inode.c 24.7 KB
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/*
  FUSE: Filesystem in Userspace
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  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
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  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/seq_file.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/parser.h>
#include <linux/statfs.h>
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#include <linux/random.h>
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#include <linux/sched.h>
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#include <linux/exportfs.h>
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MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
MODULE_DESCRIPTION("Filesystem in Userspace");
MODULE_LICENSE("GPL");

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static struct kmem_cache *fuse_inode_cachep;
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struct list_head fuse_conn_list;
DEFINE_MUTEX(fuse_mutex);
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#define FUSE_SUPER_MAGIC 0x65735546

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#define FUSE_DEFAULT_BLKSIZE 512

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struct fuse_mount_data {
	int fd;
	unsigned rootmode;
	unsigned user_id;
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	unsigned group_id;
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	unsigned fd_present:1;
	unsigned rootmode_present:1;
	unsigned user_id_present:1;
	unsigned group_id_present:1;
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	unsigned flags;
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	unsigned max_read;
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	unsigned blksize;
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};

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

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

	fi = get_fuse_inode(inode);
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	fi->i_time = 0;
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	fi->nodeid = 0;
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	fi->nlookup = 0;
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	fi->attr_version = 0;
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	fi->writectr = 0;
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	INIT_LIST_HEAD(&fi->write_files);
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	INIT_LIST_HEAD(&fi->queued_writes);
	INIT_LIST_HEAD(&fi->writepages);
	init_waitqueue_head(&fi->page_waitq);
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	fi->forget_req = fuse_request_alloc();
	if (!fi->forget_req) {
		kmem_cache_free(fuse_inode_cachep, inode);
		return NULL;
	}
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	return inode;
}

static void fuse_destroy_inode(struct inode *inode)
{
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	struct fuse_inode *fi = get_fuse_inode(inode);
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	BUG_ON(!list_empty(&fi->write_files));
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	BUG_ON(!list_empty(&fi->queued_writes));
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	if (fi->forget_req)
		fuse_request_free(fi->forget_req);
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	kmem_cache_free(fuse_inode_cachep, inode);
}

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void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
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		      u64 nodeid, u64 nlookup)
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{
	struct fuse_forget_in *inarg = &req->misc.forget_in;
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	inarg->nlookup = nlookup;
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	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;
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	fuse_request_send_noreply(fc, req);
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}

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

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static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
{
	if (*flags & MS_MANDLOCK)
		return -EINVAL;

	return 0;
}

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void fuse_truncate(struct address_space *mapping, loff_t offset)
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{
	/* See vmtruncate() */
	unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
	truncate_inode_pages(mapping, offset);
	unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
}

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void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
				   u64 attr_valid)
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{
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	struct fuse_conn *fc = get_fuse_conn(inode);
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	struct fuse_inode *fi = get_fuse_inode(inode);
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	fi->attr_version = ++fc->attr_version;
	fi->i_time = attr_valid;

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	inode->i_ino     = attr->ino;
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	inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
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	inode->i_nlink   = attr->nlink;
	inode->i_uid     = attr->uid;
	inode->i_gid     = attr->gid;
	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;
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	if (attr->blksize != 0)
		inode->i_blkbits = ilog2(attr->blksize);
	else
		inode->i_blkbits = inode->i_sb->s_blocksize_bits;

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	/*
	 * Don't set the sticky bit in i_mode, unless we want the VFS
	 * to check permissions.  This prevents failures due to the
	 * check in may_delete().
	 */
	fi->orig_i_mode = inode->i_mode;
	if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
		inode->i_mode &= ~S_ISVTX;
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}

void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
			    u64 attr_valid, u64 attr_version)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	loff_t oldsize;

	spin_lock(&fc->lock);
	if (attr_version != 0 && fi->attr_version > attr_version) {
		spin_unlock(&fc->lock);
		return;
	}

	fuse_change_attributes_common(inode, attr, attr_valid);
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	oldsize = inode->i_size;
	i_size_write(inode, attr->size);
	spin_unlock(&fc->lock);

