net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/poll.h>
  32 #include <linux/idr.h>
  33 #include <linux/mutex.h>
  34 #include <linux/slab.h>
  35 #include <linux/sched/signal.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/uio.h>
  38 #include <net/9p/9p.h>
  39 #include <linux/parser.h>
  40 #include <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) && ecode < 512)
 522                         err = -ecode;
 523
 524                 if (!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                         if (!copy_from_iter_full(ename + inline_len,
 596                                              len - inline_len, uidata)) {
 597                                 err = -EFAULT;
 598                                 goto out_err;
 599                         }
 600                 }
 601                 ename = NULL;
 602                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 603                                   &ename, &ecode);
 604                 if (err)
 605                         goto out_err;
 606
 607                 if (p9_is_proto_dotu(c) && ecode < 512)
 608                         err = -ecode;
 609
 610                 if (!err) {
 611                         err = p9_errstr2errno(ename, strlen(ename));
 612
 613                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 614                                  -ecode, ename);
 615                 }
 616                 kfree(ename);
 617         } else {
 618                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 619                 err = -ecode;
 620
 621                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 622         }
 623         return err;
 624
 625 out_err:
 626         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 627         return err;
 628 }
 629
 630 static struct p9_req_t *
 631 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 632
 633 /**
 634  * p9_client_flush - flush (cancel) a request
 635  * @c: client state
 636  * @oldreq: request to cancel
 637  *
 638  * This sents a flush for a particular request and links
 639  * the flush request to the original request.  The current
 640  * code only supports a single flush request although the protocol
 641  * allows for multiple flush requests to be sent for a single request.
 642  *
 643  */
 644
 645 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 646 {
 647         struct p9_req_t *req;
 648         int16_t oldtag;
 649         int err;
 650
 651         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 652         if (err)
 653                 return err;
 654
 655         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 656
 657         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 658         if (IS_ERR(req))
 659                 return PTR_ERR(req);
 660
 661         /*
 662          * if we haven't received a response for oldreq,
 663          * remove it from the list
 664          */
 665         if (oldreq->status == REQ_STATUS_SENT)
 666                 if (c->trans_mod->cancelled)
 667                         c->trans_mod->cancelled(c, oldreq);
 668
 669         p9_free_req(c, req);
 670         return 0;
 671 }
 672
 673 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 674                                               int8_t type, int req_size,
 675                                               const char *fmt, va_list ap)
 676 {
 677         int tag, err;
 678         struct p9_req_t *req;
 679
 680         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 681
 682         /* we allow for any status other than disconnected */
 683         if (c->status == Disconnected)
 684                 return ERR_PTR(-EIO);
 685
 686         /* if status is begin_disconnected we allow only clunk request */
 687         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 688                 return ERR_PTR(-EIO);
 689
 690         tag = P9_NOTAG;
 691         if (type != P9_TVERSION) {
 692                 tag = p9_idpool_get(c->tagpool);
 693                 if (tag < 0)
 694                         return ERR_PTR(-ENOMEM);
 695         }
 696
 697         req = p9_tag_alloc(c, tag, req_size);
 698         if (IS_ERR(req))
 699                 return req;
 700
 701         /* marshall the data */
 702         p9pdu_prepare(req->tc, tag, type);
 703         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 704         if (err)
 705                 goto reterr;
 706         p9pdu_finalize(c, req->tc);
 707         trace_9p_client_req(c, type, tag);
 708         return req;
 709 reterr:
 710         p9_free_req(c, req);
 711         return ERR_PTR(err);
 712 }
 713
 714 /**
 715  * p9_client_rpc - issue a request and wait for a response
 716  * @c: client session
 717  * @type: type of request
 718  * @fmt: protocol format string (see protocol.c)
 719  *
 720  * Returns request structure (which client must free using p9_free_req)
 721  */
 722
 723 static struct p9_req_t *
 724 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 725 {
 726         va_list ap;
 727         int sigpending, err;
 728         unsigned long flags;
 729         struct p9_req_t *req;
 730
 731         va_start(ap, fmt);
 732         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 733         va_end(ap);
 734         if (IS_ERR(req))
 735                 return req;
 736
 737         if (signal_pending(current)) {
 738                 sigpending = 1;
 739                 clear_thread_flag(TIF_SIGPENDING);
 740         } else
 741                 sigpending = 0;
 742
 743         err = c->trans_mod->request(c, req);
 744         if (err < 0) {
 745                 if (err != -ERESTARTSYS && err != -EFAULT)
 746                         c->status = Disconnected;
 747                 goto reterr;
 748         }
 749 again:
 750         /* Wait for the response */
 751         err = wait_event_interruptible(*req->wq,
 752                                        req->status >= REQ_STATUS_RCVD);
 753
 754         /*
 755          * Make sure our req is coherent with regard to updates in other
 756          * threads - echoes to wmb() in the callback
 757          */
 758         smp_rmb();
 759
 760         if ((err == -ERESTARTSYS) && (c->status == Connected)
 761                                   && (type == P9_TFLUSH)) {
