xref: /linux/net/9p/client.c (revision 4d7696f1b05f4aeb586c74868fe3da2731daca4b)
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_2000L;
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 struct p9_fcall *p9_fcall_alloc(int alloc_msize)
208 {
209 	struct p9_fcall *fc;
210 	fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
211 	if (!fc)
212 		return NULL;
213 	fc->capacity = alloc_msize;
214 	fc->sdata = (char *) fc + sizeof(struct p9_fcall);
215 	return fc;
216 }
217 
218 /**
219  * p9_tag_alloc - lookup/allocate a request by tag
220  * @c: client session to lookup tag within
221  * @tag: numeric id for transaction
222  *
223  * this is a simple array lookup, but will grow the
224  * request_slots as necessary to accommodate transaction
225  * ids which did not previously have a slot.
226  *
227  * this code relies on the client spinlock to manage locks, its
228  * possible we should switch to something else, but I'd rather
229  * stick with something low-overhead for the common case.
230  *
231  */
232 
233 static struct p9_req_t *
234 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
235 {
236 	unsigned long flags;
237 	int row, col;
238 	struct p9_req_t *req;
239 	int alloc_msize = min(c->msize, max_size);
240 
241 	/* This looks up the original request by tag so we know which
242 	 * buffer to read the data into */
243 	tag++;
244 
245 	if (tag >= c->max_tag) {
246 		spin_lock_irqsave(&c->lock, flags);
247 		/* check again since original check was outside of lock */
248 		while (tag >= c->max_tag) {
249 			row = (tag / P9_ROW_MAXTAG);
250 			c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
251 					sizeof(struct p9_req_t), GFP_ATOMIC);
252 
253 			if (!c->reqs[row]) {
254 				pr_err("Couldn't grow tag array\n");
255 				spin_unlock_irqrestore(&c->lock, flags);
256 				return ERR_PTR(-ENOMEM);
257 			}
258 			for (col = 0; col < P9_ROW_MAXTAG; col++) {
259 				c->reqs[row][col].status = REQ_STATUS_IDLE;
260 				c->reqs[row][col].tc = NULL;
261 			}
262 			c->max_tag += P9_ROW_MAXTAG;
263 		}
264 		spin_unlock_irqrestore(&c->lock, flags);
265 	}
266 	row = tag / P9_ROW_MAXTAG;
267 	col = tag % P9_ROW_MAXTAG;
268 
269 	req = &c->reqs[row][col];
270 	if (!req->wq) {
271 		req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
272 		if (!req->wq)
273 			goto grow_failed;
274 		init_waitqueue_head(req->wq);
275 	}
276 
277 	if (!req->tc)
278 		req->tc = p9_fcall_alloc(alloc_msize);
279 	if (!req->rc)
280 		req->rc = p9_fcall_alloc(alloc_msize);
281 	if (!req->tc || !req->rc)
282 		goto grow_failed;
283 
284 	p9pdu_reset(req->tc);
285 	p9pdu_reset(req->rc);
286 
287 	req->tc->tag = tag-1;
288 	req->status = REQ_STATUS_ALLOC;
289 
290 	return req;
291 
292 grow_failed:
293 	pr_err("Couldn't grow tag array\n");
294 	kfree(req->tc);
295 	kfree(req->rc);
296 	kfree(req->wq);
297 	req->tc = req->rc = NULL;
298 	req->wq = NULL;
299 	return ERR_PTR(-ENOMEM);
300 }
301 
302 /**
303  * p9_tag_lookup - lookup a request by tag
304  * @c: client session to lookup tag within
305  * @tag: numeric id for transaction
306  *
307  */
308 
309 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
310 {
311 	int row, col;
312 
313 	/* This looks up the original request by tag so we know which
314 	 * buffer to read the data into */
315 	tag++;
316 
317 	if(tag >= c->max_tag)
318 		return NULL;
319 
320 	row = tag / P9_ROW_MAXTAG;
321 	col = tag % P9_ROW_MAXTAG;
322 
323 	return &c->reqs[row][col];
324 }
325 EXPORT_SYMBOL(p9_tag_lookup);
326 
327 /**
328  * p9_tag_init - setup tags structure and contents
329  * @c:  v9fs client struct
330  *
331  * This initializes the tags structure for each client instance.
332  *
333  */
334 
335 static int p9_tag_init(struct p9_client *c)
336 {
337 	int err = 0;
338 
339 	c->tagpool = p9_idpool_create();
340 	if (IS_ERR(c->tagpool)) {
341 		err = PTR_ERR(c->tagpool);
342 		goto error;
343 	}
344 	err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
345 	if (err < 0) {
346 		p9_idpool_destroy(c->tagpool);
347 		goto error;
348 	}
349 	c->max_tag = 0;
350 error:
351 	return err;
352 }
353 
354 /**
355  * p9_tag_cleanup - cleans up tags structure and reclaims resources
356  * @c:  v9fs client struct
357  *
358  * This frees resources associated with the tags structure
359  *
360  */
361 static void p9_tag_cleanup(struct p9_client *c)
362 {
363 	int row, col;
364 
365 	/* check to insure all requests are idle */
366 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
367 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
368 			if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
369 				p9_debug(P9_DEBUG_MUX,
370 					 "Attempting to cleanup non-free tag %d,%d\n",
371 					 row, col);
372 				/* TODO: delay execution of cleanup */
373 				return;
374 			}
375 		}
376 	}
377 
378 	if (c->tagpool) {
379 		p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
380 		p9_idpool_destroy(c->tagpool);
381 	}
382 
383 	/* free requests associated with tags */
384 	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
385 		for (col = 0; col < P9_ROW_MAXTAG; col++) {
386 			kfree(c->reqs[row][col].wq);
387 			kfree(c->reqs[row][col].tc);
388 			kfree(c->reqs[row][col].rc);
389 		}
390 		kfree(c->reqs[row]);
391 	}
392 	c->max_tag = 0;
393 }
394 
395 /**
396  * p9_free_req - free a request and clean-up as necessary
397  * c: client state
398  * r: request to release
399  *
400  */
401 
402 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
403 {
404 	int tag = r->tc->tag;
405 	p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
406 
407 	r->status = REQ_STATUS_IDLE;
408 	if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
409 		p9_idpool_put(tag, c->tagpool);
410 }
411 
412 /**
413  * p9_client_cb - call back from transport to client
414  * c: client state
415  * req: request received
416  *
417  */
418 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
419 {
420 	p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
421 	wake_up(req->wq);
422 	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
423 }
424 EXPORT_SYMBOL(p9_client_cb);
425 
426 /**
427  * p9_parse_header - parse header arguments out of a packet
428  * @pdu: packet to parse
429  * @size: size of packet
430  * @type: type of request
431  * @tag: tag of packet
432  * @rewind: set if we need to rewind offset afterwards
433  */
434 
435 int
436 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
437 								int rewind)
438 {
439 	int8_t r_type;
440 	int16_t r_tag;
441 	int32_t r_size;
442 	int offset = pdu->offset;
443 	int err;
444 
445 	pdu->offset = 0;
446 	if (pdu->size == 0)
447 		pdu->size = 7;
448 
449 	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
450 	if (err)
451 		goto rewind_and_exit;
452 
453 	pdu->size = r_size;
454 	pdu->id = r_type;
455 	pdu->tag = r_tag;
456 
457 	p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
458 		 pdu->size, pdu->id, pdu->tag);
459 
460 	if (type)
461 		*type = r_type;
462 	if (tag)
463 		*tag = r_tag;
464 	if (size)
465 		*size = r_size;
466 
467 
468 rewind_and_exit:
469 	if (rewind)
470 		pdu->offset = offset;
471 	return err;
472 }
473 EXPORT_SYMBOL(p9_parse_header);
474 
475 /**
476  * p9_check_errors - check 9p packet for error return and process it
477  * @c: current client instance
478  * @req: request to parse and check for error conditions
479  *
480  * returns error code if one is discovered, otherwise returns 0
481  *
482  * this will have to be more complicated if we have multiple
483  * error packet types
484  */
485 
486 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
487 {
488 	int8_t type;
489 	int err;
490 	int ecode;
491 
492 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
493 	/*
494 	 * dump the response from server
495 	 * This should be after check errors which poplulate pdu_fcall.
