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TOMOYO Linux Cross Reference
Linux/net/9p/client.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * net/9p/clnt.c
  4  *
  5  * 9P Client
  6  *
  7  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
  8  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
  9  */
 10 
 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 12 
 13 #include <linux/module.h>
 14 #include <linux/errno.h>
 15 #include <linux/fs.h>
 16 #include <linux/poll.h>
 17 #include <linux/idr.h>
 18 #include <linux/mutex.h>
 19 #include <linux/slab.h>
 20 #include <linux/sched/signal.h>
 21 #include <linux/uaccess.h>
 22 #include <linux/uio.h>
 23 #include <net/9p/9p.h>
 24 #include <linux/parser.h>
 25 #include <linux/seq_file.h>
 26 #include <net/9p/client.h>
 27 #include <net/9p/transport.h>
 28 #include "protocol.h"
 29 
 30 #define CREATE_TRACE_POINTS
 31 #include <trace/events/9p.h>
 32 
 33 /*
 34   * Client Option Parsing (code inspired by NFS code)
 35   *  - a little lazy - parse all client options
 36   */
 37 
 38 enum {
 39         Opt_msize,
 40         Opt_trans,
 41         Opt_legacy,
 42         Opt_version,
 43         Opt_err,
 44 };
 45 
 46 static const match_table_t tokens = {
 47         {Opt_msize, "msize=%u"},
 48         {Opt_legacy, "noextend"},
 49         {Opt_trans, "trans=%s"},
 50         {Opt_version, "version=%s"},
 51         {Opt_err, NULL},
 52 };
 53 
 54 inline int p9_is_proto_dotl(struct p9_client *clnt)
 55 {
 56         return clnt->proto_version == p9_proto_2000L;
 57 }
 58 EXPORT_SYMBOL(p9_is_proto_dotl);
 59 
 60 inline int p9_is_proto_dotu(struct p9_client *clnt)
 61 {
 62         return clnt->proto_version == p9_proto_2000u;
 63 }
 64 EXPORT_SYMBOL(p9_is_proto_dotu);
 65 
 66 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
 67 {
 68         if (clnt->msize != 8192)
 69                 seq_printf(m, ",msize=%u", clnt->msize);
 70         seq_printf(m, ",trans=%s", clnt->trans_mod->name);
 71 
 72         switch (clnt->proto_version) {
 73         case p9_proto_legacy:
 74                 seq_puts(m, ",noextend");
 75                 break;
 76         case p9_proto_2000u:
 77                 seq_puts(m, ",version=9p2000.u");
 78                 break;
 79         case p9_proto_2000L:
 80                 /* Default */
 81                 break;
 82         }
 83 
 84         if (clnt->trans_mod->show_options)
 85                 return clnt->trans_mod->show_options(m, clnt);
 86         return 0;
 87 }
 88 EXPORT_SYMBOL(p9_show_client_options);
 89 
 90 /*
 91  * Some error codes are taken directly from the server replies,
 92  * make sure they are valid.
 93  */
 94 static int safe_errno(int err)
 95 {
 96         if ((err > 0) || (err < -MAX_ERRNO)) {
 97                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
 98                 return -EPROTO;
 99         }
100         return err;
101 }
102 
103 
104 /* Interpret mount option for protocol version */
105 static int get_protocol_version(char *s)
106 {
107         int version = -EINVAL;
108 
109         if (!strcmp(s, "9p2000")) {
110                 version = p9_proto_legacy;
111                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
112         } else if (!strcmp(s, "9p2000.u")) {
113                 version = p9_proto_2000u;
114                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
115         } else if (!strcmp(s, "9p2000.L")) {
116                 version = p9_proto_2000L;
117                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
118         } else
119                 pr_info("Unknown protocol version %s\n", s);
120 
121         return version;
122 }
123 
124 /**
125  * parse_options - parse mount options into client structure
126  * @opts: options string passed from mount
127  * @clnt: existing v9fs client information
128  *
129  * Return 0 upon success, -ERRNO upon failure
130  */
131 
132 static int parse_opts(char *opts, struct p9_client *clnt)
133 {
134         char *options, *tmp_options;
135         char *p;
136         substring_t args[MAX_OPT_ARGS];
137         int option;
138         char *s;
139         int ret = 0;
140 
141         clnt->proto_version = p9_proto_2000L;
142         clnt->msize = 8192;
143 
144         if (!opts)
145                 return 0;
146 
147         tmp_options = kstrdup(opts, GFP_KERNEL);
148         if (!tmp_options) {
149                 p9_debug(P9_DEBUG_ERROR,
150                          "failed to allocate copy of option string\n");
151                 return -ENOMEM;
152         }
153         options = tmp_options;
154 
155         while ((p = strsep(&options, ",")) != NULL) {
156                 int token, r;
157                 if (!*p)
158                         continue;
159                 token = match_token(p, tokens, args);
160                 switch (token) {
161                 case Opt_msize:
162                         r = match_int(&args[0], &option);
163                         if (r < 0) {
164                                 p9_debug(P9_DEBUG_ERROR,
165                                          "integer field, but no integer?\n");
166                                 ret = r;
167                                 continue;
168                         }
169                         if (option < 4096) {
170                                 p9_debug(P9_DEBUG_ERROR,
171                                          "msize should be at least 4k\n");
172                                 ret = -EINVAL;
173                                 continue;
174                         }
175                         clnt->msize = option;
176                         break;
177                 case Opt_trans:
178                         s = match_strdup(&args[0]);
179                         if (!s) {
180                                 ret = -ENOMEM;
181                                 p9_debug(P9_DEBUG_ERROR,
182                                          "problem allocating copy of trans arg\n");
183                                 goto free_and_return;
184                         }
185 
186                         v9fs_put_trans(clnt->trans_mod);
187                         clnt->trans_mod = v9fs_get_trans_by_name(s);
188                         if (clnt->trans_mod == NULL) {
189                                 pr_info("Could not find request transport: %s\n",
190                                         s);
191                                 ret = -EINVAL;
192                         }
193                         kfree(s);
194                         break;
195                 case Opt_legacy:
196                         clnt->proto_version = p9_proto_legacy;
197                         break;
198                 case Opt_version:
199                         s = match_strdup(&args[0]);
200                         if (!s) {
201                                 ret = -ENOMEM;
202                                 p9_debug(P9_DEBUG_ERROR,
203                                          "problem allocating copy of version arg\n");
204                                 goto free_and_return;
205                         }
206                         r = get_protocol_version(s);
207                         if (r < 0)
208                                 ret = r;
209                         else
210                                 clnt->proto_version = r;
211                         kfree(s);
212                         break;
213                 default:
214                         continue;
215                 }
216         }
217 
218 free_and_return:
219         if (ret)
220                 v9fs_put_trans(clnt->trans_mod);
221         kfree(tmp_options);
222         return ret;
223 }
224 
225 static int p9_fcall_init(struct p9_client *c, struct p9_fcall *fc,
226                          int alloc_msize)
227 {
228         if (likely(c->fcall_cache) && alloc_msize == c->msize) {
229                 fc->sdata = kmem_cache_alloc(c->fcall_cache, GFP_NOFS);
230                 fc->cache = c->fcall_cache;
231         } else {
232                 fc->sdata = kmalloc(alloc_msize, GFP_NOFS);
233                 fc->cache = NULL;
234         }
235         if (!fc->sdata)
236                 return -ENOMEM;
237         fc->capacity = alloc_msize;
238         return 0;
239 }
240 
241 void p9_fcall_fini(struct p9_fcall *fc)
242 {
243         /* sdata can be NULL for interrupted requests in trans_rdma,
244          * and kmem_cache_free does not do NULL-check for us
245          */
246         if (unlikely(!fc->sdata))
247                 return;
248 
249         if (fc->cache)
250                 kmem_cache_free(fc->cache, fc->sdata);
251         else
252                 kfree(fc->sdata);
253 }
254 EXPORT_SYMBOL(p9_fcall_fini);
255 
256 static struct kmem_cache *p9_req_cache;
257 
258 /**
259  * p9_req_alloc - Allocate a new request.
260  * @c: Client session.
261  * @type: Transaction type.
