xref: /linux/net/9p/client.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27 
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/fs.h>
31 #include <linux/poll.h>
32 #include <linux/idr.h>
33 #include <linux/mutex.h>
34 #include <linux/slab.h>
35 #include <linux/sched.h>
36 #include <linux/uaccess.h>
37 #include <net/9p/9p.h>
38 #include <linux/parser.h>
39 #include <net/9p/client.h>
40 #include <net/9p/transport.h>
41 #include "protocol.h"
42 
43 #define CREATE_TRACE_POINTS
44 #include <trace/events/9p.h>
45 
46 /*
47   * Client Option Parsing (code inspired by NFS code)
48   *  - a little lazy - parse all client options
49   */
50 
51 enum {
52 	Opt_msize,
53 	Opt_trans,
54 	Opt_legacy,
55 	Opt_version,
56 	Opt_err,
57 };
58 
59 static const match_table_t tokens = {
60 	{Opt_msize, "msize=%u"},
61 	{Opt_legacy, "noextend"},
62 	{Opt_trans, "trans=%s"},
63 	{Opt_version, "version=%s"},
64 	{Opt_err, NULL},
65 };
66 
67 inline int p9_is_proto_dotl(struct p9_client *clnt)
68 {
69 	return clnt->proto_version == p9_proto_2000L;
70 }
71 EXPORT_SYMBOL(p9_is_proto_dotl);
72 
73 inline int p9_is_proto_dotu(struct p9_client *clnt)
74 {
75 	return clnt->proto_version == p9_proto_2000u;
76 }
77 EXPORT_SYMBOL(p9_is_proto_dotu);
78 
79 /*
80  * Some error codes are taken directly from the server replies,
81  * make sure they are valid.
82  */
83 static int safe_errno(int err)
84 {
85 	if ((err > 0) || (err < -MAX_ERRNO)) {
86 		p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
87 		return -EPROTO;
88 	}
89 	return err;
90 }
91 
92 
93 /* Interpret mount option for protocol version */
94 static int get_protocol_version(char *s)
95 {
96 	int version = -EINVAL;
97 
98 	if (!strcmp(s, "9p2000")) {
99 		version = p9_proto_legacy;
100 		p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
101 	} else if (!strcmp(s, "9p2000.u")) {
102 		version = p9_proto_2000u;
103 		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
104 	} else if (!strcmp(s, "9p2000.L")) {
105 		version = p9_proto_2000L;
106 		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
107 	} else
108 		pr_info("Unknown protocol version %s\n", s);
109 
110 	return version;
111 }
112 
113 /**
114  * parse_options - parse mount options into client structure
115  * @opts: options string passed from mount
116  * @clnt: existing v9fs client information
117  *
118  * Return 0 upon success, -ERRNO upon failure
119  */
120 
121 static int parse_opts(char *opts, struct p9_client *clnt)
122 {
123 	char *options, *tmp_options;
124 	char *p;
125 	substring_t args[MAX_OPT_ARGS];
126 	int option;
127 	char *s;
128 	int ret = 0;
129 
130 	clnt->proto_version = p9_proto_2000u;
131 	clnt->msize = 8192;
132 
133 	if (!opts)
134 		return 0;
135 
136 	tmp_options = kstrdup(opts, GFP_KERNEL);
137 	if (!tmp_options) {
138 		p9_debug(P9_DEBUG_ERROR,
139 			 "failed to allocate copy of option string\n");
140 		return -ENOMEM;
141 	}
142 	options = tmp_options;
143 
144 	while ((p = strsep(&options, ",")) != NULL) {
145 		int token, r;
146 		if (!*p)
147 			continue;
148 		token = match_token(p, tokens, args);
149 		switch (token) {
150 		case Opt_msize:
151 			r = match_int(&args[0], &option);
152 			if (r < 0) {
153 				p9_debug(P9_DEBUG_ERROR,
154 					 "integer field, but no integer?\n");
155 				ret = r;
156 				continue;
157 			}
158 			clnt->msize = option;
159 			break;
160 		case Opt_trans:
161 			s = match_strdup(&args[0]);
162 			if (!s) {
163 				ret = -ENOMEM;
164 				p9_debug(P9_DEBUG_ERROR,
165 					 "problem allocating copy of trans arg\n");
166 				goto free_and_return;
167 			 }
168 			clnt->trans_mod = v9fs_get_trans_by_name(s);
169 			if (clnt->trans_mod == NULL) {
170 				pr_info("Could not find request transport: %s\n",
171 					s);
172 				ret = -EINVAL;
173 				kfree(s);
174 				goto free_and_return;
175 			}
176 			kfree(s);
177 			break;
178 		case Opt_legacy:
179 			clnt->proto_version = p9_proto_legacy;
180 			break;
181 		case Opt_version:
182 			s = match_strdup(&args[0]);
183 			if (!s) {
184 				ret = -ENOMEM;
185 				p9_debug(P9_DEBUG_ERROR,
186 					 "problem allocating copy of version arg\n");
187 				goto free_and_return;
188 			}
189 			ret = get_protocol_version(s);
190 			if (ret == -EINVAL) {
191 				kfree(s);
192 				goto free_and_return;
193 			}
194 			kfree(s);
195 			clnt->proto_version = ret;
196 			break;
197 		default:
198 			continue;
199 		}
200 	}
201 
202 free_and_return:
203 	kfree(tmp_options);
204 	return ret;
205 }
206 
207 /**
208  * p9_tag_alloc - lookup/allocate a request by tag
209  * @c: client session to lookup tag within
210  * @tag: numeric id for transaction
211  *
212  * this is a simple array lookup, but will grow the
213  * request_slots as necessary to accommodate transaction
214  * ids which did not previously have a slot.
215  *
216  * this code relies on the client spinlock to manage locks, its
217  * possible we should switch to something else, but I'd rather
218  * stick with something low-overhead for the common case.
219  *
220  */
221 
222 static struct p9_req_t *
223 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
224 {
225 	unsigned long flags;
226 	int row, col;
227 	struct p9_req_t *req;
228 	int alloc_msize = min(c->msize, max_size);
229 
230 	/* This looks up the original request by tag so we know which
231 	 * buffer to read the data into */
232 	tag++;
233 
234 	if (tag >= c->max_tag) {
235 		spin_lock_irqsave(&c->lock, flags);
236 		/* check again since original check was outside of lock */
237 		while (tag >= c->max_tag) {
238 			row = (tag / P9_ROW_MAXTAG);
239 			c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
240 					sizeof(struct p9_req_t), GFP_ATOMIC);
241 
242 			if (!c->reqs[row]) {
243 				pr_err("Couldn't grow tag array\n");
244 				spin_unlock_irqrestore(&c->lock, flags);
245 				return ERR_PTR(-ENOMEM);
246 			}
247 			for (col = 0; col < P9_ROW_MAXTAG; col++) {
248 				c->reqs[row][col].status = REQ_STATUS_IDLE;
249 				c->reqs[row][col].tc = NULL;
250 			}
251 			c->max_tag += P9_ROW_MAXTAG;
252 		}
253 		spin_unlock_irqrestore(&c->lock, flags);
254 	}
255 	row = tag / P9_ROW_MAXTAG;
256 	col = tag % P9_ROW_MAXTAG;
257 
258 	req = &c->reqs[row][col];
259 	if (!req->tc) {
260 		req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
261 		if (!req->wq) {
262 			pr_err("Couldn't grow tag array\n");
263 			return ERR_PTR(-ENOMEM);
264 		}
265 		init_waitqueue_head(req->wq);
266 		req->tc = kmalloc(sizeof(struct p9_fcall) + alloc_msize,
267 				  GFP_NOFS);
268 		req->rc = kmalloc(sizeof(struct p9_fcall) + alloc_msize,
269 				  GFP_NOFS);
270 		if ((!req->tc) || (!req->rc)) {
271 			pr_err("Couldn't grow tag array\n");
272 			kfree(req->tc);
273 			kfree(req->rc);
274 			kfree(req->wq);
275 			req->tc = req->rc = NULL;
276 			req->wq = NULL;
277 			return ERR_PTR(-ENOMEM);
278 		}
279 		req->tc->capacity = alloc_msize;
280 		req->rc->capacity = alloc_msize;
281 		req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
282 		req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
283 	}
284 
285 	p9pdu_reset(req->tc);
286 	p9pdu_reset(req->rc);
287 
288 	req->tc->tag = tag-1;
289 	req->status = REQ_STATUS_ALLOC;
290 
291 	return &c->reqs[row][col];
292 }
293 
294 /**
295  * p9_tag_lookup - lookup a request by tag
296  * @c: client session to lookup tag within
297  * @tag: numeric id for transaction
298  *
299  */
300 
301 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
302 {
303 	int row, col;
304 
305 	/* This looks up the original request by tag so we know which
306 	 * buffer to read the data into */
307 	tag++;
308 
309 	if(tag >= c->max_tag)
310 		return NULL;
311 
312 	row = tag / P9_ROW_MAXTAG;
313 	col = tag % P9_ROW_MAXTAG;
314 
315 	return &c->reqs[row][col];
316 }
317 EXPORT_SYMBOL(p9_tag_lookup);
318 
319 /**
320  * p9_tag_init - setup tags structure and contents
321  * @c:  v9fs client struct
322  *
323  * This initializes the tags structure for each client instance.
