Linux 3.10.53
[linux/fpc-iii.git] / net / 9p / client.c
blobaddc116cecf0be16210498b6544fa40ad24cc615
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 int len;
566 /* 7 = header size for RERROR; */
567 int inline_len = in_hdrlen - 7;
569 len = req->rc->size - req->rc->offset;
570 if (len > (P9_ZC_HDR_SZ - 7)) {
571 err = -EFAULT;
572 goto out_err;
575 ename = &req->rc->sdata[req->rc->offset];
576 if (len > inline_len) {
577 /* We have error in external buffer */
578 if (kern_buf) {
579 memcpy(ename + inline_len, uidata,
580 len - inline_len);
581 } else {
582 err = copy_from_user(ename + inline_len,
583 uidata, len - inline_len);
584 if (err) {
585 err = -EFAULT;
586 goto out_err;
590 ename = NULL;
591 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
592 &ename, &ecode);
593 if (err)
594 goto out_err;
596 if (p9_is_proto_dotu(c))
597 err = -ecode;
599 if (!err || !IS_ERR_VALUE(err)) {
600 err = p9_errstr2errno(ename, strlen(ename));
602 p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
603 -ecode, ename);
605 kfree(ename);
606 } else {
607 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
608 err = -ecode;
610 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
612 return err;
614 out_err:
615 p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
616 return err;
619 static struct p9_req_t *
620 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
623 * p9_client_flush - flush (cancel) a request
624 * @c: client state
625 * @oldreq: request to cancel
627 * This sents a flush for a particular request and links
628 * the flush request to the original request. The current
629 * code only supports a single flush request although the protocol
630 * allows for multiple flush requests to be sent for a single request.
634 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
636 struct p9_req_t *req;
637 int16_t oldtag;
638 int err;
640 err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
641 if (err)
642 return err;
644 p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
646 req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
647 if (IS_ERR(req))
648 return PTR_ERR(req);
651 /* if we haven't received a response for oldreq,
652 remove it from the list. */
653 spin_lock(&c->lock);
654 if (oldreq->status == REQ_STATUS_FLSH)
655 list_del(&oldreq->req_list);
656 spin_unlock(&c->lock);
658 p9_free_req(c, req);
659 return 0;
662 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
663 int8_t type, int req_size,
664 const char *fmt, va_list ap)
666 int tag, err;
667 struct p9_req_t *req;
669 p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
671 /* we allow for any status other than disconnected */
672 if (c->status == Disconnected)
673 return ERR_PTR(-EIO);
675 /* if status is begin_disconnected we allow only clunk request */
676 if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
677 return ERR_PTR(-EIO);
679 tag = P9_NOTAG;
680 if (type != P9_TVERSION) {
681 tag = p9_idpool_get(c->tagpool);
682 if (tag < 0)
683 return ERR_PTR(-ENOMEM);
686 req = p9_tag_alloc(c, tag, req_size);
687 if (IS_ERR(req))
688 return req;
690 /* marshall the data */
691 p9pdu_prepare(req->tc, tag, type);
692 err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
693 if (err)
694 goto reterr;
695 p9pdu_finalize(c, req->tc);
696 trace_9p_client_req(c, type, tag);
697 return req;
698 reterr:
699 p9_free_req(c, req);
700 return ERR_PTR(err);
704 * p9_client_rpc - issue a request and wait for a response
705 * @c: client session
706 * @type: type of request
707 * @fmt: protocol format string (see protocol.c)
709 * Returns request structure (which client must free using p9_free_req)
712 static struct p9_req_t *
713 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
715 va_list ap;
716 int sigpending, err;
717 unsigned long flags;
718 struct p9_req_t *req;
720 va_start(ap, fmt);
721 req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
722 va_end(ap);
723 if (IS_ERR(req))
724 return req;
726 if (signal_pending(current)) {
727 sigpending = 1;
728 clear_thread_flag(TIF_SIGPENDING);
729 } else
730 sigpending = 0;
732 err = c->trans_mod->request(c, req);
733 if (err < 0) {
734 if (err != -ERESTARTSYS && err != -EFAULT)
735 c->status = Disconnected;
736 goto reterr;
738 again:
739 /* Wait for the response */
740 err = wait_event_interruptible(*req->wq,
741 req->status >= REQ_STATUS_RCVD);
743 if ((err == -ERESTARTSYS) && (c->status == Connected)
744 && (type == P9_TFLUSH)) {
745 sigpending = 1;
746 clear_thread_flag(TIF_SIGPENDING);
747 goto again;
750 if (req->status == REQ_STATUS_ERROR) {
751 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
752 err = req->t_err;
754 if ((err == -ERESTARTSYS) && (c->status == Connected)) {
755 p9_debug(P9_DEBUG_MUX, "flushing\n");
756 sigpending = 1;
757 clear_thread_flag(TIF_SIGPENDING);
759 if (c->trans_mod->cancel(c, req))
760 p9_client_flush(c, req);
762 /* if we received the response anyway, don't signal error */
763 if (req->status == REQ_STATUS_RCVD)
764 err = 0;
766 if (sigpending) {
767 spin_lock_irqsave(&current->sighand->siglock, flags);
768 recalc_sigpending();
769 spin_unlock_irqrestore(&current->sighand->siglock, flags);
771 if (err < 0)
772 goto reterr;
774 err = p9_check_errors(c, req);
775 trace_9p_client_res(c, type, req->rc->tag, err);
776 if (!err)
777 return req;
778 reterr:
779 p9_free_req(c, req);
780 return ERR_PTR(safe_errno(err));
784 * p9_client_zc_rpc - issue a request and wait for a response
785 * @c: client session
786 * @type: type of request
787 * @uidata: user bffer that should be ued for zero copy read
788 * @uodata: user buffer that shoud be user for zero copy write
789 * @inlen: read buffer size
790 * @olen: write buffer size
791 * @hdrlen: reader header size, This is the size of response protocol data
792 * @fmt: protocol format string (see protocol.c)
794 * Returns request structure (which client must free using p9_free_req)
796 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
797 char *uidata, char *uodata,
798 int inlen, int olen, int in_hdrlen,
799 int kern_buf, const char *fmt, ...)
