xref: /linux/net/9p/client.c (revision 4cd82a5bb0f68236f67b1678bc9e6348a42241ed)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * net/9p/clnt.c
4  *
5  * 9P Client
6  *
7  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
8  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
9  */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/module.h>
14 #include <linux/errno.h>
15 #include <linux/fs.h>
16 #include <linux/poll.h>
17 #include <linux/idr.h>
18 #include <linux/mutex.h>
19 #include <linux/slab.h>
20 #include <linux/sched/signal.h>
21 #include <linux/uaccess.h>
22 #include <linux/uio.h>
23 #include <net/9p/9p.h>
24 #include <linux/parser.h>
25 #include <linux/seq_file.h>
26 #include <net/9p/client.h>
27 #include <net/9p/transport.h>
28 #include "protocol.h"
29 
30 #define CREATE_TRACE_POINTS
31 #include <trace/events/9p.h>
32 
33 #define DEFAULT_MSIZE (128 * 1024)
34 
35 /*
36   * Client Option Parsing (code inspired by NFS code)
37   *  - a little lazy - parse all client options
38   */
39 
40 enum {
41 	Opt_msize,
42 	Opt_trans,
43 	Opt_legacy,
44 	Opt_version,
45 	Opt_err,
46 };
47 
48 static const match_table_t tokens = {
49 	{Opt_msize, "msize=%u"},
50 	{Opt_legacy, "noextend"},
51 	{Opt_trans, "trans=%s"},
52 	{Opt_version, "version=%s"},
53 	{Opt_err, NULL},
54 };
55 
56 inline int p9_is_proto_dotl(struct p9_client *clnt)
57 {
58 	return clnt->proto_version == p9_proto_2000L;
59 }
60 EXPORT_SYMBOL(p9_is_proto_dotl);
61 
62 inline int p9_is_proto_dotu(struct p9_client *clnt)
63 {
64 	return clnt->proto_version == p9_proto_2000u;
65 }
66 EXPORT_SYMBOL(p9_is_proto_dotu);
67 
68 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
69 {
70 	if (clnt->msize != DEFAULT_MSIZE)
71 		seq_printf(m, ",msize=%u", clnt->msize);
72 	seq_printf(m, ",trans=%s", clnt->trans_mod->name);
73 
74 	switch (clnt->proto_version) {
75 	case p9_proto_legacy:
76 		seq_puts(m, ",noextend");
77 		break;
78 	case p9_proto_2000u:
79 		seq_puts(m, ",version=9p2000.u");
80 		break;
81 	case p9_proto_2000L:
82 		/* Default */
83 		break;
84 	}
85 
86 	if (clnt->trans_mod->show_options)
87 		return clnt->trans_mod->show_options(m, clnt);
88 	return 0;
89 }
90 EXPORT_SYMBOL(p9_show_client_options);
91 
92 /*
93  * Some error codes are taken directly from the server replies,
94  * make sure they are valid.
95  */
96 static int safe_errno(int err)
97 {
98 	if ((err > 0) || (err < -MAX_ERRNO)) {
99 		p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
100 		return -EPROTO;
101 	}
102 	return err;
103 }
104 
105 
106 /* Interpret mount option for protocol version */
107 static int get_protocol_version(char *s)
108 {
109 	int version = -EINVAL;
110 
111 	if (!strcmp(s, "9p2000")) {
112 		version = p9_proto_legacy;
113 		p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
114 	} else if (!strcmp(s, "9p2000.u")) {
115 		version = p9_proto_2000u;
116 		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
117 	} else if (!strcmp(s, "9p2000.L")) {
118 		version = p9_proto_2000L;
119 		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
120 	} else
121 		pr_info("Unknown protocol version %s\n", s);
122 
123 	return version;
124 }
125 
126 /**
127  * parse_opts - parse mount options into client structure
128  * @opts: options string passed from mount
129  * @clnt: existing v9fs client information
130  *
131  * Return 0 upon success, -ERRNO upon failure
132  */
133 
134 static int parse_opts(char *opts, struct p9_client *clnt)
135 {
136 	char *options, *tmp_options;
137 	char *p;
138 	substring_t args[MAX_OPT_ARGS];
139 	int option;
140 	char *s;
141 	int ret = 0;
142 
143 	clnt->proto_version = p9_proto_2000L;
144 	clnt->msize = DEFAULT_MSIZE;
145 
146 	if (!opts)
147 		return 0;
148 
149 	tmp_options = kstrdup(opts, GFP_KERNEL);
150 	if (!tmp_options) {
151 		p9_debug(P9_DEBUG_ERROR,
152 			 "failed to allocate copy of option string\n");
153 		return -ENOMEM;
154 	}
155 	options = tmp_options;
156 
157 	while ((p = strsep(&options, ",")) != NULL) {
158 		int token, r;
159 		if (!*p)
160 			continue;
161 		token = match_token(p, tokens, args);
162 		switch (token) {
163 		case Opt_msize:
164 			r = match_int(&args[0], &option);
165 			if (r < 0) {
166 				p9_debug(P9_DEBUG_ERROR,
167 					 "integer field, but no integer?\n");
168 				ret = r;
169 				continue;
170 			}
171 			if (option < 4096) {
172 				p9_debug(P9_DEBUG_ERROR,
173 					 "msize should be at least 4k\n");
174 				ret = -EINVAL;
175 				continue;
176 			}
177 			clnt->msize = option;
178 			break;
179 		case Opt_trans:
180 			s = match_strdup(&args[0]);
181 			if (!s) {
182 				ret = -ENOMEM;
183 				p9_debug(P9_DEBUG_ERROR,
184 					 "problem allocating copy of trans arg\n");
185 				goto free_and_return;
186 			}
187 
188 			v9fs_put_trans(clnt->trans_mod);
189 			clnt->trans_mod = v9fs_get_trans_by_name(s);
190 			if (clnt->trans_mod == NULL) {
191 				pr_info("Could not find request transport: %s\n",
192 					s);
193 				ret = -EINVAL;
194 			}
195 			kfree(s);
196 			break;
197 		case Opt_legacy:
198 			clnt->proto_version = p9_proto_legacy;
199 			break;
200 		case Opt_version:
201 			s = match_strdup(&args[0]);
202 			if (!s) {
203 				ret = -ENOMEM;
204 				p9_debug(P9_DEBUG_ERROR,
205 					 "problem allocating copy of version arg\n");
206 				goto free_and_return;
207 			}
208 			r = get_protocol_version(s);
209 			if (r < 0)
210 				ret = r;
211 			else
212 				clnt->proto_version = r;
213 			kfree(s);
214 			break;
215 		default:
216 			continue;
217 		}
218 	}
219 
220 free_and_return:
221 	if (ret)
222 		v9fs_put_trans(clnt->trans_mod);
223 	kfree(tmp_options);
224 	return ret;
225 }
226 
227 static int p9_fcall_init(struct p9_client *c, struct p9_fcall *fc,
228 			 int alloc_msize)
229 {
230 	if (likely(c->fcall_cache) && alloc_msize == c->msize) {
231 		fc->sdata = kmem_cache_alloc(c->fcall_cache, GFP_NOFS);
232 		fc->cache = c->fcall_cache;
233 	} else {
234 		fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
235 		fc->cache = NULL;
236 	}
237 	if (!fc->sdata)
238 		return -ENOMEM;
239 	fc->capacity = alloc_msize;
240 	return 0;
241 }
242 
243 void p9_fcall_fini(struct p9_fcall *fc)
244 {
245 	/* sdata can be NULL for interrupted requests in trans_rdma,
246 	 * and kmem_cache_free does not do NULL-check for us
247 	 */
248 	if (unlikely(!fc->sdata))
249 		return;
250 
251 	if (fc->cache)
252 		kmem_cache_free(fc->cache, fc->sdata);
253 	else
254 		kfree(fc->sdata);
255 }
256 EXPORT_SYMBOL(p9_fcall_fini);
257 
258 static struct kmem_cache *p9_req_cache;
259 
260 /**
261  * p9_tag_alloc - Allocate a new request.
262  * @c: Client session.
263  * @type: Transaction type.
264  * @max_size: Maximum packet size for this request.
265  *
266  * Context: Process context.
267  * Return: Pointer to new request.
