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Release 4.18 fs/squashfs/inode.c

Directory: fs/squashfs
/*
 * 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 <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) { uid_t i_uid; gid_t i_gid; int err; err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->uid), &i_uid); if (err) return err; err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->guid), &i_gid); if (err) return err; i_uid_write(inode, i_uid); i_gid_write(inode, i_gid); 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; }

Contributors

PersonTokensPropCommitsCommitProp
Phillip Lougher14087.50%150.00%
Eric W. Biedermann2012.50%150.00%
Total160100.00%2100.00%


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\n"); 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; }

Contributors

PersonTokensPropCommitsCommitProp
Phillip Lougher100100.00%1100.00%
Total100100.00%1100.00%

/* * 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\n"); /* * 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\n", 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\n", 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\n", 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\n", 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_nohighmem(inode); 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\n", 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\n", 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\n", 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!\n", 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\n", ino); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Phillip Lougher181697.48%350.00%
Miklos Szeredi361.93%116.67%
Roel Kluin60.32%116.67%
Al Viro50.27%116.67%
Total1863100.00%6100.00%

const struct inode_operations squashfs_inode_ops = { .listxattr = squashfs_listxattr };

Overall Contributors

PersonTokensPropCommitsCommitProp
Phillip Lougher209696.77%555.56%
Miklos Szeredi361.66%111.11%
Eric W. Biedermann200.92%111.11%
Al Viro80.37%111.11%
Roel Kluin60.28%111.11%
Total2166100.00%9100.00%
Directory: fs/squashfs
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