496 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * linux/fs/adfs/super.c4 *5 * Copyright (C) 1997-1999 Russell King6 */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>16#include "adfs.h"17#include "dir_f.h"18#include "dir_fplus.h"19 20#define ADFS_SB_FLAGS SB_NOATIME21 22#define ADFS_DEFAULT_OWNER_MASK S_IRWXU23#define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)24 25void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)26{27 struct va_format vaf;28 va_list args;29 30 va_start(args, fmt);31 vaf.fmt = fmt;32 vaf.va = &args;33 34 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n",35 sb->s_id, function ? ": " : "",36 function ? function : "", &vaf);37 38 va_end(args);39}40 41void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)42{43 struct va_format vaf;44 va_list args;45 46 va_start(args, fmt);47 vaf.fmt = fmt;48 vaf.va = &args;49 printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf);50 va_end(args);51}52 53static int adfs_checkdiscrecord(struct adfs_discrecord *dr)54{55 unsigned int max_idlen;56 int i;57 58 /* sector size must be 256, 512 or 1024 bytes */59 if (dr->log2secsize != 8 &&60 dr->log2secsize != 9 &&61 dr->log2secsize != 10)62 return 1;63 64 /* idlen must be at least log2secsize + 3 */65 if (dr->idlen < dr->log2secsize + 3)66 return 1;67 68 /* we cannot have such a large disc that we69 * are unable to represent sector offsets in70 * 32 bits. This works out at 2.0 TB.71 */72 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)73 return 1;74 75 /*76 * Maximum idlen is limited to 16 bits for new directories by77 * the three-byte storage of an indirect disc address. For78 * big directories, idlen must be no greater than 19 v2 [1.0]79 */80 max_idlen = dr->format_version ? 19 : 16;81 if (dr->idlen > max_idlen)82 return 1;83 84 /* reserved bytes should be zero */85 for (i = 0; i < sizeof(dr->unused52); i++)86 if (dr->unused52[i] != 0)87 return 1;88 89 return 0;90}91 92static void adfs_put_super(struct super_block *sb)93{94 struct adfs_sb_info *asb = ADFS_SB(sb);95 96 adfs_free_map(sb);97 kfree_rcu(asb, rcu);98}99 100static int adfs_show_options(struct seq_file *seq, struct dentry *root)101{102 struct adfs_sb_info *asb = ADFS_SB(root->d_sb);103 104 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);114 115 return 0;116}117 118enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};119 120static const match_table_t tokens = {121 {Opt_uid, "uid=%u"},122 {Opt_gid, "gid=%u"},123 {Opt_ownmask, "ownmask=%o"},124 {Opt_othmask, "othmask=%o"},125 {Opt_ftsuffix, "ftsuffix=%u"},126 {Opt_err, NULL}127};128 129static int parse_options(struct super_block *sb, struct adfs_sb_info *asb,130 char *options)131{132 char *p;133 int option;134 135 if (!options)136 return 0;137 138 while ((p = strsep(&options, ",")) != NULL) {139 substring_t args[MAX_OPT_ARGS];140 int token;141 if (!*p)142 continue;143 144 token = match_token(p, tokens, args);145 switch (token) {146 case Opt_uid:147 if (match_int(args, &option))148 return -EINVAL;149 asb->s_uid = make_kuid(current_user_ns(), option);150 if (!uid_valid(asb->s_uid))151 return -EINVAL;152 break;153 case Opt_gid:154 if (match_int(args, &option))155 return -EINVAL;156 asb->s_gid = make_kgid(current_user_ns(), option);157 if (!gid_valid(asb->s_gid))158 return -EINVAL;159 break;160 case Opt_ownmask:161 if (match_octal(args, &option))162 return -EINVAL;163 asb->s_owner_mask = option;164 break;165 case Opt_othmask:166 if (match_octal(args, &option))167 return -EINVAL;168 asb->s_other_mask = option;169 break;170 case Opt_ftsuffix:171 if (match_int(args, &option))172 return -EINVAL;173 asb->s_ftsuffix = option;174 break;175 default:176 adfs_msg(sb, KERN_ERR,177 "unrecognised mount option \"%s\" or missing value",178 p);179 return -EINVAL;180 }181 }182 