1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/fs/adfs/super.c
5 * Copyright (C) 1997-1999 Russell King
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/buffer_head.h>
10 #include <linux/parser.h>
11 #include <linux/mount.h>
12 #include <linux/seq_file.h>
13 #include <linux/slab.h>
14 #include <linux/statfs.h>
15 #include <linux/user_namespace.h>
18 #include "dir_fplus.h"
20 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
21 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
23 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
29 vsnprintf(error_buf, sizeof(error_buf), fmt, args);
32 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
33 sb->s_id, function ? ": " : "",
34 function ? function : "", error_buf);
37 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
41 /* sector size must be 256, 512 or 1024 bytes */
42 if (dr->log2secsize != 8 &&
43 dr->log2secsize != 9 &&
44 dr->log2secsize != 10)
47 /* idlen must be at least log2secsize + 3 */
48 if (dr->idlen < dr->log2secsize + 3)
51 /* we cannot have such a large disc that we
52 * are unable to represent sector offsets in
53 * 32 bits. This works out at 2.0 TB.
55 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
58 /* idlen must be no greater than 19 v2 [1.0] */
62 /* reserved bytes should be zero */
63 for (i = 0; i < sizeof(dr->unused52); i++)
64 if (dr->unused52[i] != 0)
70 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
72 unsigned int v0, v1, v2, v3;
75 v0 = v1 = v2 = v3 = 0;
76 for (i = sb->s_blocksize - 4; i; i -= 4) {
77 v0 += map[i] + (v3 >> 8);
79 v1 += map[i + 1] + (v0 >> 8);
81 v2 += map[i + 2] + (v1 >> 8);
83 v3 += map[i + 3] + (v2 >> 8);
87 v1 += map[1] + (v0 >> 8);
88 v2 += map[2] + (v1 >> 8);
89 v3 += map[3] + (v2 >> 8);
91 return v0 ^ v1 ^ v2 ^ v3;
94 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
96 unsigned char crosscheck = 0, zonecheck = 1;
99 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
102 map = dm[i].dm_bh->b_data;
104 if (adfs_calczonecheck(sb, map) != map[0]) {
105 adfs_error(sb, "zone %d fails zonecheck", i);
108 crosscheck ^= map[3];
110 if (crosscheck != 0xff)
111 adfs_error(sb, "crosscheck != 0xff");
112 return crosscheck == 0xff && zonecheck;
115 static void adfs_put_super(struct super_block *sb)
118 struct adfs_sb_info *asb = ADFS_SB(sb);
120 for (i = 0; i < asb->s_map_size; i++)
121 brelse(asb->s_map[i].dm_bh);
126 static int adfs_show_options(struct seq_file *seq, struct dentry *root)
128 struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
130 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
131 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
132 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
133 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
134 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
135 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
136 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
137 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
138 if (asb->s_ftsuffix != 0)
139 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
144 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};
146 static const match_table_t tokens = {
149 {Opt_ownmask, "ownmask=%o"},
150 {Opt_othmask, "othmask=%o"},
151 {Opt_ftsuffix, "ftsuffix=%u"},
155 static int parse_options(struct super_block *sb, char *options)
158 struct adfs_sb_info *asb = ADFS_SB(sb);
164 while ((p = strsep(&options, ",")) != NULL) {
165 substring_t args[MAX_OPT_ARGS];
170 token = match_token(p, tokens, args);
173 if (match_int(args, &option))
175 asb->s_uid = make_kuid(current_user_ns(), option);
176 if (!uid_valid(asb->s_uid))
180 if (match_int(args, &option))
182 asb->s_gid = make_kgid(current_user_ns(), option);
183 if (!gid_valid(asb->s_gid))
187 if (match_octal(args, &option))
189 asb->s_owner_mask = option;
192 if (match_octal(args, &option))
194 asb->s_other_mask = option;
197 if (match_int(args, &option))
199 asb->s_ftsuffix = option;
202 printk("ADFS-fs: unrecognised mount option \"%s\" "
203 "or missing value\n", p);
210 static int adfs_remount(struct super_block *sb, int *flags, char *data)
213 *flags |= SB_NODIRATIME;
214 return parse_options(sb, data);
217 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
219 struct super_block *sb = dentry->d_sb;
220 struct adfs_sb_info *sbi = ADFS_SB(sb);
221 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
223 buf->f_type = ADFS_SUPER_MAGIC;
224 buf->f_namelen = sbi->s_namelen;
225 buf->f_bsize = sb->s_blocksize;
226 buf->f_blocks = sbi->s_size;
227 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size;
229 buf->f_bfree = adfs_map_free(sb);
230 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
231 buf->f_fsid.val[0] = (u32)id;
232 buf->f_fsid.val[1] = (u32)(id >> 32);
237 static struct kmem_cache *adfs_inode_cachep;
239 static struct inode *adfs_alloc_inode(struct super_block *sb)
241 struct adfs_inode_info *ei;
242 ei = kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
245 return &ei->vfs_inode;
248 static void adfs_free_inode(struct inode *inode)
250 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
253 static void init_once(void *foo)
255 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
257 inode_init_once(&ei->vfs_inode);
260 static int __init init_inodecache(void)
262 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
263 sizeof(struct adfs_inode_info),
264 0, (SLAB_RECLAIM_ACCOUNT|
265 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
267 if (adfs_inode_cachep == NULL)
272 static void destroy_inodecache(void)
275 * Make sure all delayed rcu free inodes are flushed before we
279 kmem_cache_destroy(adfs_inode_cachep);
282 static const struct super_operations adfs_sops = {
