[linux.git] / fs / 9p / v9fs.c

/*
 *  linux/fs/9p/v9fs.c
 *
 *  This file contains functions assisting in mapping VFS to 9P2000
 *
 *  Copyright (C) 2004 by Eric Van Hensbergen <[email protected]>
 *  Copyright (C) 2002 by Ron Minnich <[email protected]>
 *
 *  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/config.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.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)
		ret = register_filesystem(&v9fs_fs_type);

	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 <[email protected]>");
MODULE_AUTHOR("Ron Minnich <[email protected]>");
MODULE_LICENSE("GPL");
Commit	Line	Data
9e82cf6a EVH	1	/*
	2	* linux/fs/9p/v9fs.c
	3	*
	4	* This file contains functions assisting in mapping VFS to 9P2000
	5	*
	6	* Copyright (C) 2004 by Eric Van Hensbergen <[email protected]>
	7	* Copyright (C) 2002 by Ron Minnich <[email protected]>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
42e8c509 EVH	10	* it under the terms of the GNU General Public License version 2
42e8c509 EVH	11	* as published by the Free Software Foundation.
9e82cf6a EVH	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to:
	20	* Free Software Foundation
	21	* 51 Franklin Street, Fifth Floor
	22	* Boston, MA 02111-1301 USA
	23	*
	24	*/
	25
	26	#include <linux/config.h>
	27	#include <linux/module.h>
	28	#include <linux/errno.h>
	29	#include <linux/fs.h>
	30	#include <linux/parser.h>
	31	#include <linux/idr.h>
	32
	33	#include "debug.h"
	34	#include "v9fs.h"
	35	#include "9p.h"
	36	#include "v9fs_vfs.h"
	37	#include "transport.h"
	38	#include "mux.h"
9e82cf6a EVH	39
	40	/* TODO: sysfs or debugfs interface */
	41	int v9fs_debug_level = 0; /* feature-rific global debug level */
	42
	43	/*
	44	* Option Parsing (code inspired by NFS code)
	45	*
	46	*/
	47
	48	enum {
	49	/* Options that take integer arguments */
	50	Opt_port, Opt_msize, Opt_uid, Opt_gid, Opt_afid, Opt_debug,
	51	Opt_rfdno, Opt_wfdno,
	52	/* String options */
67543e50	53	Opt_uname, Opt_remotename,
9e82cf6a EVH	54	/* Options that take no arguments */
	55	Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd,
	56	/* Error token */
	57	Opt_err
	58	};
	59
	60	static match_table_t tokens = {
	61	{Opt_port, "port=%u"},
	62	{Opt_msize, "msize=%u"},
	63	{Opt_uid, "uid=%u"},
	64	{Opt_gid, "gid=%u"},
	65	{Opt_afid, "afid=%u"},
	66	{Opt_rfdno, "rfdno=%u"},
	67	{Opt_wfdno, "wfdno=%u"},
e1c92117	68	{Opt_debug, "debug=%x"},
67543e50	69	{Opt_uname, "uname=%s"},
9e82cf6a EVH	70	{Opt_remotename, "aname=%s"},
	71	{Opt_unix, "proto=unix"},
	72	{Opt_tcp, "proto=tcp"},
	73	{Opt_fd, "proto=fd"},
	74	{Opt_tcp, "tcp"},
	75	{Opt_unix, "unix"},
	76	{Opt_fd, "fd"},
	77	{Opt_legacy, "noextend"},
	78	{Opt_nodevmap, "nodevmap"},
	79	{Opt_err, NULL}
	80	};
	81
	82	/*
	83	* Parse option string.
