client.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * 9P Client
   4 *
   5 *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   6 *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   7 */
   8
   9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11#include <linux/module.h>
  12#include <linux/errno.h>
  13#include <linux/fs.h>
  14#include <linux/poll.h>
  15#include <linux/idr.h>
  16#include <linux/mutex.h>
  17#include <linux/slab.h>
  18#include <linux/sched/signal.h>
  19#include <linux/uaccess.h>
  20#include <linux/uio.h>
  21#include <linux/netfs.h>
  22#include <net/9p/9p.h>
  23#include <linux/seq_file.h>
  24#include <linux/fs_context.h>
  25#include <net/9p/client.h>
  26#include <net/9p/transport.h>
  27#include "protocol.h"
  28
  29#define CREATE_TRACE_POINTS
  30#include <trace/events/9p.h>
  31
  32/* Client Option Parsing (code inspired by NFS code)
  33 *  - a little lazy - parse all client options
  34 */
  35
  36inline int p9_is_proto_dotl(struct p9_client *clnt)
  37{
  38	return clnt->proto_version == p9_proto_2000L;
  39}
  40EXPORT_SYMBOL(p9_is_proto_dotl);
  41
  42inline int p9_is_proto_dotu(struct p9_client *clnt)
  43{
  44	return clnt->proto_version == p9_proto_2000u;
  45}
  46EXPORT_SYMBOL(p9_is_proto_dotu);
  47
  48int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
  49{
  50	if (clnt->msize != DEFAULT_MSIZE)
  51		seq_printf(m, ",msize=%u", clnt->msize);
  52	seq_printf(m, ",trans=%s", clnt->trans_mod->name);
  53
  54	switch (clnt->proto_version) {
  55	case p9_proto_legacy:
  56		seq_puts(m, ",noextend");
  57		break;
  58	case p9_proto_2000u:
  59		seq_puts(m, ",version=9p2000.u");
  60		break;
  61	case p9_proto_2000L:
  62		/* Default */
  63		break;
  64	}
  65
  66	if (clnt->trans_mod->show_options)
  67		return clnt->trans_mod->show_options(m, clnt);
  68	return 0;
  69}
  70EXPORT_SYMBOL(p9_show_client_options);
  71
  72/* Some error codes are taken directly from the server replies,
  73 * make sure they are valid.
  74 */
  75static int safe_errno(int err)
  76{
  77	if (err > 0 || err < -MAX_ERRNO) {
  78		p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
  79		return -EPROTO;
  80	}
  81	return err;
  82}
  83
  84static int apply_client_options(struct p9_client *clnt, struct fs_context *fc)
  85{
  86	struct v9fs_context *ctx = fc->fs_private;
  87
  88	clnt->msize = ctx->client_opts.msize;
  89	clnt->trans_mod = ctx->client_opts.trans_mod;
  90	ctx->client_opts.trans_mod = NULL;
  91	clnt->proto_version = ctx->client_opts.proto_version;
  92
  93	return 0;
  94}
  95
  96static int p9_fcall_init(struct p9_client *c, struct p9_fcall *fc,
  97			 int alloc_msize)
  98{
  99	if (likely(c->fcall_cache) && alloc_msize == c->msize) {
 100		fc->sdata = kmem_cache_alloc(c->fcall_cache, GFP_NOFS);
 101		fc->cache = c->fcall_cache;
 102		if (!fc->sdata && c->trans_mod->supports_vmalloc) {
 103			fc->sdata = kvmalloc(alloc_msize, GFP_NOFS);
 104			fc->cache = NULL;
 105		}
 106	} else {
 107		if (c->trans_mod->supports_vmalloc)
 108			fc->sdata = kvmalloc(alloc_msize, GFP_NOFS);
 109		else
 110			fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
 111		fc->cache = NULL;
 112	}
 113	if (!fc->sdata)
 114		return -ENOMEM;
 115	fc->capacity = alloc_msize;
 116	fc->id = 0;
 117	fc->tag = P9_NOTAG;
 118	return 0;
 119}
 120
 121void p9_fcall_fini(struct p9_fcall *fc)
 122{
 123	/* sdata can be NULL for interrupted requests in trans_rdma,
 124	 * and kmem_cache_free does not do NULL-check for us
 125	 */
 126	if (unlikely(!fc->sdata))
 127		return;
 128
 129	if (fc->cache)
 130		kmem_cache_free(fc->cache, fc->sdata);
 131	else
 132		kvfree(fc->sdata);
 133}
 134EXPORT_SYMBOL(p9_fcall_fini);
 135
 136static struct kmem_cache *p9_req_cache;
 137
 138/**
 139 * p9_tag_alloc - Allocate a new request.
 140 * @c: Client session.
 141 * @type: Transaction type.
 142 * @t_size: Buffer size for holding this request
 143 * (automatic calculation by format template if 0).
 144 * @r_size: Buffer size for holding server's reply on this request
 145 * (automatic calculation by format template if 0).
 146 * @fmt: Format template for assembling 9p request message
 147 * (see p9pdu_vwritef).
 148 * @ap: Variable arguments to be fed to passed format template
 149 * (see p9pdu_vwritef).
 150 *
 151 * Context: Process context.
 152 * Return: Pointer to new request.
 153 */
 154static struct p9_req_t *
 155p9_tag_alloc(struct p9_client *c, int8_t type, uint t_size, uint r_size,
 156	      const char *fmt, va_list ap)
 157{
 158	struct p9_req_t *req = kmem_cache_alloc(p9_req_cache, GFP_NOFS);
 159	int alloc_tsize;
 160	int alloc_rsize;
 161	int tag;
 162	va_list apc;
 163
 164	va_copy(apc, ap);
 165	alloc_tsize = min_t(size_t, c->msize,
 166			    t_size ?: p9_msg_buf_size(c, type, fmt, apc));
 167	va_end(apc);
 168
 169	alloc_rsize = min_t(size_t, c->msize,
 170			    r_size ?: p9_msg_buf_size(c, type + 1, fmt, ap));
 171
 172	if (!req)
 173		return ERR_PTR(-ENOMEM);
 174
 175	if (p9_fcall_init(c, &req->tc, alloc_tsize))
 176		goto free_req;
 177	if (p9_fcall_init(c, &req->rc, alloc_rsize))
 178		goto free;
 179
 180	p9pdu_reset(&req->tc);
 181	p9pdu_reset(&req->rc);
 182	req->t_err = 0;
 183	req->status = REQ_STATUS_ALLOC;
 184	/* refcount needs to be set to 0 before inserting into the idr
 185	 * so p9_tag_lookup does not accept a request that is not fully
 186	 * initialized. refcount_set to 2 below will mark request ready.
 187	 */
 188	refcount_set(&req->refcount, 0);
 189	init_waitqueue_head(&req->wq);
 190	INIT_LIST_HEAD(&req->req_list);
 191
 192	idr_preload(GFP_NOFS);
 193	spin_lock_irq(&c->lock);
 194	if (type == P9_TVERSION)
 195		tag = idr_alloc(&c->reqs, req, P9_NOTAG, P9_NOTAG + 1,
 196				GFP_NOWAIT);
 197	else
 198		tag = idr_alloc(&c->reqs, req, 0, P9_NOTAG, GFP_NOWAIT);
 199	req->tc.tag = tag;
 200	spin_unlock_irq(&c->lock);
 201	idr_preload_end();
 202	if (tag < 0)
 203		goto free;
 204
 205	/* Init ref to two because in the general case there is one ref
 206	 * that is put asynchronously by a writer thread, one ref
 207	 * temporarily given by p9_tag_lookup and put by p9_client_cb
 208	 * in the recv thread, and one ref put by p9_req_put in the
 209	 * main thread. The only exception is virtio that does not use
 210	 * p9_tag_lookup but does not have a writer thread either
 211	 * (the write happens synchronously in the request/zc_request
 212	 * callback), so p9_client_cb eats the second ref there
 213	 * as the pointer is duplicated directly by virtqueue_add_sgs()
 214	 */
 215	refcount_set(&req->refcount, 2);
 216
 217	return req;
 218
 219free:
 220	p9_fcall_fini(&req->tc);
 221	p9_fcall_fini(&req->rc);
 222free_req:
 223	kmem_cache_free(p9_req_cache, req);
 224	return ERR_PTR(-ENOMEM);
 225}
 226
 227/**
 228 * p9_tag_lookup - Look up a request by tag.
 229 * @c: Client session.
 230 * @tag: Transaction ID.
 231 *
 232 * Context: Any context.
 233 * Return: A request, or %NULL if there is no request with that tag.
