xref: /linux/net/9p/client.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2)
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 #define CREATE_TRACE_POINTS
42 #include <trace/events/9p.h>
43 
44 /*
45   * Client Option Parsing (code inspired by NFS code)
46   *  - a little lazy - parse all client options
47   */
48 
49 enum {
50 	Opt_msize,
51 	Opt_trans,
52 	Opt_legacy,
53 	Opt_version,
54 	Opt_err,
55 };
56 
57 static const match_table_t tokens = {
58 	{Opt_msize, "msize=%u"},
59 	{Opt_legacy, "noextend"},
60 	{Opt_trans, "trans=%s"},
61 	{Opt_version, "version=%s"},
62 	{Opt_err, NULL},
63 };
64 
65 inline int p9_is_proto_dotl(struct p9_client *clnt)
66 {
67 	return clnt->proto_version == p9_proto_2000L;
68 }
69 EXPORT_SYMBOL(p9_is_proto_dotl);
70 
71 inline int p9_is_proto_dotu(struct p9_client *clnt)
72 {
73 	return clnt->proto_version == p9_proto_2000u;
74 }
75 EXPORT_SYMBOL(p9_is_proto_dotu);
76 
77 /* Interpret mount option for protocol version */
78 static int get_protocol_version(char *s)
79 {
80 	int version = -EINVAL;
81 
82 	if (!strcmp(s, "9p2000")) {
83 		version = p9_proto_legacy;
84 		P9_DPRINTK(P9_DEBUG_9P, "Protocol version: Legacy\n");
85 	} else if (!strcmp(s, "9p2000.u")) {
86 		version = p9_proto_2000u;
87 		P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
88 	} else if (!strcmp(s, "9p2000.L")) {
89 		version = p9_proto_2000L;
90 		P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
91 	} else
92 		printk(KERN_INFO "9p: Unknown protocol version %s.\n", s);
93 
94 	return version;
95 }
96 
97 /**
98  * parse_options - parse mount options into client structure
99  * @opts: options string passed from mount
100  * @clnt: existing v9fs client information
101  *
102  * Return 0 upon success, -ERRNO upon failure
103  */
104 
105 static int parse_opts(char *opts, struct p9_client *clnt)
106 {
107 	char *options, *tmp_options;
108 	char *p;
109 	substring_t args[MAX_OPT_ARGS];
110 	int option;
111 	char *s;
112 	int ret = 0;
113 
114 	clnt->proto_version = p9_proto_2000u;
115 	clnt->msize = 8192;
116 
117 	if (!opts)
118 		return 0;
119 
120 	tmp_options = kstrdup(opts, GFP_KERNEL);
121 	if (!tmp_options) {
122 		P9_DPRINTK(P9_DEBUG_ERROR,
123 				"failed to allocate copy of option string\n");
124 		return -ENOMEM;
125 	}
126 	options = tmp_options;
127 
128 	while ((p = strsep(&options, ",")) != NULL) {
129 		int token, r;
130 		if (!*p)
131 			continue;
132 		token = match_token(p, tokens, args);
133 		switch (token) {
134 		case Opt_msize:
135 			r = match_int(&args[0], &option);
136 			if (r < 0) {
137 				P9_DPRINTK(P9_DEBUG_ERROR,
138 					   "integer field, but no integer?\n");
139 				ret = r;
140 				continue;
141 			}
142 			clnt->msize = option;
143 			break;
144 		case Opt_trans:
145 			s = match_strdup(&args[0]);
146 			if (!s) {
147 				ret = -ENOMEM;
148 				P9_DPRINTK(P9_DEBUG_ERROR,
149 					"problem allocating copy of trans arg\n");
150 				goto free_and_return;
151 			 }
152 			clnt->trans_mod = v9fs_get_trans_by_name(s);
153 			if (clnt->trans_mod == NULL) {
154 				printk(KERN_INFO
155 					"9p: Could not find "
156 					"request transport: %s\n", s);
157 				ret = -EINVAL;
158 				kfree(s);
159 				goto free_and_return;
160 			}
161 			kfree(s);
162 			break;
163 		case Opt_legacy:
164 			clnt->proto_version = p9_proto_legacy;
165 			break;
166 		case Opt_version:
167 			s = match_strdup(&args[0]);
168 			if (!s) {
169 				ret = -ENOMEM;
170 				P9_DPRINTK(P9_DEBUG_ERROR,
171 					"problem allocating copy of version arg\n");
172 				goto free_and_return;
173 			}
174 			ret = get_protocol_version(s);
175 			if (ret == -EINVAL) {
176 				kfree(s);
177 				goto free_and_return;
178 			}
179 			kfree(s);
180 			clnt->proto_version = ret;
181 			break;
182 		default:
183 			continue;
184 		}
185 	}
186 
187 free_and_return:
188 	kfree(tmp_options);
189 	return ret;
190 }
191 
192 /**
193  * p9_tag_alloc - lookup/allocate a request by tag
194  * @c: client session to lookup tag within
195  * @tag: numeric id for transaction
196  *
197  * this is a simple array lookup, but will grow the
198  * request_slots as necessary to accommodate transaction
199  * ids which did not previously have a slot.
200  *
201  * this code relies on the client spinlock to manage locks, its
202  * possible we should switch to something else, but I'd rather
203  * stick with something low-overhead for the common case.
204  *
205  */
206 
207 static struct p9_req_t *
208 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
209 {
210 	unsigned long flags;
211 	int row, col;
212 	struct p9_req_t *req;
213 	int alloc_msize = min(c->msize, max_size);
214 
215 	/* This looks up the original request by tag so we know which
216 	 * buffer to read the data into */
217 	tag++;
218 
219 	if (tag >= c->max_tag) {
220 		spin_lock_irqsave(&c->lock, flags);
221 		/* check again since original check was outside of lock */
222 		while (tag >= c->max_tag) {
223 			row = (tag / P9_ROW_MAXTAG);
224 			c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
225 					sizeof(struct p9_req_t), GFP_ATOMIC);
226 
227 			if (!c->reqs[row]) {
228 				printk(KERN_ERR "Couldn't grow tag array\n");
229 				spin_unlock_irqrestore(&c->lock, flags);
230 				return ERR_PTR(-ENOMEM);
231 			}
232 			for (col = 0; col < P9_ROW_MAXTAG; col++) {
233 				c->reqs[row][col].status = REQ_STATUS_IDLE;
234 				c->reqs[row][col].tc = NULL;
235 			}
236 			c->max_tag += P9_ROW_MAXTAG;
237 		}
238 		spin_unlock_irqrestore(&c->lock, flags);
239 	}
240 	row = tag / P9_ROW_MAXTAG;
241 	col = tag % P9_ROW_MAXTAG;
242 
243 	req = &c->reqs[row][col];
244 	if (!req->tc) {
245 		req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
246 		if (!req->wq) {
247 			printk(KERN_ERR "Couldn't grow tag array\n");
248 			return ERR_PTR(-ENOMEM);
249 		}
250 		init_waitqueue_head(req->wq);
251 		req->tc = kmalloc(sizeof(struct p9_fcall) + alloc_msize,
252 				  GFP_NOFS);
253 		req->rc = kmalloc(sizeof(struct p9_fcall) + alloc_msize,
254 				  GFP_NOFS);
255 		if ((!req->tc) || (!req->rc)) {
256 			printk(KERN_ERR "Couldn't grow tag array\n");
257 			kfree(req->tc);
258 			kfree(req->rc);
259 			kfree(req->wq);
260 			req->tc = req->rc = NULL;
261 			req->wq = NULL;
262 			return ERR_PTR(-ENOMEM);
263 		}
264 		req->tc->capacity = alloc_msize;
265 		req->rc->capacity = alloc_msize;
266 		req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
267 		req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
268 	}
269 
270 	p9pdu_reset(req->tc);
271 	p9pdu_reset(req->rc);
272 
273 	req->tc->tag = tag-1;
274 	req->status = REQ_STATUS_ALLOC;
275 
276 	return &c->reqs[row][col];
277 }
278 
279 /**
280  * p9_tag_lookup - lookup a request by tag
281  * @c: client session to lookup tag within
282  * @tag: numeric id for transaction
283  *
284  */
285 
286 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
287 {
288 	int row, col;
289 
290 	/* This looks up the original request by tag so we know which
291 	 * buffer to read the data into */
292 	tag++;
293 
294 	if(tag >= c->max_tag)
295 		return NULL;
296 
297 	row = tag / P9_ROW_MAXTAG;
298 	col = tag % P9_ROW_MAXTAG;
299 
300 	return &c->reqs[row][col];
301 }
302 EXPORT_SYMBOL(p9_tag_lookup);
303 
304 /**
305  * p9_tag_init - setup tags structure and contents
306  * @c:  v9fs client struct
307  *
308  * This initializes the tags structure for each client instance.
