[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/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/conn.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"

/*
 * Dynamic Transport Registration Routines
 *
 */

static LIST_HEAD(v9fs_trans_list);
static struct p9_trans_module *v9fs_default_trans;

/**
 * v9fs_register_trans - register a new transport with 9p
 * @m - structure describing the transport module and entry points
 *
 */
void v9fs_register_trans(struct p9_trans_module *m)
{
	list_add_tail(&m->list, &v9fs_trans_list);
	if (m->def)
		v9fs_default_trans = m;
}
EXPORT_SYMBOL(v9fs_register_trans);

/**
 * v9fs_match_trans - match transport versus registered transports
 * @arg: string identifying transport
 *
 */
static struct p9_trans_module *v9fs_match_trans(const substring_t *name)
{
	struct list_head *p;
	struct p9_trans_module *t = NULL;

	list_for_each(p, &v9fs_trans_list) {
		t = list_entry(p, struct p9_trans_module, list);
		if (strncmp(t->name, name->from, name->to-name->from) == 0) {
			P9_DPRINTK(P9_DEBUG_TRANS, "trans=%s\n", t->name);
			break;
		}
	}
	return t;
}

/*
  * Option Parsing (code inspired by NFS code)
  *  NOTE: each transport will parse its own options
  */

enum {
	/* Options that take integer arguments */
	Opt_debug, Opt_msize, Opt_uid, Opt_gid, Opt_afid,
	/* String options */
	Opt_uname, Opt_remotename, Opt_trans,
	/* Options that take no arguments */
	Opt_legacy, Opt_nodevmap,
	/* Cache options */
	Opt_cache_loose,
	/* Error token */
	Opt_err
};

static match_table_t tokens = {
	{Opt_debug, "debug=%x"},
	{Opt_msize, "msize=%u"},
	{Opt_uid, "uid=%u"},
	{Opt_gid, "gid=%u"},
	{Opt_afid, "afid=%u"},
	{Opt_uname, "uname=%s"},
	{Opt_remotename, "aname=%s"},
	{Opt_trans, "trans=%s"},
	{Opt_legacy, "noextend"},
	{Opt_nodevmap, "nodevmap"},
	{Opt_cache_loose, "cache=loose"},
	{Opt_cache_loose, "loose"},
	{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 = v9ses->options;
	substring_t args[MAX_OPT_ARGS];
	char *p;
	int option;
	int ret;

	/* setup defaults */
	v9ses->maxdata = 8192;
	v9ses->flags = V9FS_EXTENDED;
	v9ses->afid = ~0;
	v9ses->debug = 0;
	v9ses->cache = 0;
	v9ses->trans = v9fs_default_trans;

	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) {
				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_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_trans:
			v9ses->trans = v9fs_match_trans(&args[0]);
			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->flags &= ~V9FS_EXTENDED;
			break;
		case Opt_nodevmap:
			v9ses->nodev = 1;
			break;
		case Opt_cache_loose:
			v9ses->cache = CACHE_LOOSE;
			break;
		default:
			continue;
		}
	}
}

/**
 * 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_trans *trans = NULL;
	struct p9_fid *fid;

	v9ses->name = __getname();
	if (!v9ses->name)
		return ERR_PTR(-ENOMEM);

	v9ses->remotename = __getname();
	if (!v9ses->remotename) {
		__putname(v9ses->name);
		return ERR_PTR(-ENOMEM);
	}

	strcpy(v9ses->name, V9FS_DEFUSER);
	strcpy(v9ses->remotename, V9FS_DEFANAME);

	v9ses->options = kstrdup(data, GFP_KERNEL);
	v9fs_parse_options(v9ses);

	if ((v9ses->trans == NULL) && !list_empty(&v9fs_trans_list))
		v9ses->trans = list_first_entry(&v9fs_trans_list,
		 struct p9_trans_module, list);

	if (v9ses->trans == NULL) {
		retval = -EPROTONOSUPPORT;
		P9_DPRINTK(P9_DEBUG_ERROR,
				"No transport defined or default transport\n");
		goto error;
	}

	trans = v9ses->trans->create(dev_name, v9ses->options);
	if (IS_ERR(trans)) {
		retval = PTR_ERR(trans);
		trans = NULL;
		goto error;
	}
	if ((v9ses->maxdata+P9_IOHDRSZ) > v9ses->trans->maxsize)
		v9ses->maxdata = v9ses->trans->maxsize-P9_IOHDRSZ;

	v9ses->clnt = p9_client_create(trans, v9ses->maxdata+P9_IOHDRSZ,
		v9fs_extended(v9ses));

