linux/net/9p/client.c
<<
>>
Prefs
   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 <ericvh@gmail.com>
   8 *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   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
  38enum {
  39        Opt_msize,
  40        Opt_trans,
  41        Opt_legacy,
  42        Opt_version,
  43        Opt_err,
  44};
  45
  46static 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
  54inline int p9_is_proto_dotl(struct p9_client *clnt)
  55{
  56        return clnt->proto_version == p9_proto_2000L;
  57}
  58EXPORT_SYMBOL(p9_is_proto_dotl);
  59
  60inline int p9_is_proto_dotu(struct p9_client *clnt)
  61{
  62        return clnt->proto_version == p9_proto_2000u;
  63}
  64EXPORT_SYMBOL(p9_is_proto_dotu);
  65
  66int 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}
  88EXPORT_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 */
  94static 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 */
 105static 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_opts - 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
 132static 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
 218free_and_return:
 219        if (ret)
 220                v9fs_put_trans(clnt->trans_mod);
 221        kfree(tmp_options);
 222        return ret;
 223}
 224
 225static 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
 241void 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}
 254EXPORT_SYMBOL(p9_fcall_fini);
 255
 256static struct kmem_cache *p9_req_cache;
 257
 258/**
 259 * p9_tag_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 */
 267static struct p9_req_t *
 268p9_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
 316free:
 317        p9_fcall_fini(&req->tc);
 318        p9_fcall_fini(&req->rc);
 319free_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 */
 332struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 333{
 334        struct p9_req_t *req;
 335
 336        rcu_read_lock();
 337again:
 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}
 356EXPORT_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 */
 365static 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
 377static 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
 385int p9_req_put(struct p9_req_t *r)
 386{
 387        return kref_put(&r->refcount, p9_req_free);
 388}
 389EXPORT_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 */
 398static 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 * @status: request status, one of REQ_STATUS_*
 418 *
 419 */
 420void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 421{
 422        p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc.tag);
 423
 424        /*
 425         * This barrier is needed to make sure any change made to req before
 426         * the status change is visible to another thread
 427         */
 428        smp_wmb();
 429        req->status = status;
 430
 431        wake_up(&req->wq);
 432        p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc.tag);
 433        p9_req_put(req);
 434}
 435EXPORT_SYMBOL(p9_client_cb);
 436
 437/**
 438 * p9_parse_header - parse header arguments out of a packet
 439 * @pdu: packet to parse
 440 * @size: size of packet
 441 * @type: type of request
 442 * @tag: tag of packet
 443 * @rewind: set if we need to rewind offset afterwards
 444 */
 445
 446int
 447p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 448                                                                int rewind)
 449{
 450        int8_t r_type;
 451        int16_t r_tag;
 452        int32_t r_size;
 453        int offset = pdu->offset;
 454        int err;
 455
 456        pdu->offset = 0;
 457
 458        err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 459        if (err)
 460                goto rewind_and_exit;
 461
 462        if (type)
 463                *type = r_type;
 464        if (tag)
 465                *tag = r_tag;
 466        if (size)
 467                *size = r_size;
 468
 469        if (pdu->size != r_size || r_size < 7) {
 470                err = -EINVAL;
 471                goto rewind_and_exit;
 472        }
 473
 474        pdu->id = r_type;
 475        pdu->tag = r_tag;
 476
 477        p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 478                 pdu->size, pdu->id, pdu->tag);
 479
 480rewind_and_exit:
 481        if (rewind)
 482                pdu->offset = offset;
 483        return err;
 484}
 485EXPORT_SYMBOL(p9_parse_header);
 486
 487/**
 488 * p9_check_errors - check 9p packet for error return and process it
 489 * @c: current client instance
 490 * @req: request to parse and check for error conditions
 491 *
 492 * returns error code if one is discovered, otherwise returns 0
 493 *
 494 * this will have to be more complicated if we have multiple
 495 * error packet types
 496 */
 497
 498static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 499{
 500        int8_t type;
 501        int err;
 502        int ecode;
 503
 504        err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
 505        if (req->rc.size >= c->msize) {
 506                p9_debug(P9_DEBUG_ERROR,
 507                         "requested packet size too big: %d\n",
 508                         req->rc.size);
 509                return -EIO;
 510        }
 511        /*
 512         * dump the response from server
 513         * This should be after check errors which poplulate pdu_fcall.
 514         */
 515        trace_9p_protocol_dump(c, &req->rc);
 516        if (err) {
 517                p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 518                return err;
 519        }
 520        if (type != P9_RERROR && type != P9_RLERROR)
 521                return 0;
 522
 523        if (!p9_is_proto_dotl(c)) {
 524                char *ename;
 525                err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
 526                                  &ename, &ecode);
 527                if (err)
 528                        goto out_err;
 529
 530                if (p9_is_proto_dotu(c) && ecode < 512)
 531                        err = -ecode;
 532
 533                if (!err) {
 534                        err = p9_errstr2errno(ename, strlen(ename));
 535
 536                        p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 537                                 -ecode, ename);
 538                }
 539                kfree(ename);
 540        } else {
 541                err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
 542                err = -ecode;
 543
 544                p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 545        }
 546
 547        return err;
 548
 549out_err:
 550        p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 551
 552        return err;
 553}
 554
 555/**
 556 * p9_check_zc_errors - check 9p packet for error return and process it
 557 * @c: current client instance
 558 * @req: request to parse and check for error conditions
 559 * @uidata: external buffer containing error
 560 * @in_hdrlen: Size of response protocol buffer.
 561 *
 562 * returns error code if one is discovered, otherwise returns 0
 563 *
 564 * this will have to be more complicated if we have multiple
 565 * error packet types
 566 */
 567
 568static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 569                              struct iov_iter *uidata, int in_hdrlen)
 570{
 571        int err;
 572        int ecode;
 573        int8_t type;
 574        char *ename = NULL;
 575
 576        err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
 577        /*
 578         * dump the response from server
 579         * This should be after parse_header which poplulate pdu_fcall.
