projects / linux-2.6-block.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Merge drm-misc-next-fixes-2019-10-02 into drm-misc-fixes
[linux-2.6-block.git] / fs / 9p / v9fs.c
CommitLineData
1f327613 1// SPDX-License-Identifier: GPL-2.0-only
9e82cf6a
EVH		 2/*
3 * linux/fs/9p/v9fs.c
4 *
5 * This file contains functions assisting in mapping VFS to 9P2000
6 *
8a0dc95f 7 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
9e82cf6a 8 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9e82cf6a
EVH		 9 */
10
5d385153
JP		 11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
9e82cf6a
EVH		 13#include <linux/module.h>
14#include <linux/errno.h>
15#include <linux/fs.h>
914e2637 16#include <linux/sched.h>
5b825c3a 17#include <linux/cred.h>
9e82cf6a
EVH		 18#include <linux/parser.h>
19#include <linux/idr.h>
5a0e3ad6 20#include <linux/slab.h>
c4fac910 21#include <linux/seq_file.h>
bd238fb4 22#include <net/9p/9p.h>
bd238fb4 23#include <net/9p/client.h>
8b81ef58 24#include <net/9p/transport.h>
9e82cf6a 25#include "v9fs.h"
9e82cf6a 26#include "v9fs_vfs.h"
60e78d2c
AK		 27#include "cache.h"
28
29static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
30static LIST_HEAD(v9fs_sessionlist);
a78ce05d 31struct kmem_cache *v9fs_inode_cache;
9e82cf6a
EVH		 32
33/*
60e78d2c
AK		 34 * Option Parsing (code inspired by NFS code)
35 * NOTE: each transport will parse its own options
36 */
9e82cf6a
EVH		 37
38enum {
39 /* Options that take integer arguments */
8a0dc95f 40 Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
9e82cf6a 41 /* String options */
cb9af418 42 Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
9e82cf6a 43 /* Options that take no arguments */
8a0dc95f 44 Opt_nodevmap,
e03abc0c 45 /* Cache options */
fb89b45c 46 Opt_cache_loose, Opt_fscache, Opt_mmap,
ba17674f 47 /* Access options */
e782ef71 48 Opt_access, Opt_posixacl,
5e172f75
DRCS		 49 /* Lock timeout option */
50 Opt_locktimeout,
9e82cf6a
EVH		 51 /* Error token */
52 Opt_err
53};
54
a447c093 55static const match_table_t tokens = {
9e2f6688 56 {Opt_debug, "debug=%x"},
bd32b82d
LI		 57 {Opt_dfltuid, "dfltuid=%u"},
58 {Opt_dfltgid, "dfltgid=%u"},
9e82cf6a 59 {Opt_afid, "afid=%u"},
67543e50 60 {Opt_uname, "uname=%s"},
9e82cf6a 61 {Opt_remotename, "aname=%s"},
9e82cf6a 62 {Opt_nodevmap, "nodevmap"},
60e78d2c 63 {Opt_cache, "cache=%s"},
e03abc0c 64 {Opt_cache_loose, "loose"},
60e78d2c 65 {Opt_fscache, "fscache"},
fb89b45c 66 {Opt_mmap, "mmap"},
60e78d2c 67 {Opt_cachetag, "cachetag=%s"},
ba17674f 68 {Opt_access, "access=%s"},
e782ef71 69 {Opt_posixacl, "posixacl"},
5e172f75 70 {Opt_locktimeout, "locktimeout=%u"},
9e82cf6a
EVH		 71 {Opt_err, NULL}
72};
73
c4fac910
DH		 74static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
75 [CACHE_NONE] = "none",
76 [CACHE_MMAP] = "mmap",
77 [CACHE_LOOSE] = "loose",
78 [CACHE_FSCACHE] = "fscache",
79};
80
a2dd43bb
PK		 81/* Interpret mount options for cache mode */
82static int get_cache_mode(char *s)
83{
84 int version = -EINVAL;
85
86 if (!strcmp(s, "loose")) {
87 version = CACHE_LOOSE;
5d385153 88 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
a2dd43bb
PK		 89 } else if (!strcmp(s, "fscache")) {
90 version = CACHE_FSCACHE;
5d385153 91 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
fb89b45c
DM		 92 } else if (!strcmp(s, "mmap")) {
93 version = CACHE_MMAP;
94 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
a2dd43bb
PK		 95 } else if (!strcmp(s, "none")) {
96 version = CACHE_NONE;
5d385153 97 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
a2dd43bb 98 } else
5d385153 99 pr_info("Unknown Cache mode %s\n", s);
a2dd43bb
PK		 100 return version;
101}
102
c4fac910
DH		 103/*
104 * Display the mount options in /proc/mounts.