	if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
		if (attr->size < oldsize)
			fuse_truncate(inode->i_mapping, attr->size);
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		invalidate_inode_pages2(inode->i_mapping);
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	}
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}

static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
{
	inode->i_mode = attr->mode & S_IFMT;
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	inode->i_size = attr->size;
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	if (S_ISREG(inode->i_mode)) {
		fuse_init_common(inode);
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		fuse_init_file_inode(inode);
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	} 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));
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	} else
		BUG();
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}

static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
{
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	u64 nodeid = *(u64 *) _nodeidp;
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	if (get_node_id(inode) == nodeid)
		return 1;
	else
		return 0;
}

static int fuse_inode_set(struct inode *inode, void *_nodeidp)
{
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	u64 nodeid = *(u64 *) _nodeidp;
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	get_fuse_inode(inode)->nodeid = nodeid;
	return 0;
}

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struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
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			int generation, struct fuse_attr *attr,
			u64 attr_valid, u64 attr_version)
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{
	struct inode *inode;
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	struct fuse_inode *fi;
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	struct fuse_conn *fc = get_fuse_conn_super(sb);

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

	if ((inode->i_state & I_NEW)) {
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		inode->i_flags |= S_NOATIME|S_NOCMTIME;
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		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) {
		/* Inode has changed type, any I/O on the old should fail */
		make_bad_inode(inode);
		iput(inode);
		goto retry;
	}

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	fi = get_fuse_inode(inode);
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	spin_lock(&fc->lock);
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	fi->nlookup++;
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	spin_unlock(&fc->lock);
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	fuse_change_attributes(inode, attr, attr_valid, attr_version);

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	return inode;
}

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static void fuse_umount_begin(struct super_block *sb)
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{
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	fuse_abort_conn(get_fuse_conn_super(sb));
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}

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static void fuse_send_destroy(struct fuse_conn *fc)
{
	struct fuse_req *req = fc->destroy_req;
	if (req && fc->conn_init) {
		fc->destroy_req = NULL;
		req->in.h.opcode = FUSE_DESTROY;
		req->force = 1;
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		fuse_request_send(fc, req);
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		fuse_put_request(fc, req);
	}
}

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

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	fuse_send_destroy(fc);
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	spin_lock(&fc->lock);
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	fc->connected = 0;
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	fc->blocked = 0;
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	spin_unlock(&fc->lock);
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	/* Flush all readers on this fs */
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	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
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	wake_up_all(&fc->waitq);
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	wake_up_all(&fc->blocked_waitq);
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	wake_up_all(&fc->reserved_req_waitq);
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	mutex_lock(&fuse_mutex);
	list_del(&fc->entry);
	fuse_ctl_remove_conn(fc);
	mutex_unlock(&fuse_mutex);
	fuse_conn_put(fc);
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}

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static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
{
	stbuf->f_type    = FUSE_SUPER_MAGIC;
	stbuf->f_bsize   = attr->bsize;
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	stbuf->f_frsize  = attr->frsize;
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	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 */
}

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

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	if (!fuse_allow_task(fc, current)) {
		buf->f_type = FUSE_SUPER_MAGIC;
		return 0;
	}

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	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
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	memset(&outarg, 0, sizeof(outarg));
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	req->in.numargs = 0;
	req->in.h.opcode = FUSE_STATFS;
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	req->in.h.nodeid = get_node_id(dentry->d_inode);
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	req->out.numargs = 1;
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	req->out.args[0].size =
		fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
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	req->out.args[0].value = &outarg;
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	fuse_request_send(fc, req);
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	err = req->out.h.error;
	if (!err)
		convert_fuse_statfs(buf, &outarg.st);
	fuse_put_request(fc, req);
	return err;
}

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enum {
	OPT_FD,
	OPT_ROOTMODE,
	OPT_USER_ID,
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	OPT_GROUP_ID,
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	OPT_DEFAULT_PERMISSIONS,
	OPT_ALLOW_OTHER,
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	OPT_MAX_READ,
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	OPT_BLKSIZE,
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	OPT_ERR
};

