blob: 5e79bfa4f260784dcba925e4d6611585542d88c6 [file] [log] [blame]
Phillip Lougher0aa66612009-01-05 08:46:25 +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 Lougher0aa66612009-01-05 08:46:25 +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 * super.c
22 */
23
24/*
25 * This file implements code to read the superblock, read and initialise
26 * in-memory structures at mount time, and all the VFS glue code to register
27 * the filesystem.
28 */
29
Fabian Frederickc811f5f2014-08-06 16:03:52 -070030#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31
Phillip Lougher0aa66612009-01-05 08:46:25 +000032#include <linux/fs.h>
33#include <linux/vfs.h>
34#include <linux/slab.h>
35#include <linux/mutex.h>
36#include <linux/pagemap.h>
37#include <linux/init.h>
38#include <linux/module.h>
Qinghuang Feng1bcbf312009-01-15 13:51:03 -080039#include <linux/magic.h>
Phillip Lougher4b5397d2010-05-14 20:48:47 +010040#include <linux/xattr.h>
Phillip Lougher0aa66612009-01-05 08:46:25 +000041
42#include "squashfs_fs.h"
43#include "squashfs_fs_sb.h"
44#include "squashfs_fs_i.h"
45#include "squashfs.h"
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010046#include "decompressor.h"
Phillip Lougher01e5b4e2010-05-17 19:39:02 +010047#include "xattr.h"
Phillip Lougher0aa66612009-01-05 08:46:25 +000048
49static struct file_system_type squashfs_fs_type;
Alexey Dobriyanb87221d2009-09-21 17:01:09 -070050static const struct super_operations squashfs_super_ops;
Phillip Lougher0aa66612009-01-05 08:46:25 +000051
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010052static const struct squashfs_decompressor *supported_squashfs_filesystem(short
53 major, short minor, short id)
Phillip Lougher0aa66612009-01-05 08:46:25 +000054{
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010055 const struct squashfs_decompressor *decompressor;
56
Phillip Lougher0aa66612009-01-05 08:46:25 +000057 if (major < SQUASHFS_MAJOR) {
58 ERROR("Major/Minor mismatch, older Squashfs %d.%d "
59 "filesystems are unsupported\n", major, minor);
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010060 return NULL;
Phillip Lougher0aa66612009-01-05 08:46:25 +000061 } else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) {
62 ERROR("Major/Minor mismatch, trying to mount newer "
63 "%d.%d filesystem\n", major, minor);
64 ERROR("Please update your kernel\n");
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010065 return NULL;
Phillip Lougher0aa66612009-01-05 08:46:25 +000066 }
67
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010068 decompressor = squashfs_lookup_decompressor(id);
69 if (!decompressor->supported) {
70 ERROR("Filesystem uses \"%s\" compression. This is not "
71 "supported\n", decompressor->name);
72 return NULL;
73 }
Phillip Lougher0aa66612009-01-05 08:46:25 +000074
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010075 return decompressor;
Phillip Lougher0aa66612009-01-05 08:46:25 +000076}
77
78
79static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
80{
81 struct squashfs_sb_info *msblk;
82 struct squashfs_super_block *sblk = NULL;
Phillip Lougher0aa66612009-01-05 08:46:25 +000083 struct inode *root;
84 long long root_inode;
85 unsigned short flags;
