2 * linux/fs/adfs/super.c
4 * Copyright (C) 1997-1999 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/errno.h>
13 #include <linux/adfs_fs.h>
14 #include <linux/slab.h>
15 #include <linux/time.h>
16 #include <linux/stat.h>
17 #include <linux/string.h>
18 #include <linux/init.h>
19 #include <linux/buffer_head.h>
20 #include <linux/vfs.h>
21 #include <linux/parser.h>
22 #include <linux/bitops.h>
24 #include <asm/uaccess.h>
25 #include <asm/system.h>
31 #include "dir_fplus.h"
33 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
39 vsprintf(error_buf, fmt, args);
42 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
43 sb->s_id, function ? ": " : "",
44 function ? function : "", error_buf);
47 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
51 /* sector size must be 256, 512 or 1024 bytes */
52 if (dr->log2secsize != 8 &&
53 dr->log2secsize != 9 &&
54 dr->log2secsize != 10)
57 /* idlen must be at least log2secsize + 3 */
58 if (dr->idlen < dr->log2secsize + 3)
61 /* we cannot have such a large disc that we
62 * are unable to represent sector offsets in
63 * 32 bits. This works out at 2.0 TB.
65 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
68 /* idlen must be no greater than 19 v2 [1.0] */
72 /* reserved bytes should be zero */
73 for (i = 0; i < sizeof(dr->unused52); i++)
74 if (dr->unused52[i] != 0)
80 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
82 unsigned int v0, v1, v2, v3;
85 v0 = v1 = v2 = v3 = 0;
86 for (i = sb->s_blocksize - 4; i; i -= 4) {
87 v0 += map[i] + (v3 >> 8);
89 v1 += map[i + 1] + (v0 >> 8);
91 v2 += map[i + 2] + (v1 >> 8);
93 v3 += map[i + 3] + (v2 >> 8);
97 v1 += map[1] + (v0 >> 8);
98 v2 += map[2] + (v1 >> 8);
99 v3 += map[3] + (v2 >> 8);
101 return v0 ^ v1 ^ v2 ^ v3;
104 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
106 unsigned char crosscheck = 0, zonecheck = 1;
109 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
112 map = dm[i].dm_bh->b_data;
114 if (adfs_calczonecheck(sb, map) != map[0]) {
115 adfs_error(sb, "zone %d fails zonecheck", i);
118 crosscheck ^= map[3];
120 if (crosscheck != 0xff)
121 adfs_error(sb, "crosscheck != 0xff");
122 return crosscheck == 0xff && zonecheck;
125 static void adfs_put_super(struct super_block *sb)
128 struct adfs_sb_info *asb = ADFS_SB(sb);
130 for (i = 0; i < asb->s_map_size; i++)
131 brelse(asb->s_map[i].dm_bh);
134 sb->s_fs_info = NULL;
137 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err};
139 static match_table_t tokens = {
142 {Opt_ownmask, "ownmask=%o"},
143 {Opt_othmask, "othmask=%o"},
147 static int parse_options(struct super_block *sb, char *options)
150 struct adfs_sb_info *asb = ADFS_SB(sb);
156 while ((p = strsep(&options, ",")) != NULL) {
157 substring_t args[MAX_OPT_ARGS];
162 token = match_token(p, tokens, args);
165 if (match_int(args, &option))
170 if (match_int(args, &option))
175 if (match_octal(args, &option))
177 asb->s_owner_mask = option;
180 if (match_octal(args, &option))
182 asb->s_other_mask = option;
185 printk("ADFS-fs: unrecognised mount option \"%s\" "
186 "or missing value\n", p);
193 static int adfs_remount(struct super_block *sb, int *flags, char *data)
195 *flags |= MS_NODIRATIME;
196 return parse_options(sb, data);
199 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
201 struct adfs_sb_info *asb = ADFS_SB(dentry->d_sb);
203 buf->f_type = ADFS_SUPER_MAGIC;
204 buf->f_namelen = asb->s_namelen;
205 buf->f_bsize = dentry->d_sb->s_blocksize;
206 buf->f_blocks = asb->s_size;
207 buf->f_files = asb->s_ids_per_zone * asb->s_map_size;
209 buf->f_bfree = adfs_map_free(dentry->d_sb);
210 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
215 static kmem_cache_t *adfs_inode_cachep;
217 static struct inode *adfs_alloc_inode(struct super_block *sb)
219 struct adfs_inode_info *ei;
220 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, SLAB_KERNEL);
223 return &ei->vfs_inode;
226 static void adfs_destroy_inode(struct inode *inode)
228 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
231 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
233 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
235 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
236 SLAB_CTOR_CONSTRUCTOR)
237 inode_init_once(&ei->vfs_inode);
240 static int init_inodecache(void)
242 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
243 sizeof(struct adfs_inode_info),
244 0, (SLAB_RECLAIM_ACCOUNT|
247 if (adfs_inode_cachep == NULL)
252 static void destroy_inodecache(void)
254 if (kmem_cache_destroy(adfs_inode_cachep))
255 printk(KERN_INFO "adfs_inode_cache: not all structures were freed\n");
258 static struct super_operations adfs_sops = {
259 .alloc_inode = adfs_alloc_inode,
260 .destroy_inode = adfs_destroy_inode,
261 .write_inode = adfs_write_inode,
262 .put_super = adfs_put_super,
263 .statfs = adfs_statfs,
264 .remount_fs = adfs_remount,
267 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
269 struct adfs_discmap *dm;
