Commit | Line | Data |
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6545b246 PL |
1 | /* |
2 | * Squashfs - a compressed read only filesystem for Linux | |
3 | * | |
4 | * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 | |
5 | * Phillip Lougher <phillip@lougher.demon.co.uk> | |
6 | * | |
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> | |
67f66cc6 | 43 | #include <linux/xattr.h> |
6545b246 PL |
44 | |
45 | #include "squashfs_fs.h" | |
46 | #include "squashfs_fs_sb.h" | |
47 | #include "squashfs_fs_i.h" | |
48 | #include "squashfs.h" | |
01e5b4e4 | 49 | #include "xattr.h" |
6545b246 PL |
50 | |
51 | /* | |
52 | * Initialise VFS inode with the base inode information common to all | |
53 | * Squashfs inode types. Sqsh_ino contains the unswapped base inode | |
54 | * off disk. | |
55 | */ | |
56 | static int squashfs_new_inode(struct super_block *sb, struct inode *inode, | |
57 | struct squashfs_base_inode *sqsh_ino) | |
58 | { | |
59 | int err; | |
60 | ||
61 | err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->uid), &inode->i_uid); | |
62 | if (err) | |
63 | return err; | |
64 | ||
65 | err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->guid), &inode->i_gid); | |
66 | if (err) | |
67 | return err; | |
68 | ||
69 | inode->i_ino = le32_to_cpu(sqsh_ino->inode_number); | |
70 | inode->i_mtime.tv_sec = le32_to_cpu(sqsh_ino->mtime); | |
71 | inode->i_atime.tv_sec = inode->i_mtime.tv_sec; | |
72 | inode->i_ctime.tv_sec = inode->i_mtime.tv_sec; | |
73 | inode->i_mode = le16_to_cpu(sqsh_ino->mode); | |
74 | inode->i_size = 0; | |
75 | ||
76 | return err; | |
77 | } | |
78 | ||
79 | ||
80 | struct inode *squashfs_iget(struct super_block *sb, long long ino, | |
81 | unsigned int ino_number) | |
82 | { | |
83 | struct inode *inode = iget_locked(sb, ino_number); | |
84 | int err; | |
85 | ||
86 | TRACE("Entered squashfs_iget\n"); | |
87 | ||
88 | if (!inode) | |
89 | return ERR_PTR(-ENOMEM); | |
90 | if (!(inode->i_state & I_NEW)) | |
91 | return inode; | |
92 | ||
93 | err = squashfs_read_inode(inode, ino); | |
94 | if (err) { | |
95 | iget_failed(inode); | |
96 | return ERR_PTR(err); | |
97 | } | |
98 | ||
99 | unlock_new_inode(inode); | |
100 | return inode; | |
101 | } | |
102 | ||
103 | ||
104 | /* | |
105 | * Initialise VFS inode by reading inode from inode table (compressed | |
106 | * metadata). The format and amount of data read depends on type. | |
107 | */ | |
108 | int squashfs_read_inode(struct inode *inode, long long ino) | |
109 | { | |
110 | struct super_block *sb = inode->i_sb; | |
111 | struct squashfs_sb_info *msblk = sb->s_fs_info; | |
112 | u64 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table; | |
113 | int err, type, offset = SQUASHFS_INODE_OFFSET(ino); | |
114 | union squashfs_inode squashfs_ino; | |
115 | struct squashfs_base_inode *sqshb_ino = &squashfs_ino.base; | |
67f66cc6 | 116 | int xattr_id = SQUASHFS_INVALID_XATTR; |
6545b246 PL |
117 | |
118 | TRACE("Entered squashfs_read_inode\n"); | |
119 | ||
120 | /* | |
121 | * Read inode base common to all inode types. | |
122 | */ | |
123 | err = squashfs_read_metadata(sb, sqshb_ino, &block, | |
124 | &offset, sizeof(*sqshb_ino)); | |
125 | if (err < 0) | |
126 | goto failed_read; | |
127 | ||
128 | err = squashfs_new_inode(sb, inode, sqshb_ino); | |
129 | if (err) | |
130 | goto failed_read; | |
131 | ||
132 | block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table; | |
133 | offset = SQUASHFS_INODE_OFFSET(ino); | |
134 | ||
135 | type = le16_to_cpu(sqshb_ino->inode_type); | |
136 | switch (type) { | |
137 | case SQUASHFS_REG_TYPE: { | |
f4f8056a RK |
138 | unsigned int frag_offset, frag; |
139 | int frag_size; | |
