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}