268  */
269 static struct p9_req_t *
270 p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
271 {
272 	struct p9_req_t *req = kmem_cache_alloc(p9_req_cache, GFP_NOFS);
273 	int alloc_msize = min(c->msize, max_size);
274 	int tag;
275 
276 	if (!req)
277 		return ERR_PTR(-ENOMEM);
278 
279 	if (p9_fcall_init(c, &req->tc, alloc_msize))
280 		goto free_req;
281 	if (p9_fcall_init(c, &req->rc, alloc_msize))
282 		goto free;
283 
284 	p9pdu_reset(&req->tc);
285 	p9pdu_reset(&req->rc);
286 	req->t_err = 0;
287 	req->status = REQ_STATUS_ALLOC;
288 	init_waitqueue_head(&req->wq);
289 	INIT_LIST_HEAD(&req->req_list);
290 
291 	idr_preload(GFP_NOFS);
292 	spin_lock_irq(&c->lock);
293 	if (type == P9_TVERSION)
294 		tag = idr_alloc(&c->reqs, req, P9_NOTAG, P9_NOTAG + 1,
295 				GFP_NOWAIT);
296 	else
297 		tag = idr_alloc(&c->reqs, req, 0, P9_NOTAG, GFP_NOWAIT);
298 	req->tc.tag = tag;
299 	spin_unlock_irq(&c->lock);
300 	idr_preload_end();
301 	if (tag < 0)
302 		goto free;
303 
304 	/* Init ref to two because in the general case there is one ref
305 	 * that is put asynchronously by a writer thread, one ref
306 	 * temporarily given by p9_tag_lookup and put by p9_client_cb
307 	 * in the recv thread, and one ref put by p9_tag_remove in the
308 	 * main thread. The only exception is virtio that does not use
309 	 * p9_tag_lookup but does not have a writer thread either
310 	 * (the write happens synchronously in the request/zc_request
311 	 * callback), so p9_client_cb eats the second ref there
312 	 * as the pointer is duplicated directly by virtqueue_add_sgs()
313 	 */
314 	refcount_set(&req->refcount.refcount, 2);
315 
316 	return req;
317 
318 free:
319 	p9_fcall_fini(&req->tc);
320 	p9_fcall_fini(&req->rc);
321 free_req:
322 	kmem_cache_free(p9_req_cache, req);
323 	return ERR_PTR(-ENOMEM);
324 }
325 
326 /**
327  * p9_tag_lookup - Look up a request by tag.
328  * @c: Client session.
329  * @tag: Transaction ID.
330  *
331  * Context: Any context.
332  * Return: A request, or %NULL if there is no request with that tag.
333  */
334 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
335 {
336 	struct p9_req_t *req;
337 
338 	rcu_read_lock();
339 again:
340 	req = idr_find(&c->reqs, tag);
341 	if (req) {
342 		/* We have to be careful with the req found under rcu_read_lock
343 		 * Thanks to SLAB_TYPESAFE_BY_RCU we can safely try to get the
344 		 * ref again without corrupting other data, then check again
345 		 * that the tag matches once we have the ref
346 		 */
347 		if (!p9_req_try_get(req))
348 			goto again;
349 		if (req->tc.tag != tag) {
350 			p9_req_put(req);
351 			goto again;
352 		}
353 	}
354 	rcu_read_unlock();
355 
356 	return req;
357 }
358 EXPORT_SYMBOL(p9_tag_lookup);
359 
360 /**
361  * p9_tag_remove - Remove a tag.
362  * @c: Client session.
363  * @r: Request of reference.
364  *
365  * Context: Any context.
366  */
367 static int p9_tag_remove(struct p9_client *c, struct p9_req_t *r)
368 {
369 	unsigned long flags;
370 	u16 tag = r->tc.tag;
371 
372 	p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
373 	spin_lock_irqsave(&c->lock, flags);
374 	idr_remove(&c->reqs, tag);
375 	spin_unlock_irqrestore(&c->lock, flags);
376 	return p9_req_put(r);
377 }
378 
379 static void p9_req_free(struct kref *ref)
380 {
381 	struct p9_req_t *r = container_of(ref, struct p9_req_t, refcount);
382 	p9_fcall_fini(&r->tc);
383 	p9_fcall_fini(&r->rc);
384 	kmem_cache_free(p9_req_cache, r);
385 }
386 
387 int p9_req_put(struct p9_req_t *r)
388 {
389 	return kref_put(&r->refcount, p9_req_free);
390 }
391 EXPORT_SYMBOL(p9_req_put);
392 
393 /**
394  * p9_tag_cleanup - cleans up tags structure and reclaims resources
395  * @c:  v9fs client struct
396  *
397  * This frees resources associated with the tags structure
398  *
399  */
400 static void p9_tag_cleanup(struct p9_client *c)
401 {
402 	struct p9_req_t *req;
403 	int id;
404 
405 	rcu_read_lock();
406 	idr_for_each_entry(&c->reqs, req, id) {
407 		pr_info("Tag %d still in use\n", id);
408 		if (p9_tag_remove(c, req) == 0)
409 			pr_warn("Packet with tag %d has still references",
410 				req->tc.tag);
411 	}
412 	rcu_read_unlock();
413 }
414 
415 /**
416  * p9_client_cb - call back from transport to client
417  * @c: client state
418  * @req: request received
419  * @status: request status, one of REQ_STATUS_*
420  *
421  */
422 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
423 {
424 	p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc.tag);
425 
426 	/*
427 	 * This barrier is needed to make sure any change made to req before
428 	 * the status change is visible to another thread
429 	 */
430 	smp_wmb();
431 	req->status = status;
432 
433 	wake_up(&req->wq);
434 	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc.tag);
435 	p9_req_put(req);
436 }
437 EXPORT_SYMBOL(p9_client_cb);
438 
439 /**
440  * p9_parse_header - parse header arguments out of a packet
441  * @pdu: packet to parse
442  * @size: size of packet
443  * @type: type of request
444  * @tag: tag of packet
445  * @rewind: set if we need to rewind offset afterwards
446  */
447 
448 int
449 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
450 								int rewind)
451 {
452 	int8_t r_type;
453 	int16_t r_tag;
454 	int32_t r_size;
455 	int offset = pdu->offset;
456 	int err;
457 
458 	pdu->offset = 0;
459 
460 	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
461 	if (err)
462 		goto rewind_and_exit;
463 
464 	if (type)
465 		*type = r_type;
466 	if (tag)
467 		*tag = r_tag;
468 	if (size)
469 		*size = r_size;
470 
471 	if (pdu->size != r_size || r_size < 7) {
472 		err = -EINVAL;
473 		goto rewind_and_exit;
474 	}
475 
476 	pdu->id = r_type;
477 	pdu->tag = r_tag;
478 
479 	p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
480 		 pdu->size, pdu->id, pdu->tag);
481 
482 rewind_and_exit:
483 	if (rewind)
484 		pdu->offset = offset;
485 	return err;
486 }
487 EXPORT_SYMBOL(p9_parse_header);
488 
489 /**
490  * p9_check_errors - check 9p packet for error return and process it
491  * @c: current client instance
492  * @req: request to parse and check for error conditions
493  *
494  * returns error code if one is discovered, otherwise returns 0
495  *
496  * this will have to be more complicated if we have multiple
497  * error packet types
498  */
499 
500 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
501 {
502 	int8_t type;
503 	int err;
504 	int ecode;
505 
506 	err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
507 	if (req->rc.size >= c->msize) {
508 		p9_debug(P9_DEBUG_ERROR,
509 			 "requested packet size too big: %d\n",
510 			 req->rc.size);
511 		return -EIO;
512 	}
513 	/*
514 	 * dump the response from server
515 	 * This should be after check errors which poplulate pdu_fcall.
516 	 */
517 	trace_9p_protocol_dump(c, &req->rc);
518 	if (err) {
519 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
520 		return err;
521 	}
522 	if (type != P9_RERROR && type != P9_RLERROR)
523 		return 0;
524 
525 	if (!p9_is_proto_dotl(c)) {
526 		char *ename;
527 		err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
528 				  &ename, &ecode);
529 		if (err)
530 			goto out_err;
531 
532 		if (p9_is_proto_dotu(c) && ecode < 512)
533 			err = -ecode;
534 
535 		if (!err) {
536 			err = p9_errstr2errno(ename, strlen(ename));
537 
538 			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
539 				 -ecode, ename);
540 		}
541 		kfree(ename);
542 	} else {
543 		err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
544 		if (err)
545 			goto out_err;
546 		err = -ecode;
547 
548 		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
549 	}
550 
551 	return err;
552 
553 out_err:
554 	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
555 
556 	return err;
557 }
558 
559 /**
560  * p9_check_zc_errors - check 9p packet for error return and process it
561  * @c: current client instance
562  * @req: request to parse and check for error conditions
563  * @uidata: external buffer containing error
564  * @in_hdrlen: Size of response protocol buffer.