 234 */
 235struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 236{
 237	struct p9_req_t *req;
 238
 239	rcu_read_lock();
 240again:
 241	req = idr_find(&c->reqs, tag);
 242	if (req) {
 243		/* We have to be careful with the req found under rcu_read_lock
 244		 * Thanks to SLAB_TYPESAFE_BY_RCU we can safely try to get the
 245		 * ref again without corrupting other data, then check again
 246		 * that the tag matches once we have the ref
 247		 */
 248		if (!p9_req_try_get(req))
 249			goto again;
 250		if (req->tc.tag != tag) {
 251			p9_req_put(c, req);
 252			goto again;
 253		}
 254	}
 255	rcu_read_unlock();
 256
 257	return req;
 258}
 259EXPORT_SYMBOL(p9_tag_lookup);
 260
 261/**
 262 * p9_tag_remove - Remove a tag.
 263 * @c: Client session.
 264 * @r: Request of reference.
 265 *
 266 * Context: Any context.
 267 */
 268static void p9_tag_remove(struct p9_client *c, struct p9_req_t *r)
 269{
 270	unsigned long flags;
 271	u16 tag = r->tc.tag;
 272
 273	p9_debug(P9_DEBUG_MUX, "freeing clnt %p req %p tag: %d\n", c, r, tag);
 274	spin_lock_irqsave(&c->lock, flags);
 275	idr_remove(&c->reqs, tag);
 276	spin_unlock_irqrestore(&c->lock, flags);
 277}
 278
 279int p9_req_put(struct p9_client *c, struct p9_req_t *r)
 280{
 281	if (refcount_dec_and_test(&r->refcount)) {
 282		p9_tag_remove(c, r);
 283
 284		p9_fcall_fini(&r->tc);
 285		p9_fcall_fini(&r->rc);
 286		kmem_cache_free(p9_req_cache, r);
 287		return 1;
 288	}
 289	return 0;
 290}
 291EXPORT_SYMBOL(p9_req_put);
 292
 293/**
 294 * p9_tag_cleanup - cleans up tags structure and reclaims resources
 295 * @c:  v9fs client struct
 296 *
 297 * This frees resources associated with the tags structure
 298 *
 299 */
 300static void p9_tag_cleanup(struct p9_client *c)
 301{
 302	struct p9_req_t *req;
 303	int id;
 304
 305	rcu_read_lock();
 306	idr_for_each_entry(&c->reqs, req, id) {
 307		pr_info("Tag %d still in use\n", id);
 308		if (p9_req_put(c, req) == 0)
 309			pr_warn("Packet with tag %d has still references",
 310				req->tc.tag);
 311	}
 312	rcu_read_unlock();
 313}
 314
 315/**
 316 * p9_client_cb - call back from transport to client
 317 * @c: client state
 318 * @req: request received
 319 * @status: request status, one of REQ_STATUS_*
 320 *
 321 */
 322void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
 323{
 324	p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc.tag);
 325
 326	/* This barrier is needed to make sure any change made to req before
 327	 * the status change is visible to another thread
 328	 */
 329	smp_wmb();
 330	WRITE_ONCE(req->status, status);
 331
 332	wake_up(&req->wq);
 333	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc.tag);
 334	p9_req_put(c, req);
 335}
 336EXPORT_SYMBOL(p9_client_cb);
 337
 338/**
 339 * p9_parse_header - parse header arguments out of a packet
 340 * @pdu: packet to parse
 341 * @size: size of packet
 342 * @type: type of request
 343 * @tag: tag of packet
 344 * @rewind: set if we need to rewind offset afterwards
 345 */
 346
 347int
 348p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type,
 349		int16_t *tag, int rewind)
 350{
 351	s8 r_type;
 352	s16 r_tag;
 353	s32 r_size;
 354	int offset = pdu->offset;
 355	int err;
 356
 357	pdu->offset = 0;
 358
 359	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 360	if (err)
 361		goto rewind_and_exit;
 362
 363	if (type)
 364		*type = r_type;
 365	if (tag)
 366		*tag = r_tag;
 367	if (size)
 368		*size = r_size;
 369
 370	if (pdu->size != r_size || r_size < 7) {
 371		err = -EINVAL;
 372		goto rewind_and_exit;
 373	}
 374
 375	pdu->id = r_type;
 376	pdu->tag = r_tag;
 377
 378	p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
 379		 pdu->size, pdu->id, pdu->tag);
 380
 381rewind_and_exit:
 382	if (rewind)
 383		pdu->offset = offset;
 384	return err;
 385}
 386EXPORT_SYMBOL(p9_parse_header);
 387
 388/**
 389 * p9_check_errors - check 9p packet for error return and process it
 390 * @c: current client instance
 391 * @req: request to parse and check for error conditions
 392 *
 393 * returns error code if one is discovered, otherwise returns 0
 394 *
 395 * this will have to be more complicated if we have multiple
 396 * error packet types
 397 */
 398
 399static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 400{
 401	s8 type;
 402	int err;
 403	int ecode;
 404
 405	err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
 406	if (req->rc.size > req->rc.capacity && !req->rc.zc) {
 407		pr_err("requested packet size too big: %d does not fit %zu (type=%d)\n",
 408		       req->rc.size, req->rc.capacity, req->rc.id);
 409		return -EIO;
 410	}
 411	/* dump the response from server
 412	 * This should be after check errors which poplulate pdu_fcall.
 413	 */
 414	trace_9p_protocol_dump(c, &req->rc);
 415	if (err) {
 416		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 417		return err;
 418	}
 419	if (type != P9_RERROR && type != P9_RLERROR)
 420		return 0;
 421
 422	if (!p9_is_proto_dotl(c)) {
 423		char *ename = NULL;
 424
 425		err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
 426				  &ename, &ecode);
 427		if (err) {
 428			kfree(ename);
 429			goto out_err;
 430		}
 431
 432		if (p9_is_proto_dotu(c) && ecode < 512)
 433			err = -ecode;
 434
 435		if (!err) {
 436			err = p9_errstr2errno(ename, strlen(ename));
 437
 438			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
 439				 -ecode, ename);
 440		}
 441		kfree(ename);
 442	} else {
 443		err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
 444		if (err)
 445			goto out_err;
 446		err = -ecode;
 447
 448		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
 449	}
 450
 451	return err;
 452
 453out_err:
 454	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
 455
 456	return err;
 457}
 458
 459static struct p9_req_t *
 460p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 461
 462/**
 463 * p9_client_flush - flush (cancel) a request
 464 * @c: client state
 465 * @oldreq: request to cancel
 466 *
 467 * This sents a flush for a particular request and links
 468 * the flush request to the original request.  The current
 469 * code only supports a single flush request although the protocol
 470 * allows for multiple flush requests to be sent for a single request.
 471 *
 472 */
 473
 474static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 475{
 476	struct p9_req_t *req;
 477	s16 oldtag;
 478	int err;
 479
 480	err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
 481	if (err)
 482		return err;
 483
 484	p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 485
 486	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 487	if (IS_ERR(req))
 488		return PTR_ERR(req);
 489
 490	/* if we haven't received a response for oldreq,
 491	 * remove it from the list
 492	 */
 493	if (READ_ONCE(oldreq->status) == REQ_STATUS_SENT) {
 494		if (c->trans_mod->cancelled)
 495			c->trans_mod->cancelled(c, oldreq);
 496	}
 497
 498	p9_req_put(c, req);
 499	return 0;
 500}
 501
 502static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
 503					      int8_t type, uint t_size, uint r_size,
 504					      const char *fmt, va_list ap)
 505{
 506	int err;
 507	struct p9_req_t *req;
 508	va_list apc;
 509
 510	p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 511
 512	/* we allow for any status other than disconnected */
 513	if (c->status == Disconnected)
 514		return ERR_PTR(-EIO);
 515
 516	/* if status is begin_disconnected we allow only clunk request */
 517	if (c->status == BeginDisconnect && type != P9_TCLUNK)
 518		return ERR_PTR(-EIO);
 519
 520	va_copy(apc, ap);
 521	req = p9_tag_alloc(c, type, t_size, r_size, fmt, apc);
 522	va_end(apc);
 523	if (IS_ERR(req))
 524		return req;
 525
 526	/* marshall the data */
 527	p9pdu_prepare(&req->tc, req->tc.tag, type);
 528	err = p9pdu_vwritef(&req->tc, c->proto_version, fmt, ap);
 529	if (err)
 530		goto reterr;
 531	p9pdu_finalize(c, &req->tc);
 532	trace_9p_client_req(c, type, req->tc.tag);
 533	return req;
 534reterr:
 535	p9_req_put(c, req);
 536	/* We have to put also the 2nd reference as it won't be used */
 537	p9_req_put(c, req);
 538	return ERR_PTR(err);
 539}
 540
 541/**
 542 * p9_client_rpc - issue a request and wait for a response
 543 * @c: client session
 544 * @type: type of request
 545 * @fmt: protocol format string (see protocol.c)
 546 *
 547 * Returns request structure (which client must free using p9_req_put)
 548 */
 549
 550static struct p9_req_t *
 551p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 552{
 553	va_list ap;
 554	int sigpending, err;
 555	unsigned long flags;
 556	struct p9_req_t *req;
 557	/* Passing zero for tsize/rsize to p9_client_prepare_req() tells it to
 558	 * auto determine an appropriate (small) request/response size
 559	 * according to actual message data being sent. Currently RDMA
 560	 * transport is excluded from this response message size optimization,
 561	 * as it would not cope with it, due to its pooled response buffers
 562	 * (using an optimized request size for RDMA as well though).
