xref: /openbmc/linux/net/9p/client.c (revision 78c99ba1)
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 
45 enum {
46 	Opt_msize,
47 	Opt_trans,
48 	Opt_legacy,
49 	Opt_err,
50 };
51 
52 static 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 
59 static struct p9_req_t *
60 p9_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 
70 static 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 
142 static 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->tc->tag = tag-1;
207 	req->status = REQ_STATUS_ALLOC;
208 
209 	return &c->reqs[row][col];
210 }
211 
212 /**
213  * p9_tag_lookup - lookup a request by tag
214  * @c: client session to lookup tag within
215  * @tag: numeric id for transaction
216  *
217  */
218 
219 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
220 {
221 	int row, col;
222 
223 	/* This looks up the original request by tag so we know which
224 	 * buffer to read the data into */
225 	tag++;
226 
227 	BUG_ON(tag >= c->max_tag);
228 
229 	row = tag / P9_ROW_MAXTAG;
230 	col = tag % P9_ROW_MAXTAG;
231 
232 	return &c->reqs[row][col];
233 }
234 EXPORT_SYMBOL(p9_tag_lookup);
235 
236 /**
237  * p9_tag_init - setup tags structure and contents
238  * @tags: tags structure from the client struct
239  *
240  * This initializes the tags structure for each client instance.
241  *
242  */
243 
244 static int p9_tag_init(struct p9_client *c)
245 {
246 	int err = 0;
247 
248 	c->tagpool = p9_idpool_create();
249 	if (IS_ERR(c->tagpool)) {
250 		err = PTR_ERR(c->tagpool);
251 		c->tagpool = NULL;
252 		goto error;
253 	}
254 
255 	p9_idpool_get(c->tagpool); /* reserve tag 0 */
256 
257 	c->max_tag = 0;
258 error:
259 	return err;
260 }
261 
262 /**
263  * p9_tag_cleanup - cleans up tags structure and reclaims resources
264  * @tags: tags structure from the client struct
265  *
266  * This frees resources associated with the tags structure
267  *
268  */
269 static void p9_tag_cleanup(struct p9_client *c)
270 {
271 	int row, col;
272 
273 	/* check to insure all requests are idle */
274 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
275 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
276 			if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
277 				P9_DPRINTK(P9_DEBUG_MUX,
278 				  "Attempting to cleanup non-free tag %d,%d\n",
279 				  row, col);
280 				/* TODO: delay execution of cleanup */
281 				return;
282 			}
283 		}
284 	}
285 
286 	if (c->tagpool)
287 		p9_idpool_destroy(c->tagpool);
288 
289 	/* free requests associated with tags */
290 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
291 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
292 			kfree(c->reqs[row][col].wq);
293 			kfree(c->reqs[row][col].tc);
294 			kfree(c->reqs[row][col].rc);
295 		}
296 		kfree(c->reqs[row]);
297 	}
298 	c->max_tag = 0;
299 }
300 
301 /**
302  * p9_free_req - free a request and clean-up as necessary
303  * c: client state
304  * r: request to release
305  *
306  */
307 
308 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
309 {
310 	int tag = r->tc->tag;
311 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
312 
313 	r->status = REQ_STATUS_IDLE;
314 	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
315 		p9_idpool_put(tag, c->tagpool);
316 }
317 
318 /**
319  * p9_client_cb - call back from transport to client
320  * c: client state
321  * req: request received
322  *
323  */
324 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
325 {
326 	P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
327 	wake_up(req->wq);
328 	P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
329 }
330 EXPORT_SYMBOL(p9_client_cb);
331 
332 /**
333  * p9_parse_header - parse header arguments out of a packet
334  * @pdu: packet to parse
335  * @size: size of packet
336  * @type: type of request
337  * @tag: tag of packet
338  * @rewind: set if we need to rewind offset afterwards