565  *
566  * returns error code if one is discovered, otherwise returns 0
567  *
568  * this will have to be more complicated if we have multiple
569  * error packet types
570  */
571 
572 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
573 			      struct iov_iter *uidata, int in_hdrlen)
574 {
575 	int err;
576 	int ecode;
577 	int8_t type;
578 	char *ename = NULL;
579 
580 	err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
581 	/*
582 	 * dump the response from server
583 	 * This should be after parse_header which poplulate pdu_fcall.
584 	 */
585 	trace_9p_protocol_dump(c, &req->rc);
586 	if (err) {
587 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
588 		return err;
589 	}
590 
591 	if (type != P9_RERROR && type != P9_RLERROR)
592 		return 0;
593 
594 	if (!p9_is_proto_dotl(c)) {
595 		/* Error is reported in string format */
596 		int len;
597 		/* 7 = header size for RERROR; */
598 		int inline_len = in_hdrlen - 7;
599 
600 		len = req->rc.size - req->rc.offset;
601 		if (len > (P9_ZC_HDR_SZ - 7)) {
602 			err = -EFAULT;
603 			goto out_err;
604 		}
605 
606 		ename = &req->rc.sdata[req->rc.offset];
607 		if (len > inline_len) {
608 			/* We have error in external buffer */
609 			if (!copy_from_iter_full(ename + inline_len,
610 					     len - inline_len, uidata)) {
611 				err = -EFAULT;
612 				goto out_err;
613 			}
614 		}
615 		ename = NULL;
616 		err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
617 				  &ename, &ecode);
618 		if (err)
619 			goto out_err;
620 
621 		if (p9_is_proto_dotu(c) && ecode < 512)
622 			err = -ecode;
623 
624 		if (!err) {
625 			err = p9_errstr2errno(ename, strlen(ename));
626 
627 			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
628 				 -ecode, ename);
629 		}
630 		kfree(ename);
631 	} else {
632 		err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
633 		err = -ecode;
634 
635 		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
636 	}
637 	return err;
638 
639 out_err:
640 	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
641 	return err;
642 }
643 
644 static struct p9_req_t *
645 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
646 
647 /**
648  * p9_client_flush - flush (cancel) a request
649  * @c: client state
650  * @oldreq: request to cancel
651  *
652  * This sents a flush for a particular request and links
653  * the flush request to the original request.  The current
654  * code only supports a single flush request although the protocol
655  * allows for multiple flush requests to be sent for a single request.
656  *
657  */
658 
659 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
660 {
661 	struct p9_req_t *req;
662 	int16_t oldtag;
663 	int err;
664 
665 	err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
666 	if (err)
667 		return err;
668 
669 	p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
670 
671 	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
672 	if (IS_ERR(req))
673 		return PTR_ERR(req);
674 
675 	/*
676 	 * if we haven't received a response for oldreq,
677 	 * remove it from the list
678 	 */
679 	if (oldreq->status == REQ_STATUS_SENT) {
680 		if (c->trans_mod->cancelled)
681 			c->trans_mod->cancelled(c, oldreq);
682 	}
683 
684 	p9_tag_remove(c, req);
685 	return 0;
686 }
687 
688 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
689 					      int8_t type, int req_size,
690 					      const char *fmt, va_list ap)
691 {
692 	int err;
693 	struct p9_req_t *req;
694 
695 	p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
696 
697 	/* we allow for any status other than disconnected */
698 	if (c->status == Disconnected)
699 		return ERR_PTR(-EIO);
700 
701 	/* if status is begin_disconnected we allow only clunk request */
702 	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
703 		return ERR_PTR(-EIO);
704 
705 	req = p9_tag_alloc(c, type, req_size);
706 	if (IS_ERR(req))
707 		return req;
708 
709 	/* marshall the data */
710 	p9pdu_prepare(&req->tc, req->tc.tag, type);
711 	err = p9pdu_vwritef(&req->tc, c->proto_version, fmt, ap);
712 	if (err)
713 		goto reterr;
714 	p9pdu_finalize(c, &req->tc);
715 	trace_9p_client_req(c, type, req->tc.tag);
716 	return req;
717 reterr:
718 	p9_tag_remove(c, req);
719 	/* We have to put also the 2nd reference as it won't be used */
720 	p9_req_put(req);
721 	return ERR_PTR(err);
722 }
723 
724 /**
725  * p9_client_rpc - issue a request and wait for a response
726  * @c: client session
727  * @type: type of request
728  * @fmt: protocol format string (see protocol.c)
729  *
730  * Returns request structure (which client must free using p9_tag_remove)
731  */
732 
733 static struct p9_req_t *
734 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
735 {
736 	va_list ap;
737 	int sigpending, err;
738 	unsigned long flags;
739 	struct p9_req_t *req;
740 
741 	va_start(ap, fmt);
742 	req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
743 	va_end(ap);
744 	if (IS_ERR(req))
745 		return req;
746 
747 	if (signal_pending(current)) {
748 		sigpending = 1;
749 		clear_thread_flag(TIF_SIGPENDING);
750 	} else
751 		sigpending = 0;
752 
753 	err = c->trans_mod->request(c, req);
754 	if (err < 0) {
755 		/* write won't happen */
756 		p9_req_put(req);
757 		if (err != -ERESTARTSYS && err != -EFAULT)
758 			c->status = Disconnected;
759 		goto recalc_sigpending;
760 	}
761 again:
762 	/* Wait for the response */
763 	err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
764 
765 	/*
766 	 * Make sure our req is coherent with regard to updates in other
767 	 * threads - echoes to wmb() in the callback
768 	 */
769 	smp_rmb();
770 
771 	if ((err == -ERESTARTSYS) && (c->status == Connected)
772 				  && (type == P9_TFLUSH)) {
773 		sigpending = 1;
774 		clear_thread_flag(TIF_SIGPENDING);
775 		goto again;
776 	}
777 
778 	if (req->status == REQ_STATUS_ERROR) {
779 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
780 		err = req->t_err;
781 	}
782 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
783 		p9_debug(P9_DEBUG_MUX, "flushing\n");
784 		sigpending = 1;
785 		clear_thread_flag(TIF_SIGPENDING);
786 
787 		if (c->trans_mod->cancel(c, req))
788 			p9_client_flush(c, req);
789 
790 		/* if we received the response anyway, don't signal error */
791 		if (req->status == REQ_STATUS_RCVD)
792 			err = 0;
793 	}
794 recalc_sigpending:
795 	if (sigpending) {
796 		spin_lock_irqsave(&current->sighand->siglock, flags);
797 		recalc_sigpending();
798 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
799 	}
800 	if (err < 0)
801 		goto reterr;
802 
803 	err = p9_check_errors(c, req);
804 	trace_9p_client_res(c, type, req->rc.tag, err);
805 	if (!err)
806 		return req;
807 reterr:
808 	p9_tag_remove(c, req);
809 	return ERR_PTR(safe_errno(err));
810 }
811 
812 /**
813  * p9_client_zc_rpc - issue a request and wait for a response
814  * @c: client session
815  * @type: type of request
816  * @uidata: destination for zero copy read
817  * @uodata: source for zero copy write
818  * @inlen: read buffer size
819  * @olen: write buffer size
820  * @in_hdrlen: reader header size, This is the size of response protocol data
821  * @fmt: protocol format string (see protocol.c)
822  *
823  * Returns request structure (which client must free using p9_tag_remove)
824  */
825 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
826 					 struct iov_iter *uidata,
827 					 struct iov_iter *uodata,
828 					 int inlen, int olen, int in_hdrlen,
829 					 const char *fmt, ...)
830 {
831 	va_list ap;
832 	int sigpending, err;
833 	unsigned long flags;
834 	struct p9_req_t *req;
835 
836 	va_start(ap, fmt);
837 	/*
838 	 * We allocate a inline protocol data of only 4k bytes.
839 	 * The actual content is passed in zero-copy fashion.
