1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Squashfs - a compressed read only filesystem for Linux |
4 | * |
5 | * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 |
6 | * Phillip Lougher <phillip@squashfs.org.uk> |
7 | * |
8 | * super.c |
9 | */ |
10 | |
11 | /* |
12 | * This file implements code to read the superblock, read and initialise |
13 | * in-memory structures at mount time, and all the VFS glue code to register |
14 | * the filesystem. |
15 | */ |
16 | |
17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
18 | |
19 | #include <linux/blkdev.h> |
20 | #include <linux/fs.h> |
21 | #include <linux/fs_context.h> |
22 | #include <linux/fs_parser.h> |
23 | #include <linux/vfs.h> |
24 | #include <linux/slab.h> |
25 | #include <linux/mutex.h> |
26 | #include <linux/seq_file.h> |
27 | #include <linux/pagemap.h> |
28 | #include <linux/init.h> |
29 | #include <linux/module.h> |
30 | #include <linux/magic.h> |
31 | #include <linux/xattr.h> |
32 | |
33 | #include "squashfs_fs.h" |
34 | #include "squashfs_fs_sb.h" |
35 | #include "squashfs_fs_i.h" |
36 | #include "squashfs.h" |
37 | #include "decompressor.h" |
38 | #include "xattr.h" |
39 | |
40 | static struct file_system_type squashfs_fs_type; |
41 | static const struct super_operations squashfs_super_ops; |
42 | |
43 | enum Opt_errors { |
44 | Opt_errors_continue, |
45 | Opt_errors_panic, |
46 | }; |
47 | |
48 | enum squashfs_param { |
49 | Opt_errors, |
50 | Opt_threads, |
51 | }; |
52 | |
53 | struct squashfs_mount_opts { |
54 | enum Opt_errors errors; |
55 | const struct squashfs_decompressor_thread_ops *thread_ops; |
56 | int thread_num; |
57 | }; |
58 | |
59 | static const struct constant_table squashfs_param_errors[] = { |
60 | {"continue" , Opt_errors_continue }, |
61 | {"panic" , Opt_errors_panic }, |
62 | {} |
63 | }; |
64 | |
65 | static const struct fs_parameter_spec squashfs_fs_parameters[] = { |
66 | fsparam_enum("errors" , Opt_errors, squashfs_param_errors), |
67 | fsparam_string("threads" , Opt_threads), |
68 | {} |
69 | }; |
70 | |
71 | |
72 | static int squashfs_parse_param_threads_str(const char *str, struct squashfs_mount_opts *opts) |
73 | { |
74 | #ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT |
75 | if (strcmp(str, "single" ) == 0) { |
76 | opts->thread_ops = &squashfs_decompressor_single; |
77 | return 0; |
78 | } |
79 | if (strcmp(str, "multi" ) == 0) { |
80 | opts->thread_ops = &squashfs_decompressor_multi; |
81 | return 0; |
82 | } |
83 | if (strcmp(str, "percpu" ) == 0) { |
84 | opts->thread_ops = &squashfs_decompressor_percpu; |
85 | return 0; |
86 | } |
87 | #endif |
88 | return -EINVAL; |
89 | } |
90 | |
91 | static int squashfs_parse_param_threads_num(const char *str, struct squashfs_mount_opts *opts) |
92 | { |
93 | #ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS |
94 | int ret; |
95 | unsigned long num; |
96 | |
97 | ret = kstrtoul(s: str, base: 0, res: &num); |
98 | if (ret != 0) |
99 | return -EINVAL; |
100 | if (num > 1) { |
101 | opts->thread_ops = &squashfs_decompressor_multi; |
102 | if (num > opts->thread_ops->max_decompressors()) |
103 | return -EINVAL; |
104 | opts->thread_num = (int)num; |
105 | return 0; |
106 | } |
107 | #ifdef CONFIG_SQUASHFS_DECOMP_SINGLE |
108 | if (num == 1) { |
109 | opts->thread_ops = &squashfs_decompressor_single; |
110 | opts->thread_num = 1; |
