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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * This file contains functions assisting in mapping VFS to 9P20004 *5 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>7 */8 9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt10 11#include <linux/module.h>12#include <linux/errno.h>13#include <linux/fs.h>14#include <linux/sched.h>15#include <linux/cred.h>16#include <linux/parser.h>17#include <linux/slab.h>18#include <linux/seq_file.h>19#include <net/9p/9p.h>20#include <net/9p/client.h>21#include <net/9p/transport.h>22#include "v9fs.h"23#include "v9fs_vfs.h"24#include "cache.h"25 26static DEFINE_SPINLOCK(v9fs_sessionlist_lock);27static LIST_HEAD(v9fs_sessionlist);28struct kmem_cache *v9fs_inode_cache;29 30/*31 * Option Parsing (code inspired by NFS code)32 * NOTE: each transport will parse its own options33 */34 35enum {36 /* Options that take integer arguments */37 Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,38 /* String options */39 Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,40 /* Options that take no arguments */41 Opt_nodevmap, Opt_noxattr, Opt_directio, Opt_ignoreqv,42 /* Access options */43 Opt_access, Opt_posixacl,44 /* Lock timeout option */45 Opt_locktimeout,46 /* Error token */47 Opt_err48};49 50static const match_table_t tokens = {51 {Opt_debug, "debug=%x"},52 {Opt_dfltuid, "dfltuid=%u"},53 {Opt_dfltgid, "dfltgid=%u"},54 {Opt_afid, "afid=%u"},55 {Opt_uname, "uname=%s"},56 {Opt_remotename, "aname=%s"},57 {Opt_nodevmap, "nodevmap"},58 {Opt_noxattr, "noxattr"},59 {Opt_directio, "directio"},60 {Opt_ignoreqv, "ignoreqv"},61 {Opt_cache, "cache=%s"},62 {Opt_cachetag, "cachetag=%s"},63 {Opt_access, "access=%s"},64 {Opt_posixacl, "posixacl"},65 {Opt_locktimeout, "locktimeout=%u"},66 {Opt_err, NULL}67};68 69/* Interpret mount options for cache mode */70static int get_cache_mode(char *s)71{72 int version = -EINVAL;73 74 if (!strcmp(s, "loose")) {75 version = CACHE_SC_LOOSE;76 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");77 } else if (!strcmp(s, "fscache")) {78 version = CACHE_SC_FSCACHE;79 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");80 } else if (!strcmp(s, "mmap")) {81 version = CACHE_SC_MMAP;82 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");83 } else if (!strcmp(s, "readahead")) {84 version = CACHE_SC_READAHEAD;85 p9_debug(P9_DEBUG_9P, "Cache mode: readahead\n");86 } else if (!strcmp(s, "none")) {87 version = CACHE_SC_NONE;88 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");89 } else if (kstrtoint(s, 0, &version) != 0) {90 version = -EINVAL;91 pr_info("Unknown Cache mode or invalid value %s\n", s);92 }93 return version;94}95 96/*97 * Display the mount options in /proc/mounts.98 */99int v9fs_show_options(struct seq_file *m, struct dentry *root)100{101 struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;102 103 if (v9ses->debug)104 seq_printf(m, ",debug=%x", v9ses->debug);105 if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))106 seq_printf(m, ",dfltuid=%u",107 from_kuid_munged(&init_user_ns, v9ses->dfltuid));108 if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))109 seq_printf(m, ",dfltgid=%u",110 from_kgid_munged(&init_user_ns, v9ses->dfltgid));111 if (v9ses->afid != ~0)112 seq_printf(m, ",afid=%u", v9ses->afid);113 if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)114 seq_printf(m, ",uname=%s", v9ses->uname);115 