xref: /openbmc/linux/net/9p/client.c (revision 384740dc) 
1 /*
2  * net/9p/clnt.c
3  *
4  * 9P Client
5  *
6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2
11  *  as published by the Free Software Foundation.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to:
20  *  Free Software Foundation
21  *  51 Franklin Street, Fifth Floor
22  *  Boston, MA  02111-1301  USA
23  *
24  */
25 
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/fs.h>
29 #include <linux/poll.h>
30 #include <linux/idr.h>
31 #include <linux/mutex.h>
32 #include <linux/sched.h>
33 #include <linux/uaccess.h>
34 #include <net/9p/9p.h>
35 #include <linux/parser.h>
36 #include <net/9p/transport.h>
37 #include <net/9p/client.h>
38 
39 static struct p9_fid *p9_fid_create(struct p9_client *clnt);
40 static void p9_fid_destroy(struct p9_fid *fid);
41 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu);
42 
43 /*
44   * Client Option Parsing (code inspired by NFS code)
45   *  - a little lazy - parse all client options
46   */
47 
48 enum {
49 	Opt_msize,
50 	Opt_trans,
51 	Opt_legacy,
52 	Opt_err,
53 };
54 
55 static match_table_t tokens = {
56 	{Opt_msize, "msize=%u"},
57 	{Opt_legacy, "noextend"},
58 	{Opt_trans, "trans=%s"},
59 	{Opt_err, NULL},
60 };
61 
62 /**
63  * v9fs_parse_options - parse mount options into session structure
64  * @options: options string passed from mount
65  * @v9ses: existing v9fs session information
66  *
67  * Return 0 upon success, -ERRNO upon failure
68  */
69 
70 static int parse_opts(char *opts, struct p9_client *clnt)
71 {
72 	char *options;
73 	char *p;
74 	substring_t args[MAX_OPT_ARGS];
75 	int option;
76 	int ret = 0;
77 
78 	clnt->dotu = 1;
79 	clnt->msize = 8192;
80 
81 	if (!opts)
82 		return 0;
83 
84 	options = kstrdup(opts, GFP_KERNEL);
85 	if (!options) {
86 		P9_DPRINTK(P9_DEBUG_ERROR,
87 				"failed to allocate copy of option string\n");
88 		return -ENOMEM;
89 	}
90 
91 	while ((p = strsep(&options, ",")) != NULL) {
92 		int token;
93 		if (!*p)
94 			continue;
95 		token = match_token(p, tokens, args);
96 		if (token < Opt_trans) {
97 			int r = match_int(&args[0], &option);
98 			if (r < 0) {
99 				P9_DPRINTK(P9_DEBUG_ERROR,
100 					"integer field, but no integer?\n");
101 				ret = r;
102 				continue;
103 			}
104 		}
105 		switch (token) {
106 		case Opt_msize:
107 			clnt->msize = option;
108 			break;
109 		case Opt_trans:
110 			clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
111 			break;
112 		case Opt_legacy:
113 			clnt->dotu = 0;
114 			break;
115 		default:
116 			continue;
117 		}
118 	}
119 
120 	if (!clnt->trans_mod)
121 		clnt->trans_mod = v9fs_get_default_trans();
122 
123 	kfree(options);
124 	return ret;
125 }
126 
127 
128 /**
129  * p9_client_rpc - sends 9P request and waits until a response is available.
130  *      The function can be interrupted.