324  *
325  */
326 
327 static int p9_tag_init(struct p9_client *c)
328 {
329 	int err = 0;
330 
331 	c->tagpool = p9_idpool_create();
332 	if (IS_ERR(c->tagpool)) {
333 		err = PTR_ERR(c->tagpool);
334 		goto error;
335 	}
336 	err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
337 	if (err < 0) {
338 		p9_idpool_destroy(c->tagpool);
339 		goto error;
340 	}
341 	c->max_tag = 0;
342 error:
343 	return err;
344 }
345 
346 /**
347  * p9_tag_cleanup - cleans up tags structure and reclaims resources
348  * @c:  v9fs client struct
349  *
350  * This frees resources associated with the tags structure
351  *
352  */
353 static void p9_tag_cleanup(struct p9_client *c)
354 {
355 	int row, col;
356 
357 	/* check to insure all requests are idle */
358 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
359 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
360 			if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
361 				p9_debug(P9_DEBUG_MUX,
362 					 "Attempting to cleanup non-free tag %d,%d\n",
363 					 row, col);
364 				/* TODO: delay execution of cleanup */
365 				return;
366 			}
367 		}
368 	}
369 
370 	if (c->tagpool) {
371 		p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
372 		p9_idpool_destroy(c->tagpool);
373 	}
374 
375 	/* free requests associated with tags */
376 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
377 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
378 			kfree(c->reqs[row][col].wq);
379 			kfree(c->reqs[row][col].tc);
380 			kfree(c->reqs[row][col].rc);
381 		}
382 		kfree(c->reqs[row]);
383 	}
384 	c->max_tag = 0;
385 }
386 
387 /**
388  * p9_free_req - free a request and clean-up as necessary
389  * c: client state
390  * r: request to release
391  *
392  */
393 
394 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
395 {
396 	int tag = r->tc->tag;
397 	p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
398 
399 	r->status = REQ_STATUS_IDLE;
400 	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
401 		p9_idpool_put(tag, c->tagpool);
402 }
403 
404 /**
405  * p9_client_cb - call back from transport to client
406  * c: client state
407  * req: request received
408  *
409  */
410 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
411 {
412 	p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
413 	wake_up(req->wq);
414 	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
415 }
416 EXPORT_SYMBOL(p9_client_cb);
417 
418 /**
419  * p9_parse_header - parse header arguments out of a packet
420  * @pdu: packet to parse
421  * @size: size of packet
422  * @type: type of request
423  * @tag: tag of packet
424  * @rewind: set if we need to rewind offset afterwards
425  */
426 
427 int
428 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
429 								int rewind)
430 {
431 	int8_t r_type;
432 	int16_t r_tag;
433 	int32_t r_size;
434 	int offset = pdu->offset;
435 	int err;
436 
437 	pdu->offset = 0;
438 	if (pdu->size == 0)
439 		pdu->size = 7;
440 
441 	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
442 	if (err)
443 		goto rewind_and_exit;
444 
445 	pdu->size = r_size;
446 	pdu->id = r_type;
447 	pdu->tag = r_tag;
448 
449 	p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
450 		 pdu->size, pdu->id, pdu->tag);
451 
452 	if (type)
453 		*type = r_type;
454 	if (tag)
455 		*tag = r_tag;
456 	if (size)
457 		*size = r_size;
458 
459 
460 rewind_and_exit:
461 	if (rewind)
462 		pdu->offset = offset;
463 	return err;
464 }
465 EXPORT_SYMBOL(p9_parse_header);
466 
467 /**
468  * p9_check_errors - check 9p packet for error return and process it
469  * @c: current client instance
470  * @req: request to parse and check for error conditions
471  *
472  * returns error code if one is discovered, otherwise returns 0
473  *
474  * this will have to be more complicated if we have multiple
475  * error packet types
476  */
477 
478 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
479 {
480 	int8_t type;
481 	int err;
482 	int ecode;
483 
484 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
485 	/*
486 	 * dump the response from server
487 	 * This should be after check errors which poplulate pdu_fcall.
488 	 */
489 	trace_9p_protocol_dump(c, req->rc);
490 	if (err) {
491 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
492 		return err;
493 	}
494 	if (type != P9_RERROR && type != P9_RLERROR)
495 		return 0;
496 
497 	if (!p9_is_proto_dotl(c)) {
498 		char *ename;
499 		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
500 				  &ename, &ecode);
501 		if (err)
502 			goto out_err;
503 
504 		if (p9_is_proto_dotu(c))
505 			err = -ecode;
506 
507 		if (!err || !IS_ERR_VALUE(err)) {
508 			err = p9_errstr2errno(ename, strlen(ename));
509 
510 			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
511 				 -ecode, ename);
512 		}
513 		kfree(ename);
514 	} else {
515 		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
516 		err = -ecode;
517 
518 		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
519 	}
520 
521 	return err;
522 
523 out_err:
524 	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
525 
526 	return err;
527 }
528 
529 /**
530  * p9_check_zc_errors - check 9p packet for error return and process it
531  * @c: current client instance
532  * @req: request to parse and check for error conditions
533  * @in_hdrlen: Size of response protocol buffer.
534  *
535  * returns error code if one is discovered, otherwise returns 0
536  *
537  * this will have to be more complicated if we have multiple
538  * error packet types
539  */
540 
541 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
542 			      char *uidata, int in_hdrlen, int kern_buf)
543 {
544 	int err;
545 	int ecode;
546 	int8_t type;
547 	char *ename = NULL;
548 
549 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
550 	/*
551 	 * dump the response from server
552 	 * This should be after parse_header which poplulate pdu_fcall.
553 	 */
554 	trace_9p_protocol_dump(c, req->rc);
555 	if (err) {
556 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
557 		return err;
558 	}
559 
560 	if (type != P9_RERROR && type != P9_RLERROR)
561 		return 0;
562 
563 	if (!p9_is_proto_dotl(c)) {
564 		/* Error is reported in string format */
565 		uint16_t len;
566 		/* 7 = header size for RERROR, 2 is the size of string len; */
567 		int inline_len = in_hdrlen - (7 + 2);
568 
569 		/* Read the size of error string */
570 		err = p9pdu_readf(req->rc, c->proto_version, "w", &len);
571 		if (err)
572 			goto out_err;
573 
574 		ename = kmalloc(len + 1, GFP_NOFS);
575 		if (!ename) {
576 			err = -ENOMEM;
577 			goto out_err;
578 		}
579 		if (len <= inline_len) {
580 			/* We have error in protocol buffer itself */
581 			if (pdu_read(req->rc, ename, len)) {
582 				err = -EFAULT;
583 				goto out_free;
584 
585 			}
586 		} else {
587 			/*
588 			 *  Part of the data is in user space buffer.