496 	 */
497 	trace_9p_protocol_dump(c, req->rc);
498 	if (err) {
499 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
500 		return err;
501 	}
502 	if (type != P9_RERROR && type != P9_RLERROR)
503 		return 0;
504 
505 	if (!p9_is_proto_dotl(c)) {
506 		char *ename;
507 		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
508 				  &ename, &ecode);
509 		if (err)
510 			goto out_err;
511 
512 		if (p9_is_proto_dotu(c))
513 			err = -ecode;
514 
515 		if (!err || !IS_ERR_VALUE(err)) {
516 			err = p9_errstr2errno(ename, strlen(ename));
517 
518 			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
519 				 -ecode, ename);
520 		}
521 		kfree(ename);
522 	} else {
523 		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
524 		err = -ecode;
525 
526 		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
527 	}
528 
529 	return err;
530 
531 out_err:
532 	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
533 
534 	return err;
535 }
536 
537 /**
538  * p9_check_zc_errors - check 9p packet for error return and process it
539  * @c: current client instance
540  * @req: request to parse and check for error conditions
541  * @in_hdrlen: Size of response protocol buffer.
542  *
543  * returns error code if one is discovered, otherwise returns 0
544  *
545  * this will have to be more complicated if we have multiple
546  * error packet types
547  */
548 
549 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
550 			      char *uidata, int in_hdrlen, int kern_buf)
551 {
552 	int err;
553 	int ecode;
554 	int8_t type;
555 	char *ename = NULL;
556 
557 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
558 	/*
559 	 * dump the response from server
560 	 * This should be after parse_header which poplulate pdu_fcall.
561 	 */
562 	trace_9p_protocol_dump(c, req->rc);
563 	if (err) {
564 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
565 		return err;
566 	}
567 
568 	if (type != P9_RERROR && type != P9_RLERROR)
569 		return 0;
570 
571 	if (!p9_is_proto_dotl(c)) {
572 		/* Error is reported in string format */
573 		int len;
574 		/* 7 = header size for RERROR; */
575 		int inline_len = in_hdrlen - 7;
576 
577 		len =  req->rc->size - req->rc->offset;
578 		if (len > (P9_ZC_HDR_SZ - 7)) {
579 			err = -EFAULT;
580 			goto out_err;
581 		}
582 
583 		ename = &req->rc->sdata[req->rc->offset];
584 		if (len > inline_len) {
585 			/* We have error in external buffer */
586 			if (kern_buf) {
587 				memcpy(ename + inline_len, uidata,
588 				       len - inline_len);
589 			} else {
590 				err = copy_from_user(ename + inline_len,
591 						     uidata, len - inline_len);
592 				if (err) {
593 					err = -EFAULT;
594 					goto out_err;
595 				}
596 			}
597 		}
598 		ename = NULL;
599 		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
600 				  &ename, &ecode);
601 		if (err)
602 			goto out_err;
603 
604 		if (p9_is_proto_dotu(c))
605 			err = -ecode;
606 
607 		if (!err || !IS_ERR_VALUE(err)) {
608 			err = p9_errstr2errno(ename, strlen(ename));
609 
610 			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
611 				 -ecode, ename);
612 		}
613 		kfree(ename);
614 	} else {
615 		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
616 		err = -ecode;
617 
618 		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
619 	}
620 	return err;
621 
622 out_err:
623 	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
624 	return err;
625 }
626 
627 static struct p9_req_t *
628 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
629 
630 /**
631  * p9_client_flush - flush (cancel) a request
632  * @c: client state
633  * @oldreq: request to cancel
634  *
635  * This sents a flush for a particular request and links
636  * the flush request to the original request.  The current
637  * code only supports a single flush request although the protocol
638  * allows for multiple flush requests to be sent for a single request.
639  *
640  */
641 
642 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
643 {
644 	struct p9_req_t *req;
645 	int16_t oldtag;
646 	int err;
647 
648 	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
649 	if (err)
650 		return err;
651 
652 	p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
653 
654 	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
655 	if (IS_ERR(req))
656 		return PTR_ERR(req);
657 
658 
659 	/*
660 	 * if we haven't received a response for oldreq,
661 	 * remove it from the list
662 	 */
663 	if (oldreq->status == REQ_STATUS_FLSH) {
664 		spin_lock(&c->lock);
665 		list_del(&oldreq->req_list);
666 		spin_unlock(&c->lock);
667 	}
668 
669 	p9_free_req(c, req);
670 	return 0;
671 }
672 
673 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
674 					      int8_t type, int req_size,
675 					      const char *fmt, va_list ap)
676 {
677 	int tag, err;
678 	struct p9_req_t *req;
679 
680 	p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
681 
682 	/* we allow for any status other than disconnected */
683 	if (c->status == Disconnected)
684 		return ERR_PTR(-EIO);
685 
686 	/* if status is begin_disconnected we allow only clunk request */
687 	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
688 		return ERR_PTR(-EIO);
689 
690 	tag = P9_NOTAG;
691 	if (type != P9_TVERSION) {
692 		tag = p9_idpool_get(c->tagpool);
693 		if (tag < 0)
694 			return ERR_PTR(-ENOMEM);
695 	}
696 
697 	req = p9_tag_alloc(c, tag, req_size);
698 	if (IS_ERR(req))
699 		return req;
700 
701 	/* marshall the data */
702 	p9pdu_prepare(req->tc, tag, type);
703 	err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
704 	if (err)
705 		goto reterr;
706 	p9pdu_finalize(c, req->tc);
707 	trace_9p_client_req(c, type, tag);
708 	return req;
709 reterr:
710 	p9_free_req(c, req);
711 	return ERR_PTR(err);
712 }
713 
714 /**
715  * p9_client_rpc - issue a request and wait for a response
716  * @c: client session
717  * @type: type of request
718  * @fmt: protocol format string (see protocol.c)
719  *
720  * Returns request structure (which client must free using p9_free_req)
721  */
722 
723 static struct p9_req_t *
724 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
725 {
726 	va_list ap;
727 	int sigpending, err;
728 	unsigned long flags;
729 	struct p9_req_t *req;
730 
731 	va_start(ap, fmt);
732 	req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
733 	va_end(ap);
734 	if (IS_ERR(req))
735 		return req;
736 
