kernel/net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/poll.h>
  32 #include <linux/idr.h>
  33 #include <linux/mutex.h>
  34 #include <linux/slab.h>
  35 #include <linux/sched.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/uio.h>
  38 #include <net/9p/9p.h>
  39 #include <linux/parser.h>
  40 #include <net/9p/client.h>
  41 #include <net/9p/transport.h>
  42 #include "protocol.h"
  43
  44 #define CREATE_TRACE_POINTS
  45 #include <trace/events/9p.h>
  46
  47 /*
  48   * Client Option Parsing (code inspired by NFS code)
  49   *  - a little lazy - parse all client options
  50   */
  51
  52 enum {
  53         Opt_msize,
  54         Opt_trans,
  55         Opt_legacy,
  56         Opt_version,
  57         Opt_err,
  58 };
  59
  60 static const match_table_t tokens = {
  61         {Opt_msize, "msize=%u"},
  62         {Opt_legacy, "noextend"},
  63         {Opt_trans, "trans=%s"},
  64         {Opt_version, "version=%s"},
  65         {Opt_err, NULL},
  66 };
  67
  68 inline int p9_is_proto_dotl(struct p9_client *clnt)
  69 {
  70         return clnt->proto_version == p9_proto_2000L;
  71 }
  72 EXPORT_SYMBOL(p9_is_proto_dotl);
  73
  74 inline int p9_is_proto_dotu(struct p9_client *clnt)
  75 {
  76         return clnt->proto_version == p9_proto_2000u;
  77 }
  78 EXPORT_SYMBOL(p9_is_proto_dotu);
  79
  80 /*
  81  * Some error codes are taken directly from the server replies,
  82  * make sure they are valid.
  83  */
  84 static int safe_errno(int err)
  85 {
  86         if ((err > 0) || (err < -MAX_ERRNO)) {
  87                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
  88                 return -EPROTO;
  89         }
  90         return err;
  91 }
  92
  93
  94 /* Interpret mount option for protocol version */
  95 static int get_protocol_version(char *s)
  96 {
  97         int version = -EINVAL;
  98
  99         if (!strcmp(s, "9p2000")) {
 100                 version = p9_proto_legacy;
 101                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
 102         } else if (!strcmp(s, "9p2000.u")) {
 103                 version = p9_proto_2000u;
 104                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
 105         } else if (!strcmp(s, "9p2000.L")) {
 106                 version = p9_proto_2000L;
 107                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
 108         } else
 109                 pr_info("Unknown protocol version %s\n", s);
 110
 111         return version;
 112 }
 113
 114 /**
 115  * parse_options - parse mount options into client structure
 116  * @opts: options string passed from mount
 117  * @clnt: existing v9fs client information
 118  *
 119  * Return 0 upon success, -ERRNO upon failure
 120  */
 121
 122 static int parse_opts(char *opts, struct p9_client *clnt)
 123 {
 124         char *options, *tmp_options;
 125         char *p;
 126         substring_t args[MAX_OPT_ARGS];
 127         int option;
 128         char *s;
 129         int ret = 0;
 130
 131         clnt->proto_version = p9_proto_2000L;
 132         clnt->msize = 8192;
 133
 134         if (!opts)
 135                 return 0;
 136
 137         tmp_options = kstrdup(opts, GFP_KERNEL);
 138         if (!tmp_options) {
 139                 p9_debug(P9_DEBUG_ERROR,
 140                          "failed to allocate copy of option string\n");
 141                 return -ENOMEM;
 142         }
 143         options = tmp_options;
 144
 145         while ((p = strsep(&options, ",")) != NULL) {
 146                 int token, r;
 147                 if (!*p)
 148                         continue;
 149                 token = match_token(p, tokens, args);
 150                 switch (token) {
 151                 case Opt_msize:
 152                         r = match_int(&args[0], &option);
 153                         if (r < 0) {
 154                                 p9_debug(P9_DEBUG_ERROR,
 155                                          "integer field, but no integer?\n");
 156                                 ret = r;
 157                                 continue;
 158                         }
 159                         clnt->msize = option;
 160                         break;
 161                 case Opt_trans:
 162                         s = match_strdup(&args[0]);
 163                         if (!s) {
 164                                 ret = -ENOMEM;
 165                                 p9_debug(P9_DEBUG_ERROR,
 166                                          "problem allocating copy of trans arg\n");
 167                                 goto free_and_return;
 168                          }
 169                         clnt->trans_mod = v9fs_get_trans_by_name(s);
 170                         if (clnt->trans_mod == NULL) {
 171                                 pr_info("Could not find request transport: %s\n",
 172                                         s);
 173                                 ret = -EINVAL;
 174                                 kfree(s);
 175                                 goto free_and_return;
 176                         }
 177                         kfree(s);
 178                         break;
 179                 case Opt_legacy:
 180                         clnt->proto_version = p9_proto_legacy;
 181                         break;
 182                 case Opt_version:
 183                         s = match_strdup(&args[0]);
 184                         if (!s) {
 185                                 ret = -ENOMEM;
 186                                 p9_debug(P9_DEBUG_ERROR,
 187                                          "problem allocating copy of version arg\n");
 188                                 goto free_and_return;
 189                         }
 190                         ret = get_protocol_version(s);
 191                         if (ret == -EINVAL) {
 192                                 kfree(s);
 193                                 goto free_and_return;
 194                         }
 195                         kfree(s);
 196                         clnt->proto_version = ret;
 197                         break;
 198                 default:
 199                         continue;
 200                 }
 201         }
 202
 203 free_and_return:
 204         kfree(tmp_options);
 205         return ret;
 206 }
 207
 208 static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
 209 {
 210         struct p9_fcall *fc;
 211         fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
 212         if (!fc)
 213                 return NULL;
 214         fc->capacity = alloc_msize;
 215         fc->sdata = (char *) fc + sizeof(struct p9_fcall);
 216         return fc;
 217 }
 218
 219 /**
 220  * p9_tag_alloc - lookup/allocate a request by tag
 221  * @c: client session to lookup tag within
 222  * @tag: numeric id for transaction
 223  *
 224  * this is a simple array lookup, but will grow the
 225  * request_slots as necessary to accommodate transaction
 226  * ids which did not previously have a slot.