262  * @max_size: Maximum packet size for this request.
263  *
264  * Context: Process context.
265  * Return: Pointer to new request.
266  */
267 static struct p9_req_t *
268 p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
269 {
270         struct p9_req_t *req = kmem_cache_alloc(p9_req_cache, GFP_NOFS);
271         int alloc_msize = min(c->msize, max_size);
272         int tag;
273 
274         if (!req)
275                 return ERR_PTR(-ENOMEM);
276 
277         if (p9_fcall_init(c, &req->tc, alloc_msize))
278                 goto free_req;
279         if (p9_fcall_init(c, &req->rc, alloc_msize))
280                 goto free;
281 
282         p9pdu_reset(&req->tc);
283         p9pdu_reset(&req->rc);
284         req->t_err = 0;
285         req->status = REQ_STATUS_ALLOC;
286         init_waitqueue_head(&req->wq);
287         INIT_LIST_HEAD(&req->req_list);
288 
289         idr_preload(GFP_NOFS);
290         spin_lock_irq(&c->lock);
291         if (type == P9_TVERSION)
292                 tag = idr_alloc(&c->reqs, req, P9_NOTAG, P9_NOTAG + 1,
293                                 GFP_NOWAIT);
294         else
295                 tag = idr_alloc(&c->reqs, req, 0, P9_NOTAG, GFP_NOWAIT);
296         req->tc.tag = tag;
297         spin_unlock_irq(&c->lock);
298         idr_preload_end();
299         if (tag < 0)
300                 goto free;
301 
302         /* Init ref to two because in the general case there is one ref
303          * that is put asynchronously by a writer thread, one ref
304          * temporarily given by p9_tag_lookup and put by p9_client_cb
305          * in the recv thread, and one ref put by p9_tag_remove in the
306          * main thread. The only exception is virtio that does not use
307          * p9_tag_lookup but does not have a writer thread either
308          * (the write happens synchronously in the request/zc_request
309          * callback), so p9_client_cb eats the second ref there
310          * as the pointer is duplicated directly by virtqueue_add_sgs()
311          */
312         refcount_set(&req->refcount.refcount, 2);
313 
314         return req;
315 
316 free:
317         p9_fcall_fini(&req->tc);
318         p9_fcall_fini(&req->rc);
319 free_req:
320         kmem_cache_free(p9_req_cache, req);
321         return ERR_PTR(-ENOMEM);
322 }
323 
324 /**
325  * p9_tag_lookup - Look up a request by tag.
326  * @c: Client session.
327  * @tag: Transaction ID.
328  *
329  * Context: Any context.
330  * Return: A request, or %NULL if there is no request with that tag.
331  */
332 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
333 {
334         struct p9_req_t *req;
335 
336         rcu_read_lock();
337 again:
338         req = idr_find(&c->reqs, tag);
339         if (req) {
340                 /* We have to be careful with the req found under rcu_read_lock
341                  * Thanks to SLAB_TYPESAFE_BY_RCU we can safely try to get the
342                  * ref again without corrupting other data, then check again
343                  * that the tag matches once we have the ref
344                  */
345                 if (!p9_req_try_get(req))
346                         goto again;
347                 if (req->tc.tag != tag) {
348                         p9_req_put(req);
349                         goto again;
350                 }
351         }
352         rcu_read_unlock();
353 
354         return req;
355 }
356 EXPORT_SYMBOL(p9_tag_lookup);
357 
358 /**
359  * p9_tag_remove - Remove a tag.
360  * @c: Client session.
361  * @r: Request of reference.
362  *
363  * Context: Any context.
364  */
365 static int p9_tag_remove(struct p9_client *c, struct p9_req_t *r)
366 {
367         unsigned long flags;
368         u16 tag = r->tc.tag;
369 
370         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
371         spin_lock_irqsave(&c->lock, flags);
372         idr_remove(&c->reqs, tag);
373         spin_unlock_irqrestore(&c->lock, flags);
374         return p9_req_put(r);
375 }
376 
377 static void p9_req_free(struct kref *ref)
378 {
379         struct p9_req_t *r = container_of(ref, struct p9_req_t, refcount);
380         p9_fcall_fini(&r->tc);
381         p9_fcall_fini(&r->rc);
382         kmem_cache_free(p9_req_cache, r);
383 }
384 
385 int p9_req_put(struct p9_req_t *r)
386 {
387         return kref_put(&r->refcount, p9_req_free);
388 }
389 EXPORT_SYMBOL(p9_req_put);
390 
391 /**
392  * p9_tag_cleanup - cleans up tags structure and reclaims resources
393  * @c:  v9fs client struct
394  *
395  * This frees resources associated with the tags structure
396  *
397  */
398 static void p9_tag_cleanup(struct p9_client *c)
399 {
400         struct p9_req_t *req;
401         int id;
402 
403         rcu_read_lock();
404         idr_for_each_entry(&c->reqs, req, id) {
405                 pr_info("Tag %d still in use\n", id);
406                 if (p9_tag_remove(c, req) == 0)
407                         pr_warn("Packet with tag %d has still references",
408                                 req->tc.tag);
409         }
410         rcu_read_unlock();
411 }
412 
413 /**
414  * p9_client_cb - call back from transport to client
415  * c: client state
416  * req: request received
417  *
418  */
419 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
420 {
421         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc.tag);
422 
423         /*
424          * This barrier is needed to make sure any change made to req before
425          * the status change is visible to another thread
426          */
427         smp_wmb();
428         req->status = status;
429 
430         wake_up(&req->wq);
431         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc.tag);
432         p9_req_put(req);
433 }
434 EXPORT_SYMBOL(p9_client_cb);
435 
436 /**
437  * p9_parse_header - parse header arguments out of a packet
438  * @pdu: packet to parse
439  * @size: size of packet
440  * @type: type of request
441  * @tag: tag of packet
442  * @rewind: set if we need to rewind offset afterwards
443  */
444 
445 int
446 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
447                                                                 int rewind)
448 {
449         int8_t r_type;
450         int16_t r_tag;
451         int32_t r_size;
452         int offset = pdu->offset;
453         int err;
454 
455         pdu->offset = 0;
456 
457         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
458         if (err)
459                 goto rewind_and_exit;
460 
461         if (type)
462                 *type = r_type;
463         if (tag)
464                 *tag = r_tag;
465         if (size)
466                 *size = r_size;
467 
468         if (pdu->size != r_size || r_size < 7) {
469                 err = -EINVAL;
470                 goto rewind_and_exit;
471         }
472 
473         pdu->id = r_type;
474         pdu->tag = r_tag;
475 
476         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
477                  pdu->size, pdu->id, pdu->tag);
478 
479 rewind_and_exit:
480         if (rewind)
481                 pdu->offset = offset;
482         return err;
483 }
484 EXPORT_SYMBOL(p9_parse_header);
485 
486 /**
487  * p9_check_errors - check 9p packet for error return and process it
488  * @c: current client instance
489  * @req: request to parse and check for error conditions
490  *
491  * returns error code if one is discovered, otherwise returns 0
492  *
493  * this will have to be more complicated if we have multiple
494  * error packet types
495  */
496 
497 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
498 {
499         int8_t type;
500         int err;
501         int ecode;
502 
503         err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
504         if (req->rc.size >= c->msize) {
505                 p9_debug(P9_DEBUG_ERROR,
506                          "requested packet size too big: %d\n",
507                          req->rc.size);
508                 return -EIO;
509         }
510         /*
511          * dump the response from server
512          * This should be after check errors which poplulate pdu_fcall.
513          */
514         trace_9p_protocol_dump(c, &req->rc);
515         if (err) {
516                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
517                 return err;
518         }
519         if (type != P9_RERROR && type != P9_RLERROR)
520                 return 0;
521 
522         if (!p9_is_proto_dotl(c)) {
523                 char *ename;
524                 err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
525                                   &ename, &ecode);
526                 if (err)
527                         goto out_err;
528 
529                 if (p9_is_proto_dotu(c) && ecode < 512)
530                         err = -ecode;
531 
532                 if (!err) {
533                         err = p9_errstr2errno(ename, strlen(ename));
534 
535                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
536                                  -ecode, ename);
537                 }
538                 kfree(ename);
539         } else {
540                 err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
541                 err = -ecode;
542 
543                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
544         }
545 
546         return err;
547 
548 out_err:
549         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
550 
551         return err;
552 }
553 
554 /**
555  * p9_check_zc_errors - check 9p packet for error return and process it
556  * @c: current client instance
557  * @req: request to parse and check for error conditions
558  * @in_hdrlen: Size of response protocol buffer.
