/*
* linux/fs/9p/v9fs.c
*
* This file contains functions assisting in mapping VFS to 9P2000
*
* Copyright (C) 2004 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 "debug.h"
#include "v9fs.h"
#include "9p.h"
#include "v9fs_vfs.h"
#include "transport.h"
#include "mux.h"
/* TODO: sysfs or debugfs interface */
int v9fs_debug_level = 0; /* feature-rific global debug level */
/*
* Option Parsing (code inspired by NFS code)
*
*/
enum {
/* Options that take integer arguments */
Opt_port, Opt_msize, Opt_uid, Opt_gid, Opt_afid, Opt_debug,
Opt_rfdno, Opt_wfdno,
/* String options */
Opt_uname, Opt_remotename,
/* Options that take no arguments */
Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd,
/* Error token */
Opt_err
};
static match_table_t tokens = {
{Opt_port, "port=%u"},
{Opt_msize, "msize=%u"},
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_afid, "afid=%u"},
{Opt_rfdno, "rfdno=%u"},
{Opt_wfdno, "wfdno=%u"},
{Opt_debug, "debug=%x"},
{Opt_uname, "uname=%s"},
{Opt_remotename, "aname=%s"},
{Opt_unix, "proto=unix"},
{Opt_tcp, "proto=tcp"},
{Opt_fd, "proto=fd"},
{Opt_tcp, "tcp"},
{Opt_unix, "unix"},
{Opt_fd, "fd"},
{Opt_legacy, "noextend"},
{Opt_nodevmap, "nodevmap"},
{Opt_err, NULL}
};
/*
* Parse option string.
*/
/**
* 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(char *options, struct v9fs_session_info *v9ses)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
int ret;
/* setup defaults */
v9ses->port = V9FS_PORT;
v9ses->maxdata = 9000;
v9ses->proto = PROTO_TCP;
v9ses->extended = 1;
v9ses->afid = ~0;
v9ses->debug = 0;
v9ses->rfdno = ~0;
v9ses->wfdno = ~0;
if (!options)
return;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
if (token < Opt_uname) {
if ((ret = match_int(&args[0], &option)) < 0) {
dprintk(DEBUG_ERROR,
"integer field, but no integer?\n");
continue;
}
}
switch (token) {
case Opt_port:
v9ses->port = option;
break;
case Opt_msize:
v9ses->maxdata = option;
break;
case Opt_uid:
v9ses->uid = option;
break;
case Opt_gid:
v9ses->gid = option;
break;
case Opt_afid:
v9ses->afid = option;
break;
case Opt_rfdno:
v9ses->rfdno = option;
break;
case Opt_wfdno:
v9ses->wfdno = option;
break;
case Opt_debug:
v9ses->debug = option;
break;
case Opt_tcp:
v9ses->proto = PROTO_TCP;
break;
case Opt_unix:
v9ses->proto = PROTO_UNIX;
break;
case Opt_fd:
v9ses->proto = PROTO_FD;
break;
case Opt_uname:
match_strcpy(v9ses->name, &args[0]);
break;
case Opt_remotename:
match_strcpy(v9ses->remotename, &args[0]);
break;
case Opt_legacy:
v9ses->extended = 0;
break;
case Opt_nodevmap:
v9ses->nodev = 1;
break;
default:
continue;
}
}
}
/**
* v9fs_inode2v9ses - safely extract v9fs session info from super block
* @inode: inode to extract information from
*
* Paranoid function to extract v9ses information from superblock,
* if anything is missing it will report an error.
*
*/
struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
{
return (inode->i_sb->s_fs_info);
}
/**
* v9fs_get_idpool - allocate numeric id from pool
* @p - pool to allocate from
*
* XXX - This seems to be an awful generic function, should it be in idr.c with
* the lock included in struct idr?
*/
int v9fs_get_idpool(struct v9fs_idpool *p)
{
int i = 0;
int error;
retry:
if (idr_pre_get(&p->pool, GFP_KERNEL) == 0)
return 0;
if (down_interruptible(&p->lock) == -EINTR) {
eprintk(KERN_WARNING, "Interrupted while locking\n");
return -1;
}
/* no need to store exactly p, we just need something non-null */
error = idr_get_new(&p->pool, p, &i);
up(&p->lock);
if (error == -EAGAIN)
goto retry;
else if (error)
return -1;
return i;
}
/**
* v9fs_put_idpool - release numeric id from pool
* @p - pool to allocate from
*
* XXX - This seems to be an awful generic function, should it be in idr.c with
* the lock included in struct idr?