 762                 sigpending = 1;
 763                 clear_thread_flag(TIF_SIGPENDING);
 764                 goto again;
 765         }
 766
 767         if (req->status == REQ_STATUS_ERROR) {
 768                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 769                 err = req->t_err;
 770         }
 771         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 772                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 773                 sigpending = 1;
 774                 clear_thread_flag(TIF_SIGPENDING);
 775
 776                 if (c->trans_mod->cancel(c, req))
 777                         p9_client_flush(c, req);
 778
 779                 /* if we received the response anyway, don't signal error */
 780                 if (req->status == REQ_STATUS_RCVD)
 781                         err = 0;
 782         }
 783         if (sigpending) {
 784                 spin_lock_irqsave(&current->sighand->siglock, flags);
 785                 recalc_sigpending();
 786                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 787         }
 788         if (err < 0)
 789                 goto reterr;
 790
 791         err = p9_check_errors(c, req);
 792         trace_9p_client_res(c, type, req->rc->tag, err);
 793         if (!err)
 794                 return req;
 795 reterr:
 796         p9_free_req(c, req);
 797         return ERR_PTR(safe_errno(err));
 798 }
 799
 800 /**
 801  * p9_client_zc_rpc - issue a request and wait for a response
 802  * @c: client session
 803  * @type: type of request
 804  * @uidata: destination for zero copy read
 805  * @uodata: source for zero copy write
 806  * @inlen: read buffer size
 807  * @olen: write buffer size
 808  * @hdrlen: reader header size, This is the size of response protocol data
 809  * @fmt: protocol format string (see protocol.c)
 810  *
 811  * Returns request structure (which client must free using p9_free_req)
 812  */
 813 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 814                                          struct iov_iter *uidata,
 815                                          struct iov_iter *uodata,
 816                                          int inlen, int olen, int in_hdrlen,
 817                                          const char *fmt, ...)
 818 {
 819         va_list ap;
 820         int sigpending, err;
 821         unsigned long flags;
 822         struct p9_req_t *req;
 823
 824         va_start(ap, fmt);
 825         /*
 826          * We allocate a inline protocol data of only 4k bytes.
 827          * The actual content is passed in zero-copy fashion.
 828          */
 829         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 830         va_end(ap);
 831         if (IS_ERR(req))
 832                 return req;
 833
 834         if (signal_pending(current)) {
 835                 sigpending = 1;
 836                 clear_thread_flag(TIF_SIGPENDING);
 837         } else
 838                 sigpending = 0;
 839
 840         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 841                                        inlen, olen, in_hdrlen);
 842         if (err < 0) {
 843                 if (err == -EIO)
 844                         c->status = Disconnected;
 845                 if (err != -ERESTARTSYS)
 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         const char *uname, kuid_t n_uname, const 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         fid->uid = n_uname;
1120
1121         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1122                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1123         if (IS_ERR(req)) {
1124                 err = PTR_ERR(req);
1125                 goto error;
1126         }
1127
1128         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1129         if (err) {
1130                 trace_9p_protocol_dump(clnt, req->rc);
1131                 p9_free_req(clnt, req);
1132                 goto error;
1133         }
1134
1135         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1136                  qid.type, (unsigned long long)qid.path, qid.version);
1137
1138         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1139
1140         p9_free_req(clnt, req);
1141         return fid;
1142
1143 error:
1144         if (fid)
1145                 p9_fid_destroy(fid);
1146         return ERR_PTR(err);
1147 }
1148 EXPORT_SYMBOL(p9_client_attach);
1149
1150 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1151                 const unsigned char * const *wnames, int clone)
1152 {
1153         int err;
1154         struct p9_client *clnt;
1155         struct p9_fid *fid;
1156         struct p9_qid *wqids;
1157         struct p9_req_t *req;
1158         uint16_t nwqids, count;
1159
1160         err = 0;
1161         wqids = NULL;
1162         clnt = oldfid->clnt;
1163         if (clone) {
1164                 fid = p9_fid_create(clnt);
1165                 if (IS_ERR(fid)) {
1166                         err = PTR_ERR(fid);
1167                         fid = NULL;
1168                         goto error;
1169                 }
1170
1171                 fid->uid = oldfid->uid;
1172         } else
1173                 fid = oldfid;
1174
1175
1176         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1177                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1178
1179         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1180                                                                 nwname, wnames);
1181         if (IS_ERR(req)) {
1182                 err = PTR_ERR(req);
1183                 goto error;
1184         }
1185
1186         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1187         if (err) {
1188                 trace_9p_protocol_dump(clnt, req->rc);
1189                 p9_free_req(clnt, req);
1190                 goto clunk_fid;
1191         }
1192         p9_free_req(clnt, req);
1193
1194         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1195
1196         if (nwqids != nwname) {
1197                 err = -ENOENT;
1198                 goto clunk_fid;
1199         }
1200
1201         for (count = 0; count < nwqids; count++)
1202                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1203                         count, wqids[count].type,
