xref: /openbmc/linux/net/9p/client.c (revision 81d67439)
1 /*
2  * net/9p/clnt.c
3  *
4  * 9P Client
5  *
6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2
11  *  as published by the Free Software Foundation.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to:
20  *  Free Software Foundation
21  *  51 Franklin Street, Fifth Floor
22  *  Boston, MA  02111-1301  USA
23  *
24  */
25 
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/fs.h>
29 #include <linux/poll.h>
30 #include <linux/idr.h>
31 #include <linux/mutex.h>
32 #include <linux/slab.h>
33 #include <linux/sched.h>
34 #include <linux/uaccess.h>
35 #include <net/9p/9p.h>
36 #include <linux/parser.h>
37 #include <net/9p/client.h>
38 #include <net/9p/transport.h>
39 #include "protocol.h"
40 
41 /*
42   * Client Option Parsing (code inspired by NFS code)
43   *  - a little lazy - parse all client options
44   */
45 
46 enum {
47 	Opt_msize,
48 	Opt_trans,
49 	Opt_legacy,
50 	Opt_version,
51 	Opt_err,
52 };
53 
54 static const match_table_t tokens = {
55 	{Opt_msize, "msize=%u"},
56 	{Opt_legacy, "noextend"},
57 	{Opt_trans, "trans=%s"},
58 	{Opt_version, "version=%s"},
59 	{Opt_err, NULL},
60 };
61 
62 inline int p9_is_proto_dotl(struct p9_client *clnt)
63 {
64 	return clnt->proto_version == p9_proto_2000L;
65 }
66 EXPORT_SYMBOL(p9_is_proto_dotl);
67 
68 inline int p9_is_proto_dotu(struct p9_client *clnt)
69 {
70 	return clnt->proto_version == p9_proto_2000u;
71 }
72 EXPORT_SYMBOL(p9_is_proto_dotu);
73 
74 /* Interpret mount option for protocol version */
75 static int get_protocol_version(char *s)
76 {
77 	int version = -EINVAL;
78 
79 	if (!strcmp(s, "9p2000")) {
80 		version = p9_proto_legacy;
81 		P9_DPRINTK(P9_DEBUG_9P, "Protocol version: Legacy\n");
82 	} else if (!strcmp(s, "9p2000.u")) {
83 		version = p9_proto_2000u;
84 		P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
85 	} else if (!strcmp(s, "9p2000.L")) {
86 		version = p9_proto_2000L;
87 		P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
88 	} else
89 		printk(KERN_INFO "9p: Unknown protocol version %s.\n", s);
90 
91 	return version;
92 }
93 
94 /**
95  * parse_options - parse mount options into client structure
96  * @opts: options string passed from mount
97  * @clnt: existing v9fs client information
98  *
99  * Return 0 upon success, -ERRNO upon failure
100  */
101 
102 static int parse_opts(char *opts, struct p9_client *clnt)
103 {
104 	char *options, *tmp_options;
105 	char *p;
106 	substring_t args[MAX_OPT_ARGS];
107 	int option;
108 	char *s;
109 	int ret = 0;
110 
111 	clnt->proto_version = p9_proto_2000u;
112 	clnt->msize = 8192;
113 
114 	if (!opts)
115 		return 0;
116 
117 	tmp_options = kstrdup(opts, GFP_KERNEL);
118 	if (!tmp_options) {
119 		P9_DPRINTK(P9_DEBUG_ERROR,
120 				"failed to allocate copy of option string\n");
121 		return -ENOMEM;
122 	}
123 	options = tmp_options;
124 
125 	while ((p = strsep(&options, ",")) != NULL) {
126 		int token;
127 		if (!*p)
128 			continue;
129 		token = match_token(p, tokens, args);
130 		if (token < Opt_trans) {
131 			int r = match_int(&args[0], &option);
132 			if (r < 0) {
133 				P9_DPRINTK(P9_DEBUG_ERROR,
134 					"integer field, but no integer?\n");
135 				ret = r;
136 				continue;
137 			}
138 		}
139 		switch (token) {
140 		case Opt_msize:
141 			clnt->msize = option;
142 			break;
143 		case Opt_trans:
144 			s = match_strdup(&args[0]);
145 			if (!s) {
146 				ret = -ENOMEM;
147 				P9_DPRINTK(P9_DEBUG_ERROR,
148 					"problem allocating copy of trans arg\n");
149 				goto free_and_return;
150 			 }
151 			clnt->trans_mod = v9fs_get_trans_by_name(s);
152 			if (clnt->trans_mod == NULL) {
153 				printk(KERN_INFO
154 					"9p: Could not find "
155 					"request transport: %s\n", s);
156 				ret = -EINVAL;
157 				kfree(s);
158 				goto free_and_return;
159 			}
160 			kfree(s);
161 			break;
162 		case Opt_legacy:
163 			clnt->proto_version = p9_proto_legacy;
164 			break;
165 		case Opt_version:
166 			s = match_strdup(&args[0]);
167 			if (!s) {
168 				ret = -ENOMEM;
169 				P9_DPRINTK(P9_DEBUG_ERROR,
170 					"problem allocating copy of version arg\n");
171 				goto free_and_return;
172 			}
173 			ret = get_protocol_version(s);
174 			if (ret == -EINVAL) {
175 				kfree(s);
176 				goto free_and_return;
177 			}
178 			kfree(s);
179 			clnt->proto_version = ret;
180 			break;
181 		default:
182 			continue;
183 		}
184 	}
185 
186 free_and_return:
187 	kfree(tmp_options);
188 	return ret;
189 }
190 
191 /**
192  * p9_tag_alloc - lookup/allocate a request by tag
193  * @c: client session to lookup tag within
194  * @tag: numeric id for transaction
195  *
196  * this is a simple array lookup, but will grow the
197  * request_slots as necessary to accommodate transaction
198  * ids which did not previously have a slot.
199  *
200  * this code relies on the client spinlock to manage locks, its
201  * possible we should switch to something else, but I'd rather
202  * stick with something low-overhead for the common case.