339  */
340 
341 int
342 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
343 								int rewind)
344 {
345 	int8_t r_type;
346 	int16_t r_tag;
347 	int32_t r_size;
348 	int offset = pdu->offset;
349 	int err;
350 
351 	pdu->offset = 0;
352 	if (pdu->size == 0)
353 		pdu->size = 7;
354 
355 	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
356 	if (err)
357 		goto rewind_and_exit;
358 
359 	pdu->size = r_size;
360 	pdu->id = r_type;
361 	pdu->tag = r_tag;
362 
363 	P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
364 							pdu->id, pdu->tag);
365 
366 	if (type)
367 		*type = r_type;
368 	if (tag)
369 		*tag = r_tag;
370 	if (size)
371 		*size = r_size;
372 
373 
374 rewind_and_exit:
375 	if (rewind)
376 		pdu->offset = offset;
377 	return err;
378 }
379 EXPORT_SYMBOL(p9_parse_header);
380 
381 /**
382  * p9_check_errors - check 9p packet for error return and process it
383  * @c: current client instance
384  * @req: request to parse and check for error conditions
385  *
386  * returns error code if one is discovered, otherwise returns 0
387  *
388  * this will have to be more complicated if we have multiple
389  * error packet types
390  */
391 
392 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
393 {
394 	int8_t type;
395 	int err;
396 
397 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
398 	if (err) {
399 		P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
400 		return err;
401 	}
402 
403 	if (type == P9_RERROR) {
404 		int ecode;
405 		char *ename;
406 
407 		err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
408 		if (err) {
409 			P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
410 									err);
411 			return err;
412 		}
413 
414 		if (c->dotu)
415 			err = -ecode;
416 
417 		if (!err) {
418 			err = p9_errstr2errno(ename, strlen(ename));
419 
420 			/* string match failed */
421 			if (!err)
422 				err = -ESERVERFAULT;
423 		}
424 
425 		P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
426 
427 		kfree(ename);
428 	} else
429 		err = 0;
430 
431 	return err;
432 }
433 
434 /**
435  * p9_client_flush - flush (cancel) a request
436  * c: client state
437  * req: request to cancel
438  *
439  * This sents a flush for a particular requests and links
440  * the flush request to the original request.  The current
441  * code only supports a single flush request although the protocol
442  * allows for multiple flush requests to be sent for a single request.
443  *
444  */
445 
446 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
447 {
448 	struct p9_req_t *req;
449 	int16_t oldtag;
450 	int err;
451 
452 	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
453 	if (err)
454 		return err;
455 
456 	P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
457 
458 	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
459 	if (IS_ERR(req))
460 		return PTR_ERR(req);
461 
462 
463 	/* if we haven't received a response for oldreq,
464 	   remove it from the list. */
465 	spin_lock(&c->lock);
466 	if (oldreq->status == REQ_STATUS_FLSH)
467 		list_del(&oldreq->req_list);
468 	spin_unlock(&c->lock);
469 
470 	p9_free_req(c, req);
471 	return 0;
472 }
473 
474 /**
475  * p9_client_rpc - issue a request and wait for a response
476  * @c: client session
477  * @type: type of request
478  * @fmt: protocol format string (see protocol.c)
479  *
480  * Returns request structure (which client must free using p9_free_req)
481  */
482 
483 static struct p9_req_t *
484 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
485 {
486 	va_list ap;
487 	int tag, err;
488 	struct p9_req_t *req;
489 	unsigned long flags;
490 	int sigpending;
491 
492 	P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
493 
494 	if (c->status != Connected)
495 		return ERR_PTR(-EIO);
496 
497 	if (signal_pending(current)) {
498 		sigpending = 1;
499 		clear_thread_flag(TIF_SIGPENDING);
500 	} else
