Linux 3.8-rc7
[cris-mirror.git] / net / 9p / client.c
blob34d41767093500ba7cda60a2a1990ede456f35bd
1 /*
2 * net/9p/clnt.c
4 * 9P Client
6 * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
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.
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.
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
26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/fs.h>
31 #include <linux/poll.h>
32 #include <linux/idr.h>
33 #include <linux/mutex.h>
34 #include <linux/slab.h>
35 #include <linux/sched.h>
36 #include <linux/uaccess.h>
37 #include <net/9p/9p.h>
38 #include <linux/parser.h>
39 #include <net/9p/client.h>
40 #include <net/9p/transport.h>
41 #include "protocol.h"
43 #define CREATE_TRACE_POINTS
44 #include <trace/events/9p.h>
47 * Client Option Parsing (code inspired by NFS code)
48 * - a little lazy - parse all client options
51 enum {
52 Opt_msize,
53 Opt_trans,
54 Opt_legacy,
55 Opt_version,
56 Opt_err,
59 static const match_table_t tokens = {
60 {Opt_msize, "msize=%u"},
61 {Opt_legacy, "noextend"},
62 {Opt_trans, "trans=%s"},
63 {Opt_version, "version=%s"},
64 {Opt_err, NULL},
67 inline int p9_is_proto_dotl(struct p9_client *clnt)
69 return clnt->proto_version == p9_proto_2000L;
71 EXPORT_SYMBOL(p9_is_proto_dotl);
73 inline int p9_is_proto_dotu(struct p9_client *clnt)
75 return clnt->proto_version == p9_proto_2000u;
77 EXPORT_SYMBOL(p9_is_proto_dotu);
80 * Some error codes are taken directly from the server replies,
81 * make sure they are valid.
83 static int safe_errno(int err)
85 if ((err > 0) || (err < -MAX_ERRNO)) {
86 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
87 return -EPROTO;
89 return err;
93 /* Interpret mount option for protocol version */
94 static int get_protocol_version(char *s)
96 int version = -EINVAL;
98 if (!strcmp(s, "9p2000")) {
99 version = p9_proto_legacy;
100 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
101 } else if (!strcmp(s, "9p2000.u")) {
102 version = p9_proto_2000u;
103 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
104 } else if (!strcmp(s, "9p2000.L")) {
105 version = p9_proto_2000L;
106 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
107 } else
108 pr_info("Unknown protocol version %s\n", s);
110 return version;
114 * parse_options - parse mount options into client structure
115 * @opts: options string passed from mount
116 * @clnt: existing v9fs client information
118 * Return 0 upon success, -ERRNO upon failure
121 static int parse_opts(char *opts, struct p9_client *clnt)
123 char *options, *tmp_options;
124 char *p;
125 substring_t args[MAX_OPT_ARGS];
126 int option;
127 char *s;
128 int ret = 0;
130 clnt->proto_version = p9_proto_2000u;
131 clnt->msize = 8192;
133 if (!opts)
134 return 0;
136 tmp_options = kstrdup(opts, GFP_KERNEL);
137 if (!tmp_options) {
138 p9_debug(P9_DEBUG_ERROR,
139 "failed to allocate copy of option string\n");
140 return -ENOMEM;
142 options = tmp_options;
144 while ((p = strsep(&options, ",")) != NULL) {
145 int token, r;
146 if (!*p)
147 continue;
148 token = match_token(p, tokens, args);
149 switch (token) {
150 case Opt_msize:
151 r = match_int(&args[0], &option);
152 if (r < 0) {
153 p9_debug(P9_DEBUG_ERROR,
154 "integer field, but no integer?\n");
155 ret = r;
156 continue;
158 clnt->msize = option;
159 break;
160 case Opt_trans:
161 s = match_strdup(&args[0]);
162 if (!s) {
163 ret = -ENOMEM;
164 p9_debug(P9_DEBUG_ERROR,
165 "problem allocating copy of trans arg\n");
166 goto free_and_return;
168 clnt->trans_mod = v9fs_get_trans_by_name(s);
169 if (clnt->trans_mod == NULL) {
170 pr_info("Could not find request transport: %s\n",
172 ret = -EINVAL;
173 kfree(s);
174 goto free_and_return;
176 kfree(s);
177 break;
178 case Opt_legacy:
179 clnt->proto_version = p9_proto_legacy;
180 break;
181 case Opt_version:
182 s = match_strdup(&args[0]);
183 if (!s) {
184 ret = -ENOMEM;
185 p9_debug(P9_DEBUG_ERROR,
186 "problem allocating copy of version arg\n");
187 goto free_and_return;
189 ret = get_protocol_version(s);
190 if (ret == -EINVAL) {
191 kfree(s);
192 goto free_and_return;
194 kfree(s);
195 clnt->proto_version = ret;
196 break;
197 default:
198 continue;
202 free_and_return:
203 kfree(tmp_options);
204 return ret;
208 * p9_tag_alloc - lookup/allocate a request by tag
209 * @c: client session to lookup tag within
210 * @tag: numeric id for transaction
212 * this is a simple array lookup, but will grow the
213 * request_slots as necessary to accommodate transaction
214 * ids which did not previously have a slot.
216 * this code relies on the client spinlock to manage locks, its
217 * possible we should switch to something else, but I'd rather
218 * stick with something low-overhead for the common case.
222 static struct p9_req_t *
223 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
225 unsigned long flags;
226 int row, col;
227 struct p9_req_t *req;
228 int alloc_msize = min(c->msize, max_size);
230 /* This looks up the original request by tag so we know which
231 * buffer to read the data into */
232 tag++;
234 if (tag >= c->max_tag) {
235 spin_lock_irqsave(&c->lock, flags);
236 /* check again since original check was outside of lock */
237 while (tag >= c->max_tag) {
238 row = (tag / P9_ROW_MAXTAG);
239 c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
240 sizeof(struct p9_req_t), GFP_ATOMIC);
242 if (!c->reqs[row]) {
243 pr_err("Couldn't grow tag array\n");
244 spin_unlock_irqrestore(&c->lock, flags);
245 return ERR_PTR(-ENOMEM);
247 for (col = 0; col < P9_ROW_MAXTAG; col++) {
248 c->reqs[row][col].status = REQ_STATUS_IDLE;
249 c->reqs[row][col].tc = NULL;
251 c->max_tag += P9_ROW_MAXTAG;
253 spin_unlock_irqrestore(&c->lock, flags);
255 row = tag / P9_ROW_MAXTAG;
256 col = tag % P9_ROW_MAXTAG;
258 req = &c->reqs[row][col];
259 if (!req->tc) {
260 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
261 if (!req->wq) {
262 pr_err("Couldn't grow tag array\n");
263 return ERR_PTR(-ENOMEM);
265 init_waitqueue_head(req->wq);
266 req->tc = kmalloc(sizeof(struct p9_fcall) + alloc_msize,
267 GFP_NOFS);
268 req->rc = kmalloc(sizeof(struct p9_fcall) + alloc_msize,
269 GFP_NOFS);
270 if ((!req->tc) || (!req->rc)) {
271 pr_err("Couldn't grow tag array\n");
272 kfree(req->tc);
273 kfree(req->rc);
274 kfree(req->wq);
275 req->tc = req->rc = NULL;
276 req->wq = NULL;
277 return ERR_PTR(-ENOMEM);
279 req->tc->capacity = alloc_msize;
280 req->rc->capacity = alloc_msize;
281 req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
282 req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
285 p9pdu_reset(req->tc);
286 p9pdu_reset(req->rc);
288 req->tc->tag = tag-1;
289 req->status = REQ_STATUS_ALLOC;
291 return &c->reqs[row][col];
295 * p9_tag_lookup - lookup a request by tag
296 * @c: client session to lookup tag within
297 * @tag: numeric id for transaction
301 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
303 int row, col;
305 /* This looks up the original request by tag so we know which
306 * buffer to read the data into */
307 tag++;
309 if(tag >= c->max_tag)
310 return NULL;
312 row = tag / P9_ROW_MAXTAG;
313 col = tag % P9_ROW_MAXTAG;
315 return &c->reqs[row][col];
317 EXPORT_SYMBOL(p9_tag_lookup);
320 * p9_tag_init - setup tags structure and contents
321 * @c: v9fs client struct
323 * This initializes the tags structure for each client instance.
