WSL2-Linux-Kernel/fs/9p/v9fs.c

298 строки
6.5 KiB
C

/*
* 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 <net/9p/9p.h>
#include <net/9p/transport.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
/*
* 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,
/* Options that take no arguments */
Opt_nodevmap,
/* Cache options */
Opt_cache_loose,
/* Access options */
Opt_access,
/* Error token */
Opt_err
};
static 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_loose, "cache=loose"},
{Opt_cache_loose, "loose"},
{Opt_access, "access=%s"},
{Opt_err, NULL}
};
/**
* v9fs_parse_options - parse mount options into session structure
* @options: options string passed from mount
* @v9ses: existing v9fs session information
*
*/
static void v9fs_parse_options(struct v9fs_session_info *v9ses)
{
char *options;
substring_t args[MAX_OPT_ARGS];
char *p;
int option = 0;
char *s, *e;
int ret;
/* setup defaults */
v9ses->afid = ~0;
v9ses->debug = 0;
v9ses->cache = 0;
if (!v9ses->options)
return;
options = kstrdup(v9ses->options, GFP_KERNEL);
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
if (token < Opt_uname) {
ret = match_int(&args[0], &option);
if (ret < 0) {
P9_DPRINTK(P9_DEBUG_ERROR,
"integer field, but no integer?\n");
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_strcpy(v9ses->uname, &args[0]);
break;
case Opt_remotename:
match_strcpy(v9ses->aname, &args[0]);
break;
case Opt_nodevmap:
v9ses->nodev = 1;
break;
case Opt_cache_loose:
v9ses->cache = CACHE_LOOSE;
break;
case Opt_access:
s = match_strdup(&args[0]);
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 {
v9ses->flags |= V9FS_ACCESS_SINGLE;
v9ses->uid = simple_strtol(s, &e, 10);
if (*e != '\0')
v9ses->uid = ~0;
}
kfree(s);
break;
default:
continue;
}
}
kfree(options);
}
/**
* 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;
v9ses->uname = __getname();
if (!v9ses->uname)
return ERR_PTR(-ENOMEM);
v9ses->aname = __getname();
if (!v9ses->aname) {
__putname(v9ses->uname);
return ERR_PTR(-ENOMEM);
}
v9ses->flags = V9FS_EXTENDED | V9FS_ACCESS_USER;
strcpy(v9ses->uname, V9FS_DEFUSER);
strcpy(v9ses->aname, V9FS_DEFANAME);
v9ses->uid = ~0;
v9ses->dfltuid = V9FS_DEFUID;
v9ses->dfltgid = V9FS_DEFGID;
v9ses->options = kstrdup(data, GFP_KERNEL);
v9fs_parse_options(v9ses);
v9ses->clnt = p9_client_create(dev_name, v9ses->options);
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 (!v9ses->clnt->dotu)
v9ses->flags &= ~V9FS_EXTENDED;
v9ses->maxdata = v9ses->clnt->msize;
/* for legacy mode, fall back to V9FS_ACCESS_ANY */
if (!v9fs_extended(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;
return fid;
error:
v9fs_session_close(v9ses);
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;
}
__putname(v9ses->uname);
__putname(v9ses->aname);
kfree(v9ses->options);
}
/**
* v9fs_session_cancel - 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);
}
extern int v9fs_error_init(void);
/**
* v9fs_init - Initialize module
*
*/
static int __init init_v9fs(void)
{
printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
/* TODO: Setup list of registered trasnport modules */
return register_filesystem(&v9fs_fs_type);
}
/**
* v9fs_init - shutdown module
*
*/
static void __exit exit_v9fs(void)
{
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");