 227  *
 228  * this code relies on the client spinlock to manage locks, its
 229  * possible we should switch to something else, but I'd rather
 230  * stick with something low-overhead for the common case.
 231  *
 232  */
 233
 234 static struct p9_req_t *
 235 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
 236 {
 237         unsigned long flags;
 238         int row, col;
 239         struct p9_req_t *req;
 240         int alloc_msize = min(c->msize, max_size);
 241
 242         /* This looks up the original request by tag so we know which
 243          * buffer to read the data into */
 244         tag++;
 245
 246         if (tag >= c->max_tag) {
 247                 spin_lock_irqsave(&c->lock, flags);
 248                 /* check again since original check was outside of lock */
 249                 while (tag >= c->max_tag) {
 250                         row = (tag / P9_ROW_MAXTAG);
 251                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 252                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 253
 254                         if (!c->reqs[row]) {
 255                                 pr_err("Couldn't grow tag array\n");
 256                                 spin_unlock_irqrestore(&c->lock, flags);
 257                                 return ERR_PTR(-ENOMEM);
 258                         }
 259                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 260                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 261                                 c->reqs[row][col].tc = NULL;
 262                         }
 263                         c->max_tag += P9_ROW_MAXTAG;
 264                 }
 265                 spin_unlock_irqrestore(&c->lock, flags);
 266         }
 267         row = tag / P9_ROW_MAXTAG;
 268         col = tag % P9_ROW_MAXTAG;
 269
 270         req = &c->reqs[row][col];
 271         if (!req->wq) {
 272                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
 273                 if (!req->wq)
 274                         goto grow_failed;
 275                 init_waitqueue_head(req->wq);
 276         }
 277
 278         if (!req->tc)
 279                 req->tc = p9_fcall_alloc(alloc_msize);
 280         if (!req->rc)
 281                 req->rc = p9_fcall_alloc(alloc_msize);
 282         if (!req->tc || !req->rc)
 283                 goto grow_failed;
 284
 285         p9pdu_reset(req->tc);
 286         p9pdu_reset(req->rc);
 287
 288         req->tc->tag = tag-1;
 289         req->status = REQ_STATUS_ALLOC;
 290
 291         return req;
 292
 293 grow_failed:
 294         pr_err("Couldn't grow tag array\n");
 295         kfree(req->tc);
 296         kfree(req->rc);
 297         kfree(req->wq);
 298         req->tc = req->rc = NULL;
 299         req->wq = NULL;
 300         return ERR_PTR(-ENOMEM);
 301 }
 302
 303 /**
 304  * p9_tag_lookup - lookup a request by tag
 305  * @c: client session to lookup tag within
 306  * @tag: numeric id for transaction
 307  *
 308  */
 309
 310 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 311 {
 312         int row, col;
 313
 314         /* This looks up the original request by tag so we know which
 315          * buffer to read the data into */
 316         tag++;
 317
 318         if(tag >= c->max_tag)
 319                 return NULL;
 320
 321         row = tag / P9_ROW_MAXTAG;
 322         col = tag % P9_ROW_MAXTAG;
 323
 324         return &c->reqs[row][col];
 325 }
 326 EXPORT_SYMBOL(p9_tag_lookup);
 327
 328 /**
 329  * p9_tag_init - setup tags structure and contents
 330  * @c:  v9fs client struct
 331  *
 332  * This initializes the tags structure for each client instance.
 333  *
 334  */
 335
 336 static int p9_tag_init(struct p9_client *c)
 337 {
 338         int err = 0;
 339
 340         c->tagpool = p9_idpool_create();
 341         if (IS_ERR(c->tagpool)) {
 342                 err = PTR_ERR(c->tagpool);
 343                 goto error;
 344         }
 345         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
 346         if (err < 0) {
 347                 p9_idpool_destroy(c->tagpool);
 348                 goto error;
 349         }
 350         c->max_tag = 0;
 351 error:
 352         return err;
 353 }
 354
 355 /**
 356  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 357  * @c:  v9fs client struct
 358  *
 359  * This frees resources associated with the tags structure
 360  *
 361  */
 362 static void p9_tag_cleanup(struct p9_client *c)
 363 {
 364         int row, col;
 365
 366         /* check to insure all requests are idle */
 367         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 368                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 369                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 370                                 p9_debug(P9_DEBUG_MUX,
 371                                          "Attempting to cleanup non-free tag %d,%d\n",
 372                                          row, col);
 373                                 /* TODO: delay execution of cleanup */
 374                                 return;
 375                         }
 376                 }
 377         }
 378
 379         if (c->tagpool) {
 380                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
 381                 p9_idpool_destroy(c->tagpool);
 382         }
 383
 384         /* free requests associated with tags */
 385         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 386                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 387                         kfree(c->reqs[row][col].wq);
 388                         kfree(c->reqs[row][col].tc);
 389                         kfree(c->reqs[row][col].rc);
 390                 }
 391                 kfree(c->reqs[row]);
 392         }
 393         c->max_tag = 0;
 394 }
 395
 396 /**
 397  * p9_free_req - free a request and clean-up as necessary
 398  * c: client state
 399  * r: request to release
 400  *
 401  */
 402
 403 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 404 {
 405         int tag = r->tc->tag;
 406         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 407
 408         r->status = REQ_STATUS_IDLE;
 409         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 410                 p9_idpool_put(tag, c->tagpool);
 411 }
 412
 413 /**
 414  * p9_client_cb - call back from transport to client
 415  * c: client state
 416  * req: request received
 417  *
 418  */
 419 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 420 {
 421         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 422
 423         /*
 424          * This barrier is needed to make sure any change made to req before
 425          * the other thread wakes up will indeed be seen by the waiting side.
