Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Squashfs - a compressed read only filesystem for Linux |
| 3 | * |
| 4 | * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 |
Phillip Lougher | d7f2ff6 | 2011-05-26 10:39:56 +0100 | [diff] [blame] | 5 | * Phillip Lougher <phillip@squashfs.org.uk> |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 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 | * 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 Frederick | c811f5f | 2014-08-06 16:03:52 -0700 | [diff] [blame] | 30 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 31 | |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 32 | #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 Feng | 1bcbf31 | 2009-01-15 13:51:03 -0800 | [diff] [blame] | 39 | #include <linux/magic.h> |
Phillip Lougher | 4b5397d | 2010-05-14 20:48:47 +0100 | [diff] [blame] | 40 | #include <linux/xattr.h> |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 41 | |
| 42 | #include "squashfs_fs.h" |
| 43 | #include "squashfs_fs_sb.h" |
| 44 | #include "squashfs_fs_i.h" |
| 45 | #include "squashfs.h" |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 46 | #include "decompressor.h" |
Phillip Lougher | 01e5b4e | 2010-05-17 19:39:02 +0100 | [diff] [blame] | 47 | #include "xattr.h" |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 48 | |
| 49 | static struct file_system_type squashfs_fs_type; |
Alexey Dobriyan | b87221d | 2009-09-21 17:01:09 -0700 | [diff] [blame] | 50 | static const struct super_operations squashfs_super_ops; |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 51 | |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 52 | static const struct squashfs_decompressor *supported_squashfs_filesystem(short |
| 53 | major, short minor, short id) |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 54 | { |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 55 | const struct squashfs_decompressor *decompressor; |
| 56 | |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 57 | if (major < SQUASHFS_MAJOR) { |
| 58 | ERROR("Major/Minor mismatch, older Squashfs %d.%d " |
| 59 | "filesystems are unsupported\n", major, minor); |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 60 | return NULL; |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 61 | } 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 Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 65 | return NULL; |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 66 | } |
| 67 | |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 68 | 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 Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 74 | |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 75 | return decompressor; |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 76 | } |
| 77 | |
| 78 | |
| 79 | static 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 Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 83 | struct inode *root; |
| 84 | long long root_inode; |
| 85 | unsigned short flags; |
| 86 | unsigned int fragments; |
Phillip Lougher | 37986f6 | 2011-05-24 04:05:22 +0100 | [diff] [blame] | 87 | u64 lookup_table_start, xattr_id_table_start, next_table; |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 88 | 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 Lougher | 7657cac | 2011-10-22 01:34:48 +0100 | [diff] [blame] | 99 | msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 100 | msblk->devblksize_log2 = ffz(~msblk->devblksize); |
| 101 | |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 102 | 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 Lougher | 82de647 | 2011-05-20 02:26:43 +0100 | [diff] [blame] | 111 | sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk)); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 112 | |