131  * @c: client data
132  * @tc: request to be sent
133  * @rc: pointer where a pointer to the response is stored
134  */
135 int
136 p9_client_rpc(struct p9_client *c, struct p9_fcall *tc,
137 	struct p9_fcall **rc)
138 {
139 	return c->trans->rpc(c->trans, tc, rc);
140 }
141 
142 struct p9_client *p9_client_create(const char *dev_name, char *options)
143 {
144 	int err, n;
145 	struct p9_client *clnt;
146 	struct p9_fcall *tc, *rc;
147 	struct p9_str *version;
148 
149 	err = 0;
150 	tc = NULL;
151 	rc = NULL;
152 	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
153 	if (!clnt)
154 		return ERR_PTR(-ENOMEM);
155 
156 	clnt->trans_mod = NULL;
157 	clnt->trans = NULL;
158 	spin_lock_init(&clnt->lock);
159 	INIT_LIST_HEAD(&clnt->fidlist);
160 	clnt->fidpool = p9_idpool_create();
161 	if (IS_ERR(clnt->fidpool)) {
162 		err = PTR_ERR(clnt->fidpool);
163 		clnt->fidpool = NULL;
164 		goto error;
165 	}
166 
167 	err = parse_opts(options, clnt);
168 	if (err < 0)
169 		goto error;
170 
171 	if (clnt->trans_mod == NULL) {
172 		err = -EPROTONOSUPPORT;
173 		P9_DPRINTK(P9_DEBUG_ERROR,
174 				"No transport defined or default transport\n");
175 		goto error;
176 	}
177 
178 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
179 		clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
180 
181 
182 	clnt->trans = clnt->trans_mod->create(dev_name, options, clnt->msize,
183 								clnt->dotu);
184 	if (IS_ERR(clnt->trans)) {
185 		err = PTR_ERR(clnt->trans);
186 		clnt->trans = NULL;
187 		goto error;
188 	}
189 
190 	if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
191 		clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
192 
193 	tc = p9_create_tversion(clnt->msize, clnt->dotu?"9P2000.u":"9P2000");
194 	if (IS_ERR(tc)) {
195 		err = PTR_ERR(tc);
196 		tc = NULL;
197 		goto error;
198 	}
199 
200 	err = p9_client_rpc(clnt, tc, &rc);
201 	if (err)
202 		goto error;
203 
204 	version = &rc->params.rversion.version;
205 	if (version->len == 8 && !memcmp(version->str, "9P2000.u", 8))
206 		clnt->dotu = 1;
207 	else if (version->len == 6 && !memcmp(version->str, "9P2000", 6))
208 		clnt->dotu = 0;
209 	else {
210 		err = -EREMOTEIO;
211 		goto error;
212 	}
213 
214 	n = rc->params.rversion.msize;
215 	if (n < clnt->msize)
216 		clnt->msize = n;
217 
218 	kfree(tc);
219 	kfree(rc);
220 	return clnt;
221 
222 error:
223 	kfree(tc);
224 	kfree(rc);
225 	p9_client_destroy(clnt);
226 	return ERR_PTR(err);
227 }
228 EXPORT_SYMBOL(p9_client_create);
229 
230 void p9_client_destroy(struct p9_client *clnt)
231 {
232 	struct p9_fid *fid, *fidptr;
233 
234 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
235 
236 	if (clnt->trans) {
237 		clnt->trans->close(clnt->trans);
238 		kfree(clnt->trans);
239 		clnt->trans = NULL;
240 	}
241 
242 	v9fs_put_trans(clnt->trans_mod);
243 
244 	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
245 		p9_fid_destroy(fid);
246 
247 	if (clnt->fidpool)
248 		p9_idpool_destroy(clnt->fidpool);
249 
250 	kfree(clnt);
251 }
252 EXPORT_SYMBOL(p9_client_destroy);
