[linux-block.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->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)
{
	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, 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);
	} 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)
{
	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);

	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);
}

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;
9e6268db	54	fi->nlookup = 0;
e5e5558e MS	55	fi->forget_req = fuse_request_alloc();
	56	if (!fi->forget_req) {
	57	kmem_cache_free(fuse_inode_cachep, inode);
	58	return NULL;
	59	}
d8a5ba45 MS	60
	61	return inode;
	62	}
	63
	64	static void fuse_destroy_inode(struct inode *inode)
	65	{
e5e5558e MS	66	struct fuse_inode *fi = get_fuse_inode(inode);
	67	if (fi->forget_req)
	68	fuse_request_free(fi->forget_req);
d8a5ba45 MS	69	kmem_cache_free(fuse_inode_cachep, inode);
	70	}
	71
	72	static void fuse_read_inode(struct inode *inode)
	73	{
	74	/* No op */
	75	}
	76
e5e5558e	77	void fuse_send_forget(struct fuse_conn fc, struct fuse_req req,
9e6268db	78	unsigned long nodeid, u64 nlookup)
e5e5558e MS	79	{
e5e5558e MS	80	struct fuse_forget_in *inarg = &req->misc.forget_in;
9e6268db	81	inarg->nlookup = nlookup;
e5e5558e MS	82	req->in.h.opcode = FUSE_FORGET;
	83	req->in.h.nodeid = nodeid;
	84	req->in.numargs = 1;
	85	req->in.args[0].size = sizeof(struct fuse_forget_in);
	86	req->in.args[0].value = inarg;
	87	request_send_noreply(fc, req);
	88	}
	89
d8a5ba45 MS	90	static void fuse_clear_inode(struct inode *inode)
d8a5ba45 MS	91	{
e5e5558e MS	92	struct fuse_conn *fc = get_fuse_conn(inode);
	93	if (fc) {
	94	struct fuse_inode *fi = get_fuse_inode(inode);
9e6268db	95	fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
e5e5558e MS	96	fi->forget_req = NULL;
e5e5558e MS	97	}
d8a5ba45 MS	98	}
	99
	100	void fuse_change_attributes(struct inode inode, struct fuse_attr attr)
	101	{
	102	if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
	103	invalidate_inode_pages(inode->i_mapping);
	104
	105	inode->i_ino = attr->ino;
	106	inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
	107	inode->i_nlink = attr->nlink;
	108	inode->i_uid = attr->uid;
	109	inode->i_gid = attr->gid;
	110	i_size_write(inode, attr->size);
	111	inode->i_blksize = PAGE_CACHE_SIZE;
	112	inode->i_blocks = attr->blocks;
	113	inode->i_atime.tv_sec = attr->atime;
	114	inode->i_atime.tv_nsec = attr->atimensec;
	115	inode->i_mtime.tv_sec = attr->mtime;
	116	inode->i_mtime.tv_nsec = attr->mtimensec;
	117	inode->i_ctime.tv_sec = attr->ctime;
	118	inode->i_ctime.tv_nsec = attr->ctimensec;
	119	}
	120
	121	static void fuse_init_inode(struct inode inode, struct fuse_attr attr)
	122	{
	123	inode->i_mode = attr->mode & S_IFMT;
	124	i_size_write(inode, attr->size);
e5e5558e MS	125	if (S_ISREG(inode->i_mode)) {
	126	fuse_init_common(inode);
	127	} else if (S_ISDIR(inode->i_mode))
	128	fuse_init_dir(inode);
	129	else if (S_ISLNK(inode->i_mode))
	130	fuse_init_symlink(inode);
	131	else if (S_ISCHR(inode->i_mode) \|\| S_ISBLK(inode->i_mode) \|\|
	132	S_ISFIFO(inode->i_mode) \|\| S_ISSOCK(inode->i_mode)) {
	133	fuse_init_common(inode);
	134	init_special_inode(inode, inode->i_mode,
	135	new_decode_dev(attr->rdev));
	136	} else {
	137	/* Don't let user create weird files */
	138	inode->i_mode = S_IFREG;
	139	fuse_init_common(inode);
	140	}
d8a5ba45 MS	141	}
	142
	143	static int fuse_inode_eq(struct inode inode, void _nodeidp)
	144	{
	145	unsigned long nodeid = (unsigned long ) _nodeidp;
	146	if (get_node_id(inode) == nodeid)
