[net-next-2.6.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 <linux/slab.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <net/9p/transport.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "cache.h"

static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
static LIST_HEAD(v9fs_sessionlist);

/*
 * 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, Opt_cache, Opt_cachetag,
	/* Options that take no arguments */
	Opt_nodevmap,
	/* Cache options */
	Opt_cache_loose, Opt_fscache,
	/* 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, "cache=%s"},
	{Opt_cache_loose, "loose"},
	{Opt_fscache, "fscache"},
	{Opt_cachetag, "cachetag=%s"},
	{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 *opts)
{
	char *options, *tmp_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;
#ifdef CONFIG_9P_FSCACHE
	v9ses->cachetag = NULL;
#endif

	if (!opts)
		return 0;

	tmp_options = kstrdup(opts, GFP_KERNEL);
	if (!tmp_options) {
		ret = -ENOMEM;
		goto fail_option_alloc;
	}
	options = tmp_options;

	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_fscache:
			v9ses->cache = CACHE_FSCACHE;
			break;
		case Opt_cachetag:
#ifdef CONFIG_9P_FSCACHE
			v9ses->cachetag = match_strdup(&args[0]);
#endif
			break;
		case Opt_cache:
			s = match_strdup(&args[0]);
			if (!s) {
				ret = -ENOMEM;
				P9_DPRINTK(P9_DEBUG_ERROR,
				  "problem allocating copy of cache arg\n");
				goto free_and_return;
			}

			if (strcmp(s, "loose") == 0)
				v9ses->cache = CACHE_LOOSE;
			else if (strcmp(s, "fscache") == 0)
				v9ses->cache = CACHE_FSCACHE;
			else
				v9ses->cache = CACHE_NONE;
			kfree(s);
			break;

		case Opt_access:
			s = match_strdup(&args[0]);
			if (!s) {
				ret = -ENOMEM;
				P9_DPRINTK(P9_DEBUG_ERROR,
				  "problem allocating copy of access arg\n");
				goto free_and_return;
			}

			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_strtoul(s, &e, 10);
				if (*e != '\0')
					v9ses->uid = ~0;
			}
			kfree(s);
			break;

		default:
			continue;
		}
	}

free_and_return:
	kfree(tmp_options);
fail_option_alloc:
	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);
	}

	rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY);
	if (rc) {
		__putname(v9ses->aname);
		__putname(v9ses->uname);
		return ERR_PTR(rc);
	}

	spin_lock(&v9fs_sessionlist_lock);
	list_add(&v9ses->slist, &v9fs_sessionlist);
	spin_unlock(&v9fs_sessionlist_lock);

	v9ses->flags = V9FS_ACCESS_USER;
	strcpy(v9ses->uname, V9FS_DEFUSER);
	strcpy(v9ses->aname, V9FS_DEFANAME);
	v9ses->uid = ~0;
	v9ses->dfltuid = V9FS_DEFUID;
	v9ses->dfltgid = V9FS_DEFGID;

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

	v9ses->clnt = p9_client_create(dev_name, data);
	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 (p9_is_proto_dotl(v9ses->clnt))
		v9ses->flags |= V9FS_PROTO_2000L;
	else if (p9_is_proto_dotu(v9ses->clnt))
		v9ses->flags |= V9FS_PROTO_2000U;

	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;

	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
	if (!v9fs_proto_dotu(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;

#ifdef CONFIG_9P_FSCACHE
	/* register the session for caching */
	v9fs_cache_session_get_cookie(v9ses);
#endif

	return fid;

error:
	bdi_destroy(&v9ses->bdi);
	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;
	}

#ifdef CONFIG_9P_FSCACHE
	if (v9ses->fscache) {
		v9fs_cache_session_put_cookie(v9ses);
		kfree(v9ses->cachetag);
	}
#endif
	__putname(v9ses->uname);
	__putname(v9ses->aname);

	bdi_destroy(&v9ses->bdi);

	spin_lock(&v9fs_sessionlist_lock);
	list_del(&v9ses->slist);
	spin_unlock(&v9fs_sessionlist_lock);
}

