client.c revision 9f3e9bbe62b0bdbbaa7c689a68a22a7d3c1670f0
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/sched.h>
33#include <linux/uaccess.h>
34#include <net/9p/9p.h>
35#include <linux/parser.h>
36#include <net/9p/client.h>
37#include <net/9p/transport.h>
38#include "protocol.h"
39
40/*
41  * Client Option Parsing (code inspired by NFS code)
42  *  - a little lazy - parse all client options
43  */
44
45enum {
46	Opt_msize,
47	Opt_trans,
48	Opt_legacy,
49	Opt_err,
50};
51
52static const match_table_t tokens = {
53	{Opt_msize, "msize=%u"},
54	{Opt_legacy, "noextend"},
55	{Opt_trans, "trans=%s"},
56	{Opt_err, NULL},
57};
58
59static struct p9_req_t *
60p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
61
62/**
63 * v9fs_parse_options - parse mount options into session structure
64 * @options: options string passed from mount
65 * @v9ses: existing v9fs session information
66 *
67 * Return 0 upon success, -ERRNO upon failure
68 */
69
70static int parse_opts(char *opts, struct p9_client *clnt)
71{
72	char *options;
73	char *p;
74	substring_t args[MAX_OPT_ARGS];
75	int option;
76	int ret = 0;
77
78	clnt->dotu = 1;
79	clnt->msize = 8192;
80
81	if (!opts)
82		return 0;
83
84	options = kstrdup(opts, GFP_KERNEL);
85	if (!options) {
86		P9_DPRINTK(P9_DEBUG_ERROR,
87				"failed to allocate copy of option string\n");
88		return -ENOMEM;
89	}
90
91	while ((p = strsep(&options, ",")) != NULL) {
92		int token;
93		if (!*p)
94			continue;
95		token = match_token(p, tokens, args);
96		if (token < Opt_trans) {
97			int r = match_int(&args[0], &option);
98			if (r < 0) {
99				P9_DPRINTK(P9_DEBUG_ERROR,
100					"integer field, but no integer?\n");
101				ret = r;
102				continue;
103			}
104		}
105		switch (token) {
106		case Opt_msize:
107			clnt->msize = option;
108			break;
109		case Opt_trans:
110			clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
111			break;
112		case Opt_legacy:
113			clnt->dotu = 0;
114			break;
115		default:
116			continue;
117		}
118	}
119
120	if (!clnt->trans_mod)
121		clnt->trans_mod = v9fs_get_default_trans();
122
123	kfree(options);
124	return ret;
125}
126
127/**
128 * p9_tag_alloc - lookup/allocate a request by tag
129 * @c: client session to lookup tag within
130 * @tag: numeric id for transaction
131 *
132 * this is a simple array lookup, but will grow the
133 * request_slots as necessary to accomodate transaction
134 * ids which did not previously have a slot.
135 *
136 * this code relies on the client spinlock to manage locks, its
137 * possible we should switch to something else, but I'd rather
138 * stick with something low-overhead for the common case.
