xref: /openbmc/linux/net/9p/client.c (revision fd589a8f)
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  * parse_options - parse mount options into client structure
64  * @opts: options string passed from mount
65  * @clnt: existing v9fs client 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 	kfree(options);
121 	return ret;
122 }
123 
124 /**
125  * p9_tag_alloc - lookup/allocate a request by tag
126  * @c: client session to lookup tag within
127  * @tag: numeric id for transaction
128  *
129  * this is a simple array lookup, but will grow the
130  * request_slots as necessary to accomodate transaction
131  * ids which did not previously have a slot.
132  *
133  * this code relies on the client spinlock to manage locks, its
134  * possible we should switch to something else, but I'd rather
135  * stick with something low-overhead for the common case.
136  *
137  */
138 
139 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
140 {
141 	unsigned long flags;
142 	int row, col;
143 	struct p9_req_t *req;
144 
145 	/* This looks up the original request by tag so we know which
146 	 * buffer to read the data into */
147 	tag++;
148 
149 	if (tag >= c->max_tag) {
150 		spin_lock_irqsave(&c->lock, flags);
151 		/* check again since original check was outside of lock */
152 		while (tag >= c->max_tag) {
153 			row = (tag / P9_ROW_MAXTAG);
154 			c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
155 					sizeof(struct p9_req_t), GFP_ATOMIC);
156 
157 			if (!c->reqs[row]) {
158 				printk(KERN_ERR "Couldn't grow tag array\n");
159 				spin_unlock_irqrestore(&c->lock, flags);
160 				return ERR_PTR(-ENOMEM);
161 			}
162 			for (col = 0; col < P9_ROW_MAXTAG; col++) {
163 				c->reqs[row][col].status = REQ_STATUS_IDLE;
164 				c->reqs[row][col].tc = NULL;
165 			}
166 			c->max_tag += P9_ROW_MAXTAG;
167 		}
168 		spin_unlock_irqrestore(&c->lock, flags);
169 	}
170 	row = tag / P9_ROW_MAXTAG;
171 	col = tag % P9_ROW_MAXTAG;
172 
173 	req = &c->reqs[row][col];
174 	if (!req->tc) {
175 		req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
176 		if (!req->wq) {
177 			printk(KERN_ERR "Couldn't grow tag array\n");
178 			return ERR_PTR(-ENOMEM);
179 		}
180 		init_waitqueue_head(req->wq);
181 		req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
182 								GFP_KERNEL);
183 		req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
184 								GFP_KERNEL);
185 		if ((!req->tc) || (!req->rc)) {
186 			printk(KERN_ERR "Couldn't grow tag array\n");
187 			kfree(req->tc);
188 			kfree(req->rc);
189 			kfree(req->wq);
190 			req->tc = req->rc = NULL;
191 			req->wq = NULL;
192 			return ERR_PTR(-ENOMEM);
193 		}
194 		req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
195 		req->tc->capacity = c->msize;
196 		req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
197 		req->rc->capacity = c->msize;
198 	}
199 
200 	p9pdu_reset(req->tc);
201 	p9pdu_reset(req->rc);
202 
203 	req->tc->tag = tag-1;
204 	req->status = REQ_STATUS_ALLOC;
205 
206 	return &c->reqs[row][col];
207 }
208 
209 /**
210  * p9_tag_lookup - lookup a request by tag
211  * @c: client session to lookup tag within
212  * @tag: numeric id for transaction
213  *
214  */
215 
216 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
217 {
218 	int row, col;
219 
220 	/* This looks up the original request by tag so we know which
221 	 * buffer to read the data into */
222 	tag++;
223 
224 	BUG_ON(tag >= c->max_tag);
225 
226 	row = tag / P9_ROW_MAXTAG;
227 	col = tag % P9_ROW_MAXTAG;
228 
229 	return &c->reqs[row][col];
230 }
231 EXPORT_SYMBOL(p9_tag_lookup);
232 
233 /**
234  * p9_tag_init - setup tags structure and contents
235  * @c:  v9fs client struct
236  *
237  * This initializes the tags structure for each client instance.