840 	 */
841 	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
842 	va_end(ap);
843 	if (IS_ERR(req))
844 		return req;
845 
846 	if (signal_pending(current)) {
847 		sigpending = 1;
848 		clear_thread_flag(TIF_SIGPENDING);
849 	} else
850 		sigpending = 0;
851 
852 	err = c->trans_mod->zc_request(c, req, uidata, uodata,
853 				       inlen, olen, in_hdrlen);
854 	if (err < 0) {
855 		if (err == -EIO)
856 			c->status = Disconnected;
857 		if (err != -ERESTARTSYS)
858 			goto recalc_sigpending;
859 	}
860 	if (req->status == REQ_STATUS_ERROR) {
861 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
862 		err = req->t_err;
863 	}
864 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
865 		p9_debug(P9_DEBUG_MUX, "flushing\n");
866 		sigpending = 1;
867 		clear_thread_flag(TIF_SIGPENDING);
868 
869 		if (c->trans_mod->cancel(c, req))
870 			p9_client_flush(c, req);
871 
872 		/* if we received the response anyway, don't signal error */
873 		if (req->status == REQ_STATUS_RCVD)
874 			err = 0;
875 	}
876 recalc_sigpending:
877 	if (sigpending) {
878 		spin_lock_irqsave(&current->sighand->siglock, flags);
879 		recalc_sigpending();
880 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
881 	}
882 	if (err < 0)
883 		goto reterr;
884 
885 	err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
886 	trace_9p_client_res(c, type, req->rc.tag, err);
887 	if (!err)
888 		return req;
889 reterr:
890 	p9_tag_remove(c, req);
891 	return ERR_PTR(safe_errno(err));
892 }
893 
894 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
895 {
896 	int ret;
897 	struct p9_fid *fid;
898 
899 	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
900 	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
901 	if (!fid)
902 		return NULL;
903 
904 	memset(&fid->qid, 0, sizeof(struct p9_qid));
905 	fid->mode = -1;
906 	fid->uid = current_fsuid();
907 	fid->clnt = clnt;
908 	fid->rdir = NULL;
909 	fid->fid = 0;
910 	refcount_set(&fid->count, 1);
911 
912 	idr_preload(GFP_KERNEL);
913 	spin_lock_irq(&clnt->lock);
914 	ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
915 			    GFP_NOWAIT);
916 	spin_unlock_irq(&clnt->lock);
917 	idr_preload_end();
918 	if (!ret)
919 		return fid;
920 
921 	kfree(fid);
922 	return NULL;
923 }
924 
925 static void p9_fid_destroy(struct p9_fid *fid)
926 {
927 	struct p9_client *clnt;
928 	unsigned long flags;
929 
930 	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
931 	clnt = fid->clnt;
932 	spin_lock_irqsave(&clnt->lock, flags);
933 	idr_remove(&clnt->fids, fid->fid);
934 	spin_unlock_irqrestore(&clnt->lock, flags);
935 	kfree(fid->rdir);
936 	kfree(fid);
937 }
938 
939 static int p9_client_version(struct p9_client *c)
940 {
941 	int err = 0;
942 	struct p9_req_t *req;
943 	char *version = NULL;
944 	int msize;
945 
946 	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
947 		 c->msize, c->proto_version);
948 
949 	switch (c->proto_version) {
950 	case p9_proto_2000L:
951 		req = p9_client_rpc(c, P9_TVERSION, "ds",
952 					c->msize, "9P2000.L");
953 		break;
954 	case p9_proto_2000u:
955 		req = p9_client_rpc(c, P9_TVERSION, "ds",
956 					c->msize, "9P2000.u");
957 		break;
958 	case p9_proto_legacy:
959 		req = p9_client_rpc(c, P9_TVERSION, "ds",
960 					c->msize, "9P2000");
961 		break;
962 	default:
963 		return -EINVAL;
964 	}
965 
966 	if (IS_ERR(req))
967 		return PTR_ERR(req);
968 
969 	err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version);
970 	if (err) {
971 		p9_debug(P9_DEBUG_9P, "version error %d\n", err);
972 		trace_9p_protocol_dump(c, &req->rc);
973 		goto error;
974 	}
975 
976 	p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
977 	if (!strncmp(version, "9P2000.L", 8))
978 		c->proto_version = p9_proto_2000L;
979 	else if (!strncmp(version, "9P2000.u", 8))
980 		c->proto_version = p9_proto_2000u;
981 	else if (!strncmp(version, "9P2000", 6))
982 		c->proto_version = p9_proto_legacy;
983 	else {
984 		p9_debug(P9_DEBUG_ERROR,
985 			 "server returned an unknown version: %s\n", version);
986 		err = -EREMOTEIO;
987 		goto error;
988 	}
989 
990 	if (msize < 4096) {
991 		p9_debug(P9_DEBUG_ERROR,
992 			 "server returned a msize < 4096: %d\n", msize);
993 		err = -EREMOTEIO;
994 		goto error;
995 	}
996 	if (msize < c->msize)
997 		c->msize = msize;
998 
999 error:
1000 	kfree(version);
1001 	p9_tag_remove(c, req);
1002 
1003 	return err;
1004 }
1005 
1006 struct p9_client *p9_client_create(const char *dev_name, char *options)
1007 {
1008 	int err;
1009 	struct p9_client *clnt;
1010 	char *client_id;
1011 
1012 	err = 0;
1013 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1014 	if (!clnt)
1015 		return ERR_PTR(-ENOMEM);
1016 
1017 	clnt->trans_mod = NULL;
1018 	clnt->trans = NULL;
1019 	clnt->fcall_cache = NULL;
1020 
1021 	client_id = utsname()->nodename;
1022 	memcpy(clnt->name, client_id, strlen(client_id) + 1);
1023 
1024 	spin_lock_init(&clnt->lock);
1025 	idr_init(&clnt->fids);
1026 	idr_init(&clnt->reqs);
1027 
1028 	err = parse_opts(options, clnt);
1029 	if (err < 0)
1030 		goto free_client;
1031 
1032 	if (!clnt->trans_mod)
1033 		clnt->trans_mod = v9fs_get_default_trans();
1034 
1035 	if (clnt->trans_mod == NULL) {
1036 		err = -EPROTONOSUPPORT;
1037 		p9_debug(P9_DEBUG_ERROR,
1038 			 "No transport defined or default transport\n");
1039 		goto free_client;
1040 	}
1041 
1042 	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1043 		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1044 
1045 	err = clnt->trans_mod->create(clnt, dev_name, options);
1046 	if (err)
1047 		goto put_trans;
1048 
1049 	if (clnt->msize > clnt->trans_mod->maxsize)
1050 		clnt->msize = clnt->trans_mod->maxsize;
1051 
1052 	if (clnt->msize < 4096) {
1053 		p9_debug(P9_DEBUG_ERROR,
1054 			 "Please specify a msize of at least 4k\n");
1055 		err = -EINVAL;
1056 		goto close_trans;
1057 	}
1058 
1059 	err = p9_client_version(clnt);
1060 	if (err)
1061 		goto close_trans;
1062 
1063 	/* P9_HDRSZ + 4 is the smallest packet header we can have that is
1064 	 * followed by data accessed from userspace by read
1065 	 */
1066 	clnt->fcall_cache =
1067 		kmem_cache_create_usercopy("9p-fcall-cache", clnt->msize,
1068 					   0, 0, P9_HDRSZ + 4,
1069 					   clnt->msize - (P9_HDRSZ + 4),
1070 					   NULL);
1071 
1072 	return clnt;
1073 
1074 close_trans:
1075 	clnt->trans_mod->close(clnt);
1076 put_trans:
1077 	v9fs_put_trans(clnt->trans_mod);
1078 free_client:
1079 	kfree(clnt);
1080 	return ERR_PTR(err);
1081 }
1082 EXPORT_SYMBOL(p9_client_create);
1083 
1084 void p9_client_destroy(struct p9_client *clnt)
1085 {
1086 	struct p9_fid *fid;
1087 	int id;
1088 
1089 	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1090 
1091 	if (clnt->trans_mod)
1092 		clnt->trans_mod->close(clnt);
1093 
1094 	v9fs_put_trans(clnt->trans_mod);
1095 
1096 	idr_for_each_entry(&clnt->fids, fid, id) {
1097 		pr_info("Found fid %d not clunked\n", fid->fid);
1098 		p9_fid_destroy(fid);
1099 	}
1100 
1101 	p9_tag_cleanup(clnt);
1102 
1103 	kmem_cache_destroy(clnt->fcall_cache);
1104 	kfree(clnt);
1105 }
1106 EXPORT_SYMBOL(p9_client_destroy);
1107 
1108 void p9_client_disconnect(struct p9_client *clnt)
1109 {
1110 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1111 	clnt->status = Disconnected;
1112 }
1113 EXPORT_SYMBOL(p9_client_disconnect);
1114 
1115 void p9_client_begin_disconnect(struct p9_client *clnt)
1116 {
1117 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1118 	clnt->status = BeginDisconnect;
1119 }
1120 EXPORT_SYMBOL(p9_client_begin_disconnect);
1121 
1122 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1123 	const char *uname, kuid_t n_uname, const char *aname)
1124 {
1125 	int err = 0;
1126 	struct p9_req_t *req;
1127 	struct p9_fid *fid;
1128 	struct p9_qid qid;
1129 
1130 
1131 	p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1132 		 afid ? afid->fid : -1, uname, aname);
1133 	fid = p9_fid_create(clnt);
1134 	if (!fid) {
1135 		err = -ENOMEM;
1136 		goto error;
1137 	}
1138 	fid->uid = n_uname;
1139 
1140 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1141 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1142 	if (IS_ERR(req)) {
1143 		err = PTR_ERR(req);
1144 		goto error;
1145 	}
1146 
1147 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
1148 	if (err) {
1149 		trace_9p_protocol_dump(clnt, &req->rc);
1150 		p9_tag_remove(clnt, req);
1151 		goto error;
1152 	}
1153 
1154 	p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1155 		 qid.type, (unsigned long long)qid.path, qid.version);
1156 
1157 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1158 
1159 	p9_tag_remove(clnt, req);
1160 	return fid;
1161 