Phillip Lougher | 82de647 | 2011-05-20 02:26:43 +0100 | [diff] [blame] | 113 | if (IS_ERR(sblk)) { |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 114 | ERROR("unable to read squashfs_super_block\n"); |
Phillip Lougher | 82de647 | 2011-05-20 02:26:43 +0100 | [diff] [blame] | 115 | err = PTR_ERR(sblk); |
| 116 | sblk = NULL; |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 117 | goto failed_mount; |
| 118 | } |
| 119 | |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 120 | err = -EINVAL; |
| 121 | |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 122 | /* 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 Monakhov | a1c6f057 | 2015-04-13 16:31:37 +0400 | [diff] [blame] | 126 | ERROR("Can't find a SQUASHFS superblock on %pg\n", |
| 127 | sb->s_bdev); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 128 | goto failed_mount; |
| 129 | } |
| 130 | |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 131 | /* Check the MAJOR & MINOR versions and lookup compression type */ |
| 132 | msblk->decompressor = supported_squashfs_filesystem( |
| 133 | le16_to_cpu(sblk->s_major), |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 134 | le16_to_cpu(sblk->s_minor), |
| 135 | le16_to_cpu(sblk->compression)); |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 136 | if (msblk->decompressor == NULL) |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 137 | goto failed_mount; |
| 138 | |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 139 | /* 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 Lougher | fffb47b | 2009-05-13 02:59:26 +0100 | [diff] [blame] | 151 | /* |
| 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 Lougher | 4b0180a | 2012-03-09 03:02:59 +0000 | [diff] [blame] | 161 | /* Check block log for sanity */ |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 162 | msblk->block_log = le16_to_cpu(sblk->block_log); |
| 163 | if (msblk->block_log > SQUASHFS_FILE_MAX_LOG) |
| 164 | goto failed_mount; |
| 165 | |
Phillip Lougher | 4b0180a | 2012-03-09 03:02:59 +0000 | [diff] [blame] | 166 | /* Check that block_size and block_log match */ |
| 167 | if (msblk->block_size != (1 << msblk->block_log)) |
| 168 | goto failed_mount; |
| 169 | |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 170 | /* 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 Monakhov | a1c6f057 | 2015-04-13 16:31:37 +0400 | [diff] [blame] | 180 | TRACE("Found valid superblock on %pg\n", sb->s_bdev); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 181 | 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 Lougher | 9508c6b | 2013-11-13 02:56:26 +0000 | [diff] [blame] | 209 | msblk->read_page = squashfs_cache_init("data", |
| 210 | squashfs_max_decompressors(), msblk->block_size); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 211 | if (msblk->read_page == NULL) { |
| 212 | ERROR("Failed to allocate read_page block\n"); |
| 213 | goto failed_mount; |
| 214 | } |
| 215 | |
Phillip Lougher | 9508c6b | 2013-11-13 02:56:26 +0000 | [diff] [blame] | 216 | msblk->stream = squashfs_decompressor_setup(sb, flags); |
Phillip Lougher | b7fc0ff | 2011-02-28 01:45:42 +0000 | [diff] [blame] | 217 | if (IS_ERR(msblk->stream)) { |
| 218 | err = PTR_ERR(msblk->stream); |
| 219 | msblk->stream = NULL; |
| 220 | goto failed_mount; |
| 221 | } |
| 222 | |
Phillip Lougher | 76e002f | 2011-05-24 02:57:05 +0100 | [diff] [blame] | 223 | /* Handle xattrs */ |
| 224 | sb->s_xattr = squashfs_xattr_handlers; |
| 225 | xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start); |
Phillip Lougher | 37986f6 | 2011-05-24 04:05:22 +0100 | [diff] [blame] | 226 | if (xattr_id_table_start == SQUASHFS_INVALID_BLK) { |
| 227 | next_table = msblk->bytes_used; |
Phillip Lougher | 76e002f | 2011-05-24 02:57:05 +0100 | [diff] [blame] | 228 | goto allocate_id_index_table; |
