[mirror_ubuntu-artful-kernel.git] / fs / fuse / inode.c

/*
  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/moduleparam.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;
static int mount_count;

static int mount_max = 1000;
module_param(mount_max, int, 0644);
MODULE_PARM_DESC(mount_max, "Maximum number of FUSE mounts allowed, if -1 then unlimited (default: 1000)");

#define FUSE_SUPER_MAGIC 0x65735546

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

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->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, int version)
{
	struct fuse_forget_in *inarg = &req->misc.forget_in;
	inarg->version = version;
	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)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	if (fc) {
		struct fuse_inode *fi = get_fuse_inode(inode);
		fuse_send_forget(fc, fi->forget_req, fi->nodeid, inode->i_version);
		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);
	} 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);
	}
}

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, int version)
{
	struct inode *inode;
	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;
	}

	fuse_change_attributes(inode, attr);
	inode->i_version = version;
	return inode;
}

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

	spin_lock(&fuse_lock);
	mount_count --;
	fc->sb = NULL;
	fc->user_id = 0;
	/* Flush all readers on this fs */
	wake_up_all(&fc->waitq);
	fuse_release_conn(fc);
	*get_fuse_conn_super_p(sb) = NULL;
	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_ALLOW_ROOT,
	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_ALLOW_ROOT,		"allow_root"},
	{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;

		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);
	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)
{
	if (!fc->sb && !fc->file)
		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));
		fc->sb = NULL;
		fc->file = NULL;
		fc->user_id = 0;
		init_waitqueue_head(&fc->waitq);
		INIT_LIST_HEAD(&fc->pending);
		INIT_LIST_HEAD(&fc->processing);
		INIT_LIST_HEAD(&fc->unused_list);
		sema_init(&fc->outstanding_sem, 0);
		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;
		fc->sb = sb;
		fc->file = file;
	}
	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, 0);
}

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 inc_mount_count(void)
{
	int success = 0;
	spin_lock(&fuse_lock);
	mount_count ++;
	if (mount_max == -1 || mount_count <= mount_max)
		success = 1;
	spin_unlock(&fuse_lock);
	return success;
}

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->user_id = d.user_id;

	*get_fuse_conn_super_p(sb) = fc;

	err = -ENFILE;
	if (!inc_mount_count() && current->uid != 0)
		goto err;