*/
void v9fs_put_idpool(int id, struct v9fs_idpool *p)
{
if (down_interruptible(&p->lock) == -EINTR) {
eprintk(KERN_WARNING, "Interrupted while locking\n");
return;
}
idr_remove(&p->pool, id);
up(&p->lock);
}
/**
* v9fs_check_idpool - check if the specified id is available
* @id - id to check
* @p - pool
*/
int v9fs_check_idpool(int id, struct v9fs_idpool *p)
{
return idr_find(&p->pool, id) != NULL;
}
/**
* v9fs_session_init - initialize session
* @v9ses: session information structure
* @dev_name: device being mounted
* @data: options
*
*/
int
v9fs_session_init(struct v9fs_session_info *v9ses,
const char *dev_name, char *data)
{
struct v9fs_fcall *fcall = NULL;
struct v9fs_transport *trans_proto;
int n = 0;
int newfid = -1;
int retval = -EINVAL;
struct v9fs_str *version;
v9ses->name = __getname();
if (!v9ses->name)
return -ENOMEM;
v9ses->remotename = __getname();
if (!v9ses->remotename) {
__putname(v9ses->name);
return -ENOMEM;
}
strcpy(v9ses->name, V9FS_DEFUSER);
strcpy(v9ses->remotename, V9FS_DEFANAME);
v9fs_parse_options(data, v9ses);
/* set global debug level */
v9fs_debug_level = v9ses->debug;
/* id pools that are session-dependent: fids and tags */
idr_init(&v9ses->fidpool.pool);
init_MUTEX(&v9ses->fidpool.lock);
switch (v9ses->proto) {
case PROTO_TCP:
trans_proto = &v9fs_trans_tcp;
break;
case PROTO_UNIX:
trans_proto = &v9fs_trans_unix;
*v9ses->remotename = 0;
break;
case PROTO_FD:
trans_proto = &v9fs_trans_fd;
*v9ses->remotename = 0;
break;
default:
printk(KERN_ERR "v9fs: Bad mount protocol %d\n", v9ses->proto);
retval = -ENOPROTOOPT;
goto SessCleanUp;
};
v9ses->transport = kmalloc(sizeof(*v9ses->transport), GFP_KERNEL);
if (!v9ses->transport) {
retval = -ENOMEM;
goto SessCleanUp;
}
memmove(v9ses->transport, trans_proto, sizeof(*v9ses->transport));
if ((retval = v9ses->transport->init(v9ses, dev_name, data)) < 0) {
eprintk(KERN_ERR, "problem initializing transport\n");
goto SessCleanUp;
}
v9ses->inprogress = 0;
v9ses->shutdown = 0;
v9ses->session_hung = 0;
v9ses->mux = v9fs_mux_init(v9ses->transport, v9ses->maxdata + V9FS_IOHDRSZ,
&v9ses->extended);
if (IS_ERR(v9ses->mux)) {
retval = PTR_ERR(v9ses->mux);
v9ses->mux = NULL;
dprintk(DEBUG_ERROR, "problem initializing mux\n");
goto SessCleanUp;
}
if (v9ses->afid == ~0) {
if (v9ses->extended)
retval =
v9fs_t_version(v9ses, v9ses->maxdata, "9P2000.u",
&fcall);
else
retval = v9fs_t_version(v9ses, v9ses->maxdata, "9P2000",
&fcall);
if (retval < 0) {
dprintk(DEBUG_ERROR, "v9fs_t_version failed\n");
goto FreeFcall;
}
version = &fcall->params.rversion.version;
if (version->len==8 && !memcmp(version->str, "9P2000.u", 8)) {
dprintk(DEBUG_9P, "9P2000 UNIX extensions enabled\n");
v9ses->extended = 1;
} else if (version->len==6 && !memcmp(version->str, "9P2000", 6)) {
dprintk(DEBUG_9P, "9P2000 legacy mode enabled\n");
v9ses->extended = 0;
} else {
retval = -EREMOTEIO;
goto FreeFcall;
}
n = fcall->params.rversion.msize;
kfree(fcall);
if (n < v9ses->maxdata)
v9ses->maxdata = n;
}
newfid = v9fs_get_idpool(&v9ses->fidpool);
if (newfid < 0) {
eprintk(KERN_WARNING, "couldn't allocate FID\n");
retval = -ENOMEM;
goto SessCleanUp;
}
/* it is a little bit ugly, but we have to prevent newfid */
/* being the same as afid, so if it is, get a new fid */
if (v9ses->afid != ~0 && newfid == v9ses->afid) {
newfid = v9fs_get_idpool(&v9ses->fidpool);
if (newfid < 0) {
eprintk(KERN_WARNING, "couldn't allocate FID\n");
retval = -ENOMEM;
goto SessCleanUp;
}
}
if ((retval =
v9fs_t_attach(v9ses, v9ses->name, v9ses->remotename, newfid,
v9ses->afid, NULL))
< 0) {
dprintk(DEBUG_ERROR, "cannot attach\n");
goto SessCleanUp;
}
if (v9ses->afid != ~0) {
dprintk(DEBUG_ERROR, "afid not equal to ~0\n");
if (v9fs_t_clunk(v9ses, v9ses->afid))
dprintk(DEBUG_ERROR, "clunk failed\n");
}
return newfid;
FreeFcall:
kfree(fcall);
SessCleanUp:
v9fs_session_close(v9ses);
return retval;
}
/**
* v9fs_session_close - shutdown a session
* @v9ses: session information structure
*
*/
void v9fs_session_close(struct v9fs_session_info *v9ses)
{
if (v9ses->mux) {
v9fs_mux_destroy(v9ses->mux);
v9ses->mux = NULL;
}
if (v9ses->transport) {
v9ses->transport->close(v9ses->transport);
kfree(v9ses->transport);
v9ses->transport = NULL;
}
__putname(v9ses->name);
__putname(v9ses->remotename);
}
/**
* v9fs_session_cancel - mark transport as disconnected
* and cancel all pending requests.
*/
void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
dprintk(DEBUG_ERROR, "cancel session %p\n", v9ses);
v9ses->transport->status = Disconnected;
v9fs_mux_cancel(v9ses->mux, -EIO);
}
extern int v9fs_error_init(void);
/**
* v9fs_init - Initialize module
*
*/
static int __init init_v9fs(void)
{
int ret;
v9fs_error_init();
printk(KERN_INFO "Installing v9fs 9P2000 file system support\n");
ret = v9fs_mux_global_init();
if (!ret)
return ret;
ret = register_filesystem(&v9fs_fs_type);
if (!ret)
v9fs_mux_global_exit();
return ret;
}
/**
* v9fs_init - shutdown module
*
*/
static void __exit exit_v9fs(void)
{
v9fs_mux_global_exit();
unregister_filesystem(&v9fs_fs_type);
}
module_init(init_v9fs)
module_exit(exit_v9fs)
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
MODULE_LICENSE("GPL");