501 		sigpending = 0;
502 
503 	tag = P9_NOTAG;
504 	if (type != P9_TVERSION) {
505 		tag = p9_idpool_get(c->tagpool);
506 		if (tag < 0)
507 			return ERR_PTR(-ENOMEM);
508 	}
509 
510 	req = p9_tag_alloc(c, tag);
511 	if (IS_ERR(req))
512 		return req;
513 
514 	/* marshall the data */
515 	p9pdu_prepare(req->tc, tag, type);
516 	va_start(ap, fmt);
517 	err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
518 	va_end(ap);
519 	p9pdu_finalize(req->tc);
520 
521 	err = c->trans_mod->request(c, req);
522 	if (err < 0) {
523 		c->status = Disconnected;
524 		goto reterr;
525 	}
526 
527 	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
528 	err = wait_event_interruptible(*req->wq,
529 						req->status >= REQ_STATUS_RCVD);
530 	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
531 						req->wq, tag, err);
532 
533 	if (req->status == REQ_STATUS_ERROR) {
534 		P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
535 		err = req->t_err;
536 	}
537 
538 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
539 		P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
540 		sigpending = 1;
541 		clear_thread_flag(TIF_SIGPENDING);
542 
543 		if (c->trans_mod->cancel(c, req))
544 			p9_client_flush(c, req);
545 
546 		/* if we received the response anyway, don't signal error */
547 		if (req->status == REQ_STATUS_RCVD)
548 			err = 0;
549 	}
550 
551 	if (sigpending) {
552 		spin_lock_irqsave(&current->sighand->siglock, flags);
553 		recalc_sigpending();
554 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
555 	}
556 
557 	if (err < 0)
558 		goto reterr;
559 
560 	err = p9_check_errors(c, req);
561 	if (!err) {
562 		P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
563 		return req;
564 	}
565 
566 reterr:
567 	P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
568 									err);
569 	p9_free_req(c, req);
570 	return ERR_PTR(err);
571 }
572 
573 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
574 {
575 	int ret;
576 	struct p9_fid *fid;
577 	unsigned long flags;
578 
579 	P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
580 	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
581 	if (!fid)
582 		return ERR_PTR(-ENOMEM);
583 
584 	ret = p9_idpool_get(clnt->fidpool);
585 	if (ret < 0) {
586 		ret = -ENOSPC;
587 		goto error;
588 	}
589 	fid->fid = ret;
590 
591 	memset(&fid->qid, 0, sizeof(struct p9_qid));
592 	fid->mode = -1;
593 	fid->rdir_fpos = 0;
594 	fid->uid = current_fsuid();
595 	fid->clnt = clnt;
596 	fid->aux = NULL;
597 
598 	spin_lock_irqsave(&clnt->lock, flags);
599 	list_add(&fid->flist, &clnt->fidlist);
600 	spin_unlock_irqrestore(&clnt->lock, flags);
601 
602 	return fid;
603 
604 error:
605 	kfree(fid);
606 	return ERR_PTR(ret);
607 }
608 
609 static void p9_fid_destroy(struct p9_fid *fid)
610 {
611 	struct p9_client *clnt;
612 	unsigned long flags;
613 
614 	P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
615 	clnt = fid->clnt;
616 	p9_idpool_put(fid->fid, clnt->fidpool);
617 	spin_lock_irqsave(&clnt->lock, flags);
618 	list_del(&fid->flist);
619 	spin_unlock_irqrestore(&clnt->lock, flags);
620 	kfree(fid);
621 }
622 
623 int p9_client_version(struct p9_client *c)
624 {
625 	int err = 0;
626 	struct p9_req_t *req;
627 	char *version;
628 	int msize;
629 
630 	P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
631 							c->msize, c->dotu);
632 	req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
633 				c->dotu ? "9P2000.u" : "9P2000");
634 	if (IS_ERR(req))
635 		return PTR_ERR(req);
636 
637 	err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
638 	if (err) {
639 		P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
640 		p9pdu_dump(1, req->rc);
641 		goto error;
642 	}
643 
644 	P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
645 	if (!memcmp(version, "9P2000.u", 8))
646 		c->dotu = 1;
647 	else if (!memcmp(version, "9P2000", 6))
