net/9p/client.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * net/9p/clnt.c
   4  *
   5  * 9P Client
   6  *
   7  *  Copyright (C) 2008 by Eric Van Hensbergen <[email protected]>
   8  *  Copyright (C) 2007 by Latchesar Ionkov <[email protected]>
   9  */
  10
  11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13 #include <linux/module.h>
  14 #include <linux/errno.h>
  15 #include <linux/fs.h>
  16 #include <linux/poll.h>
  17 #include <linux/idr.h>
  18 #include <linux/mutex.h>
  19 #include <linux/slab.h>
  20 #include <linux/sched/signal.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/uio.h>
  23 #include <net/9p/9p.h>
  24 #include <linux/parser.h>
  25 #include <linux/seq_file.h>
  26 #include <net/9p/client.h>
  27 #include <net/9p/transport.h>
  28 #include "protocol.h"
  29
  30 #define CREATE_TRACE_POINTS
  31 #include <trace/events/9p.h>
  32
  33 /*
  34   * Client Option Parsing (code inspired by NFS code)
  35   *  - a little lazy - parse all client options
  36   */
  37
  38 enum {
  39         Opt_msize,
  40         Opt_trans,
  41         Opt_legacy,
  42         Opt_version,
  43         Opt_err,
  44 };
  45
  46 static const match_table_t tokens = {
  47         {Opt_msize, "msize=%u"},
  48         {Opt_legacy, "noextend"},
  49         {Opt_trans, "trans=%s"},
  50         {Opt_version, "version=%s"},
  51         {Opt_err, NULL},
  52 };
  53
  54 inline int p9_is_proto_dotl(struct p9_client *clnt)
  55 {
  56         return clnt->proto_version == p9_proto_2000L;
  57 }
  58 EXPORT_SYMBOL(p9_is_proto_dotl);
  59
  60 inline int p9_is_proto_dotu(struct p9_client *clnt)
  61 {
  62         return clnt->proto_version == p9_proto_2000u;
  63 }
  64 EXPORT_SYMBOL(p9_is_proto_dotu);
  65
  66 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
  67 {
  68         if (clnt->msize != 8192)
  69                 seq_printf(m, ",msize=%u", clnt->msize);
  70         seq_printf(m, ",trans=%s", clnt->trans_mod->name);
  71
  72         switch (clnt->proto_version) {
  73         case p9_proto_legacy:
  74                 seq_puts(m, ",noextend");
  75                 break;
  76         case p9_proto_2000u:
  77                 seq_puts(m, ",version=9p2000.u");
  78                 break;
  79         case p9_proto_2000L:
  80                 /* Default */
  81                 break;
  82         }
  83
  84         if (clnt->trans_mod->show_options)
  85                 return clnt->trans_mod->show_options(m, clnt);
  86         return 0;
  87 }
  88 EXPORT_SYMBOL(p9_show_client_options);
  89
  90 /*
  91  * Some error codes are taken directly from the server replies,
  92  * make sure they are valid.
  93  */
  94 static int safe_errno(int err)
  95 {
  96         if ((err > 0) || (err < -MAX_ERRNO)) {
  97                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
  98                 return -EPROTO;
  99         }
 100         return err;
 101 }
 102
 103
 104 /* Interpret mount option for protocol version */
 105 static int get_protocol_version(char *s)
 106 {
 107         int version = -EINVAL;
 108
 109         if (!strcmp(s, "9p2000")) {
 110                 version = p9_proto_legacy;
 111                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
 112         } else if (!strcmp(s, "9p2000.u")) {
 113                 version = p9_proto_2000u;
 114                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
 115         } else if (!strcmp(s, "9p2000.L")) {
 116                 version = p9_proto_2000L;
 117                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
 118         } else
 119                 pr_info("Unknown protocol version %s\n", s);
 120
 121         return version;
 122 }
 123
 124 /**
 125  * parse_options - parse mount options into client structure
 126  * @opts: options string passed from mount
 127  * @clnt: existing v9fs client information
 128  *
 129  * Return 0 upon success, -ERRNO upon failure
 130  */
 131
 132 static int parse_opts(char *opts, struct p9_client *clnt)
 133 {
 134         char *options, *tmp_options;
 135         char *p;
 136         substring_t args[MAX_OPT_ARGS];
 137         int option;
 138         char *s;
 139         int ret = 0;
 140
 141         clnt->proto_version = p9_proto_2000L;
 142         clnt->msize = 8192;
 143
 144         if (!opts)
 145                 return 0;
 146
 147         tmp_options = kstrdup(opts, GFP_KERNEL);
 148         if (!tmp_options) {
 149                 p9_debug(P9_DEBUG_ERROR,
 150                          "failed to allocate copy of option string\n");
 151                 return -ENOMEM;
 152         }
 153         options = tmp_options;
 154
 155         while ((p = strsep(&options, ",")) != NULL) {
 156                 int token, r;
 157                 if (!*p)
 158                         continue;
 159                 token = match_token(p, tokens, args);
 160                 switch (token) {
 161                 case Opt_msize:
 162                         r = match_int(&args[0], &option);
 163                         if (r < 0) {
 164                                 p9_debug(P9_DEBUG_ERROR,
 165                                          "integer field, but no integer?\n");
 166                                 ret = r;
 167                                 continue;
 168                         }
 169                         if (option < 4096) {
 170                                 p9_debug(P9_DEBUG_ERROR,
 171                                          "msize should be at least 4k\n");
 172                                 ret = -EINVAL;
 173                                 continue;
 174                         }
 175                         clnt->msize = option;
 176                         break;
 177                 case Opt_trans:
 178                         s = match_strdup(&args[0]);
 179                         if (!s) {
 180                                 ret = -ENOMEM;
 181                                 p9_debug(P9_DEBUG_ERROR,
 182                                          "problem allocating copy of trans arg\n");
 183                                 goto free_and_return;
 184                         }
 185
 186                         v9fs_put_trans(clnt->trans_mod);
 187                         clnt->trans_mod = v9fs_get_trans_by_name(s);
 188                         if (clnt->trans_mod == NULL) {
 189                                 pr_info("Could not find request transport: %s\n",
 190                                         s);
 191                                 ret = -EINVAL;
 192                         }
 193                         kfree(s);
 194                         break;
 195                 case Opt_legacy:
 196                         clnt->proto_version = p9_proto_legacy;
 197                         break;
 198                 case Opt_version:
 199                         s = match_strdup(&args[0]);
 200                         if (!s) {
 201                                 ret = -ENOMEM;
 202                                 p9_debug(P9_DEBUG_ERROR,
 203                                          "problem allocating copy of version arg\n");
 204                                 goto free_and_return;
 205                         }
 206                         r = get_protocol_version(s);
 207                         if (r < 0)
 208                                 ret = r;
 209                         else
 210                                 clnt->proto_version = r;
 211                         kfree(s);
 212                         break;
 213                 default:
 214                         continue;
 215                 }
 216         }
 217
 218 free_and_return:
 219         if (ret)
 220                 v9fs_put_trans(clnt->trans_mod);
 221         kfree(tmp_options);
 222         return ret;
 223 }
 224
 225 static int p9_fcall_init(struct p9_client *c, struct p9_fcall *fc,
 226                          int alloc_msize)
 227 {
 228         if (likely(c->fcall_cache) && alloc_msize == c->msize) {
 229                 fc->sdata = kmem_cache_alloc(c->fcall_cache, GFP_NOFS);
 230                 fc->cache = c->fcall_cache;
 231         } else {
 232                 fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
 233                 fc->cache = NULL;
 234         }
 235         if (!fc->sdata)
 236                 return -ENOMEM;
 237         fc->capacity = alloc_msize;
 238         return 0;
 239 }
 240
 241 void p9_fcall_fini(struct p9_fcall *fc)
 242 {
 243         /* sdata can be NULL for interrupted requests in trans_rdma,
 244          * and kmem_cache_free does not do NULL-check for us
 245          */
 246         if (unlikely(!fc->sdata))
 247                 return;
 248
 249         if (fc->cache)
 250                 kmem_cache_free(fc->cache, fc->sdata);
 251         else
 252                 kfree(fc->sdata);
 253 }
 254 EXPORT_SYMBOL(p9_fcall_fini);
 255
 256 static struct kmem_cache *p9_req_cache;
 257
 258 /**
 259  * p9_req_alloc - Allocate a new request.