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static const match_table_t tokens = {
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	{OPT_FD,			"fd=%u"},
	{OPT_ROOTMODE,			"rootmode=%o"},
	{OPT_USER_ID,			"user_id=%u"},
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	{OPT_GROUP_ID,			"group_id=%u"},
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	{OPT_DEFAULT_PERMISSIONS,	"default_permissions"},
	{OPT_ALLOW_OTHER,		"allow_other"},
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	{OPT_MAX_READ,			"max_read=%u"},
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	{OPT_BLKSIZE,			"blksize=%u"},
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	{OPT_ERR,			NULL}
};

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static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
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{
	char *p;
	memset(d, 0, sizeof(struct fuse_mount_data));
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	d->max_read = ~0;
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	d->blksize = FUSE_DEFAULT_BLKSIZE;
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	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;
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			d->fd_present = 1;
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			break;

		case OPT_ROOTMODE:
			if (match_octal(&args[0], &value))
				return 0;
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			if (!fuse_valid_type(value))
				return 0;
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			d->rootmode = value;
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			d->rootmode_present = 1;
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			break;

		case OPT_USER_ID:
			if (match_int(&args[0], &value))
				return 0;
			d->user_id = value;
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			d->user_id_present = 1;
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			break;

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		case OPT_GROUP_ID:
			if (match_int(&args[0], &value))
				return 0;
			d->group_id = value;
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			d->group_id_present = 1;
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			break;

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

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

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

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		case OPT_BLKSIZE:
			if (!is_bdev || match_int(&args[0], &value))
				return 0;
			d->blksize = value;
			break;

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		default:
			return 0;
		}
	}
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	if (!d->fd_present || !d->rootmode_present ||
	    !d->user_id_present || !d->group_id_present)
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		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);
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	seq_printf(m, ",group_id=%u", fc->group_id);
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	if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
		seq_puts(m, ",default_permissions");
	if (fc->flags & FUSE_ALLOW_OTHER)
		seq_puts(m, ",allow_other");
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	if (fc->max_read != ~0)
		seq_printf(m, ",max_read=%u", fc->max_read);
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	if (mnt->mnt_sb->s_bdev &&
	    mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
		seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
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	return 0;
}

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int fuse_conn_init(struct fuse_conn *fc, struct super_block *sb)
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{
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	int err;
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	memset(fc, 0, sizeof(*fc));
	spin_lock_init(&fc->lock);
	mutex_init(&fc->inst_mutex);
	atomic_set(&fc->count, 1);
	init_waitqueue_head(&fc->waitq);
	init_waitqueue_head(&fc->blocked_waitq);
	init_waitqueue_head(&fc->reserved_req_waitq);
	INIT_LIST_HEAD(&fc->pending);
	INIT_LIST_HEAD(&fc->processing);
	INIT_LIST_HEAD(&fc->io);
	INIT_LIST_HEAD(&fc->interrupts);
	INIT_LIST_HEAD(&fc->bg_queue);
	INIT_LIST_HEAD(&fc->entry);
	atomic_set(&fc->num_waiting, 0);
	fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
	fc->bdi.unplug_io_fn = default_unplug_io_fn;
	/* fuse does it's own writeback accounting */
	fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
	fc->khctr = 0;
	fc->polled_files = RB_ROOT;
	fc->dev = sb->s_dev;
	err = bdi_init(&fc->bdi);
	if (err)
		goto error_mutex_destroy;
	if (sb->s_bdev) {
		err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
				   MAJOR(fc->dev), MINOR(fc->dev));
	} else {
		err = bdi_register_dev(&fc->bdi, fc->dev);
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	}
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	if (err)
		goto error_bdi_destroy;
	/*
	 * For a single fuse filesystem use max 1% of dirty +
	 * writeback threshold.
	 *
	 * This gives about 1M of write buffer for memory maps on a
	 * machine with 1G and 10% dirty_ratio, which should be more
	 * than enough.
	 *
	 * Privileged users can raise it by writing to
	 *
	 *    /sys/class/bdi/<bdi>/max_ratio
	 */
	bdi_set_max_ratio(&fc->bdi, 1);
	fc->reqctr = 0;
	fc->blocked = 1;
	fc->attr_version = 1;
	get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
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	return 0;

