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/init.h>
12 #include <linux/parser.h>
13 #include <linux/mount.h>
14 #include <linux/seq_file.h>
15 #include <linux/slab.h>
16 #include <linux/statfs.h>
17 #include <linux/user_namespace.h>
20 #include "dir_fplus.h"
22 #define ADFS_SB_FLAGS SB_NOATIME
24 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
25 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
27 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
36 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n",
37 sb->s_id, function ? ": " : "",
38 function ? function : "", &vaf);
43 void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)
51 printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf);
55 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
59 /* sector size must be 256, 512 or 1024 bytes */
60 if (dr->log2secsize != 8 &&
61 dr->log2secsize != 9 &&
62 dr->log2secsize != 10)
65 /* idlen must be at least log2secsize + 3 */
66 if (dr->idlen < dr->log2secsize + 3)
69 /* we cannot have such a large disc that we
70 * are unable to represent sector offsets in
71 * 32 bits. This works out at 2.0 TB.
73 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
76 /* idlen must be no greater than 19 v2 [1.0] */
80 /* reserved bytes should be zero */
81 for (i = 0; i < sizeof(dr->unused52); i++)
82 if (dr->unused52[i] != 0)
88 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
90 unsigned int v0, v1, v2, v3;
93 v0 = v1 = v2 = v3 = 0;
94 for (i = sb->s_blocksize - 4; i; i -= 4) {
95 v0 += map[i] + (v3 >> 8);
97 v1 += map[i + 1] + (v0 >> 8);
99 v2 += map[i + 2] + (v1 >> 8);
101 v3 += map[i + 3] + (v2 >> 8);
105 v1 += map[1] + (v0 >> 8);
106 v2 += map[2] + (v1 >> 8);
107 v3 += map[3] + (v2 >> 8);
109 return v0 ^ v1 ^ v2 ^ v3;
112 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
114 unsigned char crosscheck = 0, zonecheck = 1;
117 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
120 map = dm[i].dm_bh->b_data;
122 if (adfs_calczonecheck(sb, map) != map[0]) {
123 adfs_error(sb, "zone %d fails zonecheck", i);
126 crosscheck ^= map[3];
128 if (crosscheck != 0xff)
129 adfs_error(sb, "crosscheck != 0xff");
130 return crosscheck == 0xff && zonecheck;
133 static void adfs_put_super(struct super_block *sb)
136 struct adfs_sb_info *asb = ADFS_SB(sb);
138 for (i = 0; i < asb->s_map_size; i++)
139 brelse(asb->s_map[i].dm_bh);
144 static int adfs_show_options(struct seq_file *seq, struct dentry *root)
146 struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
148 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
149 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
150 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
151 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
152 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
153 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
154 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
155 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
156 if (asb->s_ftsuffix != 0)
157 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
162 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};
164 static const match_table_t tokens = {
167 {Opt_ownmask, "ownmask=%o"},
168 {Opt_othmask, "othmask=%o"},
169 {Opt_ftsuffix, "ftsuffix=%u"},
173 static int parse_options(struct super_block *sb, char *options)
176 struct adfs_sb_info *asb = ADFS_SB(sb);
182 while ((p = strsep(&options, ",")) != NULL) {
183 substring_t args[MAX_OPT_ARGS];
188 token = match_token(p, tokens, args);
191 if (match_int(args, &option))
193 asb->s_uid = make_kuid(current_user_ns(), option);
194 if (!uid_valid(asb->s_uid))
198 if (match_int(args, &option))
200 asb->s_gid = make_kgid(current_user_ns(), option);
201 if (!gid_valid(asb->s_gid))
205 if (match_octal(args, &option))
207 asb->s_owner_mask = option;
210 if (match_octal(args, &option))
212 asb->s_other_mask = option;
215 if (match_int(args, &option))
217 asb->s_ftsuffix = option;
220 adfs_msg(sb, KERN_ERR,
221 "unrecognised mount option \"%s\" or missing value",
229 static int adfs_remount(struct super_block *sb, int *flags, char *data)
232 *flags |= ADFS_SB_FLAGS;
233 return parse_options(sb, data);
236 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
238 struct super_block *sb = dentry->d_sb;
239 struct adfs_sb_info *sbi = ADFS_SB(sb);
240 struct adfs_discrecord *dr = adfs_map_discrecord(sbi->s_map);
241 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
243 buf->f_type = ADFS_SUPER_MAGIC;
244 buf->f_namelen = sbi->s_namelen;
245 buf->f_bsize = sb->s_blocksize;
246 buf->f_blocks = adfs_disc_size(dr) >> sb->s_blocksize_bits;
247 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size;
249 buf->f_bfree = adfs_map_free(sb);
250 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
251 buf->f_fsid.val[0] = (u32)id;
252 buf->f_fsid.val[1] = (u32)(id >> 32);
257 static struct kmem_cache *adfs_inode_cachep;
259 static struct inode *adfs_alloc_inode(struct super_block *sb)
261 struct adfs_inode_info *ei;
262 ei = kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
265 return &ei->vfs_inode;
268 static void adfs_free_inode(struct inode *inode)
270 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
273 static void init_once(void *foo)
275 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
277 inode_init_once(&ei->vfs_inode);
280 static int __init init_inodecache(void)
282 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
283 sizeof(struct adfs_inode_info),
284 0, (SLAB_RECLAIM_ACCOUNT|
285 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
287 if (adfs_inode_cachep == NULL)
