[linux-block.git] / fs / afs / super.c

/* AFS superblock handling
 *
 * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
 *
 * This software may be freely redistributed under the terms of the
 * GNU General Public License.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Authors: David Howells <dhowells@redhat.com>
 *          David Woodhouse <dwmw2@infradead.org>
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/parser.h>
#include <linux/statfs.h>
#include <linux/sched.h>
#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include "internal.h"

#define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */

static void afs_i_init_once(void *foo);
static struct dentry *afs_mount(struct file_system_type *fs_type,
		      int flags, const char *dev_name, void *data);
static void afs_kill_super(struct super_block *sb);
static struct inode *afs_alloc_inode(struct super_block *sb);
static void afs_destroy_inode(struct inode *inode);
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);

struct file_system_type afs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "afs",
	.mount		= afs_mount,
	.kill_sb	= afs_kill_super,
	.fs_flags	= 0,
};

static const struct super_operations afs_super_ops = {
	.statfs		= afs_statfs,
	.alloc_inode	= afs_alloc_inode,
	.drop_inode	= afs_drop_inode,
	.destroy_inode	= afs_destroy_inode,
	.evict_inode	= afs_evict_inode,
	.show_options	= generic_show_options,
};

static struct kmem_cache *afs_inode_cachep;
static atomic_t afs_count_active_inodes;

enum {
	afs_no_opt,
	afs_opt_cell,
	afs_opt_rwpath,
	afs_opt_vol,
	afs_opt_autocell,
};

static const match_table_t afs_options_list = {
	{ afs_opt_cell,		"cell=%s"	},
	{ afs_opt_rwpath,	"rwpath"	},
	{ afs_opt_vol,		"vol=%s"	},
	{ afs_opt_autocell,	"autocell"	},
	{ afs_no_opt,		NULL		},
};

/*
 * initialise the filesystem
 */
int __init afs_fs_init(void)
{
	int ret;

	_enter("");

	/* create ourselves an inode cache */
	atomic_set(&afs_count_active_inodes, 0);

	ret = -ENOMEM;
	afs_inode_cachep = kmem_cache_create("afs_inode_cache",
					     sizeof(struct afs_vnode),
					     0,
					     SLAB_HWCACHE_ALIGN,
					     afs_i_init_once);
	if (!afs_inode_cachep) {
		printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
		return ret;
	}

	/* now export our filesystem to lesser mortals */
	ret = register_filesystem(&afs_fs_type);
	if (ret < 0) {
		kmem_cache_destroy(afs_inode_cachep);
		_leave(" = %d", ret);
		return ret;
	}

	_leave(" = 0");
	return 0;
}

/*
 * clean up the filesystem
 */
void __exit afs_fs_exit(void)
{
	_enter("");

	afs_mntpt_kill_timer();
	unregister_filesystem(&afs_fs_type);

	if (atomic_read(&afs_count_active_inodes) != 0) {
		printk("kAFS: %d active inode objects still present\n",
		       atomic_read(&afs_count_active_inodes));
		BUG();
	}

	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
	kmem_cache_destroy(afs_inode_cachep);
	_leave("");
}

/*
 * parse the mount options
 * - this function has been shamelessly adapted from the ext3 fs which
 *   shamelessly adapted it from the msdos fs
 */
static int afs_parse_options(struct afs_mount_params *params,
			     char *options, const char **devname)
{
	struct afs_cell *cell;
	substring_t args[MAX_OPT_ARGS];
	char *p;
	int token;

	_enter("%s", options);

	options[PAGE_SIZE - 1] = 0;

	while ((p = strsep(&options, ","))) {
		if (!*p)
			continue;

		token = match_token(p, afs_options_list, args);
		switch (token) {
		case afs_opt_cell:
			cell = afs_cell_lookup(args[0].from,
					       args[0].to - args[0].from,
					       false);
			if (IS_ERR(cell))
				return PTR_ERR(cell);
			afs_put_cell(params->cell);
			params->cell = cell;
			break;

		case afs_opt_rwpath:
			params->rwpath = 1;
			break;

		case afs_opt_vol:
			*devname = args[0].from;
			break;

		case afs_opt_autocell:
			params->autocell = 1;
			break;

		default:
			printk(KERN_ERR "kAFS:"
			       " Unknown or invalid mount option: '%s'\n", p);
			return -EINVAL;
		}
	}