253 
254 void p9_client_disconnect(struct p9_client *clnt)
255 {
256 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
257 	clnt->trans->status = Disconnected;
258 }
259 EXPORT_SYMBOL(p9_client_disconnect);
260 
261 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
262 	char *uname, u32 n_uname, char *aname)
263 {
264 	int err;
265 	struct p9_fcall *tc, *rc;
266 	struct p9_fid *fid;
267 
268 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p afid %d uname %s aname %s\n",
269 		clnt, afid?afid->fid:-1, uname, aname);
270 	err = 0;
271 	tc = NULL;
272 	rc = NULL;
273 
274 	fid = p9_fid_create(clnt);
275 	if (IS_ERR(fid)) {
276 		err = PTR_ERR(fid);
277 		fid = NULL;
278 		goto error;
279 	}
280 
281 	tc = p9_create_tattach(fid->fid, afid?afid->fid:P9_NOFID, uname, aname,
282 		n_uname, clnt->dotu);
283 	if (IS_ERR(tc)) {
284 		err = PTR_ERR(tc);
285 		tc = NULL;
286 		goto error;
287 	}
288 
289 	err = p9_client_rpc(clnt, tc, &rc);
290 	if (err)
291 		goto error;
292 
293 	memmove(&fid->qid, &rc->params.rattach.qid, sizeof(struct p9_qid));
294 	kfree(tc);
295 	kfree(rc);
296 	return fid;
297 
298 error:
299 	kfree(tc);
300 	kfree(rc);
301 	if (fid)
302 		p9_fid_destroy(fid);
303 	return ERR_PTR(err);
304 }
305 EXPORT_SYMBOL(p9_client_attach);
306 
307 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
308 	u32 n_uname, char *aname)
309 {
310 	int err;
311 	struct p9_fcall *tc, *rc;
312 	struct p9_fid *fid;
313 
314 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p uname %s aname %s\n", clnt, uname,
315 									aname);
316 	err = 0;
317 	tc = NULL;
318 	rc = NULL;
319 
320 	fid = p9_fid_create(clnt);
321 	if (IS_ERR(fid)) {
322 		err = PTR_ERR(fid);
323 		fid = NULL;
324 		goto error;
325 	}
326 
327 	tc = p9_create_tauth(fid->fid, uname, aname, n_uname, clnt->dotu);
328 	if (IS_ERR(tc)) {
329 		err = PTR_ERR(tc);
330 		tc = NULL;
331 		goto error;
332 	}
333 
334 	err = p9_client_rpc(clnt, tc, &rc);
335 	if (err)
336 		goto error;
337 
338 	memmove(&fid->qid, &rc->params.rauth.qid, sizeof(struct p9_qid));
339 	kfree(tc);
340 	kfree(rc);
341 	return fid;
342 
343 error:
344 	kfree(tc);
345 	kfree(rc);
346 	if (fid)
347 		p9_fid_destroy(fid);
348 	return ERR_PTR(err);
349 }
350 EXPORT_SYMBOL(p9_client_auth);
351 
352 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
353 	int clone)
354 {
355 	int err;
356 	struct p9_fcall *tc, *rc;
357 	struct p9_client *clnt;
358 	struct p9_fid *fid;
359 
360 	P9_DPRINTK(P9_DEBUG_9P, "fid %d nwname %d wname[0] %s\n",
361 		oldfid->fid, nwname, wnames?wnames[0]:NULL);
362 	err = 0;
363 	tc = NULL;
364 	rc = NULL;
365 	clnt = oldfid->clnt;
366 	if (clone) {
367 		fid = p9_fid_create(clnt);
368 		if (IS_ERR(fid)) {
369 			err = PTR_ERR(fid);
370 			fid = NULL;
371 			goto error;
372 		}
373 
374 		fid->uid = oldfid->uid;
375 	} else
376 		fid = oldfid;
377 
378 	tc = p9_create_twalk(oldfid->fid, fid->fid, nwname, wnames);
379 	if (IS_ERR(tc)) {
380 		err = PTR_ERR(tc);
381 		tc = NULL;
382 		goto error;
383 	}
384 