139 *
140 */
141
142static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
143{
144	unsigned long flags;
145	int row, col;
146	struct p9_req_t *req;
147
148	/* This looks up the original request by tag so we know which
149	 * buffer to read the data into */
150	tag++;
151
152	if (tag >= c->max_tag) {
153		spin_lock_irqsave(&c->lock, flags);
154		/* check again since original check was outside of lock */
155		while (tag >= c->max_tag) {
156			row = (tag / P9_ROW_MAXTAG);
157			c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
158					sizeof(struct p9_req_t), GFP_ATOMIC);
159
160			if (!c->reqs[row]) {
161				printk(KERN_ERR "Couldn't grow tag array\n");
162				spin_unlock_irqrestore(&c->lock, flags);
163				return ERR_PTR(-ENOMEM);
164			}
165			for (col = 0; col < P9_ROW_MAXTAG; col++) {
166				c->reqs[row][col].status = REQ_STATUS_IDLE;
167				c->reqs[row][col].tc = NULL;
168			}
169			c->max_tag += P9_ROW_MAXTAG;
170		}
171		spin_unlock_irqrestore(&c->lock, flags);
172	}
173	row = tag / P9_ROW_MAXTAG;
174	col = tag % P9_ROW_MAXTAG;
175
176	req = &c->reqs[row][col];
177	if (!req->tc) {
178		req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
179		if (!req->wq) {
180			printk(KERN_ERR "Couldn't grow tag array\n");
181			return ERR_PTR(-ENOMEM);
182		}
183		init_waitqueue_head(req->wq);
184		req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
185								GFP_KERNEL);
186		req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
187								GFP_KERNEL);
188		if ((!req->tc) || (!req->rc)) {
189			printk(KERN_ERR "Couldn't grow tag array\n");
190			kfree(req->tc);
191			kfree(req->rc);
192			kfree(req->wq);
193			req->tc = req->rc = NULL;
194			req->wq = NULL;
195			return ERR_PTR(-ENOMEM);
196		}
197		req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
198		req->tc->capacity = c->msize;
199		req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
200		req->rc->capacity = c->msize;
201	}
202
203	p9pdu_reset(req->tc);
204	p9pdu_reset(req->rc);
205
206	req->flush_tag = 0;
207	req->tc->tag = tag-1;
208	req->status = REQ_STATUS_ALLOC;
209
210	return &c->reqs[row][col];
211}
212
213/**
214 * p9_tag_lookup - lookup a request by tag
215 * @c: client session to lookup tag within
216 * @tag: numeric id for transaction
217 *
218 */
219
220struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
221{
222	int row, col;
223
224	/* This looks up the original request by tag so we know which
225	 * buffer to read the data into */
226	tag++;
227
228	BUG_ON(tag >= c->max_tag);
229
230	row = tag / P9_ROW_MAXTAG;
231	col = tag % P9_ROW_MAXTAG;
232
233	return &c->reqs[row][col];
234}
235EXPORT_SYMBOL(p9_tag_lookup);
236
237/**
238 * p9_tag_init - setup tags structure and contents
239 * @tags: tags structure from the client struct
240 *
241 * This initializes the tags structure for each client instance.
242 *
243 */
244
245static int p9_tag_init(struct p9_client *c)
246{
247	int err = 0;
248
249	c->tagpool = p9_idpool_create();
250	if (IS_ERR(c->tagpool)) {
251		err = PTR_ERR(c->tagpool);
252		c->tagpool = NULL;
253		goto error;
254	}
255
256	p9_idpool_get(c->tagpool); /* reserve tag 0 */
257
258	c->max_tag = 0;
259error:
260	return err;
261}
262
263/**
264 * p9_tag_cleanup - cleans up tags structure and reclaims resources
265 * @tags: tags structure from the client struct
266 *
267 * This frees resources associated with the tags structure
268 *
269 */
270static void p9_tag_cleanup(struct p9_client *c)
271{
272	int row, col;
273
274	/* check to insure all requests are idle */
275	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
276		for (col = 0; col < P9_ROW_MAXTAG; col++) {
277			if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
278				P9_DPRINTK(P9_DEBUG_MUX,
279				  "Attempting to cleanup non-free tag %d,%d\n",
280				  row, col);
281				/* TODO: delay execution of cleanup */
282				return;
283			}
284		}
285	}
286
287	if (c->tagpool)
288		p9_idpool_destroy(c->tagpool);
289
290	/* free requests associated with tags */
291	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
292		for (col = 0; col < P9_ROW_MAXTAG; col++) {
293			kfree(c->reqs[row][col].wq);
294			kfree(c->reqs[row][col].tc);
295			kfree(c->reqs[row][col].rc);
296		}
297		kfree(c->reqs[row]);
298	}
299	c->max_tag = 0;
300}
301
302/**