 260  * @c: Client session.
 261  * @type: Transaction type.
 262  * @max_size: Maximum packet size for this request.
 263  *
 264  * Context: Process context.
 265  * Return: Pointer to new request.
 266  */
 267 static struct p9_req_t *
 268 p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
 269 {
 270         struct p9_req_t *req = kmem_cache_alloc(p9_req_cache, GFP_NOFS);
 271         int alloc_msize = min(c->msize, max_size);
 272         int tag;
 273
 274         if (!req)
 275                 return ERR_PTR(-ENOMEM);
 276
 277         if (p9_fcall_init(c, &req->tc, alloc_msize))
 278                 goto free_req;
 279         if (p9_fcall_init(c, &req->rc, alloc_msize))
 280                 goto free;
 281
 282         p9pdu_reset(&req->tc);
 283         p9pdu_reset(&req->rc);
 284         req->status = REQ_STATUS_ALLOC;
 285         init_waitqueue_head(&req->wq);
 286         INIT_LIST_HEAD(&req->req_list);
 287
 288         idr_preload(GFP_NOFS);
 289         spin_lock_irq(&c->lock);
 290         if (type == P9_TVERSION)
 291                 tag = idr_alloc(&c->reqs, req, P9_NOTAG, P9_NOTAG + 1,
 292                                 GFP_NOWAIT);
 293         else
 294                 tag = idr_alloc(&c->reqs, req, 0, P9_NOTAG, GFP_NOWAIT);
 295         req->tc.tag = tag;
 296         spin_unlock_irq(&c->lock);
 297         idr_preload_end();
 298         if (tag < 0)
 299                 goto free;
 300
 301         /* Init ref to two because in the general case there is one ref
 302          * that is put asynchronously by a writer thread, one ref
 303          * temporarily given by p9_tag_lookup and put by p9_client_cb
 304          * in the recv thread, and one ref put by p9_tag_remove in the
 305          * main thread. The only exception is virtio that does not use
 306          * p9_tag_lookup but does not have a writer thread either
 307          * (the write happens synchronously in the request/zc_request
 308          * callback), so p9_client_cb eats the second ref there
 309          * as the pointer is duplicated directly by virtqueue_add_sgs()
 310          */
 311         refcount_set(&req->refcount.refcount, 2);
 312
 313         return req;
 314
 315 free:
 316         p9_fcall_fini(&req->tc);
 317         p9_fcall_fini(&req->rc);
 318 free_req:
 319         kmem_cache_free(p9_req_cache, req);
 320         return ERR_PTR(-ENOMEM);
 321 }
 322
 323 /**
 324  * p9_tag_lookup - Look up a request by tag.
 325  * @c: Client session.
 326  * @tag: Transaction ID.
 327  *
 328  * Context: Any context.
 329  * Return: A request, or %NULL if there is no request with that tag.
 330  */
 331 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 332 {
 333         struct p9_req_t *req;
 334
 335         rcu_read_lock();
 336 again:
 337         req = idr_find(&c->reqs, tag);
 338         if (req) {
 339                 /* We have to be careful with the req found under rcu_read_lock
 340                  * Thanks to SLAB_TYPESAFE_BY_RCU we can safely try to get the
 341                  * ref again without corrupting other data, then check again
 342                  * that the tag matches once we have the ref
 343                  */
 344                 if (!p9_req_try_get(req))
 345                         goto again;
 346                 if (req->tc.tag != tag) {
 347                         p9_req_put(req);
 348                         goto again;
 349                 }
 350         }
 351         rcu_read_unlock();
 352
 353         return req;
 354 }
 355 EXPORT_SYMBOL(p9_tag_lookup);
 356
 357 /**
 358  * p9_tag_remove - Remove a tag.
 359  * @c: Client session.
 360  * @r: Request of reference.
 361  *
 362  * Context: Any context.
 363  */
 364 static int p9_tag_remove(struct p9_client *c, struct p9_req_t *r)
 365 {
 366         unsigned long flags;
 367         u16 tag = r->tc.tag;
 368
 369         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 370         spin_lock_irqsave(&c->lock, flags);
 371         idr_remove(&c->reqs, tag);
 372         spin_unlock_irqrestore(&c->lock, flags);
 373         return p9_req_put(r);
 374 }
 375
 376 static void p9_req_free(struct kref *ref)
 377 {
 378         struct p9_req_t *r = container_of(ref, struct p9_req_t, refcount);
 379         p9_fcall_fini(&r->tc);
 380         p9_fcall_fini(&r->rc);
 381         kmem_cache_free(p9_req_cache, r);
 382 }
 383
 384 int p9_req_put(struct p9_req_t *r)
 385 {
 386         return kref_put(&r->refcount, p9_req_free);
 387 }
 388 EXPORT_SYMBOL(p9_req_put);
 389
 390 /**
 391  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 392  * @c:  v9fs client struct
 393  *
 394  * This frees resources associated with the tags structure
 395  *
 396  */
 397 static void p9_tag_cleanup(struct p9_client *c)
 398 {
 399         struct p9_req_t *req;
 400         int id;
 401
 402         rcu_read_lock();
 403         idr_for_each_entry(&c->reqs, req, id) {
 404                 pr_info("Tag %d still in use\n", id);
 405                 if (p9_tag_remove(c, req) == 0)
 406                         pr_warn("Packet with tag %d has still references",
 407                                 req->tc.tag);
 408         }
 409         rcu_read_unlock();
 410 }
 411
 412 /**
 413  * p9_client_cb - call back from transport to client
 414  * c: client state
 415  * req: request received
 416  *
 417  */
 418 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 419 {
 420         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc.tag);
 421
 422         /*
 423          * This barrier is needed to make sure any change made to req before
 424          * the status change is visible to another thread
 425          */
 426         smp_wmb();
 427         req->status = status;
 428
 429         wake_up(&req->wq);
 430         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc.tag);
 431         p9_req_put(req);
 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
 456         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 457         if (err)
 458                 goto rewind_and_exit;
 459
 460         if (type)
 461                 *type = r_type;
 462         if (tag)
 463                 *tag = r_tag;
 464         if (size)
 465                 *size = r_size;
 466
 467         if (pdu->size != r_size || r_size < 7) {
 468                 err = -EINVAL;
 469                 goto rewind_and_exit;
 470         }
 471
 472         pdu->id = r_type;
 473         pdu->tag = r_tag;
 474
 475         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 476                  pdu->size, pdu->id, pdu->tag);
 477
 478 rewind_and_exit:
 479         if (rewind)
 480                 pdu->offset = offset;
 481         return err;
 482 }
 483 EXPORT_SYMBOL(p9_parse_header);
 484
 485 /**
 486  * p9_check_errors - check 9p packet for error return and process it
 487  * @c: current client instance
 488  * @req: request to parse and check for error conditions
 489  *
 490  * returns error code if one is discovered, otherwise returns 0
 491  *
 492  * this will have to be more complicated if we have multiple
 493  * error packet types
 494  */
 495
 496 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 497 {
 498         int8_t type;
 499         int err;
 500         int ecode;
 501
 502         err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
 503         if (req->rc.size >= c->msize) {
 504                 p9_debug(P9_DEBUG_ERROR,
 505                          "requested packet size too big: %d\n",
 506                          req->rc.size);
 507                 return -EIO;
 508         }
 509         /*
 510          * dump the response from server
 511          * This should be after check errors which poplulate pdu_fcall.