	84	*/
	85
	86	/**
	87	* v9fs_parse_options - parse mount options into session structure
	88	* @options: options string passed from mount
	89	* @v9ses: existing v9fs session information
	90	*
	91	*/
	92
	93	static void v9fs_parse_options(char options, struct v9fs_session_info v9ses)
	94	{
	95	char *p;
	96	substring_t args[MAX_OPT_ARGS];
	97	int option;
	98	int ret;
	99
	100	/* setup defaults */
	101	v9ses->port = V9FS_PORT;
	102	v9ses->maxdata = 9000;
	103	v9ses->proto = PROTO_TCP;
	104	v9ses->extended = 1;
	105	v9ses->afid = ~0;
	106	v9ses->debug = 0;
	107	v9ses->rfdno = ~0;
	108	v9ses->wfdno = ~0;
	109
	110	if (!options)
	111	return;
	112
	113	while ((p = strsep(&options, ",")) != NULL) {
	114	int token;
	115	if (!*p)
	116	continue;
	117	token = match_token(p, tokens, args);
67543e50	118	if (token < Opt_uname) {
9e82cf6a EVH	119	if ((ret = match_int(&args[0], &option)) < 0) {
	120	dprintk(DEBUG_ERROR,
	121	"integer field, but no integer?\n");
	122	continue;
	123	}
	124
	125	}
	126	switch (token) {
	127	case Opt_port:
	128	v9ses->port = option;
	129	break;
	130	case Opt_msize:
	131	v9ses->maxdata = option;
	132	break;
	133	case Opt_uid:
	134	v9ses->uid = option;
	135	break;
	136	case Opt_gid:
	137	v9ses->gid = option;
	138	break;
	139	case Opt_afid:
	140	v9ses->afid = option;
	141	break;
	142	case Opt_rfdno:
	143	v9ses->rfdno = option;
	144	break;
	145	case Opt_wfdno:
	146	v9ses->wfdno = option;
	147	break;
	148	case Opt_debug:
	149	v9ses->debug = option;
	150	break;
	151	case Opt_tcp:
	152	v9ses->proto = PROTO_TCP;
	153	break;
	154	case Opt_unix:
	155	v9ses->proto = PROTO_UNIX;
	156	break;
	157	case Opt_fd:
	158	v9ses->proto = PROTO_FD;
	159	break;
67543e50	160	case Opt_uname:
9e82cf6a EVH	161	match_strcpy(v9ses->name, &args[0]);
	162	break;
	163	case Opt_remotename:
	164	match_strcpy(v9ses->remotename, &args[0]);
	165	break;
	166	case Opt_legacy:
	167	v9ses->extended = 0;
	168	break;
	169	case Opt_nodevmap:
	170	v9ses->nodev = 1;
	171	break;
	172	default:
	173	continue;
	174	}
	175	}
	176	}
	177
	178	/**
	179	* v9fs_inode2v9ses - safely extract v9fs session info from super block
	180	* @inode: inode to extract information from
	181	*
	182	* Paranoid function to extract v9ses information from superblock,
	183	* if anything is missing it will report an error.
	184	*
	185	*/
	186
	187	struct v9fs_session_info v9fs_inode2v9ses(struct inode inode)
	188	{
	189	return (inode->i_sb->s_fs_info);
	190	}
	191
	192	/**
	193	* v9fs_get_idpool - allocate numeric id from pool
	194	* @p - pool to allocate from
	195	*
	196	* XXX - This seems to be an awful generic function, should it be in idr.c with
	197	* the lock included in struct idr?
	198	*/
	199
	200	int v9fs_get_idpool(struct v9fs_idpool *p)
	201	{
	202	int i = 0;
	203	int error;
	204
	205	retry:
	206	if (idr_pre_get(&p->pool, GFP_KERNEL) == 0)
	207	return 0;
	208
	209	if (down_interruptible(&p->lock) == -EINTR) {
	210	eprintk(KERN_WARNING, "Interrupted while locking\n");
	211	return -1;
	212	}
	213
3cf6429a LI	214	/* no need to store exactly p, we just need something non-null */
3cf6429a LI	215	error = idr_get_new(&p->pool, p, &i);
9e82cf6a EVH	216	up(&p->lock);
	217
	218	if (error == -EAGAIN)
	219	goto retry;
	220	else if (error)
	221	return -1;
	222
	223	return i;
	224	}
	225
	226	/**
	227	* v9fs_put_idpool - release numeric id from pool
	228	* @p - pool to allocate from
	229	*
	230	* XXX - This seems to be an awful generic function, should it be in idr.c with
	231	* the lock included in struct idr?
