xref: /openbmc/linux/net/9p/client.c (revision 275876e2)
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 static 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, int status)
419 {
420 	p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
421 
422 	/*
423 	 * This barrier is needed to make sure any change made to req before
424 	 * the other thread wakes up will indeed be seen by the waiting side.
425 	 */
426 	smp_wmb();
427 	req->status = status;
428 
429 	wake_up(req->wq);
430 	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
431 }
432 EXPORT_SYMBOL(p9_client_cb);
433 
434 /**
435  * p9_parse_header - parse header arguments out of a packet
436  * @pdu: packet to parse
437  * @size: size of packet
438  * @type: type of request
439  * @tag: tag of packet
440  * @rewind: set if we need to rewind offset afterwards
441  */
442 
443 int
444 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
445 								int rewind)
446 {
447 	int8_t r_type;
448 	int16_t r_tag;
449 	int32_t r_size;
450 	int offset = pdu->offset;
451 	int err;
452 
453 	pdu->offset = 0;
454 	if (pdu->size == 0)
455 		pdu->size = 7;
456 
457 	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
458 	if (err)
459 		goto rewind_and_exit;
460 
461 	pdu->size = r_size;
462 	pdu->id = r_type;
463 	pdu->tag = r_tag;
464 
465 	p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
466 		 pdu->size, pdu->id, pdu->tag);
467 
468 	if (type)
469 		*type = r_type;
470 	if (tag)
471 		*tag = r_tag;
472 	if (size)
473 		*size = r_size;
474 
475 
476 rewind_and_exit:
477 	if (rewind)
478 		pdu->offset = offset;
479 	return err;
480 }
481 EXPORT_SYMBOL(p9_parse_header);
482 
483 /**
484  * p9_check_errors - check 9p packet for error return and process it
485  * @c: current client instance
486  * @req: request to parse and check for error conditions
487  *
488  * returns error code if one is discovered, otherwise returns 0
489  *
490  * this will have to be more complicated if we have multiple
491  * error packet types
492  */
493 
494 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
495 {
496 	int8_t type;
497 	int err;
498 	int ecode;
499 
500 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
501 	/*
502 	 * dump the response from server
503 	 * This should be after check errors which poplulate pdu_fcall.
504 	 */
505 	trace_9p_protocol_dump(c, req->rc);
506 	if (err) {
507 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
508 		return err;
509 	}
510 	if (type != P9_RERROR && type != P9_RLERROR)
511 		return 0;
512 
513 	if (!p9_is_proto_dotl(c)) {
514 		char *ename;
515 		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
516 				  &ename, &ecode);
517 		if (err)
518 			goto out_err;
519 
520 		if (p9_is_proto_dotu(c))
521 			err = -ecode;
522 
523 		if (!err || !IS_ERR_VALUE(err)) {
524 			err = p9_errstr2errno(ename, strlen(ename));
525 
526 			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
527 				 -ecode, ename);
528 		}
529 		kfree(ename);
530 	} else {
531 		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
532 		err = -ecode;
533 
534 		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
535 	}
536 
537 	return err;
538 
539 out_err:
540 	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
541 
542 	return err;
543 }
544 
545 /**
546  * p9_check_zc_errors - check 9p packet for error return and process it
547  * @c: current client instance
548  * @req: request to parse and check for error conditions
549  * @in_hdrlen: Size of response protocol buffer.
550  *
551  * returns error code if one is discovered, otherwise returns 0
552  *
553  * this will have to be more complicated if we have multiple
554  * error packet types
555  */
556 
557 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
558 			      char *uidata, int in_hdrlen, int kern_buf)
559 {
560 	int err;
561 	int ecode;
562 	int8_t type;
563 	char *ename = NULL;
564 
565 	err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
566 	/*
567 	 * dump the response from server
568 	 * This should be after parse_header which poplulate pdu_fcall.
569 	 */
570 	trace_9p_protocol_dump(c, req->rc);
571 	if (err) {
572 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
573 		return err;
574 	}
575 
576 	if (type != P9_RERROR && type != P9_RLERROR)
577 		return 0;
578 
579 	if (!p9_is_proto_dotl(c)) {
580 		/* Error is reported in string format */
581 		int len;
582 		/* 7 = header size for RERROR; */
583 		int inline_len = in_hdrlen - 7;
584 
585 		len =  req->rc->size - req->rc->offset;
586 		if (len > (P9_ZC_HDR_SZ - 7)) {
587 			err = -EFAULT;
588 			goto out_err;
589 		}
590 
591 		ename = &req->rc->sdata[req->rc->offset];
592 		if (len > inline_len) {
593 			/* We have error in external buffer */
594 			if (kern_buf) {
595 				memcpy(ename + inline_len, uidata,
596 				       len - inline_len);
597 			} else {
598 				err = copy_from_user(ename + inline_len,
599 						     uidata, len - inline_len);
600 				if (err) {
601 					err = -EFAULT;
602 					goto out_err;
603 				}
604 			}
605 		}
606 		ename = NULL;
607 		err = p9pdu_readf(req->rc, c->proto_version, "s?d",
608 				  &ename, &ecode);
609 		if (err)
610 			goto out_err;
611 
612 		if (p9_is_proto_dotu(c))
613 			err = -ecode;
614 
615 		if (!err || !IS_ERR_VALUE(err)) {
616 			err = p9_errstr2errno(ename, strlen(ename));
617 
618 			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
619 				 -ecode, ename);
620 		}
621 		kfree(ename);
622 	} else {
623 		err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
624 		err = -ecode;
625 
626 		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
627 	}
628 	return err;
629 
630 out_err:
631 	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
632 	return err;
633 }
634 
635 static struct p9_req_t *
636 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
637 
638 /**
639  * p9_client_flush - flush (cancel) a request
640  * @c: client state
641  * @oldreq: request to cancel
642  *
643  * This sents a flush for a particular request and links
644  * the flush request to the original request.  The current
645  * code only supports a single flush request although the protocol
646  * allows for multiple flush requests to be sent for a single request.