 512          */
 513         trace_9p_protocol_dump(c, &req->rc);
 514         if (err) {
 515                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 516                 return err;
 517         }
 518         if (type != P9_RERROR && type != P9_RLERROR)
 519                 return 0;
 520
 521         if (!p9_is_proto_dotl(c)) {
 522                 char *ename;
 523                 err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
 524                                   &ename, &ecode);
 525                 if (err)
 526                         goto out_err;
 527
 528                 if (p9_is_proto_dotu(c) && ecode < 512)
 529                         err = -ecode;
 530
 531                 if (!err) {
 532                         err = p9_errstr2errno(ename, strlen(ename));
 533
 534                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 535                                  -ecode, ename);
 536                 }
 537                 kfree(ename);
 538         } else {
 539                 err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
 540                 err = -ecode;
 541
 542                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 543         }
 544
 545         return err;
 546
 547 out_err:
 548         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 549
 550         return err;
 551 }
 552
 553 /**
 554  * p9_check_zc_errors - check 9p packet for error return and process it
 555  * @c: current client instance
 556  * @req: request to parse and check for error conditions
 557  * @in_hdrlen: Size of response protocol buffer.
 558  *
 559  * returns error code if one is discovered, otherwise returns 0
 560  *
 561  * this will have to be more complicated if we have multiple
 562  * error packet types
 563  */
 564
 565 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 566                               struct iov_iter *uidata, int in_hdrlen)
 567 {
 568         int err;
 569         int ecode;
 570         int8_t type;
 571         char *ename = NULL;
 572
 573         err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
 574         /*
 575          * dump the response from server
 576          * This should be after parse_header which poplulate pdu_fcall.
 577          */
 578         trace_9p_protocol_dump(c, &req->rc);
 579         if (err) {
 580                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 581                 return err;
 582         }
 583
 584         if (type != P9_RERROR && type != P9_RLERROR)
 585                 return 0;
 586
 587         if (!p9_is_proto_dotl(c)) {
 588                 /* Error is reported in string format */
 589                 int len;
 590                 /* 7 = header size for RERROR; */
 591                 int inline_len = in_hdrlen - 7;
 592
 593                 len = req->rc.size - req->rc.offset;
 594                 if (len > (P9_ZC_HDR_SZ - 7)) {
 595                         err = -EFAULT;
 596                         goto out_err;
 597                 }
 598
 599                 ename = &req->rc.sdata[req->rc.offset];
 600                 if (len > inline_len) {
 601                         /* We have error in external buffer */
 602                         if (!copy_from_iter_full(ename + inline_len,
 603                                              len - inline_len, uidata)) {
 604                                 err = -EFAULT;
 605                                 goto out_err;
 606                         }
 607                 }
 608                 ename = NULL;
 609                 err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
 610                                   &ename, &ecode);
 611                 if (err)
 612                         goto out_err;
 613
 614                 if (p9_is_proto_dotu(c) && ecode < 512)
 615                         err = -ecode;
 616
 617                 if (!err) {
 618                         err = p9_errstr2errno(ename, strlen(ename));
 619
 620                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 621                                  -ecode, ename);
 622                 }
 623                 kfree(ename);
 624         } else {
 625                 err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
 626                 err = -ecode;
 627
 628                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 629         }
 630         return err;
 631
 632 out_err:
 633         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 634         return err;
 635 }
 636
 637 static struct p9_req_t *
 638 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 639
 640 /**
 641  * p9_client_flush - flush (cancel) a request
 642  * @c: client state
 643  * @oldreq: request to cancel
 644  *
 645  * This sents a flush for a particular request and links
 646  * the flush request to the original request.  The current
 647  * code only supports a single flush request although the protocol
 648  * allows for multiple flush requests to be sent for a single request.
 649  *
 650  */
 651
 652 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 653 {
 654         struct p9_req_t *req;
 655         int16_t oldtag;
 656         int err;
 657
 658         err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
 659         if (err)
 660                 return err;
 661
 662         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 663
 664         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 665         if (IS_ERR(req))
 666                 return PTR_ERR(req);
 667
 668         /*
 669          * if we haven't received a response for oldreq,
 670          * remove it from the list
 671          */
 672         if (oldreq->status == REQ_STATUS_SENT) {
 673                 if (c->trans_mod->cancelled)
 674                         c->trans_mod->cancelled(c, oldreq);
 675         }
 676
 677         p9_tag_remove(c, req);
 678         return 0;
 679 }
 680
 681 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 682                                               int8_t type, int req_size,
 683                                               const char *fmt, va_list ap)
 684 {
 685         int err;
 686         struct p9_req_t *req;
 687
 688         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 689
 690         /* we allow for any status other than disconnected */
 691         if (c->status == Disconnected)
 692                 return ERR_PTR(-EIO);
 693
 694         /* if status is begin_disconnected we allow only clunk request */
 695         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 696                 return ERR_PTR(-EIO);
 697
 698         req = p9_tag_alloc(c, type, req_size);
 699         if (IS_ERR(req))
 700                 return req;
 701
 702         /* marshall the data */
 703         p9pdu_prepare(&req->tc, 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, req->tc.tag);
 709         return req;
 710 reterr:
 711         p9_tag_remove(c, req);
 712         /* We have to put also the 2nd reference as it won't be used */
 713         p9_req_put(req);
 714         return ERR_PTR(err);
 715 }
 716
 717 /**
 718  * p9_client_rpc - issue a request and wait for a response
 719  * @c: client session
 720  * @type: type of request
 721  * @fmt: protocol format string (see protocol.c)
 722  *
 723  * Returns request structure (which client must free using p9_tag_remove)
 724  */
 725
 726 static struct p9_req_t *
 727 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 728 {
 729         va_list ap;
 730         int sigpending, err;
 731         unsigned long flags;
 732         struct p9_req_t *req;
 733
 734         va_start(ap, fmt);
 735         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 736         va_end(ap);
 737         if (IS_ERR(req))
 738                 return req;
 739
 740         if (signal_pending(current)) {
 741                 sigpending = 1;
 742                 clear_thread_flag(TIF_SIGPENDING);
 743         } else
 744                 sigpending = 0;
 745
 746         err = c->trans_mod->request(c, req);
 747         if (err < 0) {
 748                 /* write won't happen */
 749                 p9_req_put(req);
 750                 if (err != -ERESTARTSYS && err != -EFAULT)
 751                         c->status = Disconnected;
 752                 goto recalc_sigpending;
 753         }
 754 again:
 755         /* Wait for the response */
 756         err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
 757
 758         /*
 759          * Make sure our req is coherent with regard to updates in other
 760          * threads - echoes to wmb() in the callback
 761          */
 762         smp_rmb();
 763
 764         if ((err == -ERESTARTSYS) && (c->status == Connected)
 765                                   && (type == P9_TFLUSH)) {
 766                 sigpending = 1;
 767                 clear_thread_flag(TIF_SIGPENDING);
 768                 goto again;
 769         }
 770
 771         if (req->status == REQ_STATUS_ERROR) {
 772                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 773                 err = req->t_err;
 774         }
 775         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 776                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 777                 sigpending = 1;
 778                 clear_thread_flag(TIF_SIGPENDING);
 779
 780                 if (c->trans_mod->cancel(c, req))
 781                         p9_client_flush(c, req);
 782
 783                 /* if we received the response anyway, don't signal error */
 784                 if (req->status == REQ_STATUS_RCVD)
 785                         err = 0;
 786         }
 787 recalc_sigpending:
 788         if (sigpending) {
 789                 spin_lock_irqsave(&current->sighand->siglock, flags);
 790                 recalc_sigpending();
 791                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 792         }
 793         if (err < 0)
 794                 goto reterr;
 795
 796         err = p9_check_errors(c, req);
 797         trace_9p_client_res(c, type, req->rc.tag, err);
 798         if (!err)
 799                 return req;
 800 reterr:
 801         p9_tag_remove(c, req);
 802         return ERR_PTR(safe_errno(err));
 803 }
 804
 805 /**
 806  * p9_client_zc_rpc - issue a request and wait for a response
 807  * @c: client session
 808  * @type: type of request
 809  * @uidata: destination for zero copy read
 810  * @uodata: source for zero copy write
 811  * @inlen: read buffer size
 812  * @olen: write buffer size
 813  * @hdrlen: reader header size, This is the size of response protocol data
 814  * @fmt: protocol format string (see protocol.c)
 815  *
 816  * Returns request structure (which client must free using p9_tag_remove)
 817  */
 818 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 819                                          struct iov_iter *uidata,
 820                                          struct iov_iter *uodata,
 821                                          int inlen, int olen, int in_hdrlen,
 822                                          const char *fmt, ...)
