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1 /* 1
2 * Squashfs - a compressed read only filesyste
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006,
5 * Phillip Lougher <phillip@lougher.demon.co.u
6 *
7 * This program is free software; you can redi
8 * modify it under the terms of the GNU Genera
9 * as published by the Free Software Foundatio
10 * or (at your option) any later version.
11 *
12 * This program is distributed in the hope tha
13 * but WITHOUT ANY WARRANTY; without even the
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR
15 * GNU General Public License for more details
16 *
17 * You should have received a copy of the GNU
18 * along with this program; if not, write to t
19 * Foundation, 51 Franklin Street, Fifth Floor
20 *
21 * inode.c
22 */
23
24 /*
25 * This file implements code to create and rea
26 *
27 * Inodes in Squashfs are identified by a 48-b
28 * location of the compressed metadata block c
29 * offset into that block where the inode is p
30 *
31 * To maximise compression there are different
32 * (regular file, directory, device, etc.), th
33 * varying with the type.
34 *
35 * To further maximise compression, two types
36 * directory inode are defined: inodes optimis
37 * regular files and directories, and extended
38 * information has to be stored.
39 */
40
41 #include <linux/fs.h>
42 #include <linux/vfs.h>
43 #include <linux/zlib.h>
44
45 #include "squashfs_fs.h"
46 #include "squashfs_fs_sb.h"
47 #include "squashfs_fs_i.h"
48 #include "squashfs.h"
49
50 /*
51 * Initialise VFS inode with the base inode in
52 * Squashfs inode types. Sqsh_ino contains th
53 * off disk.
54 */
55 static int squashfs_new_inode(struct super_blo
56 struct squashf
57 {
58 int err;
59
60 err = squashfs_get_id(sb, le16_to_cpu(
61 if (err)
62 return err;
63
64 err = squashfs_get_id(sb, le16_to_cpu(
65 if (err)
66 return err;
67
68 inode->i_ino = le32_to_cpu(sqsh_ino->i
69 inode->i_mtime.tv_sec = le32_to_cpu(sq
70 inode->i_atime.tv_sec = inode->i_mtime
71 inode->i_ctime.tv_sec = inode->i_mtime
72 inode->i_mode = le16_to_cpu(sqsh_ino->
73 inode->i_size = 0;
74
75 return err;
76 }
77
78
79 struct inode *squashfs_iget(struct super_block
80 unsigned int i
81 {
82 struct inode *inode = iget_locked(sb,
83 int err;
84
85 TRACE("Entered squashfs_iget\n");
86
87 if (!inode)
88 return ERR_PTR(-ENOMEM);
89 if (!(inode->i_state & I_NEW))
90 return inode;
91
92 err = squashfs_read_inode(inode, ino);
93 if (err) {
94 iget_failed(inode);
95 return ERR_PTR(err);
96 }
97
98 unlock_new_inode(inode);
99 return inode;
100 }
101
102
103 /*
104 * Initialise VFS inode by reading inode from
105 * metadata). The format and amount of data r
106 */
107 int squashfs_read_inode(struct inode *inode, l
108 {
109 struct super_block *sb = inode->i_sb;
110 struct squashfs_sb_info *msblk = sb->s
111 u64 block = SQUASHFS_INODE_BLK(ino) +
112 int err, type, offset = SQUASHFS_INODE
113 union squashfs_inode squashfs_ino;
114 struct squashfs_base_inode *sqshb_ino
115
116 TRACE("Entered squashfs_read_inode\n")
117
118 /*
119 * Read inode base common to all inode
120 */
121 err = squashfs_read_metadata(sb, sqshb
122 &offset, sizeo
123 if (err < 0)
124 goto failed_read;
125
126 err = squashfs_new_inode(sb, inode, sq
127 if (err)
128 goto failed_read;
129
130 block = SQUASHFS_INODE_BLK(ino) + msbl
131 offset = SQUASHFS_INODE_OFFSET(ino);
132
133 type = le16_to_cpu(sqshb_ino->inode_ty
134 switch (type) {
135 case SQUASHFS_REG_TYPE: {
136 unsigned int frag_offset, frag
137 int frag_size;
138 u64 frag_blk;
139 struct squashfs_reg_inode *sqs
140
141 err = squashfs_read_metadata(s
142
143 if (err < 0)
144 goto failed_read;
145
146 frag = le32_to_cpu(sqsh_ino->f
147 if (frag != SQUASHFS_INVALID_F
148 frag_offset = le32_to_
149 frag_size = squashfs_f
150 if (frag_size < 0) {
151 err = frag_siz
152 goto failed_re
153 }
154 } else {
155 frag_blk = SQUASHFS_IN
156 frag_size = 0;
157 frag_offset = 0;
158 }
159
160 inode->i_nlink = 1;
161 inode->i_size = le32_to_cpu(sq
162 inode->i_fop = &generic_ro_fop
163 inode->i_mode |= S_IFREG;
164 inode->i_blocks = ((inode->i_s
165 squashfs_i(inode)->fragment_bl
166 squashfs_i(inode)->fragment_si
167 squashfs_i(inode)->fragment_of
168 squashfs_i(inode)->start = le3
169 squashfs_i(inode)->block_list_