203  *
204  */
205 
206 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
207 {
208 	unsigned long flags;
209 	int row, col;
210 	struct p9_req_t *req;
211 
212 	/* This looks up the original request by tag so we know which
213 	 * buffer to read the data into */
214 	tag++;
215 
216 	if (tag >= c->max_tag) {
217 		spin_lock_irqsave(&c->lock, flags);
218 		/* check again since original check was outside of lock */
219 		while (tag >= c->max_tag) {
220 			row = (tag / P9_ROW_MAXTAG);
221 			c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
222 					sizeof(struct p9_req_t), GFP_ATOMIC);
223 
224 			if (!c->reqs[row]) {
225 				printk(KERN_ERR "Couldn't grow tag array\n");
226 				spin_unlock_irqrestore(&c->lock, flags);
227 				return ERR_PTR(-ENOMEM);
228 			}
229 			for (col = 0; col < P9_ROW_MAXTAG; col++) {
230 				c->reqs[row][col].status = REQ_STATUS_IDLE;
231 				c->reqs[row][col].tc = NULL;
232 			}
233 			c->max_tag += P9_ROW_MAXTAG;
234 		}
235 		spin_unlock_irqrestore(&c->lock, flags);
236 	}
237 	row = tag / P9_ROW_MAXTAG;
238 	col = tag % P9_ROW_MAXTAG;
239 
240 	req = &c->reqs[row][col];
241 	if (!req->tc) {
242 		req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
243 		if (!req->wq) {
244 			printk(KERN_ERR "Couldn't grow tag array\n");
245 			return ERR_PTR(-ENOMEM);
246 		}
247 		init_waitqueue_head(req->wq);
248 		if ((c->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
249 				P9_TRANS_PREF_PAYLOAD_SEP) {
250 			int alloc_msize = min(c->msize, 4096);
251 			req->tc = kmalloc(sizeof(struct p9_fcall)+alloc_msize,
252 					  GFP_NOFS);
253 			req->tc->capacity = alloc_msize;
254 			req->rc = kmalloc(sizeof(struct p9_fcall)+alloc_msize,
255 					  GFP_NOFS);
256 			req->rc->capacity = alloc_msize;
257 		} else {
258 			req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
259 					  GFP_NOFS);
260 			req->tc->capacity = c->msize;
261 			req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
262 					  GFP_NOFS);
263 			req->rc->capacity = c->msize;
264 		}
265 		if ((!req->tc) || (!req->rc)) {
266 			printk(KERN_ERR "Couldn't grow tag array\n");
267 			kfree(req->tc);
268 			kfree(req->rc);
269 			kfree(req->wq);
270 			req->tc = req->rc = NULL;
271 			req->wq = NULL;
272 			return ERR_PTR(-ENOMEM);
273 		}
274 		req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
275 		req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
276 	}
277 
278 	p9pdu_reset(req->tc);
279 	p9pdu_reset(req->rc);
280 
281 	req->tc->tag = tag-1;
282 	req->status = REQ_STATUS_ALLOC;
283 
284 	return &c->reqs[row][col];
285 }
286 
287 /**
288  * p9_tag_lookup - lookup a request by tag
289  * @c: client session to lookup tag within
290  * @tag: numeric id for transaction
291  *
292  */
293 
294 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
295 {
296 	int row, col;
297 
298 	/* This looks up the original request by tag so we know which
299 	 * buffer to read the data into */
300 	tag++;
301 
302 	if(tag >= c->max_tag)
303 		return NULL;
304 
305 	row = tag / P9_ROW_MAXTAG;
306 	col = tag % P9_ROW_MAXTAG;
307 
308 	return &c->reqs[row][col];
309 }
310 EXPORT_SYMBOL(p9_tag_lookup);
311 
312 /**
313  * p9_tag_init - setup tags structure and contents
314  * @c:  v9fs client struct
315  *
316  * This initializes the tags structure for each client instance.
317  *
318  */
319 
320 static int p9_tag_init(struct p9_client *c)
321 {
322 	int err = 0;
323 
324 	c->tagpool = p9_idpool_create();
325 	if (IS_ERR(c->tagpool)) {
326 		err = PTR_ERR(c->tagpool);
327 		goto error;
328 	}
329 	err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
330 	if (err < 0) {
331 		p9_idpool_destroy(c->tagpool);
332 		goto error;
333 	}
334 	c->max_tag = 0;
335 error:
336 	return err;
337 }
338 
339 /**
340  * p9_tag_cleanup - cleans up tags structure and reclaims resources
341  * @c:  v9fs client struct
342  *
343  * This frees resources associated with the tags structure
344  *
345  */
346 static void p9_tag_cleanup(struct p9_client *c)
347 {
348 	int row, col;
349 
350 	/* check to insure all requests are idle */
351 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
352 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
353 			if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
354 				P9_DPRINTK(P9_DEBUG_MUX,
355 				  "Attempting to cleanup non-free tag %d,%d\n",
356 				  row, col);
357 				/* TODO: delay execution of cleanup */
358 				return;
359 			}
360 		}
361 	}
362 
363 	if (c->tagpool) {
364 		p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
365 		p9_idpool_destroy(c->tagpool);
366 	}
367 
368 	/* free requests associated with tags */
369 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
370 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
371 			kfree(c->reqs[row][col].wq);
372 			kfree(c->reqs[row][col].tc);
373 			kfree(c->reqs[row][col].rc);
374 		}
375 		kfree(c->reqs[row]);
376 	}
377 	c->max_tag = 0;
378 }
379 
380 /**
381  * p9_free_req - free a request and clean-up as necessary
382  * c: client state
383  * r: request to release
384  *
385  */
386 
387 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
388 {
389 	int tag = r->tc->tag;
390 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
391 
392 	r->status = REQ_STATUS_IDLE;
393 	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
394 		p9_idpool_put(tag, c->tagpool);
395 }
396 
397 /**
398  * p9_client_cb - call back from transport to client
399  * c: client state
400  * req: request received
401  *
402  */
403 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
404 {
405 	P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
406 	wake_up(req->wq);
407 	P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
408 }
409 EXPORT_SYMBOL(p9_client_cb);
410 
411 /**
412  * p9_parse_header - parse header arguments out of a packet
413  * @pdu: packet to parse
414  * @size: size of packet
415  * @type: type of request
416  * @tag: tag of packet
417  * @rewind: set if we need to rewind offset afterwards
418  */
419 
420 int
421 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
422 								int rewind)
423 {
424 	int8_t r_type;
425 	int16_t r_tag;
426 	int32_t r_size;
427 	int offset = pdu->offset;
428 	int err;
429 
430 	pdu->offset = 0;
431 	if (pdu->size == 0)
432 		pdu->size = 7;
433 
434 	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
435 	if (err)
436 		goto rewind_and_exit;
437 
438 	pdu->size = r_size;
439 	pdu->id = r_type;
440 	pdu->tag = r_tag;
441 
442 	P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
443 							pdu->id, pdu->tag);
444 
445 	if (type)
446 		*type = r_type;
447 	if (tag)
448 		*tag = r_tag;
449 	if (size)
450 		*size = r_size;
451 
452 
453 rewind_and_exit:
454 	if (rewind)
455 		pdu->offset = offset;
456 	return err;
457 }
458 EXPORT_SYMBOL(p9_parse_header);
459 
460 /**
461  * p9_check_errors - check 9p packet for error return and process it
462  * @c: current client instance
463  * @req: request to parse and check for error conditions
464  *
465  * returns error code if one is discovered, otherwise returns 0
466  *
467  * this will have to be more complicated if we have multiple
468  * error packet types
469  */
470 
471 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
472 {
473 	int8_t type;
474 	int err;
475 	int ecode;
476 
477 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
478 	if (err) {
479 		P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
480 		return err;
481 	}
482 
483 	if (type != P9_RERROR && type != P9_RLERROR)
484 		return 0;
485 
486 	if (!p9_is_proto_dotl(c)) {
487 		char *ename;
488 
489 		if (req->tc->pbuf_size) {
490 			/* Handle user buffers */
491 			size_t len = req->rc->size - req->rc->offset;
492 			if (req->tc->pubuf) {
493 				/* User Buffer */
494 				err = copy_from_user(
495 					&req->rc->sdata[req->rc->offset],
496 					req->tc->pubuf, len);
497 				if (err) {
498 					err = -EFAULT;
499 					goto out_err;
500 				}
501 			} else {
502 				/* Kernel Buffer */
503 				memmove(&req->rc->sdata[req->rc->offset],
504 						req->tc->pkbuf, len);
505 			}
506 		}
507 		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
508 				&ename, &ecode);
509 		if (err)
510 			goto out_err;
511 
512 		if (p9_is_proto_dotu(c))
513 			err = -ecode;
514 
515 		if (!err || !IS_ERR_VALUE(err)) {
516 			err = p9_errstr2errno(ename, strlen(ename));
517 
518 			P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode,
519 					ename);
520 
521 			kfree(ename);
522 		}
523 	} else {
524 		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
525 		err = -ecode;
526 
527 		P9_DPRINTK(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
528 	}
529 
530 
531 	return err;
532 
533 out_err:
534 	P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
535 
536 	return err;
537 }
538 
539 static struct p9_req_t *
540 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
541 
542 /**
543  * p9_client_flush - flush (cancel) a request
544  * @c: client state
545  * @oldreq: request to cancel
546  *
547  * This sents a flush for a particular request and links
548  * the flush request to the original request.  The current
549  * code only supports a single flush request although the protocol
550  * allows for multiple flush requests to be sent for a single request.
