xref: /kernel/linux/linux-5.10/net/9p/client.c (revision 8c2ecf20)
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 = NULL;
524
525		err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
526				  &ename, &ecode);
527		if (err) {
528			kfree(ename);
529			goto out_err;
530		}
531
532		if (p9_is_proto_dotu(c) && ecode < 512)
533			err = -ecode;
534
535		if (!err) {
536			err = p9_errstr2errno(ename, strlen(ename));
537
538			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
539				 -ecode, ename);
540		}
541		kfree(ename);
542	} else {
543		err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
544		if (err)
545			goto out_err;
546		err = -ecode;
547
548		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
549	}
550
551	return err;
552
553out_err:
554	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
555
556	return err;
557}
558
559/**
560 * p9_check_zc_errors - check 9p packet for error return and process it
561 * @c: current client instance
562 * @req: request to parse and check for error conditions
563 * @in_hdrlen: Size of response protocol buffer.
564 *
565 * returns error code if one is discovered, otherwise returns 0
566 *
567 * this will have to be more complicated if we have multiple
568 * error packet types
569 */
570
571static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
572			      struct iov_iter *uidata, int in_hdrlen)
573{
574	int err;
575	int ecode;
576	int8_t type;
577	char *ename = NULL;
578
579	err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
580	/*
581	 * dump the response from server
582	 * This should be after parse_header which poplulate pdu_fcall.
583	 */
584	trace_9p_protocol_dump(c, &req->rc);
585	if (err) {
586		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
587		return err;
588	}
589
590	if (type != P9_RERROR && type != P9_RLERROR)
591		return 0;
592
593	if (!p9_is_proto_dotl(c)) {
594		/* Error is reported in string format */
595		int len;
596		/* 7 = header size for RERROR; */
597		int inline_len = in_hdrlen - 7;
598
599		len = req->rc.size - req->rc.offset;
600		if (len > (P9_ZC_HDR_SZ - 7)) {
601			err = -EFAULT;
602			goto out_err;
603		}
604
605		ename = &req->rc.sdata[req->rc.offset];
606		if (len > inline_len) {
607			/* We have error in external buffer */
608			if (!copy_from_iter_full(ename + inline_len,
609					     len - inline_len, uidata)) {
610				err = -EFAULT;
611				goto out_err;
612			}
613		}
614		ename = NULL;
615		err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
616				  &ename, &ecode);
617		if (err)
618			goto out_err;
619
620		if (p9_is_proto_dotu(c) && ecode < 512)
621			err = -ecode;
622
623		if (!err) {
624			err = p9_errstr2errno(ename, strlen(ename));
625
626			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
627				 -ecode, ename);
628		}
629		kfree(ename);
630	} else {
631		err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
632		err = -ecode;
633
634		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
635	}
636	return err;
637
638out_err:
639	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
640	return err;
641}
642
643static struct p9_req_t *
644p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
645
646/**
647 * p9_client_flush - flush (cancel) a request
648 * @c: client state
649 * @oldreq: request to cancel
650 *
651 * This sents a flush for a particular request and links
652 * the flush request to the original request.  The current
653 * code only supports a single flush request although the protocol
654 * allows for multiple flush requests to be sent for a single request.
655 *
656 */
657
658static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
659{
660	struct p9_req_t *req;
661	int16_t oldtag;
662	int err;
663
664	err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
665	if (err)
666		return err;
667
668	p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
669
670	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
671	if (IS_ERR(req))
672		return PTR_ERR(req);
673
674	/*
675	 * if we haven't received a response for oldreq,
676	 * remove it from the list
677	 */
678	if (oldreq->status == REQ_STATUS_SENT) {
679		if (c->trans_mod->cancelled)
680			c->trans_mod->cancelled(c, oldreq);
681	}
682
683	p9_tag_remove(c, req);
684	return 0;
685}
686
687static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
688					      int8_t type, int req_size,
689					      const char *fmt, va_list ap)
690{
691	int err;
692	struct p9_req_t *req;
693
694	p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
695
696	/* we allow for any status other than disconnected */
697	if (c->status == Disconnected)
698		return ERR_PTR(-EIO);
699
700	/* if status is begin_disconnected we allow only clunk request */
701	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
702		return ERR_PTR(-EIO);
703
704	req = p9_tag_alloc(c, type, req_size);
705	if (IS_ERR(req))
706		return req;
707
708	/* marshall the data */
709	p9pdu_prepare(&req->tc, req->tc.tag, type);
710	err = p9pdu_vwritef(&req->tc, c->proto_version, fmt, ap);
711	if (err)
712		goto reterr;
713	p9pdu_finalize(c, &req->tc);
714	trace_9p_client_req(c, type, req->tc.tag);
715	return req;
716reterr:
717	p9_tag_remove(c, req);
718	/* We have to put also the 2nd reference as it won't be used */
719	p9_req_put(req);
720	return ERR_PTR(err);
721}
722
723/**
724 * p9_client_rpc - issue a request and wait for a response
725 * @c: client session
726 * @type: type of request
727 * @fmt: protocol format string (see protocol.c)
728 *
729 * Returns request structure (which client must free using p9_tag_remove)
730 */
731
732static struct p9_req_t *
733p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
734{
735	va_list ap;
736	int sigpending, err;
737	unsigned long flags;
738	struct p9_req_t *req;
739
740	va_start(ap, fmt);
741	req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
742	va_end(ap);
743	if (IS_ERR(req))
744		return req;
745
746	if (signal_pending(current)) {