	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;
	}

	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->name,
							v9ses->remotename);
	if (IS_ERR(fid)) {
		retval = PTR_ERR(fid);
		fid = NULL;
		P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
		goto error;
	}

	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->name);
	__putname(v9ses->remotename);
	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 <[email protected]>");
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
9e82cf6a EVH	26	#include <linux/module.h>
	27	#include <linux/errno.h>
	28	#include <linux/fs.h>
914e2637	29	#include <linux/sched.h>
9e82cf6a EVH	30	#include <linux/parser.h>
9e82cf6a EVH	31	#include <linux/idr.h>
bd238fb4 LI	32	#include <net/9p/9p.h>
	33	#include <net/9p/transport.h>
	34	#include <net/9p/conn.h>
	35	#include <net/9p/client.h>
9e82cf6a	36	#include "v9fs.h"
9e82cf6a	37	#include "v9fs_vfs.h"
9e82cf6a	38
a80d923e EVH	39	/*
	40	* Dynamic Transport Registration Routines
	41	*
	42	*/
	43
	44	static LIST_HEAD(v9fs_trans_list);
	45	static struct p9_trans_module *v9fs_default_trans;
	46
	47	/**
	48	* v9fs_register_trans - register a new transport with 9p
	49	* @m - structure describing the transport module and entry points
	50	*
	51	*/
	52	void v9fs_register_trans(struct p9_trans_module *m)
	53	{
	54	list_add_tail(&m->list, &v9fs_trans_list);
	55	if (m->def)
	56	v9fs_default_trans = m;
	57	}
	58	EXPORT_SYMBOL(v9fs_register_trans);
	59
	60	/**
	61	* v9fs_match_trans - match transport versus registered transports
	62	* @arg: string identifying transport
	63	*
	64	*/
	65	static struct p9_trans_module v9fs_match_trans(const substring_t name)
	66	{
	67	struct list_head *p;
	68	struct p9_trans_module *t = NULL;
	69
	70	list_for_each(p, &v9fs_trans_list) {
	71	t = list_entry(p, struct p9_trans_module, list);
	72	if (strncmp(t->name, name->from, name->to-name->from) == 0) {
	73	P9_DPRINTK(P9_DEBUG_TRANS, "trans=%s\n", t->name);
	74	break;
	75	}
	76	}
	77	return t;
	78	}
	79
9e82cf6a EVH	80	/*
9e82cf6a EVH	81	* Option Parsing (code inspired by NFS code)
a80d923e	82	* NOTE: each transport will parse its own options
9e82cf6a EVH	83	*/
	84
	85	enum {
	86	/* Options that take integer arguments */
a80d923e	87	Opt_debug, Opt_msize, Opt_uid, Opt_gid, Opt_afid,
9e82cf6a	88	/* String options */
a80d923e	89	Opt_uname, Opt_remotename, Opt_trans,
9e82cf6a	90	/* Options that take no arguments */
a80d923e	91	Opt_legacy, Opt_nodevmap,
e03abc0c EVH	92	/* Cache options */
e03abc0c EVH	93	Opt_cache_loose,
9e82cf6a EVH	94	/* Error token */
	95	Opt_err
	96	};
	97
	98	static match_table_t tokens = {
9e2f6688	99	{Opt_debug, "debug=%x"},
9e82cf6a EVH	100	{Opt_msize, "msize=%u"},
	101	{Opt_uid, "uid=%u"},
	102	{Opt_gid, "gid=%u"},
	103	{Opt_afid, "afid=%u"},
67543e50	104	{Opt_uname, "uname=%s"},
9e82cf6a	105	{Opt_remotename, "aname=%s"},
a80d923e	106	{Opt_trans, "trans=%s"},
9e82cf6a EVH	107	{Opt_legacy, "noextend"},
9e82cf6a EVH	108	{Opt_nodevmap, "nodevmap"},
e03abc0c EVH	109	{Opt_cache_loose, "cache=loose"},
e03abc0c EVH	110	{Opt_cache_loose, "loose"},
9e82cf6a EVH	111	{Opt_err, NULL}
	112	};
	113
9e82cf6a EVH	114	/**