 823 {
 824         va_list ap;
 825         int sigpending, err;
 826         unsigned long flags;
 827         struct p9_req_t *req;
 828
 829         va_start(ap, fmt);
 830         /*
 831          * We allocate a inline protocol data of only 4k bytes.
 832          * The actual content is passed in zero-copy fashion.
 833          */
 834         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 835         va_end(ap);
 836         if (IS_ERR(req))
 837                 return req;
 838
 839         if (signal_pending(current)) {
 840                 sigpending = 1;
 841                 clear_thread_flag(TIF_SIGPENDING);
 842         } else
 843                 sigpending = 0;
 844
 845         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 846                                        inlen, olen, in_hdrlen);
 847         if (err < 0) {
 848                 if (err == -EIO)
 849                         c->status = Disconnected;
 850                 if (err != -ERESTARTSYS)
 851                         goto recalc_sigpending;
 852         }
 853         if (req->status == REQ_STATUS_ERROR) {
 854                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 855                 err = req->t_err;
 856         }
 857         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 858                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 859                 sigpending = 1;
 860                 clear_thread_flag(TIF_SIGPENDING);
 861
 862                 if (c->trans_mod->cancel(c, req))
 863                         p9_client_flush(c, req);
 864
 865                 /* if we received the response anyway, don't signal error */
 866                 if (req->status == REQ_STATUS_RCVD)
 867                         err = 0;
 868         }
 869 recalc_sigpending:
 870         if (sigpending) {
 871                 spin_lock_irqsave(&current->sighand->siglock, flags);
 872                 recalc_sigpending();
 873                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 874         }
 875         if (err < 0)
 876                 goto reterr;
 877
 878         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 879         trace_9p_client_res(c, type, req->rc.tag, err);
 880         if (!err)
 881                 return req;
 882 reterr:
 883         p9_tag_remove(c, req);
 884         return ERR_PTR(safe_errno(err));
 885 }
 886
 887 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 888 {
 889         int ret;
 890         struct p9_fid *fid;
 891
 892         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 893         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 894         if (!fid)
 895                 return NULL;
 896
 897         memset(&fid->qid, 0, sizeof(struct p9_qid));
 898         fid->mode = -1;
 899         fid->uid = current_fsuid();
 900         fid->clnt = clnt;
 901         fid->rdir = NULL;
 902         fid->fid = 0;
 903
 904         idr_preload(GFP_KERNEL);
 905         spin_lock_irq(&clnt->lock);
 906         ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
 907                             GFP_NOWAIT);
 908         spin_unlock_irq(&clnt->lock);
 909         idr_preload_end();
 910
 911         if (!ret)
 912                 return fid;
 913
 914         kfree(fid);
 915         return NULL;
 916 }
 917
 918 static void p9_fid_destroy(struct p9_fid *fid)
 919 {
 920         struct p9_client *clnt;
 921         unsigned long flags;
 922
 923         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 924         clnt = fid->clnt;
 925         spin_lock_irqsave(&clnt->lock, flags);
 926         idr_remove(&clnt->fids, fid->fid);
 927         spin_unlock_irqrestore(&clnt->lock, flags);
 928         kfree(fid->rdir);
 929         kfree(fid);
 930 }
 931
 932 static int p9_client_version(struct p9_client *c)
 933 {
 934         int err = 0;
 935         struct p9_req_t *req;
 936         char *version = NULL;
 937         int msize;
 938
 939         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 940                  c->msize, c->proto_version);
 941
 942         switch (c->proto_version) {
 943         case p9_proto_2000L:
 944                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 945                                         c->msize, "9P2000.L");
 946                 break;
 947         case p9_proto_2000u:
 948                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 949                                         c->msize, "9P2000.u");
 950                 break;
 951         case p9_proto_legacy:
 952                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 953                                         c->msize, "9P2000");
 954                 break;
 955         default:
 956                 return -EINVAL;
 957         }
 958
 959         if (IS_ERR(req))
 960                 return PTR_ERR(req);
 961
 962         err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version);
 963         if (err) {
 964                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 965                 trace_9p_protocol_dump(c, &req->rc);
 966                 goto error;
 967         }
 968
 969         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 970         if (!strncmp(version, "9P2000.L", 8))
 971                 c->proto_version = p9_proto_2000L;
 972         else if (!strncmp(version, "9P2000.u", 8))
 973                 c->proto_version = p9_proto_2000u;
 974         else if (!strncmp(version, "9P2000", 6))
 975                 c->proto_version = p9_proto_legacy;
 976         else {
 977                 p9_debug(P9_DEBUG_ERROR,
 978                          "server returned an unknown version: %s\n", version);
 979                 err = -EREMOTEIO;
 980                 goto error;
 981         }
 982
 983         if (msize < 4096) {
 984                 p9_debug(P9_DEBUG_ERROR,
 985                          "server returned a msize < 4096: %d\n", msize);
 986                 err = -EREMOTEIO;
 987                 goto error;
 988         }
 989         if (msize < c->msize)
 990                 c->msize = msize;
 991
 992 error:
 993         kfree(version);
 994         p9_tag_remove(c, req);
 995
 996         return err;
 997 }
 998
 999 struct p9_client *p9_client_create(const char *dev_name, char *options)
1000 {
1001         int err;
1002         struct p9_client *clnt;
1003         char *client_id;
1004
1005         err = 0;
1006         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1007         if (!clnt)
1008                 return ERR_PTR(-ENOMEM);
1009
1010         clnt->trans_mod = NULL;
1011         clnt->trans = NULL;
1012         clnt->fcall_cache = NULL;
1013
1014         client_id = utsname()->nodename;
1015         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1016
1017         spin_lock_init(&clnt->lock);
1018         idr_init(&clnt->fids);
1019         idr_init(&clnt->reqs);
1020
1021         err = parse_opts(options, clnt);
1022         if (err < 0)
1023                 goto free_client;
1024
1025         if (!clnt->trans_mod)
1026                 clnt->trans_mod = v9fs_get_default_trans();
1027
1028         if (clnt->trans_mod == NULL) {
1029                 err = -EPROTONOSUPPORT;
1030                 p9_debug(P9_DEBUG_ERROR,
1031                          "No transport defined or default transport\n");
1032                 goto free_client;
1033         }
1034
1035         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1036                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1037
1038         err = clnt->trans_mod->create(clnt, dev_name, options);
1039         if (err)
1040                 goto put_trans;
1041
1042         if (clnt->msize > clnt->trans_mod->maxsize)
1043                 clnt->msize = clnt->trans_mod->maxsize;
1044
1045         if (clnt->msize < 4096) {
1046                 p9_debug(P9_DEBUG_ERROR,
1047                          "Please specify a msize of at least 4k\n");
1048                 err = -EINVAL;
1049                 goto close_trans;
1050         }
1051
1052         err = p9_client_version(clnt);
1053         if (err)
1054                 goto close_trans;
1055
1056         /* P9_HDRSZ + 4 is the smallest packet header we can have that is
1057          * followed by data accessed from userspace by read
1058          */
1059         clnt->fcall_cache =
1060                 kmem_cache_create_usercopy("9p-fcall-cache", clnt->msize,
1061                                            0, 0, P9_HDRSZ + 4,
1062                                            clnt->msize - (P9_HDRSZ + 4),
1063                                            NULL);
1064
1065         return clnt;
1066
1067 close_trans:
1068         clnt->trans_mod->close(clnt);
1069 put_trans:
1070         v9fs_put_trans(clnt->trans_mod);
1071 free_client:
1072         kfree(clnt);
1073         return ERR_PTR(err);
1074 }
1075 EXPORT_SYMBOL(p9_client_create);
1076
1077 void p9_client_destroy(struct p9_client *clnt)
1078 {
1079         struct p9_fid *fid;
1080         int id;
1081
1082         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1083
1084         if (clnt->trans_mod)
1085                 clnt->trans_mod->close(clnt);
1086
1087         v9fs_put_trans(clnt->trans_mod);
1088
1089         idr_for_each_entry(&clnt->fids, fid, id) {
1090                 pr_info("Found fid %d not clunked\n", fid->fid);
1091                 p9_fid_destroy(fid);
1092         }
1093
1094         p9_tag_cleanup(clnt);
1095
1096         kmem_cache_destroy(clnt->fcall_cache);
1097         kfree(clnt);
1098 }
1099 EXPORT_SYMBOL(p9_client_destroy);
1100
1101 void p9_client_disconnect(struct p9_client *clnt)
1102 {
1103         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1104         clnt->status = Disconnected;
1105 }
1106 EXPORT_SYMBOL(p9_client_disconnect);
1107
1108 void p9_client_begin_disconnect(struct p9_client *clnt)
1109 {
1110         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1111         clnt->status = BeginDisconnect;
1112 }
1113 EXPORT_SYMBOL(p9_client_begin_disconnect);
1114
1115 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1116         const char *uname, kuid_t n_uname, const char *aname)
1117 {
1118         int err = 0;
1119         struct p9_req_t *req;
1120         struct p9_fid *fid;
1121         struct p9_qid qid;
1122
1123
1124         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1125                  afid ? afid->fid : -1, uname, aname);
1126         fid = p9_fid_create(clnt);
1127         if (!fid) {
1128                 err = -ENOMEM;
1129                 goto error;
1130         }
1131         fid->uid = n_uname;
1132
1133         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1134                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1135         if (IS_ERR(req)) {
1136                 err = PTR_ERR(req);
1137                 goto error;
1138         }
1139
1140         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
1141         if (err) {
1142                 trace_9p_protocol_dump(clnt, &req->rc);
