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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 /*
34   * Client Option Parsing (code inspired by NFS code)
35   *  - a little lazy - parse all client options
36   */
37 
38 enum {
39 	Opt_msize,
40 	Opt_trans,
41 	Opt_legacy,
42 	Opt_version,
43 	Opt_err,
44 };
45 
46 static const match_table_t tokens = {
47 	{Opt_msize, "msize=%u"},
48 	{Opt_legacy, "noextend"},
49 	{Opt_trans, "trans=%s"},
50 	{Opt_version, "version=%s"},
51 	{Opt_err, NULL},
52 };
53 
p9_is_proto_dotl(struct p9_client * clnt)54 inline int p9_is_proto_dotl(struct p9_client *clnt)
55 {
56 	return clnt->proto_version == p9_proto_2000L;
57 }
58 EXPORT_SYMBOL(p9_is_proto_dotl);
59 
p9_is_proto_dotu(struct p9_client * clnt)60 inline int p9_is_proto_dotu(struct p9_client *clnt)
61 {
62 	return clnt->proto_version == p9_proto_2000u;
63 }
64 EXPORT_SYMBOL(p9_is_proto_dotu);
65 
p9_show_client_options(struct seq_file * m,struct p9_client * clnt)66 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
67 {
68 	if (clnt->msize != 8192)
69 		seq_printf(m, ",msize=%u", clnt->msize);
70 	seq_printf(m, ",trans=%s", clnt->trans_mod->name);
71 
72 	switch (clnt->proto_version) {
73 	case p9_proto_legacy:
74 		seq_puts(m, ",noextend");
75 		break;
76 	case p9_proto_2000u:
77 		seq_puts(m, ",version=9p2000.u");
78 		break;
79 	case p9_proto_2000L:
80 		/* Default */
81 		break;
82 	}
83 
84 	if (clnt->trans_mod->show_options)
85 		return clnt->trans_mod->show_options(m, clnt);
86 	return 0;
87 }
88 EXPORT_SYMBOL(p9_show_client_options);
89 
90 /*
91  * Some error codes are taken directly from the server replies,
92  * make sure they are valid.
93  */
safe_errno(int err)94 static int safe_errno(int err)
95 {
96 	if ((err > 0) || (err < -MAX_ERRNO)) {
97 		p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
98 		return -EPROTO;
99 	}
100 	return err;
101 }
102 
103 
104 /* Interpret mount option for protocol version */
get_protocol_version(char * s)105 static int get_protocol_version(char *s)
106 {
107 	int version = -EINVAL;
108 
109 	if (!strcmp(s, "9p2000")) {
110 		version = p9_proto_legacy;
111 		p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
112 	} else if (!strcmp(s, "9p2000.u")) {
113 		version = p9_proto_2000u;
114 		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
115 	} else if (!strcmp(s, "9p2000.L")) {
116 		version = p9_proto_2000L;
117 		p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
118 	} else
119 		pr_info("Unknown protocol version %s\n", s);
120 
121 	return version;
122 }
123 
124 /**
125  * parse_options - parse mount options into client structure
126  * @opts: options string passed from mount
127  * @clnt: existing v9fs client information
128  *
129  * Return 0 upon success, -ERRNO upon failure
130  */
131 
parse_opts(char * opts,struct p9_client * clnt)132 static int parse_opts(char *opts, struct p9_client *clnt)
133 {
134 	char *options, *tmp_options;
135 	char *p;
136 	substring_t args[MAX_OPT_ARGS];
137 	int option;
138 	char *s;
139 	int ret = 0;
140 
141 	clnt->proto_version = p9_proto_2000L;
142 	clnt->msize = 8192;
143 
144 	if (!opts)
145 		return 0;
146 
147 	tmp_options = kstrdup(opts, GFP_KERNEL);
148 	if (!tmp_options) {
149 		p9_debug(P9_DEBUG_ERROR,
150 			 "failed to allocate copy of option string\n");
151 		return -ENOMEM;
152 	}
153 	options = tmp_options;
154 
155 	while ((p = strsep(&options, ",")) != NULL) {
156 		int token, r;
157 		if (!*p)
158 			continue;
159 		token = match_token(p, tokens, args);
160 		switch (token) {
161 		case Opt_msize:
162 			r = match_int(&args[0], &option);
163 			if (r < 0) {
164 				p9_debug(P9_DEBUG_ERROR,
165 					 "integer field, but no integer?\n");
166 				ret = r;
167 				continue;
168 			}
169 			if (option < 4096) {
170 				p9_debug(P9_DEBUG_ERROR,
171 					 "msize should be at least 4k\n");
172 				ret = -EINVAL;
173 				continue;
174 			}
175 			clnt->msize = option;
176 			break;
177 		case Opt_trans:
178 			s = match_strdup(&args[0]);
179 			if (!s) {
180 				ret = -ENOMEM;
181 				p9_debug(P9_DEBUG_ERROR,
182 					 "problem allocating copy of trans arg\n");
183 				goto free_and_return;
184 			}
185 
186 			v9fs_put_trans(clnt->trans_mod);
187 			clnt->trans_mod = v9fs_get_trans_by_name(s);
188 			if (clnt->trans_mod == NULL) {
189 				pr_info("Could not find request transport: %s\n",
190 					s);
191 				ret = -EINVAL;
192 			}
193 			kfree(s);
194 			break;
195 		case Opt_legacy:
196 			clnt->proto_version = p9_proto_legacy;
197 			break;
198 		case Opt_version:
199 			s = match_strdup(&args[0]);
200 			if (!s) {
201 				ret = -ENOMEM;
202 				p9_debug(P9_DEBUG_ERROR,
203 					 "problem allocating copy of version arg\n");
204 				goto free_and_return;
205 			}
206 			r = get_protocol_version(s);
207 			if (r < 0)
208 				ret = r;
209 			else
210 				clnt->proto_version = r;
211 			kfree(s);
212 			break;
213 		default:
214 			continue;
215 		}
216 	}
217 
218 free_and_return:
219 	if (ret)
220 		v9fs_put_trans(clnt->trans_mod);
221 	kfree(tmp_options);
222 	return ret;
223 }
224 
p9_fcall_init(struct p9_client * c,struct p9_fcall * fc,int alloc_msize)225 static int p9_fcall_init(struct p9_client *c, struct p9_fcall *fc,
226 			 int alloc_msize)
227 {
228 	if (likely(c->fcall_cache) && alloc_msize == c->msize) {
229 		fc->sdata = kmem_cache_alloc(c->fcall_cache, GFP_NOFS);
230 		fc->cache = c->fcall_cache;
231 	} else {
232 		fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
233 		fc->cache = NULL;
234 	}
235 	if (!fc->sdata)
236 		return -ENOMEM;
237 	fc->capacity = alloc_msize;
238 	return 0;
239 }
240 
p9_fcall_fini(struct p9_fcall * fc)241 void p9_fcall_fini(struct p9_fcall *fc)
242 {
243 	/* sdata can be NULL for interrupted requests in trans_rdma,
244 	 * and kmem_cache_free does not do NULL-check for us
245 	 */
246 	if (unlikely(!fc->sdata))
247 		return;
248 
249 	if (fc->cache)
250 		kmem_cache_free(fc->cache, fc->sdata);
251 	else
252 		kfree(fc->sdata);
253 }
254 EXPORT_SYMBOL(p9_fcall_fini);
255 
256 static struct kmem_cache *p9_req_cache;
257 
258 /**
259  * p9_req_alloc - Allocate a new request.
260  * @c: Client session.
261  * @type: Transaction type.
262  * @max_size: Maximum packet size for this request.
263  *
264  * Context: Process context.
265  * Return: Pointer to new request.
266  */
267 static struct p9_req_t *
p9_tag_alloc(struct p9_client * c,int8_t type,unsigned int max_size)268 p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
269 {
270 	struct p9_req_t *req = kmem_cache_alloc(p9_req_cache, GFP_NOFS);
271 	int alloc_msize = min(c->msize, max_size);
272 	int tag;
273 
274 	if (!req)
275 		return ERR_PTR(-ENOMEM);
276 
277 	if (p9_fcall_init(c, &req->tc, alloc_msize))
278 		goto free_req;
279 	if (p9_fcall_init(c, &req->rc, alloc_msize))
280 		goto free;
281 
282 	p9pdu_reset(&req->tc);
283 	p9pdu_reset(&req->rc);
284 	req->t_err = 0;
285 	req->status = REQ_STATUS_ALLOC;
286 	init_waitqueue_head(&req->wq);
287 	INIT_LIST_HEAD(&req->req_list);
288 
289 	idr_preload(GFP_NOFS);
290 	spin_lock_irq(&c->lock);
291 	if (type == P9_TVERSION)
292 		tag = idr_alloc(&c->reqs, req, P9_NOTAG, P9_NOTAG + 1,
293 				GFP_NOWAIT);
294 	else
295 		tag = idr_alloc(&c->reqs, req, 0, P9_NOTAG, GFP_NOWAIT);
296 	req->tc.tag = tag;
297 	spin_unlock_irq(&c->lock);
298 	idr_preload_end();
299 	if (tag < 0)
300 		goto free;
301 
302 	/* Init ref to two because in the general case there is one ref
303 	 * that is put asynchronously by a writer thread, one ref
304 	 * temporarily given by p9_tag_lookup and put by p9_client_cb
305 	 * in the recv thread, and one ref put by p9_tag_remove in the
306 	 * main thread. The only exception is virtio that does not use
307 	 * p9_tag_lookup but does not have a writer thread either
308 	 * (the write happens synchronously in the request/zc_request
309 	 * callback), so p9_client_cb eats the second ref there
310 	 * as the pointer is duplicated directly by virtqueue_add_sgs()
311 	 */
312 	refcount_set(&req->refcount.refcount, 2);
313 
314 	return req;
315 
316 free:
317 	p9_fcall_fini(&req->tc);
318 	p9_fcall_fini(&req->rc);
319 free_req:
320 	kmem_cache_free(p9_req_cache, req);
321 	return ERR_PTR(-ENOMEM);
322 }
323 
324 /**
325  * p9_tag_lookup - Look up a request by tag.
