fs/fuse/inode.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
   FUSE: Filesystem in Userspace
   Copyright (C) 2001-2005  Miklos Szeredi <miklos@szeredi.hu>

   This program can be distributed under the terms of the GNU GPL.
   See the file COPYING.
 */

 #include "fuse_i.h"

 #include <linux/pagemap.h>
 #include <linux/slab.h>
 #include <linux/file.h>
 #include <linux/mount.h>
 #include <linux/seq_file.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/parser.h>
 #include <linux/statfs.h>

 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
 MODULE_DESCRIPTION("Filesystem in Userspace");
 MODULE_LICENSE("GPL");

 spinlock_t fuse_lock;
 static kmem_cache_t *fuse_inode_cachep;

 #define FUSE_SUPER_MAGIC 0x65735546

 struct fuse_mount_data {
 	int fd;
 	unsigned rootmode;
 	unsigned user_id;
 	unsigned flags;
 };

 static struct inode *fuse_alloc_inode(struct super_block *sb)
 {
 	struct inode *inode;
 	struct fuse_inode *fi;

 	inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
 	if (!inode)
 		return NULL;

 	fi = get_fuse_inode(inode);
 	fi->i_time = jiffies - 1;
 	fi->nodeid = 0;
 	fi->nlookup = 0;
 	fi->forget_req = fuse_request_alloc();
 	if (!fi->forget_req) {
 		kmem_cache_free(fuse_inode_cachep, inode);
 		return NULL;
 	}

 	return inode;
 }

 static void fuse_destroy_inode(struct inode *inode)
 {
 	struct fuse_inode *fi = get_fuse_inode(inode);
 	if (fi->forget_req)
 		fuse_request_free(fi->forget_req);
 	kmem_cache_free(fuse_inode_cachep, inode);
 }

 static void fuse_read_inode(struct inode *inode)
 {
 	/* No op */
 }

 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
 		      unsigned long nodeid, u64 nlookup)
 {
 	struct fuse_forget_in *inarg = &req->misc.forget_in;
 	inarg->nlookup = nlookup;
 	req->in.h.opcode = FUSE_FORGET;
 	req->in.h.nodeid = nodeid;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(struct fuse_forget_in);
 	req->in.args[0].value = inarg;
 	request_send_noreply(fc, req);
 }

 static void fuse_clear_inode(struct inode *inode)
 {
 	if (inode->i_sb->s_flags & MS_ACTIVE) {
 		struct fuse_conn *fc = get_fuse_conn(inode);
 		struct fuse_inode *fi = get_fuse_inode(inode);
 		fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
 		fi->forget_req = NULL;
 	}
 }

 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
 {
 	if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
 		invalidate_inode_pages(inode->i_mapping);

 	inode->i_ino     = attr->ino;
 	inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
 	inode->i_nlink   = attr->nlink;
 	inode->i_uid     = attr->uid;
 	inode->i_gid     = attr->gid;
 	i_size_write(inode, attr->size);
 	inode->i_blksize = PAGE_CACHE_SIZE;
 	inode->i_blocks  = attr->blocks;
 	inode->i_atime.tv_sec   = attr->atime;
 	inode->i_atime.tv_nsec  = attr->atimensec;
 	inode->i_mtime.tv_sec   = attr->mtime;
 	inode->i_mtime.tv_nsec  = attr->mtimensec;
 	inode->i_ctime.tv_sec   = attr->ctime;
 	inode->i_ctime.tv_nsec  = attr->ctimensec;
 }

 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 {
 	inode->i_mode = attr->mode & S_IFMT;
 	i_size_write(inode, attr->size);
 	if (S_ISREG(inode->i_mode)) {
 		fuse_init_common(inode);
 		fuse_init_file_inode(inode);
 	} else if (S_ISDIR(inode->i_mode))
 		fuse_init_dir(inode);
 	else if (S_ISLNK(inode->i_mode))
 		fuse_init_symlink(inode);
 	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 		 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 		fuse_init_common(inode);
 		init_special_inode(inode, inode->i_mode,
 				   new_decode_dev(attr->rdev));
 	} else {
 		/* Don't let user create weird files */
 		inode->i_mode = S_IFREG;
 		fuse_init_common(inode);
 		fuse_init_file_inode(inode);
 	}
 }