801 va_list ap;
802 int sigpending, err;
803 unsigned long flags;
804 struct p9_req_t *req;
806 va_start(ap, fmt);
808 * We allocate a inline protocol data of only 4k bytes.
809 * The actual content is passed in zero-copy fashion.
811 req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
812 va_end(ap);
813 if (IS_ERR(req))
814 return req;
816 if (signal_pending(current)) {
817 sigpending = 1;
818 clear_thread_flag(TIF_SIGPENDING);
819 } else
820 sigpending = 0;
822 /* If we are called with KERNEL_DS force kern_buf */
823 if (segment_eq(get_fs(), KERNEL_DS))
824 kern_buf = 1;
826 err = c->trans_mod->zc_request(c, req, uidata, uodata,
827 inlen, olen, in_hdrlen, kern_buf);
828 if (err < 0) {
829 if (err == -EIO)
830 c->status = Disconnected;
831 goto reterr;
833 if (req->status == REQ_STATUS_ERROR) {
834 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
835 err = req->t_err;
837 if ((err == -ERESTARTSYS) && (c->status == Connected)) {
838 p9_debug(P9_DEBUG_MUX, "flushing\n");
839 sigpending = 1;
840 clear_thread_flag(TIF_SIGPENDING);
842 if (c->trans_mod->cancel(c, req))
843 p9_client_flush(c, req);
845 /* if we received the response anyway, don't signal error */
846 if (req->status == REQ_STATUS_RCVD)
847 err = 0;
849 if (sigpending) {
850 spin_lock_irqsave(&current->sighand->siglock, flags);
851 recalc_sigpending();
852 spin_unlock_irqrestore(&current->sighand->siglock, flags);
854 if (err < 0)
855 goto reterr;
857 err = p9_check_zc_errors(c, req, uidata, in_hdrlen, kern_buf);
858 trace_9p_client_res(c, type, req->rc->tag, err);
859 if (!err)
860 return req;
861 reterr:
862 p9_free_req(c, req);
863 return ERR_PTR(safe_errno(err));
866 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
868 int ret;
869 struct p9_fid *fid;
870 unsigned long flags;
872 p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
873 fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
874 if (!fid)
875 return ERR_PTR(-ENOMEM);
877 ret = p9_idpool_get(clnt->fidpool);
878 if (ret < 0) {
879 ret = -ENOSPC;
880 goto error;
882 fid->fid = ret;
884 memset(&fid->qid, 0, sizeof(struct p9_qid));
885 fid->mode = -1;
886 fid->uid = current_fsuid();
887 fid->clnt = clnt;
888 fid->rdir = NULL;
889 spin_lock_irqsave(&clnt->lock, flags);
890 list_add(&fid->flist, &clnt->fidlist);
891 spin_unlock_irqrestore(&clnt->lock, flags);
893 return fid;
895 error:
896 kfree(fid);
897 return ERR_PTR(ret);
900 static void p9_fid_destroy(struct p9_fid *fid)
902 struct p9_client *clnt;
903 unsigned long flags;
905 p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
906 clnt = fid->clnt;
907 p9_idpool_put(fid->fid, clnt->fidpool);
908 spin_lock_irqsave(&clnt->lock, flags);
909 list_del(&fid->flist);
910 spin_unlock_irqrestore(&clnt->lock, flags);
911 kfree(fid->rdir);
912 kfree(fid);
915 static int p9_client_version(struct p9_client *c)
917 int err = 0;
918 struct p9_req_t *req;
919 char *version;
920 int msize;
922 p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
923 c->msize, c->proto_version);
925 switch (c->proto_version) {
926 case p9_proto_2000L:
927 req = p9_client_rpc(c, P9_TVERSION, "ds",
928 c->msize, "9P2000.L");
929 break;
930 case p9_proto_2000u:
931 req = p9_client_rpc(c, P9_TVERSION, "ds",
932 c->msize, "9P2000.u");
933 break;
934 case p9_proto_legacy:
935 req = p9_client_rpc(c, P9_TVERSION, "ds",
936 c->msize, "9P2000");
937 break;
938 default:
939 return -EINVAL;
940 break;
943 if (IS_ERR(req))
944 return PTR_ERR(req);
946 err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
947 if (err) {
948 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
949 trace_9p_protocol_dump(c, req->rc);
950 goto error;
953 p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
954 if (!strncmp(version, "9P2000.L", 8))
955 c->proto_version = p9_proto_2000L;
956 else if (!strncmp(version, "9P2000.u", 8))
957 c->proto_version = p9_proto_2000u;
958 else if (!strncmp(version, "9P2000", 6))
959 c->proto_version = p9_proto_legacy;
960 else {
961 err = -EREMOTEIO;
962 goto error;
965 if (msize < c->msize)
966 c->msize = msize;
968 error:
969 kfree(version);
970 p9_free_req(c, req);
972 return err;
975 struct p9_client *p9_client_create(const char *dev_name, char *options)
977 int err;
978 struct p9_client *clnt;
980 err = 0;
981 clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
982 if (!clnt)
983 return ERR_PTR(-ENOMEM);
985 clnt->trans_mod = NULL;
986 clnt->trans = NULL;
987 spin_lock_init(&clnt->lock);
988 INIT_LIST_HEAD(&clnt->fidlist);
990 err = p9_tag_init(clnt);
991 if (err < 0)
992 goto free_client;
994 err = parse_opts(options, clnt);
995 if (err < 0)
996 goto destroy_tagpool;
998 if (!clnt->trans_mod)
999 clnt->trans_mod = v9fs_get_default_trans();
1001 if (clnt->trans_mod == NULL) {
1002 err = -EPROTONOSUPPORT;
1003 p9_debug(P9_DEBUG_ERROR,
1004 "No transport defined or default transport\n");
1005 goto destroy_tagpool;
1008 clnt->fidpool = p9_idpool_create();
1009 if (IS_ERR(clnt->fidpool)) {
1010 err = PTR_ERR(clnt->fidpool);
1011 goto put_trans;