559  *
560  * returns error code if one is discovered, otherwise returns 0
561  *
562  * this will have to be more complicated if we have multiple
563  * error packet types
564  */
565 
566 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
567                               struct iov_iter *uidata, int in_hdrlen)
568 {
569         int err;
570         int ecode;
571         int8_t type;
572         char *ename = NULL;
573 
574         err = p9_parse_header(&req->rc, NULL, &type, NULL, 0);
575         /*
576          * dump the response from server
577          * This should be after parse_header which poplulate pdu_fcall.
578          */
579         trace_9p_protocol_dump(c, &req->rc);
580         if (err) {
581                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
582                 return err;
583         }
584 
585         if (type != P9_RERROR && type != P9_RLERROR)
586                 return 0;
587 
588         if (!p9_is_proto_dotl(c)) {
589                 /* Error is reported in string format */
590                 int len;
591                 /* 7 = header size for RERROR; */
592                 int inline_len = in_hdrlen - 7;
593 
594                 len = req->rc.size - req->rc.offset;
595                 if (len > (P9_ZC_HDR_SZ - 7)) {
596                         err = -EFAULT;
597                         goto out_err;
598                 }
599 
600                 ename = &req->rc.sdata[req->rc.offset];
601                 if (len > inline_len) {
602                         /* We have error in external buffer */
603                         if (!copy_from_iter_full(ename + inline_len,
604                                              len - inline_len, uidata)) {
605                                 err = -EFAULT;
606                                 goto out_err;
607                         }
608                 }
609                 ename = NULL;
610                 err = p9pdu_readf(&req->rc, c->proto_version, "s?d",
611                                   &ename, &ecode);
612                 if (err)
613                         goto out_err;
614 
615                 if (p9_is_proto_dotu(c) && ecode < 512)
616                         err = -ecode;
617 
618                 if (!err) {
619                         err = p9_errstr2errno(ename, strlen(ename));
620 
621                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
622                                  -ecode, ename);
623                 }
624                 kfree(ename);
625         } else {
626                 err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode);
627                 err = -ecode;
628 
629                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
630         }
631         return err;
632 
633 out_err:
634         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
635         return err;
636 }
637 
638 static struct p9_req_t *
639 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
640 
641 /**
642  * p9_client_flush - flush (cancel) a request
643  * @c: client state
644  * @oldreq: request to cancel
645  *
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.
650  *
651  */
652 
653 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
654 {
655         struct p9_req_t *req;
656         int16_t oldtag;
657         int err;
658 
659         err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1);
660         if (err)
661                 return err;
662 
663         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
664 
665         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
666         if (IS_ERR(req))
667                 return PTR_ERR(req);
668 
669         /*
670          * if we haven't received a response for oldreq,
671          * remove it from the list
672          */
673         if (oldreq->status == REQ_STATUS_SENT) {
674                 if (c->trans_mod->cancelled)
675                         c->trans_mod->cancelled(c, oldreq);
676         }
677 
678         p9_tag_remove(c, req);
679         return 0;
680 }
681 
682 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
683                                               int8_t type, int req_size,
684                                               const char *fmt, va_list ap)
685 {
686         int err;
687         struct p9_req_t *req;
688 
689         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
690 
691         /* we allow for any status other than disconnected */
692         if (c->status == Disconnected)
693                 return ERR_PTR(-EIO);
694 
695         /* if status is begin_disconnected we allow only clunk request */
696         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
697                 return ERR_PTR(-EIO);
698 
699         req = p9_tag_alloc(c, type, req_size);
700         if (IS_ERR(req))
701                 return req;
702 
703         /* marshall the data */
704         p9pdu_prepare(&req->tc, req->tc.tag, type);
705         err = p9pdu_vwritef(&req->tc, c->proto_version, fmt, ap);
706         if (err)
707                 goto reterr;
708         p9pdu_finalize(c, &req->tc);
709         trace_9p_client_req(c, type, req->tc.tag);
710         return req;
711 reterr:
712         p9_tag_remove(c, req);
713         /* We have to put also the 2nd reference as it won't be used */
714         p9_req_put(req);
715         return ERR_PTR(err);
716 }
717 
718 /**
719  * p9_client_rpc - issue a request and wait for a response
720  * @c: client session
721  * @type: type of request
722  * @fmt: protocol format string (see protocol.c)
723  *
724  * Returns request structure (which client must free using p9_tag_remove)
725  */
726 
727 static struct p9_req_t *
728 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
729 {
730         va_list ap;
731         int sigpending, err;
732         unsigned long flags;
733         struct p9_req_t *req;
734 
735         va_start(ap, fmt);
736         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
737         va_end(ap);
738         if (IS_ERR(req))
739                 return req;
740 
741         if (signal_pending(current)) {
742                 sigpending = 1;
743                 clear_thread_flag(TIF_SIGPENDING);
744         } else
745                 sigpending = 0;
746 
747         err = c->trans_mod->request(c, req);
748         if (err < 0) {
749                 /* write won't happen */
750                 p9_req_put(req);
751                 if (err != -ERESTARTSYS && err != -EFAULT)
752                         c->status = Disconnected;
753                 goto recalc_sigpending;
754         }
755 again:
756         /* Wait for the response */
757         err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
758 
759         /*
760          * Make sure our req is coherent with regard to updates in other
761          * threads - echoes to wmb() in the callback
762          */
763         smp_rmb();
764 
765         if ((err == -ERESTARTSYS) && (c->status == Connected)
766                                   && (type == P9_TFLUSH)) {
767                 sigpending = 1;
768                 clear_thread_flag(TIF_SIGPENDING);
769                 goto again;
770         }
771 
772         if (req->status == REQ_STATUS_ERROR) {
773                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
774                 err = req->t_err;
775         }
776         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
777                 p9_debug(P9_DEBUG_MUX, "flushing\n");
778                 sigpending = 1;
779                 clear_thread_flag(TIF_SIGPENDING);
780 
781                 if (c->trans_mod->cancel(c, req))
782                         p9_client_flush(c, req);
783 
784                 /* if we received the response anyway, don't signal error */
785                 if (req->status == REQ_STATUS_RCVD)
786                         err = 0;
787         }
788 recalc_sigpending:
789         if (sigpending) {
790                 spin_lock_irqsave(&current->sighand->siglock, flags);
791                 recalc_sigpending();
792                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
793         }
794         if (err < 0)
795                 goto reterr;
796 
797         err = p9_check_errors(c, req);
798         trace_9p_client_res(c, type, req->rc.tag, err);
799         if (!err)
800                 return req;
801 reterr:
802         p9_tag_remove(c, req);
803         return ERR_PTR(safe_errno(err));
804 }
805 
806 /**
807  * p9_client_zc_rpc - issue a request and wait for a response
808  * @c: client session
809  * @type: type of request
810  * @uidata: destination for zero copy read
811  * @uodata: source for zero copy write
812  * @inlen: read buffer size
813  * @olen: write buffer size
814  * @hdrlen: reader header size, This is the size of response protocol data
815  * @fmt: protocol format string (see protocol.c)
816  *
817  * Returns request structure (which client must free using p9_tag_remove)
818  */
819 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
820                                          struct iov_iter *uidata,
821                                          struct iov_iter *uodata,
822                                          int inlen, int olen, int in_hdrlen,
823                                          const char *fmt, ...)
824 {
825         va_list ap;
826         int sigpending, err;
827         unsigned long flags;
828         struct p9_req_t *req;
829 
830         va_start(ap, fmt);
831         /*
832          * We allocate a inline protocol data of only 4k bytes.
833          * The actual content is passed in zero-copy fashion.
