[deliverable/linux.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 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/sched.h>
#include <linux/slab.h>
#include <linux/kthread.h>

static struct task_struct *thread;

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

static DEFINE_SPINLOCK(req_lock);

static struct req {
	struct req *next;
	struct completion done;
	int err;
	const char *name;
	umode_t mode;	/* 0 => delete */
	struct device *dev;
} *requests;

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

int devtmpfs_create_node(struct device *dev)
{
	const char *tmp = NULL;
	struct req req;

	if (!thread)
		return 0;

	req.mode = 0;
	req.name = device_get_devnode(dev, &req.mode, &tmp);
	if (!req.name)
		return -ENOMEM;

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

	req.dev = dev;

	init_completion(&req.done);

	spin_lock(&req_lock);
	req.next = requests;
	requests = &req;
	spin_unlock(&req_lock);

	wake_up_process(thread);
	wait_for_completion(&req.done);

	kfree(tmp);

	return req.err;
}

int devtmpfs_delete_node(struct device *dev)
{
	const char *tmp = NULL;
	struct req req;

	if (!thread)
		return 0;

	req.name = device_get_devnode(dev, NULL, &tmp);
	if (!req.name)
		return -ENOMEM;

	req.mode = 0;
	req.dev = dev;

	init_completion(&req.done);

	spin_lock(&req_lock);
	req.next = requests;
	requests = &req;
	spin_unlock(&req_lock);

	wake_up_process(thread);
	wait_for_completion(&req.done);

	kfree(tmp);
	return req.err;
}

static int dev_mkdir(const char *name, umode_t mode)
{
	struct dentry *dentry;
	struct path path;
	int err;

	dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY);
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);

	err = vfs_mkdir(path.dentry->d_inode, dentry, mode);
	if (!err)
		/* mark as kernel-created inode */
		dentry->d_inode->i_private = &thread;
	done_path_create(&path, dentry);
	return err;
}

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

	/* parent directories do not exist, create them */
	path = kstrdup(nodepath, GFP_KERNEL);
	if (!path)
		return -ENOMEM;

	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);
	return err;
}

static int handle_create(const char *nodename, umode_t mode, struct device *dev)
{
	struct dentry *dentry;
	struct path path;
	int err;

	dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
	if (dentry == ERR_PTR(-ENOENT)) {
		create_path(nodename);
		dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
	}
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);

	err = vfs_mknod(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 = &thread;
	}
	done_path_create(&path, dentry);
	return err;
}

static int dev_rmdir(const char *name)
{
	struct path parent;
	struct dentry *dentry;
	int err;

	dentry = kern_path_locked(name, &parent);
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);
	if (dentry->d_inode) {
		if (dentry->d_inode->i_private == &thread)
			err = vfs_rmdir(parent.dentry->d_inode, dentry);
		else
			err = -EPERM;
	} else {
		err = -ENOENT;
	}
	dput(dentry);
	mutex_unlock(&parent.dentry->d_inode->i_mutex);
	path_put(&parent);
	return err;
}

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

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

	for (;;) {
		char *base;

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

	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 != &thread)
		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;
}

static int handle_remove(const char *nodename, struct device *dev)
{
	struct path parent;
	struct dentry *dentry;
	int deleted = 1;
	int err;

	dentry = kern_path_locked(nodename, &parent);
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);

	if (dentry->d_inode) {
		struct kstat stat;
		struct path p = {.mnt = parent.mnt, .dentry = dentry};
		err = vfs_getattr(&p, &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 = GLOBAL_ROOT_UID;
			newattrs.ia_gid = GLOBAL_ROOT_GID;
			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(parent.dentry->d_inode, dentry);
			if (!err || err == -ENOENT)
				deleted = 1;
		}
	} else {
		err = -ENOENT;
	}
	dput(dentry);
	mutex_unlock(&parent.dentry->d_inode->i_mutex);

	path_put(&parent);
	if (deleted && strchr(nodename, '/'))
		delete_path(nodename);
	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 (!thread)
		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;
}

static DECLARE_COMPLETION(setup_done);

