/*
   * Squashfs - a compressed read only filesystem for Linux
   *
   * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008

   * Phillip Lougher <phillip@squashfs.org.uk>

   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2,
   * or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   *
   * 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 "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)
  {
  	int err;
  
  	err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->uid), &inode->i_uid);
  	if (err)
  		return err;
  
  	err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->guid), &inode->i_gid);
  	if (err)
  		return err;
  
  	inode->i_ino = le32_to_cpu(sqsh_ino->inode_number);
  	inode->i_mtime.tv_sec = le32_to_cpu(sqsh_ino->mtime);
  	inode->i_atime.tv_sec = inode->i_mtime.tv_sec;
  	inode->i_ctime.tv_sec = inode->i_mtime.tv_sec;
  	inode->i_mode = le16_to_cpu(sqsh_ino->mode);
  	inode->i_size = 0;
  
  	return err;
  }
  
  
  struct inode *squashfs_iget(struct super_block *sb, long long ino,
  				unsigned int ino_number)
  {
  	struct inode *inode = iget_locked(sb, ino_number);
  	int err;
  
  	TRACE("Entered squashfs_iget
  ");
  
  	if (!inode)
  		return ERR_PTR(-ENOMEM);
  	if (!(inode->i_state & I_NEW))
  		return inode;
  
  	err = squashfs_read_inode(inode, ino);
  	if (err) {
  		iget_failed(inode);
  		return ERR_PTR(err);
  	}
  
  	unlock_new_inode(inode);
  	return inode;
  }
  
  
  /*
   * 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)
  {
  	struct super_block *sb = inode->i_sb;
  	struct squashfs_sb_info *msblk = sb->s_fs_info;
  	u64 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table;
  	int err, type, offset = SQUASHFS_INODE_OFFSET(ino);
  	union squashfs_inode squashfs_ino;
  	struct squashfs_base_inode *sqshb_ino = &squashfs_ino.base;

  	int xattr_id = SQUASHFS_INVALID_XATTR;

  
  	TRACE("Entered squashfs_read_inode
  ");
  
  	/*
  	 * Read inode base common to all inode types.
  	 */
  	err = squashfs_read_metadata(sb, sqshb_ino, &block,
  				&offset, sizeof(*sqshb_ino));
  	if (err < 0)
  		goto failed_read;
  
  	err = squashfs_new_inode(sb, inode, sqshb_ino);
  	if (err)
  		goto failed_read;
  
  	block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table;
  	offset = SQUASHFS_INODE_OFFSET(ino);
  
  	type = le16_to_cpu(sqshb_ino->inode_type);
  	switch (type) {
  	case SQUASHFS_REG_TYPE: {

  		unsigned int frag_offset, frag;
  		int frag_size;

  		u64 frag_blk;
  		struct squashfs_reg_inode *sqsh_ino = &squashfs_ino.reg;
  
  		err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
  							sizeof(*sqsh_ino));
  		if (err < 0)
  			goto failed_read;
  
  		frag = le32_to_cpu(sqsh_ino->fragment);
  		if (frag != SQUASHFS_INVALID_FRAG) {
  			frag_offset = le32_to_cpu(sqsh_ino->offset);
  			frag_size = squashfs_frag_lookup(sb, frag, &frag_blk);
  			if (frag_size < 0) {
  				err = frag_size;
  				goto failed_read;
  			}
  		} else {
  			frag_blk = SQUASHFS_INVALID_BLK;
  			frag_size = 0;
  			frag_offset = 0;
  		}

  		set_nlink(inode, 1);

  		inode->i_size = le32_to_cpu(sqsh_ino->file_size);
  		inode->i_fop = &generic_ro_fops;
  		inode->i_mode |= S_IFREG;
  		inode->i_blocks = ((inode->i_size - 1) >> 9) + 1;
  		squashfs_i(inode)->fragment_block = frag_blk;
  		squashfs_i(inode)->fragment_size = frag_size;
  		squashfs_i(inode)->fragment_offset = frag_offset;
  		squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);
  		squashfs_i(inode)->block_list_start = block;
  		squashfs_i(inode)->offset = offset;
  		inode->i_data.a_ops = &squashfs_aops;
  