if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)116 seq_printf(m, ",aname=%s", v9ses->aname);117 if (v9ses->nodev)118 seq_puts(m, ",nodevmap");119 if (v9ses->cache)120 seq_printf(m, ",cache=%x", v9ses->cache);121#ifdef CONFIG_9P_FSCACHE122 if (v9ses->cachetag && (v9ses->cache & CACHE_FSCACHE))123 seq_printf(m, ",cachetag=%s", v9ses->cachetag);124#endif125 126 switch (v9ses->flags & V9FS_ACCESS_MASK) {127 case V9FS_ACCESS_USER:128 seq_puts(m, ",access=user");129 break;130 case V9FS_ACCESS_ANY:131 seq_puts(m, ",access=any");132 break;133 case V9FS_ACCESS_CLIENT:134 seq_puts(m, ",access=client");135 break;136 case V9FS_ACCESS_SINGLE:137 seq_printf(m, ",access=%u",138 from_kuid_munged(&init_user_ns, v9ses->uid));139 break;140 }141 142 if (v9ses->flags & V9FS_IGNORE_QV)143 seq_puts(m, ",ignoreqv");144 if (v9ses->flags & V9FS_DIRECT_IO)145 seq_puts(m, ",directio");146 if (v9ses->flags & V9FS_POSIX_ACL)147 seq_puts(m, ",posixacl");148 149 if (v9ses->flags & V9FS_NO_XATTR)150 seq_puts(m, ",noxattr");151 152 return p9_show_client_options(m, v9ses->clnt);153}154 155/**156 * v9fs_parse_options - parse mount options into session structure157 * @v9ses: existing v9fs session information158 * @opts: The mount option string159 *160 * Return 0 upon success, -ERRNO upon failure.161 */162 163static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)164{165 char *options, *tmp_options;166 substring_t args[MAX_OPT_ARGS];167 char *p;168 int option = 0;169 char *s;170 int ret = 0;171 172 /* setup defaults */173 v9ses->afid = ~0;174 v9ses->debug = 0;175 v9ses->cache = CACHE_NONE;176#ifdef CONFIG_9P_FSCACHE177 v9ses->cachetag = NULL;178#endif179 v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;180 181 if (!opts)182 return 0;183 184 tmp_options = kstrdup(opts, GFP_KERNEL);185 if (!tmp_options) {186 ret = -ENOMEM;187 goto fail_option_alloc;188 }189 options = tmp_options;190 191 while ((p = strsep(&options, ",")) != NULL) {192 int token, r;193 194 if (!*p)195 continue;196 197 token = match_token(p, tokens, args);198 switch (token) {199 case Opt_debug:200 r = match_int(&args[0], &option);201 if (r < 0) {202 p9_debug(P9_DEBUG_ERROR,203 "integer field, but no integer?\n");204 ret = r;205 } else {206 v9ses->debug = option;207#ifdef CONFIG_NET_9P_DEBUG208 p9_debug_level = option;209#endif210 }211 break;212 213 case Opt_dfltuid:214 r = match_int(&args[0], &option);215 if (r < 0) {216 p9_debug(P9_DEBUG_ERROR,217 "integer field, but no integer?\n");218 ret = r;219 continue;220 }221 v9ses->dfltuid = make_kuid(current_user_ns(), option);222 if (!uid_valid(v9ses->dfltuid)) {223 p9_debug(P9_DEBUG_ERROR,224 "uid field, but not a uid?\n");225 ret = -EINVAL;226 }227 break;228 case Opt_dfltgid:229 r = match_int(&args[0], &option);230 if (r < 0) {231 p9_debug(P9_DEBUG_ERROR,232 "integer field, but no integer?\n");233 ret = r;234 continue;235 }236 v9ses->dfltgid = make_kgid(current_user_ns(), option);237 if (!gid_valid(v9ses->dfltgid)) {238 p9_debug(P9_DEBUG_ERROR,239 "gid field, but not a gid?\n");240 ret = -EINVAL;241 }242 break;243 case Opt_afid:244 r = match_int(&args[0], &option);245 if (r < 0) {246 p9_debug(P9_DEBUG_ERROR,247 "integer field, but no integer?