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-rw-r--r--fs/9p/v9fs.c685
1 files changed, 685 insertions, 0 deletions
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
new file mode 100644
index 000000000..620d93489
--- /dev/null
+++ b/fs/9p/v9fs.c
@@ -0,0 +1,685 @@
+/*
+ * 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, Opt_mmap,
+ /* 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_mmap, "mmap"},
+ {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, "mmap")) {
+ version = CACHE_MMAP;
+ p9_debug(P9_DEBUG_9P, "Cache mode: mmap\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 = 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;
+ continue;
+ }
+ 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;
+ continue;
+ }
+ 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_mmap:
+ v9ses->cache = CACHE_MMAP;
+ 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 {
+ uid_t uid;
+ v9ses->flags |= V9FS_ACCESS_SINGLE;
+ 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;
+ }
+ v9ses->uid = make_kuid(current_user_ns(), uid);
+ if (!uid_valid(v9ses->uid)) {
+ ret = -EINVAL;
+ pr_info("Uknown uid %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");
+ 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 = INVALID_UID;
+ 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 = 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)) {
+ 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 __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;
+#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
+ ret = fscache_register_netfs(&v9fs_cache_netfs);
+ if (ret < 0)
+ v9fs_destroy_inode_cache();
+#endif
+ return ret;
+}
+
+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");
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-01 10:45:37 +0000