1014 p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1015 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1017 err = clnt->trans_mod->create(clnt, dev_name, options);
1018 if (err)
1019 goto destroy_fidpool;
1021 if (clnt->msize > clnt->trans_mod->maxsize)
1022 clnt->msize = clnt->trans_mod->maxsize;
1024 err = p9_client_version(clnt);
1025 if (err)
1026 goto close_trans;
1028 return clnt;
1030 close_trans:
1031 clnt->trans_mod->close(clnt);
1032 destroy_fidpool:
1033 p9_idpool_destroy(clnt->fidpool);
1034 put_trans:
1035 v9fs_put_trans(clnt->trans_mod);
1036 destroy_tagpool:
1037 p9_idpool_destroy(clnt->tagpool);
1038 free_client:
1039 kfree(clnt);
1040 return ERR_PTR(err);
1042 EXPORT_SYMBOL(p9_client_create);
1044 void p9_client_destroy(struct p9_client *clnt)
1046 struct p9_fid *fid, *fidptr;
1048 p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1050 if (clnt->trans_mod)
1051 clnt->trans_mod->close(clnt);
1053 v9fs_put_trans(clnt->trans_mod);
1055 list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
1056 pr_info("Found fid %d not clunked\n", fid->fid);
1057 p9_fid_destroy(fid);
1060 if (clnt->fidpool)
1061 p9_idpool_destroy(clnt->fidpool);
1063 p9_tag_cleanup(clnt);
1065 kfree(clnt);
1067 EXPORT_SYMBOL(p9_client_destroy);
1069 void p9_client_disconnect(struct p9_client *clnt)
1071 p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1072 clnt->status = Disconnected;
1074 EXPORT_SYMBOL(p9_client_disconnect);
1076 void p9_client_begin_disconnect(struct p9_client *clnt)
1078 p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1079 clnt->status = BeginDisconnect;
1081 EXPORT_SYMBOL(p9_client_begin_disconnect);
1083 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1084 char *uname, kuid_t n_uname, char *aname)
1086 int err = 0;
1087 struct p9_req_t *req;
1088 struct p9_fid *fid;
1089 struct p9_qid qid;
1092 p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1093 afid ? afid->fid : -1, uname, aname);
1094 fid = p9_fid_create(clnt);
1095 if (IS_ERR(fid)) {
1096 err = PTR_ERR(fid);
1097 fid = NULL;
1098 goto error;
1101 req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1102 afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1103 if (IS_ERR(req)) {
1104 err = PTR_ERR(req);
1105 goto error;
1108 err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1109 if (err) {
1110 trace_9p_protocol_dump(clnt, req->rc);
1111 p9_free_req(clnt, req);
1112 goto error;
1115 p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1116 qid.type, (unsigned long long)qid.path, qid.version);
1118 memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1120 p9_free_req(clnt, req);
1121 return fid;
1123 error:
1124 if (fid)
1125 p9_fid_destroy(fid);
1126 return ERR_PTR(err);
1128 EXPORT_SYMBOL(p9_client_attach);
1130 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1131 char **wnames, int clone)
1133 int err;
1134 struct p9_client *clnt;
1135 struct p9_fid *fid;
1136 struct p9_qid *wqids;
1137 struct p9_req_t *req;
1138 uint16_t nwqids, count;
1140 err = 0;
1141 wqids = NULL;
1142 clnt = oldfid->clnt;
1143 if (clone) {
1144 fid = p9_fid_create(clnt);
1145 if (IS_ERR(fid)) {
1146 err = PTR_ERR(fid);
1147 fid = NULL;
1148 goto error;
1151 fid->uid = oldfid->uid;
1152 } else
1153 fid = oldfid;
1156 p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1157 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1159 req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1160 nwname, wnames);
1161 if (IS_ERR(req)) {
1162 err = PTR_ERR(req);
1163 goto error;
1166 err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1167 if (err) {
1168 trace_9p_protocol_dump(clnt, req->rc);
1169 p9_free_req(clnt, req);
1170 goto clunk_fid;
1172 p9_free_req(clnt, req);
1174 p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1176 if (nwqids != nwname) {
1177 err = -ENOENT;
1178 goto clunk_fid;
1181 for (count = 0; count < nwqids; count++)
1182 p9_debug(P9_DEBUG_9P, "<<< [%d] %x.%llx.%x\n",
1183 count, wqids[count].type,
1184 (unsigned long long)wqids[count].path,
1185 wqids[count].version);
1187 if (nwname)
1188 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1189 else
1190 fid->qid = oldfid->qid;
1192 kfree(wqids);
1193 return fid;
1195 clunk_fid:
1196 kfree(wqids);
1197 p9_client_clunk(fid);
1198 fid = NULL;
1200 error:
1201 if (fid && (fid != oldfid))
1202 p9_fid_destroy(fid);
1204 return ERR_PTR(err);
1206 EXPORT_SYMBOL(p9_client_walk);
1208 int p9_client_open(struct p9_fid *fid, int mode)
1210 int err;
1211 struct p9_client *clnt;
1212 struct p9_req_t *req;
1213 struct p9_qid qid;
1214 int iounit;
1216 clnt = fid->clnt;
1217 p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1218 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1219 err = 0;
1221 if (fid->mode != -1)
1222 return -EINVAL;
1224 if (p9_is_proto_dotl(clnt))
1225 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1226 else
1227 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1228 if (IS_ERR(req)) {
1229 err = PTR_ERR(req);
1230 goto error;
1233 err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1234 if (err) {