747		sigpending = 1;
748		clear_thread_flag(TIF_SIGPENDING);
749	} else
750		sigpending = 0;
751
752	err = c->trans_mod->request(c, req);
753	if (err < 0) {
754		/* write won't happen */
755		p9_req_put(req);
756		if (err != -ERESTARTSYS && err != -EFAULT)
757			c->status = Disconnected;
758		goto recalc_sigpending;
759	}
760again:
761	/* Wait for the response */
762	err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
763
764	/*
765	 * Make sure our req is coherent with regard to updates in other
766	 * threads - echoes to wmb() in the callback
767	 */
768	smp_rmb();
769
770	if ((err == -ERESTARTSYS) && (c->status == Connected)
771				  && (type == P9_TFLUSH)) {
772		sigpending = 1;
773		clear_thread_flag(TIF_SIGPENDING);
774		goto again;
775	}
776
777	if (req->status == REQ_STATUS_ERROR) {
778		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
779		err = req->t_err;
780	}
781	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
782		p9_debug(P9_DEBUG_MUX, "flushing\n");
783		sigpending = 1;
784		clear_thread_flag(TIF_SIGPENDING);
785
786		if (c->trans_mod->cancel(c, req))
787			p9_client_flush(c, req);
788
789		/* if we received the response anyway, don't signal error */
790		if (req->status == REQ_STATUS_RCVD)
791			err = 0;
792	}
793recalc_sigpending:
794	if (sigpending) {
795		spin_lock_irqsave(&current->sighand->siglock, flags);
796		recalc_sigpending();
797		spin_unlock_irqrestore(&current->sighand->siglock, flags);
798	}
799	if (err < 0)
800		goto reterr;
801
802	err = p9_check_errors(c, req);
803	trace_9p_client_res(c, type, req->rc.tag, err);
804	if (!err)
805		return req;
806reterr:
807	p9_tag_remove(c, req);
808	return ERR_PTR(safe_errno(err));
809}
810
811/**
812 * p9_client_zc_rpc - issue a request and wait for a response
813 * @c: client session
814 * @type: type of request
815 * @uidata: destination for zero copy read
816 * @uodata: source for zero copy write
817 * @inlen: read buffer size
818 * @olen: write buffer size
819 * @in_hdrlen: reader header size, This is the size of response protocol data
820 * @fmt: protocol format string (see protocol.c)
821 *
822 * Returns request structure (which client must free using p9_tag_remove)
823 */
824static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
825					 struct iov_iter *uidata,
826					 struct iov_iter *uodata,
827					 int inlen, int olen, int in_hdrlen,
828					 const char *fmt, ...)
829{
830	va_list ap;
831	int sigpending, err;
832	unsigned long flags;
833	struct p9_req_t *req;
834
835	va_start(ap, fmt);
836	/*
837	 * We allocate a inline protocol data of only 4k bytes.
838	 * The actual content is passed in zero-copy fashion.
839	 */
840	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
841	va_end(ap);
842	if (IS_ERR(req))
843		return req;
844
845	if (signal_pending(current)) {
846		sigpending = 1;
847		clear_thread_flag(TIF_SIGPENDING);
848	} else
849		sigpending = 0;
850
851	err = c->trans_mod->zc_request(c, req, uidata, uodata,
852				       inlen, olen, in_hdrlen);
853	if (err < 0) {
854		if (err == -EIO)
855			c->status = Disconnected;
856		if (err != -ERESTARTSYS)
857			goto recalc_sigpending;
858	}
859	if (req->status == REQ_STATUS_ERROR) {
860		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
861		err = req->t_err;
862	}
863	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
864		p9_debug(P9_DEBUG_MUX, "flushing\n");
865		sigpending = 1;
866		clear_thread_flag(TIF_SIGPENDING);
867
868		if (c->trans_mod->cancel(c, req))
869			p9_client_flush(c, req);
870
871		/* if we received the response anyway, don't signal error */
872		if (req->status == REQ_STATUS_RCVD)
873			err = 0;
874	}
875recalc_sigpending:
876	if (sigpending) {
877		spin_lock_irqsave(&current->sighand->siglock, flags);
878		recalc_sigpending();
879		spin_unlock_irqrestore(&current->sighand->siglock, flags);
880	}
881	if (err < 0)
882		goto reterr;
883
884	err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
885	trace_9p_client_res(c, type, req->rc.tag, err);
886	if (!err)
887		return req;
888reterr:
889	p9_tag_remove(c, req);
890	return ERR_PTR(safe_errno(err));
891}
892
893static struct p9_fid *p9_fid_create(struct p9_client *clnt)
894{
895	int ret;
896	struct p9_fid *fid;
897
898	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
899	fid = kzalloc(sizeof(struct p9_fid), GFP_KERNEL);
900	if (!fid)
901		return NULL;
902
903	fid->mode = -1;
904	fid->uid = current_fsuid();
905	fid->clnt = clnt;
906
907	idr_preload(GFP_KERNEL);
908	spin_lock_irq(&clnt->lock);
909	ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
910			    GFP_NOWAIT);
911	spin_unlock_irq(&clnt->lock);
912	idr_preload_end();
913
914	if (!ret)
915		return fid;
916
917	kfree(fid);
918	return NULL;
919}
920
921static void p9_fid_destroy(struct p9_fid *fid)
922{
923	struct p9_client *clnt;
924	unsigned long flags;
925
926	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
927	clnt = fid->clnt;
928	spin_lock_irqsave(&clnt->lock, flags);
929	idr_remove(&clnt->fids, fid->fid);
930	spin_unlock_irqrestore(&clnt->lock, flags);
931	kfree(fid->rdir);
932	kfree(fid);
933}
934
935static int p9_client_version(struct p9_client *c)
936{
937	int err = 0;
938	struct p9_req_t *req;
939	char *version = NULL;
940	int msize;
941
942	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
943		 c->msize, c->proto_version);
944
945	switch (c->proto_version) {
946	case p9_proto_2000L:
947		req = p9_client_rpc(c, P9_TVERSION, "ds",
948					c->msize, "9P2000.L");
949		break;
950	case p9_proto_2000u:
951		req = p9_client_rpc(c, P9_TVERSION, "ds",
952					c->msize, "9P2000.u");
953		break;
954	case p9_proto_legacy:
955		req = p9_client_rpc(c, P9_TVERSION, "ds",
956					c->msize, "9P2000");
957		break;
958	default:
959		return -EINVAL;
960	}
961
962	if (IS_ERR(req))
963		return PTR_ERR(req);
964
965	err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version);
966	if (err) {
967		p9_debug(P9_DEBUG_9P, "version error %d\n", err);