\n");248 ret = r;249 } else {250 v9ses->afid = option;251 }252 break;253 case Opt_uname:254 kfree(v9ses->uname);255 v9ses->uname = match_strdup(&args[0]);256 if (!v9ses->uname) {257 ret = -ENOMEM;258 goto free_and_return;259 }260 break;261 case Opt_remotename:262 kfree(v9ses->aname);263 v9ses->aname = match_strdup(&args[0]);264 if (!v9ses->aname) {265 ret = -ENOMEM;266 goto free_and_return;267 }268 break;269 case Opt_nodevmap:270 v9ses->nodev = 1;271 break;272 case Opt_noxattr:273 v9ses->flags |= V9FS_NO_XATTR;274 break;275 case Opt_directio:276 v9ses->flags |= V9FS_DIRECT_IO;277 break;278 case Opt_ignoreqv:279 v9ses->flags |= V9FS_IGNORE_QV;280 break;281 case Opt_cachetag:282#ifdef CONFIG_9P_FSCACHE283 kfree(v9ses->cachetag);284 v9ses->cachetag = match_strdup(&args[0]);285 if (!v9ses->cachetag) {286 ret = -ENOMEM;287 goto free_and_return;288 }289#endif290 break;291 case Opt_cache:292 s = match_strdup(&args[0]);293 if (!s) {294 ret = -ENOMEM;295 p9_debug(P9_DEBUG_ERROR,296 "problem allocating copy of cache arg\n");297 goto free_and_return;298 }299 r = get_cache_mode(s);300 if (r < 0)301 ret = r;302 else303 v9ses->cache = r;304 305 kfree(s);306 break;307 308 case Opt_access:309 s = match_strdup(&args[0]);310 if (!s) {311 ret = -ENOMEM;312 p9_debug(P9_DEBUG_ERROR,313 "problem allocating copy of access arg\n");314 goto free_and_return;315 }316 317 v9ses->flags &= ~V9FS_ACCESS_MASK;318 if (strcmp(s, "user") == 0)319 v9ses->flags |= V9FS_ACCESS_USER;320 else if (strcmp(s, "any") == 0)321 v9ses->flags |= V9FS_ACCESS_ANY;322 else if (strcmp(s, "client") == 0) {323 v9ses->flags |= V9FS_ACCESS_CLIENT;324 } else {325 uid_t uid;326 327 v9ses->flags |= V9FS_ACCESS_SINGLE;328 r = kstrtouint(s, 10, &uid);329 if (r) {330 ret = r;331 pr_info("Unknown access argument %s: %d\n",332 s, r);333 kfree(s);334 continue;335 }336 v9ses->uid = make_kuid(current_user_ns(), uid);337 if (!uid_valid(v9ses->uid)) {338 ret = -EINVAL;339 pr_info("Unknown uid %s\n", s);340 }341 }342 343 kfree(s);344 break;345 346 case Opt_posixacl:347#ifdef CONFIG_9P_FS_POSIX_ACL348 v9ses->flags |= V9FS_POSIX_ACL;349#else350 p9_debug(P9_DEBUG_ERROR,351 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");352#endif353 break;354 355 case Opt_locktimeout:356 r = match_int(&args[0], &option);357 if (r < 0) {358 p9_debug(P9_DEBUG_ERROR,359 "integer field, but no integer?\n");360 ret = r;361 continue;362 }363 if (option < 1) {364 p9_debug(P9_DEBUG_ERROR,365 "locktimeout must be a greater than zero integer.\n");366 ret = -EINVAL;367 continue;368 }369 v9ses->session_lock_timeout = (long)option * HZ;370 break;371 372 default:373 continue;374 }375 }376 377free_and_return:378 kfree(tmp_options);379fail_option_alloc:380 return ret;381}382 383/**384 * v9fs_session_init - initialize session385 * @v9ses: session information structure386 * @dev_name: device being mounted387 * @data: options388 *389 */390 391struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,392 const char *dev_name, char *data)393{394 struct p9_fid *fid;395 int rc = -ENOMEM;396 397 v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);398 if (!v9ses->uname)399 goto err_names;400 401 v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);402 if (!v9ses->aname)403 goto err_names;404 init_rwsem(&v9ses->rename_sem);405 406 v9ses->uid = INVALID_UID;407 v9ses->dfltuid = V9FS_DEFUID;408 v9ses->dfltgid = V9FS_DEFGID;409 410 v9ses->clnt = p9_client_create(dev_name, data);411 if (IS_ERR(v9ses->clnt)) {412 rc = PTR_ERR(v9ses->clnt);413 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");414 goto err_names;415 }416 417 v9ses->flags = V9FS_ACCESS_USER;418 419 if (p9_is_proto_dotl(v9ses->clnt)) {420 v9ses->flags = V9FS_ACCESS_CLIENT;421 v9ses->flags |= V9FS_PROTO_2000L;422 } else if (p9_is_proto_dotu(v9ses->clnt)) {423 v9ses->flags |= V9FS_PROTO_2000U;424 }425 426 rc = v9fs_parse_options(v9ses, data);427 if (rc < 0)428 goto err_clnt;429 430 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;431 432 if (!v9fs_proto_dotl(v9ses) &&433 ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {434 /*435 * We support ACCESS_CLIENT only for dotl.436 * Fall back to ACCESS_USER437 */438 v9ses->flags &= ~V9FS_ACCESS_MASK;439 v9ses->flags |= V9FS_ACCESS_USER;440 }441 /*FIXME !! */442 /* for legacy mode, fall back to V9FS_ACCESS_ANY */443 if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&444 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {445 446 v9ses->flags &= ~V9FS_ACCESS_MASK;447 v9ses->flags |= V9FS_ACCESS_ANY;448 v9ses->uid = INVALID_UID;449 }450 if (!v9fs_proto_dotl(v9ses) ||451 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {452 /*453 * We support ACL checks on clinet only if the protocol is454 * 9P2000.L and access is V9FS_ACCESS_CLIENT.455 */456 v9ses->flags &= ~V9FS_ACL_MASK;457 }458 459 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,460 v9ses->aname);461 if (IS_ERR(fid)) {462 rc = PTR_ERR(fid);463 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");464 goto err_clnt;465 }466 467 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)468 fid->uid = v9ses->uid;469 else470 fid->uid = INVALID_UID;471 472#ifdef CONFIG_9P_FSCACHE473 /* register the session for caching */474 if (v9ses->cache & CACHE_FSCACHE) {475 rc = v9fs_cache_session_get_cookie(v9ses, dev_name);476 if (rc < 0)477 goto err_clnt;478 }479#endif480 spin_lock(&v9fs_sessionlist_lock);481 list_add(&v9ses->slist, &v9fs_sessionlist);482 spin_unlock(&v9fs_sessionlist_lock);483 484 return fid;485 486err_clnt:487#ifdef CONFIG_9P_FSCACHE488 kfree(v9ses->cachetag);489#endif490 p9_client_destroy(v9ses->clnt);491err_names:492 kfree(v9ses->uname);493 kfree(v9ses->aname);494 return ERR_PTR(rc);495}496 497/**498 * v9fs_session_close - shutdown a session499 * @v9ses: session information structure500 *501 */502 503void v9fs_session_close(struct v9fs_session_info *v9ses)504{505 if (v9ses->clnt) {506 p9_client_destroy(v9ses->clnt);507 v9ses->clnt = NULL;508 }509 510#ifdef CONFIG_9P_FSCACHE511 fscache_relinquish_volume(v9fs_session_cache(v9ses), NULL, false);512 kfree(v9ses->cachetag);513#endif514 kfree(v9ses->uname);515 kfree(v9ses->aname);516 517 spin_lock(&v9fs_sessionlist_lock);518 list_del(&v9ses->slist);519 spin_unlock(&v9fs_sessionlist_lock);520}521 522/**523 * v9fs_session_cancel - terminate a session524 * @v9ses: session to terminate525 *526 * mark transport as disconnected and cancel all pending requests.527 */528 529void v9fs_session_cancel(struct v9fs_session_info *v9ses)530{531 p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);532 p9_client_disconnect(v9ses->clnt);533}534 535/**536 * v9fs_session_begin_cancel - Begin terminate of a session537 * @v9ses: session to terminate538 *539 * After this call we don't allow any request other than clunk.540 */541 542void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)543{544 p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);545 p9_client_begin_disconnect(v9ses->clnt);546}547 548static struct kobject *v9fs_kobj;549 550#ifdef CONFIG_9P_FSCACHE551/*552 * List caches associated with a session553 */554static ssize_t caches_show(struct kobject *kobj,555 struct kobj_attribute *attr,556 char *buf)557{558 