1235 trace_9p_protocol_dump(clnt, req->rc);
1236 goto free_and_error;
1239 p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1240 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN", qid.type,
1241 (unsigned long long)qid.path, qid.version, iounit);
1243 fid->mode = mode;
1244 fid->iounit = iounit;
1246 free_and_error:
1247 p9_free_req(clnt, req);
1248 error:
1249 return err;
1251 EXPORT_SYMBOL(p9_client_open);
1253 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1254 kgid_t gid, struct p9_qid *qid)
1256 int err = 0;
1257 struct p9_client *clnt;
1258 struct p9_req_t *req;
1259 int iounit;
1261 p9_debug(P9_DEBUG_9P,
1262 ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1263 ofid->fid, name, flags, mode,
1264 from_kgid(&init_user_ns, gid));
1265 clnt = ofid->clnt;
1267 if (ofid->mode != -1)
1268 return -EINVAL;
1270 req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1271 mode, gid);
1272 if (IS_ERR(req)) {
1273 err = PTR_ERR(req);
1274 goto error;
1277 err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1278 if (err) {
1279 trace_9p_protocol_dump(clnt, req->rc);
1280 goto free_and_error;
1283 p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1284 qid->type,
1285 (unsigned long long)qid->path,
1286 qid->version, iounit);
1288 ofid->mode = mode;
1289 ofid->iounit = iounit;
1291 free_and_error:
1292 p9_free_req(clnt, req);
1293 error:
1294 return err;
1296 EXPORT_SYMBOL(p9_client_create_dotl);
1298 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1299 char *extension)
1301 int err;
1302 struct p9_client *clnt;
1303 struct p9_req_t *req;
1304 struct p9_qid qid;
1305 int iounit;
1307 p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1308 fid->fid, name, perm, mode);
1309 err = 0;
1310 clnt = fid->clnt;
1312 if (fid->mode != -1)
1313 return -EINVAL;
1315 req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1316 mode, extension);
1317 if (IS_ERR(req)) {
1318 err = PTR_ERR(req);
1319 goto error;
1322 err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1323 if (err) {
1324 trace_9p_protocol_dump(clnt, req->rc);
1325 goto free_and_error;
1328 p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1329 qid.type,
1330 (unsigned long long)qid.path,
1331 qid.version, iounit);
1333 fid->mode = mode;
1334 fid->iounit = iounit;
1336 free_and_error:
1337 p9_free_req(clnt, req);
1338 error:
1339 return err;
1341 EXPORT_SYMBOL(p9_client_fcreate);
1343 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
1344 struct p9_qid *qid)
1346 int err = 0;
1347 struct p9_client *clnt;
1348 struct p9_req_t *req;
1350 p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s symtgt %s\n",
1351 dfid->fid, name, symtgt);
1352 clnt = dfid->clnt;
1354 req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1355 gid);
1356 if (IS_ERR(req)) {
1357 err = PTR_ERR(req);
1358 goto error;
1361 err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1362 if (err) {
1363 trace_9p_protocol_dump(clnt, req->rc);
1364 goto free_and_error;
1367 p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1368 qid->type, (unsigned long long)qid->path, qid->version);
1370 free_and_error:
1371 p9_free_req(clnt, req);
1372 error:
1373 return err;
1375 EXPORT_SYMBOL(p9_client_symlink);
1377 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1379 struct p9_client *clnt;
1380 struct p9_req_t *req;
1382 p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1383 dfid->fid, oldfid->fid, newname);
1384 clnt = dfid->clnt;
1385 req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1386 newname);
1387 if (IS_ERR(req))
1388 return PTR_ERR(req);
1390 p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1391 p9_free_req(clnt, req);
1392 return 0;
1394 EXPORT_SYMBOL(p9_client_link);
1396 int p9_client_fsync(struct p9_fid *fid, int datasync)
1398 int err;
1399 struct p9_client *clnt;
1400 struct p9_req_t *req;
1402 p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1403 fid->fid, datasync);
1404 err = 0;
1405 clnt = fid->clnt;
1407 req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1408 if (IS_ERR(req)) {
1409 err = PTR_ERR(req);
1410 goto error;
1413 p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1415 p9_free_req(clnt, req);
1417 error:
1418 return err;
1420 EXPORT_SYMBOL(p9_client_fsync);
1422 int p9_client_clunk(struct p9_fid *fid)
1424 int err;
1425 struct p9_client *clnt;
1426 struct p9_req_t *req;
1427 int retries = 0;
1429 if (!fid) {
1430 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1431 __func__, task_pid_nr(current));
1432 dump_stack();
1433 return 0;
1436 again:
1437 p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1438 retries);
1439 err = 0;
1440 clnt = fid->clnt;
1442 req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1443 if (IS_ERR(req)) {
1444 err = PTR_ERR(req);
1445 goto error;
1448 p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1450 p9_free_req(clnt, req);
1451 error:
1453 * Fid is not valid even after a failed clunk
1454 * If interrupted, retry once then give up and
1455 * leak fid until umount.
