[net-next-2.6.git] / drivers / base / devtmpfs.c

/*
 * devtmpfs - kernel-maintained tmpfs-based /dev
 *
 * Copyright (C) 2009, Kay Sievers <kay.sievers@vrfy.org>
 *
 * During bootup, before any driver core device is registered,
 * devtmpfs, a tmpfs-based filesystem is created. Every driver-core
 * device which requests a device node, will add a node in this
 * filesystem.
 * By default, all devices are named after the the name of the
 * device, owned by root and have a default mode of 0600. Subsystems
 * can overwrite the default setting if needed.
 */

#include <linux/kernel.h>
#include <linux/syscalls.h>
#include <linux/mount.h>
#include <linux/device.h>
#include <linux/genhd.h>
#include <linux/namei.h>
#include <linux/fs.h>
#include <linux/shmem_fs.h>
#include <linux/ramfs.h>
#include <linux/cred.h>
#include <linux/sched.h>
#include <linux/init_task.h>
#include <linux/slab.h>

static struct vfsmount *dev_mnt;

#if defined CONFIG_DEVTMPFS_MOUNT
static int mount_dev = 1;
#else
static int mount_dev;
#endif

static DEFINE_MUTEX(dirlock);

static int __init mount_param(char *str)
{
	mount_dev = simple_strtoul(str, NULL, 0);
	return 1;
}
__setup("devtmpfs.mount=", mount_param);

static struct dentry *dev_mount(struct file_system_type *fs_type, int flags,
		      const char *dev_name, void *data)
{
#ifdef CONFIG_TMPFS
	return mount_single(fs_type, flags, data, shmem_fill_super);
#else
	return mount_single(fs_type, flags, data, ramfs_fill_super);
#endif
}

static struct file_system_type dev_fs_type = {
	.name = "devtmpfs",
	.mount = dev_mount,
	.kill_sb = kill_litter_super,
};

#ifdef CONFIG_BLOCK
static inline int is_blockdev(struct device *dev)
{
	return dev->class == &block_class;
}
#else
static inline int is_blockdev(struct device *dev) { return 0; }
#endif

static int dev_mkdir(const char *name, mode_t mode)
{
	struct nameidata nd;
	struct dentry *dentry;
	int err;

	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
			      name, LOOKUP_PARENT, &nd);
	if (err)
		return err;

	dentry = lookup_create(&nd, 1);
	if (!IS_ERR(dentry)) {
		err = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
		if (!err)
			/* mark as kernel-created inode */
			dentry->d_inode->i_private = &dev_mnt;
		dput(dentry);
	} else {
		err = PTR_ERR(dentry);
	}

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
	path_put(&nd.path);
	return err;
}

static int create_path(const char *nodepath)
{
	int err;

	mutex_lock(&dirlock);
	err = dev_mkdir(nodepath, 0755);
	if (err == -ENOENT) {
		char *path;
		char *s;

		/* parent directories do not exist, create them */
		path = kstrdup(nodepath, GFP_KERNEL);
		if (!path) {
			err = -ENOMEM;
			goto out;
		}
		s = path;
		for (;;) {
			s = strchr(s, '/');
			if (!s)
				break;
			s[0] = '\0';
			err = dev_mkdir(path, 0755);
			if (err && err != -EEXIST)
				break;
			s[0] = '/';
			s++;
		}
		kfree(path);
	}
out:
	mutex_unlock(&dirlock);
	return err;
}

int devtmpfs_create_node(struct device *dev)
{
	const char *tmp = NULL;
	const char *nodename;
	const struct cred *curr_cred;
	mode_t mode = 0;
	struct nameidata nd;
	struct dentry *dentry;
	int err;

	if (!dev_mnt)
		return 0;

	nodename = device_get_devnode(dev, &mode, &tmp);
	if (!nodename)
		return -ENOMEM;

	if (mode == 0)
		mode = 0600;
	if (is_blockdev(dev))
		mode |= S_IFBLK;
	else
		mode |= S_IFCHR;

	curr_cred = override_creds(&init_cred);