static int handle(const char *name, umode_t mode, struct device *dev)
{
	if (mode)
		return handle_create(name, mode, dev);
	else
		return handle_remove(name, dev);
}

static int devtmpfsd(void *p)
{
	char options[] = "mode=0755";
	int *err = p;
	*err = sys_unshare(CLONE_NEWNS);
	if (*err)
		goto out;
	*err = sys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options);
	if (*err)
		goto out;
	sys_chdir("/.."); /* will traverse into overmounted root */
	sys_chroot(".");
	complete(&setup_done);
	while (1) {
		spin_lock(&req_lock);
		while (requests) {
			struct req *req = requests;
			requests = NULL;
			spin_unlock(&req_lock);
			while (req) {
				struct req *next = req->next;
				req->err = handle(req->name, req->mode, req->dev);
				complete(&req->done);
				req = next;
			}
			spin_lock(&req_lock);
		}
		__set_current_state(TASK_INTERRUPTIBLE);
		spin_unlock(&req_lock);
		schedule();
	}
	return 0;
out:
	complete(&setup_done);
	return *err;
}

/*
 * Create devtmpfs instance, driver-core devices will add their device
 * nodes here.
 */
int __init devtmpfs_init(void)
{
	int err = register_filesystem(&dev_fs_type);
	if (err) {
		printk(KERN_ERR "devtmpfs: unable to register devtmpfs "
		       "type %i\n", err);
		return err;
	}

	thread = kthread_run(devtmpfsd, &err, "kdevtmpfs");
	if (!IS_ERR(thread)) {
		wait_for_completion(&setup_done);
	} else {
		err = PTR_ERR(thread);
		thread = NULL;
	}

	if (err) {
		printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err);
		unregister_filesystem(&dev_fs_type);
		return err;
	}