968		trace_9p_protocol_dump(c, &req->rc);
969		goto error;
970	}
971
972	p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
973	if (!strncmp(version, "9P2000.L", 8))
974		c->proto_version = p9_proto_2000L;
975	else if (!strncmp(version, "9P2000.u", 8))
976		c->proto_version = p9_proto_2000u;
977	else if (!strncmp(version, "9P2000", 6))
978		c->proto_version = p9_proto_legacy;
979	else {
980		p9_debug(P9_DEBUG_ERROR,
981			 "server returned an unknown version: %s\n", version);
982		err = -EREMOTEIO;
983		goto error;
984	}
985
986	if (msize < 4096) {
987		p9_debug(P9_DEBUG_ERROR,
988			 "server returned a msize < 4096: %d\n", msize);
989		err = -EREMOTEIO;
990		goto error;
991	}
992	if (msize < c->msize)
993		c->msize = msize;
994
995error:
996	kfree(version);
997	p9_tag_remove(c, req);
998
999	return err;
1000}
1001
1002struct p9_client *p9_client_create(const char *dev_name, char *options)
1003{
1004	int err;
1005	struct p9_client *clnt;
1006	char *client_id;
1007
1008	err = 0;
1009	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1010	if (!clnt)
1011		return ERR_PTR(-ENOMEM);
1012
1013	clnt->trans_mod = NULL;
1014	clnt->trans = NULL;
1015	clnt->fcall_cache = NULL;
1016
1017	client_id = utsname()->nodename;
1018	memcpy(clnt->name, client_id, strlen(client_id) + 1);
1019
1020	spin_lock_init(&clnt->lock);
1021	idr_init(&clnt->fids);
1022	idr_init(&clnt->reqs);
1023
1024	err = parse_opts(options, clnt);
1025	if (err < 0)
1026		goto free_client;
1027
1028	if (!clnt->trans_mod)
1029		clnt->trans_mod = v9fs_get_default_trans();
1030
1031	if (clnt->trans_mod == NULL) {
1032		err = -EPROTONOSUPPORT;
1033		p9_debug(P9_DEBUG_ERROR,
1034			 "No transport defined or default transport\n");
1035		goto free_client;
1036	}
1037
1038	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1039		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1040
1041	err = clnt->trans_mod->create(clnt, dev_name, options);
1042	if (err)
1043		goto put_trans;
1044
1045	if (clnt->msize > clnt->trans_mod->maxsize)
1046		clnt->msize = clnt->trans_mod->maxsize;
1047
1048	if (clnt->msize < 4096) {
1049		p9_debug(P9_DEBUG_ERROR,
1050			 "Please specify a msize of at least 4k\n");
1051		err = -EINVAL;
1052		goto close_trans;
1053	}
1054
1055	err = p9_client_version(clnt);
1056	if (err)
1057		goto close_trans;
1058
1059	/* P9_HDRSZ + 4 is the smallest packet header we can have that is
1060	 * followed by data accessed from userspace by read
1061	 */
1062	clnt->fcall_cache =
1063		kmem_cache_create_usercopy("9p-fcall-cache", clnt->msize,
1064					   0, 0, P9_HDRSZ + 4,
1065					   clnt->msize - (P9_HDRSZ + 4),
1066					   NULL);
1067
1068	return clnt;
1069
1070close_trans:
1071	clnt->trans_mod->close(clnt);
1072put_trans:
1073	v9fs_put_trans(clnt->trans_mod);
1074free_client:
1075	kfree(clnt);
1076	return ERR_PTR(err);
1077}
1078EXPORT_SYMBOL(p9_client_create);
1079
1080void p9_client_destroy(struct p9_client *clnt)
1081{
1082	struct p9_fid *fid;
1083	int id;
1084
1085	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1086
1087	if (clnt->trans_mod)
1088		clnt->trans_mod->close(clnt);
1089
1090	v9fs_put_trans(clnt->trans_mod);
1091
1092	idr_for_each_entry(&clnt->fids, fid, id) {
1093		pr_info("Found fid %d not clunked\n", fid->fid);
1094		p9_fid_destroy(fid);
1095	}
1096
1097	p9_tag_cleanup(clnt);
1098
1099	kmem_cache_destroy(clnt->fcall_cache);
1100	kfree(clnt);
1101}
1102EXPORT_SYMBOL(p9_client_destroy);
1103
1104void p9_client_disconnect(struct p9_client *clnt)
1105{
1106	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1107	clnt->status = Disconnected;
1108}
1109EXPORT_SYMBOL(p9_client_disconnect);
1110
1111void p9_client_begin_disconnect(struct p9_client *clnt)
1112{
1113	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1114	clnt->status = BeginDisconnect;
1115}
1116EXPORT_SYMBOL(p9_client_begin_disconnect);
1117
1118struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1119	const char *uname, kuid_t n_uname, const char *aname)
1120{
1121	int err = 0;
1122	struct p9_req_t *req;
1123	struct p9_fid *fid;
1124	struct p9_qid qid;
1125
1126
1127	p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1128		 afid ? afid->fid : -1, uname, aname);
1129	fid = p9_fid_create(clnt);
1130	if (!fid) {
1131		err = -ENOMEM;
1132		goto error;
1133	}
1134	fid->uid = n_uname;
1135
1136	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1137			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1138	if (IS_ERR(req)) {
1139		err = PTR_ERR(req);
1140		goto error;
1141	}
1142
1143	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
1144	if (err) {
1145		trace_9p_protocol_dump(clnt, &req->rc);
1146		p9_tag_remove(clnt, req);
1147		goto error;
1148	}
1149
1150	p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1151		 qid.type, (unsigned long long)qid.path, qid.version);
1152
1153	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1154
1155	p9_tag_remove(clnt, req);
1156	return fid;
1157
1158error:
1159	if (fid)
1160		p9_fid_destroy(fid);
1161	return ERR_PTR(err);
1162}
1163EXPORT_SYMBOL(p9_client_attach);
1164
1165struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1166		const unsigned char * const *wnames, int clone)
1167{
1168	int err;
1169	struct p9_client *clnt;
1170	struct p9_fid *fid;
1171	struct p9_qid *wqids;
1172	struct p9_req_t *req;
1173	uint16_t nwqids, count;
1174
1175	err = 0;
1176	wqids = NULL;
1177	clnt = oldfid->clnt;
1178	if (clone) {
1179		fid = p9_fid_create(clnt);
1180		if (!fid) {
1181			err = -ENOMEM;
1182			goto error;
1183		}
1184
1185		fid->uid = oldfid->uid;
1186	} else
1187		fid = oldfid;
1188
1189
1190	p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1191		 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1192
1193	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1194								nwname, wnames);
1195	if (IS_ERR(req)) {
1196		err = PTR_ERR(req);
1197		goto error;
1198	}
1199
1200	err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1201	if (err) {
