linux/fs/bfs/inode.c
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   1/*
   2 *      fs/bfs/inode.c
   3 *      BFS superblock and inode operations.
   4 *      Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
   5 *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
   6 *
   7 *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/mm.h>
  12#include <linux/slab.h>
  13#include <linux/init.h>
  14#include <linux/fs.h>
  15#include <linux/smp_lock.h>
  16#include <linux/buffer_head.h>
  17#include <linux/vfs.h>
  18#include <asm/uaccess.h>
  19#include "bfs.h"
  20
  21MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
  22MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
  23MODULE_LICENSE("GPL");
  24
  25#undef DEBUG
  26
  27#ifdef DEBUG
  28#define dprintf(x...)   printf(x)
  29#else
  30#define dprintf(x...)
  31#endif
  32
  33static void bfs_write_super(struct super_block *s);
  34void dump_imap(const char *prefix, struct super_block *s);
  35
  36struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
  37{
  38        struct bfs_inode *di;
  39        struct inode *inode;
  40        struct buffer_head *bh;
  41        int block, off;
  42
  43        inode = iget_locked(sb, ino);
  44        if (IS_ERR(inode))
  45                return ERR_PTR(-ENOMEM);
  46        if (!(inode->i_state & I_NEW))
  47                return inode;
  48
  49        if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
  50                printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
  51                goto error;
  52        }
  53
  54        block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
  55        bh = sb_bread(inode->i_sb, block);
  56        if (!bh) {
  57                printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
  58                                                                        ino);
  59                goto error;
  60        }
  61
  62        off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
  63        di = (struct bfs_inode *)bh->b_data + off;
  64
  65        inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
  66        if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
  67                inode->i_mode |= S_IFDIR;
  68                inode->i_op = &bfs_dir_inops;
  69                inode->i_fop = &bfs_dir_operations;
  70        } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
  71                inode->i_mode |= S_IFREG;
  72                inode->i_op = &bfs_file_inops;
  73                inode->i_fop = &bfs_file_operations;
  74                inode->i_mapping->a_ops = &bfs_aops;
  75        }
  76
  77        BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
  78        BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
  79        BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
  80        inode->i_uid =  le32_to_cpu(di->i_uid);
  81        inode->i_gid =  le32_to_cpu(di->i_gid);
  82        inode->i_nlink =  le32_to_cpu(di->i_nlink);
  83        inode->i_size = BFS_FILESIZE(di);
  84        inode->i_blocks = BFS_FILEBLOCKS(di);
  85        inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
  86        inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
  87        inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
  88        inode->i_atime.tv_nsec = 0;
  89        inode->i_mtime.tv_nsec = 0;
  90        inode->i_ctime.tv_nsec = 0;
  91
  92        brelse(bh);
  93        unlock_new_inode(inode);
  94        return inode;
  95
  96error:
  97        iget_failed(inode);
  98        return ERR_PTR(-EIO);
  99}
 100
 101static int bfs_write_inode(struct inode *inode, int wait)
 102{
 103        struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 104        unsigned int ino = (u16)inode->i_ino;
 105        unsigned long i_sblock;
 106        struct bfs_inode *di;
 107        struct buffer_head *bh;
 108        int block, off;
 109        int err = 0;
 110
 111        dprintf("ino=%08x\n", ino);
 112
 113        if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
 114                printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
 115                return -EIO;
 116        }
 117
 118        mutex_lock(&info->bfs_lock);
 119        block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 120        bh = sb_bread(inode->i_sb, block);
 121        if (!bh) {
 122                printf("Unable to read inode %s:%08x\n",
 123                                inode->i_sb->s_id, ino);
 124                mutex_unlock(&info->bfs_lock);
 125                return -EIO;
 126        }
 127
 128        off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 129        di = (struct bfs_inode *)bh->b_data + off;