 error_bdi_destroy:
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	bdi_destroy(&fc->bdi);
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 error_mutex_destroy:
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	mutex_destroy(&fc->inst_mutex);
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	return err;
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}
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EXPORT_SYMBOL_GPL(fuse_conn_init);
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void fuse_conn_put(struct fuse_conn *fc)
{
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	if (atomic_dec_and_test(&fc->count)) {
532 533
		if (fc->destroy_req)
			fuse_request_free(fc->destroy_req);
534
		mutex_destroy(&fc->inst_mutex);
P
Peter Zijlstra 已提交
535
		bdi_destroy(&fc->bdi);
T
Tejun Heo 已提交
536
		fc->release(fc);
537
	}
538 539 540 541 542 543 544 545
}

struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
{
	atomic_inc(&fc->count);
	return fc;
}

546
static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
M
Miklos Szeredi 已提交
547 548 549 550 551 552
{
	struct fuse_attr attr;
	memset(&attr, 0, sizeof(attr));

	attr.mode = mode;
	attr.ino = FUSE_ROOT_ID;
553
	attr.nlink = 1;
554
	return fuse_iget(sb, 1, 0, &attr, 0, 0);
M
Miklos Szeredi 已提交
555 556
}

M
Miklos Szeredi 已提交
557
struct fuse_inode_handle {
M
Miklos Szeredi 已提交
558 559 560 561 562 563 564
	u64 nodeid;
	u32 generation;
};

static struct dentry *fuse_get_dentry(struct super_block *sb,
				      struct fuse_inode_handle *handle)
{
565
	struct fuse_conn *fc = get_fuse_conn_super(sb);
M
Miklos Szeredi 已提交
566 567 568 569 570 571 572 573
	struct inode *inode;
	struct dentry *entry;
	int err = -ESTALE;

	if (handle->nodeid == 0)
		goto out_err;

	inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594
	if (!inode) {
		struct fuse_entry_out outarg;
		struct qstr name;

		if (!fc->export_support)
			goto out_err;

		name.len = 1;
		name.name = ".";
		err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
				       &inode);
		if (err && err != -ENOENT)
			goto out_err;
		if (err || !inode) {
			err = -ESTALE;
			goto out_err;
		}
		err = -EIO;
		if (get_node_id(inode) != handle->nodeid)
			goto out_iput;
	}
M
Miklos Szeredi 已提交
595 596 597 598
	err = -ESTALE;
	if (inode->i_generation != handle->generation)
		goto out_iput;

599 600
	entry = d_obtain_alias(inode);
	if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) {
M
Miklos Szeredi 已提交
601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677
		entry->d_op = &fuse_dentry_operations;
		fuse_invalidate_entry_cache(entry);
	}

	return entry;

 out_iput:
	iput(inode);
 out_err:
	return ERR_PTR(err);
}

static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
			   int connectable)
{
	struct inode *inode = dentry->d_inode;
	bool encode_parent = connectable && !S_ISDIR(inode->i_mode);
	int len = encode_parent ? 6 : 3;
	u64 nodeid;
	u32 generation;

	if (*max_len < len)
		return  255;

	nodeid = get_fuse_inode(inode)->nodeid;
	generation = inode->i_generation;

	fh[0] = (u32)(nodeid >> 32);
	fh[1] = (u32)(nodeid & 0xffffffff);
	fh[2] = generation;

	if (encode_parent) {
		struct inode *parent;

		spin_lock(&dentry->d_lock);
		parent = dentry->d_parent->d_inode;
		nodeid = get_fuse_inode(parent)->nodeid;
		generation = parent->i_generation;
		spin_unlock(&dentry->d_lock);

		fh[3] = (u32)(nodeid >> 32);
		fh[4] = (u32)(nodeid & 0xffffffff);
		fh[5] = generation;
	}