170 squashfs_i(inode)->offset = of
171 inode->i_data.a_ops = &squashf
172
173 TRACE("File inode %x:%x, start
174 "%llx, offset %x\n", S
175 offset, squashfs_i(ino
176 break;
177 }
178 case SQUASHFS_LREG_TYPE: {
179 unsigned int frag_offset, frag
180 int frag_size;
181 u64 frag_blk;
182 struct squashfs_lreg_inode *sq
183
184 err = squashfs_read_metadata(s
185
186 if (err < 0)
187 goto failed_read;
188
189 frag = le32_to_cpu(sqsh_ino->f
190 if (frag != SQUASHFS_INVALID_F
191 frag_offset = le32_to_
192 frag_size = squashfs_f
193 if (frag_size < 0) {
194 err = frag_siz
195 goto failed_re
196 }
197 } else {
198 frag_blk = SQUASHFS_IN
199 frag_size = 0;
200 frag_offset = 0;
201 }
202
203 inode->i_nlink = le32_to_cpu(s
204 inode->i_size = le64_to_cpu(sq
205 inode->i_fop = &generic_ro_fop
206 inode->i_mode |= S_IFREG;
207 inode->i_blocks = ((inode->i_s
208 le64_to_cpu(sq
209
210 squashfs_i(inode)->fragment_bl
211 squashfs_i(inode)->fragment_si
212 squashfs_i(inode)->fragment_of
213 squashfs_i(inode)->start = le6
214 squashfs_i(inode)->block_list_
215 squashfs_i(inode)->offset = of
216 inode->i_data.a_ops = &squashf
217
218 TRACE("File inode %x:%x, start
219 "%llx, offset %x\n", S
220 offset, squashfs_i(ino
221 break;
222 }
223 case SQUASHFS_DIR_TYPE: {
224 struct squashfs_dir_inode *sqs
225
226 err = squashfs_read_metadata(s
227 sizeof(*sqsh_i
228 if (err < 0)
229 goto failed_read;
230
231 inode->i_nlink = le32_to_cpu(s
232 inode->i_size = le16_to_cpu(sq
233 inode->i_op = &squashfs_dir_in
234 inode->i_fop = &squashfs_dir_o
235 inode->i_mode |= S_IFDIR;
236 squashfs_i(inode)->start = le3
237 squashfs_i(inode)->offset = le
238 squashfs_i(inode)->dir_idx_cnt
239 squashfs_i(inode)->parent = le
240
241 TRACE("Directory inode %x:%x,
242 SQUASHFS_INODE
243 squashfs_i(ino
244 le16_to_cpu(sq
245 break;
246 }
247 case SQUASHFS_LDIR_TYPE: {
248 struct squashfs_ldir_inode *sq
249
250 err = squashfs_read_metadata(s
251 sizeof(*sqsh_i
252 if (err < 0)
253 goto failed_read;
254
255 inode->i_nlink = le32_to_cpu(s
256 inode->i_size = le32_to_cpu(sq
257 inode->i_op = &squashfs_dir_in
258 inode->i_fop = &squashfs_dir_o
259 inode->i_mode |= S_IFDIR;
260 squashfs_i(inode)->start = le3
261 squashfs_i(inode)->offset = le
262 squashfs_i(inode)->dir_idx_sta
263 squashfs_i(inode)->dir_idx_off
264 squashfs_i(inode)->dir_idx_cnt
265 squashfs_i(inode)->parent = le
266
267 TRACE("Long directory inode %x
268 "%x\n", SQUASH
269 squashfs_i(ino
270 le16_to_cpu(sq
271 break;
272 }
273 case SQUASHFS_SYMLINK_TYPE:
274 case SQUASHFS_LSYMLINK_TYPE: {
275 struct squashfs_symlink_inode
276
277 err = squashfs_read_metadata(s
278 sizeof(*sqsh_i
279 if (err < 0)
280 goto failed_read;
281
282 inode->i_nlink = le32_to_cpu(s
283 inode->i_size = le32_to_cpu(sq
284 inode->i_op = &page_symlink_in
285 inode->i_data.a_ops = &squashf
286 inode->i_mode |= S_IFLNK;
287 squashfs_i(inode)->start = blo
288 squashfs_i(inode)->offset = of
289
290 TRACE("Symbolic link inode %x:
291 "%x\n", SQUASH
292 block, offset)
293 break;
294 }
295 case SQUASHFS_BLKDEV_TYPE:
296 case SQUASHFS_CHRDEV_TYPE:
297 case SQUASHFS_LBLKDEV_TYPE:
298 case SQUASHFS_LCHRDEV_TYPE: {
299 struct squashfs_dev_inode *sqs
300 unsigned int rdev;
301
302 err = squashfs_read_metadata(s
303 sizeof(*sqsh_i
304 if (err < 0)
305 goto failed_read;
306
307 if (type == SQUASHFS_CHRDEV_TY
308 inode->i_mode |= S_IFC
309 else
310 inode->i_mode |= S_IFB
311 inode->i_nlink = le32_to_cpu(s
312 rdev = le32_to_cpu(sqsh_ino->r
313 init_special_inode(inode, inod
314
315 TRACE("Device inode %x:%x, rde
316 SQUASHFS_INODE
317 break;
318 }
319 case SQUASHFS_FIFO_TYPE:
320 case SQUASHFS_SOCKET_TYPE:
321 case SQUASHFS_LFIFO_TYPE:
322 case SQUASHFS_LSOCKET_TYPE: {
323 struct squashfs_ipc_inode *sqs
324
325 err = squashfs_read_metadata(s
326 sizeof(*sqsh_i
327 if (err < 0)
328 goto failed_read;
329
330 if (type == SQUASHFS_FIFO_TYPE
331 inode->i_mode |= S_IFI
332 else
333 inode->i_mode |= S_IFS
334 inode->i_nlink = le32_to_cpu(s
335 init_special_inode(inode, inod
336 break;
337 }
338 default:
339 ERROR("Unknown inode type %d i
340 return -EINVAL;
341 }
342
343 return 0;
344
345 failed_read:
346 ERROR("Unable to read inode 0x%llx\n",
347 return err;
348 }
349
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