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->t_err = 0;
 285         req->status = REQ_STATUS_ALLOC;
 286         init_waitqueue_head(&req->wq);
 287         INIT_LIST_HEAD(&req->req_list);
 288
 289         idr_preload(GFP_NOFS);
 290         spin_lock_irq(&c->lock);
 291         if (type == P9_TVERSION)
 292                 tag = idr_alloc(&c->reqs, req, P9_NOTAG, P9_NOTAG + 1,
 293                                 GFP_NOWAIT);
 294         else
 295                 tag = idr_alloc(&c->reqs, req, 0, P9_NOTAG, GFP_NOWAIT);
 296         req->tc.tag = tag;
 297         spin_unlock_irq(&c->lock);
 298         idr_preload_end();
 299         if (tag < 0)
 300                 goto free;
 301
 302         /* Init ref to two because in the general case there is one ref
 303          * that is put asynchronously by a writer thread, one ref
 304          * temporarily given by p9_tag_lookup and put by p9_client_cb
 305          * in the recv thread, and one ref put by p9_tag_remove in the
 306          * main thread. The only exception is virtio that does not use
 307          * p9_tag_lookup but does not have a writer thread either
 308          * (the write happens synchronously in the request/zc_request
 309          * callback), so p9_client_cb eats the second ref there
 310          * as the pointer is duplicated directly by virtqueue_add_sgs()
 311          */
 312         refcount_set(&req->refcount.refcount, 2);
 313
 314         return req;
 315
 316 free:
 317         p9_fcall_fini(&req->tc);
 318         p9_fcall_fini(&req->rc);
 319 free_req:
 320         kmem_cache_free(p9_req_cache, req);
 321         return ERR_PTR(-ENOMEM);
 322 }
 323
 324 /**
 325  * p9_tag_lookup - Look up a request by tag.
 326  * @c: Client session.
 327  * @tag: Transaction ID.
 328  *
 329  * Context: Any context.
 330  * Return: A request, or %NULL if there is no request with that tag.
 331  */
 332 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 333 {
 334         struct p9_req_t *req;
 335
 336         rcu_read_lock();
 337 again:
 338         req = idr_find(&c->reqs, tag);
 339         if (req) {
 340                 /* We have to be careful with the req found under rcu_read_lock
 341                  * Thanks to SLAB_TYPESAFE_BY_RCU we can safely try to get the
 342                  * ref again without corrupting other data, then check again
 343                  * that the tag matches once we have the ref
 344                  */
 345                 if (!p9_req_try_get(req))
 346                         goto again;
 347                 if (req->tc.tag != tag) {
 348                         p9_req_put(req);
 349                         goto again;
 350                 }
 351         }
 352         rcu_read_unlock();
 353
 354         return req;
 355 }
 356 EXPORT_SYMBOL(p9_tag_lookup);
 357
 358 /**
 359  * p9_tag_remove - Remove a tag.
 360  * @c: Client session.
 361  * @r: Request of reference.
 362  *
 363  * Context: Any context.
 364  */
 365 static int p9_tag_remove(struct p9_client *c, struct p9_req_t *r)
 366 {
 367         unsigned long flags;
 368         u16 tag = r->tc.tag;
 369
 370         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 371         spin_lock_irqsave(&c->lock, flags);
 372         idr_remove(&c->reqs, tag);
 373         spin_unlock_irqrestore(&c->lock, flags);
 374         return p9_req_put(r);
 375 }
 376
 377 static void p9_req_free(struct kref *ref)
 378 {
 379         struct p9_req_t *r = container_of(ref, struct p9_req_t, refcount);
 380         p9_fcall_fini(&r->tc);
 381         p9_fcall_fini(&r->rc);
 382         kmem_cache_free(p9_req_cache, r);
 383 }
 384
 385 int p9_req_put(struct p9_req_t *r)
 386 {
 387         return kref_put(&r->refcount, p9_req_free);
 388 }
 389 EXPORT_SYMBOL(p9_req_put);
 390
 391 /**
 392  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 393  * @c:  v9fs client struct
 394  *
 395  * This frees resources associated with the tags structure
 396  *
 397  */
 398 static void p9_tag_cleanup(struct p9_client *c)
 399 {
 400         struct p9_req_t *req;
 401         int id;
 402
 403         rcu_read_lock();
 404         idr_for_each_entry(&c->reqs, req, id) {
 405                 pr_info("Tag %d still in use\n", id);
 406                 if (p9_tag_remove(c, req) == 0)
 407                         pr_warn("Packet with tag %d has still references",
 408                                 req->tc.tag);
 409         }
 410         rcu_read_unlock();
 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 status change is visible to another thread
 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         p9_req_put(req);
 433 }
 434 EXPORT_SYMBOL(p9_client_cb);
 435
 436 /**
 437  * p9_parse_header - parse header arguments out of a packet
 438  * @pdu: packet to parse
 439  * @size: size of packet
 440  * @type: type of request
 441  * @tag: tag of packet
 442  * @rewind: set if we need to rewind offset afterwards
 443  */
 444
 445 int
 446 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 447                                                                 int rewind)
 448 {
 449         int8_t r_type;
 450         int16_t r_tag;
 451         int32_t r_size;
 452         int offset = pdu->offset;
 453         int err;
 454
 455         pdu->offset = 0;
 456
 457         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 458         if (err)
 459                 goto rewind_and_exit;
 460
 461         if (type)
 462                 *type = r_type;
 463         if (tag)
 464                 *tag = r_tag;
 465         if (size)
 466                 *size = r_size;
 467
 468         if (pdu->size != r_size || r_size < 7) {
 469                 err = -EINVAL;
 470                 goto rewind_and_exit;
 471         }
 472
 473         pdu->id = r_type;
 474         pdu->tag = r_tag;
 475
 476         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 477                  pdu->size, pdu->id, pdu->tag);
 478
 479 rewind_and_exit:
 480         if (rewind)
 481                 pdu->offset = offset;
 482         return err;
 483 }
 484 EXPORT_SYMBOL(p9_parse_header);
 485
 486 /**
 487  * p9_check_errors - check 9p packet for error return and process it
 488  * @c: current client instance
 489  * @req: request to parse and check for error conditions
 490  *
 491  * returns error code if one is discovered, otherwise returns 0
 492  *
 493  * this will have to be more complicated if we have multiple
 494  * error packet types
 495  */
 496
 497 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 498 {
 499         int8_t type;
 500         int err;
 501         int ecode;
 502
 503         err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
 504         if (req->rc.size >= c->msize) {
 505                 p9_debug(P9_DEBUG_ERROR,
 506                          "requested packet size too big: %d\n",
 507                          req->rc.size);
 508                 return -EIO;
 509         }
 510         /*
 511          * dump the response from server
 512          * This should be after check errors which poplulate pdu_fcall.