326  * @c: Client session.
327  * @tag: Transaction ID.
328  *
329  * Context: Any context.
330  * Return: A request, or %NULL if there is no request with that tag.
331  */
p9_tag_lookup(struct p9_client * c,u16 tag)332 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
333 {
334 	struct p9_req_t *req;
335 
336 	rcu_read_lock();
337 again:
338 	req = idr_find(&c->reqs, tag);
339 	if (req) {
340 		/* We have to be careful with the req found under rcu_read_lock
341 		 * Thanks to SLAB_TYPESAFE_BY_RCU we can safely try to get the
342 		 * ref again without corrupting other data, then check again
343 		 * that the tag matches once we have the ref
344 		 */
345 		if (!p9_req_try_get(req))
346 			goto again;
347 		if (req->tc.tag != tag) {
348 			p9_req_put(req);
349 			goto again;
350 		}
351 	}
352 	rcu_read_unlock();
353 
354 	return req;
355 }
356 EXPORT_SYMBOL(p9_tag_lookup);
357 
358 /**
359  * p9_tag_remove - Remove a tag.
360  * @c: Client session.
361  * @r: Request of reference.
362  *
363  * Context: Any context.
364  */
p9_tag_remove(struct p9_client * c,struct p9_req_t * r)365 static int p9_tag_remove(struct p9_client *c, struct p9_req_t *r)
366 {
367 	unsigned long flags;
368 	u16 tag = r->tc.tag;
369 
370 	p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
371 	spin_lock_irqsave(&c->lock, flags);
372 	idr_remove(&c->reqs, tag);
373 	spin_unlock_irqrestore(&c->lock, flags);
374 	return p9_req_put(r);
375 }
376 
p9_req_free(struct kref * ref)377 static void p9_req_free(struct kref *ref)
378 {
379 	struct p9_req_t *r = container_of(ref, struct p9_req_t, refcount);
380 	p9_fcall_fini(&r->tc);
381 	p9_fcall_fini(&r->rc);
382 	kmem_cache_free(p9_req_cache, r);
383 }
384 
p9_req_put(struct p9_req_t * r)385 int p9_req_put(struct p9_req_t *r)
386 {
387 	return kref_put(&r->refcount, p9_req_free);
388 }
389 EXPORT_SYMBOL(p9_req_put);
390 
391 /**
392  * p9_tag_cleanup - cleans up tags structure and reclaims resources
393  * @c:  v9fs client struct
394  *
395  * This frees resources associated with the tags structure
396  *
397  */
p9_tag_cleanup(struct p9_client * c)398 static void p9_tag_cleanup(struct p9_client *c)
399 {
400 	struct p9_req_t *req;
401 	int id;
402 
403 	rcu_read_lock();
404 	idr_for_each_entry(&c->reqs, req, id) {
405 		pr_info("Tag %d still in use\n", id);
406 		if (p9_tag_remove(c, req) == 0)
407 			pr_warn("Packet with tag %d has still references",
408 				req->tc.tag);
409 	}
410 	rcu_read_unlock();
411 }
412 
413 /**
414  * p9_client_cb - call back from transport to client
415  * c: client state
416  * req: request received
417  *
418  */
p9_client_cb(struct p9_client * c,struct p9_req_t * req,int status)419 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
420 {
421 	p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc.tag);
422 
423 	/*
424 	 * This barrier is needed to make sure any change made to req before
425 	 * the status change is visible to another thread
426 	 */
427 	smp_wmb();
428 	req->status = status;
429 
430 	wake_up(&req->wq);
431 	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc.tag);
432 	p9_req_put(req);
433 }
434 EXPORT_SYMBOL(p9_client_cb);
435 
436 /**
437  * p9_parse_header - parse header arguments out of a packet
438  * @pdu: packet to parse
439  * @size: size of packet
440  * @type: type of request
441  * @tag: tag of packet
442  * @rewind: set if we need to rewind offset afterwards
443  */
444 
445 int
p9_parse_header(struct p9_fcall * pdu,int32_t * size,int8_t * type,int16_t * tag,int rewind)446 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
447 								int rewind)
448 {
449 	int8_t r_type;
450 	int16_t r_tag;
451 	int32_t r_size;
452 	int offset = pdu->offset;
453 	int err;
454 
455 	pdu->offset = 0;
456 
457 	err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
458 	if (err)
459 		goto rewind_and_exit;
460 
461 	if (type)
462 		*type = r_type;
463 	if (tag)
464 		*tag = r_tag;
465 	if (size)
466 		*size = r_size;
467 
468 	if (pdu->size != r_size || r_size < 7) {
469 		err = -EINVAL;
470 		goto rewind_and_exit;
471 	}
472 
473 	pdu->id = r_type;
474 	pdu->tag = r_tag;
475 
476 	p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
477 		 pdu->size, pdu->id, pdu->tag);
478 
479 rewind_and_exit:
480 	if (rewind)
481 		pdu->offset = offset;
482 	return err;
483 }
484 EXPORT_SYMBOL(p9_parse_header);
485 
486 /**
487  * p9_check_errors - check 9p packet for error return and process it
488  * @c: current client instance
489  * @req: request to parse and check for error conditions
490  *
491  * returns error code if one is discovered, otherwise returns 0
492  *
493  * this will have to be more complicated if we have multiple
494  * error packet types
495  */
496 
p9_check_errors(struct p9_client * c,struct p9_req_t * req)497 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
498 {
499 	int8_t type;
500 	int err;
501 	int ecode;
502 
503 	err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
504 	if (req->rc.size >= c->msize) {
505 		p9_debug(P9_DEBUG_ERROR,
506 			 "requested packet size too big: %d\n",
507 			 req->rc.size);
508 		return -EIO;
509 	}
510 	/*
511 	 * dump the response from server
512 	 * This should be after check errors which poplulate pdu_fcall.
513 	 */
514 	trace_9p_protocol_dump(c, &req->rc);
515 	if (err) {
516 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
517 		return err;
518 	}
519 	if (type != P9_RERROR && type != P9_RLERROR)
520 		return 0;
521 
522 	if (!p9_is_proto_dotl(c)) {
523 		char *ename = NULL;
524 
525 		err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
526 				  &ename, &ecode);
527 		if (err) {
528 			kfree(ename);
529 			goto out_err;
530 		}
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  * @in_hdrlen: Size of response protocol buffer.
564  *
565  * returns error code if one is discovered, otherwise returns 0
566  *
567  * this will have to be more complicated if we have multiple
568  * error packet types
569  */
570 
p9_check_zc_errors(struct p9_client * c,struct p9_req_t * req,struct iov_iter * uidata,int in_hdrlen)571 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
572 			      struct iov_iter *uidata, int in_hdrlen)
573 {
574 	int err;
575 	int ecode;
576 	int8_t type;
577 	char *ename = NULL;
578 
579 	err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
580 	/*
581 	 * dump the response from server
582 	 * This should be after parse_header which poplulate pdu_fcall.