	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
			      nodename, LOOKUP_PARENT, &nd);
	if (err == -ENOENT) {
		create_path(nodename);
		err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
				      nodename, LOOKUP_PARENT, &nd);
	}
	if (err)
		goto out;

	dentry = lookup_create(&nd, 0);
	if (!IS_ERR(dentry)) {
		err = vfs_mknod(nd.path.dentry->d_inode,
				dentry, mode, dev->devt);
		if (!err) {
			struct iattr newattrs;

			/* fixup possibly umasked mode */
			newattrs.ia_mode = mode;
			newattrs.ia_valid = ATTR_MODE;
			mutex_lock(&dentry->d_inode->i_mutex);
			notify_change(dentry, &newattrs);
			mutex_unlock(&dentry->d_inode->i_mutex);

			/* mark as kernel-created inode */
			dentry->d_inode->i_private = &dev_mnt;
		}
		dput(dentry);
	} else {
		err = PTR_ERR(dentry);
	}

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
	path_put(&nd.path);
out:
	kfree(tmp);
	revert_creds(curr_cred);
	return err;
}

static int dev_rmdir(const char *name)
{
	struct nameidata nd;
	struct dentry *dentry;
	int err;

	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
			      name, LOOKUP_PARENT, &nd);
	if (err)
		return err;

	mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
	dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
	if (!IS_ERR(dentry)) {
		if (dentry->d_inode) {
			if (dentry->d_inode->i_private == &dev_mnt)
				err = vfs_rmdir(nd.path.dentry->d_inode,
						dentry);
			else
				err = -EPERM;
		} else {
			err = -ENOENT;
		}
		dput(dentry);
	} else {
		err = PTR_ERR(dentry);
	}

	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
	path_put(&nd.path);
	return err;
}

static int delete_path(const char *nodepath)
{
	const char *path;
	int err = 0;

	path = kstrdup(nodepath, GFP_KERNEL);
	if (!path)
		return -ENOMEM;

	mutex_lock(&dirlock);
	for (;;) {
		char *base;

		base = strrchr(path, '/');
		if (!base)
			break;
		base[0] = '\0';
		err = dev_rmdir(path);
		if (err)
			break;
	}
	mutex_unlock(&dirlock);

	kfree(path);
	return err;
}

static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *stat)
{
	/* did we create it */
	if (inode->i_private != &dev_mnt)
		return 0;

	/* does the dev_t match */
	if (is_blockdev(dev)) {
		if (!S_ISBLK(stat->mode))
			return 0;
	} else {
		if (!S_ISCHR(stat->mode))
			return 0;
	}
	if (stat->rdev != dev->devt)
		return 0;

	/* ours */
	return 1;
}

int devtmpfs_delete_node(struct device *dev)
{
	const char *tmp = NULL;
	const char *nodename;
	const struct cred *curr_cred;
	struct nameidata nd;
	struct dentry *dentry;
	struct kstat stat;
	int deleted = 1;
	int err;

	if (!dev_mnt)
		return 0;

	nodename = device_get_devnode(dev, NULL, &tmp);
	if (!nodename)
		return -ENOMEM;

	curr_cred = override_creds(&init_cred);
	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
			      nodename, LOOKUP_PARENT, &nd);
	if (err)
		goto out;

	mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
	dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
	if (!IS_ERR(dentry)) {
		if (dentry->d_inode) {
			err = vfs_getattr(nd.path.mnt, dentry, &stat);
			if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
				struct iattr newattrs;
				/*
				 * before unlinking this node, reset permissions
				 * of possible references like hardlinks
				 */
				newattrs.ia_uid = 0;
				newattrs.ia_gid = 0;
				newattrs.ia_mode = stat.mode & ~0777;
				newattrs.ia_valid =
					ATTR_UID|ATTR_GID|ATTR_MODE;
				mutex_lock(&dentry->d_inode->i_mutex);
				notify_change(dentry, &newattrs);
				mutex_unlock(&dentry->d_inode->i_mutex);
				err = vfs_unlink(nd.path.dentry->d_inode,
						 dentry);
				if (!err || err == -ENOENT)
					deleted = 1;
			}
		} else {
			err = -ENOENT;
		}
		dput(dentry);
	} else {
		err = PTR_ERR(dentry);
	}
	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