385 	err = p9_client_rpc(clnt, tc, &rc);
386 	if (err) {
387 		if (rc && rc->id == P9_RWALK)
388 			goto clunk_fid;
389 		else
390 			goto error;
391 	}
392 
393 	if (rc->params.rwalk.nwqid != nwname) {
394 		err = -ENOENT;
395 		goto clunk_fid;
396 	}
397 
398 	if (nwname)
399 		memmove(&fid->qid,
400 			&rc->params.rwalk.wqids[rc->params.rwalk.nwqid - 1],
401 			sizeof(struct p9_qid));
402 	else
403 		fid->qid = oldfid->qid;
404 
405 	kfree(tc);
406 	kfree(rc);
407 	return fid;
408 
409 clunk_fid:
410 	kfree(tc);
411 	kfree(rc);
412 	rc = NULL;
413 	tc = p9_create_tclunk(fid->fid);
414 	if (IS_ERR(tc)) {
415 		err = PTR_ERR(tc);
416 		tc = NULL;
417 		goto error;
418 	}
419 
420 	p9_client_rpc(clnt, tc, &rc);
421 
422 error:
423 	kfree(tc);
424 	kfree(rc);
425 	if (fid && (fid != oldfid))
426 		p9_fid_destroy(fid);
427 
428 	return ERR_PTR(err);
429 }
430 EXPORT_SYMBOL(p9_client_walk);
431 
432 int p9_client_open(struct p9_fid *fid, int mode)
433 {
434 	int err;
435 	struct p9_fcall *tc, *rc;
436 	struct p9_client *clnt;
437 
438 	P9_DPRINTK(P9_DEBUG_9P, "fid %d mode %d\n", fid->fid, mode);
439 	err = 0;
440 	tc = NULL;
441 	rc = NULL;
442 	clnt = fid->clnt;
443 
444 	if (fid->mode != -1)
445 		return -EINVAL;
446 
447 	tc = p9_create_topen(fid->fid, mode);
448 	if (IS_ERR(tc)) {
449 		err = PTR_ERR(tc);
450 		tc = NULL;
451 		goto done;
452 	}
453 
454 	err = p9_client_rpc(clnt, tc, &rc);
455 	if (err)
456 		goto done;
457 
458 	fid->mode = mode;
459 	fid->iounit = rc->params.ropen.iounit;
460 
461 done:
462 	kfree(tc);
463 	kfree(rc);
464 	return err;
465 }
466 EXPORT_SYMBOL(p9_client_open);
467 
468 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
469 		     char *extension)
470 {
471 	int err;
472 	struct p9_fcall *tc, *rc;
473 	struct p9_client *clnt;
474 
475 	P9_DPRINTK(P9_DEBUG_9P, "fid %d name %s perm %d mode %d\n", fid->fid,
476 		name, perm, mode);
477 	err = 0;
478 	tc = NULL;
479 	rc = NULL;
480 	clnt = fid->clnt;
481 
482 	if (fid->mode != -1)
483 		return -EINVAL;
484 
485 	tc = p9_create_tcreate(fid->fid, name, perm, mode, extension,
486 							       clnt->dotu);
487 	if (IS_ERR(tc)) {
488 		err = PTR_ERR(tc);
489 		tc = NULL;
490 		goto done;
491 	}
492 
493 	err = p9_client_rpc(clnt, tc, &rc);
494 	if (err)
495 		goto done;
496 
497 	fid->mode = mode;
498 	fid->iounit = rc->params.ropen.iounit;
499 
500 done:
501 	kfree(tc);
502 	kfree(rc);
503 	return err;
504 }
505 EXPORT_SYMBOL(p9_client_fcreate);
506 
507 int p9_client_clunk(struct p9_fid *fid)
508 {
509 	int err;
510 	struct p9_fcall *tc, *rc;
511 	struct p9_client *clnt;
512 
513 	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
514 	err = 0;
515 	tc = NULL;
516 	rc = NULL;
517 	clnt = fid->clnt;
518 
519 	tc = p9_create_tclunk(fid->fid);
520 	if (IS_ERR(tc)) {
521 		err = PTR_ERR(tc);
522 		tc = NULL;
523 		goto done;
524 	}
525 
526 	err = p9_client_rpc(clnt, tc, &rc);
527 	if (err)
528 		goto done;
529 
530 	p9_fid_destroy(fid);
531 
532 done:
533 	kfree(tc);
534 	kfree(rc);
535 	return err;
536 }