 426          */
 427         smp_wmb();
 428         req->status = status;
 429
 430         wake_up(req->wq);
 431         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 432 }
 433 EXPORT_SYMBOL(p9_client_cb);
 434
 435 /**
 436  * p9_parse_header - parse header arguments out of a packet
 437  * @pdu: packet to parse
 438  * @size: size of packet
 439  * @type: type of request
 440  * @tag: tag of packet
 441  * @rewind: set if we need to rewind offset afterwards
 442  */
 443
 444 int
 445 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 446                                                                 int rewind)
 447 {
 448         int8_t r_type;
 449         int16_t r_tag;
 450         int32_t r_size;
 451         int offset = pdu->offset;
 452         int err;
 453
 454         pdu->offset = 0;
 455         if (pdu->size == 0)
 456                 pdu->size = 7;
 457
 458         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 459         if (err)
 460                 goto rewind_and_exit;
 461
 462         pdu->size = r_size;
 463         pdu->id = r_type;
 464         pdu->tag = r_tag;
 465
 466         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 467                  pdu->size, pdu->id, pdu->tag);
 468
 469         if (type)
 470                 *type = r_type;
 471         if (tag)
 472                 *tag = r_tag;
 473         if (size)
 474                 *size = r_size;
 475
 476
 477 rewind_and_exit:
 478         if (rewind)
 479                 pdu->offset = offset;
 480         return err;
 481 }
 482 EXPORT_SYMBOL(p9_parse_header);
 483
 484 /**
 485  * p9_check_errors - check 9p packet for error return and process it
 486  * @c: current client instance
 487  * @req: request to parse and check for error conditions
 488  *
 489  * returns error code if one is discovered, otherwise returns 0
 490  *
 491  * this will have to be more complicated if we have multiple
 492  * error packet types
 493  */
 494
 495 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 496 {
 497         int8_t type;
 498         int err;
 499         int ecode;
 500
 501         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 502         /*
 503          * dump the response from server
 504          * This should be after check errors which poplulate pdu_fcall.
 505          */
 506         trace_9p_protocol_dump(c, req->rc);
 507         if (err) {
 508                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 509                 return err;
 510         }
 511         if (type != P9_RERROR && type != P9_RLERROR)
 512                 return 0;
 513
 514         if (!p9_is_proto_dotl(c)) {
 515                 char *ename;
 516                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 517                                   &ename, &ecode);
 518                 if (err)
 519                         goto out_err;
 520
 521                 if (p9_is_proto_dotu(c))
 522                         err = -ecode;
 523
 524                 if (!err || !IS_ERR_VALUE(err)) {
 525                         err = p9_errstr2errno(ename, strlen(ename));
 526
 527                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 528                                  -ecode, ename);
 529                 }
 530                 kfree(ename);
 531         } else {
 532                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 533                 err = -ecode;
 534
 535                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 536         }
 537
 538         return err;
 539
 540 out_err:
 541         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 542
 543         return err;
 544 }
 545
 546 /**
 547  * p9_check_zc_errors - check 9p packet for error return and process it
 548  * @c: current client instance
 549  * @req: request to parse and check for error conditions
 550  * @in_hdrlen: Size of response protocol buffer.
 551  *
 552  * returns error code if one is discovered, otherwise returns 0
 553  *
 554  * this will have to be more complicated if we have multiple
 555  * error packet types
 556  */
 557
 558 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 559                               struct iov_iter *uidata, int in_hdrlen)
 560 {
 561         int err;
 562         int ecode;
 563         int8_t type;
 564         char *ename = NULL;
 565
 566         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 567         /*
 568          * dump the response from server
 569          * This should be after parse_header which poplulate pdu_fcall.