1202		trace_9p_protocol_dump(clnt, &req->rc);
1203		p9_tag_remove(clnt, req);
1204		goto clunk_fid;
1205	}
1206	p9_tag_remove(clnt, req);
1207
1208	p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1209
1210	if (nwqids != nwname) {
1211		err = -ENOENT;
1212		goto clunk_fid;
1213	}
1214
1215	for (count = 0; count < nwqids; count++)
1216		p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1217			count, wqids[count].type,
1218			(unsigned long long)wqids[count].path,
1219			wqids[count].version);
1220
1221	if (nwname)
1222		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1223	else
1224		fid->qid = oldfid->qid;
1225
1226	kfree(wqids);
1227	return fid;
1228
1229clunk_fid:
1230	kfree(wqids);
1231	p9_client_clunk(fid);
1232	fid = NULL;
1233
1234error:
1235	if (fid && (fid != oldfid))
1236		p9_fid_destroy(fid);
1237
1238	return ERR_PTR(err);
1239}
1240EXPORT_SYMBOL(p9_client_walk);
1241
1242int p9_client_open(struct p9_fid *fid, int mode)
1243{
1244	int err;
1245	struct p9_client *clnt;
1246	struct p9_req_t *req;
1247	struct p9_qid qid;
1248	int iounit;
1249
1250	clnt = fid->clnt;
1251	p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1252		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1253	err = 0;
1254
1255	if (fid->mode != -1)
1256		return -EINVAL;
1257
1258	if (p9_is_proto_dotl(clnt))
1259		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1260	else
1261		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1262	if (IS_ERR(req)) {
1263		err = PTR_ERR(req);
1264		goto error;
1265	}
1266
1267	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1268	if (err) {
1269		trace_9p_protocol_dump(clnt, &req->rc);
1270		goto free_and_error;
1271	}
1272
1273	p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1274		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1275		(unsigned long long)qid.path, qid.version, iounit);
1276
1277	fid->mode = mode;
1278	fid->iounit = iounit;
1279
1280free_and_error:
1281	p9_tag_remove(clnt, req);
1282error:
1283	return err;
1284}
1285EXPORT_SYMBOL(p9_client_open);
1286
1287int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1288		kgid_t gid, struct p9_qid *qid)
1289{
1290	int err = 0;
1291	struct p9_client *clnt;
1292	struct p9_req_t *req;
1293	int iounit;
1294
1295	p9_debug(P9_DEBUG_9P,
1296			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1297			ofid->fid, name, flags, mode,
1298		 	from_kgid(&init_user_ns, gid));
1299	clnt = ofid->clnt;
1300
1301	if (ofid->mode != -1)
1302		return -EINVAL;
1303
1304	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1305			mode, gid);
1306	if (IS_ERR(req)) {
1307		err = PTR_ERR(req);
1308		goto error;
1309	}
1310
1311	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
1312	if (err) {
1313		trace_9p_protocol_dump(clnt, &req->rc);
1314		goto free_and_error;
1315	}
1316
1317	p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1318			qid->type,
1319			(unsigned long long)qid->path,
1320			qid->version, iounit);
1321
1322	ofid->mode = mode;
1323	ofid->iounit = iounit;
1324
1325free_and_error:
1326	p9_tag_remove(clnt, req);
1327error:
1328	return err;
1329}
1330EXPORT_SYMBOL(p9_client_create_dotl);
1331
1332int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1333		     char *extension)
1334{
1335	int err;
1336	struct p9_client *clnt;
1337	struct p9_req_t *req;
1338	struct p9_qid qid;
1339	int iounit;
1340
1341	p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1342						fid->fid, name, perm, mode);
1343	err = 0;
1344	clnt = fid->clnt;
1345
1346	if (fid->mode != -1)
1347		return -EINVAL;
1348
1349	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1350				mode, extension);
1351	if (IS_ERR(req)) {
1352		err = PTR_ERR(req);
1353		goto error;
1354	}
1355
1356	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1357	if (err) {
1358		trace_9p_protocol_dump(clnt, &req->rc);
1359		goto free_and_error;
1360	}
1361
1362	p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1363				qid.type,
1364				(unsigned long long)qid.path,
1365				qid.version, iounit);
1366
1367	fid->mode = mode;
1368	fid->iounit = iounit;
1369
1370free_and_error:
1371	p9_tag_remove(clnt, req);
1372error:
1373	return err;
1374}
1375EXPORT_SYMBOL(p9_client_fcreate);
1376
1377int p9_client_symlink(struct p9_fid *dfid, const char *name,
1378		const char *symtgt, kgid_t gid, struct p9_qid *qid)
1379{
1380	int err = 0;
1381	struct p9_client *clnt;
1382	struct p9_req_t *req;
1383
1384	p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1385			dfid->fid, name, symtgt);
1386	clnt = dfid->clnt;
1387
1388	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1389			gid);
1390	if (IS_ERR(req)) {
1391		err = PTR_ERR(req);
1392		goto error;
1393	}
1394
1395	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
1396	if (err) {
1397		trace_9p_protocol_dump(clnt, &req->rc);
1398		goto free_and_error;
1399	}
1400
1401	p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1402			qid->type, (unsigned long long)qid->path, qid->version);
1403
1404free_and_error:
1405	p9_tag_remove(clnt, req);
1406error:
1407	return err;
1408}
1409EXPORT_SYMBOL(p9_client_symlink);
1410
1411int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1412{
1413	struct p9_client *clnt;
1414	struct p9_req_t *req;
1415
1416	p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1417			dfid->fid, oldfid->fid, newname);
1418	clnt = dfid->clnt;
1419	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1420			newname);
1421	if (IS_ERR(req))
1422		return PTR_ERR(req);
1423
1424	p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1425	p9_tag_remove(clnt, req);
1426	return 0;
1427}
1428EXPORT_SYMBOL(p9_client_link);
1429
1430int p9_client_fsync(struct p9_fid *fid, int datasync)
1431{
1432	int err;
1433	struct p9_client *clnt;
1434	struct p9_req_t *req;
1435
1436	p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1437			fid->fid, datasync);
1438	err = 0;
1439	clnt = fid->clnt;
1440