309  *
310  */
311 
312 static int p9_tag_init(struct p9_client *c)
313 {
314 	int err = 0;
315 
316 	c->tagpool = p9_idpool_create();
317 	if (IS_ERR(c->tagpool)) {
318 		err = PTR_ERR(c->tagpool);
319 		goto error;
320 	}
321 	err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
322 	if (err < 0) {
323 		p9_idpool_destroy(c->tagpool);
324 		goto error;
325 	}
326 	c->max_tag = 0;
327 error:
328 	return err;
329 }
330 
331 /**
332  * p9_tag_cleanup - cleans up tags structure and reclaims resources
333  * @c:  v9fs client struct
334  *
335  * This frees resources associated with the tags structure
336  *
337  */
338 static void p9_tag_cleanup(struct p9_client *c)
339 {
340 	int row, col;
341 
342 	/* check to insure all requests are idle */
343 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
344 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
345 			if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
346 				P9_DPRINTK(P9_DEBUG_MUX,
347 				  "Attempting to cleanup non-free tag %d,%d\n",
348 				  row, col);
349 				/* TODO: delay execution of cleanup */
350 				return;
351 			}
352 		}
353 	}
354 
355 	if (c->tagpool) {
356 		p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
357 		p9_idpool_destroy(c->tagpool);
358 	}
359 
360 	/* free requests associated with tags */
361 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
362 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
363 			kfree(c->reqs[row][col].wq);
364 			kfree(c->reqs[row][col].tc);
365 			kfree(c->reqs[row][col].rc);
366 		}
367 		kfree(c->reqs[row]);
368 	}
369 	c->max_tag = 0;
370 }
371 
372 /**
373  * p9_free_req - free a request and clean-up as necessary
374  * c: client state
375  * r: request to release
376  *
377  */
378 
379 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
380 {
381 	int tag = r->tc->tag;
382 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
383 
384 	r->status = REQ_STATUS_IDLE;
385 	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
386 		p9_idpool_put(tag, c->tagpool);
387 }
388 
389 /**
390  * p9_client_cb - call back from transport to client
391  * c: client state
392  * req: request received
393  *
394  */
395 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
396 {
397 	P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
398 	wake_up(req->wq);
399 	P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
400 }
401 EXPORT_SYMBOL(p9_client_cb);
402 
403 /**
404  * p9_parse_header - parse header arguments out of a packet
405  * @pdu: packet to parse
406  * @size: size of packet
407  * @type: type of request
408  * @tag: tag of packet
409  * @rewind: set if we need to rewind offset afterwards
410  */
411 
412 int
413 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
414 								int rewind)
415 {
416 	int8_t r_type;
417 	int16_t r_tag;
418 	int32_t r_size;
419 	int offset = pdu->offset;
420 	int err;
421 
422 	pdu->offset = 0;
423 	if (pdu->size == 0)
424 		pdu->size = 7;
425 
426 	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
427 	if (err)
428 		goto rewind_and_exit;
429 
430 	pdu->size = r_size;
431 	pdu->id = r_type;
432 	pdu->tag = r_tag;
433 
434 	P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
435 							pdu->id, pdu->tag);
436 
437 	if (type)
438 		*type = r_type;
439 	if (tag)
440 		*tag = r_tag;
441 	if (size)
442 		*size = r_size;
443 
444 
445 rewind_and_exit:
446 	if (rewind)
447 		pdu->offset = offset;
448 	return err;
449 }
450 EXPORT_SYMBOL(p9_parse_header);
451 
452 /**
453  * p9_check_errors - check 9p packet for error return and process it
454  * @c: current client instance
455  * @req: request to parse and check for error conditions
456  *
457  * returns error code if one is discovered, otherwise returns 0
458  *
459  * this will have to be more complicated if we have multiple
460  * error packet types
461  */
462 
463 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
464 {
465 	int8_t type;
466 	int err;
467 	int ecode;
468 
469 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
470 	/*
471 	 * dump the response from server
472 	 * This should be after check errors which poplulate pdu_fcall.
473 	 */
474 	trace_9p_protocol_dump(c, req->rc);
475 	if (err) {
476 		P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
477 		return err;
478 	}
479 	if (type != P9_RERROR && type != P9_RLERROR)
480 		return 0;
481 
482 	if (!p9_is_proto_dotl(c)) {
483 		char *ename;
484 		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
485 				  &ename, &ecode);
486 		if (err)
487 			goto out_err;
488 
489 		if (p9_is_proto_dotu(c))
490 			err = -ecode;
491 
492 		if (!err || !IS_ERR_VALUE(err)) {
493 			err = p9_errstr2errno(ename, strlen(ename));
494 
495 			P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
496 				   -ecode, ename);
497 		}
498 		kfree(ename);
499 	} else {
500 		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
501 		err = -ecode;
502 
503 		P9_DPRINTK(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
504 	}
505 
506 	return err;
507 
508 out_err:
509 	P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
510 
511 	return err;
512 }
513 
514 /**
515  * p9_check_zc_errors - check 9p packet for error return and process it
516  * @c: current client instance
517  * @req: request to parse and check for error conditions
518  * @in_hdrlen: Size of response protocol buffer.
519  *
520  * returns error code if one is discovered, otherwise returns 0
521  *
522  * this will have to be more complicated if we have multiple
523  * error packet types
524  */
525 
526 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
527 			      char *uidata, int in_hdrlen, int kern_buf)
528 {
529 	int err;
530 	int ecode;
531 	int8_t type;
532 	char *ename = NULL;
533 
534 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
535 	/*
536 	 * dump the response from server
537 	 * This should be after parse_header which poplulate pdu_fcall.
538 	 */
539 	trace_9p_protocol_dump(c, req->rc);
540 	if (err) {
541 		P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
542 		return err;
543 	}
544 
545 	if (type != P9_RERROR && type != P9_RLERROR)
546 		return 0;
547 
548 	if (!p9_is_proto_dotl(c)) {
549 		/* Error is reported in string format */
550 		uint16_t len;
551 		/* 7 = header size for RERROR, 2 is the size of string len; */
552 		int inline_len = in_hdrlen - (7 + 2);
553 
554 		/* Read the size of error string */
555 		err = p9pdu_readf(req->rc, c->proto_version, "w", &len);
556 		if (err)
557 			goto out_err;
558 
559 		ename = kmalloc(len + 1, GFP_NOFS);
560 		if (!ename) {
561 			err = -ENOMEM;
562 			goto out_err;
563 		}
564 		if (len <= inline_len) {
565 			/* We have error in protocol buffer itself */
566 			if (pdu_read(req->rc, ename, len)) {
567 				err = -EFAULT;
568 				goto out_free;
569 
570 			}
571 		} else {
572 			/*
573 			 *  Part of the data is in user space buffer.