283 .alloc_inode = adfs_alloc_inode,
284 .free_inode = adfs_free_inode,
285 .drop_inode = generic_delete_inode,
286 .write_inode = adfs_write_inode,
287 .put_super = adfs_put_super,
288 .statfs = adfs_statfs,
289 .remount_fs = adfs_remount,
290 .show_options = adfs_show_options,
293 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
295 struct adfs_discmap *dm;
296 unsigned int map_addr, zone_size, nzones;
298 struct adfs_sb_info *asb = ADFS_SB(sb);
300 nzones = asb->s_map_size;
301 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
302 map_addr = (nzones >> 1) * zone_size -
303 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
304 map_addr = signed_asl(map_addr, asb->s_map2blk);
306 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
308 dm = kmalloc_array(nzones, sizeof(*dm), GFP_KERNEL);
310 adfs_error(sb, "not enough memory");
311 return ERR_PTR(-ENOMEM);
314 for (zone = 0; zone < nzones; zone++, map_addr++) {
315 dm[zone].dm_startbit = 0;
316 dm[zone].dm_endbit = zone_size;
317 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
318 dm[zone].dm_bh = sb_bread(sb, map_addr);
320 if (!dm[zone].dm_bh) {
321 adfs_error(sb, "unable to read map");
326 /* adjust the limits for the first and last map zones */
328 dm[0].dm_startblk = 0;
329 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
330 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
331 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
332 (ADFS_DR_SIZE_BITS - i * zone_size);
334 if (adfs_checkmap(sb, dm))
337 adfs_error(sb, "map corrupted");
341 brelse(dm[zone].dm_bh);
344 return ERR_PTR(-EIO);
347 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
349 unsigned long discsize;
351 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
352 discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
357 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
359 struct adfs_discrecord *dr;
360 struct buffer_head *bh;
361 struct object_info root_obj;
362 unsigned char *b_data;
363 struct adfs_sb_info *asb;
367 sb->s_flags |= SB_NODIRATIME;
369 asb = kzalloc(sizeof(*asb), GFP_KERNEL);
374 /* set default options */
375 asb->s_uid = GLOBAL_ROOT_UID;
376 asb->s_gid = GLOBAL_ROOT_GID;
377 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
378 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
381 if (parse_options(sb, data))
384 sb_set_blocksize(sb, BLOCK_SIZE);
385 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
386 adfs_error(sb, "unable to read superblock");
391 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
393 if (adfs_checkbblk(b_data)) {
395 printk("VFS: Can't find an adfs filesystem on dev "
401 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
404 * Do some sanity checks on the ADFS disc record
406 if (adfs_checkdiscrecord(dr)) {
408 printk("VPS: Can't find an adfs filesystem on dev "
415 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
416 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
418 adfs_error(sb, "couldn't read superblock on "
423 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
424 if (adfs_checkbblk(b_data)) {
425 adfs_error(sb, "disc record mismatch, very weird!");
429 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
432 printk(KERN_ERR "VFS: Unsupported blocksize on dev "
439 * blocksize on this device should now be set to the ADFS log2secsize
442 sb->s_magic = ADFS_SUPER_MAGIC;
443 asb->s_idlen = dr->idlen;
444 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
445 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
446 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits);
447 asb->s_version = dr->format_version;
448 asb->s_log2sharesize = dr->log2sharesize;
450 asb->s_map = adfs_read_map(sb, dr);
451 if (IS_ERR(asb->s_map)) {
452 ret = PTR_ERR(asb->s_map);
459 * set up enough so that we can read an inode
461 sb->s_op = &adfs_sops;
463 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
465 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
466 root_obj.name_len = 0;
467 /* Set root object date as 01 Jan 1987 00:00:00 */
468 root_obj.loadaddr = 0xfff0003f;
469 root_obj.execaddr = 0xec22c000;
470 root_obj.size = ADFS_NEWDIR_SIZE;
471 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
472 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
473 root_obj.filetype = -1;
476 * If this is a F+ disk with variable length directories,
477 * get the root_size from the disc record.
479 if (asb->s_version) {
480 root_obj.size = le32_to_cpu(dr->root_size);
481 asb->s_dir = &adfs_fplus_dir_ops;
482 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
484 asb->s_dir = &adfs_f_dir_ops;
485 asb->s_namelen = ADFS_F_NAME_LEN;
488 * ,xyz hex filetype suffix may be added by driver
489 * to files that have valid RISC OS filetype
494 sb->s_d_op = &adfs_dentry_operations;
495 root = adfs_iget(sb, &root_obj);
496 sb->s_root = d_make_root(root);
499 for (i = 0; i < asb->s_map_size; i++)
500 brelse(asb->s_map[i].dm_bh);
502 adfs_error(sb, "get root inode failed\n");
511 sb->s_fs_info = NULL;
516 static struct dentry *adfs_mount(struct file_system_type *fs_type,
517 int flags, const char *dev_name, void *data)
519 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super);
522 static struct file_system_type adfs_fs_type = {
523 .owner = THIS_MODULE,
526 .kill_sb = kill_block_super,
527 .fs_flags = FS_REQUIRES_DEV,
529 MODULE_ALIAS_FS("adfs");
531 static int __init init_adfs_fs(void)
533 int err = init_inodecache();
536 err = register_filesystem(&adfs_fs_type);
541 destroy_inodecache();
546 static void __exit exit_adfs_fs(void)
548 unregister_filesystem(&adfs_fs_type);
549 destroy_inodecache();
552 module_init(init_adfs_fs)
553 module_exit(exit_adfs_fs)
554 MODULE_LICENSE("GPL");