 513          */
 514         trace_9p_protocol_dump(c, &req->rc);
 515         if (err) {
 516                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 517                 return err;
 518         }
 519         if (type != P9_RERROR && type != P9_RLERROR)
 520                 return 0;
 521
 522         if (!p9_is_proto_dotl(c)) {
 523                 char *ename;
 524                 err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
 525                                   &ename, &ecode);
 526                 if (err)
 527                         goto out_err;
 528
 529                 if (p9_is_proto_dotu(c) && ecode < 512)
 530                         err = -ecode;
 531
 532                 if (!err) {
 533                         err = p9_errstr2errno(ename, strlen(ename));
 534
 535                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 536                                  -ecode, ename);
 537                 }
 538                 kfree(ename);
 539         } else {
 540                 err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
 541                 err = -ecode;
 542
 543                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 544         }
 545
 546         return err;
 547
 548 out_err:
 549         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 550
 551         return err;
 552 }
 553
 554 /**
 555  * p9_check_zc_errors - check 9p packet for error return and process it
 556  * @c: current client instance
 557  * @req: request to parse and check for error conditions
 558  * @in_hdrlen: Size of response protocol buffer.
 559  *
 560  * returns error code if one is discovered, otherwise returns 0
 561  *
 562  * this will have to be more complicated if we have multiple
 563  * error packet types
 564  */
 565
 566 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 567                               struct iov_iter *uidata, int in_hdrlen)
 568 {
 569         int err;
 570         int ecode;
 571         int8_t type;
 572         char *ename = NULL;
 573
 574         err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
 575         /*
 576          * dump the response from server
 577          * This should be after parse_header which poplulate pdu_fcall.
 578          */
 579         trace_9p_protocol_dump(c, &req->rc);
 580         if (err) {
 581                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 582                 return err;
 583         }
 584
 585         if (type != P9_RERROR && type != P9_RLERROR)
 586                 return 0;
 587
 588         if (!p9_is_proto_dotl(c)) {
 589                 /* Error is reported in string format */
 590                 int len;
 591                 /* 7 = header size for RERROR; */
 592                 int inline_len = in_hdrlen - 7;
 593
 594                 len = req->rc.size - req->rc.offset;
 595                 if (len > (P9_ZC_HDR_SZ - 7)) {
 596                         err = -EFAULT;
 597                         goto out_err;
 598                 }
 599
 600                 ename = &req->rc.sdata[req->rc.offset];
 601                 if (len > inline_len) {
 602                         /* We have error in external buffer */
 603                         if (!copy_from_iter_full(ename + inline_len,
 604                                              len - inline_len, uidata)) {
 605                                 err = -EFAULT;
 606                                 goto out_err;
 607                         }
 608                 }
 609                 ename = NULL;
 610                 err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
 611                                   &ename, &ecode);
 612                 if (err)
 613                         goto out_err;
 614
 615                 if (p9_is_proto_dotu(c) && ecode < 512)
 616                         err = -ecode;
 617
 618                 if (!err) {
 619                         err = p9_errstr2errno(ename, strlen(ename));
 620
 621                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 622                                  -ecode, ename);
 623                 }
 624                 kfree(ename);
 625         } else {
 626                 err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
 627                 err = -ecode;
 628
 629                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 630         }
 631         return err;
 632
 633 out_err:
 634         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 635         return err;
 636 }
 637
 638 static struct p9_req_t *
 639 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 640
 641 /**
 642  * p9_client_flush - flush (cancel) a request
 643  * @c: client state
 644  * @oldreq: request to cancel
 645  *
 646  * This sents a flush for a particular request and links
 647  * the flush request to the original request.  The current
 648  * code only supports a single flush request although the protocol
 649  * allows for multiple flush requests to be sent for a single request.
 650  *
 651  */
 652
 653 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 654 {
 655         struct p9_req_t *req;
 656         int16_t oldtag;
 657         int err;
 658
 659         err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
 660         if (err)
 661                 return err;
 662
 663         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 664
 665         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 666         if (IS_ERR(req))
 667                 return PTR_ERR(req);
 668
 669         /*
 670          * if we haven't received a response for oldreq,
 671          * remove it from the list
 672          */
 673         if (oldreq->status == REQ_STATUS_SENT) {
 674                 if (c->trans_mod->cancelled)
 675                         c->trans_mod->cancelled(c, oldreq);
 676         }
 677
 678         p9_tag_remove(c, req);
 679         return 0;
 680 }
 681
 682 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 683                                               int8_t type, int req_size,
 684                                               const char *fmt, va_list ap)
 685 {
 686         int err;
 687         struct p9_req_t *req;
 688
 689         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 690
 691         /* we allow for any status other than disconnected */
 692         if (c->status == Disconnected)
 693                 return ERR_PTR(-EIO);
 694
 695         /* if status is begin_disconnected we allow only clunk request */
 696         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 697                 return ERR_PTR(-EIO);
 698
 699         req = p9_tag_alloc(c, type, req_size);
 700         if (IS_ERR(req))
 701                 return req;
 702
 703         /* marshall the data */
 704         p9pdu_prepare(&req->tc, req->tc.tag, type);
 705         err = p9pdu_vwritef(&req->tc, c->proto_version, fmt, ap);
 706         if (err)
 707                 goto reterr;
 708         p9pdu_finalize(c, &req->tc);
 709         trace_9p_client_req(c, type, req->tc.tag);
 710         return req;
 711 reterr:
 712         p9_tag_remove(c, req);
 713         /* We have to put also the 2nd reference as it won't be used */
 714         p9_req_put(req);
 715         return ERR_PTR(err);
 716 }
 717
 718 /**
 719  * p9_client_rpc - issue a request and wait for a response
 720  * @c: client session
 721  * @type: type of request
 722  * @fmt: protocol format string (see protocol.c)
 723  *
 724  * Returns request structure (which client must free using p9_tag_remove)
 725  */
 726
 727 static struct p9_req_t *
 728 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 729 {
 730         va_list ap;
 731         int sigpending, err;
 732         unsigned long flags;
 733         struct p9_req_t *req;
 734
 735         va_start(ap, fmt);
 736         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 737         va_end(ap);
 738         if (IS_ERR(req))
 739                 return req;
 740
 741         if (signal_pending(current)) {
 742                 sigpending = 1;
 743                 clear_thread_flag(TIF_SIGPENDING);
 744         } else
 745                 sigpending = 0;
 746
 747         err = c->trans_mod->request(c, req);
 748         if (err < 0) {
 749                 /* write won't happen */
 750                 p9_req_put(req);
 751                 if (err != -ERESTARTSYS && err != -EFAULT)
 752                         c->status = Disconnected;
 753                 goto recalc_sigpending;
 754         }
 755 again:
 756         /* Wait for the response */
 757         err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
 758
 759         /*
 760          * Make sure our req is coherent with regard to updates in other
 761          * threads - echoes to wmb() in the callback
 762          */
 763         smp_rmb();
 764
 765         if ((err == -ERESTARTSYS) && (c->status == Connected)
 766                                   && (type == P9_TFLUSH)) {
 767                 sigpending = 1;
 768                 clear_thread_flag(TIF_SIGPENDING);
 769                 goto again;
 770         }
 771
 772         if (req->status == REQ_STATUS_ERROR) {
 773                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 774                 err = req->t_err;
 775         }
 776         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 777                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 778                 sigpending = 1;
 779                 clear_thread_flag(TIF_SIGPENDING);
 780
 781                 if (c->trans_mod->cancel(c, req))
 782                         p9_client_flush(c, req);
 783
 784                 /* if we received the response anyway, don't signal error */
 785                 if (req->status == REQ_STATUS_RCVD)
 786                         err = 0;
 787         }
 788 recalc_sigpending:
 789         if (sigpending) {
 790                 spin_lock_irqsave(&current->sighand->siglock, flags);
 791                 recalc_sigpending();
 792                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 793         }
 794         if (err < 0)
 795                 goto reterr;
 796
 797         err = p9_check_errors(c, req);
 798         trace_9p_client_res(c, type, req->rc.tag, err);
 799         if (!err)
 800                 return req;
 801 reterr:
 802         p9_tag_remove(c, req);
 803         return ERR_PTR(safe_errno(err));
 804 }
 805
 806 /**
 807  * p9_client_zc_rpc - issue a request and wait for a response
 808  * @c: client session
 809  * @type: type of request
 810  * @uidata: destination for zero copy read
 811  * @uodata: source for zero copy write
 812  * @inlen: read buffer size
 813  * @olen: write buffer size
 814  * @hdrlen: reader header size, This is the size of response protocol data
 815  * @fmt: protocol format string (see protocol.c)
 816  *
 817  * Returns request structure (which client must free using p9_tag_remove)
 818  */
 819 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 820                                          struct iov_iter *uidata,
 821                                          struct iov_iter *uodata,
 822                                          int inlen, int olen, int in_hdrlen,
 823                                          const char *fmt, ...)