574 			 */
575 			if (pdu_read(req->rc, ename, inline_len)) {
576 				err = -EFAULT;
577 				goto out_free;
578 
579 			}
580 			if (kern_buf) {
581 				memcpy(ename + inline_len, uidata,
582 				       len - inline_len);
583 			} else {
584 				err = copy_from_user(ename + inline_len,
585 						     uidata, len - inline_len);
586 				if (err) {
587 					err = -EFAULT;
588 					goto out_free;
589 				}
590 			}
591 		}
592 		ename[len] = 0;
593 		if (p9_is_proto_dotu(c)) {
594 			/* For dotu we also have error code */
595 			err = p9pdu_readf(req->rc,
596 					  c->proto_version, "d", &ecode);
597 			if (err)
598 				goto out_free;
599 			err = -ecode;
600 		}
601 		if (!err || !IS_ERR_VALUE(err)) {
602 			err = p9_errstr2errno(ename, strlen(ename));
603 
604 			P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
605 				   -ecode, ename);
606 		}
607 		kfree(ename);
608 	} else {
609 		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
610 		err = -ecode;
611 
612 		P9_DPRINTK(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
613 	}
614 	return err;
615 
616 out_free:
617 	kfree(ename);
618 out_err:
619 	P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
620 	return err;
621 }
622 
623 static struct p9_req_t *
624 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
625 
626 /**
627  * p9_client_flush - flush (cancel) a request
628  * @c: client state
629  * @oldreq: request to cancel
630  *
631  * This sents a flush for a particular request and links
632  * the flush request to the original request.  The current
633  * code only supports a single flush request although the protocol
634  * allows for multiple flush requests to be sent for a single request.
635  *
636  */
637 
638 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
639 {
640 	struct p9_req_t *req;
641 	int16_t oldtag;
642 	int err;
643 
644 	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
645 	if (err)
646 		return err;
647 
648 	P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
649 
650 	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
651 	if (IS_ERR(req))
652 		return PTR_ERR(req);
653 
654 
655 	/* if we haven't received a response for oldreq,
656 	   remove it from the list. */
657 	spin_lock(&c->lock);
658 	if (oldreq->status == REQ_STATUS_FLSH)
659 		list_del(&oldreq->req_list);
660 	spin_unlock(&c->lock);
661 
662 	p9_free_req(c, req);
663 	return 0;
664 }
665 
666 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
667 					      int8_t type, int req_size,
668 					      const char *fmt, va_list ap)
669 {
670 	int tag, err;
671 	struct p9_req_t *req;
672 
673 	P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
674 
675 	/* we allow for any status other than disconnected */
676 	if (c->status == Disconnected)
677 		return ERR_PTR(-EIO);
678 
679 	/* if status is begin_disconnected we allow only clunk request */
680 	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
681 		return ERR_PTR(-EIO);
682 
683 	tag = P9_NOTAG;
684 	if (type != P9_TVERSION) {
685 		tag = p9_idpool_get(c->tagpool);
686 		if (tag < 0)
687 			return ERR_PTR(-ENOMEM);
688 	}
689 
690 	req = p9_tag_alloc(c, tag, req_size);
691 	if (IS_ERR(req))
692 		return req;
693 
694 	/* marshall the data */
695 	p9pdu_prepare(req->tc, tag, type);
696 	err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
697 	if (err)
698 		goto reterr;
699 	p9pdu_finalize(c, req->tc);
700 	trace_9p_client_req(c, type, tag);
701 	return req;
702 reterr:
703 	p9_free_req(c, req);
704 	return ERR_PTR(err);
705 }
706 
707 /**
708  * p9_client_rpc - issue a request and wait for a response
709  * @c: client session
710  * @type: type of request
711  * @fmt: protocol format string (see protocol.c)
712  *
713  * Returns request structure (which client must free using p9_free_req)
714  */
715 
716 static struct p9_req_t *
717 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
718 {
719 	va_list ap;
720 	int sigpending, err;
721 	unsigned long flags;
722 	struct p9_req_t *req;
723 
724 	va_start(ap, fmt);
725 	req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
726 	va_end(ap);
727 	if (IS_ERR(req))
728 		return req;
729 
730 	if (signal_pending(current)) {
731 		sigpending = 1;
732 		clear_thread_flag(TIF_SIGPENDING);
733 	} else
734 		sigpending = 0;
735 
736 	err = c->trans_mod->request(c, req);
737 	if (err < 0) {
738 		if (err != -ERESTARTSYS && err != -EFAULT)
739 			c->status = Disconnected;
740 		goto reterr;
741 	}
742 	/* Wait for the response */
743 	err = wait_event_interruptible(*req->wq,
744 				       req->status >= REQ_STATUS_RCVD);
745 
746 	if (req->status == REQ_STATUS_ERROR) {
747 		P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
748 		err = req->t_err;
749 	}
750 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
751 		P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
752 		sigpending = 1;
753 		clear_thread_flag(TIF_SIGPENDING);
754 
755 		if (c->trans_mod->cancel(c, req))
756 			p9_client_flush(c, req);
757 
758 		/* if we received the response anyway, don't signal error */
759 		if (req->status == REQ_STATUS_RCVD)
760 			err = 0;
761 	}
762 	if (sigpending) {
763 		spin_lock_irqsave(&current->sighand->siglock, flags);
764 		recalc_sigpending();
765 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
766 	}
767 	if (err < 0)
768 		goto reterr;
769 
770 	err = p9_check_errors(c, req);
771 	trace_9p_client_res(c, type, req->rc->tag, err);
772 	if (!err)
773 		return req;
774 reterr:
775 	p9_free_req(c, req);
776 	return ERR_PTR(err);
777 }
778 
779 /**
780  * p9_client_zc_rpc - issue a request and wait for a response
781  * @c: client session
782  * @type: type of request
783  * @uidata: user bffer that should be ued for zero copy read
784  * @uodata: user buffer that shoud be user for zero copy write
785  * @inlen: read buffer size
786  * @olen: write buffer size
787  * @hdrlen: reader header size, This is the size of response protocol data
788  * @fmt: protocol format string (see protocol.c)
789  *
790  * Returns request structure (which client must free using p9_free_req)
791  */
792 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
793 					 char *uidata, char *uodata,
794 					 int inlen, int olen, int in_hdrlen,
795 					 int kern_buf, const char *fmt, ...)
796 {
797 	va_list ap;
798 	int sigpending, err;
799 	unsigned long flags;
800 	struct p9_req_t *req;
801 
802 	va_start(ap, fmt);
803 	/*
804 	 * We allocate a inline protocol data of only 4k bytes.
805 	 * The actual content is passed in zero-copy fashion.
