client.c revision 5a0e3ad6af8660be21ca98a971cd00f331318c05
1/*
2 * net/9p/clnt.c
3 *
4 * 9P Client
5 *
6 *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
7 *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
8 *
9 *  This program is free software; you can redistribute it and/or modify
10 *  it under the terms of the GNU General Public License version 2
11 *  as published by the Free Software Foundation.
12 *
13 *  This program is distributed in the hope that it will be useful,
14 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 *  GNU General Public License for more details.
17 *
18 *  You should have received a copy of the GNU General Public License
19 *  along with this program; if not, write to:
20 *  Free Software Foundation
21 *  51 Franklin Street, Fifth Floor
22 *  Boston, MA  02111-1301  USA
23 *
24 */
25
26#include <linux/module.h>
27#include <linux/errno.h>
28#include <linux/fs.h>
29#include <linux/poll.h>
30#include <linux/idr.h>
31#include <linux/mutex.h>
32#include <linux/slab.h>
33#include <linux/sched.h>
34#include <linux/uaccess.h>
35#include <net/9p/9p.h>
36#include <linux/parser.h>
37#include <net/9p/client.h>
38#include <net/9p/transport.h>
39#include "protocol.h"
40
41/*
42  * Client Option Parsing (code inspired by NFS code)
43  *  - a little lazy - parse all client options
44  */
45
46enum {
47	Opt_msize,
48	Opt_trans,
49	Opt_legacy,
50	Opt_version,
51	Opt_err,
52};
53
54static const match_table_t tokens = {
55	{Opt_msize, "msize=%u"},
56	{Opt_legacy, "noextend"},
57	{Opt_trans, "trans=%s"},
58	{Opt_version, "version=%s"},
59	{Opt_err, NULL},
60};
61
62inline int p9_is_proto_dotl(struct p9_client *clnt)
63{
64	return (clnt->proto_version == p9_proto_2000L);
65}
66EXPORT_SYMBOL(p9_is_proto_dotl);
67
68inline int p9_is_proto_dotu(struct p9_client *clnt)
69{
70	return (clnt->proto_version == p9_proto_2000u);
71}
72EXPORT_SYMBOL(p9_is_proto_dotu);
73
74/* Interpret mount option for protocol version */
75static unsigned char get_protocol_version(const substring_t *name)
76{
77	unsigned char version = -EINVAL;
78	if (!strncmp("9p2000", name->from, name->to-name->from)) {
79		version = p9_proto_legacy;
80		P9_DPRINTK(P9_DEBUG_9P, "Protocol version: Legacy\n");
81	} else if (!strncmp("9p2000.u", name->from, name->to-name->from)) {
82		version = p9_proto_2000u;
83		P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
84	} else if (!strncmp("9p2000.L", name->from, name->to-name->from)) {
85		version = p9_proto_2000L;
86		P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
87	} else {
88		P9_DPRINTK(P9_DEBUG_ERROR, "Unknown protocol version %s. ",
89							name->from);
90	}
91	return version;
92}
93
94static struct p9_req_t *
95p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
96
97/**
98 * parse_options - parse mount options into client structure
99 * @opts: options string passed from mount
100 * @clnt: existing v9fs client information
101 *
102 * Return 0 upon success, -ERRNO upon failure
103 */
104
105static int parse_opts(char *opts, struct p9_client *clnt)
106{
107	char *options, *tmp_options;
108	char *p;
109	substring_t args[MAX_OPT_ARGS];
110	int option;
111	int ret = 0;
112
113	clnt->proto_version = p9_proto_2000u;
114	clnt->msize = 8192;
115
116	if (!opts)
117		return 0;
118
119	tmp_options = kstrdup(opts, GFP_KERNEL);
120	if (!tmp_options) {
121		P9_DPRINTK(P9_DEBUG_ERROR,
122				"failed to allocate copy of option string\n");
123		return -ENOMEM;
124	}
125	options = tmp_options;
126
127	while ((p = strsep(&options, ",")) != NULL) {
128		int token;
129		if (!*p)
130			continue;
131		token = match_token(p, tokens, args);
132		if (token < Opt_trans) {
133			int r = match_int(&args[0], &option);
134			if (r < 0) {
135				P9_DPRINTK(P9_DEBUG_ERROR,
136					"integer field, but no integer?\n");
137				ret = r;
138				continue;
139			}
140		}
141		switch (token) {
142		case Opt_msize:
143			clnt->msize = option;
144			break;
145		case Opt_trans:
146			clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
147			if(clnt->trans_mod == NULL) {
148				P9_DPRINTK(P9_DEBUG_ERROR,
149				   "Could not find request transport: %s\n",
150				   (char *) &args[0]);
151				ret = -EINVAL;
152				goto free_and_return;
153			}
154			break;
155		case Opt_legacy:
156			clnt->proto_version = p9_proto_legacy;
157			break;
158		case Opt_version:
159			ret = get_protocol_version(&args[0]);
160			if (ret == -EINVAL)
161				goto free_and_return;
162			clnt->proto_version = ret;
163			break;
164		default:
165			continue;
166		}
167	}
168
169free_and_return:
170	kfree(tmp_options);
171	return ret;
172}
173
174/**
175 * p9_tag_alloc - lookup/allocate a request by tag
176 * @c: client session to lookup tag within
177 * @tag: numeric id for transaction
178 *
179 * this is a simple array lookup, but will grow the
180 * request_slots as necessary to accomodate transaction
181 * ids which did not previously have a slot.