6545b246 PL |
140 | u64 frag_blk; |
141 | struct squashfs_reg_inode *sqsh_ino = &squashfs_ino.reg; | |
142 | ||
143 | err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, | |
144 | sizeof(*sqsh_ino)); | |
145 | if (err < 0) | |
146 | goto failed_read; | |
147 | ||
148 | frag = le32_to_cpu(sqsh_ino->fragment); | |
149 | if (frag != SQUASHFS_INVALID_FRAG) { | |
150 | frag_offset = le32_to_cpu(sqsh_ino->offset); | |
151 | frag_size = squashfs_frag_lookup(sb, frag, &frag_blk); | |
152 | if (frag_size < 0) { | |
153 | err = frag_size; | |
154 | goto failed_read; | |
155 | } | |
156 | } else { | |
157 | frag_blk = SQUASHFS_INVALID_BLK; | |
158 | frag_size = 0; | |
159 | frag_offset = 0; | |
160 | } | |
161 | ||
162 | inode->i_nlink = 1; | |
163 | inode->i_size = le32_to_cpu(sqsh_ino->file_size); | |
164 | inode->i_fop = &generic_ro_fops; | |
165 | inode->i_mode |= S_IFREG; | |
166 | inode->i_blocks = ((inode->i_size - 1) >> 9) + 1; | |
167 | squashfs_i(inode)->fragment_block = frag_blk; | |
168 | squashfs_i(inode)->fragment_size = frag_size; | |
169 | squashfs_i(inode)->fragment_offset = frag_offset; | |
170 | squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block); | |
171 | squashfs_i(inode)->block_list_start = block; | |
172 | squashfs_i(inode)->offset = offset; | |
173 | inode->i_data.a_ops = &squashfs_aops; | |
174 | ||
175 | TRACE("File inode %x:%x, start_block %llx, block_list_start " | |
176 | "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino), | |
177 | offset, squashfs_i(inode)->start, block, offset); | |
178 | break; | |
179 | } | |
180 | case SQUASHFS_LREG_TYPE: { | |
f4f8056a RK |
181 | unsigned int frag_offset, frag; |
182 | int frag_size; | |
6545b246 PL |
183 | u64 frag_blk; |
184 | struct squashfs_lreg_inode *sqsh_ino = &squashfs_ino.lreg; | |
185 | ||
186 | err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, | |
187 | sizeof(*sqsh_ino)); | |
188 | if (err < 0) | |
189 | goto failed_read; | |
190 | ||
191 | frag = le32_to_cpu(sqsh_ino->fragment); | |
192 | if (frag != SQUASHFS_INVALID_FRAG) { | |
193 | frag_offset = le32_to_cpu(sqsh_ino->offset); | |
194 | frag_size = squashfs_frag_lookup(sb, frag, &frag_blk); | |
195 | if (frag_size < 0) { | |
196 | err = frag_size; | |
197 | goto failed_read; | |
198 | } | |
199 | } else { | |
200 | frag_blk = SQUASHFS_INVALID_BLK; | |
201 | frag_size = 0; | |
202 | frag_offset = 0; | |
203 | } | |
204 | ||
67f66cc6 | 205 | xattr_id = le32_to_cpu(sqsh_ino->xattr); |
6545b246 PL |
206 | inode->i_nlink = le32_to_cpu(sqsh_ino->nlink); |
207 | inode->i_size = le64_to_cpu(sqsh_ino->file_size); | |
67f66cc6 | 208 | inode->i_op = &squashfs_inode_ops; |
6545b246 PL |
209 | inode->i_fop = &generic_ro_fops; |
210 | inode->i_mode |= S_IFREG; | |
211 | inode->i_blocks = ((inode->i_size - | |
212 | le64_to_cpu(sqsh_ino->sparse) - 1) >> 9) + 1; | |
213 | ||
214 | squashfs_i(inode)->fragment_block = frag_blk; | |
215 | squashfs_i(inode)->fragment_size = frag_size; | |
216 | squashfs_i(inode)->fragment_offset = frag_offset; | |
217 | squashfs_i(inode)->start = le64_to_cpu(sqsh_ino->start_block); | |
218 | squashfs_i(inode)->block_list_start = block; | |
219 | squashfs_i(inode)->offset = offset; | |
220 | inode->i_data.a_ops = &squashfs_aops; | |
221 | ||
222 | TRACE("File inode %x:%x, start_block %llx, block_list_start " | |
223 | "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino), | |
224 | offset, squashfs_i(inode)->start, block, offset); | |
225 | break; | |
226 | } | |
227 | case SQUASHFS_DIR_TYPE: { | |
228 | struct squashfs_dir_inode *sqsh_ino = &squashfs_ino.dir; | |
229 | ||
230 | err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, | |