 130
 131        if (ino == BFS_ROOT_INO)
 132                di->i_vtype = cpu_to_le32(BFS_VDIR);
 133        else
 134                di->i_vtype = cpu_to_le32(BFS_VREG);
 135
 136        di->i_ino = cpu_to_le16(ino);
 137        di->i_mode = cpu_to_le32(inode->i_mode);
 138        di->i_uid = cpu_to_le32(inode->i_uid);
 139        di->i_gid = cpu_to_le32(inode->i_gid);
 140        di->i_nlink = cpu_to_le32(inode->i_nlink);
 141        di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 142        di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 143        di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 144        i_sblock = BFS_I(inode)->i_sblock;
 145        di->i_sblock = cpu_to_le32(i_sblock);
 146        di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 147        di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 148
 149        mark_buffer_dirty(bh);
 150        if (wait) {
 151                sync_dirty_buffer(bh);
 152                if (buffer_req(bh) && !buffer_uptodate(bh))
 153                        err = -EIO;
 154        }
 155        brelse(bh);
 156        mutex_unlock(&info->bfs_lock);
 157        return err;
 158}
 159
 160static void bfs_delete_inode(struct inode *inode)
 161{
 162        unsigned long ino = inode->i_ino;
 163        struct bfs_inode *di;
 164        struct buffer_head *bh;
 165        int block, off;
 166        struct super_block *s = inode->i_sb;
 167        struct bfs_sb_info *info = BFS_SB(s);
 168        struct bfs_inode_info *bi = BFS_I(inode);
 169
 170        dprintf("ino=%08lx\n", ino);
 171
 172        truncate_inode_pages(&inode->i_data, 0);
 173
 174        if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
 175                printf("invalid ino=%08lx\n", ino);
 176                return;
 177        }
 178        
 179        inode->i_size = 0;
 180        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 181        mutex_lock(&info->bfs_lock);
 182        mark_inode_dirty(inode);
 183
 184        block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 185        bh = sb_bread(s, block);
 186        if (!bh) {
 187                printf("Unable to read inode %s:%08lx\n",
 188                                        inode->i_sb->s_id, ino);
 189                mutex_unlock(&info->bfs_lock);
 190                return;
 191        }
 192        off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 193        di = (struct bfs_inode *)bh->b_data + off;
 194        memset((void *)di, 0, sizeof(struct bfs_inode));
 195        mark_buffer_dirty(bh);
 196        brelse(bh);
 197
 198        if (bi->i_dsk_ino) {
 199                if (bi->i_sblock)
 200                        info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
 201                info->si_freei++;
 202                clear_bit(ino, info->si_imap);
 203                dump_imap("delete_inode", s);
 204        }
 205
 206        /*
 207         * If this was the last file, make the previous block
 208         * "last block of the last file" even if there is no
 209         * real file there, saves us 1 gap.
 210         */
 211        if (info->si_lf_eblk == bi->i_eblock) {
 212                info->si_lf_eblk = bi->i_sblock - 1;
 213                mark_buffer_dirty(info->si_sbh);
 214        }
 215        mutex_unlock(&info->bfs_lock);
 216        clear_inode(inode);
 217}
 218
 219static int bfs_sync_fs(struct super_block *sb, int wait)
 220{
 221        struct bfs_sb_info *info = BFS_SB(sb);
 222
 223        mutex_lock(&info->bfs_lock);
 224        mark_buffer_dirty(info->si_sbh);
 225        sb->s_dirt = 0;
 226        mutex_unlock(&info->bfs_lock);
 227
 228        return 0;
 229}
 230
 231static void bfs_write_super(struct super_block *sb)
 232{
 233        if (!(sb->s_flags & MS_RDONLY))
 234                bfs_sync_fs(sb, 1);
 235        else
 236                sb->s_dirt = 0;
 237}
 238
 239static void bfs_put_super(struct super_block *s)
 240{
 241        struct bfs_sb_info *info = BFS_SB(s);
 242
 243        if (!info)
 244                return;
 245
 246        lock_kernel();
 247
 248        if (s->s_dirt)
 249                bfs_write_super(s);
 250
 251        brelse(info->si_sbh);
 252        mutex_destroy(&info->bfs_lock);
 253        kfree(info->si_imap);
 254        kfree(info);
 255        s->s_fs_info = NULL;
 256
 257        unlock_kernel();
 258}
 259
 260static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 261{
 262        struct super_block *s = dentry->d_sb;
 263        struct bfs_sb_info *info = BFS_SB(s);