 824 {
 825         va_list ap;
 826         int sigpending, err;
 827         unsigned long flags;
 828         struct p9_req_t *req;
 829
 830         va_start(ap, fmt);
 831         /*
 832          * We allocate a inline protocol data of only 4k bytes.
 833          * The actual content is passed in zero-copy fashion.
 834          */
 835         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 836         va_end(ap);
 837         if (IS_ERR(req))
 838                 return req;
 839
 840         if (signal_pending(current)) {
 841                 sigpending = 1;
 842                 clear_thread_flag(TIF_SIGPENDING);
 843         } else
 844                 sigpending = 0;
 845
 846         err = c->trans_mod->zc_request(c, req, uidata, uodata,
 847                                        inlen, olen, in_hdrlen);
 848         if (err < 0) {
 849                 if (err == -EIO)
 850                         c->status = Disconnected;
 851                 if (err != -ERESTARTSYS)
 852                         goto recalc_sigpending;
 853         }
 854         if (req->status == REQ_STATUS_ERROR) {
 855                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 856                 err = req->t_err;
 857         }
 858         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 859                 p9_debug(P9_DEBUG_MUX, "flushing\n");
 860                 sigpending = 1;
 861                 clear_thread_flag(TIF_SIGPENDING);
 862
 863                 if (c->trans_mod->cancel(c, req))
 864                         p9_client_flush(c, req);
 865
 866                 /* if we received the response anyway, don't signal error */
 867                 if (req->status == REQ_STATUS_RCVD)
 868                         err = 0;
 869         }
 870 recalc_sigpending:
 871         if (sigpending) {
 872                 spin_lock_irqsave(&current->sighand->siglock, flags);
 873                 recalc_sigpending();
 874                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 875         }
 876         if (err < 0)
 877                 goto reterr;
 878
 879         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 880         trace_9p_client_res(c, type, req->rc.tag, err);
 881         if (!err)
 882                 return req;
 883 reterr:
 884         p9_tag_remove(c, req);
 885         return ERR_PTR(safe_errno(err));
 886 }
 887
 888 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 889 {
 890         int ret;
 891         struct p9_fid *fid;
 892
 893         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 894         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 895         if (!fid)
 896                 return NULL;
 897
 898         memset(&fid->qid, 0, sizeof(struct p9_qid));
 899         fid->mode = -1;
 900         fid->uid = current_fsuid();
 901         fid->clnt = clnt;
 902         fid->rdir = NULL;
 903         fid->fid = 0;
 904
 905         idr_preload(GFP_KERNEL);
 906         spin_lock_irq(&clnt->lock);
 907         ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
 908                             GFP_NOWAIT);
 909         spin_unlock_irq(&clnt->lock);
 910         idr_preload_end();
 911
 912         if (!ret)
 913                 return fid;
 914
 915         kfree(fid);
 916         return NULL;
 917 }
 918
 919 static void p9_fid_destroy(struct p9_fid *fid)
 920 {
 921         struct p9_client *clnt;
 922         unsigned long flags;
 923
 924         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 925         clnt = fid->clnt;
 926         spin_lock_irqsave(&clnt->lock, flags);
 927         idr_remove(&clnt->fids, fid->fid);
 928         spin_unlock_irqrestore(&clnt->lock, flags);
 929         kfree(fid->rdir);
 930         kfree(fid);
 931 }
 932
 933 static int p9_client_version(struct p9_client *c)
 934 {
 935         int err = 0;
 936         struct p9_req_t *req;
 937         char *version = NULL;
 938         int msize;
 939
 940         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 941                  c->msize, c->proto_version);
 942
 943         switch (c->proto_version) {
 944         case p9_proto_2000L:
 945                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 946                                         c->msize, "9P2000.L");
 947                 break;
 948         case p9_proto_2000u:
 949                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 950                                         c->msize, "9P2000.u");
 951                 break;
 952         case p9_proto_legacy:
 953                 req = p9_client_rpc(c, P9_TVERSION, "ds",
 954                                         c->msize, "9P2000");
 955                 break;
 956         default:
 957                 return -EINVAL;
 958         }
 959
 960         if (IS_ERR(req))
 961                 return PTR_ERR(req);
 962
 963         err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version);
 964         if (err) {
 965                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 966                 trace_9p_protocol_dump(c, &req->rc);
 967                 goto error;
 968         }
 969
 970         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 971         if (!strncmp(version, "9P2000.L", 8))
 972                 c->proto_version = p9_proto_2000L;
 973         else if (!strncmp(version, "9P2000.u", 8))
 974                 c->proto_version = p9_proto_2000u;
 975         else if (!strncmp(version, "9P2000", 6))
 976                 c->proto_version = p9_proto_legacy;
 977         else {
 978                 p9_debug(P9_DEBUG_ERROR,
 979                          "server returned an unknown version: %s\n", version);
 980                 err = -EREMOTEIO;
 981                 goto error;
 982         }
 983
 984         if (msize < 4096) {
 985                 p9_debug(P9_DEBUG_ERROR,
 986                          "server returned a msize < 4096: %d\n", msize);
 987                 err = -EREMOTEIO;
 988                 goto error;
 989         }
 990         if (msize < c->msize)
 991                 c->msize = msize;
 992
 993 error:
 994         kfree(version);
 995         p9_tag_remove(c, req);
 996
 997         return err;
 998 }
 999
1000 struct p9_client *p9_client_create(const char *dev_name, char *options)
1001 {
1002         int err;
1003         struct p9_client *clnt;
1004         char *client_id;
1005
1006         err = 0;
1007         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1008         if (!clnt)
1009                 return ERR_PTR(-ENOMEM);
1010
1011         clnt->trans_mod = NULL;
1012         clnt->trans = NULL;
1013         clnt->fcall_cache = NULL;
1014
1015         client_id = utsname()->nodename;
1016         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1017
1018         spin_lock_init(&clnt->lock);
1019         idr_init(&clnt->fids);
1020         idr_init(&clnt->reqs);
1021
1022         err = parse_opts(options, clnt);
1023         if (err < 0)
1024                 goto free_client;
1025
1026         if (!clnt->trans_mod)
1027                 clnt->trans_mod = v9fs_get_default_trans();
1028
1029         if (clnt->trans_mod == NULL) {
1030                 err = -EPROTONOSUPPORT;
1031                 p9_debug(P9_DEBUG_ERROR,
1032                          "No transport defined or default transport\n");
1033                 goto free_client;