86 unsigned int fragments;
Phillip Lougher37986f62011-05-24 04:05:22 +010087 u64 lookup_table_start, xattr_id_table_start, next_table;
Phillip Lougher0aa66612009-01-05 08:46:25 +000088 int err;
89
90 TRACE("Entered squashfs_fill_superblock\n");
91
92 sb->s_fs_info = kzalloc(sizeof(*msblk), GFP_KERNEL);
93 if (sb->s_fs_info == NULL) {
94 ERROR("Failed to allocate squashfs_sb_info\n");
95 return -ENOMEM;
96 }
97 msblk = sb->s_fs_info;
98
Phillip Lougher7657cac2011-10-22 01:34:48 +010099 msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000100 msblk->devblksize_log2 = ffz(~msblk->devblksize);
101
Phillip Lougher0aa66612009-01-05 08:46:25 +0000102 mutex_init(&msblk->meta_index_mutex);
103
104 /*
105 * msblk->bytes_used is checked in squashfs_read_table to ensure reads
106 * are not beyond filesystem end. But as we're using
107 * squashfs_read_table here to read the superblock (including the value
108 * of bytes_used) we need to set it to an initial sensible dummy value
109 */
110 msblk->bytes_used = sizeof(*sblk);
Phillip Lougher82de6472011-05-20 02:26:43 +0100111 sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk));
Phillip Lougher0aa66612009-01-05 08:46:25 +0000112
Phillip Lougher82de6472011-05-20 02:26:43 +0100113 if (IS_ERR(sblk)) {
Phillip Lougher0aa66612009-01-05 08:46:25 +0000114 ERROR("unable to read squashfs_super_block\n");
Phillip Lougher82de6472011-05-20 02:26:43 +0100115 err = PTR_ERR(sblk);
116 sblk = NULL;
Phillip Lougher0aa66612009-01-05 08:46:25 +0000117 goto failed_mount;
118 }
119
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +0100120 err = -EINVAL;
121
Phillip Lougher0aa66612009-01-05 08:46:25 +0000122 /* Check it is a SQUASHFS superblock */
123 sb->s_magic = le32_to_cpu(sblk->s_magic);
124 if (sb->s_magic != SQUASHFS_MAGIC) {
125 if (!silent)
Dmitry Monakhova1c6f0572015-04-13 16:31:37 +0400126 ERROR("Can't find a SQUASHFS superblock on %pg\n",
127 sb->s_bdev);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000128 goto failed_mount;
129 }
130
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +0100131 /* Check the MAJOR & MINOR versions and lookup compression type */
132 msblk->decompressor = supported_squashfs_filesystem(
133 le16_to_cpu(sblk->s_major),
Phillip Lougher0aa66612009-01-05 08:46:25 +0000134 le16_to_cpu(sblk->s_minor),
135 le16_to_cpu(sblk->compression));
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +0100136 if (msblk->decompressor == NULL)
Phillip Lougher0aa66612009-01-05 08:46:25 +0000137 goto failed_mount;
138
Phillip Lougher0aa66612009-01-05 08:46:25 +0000139 /* Check the filesystem does not extend beyond the end of the
140 block device */
141 msblk->bytes_used = le64_to_cpu(sblk->bytes_used);
142 if (msblk->bytes_used < 0 || msblk->bytes_used >
143 i_size_read(sb->s_bdev->bd_inode))
144 goto failed_mount;
145
146 /* Check block size for sanity */
147 msblk->block_size = le32_to_cpu(sblk->block_size);
148 if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
149 goto failed_mount;
150
Phillip Lougherfffb47b2009-05-13 02:59:26 +0100151 /*
152 * Check the system page size is not larger than the filesystem
153 * block size (by default 128K). This is currently not supported.