  		TRACE("File inode %x:%x, start_block %llx, block_list_start "
  			"%llx, offset %x
  ", SQUASHFS_INODE_BLK(ino),
  			offset, squashfs_i(inode)->start, block, offset);
  		break;
  	}
  	case SQUASHFS_LREG_TYPE: {

  		unsigned int frag_offset, frag;
  		int frag_size;

  		u64 frag_blk;
  		struct squashfs_lreg_inode *sqsh_ino = &squashfs_ino.lreg;
  
  		err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
  							sizeof(*sqsh_ino));
  		if (err < 0)
  			goto failed_read;
  
  		frag = le32_to_cpu(sqsh_ino->fragment);
  		if (frag != SQUASHFS_INVALID_FRAG) {
  			frag_offset = le32_to_cpu(sqsh_ino->offset);
  			frag_size = squashfs_frag_lookup(sb, frag, &frag_blk);
  			if (frag_size < 0) {
  				err = frag_size;
  				goto failed_read;
  			}
  		} else {
  			frag_blk = SQUASHFS_INVALID_BLK;
  			frag_size = 0;
  			frag_offset = 0;
  		}

  		xattr_id = le32_to_cpu(sqsh_ino->xattr);

  		set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));

  		inode->i_size = le64_to_cpu(sqsh_ino->file_size);

  		inode->i_op = &squashfs_inode_ops;

  		inode->i_fop = &generic_ro_fops;
  		inode->i_mode |= S_IFREG;

  		inode->i_blocks = (inode->i_size -
  				le64_to_cpu(sqsh_ino->sparse) + 511) >> 9;

  
  		squashfs_i(inode)->fragment_block = frag_blk;
  		squashfs_i(inode)->fragment_size = frag_size;
  		squashfs_i(inode)->fragment_offset = frag_offset;
  		squashfs_i(inode)->start = le64_to_cpu(sqsh_ino->start_block);
  		squashfs_i(inode)->block_list_start = block;
  		squashfs_i(inode)->offset = offset;
  		inode->i_data.a_ops = &squashfs_aops;
  
  		TRACE("File inode %x:%x, start_block %llx, block_list_start "
  			"%llx, offset %x
  ", SQUASHFS_INODE_BLK(ino),
  			offset, squashfs_i(inode)->start, block, offset);
  		break;
  	}
  	case SQUASHFS_DIR_TYPE: {
  		struct squashfs_dir_inode *sqsh_ino = &squashfs_ino.dir;
  
  		err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
  				sizeof(*sqsh_ino));
  		if (err < 0)
  			goto failed_read;

  		set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));

  		inode->i_size = le16_to_cpu(sqsh_ino->file_size);
  		inode->i_op = &squashfs_dir_inode_ops;
  		inode->i_fop = &squashfs_dir_ops;
  		inode->i_mode |= S_IFDIR;
  		squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);
  		squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset);
  		squashfs_i(inode)->dir_idx_cnt = 0;
  		squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode);
  
  		TRACE("Directory inode %x:%x, start_block %llx, offset %x
  ",
  				SQUASHFS_INODE_BLK(ino), offset,
  				squashfs_i(inode)->start,
  				le16_to_cpu(sqsh_ino->offset));
  		break;
  	}
  	case SQUASHFS_LDIR_TYPE: {
  		struct squashfs_ldir_inode *sqsh_ino = &squashfs_ino.ldir;
  
  		err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
  				sizeof(*sqsh_ino));
  		if (err < 0)
  			goto failed_read;

  		xattr_id = le32_to_cpu(sqsh_ino->xattr);

  		set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));

  		inode->i_size = le32_to_cpu(sqsh_ino->file_size);
  		inode->i_op = &squashfs_dir_inode_ops;
  		inode->i_fop = &squashfs_dir_ops;
  		inode->i_mode |= S_IFDIR;
  		squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);
  		squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset);
  		squashfs_i(inode)->dir_idx_start = block;
  		squashfs_i(inode)->dir_idx_offset = offset;
  		squashfs_i(inode)->dir_idx_cnt = le16_to_cpu(sqsh_ino->i_count);
  		squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode);
  
  		TRACE("Long directory inode %x:%x, start_block %llx, offset "
  				"%x
  ", SQUASHFS_INODE_BLK(ino), offset,
  				squashfs_i(inode)->start,
  				le16_to_cpu(sqsh_ino->offset));
  		break;
  	}
  	case SQUASHFS_SYMLINK_TYPE:
  	case SQUASHFS_LSYMLINK_TYPE: {
  		struct squashfs_symlink_inode *sqsh_ino = &squashfs_ino.symlink;
  
  		err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
  				sizeof(*sqsh_ino));
  		if (err < 0)
  			goto failed_read;

  		set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));

  		inode->i_size = le32_to_cpu(sqsh_ino->symlink_size);

  		inode->i_op = &squashfs_symlink_inode_ops;

  		inode->i_data.a_ops = &squashfs_symlink_aops;
  		inode->i_mode |= S_IFLNK;
  		squashfs_i(inode)->start = block;
  		squashfs_i(inode)->offset = offset;

  		if (type == SQUASHFS_LSYMLINK_TYPE) {
  			__le32 xattr;
  
  			err = squashfs_read_metadata(sb, NULL, &block,
  						&offset, inode->i_size);
  			if (err < 0)
  				goto failed_read;
  			err = squashfs_read_metadata(sb, &xattr, &block,
  						&offset, sizeof(xattr));
  			if (err < 0)
  				goto failed_read;
  			xattr_id = le32_to_cpu(xattr);
  		}