647  *
648  */
649 
650 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
651 {
652 	struct p9_req_t *req;
653 	int16_t oldtag;
654 	int err;
655 
656 	err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
657 	if (err)
658 		return err;
659 
660 	p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
661 
662 	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
663 	if (IS_ERR(req))
664 		return PTR_ERR(req);
665 
666 	/*
667 	 * if we haven't received a response for oldreq,
668 	 * remove it from the list
669 	 */
670 	if (oldreq->status == REQ_STATUS_SENT)
671 		if (c->trans_mod->cancelled)
672 			c->trans_mod->cancelled(c, oldreq);
673 
674 	p9_free_req(c, req);
675 	return 0;
676 }
677 
678 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
679 					      int8_t type, int req_size,
680 					      const char *fmt, va_list ap)
681 {
682 	int tag, err;
683 	struct p9_req_t *req;
684 
685 	p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
686 
687 	/* we allow for any status other than disconnected */
688 	if (c->status == Disconnected)
689 		return ERR_PTR(-EIO);
690 
691 	/* if status is begin_disconnected we allow only clunk request */
692 	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
693 		return ERR_PTR(-EIO);
694 
695 	tag = P9_NOTAG;
696 	if (type != P9_TVERSION) {
697 		tag = p9_idpool_get(c->tagpool);
698 		if (tag < 0)
699 			return ERR_PTR(-ENOMEM);
700 	}
701 
702 	req = p9_tag_alloc(c, tag, req_size);
703 	if (IS_ERR(req))
704 		return req;
705 
706 	/* marshall the data */
707 	p9pdu_prepare(req->tc, tag, type);
708 	err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
709 	if (err)
710 		goto reterr;
711 	p9pdu_finalize(c, req->tc);
712 	trace_9p_client_req(c, type, tag);
713 	return req;
714 reterr:
715 	p9_free_req(c, req);
716 	return ERR_PTR(err);
717 }
718 
719 /**
720  * p9_client_rpc - issue a request and wait for a response
721  * @c: client session
722  * @type: type of request
723  * @fmt: protocol format string (see protocol.c)
724  *
725  * Returns request structure (which client must free using p9_free_req)
726  */
727 
728 static struct p9_req_t *
729 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
730 {
731 	va_list ap;
732 	int sigpending, err;
733 	unsigned long flags;
734 	struct p9_req_t *req;
735 
736 	va_start(ap, fmt);
737 	req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
738 	va_end(ap);
739 	if (IS_ERR(req))
740 		return req;
741 
742 	if (signal_pending(current)) {
743 		sigpending = 1;
744 		clear_thread_flag(TIF_SIGPENDING);
745 	} else
746 		sigpending = 0;
747 
748 	err = c->trans_mod->request(c, req);
749 	if (err < 0) {
750 		if (err != -ERESTARTSYS && err != -EFAULT)
751 			c->status = Disconnected;
752 		goto reterr;
753 	}
754 again:
755 	/* Wait for the response */
756 	err = wait_event_interruptible(*req->wq,
757 				       req->status >= REQ_STATUS_RCVD);
758 
759 	/*
760 	 * Make sure our req is coherent with regard to updates in other
761 	 * threads - echoes to wmb() in the callback
762 	 */
763 	smp_rmb();
764 
765 	if ((err == -ERESTARTSYS) && (c->status == Connected)
766 				  && (type == P9_TFLUSH)) {
767 		sigpending = 1;
768 		clear_thread_flag(TIF_SIGPENDING);
769 		goto again;
770 	}
771 
772 	if (req->status == REQ_STATUS_ERROR) {
773 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
774 		err = req->t_err;
775 	}
776 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
777 		p9_debug(P9_DEBUG_MUX, "flushing\n");
778 		sigpending = 1;
779 		clear_thread_flag(TIF_SIGPENDING);
780 
781 		if (c->trans_mod->cancel(c, req))
782 			p9_client_flush(c, req);
783 
784 		/* if we received the response anyway, don't signal error */
785 		if (req->status == REQ_STATUS_RCVD)
786 			err = 0;
787 	}
788 	if (sigpending) {
789 		spin_lock_irqsave(&current->sighand->siglock, flags);
790 		recalc_sigpending();
791 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
792 	}
793 	if (err < 0)
794 		goto reterr;
795 
796 	err = p9_check_errors(c, req);
797 	trace_9p_client_res(c, type, req->rc->tag, err);
798 	if (!err)
799 		return req;
800 reterr:
801 	p9_free_req(c, req);
802 	return ERR_PTR(safe_errno(err));
803 }
804 
805 /**
806  * p9_client_zc_rpc - issue a request and wait for a response
807  * @c: client session
808  * @type: type of request
809  * @uidata: user bffer that should be ued for zero copy read
810  * @uodata: user buffer that shoud be user for zero copy write
811  * @inlen: read buffer size
812  * @olen: write buffer size
813  * @hdrlen: reader header size, This is the size of response protocol data
814  * @fmt: protocol format string (see protocol.c)
815  *
816  * Returns request structure (which client must free using p9_free_req)
817  */
818 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
819 					 char *uidata, char *uodata,
820 					 int inlen, int olen, int in_hdrlen,
821 					 int kern_buf, const char *fmt, ...)
822 {
823 	va_list ap;
824 	int sigpending, err;
825 	unsigned long flags;
826 	struct p9_req_t *req;
827 
828 	va_start(ap, fmt);
829 	/*
830 	 * We allocate a inline protocol data of only 4k bytes.
831 	 * The actual content is passed in zero-copy fashion.
