[linux-block.git] / fs / 9p / v9fs.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/client.h>
#include <net/9p/transport.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 const 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
 * @v9ses: existing v9fs session information
 *
 * Return 0 upon success, -ERRNO upon failure.
 */

static int 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 = 0;

	/* setup defaults */
	v9ses->afid = ~0;
	v9ses->debug = 0;
	v9ses->cache = 0;

	if (!v9ses->options)
		return 0;

	options = kstrdup(v9ses->options, GFP_KERNEL);
	if (!options) {
		P9_DPRINTK(P9_DEBUG_ERROR,
			   "failed to allocate copy of option string\n");
		return -ENOMEM;
	}

	while ((p = strsep(&options, ",")) != NULL) {
		int token;
		if (!*p)
			continue;
		token = match_token(p, tokens, args);
		if (token < Opt_uname) {
			int r = match_int(&args[0], &option);
			if (r < 0) {
				P9_DPRINTK(P9_DEBUG_ERROR,
					"integer field, but no integer?\n");
				ret = r;
				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_strlcpy(v9ses->uname, &args[0], PATH_MAX);
			break;
		case Opt_remotename:
			match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
			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]);
			if (!s) {
				P9_DPRINTK(P9_DEBUG_ERROR,
					   "failed to allocate copy"
					   " of option argument\n");
				ret = -ENOMEM;
				break;
			}
			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);
	return ret;
}

/**
 * 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;
	int rc;

	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;
	if (data) {
		v9ses->options = kstrdup(data, GFP_KERNEL);
		if (!v9ses->options) {
			P9_DPRINTK(P9_DEBUG_ERROR,
			   "failed to allocate copy of option string\n");
			retval = -ENOMEM;
			goto error;
		}
	}

	rc = v9fs_parse_options(v9ses);
	if (rc < 0) {
		retval = rc;
		goto error;
	}

	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 - P9_IOHDRSZ;