182 *
183 * this code relies on the client spinlock to manage locks, its
184 * possible we should switch to something else, but I'd rather
185 * stick with something low-overhead for the common case.
186 *
187 */
188
189static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
190{
191	unsigned long flags;
192	int row, col;
193	struct p9_req_t *req;
194
195	/* This looks up the original request by tag so we know which
196	 * buffer to read the data into */
197	tag++;
198
199	if (tag >= c->max_tag) {
200		spin_lock_irqsave(&c->lock, flags);
201		/* check again since original check was outside of lock */
202		while (tag >= c->max_tag) {
203			row = (tag / P9_ROW_MAXTAG);
204			c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
205					sizeof(struct p9_req_t), GFP_ATOMIC);
206
207			if (!c->reqs[row]) {
208				printk(KERN_ERR "Couldn't grow tag array\n");
209				spin_unlock_irqrestore(&c->lock, flags);
210				return ERR_PTR(-ENOMEM);
211			}
212			for (col = 0; col < P9_ROW_MAXTAG; col++) {
213				c->reqs[row][col].status = REQ_STATUS_IDLE;
214				c->reqs[row][col].tc = NULL;
215			}
216			c->max_tag += P9_ROW_MAXTAG;
217		}
218		spin_unlock_irqrestore(&c->lock, flags);
219	}
220	row = tag / P9_ROW_MAXTAG;
221	col = tag % P9_ROW_MAXTAG;
222
223	req = &c->reqs[row][col];
224	if (!req->tc) {
225		req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
226		if (!req->wq) {
227			printk(KERN_ERR "Couldn't grow tag array\n");
228			return ERR_PTR(-ENOMEM);
229		}
230		init_waitqueue_head(req->wq);
231		req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
232								GFP_KERNEL);
233		req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
234								GFP_KERNEL);
235		if ((!req->tc) || (!req->rc)) {
236			printk(KERN_ERR "Couldn't grow tag array\n");
237			kfree(req->tc);
238			kfree(req->rc);
239			kfree(req->wq);
240			req->tc = req->rc = NULL;
241			req->wq = NULL;
242			return ERR_PTR(-ENOMEM);
243		}
244		req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
245		req->tc->capacity = c->msize;
246		req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
247		req->rc->capacity = c->msize;
248	}
249
250	p9pdu_reset(req->tc);
251	p9pdu_reset(req->rc);
252
253	req->tc->tag = tag-1;
254	req->status = REQ_STATUS_ALLOC;
255
256	return &c->reqs[row][col];
257}
258
259/**
260 * p9_tag_lookup - lookup a request by tag
261 * @c: client session to lookup tag within
262 * @tag: numeric id for transaction
263 *
264 */
265
266struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
267{
268	int row, col;
269
270	/* This looks up the original request by tag so we know which
271	 * buffer to read the data into */
272	tag++;
273
274	BUG_ON(tag >= c->max_tag);
275
276	row = tag / P9_ROW_MAXTAG;
277	col = tag % P9_ROW_MAXTAG;
278
279	return &c->reqs[row][col];
280}
281EXPORT_SYMBOL(p9_tag_lookup);
282
283/**
284 * p9_tag_init - setup tags structure and contents
285 * @c:  v9fs client struct
286 *
287 * This initializes the tags structure for each client instance.
