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v4.6
 
   1/*
   2 * net/9p/clnt.c
   3 *
   4 * 9P Client
   5 *
   6 *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7 *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8 *
   9 *  This program is free software; you can redistribute it and/or modify
  10 *  it under the terms of the GNU General Public License version 2
  11 *  as published by the Free Software Foundation.
  12 *
  13 *  This program is distributed in the hope that it will be useful,
  14 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 *  GNU General Public License for more details.
  17 *
  18 *  You should have received a copy of the GNU General Public License
  19 *  along with this program; if not, write to:
  20 *  Free Software Foundation
  21 *  51 Franklin Street, Fifth Floor
  22 *  Boston, MA  02111-1301  USA
  23 *
  24 */
  25
  26#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28#include <linux/module.h>
  29#include <linux/errno.h>
  30#include <linux/fs.h>
  31#include <linux/poll.h>
  32#include <linux/idr.h>
  33#include <linux/mutex.h>
  34#include <linux/slab.h>
  35#include <linux/sched.h>
  36#include <linux/uaccess.h>
  37#include <linux/uio.h>
  38#include <net/9p/9p.h>
  39#include <linux/parser.h>
 
  40#include <net/9p/client.h>
  41#include <net/9p/transport.h>
  42#include "protocol.h"
  43
  44#define CREATE_TRACE_POINTS
  45#include <trace/events/9p.h>
  46
  47/*
  48  * Client Option Parsing (code inspired by NFS code)
  49  *  - a little lazy - parse all client options
  50  */
  51
  52enum {
  53	Opt_msize,
  54	Opt_trans,
  55	Opt_legacy,
  56	Opt_version,
  57	Opt_err,
  58};
  59
  60static const match_table_t tokens = {
  61	{Opt_msize, "msize=%u"},
  62	{Opt_legacy, "noextend"},
  63	{Opt_trans, "trans=%s"},
  64	{Opt_version, "version=%s"},
  65	{Opt_err, NULL},
  66};
  67
  68inline int p9_is_proto_dotl(struct p9_client *clnt)
  69{
  70	return clnt->proto_version == p9_proto_2000L;
  71}
  72EXPORT_SYMBOL(p9_is_proto_dotl);
  73
  74inline int p9_is_proto_dotu(struct p9_client *clnt)
  75{
  76	return clnt->proto_version == p9_proto_2000u;
  77}
  78EXPORT_SYMBOL(p9_is_proto_dotu);
  79
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  80/*
  81 * Some error codes are taken directly from the server replies,
  82 * make sure they are valid.
  83 */
  84static int safe_errno(int err)
  85{
  86	if ((err > 0) || (err < -MAX_ERRNO)) {
  87		p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
  88		return -EPROTO;
  89	}
  90	return err;
  91}
  92
  93
  94/* Interpret mount option for protocol version */
  95static int get_protocol_version(char *s)
  96{
  97	int version = -EINVAL;
  98
  99	if (!strcmp(s, "9p2000")) {
 100		version = p9_proto_legacy;
 101		p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
 102	} else if (!strcmp(s, "9p2000.u")) {
 103		version = p9_proto_2000u;
 104		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
 105	} else if (!strcmp(s, "9p2000.L")) {
 106		version = p9_proto_2000L;
 107		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
 108	} else
 109		pr_info("Unknown protocol version %s\n", s);
 110
 111	return version;
 112}
 113
 114/**
 115 * parse_options - parse mount options into client structure
 116 * @opts: options string passed from mount
 117 * @clnt: existing v9fs client information
 118 *
 119 * Return 0 upon success, -ERRNO upon failure
 120 */
 121
 122static int parse_opts(char *opts, struct p9_client *clnt)
 123{
 124	char *options, *tmp_options;
 125	char *p;
 126	substring_t args[MAX_OPT_ARGS];
 127	int option;
 128	char *s;
 129	int ret = 0;
 130
 131	clnt->proto_version = p9_proto_2000L;
 132	clnt->msize = 8192;
 133
 134	if (!opts)
 135		return 0;
 136
 137	tmp_options = kstrdup(opts, GFP_KERNEL);
 138	if (!tmp_options) {
 139		p9_debug(P9_DEBUG_ERROR,
 140			 "failed to allocate copy of option string\n");
 141		return -ENOMEM;
 142	}
 143	options = tmp_options;
 144
 145	while ((p = strsep(&options, ",")) != NULL) {
 146		int token, r;
 147		if (!*p)
 148			continue;
 149		token = match_token(p, tokens, args);
 150		switch (token) {
 151		case Opt_msize:
 152			r = match_int(&args[0], &option);
 153			if (r < 0) {
 154				p9_debug(P9_DEBUG_ERROR,
 155					 "integer field, but no integer?\n");
 156				ret = r;
 157				continue;
 158			}
 
 
 
 
 
 
 159			clnt->msize = option;
 160			break;
 161		case Opt_trans:
 162			s = match_strdup(&args[0]);
 163			if (!s) {
 164				ret = -ENOMEM;
 165				p9_debug(P9_DEBUG_ERROR,
 166					 "problem allocating copy of trans arg\n");
 167				goto free_and_return;
 168			 }
 
 
 169			clnt->trans_mod = v9fs_get_trans_by_name(s);
 170			if (clnt->trans_mod == NULL) {
 171				pr_info("Could not find request transport: %s\n",
 172					s);
 173				ret = -EINVAL;
 174				kfree(s);
 175				goto free_and_return;
 176			}
 177			kfree(s);
 178			break;
 179		case Opt_legacy:
 180			clnt->proto_version = p9_proto_legacy;
 181			break;
 182		case Opt_version:
 183			s = match_strdup(&args[0]);
 184			if (!s) {
 185				ret = -ENOMEM;
 186				p9_debug(P9_DEBUG_ERROR,
 187					 "problem allocating copy of version arg\n");
 188				goto free_and_return;
 189			}
 190			ret = get_protocol_version(s);
 191			if (ret == -EINVAL) {
 192				kfree(s);
 193				goto free_and_return;
 194			}
 195			kfree(s);
 196			clnt->proto_version = ret;
 197			break;
 198		default:
 199			continue;
 200		}
 201	}
 202
 203free_and_return:
 
 
 204	kfree(tmp_options);
 205	return ret;
 206}
 207
 208static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
 
 209{
 210	struct p9_fcall *fc;
 211	fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
 212	if (!fc)
 213		return NULL;
 
 
 
 
 
 214	fc->capacity = alloc_msize;
 215	fc->sdata = (char *) fc + sizeof(struct p9_fcall);
 216	return fc;
 217}
 218
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 219/**
 220 * p9_tag_alloc - lookup/allocate a request by tag
 221 * @c: client session to lookup tag within
 222 * @tag: numeric id for transaction
 223 *
 224 * this is a simple array lookup, but will grow the
 225 * request_slots as necessary to accommodate transaction
 226 * ids which did not previously have a slot.
 227 *
 228 * this code relies on the client spinlock to manage locks, its
 229 * possible we should switch to something else, but I'd rather
 230 * stick with something low-overhead for the common case.
 231 *
 
 
 232 */
 233
 234static struct p9_req_t *
 235p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
 236{
 237	unsigned long flags;
 238	int row, col;
 239	struct p9_req_t *req;
 240	int alloc_msize = min(c->msize, max_size);
 
 241
 242	/* This looks up the original request by tag so we know which
 243	 * buffer to read the data into */
 244	tag++;
 245
 246	if (tag >= c->max_tag) {
 247		spin_lock_irqsave(&c->lock, flags);
 248		/* check again since original check was outside of lock */
 249		while (tag >= c->max_tag) {
 250			row = (tag / P9_ROW_MAXTAG);
 251			c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 252					sizeof(struct p9_req_t), GFP_ATOMIC);
 253
 254			if (!c->reqs[row]) {
 255				pr_err("Couldn't grow tag array\n");
 256				spin_unlock_irqrestore(&c->lock, flags);
 257				return ERR_PTR(-ENOMEM);
 258			}
 259			for (col = 0; col < P9_ROW_MAXTAG; col++) {
 260				c->reqs[row][col].status = REQ_STATUS_IDLE;
 261				c->reqs[row][col].tc = NULL;
 262			}
 263			c->max_tag += P9_ROW_MAXTAG;
 264		}
 265		spin_unlock_irqrestore(&c->lock, flags);
 266	}
 267	row = tag / P9_ROW_MAXTAG;
 268	col = tag % P9_ROW_MAXTAG;
 269
 270	req = &c->reqs[row][col];
 271	if (!req->wq) {
 272		req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
 273		if (!req->wq)
 274			goto grow_failed;
 275		init_waitqueue_head(req->wq);
 276	}
 277
 278	if (!req->tc)
 279		req->tc = p9_fcall_alloc(alloc_msize);
 280	if (!req->rc)
 281		req->rc = p9_fcall_alloc(alloc_msize);
 282	if (!req->tc || !req->rc)
 283		goto grow_failed;
 284
 285	p9pdu_reset(req->tc);
 286	p9pdu_reset(req->rc);
 287
 288	req->tc->tag = tag-1;
 
 
 
 
 
 
 
 289	req->status = REQ_STATUS_ALLOC;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 290
 291	return req;
 292
 293grow_failed:
 294	pr_err("Couldn't grow tag array\n");
 295	kfree(req->tc);
 296	kfree(req->rc);
 297	kfree(req->wq);
 298	req->tc = req->rc = NULL;
 299	req->wq = NULL;
 300	return ERR_PTR(-ENOMEM);
 301}
 302
 303/**
 304 * p9_tag_lookup - lookup a request by tag
 305 * @c: client session to lookup tag within
 306 * @tag: numeric id for transaction
 307 *
 
 
 308 */
 309
 310struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 311{
 312	int row, col;
 313
 314	/* This looks up the original request by tag so we know which
 315	 * buffer to read the data into */
 316	tag++;
 317
 318	if(tag >= c->max_tag) 
 319		return NULL;
 320
 321	row = tag / P9_ROW_MAXTAG;
 322	col = tag % P9_ROW_MAXTAG;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 323
 324	return &c->reqs[row][col];
 325}
 326EXPORT_SYMBOL(p9_tag_lookup);
 327
 328/**
 329 * p9_tag_init - setup tags structure and contents
 330 * @c:  v9fs client struct
 331 *
 332 * This initializes the tags structure for each client instance.
 333 *
 
 334 */
 
 
 
 
 
 
 
 
 
 
 
 335
 336static int p9_tag_init(struct p9_client *c)
 337{
 338	int err = 0;
 
 
 
 
 339
 340	c->tagpool = p9_idpool_create();
 341	if (IS_ERR(c->tagpool)) {
 342		err = PTR_ERR(c->tagpool);
 343		goto error;
 344	}
 345	err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
 346	if (err < 0) {
 347		p9_idpool_destroy(c->tagpool);
 348		goto error;
 349	}
 350	c->max_tag = 0;
 351error:
 352	return err;
 353}
 
 354
 355/**
 356 * p9_tag_cleanup - cleans up tags structure and reclaims resources
 357 * @c:  v9fs client struct
 358 *
 359 * This frees resources associated with the tags structure
 360 *
 361 */
 362static void p9_tag_cleanup(struct p9_client *c)
 363{
 364	int row, col;
 365
 366	/* check to insure all requests are idle */
 367	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 368		for (col = 0; col < P9_ROW_MAXTAG; col++) {
 369			if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 370				p9_debug(P9_DEBUG_MUX,
 371					 "Attempting to cleanup non-free tag %d,%d\n",
 372					 row, col);
 373				/* TODO: delay execution of cleanup */
 374				return;
 375			}
 376		}
 377	}
 378
 379	if (c->tagpool) {
 380		p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
 381		p9_idpool_destroy(c->tagpool);
 382	}
 383
 384	/* free requests associated with tags */
 385	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 386		for (col = 0; col < P9_ROW_MAXTAG; col++) {
 387			kfree(c->reqs[row][col].wq);
 388			kfree(c->reqs[row][col].tc);
 389			kfree(c->reqs[row][col].rc);
 390		}
 391		kfree(c->reqs[row]);
 392	}
 393	c->max_tag = 0;
 394}
 395
 396/**
 397 * p9_free_req - free a request and clean-up as necessary
 398 * c: client state
 399 * r: request to release
 400 *
 401 */
 402
 403static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 404{
 405	int tag = r->tc->tag;
 406	p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 407
 408	r->status = REQ_STATUS_IDLE;
 409	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 410		p9_idpool_put(tag, c->tagpool);
 411}
 412
 413/**
 414 * p9_client_cb - call back from transport to client
 415 * c: client state
 416 * req: request received
 417 *
 418 */
 419void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 420{
 421	p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 422
 423	/*
 424	 * This barrier is needed to make sure any change made to req before
 425	 * the other thread wakes up will indeed be seen by the waiting side.
 426	 */
 427	smp_wmb();
 428	req->status = status;
 429
 430	wake_up(req->wq);
 431	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 
 432}
 433EXPORT_SYMBOL(p9_client_cb);
 434
 435/**
 436 * p9_parse_header - parse header arguments out of a packet
 437 * @pdu: packet to parse
 438 * @size: size of packet
 439 * @type: type of request
 440 * @tag: tag of packet
 441 * @rewind: set if we need to rewind offset afterwards
 442 */
 443
 444int
 445p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 446								int rewind)
 447{
 448	int8_t r_type;
 449	int16_t r_tag;
 450	int32_t r_size;
 451	int offset = pdu->offset;
 452	int err;
 453
 454	pdu->offset = 0;
 455	if (pdu->size == 0)
 456		pdu->size = 7;
 457
 458	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 459	if (err)
 460		goto rewind_and_exit;
 461
 462	pdu->size = r_size;
 463	pdu->id = r_type;
 464	pdu->tag = r_tag;
 465
 466	p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 467		 pdu->size, pdu->id, pdu->tag);
 468
 469	if (type)
 470		*type = r_type;
 471	if (tag)
 472		*tag = r_tag;
 473	if (size)
 474		*size = r_size;
 475
 
 
 
 
 
 
 
 
 