238  *
239  */
240 
241 static int p9_tag_init(struct p9_client *c)
242 {
243 	int err = 0;
244 
245 	c->tagpool = p9_idpool_create();
246 	if (IS_ERR(c->tagpool)) {
247 		err = PTR_ERR(c->tagpool);
248 		c->tagpool = NULL;
249 		goto error;
250 	}
251 
252 	p9_idpool_get(c->tagpool); /* reserve tag 0 */
253 
254 	c->max_tag = 0;
255 error:
256 	return err;
257 }
258 
259 /**
260  * p9_tag_cleanup - cleans up tags structure and reclaims resources
261  * @c:  v9fs client struct
262  *
263  * This frees resources associated with the tags structure
264  *
265  */
266 static void p9_tag_cleanup(struct p9_client *c)
267 {
268 	int row, col;
269 
270 	/* check to insure all requests are idle */
271 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
272 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
273 			if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
274 				P9_DPRINTK(P9_DEBUG_MUX,
275 				  "Attempting to cleanup non-free tag %d,%d\n",
276 				  row, col);
277 				/* TODO: delay execution of cleanup */
278 				return;
279 			}
280 		}
281 	}
282 
283 	if (c->tagpool)
284 		p9_idpool_destroy(c->tagpool);
285 
286 	/* free requests associated with tags */
287 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
288 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
289 			kfree(c->reqs[row][col].wq);
290 			kfree(c->reqs[row][col].tc);
291 			kfree(c->reqs[row][col].rc);
292 		}
293 		kfree(c->reqs[row]);
294 	}
295 	c->max_tag = 0;
296 }
297 
298 /**
299  * p9_free_req - free a request and clean-up as necessary
300  * c: client state
301  * r: request to release
302  *
303  */
304 
305 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
306 {
307 	int tag = r->tc->tag;
308 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
309 
310 	r->status = REQ_STATUS_IDLE;
311 	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
312 		p9_idpool_put(tag, c->tagpool);
313 }
314 
315 /**
316  * p9_client_cb - call back from transport to client
317  * c: client state
318  * req: request received
319  *
320  */
321 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
322 {
323 	P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
324 	wake_up(req->wq);
325 	P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
326 }
327 EXPORT_SYMBOL(p9_client_cb);
328 
329 /**
330  * p9_parse_header - parse header arguments out of a packet
331  * @pdu: packet to parse
332  * @size: size of packet
333  * @type: type of request
334  * @tag: tag of packet
335  * @rewind: set if we need to rewind offset afterwards
336  */
337 
338 int
339 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
340 								int rewind)
341 {
342 	int8_t r_type;
343 	int16_t r_tag;
344 	int32_t r_size;
345 	int offset = pdu->offset;
346 	int err;
347 
348 	pdu->offset = 0;
349 	if (pdu->size == 0)
350 		pdu->size = 7;
351 
352 	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
353 	if (err)
354 		goto rewind_and_exit;
355 
356 	pdu->size = r_size;
357 	pdu->id = r_type;
358 	pdu->tag = r_tag;
359 
360 	P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
361 							pdu->id, pdu->tag);
362 
363 	if (type)
364 		*type = r_type;
365 	if (tag)
366 		*tag = r_tag;
367 	if (size)
368 		*size = r_size;
369 
370 
371 rewind_and_exit:
372 	if (rewind)
373 		pdu->offset = offset;
374 	return err;
375 }
376 EXPORT_SYMBOL(p9_parse_header);
377 
378 /**
379  * p9_check_errors - check 9p packet for error return and process it
380  * @c: current client instance
381  * @req: request to parse and check for error conditions
382  *
383  * returns error code if one is discovered, otherwise returns 0
384  *
385  * this will have to be more complicated if we have multiple
386  * error packet types
387  */
388 
389 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
390 {
391 	int8_t type;
392 	int err;
393 
394 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
395 	if (err) {
396 		P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
397 		return err;
398 	}
399 
400 	if (type == P9_RERROR) {
401 		int ecode;
402 		char *ename;
403 
404 		err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
405 		if (err) {
406 			P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
407 									err);
408 			return err;
409 		}
410 
411 		if (c->dotu)
412 			err = -ecode;
413 
414 		if (!err || !IS_ERR_VALUE(err))
415 			err = p9_errstr2errno(ename, strlen(ename));
416 
417 		P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
418 
419 		kfree(ename);
420 	} else
421 		err = 0;
422 
423 	return err;
424 }
425 
426 /**
427  * p9_client_flush - flush (cancel) a request
428  * @c: client state
429  * @oldreq: request to cancel
430  *
431  * This sents a flush for a particular requests and links
432  * the flush request to the original request.  The current
433  * code only supports a single flush request although the protocol
434  * allows for multiple flush requests to be sent for a single request.
