Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/sysv/inode.c |
| 3 | * |
| 4 | * minix/inode.c |
| 5 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 6 | * |
| 7 | * xenix/inode.c |
| 8 | * Copyright (C) 1992 Doug Evans |
| 9 | * |
| 10 | * coh/inode.c |
| 11 | * Copyright (C) 1993 Pascal Haible, Bruno Haible |
| 12 | * |
| 13 | * sysv/inode.c |
| 14 | * Copyright (C) 1993 Paul B. Monday |
| 15 | * |
| 16 | * sysv/inode.c |
| 17 | * Copyright (C) 1993 Bruno Haible |
| 18 | * Copyright (C) 1997, 1998 Krzysztof G. Baranowski |
| 19 | * |
| 20 | * This file contains code for read/parsing the superblock. |
| 21 | */ |
| 22 | |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/init.h> |
| 25 | #include <linux/slab.h> |
| 26 | #include <linux/buffer_head.h> |
| 27 | #include "sysv.h" |
| 28 | |
| 29 | /* |
| 30 | * The following functions try to recognize specific filesystems. |
| 31 | * |
| 32 | * We recognize: |
| 33 | * - Xenix FS by its magic number. |
| 34 | * - SystemV FS by its magic number. |
| 35 | * - Coherent FS by its funny fname/fpack field. |
| 36 | * - SCO AFS by s_nfree == 0xffff |
| 37 | * - V7 FS has no distinguishing features. |
| 38 | * |
| 39 | * We discriminate among SystemV4 and SystemV2 FS by the assumption that |
| 40 | * the time stamp is not < 01-01-1980. |
| 41 | */ |
| 42 | |
| 43 | enum { |
| 44 | JAN_1_1980 = (10*365 + 2) * 24 * 60 * 60 |
| 45 | }; |
| 46 | |
| 47 | static void detected_xenix(struct sysv_sb_info *sbi) |
| 48 | { |
| 49 | struct buffer_head *bh1 = sbi->s_bh1; |
| 50 | struct buffer_head *bh2 = sbi->s_bh2; |
| 51 | struct xenix_super_block * sbd1; |
| 52 | struct xenix_super_block * sbd2; |
| 53 | |
| 54 | if (bh1 != bh2) |
| 55 | sbd1 = sbd2 = (struct xenix_super_block *) bh1->b_data; |
| 56 | else { |
| 57 | /* block size = 512, so bh1 != bh2 */ |
| 58 | sbd1 = (struct xenix_super_block *) bh1->b_data; |
| 59 | sbd2 = (struct xenix_super_block *) (bh2->b_data - 512); |
| 60 | } |
| 61 | |
| 62 | sbi->s_link_max = XENIX_LINK_MAX; |
| 63 | sbi->s_fic_size = XENIX_NICINOD; |
| 64 | sbi->s_flc_size = XENIX_NICFREE; |
| 65 | sbi->s_sbd1 = (char *)sbd1; |
| 66 | sbi->s_sbd2 = (char *)sbd2; |
| 67 | sbi->s_sb_fic_count = &sbd1->s_ninode; |
| 68 | sbi->s_sb_fic_inodes = &sbd1->s_inode[0]; |
| 69 | sbi->s_sb_total_free_inodes = &sbd2->s_tinode; |
| 70 | sbi->s_bcache_count = &sbd1->s_nfree; |
| 71 | sbi->s_bcache = &sbd1->s_free[0]; |
| 72 | sbi->s_free_blocks = &sbd2->s_tfree; |
| 73 | sbi->s_sb_time = &sbd2->s_time; |
| 74 | sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd1->s_isize); |
| 75 | sbi->s_nzones = fs32_to_cpu(sbi, sbd1->s_fsize); |
| 76 | } |
| 77 | |
| 78 | static void detected_sysv4(struct sysv_sb_info *sbi) |
| 79 | { |
| 80 | struct sysv4_super_block * sbd; |
| 81 | struct buffer_head *bh1 = sbi->s_bh1; |
| 82 | struct buffer_head *bh2 = sbi->s_bh2; |
| 83 | |
| 84 | if (bh1 == bh2) |
| 85 | sbd = (struct sysv4_super_block *) (bh1->b_data + BLOCK_SIZE/2); |
| 86 | else |
| 87 | sbd = (struct sysv4_super_block *) bh2->b_data; |
| 88 | |
| 89 | sbi->s_link_max = SYSV_LINK_MAX; |
| 90 | sbi->s_fic_size = SYSV_NICINOD; |
| 91 | sbi->s_flc_size = SYSV_NICFREE; |
| 92 | sbi->s_sbd1 = (char *)sbd; |