	232	*/
	233
	234	void v9fs_put_idpool(int id, struct v9fs_idpool *p)
	235	{
	236	if (down_interruptible(&p->lock) == -EINTR) {
	237	eprintk(KERN_WARNING, "Interrupted while locking\n");
	238	return;
	239	}
	240	idr_remove(&p->pool, id);
	241	up(&p->lock);
	242	}
	243
3cf6429a LI	244	/**
	245	* v9fs_check_idpool - check if the specified id is available
	246	* @id - id to check
	247	* @p - pool
	248	*/
	249	int v9fs_check_idpool(int id, struct v9fs_idpool *p)
	250	{
	251	return idr_find(&p->pool, id) != NULL;
	252	}
	253
9e82cf6a EVH	254	/**
	255	* v9fs_session_init - initialize session
	256	* @v9ses: session information structure
	257	* @dev_name: device being mounted
	258	* @data: options
	259	*
	260	*/
	261
	262	int
	263	v9fs_session_init(struct v9fs_session_info *v9ses,
	264	const char dev_name, char data)
	265	{
	266	struct v9fs_fcall *fcall = NULL;
	267	struct v9fs_transport *trans_proto;
	268	int n = 0;
	269	int newfid = -1;
	270	int retval = -EINVAL;
1dac06b2	271	struct v9fs_str *version;
9e82cf6a EVH	272
	273	v9ses->name = __getname();
	274	if (!v9ses->name)
	275	return -ENOMEM;
	276
	277	v9ses->remotename = __getname();
	278	if (!v9ses->remotename) {
ce44eeb6	279	__putname(v9ses->name);
9e82cf6a EVH	280	return -ENOMEM;
	281	}
	282
	283	strcpy(v9ses->name, V9FS_DEFUSER);
	284	strcpy(v9ses->remotename, V9FS_DEFANAME);
	285
	286	v9fs_parse_options(data, v9ses);
	287
	288	/* set global debug level */
	289	v9fs_debug_level = v9ses->debug;
	290
4a26c242	291	/* id pools that are session-dependent: fids and tags */
9e82cf6a EVH	292	idr_init(&v9ses->fidpool.pool);
9e82cf6a EVH	293	init_MUTEX(&v9ses->fidpool.lock);
9e82cf6a EVH	294
	295	switch (v9ses->proto) {
	296	case PROTO_TCP:
	297	trans_proto = &v9fs_trans_tcp;
	298	break;
	299	case PROTO_UNIX:
	300	trans_proto = &v9fs_trans_unix;
	301	*v9ses->remotename = 0;
	302	break;
	303	case PROTO_FD:
	304	trans_proto = &v9fs_trans_fd;
	305	*v9ses->remotename = 0;
9e82cf6a EVH	306	break;
	307	default:
	308	printk(KERN_ERR "v9fs: Bad mount protocol %d\n", v9ses->proto);
	309	retval = -ENOPROTOOPT;
	310	goto SessCleanUp;
	311	};
	312
a8e63bff LI	313	v9ses->transport = kmalloc(sizeof(*v9ses->transport), GFP_KERNEL);
	314	if (!v9ses->transport) {
	315	retval = -ENOMEM;
	316	goto SessCleanUp;
	317	}
	318
	319	memmove(v9ses->transport, trans_proto, sizeof(*v9ses->transport));
9e82cf6a EVH	320
	321	if ((retval = v9ses->transport->init(v9ses, dev_name, data)) < 0) {
	322	eprintk(KERN_ERR, "problem initializing transport\n");
	323	goto SessCleanUp;
	324	}
	325
	326	v9ses->inprogress = 0;
	327	v9ses->shutdown = 0;
	328	v9ses->session_hung = 0;
	329
3cf6429a LI	330	v9ses->mux = v9fs_mux_init(v9ses->transport, v9ses->maxdata + V9FS_IOHDRSZ,
	331	&v9ses->extended);
	332
	333	if (IS_ERR(v9ses->mux)) {
	334	retval = PTR_ERR(v9ses->mux);
	335	v9ses->mux = NULL;
9e82cf6a EVH	336	dprintk(DEBUG_ERROR, "problem initializing mux\n");
	337	goto SessCleanUp;
	338	}
	339
	340	if (v9ses->afid == ~0) {
	341	if (v9ses->extended)
	342	retval =
	343	v9fs_t_version(v9ses, v9ses->maxdata, "9P2000.u",
	344	&fcall);
	345	else
	346	retval = v9fs_t_version(v9ses, v9ses->maxdata, "9P2000",
	347	&fcall);
	348
	349	if (retval < 0) {
	350	dprintk(DEBUG_ERROR, "v9fs_t_version failed\n");
	351	goto FreeFcall;
	352	}
	353
1dac06b2 LI	354	version = &fcall->params.rversion.version;
1dac06b2 LI	355	if (version->len==8 && !memcmp(version->str, "9P2000.u", 8)) {
9e82cf6a EVH	356	dprintk(DEBUG_9P, "9P2000 UNIX extensions enabled\n");