288 *
289 */
290
291static int p9_tag_init(struct p9_client *c)
292{
293	int err = 0;
294
295	c->tagpool = p9_idpool_create();
296	if (IS_ERR(c->tagpool)) {
297		err = PTR_ERR(c->tagpool);
298		c->tagpool = NULL;
299		goto error;
300	}
301
302	p9_idpool_get(c->tagpool); /* reserve tag 0 */
303
304	c->max_tag = 0;
305error:
306	return err;
307}
308
309/**
310 * p9_tag_cleanup - cleans up tags structure and reclaims resources
311 * @c:  v9fs client struct
312 *
313 * This frees resources associated with the tags structure
314 *
315 */
316static void p9_tag_cleanup(struct p9_client *c)
317{
318	int row, col;
319
320	/* check to insure all requests are idle */
321	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
322		for (col = 0; col < P9_ROW_MAXTAG; col++) {
323			if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
324				P9_DPRINTK(P9_DEBUG_MUX,
325				  "Attempting to cleanup non-free tag %d,%d\n",
326				  row, col);
327				/* TODO: delay execution of cleanup */
328				return;
329			}
330		}
331	}
332
333	if (c->tagpool)
334		p9_idpool_destroy(c->tagpool);
335
336	/* free requests associated with tags */
337	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
338		for (col = 0; col < P9_ROW_MAXTAG; col++) {
339			kfree(c->reqs[row][col].wq);
340			kfree(c->reqs[row][col].tc);
341			kfree(c->reqs[row][col].rc);
342		}
343		kfree(c->reqs[row]);
344	}
345	c->max_tag = 0;
346}
347
348/**
349 * p9_free_req - free a request and clean-up as necessary
350 * c: client state
351 * r: request to release
352 *
353 */
354
355static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
356{
357	int tag = r->tc->tag;
358	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
359
360	r->status = REQ_STATUS_IDLE;
361	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
362		p9_idpool_put(tag, c->tagpool);
363}
364
365/**
366 * p9_client_cb - call back from transport to client
367 * c: client state
368 * req: request received
369 *
370 */
371void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
372{
373	P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
374	wake_up(req->wq);
375	P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
376}
377EXPORT_SYMBOL(p9_client_cb);
378
379/**
380 * p9_parse_header - parse header arguments out of a packet
381 * @pdu: packet to parse
382 * @size: size of packet
383 * @type: type of request
384 * @tag: tag of packet
385 * @rewind: set if we need to rewind offset afterwards
386 */
387
388int
389p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
390								int rewind)
391{
392	int8_t r_type;
393	int16_t r_tag;
394	int32_t r_size;
395	int offset = pdu->offset;
396	int err;
397
398	pdu->offset = 0;
399	if (pdu->size == 0)
400		pdu->size = 7;
401
402	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
403	if (err)
404		goto rewind_and_exit;
405
406	pdu->size = r_size;
407	pdu->id = r_type;
408	pdu->tag = r_tag;
409
410	P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
411							pdu->id, pdu->tag);
412
413	if (type)
414		*type = r_type;
415	if (tag)
416		*tag = r_tag;
417	if (size)
418		*size = r_size;
419
420
421rewind_and_exit:
422	if (rewind)
423		pdu->offset = offset;
424	return err;
425}
426EXPORT_SYMBOL(p9_parse_header);
427
428/**
429 * p9_check_errors - check 9p packet for error return and process it
430 * @c: current client instance
431 * @req: request to parse and check for error conditions
432 *
433 * returns error code if one is discovered, otherwise returns 0
434 *
435 * this will have to be more complicated if we have multiple
436 * error packet types
437 */
438
439static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
440{
441	int8_t type;
442	int err;
443
444	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
445	if (err) {
446		P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
447		return err;
448	}
449
450	if (type == P9_RERROR) {
451		int ecode;
452		char *ename;
453
454		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
455							&ename, &ecode);
456		if (err) {
457			P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
458									err);
459			return err;
460		}
461
462		if (p9_is_proto_dotu(c))
463			err = -ecode;
464
465		if (!err || !IS_ERR_VALUE(err))
466			err = p9_errstr2errno(ename, strlen(ename));
467
468		P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
469
470		kfree(ename);
471	} else
472		err = 0;
473
474	return err;
475}
476
477/**
478 * p9_client_flush - flush (cancel) a request
479 * @c: client state
480 * @oldreq: request to cancel
481 *
482 * This sents a flush for a particular requests and links
483 * the flush request to the original request.  The current
484 * code only supports a single flush request although the protocol
485 * allows for multiple flush requests to be sent for a single request.