1034         }
1035
1036         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1037                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1038
1039         err = clnt->trans_mod->create(clnt, dev_name, options);
1040         if (err)
1041                 goto put_trans;
1042
1043         if (clnt->msize > clnt->trans_mod->maxsize)
1044                 clnt->msize = clnt->trans_mod->maxsize;
1045
1046         if (clnt->msize < 4096) {
1047                 p9_debug(P9_DEBUG_ERROR,
1048                          "Please specify a msize of at least 4k\n");
1049                 err = -EINVAL;
1050                 goto close_trans;
1051         }
1052
1053         err = p9_client_version(clnt);
1054         if (err)
1055                 goto close_trans;
1056
1057         /* P9_HDRSZ + 4 is the smallest packet header we can have that is
1058          * followed by data accessed from userspace by read
1059          */
1060         clnt->fcall_cache =
1061                 kmem_cache_create_usercopy("9p-fcall-cache", clnt->msize,
1062                                            0, 0, P9_HDRSZ + 4,
1063                                            clnt->msize - (P9_HDRSZ + 4),
1064                                            NULL);
1065
1066         return clnt;
1067
1068 close_trans:
1069         clnt->trans_mod->close(clnt);
1070 put_trans:
1071         v9fs_put_trans(clnt->trans_mod);
1072 free_client:
1073         kfree(clnt);
1074         return ERR_PTR(err);
1075 }
1076 EXPORT_SYMBOL(p9_client_create);
1077
1078 void p9_client_destroy(struct p9_client *clnt)
1079 {
1080         struct p9_fid *fid;
1081         int id;
1082
1083         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1084
1085         if (clnt->trans_mod)
1086                 clnt->trans_mod->close(clnt);
1087
1088         v9fs_put_trans(clnt->trans_mod);
1089
1090         idr_for_each_entry(&clnt->fids, fid, id) {
1091                 pr_info("Found fid %d not clunked\n", fid->fid);
1092                 p9_fid_destroy(fid);
1093         }
1094
1095         p9_tag_cleanup(clnt);
1096
1097         kmem_cache_destroy(clnt->fcall_cache);
1098         kfree(clnt);
1099 }
1100 EXPORT_SYMBOL(p9_client_destroy);
1101
1102 void p9_client_disconnect(struct p9_client *clnt)
1103 {
1104         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1105         clnt->status = Disconnected;
1106 }
1107 EXPORT_SYMBOL(p9_client_disconnect);
1108
1109 void p9_client_begin_disconnect(struct p9_client *clnt)
1110 {
1111         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1112         clnt->status = BeginDisconnect;
1113 }
1114 EXPORT_SYMBOL(p9_client_begin_disconnect);
1115
1116 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1117         const char *uname, kuid_t n_uname, const char *aname)
1118 {
1119         int err = 0;
1120         struct p9_req_t *req;
1121         struct p9_fid *fid;
1122         struct p9_qid qid;
1123
1124
1125         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1126                  afid ? afid->fid : -1, uname, aname);
1127         fid = p9_fid_create(clnt);
1128         if (!fid) {
1129                 err = -ENOMEM;
1130                 goto error;
1131         }
1132         fid->uid = n_uname;
1133
1134         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1135                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1136         if (IS_ERR(req)) {
1137                 err = PTR_ERR(req);
1138                 goto error;
1139         }
1140
1141         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
1142         if (err) {
1143                 trace_9p_protocol_dump(clnt, &req->rc);
1144                 p9_tag_remove(clnt, req);
1145                 goto error;
1146         }
1147
1148         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1149                  qid.type, (unsigned long long)qid.path, qid.version);
1150
1151         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1152
1153         p9_tag_remove(clnt, req);
1154         return fid;
1155
1156 error:
1157         if (fid)
1158                 p9_fid_destroy(fid);
1159         return ERR_PTR(err);
1160 }
1161 EXPORT_SYMBOL(p9_client_attach);
1162
1163 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1164                 const unsigned char * const *wnames, int clone)
1165 {
1166         int err;
1167         struct p9_client *clnt;
1168         struct p9_fid *fid;
1169         struct p9_qid *wqids;
1170         struct p9_req_t *req;
1171         uint16_t nwqids, count;
1172
1173         err = 0;
1174         wqids = NULL;
1175         clnt = oldfid->clnt;
1176         if (clone) {
1177                 fid = p9_fid_create(clnt);
1178                 if (!fid) {
1179                         err = -ENOMEM;
1180                         goto error;
1181                 }
1182
1183                 fid->uid = oldfid->uid;
1184         } else
1185                 fid = oldfid;
1186
1187
1188         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1189                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1190
1191         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1192                                                                 nwname, wnames);
1193         if (IS_ERR(req)) {
1194                 err = PTR_ERR(req);
1195                 goto error;
1196         }
1197
1198         err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1199         if (err) {
1200                 trace_9p_protocol_dump(clnt, &req->rc);
1201                 p9_tag_remove(clnt, req);
1202                 goto clunk_fid;
1203         }
1204         p9_tag_remove(clnt, req);
1205
1206         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1207
1208         if (nwqids != nwname) {
1209                 err = -ENOENT;
1210                 goto clunk_fid;
1211         }
1212
1213         for (count = 0; count < nwqids; count++)
1214                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1215                         count, wqids[count].type,
1216                         (unsigned long long)wqids[count].path,
1217                         wqids[count].version);
1218
1219         if (nwname)
1220                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1221         else
1222                 fid->qid = oldfid->qid;
1223
1224         kfree(wqids);
1225         return fid;
1226
1227 clunk_fid:
1228         kfree(wqids);
1229         p9_client_clunk(fid);
1230         fid = NULL;
1231
1232 error:
1233         if (fid && (fid != oldfid))
1234                 p9_fid_destroy(fid);
1235
1236         return ERR_PTR(err);
1237 }
1238 EXPORT_SYMBOL(p9_client_walk);
1239
1240 int p9_client_open(struct p9_fid *fid, int mode)
1241 {
1242         int err;
1243         struct p9_client *clnt;
1244         struct p9_req_t *req;
1245         struct p9_qid qid;
1246         int iounit;
1247
1248         clnt = fid->clnt;
1249         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1250                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1251         err = 0;
1252
1253         if (fid->mode != -1)
1254                 return -EINVAL;
1255
1256         if (p9_is_proto_dotl(clnt))
1257                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1258         else
1259                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1260         if (IS_ERR(req)) {