537 EXPORT_SYMBOL(p9_client_clunk);
538 
539 int p9_client_remove(struct p9_fid *fid)
540 {
541 	int err;
542 	struct p9_fcall *tc, *rc;
543 	struct p9_client *clnt;
544 
545 	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
546 	err = 0;
547 	tc = NULL;
548 	rc = NULL;
549 	clnt = fid->clnt;
550 
551 	tc = p9_create_tremove(fid->fid);
552 	if (IS_ERR(tc)) {
553 		err = PTR_ERR(tc);
554 		tc = NULL;
555 		goto done;
556 	}
557 
558 	err = p9_client_rpc(clnt, tc, &rc);
559 	if (err)
560 		goto done;
561 
562 	p9_fid_destroy(fid);
563 
564 done:
565 	kfree(tc);
566 	kfree(rc);
567 	return err;
568 }
569 EXPORT_SYMBOL(p9_client_remove);
570 
571 int p9_client_read(struct p9_fid *fid, char *data, u64 offset, u32 count)
572 {
573 	int err, n, rsize, total;
574 	struct p9_fcall *tc, *rc;
575 	struct p9_client *clnt;
576 
577 	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu %d\n", fid->fid,
578 					(long long unsigned) offset, count);
579 	err = 0;
580 	tc = NULL;
581 	rc = NULL;
582 	clnt = fid->clnt;
583 	total = 0;
584 
585 	rsize = fid->iounit;
586 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
587 		rsize = clnt->msize - P9_IOHDRSZ;
588 
589 	do {
590 		if (count < rsize)
591 			rsize = count;
592 
593 		tc = p9_create_tread(fid->fid, offset, rsize);
594 		if (IS_ERR(tc)) {
595 			err = PTR_ERR(tc);
596 			tc = NULL;
597 			goto error;
598 		}
599 
600 		err = p9_client_rpc(clnt, tc, &rc);
601 		if (err)
602 			goto error;
603 
604 		n = rc->params.rread.count;
605 		if (n > count)
606 			n = count;
607 
608 		memmove(data, rc->params.rread.data, n);
609 		count -= n;
610 		data += n;
611 		offset += n;
612 		total += n;
613 		kfree(tc);
614 		tc = NULL;
615 		kfree(rc);
616 		rc = NULL;
617 	} while (count > 0 && n == rsize);
618 
619 	return total;
620 
621 error:
622 	kfree(tc);
623 	kfree(rc);
624 	return err;
625 }
626 EXPORT_SYMBOL(p9_client_read);
627 
628 int p9_client_write(struct p9_fid *fid, char *data, u64 offset, u32 count)
629 {
630 	int err, n, rsize, total;
631 	struct p9_fcall *tc, *rc;
632 	struct p9_client *clnt;
633 
634 	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
635 					(long long unsigned) offset, count);
636 	err = 0;
637 	tc = NULL;
638 	rc = NULL;
639 	clnt = fid->clnt;
640 	total = 0;
641 
642 	rsize = fid->iounit;
643 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
644 		rsize = clnt->msize - P9_IOHDRSZ;
645 
646 	do {
647 		if (count < rsize)
648 			rsize = count;
649 
650 		tc = p9_create_twrite(fid->fid, offset, rsize, data);
651 		if (IS_ERR(tc)) {
652 			err = PTR_ERR(tc);
653 			tc = NULL;
654 			goto error;
655 		}
656 
657 		err = p9_client_rpc(clnt, tc, &rc);
658 		if (err)
659 			goto error;
660 
661 		n = rc->params.rread.count;
662 		count -= n;
663 		data += n;
664 		offset += n;
665 		total += n;
666 		kfree(tc);
667 		tc = NULL;
668 		kfree(rc);
669 		rc = NULL;
670 	} while (count > 0);
671 
672 	return total;
673 
674 error:
675 	kfree(tc);
676 	kfree(rc);
677 	return err;
678 }
679 EXPORT_SYMBOL(p9_client_write);
680 
