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/buffer_head.h>
  16#include <linux/vfs.h>
  17#include <linux/writeback.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
  33void dump_imap(const char *prefix, struct super_block *s);
  34
  35struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
  36{
  37        struct bfs_inode *di;
  38        struct inode *inode;
  39        struct buffer_head *bh;
  40        int block, off;
  41
  42        inode = iget_locked(sb, ino);
  43        if (IS_ERR(inode))
  44                return ERR_PTR(-ENOMEM);
  45        if (!(inode->i_state & I_NEW))
  46                return inode;
  47
  48        if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
  49                printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
  50                goto error;
  51        }
  52
  53        block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
  54        bh = sb_bread(inode->i_sb, block);
  55        if (!bh) {
  56                printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
  57                                                                        ino);
  58                goto error;
  59        }
  60
  61        off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
  62        di = (struct bfs_inode *)bh->b_data + off;
  63
  64        inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
  65        if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
  66                inode->i_mode |= S_IFDIR;
  67                inode->i_op = &bfs_dir_inops;
  68                inode->i_fop = &bfs_dir_operations;
  69        } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
  70                inode->i_mode |= S_IFREG;
  71                inode->i_op = &bfs_file_inops;
  72                inode->i_fop = &bfs_file_operations;
  73                inode->i_mapping->a_ops = &bfs_aops;
  74        }
  75
  76        BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
  77        BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
  78        BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
  79        i_uid_write(inode, le32_to_cpu(di->i_uid));
  80        i_gid_write(inode,  le32_to_cpu(di->i_gid));
  81        set_nlink(inode, le32_to_cpu(di->i_nlink));
  82        inode->i_size = BFS_FILESIZE(di);
  83        inode->i_blocks = BFS_FILEBLOCKS(di);
  84        inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
  85        inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
  86        inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
  87        inode->i_atime.tv_nsec = 0;
  88        inode->i_mtime.tv_nsec = 0;
  89        inode->i_ctime.tv_nsec = 0;
  90
  91        brelse(bh);
  92        unlock_new_inode(inode);
  93        return inode;
  94
  95error:
  96        iget_failed(inode);
  97        return ERR_PTR(-EIO);
  98}
  99
 100static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
 101{
 102        if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
 103                printf("Bad inode number %s:%08x\n", sb->s_id, ino);
 104                return ERR_PTR(-EIO);
 105        }
 106
 107        ino -= BFS_ROOT_INO;
 108
 109        *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
 110        if (!*p) {
 111                printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
 112                return ERR_PTR(-EIO);
 113        }
 114
 115        return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
 116}
 117
 118static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 119{
 120        struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 121        unsigned int ino = (u16)inode->i_ino;
 122        unsigned long i_sblock;
 123        struct bfs_inode *di;
 124        struct buffer_head *bh;
 125        int err = 0;
 126
 127        dprintf("ino=%08x\n", ino);
 128
 129        di = find_inode(inode->i_sb, ino, &bh);
 130        if (IS_ERR(di))
 131                return PTR_ERR(di);
 132
 133        mutex_lock(&info->bfs_lock);
 134
 135        if (ino == BFS_ROOT_INO)
 136                di->i_vtype = cpu_to_le32(BFS_VDIR);
 137        else
 138                di->i_vtype = cpu_to_le32(BFS_VREG);
 139
 140        di->i_ino = cpu_to_le16(ino);
 141        di->i_mode = cpu_to_le32(inode->i_mode);
 142        di->i_uid = cpu_to_le32(i_uid_read(inode));
 143        di->i_gid = cpu_to_le32(i_gid_read(inode));
 144        di->i_nlink = cpu_to_le32(inode->i_nlink);
 145        di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 146        di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 147        di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 148        i_sblock = BFS_I(inode)->i_sblock;
 149        di->i_sblock = cpu_to_le32(i_sblock);
 150        di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 151        di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 152
 153        mark_buffer_dirty(bh);
 154        if (wbc->sync_mode == WB_SYNC_ALL) {
 155                sync_dirty_buffer(bh);
 156                if (buffer_req(bh) && !buffer_uptodate(bh))
 157                        err = -EIO;
 158        }
 159        brelse(bh);
 160        mutex_unlock(&info->bfs_lock);
 161        return err;
 162}
 163
 164static void bfs_evict_inode(struct inode *inode)
 165{
 166        unsigned long ino = inode->i_ino;
 167        struct bfs_inode *di;
 168        struct buffer_head *bh;
 169        struct super_block *s = inode->i_sb;
 170        struct bfs_sb_info *info = BFS_SB(s);
 171        struct bfs_inode_info *bi = BFS_I(inode);
 172
 173        dprintf("ino=%08lx\n", ino);
 174
 175        truncate_inode_pages(&inode->i_data, 0);
 176        invalidate_inode_buffers(inode);
 177        clear_inode(inode);
 178
 179        if (inode->i_nlink)
 180                return;
 181
 182        di = find_inode(s, inode->i_ino, &bh);
 183        if (IS_ERR(di))
 184                return;
 185
 186        mutex_lock(&info->bfs_lock);
 187        /* clear on-disk inode */
 188        memset(di, 0, sizeof(struct bfs_inode));
 189        mark_buffer_dirty(bh);
 190        brelse(bh);
 191
 192        if (bi->i_dsk_ino) {
 193                if (bi->i_sblock)
 194                        info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
 195                info->si_freei++;
 196                clear_bit(ino, info->si_imap);
 197                dump_imap("delete_inode", s);
 198        }
 199
 200        /*
 201         * If this was the last file, make the previous block
 202         * "last block of the last file" even if there is no
 203         * real file there, saves us 1 gap.