1143                 p9_tag_remove(clnt, req);
1144                 goto error;
1145         }
1146
1147         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1148                  qid.type, (unsigned long long)qid.path, qid.version);
1149
1150         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1151
1152         p9_tag_remove(clnt, req);
1153         return fid;
1154
1155 error:
1156         if (fid)
1157                 p9_fid_destroy(fid);
1158         return ERR_PTR(err);
1159 }
1160 EXPORT_SYMBOL(p9_client_attach);
1161
1162 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1163                 const unsigned char * const *wnames, int clone)
1164 {
1165         int err;
1166         struct p9_client *clnt;
1167         struct p9_fid *fid;
1168         struct p9_qid *wqids;
1169         struct p9_req_t *req;
1170         uint16_t nwqids, count;
1171
1172         err = 0;
1173         wqids = NULL;
1174         clnt = oldfid->clnt;
1175         if (clone) {
1176                 fid = p9_fid_create(clnt);
1177                 if (!fid) {
1178                         err = -ENOMEM;
1179                         goto error;
1180                 }
1181
1182                 fid->uid = oldfid->uid;
1183         } else
1184                 fid = oldfid;
1185
1186
1187         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1188                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1189
1190         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1191                                                                 nwname, wnames);
1192         if (IS_ERR(req)) {
1193                 err = PTR_ERR(req);
1194                 goto error;
1195         }
1196
1197         err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1198         if (err) {
1199                 trace_9p_protocol_dump(clnt, &req->rc);
1200                 p9_tag_remove(clnt, req);
1201                 goto clunk_fid;
1202         }
1203         p9_tag_remove(clnt, req);
1204
1205         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1206
1207         if (nwqids != nwname) {
1208                 err = -ENOENT;
1209                 goto clunk_fid;
1210         }
1211
1212         for (count = 0; count < nwqids; count++)
1213                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1214                         count, wqids[count].type,
1215                         (unsigned long long)wqids[count].path,
1216                         wqids[count].version);
1217
1218         if (nwname)
1219                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1220         else
1221                 fid->qid = oldfid->qid;
1222
1223         kfree(wqids);
1224         return fid;
1225
1226 clunk_fid:
1227         kfree(wqids);
1228         p9_client_clunk(fid);
1229         fid = NULL;
1230
1231 error:
1232         if (fid && (fid != oldfid))
1233                 p9_fid_destroy(fid);
1234
1235         return ERR_PTR(err);
1236 }
1237 EXPORT_SYMBOL(p9_client_walk);
1238
1239 int p9_client_open(struct p9_fid *fid, int mode)
1240 {
1241         int err;
1242         struct p9_client *clnt;
1243         struct p9_req_t *req;
1244         struct p9_qid qid;
1245         int iounit;
1246
1247         clnt = fid->clnt;
1248         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1249                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1250         err = 0;
1251
1252         if (fid->mode != -1)
1253                 return -EINVAL;
1254
1255         if (p9_is_proto_dotl(clnt))
1256                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1257         else
1258                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1259         if (IS_ERR(req)) {
1260                 err = PTR_ERR(req);
1261                 goto error;
1262         }
1263
1264         err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1265         if (err) {
1266                 trace_9p_protocol_dump(clnt, &req->rc);
1267                 goto free_and_error;
1268         }
1269
1270         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1271                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1272                 (unsigned long long)qid.path, qid.version, iounit);
1273
1274         fid->mode = mode;
1275         fid->iounit = iounit;
1276
1277 free_and_error:
1278         p9_tag_remove(clnt, req);
1279 error:
1280         return err;
1281 }
1282 EXPORT_SYMBOL(p9_client_open);
1283
1284 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1285                 kgid_t gid, struct p9_qid *qid)
1286 {
1287         int err = 0;
1288         struct p9_client *clnt;
1289         struct p9_req_t *req;
1290         int iounit;
1291
1292         p9_debug(P9_DEBUG_9P,
1293                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1294                         ofid->fid, name, flags, mode,
1295                         from_kgid(&init_user_ns, gid));
1296         clnt = ofid->clnt;
1297
1298         if (ofid->mode != -1)
1299                 return -EINVAL;
1300
1301         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1302                         mode, gid);
1303         if (IS_ERR(req)) {
1304                 err = PTR_ERR(req);
1305                 goto error;
1306         }
1307
1308         err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
1309         if (err) {
1310                 trace_9p_protocol_dump(clnt, &req->rc);
1311                 goto free_and_error;
1312         }
1313
1314         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1315                         qid->type,
1316                         (unsigned long long)qid->path,
1317                         qid->version, iounit);
1318
1319         ofid->mode = mode;
1320         ofid->iounit = iounit;
1321
1322 free_and_error:
1323         p9_tag_remove(clnt, req);
1324 error:
1325         return err;
1326 }
1327 EXPORT_SYMBOL(p9_client_create_dotl);
1328
1329 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1330                      char *extension)
1331 {
1332         int err;
1333         struct p9_client *clnt;
1334         struct p9_req_t *req;
1335         struct p9_qid qid;
1336         int iounit;
1337
1338         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1339                                                 fid->fid, name, perm, mode);
1340         err = 0;
1341         clnt = fid->clnt;
1342
1343         if (fid->mode != -1)
1344                 return -EINVAL;
1345
1346         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1347                                 mode, extension);
1348         if (IS_ERR(req)) {
1349                 err = PTR_ERR(req);
1350                 goto error;
1351         }
1352
1353         err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1354         if (err) {
1355                 trace_9p_protocol_dump(clnt, &req->rc);
1356                 goto free_and_error;
1357         }
1358
1359         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1360                                 qid.type,
1361                                 (unsigned long long)qid.path,
1362                                 qid.version, iounit);
1363
1364         fid->mode = mode;
1365         fid->iounit = iounit;
1366
1367 free_and_error:
1368         p9_tag_remove(clnt, req);
1369 error:
1370         return err;
1371 }
1372 EXPORT_SYMBOL(p9_client_fcreate);
1373
1374 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1375                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1376 {
1377         int err = 0;
1378         struct p9_client *clnt;
1379         struct p9_req_t *req;
1380
1381         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1382                         dfid->fid, name, symtgt);
1383         clnt = dfid->clnt;
1384
1385         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1386                         gid);
1387         if (IS_ERR(req)) {
1388                 err = PTR_ERR(req);
1389                 goto error;
1390         }
1391
1392         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
1393         if (err) {
1394                 trace_9p_protocol_dump(clnt, &req->rc);
1395                 goto free_and_error;
1396         }
1397
1398         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1399                         qid->type, (unsigned long long)qid->path, qid->version);
1400
1401 free_and_error:
1402         p9_tag_remove(clnt, req);
1403 error:
1404         return err;
1405 }
1406 EXPORT_SYMBOL(p9_client_symlink);
1407
1408 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1409 {
1410         struct p9_client *clnt;
1411         struct p9_req_t *req;
1412
1413         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1414                         dfid->fid, oldfid->fid, newname);
1415         clnt = dfid->clnt;
1416         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1417                         newname);
1418         if (IS_ERR(req))
1419                 return PTR_ERR(req);
1420
1421         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1422         p9_tag_remove(clnt, req);
1423         return 0;
1424 }
1425 EXPORT_SYMBOL(p9_client_link);
1426
1427 int p9_client_fsync(struct p9_fid *fid, int datasync)
1428 {
1429         int err;
1430         struct p9_client *clnt;
1431         struct p9_req_t *req;
1432
1433         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1434                         fid->fid, datasync);
1435         err = 0;
1436         clnt = fid->clnt;
1437
1438         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1439         if (IS_ERR(req)) {
1440                 err = PTR_ERR(req);
1441                 goto error;
1442         }
1443
1444         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1445
1446         p9_tag_remove(clnt, req);
1447
1448 error:
1449         return err;
1450 }
1451 EXPORT_SYMBOL(p9_client_fsync);
1452
1453 int p9_client_clunk(struct p9_fid *fid)
1454 {
1455         int err;
1456         struct p9_client *clnt;
1457         struct p9_req_t *req;
1458         int retries = 0;
1459
1460         if (!fid) {
1461                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1462                         __func__, task_pid_nr(current));
1463                 dump_stack();
1464                 return 0;
1465         }
1466
1467 again:
1468         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1469                                                                 retries);
1470         err = 0;
1471         clnt = fid->clnt;
1472
1473         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1474         if (IS_ERR(req)) {
1475                 err = PTR_ERR(req);
1476                 goto error;
1477         }
1478
1479         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1480
1481         p9_tag_remove(clnt, req);
1482 error:
1483         /*
1484          * Fid is not valid even after a failed clunk
1485          * If interrupted, retry once then give up and
1486          * leak fid until umount.