231 | sizeof(*sqsh_ino)); | |
232 | if (err < 0) | |
233 | goto failed_read; | |
234 | ||
235 | inode->i_nlink = le32_to_cpu(sqsh_ino->nlink); | |
236 | inode->i_size = le16_to_cpu(sqsh_ino->file_size); | |
237 | inode->i_op = &squashfs_dir_inode_ops; | |
238 | inode->i_fop = &squashfs_dir_ops; | |
239 | inode->i_mode |= S_IFDIR; | |
240 | squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block); | |
241 | squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset); | |
242 | squashfs_i(inode)->dir_idx_cnt = 0; | |
243 | squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode); | |
244 | ||
245 | TRACE("Directory inode %x:%x, start_block %llx, offset %x\n", | |
246 | SQUASHFS_INODE_BLK(ino), offset, | |
247 | squashfs_i(inode)->start, | |
248 | le16_to_cpu(sqsh_ino->offset)); | |
249 | break; | |
250 | } | |
251 | case SQUASHFS_LDIR_TYPE: { | |
252 | struct squashfs_ldir_inode *sqsh_ino = &squashfs_ino.ldir; | |
253 | ||
254 | err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, | |
255 | sizeof(*sqsh_ino)); | |
256 | if (err < 0) | |
257 | goto failed_read; | |
258 | ||
67f66cc6 | 259 | xattr_id = le32_to_cpu(sqsh_ino->xattr); |
6545b246 PL |
260 | inode->i_nlink = le32_to_cpu(sqsh_ino->nlink); |
261 | inode->i_size = le32_to_cpu(sqsh_ino->file_size); | |
262 | inode->i_op = &squashfs_dir_inode_ops; | |
263 | inode->i_fop = &squashfs_dir_ops; | |
264 | inode->i_mode |= S_IFDIR; | |
265 | squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block); | |
266 | squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset); | |
267 | squashfs_i(inode)->dir_idx_start = block; | |
268 | squashfs_i(inode)->dir_idx_offset = offset; | |
269 | squashfs_i(inode)->dir_idx_cnt = le16_to_cpu(sqsh_ino->i_count); | |
270 | squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode); | |
271 | ||
272 | TRACE("Long directory inode %x:%x, start_block %llx, offset " | |
273 | "%x\n", SQUASHFS_INODE_BLK(ino), offset, | |
274 | squashfs_i(inode)->start, | |
275 | le16_to_cpu(sqsh_ino->offset)); | |
276 | break; | |
277 | } | |
278 | case SQUASHFS_SYMLINK_TYPE: | |
279 | case SQUASHFS_LSYMLINK_TYPE: { | |
280 | struct squashfs_symlink_inode *sqsh_ino = &squashfs_ino.symlink; | |
281 | ||
282 | err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, | |
283 | sizeof(*sqsh_ino)); | |
284 | if (err < 0) | |
285 | goto failed_read; | |
286 | ||
287 | inode->i_nlink = le32_to_cpu(sqsh_ino->nlink); | |
288 | inode->i_size = le32_to_cpu(sqsh_ino->symlink_size); | |
67f66cc6 | 289 | inode->i_op = &squashfs_symlink_inode_ops; |
6545b246 PL |
290 | inode->i_data.a_ops = &squashfs_symlink_aops; |
291 | inode->i_mode |= S_IFLNK; | |
292 | squashfs_i(inode)->start = block; | |
293 | squashfs_i(inode)->offset = offset; | |
294 | ||
67f66cc6 PL |
295 | if (type == SQUASHFS_LSYMLINK_TYPE) { |
296 | __le32 xattr; | |
297 | ||
298 | err = squashfs_read_metadata(sb, NULL, &block, | |
299 | &offset, inode->i_size); | |
300 | if (err < 0) | |
301 | goto failed_read; | |
302 | err = squashfs_read_metadata(sb, &xattr, &block, | |
303 | &offset, sizeof(xattr)); | |
304 | if (err < 0) | |
305 | goto failed_read; | |
306 | xattr_id = le32_to_cpu(xattr); | |
307 | } | |
308 | ||
6545b246 PL |
309 | TRACE("Symbolic link inode %x:%x, start_block %llx, offset " |
310 | "%x\n", SQUASHFS_INODE_BLK(ino), offset, | |
311 | block, offset); | |
312 | break; | |
313 | } | |
314 | case SQUASHFS_BLKDEV_TYPE: | |
67f66cc6 | 315 | case SQUASHFS_CHRDEV_TYPE: { |
6545b246 PL |
316 | struct squashfs_dev_inode *sqsh_ino = &squashfs_ino.dev; |
317 | unsigned int rdev; | |
318 | ||
319 | err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, | |