1261                 err = PTR_ERR(req);
1262                 goto error;
1263         }
1264
1265         err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1266         if (err) {
1267                 trace_9p_protocol_dump(clnt, &req->rc);
1268                 goto free_and_error;
1269         }
1270
1271         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1272                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1273                 (unsigned long long)qid.path, qid.version, iounit);
1274
1275         fid->mode = mode;
1276         fid->iounit = iounit;
1277
1278 free_and_error:
1279         p9_tag_remove(clnt, req);
1280 error:
1281         return err;
1282 }
1283 EXPORT_SYMBOL(p9_client_open);
1284
1285 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1286                 kgid_t gid, struct p9_qid *qid)
1287 {
1288         int err = 0;
1289         struct p9_client *clnt;
1290         struct p9_req_t *req;
1291         int iounit;
1292
1293         p9_debug(P9_DEBUG_9P,
1294                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1295                         ofid->fid, name, flags, mode,
1296                         from_kgid(&init_user_ns, gid));
1297         clnt = ofid->clnt;
1298
1299         if (ofid->mode != -1)
1300                 return -EINVAL;
1301
1302         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1303                         mode, gid);
1304         if (IS_ERR(req)) {
1305                 err = PTR_ERR(req);
1306                 goto error;
1307         }
1308
1309         err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
1310         if (err) {
1311                 trace_9p_protocol_dump(clnt, &req->rc);
1312                 goto free_and_error;
1313         }
1314
1315         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1316                         qid->type,
1317                         (unsigned long long)qid->path,
1318                         qid->version, iounit);
1319
1320         ofid->mode = mode;
1321         ofid->iounit = iounit;
1322
1323 free_and_error:
1324         p9_tag_remove(clnt, req);
1325 error:
1326         return err;
1327 }
1328 EXPORT_SYMBOL(p9_client_create_dotl);
1329
1330 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1331                      char *extension)
1332 {
1333         int err;
1334         struct p9_client *clnt;
1335         struct p9_req_t *req;
1336         struct p9_qid qid;
1337         int iounit;
1338
1339         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1340                                                 fid->fid, name, perm, mode);
1341         err = 0;
1342         clnt = fid->clnt;
1343
1344         if (fid->mode != -1)
1345                 return -EINVAL;
1346
1347         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1348                                 mode, extension);
1349         if (IS_ERR(req)) {
1350                 err = PTR_ERR(req);
1351                 goto error;
1352         }
1353
1354         err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1355         if (err) {
1356                 trace_9p_protocol_dump(clnt, &req->rc);
1357                 goto free_and_error;
1358         }
1359
1360         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1361                                 qid.type,
1362                                 (unsigned long long)qid.path,
1363                                 qid.version, iounit);
1364
1365         fid->mode = mode;
1366         fid->iounit = iounit;
1367
1368 free_and_error:
1369         p9_tag_remove(clnt, req);
1370 error:
1371         return err;
1372 }
1373 EXPORT_SYMBOL(p9_client_fcreate);
1374
1375 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1376                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1377 {
1378         int err = 0;
1379         struct p9_client *clnt;
1380         struct p9_req_t *req;
1381
1382         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1383                         dfid->fid, name, symtgt);
1384         clnt = dfid->clnt;
1385
1386         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1387                         gid);
1388         if (IS_ERR(req)) {
1389                 err = PTR_ERR(req);
1390                 goto error;
1391         }
1392
1393         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
1394         if (err) {
1395                 trace_9p_protocol_dump(clnt, &req->rc);
1396                 goto free_and_error;
1397         }
1398
1399         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1400                         qid->type, (unsigned long long)qid->path, qid->version);
1401
1402 free_and_error:
1403         p9_tag_remove(clnt, req);
1404 error:
1405         return err;
1406 }
1407 EXPORT_SYMBOL(p9_client_symlink);
1408
1409 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1410 {
1411         struct p9_client *clnt;
1412         struct p9_req_t *req;
1413
1414         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1415                         dfid->fid, oldfid->fid, newname);
1416         clnt = dfid->clnt;
1417         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1418                         newname);
1419         if (IS_ERR(req))
1420                 return PTR_ERR(req);
1421
1422         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1423         p9_tag_remove(clnt, req);
1424         return 0;
1425 }
1426 EXPORT_SYMBOL(p9_client_link);
1427
1428 int p9_client_fsync(struct p9_fid *fid, int datasync)
1429 {
1430         int err;
1431         struct p9_client *clnt;
1432         struct p9_req_t *req;
1433
1434         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1435                         fid->fid, datasync);
1436         err = 0;
1437         clnt = fid->clnt;
1438
1439         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1440         if (IS_ERR(req)) {
1441                 err = PTR_ERR(req);
1442                 goto error;
1443         }
1444
1445         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1446
1447         p9_tag_remove(clnt, req);
1448
1449 error:
1450         return err;
1451 }
1452 EXPORT_SYMBOL(p9_client_fsync);
1453
1454 int p9_client_clunk(struct p9_fid *fid)
1455 {
1456         int err;
1457         struct p9_client *clnt;
1458         struct p9_req_t *req;
1459         int retries = 0;
1460
1461         if (!fid) {
1462                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1463                         __func__, task_pid_nr(current));
1464                 dump_stack();
1465                 return 0;
1466         }
1467
1468 again:
1469         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1470                                                                 retries);
1471         err = 0;
1472         clnt = fid->clnt;
1473
1474         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1475         if (IS_ERR(req)) {
1476                 err = PTR_ERR(req);
1477                 goto error;
1478         }
1479
1480         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1481
1482         p9_tag_remove(clnt, req);
1483 error:
1484         /*
1485          * Fid is not valid even after a failed clunk
1486          * If interrupted, retry once then give up and
1487          * leak fid until umount.