1487          */
1488         if (err == -ERESTARTSYS) {
1489                 if (retries++ == 0)
1490                         goto again;
1491         } else
1492                 p9_fid_destroy(fid);
1493         return err;
1494 }
1495 EXPORT_SYMBOL(p9_client_clunk);
1496
1497 int p9_client_remove(struct p9_fid *fid)
1498 {
1499         int err;
1500         struct p9_client *clnt;
1501         struct p9_req_t *req;
1502
1503         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1504         err = 0;
1505         clnt = fid->clnt;
1506
1507         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1508         if (IS_ERR(req)) {
1509                 err = PTR_ERR(req);
1510                 goto error;
1511         }
1512
1513         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1514
1515         p9_tag_remove(clnt, req);
1516 error:
1517         if (err == -ERESTARTSYS)
1518                 p9_client_clunk(fid);
1519         else
1520                 p9_fid_destroy(fid);
1521         return err;
1522 }
1523 EXPORT_SYMBOL(p9_client_remove);
1524
1525 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1526 {
1527         int err = 0;
1528         struct p9_req_t *req;
1529         struct p9_client *clnt;
1530
1531         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1532                    dfid->fid, name, flags);
1533
1534         clnt = dfid->clnt;
1535         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1536         if (IS_ERR(req)) {
1537                 err = PTR_ERR(req);
1538                 goto error;
1539         }
1540         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1541
1542         p9_tag_remove(clnt, req);
1543 error:
1544         return err;
1545 }
1546 EXPORT_SYMBOL(p9_client_unlinkat);
1547
1548 int
1549 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1550 {
1551         struct p9_client *clnt = fid->clnt;
1552         struct p9_req_t *req;
1553         int total = 0;
1554         *err = 0;
1555
1556         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1557                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1558
1559         while (iov_iter_count(to)) {
1560                 int count = iov_iter_count(to);
1561                 int rsize, non_zc = 0;
1562                 char *dataptr;
1563
1564                 rsize = fid->iounit;
1565                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1566                         rsize = clnt->msize - P9_IOHDRSZ;
1567
1568                 if (count < rsize)
1569                         rsize = count;
1570
1571                 /* Don't bother zerocopy for small IO (< 1024) */
1572                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1573                         /*
1574                          * response header len is 11
1575                          * PDU Header(7) + IO Size (4)
1576                          */
1577                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1578                                                0, 11, "dqd", fid->fid,
1579                                                offset, rsize);
1580                 } else {
1581                         non_zc = 1;
1582                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1583                                             rsize);
1584                 }
1585                 if (IS_ERR(req)) {
1586                         *err = PTR_ERR(req);
1587                         break;
1588                 }
1589
1590                 *err = p9pdu_readf(&req->rc, clnt->proto_version,
1591                                    "D", &count, &dataptr);
1592                 if (*err) {
1593                         trace_9p_protocol_dump(clnt, &req->rc);
1594                         p9_tag_remove(clnt, req);
1595                         break;
1596                 }
1597                 if (rsize < count) {
1598                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1599                         count = rsize;
1600                 }
1601
1602                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1603                 if (!count) {
1604                         p9_tag_remove(clnt, req);
1605                         break;
1606                 }
1607
1608                 if (non_zc) {
1609                         int n = copy_to_iter(dataptr, count, to);
1610                         total += n;
1611                         offset += n;
1612                         if (n != count) {
1613                                 *err = -EFAULT;
1614                                 p9_tag_remove(clnt, req);
1615                                 break;
1616                         }
1617                 } else {
1618                         iov_iter_advance(to, count);
1619                         total += count;
1620                         offset += count;
1621                 }
1622                 p9_tag_remove(clnt, req);
1623         }
1624         return total;
1625 }
1626 EXPORT_SYMBOL(p9_client_read);
1627
1628 int
1629 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1630 {
1631         struct p9_client *clnt = fid->clnt;
1632         struct p9_req_t *req;
1633         int total = 0;
1634         *err = 0;
1635
1636         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1637                                 fid->fid, (unsigned long long) offset,
1638                                 iov_iter_count(from));
1639
1640         while (iov_iter_count(from)) {
1641                 int count = iov_iter_count(from);
1642                 int rsize = fid->iounit;
1643                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1644                         rsize = clnt->msize - P9_IOHDRSZ;
1645
1646                 if (count < rsize)
1647                         rsize = count;
1648
1649                 /* Don't bother zerocopy for small IO (< 1024) */
1650                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1651                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1652                                                rsize, P9_ZC_HDR_SZ, "dqd",
1653                                                fid->fid, offset, rsize);
1654                 } else {
1655                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1656                                                     offset, rsize, from);
1657                 }
1658                 if (IS_ERR(req)) {
1659                         *err = PTR_ERR(req);
1660                         break;
1661                 }
1662
1663                 *err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count);
1664                 if (*err) {
1665                         trace_9p_protocol_dump(clnt, &req->rc);
1666                         p9_tag_remove(clnt, req);
1667                         break;
1668                 }
1669                 if (rsize < count) {
1670                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1671                         count = rsize;
1672                 }
1673
1674                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1675
1676                 p9_tag_remove(clnt, req);
1677                 iov_iter_advance(from, count);
1678                 total += count;
1679                 offset += count;
1680         }
1681         return total;
1682 }
1683 EXPORT_SYMBOL(p9_client_write);
1684
1685 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1686 {
1687         int err;
1688         struct p9_client *clnt;
1689         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1690         struct p9_req_t *req;
1691         u16 ignored;
1692
1693         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1694
1695         if (!ret)
1696                 return ERR_PTR(-ENOMEM);
1697
1698         err = 0;
1699         clnt = fid->clnt;
1700
1701         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1702         if (IS_ERR(req)) {
1703                 err = PTR_ERR(req);
1704                 goto error;
1705         }
1706
1707         err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
1708         if (err) {
1709                 trace_9p_protocol_dump(clnt, &req->rc);
1710                 p9_tag_remove(clnt, req);
1711                 goto error;
1712         }
1713
1714         p9_debug(P9_DEBUG_9P,
1715                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1716                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1717                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1718                 "<<<    uid=%d gid=%d n_muid=%d\n",
1719                 ret->size, ret->type, ret->dev, ret->qid.type,
1720                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1721                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1722                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1723                 from_kuid(&init_user_ns, ret->n_uid),
1724                 from_kgid(&init_user_ns, ret->n_gid),
1725                 from_kuid(&init_user_ns, ret->n_muid));
1726
1727         p9_tag_remove(clnt, req);
1728         return ret;
1729
1730 error:
1731         kfree(ret);
1732         return ERR_PTR(err);
1733 }
1734 EXPORT_SYMBOL(p9_client_stat);
1735
1736 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1737                                                         u64 request_mask)
1738 {
1739         int err;
1740         struct p9_client *clnt;
1741         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1742                                                                 GFP_KERNEL);
1743         struct p9_req_t *req;
1744
1745         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1746                                                         fid->fid, request_mask);
1747
1748         if (!ret)
1749                 return ERR_PTR(-ENOMEM);
1750
1751         err = 0;
1752         clnt = fid->clnt;