 563	 */
 564	const uint tsize = 0;
 565	const uint rsize = c->trans_mod->pooled_rbuffers ? c->msize : 0;
 566
 567	va_start(ap, fmt);
 568	req = p9_client_prepare_req(c, type, tsize, rsize, fmt, ap);
 569	va_end(ap);
 570	if (IS_ERR(req))
 571		return req;
 572
 573	req->tc.zc = false;
 574	req->rc.zc = false;
 575
 576	if (signal_pending(current)) {
 577		sigpending = 1;
 578		clear_thread_flag(TIF_SIGPENDING);
 579	} else {
 580		sigpending = 0;
 581	}
 582
 583	err = c->trans_mod->request(c, req);
 584	if (err < 0) {
 585		/* write won't happen */
 586		p9_req_put(c, req);
 587		if (err != -ERESTARTSYS && err != -EFAULT)
 588			c->status = Disconnected;
 589		goto recalc_sigpending;
 590	}
 591again:
 592	/* Wait for the response */
 593	err = wait_event_killable(req->wq,
 594				  READ_ONCE(req->status) >= REQ_STATUS_RCVD);
 595
 596	/* Make sure our req is coherent with regard to updates in other
 597	 * threads - echoes to wmb() in the callback
 598	 */
 599	smp_rmb();
 600
 601	if (err == -ERESTARTSYS && c->status == Connected &&
 602	    type == P9_TFLUSH) {
 603		sigpending = 1;
 604		clear_thread_flag(TIF_SIGPENDING);
 605		goto again;
 606	}
 607
 608	if (READ_ONCE(req->status) == REQ_STATUS_ERROR) {
 609		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 610		err = req->t_err;
 611	}
 612	if (err == -ERESTARTSYS && c->status == Connected) {
 613		p9_debug(P9_DEBUG_MUX, "flushing\n");
 614		sigpending = 1;
 615		clear_thread_flag(TIF_SIGPENDING);
 616
 617		if (c->trans_mod->cancel(c, req))
 618			p9_client_flush(c, req);
 619
 620		/* if we received the response anyway, don't signal error */
 621		if (READ_ONCE(req->status) == REQ_STATUS_RCVD)
 622			err = 0;
 623	}
 624recalc_sigpending:
 625	if (sigpending) {
 626		spin_lock_irqsave(&current->sighand->siglock, flags);
 627		recalc_sigpending();
 628		spin_unlock_irqrestore(&current->sighand->siglock, flags);
 629	}
 630	if (err < 0)
 631		goto reterr;
 632
 633	err = p9_check_errors(c, req);
 634	trace_9p_client_res(c, type, req->rc.tag, err);
 635	if (!err)
 636		return req;
 637reterr:
 638	p9_req_put(c, req);
 639	return ERR_PTR(safe_errno(err));
 640}
 641
 642/**
 643 * p9_client_zc_rpc - issue a request and wait for a response
 644 * @c: client session
 645 * @type: type of request
 646 * @uidata: destination for zero copy read
 647 * @uodata: source for zero copy write
 648 * @inlen: read buffer size
 649 * @olen: write buffer size
 650 * @in_hdrlen: reader header size, This is the size of response protocol data
 651 * @fmt: protocol format string (see protocol.c)
 652 *
 653 * Returns request structure (which client must free using p9_req_put)
 654 */
 655static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
 656					 struct iov_iter *uidata,
 657					 struct iov_iter *uodata,
 658					 int inlen, int olen, int in_hdrlen,
 659					 const char *fmt, ...)
 660{
 661	va_list ap;
 662	int sigpending, err;
 663	unsigned long flags;
 664	struct p9_req_t *req;
 665
 666	va_start(ap, fmt);
 667	/* We allocate a inline protocol data of only 4k bytes.
 668	 * The actual content is passed in zero-copy fashion.
 669	 */
 670	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, P9_ZC_HDR_SZ, fmt, ap);
 671	va_end(ap);
 672	if (IS_ERR(req))
 673		return req;
 674
 675	req->tc.zc = true;
 676	req->rc.zc = true;
 677
 678	if (signal_pending(current)) {
 679		sigpending = 1;
 680		clear_thread_flag(TIF_SIGPENDING);
 681	} else {
 682		sigpending = 0;
 683	}
 684
 685	err = c->trans_mod->zc_request(c, req, uidata, uodata,
 686				       inlen, olen, in_hdrlen);
 687	if (err < 0) {
 688		if (err == -EIO)
 689			c->status = Disconnected;
 690		if (err != -ERESTARTSYS)
 691			goto recalc_sigpending;
 692	}
 693	if (READ_ONCE(req->status) == REQ_STATUS_ERROR) {
 694		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 695		err = req->t_err;
 696	}
 697	if (err == -ERESTARTSYS && c->status == Connected) {
 698		p9_debug(P9_DEBUG_MUX, "flushing\n");
 699		sigpending = 1;
 700		clear_thread_flag(TIF_SIGPENDING);
 701
 702		if (c->trans_mod->cancel(c, req))
 703			p9_client_flush(c, req);
 704
 705		/* if we received the response anyway, don't signal error */
 706		if (READ_ONCE(req->status) == REQ_STATUS_RCVD)
 707			err = 0;
 708	}
 709recalc_sigpending:
 710	if (sigpending) {
 711		spin_lock_irqsave(&current->sighand->siglock, flags);
 712		recalc_sigpending();
 713		spin_unlock_irqrestore(&current->sighand->siglock, flags);
 714	}
 715	if (err < 0)
 716		goto reterr;
 717
 718	err = p9_check_errors(c, req);
 719	trace_9p_client_res(c, type, req->rc.tag, err);
 720	if (!err)
 721		return req;
 722reterr:
 723	p9_req_put(c, req);
 724	return ERR_PTR(safe_errno(err));
 725}
 726
 727static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 728{
 729	int ret;
 730	struct p9_fid *fid;
 731
 732	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
 733	fid = kzalloc(sizeof(*fid), GFP_KERNEL);
 734	if (!fid)
 735		return NULL;
 736
 737	fid->mode = -1;
 738	fid->uid = current_fsuid();
 739	fid->clnt = clnt;
 740	refcount_set(&fid->count, 1);
 741
 742	idr_preload(GFP_KERNEL);
 743	spin_lock_irq(&clnt->lock);
 744	ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
 745			    GFP_NOWAIT);
 746	spin_unlock_irq(&clnt->lock);
 747	idr_preload_end();
 748	if (!ret) {
 749		trace_9p_fid_ref(fid, P9_FID_REF_CREATE);
 750		return fid;
 751	}
 752
 753	kfree(fid);
 754	return NULL;
 755}
 756
 757static void p9_fid_destroy(struct p9_fid *fid)
 758{
 759	struct p9_client *clnt;
 760	unsigned long flags;
 761
 762	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
 763	trace_9p_fid_ref(fid, P9_FID_REF_DESTROY);
 764	clnt = fid->clnt;
 765	spin_lock_irqsave(&clnt->lock, flags);
 766	idr_remove(&clnt->fids, fid->fid);
 767	spin_unlock_irqrestore(&clnt->lock, flags);
 768	kfree(fid->rdir);
 769	kfree(fid);
 770}
 771
 772/* We also need to export tracepoint symbols for tracepoint_enabled() */
 773EXPORT_TRACEPOINT_SYMBOL(9p_fid_ref);
 774
 775void do_trace_9p_fid_get(struct p9_fid *fid)
 776{
 777	trace_9p_fid_ref(fid, P9_FID_REF_GET);
 778}
 779EXPORT_SYMBOL(do_trace_9p_fid_get);
 780
 781void do_trace_9p_fid_put(struct p9_fid *fid)
 782{
 783	trace_9p_fid_ref(fid, P9_FID_REF_PUT);
 784}
 785EXPORT_SYMBOL(do_trace_9p_fid_put);
 786
 787static int p9_client_version(struct p9_client *c)
 788{
 789	int err;
 790	struct p9_req_t *req;
 791	char *version = NULL;
 792	int msize;
 793
 794	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
 795		 c->msize, c->proto_version);
 796
 797	switch (c->proto_version) {
 798	case p9_proto_2000L:
 799		req = p9_client_rpc(c, P9_TVERSION, "ds",
 800				    c->msize, "9P2000.L");
 801		break;
 802	case p9_proto_2000u:
 803		req = p9_client_rpc(c, P9_TVERSION, "ds",
 804				    c->msize, "9P2000.u");
 805		break;
 806	case p9_proto_legacy:
 807		req = p9_client_rpc(c, P9_TVERSION, "ds",
 808				    c->msize, "9P2000");
 809		break;
 810	default:
 811		return -EINVAL;
 812	}
 813
 814	if (IS_ERR(req))
 815		return PTR_ERR(req);
 816
 817	err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version);
 818	if (err) {
 819		p9_debug(P9_DEBUG_9P, "version error %d\n", err);
 820		trace_9p_protocol_dump(c, &req->rc);
 821		goto error;
 822	}
 823
 824	p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 825	if (!strncmp(version, "9P2000.L", 8)) {
 826		c->proto_version = p9_proto_2000L;
 827	} else if (!strncmp(version, "9P2000.u", 8)) {
 828		c->proto_version = p9_proto_2000u;
 829	} else if (!strncmp(version, "9P2000", 6)) {
 830		c->proto_version = p9_proto_legacy;
 831	} else {
 832		p9_debug(P9_DEBUG_ERROR,
 833			 "server returned an unknown version: %s\n", version);
 834		err = -EREMOTEIO;
 835		goto error;
 836	}
 837
 838	if (msize < 4096) {
 839		p9_debug(P9_DEBUG_ERROR,
 840			 "server returned a msize < 4096: %d\n", msize);
 841		err = -EREMOTEIO;
 842		goto error;
 843	}
 844	if (msize < c->msize)
 845		c->msize = msize;
 846
 847error:
 848	kfree(version);
 849	p9_req_put(c, req);
 850
 851	return err;
 852}
 853
 854struct p9_client *p9_client_create(struct fs_context *fc)
 855{
 856	int err;
 857	static atomic_t seqno = ATOMIC_INIT(0);
 858	struct p9_client *clnt;
 859	char *client_id;
 860	char *cache_name;
 861
 862	clnt = kmalloc(sizeof(*clnt), GFP_KERNEL);
 863	if (!clnt)
 864		return ERR_PTR(-ENOMEM);
 865
 866	clnt->trans_mod = NULL;
 867	clnt->trans = NULL;
 868	clnt->fcall_cache = NULL;
 869
 870	client_id = utsname()->nodename;
 871	memcpy(clnt->name, client_id, strlen(client_id) + 1);
 872
 873	spin_lock_init(&clnt->lock);
 874	idr_init(&clnt->fids);
 875	idr_init(&clnt->reqs);
 876
 877	err = apply_client_options(clnt, fc);
 878	if (err)
 879		goto free_client;
 880
 881	if (!clnt->trans_mod)
 882		clnt->trans_mod = v9fs_get_default_trans();
 883
 884	if (!clnt->trans_mod) {
 885		err = -EPROTONOSUPPORT;
 886		p9_debug(P9_DEBUG_ERROR,
 887			 "No transport defined or default transport\n");
 888		goto free_client;
 889	}
 890
 891	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
 892		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
 893
 894	err = clnt->trans_mod->create(clnt, fc);
 895	if (err)
 896		goto put_trans;
 897
 898	if (clnt->msize > clnt->trans_mod->maxsize) {
 899		clnt->msize = clnt->trans_mod->maxsize;
 900		pr_info("Limiting 'msize' to %d as this is the maximum "
 901			"supported by transport %s\n",
 902			clnt->msize, clnt->trans_mod->name
 903		);
 904	}
 905
 906	if (clnt->msize < 4096) {
 907		p9_debug(P9_DEBUG_ERROR,
 908			 "Please specify a msize of at least 4k\n");
 909		err = -EINVAL;
 910		goto close_trans;
 911	}
 912
 913	err = p9_client_version(clnt);
 914	if (err)
 915		goto close_trans;
 916
 917	cache_name = kasprintf(GFP_KERNEL,
 918		"9p-fcall-cache-%u", atomic_inc_return(&seqno));
 919	if (!cache_name) {
 920		err = -ENOMEM;
 921		goto close_trans;
 922	}
 923
 924	/* P9_HDRSZ + 4 is the smallest packet header we can have that is
 925	 * followed by data accessed from userspace by read
 926	 */
 927	clnt->fcall_cache =
 928		kmem_cache_create_usercopy(cache_name, clnt->msize,
 929					   0, 0, P9_HDRSZ + 4,
 930					   clnt->msize - (P9_HDRSZ + 4),
 931					   NULL);
 932
 933	kfree(cache_name);
 934	return clnt;
 935
 936close_trans:
 937	clnt->trans_mod->close(clnt);
 938put_trans:
 939	v9fs_put_trans(clnt->trans_mod);
 940free_client:
 941	kfree(clnt);
 942	return ERR_PTR(err);
 943}
 944EXPORT_SYMBOL(p9_client_create);
 945
 946void p9_client_destroy(struct p9_client *clnt)
 947{
 948	struct p9_fid *fid;
 949	int id;
 950
 951	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
 952
 953	if (clnt->trans_mod)
 954		clnt->trans_mod->close(clnt);
 955
 956	v9fs_put_trans(clnt->trans_mod);
 957
 958	idr_for_each_entry(&clnt->fids, fid, id) {
 959		pr_info("Found fid %d not clunked\n", fid->fid);
 960		p9_fid_destroy(fid);
 961	}
 962
 963	p9_tag_cleanup(clnt);
 964
 965	kmem_cache_destroy(clnt->fcall_cache);
 966	kfree(clnt);
 967}
 968EXPORT_SYMBOL(p9_client_destroy);
 969
 970void p9_client_disconnect(struct p9_client *clnt)
 971{
 972	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
 973	clnt->status = Disconnected;
 974}
 975EXPORT_SYMBOL(p9_client_disconnect);
 976
 977void p9_client_begin_disconnect(struct p9_client *clnt)
 978{
 979	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
 980	clnt->status = BeginDisconnect;
 981}
 982EXPORT_SYMBOL(p9_client_begin_disconnect);
 983
 984struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 985				const char *uname, kuid_t n_uname,
 986				const char *aname)
 987{
 988	int err;
 989	struct p9_req_t *req;
 990	struct p9_fid *fid;
 991	struct p9_qid qid;
 992
 993	p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
 994		 afid ? afid->fid : -1, uname, aname);
 995	fid = p9_fid_create(clnt);
 996	if (!fid) {
 997		err = -ENOMEM;
 998		goto error;
 999	}
1000	fid->uid = n_uname;
1001
1002	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1003			    afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1004	if (IS_ERR(req)) {
1005		err = PTR_ERR(req);
1006		goto error;
1007	}
1008
1009	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
1010	if (err) {
1011		trace_9p_protocol_dump(clnt, &req->rc);
1012		p9_req_put(clnt, req);
1013		goto error;
1014	}
1015
1016	p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1017		 qid.type, qid.path, qid.version);
1018
1019	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1020
1021	p9_req_put(clnt, req);
1022	return fid;
1023
1024error:
1025	if (fid)
1026		p9_fid_destroy(fid);
1027	return ERR_PTR(err);
1028}
1029EXPORT_SYMBOL(p9_client_attach);
1030
1031struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1032			      const unsigned char * const *wnames, int clone)
1033{
1034	int err;
1035	struct p9_client *clnt;
1036	struct p9_fid *fid;
1037	struct p9_qid *wqids;
1038	struct p9_req_t *req;
1039	u16 nwqids, count;
1040
1041	wqids = NULL;
1042	clnt = oldfid->clnt;
1043	if (clone) {
1044		fid = p9_fid_create(clnt);
1045		if (!fid) {
1046			err = -ENOMEM;
1047			goto error;
1048		}
1049
1050		fid->uid = oldfid->uid;
1051	} else {
1052		fid = oldfid;
1053	}
1054
1055	p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1056		 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1057	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1058			    nwname, wnames);
1059	if (IS_ERR(req)) {
1060		err = PTR_ERR(req);
1061		goto error;
1062	}
1063
1064	err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1065	if (err) {
1066		trace_9p_protocol_dump(clnt, &req->rc);
1067		p9_req_put(clnt, req);
1068		goto clunk_fid;
1069	}
1070	p9_req_put(clnt, req);
1071