551  *
552  */
553 
554 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
555 {
556 	struct p9_req_t *req;
557 	int16_t oldtag;
558 	int err;
559 
560 	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
561 	if (err)
562 		return err;
563 
564 	P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
565 
566 	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
567 	if (IS_ERR(req))
568 		return PTR_ERR(req);
569 
570 
571 	/* if we haven't received a response for oldreq,
572 	   remove it from the list. */
573 	spin_lock(&c->lock);
574 	if (oldreq->status == REQ_STATUS_FLSH)
575 		list_del(&oldreq->req_list);
576 	spin_unlock(&c->lock);
577 
578 	p9_free_req(c, req);
579 	return 0;
580 }
581 
582 /**
583  * p9_client_rpc - issue a request and wait for a response
584  * @c: client session
585  * @type: type of request
586  * @fmt: protocol format string (see protocol.c)
587  *
588  * Returns request structure (which client must free using p9_free_req)
589  */
590 
591 static struct p9_req_t *
592 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
593 {
594 	va_list ap;
595 	int tag, err;
596 	struct p9_req_t *req;
597 	unsigned long flags;
598 	int sigpending;
599 
600 	P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
601 
602 	/* we allow for any status other than disconnected */
603 	if (c->status == Disconnected)
604 		return ERR_PTR(-EIO);
605 
606 	/* if status is begin_disconnected we allow only clunk request */
607 	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
608 		return ERR_PTR(-EIO);
609 
610 	if (signal_pending(current)) {
611 		sigpending = 1;
612 		clear_thread_flag(TIF_SIGPENDING);
613 	} else
614 		sigpending = 0;
615 
616 	tag = P9_NOTAG;
617 	if (type != P9_TVERSION) {
618 		tag = p9_idpool_get(c->tagpool);
619 		if (tag < 0)
620 			return ERR_PTR(-ENOMEM);
621 	}
622 
623 	req = p9_tag_alloc(c, tag);
624 	if (IS_ERR(req))
625 		return req;
626 
627 	/* marshall the data */
628 	p9pdu_prepare(req->tc, tag, type);
629 	va_start(ap, fmt);
630 	err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
631 	va_end(ap);
632 	if (err)
633 		goto reterr;
634 	p9pdu_finalize(req->tc);
635 
636 	err = c->trans_mod->request(c, req);
637 	if (err < 0) {
638 		if (err != -ERESTARTSYS && err != -EFAULT)
639 			c->status = Disconnected;
640 		goto reterr;
641 	}
642 
643 	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
644 	err = wait_event_interruptible(*req->wq,
645 						req->status >= REQ_STATUS_RCVD);
646 	P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
647 						req->wq, tag, err);
648 
649 	if (req->status == REQ_STATUS_ERROR) {
650 		P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
651 		err = req->t_err;
652 	}
653 
654 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
655 		P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
656 		sigpending = 1;
657 		clear_thread_flag(TIF_SIGPENDING);
658 
659 		if (c->trans_mod->cancel(c, req))
660 			p9_client_flush(c, req);
661 
662 		/* if we received the response anyway, don't signal error */
663 		if (req->status == REQ_STATUS_RCVD)
664 			err = 0;
665 	}
666 
667 	if (sigpending) {
668 		spin_lock_irqsave(&current->sighand->siglock, flags);
669 		recalc_sigpending();
670 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
671 	}
672 
673 	if (err < 0)
674 		goto reterr;
675 
676 	err = p9_check_errors(c, req);
677 	if (!err) {
678 		P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
679 		return req;
680 	}
681 
682 reterr:
683 	P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
684 									err);
685 	p9_free_req(c, req);
686 	return ERR_PTR(err);
687 }
688 
689 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
690 {
691 	int ret;
692 	struct p9_fid *fid;
693 	unsigned long flags;
694 
695 	P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
696 	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
697 	if (!fid)
698 		return ERR_PTR(-ENOMEM);
699 
700 	ret = p9_idpool_get(clnt->fidpool);
701 	if (ret < 0) {
702 		ret = -ENOSPC;
703 		goto error;
704 	}
705 	fid->fid = ret;
706 
707 	memset(&fid->qid, 0, sizeof(struct p9_qid));
708 	fid->mode = -1;
709 	fid->uid = current_fsuid();
710 	fid->clnt = clnt;
711 	fid->rdir = NULL;
712 	spin_lock_irqsave(&clnt->lock, flags);
713 	list_add(&fid->flist, &clnt->fidlist);
714 	spin_unlock_irqrestore(&clnt->lock, flags);
715 
716 	return fid;
717 
718 error:
719 	kfree(fid);
720 	return ERR_PTR(ret);
721 }
722 
723 static void p9_fid_destroy(struct p9_fid *fid)
724 {
725 	struct p9_client *clnt;
726 	unsigned long flags;
727 
728 	P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
729 	clnt = fid->clnt;
730 	p9_idpool_put(fid->fid, clnt->fidpool);
731 	spin_lock_irqsave(&clnt->lock, flags);
732 	list_del(&fid->flist);
733 	spin_unlock_irqrestore(&clnt->lock, flags);
734 	kfree(fid->rdir);
735 	kfree(fid);
736 }
737 
738 static int p9_client_version(struct p9_client *c)
739 {
740 	int err = 0;
741 	struct p9_req_t *req;
742 	char *version;
743 	int msize;
744 
745 	P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
746 						c->msize, c->proto_version);
747 
748 	switch (c->proto_version) {
749 	case p9_proto_2000L:
750 		req = p9_client_rpc(c, P9_TVERSION, "ds",
751 					c->msize, "9P2000.L");
752 		break;
753 	case p9_proto_2000u:
754 		req = p9_client_rpc(c, P9_TVERSION, "ds",
755 					c->msize, "9P2000.u");
756 		break;
757 	case p9_proto_legacy:
758 		req = p9_client_rpc(c, P9_TVERSION, "ds",
759 					c->msize, "9P2000");
760 		break;
761 	default:
762 		return -EINVAL;
763 		break;
764 	}
765 
766 	if (IS_ERR(req))
767 		return PTR_ERR(req);
768 
769 	err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
770 	if (err) {
771 		P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
772 		P9_DUMP_PKT(1, req->rc);
773 		goto error;
774 	}
775 
776 	P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
777 	if (!strncmp(version, "9P2000.L", 8))
778 		c->proto_version = p9_proto_2000L;
779 	else if (!strncmp(version, "9P2000.u", 8))
780 		c->proto_version = p9_proto_2000u;
781 	else if (!strncmp(version, "9P2000", 6))
782 		c->proto_version = p9_proto_legacy;
783 	else {
784 		err = -EREMOTEIO;
785 		goto error;
786 	}
787 
788 	if (msize < c->msize)
789 		c->msize = msize;
790 
791 error:
792 	kfree(version);
793 	p9_free_req(c, req);
794 
795 	return err;
796 }
797 
798 struct p9_client *p9_client_create(const char *dev_name, char *options)
799 {
800 	int err;
801 	struct p9_client *clnt;
802 
803 	err = 0;
804 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
805 	if (!clnt)
806 		return ERR_PTR(-ENOMEM);
807 
808 	clnt->trans_mod = NULL;