1753
1754         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1755         if (IS_ERR(req)) {
1756                 err = PTR_ERR(req);
1757                 goto error;
1758         }
1759
1760         err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
1761         if (err) {
1762                 trace_9p_protocol_dump(clnt, &req->rc);
1763                 p9_tag_remove(clnt, req);
1764                 goto error;
1765         }
1766
1767         p9_debug(P9_DEBUG_9P,
1768                 "<<< RGETATTR st_result_mask=%lld\n"
1769                 "<<< qid=%x.%llx.%x\n"
1770                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1771                 "<<< st_uid=%d st_gid=%d\n"
1772                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1773                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1774                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1775                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1776                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1777                 "<<< st_gen=%lld st_data_version=%lld\n",
1778                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1779                 ret->qid.version, ret->st_mode, ret->st_nlink,
1780                 from_kuid(&init_user_ns, ret->st_uid),
1781                 from_kgid(&init_user_ns, ret->st_gid),
1782                 ret->st_rdev, ret->st_size, ret->st_blksize,
1783                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1784                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1785                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1786                 ret->st_gen, ret->st_data_version);
1787
1788         p9_tag_remove(clnt, req);
1789         return ret;
1790
1791 error:
1792         kfree(ret);
1793         return ERR_PTR(err);
1794 }
1795 EXPORT_SYMBOL(p9_client_getattr_dotl);
1796
1797 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1798 {
1799         int ret;
1800
1801         /* NOTE: size shouldn't include its own length */
1802         /* size[2] type[2] dev[4] qid[13] */
1803         /* mode[4] atime[4] mtime[4] length[8]*/
1804         /* name[s] uid[s] gid[s] muid[s] */
1805         ret = 2+4+13+4+4+4+8+2+2+2+2;
1806
1807         if (wst->name)
1808                 ret += strlen(wst->name);
1809         if (wst->uid)
1810                 ret += strlen(wst->uid);
1811         if (wst->gid)
1812                 ret += strlen(wst->gid);
1813         if (wst->muid)
1814                 ret += strlen(wst->muid);
1815
1816         if ((proto_version == p9_proto_2000u) ||
1817                 (proto_version == p9_proto_2000L)) {
1818                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1819                 if (wst->extension)
1820                         ret += strlen(wst->extension);
1821         }
1822
1823         return ret;
1824 }
1825
1826 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1827 {
1828         int err;
1829         struct p9_req_t *req;
1830         struct p9_client *clnt;
1831
1832         err = 0;
1833         clnt = fid->clnt;
1834         wst->size = p9_client_statsize(wst, clnt->proto_version);
1835         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1836         p9_debug(P9_DEBUG_9P,
1837                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1838                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1839                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1840                 "     uid=%d gid=%d n_muid=%d\n",
1841                 wst->size, wst->type, wst->dev, wst->qid.type,
1842                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1843                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1844                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1845                 from_kuid(&init_user_ns, wst->n_uid),
1846                 from_kgid(&init_user_ns, wst->n_gid),
1847                 from_kuid(&init_user_ns, wst->n_muid));
1848
1849         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1850         if (IS_ERR(req)) {
1851                 err = PTR_ERR(req);
1852                 goto error;
1853         }
1854
1855         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1856
1857         p9_tag_remove(clnt, req);
1858 error:
1859         return err;
1860 }
1861 EXPORT_SYMBOL(p9_client_wstat);
1862
1863 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1864 {
1865         int err;
1866         struct p9_req_t *req;
1867         struct p9_client *clnt;
1868
1869         err = 0;
1870         clnt = fid->clnt;
1871         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1872         p9_debug(P9_DEBUG_9P,
1873                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1874                 "    atime_sec=%lld atime_nsec=%lld\n"
1875                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1876                 p9attr->valid, p9attr->mode,
1877                 from_kuid(&init_user_ns, p9attr->uid),
1878                 from_kgid(&init_user_ns, p9attr->gid),
1879                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1880                 p9attr->mtime_sec, p9attr->mtime_nsec);
1881
1882         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1883
1884         if (IS_ERR(req)) {
1885                 err = PTR_ERR(req);
1886                 goto error;
1887         }
1888         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1889         p9_tag_remove(clnt, req);
1890 error:
1891         return err;
1892 }
1893 EXPORT_SYMBOL(p9_client_setattr);
1894
1895 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1896 {
1897         int err;
1898         struct p9_req_t *req;
1899         struct p9_client *clnt;
1900
1901         err = 0;
1902         clnt = fid->clnt;
1903
1904         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1905
1906         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1907         if (IS_ERR(req)) {
1908                 err = PTR_ERR(req);
1909                 goto error;
1910         }
1911
1912         err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1913                           &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1914                           &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1915         if (err) {
1916                 trace_9p_protocol_dump(clnt, &req->rc);
1917                 p9_tag_remove(clnt, req);
1918                 goto error;
1919         }
1920
1921         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1922                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1923                 "fsid %llu namelen %ld\n",
1924                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1925                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1926                 sb->fsid, (long int)sb->namelen);
1927
1928         p9_tag_remove(clnt, req);
1929 error:
1930         return err;
1931 }
1932 EXPORT_SYMBOL(p9_client_statfs);
1933
1934 int p9_client_rename(struct p9_fid *fid,
1935                      struct p9_fid *newdirfid, const char *name)
1936 {
1937         int err;
1938         struct p9_req_t *req;
1939         struct p9_client *clnt;
1940
1941         err = 0;
1942         clnt = fid->clnt;
1943
1944         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1945                         fid->fid, newdirfid->fid, name);
1946
1947         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1948                         newdirfid->fid, name);
1949         if (IS_ERR(req)) {
1950                 err = PTR_ERR(req);
1951                 goto error;
1952         }
1953
1954         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1955
1956         p9_tag_remove(clnt, req);
1957 error:
1958         return err;
1959 }
1960 EXPORT_SYMBOL(p9_client_rename);
1961
1962 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1963                        struct p9_fid *newdirfid, const char *new_name)
1964 {
1965         int err;
1966         struct p9_req_t *req;
1967         struct p9_client *clnt;
1968
1969         err = 0;
1970         clnt = olddirfid->clnt;
1971
1972         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1973                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1974                    newdirfid->fid, new_name);
1975
1976         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1977                             old_name, newdirfid->fid, new_name);
1978         if (IS_ERR(req)) {
1979                 err = PTR_ERR(req);
1980                 goto error;
1981         }
1982
1983         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1984                    newdirfid->fid, new_name);
1985
1986         p9_tag_remove(clnt, req);
1987 error:
1988         return err;
1989 }
1990 EXPORT_SYMBOL(p9_client_renameat);
1991
1992 /*
1993  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1994  */
1995 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1996                                 const char *attr_name, u64 *attr_size)
1997 {
1998         int err;
1999         struct p9_req_t *req;
2000         struct p9_client *clnt;
2001         struct p9_fid *attr_fid;
2002
2003         err = 0;
2004         clnt = file_fid->clnt;
2005         attr_fid = p9_fid_create(clnt);
2006         if (!attr_fid) {
2007                 err = -ENOMEM;
2008                 goto error;
2009         }
2010         p9_debug(P9_DEBUG_9P,
2011                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2012                 file_fid->fid, attr_fid->fid, attr_name);
2013
2014         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2015                         file_fid->fid, attr_fid->fid, attr_name);
2016         if (IS_ERR(req)) {
2017                 err = PTR_ERR(req);