1072	p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1073
1074	if (nwqids != nwname) {
1075		err = -ENOENT;
1076		goto clunk_fid;
1077	}
1078
1079	for (count = 0; count < nwqids; count++)
1080		p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1081			 count, wqids[count].type,
1082			 wqids[count].path,
1083			 wqids[count].version);
1084
1085	if (nwname)
1086		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1087	else
1088		memmove(&fid->qid, &oldfid->qid, sizeof(struct p9_qid));
1089
1090	kfree(wqids);
1091	return fid;
1092
1093clunk_fid:
1094	kfree(wqids);
1095	p9_fid_put(fid);
1096	fid = NULL;
1097
1098error:
1099	if (fid && fid != oldfid)
1100		p9_fid_destroy(fid);
1101
1102	return ERR_PTR(err);
1103}
1104EXPORT_SYMBOL(p9_client_walk);
1105
1106int p9_client_open(struct p9_fid *fid, int mode)
1107{
1108	int err;
1109	struct p9_client *clnt;
1110	struct p9_req_t *req;
1111	struct p9_qid qid;
1112	int iounit;
1113
1114	clnt = fid->clnt;
1115	p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1116		 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1117
1118	if (fid->mode != -1)
1119		return -EINVAL;
1120
1121	if (p9_is_proto_dotl(clnt))
1122		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode & P9L_MODE_MASK);
1123	else
1124		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode & P9L_MODE_MASK);
1125	if (IS_ERR(req)) {
1126		err = PTR_ERR(req);
1127		goto error;
1128	}
1129
1130	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1131	if (err) {
1132		trace_9p_protocol_dump(clnt, &req->rc);
1133		goto free_and_error;
1134	}
1135
1136	p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1137		 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1138		 qid.path, qid.version, iounit);
1139
1140	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1141	fid->mode = mode;
1142	fid->iounit = iounit;
1143
1144free_and_error:
1145	p9_req_put(clnt, req);
1146error:
1147	return err;
1148}
1149EXPORT_SYMBOL(p9_client_open);
1150
1151int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags,
1152			  u32 mode, kgid_t gid, struct p9_qid *qid)
1153{
1154	int err;
1155	struct p9_client *clnt;
1156	struct p9_req_t *req;
1157	int iounit;
1158
1159	p9_debug(P9_DEBUG_9P,
1160		 ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1161		 ofid->fid, name, flags, mode,
1162		 from_kgid(&init_user_ns, gid));
1163	clnt = ofid->clnt;
1164
1165	if (ofid->mode != -1)
1166		return -EINVAL;
1167
1168	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1169			    mode & P9L_MODE_MASK, gid);
1170	if (IS_ERR(req)) {
1171		err = PTR_ERR(req);
1172		goto error;
1173	}
1174
1175	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
1176	if (err) {
1177		trace_9p_protocol_dump(clnt, &req->rc);
1178		goto free_and_error;
1179	}
1180
1181	p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1182		 qid->type, qid->path, qid->version, iounit);
1183
1184	memmove(&ofid->qid, qid, sizeof(struct p9_qid));
1185	ofid->mode = flags;
1186	ofid->iounit = iounit;
1187
1188free_and_error:
1189	p9_req_put(clnt, req);
1190error:
1191	return err;
1192}
1193EXPORT_SYMBOL(p9_client_create_dotl);
1194
1195int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1196		     char *extension)
1197{
1198	int err;
1199	struct p9_client *clnt;
1200	struct p9_req_t *req;
1201	struct p9_qid qid;
1202	int iounit;
1203
1204	p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1205		 fid->fid, name, perm, mode);
1206	clnt = fid->clnt;
1207
1208	if (fid->mode != -1)
1209		return -EINVAL;
1210
1211	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1212			    mode & P9L_MODE_MASK, extension);
1213	if (IS_ERR(req)) {
1214		err = PTR_ERR(req);
1215		goto error;
1216	}
1217
1218	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1219	if (err) {
1220		trace_9p_protocol_dump(clnt, &req->rc);
1221		goto free_and_error;
1222	}
1223
1224	p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1225		 qid.type, qid.path, qid.version, iounit);
1226
1227	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1228	fid->mode = mode;
1229	fid->iounit = iounit;
1230
1231free_and_error:
1232	p9_req_put(clnt, req);
1233error:
1234	return err;
1235}
1236EXPORT_SYMBOL(p9_client_fcreate);
1237
1238int p9_client_symlink(struct p9_fid *dfid, const char *name,
1239		      const char *symtgt, kgid_t gid, struct p9_qid *qid)
1240{
1241	int err;
1242	struct p9_client *clnt;
1243	struct p9_req_t *req;
1244
1245	p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1246		 dfid->fid, name, symtgt);
1247	clnt = dfid->clnt;
1248
1249	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1250			    gid);
1251	if (IS_ERR(req)) {
1252		err = PTR_ERR(req);
1253		goto error;
1254	}
1255
1256	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
1257	if (err) {
1258		trace_9p_protocol_dump(clnt, &req->rc);
1259		goto free_and_error;
1260	}
1261
1262	p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1263		 qid->type, qid->path, qid->version);
1264
1265free_and_error:
1266	p9_req_put(clnt, req);
1267error:
1268	return err;
1269}
1270EXPORT_SYMBOL(p9_client_symlink);
1271
1272int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1273{
1274	struct p9_client *clnt;
1275	struct p9_req_t *req;
1276
1277	p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1278		 dfid->fid, oldfid->fid, newname);
1279	clnt = dfid->clnt;
1280	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1281			    newname);
1282	if (IS_ERR(req))
1283		return PTR_ERR(req);
1284
1285	p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1286	p9_req_put(clnt, req);
1287	return 0;
1288}
1289EXPORT_SYMBOL(p9_client_link);
1290
1291int p9_client_fsync(struct p9_fid *fid, int datasync)
1292{
1293	int err = 0;
1294	struct p9_client *clnt;
1295	struct p9_req_t *req;
1296
1297	p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1298		 fid->fid, datasync);
1299	clnt = fid->clnt;
1300
1301	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1302	if (IS_ERR(req)) {
1303		err = PTR_ERR(req);
1304		goto error;
1305	}
1306
1307	p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1308
1309	p9_req_put(clnt, req);
1310
1311error:
1312	return err;
1313}
1314EXPORT_SYMBOL(p9_client_fsync);
1315
1316int p9_client_clunk(struct p9_fid *fid)
1317{
1318	int err = 0;
1319	struct p9_client *clnt;
1320	struct p9_req_t *req;
1321	int retries = 0;
1322
1323again:
1324	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n",
1325		 fid->fid, retries);
1326	clnt = fid->clnt;
1327
1328	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1329	if (IS_ERR(req)) {
1330		err = PTR_ERR(req);
1331		goto error;
1332	}
1333
1334	p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1335
1336	p9_req_put(clnt, req);
1337error:
1338	/* Fid is not valid even after a failed clunk
1339	 * If interrupted, retry once then give up and
1340	 * leak fid until umount.