	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);
	mount_count --;
	fc->sb = NULL;
	fuse_release_conn(fc);
	spin_unlock(&fuse_lock);
	*get_fuse_conn_super_p(sb) = NULL;
	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);
Commit	Line	Data
d8a5ba45 MS	1	/*
	2	FUSE: Filesystem in Userspace
	3	Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
	4
	5	This program can be distributed under the terms of the GNU GPL.
	6	See the file COPYING.
	7	*/
	8
	9	#include "fuse_i.h"
	10
	11	#include <linux/pagemap.h>
	12	#include <linux/slab.h>
	13	#include <linux/file.h>
	14	#include <linux/mount.h>
	15	#include <linux/seq_file.h>
	16	#include <linux/init.h>
	17	#include <linux/module.h>
	18	#include <linux/moduleparam.h>
	19	#include <linux/parser.h>
	20	#include <linux/statfs.h>
	21
	22	MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
	23	MODULE_DESCRIPTION("Filesystem in Userspace");
	24	MODULE_LICENSE("GPL");
	25
	26	spinlock_t fuse_lock;
	27	static kmem_cache_t *fuse_inode_cachep;
	28	static int mount_count;
	29
	30	static int mount_max = 1000;
	31	module_param(mount_max, int, 0644);
	32	MODULE_PARM_DESC(mount_max, "Maximum number of FUSE mounts allowed, if -1 then unlimited (default: 1000)");
	33
	34	#define FUSE_SUPER_MAGIC 0x65735546
	35
	36	struct fuse_mount_data {
	37	int fd;
	38	unsigned rootmode;
	39	unsigned user_id;
	40	};
	41
	42	static struct inode fuse_alloc_inode(struct super_block sb)
	43	{
	44	struct inode *inode;
	45	struct fuse_inode *fi;
	46
	47	inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
	48	if (!inode)
	49	return NULL;
	50
	51	fi = get_fuse_inode(inode);
	52	fi->i_time = jiffies - 1;
	53	fi->nodeid = 0;
e5e5558e MS	54	fi->forget_req = fuse_request_alloc();
	55	if (!fi->forget_req) {
	56	kmem_cache_free(fuse_inode_cachep, inode);
	57	return NULL;
	58	}
d8a5ba45 MS	59
	60	return inode;
	61	}
	62
	63	static void fuse_destroy_inode(struct inode *inode)
	64	{
e5e5558e MS	65	struct fuse_inode *fi = get_fuse_inode(inode);
	66	if (fi->forget_req)
	67	fuse_request_free(fi->forget_req);
d8a5ba45 MS	68	kmem_cache_free(fuse_inode_cachep, inode);
	69	}
	70
	71	static void fuse_read_inode(struct inode *inode)
	72	{
	73	/* No op */
	74	}
	75
e5e5558e MS	76	void fuse_send_forget(struct fuse_conn fc, struct fuse_req req,
	77	unsigned long nodeid, int version)
	78	{
	79	struct fuse_forget_in *inarg = &req->misc.forget_in;
	80	inarg->version = version;
	81	req->in.h.opcode = FUSE_FORGET;
	82	req->in.h.nodeid = nodeid;
	83	req->in.numargs = 1;
	84	req->in.args[0].size = sizeof(struct fuse_forget_in);
	85	req->in.args[0].value = inarg;
	86	request_send_noreply(fc, req);
	87	}
	88
d8a5ba45 MS	89	static void fuse_clear_inode(struct inode *inode)
d8a5ba45 MS	90	{
e5e5558e MS	91	struct fuse_conn *fc = get_fuse_conn(inode);
	92	if (fc) {
	93	struct fuse_inode *fi = get_fuse_inode(inode);
	94	fuse_send_forget(fc, fi->forget_req, fi->nodeid, inode->i_version);
	95	fi->forget_req = NULL;
	96	}
d8a5ba45 MS	97	}
	98
	99	void fuse_change_attributes(struct inode inode, struct fuse_attr attr)
	100	{
	101	if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
	102	invalidate_inode_pages(inode->i_mapping);
	103
	104	inode->i_ino = attr->ino;
	105	inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
	106	inode->i_nlink = attr->nlink;
	107	inode->i_uid = attr->uid;
	108	inode->i_gid = attr->gid;
	109	i_size_write(inode, attr->size);
	110	inode->i_blksize = PAGE_CACHE_SIZE;
	111	inode->i_blocks = attr->blocks;
	112	inode->i_atime.tv_sec = attr->atime;
	113	inode->i_atime.tv_nsec = attr->atimensec;
	114	inode->i_mtime.tv_sec = attr->mtime;
	115	inode->i_mtime.tv_nsec = attr->mtimensec;
	116	inode->i_ctime.tv_sec = attr->ctime;
	117	inode->i_ctime.tv_nsec = attr->ctimensec;
	118	}
	119
	120	static void fuse_init_inode(struct inode inode, struct fuse_attr attr)
