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/buffer_head.h>
13 #include <linux/parser.h>
14 #include <linux/mount.h>
15 #include <linux/seq_file.h>
16 #include <linux/slab.h>
17 #include <linux/statfs.h>
18 #include <linux/user_namespace.h>
21 #include "dir_fplus.h"
23 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
24 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
26 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
32 vsnprintf(error_buf, sizeof(error_buf), fmt, args);
35 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
36 sb->s_id, function ? ": " : "",
37 function ? function : "", error_buf);
40 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
44 /* sector size must be 256, 512 or 1024 bytes */
45 if (dr->log2secsize != 8 &&
46 dr->log2secsize != 9 &&
47 dr->log2secsize != 10)
50 /* idlen must be at least log2secsize + 3 */
51 if (dr->idlen < dr->log2secsize + 3)
54 /* we cannot have such a large disc that we
55 * are unable to represent sector offsets in
56 * 32 bits. This works out at 2.0 TB.
58 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
61 /* idlen must be no greater than 19 v2 [1.0] */
65 /* reserved bytes should be zero */
66 for (i = 0; i < sizeof(dr->unused52); i++)
67 if (dr->unused52[i] != 0)
73 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
75 unsigned int v0, v1, v2, v3;
78 v0 = v1 = v2 = v3 = 0;
79 for (i = sb->s_blocksize - 4; i; i -= 4) {
80 v0 += map[i] + (v3 >> 8);
82 v1 += map[i + 1] + (v0 >> 8);
84 v2 += map[i + 2] + (v1 >> 8);
86 v3 += map[i + 3] + (v2 >> 8);
90 v1 += map[1] + (v0 >> 8);
91 v2 += map[2] + (v1 >> 8);
92 v3 += map[3] + (v2 >> 8);
94 return v0 ^ v1 ^ v2 ^ v3;
97 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
99 unsigned char crosscheck = 0, zonecheck = 1;
102 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
105 map = dm[i].dm_bh->b_data;
107 if (adfs_calczonecheck(sb, map) != map[0]) {
108 adfs_error(sb, "zone %d fails zonecheck", i);
111 crosscheck ^= map[3];
113 if (crosscheck != 0xff)
114 adfs_error(sb, "crosscheck != 0xff");
115 return crosscheck == 0xff && zonecheck;
118 static void adfs_put_super(struct super_block *sb)
121 struct adfs_sb_info *asb = ADFS_SB(sb);
123 for (i = 0; i < asb->s_map_size; i++)
124 brelse(asb->s_map[i].dm_bh);
129 static int adfs_show_options(struct seq_file *seq, struct dentry *root)
131 struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
133 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
134 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
135 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
136 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
137 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
138 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
139 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
140 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
141 if (asb->s_ftsuffix != 0)
142 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
147 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};
149 static const match_table_t tokens = {
152 {Opt_ownmask, "ownmask=%o"},
153 {Opt_othmask, "othmask=%o"},
154 {Opt_ftsuffix, "ftsuffix=%u"},
158 static int parse_options(struct super_block *sb, char *options)
161 struct adfs_sb_info *asb = ADFS_SB(sb);
167 while ((p = strsep(&options, ",")) != NULL) {
168 substring_t args[MAX_OPT_ARGS];
173 token = match_token(p, tokens, args);
176 if (match_int(args, &option))
178 asb->s_uid = make_kuid(current_user_ns(), option);
179 if (!uid_valid(asb->s_uid))
183 if (match_int(args, &option))
185 asb->s_gid = make_kgid(current_user_ns(), option);
186 if (!gid_valid(asb->s_gid))
190 if (match_octal(args, &option))
192 asb->s_owner_mask = option;
195 if (match_octal(args, &option))
197 asb->s_other_mask = option;
200 if (match_int(args, &option))
202 asb->s_ftsuffix = option;
205 printk("ADFS-fs: unrecognised mount option \"%s\" "
206 "or missing value\n", p);
213 static int adfs_remount(struct super_block *sb, int *flags, char *data)
216 *flags |= SB_NODIRATIME;
217 return parse_options(sb, data);
220 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
222 struct super_block *sb = dentry->d_sb;
223 struct adfs_sb_info *sbi = ADFS_SB(sb);
224 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
226 buf->f_type = ADFS_SUPER_MAGIC;
227 buf->f_namelen = sbi->s_namelen;
228 buf->f_bsize = sb->s_blocksize;
229 buf->f_blocks = sbi->s_size;
230 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size;
232 buf->f_bfree = adfs_map_free(sb);
233 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
234 buf->f_fsid.val[0] = (u32)id;
235 buf->f_fsid.val[1] = (u32)(id >> 32);
240 static struct kmem_cache *adfs_inode_cachep;
242 static struct inode *adfs_alloc_inode(struct super_block *sb)
244 struct adfs_inode_info *ei;
245 ei = kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
248 return &ei->vfs_inode;
251 static void adfs_i_callback(struct rcu_head *head)
253 struct inode *inode = container_of(head, struct inode, i_rcu);
254 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
257 static void adfs_destroy_inode(struct inode *inode)
259 call_rcu(&inode->i_rcu, adfs_i_callback);
262 static void init_once(void *foo)
264 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
266 inode_init_once(&ei->vfs_inode);
269 static int __init init_inodecache(void)
271 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
272 sizeof(struct adfs_inode_info),
273 0, (SLAB_RECLAIM_ACCOUNT|
