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Phillip Lougher6545b242009-01-05 08:46:22 +00001/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
Phillip Lougherd7f2ff62011-05-26 10:39:56 +01005 * Phillip Lougher <phillip@squashfs.org.uk>
Phillip Lougher6545b242009-01-05 08:46:22 +00006 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2,
10 * or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 *
21 * inode.c
22 */
23
24/*
25 * This file implements code to create and read inodes from disk.
26 *
27 * Inodes in Squashfs are identified by a 48-bit inode which encodes the
28 * location of the compressed metadata block containing the inode, and the byte
29 * offset into that block where the inode is placed (<block, offset>).
30 *
31 * To maximise compression there are different inodes for each file type
32 * (regular file, directory, device, etc.), the inode contents and length
33 * varying with the type.
34 *
35 * To further maximise compression, two types of regular file inode and
36 * directory inode are defined: inodes optimised for frequently occurring
37 * regular files and directories, and extended types where extra
38 * information has to be stored.
39 */
40
41#include <linux/fs.h>
42#include <linux/vfs.h>
Phillip Lougher67f66cc2010-05-17 04:06:56 +010043#include <linux/xattr.h>
Al Viro21fc61c2015-11-17 01:07:57 -050044#include <linux/pagemap.h>
Phillip Lougher6545b242009-01-05 08:46:22 +000045
46#include "squashfs_fs.h"
47#include "squashfs_fs_sb.h"
48#include "squashfs_fs_i.h"
49#include "squashfs.h"
Phillip Lougher01e5b4e2010-05-17 19:39:02 +010050#include "xattr.h"
Phillip Lougher6545b242009-01-05 08:46:22 +000051
52/*
53 * Initialise VFS inode with the base inode information common to all
54 * Squashfs inode types. Sqsh_ino contains the unswapped base inode
55 * off disk.
56 */
57static int squashfs_new_inode(struct super_block *sb, struct inode *inode,
58 struct squashfs_base_inode *sqsh_ino)
59{
Eric W. Biederman61293ee2012-02-10 12:14:27 -080060 uid_t i_uid;
61 gid_t i_gid;
Phillip Lougher6545b242009-01-05 08:46:22 +000062 int err;
63
Eric W. Biederman61293ee2012-02-10 12:14:27 -080064 err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->uid), &i_uid);
Phillip Lougher6545b242009-01-05 08:46:22 +000065 if (err)
66 return err;
67
Eric W. Biederman61293ee2012-02-10 12:14:27 -080068 err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->guid), &i_gid);
Phillip Lougher6545b242009-01-05 08:46:22 +000069 if (err)
70 return err;
71
Eric W. Biederman61293ee2012-02-10 12:14:27 -080072 i_uid_write(inode, i_uid);
73 i_gid_write(inode, i_gid);
Phillip Lougher6545b242009-01-05 08:46:22 +000074 inode->i_ino = le32_to_cpu(sqsh_ino->inode_number);
75 inode->i_mtime.tv_sec = le32_to_cpu(sqsh_ino->mtime);
76 inode->i_atime.tv_sec = inode->i_mtime.tv_sec;
77 inode->i_ctime.tv_sec = inode->i_mtime.tv_sec;
78 inode->i_mode = le16_to_cpu(sqsh_ino->mode);
79 inode->i_size = 0;
80
81 return err;
82}
83
84
85struct inode *squashfs_iget(struct super_block *sb, long long ino,
86 unsigned int ino_number)
87{
88 struct inode *inode = iget_locked(sb, ino_number);
89 int err;
90
91 TRACE("Entered squashfs_iget\n");
92
93 if (!inode)
94 return ERR_PTR(-ENOMEM);
95 if (!(inode->i_state & I_NEW))
96 return inode;
97
98 err = squashfs_read_inode(inode, ino);
99 if (err) {
100 iget_failed(inode);
101 return ERR_PTR(err);
102 }
103
104 unlock_new_inode(inode);
105 return inode;
106}
107
108
109/*
110 * Initialise VFS inode by reading inode from inode table (compressed
111 * metadata). The format and amount of data read depends on type.
112 */
113int squashfs_read_inode(struct inode *inode, long long ino)
114{
115 struct super_block *sb = inode->i_sb;
116 struct squashfs_sb_info *msblk = sb->s_fs_info;
117 u64 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table;
118 int err, type, offset = SQUASHFS_INODE_OFFSET(ino);
119 union squashfs_inode squashfs_ino;
120 struct squashfs_base_inode *sqshb_ino = &squashfs_ino.base;
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100121 int xattr_id = SQUASHFS_INVALID_XATTR;
Phillip Lougher6545b242009-01-05 08:46:22 +0000122
123 TRACE("Entered squashfs_read_inode\n");
124
125 /*
126 * Read inode base common to all inode types.