| 93 | sbi->s_sbd2 = (char *)sbd; |
| 94 | sbi->s_sb_fic_count = &sbd->s_ninode; |
| 95 | sbi->s_sb_fic_inodes = &sbd->s_inode[0]; |
| 96 | sbi->s_sb_total_free_inodes = &sbd->s_tinode; |
| 97 | sbi->s_bcache_count = &sbd->s_nfree; |
| 98 | sbi->s_bcache = &sbd->s_free[0]; |
| 99 | sbi->s_free_blocks = &sbd->s_tfree; |
| 100 | sbi->s_sb_time = &sbd->s_time; |
| 101 | sbi->s_sb_state = &sbd->s_state; |
| 102 | sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize); |
| 103 | sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize); |
| 104 | } |
| 105 | |
| 106 | static void detected_sysv2(struct sysv_sb_info *sbi) |
| 107 | { |
| 108 | struct sysv2_super_block *sbd; |
| 109 | struct buffer_head *bh1 = sbi->s_bh1; |
| 110 | struct buffer_head *bh2 = sbi->s_bh2; |
| 111 | |
| 112 | if (bh1 == bh2) |
| 113 | sbd = (struct sysv2_super_block *) (bh1->b_data + BLOCK_SIZE/2); |
| 114 | else |
| 115 | sbd = (struct sysv2_super_block *) bh2->b_data; |
| 116 | |
| 117 | sbi->s_link_max = SYSV_LINK_MAX; |
| 118 | sbi->s_fic_size = SYSV_NICINOD; |
| 119 | sbi->s_flc_size = SYSV_NICFREE; |
| 120 | sbi->s_sbd1 = (char *)sbd; |
| 121 | sbi->s_sbd2 = (char *)sbd; |
| 122 | sbi->s_sb_fic_count = &sbd->s_ninode; |
| 123 | sbi->s_sb_fic_inodes = &sbd->s_inode[0]; |
| 124 | sbi->s_sb_total_free_inodes = &sbd->s_tinode; |
| 125 | sbi->s_bcache_count = &sbd->s_nfree; |
| 126 | sbi->s_bcache = &sbd->s_free[0]; |
| 127 | sbi->s_free_blocks = &sbd->s_tfree; |
| 128 | sbi->s_sb_time = &sbd->s_time; |
| 129 | sbi->s_sb_state = &sbd->s_state; |
| 130 | sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize); |
| 131 | sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize); |
| 132 | } |
| 133 | |
| 134 | static void detected_coherent(struct sysv_sb_info *sbi) |
| 135 | { |
| 136 | struct coh_super_block * sbd; |
| 137 | struct buffer_head *bh1 = sbi->s_bh1; |
| 138 | |
| 139 | sbd = (struct coh_super_block *) bh1->b_data; |
| 140 | |
| 141 | sbi->s_link_max = COH_LINK_MAX; |
| 142 | sbi->s_fic_size = COH_NICINOD; |
| 143 | sbi->s_flc_size = COH_NICFREE; |
| 144 | sbi->s_sbd1 = (char *)sbd; |
| 145 | sbi->s_sbd2 = (char *)sbd; |
| 146 | sbi->s_sb_fic_count = &sbd->s_ninode; |
| 147 | sbi->s_sb_fic_inodes = &sbd->s_inode[0]; |
| 148 | sbi->s_sb_total_free_inodes = &sbd->s_tinode; |
| 149 | sbi->s_bcache_count = &sbd->s_nfree; |
| 150 | sbi->s_bcache = &sbd->s_free[0]; |
| 151 | sbi->s_free_blocks = &sbd->s_tfree; |
| 152 | sbi->s_sb_time = &sbd->s_time; |
| 153 | sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize); |
| 154 | sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize); |
| 155 | } |
| 156 | |
| 157 | static void detected_v7(struct sysv_sb_info *sbi) |
| 158 | { |
| 159 | struct buffer_head *bh2 = sbi->s_bh2; |
| 160 | struct v7_super_block *sbd = (struct v7_super_block *)bh2->b_data; |
| 161 | |
| 162 | sbi->s_link_max = V7_LINK_MAX; |
| 163 | sbi->s_fic_size = V7_NICINOD; |
| 164 | sbi->s_flc_size = V7_NICFREE; |
| 165 | sbi->s_sbd1 = (char *)sbd; |
| 166 | sbi->s_sbd2 = (char *)sbd; |
| 167 | sbi->s_sb_fic_count = &sbd->s_ninode; |
| 168 | sbi->s_sb_fic_inodes = &sbd->s_inode[0]; |
| 169 | sbi->s_sb_total_free_inodes = &sbd->s_tinode; |