 570          */
 571         trace_9p_protocol_dump(c, req->rc);
 572         if (err) {
 573                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 574                 return err;
 575         }
 576
 577         if (type != P9_RERROR && type != P9_RLERROR)
 578                 return 0;
 579
 580         if (!p9_is_proto_dotl(c)) {
 581                 /* Error is reported in string format */
 582                 int len;
 583                 /* 7 = header size for RERROR; */
 584                 int inline_len = in_hdrlen - 7;
 585
 586                 len =  req->rc->size - req->rc->offset;
 587                 if (len > (P9_ZC_HDR_SZ - 7)) {
 588                         err = -EFAULT;
 589                         goto out_err;
 590                 }
 591
 592                 ename = &req->rc->sdata[req->rc->offset];
 593                 if (len > inline_len) {
 594                         /* We have error in external buffer */
 595                         err = copy_from_iter(ename + inline_len,
 596                                              len - inline_len, uidata);
 597                         if (err != len - inline_len) {
 598                                 err = -EFAULT;
 599                                 goto out_err;
 600                         }
 601                 }
 602                 ename = NULL;
 603                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 604                                   &ename, &ecode);
 605                 if (err)
 606                         goto out_err;
 607
 608                 if (p9_is_proto_dotu(c))
 609                         err = -ecode;
 610
 611                 if (!err || !IS_ERR_VALUE(err)) {
 612                         err = p9_errstr2errno(ename, strlen(ename));
 613
 614                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 615                                  -ecode, ename);
 616                 }
 617                 kfree(ename);
 618         } else {
 619                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 620                 err = -ecode;
 621
 622                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 623         }
 624         return err;
 625
 626 out_err:
 627         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 628         return err;
 629 }
 630
 631 static struct p9_req_t *
 632 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 633
 634 /**
 635  * p9_client_flush - flush (cancel) a request
 636  * @c: client state
 637  * @oldreq: request to cancel
 638  *
 639  * This sents a flush for a particular request and links
 640  * the flush request to the original request.  The current
 641  * code only supports a single flush request although the protocol
 642  * allows for multiple flush requests to be sent for a single request.
 643  *
 644  */
 645
 646 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 647 {
 648         struct p9_req_t *req;
 649         int16_t oldtag;
 650         int err;
 651
 652         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 653         if (err)
 654                 return err;
 655
 656         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 657
 658         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 659         if (IS_ERR(req))
 660                 return PTR_ERR(req);
 661
 662         /*
 663          * if we haven't received a response for oldreq,
 664          * remove it from the list
 665          */
 666         if (oldreq->status == REQ_STATUS_SENT)
 667                 if (c->trans_mod->cancelled)
 668                         c->trans_mod->cancelled(c, oldreq);
 669
 670         p9_free_req(c, req);
 671         return 0;
 672 }
 673
 674 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 675                                               int8_t type, int req_size,
 676                                               const char *fmt, va_list ap)
 677 {
 678         int tag, err;
 679         struct p9_req_t *req;
 680
 681         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 682
 683         /* we allow for any status other than disconnected */
 684         if (c->status == Disconnected)
 685                 return ERR_PTR(-EIO);
 686
 687         /* if status is begin_disconnected we allow only clunk request */
 688         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 689                 return ERR_PTR(-EIO);
 690
 691         tag = P9_NOTAG;
 692         if (type != P9_TVERSION) {
 693                 tag = p9_idpool_get(c->tagpool);
 694                 if (tag < 0)
 695                         return ERR_PTR(-ENOMEM);
 696         }
 697
 698         req = p9_tag_alloc(c, tag, req_size);
 699         if (IS_ERR(req))
 700                 return req;
 701
 702         /* marshall the data */
 703         p9pdu_prepare(req->tc, tag, type);
 704         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 705         if (err)
 706                 goto reterr;
 707         p9pdu_finalize(c, req->tc);
 708         trace_9p_client_req(c, type, tag);
 709         return req;
 710 reterr:
 711         p9_free_req(c, req);
 712         return ERR_PTR(err);
 713 }
 714
 715 /**
 716  * p9_client_rpc - issue a request and wait for a response
 717  * @c: client session
 718  * @type: type of request
 719  * @fmt: protocol format string (see protocol.c)
 720  *
 721  * Returns request structure (which client must free using p9_free_req)
 722  */
 723
 724 static struct p9_req_t *
 725 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 726 {
 727         va_list ap;
 728         int sigpending, err;
 729         unsigned long flags;
 730         struct p9_req_t *req;
 731
 732         va_start(ap, fmt);
 733         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 734         va_end(ap);
 735         if (IS_ERR(req))
 736                 return req;
 737
 738         if (signal_pending(current)) {
 739                 sigpending = 1;
 740                 clear_thread_flag(TIF_SIGPENDING);
 741         } else
 742                 sigpending = 0;
 743
 744         err = c->trans_mod->request(c, req);
 745         if (err < 0) {
 746                 if (err != -ERESTARTSYS && err != -EFAULT)
 747                         c->status = Disconnected;
 748                 goto reterr;
 749         }
 750 again:
 751         /* Wait for the response */
 752         err = wait_event_interruptible(*req->wq,
 753                                        req->status >= REQ_STATUS_RCVD);
 754
 755         /*
 756          * Make sure our req is coherent with regard to updates in other
 757          * threads - echoes to wmb() in the callback
 758          */
 759         smp_rmb();
 760
 761         if ((err == -ERESTARTSYS) && (c->status == Connected)
 762                                   && (type == P9_TFLUSH)) {
 763                 sigpending = 1;
 764                 clear_thread_flag(TIF_SIGPENDING);
 765                 goto again;
 766         }
 767
 768         if (req->status == REQ_STATUS_ERROR) {
 769                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 770                 err = req->t_err;
 771         }
 772         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 773                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 774                 sigpending = 1;
 775                 clear_thread_flag(TIF_SIGPENDING);
 776
 777                 if (c->trans_mod->cancel(c, req))
 778                         p9_client_flush(c, req);
 779
 780                 /* if we received the response anyway, don't signal error */
 781                 if (req->status == REQ_STATUS_RCVD)
 782                         err = 0;
 783         }
 784         if (sigpending) {
 785                 spin_lock_irqsave(&current->sighand->siglock, flags);
 786                 recalc_sigpending();
 787                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 788         }
 789         if (err < 0)
 790                 goto reterr;
 791
 792         err = p9_check_errors(c, req);
 793         trace_9p_client_res(c, type, req->rc->tag, err);
 794         if (!err)
 795                 return req;
 796 reterr:
 797         p9_free_req(c, req);
 798         return ERR_PTR(safe_errno(err));
 799 }
 800
 801 /**
 802  * p9_client_zc_rpc - issue a request and wait for a response
 803  * @c: client session
 804  * @type: type of request
 805  * @uidata: destination for zero copy read
 806  * @uodata: source for zero copy write
 807  * @inlen: read buffer size
 808  * @olen: write buffer size
 809  * @hdrlen: reader header size, This is the size of response protocol data
 810  * @fmt: protocol format string (see protocol.c)
 811  *
 812  * Returns request structure (which client must free using p9_free_req)
 813  */
 814 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 815                                          struct iov_iter *uidata,
 816                                          struct iov_iter *uodata,
 817                                          int inlen, int olen, int in_hdrlen,
 818                                          const char *fmt, ...)