127 */
128 err = squashfs_read_metadata(sb, sqshb_ino, &block,
129 &offset, sizeof(*sqshb_ino));
130 if (err < 0)
131 goto failed_read;
132
133 err = squashfs_new_inode(sb, inode, sqshb_ino);
134 if (err)
135 goto failed_read;
136
137 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table;
138 offset = SQUASHFS_INODE_OFFSET(ino);
139
140 type = le16_to_cpu(sqshb_ino->inode_type);
141 switch (type) {
142 case SQUASHFS_REG_TYPE: {
Roel Kluinf4f80562009-03-05 00:55:31 +0000143 unsigned int frag_offset, frag;
144 int frag_size;
Phillip Lougher6545b242009-01-05 08:46:22 +0000145 u64 frag_blk;
146 struct squashfs_reg_inode *sqsh_ino = &squashfs_ino.reg;
147
148 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
149 sizeof(*sqsh_ino));
150 if (err < 0)
151 goto failed_read;
152
153 frag = le32_to_cpu(sqsh_ino->fragment);
154 if (frag != SQUASHFS_INVALID_FRAG) {
155 frag_offset = le32_to_cpu(sqsh_ino->offset);
156 frag_size = squashfs_frag_lookup(sb, frag, &frag_blk);
157 if (frag_size < 0) {
158 err = frag_size;
159 goto failed_read;
160 }
161 } else {
162 frag_blk = SQUASHFS_INVALID_BLK;
163 frag_size = 0;
164 frag_offset = 0;
165 }
166
Miklos Szeredibfe86842011-10-28 14:13:29 +0200167 set_nlink(inode, 1);
Phillip Lougher6545b242009-01-05 08:46:22 +0000168 inode->i_size = le32_to_cpu(sqsh_ino->file_size);
169 inode->i_fop = &generic_ro_fops;
170 inode->i_mode |= S_IFREG;
171 inode->i_blocks = ((inode->i_size - 1) >> 9) + 1;
172 squashfs_i(inode)->fragment_block = frag_blk;
173 squashfs_i(inode)->fragment_size = frag_size;
174 squashfs_i(inode)->fragment_offset = frag_offset;
175 squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);
176 squashfs_i(inode)->block_list_start = block;
177 squashfs_i(inode)->offset = offset;
178 inode->i_data.a_ops = &squashfs_aops;
179
180 TRACE("File inode %x:%x, start_block %llx, block_list_start "
181 "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino),
182 offset, squashfs_i(inode)->start, block, offset);
183 break;
184 }
185 case SQUASHFS_LREG_TYPE: {
Roel Kluinf4f80562009-03-05 00:55:31 +0000186 unsigned int frag_offset, frag;
187 int frag_size;
Phillip Lougher6545b242009-01-05 08:46:22 +0000188 u64 frag_blk;
189 struct squashfs_lreg_inode *sqsh_ino = &squashfs_ino.lreg;
190
191 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
192 sizeof(*sqsh_ino));
193 if (err < 0)
194 goto failed_read;
195
196 frag = le32_to_cpu(sqsh_ino->fragment);
197 if (frag != SQUASHFS_INVALID_FRAG) {
198 frag_offset = le32_to_cpu(sqsh_ino->offset);
199 frag_size = squashfs_frag_lookup(sb, frag, &frag_blk);
200 if (frag_size < 0) {
201 err = frag_size;
202 goto failed_read;
203 }
204 } else {
205 frag_blk = SQUASHFS_INVALID_BLK;
206 frag_size = 0;
207 frag_offset = 0;
208 }
209
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100210 xattr_id = le32_to_cpu(sqsh_ino->xattr);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200211 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
Phillip Lougher6545b242009-01-05 08:46:22 +0000212 inode->i_size = le64_to_cpu(sqsh_ino->file_size);
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100213 inode->i_op = &squashfs_inode_ops;
Phillip Lougher6545b242009-01-05 08:46:22 +0000214 inode->i_fop = &generic_ro_fops;
215 inode->i_mode |= S_IFREG;
Phillip Lougher3d4a1c82012-01-03 02:58:13 +0000216 inode->i_blocks = (inode->i_size -
217 le64_to_cpu(sqsh_ino->sparse) + 511) >> 9;
Phillip Lougher6545b242009-01-05 08:46:22 +0000218
219 squashfs_i(inode)->fragment_block = frag_blk;
220 squashfs_i(inode)->fragment_size = frag_size;
221 squashfs_i(inode)->fragment_offset = frag_offset;
222 squashfs_i(inode)->start = le64_to_cpu(sqsh_ino->start_block);
223 squashfs_i(inode)->block_list_start = block;
224 squashfs_i(inode)->offset = offset;
225 inode->i_data.a_ops = &squashfs_aops;
226
227 TRACE("File inode %x:%x, start_block %llx, block_list_start "