/**
 * 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);
}

/**
 * v9fs_session_begin_cancel - Begin terminate of a session
 * @v9ses: session to terminate
 *
 * After this call we don't allow any request other than clunk.
 */

void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
{
	P9_DPRINTK(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
	p9_client_begin_disconnect(v9ses->clnt);
}

extern int v9fs_error_init(void);

static struct kobject *v9fs_kobj;

#ifdef CONFIG_9P_FSCACHE
/**
 * caches_show - list caches associated with a session
 *
 * Returns the size of buffer written.
 */

static ssize_t caches_show(struct kobject *kobj,
			   struct kobj_attribute *attr,
			   char *buf)
{
	ssize_t n = 0, count = 0, limit = PAGE_SIZE;
	struct v9fs_session_info *v9ses;

	spin_lock(&v9fs_sessionlist_lock);
	list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
		if (v9ses->cachetag) {
			n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
			if (n < 0) {
				count = n;
				break;
			}

			count += n;
			limit -= n;
		}
	}

	spin_unlock(&v9fs_sessionlist_lock);
	return count;
}

static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
#endif /* CONFIG_9P_FSCACHE */

static struct attribute *v9fs_attrs[] = {
#ifdef CONFIG_9P_FSCACHE
	&v9fs_attr_cache.attr,
#endif
	NULL,
};

static struct attribute_group v9fs_attr_group = {
	.attrs = v9fs_attrs,
};

/**
 * v9fs_sysfs_init - Initialize the v9fs sysfs interface
 *
 */

static int v9fs_sysfs_init(void)
{
	v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
	if (!v9fs_kobj)
		return -ENOMEM;

	if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
		kobject_put(v9fs_kobj);
		return -ENOMEM;
	}

	return 0;
}

/**
 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
 *
 */

static void v9fs_sysfs_cleanup(void)
{
	sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
	kobject_put(v9fs_kobj);
}

/**
 * init_v9fs - Initialize module
 *
 */

static int __init init_v9fs(void)
{
	int err;
	printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
	/* TODO: Setup list of registered trasnport modules */
	err = register_filesystem(&v9fs_fs_type);
	if (err < 0) {
		printk(KERN_ERR "Failed to register filesystem\n");
		return err;
	}

	err = v9fs_cache_register();
	if (err < 0) {
		printk(KERN_ERR "Failed to register v9fs for caching\n");
		goto out_fs_unreg;
	}

	err = v9fs_sysfs_init();
	if (err < 0) {
		printk(KERN_ERR "Failed to register with sysfs\n");
		goto out_sysfs_cleanup;
	}

	return 0;

out_sysfs_cleanup:
	v9fs_sysfs_cleanup();

out_fs_unreg:
	unregister_filesystem(&v9fs_fs_type);