589 			 */
590 			if (pdu_read(req->rc, ename, inline_len)) {
591 				err = -EFAULT;
592 				goto out_free;
593 
594 			}
595 			if (kern_buf) {
596 				memcpy(ename + inline_len, uidata,
597 				       len - inline_len);
598 			} else {
599 				err = copy_from_user(ename + inline_len,
600 						     uidata, len - inline_len);
601 				if (err) {
602 					err = -EFAULT;
603 					goto out_free;
604 				}
605 			}
606 		}
607 		ename[len] = 0;
608 		if (p9_is_proto_dotu(c)) {
609 			/* For dotu we also have error code */
610 			err = p9pdu_readf(req->rc,
611 					  c->proto_version, "d", &ecode);
612 			if (err)
613 				goto out_free;
614 			err = -ecode;
615 		}
616 		if (!err || !IS_ERR_VALUE(err)) {
617 			err = p9_errstr2errno(ename, strlen(ename));
618 
619 			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
620 				 -ecode, ename);
621 		}
622 		kfree(ename);
623 	} else {
624 		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
625 		err = -ecode;
626 
627 		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
628 	}
629 	return err;
630 
631 out_free:
632 	kfree(ename);
633 out_err:
634 	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
635 	return err;
636 }
637 
638 static struct p9_req_t *
639 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
640 
641 /**
642  * p9_client_flush - flush (cancel) a request
643  * @c: client state
644  * @oldreq: request to cancel
645  *
646  * This sents a flush for a particular request and links
647  * the flush request to the original request.  The current
648  * code only supports a single flush request although the protocol
649  * allows for multiple flush requests to be sent for a single request.
650  *
651  */
652 
653 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
654 {
655 	struct p9_req_t *req;
656 	int16_t oldtag;
657 	int err;
658 
659 	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
660 	if (err)
661 		return err;
662 
663 	p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
664 
665 	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
666 	if (IS_ERR(req))
667 		return PTR_ERR(req);
668 
669 
670 	/* if we haven't received a response for oldreq,
671 	   remove it from the list. */
672 	spin_lock(&c->lock);
673 	if (oldreq->status == REQ_STATUS_FLSH)
674 		list_del(&oldreq->req_list);
675 	spin_unlock(&c->lock);
676 
677 	p9_free_req(c, req);
678 	return 0;
679 }
680 
681 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
682 					      int8_t type, int req_size,
683 					      const char *fmt, va_list ap)
684 {
685 	int tag, err;
686 	struct p9_req_t *req;
687 
688 	p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
689 
690 	/* we allow for any status other than disconnected */
691 	if (c->status == Disconnected)
692 		return ERR_PTR(-EIO);
693 
694 	/* if status is begin_disconnected we allow only clunk request */
695 	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
696 		return ERR_PTR(-EIO);
697 
698 	tag = P9_NOTAG;
699 	if (type != P9_TVERSION) {
700 		tag = p9_idpool_get(c->tagpool);
701 		if (tag < 0)
702 			return ERR_PTR(-ENOMEM);
703 	}
704 
705 	req = p9_tag_alloc(c, tag, req_size);
706 	if (IS_ERR(req))
707 		return req;
708 
709 	/* marshall the data */
710 	p9pdu_prepare(req->tc, tag, type);
711 	err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
712 	if (err)
713 		goto reterr;
714 	p9pdu_finalize(c, req->tc);
715 	trace_9p_client_req(c, type, tag);
716 	return req;
717 reterr:
718 	p9_free_req(c, req);
719 	return ERR_PTR(err);
720 }
721 
722 /**
723  * p9_client_rpc - issue a request and wait for a response
724  * @c: client session
725  * @type: type of request
726  * @fmt: protocol format string (see protocol.c)
727  *
728  * Returns request structure (which client must free using p9_free_req)
729  */
730 
731 static struct p9_req_t *
732 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
733 {
734 	va_list ap;
735 	int sigpending, err;
736 	unsigned long flags;
737 	struct p9_req_t *req;
738 
739 	va_start(ap, fmt);
740 	req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
741 	va_end(ap);
742 	if (IS_ERR(req))
743 		return req;
744 
745 	if (signal_pending(current)) {
746 		sigpending = 1;
747 		clear_thread_flag(TIF_SIGPENDING);
748 	} else
749 		sigpending = 0;
750 
751 	err = c->trans_mod->request(c, req);
752 	if (err < 0) {
753 		if (err != -ERESTARTSYS && err != -EFAULT)
754 			c->status = Disconnected;
755 		goto reterr;
756 	}
757 again:
758 	/* Wait for the response */
759 	err = wait_event_interruptible(*req->wq,
760 				       req->status >= REQ_STATUS_RCVD);
761 
762 	if ((err == -ERESTARTSYS) && (c->status == Connected)
763 				  && (type == P9_TFLUSH)) {
764 		sigpending = 1;
765 		clear_thread_flag(TIF_SIGPENDING);
766 		goto again;
767 	}
768 
769 	if (req->status == REQ_STATUS_ERROR) {
770 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
771 		err = req->t_err;
772 	}
773 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
774 		p9_debug(P9_DEBUG_MUX, "flushing\n");
775 		sigpending = 1;
776 		clear_thread_flag(TIF_SIGPENDING);
777 
778 		if (c->trans_mod->cancel(c, req))
779 			p9_client_flush(c, req);
780 
781 		/* if we received the response anyway, don't signal error */
782 		if (req->status == REQ_STATUS_RCVD)
783 			err = 0;
784 	}
785 	if (sigpending) {
786 		spin_lock_irqsave(&current->sighand->siglock, flags);
787 		recalc_sigpending();
788 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
789 	}
790 	if (err < 0)
791 		goto reterr;
792 
793 	err = p9_check_errors(c, req);
794 	trace_9p_client_res(c, type, req->rc->tag, err);
795 	if (!err)
796 		return req;
797 reterr:
798 	p9_free_req(c, req);
799 	return ERR_PTR(safe_errno(err));
800 }
801 
802 /**
803  * p9_client_zc_rpc - issue a request and wait for a response
804  * @c: client session
805  * @type: type of request
806  * @uidata: user bffer that should be ued for zero copy read
807  * @uodata: user buffer that shoud be user for zero copy write
808  * @inlen: read buffer size
809  * @olen: write buffer size
810  * @hdrlen: reader header size, This is the size of response protocol data
811  * @fmt: protocol format string (see protocol.c)
812  *
813  * Returns request structure (which client must free using p9_free_req)
814  */
815 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
816 					 char *uidata, char *uodata,
817 					 int inlen, int olen, int in_hdrlen,
818 					 int kern_buf, const char *fmt, ...)
819 {
820 	va_list ap;
821 	int sigpending, err;
822 	unsigned long flags;
823 	struct p9_req_t *req;
824 
825 	va_start(ap, fmt);
826 	/*
827 	 * We allocate a inline protocol data of only 4k bytes.
828 	 * The actual content is passed in zero-copy fashion.