809 	clnt->trans = NULL;
810 	spin_lock_init(&clnt->lock);
811 	INIT_LIST_HEAD(&clnt->fidlist);
812 
813 	err = p9_tag_init(clnt);
814 	if (err < 0)
815 		goto free_client;
816 
817 	err = parse_opts(options, clnt);
818 	if (err < 0)
819 		goto destroy_tagpool;
820 
821 	if (!clnt->trans_mod)
822 		clnt->trans_mod = v9fs_get_default_trans();
823 
824 	if (clnt->trans_mod == NULL) {
825 		err = -EPROTONOSUPPORT;
826 		P9_DPRINTK(P9_DEBUG_ERROR,
827 				"No transport defined or default transport\n");
828 		goto destroy_tagpool;
829 	}
830 
831 	clnt->fidpool = p9_idpool_create();
832 	if (IS_ERR(clnt->fidpool)) {
833 		err = PTR_ERR(clnt->fidpool);
834 		goto put_trans;
835 	}
836 
837 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
838 		clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
839 
840 	err = clnt->trans_mod->create(clnt, dev_name, options);
841 	if (err)
842 		goto destroy_fidpool;
843 
844 	if (clnt->msize > clnt->trans_mod->maxsize)
845 		clnt->msize = clnt->trans_mod->maxsize;
846 
847 	err = p9_client_version(clnt);
848 	if (err)
849 		goto close_trans;
850 
851 	return clnt;
852 
853 close_trans:
854 	clnt->trans_mod->close(clnt);
855 destroy_fidpool:
856 	p9_idpool_destroy(clnt->fidpool);
857 put_trans:
858 	v9fs_put_trans(clnt->trans_mod);
859 destroy_tagpool:
860 	p9_idpool_destroy(clnt->tagpool);
861 free_client:
862 	kfree(clnt);
863 	return ERR_PTR(err);
864 }
865 EXPORT_SYMBOL(p9_client_create);
866 
867 void p9_client_destroy(struct p9_client *clnt)
868 {
869 	struct p9_fid *fid, *fidptr;
870 
871 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
872 
873 	if (clnt->trans_mod)
874 		clnt->trans_mod->close(clnt);
875 
876 	v9fs_put_trans(clnt->trans_mod);
877 
878 	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
879 		printk(KERN_INFO "Found fid %d not clunked\n", fid->fid);
880 		p9_fid_destroy(fid);
881 	}
882 
883 	if (clnt->fidpool)
884 		p9_idpool_destroy(clnt->fidpool);
885 
886 	p9_tag_cleanup(clnt);
887 
888 	kfree(clnt);
889 }
890 EXPORT_SYMBOL(p9_client_destroy);
891 
892 void p9_client_disconnect(struct p9_client *clnt)
893 {
894 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
895 	clnt->status = Disconnected;
896 }
897 EXPORT_SYMBOL(p9_client_disconnect);
898 
899 void p9_client_begin_disconnect(struct p9_client *clnt)
900 {
901 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
902 	clnt->status = BeginDisconnect;
903 }
904 EXPORT_SYMBOL(p9_client_begin_disconnect);
905 
906 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
907 	char *uname, u32 n_uname, char *aname)
908 {
909 	int err;
910 	struct p9_req_t *req;
911 	struct p9_fid *fid;
912 	struct p9_qid qid;
913 
914 	P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
915 					afid ? afid->fid : -1, uname, aname);
916 	err = 0;
917 
918 	fid = p9_fid_create(clnt);
919 	if (IS_ERR(fid)) {
920 		err = PTR_ERR(fid);
921 		fid = NULL;
922 		goto error;
923 	}
924 
925 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
926 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
927 	if (IS_ERR(req)) {
928 		err = PTR_ERR(req);
929 		goto error;
930 	}
931 
932 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
933 	if (err) {
934 		P9_DUMP_PKT(1, req->rc);
935 		p9_free_req(clnt, req);
936 		goto error;
937 	}
938 
939 	P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
940 					qid.type,
941 					(unsigned long long)qid.path,
942 					qid.version);
943 
944 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
945 
946 	p9_free_req(clnt, req);
947 	return fid;
948 
949 error:
950 	if (fid)
951 		p9_fid_destroy(fid);
952 	return ERR_PTR(err);
953 }
954 EXPORT_SYMBOL(p9_client_attach);
955 
956 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
957 		char **wnames, int clone)
958 {
959 	int err;
960 	struct p9_client *clnt;
961 	struct p9_fid *fid;
962 	struct p9_qid *wqids;
963 	struct p9_req_t *req;
964 	uint16_t nwqids, count;
965 
966 	err = 0;
967 	wqids = NULL;
968 	clnt = oldfid->clnt;
969 	if (clone) {
970 		fid = p9_fid_create(clnt);
971 		if (IS_ERR(fid)) {
972 			err = PTR_ERR(fid);
973 			fid = NULL;
974 			goto error;
975 		}
976 
977 		fid->uid = oldfid->uid;
978 	} else
979 		fid = oldfid;
980 
981 
982 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
983 		oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
984 
985 	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
986 								nwname, wnames);
987 	if (IS_ERR(req)) {
988 		err = PTR_ERR(req);
989 		goto error;
990 	}
991 
992 	err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
993 	if (err) {
994 		P9_DUMP_PKT(1, req->rc);
995 		p9_free_req(clnt, req);
996 		goto clunk_fid;
997 	}
998 	p9_free_req(clnt, req);
999 
1000 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1001 
1002 	if (nwqids != nwname) {
1003 		err = -ENOENT;
1004 		goto clunk_fid;
1005 	}
1006 
1007 	for (count = 0; count < nwqids; count++)
1008 		P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1009 			count, wqids[count].type,
1010 			(unsigned long long)wqids[count].path,
1011 			wqids[count].version);
1012 
1013 	if (nwname)
1014 		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1015 	else
1016 		fid->qid = oldfid->qid;
1017 
1018 	kfree(wqids);
1019 	return fid;
1020 
1021 clunk_fid:
1022 	kfree(wqids);
1023 	p9_client_clunk(fid);
1024 	fid = NULL;
1025 
1026 error:
1027 	if (fid && (fid != oldfid))
1028 		p9_fid_destroy(fid);
1029 
1030 	return ERR_PTR(err);
1031 }
1032 EXPORT_SYMBOL(p9_client_walk);
1033 
1034 int p9_client_open(struct p9_fid *fid, int mode)
1035 {
1036 	int err;
1037 	struct p9_client *clnt;
1038 	struct p9_req_t *req;
1039 	struct p9_qid qid;
1040 	int iounit;
1041 
1042 	clnt = fid->clnt;
1043 	P9_DPRINTK(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1044 		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1045 	err = 0;
1046 
1047 	if (fid->mode != -1)
1048 		return -EINVAL;
1049 
1050 	if (p9_is_proto_dotl(clnt))
1051 		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1052 	else
1053 		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1054 	if (IS_ERR(req)) {
1055 		err = PTR_ERR(req);
1056 		goto error;
1057 	}
1058 
1059 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1060 	if (err) {
1061 		P9_DUMP_PKT(1, req->rc);
1062 		goto free_and_error;
1063 	}
1064 
1065 	P9_DPRINTK(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1066 		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1067 		(unsigned long long)qid.path, qid.version, iounit);
1068 
1069 	fid->mode = mode;
1070 	fid->iounit = iounit;
1071 
1072 free_and_error:
1073 	p9_free_req(clnt, req);
1074 error:
1075 	return err;
1076 }