327 static int p9_tag_init(struct p9_client *c)
329 int err = 0;
331 c->tagpool = p9_idpool_create();
332 if (IS_ERR(c->tagpool)) {
333 err = PTR_ERR(c->tagpool);
334 goto error;
336 err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
337 if (err < 0) {
338 p9_idpool_destroy(c->tagpool);
339 goto error;
341 c->max_tag = 0;
342 error:
343 return err;
347 * p9_tag_cleanup - cleans up tags structure and reclaims resources
348 * @c: v9fs client struct
350 * This frees resources associated with the tags structure
353 static void p9_tag_cleanup(struct p9_client *c)
355 int row, col;
357 /* check to insure all requests are idle */
358 for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
359 for (col = 0; col < P9_ROW_MAXTAG; col++) {
360 if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
361 p9_debug(P9_DEBUG_MUX,
362 "Attempting to cleanup non-free tag %d,%d\n",
363 row, col);
364 /* TODO: delay execution of cleanup */
365 return;
370 if (c->tagpool) {
371 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
372 p9_idpool_destroy(c->tagpool);
375 /* free requests associated with tags */
376 for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
377 for (col = 0; col < P9_ROW_MAXTAG; col++) {
378 kfree(c->reqs[row][col].wq);
379 kfree(c->reqs[row][col].tc);
380 kfree(c->reqs[row][col].rc);
382 kfree(c->reqs[row]);
384 c->max_tag = 0;
388 * p9_free_req - free a request and clean-up as necessary
389 * c: client state
390 * r: request to release
394 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
396 int tag = r->tc->tag;
397 p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
399 r->status = REQ_STATUS_IDLE;
400 if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
401 p9_idpool_put(tag, c->tagpool);
405 * p9_client_cb - call back from transport to client
406 * c: client state
407 * req: request received
410 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
412 p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
413 wake_up(req->wq);
414 p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
416 EXPORT_SYMBOL(p9_client_cb);
419 * p9_parse_header - parse header arguments out of a packet
420 * @pdu: packet to parse
421 * @size: size of packet
422 * @type: type of request
423 * @tag: tag of packet
424 * @rewind: set if we need to rewind offset afterwards
428 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
429 int rewind)
431 int8_t r_type;
432 int16_t r_tag;
433 int32_t r_size;
434 int offset = pdu->offset;
435 int err;
437 pdu->offset = 0;
438 if (pdu->size == 0)
439 pdu->size = 7;
441 err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
442 if (err)
443 goto rewind_and_exit;
445 pdu->size = r_size;
446 pdu->id = r_type;
447 pdu->tag = r_tag;
449 p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
450 pdu->size, pdu->id, pdu->tag);
452 if (type)
453 *type = r_type;
454 if (tag)
455 *tag = r_tag;
456 if (size)
457 *size = r_size;
460 rewind_and_exit:
461 if (rewind)
462 pdu->offset = offset;
463 return err;
465 EXPORT_SYMBOL(p9_parse_header);
468 * p9_check_errors - check 9p packet for error return and process it
469 * @c: current client instance
470 * @req: request to parse and check for error conditions
472 * returns error code if one is discovered, otherwise returns 0
474 * this will have to be more complicated if we have multiple
475 * error packet types
478 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
480 int8_t type;
481 int err;
482 int ecode;
484 err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
486 * dump the response from server
487 * This should be after check errors which poplulate pdu_fcall.
489 trace_9p_protocol_dump(c, req->rc);
490 if (err) {
491 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
492 return err;
494 if (type != P9_RERROR && type != P9_RLERROR)
495 return 0;
497 if (!p9_is_proto_dotl(c)) {
498 char *ename;
499 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
500 &ename, &ecode);
501 if (err)
502 goto out_err;
504 if (p9_is_proto_dotu(c))
505 err = -ecode;
507 if (!err || !IS_ERR_VALUE(err)) {
508 err = p9_errstr2errno(ename, strlen(ename));
510 p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
511 -ecode, ename);
513 kfree(ename);
514 } else {
515 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
516 err = -ecode;
518 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
521 return err;
523 out_err:
524 p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
526 return err;
530 * p9_check_zc_errors - check 9p packet for error return and process it
531 * @c: current client instance
532 * @req: request to parse and check for error conditions
533 * @in_hdrlen: Size of response protocol buffer.
535 * returns error code if one is discovered, otherwise returns 0
537 * this will have to be more complicated if we have multiple
538 * error packet types
541 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
542 char *uidata, int in_hdrlen, int kern_buf)
544 int err;
545 int ecode;
546 int8_t type;
547 char *ename = NULL;
549 err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
551 * dump the response from server
552 * This should be after parse_header which poplulate pdu_fcall.
554 trace_9p_protocol_dump(c, req->rc);
555 if (err) {
556 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
557 return err;
560 if (type != P9_RERROR && type != P9_RLERROR)
561 return 0;
563 if (!p9_is_proto_dotl(c)) {
564 /* Error is reported in string format */
565 uint16_t len;
566 /* 7 = header size for RERROR, 2 is the size of string len; */
567 int inline_len = in_hdrlen - (7 + 2);
569 /* Read the size of error string */
570 err = p9pdu_readf(req->rc, c->proto_version, "w", &len);
571 if (err)
572 goto out_err;
574 ename = kmalloc(len + 1, GFP_NOFS);
575 if (!ename) {
576 err = -ENOMEM;
577 goto out_err;
579 if (len <= inline_len) {
580 /* We have error in protocol buffer itself */
581 if (pdu_read(req->rc, ename, len)) {
582 err = -EFAULT;
583 goto out_free;
586 } else {
588 * Part of the data is in user space buffer.
