL(p9_client_statfs);
1910
1911 int p9_client_rename(struct p9_fid *fid,
1912                      struct p9_fid *newdirfid, const char *name)
1913 {
1914         int err;
1915         struct p9_req_t *req;
1916         struct p9_client *clnt;
1917
1918         err = 0;
1919         clnt = fid->clnt;
1920
1921         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1922                         fid->fid, newdirfid->fid, name);
1923
1924         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1925                         newdirfid->fid, name);
1926         if (IS_ERR(req)) {
1927                 err = PTR_ERR(req);
1928                 goto error;
1929         }
1930
1931         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1932
1933         p9_free_req(clnt, req);
1934 error:
1935         return err;
1936 }
1937 EXPORT_SYMBOL(p9_client_rename);
1938
1939 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1940                        struct p9_fid *newdirfid, const char *new_name)
1941 {
1942         int err;
1943         struct p9_req_t *req;
1944         struct p9_client *clnt;
1945
1946         err = 0;
1947         clnt = olddirfid->clnt;
1948
1949         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1950                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1951                    newdirfid->fid, new_name);
1952
1953         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1954                             old_name, newdirfid->fid, new_name);
1955         if (IS_ERR(req)) {
1956                 err = PTR_ERR(req);
1957                 goto error;
1958         }
1959
1960         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1961                    newdirfid->fid, new_name);
1962
1963         p9_free_req(clnt, req);
1964 error:
1965         return err;
1966 }
1967 EXPORT_SYMBOL(p9_client_renameat);
1968
1969 /*
1970  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1971  */
1972 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1973                                 const char *attr_name, u64 *attr_size)
1974 {
1975         int err;
1976         struct p9_req_t *req;
1977         struct p9_client *clnt;
1978         struct p9_fid *attr_fid;
1979
1980         err = 0;
1981         clnt = file_fid->clnt;
1982         attr_fid = p9_fid_create(clnt);
1983         if (IS_ERR(attr_fid)) {
1984                 err = PTR_ERR(attr_fid);
1985                 attr_fid = NULL;
1986                 goto error;
1987         }
1988         p9_debug(P9_DEBUG_9P,
1989                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1990                 file_fid->fid, attr_fid->fid, attr_name);
1991
1992         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1993                         file_fid->fid, attr_fid->fid, attr_name);
1994         if (IS_ERR(req)) {
1995                 err = PTR_ERR(req);
1996                 goto error;
1997         }
1998         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
1999         if (err) {
2000                 trace_9p_protocol_dump(clnt, req->rc);
2001                 p9_free_req(clnt, req);
2002                 goto clunk_fid;
2003         }
2004         p9_free_req(clnt, req);
2005         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2006                 attr_fid->fid, *attr_size);
2007         return attr_fid;
2008 clunk_fid:
2009         p9_client_clunk(attr_fid);
2010         attr_fid = NULL;
2011 error:
2012         if (attr_fid && (attr_fid != file_fid))
2013                 p9_fid_destroy(attr_fid);
2014
2015         return ERR_PTR(err);
2016 }
2017 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2018
2019 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2020                         u64 attr_size, int flags)
2021 {
2022         int err;
2023         struct p9_req_t *req;
2024         struct p9_client *clnt;
2025
2026         p9_debug(P9_DEBUG_9P,
2027                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2028                 fid->fid, name, (long long)attr_size, flags);
2029         err = 0;
2030         clnt = fid->clnt;
2031         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2032                         fid->fid, name, attr_size, flags);
2033         if (IS_ERR(req)) {
2034                 err = PTR_ERR(req);
2035                 goto error;
2036         }
2037         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2038         p9_free_req(clnt, req);
2039 error:
2040         return err;
2041 }
2042 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2043
2044 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2045 {
2046         int err, rsize, non_zc = 0;
2047         struct p9_client *clnt;
2048         struct p9_req_t *req;
2049         char *dataptr;
2050         struct kvec kv = {.iov_base = data, .iov_len = count};
2051         struct iov_iter to;
2052
2053         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2054
2055         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2056                                 fid->fid, (unsigned long long) offset, count);
2057
2058         err = 0;
2059         clnt = fid->clnt;
2060
2061         rsize = fid->iounit;
2062         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2063                 rsize = clnt->msize - P9_READDIRHDRSZ;
2064
2065         if (count < rsize)
2066                 rsize = count;
2067
2068         /* Don't bother zerocopy for small IO (< 1024) */
2069         if (clnt->trans_mod->zc_request && rsize > 1024) {
2070                 /*
2071                  * response header len is 11
2072                  * PDU Header(7) + IO Size (4)
2073                  */
2074                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2075                                        11, "dqd", fid->fid, offset, rsize);
2076         } else {
2077                 non_zc = 1;
2078                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2079                                     offset, rsize);
2080         }
2081         if (IS_ERR(req)) {
2082                 err = PTR_ERR(req);
2083                 goto error;
2084         }
2085