1077 EXPORT_SYMBOL(p9_client_open);
1078 
1079 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1080 		gid_t gid, struct p9_qid *qid)
1081 {
1082 	int err = 0;
1083 	struct p9_client *clnt;
1084 	struct p9_req_t *req;
1085 	int iounit;
1086 
1087 	P9_DPRINTK(P9_DEBUG_9P,
1088 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1089 			ofid->fid, name, flags, mode, gid);
1090 	clnt = ofid->clnt;
1091 
1092 	if (ofid->mode != -1)
1093 		return -EINVAL;
1094 
1095 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddd", ofid->fid, name, flags,
1096 			mode, gid);
1097 	if (IS_ERR(req)) {
1098 		err = PTR_ERR(req);
1099 		goto error;
1100 	}
1101 
1102 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1103 	if (err) {
1104 		P9_DUMP_PKT(1, req->rc);
1105 		goto free_and_error;
1106 	}
1107 
1108 	P9_DPRINTK(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1109 			qid->type,
1110 			(unsigned long long)qid->path,
1111 			qid->version, iounit);
1112 
1113 	ofid->mode = mode;
1114 	ofid->iounit = iounit;
1115 
1116 free_and_error:
1117 	p9_free_req(clnt, req);
1118 error:
1119 	return err;
1120 }
1121 EXPORT_SYMBOL(p9_client_create_dotl);
1122 
1123 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1124 		     char *extension)
1125 {
1126 	int err;
1127 	struct p9_client *clnt;
1128 	struct p9_req_t *req;
1129 	struct p9_qid qid;
1130 	int iounit;
1131 
1132 	P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1133 						fid->fid, name, perm, mode);
1134 	err = 0;
1135 	clnt = fid->clnt;
1136 
1137 	if (fid->mode != -1)
1138 		return -EINVAL;
1139 
1140 	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1141 				mode, extension);
1142 	if (IS_ERR(req)) {
1143 		err = PTR_ERR(req);
1144 		goto error;
1145 	}
1146 
1147 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1148 	if (err) {
1149 		P9_DUMP_PKT(1, req->rc);
1150 		goto free_and_error;
1151 	}
1152 
1153 	P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1154 				qid.type,
1155 				(unsigned long long)qid.path,
1156 				qid.version, iounit);
1157 
1158 	fid->mode = mode;
1159 	fid->iounit = iounit;
1160 
1161 free_and_error:
1162 	p9_free_req(clnt, req);
1163 error:
1164 	return err;
1165 }
1166 EXPORT_SYMBOL(p9_client_fcreate);
1167 
1168 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
1169 		struct p9_qid *qid)
1170 {
1171 	int err = 0;
1172 	struct p9_client *clnt;
1173 	struct p9_req_t *req;
1174 
1175 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1176 			dfid->fid, name, symtgt);
1177 	clnt = dfid->clnt;
1178 
1179 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssd", dfid->fid, name, symtgt,
1180 			gid);
1181 	if (IS_ERR(req)) {
1182 		err = PTR_ERR(req);
1183 		goto error;
1184 	}
1185 
1186 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1187 	if (err) {
1188 		P9_DUMP_PKT(1, req->rc);
1189 		goto free_and_error;
1190 	}
1191 
1192 	P9_DPRINTK(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1193 			qid->type, (unsigned long long)qid->path, qid->version);
1194 
1195 free_and_error:
1196 	p9_free_req(clnt, req);
1197 error:
1198 	return err;
1199 }
1200 EXPORT_SYMBOL(p9_client_symlink);
1201 
1202 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1203 {
1204 	struct p9_client *clnt;
1205 	struct p9_req_t *req;
1206 
1207 	P9_DPRINTK(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1208 			dfid->fid, oldfid->fid, newname);
1209 	clnt = dfid->clnt;
1210 	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1211 			newname);
1212 	if (IS_ERR(req))
1213 		return PTR_ERR(req);
1214 
1215 	P9_DPRINTK(P9_DEBUG_9P, "<<< RLINK\n");
1216 	p9_free_req(clnt, req);
1217 	return 0;
1218 }
1219 EXPORT_SYMBOL(p9_client_link);
1220 
1221 int p9_client_fsync(struct p9_fid *fid, int datasync)
1222 {
1223 	int err;
1224 	struct p9_client *clnt;
1225 	struct p9_req_t *req;
1226 
1227 	P9_DPRINTK(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1228 			fid->fid, datasync);
1229 	err = 0;
1230 	clnt = fid->clnt;
1231 
1232 	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1233 	if (IS_ERR(req)) {
1234 		err = PTR_ERR(req);
1235 		goto error;
1236 	}
1237 
1238 	P9_DPRINTK(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1239 
1240 	p9_free_req(clnt, req);
1241 
1242 error:
1243 	return err;
1244 }
1245 EXPORT_SYMBOL(p9_client_fsync);
1246 
1247 int p9_client_clunk(struct p9_fid *fid)
1248 {
1249 	int err;
1250 	struct p9_client *clnt;
1251 	struct p9_req_t *req;
1252 
1253 	if (!fid) {
1254 		P9_EPRINTK(KERN_WARNING, "Trying to clunk with NULL fid\n");
1255 		dump_stack();
1256 		return 0;
1257 	}
1258 
1259 	P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1260 	err = 0;
1261 	clnt = fid->clnt;
1262 
1263 	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1264 	if (IS_ERR(req)) {
1265 		err = PTR_ERR(req);
1266 		goto error;
1267 	}
1268 
1269 	P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1270 
1271 	p9_free_req(clnt, req);
1272 error:
1273 	/*
1274 	 * Fid is not valid even after a failed clunk
1275 	 */
1276 	p9_fid_destroy(fid);
1277 	return err;
1278 }
1279 EXPORT_SYMBOL(p9_client_clunk);
1280 
1281 int p9_client_remove(struct p9_fid *fid)
1282 {
1283 	int err;
1284 	struct p9_client *clnt;
1285 	struct p9_req_t *req;
1286 
1287 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1288 	err = 0;
1289 	clnt = fid->clnt;
1290 
1291 	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1292 	if (IS_ERR(req)) {
1293 		err = PTR_ERR(req);
1294 		goto error;
1295 	}
1296 
1297 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1298 
1299 	p9_free_req(clnt, req);
1300 error:
1301 	p9_fid_destroy(fid);
1302 	return err;
1303 }
1304 EXPORT_SYMBOL(p9_client_remove);
1305 
1306 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1307 {
1308 	int err = 0;
1309 	struct p9_req_t *req;
1310 	struct p9_client *clnt;
1311 
1312 	P9_DPRINTK(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1313 		   dfid->fid, name, flags);
1314 
1315 	clnt = dfid->clnt;
1316 	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1317 	if (IS_ERR(req)) {
1318 		err = PTR_ERR(req);
1319 		goto error;
1320 	}
1321 	P9_DPRINTK(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1322 
1323 	p9_free_req(clnt, req);
1324 error:
1325 	return err;
1326 }
1327 EXPORT_SYMBOL(p9_client_unlinkat);
1328 
1329 int
1330 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1331 								u32 count)
1332 {
1333 	int err, rsize;
1334 	struct p9_client *clnt;
1335 	struct p9_req_t *req;
1336 	char *dataptr;
1337 
1338 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1339 					(long long unsigned) offset, count);
1340 	err = 0;
1341 	clnt = fid->clnt;
