linux/fs/squashfs/inode.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Squashfs - a compressed read only filesystem for Linux
 *
 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
 * Phillip Lougher <[email protected]>
 *
 * inode.c
 */

/*
 * This file implements code to create and read inodes from disk.
 *
 * Inodes in Squashfs are identified by a 48-bit inode which encodes the
 * location of the compressed metadata block containing the inode, and the byte
 * offset into that block where the inode is placed (<block, offset>).
 *
 * To maximise compression there are different inodes for each file type
 * (regular file, directory, device, etc.), the inode contents and length
 * varying with the type.
 *
 * To further maximise compression, two types of regular file inode and
 * directory inode are defined: inodes optimised for frequently occurring
 * regular files and directories, and extended types where extra
 * information has to be stored.
 */

#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/xattr.h>
#include <linux/pagemap.h>

#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs_fs_i.h"
#include "squashfs.h"
#include "xattr.h"

/*
 * Initialise VFS inode with the base inode information common to all
 * Squashfs inode types.  Sqsh_ino contains the unswapped base inode
 * off disk.
 */
static int squashfs_new_inode(struct super_block *sb, struct inode *inode,
				struct squashfs_base_inode *sqsh_ino)
{ … }


struct inode *squashfs_iget(struct super_block *sb, long long ino,
				unsigned int ino_number)
{ … }


/*
 * Initialise VFS inode by reading inode from inode table (compressed
 * metadata).  The format and amount of data read depends on type.
 */
int squashfs_read_inode(struct inode *inode, long long ino)
{ … }


const struct inode_operations squashfs_inode_ops = …;