	115	* v9fs_parse_options - parse mount options into session structure
	116	* @options: options string passed from mount
	117	* @v9ses: existing v9fs session information
	118	*
	119	*/
	120
a80d923e	121	static void v9fs_parse_options(struct v9fs_session_info *v9ses)
9e82cf6a	122	{
a80d923e	123	char *options = v9ses->options;
9e82cf6a	124	substring_t args[MAX_OPT_ARGS];
a80d923e	125	char *p;
9e82cf6a EVH	126	int option;
	127	int ret;
	128
	129	/* setup defaults */
a80d923e	130	v9ses->maxdata = 8192;
2405669b	131	v9ses->flags = V9FS_EXTENDED;
9e82cf6a EVH	132	v9ses->afid = ~0;
9e82cf6a EVH	133	v9ses->debug = 0;
e03abc0c	134	v9ses->cache = 0;
a80d923e	135	v9ses->trans = v9fs_default_trans;
9e82cf6a EVH	136
	137	if (!options)
	138	return;
	139
	140	while ((p = strsep(&options, ",")) != NULL) {
	141	int token;
	142	if (!*p)
	143	continue;
	144	token = match_token(p, tokens, args);
67543e50	145	if (token < Opt_uname) {
9e82cf6a	146	if ((ret = match_int(&args[0], &option)) < 0) {
bd238fb4	147	P9_DPRINTK(P9_DEBUG_ERROR,
9e82cf6a EVH	148	"integer field, but no integer?\n");
	149	continue;
	150	}
9e82cf6a EVH	151	}
9e82cf6a EVH	152	switch (token) {
9e2f6688 EVH	153	case Opt_debug:
9e2f6688 EVH	154	v9ses->debug = option;
10fa16e7	155	#ifdef CONFIG_NET_9P_DEBUG
9e2f6688	156	p9_debug_level = option;
10fa16e7	157	#endif
9e2f6688	158	break;
9e82cf6a EVH	159	case Opt_msize:
	160	v9ses->maxdata = option;
	161	break;
	162	case Opt_uid:
	163	v9ses->uid = option;
	164	break;
	165	case Opt_gid:
	166	v9ses->gid = option;
	167	break;
	168	case Opt_afid:
	169	v9ses->afid = option;
	170	break;
a80d923e EVH	171	case Opt_trans:
a80d923e EVH	172	v9ses->trans = v9fs_match_trans(&args[0]);
9e82cf6a	173	break;
67543e50	174	case Opt_uname:
9e82cf6a EVH	175	match_strcpy(v9ses->name, &args[0]);
	176	break;
	177	case Opt_remotename:
	178	match_strcpy(v9ses->remotename, &args[0]);
	179	break;
	180	case Opt_legacy:
2405669b	181	v9ses->flags &= ~V9FS_EXTENDED;
9e82cf6a EVH	182	break;
	183	case Opt_nodevmap:
	184	v9ses->nodev = 1;
	185	break;
e03abc0c EVH	186	case Opt_cache_loose:
	187	v9ses->cache = CACHE_LOOSE;
	188	break;
9e82cf6a EVH	189	default:
	190	continue;
	191	}
	192	}
	193	}
	194
9e82cf6a EVH	195	/**
	196	* v9fs_session_init - initialize session
	197	* @v9ses: session information structure
	198	* @dev_name: device being mounted
	199	* @data: options
	200	*
	201	*/
	202
bd238fb4	203	struct p9_fid v9fs_session_init(struct v9fs_session_info v9ses,
9e82cf6a EVH	204	const char dev_name, char data)
9e82cf6a EVH	205	{
9e82cf6a	206	int retval = -EINVAL;
a80d923e	207	struct p9_trans *trans = NULL;
bd238fb4	208	struct p9_fid *fid;
9e82cf6a EVH	209
	210	v9ses->name = __getname();
	211	if (!v9ses->name)
bd238fb4	212	return ERR_PTR(-ENOMEM);
9e82cf6a EVH	213
	214	v9ses->remotename = __getname();
	215	if (!v9ses->remotename) {
ce44eeb6	216	__putname(v9ses->name);
bd238fb4	217	return ERR_PTR(-ENOMEM);
9e82cf6a EVH	218	}
	219
	220	strcpy(v9ses->name, V9FS_DEFUSER);
	221	strcpy(v9ses->remotename, V9FS_DEFANAME);
	222
a80d923e EVH	223	v9ses->options = kstrdup(data, GFP_KERNEL);
	224	v9fs_parse_options(v9ses);
	225