 580         */
 581        trace_9p_protocol_dump(c, &req->rc);
 582        if (err) {
 583                p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 584                return err;
 585        }
 586
 587        if (type != P9_RERROR && type != P9_RLERROR)
 588                return 0;
 589
 590        if (!p9_is_proto_dotl(c)) {
 591                /* Error is reported in string format */
 592                int len;
 593                /* 7 = header size for RERROR; */
 594                int inline_len = in_hdrlen - 7;
 595
 596                len = req->rc.size - req->rc.offset;
 597                if (len > (P9_ZC_HDR_SZ - 7)) {
 598                        err = -EFAULT;
 599                        goto out_err;
 600                }
 601
 602                ename = &req->rc.sdata[req->rc.offset];
 603                if (len > inline_len) {
 604                        /* We have error in external buffer */
 605                        if (!copy_from_iter_full(ename + inline_len,
 606                                             len - inline_len, uidata)) {
 607                                err = -EFAULT;
 608                                goto out_err;
 609                        }
 610                }
 611                ename = NULL;
 612                err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
 613                                  &ename, &ecode);
 614                if (err)
 615                        goto out_err;
 616
 617                if (p9_is_proto_dotu(c) && ecode < 512)
 618                        err = -ecode;
 619
 620                if (!err) {
 621                        err = p9_errstr2errno(ename, strlen(ename));
 622
 623                        p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 624                                 -ecode, ename);
 625                }
 626                kfree(ename);
 627        } else {
 628                err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
 629                err = -ecode;
 630
 631                p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 632        }
 633        return err;
 634
 635out_err:
 636        p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 637        return err;
 638}
 639
 640static struct p9_req_t *
 641p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 642
 643/**
 644 * p9_client_flush - flush (cancel) a request
 645 * @c: client state
 646 * @oldreq: request to cancel
 647 *
 648 * This sents a flush for a particular request and links
 649 * the flush request to the original request.  The current
 650 * code only supports a single flush request although the protocol
 651 * allows for multiple flush requests to be sent for a single request.
 652 *
 653 */
 654
 655static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 656{
 657        struct p9_req_t *req;
 658        int16_t oldtag;
 659        int err;
 660
 661        err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
 662        if (err)
 663                return err;
 664
 665        p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 666
 667        req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 668        if (IS_ERR(req))
 669                return PTR_ERR(req);
 670
 671        /*
 672         * if we haven't received a response for oldreq,
 673         * remove it from the list
 674         */
 675        if (oldreq->status == REQ_STATUS_SENT) {
 676                if (c->trans_mod->cancelled)
 677                        c->trans_mod->cancelled(c, oldreq);
 678        }
 679
 680        p9_tag_remove(c, req);
 681        return 0;
 682}
 683
 684static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 685                                              int8_t type, int req_size,
 686                                              const char *fmt, va_list ap)
 687{
 688        int err;
 689        struct p9_req_t *req;
 690
 691        p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 692
 693        /* we allow for any status other than disconnected */
 694        if (c->status == Disconnected)
 695                return ERR_PTR(-EIO);
 696
 697        /* if status is begin_disconnected we allow only clunk request */
 698        if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 699                return ERR_PTR(-EIO);
 700
 701        req = p9_tag_alloc(c, type, req_size);
 702        if (IS_ERR(req))
 703                return req;
 704
 705        /* marshall the data */
 706        p9pdu_prepare(&req->tc, req->tc.tag, type);
 707        err = p9pdu_vwritef(&req->tc, c->proto_version, fmt, ap);
 708        if (err)
 709                goto reterr;
 710        p9pdu_finalize(c, &req->tc);
 711        trace_9p_client_req(c, type, req->tc.tag);
 712        return req;
 713reterr:
 714        p9_tag_remove(c, req);
 715        /* We have to put also the 2nd reference as it won't be used */
 716        p9_req_put(req);
 717        return ERR_PTR(err);
 718}
 719
 720/**
 721 * p9_client_rpc - issue a request and wait for a response
 722 * @c: client session
 723 * @type: type of request
 724 * @fmt: protocol format string (see protocol.c)
 725 *
 726 * Returns request structure (which client must free using p9_tag_remove)
 727 */
 728
 729static struct p9_req_t *
 730p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 731{
 732        va_list ap;
 733        int sigpending, err;
 734        unsigned long flags;
 735        struct p9_req_t *req;
 736
 737        va_start(ap, fmt);
 738        req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 739        va_end(ap);
 740        if (IS_ERR(req))
 741                return req;
 742
 743        if (signal_pending(current)) {
 744                sigpending = 1;
 745                clear_thread_flag(TIF_SIGPENDING);
 746        } else
 747                sigpending = 0;
 748
 749        err = c->trans_mod->request(c, req);
 750        if (err < 0) {
 751                /* write won't happen */
 752                p9_req_put(req);
 753                if (err != -ERESTARTSYS && err != -EFAULT)
 754                        c->status = Disconnected;
 755                goto recalc_sigpending;
 756        }
 757again:
 758        /* Wait for the response */
 759        err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
 760
 761        /*
 762         * Make sure our req is coherent with regard to updates in other
 763         * threads - echoes to wmb() in the callback
 764         */
 765        smp_rmb();
 766
 767        if ((err == -ERESTARTSYS) && (c->status == Connected)
 768                                  && (type == P9_TFLUSH)) {
 769                sigpending = 1;
 770                clear_thread_flag(TIF_SIGPENDING);
 771                goto again;
 772        }
 773
 774        if (req->status == REQ_STATUS_ERROR) {
 775                p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 776                err = req->t_err;
 777        }
 778        if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 779                p9_debug(P9_DEBUG_MUX, "flushing\n");
 780                sigpending = 1;
 781                clear_thread_flag(TIF_SIGPENDING);
 782
 783                if (c->trans_mod->cancel(c, req))
 784                        p9_client_flush(c, req);
 785
 786                /* if we received the response anyway, don't signal error */
 787                if (req->status == REQ_STATUS_RCVD)
 788                        err = 0;
 789        }
 790recalc_sigpending:
 791        if (sigpending) {
 792                spin_lock_irqsave(&current->sighand->siglock, flags);
 793                recalc_sigpending();
 794                spin_unlock_irqrestore(&current->sighand->siglock, flags);
 795        }
 796        if (err < 0)
 797                goto reterr;
 798
 799        err = p9_check_errors(c, req);
 800        trace_9p_client_res(c, type, req->rc.tag, err);
 801        if (!err)
 802                return req;
 803reterr:
 804        p9_tag_remove(c, req);
 805        return ERR_PTR(safe_errno(err));
 806}
 807
 808/**
 809 * p9_client_zc_rpc - issue a request and wait for a response
 810 * @c: client session
 811 * @type: type of request
 812 * @uidata: destination for zero copy read
 813 * @uodata: source for zero copy write
 814 * @inlen: read buffer size
 815 * @olen: write buffer size
 816 * @in_hdrlen: reader header size, This is the size of response protocol data
 817 * @fmt: protocol format string (see protocol.c)
 818 *
 819 * Returns request structure (which client must free using p9_tag_remove)
 820 */
 821static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 822                                         struct iov_iter *uidata,
 823                                         struct iov_iter *uodata,
 824                                         int inlen, int olen, int in_hdrlen,
 825                                         const char *fmt, ...)
 826{
 827        va_list ap;
 828        int sigpending, err;
 829        unsigned long flags;
 830        struct p9_req_t *req;
 831
 832        va_start(ap, fmt);
 833        /*
 834         * We allocate a inline protocol data of only 4k bytes.
 835         * The actual content is passed in zero-copy fashion.