829 	 */
830 	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
831 	va_end(ap);
832 	if (IS_ERR(req))
833 		return req;
834 
835 	if (signal_pending(current)) {
836 		sigpending = 1;
837 		clear_thread_flag(TIF_SIGPENDING);
838 	} else
839 		sigpending = 0;
840 
841 	/* If we are called with KERNEL_DS force kern_buf */
842 	if (segment_eq(get_fs(), KERNEL_DS))
843 		kern_buf = 1;
844 
845 	err = c->trans_mod->zc_request(c, req, uidata, uodata,
846 				       inlen, olen, in_hdrlen, kern_buf);
847 	if (err < 0) {
848 		if (err == -EIO)
849 			c->status = Disconnected;
850 		goto reterr;
851 	}
852 	if (req->status == REQ_STATUS_ERROR) {
853 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
854 		err = req->t_err;
855 	}
856 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
857 		p9_debug(P9_DEBUG_MUX, "flushing\n");
858 		sigpending = 1;
859 		clear_thread_flag(TIF_SIGPENDING);
860 
861 		if (c->trans_mod->cancel(c, req))
862 			p9_client_flush(c, req);
863 
864 		/* if we received the response anyway, don't signal error */
865 		if (req->status == REQ_STATUS_RCVD)
866 			err = 0;
867 	}
868 	if (sigpending) {
869 		spin_lock_irqsave(&current->sighand->siglock, flags);
870 		recalc_sigpending();
871 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
872 	}
873 	if (err < 0)
874 		goto reterr;
875 
876 	err = p9_check_zc_errors(c, req, uidata, in_hdrlen, kern_buf);
877 	trace_9p_client_res(c, type, req->rc->tag, err);
878 	if (!err)
879 		return req;
880 reterr:
881 	p9_free_req(c, req);
882 	return ERR_PTR(safe_errno(err));
883 }
884 
885 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
886 {
887 	int ret;
888 	struct p9_fid *fid;
889 	unsigned long flags;
890 
891 	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
892 	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
893 	if (!fid)
894 		return ERR_PTR(-ENOMEM);
895 
896 	ret = p9_idpool_get(clnt->fidpool);
897 	if (ret < 0) {
898 		ret = -ENOSPC;
899 		goto error;
900 	}
901 	fid->fid = ret;
902 
903 	memset(&fid->qid, 0, sizeof(struct p9_qid));
904 	fid->mode = -1;
905 	fid->uid = current_fsuid();
906 	fid->clnt = clnt;
907 	fid->rdir = NULL;
908 	spin_lock_irqsave(&clnt->lock, flags);
909 	list_add(&fid->flist, &clnt->fidlist);
910 	spin_unlock_irqrestore(&clnt->lock, flags);
911 
912 	return fid;
913 
914 error:
915 	kfree(fid);
916 	return ERR_PTR(ret);
917 }
918 
919 static void p9_fid_destroy(struct p9_fid *fid)
920 {
921 	struct p9_client *clnt;
922 	unsigned long flags;
923 
924 	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
925 	clnt = fid->clnt;
926 	p9_idpool_put(fid->fid, clnt->fidpool);
927 	spin_lock_irqsave(&clnt->lock, flags);
928 	list_del(&fid->flist);
929 	spin_unlock_irqrestore(&clnt->lock, flags);
930 	kfree(fid->rdir);
931 	kfree(fid);
932 }
933 
934 static int p9_client_version(struct p9_client *c)
935 {
936 	int err = 0;
937 	struct p9_req_t *req;
938 	char *version;
939 	int msize;
940 
941 	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
942 		 c->msize, c->proto_version);
943 
944 	switch (c->proto_version) {
945 	case p9_proto_2000L:
946 		req = p9_client_rpc(c, P9_TVERSION, "ds",
947 					c->msize, "9P2000.L");
948 		break;
949 	case p9_proto_2000u:
950 		req = p9_client_rpc(c, P9_TVERSION, "ds",
951 					c->msize, "9P2000.u");
952 		break;
953 	case p9_proto_legacy:
954 		req = p9_client_rpc(c, P9_TVERSION, "ds",
955 					c->msize, "9P2000");
956 		break;
957 	default:
958 		return -EINVAL;
959 		break;
960 	}
961 
962 	if (IS_ERR(req))
963 		return PTR_ERR(req);
964 
965 	err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
966 	if (err) {
967 		p9_debug(P9_DEBUG_9P, "version error %d\n", err);
968 		trace_9p_protocol_dump(c, req->rc);
969 		goto error;
970 	}
971 
972 	p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
973 	if (!strncmp(version, "9P2000.L", 8))
974 		c->proto_version = p9_proto_2000L;
975 	else if (!strncmp(version, "9P2000.u", 8))
976 		c->proto_version = p9_proto_2000u;
977 	else if (!strncmp(version, "9P2000", 6))
978 		c->proto_version = p9_proto_legacy;
979 	else {
980 		err = -EREMOTEIO;
981 		goto error;
982 	}
983 
984 	if (msize < c->msize)
985 		c->msize = msize;
986 
987 error:
988 	kfree(version);
989 	p9_free_req(c, req);
990 
991 	return err;
992 }
993 
994 struct p9_client *p9_client_create(const char *dev_name, char *options)
995 {
996 	int err;
997 	struct p9_client *clnt;
998 
999 	err = 0;
1000 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1001 	if (!clnt)
1002 		return ERR_PTR(-ENOMEM);
1003 
1004 	clnt->trans_mod = NULL;
1005 	clnt->trans = NULL;
1006 	spin_lock_init(&clnt->lock);
1007 	INIT_LIST_HEAD(&clnt->fidlist);
1008 
1009 	err = p9_tag_init(clnt);
1010 	if (err < 0)
1011 		goto free_client;
1012 
1013 	err = parse_opts(options, clnt);
1014 	if (err < 0)
1015 		goto destroy_tagpool;
1016 
1017 	if (!clnt->trans_mod)
1018 		clnt->trans_mod = v9fs_get_default_trans();
1019 
1020 	if (clnt->trans_mod == NULL) {
1021 		err = -EPROTONOSUPPORT;
1022 		p9_debug(P9_DEBUG_ERROR,
1023 			 "No transport defined or default transport\n");
1024 		goto destroy_tagpool;
1025 	}
1026 
1027 	clnt->fidpool = p9_idpool_create();
1028 	if (IS_ERR(clnt->fidpool)) {
1029 		err = PTR_ERR(clnt->fidpool);
1030 		goto put_trans;
1031 	}
1032 
1033 	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1034 		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1035 
1036 	err = clnt->trans_mod->create(clnt, dev_name, options);
1037 	if (err)
1038 		goto destroy_fidpool;
1039 
1040 	if (clnt->msize > clnt->trans_mod->maxsize)
1041 		clnt->msize = clnt->trans_mod->maxsize;
1042 
1043 	err = p9_client_version(clnt);
1044 	if (err)
1045 		goto close_trans;
1046 
1047 	return clnt;
1048 
1049 close_trans:
1050 	clnt->trans_mod->close(clnt);
1051 destroy_fidpool:
1052 	p9_idpool_destroy(clnt->fidpool);
1053 put_trans:
1054 	v9fs_put_trans(clnt->trans_mod);
1055 destroy_tagpool:
1056 	p9_idpool_destroy(clnt->tagpool);
1057 free_client:
1058 	kfree(clnt);
1059 	return ERR_PTR(err);
1060 }
1061 EXPORT_SYMBOL(p9_client_create);
1062 
1063 void p9_client_destroy(struct p9_client *clnt)
1064 {
1065 	struct p9_fid *fid, *fidptr;
1066 
1067 	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1068 
1069 	if (clnt->trans_mod)
1070 		clnt->trans_mod->close(clnt);
1071 
1072 	v9fs_put_trans(clnt->trans_mod);
1073 
1074 	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1075 		pr_info("Found fid %d not clunked\n", fid->fid);
1076 		p9_fid_destroy(fid);
1077 	}
1078 
1079 	if (clnt->fidpool)
1080 		p9_idpool_destroy(clnt->fidpool);
1081 
1082 	p9_tag_cleanup(clnt);
1083 
1084 	kfree(clnt);
1085 }
1086 EXPORT_SYMBOL(p9_client_destroy);
1087 
1088 void p9_client_disconnect(struct p9_client *clnt)
1089 {
1090 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1091 	clnt->status = Disconnected;
1092 }
1093 EXPORT_SYMBOL(p9_client_disconnect);
1094 
1095 void p9_client_begin_disconnect(struct p9_client *clnt)
1096 {
1097 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1098 	clnt->status = BeginDisconnect;
1099 }
1100 EXPORT_SYMBOL(p9_client_begin_disconnect);
1101 
1102 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1103 	char *uname, u32 n_uname, char *aname)
1104 {
1105 	int err = 0;
1106 	struct p9_req_t *req;
1107 	struct p9_fid *fid;
1108 	struct p9_qid qid;
1109 
1110 
1111 	p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1112 		 afid ? afid->fid : -1, uname, aname);
1113 	fid = p9_fid_create(clnt);
1114 	if (IS_ERR(fid)) {
1115 		err = PTR_ERR(fid);
1116 		fid = NULL;
1117 		goto error;
1118 	}
1119 
1120 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
1121 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1122 	if (IS_ERR(req)) {
1123 		err = PTR_ERR(req);
1124 		goto error;
1125 	}
1126 
1127 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1128 	if (err) {
1129 		trace_9p_protocol_dump(clnt, req->rc);
1130 		p9_free_req(clnt, req);
1131 		goto error;
1132 	}
1133 
1134 	p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1135 		 qid.type, (unsigned long long)qid.path, qid.version);
1136 
1137 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1138 
1139 	p9_free_req(clnt, req);
1140 	return fid;
1141 
1142 error:
1143 	if (fid)
1144 		p9_fid_destroy(fid);