590 if (pdu_read(req->rc, ename, inline_len)) {
591 err = -EFAULT;
592 goto out_free;
595 if (kern_buf) {
596 memcpy(ename + inline_len, uidata,
597 len - inline_len);
598 } else {
599 err = copy_from_user(ename + inline_len,
600 uidata, len - inline_len);
601 if (err) {
602 err = -EFAULT;
603 goto out_free;
607 ename[len] = 0;
608 if (p9_is_proto_dotu(c)) {
609 /* For dotu we also have error code */
610 err = p9pdu_readf(req->rc,
611 c->proto_version, "d", &ecode);
612 if (err)
613 goto out_free;
614 err = -ecode;
616 if (!err || !IS_ERR_VALUE(err)) {
617 err = p9_errstr2errno(ename, strlen(ename));
619 p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
620 -ecode, ename);
622 kfree(ename);
623 } else {
624 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
625 err = -ecode;
627 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
629 return err;
631 out_free:
632 kfree(ename);
633 out_err:
634 p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
635 return err;
638 static struct p9_req_t *
639 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
642 * p9_client_flush - flush (cancel) a request
643 * @c: client state
644 * @oldreq: request to cancel
646 * This sents a flush for a particular request and links
647 * the flush request to the original request. The current
648 * code only supports a single flush request although the protocol
649 * allows for multiple flush requests to be sent for a single request.
653 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
655 struct p9_req_t *req;
656 int16_t oldtag;
657 int err;
659 err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
660 if (err)
661 return err;
663 p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
665 req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
666 if (IS_ERR(req))
667 return PTR_ERR(req);
670 /* if we haven't received a response for oldreq,
671 remove it from the list. */
672 spin_lock(&c->lock);
673 if (oldreq->status == REQ_STATUS_FLSH)
674 list_del(&oldreq->req_list);
675 spin_unlock(&c->lock);
677 p9_free_req(c, req);
678 return 0;
681 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
682 int8_t type, int req_size,
683 const char *fmt, va_list ap)
685 int tag, err;
686 struct p9_req_t *req;
688 p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
690 /* we allow for any status other than disconnected */
691 if (c->status == Disconnected)
692 return ERR_PTR(-EIO);
694 /* if status is begin_disconnected we allow only clunk request */
695 if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
696 return ERR_PTR(-EIO);
698 tag = P9_NOTAG;
699 if (type != P9_TVERSION) {
700 tag = p9_idpool_get(c->tagpool);
701 if (tag < 0)
702 return ERR_PTR(-ENOMEM);
705 req = p9_tag_alloc(c, tag, req_size);
706 if (IS_ERR(req))
707 return req;
709 /* marshall the data */
710 p9pdu_prepare(req->tc, tag, type);
711 err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
712 if (err)
713 goto reterr;
714 p9pdu_finalize(c, req->tc);
715 trace_9p_client_req(c, type, tag);
716 return req;
717 reterr:
718 p9_free_req(c, req);
719 return ERR_PTR(err);
723 * p9_client_rpc - issue a request and wait for a response
724 * @c: client session
725 * @type: type of request
726 * @fmt: protocol format string (see protocol.c)
728 * Returns request structure (which client must free using p9_free_req)
731 static struct p9_req_t *
732 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
734 va_list ap;
735 int sigpending, err;
736 unsigned long flags;
737 struct p9_req_t *req;
739 va_start(ap, fmt);
740 req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
741 va_end(ap);
742 if (IS_ERR(req))
743 return req;
745 if (signal_pending(current)) {
746 sigpending = 1;
747 clear_thread_flag(TIF_SIGPENDING);
748 } else
749 sigpending = 0;
751 err = c->trans_mod->request(c, req);
752 if (err < 0) {
753 if (err != -ERESTARTSYS && err != -EFAULT)
754 c->status = Disconnected;
755 goto reterr;
757 again:
758 /* Wait for the response */
759 err = wait_event_interruptible(*req->wq,
760 req->status >= REQ_STATUS_RCVD);
762 if ((err == -ERESTARTSYS) && (c->status == Connected)
763 && (type == P9_TFLUSH)) {
764 sigpending = 1;
765 clear_thread_flag(TIF_SIGPENDING);
766 goto again;
769 if (req->status == REQ_STATUS_ERROR) {
770 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
771 err = req->t_err;
773 if ((err == -ERESTARTSYS) && (c->status == Connected)) {
774 p9_debug(P9_DEBUG_MUX, "flushing\n");
775 sigpending = 1;
776 clear_thread_flag(TIF_SIGPENDING);
778 if (c->trans_mod->cancel(c, req))
779 p9_client_flush(c, req);
781 /* if we received the response anyway, don't signal error */
782 if (req->status == REQ_STATUS_RCVD)
783 err = 0;
785 if (sigpending) {
786 spin_lock_irqsave(&current->sighand->siglock, flags);
787 recalc_sigpending();
788 spin_unlock_irqrestore(&current->sighand->siglock, flags);
790 if (err < 0)
791 goto reterr;
793 err = p9_check_errors(c, req);
794 trace_9p_client_res(c, type, req->rc->tag, err);
795 if (!err)
796 return req;
797 reterr:
798 p9_free_req(c, req);
799 return ERR_PTR(safe_errno(err));
803 * p9_client_zc_rpc - issue a request and wait for a response
804 * @c: client session
805 * @type: type of request
806 * @uidata: user bffer that should be ued for zero copy read
807 * @uodata: user buffer that shoud be user for zero copy write
808 * @inlen: read buffer size
809 * @olen: write buffer size
810 * @hdrlen: reader header size, This is the size of response protocol data
811 * @fmt: protocol format string (see protocol.c)
813 * Returns request structure (which client must free using p9_free_req)
815 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
816 char *uidata, char *uodata,
817 int inlen, int olen, int in_hdrlen,
818 int kern_buf, const char *fmt, ...)
820 va_list ap;
821 int sigpending, err;
822 unsigned long flags;
823 struct p9_req_t *req;
825 va_start(ap, fmt);
827 * We allocate a inline protocol data of only 4k bytes.
828 * The actual content is passed in zero-copy fashion.