	147	return 1;
	148	else
	149	return 0;
	150	}
	151
	152	static int fuse_inode_set(struct inode inode, void _nodeidp)
	153	{
	154	unsigned long nodeid = (unsigned long ) _nodeidp;
	155	get_fuse_inode(inode)->nodeid = nodeid;
	156	return 0;
	157	}
	158
	159	struct inode fuse_iget(struct super_block sb, unsigned long nodeid,
9e6268db	160	int generation, struct fuse_attr *attr)
d8a5ba45 MS	161	{
d8a5ba45 MS	162	struct inode *inode;
9e6268db	163	struct fuse_inode *fi;
d8a5ba45 MS	164	struct fuse_conn *fc = get_fuse_conn_super(sb);
	165	int retried = 0;
	166
	167	retry:
	168	inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
	169	if (!inode)
	170	return NULL;
	171
	172	if ((inode->i_state & I_NEW)) {
	173	inode->i_generation = generation;
	174	inode->i_data.backing_dev_info = &fc->bdi;
	175	fuse_init_inode(inode, attr);
	176	unlock_new_inode(inode);
	177	} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
	178	BUG_ON(retried);
	179	/* Inode has changed type, any I/O on the old should fail */
	180	make_bad_inode(inode);
	181	iput(inode);
	182	retried = 1;
	183	goto retry;
	184	}
	185
9e6268db MS	186	fi = get_fuse_inode(inode);
9e6268db MS	187	fi->nlookup ++;
d8a5ba45	188	fuse_change_attributes(inode, attr);
d8a5ba45 MS	189	return inode;
	190	}
	191
	192	static void fuse_put_super(struct super_block *sb)
	193	{
	194	struct fuse_conn *fc = get_fuse_conn_super(sb);
	195
	196	spin_lock(&fuse_lock);
	197	mount_count --;
	198	fc->sb = NULL;
	199	fc->user_id = 0;
334f485d MS	200	/* Flush all readers on this fs */
334f485d MS	201	wake_up_all(&fc->waitq);
d8a5ba45 MS	202	fuse_release_conn(fc);
	203	*get_fuse_conn_super_p(sb) = NULL;
	204	spin_unlock(&fuse_lock);
	205	}
	206
e5e5558e MS	207	static void convert_fuse_statfs(struct kstatfs stbuf, struct fuse_kstatfs attr)
	208	{
	209	stbuf->f_type = FUSE_SUPER_MAGIC;
	210	stbuf->f_bsize = attr->bsize;
	211	stbuf->f_blocks = attr->blocks;
	212	stbuf->f_bfree = attr->bfree;
	213	stbuf->f_bavail = attr->bavail;
	214	stbuf->f_files = attr->files;
	215	stbuf->f_ffree = attr->ffree;
	216	stbuf->f_namelen = attr->namelen;
	217	/* fsid is left zero */
	218	}
	219
	220	static int fuse_statfs(struct super_block sb, struct kstatfs buf)
	221	{
	222	struct fuse_conn *fc = get_fuse_conn_super(sb);
	223	struct fuse_req *req;
	224	struct fuse_statfs_out outarg;
	225	int err;
	226
	227	req = fuse_get_request(fc);
	228	if (!req)
	229	return -ERESTARTSYS;
	230
	231	req->in.numargs = 0;
	232	req->in.h.opcode = FUSE_STATFS;
	233	req->out.numargs = 1;
	234	req->out.args[0].size = sizeof(outarg);
	235	req->out.args[0].value = &outarg;
	236	request_send(fc, req);
	237	err = req->out.h.error;
	238	if (!err)
	239	convert_fuse_statfs(buf, &outarg.st);
	240	fuse_put_request(fc, req);
	241	return err;
	242	}
	243
d8a5ba45 MS	244	enum {
	245	OPT_FD,
	246	OPT_ROOTMODE,
	247	OPT_USER_ID,
	248	OPT_DEFAULT_PERMISSIONS,
	249	OPT_ALLOW_OTHER,
	250	OPT_ALLOW_ROOT,
	251	OPT_KERNEL_CACHE,
	252	OPT_ERR
	253	};
	254
	255	static match_table_t tokens = {
	256	{OPT_FD, "fd=%u"},
	257	{OPT_ROOTMODE, "rootmode=%o"},
	258	{OPT_USER_ID, "user_id=%u"},
	259	{OPT_DEFAULT_PERMISSIONS, "default_permissions"},
	260	{OPT_ALLOW_OTHER, "allow_other"},
	261	{OPT_ALLOW_ROOT, "allow_root"},
	262	{OPT_KERNEL_CACHE, "kernel_cache"},
	263	{OPT_ERR, NULL}
	264	};
	265
	266	static int parse_fuse_opt(char opt, struct fuse_mount_data d)
	267	{
	268	char *p;
	269	memset(d, 0, sizeof(struct fuse_mount_data));
	270	d->fd = -1;
	271
	272	while ((p = strsep(&opt, ",")) != NULL) {
	273	int token;
	274	int value;