 819 {
 820         va_list ap;
 821         int sigpending, err;
 822         unsigned long flags;
 823         struct p9_req_t *req;
 824
 825         va_start(ap, fmt);
 826         /*
 827          * We allocate a inline protocol data of only 4k bytes.
 828          * The actual content is passed in zero-copy fashion.
 829          */
 830         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 831         va_end(ap);
 832         if (IS_ERR(req))
 833                 return req;
 834
 835         if (signal_pending(current)) {
 836                 sigpending = 1;
 837                 clear_thread_flag(TIF_SIGPENDING);
 838         } else
 839                 sigpending = 0;
 840
 841         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 842                                        inlen, olen, in_hdrlen);
 843         if (err < 0) {
 844                 if (err == -EIO)
 845                         c->status = Disconnected;
 846                 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         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                 char **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, 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, 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, char *name, char *symtgt, kgid_t gid,
1364                 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, 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
1544         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1545                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1546
1547         while (iov_iter_count(to)) {
1548                 int count = iov_iter_count(to);
1549                 int rsize, non_zc = 0;
1550                 char *dataptr;
1551
1552                 rsize = fid->iounit;
1553                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1554                         rsize = clnt->msize - P9_IOHDRSZ;
1555
1556                 if (count < rsize)
1557                         rsize = count;
1558
1559                 /* Don't bother zerocopy for small IO (< 1024) */
1560                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1561                         /*
1562                          * response header len is 11
1563                          * PDU Header(7) + IO Size (4)
1564                          */
1565                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1566                                                0, 11, "dqd", fid->fid,
1567                                                offset, rsize);
1568                 } else {
1569                         non_zc = 1;
1570                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1571                                             rsize);
1572                 }
1573                 if (IS_ERR(req)) {
1574                         *err = PTR_ERR(req);
1575                         break;
1576                 }
1577
1578                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1579                                    "D", &count, &dataptr);
1580                 if (*err) {
1581                         trace_9p_protocol_dump(clnt, req->rc);
1582                         p9_free_req(clnt, req);
1583                         break;
1584                 }
1585
1586                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1587                 if (!count) {
1588                         p9_free_req(clnt, req);
1589                         break;
1590                 }
1591
1592                 if (non_zc) {
1593                         int n = copy_to_iter(dataptr, count, to);
1594                         total += n;
1595                         offset += n;
1596                         if (n != count) {
1597                                 *err = -EFAULT;
1598                                 p9_free_req(clnt, req);
1599                                 break;
1600                         }
1601                 } else {
1602                         iov_iter_advance(to, count);
1603                         total += count;
1604                         offset += count;
1605                 }
1606                 p9_free_req(clnt, req);
1607         }
1608         return total;
1609 }
1610 EXPORT_SYMBOL(p9_client_read);
1611
1612 int
1613 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1614 {
1615         struct p9_client *clnt = fid->clnt;
1616         struct p9_req_t *req;
1617         int total = 0;
1618
1619         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1620                                 fid->fid, (unsigned long long) offset,
1621                                 iov_iter_count(from));
1622
1623         while (iov_iter_count(from)) {
1624                 int count = iov_iter_count(from);
1625                 int rsize = fid->iounit;
1626                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1627                         rsize = clnt->msize - P9_IOHDRSZ;
1628
1629                 if (count < rsize)
1630                         rsize = count;
1631
1632                 /* Don't bother zerocopy for small IO (< 1024) */
1633                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1634                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1635                                                rsize, P9_ZC_HDR_SZ, "dqd",
1636                                                fid->fid, offset, rsize);
1637                 } else {
1638                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1639                                                     offset, rsize, from);
1640                 }
1641                 if (IS_ERR(req)) {
1642                         *err = PTR_ERR(req);
1643                         break;
1644                 }
1645
1646                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1647                 if (*err) {
1648                         trace_9p_protocol_dump(clnt, req->rc);
1649                         p9_free_req(clnt, req);
1650                 }
1651
1652                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1653
1654                 p9_free_req(clnt, req);
1655                 iov_iter_advance(from, count);
1656                 total += count;
1657                 offset += count;
1658         }
1659         return total;
1660 }
1661 EXPORT_SYMBOL(p9_client_write);
1662
1663 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1664 {
1665         int err;
1666         struct p9_client *clnt;
1667         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1668         struct p9_req_t *req;
1669         u16 ignored;
1670
1671         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1672
1673         if (!ret)
1674                 return ERR_PTR(-ENOMEM);
1675
1676         err = 0;
1677         clnt = fid->clnt;
1678
1679         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1680         if (IS_ERR(req)) {
1681                 err = PTR_ERR(req);
1682                 goto error;
1683         }
1684