111 | return 0; |
112 | } |
113 | #endif |
114 | #endif /* !CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS */ |
115 | return -EINVAL; |
116 | } |
117 | |
118 | static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_opts *opts) |
119 | { |
120 | int ret = squashfs_parse_param_threads_str(str, opts); |
121 | |
122 | if (ret == 0) |
123 | return ret; |
124 | return squashfs_parse_param_threads_num(str, opts); |
125 | } |
126 | |
127 | static int squashfs_parse_param(struct fs_context *fc, struct fs_parameter *param) |
128 | { |
129 | struct squashfs_mount_opts *opts = fc->fs_private; |
130 | struct fs_parse_result result; |
131 | int opt; |
132 | |
133 | opt = fs_parse(fc, desc: squashfs_fs_parameters, param, result: &result); |
134 | if (opt < 0) |
135 | return opt; |
136 | |
137 | switch (opt) { |
138 | case Opt_errors: |
139 | opts->errors = result.uint_32; |
140 | break; |
141 | case Opt_threads: |
142 | if (squashfs_parse_param_threads(str: param->string, opts) != 0) |
143 | return -EINVAL; |
144 | break; |
145 | default: |
146 | return -EINVAL; |
147 | } |
148 | |
149 | return 0; |
150 | } |
151 | |
152 | static const struct squashfs_decompressor *supported_squashfs_filesystem( |
153 | struct fs_context *fc, |
154 | short major, short minor, short id) |
155 | { |
156 | const struct squashfs_decompressor *decompressor; |
157 | |
158 | if (major < SQUASHFS_MAJOR) { |
159 | errorf(fc, "Major/Minor mismatch, older Squashfs %d.%d " |
160 | "filesystems are unsupported" , major, minor); |
161 | return NULL; |
162 | } else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) { |
163 | errorf(fc, "Major/Minor mismatch, trying to mount newer " |
164 | "%d.%d filesystem" , major, minor); |
165 | errorf(fc, "Please update your kernel" ); |
166 | return NULL; |
167 | } |
168 | |
169 | decompressor = squashfs_lookup_decompressor(id); |
170 | if (!decompressor->supported) { |
171 | errorf(fc, "Filesystem uses \"%s\" compression. This is not supported" , |
172 | decompressor->name); |
173 | return NULL; |
174 | } |
175 | |
176 | return decompressor; |
177 | } |
178 | |
179 | |
180 | static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc) |
181 | { |
182 | struct squashfs_mount_opts *opts = fc->fs_private; |
183 | struct squashfs_sb_info *msblk; |
184 | struct squashfs_super_block *sblk = NULL; |
185 | struct inode *root; |
186 | long long root_inode; |
187 | unsigned short flags; |
188 | unsigned int fragments; |
189 | u64 lookup_table_start, xattr_id_table_start, next_table; |
190 | int err; |
191 | |
192 | TRACE("Entered squashfs_fill_superblock\n" ); |
193 | |
194 | sb->s_fs_info = kzalloc(size: sizeof(*msblk), GFP_KERNEL); |
195 | if (sb->s_fs_info == NULL) { |
196 | ERROR("Failed to allocate squashfs_sb_info\n" ); |
197 | return -ENOMEM; |
198 | } |
199 | msblk = sb->s_fs_info; |
200 | msblk->thread_ops = opts->thread_ops; |
201 | |
202 | msblk->panic_on_errors = (opts->errors == Opt_errors_panic); |
203 | |
204 | msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE); |
205 | msblk->devblksize_log2 = ffz(~msblk->devblksize); |
206 | |
207 | mutex_init(&msblk->meta_index_mutex); |
208 | |
209 | /* |
210 | * msblk->bytes_used is checked in squashfs_read_table to ensure reads |
211 | * are not beyond filesystem end. But as we're using |
212 | * squashfs_read_table here to read the superblock (including the value |