	_leave(" = 0");
	return 0;
}

/*
 * parse a device name to get cell name, volume name, volume type and R/W
 * selector
 * - this can be one of the following:
 *	"%[cell:]volume[.]"		R/W volume
 *	"#[cell:]volume[.]"		R/O or R/W volume (rwpath=0),
 *					 or R/W (rwpath=1) volume
 *	"%[cell:]volume.readonly"	R/O volume
 *	"#[cell:]volume.readonly"	R/O volume
 *	"%[cell:]volume.backup"		Backup volume
 *	"#[cell:]volume.backup"		Backup volume
 */
static int afs_parse_device_name(struct afs_mount_params *params,
				 const char *name)
{
	struct afs_cell *cell;
	const char *cellname, *suffix;
	int cellnamesz;

	_enter(",%s", name);

	if (!name) {
		printk(KERN_ERR "kAFS: no volume name specified\n");
		return -EINVAL;
	}

	if ((name[0] != '%' && name[0] != '#') || !name[1]) {
		printk(KERN_ERR "kAFS: unparsable volume name\n");
		return -EINVAL;
	}

	/* determine the type of volume we're looking for */
	params->type = AFSVL_ROVOL;
	params->force = false;
	if (params->rwpath || name[0] == '%') {
		params->type = AFSVL_RWVOL;
		params->force = true;
	}
	name++;

	/* split the cell name out if there is one */
	params->volname = strchr(name, ':');
	if (params->volname) {
		cellname = name;
		cellnamesz = params->volname - name;
		params->volname++;
	} else {
		params->volname = name;
		cellname = NULL;
		cellnamesz = 0;
	}

	/* the volume type is further affected by a possible suffix */
	suffix = strrchr(params->volname, '.');
	if (suffix) {
		if (strcmp(suffix, ".readonly") == 0) {
			params->type = AFSVL_ROVOL;
			params->force = true;
		} else if (strcmp(suffix, ".backup") == 0) {
			params->type = AFSVL_BACKVOL;
			params->force = true;
		} else if (suffix[1] == 0) {
		} else {
			suffix = NULL;
		}
	}

	params->volnamesz = suffix ?
		suffix - params->volname : strlen(params->volname);

	_debug("cell %*.*s [%p]",
	       cellnamesz, cellnamesz, cellname ?: "", params->cell);

	/* lookup the cell record */
	if (cellname || !params->cell) {
		cell = afs_cell_lookup(cellname, cellnamesz, true);
		if (IS_ERR(cell)) {
			printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
			       cellnamesz, cellnamesz, cellname ?: "");
			return PTR_ERR(cell);
		}
		afs_put_cell(params->cell);
		params->cell = cell;
	}

	_debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
	       params->cell->name, params->cell,
	       params->volnamesz, params->volnamesz, params->volname,
	       suffix ?: "-", params->type, params->force ? " FORCE" : "");

	return 0;
}

/*
 * check a superblock to see if it's the one we're looking for
 */
static int afs_test_super(struct super_block *sb, void *data)
{
	struct afs_super_info *as1 = data;
	struct afs_super_info *as = sb->s_fs_info;

	return as->volume == as1->volume;
}

static int afs_set_super(struct super_block *sb, void *data)
{
	sb->s_fs_info = data;
	return set_anon_super(sb, NULL);
}

/*
 * fill in the superblock
 */
static int afs_fill_super(struct super_block *sb,
			  struct afs_mount_params *params)
{
	struct afs_super_info *as = sb->s_fs_info;
	struct afs_fid fid;
	struct inode *inode = NULL;
	int ret;

	_enter("");

	/* fill in the superblock */
	sb->s_blocksize		= PAGE_CACHE_SIZE;
	sb->s_blocksize_bits	= PAGE_CACHE_SHIFT;
	sb->s_magic		= AFS_FS_MAGIC;
	sb->s_op		= &afs_super_ops;
	sb->s_bdi		= &as->volume->bdi;
	strlcpy(sb->s_id, as->volume->vlocation->vldb.name, sizeof(sb->s_id));

	/* allocate the root inode and dentry */
	fid.vid		= as->volume->vid;
	fid.vnode	= 1;
	fid.unique	= 1;
	inode = afs_iget(sb, params->key, &fid, NULL, NULL);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	if (params->autocell)
		set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);

	ret = -ENOMEM;
	sb->s_root = d_make_root(inode);
	if (!sb->s_root)
		goto error;

	sb->s_d_op = &afs_fs_dentry_operations;

	_leave(" = 0");
	return 0;

error:
	_leave(" = %d", ret);
	return ret;
}

/*
 * get an AFS superblock
 */
static struct dentry *afs_mount(struct file_system_type *fs_type,
		      int flags, const char *dev_name, void *options)
{
	struct afs_mount_params params;
	struct super_block *sb;
	struct afs_volume *vol;
	struct key *key;
	char *new_opts = kstrdup(options, GFP_KERNEL);
	struct afs_super_info *as;
	int ret;