	121	{
	122	inode->i_mode = attr->mode & S_IFMT;
	123	i_size_write(inode, attr->size);
e5e5558e MS	124	if (S_ISREG(inode->i_mode)) {
	125	fuse_init_common(inode);
	126	} else if (S_ISDIR(inode->i_mode))
	127	fuse_init_dir(inode);
	128	else if (S_ISLNK(inode->i_mode))
	129	fuse_init_symlink(inode);
	130	else if (S_ISCHR(inode->i_mode) \|\| S_ISBLK(inode->i_mode) \|\|
	131	S_ISFIFO(inode->i_mode) \|\| S_ISSOCK(inode->i_mode)) {
	132	fuse_init_common(inode);
	133	init_special_inode(inode, inode->i_mode,
	134	new_decode_dev(attr->rdev));
	135	} else {
	136	/* Don't let user create weird files */
	137	inode->i_mode = S_IFREG;
	138	fuse_init_common(inode);
	139	}
d8a5ba45 MS	140	}
	141
	142	static int fuse_inode_eq(struct inode inode, void _nodeidp)
	143	{
	144	unsigned long nodeid = (unsigned long ) _nodeidp;
	145	if (get_node_id(inode) == nodeid)
	146	return 1;
	147	else
	148	return 0;
	149	}
	150
	151	static int fuse_inode_set(struct inode inode, void _nodeidp)
	152	{
	153	unsigned long nodeid = (unsigned long ) _nodeidp;
	154	get_fuse_inode(inode)->nodeid = nodeid;
	155	return 0;
	156	}
	157
	158	struct inode fuse_iget(struct super_block sb, unsigned long nodeid,
	159	int generation, struct fuse_attr *attr, int version)
	160	{
	161	struct inode *inode;
	162	struct fuse_conn *fc = get_fuse_conn_super(sb);
	163	int retried = 0;
	164
	165	retry:
	166	inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
	167	if (!inode)
	168	return NULL;
	169
	170	if ((inode->i_state & I_NEW)) {
	171	inode->i_generation = generation;
	172	inode->i_data.backing_dev_info = &fc->bdi;
	173	fuse_init_inode(inode, attr);
	174	unlock_new_inode(inode);
	175	} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
	176	BUG_ON(retried);
	177	/* Inode has changed type, any I/O on the old should fail */
	178	make_bad_inode(inode);
	179	iput(inode);
	180	retried = 1;
	181	goto retry;
	182	}
	183
	184	fuse_change_attributes(inode, attr);
	185	inode->i_version = version;
	186	return inode;
	187	}
	188
	189	static void fuse_put_super(struct super_block *sb)
	190	{
	191	struct fuse_conn *fc = get_fuse_conn_super(sb);
	192
	193	spin_lock(&fuse_lock);
	194	mount_count --;
	195	fc->sb = NULL;
	196	fc->user_id = 0;
334f485d MS	197	/* Flush all readers on this fs */
334f485d MS	198	wake_up_all(&fc->waitq);
d8a5ba45 MS	199	fuse_release_conn(fc);
	200	*get_fuse_conn_super_p(sb) = NULL;
	201	spin_unlock(&fuse_lock);
	202	}
	203
e5e5558e MS	204	static void convert_fuse_statfs(struct kstatfs stbuf, struct fuse_kstatfs attr)
	205	{
	206	stbuf->f_type = FUSE_SUPER_MAGIC;
	207	stbuf->f_bsize = attr->bsize;
	208	stbuf->f_blocks = attr->blocks;
	209	stbuf->f_bfree = attr->bfree;
	210	stbuf->f_bavail = attr->bavail;
	211	stbuf->f_files = attr->files;
	212	stbuf->f_ffree = attr->ffree;
	213	stbuf->f_namelen = attr->namelen;
	214	/* fsid is left zero */
	215	}
	216
	217	static int fuse_statfs(struct super_block sb, struct kstatfs buf)
	218	{
	219	struct fuse_conn *fc = get_fuse_conn_super(sb);
	220	struct fuse_req *req;
	221	struct fuse_statfs_out outarg;
	222	int err;
	223
	224	req = fuse_get_request(fc);
	225	if (!req)
	226	return -ERESTARTSYS;
	227
	228	req->in.numargs = 0;
	229	req->in.h.opcode = FUSE_STATFS;
	230	req->out.numargs = 1;
	231	req->out.args[0].size = sizeof(outarg);
	232	req->out.args[0].value = &outarg;
	233	request_send(fc, req);
	234	err = req->out.h.error;
	235	if (!err)
	236	convert_fuse_statfs(buf, &outarg.st);
	237	fuse_put_request(fc, req);
	238	return err;
	239	}
	240
d8a5ba45 MS	241	enum {
	242	OPT_FD,
	243	OPT_ROOTMODE,
	244	OPT_USER_ID,
	245	OPT_DEFAULT_PERMISSIONS,
	246	OPT_ALLOW_OTHER,
	247	OPT_ALLOW_ROOT,
	248	OPT_KERNEL_CACHE,
	249	OPT_ERR
	250	};
	251
	252	static match_table_t tokens = {
	253	{OPT_FD, "fd=%u"},
	254	{OPT_ROOTMODE, "rootmode=%o"},
