| /* |
| * 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 |
| * |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #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); |
| 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_trans, Opt_cache, Opt_cachetag, |
| /* Options that take no arguments */ |
| Opt_nodevmap, |
| /* Cache options */ |
| Opt_cache_loose, Opt_fscache, |
| /* Access options */ |
| Opt_access, Opt_posixacl, |
| /* 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_posixacl, "posixacl"}, |
| {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_LOOSE; |
| p9_debug(P9_DEBUG_9P, "Cache mode: loose\n"); |
| } else if (!strcmp(s, "fscache")) { |
| version = CACHE_FSCACHE; |
| p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n"); |
| } else if (!strcmp(s, "none")) { |
| version = CACHE_NONE; |
| p9_debug(P9_DEBUG_9P, "Cache mode: none\n"); |
| } else |
| pr_info("Unknown Cache mode %s\n", s); |
| return version; |
| } |
| |
| /** |
| * 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 = CACHE_NONE; |
| #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, 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; |
| continue; |
| } |
| 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 = option; |
| 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 = option; |
| 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; |
| continue; |
| } |
| 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_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_debug(P9_DEBUG_ERROR, |
| "problem allocating copy of cache arg\n"); |
| goto free_and_return; |
| } |
| ret = get_cache_mode(s); |
| if (ret == -EINVAL) { |
| kfree(s); |
| goto free_and_return; |
| } |
| |
| v9ses->cache = ret; |
| 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 { |
| v9ses->flags |= V9FS_ACCESS_SINGLE; |
| v9ses->uid = simple_strtoul(s, &e, 10); |
| if (*e != '\0') { |
| ret = -EINVAL; |
| pr_info("Unknown access argument %s\n", |
| s); |
| kfree(s); |
| goto free_and_return; |
| } |
| } |
| |
| 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; |
| |
| 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 = kstrdup(V9FS_DEFUSER, GFP_KERNEL); |
| if (!v9ses->uname) |
| return ERR_PTR(-ENOMEM); |
| |
| v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL); |
| if (!v9ses->aname) { |
| kfree(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) { |
| kfree(v9ses->aname); |
| kfree(v9ses->uname); |
| return ERR_PTR(rc); |
| } |
| |
| spin_lock(&v9fs_sessionlist_lock); |
| list_add(&v9ses->slist, &v9fs_sessionlist); |
| spin_unlock(&v9fs_sessionlist_lock); |
| |
| v9ses->uid = ~0; |
| v9ses->dfltuid = V9FS_DEFUID; |
| v9ses->dfltgid = V9FS_DEFGID; |
| |
| v9ses->clnt = p9_client_create(dev_name, data); |
| if (IS_ERR(v9ses->clnt)) { |
| retval = PTR_ERR(v9ses->clnt); |
| v9ses->clnt = NULL; |
| p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n"); |
| goto error; |
| } |
| |
| 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) { |
| retval = rc; |
| goto error; |
| } |
| |
| 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; |
| } |
| 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)) { |
| retval = PTR_ERR(fid); |
| fid = NULL; |
| p9_debug(P9_DEBUG_ERROR, "cannot attach\n"); |
| goto error; |
| } |
| |
| 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 */ |
| 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 |
| kfree(v9ses->uname); |
| kfree(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_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); |
| } |
| |
| 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); |
| } |
| |
| static void v9fs_inode_init_once(void *foo) |
| { |
| struct v9fs_inode *v9inode = (struct v9fs_inode *)foo; |
| #ifdef CONFIG_9P_FSCACHE |
| v9inode->fscache = NULL; |
| #endif |
| memset(&v9inode->qid, 0, sizeof(v9inode->qid)); |
| inode_init_once(&v9inode->vfs_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_MEM_SPREAD), |
| 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); |
| } |
| |
| static int v9fs_cache_register(void) |
| { |
| int ret; |
| ret = v9fs_init_inode_cache(); |
| if (ret < 0) |
| return ret; |
| #ifdef CONFIG_9P_FSCACHE |
| return fscache_register_netfs(&v9fs_cache_netfs); |
| #else |
| return ret; |
| #endif |
| } |
| |
| static void v9fs_cache_unregister(void) |
| { |
| v9fs_destroy_inode_cache(); |
| #ifdef CONFIG_9P_FSCACHE |
| fscache_unregister_netfs(&v9fs_cache_netfs); |
| #endif |
| } |
| |
| /** |
| * 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_cache_register(); |
| 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_cache_unregister(); |
| |
| 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"); |