1342 
1343 	rsize = fid->iounit;
1344 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1345 		rsize = clnt->msize - P9_IOHDRSZ;
1346 
1347 	if (count < rsize)
1348 		rsize = count;
1349 
1350 	/* Don't bother zerocopy for small IO (< 1024) */
1351 	if (((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
1352 			P9_TRANS_PREF_PAYLOAD_SEP) && (rsize > 1024)) {
1353 		req = p9_client_rpc(clnt, P9_TREAD, "dqE", fid->fid, offset,
1354 				rsize, data, udata);
1355 	} else {
1356 		req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1357 				rsize);
1358 	}
1359 	if (IS_ERR(req)) {
1360 		err = PTR_ERR(req);
1361 		goto error;
1362 	}
1363 
1364 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1365 	if (err) {
1366 		P9_DUMP_PKT(1, req->rc);
1367 		goto free_and_error;
1368 	}
1369 
1370 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1371 	P9_DUMP_PKT(1, req->rc);
1372 
1373 	if (!req->tc->pbuf_size) {
1374 		if (data) {
1375 			memmove(data, dataptr, count);
1376 		} else {
1377 			err = copy_to_user(udata, dataptr, count);
1378 			if (err) {
1379 				err = -EFAULT;
1380 				goto free_and_error;
1381 			}
1382 		}
1383 	}
1384 	p9_free_req(clnt, req);
1385 	return count;
1386 
1387 free_and_error:
1388 	p9_free_req(clnt, req);
1389 error:
1390 	return err;
1391 }
1392 EXPORT_SYMBOL(p9_client_read);
1393 
1394 int
1395 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1396 							u64 offset, u32 count)
1397 {
1398 	int err, rsize;
1399 	struct p9_client *clnt;
1400 	struct p9_req_t *req;
1401 
1402 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1403 				fid->fid, (long long unsigned) offset, count);
1404 	err = 0;
1405 	clnt = fid->clnt;
1406 
1407 	rsize = fid->iounit;
1408 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1409 		rsize = clnt->msize - P9_IOHDRSZ;
1410 
1411 	if (count < rsize)
1412 		rsize = count;
1413 
1414 	/* Don't bother zerocopy form small IO (< 1024) */
1415 	if (((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
1416 				P9_TRANS_PREF_PAYLOAD_SEP) && (rsize > 1024)) {
1417 		req = p9_client_rpc(clnt, P9_TWRITE, "dqE", fid->fid, offset,
1418 				rsize, data, udata);
1419 	} else {
1420 
1421 		if (data)
1422 			req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1423 					offset, rsize, data);
1424 		else
1425 			req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1426 					offset, rsize, udata);
1427 	}
1428 	if (IS_ERR(req)) {
1429 		err = PTR_ERR(req);
1430 		goto error;
1431 	}
1432 
1433 	err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1434 	if (err) {
1435 		P9_DUMP_PKT(1, req->rc);
1436 		goto free_and_error;
1437 	}
1438 
1439 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1440 
1441 	p9_free_req(clnt, req);
1442 	return count;
1443 
1444 free_and_error:
1445 	p9_free_req(clnt, req);
1446 error:
1447 	return err;
1448 }
1449 EXPORT_SYMBOL(p9_client_write);
1450 
1451 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1452 {
1453 	int err;
1454 	struct p9_client *clnt;
1455 	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1456 	struct p9_req_t *req;
1457 	u16 ignored;
1458 
1459 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1460 
1461 	if (!ret)
1462 		return ERR_PTR(-ENOMEM);
1463 
1464 	err = 0;
1465 	clnt = fid->clnt;
1466 
1467 	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1468 	if (IS_ERR(req)) {
1469 		err = PTR_ERR(req);
1470 		goto error;
1471 	}
1472 
1473 	err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1474 	if (err) {
1475 		P9_DUMP_PKT(1, req->rc);
1476 		p9_free_req(clnt, req);
1477 		goto error;
1478 	}
1479 
1480 	P9_DPRINTK(P9_DEBUG_9P,
1481 		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1482 		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1483 		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1484 		"<<<    uid=%d gid=%d n_muid=%d\n",
1485 		ret->size, ret->type, ret->dev, ret->qid.type,
1486 		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1487 		ret->atime, ret->mtime, (unsigned long long)ret->length,
1488 		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1489 		ret->n_uid, ret->n_gid, ret->n_muid);
1490 
1491 	p9_free_req(clnt, req);
1492 	return ret;
1493 
1494 error:
1495 	kfree(ret);
1496 	return ERR_PTR(err);
1497 }
1498 EXPORT_SYMBOL(p9_client_stat);
1499 
1500 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1501 							u64 request_mask)
1502 {
1503 	int err;
1504 	struct p9_client *clnt;
1505 	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1506 								GFP_KERNEL);
1507 	struct p9_req_t *req;
1508 
1509 	P9_DPRINTK(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1510 							fid->fid, request_mask);
1511 
1512 	if (!ret)
1513 		return ERR_PTR(-ENOMEM);
1514 
1515 	err = 0;
1516 	clnt = fid->clnt;
1517 
1518 	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1519 	if (IS_ERR(req)) {
1520 		err = PTR_ERR(req);
1521 		goto error;
1522 	}
1523 
1524 	err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1525 	if (err) {
1526 		P9_DUMP_PKT(1, req->rc);
1527 		p9_free_req(clnt, req);
1528 		goto error;
1529 	}
1530 
1531 	P9_DPRINTK(P9_DEBUG_9P,
1532 		"<<< RGETATTR st_result_mask=%lld\n"
1533 		"<<< qid=%x.%llx.%x\n"
1534 		"<<< st_mode=%8.8x st_nlink=%llu\n"
1535 		"<<< st_uid=%d st_gid=%d\n"
1536 		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1537 		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1538 		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1539 		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1540 		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1541 		"<<< st_gen=%lld st_data_version=%lld",
1542 		ret->st_result_mask, ret->qid.type, ret->qid.path,
1543 		ret->qid.version, ret->st_mode, ret->st_nlink, ret->st_uid,
1544 		ret->st_gid, ret->st_rdev, ret->st_size, ret->st_blksize,
1545 		ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1546 		ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1547 		ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1548 		ret->st_gen, ret->st_data_version);
1549 
1550 	p9_free_req(clnt, req);
1551 	return ret;
1552 
1553 error:
1554 	kfree(ret);
1555 	return ERR_PTR(err);
1556 }
1557 EXPORT_SYMBOL(p9_client_getattr_dotl);
1558 
1559 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1560 {
1561 	int ret;
1562 
1563 	/* NOTE: size shouldn't include its own length */
1564 	/* size[2] type[2] dev[4] qid[13] */
1565 	/* mode[4] atime[4] mtime[4] length[8]*/
1566 	/* name[s] uid[s] gid[s] muid[s] */
1567 	ret = 2+4+13+4+4+4+8+2+2+2+2;
1568 
1569 	if (wst->name)
1570 		ret += strlen(wst->name);
1571 	if (wst->uid)
1572 		ret += strlen(wst->uid);
1573 	if (wst->gid)
