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/parser.h>
10 #include <linux/mount.h>
11 #include <linux/seq_file.h>
12 #include <linux/slab.h>
13 #include <linux/statfs.h>
14 #include <linux/user_namespace.h>
15 #include <linux/blkdev.h>
18 #include "dir_fplus.h"
20 #define ADFS_SB_FLAGS SB_NOATIME
22 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
23 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
25 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
34 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n",
35 sb->s_id, function ? ": " : "",
36 function ? function : "", &vaf);
41 void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)
49 printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf);
53 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
55 unsigned int max_idlen;
58 /* sector size must be 256, 512 or 1024 bytes */
59 if (dr->log2secsize != 8 &&
60 dr->log2secsize != 9 &&
61 dr->log2secsize != 10)
64 /* idlen must be at least log2secsize + 3 */
65 if (dr->idlen < dr->log2secsize + 3)
68 /* we cannot have such a large disc that we
69 * are unable to represent sector offsets in
70 * 32 bits. This works out at 2.0 TB.
72 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
76 * Maximum idlen is limited to 16 bits for new directories by
77 * the three-byte storage of an indirect disc address. For
78 * big directories, idlen must be no greater than 19 v2 [1.0]
80 max_idlen = dr->format_version ? 19 : 16;
81 if (dr->idlen > max_idlen)
84 /* reserved bytes should be zero */
85 for (i = 0; i < sizeof(dr->unused52); i++)
86 if (dr->unused52[i] != 0)
92 static void adfs_put_super(struct super_block *sb)
94 struct adfs_sb_info *asb = ADFS_SB(sb);
100 static int adfs_show_options(struct seq_file *seq, struct dentry *root)
102 struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
104 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
105 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
106 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
107 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
108 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
109 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
110 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
111 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
112 if (asb->s_ftsuffix != 0)
113 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
118 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};
120 static const match_table_t tokens = {
123 {Opt_ownmask, "ownmask=%o"},
124 {Opt_othmask, "othmask=%o"},
125 {Opt_ftsuffix, "ftsuffix=%u"},
129 static int parse_options(struct super_block *sb, struct adfs_sb_info *asb,
138 while ((p = strsep(&options, ",")) != NULL) {
139 substring_t args[MAX_OPT_ARGS];
144 token = match_token(p, tokens, args);
147 if (match_int(args, &option))
149 asb->s_uid = make_kuid(current_user_ns(), option);
150 if (!uid_valid(asb->s_uid))
154 if (match_int(args, &option))
156 asb->s_gid = make_kgid(current_user_ns(), option);
157 if (!gid_valid(asb->s_gid))
161 if (match_octal(args, &option))
163 asb->s_owner_mask = option;
166 if (match_octal(args, &option))
168 asb->s_other_mask = option;
171 if (match_int(args, &option))
173 asb->s_ftsuffix = option;
176 adfs_msg(sb, KERN_ERR,
177 "unrecognised mount option \"%s\" or missing value",
185 static int adfs_remount(struct super_block *sb, int *flags, char *data)
187 struct adfs_sb_info temp_asb;
191 *flags |= ADFS_SB_FLAGS;
193 temp_asb = *ADFS_SB(sb);
194 ret = parse_options(sb, &temp_asb, data);
196 *ADFS_SB(sb) = temp_asb;
201 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
203 struct super_block *sb = dentry->d_sb;
204 struct adfs_sb_info *sbi = ADFS_SB(sb);
205 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
207 adfs_map_statfs(sb, buf);
209 buf->f_type = ADFS_SUPER_MAGIC;
210 buf->f_namelen = sbi->s_namelen;
211 buf->f_bsize = sb->s_blocksize;
212 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
213 buf->f_fsid.val[0] = (u32)id;
214 buf->f_fsid.val[1] = (u32)(id >> 32);
219 static struct kmem_cache *adfs_inode_cachep;
221 static struct inode *adfs_alloc_inode(struct super_block *sb)
223 struct adfs_inode_info *ei;
224 ei = kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
227 return &ei->vfs_inode;
230 static void adfs_free_inode(struct inode *inode)
232 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
235 static int adfs_drop_inode(struct inode *inode)
237 /* always drop inodes if we are read-only */
238 return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode);
241 static void init_once(void *foo)
243 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
245 inode_init_once(&ei->vfs_inode);
248 static int __init init_inodecache(void)
250 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