	_enter(",,%s,%p", dev_name, options);

	memset(&params, 0, sizeof(params));

	ret = -EINVAL;
	if (current->nsproxy->net_ns != &init_net)
		goto error;

	/* parse the options and device name */
	if (options) {
		ret = afs_parse_options(&params, options, &dev_name);
		if (ret < 0)
			goto error;
	}

	ret = afs_parse_device_name(&params, dev_name);
	if (ret < 0)
		goto error;

	/* try and do the mount securely */
	key = afs_request_key(params.cell);
	if (IS_ERR(key)) {
		_leave(" = %ld [key]", PTR_ERR(key));
		ret = PTR_ERR(key);
		goto error;
	}
	params.key = key;

	/* parse the device name */
	vol = afs_volume_lookup(&params);
	if (IS_ERR(vol)) {
		ret = PTR_ERR(vol);
		goto error;
	}

	/* allocate a superblock info record */
	as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
	if (!as) {
		ret = -ENOMEM;
		afs_put_volume(vol);
		goto error;
	}
	as->volume = vol;

	/* allocate a deviceless superblock */
	sb = sget(fs_type, afs_test_super, afs_set_super, flags, as);
	if (IS_ERR(sb)) {
		ret = PTR_ERR(sb);
		afs_put_volume(vol);
		kfree(as);
		goto error;
	}

	if (!sb->s_root) {
		/* initial superblock/root creation */
		_debug("create");
		ret = afs_fill_super(sb, &params);
		if (ret < 0) {
			deactivate_locked_super(sb);
			goto error;
		}
		save_mount_options(sb, new_opts);
		sb->s_flags |= MS_ACTIVE;
	} else {
		_debug("reuse");
		ASSERTCMP(sb->s_flags, &, MS_ACTIVE);
		afs_put_volume(vol);
		kfree(as);
	}

	afs_put_cell(params.cell);
	kfree(new_opts);
	_leave(" = 0 [%p]", sb);
	return dget(sb->s_root);

error:
	afs_put_cell(params.cell);
	key_put(params.key);
	kfree(new_opts);
	_leave(" = %d", ret);
	return ERR_PTR(ret);
}

static void afs_kill_super(struct super_block *sb)
{
	struct afs_super_info *as = sb->s_fs_info;
	kill_anon_super(sb);
	afs_put_volume(as->volume);
	kfree(as);
}

/*
 * initialise an inode cache slab element prior to any use
 */
static void afs_i_init_once(void *_vnode)
{
	struct afs_vnode *vnode = _vnode;

	memset(vnode, 0, sizeof(*vnode));
	inode_init_once(&vnode->vfs_inode);
	init_waitqueue_head(&vnode->update_waitq);
	mutex_init(&vnode->permits_lock);
	mutex_init(&vnode->validate_lock);
	spin_lock_init(&vnode->writeback_lock);
	spin_lock_init(&vnode->lock);
	INIT_LIST_HEAD(&vnode->writebacks);
	INIT_LIST_HEAD(&vnode->pending_locks);
	INIT_LIST_HEAD(&vnode->granted_locks);
	INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
	INIT_WORK(&vnode->cb_broken_work, afs_broken_callback_work);
}

/*
 * allocate an AFS inode struct from our slab cache
 */
static struct inode *afs_alloc_inode(struct super_block *sb)
{
	struct afs_vnode *vnode;

	vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
	if (!vnode)
		return NULL;

	atomic_inc(&afs_count_active_inodes);

	memset(&vnode->fid, 0, sizeof(vnode->fid));
	memset(&vnode->status, 0, sizeof(vnode->status));

	vnode->volume		= NULL;
	vnode->update_cnt	= 0;
	vnode->flags		= 1 << AFS_VNODE_UNSET;
	vnode->cb_promised	= false;

	_leave(" = %p", &vnode->vfs_inode);
	return &vnode->vfs_inode;
}

static void afs_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	struct afs_vnode *vnode = AFS_FS_I(inode);
	kmem_cache_free(afs_inode_cachep, vnode);
}

/*
 * destroy an AFS inode struct
 */
static void afs_destroy_inode(struct inode *inode)
{
	struct afs_vnode *vnode = AFS_FS_I(inode);

	_enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);

	_debug("DESTROY INODE %p", inode);

	ASSERTCMP(vnode->server, ==, NULL);

	call_rcu(&inode->i_rcu, afs_i_callback);
	atomic_dec(&afs_count_active_inodes);
}