	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	9	* filesystem.
02fbe5e6 PK	10	* By default, all devices are named after the name of the device,
	11	* owned by root and have a default mode of 0600. Subsystems can
	12	* 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>
e454cea2	24	#include <linux/sched.h>
5a0e3ad6	25	#include <linux/slab.h>
2780f1ff	26	#include <linux/kthread.h>
2b2af54a	27
2780f1ff	28	static struct task_struct *thread;
2b2af54a KS	29
2b2af54a KS	30	#if defined CONFIG_DEVTMPFS_MOUNT
fc14f2fe	31	static int mount_dev = 1;
2b2af54a	32	#else
fc14f2fe	33	static int mount_dev;
2b2af54a KS	34	#endif
2b2af54a KS	35
2780f1ff AV	36	static DEFINE_SPINLOCK(req_lock);
	37
	38	static struct req {
	39	struct req *next;
	40	struct completion done;
	41	int err;
	42	const char *name;
2c9ede55	43	umode_t mode; /* 0 => delete */
2780f1ff AV	44	struct device *dev;
2780f1ff AV	45	} *requests;
ed413ae6	46
2b2af54a KS	47	static int __init mount_param(char *str)
2b2af54a KS	48	{
fc14f2fe	49	mount_dev = simple_strtoul(str, NULL, 0);
2b2af54a KS	50	return 1;
	51	}
	52	__setup("devtmpfs.mount=", mount_param);
	53
fc14f2fe AV	54	static struct dentry dev_mount(struct file_system_type fs_type, int flags,
fc14f2fe AV	55	const char dev_name, void data)
2b2af54a	56	{
da5e4ef7	57	#ifdef CONFIG_TMPFS
fc14f2fe	58	return mount_single(fs_type, flags, data, shmem_fill_super);
da5e4ef7	59	#else
fc14f2fe	60	return mount_single(fs_type, flags, data, ramfs_fill_super);
da5e4ef7	61	#endif
2b2af54a KS	62	}
	63
	64	static struct file_system_type dev_fs_type = {
	65	.name = "devtmpfs",
fc14f2fe	66	.mount = dev_mount,
2b2af54a KS	67	.kill_sb = kill_litter_super,
	68	};
	69
	70	#ifdef CONFIG_BLOCK
	71	static inline int is_blockdev(struct device *dev)
	72	{
	73	return dev->class == &block_class;
	74	}
	75	#else
	76	static inline int is_blockdev(struct device *dev) { return 0; }
	77	#endif
	78
2780f1ff AV	79	int devtmpfs_create_node(struct device *dev)
	80	{
	81	const char *tmp = NULL;
	82	struct req req;
	83
	84	if (!thread)
	85	return 0;
	86
	87	req.mode = 0;
	88	req.name = device_get_devnode(dev, &req.mode, &tmp);
	89	if (!req.name)
	90	return -ENOMEM;
	91
	92	if (req.mode == 0)
	93	req.mode = 0600;
	94	if (is_blockdev(dev))
	95	req.mode \|= S_IFBLK;
	96	else
	97	req.mode \|= S_IFCHR;
	98
	99	req.dev = dev;
	100
	101	init_completion(&req.done);
	102
	103	spin_lock(&req_lock);
	104	req.next = requests;
	105	requests = &req;
	106	spin_unlock(&req_lock);
	107
	108	wake_up_process(thread);
	109	wait_for_completion(&req.done);
	110
	111	kfree(tmp);
	112
	113	return req.err;
	114	}
	115
	116	int devtmpfs_delete_node(struct device *dev)
	117	{
	118	const char *tmp = NULL;
	119	struct req req;
	120
	121	if (!thread)
	122	return 0;
	123
	124	req.name = device_get_devnode(dev, NULL, &tmp);
	125	if (!req.name)
	126	return -ENOMEM;
	127
	128	req.mode = 0;
	129	req.dev = dev;
	130
	131	init_completion(&req.done);
	132
	133	spin_lock(&req_lock);
	134	req.next = requests;
	135	requests = &req;
	136	spin_unlock(&req_lock);
	137
	138	wake_up_process(thread);
	139	wait_for_completion(&req.done);
	140
	141	kfree(tmp);
	142	return req.err;
143	}
144
fbd48a69	145	static int dev_mkdir(const char *name, umode_t mode)
2b2af54a	146	{
2b2af54a	147	struct dentry *dentry;
69753a0f	148	struct path path;
2b2af54a KS	149	int err;
2b2af54a KS	150
1ac12b4b	151	dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY);
69753a0f AV	152	if (IS_ERR(dentry))
	153	return PTR_ERR(dentry);
	154
	155	err = vfs_mkdir(path.dentry->d_inode, dentry, mode);
	156	if (!err)
	157	/* mark as kernel-created inode */
	158	dentry->d_inode->i_private = &thread;
921a1650	159	done_path_create(&path, dentry);
2b2af54a KS	160	return err;
	161	}
	162