	/* 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:
	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 - 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_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");
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	*
8a0dc95f	6	* Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
9e82cf6a EVH	7	* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
	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	32	#include <net/9p/9p.h>
bd238fb4	33	#include <net/9p/client.h>
8b81ef58	34	#include <net/9p/transport.h>
9e82cf6a	35	#include "v9fs.h"
9e82cf6a	36	#include "v9fs_vfs.h"
9e82cf6a EVH	37
	38	/*
	39	* Option Parsing (code inspired by NFS code)
a80d923e	40	* NOTE: each transport will parse its own options
9e82cf6a EVH	41	*/
	42
	43	enum {
	44	/* Options that take integer arguments */
8a0dc95f	45	Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
9e82cf6a	46	/* String options */
a80d923e	47	Opt_uname, Opt_remotename, Opt_trans,
9e82cf6a	48	/* Options that take no arguments */
8a0dc95f	49	Opt_nodevmap,
e03abc0c EVH	50	/* Cache options */
e03abc0c EVH	51	Opt_cache_loose,
ba17674f LI	52	/* Access options */
ba17674f LI	53	Opt_access,
9e82cf6a EVH	54	/* Error token */
	55	Opt_err
	56	};
	57
a447c093	58	static const match_table_t tokens = {
9e2f6688	59	{Opt_debug, "debug=%x"},
bd32b82d LI	60	{Opt_dfltuid, "dfltuid=%u"},
bd32b82d LI	61	{Opt_dfltgid, "dfltgid=%u"},
9e82cf6a	62	{Opt_afid, "afid=%u"},
67543e50	63	{Opt_uname, "uname=%s"},
9e82cf6a	64	{Opt_remotename, "aname=%s"},
9e82cf6a	65	{Opt_nodevmap, "nodevmap"},
e03abc0c EVH	66	{Opt_cache_loose, "cache=loose"},
e03abc0c EVH	67	{Opt_cache_loose, "loose"},
ba17674f	68	{Opt_access, "access=%s"},
9e82cf6a EVH	69	{Opt_err, NULL}
	70	};
	71
9e82cf6a EVH	72	/**
9e82cf6a EVH	73	* v9fs_parse_options - parse mount options into session structure
9e82cf6a EVH	74	* @v9ses: existing v9fs session information
9e82cf6a EVH	75	*
ab31267d	76	* Return 0 upon success, -ERRNO upon failure.
9e82cf6a EVH	77	*/
9e82cf6a EVH	78
ab31267d	79	static int v9fs_parse_options(struct v9fs_session_info *v9ses)
9e82cf6a	80	{
8999e04f	81	char *options;
9e82cf6a	82	substring_t args[MAX_OPT_ARGS];
a80d923e	83	char *p;
8a0dc95f	84	int option = 0;
ba17674f	85	char s, e;
ab31267d	86	int ret = 0;
9e82cf6a EVH	87
9e82cf6a EVH	88	/* setup defaults */
9e82cf6a EVH	89	v9ses->afid = ~0;
9e82cf6a EVH	90	v9ses->debug = 0;
e03abc0c	91	v9ses->cache = 0;
9e82cf6a	92
8999e04f	93	if (!v9ses->options)
ab31267d	94	return 0;
9e82cf6a	95
8999e04f	96	options = kstrdup(v9ses->options, GFP_KERNEL);
ab31267d JM	97	if (!options) {
	98	P9_DPRINTK(P9_DEBUG_ERROR,
	99	"failed to allocate copy of option string\n");
	100	return -ENOMEM;
	101	}
	102
9e82cf6a EVH	103	while ((p = strsep(&options, ",")) != NULL) {
	104	int token;
	105	if (!*p)
	106	continue;
	107	token = match_token(p, tokens, args);
67543e50	108	if (token < Opt_uname) {
ab31267d JM	109	int r = match_int(&args[0], &option);
ab31267d JM	110	if (r < 0) {
bd238fb4	111	P9_DPRINTK(P9_DEBUG_ERROR,
9e82cf6a	112	"integer field, but no integer?\n");
ab31267d	113	ret = r;
9e82cf6a EVH	114	continue;
9e82cf6a EVH	115	}
9e82cf6a EVH	116	}
9e82cf6a EVH	117	switch (token) {
9e2f6688 EVH	118	case Opt_debug:
9e2f6688 EVH	119	v9ses->debug = option;
10fa16e7	120	#ifdef CONFIG_NET_9P_DEBUG
9e2f6688	121	p9_debug_level = option;
10fa16e7	122	#endif
9e2f6688	123	break;
8a0dc95f	124
bd32b82d LI	125	case Opt_dfltuid:
bd32b82d LI	126	v9ses->dfltuid = option;
9e82cf6a	127	break;
bd32b82d LI	128	case Opt_dfltgid:
bd32b82d LI	129	v9ses->dfltgid = option;
9e82cf6a EVH	130	break;
	131	case Opt_afid:
	132	v9ses->afid = option;
	133	break;
67543e50	134	case Opt_uname:
b32a09db	135	match_strlcpy(v9ses->uname, &args[0], PATH_MAX);
9e82cf6a EVH	136	break;
9e82cf6a EVH	137	case Opt_remotename:
b32a09db	138	match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
9e82cf6a	139	break;
9e82cf6a EVH	140	case Opt_nodevmap:
	141	v9ses->nodev = 1;
	142	break;
e03abc0c EVH	143	case Opt_cache_loose:
	144	v9ses->cache = CACHE_LOOSE;
	145	break;
ba17674f LI	146
	147	case Opt_access:
	148	s = match_strdup(&args[0]);
ab31267d JM	149	if (!s) {
	150	P9_DPRINTK(P9_DEBUG_ERROR,
	151	"failed to allocate copy"
	152	" of option argument\n");
	153	ret = -ENOMEM;
	154	break;
	155	}
ba17674f LI	156	v9ses->flags &= ~V9FS_ACCESS_MASK;
	157	if (strcmp(s, "user") == 0)
	158	v9ses->flags \|= V9FS_ACCESS_USER;
	159	else if (strcmp(s, "any") == 0)
	160	v9ses->flags \|= V9FS_ACCESS_ANY;
	161	else {
	162	v9ses->flags \|= V9FS_ACCESS_SINGLE;
	163	v9ses->uid = simple_strtol(s, &e, 10);
	164	if (*e != '\0')
	165	v9ses->uid = ~0;