Phillip Lougher | 37986f6 | 2011-05-24 04:05:22 +0100 | [diff] [blame] | 229 | } |
Phillip Lougher | 76e002f | 2011-05-24 02:57:05 +0100 | [diff] [blame] | 230 | |
| 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 Lougher | 37986f6 | 2011-05-24 04:05:22 +0100 | [diff] [blame] | 241 | next_table = msblk->xattr_table; |
Phillip Lougher | 76e002f | 2011-05-24 02:57:05 +0100 | [diff] [blame] | 242 | |
| 243 | allocate_id_index_table: |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 244 | /* Allocate and read id index table */ |
| 245 | msblk->id_table = squashfs_read_id_index_table(sb, |
Phillip Lougher | 37986f6 | 2011-05-24 04:05:22 +0100 | [diff] [blame] | 246 | le64_to_cpu(sblk->id_table_start), next_table, |
| 247 | le16_to_cpu(sblk->no_ids)); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 248 | if (IS_ERR(msblk->id_table)) { |
Phillip Lougher | 82de647 | 2011-05-20 02:26:43 +0100 | [diff] [blame] | 249 | ERROR("unable to read id index table\n"); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 250 | err = PTR_ERR(msblk->id_table); |
| 251 | msblk->id_table = NULL; |
| 252 | goto failed_mount; |
| 253 | } |
Phillip Lougher | d5b72ce | 2011-05-29 00:38:46 +0100 | [diff] [blame] | 254 | next_table = le64_to_cpu(msblk->id_table[0]); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 255 | |
Phillip Lougher | 76e002f | 2011-05-24 02:57:05 +0100 | [diff] [blame] | 256 | /* 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 Lougher | ac51a0a | 2011-05-24 04:15:21 +0100 | [diff] [blame] | 263 | lookup_table_start, next_table, msblk->inodes); |
Phillip Lougher | 76e002f | 2011-05-24 02:57:05 +0100 | [diff] [blame] | 264 | 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 Lougher | d5b72ce | 2011-05-29 00:38:46 +0100 | [diff] [blame] | 270 | next_table = le64_to_cpu(msblk->inode_lookup_table[0]); |
Phillip Lougher | 76e002f | 2011-05-24 02:57:05 +0100 | [diff] [blame] | 271 | |
| 272 | sb->s_export_op = &squashfs_export_ops; |
| 273 | |
| 274 | handle_fragments: |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 275 | fragments = le32_to_cpu(sblk->fragments); |
| 276 | if (fragments == 0) |
Phillip Lougher | 1094a4a | 2011-05-24 04:45:33 +0100 | [diff] [blame] | 277 | goto check_directory_table; |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 278 | |
| 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 Lougher | 1cac63c | 2011-05-24 04:33:34 +0100 | [diff] [blame] | 288 | le64_to_cpu(sblk->fragment_table_start), next_table, fragments); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 289 | if (IS_ERR(msblk->fragment_index)) { |
Phillip Lougher | 82de647 | 2011-05-20 02:26:43 +0100 | [diff] [blame] | 290 | ERROR("unable to read fragment index table\n"); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 291 | err = PTR_ERR(msblk->fragment_index); |
| 292 | msblk->fragment_index = NULL; |
| 293 | goto failed_mount; |
| 294 | } |
Phillip Lougher | d5b72ce | 2011-05-29 00:38:46 +0100 | [diff] [blame] | 295 | next_table = le64_to_cpu(msblk->fragment_index[0]); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 296 | |
Phillip Lougher | 1094a4a | 2011-05-24 04:45:33 +0100 | [diff] [blame] | 297 | check_directory_table: |
| 298 | /* Sanity check directory_table */ |
Phillip Lougher | cc37f75 | 2012-01-02 17:47:14 +0000 | [diff] [blame] | 299 | if (msblk->directory_table > next_table) { |
Phillip Lougher | 1094a4a | 2011-05-24 04:45:33 +0100 | [diff] [blame] | 300 | 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 Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 311 | 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 Lougher | 1cb08e9 | 2010-04-16 01:01:36 +0100 | [diff] [blame] | 319 | make_bad_inode(root); |