806 	 */
807 	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
808 	va_end(ap);
809 	if (IS_ERR(req))
810 		return req;
811 
812 	if (signal_pending(current)) {
813 		sigpending = 1;
814 		clear_thread_flag(TIF_SIGPENDING);
815 	} else
816 		sigpending = 0;
817 
818 	/* If we are called with KERNEL_DS force kern_buf */
819 	if (segment_eq(get_fs(), KERNEL_DS))
820 		kern_buf = 1;
821 
822 	err = c->trans_mod->zc_request(c, req, uidata, uodata,
823 				       inlen, olen, in_hdrlen, kern_buf);
824 	if (err < 0) {
825 		if (err == -EIO)
826 			c->status = Disconnected;
827 		goto reterr;
828 	}
829 	if (req->status == REQ_STATUS_ERROR) {
830 		P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
831 		err = req->t_err;
832 	}
833 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
834 		P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
835 		sigpending = 1;
836 		clear_thread_flag(TIF_SIGPENDING);
837 
838 		if (c->trans_mod->cancel(c, req))
839 			p9_client_flush(c, req);
840 
841 		/* if we received the response anyway, don't signal error */
842 		if (req->status == REQ_STATUS_RCVD)
843 			err = 0;
844 	}
845 	if (sigpending) {
846 		spin_lock_irqsave(&current->sighand->siglock, flags);
847 		recalc_sigpending();
848 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
849 	}
850 	if (err < 0)
851 		goto reterr;
852 
853 	err = p9_check_zc_errors(c, req, uidata, in_hdrlen, kern_buf);
854 	trace_9p_client_res(c, type, req->rc->tag, err);
855 	if (!err)
856 		return req;
857 reterr:
858 	p9_free_req(c, req);
859 	return ERR_PTR(err);
860 }
861 
862 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
863 {
864 	int ret;
865 	struct p9_fid *fid;
866 	unsigned long flags;
867 
868 	P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
869 	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
870 	if (!fid)
871 		return ERR_PTR(-ENOMEM);
872 
873 	ret = p9_idpool_get(clnt->fidpool);
874 	if (ret < 0) {
875 		ret = -ENOSPC;
876 		goto error;
877 	}
878 	fid->fid = ret;
879 
880 	memset(&fid->qid, 0, sizeof(struct p9_qid));
881 	fid->mode = -1;
882 	fid->uid = current_fsuid();
883 	fid->clnt = clnt;
884 	fid->rdir = NULL;
885 	spin_lock_irqsave(&clnt->lock, flags);
886 	list_add(&fid->flist, &clnt->fidlist);
887 	spin_unlock_irqrestore(&clnt->lock, flags);
888 
889 	return fid;
890 
891 error:
892 	kfree(fid);
893 	return ERR_PTR(ret);
894 }
895 
896 static void p9_fid_destroy(struct p9_fid *fid)
897 {
898 	struct p9_client *clnt;
899 	unsigned long flags;
900 
901 	P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
902 	clnt = fid->clnt;
903 	p9_idpool_put(fid->fid, clnt->fidpool);
904 	spin_lock_irqsave(&clnt->lock, flags);
905 	list_del(&fid->flist);
906 	spin_unlock_irqrestore(&clnt->lock, flags);
907 	kfree(fid->rdir);
908 	kfree(fid);
909 }
910 
911 static int p9_client_version(struct p9_client *c)
912 {
913 	int err = 0;
914 	struct p9_req_t *req;
915 	char *version;
916 	int msize;
917 
918 	P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
919 						c->msize, c->proto_version);
920 
921 	switch (c->proto_version) {
922 	case p9_proto_2000L:
923 		req = p9_client_rpc(c, P9_TVERSION, "ds",
924 					c->msize, "9P2000.L");
925 		break;
926 	case p9_proto_2000u:
927 		req = p9_client_rpc(c, P9_TVERSION, "ds",
928 					c->msize, "9P2000.u");
929 		break;
930 	case p9_proto_legacy:
931 		req = p9_client_rpc(c, P9_TVERSION, "ds",
932 					c->msize, "9P2000");
933 		break;
934 	default:
935 		return -EINVAL;
936 		break;
937 	}
938 
939 	if (IS_ERR(req))
940 		return PTR_ERR(req);
941 
942 	err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
943 	if (err) {
944 		P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
945 		trace_9p_protocol_dump(c, req->rc);
946 		goto error;
947 	}
948 
949 	P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
950 	if (!strncmp(version, "9P2000.L", 8))
951 		c->proto_version = p9_proto_2000L;
952 	else if (!strncmp(version, "9P2000.u", 8))
953 		c->proto_version = p9_proto_2000u;
954 	else if (!strncmp(version, "9P2000", 6))
955 		c->proto_version = p9_proto_legacy;
956 	else {
957 		err = -EREMOTEIO;
958 		goto error;
959 	}
960 
961 	if (msize < c->msize)
962 		c->msize = msize;
963 
964 error:
965 	kfree(version);
966 	p9_free_req(c, req);
967 
968 	return err;
969 }
970 
971 struct p9_client *p9_client_create(const char *dev_name, char *options)
972 {
973 	int err;
974 	struct p9_client *clnt;
975 
976 	err = 0;
977 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
978 	if (!clnt)
979 		return ERR_PTR(-ENOMEM);
980 
981 	clnt->trans_mod = NULL;
982 	clnt->trans = NULL;
983 	spin_lock_init(&clnt->lock);
984 	INIT_LIST_HEAD(&clnt->fidlist);
985 
986 	err = p9_tag_init(clnt);
987 	if (err < 0)
988 		goto free_client;
989 
990 	err = parse_opts(options, clnt);
991 	if (err < 0)
992 		goto destroy_tagpool;
993 
994 	if (!clnt->trans_mod)
995 		clnt->trans_mod = v9fs_get_default_trans();
996 
997 	if (clnt->trans_mod == NULL) {
998 		err = -EPROTONOSUPPORT;
999 		P9_DPRINTK(P9_DEBUG_ERROR,
1000 				"No transport defined or default transport\n");
1001 		goto destroy_tagpool;
1002 	}
1003 
1004 	clnt->fidpool = p9_idpool_create();
1005 	if (IS_ERR(clnt->fidpool)) {
1006 		err = PTR_ERR(clnt->fidpool);
1007 		goto put_trans;
1008 	}
1009 
1010 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1011 		clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1012 
1013 	err = clnt->trans_mod->create(clnt, dev_name, options);
1014 	if (err)
1015 		goto destroy_fidpool;
1016 
1017 	if (clnt->msize > clnt->trans_mod->maxsize)
1018 		clnt->msize = clnt->trans_mod->maxsize;
1019 
1020 	err = p9_client_version(clnt);
1021 	if (err)
1022 		goto close_trans;
1023 
1024 	return clnt;
1025 
1026 close_trans:
1027 	clnt->trans_mod->close(clnt);
1028 destroy_fidpool:
1029 	p9_idpool_destroy(clnt->fidpool);
1030 put_trans:
1031 	v9fs_put_trans(clnt->trans_mod);
1032 destroy_tagpool:
1033 	p9_idpool_destroy(clnt->tagpool);
1034 free_client:
1035 	kfree(clnt);
1036 	return ERR_PTR(err);
1037 }
1038 EXPORT_SYMBOL(p9_client_create);
1039 
1040 void p9_client_destroy(struct p9_client *clnt)
1041 {
1042 	struct p9_fid *fid, *fidptr;
1043 
1044 	P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
1045 
1046 	if (clnt->trans_mod)
1047 		clnt->trans_mod->close(clnt);
1048 
1049 	v9fs_put_trans(clnt->trans_mod);
1050 
1051 	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1052 		printk(KERN_INFO "Found fid %d not clunked\n", fid->fid);
1053 		p9_fid_destroy(fid);
1054 	}
1055 
1056 	if (clnt->fidpool)
1057 		p9_idpool_destroy(clnt->fidpool);
1058 
1059 	p9_tag_cleanup(clnt);
1060 
1061 	kfree(clnt);
1062 }
1063 EXPORT_SYMBOL(p9_client_destroy);
1064 
1065 void p9_client_disconnect(struct p9_client *clnt)
1066 {
1067 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
1068 	clnt->status = Disconnected;
1069 }
1070 EXPORT_SYMBOL(p9_client_disconnect);
1071 
1072 void p9_client_begin_disconnect(struct p9_client *clnt)
1073 {
1074 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
1075 	clnt->status = BeginDisconnect;
1076 }
1077 EXPORT_SYMBOL(p9_client_begin_disconnect);
1078 
1079 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1080 	char *uname, u32 n_uname, char *aname)
1081 {
1082 	int err = 0;
1083 	struct p9_req_t *req;
1084 	struct p9_fid *fid;
1085 	struct p9_qid qid;
1086 
1087 
1088 	P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1089 		   afid ? afid->fid : -1, uname, aname);
1090 	fid = p9_fid_create(clnt);
1091 	if (IS_ERR(fid)) {
1092 		err = PTR_ERR(fid);
1093 		fid = NULL;
1094 		goto error;
1095 	}
1096 
1097 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
1098 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1099 	if (IS_ERR(req)) {