1441	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1442	if (IS_ERR(req)) {
1443		err = PTR_ERR(req);
1444		goto error;
1445	}
1446
1447	p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1448
1449	p9_tag_remove(clnt, req);
1450
1451error:
1452	return err;
1453}
1454EXPORT_SYMBOL(p9_client_fsync);
1455
1456int p9_client_clunk(struct p9_fid *fid)
1457{
1458	int err;
1459	struct p9_client *clnt;
1460	struct p9_req_t *req;
1461	int retries = 0;
1462
1463	if (!fid) {
1464		pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1465			__func__, task_pid_nr(current));
1466		dump_stack();
1467		return 0;
1468	}
1469
1470again:
1471	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1472								retries);
1473	err = 0;
1474	clnt = fid->clnt;
1475
1476	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1477	if (IS_ERR(req)) {
1478		err = PTR_ERR(req);
1479		goto error;
1480	}
1481
1482	p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1483
1484	p9_tag_remove(clnt, req);
1485error:
1486	/*
1487	 * Fid is not valid even after a failed clunk
1488	 * If interrupted, retry once then give up and
1489	 * leak fid until umount.
1490	 */
1491	if (err == -ERESTARTSYS) {
1492		if (retries++ == 0)
1493			goto again;
1494	} else
1495		p9_fid_destroy(fid);
1496	return err;
1497}
1498EXPORT_SYMBOL(p9_client_clunk);
1499
1500int p9_client_remove(struct p9_fid *fid)
1501{
1502	int err;
1503	struct p9_client *clnt;
1504	struct p9_req_t *req;
1505
1506	p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1507	err = 0;
1508	clnt = fid->clnt;
1509
1510	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1511	if (IS_ERR(req)) {
1512		err = PTR_ERR(req);
1513		goto error;
1514	}
1515
1516	p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1517
1518	p9_tag_remove(clnt, req);
1519error:
1520	if (err == -ERESTARTSYS)
1521		p9_client_clunk(fid);
1522	else
1523		p9_fid_destroy(fid);
1524	return err;
1525}
1526EXPORT_SYMBOL(p9_client_remove);
1527
1528int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1529{
1530	int err = 0;
1531	struct p9_req_t *req;
1532	struct p9_client *clnt;
1533
1534	p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1535		   dfid->fid, name, flags);
1536
1537	clnt = dfid->clnt;
1538	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1539	if (IS_ERR(req)) {
1540		err = PTR_ERR(req);
1541		goto error;
1542	}
1543	p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1544
1545	p9_tag_remove(clnt, req);
1546error:
1547	return err;
1548}
1549EXPORT_SYMBOL(p9_client_unlinkat);
1550
1551int
1552p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1553{
1554	int total = 0;
1555	*err = 0;
1556
1557	while (iov_iter_count(to)) {
1558		int count;
1559
1560		count = p9_client_read_once(fid, offset, to, err);
1561		if (!count || *err)
1562			break;
1563		offset += count;
1564		total += count;
1565	}
1566	return total;
1567}
1568EXPORT_SYMBOL(p9_client_read);
1569
1570int
1571p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
1572		    int *err)
1573{
1574	struct p9_client *clnt = fid->clnt;
1575	struct p9_req_t *req;
1576	int count = iov_iter_count(to);
1577	int rsize, non_zc = 0;
1578	char *dataptr;
1579
1580	*err = 0;
1581	p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1582		   fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1583
1584	rsize = fid->iounit;
1585	if (!rsize || rsize > clnt->msize - P9_IOHDRSZ)
1586		rsize = clnt->msize - P9_IOHDRSZ;
1587
1588	if (count < rsize)
1589		rsize = count;
1590
1591	/* Don't bother zerocopy for small IO (< 1024) */
1592	if (clnt->trans_mod->zc_request && rsize > 1024) {
1593		/* response header len is 11
1594		 * PDU Header(7) + IO Size (4)
1595		 */
1596		req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1597				       0, 11, "dqd", fid->fid,
1598				       offset, rsize);
1599	} else {
1600		non_zc = 1;
1601		req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1602				    rsize);
1603	}
1604	if (IS_ERR(req)) {
1605		*err = PTR_ERR(req);
1606		return 0;
1607	}
1608
1609	*err = p9pdu_readf(&req->rc, clnt->proto_version,
1610			   "D", &count, &dataptr);
1611	if (*err) {
1612		trace_9p_protocol_dump(clnt, &req->rc);
1613		p9_tag_remove(clnt, req);
1614		return 0;
1615	}
1616	if (rsize < count) {
1617		pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1618		count = rsize;
1619	}
1620
1621	p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1622
1623	if (non_zc) {
1624		int n = copy_to_iter(dataptr, count, to);
1625
1626		if (n != count) {
1627			*err = -EFAULT;
1628			p9_tag_remove(clnt, req);
1629			return n;
1630		}
1631	} else {
1632		iov_iter_advance(to, count);
1633	}
1634	p9_tag_remove(clnt, req);
1635	return count;
1636}
1637EXPORT_SYMBOL(p9_client_read_once);
1638
1639int
1640p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1641{
1642	struct p9_client *clnt = fid->clnt;
1643	struct p9_req_t *req;
1644	int total = 0;
1645	*err = 0;
1646
1647	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1648				fid->fid, (unsigned long long) offset,
1649				iov_iter_count(from));
1650
1651	while (iov_iter_count(from)) {
1652		int count = iov_iter_count(from);
1653		int rsize = fid->iounit;
1654		if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1655			rsize = clnt->msize - P9_IOHDRSZ;
1656
1657		if (count < rsize)
1658			rsize = count;
1659
1660		/* Don't bother zerocopy for small IO (< 1024) */
1661		if (clnt->trans_mod->zc_request && rsize > 1024) {
1662			req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1663					       rsize, P9_ZC_HDR_SZ, "dqd",
1664					       fid->fid, offset, rsize);
1665		} else {
1666			req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1667						    offset, rsize, from);
1668		}
1669		if (IS_ERR(req)) {
1670			*err = PTR_ERR(req);
1671			break;
1672		}
1673
1674		*err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count);
1675		if (*err) {
1676			trace_9p_protocol_dump(clnt, &req->rc);
1677			p9_tag_remove(clnt, req);