834          */
835         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
836         va_end(ap);
837         if (IS_ERR(req))
838                 return req;
839 
840         if (signal_pending(current)) {
841                 sigpending = 1;
842                 clear_thread_flag(TIF_SIGPENDING);
843         } else
844                 sigpending = 0;
845 
846         err = c->trans_mod->zc_request(c, req, uidata, uodata,
847                                        inlen, olen, in_hdrlen);
848         if (err < 0) {
849                 if (err == -EIO)
850                         c->status = Disconnected;
851                 if (err != -ERESTARTSYS)
852                         goto recalc_sigpending;
853         }
854         if (req->status == REQ_STATUS_ERROR) {
855                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
856                 err = req->t_err;
857         }
858         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
859                 p9_debug(P9_DEBUG_MUX, "flushing\n");
860                 sigpending = 1;
861                 clear_thread_flag(TIF_SIGPENDING);
862 
863                 if (c->trans_mod->cancel(c, req))
864                         p9_client_flush(c, req);
865 
866                 /* if we received the response anyway, don't signal error */
867                 if (req->status == REQ_STATUS_RCVD)
868                         err = 0;
869         }
870 recalc_sigpending:
871         if (sigpending) {
872                 spin_lock_irqsave(&current->sighand->siglock, flags);
873                 recalc_sigpending();
874                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
875         }
876         if (err < 0)
877                 goto reterr;
878 
879         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
880         trace_9p_client_res(c, type, req->rc.tag, err);
881         if (!err)
882                 return req;
883 reterr:
884         p9_tag_remove(c, req);
885         return ERR_PTR(safe_errno(err));
886 }
887 
888 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
889 {
890         int ret;
891         struct p9_fid *fid;
892 
893         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
894         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
895         if (!fid)
896                 return NULL;
897 
898         memset(&fid->qid, 0, sizeof(struct p9_qid));
899         fid->mode = -1;
900         fid->uid = current_fsuid();
901         fid->clnt = clnt;
902         fid->rdir = NULL;
903         fid->fid = 0;
904 
905         idr_preload(GFP_KERNEL);
906         spin_lock_irq(&clnt->lock);
907         ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
908                             GFP_NOWAIT);
909         spin_unlock_irq(&clnt->lock);
910         idr_preload_end();
911 
912         if (!ret)
913                 return fid;
914 
915         kfree(fid);
916         return NULL;
917 }
918 
919 static void p9_fid_destroy(struct p9_fid *fid)
920 {
921         struct p9_client *clnt;
922         unsigned long flags;
923 
924         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
925         clnt = fid->clnt;
926         spin_lock_irqsave(&clnt->lock, flags);
927         idr_remove(&clnt->fids, fid->fid);
928         spin_unlock_irqrestore(&clnt->lock, flags);
929         kfree(fid->rdir);
930         kfree(fid);
931 }
932 
933 static int p9_client_version(struct p9_client *c)
934 {
935         int err = 0;
936         struct p9_req_t *req;
937         char *version = NULL;
938         int msize;
939 
940         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
941                  c->msize, c->proto_version);
942 
943         switch (c->proto_version) {
944         case p9_proto_2000L:
945                 req = p9_client_rpc(c, P9_TVERSION, "ds",
946                                         c->msize, "9P2000.L");
947                 break;
948         case p9_proto_2000u:
949                 req = p9_client_rpc(c, P9_TVERSION, "ds",
950                                         c->msize, "9P2000.u");
951                 break;
952         case p9_proto_legacy:
953                 req = p9_client_rpc(c, P9_TVERSION, "ds",
954                                         c->msize, "9P2000");
955                 break;
956         default:
957                 return -EINVAL;
958         }
959 
960         if (IS_ERR(req))
961                 return PTR_ERR(req);
962 
963         err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version);
964         if (err) {
965                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
966                 trace_9p_protocol_dump(c, &req->rc);
967                 goto error;
968         }
969 
970         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
971         if (!strncmp(version, "9P2000.L", 8))
972                 c->proto_version = p9_proto_2000L;
973         else if (!strncmp(version, "9P2000.u", 8))
974                 c->proto_version = p9_proto_2000u;
975         else if (!strncmp(version, "9P2000", 6))
976                 c->proto_version = p9_proto_legacy;
977         else {
978                 p9_debug(P9_DEBUG_ERROR,
979                          "server returned an unknown version: %s\n", version);
980                 err = -EREMOTEIO;
981                 goto error;
982         }
983 
984         if (msize < 4096) {
985                 p9_debug(P9_DEBUG_ERROR,
986                          "server returned a msize < 4096: %d\n", msize);
987                 err = -EREMOTEIO;
988                 goto error;
989         }
990         if (msize < c->msize)
991                 c->msize = msize;
992 
993 error:
994         kfree(version);
995         p9_tag_remove(c, req);
996 
997         return err;
998 }
999 
1000 struct p9_client *p9_client_create(const char *dev_name, char *options)
1001 {
1002         int err;
1003         struct p9_client *clnt;
1004         char *client_id;
1005 
1006         err = 0;
1007         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1008         if (!clnt)
1009                 return ERR_PTR(-ENOMEM);
1010 
1011         clnt->trans_mod = NULL;
1012         clnt->trans = NULL;
1013         clnt->fcall_cache = NULL;
1014 
1015         client_id = utsname()->nodename;
1016         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1017 
1018         spin_lock_init(&clnt->lock);
1019         idr_init(&clnt->fids);
1020         idr_init(&clnt->reqs);
1021 
1022         err = parse_opts(options, clnt);
1023         if (err < 0)
1024                 goto free_client;
1025 
1026         if (!clnt->trans_mod)
1027                 clnt->trans_mod = v9fs_get_default_trans();
1028 
1029         if (clnt->trans_mod == NULL) {
1030                 err = -EPROTONOSUPPORT;
1031                 p9_debug(P9_DEBUG_ERROR,
1032                          "No transport defined or default transport\n");
1033                 goto free_client;
1034         }
1035 
1036         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1037                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1038 
1039         err = clnt->trans_mod->create(clnt, dev_name, options);
1040         if (err)
1041                 goto put_trans;
1042 
1043         if (clnt->msize > clnt->trans_mod->maxsize)
1044                 clnt->msize = clnt->trans_mod->maxsize;
1045 
1046         if (clnt->msize < 4096) {
1047                 p9_debug(P9_DEBUG_ERROR,
1048                          "Please specify a msize of at least 4k\n");
1049                 err = -EINVAL;
1050                 goto close_trans;
1051         }
1052 
1053         err = p9_client_version(clnt);
1054         if (err)
1055                 goto close_trans;
1056 
1057         /* P9_HDRSZ + 4 is the smallest packet header we can have that is
1058          * followed by data accessed from userspace by read
1059          */
1060         clnt->fcall_cache =
1061                 kmem_cache_create_usercopy("9p-fcall-cache", clnt->msize,
1062                                            0, 0, P9_HDRSZ + 4,
1063                                            clnt->msize - (P9_HDRSZ + 4),
1064                                            NULL);
1065 
1066         return clnt;
1067 
1068 close_trans:
1069         clnt->trans_mod->close(clnt);
1070 put_trans:
1071         v9fs_put_trans(clnt->trans_mod);
1072 free_client:
1073         kfree(clnt);
1074         return ERR_PTR(err);
1075 }
1076 EXPORT_SYMBOL(p9_client_create);
1077 
1078 void p9_client_destroy(struct p9_client *clnt)
1079 {
1080         struct p9_fid *fid;
1081         int id;
1082 
1083         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1084 
1085         if (clnt->trans_mod)
1086                 clnt->trans_mod->close(clnt);
1087 
1088         v9fs_put_trans(clnt->trans_mod);
1089 
1090         idr_for_each_entry(&clnt->fids, fid, id) {
1091                 pr_info("Found fid %d not clunked\n", fid->fid);
1092                 p9_fid_destroy(fid);
1093         }
1094 
1095         p9_tag_cleanup(clnt);
1096 
1097         kmem_cache_destroy(clnt->fcall_cache);
1098         kfree(clnt);
1099 }
1100 EXPORT_SYMBOL(p9_client_destroy);
1101 
1102 void p9_client_disconnect(struct p9_client *clnt)
1103 {
1104         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1105         clnt->status = Disconnected;
1106 }
1107 EXPORT_SYMBOL(p9_client_disconnect);
1108 
1109 void p9_client_begin_disconnect(struct p9_client *clnt)
1110 {
1111         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1112         clnt->status = BeginDisconnect;
1113 }
1114 EXPORT_SYMBOL(p9_client_begin_disconnect);
1115 
1116 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1117         const char *uname, kuid_t n_uname, const char *aname)
1118 {
1119         int err = 0;
1120         struct p9_req_t *req;
1121         struct p9_fid *fid;
1122         struct p9_qid qid;
1123 
1124 
1125         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1126                  afid ? afid->fid : -1, uname, aname);
1127         fid = p9_fid_create(clnt);
1128         if (!fid) {
1129                 err = -ENOMEM;
1130                 goto error;
1131         }
1132         fid->uid = n_uname;
1133 
1134         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1135                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1136         if (IS_ERR(req)) {
1137                 err = PTR_ERR(req);
1138                 goto error;
1139         }
1140 
1141         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid);
1142         if (err) {
1143                 trace_9p_protocol_dump(clnt, &req->rc);
1144                 p9_tag_remove(clnt, req);
1145                 goto error;
1146         }
1147 
1148         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1149                  qid.type, (unsigned long long)qid.path, qid.version);
1150 