 
 476
 477rewind_and_exit:
 478	if (rewind)
 479		pdu->offset = offset;
 480	return err;
 481}
 482EXPORT_SYMBOL(p9_parse_header);
 483
 484/**
 485 * p9_check_errors - check 9p packet for error return and process it
 486 * @c: current client instance
 487 * @req: request to parse and check for error conditions
 488 *
 489 * returns error code if one is discovered, otherwise returns 0
 490 *
 491 * this will have to be more complicated if we have multiple
 492 * error packet types
 493 */
 494
 495static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 496{
 497	int8_t type;
 498	int err;
 499	int ecode;
 500
 501	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 
 
 
 
 
 
 502	/*
 503	 * dump the response from server
 504	 * This should be after check errors which poplulate pdu_fcall.
 505	 */
 506	trace_9p_protocol_dump(c, req->rc);
 507	if (err) {
 508		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 509		return err;
 510	}
 511	if (type != P9_RERROR && type != P9_RLERROR)
 512		return 0;
 513
 514	if (!p9_is_proto_dotl(c)) {
 515		char *ename;
 516		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 517				  &ename, &ecode);
 518		if (err)
 519			goto out_err;
 520
 521		if (p9_is_proto_dotu(c))
 522			err = -ecode;
 523
 524		if (!err || !IS_ERR_VALUE(err)) {
 525			err = p9_errstr2errno(ename, strlen(ename));
 526
 527			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 528				 -ecode, ename);
 529		}
 530		kfree(ename);
 531	} else {
 532		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 533		err = -ecode;
 534
 535		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 536	}
 537
 538	return err;
 539
 540out_err:
 541	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 542
 543	return err;
 544}
 545
 546/**
 547 * p9_check_zc_errors - check 9p packet for error return and process it
 548 * @c: current client instance
 549 * @req: request to parse and check for error conditions
 550 * @in_hdrlen: Size of response protocol buffer.
 551 *
 552 * returns error code if one is discovered, otherwise returns 0
 553 *
 554 * this will have to be more complicated if we have multiple
 555 * error packet types
 556 */
 557
 558static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 559			      struct iov_iter *uidata, int in_hdrlen)
 560{
 561	int err;
 562	int ecode;
 563	int8_t type;
 564	char *ename = NULL;
 565
 566	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 567	/*
 568	 * dump the response from server
 569	 * This should be after parse_header which poplulate pdu_fcall.
 570	 */
 571	trace_9p_protocol_dump(c, req->rc);
 572	if (err) {
 573		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 574		return err;
 575	}
 576
 577	if (type != P9_RERROR && type != P9_RLERROR)
 578		return 0;
 579
 580	if (!p9_is_proto_dotl(c)) {
 581		/* Error is reported in string format */
 582		int len;
 583		/* 7 = header size for RERROR; */
 584		int inline_len = in_hdrlen - 7;
 585
 586		len =  req->rc->size - req->rc->offset;
 587		if (len > (P9_ZC_HDR_SZ - 7)) {
 588			err = -EFAULT;
 589			goto out_err;
 590		}
 591
 592		ename = &req->rc->sdata[req->rc->offset];
 593		if (len > inline_len) {
 594			/* We have error in external buffer */
 595			err = copy_from_iter(ename + inline_len,
 596					     len - inline_len, uidata);
 597			if (err != len - inline_len) {
 598				err = -EFAULT;
 599				goto out_err;
 600			}
 601		}
 602		ename = NULL;
 603		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
 604				  &ename, &ecode);
 605		if (err)
 606			goto out_err;
 607
 608		if (p9_is_proto_dotu(c))
 609			err = -ecode;
 610
 611		if (!err || !IS_ERR_VALUE(err)) {
 612			err = p9_errstr2errno(ename, strlen(ename));
 613
 614			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 615				 -ecode, ename);
 616		}
 617		kfree(ename);
 618	} else {
 619		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
 620		err = -ecode;
 621
 622		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 623	}
 624	return err;
 625
 626out_err:
 627	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 628	return err;
 629}
 630
 631static struct p9_req_t *
 632p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 633
 634/**
 635 * p9_client_flush - flush (cancel) a request
 636 * @c: client state
 637 * @oldreq: request to cancel
 638 *
 639 * This sents a flush for a particular request and links
 640 * the flush request to the original request.  The current
 641 * code only supports a single flush request although the protocol
 642 * allows for multiple flush requests to be sent for a single request.
 643 *
 644 */
 645
 646static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 647{
 648	struct p9_req_t *req;
 649	int16_t oldtag;
 650	int err;
 651
 652	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 653	if (err)
 654		return err;
 655
 656	p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 657
 658	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 659	if (IS_ERR(req))
 660		return PTR_ERR(req);
 661
 662	/*
 663	 * if we haven't received a response for oldreq,
 664	 * remove it from the list
 665	 */
 666	if (oldreq->status == REQ_STATUS_SENT)
 667		if (c->trans_mod->cancelled)
 668			c->trans_mod->cancelled(c, oldreq);
 
 669
 670	p9_free_req(c, req);
 671	return 0;
 672}
 673
 674static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 675					      int8_t type, int req_size,
 676					      const char *fmt, va_list ap)
 677{
 678	int tag, err;
 679	struct p9_req_t *req;
 680
 681	p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 682
 683	/* we allow for any status other than disconnected */
 684	if (c->status == Disconnected)
 685		return ERR_PTR(-EIO);
 686
 687	/* if status is begin_disconnected we allow only clunk request */
 688	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 689		return ERR_PTR(-EIO);
 690
 691	tag = P9_NOTAG;
 692	if (type != P9_TVERSION) {
 693		tag = p9_idpool_get(c->tagpool);
 694		if (tag < 0)
 695			return ERR_PTR(-ENOMEM);
 696	}
 697
 698	req = p9_tag_alloc(c, tag, req_size);
 699	if (IS_ERR(req))
 700		return req;
 701
 702	/* marshall the data */
 703	p9pdu_prepare(req->tc, tag, type);
 704	err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
 705	if (err)
 706		goto reterr;
 707	p9pdu_finalize(c, req->tc);
 708	trace_9p_client_req(c, type, tag);
 709	return req;
 710reterr:
 711	p9_free_req(c, req);
 
 
 712	return ERR_PTR(err);
 713}
 714
 715/**
 716 * p9_client_rpc - issue a request and wait for a response
 717 * @c: client session
 718 * @type: type of request
 719 * @fmt: protocol format string (see protocol.c)
 720 *
 721 * Returns request structure (which client must free using p9_free_req)
 722 */
 723
 724static struct p9_req_t *
 725p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 726{
 727	va_list ap;
 728	int sigpending, err;
 729	unsigned long flags;
 730	struct p9_req_t *req;
 731
 732	va_start(ap, fmt);
 733	req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 734	va_end(ap);
 735	if (IS_ERR(req))
 736		return req;
 737
 738	if (signal_pending(current)) {
 739		sigpending = 1;
 740		clear_thread_flag(TIF_SIGPENDING);
 741	} else
 742		sigpending = 0;
 743
 744	err = c->trans_mod->request(c, req);
 745	if (err < 0) {
 
 
 746		if (err != -ERESTARTSYS && err != -EFAULT)
 747			c->status = Disconnected;
 748		goto reterr;
 749	}
 750again:
 751	/* Wait for the response */
 752	err = wait_event_interruptible(*req->wq,
 753				       req->status >= REQ_STATUS_RCVD);
 754
 755	/*
 756	 * Make sure our req is coherent with regard to updates in other
 757	 * threads - echoes to wmb() in the callback
 758	 */
 759	smp_rmb();
 760
 761	if ((err == -ERESTARTSYS) && (c->status == Connected)
 762				  && (type == P9_TFLUSH)) {
 763		sigpending = 1;
 764		clear_thread_flag(TIF_SIGPENDING);
 765		goto again;
 766	}
 767
 768	if (req->status == REQ_STATUS_ERROR) {
 769		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 770		err = req->t_err;
 771	}
 772	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 773		p9_debug(P9_DEBUG_MUX, "flushing\n");
 774		sigpending = 1;
 775		clear_thread_flag(TIF_SIGPENDING);
 776
 777		if (c->trans_mod->cancel(c, req))
 778			p9_client_flush(c, req);
 779
 780		/* if we received the response anyway, don't signal error */
 781		if (req->status == REQ_STATUS_RCVD)
 782			err = 0;
 783	}
 
 784	if (sigpending) {
 785		spin_lock_irqsave(&current->sighand->siglock, flags);
 786		recalc_sigpending();
 787		spin_unlock_irqrestore(&current->sighand->siglock, flags);
 788	}
 789	if (err < 0)
 790		goto reterr;
 791
 792	err = p9_check_errors(c, req);
 793	trace_9p_client_res(c, type, req->rc->tag, err);
 794	if (!err)
 795		return req;
 796reterr:
 797	p9_free_req(c, req);
 798	return ERR_PTR(safe_errno(err));
 799}
 800
 801/**
 802 * p9_client_zc_rpc - issue a request and wait for a response
 803 * @c: client session
 804 * @type: type of request
 805 * @uidata: destination for zero copy read
 806 * @uodata: source for zero copy write
 807 * @inlen: read buffer size
 808 * @olen: write buffer size
 809 * @hdrlen: reader header size, This is the size of response protocol data
 810 * @fmt: protocol format string (see protocol.c)
 811 *
 812 * Returns request structure (which client must free using p9_free_req)
 813 */
 814static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 815					 struct iov_iter *uidata,
 816					 struct iov_iter *uodata,
 817					 int inlen, int olen, int in_hdrlen,
 818					 const char *fmt, ...)
 819{
 820	va_list ap;
 821	int sigpending, err;
 822	unsigned long flags;
 823	struct p9_req_t *req;
 824
 825	va_start(ap, fmt);
 826	/*
 827	 * We allocate a inline protocol data of only 4k bytes.
 828	 * The actual content is passed in zero-copy fashion.
 829	 */
 830	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 831	va_end(ap);
 832	if (IS_ERR(req))
 833		return req;
 834
 835	if (signal_pending(current)) {
 836		sigpending = 1;
 837		clear_thread_flag(TIF_SIGPENDING);
 838	} else
 839		sigpending = 0;
 840
 841	err = c->trans_mod->zc_request(c, req, uidata, uodata,
 842				       inlen, olen, in_hdrlen);
 843	if (err < 0) {
 844		if (err == -EIO)
 845			c->status = Disconnected;
 846		if (err != -ERESTARTSYS)
 847			goto reterr;
 848	}
 849	if (req->status == REQ_STATUS_ERROR) {
 850		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 851		err = req->t_err;
 852	}
 853	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 854		p9_debug(P9_DEBUG_MUX, "flushing\n");
 855		sigpending = 1;
 856		clear_thread_flag(TIF_SIGPENDING);
 857
 858		if (c->trans_mod->cancel(c, req))
 859			p9_client_flush(c, req);
 860
 861		/* if we received the response anyway, don't signal error */
 862		if (req->status == REQ_STATUS_RCVD)
 863			err = 0;
 864	}
 
 865	if (sigpending) {
 866		spin_lock_irqsave(&current->sighand->siglock, flags);
 867		recalc_sigpending();
 868		spin_unlock_irqrestore(&current->sighand->siglock, flags);
 869	}
 870	if (err < 0)
 871		goto reterr;
 872
 873	err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 874	trace_9p_client_res(c, type, req->rc->tag, err);
 875	if (!err)
 876		return req;
 877reterr:
 878	p9_free_req(c, req);
 879	return ERR_PTR(safe_errno(err));
 880}
 881
 882static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 883{
 884	int ret;
 885	struct p9_fid *fid;
 886	unsigned long flags;
 887
 888	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 889	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 890	if (!fid)
 891		return ERR_PTR(-ENOMEM);
 892
 893	ret = p9_idpool_get(clnt->fidpool);
 894	if (ret < 0) {
 895		ret = -ENOSPC;
 896		goto error;
 897	}
 898	fid->fid = ret;
 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	spin_lock_irqsave(&clnt->lock, flags);
 906	list_add(&fid->flist, &clnt->fidlist);
 907	spin_unlock_irqrestore(&clnt->lock, flags);
 908
 909	return fid;
 
 
 
 
 
 
 
 
 910
 911error:
 912	kfree(fid);
 913	return ERR_PTR(ret);
 914}
 915
 916static void p9_fid_destroy(struct p9_fid *fid)
 917{
 918	struct p9_client *clnt;
 919	unsigned long flags;
 920
 921	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 922	clnt = fid->clnt;
 923	p9_idpool_put(fid->fid, clnt->fidpool);
 924	spin_lock_irqsave(&clnt->lock, flags);
 925	list_del(&fid->flist);
 926	spin_unlock_irqrestore(&clnt->lock, flags);
 927	kfree(fid->rdir);
 928	kfree(fid);
 929}
 930
 931static int p9_client_version(struct p9_client *c)
 932{
 933	int err = 0;
 934	struct p9_req_t *req;
 935	char *version;
 936	int msize;
 937
 938	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 939		 c->msize, c->proto_version);
 940
 941	switch (c->proto_version) {
 942	case p9_proto_2000L:
 943		req = p9_client_rpc(c, P9_TVERSION, "ds",
 944					c->msize, "9P2000.L");
 945		break;
 946	case p9_proto_2000u:
 947		req = p9_client_rpc(c, P9_TVERSION, "ds",
 948					c->msize, "9P2000.u");
 949		break;
 950	case p9_proto_legacy:
 951		req = p9_client_rpc(c, P9_TVERSION, "ds",
 952					c->msize, "9P2000");
 953		break;
 954	default:
 955		return -EINVAL;
 956	}
 957
 958	if (IS_ERR(req))
 959		return PTR_ERR(req);
 960
 961	err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
 962	if (err) {
 963		p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 964		trace_9p_protocol_dump(c, req->rc);
 965		goto error;
 966	}
 967
 968	p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 969	if (!strncmp(version, "9P2000.L", 8))
 970		c->proto_version = p9_proto_2000L;
 971	else if (!strncmp(version, "9P2000.u", 8))
 972		c->proto_version = p9_proto_2000u;
 973	else if (!strncmp(version, "9P2000", 6))
 974		c->proto_version = p9_proto_legacy;
 975	else {
 
 
 976		err = -EREMOTEIO;
 977		goto error;
 978	}
 979
 
 
 
 
 