486 *
487 */
488
489static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
490{
491	struct p9_req_t *req;
492	int16_t oldtag;
493	int err;
494
495	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
496	if (err)
497		return err;
498
499	P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
500
501	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
502	if (IS_ERR(req))
503		return PTR_ERR(req);
504
505
506	/* if we haven't received a response for oldreq,
507	   remove it from the list. */
508	spin_lock(&c->lock);
509	if (oldreq->status == REQ_STATUS_FLSH)
510		list_del(&oldreq->req_list);
511	spin_unlock(&c->lock);
512
513	p9_free_req(c, req);
514	return 0;
515}
516
517/**
518 * p9_client_rpc - issue a request and wait for a response
519 * @c: client session
520 * @type: type of request
521 * @fmt: protocol format string (see protocol.c)
522 *
523 * Returns request structure (which client must free using p9_free_req)
524 */
525
526static struct p9_req_t *
527p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
528{
529	va_list ap;
530	int tag, err;
531	struct p9_req_t *req;
532	unsigned long flags;
533	int sigpending;
534
535	P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
536
537	if (c->status != Connected)
538		return ERR_PTR(-EIO);
539
540	if (signal_pending(current)) {
541		sigpending = 1;
542		clear_thread_flag(TIF_SIGPENDING);
543	} else
544		sigpending = 0;
545
546	tag = P9_NOTAG;
547	if (type != P9_TVERSION) {
548		tag = p9_idpool_get(c->tagpool);
549		if (tag < 0)
550			return ERR_PTR(-ENOMEM);
551	}
552
553	req = p9_tag_alloc(c, tag);
554	if (IS_ERR(req))
555		return req;
556
557	/* marshall the data */
558	p9pdu_prepare(req->tc, tag, type);
559	va_start(ap, fmt);
560	err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
561	va_end(ap);
562	p9pdu_finalize(req->tc);
563
564	err = c->trans_mod->request(c, req);
565	if (err < 0) {
566		c->status = Disconnected;
567		goto reterr;
568	}
569
570	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
571	err = wait_event_interruptible(*req->wq,
572						req->status >= REQ_STATUS_RCVD);
573	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
574						req->wq, tag, err);
575
576	if (req->status == REQ_STATUS_ERROR) {
577		P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
578		err = req->t_err;
579	}
580
581	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
582		P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
583		sigpending = 1;
584		clear_thread_flag(TIF_SIGPENDING);
585
586		if (c->trans_mod->cancel(c, req))
587			p9_client_flush(c, req);
588
589		/* if we received the response anyway, don't signal error */
590		if (req->status == REQ_STATUS_RCVD)
591			err = 0;
592	}
593
594	if (sigpending) {
595		spin_lock_irqsave(&current->sighand->siglock, flags);
596		recalc_sigpending();
597		spin_unlock_irqrestore(&current->sighand->siglock, flags);
598	}
599
600	if (err < 0)
601		goto reterr;
602
603	err = p9_check_errors(c, req);
604	if (!err) {
605		P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
606		return req;
607	}
608
609reterr:
610	P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
611									err);
612	p9_free_req(c, req);
613	return ERR_PTR(err);
614}
615
616static struct p9_fid *p9_fid_create(struct p9_client *clnt)
617{
618	int ret;
619	struct p9_fid *fid;
620	unsigned long flags;
621
622	P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
623	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
624	if (!fid)
625		return ERR_PTR(-ENOMEM);
626
627	ret = p9_idpool_get(clnt->fidpool);
628	if (ret < 0) {
629		ret = -ENOSPC;
630		goto error;
631	}
632	fid->fid = ret;
633
634	memset(&fid->qid, 0, sizeof(struct p9_qid));
635	fid->mode = -1;
636	fid->uid = current_fsuid();
637	fid->clnt = clnt;
638	fid->rdir = NULL;
639	spin_lock_irqsave(&clnt->lock, flags);
640	list_add(&fid->flist, &clnt->fidlist);
641	spin_unlock_irqrestore(&clnt->lock, flags);
642
643	return fid;
644
645error:
646	kfree(fid);
647	return ERR_PTR(ret);
648}
649
650static void p9_fid_destroy(struct p9_fid *fid)
651{
652	struct p9_client *clnt;
653	unsigned long flags;
654
655	P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