292 static void destroy_inodecache(void)
295 * Make sure all delayed rcu free inodes are flushed before we
299 kmem_cache_destroy(adfs_inode_cachep);
302 static const struct super_operations adfs_sops = {
303 .alloc_inode = adfs_alloc_inode,
304 .free_inode = adfs_free_inode,
305 .drop_inode = generic_delete_inode,
306 .write_inode = adfs_write_inode,
307 .put_super = adfs_put_super,
308 .statfs = adfs_statfs,
309 .remount_fs = adfs_remount,
310 .show_options = adfs_show_options,
313 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
315 struct adfs_discmap *dm;
316 unsigned int map_addr, zone_size, nzones;
318 struct adfs_sb_info *asb = ADFS_SB(sb);
320 nzones = asb->s_map_size;
321 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
322 map_addr = (nzones >> 1) * zone_size -
323 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
324 map_addr = signed_asl(map_addr, asb->s_map2blk);
326 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
328 dm = kmalloc_array(nzones, sizeof(*dm), GFP_KERNEL);
330 adfs_error(sb, "not enough memory");
331 return ERR_PTR(-ENOMEM);
334 for (zone = 0; zone < nzones; zone++, map_addr++) {
335 dm[zone].dm_startbit = 0;
336 dm[zone].dm_endbit = zone_size;
337 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
338 dm[zone].dm_bh = sb_bread(sb, map_addr);
340 if (!dm[zone].dm_bh) {
341 adfs_error(sb, "unable to read map");
346 /* adjust the limits for the first and last map zones */
348 dm[0].dm_startblk = 0;
349 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
350 dm[i].dm_endbit = (adfs_disc_size(dr) >> dr->log2bpmb) +
351 (ADFS_DR_SIZE_BITS - i * zone_size);
353 if (adfs_checkmap(sb, dm))
356 adfs_error(sb, "map corrupted");
360 brelse(dm[zone].dm_bh);
363 return ERR_PTR(-EIO);
366 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
368 struct adfs_discrecord *dr;
369 struct buffer_head *bh;
370 struct object_info root_obj;
371 unsigned char *b_data;
372 struct adfs_sb_info *asb;
376 sb->s_flags |= ADFS_SB_FLAGS;
378 asb = kzalloc(sizeof(*asb), GFP_KERNEL);
383 /* set default options */
384 asb->s_uid = GLOBAL_ROOT_UID;
385 asb->s_gid = GLOBAL_ROOT_GID;
386 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
387 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
390 if (parse_options(sb, data))
393 sb_set_blocksize(sb, BLOCK_SIZE);
394 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
395 adfs_msg(sb, KERN_ERR, "error: unable to read superblock");
400 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
402 if (adfs_checkbblk(b_data)) {
407 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
410 * Do some sanity checks on the ADFS disc record
412 if (adfs_checkdiscrecord(dr)) {
418 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
419 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
421 adfs_msg(sb, KERN_ERR,
422 "error: couldn't read superblock on 2nd try.");
426 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
427 if (adfs_checkbblk(b_data)) {
428 adfs_msg(sb, KERN_ERR,
429 "error: disc record mismatch, very weird!");
433 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
436 adfs_msg(sb, KERN_ERR,
437 "error: unsupported blocksize");
443 * blocksize on this device should now be set to the ADFS log2secsize
446 sb->s_magic = ADFS_SUPER_MAGIC;
447 asb->s_idlen = dr->idlen;
448 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
449 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
450 asb->s_log2sharesize = dr->log2sharesize;
452 asb->s_map = adfs_read_map(sb, dr);
453 if (IS_ERR(asb->s_map)) {
454 ret = PTR_ERR(asb->s_map);
461 * set up enough so that we can read an inode
463 sb->s_op = &adfs_sops;
465 dr = adfs_map_discrecord(asb->s_map);
467 root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root);
468 root_obj.name_len = 0;
469 /* Set root object date as 01 Jan 1987 00:00:00 */
470 root_obj.loadaddr = 0xfff0003f;
471 root_obj.execaddr = 0xec22c000;
472 root_obj.size = ADFS_NEWDIR_SIZE;
473 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
474 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
475 root_obj.filetype = -1;
478 * If this is a F+ disk with variable length directories,
479 * get the root_size from the disc record.
481 if (dr->format_version) {
482 root_obj.size = le32_to_cpu(dr->root_size);
483 asb->s_dir = &adfs_fplus_dir_ops;
484 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
486 asb->s_dir = &adfs_f_dir_ops;
487 asb->s_namelen = ADFS_F_NAME_LEN;
490 * ,xyz hex filetype suffix may be added by driver
491 * to files that have valid RISC OS filetype
496 sb->s_d_op = &adfs_dentry_operations;
497 root = adfs_iget(sb, &root_obj);
498 sb->s_root = d_make_root(root);
501 for (i = 0; i < asb->s_map_size; i++)
502 brelse(asb->s_map[i].dm_bh);
504 adfs_error(sb, "get root inode failed\n");
512 adfs_msg(sb, KERN_ERR,
513 "error: can't find an ADFS filesystem on dev %s.",
518 sb->s_fs_info = NULL;
523 static struct dentry *adfs_mount(struct file_system_type *fs_type,
524 int flags, const char *dev_name, void *data)
526 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super);
529 static struct file_system_type adfs_fs_type = {
530 .owner = THIS_MODULE,
533 .kill_sb = kill_block_super,
534 .fs_flags = FS_REQUIRES_DEV,
536 MODULE_ALIAS_FS("adfs");
538 static int __init init_adfs_fs(void)
540 int err = init_inodecache();
543 err = register_filesystem(&adfs_fs_type);
548 destroy_inodecache();
553 static void __exit exit_adfs_fs(void)
555 unregister_filesystem(&adfs_fs_type);
556 destroy_inodecache();
559 module_init(init_adfs_fs)
560 module_exit(exit_adfs_fs)
561 MODULE_LICENSE("GPL");