1488          */
1489         if (err == -ERESTARTSYS) {
1490                 if (retries++ == 0)
1491                         goto again;
1492         } else
1493                 p9_fid_destroy(fid);
1494         return err;
1495 }
1496 EXPORT_SYMBOL(p9_client_clunk);
1497
1498 int p9_client_remove(struct p9_fid *fid)
1499 {
1500         int err;
1501         struct p9_client *clnt;
1502         struct p9_req_t *req;
1503
1504         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1505         err = 0;
1506         clnt = fid->clnt;
1507
1508         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1509         if (IS_ERR(req)) {
1510                 err = PTR_ERR(req);
1511                 goto error;
1512         }
1513
1514         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1515
1516         p9_tag_remove(clnt, req);
1517 error:
1518         if (err == -ERESTARTSYS)
1519                 p9_client_clunk(fid);
1520         else
1521                 p9_fid_destroy(fid);
1522         return err;
1523 }
1524 EXPORT_SYMBOL(p9_client_remove);
1525
1526 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1527 {
1528         int err = 0;
1529         struct p9_req_t *req;
1530         struct p9_client *clnt;
1531
1532         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1533                    dfid->fid, name, flags);
1534
1535         clnt = dfid->clnt;
1536         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1537         if (IS_ERR(req)) {
1538                 err = PTR_ERR(req);
1539                 goto error;
1540         }
1541         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1542
1543         p9_tag_remove(clnt, req);
1544 error:
1545         return err;
1546 }
1547 EXPORT_SYMBOL(p9_client_unlinkat);
1548
1549 int
1550 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1551 {
1552         struct p9_client *clnt = fid->clnt;
1553         struct p9_req_t *req;
1554         int total = 0;
1555         *err = 0;
1556
1557         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1558                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1559
1560         while (iov_iter_count(to)) {
1561                 int count = iov_iter_count(to);
1562                 int rsize, non_zc = 0;
1563                 char *dataptr;
1564
1565                 rsize = fid->iounit;
1566                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1567                         rsize = clnt->msize - P9_IOHDRSZ;
1568
1569                 if (count < rsize)
1570                         rsize = count;
1571
1572                 /* Don't bother zerocopy for small IO (< 1024) */
1573                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1574                         /*
1575                          * response header len is 11
1576                          * PDU Header(7) + IO Size (4)
1577                          */
1578                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1579                                                0, 11, "dqd", fid->fid,
1580                                                offset, rsize);
1581                 } else {
1582                         non_zc = 1;
1583                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1584                                             rsize);
1585                 }
1586                 if (IS_ERR(req)) {
1587                         *err = PTR_ERR(req);
1588                         break;
1589                 }
1590
1591                 *err = p9pdu_readf(&req->rc, clnt->proto_version,
1592                                    "D", &count, &dataptr);
1593                 if (*err) {
1594                         trace_9p_protocol_dump(clnt, &req->rc);
1595                         p9_tag_remove(clnt, req);
1596                         break;
1597                 }
1598                 if (rsize < count) {
1599                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1600                         count = rsize;
1601                 }
1602
1603                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1604                 if (!count) {
1605                         p9_tag_remove(clnt, req);
1606                         break;
1607                 }
1608
1609                 if (non_zc) {
1610                         int n = copy_to_iter(dataptr, count, to);
1611                         total += n;
1612                         offset += n;
1613                         if (n != count) {
1614                                 *err = -EFAULT;
1615                                 p9_tag_remove(clnt, req);
1616                                 break;
1617                         }
1618                 } else {
1619                         iov_iter_advance(to, count);
1620                         total += count;
1621                         offset += count;
1622                 }
1623                 p9_tag_remove(clnt, req);
1624         }
1625         return total;
1626 }
1627 EXPORT_SYMBOL(p9_client_read);
1628
1629 int
1630 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1631 {
1632         struct p9_client *clnt = fid->clnt;
1633         struct p9_req_t *req;
1634         int total = 0;
1635         *err = 0;
1636
1637         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1638                                 fid->fid, (unsigned long long) offset,
1639                                 iov_iter_count(from));
1640
1641         while (iov_iter_count(from)) {
1642                 int count = iov_iter_count(from);
1643                 int rsize = fid->iounit;
1644                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1645                         rsize = clnt->msize - P9_IOHDRSZ;
1646
1647                 if (count < rsize)
1648                         rsize = count;
1649
1650                 /* Don't bother zerocopy for small IO (< 1024) */
1651                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1652                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1653                                                rsize, P9_ZC_HDR_SZ, "dqd",
1654                                                fid->fid, offset, rsize);
1655                 } else {
1656                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1657                                                     offset, rsize, from);
1658                 }
1659                 if (IS_ERR(req)) {
1660                         *err = PTR_ERR(req);
1661                         break;
1662                 }
1663
1664                 *err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count);
1665                 if (*err) {
1666                         trace_9p_protocol_dump(clnt, &req->rc);
1667                         p9_tag_remove(clnt, req);
1668                         break;
1669                 }
1670                 if (rsize < count) {
1671                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1672                         count = rsize;
1673                 }
1674
1675                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1676
1677                 p9_tag_remove(clnt, req);
1678                 iov_iter_advance(from, count);
1679                 total += count;
1680                 offset += count;
1681         }
1682         return total;
1683 }
1684 EXPORT_SYMBOL(p9_client_write);
1685
1686 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1687 {
1688         int err;
1689         struct p9_client *clnt;
1690         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1691         struct p9_req_t *req;
1692         u16 ignored;
1693
1694         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1695
1696         if (!ret)
1697                 return ERR_PTR(-ENOMEM);
1698
1699         err = 0;
1700         clnt = fid->clnt;
1701
1702         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1703         if (IS_ERR(req)) {
1704                 err = PTR_ERR(req);
1705                 goto error;
1706         }
1707
1708         err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
1709         if (err) {
1710                 trace_9p_protocol_dump(clnt, &req->rc);
1711                 p9_tag_remove(clnt, req);
1712                 goto error;
1713         }
1714
1715         p9_debug(P9_DEBUG_9P,
1716                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1717                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1718                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1719                 "<<<    uid=%d gid=%d n_muid=%d\n",
1720                 ret->size, ret->type, ret->dev, ret->qid.type,
1721                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1722                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1723                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1724                 from_kuid(&init_user_ns, ret->n_uid),
1725                 from_kgid(&init_user_ns, ret->n_gid),
1726                 from_kuid(&init_user_ns, ret->n_muid));
1727
1728         p9_tag_remove(clnt, req);
1729         return ret;
1730
1731 error:
1732         kfree(ret);
1733         return ERR_PTR(err);
1734 }
1735 EXPORT_SYMBOL(p9_client_stat);
1736
1737 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1738                                                         u64 request_mask)
1739 {
1740         int err;
1741         struct p9_client *clnt;
1742         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1743                                                                 GFP_KERNEL);
1744         struct p9_req_t *req;
1745
1746         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1747                                                         fid->fid, request_mask);
1748
1749         if (!ret)
1750                 return ERR_PTR(-ENOMEM);
1751
1752         err = 0;
1753         clnt = fid->clnt;