737 	if (signal_pending(current)) {
738 		sigpending = 1;
739 		clear_thread_flag(TIF_SIGPENDING);
740 	} else
741 		sigpending = 0;
742 
743 	err = c->trans_mod->request(c, req);
744 	if (err < 0) {
745 		if (err != -ERESTARTSYS && err != -EFAULT)
746 			c->status = Disconnected;
747 		goto reterr;
748 	}
749 again:
750 	/* Wait for the response */
751 	err = wait_event_interruptible(*req->wq,
752 				       req->status >= REQ_STATUS_RCVD);
753 
754 	if ((err == -ERESTARTSYS) && (c->status == Connected)
755 				  && (type == P9_TFLUSH)) {
756 		sigpending = 1;
757 		clear_thread_flag(TIF_SIGPENDING);
758 		goto again;
759 	}
760 
761 	if (req->status == REQ_STATUS_ERROR) {
762 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
763 		err = req->t_err;
764 	}
765 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
766 		p9_debug(P9_DEBUG_MUX, "flushing\n");
767 		sigpending = 1;
768 		clear_thread_flag(TIF_SIGPENDING);
769 
770 		if (c->trans_mod->cancel(c, req))
771 			p9_client_flush(c, req);
772 
773 		/* if we received the response anyway, don't signal error */
774 		if (req->status == REQ_STATUS_RCVD)
775 			err = 0;
776 	}
777 	if (sigpending) {
778 		spin_lock_irqsave(&current->sighand->siglock, flags);
779 		recalc_sigpending();
780 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
781 	}
782 	if (err < 0)
783 		goto reterr;
784 
785 	err = p9_check_errors(c, req);
786 	trace_9p_client_res(c, type, req->rc->tag, err);
787 	if (!err)
788 		return req;
789 reterr:
790 	p9_free_req(c, req);
791 	return ERR_PTR(safe_errno(err));
792 }
793 
794 /**
795  * p9_client_zc_rpc - issue a request and wait for a response
796  * @c: client session
797  * @type: type of request
798  * @uidata: user bffer that should be ued for zero copy read
799  * @uodata: user buffer that shoud be user for zero copy write
800  * @inlen: read buffer size
801  * @olen: write buffer size
802  * @hdrlen: reader header size, This is the size of response protocol data
803  * @fmt: protocol format string (see protocol.c)
804  *
805  * Returns request structure (which client must free using p9_free_req)
806  */
807 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
808 					 char *uidata, char *uodata,
809 					 int inlen, int olen, int in_hdrlen,
810 					 int kern_buf, const char *fmt, ...)
811 {
812 	va_list ap;
813 	int sigpending, err;
814 	unsigned long flags;
815 	struct p9_req_t *req;
816 
817 	va_start(ap, fmt);
818 	/*
819 	 * We allocate a inline protocol data of only 4k bytes.
820 	 * The actual content is passed in zero-copy fashion.
821 	 */
822 	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
823 	va_end(ap);
824 	if (IS_ERR(req))
825 		return req;
826 
827 	if (signal_pending(current)) {
828 		sigpending = 1;
829 		clear_thread_flag(TIF_SIGPENDING);
830 	} else
831 		sigpending = 0;
832 
833 	/* If we are called with KERNEL_DS force kern_buf */
834 	if (segment_eq(get_fs(), KERNEL_DS))
835 		kern_buf = 1;
836 
837 	err = c->trans_mod->zc_request(c, req, uidata, uodata,
838 				       inlen, olen, in_hdrlen, kern_buf);
839 	if (err < 0) {
840 		if (err == -EIO)
841 			c->status = Disconnected;
842 		goto reterr;
843 	}
844 	if (req->status == REQ_STATUS_ERROR) {
845 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
846 		err = req->t_err;
847 	}
848 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
849 		p9_debug(P9_DEBUG_MUX, "flushing\n");
850 		sigpending = 1;
851 		clear_thread_flag(TIF_SIGPENDING);
852 
853 		if (c->trans_mod->cancel(c, req))
854 			p9_client_flush(c, req);
855 
856 		/* if we received the response anyway, don't signal error */
857 		if (req->status == REQ_STATUS_RCVD)
858 			err = 0;
859 	}
860 	if (sigpending) {
861 		spin_lock_irqsave(&current->sighand->siglock, flags);
862 		recalc_sigpending();
863 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
864 	}
865 	if (err < 0)
866 		goto reterr;
867 
868 	err = p9_check_zc_errors(c, req, uidata, in_hdrlen, kern_buf);
869 	trace_9p_client_res(c, type, req->rc->tag, err);
870 	if (!err)
871 		return req;
872 reterr:
873 	p9_free_req(c, req);
874 	return ERR_PTR(safe_errno(err));
875 }
876 
877 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
878 {
879 	int ret;
880 	struct p9_fid *fid;
881 	unsigned long flags;
882 
883 	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
884 	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
885 	if (!fid)
886 		return ERR_PTR(-ENOMEM);
887 
888 	ret = p9_idpool_get(clnt->fidpool);
889 	if (ret < 0) {
890 		ret = -ENOSPC;
891 		goto error;
892 	}
893 	fid->fid = ret;
894 
895 	memset(&fid->qid, 0, sizeof(struct p9_qid));
896 	fid->mode = -1;
897 	fid->uid = current_fsuid();
898 	fid->clnt = clnt;
899 	fid->rdir = NULL;
900 	spin_lock_irqsave(&clnt->lock, flags);
901 	list_add(&fid->flist, &clnt->fidlist);
902 	spin_unlock_irqrestore(&clnt->lock, flags);
903 
904 	return fid;
905 
906 error:
907 	kfree(fid);
908 	return ERR_PTR(ret);
909 }
910 
911 static void p9_fid_destroy(struct p9_fid *fid)
912 {
913 	struct p9_client *clnt;
914 	unsigned long flags;
915 
916 	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
917 	clnt = fid->clnt;
918 	p9_idpool_put(fid->fid, clnt->fidpool);
919 	spin_lock_irqsave(&clnt->lock, flags);
920 	list_del(&fid->flist);
921 	spin_unlock_irqrestore(&clnt->lock, flags);
922 	kfree(fid->rdir);
923 	kfree(fid);
924 }
925 
926 static int p9_client_version(struct p9_client *c)
927 {
928 	int err = 0;
929 	struct p9_req_t *req;
930 	char *version;
931 	int msize;
932 
933 	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
934 		 c->msize, c->proto_version);
935 
936 	switch (c->proto_version) {
937 	case p9_proto_2000L:
938 		req = p9_client_rpc(c, P9_TVERSION, "ds",
939 					c->msize, "9P2000.L");
940 		break;
941 	case p9_proto_2000u:
942 		req = p9_client_rpc(c, P9_TVERSION, "ds",
943 					c->msize, "9P2000.u");
944 		break;
945 	case p9_proto_legacy:
946 		req = p9_client_rpc(c, P9_TVERSION, "ds",
947 					c->msize, "9P2000");
948 		break;
949 	default:
950 		return -EINVAL;
951 		break;
952 	}
953 
954 	if (IS_ERR(req))
955 		return PTR_ERR(req);
956 
957 	err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
958 	if (err) {
959 		p9_debug(P9_DEBUG_9P, "version error %d\n", err);
960 		trace_9p_protocol_dump(c, req->rc);
961 		goto error;
962 	}
963 
964 	p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
965 	if (!strncmp(version, "9P2000.L", 8))