1162 error:
1163 	if (fid)
1164 		p9_fid_destroy(fid);
1165 	return ERR_PTR(err);
1166 }
1167 EXPORT_SYMBOL(p9_client_attach);
1168 
1169 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1170 		const unsigned char * const *wnames, int clone)
1171 {
1172 	int err;
1173 	struct p9_client *clnt;
1174 	struct p9_fid *fid;
1175 	struct p9_qid *wqids;
1176 	struct p9_req_t *req;
1177 	uint16_t nwqids, count;
1178 
1179 	err = 0;
1180 	wqids = NULL;
1181 	clnt = oldfid->clnt;
1182 	if (clone) {
1183 		fid = p9_fid_create(clnt);
1184 		if (!fid) {
1185 			err = -ENOMEM;
1186 			goto error;
1187 		}
1188 
1189 		fid->uid = oldfid->uid;
1190 	} else
1191 		fid = oldfid;
1192 
1193 
1194 	p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1195 		 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1196 	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1197 								nwname, wnames);
1198 	if (IS_ERR(req)) {
1199 		err = PTR_ERR(req);
1200 		goto error;
1201 	}
1202 
1203 	err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1204 	if (err) {
1205 		trace_9p_protocol_dump(clnt, &req->rc);
1206 		p9_tag_remove(clnt, req);
1207 		goto clunk_fid;
1208 	}
1209 	p9_tag_remove(clnt, req);
1210 
1211 	p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1212 
1213 	if (nwqids != nwname) {
1214 		err = -ENOENT;
1215 		goto clunk_fid;
1216 	}
1217 
1218 	for (count = 0; count < nwqids; count++)
1219 		p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1220 			count, wqids[count].type,
1221 			(unsigned long long)wqids[count].path,
1222 			wqids[count].version);
1223 
1224 	if (nwname)
1225 		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1226 	else
1227 		memmove(&fid->qid, &oldfid->qid, sizeof(struct p9_qid));
1228 
1229 	kfree(wqids);
1230 	return fid;
1231 
1232 clunk_fid:
1233 	kfree(wqids);
1234 	p9_client_clunk(fid);
1235 	fid = NULL;
1236 
1237 error:
1238 	if (fid && (fid != oldfid))
1239 		p9_fid_destroy(fid);
1240 
1241 	return ERR_PTR(err);
1242 }
1243 EXPORT_SYMBOL(p9_client_walk);
1244 
1245 int p9_client_open(struct p9_fid *fid, int mode)
1246 {
1247 	int err;
1248 	struct p9_client *clnt;
1249 	struct p9_req_t *req;
1250 	struct p9_qid qid;
1251 	int iounit;
1252 
1253 	clnt = fid->clnt;
1254 	p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1255 		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1256 	err = 0;
1257 
1258 	if (fid->mode != -1)
1259 		return -EINVAL;
1260 
1261 	if (p9_is_proto_dotl(clnt))
1262 		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1263 	else
1264 		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1265 	if (IS_ERR(req)) {
1266 		err = PTR_ERR(req);
1267 		goto error;
1268 	}
1269 
1270 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1271 	if (err) {
1272 		trace_9p_protocol_dump(clnt, &req->rc);
1273 		goto free_and_error;
1274 	}
1275 
1276 	p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1277 		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1278 		(unsigned long long)qid.path, qid.version, iounit);
1279 
1280 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1281 	fid->mode = mode;
1282 	fid->iounit = iounit;
1283 
1284 free_and_error:
1285 	p9_tag_remove(clnt, req);
1286 error:
1287 	return err;
1288 }
1289 EXPORT_SYMBOL(p9_client_open);
1290 
1291 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1292 		kgid_t gid, struct p9_qid *qid)
1293 {
1294 	int err = 0;
1295 	struct p9_client *clnt;
1296 	struct p9_req_t *req;
1297 	int iounit;
1298 
1299 	p9_debug(P9_DEBUG_9P,
1300 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1301 			ofid->fid, name, flags, mode,
1302 		 	from_kgid(&init_user_ns, gid));
1303 	clnt = ofid->clnt;
1304 
1305 	if (ofid->mode != -1)
1306 		return -EINVAL;
1307 
1308 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1309 			mode, gid);
1310 	if (IS_ERR(req)) {
1311 		err = PTR_ERR(req);
1312 		goto error;
1313 	}
1314 
1315 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
1316 	if (err) {
1317 		trace_9p_protocol_dump(clnt, &req->rc);
1318 		goto free_and_error;
1319 	}
1320 
1321 	p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1322 			qid->type,
1323 			(unsigned long long)qid->path,
1324 			qid->version, iounit);
1325 
1326 	memmove(&ofid->qid, qid, sizeof(struct p9_qid));
1327 	ofid->mode = mode;
1328 	ofid->iounit = iounit;
1329 
1330 free_and_error:
1331 	p9_tag_remove(clnt, req);
1332 error:
1333 	return err;
1334 }
1335 EXPORT_SYMBOL(p9_client_create_dotl);
1336 
1337 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1338 		     char *extension)
1339 {
1340 	int err;
1341 	struct p9_client *clnt;
1342 	struct p9_req_t *req;
1343 	struct p9_qid qid;
1344 	int iounit;
1345 
1346 	p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1347 						fid->fid, name, perm, mode);
1348 	err = 0;
1349 	clnt = fid->clnt;
1350 
1351 	if (fid->mode != -1)
1352 		return -EINVAL;
1353 
1354 	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1355 				mode, extension);
1356 	if (IS_ERR(req)) {
1357 		err = PTR_ERR(req);
1358 		goto error;
1359 	}
1360 
1361 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1362 	if (err) {
1363 		trace_9p_protocol_dump(clnt, &req->rc);
1364 		goto free_and_error;
1365 	}
1366 
1367 	p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1368 				qid.type,
1369 				(unsigned long long)qid.path,
1370 				qid.version, iounit);
1371 
1372 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1373 	fid->mode = mode;
1374 	fid->iounit = iounit;
1375 
1376 free_and_error:
1377 	p9_tag_remove(clnt, req);
1378 error:
1379 	return err;
1380 }
1381 EXPORT_SYMBOL(p9_client_fcreate);
1382 
1383 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1384 		const char *symtgt, kgid_t gid, struct p9_qid *qid)
1385 {
1386 	int err = 0;
1387 	struct p9_client *clnt;
1388 	struct p9_req_t *req;
1389 
1390 	p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1391 			dfid->fid, name, symtgt);
1392 	clnt = dfid->clnt;
1393 
1394 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1395 			gid);
1396 	if (IS_ERR(req)) {
1397 		err = PTR_ERR(req);
1398 		goto error;
1399 	}
1400 
1401 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
1402 	if (err) {
1403 		trace_9p_protocol_dump(clnt, &req->rc);
1404 		goto free_and_error;
1405 	}
1406 
1407 	p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1408 			qid->type, (unsigned long long)qid->path, qid->version);
1409 
1410 free_and_error:
1411 	p9_tag_remove(clnt, req);
1412 error:
1413 	return err;
1414 }
1415 EXPORT_SYMBOL(p9_client_symlink);
1416 
1417 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1418 {
1419 	struct p9_client *clnt;
1420 	struct p9_req_t *req;
1421 
1422 	p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1423 			dfid->fid, oldfid->fid, newname);
1424 	clnt = dfid->clnt;
1425 	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1426 			newname);
1427 	if (IS_ERR(req))
1428 		return PTR_ERR(req);
1429 
1430 	p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1431 	p9_tag_remove(clnt, req);
1432 	return 0;
1433 }
1434 EXPORT_SYMBOL(p9_client_link);
1435 
1436 int p9_client_fsync(struct p9_fid *fid, int datasync)
1437 {
1438 	int err;
1439 	struct p9_client *clnt;
1440 	struct p9_req_t *req;
1441 
1442 	p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1443 			fid->fid, datasync);
1444 	err = 0;
1445 	clnt = fid->clnt;
1446 
1447 	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1448 	if (IS_ERR(req)) {
1449 		err = PTR_ERR(req);
1450 		goto error;
1451 	}
1452 
1453 	p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1454 
1455 	p9_tag_remove(clnt, req);
1456 
1457 error:
1458 	return err;
1459 }
1460 EXPORT_SYMBOL(p9_client_fsync);
1461 
1462 int p9_client_clunk(struct p9_fid *fid)
1463 {
1464 	int err;
1465 	struct p9_client *clnt;
1466 	struct p9_req_t *req;
1467 	int retries = 0;
1468 
1469 	if (!fid || IS_ERR(fid)) {
1470 		pr_warn("%s (%d): Trying to clunk with invalid fid\n",
1471 			__func__, task_pid_nr(current));
1472 		dump_stack();
1473 		return 0;
1474 	}
1475 	if (!refcount_dec_and_test(&fid->count))
1476 		return 0;
1477 
1478 again:
1479 	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1480 								retries);
1481 	err = 0;
1482 	clnt = fid->clnt;
1483 
1484 	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1485 	if (IS_ERR(req)) {
1486 		err = PTR_ERR(req);
1487 		goto error;
1488 	}
1489 
1490 	p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1491 
1492 	p9_tag_remove(clnt, req);
1493 error:
1494 	/*
1495 	 * Fid is not valid even after a failed clunk
1496 	 * If interrupted, retry once then give up and
1497 	 * leak fid until umount.