/*
 * return information about an AFS volume
 */
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct afs_volume_status vs;
	struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode);
	struct key *key;
	int ret;

	key = afs_request_key(vnode->volume->cell);
	if (IS_ERR(key))
		return PTR_ERR(key);

	ret = afs_vnode_get_volume_status(vnode, key, &vs);
	key_put(key);
	if (ret < 0) {
		_leave(" = %d", ret);
		return ret;
	}

	buf->f_type	= dentry->d_sb->s_magic;
	buf->f_bsize	= AFS_BLOCK_SIZE;
	buf->f_namelen	= AFSNAMEMAX - 1;

	if (vs.max_quota == 0)
		buf->f_blocks = vs.part_max_blocks;
	else
		buf->f_blocks = vs.max_quota;
	buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
	return 0;
}
Commit	Line	Data
ec26815a DH	1	/* AFS superblock handling
ec26815a DH	2	*
08e0e7c8	3	* Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
1da177e4 LT	4	*
	5	* This software may be freely redistributed under the terms of the
	6	* GNU General Public License.
	7	*
	8	* You should have received a copy of the GNU General Public License
	9	* along with this program; if not, write to the Free Software
	10	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	11	*
	12	* Authors: David Howells <dhowells@redhat.com>
44d1b980	13	* David Woodhouse <dwmw2@infradead.org>
1da177e4 LT	14	*
	15	*/
	16
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
bec5eb61	19	#include <linux/mount.h>
1da177e4 LT	20	#include <linux/init.h>
	21	#include <linux/slab.h>
	22	#include <linux/fs.h>
	23	#include <linux/pagemap.h>
80c72fe4	24	#include <linux/parser.h>
45222b9e	25	#include <linux/statfs.h>
e8edc6e0	26	#include <linux/sched.h>
f74f70f8 EB	27	#include <linux/nsproxy.h>
f74f70f8 EB	28	#include <net/net_namespace.h>
1da177e4 LT	29	#include "internal.h"
	30
	31	#define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */
	32
51cc5068	33	static void afs_i_init_once(void *foo);
f7442b3b AV	34	static struct dentry afs_mount(struct file_system_type fs_type,
f7442b3b AV	35	int flags, const char dev_name, void data);
dde194a6	36	static void afs_kill_super(struct super_block *sb);
1da177e4	37	static struct inode afs_alloc_inode(struct super_block sb);
1da177e4	38	static void afs_destroy_inode(struct inode *inode);
45222b9e	39	static int afs_statfs(struct dentry dentry, struct kstatfs buf);
1da177e4	40
1f5ce9e9	41	struct file_system_type afs_fs_type = {
1da177e4 LT	42	.owner = THIS_MODULE,
1da177e4 LT	43	.name = "afs",
f7442b3b	44	.mount = afs_mount,
dde194a6	45	.kill_sb = afs_kill_super,
80c72fe4	46	.fs_flags = 0,
1da177e4 LT	47	};
1da177e4 LT	48
ee9b6d61	49	static const struct super_operations afs_super_ops = {
45222b9e	50	.statfs = afs_statfs,
1da177e4	51	.alloc_inode = afs_alloc_inode,
bec5eb61	52	.drop_inode = afs_drop_inode,
1da177e4	53	.destroy_inode = afs_destroy_inode,
b57922d9	54	.evict_inode = afs_evict_inode,
969729d5	55	.show_options = generic_show_options,
1da177e4 LT	56	};
1da177e4 LT	57
e18b890b	58	static struct kmem_cache *afs_inode_cachep;
1da177e4 LT	59	static atomic_t afs_count_active_inodes;
1da177e4 LT	60
80c72fe4 DH	61	enum {
	62	afs_no_opt,
	63	afs_opt_cell,
	64	afs_opt_rwpath,
	65	afs_opt_vol,
bec5eb61	66	afs_opt_autocell,
80c72fe4 DH	67	};
80c72fe4 DH	68
a447c093	69	static const match_table_t afs_options_list = {
80c72fe4 DH	70	{ afs_opt_cell, "cell=%s" },
	71	{ afs_opt_rwpath, "rwpath" },
	72	{ afs_opt_vol, "vol=%s" },
bec5eb61	73	{ afs_opt_autocell, "autocell" },
80c72fe4 DH	74	{ afs_no_opt, NULL },
	75	};
	76
1da177e4 LT	77	/*
	78	* initialise the filesystem
	79	*/