435  *
436  */
437 
438 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
439 {
440 	struct p9_req_t *req;
441 	int16_t oldtag;
442 	int err;
443 
444 	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
445 	if (err)
446 		return err;
447 
448 	P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
449 
450 	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
451 	if (IS_ERR(req))
452 		return PTR_ERR(req);
453 
454 
455 	/* if we haven't received a response for oldreq,
456 	   remove it from the list. */
457 	spin_lock(&c->lock);
458 	if (oldreq->status == REQ_STATUS_FLSH)
459 		list_del(&oldreq->req_list);
460 	spin_unlock(&c->lock);
461 
462 	p9_free_req(c, req);
463 	return 0;
464 }
465 
466 /**
467  * p9_client_rpc - issue a request and wait for a response
468  * @c: client session
469  * @type: type of request
470  * @fmt: protocol format string (see protocol.c)
471  *
472  * Returns request structure (which client must free using p9_free_req)
473  */
474 
475 static struct p9_req_t *
476 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
477 {
478 	va_list ap;
479 	int tag, err;
480 	struct p9_req_t *req;
481 	unsigned long flags;
482 	int sigpending;
483 
484 	P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
485 
486 	if (c->status != Connected)
487 		return ERR_PTR(-EIO);
488 
489 	if (signal_pending(current)) {
490 		sigpending = 1;
491 		clear_thread_flag(TIF_SIGPENDING);
492 	} else
493 		sigpending = 0;
494 
495 	tag = P9_NOTAG;
496 	if (type != P9_TVERSION) {
497 		tag = p9_idpool_get(c->tagpool);
498 		if (tag < 0)
499 			return ERR_PTR(-ENOMEM);
500 	}
501 
502 	req = p9_tag_alloc(c, tag);
503 	if (IS_ERR(req))
504 		return req;
505 
506 	/* marshall the data */
507 	p9pdu_prepare(req->tc, tag, type);
508 	va_start(ap, fmt);
509 	err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
510 	va_end(ap);
511 	p9pdu_finalize(req->tc);
512 
513 	err = c->trans_mod->request(c, req);
514 	if (err < 0) {
515 		c->status = Disconnected;
516 		goto reterr;
517 	}
518 
519 	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
520 	err = wait_event_interruptible(*req->wq,
521 						req->status >= REQ_STATUS_RCVD);
522 	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
523 						req->wq, tag, err);
524 
525 	if (req->status == REQ_STATUS_ERROR) {
526 		P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
527 		err = req->t_err;
528 	}
529 
530 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
531 		P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
532 		sigpending = 1;
533 		clear_thread_flag(TIF_SIGPENDING);
534 
535 		if (c->trans_mod->cancel(c, req))
536 			p9_client_flush(c, req);
537 
538 		/* if we received the response anyway, don't signal error */
539 		if (req->status == REQ_STATUS_RCVD)
540 			err = 0;
541 	}
542 
543 	if (sigpending) {
544 		spin_lock_irqsave(&current->sighand->siglock, flags);
545 		recalc_sigpending();
546 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
547 	}
548 
549 	if (err < 0)
550 		goto reterr;
551 
552 	err = p9_check_errors(c, req);
553 	if (!err) {
554 		P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
555 		return req;
556 	}
557 
558 reterr:
559 	P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
560 									err);
561 	p9_free_req(c, req);
562 	return ERR_PTR(err);
563 }
564 
565 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
566 {
567 	int ret;
568 	struct p9_fid *fid;
569 	unsigned long flags;
570 