830 req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
831 va_end(ap);
832 if (IS_ERR(req))
833 return req;
835 if (signal_pending(current)) {
836 sigpending = 1;
837 clear_thread_flag(TIF_SIGPENDING);
838 } else
839 sigpending = 0;
841 /* If we are called with KERNEL_DS force kern_buf */
842 if (segment_eq(get_fs(), KERNEL_DS))
843 kern_buf = 1;
845 err = c->trans_mod->zc_request(c, req, uidata, uodata,
846 inlen, olen, in_hdrlen, kern_buf);
847 if (err < 0) {
848 if (err == -EIO)
849 c->status = Disconnected;
850 goto reterr;
852 if (req->status == REQ_STATUS_ERROR) {
853 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
854 err = req->t_err;
856 if ((err == -ERESTARTSYS) && (c->status == Connected)) {
857 p9_debug(P9_DEBUG_MUX, "flushing\n");
858 sigpending = 1;
859 clear_thread_flag(TIF_SIGPENDING);
861 if (c->trans_mod->cancel(c, req))
862 p9_client_flush(c, req);
864 /* if we received the response anyway, don't signal error */
865 if (req->status == REQ_STATUS_RCVD)
866 err = 0;
868 if (sigpending) {
869 spin_lock_irqsave(&current->sighand->siglock, flags);
870 recalc_sigpending();
871 spin_unlock_irqrestore(&current->sighand->siglock, flags);
873 if (err < 0)
874 goto reterr;
876 err = p9_check_zc_errors(c, req, uidata, in_hdrlen, kern_buf);
877 trace_9p_client_res(c, type, req->rc->tag, err);
878 if (!err)
879 return req;
880 reterr:
881 p9_free_req(c, req);
882 return ERR_PTR(safe_errno(err));
885 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
887 int ret;
888 struct p9_fid *fid;
889 unsigned long flags;
891 p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
892 fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
893 if (!fid)
894 return ERR_PTR(-ENOMEM);
896 ret = p9_idpool_get(clnt->fidpool);
897 if (ret < 0) {
898 ret = -ENOSPC;
899 goto error;
901 fid->fid = ret;
903 memset(&fid->qid, 0, sizeof(struct p9_qid));
904 fid->mode = -1;
905 fid->uid = current_fsuid();
906 fid->clnt = clnt;
907 fid->rdir = NULL;
908 spin_lock_irqsave(&clnt->lock, flags);
909 list_add(&fid->flist, &clnt->fidlist);
910 spin_unlock_irqrestore(&clnt->lock, flags);
912 return fid;
914 error:
915 kfree(fid);
916 return ERR_PTR(ret);
919 static void p9_fid_destroy(struct p9_fid *fid)
921 struct p9_client *clnt;
922 unsigned long flags;
924 p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
925 clnt = fid->clnt;
926 p9_idpool_put(fid->fid, clnt->fidpool);
927 spin_lock_irqsave(&clnt->lock, flags);
928 list_del(&fid->flist);
929 spin_unlock_irqrestore(&clnt->lock, flags);
930 kfree(fid->rdir);
931 kfree(fid);
934 static int p9_client_version(struct p9_client *c)
936 int err = 0;
937 struct p9_req_t *req;
938 char *version;
939 int msize;
941 p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
942 c->msize, c->proto_version);
944 switch (c->proto_version) {
945 case p9_proto_2000L:
946 req = p9_client_rpc(c, P9_TVERSION, "ds",
947 c->msize, "9P2000.L");
948 break;
949 case p9_proto_2000u:
950 req = p9_client_rpc(c, P9_TVERSION, "ds",
951 c->msize, "9P2000.u");
952 break;
953 case p9_proto_legacy:
954 req = p9_client_rpc(c, P9_TVERSION, "ds",
955 c->msize, "9P2000");
956 break;
957 default:
958 return -EINVAL;
959 break;
962 if (IS_ERR(req))
963 return PTR_ERR(req);
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;
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 err = -EREMOTEIO;
981 goto error;
984 if (msize < c->msize)
985 c->msize = msize;
987 error:
988 kfree(version);
989 p9_free_req(c, req);
991 return err;
994 struct p9_client *p9_client_create(const char *dev_name, char *options)
996 int err;
997 struct p9_client *clnt;
999 err = 0;
1000 clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1001 if (!clnt)
1002 return ERR_PTR(-ENOMEM);
1004 clnt->trans_mod = NULL;
1005 clnt->trans = NULL;
1006 spin_lock_init(&clnt->lock);
1007 INIT_LIST_HEAD(&clnt->fidlist);
1009 err = p9_tag_init(clnt);
1010 if (err < 0)
1011 goto free_client;
1013 err = parse_opts(options, clnt);
1014 if (err < 0)
1015 goto destroy_tagpool;
1017 if (!clnt->trans_mod)
1018 clnt->trans_mod = v9fs_get_default_trans();
1020 if (clnt->trans_mod == NULL) {
1021 err = -EPROTONOSUPPORT;
1022 p9_debug(P9_DEBUG_ERROR,
1023 "No transport defined or default transport\n");
1024 goto destroy_tagpool;
1027 clnt->fidpool = p9_idpool_create();
1028 if (IS_ERR(clnt->fidpool)) {
1029 err = PTR_ERR(clnt->fidpool);
1030 goto put_trans;
1033 p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1034 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1036 err = clnt->trans_mod->create(clnt, dev_name, options);
1037 if (err)
1038 goto destroy_fidpool;
1040 if (clnt->msize > clnt->trans_mod->maxsize)
1041 clnt->msize = clnt->trans_mod->maxsize;
1043 err = p9_client_version(clnt);
1044 if (err)
1045 goto close_trans;
1047 return clnt;
1049 close_trans:
1050 clnt->trans_mod->close(clnt);
1051 destroy_fidpool:
1052 p9_idpool_destroy(clnt->fidpool);
1053 put_trans:
1054 v9fs_put_trans(clnt->trans_mod);
1055 destroy_tagpool:
1056 p9_idpool_destroy(clnt->tagpool);
1057 free_client:
1058 kfree(clnt);
1059 return ERR_PTR(err);
1061 EXPORT_SYMBOL(p9_client_create);
1063 void p9_client_destroy(struct p9_client *clnt)
1065 struct p9_fid *fid, *fidptr;
1067 p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1069 if (clnt->trans_mod)
1070 clnt->trans_mod->close(clnt);
1072 v9fs_put_trans(clnt->trans_mod);
1074 list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1075 pr_info("Found fid %d not clunked\n", fid->fid);
1076 p9_fid_destroy(fid);
1079 if (clnt->fidpool)
1080 p9_idpool_destroy(clnt->fidpool);
1082 p9_tag_cleanup(clnt);
1084 kfree(clnt);
1086 EXPORT_SYMBOL(p9_client_destroy);
1088 void p9_client_disconnect(struct p9_client *clnt)
1090 p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1091 clnt->status = Disconnected;
1093 EXPORT_SYMBOL(p9_client_disconnect);
1095 void p9_client_begin_disconnect(struct p9_client *clnt)
1097 p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1098 clnt->status = BeginDisconnect;
1100 EXPORT_SYMBOL(p9_client_begin_disconnect);
1102 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1103 char *uname, u32 n_uname, char *aname)
1105 int err = 0;
1106 struct p9_req_t *req;
1107 struct p9_fid *fid;
1108 struct p9_qid qid;
1111 p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1112 afid ? afid->fid : -1, uname, aname);
1113 fid = p9_fid_create(clnt);
1114 if (IS_ERR(fid)) {
1115 err = PTR_ERR(fid);
1116 fid = NULL;
1117 goto error;
1120 req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
1121 afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1122 if (IS_ERR(req)) {
1123 err = PTR_ERR(req);
1124 goto error;
1127 err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1128 if (err) {
1129 trace_9p_protocol_dump(clnt, req->rc);
1130 p9_free_req(clnt, req);
1131 goto error;
1134 p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1135 qid.type, (unsigned long long)qid.path, qid.version);
1137 memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1139 p9_free_req(clnt, req);
1140 return fid;
1142 error:
1143 if (fid)
1144 p9_fid_destroy(fid);
1145 return ERR_PTR(err);
1147 EXPORT_SYMBOL(p9_client_attach);
1149 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1150 char **wnames, int clone)