 204         */
 205        if (info->si_lf_eblk == bi->i_eblock)
 206                info->si_lf_eblk = bi->i_sblock - 1;
 207        mutex_unlock(&info->bfs_lock);
 208}
 209
 210static void bfs_put_super(struct super_block *s)
 211{
 212        struct bfs_sb_info *info = BFS_SB(s);
 213
 214        if (!info)
 215                return;
 216
 217        mutex_destroy(&info->bfs_lock);
 218        kfree(info->si_imap);
 219        kfree(info);
 220        s->s_fs_info = NULL;
 221}
 222
 223static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 224{
 225        struct super_block *s = dentry->d_sb;
 226        struct bfs_sb_info *info = BFS_SB(s);
 227        u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 228        buf->f_type = BFS_MAGIC;
 229        buf->f_bsize = s->s_blocksize;
 230        buf->f_blocks = info->si_blocks;
 231        buf->f_bfree = buf->f_bavail = info->si_freeb;
 232        buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 233        buf->f_ffree = info->si_freei;
 234        buf->f_fsid.val[0] = (u32)id;
 235        buf->f_fsid.val[1] = (u32)(id >> 32);
 236        buf->f_namelen = BFS_NAMELEN;
 237        return 0;
 238}
 239
 240static struct kmem_cache *bfs_inode_cachep;
 241
 242static struct inode *bfs_alloc_inode(struct super_block *sb)
 243{
 244        struct bfs_inode_info *bi;
 245        bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 246        if (!bi)
 247                return NULL;
 248        return &bi->vfs_inode;
 249}
 250
 251static void bfs_i_callback(struct rcu_head *head)
 252{
 253        struct inode *inode = container_of(head, struct inode, i_rcu);
 254        kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 255}
 256
 257static void bfs_destroy_inode(struct inode *inode)
 258{
 259        call_rcu(&inode->i_rcu, bfs_i_callback);
 260}
 261
 262static void init_once(void *foo)
 263{
 264        struct bfs_inode_info *bi = foo;
 265
 266        inode_init_once(&bi->vfs_inode);
 267}
 268
 269static int init_inodecache(void)
 270{
 271        bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 272                                             sizeof(struct bfs_inode_info),
 273                                             0, (SLAB_RECLAIM_ACCOUNT|
 274                                                SLAB_MEM_SPREAD),
 275                                             init_once);
 276        if (bfs_inode_cachep == NULL)
 277                return -ENOMEM;
 278        return 0;
 279}
 280
 281static void destroy_inodecache(void)
 282{
 283        /*
 284         * Make sure all delayed rcu free inodes are flushed before we
 285         * destroy cache.