270 unsigned int map_addr, zone_size, nzones;
272 struct adfs_sb_info *asb = ADFS_SB(sb);
274 nzones = asb->s_map_size;
275 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
276 map_addr = (nzones >> 1) * zone_size -
277 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
278 map_addr = signed_asl(map_addr, asb->s_map2blk);
280 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
282 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
284 adfs_error(sb, "not enough memory");
288 for (zone = 0; zone < nzones; zone++, map_addr++) {
289 dm[zone].dm_startbit = 0;
290 dm[zone].dm_endbit = zone_size;
291 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
292 dm[zone].dm_bh = sb_bread(sb, map_addr);
294 if (!dm[zone].dm_bh) {
295 adfs_error(sb, "unable to read map");
300 /* adjust the limits for the first and last map zones */
302 dm[0].dm_startblk = 0;
303 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
304 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
305 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
306 (ADFS_DR_SIZE_BITS - i * zone_size);
308 if (adfs_checkmap(sb, dm))
311 adfs_error(sb, "map corrupted");
315 brelse(dm[zone].dm_bh);
321 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
323 unsigned long discsize;
325 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
326 discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
331 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
333 struct adfs_discrecord *dr;
334 struct buffer_head *bh;
335 struct object_info root_obj;
336 unsigned char *b_data;
337 struct adfs_sb_info *asb;
340 sb->s_flags |= MS_NODIRATIME;
342 asb = kmalloc(sizeof(*asb), GFP_KERNEL);
346 memset(asb, 0, sizeof(*asb));
348 /* set default options */
351 asb->s_owner_mask = S_IRWXU;
352 asb->s_other_mask = S_IRWXG | S_IRWXO;
354 if (parse_options(sb, data))
357 sb_set_blocksize(sb, BLOCK_SIZE);
358 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
359 adfs_error(sb, "unable to read superblock");
363 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
365 if (adfs_checkbblk(b_data)) {
367 printk("VFS: Can't find an adfs filesystem on dev "
372 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
375 * Do some sanity checks on the ADFS disc record
377 if (adfs_checkdiscrecord(dr)) {
379 printk("VPS: Can't find an adfs filesystem on dev "
385 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
386 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
388 adfs_error(sb, "couldn't read superblock on "
392 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
393 if (adfs_checkbblk(b_data)) {
394 adfs_error(sb, "disc record mismatch, very weird!");
397 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
400 printk(KERN_ERR "VFS: Unsupported blocksize on dev "
406 * blocksize on this device should now be set to the ADFS log2secsize
409 sb->s_magic = ADFS_SUPER_MAGIC;
410 asb->s_idlen = dr->idlen;
411 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
412 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
413 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits);
414 asb->s_version = dr->format_version;
415 asb->s_log2sharesize = dr->log2sharesize;
417 asb->s_map = adfs_read_map(sb, dr);
424 * set up enough so that we can read an inode
426 sb->s_op = &adfs_sops;
428 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
430 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
431 root_obj.name_len = 0;
432 root_obj.loadaddr = 0;
433 root_obj.execaddr = 0;
434 root_obj.size = ADFS_NEWDIR_SIZE;
435 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
436 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
439 * If this is a F+ disk with variable length directories,
440 * get the root_size from the disc record.
442 if (asb->s_version) {
443 root_obj.size = le32_to_cpu(dr->root_size);
444 asb->s_dir = &adfs_fplus_dir_ops;
445 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
447 asb->s_dir = &adfs_f_dir_ops;
448 asb->s_namelen = ADFS_F_NAME_LEN;
451 root = adfs_iget(sb, &root_obj);
452 sb->s_root = d_alloc_root(root);
456 for (i = 0; i < asb->s_map_size; i++)
457 brelse(asb->s_map[i].dm_bh);
459 adfs_error(sb, "get root inode failed\n");
462 sb->s_root->d_op = &adfs_dentry_operations;
468 sb->s_fs_info = NULL;
473 static int adfs_get_sb(struct file_system_type *fs_type,
474 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
476 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super,
480 static struct file_system_type adfs_fs_type = {
481 .owner = THIS_MODULE,
483 .get_sb = adfs_get_sb,
484 .kill_sb = kill_block_super,
485 .fs_flags = FS_REQUIRES_DEV,
488 static int __init init_adfs_fs(void)
490 int err = init_inodecache();
493 err = register_filesystem(&adfs_fs_type);
498 destroy_inodecache();
503 static void __exit exit_adfs_fs(void)
505 unregister_filesystem(&adfs_fs_type);
506 destroy_inodecache();
509 module_init(init_adfs_fs)
510 module_exit(exit_adfs_fs)