 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 {
 	unsigned long nodeid = *(unsigned long *) _nodeidp;
 	if (get_node_id(inode) == nodeid)
 		return 1;
 	else
 		return 0;
 }

 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 {
 	unsigned long nodeid = *(unsigned long *) _nodeidp;
 	get_fuse_inode(inode)->nodeid = nodeid;
 	return 0;
 }

 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 			int generation, struct fuse_attr *attr)
 {
 	struct inode *inode;
 	struct fuse_inode *fi;
 	struct fuse_conn *fc = get_fuse_conn_super(sb);
 	int retried = 0;

  retry:
 	inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 	if (!inode)
 		return NULL;

 	if ((inode->i_state & I_NEW)) {
 		inode->i_generation = generation;
 		inode->i_data.backing_dev_info = &fc->bdi;
 		fuse_init_inode(inode, attr);
 		unlock_new_inode(inode);
 	} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 		BUG_ON(retried);
 		/* Inode has changed type, any I/O on the old should fail */
 		make_bad_inode(inode);
 		iput(inode);
 		retried = 1;
 		goto retry;
 	}

 	fi = get_fuse_inode(inode);
 	fi->nlookup ++;
 	fuse_change_attributes(inode, attr);
 	return inode;
 }

 static void fuse_put_super(struct super_block *sb)
 {
 	struct fuse_conn *fc = get_fuse_conn_super(sb);

 	down_write(&fc->sbput_sem);
 	while (!list_empty(&fc->background))
 		fuse_release_background(list_entry(fc->background.next,
 						   struct fuse_req, bg_entry));

 	spin_lock(&fuse_lock);
 	fc->mounted = 0;
 	fc->user_id = 0;
 	fc->flags = 0;
 	/* Flush all readers on this fs */
 	wake_up_all(&fc->waitq);
 	up_write(&fc->sbput_sem);
 	fuse_release_conn(fc);
 	spin_unlock(&fuse_lock);
 }

 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 {
 	stbuf->f_type    = FUSE_SUPER_MAGIC;
 	stbuf->f_bsize   = attr->bsize;
 	stbuf->f_blocks  = attr->blocks;
 	stbuf->f_bfree   = attr->bfree;
 	stbuf->f_bavail  = attr->bavail;
 	stbuf->f_files   = attr->files;
 	stbuf->f_ffree   = attr->ffree;
 	stbuf->f_namelen = attr->namelen;
 	/* fsid is left zero */
 }

 static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
 {
 	struct fuse_conn *fc = get_fuse_conn_super(sb);
 	struct fuse_req *req;
 	struct fuse_statfs_out outarg;
 	int err;

         req = fuse_get_request(fc);
 	if (!req)
 		return -ERESTARTSYS;

 	req->in.numargs = 0;
 	req->in.h.opcode = FUSE_STATFS;
 	req->out.numargs = 1;
 	req->out.args[0].size = sizeof(outarg);
 	req->out.args[0].value = &outarg;
 	request_send(fc, req);
 	err = req->out.h.error;
 	if (!err)
 		convert_fuse_statfs(buf, &outarg.st);
 	fuse_put_request(fc, req);
 	return err;
 }

 enum {
 	OPT_FD,
 	OPT_ROOTMODE,
 	OPT_USER_ID,
 	OPT_DEFAULT_PERMISSIONS,
 	OPT_ALLOW_OTHER,
 	OPT_KERNEL_CACHE,
 	OPT_ERR
 };

 static match_table_t tokens = {
 	{OPT_FD,			"fd=%u"},
 	{OPT_ROOTMODE,			"rootmode=%o"},
 	{OPT_USER_ID,			"user_id=%u"},
 	{OPT_DEFAULT_PERMISSIONS,	"default_permissions"},
 	{OPT_ALLOW_OTHER,		"allow_other"},
 	{OPT_KERNEL_CACHE,		"kernel_cache"},
 	{OPT_ERR,			NULL}
 };