return 0;183}184 185static int adfs_remount(struct super_block *sb, int *flags, char *data)186{187 struct adfs_sb_info temp_asb;188 int ret;189 190 sync_filesystem(sb);191 *flags |= ADFS_SB_FLAGS;192 193 temp_asb = *ADFS_SB(sb);194 ret = parse_options(sb, &temp_asb, data);195 if (ret == 0)196 *ADFS_SB(sb) = temp_asb;197 198 return ret;199}200 201static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)202{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);206 207 adfs_map_statfs(sb, buf);208 209 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 = u64_to_fsid(id);214 215 return 0;216}217 218static struct kmem_cache *adfs_inode_cachep;219 220static struct inode *adfs_alloc_inode(struct super_block *sb)221{222 struct adfs_inode_info *ei;223 ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL);224 if (!ei)225 return NULL;226 return &ei->vfs_inode;227}228 229static void adfs_free_inode(struct inode *inode)230{231 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));232}233 234static int adfs_drop_inode(struct inode *inode)235{236 /* always drop inodes if we are read-only */237 return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode);238}239 240static void init_once(void *foo)241{242 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;243 244 inode_init_once(&ei->vfs_inode);245}246 247static int __init init_inodecache(void)248{249 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",250 sizeof(struct adfs_inode_info),251 0, (SLAB_RECLAIM_ACCOUNT|252 SLAB_ACCOUNT),253 init_once);254 if (adfs_inode_cachep == NULL)255 return -ENOMEM;256 return 0;257}258 259static void destroy_inodecache(void)260{261 /*262 * Make sure all delayed rcu free inodes are flushed before we263 * destroy cache.264 */265 rcu_barrier();266 kmem_cache_destroy(adfs_inode_cachep);267}268 269static const struct super_operations adfs_sops = {270 .alloc_inode = adfs_alloc_inode,271 .free_inode = adfs_free_inode,272 .drop_inode = adfs_drop_inode,273 .write_inode = adfs_write_inode,274 .put_super = adfs_put_super,275 .statfs = adfs_statfs,276 .remount_fs = adfs_remount,277 .show_options = adfs_show_options,278};279 280static int adfs_probe(struct super_block *sb, unsigned int offset, int silent,281 int (*validate)(struct super_block *sb,282 struct buffer_head *bh,283 struct adfs_discrecord **bhp))284{285 struct adfs_sb_info *asb = ADFS_SB(sb);286 struct adfs_discrecord *dr;287 struct buffer_head *bh;288 unsigned int blocksize = BLOCK_SIZE;289 int ret, try;290 291 for (try = 0; try < 2; try++) {292 /* try to set the requested block size */293 if (sb->s_blocksize != blocksize &&294 !sb_set_blocksize(sb, blocksize)) {295 if (!silent)296 adfs_msg(sb, KERN_ERR,297 "error: unsupported blocksize");298 return -EINVAL;299 }300 301 /* read the buffer */302 bh = sb_bread(sb, offset >> sb->s_blocksize_bits);303 if (!bh) {304 adfs_msg(sb, KERN_ERR,305 "error: unable to read block %u, try %d",306 offset >> sb->s_blocksize_bits, try);307 return -EIO;308 }309 310 /* validate it */311 ret = validate(sb, bh, &dr);312 if (ret) {313 brelse(bh);314 return ret;315 }316 317 /* does the block size match the filesystem block size? */318 blocksize = 1 << dr->log2secsize;319 if (sb->s_blocksize == blocksize) {320 asb->s_map = adfs_read_map(sb, dr);321 brelse(bh);322 return PTR_ERR_OR_ZERO(asb->s_map);323 }324 325 brelse(bh);326 }327 328 return -EIO;329}330 331static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh,332 struct adfs_discrecord **drp)333{334 struct adfs_discrecord *dr;335 unsigned char *b_data;336 337 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);338 if (adfs_checkbblk(b_data))339 return -EILSEQ;340 341 /* Do some sanity checks on the ADFS disc record */342 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);343 if (adfs_checkdiscrecord(dr))344 