656	clnt = fid->clnt;
657	p9_idpool_put(fid->fid, clnt->fidpool);
658	spin_lock_irqsave(&clnt->lock, flags);
659	list_del(&fid->flist);
660	spin_unlock_irqrestore(&clnt->lock, flags);
661	kfree(fid->rdir);
662	kfree(fid);
663}
664
665int p9_client_version(struct p9_client *c)
666{
667	int err = 0;
668	struct p9_req_t *req;
669	char *version;
670	int msize;
671
672	P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
673						c->msize, c->proto_version);
674
675	switch (c->proto_version) {
676	case p9_proto_2000L:
677		req = p9_client_rpc(c, P9_TVERSION, "ds",
678					c->msize, "9P2000.L");
679		break;
680	case p9_proto_2000u:
681		req = p9_client_rpc(c, P9_TVERSION, "ds",
682					c->msize, "9P2000.u");
683		break;
684	case p9_proto_legacy:
685		req = p9_client_rpc(c, P9_TVERSION, "ds",
686					c->msize, "9P2000");
687		break;
688	default:
689		return -EINVAL;
690		break;
691	}
692
693	if (IS_ERR(req))
694		return PTR_ERR(req);
695
696	err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
697	if (err) {
698		P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
699		p9pdu_dump(1, req->rc);
700		goto error;
701	}
702
703	P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
704	if (!strncmp(version, "9P2000.L", 8))
705		c->proto_version = p9_proto_2000L;
706	else if (!strncmp(version, "9P2000.u", 8))
707		c->proto_version = p9_proto_2000u;
708	else if (!strncmp(version, "9P2000", 6))
709		c->proto_version = p9_proto_legacy;
710	else {
711		err = -EREMOTEIO;
712		goto error;
713	}
714
715	if (msize < c->msize)
716		c->msize = msize;
717
718error:
719	kfree(version);
720	p9_free_req(c, req);
721
722	return err;
723}
724EXPORT_SYMBOL(p9_client_version);
725
726struct p9_client *p9_client_create(const char *dev_name, char *options)
727{
728	int err;
729	struct p9_client *clnt;
730
731	err = 0;
732	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
733	if (!clnt)
734		return ERR_PTR(-ENOMEM);
735
736	clnt->trans_mod = NULL;
737	clnt->trans = NULL;
738	spin_lock_init(&clnt->lock);
739	INIT_LIST_HEAD(&clnt->fidlist);
740
741	p9_tag_init(clnt);
742
743	err = parse_opts(options, clnt);
744	if (err < 0)
745		goto free_client;
746
747	if (!clnt->trans_mod)
748		clnt->trans_mod = v9fs_get_default_trans();
749
750	if (clnt->trans_mod == NULL) {
751		err = -EPROTONOSUPPORT;
752		P9_DPRINTK(P9_DEBUG_ERROR,
753				"No transport defined or default transport\n");
754		goto free_client;
755	}
756
757	clnt->fidpool = p9_idpool_create();
758	if (IS_ERR(clnt->fidpool)) {
759		err = PTR_ERR(clnt->fidpool);
760		clnt->fidpool = NULL;
761		goto put_trans;
762	}
763
764	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
765		clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
766
767	err = clnt->trans_mod->create(clnt, dev_name, options);
768	if (err)
769		goto destroy_fidpool;
770
771	if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
772		clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
773
774	err = p9_client_version(clnt);
775	if (err)
776		goto close_trans;
777
778	return clnt;
779
780close_trans:
781	clnt->trans_mod->close(clnt);
782destroy_fidpool:
783	p9_idpool_destroy(clnt->fidpool);
784put_trans:
785	v9fs_put_trans(clnt->trans_mod);
786free_client:
787	kfree(clnt);
788	return ERR_PTR(err);
789}
790EXPORT_SYMBOL(p9_client_create);
791
792void p9_client_destroy(struct p9_client *clnt)
793{
794	struct p9_fid *fid, *fidptr;
795
796	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
797
798	if (clnt->trans_mod)
799		clnt->trans_mod->close(clnt);
800
801	v9fs_put_trans(clnt->trans_mod);
802
803	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
804		p9_fid_destroy(fid);
805
806	if (clnt->fidpool)
807		p9_idpool_destroy(clnt->fidpool);
808
809	p9_tag_cleanup(clnt);
810
811	kfree(clnt);
812}
813EXPORT_SYMBOL(p9_client_destroy);
814
815void p9_client_disconnect(struct p9_client *clnt)
816{
817	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
818	clnt->status = Disconnected;
819}
820EXPORT_SYMBOL(p9_client_disconnect);
821
822struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
823	char *uname, u32 n_uname, char *aname)
824{
825	int err;
826	struct p9_req_t *req;
827	struct p9_fid *fid;
828	struct p9_qid qid;