| 170 | sbi->s_bcache_count = &sbd->s_nfree; |
| 171 | sbi->s_bcache = &sbd->s_free[0]; |
| 172 | sbi->s_free_blocks = &sbd->s_tfree; |
| 173 | sbi->s_sb_time = &sbd->s_time; |
| 174 | sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize); |
| 175 | sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize); |
| 176 | } |
| 177 | |
| 178 | static int detect_xenix(struct sysv_sb_info *sbi, struct buffer_head *bh) |
| 179 | { |
| 180 | struct xenix_super_block *sbd = (struct xenix_super_block *)bh->b_data; |
| 181 | if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0x2b5544)) |
| 182 | sbi->s_bytesex = BYTESEX_LE; |
| 183 | else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0x2b5544)) |
| 184 | sbi->s_bytesex = BYTESEX_BE; |
| 185 | else |
| 186 | return 0; |
| 187 | switch (fs32_to_cpu(sbi, sbd->s_type)) { |
| 188 | case 1: |
| 189 | sbi->s_type = FSTYPE_XENIX; |
| 190 | return 1; |
| 191 | case 2: |
| 192 | sbi->s_type = FSTYPE_XENIX; |
| 193 | return 2; |
| 194 | default: |
| 195 | return 0; |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | static int detect_sysv(struct sysv_sb_info *sbi, struct buffer_head *bh) |
| 200 | { |
| 201 | struct super_block *sb = sbi->s_sb; |
| 202 | /* All relevant fields are at the same offsets in R2 and R4 */ |
| 203 | struct sysv4_super_block * sbd; |
| 204 | u32 type; |
| 205 | |
| 206 | sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2); |
| 207 | if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0xfd187e20)) |
| 208 | sbi->s_bytesex = BYTESEX_LE; |
| 209 | else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0xfd187e20)) |
| 210 | sbi->s_bytesex = BYTESEX_BE; |
| 211 | else |
| 212 | return 0; |
| 213 | |
| 214 | type = fs32_to_cpu(sbi, sbd->s_type); |
| 215 | |
| 216 | if (fs16_to_cpu(sbi, sbd->s_nfree) == 0xffff) { |
| 217 | sbi->s_type = FSTYPE_AFS; |
| 218 | sbi->s_forced_ro = 1; |
| 219 | if (!(sb->s_flags & MS_RDONLY)) { |
| 220 | printk("SysV FS: SCO EAFS on %s detected, " |
| 221 | "forcing read-only mode.\n", |
| 222 | sb->s_id); |
| 223 | } |
| 224 | return type; |
| 225 | } |
| 226 | |
| 227 | if (fs32_to_cpu(sbi, sbd->s_time) < JAN_1_1980) { |
| 228 | /* this is likely to happen on SystemV2 FS */ |
| 229 | if (type > 3 || type < 1) |
| 230 | return 0; |
| 231 | sbi->s_type = FSTYPE_SYSV2; |
| 232 | return type; |
| 233 | } |
| 234 | if ((type > 3 || type < 1) && (type > 0x30 || type < 0x10)) |
| 235 | return 0; |
| 236 | |
| 237 | /* On Interactive Unix (ISC) Version 4.0/3.x s_type field = 0x10, |
| 238 | 0x20 or 0x30 indicates that symbolic links and the 14-character |
| 239 | filename limit is gone. Due to lack of information about this |
| 240 | feature read-only mode seems to be a reasonable approach... -KGB */ |
| 241 | |
| 242 | if (type >= 0x10) { |
| 243 | printk("SysV FS: can't handle long file names on %s, " |
| 244 | "forcing read-only mode.\n", sb->s_id); |
| 245 | sbi->s_forced_ro = 1; |
| 246 | } |
| 247 | |
| 248 | sbi->s_type = FSTYPE_SYSV4; |
| 249 | return type >= 0x10 ? type >> 4 : type; |
| 250 | } |
| 251 | |
| 252 | static int detect_coherent(struct sysv_sb_info *sbi, struct buffer_head *bh) |
| 253 | { |
| 254 | struct coh_super_block * sbd; |
