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/*
* Copyright (c) 2003 Silicon Graphics, Inc. All Rights Reserved.
*
* Mostly shameless copied from Linus Torvalds' ramfs and thus
* Copyright (C) 2000 Linus Torvalds.
* 2000 Transmeta Corp.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* Further, this software is distributed without any warranty that it is
* free of the rightful claim of any third person regarding infringement
* or the like. Any license provided herein, whether implied or
* otherwise, applies only to this software file. Patent licenses, if
* any, provided herein do not apply to combinations of this program with
* other software, or any other product whatsoever.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
* Mountain View, CA 94043, or:
*
* http://www.sgi.com
*
* For further information regarding this notice, see:
*
* http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
*/
#include <linux/module.h>
#include <linux/backing-dev.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/string.h>
#include <asm/uaccess.h>
/* some random number */
#define HWGFS_MAGIC 0x12061983
static struct super_operations hwgfs_ops;
static struct address_space_operations hwgfs_aops;
static struct file_operations hwgfs_file_operations;
static struct inode_operations hwgfs_file_inode_operations;
static struct inode_operations hwgfs_dir_inode_operations;
static struct backing_dev_info hwgfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.memory_backed = 1, /* Does not contribute to dirty memory */
};
struct inode *hwgfs_get_inode(struct super_block *sb, int mode, dev_t dev)
{
struct inode * inode = new_inode(sb);
if (inode) {
inode->i_mode = mode;
inode->i_uid = current->fsuid;
inode->i_gid = current->fsgid;
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_rdev = NODEV;
inode->i_mapping->a_ops = &hwgfs_aops;
inode->i_mapping->backing_dev_info = &hwgfs_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
switch (mode & S_IFMT) {
default:
init_special_inode(inode, mode, dev);
break;
case S_IFREG:
inode->i_op = &hwgfs_file_inode_operations;
inode->i_fop = &hwgfs_file_operations;
break;
case S_IFDIR:
inode->i_op = &hwgfs_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
inode->i_nlink++;
break;
case S_IFLNK:
inode->i_op = &page_symlink_inode_operations;
break;
}
}
return inode;
}
static int hwgfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
{
struct inode * inode = hwgfs_get_inode(dir->i_sb, mode, dev);
int error = -ENOSPC;
if (inode) {
d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
error = 0;
}
return error;
}
static int hwgfs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
{
return hwgfs_mknod(dir, dentry, mode | S_IFDIR, 0);
}
static int hwgfs_create(struct inode *dir, struct dentry *dentry, int mode)
{
return hwgfs_mknod(dir, dentry, mode | S_IFREG, 0);
}
static int hwgfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname)
{
struct inode *inode;
int error = -ENOSPC;
inode = hwgfs_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0);
if (inode) {
int l = strlen(symname)+1;
error = page_symlink(inode, symname, l);
if (!error) {
d_instantiate(dentry, inode);
dget(dentry);
} else
iput(inode);
}
return error;
}
static struct address_space_operations hwgfs_aops = {
.readpage = simple_readpage,
.prepare_write = simple_prepare_write,
.commit_write = simple_commit_write
};
static struct file_operations hwgfs_file_operations = {
.read = generic_file_read,
.write = generic_file_write,
.mmap = generic_file_mmap,
.fsync = simple_sync_file,
.sendfile = generic_file_sendfile,
};
static struct inode_operations hwgfs_file_inode_operations = {
.getattr = simple_getattr,
};
static struct inode_operations hwgfs_dir_inode_operations = {
.create = hwgfs_create,
.lookup = simple_lookup,
.link = simple_link,
.unlink = simple_unlink,
.symlink = hwgfs_symlink,
.mkdir = hwgfs_mkdir,
.rmdir = simple_rmdir,
.mknod = hwgfs_mknod,
.rename = simple_rename,
};
static struct super_operations hwgfs_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
};
static int hwgfs_fill_super(struct super_block * sb, void * data, int silent)
{
struct inode * inode;
struct dentry * root;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = HWGFS_MAGIC;
sb->s_op = &hwgfs_ops;
inode = hwgfs_get_inode(sb, S_IFDIR | 0755, 0);
if (!inode)
return -ENOMEM;
root = d_alloc_root(inode);
if (!root) {
iput(inode);
return -ENOMEM;
}
sb->s_root = root;
return 0;
}
static struct super_block *hwgfs_get_sb(struct file_system_type *fs_type,
int flags, char *dev_name, void *data)
{
return get_sb_single(fs_type, flags, data, hwgfs_fill_super);
}
static struct file_system_type hwgfs_fs_type = {
.owner = THIS_MODULE,
.name = "hwgfs",
.get_sb = hwgfs_get_sb,
.kill_sb = kill_litter_super,
};
struct vfsmount *hwgfs_vfsmount;
int __init init_hwgfs_fs(void)
{
int error;
error = register_filesystem(&hwgfs_fs_type);
if (error)
return error;
hwgfs_vfsmount = kern_mount(&hwgfs_fs_type);
if (IS_ERR(hwgfs_vfsmount))
goto fail;
return 0;
fail:
unregister_filesystem(&hwgfs_fs_type);
return PTR_ERR(hwgfs_vfsmount);
}
static void __exit exit_hwgfs_fs(void)
{
unregister_filesystem(&hwgfs_fs_type);
}
MODULE_LICENSE("GPL");
module_init(init_hwgfs_fs)
module_exit(exit_hwgfs_fs)
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