path: root/fs/fuse/inode.c

/*
  FUSE: Filesystem in Userspace
  Copyright (C) 2001-2008  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/seq_file.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/parser.h>
#include <linux/statfs.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/exportfs.h>
#include <linux/smp_lock.h>

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

static struct kmem_cache *fuse_inode_cachep;
struct list_head fuse_conn_list;
DEFINE_MUTEX(fuse_mutex);

#define FUSE_SUPER_MAGIC 0x65735546

#define FUSE_DEFAULT_BLKSIZE 512

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

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

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

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

void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
		      u64 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;
	fuse_request_send_noreply(fc, req);
}

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

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

	return 0;
}

void fuse_truncate(struct address_space *mapping, loff_t offset)
{
	/* See vmtruncate() */
	unmap_mapping_range(mapping, offset + PAGE_SIZE -