fork: report pid reservation failure properly
[linux-2.6-block.git] / fs / squashfs / inode.c
CommitLineData
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1/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
d7f2ff67 5 * Phillip Lougher <phillip@squashfs.org.uk>
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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>
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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"
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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 */
56static int squashfs_new_inode(struct super_block *sb, struct inode *inode,
57 struct squashfs_base_inode *sqsh_ino)
58{
61293ee2
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59 uid_t i_uid;
60 gid_t i_gid;
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61 int err;
62
61293ee2 63 err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->uid), &i_uid);
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64 if (err)
65 return err;
66
61293ee2 67 err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->guid), &i_gid);
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68 if (err)
69 return err;
70
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71 i_uid_write(inode, i_uid);
72 i_gid_write(inode, i_gid);
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73 inode->i_ino = le32_to_cpu(sqsh_ino->inode_number);
74 inode->i_mtime.tv_sec = le32_to_cpu(sqsh_ino->mtime);
75 inode->i_atime.tv_sec = inode->i_mtime.tv_sec;
76 inode->i_ctime.tv_sec = inode->i_mtime.tv_sec;
77 inode->i_mode = le16_to_cpu(sqsh_ino->mode);
78 inode->i_size = 0;
79
80 return err;
81}
82
83
84struct inode *squashfs_iget(struct super_block *sb, long long ino,
85 unsigned int ino_number)
86{
87 struct inode *inode = iget_locked(sb, ino_number);
88 int err;
89
90 TRACE("Entered squashfs_iget\n");
91
92 if (!inode)
93 return ERR_PTR(-ENOMEM);
94 if (!(inode->i_state & I_NEW))
95 return inode;
96
97 err = squashfs_read_inode(inode, ino);
98 if (err) {
99 iget_failed(inode);
100 return ERR_PTR(err);
101 }
102
103 unlock_new_inode(inode);
104 return inode;
105}
106
107
108/*
109 * Initialise VFS inode by reading inode from inode table (compressed
110 * metadata). The format and amount of data read depends on type.
111 */
112int squashfs_read_inode(struct inode *inode, long long ino)
113{
114 struct super_block *sb = inode->i_sb;
115 struct squashfs_sb_info *msblk = sb->s_fs_info;
116 u64 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table;
117 int err, type, offset = SQUASHFS_INODE_OFFSET(ino);
118 union squashfs_inode squashfs_ino;
119 struct squashfs_base_inode *sqshb_ino = &squashfs_ino.base;
67f66cc6 120 int xattr_id = SQUASHFS_INVALID_XATTR;
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121
122 TRACE("Entered squashfs_read_inode\n");
123
124 /*
125 * Read inode base common to all inode types.
126 */
127 err = squashfs_read_metadata(sb, sqshb_ino, &block,
128 &offset, sizeof(*sqshb_ino));
129 if (err < 0)
130 goto failed_read;
131
132 err = squashfs_new_inode(sb, inode, sqshb_ino);
133 if (err)
134 goto failed_read;
135
136 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table;
137 offset = SQUASHFS_INODE_OFFSET(ino);
138
139 type = le16_to_cpu(sqshb_ino->inode_type);
140 switch (type) {
141 case SQUASHFS_REG_TYPE: {
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142 unsigned int frag_offset, frag;
143 int frag_size;
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144 u64 frag_blk;
145 struct squashfs_reg_inode *sqsh_ino = &squashfs_ino.reg;
146
147 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
148 sizeof(*sqsh_ino));
149 if (err < 0)
150 goto failed_read;
151
152 frag = le32_to_cpu(sqsh_ino->fragment);
153 if (frag != SQUASHFS_INVALID_FRAG) {
154 frag_offset = le32_to_cpu(sqsh_ino->offset);
155 frag_size = squashfs_frag_lookup(sb, frag, &frag_blk);
156 if (frag_size < 0) {
157 err = frag_size;
158 goto failed_read;
159 }
160 } else {
161 frag_blk = SQUASHFS_INVALID_BLK;
162 frag_size = 0;
163 frag_offset = 0;
164 }
165
bfe86848 166 set_nlink(inode, 1);
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167 inode->i_size = le32_to_cpu(sqsh_ino->file_size);
168 inode->i_fop = &generic_ro_fops;
169 inode->i_mode |= S_IFREG;
170 inode->i_blocks = ((inode->i_size - 1) >> 9) + 1;
171 squashfs_i(inode)->fragment_block = frag_blk;
172 squashfs_i(inode)->fragment_size = frag_size;
173 squashfs_i(inode)->fragment_offset = frag_offset;
174 squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);