	path_put(&nd.path);
	if (deleted && strchr(nodename, '/'))
		delete_path(nodename);
out:
	kfree(tmp);
	revert_creds(curr_cred);
	return err;
}

/*
 * If configured, or requested by the commandline, devtmpfs will be
 * auto-mounted after the kernel mounted the root filesystem.
 */
int devtmpfs_mount(const char *mntdir)
{
	int err;

	if (!mount_dev)
		return 0;

	if (!dev_mnt)
		return 0;

	err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL);
	if (err)
		printk(KERN_INFO "devtmpfs: error mounting %i\n", err);
	else
		printk(KERN_INFO "devtmpfs: mounted\n");
	return err;
}

/*
 * Create devtmpfs instance, driver-core devices will add their device
 * nodes here.
 */
int __init devtmpfs_init(void)
{
	int err;
	struct vfsmount *mnt;
	char options[] = "mode=0755";

	err = register_filesystem(&dev_fs_type);
	if (err) {
		printk(KERN_ERR "devtmpfs: unable to register devtmpfs "
		       "type %i\n", err);
		return err;
	}

	mnt = kern_mount_data(&dev_fs_type, options);
	if (IS_ERR(mnt)) {
		err = PTR_ERR(mnt);
		printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err);
		unregister_filesystem(&dev_fs_type);
		return err;
	}
	dev_mnt = mnt;