1754
1755         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1756         if (IS_ERR(req)) {
1757                 err = PTR_ERR(req);
1758                 goto error;
1759         }
1760
1761         err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
1762         if (err) {
1763                 trace_9p_protocol_dump(clnt, &req->rc);
1764                 p9_tag_remove(clnt, req);
1765                 goto error;
1766         }
1767
1768         p9_debug(P9_DEBUG_9P,
1769                 "<<< RGETATTR st_result_mask=%lld\n"
1770                 "<<< qid=%x.%llx.%x\n"
1771                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1772                 "<<< st_uid=%d st_gid=%d\n"
1773                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1774                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1775                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1776                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1777                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1778                 "<<< st_gen=%lld st_data_version=%lld\n",
1779                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1780                 ret->qid.version, ret->st_mode, ret->st_nlink,
1781                 from_kuid(&init_user_ns, ret->st_uid),
1782                 from_kgid(&init_user_ns, ret->st_gid),
1783                 ret->st_rdev, ret->st_size, ret->st_blksize,
1784                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1785                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1786                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1787                 ret->st_gen, ret->st_data_version);
1788
1789         p9_tag_remove(clnt, req);
1790         return ret;
1791
1792 error:
1793         kfree(ret);
1794         return ERR_PTR(err);
1795 }
1796 EXPORT_SYMBOL(p9_client_getattr_dotl);
1797
1798 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1799 {
1800         int ret;
1801
1802         /* NOTE: size shouldn't include its own length */
1803         /* size[2] type[2] dev[4] qid[13] */
1804         /* mode[4] atime[4] mtime[4] length[8]*/
1805         /* name[s] uid[s] gid[s] muid[s] */
1806         ret = 2+4+13+4+4+4+8+2+2+2+2;
1807
1808         if (wst->name)
1809                 ret += strlen(wst->name);
1810         if (wst->uid)
1811                 ret += strlen(wst->uid);
1812         if (wst->gid)
1813                 ret += strlen(wst->gid);
1814         if (wst->muid)
1815                 ret += strlen(wst->muid);
1816
1817         if ((proto_version == p9_proto_2000u) ||
1818                 (proto_version == p9_proto_2000L)) {
1819                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1820                 if (wst->extension)
1821                         ret += strlen(wst->extension);
1822         }
1823
1824         return ret;
1825 }
1826
1827 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1828 {
1829         int err;
1830         struct p9_req_t *req;
1831         struct p9_client *clnt;
1832
1833         err = 0;
1834         clnt = fid->clnt;
1835         wst->size = p9_client_statsize(wst, clnt->proto_version);
1836         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1837         p9_debug(P9_DEBUG_9P,
1838                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1839                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1840                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1841                 "     uid=%d gid=%d n_muid=%d\n",
1842                 wst->size, wst->type, wst->dev, wst->qid.type,
1843                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1844                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1845                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1846                 from_kuid(&init_user_ns, wst->n_uid),
1847                 from_kgid(&init_user_ns, wst->n_gid),
1848                 from_kuid(&init_user_ns, wst->n_muid));
1849
1850         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1851         if (IS_ERR(req)) {
1852                 err = PTR_ERR(req);
1853                 goto error;
1854         }
1855
1856         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1857
1858         p9_tag_remove(clnt, req);
1859 error:
1860         return err;
1861 }
1862 EXPORT_SYMBOL(p9_client_wstat);
1863
1864 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1865 {
1866         int err;
1867         struct p9_req_t *req;
1868         struct p9_client *clnt;
1869
1870         err = 0;
1871         clnt = fid->clnt;
1872         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1873         p9_debug(P9_DEBUG_9P,
1874                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1875                 "    atime_sec=%lld atime_nsec=%lld\n"
1876                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1877                 p9attr->valid, p9attr->mode,
1878                 from_kuid(&init_user_ns, p9attr->uid),
1879                 from_kgid(&init_user_ns, p9attr->gid),
1880                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1881                 p9attr->mtime_sec, p9attr->mtime_nsec);
1882
1883         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1884
1885         if (IS_ERR(req)) {
1886                 err = PTR_ERR(req);
1887                 goto error;
1888         }
1889         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1890         p9_tag_remove(clnt, req);
1891 error:
1892         return err;
1893 }
1894 EXPORT_SYMBOL(p9_client_setattr);
1895
1896 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1897 {
1898         int err;
1899         struct p9_req_t *req;
1900         struct p9_client *clnt;
1901
1902         err = 0;
1903         clnt = fid->clnt;
1904
1905         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1906
1907         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1908         if (IS_ERR(req)) {
1909                 err = PTR_ERR(req);
1910                 goto error;
1911         }
1912
1913         err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1914                           &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1915                           &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1916         if (err) {
1917                 trace_9p_protocol_dump(clnt, &req->rc);
1918                 p9_tag_remove(clnt, req);
1919                 goto error;
1920         }
1921
1922         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1923                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1924                 "fsid %llu namelen %ld\n",
1925                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1926                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1927                 sb->fsid, (long int)sb->namelen);
1928
1929         p9_tag_remove(clnt, req);
1930 error:
1931         return err;
1932 }
1933 EXPORT_SYMBOL(p9_client_statfs);
1934
1935 int p9_client_rename(struct p9_fid *fid,
1936                      struct p9_fid *newdirfid, const char *name)
1937 {
1938         int err;
1939         struct p9_req_t *req;
1940         struct p9_client *clnt;
1941
1942         err = 0;
1943         clnt = fid->clnt;
1944
1945         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1946                         fid->fid, newdirfid->fid, name);
1947
1948         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1949                         newdirfid->fid, name);
1950         if (IS_ERR(req)) {
1951                 err = PTR_ERR(req);
1952                 goto error;
1953         }
1954
1955         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1956
1957         p9_tag_remove(clnt, req);
1958 error:
1959         return err;
1960 }
1961 EXPORT_SYMBOL(p9_client_rename);
1962
1963 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1964                        struct p9_fid *newdirfid, const char *new_name)
1965 {
1966         int err;
1967         struct p9_req_t *req;
1968         struct p9_client *clnt;
1969
1970         err = 0;
1971         clnt = olddirfid->clnt;
1972
1973         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1974                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1975                    newdirfid->fid, new_name);
1976
1977         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1978                             old_name, newdirfid->fid, new_name);
1979         if (IS_ERR(req)) {
1980                 err = PTR_ERR(req);
1981                 goto error;
1982         }
1983
1984         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1985                    newdirfid->fid, new_name);
1986
1987         p9_tag_remove(clnt, req);
1988 error:
1989         return err;
1990 }
1991 EXPORT_SYMBOL(p9_client_renameat);
1992
1993 /*
1994  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1995  */
1996 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1997                                 const char *attr_name, u64 *attr_size)
1998 {
1999         int err;
2000         struct p9_req_t *req;
2001         struct p9_client *clnt;
2002         struct p9_fid *attr_fid;
2003
2004         err = 0;
2005         clnt = file_fid->clnt;
2006         attr_fid = p9_fid_create(clnt);
2007         if (!attr_fid) {
2008                 err = -ENOMEM;
2009                 goto error;
2010         }
2011         p9_debug(P9_DEBUG_9P,
2012                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2013                 file_fid->fid, attr_fid->fid, attr_name);
2014
2015         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2016                         file_fid->fid, attr_fid->fid, attr_name);
2017         if (IS_ERR(req)) {
2018                 err = PTR_ERR(req);
