1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Squashfs - a compressed read only filesystem for Linux
5 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
6 * Phillip Lougher <phillip@squashfs.org.uk>
12 * This file implements code to create and read inodes from disk.
14 * Inodes in Squashfs are identified by a 48-bit inode which encodes the
15 * location of the compressed metadata block containing the inode, and the byte
16 * offset into that block where the inode is placed (<block, offset>).
18 * To maximise compression there are different inodes for each file type
19 * (regular file, directory, device, etc.), the inode contents and length
20 * varying with the type.
22 * To further maximise compression, two types of regular file inode and
23 * directory inode are defined: inodes optimised for frequently occurring
24 * regular files and directories, and extended types where extra
25 * information has to be stored.
29 #include <linux/vfs.h>
30 #include <linux/xattr.h>
31 #include <linux/pagemap.h>
33 #include "squashfs_fs.h"
34 #include "squashfs_fs_sb.h"
35 #include "squashfs_fs_i.h"
40 * Initialise VFS inode with the base inode information common to all
41 * Squashfs inode types. Sqsh_ino contains the unswapped base inode
44 static int squashfs_new_inode(struct super_block *sb, struct inode *inode,
45 struct squashfs_base_inode *sqsh_ino)
51 inode->i_ino = le32_to_cpu(sqsh_ino->inode_number);
52 if (inode->i_ino == 0)
55 err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->uid), &i_uid);
59 err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->guid), &i_gid);
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);
75 struct inode *squashfs_iget(struct super_block *sb, long long ino,
76 unsigned int ino_number)
78 struct inode *inode = iget_locked(sb, ino_number);
81 TRACE("Entered squashfs_iget\n");
84 return ERR_PTR(-ENOMEM);
85 if (!(inode->i_state & I_NEW))
88 err = squashfs_read_inode(inode, ino);
94 unlock_new_inode(inode);
100 * Initialise VFS inode by reading inode from inode table (compressed
101 * metadata). The format and amount of data read depends on type.
103 int squashfs_read_inode(struct inode *inode, long long ino)
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;
113 TRACE("Entered squashfs_read_inode\n");
116 * Read inode base common to all inode types.
118 err = squashfs_read_metadata(sb, sqshb_ino, &block,
119 &offset, sizeof(*sqshb_ino));
123 err = squashfs_new_inode(sb, inode, sqshb_ino);
127 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table;
128 offset = SQUASHFS_INODE_OFFSET(ino);
130 type = le16_to_cpu(sqshb_ino->inode_type);
132 case SQUASHFS_REG_TYPE: {
133 unsigned int frag_offset, frag;
136 struct squashfs_reg_inode *sqsh_ino = &squashfs_ino.reg;
138 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
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);
152 frag_blk = SQUASHFS_INVALID_BLK;
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;
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);
175 case SQUASHFS_LREG_TYPE: {
176 unsigned int frag_offset, frag;
179 struct squashfs_lreg_inode *sqsh_ino = &squashfs_ino.lreg;
181 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
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);
195 frag_blk = SQUASHFS_INVALID_BLK;
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;
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;
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);
222 case SQUASHFS_DIR_TYPE: {
223 struct squashfs_dir_inode *sqsh_ino = &squashfs_ino.dir;
225 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
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);
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));