	printk(KERN_INFO "devtmpfs: initialized\n");
	return 0;
}
Commit	Line	Data
2b2af54a KS	1	/*
	2	* devtmpfs - kernel-maintained tmpfs-based /dev
	3	*
	4	* Copyright (C) 2009, Kay Sievers <kay.sievers@vrfy.org>
	5	*
	6	* During bootup, before any driver core device is registered,
	7	* devtmpfs, a tmpfs-based filesystem is created. Every driver-core
	8	* device which requests a device node, will add a node in this
e454cea2 KS	9	* filesystem.
	10	* By default, all devices are named after the the name of the
	11	* device, owned by root and have a default mode of 0600. Subsystems
	12	* can overwrite the default setting if needed.
2b2af54a KS	13	*/
	14
	15	#include <linux/kernel.h>
	16	#include <linux/syscalls.h>
	17	#include <linux/mount.h>
	18	#include <linux/device.h>
	19	#include <linux/genhd.h>
	20	#include <linux/namei.h>
	21	#include <linux/fs.h>
	22	#include <linux/shmem_fs.h>
da5e4ef7	23	#include <linux/ramfs.h>
2b2af54a	24	#include <linux/cred.h>
e454cea2	25	#include <linux/sched.h>
2b2af54a	26	#include <linux/init_task.h>
5a0e3ad6	27	#include <linux/slab.h>
2b2af54a KS	28
	29	static struct vfsmount *dev_mnt;
	30
	31	#if defined CONFIG_DEVTMPFS_MOUNT
fc14f2fe	32	static int mount_dev = 1;
2b2af54a	33	#else
fc14f2fe	34	static int mount_dev;
2b2af54a KS	35	#endif
2b2af54a KS	36
f1f76f86	37	static DEFINE_MUTEX(dirlock);
ed413ae6	38
2b2af54a KS	39	static int __init mount_param(char *str)
2b2af54a KS	40	{
fc14f2fe	41	mount_dev = simple_strtoul(str, NULL, 0);
2b2af54a KS	42	return 1;
	43	}
	44	__setup("devtmpfs.mount=", mount_param);
	45
fc14f2fe AV	46	static struct dentry dev_mount(struct file_system_type fs_type, int flags,
fc14f2fe AV	47	const char dev_name, void data)
2b2af54a	48	{
da5e4ef7	49	#ifdef CONFIG_TMPFS
fc14f2fe	50	return mount_single(fs_type, flags, data, shmem_fill_super);
da5e4ef7	51	#else
fc14f2fe	52	return mount_single(fs_type, flags, data, ramfs_fill_super);
da5e4ef7	53	#endif
2b2af54a KS	54	}
	55
	56	static struct file_system_type dev_fs_type = {
	57	.name = "devtmpfs",
fc14f2fe	58	.mount = dev_mount,
2b2af54a KS	59	.kill_sb = kill_litter_super,
	60	};
	61
	62	#ifdef CONFIG_BLOCK
	63	static inline int is_blockdev(struct device *dev)
	64	{
	65	return dev->class == &block_class;
	66	}
	67	#else
	68	static inline int is_blockdev(struct device *dev) { return 0; }
	69	#endif
	70
	71	static int dev_mkdir(const char *name, mode_t mode)
	72	{
	73	struct nameidata nd;
	74	struct dentry *dentry;
	75	int err;
	76
	77	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
	78	name, LOOKUP_PARENT, &nd);
	79	if (err)
	80	return err;
	81
	82	dentry = lookup_create(&nd, 1);
	83	if (!IS_ERR(dentry)) {
	84	err = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
015bf43b KS	85	if (!err)
	86	/* mark as kernel-created inode */
	87	dentry->d_inode->i_private = &dev_mnt;
2b2af54a KS	88	dput(dentry);
	89	} else {
	90	err = PTR_ERR(dentry);
	91	}
2b2af54a	92
015bf43b	93	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
2b2af54a KS	94	path_put(&nd.path);
	95	return err;
	96	}
	97
	98	static int create_path(const char *nodepath)
	99	{
015bf43b	100	int err;
2b2af54a	101
f1f76f86	102	mutex_lock(&dirlock);
015bf43b KS	103	err = dev_mkdir(nodepath, 0755);
015bf43b KS	104	if (err == -ENOENT) {
ed413ae6	105	char *path;
2b2af54a KS	106	char *s;
	107
	108	/* parent directories do not exist, create them */
ed413ae6	109	path = kstrdup(nodepath, GFP_KERNEL);
80422738 KS	110	if (!path) {
	111	err = -ENOMEM;
	112	goto out;
	113	}
2b2af54a	114	s = path;
ed413ae6	115	for (;;) {
2b2af54a KS	116	s = strchr(s, '/');
	117	if (!s)
	118	break;