1204                         (unsigned long long)wqids[count].path,
1205                         wqids[count].version);
1206
1207         if (nwname)
1208                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1209         else
1210                 fid->qid = oldfid->qid;
1211
1212         kfree(wqids);
1213         return fid;
1214
1215 clunk_fid:
1216         kfree(wqids);
1217         p9_client_clunk(fid);
1218         fid = NULL;
1219
1220 error:
1221         if (fid && (fid != oldfid))
1222                 p9_fid_destroy(fid);
1223
1224         return ERR_PTR(err);
1225 }
1226 EXPORT_SYMBOL(p9_client_walk);
1227
1228 int p9_client_open(struct p9_fid *fid, int mode)
1229 {
1230         int err;
1231         struct p9_client *clnt;
1232         struct p9_req_t *req;
1233         struct p9_qid qid;
1234         int iounit;
1235
1236         clnt = fid->clnt;
1237         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1238                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1239         err = 0;
1240
1241         if (fid->mode != -1)
1242                 return -EINVAL;
1243
1244         if (p9_is_proto_dotl(clnt))
1245                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1246         else
1247                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1248         if (IS_ERR(req)) {
1249                 err = PTR_ERR(req);
1250                 goto error;
1251         }
1252
1253         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1254         if (err) {
1255                 trace_9p_protocol_dump(clnt, req->rc);
1256                 goto free_and_error;
1257         }
1258
1259         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1260                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1261                 (unsigned long long)qid.path, qid.version, iounit);
1262
1263         fid->mode = mode;
1264         fid->iounit = iounit;
1265
1266 free_and_error:
1267         p9_free_req(clnt, req);
1268 error:
1269         return err;
1270 }
1271 EXPORT_SYMBOL(p9_client_open);
1272
1273 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1274                 kgid_t gid, struct p9_qid *qid)
1275 {
1276         int err = 0;
1277         struct p9_client *clnt;
1278         struct p9_req_t *req;
1279         int iounit;
1280
1281         p9_debug(P9_DEBUG_9P,
1282                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1283                         ofid->fid, name, flags, mode,
1284                         from_kgid(&init_user_ns, gid));
1285         clnt = ofid->clnt;
1286
1287         if (ofid->mode != -1)
1288                 return -EINVAL;
1289
1290         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1291                         mode, gid);
1292         if (IS_ERR(req)) {
1293                 err = PTR_ERR(req);
1294                 goto error;
1295         }
1296
1297         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1298         if (err) {
1299                 trace_9p_protocol_dump(clnt, req->rc);
1300                 goto free_and_error;
1301         }
1302
1303         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1304                         qid->type,
1305                         (unsigned long long)qid->path,
1306                         qid->version, iounit);
1307
1308         ofid->mode = mode;
1309         ofid->iounit = iounit;
1310
1311 free_and_error:
1312         p9_free_req(clnt, req);
1313 error:
1314         return err;
1315 }
1316 EXPORT_SYMBOL(p9_client_create_dotl);
1317
1318 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1319                      char *extension)
1320 {
1321         int err;
1322         struct p9_client *clnt;
1323         struct p9_req_t *req;
1324         struct p9_qid qid;
1325         int iounit;
1326
1327         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1328                                                 fid->fid, name, perm, mode);
1329         err = 0;
1330         clnt = fid->clnt;
1331
1332         if (fid->mode != -1)
1333                 return -EINVAL;
1334
1335         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1336                                 mode, extension);
1337         if (IS_ERR(req)) {
1338                 err = PTR_ERR(req);
1339                 goto error;
1340         }
1341
1342         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1343         if (err) {
1344                 trace_9p_protocol_dump(clnt, req->rc);
1345                 goto free_and_error;
1346         }
1347
1348         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1349                                 qid.type,
1350                                 (unsigned long long)qid.path,
1351                                 qid.version, iounit);
1352
1353         fid->mode = mode;
1354         fid->iounit = iounit;
1355
1356 free_and_error:
1357         p9_free_req(clnt, req);
1358 error:
1359         return err;
1360 }
1361 EXPORT_SYMBOL(p9_client_fcreate);
1362
1363 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1364                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1365 {
1366         int err = 0;
1367         struct p9_client *clnt;
1368         struct p9_req_t *req;
1369
1370         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1371                         dfid->fid, name, symtgt);
1372         clnt = dfid->clnt;
1373
1374         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1375                         gid);
1376         if (IS_ERR(req)) {
1377                 err = PTR_ERR(req);
1378                 goto error;
1379         }
1380
1381         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1382         if (err) {
1383                 trace_9p_protocol_dump(clnt, req->rc);
1384                 goto free_and_error;
1385         }
1386
1387         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1388                         qid->type, (unsigned long long)qid->path, qid->version);
1389
1390 free_and_error:
1391         p9_free_req(clnt, req);
1392 error:
1393         return err;
1394 }
1395 EXPORT_SYMBOL(p9_client_symlink);
1396
1397 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1398 {
1399         struct p9_client *clnt;
1400         struct p9_req_t *req;
1401