213 | * of bytes_used) we need to set it to an initial sensible dummy value |
214 | */ |
215 | msblk->bytes_used = sizeof(*sblk); |
216 | sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk)); |
217 | |
218 | if (IS_ERR(ptr: sblk)) { |
219 | errorf(fc, "unable to read squashfs_super_block" ); |
220 | err = PTR_ERR(ptr: sblk); |
221 | sblk = NULL; |
222 | goto failed_mount; |
223 | } |
224 | |
225 | err = -EINVAL; |
226 | |
227 | /* Check it is a SQUASHFS superblock */ |
228 | sb->s_magic = le32_to_cpu(sblk->s_magic); |
229 | if (sb->s_magic != SQUASHFS_MAGIC) { |
230 | if (!(fc->sb_flags & SB_SILENT)) |
231 | errorf(fc, "Can't find a SQUASHFS superblock on %pg" , |
232 | sb->s_bdev); |
233 | goto failed_mount; |
234 | } |
235 | |
236 | if (opts->thread_num == 0) { |
237 | msblk->max_thread_num = msblk->thread_ops->max_decompressors(); |
238 | } else { |
239 | msblk->max_thread_num = opts->thread_num; |
240 | } |
241 | |
242 | /* Check the MAJOR & MINOR versions and lookup compression type */ |
243 | msblk->decompressor = supported_squashfs_filesystem( |
244 | fc, |
245 | le16_to_cpu(sblk->s_major), |
246 | le16_to_cpu(sblk->s_minor), |
247 | le16_to_cpu(sblk->compression)); |
248 | if (msblk->decompressor == NULL) |
249 | goto failed_mount; |
250 | |
251 | /* Check the filesystem does not extend beyond the end of the |
252 | block device */ |
253 | msblk->bytes_used = le64_to_cpu(sblk->bytes_used); |
254 | if (msblk->bytes_used < 0 || |
255 | msblk->bytes_used > bdev_nr_bytes(bdev: sb->s_bdev)) |
256 | goto failed_mount; |
257 | |
258 | /* Check block size for sanity */ |
259 | msblk->block_size = le32_to_cpu(sblk->block_size); |
260 | if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE) |
261 | goto insanity; |
262 | |
263 | /* |
264 | * Check the system page size is not larger than the filesystem |
265 | * block size (by default 128K). This is currently not supported. |
266 | */ |
267 | if (PAGE_SIZE > msblk->block_size) { |
268 | errorf(fc, "Page size > filesystem block size (%d). This is " |
269 | "currently not supported!" , msblk->block_size); |
270 | goto failed_mount; |
271 | } |
272 | |
273 | /* Check block log for sanity */ |
274 | msblk->block_log = le16_to_cpu(sblk->block_log); |
275 | if (msblk->block_log > SQUASHFS_FILE_MAX_LOG) |
276 | goto failed_mount; |
277 | |
278 | /* Check that block_size and block_log match */ |
279 | if (msblk->block_size != (1 << msblk->block_log)) |
280 | goto insanity; |
281 | |
282 | /* Check the root inode for sanity */ |
283 | root_inode = le64_to_cpu(sblk->root_inode); |
284 | if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE) |
285 | goto insanity; |
286 | |
287 | msblk->inode_table = le64_to_cpu(sblk->inode_table_start); |
288 | msblk->directory_table = le64_to_cpu(sblk->directory_table_start); |
289 | msblk->inodes = le32_to_cpu(sblk->inodes); |
290 | msblk->fragments = le32_to_cpu(sblk->fragments); |
291 | msblk->ids = le16_to_cpu(sblk->no_ids); |
292 | flags = le16_to_cpu(sblk->flags); |
293 | |
294 | TRACE("Found valid superblock on %pg\n" , sb->s_bdev); |
295 | TRACE("Inodes are %scompressed\n" , SQUASHFS_UNCOMPRESSED_INODES(flags) |
296 | ? "un" : "" ); |
297 | TRACE("Data is %scompressed\n" , SQUASHFS_UNCOMPRESSED_DATA(flags) |
298 | ? "un" : "" ); |
299 | TRACE("Filesystem size %lld bytes\n" , msblk->bytes_used); |