	80	int __init afs_fs_init(void)
	81	{
	82	int ret;
	83
	84	_enter("");
	85
1da177e4 LT	86	/* create ourselves an inode cache */
	87	atomic_set(&afs_count_active_inodes, 0);
	88
	89	ret = -ENOMEM;
	90	afs_inode_cachep = kmem_cache_create("afs_inode_cache",
	91	sizeof(struct afs_vnode),
	92	0,
	93	SLAB_HWCACHE_ALIGN,
20c2df83	94	afs_i_init_once);
1da177e4 LT	95	if (!afs_inode_cachep) {
	96	printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
	97	return ret;
	98	}
	99
	100	/* now export our filesystem to lesser mortals */
	101	ret = register_filesystem(&afs_fs_type);
	102	if (ret < 0) {
	103	kmem_cache_destroy(afs_inode_cachep);
08e0e7c8	104	_leave(" = %d", ret);
1da177e4 LT	105	return ret;
	106	}
	107
08e0e7c8	108	_leave(" = 0");
1da177e4	109	return 0;
ec26815a	110	}
1da177e4	111
1da177e4 LT	112	/*
	113	* clean up the filesystem
	114	*/
	115	void __exit afs_fs_exit(void)
	116	{
08e0e7c8 DH	117	_enter("");
	118
	119	afs_mntpt_kill_timer();
1da177e4 LT	120	unregister_filesystem(&afs_fs_type);
	121
	122	if (atomic_read(&afs_count_active_inodes) != 0) {
	123	printk("kAFS: %d active inode objects still present\n",
	124	atomic_read(&afs_count_active_inodes));
	125	BUG();
	126	}
	127
8c0a8537 KS	128	/*
	129	* Make sure all delayed rcu free inodes are flushed before we
	130	* destroy cache.
	131	*/
	132	rcu_barrier();
1da177e4	133	kmem_cache_destroy(afs_inode_cachep);
08e0e7c8	134	_leave("");
ec26815a	135	}
1da177e4	136
1da177e4 LT	137	/*
	138	* parse the mount options
	139	* - this function has been shamelessly adapted from the ext3 fs which
	140	* shamelessly adapted it from the msdos fs
	141	*/
00d3b7a4 DH	142	static int afs_parse_options(struct afs_mount_params *params,
00d3b7a4 DH	143	char options, const char *devname)
1da177e4	144	{
08e0e7c8	145	struct afs_cell *cell;
80c72fe4 DH	146	substring_t args[MAX_OPT_ARGS];
	147	char *p;
	148	int token;
1da177e4 LT	149
	150	_enter("%s", options);
	151
	152	options[PAGE_SIZE - 1] = 0;
	153
80c72fe4 DH	154	while ((p = strsep(&options, ","))) {
	155	if (!*p)
	156	continue;
1da177e4	157
80c72fe4 DH	158	token = match_token(p, afs_options_list, args);
	159	switch (token) {
	160	case afs_opt_cell:
	161	cell = afs_cell_lookup(args[0].from,
bec5eb61	162	args[0].to - args[0].from,
bec5eb61	163	false);
08e0e7c8 DH	164	if (IS_ERR(cell))
08e0e7c8 DH	165	return PTR_ERR(cell);
00d3b7a4 DH	166	afs_put_cell(params->cell);
00d3b7a4 DH	167	params->cell = cell;
80c72fe4 DH	168	break;
	169
	170	case afs_opt_rwpath:
	171	params->rwpath = 1;
	172	break;
	173
	174	case afs_opt_vol:
	175	*devname = args[0].from;
	176	break;
	177
bec5eb61	178	case afs_opt_autocell:
	179	params->autocell = 1;
	180	break;
	181
80c72fe4 DH	182	default:
	183	printk(KERN_ERR "kAFS:"
	184	" Unknown or invalid mount option: '%s'\n", p);
	185	return -EINVAL;
1da177e4	186	}
1da177e4 LT	187	}
1da177e4 LT	188
80c72fe4 DH	189	_leave(" = 0");
80c72fe4 DH	190	return 0;
ec26815a	191	}
1da177e4	192
00d3b7a4 DH	193	/*
	194	* parse a device name to get cell name, volume name, volume type and R/W
	195	* selector
	196	* - this can be one of the following:
	197	* "%[cell:]volume[.]" R/W volume
	198	* "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
	199	* or R/W (rwpath=1) volume
	200	* "%[cell:]volume.readonly" R/O volume
	201	* "#[cell:]volume.readonly" R/O volume
	202	* "%[cell:]volume.backup" Backup volume
	203	* "#[cell:]volume.backup" Backup volume
	204	*/
	205	static int afs_parse_device_name(struct afs_mount_params *params,
	206	const char *name)
	207	{
	208	struct afs_cell *cell;