1145 	return ERR_PTR(err);
1146 }
1147 EXPORT_SYMBOL(p9_client_attach);
1148 
1149 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1150 		char **wnames, int clone)
1151 {
1152 	int err;
1153 	struct p9_client *clnt;
1154 	struct p9_fid *fid;
1155 	struct p9_qid *wqids;
1156 	struct p9_req_t *req;
1157 	uint16_t nwqids, count;
1158 
1159 	err = 0;
1160 	wqids = NULL;
1161 	clnt = oldfid->clnt;
1162 	if (clone) {
1163 		fid = p9_fid_create(clnt);
1164 		if (IS_ERR(fid)) {
1165 			err = PTR_ERR(fid);
1166 			fid = NULL;
1167 			goto error;
1168 		}
1169 
1170 		fid->uid = oldfid->uid;
1171 	} else
1172 		fid = oldfid;
1173 
1174 
1175 	p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1176 		 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1177 
1178 	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1179 								nwname, wnames);
1180 	if (IS_ERR(req)) {
1181 		err = PTR_ERR(req);
1182 		goto error;
1183 	}
1184 
1185 	err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1186 	if (err) {
1187 		trace_9p_protocol_dump(clnt, req->rc);
1188 		p9_free_req(clnt, req);
1189 		goto clunk_fid;
1190 	}
1191 	p9_free_req(clnt, req);
1192 
1193 	p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1194 
1195 	if (nwqids != nwname) {
1196 		err = -ENOENT;
1197 		goto clunk_fid;
1198 	}
1199 
1200 	for (count = 0; count < nwqids; count++)
1201 		p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1202 			count, wqids[count].type,
1203 			(unsigned long long)wqids[count].path,
1204 			wqids[count].version);
1205 
1206 	if (nwname)
1207 		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1208 	else
1209 		fid->qid = oldfid->qid;
1210 
1211 	kfree(wqids);
1212 	return fid;
1213 
1214 clunk_fid:
1215 	kfree(wqids);
1216 	p9_client_clunk(fid);
1217 	fid = NULL;
1218 
1219 error:
1220 	if (fid && (fid != oldfid))
1221 		p9_fid_destroy(fid);
1222 
1223 	return ERR_PTR(err);
1224 }
1225 EXPORT_SYMBOL(p9_client_walk);
1226 
1227 int p9_client_open(struct p9_fid *fid, int mode)
1228 {
1229 	int err;
1230 	struct p9_client *clnt;
1231 	struct p9_req_t *req;
1232 	struct p9_qid qid;
1233 	int iounit;
1234 
1235 	clnt = fid->clnt;
1236 	p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1237 		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1238 	err = 0;
1239 
1240 	if (fid->mode != -1)
1241 		return -EINVAL;
1242 
1243 	if (p9_is_proto_dotl(clnt))
1244 		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1245 	else
1246 		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1247 	if (IS_ERR(req)) {
1248 		err = PTR_ERR(req);
1249 		goto error;
1250 	}
1251 
1252 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1253 	if (err) {
1254 		trace_9p_protocol_dump(clnt, req->rc);
1255 		goto free_and_error;
1256 	}
1257 
1258 	p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1259 		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1260 		(unsigned long long)qid.path, qid.version, iounit);
1261 
1262 	fid->mode = mode;
1263 	fid->iounit = iounit;
1264 
1265 free_and_error:
1266 	p9_free_req(clnt, req);
1267 error:
1268 	return err;
1269 }
1270 EXPORT_SYMBOL(p9_client_open);
1271 
1272 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1273 		gid_t gid, struct p9_qid *qid)
1274 {
1275 	int err = 0;
1276 	struct p9_client *clnt;
1277 	struct p9_req_t *req;
1278 	int iounit;
1279 
1280 	p9_debug(P9_DEBUG_9P,
1281 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1282 			ofid->fid, name, flags, mode, gid);
1283 	clnt = ofid->clnt;
1284 
1285 	if (ofid->mode != -1)
1286 		return -EINVAL;
1287 
1288 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddd", ofid->fid, name, flags,
1289 			mode, gid);
1290 	if (IS_ERR(req)) {
1291 		err = PTR_ERR(req);
1292 		goto error;
1293 	}
1294 
1295 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1296 	if (err) {
1297 		trace_9p_protocol_dump(clnt, req->rc);
1298 		goto free_and_error;
1299 	}
1300 
1301 	p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1302 			qid->type,
1303 			(unsigned long long)qid->path,
1304 			qid->version, iounit);
1305 
1306 	ofid->mode = mode;
1307 	ofid->iounit = iounit;
1308 
1309 free_and_error:
1310 	p9_free_req(clnt, req);
1311 error:
1312 	return err;
1313 }
1314 EXPORT_SYMBOL(p9_client_create_dotl);
1315 
1316 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1317 		     char *extension)
1318 {
1319 	int err;
1320 	struct p9_client *clnt;
1321 	struct p9_req_t *req;
1322 	struct p9_qid qid;
1323 	int iounit;
1324 
1325 	p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1326 						fid->fid, name, perm, mode);
1327 	err = 0;
1328 	clnt = fid->clnt;
1329 
1330 	if (fid->mode != -1)
1331 		return -EINVAL;
1332 
1333 	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1334 				mode, extension);
1335 	if (IS_ERR(req)) {
1336 		err = PTR_ERR(req);
1337 		goto error;
1338 	}
1339 
1340 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1341 	if (err) {
1342 		trace_9p_protocol_dump(clnt, req->rc);
1343 		goto free_and_error;
1344 	}
1345 
1346 	p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1347 				qid.type,
1348 				(unsigned long long)qid.path,
1349 				qid.version, iounit);
1350 
1351 	fid->mode = mode;
1352 	fid->iounit = iounit;
1353 
1354 free_and_error:
1355 	p9_free_req(clnt, req);
1356 error:
1357 	return err;
1358 }
1359 EXPORT_SYMBOL(p9_client_fcreate);
1360 
1361 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
1362 		struct p9_qid *qid)
1363 {
1364 	int err = 0;
1365 	struct p9_client *clnt;
1366 	struct p9_req_t *req;
1367 
1368 	p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1369 			dfid->fid, name, symtgt);
1370 	clnt = dfid->clnt;
1371 
1372 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssd", dfid->fid, name, symtgt,
1373 			gid);
1374 	if (IS_ERR(req)) {
1375 		err = PTR_ERR(req);
1376 		goto error;
1377 	}
1378 
1379 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1380 	if (err) {
1381 		trace_9p_protocol_dump(clnt, req->rc);
1382 		goto free_and_error;
1383 	}
1384 
1385 	p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1386 			qid->type, (unsigned long long)qid->path, qid->version);
1387 
1388 free_and_error:
1389 	p9_free_req(clnt, req);
1390 error:
1391 	return err;
1392 }
1393 EXPORT_SYMBOL(p9_client_symlink);
1394 
1395 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1396 {
1397 	struct p9_client *clnt;
1398 	struct p9_req_t *req;
1399 
1400 	p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1401 			dfid->fid, oldfid->fid, newname);
1402 	clnt = dfid->clnt;
1403 	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1404 			newname);
1405 	if (IS_ERR(req))
1406 		return PTR_ERR(req);
1407 
1408 	p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1409 	p9_free_req(clnt, req);
1410 	return 0;
1411 }
1412 EXPORT_SYMBOL(p9_client_link);
1413 
1414 int p9_client_fsync(struct p9_fid *fid, int datasync)
1415 {
1416 	int err;
1417 	struct p9_client *clnt;
1418 	struct p9_req_t *req;
1419 
1420 	p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1421 			fid->fid, datasync);
1422 	err = 0;
1423 	clnt = fid->clnt;
1424 
1425 	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1426 	if (IS_ERR(req)) {
1427 		err = PTR_ERR(req);
1428 		goto error;
1429 	}
1430 
1431 	p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1432 
1433 	p9_free_req(clnt, req);
1434 
1435 error:
1436 	return err;
1437 }
1438 EXPORT_SYMBOL(p9_client_fsync);
1439 
1440 int p9_client_clunk(struct p9_fid *fid)
1441 {
1442 	int err;
1443 	struct p9_client *clnt;
1444 	struct p9_req_t *req;
1445 	int retries = 0;
1446 
1447 	if (!fid) {
1448 		pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1449 			__func__, task_pid_nr(current));
1450 		dump_stack();
1451 		return 0;
1452 	}
1453 
1454 again:
1455 	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1456 								retries);
1457 	err = 0;
1458 	clnt = fid->clnt;
1459 
1460 	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1461 	if (IS_ERR(req)) {
1462 		err = PTR_ERR(req);
1463 		goto error;
1464 	}
1465 
1466 	p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1467 
1468 	p9_free_req(clnt, req);
1469 error:
1470 	/*
1471 	 * Fid is not valid even after a failed clunk
1472 	 * If interrupted, retry once then give up and
1473 	 * leak fid until umount.