 
 980	if (msize < c->msize)
 981		c->msize = msize;
 982
 983error:
 984	kfree(version);
 985	p9_free_req(c, req);
 986
 987	return err;
 988}
 989
 990struct p9_client *p9_client_create(const char *dev_name, char *options)
 991{
 992	int err;
 993	struct p9_client *clnt;
 994	char *client_id;
 995
 996	err = 0;
 997	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 998	if (!clnt)
 999		return ERR_PTR(-ENOMEM);
1000
1001	clnt->trans_mod = NULL;
1002	clnt->trans = NULL;
 
1003
1004	client_id = utsname()->nodename;
1005	memcpy(clnt->name, client_id, strlen(client_id) + 1);
1006
1007	spin_lock_init(&clnt->lock);
1008	INIT_LIST_HEAD(&clnt->fidlist);
1009
1010	err = p9_tag_init(clnt);
1011	if (err < 0)
1012		goto free_client;
1013
1014	err = parse_opts(options, clnt);
1015	if (err < 0)
1016		goto destroy_tagpool;
1017
1018	if (!clnt->trans_mod)
1019		clnt->trans_mod = v9fs_get_default_trans();
1020
1021	if (clnt->trans_mod == NULL) {
1022		err = -EPROTONOSUPPORT;
1023		p9_debug(P9_DEBUG_ERROR,
1024			 "No transport defined or default transport\n");
1025		goto destroy_tagpool;
1026	}
1027
1028	clnt->fidpool = p9_idpool_create();
1029	if (IS_ERR(clnt->fidpool)) {
1030		err = PTR_ERR(clnt->fidpool);
1031		goto put_trans;
1032	}
1033
1034	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1035		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1036
1037	err = clnt->trans_mod->create(clnt, dev_name, options);
1038	if (err)
1039		goto destroy_fidpool;
1040
1041	if (clnt->msize > clnt->trans_mod->maxsize)
1042		clnt->msize = clnt->trans_mod->maxsize;
1043
 
 
 
 
 
 
 
1044	err = p9_client_version(clnt);
1045	if (err)
1046		goto close_trans;
1047
 
 
 
 
 
 
 
 
 
1048	return clnt;
1049
1050close_trans:
1051	clnt->trans_mod->close(clnt);
1052destroy_fidpool:
1053	p9_idpool_destroy(clnt->fidpool);
1054put_trans:
1055	v9fs_put_trans(clnt->trans_mod);
1056destroy_tagpool:
1057	p9_idpool_destroy(clnt->tagpool);
1058free_client:
1059	kfree(clnt);
1060	return ERR_PTR(err);
1061}
1062EXPORT_SYMBOL(p9_client_create);
1063
1064void p9_client_destroy(struct p9_client *clnt)
1065{
1066	struct p9_fid *fid, *fidptr;
 
1067
1068	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1069
1070	if (clnt->trans_mod)
1071		clnt->trans_mod->close(clnt);
1072
1073	v9fs_put_trans(clnt->trans_mod);
1074
1075	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1076		pr_info("Found fid %d not clunked\n", fid->fid);
1077		p9_fid_destroy(fid);
1078	}
1079
1080	if (clnt->fidpool)
1081		p9_idpool_destroy(clnt->fidpool);
1082
1083	p9_tag_cleanup(clnt);
1084
 