105 */
106int v9fs_show_options(struct seq_file *m, struct dentry *root)
107{
108 struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
109
110 if (v9ses->debug)
111 seq_printf(m, ",debug=%x", v9ses->debug);
112 if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
113 seq_printf(m, ",dfltuid=%u",
114 from_kuid_munged(&init_user_ns, v9ses->dfltuid));
115 if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
116 seq_printf(m, ",dfltgid=%u",
117 from_kgid_munged(&init_user_ns, v9ses->dfltgid));
118 if (v9ses->afid != ~0)
119 seq_printf(m, ",afid=%u", v9ses->afid);
120 if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
121 seq_printf(m, ",uname=%s", v9ses->uname);
122 if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
123 seq_printf(m, ",aname=%s", v9ses->aname);
124 if (v9ses->nodev)
125 seq_puts(m, ",nodevmap");
126 if (v9ses->cache)
127 seq_printf(m, ",%s", v9fs_cache_modes[v9ses->cache]);
128#ifdef CONFIG_9P_FSCACHE
129 if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
130 seq_printf(m, ",cachetag=%s", v9ses->cachetag);
131#endif
132
133 switch (v9ses->flags & V9FS_ACCESS_MASK) {
134 case V9FS_ACCESS_USER:
135 seq_puts(m, ",access=user");
136 break;
137 case V9FS_ACCESS_ANY:
138 seq_puts(m, ",access=any");
139 break;
140 case V9FS_ACCESS_CLIENT:
141 seq_puts(m, ",access=client");
142 break;
143 case V9FS_ACCESS_SINGLE:
144 seq_printf(m, ",access=%u",
145 from_kuid_munged(&init_user_ns, v9ses->uid));
146 break;
147 }
148
149 if (v9ses->flags & V9FS_POSIX_ACL)
150 seq_puts(m, ",posixacl");
151
152 return p9_show_client_options(m, v9ses->clnt);
153}
154
9e82cf6a
EVH		 155/**
156 * v9fs_parse_options - parse mount options into session structure
9e82cf6a
EVH		 157 * @v9ses: existing v9fs session information
158 *
ab31267d 159 * Return 0 upon success, -ERRNO upon failure.
9e82cf6a
EVH		 160 */
161
4b53e4b5 162static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
9e82cf6a 163{
d8c8a9e3 164 char *options, *tmp_options;
9e82cf6a 165 substring_t args[MAX_OPT_ARGS];
a80d923e 166 char *p;
8a0dc95f 167 int option = 0;
ba17674f 168 char *s, *e;
ab31267d 169 int ret = 0;
9e82cf6a
EVH		 170
171 /* setup defaults */
9e82cf6a
EVH		 172 v9ses->afid = ~0;
173 v9ses->debug = 0;
a2dd43bb 174 v9ses->cache = CACHE_NONE;
60e78d2c
AK		 175#ifdef CONFIG_9P_FSCACHE
176 v9ses->cachetag = NULL;
177#endif
5e172f75 178 v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
9e82cf6a 179
4b53e4b5 180 if (!opts)
ab31267d 181 return 0;
9e82cf6a 182
d8c8a9e3 183 tmp_options = kstrdup(opts, GFP_KERNEL);
bf2d29c6
EVH		 184 if (!tmp_options) {
185 ret = -ENOMEM;