583 	 */
584 	trace_9p_protocol_dump(c, &req->rc);
585 	if (err) {
586 		p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
587 		return err;
588 	}
589 
590 	if (type != P9_RERROR && type != P9_RLERROR)
591 		return 0;
592 
593 	if (!p9_is_proto_dotl(c)) {
594 		/* Error is reported in string format */
595 		int len;
596 		/* 7 = header size for RERROR; */
597 		int inline_len = in_hdrlen - 7;
598 
599 		len = req->rc.size - req->rc.offset;
600 		if (len > (P9_ZC_HDR_SZ - 7)) {
601 			err = -EFAULT;
602 			goto out_err;
603 		}
604 
605 		ename = &req->rc.sdata[req->rc.offset];
606 		if (len > inline_len) {
607 			/* We have error in external buffer */
608 			if (!copy_from_iter_full(ename + inline_len,
609 					     len - inline_len, uidata)) {
610 				err = -EFAULT;
611 				goto out_err;
612 			}
613 		}
614 		ename = NULL;
615 		err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
616 				  &ename, &ecode);
617 		if (err)
618 			goto out_err;
619 
620 		if (p9_is_proto_dotu(c) && ecode < 512)
621 			err = -ecode;
622 
623 		if (!err) {
624 			err = p9_errstr2errno(ename, strlen(ename));
625 
626 			p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
627 				 -ecode, ename);
628 		}
629 		kfree(ename);
630 	} else {
631 		err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
632 		err = -ecode;
633 
634 		p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
635 	}
636 	return err;
637 
638 out_err:
639 	p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
640 	return err;
641 }
642 
643 static struct p9_req_t *
644 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
645 
646 /**
647  * p9_client_flush - flush (cancel) a request
648  * @c: client state
649  * @oldreq: request to cancel
650  *
651  * This sents a flush for a particular request and links
652  * the flush request to the original request.  The current
653  * code only supports a single flush request although the protocol
654  * allows for multiple flush requests to be sent for a single request.
655  *
656  */
657 
p9_client_flush(struct p9_client * c,struct p9_req_t * oldreq)658 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
659 {
660 	struct p9_req_t *req;
661 	int16_t oldtag;
662 	int err;
663 
664 	err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
665 	if (err)
666 		return err;
667 
668 	p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
669 
670 	req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
671 	if (IS_ERR(req))
672 		return PTR_ERR(req);
673 
674 	/*
675 	 * if we haven't received a response for oldreq,
676 	 * remove it from the list
677 	 */
678 	if (oldreq->status == REQ_STATUS_SENT) {
679 		if (c->trans_mod->cancelled)
680 			c->trans_mod->cancelled(c, oldreq);
681 	}
682 
683 	p9_tag_remove(c, req);
684 	return 0;
685 }
686 
p9_client_prepare_req(struct p9_client * c,int8_t type,int req_size,const char * fmt,va_list ap)687 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
688 					      int8_t type, int req_size,
689 					      const char *fmt, va_list ap)
690 {
691 	int err;
692 	struct p9_req_t *req;
693 
694 	p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
695 
696 	/* we allow for any status other than disconnected */
697 	if (c->status == Disconnected)
698 		return ERR_PTR(-EIO);
699 
700 	/* if status is begin_disconnected we allow only clunk request */
701 	if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
702 		return ERR_PTR(-EIO);
703 
704 	req = p9_tag_alloc(c, type, req_size);
705 	if (IS_ERR(req))
706 		return req;
707 
708 	/* marshall the data */
709 	p9pdu_prepare(&req->tc, req->tc.tag, type);
710 	err = p9pdu_vwritef(&req->tc, c->proto_version, fmt, ap);
711 	if (err)
712 		goto reterr;
713 	p9pdu_finalize(c, &req->tc);
714 	trace_9p_client_req(c, type, req->tc.tag);
715 	return req;
716 reterr:
717 	p9_tag_remove(c, req);
718 	/* We have to put also the 2nd reference as it won't be used */
719 	p9_req_put(req);
720 	return ERR_PTR(err);
721 }
722 
723 /**
724  * p9_client_rpc - issue a request and wait for a response
725  * @c: client session
726  * @type: type of request
727  * @fmt: protocol format string (see protocol.c)
728  *
729  * Returns request structure (which client must free using p9_tag_remove)
730  */
731 
732 static struct p9_req_t *
p9_client_rpc(struct p9_client * c,int8_t type,const char * fmt,...)733 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
734 {
735 	va_list ap;
736 	int sigpending, err;
737 	unsigned long flags;
738 	struct p9_req_t *req;
739 
740 	va_start(ap, fmt);
741 	req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
742 	va_end(ap);
743 	if (IS_ERR(req))
744 		return req;
745 
746 	if (signal_pending(current)) {
747 		sigpending = 1;
748 		clear_thread_flag(TIF_SIGPENDING);
749 	} else
750 		sigpending = 0;
751 
752 	err = c->trans_mod->request(c, req);
753 	if (err < 0) {
754 		/* write won't happen */
755 		p9_req_put(req);
756 		if (err != -ERESTARTSYS && err != -EFAULT)
757 			c->status = Disconnected;
758 		goto recalc_sigpending;
759 	}
760 again:
761 	/* Wait for the response */
762 	err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
763 
764 	/*
765 	 * Make sure our req is coherent with regard to updates in other
766 	 * threads - echoes to wmb() in the callback
767 	 */
768 	smp_rmb();
769 
770 	if ((err == -ERESTARTSYS) && (c->status == Connected)
771 				  && (type == P9_TFLUSH)) {
772 		sigpending = 1;
773 		clear_thread_flag(TIF_SIGPENDING);
774 		goto again;
775 	}
776 
777 	if (req->status == REQ_STATUS_ERROR) {
778 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
779 		err = req->t_err;
780 	}
781 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
782 		p9_debug(P9_DEBUG_MUX, "flushing\n");
783 		sigpending = 1;
784 		clear_thread_flag(TIF_SIGPENDING);
785 
786 		if (c->trans_mod->cancel(c, req))
787 			p9_client_flush(c, req);
788 
789 		/* if we received the response anyway, don't signal error */
790 		if (req->status == REQ_STATUS_RCVD)
791 			err = 0;
792 	}
793 recalc_sigpending:
794 	if (sigpending) {
795 		spin_lock_irqsave(&current->sighand->siglock, flags);
796 		recalc_sigpending();
797 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
798 	}
799 	if (err < 0)
800 		goto reterr;
801 
802 	err = p9_check_errors(c, req);
803 	trace_9p_client_res(c, type, req->rc.tag, err);
804 	if (!err)
805 		return req;
806 reterr:
807 	p9_tag_remove(c, req);
808 	return ERR_PTR(safe_errno(err));
809 }
810 
811 /**
812  * p9_client_zc_rpc - issue a request and wait for a response
813  * @c: client session
814  * @type: type of request
815  * @uidata: destination for zero copy read
816  * @uodata: source for zero copy write
817  * @inlen: read buffer size
818  * @olen: write buffer size
819  * @in_hdrlen: reader header size, This is the size of response protocol data
820  * @fmt: protocol format string (see protocol.c)
821  *
822  * Returns request structure (which client must free using p9_tag_remove)
823  */
p9_client_zc_rpc(struct p9_client * c,int8_t type,struct iov_iter * uidata,struct iov_iter * uodata,int inlen,int olen,int in_hdrlen,const char * fmt,...)824 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
825 					 struct iov_iter *uidata,
826 					 struct iov_iter *uodata,
827 					 int inlen, int olen, int in_hdrlen,
828 					 const char *fmt, ...)
829 {
830 	va_list ap;
831 	int sigpending, err;
832 	unsigned long flags;
833 	struct p9_req_t *req;
834 
835 	va_start(ap, fmt);
836 	/*
837 	 * We allocate a inline protocol data of only 4k bytes.
838 	 * The actual content is passed in zero-copy fashion.