966 		c->proto_version = p9_proto_2000L;
967 	else if (!strncmp(version, "9P2000.u", 8))
968 		c->proto_version = p9_proto_2000u;
969 	else if (!strncmp(version, "9P2000", 6))
970 		c->proto_version = p9_proto_legacy;
971 	else {
972 		err = -EREMOTEIO;
973 		goto error;
974 	}
975 
976 	if (msize < c->msize)
977 		c->msize = msize;
978 
979 error:
980 	kfree(version);
981 	p9_free_req(c, req);
982 
983 	return err;
984 }
985 
986 struct p9_client *p9_client_create(const char *dev_name, char *options)
987 {
988 	int err;
989 	struct p9_client *clnt;
990 
991 	err = 0;
992 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
993 	if (!clnt)
994 		return ERR_PTR(-ENOMEM);
995 
996 	clnt->trans_mod = NULL;
997 	clnt->trans = NULL;
998 	spin_lock_init(&clnt->lock);
999 	INIT_LIST_HEAD(&clnt->fidlist);
1000 
1001 	err = p9_tag_init(clnt);
1002 	if (err < 0)
1003 		goto free_client;
1004 
1005 	err = parse_opts(options, clnt);
1006 	if (err < 0)
1007 		goto destroy_tagpool;
1008 
1009 	if (!clnt->trans_mod)
1010 		clnt->trans_mod = v9fs_get_trans_by_name("virtio");
1011 
1012 	if (!clnt->trans_mod)
1013 		clnt->trans_mod = v9fs_get_default_trans();
1014 
1015 	if (clnt->trans_mod == NULL) {
1016 		err = -EPROTONOSUPPORT;
1017 		p9_debug(P9_DEBUG_ERROR,
1018 			 "No transport defined or default transport\n");
1019 		goto destroy_tagpool;
1020 	}
1021 
1022 	clnt->fidpool = p9_idpool_create();
1023 	if (IS_ERR(clnt->fidpool)) {
1024 		err = PTR_ERR(clnt->fidpool);
1025 		goto put_trans;
1026 	}
1027 
1028 	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1029 		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1030 
1031 	err = clnt->trans_mod->create(clnt, dev_name, options);
1032 	if (err)
1033 		goto destroy_fidpool;
1034 
1035 	if (clnt->msize > clnt->trans_mod->maxsize)
1036 		clnt->msize = clnt->trans_mod->maxsize;
1037 
1038 	err = p9_client_version(clnt);
1039 	if (err)
1040 		goto close_trans;
1041 
1042 	return clnt;
1043 
1044 close_trans:
1045 	clnt->trans_mod->close(clnt);
1046 destroy_fidpool:
1047 	p9_idpool_destroy(clnt->fidpool);
1048 put_trans:
1049 	v9fs_put_trans(clnt->trans_mod);
1050 destroy_tagpool:
1051 	p9_idpool_destroy(clnt->tagpool);
1052 free_client:
1053 	kfree(clnt);
1054 	return ERR_PTR(err);
1055 }
1056 EXPORT_SYMBOL(p9_client_create);
1057 
1058 void p9_client_destroy(struct p9_client *clnt)
1059 {
1060 	struct p9_fid *fid, *fidptr;
1061 
1062 	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1063 
1064 	if (clnt->trans_mod)
1065 		clnt->trans_mod->close(clnt);
1066 
1067 	v9fs_put_trans(clnt->trans_mod);
1068 
1069 	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1070 		pr_info("Found fid %d not clunked\n", fid->fid);
1071 		p9_fid_destroy(fid);
1072 	}
1073 
1074 	if (clnt->fidpool)
1075 		p9_idpool_destroy(clnt->fidpool);
1076 
1077 	p9_tag_cleanup(clnt);
1078 
1079 	kfree(clnt);
1080 }
1081 EXPORT_SYMBOL(p9_client_destroy);
1082 
1083 void p9_client_disconnect(struct p9_client *clnt)
1084 {
1085 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1086 	clnt->status = Disconnected;
1087 }
1088 EXPORT_SYMBOL(p9_client_disconnect);
1089 
1090 void p9_client_begin_disconnect(struct p9_client *clnt)
1091 {
1092 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1093 	clnt->status = BeginDisconnect;
1094 }
1095 EXPORT_SYMBOL(p9_client_begin_disconnect);
1096 
1097 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1098 	char *uname, kuid_t n_uname, char *aname)
1099 {
1100 	int err = 0;
1101 	struct p9_req_t *req;
1102 	struct p9_fid *fid;
1103 	struct p9_qid qid;
1104 
1105 
1106 	p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1107 		 afid ? afid->fid : -1, uname, aname);
1108 	fid = p9_fid_create(clnt);
1109 	if (IS_ERR(fid)) {
1110 		err = PTR_ERR(fid);
1111 		fid = NULL;
1112 		goto error;
1113 	}
1114 
1115 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1116 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1117 	if (IS_ERR(req)) {
1118 		err = PTR_ERR(req);
1119 		goto error;
1120 	}
1121 
1122 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1123 	if (err) {
1124 		trace_9p_protocol_dump(clnt, req->rc);
1125 		p9_free_req(clnt, req);
1126 		goto error;
1127 	}
1128 
1129 	p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1130 		 qid.type, (unsigned long long)qid.path, qid.version);
1131 
1132 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1133 
1134 	p9_free_req(clnt, req);
1135 	return fid;
1136 
1137 error:
1138 	if (fid)
1139 		p9_fid_destroy(fid);
1140 	return ERR_PTR(err);
1141 }
1142 EXPORT_SYMBOL(p9_client_attach);
1143 
1144 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1145 		char **wnames, int clone)
1146 {
1147 	int err;
1148 	struct p9_client *clnt;
1149 	struct p9_fid *fid;
1150 	struct p9_qid *wqids;
1151 	struct p9_req_t *req;
1152 	uint16_t nwqids, count;
1153 
1154 	err = 0;
1155 	wqids = NULL;
1156 	clnt = oldfid->clnt;
1157 	if (clone) {
1158 		fid = p9_fid_create(clnt);
1159 		if (IS_ERR(fid)) {
1160 			err = PTR_ERR(fid);
1161 			fid = NULL;
1162 			goto error;
1163 		}
1164 
1165 		fid->uid = oldfid->uid;
1166 	} else
1167 		fid = oldfid;
1168 
1169 
1170 	p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1171 		 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1172 
1173 	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1174 								nwname, wnames);
1175 	if (IS_ERR(req)) {
1176 		err = PTR_ERR(req);
1177 		goto error;
1178 	}
1179 
1180 	err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1181 	if (err) {
1182 		trace_9p_protocol_dump(clnt, req->rc);
1183 		p9_free_req(clnt, req);
1184 		goto clunk_fid;
1185 	}
1186 	p9_free_req(clnt, req);
1187 
1188 	p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1189 
1190 	if (nwqids != nwname) {
1191 		err = -ENOENT;
1192 		goto clunk_fid;
1193 	}
1194 
1195 	for (count = 0; count < nwqids; count++)
1196 		p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1197 			count, wqids[count].type,
1198 			(unsigned long long)wqids[count].path,
1199 			wqids[count].version);
1200 
1201 	if (nwname)
1202 		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1203 	else
1204 		fid->qid = oldfid->qid;
1205 
1206 	kfree(wqids);
1207 	return fid;
1208 
1209 clunk_fid:
1210 	kfree(wqids);
1211 	p9_client_clunk(fid);
1212 	fid = NULL;
1213 
1214 error:
1215 	if (fid && (fid != oldfid))
1216 		p9_fid_destroy(fid);