	209	const char cellname, suffix;
	210	int cellnamesz;
	211
	212	_enter(",%s", name);
	213
	214	if (!name) {
	215	printk(KERN_ERR "kAFS: no volume name specified\n");
	216	return -EINVAL;
	217	}
	218
	219	if ((name[0] != '%' && name[0] != '#') \|\| !name[1]) {
	220	printk(KERN_ERR "kAFS: unparsable volume name\n");
	221	return -EINVAL;
	222	}
	223
	224	/* determine the type of volume we're looking for */
	225	params->type = AFSVL_ROVOL;
	226	params->force = false;
	227	if (params->rwpath \|\| name[0] == '%') {
	228	params->type = AFSVL_RWVOL;
	229	params->force = true;
	230	}
	231	name++;
	232
	233	/* split the cell name out if there is one */
	234	params->volname = strchr(name, ':');
	235	if (params->volname) {
	236	cellname = name;
	237	cellnamesz = params->volname - name;
	238	params->volname++;
	239	} else {
	240	params->volname = name;
	241	cellname = NULL;
	242	cellnamesz = 0;
	243	}
	244
	245	/* the volume type is further affected by a possible suffix */
	246	suffix = strrchr(params->volname, '.');
	247	if (suffix) {
	248	if (strcmp(suffix, ".readonly") == 0) {
	249	params->type = AFSVL_ROVOL;
	250	params->force = true;
	251	} else if (strcmp(suffix, ".backup") == 0) {
	252	params->type = AFSVL_BACKVOL;
	253	params->force = true;
	254	} else if (suffix[1] == 0) {
	255	} else {
	256	suffix = NULL;
257	}
258	}
259
260	params->volnamesz = suffix ?
261	suffix - params->volname : strlen(params->volname);
262
263	_debug("cell %.s [%p]",
264	cellnamesz, cellnamesz, cellname ?: "", params->cell);
265
266	/* lookup the cell record */
267	if (cellname \|\| !params->cell) {
bec5eb61	268	cell = afs_cell_lookup(cellname, cellnamesz, true);
00d3b7a4	269	if (IS_ERR(cell)) {
bec5eb61	270	printk(KERN_ERR "kAFS: unable to lookup cell '%.s'\n",
bec5eb61	271	cellnamesz, cellnamesz, cellname ?: "");
00d3b7a4 DH	272	return PTR_ERR(cell);
	273	}
	274	afs_put_cell(params->cell);
	275	params->cell = cell;
	276	}
	277
	278	_debug("CELL:%s [%p] VOLUME:%.s SUFFIX:%s TYPE:%d%s",
	279	params->cell->name, params->cell,
	280	params->volnamesz, params->volnamesz, params->volname,
	281	suffix ?: "-", params->type, params->force ? " FORCE" : "");
	282
	283	return 0;
	284	}
	285
1da177e4 LT	286	/*
	287	* check a superblock to see if it's the one we're looking for
	288	*/
	289	static int afs_test_super(struct super_block sb, void data)
	290	{
dde194a6	291	struct afs_super_info *as1 = data;
1da177e4 LT	292	struct afs_super_info *as = sb->s_fs_info;
1da177e4 LT	293
dde194a6 AV	294	return as->volume == as1->volume;
	295	}
	296
	297	static int afs_set_super(struct super_block sb, void data)
	298	{
	299	sb->s_fs_info = data;
	300	return set_anon_super(sb, NULL);
ec26815a	301	}
1da177e4	302
1da177e4 LT	303	/*
	304	* fill in the superblock
	305	*/
dde194a6 AV	306	static int afs_fill_super(struct super_block *sb,
dde194a6 AV	307	struct afs_mount_params *params)
1da177e4	308	{
dde194a6	309	struct afs_super_info *as = sb->s_fs_info;
1da177e4	310	struct afs_fid fid;
1da177e4 LT	311	struct inode *inode = NULL;
	312	int ret;
	313
08e0e7c8	314	_enter("");
1da177e4	315
1da177e4 LT	316	/* fill in the superblock */
	317	sb->s_blocksize = PAGE_CACHE_SIZE;
	318	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	319	sb->s_magic = AFS_FS_MAGIC;
	320	sb->s_op = &afs_super_ops;
e1da0222	321	sb->s_bdi = &as->volume->bdi;
2e41ae22	322	strlcpy(sb->s_id, as->volume->vlocation->vldb.name, sizeof(sb->s_id));
1da177e4 LT	323
	324	/* allocate the root inode and dentry */
	325	fid.vid = as->volume->vid;
	326	fid.vnode = 1;