1498 	 */
1499 	if (err == -ERESTARTSYS) {
1500 		if (retries++ == 0)
1501 			goto again;
1502 	} else
1503 		p9_fid_destroy(fid);
1504 	return err;
1505 }
1506 EXPORT_SYMBOL(p9_client_clunk);
1507 
1508 int p9_client_remove(struct p9_fid *fid)
1509 {
1510 	int err;
1511 	struct p9_client *clnt;
1512 	struct p9_req_t *req;
1513 
1514 	p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1515 	err = 0;
1516 	clnt = fid->clnt;
1517 
1518 	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1519 	if (IS_ERR(req)) {
1520 		err = PTR_ERR(req);
1521 		goto error;
1522 	}
1523 
1524 	p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1525 
1526 	p9_tag_remove(clnt, req);
1527 error:
1528 	if (err == -ERESTARTSYS)
1529 		p9_client_clunk(fid);
1530 	else
1531 		p9_fid_destroy(fid);
1532 	return err;
1533 }
1534 EXPORT_SYMBOL(p9_client_remove);
1535 
1536 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1537 {
1538 	int err = 0;
1539 	struct p9_req_t *req;
1540 	struct p9_client *clnt;
1541 
1542 	p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1543 		   dfid->fid, name, flags);
1544 
1545 	clnt = dfid->clnt;
1546 	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1547 	if (IS_ERR(req)) {
1548 		err = PTR_ERR(req);
1549 		goto error;
1550 	}
1551 	p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1552 
1553 	p9_tag_remove(clnt, req);
1554 error:
1555 	return err;
1556 }
1557 EXPORT_SYMBOL(p9_client_unlinkat);
1558 
1559 int
1560 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1561 {
1562 	int total = 0;
1563 	*err = 0;
1564 
1565 	while (iov_iter_count(to)) {
1566 		int count;
1567 
1568 		count = p9_client_read_once(fid, offset, to, err);
1569 		if (!count || *err)
1570 			break;
1571 		offset += count;
1572 		total += count;
1573 	}
1574 	return total;
1575 }
1576 EXPORT_SYMBOL(p9_client_read);
1577 
1578 int
1579 p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
1580 		    int *err)
1581 {
1582 	struct p9_client *clnt = fid->clnt;
1583 	struct p9_req_t *req;
1584 	int count = iov_iter_count(to);
1585 	int rsize, non_zc = 0;
1586 	char *dataptr;
1587 
1588 	*err = 0;
1589 	p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1590 		   fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1591 
1592 	rsize = fid->iounit;
1593 	if (!rsize || rsize > clnt->msize - P9_IOHDRSZ)
1594 		rsize = clnt->msize - P9_IOHDRSZ;
1595 
1596 	if (count < rsize)
1597 		rsize = count;
1598 
1599 	/* Don't bother zerocopy for small IO (< 1024) */
1600 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1601 		/* response header len is 11
1602 		 * PDU Header(7) + IO Size (4)
1603 		 */
1604 		req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1605 				       0, 11, "dqd", fid->fid,
1606 				       offset, rsize);
1607 	} else {
1608 		non_zc = 1;
1609 		req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1610 				    rsize);
1611 	}
1612 	if (IS_ERR(req)) {
1613 		*err = PTR_ERR(req);
1614 		return 0;
1615 	}
1616 
1617 	*err = p9pdu_readf(&req->rc, clnt->proto_version,
1618 			   "D", &count, &dataptr);
1619 	if (*err) {
1620 		trace_9p_protocol_dump(clnt, &req->rc);
1621 		p9_tag_remove(clnt, req);
1622 		return 0;
1623 	}
1624 	if (rsize < count) {
1625 		pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1626 		count = rsize;
1627 	}
1628 
1629 	p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1630 
1631 	if (non_zc) {
1632 		int n = copy_to_iter(dataptr, count, to);
1633 
1634 		if (n != count) {
1635 			*err = -EFAULT;
1636 			p9_tag_remove(clnt, req);
1637 			return n;
1638 		}
1639 	} else {
1640 		iov_iter_advance(to, count);
1641 	}
1642 	p9_tag_remove(clnt, req);
1643 	return count;
1644 }
1645 EXPORT_SYMBOL(p9_client_read_once);
1646 
1647 int
1648 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1649 {
1650 	struct p9_client *clnt = fid->clnt;
1651 	struct p9_req_t *req;
1652 	int total = 0;
1653 	*err = 0;
1654 
1655 	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1656 				fid->fid, (unsigned long long) offset,
1657 				iov_iter_count(from));
1658 
1659 	while (iov_iter_count(from)) {
1660 		int count = iov_iter_count(from);
1661 		int rsize = fid->iounit;
1662 		if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1663 			rsize = clnt->msize - P9_IOHDRSZ;
1664 
1665 		if (count < rsize)
1666 			rsize = count;
1667 
1668 		/* Don't bother zerocopy for small IO (< 1024) */
1669 		if (clnt->trans_mod->zc_request && rsize > 1024) {
1670 			req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1671 					       rsize, P9_ZC_HDR_SZ, "dqd",
1672 					       fid->fid, offset, rsize);
1673 		} else {
1674 			req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1675 						    offset, rsize, from);
1676 		}
1677 		if (IS_ERR(req)) {
1678 			*err = PTR_ERR(req);
1679 			break;
1680 		}
1681 
1682 		*err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count);
1683 		if (*err) {
1684 			trace_9p_protocol_dump(clnt, &req->rc);
1685 			p9_tag_remove(clnt, req);
1686 			break;
1687 		}
1688 		if (rsize < count) {
1689 			pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1690 			count = rsize;
1691 		}
1692 
1693 		p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1694 
1695 		p9_tag_remove(clnt, req);
1696 		iov_iter_advance(from, count);
1697 		total += count;
1698 		offset += count;
1699 	}
1700 	return total;
1701 }
1702 EXPORT_SYMBOL(p9_client_write);
1703 
1704 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1705 {
1706 	int err;
1707 	struct p9_client *clnt;
1708 	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1709 	struct p9_req_t *req;
1710 	u16 ignored;
1711 
1712 	p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1713 
1714 	if (!ret)
1715 		return ERR_PTR(-ENOMEM);
1716 
1717 	err = 0;
1718 	clnt = fid->clnt;
1719 
1720 	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1721 	if (IS_ERR(req)) {
1722 		err = PTR_ERR(req);
1723 		goto error;
1724 	}
1725 
1726 	err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
1727 	if (err) {
1728 		trace_9p_protocol_dump(clnt, &req->rc);
1729 		p9_tag_remove(clnt, req);
1730 		goto error;
1731 	}
1732 
1733 	p9_debug(P9_DEBUG_9P,
1734 		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1735 		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1736 		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1737 		"<<<    uid=%d gid=%d n_muid=%d\n",
1738 		ret->size, ret->type, ret->dev, ret->qid.type,
1739 		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1740 		ret->atime, ret->mtime, (unsigned long long)ret->length,
1741 		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1742 		from_kuid(&init_user_ns, ret->n_uid),
1743 		from_kgid(&init_user_ns, ret->n_gid),
1744 		from_kuid(&init_user_ns, ret->n_muid));
1745 
1746 	p9_tag_remove(clnt, req);
1747 	return ret;
1748 
1749 error:
1750 	kfree(ret);
1751 	return ERR_PTR(err);
1752 }
1753 EXPORT_SYMBOL(p9_client_stat);
1754 
1755 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1756 							u64 request_mask)
1757 {
1758 	int err;
1759 	struct p9_client *clnt;
1760 	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1761 								GFP_KERNEL);
1762 	struct p9_req_t *req;
1763 
1764 	p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1765 							fid->fid, request_mask);
1766 
1767 	if (!ret)
1768 		return ERR_PTR(-ENOMEM);
1769 
1770 	err = 0;
1771 	clnt = fid->clnt;
1772 
1773 	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1774 	if (IS_ERR(req)) {
1775 		err = PTR_ERR(req);
1776 		goto error;
1777 	}
1778 
1779 	err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
1780 	if (err) {
1781 		trace_9p_protocol_dump(clnt, &req->rc);
1782 		p9_tag_remove(clnt, req);
1783 		goto error;
1784 	}
1785 
1786 	p9_debug(P9_DEBUG_9P,
1787 		"<<< RGETATTR st_result_mask=%lld\n"