1217 
1218 	return ERR_PTR(err);
1219 }
1220 EXPORT_SYMBOL(p9_client_walk);
1221 
1222 int p9_client_open(struct p9_fid *fid, int mode)
1223 {
1224 	int err;
1225 	struct p9_client *clnt;
1226 	struct p9_req_t *req;
1227 	struct p9_qid qid;
1228 	int iounit;
1229 
1230 	clnt = fid->clnt;
1231 	p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1232 		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1233 	err = 0;
1234 
1235 	if (fid->mode != -1)
1236 		return -EINVAL;
1237 
1238 	if (p9_is_proto_dotl(clnt))
1239 		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1240 	else
1241 		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1242 	if (IS_ERR(req)) {
1243 		err = PTR_ERR(req);
1244 		goto error;
1245 	}
1246 
1247 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1248 	if (err) {
1249 		trace_9p_protocol_dump(clnt, req->rc);
1250 		goto free_and_error;
1251 	}
1252 
1253 	p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1254 		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1255 		(unsigned long long)qid.path, qid.version, iounit);
1256 
1257 	fid->mode = mode;
1258 	fid->iounit = iounit;
1259 
1260 free_and_error:
1261 	p9_free_req(clnt, req);
1262 error:
1263 	return err;
1264 }
1265 EXPORT_SYMBOL(p9_client_open);
1266 
1267 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1268 		kgid_t gid, struct p9_qid *qid)
1269 {
1270 	int err = 0;
1271 	struct p9_client *clnt;
1272 	struct p9_req_t *req;
1273 	int iounit;
1274 
1275 	p9_debug(P9_DEBUG_9P,
1276 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1277 			ofid->fid, name, flags, mode,
1278 		 	from_kgid(&init_user_ns, gid));
1279 	clnt = ofid->clnt;
1280 
1281 	if (ofid->mode != -1)
1282 		return -EINVAL;
1283 
1284 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1285 			mode, gid);
1286 	if (IS_ERR(req)) {
1287 		err = PTR_ERR(req);
1288 		goto error;
1289 	}
1290 
1291 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1292 	if (err) {
1293 		trace_9p_protocol_dump(clnt, req->rc);
1294 		goto free_and_error;
1295 	}
1296 
1297 	p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1298 			qid->type,
1299 			(unsigned long long)qid->path,
1300 			qid->version, iounit);
1301 
1302 	ofid->mode = mode;
1303 	ofid->iounit = iounit;
1304 
1305 free_and_error:
1306 	p9_free_req(clnt, req);
1307 error:
1308 	return err;
1309 }
1310 EXPORT_SYMBOL(p9_client_create_dotl);
1311 
1312 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1313 		     char *extension)
1314 {
1315 	int err;
1316 	struct p9_client *clnt;
1317 	struct p9_req_t *req;
1318 	struct p9_qid qid;
1319 	int iounit;
1320 
1321 	p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1322 						fid->fid, name, perm, mode);
1323 	err = 0;
1324 	clnt = fid->clnt;
1325 
1326 	if (fid->mode != -1)
1327 		return -EINVAL;
1328 
1329 	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1330 				mode, extension);
1331 	if (IS_ERR(req)) {
1332 		err = PTR_ERR(req);
1333 		goto error;
1334 	}
1335 
1336 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1337 	if (err) {
1338 		trace_9p_protocol_dump(clnt, req->rc);
1339 		goto free_and_error;
1340 	}
1341 
1342 	p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1343 				qid.type,
1344 				(unsigned long long)qid.path,
1345 				qid.version, iounit);
1346 
1347 	fid->mode = mode;
1348 	fid->iounit = iounit;
1349 
1350 free_and_error:
1351 	p9_free_req(clnt, req);
1352 error:
1353 	return err;
1354 }
1355 EXPORT_SYMBOL(p9_client_fcreate);
1356 
1357 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
1358 		struct p9_qid *qid)
1359 {
1360 	int err = 0;
1361 	struct p9_client *clnt;
1362 	struct p9_req_t *req;
1363 
1364 	p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1365 			dfid->fid, name, symtgt);
1366 	clnt = dfid->clnt;
1367 
1368 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1369 			gid);
1370 	if (IS_ERR(req)) {
1371 		err = PTR_ERR(req);
1372 		goto error;
1373 	}
1374 
1375 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1376 	if (err) {
1377 		trace_9p_protocol_dump(clnt, req->rc);
1378 		goto free_and_error;
1379 	}
1380 
1381 	p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1382 			qid->type, (unsigned long long)qid->path, qid->version);
1383 
1384 free_and_error:
1385 	p9_free_req(clnt, req);
1386 error:
1387 	return err;
1388 }
1389 EXPORT_SYMBOL(p9_client_symlink);
1390 
1391 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1392 {
1393 	struct p9_client *clnt;
1394 	struct p9_req_t *req;
1395 
1396 	p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1397 			dfid->fid, oldfid->fid, newname);
1398 	clnt = dfid->clnt;
1399 	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1400 			newname);
1401 	if (IS_ERR(req))
1402 		return PTR_ERR(req);
1403 
1404 	p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1405 	p9_free_req(clnt, req);
1406 	return 0;
1407 }
1408 EXPORT_SYMBOL(p9_client_link);
1409 
1410 int p9_client_fsync(struct p9_fid *fid, int datasync)
1411 {
1412 	int err;
1413 	struct p9_client *clnt;
1414 	struct p9_req_t *req;
1415 
1416 	p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1417 			fid->fid, datasync);
1418 	err = 0;
1419 	clnt = fid->clnt;
1420 
1421 	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1422 	if (IS_ERR(req)) {
1423 		err = PTR_ERR(req);
1424 		goto error;
1425 	}
1426 
1427 	p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1428 
1429 	p9_free_req(clnt, req);
1430 
1431 error:
1432 	return err;
1433 }
1434 EXPORT_SYMBOL(p9_client_fsync);
1435 
1436 int p9_client_clunk(struct p9_fid *fid)
1437 {
1438 	int err;
1439 	struct p9_client *clnt;
1440 	struct p9_req_t *req;
1441 	int retries = 0;
1442 
1443 	if (!fid) {
1444 		pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1445 			__func__, task_pid_nr(current));
1446 		dump_stack();
1447 		return 0;
1448 	}
1449 
1450 again:
1451 	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1452 								retries);
1453 	err = 0;
1454 	clnt = fid->clnt;
1455 
1456 	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1457 	if (IS_ERR(req)) {
1458 		err = PTR_ERR(req);
1459 		goto error;
1460 	}
1461 
1462 	p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1463 
1464 	p9_free_req(clnt, req);
1465 error:
1466 	/*
1467 	 * Fid is not valid even after a failed clunk
1468 	 * If interrupted, retry once then give up and
1469 	 * leak fid until umount.
