linux/fs/adfs/super.c
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   1/*
   2 *  linux/fs/adfs/super.c
   3 *
   4 *  Copyright (C) 1997-1999 Russell King
   5 *
   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.
   9 */
  10#include <linux/module.h>
  11#include <linux/errno.h>
  12#include <linux/fs.h>
  13#include <linux/adfs_fs.h>
  14#include <linux/slab.h>
  15#include <linux/time.h>
  16#include <linux/stat.h>
  17#include <linux/string.h>
  18#include <linux/init.h>
  19#include <linux/buffer_head.h>
  20#include <linux/vfs.h>
  21#include <linux/parser.h>
  22#include <linux/bitops.h>
  23#include <linux/mount.h>
  24#include <linux/seq_file.h>
  25
  26#include <asm/uaccess.h>
  27#include <asm/system.h>
  28
  29#include <stdarg.h>
  30
  31#include "adfs.h"
  32#include "dir_f.h"
  33#include "dir_fplus.h"
  34
  35#define ADFS_DEFAULT_OWNER_MASK S_IRWXU
  36#define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
  37
  38void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
  39{
  40        char error_buf[128];
  41        va_list args;
  42
  43        va_start(args, fmt);
  44        vsnprintf(error_buf, sizeof(error_buf), fmt, args);
  45        va_end(args);
  46
  47        printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
  48                sb->s_id, function ? ": " : "",
  49                function ? function : "", error_buf);
  50}
  51
  52static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
  53{
  54        int i;
  55
  56        /* sector size must be 256, 512 or 1024 bytes */
  57        if (dr->log2secsize != 8 &&
  58            dr->log2secsize != 9 &&
  59            dr->log2secsize != 10)
  60                return 1;
  61
  62        /* idlen must be at least log2secsize + 3 */
  63        if (dr->idlen < dr->log2secsize + 3)
  64                return 1;
  65
  66        /* we cannot have such a large disc that we
  67         * are unable to represent sector offsets in
  68         * 32 bits.  This works out at 2.0 TB.
  69         */
  70        if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
  71                return 1;
  72
  73        /* idlen must be no greater than 19 v2 [1.0] */
  74        if (dr->idlen > 19)
  75                return 1;
  76
  77        /* reserved bytes should be zero */
  78        for (i = 0; i < sizeof(dr->unused52); i++)
  79                if (dr->unused52[i] != 0)
  80                        return 1;
  81
  82        return 0;
  83}
  84
  85static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
  86{
  87        unsigned int v0, v1, v2, v3;
  88        int i;
  89
  90        v0 = v1 = v2 = v3 = 0;
  91        for (i = sb->s_blocksize - 4; i; i -= 4) {
  92                v0 += map[i]     + (v3 >> 8);
  93                v3 &= 0xff;
  94                v1 += map[i + 1] + (v0 >> 8);
  95                v0 &= 0xff;
  96                v2 += map[i + 2] + (v1 >> 8);
  97                v1 &= 0xff;
  98                v3 += map[i + 3] + (v2 >> 8);
  99                v2 &= 0xff;
 100        }
 101        v0 +=           v3 >> 8;
 102        v1 += map[1] + (v0 >> 8);
 103        v2 += map[2] + (v1 >> 8);
 104        v3 += map[3] + (v2 >> 8);
 105
 106        return v0 ^ v1 ^ v2 ^ v3;
 107}
 108
 109static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
 110{
 111        unsigned char crosscheck = 0, zonecheck = 1;
 112        int i;
 113
 114        for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
 115                unsigned char *map;
 116
 117                map = dm[i].dm_bh->b_data;
 118
 119                if (adfs_calczonecheck(sb, map) != map[0]) {
 120                        adfs_error(sb, "zone %d fails zonecheck", i);
 121                        zonecheck = 0;
 122                }
 123                crosscheck ^= map[3];
 124        }
 125        if (crosscheck != 0xff)
 126                adfs_error(sb, "crosscheck != 0xff");
 127        return crosscheck == 0xff && zonecheck;
 128}
 129
 130static void adfs_put_super(struct super_block *sb)
 131{
 132        int i;
 133        struct adfs_sb_info *asb = ADFS_SB(sb);
 134
 135        for (i = 0; i < asb->s_map_size; i++)
 136                brelse(asb->s_map[i].dm_bh);
 137        kfree(asb->s_map);
 138        kfree(asb);
 139        sb->s_fs_info = NULL;
 140}
 141
 142static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
 143{
 144        struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_sb);
 145
 146        if (asb->s_uid != 0)
 147                seq_printf(seq, ",uid=%u", asb->s_uid);