648 		c->dotu = 0;
649 	else {
650 		err = -EREMOTEIO;
651 		goto error;
652 	}
653 
654 	if (msize < c->msize)
655 		c->msize = msize;
656 
657 error:
658 	kfree(version);
659 	p9_free_req(c, req);
660 
661 	return err;
662 }
663 EXPORT_SYMBOL(p9_client_version);
664 
665 struct p9_client *p9_client_create(const char *dev_name, char *options)
666 {
667 	int err;
668 	struct p9_client *clnt;
669 
670 	err = 0;
671 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
672 	if (!clnt)
673 		return ERR_PTR(-ENOMEM);
674 
675 	clnt->trans_mod = NULL;
676 	clnt->trans = NULL;
677 	spin_lock_init(&clnt->lock);
678 	INIT_LIST_HEAD(&clnt->fidlist);
679 	clnt->fidpool = p9_idpool_create();
680 	if (IS_ERR(clnt->fidpool)) {
681 		err = PTR_ERR(clnt->fidpool);
682 		clnt->fidpool = NULL;
683 		goto error;
684 	}
685 
686 	p9_tag_init(clnt);
687 
688 	err = parse_opts(options, clnt);
689 	if (err < 0)
690 		goto error;
691 
692 	if (clnt->trans_mod == NULL) {
693 		err = -EPROTONOSUPPORT;
694 		P9_DPRINTK(P9_DEBUG_ERROR,
695 				"No transport defined or default transport\n");
696 		goto error;
697 	}
698 
699 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
700 		clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
701 
702 	err = clnt->trans_mod->create(clnt, dev_name, options);
703 	if (err)
704 		goto error;
705 
706 	if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
707 		clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
708 
709 	err = p9_client_version(clnt);
710 	if (err)
711 		goto error;
712 
713 	return clnt;
714 
715 error:
716 	p9_client_destroy(clnt);
717 	return ERR_PTR(err);
718 }
719 EXPORT_SYMBOL(p9_client_create);
720 
721 void p9_client_destroy(struct p9_client *clnt)
722 {
723 	struct p9_fid *fid, *fidptr;
724 
725 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
726 
727 	if (clnt->trans_mod)
728 		clnt->trans_mod->close(clnt);
729 
730 	v9fs_put_trans(clnt->trans_mod);
731 
732 	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
733 		p9_fid_destroy(fid);
734 
735 	if (clnt->fidpool)
736 		p9_idpool_destroy(clnt->fidpool);
737 
738 	p9_tag_cleanup(clnt);
739 
740 	kfree(clnt);
741 }
742 EXPORT_SYMBOL(p9_client_destroy);
743 
744 void p9_client_disconnect(struct p9_client *clnt)
745 {
746 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
747 	clnt->status = Disconnected;
748 }
749 EXPORT_SYMBOL(p9_client_disconnect);
750 
751 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
752 	char *uname, u32 n_uname, char *aname)
753 {
754 	int err;
755 	struct p9_req_t *req;
756 	struct p9_fid *fid;
757 	struct p9_qid qid;
758 
759 	P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
760 					afid ? afid->fid : -1, uname, aname);
761 	err = 0;
762 
763 	fid = p9_fid_create(clnt);
764 	if (IS_ERR(fid)) {
765 		err = PTR_ERR(fid);
766 		fid = NULL;
767 		goto error;
768 	}
769 
770 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
771 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
772 	if (IS_ERR(req)) {
773 		err = PTR_ERR(req);
774 		goto error;
775 	}
776 
777 	err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
778 	if (err) {
779 		p9pdu_dump(1, req->rc);
780 		p9_free_req(clnt, req);
781 		goto error;
782 	}
783 
784 	P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
785 					qid.type,
786 					(unsigned long long)qid.path,
787 					qid.version);
788 
789 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
790 
791 	p9_free_req(clnt, req);
792 	return fid;
793 
794 error:
795 	if (fid)
796 		p9_fid_destroy(fid);
797 	return ERR_PTR(err);
798 }
799 EXPORT_SYMBOL(p9_client_attach);
800 
801 struct p9_fid *
802 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
803 {
804 	int err;
805 	struct p9_req_t *req;
806 	struct p9_qid qid;
807 	struct p9_fid *afid;
808 
809 	P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
810 	err = 0;
811 
812 	afid = p9_fid_create(clnt);