	226	if ((v9ses->trans == NULL) && !list_empty(&v9fs_trans_list))
	227	v9ses->trans = list_first_entry(&v9fs_trans_list,
	228	struct p9_trans_module, list);
	229
	230	if (v9ses->trans == NULL) {
	231	retval = -EPROTONOSUPPORT;
	232	P9_DPRINTK(P9_DEBUG_ERROR,
	233	"No transport defined or default transport\n");
bd238fb4	234	goto error;
a80d923e	235	}
9e82cf6a	236
a80d923e	237	trans = v9ses->trans->create(dev_name, v9ses->options);
bd238fb4 LI	238	if (IS_ERR(trans)) {
	239	retval = PTR_ERR(trans);
	240	trans = NULL;
	241	goto error;
a8e63bff	242	}
a80d923e EVH	243	if ((v9ses->maxdata+P9_IOHDRSZ) > v9ses->trans->maxsize)
a80d923e EVH	244	v9ses->maxdata = v9ses->trans->maxsize-P9_IOHDRSZ;
a8e63bff	245
a80d923e	246	v9ses->clnt = p9_client_create(trans, v9ses->maxdata+P9_IOHDRSZ,
2405669b	247	v9fs_extended(v9ses));
9e82cf6a	248
bd238fb4 LI	249	if (IS_ERR(v9ses->clnt)) {
	250	retval = PTR_ERR(v9ses->clnt);
	251	v9ses->clnt = NULL;
	252	P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
	253	goto error;
9e82cf6a EVH	254	}
9e82cf6a EVH	255
bd238fb4 LI	256	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->name,
	257	v9ses->remotename);
	258	if (IS_ERR(fid)) {
	259	retval = PTR_ERR(fid);
	260	fid = NULL;
	261	P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
	262	goto error;
9e82cf6a EVH	263	}
9e82cf6a EVH	264
bd238fb4	265	return fid;
9e82cf6a	266
bd238fb4	267	error:
9e82cf6a	268	v9fs_session_close(v9ses);
bd238fb4	269	return ERR_PTR(retval);
9e82cf6a EVH	270	}
	271
	272	/**
	273	* v9fs_session_close - shutdown a session
	274	* @v9ses: session information structure
	275	*
	276	*/
	277
	278	void v9fs_session_close(struct v9fs_session_info *v9ses)
	279	{
bd238fb4 LI	280	if (v9ses->clnt) {
	281	p9_client_destroy(v9ses->clnt);
	282	v9ses->clnt = NULL;
3cf6429a	283	}
9e82cf6a	284
ce44eeb6 DA	285	__putname(v9ses->name);
ce44eeb6 DA	286	__putname(v9ses->remotename);
a80d923e	287	kfree(v9ses->options);
9e82cf6a EVH	288	}
9e82cf6a EVH	289
322b329a EVH	290	/**
	291	* v9fs_session_cancel - mark transport as disconnected
	292	* and cancel all pending requests.
	293	*/
	294	void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
bd238fb4 LI	295	P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
bd238fb4 LI	296	p9_client_disconnect(v9ses->clnt);
322b329a EVH	297	}
322b329a EVH	298
9e82cf6a EVH	299	extern int v9fs_error_init(void);
	300
	301	/**
	302	* v9fs_init - Initialize module
	303	*
	304	*/
	305
	306	static int __init init_v9fs(void)
	307	{
f94b3470	308	printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
a80d923e	309	/* TODO: Setup list of registered trasnport modules */
bd238fb4	310	return register_filesystem(&v9fs_fs_type);
9e82cf6a EVH	311	}
	312
	313	/**
	314	* v9fs_init - shutdown module
	315	*
	316	*/
	317
	318	static void __exit exit_v9fs(void)
	319	{
	320	unregister_filesystem(&v9fs_fs_type);
	321	}
	322
	323	module_init(init_v9fs)
	324	module_exit(exit_v9fs)
	325
bd238fb4	326	MODULE_AUTHOR("Latchesar Ionkov <[email protected]>");
9e82cf6a EVH	327	MODULE_AUTHOR("Eric Van Hensbergen <[email protected]>");
	328	MODULE_AUTHOR("Ron Minnich <[email protected]>");
	329	MODULE_LICENSE("GPL");