154 */
155 if (PAGE_CACHE_SIZE > msblk->block_size) {
156 ERROR("Page size > filesystem block size (%d). This is "
157 "currently not supported!\n", msblk->block_size);
158 goto failed_mount;
159 }
160
Phillip Lougher4b0180a2012-03-09 03:02:59 +0000161 /* Check block log for sanity */
Phillip Lougher0aa66612009-01-05 08:46:25 +0000162 msblk->block_log = le16_to_cpu(sblk->block_log);
163 if (msblk->block_log > SQUASHFS_FILE_MAX_LOG)
164 goto failed_mount;
165
Phillip Lougher4b0180a2012-03-09 03:02:59 +0000166 /* Check that block_size and block_log match */
167 if (msblk->block_size != (1 << msblk->block_log))
168 goto failed_mount;
169
Phillip Lougher0aa66612009-01-05 08:46:25 +0000170 /* Check the root inode for sanity */
171 root_inode = le64_to_cpu(sblk->root_inode);
172 if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE)
173 goto failed_mount;
174
175 msblk->inode_table = le64_to_cpu(sblk->inode_table_start);
176 msblk->directory_table = le64_to_cpu(sblk->directory_table_start);
177 msblk->inodes = le32_to_cpu(sblk->inodes);
178 flags = le16_to_cpu(sblk->flags);
179
Dmitry Monakhova1c6f0572015-04-13 16:31:37 +0400180 TRACE("Found valid superblock on %pg\n", sb->s_bdev);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000181 TRACE("Inodes are %scompressed\n", SQUASHFS_UNCOMPRESSED_INODES(flags)
182 ? "un" : "");
183 TRACE("Data is %scompressed\n", SQUASHFS_UNCOMPRESSED_DATA(flags)
184 ? "un" : "");
185 TRACE("Filesystem size %lld bytes\n", msblk->bytes_used);
186 TRACE("Block size %d\n", msblk->block_size);
187 TRACE("Number of inodes %d\n", msblk->inodes);
188 TRACE("Number of fragments %d\n", le32_to_cpu(sblk->fragments));
189 TRACE("Number of ids %d\n", le16_to_cpu(sblk->no_ids));
190 TRACE("sblk->inode_table_start %llx\n", msblk->inode_table);
191 TRACE("sblk->directory_table_start %llx\n", msblk->directory_table);
192 TRACE("sblk->fragment_table_start %llx\n",
193 (u64) le64_to_cpu(sblk->fragment_table_start));
194 TRACE("sblk->id_table_start %llx\n",
195 (u64) le64_to_cpu(sblk->id_table_start));
196
197 sb->s_maxbytes = MAX_LFS_FILESIZE;
198 sb->s_flags |= MS_RDONLY;
199 sb->s_op = &squashfs_super_ops;
200
201 err = -ENOMEM;
202
203 msblk->block_cache = squashfs_cache_init("metadata",
204 SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
205 if (msblk->block_cache == NULL)
206 goto failed_mount;
207
208 /* Allocate read_page block */
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000209 msblk->read_page = squashfs_cache_init("data",
210 squashfs_max_decompressors(), msblk->block_size);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000211 if (msblk->read_page == NULL) {
212 ERROR("Failed to allocate read_page block\n");
213 goto failed_mount;
214 }
215
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000216 msblk->stream = squashfs_decompressor_setup(sb, flags);
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +0000217 if (IS_ERR(msblk->stream)) {
218 err = PTR_ERR(msblk->stream);
219 msblk->stream = NULL;
220 goto failed_mount;
221 }
222
Phillip Lougher76e002f2011-05-24 02:57:05 +0100223 /* Handle xattrs */
224 sb->s_xattr = squashfs_xattr_handlers;
225 xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
Phillip Lougher37986f62011-05-24 04:05:22 +0100226 if (xattr_id_table_start == SQUASHFS_INVALID_BLK) {
227 next_table = msblk->bytes_used;
Phillip Lougher76e002f2011-05-24 02:57:05 +0100228 goto allocate_id_index_table;
Phillip Lougher37986f62011-05-24 04:05:22 +0100229 }
Phillip Lougher76e002f2011-05-24 02:57:05 +0100230
231 /* Allocate and read xattr id lookup table */
232 msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
233 xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
234 if (IS_ERR(msblk->xattr_id_table)) {
235 ERROR("unable to read xattr id index table\n");
236 err = PTR_ERR(msblk->xattr_id_table);
237 msblk->xattr_id_table = NULL;
238 if (err != -ENOTSUPP)
239 goto failed_mount;
240 }
Phillip Lougher37986f62011-05-24 04:05:22 +0100241 next_table = msblk->xattr_table;