	*max_len = len;
	return encode_parent ? 0x82 : 0x81;
}

static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
		struct fid *fid, int fh_len, int fh_type)
{
	struct fuse_inode_handle handle;

	if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
		return NULL;

	handle.nodeid = (u64) fid->raw[0] << 32;
	handle.nodeid |= (u64) fid->raw[1];
	handle.generation = fid->raw[2];
	return fuse_get_dentry(sb, &handle);
}

static struct dentry *fuse_fh_to_parent(struct super_block *sb,
		struct fid *fid, int fh_len, int fh_type)
{
	struct fuse_inode_handle parent;

	if (fh_type != 0x82 || fh_len < 6)
		return NULL;

	parent.nodeid = (u64) fid->raw[3] << 32;
	parent.nodeid |= (u64) fid->raw[4];
	parent.generation = fid->raw[5];
	return fuse_get_dentry(sb, &parent);
}

678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694
static struct dentry *fuse_get_parent(struct dentry *child)
{
	struct inode *child_inode = child->d_inode;
	struct fuse_conn *fc = get_fuse_conn(child_inode);
	struct inode *inode;
	struct dentry *parent;
	struct fuse_entry_out outarg;
	struct qstr name;
	int err;

	if (!fc->export_support)
		return ERR_PTR(-ESTALE);

	name.len = 2;
	name.name = "..";
	err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
			       &name, &outarg, &inode);
695 696 697
	if (err) {
		if (err == -ENOENT)
			return ERR_PTR(-ESTALE);
698 699
		return ERR_PTR(err);
	}
700 701 702

	parent = d_obtain_alias(inode);
	if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) {
703 704 705 706 707 708
		parent->d_op = &fuse_dentry_operations;
		fuse_invalidate_entry_cache(parent);
	}

	return parent;
}
M
Miklos Szeredi 已提交
709 710 711 712 713

static const struct export_operations fuse_export_operations = {
	.fh_to_dentry	= fuse_fh_to_dentry,
	.fh_to_parent	= fuse_fh_to_parent,
	.encode_fh	= fuse_encode_fh,
714
	.get_parent	= fuse_get_parent,
M
Miklos Szeredi 已提交
715 716
};

717
static const struct super_operations fuse_super_operations = {
M
Miklos Szeredi 已提交
718 719 720
	.alloc_inode    = fuse_alloc_inode,
	.destroy_inode  = fuse_destroy_inode,
	.clear_inode	= fuse_clear_inode,
M
Miklos Szeredi 已提交
721
	.drop_inode	= generic_delete_inode,
722
	.remount_fs	= fuse_remount_fs,
M
Miklos Szeredi 已提交
723
	.put_super	= fuse_put_super,
724
	.umount_begin	= fuse_umount_begin,
725
	.statfs		= fuse_statfs,
M
Miklos Szeredi 已提交
726 727 728
	.show_options	= fuse_show_options,
};

729 730 731 732 733 734 735
static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
{
	struct fuse_init_out *arg = &req->misc.init_out;

	if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
		fc->conn_error = 1;
	else {
736 737 738 739 740 741
		unsigned long ra_pages;

		if (arg->minor >= 6) {
			ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
			if (arg->flags & FUSE_ASYNC_READ)
				fc->async_read = 1;
742 743
			if (!(arg->flags & FUSE_POSIX_LOCKS))
				fc->no_lock = 1;
744 745
			if (arg->flags & FUSE_ATOMIC_O_TRUNC)
				fc->atomic_o_trunc = 1;
746 747 748 749 750
			if (arg->minor >= 9) {
				/* LOOKUP has dependency on proto version */
				if (arg->flags & FUSE_EXPORT_SUPPORT)
					fc->export_support = 1;
			}
751 752
			if (arg->flags & FUSE_BIG_WRITES)
				fc->big_writes = 1;
753
		} else {
754
			ra_pages = fc->max_read / PAGE_CACHE_SIZE;
755 756
			fc->no_lock = 1;
		}
757 758

		fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
759 760
		fc->minor = arg->minor;
		fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
761
		fc->max_write = max_t(unsigned, 4096, fc->max_write);
762
		fc->conn_init = 1;
763
	}
764 765
	fc->blocked = 0;
	wake_up_all(&fc->blocked_waitq);
766 767
}