832 	 */
833 	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
834 	va_end(ap);
835 	if (IS_ERR(req))
836 		return req;
837 
838 	if (signal_pending(current)) {
839 		sigpending = 1;
840 		clear_thread_flag(TIF_SIGPENDING);
841 	} else
842 		sigpending = 0;
843 
844 	/* If we are called with KERNEL_DS force kern_buf */
845 	if (segment_eq(get_fs(), KERNEL_DS))
846 		kern_buf = 1;
847 
848 	err = c->trans_mod->zc_request(c, req, uidata, uodata,
849 				       inlen, olen, in_hdrlen, kern_buf);
850 	if (err < 0) {
851 		if (err == -EIO)
852 			c->status = Disconnected;
853 		goto reterr;
854 	}
855 	if (req->status == REQ_STATUS_ERROR) {
856 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
857 		err = req->t_err;
858 	}
859 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
860 		p9_debug(P9_DEBUG_MUX, "flushing\n");
861 		sigpending = 1;
862 		clear_thread_flag(TIF_SIGPENDING);
863 
864 		if (c->trans_mod->cancel(c, req))
865 			p9_client_flush(c, req);
866 
867 		/* if we received the response anyway, don't signal error */
868 		if (req->status == REQ_STATUS_RCVD)
869 			err = 0;
870 	}
871 	if (sigpending) {
872 		spin_lock_irqsave(&current->sighand->siglock, flags);
873 		recalc_sigpending();
874 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
875 	}
876 	if (err < 0)
877 		goto reterr;
878 
879 	err = p9_check_zc_errors(c, req, uidata, in_hdrlen, kern_buf);
880 	trace_9p_client_res(c, type, req->rc->tag, err);
881 	if (!err)
882 		return req;
883 reterr:
884 	p9_free_req(c, req);
885 	return ERR_PTR(safe_errno(err));
886 }
887 
888 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
889 {
890 	int ret;
891 	struct p9_fid *fid;
892 	unsigned long flags;
893 
894 	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
895 	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
896 	if (!fid)
897 		return ERR_PTR(-ENOMEM);
898 
899 	ret = p9_idpool_get(clnt->fidpool);
900 	if (ret < 0) {
901 		ret = -ENOSPC;
902 		goto error;
903 	}
904 	fid->fid = ret;
905 
906 	memset(&fid->qid, 0, sizeof(struct p9_qid));
907 	fid->mode = -1;
908 	fid->uid = current_fsuid();
909 	fid->clnt = clnt;
910 	fid->rdir = NULL;
911 	spin_lock_irqsave(&clnt->lock, flags);
912 	list_add(&fid->flist, &clnt->fidlist);
913 	spin_unlock_irqrestore(&clnt->lock, flags);
914 
915 	return fid;
916 
917 error:
918 	kfree(fid);
919 	return ERR_PTR(ret);
920 }
921 
922 static void p9_fid_destroy(struct p9_fid *fid)
923 {
924 	struct p9_client *clnt;
925 	unsigned long flags;
926 
927 	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
928 	clnt = fid->clnt;
929 	p9_idpool_put(fid->fid, clnt->fidpool);
930 	spin_lock_irqsave(&clnt->lock, flags);
931 	list_del(&fid->flist);
932 	spin_unlock_irqrestore(&clnt->lock, flags);
933 	kfree(fid->rdir);
934 	kfree(fid);
935 }
936 
937 static int p9_client_version(struct p9_client *c)
938 {
939 	int err = 0;
940 	struct p9_req_t *req;
941 	char *version;
942 	int msize;
943 
944 	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
945 		 c->msize, c->proto_version);
946 
947 	switch (c->proto_version) {
948 	case p9_proto_2000L:
949 		req = p9_client_rpc(c, P9_TVERSION, "ds",
950 					c->msize, "9P2000.L");
951 		break;
952 	case p9_proto_2000u:
953 		req = p9_client_rpc(c, P9_TVERSION, "ds",
954 					c->msize, "9P2000.u");
955 		break;
956 	case p9_proto_legacy:
957 		req = p9_client_rpc(c, P9_TVERSION, "ds",
958 					c->msize, "9P2000");
959 		break;
960 	default:
961 		return -EINVAL;
962 	}
963 
964 	if (IS_ERR(req))
965 		return PTR_ERR(req);
966 
967 	err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
968 	if (err) {
969 		p9_debug(P9_DEBUG_9P, "version error %d\n", err);
970 		trace_9p_protocol_dump(c, req->rc);
971 		goto error;
972 	}
973 
974 	p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
975 	if (!strncmp(version, "9P2000.L", 8))
976 		c->proto_version = p9_proto_2000L;
977 	else if (!strncmp(version, "9P2000.u", 8))
978 		c->proto_version = p9_proto_2000u;
979 	else if (!strncmp(version, "9P2000", 6))
980 		c->proto_version = p9_proto_legacy;
981 	else {
982 		err = -EREMOTEIO;
983 		goto error;
984 	}
985 
986 	if (msize < c->msize)
987 		c->msize = msize;
988 
989 error:
990 	kfree(version);
991 	p9_free_req(c, req);
992 
993 	return err;
994 }
995 
996 struct p9_client *p9_client_create(const char *dev_name, char *options)
997 {
998 	int err;
999 	struct p9_client *clnt;
1000 	char *client_id;
1001 
1002 	err = 0;
1003 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1004 	if (!clnt)
1005 		return ERR_PTR(-ENOMEM);
1006 
1007 	clnt->trans_mod = NULL;
1008 	clnt->trans = NULL;
1009 
1010 	client_id = utsname()->nodename;
1011 	memcpy(clnt->name, client_id, strlen(client_id) + 1);
1012 
1013 	spin_lock_init(&clnt->lock);
1014 	INIT_LIST_HEAD(&clnt->fidlist);
1015 
1016 	err = p9_tag_init(clnt);
1017 	if (err < 0)
1018 		goto free_client;
1019 
1020 	err = parse_opts(options, clnt);
1021 	if (err < 0)
1022 		goto destroy_tagpool;
1023 
1024 	if (!clnt->trans_mod)
1025 		clnt->trans_mod = v9fs_get_default_trans();
1026 
1027 	if (clnt->trans_mod == NULL) {
1028 		err = -EPROTONOSUPPORT;
1029 		p9_debug(P9_DEBUG_ERROR,
1030 			 "No transport defined or default transport\n");
1031 		goto destroy_tagpool;
1032 	}
1033 
1034 	clnt->fidpool = p9_idpool_create();
1035 	if (IS_ERR(clnt->fidpool)) {
1036 		err = PTR_ERR(clnt->fidpool);
1037 		goto put_trans;
1038 	}
1039 
1040 	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1041 		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1042 
1043 	err = clnt->trans_mod->create(clnt, dev_name, options);
1044 	if (err)
1045 		goto destroy_fidpool;
1046 
1047 	if (clnt->msize > clnt->trans_mod->maxsize)
1048 		clnt->msize = clnt->trans_mod->maxsize;
1049 
1050 	err = p9_client_version(clnt);
1051 	if (err)
1052 		goto close_trans;
1053 
1054 	return clnt;
1055 
1056 close_trans:
1057 	clnt->trans_mod->close(clnt);
1058 destroy_fidpool:
1059 	p9_idpool_destroy(clnt->fidpool);
1060 put_trans:
1061 	v9fs_put_trans(clnt->trans_mod);
1062 destroy_tagpool:
1063 	p9_idpool_destroy(clnt->tagpool);
1064 free_client:
1065 	kfree(clnt);
1066 	return ERR_PTR(err);
1067 }
1068 EXPORT_SYMBOL(p9_client_create);
1069 
1070 void p9_client_destroy(struct p9_client *clnt)
1071 {
1072 	struct p9_fid *fid, *fidptr;
1073 
1074 	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1075 
1076 	if (clnt->trans_mod)
1077 		clnt->trans_mod->close(clnt);
1078 
1079 	v9fs_put_trans(clnt->trans_mod);
1080 