251 sizeof(struct adfs_inode_info),
252 0, (SLAB_RECLAIM_ACCOUNT|
253 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
255 if (adfs_inode_cachep == NULL)
260 static void destroy_inodecache(void)
263 * Make sure all delayed rcu free inodes are flushed before we
267 kmem_cache_destroy(adfs_inode_cachep);
270 static const struct super_operations adfs_sops = {
271 .alloc_inode = adfs_alloc_inode,
272 .free_inode = adfs_free_inode,
273 .drop_inode = adfs_drop_inode,
274 .write_inode = adfs_write_inode,
275 .put_super = adfs_put_super,
276 .statfs = adfs_statfs,
277 .remount_fs = adfs_remount,
278 .show_options = adfs_show_options,
281 static int adfs_probe(struct super_block *sb, unsigned int offset, int silent,
282 int (*validate)(struct super_block *sb,
283 struct buffer_head *bh,
284 struct adfs_discrecord **bhp))
286 struct adfs_sb_info *asb = ADFS_SB(sb);
287 struct adfs_discrecord *dr;
288 struct buffer_head *bh;
289 unsigned int blocksize = BLOCK_SIZE;
292 for (try = 0; try < 2; try++) {
293 /* try to set the requested block size */
294 if (sb->s_blocksize != blocksize &&
295 !sb_set_blocksize(sb, blocksize)) {
297 adfs_msg(sb, KERN_ERR,
298 "error: unsupported blocksize");
302 /* read the buffer */
303 bh = sb_bread(sb, offset >> sb->s_blocksize_bits);
305 adfs_msg(sb, KERN_ERR,
306 "error: unable to read block %u, try %d",
307 offset >> sb->s_blocksize_bits, try);
312 ret = validate(sb, bh, &dr);
318 /* does the block size match the filesystem block size? */
319 blocksize = 1 << dr->log2secsize;
320 if (sb->s_blocksize == blocksize) {
321 asb->s_map = adfs_read_map(sb, dr);
323 return PTR_ERR_OR_ZERO(asb->s_map);
332 static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh,
333 struct adfs_discrecord **drp)
335 struct adfs_discrecord *dr;
336 unsigned char *b_data;
338 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
339 if (adfs_checkbblk(b_data))
342 /* Do some sanity checks on the ADFS disc record */
343 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
344 if (adfs_checkdiscrecord(dr))
351 static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh,
352 struct adfs_discrecord **drp)
354 struct adfs_discrecord *dr;
356 /* Do some sanity checks on the ADFS disc record */
357 dr = (struct adfs_discrecord *)(bh->b_data + 4);
358 if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1)
365 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
367 struct adfs_discrecord *dr;
368 struct object_info root_obj;
369 struct adfs_sb_info *asb;
373 sb->s_flags |= ADFS_SB_FLAGS;
375 asb = kzalloc(sizeof(*asb), GFP_KERNEL);
380 sb->s_magic = ADFS_SUPER_MAGIC;
381 sb->s_time_gran = 10000000;
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, asb, data))
393 /* Try to probe the filesystem boot block */
394 ret = adfs_probe(sb, ADFS_DISCRECORD, 1, adfs_validate_bblk);
396 ret = adfs_probe(sb, 0, silent, adfs_validate_dr0);
397 if (ret == -EILSEQ) {
399 adfs_msg(sb, KERN_ERR,
400 "error: can't find an ADFS filesystem on dev %s.",
407 /* set up enough so that we can read an inode */
408 sb->s_op = &adfs_sops;
410 dr = adfs_map_discrecord(asb->s_map);
412 root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root);
413 root_obj.name_len = 0;
414 /* Set root object date as 01 Jan 1987 00:00:00 */
415 root_obj.loadaddr = 0xfff0003f;
416 root_obj.execaddr = 0xec22c000;
417 root_obj.size = ADFS_NEWDIR_SIZE;
418 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
419 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
422 * If this is a F+ disk with variable length directories,
423 * get the root_size from the disc record.
425 if (dr->format_version) {
426 root_obj.size = le32_to_cpu(dr->root_size);
427 asb->s_dir = &adfs_fplus_dir_ops;
428 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
430 asb->s_dir = &adfs_f_dir_ops;
431 asb->s_namelen = ADFS_F_NAME_LEN;
434 * ,xyz hex filetype suffix may be added by driver
435 * to files that have valid RISC OS filetype
440 sb->s_d_op = &adfs_dentry_operations;
441 root = adfs_iget(sb, &root_obj);
442 sb->s_root = d_make_root(root);
445 adfs_error(sb, "get root inode failed\n");
452 sb->s_fs_info = NULL;
457 static struct dentry *adfs_mount(struct file_system_type *fs_type,
458 int flags, const char *dev_name, void *data)
460 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super);
463 static struct file_system_type adfs_fs_type = {
464 .owner = THIS_MODULE,
467 .kill_sb = kill_block_super,
468 .fs_flags = FS_REQUIRES_DEV,
470 MODULE_ALIAS_FS("adfs");
472 static int __init init_adfs_fs(void)
474 int err = init_inodecache();
477 err = register_filesystem(&adfs_fs_type);
482 destroy_inodecache();
487 static void __exit exit_adfs_fs(void)
489 unregister_filesystem(&adfs_fs_type);
490 destroy_inodecache();
493 module_init(init_adfs_fs)
494 module_exit(exit_adfs_fs)
495 MODULE_LICENSE("GPL");