768
static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
769 770
{
	struct fuse_init_in *arg = &req->misc.init_in;
M
Miklos Szeredi 已提交
771

772 773
	arg->major = FUSE_KERNEL_VERSION;
	arg->minor = FUSE_KERNEL_MINOR_VERSION;
774
	arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
775
	arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
776
		FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES;
777 778 779 780 781 782 783 784 785 786 787 788
	req->in.h.opcode = FUSE_INIT;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(*arg);
	req->in.args[0].value = arg;
	req->out.numargs = 1;
	/* Variable length arguement used for backward compatibility
	   with interface version < 7.5.  Rest of init_out is zeroed
	   by do_get_request(), so a short reply is not a problem */
	req->out.argvar = 1;
	req->out.args[0].size = sizeof(struct fuse_init_out);
	req->out.args[0].value = &req->misc.init_out;
	req->end = process_init_reply;
789
	fuse_request_send_background(fc, req);
790 791
}

T
Tejun Heo 已提交
792 793 794 795 796
static void fuse_free_conn(struct fuse_conn *fc)
{
	kfree(fc);
}

M
Miklos Szeredi 已提交
797 798 799 800 801 802
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;
803
	struct dentry *root_dentry;
804
	struct fuse_req *init_req;
M
Miklos Szeredi 已提交
805
	int err;
M
Miklos Szeredi 已提交
806
	int is_bdev = sb->s_bdev != NULL;
M
Miklos Szeredi 已提交
807

808 809 810
	if (sb->s_flags & MS_MANDLOCK)
		return -EINVAL;

M
Miklos Szeredi 已提交
811
	if (!parse_fuse_opt((char *) data, &d, is_bdev))
M
Miklos Szeredi 已提交
812 813
		return -EINVAL;

M
Miklos Szeredi 已提交
814
	if (is_bdev) {
815
#ifdef CONFIG_BLOCK
M
Miklos Szeredi 已提交
816 817
		if (!sb_set_blocksize(sb, d.blksize))
			return -EINVAL;
818
#endif
M
Miklos Szeredi 已提交
819 820 821 822
	} else {
		sb->s_blocksize = PAGE_CACHE_SIZE;
		sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	}
M
Miklos Szeredi 已提交
823 824 825
	sb->s_magic = FUSE_SUPER_MAGIC;
	sb->s_op = &fuse_super_operations;
	sb->s_maxbytes = MAX_LFS_FILESIZE;
M
Miklos Szeredi 已提交
826
	sb->s_export_op = &fuse_export_operations;
M
Miklos Szeredi 已提交
827 828 829 830 831

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

M
Miklos Szeredi 已提交
832 833
	if (file->f_op != &fuse_dev_operations) {
		fput(file);
M
Miklos Szeredi 已提交
834
		return -EINVAL;
M
Miklos Szeredi 已提交
835
	}
M
Miklos Szeredi 已提交
836

837
	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
M
Miklos Szeredi 已提交
838 839
	if (!fc) {
		fput(file);
M
Miklos Szeredi 已提交
840
		return -ENOMEM;
M
Miklos Szeredi 已提交
841
	}
M
Miklos Szeredi 已提交
842

843 844
	err = fuse_conn_init(fc, sb);
	if (err) {
M
Miklos Szeredi 已提交
845
		fput(file);
846 847 848 849
		kfree(fc);
		return err;
	}

T
Tejun Heo 已提交
850
	fc->release = fuse_free_conn;
M
Miklos Szeredi 已提交
851
	fc->flags = d.flags;
M
Miklos Szeredi 已提交
852
	fc->user_id = d.user_id;
853
	fc->group_id = d.group_id;
854
	fc->max_read = max_t(unsigned, 4096, d.max_read);
M
Miklos Szeredi 已提交
855