60e78d2c 186 goto fail_option_alloc;
bf2d29c6 187 }
d8c8a9e3 188 options = tmp_options;
ab31267d 189
9e82cf6a 190 while ((p = strsep(&options, ",")) != NULL) {
4d5077f1 191 int token, r;
9e82cf6a
EVH		 192 if (!*p)
193 continue;
194 token = match_token(p, tokens, args);
4d5077f1
AK		 195 switch (token) {
196 case Opt_debug:
197 r = match_int(&args[0], &option);
ab31267d 198 if (r < 0) {
5d385153
JP		 199 p9_debug(P9_DEBUG_ERROR,
200 "integer field, but no integer?\n");
ab31267d 201 ret = r;
478ae0ca
CX		 202 } else {
203 v9ses->debug = option;
10fa16e7 204#ifdef CONFIG_NET_9P_DEBUG
478ae0ca 205 p9_debug_level = option;
10fa16e7 206#endif
478ae0ca 207 }
9e2f6688 208 break;
8a0dc95f 209
bd32b82d 210 case Opt_dfltuid:
4d5077f1
AK		 211 r = match_int(&args[0], &option);
212 if (r < 0) {
5d385153
JP		 213 p9_debug(P9_DEBUG_ERROR,
214 "integer field, but no integer?\n");
4d5077f1
AK		 215 ret = r;
216 continue;
217 }
76ed23a5
EB		 218 v9ses->dfltuid = make_kuid(current_user_ns(), option);
219 if (!uid_valid(v9ses->dfltuid)) {
220 p9_debug(P9_DEBUG_ERROR,
221 "uid field, but not a uid?\n");
222 ret = -EINVAL;
76ed23a5 223 }
9e82cf6a 224 break;
bd32b82d 225 case Opt_dfltgid:
4d5077f1
AK		 226 r = match_int(&args[0], &option);
227 if (r < 0) {
5d385153
JP		 228 p9_debug(P9_DEBUG_ERROR,
229 "integer field, but no integer?\n");
4d5077f1
AK		 230 ret = r;
231 continue;
232 }
76ed23a5
EB		 233 v9ses->dfltgid = make_kgid(current_user_ns(), option);
234 if (!gid_valid(v9ses->dfltgid)) {
235 p9_debug(P9_DEBUG_ERROR,
236 "gid field, but not a gid?\n");
237 ret = -EINVAL;
76ed23a5 238 }
9e82cf6a
EVH		 239 break;
240 case Opt_afid:
4d5077f1
AK		 241 r = match_int(&args[0], &option);
242 if (r < 0) {
5d385153
JP		 243 p9_debug(P9_DEBUG_ERROR,
244 "integer field, but no integer?\n");
4d5077f1 245 ret = r;
478ae0ca
CX		 246 } else {
247 v9ses->afid = option;
4d5077f1 248 }
9e82cf6a 249 break;
67543e50 250 case Opt_uname:
e549c133
JL		 251 kfree(v9ses->uname);
252 v9ses->uname = match_strdup(&args[0]);
253 if (!v9ses->uname) {
254 ret = -ENOMEM;
255 goto free_and_return;
256 }
9e82cf6a
EVH		 257 break;
258 case Opt_remotename:
e549c133
JL		 259 kfree(v9ses->aname);
260 v9ses->aname = match_strdup(&args[0]);
261 if (!v9ses->aname) {
262 ret = -ENOMEM;
263 goto free_and_return;
264 }
9e82cf6a 265 break;
9e82cf6a
EVH		 266 case Opt_nodevmap:
267 v9ses->nodev = 1;
268 break;
e03abc0c
EVH		 269 case Opt_cache_loose:
270 v9ses->cache = CACHE_LOOSE;
271 break;
60e78d2c
AK		 272 case Opt_fscache:
273 v9ses->cache = CACHE_FSCACHE;
274 break;
fb89b45c
DM		 275 case Opt_mmap:
276 v9ses->cache = CACHE_MMAP;
277 break;
60e78d2c
AK		 278 case Opt_cachetag:
279#ifdef CONFIG_9P_FSCACHE
c4fac910 280 kfree(v9ses->cachetag);
60e78d2c 281 v9ses->cachetag = match_strdup(&args[0]);
a25c3657
CX		 282 if (!v9ses->cachetag) {
283 ret = -ENOMEM;
284 goto free_and_return;
285 }
60e78d2c
AK		 286#endif
287 break;
288 case Opt_cache:
289 s = match_strdup(&args[0]);
bf2d29c6
EVH		 290 if (!s) {
291 ret = -ENOMEM;
5d385153
JP		 292 p9_debug(P9_DEBUG_ERROR,
293 "problem allocating copy of cache arg\n");
bf2d29c6
EVH		 294 goto free_and_return;
295 }
478ae0ca
CX		 296 r = get_cache_mode(s);
297 if (r < 0)
298 ret = r;
299 else
300 v9ses->cache = r;
60e78d2c 301
60e78d2c
AK		 302 kfree(s);
303 break;
ba17674f
LI		 304
305 case Opt_access:
306 s = match_strdup(&args[0]);
bf2d29c6
EVH		 307 if (!s) {
308 ret = -ENOMEM;
5d385153
JP		 309 p9_debug(P9_DEBUG_ERROR,
310 "problem allocating copy of access arg\n");
bf2d29c6
EVH		 311 goto free_and_return;
312 }
60e78d2c 313
ba17674f
LI		 314 v9ses->flags &= ~V9FS_ACCESS_MASK;
315 if (strcmp(s, "user") == 0)
316 v9ses->flags |= V9FS_ACCESS_USER;
317 else if (strcmp(s, "any") == 0)
318 v9ses->flags |= V9FS_ACCESS_ANY;
76381a42 319 else if (strcmp(s, "client") == 0) {
76381a42 320 v9ses->flags |= V9FS_ACCESS_CLIENT;
76381a42 321 } else {
76ed23a5 322 uid_t uid;
ba17674f 323 v9ses->flags |= V9FS_ACCESS_SINGLE;
76ed23a5 324 uid = simple_strtoul(s, &e, 10);
a2dd43bb
PK		 325 if (*e != '\0') {
326 ret = -EINVAL;
5d385153
JP		 327 pr_info("Unknown access argument %s\n",
328 s);
a2dd43bb 329 kfree(s);
478ae0ca 330 continue;
a2dd43bb 331 }
76ed23a5
EB		 332 v9ses->uid = make_kuid(current_user_ns(), uid);
333 if (!uid_valid(v9ses->uid)) {
334 ret = -EINVAL;
6baaac09 335 pr_info("Unknown uid %s\n", s);
76ed23a5 336 }
ba17674f 337 }
a2dd43bb 338
0a976297 339 kfree(s);
ba17674f
LI		 340 break;
341
e782ef71
VJJ		 342 case Opt_posixacl:
343#ifdef CONFIG_9P_FS_POSIX_ACL
344 v9ses->flags |= V9FS_POSIX_ACL;
345#else
5d385153
JP		 346 p9_debug(P9_DEBUG_ERROR,
347 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
e782ef71
VJJ		 348#endif
349 break;
350
5e172f75
DRCS		 351 case Opt_locktimeout:
352 r = match_int(&args[0], &option);
353 if (r < 0) {
354 p9_debug(P9_DEBUG_ERROR,
355 "integer field, but no integer?\n");
356 ret = r;
357 continue;
358 }
359 if (option < 1) {
360 p9_debug(P9_DEBUG_ERROR,
361 "locktimeout must be a greater than zero integer.\n");
362 ret = -EINVAL;
363 continue;
364 }
365 v9ses->session_lock_timeout = (long)option * HZ;
366 break;
367
9e82cf6a
EVH		 368 default:
369 continue;
370 }
371 }
d8c8a9e3 372