571 	P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
572 	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
573 	if (!fid)
574 		return ERR_PTR(-ENOMEM);
575 
576 	ret = p9_idpool_get(clnt->fidpool);
577 	if (ret < 0) {
578 		ret = -ENOSPC;
579 		goto error;
580 	}
581 	fid->fid = ret;
582 
583 	memset(&fid->qid, 0, sizeof(struct p9_qid));
584 	fid->mode = -1;
585 	fid->rdir_fpos = 0;
586 	fid->uid = current_fsuid();
587 	fid->clnt = clnt;
588 	fid->aux = NULL;
589 
590 	spin_lock_irqsave(&clnt->lock, flags);
591 	list_add(&fid->flist, &clnt->fidlist);
592 	spin_unlock_irqrestore(&clnt->lock, flags);
593 
594 	return fid;
595 
596 error:
597 	kfree(fid);
598 	return ERR_PTR(ret);
599 }
600 
601 static void p9_fid_destroy(struct p9_fid *fid)
602 {
603 	struct p9_client *clnt;
604 	unsigned long flags;
605 
606 	P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
607 	clnt = fid->clnt;
608 	p9_idpool_put(fid->fid, clnt->fidpool);
609 	spin_lock_irqsave(&clnt->lock, flags);
610 	list_del(&fid->flist);
611 	spin_unlock_irqrestore(&clnt->lock, flags);
612 	kfree(fid);
613 }
614 
615 int p9_client_version(struct p9_client *c)
616 {
617 	int err = 0;
618 	struct p9_req_t *req;
619 	char *version;
620 	int msize;
621 
622 	P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
623 							c->msize, c->dotu);
624 	req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
625 				c->dotu ? "9P2000.u" : "9P2000");
626 	if (IS_ERR(req))
627 		return PTR_ERR(req);
628 
629 	err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
630 	if (err) {
631 		P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
632 		p9pdu_dump(1, req->rc);
633 		goto error;
634 	}
635 
636 	P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
637 	if (!memcmp(version, "9P2000.u", 8))
638 		c->dotu = 1;
639 	else if (!memcmp(version, "9P2000", 6))
640 		c->dotu = 0;
641 	else {
642 		err = -EREMOTEIO;
643 		goto error;
644 	}
645 
646 	if (msize < c->msize)
647 		c->msize = msize;
648 
649 error:
650 	kfree(version);
651 	p9_free_req(c, req);
652 
653 	return err;
654 }
655 EXPORT_SYMBOL(p9_client_version);
656 
657 struct p9_client *p9_client_create(const char *dev_name, char *options)
658 {
659 	int err;
660 	struct p9_client *clnt;
661 
662 	err = 0;
663 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
664 	if (!clnt)
665 		return ERR_PTR(-ENOMEM);
666 
667 	clnt->trans_mod = NULL;
668 	clnt->trans = NULL;
669 	spin_lock_init(&clnt->lock);
670 	INIT_LIST_HEAD(&clnt->fidlist);
671 	clnt->fidpool = p9_idpool_create();
672 	if (IS_ERR(clnt->fidpool)) {
673 		err = PTR_ERR(clnt->fidpool);
674 		clnt->fidpool = NULL;
675 		goto error;
676 	}
677 
678 	p9_tag_init(clnt);
679 
680 	err = parse_opts(options, clnt);
681 	if (err < 0)
682 		goto error;
683 
684 	if (!clnt->trans_mod)
685 		clnt->trans_mod = v9fs_get_default_trans();
686 
687 	if (clnt->trans_mod == NULL) {
688 		err = -EPROTONOSUPPORT;
689 		P9_DPRINTK(P9_DEBUG_ERROR,
690 				"No transport defined or default transport\n");
691 		goto error;
692 	}
693 
694 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
695 		clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
696 
697 	err = clnt->trans_mod->create(clnt, dev_name, options);
698 	if (err)
699 		goto error;
700 
701 	if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
702 		clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
703 
704 	err = p9_client_version(clnt);
705 	if (err)
706 		goto error;
707 
708 	return clnt;
709 