681 int
682 p9_client_uread(struct p9_fid *fid, char __user *data, u64 offset, u32 count)
683 {
684 	int err, n, rsize, total;
685 	struct p9_fcall *tc, *rc;
686 	struct p9_client *clnt;
687 
688 	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
689 					(long long unsigned) offset, count);
690 	err = 0;
691 	tc = NULL;
692 	rc = NULL;
693 	clnt = fid->clnt;
694 	total = 0;
695 
696 	rsize = fid->iounit;
697 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
698 		rsize = clnt->msize - P9_IOHDRSZ;
699 
700 	do {
701 		if (count < rsize)
702 			rsize = count;
703 
704 		tc = p9_create_tread(fid->fid, offset, rsize);
705 		if (IS_ERR(tc)) {
706 			err = PTR_ERR(tc);
707 			tc = NULL;
708 			goto error;
709 		}
710 
711 		err = p9_client_rpc(clnt, tc, &rc);
712 		if (err)
713 			goto error;
714 
715 		n = rc->params.rread.count;
716 		if (n > count)
717 			n = count;
718 
719 		err = copy_to_user(data, rc->params.rread.data, n);
720 		if (err) {
721 			err = -EFAULT;
722 			goto error;
723 		}
724 
725 		count -= n;
726 		data += n;
727 		offset += n;
728 		total += n;
729 		kfree(tc);
730 		tc = NULL;
731 		kfree(rc);
732 		rc = NULL;
733 	} while (count > 0 && n == rsize);
734 
735 	return total;
736 
737 error:
738 	kfree(tc);
739 	kfree(rc);
740 	return err;
741 }
742 EXPORT_SYMBOL(p9_client_uread);
743 
744 int
745 p9_client_uwrite(struct p9_fid *fid, const char __user *data, u64 offset,
746 								   u32 count)
747 {
748 	int err, n, rsize, total;
749 	struct p9_fcall *tc, *rc;
750 	struct p9_client *clnt;
751 
752 	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
753 					(long long unsigned) offset, count);
754 	err = 0;
755 	tc = NULL;
756 	rc = NULL;
757 	clnt = fid->clnt;
758 	total = 0;
759 
760 	rsize = fid->iounit;
761 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
762 		rsize = clnt->msize - P9_IOHDRSZ;
763 
764 	do {
765 		if (count < rsize)
766 			rsize = count;
767 
768 		tc = p9_create_twrite_u(fid->fid, offset, rsize, data);
769 		if (IS_ERR(tc)) {
770 			err = PTR_ERR(tc);
771 			tc = NULL;
772 			goto error;
773 		}
774 
775 		err = p9_client_rpc(clnt, tc, &rc);
776 		if (err)
777 			goto error;
778 
779 		n = rc->params.rread.count;
780 		count -= n;
781 		data += n;
782 		offset += n;
783 		total += n;
784 		kfree(tc);
785 		tc = NULL;
786 		kfree(rc);
787 		rc = NULL;
788 	} while (count > 0);
789 
790 	return total;
791 
792 error:
793 	kfree(tc);
794 	kfree(rc);
795 	return err;
796 }
797 EXPORT_SYMBOL(p9_client_uwrite);
798 
799 int p9_client_readn(struct p9_fid *fid, char *data, u64 offset, u32 count)
800 {
801 	int n, total;
802 
803 	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
804 					(long long unsigned) offset, count);
805 	n = 0;
806 	total = 0;
807 	while (count) {
808 		n = p9_client_read(fid, data, offset, count);
809 		if (n <= 0)
810 			break;
811 
812 		data += n;
813 		offset += n;
814 		count -= n;
815 		total += n;
816 	}
817 
818 	if (n < 0)
819 		total = n;
820 
821 	return total;
822 }
823 EXPORT_SYMBOL(p9_client_readn);