| 255 | |
| 256 | sbd = (struct coh_super_block *) (bh->b_data + BLOCK_SIZE/2); |
| 257 | if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6)) |
| 258 | || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6))) |
| 259 | return 0; |
| 260 | sbi->s_bytesex = BYTESEX_PDP; |
| 261 | sbi->s_type = FSTYPE_COH; |
| 262 | return 1; |
| 263 | } |
| 264 | |
| 265 | static int detect_sysv_odd(struct sysv_sb_info *sbi, struct buffer_head *bh) |
| 266 | { |
| 267 | int size = detect_sysv(sbi, bh); |
| 268 | |
| 269 | return size>2 ? 0 : size; |
| 270 | } |
| 271 | |
| 272 | static struct { |
| 273 | int block; |
| 274 | int (*test)(struct sysv_sb_info *, struct buffer_head *); |
| 275 | } flavours[] = { |
| 276 | {1, detect_xenix}, |
| 277 | {0, detect_sysv}, |
| 278 | {0, detect_coherent}, |
| 279 | {9, detect_sysv_odd}, |
| 280 | {15,detect_sysv_odd}, |
| 281 | {18,detect_sysv}, |
| 282 | }; |
| 283 | |
| 284 | static char *flavour_names[] = { |
| 285 | [FSTYPE_XENIX] = "Xenix", |
| 286 | [FSTYPE_SYSV4] = "SystemV", |
| 287 | [FSTYPE_SYSV2] = "SystemV Release 2", |
| 288 | [FSTYPE_COH] = "Coherent", |
| 289 | [FSTYPE_V7] = "V7", |
| 290 | [FSTYPE_AFS] = "AFS", |
| 291 | }; |
| 292 | |
| 293 | static void (*flavour_setup[])(struct sysv_sb_info *) = { |
| 294 | [FSTYPE_XENIX] = detected_xenix, |
| 295 | [FSTYPE_SYSV4] = detected_sysv4, |
| 296 | [FSTYPE_SYSV2] = detected_sysv2, |
| 297 | [FSTYPE_COH] = detected_coherent, |
| 298 | [FSTYPE_V7] = detected_v7, |
| 299 | [FSTYPE_AFS] = detected_sysv4, |
| 300 | }; |
| 301 | |
| 302 | static int complete_read_super(struct super_block *sb, int silent, int size) |
| 303 | { |
| 304 | struct sysv_sb_info *sbi = SYSV_SB(sb); |
| 305 | struct inode *root_inode; |
| 306 | char *found = flavour_names[sbi->s_type]; |
| 307 | u_char n_bits = size+8; |
| 308 | int bsize = 1 << n_bits; |
| 309 | int bsize_4 = bsize >> 2; |
| 310 | |
| 311 | sbi->s_firstinodezone = 2; |
| 312 | |
| 313 | flavour_setup[sbi->s_type](sbi); |
| 314 | |
| 315 | sbi->s_truncate = 1; |
| 316 | sbi->s_ndatazones = sbi->s_nzones - sbi->s_firstdatazone; |
| 317 | sbi->s_inodes_per_block = bsize >> 6; |
| 318 | sbi->s_inodes_per_block_1 = (bsize >> 6)-1; |
| 319 | sbi->s_inodes_per_block_bits = n_bits-6; |
| 320 | sbi->s_ind_per_block = bsize_4; |
| 321 | sbi->s_ind_per_block_2 = bsize_4*bsize_4; |
| 322 | sbi->s_toobig_block = 10 + bsize_4 * (1 + bsize_4 * (1 + bsize_4)); |
| 323 | sbi->s_ind_per_block_bits = n_bits-2; |
| 324 | |
| 325 | sbi->s_ninodes = (sbi->s_firstdatazone - sbi->s_firstinodezone) |
| 326 | << sbi->s_inodes_per_block_bits; |
| 327 | |
| 328 | if (!silent) |
| 329 | printk("VFS: Found a %s FS (block size = %ld) on device %s\n", |
| 330 | found, sb->s_blocksize, sb->s_id); |
| 331 | |
| 332 | sb->s_magic = SYSV_MAGIC_BASE + sbi->s_type; |
| 333 | /* set up enough so that it can read an inode */ |
| 334 | sb->s_op = &sysv_sops; |
David Howells | b8e1343 | 2008-02-07 00:15:47 -0800 | [diff] [blame] | 335 | root_inode = sysv_iget(sb, SYSV_ROOT_INO); |
| 336 | if (IS_ERR(root_inode)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | printk("SysV FS: get root inode failed\n"); |
| 338 | return 0; |
| 339 | } |