ssize_t n = 0, count = 0, limit = PAGE_SIZE;559 struct v9fs_session_info *v9ses;560 561 spin_lock(&v9fs_sessionlist_lock);562 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {563 if (v9ses->cachetag) {564 n = snprintf(buf, limit, "%s\n", v9ses->cachetag);565 if (n < 0) {566 count = n;567 break;568 }569 570 count += n;571 limit -= n;572 }573 }574 575 spin_unlock(&v9fs_sessionlist_lock);576 return count;577}578 579static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);580#endif /* CONFIG_9P_FSCACHE */581 582static struct attribute *v9fs_attrs[] = {583#ifdef CONFIG_9P_FSCACHE584 &v9fs_attr_cache.attr,585#endif586 NULL,587};588 589static const struct attribute_group v9fs_attr_group = {590 .attrs = v9fs_attrs,591};592 593/**594 * v9fs_sysfs_init - Initialize the v9fs sysfs interface595 *596 */597 598static int __init v9fs_sysfs_init(void)599{600 v9fs_kobj = kobject_create_and_add("9p", fs_kobj);601 if (!v9fs_kobj)602 return -ENOMEM;603 604 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {605 kobject_put(v9fs_kobj);606 return -ENOMEM;607 }608 609 return 0;610}611 612/**613 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface614 *615 */616 617static void v9fs_sysfs_cleanup(void)618{619 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);620 kobject_put(v9fs_kobj);621}622 623static void v9fs_inode_init_once(void *foo)624{625 struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;626 627 memset(&v9inode->qid, 0, sizeof(v9inode->qid));628 inode_init_once(&v9inode->netfs.inode);629}630 631/**632 * v9fs_init_inode_cache - initialize a cache for 9P633 * 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|640 SLAB_ACCOUNT),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 inode650 *651 */652static void v9fs_destroy_inode_cache(void)653{654 /*655 * Make sure all delayed rcu free inodes are flushed before we656 * destroy cache.657 */658 rcu_barrier();659 kmem_cache_destroy(v9fs_inode_cache);660}661 662static int v9fs_cache_register(void)663{664 int ret;665 666 ret = v9fs_init_inode_cache();667 if (ret < 0)668 return ret;669 return ret;670}671 672static void v9fs_cache_unregister(void)673{674 v9fs_destroy_inode_cache();675}676 677/**678 * init_v9fs - Initialize module679 *680 */681 682static int __init init_v9fs(void)683{684 int err;685 686 pr_info("Installing v9fs 9p2000 file system support\n");687 /* TODO: Setup list of registered trasnport modules */688 689 err = v9fs_cache_register();690 if (err < 0) {691 pr_err("Failed to register v9fs for caching\n");692 return err;693 }694 695 err = v9fs_sysfs_init();696 if (err < 0) {697 pr_err("Failed to register with sysfs\n");698 goto out_cache;699 }700 err = register_filesystem(&v9fs_fs_type);701 if (err < 0) {702 pr_err("Failed to register filesystem\n");703 goto out_sysfs_cleanup;704 }705 706 return 0;707 708out_sysfs_cleanup:709 v9fs_sysfs_cleanup();710 711out_cache:712 v9fs_cache_unregister();713 714 return err;715}716 717/**718 * exit_v9fs - shutdown module719 *720 */721 722static void __exit exit_v9fs(void)723{724 v9fs_sysfs_cleanup();725 v9fs_cache_unregister();726 unregister_filesystem(&v9fs_fs_type);727}728 729module_init(init_v9fs)730module_exit(exit_v9fs)731 732MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");733MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");734MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");735MODULE_DESCRIPTION("9P Client File System");736MODULE_LICENSE("GPL");737