	275	substring_t args[MAX_OPT_ARGS];
	276	if (!*p)
	277	continue;
	278
	279	token = match_token(p, tokens, args);
	280	switch (token) {
	281	case OPT_FD:
	282	if (match_int(&args[0], &value))
	283	return 0;
	284	d->fd = value;
	285	break;
	286
	287	case OPT_ROOTMODE:
	288	if (match_octal(&args[0], &value))
	289	return 0;
	290	d->rootmode = value;
	291	break;
	292
	293	case OPT_USER_ID:
	294	if (match_int(&args[0], &value))
	295	return 0;
	296	d->user_id = value;
	297	break;
	298
	299	default:
	300	return 0;
	301	}
	302	}
	303	if (d->fd == -1)
	304	return 0;
	305
	306	return 1;
	307	}
308
309	static int fuse_show_options(struct seq_file m, struct vfsmount mnt)
310	{
311	struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
312
313	seq_printf(m, ",user_id=%u", fc->user_id);
314	return 0;
315	}
316
334f485d	317	static void free_conn(struct fuse_conn *fc)
d8a5ba45	318	{
334f485d MS	319	while (!list_empty(&fc->unused_list)) {
	320	struct fuse_req *req;
	321	req = list_entry(fc->unused_list.next, struct fuse_req, list);
	322	list_del(&req->list);
	323	fuse_request_free(req);
	324	}
d8a5ba45 MS	325	kfree(fc);
	326	}
	327
334f485d MS	328	/* Must be called with the fuse lock held */
	329	void fuse_release_conn(struct fuse_conn *fc)
	330	{
	331	if (!fc->sb && !fc->file)
	332	free_conn(fc);
	333	}
	334
d8a5ba45 MS	335	static struct fuse_conn *new_conn(void)
	336	{
	337	struct fuse_conn *fc;
	338
	339	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
	340	if (fc != NULL) {
334f485d	341	int i;
d8a5ba45 MS	342	memset(fc, 0, sizeof(*fc));
d8a5ba45 MS	343	fc->sb = NULL;
334f485d	344	fc->file = NULL;
d8a5ba45	345	fc->user_id = 0;
334f485d MS	346	init_waitqueue_head(&fc->waitq);
	347	INIT_LIST_HEAD(&fc->pending);
	348	INIT_LIST_HEAD(&fc->processing);
	349	INIT_LIST_HEAD(&fc->unused_list);
	350	sema_init(&fc->outstanding_sem, 0);
	351	for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
	352	struct fuse_req *req = fuse_request_alloc();
	353	if (!req) {
	354	free_conn(fc);
	355	return NULL;
	356	}
	357	list_add(&req->list, &fc->unused_list);
	358	}
d8a5ba45 MS	359	fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
d8a5ba45 MS	360	fc->bdi.unplug_io_fn = default_unplug_io_fn;
334f485d	361	fc->reqctr = 0;
d8a5ba45 MS	362	}
	363	return fc;
	364	}
	365
	366	static struct fuse_conn get_conn(struct file file, struct super_block *sb)
	367	{
	368	struct fuse_conn *fc;
	369
334f485d MS	370	if (file->f_op != &fuse_dev_operations)
334f485d MS	371	return ERR_PTR(-EINVAL);
d8a5ba45 MS	372	fc = new_conn();
d8a5ba45 MS	373	if (fc == NULL)
334f485d	374	return ERR_PTR(-ENOMEM);
d8a5ba45	375	spin_lock(&fuse_lock);
334f485d MS	376	if (file->private_data) {
	377	free_conn(fc);
	378	fc = ERR_PTR(-EINVAL);
	379	} else {
	380	file->private_data = fc;
	381	fc->sb = sb;
	382	fc->file = file;
	383	}
d8a5ba45 MS	384	spin_unlock(&fuse_lock);
	385	return fc;
	386	}
	387
	388	static struct inode get_root_inode(struct super_block sb, unsigned mode)
	389	{
	390	struct fuse_attr attr;
	391	memset(&attr, 0, sizeof(attr));
	392
	393	attr.mode = mode;
	394	attr.ino = FUSE_ROOT_ID;
9e6268db	395	return fuse_iget(sb, 1, 0, &attr);
d8a5ba45 MS	396	}
	397
	398	static struct super_operations fuse_super_operations = {
	399	.alloc_inode = fuse_alloc_inode,
	400	.destroy_inode = fuse_destroy_inode,
	401	.read_inode = fuse_read_inode,
	402	.clear_inode = fuse_clear_inode,
	403	.put_super = fuse_put_super,
e5e5558e	404	.statfs = fuse_statfs,
d8a5ba45 MS	405	.show_options = fuse_show_options,
	406	};
	407
	408	static int inc_mount_count(void)
	409	{