1081 	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1082 		pr_info("Found fid %d not clunked\n", fid->fid);
1083 		p9_fid_destroy(fid);
1084 	}
1085 
1086 	if (clnt->fidpool)
1087 		p9_idpool_destroy(clnt->fidpool);
1088 
1089 	p9_tag_cleanup(clnt);
1090 
1091 	kfree(clnt);
1092 }
1093 EXPORT_SYMBOL(p9_client_destroy);
1094 
1095 void p9_client_disconnect(struct p9_client *clnt)
1096 {
1097 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1098 	clnt->status = Disconnected;
1099 }
1100 EXPORT_SYMBOL(p9_client_disconnect);
1101 
1102 void p9_client_begin_disconnect(struct p9_client *clnt)
1103 {
1104 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1105 	clnt->status = BeginDisconnect;
1106 }
1107 EXPORT_SYMBOL(p9_client_begin_disconnect);
1108 
1109 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1110 	char *uname, kuid_t n_uname, char *aname)
1111 {
1112 	int err = 0;
1113 	struct p9_req_t *req;
1114 	struct p9_fid *fid;
1115 	struct p9_qid qid;
1116 
1117 
1118 	p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1119 		 afid ? afid->fid : -1, uname, aname);
1120 	fid = p9_fid_create(clnt);
1121 	if (IS_ERR(fid)) {
1122 		err = PTR_ERR(fid);
1123 		fid = NULL;
1124 		goto error;
1125 	}
1126 
1127 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1128 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1129 	if (IS_ERR(req)) {
1130 		err = PTR_ERR(req);
1131 		goto error;
1132 	}
1133 
1134 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1135 	if (err) {
1136 		trace_9p_protocol_dump(clnt, req->rc);
1137 		p9_free_req(clnt, req);
1138 		goto error;
1139 	}
1140 
1141 	p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1142 		 qid.type, (unsigned long long)qid.path, qid.version);
1143 
1144 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1145 
1146 	p9_free_req(clnt, req);
1147 	return fid;
1148 
1149 error:
1150 	if (fid)
1151 		p9_fid_destroy(fid);
1152 	return ERR_PTR(err);
1153 }
1154 EXPORT_SYMBOL(p9_client_attach);
1155 
1156 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1157 		char **wnames, int clone)
1158 {
1159 	int err;
1160 	struct p9_client *clnt;
1161 	struct p9_fid *fid;
1162 	struct p9_qid *wqids;
1163 	struct p9_req_t *req;
1164 	uint16_t nwqids, count;
1165 
1166 	err = 0;
1167 	wqids = NULL;
1168 	clnt = oldfid->clnt;
1169 	if (clone) {
1170 		fid = p9_fid_create(clnt);
1171 		if (IS_ERR(fid)) {
1172 			err = PTR_ERR(fid);
1173 			fid = NULL;
1174 			goto error;
1175 		}
1176 
1177 		fid->uid = oldfid->uid;
1178 	} else
1179 		fid = oldfid;
1180 
1181 
1182 	p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1183 		 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1184 
1185 	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1186 								nwname, wnames);
1187 	if (IS_ERR(req)) {
1188 		err = PTR_ERR(req);
1189 		goto error;
1190 	}
1191 
1192 	err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1193 	if (err) {
1194 		trace_9p_protocol_dump(clnt, req->rc);
1195 		p9_free_req(clnt, req);
1196 		goto clunk_fid;
1197 	}
1198 	p9_free_req(clnt, req);
1199 
1200 	p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1201 
1202 	if (nwqids != nwname) {
1203 		err = -ENOENT;
1204 		goto clunk_fid;
1205 	}
1206 
1207 	for (count = 0; count < nwqids; count++)
1208 		p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1209 			count, wqids[count].type,
1210 			(unsigned long long)wqids[count].path,
1211 			wqids[count].version);
1212 
1213 	if (nwname)
1214 		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1215 	else
1216 		fid->qid = oldfid->qid;
1217 
1218 	kfree(wqids);
1219 	return fid;
1220 
1221 clunk_fid:
1222 	kfree(wqids);
1223 	p9_client_clunk(fid);
1224 	fid = NULL;
1225 
1226 error:
1227 	if (fid && (fid != oldfid))
1228 		p9_fid_destroy(fid);
1229 
1230 	return ERR_PTR(err);
1231 }
1232 EXPORT_SYMBOL(p9_client_walk);
1233 
1234 int p9_client_open(struct p9_fid *fid, int mode)
1235 {
1236 	int err;
1237 	struct p9_client *clnt;
1238 	struct p9_req_t *req;
1239 	struct p9_qid qid;
1240 	int iounit;
1241 
1242 	clnt = fid->clnt;
1243 	p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1244 		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1245 	err = 0;
1246 
1247 	if (fid->mode != -1)
1248 		return -EINVAL;
1249 
1250 	if (p9_is_proto_dotl(clnt))
1251 		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1252 	else
1253 		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1254 	if (IS_ERR(req)) {
1255 		err = PTR_ERR(req);
1256 		goto error;
1257 	}
1258 
1259 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1260 	if (err) {
1261 		trace_9p_protocol_dump(clnt, req->rc);
1262 		goto free_and_error;
1263 	}
1264 
1265 	p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1266 		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1267 		(unsigned long long)qid.path, qid.version, iounit);
1268 
1269 	fid->mode = mode;
1270 	fid->iounit = iounit;
1271 
1272 free_and_error:
1273 	p9_free_req(clnt, req);
1274 error:
1275 	return err;
1276 }
1277 EXPORT_SYMBOL(p9_client_open);
1278 
1279 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1280 		kgid_t gid, struct p9_qid *qid)
1281 {
1282 	int err = 0;
1283 	struct p9_client *clnt;
1284 	struct p9_req_t *req;
1285 	int iounit;
1286 
1287 	p9_debug(P9_DEBUG_9P,
1288 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1289 			ofid->fid, name, flags, mode,
1290 		 	from_kgid(&init_user_ns, gid));
1291 	clnt = ofid->clnt;
1292 
1293 	if (ofid->mode != -1)
1294 		return -EINVAL;
1295 
1296 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1297 			mode, gid);
1298 	if (IS_ERR(req)) {
1299 		err = PTR_ERR(req);
1300 		goto error;
1301 	}
1302 
1303 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1304 	if (err) {
1305 		trace_9p_protocol_dump(clnt, req->rc);
1306 		goto free_and_error;
1307 	}
1308 
1309 	p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1310 			qid->type,
1311 			(unsigned long long)qid->path,
1312 			qid->version, iounit);
1313 
1314 	ofid->mode = mode;
1315 	ofid->iounit = iounit;
1316 
1317 free_and_error:
1318 	p9_free_req(clnt, req);
1319 error:
1320 	return err;
1321 }
1322 EXPORT_SYMBOL(p9_client_create_dotl);
1323 
1324 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1325 		     char *extension)
1326 {
1327 	int err;
1328 	struct p9_client *clnt;
1329 	struct p9_req_t *req;
1330 	struct p9_qid qid;
1331 	int iounit;
1332 
1333 	p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1334 						fid->fid, name, perm, mode);
1335 	err = 0;
1336 	clnt = fid->clnt;
1337 
1338 	if (fid->mode != -1)
1339 		return -EINVAL;
