// SPDX-License-Identifier: GPL-2.0-only /* * This file contains functions assisting in mapping VFS to 9P2000 * * Copyright (C) 2004-2008 by Eric Van Hensbergen * Copyright (C) 2002 by Ron Minnich */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include "v9fs.h" #include "v9fs_vfs.h" #include "cache.h" static DEFINE_SPINLOCK(v9fs_sessionlist_lock); static LIST_HEAD(v9fs_sessionlist); struct kmem_cache *v9fs_inode_cache; /* * Option Parsing (code inspired by NFS code) * NOTE: each transport will parse its own options */ enum { /* Options that take integer arguments */ Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid, /* String options */ Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag, /* Options that take no arguments */ Opt_nodevmap, Opt_noxattr, Opt_directio, Opt_ignoreqv, /* Access options */ Opt_access, Opt_posixacl, /* Lock timeout option */ Opt_locktimeout, /* Error token */ Opt_err }; static const match_table_t tokens = { {Opt_debug, "debug=%x"}, {Opt_dfltuid, "dfltuid=%u"}, {Opt_dfltgid, "dfltgid=%u"}, {Opt_afid, "afid=%u"}, {Opt_uname, "uname=%s"}, {Opt_remotename, "aname=%s"}, {Opt_nodevmap, "nodevmap"}, {Opt_noxattr, "noxattr"}, {Opt_directio, "directio"}, {Opt_ignoreqv, "ignoreqv"}, {Opt_cache, "cache=%s"}, {Opt_cachetag, "cachetag=%s"}, {Opt_access, "access=%s"}, {Opt_posixacl, "posixacl"}, {Opt_locktimeout, "locktimeout=%u"}, {Opt_err, NULL} }; /* Interpret mount options for cache mode */ static int get_cache_mode(char *s) { int version = -EINVAL; if (!strcmp(s, "loose")) { version = CACHE_SC_LOOSE; p9_debug(P9_DEBUG_9P, "Cache mode: loose\n"); } else if (!strcmp(s, "fscache")) { version = CACHE_SC_FSCACHE; p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n"); } else if (!strcmp(s, "mmap")) { version = CACHE_SC_MMAP; p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n"); } else if (!strcmp(s, "readahead")) { version = CACHE_SC_READAHEAD; p9_debug(P9_DEBUG_9P, "Cache mode: readahead\n"); } else if (!strcmp(s, "none")) { version = CACHE_SC_NONE; p9_debug(P9_DEBUG_9P, "Cache mode: none\n"); } else if (kstrtoint(s, 0, &version) != 0) { version = -EINVAL; pr_info("Unknown Cache mode or invalid value %s\n", s); } return version; } /* * Display the mount options in /proc/mounts. */ int v9fs_show_options(struct seq_file *m, struct dentry *root) { struct v9fs_session_info *v9ses = root->d_sb->s_fs_info; if (v9ses->debug) seq_printf(m, ",debug=%x", v9ses->debug); if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID)) seq_printf(m, ",dfltuid=%u", from_kuid_munged(&init_user_ns, v9ses->dfltuid)); if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID)) seq_printf(m, ",dfltgid=%u", from_kgid_munged(&init_user_ns, v9ses->dfltgid)); if (v9ses->afid != ~0) seq_printf(m, ",afid=%u", v9ses->afid); if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0) seq_printf(m, ",uname=%s", v9ses->uname); if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0) seq_printf(m, ",aname=%s", v9ses->aname); if (v9ses->nodev) seq_puts(m, ",nodevmap"); if (v9ses->cache) seq_printf(m, ",cache=%x", v9ses->cache); #ifdef CONFIG_9P_FSCACHE if (v9ses->cachetag && (v9ses->cache & CACHE_FSCACHE)) seq_printf(m, ",cachetag=%s", v9ses->cachetag); #endif switch (v9ses->flags & V9FS_ACCESS_MASK) { case V9FS_ACCESS_USER: seq_puts(m, ",access=user"); break; case V9FS_ACCESS_ANY: seq_puts(m, ",access=any"); break; case V9FS_ACCESS_CLIENT: seq_puts(m, ",access=client"); break; case V9FS_ACCESS_SINGLE: seq_printf(m, ",access=%u", from_kuid_munged(&init_user_ns, v9ses->uid)); break; } if (v9ses->flags & V9FS_IGNORE_QV) seq_puts(m, ",ignoreqv"); if (v9ses->flags & V9FS_DIRECT_IO) seq_puts(m, ",directio"); if (v9ses->flags & V9FS_POSIX_ACL) seq_puts(m, ",posixacl"); if (v9ses->flags & V9FS_NO_XATTR) seq_puts(m, ",noxattr"); return p9_show_client_options(m, v9ses->clnt); } /** * v9fs_parse_options - parse mount options into session structure * @v9ses: existing v9fs session information * @opts: The mount option string * * Return 0 upon success, -ERRNO upon failure. */ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts) { char *options, *tmp_options; substring_t args[MAX_OPT_ARGS]; char *p; int option = 0; char *s; int ret = 0; /* setup defaults */ v9ses->afid = ~0; v9ses->debug = 0; v9ses->cache = CACHE_NONE; #ifdef CONFIG_9P_FSCACHE v9ses->cachetag = NULL; #endif v9ses->session_lock_timeout = P9_LOCK_TIMEOUT; if (!opts) return 0; tmp_options = kstrdup(opts, GFP_KERNEL); if (!tmp_options) { ret = -ENOMEM; goto fail_option_alloc; } options = tmp_options; while ((p = strsep(&options, ",")) != NULL) { int token, r; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case Opt_debug: r = match_int(&args[0], &option); if (r < 0) { p9_debug(P9_DEBUG_ERROR, "integer field, but no integer?\n"); ret = r; } else { v9ses->debug = option; #ifdef CONFIG_NET_9P_DEBUG p9_debug_level = option; #endif } break; case Opt_dfltuid: r = match_int(&args[0], &option); if (r < 0) { p9_debug(P9_DEBUG_ERROR, "integer field, but no integer?\n"); ret = r; continue; } v9ses->dfltuid = make_kuid(current_user_ns(), option); if (!uid_valid(v9ses->dfltuid)) { p9_debug(P9_DEBUG_ERROR, "uid field, but not a uid?\n"); ret = -EINVAL; } break; case Opt_dfltgid: r = match_int(&args[0], &option); if (r < 0) { p9_debug(P9_DEBUG_ERROR, "integer field, but no integer?\n"); ret = r; continue; } v9ses->dfltgid = make_kgid(current_user_ns(), option); if (!gid_valid(v9ses->dfltgid)) { p9_debug(P9_DEBUG_ERROR, "gid field, but not a gid?\n"); ret = -EINVAL; } break; case Opt_afid: r = match_int(&args[0], &option); if (r < 0) { p9_debug(P9_DEBUG_ERROR, "integer field, but no integer?\n"); ret = r; } else { v9ses->afid = option; } break; case Opt_uname: kfree(v9ses->uname); v9ses->uname = match_strdup(&args[0]); if (!v9ses->uname) { ret = -ENOMEM; goto free_and_return; } break; case Opt_remotename: kfree(v9ses->aname); v9ses->aname = match_strdup(&args[0]); if (!v9ses->aname) { ret = -ENOMEM; goto free_and_return; } break; case Opt_nodevmap: v9ses->nodev = 1; break; case Opt_noxattr: v9ses->flags |= V9FS_NO_XATTR; break; case Opt_directio: v9ses->flags |= V9FS_DIRECT_IO; break; case Opt_ignoreqv: v9ses->flags |= V9FS_IGNORE_QV; break; case Opt_cachetag: #ifdef CONFIG_9P_FSCACHE kfree(v9ses->cachetag); v9ses->cachetag = match_strdup(&args[0]); if (!v9ses->cachetag) { ret = -ENOMEM; goto free_and_return; } #endif break; case Opt_cache: s = match_strdup(&args[0]); if (!s) { ret = -ENOMEM; p9_debug(P9_DEBUG_ERROR, "problem allocating copy of cache arg\n"); goto free_and_return; } r = get_cache_mode(s); if (r < 0) ret = r; else v9ses->cache = r; kfree(s); break; case Opt_access: s = match_strdup(&args[0]); if (!s) { ret = -ENOMEM; p9_debug(P9_DEBUG_ERROR, "problem allocating copy of access arg\n"); goto free_and_return; } v9ses->flags &= ~V9FS_ACCESS_MASK; if (strcmp(s, "user") == 0) v9ses->flags |= V9FS_ACCESS_USER; else if (strcmp(s, "any") == 0) v9ses->flags |= V9FS_ACCESS_ANY; else if (strcmp(s, "client") == 0) { v9ses->flags |= V9FS_ACCESS_CLIENT; } else { uid_t uid; v9ses->flags |= V9FS_ACCESS_SINGLE; r = kstrtouint(s, 10, &uid); if (r) { ret = r; pr_info("Unknown access argument %s: %d\n", s, r); kfree(s); continue; } v9ses->uid = make_kuid(current_user_ns(), uid); if (!uid_valid(v9ses->uid)) { ret = -EINVAL; pr_info("Unknown uid %s\n", s); } } kfree(s); break; case Opt_posixacl: #ifdef CONFIG_9P_FS_POSIX_ACL v9ses->flags |= V9FS_POSIX_ACL; #else p9_debug(P9_DEBUG_ERROR, "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n"); #endif break; case Opt_locktimeout: r = match_int(&args[0], &option); if (r < 0) { p9_debug(P9_DEBUG_ERROR, "integer field, but no integer?