1100 		err = PTR_ERR(req);
1101 		goto error;
1102 	}
1103 
1104 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1105 	if (err) {
1106 		trace_9p_protocol_dump(clnt, req->rc);
1107 		p9_free_req(clnt, req);
1108 		goto error;
1109 	}
1110 
1111 	P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1112 					qid.type,
1113 					(unsigned long long)qid.path,
1114 					qid.version);
1115 
1116 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1117 
1118 	p9_free_req(clnt, req);
1119 	return fid;
1120 
1121 error:
1122 	if (fid)
1123 		p9_fid_destroy(fid);
1124 	return ERR_PTR(err);
1125 }
1126 EXPORT_SYMBOL(p9_client_attach);
1127 
1128 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1129 		char **wnames, int clone)
1130 {
1131 	int err;
1132 	struct p9_client *clnt;
1133 	struct p9_fid *fid;
1134 	struct p9_qid *wqids;
1135 	struct p9_req_t *req;
1136 	uint16_t nwqids, count;
1137 
1138 	err = 0;
1139 	wqids = NULL;
1140 	clnt = oldfid->clnt;
1141 	if (clone) {
1142 		fid = p9_fid_create(clnt);
1143 		if (IS_ERR(fid)) {
1144 			err = PTR_ERR(fid);
1145 			fid = NULL;
1146 			goto error;
1147 		}
1148 
1149 		fid->uid = oldfid->uid;
1150 	} else
1151 		fid = oldfid;
1152 
1153 
1154 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1155 		oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1156 
1157 	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1158 								nwname, wnames);
1159 	if (IS_ERR(req)) {
1160 		err = PTR_ERR(req);
1161 		goto error;
1162 	}
1163 
1164 	err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1165 	if (err) {
1166 		trace_9p_protocol_dump(clnt, req->rc);
1167 		p9_free_req(clnt, req);
1168 		goto clunk_fid;
1169 	}
1170 	p9_free_req(clnt, req);
1171 
1172 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1173 
1174 	if (nwqids != nwname) {
1175 		err = -ENOENT;
1176 		goto clunk_fid;
1177 	}
1178 
1179 	for (count = 0; count < nwqids; count++)
1180 		P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1181 			count, wqids[count].type,
1182 			(unsigned long long)wqids[count].path,
1183 			wqids[count].version);
1184 
1185 	if (nwname)
1186 		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1187 	else
1188 		fid->qid = oldfid->qid;
1189 
1190 	kfree(wqids);
1191 	return fid;
1192 
1193 clunk_fid:
1194 	kfree(wqids);
1195 	p9_client_clunk(fid);
1196 	fid = NULL;
1197 
1198 error:
1199 	if (fid && (fid != oldfid))
1200 		p9_fid_destroy(fid);
1201 
1202 	return ERR_PTR(err);
1203 }
1204 EXPORT_SYMBOL(p9_client_walk);
1205 
1206 int p9_client_open(struct p9_fid *fid, int mode)
1207 {
1208 	int err;
1209 	struct p9_client *clnt;
1210 	struct p9_req_t *req;
1211 	struct p9_qid qid;
1212 	int iounit;
1213 
1214 	clnt = fid->clnt;
1215 	P9_DPRINTK(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1216 		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1217 	err = 0;
1218 
1219 	if (fid->mode != -1)
1220 		return -EINVAL;
1221 
1222 	if (p9_is_proto_dotl(clnt))
1223 		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1224 	else
1225 		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1226 	if (IS_ERR(req)) {
1227 		err = PTR_ERR(req);
1228 		goto error;
1229 	}
1230 
1231 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1232 	if (err) {
1233 		trace_9p_protocol_dump(clnt, req->rc);
1234 		goto free_and_error;
1235 	}
1236 
1237 	P9_DPRINTK(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1238 		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1239 		(unsigned long long)qid.path, qid.version, iounit);
1240 
1241 	fid->mode = mode;
1242 	fid->iounit = iounit;
1243 
1244 free_and_error:
1245 	p9_free_req(clnt, req);
1246 error:
1247 	return err;
1248 }
1249 EXPORT_SYMBOL(p9_client_open);
1250 
1251 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1252 		gid_t gid, struct p9_qid *qid)
1253 {
1254 	int err = 0;
1255 	struct p9_client *clnt;
1256 	struct p9_req_t *req;
1257 	int iounit;
1258 
1259 	P9_DPRINTK(P9_DEBUG_9P,
1260 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1261 			ofid->fid, name, flags, mode, gid);
1262 	clnt = ofid->clnt;
1263 
1264 	if (ofid->mode != -1)
1265 		return -EINVAL;
1266 
1267 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddd", ofid->fid, name, flags,
1268 			mode, gid);
1269 	if (IS_ERR(req)) {
1270 		err = PTR_ERR(req);
1271 		goto error;
1272 	}
1273 
1274 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1275 	if (err) {
1276 		trace_9p_protocol_dump(clnt, req->rc);
1277 		goto free_and_error;
1278 	}
1279 
1280 	P9_DPRINTK(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1281 			qid->type,
1282 			(unsigned long long)qid->path,
1283 			qid->version, iounit);
1284 
1285 	ofid->mode = mode;
1286 	ofid->iounit = iounit;
1287 
1288 free_and_error:
1289 	p9_free_req(clnt, req);
1290 error:
1291 	return err;
1292 }
1293 EXPORT_SYMBOL(p9_client_create_dotl);
1294 
1295 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1296 		     char *extension)
1297 {
1298 	int err;
1299 	struct p9_client *clnt;
1300 	struct p9_req_t *req;
1301 	struct p9_qid qid;
1302 	int iounit;
1303 
1304 	P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1305 						fid->fid, name, perm, mode);
1306 	err = 0;
1307 	clnt = fid->clnt;
1308 
1309 	if (fid->mode != -1)
1310 		return -EINVAL;
1311 
1312 	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1313 				mode, extension);
1314 	if (IS_ERR(req)) {
1315 		err = PTR_ERR(req);
1316 		goto error;
1317 	}
1318 
1319 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1320 	if (err) {
1321 		trace_9p_protocol_dump(clnt, req->rc);
1322 		goto free_and_error;
1323 	}
1324 
1325 	P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1326 				qid.type,
1327 				(unsigned long long)qid.path,
1328 				qid.version, iounit);
1329 
1330 	fid->mode = mode;
1331 	fid->iounit = iounit;
1332 
1333 free_and_error:
1334 	p9_free_req(clnt, req);
1335 error:
1336 	return err;
1337 }
1338 EXPORT_SYMBOL(p9_client_fcreate);
1339 
1340 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
1341 		struct p9_qid *qid)
1342 {
1343 	int err = 0;
1344 	struct p9_client *clnt;
1345 	struct p9_req_t *req;
1346 
1347 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1348 			dfid->fid, name, symtgt);
1349 	clnt = dfid->clnt;
1350 
1351 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssd", dfid->fid, name, symtgt,
1352 			gid);
1353 	if (IS_ERR(req)) {
1354 		err = PTR_ERR(req);
1355 		goto error;
1356 	}
1357 
1358 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1359 	if (err) {
1360 		trace_9p_protocol_dump(clnt, req->rc);
1361 		goto free_and_error;
1362 	}
1363 
1364 	P9_DPRINTK(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1365 			qid->type, (unsigned long long)qid->path, qid->version);
1366 
1367 free_and_error:
1368 	p9_free_req(clnt, req);
1369 error:
1370 	return err;
1371 }
1372 EXPORT_SYMBOL(p9_client_symlink);
1373 
1374 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1375 {
1376 	struct p9_client *clnt;
1377 	struct p9_req_t *req;
1378 
1379 	P9_DPRINTK(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1380 			dfid->fid, oldfid->fid, newname);
1381 	clnt = dfid->clnt;
1382 	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1383 			newname);
1384 	if (IS_ERR(req))
1385 		return PTR_ERR(req);
1386 
1387 	P9_DPRINTK(P9_DEBUG_9P, "<<< RLINK\n");
1388 	p9_free_req(clnt, req);
1389 	return 0;
1390 }
1391 EXPORT_SYMBOL(p9_client_link);
1392 
1393 int p9_client_fsync(struct p9_fid *fid, int datasync)
1394 {
1395 	int err;
1396 	struct p9_client *clnt;
1397 	struct p9_req_t *req;
1398 
1399 	P9_DPRINTK(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1400 			fid->fid, datasync);
1401 	err = 0;
1402 	clnt = fid->clnt;
1403 