1402         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1403                         dfid->fid, oldfid->fid, newname);
1404         clnt = dfid->clnt;
1405         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1406                         newname);
1407         if (IS_ERR(req))
1408                 return PTR_ERR(req);
1409
1410         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1411         p9_free_req(clnt, req);
1412         return 0;
1413 }
1414 EXPORT_SYMBOL(p9_client_link);
1415
1416 int p9_client_fsync(struct p9_fid *fid, int datasync)
1417 {
1418         int err;
1419         struct p9_client *clnt;
1420         struct p9_req_t *req;
1421
1422         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1423                         fid->fid, datasync);
1424         err = 0;
1425         clnt = fid->clnt;
1426
1427         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1428         if (IS_ERR(req)) {
1429                 err = PTR_ERR(req);
1430                 goto error;
1431         }
1432
1433         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1434
1435         p9_free_req(clnt, req);
1436
1437 error:
1438         return err;
1439 }
1440 EXPORT_SYMBOL(p9_client_fsync);
1441
1442 int p9_client_clunk(struct p9_fid *fid)
1443 {
1444         int err;
1445         struct p9_client *clnt;
1446         struct p9_req_t *req;
1447         int retries = 0;
1448
1449         if (!fid) {
1450                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1451                         __func__, task_pid_nr(current));
1452                 dump_stack();
1453                 return 0;
1454         }
1455
1456 again:
1457         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1458                                                                 retries);
1459         err = 0;
1460         clnt = fid->clnt;
1461
1462         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1463         if (IS_ERR(req)) {
1464                 err = PTR_ERR(req);
1465                 goto error;
1466         }
1467
1468         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1469
1470         p9_free_req(clnt, req);
1471 error:
1472         /*
1473          * Fid is not valid even after a failed clunk
1474          * If interrupted, retry once then give up and
1475          * leak fid until umount.
1476          */
1477         if (err == -ERESTARTSYS) {
1478                 if (retries++ == 0)
1479                         goto again;
1480         } else
1481                 p9_fid_destroy(fid);
1482         return err;
1483 }
1484 EXPORT_SYMBOL(p9_client_clunk);
1485
1486 int p9_client_remove(struct p9_fid *fid)
1487 {
1488         int err;
1489         struct p9_client *clnt;
1490         struct p9_req_t *req;
1491
1492         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1493         err = 0;
1494         clnt = fid->clnt;
1495
1496         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1497         if (IS_ERR(req)) {
1498                 err = PTR_ERR(req);
1499                 goto error;
1500         }
1501
1502         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1503
1504         p9_free_req(clnt, req);
1505 error:
1506         if (err == -ERESTARTSYS)
1507                 p9_client_clunk(fid);
1508         else
1509                 p9_fid_destroy(fid);
1510         return err;
1511 }
1512 EXPORT_SYMBOL(p9_client_remove);
1513
1514 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1515 {
1516         int err = 0;
1517         struct p9_req_t *req;
1518         struct p9_client *clnt;
1519
1520         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1521                    dfid->fid, name, flags);
1522
1523         clnt = dfid->clnt;
1524         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1525         if (IS_ERR(req)) {
1526                 err = PTR_ERR(req);
1527                 goto error;
1528         }
1529         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1530
1531         p9_free_req(clnt, req);
1532 error:
1533         return err;
1534 }
1535 EXPORT_SYMBOL(p9_client_unlinkat);
1536
1537 int
1538 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1539 {
1540         struct p9_client *clnt = fid->clnt;
1541         struct p9_req_t *req;
1542         int total = 0;
1543         *err = 0;
1544
1545         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1546                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1547
1548         while (iov_iter_count(to)) {
1549                 int count = iov_iter_count(to);
1550                 int rsize, non_zc = 0;
1551                 char *dataptr;
1552
1553                 rsize = fid->iounit;
1554                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1555                         rsize = clnt->msize - P9_IOHDRSZ;
1556
1557                 if (count < rsize)
1558                         rsize = count;
1559
1560                 /* Don't bother zerocopy for small IO (< 1024) */
1561                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1562                         /*
1563                          * response header len is 11
1564                          * PDU Header(7) + IO Size (4)
1565                          */
1566                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1567                                                0, 11, "dqd", fid->fid,
1568                                                offset, rsize);
1569                 } else {
1570                         non_zc = 1;
1571                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1572                                             rsize);
1573                 }
1574                 if (IS_ERR(req)) {
1575                         *err = PTR_ERR(req);
1576                         break;
1577                 }
1578
1579                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1580                                    "D", &count, &dataptr);
1581                 if (*err) {
1582                         trace_9p_protocol_dump(clnt, req->rc);
1583                         p9_free_req(clnt, req);
1584                         break;
1585                 }
1586                 if (rsize < count) {
1587                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1588                         count = rsize;