1341	 */
1342	if (err == -ERESTARTSYS) {
1343		if (retries++ == 0)
1344			goto again;
1345	} else {
1346		p9_fid_destroy(fid);
1347	}
1348	return err;
1349}
1350EXPORT_SYMBOL(p9_client_clunk);
1351
1352int p9_client_remove(struct p9_fid *fid)
1353{
1354	int err = 0;
1355	struct p9_client *clnt;
1356	struct p9_req_t *req;
1357
1358	p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1359	clnt = fid->clnt;
1360
1361	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1362	if (IS_ERR(req)) {
1363		err = PTR_ERR(req);
1364		goto error;
1365	}
1366
1367	p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1368
1369	p9_req_put(clnt, req);
1370error:
1371	if (err == -ERESTARTSYS)
1372		p9_fid_put(fid);
1373	else
1374		p9_fid_destroy(fid);
1375	return err;
1376}
1377EXPORT_SYMBOL(p9_client_remove);
1378
1379int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1380{
1381	int err = 0;
1382	struct p9_req_t *req;
1383	struct p9_client *clnt;
1384
1385	p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1386		 dfid->fid, name, flags);
1387
1388	clnt = dfid->clnt;
1389	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1390	if (IS_ERR(req)) {
1391		err = PTR_ERR(req);
1392		goto error;
1393	}
1394	p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1395
1396	p9_req_put(clnt, req);
1397error:
1398	return err;
1399}
1400EXPORT_SYMBOL(p9_client_unlinkat);
1401
1402int
1403p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1404{
1405	int total = 0;
1406	*err = 0;
1407
1408	while (iov_iter_count(to)) {
1409		int count;
1410
1411		count = p9_client_read_once(fid, offset, to, err);
1412		if (!count || *err)
1413			break;
1414		offset += count;
1415		total += count;
1416	}
1417	return total;
1418}
1419EXPORT_SYMBOL(p9_client_read);
1420
1421int
1422p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
1423		    int *err)
1424{
1425	struct p9_client *clnt = fid->clnt;
1426	struct p9_req_t *req;
1427	int count = iov_iter_count(to);
1428	u32 rsize, received;
1429	bool non_zc = false;
1430	char *dataptr;
1431
1432	*err = 0;
1433	p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %zu\n",
1434		 fid->fid, offset, iov_iter_count(to));
1435
1436	rsize = fid->iounit;
1437	if (!rsize || rsize > clnt->msize - P9_IOHDRSZ)
1438		rsize = clnt->msize - P9_IOHDRSZ;
1439
1440	if (count < rsize)
1441		rsize = count;
1442
1443	/* Don't bother zerocopy for small IO (< 1024) */
1444	if (clnt->trans_mod->zc_request && rsize > 1024) {
1445		/* response header len is 11
1446		 * PDU Header(7) + IO Size (4)
1447		 */
1448		req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1449				       0, 11, "dqd", fid->fid,
1450				       offset, rsize);
1451	} else {
1452		non_zc = true;
1453		req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1454				    rsize);
1455	}
1456	if (IS_ERR(req)) {
1457		*err = PTR_ERR(req);
1458		if (!non_zc)
1459			iov_iter_revert(to, count - iov_iter_count(to));
1460		return 0;
1461	}
1462
1463	*err = p9pdu_readf(&req->rc, clnt->proto_version,
1464			   "D", &received, &dataptr);
1465	if (*err) {
1466		if (!non_zc)
1467			iov_iter_revert(to, count - iov_iter_count(to));
1468		trace_9p_protocol_dump(clnt, &req->rc);
1469		p9_req_put(clnt, req);
1470		return 0;
1471	}
1472	if (rsize < received) {
1473		pr_err("bogus RREAD count (%u > %u)\n", received, rsize);
1474		*err = -EIO;
1475		p9_req_put(clnt, req);
1476		return 0;
1477	}
1478
1479	p9_debug(P9_DEBUG_9P, "<<< RREAD count %u\n", received);
1480
1481	if (non_zc) {
1482		int n = copy_to_iter(dataptr, received, to);
1483
1484		if (n != received) {
1485			*err = -EFAULT;
1486			p9_req_put(clnt, req);
1487			return n;
1488		}
1489	} else {
1490		iov_iter_revert(to, count - received - iov_iter_count(to));
1491	}
1492	p9_req_put(clnt, req);
1493	return received;
1494}
1495EXPORT_SYMBOL(p9_client_read_once);
1496
1497int
1498p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1499{
1500	struct p9_client *clnt = fid->clnt;
1501	struct p9_req_t *req;
1502	int total = 0;
1503	*err = 0;
1504
1505	while (iov_iter_count(from)) {
1506		size_t count = iov_iter_count(from);
1507		u32 rsize = fid->iounit;
1508		u32 written;
1509
1510		if (!rsize || rsize > clnt->msize - P9_IOHDRSZ)
1511			rsize = clnt->msize - P9_IOHDRSZ;
1512
1513		if (count < rsize)
1514			rsize = count;
1515
1516		p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %u (/%zu)\n",
1517			 fid->fid, offset, rsize, count);
1518
1519		/* Don't bother zerocopy for small IO (< 1024) */
1520		if (clnt->trans_mod->zc_request && rsize > 1024) {
1521			req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1522					       rsize, P9_ZC_HDR_SZ, "dqd",
1523					       fid->fid, offset, rsize);
1524		} else {
1525			req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1526					    offset, rsize, from);
1527		}
1528		if (IS_ERR(req)) {
1529			iov_iter_revert(from, count - iov_iter_count(from));
1530			*err = PTR_ERR(req);
1531			break;
1532		}
1533
1534		*err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &written);
1535		if (*err) {
1536			iov_iter_revert(from, count - iov_iter_count(from));
1537			trace_9p_protocol_dump(clnt, &req->rc);
1538			p9_req_put(clnt, req);
1539			break;
1540		}
1541		if (rsize < written) {
1542			pr_err("bogus RWRITE count (%u > %u)\n", written, rsize);
1543			*err = -EIO;
1544			iov_iter_revert(from, count - iov_iter_count(from));
1545			p9_req_put(clnt, req);
1546			break;
1547		}
1548
1549		p9_debug(P9_DEBUG_9P, "<<< RWRITE count %u\n", written);
1550
1551		p9_req_put(clnt, req);
1552		iov_iter_revert(from, count - written - iov_iter_count(from));
1553		total += written;
1554		offset += written;
1555	}
1556	return total;
1557}
1558EXPORT_SYMBOL(p9_client_write);
1559
1560void
1561p9_client_write_subreq(struct netfs_io_subrequest *subreq)
1562{
1563	struct netfs_io_request *wreq = subreq->rreq;
1564	struct p9_fid *fid = wreq->netfs_priv;
1565	struct p9_client *clnt = fid->clnt;
1566	struct p9_req_t *req;
1567	unsigned long long start = subreq->start + subreq->transferred;
1568	int written, len = subreq->len - subreq->transferred;
1569	int err;
1570
1571	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu len %d\n",
1572		 fid->fid, start, len);
1573
1574	/* Don't bother zerocopy for small IO (< 1024) */
1575	if (clnt->trans_mod->zc_request && len > 1024) {
1576		req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, &subreq->io_iter,
1577				       0, wreq->len, P9_ZC_HDR_SZ, "dqd",
1578				       fid->fid, start, len);
1579	} else {
1580		req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1581				    start, len, &subreq->io_iter);
1582	}
1583	if (IS_ERR(req)) {
1584		netfs_write_subrequest_terminated(subreq, PTR_ERR(req));
1585		return;
1586	}
1587
1588	err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &written);
1589	if (err) {
1590		trace_9p_protocol_dump(clnt, &req->rc);
1591		p9_req_put(clnt, req);
1592		netfs_write_subrequest_terminated(subreq, err);
1593		return;
1594	}
1595
1596	if (written > len) {
1597		pr_err("bogus RWRITE count (%d > %u)\n", written, len);
1598		written = -EIO;
1599	}
1600
1601	p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", len);
1602
1603	p9_req_put(clnt, req);
1604	netfs_write_subrequest_terminated(subreq, written);
1605}
1606EXPORT_SYMBOL(p9_client_write_subreq);
1607
1608struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1609{
1610	int err;
1611	struct p9_client *clnt;
1612	struct p9_wstat *ret;
1613	struct p9_req_t *req;
1614	u16 ignored;
1615
1616	p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1617
1618	ret = kmalloc(sizeof(*ret), GFP_KERNEL);
1619	if (!ret)
1620		return ERR_PTR(-ENOMEM);
1621
1622	clnt = fid->clnt;
1623
1624	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1625	if (IS_ERR(req)) {
1626		err = PTR_ERR(req);
1627		goto error;
1628	}
1629
1630	err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
1631	if (err) {
1632		trace_9p_protocol_dump(clnt, &req->rc);
1633		p9_req_put(clnt, req);
1634		goto error;
1635	}
1636
1637	p9_debug(P9_DEBUG_9P,
1638		 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1639		 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1640		 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1641		 "<<<    uid=%d gid=%d n_muid=%d\n",