	return err;
}

/**
 * exit_v9fs - shutdown module
 *
 */

static void __exit exit_v9fs(void)
{
	v9fs_sysfs_cleanup();
	v9fs_cache_unregister();
	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>
5a0e3ad6	32	#include <linux/slab.h>
bd238fb4	33	#include <net/9p/9p.h>
bd238fb4	34	#include <net/9p/client.h>
8b81ef58	35	#include <net/9p/transport.h>
9e82cf6a	36	#include "v9fs.h"
9e82cf6a	37	#include "v9fs_vfs.h"
60e78d2c AK	38	#include "cache.h"
	39
	40	static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
	41	static LIST_HEAD(v9fs_sessionlist);
9e82cf6a EVH	42
9e82cf6a EVH	43	/*
60e78d2c AK	44	* Option Parsing (code inspired by NFS code)
	45	* NOTE: each transport will parse its own options
	46	*/
9e82cf6a EVH	47
	48	enum {
	49	/* Options that take integer arguments */
8a0dc95f	50	Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
9e82cf6a	51	/* String options */
60e78d2c	52	Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag,
9e82cf6a	53	/* Options that take no arguments */
8a0dc95f	54	Opt_nodevmap,
e03abc0c	55	/* Cache options */
60e78d2c	56	Opt_cache_loose, Opt_fscache,
ba17674f LI	57	/* Access options */
ba17674f LI	58	Opt_access,
9e82cf6a EVH	59	/* Error token */
	60	Opt_err
	61	};
	62
a447c093	63	static const match_table_t tokens = {
9e2f6688	64	{Opt_debug, "debug=%x"},
bd32b82d LI	65	{Opt_dfltuid, "dfltuid=%u"},
bd32b82d LI	66	{Opt_dfltgid, "dfltgid=%u"},
9e82cf6a	67	{Opt_afid, "afid=%u"},
67543e50	68	{Opt_uname, "uname=%s"},
9e82cf6a	69	{Opt_remotename, "aname=%s"},
9e82cf6a	70	{Opt_nodevmap, "nodevmap"},
60e78d2c	71	{Opt_cache, "cache=%s"},
e03abc0c	72	{Opt_cache_loose, "loose"},
60e78d2c AK	73	{Opt_fscache, "fscache"},
60e78d2c AK	74	{Opt_cachetag, "cachetag=%s"},
ba17674f	75	{Opt_access, "access=%s"},
9e82cf6a EVH	76	{Opt_err, NULL}
	77	};
	78
9e82cf6a EVH	79	/**
9e82cf6a EVH	80	* v9fs_parse_options - parse mount options into session structure
9e82cf6a EVH	81	* @v9ses: existing v9fs session information
9e82cf6a EVH	82	*
ab31267d	83	* Return 0 upon success, -ERRNO upon failure.
9e82cf6a EVH	84	*/
9e82cf6a EVH	85
4b53e4b5	86	static int v9fs_parse_options(struct v9fs_session_info v9ses, char opts)
9e82cf6a	87	{
d8c8a9e3	88	char options, tmp_options;
9e82cf6a	89	substring_t args[MAX_OPT_ARGS];
a80d923e	90	char *p;
8a0dc95f	91	int option = 0;
ba17674f	92	char s, e;
ab31267d	93	int ret = 0;
9e82cf6a EVH	94
9e82cf6a EVH	95	/* setup defaults */
9e82cf6a EVH	96	v9ses->afid = ~0;
9e82cf6a EVH	97	v9ses->debug = 0;
e03abc0c	98	v9ses->cache = 0;
60e78d2c AK	99	#ifdef CONFIG_9P_FSCACHE
	100	v9ses->cachetag = NULL;
	101	#endif
9e82cf6a	102
4b53e4b5	103	if (!opts)
ab31267d	104	return 0;
9e82cf6a	105
d8c8a9e3	106	tmp_options = kstrdup(opts, GFP_KERNEL);
bf2d29c6 EVH	107	if (!tmp_options) {
bf2d29c6 EVH	108	ret = -ENOMEM;
60e78d2c	109	goto fail_option_alloc;
bf2d29c6	110	}
d8c8a9e3	111	options = tmp_options;
ab31267d	112
9e82cf6a EVH	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) {
ab31267d JM	119	int r = match_int(&args[0], &option);
ab31267d JM	120	if (r < 0) {
bd238fb4	121	P9_DPRINTK(P9_DEBUG_ERROR,
9e82cf6a	122	"integer field, but no integer?\n");
ab31267d	123	ret = r;
9e82cf6a EVH	124	continue;
9e82cf6a EVH	125	}
9e82cf6a EVH	126	}
9e82cf6a EVH	127	switch (token) {
9e2f6688 EVH	128	case Opt_debug:
9e2f6688 EVH	129	v9ses->debug = option;
10fa16e7	130	#ifdef CONFIG_NET_9P_DEBUG
9e2f6688	131	p9_debug_level = option;
10fa16e7	132	#endif