bf2d29c6 373free_and_return:
d8c8a9e3 374 kfree(tmp_options);
60e78d2c 375fail_option_alloc:
bf2d29c6 376 return ret;
9e82cf6a
EVH		 377}
378
9e82cf6a
EVH		 379/**
380 * v9fs_session_init - initialize session
381 * @v9ses: session information structure
382 * @dev_name: device being mounted
383 * @data: options
384 *
385 */
386
bd238fb4 387struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
9e82cf6a
EVH		 388 const char *dev_name, char *data)
389{
bd238fb4 390 struct p9_fid *fid;
412a19b6 391 int rc = -ENOMEM;
9e82cf6a 392
e549c133 393 v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
ba17674f 394 if (!v9ses->uname)
412a19b6 395 goto err_names;
9e82cf6a 396
e549c133 397 v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
412a19b6
TH		 398 if (!v9ses->aname)
399 goto err_names;
a534c8d1 400 init_rwsem(&v9ses->rename_sem);
9e82cf6a 401
76ed23a5 402 v9ses->uid = INVALID_UID;
bd32b82d
LI		 403 v9ses->dfltuid = V9FS_DEFUID;
404 v9ses->dfltgid = V9FS_DEFGID;
ab31267d 405
4b53e4b5 406 v9ses->clnt = p9_client_create(dev_name, data);
bd238fb4 407 if (IS_ERR(v9ses->clnt)) {
412a19b6 408 rc = PTR_ERR(v9ses->clnt);
5d385153 409 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
71304feb 410 goto err_names;
9e82cf6a
EVH		 411 }
412
6752a1eb
VJJ		 413 v9ses->flags = V9FS_ACCESS_USER;
414
415 if (p9_is_proto_dotl(v9ses->clnt)) {
416 v9ses->flags = V9FS_ACCESS_CLIENT;
476ada04 417 v9ses->flags |= V9FS_PROTO_2000L;
6752a1eb 418 } else if (p9_is_proto_dotu(v9ses->clnt)) {
476ada04 419 v9ses->flags |= V9FS_PROTO_2000U;
6752a1eb
VJJ		 420 }
421
422 rc = v9fs_parse_options(v9ses, data);
412a19b6
TH		 423 if (rc < 0)
424 goto err_clnt;
ba17674f 425
fbedadc1 426 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
8a0dc95f 427
76381a42
AK		 428 if (!v9fs_proto_dotl(v9ses) &&
429 ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
430 /*
431 * We support ACCESS_CLIENT only for dotl.
432 * Fall back to ACCESS_USER
433 */
434 v9ses->flags &= ~V9FS_ACCESS_MASK;
435 v9ses->flags |= V9FS_ACCESS_USER;
436 }
437 /*FIXME !! */
ba17674f 438 /* for legacy mode, fall back to V9FS_ACCESS_ANY */
9ffaf63e 439 if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
ba17674f
LI		 440 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
441
442 v9ses->flags &= ~V9FS_ACCESS_MASK;
443 v9ses->flags |= V9FS_ACCESS_ANY;
76ed23a5 444 v9ses->uid = INVALID_UID;
ba17674f 445 }
e782ef71
VJJ		 446 if (!v9fs_proto_dotl(v9ses) ||
447 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
448 /*
449 * We support ACL checks on clinet only if the protocol is
450 * 9P2000.L and access is V9FS_ACCESS_CLIENT.