710 error:
711 	p9_client_destroy(clnt);
712 	return ERR_PTR(err);
713 }
714 EXPORT_SYMBOL(p9_client_create);
715 
716 void p9_client_destroy(struct p9_client *clnt)
717 {
718 	struct p9_fid *fid, *fidptr;
719 
720 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
721 
722 	if (clnt->trans_mod)
723 		clnt->trans_mod->close(clnt);
724 
725 	v9fs_put_trans(clnt->trans_mod);
726 
727 	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
728 		p9_fid_destroy(fid);
729 
730 	if (clnt->fidpool)
731 		p9_idpool_destroy(clnt->fidpool);
732 
733 	p9_tag_cleanup(clnt);
734 
735 	kfree(clnt);
736 }
737 EXPORT_SYMBOL(p9_client_destroy);
738 
739 void p9_client_disconnect(struct p9_client *clnt)
740 {
741 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
742 	clnt->status = Disconnected;
743 }
744 EXPORT_SYMBOL(p9_client_disconnect);
745 
746 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
747 	char *uname, u32 n_uname, char *aname)
748 {
749 	int err;
750 	struct p9_req_t *req;
751 	struct p9_fid *fid;
752 	struct p9_qid qid;
753 
754 	P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
755 					afid ? afid->fid : -1, uname, aname);
756 	err = 0;
757 
758 	fid = p9_fid_create(clnt);
759 	if (IS_ERR(fid)) {
760 		err = PTR_ERR(fid);
761 		fid = NULL;
762 		goto error;
763 	}
764 
765 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
766 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
767 	if (IS_ERR(req)) {
768 		err = PTR_ERR(req);
769 		goto error;
770 	}
771 
772 	err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
773 	if (err) {
774 		p9pdu_dump(1, req->rc);
775 		p9_free_req(clnt, req);
776 		goto error;
777 	}
778 
779 	P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
780 					qid.type,
781 					(unsigned long long)qid.path,
782 					qid.version);
783 
784 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
785 
786 	p9_free_req(clnt, req);
787 	return fid;
788 
789 error:
790 	if (fid)
791 		p9_fid_destroy(fid);
792 	return ERR_PTR(err);
793 }
794 EXPORT_SYMBOL(p9_client_attach);
795 
796 struct p9_fid *
797 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
798 {
799 	int err;
800 	struct p9_req_t *req;
801 	struct p9_qid qid;
802 	struct p9_fid *afid;
803 
804 	P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
805 	err = 0;
806 
807 	afid = p9_fid_create(clnt);
808 	if (IS_ERR(afid)) {
809 		err = PTR_ERR(afid);
810 		afid = NULL;
811 		goto error;
812 	}
813 
814 	req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
815 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
816 	if (IS_ERR(req)) {
817 		err = PTR_ERR(req);
818 		goto error;
819 	}
820 
821 	err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
822 	if (err) {
823 		p9pdu_dump(1, req->rc);
824 		p9_free_req(clnt, req);
825 		goto error;
826 	}
827 
828 	P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
829 					qid.type,
830 					(unsigned long long)qid.path,
831 					qid.version);
832 
833 	memmove(&afid->qid, &qid, sizeof(struct p9_qid));
834 	p9_free_req(clnt, req);
835 	return afid;
836 
837 error:
838 	if (afid)
839 		p9_fid_destroy(afid);
840 	return ERR_PTR(err);
841 }
842 EXPORT_SYMBOL(p9_client_auth);
843 
844 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
845 	int clone)
846 {
847 	int err;
848 	struct p9_client *clnt;
849 	struct p9_fid *fid;
850 	struct p9_qid *wqids;
851 	struct p9_req_t *req;
852 	int16_t nwqids, count;
853 
854 	err = 0;
855 	clnt = oldfid->clnt;
856 	if (clone) {