1340 
1341 	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1342 				mode, extension);
1343 	if (IS_ERR(req)) {
1344 		err = PTR_ERR(req);
1345 		goto error;
1346 	}
1347 
1348 	err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1349 	if (err) {
1350 		trace_9p_protocol_dump(clnt, req->rc);
1351 		goto free_and_error;
1352 	}
1353 
1354 	p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1355 				qid.type,
1356 				(unsigned long long)qid.path,
1357 				qid.version, iounit);
1358 
1359 	fid->mode = mode;
1360 	fid->iounit = iounit;
1361 
1362 free_and_error:
1363 	p9_free_req(clnt, req);
1364 error:
1365 	return err;
1366 }
1367 EXPORT_SYMBOL(p9_client_fcreate);
1368 
1369 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
1370 		struct p9_qid *qid)
1371 {
1372 	int err = 0;
1373 	struct p9_client *clnt;
1374 	struct p9_req_t *req;
1375 
1376 	p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1377 			dfid->fid, name, symtgt);
1378 	clnt = dfid->clnt;
1379 
1380 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1381 			gid);
1382 	if (IS_ERR(req)) {
1383 		err = PTR_ERR(req);
1384 		goto error;
1385 	}
1386 
1387 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1388 	if (err) {
1389 		trace_9p_protocol_dump(clnt, req->rc);
1390 		goto free_and_error;
1391 	}
1392 
1393 	p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1394 			qid->type, (unsigned long long)qid->path, qid->version);
1395 
1396 free_and_error:
1397 	p9_free_req(clnt, req);
1398 error:
1399 	return err;
1400 }
1401 EXPORT_SYMBOL(p9_client_symlink);
1402 
1403 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1404 {
1405 	struct p9_client *clnt;
1406 	struct p9_req_t *req;
1407 
1408 	p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1409 			dfid->fid, oldfid->fid, newname);
1410 	clnt = dfid->clnt;
1411 	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1412 			newname);
1413 	if (IS_ERR(req))
1414 		return PTR_ERR(req);
1415 
1416 	p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1417 	p9_free_req(clnt, req);
1418 	return 0;
1419 }
1420 EXPORT_SYMBOL(p9_client_link);
1421 
1422 int p9_client_fsync(struct p9_fid *fid, int datasync)
1423 {
1424 	int err;
1425 	struct p9_client *clnt;
1426 	struct p9_req_t *req;
1427 
1428 	p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1429 			fid->fid, datasync);
1430 	err = 0;
1431 	clnt = fid->clnt;
1432 
1433 	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1434 	if (IS_ERR(req)) {
1435 		err = PTR_ERR(req);
1436 		goto error;
1437 	}
1438 
1439 	p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1440 
1441 	p9_free_req(clnt, req);
1442 
1443 error:
1444 	return err;
1445 }
1446 EXPORT_SYMBOL(p9_client_fsync);
1447 
1448 int p9_client_clunk(struct p9_fid *fid)
1449 {
1450 	int err;
1451 	struct p9_client *clnt;
1452 	struct p9_req_t *req;
1453 	int retries = 0;
1454 
1455 	if (!fid) {
1456 		pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1457 			__func__, task_pid_nr(current));
1458 		dump_stack();
1459 		return 0;
1460 	}
1461 
1462 again:
1463 	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1464 								retries);
1465 	err = 0;
1466 	clnt = fid->clnt;
1467 
1468 	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1469 	if (IS_ERR(req)) {
1470 		err = PTR_ERR(req);
1471 		goto error;
1472 	}
1473 
1474 	p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1475 
1476 	p9_free_req(clnt, req);
1477 error:
1478 	/*
1479 	 * Fid is not valid even after a failed clunk
1480 	 * If interrupted, retry once then give up and
1481 	 * leak fid until umount.
1482 	 */
1483 	if (err == -ERESTARTSYS) {
1484 		if (retries++ == 0)
1485 			goto again;
1486 	} else
1487 		p9_fid_destroy(fid);
1488 	return err;
1489 }
1490 EXPORT_SYMBOL(p9_client_clunk);
1491 
1492 int p9_client_remove(struct p9_fid *fid)
1493 {
1494 	int err;
1495 	struct p9_client *clnt;
1496 	struct p9_req_t *req;
1497 
1498 	p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1499 	err = 0;
1500 	clnt = fid->clnt;
1501 
1502 	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1503 	if (IS_ERR(req)) {
1504 		err = PTR_ERR(req);
1505 		goto error;
1506 	}
1507 
1508 	p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1509 
1510 	p9_free_req(clnt, req);
1511 error:
1512 	if (err == -ERESTARTSYS)
1513 		p9_client_clunk(fid);
1514 	else
1515 		p9_fid_destroy(fid);
1516 	return err;
1517 }
1518 EXPORT_SYMBOL(p9_client_remove);
1519 
1520 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1521 {
1522 	int err = 0;
1523 	struct p9_req_t *req;
1524 	struct p9_client *clnt;
1525 
1526 	p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1527 		   dfid->fid, name, flags);
1528 
1529 	clnt = dfid->clnt;
1530 	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1531 	if (IS_ERR(req)) {
1532 		err = PTR_ERR(req);
1533 		goto error;
1534 	}
1535 	p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1536 
1537 	p9_free_req(clnt, req);
1538 error:
1539 	return err;
1540 }
1541 EXPORT_SYMBOL(p9_client_unlinkat);
1542 
1543 int
1544 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1545 								u32 count)
1546 {
1547 	char *dataptr;
1548 	int kernel_buf = 0;
1549 	struct p9_req_t *req;
1550 	struct p9_client *clnt;
1551 	int err, rsize, non_zc = 0;
1552 
1553 
1554 	p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1555 		   fid->fid, (unsigned long long) offset, count);
1556 	err = 0;
1557 	clnt = fid->clnt;
1558 
1559 	rsize = fid->iounit;
1560 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1561 		rsize = clnt->msize - P9_IOHDRSZ;
1562 
1563 	if (count < rsize)
1564 		rsize = count;
1565 
1566 	/* Don't bother zerocopy for small IO (< 1024) */
1567 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1568 		char *indata;
1569 		if (data) {
1570 			kernel_buf = 1;
1571 			indata = data;
1572 		} else
1573 			indata = (__force char *)udata;
1574 		/*
1575 		 * response header len is 11
1576 		 * PDU Header(7) + IO Size (4)
1577 		 */
1578 		req = p9_client_zc_rpc(clnt, P9_TREAD, indata, NULL, rsize, 0,
1579 				       11, kernel_buf, "dqd", fid->fid,
1580 				       offset, rsize);
1581 	} else {
1582 		non_zc = 1;
1583 		req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1584 				    rsize);
1585 	}
1586 	if (IS_ERR(req)) {
1587 		err = PTR_ERR(req);
1588 		goto error;
1589 	}
1590 
1591 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1592 	if (err) {
1593 		trace_9p_protocol_dump(clnt, req->rc);
1594 		goto free_and_error;
1595 	}
1596 
1597 	p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1598 