1085	kfree(clnt);
1086}
1087EXPORT_SYMBOL(p9_client_destroy);
1088
1089void p9_client_disconnect(struct p9_client *clnt)
1090{
1091	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1092	clnt->status = Disconnected;
1093}
1094EXPORT_SYMBOL(p9_client_disconnect);
1095
1096void p9_client_begin_disconnect(struct p9_client *clnt)
1097{
1098	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1099	clnt->status = BeginDisconnect;
1100}
1101EXPORT_SYMBOL(p9_client_begin_disconnect);
1102
1103struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1104	char *uname, kuid_t n_uname, char *aname)
1105{
1106	int err = 0;
1107	struct p9_req_t *req;
1108	struct p9_fid *fid;
1109	struct p9_qid qid;
1110
1111
1112	p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1113		 afid ? afid->fid : -1, uname, aname);
1114	fid = p9_fid_create(clnt);
1115	if (IS_ERR(fid)) {
1116		err = PTR_ERR(fid);
1117		fid = NULL;
1118		goto error;
1119	}
1120	fid->uid = n_uname;
1121
1122	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1123			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1124	if (IS_ERR(req)) {
1125		err = PTR_ERR(req);
1126		goto error;
1127	}
1128
1129	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1130	if (err) {
1131		trace_9p_protocol_dump(clnt, req->rc);
1132		p9_free_req(clnt, req);
1133		goto error;
1134	}
1135
1136	p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1137		 qid.type, (unsigned long long)qid.path, qid.version);
1138
1139	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1140
1141	p9_free_req(clnt, req);
1142	return fid;
1143
1144error:
1145	if (fid)
1146		p9_fid_destroy(fid);
1147	return ERR_PTR(err);
1148}
1149EXPORT_SYMBOL(p9_client_attach);
1150
1151struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1152		char **wnames, int clone)
1153{
1154	int err;
1155	struct p9_client *clnt;
1156	struct p9_fid *fid;
1157	struct p9_qid *wqids;
1158	struct p9_req_t *req;
1159	uint16_t nwqids, count;
1160
1161	err = 0;
1162	wqids = NULL;
1163	clnt = oldfid->clnt;
1164	if (clone) {
1165		fid = p9_fid_create(clnt);
1166		if (IS_ERR(fid)) {
1167			err = PTR_ERR(fid);
1168			fid = NULL;
1169			goto error;
1170		}
1171
1172		fid->uid = oldfid->uid;
1173	} else
1174		fid = oldfid;
1175
1176
1177	p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1178		 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1179
1180	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1181								nwname, wnames);
1182	if (IS_ERR(req)) {
1183		err = PTR_ERR(req);
1184		goto error;
1185	}
1186
1187	err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1188	if (err) {
1189		trace_9p_protocol_dump(clnt, req->rc);
1190		p9_free_req(clnt, req);
1191		goto clunk_fid;
1192	}
1193	p9_free_req(clnt, req);
1194
1195	p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1196
1197	if (nwqids != nwname) {
1198		err = -ENOENT;
1199		goto clunk_fid;
1200	}
1201
1202	for (count = 0; count < nwqids; count++)
1203		p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1204			count, wqids[count].type,
1205			(unsigned long long)wqids[count].path,
1206			wqids[count].version);
1207
1208	if (nwname)
1209		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1210	else
1211		fid->qid = oldfid->qid;
1212
1213	kfree(wqids);
1214	return fid;
1215
1216clunk_fid:
1217	kfree(wqids);
1218	p9_client_clunk(fid);
1219	fid = NULL;
1220
1221error:
1222	if (fid && (fid != oldfid))
1223		p9_fid_destroy(fid);
1224
1225	return ERR_PTR(err);
1226}
1227EXPORT_SYMBOL(p9_client_walk);
1228
1229int p9_client_open(struct p9_fid *fid, int mode)
1230{
1231	int err;
1232	struct p9_client *clnt;
1233	struct p9_req_t *req;
1234	struct p9_qid qid;
1235	int iounit;
1236
1237	clnt = fid->clnt;
1238	p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1239		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1240	err = 0;
1241
1242	if (fid->mode != -1)
1243		return -EINVAL;
1244
1245	if (p9_is_proto_dotl(clnt))
1246		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1247	else
1248		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1249	if (IS_ERR(req)) {
1250		err = PTR_ERR(req);
1251		goto error;
1252	}
1253
1254	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1255	if (err) {
1256		trace_9p_protocol_dump(clnt, req->rc);
1257		goto free_and_error;
1258	}
1259
1260	p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1261		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1262		(unsigned long long)qid.path, qid.version, iounit);
1263
1264	fid->mode = mode;
1265	fid->iounit = iounit;
1266
1267free_and_error:
1268	p9_free_req(clnt, req);
1269error:
1270	return err;
1271}
1272EXPORT_SYMBOL(p9_client_open);
1273
1274int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1275		kgid_t gid, struct p9_qid *qid)
1276{
1277	int err = 0;
1278	struct p9_client *clnt;
1279	struct p9_req_t *req;
1280	int iounit;
1281
1282	p9_debug(P9_DEBUG_9P,
1283			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1284			ofid->fid, name, flags, mode,
1285		 	from_kgid(&init_user_ns, gid));
1286	clnt = ofid->clnt;
1287
1288	if (ofid->mode != -1)
1289		return -EINVAL;
1290
1291	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1292			mode, gid);
1293	if (IS_ERR(req)) {
1294		err = PTR_ERR(req);
1295		goto error;
1296	}
1297
1298	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1299	if (err) {
1300		trace_9p_protocol_dump(clnt, req->rc);
1301		goto free_and_error;
1302	}
1303
1304	p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1305			qid->type,
1306			(unsigned long long)qid->path,
1307			qid->version, iounit);
1308
1309	ofid->mode = mode;
1310	ofid->iounit = iounit;
1311
1312free_and_error:
1313	p9_free_req(clnt, req);
1314error:
1315	return err;
1316}
1317EXPORT_SYMBOL(p9_client_create_dotl);
1318
1319int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1320		     char *extension)
1321{
1322	int err;
1323	struct p9_client *clnt;
1324	struct p9_req_t *req;
1325	struct p9_qid qid;
1326	int iounit;
1327
1328	p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1329						fid->fid, name, perm, mode);
1330	err = 0;
1331	clnt = fid->clnt;
1332
1333	if (fid->mode != -1)
1334		return -EINVAL;
1335
1336	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1337				mode, extension);
1338	if (IS_ERR(req)) {
1339		err = PTR_ERR(req);
1340		goto error;
1341	}
1342
1343	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1344	if (err) {
1345		trace_9p_protocol_dump(clnt, req->rc);
1346		goto free_and_error;
1347	}
1348
1349	p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1350				qid.type,
1351				(unsigned long long)qid.path,
1352				qid.version, iounit);
1353
1354	fid->mode = mode;
1355	fid->iounit = iounit;
1356
1357free_and_error:
1358	p9_free_req(clnt, req);
1359error:
1360	return err;
1361}
1362EXPORT_SYMBOL(p9_client_fcreate);
1363
1364int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
1365		struct p9_qid *qid)
1366{
1367	int err = 0;
1368	struct p9_client *clnt;
1369	struct p9_req_t *req;
1370
1371	p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1372			dfid->fid, name, symtgt);
1373	clnt = dfid->clnt;
1374
1375	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1376			gid);
1377	if (IS_ERR(req)) {
1378		err = PTR_ERR(req);
1379		goto error;
1380	}
1381
1382	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1383	if (err) {
1384		trace_9p_protocol_dump(clnt, req->rc);
1385		goto free_and_error;
1386	}
1387
1388	p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1389			qid->type, (unsigned long long)qid->path, qid->version);
1390
1391free_and_error:
1392	p9_free_req(clnt, req);
1393error:
1394	return err;
1395}
1396EXPORT_SYMBOL(p9_client_symlink);
1397
1398int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1399{
1400	struct p9_client *clnt;
1401	struct p9_req_t *req;
1402
1403	p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1404			dfid->fid, oldfid->fid, newname);
1405	clnt = dfid->clnt;
1406	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1407			newname);
1408	if (IS_ERR(req))
1409		return PTR_ERR(req);
1410
1411	p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1412	p9_free_req(clnt, req);
1413	return 0;
1414}
1415EXPORT_SYMBOL(p9_client_link);
1416
1417int p9_client_fsync(struct p9_fid *fid, int datasync)
1418{
1419	int err;
1420	struct p9_client *clnt;
1421	struct p9_req_t *req;
1422
1423	p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1424			fid->fid, datasync);
1425	err = 0;
1426	clnt = fid->clnt;
1427
1428	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1429	if (IS_ERR(req)) {
1430		err = PTR_ERR(req);
1431		goto error;
1432	}
1433
1434	p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1435
1436	p9_free_req(clnt, req);
1437
1438error:
1439	return err;
1440}
1441EXPORT_SYMBOL(p9_client_fsync);
1442
1443int p9_client_clunk(struct p9_fid *fid)
1444{
1445	int err;
1446	struct p9_client *clnt;
1447	struct p9_req_t *req;
1448	int retries = 0;
1449
1450	if (!fid) {
1451		pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1452			__func__, task_pid_nr(current));
1453		dump_stack();
1454		return 0;
1455	}
1456
1457again:
1458	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1459								retries);
1460	err = 0;
1461	clnt = fid->clnt;
1462
1463	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1464	if (IS_ERR(req)) {
1465		err = PTR_ERR(req);
1466		goto error;
1467	}
1468
1469	p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1470
1471	p9_free_req(clnt, req);
1472error:
1473	/*
1474	 * Fid is not valid even after a failed clunk
1475	 * If interrupted, retry once then give up and
1476	 * leak fid until umount.
1477	 */
1478	if (err == -ERESTARTSYS) {
1479		if (retries++ == 0)
1480			goto again;
1481	} else
1482		p9_fid_destroy(fid);
1483	return err;
1484}
1485EXPORT_SYMBOL(p9_client_clunk);
1486
1487int p9_client_remove(struct p9_fid *fid)
1488{
1489	int err;
1490	struct p9_client *clnt;
1491	struct p9_req_t *req;
1492
1493	p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1494	err = 0;
1495	clnt = fid->clnt;
1496
1497	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1498	if (IS_ERR(req)) {
1499		err = PTR_ERR(req);
1500		goto error;
1501	}
1502
1503	p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1504
1505	p9_free_req(clnt, req);
1506error:
1507	if (err == -ERESTARTSYS)
1508		p9_client_clunk(fid);
1509	else
1510		p9_fid_destroy(fid);
1511	return err;
1512}
1513EXPORT_SYMBOL(p9_client_remove);
1514
1515int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1516{
1517	int err = 0;
1518	struct p9_req_t *req;
1519	struct p9_client *clnt;
1520
1521	p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1522		   dfid->fid, name, flags);
1523
1524	clnt = dfid->clnt;
1525	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1526	if (IS_ERR(req)) {
1527		err = PTR_ERR(req);
1528		goto error;
1529	}
1530	p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1531
1532	p9_free_req(clnt, req);
1533error:
1534	return err;
1535}
1536EXPORT_SYMBOL(p9_client_unlinkat);
1537
1538int
1539p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1540{
1541	struct p9_client *clnt = fid->clnt;
1542	struct p9_req_t *req;
1543	int total = 0;
1544	*err = 0;
1545
1546	p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1547		   fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1548
1549	while (iov_iter_count(to)) {
1550		int count = iov_iter_count(to);
1551		int rsize, non_zc = 0;
1552		char *dataptr;
1553			
1554		rsize = fid->iounit;
1555		if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1556			rsize = clnt->msize - P9_IOHDRSZ;
1557
1558		if (count < rsize)
1559			rsize = count;
1560
1561		/* Don't bother zerocopy for small IO (< 1024) */
1562		if (clnt->trans_mod->zc_request && rsize > 1024) {
1563			/*
1564			 * response header len is 11
1565			 * PDU Header(7) + IO Size (4)
1566			 */
1567			req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1568					       0, 11, "dqd", fid->fid,
1569					       offset, rsize);
1570		} else {
1571			non_zc = 1;
1572			req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1573					    rsize);
1574		}
1575		if (IS_ERR(req)) {
1576			*err = PTR_ERR(req);
1577			break;
1578		}
1579
1580		*err = p9pdu_readf(req->rc, clnt->proto_version,
1581				   "D", &count, &dataptr);
1582		if (*err) {
1583			trace_9p_protocol_dump(clnt, req->rc);
1584			p9_free_req(clnt, req);
1585			break;
1586		}
1587		if (rsize < count) {
1588			pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1589			count = rsize;
1590		}
1591
1592		p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1593		if (!count) {
1594			p9_free_req(clnt, req);
1595			break;
1596		}
1597
1598		if (non_zc) {
1599			int n = copy_to_iter(dataptr, count, to);
1600			total += n;
1601			offset += n;
1602			if (n != count) {
1603				*err = -EFAULT;
1604				p9_free_req(clnt, req);
1605				break;
1606			}
1607		} else {
1608			iov_iter_advance(to, count);
1609			total += count;
1610			offset += count;
1611		}
1612		p9_free_req(clnt, req);
1613	}
1614	return total;
1615}
1616EXPORT_SYMBOL(p9_client_read);
1617
1618int
1619p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1620{
1621	struct p9_client *clnt = fid->clnt;
1622	struct p9_req_t *req;
1623	int total = 0;
1624	*err = 0;
1625
1626	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1627				fid->fid, (unsigned long long) offset,
1628				iov_iter_count(from));
1629
1630	while (iov_iter_count(from)) {
1631		int count = iov_iter_count(from);
1632		int rsize = fid->iounit;
1633		if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1634			rsize = clnt->msize - P9_IOHDRSZ;
1635
1636		if (count < rsize)
1637			rsize = count;
1638
1639		/* Don't bother zerocopy for small IO (< 1024) */
1640		if (clnt->trans_mod->zc_request && rsize > 1024) {
1641			req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1642					       rsize, P9_ZC_HDR_SZ, "dqd",
1643					       fid->fid, offset, rsize);
1644		} else {
1645			req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1646						    offset, rsize, from);
1647		}
1648		if (IS_ERR(req)) {
1649			*err = PTR_ERR(req);
1650			break;
1651		}
1652
1653		*err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1654		if (*err) {
1655			trace_9p_protocol_dump(clnt, req->rc);
1656			p9_free_req(clnt, req);
1657			break;
1658		}
1659		if (rsize < count) {
1660			pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1661			count = rsize;
1662		}
1663
1664		p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1665
1666		p9_free_req(clnt, req);
1667		iov_iter_advance(from, count);
1668		total += count;
1669		offset += count;
1670	}
1671	return total;
1672}
1673EXPORT_SYMBOL(p9_client_write);
1674
1675struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1676{
1677	int err;
1678	struct p9_client *clnt;
1679	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1680	struct p9_req_t *req;
1681	u16 ignored;
1682
1683	p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1684
1685	if (!ret)
1686		return ERR_PTR(-ENOMEM);
1687
1688	err = 0;
1689	clnt = fid->clnt;
1690
1691	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1692	if (IS_ERR(req)) {
1693		err = PTR_ERR(req);
1694		goto error;
1695	}
1696
1697	err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1698	if (err) {
1699		trace_9p_protocol_dump(clnt, req->rc);
1700		p9_free_req(clnt, req);
1701		goto error;
1702	}
1703
1704	p9_debug(P9_DEBUG_9P,
1705		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1706		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1707		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1708		"<<<    uid=%d gid=%d n_muid=%d\n",
1709		ret->size, ret->type, ret->dev, ret->qid.type,
1710		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1711		ret->atime, ret->mtime, (unsigned long long)ret->length,
1712		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1713		from_kuid(&init_user_ns, ret->n_uid),
1714		from_kgid(&init_user_ns, ret->n_gid),
1715		from_kuid(&init_user_ns, ret->n_muid));
1716
1717	p9_free_req(clnt, req);
1718	return ret;
1719
1720error:
1721	kfree(ret);
1722	return ERR_PTR(err);
1723}
1724EXPORT_SYMBOL(p9_client_stat);
1725
1726struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1727							u64 request_mask)
1728{
1729	int err;
1730	struct p9_client *clnt;
1731	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1732								GFP_KERNEL);
1733	struct p9_req_t *req;
1734
1735	p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1736							fid->fid, request_mask);
1737
1738	if (!ret)
1739		return ERR_PTR(-ENOMEM);
1740
1741	err = 0;
1742	clnt = fid->clnt;
1743
1744	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1745	if (IS_ERR(req)) {
1746		err = PTR_ERR(req);
1747		goto error;
1748	}
1749
1750	err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1751	if (err) {
1752		trace_9p_protocol_dump(clnt, req->rc);
1753		p9_free_req(clnt, req);
1754		goto error;
1755	}
1756
1757	p9_debug(P9_DEBUG_9P,
1758		"<<< RGETATTR st_result_mask=%lld\n"
1759		"<<< qid=%x.%llx.%x\n"
1760		"<<< st_mode=%8.8x st_nlink=%llu\n"
1761		"<<< st_uid=%d st_gid=%d\n"
1762		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1763		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1764		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1765		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1766		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1767		"<<< st_gen=%lld st_data_version=%lld",
1768		ret->st_result_mask, ret->qid.type, ret->qid.path,
1769		ret->qid.version, ret->st_mode, ret->st_nlink,
1770		from_kuid(&init_user_ns, ret->st_uid),
1771		from_kgid(&init_user_ns, ret->st_gid),
1772		ret->st_rdev, ret->st_size, ret->st_blksize,
1773		ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1774		ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1775		ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1776		ret->st_gen, ret->st_data_version);
1777
1778	p9_free_req(clnt, req);
1779	return ret;
1780
1781error:
1782	kfree(ret);
1783	return ERR_PTR(err);
1784}
1785EXPORT_SYMBOL(p9_client_getattr_dotl);
1786
1787static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1788{
1789	int ret;
1790
1791	/* NOTE: size shouldn't include its own length */
1792	/* size[2] type[2] dev[4] qid[13] */
1793	/* mode[4] atime[4] mtime[4] length[8]*/
1794	/* name[s] uid[s] gid[s] muid[s] */
1795	ret = 2+4+13+4+4+4+8+2+2+2+2;
1796
1797	if (wst->name)
1798		ret += strlen(wst->name);
1799	if (wst->uid)
1800		ret += strlen(wst->uid);
1801	if (wst->gid)
1802		ret += strlen(wst->gid);
1803	if (wst->muid)
1804		ret += strlen(wst->muid);
1805
1806	if ((proto_version == p9_proto_2000u) ||
1807		(proto_version == p9_proto_2000L)) {
1808		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1809		if (wst->extension)
1810			ret += strlen(wst->extension);
1811	}
1812
1813	return ret;
1814}
1815
1816int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1817{
1818	int err;
1819	struct p9_req_t *req;
1820	struct p9_client *clnt;
1821
1822	err = 0;
1823	clnt = fid->clnt;
1824	wst->size = p9_client_statsize(wst, clnt->proto_version);
1825	p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1826	p9_debug(P9_DEBUG_9P,
1827		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1828		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1829		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1830		"     uid=%d gid=%d n_muid=%d\n",
1831		wst->size, wst->type, wst->dev, wst->qid.type,
1832		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1833		wst->atime, wst->mtime, (unsigned long long)wst->length,
1834		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1835		from_kuid(&init_user_ns, wst->n_uid),
1836		from_kgid(&init_user_ns, wst->n_gid),
1837		from_kuid(&init_user_ns, wst->n_muid));
1838
1839	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1840	if (IS_ERR(req)) {
1841		err = PTR_ERR(req);
1842		goto error;
1843	}
1844
1845	p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1846
1847	p9_free_req(clnt, req);
1848error:
1849	return err;
1850}
1851EXPORT_SYMBOL(p9_client_wstat);
1852
1853int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1854{
1855	int err;
1856	struct p9_req_t *req;
1857	struct p9_client *clnt;
1858
1859	err = 0;
1860	clnt = fid->clnt;
1861	p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1862	p9_debug(P9_DEBUG_9P,
1863		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1864		"    atime_sec=%lld atime_nsec=%lld\n"
1865		"    mtime_sec=%lld mtime_nsec=%lld\n",
1866		p9attr->valid, p9attr->mode,
1867		from_kuid(&init_user_ns, p9attr->uid),
1868		from_kgid(&init_user_ns, p9attr->gid),
1869		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1870		p9attr->mtime_sec, p9attr->mtime_nsec);
1871
1872	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1873
1874	if (IS_ERR(req)) {
1875		err = PTR_ERR(req);
1876		goto error;
1877	}
1878	p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1879	p9_free_req(clnt, req);
1880error:
1881	return err;
1882}
1883EXPORT_SYMBOL(p9_client_setattr);
1884
1885int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1886{
1887	int err;
1888	struct p9_req_t *req;
1889	struct p9_client *clnt;
1890
1891	err = 0;
1892	clnt = fid->clnt;
1893
1894	p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1895
1896	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1897	if (IS_ERR(req)) {
1898		err = PTR_ERR(req);
1899		goto error;
1900	}
1901
1902	err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1903		&sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1904		&sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1905	if (err) {
1906		trace_9p_protocol_dump(clnt, req->rc);
1907		p9_free_req(clnt, req);
1908		goto error;
1909	}
1910
1911	p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1912		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1913		"fsid %llu namelen %ld\n",
1914		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1915		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1916		sb->fsid, (long int)sb->namelen);
1917
1918	p9_free_req(clnt, req);
1919error:
1920	return err;
1921}
1922EXPORT_SYMBOL(p9_client_statfs);
1923
1924int p9_client_rename(struct p9_fid *fid,
1925		     struct p9_fid *newdirfid, const char *name)
1926{
1927	int err;
1928	struct p9_req_t *req;
1929	struct p9_client *clnt;
1930
1931	err = 0;
1932	clnt = fid->clnt;
1933
1934	p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1935			fid->fid, newdirfid->fid, name);
1936
1937	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1938			newdirfid->fid, name);
1939	if (IS_ERR(req)) {
1940		err = PTR_ERR(req);
1941		goto error;
1942	}
1943
1944	p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1945
1946	p9_free_req(clnt, req);
1947error:
1948	return err;
1949}
1950EXPORT_SYMBOL(p9_client_rename);
1951
1952int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1953		       struct p9_fid *newdirfid, const char *new_name)
1954{
1955	int err;
1956	struct p9_req_t *req;
1957	struct p9_client *clnt;
1958
1959	err = 0;
1960	clnt = olddirfid->clnt;
1961
1962	p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1963		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1964		   newdirfid->fid, new_name);
1965
1966	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1967			    old_name, newdirfid->fid, new_name);
1968	if (IS_ERR(req)) {
1969		err = PTR_ERR(req);
1970		goto error;
1971	}
1972
1973	p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1974		   newdirfid->fid, new_name);
1975
1976	p9_free_req(clnt, req);
1977error:
1978	return err;
1979}
1980EXPORT_SYMBOL(p9_client_renameat);
1981
1982/*
1983 * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1984 */
1985struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1986				const char *attr_name, u64 *attr_size)
1987{
1988	int err;
1989	struct p9_req_t *req;
1990	struct p9_client *clnt;
1991	struct p9_fid *attr_fid;
1992
1993	err = 0;
1994	clnt = file_fid->clnt;
1995	attr_fid = p9_fid_create(clnt);
1996	if (IS_ERR(attr_fid)) {
1997		err = PTR_ERR(attr_fid);
1998		attr_fid = NULL;
1999		goto error;
2000	}
2001	p9_debug(P9_DEBUG_9P,
2002		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2003		file_fid->fid, attr_fid->fid, attr_name);
2004
2005	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2006			file_fid->fid, attr_fid->fid, attr_name);
2007	if (IS_ERR(req)) {
2008		err = PTR_ERR(req);
2009		goto error;
2010	}
2011	err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2012	if (err) {
2013		trace_9p_protocol_dump(clnt, req->rc);
2014		p9_free_req(clnt, req);
2015		goto clunk_fid;
2016	}
2017	p9_free_req(clnt, req);
2018	p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2019		attr_fid->fid, *attr_size);
2020	return attr_fid;
2021clunk_fid:
2022	p9_client_clunk(attr_fid);
2023	attr_fid = NULL;
2024error:
2025	if (attr_fid && (attr_fid != file_fid))
2026		p9_fid_destroy(attr_fid);
2027
2028	return ERR_PTR(err);
2029}
2030EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2031
2032int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2033			u64 attr_size, int flags)
2034{
2035	int err;
2036	struct p9_req_t *req;
2037	struct p9_client *clnt;
2038
2039	p9_debug(P9_DEBUG_9P,
2040		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2041		fid->fid, name, (long long)attr_size, flags);
2042	err = 0;
2043	clnt = fid->clnt;
2044	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2045			fid->fid, name, attr_size, flags);
2046	if (IS_ERR(req)) {
2047		err = PTR_ERR(req);
2048		goto error;
2049	}
2050	p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2051	p9_free_req(clnt, req);
2052error:
2053	return err;
2054}
2055EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2056
2057int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2058{
2059	int err, rsize, non_zc = 0;
2060	struct p9_client *clnt;
2061	struct p9_req_t *req;
2062	char *dataptr;
2063	struct kvec kv = {.iov_base = data, .iov_len = count};
2064	struct iov_iter to;
2065
2066	iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2067
2068	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2069				fid->fid, (unsigned long long) offset, count);
2070
2071	err = 0;
2072	clnt = fid->clnt;
2073
2074	rsize = fid->iounit;
2075	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2076		rsize = clnt->msize - P9_READDIRHDRSZ;
2077
2078	if (count < rsize)
2079		rsize = count;
2080
2081	/* Don't bother zerocopy for small IO (< 1024) */
2082	if (clnt->trans_mod->zc_request && rsize > 1024) {
2083		/*
2084		 * response header len is 11
2085		 * PDU Header(7) + IO Size (4)
2086		 */
2087		req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2088				       11, "dqd", fid->fid, offset, rsize);
2089	} else {
2090		non_zc = 1;
2091		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2092				    offset, rsize);
2093	}
2094	if (IS_ERR(req)) {
2095		err = PTR_ERR(req);
2096		goto error;
2097	}
2098
2099	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2100	if (err) {
2101		trace_9p_protocol_dump(clnt, req->rc);
2102		goto free_and_error;
2103	}
 