175 squashfs_i(inode)->block_list_start = block;
176 squashfs_i(inode)->offset = offset;
177 inode->i_data.a_ops = &squashfs_aops;
178
179 TRACE("File inode %x:%x, start_block %llx, block_list_start "
180 "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino),
181 offset, squashfs_i(inode)->start, block, offset);
182 break;
183 }
184 case SQUASHFS_LREG_TYPE: {
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185 unsigned int frag_offset, frag;
186 int frag_size;
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187 u64 frag_blk;
188 struct squashfs_lreg_inode *sqsh_ino = &squashfs_ino.lreg;
189
190 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
191 sizeof(*sqsh_ino));
192 if (err < 0)
193 goto failed_read;
194
195 frag = le32_to_cpu(sqsh_ino->fragment);
196 if (frag != SQUASHFS_INVALID_FRAG) {
197 frag_offset = le32_to_cpu(sqsh_ino->offset);
198 frag_size = squashfs_frag_lookup(sb, frag, &frag_blk);
199 if (frag_size < 0) {
200 err = frag_size;
201 goto failed_read;
202 }
203 } else {
204 frag_blk = SQUASHFS_INVALID_BLK;
205 frag_size = 0;
206 frag_offset = 0;
207 }
208
67f66cc6 209 xattr_id = le32_to_cpu(sqsh_ino->xattr);
bfe86848 210 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
6545b246 211 inode->i_size = le64_to_cpu(sqsh_ino->file_size);
67f66cc6 212 inode->i_op = &squashfs_inode_ops;
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213 inode->i_fop = &generic_ro_fops;
214 inode->i_mode |= S_IFREG;
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PL
215 inode->i_blocks = (inode->i_size -
216 le64_to_cpu(sqsh_ino->sparse) + 511) >> 9;
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217
218 squashfs_i(inode)->fragment_block = frag_blk;
219 squashfs_i(inode)->fragment_size = frag_size;
220 squashfs_i(inode)->fragment_offset = frag_offset;
221 squashfs_i(inode)->start = le64_to_cpu(sqsh_ino->start_block);
222 squashfs_i(inode)->block_list_start = block;
223 squashfs_i(inode)->offset = offset;
224 inode->i_data.a_ops = &squashfs_aops;
225
226 TRACE("File inode %x:%x, start_block %llx, block_list_start "
227 "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino),
228 offset, squashfs_i(inode)->start, block, offset);
229 break;
230 }
231 case SQUASHFS_DIR_TYPE: {
232 struct squashfs_dir_inode *sqsh_ino = &squashfs_ino.dir;
233
234 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
235 sizeof(*sqsh_ino));
236 if (err < 0)
237 goto failed_read;
238
bfe86848 239 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
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PL
240 inode->i_size = le16_to_cpu(sqsh_ino->file_size);
241 inode->i_op = &squashfs_dir_inode_ops;
242 inode->i_fop = &squashfs_dir_ops;
243 inode->i_mode |= S_IFDIR;
244 squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);
245 squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset);
246 squashfs_i(inode)->dir_idx_cnt = 0;
247 squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode);
248
249 TRACE("Directory inode %x:%x, start_block %llx, offset %x\n",
250 SQUASHFS_INODE_BLK(ino), offset,
251 squashfs_i(inode)->start,
252 le16_to_cpu(sqsh_ino->offset));
253 break;
254 }
255 case SQUASHFS_LDIR_TYPE: {
256 struct squashfs_ldir_inode *sqsh_ino = &squashfs_ino.ldir;
257
258 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
259 sizeof(*sqsh_ino));
260 if (err < 0)
261 goto failed_read;
262
67f66cc6 263 xattr_id = le32_to_cpu(sqsh_ino->xattr);
bfe86848 264 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
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PL
265 inode->i_size = le32_to_cpu(sqsh_ino->file_size);
266 inode->i_op = &squashfs_dir_inode_ops;
267 inode->i_fop = &squashfs_dir_ops;
268 inode->i_mode |= S_IFDIR;
269 squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block);
270 squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset);
271 squashfs_i(inode)->dir_idx_start = block;
272 squashfs_i(inode)->dir_idx_offset = offset;
273 squashfs_i(inode)->dir_idx_cnt = le16_to_cpu(sqsh_ino->i_count);
274 squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode);
275
276 TRACE("Long directory inode %x:%x, start_block %llx, offset "
277 "%x\n", SQUASHFS_INODE_BLK(ino), offset,
278 squashfs_i(inode)->start,
279 le16_to_cpu(sqsh_ino->offset));
280 break;
281 }
282 case SQUASHFS_SYMLINK_TYPE:
283 case SQUASHFS_LSYMLINK_TYPE: {
284 struct squashfs_symlink_inode *sqsh_ino = &squashfs_ino.symlink;
285
286 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
287 sizeof(*sqsh_ino));
288 if (err < 0)
289 goto failed_read;
290
bfe86848 291 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