1599 	if (non_zc) {
1600 		if (data) {
1601 			memmove(data, dataptr, count);
1602 		} else {
1603 			err = copy_to_user(udata, dataptr, count);
1604 			if (err) {
1605 				err = -EFAULT;
1606 				goto free_and_error;
1607 			}
1608 		}
1609 	}
1610 	p9_free_req(clnt, req);
1611 	return count;
1612 
1613 free_and_error:
1614 	p9_free_req(clnt, req);
1615 error:
1616 	return err;
1617 }
1618 EXPORT_SYMBOL(p9_client_read);
1619 
1620 int
1621 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1622 							u64 offset, u32 count)
1623 {
1624 	int err, rsize;
1625 	int kernel_buf = 0;
1626 	struct p9_client *clnt;
1627 	struct p9_req_t *req;
1628 
1629 	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1630 				fid->fid, (unsigned long long) offset, count);
1631 	err = 0;
1632 	clnt = fid->clnt;
1633 
1634 	rsize = fid->iounit;
1635 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1636 		rsize = clnt->msize - P9_IOHDRSZ;
1637 
1638 	if (count < rsize)
1639 		rsize = count;
1640 
1641 	/* Don't bother zerocopy for small IO (< 1024) */
1642 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1643 		char *odata;
1644 		if (data) {
1645 			kernel_buf = 1;
1646 			odata = data;
1647 		} else
1648 			odata = (char *)udata;
1649 		req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, odata, 0, rsize,
1650 				       P9_ZC_HDR_SZ, kernel_buf, "dqd",
1651 				       fid->fid, offset, rsize);
1652 	} else {
1653 		if (data)
1654 			req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1655 					    offset, rsize, data);
1656 		else
1657 			req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1658 					    offset, rsize, udata);
1659 	}
1660 	if (IS_ERR(req)) {
1661 		err = PTR_ERR(req);
1662 		goto error;
1663 	}
1664 
1665 	err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1666 	if (err) {
1667 		trace_9p_protocol_dump(clnt, req->rc);
1668 		goto free_and_error;
1669 	}
1670 
1671 	p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1672 
1673 	p9_free_req(clnt, req);
1674 	return count;
1675 
1676 free_and_error:
1677 	p9_free_req(clnt, req);
1678 error:
1679 	return err;
1680 }
1681 EXPORT_SYMBOL(p9_client_write);
1682 
1683 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1684 {
1685 	int err;
1686 	struct p9_client *clnt;
1687 	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1688 	struct p9_req_t *req;
1689 	u16 ignored;
1690 
1691 	p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1692 
1693 	if (!ret)
1694 		return ERR_PTR(-ENOMEM);
1695 
1696 	err = 0;
1697 	clnt = fid->clnt;
1698 
1699 	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1700 	if (IS_ERR(req)) {
1701 		err = PTR_ERR(req);
1702 		goto error;
1703 	}
1704 
1705 	err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1706 	if (err) {
1707 		trace_9p_protocol_dump(clnt, req->rc);
1708 		p9_free_req(clnt, req);
1709 		goto error;
1710 	}
1711 
1712 	p9_debug(P9_DEBUG_9P,
1713 		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1714 		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1715 		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1716 		"<<<    uid=%d gid=%d n_muid=%d\n",
1717 		ret->size, ret->type, ret->dev, ret->qid.type,
1718 		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1719 		ret->atime, ret->mtime, (unsigned long long)ret->length,
1720 		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1721 		from_kuid(&init_user_ns, ret->n_uid),
1722 		from_kgid(&init_user_ns, ret->n_gid),
1723 		from_kuid(&init_user_ns, ret->n_muid));
1724 
1725 	p9_free_req(clnt, req);
1726 	return ret;
1727 
1728 error:
1729 	kfree(ret);
1730 	return ERR_PTR(err);
1731 }
1732 EXPORT_SYMBOL(p9_client_stat);
1733 
1734 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1735 							u64 request_mask)
1736 {
1737 	int err;
1738 	struct p9_client *clnt;
1739 	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1740 								GFP_KERNEL);
1741 	struct p9_req_t *req;
1742 
1743 	p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1744 							fid->fid, request_mask);
1745 
1746 	if (!ret)
1747 		return ERR_PTR(-ENOMEM);
1748 
1749 	err = 0;
1750 	clnt = fid->clnt;
1751 
1752 	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1753 	if (IS_ERR(req)) {
1754 		err = PTR_ERR(req);
1755 		goto error;
1756 	}
1757 
1758 	err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1759 	if (err) {
1760 		trace_9p_protocol_dump(clnt, req->rc);
1761 		p9_free_req(clnt, req);
1762 		goto error;
1763 	}
1764 
1765 	p9_debug(P9_DEBUG_9P,
1766 		"<<< RGETATTR st_result_mask=%lld\n"
1767 		"<<< qid=%x.%llx.%x\n"
1768 		"<<< st_mode=%8.8x st_nlink=%llu\n"
1769 		"<<< st_uid=%d st_gid=%d\n"
1770 		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1771 		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1772 		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1773 		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1774 		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1775 		"<<< st_gen=%lld st_data_version=%lld",
1776 		ret->st_result_mask, ret->qid.type, ret->qid.path,
1777 		ret->qid.version, ret->st_mode, ret->st_nlink,
1778 		from_kuid(&init_user_ns, ret->st_uid),
1779 		from_kgid(&init_user_ns, ret->st_gid),
1780 		ret->st_rdev, ret->st_size, ret->st_blksize,
1781 		ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1782 		ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1783 		ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1784 		ret->st_gen, ret->st_data_version);
1785 
1786 	p9_free_req(clnt, req);
1787 	return ret;
1788 
1789 error:
1790 	kfree(ret);
1791 	return ERR_PTR(err);
1792 }
1793 EXPORT_SYMBOL(p9_client_getattr_dotl);
1794 
1795 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1796 {
1797 	int ret;
1798 
1799 	/* NOTE: size shouldn't include its own length */
1800 	/* size[2] type[2] dev[4] qid[13] */
1801 	/* mode[4] atime[4] mtime[4] length[8]*/
1802 	/* name[s] uid[s] gid[s] muid[s] */
1803 	ret = 2+4+13+4+4+4+8+2+2+2+2;
1804 
1805 	if (wst->name)
1806 		ret += strlen(wst->name);
1807 	if (wst->uid)
1808 		ret += strlen(wst->uid);
1809 	if (wst->gid)
1810 		ret += strlen(wst->gid);
1811 	if (wst->muid)
1812 		ret += strlen(wst->muid);
1813 
1814 	if ((proto_version == p9_proto_2000u) ||
1815 		(proto_version == p9_proto_2000L)) {
1816 		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1817 		if (wst->extension)
1818 			ret += strlen(wst->extension);
1819 	}
1820 
1821 	return ret;
1822 }
1823 
1824 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1825 {
1826 	int err;