 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
 {
 	char *p;
 	memset(d, 0, sizeof(struct fuse_mount_data));
 	d->fd = -1;

 	while ((p = strsep(&opt, ",")) != NULL) {
 		int token;
 		int value;
 		substring_t args[MAX_OPT_ARGS];
 		if (!*p)
 			continue;

 		token = match_token(p, tokens, args);
 		switch (token) {
 		case OPT_FD:
 			if (match_int(&args[0], &value))
 				return 0;
 			d->fd = value;
 			break;

 		case OPT_ROOTMODE:
 			if (match_octal(&args[0], &value))
 				return 0;
 			d->rootmode = value;
 			break;

 		case OPT_USER_ID:
 			if (match_int(&args[0], &value))
 				return 0;
 			d->user_id = value;
 			break;

 		case OPT_DEFAULT_PERMISSIONS:
 			d->flags |= FUSE_DEFAULT_PERMISSIONS;
 			break;

 		case OPT_ALLOW_OTHER:
 			d->flags |= FUSE_ALLOW_OTHER;
 			break;

 		case OPT_KERNEL_CACHE:
 			d->flags |= FUSE_KERNEL_CACHE;
 			break;

 		default:
 			return 0;
 		}
 	}
 	if (d->fd == -1)
 		return 0;

 	return 1;
 }

 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 {
 	struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);

 	seq_printf(m, ",user_id=%u", fc->user_id);
 	if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 		seq_puts(m, ",default_permissions");
 	if (fc->flags & FUSE_ALLOW_OTHER)
 		seq_puts(m, ",allow_other");
 	if (fc->flags & FUSE_KERNEL_CACHE)
 		seq_puts(m, ",kernel_cache");
 	return 0;
 }

 static void free_conn(struct fuse_conn *fc)
 {
 	while (!list_empty(&fc->unused_list)) {
 		struct fuse_req *req;
 		req = list_entry(fc->unused_list.next, struct fuse_req, list);
 		list_del(&req->list);
 		fuse_request_free(req);
 	}
 	kfree(fc);
 }

 /* Must be called with the fuse lock held */
 void fuse_release_conn(struct fuse_conn *fc)
 {
 	fc->count--;
 	if (!fc->count)
 		free_conn(fc);
 }

 static struct fuse_conn *new_conn(void)
 {
 	struct fuse_conn *fc;

 	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
 	if (fc != NULL) {
 		int i;
 		memset(fc, 0, sizeof(*fc));
 		init_waitqueue_head(&fc->waitq);
 		INIT_LIST_HEAD(&fc->pending);
 		INIT_LIST_HEAD(&fc->processing);
 		INIT_LIST_HEAD(&fc->unused_list);
 		INIT_LIST_HEAD(&fc->background);
 		sema_init(&fc->outstanding_sem, 0);
 		init_rwsem(&fc->sbput_sem);
 		for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
 			struct fuse_req *req = fuse_request_alloc();
 			if (!req) {
 				free_conn(fc);
 				return NULL;
 			}
 			list_add(&req->list, &fc->unused_list);
 		}
 		fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 		fc->bdi.unplug_io_fn = default_unplug_io_fn;
 		fc->reqctr = 0;
 	}
 	return fc;
 }

 static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
 {
 	struct fuse_conn *fc;

 	if (file->f_op != &fuse_dev_operations)
 		return ERR_PTR(-EINVAL);
 	fc = new_conn();
 	if (fc == NULL)
 		return ERR_PTR(-ENOMEM);
 	spin_lock(&fuse_lock);
 	if (file->private_data) {
 		free_conn(fc);
 		fc = ERR_PTR(-EINVAL);
 	} else {
 		file->private_data = fc;
 		*get_fuse_conn_super_p(sb) = fc;
 		fc->mounted = 1;
 		fc->connected = 1;
 		fc->count = 2;
 	}
 	spin_unlock(&fuse_lock);
 	return fc;
 }