	255	{OPT_USER_ID, "user_id=%u"},
	256	{OPT_DEFAULT_PERMISSIONS, "default_permissions"},
	257	{OPT_ALLOW_OTHER, "allow_other"},
	258	{OPT_ALLOW_ROOT, "allow_root"},
	259	{OPT_KERNEL_CACHE, "kernel_cache"},
	260	{OPT_ERR, NULL}
	261	};
	262
	263	static int parse_fuse_opt(char opt, struct fuse_mount_data d)
	264	{
	265	char *p;
	266	memset(d, 0, sizeof(struct fuse_mount_data));
	267	d->fd = -1;
	268
	269	while ((p = strsep(&opt, ",")) != NULL) {
	270	int token;
	271	int value;
	272	substring_t args[MAX_OPT_ARGS];
	273	if (!*p)
	274	continue;
	275
	276	token = match_token(p, tokens, args);
	277	switch (token) {
	278	case OPT_FD:
	279	if (match_int(&args[0], &value))
	280	return 0;
	281	d->fd = value;
	282	break;
	283
	284	case OPT_ROOTMODE:
	285	if (match_octal(&args[0], &value))
	286	return 0;
	287	d->rootmode = value;
	288	break;
	289
	290	case OPT_USER_ID:
	291	if (match_int(&args[0], &value))
	292	return 0;
	293	d->user_id = value;
	294	break;
	295
	296	default:
	297	return 0;
	298	}
	299	}
	300	if (d->fd == -1)
	301	return 0;
	302
	303	return 1;
	304	}
305
306	static int fuse_show_options(struct seq_file m, struct vfsmount mnt)
307	{
308	struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
309
310	seq_printf(m, ",user_id=%u", fc->user_id);
311	return 0;
312	}
313
334f485d	314	static void free_conn(struct fuse_conn *fc)
d8a5ba45	315	{
334f485d MS	316	while (!list_empty(&fc->unused_list)) {
	317	struct fuse_req *req;
	318	req = list_entry(fc->unused_list.next, struct fuse_req, list);
	319	list_del(&req->list);
	320	fuse_request_free(req);
	321	}
d8a5ba45 MS	322	kfree(fc);
	323	}
	324
334f485d MS	325	/* Must be called with the fuse lock held */
	326	void fuse_release_conn(struct fuse_conn *fc)
	327	{
	328	if (!fc->sb && !fc->file)
	329	free_conn(fc);
	330	}
	331
d8a5ba45 MS	332	static struct fuse_conn *new_conn(void)
	333	{
	334	struct fuse_conn *fc;
	335
	336	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
	337	if (fc != NULL) {
334f485d	338	int i;
d8a5ba45 MS	339	memset(fc, 0, sizeof(*fc));
d8a5ba45 MS	340	fc->sb = NULL;
334f485d	341	fc->file = NULL;
d8a5ba45	342	fc->user_id = 0;
334f485d MS	343	init_waitqueue_head(&fc->waitq);
	344	INIT_LIST_HEAD(&fc->pending);
	345	INIT_LIST_HEAD(&fc->processing);
	346	INIT_LIST_HEAD(&fc->unused_list);
	347	sema_init(&fc->outstanding_sem, 0);
	348	for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
	349	struct fuse_req *req = fuse_request_alloc();
	350	if (!req) {
	351	free_conn(fc);
	352	return NULL;
	353	}
	354	list_add(&req->list, &fc->unused_list);
	355	}
d8a5ba45 MS	356	fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
d8a5ba45 MS	357	fc->bdi.unplug_io_fn = default_unplug_io_fn;
334f485d	358	fc->reqctr = 0;
d8a5ba45 MS	359	}
	360	return fc;
	361	}
	362
	363	static struct fuse_conn get_conn(struct file file, struct super_block *sb)
	364	{
	365	struct fuse_conn *fc;
	366
334f485d MS	367	if (file->f_op != &fuse_dev_operations)
334f485d MS	368	return ERR_PTR(-EINVAL);
d8a5ba45 MS	369	fc = new_conn();
d8a5ba45 MS	370	if (fc == NULL)
334f485d	371	return ERR_PTR(-ENOMEM);
d8a5ba45	372	spin_lock(&fuse_lock);
334f485d MS	373	if (file->private_data) {
	374	free_conn(fc);
	375	fc = ERR_PTR(-EINVAL);
	376	} else {
	377	file->private_data = fc;
	378	fc->sb = sb;
	379	fc->file = file;
	380	}
d8a5ba45 MS	381	spin_unlock(&fuse_lock);
	382	return fc;
	383	}
	384
	385	static struct inode get_root_inode(struct super_block sb, unsigned mode)
	386	{
	387	struct fuse_attr attr;
	388	memset(&attr, 0, sizeof(attr));
	389
	390	attr.mode = mode;
	391	attr.ino = FUSE_ROOT_ID;
	392	return fuse_iget(sb, 1, 0, &attr, 0);
	393	}
	394
	395	static struct super_operations fuse_super_operations = {
	396	.alloc_inode = fuse_alloc_inode,
	397	.destroy_inode = fuse_destroy_inode,
	398	.read_inode = fuse_read_inode,