451 */
452 v9ses->flags &= ~V9FS_ACL_MASK;
453 }
ba17674f 454
f791f7c5 455 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
ba17674f 456 v9ses->aname);
bd238fb4 457 if (IS_ERR(fid)) {
412a19b6 458 rc = PTR_ERR(fid);
5d385153 459 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
412a19b6 460 goto err_clnt;
9e82cf6a
EVH		 461 }
462
ba17674f
LI		 463 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
464 fid->uid = v9ses->uid;
465 else
b4642556 466 fid->uid = INVALID_UID;
ba17674f 467
60e78d2c
AK		 468#ifdef CONFIG_9P_FSCACHE
469 /* register the session for caching */
470 v9fs_cache_session_get_cookie(v9ses);
471#endif
412a19b6
TH		 472 spin_lock(&v9fs_sessionlist_lock);
473 list_add(&v9ses->slist, &v9fs_sessionlist);
474 spin_unlock(&v9fs_sessionlist_lock);
60e78d2c 475
bd238fb4 476 return fid;
9e82cf6a 477
412a19b6 478err_clnt:
a25c3657
CX		 479#ifdef CONFIG_9P_FSCACHE
480 kfree(v9ses->cachetag);
481#endif
412a19b6 482 p9_client_destroy(v9ses->clnt);
412a19b6
TH		 483err_names:
484 kfree(v9ses->uname);
485 kfree(v9ses->aname);
486 return ERR_PTR(rc);
9e82cf6a
EVH		 487}
488
489/**
490 * v9fs_session_close - shutdown a session
491 * @v9ses: session information structure
492 *
493 */
494
495void v9fs_session_close(struct v9fs_session_info *v9ses)
496{
bd238fb4
LI		 497 if (v9ses->clnt) {
498 p9_client_destroy(v9ses->clnt);
499 v9ses->clnt = NULL;
3cf6429a 500 }
9e82cf6a 501
60e78d2c
AK		 502#ifdef CONFIG_9P_FSCACHE
503 if (v9ses->fscache) {
504 v9fs_cache_session_put_cookie(v9ses);
505 kfree(v9ses->cachetag);
506 }
507#endif
e549c133
JL		 508 kfree(v9ses->uname);
509 kfree(v9ses->aname);
60e78d2c
AK		 510
511 spin_lock(&v9fs_sessionlist_lock);
512 list_del(&v9ses->slist);
513 spin_unlock(&v9fs_sessionlist_lock);
9e82cf6a
EVH		 514}
515
322b329a 516/**
ee443996
EVH		 517 * v9fs_session_cancel - terminate a session
518 * @v9ses: session to terminate
519 *
520 * mark transport as disconnected and cancel all pending requests.
322b329a 521 */
ee443996 522
322b329a 523void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
5d385153 524 p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
bd238fb4 525 p9_client_disconnect(v9ses->clnt);
322b329a
EVH		 526}
527
6d96d3ab
AK		 528/**
529 * v9fs_session_begin_cancel - Begin terminate of a session
530 * @v9ses: session to terminate
531 *
532 * After this call we don't allow any request other than clunk.
533 */
534
535void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
536{
5d385153 537 p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
6d96d3ab
AK		 538 p9_client_begin_disconnect(v9ses->clnt);
539}
540
9e82cf6a
EVH		 541extern int v9fs_error_init(void);
542
60e78d2c
AK		 543static struct kobject *v9fs_kobj;
544
545#ifdef CONFIG_9P_FSCACHE
9e82cf6a 546/**
60e78d2c
AK		 547 * caches_show - list caches associated with a session
548 *
549 * Returns the size of buffer written.
550 */
551
552static ssize_t caches_show(struct kobject *kobj,
553 struct kobj_attribute *attr,
554 char *buf)
555{
556 ssize_t n = 0, count = 0, limit = PAGE_SIZE;
557 struct v9fs_session_info *v9ses;
558
559 spin_lock(&v9fs_sessionlist_lock);
560 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
561 if (v9ses->cachetag) {
562 n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
563 if (n < 0) {
564 count = n;
565 break;
566 }
567
568 count += n;
569 limit -= n;
570 }
571 }
572
573 spin_unlock(&v9fs_sessionlist_lock);
574 return count;
575}
576
577static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
578#endif /* CONFIG_9P_FSCACHE */
579
580static struct attribute *v9fs_attrs[] = {
581#ifdef CONFIG_9P_FSCACHE
582 &v9fs_attr_cache.attr,
583#endif
584 NULL,
585};
586
587static struct attribute_group v9fs_attr_group = {
588 .attrs = v9fs_attrs,
589};
590
591/**
592 * v9fs_sysfs_init - Initialize the v9fs sysfs interface
593 *
594 */
595
bdbeacde 596static int __init v9fs_sysfs_init(void)
60e78d2c
AK		 597{
598 v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
599 if (!v9fs_kobj)
600 return -ENOMEM;
601
602 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
603 kobject_put(v9fs_kobj);
604 return -ENOMEM;
605 }
606
607 return 0;
608}
609
610/**
611 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
612 *
613 */
614
615static void v9fs_sysfs_cleanup(void)
616{
617 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
618 kobject_put(v9fs_kobj);
619}
620
a78ce05d
AK		 621static void v9fs_inode_init_once(void *foo)
622{
623 struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
624#ifdef CONFIG_9P_FSCACHE
625 v9inode->fscache = NULL;
a78ce05d 626#endif
fd2421f5 627 memset(&v9inode->qid, 0, sizeof(v9inode->qid));
a78ce05d
AK		 628 inode_init_once(&v9inode->vfs_inode);
629}
630
631/**
632 * v9fs_init_inode_cache - initialize a cache for 9P
633 * Returns 0 on success.