9e2f6688	133	break;
8a0dc95f	134
bd32b82d LI	135	case Opt_dfltuid:
bd32b82d LI	136	v9ses->dfltuid = option;
9e82cf6a	137	break;
bd32b82d LI	138	case Opt_dfltgid:
bd32b82d LI	139	v9ses->dfltgid = option;
9e82cf6a EVH	140	break;
	141	case Opt_afid:
	142	v9ses->afid = option;
	143	break;
67543e50	144	case Opt_uname:
b32a09db	145	match_strlcpy(v9ses->uname, &args[0], PATH_MAX);
9e82cf6a EVH	146	break;
9e82cf6a EVH	147	case Opt_remotename:
b32a09db	148	match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
9e82cf6a	149	break;
9e82cf6a EVH	150	case Opt_nodevmap:
	151	v9ses->nodev = 1;
	152	break;
e03abc0c EVH	153	case Opt_cache_loose:
	154	v9ses->cache = CACHE_LOOSE;
	155	break;
60e78d2c AK	156	case Opt_fscache:
	157	v9ses->cache = CACHE_FSCACHE;
	158	break;
	159	case Opt_cachetag:
	160	#ifdef CONFIG_9P_FSCACHE
	161	v9ses->cachetag = match_strdup(&args[0]);
	162	#endif
	163	break;
	164	case Opt_cache:
	165	s = match_strdup(&args[0]);
bf2d29c6 EVH	166	if (!s) {
	167	ret = -ENOMEM;
	168	P9_DPRINTK(P9_DEBUG_ERROR,
	169	"problem allocating copy of cache arg\n");
	170	goto free_and_return;
	171	}
60e78d2c AK	172
	173	if (strcmp(s, "loose") == 0)
	174	v9ses->cache = CACHE_LOOSE;
	175	else if (strcmp(s, "fscache") == 0)
	176	v9ses->cache = CACHE_FSCACHE;
	177	else
	178	v9ses->cache = CACHE_NONE;
	179	kfree(s);
	180	break;
ba17674f LI	181
	182	case Opt_access:
	183	s = match_strdup(&args[0]);
bf2d29c6 EVH	184	if (!s) {
	185	ret = -ENOMEM;
	186	P9_DPRINTK(P9_DEBUG_ERROR,
	187	"problem allocating copy of access arg\n");
	188	goto free_and_return;
	189	}
60e78d2c	190
ba17674f LI	191	v9ses->flags &= ~V9FS_ACCESS_MASK;
	192	if (strcmp(s, "user") == 0)
	193	v9ses->flags \|= V9FS_ACCESS_USER;
	194	else if (strcmp(s, "any") == 0)
	195	v9ses->flags \|= V9FS_ACCESS_ANY;
	196	else {
	197	v9ses->flags \|= V9FS_ACCESS_SINGLE;
f1d9e458	198	v9ses->uid = simple_strtoul(s, &e, 10);
ba17674f LI	199	if (*e != '\0')
	200	v9ses->uid = ~0;
	201	}
0a976297	202	kfree(s);
ba17674f LI	203	break;
ba17674f LI	204
9e82cf6a EVH	205	default:
	206	continue;
	207	}
	208	}
d8c8a9e3	209
bf2d29c6	210	free_and_return:
d8c8a9e3	211	kfree(tmp_options);
60e78d2c	212	fail_option_alloc:
bf2d29c6	213	return ret;
9e82cf6a EVH	214	}
9e82cf6a EVH	215
9e82cf6a EVH	216	/**
	217	* v9fs_session_init - initialize session
	218	* @v9ses: session information structure
	219	* @dev_name: device being mounted
	220	* @data: options
	221	*
	222	*/
	223
bd238fb4	224	struct p9_fid v9fs_session_init(struct v9fs_session_info v9ses,
9e82cf6a EVH	225	const char dev_name, char data)
9e82cf6a EVH	226	{
9e82cf6a	227	int retval = -EINVAL;
bd238fb4	228	struct p9_fid *fid;
ab31267d	229	int rc;
9e82cf6a	230
ba17674f LI	231	v9ses->uname = __getname();
ba17674f LI	232	if (!v9ses->uname)
bd238fb4	233	return ERR_PTR(-ENOMEM);
9e82cf6a	234
ba17674f LI	235	v9ses->aname = __getname();
	236	if (!v9ses->aname) {
	237	__putname(v9ses->uname);
bd238fb4	238	return ERR_PTR(-ENOMEM);
9e82cf6a EVH	239	}
9e82cf6a EVH	240
0ed07ddb JA	241	rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY);
	242	if (rc) {
	243	__putname(v9ses->aname);
	244	__putname(v9ses->uname);
	245	return ERR_PTR(rc);
	246	}
	247
60e78d2c AK	248	spin_lock(&v9fs_sessionlist_lock);
	249	list_add(&v9ses->slist, &v9fs_sessionlist);
	250	spin_unlock(&v9fs_sessionlist_lock);
	251
476ada04	252	v9ses->flags = V9FS_ACCESS_USER;
ba17674f LI	253	strcpy(v9ses->uname, V9FS_DEFUSER);