813 	if (IS_ERR(afid)) {
814 		err = PTR_ERR(afid);
815 		afid = NULL;
816 		goto error;
817 	}
818 
819 	req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
820 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
821 	if (IS_ERR(req)) {
822 		err = PTR_ERR(req);
823 		goto error;
824 	}
825 
826 	err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
827 	if (err) {
828 		p9pdu_dump(1, req->rc);
829 		p9_free_req(clnt, req);
830 		goto error;
831 	}
832 
833 	P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
834 					qid.type,
835 					(unsigned long long)qid.path,
836 					qid.version);
837 
838 	memmove(&afid->qid, &qid, sizeof(struct p9_qid));
839 	p9_free_req(clnt, req);
840 	return afid;
841 
842 error:
843 	if (afid)
844 		p9_fid_destroy(afid);
845 	return ERR_PTR(err);
846 }
847 EXPORT_SYMBOL(p9_client_auth);
848 
849 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
850 	int clone)
851 {
852 	int err;
853 	struct p9_client *clnt;
854 	struct p9_fid *fid;
855 	struct p9_qid *wqids;
856 	struct p9_req_t *req;
857 	int16_t nwqids, count;
858 
859 	err = 0;
860 	clnt = oldfid->clnt;
861 	if (clone) {
862 		fid = p9_fid_create(clnt);
863 		if (IS_ERR(fid)) {
864 			err = PTR_ERR(fid);
865 			fid = NULL;
866 			goto error;
867 		}
868 
869 		fid->uid = oldfid->uid;
870 	} else
871 		fid = oldfid;
872 
873 
874 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
875 		oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
876 
877 	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
878 								nwname, wnames);
879 	if (IS_ERR(req)) {
880 		err = PTR_ERR(req);
881 		goto error;
882 	}
883 
884 	err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
885 	if (err) {
886 		p9pdu_dump(1, req->rc);
887 		p9_free_req(clnt, req);
888 		goto clunk_fid;
889 	}
890 	p9_free_req(clnt, req);
891 
892 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
893 
894 	if (nwqids != nwname) {
895 		err = -ENOENT;
896 		goto clunk_fid;
897 	}
898 
899 	for (count = 0; count < nwqids; count++)
900 		P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
901 			count, wqids[count].type,
902 			(unsigned long long)wqids[count].path,
903 			wqids[count].version);
904 
905 	if (nwname)
906 		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
907 	else
908 		fid->qid = oldfid->qid;
909 
910 	return fid;
911 
912 clunk_fid:
913 	p9_client_clunk(fid);
914 	fid = NULL;
915 
916 error:
917 	if (fid && (fid != oldfid))
918 		p9_fid_destroy(fid);
919 
920 	return ERR_PTR(err);
921 }
922 EXPORT_SYMBOL(p9_client_walk);
923 
924 int p9_client_open(struct p9_fid *fid, int mode)
925 {
926 	int err;
927 	struct p9_client *clnt;
928 	struct p9_req_t *req;
929 	struct p9_qid qid;
930 	int iounit;
931 
932 	P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
933 	err = 0;
934 	clnt = fid->clnt;
935 
936 	if (fid->mode != -1)
937 		return -EINVAL;
938 
939 	req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
940 	if (IS_ERR(req)) {
941 		err = PTR_ERR(req);
942 		goto error;
943 	}
944 
945 	err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
946 	if (err) {
947 		p9pdu_dump(1, req->rc);
948 		goto free_and_error;
949 	}
950 
951 	P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
952 				qid.type,
953 				(unsigned long long)qid.path,
954 				qid.version, iounit);
955 
956 	fid->mode = mode;
957 	fid->iounit = iounit;
958 
959 free_and_error:
960 	p9_free_req(clnt, req);
961 error:
962 	return err;
963 }
964 EXPORT_SYMBOL(p9_client_open);
965 
966 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
967 		     char *extension)
968 {
969 	int err;
970 	struct p9_client *clnt;
971 	struct p9_req_t *req;
972 	struct p9_qid qid;
973 	int iounit;
974 
975 	P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
976 						fid->fid, name, perm, mode);
977 	err = 0;
978 	clnt = fid->clnt;
979 
980 	if (fid->mode != -1)