824 
825 struct p9_stat *p9_client_stat(struct p9_fid *fid)
826 {
827 	int err;
828 	struct p9_fcall *tc, *rc;
829 	struct p9_client *clnt;
830 	struct p9_stat *ret;
831 
832 	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
833 	err = 0;
834 	tc = NULL;
835 	rc = NULL;
836 	ret = NULL;
837 	clnt = fid->clnt;
838 
839 	tc = p9_create_tstat(fid->fid);
840 	if (IS_ERR(tc)) {
841 		err = PTR_ERR(tc);
842 		tc = NULL;
843 		goto error;
844 	}
845 
846 	err = p9_client_rpc(clnt, tc, &rc);
847 	if (err)
848 		goto error;
849 
850 	ret = p9_clone_stat(&rc->params.rstat.stat, clnt->dotu);
851 	if (IS_ERR(ret)) {
852 		err = PTR_ERR(ret);
853 		ret = NULL;
854 		goto error;
855 	}
856 
857 	kfree(tc);
858 	kfree(rc);
859 	return ret;
860 
861 error:
862 	kfree(tc);
863 	kfree(rc);
864 	kfree(ret);
865 	return ERR_PTR(err);
866 }
867 EXPORT_SYMBOL(p9_client_stat);
868 
869 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
870 {
871 	int err;
872 	struct p9_fcall *tc, *rc;
873 	struct p9_client *clnt;
874 
875 	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
876 	err = 0;
877 	tc = NULL;
878 	rc = NULL;
879 	clnt = fid->clnt;
880 
881 	tc = p9_create_twstat(fid->fid, wst, clnt->dotu);
882 	if (IS_ERR(tc)) {
883 		err = PTR_ERR(tc);
884 		tc = NULL;
885 		goto done;
886 	}
887 
888 	err = p9_client_rpc(clnt, tc, &rc);
889 
890 done:
891 	kfree(tc);
892 	kfree(rc);
893 	return err;
894 }
895 EXPORT_SYMBOL(p9_client_wstat);
896 
897 struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset)
898 {
899 	int err, n, m;
900 	struct p9_fcall *tc, *rc;
901 	struct p9_client *clnt;
902 	struct p9_stat st, *ret;
903 
904 	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu\n", fid->fid,
905 						(long long unsigned) offset);
906 	err = 0;
907 	tc = NULL;
908 	rc = NULL;
909 	ret = NULL;
910 	clnt = fid->clnt;
911 
912 	/* if the offset is below or above the current response, free it */
913 	if (offset < fid->rdir_fpos || (fid->rdir_fcall &&
914 		offset >= fid->rdir_fpos+fid->rdir_fcall->params.rread.count)) {
915 		fid->rdir_pos = 0;
916 		if (fid->rdir_fcall)
917 			fid->rdir_fpos += fid->rdir_fcall->params.rread.count;
918 
919 		kfree(fid->rdir_fcall);
920 		fid->rdir_fcall = NULL;
921 		if (offset < fid->rdir_fpos)
922 			fid->rdir_fpos = 0;
923 	}
924 
925 	if (!fid->rdir_fcall) {
926 		n = fid->iounit;
927 		if (!n || n > clnt->msize-P9_IOHDRSZ)
928 			n = clnt->msize - P9_IOHDRSZ;
929 
930 		while (1) {
931 			if (fid->rdir_fcall) {
932 				fid->rdir_fpos +=
933 					fid->rdir_fcall->params.rread.count;
934 				kfree(fid->rdir_fcall);
935 				fid->rdir_fcall = NULL;
936 			}
937 
938 			tc = p9_create_tread(fid->fid, fid->rdir_fpos, n);
939 			if (IS_ERR(tc)) {
940 				err = PTR_ERR(tc);
941 				tc = NULL;
942 				goto error;
943 			}
944 
945 			err = p9_client_rpc(clnt, tc, &rc);
946 			if (err)
947 				goto error;
948 
949 			n = rc->params.rread.count;
950 			if (n == 0)
951 				goto done;
952 
953 			fid->rdir_fcall = rc;
954 			rc = NULL;
955 			if (offset >= fid->rdir_fpos &&