1152 int err;
1153 struct p9_client *clnt;
1154 struct p9_fid *fid;
1155 struct p9_qid *wqids;
1156 struct p9_req_t *req;
1157 uint16_t nwqids, count;
1159 err = 0;
1160 wqids = NULL;
1161 clnt = oldfid->clnt;
1162 if (clone) {
1163 fid = p9_fid_create(clnt);
1164 if (IS_ERR(fid)) {
1165 err = PTR_ERR(fid);
1166 fid = NULL;
1167 goto error;
1170 fid->uid = oldfid->uid;
1171 } else
1172 fid = oldfid;
1175 p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1176 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1178 req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1179 nwname, wnames);
1180 if (IS_ERR(req)) {
1181 err = PTR_ERR(req);
1182 goto error;
1185 err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1186 if (err) {
1187 trace_9p_protocol_dump(clnt, req->rc);
1188 p9_free_req(clnt, req);
1189 goto clunk_fid;
1191 p9_free_req(clnt, req);
1193 p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1195 if (nwqids != nwname) {
1196 err = -ENOENT;
1197 goto clunk_fid;
1200 for (count = 0; count < nwqids; count++)
1201 p9_debug(P9_DEBUG_9P, "<<< [%d] %x.%llx.%x\n",
1202 count, wqids[count].type,
1203 (unsigned long long)wqids[count].path,
1204 wqids[count].version);
1206 if (nwname)
1207 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1208 else
1209 fid->qid = oldfid->qid;
1211 kfree(wqids);
1212 return fid;
1214 clunk_fid:
1215 kfree(wqids);
1216 p9_client_clunk(fid);
1217 fid = NULL;
1219 error:
1220 if (fid && (fid != oldfid))
1221 p9_fid_destroy(fid);
1223 return ERR_PTR(err);
1225 EXPORT_SYMBOL(p9_client_walk);
1227 int p9_client_open(struct p9_fid *fid, int mode)
1229 int err;
1230 struct p9_client *clnt;
1231 struct p9_req_t *req;
1232 struct p9_qid qid;
1233 int iounit;
1235 clnt = fid->clnt;
1236 p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1237 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1238 err = 0;
1240 if (fid->mode != -1)
1241 return -EINVAL;
1243 if (p9_is_proto_dotl(clnt))
1244 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1245 else
1246 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1247 if (IS_ERR(req)) {
1248 err = PTR_ERR(req);
1249 goto error;
1252 err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1253 if (err) {
1254 trace_9p_protocol_dump(clnt, req->rc);
1255 goto free_and_error;
1258 p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1259 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN", qid.type,
1260 (unsigned long long)qid.path, qid.version, iounit);
1262 fid->mode = mode;
1263 fid->iounit = iounit;
1265 free_and_error:
1266 p9_free_req(clnt, req);
1267 error:
1268 return err;
1270 EXPORT_SYMBOL(p9_client_open);
1272 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1273 gid_t gid, struct p9_qid *qid)
1275 int err = 0;
1276 struct p9_client *clnt;
1277 struct p9_req_t *req;
1278 int iounit;
1280 p9_debug(P9_DEBUG_9P,
1281 ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1282 ofid->fid, name, flags, mode, gid);
1283 clnt = ofid->clnt;
1285 if (ofid->mode != -1)
1286 return -EINVAL;
1288 req = p9_client_rpc(clnt, P9_TLCREATE, "dsddd", ofid->fid, name, flags,
1289 mode, gid);
1290 if (IS_ERR(req)) {
1291 err = PTR_ERR(req);
1292 goto error;
1295 err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1296 if (err) {
1297 trace_9p_protocol_dump(clnt, req->rc);
1298 goto free_and_error;
1301 p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1302 qid->type,
1303 (unsigned long long)qid->path,
1304 qid->version, iounit);
1306 ofid->mode = mode;
1307 ofid->iounit = iounit;
1309 free_and_error:
1310 p9_free_req(clnt, req);
1311 error:
1312 return err;
1314 EXPORT_SYMBOL(p9_client_create_dotl);
1316 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1317 char *extension)
1319 int err;
1320 struct p9_client *clnt;
1321 struct p9_req_t *req;
1322 struct p9_qid qid;
1323 int iounit;
1325 p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1326 fid->fid, name, perm, mode);
1327 err = 0;
1328 clnt = fid->clnt;
1330 if (fid->mode != -1)
1331 return -EINVAL;
1333 req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1334 mode, extension);
1335 if (IS_ERR(req)) {
1336 err = PTR_ERR(req);
1337 goto error;
1340 err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1341 if (err) {
1342 trace_9p_protocol_dump(clnt, req->rc);
1343 goto free_and_error;
1346 p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1347 qid.type,
1348 (unsigned long long)qid.path,
1349 qid.version, iounit);
1351 fid->mode = mode;
1352 fid->iounit = iounit;
1354 free_and_error:
1355 p9_free_req(clnt, req);
1356 error:
1357 return err;
1359 EXPORT_SYMBOL(p9_client_fcreate);
1361 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
1362 struct p9_qid *qid)
1364 int err = 0;
1365 struct p9_client *clnt;
1366 struct p9_req_t *req;
1368 p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s symtgt %s\n",
1369 dfid->fid, name, symtgt);
1370 clnt = dfid->clnt;
1372 req = p9_client_rpc(clnt, P9_TSYMLINK, "dssd", dfid->fid, name, symtgt,
1373 gid);
1374 if (IS_ERR(req)) {
1375 err = PTR_ERR(req);
1376 goto error;
1379 err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1380 if (err) {
1381 trace_9p_protocol_dump(clnt, req->rc);
1382 goto free_and_error;
1385 p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1386 qid->type, (unsigned long long)qid->path, qid->version);
1388 free_and_error:
1389 p9_free_req(clnt, req);
1390 error:
1391 return err;
1393 EXPORT_SYMBOL(p9_client_symlink);
1395 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1397 struct p9_client *clnt;
1398 struct p9_req_t *req;
1400 p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1401 dfid->fid, oldfid->fid, newname);
1402 clnt = dfid->clnt;
1403 req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1404 newname);
1405 if (IS_ERR(req))
1406 return PTR_ERR(req);
1408 p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1409 p9_free_req(clnt, req);
1410 return 0;
1412 EXPORT_SYMBOL(p9_client_link);
1414 int p9_client_fsync(struct p9_fid *fid, int datasync)
1416 int err;
1417 struct p9_client *clnt;
1418 struct p9_req_t *req;
1420 p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1421 fid->fid, datasync);
1422 err = 0;
1423 clnt = fid->clnt;
1425 req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1426 if (IS_ERR(req)) {
1427 err = PTR_ERR(req);
1428 goto error;
1431 p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1433 p9_free_req(clnt, req);
1435 error:
1436 return err;
1438 EXPORT_SYMBOL(p9_client_fsync);
1440 int p9_client_clunk(struct p9_fid *fid)
1442 int err;
1443 struct p9_client *clnt;
1444 struct p9_req_t *req;
1445 int retries = 0;
1447 if (!fid) {
1448 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1449 __func__, task_pid_nr(current));
1450 dump_stack();
1451 return 0;
1454 again:
1455 p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1456 retries);
1457 err = 0;
1458 clnt = fid->clnt;
1460 req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1461 if (IS_ERR(req)) {
1462 err = PTR_ERR(req);
1463 goto error;
1466 p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1468 p9_free_req(clnt, req);
1469 error:
1471 * Fid is not valid even after a failed clunk
1472 * If interrupted, retry once then give up and
1473 * leak fid until umount.