1788 		"<<< qid=%x.%llx.%x\n"
1789 		"<<< st_mode=%8.8x st_nlink=%llu\n"
1790 		"<<< st_uid=%d st_gid=%d\n"
1791 		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1792 		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1793 		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1794 		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1795 		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1796 		"<<< st_gen=%lld st_data_version=%lld\n",
1797 		ret->st_result_mask, ret->qid.type, ret->qid.path,
1798 		ret->qid.version, ret->st_mode, ret->st_nlink,
1799 		from_kuid(&init_user_ns, ret->st_uid),
1800 		from_kgid(&init_user_ns, ret->st_gid),
1801 		ret->st_rdev, ret->st_size, ret->st_blksize,
1802 		ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1803 		ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1804 		ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1805 		ret->st_gen, ret->st_data_version);
1806 
1807 	p9_tag_remove(clnt, req);
1808 	return ret;
1809 
1810 error:
1811 	kfree(ret);
1812 	return ERR_PTR(err);
1813 }
1814 EXPORT_SYMBOL(p9_client_getattr_dotl);
1815 
1816 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1817 {
1818 	int ret;
1819 
1820 	/* NOTE: size shouldn't include its own length */
1821 	/* size[2] type[2] dev[4] qid[13] */
1822 	/* mode[4] atime[4] mtime[4] length[8]*/
1823 	/* name[s] uid[s] gid[s] muid[s] */
1824 	ret = 2+4+13+4+4+4+8+2+2+2+2;
1825 
1826 	if (wst->name)
1827 		ret += strlen(wst->name);
1828 	if (wst->uid)
1829 		ret += strlen(wst->uid);
1830 	if (wst->gid)
1831 		ret += strlen(wst->gid);
1832 	if (wst->muid)
1833 		ret += strlen(wst->muid);
1834 
1835 	if ((proto_version == p9_proto_2000u) ||
1836 		(proto_version == p9_proto_2000L)) {
1837 		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1838 		if (wst->extension)
1839 			ret += strlen(wst->extension);
1840 	}
1841 
1842 	return ret;
1843 }
1844 
1845 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1846 {
1847 	int err;
1848 	struct p9_req_t *req;
1849 	struct p9_client *clnt;
1850 
1851 	err = 0;
1852 	clnt = fid->clnt;
1853 	wst->size = p9_client_statsize(wst, clnt->proto_version);
1854 	p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1855 	p9_debug(P9_DEBUG_9P,
1856 		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1857 		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1858 		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1859 		"     uid=%d gid=%d n_muid=%d\n",
1860 		wst->size, wst->type, wst->dev, wst->qid.type,
1861 		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1862 		wst->atime, wst->mtime, (unsigned long long)wst->length,
1863 		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1864 		from_kuid(&init_user_ns, wst->n_uid),
1865 		from_kgid(&init_user_ns, wst->n_gid),
1866 		from_kuid(&init_user_ns, wst->n_muid));
1867 
1868 	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1869 	if (IS_ERR(req)) {
1870 		err = PTR_ERR(req);
1871 		goto error;
1872 	}
1873 
1874 	p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1875 
1876 	p9_tag_remove(clnt, req);
1877 error:
1878 	return err;
1879 }
1880 EXPORT_SYMBOL(p9_client_wstat);
1881 
1882 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1883 {
1884 	int err;
1885 	struct p9_req_t *req;
1886 	struct p9_client *clnt;
1887 
1888 	err = 0;
1889 	clnt = fid->clnt;
1890 	p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1891 	p9_debug(P9_DEBUG_9P,
1892 		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1893 		"    atime_sec=%lld atime_nsec=%lld\n"
1894 		"    mtime_sec=%lld mtime_nsec=%lld\n",
1895 		p9attr->valid, p9attr->mode,
1896 		from_kuid(&init_user_ns, p9attr->uid),
1897 		from_kgid(&init_user_ns, p9attr->gid),
1898 		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1899 		p9attr->mtime_sec, p9attr->mtime_nsec);
1900 
1901 	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1902 
1903 	if (IS_ERR(req)) {
1904 		err = PTR_ERR(req);
1905 		goto error;
1906 	}
1907 	p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1908 	p9_tag_remove(clnt, req);
1909 error:
1910 	return err;
1911 }
1912 EXPORT_SYMBOL(p9_client_setattr);
1913 
1914 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1915 {
1916 	int err;
1917 	struct p9_req_t *req;
1918 	struct p9_client *clnt;
1919 
1920 	err = 0;
1921 	clnt = fid->clnt;
1922 
1923 	p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1924 
1925 	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1926 	if (IS_ERR(req)) {
1927 		err = PTR_ERR(req);
1928 		goto error;
1929 	}
1930 
1931 	err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1932 			  &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1933 			  &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1934 	if (err) {
1935 		trace_9p_protocol_dump(clnt, &req->rc);
1936 		p9_tag_remove(clnt, req);
1937 		goto error;
1938 	}
1939 
1940 	p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1941 		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1942 		"fsid %llu namelen %ld\n",
1943 		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1944 		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1945 		sb->fsid, (long int)sb->namelen);
1946 
1947 	p9_tag_remove(clnt, req);
1948 error:
1949 	return err;
1950 }
1951 EXPORT_SYMBOL(p9_client_statfs);
1952 
1953 int p9_client_rename(struct p9_fid *fid,
1954 		     struct p9_fid *newdirfid, const char *name)
1955 {
1956 	int err;
1957 	struct p9_req_t *req;
1958 	struct p9_client *clnt;
1959 
1960 	err = 0;
1961 	clnt = fid->clnt;
1962 
1963 	p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1964 			fid->fid, newdirfid->fid, name);
1965 
1966 	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1967 			newdirfid->fid, name);
1968 	if (IS_ERR(req)) {
1969 		err = PTR_ERR(req);
1970 		goto error;
1971 	}
1972 
1973 	p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1974 
1975 	p9_tag_remove(clnt, req);
1976 error:
1977 	return err;
1978 }
1979 EXPORT_SYMBOL(p9_client_rename);
1980 
1981 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1982 		       struct p9_fid *newdirfid, const char *new_name)
1983 {
1984 	int err;
1985 	struct p9_req_t *req;
1986 	struct p9_client *clnt;
1987 
1988 	err = 0;
1989 	clnt = olddirfid->clnt;
1990 
1991 	p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1992 		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1993 		   newdirfid->fid, new_name);
1994 
1995 	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1996 			    old_name, newdirfid->fid, new_name);
1997 	if (IS_ERR(req)) {
1998 		err = PTR_ERR(req);
1999 		goto error;
2000 	}
2001 
2002 	p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
2003 		   newdirfid->fid, new_name);
2004 
2005 	p9_tag_remove(clnt, req);
2006 error:
2007 	return err;
2008 }
2009 EXPORT_SYMBOL(p9_client_renameat);
2010 
2011 /*
2012  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2013  */
2014 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2015 				const char *attr_name, u64 *attr_size)
2016 {
2017 	int err;
2018 	struct p9_req_t *req;
2019 	struct p9_client *clnt;
2020 	struct p9_fid *attr_fid;
2021 
2022 	err = 0;
2023 	clnt = file_fid->clnt;
2024 	attr_fid = p9_fid_create(clnt);
2025 	if (!attr_fid) {
2026 		err = -ENOMEM;
2027 		goto error;
2028 	}
2029 	p9_debug(P9_DEBUG_9P,
2030 		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2031 		file_fid->fid, attr_fid->fid, attr_name);
2032 
2033 	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2034 			file_fid->fid, attr_fid->fid, attr_name);
2035 	if (IS_ERR(req)) {
2036 		err = PTR_ERR(req);
2037 		goto error;
2038 	}
2039 	err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
2040 	if (err) {
2041 		trace_9p_protocol_dump(clnt, &req->rc);
2042 		p9_tag_remove(clnt, req);
2043 		goto clunk_fid;
2044 	}