1470 	 */
1471 	if (err == -ERESTARTSYS) {
1472 		if (retries++ == 0)
1473 			goto again;
1474 	} else
1475 		p9_fid_destroy(fid);
1476 	return err;
1477 }
1478 EXPORT_SYMBOL(p9_client_clunk);
1479 
1480 int p9_client_remove(struct p9_fid *fid)
1481 {
1482 	int err;
1483 	struct p9_client *clnt;
1484 	struct p9_req_t *req;
1485 
1486 	p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1487 	err = 0;
1488 	clnt = fid->clnt;
1489 
1490 	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1491 	if (IS_ERR(req)) {
1492 		err = PTR_ERR(req);
1493 		goto error;
1494 	}
1495 
1496 	p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1497 
1498 	p9_free_req(clnt, req);
1499 error:
1500 	if (err == -ERESTARTSYS)
1501 		p9_client_clunk(fid);
1502 	else
1503 		p9_fid_destroy(fid);
1504 	return err;
1505 }
1506 EXPORT_SYMBOL(p9_client_remove);
1507 
1508 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1509 {
1510 	int err = 0;
1511 	struct p9_req_t *req;
1512 	struct p9_client *clnt;
1513 
1514 	p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1515 		   dfid->fid, name, flags);
1516 
1517 	clnt = dfid->clnt;
1518 	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1519 	if (IS_ERR(req)) {
1520 		err = PTR_ERR(req);
1521 		goto error;
1522 	}
1523 	p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1524 
1525 	p9_free_req(clnt, req);
1526 error:
1527 	return err;
1528 }
1529 EXPORT_SYMBOL(p9_client_unlinkat);
1530 
1531 int
1532 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1533 								u32 count)
1534 {
1535 	char *dataptr;
1536 	int kernel_buf = 0;
1537 	struct p9_req_t *req;
1538 	struct p9_client *clnt;
1539 	int err, rsize, non_zc = 0;
1540 
1541 
1542 	p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1543 		   fid->fid, (unsigned long long) offset, count);
1544 	err = 0;
1545 	clnt = fid->clnt;
1546 
1547 	rsize = fid->iounit;
1548 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1549 		rsize = clnt->msize - P9_IOHDRSZ;
1550 
1551 	if (count < rsize)
1552 		rsize = count;
1553 
1554 	/* Don't bother zerocopy for small IO (< 1024) */
1555 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1556 		char *indata;
1557 		if (data) {
1558 			kernel_buf = 1;
1559 			indata = data;
1560 		} else
1561 			indata = (__force char *)udata;
1562 		/*
1563 		 * response header len is 11
1564 		 * PDU Header(7) + IO Size (4)
1565 		 */
1566 		req = p9_client_zc_rpc(clnt, P9_TREAD, indata, NULL, rsize, 0,
1567 				       11, kernel_buf, "dqd", fid->fid,
1568 				       offset, rsize);
1569 	} else {
1570 		non_zc = 1;
1571 		req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1572 				    rsize);
1573 	}
1574 	if (IS_ERR(req)) {
1575 		err = PTR_ERR(req);
1576 		goto error;
1577 	}
1578 
1579 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1580 	if (err) {
1581 		trace_9p_protocol_dump(clnt, req->rc);
1582 		goto free_and_error;
1583 	}
1584 
1585 	p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1586 
1587 	if (non_zc) {
1588 		if (data) {
1589 			memmove(data, dataptr, count);
1590 		} else {
1591 			err = copy_to_user(udata, dataptr, count);
1592 			if (err) {
1593 				err = -EFAULT;
1594 				goto free_and_error;
1595 			}
1596 		}
1597 	}
1598 	p9_free_req(clnt, req);
1599 	return count;
1600 
1601 free_and_error:
1602 	p9_free_req(clnt, req);
1603 error:
1604 	return err;
1605 }
1606 EXPORT_SYMBOL(p9_client_read);
1607 
1608 int
1609 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1610 							u64 offset, u32 count)
1611 {
1612 	int err, rsize;
1613 	int kernel_buf = 0;
1614 	struct p9_client *clnt;
1615 	struct p9_req_t *req;
1616 
1617 	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1618 				fid->fid, (unsigned long long) offset, count);
1619 	err = 0;
1620 	clnt = fid->clnt;
1621 
1622 	rsize = fid->iounit;
1623 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1624 		rsize = clnt->msize - P9_IOHDRSZ;
1625 
1626 	if (count < rsize)
1627 		rsize = count;
1628 
1629 	/* Don't bother zerocopy for small IO (< 1024) */
1630 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1631 		char *odata;
1632 		if (data) {
1633 			kernel_buf = 1;
1634 			odata = data;
1635 		} else
1636 			odata = (char *)udata;
1637 		req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, odata, 0, rsize,
1638 				       P9_ZC_HDR_SZ, kernel_buf, "dqd",
1639 				       fid->fid, offset, rsize);
1640 	} else {
1641 		if (data)
1642 			req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1643 					    offset, rsize, data);
1644 		else
1645 			req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1646 					    offset, rsize, udata);
1647 	}
1648 	if (IS_ERR(req)) {
1649 		err = PTR_ERR(req);
1650 		goto error;
1651 	}
1652 
1653 	err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1654 	if (err) {
1655 		trace_9p_protocol_dump(clnt, req->rc);
1656 		goto free_and_error;
1657 	}
1658 
1659 	p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1660 
1661 	p9_free_req(clnt, req);
1662 	return count;
1663 
1664 free_and_error:
1665 	p9_free_req(clnt, req);
1666 error:
1667 	return err;
1668 }
1669 EXPORT_SYMBOL(p9_client_write);
1670 
1671 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1672 {
1673 	int err;
1674 	struct p9_client *clnt;
1675 	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1676 	struct p9_req_t *req;
1677 	u16 ignored;
1678 
1679 	p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1680 
1681 	if (!ret)
1682 		return ERR_PTR(-ENOMEM);
1683 
1684 	err = 0;
1685 	clnt = fid->clnt;
1686 
1687 	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1688 	if (IS_ERR(req)) {
1689 		err = PTR_ERR(req);
1690 		goto error;
1691 	}
1692 
1693 	err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1694 	if (err) {
1695 		trace_9p_protocol_dump(clnt, req->rc);
1696 		p9_free_req(clnt, req);
1697 		goto error;
1698 	}
1699 
1700 	p9_debug(P9_DEBUG_9P,
1701 		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1702 		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1703 		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1704 		"<<<    uid=%d gid=%d n_muid=%d\n",
1705 		ret->size, ret->type, ret->dev, ret->qid.type,
1706 		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1707 		ret->atime, ret->mtime, (unsigned long long)ret->length,
1708 		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1709 		from_kuid(&init_user_ns, ret->n_uid),
1710 		from_kgid(&init_user_ns, ret->n_gid),
1711 		from_kuid(&init_user_ns, ret->n_muid));
1712 
1713 	p9_free_req(clnt, req);
1714 	return ret;
1715 
1716 error:
1717 	kfree(ret);
1718 	return ERR_PTR(err);
1719 }
1720 EXPORT_SYMBOL(p9_client_stat);
1721 
1722 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1723 							u64 request_mask)
1724 {
1725 	int err;
1726 	struct p9_client *clnt;
1727 	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1728 								GFP_KERNEL);