1475 if (err == -ERESTARTSYS) {
1476 if (retries++ == 0)
1477 goto again;
1478 } else
1479 p9_fid_destroy(fid);
1480 return err;
1482 EXPORT_SYMBOL(p9_client_clunk);
1484 int p9_client_remove(struct p9_fid *fid)
1486 int err;
1487 struct p9_client *clnt;
1488 struct p9_req_t *req;
1490 p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1491 err = 0;
1492 clnt = fid->clnt;
1494 req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1495 if (IS_ERR(req)) {
1496 err = PTR_ERR(req);
1497 goto error;
1500 p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1502 p9_free_req(clnt, req);
1503 error:
1504 if (err == -ERESTARTSYS)
1505 p9_client_clunk(fid);
1506 else
1507 p9_fid_destroy(fid);
1508 return err;
1510 EXPORT_SYMBOL(p9_client_remove);
1512 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1514 int err = 0;
1515 struct p9_req_t *req;
1516 struct p9_client *clnt;
1518 p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1519 dfid->fid, name, flags);
1521 clnt = dfid->clnt;
1522 req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1523 if (IS_ERR(req)) {
1524 err = PTR_ERR(req);
1525 goto error;
1527 p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1529 p9_free_req(clnt, req);
1530 error:
1531 return err;
1533 EXPORT_SYMBOL(p9_client_unlinkat);
1536 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1537 u32 count)
1539 char *dataptr;
1540 int kernel_buf = 0;
1541 struct p9_req_t *req;
1542 struct p9_client *clnt;
1543 int err, rsize, non_zc = 0;
1546 p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1547 fid->fid, (unsigned long long) offset, count);
1548 err = 0;
1549 clnt = fid->clnt;
1551 rsize = fid->iounit;
1552 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1553 rsize = clnt->msize - P9_IOHDRSZ;
1555 if (count < rsize)
1556 rsize = count;
1558 /* Don't bother zerocopy for small IO (< 1024) */
1559 if (clnt->trans_mod->zc_request && rsize > 1024) {
1560 char *indata;
1561 if (data) {
1562 kernel_buf = 1;
1563 indata = data;
1564 } else
1565 indata = (__force char *)udata;
1567 * response header len is 11
1568 * PDU Header(7) + IO Size (4)
1570 req = p9_client_zc_rpc(clnt, P9_TREAD, indata, NULL, rsize, 0,
1571 11, kernel_buf, "dqd", fid->fid,
1572 offset, rsize);
1573 } else {
1574 non_zc = 1;
1575 req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1576 rsize);
1578 if (IS_ERR(req)) {
1579 err = PTR_ERR(req);
1580 goto error;
1583 err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1584 if (err) {
1585 trace_9p_protocol_dump(clnt, req->rc);
1586 goto free_and_error;
1589 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1591 if (non_zc) {
1592 if (data) {
1593 memmove(data, dataptr, count);
1594 } else {
1595 err = copy_to_user(udata, dataptr, count);
1596 if (err) {
1597 err = -EFAULT;
1598 goto free_and_error;
1602 p9_free_req(clnt, req);
1603 return count;
1605 free_and_error:
1606 p9_free_req(clnt, req);
1607 error:
1608 return err;
1610 EXPORT_SYMBOL(p9_client_read);
1613 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1614 u64 offset, u32 count)
1616 int err, rsize;
1617 int kernel_buf = 0;
1618 struct p9_client *clnt;
1619 struct p9_req_t *req;
1621 p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1622 fid->fid, (unsigned long long) offset, count);
1623 err = 0;
1624 clnt = fid->clnt;
1626 rsize = fid->iounit;
1627 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1628 rsize = clnt->msize - P9_IOHDRSZ;
1630 if (count < rsize)
1631 rsize = count;
1633 /* Don't bother zerocopy for small IO (< 1024) */
1634 if (clnt->trans_mod->zc_request && rsize > 1024) {
1635 char *odata;
1636 if (data) {
1637 kernel_buf = 1;
1638 odata = data;
1639 } else
1640 odata = (char *)udata;
1641 req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, odata, 0, rsize,
1642 P9_ZC_HDR_SZ, kernel_buf, "dqd",
1643 fid->fid, offset, rsize);
1644 } else {
1645 if (data)
1646 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1647 offset, rsize, data);
1648 else
1649 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1650 offset, rsize, udata);
1652 if (IS_ERR(req)) {
1653 err = PTR_ERR(req);
1654 goto error;
1657 err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1658 if (err) {
1659 trace_9p_protocol_dump(clnt, req->rc);
1660 goto free_and_error;
1663 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1665 p9_free_req(clnt, req);
1666 return count;
1668 free_and_error:
1669 p9_free_req(clnt, req);
1670 error:
1671 return err;
1673 EXPORT_SYMBOL(p9_client_write);
1675 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1677 int err;
1678 struct p9_client *clnt;
1679 struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1680 struct p9_req_t *req;
1681 u16 ignored;
1683 p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1685 if (!ret)
1686 return ERR_PTR(-ENOMEM);
1688 err = 0;
1689 clnt = fid->clnt;
1691 req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1692 if (IS_ERR(req)) {
1693 err = PTR_ERR(req);
1694 goto error;
1697 err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1698 if (err) {
1699 trace_9p_protocol_dump(clnt, req->rc);
1700 p9_free_req(clnt, req);
1701 goto error;
1704 p9_debug(P9_DEBUG_9P,
1705 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1706 "<<< mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1707 "<<< name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1708 "<<< uid=%d gid=%d n_muid=%d\n",
1709 ret->size, ret->type, ret->dev, ret->qid.type,
1710 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1711 ret->atime, ret->mtime, (unsigned long long)ret->length,
1712 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1713 ret->n_uid, ret->n_gid, ret->n_muid);
1715 p9_free_req(clnt, req);
1716 return ret;
1718 error:
1719 kfree(ret);
1720 return ERR_PTR(err);
1722 EXPORT_SYMBOL(p9_client_stat);
1724 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1725 u64 request_mask)
1727 int err;
1728 struct p9_client *clnt;
1729 struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1730 GFP_KERNEL);
1731 struct p9_req_t *req;
1733 p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1734 fid->fid, request_mask);
1736 if (!ret)
1737 return ERR_PTR(-ENOMEM);
1739 err = 0;
1740 clnt = fid->clnt;
1742 req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1743 if (IS_ERR(req)) {
1744 err = PTR_ERR(req);
1745 goto error;
1748 err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1749 if (err) {
1750 trace_9p_protocol_dump(clnt, req->rc);
1751 p9_free_req(clnt, req);
1752 goto error;
1755 p9_debug(P9_DEBUG_9P,
1756 "<<< RGETATTR st_result_mask=%lld\n"
1757 "<<< qid=%x.%llx.%x\n"
1758 "<<< st_mode=%8.8x st_nlink=%llu\n"
1759 "<<< st_uid=%d st_gid=%d\n"