1685         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1686         if (err) {
1687                 trace_9p_protocol_dump(clnt, req->rc);
1688                 p9_free_req(clnt, req);
1689                 goto error;
1690         }
1691
1692         p9_debug(P9_DEBUG_9P,
1693                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1694                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1695                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1696                 "<<<    uid=%d gid=%d n_muid=%d\n",
1697                 ret->size, ret->type, ret->dev, ret->qid.type,
1698                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1699                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1700                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1701                 from_kuid(&init_user_ns, ret->n_uid),
1702                 from_kgid(&init_user_ns, ret->n_gid),
1703                 from_kuid(&init_user_ns, ret->n_muid));
1704
1705         p9_free_req(clnt, req);
1706         return ret;
1707
1708 error:
1709         kfree(ret);
1710         return ERR_PTR(err);
1711 }
1712 EXPORT_SYMBOL(p9_client_stat);
1713
1714 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1715                                                         u64 request_mask)
1716 {
1717         int err;
1718         struct p9_client *clnt;
1719         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1720                                                                 GFP_KERNEL);
1721         struct p9_req_t *req;
1722
1723         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1724                                                         fid->fid, request_mask);
1725
1726         if (!ret)
1727                 return ERR_PTR(-ENOMEM);
1728
1729         err = 0;
1730         clnt = fid->clnt;
1731
1732         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1733         if (IS_ERR(req)) {
1734                 err = PTR_ERR(req);
1735                 goto error;
1736         }
1737
1738         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1739         if (err) {
1740                 trace_9p_protocol_dump(clnt, req->rc);
1741                 p9_free_req(clnt, req);
1742                 goto error;
1743         }
1744
1745         p9_debug(P9_DEBUG_9P,
1746                 "<<< RGETATTR st_result_mask=%lld\n"
1747                 "<<< qid=%x.%llx.%x\n"
1748                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1749                 "<<< st_uid=%d st_gid=%d\n"
1750                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1751                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1752                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1753                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1754                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1755                 "<<< st_gen=%lld st_data_version=%lld",
1756                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1757                 ret->qid.version, ret->st_mode, ret->st_nlink,
1758                 from_kuid(&init_user_ns, ret->st_uid),
1759                 from_kgid(&init_user_ns, ret->st_gid),
1760                 ret->st_rdev, ret->st_size, ret->st_blksize,
1761                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1762                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1763                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1764                 ret->st_gen, ret->st_data_version);
1765
1766         p9_free_req(clnt, req);
1767         return ret;
1768
1769 error:
1770         kfree(ret);
1771         return ERR_PTR(err);
1772 }
1773 EXPORT_SYMBOL(p9_client_getattr_dotl);
1774
1775 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1776 {
1777         int ret;
1778
1779         /* NOTE: size shouldn't include its own length */
1780         /* size[2] type[2] dev[4] qid[13] */
1781         /* mode[4] atime[4] mtime[4] length[8]*/
1782         /* name[s] uid[s] gid[s] muid[s] */
1783         ret = 2+4+13+4+4+4+8+2+2+2+2;
1784
1785         if (wst->name)
1786                 ret += strlen(wst->name);
1787         if (wst->uid)
1788                 ret += strlen(wst->uid);
1789         if (wst->gid)
1790                 ret += strlen(wst->gid);
1791         if (wst->muid)
1792                 ret += strlen(wst->muid);
1793
1794         if ((proto_version == p9_proto_2000u) ||
1795                 (proto_version == p9_proto_2000L)) {
1796                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1797                 if (wst->extension)
1798                         ret += strlen(wst->extension);
1799         }
1800
1801         return ret;
1802 }
1803
1804 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1805 {
1806         int err;
1807         struct p9_req_t *req;
1808         struct p9_client *clnt;
1809
1810         err = 0;
1811         clnt = fid->clnt;
1812         wst->size = p9_client_statsize(wst, clnt->proto_version);
1813         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1814         p9_debug(P9_DEBUG_9P,
1815                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1816                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1817                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1818                 "     uid=%d gid=%d n_muid=%d\n",
1819                 wst->size, wst->type, wst->dev, wst->qid.type,
1820                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1821                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1822                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1823                 from_kuid(&init_user_ns, wst->n_uid),
1824                 from_kgid(&init_user_ns, wst->n_gid),
1825                 from_kuid(&init_user_ns, wst->n_muid));
1826
1827         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1828         if (IS_ERR(req)) {
1829                 err = PTR_ERR(req);
1830                 goto error;
1831         }
1832
1833         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1834
1835         p9_free_req(clnt, req);
1836 error:
1837         return err;
1838 }
1839 EXPORT_SYMBOL(p9_client_wstat);
1840
1841 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1842 {
1843         int err;
1844         struct p9_req_t *req;
1845         struct p9_client *clnt;
1846
1847         err = 0;
1848         clnt = fid->clnt;
1849         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1850         p9_debug(P9_DEBUG_9P,
1851                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1852                 "    atime_sec=%lld atime_nsec=%lld\n"
1853                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1854                 p9attr->valid, p9attr->mode,
1855                 from_kuid(&init_user_ns, p9attr->uid),
1856                 from_kgid(&init_user_ns, p9attr->gid),
1857                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1858                 p9attr->mtime_sec, p9attr->mtime_nsec);