1827 	struct p9_req_t *req;
1828 	struct p9_client *clnt;
1829 
1830 	err = 0;
1831 	clnt = fid->clnt;
1832 	wst->size = p9_client_statsize(wst, clnt->proto_version);
1833 	p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1834 	p9_debug(P9_DEBUG_9P,
1835 		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1836 		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1837 		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1838 		"     uid=%d gid=%d n_muid=%d\n",
1839 		wst->size, wst->type, wst->dev, wst->qid.type,
1840 		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1841 		wst->atime, wst->mtime, (unsigned long long)wst->length,
1842 		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1843 		from_kuid(&init_user_ns, wst->n_uid),
1844 		from_kgid(&init_user_ns, wst->n_gid),
1845 		from_kuid(&init_user_ns, wst->n_muid));
1846 
1847 	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1848 	if (IS_ERR(req)) {
1849 		err = PTR_ERR(req);
1850 		goto error;
1851 	}
1852 
1853 	p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1854 
1855 	p9_free_req(clnt, req);
1856 error:
1857 	return err;
1858 }
1859 EXPORT_SYMBOL(p9_client_wstat);
1860 
1861 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1862 {
1863 	int err;
1864 	struct p9_req_t *req;
1865 	struct p9_client *clnt;
1866 
1867 	err = 0;
1868 	clnt = fid->clnt;
1869 	p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1870 	p9_debug(P9_DEBUG_9P,
1871 		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1872 		"    atime_sec=%lld atime_nsec=%lld\n"
1873 		"    mtime_sec=%lld mtime_nsec=%lld\n",
1874 		p9attr->valid, p9attr->mode,
1875 		from_kuid(&init_user_ns, p9attr->uid),
1876 		from_kgid(&init_user_ns, p9attr->gid),
1877 		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1878 		p9attr->mtime_sec, p9attr->mtime_nsec);
1879 
1880 	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1881 
1882 	if (IS_ERR(req)) {
1883 		err = PTR_ERR(req);
1884 		goto error;
1885 	}
1886 	p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1887 	p9_free_req(clnt, req);
1888 error:
1889 	return err;
1890 }
1891 EXPORT_SYMBOL(p9_client_setattr);
1892 
1893 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1894 {
1895 	int err;
1896 	struct p9_req_t *req;
1897 	struct p9_client *clnt;
1898 
1899 	err = 0;
1900 	clnt = fid->clnt;
1901 
1902 	p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1903 
1904 	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1905 	if (IS_ERR(req)) {
1906 		err = PTR_ERR(req);
1907 		goto error;
1908 	}
1909 
1910 	err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1911 		&sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1912 		&sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1913 	if (err) {
1914 		trace_9p_protocol_dump(clnt, req->rc);
1915 		p9_free_req(clnt, req);
1916 		goto error;
1917 	}
1918 
1919 	p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1920 		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1921 		"fsid %llu namelen %ld\n",
1922 		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1923 		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1924 		sb->fsid, (long int)sb->namelen);
1925 
1926 	p9_free_req(clnt, req);
1927 error:
1928 	return err;
1929 }
1930 EXPORT_SYMBOL(p9_client_statfs);
1931 
1932 int p9_client_rename(struct p9_fid *fid,
1933 		     struct p9_fid *newdirfid, const char *name)
1934 {
1935 	int err;
1936 	struct p9_req_t *req;
1937 	struct p9_client *clnt;
1938 
1939 	err = 0;
1940 	clnt = fid->clnt;
1941 
1942 	p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1943 			fid->fid, newdirfid->fid, name);
1944 
1945 	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1946 			newdirfid->fid, name);
1947 	if (IS_ERR(req)) {
1948 		err = PTR_ERR(req);
1949 		goto error;
1950 	}
1951 
1952 	p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1953 
1954 	p9_free_req(clnt, req);
1955 error:
1956 	return err;
1957 }
1958 EXPORT_SYMBOL(p9_client_rename);
1959 
1960 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1961 		       struct p9_fid *newdirfid, const char *new_name)
1962 {
1963 	int err;
1964 	struct p9_req_t *req;
1965 	struct p9_client *clnt;
1966 
1967 	err = 0;
1968 	clnt = olddirfid->clnt;
1969 
1970 	p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1971 		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1972 		   newdirfid->fid, new_name);
1973 
1974 	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1975 			    old_name, newdirfid->fid, new_name);
1976 	if (IS_ERR(req)) {
1977 		err = PTR_ERR(req);
1978 		goto error;
1979 	}
1980 
1981 	p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1982 		   newdirfid->fid, new_name);
1983 
1984 	p9_free_req(clnt, req);
1985 error:
1986 	return err;
1987 }
1988 EXPORT_SYMBOL(p9_client_renameat);
1989 
1990 /*
1991  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1992  */
1993 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1994 				const char *attr_name, u64 *attr_size)
1995 {
1996 	int err;
1997 	struct p9_req_t *req;
1998 	struct p9_client *clnt;
1999 	struct p9_fid *attr_fid;
2000 
2001 	err = 0;
2002 	clnt = file_fid->clnt;
2003 	attr_fid = p9_fid_create(clnt);
2004 	if (IS_ERR(attr_fid)) {
2005 		err = PTR_ERR(attr_fid);
2006 		attr_fid = NULL;
2007 		goto error;
2008 	}
2009 	p9_debug(P9_DEBUG_9P,
2010 		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2011 		file_fid->fid, attr_fid->fid, attr_name);
2012 
2013 	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2014 			file_fid->fid, attr_fid->fid, attr_name);
2015 	if (IS_ERR(req)) {
2016 		err = PTR_ERR(req);
2017 		goto error;
2018 	}
2019 	err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2020 	if (err) {
2021 		trace_9p_protocol_dump(clnt, req->rc);
2022 		p9_free_req(clnt, req);
2023 		goto clunk_fid;
2024 	}
2025 	p9_free_req(clnt, req);
2026 	p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2027 		attr_fid->fid, *attr_size);
2028 	return attr_fid;
2029 clunk_fid:
2030 	p9_client_clunk(attr_fid);
2031 	attr_fid = NULL;
2032 error:
2033 	if (attr_fid && (attr_fid != file_fid))
2034 		p9_fid_destroy(attr_fid);
2035 
2036 	return ERR_PTR(err);
2037 }
2038 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2039 
2040 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2041 			u64 attr_size, int flags)
2042 {
2043 	int err;
2044 	struct p9_req_t *req;
2045 	struct p9_client *clnt;
2046 
2047 	p9_debug(P9_DEBUG_9P,
2048 		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2049 		fid->fid, name, (long long)attr_size, flags);
