426 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Squashfs - a compressed read only filesystem for Linux4 *5 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 20086 * Phillip Lougher <phillip@squashfs.org.uk>7 *8 * inode.c9 */10 11/*12 * This file implements code to create and read inodes from disk.13 *14 * Inodes in Squashfs are identified by a 48-bit inode which encodes the15 * location of the compressed metadata block containing the inode, and the byte16 * offset into that block where the inode is placed (<block, offset>).17 *18 * To maximise compression there are different inodes for each file type19 * (regular file, directory, device, etc.), the inode contents and length20 * varying with the type.21 *22 * To further maximise compression, two types of regular file inode and23 * directory inode are defined: inodes optimised for frequently occurring24 * regular files and directories, and extended types where extra25 * information has to be stored.26 */27 28#include <linux/fs.h>29#include <linux/vfs.h>30#include <linux/xattr.h>31#include <linux/pagemap.h>32 33#include "squashfs_fs.h"34#include "squashfs_fs_sb.h"35#include "squashfs_fs_i.h"36#include "squashfs.h"37#include "xattr.h"38 39/*40 * Initialise VFS inode with the base inode information common to all41 * Squashfs inode types. Sqsh_ino contains the unswapped base inode42 * off disk.43 */44static int squashfs_new_inode(struct super_block *sb, struct inode *inode,45 struct squashfs_base_inode *sqsh_ino)46{47 uid_t i_uid;48 gid_t i_gid;49 int err;50 51 inode->i_ino = le32_to_cpu(sqsh_ino->inode_number);52 if (inode->i_ino == 0)53 return -EINVAL;54 55 err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->uid), &i_uid);56 if (err)57 return err;58 59 err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->guid), &i_gid);60 if (err)61 return err;62 63 i_uid_write(inode, i_uid);64 i_gid_write(inode, i_gid);65 inode_set_mtime(inode, le32_to_cpu(sqsh_ino->mtime), 0);66 inode_set_atime(inode, inode_get_mtime_sec(inode), 0);67 inode_set_ctime(inode, inode_get_mtime_sec(inode), 0);68 inode->i_mode = le16_to_cpu(sqsh_ino->mode);69 inode->i_size = 0;70 71 return err;72}73 74 75struct inode *squashfs_iget(struct super_block *sb, long long ino,76 unsigned int ino_number)77{78 struct inode *inode = iget_locked(sb, ino_number);79 int err;80 81 TRACE("Entered squashfs_iget\n");82 83 if (!inode)84 return ERR_PTR(-ENOMEM);85 if (!(inode->i_state & I_NEW))86 return inode;87 88 err = squashfs_read_inode(inode, ino);89 if (err) {90 iget_failed(inode);91 return ERR_PTR(err);92 }93 94 unlock_new_inode(inode);95 return inode;96}97 98 99/*100 * Initialise VFS inode by reading inode from inode table (compressed101 * metadata). The format and amount of data read depends on type.102 */103int squashfs_read_inode(struct inode *inode, long long ino)104{105 struct super_block *sb = inode->i_sb;106 struct squashfs_sb_info *msblk = sb->s_fs_info;107 u64 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table;108 int err, type, offset = SQUASHFS_INODE_OFFSET(ino);109 union squashfs_inode squashfs_ino;110 struct squashfs_base_inode *sqshb_ino = &squashfs_ino.base;111 int xattr_id = SQUASHFS_INVALID_XATTR;112 113 TRACE("Entered squashfs_read_inode\n");114 115 /*116 * Read inode base common to all inode types.117 */118 err = squashfs_read_metadata(sb, sqshb_ino, &block,119 &offset, sizeof(*sqshb_ino));120 if (err < 0)121 goto failed_read;122 123 err = squashfs_new_inode(sb, inode, sqshb_ino);124 if (err)125 goto failed_read;126 127 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table;128 offset = SQUASHFS_INODE_OFFSET(ino);129 130 type = le16_to_cpu(sqshb_ino->inode_type);131 switch (type) {132 case SQUASHFS_REG_TYPE: {133 unsigned int frag_offset, frag;134 int frag_size;135 u64 frag_blk;136 struct squashfs_reg_inode *sqsh_ino = &squashfs_ino.reg;137 138 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,139 sizeof(*sqsh_ino));140 if (err < 0)141 goto failed_read;142 143 frag = le32_to_cpu(sqsh_ino->fragment);144 if (frag != SQUASHFS_INVALID_FRAG) {145 frag_offset = le32_to_cpu(sqsh_ino->offset);146 frag_size = squashfs_frag_lookup(sb, frag, &frag_blk);147 if (frag_size < 0) {148 err = frag_size;149 goto failed_read;150 }151 } else {152 frag_blk = SQUASHFS_INVALID_BLK;153 frag_size = 0;154 frag_offset = 0;155 }156 157 set_nlink(inode, 1);158 inode->i_size = le32_to_cpu(sqsh_ino->file_size);159 inode->i_fop = &generic_ro_fops;160 inode->i_mode |= S_IFREG;161 inode->i_blocks = ((inode->i_size - 1) >> 9) + 1;162 squashfs_i(inode)->fragment_block = frag_blk;163 squashfs_i(inode)->fragment_size = frag_size;164 squashfs_i(inode)->fragment_offset = frag_offset;165 squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);166 squashfs_i(inode)->block_list_start = block;167 squashfs_i(inode)->offset = offset;168 inode->i_data.a_ops = &squashfs_aops;169 170 TRACE("File inode %x:%x, start_block %llx, block_list_start "171 "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino),172 offset, squashfs_i(inode)->start, block, offset);173 break;174 }175 case SQUASHFS_LREG_TYPE: {176 unsigned int frag_offset, frag;177 int frag_size;178 u64 frag_blk;179 struct squashfs_lreg_inode *sqsh_ino = &squashfs_ino.lreg;180 181 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,182 sizeof(*sqsh_ino));183 if (err < 0)184 goto failed_read;185 186 frag = le32_to_cpu(sqsh_ino->fragment);187 if (frag != SQUASHFS_INVALID_FRAG) {188 frag_offset = le32_to_cpu(sqsh_ino->offset);189 frag_size = squashfs_frag_lookup(sb, frag, &frag_blk);190 if (frag_size < 0) {191 err = frag_size;192 goto failed_read;193 }194 } else {195 frag_blk = SQUASHFS_INVALID_BLK;196 frag_size = 0;197 frag_offset = 0;198 }199 200 xattr_id = le32_to_cpu(sqsh_ino->xattr);201 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));202 inode->i_size = le64_to_cpu(sqsh_ino->file_size);203 inode->i_op = &squashfs_inode_ops;204 inode->i_fop = &generic_ro_fops;205 inode->i_mode |= S_IFREG;206 inode->i_blocks = (inode->i_size -207 le64_to_cpu(sqsh_ino->sparse) + 511) >> 9;208 209 squashfs_i(inode)->fragment_block = frag_blk;210 squashfs_i(inode)->fragment_size = frag_size;211 squashfs_i(inode)->fragment_offset = frag_offset;212 squashfs_i(inode)->start = le64_to_cpu(sqsh_ino->start_block);213 squashfs_i(inode)->block_list_start = block;214 squashfs_i(inode)->offset = offset;215 inode->i_data.a_ops = &squashfs_aops;216 217 TRACE("File inode %x:%x, start_block %llx, block_list_start "218 "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino),219 offset, squashfs_i(inode)->start, block, offset);220 break;221 }222 case SQUASHFS_DIR_TYPE: {223 struct squashfs_dir_inode *sqsh_ino = &squashfs_ino.dir;224 225 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,226 sizeof(*sqsh_ino));227 if (err < 0)228 goto failed_read;229 230 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));231 inode->i_size = le16_to_cpu(sqsh_ino->file_size);232 inode->i_op = &squashfs_dir_inode_ops;233 inode->i_fop = &squashfs_dir_ops;234 inode->i_mode |= S_IFDIR;235 squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);236 squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset);237 squashfs_i(inode)->dir_idx_cnt = 0;238 squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode);239 240 TRACE("Directory inode %x:%x, start_block %llx, offset %x\n",241 SQUASHFS_INODE_BLK(ino), offset,242 squashfs_i(inode)->start,243 le16_to_cpu(sqsh_ino->offset));244 break;245 }246 case SQUASHFS_LDIR_TYPE: {247 struct squashfs_ldir_inode *sqsh_ino = &squashfs_ino.ldir;248 249 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,250 sizeof(*sqsh_ino));251 if (err < 0)252 goto failed_read;253 254 xattr_id = le32_to_cpu(sqsh_ino->xattr);255 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));256 inode->i_size = le32_to_cpu(sqsh_ino->file_size);257 inode->i_op = &squashfs_dir_inode_ops;258 inode->i_fop = &squashfs_dir_ops;259 inode->i_mode |= S_IFDIR;260 squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);261 squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset);262 squashfs_i(inode)->dir_idx_start = block;263 squashfs_i(inode)->dir_idx_offset = offset;264 squashfs_i(inode)->dir_idx_cnt = le16_to_cpu(sqsh_ino->i_count);265 squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode);266 267 TRACE("Long directory inode %x:%x, start_block %llx, offset "268 "%x\n", SQUASHFS_INODE_BLK(ino), offset,269 squashfs_i(inode)->start,270 le16_to_cpu(sqsh_ino->offset));271 break;272 }273 case