300 | TRACE("Block size %d\n" , msblk->block_size); |
301 | TRACE("Number of inodes %d\n" , msblk->inodes); |
302 | TRACE("Number of fragments %d\n" , msblk->fragments); |
303 | TRACE("Number of ids %d\n" , msblk->ids); |
304 | TRACE("sblk->inode_table_start %llx\n" , msblk->inode_table); |
305 | TRACE("sblk->directory_table_start %llx\n" , msblk->directory_table); |
306 | TRACE("sblk->fragment_table_start %llx\n" , |
307 | (u64) le64_to_cpu(sblk->fragment_table_start)); |
308 | TRACE("sblk->id_table_start %llx\n" , |
309 | (u64) le64_to_cpu(sblk->id_table_start)); |
310 | |
311 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
312 | sb->s_time_min = 0; |
313 | sb->s_time_max = U32_MAX; |
314 | sb->s_flags |= SB_RDONLY; |
315 | sb->s_op = &squashfs_super_ops; |
316 | |
317 | err = -ENOMEM; |
318 | |
319 | msblk->block_cache = squashfs_cache_init("metadata" , |
320 | SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE); |
321 | if (msblk->block_cache == NULL) |
322 | goto failed_mount; |
323 | |
324 | /* Allocate read_page block */ |
325 | msblk->read_page = squashfs_cache_init("data" , |
326 | msblk->max_thread_num, msblk->block_size); |
327 | if (msblk->read_page == NULL) { |
328 | errorf(fc, "Failed to allocate read_page block" ); |
329 | goto failed_mount; |
330 | } |
331 | |
332 | if (msblk->devblksize == PAGE_SIZE) { |
333 | struct inode *cache = new_inode(sb); |
334 | |
335 | if (cache == NULL) |
336 | goto failed_mount; |
337 | |
338 | set_nlink(inode: cache, nlink: 1); |
339 | cache->i_size = OFFSET_MAX; |
340 | mapping_set_gfp_mask(m: cache->i_mapping, GFP_NOFS); |
341 | |
342 | msblk->cache_mapping = cache->i_mapping; |
343 | } |
344 | |
345 | msblk->stream = squashfs_decompressor_setup(sb, flags); |
346 | if (IS_ERR(ptr: msblk->stream)) { |
347 | err = PTR_ERR(ptr: msblk->stream); |
348 | msblk->stream = NULL; |
349 | goto insanity; |
350 | } |
351 | |
352 | /* Handle xattrs */ |
353 | sb->s_xattr = squashfs_xattr_handlers; |
354 | xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start); |
355 | if (xattr_id_table_start == SQUASHFS_INVALID_BLK) { |
356 | next_table = msblk->bytes_used; |
357 | goto allocate_id_index_table; |
358 | } |
359 | |
360 | /* Allocate and read xattr id lookup table */ |
361 | msblk->xattr_id_table = squashfs_read_xattr_id_table(sb, |
362 | xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids); |
363 | if (IS_ERR(ptr: msblk->xattr_id_table)) { |
364 | errorf(fc, "unable to read xattr id index table" ); |
365 | err = PTR_ERR(ptr: msblk->xattr_id_table); |
366 | msblk->xattr_id_table = NULL; |
367 | if (err != -ENOTSUPP) |
368 | goto failed_mount; |
369 | } |
370 | next_table = msblk->xattr_table; |
371 | |
372 | allocate_id_index_table: |
373 | /* Allocate and read id index table */ |
374 | msblk->id_table = squashfs_read_id_index_table(sb, |
375 | le64_to_cpu(sblk->id_table_start), next_table, msblk->ids); |
376 | if (IS_ERR(ptr: msblk->id_table)) { |
377 | errorf(fc, "unable to read id index table" ); |
378 | err = PTR_ERR(ptr: msblk->id_table); |
379 | msblk->id_table = NULL; |
380 | goto failed_mount; |
381 | } |
382 | next_table = le64_to_cpu(msblk->id_table[0]); |
383 | |
384 | /* Handle inode lookup table */ |
385 | lookup_table_start = le64_to_cpu(sblk->lookup_table_start); |
386 | if (lookup_table_start == SQUASHFS_INVALID_BLK) |