 264        u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 265        buf->f_type = BFS_MAGIC;
 266        buf->f_bsize = s->s_blocksize;
 267        buf->f_blocks = info->si_blocks;
 268        buf->f_bfree = buf->f_bavail = info->si_freeb;
 269        buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 270        buf->f_ffree = info->si_freei;
 271        buf->f_fsid.val[0] = (u32)id;
 272        buf->f_fsid.val[1] = (u32)(id >> 32);
 273        buf->f_namelen = BFS_NAMELEN;
 274        return 0;
 275}
 276
 277static struct kmem_cache *bfs_inode_cachep;
 278
 279static struct inode *bfs_alloc_inode(struct super_block *sb)
 280{
 281        struct bfs_inode_info *bi;
 282        bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 283        if (!bi)
 284                return NULL;
 285        return &bi->vfs_inode;
 286}
 287
 288static void bfs_destroy_inode(struct inode *inode)
 289{
 290        kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 291}
 292
 293static void init_once(void *foo)
 294{
 295        struct bfs_inode_info *bi = foo;
 296
 297        inode_init_once(&bi->vfs_inode);
 298}
 299
 300static int init_inodecache(void)
 301{
 302        bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 303                                             sizeof(struct bfs_inode_info),
 304                                             0, (SLAB_RECLAIM_ACCOUNT|
 305                                                SLAB_MEM_SPREAD),
 306                                             init_once);
 307        if (bfs_inode_cachep == NULL)
 308                return -ENOMEM;
 309        return 0;
 310}
 311
 312static void destroy_inodecache(void)
 313{
 314        kmem_cache_destroy(bfs_inode_cachep);
 315}
 316
 317static const struct super_operations bfs_sops = {
 318        .alloc_inode    = bfs_alloc_inode,
 319        .destroy_inode  = bfs_destroy_inode,
 320        .write_inode    = bfs_write_inode,
 321        .delete_inode   = bfs_delete_inode,
 322        .put_super      = bfs_put_super,
 323        .write_super    = bfs_write_super,
 324        .sync_fs        = bfs_sync_fs,
 325        .statfs         = bfs_statfs,
 326};
 327
 328void dump_imap(const char *prefix, struct super_block *s)
 329{
 330#ifdef DEBUG
 331        int i;
 332        char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 333
 334        if (!tmpbuf)
 335                return;
 336        for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 337                if (i > PAGE_SIZE - 100) break;
 338                if (test_bit(i, BFS_SB(s)->si_imap))
 339                        strcat(tmpbuf, "1");
 340                else
 341                        strcat(tmpbuf, "0");
 342        }
 343        printf("BFS-fs: %s: lasti=%08lx <%s>\n",
 344                                prefix, BFS_SB(s)->si_lasti, tmpbuf);
 345        free_page((unsigned long)tmpbuf);
 346#endif
 347}
 348
 349static int bfs_fill_super(struct super_block *s, void *data, int silent)
 350{
 351        struct buffer_head *bh;
 352        struct bfs_super_block *bfs_sb;
 353        struct inode *inode;
 354        unsigned i, imap_len;
 355        struct bfs_sb_info *info;
 356        long ret = -EINVAL;
 357        unsigned long i_sblock, i_eblock, i_eoff, s_size;
 358
 359        info = kzalloc(sizeof(*info), GFP_KERNEL);
 360        if (!info)
 361                return -ENOMEM;
 362        s->s_fs_info = info;
 363
 364        sb_set_blocksize(s, BFS_BSIZE);
 365
 366        bh = sb_bread(s, 0);
 367        if(!bh)
 368                goto out;
 369        bfs_sb = (struct bfs_super_block *)bh->b_data;
 370        if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 371                if (!silent)
 372                        printf("No BFS filesystem on %s (magic=%08x)\n", 
 373                                s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 374                goto out;
 375        }
 376        if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 377                printf("%s is unclean, continuing\n", s->s_id);
 378
 379        s->s_magic = BFS_MAGIC;
 380        info->si_sbh = bh;
 381
 382        if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
 383                printf("Superblock is corrupted\n");
 384                goto out;
 385        }
 386
 387        info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
 388                                        sizeof(struct bfs_inode)
 389                                        + BFS_ROOT_INO - 1;
 390        imap_len = (info->si_lasti / 8) + 1;
 391        info->si_imap = kzalloc(imap_len, GFP_KERNEL);
 392        if (!info->si_imap)
 393                goto out;