856 857 858
	/* Used by get_root_inode() */
	sb->s_fs_info = fc;

M
Miklos Szeredi 已提交
859
	err = -ENOMEM;
860
	root = fuse_get_root_inode(sb, d.rootmode);
861
	if (!root)
M
Miklos Szeredi 已提交
862 863
		goto err;

864 865
	root_dentry = d_alloc_root(root);
	if (!root_dentry) {
M
Miklos Szeredi 已提交
866 867 868
		iput(root);
		goto err;
	}
869

870 871 872 873
	init_req = fuse_request_alloc();
	if (!init_req)
		goto err_put_root;

874 875 876
	if (is_bdev) {
		fc->destroy_req = fuse_request_alloc();
		if (!fc->destroy_req)
J
Julia Lawall 已提交
877
			goto err_free_init_req;
878 879
	}

880
	mutex_lock(&fuse_mutex);
881 882
	err = -EINVAL;
	if (file->private_data)
883
		goto err_unlock;
884

885 886 887 888 889
	err = fuse_ctl_add_conn(fc);
	if (err)
		goto err_unlock;

	list_add_tail(&fc->entry, &fuse_conn_list);
890 891
	sb->s_root = root_dentry;
	fc->connected = 1;
892 893
	file->private_data = fuse_conn_get(fc);
	mutex_unlock(&fuse_mutex);
M
Miklos Szeredi 已提交
894 895 896 897 898 899
	/*
	 * atomic_dec_and_test() in fput() provides the necessary
	 * memory barrier for file->private_data to be visible on all
	 * CPUs after this
	 */
	fput(file);
900

901
	fuse_send_init(fc, init_req);
902

M
Miklos Szeredi 已提交
903 904
	return 0;

905 906
 err_unlock:
	mutex_unlock(&fuse_mutex);
J
Julia Lawall 已提交
907
 err_free_init_req:
908
	fuse_request_free(init_req);
909 910
 err_put_root:
	dput(root_dentry);
M
Miklos Szeredi 已提交
911
 err:
M
Miklos Szeredi 已提交
912
	fput(file);
913
	fuse_conn_put(fc);
M
Miklos Szeredi 已提交
914 915 916
	return err;
}

917 918 919
static int fuse_get_sb(struct file_system_type *fs_type,
		       int flags, const char *dev_name,
		       void *raw_data, struct vfsmount *mnt)
M
Miklos Szeredi 已提交
920
{
921
	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
M
Miklos Szeredi 已提交
922 923
}

924 925 926
static struct file_system_type fuse_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "fuse",
M
Miklos Szeredi 已提交
927
	.fs_flags	= FS_HAS_SUBTYPE,
928 929 930 931 932
	.get_sb		= fuse_get_sb,
	.kill_sb	= kill_anon_super,
};

#ifdef CONFIG_BLOCK
933 934 935 936 937 938 939 940 941 942 943 944 945
static int fuse_get_sb_blk(struct file_system_type *fs_type,
			   int flags, const char *dev_name,
			   void *raw_data, struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
			   mnt);
}

static struct file_system_type fuseblk_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "fuseblk",
	.get_sb		= fuse_get_sb_blk,
	.kill_sb	= kill_block_super,
A
Alexey Dobriyan 已提交
946
	.fs_flags	= FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
947 948
};

949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968
static inline int register_fuseblk(void)
{
	return register_filesystem(&fuseblk_fs_type);
}

static inline void unregister_fuseblk(void)
{
	unregister_filesystem(&fuseblk_fs_type);
}
#else
static inline int register_fuseblk(void)
{
	return 0;
}

static inline void unregister_fuseblk(void)
{
}
#endif

969
static void fuse_inode_init_once(void *foo)
M
Miklos Szeredi 已提交
970
{
M
Miklos Szeredi 已提交
971
	struct inode *inode = foo;
M
Miklos Szeredi 已提交
972