	327	fid.unique = 1;
260a9803	328	inode = afs_iget(sb, params->key, &fid, NULL, NULL);
08e0e7c8	329	if (IS_ERR(inode))
dde194a6	330	return PTR_ERR(inode);
1da177e4	331
bec5eb61	332	if (params->autocell)
	333	set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
	334
1da177e4	335	ret = -ENOMEM;
48fde701 AV	336	sb->s_root = d_make_root(inode);
48fde701 AV	337	if (!sb->s_root)
1da177e4 LT	338	goto error;
1da177e4 LT	339
d61dcce2	340	sb->s_d_op = &afs_fs_dentry_operations;
1da177e4	341
08e0e7c8	342	_leave(" = 0");
1da177e4 LT	343	return 0;
1da177e4 LT	344
ec26815a	345	error:
08e0e7c8	346	_leave(" = %d", ret);
1da177e4	347	return ret;
ec26815a	348	}
1da177e4	349
1da177e4 LT	350	/*
1da177e4 LT	351	* get an AFS superblock
1da177e4	352	*/
f7442b3b AV	353	static struct dentry afs_mount(struct file_system_type fs_type,
f7442b3b AV	354	int flags, const char dev_name, void options)
1da177e4 LT	355	{
	356	struct afs_mount_params params;
	357	struct super_block *sb;
08e0e7c8	358	struct afs_volume *vol;
00d3b7a4	359	struct key *key;
969729d5	360	char *new_opts = kstrdup(options, GFP_KERNEL);
dde194a6	361	struct afs_super_info *as;
1da177e4 LT	362	int ret;
	363
	364	_enter(",,%s,%p", dev_name, options);
	365
	366	memset(&params, 0, sizeof(params));
	367
f74f70f8 EB	368	ret = -EINVAL;
	369	if (current->nsproxy->net_ns != &init_net)
	370	goto error;
	371
00d3b7a4	372	/* parse the options and device name */
1da177e4	373	if (options) {
00d3b7a4	374	ret = afs_parse_options(&params, options, &dev_name);
1da177e4 LT	375	if (ret < 0)
1da177e4 LT	376	goto error;
1da177e4 LT	377	}
1da177e4 LT	378
00d3b7a4 DH	379	ret = afs_parse_device_name(&params, dev_name);
	380	if (ret < 0)
	381	goto error;
	382
	383	/* try and do the mount securely */
	384	key = afs_request_key(params.cell);
	385	if (IS_ERR(key)) {
	386	_leave(" = %ld [key]", PTR_ERR(key));
	387	ret = PTR_ERR(key);
	388	goto error;
	389	}
	390	params.key = key;
	391
1da177e4	392	/* parse the device name */
00d3b7a4	393	vol = afs_volume_lookup(&params);
08e0e7c8 DH	394	if (IS_ERR(vol)) {
08e0e7c8 DH	395	ret = PTR_ERR(vol);
1da177e4	396	goto error;
08e0e7c8	397	}
dde194a6 AV	398
	399	/* allocate a superblock info record */
	400	as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
	401	if (!as) {
	402	ret = -ENOMEM;
	403	afs_put_volume(vol);
	404	goto error;
	405	}
	406	as->volume = vol;
1da177e4 LT	407
1da177e4 LT	408	/* allocate a deviceless superblock */
9249e17f	409	sb = sget(fs_type, afs_test_super, afs_set_super, flags, as);
08e0e7c8 DH	410	if (IS_ERR(sb)) {
08e0e7c8 DH	411	ret = PTR_ERR(sb);
dde194a6 AV	412	afs_put_volume(vol);
dde194a6 AV	413	kfree(as);
1da177e4	414	goto error;
08e0e7c8	415	}
1da177e4	416
436058a4 DH	417	if (!sb->s_root) {
	418	/* initial superblock/root creation */
	419	_debug("create");
436058a4 DH	420	ret = afs_fill_super(sb, &params);
436058a4 DH	421	if (ret < 0) {
6f5bbff9	422	deactivate_locked_super(sb);
436058a4 DH	423	goto error;
436058a4 DH	424	}
2a32cebd	425	save_mount_options(sb, new_opts);
436058a4 DH	426	sb->s_flags \|= MS_ACTIVE;
	427	} else {
	428	_debug("reuse");
	429	ASSERTCMP(sb->s_flags, &, MS_ACTIVE);
dde194a6 AV	430	afs_put_volume(vol);
dde194a6 AV	431	kfree(as);
1da177e4	432	}
1da177e4	433
00d3b7a4	434	afs_put_cell(params.cell);
2a32cebd	435	kfree(new_opts);
08e0e7c8	436	_leave(" = 0 [%p]", sb);
f7442b3b	437	return dget(sb->s_root);
1da177e4	438
ec26815a	439	error:
00d3b7a4 DH	440	afs_put_cell(params.cell);
00d3b7a4 DH	441	key_put(params.key);
969729d5	442	kfree(new_opts);
1da177e4	443	_leave(" = %d", ret);