1760 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1761 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1762 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1763 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1764 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1765 "<<< st_gen=%lld st_data_version=%lld",
1766 ret->st_result_mask, ret->qid.type, ret->qid.path,
1767 ret->qid.version, ret->st_mode, ret->st_nlink, ret->st_uid,
1768 ret->st_gid, ret->st_rdev, ret->st_size, ret->st_blksize,
1769 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1770 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1771 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1772 ret->st_gen, ret->st_data_version);
1774 p9_free_req(clnt, req);
1775 return ret;
1777 error:
1778 kfree(ret);
1779 return ERR_PTR(err);
1781 EXPORT_SYMBOL(p9_client_getattr_dotl);
1783 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1785 int ret;
1787 /* NOTE: size shouldn't include its own length */
1788 /* size[2] type[2] dev[4] qid[13] */
1789 /* mode[4] atime[4] mtime[4] length[8]*/
1790 /* name[s] uid[s] gid[s] muid[s] */
1791 ret = 2+4+13+4+4+4+8+2+2+2+2;
1793 if (wst->name)
1794 ret += strlen(wst->name);
1795 if (wst->uid)
1796 ret += strlen(wst->uid);
1797 if (wst->gid)
1798 ret += strlen(wst->gid);
1799 if (wst->muid)
1800 ret += strlen(wst->muid);
1802 if ((proto_version == p9_proto_2000u) ||
1803 (proto_version == p9_proto_2000L)) {
1804 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1805 if (wst->extension)
1806 ret += strlen(wst->extension);
1809 return ret;
1812 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1814 int err;
1815 struct p9_req_t *req;
1816 struct p9_client *clnt;
1818 err = 0;
1819 clnt = fid->clnt;
1820 wst->size = p9_client_statsize(wst, clnt->proto_version);
1821 p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1822 p9_debug(P9_DEBUG_9P,
1823 " sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1824 " mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1825 " name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1826 " uid=%d gid=%d n_muid=%d\n",
1827 wst->size, wst->type, wst->dev, wst->qid.type,
1828 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1829 wst->atime, wst->mtime, (unsigned long long)wst->length,
1830 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1831 wst->n_uid, wst->n_gid, wst->n_muid);
1833 req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1834 if (IS_ERR(req)) {
1835 err = PTR_ERR(req);
1836 goto error;
1839 p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1841 p9_free_req(clnt, req);
1842 error:
1843 return err;
1845 EXPORT_SYMBOL(p9_client_wstat);
1847 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1849 int err;
1850 struct p9_req_t *req;
1851 struct p9_client *clnt;
1853 err = 0;
1854 clnt = fid->clnt;
1855 p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1856 p9_debug(P9_DEBUG_9P,
1857 " valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1858 " atime_sec=%lld atime_nsec=%lld\n"
1859 " mtime_sec=%lld mtime_nsec=%lld\n",
1860 p9attr->valid, p9attr->mode, p9attr->uid, p9attr->gid,
1861 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1862 p9attr->mtime_sec, p9attr->mtime_nsec);
1864 req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1866 if (IS_ERR(req)) {
1867 err = PTR_ERR(req);
1868 goto error;
1870 p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1871 p9_free_req(clnt, req);
1872 error:
1873 return err;
1875 EXPORT_SYMBOL(p9_client_setattr);
1877 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1879 int err;
1880 struct p9_req_t *req;
1881 struct p9_client *clnt;
1883 err = 0;
1884 clnt = fid->clnt;
1886 p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1888 req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1889 if (IS_ERR(req)) {
1890 err = PTR_ERR(req);
1891 goto error;
1894 err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1895 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1896 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1897 if (err) {
1898 trace_9p_protocol_dump(clnt, req->rc);
1899 p9_free_req(clnt, req);
1900 goto error;
1903 p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1904 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1905 "fsid %llu namelen %ld\n",
1906 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1907 sb->blocks, sb->bfree, sb->bavail, sb->files, sb->ffree,
1908 sb->fsid, (long int)sb->namelen);
1910 p9_free_req(clnt, req);
1911 error:
1912 return err;
1914 EXPORT_SYMBOL(p9_client_statfs);
1916 int p9_client_rename(struct p9_fid *fid,
1917 struct p9_fid *newdirfid, const char *name)
1919 int err;
1920 struct p9_req_t *req;
1921 struct p9_client *clnt;
1923 err = 0;
1924 clnt = fid->clnt;
1926 p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1927 fid->fid, newdirfid->fid, name);
1929 req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1930 newdirfid->fid, name);
1931 if (IS_ERR(req)) {
1932 err = PTR_ERR(req);
1933 goto error;
1936 p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1938 p9_free_req(clnt, req);
1939 error:
1940 return err;
1942 EXPORT_SYMBOL(p9_client_rename);
1944 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1945 struct p9_fid *newdirfid, const char *new_name)
1947 int err;
1948 struct p9_req_t *req;
1949 struct p9_client *clnt;
1951 err = 0;
1952 clnt = olddirfid->clnt;
1954 p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1955 " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1956 newdirfid->fid, new_name);
1958 req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1959 old_name, newdirfid->fid, new_name);
1960 if (IS_ERR(req)) {
1961 err = PTR_ERR(req);
1962 goto error;
1965 p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1966 newdirfid->fid, new_name);
1968 p9_free_req(clnt, req);
1969 error:
1970 return err;
1972 EXPORT_SYMBOL(p9_client_renameat);
1975 * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1977 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1978 const char *attr_name, u64 *attr_size)
1980 int err;
1981 struct p9_req_t *req;
1982 struct p9_client *clnt;
1983 struct p9_fid *attr_fid;
1985 err = 0;
1986 clnt = file_fid->clnt;
1987 attr_fid = p9_fid_create(clnt);
1988 if (IS_ERR(attr_fid)) {
1989 err = PTR_ERR(attr_fid);
1990 attr_fid = NULL;
1991 goto error;
1993 p9_debug(P9_DEBUG_9P,
1994 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1995 file_fid->fid, attr_fid->fid, attr_name);
1997 req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1998 file_fid->fid, attr_fid->fid, attr_name);
1999 if (IS_ERR(req)) {
2000 err = PTR_ERR(req);
2001 goto error;
2003 err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2004 if (err) {
2005 trace_9p_protocol_dump(clnt, req->rc);