 148        if (asb->s_gid != 0)
 149                seq_printf(seq, ",gid=%u", asb->s_gid);
 150        if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
 151                seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
 152        if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
 153                seq_printf(seq, ",othmask=%o", asb->s_other_mask);
 154
 155        return 0;
 156}
 157
 158enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err};
 159
 160static match_table_t tokens = {
 161        {Opt_uid, "uid=%u"},
 162        {Opt_gid, "gid=%u"},
 163        {Opt_ownmask, "ownmask=%o"},
 164        {Opt_othmask, "othmask=%o"},
 165        {Opt_err, NULL}
 166};
 167
 168static int parse_options(struct super_block *sb, char *options)
 169{
 170        char *p;
 171        struct adfs_sb_info *asb = ADFS_SB(sb);
 172        int option;
 173
 174        if (!options)
 175                return 0;
 176
 177        while ((p = strsep(&options, ",")) != NULL) {
 178                substring_t args[MAX_OPT_ARGS];
 179                int token;
 180                if (!*p)
 181                        continue;
 182
 183                token = match_token(p, tokens, args);
 184                switch (token) {
 185                case Opt_uid:
 186                        if (match_int(args, &option))
 187                                return -EINVAL;
 188                        asb->s_uid = option;
 189                        break;
 190                case Opt_gid:
 191                        if (match_int(args, &option))
 192                                return -EINVAL;
 193                        asb->s_gid = option;
 194                        break;
 195                case Opt_ownmask:
 196                        if (match_octal(args, &option))
 197                                return -EINVAL;
 198                        asb->s_owner_mask = option;
 199                        break;
 200                case Opt_othmask:
 201                        if (match_octal(args, &option))
 202                                return -EINVAL;
 203                        asb->s_other_mask = option;
 204                        break;
 205                default:
 206                        printk("ADFS-fs: unrecognised mount option \"%s\" "
 207                                        "or missing value\n", p);
 208                        return -EINVAL;
 209                }
 210        }
 211        return 0;
 212}
 213
 214static int adfs_remount(struct super_block *sb, int *flags, char *data)
 215{
 216        *flags |= MS_NODIRATIME;
 217        return parse_options(sb, data);
 218}
 219
 220static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 221{
 222        struct adfs_sb_info *asb = ADFS_SB(dentry->d_sb);
 223
 224        buf->f_type    = ADFS_SUPER_MAGIC;
 225        buf->f_namelen = asb->s_namelen;
 226        buf->f_bsize   = dentry->d_sb->s_blocksize;
 227        buf->f_blocks  = asb->s_size;
 228        buf->f_files   = asb->s_ids_per_zone * asb->s_map_size;
 229        buf->f_bavail  =
 230        buf->f_bfree   = adfs_map_free(dentry->d_sb);
 231        buf->f_ffree   = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
 232
 233        return 0;
 234}
 235
 236static struct kmem_cache *adfs_inode_cachep;
 237
 238static struct inode *adfs_alloc_inode(struct super_block *sb)
 239{
 240        struct adfs_inode_info *ei;
 241        ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
 242        if (!ei)
 243                return NULL;
 244        return &ei->vfs_inode;
 245}
 246
 247static void adfs_destroy_inode(struct inode *inode)
 248{
 249        kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
 250}
 251
 252static void init_once(struct kmem_cache *cachep, void *foo)
 253{
 254        struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
 255
 256        inode_init_once(&ei->vfs_inode);
 257}
 258
 259static int init_inodecache(void)
 260{
 261        adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
 262                                             sizeof(struct adfs_inode_info),
 263                                             0, (SLAB_RECLAIM_ACCOUNT|
 264                                                SLAB_MEM_SPREAD),
 265                                             init_once);
 266        if (adfs_inode_cachep == NULL)
 267                return -ENOMEM;
 268        return 0;
 269}
 270
 271static void destroy_inodecache(void)
 272{
 273        kmem_cache_destroy(adfs_inode_cachep);
 274}
 275
 276static const struct super_operations adfs_sops = {