 836         */
 837        req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 838        va_end(ap);
 839        if (IS_ERR(req))
 840                return req;
 841
 842        if (signal_pending(current)) {
 843                sigpending = 1;
 844                clear_thread_flag(TIF_SIGPENDING);
 845        } else
 846                sigpending = 0;
 847
 848        err = c->trans_mod->zc_request(c, req, uidata, uodata,
 849                                       inlen, olen, in_hdrlen);
 850        if (err < 0) {
 851                if (err == -EIO)
 852                        c->status = Disconnected;
 853                if (err != -ERESTARTSYS)
 854                        goto recalc_sigpending;
 855        }
 856        if (req->status == REQ_STATUS_ERROR) {
 857                p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 858                err = req->t_err;
 859        }
 860        if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 861                p9_debug(P9_DEBUG_MUX, "flushing\n");
 862                sigpending = 1;
 863                clear_thread_flag(TIF_SIGPENDING);
 864
 865                if (c->trans_mod->cancel(c, req))
 866                        p9_client_flush(c, req);
 867
 868                /* if we received the response anyway, don't signal error */
 869                if (req->status == REQ_STATUS_RCVD)
 870                        err = 0;
 871        }
 872recalc_sigpending:
 873        if (sigpending) {
 874                spin_lock_irqsave(&current->sighand->siglock, flags);
 875                recalc_sigpending();
 876                spin_unlock_irqrestore(&current->sighand->siglock, flags);
 877        }
 878        if (err < 0)
 879                goto reterr;
 880
 881        err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 882        trace_9p_client_res(c, type, req->rc.tag, err);
 883        if (!err)
 884                return req;
 885reterr:
 886        p9_tag_remove(c, req);
 887        return ERR_PTR(safe_errno(err));
 888}
 889
 890static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 891{
 892        int ret;
 893        struct p9_fid *fid;
 894
 895        p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 896        fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 897        if (!fid)
 898                return NULL;
 899
 900        memset(&fid->qid, 0, sizeof(struct p9_qid));
 901        fid->mode = -1;
 902        fid->uid = current_fsuid();
 903        fid->clnt = clnt;
 904        fid->rdir = NULL;
 905        fid->fid = 0;
 906        refcount_set(&fid->count, 1);
 907
 908        idr_preload(GFP_KERNEL);
 909        spin_lock_irq(&clnt->lock);
 910        ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
 911                            GFP_NOWAIT);
 912        spin_unlock_irq(&clnt->lock);
 913        idr_preload_end();
 914        if (!ret)
 915                return fid;
 916
 917        kfree(fid);
 918        return NULL;
 919}
 920
 921static void p9_fid_destroy(struct p9_fid *fid)
 922{
 923        struct p9_client *clnt;
 924        unsigned long flags;
 925
 926        p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 927        clnt = fid->clnt;
 928        spin_lock_irqsave(&clnt->lock, flags);
 929        idr_remove(&clnt->fids, fid->fid);
 930        spin_unlock_irqrestore(&clnt->lock, flags);
 931        kfree(fid->rdir);
 932        kfree(fid);
 933}
 934
 935static int p9_client_version(struct p9_client *c)
 936{
 937        int err = 0;
 938        struct p9_req_t *req;
 939        char *version = NULL;
 940        int msize;
 941
 942        p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 943                 c->msize, c->proto_version);
 944
 945        switch (c->proto_version) {
 946        case p9_proto_2000L:
 947                req = p9_client_rpc(c, P9_TVERSION, "ds",
 948                                        c->msize, "9P2000.L");
 949                break;
 950        case p9_proto_2000u:
 951                req = p9_client_rpc(c, P9_TVERSION, "ds",
 952                                        c->msize, "9P2000.u");
 953                break;
 954        case p9_proto_legacy:
 955                req = p9_client_rpc(c, P9_TVERSION, "ds",
 956                                        c->msize, "9P2000");
 957                break;
 958        default:
 959                return -EINVAL;
 960        }
 961
 962        if (IS_ERR(req))
 963                return PTR_ERR(req);
 964
 965        err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version);
 966        if (err) {
 967                p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 968                trace_9p_protocol_dump(c, &req->rc);
 969                goto error;
 970        }
 971
 972        p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 973        if (!strncmp(version, "9P2000.L", 8))
 974                c->proto_version = p9_proto_2000L;
 975        else if (!strncmp(version, "9P2000.u", 8))
 976                c->proto_version = p9_proto_2000u;
 977        else if (!strncmp(version, "9P2000", 6))
 978                c->proto_version = p9_proto_legacy;
 979        else {
 980                p9_debug(P9_DEBUG_ERROR,
 981                         "server returned an unknown version: %s\n", version);
 982                err = -EREMOTEIO;
 983                goto error;
 984        }
 985
 986        if (msize < 4096) {
 987                p9_debug(P9_DEBUG_ERROR,
 988                         "server returned a msize < 4096: %d\n", msize);
 989                err = -EREMOTEIO;
 990                goto error;
 991        }
 992        if (msize < c->msize)
 993                c->msize = msize;
 994
 995error:
 996        kfree(version);
 997        p9_tag_remove(c, req);
 998
 999        return err;
1000}
1001
1002struct p9_client *p9_client_create(const char *dev_name, char *options)
1003{
1004        int err;
1005        struct p9_client *clnt;
1006        char *client_id;
1007
1008        err = 0;
1009        clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1010        if (!clnt)
1011                return ERR_PTR(-ENOMEM);
1012
1013        clnt->trans_mod = NULL;
1014        clnt->trans = NULL;
1015        clnt->fcall_cache = NULL;
1016
1017        client_id = utsname()->nodename;
1018        memcpy(clnt->name, client_id, strlen(client_id) + 1);
1019
1020        spin_lock_init(&clnt->lock);
1021        idr_init(&clnt->fids);
1022        idr_init(&clnt->reqs);
1023
1024        err = parse_opts(options, clnt);
1025        if (err < 0)
1026                goto free_client;
1027
1028        if (!clnt->trans_mod)
1029                clnt->trans_mod = v9fs_get_default_trans();
1030
1031        if (clnt->trans_mod == NULL) {
1032                err = -EPROTONOSUPPORT;
1033                p9_debug(P9_DEBUG_ERROR,
1034                         "No transport defined or default transport\n");
1035                goto free_client;
1036        }
1037
1038        p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1039                 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1040
1041        err = clnt->trans_mod->create(clnt, dev_name, options);
1042        if (err)
1043                goto put_trans;
1044