303 * p9_free_req - free a request and clean-up as necessary
304 * c: client state
305 * r: request to release
306 *
307 */
308
309static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
310{
311	int tag = r->tc->tag;
312	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
313
314	r->status = REQ_STATUS_IDLE;
315	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
316		p9_idpool_put(tag, c->tagpool);
317}
318
319/**
320 * p9_client_cb - call back from transport to client
321 * c: client state
322 * req: request received
323 *
324 */
325void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
326{
327	struct p9_req_t *other_req;
328	unsigned long flags;
329
330	P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
331
332	if (req->status == REQ_STATUS_ERROR)
333		wake_up(req->wq);
334
335	if (req->flush_tag) { 			/* flush receive path */
336		P9_DPRINTK(P9_DEBUG_9P, "<<< RFLUSH %d\n", req->tc->tag);
337		spin_lock_irqsave(&c->lock, flags);
338		other_req = p9_tag_lookup(c, req->flush_tag);
339		if (other_req->status != REQ_STATUS_FLSH) /* stale flush */
340			spin_unlock_irqrestore(&c->lock, flags);
341		else {
342			other_req->status = REQ_STATUS_FLSHD;
343			spin_unlock_irqrestore(&c->lock, flags);
344			wake_up(other_req->wq);
345		}
346		p9_free_req(c, req);
347	} else { 				/* normal receive path */
348		P9_DPRINTK(P9_DEBUG_MUX, "normal: tag %d\n", req->tc->tag);
349		spin_lock_irqsave(&c->lock, flags);
350		if (req->status != REQ_STATUS_FLSHD)
351			req->status = REQ_STATUS_RCVD;
352		spin_unlock_irqrestore(&c->lock, flags);
353		wake_up(req->wq);
354		P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
355	}
356}
357EXPORT_SYMBOL(p9_client_cb);
358
359/**
360 * p9_parse_header - parse header arguments out of a packet
361 * @pdu: packet to parse
362 * @size: size of packet
363 * @type: type of request
364 * @tag: tag of packet
365 * @rewind: set if we need to rewind offset afterwards
366 */
367
368int
369p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
370								int rewind)
371{
372	int8_t r_type;
373	int16_t r_tag;
374	int32_t r_size;
375	int offset = pdu->offset;
376	int err;
377
378	pdu->offset = 0;
379	if (pdu->size == 0)
380		pdu->size = 7;
381
382	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
383	if (err)
384		goto rewind_and_exit;
385
386	pdu->size = r_size;
387	pdu->id = r_type;
388	pdu->tag = r_tag;
389
390	P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
391							pdu->id, pdu->tag);
392
393	if (type)
394		*type = r_type;
395	if (tag)
396		*tag = r_tag;
397	if (size)
398		*size = r_size;
399
400
401rewind_and_exit:
402	if (rewind)
403		pdu->offset = offset;
404	return err;
405}
406EXPORT_SYMBOL(p9_parse_header);
407
408/**
409 * p9_check_errors - check 9p packet for error return and process it
410 * @c: current client instance
411 * @req: request to parse and check for error conditions
412 *
413 * returns error code if one is discovered, otherwise returns 0
414 *
415 * this will have to be more complicated if we have multiple
416 * error packet types
417 */
418
419static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
420{
421	int8_t type;
422	int err;
423
424	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
425	if (err) {
426		P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
427		return err;
428	}
429
430	if (type == P9_RERROR) {
431		int ecode;
432		char *ename;
433
434		err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
435		if (err) {
436			P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
437									err);
438			return err;
439		}
440
441		if (c->dotu)
442			err = -ecode;
443
444		if (!err) {
445			err = p9_errstr2errno(ename, strlen(ename));
446
447			/* string match failed */
448			if (!err)
449				err = -ESERVERFAULT;
450		}
451
452		P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
453
454		kfree(ename);
455	} else
456		err = 0;
457
458	return err;
459}
460
461/**
462 * p9_client_flush - flush (cancel) a request
463 * c: client state
464 * req: request to cancel
465 *
466 * This sents a flush for a particular requests and links
467 * the flush request to the original request.  The current
468 * code only supports a single flush request although the protocol
469 * allows for multiple flush requests to be sent for a single request.