| 320 | iput(root); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 321 | goto failed_mount; |
| 322 | } |
| 323 | insert_inode_hash(root); |
| 324 | |
Al Viro | 48fde70 | 2012-01-08 22:15:13 -0500 | [diff] [blame] | 325 | sb->s_root = d_make_root(root); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 326 | if (sb->s_root == NULL) { |
| 327 | ERROR("Root inode create failed\n"); |
| 328 | err = -ENOMEM; |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 329 | goto failed_mount; |
| 330 | } |
| 331 | |
| 332 | TRACE("Leaving squashfs_fill_super\n"); |
| 333 | kfree(sblk); |
| 334 | return 0; |
| 335 | |
| 336 | failed_mount: |
| 337 | squashfs_cache_delete(msblk->block_cache); |
| 338 | squashfs_cache_delete(msblk->fragment_cache); |
| 339 | squashfs_cache_delete(msblk->read_page); |
Phillip Lougher | 9508c6b | 2013-11-13 02:56:26 +0000 | [diff] [blame] | 340 | squashfs_decompressor_destroy(msblk); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 341 | kfree(msblk->inode_lookup_table); |
| 342 | kfree(msblk->fragment_index); |
| 343 | kfree(msblk->id_table); |
Phillip Lougher | 4b5397d | 2010-05-14 20:48:47 +0100 | [diff] [blame] | 344 | kfree(msblk->xattr_id_table); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 345 | kfree(sb->s_fs_info); |
| 346 | sb->s_fs_info = NULL; |
| 347 | kfree(sblk); |
| 348 | return err; |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 349 | } |
| 350 | |
| 351 | |
| 352 | static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 353 | { |
| 354 | struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info; |
Coly Li | 2fc7f56 | 2009-04-02 16:59:42 -0700 | [diff] [blame] | 355 | u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 356 | |
| 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 Li | 2fc7f56 | 2009-04-02 16:59:42 -0700 | [diff] [blame] | 366 | buf->f_fsid.val[0] = (u32)id; |
| 367 | buf->f_fsid.val[1] = (u32)(id >> 32); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 368 | |
| 369 | return 0; |
| 370 | } |
| 371 | |
| 372 | |
| 373 | static int squashfs_remount(struct super_block *sb, int *flags, char *data) |
| 374 | { |
Theodore Ts'o | 02b9984 | 2014-03-13 10:14:33 -0400 | [diff] [blame] | 375 | sync_filesystem(sb); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 376 | *flags |= MS_RDONLY; |
| 377 | return 0; |
| 378 | } |
| 379 | |
| 380 | |
| 381 | static 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 Lougher | 9508c6b | 2013-11-13 02:56:26 +0000 | [diff] [blame] | 388 | squashfs_decompressor_destroy(sbi); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 389 | kfree(sbi->id_table); |
| 390 | kfree(sbi->fragment_index); |
| 391 | kfree(sbi->meta_index); |
Phillip Lougher | 370ec3d | 2010-04-23 00:24:22 +0100 | [diff] [blame] | 392 | kfree(sbi->inode_lookup_table); |
Phillip Lougher | 4b5397d | 2010-05-14 20:48:47 +0100 | [diff] [blame] | 393 | kfree(sbi->xattr_id_table); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 394 | kfree(sb->s_fs_info); |
| 395 | sb->s_fs_info = NULL; |
| 396 | } |
| 397 | } |
| 398 | |
| 399 | |
Phillip Lougher | 003a319 | 2011-02-28 18:43:48 +0000 | [diff] [blame] | 400 | static struct dentry *squashfs_mount(struct file_system_type *fs_type, |
| 401 | int flags, const char *dev_name, void *data) |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 402 | { |
Al Viro | 152a083 | 2010-07-25 00:46:55 +0400 | [diff] [blame] | 403 | return mount_bdev(fs_type, flags, dev_name, data, squashfs_fill_super); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 404 | } |
| 405 | |
| 406 | |
| 407 | static struct kmem_cache *squashfs_inode_cachep; |
| 408 | |
| 409 | |
| 410 | static void init_once(void *foo) |
| 411 | { |
| 412 | struct squashfs_inode_info *ei = foo; |
| 413 | |
| 414 | inode_init_once(&ei->vfs_inode); |
| 415 | } |
| 416 | |
| 417 | |