1404 	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1405 	if (IS_ERR(req)) {
1406 		err = PTR_ERR(req);
1407 		goto error;
1408 	}
1409 
1410 	P9_DPRINTK(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1411 
1412 	p9_free_req(clnt, req);
1413 
1414 error:
1415 	return err;
1416 }
1417 EXPORT_SYMBOL(p9_client_fsync);
1418 
1419 int p9_client_clunk(struct p9_fid *fid)
1420 {
1421 	int err;
1422 	struct p9_client *clnt;
1423 	struct p9_req_t *req;
1424 
1425 	if (!fid) {
1426 		P9_EPRINTK(KERN_WARNING, "Trying to clunk with NULL fid\n");
1427 		dump_stack();
1428 		return 0;
1429 	}
1430 
1431 	P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1432 	err = 0;
1433 	clnt = fid->clnt;
1434 
1435 	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1436 	if (IS_ERR(req)) {
1437 		err = PTR_ERR(req);
1438 		goto error;
1439 	}
1440 
1441 	P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1442 
1443 	p9_free_req(clnt, req);
1444 error:
1445 	/*
1446 	 * Fid is not valid even after a failed clunk
1447 	 */
1448 	p9_fid_destroy(fid);
1449 	return err;
1450 }
1451 EXPORT_SYMBOL(p9_client_clunk);
1452 
1453 int p9_client_remove(struct p9_fid *fid)
1454 {
1455 	int err;
1456 	struct p9_client *clnt;
1457 	struct p9_req_t *req;
1458 
1459 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1460 	err = 0;
1461 	clnt = fid->clnt;
1462 
1463 	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1464 	if (IS_ERR(req)) {
1465 		err = PTR_ERR(req);
1466 		goto error;
1467 	}
1468 
1469 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1470 
1471 	p9_free_req(clnt, req);
1472 error:
1473 	p9_fid_destroy(fid);
1474 	return err;
1475 }
1476 EXPORT_SYMBOL(p9_client_remove);
1477 
1478 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1479 {
1480 	int err = 0;
1481 	struct p9_req_t *req;
1482 	struct p9_client *clnt;
1483 
1484 	P9_DPRINTK(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1485 		   dfid->fid, name, flags);
1486 
1487 	clnt = dfid->clnt;
1488 	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1489 	if (IS_ERR(req)) {
1490 		err = PTR_ERR(req);
1491 		goto error;
1492 	}
1493 	P9_DPRINTK(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1494 
1495 	p9_free_req(clnt, req);
1496 error:
1497 	return err;
1498 }
1499 EXPORT_SYMBOL(p9_client_unlinkat);
1500 
1501 int
1502 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1503 								u32 count)
1504 {
1505 	char *dataptr;
1506 	int kernel_buf = 0;
1507 	struct p9_req_t *req;
1508 	struct p9_client *clnt;
1509 	int err, rsize, non_zc = 0;
1510 
1511 
1512 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1513 		   fid->fid, (long long unsigned) offset, count);
1514 	err = 0;
1515 	clnt = fid->clnt;
1516 
1517 	rsize = fid->iounit;
1518 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1519 		rsize = clnt->msize - P9_IOHDRSZ;
1520 
1521 	if (count < rsize)
1522 		rsize = count;
1523 
1524 	/* Don't bother zerocopy for small IO (< 1024) */
1525 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1526 		char *indata;
1527 		if (data) {
1528 			kernel_buf = 1;
1529 			indata = data;
1530 		} else
1531 			indata = (char *)udata;
1532 		/*
1533 		 * response header len is 11
1534 		 * PDU Header(7) + IO Size (4)
1535 		 */
1536 		req = p9_client_zc_rpc(clnt, P9_TREAD, indata, NULL, rsize, 0,
1537 				       11, kernel_buf, "dqd", fid->fid,
1538 				       offset, rsize);
1539 	} else {
1540 		non_zc = 1;
1541 		req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1542 				    rsize);
1543 	}
1544 	if (IS_ERR(req)) {
1545 		err = PTR_ERR(req);
1546 		goto error;
1547 	}
1548 
1549 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1550 	if (err) {
1551 		trace_9p_protocol_dump(clnt, req->rc);
1552 		goto free_and_error;
1553 	}
1554 
1555 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1556 
1557 	if (non_zc) {
1558 		if (data) {
1559 			memmove(data, dataptr, count);
1560 		} else {
1561 			err = copy_to_user(udata, dataptr, count);
1562 			if (err) {
1563 				err = -EFAULT;
1564 				goto free_and_error;
1565 			}
1566 		}
1567 	}
1568 	p9_free_req(clnt, req);
1569 	return count;
1570 
1571 free_and_error:
1572 	p9_free_req(clnt, req);
1573 error:
1574 	return err;
1575 }
1576 EXPORT_SYMBOL(p9_client_read);
1577 
1578 int
1579 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1580 							u64 offset, u32 count)
1581 {
1582 	int err, rsize;
1583 	int kernel_buf = 0;
1584 	struct p9_client *clnt;
1585 	struct p9_req_t *req;
1586 
1587 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1588 				fid->fid, (long long unsigned) offset, count);
1589 	err = 0;
1590 	clnt = fid->clnt;
1591 
1592 	rsize = fid->iounit;
1593 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1594 		rsize = clnt->msize - P9_IOHDRSZ;
1595 
1596 	if (count < rsize)
1597 		rsize = count;
1598 
1599 	/* Don't bother zerocopy for small IO (< 1024) */
1600 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1601 		char *odata;
1602 		if (data) {
1603 			kernel_buf = 1;
1604 			odata = data;
1605 		} else
1606 			odata = (char *)udata;
1607 		req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, odata, 0, rsize,
1608 				       P9_ZC_HDR_SZ, kernel_buf, "dqd",
1609 				       fid->fid, offset, rsize);
1610 	} else {
1611 		if (data)
1612 			req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1613 					    offset, rsize, data);
1614 		else
1615 			req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1616 					    offset, rsize, udata);
1617 	}
1618 	if (IS_ERR(req)) {
1619 		err = PTR_ERR(req);
1620 		goto error;
1621 	}
1622 
1623 	err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1624 	if (err) {
1625 		trace_9p_protocol_dump(clnt, req->rc);
1626 		goto free_and_error;
1627 	}
1628 
1629 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1630 
1631 	p9_free_req(clnt, req);
1632 	return count;
1633 
1634 free_and_error:
1635 	p9_free_req(clnt, req);
1636 error:
1637 	return err;
1638 }
1639 EXPORT_SYMBOL(p9_client_write);
1640 
1641 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1642 {
1643 	int err;
1644 	struct p9_client *clnt;
1645 	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1646 	struct p9_req_t *req;
1647 	u16 ignored;
1648 
1649 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1650 
1651 	if (!ret)
1652 		return ERR_PTR(-ENOMEM);
1653 
1654 	err = 0;
1655 	clnt = fid->clnt;
1656 
1657 	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1658 	if (IS_ERR(req)) {
1659 		err = PTR_ERR(req);
1660 		goto error;
1661 	}
1662 
1663 	err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1664 	if (err) {
1665 		trace_9p_protocol_dump(clnt, req->rc);
1666 		p9_free_req(clnt, req);
1667 		goto error;
1668 	}
1669 
1670 	P9_DPRINTK(P9_DEBUG_9P,
1671 		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1672 		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1673 		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1674 		"<<<    uid=%d gid=%d n_muid=%d\n",
1675 		ret->size, ret->type, ret->dev, ret->qid.type,
1676 		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1677 		ret->atime, ret->mtime, (unsigned long long)ret->length,
1678 		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1679 		ret->n_uid, ret->n_gid, ret->n_muid);
1680 
1681 	p9_free_req(clnt, req);
1682 	return ret;
1683 
1684 error:
1685 	kfree(ret);
1686 	return ERR_PTR(err);
1687 }
1688 EXPORT_SYMBOL(p9_client_stat);
1689 
1690 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1691 							u64 request_mask)
1692 {
1693 	int err;
1694 	struct p9_client *clnt;
1695 	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1696 								GFP_KERNEL);
1697 	struct p9_req_t *req;
1698 
1699 	P9_DPRINTK(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1700 							fid->fid, request_mask);
1701 