981 		return -EINVAL;
982 
983 	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
984 				mode, extension);
985 	if (IS_ERR(req)) {
986 		err = PTR_ERR(req);
987 		goto error;
988 	}
989 
990 	err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
991 	if (err) {
992 		p9pdu_dump(1, req->rc);
993 		goto free_and_error;
994 	}
995 
996 	P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
997 				qid.type,
998 				(unsigned long long)qid.path,
999 				qid.version, iounit);
1000 
1001 	fid->mode = mode;
1002 	fid->iounit = iounit;
1003 
1004 free_and_error:
1005 	p9_free_req(clnt, req);
1006 error:
1007 	return err;
1008 }
1009 EXPORT_SYMBOL(p9_client_fcreate);
1010 
1011 int p9_client_clunk(struct p9_fid *fid)
1012 {
1013 	int err;
1014 	struct p9_client *clnt;
1015 	struct p9_req_t *req;
1016 
1017 	P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1018 	err = 0;
1019 	clnt = fid->clnt;
1020 
1021 	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1022 	if (IS_ERR(req)) {
1023 		err = PTR_ERR(req);
1024 		goto error;
1025 	}
1026 
1027 	P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1028 
1029 	p9_free_req(clnt, req);
1030 	p9_fid_destroy(fid);
1031 
1032 error:
1033 	return err;
1034 }
1035 EXPORT_SYMBOL(p9_client_clunk);
1036 
1037 int p9_client_remove(struct p9_fid *fid)
1038 {
1039 	int err;
1040 	struct p9_client *clnt;
1041 	struct p9_req_t *req;
1042 
1043 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1044 	err = 0;
1045 	clnt = fid->clnt;
1046 
1047 	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1048 	if (IS_ERR(req)) {
1049 		err = PTR_ERR(req);
1050 		goto error;
1051 	}
1052 
1053 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1054 
1055 	p9_free_req(clnt, req);
1056 	p9_fid_destroy(fid);
1057 
1058 error:
1059 	return err;
1060 }
1061 EXPORT_SYMBOL(p9_client_remove);
1062 
1063 int
1064 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1065 								u32 count)
1066 {
1067 	int err, rsize, total;
1068 	struct p9_client *clnt;
1069 	struct p9_req_t *req;
1070 	char *dataptr;
1071 
1072 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1073 					(long long unsigned) offset, count);
1074 	err = 0;
1075 	clnt = fid->clnt;
1076 	total = 0;
1077 
1078 	rsize = fid->iounit;
1079 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1080 		rsize = clnt->msize - P9_IOHDRSZ;
1081 
1082 	if (count < rsize)
1083 		rsize = count;
1084 
1085 	req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1086 	if (IS_ERR(req)) {
1087 		err = PTR_ERR(req);
1088 		goto error;
1089 	}
1090 
1091 	err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1092 	if (err) {
1093 		p9pdu_dump(1, req->rc);
1094 		goto free_and_error;
1095 	}
1096 
1097 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1098 
1099 	if (data) {
1100 		memmove(data, dataptr, count);
1101 		data += count;
1102 	}
1103 
1104 	if (udata) {
1105 		err = copy_to_user(udata, dataptr, count);
1106 		if (err) {
1107 			err = -EFAULT;
1108 			goto free_and_error;
1109 		}
1110 	}
1111 
1112 	p9_free_req(clnt, req);
1113 	return count;
1114 
1115 free_and_error:
1116 	p9_free_req(clnt, req);
1117 error:
1118 	return err;
1119 }
1120 EXPORT_SYMBOL(p9_client_read);
1121 
1122 int
1123 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1124 							u64 offset, u32 count)
1125 {
1126 	int err, rsize, total;
1127 	struct p9_client *clnt;
1128 	struct p9_req_t *req;
1129 
1130 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1131 				fid->fid, (long long unsigned) offset, count);
1132 	err = 0;
1133 	clnt = fid->clnt;
1134 	total = 0;
1135 
1136 	rsize = fid->iounit;
1137 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1138 		rsize = clnt->msize - P9_IOHDRSZ;
1139 
1140 	if (count < rsize)
1141 		rsize = count;
1142 	if (data)
1143 		req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1144 								rsize, data);
1145 	else