| 340 | sb->s_root = d_alloc_root(root_inode); |
| 341 | if (!sb->s_root) { |
| 342 | iput(root_inode); |
| 343 | printk("SysV FS: get root dentry failed\n"); |
| 344 | return 0; |
| 345 | } |
| 346 | if (sbi->s_forced_ro) |
| 347 | sb->s_flags |= MS_RDONLY; |
| 348 | if (sbi->s_truncate) |
| 349 | sb->s_root->d_op = &sysv_dentry_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | return 1; |
| 351 | } |
| 352 | |
| 353 | static int sysv_fill_super(struct super_block *sb, void *data, int silent) |
| 354 | { |
| 355 | struct buffer_head *bh1, *bh = NULL; |
| 356 | struct sysv_sb_info *sbi; |
| 357 | unsigned long blocknr; |
| 358 | int size = 0, i; |
| 359 | |
Alexey Dobriyan | 2ecd05a | 2006-10-11 01:22:05 -0700 | [diff] [blame] | 360 | BUILD_BUG_ON(1024 != sizeof (struct xenix_super_block)); |
| 361 | BUILD_BUG_ON(512 != sizeof (struct sysv4_super_block)); |
| 362 | BUILD_BUG_ON(512 != sizeof (struct sysv2_super_block)); |
| 363 | BUILD_BUG_ON(500 != sizeof (struct coh_super_block)); |
| 364 | BUILD_BUG_ON(64 != sizeof (struct sysv_inode)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | |
Panagiotis Issaris | f8314dc | 2006-09-27 01:49:37 -0700 | [diff] [blame] | 366 | sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | if (!sbi) |
| 368 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | |
| 370 | sbi->s_sb = sb; |
| 371 | sbi->s_block_base = 0; |
| 372 | sb->s_fs_info = sbi; |
Tobias Klauser | e8c96f8 | 2006-03-24 03:15:34 -0800 | [diff] [blame] | 373 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | sb_set_blocksize(sb, BLOCK_SIZE); |
| 375 | |
Tobias Klauser | e8c96f8 | 2006-03-24 03:15:34 -0800 | [diff] [blame] | 376 | for (i = 0; i < ARRAY_SIZE(flavours) && !size; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | brelse(bh); |
| 378 | bh = sb_bread(sb, flavours[i].block); |
| 379 | if (!bh) |
| 380 | continue; |
| 381 | size = flavours[i].test(SYSV_SB(sb), bh); |
| 382 | } |
| 383 | |
| 384 | if (!size) |
| 385 | goto Eunknown; |
| 386 | |
| 387 | switch (size) { |
| 388 | case 1: |
| 389 | blocknr = bh->b_blocknr << 1; |
| 390 | brelse(bh); |
| 391 | sb_set_blocksize(sb, 512); |
| 392 | bh1 = sb_bread(sb, blocknr); |
| 393 | bh = sb_bread(sb, blocknr + 1); |
| 394 | break; |
| 395 | case 2: |
| 396 | bh1 = bh; |
| 397 | break; |
| 398 | case 3: |
| 399 | blocknr = bh->b_blocknr >> 1; |
| 400 | brelse(bh); |
| 401 | sb_set_blocksize(sb, 2048); |
| 402 | bh1 = bh = sb_bread(sb, blocknr); |
| 403 | break; |
| 404 | default: |
| 405 | goto Ebadsize; |
| 406 | } |
| 407 | |
| 408 | if (bh && bh1) { |
| 409 | sbi->s_bh1 = bh1; |
| 410 | sbi->s_bh2 = bh; |
| 411 | if (complete_read_super(sb, silent, size)) |
| 412 | return 0; |
| 413 | } |
| 414 | |
| 415 | brelse(bh1); |
| 416 | brelse(bh); |
| 417 | sb_set_blocksize(sb, BLOCK_SIZE); |
| 418 | printk("oldfs: cannot read superblock\n"); |
| 419 | failed: |
| 420 | kfree(sbi); |
| 421 | return -EINVAL; |
| 422 | |
| 423 | Eunknown: |
| 424 | brelse(bh); |
| 425 | if (!silent) |
| 426 | printk("VFS: unable to find oldfs superblock on device %s\n", |
| 427 | sb->s_id); |
| 428 | goto failed; |
| 429 | Ebadsize: |
| 430 | brelse(bh); |
| 431 | if (!silent) |