1859
1860         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1861
1862         if (IS_ERR(req)) {
1863                 err = PTR_ERR(req);
1864                 goto error;
1865         }
1866         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1867         p9_free_req(clnt, req);
1868 error:
1869         return err;
1870 }
1871 EXPORT_SYMBOL(p9_client_setattr);
1872
1873 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1874 {
1875         int err;
1876         struct p9_req_t *req;
1877         struct p9_client *clnt;
1878
1879         err = 0;
1880         clnt = fid->clnt;
1881
1882         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1883
1884         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1885         if (IS_ERR(req)) {
1886                 err = PTR_ERR(req);
1887                 goto error;
1888         }
1889
1890         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1891                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1892                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1893         if (err) {
1894                 trace_9p_protocol_dump(clnt, req->rc);
1895                 p9_free_req(clnt, req);
1896                 goto error;
1897         }
1898
1899         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1900                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1901                 "fsid %llu namelen %ld\n",
1902                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1903                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1904                 sb->fsid, (long int)sb->namelen);
1905
1906         p9_free_req(clnt, req);
1907 error:
1908         return err;
1909 }
1910 EXPORT_SYMBOL(p9_client_statfs);
1911
1912 int p9_client_rename(struct p9_fid *fid,
1913                      struct p9_fid *newdirfid, const char *name)
1914 {
1915         int err;
1916         struct p9_req_t *req;
1917         struct p9_client *clnt;
1918
1919         err = 0;
1920         clnt = fid->clnt;
1921
1922         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1923                         fid->fid, newdirfid->fid, name);
1924
1925         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1926                         newdirfid->fid, name);
1927         if (IS_ERR(req)) {
1928                 err = PTR_ERR(req);
1929                 goto error;
1930         }
1931
1932         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1933
1934         p9_free_req(clnt, req);
1935 error:
1936         return err;
1937 }
1938 EXPORT_SYMBOL(p9_client_rename);
1939
1940 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1941                        struct p9_fid *newdirfid, const char *new_name)
1942 {
1943         int err;
1944         struct p9_req_t *req;
1945         struct p9_client *clnt;
1946
1947         err = 0;
1948         clnt = olddirfid->clnt;
1949
1950         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1951                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1952                    newdirfid->fid, new_name);
1953
1954         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1955                             old_name, newdirfid->fid, new_name);
1956         if (IS_ERR(req)) {
1957                 err = PTR_ERR(req);
1958                 goto error;
1959         }
1960
1961         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1962                    newdirfid->fid, new_name);
1963
1964         p9_free_req(clnt, req);
1965 error:
1966         return err;
1967 }
1968 EXPORT_SYMBOL(p9_client_renameat);
1969
1970 /*
1971  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1972  */
1973 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1974                                 const char *attr_name, u64 *attr_size)
1975 {
1976         int err;
1977         struct p9_req_t *req;
1978         struct p9_client *clnt;
1979         struct p9_fid *attr_fid;
1980
1981         err = 0;
1982         clnt = file_fid->clnt;
1983         attr_fid = p9_fid_create(clnt);
1984         if (IS_ERR(attr_fid)) {
1985                 err = PTR_ERR(attr_fid);
1986                 attr_fid = NULL;
1987                 goto error;
1988         }
1989         p9_debug(P9_DEBUG_9P,
1990                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1991                 file_fid->fid, attr_fid->fid, attr_name);
1992
1993         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1994                         file_fid->fid, attr_fid->fid, attr_name);
1995         if (IS_ERR(req)) {
1996                 err = PTR_ERR(req);
1997                 goto error;
1998         }
1999         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2000         if (err) {
2001                 trace_9p_protocol_dump(clnt, req->rc);
2002                 p9_free_req(clnt, req);
2003                 goto clunk_fid;
2004         }
2005         p9_free_req(clnt, req);
2006         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2007                 attr_fid->fid, *attr_size);
2008         return attr_fid;
2009 clunk_fid:
2010         p9_client_clunk(attr_fid);
2011         attr_fid = NULL;
2012 error:
2013         if (attr_fid && (attr_fid != file_fid))
2014                 p9_fid_destroy(attr_fid);
2015
2016         return ERR_PTR(err);
2017 }
2018 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2019
2020 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2021                         u64 attr_size, int flags)
2022 {
2023         int err;
2024         struct p9_req_t *req;
2025         struct p9_client *clnt;
2026
2027         p9_debug(P9_DEBUG_9P,
2028                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2029                 fid->fid, name, (long long)attr_size, flags);
2030         err = 0;
2031         clnt = fid->clnt;
2032         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2033                         fid->fid, name, attr_size, flags);
2034         if (IS_ERR(req)) {
2035                 err = PTR_ERR(req);
2036                 goto error;
2037         }
2038         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2039         p9_free_req(clnt, req);
2040 error:
2041         return err;
2042 }
2043 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2044
2045 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2046 {
2047         int err, rsize, non_zc = 0;
2048         struct p9_client *clnt;
2049         struct p9_req_t *req;
2050         char *dataptr;
2051         struct kvec kv = {.iov_base = data, .iov_len = count};
2052         struct iov_iter to;
2053
2054         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2055
2056         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2057                                 fid->fid, (unsigned long long) offset, count);
2058
2059         err = 0;
2060         clnt = fid->clnt;
2061
2062         rsize = fid->iounit;