6545b246 292 inode->i_size = le32_to_cpu(sqsh_ino->symlink_size);
67f66cc6 293 inode->i_op = &squashfs_symlink_inode_ops;
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PL
294 inode->i_data.a_ops = &squashfs_symlink_aops;
295 inode->i_mode |= S_IFLNK;
296 squashfs_i(inode)->start = block;
297 squashfs_i(inode)->offset = offset;
298
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PL
299 if (type == SQUASHFS_LSYMLINK_TYPE) {
300 __le32 xattr;
301
302 err = squashfs_read_metadata(sb, NULL, &block,
303 &offset, inode->i_size);
304 if (err < 0)
305 goto failed_read;
306 err = squashfs_read_metadata(sb, &xattr, &block,
307 &offset, sizeof(xattr));
308 if (err < 0)
309 goto failed_read;
310 xattr_id = le32_to_cpu(xattr);
311 }
312
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313 TRACE("Symbolic link inode %x:%x, start_block %llx, offset "
314 "%x\n", SQUASHFS_INODE_BLK(ino), offset,
315 block, offset);
316 break;
317 }
318 case SQUASHFS_BLKDEV_TYPE:
67f66cc6 319 case SQUASHFS_CHRDEV_TYPE: {
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PL
320 struct squashfs_dev_inode *sqsh_ino = &squashfs_ino.dev;
321 unsigned int rdev;
322
323 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
324 sizeof(*sqsh_ino));
325 if (err < 0)
326 goto failed_read;
327
328 if (type == SQUASHFS_CHRDEV_TYPE)
329 inode->i_mode |= S_IFCHR;
330 else
331 inode->i_mode |= S_IFBLK;
bfe86848 332 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
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PL
333 rdev = le32_to_cpu(sqsh_ino->rdev);
334 init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));
335
336 TRACE("Device inode %x:%x, rdev %x\n",
337 SQUASHFS_INODE_BLK(ino), offset, rdev);
338 break;
339 }
67f66cc6
PL
340 case SQUASHFS_LBLKDEV_TYPE:
341 case SQUASHFS_LCHRDEV_TYPE: {
342 struct squashfs_ldev_inode *sqsh_ino = &squashfs_ino.ldev;
343 unsigned int rdev;
344
345 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
346 sizeof(*sqsh_ino));
347 if (err < 0)
348 goto failed_read;
349
350 if (type == SQUASHFS_LCHRDEV_TYPE)
351 inode->i_mode |= S_IFCHR;
352 else
353 inode->i_mode |= S_IFBLK;
354 xattr_id = le32_to_cpu(sqsh_ino->xattr);
355 inode->i_op = &squashfs_inode_ops;
bfe86848 356 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
67f66cc6
PL
357 rdev = le32_to_cpu(sqsh_ino->rdev);
358 init_special_inode(inode, inode->i_mode, new_decode_dev(rdev));
359
360 TRACE("Device inode %x:%x, rdev %x\n",
361 SQUASHFS_INODE_BLK(ino), offset, rdev);
362 break;
363 }
6545b246 364 case SQUASHFS_FIFO_TYPE:
67f66cc6 365 case SQUASHFS_SOCKET_TYPE: {
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PL
366 struct squashfs_ipc_inode *sqsh_ino = &squashfs_ino.ipc;
367
368 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
369 sizeof(*sqsh_ino));
370 if (err < 0)
371 goto failed_read;
372
373 if (type == SQUASHFS_FIFO_TYPE)
374 inode->i_mode |= S_IFIFO;
375 else
376 inode->i_mode |= S_IFSOCK;
bfe86848 377 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
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PL
378 init_special_inode(inode, inode->i_mode, 0);
379 break;
380 }
67f66cc6
PL
381 case SQUASHFS_LFIFO_TYPE:
382 case SQUASHFS_LSOCKET_TYPE: {
383 struct squashfs_lipc_inode *sqsh_ino = &squashfs_ino.lipc;
384
385 err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset,
386 sizeof(*sqsh_ino));
387 if (err < 0)
388 goto failed_read;
389
390 if (type == SQUASHFS_LFIFO_TYPE)
391 inode->i_mode |= S_IFIFO;
392 else
393 inode->i_mode |= S_IFSOCK;
394 xattr_id = le32_to_cpu(sqsh_ino->xattr);
395 inode->i_op = &squashfs_inode_ops;
bfe86848 396 set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
67f66cc6
PL
397 init_special_inode(inode, inode->i_mode, 0);
398 break;
399 }
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400 default:
401 ERROR("Unknown inode type %d in squashfs_iget!\n", type);
402 return -EINVAL;
403 }
404
67f66cc6
PL
405 if (xattr_id != SQUASHFS_INVALID_XATTR && msblk->xattr_id_table) {
406 err = squashfs_xattr_lookup(sb, xattr_id,
407 &squashfs_i(inode)->xattr_count,
408 &squashfs_i(inode)->xattr_size,
409 &squashfs_i(inode)->xattr);
410 if (err < 0)
411 goto failed_read;
412 inode->i_blocks += ((squashfs_i(inode)->xattr_size - 1) >> 9)
413 + 1;
414 } else
415 squashfs_i(inode)->xattr_count = 0;
416
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PL
417 return 0;
418
419failed_read:
420 ERROR("Unable to read inode 0x%llx\n", ino);
421 return err;
422}
67f66cc6
PL
423
424
425const struct inode_operations squashfs_inode_ops = {
426 .getxattr = generic_getxattr,
427 .listxattr = squashfs_listxattr
428};
429