246 case SQUASHFS_LDIR_TYPE: {
247 struct squashfs_ldir_inode *sqsh_ino = &squashfs_ino.ldir;
249 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
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);
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));
273 case SQUASHFS_SYMLINK_TYPE:
274 case SQUASHFS_LSYMLINK_TYPE: {
275 struct squashfs_symlink_inode *sqsh_ino = &squashfs_ino.symlink;
277 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
282 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
283 inode->i_size = le32_to_cpu(sqsh_ino->symlink_size);
284 inode->i_op = &squashfs_symlink_inode_ops;
285 inode_nohighmem(inode);
286 inode->i_data.a_ops = &squashfs_symlink_aops;
287 inode->i_mode |= S_IFLNK;
288 squashfs_i(inode)->start = block;
289 squashfs_i(inode)->offset = offset;
291 if (type == SQUASHFS_LSYMLINK_TYPE) {
294 err = squashfs_read_metadata(sb, NULL, &block,
295 &offset, inode->i_size);
298 err = squashfs_read_metadata(sb, &xattr, &block,
299 &offset, sizeof(xattr));
302 xattr_id = le32_to_cpu(xattr);
305 TRACE("Symbolic link inode %x:%x, start_block %llx, offset "
306 "%x\n", SQUASHFS_INODE_BLK(ino), offset,
310 case SQUASHFS_BLKDEV_TYPE:
311 case SQUASHFS_CHRDEV_TYPE: {
312 struct squashfs_dev_inode *sqsh_ino = &squashfs_ino.dev;
315 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
320 if (type == SQUASHFS_CHRDEV_TYPE)
321 inode->i_mode |= S_IFCHR;
323 inode->i_mode |= S_IFBLK;
324 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
325 rdev = le32_to_cpu(sqsh_ino->rdev);
326 init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));
328 TRACE("Device inode %x:%x, rdev %x\n",
329 SQUASHFS_INODE_BLK(ino), offset, rdev);
332 case SQUASHFS_LBLKDEV_TYPE:
333 case SQUASHFS_LCHRDEV_TYPE: {
334 struct squashfs_ldev_inode *sqsh_ino = &squashfs_ino.ldev;
337 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
342 if (type == SQUASHFS_LCHRDEV_TYPE)
343 inode->i_mode |= S_IFCHR;
345 inode->i_mode |= S_IFBLK;
346 xattr_id = le32_to_cpu(sqsh_ino->xattr);
347 inode->i_op = &squashfs_inode_ops;
348 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
349 rdev = le32_to_cpu(sqsh_ino->rdev);
350 init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));
352 TRACE("Device inode %x:%x, rdev %x\n",
353 SQUASHFS_INODE_BLK(ino), offset, rdev);
356 case SQUASHFS_FIFO_TYPE:
357 case SQUASHFS_SOCKET_TYPE: {
358 struct squashfs_ipc_inode *sqsh_ino = &squashfs_ino.ipc;
360 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
365 if (type == SQUASHFS_FIFO_TYPE)
366 inode->i_mode |= S_IFIFO;
368 inode->i_mode |= S_IFSOCK;
369 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
370 init_special_inode(inode, inode->i_mode, 0);
373 case SQUASHFS_LFIFO_TYPE:
374 case SQUASHFS_LSOCKET_TYPE: {
375 struct squashfs_lipc_inode *sqsh_ino = &squashfs_ino.lipc;
377 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
382 if (type == SQUASHFS_LFIFO_TYPE)
383 inode->i_mode |= S_IFIFO;
385 inode->i_mode |= S_IFSOCK;
386 xattr_id = le32_to_cpu(sqsh_ino->xattr);
387 inode->i_op = &squashfs_inode_ops;
388 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
389 init_special_inode(inode, inode->i_mode, 0);
393 ERROR("Unknown inode type %d in squashfs_iget!\n", type);
397 if (xattr_id != SQUASHFS_INVALID_XATTR && msblk->xattr_id_table) {
398 err = squashfs_xattr_lookup(sb, xattr_id,
399 &squashfs_i(inode)->xattr_count,
400 &squashfs_i(inode)->xattr_size,
401 &squashfs_i(inode)->xattr);
404 inode->i_blocks += ((squashfs_i(inode)->xattr_size - 1) >> 9)
407 squashfs_i(inode)->xattr_count = 0;
412 ERROR("Unable to read inode 0x%llx\n", ino);
417 const struct inode_operations squashfs_inode_ops = {
418 .listxattr = squashfs_listxattr