9e82cf6a EVH	357	v9ses->extended = 1;
1dac06b2	358	} else if (version->len==6 && !memcmp(version->str, "9P2000", 6)) {
9e82cf6a EVH	359	dprintk(DEBUG_9P, "9P2000 legacy mode enabled\n");
9e82cf6a EVH	360	v9ses->extended = 0;
1dac06b2 LI	361	} else {
	362	retval = -EREMOTEIO;
	363	goto FreeFcall;
9e82cf6a EVH	364	}
	365
	366	n = fcall->params.rversion.msize;
	367	kfree(fcall);
	368
	369	if (n < v9ses->maxdata)
	370	v9ses->maxdata = n;
	371	}
	372
	373	newfid = v9fs_get_idpool(&v9ses->fidpool);
	374	if (newfid < 0) {
	375	eprintk(KERN_WARNING, "couldn't allocate FID\n");
	376	retval = -ENOMEM;
	377	goto SessCleanUp;
	378	}
	379	/* it is a little bit ugly, but we have to prevent newfid */
	380	/* being the same as afid, so if it is, get a new fid */
	381	if (v9ses->afid != ~0 && newfid == v9ses->afid) {
	382	newfid = v9fs_get_idpool(&v9ses->fidpool);
	383	if (newfid < 0) {
	384	eprintk(KERN_WARNING, "couldn't allocate FID\n");
	385	retval = -ENOMEM;
	386	goto SessCleanUp;
	387	}
	388	}
	389
	390	if ((retval =
	391	v9fs_t_attach(v9ses, v9ses->name, v9ses->remotename, newfid,
	392	v9ses->afid, NULL))
	393	< 0) {
	394	dprintk(DEBUG_ERROR, "cannot attach\n");
	395	goto SessCleanUp;
	396	}
	397
	398	if (v9ses->afid != ~0) {
46f6dac2	399	dprintk(DEBUG_ERROR, "afid not equal to ~0\n");
3cf6429a	400	if (v9fs_t_clunk(v9ses, v9ses->afid))
9e82cf6a EVH	401	dprintk(DEBUG_ERROR, "clunk failed\n");
	402	}
	403
	404	return newfid;
	405
	406	FreeFcall:
	407	kfree(fcall);
	408
	409	SessCleanUp:
	410	v9fs_session_close(v9ses);
	411	return retval;
	412	}
	413
	414	/**
	415	* v9fs_session_close - shutdown a session
	416	* @v9ses: session information structure
	417	*
	418	*/
	419
	420	void v9fs_session_close(struct v9fs_session_info *v9ses)
	421	{
3cf6429a LI	422	if (v9ses->mux) {
	423	v9fs_mux_destroy(v9ses->mux);
	424	v9ses->mux = NULL;
9e82cf6a EVH	425	}
9e82cf6a EVH	426
3cf6429a	427	if (v9ses->transport) {
9e82cf6a	428	v9ses->transport->close(v9ses->transport);
3cf6429a LI	429	kfree(v9ses->transport);
	430	v9ses->transport = NULL;
	431	}
9e82cf6a	432
ce44eeb6 DA	433	__putname(v9ses->name);
ce44eeb6 DA	434	__putname(v9ses->remotename);
9e82cf6a EVH	435	}
9e82cf6a EVH	436
322b329a EVH	437	/**
	438	* v9fs_session_cancel - mark transport as disconnected
	439	* and cancel all pending requests.
	440	*/
	441	void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
3cf6429a	442	dprintk(DEBUG_ERROR, "cancel session %p\n", v9ses);
322b329a	443	v9ses->transport->status = Disconnected;
3cf6429a	444	v9fs_mux_cancel(v9ses->mux, -EIO);
322b329a EVH	445	}
322b329a EVH	446
9e82cf6a EVH	447	extern int v9fs_error_init(void);
	448
	449	/**
	450	* v9fs_init - Initialize module
	451	*
	452	*/
	453
	454	static int __init init_v9fs(void)
	455	{
1dac06b2 LI	456	int ret;
1dac06b2 LI	457
9e82cf6a EVH	458	v9fs_error_init();
	459
	460	printk(KERN_INFO "Installing v9fs 9P2000 file system support\n");
	461
1dac06b2 LI	462	ret = v9fs_mux_global_init();
	463	if (!ret)
	464	ret = register_filesystem(&v9fs_fs_type);
	465
	466	return ret;
9e82cf6a EVH	467	}
	468
	469	/**
	470	* v9fs_init - shutdown module
	471	*
	472	*/
	473
	474	static void __exit exit_v9fs(void)
	475	{
3cf6429a	476	v9fs_mux_global_exit();
9e82cf6a EVH	477	unregister_filesystem(&v9fs_fs_type);
	478	}
	479
	480	module_init(init_v9fs)
	481	module_exit(exit_v9fs)
	482
	483	MODULE_AUTHOR("Eric Van Hensbergen <[email protected]>");
	484	MODULE_AUTHOR("Ron Minnich <[email protected]>");
	485	MODULE_LICENSE("GPL");