 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 {
 	struct fuse_attr attr;
 	memset(&attr, 0, sizeof(attr));

 	attr.mode = mode;
 	attr.ino = FUSE_ROOT_ID;
 	return fuse_iget(sb, 1, 0, &attr);
 }

 static struct super_operations fuse_super_operations = {
 	.alloc_inode    = fuse_alloc_inode,
 	.destroy_inode  = fuse_destroy_inode,
 	.read_inode	= fuse_read_inode,
 	.clear_inode	= fuse_clear_inode,
 	.put_super	= fuse_put_super,
 	.statfs		= fuse_statfs,
 	.show_options	= fuse_show_options,
 };

 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct fuse_conn *fc;
 	struct inode *root;
 	struct fuse_mount_data d;
 	struct file *file;
 	int err;

 	if (!parse_fuse_opt((char *) data, &d))
 		return -EINVAL;

 	sb->s_blocksize = PAGE_CACHE_SIZE;
 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 	sb->s_magic = FUSE_SUPER_MAGIC;
 	sb->s_op = &fuse_super_operations;
 	sb->s_maxbytes = MAX_LFS_FILESIZE;

 	file = fget(d.fd);
 	if (!file)
 		return -EINVAL;

 	fc = get_conn(file, sb);
 	fput(file);
 	if (IS_ERR(fc))
 		return PTR_ERR(fc);

 	fc->flags = d.flags;
 	fc->user_id = d.user_id;

 	err = -ENOMEM;
 	root = get_root_inode(sb, d.rootmode);
 	if (root == NULL)
 		goto err;

 	sb->s_root = d_alloc_root(root);
 	if (!sb->s_root) {
 		iput(root);
 		goto err;
 	}
 	fuse_send_init(fc);
 	return 0;

  err:
 	spin_lock(&fuse_lock);
 	fuse_release_conn(fc);
 	spin_unlock(&fuse_lock);
 	return err;
 }

 static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
 				       int flags, const char *dev_name,
 				       void *raw_data)
 {
 	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
 }

 static struct file_system_type fuse_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "fuse",
 	.get_sb		= fuse_get_sb,
 	.kill_sb	= kill_anon_super,
 };

 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
 				 unsigned long flags)
 {
 	struct inode * inode = foo;

 	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 	    SLAB_CTOR_CONSTRUCTOR)
 		inode_init_once(inode);
 }

 static int __init fuse_fs_init(void)
 {
 	int err;

 	err = register_filesystem(&fuse_fs_type);
 	if (err)
 		printk("fuse: failed to register filesystem\n");
 	else {
 		fuse_inode_cachep = kmem_cache_create("fuse_inode",
 						      sizeof(struct fuse_inode),
 						      0, SLAB_HWCACHE_ALIGN,
 						      fuse_inode_init_once, NULL);
 		if (!fuse_inode_cachep) {
 			unregister_filesystem(&fuse_fs_type);
 			err = -ENOMEM;
 		}
 	}

 	return err;
 }

 static void fuse_fs_cleanup(void)
 {
 	unregister_filesystem(&fuse_fs_type);
 	kmem_cache_destroy(fuse_inode_cachep);
 }

 static int __init fuse_init(void)
 {
 	int res;

 	printk("fuse init (API version %i.%i)\n",
 	       FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);

 	spin_lock_init(&fuse_lock);
 	res = fuse_fs_init();
 	if (res)
 		goto err;

 	res = fuse_dev_init();
 	if (res)
 		goto err_fs_cleanup;

 	return 0;

  err_fs_cleanup:
 	fuse_fs_cleanup();
  err:
 	return res;
 }

 static void __exit fuse_exit(void)
 {
 	printk(KERN_DEBUG "fuse exit\n");

 	fuse_fs_cleanup();
 	fuse_dev_cleanup();
 }

 module_init(fuse_init);
 module_exit(fuse_exit);
	/*
	FUSE: Filesystem in Userspace
	Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>