1457 if (err == -ERESTARTSYS) {
1458 if (retries++ == 0)
1459 goto again;
1460 } else
1461 p9_fid_destroy(fid);
1462 return err;
1464 EXPORT_SYMBOL(p9_client_clunk);
1466 int p9_client_remove(struct p9_fid *fid)
1468 int err;
1469 struct p9_client *clnt;
1470 struct p9_req_t *req;
1472 p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1473 err = 0;
1474 clnt = fid->clnt;
1476 req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1477 if (IS_ERR(req)) {
1478 err = PTR_ERR(req);
1479 goto error;
1482 p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1484 p9_free_req(clnt, req);
1485 error:
1486 if (err == -ERESTARTSYS)
1487 p9_client_clunk(fid);
1488 else
1489 p9_fid_destroy(fid);
1490 return err;
1492 EXPORT_SYMBOL(p9_client_remove);
1494 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1496 int err = 0;
1497 struct p9_req_t *req;
1498 struct p9_client *clnt;
1500 p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1501 dfid->fid, name, flags);
1503 clnt = dfid->clnt;
1504 req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1505 if (IS_ERR(req)) {
1506 err = PTR_ERR(req);
1507 goto error;
1509 p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1511 p9_free_req(clnt, req);
1512 error:
1513 return err;
1515 EXPORT_SYMBOL(p9_client_unlinkat);
1518 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1519 u32 count)
1521 char *dataptr;
1522 int kernel_buf = 0;
1523 struct p9_req_t *req;
1524 struct p9_client *clnt;
1525 int err, rsize, non_zc = 0;
1528 p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1529 fid->fid, (unsigned long long) offset, count);
1530 err = 0;
1531 clnt = fid->clnt;
1533 rsize = fid->iounit;
1534 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1535 rsize = clnt->msize - P9_IOHDRSZ;
1537 if (count < rsize)
1538 rsize = count;
1540 /* Don't bother zerocopy for small IO (< 1024) */
1541 if (clnt->trans_mod->zc_request && rsize > 1024) {
1542 char *indata;
1543 if (data) {
1544 kernel_buf = 1;
1545 indata = data;
1546 } else
1547 indata = (__force char *)udata;
1549 * response header len is 11
1550 * PDU Header(7) + IO Size (4)
1552 req = p9_client_zc_rpc(clnt, P9_TREAD, indata, NULL, rsize, 0,
1553 11, kernel_buf, "dqd", fid->fid,
1554 offset, rsize);
1555 } else {
1556 non_zc = 1;
1557 req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1558 rsize);
1560 if (IS_ERR(req)) {
1561 err = PTR_ERR(req);
1562 goto error;
1565 err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1566 if (err) {
1567 trace_9p_protocol_dump(clnt, req->rc);
1568 goto free_and_error;
1571 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1573 if (non_zc) {
1574 if (data) {
1575 memmove(data, dataptr, count);
1576 } else {
1577 err = copy_to_user(udata, dataptr, count);
1578 if (err) {
1579 err = -EFAULT;
1580 goto free_and_error;
1584 p9_free_req(clnt, req);
1585 return count;
1587 free_and_error:
1588 p9_free_req(clnt, req);
1589 error:
1590 return err;
1592 EXPORT_SYMBOL(p9_client_read);
1595 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1596 u64 offset, u32 count)
1598 int err, rsize;
1599 int kernel_buf = 0;
1600 struct p9_client *clnt;
1601 struct p9_req_t *req;
1603 p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1604 fid->fid, (unsigned long long) offset, count);
1605 err = 0;
1606 clnt = fid->clnt;
1608 rsize = fid->iounit;
1609 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1610 rsize = clnt->msize - P9_IOHDRSZ;
1612 if (count < rsize)
1613 rsize = count;
1615 /* Don't bother zerocopy for small IO (< 1024) */
1616 if (clnt->trans_mod->zc_request && rsize > 1024) {
1617 char *odata;
1618 if (data) {
1619 kernel_buf = 1;
1620 odata = data;
1621 } else
1622 odata = (char *)udata;
1623 req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, odata, 0, rsize,
1624 P9_ZC_HDR_SZ, kernel_buf, "dqd",
1625 fid->fid, offset, rsize);
1626 } else {
1627 if (data)
1628 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1629 offset, rsize, data);
1630 else
1631 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1632 offset, rsize, udata);
1634 if (IS_ERR(req)) {
1635 err = PTR_ERR(req);
1636 goto error;
1639 err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1640 if (err) {
1641 trace_9p_protocol_dump(clnt, req->rc);
1642 goto free_and_error;
1645 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1647 p9_free_req(clnt, req);
1648 return count;
1650 free_and_error:
1651 p9_free_req(clnt, req);
1652 error:
1653 return err;
1655 EXPORT_SYMBOL(p9_client_write);
1657 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1659 int err;
1660 struct p9_client *clnt;
1661 struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1662 struct p9_req_t *req;
1663 u16 ignored;
1665 p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1667 if (!ret)
1668 return ERR_PTR(-ENOMEM);
1670 err = 0;
1671 clnt = fid->clnt;
1673 req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1674 if (IS_ERR(req)) {
1675 err = PTR_ERR(req);
1676 goto error;
1679 err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1680 if (err) {
1681 trace_9p_protocol_dump(clnt, req->rc);