1045        if (clnt->msize > clnt->trans_mod->maxsize)
1046                clnt->msize = clnt->trans_mod->maxsize;
1047
1048        if (clnt->msize < 4096) {
1049                p9_debug(P9_DEBUG_ERROR,
1050                         "Please specify a msize of at least 4k\n");
1051                err = -EINVAL;
1052                goto close_trans;
1053        }
1054
1055        err = p9_client_version(clnt);
1056        if (err)
1057                goto close_trans;
1058
1059        /* P9_HDRSZ + 4 is the smallest packet header we can have that is
1060         * followed by data accessed from userspace by read
1061         */
1062        clnt->fcall_cache =
1063                kmem_cache_create_usercopy("9p-fcall-cache", clnt->msize,
1064                                           0, 0, P9_HDRSZ + 4,
1065                                           clnt->msize - (P9_HDRSZ + 4),
1066                                           NULL);
1067
1068        return clnt;
1069
1070close_trans:
1071        clnt->trans_mod->close(clnt);
1072put_trans:
1073        v9fs_put_trans(clnt->trans_mod);
1074free_client:
1075        kfree(clnt);
1076        return ERR_PTR(err);
1077}
1078EXPORT_SYMBOL(p9_client_create);
1079
1080void p9_client_destroy(struct p9_client *clnt)
1081{
1082        struct p9_fid *fid;
1083        int id;
1084
1085        p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1086
1087        if (clnt->trans_mod)
1088                clnt->trans_mod->close(clnt);
1089
1090        v9fs_put_trans(clnt->trans_mod);
1091
1092        idr_for_each_entry(&clnt->fids, fid, id) {
1093                pr_info("Found fid %d not clunked\n", fid->fid);
1094                p9_fid_destroy(fid);
1095        }
1096
1097        p9_tag_cleanup(clnt);
1098
1099        kmem_cache_destroy(clnt->fcall_cache);
1100        kfree(clnt);
1101}
1102EXPORT_SYMBOL(p9_client_destroy);
1103
1104void p9_client_disconnect(struct p9_client *clnt)
1105{
1106        p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1107        clnt->status = Disconnected;
1108}
1109EXPORT_SYMBOL(p9_client_disconnect);
1110
1111void p9_client_begin_disconnect(struct p9_client *clnt)
1112{
1113        p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1114        clnt->status = BeginDisconnect;
1115}
1116EXPORT_SYMBOL(p9_client_begin_disconnect);
1117
1118struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1119        const char *uname, kuid_t n_uname, const char *aname)
1120{
1121        int err = 0;
1122        struct p9_req_t *req;
1123        struct p9_fid *fid;
1124        struct p9_qid qid;
1125
1126
1127        p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1128                 afid ? afid->fid : -1, uname, aname);
1129        fid = p9_fid_create(clnt);
1130        if (!fid) {
1131                err = -ENOMEM;
1132                goto error;
1133        }
1134        fid->uid = n_uname;
1135
1136        req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1137                        afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1138        if (IS_ERR(req)) {
1139                err = PTR_ERR(req);
1140                goto error;
1141        }
1142
1143        err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
1144        if (err) {
1145                trace_9p_protocol_dump(clnt, &req->rc);
1146                p9_tag_remove(clnt, req);
1147                goto error;
1148        }
1149
1150        p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1151                 qid.type, (unsigned long long)qid.path, qid.version);
1152
1153        memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1154
1155        p9_tag_remove(clnt, req);
1156        return fid;
1157
1158error:
1159        if (fid)
1160                p9_fid_destroy(fid);
1161        return ERR_PTR(err);
1162}
1163EXPORT_SYMBOL(p9_client_attach);
1164
1165struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1166                const unsigned char * const *wnames, int clone)
1167{
1168        int err;
1169        struct p9_client *clnt;
1170        struct p9_fid *fid;
1171        struct p9_qid *wqids;
1172        struct p9_req_t *req;
1173        uint16_t nwqids, count;
1174
1175        err = 0;
1176        wqids = NULL;
1177        clnt = oldfid->clnt;
1178        if (clone) {
1179                fid = p9_fid_create(clnt);
1180                if (!fid) {
1181                        err = -ENOMEM;
1182                        goto error;
1183                }
1184
1185                fid->uid = oldfid->uid;
1186        } else
1187                fid = oldfid;
1188
1189
1190        p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1191                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1192        req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1193                                                                nwname, wnames);
1194        if (IS_ERR(req)) {
1195                err = PTR_ERR(req);
1196                goto error;
1197        }
1198
1199        err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1200        if (err) {
1201                trace_9p_protocol_dump(clnt, &req->rc);
1202                p9_tag_remove(clnt, req);
1203                goto clunk_fid;
1204        }
1205        p9_tag_remove(clnt, req);
1206
1207        p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1208
1209        if (nwqids != nwname) {
1210                err = -ENOENT;
1211                goto clunk_fid;
1212        }
1213
1214        for (count = 0; count < nwqids; count++)
1215                p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1216                        count, wqids[count].type,
1217                        (unsigned long long)wqids[count].path,
1218                        wqids[count].version);
1219
1220        if (nwname)
1221                memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1222        else
1223                memmove(&fid->qid, &oldfid->qid, sizeof(struct p9_qid));
1224
1225        kfree(wqids);
1226        return fid;
1227
1228clunk_fid:
1229        kfree(wqids);
1230        p9_client_clunk(fid);
1231        fid = NULL;
1232
1233error:
1234        if (fid && (fid != oldfid))
1235                p9_fid_destroy(fid);
1236
1237        return ERR_PTR(err);
1238}
1239EXPORT_SYMBOL(p9_client_walk);
1240
1241int p9_client_open(struct p9_fid *fid, int mode)
1242{
1243        int err;
1244        struct p9_client *clnt;
1245        struct p9_req_t *req;
1246        struct p9_qid qid;
1247        int iounit;
1248
1249        clnt = fid->clnt;
1250        p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1251                p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1252        err = 0;
1253
1254        if (fid->mode != -1)
1255                return -EINVAL;
1256
1257        if (p9_is_proto_dotl(clnt))
1258                req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1259        else
1260                req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1261        if (IS_ERR(req)) {
1262                err = PTR_ERR(req);
1263                goto error;
1264        }
1265
1266        err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1267        if (err) {
1268                trace_9p_protocol_dump(clnt, &req->rc);