2019                 goto error;
2020         }
2021         err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
2022         if (err) {
2023                 trace_9p_protocol_dump(clnt, &req->rc);
2024                 p9_tag_remove(clnt, req);
2025                 goto clunk_fid;
2026         }
2027         p9_tag_remove(clnt, req);
2028         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2029                 attr_fid->fid, *attr_size);
2030         return attr_fid;
2031 clunk_fid:
2032         p9_client_clunk(attr_fid);
2033         attr_fid = NULL;
2034 error:
2035         if (attr_fid && (attr_fid != file_fid))
2036                 p9_fid_destroy(attr_fid);
2037
2038         return ERR_PTR(err);
2039 }
2040 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2041
2042 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2043                         u64 attr_size, int flags)
2044 {
2045         int err;
2046         struct p9_req_t *req;
2047         struct p9_client *clnt;
2048
2049         p9_debug(P9_DEBUG_9P,
2050                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2051                 fid->fid, name, (long long)attr_size, flags);
2052         err = 0;
2053         clnt = fid->clnt;
2054         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2055                         fid->fid, name, attr_size, flags);
2056         if (IS_ERR(req)) {
2057                 err = PTR_ERR(req);
2058                 goto error;
2059         }
2060         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2061         p9_tag_remove(clnt, req);
2062 error:
2063         return err;
2064 }
2065 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2066
2067 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2068 {
2069         int err, rsize, non_zc = 0;
2070         struct p9_client *clnt;
2071         struct p9_req_t *req;
2072         char *dataptr;
2073         struct kvec kv = {.iov_base = data, .iov_len = count};
2074         struct iov_iter to;
2075
2076         iov_iter_kvec(&to, READ, &kv, 1, count);
2077
2078         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2079                                 fid->fid, (unsigned long long) offset, count);
2080
2081         err = 0;
2082         clnt = fid->clnt;
2083
2084         rsize = fid->iounit;
2085         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2086                 rsize = clnt->msize - P9_READDIRHDRSZ;
2087
2088         if (count < rsize)
2089                 rsize = count;
2090
2091         /* Don't bother zerocopy for small IO (< 1024) */
2092         if (clnt->trans_mod->zc_request && rsize > 1024) {
2093                 /*
2094                  * response header len is 11
2095                  * PDU Header(7) + IO Size (4)
2096                  */
2097                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2098                                        11, "dqd", fid->fid, offset, rsize);
2099         } else {
2100                 non_zc = 1;
2101                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2102                                     offset, rsize);
2103         }
2104         if (IS_ERR(req)) {
2105                 err = PTR_ERR(req);
2106                 goto error;
2107         }
2108
2109         err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
2110         if (err) {
2111                 trace_9p_protocol_dump(clnt, &req->rc);
2112                 goto free_and_error;
2113         }
2114         if (rsize < count) {
2115                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2116                 count = rsize;
2117         }
2118
2119         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2120
2121         if (non_zc)
2122                 memmove(data, dataptr, count);
2123
2124         p9_tag_remove(clnt, req);
2125         return count;
2126
2127 free_and_error:
2128         p9_tag_remove(clnt, req);
2129 error:
2130         return err;
2131 }
2132 EXPORT_SYMBOL(p9_client_readdir);
2133
2134 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2135                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2136 {
2137         int err;
2138         struct p9_client *clnt;
2139         struct p9_req_t *req;
2140
2141         err = 0;
2142         clnt = fid->clnt;
2143         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2144                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2145         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2146                 MAJOR(rdev), MINOR(rdev), gid);
2147         if (IS_ERR(req))
2148                 return PTR_ERR(req);
2149
2150         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2151         if (err) {
2152                 trace_9p_protocol_dump(clnt, &req->rc);
2153                 goto error;
2154         }
2155         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2156                                 (unsigned long long)qid->path, qid->version);
2157
2158 error:
2159         p9_tag_remove(clnt, req);
2160         return err;
2161
2162 }
2163 EXPORT_SYMBOL(p9_client_mknod_dotl);
2164
2165 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2166                                 kgid_t gid, struct p9_qid *qid)
2167 {
2168         int err;
2169         struct p9_client *clnt;
2170         struct p9_req_t *req;
2171
2172         err = 0;
2173         clnt = fid->clnt;
2174         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2175                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2176         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2177                 gid);
2178         if (IS_ERR(req))
2179                 return PTR_ERR(req);
2180
2181         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2182         if (err) {
2183                 trace_9p_protocol_dump(clnt, &req->rc);
2184                 goto error;
2185         }
2186         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2187                                 (unsigned long long)qid->path, qid->version);
2188
2189 error:
2190         p9_tag_remove(clnt, req);
2191         return err;
2192
2193 }
2194 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2195
2196 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2197 {
2198         int err;
2199         struct p9_client *clnt;
2200         struct p9_req_t *req;
2201
2202         err = 0;
2203         clnt = fid->clnt;
2204         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2205                         "start %lld length %lld proc_id %d client_id %s\n",
2206                         fid->fid, flock->type, flock->flags, flock->start,
2207                         flock->length, flock->proc_id, flock->client_id);
2208
2209         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2210                                 flock->flags, flock->start, flock->length,
2211                                         flock->proc_id, flock->client_id);
2212
2213         if (IS_ERR(req))
2214                 return PTR_ERR(req);
2215
2216         err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
2217         if (err) {
2218                 trace_9p_protocol_dump(clnt, &req->rc);
2219                 goto error;
2220         }
2221         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2222 error:
2223         p9_tag_remove(clnt, req);
2224         return err;
2225
2226 }
2227 EXPORT_SYMBOL(p9_client_lock_dotl);
2228
2229 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2230 {
2231         int err;
2232         struct p9_client *clnt;
2233         struct p9_req_t *req;
2234
2235         err = 0;
2236         clnt = fid->clnt;
2237         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2238                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2239                 glock->start, glock->length, glock->proc_id, glock->client_id);
2240
2241         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2242                 glock->start, glock->length, glock->proc_id, glock->client_id);
2243
2244         if (IS_ERR(req))
2245                 return PTR_ERR(req);
2246
2247         err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type,
2248                           &glock->start, &glock->length, &glock->proc_id,
2249                           &glock->client_id);
2250         if (err) {
2251                 trace_9p_protocol_dump(clnt, &req->rc);
2252                 goto error;
2253         }
2254         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2255                 "proc_id %d client_id %s\n", glock->type, glock->start,
2256                 glock->length, glock->proc_id, glock->client_id);
2257 error:
2258         p9_tag_remove(clnt, req);
2259         return err;
2260 }
2261 EXPORT_SYMBOL(p9_client_getlock_dotl);
2262
2263 int p9_client_readlink(struct p9_fid *fid, char **target)
2264 {
2265         int err;
2266         struct p9_client *clnt;
2267         struct p9_req_t *req;
2268
2269         err = 0;
2270         clnt = fid->clnt;
2271         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2272
2273         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2274         if (IS_ERR(req))
2275                 return PTR_ERR(req);
2276
2277         err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
2278         if (err) {
2279                 trace_9p_protocol_dump(clnt, &req->rc);
2280                 goto error;
2281         }
2282         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2283 error:
2284         p9_tag_remove(clnt, req);
2285         return err;
2286 }
2287 EXPORT_SYMBOL(p9_client_readlink);
2288
2289 int __init p9_client_init(void)
2290 {
2291         p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU);
2292         return p9_req_cache ? 0 : -ENOMEM;
2293 }
2294
2295 void __exit p9_client_exit(void)
2296 {
2297         kmem_cache_destroy(p9_req_cache);
2298 }