	119	s[0] = '\0';
	120	err = dev_mkdir(path, 0755);
	121	if (err && err != -EEXIST)
	122	break;
	123	s[0] = '/';
	124	s++;
	125	}
ed413ae6	126	kfree(path);
2b2af54a	127	}
80422738	128	out:
f1f76f86	129	mutex_unlock(&dirlock);
2b2af54a KS	130	return err;
	131	}
	132
	133	int devtmpfs_create_node(struct device *dev)
	134	{
	135	const char *tmp = NULL;
	136	const char *nodename;
	137	const struct cred *curr_cred;
e454cea2	138	mode_t mode = 0;
2b2af54a KS	139	struct nameidata nd;
	140	struct dentry *dentry;
	141	int err;
	142
	143	if (!dev_mnt)
	144	return 0;
	145
e454cea2	146	nodename = device_get_devnode(dev, &mode, &tmp);
2b2af54a KS	147	if (!nodename)
	148	return -ENOMEM;
	149
e454cea2 KS	150	if (mode == 0)
e454cea2 KS	151	mode = 0600;
2b2af54a	152	if (is_blockdev(dev))
e454cea2	153	mode \|= S_IFBLK;
2b2af54a	154	else
e454cea2	155	mode \|= S_IFCHR;
2b2af54a KS	156
2b2af54a KS	157	curr_cred = override_creds(&init_cred);
00926996	158
2b2af54a KS	159	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
	160	nodename, LOOKUP_PARENT, &nd);
	161	if (err == -ENOENT) {
2b2af54a KS	162	create_path(nodename);
	163	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
	164	nodename, LOOKUP_PARENT, &nd);
2b2af54a	165	}
00926996 KS	166	if (err)
00926996 KS	167	goto out;
2b2af54a KS	168
	169	dentry = lookup_create(&nd, 0);
	170	if (!IS_ERR(dentry)) {
	171	err = vfs_mknod(nd.path.dentry->d_inode,
	172	dentry, mode, dev->devt);
00926996 KS	173	if (!err) {
	174	struct iattr newattrs;
	175
	176	/* fixup possibly umasked mode */
	177	newattrs.ia_mode = mode;
	178	newattrs.ia_valid = ATTR_MODE;
	179	mutex_lock(&dentry->d_inode->i_mutex);
	180	notify_change(dentry, &newattrs);
	181	mutex_unlock(&dentry->d_inode->i_mutex);
	182
	183	/* mark as kernel-created inode */
2b2af54a	184	dentry->d_inode->i_private = &dev_mnt;
00926996	185	}
2b2af54a KS	186	dput(dentry);
	187	} else {
	188	err = PTR_ERR(dentry);
	189	}
2b2af54a	190
00926996	191	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
2b2af54a KS	192	path_put(&nd.path);
	193	out:
	194	kfree(tmp);
	195	revert_creds(curr_cred);
	196	return err;
	197	}
	198
	199	static int dev_rmdir(const char *name)
	200	{
	201	struct nameidata nd;
	202	struct dentry *dentry;
	203	int err;
	204
	205	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
	206	name, LOOKUP_PARENT, &nd);
	207	if (err)
	208	return err;
	209
	210	mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
	211	dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
	212	if (!IS_ERR(dentry)) {
015bf43b KS	213	if (dentry->d_inode) {
	214	if (dentry->d_inode->i_private == &dev_mnt)
	215	err = vfs_rmdir(nd.path.dentry->d_inode,
	216	dentry);
	217	else
	218	err = -EPERM;
	219	} else {
2b2af54a	220	err = -ENOENT;
015bf43b	221	}
2b2af54a KS	222	dput(dentry);
	223	} else {
	224	err = PTR_ERR(dentry);
	225	}
2b2af54a	226
015bf43b	227	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
2b2af54a KS	228	path_put(&nd.path);
	229	return err;
	230	}
	231
	232	static int delete_path(const char *nodepath)
	233	{
	234	const char *path;
	235	int err = 0;
	236
	237	path = kstrdup(nodepath, GFP_KERNEL);
	238	if (!path)
	239	return -ENOMEM;
	240
f1f76f86	241	mutex_lock(&dirlock);
ed413ae6	242	for (;;) {
2b2af54a KS	243	char *base;
	244
	245	base = strrchr(path, '/');
	246	if (!base)
	247	break;
	248	base[0] = '\0';
	249	err = dev_rmdir(path);
	250	if (err)
	251	break;
	252	}
f1f76f86	253	mutex_unlock(&dirlock);
2b2af54a KS	254
	255	kfree(path);
	256	return err;
	257	}
	258
	259	static int dev_mynode(struct device dev, struct inode inode, struct kstat *stat)