2050 	err = 0;
2051 	clnt = fid->clnt;
2052 	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2053 			fid->fid, name, attr_size, flags);
2054 	if (IS_ERR(req)) {
2055 		err = PTR_ERR(req);
2056 		goto error;
2057 	}
2058 	p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2059 	p9_free_req(clnt, req);
2060 error:
2061 	return err;
2062 }
2063 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2064 
2065 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2066 {
2067 	int err, rsize, non_zc = 0;
2068 	struct p9_client *clnt;
2069 	struct p9_req_t *req;
2070 	char *dataptr;
2071 
2072 	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2073 				fid->fid, (unsigned long long) offset, count);
2074 
2075 	err = 0;
2076 	clnt = fid->clnt;
2077 
2078 	rsize = fid->iounit;
2079 	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2080 		rsize = clnt->msize - P9_READDIRHDRSZ;
2081 
2082 	if (count < rsize)
2083 		rsize = count;
2084 
2085 	/* Don't bother zerocopy for small IO (< 1024) */
2086 	if (clnt->trans_mod->zc_request && rsize > 1024) {
2087 		/*
2088 		 * response header len is 11
2089 		 * PDU Header(7) + IO Size (4)
2090 		 */
2091 		req = p9_client_zc_rpc(clnt, P9_TREADDIR, data, NULL, rsize, 0,
2092 				       11, 1, "dqd", fid->fid, offset, rsize);
2093 	} else {
2094 		non_zc = 1;
2095 		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2096 				    offset, rsize);
2097 	}
2098 	if (IS_ERR(req)) {
2099 		err = PTR_ERR(req);
2100 		goto error;
2101 	}
2102 
2103 	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2104 	if (err) {
2105 		trace_9p_protocol_dump(clnt, req->rc);
2106 		goto free_and_error;
2107 	}
2108 
2109 	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2110 
2111 	if (non_zc)
2112 		memmove(data, dataptr, count);
2113 
2114 	p9_free_req(clnt, req);
2115 	return count;
2116 
2117 free_and_error:
2118 	p9_free_req(clnt, req);
2119 error:
2120 	return err;
2121 }
2122 EXPORT_SYMBOL(p9_client_readdir);
2123 
2124 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2125 			dev_t rdev, kgid_t gid, struct p9_qid *qid)
2126 {
2127 	int err;
2128 	struct p9_client *clnt;
2129 	struct p9_req_t *req;
2130 
2131 	err = 0;
2132 	clnt = fid->clnt;
2133 	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2134 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2135 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2136 		MAJOR(rdev), MINOR(rdev), gid);
2137 	if (IS_ERR(req))
2138 		return PTR_ERR(req);
2139 
2140 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2141 	if (err) {
2142 		trace_9p_protocol_dump(clnt, req->rc);
2143 		goto error;
2144 	}
2145 	p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2146 				(unsigned long long)qid->path, qid->version);
2147 
2148 error:
2149 	p9_free_req(clnt, req);
2150 	return err;
2151 
2152 }
2153 EXPORT_SYMBOL(p9_client_mknod_dotl);
2154 
2155 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2156 				kgid_t gid, struct p9_qid *qid)
2157 {
2158 	int err;
2159 	struct p9_client *clnt;
2160 	struct p9_req_t *req;
2161 
2162 	err = 0;
2163 	clnt = fid->clnt;
2164 	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2165 		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2166 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2167 		gid);
2168 	if (IS_ERR(req))
2169 		return PTR_ERR(req);
2170 
2171 	err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2172 	if (err) {
2173 		trace_9p_protocol_dump(clnt, req->rc);
2174 		goto error;
2175 	}
2176 	p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2177 				(unsigned long long)qid->path, qid->version);
2178 
2179 error:
2180 	p9_free_req(clnt, req);
2181 	return err;
2182 
2183 }
2184 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2185 
2186 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2187 {
2188 	int err;
2189 	struct p9_client *clnt;
2190 	struct p9_req_t *req;
2191 
2192 	err = 0;
2193 	clnt = fid->clnt;
2194 	p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2195 			"start %lld length %lld proc_id %d client_id %s\n",
2196 			fid->fid, flock->type, flock->flags, flock->start,
2197 			flock->length, flock->proc_id, flock->client_id);
2198 
2199 	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2200 				flock->flags, flock->start, flock->length,
2201 					flock->proc_id, flock->client_id);
2202 
2203 	if (IS_ERR(req))
2204 		return PTR_ERR(req);
2205 
2206 	err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2207 	if (err) {
2208 		trace_9p_protocol_dump(clnt, req->rc);
2209 		goto error;
2210 	}
2211 	p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2212 error:
2213 	p9_free_req(clnt, req);
2214 	return err;
2215 
2216 }
2217 EXPORT_SYMBOL(p9_client_lock_dotl);
2218 
2219 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2220 {
2221 	int err;
2222 	struct p9_client *clnt;
2223 	struct p9_req_t *req;
2224 
2225 	err = 0;
2226 	clnt = fid->clnt;
2227 	p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2228 		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2229 		glock->start, glock->length, glock->proc_id, glock->client_id);
2230 
2231 	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2232 		glock->start, glock->length, glock->proc_id, glock->client_id);
2233 
2234 	if (IS_ERR(req))
2235 		return PTR_ERR(req);
2236 
2237 	err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2238 			&glock->start, &glock->length, &glock->proc_id,
2239 			&glock->client_id);
2240 	if (err) {
2241 		trace_9p_protocol_dump(clnt, req->rc);
2242 		goto error;
2243 	}
2244 	p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2245 		"proc_id %d client_id %s\n", glock->type, glock->start,
2246 		glock->length, glock->proc_id, glock->client_id);
2247 error:
2248 	p9_free_req(clnt, req);
2249 	return err;
2250 }
2251 EXPORT_SYMBOL(p9_client_getlock_dotl);
2252 
2253 int p9_client_readlink(struct p9_fid *fid, char **target)
2254 {
2255 	int err;
2256 	struct p9_client *clnt;
2257 	struct p9_req_t *req;
2258 
2259 	err = 0;
2260 	clnt = fid->clnt;
2261 	p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2262 
2263 	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2264 	if (IS_ERR(req))
2265 		return PTR_ERR(req);
2266 
2267 	err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2268 	if (err) {
2269 		trace_9p_protocol_dump(clnt, req->rc);
2270 		goto error;
2271 	}
2272 	p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2273 error:
2274 	p9_free_req(clnt, req);
2275 	return err;
2276 }
2277 EXPORT_SYMBOL(p9_client_readlink);
2278