470 *
471 */
472
473static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
474{
475	struct p9_req_t *req;
476	int16_t oldtag;
477	int err;
478
479	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
480	if (err)
481		return err;
482
483	P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
484
485	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
486	if (IS_ERR(req))
487		return PTR_ERR(req);
488
489	req->flush_tag = oldtag;
490
491	/* we don't free anything here because RPC isn't complete */
492	return 0;
493}
494
495/**
496 * p9_client_rpc - issue a request and wait for a response
497 * @c: client session
498 * @type: type of request
499 * @fmt: protocol format string (see protocol.c)
500 *
501 * Returns request structure (which client must free using p9_free_req)
502 */
503
504static struct p9_req_t *
505p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
506{
507	va_list ap;
508	int tag, err;
509	struct p9_req_t *req;
510	unsigned long flags;
511	int sigpending;
512	int flushed = 0;
513
514	P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
515
516	if (c->status != Connected)
517		return ERR_PTR(-EIO);
518
519	if (signal_pending(current)) {
520		sigpending = 1;
521		clear_thread_flag(TIF_SIGPENDING);
522	} else
523		sigpending = 0;
524
525	tag = P9_NOTAG;
526	if (type != P9_TVERSION) {
527		tag = p9_idpool_get(c->tagpool);
528		if (tag < 0)
529			return ERR_PTR(-ENOMEM);
530	}
531
532	req = p9_tag_alloc(c, tag);
533	if (IS_ERR(req))
534		return req;
535
536	/* marshall the data */
537	p9pdu_prepare(req->tc, tag, type);
538	va_start(ap, fmt);
539	err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
540	va_end(ap);
541	p9pdu_finalize(req->tc);
542
543	err = c->trans_mod->request(c, req);
544	if (err < 0) {
545		c->status = Disconnected;
546		goto reterr;
547	}
548
549	/* if it was a flush we just transmitted, return our tag */
550	if (type == P9_TFLUSH)
551		return req;
552again:
553	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
554	err = wait_event_interruptible(*req->wq,
555						req->status >= REQ_STATUS_RCVD);
556	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d (flushed=%d)\n",
557						req->wq, tag, err, flushed);
558
559	if (req->status == REQ_STATUS_ERROR) {
560		P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
561		err = req->t_err;
562	} else if (err == -ERESTARTSYS && flushed) {
563		P9_DPRINTK(P9_DEBUG_MUX, "flushed - going again\n");
564		goto again;
565	} else if (req->status == REQ_STATUS_FLSHD) {
566		P9_DPRINTK(P9_DEBUG_MUX, "flushed - erestartsys\n");
567		err = -ERESTARTSYS;
568	}
569
570	if ((err == -ERESTARTSYS) && (c->status == Connected) && (!flushed)) {
571		P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
572		spin_lock_irqsave(&c->lock, flags);
573		if (req->status == REQ_STATUS_SENT)
574			req->status = REQ_STATUS_FLSH;
575		spin_unlock_irqrestore(&c->lock, flags);
576		sigpending = 1;
577		flushed = 1;
578		clear_thread_flag(TIF_SIGPENDING);
579
580		if (c->trans_mod->cancel(c, req)) {
581			err = p9_client_flush(c, req);
582			if (err == 0)
583				goto again;
584		}
585	}
586
587	if (sigpending) {
588		spin_lock_irqsave(&current->sighand->siglock, flags);
589		recalc_sigpending();
590		spin_unlock_irqrestore(&current->sighand->siglock, flags);
591	}
592
593	if (err < 0)
594		goto reterr;
595
596	err = p9_check_errors(c, req);
597	if (!err) {
598		P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
599		return req;
600	}
601
602reterr:
603	P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
604									err);
605	p9_free_req(c, req);
606	return ERR_PTR(err);
607}
608
609static struct p9_fid *p9_fid_create(struct p9_client *clnt)
610{
611	int ret;
612	struct p9_fid *fid;
613	unsigned long flags;
614
615	P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
616	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
617	if (!fid)
618		return ERR_PTR(-ENOMEM);
619