1678			break;
1679		}
1680		if (rsize < count) {
1681			pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1682			count = rsize;
1683		}
1684
1685		p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1686
1687		p9_tag_remove(clnt, req);
1688		iov_iter_advance(from, count);
1689		total += count;
1690		offset += count;
1691	}
1692	return total;
1693}
1694EXPORT_SYMBOL(p9_client_write);
1695
1696struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1697{
1698	int err;
1699	struct p9_client *clnt;
1700	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1701	struct p9_req_t *req;
1702	u16 ignored;
1703
1704	p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1705
1706	if (!ret)
1707		return ERR_PTR(-ENOMEM);
1708
1709	err = 0;
1710	clnt = fid->clnt;
1711
1712	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1713	if (IS_ERR(req)) {
1714		err = PTR_ERR(req);
1715		goto error;
1716	}
1717
1718	err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
1719	if (err) {
1720		trace_9p_protocol_dump(clnt, &req->rc);
1721		p9_tag_remove(clnt, req);
1722		goto error;
1723	}
1724
1725	p9_debug(P9_DEBUG_9P,
1726		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1727		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1728		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1729		"<<<    uid=%d gid=%d n_muid=%d\n",
1730		ret->size, ret->type, ret->dev, ret->qid.type,
1731		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1732		ret->atime, ret->mtime, (unsigned long long)ret->length,
1733		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1734		from_kuid(&init_user_ns, ret->n_uid),
1735		from_kgid(&init_user_ns, ret->n_gid),
1736		from_kuid(&init_user_ns, ret->n_muid));
1737
1738	p9_tag_remove(clnt, req);
1739	return ret;
1740
1741error:
1742	kfree(ret);
1743	return ERR_PTR(err);
1744}
1745EXPORT_SYMBOL(p9_client_stat);
1746
1747struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1748							u64 request_mask)
1749{
1750	int err;
1751	struct p9_client *clnt;
1752	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1753								GFP_KERNEL);
1754	struct p9_req_t *req;
1755
1756	p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1757							fid->fid, request_mask);
1758
1759	if (!ret)
1760		return ERR_PTR(-ENOMEM);
1761
1762	err = 0;
1763	clnt = fid->clnt;
1764
1765	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1766	if (IS_ERR(req)) {
1767		err = PTR_ERR(req);
1768		goto error;
1769	}
1770
1771	err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
1772	if (err) {
1773		trace_9p_protocol_dump(clnt, &req->rc);
1774		p9_tag_remove(clnt, req);
1775		goto error;
1776	}
1777
1778	p9_debug(P9_DEBUG_9P,
1779		"<<< RGETATTR st_result_mask=%lld\n"
1780		"<<< qid=%x.%llx.%x\n"
1781		"<<< st_mode=%8.8x st_nlink=%llu\n"
1782		"<<< st_uid=%d st_gid=%d\n"
1783		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1784		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1785		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1786		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1787		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1788		"<<< st_gen=%lld st_data_version=%lld\n",
1789		ret->st_result_mask, ret->qid.type, ret->qid.path,
1790		ret->qid.version, ret->st_mode, ret->st_nlink,
1791		from_kuid(&init_user_ns, ret->st_uid),
1792		from_kgid(&init_user_ns, ret->st_gid),
1793		ret->st_rdev, ret->st_size, ret->st_blksize,
1794		ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1795		ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1796		ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1797		ret->st_gen, ret->st_data_version);
1798
1799	p9_tag_remove(clnt, req);
1800	return ret;
1801
1802error:
1803	kfree(ret);
1804	return ERR_PTR(err);
1805}
1806EXPORT_SYMBOL(p9_client_getattr_dotl);
1807
1808static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1809{
1810	int ret;
1811
1812	/* NOTE: size shouldn't include its own length */
1813	/* size[2] type[2] dev[4] qid[13] */
1814	/* mode[4] atime[4] mtime[4] length[8]*/
1815	/* name[s] uid[s] gid[s] muid[s] */
1816	ret = 2+4+13+4+4+4+8+2+2+2+2;
1817
1818	if (wst->name)
1819		ret += strlen(wst->name);
1820	if (wst->uid)
1821		ret += strlen(wst->uid);
1822	if (wst->gid)
1823		ret += strlen(wst->gid);
1824	if (wst->muid)
1825		ret += strlen(wst->muid);
1826
1827	if ((proto_version == p9_proto_2000u) ||
1828		(proto_version == p9_proto_2000L)) {
1829		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1830		if (wst->extension)
1831			ret += strlen(wst->extension);
1832	}
1833
1834	return ret;
1835}
1836
1837int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1838{
1839	int err;
1840	struct p9_req_t *req;
1841	struct p9_client *clnt;
1842
1843	err = 0;
1844	clnt = fid->clnt;
1845	wst->size = p9_client_statsize(wst, clnt->proto_version);
1846	p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1847	p9_debug(P9_DEBUG_9P,
1848		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1849		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1850		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1851		"     uid=%d gid=%d n_muid=%d\n",
1852		wst->size, wst->type, wst->dev, wst->qid.type,
1853		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1854		wst->atime, wst->mtime, (unsigned long long)wst->length,
1855		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1856		from_kuid(&init_user_ns, wst->n_uid),
1857		from_kgid(&init_user_ns, wst->n_gid),
1858		from_kuid(&init_user_ns, wst->n_muid));
1859
1860	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1861	if (IS_ERR(req)) {
1862		err = PTR_ERR(req);
1863		goto error;
1864	}
1865
1866	p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1867
1868	p9_tag_remove(clnt, req);
1869error:
1870	return err;
1871}
1872EXPORT_SYMBOL(p9_client_wstat);
1873
1874int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1875{
1876	int err;
1877	struct p9_req_t *req;
1878	struct p9_client *clnt;
1879