274 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
276 if (adfs_inode_cachep == NULL)
281 static void destroy_inodecache(void)
284 * Make sure all delayed rcu free inodes are flushed before we
288 kmem_cache_destroy(adfs_inode_cachep);
291 static const struct super_operations adfs_sops = {
292 .alloc_inode = adfs_alloc_inode,
293 .destroy_inode = adfs_destroy_inode,
294 .drop_inode = generic_delete_inode,
295 .write_inode = adfs_write_inode,
296 .put_super = adfs_put_super,
297 .statfs = adfs_statfs,
298 .remount_fs = adfs_remount,
299 .show_options = adfs_show_options,
302 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
304 struct adfs_discmap *dm;
305 unsigned int map_addr, zone_size, nzones;
307 struct adfs_sb_info *asb = ADFS_SB(sb);
309 nzones = asb->s_map_size;
310 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
311 map_addr = (nzones >> 1) * zone_size -
312 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
313 map_addr = signed_asl(map_addr, asb->s_map2blk);
315 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
317 dm = kmalloc_array(nzones, sizeof(*dm), GFP_KERNEL);
319 adfs_error(sb, "not enough memory");
320 return ERR_PTR(-ENOMEM);
323 for (zone = 0; zone < nzones; zone++, map_addr++) {
324 dm[zone].dm_startbit = 0;
325 dm[zone].dm_endbit = zone_size;
326 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
327 dm[zone].dm_bh = sb_bread(sb, map_addr);
329 if (!dm[zone].dm_bh) {
330 adfs_error(sb, "unable to read map");
335 /* adjust the limits for the first and last map zones */
337 dm[0].dm_startblk = 0;
338 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
339 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
340 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
341 (ADFS_DR_SIZE_BITS - i * zone_size);
343 if (adfs_checkmap(sb, dm))
346 adfs_error(sb, "map corrupted");
350 brelse(dm[zone].dm_bh);
353 return ERR_PTR(-EIO);
356 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
358 unsigned long discsize;
360 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
361 discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
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 |= SB_NODIRATIME;
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_error(sb, "unable to read superblock");
400 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
402 if (adfs_checkbblk(b_data)) {
404 printk("VFS: Can't find an adfs filesystem on dev "
410 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
413 * Do some sanity checks on the ADFS disc record
415 if (adfs_checkdiscrecord(dr)) {
417 printk("VPS: Can't find an adfs filesystem on dev "
424 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
425 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
427 adfs_error(sb, "couldn't read superblock on "
432 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
433 if (adfs_checkbblk(b_data)) {
434 adfs_error(sb, "disc record mismatch, very weird!");
438 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
441 printk(KERN_ERR "VFS: Unsupported blocksize on dev "
448 * blocksize on this device should now be set to the ADFS log2secsize
451 sb->s_magic = ADFS_SUPER_MAGIC;
452 asb->s_idlen = dr->idlen;
453 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
454 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
455 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits);
456 asb->s_version = dr->format_version;
457 asb->s_log2sharesize = dr->log2sharesize;
459 asb->s_map = adfs_read_map(sb, dr);
460 if (IS_ERR(asb->s_map)) {
461 ret = PTR_ERR(asb->s_map);
468 * set up enough so that we can read an inode
470 sb->s_op = &adfs_sops;
472 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
474 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
475 root_obj.name_len = 0;
476 /* Set root object date as 01 Jan 1987 00:00:00 */
477 root_obj.loadaddr = 0xfff0003f;
478 root_obj.execaddr = 0xec22c000;
479 root_obj.size = ADFS_NEWDIR_SIZE;
480 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
481 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
482 root_obj.filetype = -1;
485 * If this is a F+ disk with variable length directories,
486 * get the root_size from the disc record.
488 if (asb->s_version) {
489 root_obj.size = le32_to_cpu(dr->root_size);
490 asb->s_dir = &adfs_fplus_dir_ops;
491 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
493 asb->s_dir = &adfs_f_dir_ops;
494 asb->s_namelen = ADFS_F_NAME_LEN;
497 * ,xyz hex filetype suffix may be added by driver
498 * to files that have valid RISC OS filetype
503 sb->s_d_op = &adfs_dentry_operations;
504 root = adfs_iget(sb, &root_obj);
505 sb->s_root = d_make_root(root);
508 for (i = 0; i < asb->s_map_size; i++)
509 brelse(asb->s_map[i].dm_bh);
511 adfs_error(sb, "get root inode failed\n");
520 sb->s_fs_info = NULL;
525 static struct dentry *adfs_mount(struct file_system_type *fs_type,
526 int flags, const char *dev_name, void *data)
528 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super);
531 static struct file_system_type adfs_fs_type = {
532 .owner = THIS_MODULE,
535 .kill_sb = kill_block_super,
536 .fs_flags = FS_REQUIRES_DEV,
538 MODULE_ALIAS_FS("adfs");
540 static int __init init_adfs_fs(void)
542 int err = init_inodecache();
545 err = register_filesystem(&adfs_fs_type);
550 destroy_inodecache();
555 static void __exit exit_adfs_fs(void)
557 unregister_filesystem(&adfs_fs_type);
558 destroy_inodecache();
561 module_init(init_adfs_fs)
562 module_exit(exit_adfs_fs)
563 MODULE_LICENSE("GPL");