1589                 }
1590
1591                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1592                 if (!count) {
1593                         p9_free_req(clnt, req);
1594                         break;
1595                 }
1596
1597                 if (non_zc) {
1598                         int n = copy_to_iter(dataptr, count, to);
1599                         total += n;
1600                         offset += n;
1601                         if (n != count) {
1602                                 *err = -EFAULT;
1603                                 p9_free_req(clnt, req);
1604                                 break;
1605                         }
1606                 } else {
1607                         iov_iter_advance(to, count);
1608                         total += count;
1609                         offset += count;
1610                 }
1611                 p9_free_req(clnt, req);
1612         }
1613         return total;
1614 }
1615 EXPORT_SYMBOL(p9_client_read);
1616
1617 int
1618 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1619 {
1620         struct p9_client *clnt = fid->clnt;
1621         struct p9_req_t *req;
1622         int total = 0;
1623         *err = 0;
1624
1625         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1626                                 fid->fid, (unsigned long long) offset,
1627                                 iov_iter_count(from));
1628
1629         while (iov_iter_count(from)) {
1630                 int count = iov_iter_count(from);
1631                 int rsize = fid->iounit;
1632                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1633                         rsize = clnt->msize - P9_IOHDRSZ;
1634
1635                 if (count < rsize)
1636                         rsize = count;
1637
1638                 /* Don't bother zerocopy for small IO (< 1024) */
1639                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1640                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1641                                                rsize, P9_ZC_HDR_SZ, "dqd",
1642                                                fid->fid, offset, rsize);
1643                 } else {
1644                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1645                                                     offset, rsize, from);
1646                 }
1647                 if (IS_ERR(req)) {
1648                         *err = PTR_ERR(req);
1649                         break;
1650                 }
1651
1652                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1653                 if (*err) {
1654                         trace_9p_protocol_dump(clnt, req->rc);
1655                         p9_free_req(clnt, req);
1656                         break;
1657                 }
1658                 if (rsize < count) {
1659                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1660                         count = rsize;
1661                 }
1662
1663                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1664
1665                 p9_free_req(clnt, req);
1666                 iov_iter_advance(from, count);
1667                 total += count;
1668                 offset += count;
1669         }
1670         return total;
1671 }
1672 EXPORT_SYMBOL(p9_client_write);
1673
1674 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1675 {
1676         int err;
1677         struct p9_client *clnt;
1678         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1679         struct p9_req_t *req;
1680         u16 ignored;
1681
1682         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1683
1684         if (!ret)
1685                 return ERR_PTR(-ENOMEM);
1686
1687         err = 0;
1688         clnt = fid->clnt;
1689
1690         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1691         if (IS_ERR(req)) {
1692                 err = PTR_ERR(req);
1693                 goto error;
1694         }
1695
1696         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1697         if (err) {
1698                 trace_9p_protocol_dump(clnt, req->rc);
1699                 p9_free_req(clnt, req);
1700                 goto error;
1701         }
1702
1703         p9_debug(P9_DEBUG_9P,
1704                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1705                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1706                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1707                 "<<<    uid=%d gid=%d n_muid=%d\n",
1708                 ret->size, ret->type, ret->dev, ret->qid.type,
1709                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1710                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1711                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1712                 from_kuid(&init_user_ns, ret->n_uid),
1713                 from_kgid(&init_user_ns, ret->n_gid),
1714                 from_kuid(&init_user_ns, ret->n_muid));
1715
1716         p9_free_req(clnt, req);
1717         return ret;
1718
1719 error:
1720         kfree(ret);
1721         return ERR_PTR(err);
1722 }
1723 EXPORT_SYMBOL(p9_client_stat);
1724
1725 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1726                                                         u64 request_mask)
1727 {
1728         int err;
1729         struct p9_client *clnt;
1730         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1731                                                                 GFP_KERNEL);
1732         struct p9_req_t *req;
1733
1734         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1735                                                         fid->fid, request_mask);
1736
1737         if (!ret)
1738                 return ERR_PTR(-ENOMEM);
1739
1740         err = 0;
1741         clnt = fid->clnt;
1742
1743         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1744         if (IS_ERR(req)) {
1745                 err = PTR_ERR(req);
1746                 goto error;
1747         }
1748
1749         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1750         if (err) {
1751                 trace_9p_protocol_dump(clnt, req->rc);
1752                 p9_free_req(clnt, req);
1753                 goto error;
1754         }
1755
1756         p9_debug(P9_DEBUG_9P,