2063         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2064                 rsize = clnt->msize - P9_READDIRHDRSZ;
2065
2066         if (count < rsize)
2067                 rsize = count;
2068
2069         /* Don't bother zerocopy for small IO (< 1024) */
2070         if (clnt->trans_mod->zc_request && rsize > 1024) {
2071                 /*
2072                  * response header len is 11
2073                  * PDU Header(7) + IO Size (4)
2074                  */
2075                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2076                                        11, "dqd", fid->fid, offset, rsize);
2077         } else {
2078                 non_zc = 1;
2079                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2080                                     offset, rsize);
2081         }
2082         if (IS_ERR(req)) {
2083                 err = PTR_ERR(req);
2084                 goto error;
2085         }
2086
2087         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2088         if (err) {
2089                 trace_9p_protocol_dump(clnt, req->rc);
2090                 goto free_and_error;
2091         }
2092
2093         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2094
2095         if (non_zc)
2096                 memmove(data, dataptr, count);
2097
2098         p9_free_req(clnt, req);
2099         return count;
2100
2101 free_and_error:
2102         p9_free_req(clnt, req);
2103 error:
2104         return err;
2105 }
2106 EXPORT_SYMBOL(p9_client_readdir);
2107
2108 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2109                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2110 {
2111         int err;
2112         struct p9_client *clnt;
2113         struct p9_req_t *req;
2114
2115         err = 0;
2116         clnt = fid->clnt;
2117         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2118                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2119         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2120                 MAJOR(rdev), MINOR(rdev), gid);
2121         if (IS_ERR(req))
2122                 return PTR_ERR(req);
2123
2124         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2125         if (err) {
2126                 trace_9p_protocol_dump(clnt, req->rc);
2127                 goto error;
2128         }
2129         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2130                                 (unsigned long long)qid->path, qid->version);
2131
2132 error:
2133         p9_free_req(clnt, req);
2134         return err;
2135
2136 }
2137 EXPORT_SYMBOL(p9_client_mknod_dotl);
2138
2139 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2140                                 kgid_t gid, struct p9_qid *qid)
2141 {
2142         int err;
2143         struct p9_client *clnt;
2144         struct p9_req_t *req;
2145
2146         err = 0;
2147         clnt = fid->clnt;
2148         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2149                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2150         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2151                 gid);
2152         if (IS_ERR(req))
2153                 return PTR_ERR(req);
2154
2155         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2156         if (err) {
2157                 trace_9p_protocol_dump(clnt, req->rc);
2158                 goto error;
2159         }
2160         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2161                                 (unsigned long long)qid->path, qid->version);
2162
2163 error:
2164         p9_free_req(clnt, req);
2165         return err;
2166
2167 }
2168 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2169
2170 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2171 {
2172         int err;
2173         struct p9_client *clnt;
2174         struct p9_req_t *req;
2175
2176         err = 0;
2177         clnt = fid->clnt;
2178         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2179                         "start %lld length %lld proc_id %d client_id %s\n",
2180                         fid->fid, flock->type, flock->flags, flock->start,
2181                         flock->length, flock->proc_id, flock->client_id);
2182
2183         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2184                                 flock->flags, flock->start, flock->length,
2185                                         flock->proc_id, flock->client_id);
2186
2187         if (IS_ERR(req))
2188                 return PTR_ERR(req);
2189
2190         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2191         if (err) {
2192                 trace_9p_protocol_dump(clnt, req->rc);
2193                 goto error;
2194         }
2195         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2196 error:
2197         p9_free_req(clnt, req);
2198         return err;
2199
2200 }
2201 EXPORT_SYMBOL(p9_client_lock_dotl);
2202
2203 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2204 {
2205         int err;
2206         struct p9_client *clnt;
2207         struct p9_req_t *req;
2208
2209         err = 0;
2210         clnt = fid->clnt;
2211         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2212                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2213                 glock->start, glock->length, glock->proc_id, glock->client_id);
2214
2215         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2216                 glock->start, glock->length, glock->proc_id, glock->client_id);
2217
2218         if (IS_ERR(req))
2219                 return PTR_ERR(req);
2220
2221         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2222                         &glock->start, &glock->length, &glock->proc_id,
2223                         &glock->client_id);
2224         if (err) {
2225                 trace_9p_protocol_dump(clnt, req->rc);
2226                 goto error;
2227         }
2228         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2229                 "proc_id %d client_id %s\n", glock->type, glock->start,
2230                 glock->length, glock->proc_id, glock->client_id);
2231 error:
2232         p9_free_req(clnt, req);
2233         return err;
2234 }
2235 EXPORT_SYMBOL(p9_client_getlock_dotl);
2236
2237 int p9_client_readlink(struct p9_fid *fid, char **target)
2238 {
2239         int err;
2240         struct p9_client *clnt;
2241         struct p9_req_t *req;
2242
2243         err = 0;
2244         clnt = fid->clnt;
2245         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2246
2247         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2248         if (IS_ERR(req))
2249                 return PTR_ERR(req);
2250
2251         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2252         if (err) {
2253                 trace_9p_protocol_dump(clnt, req->rc);
2254                 goto error;
2255         }
2256         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2257 error:
2258         p9_free_req(clnt, req);
2259         return err;
2260 }
2261 EXPORT_SYMBOL(p9_client_readlink);