	This program can be distributed under the terms of the GNU GPL.
	See the file COPYING.
	*/

	#include "fuse_i.h"

	#include <linux/pagemap.h>
	#include <linux/slab.h>
	#include <linux/file.h>
	#include <linux/mount.h>
	#include <linux/seq_file.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/parser.h>
	#include <linux/statfs.h>

	MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
	MODULE_DESCRIPTION("Filesystem in Userspace");
	MODULE_LICENSE("GPL");

	spinlock_t fuse_lock;
	static kmem_cache_t *fuse_inode_cachep;

	#define FUSE_SUPER_MAGIC 0x65735546

	struct fuse_mount_data {
	int fd;
	unsigned rootmode;
	unsigned user_id;
	unsigned flags;
	};

	static struct inode fuse_alloc_inode(struct super_block sb)
	{
	struct inode *inode;
	struct fuse_inode *fi;

	inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
	if (!inode)
	return NULL;

	fi = get_fuse_inode(inode);
	fi->i_time = jiffies - 1;
	fi->nodeid = 0;
	fi->nlookup = 0;
	fi->forget_req = fuse_request_alloc();
	if (!fi->forget_req) {
	kmem_cache_free(fuse_inode_cachep, inode);
	return NULL;
	}

	return inode;
	}

	static void fuse_destroy_inode(struct inode *inode)
	{
	struct fuse_inode *fi = get_fuse_inode(inode);
	if (fi->forget_req)
	fuse_request_free(fi->forget_req);
	kmem_cache_free(fuse_inode_cachep, inode);
	}

	static void fuse_read_inode(struct inode *inode)
	{
	/* No op */
	}

	void fuse_send_forget(struct fuse_conn fc, struct fuse_req req,
	unsigned long nodeid, u64 nlookup)
	{
	struct fuse_forget_in *inarg = &req->misc.forget_in;
	inarg->nlookup = nlookup;
	req->in.h.opcode = FUSE_FORGET;
	req->in.h.nodeid = nodeid;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_forget_in);
	req->in.args[0].value = inarg;
	request_send_noreply(fc, req);
	}

	static void fuse_clear_inode(struct inode *inode)
	{
	if (inode->i_sb->s_flags & MS_ACTIVE) {
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
	fi->forget_req = NULL;
	}
	}

	void fuse_change_attributes(struct inode inode, struct fuse_attr attr)
	{
	if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
	invalidate_inode_pages(inode->i_mapping);

	inode->i_ino = attr->ino;
	inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
	inode->i_nlink = attr->nlink;
	inode->i_uid = attr->uid;
	inode->i_gid = attr->gid;
	i_size_write(inode, attr->size);
	inode->i_blksize = PAGE_CACHE_SIZE;
	inode->i_blocks = attr->blocks;
	inode->i_atime.tv_sec = attr->atime;
	inode->i_atime.tv_nsec = attr->atimensec;
	inode->i_mtime.tv_sec = attr->mtime;
	inode->i_mtime.tv_nsec = attr->mtimensec;
	inode->i_ctime.tv_sec = attr->ctime;
	inode->i_ctime.tv_nsec = attr->ctimensec;
	}

	static void fuse_init_inode(struct inode inode, struct fuse_attr attr)
	{
	inode->i_mode = attr->mode & S_IFMT;
	i_size_write(inode, attr->size);
	if (S_ISREG(inode->i_mode)) {
	fuse_init_common(inode);
	fuse_init_file_inode(inode);
	} else if (S_ISDIR(inode->i_mode))
	fuse_init_dir(inode);
	else if (S_ISLNK(inode->i_mode))
	fuse_init_symlink(inode);
	else if (S_ISCHR(inode->i_mode) \|\| S_ISBLK(inode->i_mode) \|\|
	S_ISFIFO(inode->i_mode) \|\| S_ISSOCK(inode->i_mode)) {
	fuse_init_common(inode);
	init_special_inode(inode, inode->i_mode,
	new_decode_dev(attr->rdev));
	} else {
	/* Don't let user create weird files */
	inode->i_mode = S_IFREG;
	fuse_init_common(inode);
	fuse_init_file_inode(inode);
	}
	}

