/* * linux/fs/9p/v9fs.c * * This file contains functions assisting in mapping VFS to 9P2000 * * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com> * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to: * Free Software Foundation * 51 Franklin Street, Fifth Floor * Boston, MA 02111-1301 USA * */ #include <linux/module.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/sched.h> #include <linux/parser.h> #include <linux/idr.h> #include <linux/slab.h> #include <net/9p/9p.h> #include <net/9p/client.h> #include <net/9p/transport.h> #include "v9fs.h" #include "v9fs_vfs.h" #include "cache.h" static DEFINE_SPINLOCK(v9fs_sessionlist_lock); static LIST_HEAD(v9fs_sessionlist); /* * 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_trans, Opt_cache, Opt_cachetag, /* Options that take no arguments */ Opt_nodevmap, /* Cache options */ Opt_cache_loose, Opt_fscache, /* Access options */ Opt_access, /* 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_cache, "cache=%s"}, {Opt_cache_loose, "loose"}, {Opt_fscache, "fscache"}, {Opt_cachetag, "cachetag=%s"}, {Opt_access, "access=%s"}, {Opt_err, NULL} }; /** * v9fs_parse_options - parse mount options into session structure * @v9ses: existing v9fs session information * * 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, *e; int ret = 0; /* setup defaults */ v9ses->afid = ~0; v9ses->debug = 0; v9ses->cache = 0; #ifdef CONFIG_9P_FSCACHE v9ses->cachetag = NULL; #endif 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; if (!*p) continue; token = match_token(p, tokens, args); if (token < Opt_uname) { int r = match_int(&args[0], &option); if (r < 0) { P9_DPRINTK(P9_DEBUG_ERROR, "integer field, but no integer?\n"); ret = r; continue; } } switch (token) { case Opt_debug: v9ses->debug = option; #ifdef CONFIG_NET_9P_DEBUG p9_debug_level = option; #endif break; case Opt_dfltuid: v9ses->dfltuid = option; break; case Opt_dfltgid: v9ses->dfltgid = option; break; case Opt_afid: v9ses->afid = option; break; case Opt_uname: match_strlcpy(v9ses->uname, &args[0], PATH_MAX); break; case Opt_remotename: match_strlcpy(v9ses->aname, &args[0], PATH_MAX); break; case Opt_nodevmap: v9ses->nodev = 1; break; case Opt_cache_loose: v9ses->cache = CACHE_LOOSE; break; case Opt_fscache: v9ses->cache = CACHE_FSCACHE; break; case Opt_cachetag: #ifdef CONFIG_9P_FSCACHE v9ses->cachetag = match_strdup(&args[0]); #endif break; case Opt_cache: s = match_strdup(&args[0]); if (!s) { ret = -ENOMEM; P9_DPRINTK(P9_DEBUG_ERROR, "problem allocating copy of cache arg\n"); goto free_and_return; } if (strcmp(s, "loose") == 0) v9ses->cache = CACHE_LOOSE; else if (strcmp(s, "fscache") == 0) v9ses->cache = CACHE_FSCACHE; else v9ses->cache = CACHE_NONE; kfree(s); break; case Opt_access: s = match_strdup(&args[0]); if (!s) { ret = -ENOMEM; P9_DPRINTK(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) { #ifdef CONFIG_9P_FS_POSIX_ACL v9ses->flags |= V9FS_ACCESS_CLIENT; #else P9_DPRINTK(P9_DEBUG_ERROR, "access=client option not supported\n"); kfree(s); ret = -EINVAL; goto free_and_return; #endif } else { v9ses->flags |= V9FS_ACCESS_SINGLE; v9ses->uid = simple_strtoul(s, &e, 10); if (*e != '\0') v9ses->uid = ~0; } kfree(s); 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) { int retval = -EINVAL; struct p9_fid *fid; int rc; v9ses->uname = __getname(); if (!v9ses->uname) return ERR_PTR(-ENOMEM); v9ses->aname = __getname(); if (!v9ses->aname) { __putname(v9ses->uname); return ERR_PTR(-ENOMEM); } init_rwsem(&v9ses->rename_sem); rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY); if (rc) { __putname(v9ses->aname); __putname(v9ses->uname); return ERR_PTR(rc); } spin_lock(&v9fs_sessionlist_lock); list_add(&v9ses->slist, &v9fs_sessionlist); spin_unlock(&v9fs_sessionlist_lock); v9ses->flags = V9FS_ACCESS_USER; strcpy(v9ses->uname, V9FS_DEFUSER); strcpy(v9ses->aname, V9FS_DEFANAME); v9ses->uid = ~0; v9ses->dfltuid = V9FS_DEFUID; v9ses->dfltgid = V9FS_DEFGID; rc = v9fs_parse_options(v9ses, data); if (rc < 0) { retval = rc; goto error; } v9ses->clnt = p9_client_create(dev_name, data); if (IS_ERR(v9ses->clnt)) { retval = PTR_ERR(v9ses->clnt); v9ses->clnt = NULL; P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n"); goto error; } if (p9_is_proto_dotl(v9ses->clnt)) v9ses->flags |= V9FS_PROTO_2000L; else if (p9_is_proto_dotu(v9ses->clnt)) v9ses->flags |= V9FS_PROTO_2000U; 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 = ~0; } fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0, v9ses->aname); if (IS_ERR(fid)) { retval = PTR_ERR(fid); fid = NULL; P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n"); goto error; } if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE) fid->uid = v9ses->uid; else fid->uid = ~0; #ifdef CONFIG_9P_FSCACHE /* register the session for caching */ v9fs_cache_session_get_cookie(v9ses); #endif return fid; error: bdi_destroy(&v9ses->bdi); return ERR_PTR(retval); } /** * 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 if (v9ses->fscache) { v9fs_cache_session_put_cookie(v9ses); kfree(v9ses->cachetag); } #endif __putname(v9ses->uname); __putname(v9ses->aname); bdi_destroy(&v9ses->bdi); 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_DPRINTK(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_DPRINTK(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses); p9_client_begin_disconnect(v9ses->clnt); } extern int v9fs_error_init(void); static struct kobject *v9fs_kobj; #ifdef CONFIG_9P_FSCACHE /** * caches_show - list caches associated with a session * * Returns the size of buffer written. */ 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 struct attribute_group v9fs_attr_group = { .attrs = v9fs_attrs, }; /** * v9fs_sysfs_init - Initialize the v9fs sysfs interface * */ static int 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); } /** * init_v9fs - Initialize module * */ static int __init init_v9fs(void) { int err; printk(KERN_INFO "Installing v9fs 9p2000 file system support\n"); /* TODO: Setup list of registered trasnport modules */ err = register_filesystem(&v9fs_fs_type); if (err < 0) { printk(KERN_ERR "Failed to register filesystem\n"); return err; } err = v9fs_cache_register(); if (err < 0) { printk(KERN_ERR "Failed to register v9fs for caching\n"); goto out_fs_unreg; } err = v9fs_sysfs_init(); if (err < 0) { printk(KERN_ERR "Failed to register with sysfs\n"); goto out_sysfs_cleanup; } return 0; out_sysfs_cleanup: v9fs_sysfs_cleanup(); out_fs_unreg: unregister_filesystem(&v9fs_fs_type); return err; } /** * exit_v9fs - shutdown module * */ static void __exit exit_v9fs(void) { v9fs_sysfs_cleanup(); v9fs_cache_unregister(); unregister_filesystem(&v9fs_fs_type); } module_init(init_v9fs) module_exit(exit_v9fs) MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>"); MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>"); MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>"); MODULE_LICENSE("GPL");