1146 		req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1147 								rsize, udata);
1148 	if (IS_ERR(req)) {
1149 		err = PTR_ERR(req);
1150 		goto error;
1151 	}
1152 
1153 	err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1154 	if (err) {
1155 		p9pdu_dump(1, req->rc);
1156 		goto free_and_error;
1157 	}
1158 
1159 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1160 
1161 	p9_free_req(clnt, req);
1162 	return count;
1163 
1164 free_and_error:
1165 	p9_free_req(clnt, req);
1166 error:
1167 	return err;
1168 }
1169 EXPORT_SYMBOL(p9_client_write);
1170 
1171 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1172 {
1173 	int err;
1174 	struct p9_client *clnt;
1175 	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1176 	struct p9_req_t *req;
1177 	u16 ignored;
1178 
1179 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1180 
1181 	if (!ret)
1182 		return ERR_PTR(-ENOMEM);
1183 
1184 	err = 0;
1185 	clnt = fid->clnt;
1186 
1187 	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1188 	if (IS_ERR(req)) {
1189 		err = PTR_ERR(req);
1190 		goto error;
1191 	}
1192 
1193 	err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1194 	if (err) {
1195 		ret = ERR_PTR(err);
1196 		p9pdu_dump(1, req->rc);
1197 		goto free_and_error;
1198 	}
1199 
1200 	P9_DPRINTK(P9_DEBUG_9P,
1201 		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1202 		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1203 		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1204 		"<<<    uid=%d gid=%d n_muid=%d\n",
1205 		ret->size, ret->type, ret->dev, ret->qid.type,
1206 		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1207 		ret->atime, ret->mtime, (unsigned long long)ret->length,
1208 		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1209 		ret->n_uid, ret->n_gid, ret->n_muid);
1210 
1211 	p9_free_req(clnt, req);
1212 	return ret;
1213 
1214 free_and_error:
1215 	p9_free_req(clnt, req);
1216 error:
1217 	kfree(ret);
1218 	return ERR_PTR(err);
1219 }
1220 EXPORT_SYMBOL(p9_client_stat);
1221 
1222 static int p9_client_statsize(struct p9_wstat *wst, int optional)
1223 {
1224 	int ret;
1225 
1226 	/* size[2] type[2] dev[4] qid[13] */
1227 	/* mode[4] atime[4] mtime[4] length[8]*/
1228 	/* name[s] uid[s] gid[s] muid[s] */
1229 	ret = 2+2+4+13+4+4+4+8+2+2+2+2;
1230 
1231 	if (wst->name)
1232 		ret += strlen(wst->name);
1233 	if (wst->uid)
1234 		ret += strlen(wst->uid);
1235 	if (wst->gid)
1236 		ret += strlen(wst->gid);
1237 	if (wst->muid)
1238 		ret += strlen(wst->muid);
1239 
1240 	if (optional) {
1241 		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1242 		if (wst->extension)
1243 			ret += strlen(wst->extension);
1244 	}
1245 
1246 	return ret;
1247 }
1248 
1249 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1250 {
1251 	int err;
1252 	struct p9_req_t *req;
1253 	struct p9_client *clnt;
1254 
1255 	err = 0;
1256 	clnt = fid->clnt;
1257 	wst->size = p9_client_statsize(wst, clnt->dotu);
1258 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1259 	P9_DPRINTK(P9_DEBUG_9P,
1260 		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1261 		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1262 		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1263 		"     uid=%d gid=%d n_muid=%d\n",
1264 		wst->size, wst->type, wst->dev, wst->qid.type,
1265 		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1266 		wst->atime, wst->mtime, (unsigned long long)wst->length,
1267 		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1268 		wst->n_uid, wst->n_gid, wst->n_muid);
1269 
1270 	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size, wst);
1271 	if (IS_ERR(req)) {
1272 		err = PTR_ERR(req);
1273 		goto error;
1274 	}
1275 
1276 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1277 
1278 	p9_free_req(clnt, req);
1279 error:
1280 	return err;
1281 }
1282 EXPORT_SYMBOL(p9_client_wstat);
1283