387 | goto handle_fragments; |
388 | |
389 | /* Allocate and read inode lookup table */ |
390 | msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb, |
391 | lookup_table_start, next_table, msblk->inodes); |
392 | if (IS_ERR(ptr: msblk->inode_lookup_table)) { |
393 | errorf(fc, "unable to read inode lookup table" ); |
394 | err = PTR_ERR(ptr: msblk->inode_lookup_table); |
395 | msblk->inode_lookup_table = NULL; |
396 | goto failed_mount; |
397 | } |
398 | next_table = le64_to_cpu(msblk->inode_lookup_table[0]); |
399 | |
400 | sb->s_export_op = &squashfs_export_ops; |
401 | |
402 | handle_fragments: |
403 | fragments = msblk->fragments; |
404 | if (fragments == 0) |
405 | goto check_directory_table; |
406 | |
407 | msblk->fragment_cache = squashfs_cache_init("fragment" , |
408 | SQUASHFS_CACHED_FRAGMENTS, msblk->block_size); |
409 | if (msblk->fragment_cache == NULL) { |
410 | err = -ENOMEM; |
411 | goto failed_mount; |
412 | } |
413 | |
414 | /* Allocate and read fragment index table */ |
415 | msblk->fragment_index = squashfs_read_fragment_index_table(sb, |
416 | le64_to_cpu(sblk->fragment_table_start), next_table, fragments); |
417 | if (IS_ERR(ptr: msblk->fragment_index)) { |
418 | errorf(fc, "unable to read fragment index table" ); |
419 | err = PTR_ERR(ptr: msblk->fragment_index); |
420 | msblk->fragment_index = NULL; |
421 | goto failed_mount; |
422 | } |
423 | next_table = le64_to_cpu(msblk->fragment_index[0]); |
424 | |
425 | check_directory_table: |
426 | /* Sanity check directory_table */ |
427 | if (msblk->directory_table > next_table) { |
428 | err = -EINVAL; |
429 | goto insanity; |
430 | } |
431 | |
432 | /* Sanity check inode_table */ |
433 | if (msblk->inode_table >= msblk->directory_table) { |
434 | err = -EINVAL; |
435 | goto insanity; |
436 | } |
437 | |
438 | /* allocate root */ |
439 | root = new_inode(sb); |
440 | if (!root) { |
441 | err = -ENOMEM; |
442 | goto failed_mount; |
443 | } |
444 | |
445 | err = squashfs_read_inode(root, root_inode); |
446 | if (err) { |
447 | make_bad_inode(root); |
448 | iput(root); |
449 | goto failed_mount; |
450 | } |
451 | insert_inode_hash(inode: root); |
452 | |
453 | sb->s_root = d_make_root(root); |
454 | if (sb->s_root == NULL) { |
455 | ERROR("Root inode create failed\n" ); |
456 | err = -ENOMEM; |
457 | goto failed_mount; |
458 | } |
459 | |
460 | TRACE("Leaving squashfs_fill_super\n" ); |
461 | kfree(objp: sblk); |
462 | return 0; |
463 | |
464 | insanity: |
465 | errorf(fc, "squashfs image failed sanity check" ); |
466 | failed_mount: |
467 | squashfs_cache_delete(msblk->block_cache); |
468 | squashfs_cache_delete(msblk->fragment_cache); |
469 | squashfs_cache_delete(msblk->read_page); |
470 | if (msblk->cache_mapping) |
471 | iput(msblk->cache_mapping->host); |
472 | msblk->thread_ops->destroy(msblk); |
473 | kfree(objp: msblk->inode_lookup_table); |
474 | kfree(objp: msblk->fragment_index); |
475 | kfree(objp: msblk->id_table); |
476 | kfree(objp: msblk->xattr_id_table); |
477 | kfree(objp: sb->s_fs_info); |
478 | sb->s_fs_info = NULL; |
479 | kfree(objp: sblk); |
480 | return err; |
481 | } |
482 | |
483 | static int squashfs_get_tree(struct fs_context *fc) |
484 | { |
485 | return get_tree_bdev(fc, fill_super: squashfs_fill_super); |
486 | } |
487 | |
488 | static int squashfs_reconfigure(struct fs_context *fc) |