2086         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2087         if (err) {
2088                 trace_9p_protocol_dump(clnt, req->rc);
2089                 goto free_and_error;
2090         }
2091
2092         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2093
2094         if (non_zc)
2095                 memmove(data, dataptr, count);
2096
2097         p9_free_req(clnt, req);
2098         return count;
2099
2100 free_and_error:
2101         p9_free_req(clnt, req);
2102 error:
2103         return err;
2104 }
2105 EXPORT_SYMBOL(p9_client_readdir);
2106
2107 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2108                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2109 {
2110         int err;
2111         struct p9_client *clnt;
2112         struct p9_req_t *req;
2113
2114         err = 0;
2115         clnt = fid->clnt;
2116         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2117                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2118         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2119                 MAJOR(rdev), MINOR(rdev), gid);
2120         if (IS_ERR(req))
2121                 return PTR_ERR(req);
2122
2123         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2124         if (err) {
2125                 trace_9p_protocol_dump(clnt, req->rc);
2126                 goto error;
2127         }
2128         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2129                                 (unsigned long long)qid->path, qid->version);
2130
2131 error:
2132         p9_free_req(clnt, req);
2133         return err;
2134
2135 }
2136 EXPORT_SYMBOL(p9_client_mknod_dotl);
2137
2138 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2139                                 kgid_t gid, struct p9_qid *qid)
2140 {
2141         int err;
2142         struct p9_client *clnt;
2143         struct p9_req_t *req;
2144
2145         err = 0;
2146         clnt = fid->clnt;
2147         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2148                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2149         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2150                 gid);
2151         if (IS_ERR(req))
2152                 return PTR_ERR(req);
2153
2154         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2155         if (err) {
2156                 trace_9p_protocol_dump(clnt, req->rc);
2157                 goto error;
2158         }
2159         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2160                                 (unsigned long long)qid->path, qid->version);
2161
2162 error:
2163         p9_free_req(clnt, req);
2164         return err;
2165
2166 }
2167 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2168
2169 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2170 {
2171         int err;
2172         struct p9_client *clnt;
2173         struct p9_req_t *req;
2174
2175         err = 0;
2176         clnt = fid->clnt;
2177         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2178                         "start %lld length %lld proc_id %d client_id %s\n",
2179                         fid->fid, flock->type, flock->flags, flock->start,
2180                         flock->length, flock->proc_id, flock->client_id);
2181
2182         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2183                                 flock->flags, flock->start, flock->length,
2184                                         flock->proc_id, flock->client_id);
2185
2186         if (IS_ERR(req))
2187                 return PTR_ERR(req);
2188
2189         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2190         if (err) {
2191                 trace_9p_protocol_dump(clnt, req->rc);
2192                 goto error;
2193         }
2194         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2195 error:
2196         p9_free_req(clnt, req);
2197         return err;
2198
2199 }
2200 EXPORT_SYMBOL(p9_client_lock_dotl);
2201
2202 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2203 {
2204         int err;
2205         struct p9_client *clnt;
2206         struct p9_req_t *req;
2207
2208         err = 0;
2209         clnt = fid->clnt;
2210         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2211                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2212                 glock->start, glock->length, glock->proc_id, glock->client_id);
2213
2214         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2215                 glock->start, glock->length, glock->proc_id, glock->client_id);
2216
2217         if (IS_ERR(req))
2218                 return PTR_ERR(req);
2219
2220         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2221                         &glock->start, &glock->length, &glock->proc_id,
2222                         &glock->client_id);
2223         if (err) {
2224                 trace_9p_protocol_dump(clnt, req->rc);
2225                 goto error;
2226         }
2227         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2228                 "proc_id %d client_id %s\n", glock->type, glock->start,
2229                 glock->length, glock->proc_id, glock->client_id);
2230 error:
2231         p9_free_req(clnt, req);
2232         return err;
2233 }
2234 EXPORT_SYMBOL(p9_client_getlock_dotl);
2235
2236 int p9_client_readlink(struct p9_fid *fid, char **target)
2237 {
2238         int err;
2239         struct p9_client *clnt;
2240         struct p9_req_t *req;
2241
2242         err = 0;
2243         clnt = fid->clnt;
2244         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2245
2246         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2247         if (IS_ERR(req))
2248                 return PTR_ERR(req);
2249
2250         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2251         if (err) {
2252                 trace_9p_protocol_dump(clnt, req->rc);
2253                 goto error;
2254         }
2255         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2256 error:
2257         p9_free_req(clnt, req);
2258         return err;
2259 }
2260 EXPORT_SYMBOL(p9_client_readlink);