1269                goto free_and_error;
1270        }
1271
1272        p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1273                p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1274                (unsigned long long)qid.path, qid.version, iounit);
1275
1276        memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1277        fid->mode = mode;
1278        fid->iounit = iounit;
1279
1280free_and_error:
1281        p9_tag_remove(clnt, req);
1282error:
1283        return err;
1284}
1285EXPORT_SYMBOL(p9_client_open);
1286
1287int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1288                kgid_t gid, struct p9_qid *qid)
1289{
1290        int err = 0;
1291        struct p9_client *clnt;
1292        struct p9_req_t *req;
1293        int iounit;
1294
1295        p9_debug(P9_DEBUG_9P,
1296                        ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1297                        ofid->fid, name, flags, mode,
1298                        from_kgid(&init_user_ns, gid));
1299        clnt = ofid->clnt;
1300
1301        if (ofid->mode != -1)
1302                return -EINVAL;
1303
1304        req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1305                        mode, gid);
1306        if (IS_ERR(req)) {
1307                err = PTR_ERR(req);
1308                goto error;
1309        }
1310
1311        err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
1312        if (err) {
1313                trace_9p_protocol_dump(clnt, &req->rc);
1314                goto free_and_error;
1315        }
1316
1317        p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1318                        qid->type,
1319                        (unsigned long long)qid->path,
1320                        qid->version, iounit);
1321
1322        memmove(&ofid->qid, qid, sizeof(struct p9_qid));
1323        ofid->mode = mode;
1324        ofid->iounit = iounit;
1325
1326free_and_error:
1327        p9_tag_remove(clnt, req);
1328error:
1329        return err;
1330}
1331EXPORT_SYMBOL(p9_client_create_dotl);
1332
1333int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1334                     char *extension)
1335{
1336        int err;
1337        struct p9_client *clnt;
1338        struct p9_req_t *req;
1339        struct p9_qid qid;
1340        int iounit;
1341
1342        p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1343                                                fid->fid, name, perm, mode);
1344        err = 0;
1345        clnt = fid->clnt;
1346
1347        if (fid->mode != -1)
1348                return -EINVAL;
1349
1350        req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1351                                mode, extension);
1352        if (IS_ERR(req)) {
1353                err = PTR_ERR(req);
1354                goto error;
1355        }
1356
1357        err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1358        if (err) {
1359                trace_9p_protocol_dump(clnt, &req->rc);
1360                goto free_and_error;
1361        }
1362
1363        p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1364                                qid.type,
1365                                (unsigned long long)qid.path,
1366                                qid.version, iounit);
1367
1368        memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1369        fid->mode = mode;
1370        fid->iounit = iounit;
1371
1372free_and_error:
1373        p9_tag_remove(clnt, req);
1374error:
1375        return err;
1376}
1377EXPORT_SYMBOL(p9_client_fcreate);
1378
1379int p9_client_symlink(struct p9_fid *dfid, const char *name,
1380                const char *symtgt, kgid_t gid, struct p9_qid *qid)
1381{
1382        int err = 0;
1383        struct p9_client *clnt;
1384        struct p9_req_t *req;
1385
1386        p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1387                        dfid->fid, name, symtgt);
1388        clnt = dfid->clnt;
1389
1390        req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1391                        gid);
1392        if (IS_ERR(req)) {
1393                err = PTR_ERR(req);
1394                goto error;
1395        }
1396
1397        err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
1398        if (err) {
1399                trace_9p_protocol_dump(clnt, &req->rc);
1400                goto free_and_error;
1401        }
1402
1403        p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1404                        qid->type, (unsigned long long)qid->path, qid->version);
1405
1406free_and_error:
1407        p9_tag_remove(clnt, req);
1408error:
1409        return err;
1410}
1411EXPORT_SYMBOL(p9_client_symlink);
1412
1413int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1414{
1415        struct p9_client *clnt;
1416        struct p9_req_t *req;
1417
1418        p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1419                        dfid->fid, oldfid->fid, newname);
1420        clnt = dfid->clnt;
1421        req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1422                        newname);
1423        if (IS_ERR(req))
1424                return PTR_ERR(req);
1425
1426        p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1427        p9_tag_remove(clnt, req);
1428        return 0;
1429}
1430EXPORT_SYMBOL(p9_client_link);
1431
1432int p9_client_fsync(struct p9_fid *fid, int datasync)
1433{
1434        int err;
1435        struct p9_client *clnt;
1436        struct p9_req_t *req;
1437
1438        p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1439                        fid->fid, datasync);
1440        err = 0;
1441        clnt = fid->clnt;
1442
1443        req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1444        if (IS_ERR(req)) {
1445                err = PTR_ERR(req);
1446                goto error;
1447        }
1448
1449        p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1450
1451        p9_tag_remove(clnt, req);
1452
1453error:
1454        return err;
1455}
1456EXPORT_SYMBOL(p9_client_fsync);
1457
1458int p9_client_clunk(struct p9_fid *fid)
1459{
1460        int err;
1461        struct p9_client *clnt;
1462        struct p9_req_t *req;
1463        int retries = 0;
1464
1465        if (!fid || IS_ERR(fid)) {
1466                pr_warn("%s (%d): Trying to clunk with invalid fid\n",
1467                        __func__, task_pid_nr(current));
1468                dump_stack();
1469                return 0;
1470        }
1471        if (!refcount_dec_and_test(&fid->count))
1472                return 0;
1473
1474again:
1475        p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1476                                                                retries);
1477        err = 0;
1478        clnt = fid->clnt;
1479
1480        req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1481        if (IS_ERR(req)) {
1482                err = PTR_ERR(req);
1483                goto error;
1484        }
1485
1486        p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1487
1488        p9_tag_remove(clnt, req);
1489error:
1490        /*
1491         * Fid is not valid even after a failed clunk
1492         * If interrupted, retry once then give up and
1493         * leak fid until umount.