return -EILSEQ;345 346 *drp = dr;347 return 0;348}349 350static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh,351 struct adfs_discrecord **drp)352{353 struct adfs_discrecord *dr;354 355 /* Do some sanity checks on the ADFS disc record */356 dr = (struct adfs_discrecord *)(bh->b_data + 4);357 if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1)358 return -EILSEQ;359 360 *drp = dr;361 return 0;362}363 364static int adfs_fill_super(struct super_block *sb, void *data, int silent)365{366 struct adfs_discrecord *dr;367 struct object_info root_obj;368 struct adfs_sb_info *asb;369 struct inode *root;370 int ret = -EINVAL;371 372 sb->s_flags |= ADFS_SB_FLAGS;373 374 asb = kzalloc(sizeof(*asb), GFP_KERNEL);375 if (!asb)376 return -ENOMEM;377 378 sb->s_fs_info = asb;379 sb->s_magic = ADFS_SUPER_MAGIC;380 sb->s_time_gran = 10000000;381 382 /* set default options */383 asb->s_uid = GLOBAL_ROOT_UID;384 asb->s_gid = GLOBAL_ROOT_GID;385 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;386 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;387 asb->s_ftsuffix = 0;388 389 if (parse_options(sb, asb, data))390 goto error;391 392 /* Try to probe the filesystem boot block */393 ret = adfs_probe(sb, ADFS_DISCRECORD, 1, adfs_validate_bblk);394 if (ret == -EILSEQ)395 ret = adfs_probe(sb, 0, silent, adfs_validate_dr0);396 if (ret == -EILSEQ) {397 if (!silent)398 adfs_msg(sb, KERN_ERR,399 "error: can't find an ADFS filesystem on dev %s.",400 sb->s_id);401 ret = -EINVAL;402 }403 if (ret)404 goto error;405 406 /* set up enough so that we can read an inode */407 sb->s_op = &adfs_sops;408 409 dr = adfs_map_discrecord(asb->s_map);410 411 root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root);412 root_obj.name_len = 0;413 /* Set root object date as 01 Jan 1987 00:00:00 */414 root_obj.loadaddr = 0xfff0003f;415 root_obj.execaddr = 0xec22c000;416 root_obj.size = ADFS_NEWDIR_SIZE;417 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |418 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;419 420 /*421 * If this is a F+ disk with variable length directories,422 * get the root_size from the disc record.423 */424 if (dr->format_version) {425 root_obj.size = le32_to_cpu(dr->root_size);426 asb->s_dir = &adfs_fplus_dir_ops;427 asb->s_namelen = ADFS_FPLUS_NAME_LEN;428 } else {429 asb->s_dir = &adfs_f_dir_ops;430 asb->s_namelen = ADFS_F_NAME_LEN;431 }432 /*433 * ,xyz hex filetype suffix may be added by driver434 * to files that have valid RISC OS filetype435 */436 if (asb->s_ftsuffix)437 asb->s_namelen += 4;438 439 sb->s_d_op = &adfs_dentry_operations;440 root = adfs_iget(sb, &root_obj);441 sb->s_root = d_make_root(root);442 if (!sb->s_root) {443 adfs_free_map(sb);444 adfs_error(sb, "get root inode failed\n");445 ret = -EIO;446 goto error;447 }448 return 0;449 450error:451 sb->s_fs_info = NULL;452 kfree(asb);453 return ret;454}455 456static struct dentry *adfs_mount(struct file_system_type *fs_type,457 int flags, const char *dev_name, void *data)458{459 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super);460}461 462static struct file_system_type adfs_fs_type = {463 .owner = THIS_MODULE,464 .name = "adfs",465 .mount = adfs_mount,466 .kill_sb = kill_block_super,467 .fs_flags = FS_REQUIRES_DEV,468};469MODULE_ALIAS_FS("adfs");470 471static int __init init_adfs_fs(void)472{473 int err = init_inodecache();474 if (err)475 goto out1;476 err = register_filesystem(&adfs_fs_type);477 if (err)478 goto out;479 return 0;480out:481 destroy_inodecache();482out1:483 return err;484}485 486static void __exit exit_adfs_fs(void)487{488 unregister_filesystem(&adfs_fs_type);489 destroy_inodecache();490}491 492module_init(init_adfs_fs)493module_exit(exit_adfs_fs)494MODULE_DESCRIPTION("Acorn Disc Filing System");495MODULE_LICENSE("GPL");496