857 		fid = p9_fid_create(clnt);
858 		if (IS_ERR(fid)) {
859 			err = PTR_ERR(fid);
860 			fid = NULL;
861 			goto error;
862 		}
863 
864 		fid->uid = oldfid->uid;
865 	} else
866 		fid = oldfid;
867 
868 
869 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
870 		oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
871 
872 	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
873 								nwname, wnames);
874 	if (IS_ERR(req)) {
875 		err = PTR_ERR(req);
876 		goto error;
877 	}
878 
879 	err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
880 	if (err) {
881 		p9pdu_dump(1, req->rc);
882 		p9_free_req(clnt, req);
883 		goto clunk_fid;
884 	}
885 	p9_free_req(clnt, req);
886 
887 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
888 
889 	if (nwqids != nwname) {
890 		err = -ENOENT;
891 		goto clunk_fid;
892 	}
893 
894 	for (count = 0; count < nwqids; count++)
895 		P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
896 			count, wqids[count].type,
897 			(unsigned long long)wqids[count].path,
898 			wqids[count].version);
899 
900 	if (nwname)
901 		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
902 	else
903 		fid->qid = oldfid->qid;
904 
905 	return fid;
906 
907 clunk_fid:
908 	p9_client_clunk(fid);
909 	fid = NULL;
910 
911 error:
912 	if (fid && (fid != oldfid))
913 		p9_fid_destroy(fid);
914 
915 	return ERR_PTR(err);
916 }
917 EXPORT_SYMBOL(p9_client_walk);
918 
919 int p9_client_open(struct p9_fid *fid, int mode)
920 {
921 	int err;
922 	struct p9_client *clnt;
923 	struct p9_req_t *req;
924 	struct p9_qid qid;
925 	int iounit;
926 
927 	P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
928 	err = 0;
929 	clnt = fid->clnt;
930 
931 	if (fid->mode != -1)
932 		return -EINVAL;
933 
934 	req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
935 	if (IS_ERR(req)) {
936 		err = PTR_ERR(req);
937 		goto error;
938 	}
939 
940 	err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
941 	if (err) {
942 		p9pdu_dump(1, req->rc);
943 		goto free_and_error;
944 	}
945 
946 	P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
947 				qid.type,
948 				(unsigned long long)qid.path,
949 				qid.version, iounit);
950 
951 	fid->mode = mode;
952 	fid->iounit = iounit;
953 
954 free_and_error:
955 	p9_free_req(clnt, req);
956 error:
957 	return err;
958 }
959 EXPORT_SYMBOL(p9_client_open);
960 
961 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
962 		     char *extension)
963 {
964 	int err;
965 	struct p9_client *clnt;
966 	struct p9_req_t *req;
967 	struct p9_qid qid;
968 	int iounit;
969 
970 	P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
971 						fid->fid, name, perm, mode);
972 	err = 0;
973 	clnt = fid->clnt;
974 
975 	if (fid->mode != -1)
976 		return -EINVAL;
977 
978 	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
979 				mode, extension);
980 	if (IS_ERR(req)) {
981 		err = PTR_ERR(req);
982 		goto error;
983 	}
984 
985 	err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
986 	if (err) {
987 		p9pdu_dump(1, req->rc);
988 		goto free_and_error;
989 	}
990 
991 	P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
992 				qid.type,
993 				(unsigned long long)qid.path,
994 				qid.version, iounit);
995 
996 	fid->mode = mode;
997 	fid->iounit = iounit;
998 
999 free_and_error:
1000 	p9_free_req(clnt, req);
1001 error:
1002 	return err;
1003 }
1004 EXPORT_SYMBOL(p9_client_fcreate);
1005 
1006 int p9_client_clunk(struct p9_fid *fid)
1007 {
1008 	int err;