1494         */
1495        if (err == -ERESTARTSYS) {
1496                if (retries++ == 0)
1497                        goto again;
1498        } else
1499                p9_fid_destroy(fid);
1500        return err;
1501}
1502EXPORT_SYMBOL(p9_client_clunk);
1503
1504int p9_client_remove(struct p9_fid *fid)
1505{
1506        int err;
1507        struct p9_client *clnt;
1508        struct p9_req_t *req;
1509
1510        p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1511        err = 0;
1512        clnt = fid->clnt;
1513
1514        req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1515        if (IS_ERR(req)) {
1516                err = PTR_ERR(req);
1517                goto error;
1518        }
1519
1520        p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1521
1522        p9_tag_remove(clnt, req);
1523error:
1524        if (err == -ERESTARTSYS)
1525                p9_client_clunk(fid);
1526        else
1527                p9_fid_destroy(fid);
1528        return err;
1529}
1530EXPORT_SYMBOL(p9_client_remove);
1531
1532int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1533{
1534        int err = 0;
1535        struct p9_req_t *req;
1536        struct p9_client *clnt;
1537
1538        p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1539                   dfid->fid, name, flags);
1540
1541        clnt = dfid->clnt;
1542        req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1543        if (IS_ERR(req)) {
1544                err = PTR_ERR(req);
1545                goto error;
1546        }
1547        p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1548
1549        p9_tag_remove(clnt, req);
1550error:
1551        return err;
1552}
1553EXPORT_SYMBOL(p9_client_unlinkat);
1554
1555int
1556p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1557{
1558        int total = 0;
1559        *err = 0;
1560
1561        while (iov_iter_count(to)) {
1562                int count;
1563
1564                count = p9_client_read_once(fid, offset, to, err);
1565                if (!count || *err)
1566                        break;
1567                offset += count;
1568                total += count;
1569        }
1570        return total;
1571}
1572EXPORT_SYMBOL(p9_client_read);
1573
1574int
1575p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
1576                    int *err)
1577{
1578        struct p9_client *clnt = fid->clnt;
1579        struct p9_req_t *req;
1580        int count = iov_iter_count(to);
1581        int rsize, non_zc = 0;
1582        char *dataptr;
1583
1584        *err = 0;
1585        p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1586                   fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1587
1588        rsize = fid->iounit;
1589        if (!rsize || rsize > clnt->msize - P9_IOHDRSZ)
1590                rsize = clnt->msize - P9_IOHDRSZ;
1591
1592        if (count < rsize)
1593                rsize = count;
1594
1595        /* Don't bother zerocopy for small IO (< 1024) */
1596        if (clnt->trans_mod->zc_request && rsize > 1024) {
1597                /* response header len is 11
1598                 * PDU Header(7) + IO Size (4)
1599                 */
1600                req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1601                                       0, 11, "dqd", fid->fid,
1602                                       offset, rsize);
1603        } else {
1604                non_zc = 1;
1605                req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1606                                    rsize);
1607        }
1608        if (IS_ERR(req)) {
1609                *err = PTR_ERR(req);
1610                return 0;
1611        }
1612
1613        *err = p9pdu_readf(&req->rc, clnt->proto_version,
1614                           "D", &count, &dataptr);
1615        if (*err) {
1616                trace_9p_protocol_dump(clnt, &req->rc);
1617                p9_tag_remove(clnt, req);
1618                return 0;
1619        }
1620        if (rsize < count) {
1621                pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1622                count = rsize;
1623        }
1624
1625        p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1626
1627        if (non_zc) {
1628                int n = copy_to_iter(dataptr, count, to);
1629
1630                if (n != count) {
1631                        *err = -EFAULT;
1632                        p9_tag_remove(clnt, req);
1633                        return n;
1634                }
1635        } else {
1636                iov_iter_advance(to, count);
1637        }
1638        p9_tag_remove(clnt, req);
1639        return count;
1640}
1641EXPORT_SYMBOL(p9_client_read_once);
1642
1643int
1644p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1645{
1646        struct p9_client *clnt = fid->clnt;
1647        struct p9_req_t *req;
1648        int total = 0;
1649        *err = 0;
1650
1651        p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1652                                fid->fid, (unsigned long long) offset,
1653                                iov_iter_count(from));
1654
1655        while (iov_iter_count(from)) {
1656                int count = iov_iter_count(from);
1657                int rsize = fid->iounit;
1658                if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1659                        rsize = clnt->msize - P9_IOHDRSZ;
1660
1661                if (count < rsize)
1662                        rsize = count;
1663
1664                /* Don't bother zerocopy for small IO (< 1024) */
1665                if (clnt->trans_mod->zc_request && rsize > 1024) {
1666                        req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1667                                               rsize, P9_ZC_HDR_SZ, "dqd",
1668                                               fid->fid, offset, rsize);
1669                } else {
1670                        req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1671                                                    offset, rsize, from);
1672                }
1673                if (IS_ERR(req)) {
1674                        *err = PTR_ERR(req);
1675                        break;
1676                }
1677
1678                *err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count);
1679                if (*err) {
1680                        trace_9p_protocol_dump(clnt, &req->rc);
1681                        p9_tag_remove(clnt, req);
1682                        break;
1683                }
1684                if (rsize < count) {
1685                        pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1686                        count = rsize;
1687                }
1688
1689                p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1690
1691                p9_tag_remove(clnt, req);
1692                iov_iter_advance(from, count);
1693                total += count;
1694                offset += count;
1695        }
1696        return total;
1697}
1698EXPORT_SYMBOL(p9_client_write);
1699
1700struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1701{
1702        int err;
1703        struct p9_client *clnt;
1704        struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1705        struct p9_req_t *req;
1706        u16 ignored;
1707
1708        p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1709
1710        if (!ret)
1711                return ERR_PTR(-ENOMEM);
1712
1713        err = 0;
1714        clnt = fid->clnt;
1715
1716        req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1717        if (IS_ERR(req)) {
1718                err = PTR_ERR(req);
1719                goto error;
1720        }
1721
1722        err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
1723        if (err) {
1724                trace_9p_protocol_dump(clnt, &req->rc);
1725                p9_tag_remove(clnt, req);
1726                goto error;
1727        }
1728
1729        p9_debug(P9_DEBUG_9P,
1730                "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1731                "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1732                "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1733                "<<<    uid=%d gid=%d n_muid=%d\n",
1734                ret->size, ret->type, ret->dev, ret->qid.type,
1735                (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1736                ret->atime, ret->mtime, (unsigned long long)ret->length,
1737                ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1738                from_kuid(&init_user_ns, ret->n_uid),
1739                from_kgid(&init_user_ns, ret->n_gid),
1740                from_kuid(&init_user_ns, ret->n_muid));
1741
1742        p9_tag_remove(clnt, req);
1743        return ret;
1744
1745error:
1746        kfree(ret);
1747        return ERR_PTR(err);
1748}
1749EXPORT_SYMBOL(p9_client_stat);
1750
1751struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1752                                                        u64 request_mask)
1753{
1754        int err;
1755        struct p9_client *clnt;
1756        struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1757                                                                GFP_KERNEL);
1758        struct p9_req_t *req;
1759
1760        p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1761                                                        fid->fid, request_mask);
1762
1763        if (!ret)
1764                return ERR_PTR(-ENOMEM);
1765
1766        err = 0;
1767        clnt = fid->clnt;
1768
1769        req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1770        if (IS_ERR(req)) {