1151         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1152 
1153         p9_tag_remove(clnt, req);
1154         return fid;
1155 
1156 error:
1157         if (fid)
1158                 p9_fid_destroy(fid);
1159         return ERR_PTR(err);
1160 }
1161 EXPORT_SYMBOL(p9_client_attach);
1162 
1163 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1164                 const unsigned char * const *wnames, int clone)
1165 {
1166         int err;
1167         struct p9_client *clnt;
1168         struct p9_fid *fid;
1169         struct p9_qid *wqids;
1170         struct p9_req_t *req;
1171         uint16_t nwqids, count;
1172 
1173         err = 0;
1174         wqids = NULL;
1175         clnt = oldfid->clnt;
1176         if (clone) {
1177                 fid = p9_fid_create(clnt);
1178                 if (!fid) {
1179                         err = -ENOMEM;
1180                         goto error;
1181                 }
1182 
1183                 fid->uid = oldfid->uid;
1184         } else
1185                 fid = oldfid;
1186 
1187 
1188         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1189                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1190 
1191         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1192                                                                 nwname, wnames);
1193         if (IS_ERR(req)) {
1194                 err = PTR_ERR(req);
1195                 goto error;
1196         }
1197 
1198         err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1199         if (err) {
1200                 trace_9p_protocol_dump(clnt, &req->rc);
1201                 p9_tag_remove(clnt, req);
1202                 goto clunk_fid;
1203         }
1204         p9_tag_remove(clnt, req);
1205 
1206         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1207 
1208         if (nwqids != nwname) {
1209                 err = -ENOENT;
1210                 goto clunk_fid;
1211         }
1212 
1213         for (count = 0; count < nwqids; count++)
1214                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1215                         count, wqids[count].type,
1216                         (unsigned long long)wqids[count].path,
1217                         wqids[count].version);
1218 
1219         if (nwname)
1220                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1221         else
1222                 fid->qid = oldfid->qid;
1223 
1224         kfree(wqids);
1225         return fid;
1226 
1227 clunk_fid:
1228         kfree(wqids);
1229         p9_client_clunk(fid);
1230         fid = NULL;
1231 
1232 error:
1233         if (fid && (fid != oldfid))
1234                 p9_fid_destroy(fid);
1235 
1236         return ERR_PTR(err);
1237 }
1238 EXPORT_SYMBOL(p9_client_walk);
1239 
1240 int p9_client_open(struct p9_fid *fid, int mode)
1241 {
1242         int err;
1243         struct p9_client *clnt;
1244         struct p9_req_t *req;
1245         struct p9_qid qid;
1246         int iounit;
1247 
1248         clnt = fid->clnt;
1249         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1250                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1251         err = 0;
1252 
1253         if (fid->mode != -1)
1254                 return -EINVAL;
1255 
1256         if (p9_is_proto_dotl(clnt))
1257                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1258         else
1259                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1260         if (IS_ERR(req)) {
1261                 err = PTR_ERR(req);
1262                 goto error;
1263         }
1264 
1265         err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1266         if (err) {
1267                 trace_9p_protocol_dump(clnt, &req->rc);
1268                 goto free_and_error;
1269         }
1270 
1271         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1272                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1273                 (unsigned long long)qid.path, qid.version, iounit);
1274 
1275         fid->mode = mode;
1276         fid->iounit = iounit;
1277 
1278 free_and_error:
1279         p9_tag_remove(clnt, req);
1280 error:
1281         return err;
1282 }
1283 EXPORT_SYMBOL(p9_client_open);
1284 
1285 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1286                 kgid_t gid, struct p9_qid *qid)
1287 {
1288         int err = 0;
1289         struct p9_client *clnt;
1290         struct p9_req_t *req;
1291         int iounit;
1292 
1293         p9_debug(P9_DEBUG_9P,
1294                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1295                         ofid->fid, name, flags, mode,
1296                         from_kgid(&init_user_ns, gid));
1297         clnt = ofid->clnt;
1298 
1299         if (ofid->mode != -1)
1300                 return -EINVAL;
1301 
1302         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1303                         mode, gid);
1304         if (IS_ERR(req)) {
1305                 err = PTR_ERR(req);
1306                 goto error;
1307         }
1308 
1309         err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit);
1310         if (err) {
1311                 trace_9p_protocol_dump(clnt, &req->rc);
1312                 goto free_and_error;
1313         }
1314 
1315         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1316                         qid->type,
1317                         (unsigned long long)qid->path,
1318                         qid->version, iounit);
1319 
1320         ofid->mode = mode;
1321         ofid->iounit = iounit;
1322 
1323 free_and_error:
1324         p9_tag_remove(clnt, req);
1325 error:
1326         return err;
1327 }
1328 EXPORT_SYMBOL(p9_client_create_dotl);
1329 
1330 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1331                      char *extension)
1332 {
1333         int err;
1334         struct p9_client *clnt;
1335         struct p9_req_t *req;
1336         struct p9_qid qid;
1337         int iounit;
1338 
1339         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1340                                                 fid->fid, name, perm, mode);
1341         err = 0;
1342         clnt = fid->clnt;
1343 
1344         if (fid->mode != -1)
1345                 return -EINVAL;
1346 
1347         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1348                                 mode, extension);
1349         if (IS_ERR(req)) {
1350                 err = PTR_ERR(req);
1351                 goto error;
1352         }
1353 
1354         err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1355         if (err) {
1356                 trace_9p_protocol_dump(clnt, &req->rc);
1357                 goto free_and_error;
1358         }
1359 
1360         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1361                                 qid.type,
1362                                 (unsigned long long)qid.path,
1363                                 qid.version, iounit);
1364 
1365         fid->mode = mode;
1366         fid->iounit = iounit;
1367 
1368 free_and_error:
1369         p9_tag_remove(clnt, req);
1370 error:
1371         return err;
1372 }
1373 EXPORT_SYMBOL(p9_client_fcreate);
1374 
1375 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1376                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1377 {
1378         int err = 0;
1379         struct p9_client *clnt;
1380         struct p9_req_t *req;
1381 
1382         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1383                         dfid->fid, name, symtgt);
1384         clnt = dfid->clnt;
1385 
1386         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1387                         gid);
1388         if (IS_ERR(req)) {
1389                 err = PTR_ERR(req);
1390                 goto error;
1391         }
1392 
1393         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
1394         if (err) {
1395                 trace_9p_protocol_dump(clnt, &req->rc);
1396                 goto free_and_error;
1397         }
1398 
1399         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1400                         qid->type, (unsigned long long)qid->path, qid->version);
1401 
1402 free_and_error:
1403         p9_tag_remove(clnt, req);
1404 error:
1405         return err;
1406 }
1407 EXPORT_SYMBOL(p9_client_symlink);
1408 
1409 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1410 {
1411         struct p9_client *clnt;
1412         struct p9_req_t *req;
1413 
1414         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1415                         dfid->fid, oldfid->fid, newname);
1416         clnt = dfid->clnt;
1417         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1418                         newname);
1419         if (IS_ERR(req))
1420                 return PTR_ERR(req);
1421 
1422         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1423         p9_tag_remove(clnt, req);
1424         return 0;
1425 }
1426 EXPORT_SYMBOL(p9_client_link);
1427 
1428 int p9_client_fsync(struct p9_fid *fid, int datasync)
1429 {
1430         int err;
1431         struct p9_client *clnt;
1432         struct p9_req_t *req;
1433 
1434         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1435                         fid->fid, datasync);
1436         err = 0;
1437         clnt = fid->clnt;
1438 
1439         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1440         if (IS_ERR(req)) {
1441                 err = PTR_ERR(req);
1442                 goto error;
1443         }
1444 
1445         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1446 
1447         p9_tag_remove(clnt, req);
1448 
1449 error:
1450         return err;
1451 }
1452 EXPORT_SYMBOL(p9_client_fsync);
1453 
1454 int p9_client_clunk(struct p9_fid *fid)
1455 {
1456         int err;
1457         struct p9_client *clnt;
1458         struct p9_req_t *req;
1459         int retries = 0;
1460 
1461         if (!fid) {
1462                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1463                         __func__, task_pid_nr(current));
1464                 dump_stack();
1465                 return 0;
1466         }
1467 
1468 again:
1469         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1470                                                                 retries);
1471         err = 0;
1472         clnt = fid->clnt;
1473 
1474         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1475         if (IS_ERR(req)) {
1476                 err = PTR_ERR(req);
1477                 goto error;
1478         }
1479 
1480         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1481 
1482         p9_tag_remove(clnt, req);
1483 error:
1484         /*
1485          * Fid is not valid even after a failed clunk
1486          * If interrupted, retry once then give up and
1487          * leak fid until umount.