956 						offset < fid->rdir_fpos+n)
957 				break;
958 		}
959 
960 		fid->rdir_pos = 0;
961 	}
962 
963 	m = offset - fid->rdir_fpos;
964 	if (m < 0)
965 		goto done;
966 
967 	n = p9_deserialize_stat(fid->rdir_fcall->params.rread.data + m,
968 		fid->rdir_fcall->params.rread.count - m, &st, clnt->dotu);
969 
970 	if (!n) {
971 		err = -EIO;
972 		goto error;
973 	}
974 
975 	fid->rdir_pos += n;
976 	st.size = n;
977 	ret = p9_clone_stat(&st, clnt->dotu);
978 	if (IS_ERR(ret)) {
979 		err = PTR_ERR(ret);
980 		ret = NULL;
981 		goto error;
982 	}
983 
984 done:
985 	kfree(tc);
986 	kfree(rc);
987 	return ret;
988 
989 error:
990 	kfree(tc);
991 	kfree(rc);
992 	kfree(ret);
993 	return ERR_PTR(err);
994 }
995 EXPORT_SYMBOL(p9_client_dirread);
996 
997 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu)
998 {
999 	int n;
1000 	char *p;
1001 	struct p9_stat *ret;
1002 
1003 	n = sizeof(struct p9_stat) + st->name.len + st->uid.len + st->gid.len +
1004 		st->muid.len;
1005 
1006 	if (dotu)
1007 		n += st->extension.len;
1008 
1009 	ret = kmalloc(n, GFP_KERNEL);
1010 	if (!ret)
1011 		return ERR_PTR(-ENOMEM);
1012 
1013 	memmove(ret, st, sizeof(struct p9_stat));
1014 	p = ((char *) ret) + sizeof(struct p9_stat);
1015 	memmove(p, st->name.str, st->name.len);
1016 	ret->name.str = p;
1017 	p += st->name.len;
1018 	memmove(p, st->uid.str, st->uid.len);
1019 	ret->uid.str = p;
1020 	p += st->uid.len;
1021 	memmove(p, st->gid.str, st->gid.len);
1022 	ret->gid.str = p;
1023 	p += st->gid.len;
1024 	memmove(p, st->muid.str, st->muid.len);
1025 	ret->muid.str = p;
1026 	p += st->muid.len;
1027 
1028 	if (dotu) {
1029 		memmove(p, st->extension.str, st->extension.len);
1030 		ret->extension.str = p;
1031 		p += st->extension.len;
1032 	}
1033 
1034 	return ret;
1035 }
1036 
1037 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
1038 {
1039 	int err;
1040 	struct p9_fid *fid;
1041 
1042 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
1043 	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
1044 	if (!fid)
1045 		return ERR_PTR(-ENOMEM);
1046 
1047 	fid->fid = p9_idpool_get(clnt->fidpool);
1048 	if (fid->fid < 0) {
1049 		err = -ENOSPC;
1050 		goto error;
1051 	}
1052 
1053 	memset(&fid->qid, 0, sizeof(struct p9_qid));
1054 	fid->mode = -1;
1055 	fid->rdir_fpos = 0;
1056 	fid->rdir_pos = 0;
1057 	fid->rdir_fcall = NULL;
1058 	fid->uid = current->fsuid;
1059 	fid->clnt = clnt;
1060 	fid->aux = NULL;
1061 
1062 	spin_lock(&clnt->lock);
1063 	list_add(&fid->flist, &clnt->fidlist);
1064 	spin_unlock(&clnt->lock);
1065 
1066 	return fid;
1067 
1068 error:
1069 	kfree(fid);
1070 	return ERR_PTR(err);
1071 }
1072 
1073 static void p9_fid_destroy(struct p9_fid *fid)
1074 {
1075 	struct p9_client *clnt;
1076 
1077 	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
1078 	clnt = fid->clnt;
1079 	p9_idpool_put(fid->fid, clnt->fidpool);
1080 	spin_lock(&clnt->lock);
1081 	list_del(&fid->flist);
1082 	spin_unlock(&clnt->lock);
1083 	kfree(fid->rdir_fcall);
1084 	kfree(fid);
1085 }
1086