1474 	 */
1475 	if (err == -ERESTARTSYS) {
1476 		if (retries++ == 0)
1477 			goto again;
1478 	} else
1479 		p9_fid_destroy(fid);
1480 	return err;
1481 }
1482 EXPORT_SYMBOL(p9_client_clunk);
1483 
1484 int p9_client_remove(struct p9_fid *fid)
1485 {
1486 	int err;
1487 	struct p9_client *clnt;
1488 	struct p9_req_t *req;
1489 
1490 	p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1491 	err = 0;
1492 	clnt = fid->clnt;
1493 
1494 	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1495 	if (IS_ERR(req)) {
1496 		err = PTR_ERR(req);
1497 		goto error;
1498 	}
1499 
1500 	p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1501 
1502 	p9_free_req(clnt, req);
1503 error:
1504 	if (err == -ERESTARTSYS)
1505 		p9_client_clunk(fid);
1506 	else
1507 		p9_fid_destroy(fid);
1508 	return err;
1509 }
1510 EXPORT_SYMBOL(p9_client_remove);
1511 
1512 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1513 {
1514 	int err = 0;
1515 	struct p9_req_t *req;
1516 	struct p9_client *clnt;
1517 
1518 	p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1519 		   dfid->fid, name, flags);
1520 
1521 	clnt = dfid->clnt;
1522 	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1523 	if (IS_ERR(req)) {
1524 		err = PTR_ERR(req);
1525 		goto error;
1526 	}
1527 	p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1528 
1529 	p9_free_req(clnt, req);
1530 error:
1531 	return err;
1532 }
1533 EXPORT_SYMBOL(p9_client_unlinkat);
1534 
1535 int
1536 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1537 								u32 count)
1538 {
1539 	char *dataptr;
1540 	int kernel_buf = 0;
1541 	struct p9_req_t *req;
1542 	struct p9_client *clnt;
1543 	int err, rsize, non_zc = 0;
1544 
1545 
1546 	p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1547 		   fid->fid, (unsigned long long) offset, count);
1548 	err = 0;
1549 	clnt = fid->clnt;
1550 
1551 	rsize = fid->iounit;
1552 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1553 		rsize = clnt->msize - P9_IOHDRSZ;
1554 
1555 	if (count < rsize)
1556 		rsize = count;
1557 
1558 	/* Don't bother zerocopy for small IO (< 1024) */
1559 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1560 		char *indata;
1561 		if (data) {
1562 			kernel_buf = 1;
1563 			indata = data;
1564 		} else
1565 			indata = (__force char *)udata;
1566 		/*
1567 		 * response header len is 11
1568 		 * PDU Header(7) + IO Size (4)
1569 		 */
1570 		req = p9_client_zc_rpc(clnt, P9_TREAD, indata, NULL, rsize, 0,
1571 				       11, kernel_buf, "dqd", fid->fid,
1572 				       offset, rsize);
1573 	} else {
1574 		non_zc = 1;
1575 		req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1576 				    rsize);
1577 	}
1578 	if (IS_ERR(req)) {
1579 		err = PTR_ERR(req);
1580 		goto error;
1581 	}
1582 
1583 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1584 	if (err) {
1585 		trace_9p_protocol_dump(clnt, req->rc);
1586 		goto free_and_error;
1587 	}
1588 
1589 	p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1590 
1591 	if (non_zc) {
1592 		if (data) {
1593 			memmove(data, dataptr, count);
1594 		} else {
1595 			err = copy_to_user(udata, dataptr, count);
1596 			if (err) {
1597 				err = -EFAULT;
1598 				goto free_and_error;
1599 			}
1600 		}
1601 	}
1602 	p9_free_req(clnt, req);
1603 	return count;
1604 
1605 free_and_error:
1606 	p9_free_req(clnt, req);
1607 error:
1608 	return err;
1609 }
1610 EXPORT_SYMBOL(p9_client_read);
1611 
1612 int
1613 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1614 							u64 offset, u32 count)
1615 {
1616 	int err, rsize;
1617 	int kernel_buf = 0;
1618 	struct p9_client *clnt;
1619 	struct p9_req_t *req;
1620 
1621 	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1622 				fid->fid, (unsigned long long) offset, count);
1623 	err = 0;
1624 	clnt = fid->clnt;
1625 
1626 	rsize = fid->iounit;
1627 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1628 		rsize = clnt->msize - P9_IOHDRSZ;
1629 
1630 	if (count < rsize)
1631 		rsize = count;
1632 
1633 	/* Don't bother zerocopy for small IO (< 1024) */
1634 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1635 		char *odata;
1636 		if (data) {
1637 			kernel_buf = 1;
1638 			odata = data;
1639 		} else
1640 			odata = (char *)udata;
1641 		req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, odata, 0, rsize,
1642 				       P9_ZC_HDR_SZ, kernel_buf, "dqd",
1643 				       fid->fid, offset, rsize);
1644 	} else {
1645 		if (data)
1646 			req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1647 					    offset, rsize, data);
1648 		else
1649 			req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1650 					    offset, rsize, udata);
1651 	}
1652 	if (IS_ERR(req)) {
1653 		err = PTR_ERR(req);
1654 		goto error;
1655 	}
1656 
1657 	err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1658 	if (err) {
1659 		trace_9p_protocol_dump(clnt, req->rc);
1660 		goto free_and_error;
1661 	}
1662 
1663 	p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1664 
1665 	p9_free_req(clnt, req);
1666 	return count;
1667 
1668 free_and_error:
1669 	p9_free_req(clnt, req);
1670 error:
1671 	return err;
1672 }
1673 EXPORT_SYMBOL(p9_client_write);
1674 
1675 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1676 {
1677 	int err;
1678 	struct p9_client *clnt;
1679 	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1680 	struct p9_req_t *req;
1681 	u16 ignored;
1682 
1683 	p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1684 
1685 	if (!ret)
1686 		return ERR_PTR(-ENOMEM);
1687 
1688 	err = 0;
1689 	clnt = fid->clnt;
1690 
1691 	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1692 	if (IS_ERR(req)) {
1693 		err = PTR_ERR(req);
1694 		goto error;
1695 	}
1696 
1697 	err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1698 	if (err) {
1699 		trace_9p_protocol_dump(clnt, req->rc);
1700 		p9_free_req(clnt, req);
1701 		goto error;
1702 	}
1703 
1704 	p9_debug(P9_DEBUG_9P,
1705 		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1706 		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1707 		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1708 		"<<<    uid=%d gid=%d n_muid=%d\n",
1709 		ret->size, ret->type, ret->dev, ret->qid.type,
1710 		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1711 		ret->atime, ret->mtime, (unsigned long long)ret->length,
1712 		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1713 		ret->n_uid, ret->n_gid, ret->n_muid);
1714 
1715 	p9_free_req(clnt, req);
1716 	return ret;
1717 
1718 error:
1719 	kfree(ret);
1720 	return ERR_PTR(err);
1721 }
1722 EXPORT_SYMBOL(p9_client_stat);
1723 
1724 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1725 							u64 request_mask)
1726 {
1727 	int err;
1728 	struct p9_client *clnt;
1729 	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1730 								GFP_KERNEL);
1731 	struct p9_req_t *req;
1732 
1733 	p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1734 							fid->fid, request_mask);
1735 
1736 	if (!ret)
1737 		return ERR_PTR(-ENOMEM);
1738 
1739 	err = 0;
1740 	clnt = fid->clnt;
1741 
1742 	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1743 	if (IS_ERR(req)) {
1744 		err = PTR_ERR(req);
1745 		goto error;
1746 	}
1747 
1748 	err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1749 	if (err) {
1750 		trace_9p_protocol_dump(clnt, req->rc);
1751 		p9_free_req(clnt, req);
1752 		goto error;
1753 	}
1754 
1755 	p9_debug(P9_DEBUG_9P,
1756 		"<<< RGETATTR st_result_mask=%lld\n"