| 432 | printk("VFS: oldfs: unsupported block size (%dKb)\n", |
| 433 | 1<<(size-2)); |
| 434 | goto failed; |
| 435 | } |
| 436 | |
Lubomir Rintel | 6d0b545 | 2010-08-10 18:03:34 -0700 | [diff] [blame] | 437 | static int v7_sanity_check(struct super_block *sb, struct buffer_head *bh) |
| 438 | { |
| 439 | struct v7_super_block *v7sb; |
| 440 | struct sysv_inode *v7i; |
| 441 | struct buffer_head *bh2; |
| 442 | struct sysv_sb_info *sbi; |
| 443 | |
| 444 | sbi = sb->s_fs_info; |
| 445 | |
| 446 | /* plausibility check on superblock */ |
| 447 | v7sb = (struct v7_super_block *) bh->b_data; |
| 448 | if (fs16_to_cpu(sbi, v7sb->s_nfree) > V7_NICFREE || |
| 449 | fs16_to_cpu(sbi, v7sb->s_ninode) > V7_NICINOD || |
| 450 | fs32_to_cpu(sbi, v7sb->s_fsize) > V7_MAXSIZE) |
| 451 | return 0; |
| 452 | |
| 453 | /* plausibility check on root inode: it is a directory, |
| 454 | with a nonzero size that is a multiple of 16 */ |
| 455 | bh2 = sb_bread(sb, 2); |
| 456 | if (bh2 == NULL) |
| 457 | return 0; |
| 458 | |
| 459 | v7i = (struct sysv_inode *)(bh2->b_data + 64); |
| 460 | if ((fs16_to_cpu(sbi, v7i->i_mode) & ~0777) != S_IFDIR || |
| 461 | (fs32_to_cpu(sbi, v7i->i_size) == 0) || |
| 462 | (fs32_to_cpu(sbi, v7i->i_size) & 017) || |
| 463 | (fs32_to_cpu(sbi, v7i->i_size) > V7_NFILES * |
| 464 | sizeof(struct sysv_dir_entry))) { |
| 465 | brelse(bh2); |
| 466 | return 0; |
| 467 | } |
| 468 | |
| 469 | brelse(bh2); |
| 470 | return 1; |
| 471 | } |
| 472 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | static int v7_fill_super(struct super_block *sb, void *data, int silent) |
| 474 | { |
| 475 | struct sysv_sb_info *sbi; |
Lubomir Rintel | 6d0b545 | 2010-08-10 18:03:34 -0700 | [diff] [blame] | 476 | struct buffer_head *bh; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | |
| 478 | if (440 != sizeof (struct v7_super_block)) |
| 479 | panic("V7 FS: bad super-block size"); |
| 480 | if (64 != sizeof (struct sysv_inode)) |
| 481 | panic("sysv fs: bad i-node size"); |
| 482 | |
Panagiotis Issaris | f8314dc | 2006-09-27 01:49:37 -0700 | [diff] [blame] | 483 | sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | if (!sbi) |
| 485 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | |
| 487 | sbi->s_sb = sb; |
| 488 | sbi->s_block_base = 0; |
| 489 | sbi->s_type = FSTYPE_V7; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | sb->s_fs_info = sbi; |
| 491 | |
| 492 | sb_set_blocksize(sb, 512); |
| 493 | |
| 494 | if ((bh = sb_bread(sb, 1)) == NULL) { |
| 495 | if (!silent) |
| 496 | printk("VFS: unable to read V7 FS superblock on " |
| 497 | "device %s.\n", sb->s_id); |
| 498 | goto failed; |
| 499 | } |
| 500 | |
Lubomir Rintel | 6d0b545 | 2010-08-10 18:03:34 -0700 | [diff] [blame] | 501 | /* Try PDP-11 UNIX */ |
| 502 | sbi->s_bytesex = BYTESEX_PDP; |
| 503 | if (v7_sanity_check(sb, bh)) |
| 504 | goto detected; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | |
Lubomir Rintel | 6d0b545 | 2010-08-10 18:03:34 -0700 | [diff] [blame] | 506 | /* Try PC/IX, v7/x86 */ |
| 507 | sbi->s_bytesex = BYTESEX_LE; |
| 508 | if (v7_sanity_check(sb, bh)) |
| 509 | goto detected; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | |
Lubomir Rintel | 6d0b545 | 2010-08-10 18:03:34 -0700 | [diff] [blame] | 511 | goto failed; |