2018                 goto error;
2019         }
2020         err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
2021         if (err) {
2022                 trace_9p_protocol_dump(clnt, &req->rc);
2023                 p9_tag_remove(clnt, req);
2024                 goto clunk_fid;
2025         }
2026         p9_tag_remove(clnt, req);
2027         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2028                 attr_fid->fid, *attr_size);
2029         return attr_fid;
2030 clunk_fid:
2031         p9_client_clunk(attr_fid);
2032         attr_fid = NULL;
2033 error:
2034         if (attr_fid && (attr_fid != file_fid))
2035                 p9_fid_destroy(attr_fid);
2036
2037         return ERR_PTR(err);
2038 }
2039 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2040
2041 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2042                         u64 attr_size, int flags)
2043 {
2044         int err;
2045         struct p9_req_t *req;
2046         struct p9_client *clnt;
2047
2048         p9_debug(P9_DEBUG_9P,
2049                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2050                 fid->fid, name, (long long)attr_size, flags);
2051         err = 0;
2052         clnt = fid->clnt;
2053         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2054                         fid->fid, name, attr_size, flags);
2055         if (IS_ERR(req)) {
2056                 err = PTR_ERR(req);
2057                 goto error;
2058         }
2059         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2060         p9_tag_remove(clnt, req);
2061 error:
2062         return err;
2063 }
2064 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2065
2066 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2067 {
2068         int err, rsize, non_zc = 0;
2069         struct p9_client *clnt;
2070         struct p9_req_t *req;
2071         char *dataptr;
2072         struct kvec kv = {.iov_base = data, .iov_len = count};
2073         struct iov_iter to;
2074
2075         iov_iter_kvec(&to, READ, &kv, 1, count);
2076
2077         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2078                                 fid->fid, (unsigned long long) offset, count);
2079
2080         err = 0;
2081         clnt = fid->clnt;
2082
2083         rsize = fid->iounit;
2084         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2085                 rsize = clnt->msize - P9_READDIRHDRSZ;
2086
2087         if (count < rsize)
2088                 rsize = count;
2089
2090         /* Don't bother zerocopy for small IO (< 1024) */
2091         if (clnt->trans_mod->zc_request && rsize > 1024) {
2092                 /*
2093                  * response header len is 11
2094                  * PDU Header(7) + IO Size (4)
2095                  */
2096                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2097                                        11, "dqd", fid->fid, offset, rsize);
2098         } else {
2099                 non_zc = 1;
2100                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2101                                     offset, rsize);
2102         }
2103         if (IS_ERR(req)) {
2104                 err = PTR_ERR(req);
2105                 goto error;
2106         }
2107
2108         err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
2109         if (err) {
2110                 trace_9p_protocol_dump(clnt, &req->rc);
2111                 goto free_and_error;
2112         }
2113         if (rsize < count) {
2114                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2115                 count = rsize;
2116         }
2117
2118         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2119
2120         if (non_zc)
2121                 memmove(data, dataptr, count);
2122
2123         p9_tag_remove(clnt, req);
2124         return count;
2125
2126 free_and_error:
2127         p9_tag_remove(clnt, req);
2128 error:
2129         return err;
2130 }
2131 EXPORT_SYMBOL(p9_client_readdir);
2132
2133 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2134                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2135 {
2136         int err;
2137         struct p9_client *clnt;
2138         struct p9_req_t *req;
2139
2140         err = 0;
2141         clnt = fid->clnt;
2142         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2143                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2144         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2145                 MAJOR(rdev), MINOR(rdev), gid);
2146         if (IS_ERR(req))
2147                 return PTR_ERR(req);
2148
2149         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2150         if (err) {
2151                 trace_9p_protocol_dump(clnt, &req->rc);
2152                 goto error;
2153         }
2154         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2155                                 (unsigned long long)qid->path, qid->version);
2156
2157 error:
2158         p9_tag_remove(clnt, req);
2159         return err;
2160
2161 }
2162 EXPORT_SYMBOL(p9_client_mknod_dotl);
2163
2164 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2165                                 kgid_t gid, struct p9_qid *qid)
2166 {
2167         int err;
2168         struct p9_client *clnt;
2169         struct p9_req_t *req;
2170
2171         err = 0;
2172         clnt = fid->clnt;
2173         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2174                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2175         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2176                 gid);
2177         if (IS_ERR(req))
2178                 return PTR_ERR(req);
2179
2180         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2181         if (err) {
2182                 trace_9p_protocol_dump(clnt, &req->rc);
2183                 goto error;
2184         }
2185         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2186                                 (unsigned long long)qid->path, qid->version);
2187
2188 error:
2189         p9_tag_remove(clnt, req);
2190         return err;
2191
2192 }
2193 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2194
2195 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2196 {
2197         int err;
2198         struct p9_client *clnt;
2199         struct p9_req_t *req;
2200
2201         err = 0;
2202         clnt = fid->clnt;
2203         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2204                         "start %lld length %lld proc_id %d client_id %s\n",
2205                         fid->fid, flock->type, flock->flags, flock->start,
2206                         flock->length, flock->proc_id, flock->client_id);
2207
2208         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2209                                 flock->flags, flock->start, flock->length,
2210                                         flock->proc_id, flock->client_id);
2211
2212         if (IS_ERR(req))
2213                 return PTR_ERR(req);
2214
2215         err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
2216         if (err) {
2217                 trace_9p_protocol_dump(clnt, &req->rc);
2218                 goto error;
2219         }
2220         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2221 error:
2222         p9_tag_remove(clnt, req);
2223         return err;
2224
2225 }
2226 EXPORT_SYMBOL(p9_client_lock_dotl);
2227
2228 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2229 {
2230         int err;
2231         struct p9_client *clnt;
2232         struct p9_req_t *req;
2233
2234         err = 0;
2235         clnt = fid->clnt;
2236         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2237                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2238                 glock->start, glock->length, glock->proc_id, glock->client_id);
2239
2240         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2241                 glock->start, glock->length, glock->proc_id, glock->client_id);
2242
2243         if (IS_ERR(req))
2244                 return PTR_ERR(req);
2245
2246         err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type,
2247                           &glock->start, &glock->length, &glock->proc_id,
2248                           &glock->client_id);
2249         if (err) {
2250                 trace_9p_protocol_dump(clnt, &req->rc);
2251                 goto error;
2252         }
2253         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2254                 "proc_id %d client_id %s\n", glock->type, glock->start,
2255                 glock->length, glock->proc_id, glock->client_id);
2256 error:
2257         p9_tag_remove(clnt, req);
2258         return err;
2259 }
2260 EXPORT_SYMBOL(p9_client_getlock_dotl);
2261
2262 int p9_client_readlink(struct p9_fid *fid, char **target)
2263 {
2264         int err;
2265         struct p9_client *clnt;
2266         struct p9_req_t *req;
2267
2268         err = 0;
2269         clnt = fid->clnt;
2270         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2271
2272         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2273         if (IS_ERR(req))
2274                 return PTR_ERR(req);
2275
2276         err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
2277         if (err) {
2278                 trace_9p_protocol_dump(clnt, &req->rc);
2279                 goto error;
2280         }
2281         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2282 error:
2283         p9_tag_remove(clnt, req);
2284         return err;
2285 }
2286 EXPORT_SYMBOL(p9_client_readlink);
2287
2288 int __init p9_client_init(void)
2289 {
2290         p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU);
2291         return p9_req_cache ? 0 : -ENOMEM;
2292 }
2293
2294 void __exit p9_client_exit(void)
2295 {
2296         kmem_cache_destroy(p9_req_cache);
2297 }