Phillip Lougher76e002f2011-05-24 02:57:05 +0100242
243allocate_id_index_table:
Phillip Lougher0aa66612009-01-05 08:46:25 +0000244 /* Allocate and read id index table */
245 msblk->id_table = squashfs_read_id_index_table(sb,
Phillip Lougher37986f62011-05-24 04:05:22 +0100246 le64_to_cpu(sblk->id_table_start), next_table,
247 le16_to_cpu(sblk->no_ids));
Phillip Lougher0aa66612009-01-05 08:46:25 +0000248 if (IS_ERR(msblk->id_table)) {
Phillip Lougher82de6472011-05-20 02:26:43 +0100249 ERROR("unable to read id index table\n");
Phillip Lougher0aa66612009-01-05 08:46:25 +0000250 err = PTR_ERR(msblk->id_table);
251 msblk->id_table = NULL;
252 goto failed_mount;
253 }
Phillip Lougherd5b72ce2011-05-29 00:38:46 +0100254 next_table = le64_to_cpu(msblk->id_table[0]);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000255
Phillip Lougher76e002f2011-05-24 02:57:05 +0100256 /* Handle inode lookup table */
257 lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
258 if (lookup_table_start == SQUASHFS_INVALID_BLK)
259 goto handle_fragments;
260
261 /* Allocate and read inode lookup table */
262 msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
Phillip Lougherac51a0a2011-05-24 04:15:21 +0100263 lookup_table_start, next_table, msblk->inodes);
Phillip Lougher76e002f2011-05-24 02:57:05 +0100264 if (IS_ERR(msblk->inode_lookup_table)) {
265 ERROR("unable to read inode lookup table\n");
266 err = PTR_ERR(msblk->inode_lookup_table);
267 msblk->inode_lookup_table = NULL;
268 goto failed_mount;
269 }
Phillip Lougherd5b72ce2011-05-29 00:38:46 +0100270 next_table = le64_to_cpu(msblk->inode_lookup_table[0]);
Phillip Lougher76e002f2011-05-24 02:57:05 +0100271
272 sb->s_export_op = &squashfs_export_ops;
273
274handle_fragments:
Phillip Lougher0aa66612009-01-05 08:46:25 +0000275 fragments = le32_to_cpu(sblk->fragments);
276 if (fragments == 0)
Phillip Lougher1094a4a2011-05-24 04:45:33 +0100277 goto check_directory_table;
Phillip Lougher0aa66612009-01-05 08:46:25 +0000278
279 msblk->fragment_cache = squashfs_cache_init("fragment",
280 SQUASHFS_CACHED_FRAGMENTS, msblk->block_size);
281 if (msblk->fragment_cache == NULL) {
282 err = -ENOMEM;
283 goto failed_mount;
284 }
285
286 /* Allocate and read fragment index table */
287 msblk->fragment_index = squashfs_read_fragment_index_table(sb,
Phillip Lougher1cac63c2011-05-24 04:33:34 +0100288 le64_to_cpu(sblk->fragment_table_start), next_table, fragments);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000289 if (IS_ERR(msblk->fragment_index)) {
Phillip Lougher82de6472011-05-20 02:26:43 +0100290 ERROR("unable to read fragment index table\n");
Phillip Lougher0aa66612009-01-05 08:46:25 +0000291 err = PTR_ERR(msblk->fragment_index);
292 msblk->fragment_index = NULL;
293 goto failed_mount;
294 }
Phillip Lougherd5b72ce2011-05-29 00:38:46 +0100295 next_table = le64_to_cpu(msblk->fragment_index[0]);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000296
Phillip Lougher1094a4a2011-05-24 04:45:33 +0100297check_directory_table:
298 /* Sanity check directory_table */
Phillip Loughercc37f752012-01-02 17:47:14 +0000299 if (msblk->directory_table > next_table) {
Phillip Lougher1094a4a2011-05-24 04:45:33 +0100300 err = -EINVAL;
301 goto failed_mount;
302 }
303
304 /* Sanity check inode_table */
305 if (msblk->inode_table >= msblk->directory_table) {
306 err = -EINVAL;
307 goto failed_mount;
308 }
309
310 /* allocate root */
Phillip Lougher0aa66612009-01-05 08:46:25 +0000311 root = new_inode(sb);
312 if (!root) {
313 err = -ENOMEM;
314 goto failed_mount;
315 }
316
317 err = squashfs_read_inode(root, root_inode);
318 if (err) {
Phillip Lougher1cb08e92010-04-16 01:01:36 +0100319 make_bad_inode(root);
320 iput(root);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000321 goto failed_mount;
322 }
323 insert_inode_hash(root);
324
Al Viro48fde702012-01-08 22:15:13 -0500325 sb->s_root = d_make_root(root);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000326 if (sb->s_root == NULL) {