2045 	p9_tag_remove(clnt, req);
2046 	p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2047 		attr_fid->fid, *attr_size);
2048 	return attr_fid;
2049 clunk_fid:
2050 	p9_client_clunk(attr_fid);
2051 	attr_fid = NULL;
2052 error:
2053 	if (attr_fid && (attr_fid != file_fid))
2054 		p9_fid_destroy(attr_fid);
2055 
2056 	return ERR_PTR(err);
2057 }
2058 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2059 
2060 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2061 			u64 attr_size, int flags)
2062 {
2063 	int err;
2064 	struct p9_req_t *req;
2065 	struct p9_client *clnt;
2066 
2067 	p9_debug(P9_DEBUG_9P,
2068 		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2069 		fid->fid, name, (long long)attr_size, flags);
2070 	err = 0;
2071 	clnt = fid->clnt;
2072 	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2073 			fid->fid, name, attr_size, flags);
2074 	if (IS_ERR(req)) {
2075 		err = PTR_ERR(req);
2076 		goto error;
2077 	}
2078 	p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2079 	p9_tag_remove(clnt, req);
2080 error:
2081 	return err;
2082 }
2083 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2084 
2085 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2086 {
2087 	int err, rsize, non_zc = 0;
2088 	struct p9_client *clnt;
2089 	struct p9_req_t *req;
2090 	char *dataptr;
2091 	struct kvec kv = {.iov_base = data, .iov_len = count};
2092 	struct iov_iter to;
2093 
2094 	iov_iter_kvec(&to, READ, &kv, 1, count);
2095 
2096 	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2097 				fid->fid, (unsigned long long) offset, count);
2098 
2099 	err = 0;
2100 	clnt = fid->clnt;
2101 
2102 	rsize = fid->iounit;
2103 	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2104 		rsize = clnt->msize - P9_READDIRHDRSZ;
2105 
2106 	if (count < rsize)
2107 		rsize = count;
2108 
2109 	/* Don't bother zerocopy for small IO (< 1024) */
2110 	if (clnt->trans_mod->zc_request && rsize > 1024) {
2111 		/*
2112 		 * response header len is 11
2113 		 * PDU Header(7) + IO Size (4)
2114 		 */
2115 		req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2116 				       11, "dqd", fid->fid, offset, rsize);
2117 	} else {
2118 		non_zc = 1;
2119 		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2120 				    offset, rsize);
2121 	}
2122 	if (IS_ERR(req)) {
2123 		err = PTR_ERR(req);
2124 		goto error;
2125 	}
2126 
2127 	err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
2128 	if (err) {
2129 		trace_9p_protocol_dump(clnt, &req->rc);
2130 		goto free_and_error;
2131 	}
2132 	if (rsize < count) {
2133 		pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2134 		count = rsize;
2135 	}
2136 
2137 	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2138 
2139 	if (non_zc)
2140 		memmove(data, dataptr, count);
2141 
2142 	p9_tag_remove(clnt, req);
2143 	return count;
2144 
2145 free_and_error:
2146 	p9_tag_remove(clnt, req);
2147 error:
2148 	return err;
2149 }
2150 EXPORT_SYMBOL(p9_client_readdir);
2151 
2152 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2153 			dev_t rdev, kgid_t gid, struct p9_qid *qid)
2154 {
2155 	int err;
2156 	struct p9_client *clnt;
2157 	struct p9_req_t *req;
2158 
2159 	err = 0;
2160 	clnt = fid->clnt;
2161 	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2162 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2163 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2164 		MAJOR(rdev), MINOR(rdev), gid);
2165 	if (IS_ERR(req))
2166 		return PTR_ERR(req);
2167 
2168 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2169 	if (err) {
2170 		trace_9p_protocol_dump(clnt, &req->rc);
2171 		goto error;
2172 	}
2173 	p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2174 				(unsigned long long)qid->path, qid->version);
2175 
2176 error:
2177 	p9_tag_remove(clnt, req);
2178 	return err;
2179 
2180 }
2181 EXPORT_SYMBOL(p9_client_mknod_dotl);
2182 
2183 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2184 				kgid_t gid, struct p9_qid *qid)
2185 {
2186 	int err;
2187 	struct p9_client *clnt;
2188 	struct p9_req_t *req;
2189 
2190 	err = 0;
2191 	clnt = fid->clnt;
2192 	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2193 		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2194 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2195 		gid);
2196 	if (IS_ERR(req))
2197 		return PTR_ERR(req);
2198 
2199 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2200 	if (err) {
2201 		trace_9p_protocol_dump(clnt, &req->rc);
2202 		goto error;
2203 	}
2204 	p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2205 				(unsigned long long)qid->path, qid->version);
2206 
2207 error:
2208 	p9_tag_remove(clnt, req);
2209 	return err;
2210 
2211 }
2212 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2213 
2214 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2215 {
2216 	int err;
2217 	struct p9_client *clnt;
2218 	struct p9_req_t *req;
2219 
2220 	err = 0;
2221 	clnt = fid->clnt;
2222 	p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2223 			"start %lld length %lld proc_id %d client_id %s\n",
2224 			fid->fid, flock->type, flock->flags, flock->start,
2225 			flock->length, flock->proc_id, flock->client_id);
2226 
2227 	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2228 				flock->flags, flock->start, flock->length,
2229 					flock->proc_id, flock->client_id);
2230 
2231 	if (IS_ERR(req))
2232 		return PTR_ERR(req);
2233 
2234 	err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
2235 	if (err) {
2236 		trace_9p_protocol_dump(clnt, &req->rc);
2237 		goto error;
2238 	}
2239 	p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2240 error:
2241 	p9_tag_remove(clnt, req);
2242 	return err;
2243 
2244 }
2245 EXPORT_SYMBOL(p9_client_lock_dotl);
2246 
2247 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2248 {
2249 	int err;
2250 	struct p9_client *clnt;
2251 	struct p9_req_t *req;
2252 
2253 	err = 0;
2254 	clnt = fid->clnt;
2255 	p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2256 		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2257 		glock->start, glock->length, glock->proc_id, glock->client_id);
2258 
2259 	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2260 		glock->start, glock->length, glock->proc_id, glock->client_id);
2261 
2262 	if (IS_ERR(req))
2263 		return PTR_ERR(req);
2264 
2265 	err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type,
2266 			  &glock->start, &glock->length, &glock->proc_id,
2267 			  &glock->client_id);
2268 	if (err) {
2269 		trace_9p_protocol_dump(clnt, &req->rc);
2270 		goto error;
2271 	}
2272 	p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2273 		"proc_id %d client_id %s\n", glock->type, glock->start,
2274 		glock->length, glock->proc_id, glock->client_id);
2275 error:
2276 	p9_tag_remove(clnt, req);
2277 	return err;
2278 }
2279 EXPORT_SYMBOL(p9_client_getlock_dotl);
2280 
2281 int p9_client_readlink(struct p9_fid *fid, char **target)
2282 {
2283 	int err;
2284 	struct p9_client *clnt;
2285 	struct p9_req_t *req;
2286 
2287 	err = 0;
2288 	clnt = fid->clnt;
2289 	p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2290 
2291 	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2292 	if (IS_ERR(req))
2293 		return PTR_ERR(req);
2294 
2295 	err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
2296 	if (err) {
2297 		trace_9p_protocol_dump(clnt, &req->rc);
2298 		goto error;
2299 	}
2300 	p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2301 error:
2302 	p9_tag_remove(clnt, req);
2303 	return err;
2304 }
2305 EXPORT_SYMBOL(p9_client_readlink);
2306 
2307 int __init p9_client_init(void)
2308 {
2309 	p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU);
2310 	return p9_req_cache ? 0 : -ENOMEM;
2311 }
2312 
2313 void __exit p9_client_exit(void)
2314 {
2315 	kmem_cache_destroy(p9_req_cache);
2316 }
2317