	399	.clear_inode = fuse_clear_inode,
	400	.put_super = fuse_put_super,
e5e5558e	401	.statfs = fuse_statfs,
d8a5ba45 MS	402	.show_options = fuse_show_options,
	403	};
	404
	405	static int inc_mount_count(void)
	406	{
	407	int success = 0;
	408	spin_lock(&fuse_lock);
	409	mount_count ++;
	410	if (mount_max == -1 \|\| mount_count <= mount_max)
	411	success = 1;
	412	spin_unlock(&fuse_lock);
	413	return success;
	414	}
	415
	416	static int fuse_fill_super(struct super_block sb, void data, int silent)
	417	{
	418	struct fuse_conn *fc;
	419	struct inode *root;
	420	struct fuse_mount_data d;
	421	struct file *file;
	422	int err;
	423
	424	if (!parse_fuse_opt((char *) data, &d))
	425	return -EINVAL;
	426
	427	sb->s_blocksize = PAGE_CACHE_SIZE;
	428	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	429	sb->s_magic = FUSE_SUPER_MAGIC;
	430	sb->s_op = &fuse_super_operations;
	431	sb->s_maxbytes = MAX_LFS_FILESIZE;
	432
	433	file = fget(d.fd);
	434	if (!file)
	435	return -EINVAL;
	436
	437	fc = get_conn(file, sb);
	438	fput(file);
334f485d MS	439	if (IS_ERR(fc))
334f485d MS	440	return PTR_ERR(fc);
d8a5ba45 MS	441
	442	fc->user_id = d.user_id;
	443
	444	*get_fuse_conn_super_p(sb) = fc;
	445
	446	err = -ENFILE;
	447	if (!inc_mount_count() && current->uid != 0)
	448	goto err;
	449
	450	err = -ENOMEM;
	451	root = get_root_inode(sb, d.rootmode);
	452	if (root == NULL)
	453	goto err;
	454
	455	sb->s_root = d_alloc_root(root);
	456	if (!sb->s_root) {
	457	iput(root);
	458	goto err;
	459	}
334f485d	460	fuse_send_init(fc);
d8a5ba45 MS	461	return 0;
	462
	463	err:
	464	spin_lock(&fuse_lock);
	465	mount_count --;
	466	fc->sb = NULL;
	467	fuse_release_conn(fc);
	468	spin_unlock(&fuse_lock);
	469	*get_fuse_conn_super_p(sb) = NULL;
	470	return err;
	471	}
	472
	473	static struct super_block fuse_get_sb(struct file_system_type fs_type,
	474	int flags, const char *dev_name,
	475	void *raw_data)
	476	{
	477	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
	478	}
	479
	480	static struct file_system_type fuse_fs_type = {
	481	.owner = THIS_MODULE,
	482	.name = "fuse",
	483	.get_sb = fuse_get_sb,
	484	.kill_sb = kill_anon_super,
	485	};
	486
	487	static void fuse_inode_init_once(void foo, kmem_cache_t cachep,
	488	unsigned long flags)
	489	{
	490	struct inode * inode = foo;
	491
	492	if ((flags & (SLAB_CTOR_VERIFY\|SLAB_CTOR_CONSTRUCTOR)) ==
	493	SLAB_CTOR_CONSTRUCTOR)
	494	inode_init_once(inode);
	495	}
	496
	497	static int __init fuse_fs_init(void)
	498	{
	499	int err;
	500
	501	err = register_filesystem(&fuse_fs_type);
	502	if (err)
	503	printk("fuse: failed to register filesystem\n");
	504	else {
	505	fuse_inode_cachep = kmem_cache_create("fuse_inode",
	506	sizeof(struct fuse_inode),
	507	0, SLAB_HWCACHE_ALIGN,
	508	fuse_inode_init_once, NULL);
	509	if (!fuse_inode_cachep) {
	510	unregister_filesystem(&fuse_fs_type);
	511	err = -ENOMEM;
	512	}
	513	}
	514
	515	return err;
	516	}
	517
	518	static void fuse_fs_cleanup(void)
	519	{
	520	unregister_filesystem(&fuse_fs_type);
	521	kmem_cache_destroy(fuse_inode_cachep);
	522	}
	523
	524	static int __init fuse_init(void)
525	{
526	int res;
527
528	printk("fuse init (API version %i.%i)\n",
529	FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
530
531	spin_lock_init(&fuse_lock);
532	res = fuse_fs_init();
533	if (res)
534	goto err;
535
334f485d MS	536	res = fuse_dev_init();
	537	if (res)
	538	goto err_fs_cleanup;
	539
d8a5ba45 MS	540	return 0;
d8a5ba45 MS	541
334f485d MS	542	err_fs_cleanup:
334f485d MS	543	fuse_fs_cleanup();
d8a5ba45 MS	544	err:
	545	return res;
	546	}
	547
	548	static void __exit fuse_exit(void)
	549	{
	550	printk(KERN_DEBUG "fuse exit\n");
	551
	552	fuse_fs_cleanup();
334f485d	553	fuse_dev_cleanup();
d8a5ba45 MS	554	}
	555
	556	module_init(fuse_init);
	557	module_exit(fuse_exit);