	static int fuse_inode_eq(struct inode inode, void _nodeidp)
	{
	unsigned long nodeid = (unsigned long ) _nodeidp;
	if (get_node_id(inode) == nodeid)
	return 1;
	else
	return 0;
	}

	static int fuse_inode_set(struct inode inode, void _nodeidp)
	{
	unsigned long nodeid = (unsigned long ) _nodeidp;
	get_fuse_inode(inode)->nodeid = nodeid;
	return 0;
	}

	struct inode fuse_iget(struct super_block sb, unsigned long nodeid,
	int generation, struct fuse_attr *attr)
	{
	struct inode *inode;
	struct fuse_inode *fi;
	struct fuse_conn *fc = get_fuse_conn_super(sb);
	int retried = 0;

	retry:
	inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
	if (!inode)
	return NULL;

	if ((inode->i_state & I_NEW)) {
	inode->i_generation = generation;
	inode->i_data.backing_dev_info = &fc->bdi;
	fuse_init_inode(inode, attr);
	unlock_new_inode(inode);
	} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
	BUG_ON(retried);
	/* Inode has changed type, any I/O on the old should fail */
	make_bad_inode(inode);
	iput(inode);
	retried = 1;
	goto retry;
	}

	fi = get_fuse_inode(inode);
	fi->nlookup ++;
	fuse_change_attributes(inode, attr);
	return inode;
	}

	static void fuse_put_super(struct super_block *sb)
	{
	struct fuse_conn *fc = get_fuse_conn_super(sb);

	down_write(&fc->sbput_sem);
	while (!list_empty(&fc->background))
	fuse_release_background(list_entry(fc->background.next,
	struct fuse_req, bg_entry));

	spin_lock(&fuse_lock);
	fc->mounted = 0;
	fc->user_id = 0;
	fc->flags = 0;
	/* Flush all readers on this fs */
	wake_up_all(&fc->waitq);
	up_write(&fc->sbput_sem);
	fuse_release_conn(fc);
	spin_unlock(&fuse_lock);
	}

	static void convert_fuse_statfs(struct kstatfs stbuf, struct fuse_kstatfs attr)
	{
	stbuf->f_type = FUSE_SUPER_MAGIC;
	stbuf->f_bsize = attr->bsize;
	stbuf->f_blocks = attr->blocks;
	stbuf->f_bfree = attr->bfree;
	stbuf->f_bavail = attr->bavail;
	stbuf->f_files = attr->files;
	stbuf->f_ffree = attr->ffree;
	stbuf->f_namelen = attr->namelen;
	/* fsid is left zero */
	}

	static int fuse_statfs(struct super_block sb, struct kstatfs buf)
	{
	struct fuse_conn *fc = get_fuse_conn_super(sb);
	struct fuse_req *req;
	struct fuse_statfs_out outarg;
	int err;

	req = fuse_get_request(fc);
	if (!req)
	return -ERESTARTSYS;

	req->in.numargs = 0;
	req->in.h.opcode = FUSE_STATFS;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(outarg);
	req->out.args[0].value = &outarg;
	request_send(fc, req);
	err = req->out.h.error;
	if (!err)
	convert_fuse_statfs(buf, &outarg.st);
	fuse_put_request(fc, req);
	return err;
	}

	enum {
	OPT_FD,
	OPT_ROOTMODE,
	OPT_USER_ID,
	OPT_DEFAULT_PERMISSIONS,
	OPT_ALLOW_OTHER,
	OPT_KERNEL_CACHE,
	OPT_ERR
	};

	static match_table_t tokens = {
	{OPT_FD, "fd=%u"},
	{OPT_ROOTMODE, "rootmode=%o"},
	{OPT_USER_ID, "user_id=%u"},
	{OPT_DEFAULT_PERMISSIONS, "default_permissions"},
	{OPT_ALLOW_OTHER, "allow_other"},
	{OPT_KERNEL_CACHE, "kernel_cache"},
	{OPT_ERR, NULL}
	};