1771                err = PTR_ERR(req);
1772                goto error;
1773        }
1774
1775        err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
1776        if (err) {
1777                trace_9p_protocol_dump(clnt, &req->rc);
1778                p9_tag_remove(clnt, req);
1779                goto error;
1780        }
1781
1782        p9_debug(P9_DEBUG_9P,
1783                "<<< RGETATTR st_result_mask=%lld\n"
1784                "<<< qid=%x.%llx.%x\n"
1785                "<<< st_mode=%8.8x st_nlink=%llu\n"
1786                "<<< st_uid=%d st_gid=%d\n"
1787                "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1788                "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1789                "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1790                "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1791                "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1792                "<<< st_gen=%lld st_data_version=%lld\n",
1793                ret->st_result_mask, ret->qid.type, ret->qid.path,
1794                ret->qid.version, ret->st_mode, ret->st_nlink,
1795                from_kuid(&init_user_ns, ret->st_uid),
1796                from_kgid(&init_user_ns, ret->st_gid),
1797                ret->st_rdev, ret->st_size, ret->st_blksize,
1798                ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1799                ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1800                ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1801                ret->st_gen, ret->st_data_version);
1802
1803        p9_tag_remove(clnt, req);
1804        return ret;
1805
1806error:
1807        kfree(ret);
1808        return ERR_PTR(err);
1809}
1810EXPORT_SYMBOL(p9_client_getattr_dotl);
1811
1812static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1813{
1814        int ret;
1815
1816        /* NOTE: size shouldn't include its own length */
1817        /* size[2] type[2] dev[4] qid[13] */
1818        /* mode[4] atime[4] mtime[4] length[8]*/
1819        /* name[s] uid[s] gid[s] muid[s] */
1820        ret = 2+4+13+4+4+4+8+2+2+2+2;
1821
1822        if (wst->name)
1823                ret += strlen(wst->name);
1824        if (wst->uid)
1825                ret += strlen(wst->uid);
1826        if (wst->gid)
1827                ret += strlen(wst->gid);
1828        if (wst->muid)
1829                ret += strlen(wst->muid);
1830
1831        if ((proto_version == p9_proto_2000u) ||
1832                (proto_version == p9_proto_2000L)) {
1833                ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1834                if (wst->extension)
1835                        ret += strlen(wst->extension);
1836        }
1837
1838        return ret;
1839}
1840
1841int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1842{
1843        int err;
1844        struct p9_req_t *req;
1845        struct p9_client *clnt;
1846
1847        err = 0;
1848        clnt = fid->clnt;
1849        wst->size = p9_client_statsize(wst, clnt->proto_version);
1850        p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1851        p9_debug(P9_DEBUG_9P,
1852                "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1853                "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1854                "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1855                "     uid=%d gid=%d n_muid=%d\n",
1856                wst->size, wst->type, wst->dev, wst->qid.type,
1857                (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1858                wst->atime, wst->mtime, (unsigned long long)wst->length,
1859                wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1860                from_kuid(&init_user_ns, wst->n_uid),
1861                from_kgid(&init_user_ns, wst->n_gid),
1862                from_kuid(&init_user_ns, wst->n_muid));
1863
1864        req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1865        if (IS_ERR(req)) {
1866                err = PTR_ERR(req);
1867                goto error;
1868        }
1869
1870        p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1871
1872        p9_tag_remove(clnt, req);
1873error:
1874        return err;
1875}
1876EXPORT_SYMBOL(p9_client_wstat);
1877
1878int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1879{
1880        int err;
1881        struct p9_req_t *req;
1882        struct p9_client *clnt;
1883
1884        err = 0;
1885        clnt = fid->clnt;
1886        p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1887        p9_debug(P9_DEBUG_9P,
1888                "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1889                "    atime_sec=%lld atime_nsec=%lld\n"
1890                "    mtime_sec=%lld mtime_nsec=%lld\n",
1891                p9attr->valid, p9attr->mode,
1892                from_kuid(&init_user_ns, p9attr->uid),
1893                from_kgid(&init_user_ns, p9attr->gid),
1894                p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1895                p9attr->mtime_sec, p9attr->mtime_nsec);
1896
1897        req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1898
1899        if (IS_ERR(req)) {
1900                err = PTR_ERR(req);
1901                goto error;
1902        }
1903        p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1904        p9_tag_remove(clnt, req);
1905error:
1906        return err;
1907}
1908EXPORT_SYMBOL(p9_client_setattr);
1909
1910int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1911{
1912        int err;
1913        struct p9_req_t *req;
1914        struct p9_client *clnt;
1915
1916        err = 0;
1917        clnt = fid->clnt;
1918
1919        p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1920
1921        req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1922        if (IS_ERR(req)) {
1923                err = PTR_ERR(req);
1924                goto error;
1925        }
1926
1927        err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1928                          &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1929                          &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1930        if (err) {
1931                trace_9p_protocol_dump(clnt, &req->rc);
1932                p9_tag_remove(clnt, req);
1933                goto error;
1934        }
1935
1936        p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1937                "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1938                "fsid %llu namelen %ld\n",
1939                fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1940                sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1941                sb->fsid, (long int)sb->namelen);
1942
1943        p9_tag_remove(clnt, req);
1944error:
1945        return err;
1946}
1947EXPORT_SYMBOL(p9_client_statfs);
1948
1949int p9_client_rename(struct p9_fid *fid,
1950                     struct p9_fid *newdirfid, const char *name)
1951{
1952        int err;
1953        struct p9_req_t *req;
1954        struct p9_client *clnt;
1955
1956        err = 0;
1957        clnt = fid->clnt;
1958
1959        p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1960                        fid->fid, newdirfid->fid, name);
1961
1962        req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1963                        newdirfid->fid, name);
1964        if (IS_ERR(req)) {
1965                err = PTR_ERR(req);
1966                goto error;
1967        }
1968
1969        p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1970
1971        p9_tag_remove(clnt, req);
1972error:
1973        return err;
1974}
1975EXPORT_SYMBOL(p9_client_rename);
1976
1977int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1978                       struct p9_fid *newdirfid, const char *new_name)
1979{
1980        int err;
1981        struct p9_req_t *req;
1982        struct p9_client *clnt;
1983
1984        err = 0;
1985        clnt = olddirfid->clnt;
1986
1987        p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1988                   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1989                   newdirfid->fid, new_name);
1990
1991        req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1992                            old_name, newdirfid->fid, new_name);
1993        if (IS_ERR(req)) {
1994                err = PTR_ERR(req);
1995                goto error;
1996        }
1997
1998        p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1999                   newdirfid->fid, new_name);
2000
2001        p9_tag_remove(clnt, req);
2002error:
2003        return err;
2004}
2005EXPORT_SYMBOL(p9_client_renameat);
2006
2007/*
2008 * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2009 */
2010struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2011                                const char *attr_name, u64 *attr_size)
2012{
2013        int err;
2014        struct p9_req_t *req;
2015        struct p9_client *clnt;
2016        struct p9_fid *attr_fid;
2017
2018        err = 0;
2019        clnt = file_fid->clnt;
2020        attr_fid = p9_fid_create(clnt);
2021        if (!attr_fid) {
2022                err = -ENOMEM;
2023                goto error;
2024        }
2025        p9_debug(P9_DEBUG_9P,
2026                ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2027                file_fid->fid, attr_fid->fid, attr_name);
2028
2029        req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2030                        file_fid->fid, attr_fid->fid, attr_name);
2031        if (IS_ERR(req)) {
2032                err = PTR_ERR(req);
2033                goto error;
2034        }