829
830	P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
831					afid ? afid->fid : -1, uname, aname);
832	err = 0;
833
834	fid = p9_fid_create(clnt);
835	if (IS_ERR(fid)) {
836		err = PTR_ERR(fid);
837		fid = NULL;
838		goto error;
839	}
840
841	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
842			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
843	if (IS_ERR(req)) {
844		err = PTR_ERR(req);
845		goto error;
846	}
847
848	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
849	if (err) {
850		p9pdu_dump(1, req->rc);
851		p9_free_req(clnt, req);
852		goto error;
853	}
854
855	P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
856					qid.type,
857					(unsigned long long)qid.path,
858					qid.version);
859
860	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
861
862	p9_free_req(clnt, req);
863	return fid;
864
865error:
866	if (fid)
867		p9_fid_destroy(fid);
868	return ERR_PTR(err);
869}
870EXPORT_SYMBOL(p9_client_attach);
871
872struct p9_fid *
873p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
874{
875	int err;
876	struct p9_req_t *req;
877	struct p9_qid qid;
878	struct p9_fid *afid;
879
880	P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
881	err = 0;
882
883	afid = p9_fid_create(clnt);
884	if (IS_ERR(afid)) {
885		err = PTR_ERR(afid);
886		afid = NULL;
887		goto error;
888	}
889
890	req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
891			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
892	if (IS_ERR(req)) {
893		err = PTR_ERR(req);
894		goto error;
895	}
896
897	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
898	if (err) {
899		p9pdu_dump(1, req->rc);
900		p9_free_req(clnt, req);
901		goto error;
902	}
903
904	P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
905					qid.type,
906					(unsigned long long)qid.path,
907					qid.version);
908
909	memmove(&afid->qid, &qid, sizeof(struct p9_qid));
910	p9_free_req(clnt, req);
911	return afid;
912
913error:
914	if (afid)
915		p9_fid_destroy(afid);
916	return ERR_PTR(err);
917}
918EXPORT_SYMBOL(p9_client_auth);
919
920struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
921	int clone)
922{
923	int err;
924	struct p9_client *clnt;
925	struct p9_fid *fid;
926	struct p9_qid *wqids;
927	struct p9_req_t *req;
928	int16_t nwqids, count;
929
930	err = 0;
931	clnt = oldfid->clnt;
932	if (clone) {
933		fid = p9_fid_create(clnt);
934		if (IS_ERR(fid)) {
935			err = PTR_ERR(fid);
936			fid = NULL;
937			goto error;
938		}
939
940		fid->uid = oldfid->uid;
941	} else
942		fid = oldfid;
943
944
945	P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
946		oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
947
948	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
949								nwname, wnames);
950	if (IS_ERR(req)) {
951		err = PTR_ERR(req);
952		goto error;
953	}
954
955	err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
956	if (err) {
957		p9pdu_dump(1, req->rc);
958		p9_free_req(clnt, req);
959		goto clunk_fid;
960	}
961	p9_free_req(clnt, req);
962
963	P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
964
965	if (nwqids != nwname) {
966		err = -ENOENT;
967		goto clunk_fid;
968	}
969
970	for (count = 0; count < nwqids; count++)
971		P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
972			count, wqids[count].type,
973			(unsigned long long)wqids[count].path,
974			wqids[count].version);
975
976	if (nwname)
977		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
978	else
979		fid->qid = oldfid->qid;
980
981	return fid;
982
983clunk_fid:
984	p9_client_clunk(fid);
985	fid = NULL;
986
987error:
988	if (fid && (fid != oldfid))
989		p9_fid_destroy(fid);
990
991	return ERR_PTR(err);
992}
993EXPORT_SYMBOL(p9_client_walk);
994
995int p9_client_open(struct p9_fid *fid, int mode)
996{
997	int err;
998	struct p9_client *clnt;
999	struct p9_req_t *req;
1000	struct p9_qid qid;
1001	int iounit;
1002
1003	P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
1004	err = 0;
1005	clnt = fid->clnt;
1006
1007	if (fid->mode != -1)
1008		return -EINVAL;
1009
1010	req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1011	if (IS_ERR(req)) {
1012		err = PTR_ERR(req);
1013		goto error;
1014	}