839 	 */
840 	req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
841 	va_end(ap);
842 	if (IS_ERR(req))
843 		return req;
844 
845 	if (signal_pending(current)) {
846 		sigpending = 1;
847 		clear_thread_flag(TIF_SIGPENDING);
848 	} else
849 		sigpending = 0;
850 
851 	err = c->trans_mod->zc_request(c, req, uidata, uodata,
852 				       inlen, olen, in_hdrlen);
853 	if (err < 0) {
854 		if (err == -EIO)
855 			c->status = Disconnected;
856 		if (err != -ERESTARTSYS)
857 			goto recalc_sigpending;
858 	}
859 	if (req->status == REQ_STATUS_ERROR) {
860 		p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
861 		err = req->t_err;
862 	}
863 	if ((err == -ERESTARTSYS) && (c->status == Connected)) {
864 		p9_debug(P9_DEBUG_MUX, "flushing\n");
865 		sigpending = 1;
866 		clear_thread_flag(TIF_SIGPENDING);
867 
868 		if (c->trans_mod->cancel(c, req))
869 			p9_client_flush(c, req);
870 
871 		/* if we received the response anyway, don't signal error */
872 		if (req->status == REQ_STATUS_RCVD)
873 			err = 0;
874 	}
875 recalc_sigpending:
876 	if (sigpending) {
877 		spin_lock_irqsave(&current->sighand->siglock, flags);
878 		recalc_sigpending();
879 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
880 	}
881 	if (err < 0)
882 		goto reterr;
883 
884 	err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
885 	trace_9p_client_res(c, type, req->rc.tag, err);
886 	if (!err)
887 		return req;
888 reterr:
889 	p9_tag_remove(c, req);
890 	return ERR_PTR(safe_errno(err));
891 }
892 
p9_fid_create(struct p9_client * clnt)893 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
894 {
895 	int ret;
896 	struct p9_fid *fid;
897 
898 	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
899 	fid = kzalloc(sizeof(struct p9_fid), GFP_KERNEL);
900 	if (!fid)
901 		return NULL;
902 
903 	fid->mode = -1;
904 	fid->uid = current_fsuid();
905 	fid->clnt = clnt;
906 
907 	idr_preload(GFP_KERNEL);
908 	spin_lock_irq(&clnt->lock);
909 	ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
910 			    GFP_NOWAIT);
911 	spin_unlock_irq(&clnt->lock);
912 	idr_preload_end();
913 
914 	if (!ret)
915 		return fid;
916 
917 	kfree(fid);
918 	return NULL;
919 }
920 
p9_fid_destroy(struct p9_fid * fid)921 static void p9_fid_destroy(struct p9_fid *fid)
922 {
923 	struct p9_client *clnt;
924 	unsigned long flags;
925 
926 	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
927 	clnt = fid->clnt;
928 	spin_lock_irqsave(&clnt->lock, flags);
929 	idr_remove(&clnt->fids, fid->fid);
930 	spin_unlock_irqrestore(&clnt->lock, flags);
931 	kfree(fid->rdir);
932 	kfree(fid);
933 }
934 
p9_client_version(struct p9_client * c)935 static int p9_client_version(struct p9_client *c)
936 {
937 	int err = 0;
938 	struct p9_req_t *req;
939 	char *version = NULL;
940 	int msize;
941 
942 	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
943 		 c->msize, c->proto_version);
944 
945 	switch (c->proto_version) {
946 	case p9_proto_2000L:
947 		req = p9_client_rpc(c, P9_TVERSION, "ds",
948 					c->msize, "9P2000.L");
949 		break;
950 	case p9_proto_2000u:
951 		req = p9_client_rpc(c, P9_TVERSION, "ds",
952 					c->msize, "9P2000.u");
953 		break;
954 	case p9_proto_legacy:
955 		req = p9_client_rpc(c, P9_TVERSION, "ds",
956 					c->msize, "9P2000");
957 		break;
958 	default:
959 		return -EINVAL;
960 	}
961 
962 	if (IS_ERR(req))
963 		return PTR_ERR(req);
964 
965 	err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version);
966 	if (err) {
967 		p9_debug(P9_DEBUG_9P, "version error %d\n", err);
968 		trace_9p_protocol_dump(c, &req->rc);
969 		goto error;
970 	}
971 
972 	p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
973 	if (!strncmp(version, "9P2000.L", 8))
974 		c->proto_version = p9_proto_2000L;
975 	else if (!strncmp(version, "9P2000.u", 8))
976 		c->proto_version = p9_proto_2000u;
977 	else if (!strncmp(version, "9P2000", 6))
978 		c->proto_version = p9_proto_legacy;
979 	else {
980 		p9_debug(P9_DEBUG_ERROR,
981 			 "server returned an unknown version: %s\n", version);
982 		err = -EREMOTEIO;
983 		goto error;
984 	}
985 
986 	if (msize < 4096) {
987 		p9_debug(P9_DEBUG_ERROR,
988 			 "server returned a msize < 4096: %d\n", msize);
989 		err = -EREMOTEIO;
990 		goto error;
991 	}
992 	if (msize < c->msize)
993 		c->msize = msize;
994 
995 error:
996 	kfree(version);
997 	p9_tag_remove(c, req);
998 
999 	return err;
1000 }
1001 
p9_client_create(const char * dev_name,char * options)1002 struct p9_client *p9_client_create(const char *dev_name, char *options)
1003 {
1004 	int err;
1005 	struct p9_client *clnt;
1006 	char *client_id;
1007 
1008 	err = 0;
1009 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1010 	if (!clnt)
1011 		return ERR_PTR(-ENOMEM);
1012 
1013 	clnt->trans_mod = NULL;
1014 	clnt->trans = NULL;
1015 	clnt->fcall_cache = NULL;
1016 
1017 	client_id = utsname()->nodename;
1018 	memcpy(clnt->name, client_id, strlen(client_id) + 1);
1019 
1020 	spin_lock_init(&clnt->lock);
1021 	idr_init(&clnt->fids);
1022 	idr_init(&clnt->reqs);
1023 
1024 	err = parse_opts(options, clnt);
1025 	if (err < 0)
1026 		goto free_client;
1027 
1028 	if (!clnt->trans_mod)
1029 		clnt->trans_mod = v9fs_get_default_trans();
1030 
1031 	if (clnt->trans_mod == NULL) {
1032 		err = -EPROTONOSUPPORT;
1033 		p9_debug(P9_DEBUG_ERROR,
1034 			 "No transport defined or default transport\n");
1035 		goto free_client;
1036 	}
1037 
1038 	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1039 		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1040 
1041 	err = clnt->trans_mod->create(clnt, dev_name, options);
1042 	if (err)
1043 		goto put_trans;
1044 
1045 	if (clnt->msize > clnt->trans_mod->maxsize)
1046 		clnt->msize = clnt->trans_mod->maxsize;
1047 
1048 	if (clnt->msize < 4096) {
1049 		p9_debug(P9_DEBUG_ERROR,
1050 			 "Please specify a msize of at least 4k\n");
1051 		err = -EINVAL;
1052 		goto close_trans;
1053 	}
1054 
1055 	err = p9_client_version(clnt);
1056 	if (err)
1057 		goto close_trans;
1058 
1059 	/* P9_HDRSZ + 4 is the smallest packet header we can have that is
1060 	 * followed by data accessed from userspace by read
1061 	 */
1062 	clnt->fcall_cache =
1063 		kmem_cache_create_usercopy("9p-fcall-cache", clnt->msize,
1064 					   0, 0, P9_HDRSZ + 4,
1065 					   clnt->msize - (P9_HDRSZ + 4),
1066 					   NULL);
1067 
1068 	return clnt;
1069 
1070 close_trans:
1071 	clnt->trans_mod->close(clnt);
1072 put_trans:
1073 	v9fs_put_trans(clnt->trans_mod);
1074 free_client:
1075 	kfree(clnt);
1076 	return ERR_PTR(err);
1077 }
1078 EXPORT_SYMBOL(p9_client_create);
1079 
p9_client_destroy(struct p9_client * clnt)1080 void p9_client_destroy(struct p9_client *clnt)
1081 {
1082 	struct p9_fid *fid;
1083 	int id;
1084 
1085 	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1086 
1087 	if (clnt->trans_mod)
1088 		clnt->trans_mod->close(clnt);
1089 
1090 	v9fs_put_trans(clnt->trans_mod);
1091 
1092 	idr_for_each_entry(&clnt->fids, fid, id) {
1093 		pr_info("Found fid %d not clunked\n", fid->fid);
1094 		p9_fid_destroy(fid);
1095 	}
1096 
1097 	p9_tag_cleanup(clnt);
1098 
1099 	kmem_cache_destroy(clnt->fcall_cache);
1100 	kfree(clnt);
1101 }
1102 EXPORT_SYMBOL(p9_client_destroy);
1103 
p9_client_disconnect(struct p9_client * clnt)1104 void p9_client_disconnect(struct p9_client *clnt)
1105 {
1106 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1107 	clnt->status = Disconnected;
1108 }
1109 EXPORT_SYMBOL(p9_client_disconnect);
1110 
p9_client_begin_disconnect(struct p9_client * clnt)1111 void p9_client_begin_disconnect(struct p9_client *clnt)
1112 {
1113 	p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1114 	clnt->status = BeginDisconnect;
1115 }
1116 EXPORT_SYMBOL(p9_client_begin_disconnect);
1117 
p9_client_attach(struct p9_client * clnt,struct p9_fid * afid,const char * uname,kuid_t n_uname,const char * aname)1118 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1119 	const char *uname, kuid_t n_uname, const char *aname)
1120 {
1121 	int err = 0;
1122 	struct p9_req_t *req;
1123 	struct p9_fid *fid;
1124 	struct p9_qid qid;
1125 
1126 
1127 	p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1128 		 afid ? afid->fid : -1, uname, aname);
1129 	fid = p9_fid_create(clnt);
1130 	if (!fid) {
1131 		err = -ENOMEM;
1132 		goto error;
1133 	}
1134 	fid->uid = n_uname;
1135 
1136 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1137 			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1138 	if (IS_ERR(req)) {
1139 		err = PTR_ERR(req);
1140 		goto error;
1141 	}
1142 
1143 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
1144 	if (err) {
1145 		trace_9p_protocol_dump(clnt, &req->rc);
1146 		p9_tag_remove(clnt, req);
1147 		goto error;
1148 	}
1149 
1150 	p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1151 		 qid.type, (unsigned long long)qid.path, qid.version);
1152 
1153 	memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1154 
1155 	p9_tag_remove(clnt, req);
1156 	return fid;
1157 
1158 error:
1159 	if (fid)