| 512 | |
| 513 | detected: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | sbi->s_bh1 = bh; |
| 515 | sbi->s_bh2 = bh; |
| 516 | if (complete_read_super(sb, silent, 1)) |
| 517 | return 0; |
| 518 | |
| 519 | failed: |
Lubomir Rintel | 6d0b545 | 2010-08-10 18:03:34 -0700 | [diff] [blame] | 520 | printk(KERN_ERR "VFS: could not find a valid V7 on %s.\n", |
| 521 | sb->s_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | brelse(bh); |
| 523 | kfree(sbi); |
| 524 | return -EINVAL; |
| 525 | } |
| 526 | |
| 527 | /* Every kernel module contains stuff like this. */ |
| 528 | |
Al Viro | 152a083 | 2010-07-25 00:46:55 +0400 | [diff] [blame] | 529 | static struct dentry *sysv_mount(struct file_system_type *fs_type, |
| 530 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | { |
Al Viro | 152a083 | 2010-07-25 00:46:55 +0400 | [diff] [blame] | 532 | return mount_bdev(fs_type, flags, dev_name, data, sysv_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | } |
| 534 | |
Al Viro | 152a083 | 2010-07-25 00:46:55 +0400 | [diff] [blame] | 535 | static struct dentry *v7_mount(struct file_system_type *fs_type, |
| 536 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | { |
Al Viro | 152a083 | 2010-07-25 00:46:55 +0400 | [diff] [blame] | 538 | return mount_bdev(fs_type, flags, dev_name, data, v7_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | } |
| 540 | |
| 541 | static struct file_system_type sysv_fs_type = { |
| 542 | .owner = THIS_MODULE, |
| 543 | .name = "sysv", |
Al Viro | 152a083 | 2010-07-25 00:46:55 +0400 | [diff] [blame] | 544 | .mount = sysv_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | .kill_sb = kill_block_super, |
| 546 | .fs_flags = FS_REQUIRES_DEV, |
| 547 | }; |
| 548 | |
| 549 | static struct file_system_type v7_fs_type = { |
| 550 | .owner = THIS_MODULE, |
| 551 | .name = "v7", |
Al Viro | 152a083 | 2010-07-25 00:46:55 +0400 | [diff] [blame] | 552 | .mount = v7_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | .kill_sb = kill_block_super, |
| 554 | .fs_flags = FS_REQUIRES_DEV, |
| 555 | }; |
| 556 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | static int __init init_sysv_fs(void) |
| 558 | { |
| 559 | int error; |
| 560 | |
| 561 | error = sysv_init_icache(); |
| 562 | if (error) |
| 563 | goto out; |
| 564 | error = register_filesystem(&sysv_fs_type); |
| 565 | if (error) |
| 566 | goto destroy_icache; |
| 567 | error = register_filesystem(&v7_fs_type); |
| 568 | if (error) |
| 569 | goto unregister; |
| 570 | return 0; |
| 571 | |
| 572 | unregister: |
| 573 | unregister_filesystem(&sysv_fs_type); |
| 574 | destroy_icache: |
| 575 | sysv_destroy_icache(); |
| 576 | out: |
| 577 | return error; |
| 578 | } |
| 579 | |
| 580 | static void __exit exit_sysv_fs(void) |
| 581 | { |
| 582 | unregister_filesystem(&sysv_fs_type); |
| 583 | unregister_filesystem(&v7_fs_type); |
| 584 | sysv_destroy_icache(); |
| 585 | } |
| 586 | |
| 587 | module_init(init_sysv_fs) |
| 588 | module_exit(exit_sysv_fs) |
Lubomir Rintel | b76212d | 2010-07-19 19:16:40 +0200 | [diff] [blame] | 589 | MODULE_ALIAS("v7"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | MODULE_LICENSE("GPL"); |