2035        err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
2036        if (err) {
2037                trace_9p_protocol_dump(clnt, &req->rc);
2038                p9_tag_remove(clnt, req);
2039                goto clunk_fid;
2040        }
2041        p9_tag_remove(clnt, req);
2042        p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2043                attr_fid->fid, *attr_size);
2044        return attr_fid;
2045clunk_fid:
2046        p9_client_clunk(attr_fid);
2047        attr_fid = NULL;
2048error:
2049        if (attr_fid && (attr_fid != file_fid))
2050                p9_fid_destroy(attr_fid);
2051
2052        return ERR_PTR(err);
2053}
2054EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2055
2056int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2057                        u64 attr_size, int flags)
2058{
2059        int err;
2060        struct p9_req_t *req;
2061        struct p9_client *clnt;
2062
2063        p9_debug(P9_DEBUG_9P,
2064                ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2065                fid->fid, name, (long long)attr_size, flags);
2066        err = 0;
2067        clnt = fid->clnt;
2068        req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2069                        fid->fid, name, attr_size, flags);
2070        if (IS_ERR(req)) {
2071                err = PTR_ERR(req);
2072                goto error;
2073        }
2074        p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2075        p9_tag_remove(clnt, req);
2076error:
2077        return err;
2078}
2079EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2080
2081int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2082{
2083        int err, rsize, non_zc = 0;
2084        struct p9_client *clnt;
2085        struct p9_req_t *req;
2086        char *dataptr;
2087        struct kvec kv = {.iov_base = data, .iov_len = count};
2088        struct iov_iter to;
2089
2090        iov_iter_kvec(&to, READ, &kv, 1, count);
2091
2092        p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2093                                fid->fid, (unsigned long long) offset, count);
2094
2095        err = 0;
2096        clnt = fid->clnt;
2097
2098        rsize = fid->iounit;
2099        if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2100                rsize = clnt->msize - P9_READDIRHDRSZ;
2101
2102        if (count < rsize)
2103                rsize = count;
2104
2105        /* Don't bother zerocopy for small IO (< 1024) */
2106        if (clnt->trans_mod->zc_request && rsize > 1024) {
2107                /*
2108                 * response header len is 11
2109                 * PDU Header(7) + IO Size (4)
2110                 */
2111                req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2112                                       11, "dqd", fid->fid, offset, rsize);
2113        } else {
2114                non_zc = 1;
2115                req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2116                                    offset, rsize);
2117        }
2118        if (IS_ERR(req)) {
2119                err = PTR_ERR(req);
2120                goto error;
2121        }
2122
2123        err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
2124        if (err) {
2125                trace_9p_protocol_dump(clnt, &req->rc);
2126                goto free_and_error;
2127        }
2128        if (rsize < count) {
2129                pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2130                count = rsize;
2131        }
2132
2133        p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2134
2135        if (non_zc)
2136                memmove(data, dataptr, count);
2137
2138        p9_tag_remove(clnt, req);
2139        return count;
2140
2141free_and_error:
2142        p9_tag_remove(clnt, req);
2143error:
2144        return err;
2145}
2146EXPORT_SYMBOL(p9_client_readdir);
2147
2148int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2149                        dev_t rdev, kgid_t gid, struct p9_qid *qid)
2150{
2151        int err;
2152        struct p9_client *clnt;
2153        struct p9_req_t *req;
2154
2155        err = 0;
2156        clnt = fid->clnt;
2157        p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2158                "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2159        req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2160                MAJOR(rdev), MINOR(rdev), gid);
2161        if (IS_ERR(req))
2162                return PTR_ERR(req);
2163
2164        err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2165        if (err) {
2166                trace_9p_protocol_dump(clnt, &req->rc);
2167                goto error;
2168        }
2169        p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2170                                (unsigned long long)qid->path, qid->version);
2171
2172error:
2173        p9_tag_remove(clnt, req);
2174        return err;
2175
2176}
2177EXPORT_SYMBOL(p9_client_mknod_dotl);
2178
2179int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2180                                kgid_t gid, struct p9_qid *qid)
2181{
2182        int err;
2183        struct p9_client *clnt;
2184        struct p9_req_t *req;
2185
2186        err = 0;
2187        clnt = fid->clnt;
2188        p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2189                 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2190        req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2191                gid);
2192        if (IS_ERR(req))
2193                return PTR_ERR(req);
2194
2195        err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2196        if (err) {
2197                trace_9p_protocol_dump(clnt, &req->rc);
2198                goto error;
2199        }
2200        p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2201                                (unsigned long long)qid->path, qid->version);
2202
2203error:
2204        p9_tag_remove(clnt, req);
2205        return err;
2206
2207}
2208EXPORT_SYMBOL(p9_client_mkdir_dotl);
2209
2210int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2211{
2212        int err;
2213        struct p9_client *clnt;
2214        struct p9_req_t *req;
2215
2216        err = 0;
2217        clnt = fid->clnt;
2218        p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2219                        "start %lld length %lld proc_id %d client_id %s\n",
2220                        fid->fid, flock->type, flock->flags, flock->start,
2221                        flock->length, flock->proc_id, flock->client_id);
2222
2223        req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2224                                flock->flags, flock->start, flock->length,
2225                                        flock->proc_id, flock->client_id);
2226
2227        if (IS_ERR(req))
2228                return PTR_ERR(req);
2229
2230        err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
2231        if (err) {
2232                trace_9p_protocol_dump(clnt, &req->rc);
2233                goto error;
2234        }
2235        p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2236error:
2237        p9_tag_remove(clnt, req);
2238        return err;
2239
2240}
2241EXPORT_SYMBOL(p9_client_lock_dotl);
2242
2243int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2244{
2245        int err;
2246        struct p9_client *clnt;
2247        struct p9_req_t *req;
2248
2249        err = 0;
2250        clnt = fid->clnt;
2251        p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2252                "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2253                glock->start, glock->length, glock->proc_id, glock->client_id);
2254
2255        req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2256                glock->start, glock->length, glock->proc_id, glock->client_id);
2257
2258        if (IS_ERR(req))
2259                return PTR_ERR(req);
2260
2261        err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type,
2262                          &glock->start, &glock->length, &glock->proc_id,
2263                          &glock->client_id);
2264        if (err) {
2265                trace_9p_protocol_dump(clnt, &req->rc);
2266                goto error;
2267        }
2268        p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2269                "proc_id %d client_id %s\n", glock->type, glock->start,
2270                glock->length, glock->proc_id, glock->client_id);
2271error:
2272        p9_tag_remove(clnt, req);
2273        return err;
2274}
2275EXPORT_SYMBOL(p9_client_getlock_dotl);
2276
2277int p9_client_readlink(struct p9_fid *fid, char **target)
2278{
2279        int err;
2280        struct p9_client *clnt;
2281        struct p9_req_t *req;
2282
2283        err = 0;
2284        clnt = fid->clnt;
2285        p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2286
2287        req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2288        if (IS_ERR(req))
2289                return PTR_ERR(req);
2290
2291        err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
2292        if (err) {
2293                trace_9p_protocol_dump(clnt, &req->rc);
2294                goto error;
2295        }
2296        p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2297error:
2298        p9_tag_remove(clnt, req);
2299        return err;
2300}
2301EXPORT_SYMBOL(p9_client_readlink);
2302
2303int __init p9_client_init(void)
2304{
2305        p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU);
2306        return p9_req_cache ? 0 : -ENOMEM;
2307}
2308
2309void __exit p9_client_exit(void)
2310{
2311        kmem_cache_destroy(p9_req_cache);
2312}
2313