620	ret = p9_idpool_get(clnt->fidpool);
621	if (fid->fid < 0) {
622		ret = -ENOSPC;
623		goto error;
624	}
625	fid->fid = ret;
626
627	memset(&fid->qid, 0, sizeof(struct p9_qid));
628	fid->mode = -1;
629	fid->rdir_fpos = 0;
630	fid->uid = current->fsuid;
631	fid->clnt = clnt;
632	fid->aux = NULL;
633
634	spin_lock_irqsave(&clnt->lock, flags);
635	list_add(&fid->flist, &clnt->fidlist);
636	spin_unlock_irqrestore(&clnt->lock, flags);
637
638	return fid;
639
640error:
641	kfree(fid);
642	return ERR_PTR(ret);
643}
644
645static void p9_fid_destroy(struct p9_fid *fid)
646{
647	struct p9_client *clnt;
648	unsigned long flags;
649
650	P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
651	clnt = fid->clnt;
652	p9_idpool_put(fid->fid, clnt->fidpool);
653	spin_lock_irqsave(&clnt->lock, flags);
654	list_del(&fid->flist);
655	spin_unlock_irqrestore(&clnt->lock, flags);
656	kfree(fid);
657}
658
659int p9_client_version(struct p9_client *c)
660{
661	int err = 0;
662	struct p9_req_t *req;
663	char *version;
664	int msize;
665
666	P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
667							c->msize, c->dotu);
668	req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
669				c->dotu ? "9P2000.u" : "9P2000");
670	if (IS_ERR(req))
671		return PTR_ERR(req);
672
673	err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
674	if (err) {
675		P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
676		p9pdu_dump(1, req->rc);
677		goto error;
678	}
679
680	P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
681	if (!memcmp(version, "9P2000.u", 8))
682		c->dotu = 1;
683	else if (!memcmp(version, "9P2000", 6))
684		c->dotu = 0;
685	else {
686		err = -EREMOTEIO;
687		goto error;
688	}
689
690	if (msize < c->msize)
691		c->msize = msize;
692
693error:
694	kfree(version);
695	p9_free_req(c, req);
696
697	return err;
698}
699EXPORT_SYMBOL(p9_client_version);
700
701struct p9_client *p9_client_create(const char *dev_name, char *options)
702{
703	int err;
704	struct p9_client *clnt;
705
706	err = 0;
707	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
708	if (!clnt)
709		return ERR_PTR(-ENOMEM);
710
711	clnt->trans_mod = NULL;
712	clnt->trans = NULL;
713	spin_lock_init(&clnt->lock);
714	INIT_LIST_HEAD(&clnt->fidlist);
715	clnt->fidpool = p9_idpool_create();
716	if (IS_ERR(clnt->fidpool)) {
717		err = PTR_ERR(clnt->fidpool);
718		clnt->fidpool = NULL;
719		goto error;
720	}
721
722	p9_tag_init(clnt);
723
724	err = parse_opts(options, clnt);
725	if (err < 0)
726		goto error;
727
728	if (clnt->trans_mod == NULL) {
729		err = -EPROTONOSUPPORT;
730		P9_DPRINTK(P9_DEBUG_ERROR,
731				"No transport defined or default transport\n");
732		goto error;
733	}
734
735	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
736		clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
737
738	err = clnt->trans_mod->create(clnt, dev_name, options);
739	if (err)
740		goto error;
741
742	if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
743		clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
744
745	err = p9_client_version(clnt);
746	if (err)
747		goto error;
748
749	return clnt;
750
751error:
752	p9_client_destroy(clnt);
753	return ERR_PTR(err);
754}
755EXPORT_SYMBOL(p9_client_create);
756
757void p9_client_destroy(struct p9_client *clnt)
758{
759	struct p9_fid *fid, *fidptr;
760
761	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
762
763	if (clnt->trans_mod)
764		clnt->trans_mod->close(clnt);
765
766	v9fs_put_trans(clnt->trans_mod);
767
768	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
769		p9_fid_destroy(fid);
770
771	if (clnt->fidpool)
772		p9_idpool_destroy(clnt->fidpool);
773
774	p9_tag_cleanup(clnt);
775
776	kfree(clnt);
777}
778EXPORT_SYMBOL(p9_client_destroy);
779
780void p9_client_disconnect(struct p9_client *clnt)
781{
782	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
783	clnt->status = Disconnected;
784}
785EXPORT_SYMBOL(p9_client_disconnect);