1880	err = 0;
1881	clnt = fid->clnt;
1882	p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1883	p9_debug(P9_DEBUG_9P,
1884		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1885		"    atime_sec=%lld atime_nsec=%lld\n"
1886		"    mtime_sec=%lld mtime_nsec=%lld\n",
1887		p9attr->valid, p9attr->mode,
1888		from_kuid(&init_user_ns, p9attr->uid),
1889		from_kgid(&init_user_ns, p9attr->gid),
1890		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1891		p9attr->mtime_sec, p9attr->mtime_nsec);
1892
1893	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1894
1895	if (IS_ERR(req)) {
1896		err = PTR_ERR(req);
1897		goto error;
1898	}
1899	p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1900	p9_tag_remove(clnt, req);
1901error:
1902	return err;
1903}
1904EXPORT_SYMBOL(p9_client_setattr);
1905
1906int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1907{
1908	int err;
1909	struct p9_req_t *req;
1910	struct p9_client *clnt;
1911
1912	err = 0;
1913	clnt = fid->clnt;
1914
1915	p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1916
1917	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1918	if (IS_ERR(req)) {
1919		err = PTR_ERR(req);
1920		goto error;
1921	}
1922
1923	err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1924			  &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1925			  &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1926	if (err) {
1927		trace_9p_protocol_dump(clnt, &req->rc);
1928		p9_tag_remove(clnt, req);
1929		goto error;
1930	}
1931
1932	p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1933		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1934		"fsid %llu namelen %ld\n",
1935		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1936		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1937		sb->fsid, (long int)sb->namelen);
1938
1939	p9_tag_remove(clnt, req);
1940error:
1941	return err;
1942}
1943EXPORT_SYMBOL(p9_client_statfs);
1944
1945int p9_client_rename(struct p9_fid *fid,
1946		     struct p9_fid *newdirfid, const char *name)
1947{
1948	int err;
1949	struct p9_req_t *req;
1950	struct p9_client *clnt;
1951
1952	err = 0;
1953	clnt = fid->clnt;
1954
1955	p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1956			fid->fid, newdirfid->fid, name);
1957
1958	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1959			newdirfid->fid, name);
1960	if (IS_ERR(req)) {
1961		err = PTR_ERR(req);
1962		goto error;
1963	}
1964
1965	p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1966
1967	p9_tag_remove(clnt, req);
1968error:
1969	return err;
1970}
1971EXPORT_SYMBOL(p9_client_rename);
1972
1973int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1974		       struct p9_fid *newdirfid, const char *new_name)
1975{
1976	int err;
1977	struct p9_req_t *req;
1978	struct p9_client *clnt;
1979
1980	err = 0;
1981	clnt = olddirfid->clnt;
1982
1983	p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1984		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1985		   newdirfid->fid, new_name);
1986
1987	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1988			    old_name, newdirfid->fid, new_name);
1989	if (IS_ERR(req)) {
1990		err = PTR_ERR(req);
1991		goto error;
1992	}
1993
1994	p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1995		   newdirfid->fid, new_name);
1996
1997	p9_tag_remove(clnt, req);
1998error:
1999	return err;
2000}
2001EXPORT_SYMBOL(p9_client_renameat);
2002
2003/*
2004 * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2005 */
2006struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2007				const char *attr_name, u64 *attr_size)
2008{
2009	int err;
2010	struct p9_req_t *req;
2011	struct p9_client *clnt;
2012	struct p9_fid *attr_fid;
2013
2014	err = 0;
2015	clnt = file_fid->clnt;
2016	attr_fid = p9_fid_create(clnt);
2017	if (!attr_fid) {
2018		err = -ENOMEM;
2019		goto error;
2020	}
2021	p9_debug(P9_DEBUG_9P,
2022		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2023		file_fid->fid, attr_fid->fid, attr_name);
2024
2025	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2026			file_fid->fid, attr_fid->fid, attr_name);
2027	if (IS_ERR(req)) {
2028		err = PTR_ERR(req);
2029		goto error;
2030	}
2031	err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
2032	if (err) {
2033		trace_9p_protocol_dump(clnt, &req->rc);
2034		p9_tag_remove(clnt, req);
2035		goto clunk_fid;
2036	}
2037	p9_tag_remove(clnt, req);
2038	p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2039		attr_fid->fid, *attr_size);
2040	return attr_fid;
2041clunk_fid:
2042	p9_client_clunk(attr_fid);
2043	attr_fid = NULL;
2044error:
2045	if (attr_fid && (attr_fid != file_fid))
2046		p9_fid_destroy(attr_fid);
2047
2048	return ERR_PTR(err);
2049}
2050EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2051
2052int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2053			u64 attr_size, int flags)
2054{
2055	int err;
2056	struct p9_req_t *req;
2057	struct p9_client *clnt;
2058
2059	p9_debug(P9_DEBUG_9P,
2060		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2061		fid->fid, name, (long long)attr_size, flags);
2062	err = 0;
2063	clnt = fid->clnt;
2064	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2065			fid->fid, name, attr_size, flags);
2066	if (IS_ERR(req)) {
2067		err = PTR_ERR(req);
2068		goto error;
2069	}
2070	p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2071	p9_tag_remove(clnt, req);
2072error:
2073	return err;
2074}
2075EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2076
2077int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2078{
2079	int err, rsize, non_zc = 0;
2080	struct p9_client *clnt;
2081	struct p9_req_t *req;
2082	char *dataptr;
2083	struct kvec kv = {.iov_base = data, .iov_len = count};
2084	struct iov_iter to;
2085
2086	iov_iter_kvec(&to, READ, &kv, 1, count);
2087
2088	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2089				fid->fid, (unsigned long long) offset, count);
2090
2091	err = 0;
2092	clnt = fid->clnt;
2093
2094	rsize = fid->iounit;
