superrob1500
/
mirror-linux
mirror of https://github.com/torvalds/linux
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
mirror-linux/fs/9p/v9fs.c

758 lines
18 KiB
C
Raw Permalink Blame History

// 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 <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*/
#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/cred.h>
#include <linux/fs_parser.h>
#include <linux/fs_context.h>
#include <linux/slab.h>
#include <linux/seq_file.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 {
/* Mount-point source, we need to handle this explicitly because
* the code below accepts unknown args and the vfs layer only handles
* source if we rejected it as EINVAL */
Opt_source,
/* 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,
/* Client options */
Opt_msize, Opt_trans, Opt_legacy, Opt_version,
/* fd transport options */
/* Options that take integer arguments */
Opt_rfdno, Opt_wfdno,
/* Options that take no arguments */
/* rdma transport options */
/* Options that take integer arguments */
Opt_rq_depth, Opt_sq_depth, Opt_timeout,
/* Options for both fd and rdma transports */
Opt_port, Opt_privport,
};
static const struct constant_table p9_versions[] = {
{ "9p2000", p9_proto_legacy },
{ "9p2000.u", p9_proto_2000u },
{ "9p2000.L", p9_proto_2000L },
{}
};
/*
* This structure contains all parameters used for the core code,
* the client, and all the transports.
*/
const struct fs_parameter_spec v9fs_param_spec[] = {
fsparam_string ("source", Opt_source),
fsparam_u32hex ("debug", Opt_debug),
fsparam_uid ("dfltuid", Opt_dfltuid),
fsparam_gid ("dfltgid", Opt_dfltgid),
fsparam_u32 ("afid", Opt_afid),
fsparam_string ("uname", Opt_uname),
fsparam_string ("aname", Opt_remotename),
fsparam_flag ("nodevmap", Opt_nodevmap),
fsparam_flag ("noxattr", Opt_noxattr),
fsparam_flag ("directio", Opt_directio),
fsparam_flag ("ignoreqv", Opt_ignoreqv),
fsparam_string ("cache", Opt_cache),
fsparam_string ("cachetag", Opt_cachetag),
fsparam_string ("access", Opt_access),
fsparam_flag ("posixacl", Opt_posixacl),
fsparam_u32 ("locktimeout", Opt_locktimeout),
/* client options */
fsparam_u32 ("msize", Opt_msize),
fsparam_flag ("noextend", Opt_legacy),
fsparam_string ("trans", Opt_trans),
fsparam_enum ("version", Opt_version, p9_versions),
/* fd transport options */
fsparam_u32 ("rfdno", Opt_rfdno),
fsparam_u32 ("wfdno", Opt_wfdno),
/* rdma transport options */
fsparam_u32 ("sq", Opt_sq_depth),
fsparam_u32 ("rq", Opt_rq_depth),
fsparam_u32 ("timeout", Opt_timeout),
/* fd and rdma transprt options */
fsparam_u32 ("port", Opt_port),
fsparam_flag ("privport", Opt_privport),
{}
};
/* 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_param - parse a mount option into the filesystem context
* @fc: the filesystem context
* @param: the parameter to parse
*
* Return 0 upon success, -ERRNO upon failure.
*/
int v9fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct v9fs_context *ctx = fc->fs_private;
struct fs_parse_result result;
char *s;
int r;
int opt;
struct p9_client_opts *clnt = &ctx->client_opts;
struct p9_fd_opts *fd_opts = &ctx->fd_opts;
struct p9_rdma_opts *rdma_opts = &ctx->rdma_opts;
struct p9_session_opts *session_opts = &ctx->session_opts;
opt = fs_parse(fc, v9fs_param_spec, param, &result);
if (opt < 0) {
/*
* We might like to report bad mount options here, but
* traditionally 9p has ignored unknown mount options
*/
if (opt == -ENOPARAM)
return 0;
return opt;
}
switch (opt) {
case Opt_source:
if (fc->source) {
pr_info("p9: multiple sources not supported\n");
return -EINVAL;
}
fc->source = param->string;
param->string = NULL;
break;
case Opt_debug:
session_opts->debug = result.uint_32;
#ifdef CONFIG_NET_9P_DEBUG
p9_debug_level = result.uint_32;
#endif
break;
case Opt_dfltuid:
session_opts->dfltuid = result.uid;
break;
case Opt_dfltgid:
session_opts->dfltgid = result.gid;
break;
case Opt_afid:
session_opts->afid = result.uint_32;
break;
case Opt_uname:
kfree(session_opts->uname);
session_opts->uname = param->string;
param->string = NULL;
break;
case Opt_remotename:
kfree(session_opts->aname);
session_opts->aname = param->string;
param->string = NULL;
break;
case Opt_nodevmap:
session_opts->nodev = 1;
break;
case Opt_noxattr:
session_opts->flags |= V9FS_NO_XATTR;
break;
case Opt_directio:
session_opts->flags |= V9FS_DIRECT_IO;
break;
case Opt_ignoreqv:
session_opts->flags |= V9FS_IGNORE_QV;
break;
case Opt_cachetag:
#ifdef CONFIG_9P_FSCACHE
kfree(session_opts->cachetag);
session_opts->cachetag = param->string;
param->string = NULL;
#endif
break;
case Opt_cache:
r = get_cache_mode(param->string);