1702 	if (!ret)
1703 		return ERR_PTR(-ENOMEM);
1704 
1705 	err = 0;
1706 	clnt = fid->clnt;
1707 
1708 	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1709 	if (IS_ERR(req)) {
1710 		err = PTR_ERR(req);
1711 		goto error;
1712 	}
1713 
1714 	err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1715 	if (err) {
1716 		trace_9p_protocol_dump(clnt, req->rc);
1717 		p9_free_req(clnt, req);
1718 		goto error;
1719 	}
1720 
1721 	P9_DPRINTK(P9_DEBUG_9P,
1722 		"<<< RGETATTR st_result_mask=%lld\n"
1723 		"<<< qid=%x.%llx.%x\n"
1724 		"<<< st_mode=%8.8x st_nlink=%llu\n"
1725 		"<<< st_uid=%d st_gid=%d\n"
1726 		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1727 		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1728 		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1729 		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1730 		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1731 		"<<< st_gen=%lld st_data_version=%lld",
1732 		ret->st_result_mask, ret->qid.type, ret->qid.path,
1733 		ret->qid.version, ret->st_mode, ret->st_nlink, ret->st_uid,
1734 		ret->st_gid, ret->st_rdev, ret->st_size, ret->st_blksize,
1735 		ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1736 		ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1737 		ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1738 		ret->st_gen, ret->st_data_version);
1739 
1740 	p9_free_req(clnt, req);
1741 	return ret;
1742 
1743 error:
1744 	kfree(ret);
1745 	return ERR_PTR(err);
1746 }
1747 EXPORT_SYMBOL(p9_client_getattr_dotl);
1748 
1749 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1750 {
1751 	int ret;
1752 
1753 	/* NOTE: size shouldn't include its own length */
1754 	/* size[2] type[2] dev[4] qid[13] */
1755 	/* mode[4] atime[4] mtime[4] length[8]*/
1756 	/* name[s] uid[s] gid[s] muid[s] */
1757 	ret = 2+4+13+4+4+4+8+2+2+2+2;
1758 
1759 	if (wst->name)
1760 		ret += strlen(wst->name);
1761 	if (wst->uid)
1762 		ret += strlen(wst->uid);
1763 	if (wst->gid)
1764 		ret += strlen(wst->gid);
1765 	if (wst->muid)
1766 		ret += strlen(wst->muid);
1767 
1768 	if ((proto_version == p9_proto_2000u) ||
1769 		(proto_version == p9_proto_2000L)) {
1770 		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1771 		if (wst->extension)
1772 			ret += strlen(wst->extension);
1773 	}
1774 
1775 	return ret;
1776 }
1777 
1778 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1779 {
1780 	int err;
1781 	struct p9_req_t *req;
1782 	struct p9_client *clnt;
1783 
1784 	err = 0;
1785 	clnt = fid->clnt;
1786 	wst->size = p9_client_statsize(wst, clnt->proto_version);
1787 	P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1788 	P9_DPRINTK(P9_DEBUG_9P,
1789 		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1790 		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1791 		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1792 		"     uid=%d gid=%d n_muid=%d\n",
1793 		wst->size, wst->type, wst->dev, wst->qid.type,
1794 		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1795 		wst->atime, wst->mtime, (unsigned long long)wst->length,
1796 		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1797 		wst->n_uid, wst->n_gid, wst->n_muid);
1798 
1799 	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1800 	if (IS_ERR(req)) {
1801 		err = PTR_ERR(req);
1802 		goto error;
1803 	}
1804 
1805 	P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1806 
1807 	p9_free_req(clnt, req);
1808 error:
1809 	return err;
1810 }
1811 EXPORT_SYMBOL(p9_client_wstat);
1812 
1813 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1814 {
1815 	int err;
1816 	struct p9_req_t *req;
1817 	struct p9_client *clnt;
1818 
1819 	err = 0;
1820 	clnt = fid->clnt;
1821 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1822 	P9_DPRINTK(P9_DEBUG_9P,
1823 		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1824 		"    atime_sec=%lld atime_nsec=%lld\n"
1825 		"    mtime_sec=%lld mtime_nsec=%lld\n",
1826 		p9attr->valid, p9attr->mode, p9attr->uid, p9attr->gid,
1827 		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1828 		p9attr->mtime_sec, p9attr->mtime_nsec);
1829 
1830 	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1831 
1832 	if (IS_ERR(req)) {
1833 		err = PTR_ERR(req);
1834 		goto error;
1835 	}
1836 	P9_DPRINTK(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1837 	p9_free_req(clnt, req);
1838 error:
1839 	return err;
1840 }
1841 EXPORT_SYMBOL(p9_client_setattr);
1842 
1843 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1844 {
1845 	int err;
1846 	struct p9_req_t *req;
1847 	struct p9_client *clnt;
1848 
1849 	err = 0;
1850 	clnt = fid->clnt;
1851 
1852 	P9_DPRINTK(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1853 
1854 	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1855 	if (IS_ERR(req)) {
1856 		err = PTR_ERR(req);
1857 		goto error;
1858 	}
1859 
1860 	err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1861 		&sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1862 		&sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1863 	if (err) {
1864 		trace_9p_protocol_dump(clnt, req->rc);
1865 		p9_free_req(clnt, req);
1866 		goto error;
1867 	}
1868 
1869 	P9_DPRINTK(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1870 		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1871 		"fsid %llu namelen %ld\n",
1872 		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1873 		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1874 		sb->fsid, (long int)sb->namelen);
1875 
1876 	p9_free_req(clnt, req);
1877 error:
1878 	return err;
1879 }
1880 EXPORT_SYMBOL(p9_client_statfs);
1881 
1882 int p9_client_rename(struct p9_fid *fid,
1883 		     struct p9_fid *newdirfid, const char *name)
1884 {
1885 	int err;
1886 	struct p9_req_t *req;
1887 	struct p9_client *clnt;
1888 
1889 	err = 0;
1890 	clnt = fid->clnt;
1891 
1892 	P9_DPRINTK(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1893 			fid->fid, newdirfid->fid, name);
1894 
1895 	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1896 			newdirfid->fid, name);
1897 	if (IS_ERR(req)) {
1898 		err = PTR_ERR(req);
1899 		goto error;
1900 	}
1901 
1902 	P9_DPRINTK(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1903 
1904 	p9_free_req(clnt, req);
1905 error:
1906 	return err;
1907 }
1908 EXPORT_SYMBOL(p9_client_rename);
1909 
1910 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1911 		       struct p9_fid *newdirfid, const char *new_name)
1912 {
1913 	int err;
1914 	struct p9_req_t *req;
1915 	struct p9_client *clnt;
1916 
1917 	err = 0;
1918 	clnt = olddirfid->clnt;
1919 
1920 	P9_DPRINTK(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1921 		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1922 		   newdirfid->fid, new_name);
1923 
1924 	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1925 			    old_name, newdirfid->fid, new_name);
1926 	if (IS_ERR(req)) {
1927 		err = PTR_ERR(req);
1928 		goto error;
1929 	}
1930 
1931 	P9_DPRINTK(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1932 		   newdirfid->fid, new_name);
1933 
1934 	p9_free_req(clnt, req);
1935 error:
1936 	return err;
1937 }
1938 EXPORT_SYMBOL(p9_client_renameat);
1939 
1940 /*
1941  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1942  */
1943 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1944 				const char *attr_name, u64 *attr_size)
1945 {
1946 	int err;
1947 	struct p9_req_t *req;
1948 	struct p9_client *clnt;
1949 	struct p9_fid *attr_fid;
1950 
1951 	err = 0;
1952 	clnt = file_fid->clnt;
1953 	attr_fid = p9_fid_create(clnt);
1954 	if (IS_ERR(attr_fid)) {
1955 		err = PTR_ERR(attr_fid);
1956 		attr_fid = NULL;
1957 		goto error;
1958 	}
1959 	P9_DPRINTK(P9_DEBUG_9P,
1960 		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1961 		file_fid->fid, attr_fid->fid, attr_name);