1488          */
1489         if (err == -ERESTARTSYS) {
1490                 if (retries++ == 0)
1491                         goto again;
1492         } else
1493                 p9_fid_destroy(fid);
1494         return err;
1495 }
1496 EXPORT_SYMBOL(p9_client_clunk);
1497 
1498 int p9_client_remove(struct p9_fid *fid)
1499 {
1500         int err;
1501         struct p9_client *clnt;
1502         struct p9_req_t *req;
1503 
1504         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1505         err = 0;
1506         clnt = fid->clnt;
1507 
1508         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1509         if (IS_ERR(req)) {
1510                 err = PTR_ERR(req);
1511                 goto error;
1512         }
1513 
1514         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1515 
1516         p9_tag_remove(clnt, req);
1517 error:
1518         if (err == -ERESTARTSYS)
1519                 p9_client_clunk(fid);
1520         else
1521                 p9_fid_destroy(fid);
1522         return err;
1523 }
1524 EXPORT_SYMBOL(p9_client_remove);
1525 
1526 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1527 {
1528         int err = 0;
1529         struct p9_req_t *req;
1530         struct p9_client *clnt;
1531 
1532         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1533                    dfid->fid, name, flags);
1534 
1535         clnt = dfid->clnt;
1536         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1537         if (IS_ERR(req)) {
1538                 err = PTR_ERR(req);
1539                 goto error;
1540         }
1541         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1542 
1543         p9_tag_remove(clnt, req);
1544 error:
1545         return err;
1546 }
1547 EXPORT_SYMBOL(p9_client_unlinkat);
1548 
1549 int
1550 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1551 {
1552         struct p9_client *clnt = fid->clnt;
1553         struct p9_req_t *req;
1554         int total = 0;
1555         *err = 0;
1556 
1557         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1558                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1559 
1560         while (iov_iter_count(to)) {
1561                 int count = iov_iter_count(to);
1562                 int rsize, non_zc = 0;
1563                 char *dataptr;
1564 
1565                 rsize = fid->iounit;
1566                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1567                         rsize = clnt->msize - P9_IOHDRSZ;
1568 
1569                 if (count < rsize)
1570                         rsize = count;
1571 
1572                 /* Don't bother zerocopy for small IO (< 1024) */
1573                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1574                         /*
1575                          * response header len is 11
1576                          * PDU Header(7) + IO Size (4)
1577                          */
1578                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1579                                                0, 11, "dqd", fid->fid,
1580                                                offset, rsize);
1581                 } else {
1582                         non_zc = 1;
1583                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1584                                             rsize);
1585                 }
1586                 if (IS_ERR(req)) {
1587                         *err = PTR_ERR(req);
1588                         break;
1589                 }
1590 
1591                 *err = p9pdu_readf(&req->rc, clnt->proto_version,
1592                                    "D", &count, &dataptr);
1593                 if (*err) {
1594                         trace_9p_protocol_dump(clnt, &req->rc);
1595                         p9_tag_remove(clnt, req);
1596                         break;
1597                 }
1598                 if (rsize < count) {
1599                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1600                         count = rsize;
1601                 }
1602 
1603                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1604                 if (!count) {
1605                         p9_tag_remove(clnt, req);
1606                         break;
1607                 }
1608 
1609                 if (non_zc) {
1610                         int n = copy_to_iter(dataptr, count, to);
1611                         total += n;
1612                         offset += n;
1613                         if (n != count) {
1614                                 *err = -EFAULT;
1615                                 p9_tag_remove(clnt, req);
1616                                 break;
1617                         }
1618                 } else {
1619                         iov_iter_advance(to, count);
1620                         total += count;
1621                         offset += count;
1622                 }
1623                 p9_tag_remove(clnt, req);
1624         }
1625         return total;
1626 }
1627 EXPORT_SYMBOL(p9_client_read);
1628 
1629 int
1630 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1631 {
1632         struct p9_client *clnt = fid->clnt;
1633         struct p9_req_t *req;
1634         int total = 0;
1635         *err = 0;
1636 
1637         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1638                                 fid->fid, (unsigned long long) offset,
1639                                 iov_iter_count(from));
1640 
1641         while (iov_iter_count(from)) {
1642                 int count = iov_iter_count(from);
1643                 int rsize = fid->iounit;
1644                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1645                         rsize = clnt->msize - P9_IOHDRSZ;
1646 
1647                 if (count < rsize)
1648                         rsize = count;
1649 
1650                 /* Don't bother zerocopy for small IO (< 1024) */
1651                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1652                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1653                                                rsize, P9_ZC_HDR_SZ, "dqd",
1654                                                fid->fid, offset, rsize);
1655                 } else {
1656                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1657                                                     offset, rsize, from);
1658                 }
1659                 if (IS_ERR(req)) {
1660                         *err = PTR_ERR(req);
1661                         break;
1662                 }
1663 
1664                 *err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &count);
1665                 if (*err) {
1666                         trace_9p_protocol_dump(clnt, &req->rc);
1667                         p9_tag_remove(clnt, req);
1668                         break;
1669                 }
1670                 if (rsize < count) {
1671                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1672                         count = rsize;
1673                 }
1674 
1675                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1676 
1677                 p9_tag_remove(clnt, req);
1678                 iov_iter_advance(from, count);
1679                 total += count;
1680                 offset += count;
1681         }
1682         return total;
1683 }
1684 EXPORT_SYMBOL(p9_client_write);
1685 
1686 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1687 {
1688         int err;
1689         struct p9_client *clnt;
1690         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1691         struct p9_req_t *req;
1692         u16 ignored;
1693 
1694         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1695 
1696         if (!ret)
1697                 return ERR_PTR(-ENOMEM);
1698 
1699         err = 0;
1700         clnt = fid->clnt;
1701 
1702         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1703         if (IS_ERR(req)) {
1704                 err = PTR_ERR(req);
1705                 goto error;
1706         }
1707 
1708         err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret);
1709         if (err) {
1710                 trace_9p_protocol_dump(clnt, &req->rc);
1711                 p9_tag_remove(clnt, req);
1712                 goto error;
1713         }
1714 
1715         p9_debug(P9_DEBUG_9P,
1716                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1717                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1718                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1719                 "<<<    uid=%d gid=%d n_muid=%d\n",
1720                 ret->size, ret->type, ret->dev, ret->qid.type,
1721                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1722                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1723                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1724                 from_kuid(&init_user_ns, ret->n_uid),
1725                 from_kgid(&init_user_ns, ret->n_gid),
1726                 from_kuid(&init_user_ns, ret->n_muid));
1727 
1728         p9_tag_remove(clnt, req);
1729         return ret;
1730 
1731 error:
1732         kfree(ret);
1733         return ERR_PTR(err);
1734 }
1735 EXPORT_SYMBOL(p9_client_stat);
1736 
1737 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1738                                                         u64 request_mask)
1739 {
1740         int err;
1741         struct p9_client *clnt;
1742         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1743                                                                 GFP_KERNEL);
1744         struct p9_req_t *req;
1745 
1746         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1747                                                         fid->fid, request_mask);
1748 
1749         if (!ret)
1750                 return ERR_PTR(-ENOMEM);
1751 
1752         err = 0;
1753         clnt = fid->clnt;
1754 