1160 		p9_fid_destroy(fid);
1161 	return ERR_PTR(err);
1162 }
1163 EXPORT_SYMBOL(p9_client_attach);
1164 
p9_client_walk(struct p9_fid * oldfid,uint16_t nwname,const unsigned char * const * wnames,int clone)1165 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1166 		const unsigned char * const *wnames, int clone)
1167 {
1168 	int err;
1169 	struct p9_client *clnt;
1170 	struct p9_fid *fid;
1171 	struct p9_qid *wqids;
1172 	struct p9_req_t *req;
1173 	uint16_t nwqids, count;
1174 
1175 	err = 0;
1176 	wqids = NULL;
1177 	clnt = oldfid->clnt;
1178 	if (clone) {
1179 		fid = p9_fid_create(clnt);
1180 		if (!fid) {
1181 			err = -ENOMEM;
1182 			goto error;
1183 		}
1184 
1185 		fid->uid = oldfid->uid;
1186 	} else
1187 		fid = oldfid;
1188 
1189 
1190 	p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1191 		 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1192 
1193 	req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1194 								nwname, wnames);
1195 	if (IS_ERR(req)) {
1196 		err = PTR_ERR(req);
1197 		goto error;
1198 	}
1199 
1200 	err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1201 	if (err) {
1202 		trace_9p_protocol_dump(clnt, &req->rc);
1203 		p9_tag_remove(clnt, req);
1204 		goto clunk_fid;
1205 	}
1206 	p9_tag_remove(clnt, req);
1207 
1208 	p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1209 
1210 	if (nwqids != nwname) {
1211 		err = -ENOENT;
1212 		goto clunk_fid;
1213 	}
1214 
1215 	for (count = 0; count < nwqids; count++)
1216 		p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1217 			count, wqids[count].type,
1218 			(unsigned long long)wqids[count].path,
1219 			wqids[count].version);
1220 
1221 	if (nwname)
1222 		memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1223 	else
1224 		fid->qid = oldfid->qid;
1225 
1226 	kfree(wqids);
1227 	return fid;
1228 
1229 clunk_fid:
1230 	kfree(wqids);
1231 	p9_client_clunk(fid);
1232 	fid = NULL;
1233 
1234 error:
1235 	if (fid && (fid != oldfid))
1236 		p9_fid_destroy(fid);
1237 
1238 	return ERR_PTR(err);
1239 }
1240 EXPORT_SYMBOL(p9_client_walk);
1241 
p9_client_open(struct p9_fid * fid,int mode)1242 int p9_client_open(struct p9_fid *fid, int mode)
1243 {
1244 	int err;
1245 	struct p9_client *clnt;
1246 	struct p9_req_t *req;
1247 	struct p9_qid qid;
1248 	int iounit;
1249 
1250 	clnt = fid->clnt;
1251 	p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1252 		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1253 	err = 0;
1254 
1255 	if (fid->mode != -1)
1256 		return -EINVAL;
1257 
1258 	if (p9_is_proto_dotl(clnt))
1259 		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1260 	else
1261 		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1262 	if (IS_ERR(req)) {
1263 		err = PTR_ERR(req);
1264 		goto error;
1265 	}
1266 
1267 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1268 	if (err) {
1269 		trace_9p_protocol_dump(clnt, &req->rc);
1270 		goto free_and_error;
1271 	}
1272 
1273 	p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1274 		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1275 		(unsigned long long)qid.path, qid.version, iounit);
1276 
1277 	fid->mode = mode;
1278 	fid->iounit = iounit;
1279 
1280 free_and_error:
1281 	p9_tag_remove(clnt, req);
1282 error:
1283 	return err;
1284 }
1285 EXPORT_SYMBOL(p9_client_open);
1286 
p9_client_create_dotl(struct p9_fid * ofid,const char * name,u32 flags,u32 mode,kgid_t gid,struct p9_qid * qid)1287 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1288 		kgid_t gid, struct p9_qid *qid)
1289 {
1290 	int err = 0;
1291 	struct p9_client *clnt;
1292 	struct p9_req_t *req;
1293 	int iounit;
1294 
1295 	p9_debug(P9_DEBUG_9P,
1296 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1297 			ofid->fid, name, flags, mode,
1298 		 	from_kgid(&init_user_ns, gid));
1299 	clnt = ofid->clnt;
1300 
1301 	if (ofid->mode != -1)
1302 		return -EINVAL;
1303 
1304 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1305 			mode, gid);
1306 	if (IS_ERR(req)) {
1307 		err = PTR_ERR(req);
1308 		goto error;
1309 	}
1310 
1311 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
1312 	if (err) {
1313 		trace_9p_protocol_dump(clnt, &req->rc);
1314 		goto free_and_error;
1315 	}
1316 
1317 	p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1318 			qid->type,
1319 			(unsigned long long)qid->path,
1320 			qid->version, iounit);
1321 
1322 	ofid->mode = mode;
1323 	ofid->iounit = iounit;
1324 
1325 free_and_error:
1326 	p9_tag_remove(clnt, req);
1327 error:
1328 	return err;
1329 }
1330 EXPORT_SYMBOL(p9_client_create_dotl);
1331 
p9_client_fcreate(struct p9_fid * fid,const char * name,u32 perm,int mode,char * extension)1332 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1333 		     char *extension)
1334 {
1335 	int err;
1336 	struct p9_client *clnt;
1337 	struct p9_req_t *req;
1338 	struct p9_qid qid;
1339 	int iounit;
1340 
1341 	p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1342 						fid->fid, name, perm, mode);
1343 	err = 0;
1344 	clnt = fid->clnt;
1345 
1346 	if (fid->mode != -1)
1347 		return -EINVAL;
1348 
1349 	req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1350 				mode, extension);
1351 	if (IS_ERR(req)) {
1352 		err = PTR_ERR(req);
1353 		goto error;
1354 	}
1355 
1356 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1357 	if (err) {
1358 		trace_9p_protocol_dump(clnt, &req->rc);
1359 		goto free_and_error;
1360 	}
1361 
1362 	p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1363 				qid.type,
1364 				(unsigned long long)qid.path,
1365 				qid.version, iounit);
1366 
1367 	fid->mode = mode;
1368 	fid->iounit = iounit;
1369 
1370 free_and_error:
1371 	p9_tag_remove(clnt, req);
1372 error:
1373 	return err;
1374 }
1375 EXPORT_SYMBOL(p9_client_fcreate);
1376 
p9_client_symlink(struct p9_fid * dfid,const char * name,const char * symtgt,kgid_t gid,struct p9_qid * qid)1377 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1378 		const char *symtgt, kgid_t gid, struct p9_qid *qid)
1379 {
1380 	int err = 0;
1381 	struct p9_client *clnt;
1382 	struct p9_req_t *req;
1383 
1384 	p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1385 			dfid->fid, name, symtgt);
1386 	clnt = dfid->clnt;
1387 
1388 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1389 			gid);
1390 	if (IS_ERR(req)) {
1391 		err = PTR_ERR(req);
1392 		goto error;
1393 	}
1394 
1395 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
1396 	if (err) {
1397 		trace_9p_protocol_dump(clnt, &req->rc);
1398 		goto free_and_error;
1399 	}
1400 
1401 	p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1402 			qid->type, (unsigned long long)qid->path, qid->version);
1403 
1404 free_and_error:
1405 	p9_tag_remove(clnt, req);
1406 error:
1407 	return err;
1408 }
1409 EXPORT_SYMBOL(p9_client_symlink);
1410 
p9_client_link(struct p9_fid * dfid,struct p9_fid * oldfid,const char * newname)1411 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1412 {
1413 	struct p9_client *clnt;
1414 	struct p9_req_t *req;
1415 
1416 	p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1417 			dfid->fid, oldfid->fid, newname);
1418 	clnt = dfid->clnt;
1419 	req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1420 			newname);
1421 	if (IS_ERR(req))
1422 		return PTR_ERR(req);
1423 
1424 	p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1425 	p9_tag_remove(clnt, req);
1426 	return 0;
1427 }
1428 EXPORT_SYMBOL(p9_client_link);
1429 
p9_client_fsync(struct p9_fid * fid,int datasync)1430 int p9_client_fsync(struct p9_fid *fid, int datasync)
1431 {
1432 	int err;
1433 	struct p9_client *clnt;
1434 	struct p9_req_t *req;
1435 
1436 	p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1437 			fid->fid, datasync);
1438 	err = 0;
1439 	clnt = fid->clnt;
1440 
1441 	req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1442 	if (IS_ERR(req)) {
1443 		err = PTR_ERR(req);
1444 		goto error;
1445 	}
1446 
1447 	p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1448 
1449 	p9_tag_remove(clnt, req);
1450 
1451 error:
1452 	return err;
1453 }
1454 EXPORT_SYMBOL(p9_client_fsync);
1455 
p9_client_clunk(struct p9_fid * fid)1456 int p9_client_clunk(struct p9_fid *fid)
1457 {
1458 	int err;
1459 	struct p9_client *clnt;
1460 	struct p9_req_t *req;
1461 	int retries = 0;
1462 
1463 	if (!fid) {
1464 		pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1465 			__func__, task_pid_nr(current));
1466 		dump_stack();
1467 		return 0;
1468 	}
1469 
1470 again:
1471 	p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1472 								retries);
1473 	err = 0;
1474 	clnt = fid->clnt;
1475 
1476 	req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1477 	if (IS_ERR(req)) {
1478 		err = PTR_ERR(req);
1479 		goto error;
1480 	}
1481 
1482 	p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1483 
1484 	p9_tag_remove(clnt, req);
1485 error:
1486 	/*
1487 	 * Fid is not valid even after a failed clunk
1488 	 * If interrupted, retry once then give up and
1489 	 * leak fid until umount.