	254	strcpy(v9ses->aname, V9FS_DEFANAME);
	255	v9ses->uid = ~0;
bd32b82d LI	256	v9ses->dfltuid = V9FS_DEFUID;
bd32b82d LI	257	v9ses->dfltgid = V9FS_DEFGID;
ab31267d	258
4b53e4b5	259	rc = v9fs_parse_options(v9ses, data);
ab31267d JM	260	if (rc < 0) {
	261	retval = rc;
	262	goto error;
	263	}
a80d923e	264
4b53e4b5	265	v9ses->clnt = p9_client_create(dev_name, data);
bd238fb4 LI	266	if (IS_ERR(v9ses->clnt)) {
	267	retval = PTR_ERR(v9ses->clnt);
	268	v9ses->clnt = NULL;
	269	P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
	270	goto error;
9e82cf6a EVH	271	}
9e82cf6a EVH	272
476ada04 SK	273	if (p9_is_proto_dotl(v9ses->clnt))
	274	v9ses->flags \|= V9FS_PROTO_2000L;
	275	else if (p9_is_proto_dotu(v9ses->clnt))
	276	v9ses->flags \|= V9FS_PROTO_2000U;
ba17674f	277
fbedadc1	278	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
8a0dc95f	279
ba17674f	280	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
dd6102fb	281	if (!v9fs_proto_dotu(v9ses) &&
ba17674f LI	282	((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
	283
	284	v9ses->flags &= ~V9FS_ACCESS_MASK;
	285	v9ses->flags \|= V9FS_ACCESS_ANY;
	286	v9ses->uid = ~0;
	287	}
	288
	289	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
	290	v9ses->aname);
bd238fb4 LI	291	if (IS_ERR(fid)) {
	292	retval = PTR_ERR(fid);
	293	fid = NULL;
	294	P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
	295	goto error;
9e82cf6a EVH	296	}
9e82cf6a EVH	297
ba17674f LI	298	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
	299	fid->uid = v9ses->uid;
	300	else
	301	fid->uid = ~0;
	302
60e78d2c AK	303	#ifdef CONFIG_9P_FSCACHE
	304	/* register the session for caching */
	305	v9fs_cache_session_get_cookie(v9ses);
	306	#endif
	307
bd238fb4	308	return fid;
9e82cf6a	309
bd238fb4	310	error:
0ed07ddb	311	bdi_destroy(&v9ses->bdi);
bd238fb4	312	return ERR_PTR(retval);
9e82cf6a EVH	313	}
	314
	315	/**
	316	* v9fs_session_close - shutdown a session
	317	* @v9ses: session information structure
	318	*
	319	*/
	320
	321	void v9fs_session_close(struct v9fs_session_info *v9ses)
	322	{
bd238fb4 LI	323	if (v9ses->clnt) {
	324	p9_client_destroy(v9ses->clnt);
	325	v9ses->clnt = NULL;
3cf6429a	326	}
9e82cf6a	327
60e78d2c AK	328	#ifdef CONFIG_9P_FSCACHE
	329	if (v9ses->fscache) {
	330	v9fs_cache_session_put_cookie(v9ses);
	331	kfree(v9ses->cachetag);
	332	}
	333	#endif
ba17674f LI	334	__putname(v9ses->uname);
ba17674f LI	335	__putname(v9ses->aname);
60e78d2c	336
0ed07ddb JA	337	bdi_destroy(&v9ses->bdi);
0ed07ddb JA	338
60e78d2c AK	339	spin_lock(&v9fs_sessionlist_lock);
	340	list_del(&v9ses->slist);
	341	spin_unlock(&v9fs_sessionlist_lock);
9e82cf6a EVH	342	}
9e82cf6a EVH	343
322b329a	344	/**
ee443996 EVH	345	* v9fs_session_cancel - terminate a session
	346	* @v9ses: session to terminate
	347	*
	348	* mark transport as disconnected and cancel all pending requests.
322b329a	349	*/
ee443996	350
322b329a	351	void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
bd238fb4 LI	352	P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
bd238fb4 LI	353	p9_client_disconnect(v9ses->clnt);
322b329a EVH	354	}
322b329a EVH	355
6d96d3ab AK	356	/**
	357	* v9fs_session_begin_cancel - Begin terminate of a session
	358	* @v9ses: session to terminate
	359	*
	360	* After this call we don't allow any request other than clunk.
	361	*/
	362
	363	void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
	364	{
	365	P9_DPRINTK(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