	163	static int create_path(const char *nodepath)
	164	{
5da4e689 AV	165	char *path;
5da4e689 AV	166	char *s;
9d108d25	167	int err = 0;
2b2af54a	168
5da4e689 AV	169	/* parent directories do not exist, create them */
	170	path = kstrdup(nodepath, GFP_KERNEL);
	171	if (!path)
	172	return -ENOMEM;
	173
	174	s = path;
	175	for (;;) {
	176	s = strchr(s, '/');
	177	if (!s)
	178	break;
	179	s[0] = '\0';
	180	err = dev_mkdir(path, 0755);
	181	if (err && err != -EEXIST)
	182	break;
	183	s[0] = '/';
	184	s++;
2b2af54a	185	}
5da4e689	186	kfree(path);
2b2af54a KS	187	return err;
	188	}
	189
fbd48a69	190	static int handle_create(const char nodename, umode_t mode, struct device dev)
2b2af54a	191	{
2b2af54a	192	struct dentry *dentry;
69753a0f	193	struct path path;
2b2af54a KS	194	int err;
2b2af54a KS	195
69753a0f AV	196	dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
69753a0f AV	197	if (dentry == ERR_PTR(-ENOENT)) {
2b2af54a	198	create_path(nodename);
69753a0f	199	dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
2b2af54a	200	}
69753a0f AV	201	if (IS_ERR(dentry))
	202	return PTR_ERR(dentry);
	203
	204	err = vfs_mknod(path.dentry->d_inode,
	205	dentry, mode, dev->devt);
	206	if (!err) {
	207	struct iattr newattrs;
	208
	209	/* fixup possibly umasked mode */
	210	newattrs.ia_mode = mode;
	211	newattrs.ia_valid = ATTR_MODE;
	212	mutex_lock(&dentry->d_inode->i_mutex);
	213	notify_change(dentry, &newattrs);
	214	mutex_unlock(&dentry->d_inode->i_mutex);
	215
	216	/* mark as kernel-created inode */
	217	dentry->d_inode->i_private = &thread;
2b2af54a	218	}
921a1650	219	done_path_create(&path, dentry);
2b2af54a KS	220	return err;
	221	}
	222
	223	static int dev_rmdir(const char *name)
	224	{
79714f72	225	struct path parent;
2b2af54a KS	226	struct dentry *dentry;
	227	int err;
	228
79714f72 AV	229	dentry = kern_path_locked(name, &parent);
	230	if (IS_ERR(dentry))
	231	return PTR_ERR(dentry);
	232	if (dentry->d_inode) {
	233	if (dentry->d_inode->i_private == &thread)
	234	err = vfs_rmdir(parent.dentry->d_inode, dentry);
	235	else
	236	err = -EPERM;
2b2af54a	237	} else {
79714f72	238	err = -ENOENT;
2b2af54a	239	}
79714f72 AV	240	dput(dentry);
	241	mutex_unlock(&parent.dentry->d_inode->i_mutex);
	242	path_put(&parent);
2b2af54a KS	243	return err;
	244	}
	245
	246	static int delete_path(const char *nodepath)
	247	{
	248	const char *path;
	249	int err = 0;
	250
	251	path = kstrdup(nodepath, GFP_KERNEL);
	252	if (!path)
	253	return -ENOMEM;
	254
ed413ae6	255	for (;;) {
2b2af54a KS	256	char *base;
	257
	258	base = strrchr(path, '/');
	259	if (!base)
	260	break;
	261	base[0] = '\0';
	262	err = dev_rmdir(path);
	263	if (err)
	264	break;
	265	}
	266
	267	kfree(path);
	268	return err;
	269	}
	270
	271	static int dev_mynode(struct device dev, struct inode inode, struct kstat *stat)
	272	{
	273	/* did we create it */
2780f1ff	274	if (inode->i_private != &thread)
2b2af54a KS	275	return 0;
	276
	277	/* does the dev_t match */
	278	if (is_blockdev(dev)) {
	279	if (!S_ISBLK(stat->mode))
	280	return 0;
	281	} else {
	282	if (!S_ISCHR(stat->mode))
	283	return 0;
	284	}
	285	if (stat->rdev != dev->devt)
	286	return 0;
	287
	288	/* ours */
	289	return 1;
	290	}
	291
2780f1ff	292	static int handle_remove(const char nodename, struct device dev)
2b2af54a	293	{
79714f72	294	struct path parent;
2b2af54a	295	struct dentry *dentry;
2b2af54a KS	296	int deleted = 1;
	297	int err;
	298
79714f72 AV	299	dentry = kern_path_locked(nodename, &parent);
	300	if (IS_ERR(dentry))
	301	return PTR_ERR(dentry);
	302
	303	if (dentry->d_inode) {
	304	struct kstat stat;
3dadecce AV	305	struct path p = {.mnt = parent.mnt, .dentry = dentry};
3dadecce AV	306	err = vfs_getattr(&p, &stat);
79714f72 AV	307	if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