 
 
 
2104
2105	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2106
2107	if (non_zc)
2108		memmove(data, dataptr, count);
2109
2110	p9_free_req(clnt, req);
2111	return count;
2112
2113free_and_error:
2114	p9_free_req(clnt, req);
2115error:
2116	return err;
2117}
2118EXPORT_SYMBOL(p9_client_readdir);
2119
2120int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2121			dev_t rdev, kgid_t gid, struct p9_qid *qid)
2122{
2123	int err;
2124	struct p9_client *clnt;
2125	struct p9_req_t *req;
2126
2127	err = 0;
2128	clnt = fid->clnt;
2129	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2130		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2131	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2132		MAJOR(rdev), MINOR(rdev), gid);
2133	if (IS_ERR(req))
2134		return PTR_ERR(req);
2135
2136	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2137	if (err) {
2138		trace_9p_protocol_dump(clnt, req->rc);
2139		goto error;
2140	}
2141	p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2142				(unsigned long long)qid->path, qid->version);
2143
2144error:
2145	p9_free_req(clnt, req);
2146	return err;
2147
2148}
2149EXPORT_SYMBOL(p9_client_mknod_dotl);
2150
2151int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2152				kgid_t gid, struct p9_qid *qid)
2153{
2154	int err;
2155	struct p9_client *clnt;
2156	struct p9_req_t *req;
2157
2158	err = 0;
2159	clnt = fid->clnt;
2160	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2161		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2162	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2163		gid);
2164	if (IS_ERR(req))
2165		return PTR_ERR(req);
2166
2167	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2168	if (err) {
2169		trace_9p_protocol_dump(clnt, req->rc);
2170		goto error;
2171	}
2172	p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2173				(unsigned long long)qid->path, qid->version);
2174
2175error:
2176	p9_free_req(clnt, req);
2177	return err;
2178
2179}
2180EXPORT_SYMBOL(p9_client_mkdir_dotl);
2181
2182int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2183{
2184	int err;
2185	struct p9_client *clnt;
2186	struct p9_req_t *req;
2187
2188	err = 0;
2189	clnt = fid->clnt;
2190	p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2191			"start %lld length %lld proc_id %d client_id %s\n",
2192			fid->fid, flock->type, flock->flags, flock->start,
2193			flock->length, flock->proc_id, flock->client_id);
2194
2195	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2196				flock->flags, flock->start, flock->length,
2197					flock->proc_id, flock->client_id);
2198
2199	if (IS_ERR(req))
2200		return PTR_ERR(req);
2201
2202	err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2203	if (err) {
2204		trace_9p_protocol_dump(clnt, req->rc);
2205		goto error;
2206	}
2207	p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2208error:
2209	p9_free_req(clnt, req);
2210	return err;
2211
2212}
2213EXPORT_SYMBOL(p9_client_lock_dotl);
2214
2215int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2216{
2217	int err;
2218	struct p9_client *clnt;
2219	struct p9_req_t *req;
2220
2221	err = 0;
2222	clnt = fid->clnt;
2223	p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2224		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2225		glock->start, glock->length, glock->proc_id, glock->client_id);
2226
2227	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2228		glock->start, glock->length, glock->proc_id, glock->client_id);
2229
2230	if (IS_ERR(req))
2231		return PTR_ERR(req);
2232
2233	err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2234			&glock->start, &glock->length, &glock->proc_id,
2235			&glock->client_id);
2236	if (err) {
2237		trace_9p_protocol_dump(clnt, req->rc);
2238		goto error;
2239	}
2240	p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2241		"proc_id %d client_id %s\n", glock->type, glock->start,
2242		glock->length, glock->proc_id, glock->client_id);
2243error:
2244	p9_free_req(clnt, req);
2245	return err;
2246}
2247EXPORT_SYMBOL(p9_client_getlock_dotl);
2248
2249int p9_client_readlink(struct p9_fid *fid, char **target)
2250{
2251	int err;
2252	struct p9_client *clnt;
2253	struct p9_req_t *req;
2254
2255	err = 0;
2256	clnt = fid->clnt;
2257	p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2258
2259	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2260	if (IS_ERR(req))
2261		return PTR_ERR(req);
2262
2263	err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2264	if (err) {
2265		trace_9p_protocol_dump(clnt, req->rc);
2266		goto error;
2267	}
2268	p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2269error:
2270	p9_free_req(clnt, req);
2271	return err;
2272}
2273EXPORT_SYMBOL(p9_client_readlink);
v5.4
   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_options - parse mount options into client structure
 126 * @opts: options string passed from mount
 127 * @clnt: existing v9fs client information
 128 *
 129 * Return 0 upon success, -ERRNO upon failure
 130 */
 131
 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_req_alloc - Allocate a new request.
 260 * @c: Client session.
 261 * @type: Transaction type.
 262 * @max_size: Maximum packet size for this request.
 
 
 
 
 
 
 
 263 *
 264 * Context: Process context.
 265 * Return: Pointer to new request.
 266 */
 
 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 *
 418 */
 419void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 420{
 421	p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc.tag);
 422
 423	/*
 424	 * This barrier is needed to make sure any change made to req before
 425	 * the status change is visible to another thread
 426	 */
 427	smp_wmb();
 428	req->status = status;
 429
 430	wake_up(&req->wq);
 431	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc.tag);
 432	p9_req_put(req);
 433}
 434EXPORT_SYMBOL(p9_client_cb);
 435
 436/**
 437 * p9_parse_header - parse header arguments out of a packet
 438 * @pdu: packet to parse
 439 * @size: size of packet
 440 * @type: type of request
 441 * @tag: tag of packet
 442 * @rewind: set if we need to rewind offset afterwards
 443 */
 444
 445int
 446p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 447								int rewind)
 448{
 449	int8_t r_type;
 450	int16_t r_tag;
 451	int32_t r_size;
 452	int offset = pdu->offset;
 453	int err;
 454
 455	pdu->offset = 0;
 
 
 456
 457	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 458	if (err)
 459		goto rewind_and_exit;
 460
 
 
 
 
 
 
 
 461	if (type)
 462		*type = r_type;
 463	if (tag)
 464		*tag = r_tag;
 465	if (size)
 466		*size = r_size;
 467
 468	if (pdu->size != r_size || r_size < 7) {
 469		err = -EINVAL;
 470		goto rewind_and_exit;
 471	}
 472
 473	pdu->id = r_type;
 474	pdu->tag = r_tag;
 475
 476	p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 477		 pdu->size, pdu->id, pdu->tag);
 478
 479rewind_and_exit:
 480	if (rewind)
 481		pdu->offset = offset;
 482	return err;
 483}
 484EXPORT_SYMBOL(p9_parse_header);
 485
 486/**
 487 * p9_check_errors - check 9p packet for error return and process it
 488 * @c: current client instance
 489 * @req: request to parse and check for error conditions
 490 *
 491 * returns error code if one is discovered, otherwise returns 0
 492 *
 493 * this will have to be more complicated if we have multiple
 494 * error packet types
 495 */
 496
 497static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 498{
 499	int8_t type;
 500	int err;
 501	int ecode;
 502
 503	err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
 504	if (req->rc.size >= c->msize) {
 505		p9_debug(P9_DEBUG_ERROR,
 506			 "requested packet size too big: %d\n",
 507			 req->rc.size);
 508		return -EIO;
 509	}
 510	/*
 511	 * dump the response from server
 512	 * This should be after check errors which poplulate pdu_fcall.
 513	 */
 514	trace_9p_protocol_dump(c, &req->rc);
 515	if (err) {
 516		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 517		return err;
 518	}
 519	if (type != P9_RERROR && type != P9_RLERROR)
 520		return 0;
 521
 522	if (!p9_is_proto_dotl(c)) {
 523		char *ename;
 524		err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
 525				  &ename, &ecode);
 526		if (err)
 527			goto out_err;
 528
 529		if (p9_is_proto_dotu(c) && ecode < 512)
 530			err = -ecode;
 531
 532		if (!err) {
 533			err = p9_errstr2errno(ename, strlen(ename));
 534
 535			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 536				 -ecode, ename);
 537		}
 538		kfree(ename);
 539	} else {
 540		err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
 541		err = -ecode;
 542
 543		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 544	}
 545
 546	return err;
 547
 548out_err:
 549	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 550
 551	return err;
 552}
 553
 554/**
 555 * p9_check_zc_errors - check 9p packet for error return and process it
 556 * @c: current client instance
 557 * @req: request to parse and check for error conditions
 558 * @in_hdrlen: Size of response protocol buffer.
 559 *
 560 * returns error code if one is discovered, otherwise returns 0
 561 *
 562 * this will have to be more complicated if we have multiple
 563 * error packet types
 564 */
 565
 566static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
 567			      struct iov_iter *uidata, int in_hdrlen)
 568{
 569	int err;
 570	int ecode;
 571	int8_t type;
 572	char *ename = NULL;
 573
 574	err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
 575	/*
 576	 * dump the response from server
 577	 * This should be after parse_header which poplulate pdu_fcall.
 578	 */
 579	trace_9p_protocol_dump(c, &req->rc);
 580	if (err) {
 581		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 582		return err;
 583	}
 584
 585	if (type != P9_RERROR && type != P9_RLERROR)
 586		return 0;
 587
 588	if (!p9_is_proto_dotl(c)) {
 589		/* Error is reported in string format */
 590		int len;
 591		/* 7 = header size for RERROR; */
 592		int inline_len = in_hdrlen - 7;
 593
 594		len = req->rc.size - req->rc.offset;
 595		if (len > (P9_ZC_HDR_SZ - 7)) {
 596			err = -EFAULT;
 597			goto out_err;
 598		}
 599
 600		ename = &req->rc.sdata[req->rc.offset];
 601		if (len > inline_len) {
 602			/* We have error in external buffer */
 603			if (!copy_from_iter_full(ename + inline_len,
 604					     len - inline_len, uidata)) {
 
 605				err = -EFAULT;
 606				goto out_err;
 607			}
 608		}
 609		ename = NULL;
 610		err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
 611				  &ename, &ecode);
 612		if (err)
 613			goto out_err;
 614
 615		if (p9_is_proto_dotu(c) && ecode < 512)
 616			err = -ecode;
 617
 618		if (!err) {
 619			err = p9_errstr2errno(ename, strlen(ename));
 620
 621			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 622				 -ecode, ename);
 623		}
 624		kfree(ename);
 625	} else {
 626		err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
 627		err = -ecode;
 628
 629		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 630	}
 631	return err;
 632
 633out_err:
 634	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 635	return err;
 636}
 637
 638static struct p9_req_t *
 639p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 640
 641/**
 642 * p9_client_flush - flush (cancel) a request
 643 * @c: client state
 644 * @oldreq: request to cancel
 645 *
 646 * This sents a flush for a particular request and links
 647 * the flush request to the original request.  The current
 648 * code only supports a single flush request although the protocol
 649 * allows for multiple flush requests to be sent for a single request.
 650 *
 651 */
 652
 653static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 654{
 655	struct p9_req_t *req;
 656	int16_t oldtag;
 657	int err;
 658
 659	err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
 660	if (err)
 661		return err;
 662
 663	p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 664
 665	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 666	if (IS_ERR(req))
 667		return PTR_ERR(req);
 668
 669	/*
 670	 * if we haven't received a response for oldreq,
 671	 * remove it from the list
 672	 */
 673	if (oldreq->status == REQ_STATUS_SENT) {
 674		if (c->trans_mod->cancelled)
 675			c->trans_mod->cancelled(c, oldreq);
 676	}
 677
 678	p9_tag_remove(c, req);
 679	return 0;
 680}
 681
 682static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 683					      int8_t type, int req_size,
 684					      const char *fmt, va_list ap)
 685{
 686	int err;
 687	struct p9_req_t *req;
 688
 689	p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 690
 691	/* we allow for any status other than disconnected */
 692	if (c->status == Disconnected)
 693		return ERR_PTR(-EIO);
 694
 695	/* if status is begin_disconnected we allow only clunk request */
 696	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
 697		return ERR_PTR(-EIO);
 698
 699	req = p9_tag_alloc(c, type, req_size);
 
 
 
 
 
 
 
 700	if (IS_ERR(req))
 701		return req;
 702
 703	/* marshall the data */
 704	p9pdu_prepare(&req->tc, req->tc.tag, type);
 705	err = p9pdu_vwritef(&req->tc, c->proto_version, fmt, ap);
 706	if (err)
 707		goto reterr;
 708	p9pdu_finalize(c, &req->tc);
 709	trace_9p_client_req(c, type, req->tc.tag);
 710	return req;
 711reterr:
 712	p9_tag_remove(c, req);
 713	/* We have to put also the 2nd reference as it won't be used */
 714	p9_req_put(req);
 715	return ERR_PTR(err);
 716}
 717
 718/**
 719 * p9_client_rpc - issue a request and wait for a response
 720 * @c: client session
 721 * @type: type of request
 722 * @fmt: protocol format string (see protocol.c)
 723 *
 724 * Returns request structure (which client must free using p9_tag_remove)
 725 */
 726
 727static struct p9_req_t *
 728p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 729{
 730	va_list ap;
 731	int sigpending, err;
 732	unsigned long flags;
 733	struct p9_req_t *req;
 734
 735	va_start(ap, fmt);
 736	req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
 737	va_end(ap);
 738	if (IS_ERR(req))
 739		return req;
 740
 741	if (signal_pending(current)) {
 742		sigpending = 1;
 743		clear_thread_flag(TIF_SIGPENDING);
 744	} else
 745		sigpending = 0;
 746
 747	err = c->trans_mod->request(c, req);
 748	if (err < 0) {
 749		/* write won't happen */
 750		p9_req_put(req);
 751		if (err != -ERESTARTSYS && err != -EFAULT)
 752			c->status = Disconnected;
 753		goto recalc_sigpending;
 754	}
 755again:
 756	/* Wait for the response */
 757	err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
 