1574 		ret += strlen(wst->gid);
1575 	if (wst->muid)
1576 		ret += strlen(wst->muid);
1577 
1578 	if ((proto_version == p9_proto_2000u) ||
1579 		(proto_version == p9_proto_2000L)) {
1580 		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1581 		if (wst->extension)
1582 			ret += strlen(wst->extension);
1583 	}
1584 
1585 	return ret;
1586 }
1587 
1588 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1589 {
1590 	int err;
1591 	struct p9_req_t *req;
1592 	struct p9_client *clnt;
1593 
1594 	err = 0;
1595 	clnt = fid->clnt;
1596 	wst->size = p9_client_statsize(wst, clnt->proto_version);
1597 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1598 	P9_DPRINTK(P9_DEBUG_9P,
1599 		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1600 		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1601 		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1602 		"     uid=%d gid=%d n_muid=%d\n",
1603 		wst->size, wst->type, wst->dev, wst->qid.type,
1604 		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1605 		wst->atime, wst->mtime, (unsigned long long)wst->length,
1606 		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1607 		wst->n_uid, wst->n_gid, wst->n_muid);
1608 
1609 	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1610 	if (IS_ERR(req)) {
1611 		err = PTR_ERR(req);
1612 		goto error;
1613 	}
1614 
1615 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1616 
1617 	p9_free_req(clnt, req);
1618 error:
1619 	return err;
1620 }
1621 EXPORT_SYMBOL(p9_client_wstat);
1622 
1623 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1624 {
1625 	int err;
1626 	struct p9_req_t *req;
1627 	struct p9_client *clnt;
1628 
1629 	err = 0;
1630 	clnt = fid->clnt;
1631 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1632 	P9_DPRINTK(P9_DEBUG_9P,
1633 		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1634 		"    atime_sec=%lld atime_nsec=%lld\n"
1635 		"    mtime_sec=%lld mtime_nsec=%lld\n",
1636 		p9attr->valid, p9attr->mode, p9attr->uid, p9attr->gid,
1637 		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1638 		p9attr->mtime_sec, p9attr->mtime_nsec);
1639 
1640 	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1641 
1642 	if (IS_ERR(req)) {
1643 		err = PTR_ERR(req);
1644 		goto error;
1645 	}
1646 	P9_DPRINTK(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1647 	p9_free_req(clnt, req);
1648 error:
1649 	return err;
1650 }
1651 EXPORT_SYMBOL(p9_client_setattr);
1652 
1653 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1654 {
1655 	int err;
1656 	struct p9_req_t *req;
1657 	struct p9_client *clnt;
1658 
1659 	err = 0;
1660 	clnt = fid->clnt;
1661 
1662 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1663 
1664 	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1665 	if (IS_ERR(req)) {
1666 		err = PTR_ERR(req);
1667 		goto error;
1668 	}
1669 
1670 	err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1671 		&sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1672 		&sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1673 	if (err) {
1674 		P9_DUMP_PKT(1, req->rc);
1675 		p9_free_req(clnt, req);
1676 		goto error;
1677 	}
1678 
1679 	P9_DPRINTK(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1680 		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1681 		"fsid %llu namelen %ld\n",
1682 		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1683 		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1684 		sb->fsid, (long int)sb->namelen);
1685 
1686 	p9_free_req(clnt, req);
1687 error:
1688 	return err;
1689 }
1690 EXPORT_SYMBOL(p9_client_statfs);
1691 
1692 int p9_client_rename(struct p9_fid *fid,
1693 		     struct p9_fid *newdirfid, const char *name)
1694 {
1695 	int err;
1696 	struct p9_req_t *req;
1697 	struct p9_client *clnt;
1698 
1699 	err = 0;
1700 	clnt = fid->clnt;
1701 
1702 	P9_DPRINTK(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1703 			fid->fid, newdirfid->fid, name);
1704 
1705 	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1706 			newdirfid->fid, name);
1707 	if (IS_ERR(req)) {
1708 		err = PTR_ERR(req);
1709 		goto error;
1710 	}
1711 
1712 	P9_DPRINTK(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1713 
1714 	p9_free_req(clnt, req);
1715 error:
1716 	return err;
1717 }
1718 EXPORT_SYMBOL(p9_client_rename);
1719 
1720 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1721 		       struct p9_fid *newdirfid, const char *new_name)
1722 {
1723 	int err;
1724 	struct p9_req_t *req;
1725 	struct p9_client *clnt;
1726 
1727 	err = 0;
1728 	clnt = olddirfid->clnt;
1729 
1730 	P9_DPRINTK(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1731 		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1732 		   newdirfid->fid, new_name);
1733 
1734 	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1735 			    old_name, newdirfid->fid, new_name);
1736 	if (IS_ERR(req)) {
1737 		err = PTR_ERR(req);
1738 		goto error;
1739 	}
1740 
1741 	P9_DPRINTK(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1742 		   newdirfid->fid, new_name);
1743 
1744 	p9_free_req(clnt, req);
1745 error:
1746 	return err;
1747 }
1748 EXPORT_SYMBOL(p9_client_renameat);
1749 
1750 /*
1751  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1752  */
1753 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1754 				const char *attr_name, u64 *attr_size)
1755 {
1756 	int err;
1757 	struct p9_req_t *req;
1758 	struct p9_client *clnt;
1759 	struct p9_fid *attr_fid;
1760 
1761 	err = 0;
1762 	clnt = file_fid->clnt;
1763 	attr_fid = p9_fid_create(clnt);
1764 	if (IS_ERR(attr_fid)) {
1765 		err = PTR_ERR(attr_fid);
1766 		attr_fid = NULL;
1767 		goto error;
1768 	}
1769 	P9_DPRINTK(P9_DEBUG_9P,
1770 		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1771 		file_fid->fid, attr_fid->fid, attr_name);
1772 
1773 	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1774 			file_fid->fid, attr_fid->fid, attr_name);
1775 	if (IS_ERR(req)) {
1776 		err = PTR_ERR(req);
1777 		goto error;
1778 	}
1779 	err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
1780 	if (err) {
1781 		P9_DUMP_PKT(1, req->rc);
1782 		p9_free_req(clnt, req);
1783 		goto clunk_fid;
1784 	}
1785 	p9_free_req(clnt, req);
1786 	P9_DPRINTK(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
1787 		attr_fid->fid, *attr_size);
1788 	return attr_fid;
1789 clunk_fid:
1790 	p9_client_clunk(attr_fid);
1791 	attr_fid = NULL;
1792 error:
1793 	if (attr_fid && (attr_fid != file_fid))
1794 		p9_fid_destroy(attr_fid);
1795 
1796 	return ERR_PTR(err);
1797 }
1798 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
1799 
1800 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
1801 			u64 attr_size, int flags)