C
Christoph Lameter 已提交
973
	inode_init_once(inode);
M
Miklos Szeredi 已提交
974 975 976 977 978 979 980 981
}

static int __init fuse_fs_init(void)
{
	int err;

	err = register_filesystem(&fuse_fs_type);
	if (err)
982 983
		goto out;

984
	err = register_fuseblk();
985 986 987 988 989 990
	if (err)
		goto out_unreg;

	fuse_inode_cachep = kmem_cache_create("fuse_inode",
					      sizeof(struct fuse_inode),
					      0, SLAB_HWCACHE_ALIGN,
991
					      fuse_inode_init_once);
992 993 994 995 996
	err = -ENOMEM;
	if (!fuse_inode_cachep)
		goto out_unreg2;

	return 0;
M
Miklos Szeredi 已提交
997

998
 out_unreg2:
999
	unregister_fuseblk();
1000 1001 1002
 out_unreg:
	unregister_filesystem(&fuse_fs_type);
 out:
M
Miklos Szeredi 已提交
1003 1004 1005 1006 1007 1008
	return err;
}

static void fuse_fs_cleanup(void)
{
	unregister_filesystem(&fuse_fs_type);
1009
	unregister_fuseblk();
M
Miklos Szeredi 已提交
1010 1011 1012
	kmem_cache_destroy(fuse_inode_cachep);
}

1013 1014 1015
static struct kobject *fuse_kobj;
static struct kobject *connections_kobj;

1016 1017 1018 1019
static int fuse_sysfs_init(void)
{
	int err;

1020
	fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1021 1022
	if (!fuse_kobj) {
		err = -ENOMEM;
1023
		goto out_err;
1024
	}
1025

1026 1027 1028
	connections_kobj = kobject_create_and_add("connections", fuse_kobj);
	if (!connections_kobj) {
		err = -ENOMEM;
1029
		goto out_fuse_unregister;
1030
	}
1031 1032 1033 1034

	return 0;

 out_fuse_unregister:
1035
	kobject_put(fuse_kobj);
1036 1037 1038 1039 1040 1041
 out_err:
	return err;
}

static void fuse_sysfs_cleanup(void)
{
1042 1043
	kobject_put(connections_kobj);
	kobject_put(fuse_kobj);
1044 1045
}

M
Miklos Szeredi 已提交
1046 1047 1048 1049
static int __init fuse_init(void)
{
	int res;

M
Miklos Szeredi 已提交
1050
	printk(KERN_INFO "fuse init (API version %i.%i)\n",
M
Miklos Szeredi 已提交
1051 1052
	       FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);

1053
	INIT_LIST_HEAD(&fuse_conn_list);
M
Miklos Szeredi 已提交
1054 1055 1056 1057
	res = fuse_fs_init();
	if (res)
		goto err;

M
Miklos Szeredi 已提交
1058 1059 1060 1061
	res = fuse_dev_init();
	if (res)
		goto err_fs_cleanup;

1062 1063 1064 1065
	res = fuse_sysfs_init();
	if (res)
		goto err_dev_cleanup;

1066 1067 1068 1069
	res = fuse_ctl_init();
	if (res)
		goto err_sysfs_cleanup;

M
Miklos Szeredi 已提交
1070 1071
	return 0;

1072 1073
 err_sysfs_cleanup:
	fuse_sysfs_cleanup();
1074 1075
 err_dev_cleanup:
	fuse_dev_cleanup();
M
Miklos Szeredi 已提交
1076 1077
 err_fs_cleanup:
	fuse_fs_cleanup();
M
Miklos Szeredi 已提交
1078 1079 1080 1081 1082 1083 1084 1085
 err:
	return res;
}

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

1086
	fuse_ctl_cleanup();
1087
	fuse_sysfs_cleanup();
M
Miklos Szeredi 已提交
1088
	fuse_fs_cleanup();
M
Miklos Szeredi 已提交
1089
	fuse_dev_cleanup();
M
Miklos Szeredi 已提交
1090 1091 1092 1093
}

module_init(fuse_init);
module_exit(fuse_exit);