 758
 759	/*
 760	 * Make sure our req is coherent with regard to updates in other
 761	 * threads - echoes to wmb() in the callback
 762	 */
 763	smp_rmb();
 764
 765	if ((err == -ERESTARTSYS) && (c->status == Connected)
 766				  && (type == P9_TFLUSH)) {
 767		sigpending = 1;
 768		clear_thread_flag(TIF_SIGPENDING);
 769		goto again;
 770	}
 771
 772	if (req->status == REQ_STATUS_ERROR) {
 773		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 774		err = req->t_err;
 775	}
 776	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 777		p9_debug(P9_DEBUG_MUX, "flushing\n");
 778		sigpending = 1;
 779		clear_thread_flag(TIF_SIGPENDING);
 780
 781		if (c->trans_mod->cancel(c, req))
 782			p9_client_flush(c, req);
 783
 784		/* if we received the response anyway, don't signal error */
 785		if (req->status == REQ_STATUS_RCVD)
 786			err = 0;
 787	}
 788recalc_sigpending:
 789	if (sigpending) {
 790		spin_lock_irqsave(&current->sighand->siglock, flags);
 791		recalc_sigpending();
 792		spin_unlock_irqrestore(&current->sighand->siglock, flags);
 793	}
 794	if (err < 0)
 795		goto reterr;
 796
 797	err = p9_check_errors(c, req);
 798	trace_9p_client_res(c, type, req->rc.tag, err);
 799	if (!err)
 800		return req;
 801reterr:
 802	p9_tag_remove(c, req);
 803	return ERR_PTR(safe_errno(err));
 804}
 805
 806/**
 807 * p9_client_zc_rpc - issue a request and wait for a response
 808 * @c: client session
 809 * @type: type of request
 810 * @uidata: destination for zero copy read
 811 * @uodata: source for zero copy write
 812 * @inlen: read buffer size
 813 * @olen: write buffer size
 814 * @hdrlen: reader header size, This is the size of response protocol data
 815 * @fmt: protocol format string (see protocol.c)
 816 *
 817 * Returns request structure (which client must free using p9_tag_remove)
 818 */
 819static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 820					 struct iov_iter *uidata,
 821					 struct iov_iter *uodata,
 822					 int inlen, int olen, int in_hdrlen,
 823					 const char *fmt, ...)
 824{
 825	va_list ap;
 826	int sigpending, err;
 827	unsigned long flags;
 828	struct p9_req_t *req;
 829
 830	va_start(ap, fmt);
 831	/*
 832	 * We allocate a inline protocol data of only 4k bytes.
 833	 * The actual content is passed in zero-copy fashion.
 834	 */
 835	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
 836	va_end(ap);
 837	if (IS_ERR(req))
 838		return req;
 839
 840	if (signal_pending(current)) {
 841		sigpending = 1;
 842		clear_thread_flag(TIF_SIGPENDING);
 843	} else
 844		sigpending = 0;
 845
 846	err = c->trans_mod->zc_request(c, req, uidata, uodata,
 847				       inlen, olen, in_hdrlen);
 848	if (err < 0) {
 849		if (err == -EIO)
 850			c->status = Disconnected;
 851		if (err != -ERESTARTSYS)
 852			goto recalc_sigpending;
 853	}
 854	if (req->status == REQ_STATUS_ERROR) {
 855		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 856		err = req->t_err;
 857	}
 858	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
 859		p9_debug(P9_DEBUG_MUX, "flushing\n");
 860		sigpending = 1;
 861		clear_thread_flag(TIF_SIGPENDING);
 862
 863		if (c->trans_mod->cancel(c, req))
 864			p9_client_flush(c, req);
 865
 866		/* if we received the response anyway, don't signal error */
 867		if (req->status == REQ_STATUS_RCVD)
 868			err = 0;
 869	}
 870recalc_sigpending:
 871	if (sigpending) {
 872		spin_lock_irqsave(&current->sighand->siglock, flags);
 873		recalc_sigpending();
 874		spin_unlock_irqrestore(&current->sighand->siglock, flags);
 875	}
 876	if (err < 0)
 877		goto reterr;
 878
 879	err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
 880	trace_9p_client_res(c, type, req->rc.tag, err);
 881	if (!err)
 882		return req;
 883reterr:
 884	p9_tag_remove(c, req);
 885	return ERR_PTR(safe_errno(err));
 886}
 887
 888static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 889{
 890	int ret;
 891	struct p9_fid *fid;
 
 892
 893	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 894	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 895	if (!fid)
 896		return NULL;
 
 
 
 
 
 
 
 897
 898	memset(&fid->qid, 0, sizeof(struct p9_qid));
 899	fid->mode = -1;
 900	fid->uid = current_fsuid();
 901	fid->clnt = clnt;
 902	fid->rdir = NULL;
 903	fid->fid = 0;
 
 
 904
 905	idr_preload(GFP_KERNEL);
 906	spin_lock_irq(&clnt->lock);
 907	ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
 908			    GFP_NOWAIT);
 909	spin_unlock_irq(&clnt->lock);
 910	idr_preload_end();
 911
 912	if (!ret)
 913		return fid;
 914
 
 915	kfree(fid);
 916	return NULL;
 917}
 918
 919static void p9_fid_destroy(struct p9_fid *fid)
 920{
 921	struct p9_client *clnt;
 922	unsigned long flags;
 923
 924	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 925	clnt = fid->clnt;
 
 926	spin_lock_irqsave(&clnt->lock, flags);
 927	idr_remove(&clnt->fids, fid->fid);
 928	spin_unlock_irqrestore(&clnt->lock, flags);
 929	kfree(fid->rdir);
 930	kfree(fid);
 931}
 932
 933static int p9_client_version(struct p9_client *c)
 934{
 935	int err = 0;
 936	struct p9_req_t *req;
 937	char *version = NULL;
 938	int msize;
 939
 940	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 941		 c->msize, c->proto_version);
 942
 943	switch (c->proto_version) {
 944	case p9_proto_2000L:
 945		req = p9_client_rpc(c, P9_TVERSION, "ds",
 946					c->msize, "9P2000.L");
 947		break;
 948	case p9_proto_2000u:
 949		req = p9_client_rpc(c, P9_TVERSION, "ds",
 950					c->msize, "9P2000.u");
 951		break;
 952	case p9_proto_legacy:
 953		req = p9_client_rpc(c, P9_TVERSION, "ds",
 954					c->msize, "9P2000");
 955		break;
 956	default:
 957		return -EINVAL;
 958	}
 959
 960	if (IS_ERR(req))
 961		return PTR_ERR(req);
 962
 963	err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version);
 964	if (err) {
 965		p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 966		trace_9p_protocol_dump(c, &req->rc);
 967		goto error;
 968	}
 969
 970	p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 971	if (!strncmp(version, "9P2000.L", 8))
 972		c->proto_version = p9_proto_2000L;
 973	else if (!strncmp(version, "9P2000.u", 8))
 974		c->proto_version = p9_proto_2000u;
 975	else if (!strncmp(version, "9P2000", 6))
 976		c->proto_version = p9_proto_legacy;
 977	else {
 978		p9_debug(P9_DEBUG_ERROR,
 979			 "server returned an unknown version: %s\n", version);
 980		err = -EREMOTEIO;
 981		goto error;
 982	}
 983
 984	if (msize < 4096) {
 985		p9_debug(P9_DEBUG_ERROR,
 986			 "server returned a msize < 4096: %d\n", msize);
 987		err = -EREMOTEIO;
 988		goto error;
 989	}
 990	if (msize < c->msize)
 991		c->msize = msize;
 992
 993error:
 994	kfree(version);
 995	p9_tag_remove(c, req);
 996
 997	return err;
 998}
 999
1000struct p9_client *p9_client_create(const char *dev_name, char *options)
1001{
1002	int err;
1003	struct p9_client *clnt;
1004	char *client_id;
1005
1006	err = 0;
1007	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1008	if (!clnt)
1009		return ERR_PTR(-ENOMEM);
1010
1011	clnt->trans_mod = NULL;
1012	clnt->trans = NULL;
1013	clnt->fcall_cache = NULL;
1014
1015	client_id = utsname()->nodename;
1016	memcpy(clnt->name, client_id, strlen(client_id) + 1);
1017
1018	spin_lock_init(&clnt->lock);
1019	idr_init(&clnt->fids);
1020	idr_init(&clnt->reqs);
 
 
 
1021
1022	err = parse_opts(options, clnt);
1023	if (err < 0)
1024		goto free_client;
1025
1026	if (!clnt->trans_mod)
1027		clnt->trans_mod = v9fs_get_default_trans();
1028
1029	if (clnt->trans_mod == NULL) {
1030		err = -EPROTONOSUPPORT;
1031		p9_debug(P9_DEBUG_ERROR,
1032			 "No transport defined or default transport\n");
1033		goto free_client;
 
 
 
 
 
 
1034	}
1035
1036	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1037		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1038
1039	err = clnt->trans_mod->create(clnt, dev_name, options);
1040	if (err)
1041		goto put_trans;
1042
1043	if (clnt->msize > clnt->trans_mod->maxsize)
1044		clnt->msize = clnt->trans_mod->maxsize;
1045
1046	if (clnt->msize < 4096) {
1047		p9_debug(P9_DEBUG_ERROR,
1048			 "Please specify a msize of at least 4k\n");
1049		err = -EINVAL;
1050		goto close_trans;
1051	}
1052
1053	err = p9_client_version(clnt);
1054	if (err)
1055		goto close_trans;
1056
1057	/* P9_HDRSZ + 4 is the smallest packet header we can have that is
1058	 * followed by data accessed from userspace by read
1059	 */
1060	clnt->fcall_cache =
1061		kmem_cache_create_usercopy("9p-fcall-cache", clnt->msize,
1062					   0, 0, P9_HDRSZ + 4,
1063					   clnt->msize - (P9_HDRSZ + 4),
1064					   NULL);
1065
1066	return clnt;
1067
1068close_trans:
1069	clnt->trans_mod->close(clnt);
 
 
1070put_trans:
1071	v9fs_put_trans(clnt->trans_mod);
 
 
1072free_client:
1073	kfree(clnt);
1074	return ERR_PTR(err);
1075}
1076EXPORT_SYMBOL(p9_client_create);
1077
1078void p9_client_destroy(struct p9_client *clnt)
1079{
1080	struct p9_fid *fid;
1081	int id;
1082
1083	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1084
1085	if (clnt->trans_mod)
1086		clnt->trans_mod->close(clnt);
1087
1088	v9fs_put_trans(clnt->trans_mod);
1089
1090	idr_for_each_entry(&clnt->fids, fid, id) {
1091		pr_info("Found fid %d not clunked\n", fid->fid);
1092		p9_fid_destroy(fid);
1093	}
1094
 
 
 
1095	p9_tag_cleanup(clnt);
1096
1097	kmem_cache_destroy(clnt->fcall_cache);
1098	kfree(clnt);
1099}
1100EXPORT_SYMBOL(p9_client_destroy);
1101
1102void p9_client_disconnect(struct p9_client *clnt)
1103{
1104	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1105	clnt->status = Disconnected;
1106}
1107EXPORT_SYMBOL(p9_client_disconnect);
1108
1109void p9_client_begin_disconnect(struct p9_client *clnt)
1110{
1111	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1112	clnt->status = BeginDisconnect;
1113}
1114EXPORT_SYMBOL(p9_client_begin_disconnect);
1115
1116struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1117	const char *uname, kuid_t n_uname, const char *aname)
1118{
1119	int err = 0;
1120	struct p9_req_t *req;
1121	struct p9_fid *fid;
1122	struct p9_qid qid;
1123
1124
1125	p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1126		 afid ? afid->fid : -1, uname, aname);
1127	fid = p9_fid_create(clnt);
1128	if (!fid) {
1129		err = -ENOMEM;
 
1130		goto error;
1131	}
1132	fid->uid = n_uname;
1133
1134	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1135			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1136	if (IS_ERR(req)) {
1137		err = PTR_ERR(req);
1138		goto error;
1139	}
1140
1141	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
1142	if (err) {
1143		trace_9p_protocol_dump(clnt, &req->rc);
1144		p9_tag_remove(clnt, req);
1145		goto error;
1146	}
1147
1148	p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1149		 qid.type, (unsigned long long)qid.path, qid.version);
1150
1151	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1152
1153	p9_tag_remove(clnt, req);
1154	return fid;
1155
1156error:
1157	if (fid)
1158		p9_fid_destroy(fid);
1159	return ERR_PTR(err);
1160}
1161EXPORT_SYMBOL(p9_client_attach);
1162
1163struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1164		const unsigned char * const *wnames, int clone)
1165{
1166	int err;
1167	struct p9_client *clnt;
1168	struct p9_fid *fid;
1169	struct p9_qid *wqids;
1170	struct p9_req_t *req;
1171	uint16_t nwqids, count;
1172
1173	err = 0;
1174	wqids = NULL;
1175	clnt = oldfid->clnt;
1176	if (clone) {
1177		fid = p9_fid_create(clnt);
1178		if (!fid) {
1179			err = -ENOMEM;
 