1682 p9_free_req(clnt, req);
1683 goto error;
1686 p9_debug(P9_DEBUG_9P,
1687 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1688 "<<< mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1689 "<<< name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1690 "<<< uid=%d gid=%d n_muid=%d\n",
1691 ret->size, ret->type, ret->dev, ret->qid.type,
1692 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1693 ret->atime, ret->mtime, (unsigned long long)ret->length,
1694 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1695 from_kuid(&init_user_ns, ret->n_uid),
1696 from_kgid(&init_user_ns, ret->n_gid),
1697 from_kuid(&init_user_ns, ret->n_muid));
1699 p9_free_req(clnt, req);
1700 return ret;
1702 error:
1703 kfree(ret);
1704 return ERR_PTR(err);
1706 EXPORT_SYMBOL(p9_client_stat);
1708 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1709 u64 request_mask)
1711 int err;
1712 struct p9_client *clnt;
1713 struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1714 GFP_KERNEL);
1715 struct p9_req_t *req;
1717 p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1718 fid->fid, request_mask);
1720 if (!ret)
1721 return ERR_PTR(-ENOMEM);
1723 err = 0;
1724 clnt = fid->clnt;
1726 req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1727 if (IS_ERR(req)) {
1728 err = PTR_ERR(req);
1729 goto error;
1732 err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1733 if (err) {
1734 trace_9p_protocol_dump(clnt, req->rc);
1735 p9_free_req(clnt, req);
1736 goto error;
1739 p9_debug(P9_DEBUG_9P,
1740 "<<< RGETATTR st_result_mask=%lld\n"
1741 "<<< qid=%x.%llx.%x\n"
1742 "<<< st_mode=%8.8x st_nlink=%llu\n"
1743 "<<< st_uid=%d st_gid=%d\n"
1744 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1745 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1746 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1747 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1748 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1749 "<<< st_gen=%lld st_data_version=%lld",
1750 ret->st_result_mask, ret->qid.type, ret->qid.path,
1751 ret->qid.version, ret->st_mode, ret->st_nlink,
1752 from_kuid(&init_user_ns, ret->st_uid),
1753 from_kgid(&init_user_ns, ret->st_gid),
1754 ret->st_rdev, ret->st_size, ret->st_blksize,
1755 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1756 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1757 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1758 ret->st_gen, ret->st_data_version);
1760 p9_free_req(clnt, req);
1761 return ret;
1763 error:
1764 kfree(ret);
1765 return ERR_PTR(err);
1767 EXPORT_SYMBOL(p9_client_getattr_dotl);
1769 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1771 int ret;
1773 /* NOTE: size shouldn't include its own length */
1774 /* size[2] type[2] dev[4] qid[13] */
1775 /* mode[4] atime[4] mtime[4] length[8]*/
1776 /* name[s] uid[s] gid[s] muid[s] */
1777 ret = 2+4+13+4+4+4+8+2+2+2+2;
1779 if (wst->name)
1780 ret += strlen(wst->name);
1781 if (wst->uid)
1782 ret += strlen(wst->uid);
1783 if (wst->gid)
1784 ret += strlen(wst->gid);
1785 if (wst->muid)
1786 ret += strlen(wst->muid);
1788 if ((proto_version == p9_proto_2000u) ||
1789 (proto_version == p9_proto_2000L)) {
1790 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1791 if (wst->extension)
1792 ret += strlen(wst->extension);
1795 return ret;
1798 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1800 int err;
1801 struct p9_req_t *req;
1802 struct p9_client *clnt;
1804 err = 0;
1805 clnt = fid->clnt;
1806 wst->size = p9_client_statsize(wst, clnt->proto_version);
1807 p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1808 p9_debug(P9_DEBUG_9P,
1809 " sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1810 " mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1811 " name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1812 " uid=%d gid=%d n_muid=%d\n",
1813 wst->size, wst->type, wst->dev, wst->qid.type,
1814 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1815 wst->atime, wst->mtime, (unsigned long long)wst->length,
1816 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1817 from_kuid(&init_user_ns, wst->n_uid),
1818 from_kgid(&init_user_ns, wst->n_gid),
1819 from_kuid(&init_user_ns, wst->n_muid));
1821 req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1822 if (IS_ERR(req)) {
1823 err = PTR_ERR(req);
1824 goto error;
1827 p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1829 p9_free_req(clnt, req);
1830 error:
1831 return err;
1833 EXPORT_SYMBOL(p9_client_wstat);
1835 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1837 int err;
1838 struct p9_req_t *req;
1839 struct p9_client *clnt;
1841 err = 0;
1842 clnt = fid->clnt;
1843 p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1844 p9_debug(P9_DEBUG_9P,
1845 " valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1846 " atime_sec=%lld atime_nsec=%lld\n"
1847 " mtime_sec=%lld mtime_nsec=%lld\n",
1848 p9attr->valid, p9attr->mode,
1849 from_kuid(&init_user_ns, p9attr->uid),
1850 from_kgid(&init_user_ns, p9attr->gid),
1851 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1852 p9attr->mtime_sec, p9attr->mtime_nsec);