1757 		"<<< qid=%x.%llx.%x\n"
1758 		"<<< st_mode=%8.8x st_nlink=%llu\n"
1759 		"<<< st_uid=%d st_gid=%d\n"
1760 		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1761 		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1762 		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1763 		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1764 		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1765 		"<<< st_gen=%lld st_data_version=%lld",
1766 		ret->st_result_mask, ret->qid.type, ret->qid.path,
1767 		ret->qid.version, ret->st_mode, ret->st_nlink, ret->st_uid,
1768 		ret->st_gid, ret->st_rdev, ret->st_size, ret->st_blksize,
1769 		ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1770 		ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1771 		ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1772 		ret->st_gen, ret->st_data_version);
1773 
1774 	p9_free_req(clnt, req);
1775 	return ret;
1776 
1777 error:
1778 	kfree(ret);
1779 	return ERR_PTR(err);
1780 }
1781 EXPORT_SYMBOL(p9_client_getattr_dotl);
1782 
1783 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1784 {
1785 	int ret;
1786 
1787 	/* NOTE: size shouldn't include its own length */
1788 	/* size[2] type[2] dev[4] qid[13] */
1789 	/* mode[4] atime[4] mtime[4] length[8]*/
1790 	/* name[s] uid[s] gid[s] muid[s] */
1791 	ret = 2+4+13+4+4+4+8+2+2+2+2;
1792 
1793 	if (wst->name)
1794 		ret += strlen(wst->name);
1795 	if (wst->uid)
1796 		ret += strlen(wst->uid);
1797 	if (wst->gid)
1798 		ret += strlen(wst->gid);
1799 	if (wst->muid)
1800 		ret += strlen(wst->muid);
1801 
1802 	if ((proto_version == p9_proto_2000u) ||
1803 		(proto_version == p9_proto_2000L)) {
1804 		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1805 		if (wst->extension)
1806 			ret += strlen(wst->extension);
1807 	}
1808 
1809 	return ret;
1810 }
1811 
1812 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1813 {
1814 	int err;
1815 	struct p9_req_t *req;
1816 	struct p9_client *clnt;
1817 
1818 	err = 0;
1819 	clnt = fid->clnt;
1820 	wst->size = p9_client_statsize(wst, clnt->proto_version);
1821 	p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1822 	p9_debug(P9_DEBUG_9P,
1823 		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1824 		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1825 		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1826 		"     uid=%d gid=%d n_muid=%d\n",
1827 		wst->size, wst->type, wst->dev, wst->qid.type,
1828 		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1829 		wst->atime, wst->mtime, (unsigned long long)wst->length,
1830 		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1831 		wst->n_uid, wst->n_gid, wst->n_muid);
1832 
1833 	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1834 	if (IS_ERR(req)) {
1835 		err = PTR_ERR(req);
1836 		goto error;
1837 	}
1838 
1839 	p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1840 
1841 	p9_free_req(clnt, req);
1842 error:
1843 	return err;
1844 }
1845 EXPORT_SYMBOL(p9_client_wstat);
1846 
1847 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1848 {
1849 	int err;
1850 	struct p9_req_t *req;
1851 	struct p9_client *clnt;
1852 
1853 	err = 0;
1854 	clnt = fid->clnt;
1855 	p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1856 	p9_debug(P9_DEBUG_9P,
1857 		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1858 		"    atime_sec=%lld atime_nsec=%lld\n"
1859 		"    mtime_sec=%lld mtime_nsec=%lld\n",
1860 		p9attr->valid, p9attr->mode, p9attr->uid, p9attr->gid,
1861 		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1862 		p9attr->mtime_sec, p9attr->mtime_nsec);
1863 
1864 	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1865 
1866 	if (IS_ERR(req)) {
1867 		err = PTR_ERR(req);
1868 		goto error;
1869 	}
1870 	p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1871 	p9_free_req(clnt, req);
1872 error:
1873 	return err;
1874 }
1875 EXPORT_SYMBOL(p9_client_setattr);
1876 
1877 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1878 {
1879 	int err;
1880 	struct p9_req_t *req;
1881 	struct p9_client *clnt;
1882 
1883 	err = 0;
1884 	clnt = fid->clnt;
1885 
1886 	p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1887 
1888 	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1889 	if (IS_ERR(req)) {
1890 		err = PTR_ERR(req);
1891 		goto error;
1892 	}
1893 
1894 	err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1895 		&sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1896 		&sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1897 	if (err) {
1898 		trace_9p_protocol_dump(clnt, req->rc);
1899 		p9_free_req(clnt, req);
1900 		goto error;
1901 	}
1902 
1903 	p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1904 		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1905 		"fsid %llu namelen %ld\n",
1906 		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1907 		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1908 		sb->fsid, (long int)sb->namelen);
1909 
1910 	p9_free_req(clnt, req);
1911 error:
1912 	return err;
1913 }
1914 EXPORT_SYMBOL(p9_client_statfs);
1915 
1916 int p9_client_rename(struct p9_fid *fid,
1917 		     struct p9_fid *newdirfid, const char *name)
1918 {
1919 	int err;
1920 	struct p9_req_t *req;
1921 	struct p9_client *clnt;
1922 
1923 	err = 0;
1924 	clnt = fid->clnt;
1925 
1926 	p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1927 			fid->fid, newdirfid->fid, name);
1928 
1929 	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1930 			newdirfid->fid, name);
1931 	if (IS_ERR(req)) {
1932 		err = PTR_ERR(req);
1933 		goto error;
1934 	}
1935 
1936 	p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1937 
1938 	p9_free_req(clnt, req);
1939 error:
1940 	return err;
1941 }
1942 EXPORT_SYMBOL(p9_client_rename);
1943 
1944 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1945 		       struct p9_fid *newdirfid, const char *new_name)
1946 {
1947 	int err;
1948 	struct p9_req_t *req;
1949 	struct p9_client *clnt;
1950 
1951 	err = 0;
1952 	clnt = olddirfid->clnt;
1953 
1954 	p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1955 		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1956 		   newdirfid->fid, new_name);
1957 
1958 	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1959 			    old_name, newdirfid->fid, new_name);
1960 	if (IS_ERR(req)) {
1961 		err = PTR_ERR(req);
1962 		goto error;
1963 	}
1964 
1965 	p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1966 		   newdirfid->fid, new_name);
1967 
1968 	p9_free_req(clnt, req);
1969 error:
1970 	return err;
1971 }
1972 EXPORT_SYMBOL(p9_client_renameat);
1973 
1974 /*
1975  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1976  */
1977 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1978 				const char *attr_name, u64 *attr_size)
1979 {
1980 	int err;
1981 	struct p9_req_t *req;
1982 	struct p9_client *clnt;
1983 	struct p9_fid *attr_fid;
1984 
1985 	err = 0;
1986 	clnt = file_fid->clnt;
1987 	attr_fid = p9_fid_create(clnt);
1988 	if (IS_ERR(attr_fid)) {
1989 		err = PTR_ERR(attr_fid);
1990 		attr_fid = NULL;
1991 		goto error;
1992 	}
1993 	p9_debug(P9_DEBUG_9P,
1994 		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1995 		file_fid->fid, attr_fid->fid, attr_name);
1996 
1997 	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1998 			file_fid->fid, attr_fid->fid, attr_name);
1999 	if (IS_ERR(req)) {
2000 		err = PTR_ERR(req);
2001 		goto error;
2002 	}