1180			goto error;
1181		}
1182
1183		fid->uid = oldfid->uid;
1184	} else
1185		fid = oldfid;
1186
1187
1188	p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1189		 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1190
1191	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1192								nwname, wnames);
1193	if (IS_ERR(req)) {
1194		err = PTR_ERR(req);
1195		goto error;
1196	}
1197
1198	err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1199	if (err) {
1200		trace_9p_protocol_dump(clnt, &req->rc);
1201		p9_tag_remove(clnt, req);
1202		goto clunk_fid;
1203	}
1204	p9_tag_remove(clnt, req);
1205
1206	p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1207
1208	if (nwqids != nwname) {
1209		err = -ENOENT;
1210		goto clunk_fid;
1211	}
1212
1213	for (count = 0; count < nwqids; count++)
1214		p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1215			count, wqids[count].type,
1216			(unsigned long long)wqids[count].path,
1217			wqids[count].version);
1218
1219	if (nwname)
1220		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1221	else
1222		fid->qid = oldfid->qid;
1223
1224	kfree(wqids);
1225	return fid;
1226
1227clunk_fid:
1228	kfree(wqids);
1229	p9_client_clunk(fid);
1230	fid = NULL;
1231
1232error:
1233	if (fid && (fid != oldfid))
1234		p9_fid_destroy(fid);
1235
1236	return ERR_PTR(err);
1237}
1238EXPORT_SYMBOL(p9_client_walk);
1239
1240int p9_client_open(struct p9_fid *fid, int mode)
1241{
1242	int err;
1243	struct p9_client *clnt;
1244	struct p9_req_t *req;
1245	struct p9_qid qid;
1246	int iounit;
1247
1248	clnt = fid->clnt;
1249	p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1250		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1251	err = 0;
1252
1253	if (fid->mode != -1)
1254		return -EINVAL;
1255
1256	if (p9_is_proto_dotl(clnt))
1257		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1258	else
1259		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1260	if (IS_ERR(req)) {
1261		err = PTR_ERR(req);
1262		goto error;
1263	}
1264
1265	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1266	if (err) {
1267		trace_9p_protocol_dump(clnt, &req->rc);
1268		goto free_and_error;
1269	}
1270
1271	p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1272		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1273		(unsigned long long)qid.path, qid.version, iounit);
1274
1275	fid->mode = mode;
1276	fid->iounit = iounit;
1277
1278free_and_error:
1279	p9_tag_remove(clnt, req);
1280error:
1281	return err;
1282}
1283EXPORT_SYMBOL(p9_client_open);
1284
1285int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1286		kgid_t gid, struct p9_qid *qid)
1287{
1288	int err = 0;
1289	struct p9_client *clnt;
1290	struct p9_req_t *req;
1291	int iounit;
1292
1293	p9_debug(P9_DEBUG_9P,
1294			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1295			ofid->fid, name, flags, mode,
1296		 	from_kgid(&init_user_ns, gid));
1297	clnt = ofid->clnt;
1298
1299	if (ofid->mode != -1)
1300		return -EINVAL;
1301
1302	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1303			mode, gid);
1304	if (IS_ERR(req)) {
1305		err = PTR_ERR(req);
1306		goto error;
1307	}
1308
1309	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
1310	if (err) {
1311		trace_9p_protocol_dump(clnt, &req->rc);
1312		goto free_and_error;
1313	}
1314
1315	p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1316			qid->type,
1317			(unsigned long long)qid->path,
1318			qid->version, iounit);
1319
1320	ofid->mode = mode;
1321	ofid->iounit = iounit;
1322
1323free_and_error:
1324	p9_tag_remove(clnt, req);
1325error:
1326	return err;
1327}
1328EXPORT_SYMBOL(p9_client_create_dotl);
1329
1330int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1331		     char *extension)
1332{
1333	int err;
1334	struct p9_client *clnt;
1335	struct p9_req_t *req;
1336	struct p9_qid qid;
1337	int iounit;
1338
1339	p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1340						fid->fid, name, perm, mode);
1341	err = 0;
1342	clnt = fid->clnt;
1343
1344	if (fid->mode != -1)
1345		return -EINVAL;
1346
1347	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1348				mode, extension);
1349	if (IS_ERR(req)) {
1350		err = PTR_ERR(req);
1351		goto error;
1352	}
1353
1354	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1355	if (err) {
1356		trace_9p_protocol_dump(clnt, &req->rc);
1357		goto free_and_error;
1358	}
1359
1360	p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1361				qid.type,
1362				(unsigned long long)qid.path,
1363				qid.version, iounit);
1364
1365	fid->mode = mode;
1366	fid->iounit = iounit;
1367
1368free_and_error:
1369	p9_tag_remove(clnt, req);
1370error:
1371	return err;
1372}
1373EXPORT_SYMBOL(p9_client_fcreate);
1374
1375int p9_client_symlink(struct p9_fid *dfid, const char *name,
1376		const char *symtgt, kgid_t gid, struct p9_qid *qid)
1377{
1378	int err = 0;
1379	struct p9_client *clnt;
1380	struct p9_req_t *req;
1381
1382	p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1383			dfid->fid, name, symtgt);
1384	clnt = dfid->clnt;
1385
1386	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1387			gid);
1388	if (IS_ERR(req)) {
1389		err = PTR_ERR(req);
1390		goto error;
1391	}
1392
1393	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
1394	if (err) {
1395		trace_9p_protocol_dump(clnt, &req->rc);
1396		goto free_and_error;
1397	}
1398
1399	p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1400			qid->type, (unsigned long long)qid->path, qid->version);
1401
1402free_and_error:
1403	p9_tag_remove(clnt, req);
1404error:
1405	return err;
1406}
1407EXPORT_SYMBOL(p9_client_symlink);
1408
1409int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1410{
1411	struct p9_client *clnt;
1412	struct p9_req_t *req;
1413
1414	p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1415			dfid->fid, oldfid->fid, newname);
1416	clnt = dfid->clnt;
1417	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1418			newname);
1419	if (IS_ERR(req))
1420		return PTR_ERR(req);
1421
1422	p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1423	p9_tag_remove(clnt, req);
1424	return 0;
1425}
1426EXPORT_SYMBOL(p9_client_link);
1427
1428int p9_client_fsync(struct p9_fid *fid, int datasync)
1429{
1430	int err;
1431	struct p9_client *clnt;
1432	struct p9_req_t *req;
1433
1434	p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1435			fid->fid, datasync);
1436	err = 0;
1437	clnt = fid->clnt;
1438
1439	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1440	if (IS_ERR(req)) {
1441		err = PTR_ERR(req);
1442		goto error;
1443	}
1444
1445	p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1446
1447	p9_tag_remove(clnt, req);
1448
1449error:
1450	return err;
1451}
1452EXPORT_SYMBOL(p9_client_fsync);
1453
1454int p9_client_clunk(struct p9_fid *fid)
1455{
1456	int err;
1457	struct p9_client *clnt;
1458	struct p9_req_t *req;
1459	int retries = 0;
1460
1461	if (!fid) {
1462		pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1463			__func__, task_pid_nr(current));
1464		dump_stack();
1465		return 0;
1466	}
1467
1468again:
1469	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1470								retries);
1471	err = 0;
1472	clnt = fid->clnt;
1473
1474	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1475	if (IS_ERR(req)) {
1476		err = PTR_ERR(req);
1477		goto error;
1478	}
1479
1480	p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1481
1482	p9_tag_remove(clnt, req);
1483error:
1484	/*
1485	 * Fid is not valid even after a failed clunk
1486	 * If interrupted, retry once then give up and
1487	 * leak fid until umount.
1488	 */
1489	if (err == -ERESTARTSYS) {
1490		if (retries++ == 0)
1491			goto again;
1492	} else
1493		p9_fid_destroy(fid);
1494	return err;
1495}
1496EXPORT_SYMBOL(p9_client_clunk);
1497
1498int p9_client_remove(struct p9_fid *fid)
1499{
1500	int err;
1501	struct p9_client *clnt;
1502	struct p9_req_t *req;
1503
1504	p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1505	err = 0;
1506	clnt = fid->clnt;
1507
1508	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1509	if (IS_ERR(req)) {
1510		err = PTR_ERR(req);
1511		goto error;
1512	}
1513
1514	p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1515
1516	p9_tag_remove(clnt, req);
1517error:
1518	if (err == -ERESTARTSYS)
1519		p9_client_clunk(fid);
1520	else
1521		p9_fid_destroy(fid);
1522	return err;
1523}
1524EXPORT_SYMBOL(p9_client_remove);
1525
1526int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1527{
1528	int err = 0;
1529	struct p9_req_t *req;
1530	struct p9_client *clnt;
1531
1532	p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1533		   dfid->fid, name, flags);
1534
1535	clnt = dfid->clnt;
1536	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1537	if (IS_ERR(req)) {
1538		err = PTR_ERR(req);
1539		goto error;
1540	}
1541	p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1542
1543	p9_tag_remove(clnt, req);
1544error:
1545	return err;
1546}
1547EXPORT_SYMBOL(p9_client_unlinkat);
1548
1549int
1550p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1551{
1552	struct p9_client *clnt = fid->clnt;
1553	struct p9_req_t *req;
1554	int total = 0;
1555	*err = 0;
1556
1557	p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1558		   fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1559
1560	while (iov_iter_count(to)) {
1561		int count = iov_iter_count(to);
1562		int rsize, non_zc = 0;
1563		char *dataptr;
1564
1565		rsize = fid->iounit;
1566		if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1567			rsize = clnt->msize - P9_IOHDRSZ;
1568
1569		if (count < rsize)
1570			rsize = count;
1571
1572		/* Don't bother zerocopy for small IO (< 1024) */
1573		if (clnt->trans_mod->zc_request && rsize > 1024) {
1574			/*
1575			 * response header len is 11
1576			 * PDU Header(7) + IO Size (4)
1577			 */
1578			req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1579					       0, 11, "dqd", fid->fid,
1580					       offset, rsize);
1581		} else {
1582			non_zc = 1;
1583			req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1584					    rsize);
1585		}
1586		if (IS_ERR(req)) {
1587			*err = PTR_ERR(req);
1588			break;
1589		}
1590
1591		*err = p9pdu_readf(&req->rc, clnt->proto_version,
1592				   "D", &count, &dataptr);
1593		if (*err) {
1594			trace_9p_protocol_dump(clnt, &req->rc);
1595			p9_tag_remove(clnt, req);
1596			break;
1597		}
1598		if (rsize < count) {
1599			pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1600			count = rsize;
1601		}
1602
1603		p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1604		if (!count) {
1605			p9_tag_remove(clnt, req);
1606			break;
1607		}
1608
1609		if (non_zc) {
1610			int n = copy_to_iter(dataptr, count, to);
1611			total += n;
1612			offset += n;
1613			if (n != count) {
1614				*err = -EFAULT;
1615				p9_tag_remove(clnt, req);
1616				break;
1617			}
1618		} else {
1619			iov_iter_advance(to, count);
1620			total += count;
1621			offset += count;
1622		}
1623		p9_tag_remove(clnt, req);
1624	}
1625	return total;
1626}
1627EXPORT_SYMBOL(p9_client_read);
1628
1629int
1630p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1631{
1632	struct p9_client *clnt = fid->clnt;
1633	struct p9_req_t *req;
1634	int total = 0;
1635	*err = 0;
1636
1637	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1638				fid->fid, (unsigned long long) offset,
1639				iov_iter_count(from));
1640
1641	while (iov_iter_count(from)) {
1642		int count = iov_iter_count(from);
1643		int rsize = fid->iounit;
1644		if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1645			rsize = clnt->msize - P9_IOHDRSZ;
1646
1647		if (count < rsize)
1648			rsize = count;
1649
1650		/* Don't bother zerocopy for small IO (< 1024) */
1651		if (clnt->trans_mod->zc_request && rsize > 1024) {
1652			req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1653					       rsize, P9_ZC_HDR_SZ, "dqd",
1654					       fid->fid, offset, rsize);
1655		} else {
1656			req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1657						    offset, rsize, from);
1658		}
1659		if (IS_ERR(req)) {
1660			*err = PTR_ERR(req);
1661			break;
1662		}
1663
1664		*err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count);
1665		if (*err) {
1666			trace_9p_protocol_dump(clnt, &req->rc);
1667			p9_tag_remove(clnt, req);
1668			break;
1669		}
1670		if (rsize < count) {
1671			pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1672			count = rsize;
1673		}
1674
1675		p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1676
1677		p9_tag_remove(clnt, req);
1678		iov_iter_advance(from, count);
1679		total += count;
1680		offset += count;
1681	}
1682	return total;
1683}
1684EXPORT_SYMBOL(p9_client_write);
1685
1686struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1687{
1688	int err;
1689	struct p9_client *clnt;
1690	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1691	struct p9_req_t *req;
1692	u16 ignored;
1693
1694	p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1695
1696	if (!ret)
1697		return ERR_PTR(-ENOMEM);
1698
1699	err = 0;
1700	clnt = fid->clnt;
1701
1702	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1703	if (IS_ERR(req)) {
1704		err = PTR_ERR(req);
1705		goto error;
1706	}
1707
1708	err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
1709	if (err) {
1710		trace_9p_protocol_dump(clnt, &req->rc);
1711		p9_tag_remove(clnt, req);
1712		goto error;
1713	}
1714
1715	p9_debug(P9_DEBUG_9P,
1716		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1717		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1718		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1719		"<<<    uid=%d gid=%d n_muid=%d\n",
1720		ret->size, ret->type, ret->dev, ret->qid.type,
1721		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1722		ret->atime, ret->mtime, (unsigned long long)ret->length,
1723		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1724		from_kuid(&init_user_ns, ret->n_uid),
1725		from_kgid(&init_user_ns, ret->n_gid),
1726		from_kuid(&init_user_ns, ret->n_muid));
1727
1728	p9_tag_remove(clnt, req);
1729	return ret;
1730
1731error:
1732	kfree(ret);
1733	return ERR_PTR(err);
1734}
1735EXPORT_SYMBOL(p9_client_stat);
1736
1737struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1738							u64 request_mask)
1739{
1740	int err;
1741	struct p9_client *clnt;
1742	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1743								GFP_KERNEL);
1744	struct p9_req_t *req;
1745
1746	p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1747							fid->fid, request_mask);
1748
1749	if (!ret)
1750		return ERR_PTR(-ENOMEM);
1751
1752	err = 0;
1753	clnt = fid->clnt;
1754
1755	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1756	if (IS_ERR(req)) {
1757		err = PTR_ERR(req);
1758		goto error;
1759	}
1760
1761	err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
1762	if (err) {
1763		trace_9p_protocol_dump(clnt, &req->rc);
1764		p9_tag_remove(clnt, req);
1765		goto error;
1766	}
1767
1768	p9_debug(P9_DEBUG_9P,
1769		"<<< RGETATTR st_result_mask=%lld\n"
1770		"<<< qid=%x.%llx.%x\n"
1771		"<<< st_mode=%8.8x st_nlink=%llu\n"
1772		"<<< st_uid=%d st_gid=%d\n"
1773		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1774		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1775		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1776		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1777		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1778		"<<< st_gen=%lld st_data_version=%lld\n",
1779		ret->st_result_mask, ret->qid.type, ret->qid.path,
1780		ret->qid.version, ret->st_mode, ret->st_nlink,
1781		from_kuid(&init_user_ns, ret->st_uid),
1782		from_kgid(&init_user_ns, ret->st_gid),
1783		ret->st_rdev, ret->st_size, ret->st_blksize,
1784		ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1785		ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1786		ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1787		ret->st_gen, ret->st_data_version);
1788
1789	p9_tag_remove(clnt, req);
1790	return ret;
1791
1792error:
1793	kfree(ret);
1794	return ERR_PTR(err);
1795}
1796EXPORT_SYMBOL(p9_client_getattr_dotl);
1797
1798static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1799{
1800	int ret;
1801
1802	/* NOTE: size shouldn't include its own length */
1803	/* size[2] type[2] dev[4] qid[13] */
1804	/* mode[4] atime[4] mtime[4] length[8]*/
1805	/* name[s] uid[s] gid[s] muid[s] */
1806	ret = 2+4+13+4+4+4+8+2+2+2+2;
1807
1808	if (wst->name)
1809		ret += strlen(wst->name);
1810	if (wst->uid)
1811		ret += strlen(wst->uid);
1812	if (wst->gid)
1813		ret += strlen(wst->gid);
1814	if (wst->muid)
1815		ret += strlen(wst->muid);
1816
1817	if ((proto_version == p9_proto_2000u) ||
1818		(proto_version == p9_proto_2000L)) {
1819		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1820		if (wst->extension)
1821			ret += strlen(wst->extension);
1822	}
1823
1824	return ret;
1825}
1826
1827int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1828{
1829	int err;
1830	struct p9_req_t *req;
1831	struct p9_client *clnt;
1832
1833	err = 0;
1834	clnt = fid->clnt;
1835	wst->size = p9_client_statsize(wst, clnt->proto_version);
1836	p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1837	p9_debug(P9_DEBUG_9P,
1838		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1839		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1840		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1841		"     uid=%d gid=%d n_muid=%d\n",
1842		wst->size, wst->type, wst->dev, wst->qid.type,
1843		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1844		wst->atime, wst->mtime, (unsigned long long)wst->length,
1845		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1846		from_kuid(&init_user_ns, wst->n_uid),
1847		from_kgid(&init_user_ns, wst->n_gid),
1848		from_kuid(&init_user_ns, wst->n_muid));
1849
1850	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1851	if (IS_ERR(req)) {
1852		err = PTR_ERR(req);
1853		goto error;
1854	}
1855
1856	p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1857
1858	p9_tag_remove(clnt, req);
1859error:
1860	return err;
1861}
1862EXPORT_SYMBOL(p9_client_wstat);
1863
1864int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1865{
1866	int err;
1867	struct p9_req_t *req;
1868	struct p9_client *clnt;
1869
1870	err = 0;
1871	clnt = fid->clnt;
1872	p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1873	p9_debug(P9_DEBUG_9P,
1874		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1875		"    atime_sec=%lld atime_nsec=%lld\n"
1876		"    mtime_sec=%lld mtime_nsec=%lld\n",
1877		p9attr->valid, p9attr->mode,
1878		from_kuid(&init_user_ns, p9attr->uid),
1879		from_kgid(&init_user_ns, p9attr->gid),
1880		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1881		p9attr->mtime_sec, p9attr->mtime_nsec);
1882
1883	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1884
1885	if (IS_ERR(req)) {
1886		err = PTR_ERR(req);
1887		goto error;
1888	}
1889	p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1890	p9_tag_remove(clnt, req);
1891error:
1892	return err;
1893}
1894EXPORT_SYMBOL(p9_client_setattr);
1895
1896int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1897{
1898	int err;
1899	struct p9_req_t *req;
1900	struct p9_client *clnt;
1901
1902	err = 0;
1903	clnt = fid->clnt;
1904
1905	p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1906
1907	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1908	if (IS_ERR(req)) {
1909		err = PTR_ERR(req);
1910		goto error;
1911	}
1912
1913	err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1914			  &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1915			  &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1916	if (err) {
1917		trace_9p_protocol_dump(clnt, &req->rc);
1918		p9_tag_remove(clnt, req);
1919		goto error;
1920	}
1921
1922	p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1923		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1924		"fsid %llu namelen %ld\n",
1925		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1926		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1927		sb->fsid, (long int)sb->namelen);
1928
1929	p9_tag_remove(clnt, req);
1930error:
1931	return err;
1932}
1933EXPORT_SYMBOL(p9_client_statfs);
1934
1935int p9_client_rename(struct p9_fid *fid,
1936		     struct p9_fid *newdirfid, const char *name)
1937{
1938	int err;
1939	struct p9_req_t *req;
1940	struct p9_client *clnt;
1941
1942	err = 0;
1943	clnt = fid->clnt;
1944
1945	p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1946			fid->fid, newdirfid->fid, name);
1947
1948	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1949			newdirfid->fid, name);
1950	if (IS_ERR(req)) {
1951		err = PTR_ERR(req);
1952		goto error;
1953	}
1954
1955	p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1956
1957	p9_tag_remove(clnt, req);
1958error:
1959	return err;
1960}
1961EXPORT_SYMBOL(p9_client_rename);
1962
1963int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1964		       struct p9_fid *newdirfid, const char *new_name)
1965{
1966	int err;
1967	struct p9_req_t *req;
1968	struct p9_client *clnt;
1969
1970	err = 0;
1971	clnt = olddirfid->clnt;
1972
1973	p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1974		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1975		   newdirfid->fid, new_name);
1976
1977	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1978			    old_name, newdirfid->fid, new_name);
1979	if (IS_ERR(req)) {
1980		err = PTR_ERR(req);
1981		goto error;
1982	}
1983
1984	p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1985		   newdirfid->fid, new_name);
1986
1987	p9_tag_remove(clnt, req);
1988error:
1989	return err;
1990}
1991EXPORT_SYMBOL(p9_client_renameat);
1992
1993/*
1994 * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1995 */
1996struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1997				const char *attr_name, u64 *attr_size)
1998{
1999	int err;
2000	struct p9_req_t *req;
2001	struct p9_client *clnt;
2002	struct p9_fid *attr_fid;
2003
2004	err = 0;
2005	clnt = file_fid->clnt;
2006	attr_fid = p9_fid_create(clnt);
2007	if (!attr_fid) {
2008		err = -ENOMEM;
 