1854 req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1856 if (IS_ERR(req)) {
1857 err = PTR_ERR(req);
1858 goto error;
1860 p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1861 p9_free_req(clnt, req);
1862 error:
1863 return err;
1865 EXPORT_SYMBOL(p9_client_setattr);
1867 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1869 int err;
1870 struct p9_req_t *req;
1871 struct p9_client *clnt;
1873 err = 0;
1874 clnt = fid->clnt;
1876 p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1878 req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1879 if (IS_ERR(req)) {
1880 err = PTR_ERR(req);
1881 goto error;
1884 err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1885 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1886 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1887 if (err) {
1888 trace_9p_protocol_dump(clnt, req->rc);
1889 p9_free_req(clnt, req);
1890 goto error;
1893 p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1894 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1895 "fsid %llu namelen %ld\n",
1896 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1897 sb->blocks, sb->bfree, sb->bavail, sb->files, sb->ffree,
1898 sb->fsid, (long int)sb->namelen);
1900 p9_free_req(clnt, req);
1901 error:
1902 return err;
1904 EXPORT_SYMBOL(p9_client_statfs);
1906 int p9_client_rename(struct p9_fid *fid,
1907 struct p9_fid *newdirfid, const char *name)
1909 int err;
1910 struct p9_req_t *req;
1911 struct p9_client *clnt;
1913 err = 0;
1914 clnt = fid->clnt;
1916 p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1917 fid->fid, newdirfid->fid, name);
1919 req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1920 newdirfid->fid, name);
1921 if (IS_ERR(req)) {
1922 err = PTR_ERR(req);
1923 goto error;
1926 p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1928 p9_free_req(clnt, req);
1929 error:
1930 return err;
1932 EXPORT_SYMBOL(p9_client_rename);
1934 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1935 struct p9_fid *newdirfid, const char *new_name)
1937 int err;
1938 struct p9_req_t *req;
1939 struct p9_client *clnt;
1941 err = 0;
1942 clnt = olddirfid->clnt;
1944 p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1945 " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1946 newdirfid->fid, new_name);
1948 req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1949 old_name, newdirfid->fid, new_name);
1950 if (IS_ERR(req)) {
1951 err = PTR_ERR(req);
1952 goto error;
1955 p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1956 newdirfid->fid, new_name);
1958 p9_free_req(clnt, req);
1959 error:
1960 return err;
1962 EXPORT_SYMBOL(p9_client_renameat);
1965 * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1967 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1968 const char *attr_name, u64 *attr_size)
1970 int err;
1971 struct p9_req_t *req;
1972 struct p9_client *clnt;
1973 struct p9_fid *attr_fid;
1975 err = 0;
1976 clnt = file_fid->clnt;
1977 attr_fid = p9_fid_create(clnt);
1978 if (IS_ERR(attr_fid)) {
1979 err = PTR_ERR(attr_fid);
1980 attr_fid = NULL;
1981 goto error;
1983 p9_debug(P9_DEBUG_9P,
1984 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1985 file_fid->fid, attr_fid->fid, attr_name);
1987 req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1988 file_fid->fid, attr_fid->fid, attr_name);
1989 if (IS_ERR(req)) {
1990 err = PTR_ERR(req);
1991 goto error;
1993 err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
1994 if (err) {
1995 trace_9p_protocol_dump(clnt, req->rc);
1996 p9_free_req(clnt, req);
1997 goto clunk_fid;
1999 p9_free_req(clnt, req);
2000 p9_debug(P9_DEBUG_9P, "<<< RXATTRWALK fid %d size %llu\n",
2001 attr_fid->fid, *attr_size);
2002 return attr_fid;
2003 clunk_fid:
2004 p9_client_clunk(attr_fid);
2005 attr_fid = NULL;
2006 error:
2007 if (attr_fid && (attr_fid != file_fid))
2008 p9_fid_destroy(attr_fid);
2010 return ERR_PTR(err);
2012 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2014 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2015 u64 attr_size, int flags)
2017 int err;
2018 struct p9_req_t *req;
2019 struct p9_client *clnt;
2021 p9_debug(P9_DEBUG_9P,
2022 ">>> TXATTRCREATE fid %d name %s size %lld flag %d\n",
2023 fid->fid, name, (long long)attr_size, flags);
2024 err = 0;
2025 clnt = fid->clnt;
2026 req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2027 fid->fid, name, attr_size, flags);
2028 if (IS_ERR(req)) {
2029 err = PTR_ERR(req);
2030 goto error;
2032 p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2033 p9_free_req(clnt, req);
2034 error:
2035 return err;
2037 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2039 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2041 int err, rsize, non_zc = 0;
2042 struct p9_client *clnt;
2043 struct p9_req_t *req;
2044 char *dataptr;
2046 p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2047 fid->fid, (unsigned long long) offset, count);
2049 err = 0;
2050 clnt = fid->clnt;
2052 rsize = fid->iounit;
2053 if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2054 rsize = clnt->msize - P9_READDIRHDRSZ;
2056 if (count < rsize)