1642		 ret->size, ret->type, ret->dev, ret->qid.type, ret->qid.path,
1643		 ret->qid.version, ret->mode,
1644		 ret->atime, ret->mtime, ret->length,
1645		 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1646		 from_kuid(&init_user_ns, ret->n_uid),
1647		 from_kgid(&init_user_ns, ret->n_gid),
1648		 from_kuid(&init_user_ns, ret->n_muid));
1649
1650	p9_req_put(clnt, req);
1651	return ret;
1652
1653error:
1654	kfree(ret);
1655	return ERR_PTR(err);
1656}
1657EXPORT_SYMBOL(p9_client_stat);
1658
1659struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1660					    u64 request_mask)
1661{
1662	int err;
1663	struct p9_client *clnt;
1664	struct p9_stat_dotl *ret;
1665	struct p9_req_t *req;
1666
1667	p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1668		 fid->fid, request_mask);
1669
1670	ret = kmalloc(sizeof(*ret), GFP_KERNEL);
1671	if (!ret)
1672		return ERR_PTR(-ENOMEM);
1673
1674	clnt = fid->clnt;
1675
1676	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1677	if (IS_ERR(req)) {
1678		err = PTR_ERR(req);
1679		goto error;
1680	}
1681
1682	err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
1683	if (err) {
1684		trace_9p_protocol_dump(clnt, &req->rc);
1685		p9_req_put(clnt, req);
1686		goto error;
1687	}
1688
1689	p9_debug(P9_DEBUG_9P, "<<< RGETATTR st_result_mask=%lld\n"
1690		 "<<< qid=%x.%llx.%x\n"
1691		 "<<< st_mode=%8.8x st_nlink=%llu\n"
1692		 "<<< st_uid=%d st_gid=%d\n"
1693		 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1694		 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1695		 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1696		 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1697		 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1698		 "<<< st_gen=%lld st_data_version=%lld\n",
1699		 ret->st_result_mask,
1700		 ret->qid.type, ret->qid.path, ret->qid.version,
1701		 ret->st_mode, ret->st_nlink,
1702		 from_kuid(&init_user_ns, ret->st_uid),
1703		 from_kgid(&init_user_ns, ret->st_gid),
1704		 ret->st_rdev, ret->st_size, ret->st_blksize, ret->st_blocks,
1705		 ret->st_atime_sec, ret->st_atime_nsec,
1706		 ret->st_mtime_sec, ret->st_mtime_nsec,
1707		 ret->st_ctime_sec, ret->st_ctime_nsec,
1708		 ret->st_btime_sec, ret->st_btime_nsec,
1709		 ret->st_gen, ret->st_data_version);
1710
1711	p9_req_put(clnt, req);
1712	return ret;
1713
1714error:
1715	kfree(ret);
1716	return ERR_PTR(err);
1717}
1718EXPORT_SYMBOL(p9_client_getattr_dotl);
1719
1720static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1721{
1722	int ret;
1723
1724	/* NOTE: size shouldn't include its own length */
1725	/* size[2] type[2] dev[4] qid[13] */
1726	/* mode[4] atime[4] mtime[4] length[8]*/
1727	/* name[s] uid[s] gid[s] muid[s] */
1728	ret = 2 + 4 + 13 + 4 + 4 + 4 + 8 + 2 + 2 + 2 + 2;
1729
1730	if (wst->name)
1731		ret += strlen(wst->name);
1732	if (wst->uid)
1733		ret += strlen(wst->uid);
1734	if (wst->gid)
1735		ret += strlen(wst->gid);
1736	if (wst->muid)
1737		ret += strlen(wst->muid);
1738
1739	if (proto_version == p9_proto_2000u ||
1740	    proto_version == p9_proto_2000L) {
1741		/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1742		ret += 2 + 4 + 4 + 4;
1743		if (wst->extension)
1744			ret += strlen(wst->extension);
1745	}
1746
1747	return ret;
1748}
1749
1750int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1751{
1752	int err = 0;
1753	struct p9_req_t *req;
1754	struct p9_client *clnt;
1755
1756	clnt = fid->clnt;
1757	wst->size = p9_client_statsize(wst, clnt->proto_version);
1758	p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n",
1759		 fid->fid);
1760	p9_debug(P9_DEBUG_9P,
1761		 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1762		 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1763		 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1764		 "     uid=%d gid=%d n_muid=%d\n",
1765		 wst->size, wst->type, wst->dev, wst->qid.type,
1766		 wst->qid.path, wst->qid.version,
1767		 wst->mode, wst->atime, wst->mtime, wst->length,
1768		 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1769		 from_kuid(&init_user_ns, wst->n_uid),
1770		 from_kgid(&init_user_ns, wst->n_gid),
1771		 from_kuid(&init_user_ns, wst->n_muid));
1772
1773	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS",
1774			    fid->fid, wst->size + 2, wst);
1775	if (IS_ERR(req)) {
1776		err = PTR_ERR(req);
1777		goto error;
1778	}
1779
1780	p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1781
1782	p9_req_put(clnt, req);
1783error:
1784	return err;
1785}
1786EXPORT_SYMBOL(p9_client_wstat);
1787
1788int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1789{
1790	int err = 0;
1791	struct p9_req_t *req;
1792	struct p9_client *clnt;
1793
1794	clnt = fid->clnt;
1795	p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1796	p9_debug(P9_DEBUG_9P, "    valid=%x mode=%x uid=%d gid=%d size=%lld\n",
1797		 p9attr->valid, p9attr->mode,
1798		 from_kuid(&init_user_ns, p9attr->uid),
1799		 from_kgid(&init_user_ns, p9attr->gid),
1800		 p9attr->size);
1801	p9_debug(P9_DEBUG_9P, "    atime_sec=%lld atime_nsec=%lld\n",
1802		 p9attr->atime_sec, p9attr->atime_nsec);
1803	p9_debug(P9_DEBUG_9P, "    mtime_sec=%lld mtime_nsec=%lld\n",
1804		 p9attr->mtime_sec, p9attr->mtime_nsec);
1805
1806	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1807
1808	if (IS_ERR(req)) {
1809		err = PTR_ERR(req);
1810		goto error;
1811	}
1812	p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1813	p9_req_put(clnt, req);
1814error:
1815	return err;
1816}
1817EXPORT_SYMBOL(p9_client_setattr);
1818
1819int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1820{
1821	int err;
1822	struct p9_req_t *req;
1823	struct p9_client *clnt;
1824
1825	clnt = fid->clnt;
1826
1827	p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1828
1829	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1830	if (IS_ERR(req)) {
1831		err = PTR_ERR(req);
1832		goto error;
1833	}
1834
1835	err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1836			  &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1837			  &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1838	if (err) {
1839		trace_9p_protocol_dump(clnt, &req->rc);
1840		p9_req_put(clnt, req);
1841		goto error;
1842	}
1843
1844	p9_debug(P9_DEBUG_9P,
1845		 "<<< RSTATFS fid %d type 0x%x bsize %u blocks %llu bfree %llu bavail %llu files %llu ffree %llu fsid %llu namelen %u\n",
1846		 fid->fid, sb->type, sb->bsize, sb->blocks, sb->bfree,
1847		 sb->bavail, sb->files, sb->ffree, sb->fsid, sb->namelen);
1848
1849	p9_req_put(clnt, req);
1850error:
1851	return err;
1852}
1853EXPORT_SYMBOL(p9_client_statfs);
1854
1855int p9_client_rename(struct p9_fid *fid,
1856		     struct p9_fid *newdirfid, const char *name)
1857{
1858	int err = 0;
1859	struct p9_req_t *req;
1860	struct p9_client *clnt;
1861
1862	clnt = fid->clnt;
1863
1864	p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1865		 fid->fid, newdirfid->fid, name);
1866
1867	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1868			    newdirfid->fid, name);
1869	if (IS_ERR(req)) {
1870		err = PTR_ERR(req);
1871		goto error;
1872	}
1873
1874	p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1875
1876	p9_req_put(clnt, req);
1877error:
1878	return err;
1879}
1880EXPORT_SYMBOL(p9_client_rename);
1881
1882int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1883		       struct p9_fid *newdirfid, const char *new_name)
1884{
1885	int err = 0;
1886	struct p9_req_t *req;
1887	struct p9_client *clnt;
1888
1889	clnt = olddirfid->clnt;
1890
1891	p9_debug(P9_DEBUG_9P,
1892		 ">>> TRENAMEAT olddirfid %d old name %s newdirfid %d new name %s\n",
1893		 olddirfid->fid, old_name, newdirfid->fid, new_name);
1894
1895	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1896			    old_name, newdirfid->fid, new_name);
1897	if (IS_ERR(req)) {
1898		err = PTR_ERR(req);
1899		goto error;
1900	}
1901
1902	p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1903		 newdirfid->fid, new_name);
1904
1905	p9_req_put(clnt, req);
1906error:
1907	return err;
1908}
1909EXPORT_SYMBOL(p9_client_renameat);
1910
1911/* An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1912 */
1913struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1914				   const char *attr_name, u64 *attr_size)
1915{
1916	int err;
1917	struct p9_req_t *req;
1918	struct p9_client *clnt;