1490 	 */
1491 	if (err == -ERESTARTSYS) {
1492 		if (retries++ == 0)
1493 			goto again;
1494 	} else
1495 		p9_fid_destroy(fid);
1496 	return err;
1497 }
1498 EXPORT_SYMBOL(p9_client_clunk);
1499 
p9_client_remove(struct p9_fid * fid)1500 int p9_client_remove(struct p9_fid *fid)
1501 {
1502 	int err;
1503 	struct p9_client *clnt;
1504 	struct p9_req_t *req;
1505 
1506 	p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1507 	err = 0;
1508 	clnt = fid->clnt;
1509 
1510 	req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1511 	if (IS_ERR(req)) {
1512 		err = PTR_ERR(req);
1513 		goto error;
1514 	}
1515 
1516 	p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1517 
1518 	p9_tag_remove(clnt, req);
1519 error:
1520 	if (err == -ERESTARTSYS)
1521 		p9_client_clunk(fid);
1522 	else
1523 		p9_fid_destroy(fid);
1524 	return err;
1525 }
1526 EXPORT_SYMBOL(p9_client_remove);
1527 
p9_client_unlinkat(struct p9_fid * dfid,const char * name,int flags)1528 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1529 {
1530 	int err = 0;
1531 	struct p9_req_t *req;
1532 	struct p9_client *clnt;
1533 
1534 	p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1535 		   dfid->fid, name, flags);
1536 
1537 	clnt = dfid->clnt;
1538 	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1539 	if (IS_ERR(req)) {
1540 		err = PTR_ERR(req);
1541 		goto error;
1542 	}
1543 	p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1544 
1545 	p9_tag_remove(clnt, req);
1546 error:
1547 	return err;
1548 }
1549 EXPORT_SYMBOL(p9_client_unlinkat);
1550 
1551 int
p9_client_read(struct p9_fid * fid,u64 offset,struct iov_iter * to,int * err)1552 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1553 {
1554 	int total = 0;
1555 	*err = 0;
1556 
1557 	while (iov_iter_count(to)) {
1558 		int count;
1559 
1560 		count = p9_client_read_once(fid, offset, to, err);
1561 		if (!count || *err)
1562 			break;
1563 		offset += count;
1564 		total += count;
1565 	}
1566 	return total;
1567 }
1568 EXPORT_SYMBOL(p9_client_read);
1569 
1570 int
p9_client_read_once(struct p9_fid * fid,u64 offset,struct iov_iter * to,int * err)1571 p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
1572 		    int *err)
1573 {
1574 	struct p9_client *clnt = fid->clnt;
1575 	struct p9_req_t *req;
1576 	int count = iov_iter_count(to);
1577 	int rsize, non_zc = 0;
1578 	char *dataptr;
1579 
1580 	*err = 0;
1581 	p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1582 		   fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1583 
1584 	rsize = fid->iounit;
1585 	if (!rsize || rsize > clnt->msize - P9_IOHDRSZ)
1586 		rsize = clnt->msize - P9_IOHDRSZ;
1587 
1588 	if (count < rsize)
1589 		rsize = count;
1590 
1591 	/* Don't bother zerocopy for small IO (< 1024) */
1592 	if (clnt->trans_mod->zc_request && rsize > 1024) {
1593 		/* response header len is 11
1594 		 * PDU Header(7) + IO Size (4)
1595 		 */
1596 		req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1597 				       0, 11, "dqd", fid->fid,
1598 				       offset, rsize);
1599 	} else {
1600 		non_zc = 1;
1601 		req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1602 				    rsize);
1603 	}
1604 	if (IS_ERR(req)) {
1605 		*err = PTR_ERR(req);
1606 		return 0;
1607 	}
1608 
1609 	*err = p9pdu_readf(&req->rc, clnt->proto_version,
1610 			   "D", &count, &dataptr);
1611 	if (*err) {
1612 		trace_9p_protocol_dump(clnt, &req->rc);
1613 		p9_tag_remove(clnt, req);
1614 		return 0;
1615 	}
1616 	if (rsize < count) {
1617 		pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1618 		count = rsize;
1619 	}
1620 
1621 	p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1622 
1623 	if (non_zc) {
1624 		int n = copy_to_iter(dataptr, count, to);
1625 
1626 		if (n != count) {
1627 			*err = -EFAULT;
1628 			p9_tag_remove(clnt, req);
1629 			return n;
1630 		}
1631 	} else {
1632 		iov_iter_advance(to, count);
1633 	}
1634 	p9_tag_remove(clnt, req);
1635 	return count;
1636 }
1637 EXPORT_SYMBOL(p9_client_read_once);
1638 
1639 int
p9_client_write(struct p9_fid * fid,u64 offset,struct iov_iter * from,int * err)1640 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1641 {
1642 	struct p9_client *clnt = fid->clnt;
1643 	struct p9_req_t *req;
1644 	int total = 0;
1645 	*err = 0;
1646 
1647 	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1648 				fid->fid, (unsigned long long) offset,
1649 				iov_iter_count(from));
1650 
1651 	while (iov_iter_count(from)) {
1652 		int count = iov_iter_count(from);
1653 		int rsize = fid->iounit;
1654 		if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1655 			rsize = clnt->msize - P9_IOHDRSZ;
1656 
1657 		if (count < rsize)
1658 			rsize = count;
1659 
1660 		/* Don't bother zerocopy for small IO (< 1024) */
1661 		if (clnt->trans_mod->zc_request && rsize > 1024) {
1662 			req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1663 					       rsize, P9_ZC_HDR_SZ, "dqd",
1664 					       fid->fid, offset, rsize);
1665 		} else {
1666 			req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1667 						    offset, rsize, from);
1668 		}
1669 		if (IS_ERR(req)) {
1670 			*err = PTR_ERR(req);
1671 			break;
1672 		}
1673 
1674 		*err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count);
1675 		if (*err) {
1676 			trace_9p_protocol_dump(clnt, &req->rc);
1677 			p9_tag_remove(clnt, req);
1678 			break;
1679 		}
1680 		if (rsize < count) {
1681 			pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1682 			count = rsize;
1683 		}
1684 
1685 		p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1686 
1687 		p9_tag_remove(clnt, req);
1688 		iov_iter_advance(from, count);
1689 		total += count;
1690 		offset += count;
1691 	}
1692 	return total;
1693 }
1694 EXPORT_SYMBOL(p9_client_write);
1695 
p9_client_stat(struct p9_fid * fid)1696 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1697 {
1698 	int err;
1699 	struct p9_client *clnt;
1700 	struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1701 	struct p9_req_t *req;
1702 	u16 ignored;
1703 
1704 	p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1705 
1706 	if (!ret)
1707 		return ERR_PTR(-ENOMEM);
1708 
1709 	err = 0;
1710 	clnt = fid->clnt;
1711 
1712 	req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1713 	if (IS_ERR(req)) {
1714 		err = PTR_ERR(req);
1715 		goto error;
1716 	}
1717 
1718 	err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
1719 	if (err) {
1720 		trace_9p_protocol_dump(clnt, &req->rc);
1721 		p9_tag_remove(clnt, req);
1722 		goto error;
1723 	}
1724 
1725 	p9_debug(P9_DEBUG_9P,
1726 		"<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1727 		"<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1728 		"<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1729 		"<<<    uid=%d gid=%d n_muid=%d\n",
1730 		ret->size, ret->type, ret->dev, ret->qid.type,
1731 		(unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1732 		ret->atime, ret->mtime, (unsigned long long)ret->length,
1733 		ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1734 		from_kuid(&init_user_ns, ret->n_uid),
1735 		from_kgid(&init_user_ns, ret->n_gid),
1736 		from_kuid(&init_user_ns, ret->n_muid));
1737 
1738 	p9_tag_remove(clnt, req);
1739 	return ret;
1740 
1741 error:
1742 	kfree(ret);
1743 	return ERR_PTR(err);
1744 }
1745 EXPORT_SYMBOL(p9_client_stat);
1746 
p9_client_getattr_dotl(struct p9_fid * fid,u64 request_mask)1747 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1748 							u64 request_mask)
1749 {
1750 	int err;
1751 	struct p9_client *clnt;
1752 	struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1753 								GFP_KERNEL);
1754 	struct p9_req_t *req;
1755 
1756 	p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1757 							fid->fid, request_mask);
1758 
1759 	if (!ret)
1760 		return ERR_PTR(-ENOMEM);
1761 
1762 	err = 0;
1763 	clnt = fid->clnt;
1764 
1765 	req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1766 	if (IS_ERR(req)) {
1767 		err = PTR_ERR(req);
1768 		goto error;
1769 	}
1770 
1771 	err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
1772 	if (err) {
1773 		trace_9p_protocol_dump(clnt, &req->rc);
1774 		p9_tag_remove(clnt, req);
1775 		goto error;
1776 	}
1777 
1778 	p9_debug(P9_DEBUG_9P,
1779 		"<<< RGETATTR st_result_mask=%lld\n"
1780 		"<<< qid=%x.%llx.%x\n"
1781 		"<<< st_mode=%8.8x st_nlink=%llu\n"
1782 		"<<< st_uid=%d st_gid=%d\n"