1015
1016	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1017	if (err) {
1018		p9pdu_dump(1, req->rc);
1019		goto free_and_error;
1020	}
1021
1022	P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
1023				qid.type,
1024				(unsigned long long)qid.path,
1025				qid.version, iounit);
1026
1027	fid->mode = mode;
1028	fid->iounit = iounit;
1029
1030free_and_error:
1031	p9_free_req(clnt, req);
1032error:
1033	return err;
1034}
1035EXPORT_SYMBOL(p9_client_open);
1036
1037int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1038		     char *extension)
1039{
1040	int err;
1041	struct p9_client *clnt;
1042	struct p9_req_t *req;
1043	struct p9_qid qid;
1044	int iounit;
1045
1046	P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1047						fid->fid, name, perm, mode);
1048	err = 0;
1049	clnt = fid->clnt;
1050
1051	if (fid->mode != -1)
1052		return -EINVAL;
1053
1054	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1055				mode, extension);
1056	if (IS_ERR(req)) {
1057		err = PTR_ERR(req);
1058		goto error;
1059	}
1060
1061	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1062	if (err) {
1063		p9pdu_dump(1, req->rc);
1064		goto free_and_error;
1065	}
1066
1067	P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1068				qid.type,
1069				(unsigned long long)qid.path,
1070				qid.version, iounit);
1071
1072	fid->mode = mode;
1073	fid->iounit = iounit;
1074
1075free_and_error:
1076	p9_free_req(clnt, req);
1077error:
1078	return err;
1079}
1080EXPORT_SYMBOL(p9_client_fcreate);
1081
1082int p9_client_clunk(struct p9_fid *fid)
1083{
1084	int err;
1085	struct p9_client *clnt;
1086	struct p9_req_t *req;
1087
1088	P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1089	err = 0;
1090	clnt = fid->clnt;
1091
1092	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1093	if (IS_ERR(req)) {
1094		err = PTR_ERR(req);
1095		goto error;
1096	}
1097
1098	P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1099
1100	p9_free_req(clnt, req);
1101	p9_fid_destroy(fid);
1102
1103error:
1104	return err;
1105}
1106EXPORT_SYMBOL(p9_client_clunk);
1107
1108int p9_client_remove(struct p9_fid *fid)
1109{
1110	int err;
1111	struct p9_client *clnt;
1112	struct p9_req_t *req;
1113
1114	P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1115	err = 0;
1116	clnt = fid->clnt;
1117
1118	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1119	if (IS_ERR(req)) {
1120		err = PTR_ERR(req);
1121		goto error;
1122	}
1123
1124	P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1125
1126	p9_free_req(clnt, req);
1127	p9_fid_destroy(fid);
1128
1129error:
1130	return err;
1131}
1132EXPORT_SYMBOL(p9_client_remove);
1133
1134int
1135p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1136								u32 count)
1137{
1138	int err, rsize, total;
1139	struct p9_client *clnt;
1140	struct p9_req_t *req;
1141	char *dataptr;
1142
1143	P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1144					(long long unsigned) offset, count);
1145	err = 0;
1146	clnt = fid->clnt;
1147	total = 0;
1148
1149	rsize = fid->iounit;
1150	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1151		rsize = clnt->msize - P9_IOHDRSZ;
1152
1153	if (count < rsize)
1154		rsize = count;
1155
1156	req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1157	if (IS_ERR(req)) {
1158		err = PTR_ERR(req);
1159		goto error;
1160	}
1161
1162	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1163	if (err) {
1164		p9pdu_dump(1, req->rc);
1165		goto free_and_error;
1166	}
1167
1168	P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1169
1170	if (data) {
1171		memmove(data, dataptr, count);
1172	}
1173
1174	if (udata) {
1175		err = copy_to_user(udata, dataptr, count);
1176		if (err) {
1177			err = -EFAULT;
1178			goto free_and_error;
1179		}
1180	}
1181
1182	p9_free_req(clnt, req);
1183	return count;
1184
1185free_and_error:
1186	p9_free_req(clnt, req);
1187error:
1188	return err;
1189}
1190EXPORT_SYMBOL(p9_client_read);
1191
1192int
1193p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1194							u64 offset, u32 count)
1195{
1196	int err, rsize, total;
1197	struct p9_client *clnt;
1198	struct p9_req_t *req;
1199