if (r < 0)
return r;
session_opts->cache = r;
break;
case Opt_access:
s = param->string;
session_opts->flags &= ~V9FS_ACCESS_MASK;
if (strcmp(s, "user") == 0) {
session_opts->flags |= V9FS_ACCESS_USER;
} else if (strcmp(s, "any") == 0) {
session_opts->flags |= V9FS_ACCESS_ANY;
} else if (strcmp(s, "client") == 0) {
session_opts->flags |= V9FS_ACCESS_CLIENT;
} else {
uid_t uid;
session_opts->flags |= V9FS_ACCESS_SINGLE;
r = kstrtouint(s, 10, &uid);
if (r) {
pr_info("Unknown access argument %s: %d\n",
param->string, r);
return r;
}
session_opts->uid = make_kuid(current_user_ns(), uid);
if (!uid_valid(session_opts->uid)) {
pr_info("Unknown uid %s\n", s);
return -EINVAL;
}
}
break;
case Opt_posixacl:
#ifdef CONFIG_9P_FS_POSIX_ACL
session_opts->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:
if (result.uint_32 < 1) {
p9_debug(P9_DEBUG_ERROR,
"locktimeout must be a greater than zero integer.\n");
return -EINVAL;
}
session_opts->session_lock_timeout = (long)result.uint_32 * HZ;
break;
/* Options for client */
case Opt_msize:
if (result.uint_32 < 4096) {
p9_debug(P9_DEBUG_ERROR, "msize should be at least 4k\n");
return -EINVAL;
}
if (result.uint_32 > INT_MAX) {
p9_debug(P9_DEBUG_ERROR, "msize too big\n");
return -EINVAL;
}
clnt->msize = result.uint_32;
break;
case Opt_trans:
v9fs_put_trans(clnt->trans_mod);
clnt->trans_mod = v9fs_get_trans_by_name(param->string);
if (!clnt->trans_mod) {
pr_info("Could not find request transport: %s\n",
param->string);
return -EINVAL;
}
break;
case Opt_legacy:
clnt->proto_version = p9_proto_legacy;
break;
case Opt_version:
clnt->proto_version = result.uint_32;
p9_debug(P9_DEBUG_9P, "Protocol version: %s\n", param->string);
break;
/* Options for fd transport */
case Opt_rfdno:
fd_opts->rfd = result.uint_32;
break;
case Opt_wfdno:
fd_opts->wfd = result.uint_32;
break;
/* Options for rdma transport */
case Opt_sq_depth:
rdma_opts->sq_depth = result.uint_32;
break;
case Opt_rq_depth:
rdma_opts->rq_depth = result.uint_32;
break;
case Opt_timeout:
rdma_opts->timeout = result.uint_32;
break;
/* Options for both fd and rdma transports */
case Opt_port:
fd_opts->port = result.uint_32;
rdma_opts->port = result.uint_32;
break;
case Opt_privport:
fd_opts->privport = true;
rdma_opts->port = true;
break;
}
return 0;
}
static void v9fs_apply_options(struct v9fs_session_info *v9ses,
struct fs_context *fc)
{
struct v9fs_context *ctx = fc->fs_private;
v9ses->debug = ctx->session_opts.debug;
v9ses->dfltuid = ctx->session_opts.dfltuid;
v9ses->dfltgid = ctx->session_opts.dfltgid;
v9ses->afid = ctx->session_opts.afid;
v9ses->uname = ctx->session_opts.uname;
ctx->session_opts.uname = NULL;
v9ses->aname = ctx->session_opts.aname;
ctx->session_opts.aname = NULL;
v9ses->nodev = ctx->session_opts.nodev;
/*
* Note that we must |= flags here as session_init already
* set basic flags. This adds in flags from parsed options.
*/
v9ses->flags |= ctx->session_opts.flags;
#ifdef CONFIG_9P_FSCACHE
v9ses->cachetag = ctx->session_opts.cachetag;
ctx->session_opts.cachetag = NULL;
#endif
v9ses->cache = ctx->session_opts.cache;
v9ses->uid = ctx->session_opts.uid;
v9ses->session_lock_timeout = ctx->session_opts.session_lock_timeout;
}
/**
* v9fs_session_init - initialize session
* @v9ses: session information structure
* @fc: the filesystem mount context
*
*/
struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
struct fs_context *fc)
{
struct p9_fid *fid;
int rc = -ENOMEM;
init_rwsem(&v9ses->rename_sem);
v9ses->clnt = p9_client_create(fc);
if (IS_ERR(v9ses->clnt)) {
rc = PTR_ERR(v9ses->clnt);
p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
goto err_names;
}
/*
* Initialize flags on the real v9ses. v9fs_apply_options below
* will |= the additional flags from parsed options.
*/
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;
}
v9fs_apply_options(v9ses, fc);
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 client 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, fc->source);
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 + count, 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)
{
int ret;
v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
if (!v9fs_kobj)
return -ENOMEM;
ret = sysfs_create_group(v9fs_kobj, &v9fs_attr_group);
if (ret) {
kobject_put(v9fs_kobj);
return ret;
}
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 transport 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 <lucho@ionkov.net>");
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
MODULE_DESCRIPTION("9P Client File System");
MODULE_LICENSE("GPL");
Reference in New Issue View Git Blame Copy Permalink