786
787struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
788	char *uname, u32 n_uname, char *aname)
789{
790	int err;
791	struct p9_req_t *req;
792	struct p9_fid *fid;
793	struct p9_qid qid;
794
795	P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
796					afid ? afid->fid : -1, uname, aname);
797	err = 0;
798
799	fid = p9_fid_create(clnt);
800	if (IS_ERR(fid)) {
801		err = PTR_ERR(fid);
802		fid = NULL;
803		goto error;
804	}
805
806	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
807			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
808	if (IS_ERR(req)) {
809		err = PTR_ERR(req);
810		goto error;
811	}
812
813	err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
814	if (err) {
815		p9pdu_dump(1, req->rc);
816		p9_free_req(clnt, req);
817		goto error;
818	}
819
820	P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
821					qid.type, qid.path, qid.version);
822
823	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
824
825	p9_free_req(clnt, req);
826	return fid;
827
828error:
829	if (fid)
830		p9_fid_destroy(fid);
831	return ERR_PTR(err);
832}
833EXPORT_SYMBOL(p9_client_attach);
834
835struct p9_fid *
836p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
837{
838	int err;
839	struct p9_req_t *req;
840	struct p9_qid qid;
841	struct p9_fid *afid;
842
843	P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
844	err = 0;
845
846	afid = p9_fid_create(clnt);
847	if (IS_ERR(afid)) {
848		err = PTR_ERR(afid);
849		afid = NULL;
850		goto error;
851	}
852
853	req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
854			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
855	if (IS_ERR(req)) {
856		err = PTR_ERR(req);
857		goto error;
858	}
859
860	err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
861	if (err) {
862		p9pdu_dump(1, req->rc);
863		p9_free_req(clnt, req);
864		goto error;
865	}
866
867	P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
868					qid.type, qid.path, qid.version);
869
870	memmove(&afid->qid, &qid, sizeof(struct p9_qid));
871	p9_free_req(clnt, req);
872	return afid;
873
874error:
875	if (afid)
876		p9_fid_destroy(afid);
877	return ERR_PTR(err);
878}
879EXPORT_SYMBOL(p9_client_auth);
880
881struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
882	int clone)
883{
884	int err;
885	struct p9_client *clnt;
886	struct p9_fid *fid;
887	struct p9_qid *wqids;
888	struct p9_req_t *req;
889	int16_t nwqids, count;
890
891	err = 0;
892	clnt = oldfid->clnt;
893	if (clone) {
894		fid = p9_fid_create(clnt);
895		if (IS_ERR(fid)) {
896			err = PTR_ERR(fid);
897			fid = NULL;
898			goto error;
899		}
900
901		fid->uid = oldfid->uid;
902	} else
903		fid = oldfid;
904
905
906	P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
907		oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
908
909	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
910								nwname, wnames);
911	if (IS_ERR(req)) {
912		err = PTR_ERR(req);
913		goto error;
914	}
915
916	err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
917	if (err) {
918		p9pdu_dump(1, req->rc);
919		p9_free_req(clnt, req);
920		goto clunk_fid;
921	}
922	p9_free_req(clnt, req);
923
924	P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
925
926	if (nwqids != nwname) {
927		err = -ENOENT;
928		goto clunk_fid;
929	}
930
931	for (count = 0; count < nwqids; count++)
932		P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
933			count, wqids[count].type, wqids[count].path,
934			wqids[count].version);
935
936	if (nwname)
937		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
938	else
939		fid->qid = oldfid->qid;
940
941	return fid;
942
943clunk_fid:
944	p9_client_clunk(fid);
945	fid = NULL;
946
947error:
948	if (fid && (fid != oldfid))
949		p9_fid_destroy(fid);
950
951	return ERR_PTR(err);
952}
953EXPORT_SYMBOL(p9_client_walk);
954
955int p9_client_open(struct p9_fid *fid, int mode)
956{
957	int err;