228 "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino),
229 offset, squashfs_i(inode)->start, block, offset);
230 break;
231 }
232 case SQUASHFS_DIR_TYPE: {
233 struct squashfs_dir_inode *sqsh_ino = &squashfs_ino.dir;
234
235 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
236 sizeof(*sqsh_ino));
237 if (err < 0)
238 goto failed_read;
239
Miklos Szeredibfe86842011-10-28 14:13:29 +0200240 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
Phillip Lougher6545b242009-01-05 08:46:22 +0000241 inode->i_size = le16_to_cpu(sqsh_ino->file_size);
242 inode->i_op = &squashfs_dir_inode_ops;
243 inode->i_fop = &squashfs_dir_ops;
244 inode->i_mode |= S_IFDIR;
245 squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);
246 squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset);
247 squashfs_i(inode)->dir_idx_cnt = 0;
248 squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode);
249
250 TRACE("Directory inode %x:%x, start_block %llx, offset %x\n",
251 SQUASHFS_INODE_BLK(ino), offset,
252 squashfs_i(inode)->start,
253 le16_to_cpu(sqsh_ino->offset));
254 break;
255 }
256 case SQUASHFS_LDIR_TYPE: {
257 struct squashfs_ldir_inode *sqsh_ino = &squashfs_ino.ldir;
258
259 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
260 sizeof(*sqsh_ino));
261 if (err < 0)
262 goto failed_read;
263
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100264 xattr_id = le32_to_cpu(sqsh_ino->xattr);
Miklos Szeredibfe86842011-10-28 14:13:29 +0200265 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
Phillip Lougher6545b242009-01-05 08:46:22 +0000266 inode->i_size = le32_to_cpu(sqsh_ino->file_size);
267 inode->i_op = &squashfs_dir_inode_ops;
268 inode->i_fop = &squashfs_dir_ops;
269 inode->i_mode |= S_IFDIR;
270 squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);
271 squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset);
272 squashfs_i(inode)->dir_idx_start = block;
273 squashfs_i(inode)->dir_idx_offset = offset;
274 squashfs_i(inode)->dir_idx_cnt = le16_to_cpu(sqsh_ino->i_count);
275 squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode);
276
277 TRACE("Long directory inode %x:%x, start_block %llx, offset "
278 "%x\n", SQUASHFS_INODE_BLK(ino), offset,
279 squashfs_i(inode)->start,
280 le16_to_cpu(sqsh_ino->offset));
281 break;
282 }
283 case SQUASHFS_SYMLINK_TYPE:
284 case SQUASHFS_LSYMLINK_TYPE: {
285 struct squashfs_symlink_inode *sqsh_ino = &squashfs_ino.symlink;
286
287 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
288 sizeof(*sqsh_ino));
289 if (err < 0)
290 goto failed_read;
291
Miklos Szeredibfe86842011-10-28 14:13:29 +0200292 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
Phillip Lougher6545b242009-01-05 08:46:22 +0000293 inode->i_size = le32_to_cpu(sqsh_ino->symlink_size);
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100294 inode->i_op = &squashfs_symlink_inode_ops;
Al Viro21fc61c2015-11-17 01:07:57 -0500295 inode_nohighmem(inode);
Phillip Lougher6545b242009-01-05 08:46:22 +0000296 inode->i_data.a_ops = &squashfs_symlink_aops;
297 inode->i_mode |= S_IFLNK;
298 squashfs_i(inode)->start = block;
299 squashfs_i(inode)->offset = offset;
300
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100301 if (type == SQUASHFS_LSYMLINK_TYPE) {
302 __le32 xattr;
303
304 err = squashfs_read_metadata(sb, NULL, &block,
305 &offset, inode->i_size);
306 if (err < 0)
307 goto failed_read;
308 err = squashfs_read_metadata(sb, &xattr, &block,
309 &offset, sizeof(xattr));
310 if (err < 0)
311 goto failed_read;
312 xattr_id = le32_to_cpu(xattr);
313 }
314
Phillip Lougher6545b242009-01-05 08:46:22 +0000315 TRACE("Symbolic link inode %x:%x, start_block %llx, offset "
316 "%x\n", SQUASHFS_INODE_BLK(ino), offset,
317 block, offset);
318 break;
319 }
320 case SQUASHFS_BLKDEV_TYPE:
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100321 case SQUASHFS_CHRDEV_TYPE: {