2003 	err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2004 	if (err) {
2005 		trace_9p_protocol_dump(clnt, req->rc);
2006 		p9_free_req(clnt, req);
2007 		goto clunk_fid;
2008 	}
2009 	p9_free_req(clnt, req);
2010 	p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2011 		attr_fid->fid, *attr_size);
2012 	return attr_fid;
2013 clunk_fid:
2014 	p9_client_clunk(attr_fid);
2015 	attr_fid = NULL;
2016 error:
2017 	if (attr_fid && (attr_fid != file_fid))
2018 		p9_fid_destroy(attr_fid);
2019 
2020 	return ERR_PTR(err);
2021 }
2022 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2023 
2024 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2025 			u64 attr_size, int flags)
2026 {
2027 	int err;
2028 	struct p9_req_t *req;
2029 	struct p9_client *clnt;
2030 
2031 	p9_debug(P9_DEBUG_9P,
2032 		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2033 		fid->fid, name, (long long)attr_size, flags);
2034 	err = 0;
2035 	clnt = fid->clnt;
2036 	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2037 			fid->fid, name, attr_size, flags);
2038 	if (IS_ERR(req)) {
2039 		err = PTR_ERR(req);
2040 		goto error;
2041 	}
2042 	p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2043 	p9_free_req(clnt, req);
2044 error:
2045 	return err;
2046 }
2047 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2048 
2049 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2050 {
2051 	int err, rsize, non_zc = 0;
2052 	struct p9_client *clnt;
2053 	struct p9_req_t *req;
2054 	char *dataptr;
2055 
2056 	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2057 				fid->fid, (unsigned long long) offset, count);
2058 
2059 	err = 0;
2060 	clnt = fid->clnt;
2061 
2062 	rsize = fid->iounit;
2063 	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2064 		rsize = clnt->msize - P9_READDIRHDRSZ;
2065 
2066 	if (count < rsize)
2067 		rsize = count;
2068 
2069 	/* Don't bother zerocopy for small IO (< 1024) */
2070 	if (clnt->trans_mod->zc_request && rsize > 1024) {
2071 		/*
2072 		 * response header len is 11
2073 		 * PDU Header(7) + IO Size (4)
2074 		 */
2075 		req = p9_client_zc_rpc(clnt, P9_TREADDIR, data, NULL, rsize, 0,
2076 				       11, 1, "dqd", fid->fid, offset, rsize);
2077 	} else {
2078 		non_zc = 1;
2079 		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2080 				    offset, rsize);
2081 	}
2082 	if (IS_ERR(req)) {
2083 		err = PTR_ERR(req);
2084 		goto error;
2085 	}
2086 
2087 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2088 	if (err) {
2089 		trace_9p_protocol_dump(clnt, req->rc);
2090 		goto free_and_error;
2091 	}
2092 
2093 	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2094 
2095 	if (non_zc)
2096 		memmove(data, dataptr, count);
2097 
2098 	p9_free_req(clnt, req);
2099 	return count;
2100 
2101 free_and_error:
2102 	p9_free_req(clnt, req);
2103 error:
2104 	return err;
2105 }
2106 EXPORT_SYMBOL(p9_client_readdir);
2107 
2108 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2109 			dev_t rdev, gid_t gid, struct p9_qid *qid)
2110 {
2111 	int err;
2112 	struct p9_client *clnt;
2113 	struct p9_req_t *req;
2114 
2115 	err = 0;
2116 	clnt = fid->clnt;
2117 	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2118 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2119 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddd", fid->fid, name, mode,
2120 		MAJOR(rdev), MINOR(rdev), gid);
2121 	if (IS_ERR(req))
2122 		return PTR_ERR(req);
2123 
2124 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2125 	if (err) {
2126 		trace_9p_protocol_dump(clnt, req->rc);
2127 		goto error;
2128 	}
2129 	p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2130 				(unsigned long long)qid->path, qid->version);
2131 
2132 error:
2133 	p9_free_req(clnt, req);
2134 	return err;
2135 
2136 }
2137 EXPORT_SYMBOL(p9_client_mknod_dotl);
2138 
2139 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2140 				gid_t gid, struct p9_qid *qid)
2141 {
2142 	int err;
2143 	struct p9_client *clnt;
2144 	struct p9_req_t *req;
2145 
2146 	err = 0;
2147 	clnt = fid->clnt;
2148 	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2149 		 fid->fid, name, mode, gid);
2150 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdd", fid->fid, name, mode,
2151 		gid);
2152 	if (IS_ERR(req))
2153 		return PTR_ERR(req);
2154 
2155 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2156 	if (err) {
2157 		trace_9p_protocol_dump(clnt, req->rc);
2158 		goto error;
2159 	}
2160 	p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2161 				(unsigned long long)qid->path, qid->version);
2162 
2163 error:
2164 	p9_free_req(clnt, req);
2165 	return err;
2166 
2167 }
2168 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2169 
2170 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2171 {
2172 	int err;
2173 	struct p9_client *clnt;
2174 	struct p9_req_t *req;
2175 
2176 	err = 0;
2177 	clnt = fid->clnt;
2178 	p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2179 			"start %lld length %lld proc_id %d client_id %s\n",
2180 			fid->fid, flock->type, flock->flags, flock->start,
2181 			flock->length, flock->proc_id, flock->client_id);
2182 
2183 	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2184 				flock->flags, flock->start, flock->length,
2185 					flock->proc_id, flock->client_id);
2186 
2187 	if (IS_ERR(req))
2188 		return PTR_ERR(req);
2189 
2190 	err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2191 	if (err) {
2192 		trace_9p_protocol_dump(clnt, req->rc);
2193 		goto error;
2194 	}
2195 	p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2196 error:
2197 	p9_free_req(clnt, req);
2198 	return err;
2199 
2200 }
2201 EXPORT_SYMBOL(p9_client_lock_dotl);
2202 
2203 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2204 {
2205 	int err;
2206 	struct p9_client *clnt;
2207 	struct p9_req_t *req;
2208 
2209 	err = 0;
2210 	clnt = fid->clnt;
2211 	p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2212 		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2213 		glock->start, glock->length, glock->proc_id, glock->client_id);
2214 
2215 	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2216 		glock->start, glock->length, glock->proc_id, glock->client_id);
2217 
2218 	if (IS_ERR(req))
2219 		return PTR_ERR(req);
2220 
2221 	err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2222 			&glock->start, &glock->length, &glock->proc_id,
2223 			&glock->client_id);
2224 	if (err) {
2225 		trace_9p_protocol_dump(clnt, req->rc);
2226 		goto error;
2227 	}
2228 	p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2229 		"proc_id %d client_id %s\n", glock->type, glock->start,
2230 		glock->length, glock->proc_id, glock->client_id);
2231 error:
2232 	p9_free_req(clnt, req);
2233 	return err;
2234 }
2235 EXPORT_SYMBOL(p9_client_getlock_dotl);
2236 
2237 int p9_client_readlink(struct p9_fid *fid, char **target)
2238 {
2239 	int err;
2240 	struct p9_client *clnt;
2241 	struct p9_req_t *req;
2242 
2243 	err = 0;
2244 	clnt = fid->clnt;
2245 	p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2246 
2247 	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2248 	if (IS_ERR(req))
2249 		return PTR_ERR(req);
2250 
2251 	err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2252 	if (err) {
2253 		trace_9p_protocol_dump(clnt, req->rc);
2254 		goto error;
2255 	}
2256 	p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2257 error:
2258 	p9_free_req(clnt, req);
2259 	return err;
2260 }
2261 EXPORT_SYMBOL(p9_client_readlink);
2262