958	struct p9_client *clnt;
959	struct p9_req_t *req;
960	struct p9_qid qid;
961	int iounit;
962
963	P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
964	err = 0;
965	clnt = fid->clnt;
966
967	if (fid->mode != -1)
968		return -EINVAL;
969
970	req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
971	if (IS_ERR(req)) {
972		err = PTR_ERR(req);
973		goto error;
974	}
975
976	err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
977	if (err) {
978		p9pdu_dump(1, req->rc);
979		goto free_and_error;
980	}
981
982	P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
983				qid.type, qid.path, qid.version, iounit);
984
985	fid->mode = mode;
986	fid->iounit = iounit;
987
988free_and_error:
989	p9_free_req(clnt, req);
990error:
991	return err;
992}
993EXPORT_SYMBOL(p9_client_open);
994
995int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
996		     char *extension)
997{
998	int err;
999	struct p9_client *clnt;
1000	struct p9_req_t *req;
1001	struct p9_qid qid;
1002	int iounit;
1003
1004	P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1005						fid->fid, name, perm, mode);
1006	err = 0;
1007	clnt = fid->clnt;
1008
1009	if (fid->mode != -1)
1010		return -EINVAL;
1011
1012	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1013				mode, extension);
1014	if (IS_ERR(req)) {
1015		err = PTR_ERR(req);
1016		goto error;
1017	}
1018
1019	err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
1020	if (err) {
1021		p9pdu_dump(1, req->rc);
1022		goto free_and_error;
1023	}
1024
1025	P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1026				qid.type, qid.path, qid.version, iounit);
1027
1028	fid->mode = mode;
1029	fid->iounit = iounit;
1030
1031free_and_error:
1032	p9_free_req(clnt, req);
1033error:
1034	return err;
1035}
1036EXPORT_SYMBOL(p9_client_fcreate);
1037
1038int p9_client_clunk(struct p9_fid *fid)
1039{
1040	int err;
1041	struct p9_client *clnt;
1042	struct p9_req_t *req;
1043
1044	P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1045	err = 0;
1046	clnt = fid->clnt;
1047
1048	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1049	if (IS_ERR(req)) {
1050		err = PTR_ERR(req);
1051		goto error;
1052	}
1053
1054	P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1055
1056	p9_free_req(clnt, req);
1057	p9_fid_destroy(fid);
1058
1059error:
1060	return err;
1061}
1062EXPORT_SYMBOL(p9_client_clunk);
1063
1064int p9_client_remove(struct p9_fid *fid)
1065{
1066	int err;
1067	struct p9_client *clnt;
1068	struct p9_req_t *req;
1069
1070	P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1071	err = 0;
1072	clnt = fid->clnt;
1073
1074	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1075	if (IS_ERR(req)) {
1076		err = PTR_ERR(req);
1077		goto error;
1078	}
1079
1080	P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1081
1082	p9_free_req(clnt, req);
1083	p9_fid_destroy(fid);
1084
1085error:
1086	return err;
1087}
1088EXPORT_SYMBOL(p9_client_remove);
1089
1090int
1091p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1092								u32 count)
1093{
1094	int err, rsize, total;
1095	struct p9_client *clnt;
1096	struct p9_req_t *req;
1097	char *dataptr;
1098
1099	P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1100					(long long unsigned) offset, count);
1101	err = 0;
1102	clnt = fid->clnt;
1103	total = 0;
1104
1105	rsize = fid->iounit;
1106	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1107		rsize = clnt->msize - P9_IOHDRSZ;
1108
1109	if (count < rsize)
1110		rsize = count;
1111
1112	req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1113	if (IS_ERR(req)) {
1114		err = PTR_ERR(req);
1115		goto error;
1116	}
1117
1118	err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1119	if (err) {
1120		p9pdu_dump(1, req->rc);
1121		goto free_and_error;
1122	}
1123
1124	P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1125
1126	if (data) {
1127		memmove(data, dataptr, count);
1128		data += count;
1129	}
1130