| 418 | static int __init init_inodecache(void) |
| 419 | { |
| 420 | squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache", |
| 421 | sizeof(struct squashfs_inode_info), 0, |
| 422 | SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT, init_once); |
| 423 | |
| 424 | return squashfs_inode_cachep ? 0 : -ENOMEM; |
| 425 | } |
| 426 | |
| 427 | |
| 428 | static void destroy_inodecache(void) |
| 429 | { |
Kirill A. Shutemov | 8c0a853 | 2012-09-26 11:33:07 +1000 | [diff] [blame] | 430 | /* |
| 431 | * Make sure all delayed rcu free inodes are flushed before we |
| 432 | * destroy cache. |
| 433 | */ |
| 434 | rcu_barrier(); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 435 | kmem_cache_destroy(squashfs_inode_cachep); |
| 436 | } |
| 437 | |
| 438 | |
| 439 | static int __init init_squashfs_fs(void) |
| 440 | { |
| 441 | int err = init_inodecache(); |
| 442 | |
| 443 | if (err) |
| 444 | return err; |
| 445 | |
| 446 | err = register_filesystem(&squashfs_fs_type); |
| 447 | if (err) { |
| 448 | destroy_inodecache(); |
| 449 | return err; |
| 450 | } |
| 451 | |
Fabian Frederick | c811f5f | 2014-08-06 16:03:52 -0700 | [diff] [blame] | 452 | pr_info("version 4.0 (2009/01/31) Phillip Lougher\n"); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 453 | |
| 454 | return 0; |
| 455 | } |
| 456 | |
| 457 | |
| 458 | static void __exit exit_squashfs_fs(void) |
| 459 | { |
| 460 | unregister_filesystem(&squashfs_fs_type); |
| 461 | destroy_inodecache(); |
| 462 | } |
| 463 | |
| 464 | |
| 465 | static struct inode *squashfs_alloc_inode(struct super_block *sb) |
| 466 | { |
| 467 | struct squashfs_inode_info *ei = |
| 468 | kmem_cache_alloc(squashfs_inode_cachep, GFP_KERNEL); |
| 469 | |
| 470 | return ei ? &ei->vfs_inode : NULL; |
| 471 | } |
| 472 | |
| 473 | |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 474 | static void squashfs_i_callback(struct rcu_head *head) |
| 475 | { |
| 476 | struct inode *inode = container_of(head, struct inode, i_rcu); |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 477 | kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode)); |
| 478 | } |
| 479 | |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 480 | static void squashfs_destroy_inode(struct inode *inode) |
| 481 | { |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 482 | call_rcu(&inode->i_rcu, squashfs_i_callback); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 483 | } |
| 484 | |
| 485 | |
| 486 | static struct file_system_type squashfs_fs_type = { |
| 487 | .owner = THIS_MODULE, |
| 488 | .name = "squashfs", |
Al Viro | 152a083 | 2010-07-25 00:46:55 +0400 | [diff] [blame] | 489 | .mount = squashfs_mount, |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 490 | .kill_sb = kill_block_super, |
| 491 | .fs_flags = FS_REQUIRES_DEV |
| 492 | }; |
Eric W. Biederman | 3e64fe5 | 2013-03-11 07:05:42 -0700 | [diff] [blame] | 493 | MODULE_ALIAS_FS("squashfs"); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 494 | |
Alexey Dobriyan | b87221d | 2009-09-21 17:01:09 -0700 | [diff] [blame] | 495 | static const struct super_operations squashfs_super_ops = { |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 496 | .alloc_inode = squashfs_alloc_inode, |
| 497 | .destroy_inode = squashfs_destroy_inode, |
| 498 | .statfs = squashfs_statfs, |
| 499 | .put_super = squashfs_put_super, |
| 500 | .remount_fs = squashfs_remount |
| 501 | }; |
| 502 | |
| 503 | module_init(init_squashfs_fs); |
| 504 | module_exit(exit_squashfs_fs); |
| 505 | MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem"); |
Phillip Lougher | d7f2ff6 | 2011-05-26 10:39:56 +0100 | [diff] [blame] | 506 | MODULE_AUTHOR("Phillip Lougher <phillip@squashfs.org.uk>"); |
Phillip Lougher | 0aa6661 | 2009-01-05 08:46:25 +0000 | [diff] [blame] | 507 | MODULE_LICENSE("GPL"); |