2006 p9_free_req(clnt, req);
2007 goto clunk_fid;
2009 p9_free_req(clnt, req);
2010 p9_debug(P9_DEBUG_9P, "<<< RXATTRWALK fid %d size %llu\n",
2011 attr_fid->fid, *attr_size);
2012 return attr_fid;
2013 clunk_fid:
2014 p9_client_clunk(attr_fid);
2015 attr_fid = NULL;
2016 error:
2017 if (attr_fid && (attr_fid != file_fid))
2018 p9_fid_destroy(attr_fid);
2020 return ERR_PTR(err);
2022 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2024 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2025 u64 attr_size, int flags)
2027 int err;
2028 struct p9_req_t *req;
2029 struct p9_client *clnt;
2031 p9_debug(P9_DEBUG_9P,
2032 ">>> TXATTRCREATE fid %d name %s size %lld flag %d\n",
2033 fid->fid, name, (long long)attr_size, flags);
2034 err = 0;
2035 clnt = fid->clnt;
2036 req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2037 fid->fid, name, attr_size, flags);
2038 if (IS_ERR(req)) {
2039 err = PTR_ERR(req);
2040 goto error;
2042 p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2043 p9_free_req(clnt, req);
2044 error:
2045 return err;
2047 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2049 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2051 int err, rsize, non_zc = 0;
2052 struct p9_client *clnt;
2053 struct p9_req_t *req;
2054 char *dataptr;
2056 p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2057 fid->fid, (unsigned long long) offset, count);
2059 err = 0;
2060 clnt = fid->clnt;
2062 rsize = fid->iounit;
2063 if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2064 rsize = clnt->msize - P9_READDIRHDRSZ;
2066 if (count < rsize)
2067 rsize = count;
2069 /* Don't bother zerocopy for small IO (< 1024) */
2070 if (clnt->trans_mod->zc_request && rsize > 1024) {
2072 * response header len is 11
2073 * PDU Header(7) + IO Size (4)
2075 req = p9_client_zc_rpc(clnt, P9_TREADDIR, data, NULL, rsize, 0,
2076 11, 1, "dqd", fid->fid, offset, rsize);
2077 } else {
2078 non_zc = 1;
2079 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2080 offset, rsize);
2082 if (IS_ERR(req)) {
2083 err = PTR_ERR(req);
2084 goto error;
2087 err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2088 if (err) {
2089 trace_9p_protocol_dump(clnt, req->rc);
2090 goto free_and_error;
2093 p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2095 if (non_zc)
2096 memmove(data, dataptr, count);
2098 p9_free_req(clnt, req);
2099 return count;
2101 free_and_error:
2102 p9_free_req(clnt, req);
2103 error:
2104 return err;
2106 EXPORT_SYMBOL(p9_client_readdir);
2108 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2109 dev_t rdev, gid_t gid, struct p9_qid *qid)
2111 int err;
2112 struct p9_client *clnt;
2113 struct p9_req_t *req;
2115 err = 0;
2116 clnt = fid->clnt;
2117 p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2118 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2119 req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddd", fid->fid, name, mode,
2120 MAJOR(rdev), MINOR(rdev), gid);
2121 if (IS_ERR(req))
2122 return PTR_ERR(req);
2124 err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2125 if (err) {
2126 trace_9p_protocol_dump(clnt, req->rc);
2127 goto error;
2129 p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2130 (unsigned long long)qid->path, qid->version);
2132 error:
2133 p9_free_req(clnt, req);
2134 return err;
2137 EXPORT_SYMBOL(p9_client_mknod_dotl);
2139 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2140 gid_t gid, struct p9_qid *qid)
2142 int err;
2143 struct p9_client *clnt;
2144 struct p9_req_t *req;
2146 err = 0;
2147 clnt = fid->clnt;
2148 p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2149 fid->fid, name, mode, gid);
2150 req = p9_client_rpc(clnt, P9_TMKDIR, "dsdd", fid->fid, name, mode,
2151 gid);
2152 if (IS_ERR(req))
2153 return PTR_ERR(req);
2155 err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2156 if (err) {
2157 trace_9p_protocol_dump(clnt, req->rc);
2158 goto error;
2160 p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2161 (unsigned long long)qid->path, qid->version);
2163 error:
2164 p9_free_req(clnt, req);
2165 return err;
2168 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2170 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2172 int err;
2173 struct p9_client *clnt;
2174 struct p9_req_t *req;
2176 err = 0;
2177 clnt = fid->clnt;
2178 p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2179 "start %lld length %lld proc_id %d client_id %s\n",
2180 fid->fid, flock->type, flock->flags, flock->start,
2181 flock->length, flock->proc_id, flock->client_id);
2183 req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2184 flock->flags, flock->start, flock->length,
2185 flock->proc_id, flock->client_id);
2187 if (IS_ERR(req))
2188 return PTR_ERR(req);
2190 err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2191 if (err) {
2192 trace_9p_protocol_dump(clnt, req->rc);
2193 goto error;
2195 p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2196 error:
2197 p9_free_req(clnt, req);
2198 return err;
2201 EXPORT_SYMBOL(p9_client_lock_dotl);
2203 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2205 int err;
2206 struct p9_client *clnt;
2207 struct p9_req_t *req;
2209 err = 0;
2210 clnt = fid->clnt;
2211 p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2212 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2213 glock->start, glock->length, glock->proc_id, glock->client_id);
2215 req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid, glock->type,
2216 glock->start, glock->length, glock->proc_id, glock->client_id);
2218 if (IS_ERR(req))
2219 return PTR_ERR(req);
2221 err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2222 &glock->start, &glock->length, &glock->proc_id,
2223 &glock->client_id);
2224 if (err) {
2225 trace_9p_protocol_dump(clnt, req->rc);
2226 goto error;
2228 p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2229 "proc_id %d client_id %s\n", glock->type, glock->start,
2230 glock->length, glock->proc_id, glock->client_id);
2231 error:
2232 p9_free_req(clnt, req);
2233 return err;
2235 EXPORT_SYMBOL(p9_client_getlock_dotl);
2237 int p9_client_readlink(struct p9_fid *fid, char **target)
2239 int err;
2240 struct p9_client *clnt;
2241 struct p9_req_t *req;
2243 err = 0;
2244 clnt = fid->clnt;
2245 p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2247 req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2248 if (IS_ERR(req))
2249 return PTR_ERR(req);
2251 err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2252 if (err) {
2253 trace_9p_protocol_dump(clnt, req->rc);
2254 goto error;
2256 p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2257 error:
2258 p9_free_req(clnt, req);
2259 return err;
2261 EXPORT_SYMBOL(p9_client_readlink);