1802 {
1803 	int err;
1804 	struct p9_req_t *req;
1805 	struct p9_client *clnt;
1806 
1807 	P9_DPRINTK(P9_DEBUG_9P,
1808 		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
1809 		fid->fid, name, (long long)attr_size, flags);
1810 	err = 0;
1811 	clnt = fid->clnt;
1812 	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
1813 			fid->fid, name, attr_size, flags);
1814 	if (IS_ERR(req)) {
1815 		err = PTR_ERR(req);
1816 		goto error;
1817 	}
1818 	P9_DPRINTK(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
1819 	p9_free_req(clnt, req);
1820 error:
1821 	return err;
1822 }
1823 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
1824 
1825 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
1826 {
1827 	int err, rsize;
1828 	struct p9_client *clnt;
1829 	struct p9_req_t *req;
1830 	char *dataptr;
1831 
1832 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
1833 				fid->fid, (long long unsigned) offset, count);
1834 
1835 	err = 0;
1836 	clnt = fid->clnt;
1837 
1838 	rsize = fid->iounit;
1839 	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
1840 		rsize = clnt->msize - P9_READDIRHDRSZ;
1841 
1842 	if (count < rsize)
1843 		rsize = count;
1844 
1845 	if ((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
1846 			P9_TRANS_PREF_PAYLOAD_SEP) {
1847 		req = p9_client_rpc(clnt, P9_TREADDIR, "dqF", fid->fid,
1848 				offset, rsize, data);
1849 	} else {
1850 		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
1851 				offset, rsize);
1852 	}
1853 	if (IS_ERR(req)) {
1854 		err = PTR_ERR(req);
1855 		goto error;
1856 	}
1857 
1858 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1859 	if (err) {
1860 		P9_DUMP_PKT(1, req->rc);
1861 		goto free_and_error;
1862 	}
1863 
1864 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
1865 
1866 	if (!req->tc->pbuf_size && data)
1867 		memmove(data, dataptr, count);
1868 
1869 	p9_free_req(clnt, req);
1870 	return count;
1871 
1872 free_and_error:
1873 	p9_free_req(clnt, req);
1874 error:
1875 	return err;
1876 }
1877 EXPORT_SYMBOL(p9_client_readdir);
1878 
1879 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
1880 			dev_t rdev, gid_t gid, struct p9_qid *qid)
1881 {
1882 	int err;
1883 	struct p9_client *clnt;
1884 	struct p9_req_t *req;
1885 
1886 	err = 0;
1887 	clnt = fid->clnt;
1888 	P9_DPRINTK(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
1889 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
1890 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddd", fid->fid, name, mode,
1891 		MAJOR(rdev), MINOR(rdev), gid);
1892 	if (IS_ERR(req))
1893 		return PTR_ERR(req);
1894 
1895 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1896 	if (err) {
1897 		P9_DUMP_PKT(1, req->rc);
1898 		goto error;
1899 	}
1900 	P9_DPRINTK(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
1901 				(unsigned long long)qid->path, qid->version);
1902 
1903 error:
1904 	p9_free_req(clnt, req);
1905 	return err;
1906 
1907 }
1908 EXPORT_SYMBOL(p9_client_mknod_dotl);
1909 
1910 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
1911 				gid_t gid, struct p9_qid *qid)
1912 {
1913 	int err;
1914 	struct p9_client *clnt;
1915 	struct p9_req_t *req;
1916 
1917 	err = 0;
1918 	clnt = fid->clnt;
1919 	P9_DPRINTK(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
1920 		 fid->fid, name, mode, gid);
1921 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdd", fid->fid, name, mode,
1922 		gid);
1923 	if (IS_ERR(req))
1924 		return PTR_ERR(req);
1925 
1926 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1927 	if (err) {
1928 		P9_DUMP_PKT(1, req->rc);
1929 		goto error;
1930 	}
1931 	P9_DPRINTK(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
1932 				(unsigned long long)qid->path, qid->version);
1933 
1934 error:
1935 	p9_free_req(clnt, req);
1936 	return err;
1937 
1938 }
1939 EXPORT_SYMBOL(p9_client_mkdir_dotl);
1940 
1941 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
1942 {
1943 	int err;
1944 	struct p9_client *clnt;
1945 	struct p9_req_t *req;
1946 
1947 	err = 0;
1948 	clnt = fid->clnt;
1949 	P9_DPRINTK(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
1950 			"start %lld length %lld proc_id %d client_id %s\n",
1951 			fid->fid, flock->type, flock->flags, flock->start,
1952 			flock->length, flock->proc_id, flock->client_id);
1953 
1954 	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
1955 				flock->flags, flock->start, flock->length,
1956 					flock->proc_id, flock->client_id);
1957 
1958 	if (IS_ERR(req))
1959 		return PTR_ERR(req);
1960 
1961 	err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
1962 	if (err) {
1963 		P9_DUMP_PKT(1, req->rc);
1964 		goto error;
1965 	}
1966 	P9_DPRINTK(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
1967 error:
1968 	p9_free_req(clnt, req);
1969 	return err;
1970 
1971 }
1972 EXPORT_SYMBOL(p9_client_lock_dotl);
1973 
1974 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
1975 {
1976 	int err;
1977 	struct p9_client *clnt;
1978 	struct p9_req_t *req;
1979 
1980 	err = 0;
1981 	clnt = fid->clnt;
1982 	P9_DPRINTK(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
1983 		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
1984 		glock->start, glock->length, glock->proc_id, glock->client_id);
1985 
1986 	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
1987 		glock->start, glock->length, glock->proc_id, glock->client_id);
1988 
1989 	if (IS_ERR(req))
1990 		return PTR_ERR(req);
1991 
1992 	err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
1993 			&glock->start, &glock->length, &glock->proc_id,
1994 			&glock->client_id);
1995 	if (err) {
1996 		P9_DUMP_PKT(1, req->rc);
1997 		goto error;
1998 	}
1999 	P9_DPRINTK(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2000 		"proc_id %d client_id %s\n", glock->type, glock->start,
2001 		glock->length, glock->proc_id, glock->client_id);
2002 error:
2003 	p9_free_req(clnt, req);
2004 	return err;
2005 }
2006 EXPORT_SYMBOL(p9_client_getlock_dotl);
2007 
2008 int p9_client_readlink(struct p9_fid *fid, char **target)
2009 {
2010 	int err;
2011 	struct p9_client *clnt;
2012 	struct p9_req_t *req;
2013 
2014 	err = 0;
2015 	clnt = fid->clnt;
2016 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2017 
2018 	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2019 	if (IS_ERR(req))
2020 		return PTR_ERR(req);
2021 
2022 	err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2023 	if (err) {
2024 		P9_DUMP_PKT(1, req->rc);
2025 		goto error;
2026 	}
2027 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2028 error:
2029 	p9_free_req(clnt, req);
2030 	return err;
2031 }
2032 EXPORT_SYMBOL(p9_client_readlink);
2033