1131	if (udata) {
1132		err = copy_to_user(udata, dataptr, count);
1133		if (err) {
1134			err = -EFAULT;
1135			goto free_and_error;
1136		}
1137	}
1138
1139	p9_free_req(clnt, req);
1140	return count;
1141
1142free_and_error:
1143	p9_free_req(clnt, req);
1144error:
1145	return err;
1146}
1147EXPORT_SYMBOL(p9_client_read);
1148
1149int
1150p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1151							u64 offset, u32 count)
1152{
1153	int err, rsize, total;
1154	struct p9_client *clnt;
1155	struct p9_req_t *req;
1156
1157	P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1158				fid->fid, (long long unsigned) offset, count);
1159	err = 0;
1160	clnt = fid->clnt;
1161	total = 0;
1162
1163	rsize = fid->iounit;
1164	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1165		rsize = clnt->msize - P9_IOHDRSZ;
1166
1167	if (count < rsize)
1168		rsize = count;
1169	if (data)
1170		req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1171								rsize, data);
1172	else
1173		req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1174								rsize, udata);
1175	if (IS_ERR(req)) {
1176		err = PTR_ERR(req);
1177		goto error;
1178	}
1179
1180	err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1181	if (err) {
1182		p9pdu_dump(1, req->rc);
1183		goto free_and_error;
1184	}
1185
1186	P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1187
1188	p9_free_req(clnt, req);
1189	return count;
1190
1191free_and_error:
1192	p9_free_req(clnt, req);
1193error:
1194	return err;
1195}
1196EXPORT_SYMBOL(p9_client_write);
1197
1198struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1199{
1200	int err;
1201	struct p9_client *clnt;
1202	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1203	struct p9_req_t *req;
1204	u16 ignored;
1205
1206	P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1207
1208	if (!ret)
1209		return ERR_PTR(-ENOMEM);
1210
1211	err = 0;
1212	clnt = fid->clnt;
1213
1214	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1215	if (IS_ERR(req)) {
1216		err = PTR_ERR(req);
1217		goto error;
1218	}
1219
1220	err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1221	if (err) {
1222		ret = ERR_PTR(err);
1223		p9pdu_dump(1, req->rc);
1224		goto free_and_error;
1225	}
1226
1227	P9_DPRINTK(P9_DEBUG_9P,
1228		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1229		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1230		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1231		"<<<    uid=%d gid=%d n_muid=%d\n",
1232		ret->size, ret->type, ret->dev, ret->qid.type,
1233		ret->qid.path, ret->qid.version, ret->mode,
1234		ret->atime, ret->mtime, ret->length, ret->name,
1235		ret->uid, ret->gid, ret->muid, ret->extension,
1236		ret->n_uid, ret->n_gid, ret->n_muid);
1237
1238free_and_error:
1239	p9_free_req(clnt, req);
1240error:
1241	return ret;
1242}
1243EXPORT_SYMBOL(p9_client_stat);
1244
1245int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1246{
1247	int err;
1248	struct p9_req_t *req;
1249	struct p9_client *clnt;
1250
1251	P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1252	P9_DPRINTK(P9_DEBUG_9P,
1253		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1254		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1255		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1256		"     uid=%d gid=%d n_muid=%d\n",
1257		wst->size, wst->type, wst->dev, wst->qid.type,
1258		wst->qid.path, wst->qid.version, wst->mode,
1259		wst->atime, wst->mtime, wst->length, wst->name,
1260		wst->uid, wst->gid, wst->muid, wst->extension,
1261		wst->n_uid, wst->n_gid, wst->n_muid);
1262	err = 0;
1263	clnt = fid->clnt;
1264
1265	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, 0, wst);
1266	if (IS_ERR(req)) {
1267		err = PTR_ERR(req);
1268		goto error;
1269	}
1270
1271	P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1272
1273	p9_free_req(clnt, req);
1274error:
1275	return err;
1276}
1277EXPORT_SYMBOL(p9_client_wstat);
1278