327 ERROR("Root inode create failed\n");
328 err = -ENOMEM;
Phillip Lougher0aa66612009-01-05 08:46:25 +0000329 goto failed_mount;
330 }
331
332 TRACE("Leaving squashfs_fill_super\n");
333 kfree(sblk);
334 return 0;
335
336failed_mount:
337 squashfs_cache_delete(msblk->block_cache);
338 squashfs_cache_delete(msblk->fragment_cache);
339 squashfs_cache_delete(msblk->read_page);
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000340 squashfs_decompressor_destroy(msblk);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000341 kfree(msblk->inode_lookup_table);
342 kfree(msblk->fragment_index);
343 kfree(msblk->id_table);
Phillip Lougher4b5397d2010-05-14 20:48:47 +0100344 kfree(msblk->xattr_id_table);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000345 kfree(sb->s_fs_info);
346 sb->s_fs_info = NULL;
347 kfree(sblk);
348 return err;
Phillip Lougher0aa66612009-01-05 08:46:25 +0000349}
350
351
352static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf)
353{
354 struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info;
Coly Li2fc7f562009-04-02 16:59:42 -0700355 u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000356
357 TRACE("Entered squashfs_statfs\n");
358
359 buf->f_type = SQUASHFS_MAGIC;
360 buf->f_bsize = msblk->block_size;
361 buf->f_blocks = ((msblk->bytes_used - 1) >> msblk->block_log) + 1;
362 buf->f_bfree = buf->f_bavail = 0;
363 buf->f_files = msblk->inodes;
364 buf->f_ffree = 0;
365 buf->f_namelen = SQUASHFS_NAME_LEN;
Coly Li2fc7f562009-04-02 16:59:42 -0700366 buf->f_fsid.val[0] = (u32)id;
367 buf->f_fsid.val[1] = (u32)(id >> 32);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000368
369 return 0;
370}
371
372
373static int squashfs_remount(struct super_block *sb, int *flags, char *data)
374{
Theodore Ts'o02b99842014-03-13 10:14:33 -0400375 sync_filesystem(sb);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000376 *flags |= MS_RDONLY;
377 return 0;
378}
379
380
381static void squashfs_put_super(struct super_block *sb)
382{
383 if (sb->s_fs_info) {
384 struct squashfs_sb_info *sbi = sb->s_fs_info;
385 squashfs_cache_delete(sbi->block_cache);
386 squashfs_cache_delete(sbi->fragment_cache);
387 squashfs_cache_delete(sbi->read_page);
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000388 squashfs_decompressor_destroy(sbi);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000389 kfree(sbi->id_table);
390 kfree(sbi->fragment_index);
391 kfree(sbi->meta_index);
Phillip Lougher370ec3d2010-04-23 00:24:22 +0100392 kfree(sbi->inode_lookup_table);
Phillip Lougher4b5397d2010-05-14 20:48:47 +0100393 kfree(sbi->xattr_id_table);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000394 kfree(sb->s_fs_info);
395 sb->s_fs_info = NULL;
396 }
397}
398
399
Phillip Lougher003a3192011-02-28 18:43:48 +0000400static struct dentry *squashfs_mount(struct file_system_type *fs_type,
401 int flags, const char *dev_name, void *data)
Phillip Lougher0aa66612009-01-05 08:46:25 +0000402{
Al Viro152a0832010-07-25 00:46:55 +0400403 return mount_bdev(fs_type, flags, dev_name, data, squashfs_fill_super);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000404}
405
406
407static struct kmem_cache *squashfs_inode_cachep;
408
409
410static void init_once(void *foo)
411{
412 struct squashfs_inode_info *ei = foo;
413
414 inode_init_once(&ei->vfs_inode);
415}
416
417
418static int __init init_inodecache(void)
419{
420 squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache",
421 sizeof(struct squashfs_inode_info), 0,
Vladimir Davydov5d097052016-01-14 15:18:21 -0800422 SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
423 init_once);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000424
425 return squashfs_inode_cachep ? 0 : -ENOMEM;
426}
427
428
429static void destroy_inodecache(void)
430{
Kirill A. Shutemov8c0a8532012-09-26 11:33:07 +1000431 /*
432 * Make sure all delayed rcu free inodes are flushed before we
433 * destroy cache.