\n"); ret = r; continue; } if (option < 1) { p9_debug(P9_DEBUG_ERROR, "locktimeout must be a greater than zero integer.\n"); ret = -EINVAL; continue; } v9ses->session_lock_timeout = (long)option * HZ; break; default: continue; } } free_and_return: kfree(tmp_options); fail_option_alloc: return ret; } /** * v9fs_session_init - initialize session * @v9ses: session information structure * @dev_name: device being mounted * @data: options * */ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses, const char *dev_name, char *data) { struct p9_fid *fid; int rc = -ENOMEM; v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL); if (!v9ses->uname) goto err_names; v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL); if (!v9ses->aname) goto err_names; init_rwsem(&v9ses->rename_sem); v9ses->uid = INVALID_UID; v9ses->dfltuid = V9FS_DEFUID; v9ses->dfltgid = V9FS_DEFGID; v9ses->clnt = p9_client_create(dev_name, data); if (IS_ERR(v9ses->clnt)) { rc = PTR_ERR(v9ses->clnt); p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n"); goto err_names; } v9ses->flags = V9FS_ACCESS_USER; if (p9_is_proto_dotl(v9ses->clnt)) { v9ses->flags = V9FS_ACCESS_CLIENT; v9ses->flags |= V9FS_PROTO_2000L; } else if (p9_is_proto_dotu(v9ses->clnt)) { v9ses->flags |= V9FS_PROTO_2000U; } rc = v9fs_parse_options(v9ses, data); if (rc < 0) goto err_clnt; v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ; if (!v9fs_proto_dotl(v9ses) && ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) { /* * We support ACCESS_CLIENT only for dotl. * Fall back to ACCESS_USER */ v9ses->flags &= ~V9FS_ACCESS_MASK; v9ses->flags |= V9FS_ACCESS_USER; } /*FIXME !! */ /* for legacy mode, fall back to V9FS_ACCESS_ANY */ if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) && ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) { v9ses->flags &= ~V9FS_ACCESS_MASK; v9ses->flags |= V9FS_ACCESS_ANY; v9ses->uid = INVALID_UID; } if (!v9fs_proto_dotl(v9ses) || !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) { /* * We support ACL checks on clinet only if the protocol is * 9P2000.L and access is V9FS_ACCESS_CLIENT. */ v9ses->flags &= ~V9FS_ACL_MASK; } fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID, v9ses->aname); if (IS_ERR(fid)) { rc = PTR_ERR(fid); p9_debug(P9_DEBUG_ERROR, "cannot attach\n"); goto err_clnt; } if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE) fid->uid = v9ses->uid; else fid->uid = INVALID_UID; #ifdef CONFIG_9P_FSCACHE /* register the session for caching */ if (v9ses->cache & CACHE_FSCACHE) { rc = v9fs_cache_session_get_cookie(v9ses, dev_name); if (rc < 0) goto err_clnt; } #endif spin_lock(&v9fs_sessionlist_lock); list_add(&v9ses->slist, &v9fs_sessionlist); spin_unlock(&v9fs_sessionlist_lock); return fid; err_clnt: #ifdef CONFIG_9P_FSCACHE kfree(v9ses->cachetag); #endif p9_client_destroy(v9ses->clnt); err_names: kfree(v9ses->uname); kfree(v9ses->aname); return ERR_PTR(rc); } /** * v9fs_session_close - shutdown a session * @v9ses: session information structure * */ void v9fs_session_close(struct v9fs_session_info *v9ses) { if (v9ses->clnt) { p9_client_destroy(v9ses->clnt); v9ses->clnt = NULL; } #ifdef CONFIG_9P_FSCACHE fscache_relinquish_volume(v9fs_session_cache(v9ses), NULL, false); kfree(v9ses->cachetag); #endif kfree(v9ses->uname); kfree(v9ses->aname); spin_lock(&v9fs_sessionlist_lock); list_del(&v9ses->slist); spin_unlock(&v9fs_sessionlist_lock); } /** * v9fs_session_cancel - terminate a session * @v9ses: session to terminate * * mark transport as disconnected and cancel all pending requests. */ void v9fs_session_cancel(struct v9fs_session_info *v9ses) { p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses); p9_client_disconnect(v9ses->clnt); } /** * v9fs_session_begin_cancel - Begin terminate of a session * @v9ses: session to terminate * * After this call we don't allow any request other than clunk. */ void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses) { p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses); p9_client_begin_disconnect(v9ses->clnt); } static struct kobject *v9fs_kobj; #ifdef CONFIG_9P_FSCACHE /* * List caches associated with a session */ static ssize_t caches_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { ssize_t n = 0, count = 0, limit = PAGE_SIZE; struct v9fs_session_info *v9ses; spin_lock(&v9fs_sessionlist_lock); list_for_each_entry(v9ses, &v9fs_sessionlist, slist) { if (v9ses->cachetag) { n = snprintf(buf, limit, "%s\n", v9ses->cachetag); if (n < 0) { count = n; break; } count += n; limit -= n; } } spin_unlock(&v9fs_sessionlist_lock); return count; } static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches); #endif /* CONFIG_9P_FSCACHE */ static struct attribute *v9fs_attrs[] = { #ifdef CONFIG_9P_FSCACHE &v9fs_attr_cache.attr, #endif NULL, }; static const struct attribute_group v9fs_attr_group = { .attrs = v9fs_attrs, }; /** * v9fs_sysfs_init - Initialize the v9fs sysfs interface * */ static int __init v9fs_sysfs_init(void) { v9fs_kobj = kobject_create_and_add("9p", fs_kobj); if (!v9fs_kobj) return -ENOMEM; if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) { kobject_put(v9fs_kobj); return -ENOMEM; } return 0; } /** * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface * */ static void v9fs_sysfs_cleanup(void) { sysfs_remove_group(v9fs_kobj, &v9fs_attr_group); kobject_put(v9fs_kobj); } static void v9fs_inode_init_once(void *foo) { struct v9fs_inode *v9inode = (struct v9fs_inode *)foo; memset(&v9inode->qid, 0, sizeof(v9inode->qid)); inode_init_once(&v9inode->netfs.inode); } /** * v9fs_init_inode_cache - initialize a cache for 9P * Returns 0 on success. */ static int v9fs_init_inode_cache(void) { v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache", sizeof(struct v9fs_inode), 0, (SLAB_RECLAIM_ACCOUNT| SLAB_ACCOUNT), v9fs_inode_init_once); if (!v9fs_inode_cache) return -ENOMEM; return 0; } /** * v9fs_destroy_inode_cache - destroy the cache of 9P inode * */ static void v9fs_destroy_inode_cache(void) { /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); kmem_cache_destroy(v9fs_inode_cache); } /** * init_v9fs - Initialize module * */ static int __init init_v9fs(void) { int err; pr_info("Installing v9fs 9p2000 file system support\n"); /* TODO: Setup list of registered trasnport modules */ err = v9fs_init_inode_cache(); if (err < 0) { pr_err("Failed to register v9fs for caching\n"); return err; } err = v9fs_sysfs_init(); if (err < 0) { pr_err("Failed to register with sysfs\n"); goto out_cache; } err = register_filesystem(&v9fs_fs_type); if (err < 0) { pr_err("Failed to register filesystem\n"); goto out_sysfs_cleanup; } return 0; out_sysfs_cleanup: v9fs_sysfs_cleanup(); out_cache: v9fs_destroy_inode_cache(); return err; } /** * exit_v9fs - shutdown module * */ static void __exit exit_v9fs(void) { v9fs_sysfs_cleanup(); v9fs_destroy_inode_cache(); unregister_filesystem(&v9fs_fs_type); } module_init(init_v9fs) module_exit(exit_v9fs) MODULE_AUTHOR("Latchesar Ionkov "); MODULE_AUTHOR("Eric Van Hensbergen "); MODULE_AUTHOR("Ron Minnich "); MODULE_DESCRIPTION("9P Client File System"); MODULE_LICENSE("GPL");