1962 
1963 	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1964 			file_fid->fid, attr_fid->fid, attr_name);
1965 	if (IS_ERR(req)) {
1966 		err = PTR_ERR(req);
1967 		goto error;
1968 	}
1969 	err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
1970 	if (err) {
1971 		trace_9p_protocol_dump(clnt, req->rc);
1972 		p9_free_req(clnt, req);
1973 		goto clunk_fid;
1974 	}
1975 	p9_free_req(clnt, req);
1976 	P9_DPRINTK(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
1977 		attr_fid->fid, *attr_size);
1978 	return attr_fid;
1979 clunk_fid:
1980 	p9_client_clunk(attr_fid);
1981 	attr_fid = NULL;
1982 error:
1983 	if (attr_fid && (attr_fid != file_fid))
1984 		p9_fid_destroy(attr_fid);
1985 
1986 	return ERR_PTR(err);
1987 }
1988 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
1989 
1990 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
1991 			u64 attr_size, int flags)
1992 {
1993 	int err;
1994 	struct p9_req_t *req;
1995 	struct p9_client *clnt;
1996 
1997 	P9_DPRINTK(P9_DEBUG_9P,
1998 		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
1999 		fid->fid, name, (long long)attr_size, flags);
2000 	err = 0;
2001 	clnt = fid->clnt;
2002 	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2003 			fid->fid, name, attr_size, flags);
2004 	if (IS_ERR(req)) {
2005 		err = PTR_ERR(req);
2006 		goto error;
2007 	}
2008 	P9_DPRINTK(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2009 	p9_free_req(clnt, req);
2010 error:
2011 	return err;
2012 }
2013 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2014 
2015 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2016 {
2017 	int err, rsize, non_zc = 0;
2018 	struct p9_client *clnt;
2019 	struct p9_req_t *req;
2020 	char *dataptr;
2021 
2022 	P9_DPRINTK(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2023 				fid->fid, (long long unsigned) offset, count);
2024 
2025 	err = 0;
2026 	clnt = fid->clnt;
2027 
2028 	rsize = fid->iounit;
2029 	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2030 		rsize = clnt->msize - P9_READDIRHDRSZ;
2031 
2032 	if (count < rsize)
2033 		rsize = count;
2034 
2035 	/* Don't bother zerocopy for small IO (< 1024) */
2036 	if (clnt->trans_mod->zc_request && rsize > 1024) {
2037 		/*
2038 		 * response header len is 11
2039 		 * PDU Header(7) + IO Size (4)
2040 		 */
2041 		req = p9_client_zc_rpc(clnt, P9_TREADDIR, data, NULL, rsize, 0,
2042 				       11, 1, "dqd", fid->fid, offset, rsize);
2043 	} else {
2044 		non_zc = 1;
2045 		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2046 				    offset, rsize);
2047 	}
2048 	if (IS_ERR(req)) {
2049 		err = PTR_ERR(req);
2050 		goto error;
2051 	}
2052 
2053 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2054 	if (err) {
2055 		trace_9p_protocol_dump(clnt, req->rc);
2056 		goto free_and_error;
2057 	}
2058 
2059 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2060 
2061 	if (non_zc)
2062 		memmove(data, dataptr, count);
2063 
2064 	p9_free_req(clnt, req);
2065 	return count;
2066 
2067 free_and_error:
2068 	p9_free_req(clnt, req);
2069 error:
2070 	return err;
2071 }
2072 EXPORT_SYMBOL(p9_client_readdir);
2073 
2074 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2075 			dev_t rdev, gid_t gid, struct p9_qid *qid)
2076 {
2077 	int err;
2078 	struct p9_client *clnt;
2079 	struct p9_req_t *req;
2080 
2081 	err = 0;
2082 	clnt = fid->clnt;
2083 	P9_DPRINTK(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2084 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2085 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddd", fid->fid, name, mode,
2086 		MAJOR(rdev), MINOR(rdev), gid);
2087 	if (IS_ERR(req))
2088 		return PTR_ERR(req);
2089 
2090 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2091 	if (err) {
2092 		trace_9p_protocol_dump(clnt, req->rc);
2093 		goto error;
2094 	}
2095 	P9_DPRINTK(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2096 				(unsigned long long)qid->path, qid->version);
2097 
2098 error:
2099 	p9_free_req(clnt, req);
2100 	return err;
2101 
2102 }
2103 EXPORT_SYMBOL(p9_client_mknod_dotl);
2104 
2105 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2106 				gid_t gid, struct p9_qid *qid)
2107 {
2108 	int err;
2109 	struct p9_client *clnt;
2110 	struct p9_req_t *req;
2111 
2112 	err = 0;
2113 	clnt = fid->clnt;
2114 	P9_DPRINTK(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2115 		 fid->fid, name, mode, gid);
2116 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdd", fid->fid, name, mode,
2117 		gid);
2118 	if (IS_ERR(req))
2119 		return PTR_ERR(req);
2120 
2121 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2122 	if (err) {
2123 		trace_9p_protocol_dump(clnt, req->rc);
2124 		goto error;
2125 	}
2126 	P9_DPRINTK(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2127 				(unsigned long long)qid->path, qid->version);
2128 
2129 error:
2130 	p9_free_req(clnt, req);
2131 	return err;
2132 
2133 }
2134 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2135 
2136 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2137 {
2138 	int err;
2139 	struct p9_client *clnt;
2140 	struct p9_req_t *req;
2141 
2142 	err = 0;
2143 	clnt = fid->clnt;
2144 	P9_DPRINTK(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2145 			"start %lld length %lld proc_id %d client_id %s\n",
2146 			fid->fid, flock->type, flock->flags, flock->start,
2147 			flock->length, flock->proc_id, flock->client_id);
2148 
2149 	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2150 				flock->flags, flock->start, flock->length,
2151 					flock->proc_id, flock->client_id);
2152 
2153 	if (IS_ERR(req))
2154 		return PTR_ERR(req);
2155 
2156 	err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2157 	if (err) {
2158 		trace_9p_protocol_dump(clnt, req->rc);
2159 		goto error;
2160 	}
2161 	P9_DPRINTK(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2162 error:
2163 	p9_free_req(clnt, req);
2164 	return err;
2165 
2166 }
2167 EXPORT_SYMBOL(p9_client_lock_dotl);
2168 
2169 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2170 {
2171 	int err;
2172 	struct p9_client *clnt;
2173 	struct p9_req_t *req;
2174 
2175 	err = 0;
2176 	clnt = fid->clnt;
2177 	P9_DPRINTK(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2178 		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2179 		glock->start, glock->length, glock->proc_id, glock->client_id);
2180 
2181 	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2182 		glock->start, glock->length, glock->proc_id, glock->client_id);
2183 
2184 	if (IS_ERR(req))
2185 		return PTR_ERR(req);
2186 
2187 	err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2188 			&glock->start, &glock->length, &glock->proc_id,
2189 			&glock->client_id);
2190 	if (err) {
2191 		trace_9p_protocol_dump(clnt, req->rc);
2192 		goto error;
2193 	}
2194 	P9_DPRINTK(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2195 		"proc_id %d client_id %s\n", glock->type, glock->start,
2196 		glock->length, glock->proc_id, glock->client_id);
2197 error:
2198 	p9_free_req(clnt, req);
2199 	return err;
2200 }
2201 EXPORT_SYMBOL(p9_client_getlock_dotl);
2202 
2203 int p9_client_readlink(struct p9_fid *fid, char **target)
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_DPRINTK(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2212 
2213 	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2214 	if (IS_ERR(req))
2215 		return PTR_ERR(req);
2216 
2217 	err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2218 	if (err) {
2219 		trace_9p_protocol_dump(clnt, req->rc);
2220 		goto error;
2221 	}
2222 	P9_DPRINTK(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2223 error:
2224 	p9_free_req(clnt, req);
2225 	return err;
2226 }
2227 EXPORT_SYMBOL(p9_client_readlink);
2228