1729 	struct p9_req_t *req;
1730 
1731 	p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1732 							fid->fid, request_mask);
1733 
1734 	if (!ret)
1735 		return ERR_PTR(-ENOMEM);
1736 
1737 	err = 0;
1738 	clnt = fid->clnt;
1739 
1740 	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1741 	if (IS_ERR(req)) {
1742 		err = PTR_ERR(req);
1743 		goto error;
1744 	}
1745 
1746 	err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1747 	if (err) {
1748 		trace_9p_protocol_dump(clnt, req->rc);
1749 		p9_free_req(clnt, req);
1750 		goto error;
1751 	}
1752 
1753 	p9_debug(P9_DEBUG_9P,
1754 		"<<< RGETATTR st_result_mask=%lld\n"
1755 		"<<< qid=%x.%llx.%x\n"
1756 		"<<< st_mode=%8.8x st_nlink=%llu\n"
1757 		"<<< st_uid=%d st_gid=%d\n"
1758 		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1759 		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1760 		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1761 		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1762 		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1763 		"<<< st_gen=%lld st_data_version=%lld",
1764 		ret->st_result_mask, ret->qid.type, ret->qid.path,
1765 		ret->qid.version, ret->st_mode, ret->st_nlink,
1766 		from_kuid(&init_user_ns, ret->st_uid),
1767 		from_kgid(&init_user_ns, ret->st_gid),
1768 		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 		from_kuid(&init_user_ns, wst->n_uid),
1832 		from_kgid(&init_user_ns, wst->n_gid),
1833 		from_kuid(&init_user_ns, wst->n_muid));
1834 
1835 	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1836 	if (IS_ERR(req)) {
1837 		err = PTR_ERR(req);
1838 		goto error;
1839 	}
1840 
1841 	p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1842 
1843 	p9_free_req(clnt, req);
1844 error:
1845 	return err;
1846 }
1847 EXPORT_SYMBOL(p9_client_wstat);
1848 
1849 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1850 {
1851 	int err;
1852 	struct p9_req_t *req;
1853 	struct p9_client *clnt;
1854 
1855 	err = 0;
1856 	clnt = fid->clnt;
1857 	p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1858 	p9_debug(P9_DEBUG_9P,
1859 		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1860 		"    atime_sec=%lld atime_nsec=%lld\n"
1861 		"    mtime_sec=%lld mtime_nsec=%lld\n",
1862 		p9attr->valid, p9attr->mode,
1863 		from_kuid(&init_user_ns, p9attr->uid),
1864 		from_kgid(&init_user_ns, p9attr->gid),
1865 		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1866 		p9attr->mtime_sec, p9attr->mtime_nsec);
1867 
1868 	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1869 
1870 	if (IS_ERR(req)) {
1871 		err = PTR_ERR(req);
1872 		goto error;
1873 	}
1874 	p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1875 	p9_free_req(clnt, req);
1876 error:
1877 	return err;
1878 }
1879 EXPORT_SYMBOL(p9_client_setattr);
1880 
1881 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1882 {
1883 	int err;
1884 	struct p9_req_t *req;
1885 	struct p9_client *clnt;
1886 
1887 	err = 0;
1888 	clnt = fid->clnt;
1889 
1890 	p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1891 
1892 	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1893 	if (IS_ERR(req)) {
1894 		err = PTR_ERR(req);
1895 		goto error;
1896 	}
1897 
1898 	err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1899 		&sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1900 		&sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1901 	if (err) {
1902 		trace_9p_protocol_dump(clnt, req->rc);
1903 		p9_free_req(clnt, req);
1904 		goto error;
1905 	}
1906 
1907 	p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1908 		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1909 		"fsid %llu namelen %ld\n",
1910 		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1911 		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1912 		sb->fsid, (long int)sb->namelen);
1913 
1914 	p9_free_req(clnt, req);
1915 error:
1916 	return err;
1917 }
1918 EXPORT_SYMBOL(p9_client_statfs);
1919 
1920 int p9_client_rename(struct p9_fid *fid,
1921 		     struct p9_fid *newdirfid, const char *name)
1922 {
1923 	int err;
1924 	struct p9_req_t *req;
1925 	struct p9_client *clnt;
1926 
1927 	err = 0;
1928 	clnt = fid->clnt;
1929 
1930 	p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1931 			fid->fid, newdirfid->fid, name);
1932 
1933 	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1934 			newdirfid->fid, name);
1935 	if (IS_ERR(req)) {
1936 		err = PTR_ERR(req);
1937 		goto error;
1938 	}
1939 
1940 	p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1941 
1942 	p9_free_req(clnt, req);
1943 error:
1944 	return err;
1945 }
1946 EXPORT_SYMBOL(p9_client_rename);
1947 
1948 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1949 		       struct p9_fid *newdirfid, const char *new_name)
1950 {
1951 	int err;
1952 	struct p9_req_t *req;
1953 	struct p9_client *clnt;
1954 
1955 	err = 0;
1956 	clnt = olddirfid->clnt;
1957 
1958 	p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1959 		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1960 		   newdirfid->fid, new_name);
1961 
1962 	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1963 			    old_name, newdirfid->fid, new_name);
1964 	if (IS_ERR(req)) {
1965 		err = PTR_ERR(req);
1966 		goto error;
1967 	}
1968 
1969 	p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1970 		   newdirfid->fid, new_name);
1971 
1972 	p9_free_req(clnt, req);
1973 error:
1974 	return err;
1975 }
1976 EXPORT_SYMBOL(p9_client_renameat);
1977 
1978 /*
1979  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1980  */
1981 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1982 				const char *attr_name, u64 *attr_size)
1983 {
1984 	int err;
1985 	struct p9_req_t *req;
1986 	struct p9_client *clnt;
1987 	struct p9_fid *attr_fid;
1988 
1989 	err = 0;
1990 	clnt = file_fid->clnt;
1991 	attr_fid = p9_fid_create(clnt);
1992 	if (IS_ERR(attr_fid)) {
1993 		err = PTR_ERR(attr_fid);
1994 		attr_fid = NULL;
1995 		goto error;
1996 	}
1997 	p9_debug(P9_DEBUG_9P,
1998 		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1999 		file_fid->fid, attr_fid->fid, attr_name);
2000 
2001 	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2002 			file_fid->fid, attr_fid->fid, attr_name);
2003 	if (IS_ERR(req)) {
2004 		err = PTR_ERR(req);
2005 		goto error;
2006 	}
2007 	err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2008 	if (err) {
2009 		trace_9p_protocol_dump(clnt, req->rc);
2010 		p9_free_req(clnt, req);
2011 		goto clunk_fid;
2012 	}
2013 	p9_free_req(clnt, req);
2014 	p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2015 		attr_fid->fid, *attr_size);
2016 	return attr_fid;
2017 clunk_fid:
2018 	p9_client_clunk(attr_fid);
2019 	attr_fid = NULL;
2020 error:
2021 	if (attr_fid && (attr_fid != file_fid))
2022 		p9_fid_destroy(attr_fid);
2023 
2024 	return ERR_PTR(err);
2025 }
2026 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2027 