1757                 "<<< RGETATTR st_result_mask=%lld\n"
1758                 "<<< qid=%x.%llx.%x\n"
1759                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1760                 "<<< st_uid=%d st_gid=%d\n"
1761                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1762                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1763                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1764                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1765                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1766                 "<<< st_gen=%lld st_data_version=%lld",
1767                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1768                 ret->qid.version, ret->st_mode, ret->st_nlink,
1769                 from_kuid(&init_user_ns, ret->st_uid),
1770                 from_kgid(&init_user_ns, ret->st_gid),
1771                 ret->st_rdev, ret->st_size, ret->st_blksize,
1772                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1773                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1774                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1775                 ret->st_gen, ret->st_data_version);
1776
1777         p9_free_req(clnt, req);
1778         return ret;
1779
1780 error:
1781         kfree(ret);
1782         return ERR_PTR(err);
1783 }
1784 EXPORT_SYMBOL(p9_client_getattr_dotl);
1785
1786 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1787 {
1788         int ret;
1789
1790         /* NOTE: size shouldn't include its own length */
1791         /* size[2] type[2] dev[4] qid[13] */
1792         /* mode[4] atime[4] mtime[4] length[8]*/
1793         /* name[s] uid[s] gid[s] muid[s] */
1794         ret = 2+4+13+4+4+4+8+2+2+2+2;
1795
1796         if (wst->name)
1797                 ret += strlen(wst->name);
1798         if (wst->uid)
1799                 ret += strlen(wst->uid);
1800         if (wst->gid)
1801                 ret += strlen(wst->gid);
1802         if (wst->muid)
1803                 ret += strlen(wst->muid);
1804
1805         if ((proto_version == p9_proto_2000u) ||
1806                 (proto_version == p9_proto_2000L)) {
1807                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1808                 if (wst->extension)
1809                         ret += strlen(wst->extension);
1810         }
1811
1812         return ret;
1813 }
1814
1815 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1816 {
1817         int err;
1818         struct p9_req_t *req;
1819         struct p9_client *clnt;
1820
1821         err = 0;
1822         clnt = fid->clnt;
1823         wst->size = p9_client_statsize(wst, clnt->proto_version);
1824         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1825         p9_debug(P9_DEBUG_9P,
1826                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1827                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1828                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1829                 "     uid=%d gid=%d n_muid=%d\n",
1830                 wst->size, wst->type, wst->dev, wst->qid.type,
1831                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1832                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1833                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1834                 from_kuid(&init_user_ns, wst->n_uid),
1835                 from_kgid(&init_user_ns, wst->n_gid),
1836                 from_kuid(&init_user_ns, wst->n_muid));
1837
1838         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1839         if (IS_ERR(req)) {
1840                 err = PTR_ERR(req);
1841                 goto error;
1842         }
1843
1844         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1845
1846         p9_free_req(clnt, req);
1847 error:
1848         return err;
1849 }
1850 EXPORT_SYMBOL(p9_client_wstat);
1851
1852 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1853 {
1854         int err;
1855         struct p9_req_t *req;
1856         struct p9_client *clnt;
1857
1858         err = 0;
1859         clnt = fid->clnt;
1860         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1861         p9_debug(P9_DEBUG_9P,
1862                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1863                 "    atime_sec=%lld atime_nsec=%lld\n"
1864                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1865                 p9attr->valid, p9attr->mode,
1866                 from_kuid(&init_user_ns, p9attr->uid),
1867                 from_kgid(&init_user_ns, p9attr->gid),
1868                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1869                 p9attr->mtime_sec, p9attr->mtime_nsec);
1870
1871         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1872
1873         if (IS_ERR(req)) {
1874                 err = PTR_ERR(req);
1875                 goto error;
1876         }
1877         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1878         p9_free_req(clnt, req);
1879 error:
1880         return err;
1881 }
1882 EXPORT_SYMBOL(p9_client_setattr);
1883
1884 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1885 {
1886         int err;
1887         struct p9_req_t *req;
1888         struct p9_client *clnt;
1889
1890         err = 0;
1891         clnt = fid->clnt;
1892
1893         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1894
1895         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1896         if (IS_ERR(req)) {
1897                 err = PTR_ERR(req);
1898                 goto error;
1899         }
1900
1901         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1902                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1903                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1904         if (err) {
1905                 trace_9p_protocol_dump(clnt, req->rc);
1906                 p9_free_req(clnt, req);
1907                 goto error;
1908         }
1909
1910         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1911                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1912                 "fsid %llu namelen %ld\n",