	366	p9_client_begin_disconnect(v9ses->clnt);
	367	}
	368
9e82cf6a EVH	369	extern int v9fs_error_init(void);
9e82cf6a EVH	370
60e78d2c AK	371	static struct kobject *v9fs_kobj;
	372
	373	#ifdef CONFIG_9P_FSCACHE
9e82cf6a	374	/**
60e78d2c AK	375	* caches_show - list caches associated with a session
	376	*
	377	* Returns the size of buffer written.
	378	*/
	379
	380	static ssize_t caches_show(struct kobject *kobj,
	381	struct kobj_attribute *attr,
	382	char *buf)
	383	{
	384	ssize_t n = 0, count = 0, limit = PAGE_SIZE;
	385	struct v9fs_session_info *v9ses;
	386
	387	spin_lock(&v9fs_sessionlist_lock);
	388	list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
	389	if (v9ses->cachetag) {
	390	n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
	391	if (n < 0) {
	392	count = n;
	393	break;
	394	}
	395
	396	count += n;
	397	limit -= n;
	398	}
	399	}
	400
	401	spin_unlock(&v9fs_sessionlist_lock);
	402	return count;
	403	}
	404
	405	static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
	406	#endif /* CONFIG_9P_FSCACHE */
	407
	408	static struct attribute *v9fs_attrs[] = {
	409	#ifdef CONFIG_9P_FSCACHE
	410	&v9fs_attr_cache.attr,
	411	#endif
	412	NULL,
	413	};
	414
	415	static struct attribute_group v9fs_attr_group = {
	416	.attrs = v9fs_attrs,
	417	};
	418
	419	/**
	420	* v9fs_sysfs_init - Initialize the v9fs sysfs interface
	421	*
	422	*/
	423
	424	static int v9fs_sysfs_init(void)
	425	{
	426	v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
	427	if (!v9fs_kobj)
	428	return -ENOMEM;
	429
	430	if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
	431	kobject_put(v9fs_kobj);
	432	return -ENOMEM;
	433	}
	434
	435	return 0;
	436	}
	437
	438	/**
439	* v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
440	*
441	*/
442
443	static void v9fs_sysfs_cleanup(void)
444	{
445	sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
446	kobject_put(v9fs_kobj);
447	}
448
449	/**
450	* init_v9fs - Initialize module
9e82cf6a EVH	451	*
	452	*/
	453
	454	static int __init init_v9fs(void)
	455	{
60e78d2c	456	int err;
f94b3470	457	printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
a80d923e	458	/* TODO: Setup list of registered trasnport modules */
60e78d2c AK	459	err = register_filesystem(&v9fs_fs_type);
	460	if (err < 0) {
	461	printk(KERN_ERR "Failed to register filesystem\n");
	462	return err;
	463	}
	464
	465	err = v9fs_cache_register();
	466	if (err < 0) {
	467	printk(KERN_ERR "Failed to register v9fs for caching\n");
	468	goto out_fs_unreg;
	469	}
	470
	471	err = v9fs_sysfs_init();
	472	if (err < 0) {
	473	printk(KERN_ERR "Failed to register with sysfs\n");
	474	goto out_sysfs_cleanup;
	475	}
	476
	477	return 0;
	478
	479	out_sysfs_cleanup:
	480	v9fs_sysfs_cleanup();
	481
	482	out_fs_unreg:
	483	unregister_filesystem(&v9fs_fs_type);
	484
	485	return err;
9e82cf6a EVH	486	}
	487
	488	/**
60e78d2c	489	* exit_v9fs - shutdown module
9e82cf6a EVH	490	*
	491	*/
	492
	493	static void __exit exit_v9fs(void)
	494	{
60e78d2c AK	495	v9fs_sysfs_cleanup();
60e78d2c AK	496	v9fs_cache_unregister();
9e82cf6a EVH	497	unregister_filesystem(&v9fs_fs_type);
	498	}
	499
	500	module_init(init_v9fs)
	501	module_exit(exit_v9fs)
	502
bd238fb4	503	MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
9e82cf6a EVH	504	MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
	505	MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
	506	MODULE_LICENSE("GPL");