1755         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1756         if (IS_ERR(req)) {
1757                 err = PTR_ERR(req);
1758                 goto error;
1759         }
1760 
1761         err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret);
1762         if (err) {
1763                 trace_9p_protocol_dump(clnt, &req->rc);
1764                 p9_tag_remove(clnt, req);
1765                 goto error;
1766         }
1767 
1768         p9_debug(P9_DEBUG_9P,
1769                 "<<< RGETATTR st_result_mask=%lld\n"
1770                 "<<< qid=%x.%llx.%x\n"
1771                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1772                 "<<< st_uid=%d st_gid=%d\n"
1773                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1774                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1775                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1776                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1777                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1778                 "<<< st_gen=%lld st_data_version=%lld\n",
1779                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1780                 ret->qid.version, ret->st_mode, ret->st_nlink,
1781                 from_kuid(&init_user_ns, ret->st_uid),
1782                 from_kgid(&init_user_ns, ret->st_gid),
1783                 ret->st_rdev, ret->st_size, ret->st_blksize,
1784                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1785                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1786                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1787                 ret->st_gen, ret->st_data_version);
1788 
1789         p9_tag_remove(clnt, req);
1790         return ret;
1791 
1792 error:
1793         kfree(ret);
1794         return ERR_PTR(err);
1795 }
1796 EXPORT_SYMBOL(p9_client_getattr_dotl);
1797 
1798 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1799 {
1800         int ret;
1801 
1802         /* NOTE: size shouldn't include its own length */
1803         /* size[2] type[2] dev[4] qid[13] */
1804         /* mode[4] atime[4] mtime[4] length[8]*/
1805         /* name[s] uid[s] gid[s] muid[s] */
1806         ret = 2+4+13+4+4+4+8+2+2+2+2;
1807 
1808         if (wst->name)
1809                 ret += strlen(wst->name);
1810         if (wst->uid)
1811                 ret += strlen(wst->uid);
1812         if (wst->gid)
1813                 ret += strlen(wst->gid);
1814         if (wst->muid)
1815                 ret += strlen(wst->muid);
1816 
1817         if ((proto_version == p9_proto_2000u) ||
1818                 (proto_version == p9_proto_2000L)) {
1819                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1820                 if (wst->extension)
1821                         ret += strlen(wst->extension);
1822         }
1823 
1824         return ret;
1825 }
1826 
1827 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1828 {
1829         int err;
1830         struct p9_req_t *req;
1831         struct p9_client *clnt;
1832 
1833         err = 0;
1834         clnt = fid->clnt;
1835         wst->size = p9_client_statsize(wst, clnt->proto_version);
1836         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1837         p9_debug(P9_DEBUG_9P,
1838                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1839                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1840                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1841                 "     uid=%d gid=%d n_muid=%d\n",
1842                 wst->size, wst->type, wst->dev, wst->qid.type,
1843                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1844                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1845                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1846                 from_kuid(&init_user_ns, wst->n_uid),
1847                 from_kgid(&init_user_ns, wst->n_gid),
1848                 from_kuid(&init_user_ns, wst->n_muid));
1849 
1850         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1851         if (IS_ERR(req)) {
1852                 err = PTR_ERR(req);
1853                 goto error;
1854         }
1855 
1856         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1857 
1858         p9_tag_remove(clnt, req);
1859 error:
1860         return err;
1861 }
1862 EXPORT_SYMBOL(p9_client_wstat);
1863 
1864 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1865 {
1866         int err;
1867         struct p9_req_t *req;
1868         struct p9_client *clnt;
1869 
1870         err = 0;
1871         clnt = fid->clnt;
1872         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1873         p9_debug(P9_DEBUG_9P,
1874                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1875                 "    atime_sec=%lld atime_nsec=%lld\n"
1876                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1877                 p9attr->valid, p9attr->mode,
1878                 from_kuid(&init_user_ns, p9attr->uid),
1879                 from_kgid(&init_user_ns, p9attr->gid),
1880                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1881                 p9attr->mtime_sec, p9attr->mtime_nsec);
1882 
1883         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1884 
1885         if (IS_ERR(req)) {
1886                 err = PTR_ERR(req);
1887                 goto error;
1888         }
1889         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1890         p9_tag_remove(clnt, req);
1891 error:
1892         return err;
1893 }
1894 EXPORT_SYMBOL(p9_client_setattr);
1895 
1896 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1897 {
1898         int err;
1899         struct p9_req_t *req;
1900         struct p9_client *clnt;
1901 
1902         err = 0;
1903         clnt = fid->clnt;
1904 
1905         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1906 
1907         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1908         if (IS_ERR(req)) {
1909                 err = PTR_ERR(req);
1910                 goto error;
1911         }
1912 
1913         err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1914                           &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1915                           &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1916         if (err) {
1917                 trace_9p_protocol_dump(clnt, &req->rc);
1918                 p9_tag_remove(clnt, req);
1919                 goto error;
1920         }
1921 
1922         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1923                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1924                 "fsid %llu namelen %ld\n",
1925                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1926                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1927                 sb->fsid, (long int)sb->namelen);
1928 
1929         p9_tag_remove(clnt, req);
1930 error:
1931         return err;
1932 }
1933 EXPORT_SYMBOL(p9_client_statfs);
1934 
1935 int p9_client_rename(struct p9_fid *fid,
1936                      struct p9_fid *newdirfid, const char *name)
1937 {
1938         int err;
1939         struct p9_req_t *req;
1940         struct p9_client *clnt;
1941 
1942         err = 0;
1943         clnt = fid->clnt;
1944 
1945         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1946                         fid->fid, newdirfid->fid, name);
1947 
1948         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1949                         newdirfid->fid, name);
1950         if (IS_ERR(req)) {
1951                 err = PTR_ERR(req);
1952                 goto error;
1953         }
1954 
1955         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1956 
1957         p9_tag_remove(clnt, req);
1958 error:
1959         return err;
1960 }
1961 EXPORT_SYMBOL(p9_client_rename);
1962 
1963 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1964                        struct p9_fid *newdirfid, const char *new_name)
1965 {
1966         int err;
1967         struct p9_req_t *req;
1968         struct p9_client *clnt;
1969 
1970         err = 0;
1971         clnt = olddirfid->clnt;
1972 
1973         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1974                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1975                    newdirfid->fid, new_name);
1976 
1977         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1978                             old_name, newdirfid->fid, new_name);
1979         if (IS_ERR(req)) {
1980                 err = PTR_ERR(req);
1981                 goto error;
1982         }
1983 
1984         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1985                    newdirfid->fid, new_name);
1986 
1987         p9_tag_remove(clnt, req);
1988 error:
1989         return err;
1990 }
1991 EXPORT_SYMBOL(p9_client_renameat);
1992 
1993 /*
1994  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1995  */
1996 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1997                                 const char *attr_name, u64 *attr_size)
1998 {
1999         int err;
2000         struct p9_req_t *req;
2001         struct p9_client *clnt;
2002         struct p9_fid *attr_fid;
2003 
2004         err = 0;
2005         clnt = file_fid->clnt;
2006         attr_fid = p9_fid_create(clnt);
2007         if (!attr_fid) {
2008                 err = -ENOMEM;
2009                 goto error;
2010         }
2011         p9_debug(P9_DEBUG_9P,
2012                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2013                 file_fid->fid, attr_fid->fid, attr_name);
2014 
2015         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2016                         file_fid->fid, attr_fid->fid, attr_name);
2017         if (IS_ERR(req)) {
2018                 err = PTR_ERR(req);
2019                 goto error;
2020         }