2028 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2029 			u64 attr_size, int flags)
2030 {
2031 	int err;
2032 	struct p9_req_t *req;
2033 	struct p9_client *clnt;
2034 
2035 	p9_debug(P9_DEBUG_9P,
2036 		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2037 		fid->fid, name, (long long)attr_size, flags);
2038 	err = 0;
2039 	clnt = fid->clnt;
2040 	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2041 			fid->fid, name, attr_size, flags);
2042 	if (IS_ERR(req)) {
2043 		err = PTR_ERR(req);
2044 		goto error;
2045 	}
2046 	p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2047 	p9_free_req(clnt, req);
2048 error:
2049 	return err;
2050 }
2051 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2052 
2053 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2054 {
2055 	int err, rsize, non_zc = 0;
2056 	struct p9_client *clnt;
2057 	struct p9_req_t *req;
2058 	char *dataptr;
2059 
2060 	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2061 				fid->fid, (unsigned long long) offset, count);
2062 
2063 	err = 0;
2064 	clnt = fid->clnt;
2065 
2066 	rsize = fid->iounit;
2067 	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2068 		rsize = clnt->msize - P9_READDIRHDRSZ;
2069 
2070 	if (count < rsize)
2071 		rsize = count;
2072 
2073 	/* Don't bother zerocopy for small IO (< 1024) */
2074 	if (clnt->trans_mod->zc_request && rsize > 1024) {
2075 		/*
2076 		 * response header len is 11
2077 		 * PDU Header(7) + IO Size (4)
2078 		 */
2079 		req = p9_client_zc_rpc(clnt, P9_TREADDIR, data, NULL, rsize, 0,
2080 				       11, 1, "dqd", fid->fid, offset, rsize);
2081 	} else {
2082 		non_zc = 1;
2083 		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2084 				    offset, rsize);
2085 	}
2086 	if (IS_ERR(req)) {
2087 		err = PTR_ERR(req);
2088 		goto error;
2089 	}
2090 
2091 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2092 	if (err) {
2093 		trace_9p_protocol_dump(clnt, req->rc);
2094 		goto free_and_error;
2095 	}
2096 
2097 	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2098 
2099 	if (non_zc)
2100 		memmove(data, dataptr, count);
2101 
2102 	p9_free_req(clnt, req);
2103 	return count;
2104 
2105 free_and_error:
2106 	p9_free_req(clnt, req);
2107 error:
2108 	return err;
2109 }
2110 EXPORT_SYMBOL(p9_client_readdir);
2111 
2112 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2113 			dev_t rdev, kgid_t gid, struct p9_qid *qid)
2114 {
2115 	int err;
2116 	struct p9_client *clnt;
2117 	struct p9_req_t *req;
2118 
2119 	err = 0;
2120 	clnt = fid->clnt;
2121 	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2122 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2123 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2124 		MAJOR(rdev), MINOR(rdev), gid);
2125 	if (IS_ERR(req))
2126 		return PTR_ERR(req);
2127 
2128 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2129 	if (err) {
2130 		trace_9p_protocol_dump(clnt, req->rc);
2131 		goto error;
2132 	}
2133 	p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2134 				(unsigned long long)qid->path, qid->version);
2135 
2136 error:
2137 	p9_free_req(clnt, req);
2138 	return err;
2139 
2140 }
2141 EXPORT_SYMBOL(p9_client_mknod_dotl);
2142 
2143 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2144 				kgid_t gid, struct p9_qid *qid)
2145 {
2146 	int err;
2147 	struct p9_client *clnt;
2148 	struct p9_req_t *req;
2149 
2150 	err = 0;
2151 	clnt = fid->clnt;
2152 	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2153 		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2154 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2155 		gid);
2156 	if (IS_ERR(req))
2157 		return PTR_ERR(req);
2158 
2159 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2160 	if (err) {
2161 		trace_9p_protocol_dump(clnt, req->rc);
2162 		goto error;
2163 	}
2164 	p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2165 				(unsigned long long)qid->path, qid->version);
2166 
2167 error:
2168 	p9_free_req(clnt, req);
2169 	return err;
2170 
2171 }
2172 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2173 
2174 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2175 {
2176 	int err;
2177 	struct p9_client *clnt;
2178 	struct p9_req_t *req;
2179 
2180 	err = 0;
2181 	clnt = fid->clnt;
2182 	p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2183 			"start %lld length %lld proc_id %d client_id %s\n",
2184 			fid->fid, flock->type, flock->flags, flock->start,
2185 			flock->length, flock->proc_id, flock->client_id);
2186 
2187 	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2188 				flock->flags, flock->start, flock->length,
2189 					flock->proc_id, flock->client_id);
2190 
2191 	if (IS_ERR(req))
2192 		return PTR_ERR(req);
2193 
2194 	err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2195 	if (err) {
2196 		trace_9p_protocol_dump(clnt, req->rc);
2197 		goto error;
2198 	}
2199 	p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2200 error:
2201 	p9_free_req(clnt, req);
2202 	return err;
2203 
2204 }
2205 EXPORT_SYMBOL(p9_client_lock_dotl);
2206 
2207 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2208 {
2209 	int err;
2210 	struct p9_client *clnt;
2211 	struct p9_req_t *req;
2212 
2213 	err = 0;
2214 	clnt = fid->clnt;
2215 	p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2216 		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2217 		glock->start, glock->length, glock->proc_id, glock->client_id);
2218 
2219 	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2220 		glock->start, glock->length, glock->proc_id, glock->client_id);
2221 
2222 	if (IS_ERR(req))
2223 		return PTR_ERR(req);
2224 
2225 	err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2226 			&glock->start, &glock->length, &glock->proc_id,
2227 			&glock->client_id);
2228 	if (err) {
2229 		trace_9p_protocol_dump(clnt, req->rc);
2230 		goto error;
2231 	}
2232 	p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2233 		"proc_id %d client_id %s\n", glock->type, glock->start,
2234 		glock->length, glock->proc_id, glock->client_id);
2235 error:
2236 	p9_free_req(clnt, req);
2237 	return err;
2238 }
2239 EXPORT_SYMBOL(p9_client_getlock_dotl);
2240 
2241 int p9_client_readlink(struct p9_fid *fid, char **target)
2242 {
2243 	int err;
2244 	struct p9_client *clnt;
2245 	struct p9_req_t *req;
2246 
2247 	err = 0;
2248 	clnt = fid->clnt;
2249 	p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2250 
2251 	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2252 	if (IS_ERR(req))
2253 		return PTR_ERR(req);
2254 
2255 	err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2256 	if (err) {
2257 		trace_9p_protocol_dump(clnt, req->rc);
2258 		goto error;
2259 	}
2260 	p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2261 error:
2262 	p9_free_req(clnt, req);
2263 	return err;
2264 }
2265 EXPORT_SYMBOL(p9_client_readlink);
2266