 394        for (i = 0; i < BFS_ROOT_INO; i++)
 395                set_bit(i, info->si_imap);
 396
 397        s->s_op = &bfs_sops;
 398        inode = bfs_iget(s, BFS_ROOT_INO);
 399        if (IS_ERR(inode)) {
 400                ret = PTR_ERR(inode);
 401                kfree(info->si_imap);
 402                goto out;
 403        }
 404        s->s_root = d_alloc_root(inode);
 405        if (!s->s_root) {
 406                iput(inode);
 407                ret = -ENOMEM;
 408                kfree(info->si_imap);
 409                goto out;
 410        }
 411
 412        info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 413        info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
 414                        - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 415        info->si_freei = 0;
 416        info->si_lf_eblk = 0;
 417
 418        /* can we read the last block? */
 419        bh = sb_bread(s, info->si_blocks - 1);
 420        if (!bh) {
 421                printf("Last block not available: %lu\n", info->si_blocks - 1);
 422                iput(inode);
 423                ret = -EIO;
 424                kfree(info->si_imap);
 425                goto out;
 426        }
 427        brelse(bh);
 428
 429        bh = NULL;
 430        for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 431                struct bfs_inode *di;
 432                int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 433                int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 434                unsigned long eblock;
 435
 436                if (!off) {
 437                        brelse(bh);
 438                        bh = sb_bread(s, block);
 439                }
 440
 441                if (!bh)
 442                        continue;
 443
 444                di = (struct bfs_inode *)bh->b_data + off;
 445
 446                /* test if filesystem is not corrupted */
 447
 448                i_eoff = le32_to_cpu(di->i_eoffset);
 449                i_sblock = le32_to_cpu(di->i_sblock);
 450                i_eblock = le32_to_cpu(di->i_eblock);
 451                s_size = le32_to_cpu(bfs_sb->s_end);
 452
 453                if (i_sblock > info->si_blocks ||
 454                        i_eblock > info->si_blocks ||
 455                        i_sblock > i_eblock ||
 456                        i_eoff > s_size ||
 457                        i_sblock * BFS_BSIZE > i_eoff) {
 458
 459                        printf("Inode 0x%08x corrupted\n", i);
 460
 461                        brelse(bh);
 462                        s->s_root = NULL;
 463                        kfree(info->si_imap);
 464                        kfree(info);
 465                        s->s_fs_info = NULL;
 466                        return -EIO;
 467                }
 468
 469                if (!di->i_ino) {
 470                        info->si_freei++;
 471                        continue;
 472                }
 473                set_bit(i, info->si_imap);
 474                info->si_freeb -= BFS_FILEBLOCKS(di);
 475
 476                eblock =  le32_to_cpu(di->i_eblock);
 477                if (eblock > info->si_lf_eblk)
 478                        info->si_lf_eblk = eblock;
 479        }
 480        brelse(bh);
 481        if (!(s->s_flags & MS_RDONLY)) {
 482                mark_buffer_dirty(info->si_sbh);
 483                s->s_dirt = 1;
 484        } 
 485        dump_imap("read_super", s);
 486        mutex_init(&info->bfs_lock);
 487        return 0;
 488
 489out:
 490        brelse(bh);
 491        kfree(info);
 492        s->s_fs_info = NULL;
 493        return ret;
 494}
 495
 496static int bfs_get_sb(struct file_system_type *fs_type,
 497        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 498{
 499        return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
 500}
 501
 502static struct file_system_type bfs_fs_type = {
 503        .owner          = THIS_MODULE,
 504        .name           = "bfs",
 505        .get_sb         = bfs_get_sb,
 506        .kill_sb        = kill_block_super,
 507        .fs_flags       = FS_REQUIRES_DEV,
 508};
 509
 510static int __init init_bfs_fs(void)
 511{
 512        int err = init_inodecache();
 513        if (err)
 514                goto out1;
 515        err = register_filesystem(&bfs_fs_type);
 516        if (err)
 517                goto out;
 518        return 0;
 519out:
 520        destroy_inodecache();
 521out1:
 522        return err;
 523}
 524
 525static void __exit exit_bfs_fs(void)
 526{
 527        unregister_filesystem(&bfs_fs_type);
 528        destroy_inodecache();
 529}
 530
 531module_init(init_bfs_fs)
 532module_exit(exit_bfs_fs)
 533