489 | { |
490 | struct super_block *sb = fc->root->d_sb; |
491 | struct squashfs_sb_info *msblk = sb->s_fs_info; |
492 | struct squashfs_mount_opts *opts = fc->fs_private; |
493 | |
494 | sync_filesystem(fc->root->d_sb); |
495 | fc->sb_flags |= SB_RDONLY; |
496 | |
497 | msblk->panic_on_errors = (opts->errors == Opt_errors_panic); |
498 | |
499 | return 0; |
500 | } |
501 | |
502 | static void squashfs_free_fs_context(struct fs_context *fc) |
503 | { |
504 | kfree(objp: fc->fs_private); |
505 | } |
506 | |
507 | static const struct fs_context_operations squashfs_context_ops = { |
508 | .get_tree = squashfs_get_tree, |
509 | .free = squashfs_free_fs_context, |
510 | .parse_param = squashfs_parse_param, |
511 | .reconfigure = squashfs_reconfigure, |
512 | }; |
513 | |
514 | static int squashfs_show_options(struct seq_file *s, struct dentry *root) |
515 | { |
516 | struct super_block *sb = root->d_sb; |
517 | struct squashfs_sb_info *msblk = sb->s_fs_info; |
518 | |
519 | if (msblk->panic_on_errors) |
520 | seq_puts(m: s, s: ",errors=panic" ); |
521 | else |
522 | seq_puts(m: s, s: ",errors=continue" ); |
523 | |
524 | #ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT |
525 | if (msblk->thread_ops == &squashfs_decompressor_single) { |
526 | seq_puts(m: s, s: ",threads=single" ); |
527 | return 0; |
528 | } |
529 | if (msblk->thread_ops == &squashfs_decompressor_percpu) { |
530 | seq_puts(m: s, s: ",threads=percpu" ); |
531 | return 0; |
532 | } |
533 | #endif |
534 | #ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS |
535 | seq_printf(m: s, fmt: ",threads=%d" , msblk->max_thread_num); |
536 | #endif |
537 | return 0; |
538 | } |
539 | |
540 | static int squashfs_init_fs_context(struct fs_context *fc) |
541 | { |
542 | struct squashfs_mount_opts *opts; |
543 | |
544 | opts = kzalloc(size: sizeof(*opts), GFP_KERNEL); |
545 | if (!opts) |
546 | return -ENOMEM; |
547 | |
548 | #ifdef CONFIG_SQUASHFS_DECOMP_SINGLE |
549 | opts->thread_ops = &squashfs_decompressor_single; |
550 | #elif defined(CONFIG_SQUASHFS_DECOMP_MULTI) |
551 | opts->thread_ops = &squashfs_decompressor_multi; |
552 | #elif defined(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU) |
553 | opts->thread_ops = &squashfs_decompressor_percpu; |
554 | #else |
555 | #error "fail: unknown squashfs decompression thread mode?" |
556 | #endif |
557 | opts->thread_num = 0; |
558 | fc->fs_private = opts; |
559 | fc->ops = &squashfs_context_ops; |
560 | return 0; |
561 | } |
562 | |
563 | static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
564 | { |
565 | struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info; |
566 | u64 id = huge_encode_dev(dev: dentry->d_sb->s_bdev->bd_dev); |
567 | |
568 | TRACE("Entered squashfs_statfs\n" ); |
569 | |
570 | buf->f_type = SQUASHFS_MAGIC; |
571 | buf->f_bsize = msblk->block_size; |
572 | buf->f_blocks = ((msblk->bytes_used - 1) >> msblk->block_log) + 1; |
573 | buf->f_bfree = buf->f_bavail = 0; |
574 | buf->f_files = msblk->inodes; |
575 | buf->f_ffree = 0; |
576 | buf->f_namelen = SQUASHFS_NAME_LEN; |
577 | buf->f_fsid = u64_to_fsid(v: id); |
578 | |
579 | return 0; |
580 | } |
581 | |
582 | |
583 | static void squashfs_put_super(struct super_block *sb) |
584 | { |
585 | if (sb->s_fs_info) { |
586 | struct squashfs_sb_info *sbi = sb->s_fs_info; |
587 | squashfs_cache_delete(sbi->block_cache); |