2095	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2096		rsize = clnt->msize - P9_READDIRHDRSZ;
2097
2098	if (count < rsize)
2099		rsize = count;
2100
2101	/* Don't bother zerocopy for small IO (< 1024) */
2102	if (clnt->trans_mod->zc_request && rsize > 1024) {
2103		/*
2104		 * response header len is 11
2105		 * PDU Header(7) + IO Size (4)
2106		 */
2107		req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2108				       11, "dqd", fid->fid, offset, rsize);
2109	} else {
2110		non_zc = 1;
2111		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2112				    offset, rsize);
2113	}
2114	if (IS_ERR(req)) {
2115		err = PTR_ERR(req);
2116		goto error;
2117	}
2118
2119	err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
2120	if (err) {
2121		trace_9p_protocol_dump(clnt, &req->rc);
2122		goto free_and_error;
2123	}
2124	if (rsize < count) {
2125		pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2126		count = rsize;
2127	}
2128
2129	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2130
2131	if (non_zc)
2132		memmove(data, dataptr, count);
2133
2134	p9_tag_remove(clnt, req);
2135	return count;
2136
2137free_and_error:
2138	p9_tag_remove(clnt, req);
2139error:
2140	return err;
2141}
2142EXPORT_SYMBOL(p9_client_readdir);
2143
2144int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2145			dev_t rdev, kgid_t gid, struct p9_qid *qid)
2146{
2147	int err;
2148	struct p9_client *clnt;
2149	struct p9_req_t *req;
2150
2151	err = 0;
2152	clnt = fid->clnt;
2153	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2154		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2155	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2156		MAJOR(rdev), MINOR(rdev), gid);
2157	if (IS_ERR(req))
2158		return PTR_ERR(req);
2159
2160	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2161	if (err) {
2162		trace_9p_protocol_dump(clnt, &req->rc);
2163		goto error;
2164	}
2165	p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2166				(unsigned long long)qid->path, qid->version);
2167
2168error:
2169	p9_tag_remove(clnt, req);
2170	return err;
2171
2172}
2173EXPORT_SYMBOL(p9_client_mknod_dotl);
2174
2175int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2176				kgid_t gid, struct p9_qid *qid)
2177{
2178	int err;
2179	struct p9_client *clnt;
2180	struct p9_req_t *req;
2181
2182	err = 0;
2183	clnt = fid->clnt;
2184	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2185		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2186	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2187		gid);
2188	if (IS_ERR(req))
2189		return PTR_ERR(req);
2190
2191	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2192	if (err) {
2193		trace_9p_protocol_dump(clnt, &req->rc);
2194		goto error;
2195	}
2196	p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2197				(unsigned long long)qid->path, qid->version);
2198
2199error:
2200	p9_tag_remove(clnt, req);
2201	return err;
2202
2203}
2204EXPORT_SYMBOL(p9_client_mkdir_dotl);
2205
2206int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2207{
2208	int err;
2209	struct p9_client *clnt;
2210	struct p9_req_t *req;
2211
2212	err = 0;
2213	clnt = fid->clnt;
2214	p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2215			"start %lld length %lld proc_id %d client_id %s\n",
2216			fid->fid, flock->type, flock->flags, flock->start,
2217			flock->length, flock->proc_id, flock->client_id);
2218
2219	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2220				flock->flags, flock->start, flock->length,
2221					flock->proc_id, flock->client_id);
2222
2223	if (IS_ERR(req))
2224		return PTR_ERR(req);
2225
2226	err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
2227	if (err) {
2228		trace_9p_protocol_dump(clnt, &req->rc);
2229		goto error;
2230	}
2231	p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2232error:
2233	p9_tag_remove(clnt, req);
2234	return err;
2235
2236}
2237EXPORT_SYMBOL(p9_client_lock_dotl);
2238
2239int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2240{
2241	int err;
2242	struct p9_client *clnt;
2243	struct p9_req_t *req;
2244
2245	err = 0;
2246	clnt = fid->clnt;
2247	p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2248		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2249		glock->start, glock->length, glock->proc_id, glock->client_id);
2250
2251	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2252		glock->start, glock->length, glock->proc_id, glock->client_id);
2253
2254	if (IS_ERR(req))
2255		return PTR_ERR(req);
2256
2257	err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type,
2258			  &glock->start, &glock->length, &glock->proc_id,
2259			  &glock->client_id);
2260	if (err) {
2261		trace_9p_protocol_dump(clnt, &req->rc);
2262		goto error;
2263	}
2264	p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2265		"proc_id %d client_id %s\n", glock->type, glock->start,
2266		glock->length, glock->proc_id, glock->client_id);
2267error:
2268	p9_tag_remove(clnt, req);
2269	return err;
2270}
2271EXPORT_SYMBOL(p9_client_getlock_dotl);
2272
2273int p9_client_readlink(struct p9_fid *fid, char **target)
2274{
2275	int err;
2276	struct p9_client *clnt;
2277	struct p9_req_t *req;
2278
2279	err = 0;
2280	clnt = fid->clnt;
2281	p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2282
2283	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2284	if (IS_ERR(req))
2285		return PTR_ERR(req);
2286
2287	err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
2288	if (err) {
2289		trace_9p_protocol_dump(clnt, &req->rc);
2290		goto error;
2291	}
2292	p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2293error:
2294	p9_tag_remove(clnt, req);
2295	return err;
2296}
2297EXPORT_SYMBOL(p9_client_readlink);
2298
2299int __init p9_client_init(void)
2300{
2301	p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU);
2302	return p9_req_cache ? 0 : -ENOMEM;
2303}
2304
2305void __exit p9_client_exit(void)
2306{
2307	kmem_cache_destroy(p9_req_cache);
2308}
2309