2021         err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size);
2022         if (err) {
2023                 trace_9p_protocol_dump(clnt, &req->rc);
2024                 p9_tag_remove(clnt, req);
2025                 goto clunk_fid;
2026         }
2027         p9_tag_remove(clnt, req);
2028         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2029                 attr_fid->fid, *attr_size);
2030         return attr_fid;
2031 clunk_fid:
2032         p9_client_clunk(attr_fid);
2033         attr_fid = NULL;
2034 error:
2035         if (attr_fid && (attr_fid != file_fid))
2036                 p9_fid_destroy(attr_fid);
2037 
2038         return ERR_PTR(err);
2039 }
2040 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2041 
2042 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2043                         u64 attr_size, int flags)
2044 {
2045         int err;
2046         struct p9_req_t *req;
2047         struct p9_client *clnt;
2048 
2049         p9_debug(P9_DEBUG_9P,
2050                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2051                 fid->fid, name, (long long)attr_size, flags);
2052         err = 0;
2053         clnt = fid->clnt;
2054         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2055                         fid->fid, name, attr_size, flags);
2056         if (IS_ERR(req)) {
2057                 err = PTR_ERR(req);
2058                 goto error;
2059         }
2060         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2061         p9_tag_remove(clnt, req);
2062 error:
2063         return err;
2064 }
2065 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2066 
2067 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2068 {
2069         int err, rsize, non_zc = 0;
2070         struct p9_client *clnt;
2071         struct p9_req_t *req;
2072         char *dataptr;
2073         struct kvec kv = {.iov_base = data, .iov_len = count};
2074         struct iov_iter to;
2075 
2076         iov_iter_kvec(&to, READ, &kv, 1, count);
2077 
2078         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2079                                 fid->fid, (unsigned long long) offset, count);
2080 
2081         err = 0;
2082         clnt = fid->clnt;
2083 
2084         rsize = fid->iounit;
2085         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2086                 rsize = clnt->msize - P9_READDIRHDRSZ;
2087 
2088         if (count < rsize)
2089                 rsize = count;
2090 
2091         /* Don't bother zerocopy for small IO (< 1024) */
2092         if (clnt->trans_mod->zc_request && rsize > 1024) {
2093                 /*
2094                  * response header len is 11
2095                  * PDU Header(7) + IO Size (4)
2096                  */
2097                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2098                                        11, "dqd", fid->fid, offset, rsize);
2099         } else {
2100                 non_zc = 1;
2101                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2102                                     offset, rsize);
2103         }
2104         if (IS_ERR(req)) {
2105                 err = PTR_ERR(req);
2106                 goto error;
2107         }
2108 
2109         err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr);
2110         if (err) {
2111                 trace_9p_protocol_dump(clnt, &req->rc);
2112                 goto free_and_error;
2113         }
2114         if (rsize < count) {
2115                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2116                 count = rsize;
2117         }
2118 
2119         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2120 
2121         if (non_zc)
2122                 memmove(data, dataptr, count);
2123 
2124         p9_tag_remove(clnt, req);
2125         return count;
2126 
2127 free_and_error:
2128         p9_tag_remove(clnt, req);
2129 error:
2130         return err;
2131 }
2132 EXPORT_SYMBOL(p9_client_readdir);
2133 
2134 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2135                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2136 {
2137         int err;
2138         struct p9_client *clnt;
2139         struct p9_req_t *req;
2140 
2141         err = 0;
2142         clnt = fid->clnt;
2143         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2144                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2145         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2146                 MAJOR(rdev), MINOR(rdev), gid);
2147         if (IS_ERR(req))
2148                 return PTR_ERR(req);
2149 
2150         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2151         if (err) {
2152                 trace_9p_protocol_dump(clnt, &req->rc);
2153                 goto error;
2154         }
2155         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2156                                 (unsigned long long)qid->path, qid->version);
2157 
2158 error:
2159         p9_tag_remove(clnt, req);
2160         return err;
2161 
2162 }
2163 EXPORT_SYMBOL(p9_client_mknod_dotl);
2164 
2165 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2166                                 kgid_t gid, struct p9_qid *qid)
2167 {
2168         int err;
2169         struct p9_client *clnt;
2170         struct p9_req_t *req;
2171 
2172         err = 0;
2173         clnt = fid->clnt;
2174         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2175                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2176         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2177                 gid);
2178         if (IS_ERR(req))
2179                 return PTR_ERR(req);
2180 
2181         err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid);
2182         if (err) {
2183                 trace_9p_protocol_dump(clnt, &req->rc);
2184                 goto error;
2185         }
2186         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2187                                 (unsigned long long)qid->path, qid->version);
2188 
2189 error:
2190         p9_tag_remove(clnt, req);
2191         return err;
2192 
2193 }
2194 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2195 
2196 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2197 {
2198         int err;
2199         struct p9_client *clnt;
2200         struct p9_req_t *req;
2201 
2202         err = 0;
2203         clnt = fid->clnt;
2204         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2205                         "start %lld length %lld proc_id %d client_id %s\n",
2206                         fid->fid, flock->type, flock->flags, flock->start,
2207                         flock->length, flock->proc_id, flock->client_id);
2208 
2209         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2210                                 flock->flags, flock->start, flock->length,
2211                                         flock->proc_id, flock->client_id);
2212 
2213         if (IS_ERR(req))
2214                 return PTR_ERR(req);
2215 
2216         err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status);
2217         if (err) {
2218                 trace_9p_protocol_dump(clnt, &req->rc);
2219                 goto error;
2220         }
2221         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2222 error:
2223         p9_tag_remove(clnt, req);
2224         return err;
2225 
2226 }
2227 EXPORT_SYMBOL(p9_client_lock_dotl);
2228 
2229 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2230 {
2231         int err;
2232         struct p9_client *clnt;
2233         struct p9_req_t *req;
2234 
2235         err = 0;
2236         clnt = fid->clnt;
2237         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2238                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2239                 glock->start, glock->length, glock->proc_id, glock->client_id);
2240 
2241         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2242                 glock->start, glock->length, glock->proc_id, glock->client_id);
2243 
2244         if (IS_ERR(req))
2245                 return PTR_ERR(req);
2246 
2247         err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type,
2248                           &glock->start, &glock->length, &glock->proc_id,
2249                           &glock->client_id);
2250         if (err) {
2251                 trace_9p_protocol_dump(clnt, &req->rc);
2252                 goto error;
2253         }
2254         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2255                 "proc_id %d client_id %s\n", glock->type, glock->start,
2256                 glock->length, glock->proc_id, glock->client_id);
2257 error:
2258         p9_tag_remove(clnt, req);
2259         return err;
2260 }
2261 EXPORT_SYMBOL(p9_client_getlock_dotl);
2262 
2263 int p9_client_readlink(struct p9_fid *fid, char **target)
2264 {
2265         int err;
2266         struct p9_client *clnt;
2267         struct p9_req_t *req;
2268 
2269         err = 0;
2270         clnt = fid->clnt;
2271         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2272 
2273         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2274         if (IS_ERR(req))
2275                 return PTR_ERR(req);
2276 
2277         err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target);
2278         if (err) {
2279                 trace_9p_protocol_dump(clnt, &req->rc);
2280                 goto error;
2281         }
2282         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2283 error:
2284         p9_tag_remove(clnt, req);
2285         return err;
2286 }
2287 EXPORT_SYMBOL(p9_client_readlink);
2288 
2289 int __init p9_client_init(void)
2290 {
2291         p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU);
2292         return p9_req_cache ? 0 : -ENOMEM;
2293 }
2294 
2295 void __exit p9_client_exit(void)
2296 {
2297         kmem_cache_destroy(p9_req_cache);
2298 }
2299 

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