	308	struct iattr newattrs;
	309	/*
	310	* before unlinking this node, reset permissions
	311	* of possible references like hardlinks
	312	*/
91fa2cca EB	313	newattrs.ia_uid = GLOBAL_ROOT_UID;
91fa2cca EB	314	newattrs.ia_gid = GLOBAL_ROOT_GID;
79714f72 AV	315	newattrs.ia_mode = stat.mode & ~0777;
	316	newattrs.ia_valid =
	317	ATTR_UID\|ATTR_GID\|ATTR_MODE;
	318	mutex_lock(&dentry->d_inode->i_mutex);
	319	notify_change(dentry, &newattrs);
	320	mutex_unlock(&dentry->d_inode->i_mutex);
	321	err = vfs_unlink(parent.dentry->d_inode, dentry);
	322	if (!err \|\| err == -ENOENT)
	323	deleted = 1;
2b2af54a	324	}
2b2af54a	325	} else {
79714f72	326	err = -ENOENT;
2b2af54a	327	}
79714f72 AV	328	dput(dentry);
79714f72 AV	329	mutex_unlock(&parent.dentry->d_inode->i_mutex);
2b2af54a	330
79714f72	331	path_put(&parent);
2b2af54a KS	332	if (deleted && strchr(nodename, '/'))
2b2af54a KS	333	delete_path(nodename);
2b2af54a KS	334	return err;
	335	}
	336
	337	/*
	338	* If configured, or requested by the commandline, devtmpfs will be
	339	* auto-mounted after the kernel mounted the root filesystem.
	340	*/
073120cc	341	int devtmpfs_mount(const char *mntdir)
2b2af54a	342	{
2b2af54a KS	343	int err;
2b2af54a KS	344
fc14f2fe	345	if (!mount_dev)
2b2af54a KS	346	return 0;
2b2af54a KS	347
2780f1ff	348	if (!thread)
2b2af54a KS	349	return 0;
2b2af54a KS	350
073120cc	351	err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL);
2b2af54a KS	352	if (err)
	353	printk(KERN_INFO "devtmpfs: error mounting %i\n", err);
	354	else
	355	printk(KERN_INFO "devtmpfs: mounted\n");
2b2af54a KS	356	return err;
	357	}
	358
f9e0b159	359	static DECLARE_COMPLETION(setup_done);
2780f1ff	360
fbd48a69	361	static int handle(const char name, umode_t mode, struct device dev)
2780f1ff AV	362	{
	363	if (mode)
	364	return handle_create(name, mode, dev);
	365	else
	366	return handle_remove(name, dev);
	367	}
	368
	369	static int devtmpfsd(void *p)
	370	{
	371	char options[] = "mode=0755";
	372	int *err = p;
	373	*err = sys_unshare(CLONE_NEWNS);
	374	if (*err)
	375	goto out;
	376	*err = sys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options);
	377	if (*err)
	378	goto out;
	379	sys_chdir("/.."); /* will traverse into overmounted root */
	380	sys_chroot(".");
	381	complete(&setup_done);
	382	while (1) {
	383	spin_lock(&req_lock);
	384	while (requests) {
	385	struct req *req = requests;
	386	requests = NULL;
	387	spin_unlock(&req_lock);
	388	while (req) {
e13889ba	389	struct req *next = req->next;
2780f1ff AV	390	req->err = handle(req->name, req->mode, req->dev);
2780f1ff AV	391	complete(&req->done);
e13889ba	392	req = next;
2780f1ff AV	393	}
	394	spin_lock(&req_lock);
	395	}
65e6757b	396	__set_current_state(TASK_INTERRUPTIBLE);
2780f1ff AV	397	spin_unlock(&req_lock);
2780f1ff AV	398	schedule();
2780f1ff AV	399	}
	400	return 0;
	401	out:
	402	complete(&setup_done);
	403	return *err;
	404	}
	405
2b2af54a KS	406	/*
	407	* Create devtmpfs instance, driver-core devices will add their device
	408	* nodes here.
	409	*/
	410	int __init devtmpfs_init(void)
	411	{
2780f1ff	412	int err = register_filesystem(&dev_fs_type);
2b2af54a KS	413	if (err) {
	414	printk(KERN_ERR "devtmpfs: unable to register devtmpfs "
	415	"type %i\n", err);
	416	return err;
	417	}
	418
2780f1ff AV	419	thread = kthread_run(devtmpfsd, &err, "kdevtmpfs");
	420	if (!IS_ERR(thread)) {
	421	wait_for_completion(&setup_done);
	422	} else {
	423	err = PTR_ERR(thread);
	424	thread = NULL;
	425	}
	426
	427	if (err) {
2b2af54a KS	428	printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err);
	429	unregister_filesystem(&dev_fs_type);
	430	return err;
	431	}
2b2af54a KS	432
	433	printk(KERN_INFO "devtmpfs: initialized\n");
	434	return 0;
	435	}