1009 	struct p9_client *clnt;
1010 	struct p9_req_t *req;
1011 
1012 	P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1013 	err = 0;
1014 	clnt = fid->clnt;
1015 
1016 	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1017 	if (IS_ERR(req)) {
1018 		err = PTR_ERR(req);
1019 		goto error;
1020 	}
1021 
1022 	P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1023 
1024 	p9_free_req(clnt, req);
1025 	p9_fid_destroy(fid);
1026 
1027 error:
1028 	return err;
1029 }
1030 EXPORT_SYMBOL(p9_client_clunk);
1031 
1032 int p9_client_remove(struct p9_fid *fid)
1033 {
1034 	int err;
1035 	struct p9_client *clnt;
1036 	struct p9_req_t *req;
1037 
1038 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1039 	err = 0;
1040 	clnt = fid->clnt;
1041 
1042 	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1043 	if (IS_ERR(req)) {
1044 		err = PTR_ERR(req);
1045 		goto error;
1046 	}
1047 
1048 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1049 
1050 	p9_free_req(clnt, req);
1051 	p9_fid_destroy(fid);
1052 
1053 error:
1054 	return err;
1055 }
1056 EXPORT_SYMBOL(p9_client_remove);
1057 
1058 int
1059 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1060 								u32 count)
1061 {
1062 	int err, rsize, total;
1063 	struct p9_client *clnt;
1064 	struct p9_req_t *req;
1065 	char *dataptr;
1066 
1067 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1068 					(long long unsigned) offset, count);
1069 	err = 0;
1070 	clnt = fid->clnt;
1071 	total = 0;
1072 
1073 	rsize = fid->iounit;
1074 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1075 		rsize = clnt->msize - P9_IOHDRSZ;
1076 
1077 	if (count < rsize)
1078 		rsize = count;
1079 
1080 	req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1081 	if (IS_ERR(req)) {
1082 		err = PTR_ERR(req);
1083 		goto error;
1084 	}
1085 
1086 	err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1087 	if (err) {
1088 		p9pdu_dump(1, req->rc);
1089 		goto free_and_error;
1090 	}
1091 
1092 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1093 
1094 	if (data) {
1095 		memmove(data, dataptr, count);
1096 	}
1097 
1098 	if (udata) {
1099 		err = copy_to_user(udata, dataptr, count);
1100 		if (err) {
1101 			err = -EFAULT;
1102 			goto free_and_error;
1103 		}
1104 	}
1105 
1106 	p9_free_req(clnt, req);
1107 	return count;
1108 
1109 free_and_error:
1110 	p9_free_req(clnt, req);
1111 error:
1112 	return err;
1113 }
1114 EXPORT_SYMBOL(p9_client_read);
1115 
1116 int
1117 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1118 							u64 offset, u32 count)
1119 {
1120 	int err, rsize, total;
1121 	struct p9_client *clnt;
1122 	struct p9_req_t *req;
1123 
1124 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1125 				fid->fid, (long long unsigned) offset, count);
1126 	err = 0;
1127 	clnt = fid->clnt;
1128 	total = 0;
1129 
1130 	rsize = fid->iounit;
1131 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1132 		rsize = clnt->msize - P9_IOHDRSZ;
1133 
1134 	if (count < rsize)
1135 		rsize = count;
1136 	if (data)
1137 		req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1138 								rsize, data);
1139 	else
1140 		req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1141 								rsize, udata);
1142 	if (IS_ERR(req)) {
1143 		err = PTR_ERR(req);
1144 		goto error;
1145 	}
1146 
1147 	err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1148 	if (err) {
1149 		p9pdu_dump(1, req->rc);
1150 		goto free_and_error;
1151 	}
1152 