634 */
635static int v9fs_init_inode_cache(void)
636{
637 v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
638 sizeof(struct v9fs_inode),
639 0, (SLAB_RECLAIM_ACCOUNT|
5d097056 640 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
a78ce05d
AK		 641 v9fs_inode_init_once);
642 if (!v9fs_inode_cache)
643 return -ENOMEM;
644
645 return 0;
646}
647
648/**
649 * v9fs_destroy_inode_cache - destroy the cache of 9P inode
650 *
651 */
652static void v9fs_destroy_inode_cache(void)
653{
8c0a8537
KS		 654 /*
655 * Make sure all delayed rcu free inodes are flushed before we
656 * destroy cache.
657 */
658 rcu_barrier();
a78ce05d
AK		 659 kmem_cache_destroy(v9fs_inode_cache);
660}
661
662static int v9fs_cache_register(void)
663{
664 int ret;
665 ret = v9fs_init_inode_cache();
666 if (ret < 0)
667 return ret;
668#ifdef CONFIG_9P_FSCACHE
8061a6fa
AV		 669 ret = fscache_register_netfs(&v9fs_cache_netfs);
670 if (ret < 0)
671 v9fs_destroy_inode_cache();
a78ce05d 672#endif
8061a6fa 673 return ret;
a78ce05d
AK		 674}
675
676static void v9fs_cache_unregister(void)
677{
678 v9fs_destroy_inode_cache();
679#ifdef CONFIG_9P_FSCACHE
680 fscache_unregister_netfs(&v9fs_cache_netfs);
681#endif
682}
683
60e78d2c
AK		 684/**
685 * init_v9fs - Initialize module
9e82cf6a
EVH		 686 *
687 */
688
689static int __init init_v9fs(void)
690{
60e78d2c 691 int err;
5d385153 692 pr_info("Installing v9fs 9p2000 file system support\n");
a80d923e 693 /* TODO: Setup list of registered trasnport modules */
60e78d2c
AK		 694
695 err = v9fs_cache_register();
696 if (err < 0) {
5d385153 697 pr_err("Failed to register v9fs for caching\n");
2226a288 698 return err;
60e78d2c
AK		 699 }
700
701 err = v9fs_sysfs_init();
702 if (err < 0) {
5d385153 703 pr_err("Failed to register with sysfs\n");
2226a288
AV		 704 goto out_cache;
705 }
706 err = register_filesystem(&v9fs_fs_type);
707 if (err < 0) {
708 pr_err("Failed to register filesystem\n");
60e78d2c
AK		 709 goto out_sysfs_cleanup;
710 }
711
712 return 0;
713
714out_sysfs_cleanup:
715 v9fs_sysfs_cleanup();
716
2226a288
AV		 717out_cache:
718 v9fs_cache_unregister();
60e78d2c
AK		 719
720 return err;
9e82cf6a
EVH		 721}
722
723/**
60e78d2c 724 * exit_v9fs - shutdown module
9e82cf6a
EVH		 725 *
726 */
727
728static void __exit exit_v9fs(void)
729{
60e78d2c
AK		 730 v9fs_sysfs_cleanup();
731 v9fs_cache_unregister();
9e82cf6a
EVH		 732 unregister_filesystem(&v9fs_fs_type);
733}
734
735module_init(init_v9fs)
736module_exit(exit_v9fs)
737
bd238fb4 738MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
9e82cf6a
EVH		 739MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
740MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
741MODULE_LICENSE("GPL");
Linux 6.x block layer and io_uring tree(s)