1919	struct p9_fid *attr_fid;
1920
1921	clnt = file_fid->clnt;
1922	attr_fid = p9_fid_create(clnt);
1923	if (!attr_fid) {
1924		err = -ENOMEM;
1925		goto error;
1926	}
1927	p9_debug(P9_DEBUG_9P,
1928		 ">>> TXATTRWALK file_fid %d, attr_fid %d name '%s'\n",
1929		 file_fid->fid, attr_fid->fid, attr_name);
1930
1931	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1932			    file_fid->fid, attr_fid->fid, attr_name);
1933	if (IS_ERR(req)) {
1934		err = PTR_ERR(req);
1935		goto error;
1936	}
1937	err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
1938	if (err) {
1939		trace_9p_protocol_dump(clnt, &req->rc);
1940		p9_req_put(clnt, req);
1941		goto clunk_fid;
1942	}
1943	p9_req_put(clnt, req);
1944	p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
1945		 attr_fid->fid, *attr_size);
1946	return attr_fid;
1947clunk_fid:
1948	p9_fid_put(attr_fid);
1949	attr_fid = NULL;
1950error:
1951	if (attr_fid && attr_fid != file_fid)
1952		p9_fid_destroy(attr_fid);
1953
1954	return ERR_PTR(err);
1955}
1956EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
1957
1958int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
1959			  u64 attr_size, int flags)
1960{
1961	int err = 0;
1962	struct p9_req_t *req;
1963	struct p9_client *clnt;
1964
1965	p9_debug(P9_DEBUG_9P,
1966		 ">>> TXATTRCREATE fid %d name  %s size %llu flag %d\n",
1967		 fid->fid, name, attr_size, flags);
1968	clnt = fid->clnt;
1969	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
1970			    fid->fid, name, attr_size, flags);
1971	if (IS_ERR(req)) {
1972		err = PTR_ERR(req);
1973		goto error;
1974	}
1975	p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
1976	p9_req_put(clnt, req);
1977error:
1978	return err;
1979}
1980EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
1981
1982int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
1983{
1984	int err, non_zc = 0;
1985	u32 rsize;
1986	struct p9_client *clnt;
1987	struct p9_req_t *req;
1988	char *dataptr;
1989	struct kvec kv = {.iov_base = data, .iov_len = count};
1990	struct iov_iter to;
1991
1992	iov_iter_kvec(&to, ITER_DEST, &kv, 1, count);
1993
1994	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %u\n",
1995		 fid->fid, offset, count);
1996
1997	clnt = fid->clnt;
1998
1999	rsize = fid->iounit;
2000	if (!rsize || rsize > clnt->msize - P9_READDIRHDRSZ)
2001		rsize = clnt->msize - P9_READDIRHDRSZ;
2002
2003	if (count < rsize)
2004		rsize = count;
2005
2006	/* Don't bother zerocopy for small IO (< 1024) */
2007	if (clnt->trans_mod->zc_request && rsize > 1024) {
2008		/* response header len is 11
2009		 * PDU Header(7) + IO Size (4)
2010		 */
2011		req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2012				       11, "dqd", fid->fid, offset, rsize);
2013	} else {
2014		non_zc = 1;
2015		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2016				    offset, rsize);
2017	}
2018	if (IS_ERR(req)) {
2019		err = PTR_ERR(req);
2020		goto error;
2021	}
2022
2023	err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
2024	if (err) {
2025		trace_9p_protocol_dump(clnt, &req->rc);
2026		goto free_and_error;
2027	}
2028	if (rsize < count) {
2029		pr_err("bogus RREADDIR count (%u > %u)\n", count, rsize);
2030		err = -EIO;
2031		goto free_and_error;
2032	}
2033
2034	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %u\n", count);
2035
2036	if (non_zc)
2037		memmove(data, dataptr, count);
2038
2039	p9_req_put(clnt, req);
2040	return count;
2041
2042free_and_error:
2043	p9_req_put(clnt, req);
2044error:
2045	return err;
2046}
2047EXPORT_SYMBOL(p9_client_readdir);
2048
2049int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2050			 dev_t rdev, kgid_t gid, struct p9_qid *qid)
2051{
2052	int err;
2053	struct p9_client *clnt;
2054	struct p9_req_t *req;
2055
2056	clnt = fid->clnt;
2057	p9_debug(P9_DEBUG_9P,
2058		 ">>> TMKNOD fid %d name %s mode %d major %d minor %d\n",
2059		 fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2060	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2061			    MAJOR(rdev), MINOR(rdev), gid);
2062	if (IS_ERR(req))
2063		return PTR_ERR(req);
2064
2065	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2066	if (err) {
2067		trace_9p_protocol_dump(clnt, &req->rc);
2068		goto error;
2069	}
2070	p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n",
2071		 qid->type, qid->path, qid->version);
2072
2073error:
2074	p9_req_put(clnt, req);
2075	return err;
2076}
2077EXPORT_SYMBOL(p9_client_mknod_dotl);
2078
2079int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2080			 kgid_t gid, struct p9_qid *qid)
2081{
2082	int err;
2083	struct p9_client *clnt;
2084	struct p9_req_t *req;
2085
2086	clnt = fid->clnt;
2087	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2088		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2089	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg",
2090			    fid->fid, name, mode, gid);
2091	if (IS_ERR(req))
2092		return PTR_ERR(req);
2093
2094	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2095	if (err) {
2096		trace_9p_protocol_dump(clnt, &req->rc);
2097		goto error;
2098	}
2099	p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2100		 qid->path, qid->version);
2101
2102error:
2103	p9_req_put(clnt, req);
2104	return err;
2105}
2106EXPORT_SYMBOL(p9_client_mkdir_dotl);
2107
2108int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2109{
2110	int err;
2111	struct p9_client *clnt;
2112	struct p9_req_t *req;
2113
2114	clnt = fid->clnt;
2115	p9_debug(P9_DEBUG_9P,
2116		 ">>> TLOCK fid %d type %i flags %d start %lld length %lld proc_id %d client_id %s\n",
2117		 fid->fid, flock->type, flock->flags, flock->start,
2118		 flock->length, flock->proc_id, flock->client_id);
2119
2120	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2121			    flock->flags, flock->start, flock->length,
2122			    flock->proc_id, flock->client_id);
2123
2124	if (IS_ERR(req))
2125		return PTR_ERR(req);
2126
2127	err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
2128	if (err) {
2129		trace_9p_protocol_dump(clnt, &req->rc);
2130		goto error;
2131	}
2132	p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2133error:
2134	p9_req_put(clnt, req);
2135	return err;
2136}
2137EXPORT_SYMBOL(p9_client_lock_dotl);
2138
2139int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2140{
2141	int err;
2142	struct p9_client *clnt;
2143	struct p9_req_t *req;
2144
2145	clnt = fid->clnt;
2146	p9_debug(P9_DEBUG_9P,
2147		 ">>> TGETLOCK fid %d, type %i start %lld length %lld proc_id %d client_id %s\n",
2148		 fid->fid, glock->type, glock->start, glock->length,
2149		 glock->proc_id, glock->client_id);
2150
2151	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,
2152			    glock->type, glock->start, glock->length,
2153			    glock->proc_id, glock->client_id);
2154
2155	if (IS_ERR(req))
2156		return PTR_ERR(req);
2157
2158	err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type,
2159			  &glock->start, &glock->length, &glock->proc_id,
2160			  &glock->client_id);
2161	if (err) {
2162		trace_9p_protocol_dump(clnt, &req->rc);
2163		goto error;
2164	}
2165	p9_debug(P9_DEBUG_9P,
2166		 "<<< RGETLOCK type %i start %lld length %lld proc_id %d client_id %s\n",
2167		 glock->type, glock->start, glock->length,
2168		 glock->proc_id, glock->client_id);
2169error:
2170	p9_req_put(clnt, req);
2171	return err;
2172}
2173EXPORT_SYMBOL(p9_client_getlock_dotl);
2174
2175int p9_client_readlink(struct p9_fid *fid, char **target)
2176{
2177	int err;
2178	struct p9_client *clnt;
2179	struct p9_req_t *req;
2180
2181	clnt = fid->clnt;
2182	p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2183
2184	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2185	if (IS_ERR(req))
2186		return PTR_ERR(req);
2187
2188	err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
2189	if (err) {
2190		trace_9p_protocol_dump(clnt, &req->rc);
2191		goto error;
2192	}
2193	p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2194error:
2195	p9_req_put(clnt, req);
2196	return err;
2197}
2198EXPORT_SYMBOL(p9_client_readlink);
2199
2200int __init p9_client_init(void)
2201{
2202	p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU);
2203	return p9_req_cache ? 0 : -ENOMEM;
2204}
2205
2206void __exit p9_client_exit(void)
2207{
2208	kmem_cache_destroy(p9_req_cache);
2209}