	166	}
0a976297	167	kfree(s);
ba17674f LI	168	break;
ba17674f LI	169
9e82cf6a EVH	170	default:
	171	continue;
	172	}
	173	}
8999e04f	174	kfree(options);
ab31267d	175	return ret;
9e82cf6a EVH	176	}
9e82cf6a EVH	177
9e82cf6a EVH	178	/**
	179	* v9fs_session_init - initialize session
	180	* @v9ses: session information structure
	181	* @dev_name: device being mounted
	182	* @data: options
	183	*
	184	*/
	185
bd238fb4	186	struct p9_fid v9fs_session_init(struct v9fs_session_info v9ses,
9e82cf6a EVH	187	const char dev_name, char data)
9e82cf6a EVH	188	{
9e82cf6a	189	int retval = -EINVAL;
bd238fb4	190	struct p9_fid *fid;
ab31267d	191	int rc;
9e82cf6a	192
ba17674f LI	193	v9ses->uname = __getname();
ba17674f LI	194	if (!v9ses->uname)
bd238fb4	195	return ERR_PTR(-ENOMEM);
9e82cf6a	196
ba17674f LI	197	v9ses->aname = __getname();
	198	if (!v9ses->aname) {
	199	__putname(v9ses->uname);
bd238fb4	200	return ERR_PTR(-ENOMEM);
9e82cf6a EVH	201	}
9e82cf6a EVH	202
ba17674f LI	203	v9ses->flags = V9FS_EXTENDED \| V9FS_ACCESS_USER;
	204	strcpy(v9ses->uname, V9FS_DEFUSER);
	205	strcpy(v9ses->aname, V9FS_DEFANAME);
	206	v9ses->uid = ~0;
bd32b82d LI	207	v9ses->dfltuid = V9FS_DEFUID;
bd32b82d LI	208	v9ses->dfltgid = V9FS_DEFGID;
887b3ece EVH	209	if (data) {
	210	v9ses->options = kstrdup(data, GFP_KERNEL);
	211	if (!v9ses->options) {
	212	P9_DPRINTK(P9_DEBUG_ERROR,
ab31267d	213	"failed to allocate copy of option string\n");
887b3ece EVH	214	retval = -ENOMEM;
	215	goto error;
	216	}
ab31267d JM	217	}
	218
	219	rc = v9fs_parse_options(v9ses);
	220	if (rc < 0) {
	221	retval = rc;
	222	goto error;
	223	}
a80d923e	224
8a0dc95f	225	v9ses->clnt = p9_client_create(dev_name, v9ses->options);
9e82cf6a	226
bd238fb4 LI	227	if (IS_ERR(v9ses->clnt)) {
	228	retval = PTR_ERR(v9ses->clnt);
	229	v9ses->clnt = NULL;
	230	P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
	231	goto error;
9e82cf6a EVH	232	}
9e82cf6a EVH	233
ba17674f LI	234	if (!v9ses->clnt->dotu)
	235	v9ses->flags &= ~V9FS_EXTENDED;
	236
fbedadc1	237	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
8a0dc95f	238
ba17674f LI	239	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
	240	if (!v9fs_extended(v9ses) &&
	241	((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
	242
	243	v9ses->flags &= ~V9FS_ACCESS_MASK;
	244	v9ses->flags \|= V9FS_ACCESS_ANY;
	245	v9ses->uid = ~0;
	246	}
	247
	248	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
	249	v9ses->aname);
bd238fb4 LI	250	if (IS_ERR(fid)) {
	251	retval = PTR_ERR(fid);
	252	fid = NULL;
	253	P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
	254	goto error;
9e82cf6a EVH	255	}
9e82cf6a EVH	256
ba17674f LI	257	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
	258	fid->uid = v9ses->uid;
	259	else
	260	fid->uid = ~0;
	261
bd238fb4	262	return fid;
9e82cf6a	263
bd238fb4	264	error:
bd238fb4	265	return ERR_PTR(retval);
9e82cf6a EVH	266	}
	267
	268	/**
	269	* v9fs_session_close - shutdown a session
	270	* @v9ses: session information structure
	271	*
	272	*/
	273
	274	void v9fs_session_close(struct v9fs_session_info *v9ses)
	275	{
bd238fb4 LI	276	if (v9ses->clnt) {
	277	p9_client_destroy(v9ses->clnt);
	278	v9ses->clnt = NULL;
3cf6429a	279	}
9e82cf6a	280
ba17674f LI	281	__putname(v9ses->uname);
ba17674f LI	282	__putname(v9ses->aname);
a80d923e	283	kfree(v9ses->options);
9e82cf6a EVH	284	}
9e82cf6a EVH	285
322b329a	286	/**
ee443996 EVH	287	* v9fs_session_cancel - terminate a session
	288	* @v9ses: session to terminate
	289	*
	290	* mark transport as disconnected and cancel all pending requests.
322b329a	291	*/
ee443996	292
322b329a	293	void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
bd238fb4 LI	294	P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
bd238fb4 LI	295	p9_client_disconnect(v9ses->clnt);
322b329a EVH	296	}
322b329a EVH	297
9e82cf6a EVH	298	extern int v9fs_error_init(void);
	299
	300	/**
	301	* v9fs_init - Initialize module
	302	*
	303	*/
	304
	305	static int __init init_v9fs(void)
	306	{
f94b3470	307	printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
a80d923e	308	/* TODO: Setup list of registered trasnport modules */
bd238fb4	309	return register_filesystem(&v9fs_fs_type);
9e82cf6a EVH	310	}
	311
	312	/**
	313	* v9fs_init - shutdown module
	314	*
	315	*/
	316
	317	static void __exit exit_v9fs(void)
	318	{
	319	unregister_filesystem(&v9fs_fs_type);
	320	}
	321
	322	module_init(init_v9fs)
	323	module_exit(exit_v9fs)
	324
bd238fb4	325	MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
9e82cf6a EVH	326	MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
	327	MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
	328	MODULE_LICENSE("GPL");