  		TRACE("Symbolic link inode %x:%x, start_block %llx, offset "
  				"%x
  ", SQUASHFS_INODE_BLK(ino), offset,
  				block, offset);
  		break;
  	}
  	case SQUASHFS_BLKDEV_TYPE:

  	case SQUASHFS_CHRDEV_TYPE: {

  		struct squashfs_dev_inode *sqsh_ino = &squashfs_ino.dev;
  		unsigned int rdev;
  
  		err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
  				sizeof(*sqsh_ino));
  		if (err < 0)
  			goto failed_read;
  
  		if (type == SQUASHFS_CHRDEV_TYPE)
  			inode->i_mode |= S_IFCHR;
  		else
  			inode->i_mode |= S_IFBLK;

  		set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));

  		rdev = le32_to_cpu(sqsh_ino->rdev);
  		init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));
  
  		TRACE("Device inode %x:%x, rdev %x
  ",
  				SQUASHFS_INODE_BLK(ino), offset, rdev);
  		break;
  	}

  	case SQUASHFS_LBLKDEV_TYPE:
  	case SQUASHFS_LCHRDEV_TYPE: {
  		struct squashfs_ldev_inode *sqsh_ino = &squashfs_ino.ldev;
  		unsigned int rdev;
  
  		err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
  				sizeof(*sqsh_ino));
  		if (err < 0)
  			goto failed_read;
  
  		if (type == SQUASHFS_LCHRDEV_TYPE)
  			inode->i_mode |= S_IFCHR;
  		else
  			inode->i_mode |= S_IFBLK;
  		xattr_id = le32_to_cpu(sqsh_ino->xattr);
  		inode->i_op = &squashfs_inode_ops;

  		set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));

  		rdev = le32_to_cpu(sqsh_ino->rdev);
  		init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));
  
  		TRACE("Device inode %x:%x, rdev %x
  ",
  				SQUASHFS_INODE_BLK(ino), offset, rdev);
  		break;
  	}

  	case SQUASHFS_FIFO_TYPE:

  	case SQUASHFS_SOCKET_TYPE: {

  		struct squashfs_ipc_inode *sqsh_ino = &squashfs_ino.ipc;
  
  		err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
  				sizeof(*sqsh_ino));
  		if (err < 0)
  			goto failed_read;
  
  		if (type == SQUASHFS_FIFO_TYPE)
  			inode->i_mode |= S_IFIFO;
  		else
  			inode->i_mode |= S_IFSOCK;

  		set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));

  		init_special_inode(inode, inode->i_mode, 0);
  		break;
  	}

  	case SQUASHFS_LFIFO_TYPE:
  	case SQUASHFS_LSOCKET_TYPE: {
  		struct squashfs_lipc_inode *sqsh_ino = &squashfs_ino.lipc;
  
  		err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
  				sizeof(*sqsh_ino));
  		if (err < 0)
  			goto failed_read;
  
  		if (type == SQUASHFS_LFIFO_TYPE)
  			inode->i_mode |= S_IFIFO;
  		else
  			inode->i_mode |= S_IFSOCK;
  		xattr_id = le32_to_cpu(sqsh_ino->xattr);
  		inode->i_op = &squashfs_inode_ops;

  		set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));

  		init_special_inode(inode, inode->i_mode, 0);
  		break;
  	}

  	default:
  		ERROR("Unknown inode type %d in squashfs_iget!
  ", type);
  		return -EINVAL;
  	}

  	if (xattr_id != SQUASHFS_INVALID_XATTR && msblk->xattr_id_table) {
  		err = squashfs_xattr_lookup(sb, xattr_id,
  					&squashfs_i(inode)->xattr_count,
  					&squashfs_i(inode)->xattr_size,
  					&squashfs_i(inode)->xattr);
  		if (err < 0)
  			goto failed_read;
  		inode->i_blocks += ((squashfs_i(inode)->xattr_size - 1) >> 9)
  				+ 1;
  	} else
  		squashfs_i(inode)->xattr_count = 0;

  	return 0;
  
  failed_read:
  	ERROR("Unable to read inode 0x%llx
  ", ino);
  	return err;
  }

  
  
  const struct inode_operations squashfs_inode_ops = {
  	.getxattr = generic_getxattr,
  	.listxattr = squashfs_listxattr
  };