320 | sizeof(*sqsh_ino)); | |
321 | if (err < 0) | |
322 | goto failed_read; | |
323 | ||
324 | if (type == SQUASHFS_CHRDEV_TYPE) | |
325 | inode->i_mode |= S_IFCHR; | |
326 | else | |
327 | inode->i_mode |= S_IFBLK; | |
328 | inode->i_nlink = le32_to_cpu(sqsh_ino->nlink); | |
329 | rdev = le32_to_cpu(sqsh_ino->rdev); | |
330 | init_special_inode(inode, inode->i_mode, new_decode_dev(rdev)); | |
331 | ||
332 | TRACE("Device inode %x:%x, rdev %x\n", | |
333 | SQUASHFS_INODE_BLK(ino), offset, rdev); | |
334 | break; | |
335 | } | |
67f66cc6 PL |
336 | case SQUASHFS_LBLKDEV_TYPE: |
337 | case SQUASHFS_LCHRDEV_TYPE: { | |
338 | struct squashfs_ldev_inode *sqsh_ino = &squashfs_ino.ldev; | |
339 | unsigned int rdev; | |
340 | ||
341 | err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, | |
342 | sizeof(*sqsh_ino)); | |
343 | if (err < 0) | |
344 | goto failed_read; | |
345 | ||
346 | if (type == SQUASHFS_LCHRDEV_TYPE) | |
347 | inode->i_mode |= S_IFCHR; | |
348 | else | |
349 | inode->i_mode |= S_IFBLK; | |
350 | xattr_id = le32_to_cpu(sqsh_ino->xattr); | |
351 | inode->i_op = &squashfs_inode_ops; | |
352 | inode->i_nlink = le32_to_cpu(sqsh_ino->nlink); | |
353 | rdev = le32_to_cpu(sqsh_ino->rdev); | |
354 | init_special_inode(inode, inode->i_mode, new_decode_dev(rdev)); | |
355 | ||
356 | TRACE("Device inode %x:%x, rdev %x\n", | |
357 | SQUASHFS_INODE_BLK(ino), offset, rdev); | |
358 | break; | |
359 | } | |
6545b246 | 360 | case SQUASHFS_FIFO_TYPE: |
67f66cc6 | 361 | case SQUASHFS_SOCKET_TYPE: { |
6545b246 PL |
362 | struct squashfs_ipc_inode *sqsh_ino = &squashfs_ino.ipc; |
363 | ||
364 | err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, | |
365 | sizeof(*sqsh_ino)); | |
366 | if (err < 0) | |
367 | goto failed_read; | |
368 | ||
369 | if (type == SQUASHFS_FIFO_TYPE) | |
370 | inode->i_mode |= S_IFIFO; | |
371 | else | |
372 | inode->i_mode |= S_IFSOCK; | |
373 | inode->i_nlink = le32_to_cpu(sqsh_ino->nlink); | |
374 | init_special_inode(inode, inode->i_mode, 0); | |
375 | break; | |
376 | } | |
67f66cc6 PL |
377 | case SQUASHFS_LFIFO_TYPE: |
378 | case SQUASHFS_LSOCKET_TYPE: { | |
379 | struct squashfs_lipc_inode *sqsh_ino = &squashfs_ino.lipc; | |
380 | ||
381 | err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, | |
382 | sizeof(*sqsh_ino)); | |
383 | if (err < 0) | |
384 | goto failed_read; | |
385 | ||
386 | if (type == SQUASHFS_LFIFO_TYPE) | |
387 | inode->i_mode |= S_IFIFO; | |
388 | else | |
389 | inode->i_mode |= S_IFSOCK; | |
390 | xattr_id = le32_to_cpu(sqsh_ino->xattr); | |
391 | inode->i_op = &squashfs_inode_ops; | |
392 | inode->i_nlink = le32_to_cpu(sqsh_ino->nlink); | |
393 | init_special_inode(inode, inode->i_mode, 0); | |
394 | break; | |
395 | } | |
6545b246 PL |
396 | default: |
397 | ERROR("Unknown inode type %d in squashfs_iget!\n", type); | |
398 | return -EINVAL; | |
399 | } | |
400 | ||
67f66cc6 PL |
401 | if (xattr_id != SQUASHFS_INVALID_XATTR && msblk->xattr_id_table) { |
402 | err = squashfs_xattr_lookup(sb, xattr_id, | |
403 | &squashfs_i(inode)->xattr_count, | |
404 | &squashfs_i(inode)->xattr_size, | |
405 | &squashfs_i(inode)->xattr); | |
406 | if (err < 0) | |
407 | goto failed_read; | |
408 | inode->i_blocks += ((squashfs_i(inode)->xattr_size - 1) >> 9) | |
409 | + 1; | |
410 | } else | |
411 | squashfs_i(inode)->xattr_count = 0; | |
412 | ||
6545b246 PL |
413 | return 0; |
414 | ||
415 | failed_read: | |
416 | ERROR("Unable to read inode 0x%llx\n", ino); | |
417 | return err; | |
418 | } | |
67f66cc6 PL |
419 | |
420 | ||
421 | const struct inode_operations squashfs_inode_ops = { | |
422 | .getxattr = generic_getxattr, | |
423 | .listxattr = squashfs_listxattr | |
424 | }; | |
425 |