1783 		"<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1784 		"<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1785 		"<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1786 		"<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1787 		"<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1788 		"<<< st_gen=%lld st_data_version=%lld\n",
1789 		ret->st_result_mask, ret->qid.type, ret->qid.path,
1790 		ret->qid.version, ret->st_mode, ret->st_nlink,
1791 		from_kuid(&init_user_ns, ret->st_uid),
1792 		from_kgid(&init_user_ns, ret->st_gid),
1793 		ret->st_rdev, ret->st_size, ret->st_blksize,
1794 		ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1795 		ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1796 		ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1797 		ret->st_gen, ret->st_data_version);
1798 
1799 	p9_tag_remove(clnt, req);
1800 	return ret;
1801 
1802 error:
1803 	kfree(ret);
1804 	return ERR_PTR(err);
1805 }
1806 EXPORT_SYMBOL(p9_client_getattr_dotl);
1807 
p9_client_statsize(struct p9_wstat * wst,int proto_version)1808 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1809 {
1810 	int ret;
1811 
1812 	/* NOTE: size shouldn't include its own length */
1813 	/* size[2] type[2] dev[4] qid[13] */
1814 	/* mode[4] atime[4] mtime[4] length[8]*/
1815 	/* name[s] uid[s] gid[s] muid[s] */
1816 	ret = 2+4+13+4+4+4+8+2+2+2+2;
1817 
1818 	if (wst->name)
1819 		ret += strlen(wst->name);
1820 	if (wst->uid)
1821 		ret += strlen(wst->uid);
1822 	if (wst->gid)
1823 		ret += strlen(wst->gid);
1824 	if (wst->muid)
1825 		ret += strlen(wst->muid);
1826 
1827 	if ((proto_version == p9_proto_2000u) ||
1828 		(proto_version == p9_proto_2000L)) {
1829 		ret += 2+4+4+4;	/* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1830 		if (wst->extension)
1831 			ret += strlen(wst->extension);
1832 	}
1833 
1834 	return ret;
1835 }
1836 
p9_client_wstat(struct p9_fid * fid,struct p9_wstat * wst)1837 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1838 {
1839 	int err;
1840 	struct p9_req_t *req;
1841 	struct p9_client *clnt;
1842 
1843 	err = 0;
1844 	clnt = fid->clnt;
1845 	wst->size = p9_client_statsize(wst, clnt->proto_version);
1846 	p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1847 	p9_debug(P9_DEBUG_9P,
1848 		"     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1849 		"     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1850 		"     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1851 		"     uid=%d gid=%d n_muid=%d\n",
1852 		wst->size, wst->type, wst->dev, wst->qid.type,
1853 		(unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1854 		wst->atime, wst->mtime, (unsigned long long)wst->length,
1855 		wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1856 		from_kuid(&init_user_ns, wst->n_uid),
1857 		from_kgid(&init_user_ns, wst->n_gid),
1858 		from_kuid(&init_user_ns, wst->n_muid));
1859 
1860 	req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1861 	if (IS_ERR(req)) {
1862 		err = PTR_ERR(req);
1863 		goto error;
1864 	}
1865 
1866 	p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1867 
1868 	p9_tag_remove(clnt, req);
1869 error:
1870 	return err;
1871 }
1872 EXPORT_SYMBOL(p9_client_wstat);
1873 
p9_client_setattr(struct p9_fid * fid,struct p9_iattr_dotl * p9attr)1874 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1875 {
1876 	int err;
1877 	struct p9_req_t *req;
1878 	struct p9_client *clnt;
1879 
1880 	err = 0;
1881 	clnt = fid->clnt;
1882 	p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1883 	p9_debug(P9_DEBUG_9P,
1884 		"    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1885 		"    atime_sec=%lld atime_nsec=%lld\n"
1886 		"    mtime_sec=%lld mtime_nsec=%lld\n",
1887 		p9attr->valid, p9attr->mode,
1888 		from_kuid(&init_user_ns, p9attr->uid),
1889 		from_kgid(&init_user_ns, p9attr->gid),
1890 		p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1891 		p9attr->mtime_sec, p9attr->mtime_nsec);
1892 
1893 	req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1894 
1895 	if (IS_ERR(req)) {
1896 		err = PTR_ERR(req);
1897 		goto error;
1898 	}
1899 	p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1900 	p9_tag_remove(clnt, req);
1901 error:
1902 	return err;
1903 }
1904 EXPORT_SYMBOL(p9_client_setattr);
1905 
p9_client_statfs(struct p9_fid * fid,struct p9_rstatfs * sb)1906 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1907 {
1908 	int err;
1909 	struct p9_req_t *req;
1910 	struct p9_client *clnt;
1911 
1912 	err = 0;
1913 	clnt = fid->clnt;
1914 
1915 	p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1916 
1917 	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1918 	if (IS_ERR(req)) {
1919 		err = PTR_ERR(req);
1920 		goto error;
1921 	}
1922 
1923 	err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1924 			  &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1925 			  &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1926 	if (err) {
1927 		trace_9p_protocol_dump(clnt, &req->rc);
1928 		p9_tag_remove(clnt, req);
1929 		goto error;
1930 	}
1931 
1932 	p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1933 		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1934 		"fsid %llu namelen %ld\n",
1935 		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1936 		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1937 		sb->fsid, (long int)sb->namelen);
1938 
1939 	p9_tag_remove(clnt, req);
1940 error:
1941 	return err;
1942 }
1943 EXPORT_SYMBOL(p9_client_statfs);
1944 
p9_client_rename(struct p9_fid * fid,struct p9_fid * newdirfid,const char * name)1945 int p9_client_rename(struct p9_fid *fid,
1946 		     struct p9_fid *newdirfid, const char *name)
1947 {
1948 	int err;
1949 	struct p9_req_t *req;
1950 	struct p9_client *clnt;
1951 
1952 	err = 0;
1953 	clnt = fid->clnt;
1954 
1955 	p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1956 			fid->fid, newdirfid->fid, name);
1957 
1958 	req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1959 			newdirfid->fid, name);
1960 	if (IS_ERR(req)) {
1961 		err = PTR_ERR(req);
1962 		goto error;
1963 	}
1964 
1965 	p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1966 
1967 	p9_tag_remove(clnt, req);
1968 error:
1969 	return err;
1970 }
1971 EXPORT_SYMBOL(p9_client_rename);
1972 
p9_client_renameat(struct p9_fid * olddirfid,const char * old_name,struct p9_fid * newdirfid,const char * new_name)1973 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1974 		       struct p9_fid *newdirfid, const char *new_name)
1975 {
1976 	int err;
1977 	struct p9_req_t *req;
1978 	struct p9_client *clnt;
1979 
1980 	err = 0;
1981 	clnt = olddirfid->clnt;
1982 
1983 	p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1984 		   " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1985 		   newdirfid->fid, new_name);
1986 
1987 	req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1988 			    old_name, newdirfid->fid, new_name);
1989 	if (IS_ERR(req)) {
1990 		err = PTR_ERR(req);
1991 		goto error;
1992 	}
1993 
1994 	p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1995 		   newdirfid->fid, new_name);
1996 
1997 	p9_tag_remove(clnt, req);
1998 error:
1999 	return err;
2000 }
2001 EXPORT_SYMBOL(p9_client_renameat);
2002 
2003 /*
2004  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
2005  */
p9_client_xattrwalk(struct p9_fid * file_fid,const char * attr_name,u64 * attr_size)2006 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
2007 				const char *attr_name, u64 *attr_size)
2008 {
2009 	int err;
2010 	struct p9_req_t *req;
2011 	struct p9_client *clnt;
2012 	struct p9_fid *attr_fid;
2013 
2014 	err = 0;
2015 	clnt = file_fid->clnt;
2016 	attr_fid = p9_fid_create(clnt);
2017 	if (!attr_fid) {
2018 		err = -ENOMEM;
2019 		goto error;
2020 	}
2021 	p9_debug(P9_DEBUG_9P,
2022 		">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2023 		file_fid->fid, attr_fid->fid, attr_name);
2024 
2025 	req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2026 			file_fid->fid, attr_fid->fid, attr_name);
2027 	if (IS_ERR(req)) {
2028 		err = PTR_ERR(req);
2029 		goto error;
2030 	}
2031 	err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
2032 	if (err) {
2033 		trace_9p_protocol_dump(clnt, &req->rc);
2034 		p9_tag_remove(clnt, req);
2035 		goto clunk_fid;
2036 	}
2037 	p9_tag_remove(clnt, req);