	410	int success = 0;
	411	spin_lock(&fuse_lock);
	412	mount_count ++;
	413	if (mount_max == -1 \|\| mount_count <= mount_max)
	414	success = 1;
	415	spin_unlock(&fuse_lock);
	416	return success;
	417	}
	418
	419	static int fuse_fill_super(struct super_block sb, void data, int silent)
	420	{
	421	struct fuse_conn *fc;
	422	struct inode *root;
	423	struct fuse_mount_data d;
	424	struct file *file;
	425	int err;
	426
	427	if (!parse_fuse_opt((char *) data, &d))
	428	return -EINVAL;
	429
	430	sb->s_blocksize = PAGE_CACHE_SIZE;
	431	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	432	sb->s_magic = FUSE_SUPER_MAGIC;
	433	sb->s_op = &fuse_super_operations;
	434	sb->s_maxbytes = MAX_LFS_FILESIZE;
	435
	436	file = fget(d.fd);
	437	if (!file)
	438	return -EINVAL;
	439
	440	fc = get_conn(file, sb);
	441	fput(file);
334f485d MS	442	if (IS_ERR(fc))
334f485d MS	443	return PTR_ERR(fc);
d8a5ba45 MS	444
	445	fc->user_id = d.user_id;
	446
	447	*get_fuse_conn_super_p(sb) = fc;
	448
	449	err = -ENFILE;
	450	if (!inc_mount_count() && current->uid != 0)
	451	goto err;
	452
	453	err = -ENOMEM;
	454	root = get_root_inode(sb, d.rootmode);
	455	if (root == NULL)
	456	goto err;
	457
	458	sb->s_root = d_alloc_root(root);
	459	if (!sb->s_root) {
	460	iput(root);
	461	goto err;
	462	}
334f485d	463	fuse_send_init(fc);
d8a5ba45 MS	464	return 0;
	465
	466	err:
	467	spin_lock(&fuse_lock);
	468	mount_count --;
	469	fc->sb = NULL;
	470	fuse_release_conn(fc);
	471	spin_unlock(&fuse_lock);
	472	*get_fuse_conn_super_p(sb) = NULL;
	473	return err;
	474	}
	475
	476	static struct super_block fuse_get_sb(struct file_system_type fs_type,
	477	int flags, const char *dev_name,
	478	void *raw_data)
	479	{
	480	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
	481	}
	482
	483	static struct file_system_type fuse_fs_type = {
	484	.owner = THIS_MODULE,
	485	.name = "fuse",
	486	.get_sb = fuse_get_sb,
	487	.kill_sb = kill_anon_super,
	488	};
	489
	490	static void fuse_inode_init_once(void foo, kmem_cache_t cachep,
	491	unsigned long flags)
	492	{
	493	struct inode * inode = foo;
	494
	495	if ((flags & (SLAB_CTOR_VERIFY\|SLAB_CTOR_CONSTRUCTOR)) ==
	496	SLAB_CTOR_CONSTRUCTOR)
	497	inode_init_once(inode);
	498	}
	499
	500	static int __init fuse_fs_init(void)
	501	{
	502	int err;
	503
	504	err = register_filesystem(&fuse_fs_type);
	505	if (err)
	506	printk("fuse: failed to register filesystem\n");
	507	else {
	508	fuse_inode_cachep = kmem_cache_create("fuse_inode",
	509	sizeof(struct fuse_inode),
	510	0, SLAB_HWCACHE_ALIGN,
	511	fuse_inode_init_once, NULL);
	512	if (!fuse_inode_cachep) {
	513	unregister_filesystem(&fuse_fs_type);
	514	err = -ENOMEM;
	515	}
	516	}
	517
	518	return err;
	519	}
	520
	521	static void fuse_fs_cleanup(void)
	522	{
	523	unregister_filesystem(&fuse_fs_type);
	524	kmem_cache_destroy(fuse_inode_cachep);
	525	}
	526
	527	static int __init fuse_init(void)
528	{
529	int res;
530
531	printk("fuse init (API version %i.%i)\n",
532	FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
533
534	spin_lock_init(&fuse_lock);
535	res = fuse_fs_init();
536	if (res)
537	goto err;
538
334f485d MS	539	res = fuse_dev_init();
	540	if (res)
	541	goto err_fs_cleanup;
	542
d8a5ba45 MS	543	return 0;
d8a5ba45 MS	544
334f485d MS	545	err_fs_cleanup:
334f485d MS	546	fuse_fs_cleanup();
d8a5ba45 MS	547	err:
	548	return res;
	549	}
	550
	551	static void __exit fuse_exit(void)
	552	{
	553	printk(KERN_DEBUG "fuse exit\n");
	554
	555	fuse_fs_cleanup();
334f485d	556	fuse_dev_cleanup();
d8a5ba45 MS	557	}
	558
	559	module_init(fuse_init);
	560	module_exit(fuse_exit);