1153 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1154 
1155 	p9_free_req(clnt, req);
1156 	return count;
1157 
1158 free_and_error:
1159 	p9_free_req(clnt, req);
1160 error:
1161 	return err;
1162 }
1163 EXPORT_SYMBOL(p9_client_write);
1164 
1165 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1166 {
1167 	int err;
1168 	struct p9_client *clnt;
1169 	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1170 	struct p9_req_t *req;
1171 	u16 ignored;
1172 
1173 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1174 
1175 	if (!ret)
1176 		return ERR_PTR(-ENOMEM);
1177 
1178 	err = 0;
1179 	clnt = fid->clnt;
1180 
1181 	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1182 	if (IS_ERR(req)) {
1183 		err = PTR_ERR(req);
1184 		goto error;
1185 	}
1186 
1187 	err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1188 	if (err) {
1189 		p9pdu_dump(1, req->rc);
1190 		p9_free_req(clnt, req);
1191 		goto error;
1192 	}
1193 
1194 	P9_DPRINTK(P9_DEBUG_9P,
1195 		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1196 		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1197 		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1198 		"<<<    uid=%d gid=%d n_muid=%d\n",
1199 		ret->size, ret->type, ret->dev, ret->qid.type,
1200 		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1201 		ret->atime, ret->mtime, (unsigned long long)ret->length,
1202 		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1203 		ret->n_uid, ret->n_gid, ret->n_muid);
1204 
1205 	p9_free_req(clnt, req);
1206 	return ret;
1207 
1208 error:
1209 	kfree(ret);
1210 	return ERR_PTR(err);
1211 }
1212 EXPORT_SYMBOL(p9_client_stat);
1213 
1214 static int p9_client_statsize(struct p9_wstat *wst, int optional)
1215 {
1216 	int ret;
1217 
1218 	/* size[2] type[2] dev[4] qid[13] */
1219 	/* mode[4] atime[4] mtime[4] length[8]*/
1220 	/* name[s] uid[s] gid[s] muid[s] */
1221 	ret = 2+2+4+13+4+4+4+8+2+2+2+2;
1222 
1223 	if (wst->name)
1224 		ret += strlen(wst->name);
1225 	if (wst->uid)
1226 		ret += strlen(wst->uid);
1227 	if (wst->gid)
1228 		ret += strlen(wst->gid);
1229 	if (wst->muid)
1230 		ret += strlen(wst->muid);
1231 
1232 	if (optional) {
1233 		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1234 		if (wst->extension)
1235 			ret += strlen(wst->extension);
1236 	}
1237 
1238 	return ret;
1239 }
1240 
1241 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1242 {
1243 	int err;
1244 	struct p9_req_t *req;
1245 	struct p9_client *clnt;
1246 
1247 	err = 0;
1248 	clnt = fid->clnt;
1249 	wst->size = p9_client_statsize(wst, clnt->dotu);
1250 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1251 	P9_DPRINTK(P9_DEBUG_9P,
1252 		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1253 		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1254 		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1255 		"     uid=%d gid=%d n_muid=%d\n",
1256 		wst->size, wst->type, wst->dev, wst->qid.type,
1257 		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1258 		wst->atime, wst->mtime, (unsigned long long)wst->length,
1259 		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1260 		wst->n_uid, wst->n_gid, wst->n_muid);
1261 
1262 	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size, wst);
1263 	if (IS_ERR(req)) {
1264 		err = PTR_ERR(req);
1265 		goto error;
1266 	}
1267 
1268 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1269 
1270 	p9_free_req(clnt, req);
1271 error:
1272 	return err;
1273 }
1274 EXPORT_SYMBOL(p9_client_wstat);
1275