 277        .alloc_inode    = adfs_alloc_inode,
 278        .destroy_inode  = adfs_destroy_inode,
 279        .write_inode    = adfs_write_inode,
 280        .put_super      = adfs_put_super,
 281        .statfs         = adfs_statfs,
 282        .remount_fs     = adfs_remount,
 283        .show_options   = adfs_show_options,
 284};
 285
 286static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
 287{
 288        struct adfs_discmap *dm;
 289        unsigned int map_addr, zone_size, nzones;
 290        int i, zone;
 291        struct adfs_sb_info *asb = ADFS_SB(sb);
 292
 293        nzones    = asb->s_map_size;
 294        zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
 295        map_addr  = (nzones >> 1) * zone_size -
 296                     ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
 297        map_addr  = signed_asl(map_addr, asb->s_map2blk);
 298
 299        asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
 300
 301        dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
 302        if (dm == NULL) {
 303                adfs_error(sb, "not enough memory");
 304                return NULL;
 305        }
 306
 307        for (zone = 0; zone < nzones; zone++, map_addr++) {
 308                dm[zone].dm_startbit = 0;
 309                dm[zone].dm_endbit   = zone_size;
 310                dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
 311                dm[zone].dm_bh       = sb_bread(sb, map_addr);
 312
 313                if (!dm[zone].dm_bh) {
 314                        adfs_error(sb, "unable to read map");
 315                        goto error_free;
 316                }
 317        }
 318
 319        /* adjust the limits for the first and last map zones */
 320        i = zone - 1;
 321        dm[0].dm_startblk = 0;
 322        dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
 323        dm[i].dm_endbit   = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
 324                            (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
 325                            (ADFS_DR_SIZE_BITS - i * zone_size);
 326
 327        if (adfs_checkmap(sb, dm))
 328                return dm;
 329
 330        adfs_error(sb, "map corrupted");
 331
 332error_free:
 333        while (--zone >= 0)
 334                brelse(dm[zone].dm_bh);
 335
 336        kfree(dm);
 337        return NULL;
 338}
 339
 340static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
 341{
 342        unsigned long discsize;
 343
 344        discsize  = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
 345        discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
 346
 347        return discsize;
 348}
 349
 350static int adfs_fill_super(struct super_block *sb, void *data, int silent)
 351{
 352        struct adfs_discrecord *dr;
 353        struct buffer_head *bh;
 354        struct object_info root_obj;
 355        unsigned char *b_data;
 356        struct adfs_sb_info *asb;
 357        struct inode *root;
 358
 359        sb->s_flags |= MS_NODIRATIME;
 360
 361        asb = kzalloc(sizeof(*asb), GFP_KERNEL);
 362        if (!asb)
 363                return -ENOMEM;
 364        sb->s_fs_info = asb;
 365
 366        /* set default options */
 367        asb->s_uid = 0;
 368        asb->s_gid = 0;
 369        asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
 370        asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
 371
 372        if (parse_options(sb, data))
 373                goto error;
 374
 375        sb_set_blocksize(sb, BLOCK_SIZE);
 376        if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
 377                adfs_error(sb, "unable to read superblock");
 378                goto error;
 379        }
 380
 381        b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
 382
 383        if (adfs_checkbblk(b_data)) {
 384                if (!silent)
 385                        printk("VFS: Can't find an adfs filesystem on dev "
 386                                "%s.\n", sb->s_id);
 387                goto error_free_bh;
 388        }
 389
 390        dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
 391
 392        /*
 393         * Do some sanity checks on the ADFS disc record
 394         */
 395        if (adfs_checkdiscrecord(dr)) {
 396                if (!silent)
 397                        printk("VPS: Can't find an adfs filesystem on dev "
 398                                "%s.\n", sb->s_id);
 399                goto error_free_bh;
 400        }
 401
 402        brelse(bh);
 403        if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