1913                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1914                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1915                 sb->fsid, (long int)sb->namelen);
1916
1917         p9_free_req(clnt, req);
1918 error:
1919         return err;
1920 }
1921 EXPORT_SYMBOL(p9_client_statfs);
1922
1923 int p9_client_rename(struct p9_fid *fid,
1924                      struct p9_fid *newdirfid, const char *name)
1925 {
1926         int err;
1927         struct p9_req_t *req;
1928         struct p9_client *clnt;
1929
1930         err = 0;
1931         clnt = fid->clnt;
1932
1933         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1934                         fid->fid, newdirfid->fid, name);
1935
1936         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1937                         newdirfid->fid, name);
1938         if (IS_ERR(req)) {
1939                 err = PTR_ERR(req);
1940                 goto error;
1941         }
1942
1943         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1944
1945         p9_free_req(clnt, req);
1946 error:
1947         return err;
1948 }
1949 EXPORT_SYMBOL(p9_client_rename);
1950
1951 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1952                        struct p9_fid *newdirfid, const char *new_name)
1953 {
1954         int err;
1955         struct p9_req_t *req;
1956         struct p9_client *clnt;
1957
1958         err = 0;
1959         clnt = olddirfid->clnt;
1960
1961         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1962                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1963                    newdirfid->fid, new_name);
1964
1965         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1966                             old_name, newdirfid->fid, new_name);
1967         if (IS_ERR(req)) {
1968                 err = PTR_ERR(req);
1969                 goto error;
1970         }
1971
1972         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1973                    newdirfid->fid, new_name);
1974
1975         p9_free_req(clnt, req);
1976 error:
1977         return err;
1978 }
1979 EXPORT_SYMBOL(p9_client_renameat);
1980
1981 /*
1982  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1983  */
1984 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1985                                 const char *attr_name, u64 *attr_size)
1986 {
1987         int err;
1988         struct p9_req_t *req;
1989         struct p9_client *clnt;
1990         struct p9_fid *attr_fid;
1991
1992         err = 0;
1993         clnt = file_fid->clnt;
1994         attr_fid = p9_fid_create(clnt);
1995         if (IS_ERR(attr_fid)) {
1996                 err = PTR_ERR(attr_fid);
1997                 attr_fid = NULL;
1998                 goto error;
1999         }
2000         p9_debug(P9_DEBUG_9P,
2001                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2002                 file_fid->fid, attr_fid->fid, attr_name);
2003
2004         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2005                         file_fid->fid, attr_fid->fid, attr_name);
2006         if (IS_ERR(req)) {
2007                 err = PTR_ERR(req);
2008                 goto error;
2009         }
2010         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2011         if (err) {
2012                 trace_9p_protocol_dump(clnt, req->rc);
2013                 p9_free_req(clnt, req);
2014                 goto clunk_fid;
2015         }
2016         p9_free_req(clnt, req);
2017         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2018                 attr_fid->fid, *attr_size);
2019         return attr_fid;
2020 clunk_fid:
2021         p9_client_clunk(attr_fid);
2022         attr_fid = NULL;
2023 error:
2024         if (attr_fid && (attr_fid != file_fid))
2025                 p9_fid_destroy(attr_fid);
2026
2027         return ERR_PTR(err);
2028 }
2029 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2030
2031 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2032                         u64 attr_size, int flags)
2033 {
2034         int err;
2035         struct p9_req_t *req;
2036         struct p9_client *clnt;
2037
2038         p9_debug(P9_DEBUG_9P,
2039                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2040                 fid->fid, name, (long long)attr_size, flags);
2041         err = 0;
2042         clnt = fid->clnt;
2043         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2044                         fid->fid, name, attr_size, flags);
2045         if (IS_ERR(req)) {
2046                 err = PTR_ERR(req);
2047                 goto error;
2048         }
2049         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2050         p9_free_req(clnt, req);
2051 error:
2052         return err;
2053 }
2054 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2055
2056 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2057 {
2058         int err, rsize, non_zc = 0;
2059         struct p9_client *clnt;
2060         struct p9_req_t *req;
2061         char *dataptr;
2062         struct kvec kv = {.iov_base = data, .iov_len = count};
2063         struct iov_iter to;
2064
2065         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2066
2067         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2068                                 fid->fid, (unsigned long long) offset, count);
2069
2070         err = 0;
2071         clnt = fid->clnt;
2072
2073         rsize = fid->iounit;
2074         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2075                 rsize = clnt->msize - P9_READDIRHDRSZ;
2076
2077         if (count < rsize)
2078                 rsize = count;
2079
2080         /* Don't bother zerocopy for small IO (< 1024) */
2081         if (clnt->trans_mod->zc_request && rsize > 1024) {
2082                 /*
2083                  * response header len is 11
2084                  * PDU Header(7) + IO Size (4)
2085                  */
2086                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2087                                        11, "dqd", fid->fid, offset, rsize);
2088         } else {
2089                 non_zc = 1;
2090                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2091                                     offset, rsize);
2092         }
2093         if (IS_ERR(req)) {
2094                 err = PTR_ERR(req);
2095                 goto error;