	260	{
	261	/* did we create it */
	262	if (inode->i_private != &dev_mnt)
	263	return 0;
	264
	265	/* does the dev_t match */
	266	if (is_blockdev(dev)) {
	267	if (!S_ISBLK(stat->mode))
	268	return 0;
	269	} else {
	270	if (!S_ISCHR(stat->mode))
	271	return 0;
	272	}
	273	if (stat->rdev != dev->devt)
	274	return 0;
	275
	276	/* ours */
	277	return 1;
	278	}
	279
	280	int devtmpfs_delete_node(struct device *dev)
	281	{
	282	const char *tmp = NULL;
	283	const char *nodename;
	284	const struct cred *curr_cred;
	285	struct nameidata nd;
	286	struct dentry *dentry;
	287	struct kstat stat;
	288	int deleted = 1;
	289	int err;
	290
	291	if (!dev_mnt)
	292	return 0;
	293
e454cea2	294	nodename = device_get_devnode(dev, NULL, &tmp);
2b2af54a KS	295	if (!nodename)
	296	return -ENOMEM;
	297
	298	curr_cred = override_creds(&init_cred);
	299	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
	300	nodename, LOOKUP_PARENT, &nd);
	301	if (err)
	302	goto out;
	303
	304	mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
	305	dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
	306	if (!IS_ERR(dentry)) {
	307	if (dentry->d_inode) {
	308	err = vfs_getattr(nd.path.mnt, dentry, &stat);
	309	if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
5e31d76f KS	310	struct iattr newattrs;
	311	/*
	312	* before unlinking this node, reset permissions
	313	* of possible references like hardlinks
	314	*/
	315	newattrs.ia_uid = 0;
	316	newattrs.ia_gid = 0;
	317	newattrs.ia_mode = stat.mode & ~0777;
	318	newattrs.ia_valid =
	319	ATTR_UID\|ATTR_GID\|ATTR_MODE;
	320	mutex_lock(&dentry->d_inode->i_mutex);
	321	notify_change(dentry, &newattrs);
	322	mutex_unlock(&dentry->d_inode->i_mutex);
2b2af54a KS	323	err = vfs_unlink(nd.path.dentry->d_inode,
	324	dentry);
	325	if (!err \|\| err == -ENOENT)
	326	deleted = 1;
	327	}
	328	} else {
	329	err = -ENOENT;
	330	}
	331	dput(dentry);
	332	} else {
	333	err = PTR_ERR(dentry);
	334	}
	335	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
	336
	337	path_put(&nd.path);
	338	if (deleted && strchr(nodename, '/'))
	339	delete_path(nodename);
	340	out:
	341	kfree(tmp);
	342	revert_creds(curr_cred);
	343	return err;
	344	}
	345
	346	/*
	347	* If configured, or requested by the commandline, devtmpfs will be
	348	* auto-mounted after the kernel mounted the root filesystem.
	349	*/
073120cc	350	int devtmpfs_mount(const char *mntdir)
2b2af54a	351	{
2b2af54a KS	352	int err;
2b2af54a KS	353
fc14f2fe	354	if (!mount_dev)
2b2af54a KS	355	return 0;
	356
	357	if (!dev_mnt)
	358	return 0;
	359
073120cc	360	err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL);
2b2af54a KS	361	if (err)
	362	printk(KERN_INFO "devtmpfs: error mounting %i\n", err);
	363	else
	364	printk(KERN_INFO "devtmpfs: mounted\n");
2b2af54a KS	365	return err;
	366	}
	367
	368	/*
	369	* Create devtmpfs instance, driver-core devices will add their device
	370	* nodes here.
	371	*/
	372	int __init devtmpfs_init(void)
	373	{
	374	int err;
	375	struct vfsmount *mnt;
f776c5ec	376	char options[] = "mode=0755";
2b2af54a KS	377
	378	err = register_filesystem(&dev_fs_type);
	379	if (err) {
	380	printk(KERN_ERR "devtmpfs: unable to register devtmpfs "
	381	"type %i\n", err);
	382	return err;
	383	}
	384
f776c5ec	385	mnt = kern_mount_data(&dev_fs_type, options);
2b2af54a KS	386	if (IS_ERR(mnt)) {
	387	err = PTR_ERR(mnt);
	388	printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err);
	389	unregister_filesystem(&dev_fs_type);
	390	return err;
	391	}
	392	dev_mnt = mnt;
	393
	394	printk(KERN_INFO "devtmpfs: initialized\n");
	395	return 0;
	396	}