434 */
435 rcu_barrier();
Phillip Lougher0aa66612009-01-05 08:46:25 +0000436 kmem_cache_destroy(squashfs_inode_cachep);
437}
438
439
440static int __init init_squashfs_fs(void)
441{
442 int err = init_inodecache();
443
444 if (err)
445 return err;
446
447 err = register_filesystem(&squashfs_fs_type);
448 if (err) {
449 destroy_inodecache();
450 return err;
451 }
452
Fabian Frederickc811f5f2014-08-06 16:03:52 -0700453 pr_info("version 4.0 (2009/01/31) Phillip Lougher\n");
Phillip Lougher0aa66612009-01-05 08:46:25 +0000454
455 return 0;
456}
457
458
459static void __exit exit_squashfs_fs(void)
460{
461 unregister_filesystem(&squashfs_fs_type);
462 destroy_inodecache();
463}
464
465
466static struct inode *squashfs_alloc_inode(struct super_block *sb)
467{
468 struct squashfs_inode_info *ei =
469 kmem_cache_alloc(squashfs_inode_cachep, GFP_KERNEL);
470
471 return ei ? &ei->vfs_inode : NULL;
472}
473
474
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100475static void squashfs_i_callback(struct rcu_head *head)
476{
477 struct inode *inode = container_of(head, struct inode, i_rcu);
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100478 kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode));
479}
480
Phillip Lougher0aa66612009-01-05 08:46:25 +0000481static void squashfs_destroy_inode(struct inode *inode)
482{
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100483 call_rcu(&inode->i_rcu, squashfs_i_callback);
Phillip Lougher0aa66612009-01-05 08:46:25 +0000484}
485
486
487static struct file_system_type squashfs_fs_type = {
488 .owner = THIS_MODULE,
489 .name = "squashfs",
Al Viro152a0832010-07-25 00:46:55 +0400490 .mount = squashfs_mount,
Phillip Lougher0aa66612009-01-05 08:46:25 +0000491 .kill_sb = kill_block_super,
492 .fs_flags = FS_REQUIRES_DEV
493};
Eric W. Biederman3e64fe52013-03-11 07:05:42 -0700494MODULE_ALIAS_FS("squashfs");
Phillip Lougher0aa66612009-01-05 08:46:25 +0000495
Alexey Dobriyanb87221d2009-09-21 17:01:09 -0700496static const struct super_operations squashfs_super_ops = {
Phillip Lougher0aa66612009-01-05 08:46:25 +0000497 .alloc_inode = squashfs_alloc_inode,
498 .destroy_inode = squashfs_destroy_inode,
499 .statfs = squashfs_statfs,
500 .put_super = squashfs_put_super,
501 .remount_fs = squashfs_remount
502};
503
504module_init(init_squashfs_fs);
505module_exit(exit_squashfs_fs);
506MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem");
Phillip Lougherd7f2ff62011-05-26 10:39:56 +0100507MODULE_AUTHOR("Phillip Lougher <phillip@squashfs.org.uk>");
Phillip Lougher0aa66612009-01-05 08:46:25 +0000508MODULE_LICENSE("GPL");