588 | squashfs_cache_delete(sbi->fragment_cache); |
589 | squashfs_cache_delete(sbi->read_page); |
590 | if (sbi->cache_mapping) |
591 | iput(sbi->cache_mapping->host); |
592 | sbi->thread_ops->destroy(sbi); |
593 | kfree(objp: sbi->id_table); |
594 | kfree(objp: sbi->fragment_index); |
595 | kfree(objp: sbi->meta_index); |
596 | kfree(objp: sbi->inode_lookup_table); |
597 | kfree(objp: sbi->xattr_id_table); |
598 | kfree(objp: sb->s_fs_info); |
599 | sb->s_fs_info = NULL; |
600 | } |
601 | } |
602 | |
603 | static struct kmem_cache *squashfs_inode_cachep; |
604 | |
605 | |
606 | static void init_once(void *foo) |
607 | { |
608 | struct squashfs_inode_info *ei = foo; |
609 | |
610 | inode_init_once(&ei->vfs_inode); |
611 | } |
612 | |
613 | |
614 | static int __init init_inodecache(void) |
615 | { |
616 | squashfs_inode_cachep = kmem_cache_create(name: "squashfs_inode_cache" , |
617 | size: sizeof(struct squashfs_inode_info), align: 0, |
618 | SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT, |
619 | ctor: init_once); |
620 | |
621 | return squashfs_inode_cachep ? 0 : -ENOMEM; |
622 | } |
623 | |
624 | |
625 | static void destroy_inodecache(void) |
626 | { |
627 | /* |
628 | * Make sure all delayed rcu free inodes are flushed before we |
629 | * destroy cache. |
630 | */ |
631 | rcu_barrier(); |
632 | kmem_cache_destroy(s: squashfs_inode_cachep); |
633 | } |
634 | |
635 | |
636 | static int __init init_squashfs_fs(void) |
637 | { |
638 | int err = init_inodecache(); |
639 | |
640 | if (err) |
641 | return err; |
642 | |
643 | err = register_filesystem(&squashfs_fs_type); |
644 | if (err) { |
645 | destroy_inodecache(); |
646 | return err; |
647 | } |
648 | |
649 | pr_info("version 4.0 (2009/01/31) Phillip Lougher\n" ); |
650 | |
651 | return 0; |
652 | } |
653 | |
654 | |
655 | static void __exit exit_squashfs_fs(void) |
656 | { |
657 | unregister_filesystem(&squashfs_fs_type); |
658 | destroy_inodecache(); |
659 | } |
660 | |
661 | |
662 | static struct inode *squashfs_alloc_inode(struct super_block *sb) |
663 | { |
664 | struct squashfs_inode_info *ei = |
665 | alloc_inode_sb(sb, cache: squashfs_inode_cachep, GFP_KERNEL); |
666 | |
667 | return ei ? &ei->vfs_inode : NULL; |
668 | } |
669 | |
670 | |
671 | static void squashfs_free_inode(struct inode *inode) |
672 | { |
673 | kmem_cache_free(s: squashfs_inode_cachep, objp: squashfs_i(inode)); |
674 | } |
675 | |
676 | static struct file_system_type squashfs_fs_type = { |
677 | .owner = THIS_MODULE, |
678 | .name = "squashfs" , |
679 | .init_fs_context = squashfs_init_fs_context, |
680 | .parameters = squashfs_fs_parameters, |
681 | .kill_sb = kill_block_super, |
682 | .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, |
683 | }; |
684 | MODULE_ALIAS_FS("squashfs" ); |
685 | |
686 | static const struct super_operations squashfs_super_ops = { |
687 | .alloc_inode = squashfs_alloc_inode, |
688 | .free_inode = squashfs_free_inode, |
689 | .statfs = squashfs_statfs, |
690 | .put_super = squashfs_put_super, |
691 | .show_options = squashfs_show_options, |
692 | }; |
693 | |
694 | module_init(init_squashfs_fs); |
695 | module_exit(exit_squashfs_fs); |
696 | MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem" ); |
697 | MODULE_AUTHOR("Phillip Lougher <phillip@squashfs.org.uk>" ); |
698 | MODULE_LICENSE("GPL" ); |
699 | |