	static int parse_fuse_opt(char opt, struct fuse_mount_data d)
	{
	char *p;
	memset(d, 0, sizeof(struct fuse_mount_data));
	d->fd = -1;

	while ((p = strsep(&opt, ",")) != NULL) {
	int token;
	int value;
	substring_t args[MAX_OPT_ARGS];
	if (!*p)
	continue;

	token = match_token(p, tokens, args);
	switch (token) {
	case OPT_FD:
	if (match_int(&args[0], &value))
	return 0;
	d->fd = value;
	break;

	case OPT_ROOTMODE:
	if (match_octal(&args[0], &value))
	return 0;
	d->rootmode = value;
	break;

	case OPT_USER_ID:
	if (match_int(&args[0], &value))
	return 0;
	d->user_id = value;
	break;

	case OPT_DEFAULT_PERMISSIONS:
	d->flags \|= FUSE_DEFAULT_PERMISSIONS;
	break;

	case OPT_ALLOW_OTHER:
	d->flags \|= FUSE_ALLOW_OTHER;
	break;

	case OPT_KERNEL_CACHE:
	d->flags \|= FUSE_KERNEL_CACHE;
	break;

	default:
	return 0;
	}
	}
	if (d->fd == -1)
	return 0;

	return 1;
	}

	static int fuse_show_options(struct seq_file m, struct vfsmount mnt)
	{
	struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);

	seq_printf(m, ",user_id=%u", fc->user_id);
	if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
	seq_puts(m, ",default_permissions");
	if (fc->flags & FUSE_ALLOW_OTHER)
	seq_puts(m, ",allow_other");
	if (fc->flags & FUSE_KERNEL_CACHE)
	seq_puts(m, ",kernel_cache");
	return 0;
	}

	static void free_conn(struct fuse_conn *fc)
	{
	while (!list_empty(&fc->unused_list)) {
	struct fuse_req *req;
	req = list_entry(fc->unused_list.next, struct fuse_req, list);
	list_del(&req->list);
	fuse_request_free(req);
	}
	kfree(fc);
	}

	/* Must be called with the fuse lock held */
	void fuse_release_conn(struct fuse_conn *fc)
	{
	fc->count--;
	if (!fc->count)
	free_conn(fc);
	}

	static struct fuse_conn *new_conn(void)
	{
	struct fuse_conn *fc;

	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
	if (fc != NULL) {
	int i;
	memset(fc, 0, sizeof(*fc));
	init_waitqueue_head(&fc->waitq);
	INIT_LIST_HEAD(&fc->pending);
	INIT_LIST_HEAD(&fc->processing);
	INIT_LIST_HEAD(&fc->unused_list);
	INIT_LIST_HEAD(&fc->background);
	sema_init(&fc->outstanding_sem, 0);
	init_rwsem(&fc->sbput_sem);
	for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
	struct fuse_req *req = fuse_request_alloc();
	if (!req) {
	free_conn(fc);
	return NULL;
	}
	list_add(&req->list, &fc->unused_list);
	}
	fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
	fc->bdi.unplug_io_fn = default_unplug_io_fn;
	fc->reqctr = 0;
	}
	return fc;
	}

	static struct fuse_conn get_conn(struct file file, struct super_block *sb)
	{
	struct fuse_conn *fc;

	if (file->f_op != &fuse_dev_operations)
	return ERR_PTR(-EINVAL);
	fc = new_conn();
	if (fc == NULL)
	return ERR_PTR(-ENOMEM);
	spin_lock(&fuse_lock);
	if (file->private_data) {
	free_conn(fc);
	fc = ERR_PTR(-EINVAL);
	} else {
	file->private_data = fc;
	*get_fuse_conn_super_p(sb) = fc;
	fc->mounted = 1;
	fc->connected = 1;
	fc->count = 2;
	}
	spin_unlock(&fuse_lock);
	return fc;
	}