f7442b3b	444	return ERR_PTR(ret);
ec26815a	445	}
1da177e4	446
dde194a6	447	static void afs_kill_super(struct super_block *sb)
1da177e4 LT	448	{
1da177e4 LT	449	struct afs_super_info *as = sb->s_fs_info;
dde194a6	450	kill_anon_super(sb);
1da177e4	451	afs_put_volume(as->volume);
dde194a6	452	kfree(as);
ec26815a	453	}
1da177e4	454
1da177e4 LT	455	/*
	456	* initialise an inode cache slab element prior to any use
	457	*/
51cc5068	458	static void afs_i_init_once(void *_vnode)
1da177e4	459	{
ec26815a	460	struct afs_vnode *vnode = _vnode;
1da177e4	461
a35afb83 CL	462	memset(vnode, 0, sizeof(*vnode));
	463	inode_init_once(&vnode->vfs_inode);
	464	init_waitqueue_head(&vnode->update_waitq);
	465	mutex_init(&vnode->permits_lock);
	466	mutex_init(&vnode->validate_lock);
	467	spin_lock_init(&vnode->writeback_lock);
	468	spin_lock_init(&vnode->lock);
	469	INIT_LIST_HEAD(&vnode->writebacks);
e8d6c554 DH	470	INIT_LIST_HEAD(&vnode->pending_locks);
	471	INIT_LIST_HEAD(&vnode->granted_locks);
	472	INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
a35afb83	473	INIT_WORK(&vnode->cb_broken_work, afs_broken_callback_work);
ec26815a	474	}
1da177e4	475
1da177e4 LT	476	/*
	477	* allocate an AFS inode struct from our slab cache
	478	*/
	479	static struct inode afs_alloc_inode(struct super_block sb)
	480	{
	481	struct afs_vnode *vnode;
	482
ec26815a	483	vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
1da177e4 LT	484	if (!vnode)
	485	return NULL;
	486
	487	atomic_inc(&afs_count_active_inodes);
	488
	489	memset(&vnode->fid, 0, sizeof(vnode->fid));
	490	memset(&vnode->status, 0, sizeof(vnode->status));
	491
	492	vnode->volume = NULL;
	493	vnode->update_cnt = 0;
260a9803	494	vnode->flags = 1 << AFS_VNODE_UNSET;
08e0e7c8	495	vnode->cb_promised = false;
1da177e4	496
0f300ca9	497	_leave(" = %p", &vnode->vfs_inode);
1da177e4	498	return &vnode->vfs_inode;
ec26815a	499	}
1da177e4	500
fa0d7e3d NP	501	static void afs_i_callback(struct rcu_head *head)
	502	{
	503	struct inode *inode = container_of(head, struct inode, i_rcu);
	504	struct afs_vnode *vnode = AFS_FS_I(inode);
fa0d7e3d NP	505	kmem_cache_free(afs_inode_cachep, vnode);
	506	}
	507
1da177e4 LT	508	/*
	509	* destroy an AFS inode struct
	510	*/
	511	static void afs_destroy_inode(struct inode *inode)
	512	{
08e0e7c8 DH	513	struct afs_vnode *vnode = AFS_FS_I(inode);
08e0e7c8 DH	514
0f300ca9	515	_enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
1da177e4	516
08e0e7c8 DH	517	_debug("DESTROY INODE %p", inode);
	518
	519	ASSERTCMP(vnode->server, ==, NULL);
	520
fa0d7e3d	521	call_rcu(&inode->i_rcu, afs_i_callback);
1da177e4	522	atomic_dec(&afs_count_active_inodes);
ec26815a	523	}
45222b9e DH	524
	525	/*
	526	* return information about an AFS volume
	527	*/
	528	static int afs_statfs(struct dentry dentry, struct kstatfs buf)
	529	{
	530	struct afs_volume_status vs;
	531	struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode);
	532	struct key *key;
	533	int ret;
	534
	535	key = afs_request_key(vnode->volume->cell);
	536	if (IS_ERR(key))
	537	return PTR_ERR(key);
	538
	539	ret = afs_vnode_get_volume_status(vnode, key, &vs);
	540	key_put(key);
	541	if (ret < 0) {
	542	_leave(" = %d", ret);
	543	return ret;
	544	}
	545
	546	buf->f_type = dentry->d_sb->s_magic;
	547	buf->f_bsize = AFS_BLOCK_SIZE;
	548	buf->f_namelen = AFSNAMEMAX - 1;
	549
	550	if (vs.max_quota == 0)
	551	buf->f_blocks = vs.part_max_blocks;
	552	else
	553	buf->f_blocks = vs.max_quota;
	554	buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
	555	return 0;
	556	}