Phillip Lougher6545b242009-01-05 08:46:22 +0000322 struct squashfs_dev_inode *sqsh_ino = &squashfs_ino.dev;
323 unsigned int rdev;
324
325 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
326 sizeof(*sqsh_ino));
327 if (err < 0)
328 goto failed_read;
329
330 if (type == SQUASHFS_CHRDEV_TYPE)
331 inode->i_mode |= S_IFCHR;
332 else
333 inode->i_mode |= S_IFBLK;
Miklos Szeredibfe86842011-10-28 14:13:29 +0200334 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
Phillip Lougher6545b242009-01-05 08:46:22 +0000335 rdev = le32_to_cpu(sqsh_ino->rdev);
336 init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));
337
338 TRACE("Device inode %x:%x, rdev %x\n",
339 SQUASHFS_INODE_BLK(ino), offset, rdev);
340 break;
341 }
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100342 case SQUASHFS_LBLKDEV_TYPE:
343 case SQUASHFS_LCHRDEV_TYPE: {
344 struct squashfs_ldev_inode *sqsh_ino = &squashfs_ino.ldev;
345 unsigned int rdev;
346
347 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
348 sizeof(*sqsh_ino));
349 if (err < 0)
350 goto failed_read;
351
352 if (type == SQUASHFS_LCHRDEV_TYPE)
353 inode->i_mode |= S_IFCHR;
354 else
355 inode->i_mode |= S_IFBLK;
356 xattr_id = le32_to_cpu(sqsh_ino->xattr);
357 inode->i_op = &squashfs_inode_ops;
Miklos Szeredibfe86842011-10-28 14:13:29 +0200358 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100359 rdev = le32_to_cpu(sqsh_ino->rdev);
360 init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));
361
362 TRACE("Device inode %x:%x, rdev %x\n",
363 SQUASHFS_INODE_BLK(ino), offset, rdev);
364 break;
365 }
Phillip Lougher6545b242009-01-05 08:46:22 +0000366 case SQUASHFS_FIFO_TYPE:
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100367 case SQUASHFS_SOCKET_TYPE: {
Phillip Lougher6545b242009-01-05 08:46:22 +0000368 struct squashfs_ipc_inode *sqsh_ino = &squashfs_ino.ipc;
369
370 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
371 sizeof(*sqsh_ino));
372 if (err < 0)
373 goto failed_read;
374
375 if (type == SQUASHFS_FIFO_TYPE)
376 inode->i_mode |= S_IFIFO;
377 else
378 inode->i_mode |= S_IFSOCK;
Miklos Szeredibfe86842011-10-28 14:13:29 +0200379 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
Phillip Lougher6545b242009-01-05 08:46:22 +0000380 init_special_inode(inode, inode->i_mode, 0);
381 break;
382 }
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100383 case SQUASHFS_LFIFO_TYPE:
384 case SQUASHFS_LSOCKET_TYPE: {
385 struct squashfs_lipc_inode *sqsh_ino = &squashfs_ino.lipc;
386
387 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
388 sizeof(*sqsh_ino));
389 if (err < 0)
390 goto failed_read;
391
392 if (type == SQUASHFS_LFIFO_TYPE)
393 inode->i_mode |= S_IFIFO;
394 else
395 inode->i_mode |= S_IFSOCK;
396 xattr_id = le32_to_cpu(sqsh_ino->xattr);
397 inode->i_op = &squashfs_inode_ops;
Miklos Szeredibfe86842011-10-28 14:13:29 +0200398 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100399 init_special_inode(inode, inode->i_mode, 0);
400 break;
401 }
Phillip Lougher6545b242009-01-05 08:46:22 +0000402 default:
403 ERROR("Unknown inode type %d in squashfs_iget!\n", type);
404 return -EINVAL;
405 }
406
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100407 if (xattr_id != SQUASHFS_INVALID_XATTR && msblk->xattr_id_table) {
408 err = squashfs_xattr_lookup(sb, xattr_id,
409 &squashfs_i(inode)->xattr_count,
410 &squashfs_i(inode)->xattr_size,
411 &squashfs_i(inode)->xattr);
412 if (err < 0)
413 goto failed_read;
414 inode->i_blocks += ((squashfs_i(inode)->xattr_size - 1) >> 9)
415 + 1;
416 } else
417 squashfs_i(inode)->xattr_count = 0;
418
Phillip Lougher6545b242009-01-05 08:46:22 +0000419 return 0;
420
421failed_read:
422 ERROR("Unable to read inode 0x%llx\n", ino);
423 return err;
424}
Phillip Lougher67f66cc2010-05-17 04:06:56 +0100425
426
427const struct inode_operations squashfs_inode_ops = {
428 .getxattr = generic_getxattr,
429 .listxattr = squashfs_listxattr
430};
431