2009		goto error;
2010	}
2011	p9_debug(P9_DEBUG_9P,
2012		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2013		file_fid->fid, attr_fid->fid, attr_name);
2014
2015	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2016			file_fid->fid, attr_fid->fid, attr_name);
2017	if (IS_ERR(req)) {
2018		err = PTR_ERR(req);
2019		goto error;
2020	}
2021	err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
2022	if (err) {
2023		trace_9p_protocol_dump(clnt, &req->rc);
2024		p9_tag_remove(clnt, req);
2025		goto clunk_fid;
2026	}
2027	p9_tag_remove(clnt, req);
2028	p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2029		attr_fid->fid, *attr_size);
2030	return attr_fid;
2031clunk_fid:
2032	p9_client_clunk(attr_fid);
2033	attr_fid = NULL;
2034error:
2035	if (attr_fid && (attr_fid != file_fid))
2036		p9_fid_destroy(attr_fid);
2037
2038	return ERR_PTR(err);
2039}
2040EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2041
2042int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2043			u64 attr_size, int flags)
2044{
2045	int err;
2046	struct p9_req_t *req;
2047	struct p9_client *clnt;
2048
2049	p9_debug(P9_DEBUG_9P,
2050		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2051		fid->fid, name, (long long)attr_size, flags);
2052	err = 0;
2053	clnt = fid->clnt;
2054	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2055			fid->fid, name, attr_size, flags);
2056	if (IS_ERR(req)) {
2057		err = PTR_ERR(req);
2058		goto error;
2059	}
2060	p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2061	p9_tag_remove(clnt, req);
2062error:
2063	return err;
2064}
2065EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2066
2067int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2068{
2069	int err, rsize, non_zc = 0;
2070	struct p9_client *clnt;
2071	struct p9_req_t *req;
2072	char *dataptr;
2073	struct kvec kv = {.iov_base = data, .iov_len = count};
2074	struct iov_iter to;
2075
2076	iov_iter_kvec(&to, READ, &kv, 1, count);
2077
2078	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2079				fid->fid, (unsigned long long) offset, count);
2080
2081	err = 0;
2082	clnt = fid->clnt;
2083
2084	rsize = fid->iounit;
2085	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2086		rsize = clnt->msize - P9_READDIRHDRSZ;
2087
2088	if (count < rsize)
2089		rsize = count;
2090
2091	/* Don't bother zerocopy for small IO (< 1024) */
2092	if (clnt->trans_mod->zc_request && rsize > 1024) {
2093		/*
2094		 * response header len is 11
2095		 * PDU Header(7) + IO Size (4)
2096		 */
2097		req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2098				       11, "dqd", fid->fid, offset, rsize);
2099	} else {
2100		non_zc = 1;
2101		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2102				    offset, rsize);
2103	}
2104	if (IS_ERR(req)) {
2105		err = PTR_ERR(req);
2106		goto error;
2107	}
2108
2109	err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
2110	if (err) {
2111		trace_9p_protocol_dump(clnt, &req->rc);
2112		goto free_and_error;
2113	}
2114	if (rsize < count) {
2115		pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2116		count = rsize;
2117	}
2118
2119	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2120
2121	if (non_zc)
2122		memmove(data, dataptr, count);
2123
2124	p9_tag_remove(clnt, req);
2125	return count;
2126
2127free_and_error:
2128	p9_tag_remove(clnt, req);
2129error:
2130	return err;
2131}
2132EXPORT_SYMBOL(p9_client_readdir);
2133
2134int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2135			dev_t rdev, kgid_t gid, struct p9_qid *qid)
2136{
2137	int err;
2138	struct p9_client *clnt;
2139	struct p9_req_t *req;
2140
2141	err = 0;
2142	clnt = fid->clnt;
2143	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2144		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2145	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2146		MAJOR(rdev), MINOR(rdev), gid);
2147	if (IS_ERR(req))
2148		return PTR_ERR(req);
2149
2150	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2151	if (err) {
2152		trace_9p_protocol_dump(clnt, &req->rc);
2153		goto error;
2154	}
2155	p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2156				(unsigned long long)qid->path, qid->version);
2157
2158error:
2159	p9_tag_remove(clnt, req);
2160	return err;
2161
2162}
2163EXPORT_SYMBOL(p9_client_mknod_dotl);
2164
2165int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2166				kgid_t gid, struct p9_qid *qid)
2167{
2168	int err;
2169	struct p9_client *clnt;
2170	struct p9_req_t *req;
2171
2172	err = 0;
2173	clnt = fid->clnt;
2174	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2175		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2176	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2177		gid);
2178	if (IS_ERR(req))
2179		return PTR_ERR(req);
2180
2181	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2182	if (err) {
2183		trace_9p_protocol_dump(clnt, &req->rc);
2184		goto error;
2185	}
2186	p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2187				(unsigned long long)qid->path, qid->version);
2188
2189error:
2190	p9_tag_remove(clnt, req);
2191	return err;
2192
2193}
2194EXPORT_SYMBOL(p9_client_mkdir_dotl);
2195
2196int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2197{
2198	int err;
2199	struct p9_client *clnt;
2200	struct p9_req_t *req;
2201
2202	err = 0;
2203	clnt = fid->clnt;
2204	p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2205			"start %lld length %lld proc_id %d client_id %s\n",
2206			fid->fid, flock->type, flock->flags, flock->start,
2207			flock->length, flock->proc_id, flock->client_id);
2208
2209	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2210				flock->flags, flock->start, flock->length,
2211					flock->proc_id, flock->client_id);
2212
2213	if (IS_ERR(req))
2214		return PTR_ERR(req);
2215
2216	err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
2217	if (err) {
2218		trace_9p_protocol_dump(clnt, &req->rc);
2219		goto error;
2220	}
2221	p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2222error:
2223	p9_tag_remove(clnt, req);
2224	return err;
2225
2226}
2227EXPORT_SYMBOL(p9_client_lock_dotl);
2228
2229int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2230{
2231	int err;
2232	struct p9_client *clnt;
2233	struct p9_req_t *req;
2234
2235	err = 0;
2236	clnt = fid->clnt;
2237	p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2238		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2239		glock->start, glock->length, glock->proc_id, glock->client_id);
2240
2241	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2242		glock->start, glock->length, glock->proc_id, glock->client_id);
2243
2244	if (IS_ERR(req))
2245		return PTR_ERR(req);
2246
2247	err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type,
2248			  &glock->start, &glock->length, &glock->proc_id,
2249			  &glock->client_id);
2250	if (err) {
2251		trace_9p_protocol_dump(clnt, &req->rc);
2252		goto error;
2253	}
2254	p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2255		"proc_id %d client_id %s\n", glock->type, glock->start,
2256		glock->length, glock->proc_id, glock->client_id);
2257error:
2258	p9_tag_remove(clnt, req);
2259	return err;
2260}
2261EXPORT_SYMBOL(p9_client_getlock_dotl);
2262
2263int p9_client_readlink(struct p9_fid *fid, char **target)
2264{
2265	int err;
2266	struct p9_client *clnt;
2267	struct p9_req_t *req;
2268
2269	err = 0;
2270	clnt = fid->clnt;
2271	p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2272
2273	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2274	if (IS_ERR(req))
2275		return PTR_ERR(req);
2276
2277	err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
2278	if (err) {
2279		trace_9p_protocol_dump(clnt, &req->rc);
2280		goto error;
2281	}
2282	p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2283error:
2284	p9_tag_remove(clnt, req);
2285	return err;
2286}
2287EXPORT_SYMBOL(p9_client_readlink);
2288
2289int __init p9_client_init(void)
2290{
2291	p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU);
2292	return p9_req_cache ? 0 : -ENOMEM;
2293}
2294
2295void __exit p9_client_exit(void)
2296{
2297	kmem_cache_destroy(p9_req_cache);
2298}