2096         }
2097
2098         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2099         if (err) {
2100                 trace_9p_protocol_dump(clnt, req->rc);
2101                 goto free_and_error;
2102         }
2103         if (rsize < count) {
2104                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2105                 count = rsize;
2106         }
2107
2108         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2109
2110         if (non_zc)
2111                 memmove(data, dataptr, count);
2112
2113         p9_free_req(clnt, req);
2114         return count;
2115
2116 free_and_error:
2117         p9_free_req(clnt, req);
2118 error:
2119         return err;
2120 }
2121 EXPORT_SYMBOL(p9_client_readdir);
2122
2123 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2124                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2125 {
2126         int err;
2127         struct p9_client *clnt;
2128         struct p9_req_t *req;
2129
2130         err = 0;
2131         clnt = fid->clnt;
2132         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2133                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2134         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2135                 MAJOR(rdev), MINOR(rdev), gid);
2136         if (IS_ERR(req))
2137                 return PTR_ERR(req);
2138
2139         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2140         if (err) {
2141                 trace_9p_protocol_dump(clnt, req->rc);
2142                 goto error;
2143         }
2144         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2145                                 (unsigned long long)qid->path, qid->version);
2146
2147 error:
2148         p9_free_req(clnt, req);
2149         return err;
2150
2151 }
2152 EXPORT_SYMBOL(p9_client_mknod_dotl);
2153
2154 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2155                                 kgid_t gid, struct p9_qid *qid)
2156 {
2157         int err;
2158         struct p9_client *clnt;
2159         struct p9_req_t *req;
2160
2161         err = 0;
2162         clnt = fid->clnt;
2163         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2164                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2165         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2166                 gid);
2167         if (IS_ERR(req))
2168                 return PTR_ERR(req);
2169
2170         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2171         if (err) {
2172                 trace_9p_protocol_dump(clnt, req->rc);
2173                 goto error;
2174         }
2175         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2176                                 (unsigned long long)qid->path, qid->version);
2177
2178 error:
2179         p9_free_req(clnt, req);
2180         return err;
2181
2182 }
2183 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2184
2185 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2186 {
2187         int err;
2188         struct p9_client *clnt;
2189         struct p9_req_t *req;
2190
2191         err = 0;
2192         clnt = fid->clnt;
2193         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2194                         "start %lld length %lld proc_id %d client_id %s\n",
2195                         fid->fid, flock->type, flock->flags, flock->start,
2196                         flock->length, flock->proc_id, flock->client_id);
2197
2198         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2199                                 flock->flags, flock->start, flock->length,
2200                                         flock->proc_id, flock->client_id);
2201
2202         if (IS_ERR(req))
2203                 return PTR_ERR(req);
2204
2205         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2206         if (err) {
2207                 trace_9p_protocol_dump(clnt, req->rc);
2208                 goto error;
2209         }
2210         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2211 error:
2212         p9_free_req(clnt, req);
2213         return err;
2214
2215 }
2216 EXPORT_SYMBOL(p9_client_lock_dotl);
2217
2218 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2219 {
2220         int err;
2221         struct p9_client *clnt;
2222         struct p9_req_t *req;
2223
2224         err = 0;
2225         clnt = fid->clnt;
2226         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2227                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2228                 glock->start, glock->length, glock->proc_id, glock->client_id);
2229
2230         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2231                 glock->start, glock->length, glock->proc_id, glock->client_id);
2232
2233         if (IS_ERR(req))
2234                 return PTR_ERR(req);
2235
2236         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2237                         &glock->start, &glock->length, &glock->proc_id,
2238                         &glock->client_id);
2239         if (err) {
2240                 trace_9p_protocol_dump(clnt, req->rc);
2241                 goto error;
2242         }
2243         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2244                 "proc_id %d client_id %s\n", glock->type, glock->start,
2245                 glock->length, glock->proc_id, glock->client_id);
2246 error:
2247         p9_free_req(clnt, req);
2248         return err;
2249 }
2250 EXPORT_SYMBOL(p9_client_getlock_dotl);
2251
2252 int p9_client_readlink(struct p9_fid *fid, char **target)
2253 {
2254         int err;
2255         struct p9_client *clnt;
2256         struct p9_req_t *req;
2257
2258         err = 0;
2259         clnt = fid->clnt;
2260         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2261
2262         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2263         if (IS_ERR(req))
2264                 return PTR_ERR(req);
2265
2266         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2267         if (err) {
2268                 trace_9p_protocol_dump(clnt, req->rc);
2269                 goto error;
2270         }
2271         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2272 error:
2273         p9_free_req(clnt, req);
2274         return err;
2275 }
2276 EXPORT_SYMBOL(p9_client_readlink);