2038 	p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2039 		attr_fid->fid, *attr_size);
2040 	return attr_fid;
2041 clunk_fid:
2042 	p9_client_clunk(attr_fid);
2043 	attr_fid = NULL;
2044 error:
2045 	if (attr_fid && (attr_fid != file_fid))
2046 		p9_fid_destroy(attr_fid);
2047 
2048 	return ERR_PTR(err);
2049 }
2050 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2051 
p9_client_xattrcreate(struct p9_fid * fid,const char * name,u64 attr_size,int flags)2052 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2053 			u64 attr_size, int flags)
2054 {
2055 	int err;
2056 	struct p9_req_t *req;
2057 	struct p9_client *clnt;
2058 
2059 	p9_debug(P9_DEBUG_9P,
2060 		">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2061 		fid->fid, name, (long long)attr_size, flags);
2062 	err = 0;
2063 	clnt = fid->clnt;
2064 	req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2065 			fid->fid, name, attr_size, flags);
2066 	if (IS_ERR(req)) {
2067 		err = PTR_ERR(req);
2068 		goto error;
2069 	}
2070 	p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2071 	p9_tag_remove(clnt, req);
2072 error:
2073 	return err;
2074 }
2075 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2076 
p9_client_readdir(struct p9_fid * fid,char * data,u32 count,u64 offset)2077 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2078 {
2079 	int err, rsize, non_zc = 0;
2080 	struct p9_client *clnt;
2081 	struct p9_req_t *req;
2082 	char *dataptr;
2083 	struct kvec kv = {.iov_base = data, .iov_len = count};
2084 	struct iov_iter to;
2085 
2086 	iov_iter_kvec(&to, READ, &kv, 1, count);
2087 
2088 	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2089 				fid->fid, (unsigned long long) offset, count);
2090 
2091 	err = 0;
2092 	clnt = fid->clnt;
2093 
2094 	rsize = fid->iounit;
2095 	if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2096 		rsize = clnt->msize - P9_READDIRHDRSZ;
2097 
2098 	if (count < rsize)
2099 		rsize = count;
2100 
2101 	/* Don't bother zerocopy for small IO (< 1024) */
2102 	if (clnt->trans_mod->zc_request && rsize > 1024) {
2103 		/*
2104 		 * response header len is 11
2105 		 * PDU Header(7) + IO Size (4)
2106 		 */
2107 		req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2108 				       11, "dqd", fid->fid, offset, rsize);
2109 	} else {
2110 		non_zc = 1;
2111 		req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2112 				    offset, rsize);
2113 	}
2114 	if (IS_ERR(req)) {
2115 		err = PTR_ERR(req);
2116 		goto error;
2117 	}
2118 
2119 	err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
2120 	if (err) {
2121 		trace_9p_protocol_dump(clnt, &req->rc);
2122 		goto free_and_error;
2123 	}
2124 	if (rsize < count) {
2125 		pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2126 		count = rsize;
2127 	}
2128 
2129 	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2130 
2131 	if (non_zc)
2132 		memmove(data, dataptr, count);
2133 
2134 	p9_tag_remove(clnt, req);
2135 	return count;
2136 
2137 free_and_error:
2138 	p9_tag_remove(clnt, req);
2139 error:
2140 	return err;
2141 }
2142 EXPORT_SYMBOL(p9_client_readdir);
2143 
p9_client_mknod_dotl(struct p9_fid * fid,const char * name,int mode,dev_t rdev,kgid_t gid,struct p9_qid * qid)2144 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2145 			dev_t rdev, kgid_t gid, struct p9_qid *qid)
2146 {
2147 	int err;
2148 	struct p9_client *clnt;
2149 	struct p9_req_t *req;
2150 
2151 	err = 0;
2152 	clnt = fid->clnt;
2153 	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2154 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2155 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2156 		MAJOR(rdev), MINOR(rdev), gid);
2157 	if (IS_ERR(req))
2158 		return PTR_ERR(req);
2159 
2160 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2161 	if (err) {
2162 		trace_9p_protocol_dump(clnt, &req->rc);
2163 		goto error;
2164 	}
2165 	p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2166 				(unsigned long long)qid->path, qid->version);
2167 
2168 error:
2169 	p9_tag_remove(clnt, req);
2170 	return err;
2171 
2172 }
2173 EXPORT_SYMBOL(p9_client_mknod_dotl);
2174 
p9_client_mkdir_dotl(struct p9_fid * fid,const char * name,int mode,kgid_t gid,struct p9_qid * qid)2175 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2176 				kgid_t gid, struct p9_qid *qid)
2177 {
2178 	int err;
2179 	struct p9_client *clnt;
2180 	struct p9_req_t *req;
2181 
2182 	err = 0;
2183 	clnt = fid->clnt;
2184 	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2185 		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2186 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2187 		gid);
2188 	if (IS_ERR(req))
2189 		return PTR_ERR(req);
2190 
2191 	err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2192 	if (err) {
2193 		trace_9p_protocol_dump(clnt, &req->rc);
2194 		goto error;
2195 	}
2196 	p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2197 				(unsigned long long)qid->path, qid->version);
2198 
2199 error:
2200 	p9_tag_remove(clnt, req);
2201 	return err;
2202 
2203 }
2204 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2205 
p9_client_lock_dotl(struct p9_fid * fid,struct p9_flock * flock,u8 * status)2206 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2207 {
2208 	int err;
2209 	struct p9_client *clnt;
2210 	struct p9_req_t *req;
2211 
2212 	err = 0;
2213 	clnt = fid->clnt;
2214 	p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2215 			"start %lld length %lld proc_id %d client_id %s\n",
2216 			fid->fid, flock->type, flock->flags, flock->start,
2217 			flock->length, flock->proc_id, flock->client_id);
2218 
2219 	req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2220 				flock->flags, flock->start, flock->length,
2221 					flock->proc_id, flock->client_id);
2222 
2223 	if (IS_ERR(req))
2224 		return PTR_ERR(req);
2225 
2226 	err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
2227 	if (err) {
2228 		trace_9p_protocol_dump(clnt, &req->rc);
2229 		goto error;
2230 	}
2231 	p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2232 error:
2233 	p9_tag_remove(clnt, req);
2234 	return err;
2235 
2236 }
2237 EXPORT_SYMBOL(p9_client_lock_dotl);
2238 
p9_client_getlock_dotl(struct p9_fid * fid,struct p9_getlock * glock)2239 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2240 {
2241 	int err;
2242 	struct p9_client *clnt;
2243 	struct p9_req_t *req;
2244 
2245 	err = 0;
2246 	clnt = fid->clnt;
2247 	p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2248 		"length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2249 		glock->start, glock->length, glock->proc_id, glock->client_id);
2250 
2251 	req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2252 		glock->start, glock->length, glock->proc_id, glock->client_id);
2253 
2254 	if (IS_ERR(req))
2255 		return PTR_ERR(req);
2256 
2257 	err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type,
2258 			  &glock->start, &glock->length, &glock->proc_id,
2259 			  &glock->client_id);
2260 	if (err) {
2261 		trace_9p_protocol_dump(clnt, &req->rc);
2262 		goto error;
2263 	}
2264 	p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2265 		"proc_id %d client_id %s\n", glock->type, glock->start,
2266 		glock->length, glock->proc_id, glock->client_id);
2267 error:
2268 	p9_tag_remove(clnt, req);
2269 	return err;
2270 }
2271 EXPORT_SYMBOL(p9_client_getlock_dotl);
2272 
p9_client_readlink(struct p9_fid * fid,char ** target)2273 int p9_client_readlink(struct p9_fid *fid, char **target)
2274 {
2275 	int err;
2276 	struct p9_client *clnt;
2277 	struct p9_req_t *req;
2278 
2279 	err = 0;
2280 	clnt = fid->clnt;
2281 	p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2282 
2283 	req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2284 	if (IS_ERR(req))
2285 		return PTR_ERR(req);
2286 
2287 	err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
2288 	if (err) {
2289 		trace_9p_protocol_dump(clnt, &req->rc);
2290 		goto error;
2291 	}
2292 	p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2293 error:
2294 	p9_tag_remove(clnt, req);
2295 	return err;
2296 }
2297 EXPORT_SYMBOL(p9_client_readlink);
2298 
p9_client_init(void)2299 int __init p9_client_init(void)
2300 {
2301 	p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU);
2302 	return p9_req_cache ? 0 : -ENOMEM;
2303 }
2304 
p9_client_exit(void)2305 void __exit p9_client_exit(void)
2306 {
2307 	kmem_cache_destroy(p9_req_cache);
2308 }
2309