2057 rsize = count;
2059 /* Don't bother zerocopy for small IO (< 1024) */
2060 if (clnt->trans_mod->zc_request && rsize > 1024) {
2062 * response header len is 11
2063 * PDU Header(7) + IO Size (4)
2065 req = p9_client_zc_rpc(clnt, P9_TREADDIR, data, NULL, rsize, 0,
2066 11, 1, "dqd", fid->fid, offset, rsize);
2067 } else {
2068 non_zc = 1;
2069 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2070 offset, rsize);
2072 if (IS_ERR(req)) {
2073 err = PTR_ERR(req);
2074 goto error;
2077 err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2078 if (err) {
2079 trace_9p_protocol_dump(clnt, req->rc);
2080 goto free_and_error;
2083 p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2085 if (non_zc)
2086 memmove(data, dataptr, count);
2088 p9_free_req(clnt, req);
2089 return count;
2091 free_and_error:
2092 p9_free_req(clnt, req);
2093 error:
2094 return err;
2096 EXPORT_SYMBOL(p9_client_readdir);
2098 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
2099 dev_t rdev, kgid_t gid, struct p9_qid *qid)
2101 int err;
2102 struct p9_client *clnt;
2103 struct p9_req_t *req;
2105 err = 0;
2106 clnt = fid->clnt;
2107 p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2108 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2109 req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2110 MAJOR(rdev), MINOR(rdev), gid);
2111 if (IS_ERR(req))
2112 return PTR_ERR(req);
2114 err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2115 if (err) {
2116 trace_9p_protocol_dump(clnt, req->rc);
2117 goto error;
2119 p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2120 (unsigned long long)qid->path, qid->version);
2122 error:
2123 p9_free_req(clnt, req);
2124 return err;
2127 EXPORT_SYMBOL(p9_client_mknod_dotl);
2129 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
2130 kgid_t gid, struct p9_qid *qid)
2132 int err;
2133 struct p9_client *clnt;
2134 struct p9_req_t *req;
2136 err = 0;
2137 clnt = fid->clnt;
2138 p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2139 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2140 req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2141 gid);
2142 if (IS_ERR(req))
2143 return PTR_ERR(req);
2145 err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2146 if (err) {
2147 trace_9p_protocol_dump(clnt, req->rc);
2148 goto error;
2150 p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2151 (unsigned long long)qid->path, qid->version);
2153 error:
2154 p9_free_req(clnt, req);
2155 return err;
2158 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2160 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2162 int err;
2163 struct p9_client *clnt;
2164 struct p9_req_t *req;
2166 err = 0;
2167 clnt = fid->clnt;
2168 p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2169 "start %lld length %lld proc_id %d client_id %s\n",
2170 fid->fid, flock->type, flock->flags, flock->start,
2171 flock->length, flock->proc_id, flock->client_id);
2173 req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2174 flock->flags, flock->start, flock->length,
2175 flock->proc_id, flock->client_id);
2177 if (IS_ERR(req))
2178 return PTR_ERR(req);
2180 err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2181 if (err) {
2182 trace_9p_protocol_dump(clnt, req->rc);
2183 goto error;
2185 p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2186 error:
2187 p9_free_req(clnt, req);
2188 return err;
2191 EXPORT_SYMBOL(p9_client_lock_dotl);
2193 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2195 int err;
2196 struct p9_client *clnt;
2197 struct p9_req_t *req;
2199 err = 0;
2200 clnt = fid->clnt;
2201 p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2202 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2203 glock->start, glock->length, glock->proc_id, glock->client_id);
2205 req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid, glock->type,
2206 glock->start, glock->length, glock->proc_id, glock->client_id);
2208 if (IS_ERR(req))
2209 return PTR_ERR(req);
2211 err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2212 &glock->start, &glock->length, &glock->proc_id,
2213 &glock->client_id);
2214 if (err) {
2215 trace_9p_protocol_dump(clnt, req->rc);
2216 goto error;
2218 p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2219 "proc_id %d client_id %s\n", glock->type, glock->start,
2220 glock->length, glock->proc_id, glock->client_id);
2221 error:
2222 p9_free_req(clnt, req);
2223 return err;
2225 EXPORT_SYMBOL(p9_client_getlock_dotl);
2227 int p9_client_readlink(struct p9_fid *fid, char **target)
2229 int err;
2230 struct p9_client *clnt;
2231 struct p9_req_t *req;
2233 err = 0;
2234 clnt = fid->clnt;
2235 p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2237 req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2238 if (IS_ERR(req))
2239 return PTR_ERR(req);
2241 err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2242 if (err) {
2243 trace_9p_protocol_dump(clnt, req->rc);
2244 goto error;
2246 p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2247 error:
2248 p9_free_req(clnt, req);
2249 return err;
2251 EXPORT_SYMBOL(p9_client_readlink);