SQUASHFS_SYMLINK_TYPE:274 case SQUASHFS_LSYMLINK_TYPE: {275 struct squashfs_symlink_inode *sqsh_ino = &squashfs_ino.symlink;276 277 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,278 sizeof(*sqsh_ino));279 if (err < 0)280 goto failed_read;281 282 inode->i_size = le32_to_cpu(sqsh_ino->symlink_size);283 if (inode->i_size > PAGE_SIZE) {284 ERROR("Corrupted symlink\n");285 return -EINVAL;286 }287 288 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));289 inode->i_op = &squashfs_symlink_inode_ops;290 inode_nohighmem(inode);291 inode->i_data.a_ops = &squashfs_symlink_aops;292 inode->i_mode |= S_IFLNK;293 squashfs_i(inode)->start = block;294 squashfs_i(inode)->offset = offset;295 296 if (type == SQUASHFS_LSYMLINK_TYPE) {297 __le32 xattr;298 299 err = squashfs_read_metadata(sb, NULL, &block,300 &offset, inode->i_size);301 if (err < 0)302 goto failed_read;303 err = squashfs_read_metadata(sb, &xattr, &block,304 &offset, sizeof(xattr));305 if (err < 0)306 goto failed_read;307 xattr_id = le32_to_cpu(xattr);308 }309 310 TRACE("Symbolic link inode %x:%x, start_block %llx, offset "311 "%x\n", SQUASHFS_INODE_BLK(ino), offset,312 block, offset);313 break;314 }315 case SQUASHFS_BLKDEV_TYPE:316 case SQUASHFS_CHRDEV_TYPE: {317 struct squashfs_dev_inode *sqsh_ino = &squashfs_ino.dev;318 unsigned int rdev;319 320 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,321 sizeof(*sqsh_ino));322 if (err < 0)323 goto failed_read;324 325 if (type == SQUASHFS_CHRDEV_TYPE)326 inode->i_mode |= S_IFCHR;327 else328 inode->i_mode |= S_IFBLK;329 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));330 rdev = le32_to_cpu(sqsh_ino->rdev);331 init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));332 333 TRACE("Device inode %x:%x, rdev %x\n",334 SQUASHFS_INODE_BLK(ino), offset, rdev);335 break;336 }337 case SQUASHFS_LBLKDEV_TYPE:338 case SQUASHFS_LCHRDEV_TYPE: {339 struct squashfs_ldev_inode *sqsh_ino = &squashfs_ino.ldev;340 unsigned int rdev;341 342 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,343 sizeof(*sqsh_ino));344 if (err < 0)345 goto failed_read;346 347 if (type == SQUASHFS_LCHRDEV_TYPE)348 inode->i_mode |= S_IFCHR;349 else350 inode->i_mode |= S_IFBLK;351 xattr_id = le32_to_cpu(sqsh_ino->xattr);352 inode->i_op = &squashfs_inode_ops;353 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));354 rdev = le32_to_cpu(sqsh_ino->rdev);355 init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));356 357 TRACE("Device inode %x:%x, rdev %x\n",358 SQUASHFS_INODE_BLK(ino), offset, rdev);359 break;360 }361 case SQUASHFS_FIFO_TYPE:362 case SQUASHFS_SOCKET_TYPE: {363 struct squashfs_ipc_inode *sqsh_ino = &squashfs_ino.ipc;364 365 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,366 sizeof(*sqsh_ino));367 if (err < 0)368 goto failed_read;369 370 if (type == SQUASHFS_FIFO_TYPE)371 inode->i_mode |= S_IFIFO;372 else373 inode->i_mode |= S_IFSOCK;374 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));375 init_special_inode(inode, inode->i_mode, 0);376 break;377 }378 case SQUASHFS_LFIFO_TYPE:379 case SQUASHFS_LSOCKET_TYPE: {380 struct squashfs_lipc_inode *sqsh_ino = &squashfs_ino.lipc;381 382 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,383 sizeof(*sqsh_ino));384 if (err < 0)385 goto failed_read;386 387 if (type == SQUASHFS_LFIFO_TYPE)388 inode->i_mode |= S_IFIFO;389 else390 inode->i_mode |= S_IFSOCK;391 xattr_id = le32_to_cpu(sqsh_ino->xattr);392 inode->i_op = &squashfs_inode_ops;393 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));394 init_special_inode(inode, inode->i_mode, 0);395 break;396 }397 default:398 ERROR("Unknown inode type %d in squashfs_iget!\n", type);399 return -EINVAL;400 }401 402 if (xattr_id != SQUASHFS_INVALID_XATTR && msblk->xattr_id_table) {403 err = squashfs_xattr_lookup(sb, xattr_id,404 &squashfs_i(inode)->xattr_count,405 &squashfs_i(inode)->xattr_size,406 &squashfs_i(inode)->xattr);407 if (err < 0)408 goto failed_read;409 inode->i_blocks += ((squashfs_i(inode)->xattr_size - 1) >> 9)410 + 1;411 } else412 squashfs_i(inode)->xattr_count = 0;413 414 return 0;415 416failed_read:417 ERROR("Unable to read inode 0x%llx\n", ino);418 return err;419}420 421 422const struct inode_operations squashfs_inode_ops = {423 .listxattr = squashfs_listxattr424};425 426