1200	P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1201				fid->fid, (long long unsigned) offset, count);
1202	err = 0;
1203	clnt = fid->clnt;
1204	total = 0;
1205
1206	rsize = fid->iounit;
1207	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1208		rsize = clnt->msize - P9_IOHDRSZ;
1209
1210	if (count < rsize)
1211		rsize = count;
1212	if (data)
1213		req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1214								rsize, data);
1215	else
1216		req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1217								rsize, udata);
1218	if (IS_ERR(req)) {
1219		err = PTR_ERR(req);
1220		goto error;
1221	}
1222
1223	err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1224	if (err) {
1225		p9pdu_dump(1, req->rc);
1226		goto free_and_error;
1227	}
1228
1229	P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1230
1231	p9_free_req(clnt, req);
1232	return count;
1233
1234free_and_error:
1235	p9_free_req(clnt, req);
1236error:
1237	return err;
1238}
1239EXPORT_SYMBOL(p9_client_write);
1240
1241struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1242{
1243	int err;
1244	struct p9_client *clnt;
1245	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1246	struct p9_req_t *req;
1247	u16 ignored;
1248
1249	P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1250
1251	if (!ret)
1252		return ERR_PTR(-ENOMEM);
1253
1254	err = 0;
1255	clnt = fid->clnt;
1256
1257	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1258	if (IS_ERR(req)) {
1259		err = PTR_ERR(req);
1260		goto error;
1261	}
1262
1263	err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1264	if (err) {
1265		p9pdu_dump(1, req->rc);
1266		p9_free_req(clnt, req);
1267		goto error;
1268	}
1269
1270	P9_DPRINTK(P9_DEBUG_9P,
1271		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1272		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1273		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1274		"<<<    uid=%d gid=%d n_muid=%d\n",
1275		ret->size, ret->type, ret->dev, ret->qid.type,
1276		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1277		ret->atime, ret->mtime, (unsigned long long)ret->length,
1278		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1279		ret->n_uid, ret->n_gid, ret->n_muid);
1280
1281	p9_free_req(clnt, req);
1282	return ret;
1283
1284error:
1285	kfree(ret);
1286	return ERR_PTR(err);
1287}
1288EXPORT_SYMBOL(p9_client_stat);
1289
1290static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1291{
1292	int ret;
1293
1294	/* NOTE: size shouldn't include its own length */
1295	/* size[2] type[2] dev[4] qid[13] */
1296	/* mode[4] atime[4] mtime[4] length[8]*/
1297	/* name[s] uid[s] gid[s] muid[s] */
1298	ret = 2+4+13+4+4+4+8+2+2+2+2;
1299
1300	if (wst->name)
1301		ret += strlen(wst->name);
1302	if (wst->uid)
1303		ret += strlen(wst->uid);
1304	if (wst->gid)
1305		ret += strlen(wst->gid);
1306	if (wst->muid)
1307		ret += strlen(wst->muid);
1308
1309	if (proto_version == p9_proto_2000u) {
1310		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1311		if (wst->extension)
1312			ret += strlen(wst->extension);
1313	}
1314
1315	return ret;
1316}
1317
1318int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1319{
1320	int err;
1321	struct p9_req_t *req;
1322	struct p9_client *clnt;
1323
1324	err = 0;
1325	clnt = fid->clnt;
1326	wst->size = p9_client_statsize(wst, clnt->proto_version);
1327	P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1328	P9_DPRINTK(P9_DEBUG_9P,
1329		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1330		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1331		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1332		"     uid=%d gid=%d n_muid=%d\n",
1333		wst->size, wst->type, wst->dev, wst->qid.type,
1334		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1335		wst->atime, wst->mtime, (unsigned long long)wst->length,
1336		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1337		wst->n_uid, wst->n_gid, wst->n_muid);
1338
1339	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1340	if (IS_ERR(req)) {
1341		err = PTR_ERR(req);
1342		goto error;
1343	}
1344
1345	P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1346
1347	p9_free_req(clnt, req);
1348error:
1349	return err;
1350}
1351EXPORT_SYMBOL(p9_client_wstat);
1352