 404                bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
 405                if (!bh) {
 406                        adfs_error(sb, "couldn't read superblock on "
 407                                "2nd try.");
 408                        goto error;
 409                }
 410                b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
 411                if (adfs_checkbblk(b_data)) {
 412                        adfs_error(sb, "disc record mismatch, very weird!");
 413                        goto error_free_bh;
 414                }
 415                dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
 416        } else {
 417                if (!silent)
 418                        printk(KERN_ERR "VFS: Unsupported blocksize on dev "
 419                                "%s.\n", sb->s_id);
 420                goto error;
 421        }
 422
 423        /*
 424         * blocksize on this device should now be set to the ADFS log2secsize
 425         */
 426
 427        sb->s_magic             = ADFS_SUPER_MAGIC;
 428        asb->s_idlen            = dr->idlen;
 429        asb->s_map_size         = dr->nzones | (dr->nzones_high << 8);
 430        asb->s_map2blk          = dr->log2bpmb - dr->log2secsize;
 431        asb->s_size             = adfs_discsize(dr, sb->s_blocksize_bits);
 432        asb->s_version          = dr->format_version;
 433        asb->s_log2sharesize    = dr->log2sharesize;
 434        
 435        asb->s_map = adfs_read_map(sb, dr);
 436        if (!asb->s_map)
 437                goto error_free_bh;
 438
 439        brelse(bh);
 440
 441        /*
 442         * set up enough so that we can read an inode
 443         */
 444        sb->s_op = &adfs_sops;
 445
 446        dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
 447
 448        root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
 449        root_obj.name_len  = 0;
 450        root_obj.loadaddr  = 0;
 451        root_obj.execaddr  = 0;
 452        root_obj.size      = ADFS_NEWDIR_SIZE;
 453        root_obj.attr      = ADFS_NDA_DIRECTORY   | ADFS_NDA_OWNER_READ |
 454                             ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
 455
 456        /*
 457         * If this is a F+ disk with variable length directories,
 458         * get the root_size from the disc record.
 459         */
 460        if (asb->s_version) {
 461                root_obj.size = le32_to_cpu(dr->root_size);
 462                asb->s_dir     = &adfs_fplus_dir_ops;
 463                asb->s_namelen = ADFS_FPLUS_NAME_LEN;
 464        } else {
 465                asb->s_dir     = &adfs_f_dir_ops;
 466                asb->s_namelen = ADFS_F_NAME_LEN;
 467        }
 468
 469        root = adfs_iget(sb, &root_obj);
 470        sb->s_root = d_alloc_root(root);
 471        if (!sb->s_root) {
 472                int i;
 473                iput(root);
 474                for (i = 0; i < asb->s_map_size; i++)
 475                        brelse(asb->s_map[i].dm_bh);
 476                kfree(asb->s_map);
 477                adfs_error(sb, "get root inode failed\n");
 478                goto error;
 479        } else
 480                sb->s_root->d_op = &adfs_dentry_operations;
 481        return 0;
 482
 483error_free_bh:
 484        brelse(bh);
 485error:
 486        sb->s_fs_info = NULL;
 487        kfree(asb);
 488        return -EINVAL;
 489}
 490
 491static int adfs_get_sb(struct file_system_type *fs_type,
 492        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 493{
 494        return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super,
 495                           mnt);
 496}
 497
 498static struct file_system_type adfs_fs_type = {
 499        .owner          = THIS_MODULE,
 500        .name           = "adfs",
 501        .get_sb         = adfs_get_sb,
 502        .kill_sb        = kill_block_super,
 503        .fs_flags       = FS_REQUIRES_DEV,
 504};
 505
 506static int __init init_adfs_fs(void)
 507{
 508        int err = init_inodecache();
 509        if (err)
 510                goto out1;
 511        err = register_filesystem(&adfs_fs_type);
 512        if (err)
 513                goto out;
 514        return 0;
 515out:
 516        destroy_inodecache();
 517out1:
 518        return err;
 519}
 520
 521static void __exit exit_adfs_fs(void)
 522{
 523        unregister_filesystem(&adfs_fs_type);
 524        destroy_inodecache();
 525}
 526
 527module_init(init_adfs_fs)
 528module_exit(exit_adfs_fs)
 529
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