	static struct inode get_root_inode(struct super_block sb, unsigned mode)
	{
	struct fuse_attr attr;
	memset(&attr, 0, sizeof(attr));

	attr.mode = mode;
	attr.ino = FUSE_ROOT_ID;
	return fuse_iget(sb, 1, 0, &attr);
	}

	static struct super_operations fuse_super_operations = {
	.alloc_inode = fuse_alloc_inode,
	.destroy_inode = fuse_destroy_inode,
	.read_inode = fuse_read_inode,
	.clear_inode = fuse_clear_inode,
	.put_super = fuse_put_super,
	.statfs = fuse_statfs,
	.show_options = fuse_show_options,
	};

	static int fuse_fill_super(struct super_block sb, void data, int silent)
	{
	struct fuse_conn *fc;
	struct inode *root;
	struct fuse_mount_data d;
	struct file *file;
	int err;

	if (!parse_fuse_opt((char *) data, &d))
	return -EINVAL;

	sb->s_blocksize = PAGE_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	sb->s_magic = FUSE_SUPER_MAGIC;
	sb->s_op = &fuse_super_operations;
	sb->s_maxbytes = MAX_LFS_FILESIZE;

	file = fget(d.fd);
	if (!file)
	return -EINVAL;

	fc = get_conn(file, sb);
	fput(file);
	if (IS_ERR(fc))
	return PTR_ERR(fc);

	fc->flags = d.flags;
	fc->user_id = d.user_id;

	err = -ENOMEM;
	root = get_root_inode(sb, d.rootmode);
	if (root == NULL)
	goto err;

	sb->s_root = d_alloc_root(root);
	if (!sb->s_root) {
	iput(root);
	goto err;
	}
	fuse_send_init(fc);
	return 0;

	err:
	spin_lock(&fuse_lock);
	fuse_release_conn(fc);
	spin_unlock(&fuse_lock);
	return err;
	}

	static struct super_block fuse_get_sb(struct file_system_type fs_type,
	int flags, const char *dev_name,
	void *raw_data)
	{
	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
	}

	static struct file_system_type fuse_fs_type = {
	.owner = THIS_MODULE,
	.name = "fuse",
	.get_sb = fuse_get_sb,
	.kill_sb = kill_anon_super,
	};

	static void fuse_inode_init_once(void foo, kmem_cache_t cachep,
	unsigned long flags)
	{
	struct inode * inode = foo;

	if ((flags & (SLAB_CTOR_VERIFY\|SLAB_CTOR_CONSTRUCTOR)) ==
	SLAB_CTOR_CONSTRUCTOR)
	inode_init_once(inode);
	}

	static int __init fuse_fs_init(void)
	{
	int err;

	err = register_filesystem(&fuse_fs_type);
	if (err)
	printk("fuse: failed to register filesystem\n");
	else {
	fuse_inode_cachep = kmem_cache_create("fuse_inode",
	sizeof(struct fuse_inode),
	0, SLAB_HWCACHE_ALIGN,
	fuse_inode_init_once, NULL);
	if (!fuse_inode_cachep) {
	unregister_filesystem(&fuse_fs_type);
	err = -ENOMEM;
	}
	}

	return err;
	}

	static void fuse_fs_cleanup(void)
	{
	unregister_filesystem(&fuse_fs_type);
	kmem_cache_destroy(fuse_inode_cachep);
	}

	static int __init fuse_init(void)
	{
	int res;

	printk("fuse init (API version %i.%i)\n",
	FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);

	spin_lock_init(&fuse_lock);
	res = fuse_fs_init();
	if (res)
	goto err;

	res = fuse_dev_init();
	if (res)
	goto err_fs_cleanup;

	return 0;

	err_fs_cleanup:
	fuse_fs_cleanup();
	err:
	return res;
	}

	static void __exit fuse_exit(void)
	{
	printk(KERN_DEBUG "fuse exit\n");

	fuse_fs_cleanup();
	fuse_dev_cleanup();
	}

	module_init(fuse_init);
	module_exit(fuse_exit);