 286         */
 287        rcu_barrier();
 288        kmem_cache_destroy(bfs_inode_cachep);
 289}
 290
 291static const struct super_operations bfs_sops = {
 292        .alloc_inode    = bfs_alloc_inode,
 293        .destroy_inode  = bfs_destroy_inode,
 294        .write_inode    = bfs_write_inode,
 295        .evict_inode    = bfs_evict_inode,
 296        .put_super      = bfs_put_super,
 297        .statfs         = bfs_statfs,
 298};
 299
 300void dump_imap(const char *prefix, struct super_block *s)
 301{
 302#ifdef DEBUG
 303        int i;
 304        char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 305
 306        if (!tmpbuf)
 307                return;
 308        for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 309                if (i > PAGE_SIZE - 100) break;
 310                if (test_bit(i, BFS_SB(s)->si_imap))
 311                        strcat(tmpbuf, "1");
 312                else
 313                        strcat(tmpbuf, "0");
 314        }
 315        printf("BFS-fs: %s: lasti=%08lx <%s>\n",
 316                                prefix, BFS_SB(s)->si_lasti, tmpbuf);
 317        free_page((unsigned long)tmpbuf);
 318#endif
 319}
 320
 321static int bfs_fill_super(struct super_block *s, void *data, int silent)
 322{
 323        struct buffer_head *bh, *sbh;
 324        struct bfs_super_block *bfs_sb;
 325        struct inode *inode;
 326        unsigned i, imap_len;
 327        struct bfs_sb_info *info;
 328        int ret = -EINVAL;
 329        unsigned long i_sblock, i_eblock, i_eoff, s_size;
 330
 331        info = kzalloc(sizeof(*info), GFP_KERNEL);
 332        if (!info)
 333                return -ENOMEM;
 334        mutex_init(&info->bfs_lock);
 335        s->s_fs_info = info;
 336
 337        sb_set_blocksize(s, BFS_BSIZE);
 338
 339        sbh = sb_bread(s, 0);
 340        if (!sbh)
 341                goto out;
 342        bfs_sb = (struct bfs_super_block *)sbh->b_data;
 343        if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 344                if (!silent)
 345                        printf("No BFS filesystem on %s (magic=%08x)\n", 
 346                                s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 347                goto out1;
 348        }
 349        if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 350                printf("%s is unclean, continuing\n", s->s_id);
 351
 352        s->s_magic = BFS_MAGIC;
 353
 354        if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
 355                printf("Superblock is corrupted\n");
 356                goto out1;
 357        }
 358
 359        info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
 360                                        sizeof(struct bfs_inode)
 361                                        + BFS_ROOT_INO - 1;
 362        imap_len = (info->si_lasti / 8) + 1;
 363        info->si_imap = kzalloc(imap_len, GFP_KERNEL);
 364        if (!info->si_imap)
 365                goto out1;
 366        for (i = 0; i < BFS_ROOT_INO; i++)
 367                set_bit(i, info->si_imap);
 368
 369        s->s_op = &bfs_sops;
 370        inode = bfs_iget(s, BFS_ROOT_INO);
 371        if (IS_ERR(inode)) {
 372                ret = PTR_ERR(inode);
 373                goto out2;
 374        }
 375        s->s_root = d_make_root(inode);
 376        if (!s->s_root) {
 377                ret = -ENOMEM;
 378                goto out2;
 379        }
 380
 381        info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 382        info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
 383                        - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 384        info->si_freei = 0;
 385        info->si_lf_eblk = 0;
 386
 387        /* can we read the last block? */
 388        bh = sb_bread(s, info->si_blocks - 1);
 389        if (!bh) {
 390                printf("Last block not available: %lu\n", info->si_blocks - 1);
 391                ret = -EIO;
 392                goto out3;
 393        }
 394        brelse(bh);
 395
 396        bh = NULL;
 397        for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 398                struct bfs_inode *di;
 399                int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 400                int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 401                unsigned long eblock;
 402
 403                if (!off) {
 404                        brelse(bh);
 405                        bh = sb_bread(s, block);
 406                }
 407
 408                if (!bh)
 409                        continue;
 410
 411                di = (struct bfs_inode *)bh->b_data + off;
 412
 413                /* test if filesystem is not corrupted */
 414
 415                i_eoff = le32_to_cpu(di->i_eoffset);
 416                i_sblock = le32_to_cpu(di->i_sblock);
 417                i_eblock = le32_to_cpu(di->i_eblock);
 418                s_size = le32_to_cpu(bfs_sb->s_end);
 419
 420                if (i_sblock > info->si_blocks ||
 421                        i_eblock > info->si_blocks ||
 422                        i_sblock > i_eblock ||
 423                        i_eoff > s_size ||
 424                        i_sblock * BFS_BSIZE > i_eoff) {
 425
 426                        printf("Inode 0x%08x corrupted\n", i);
 427
 428                        brelse(bh);
 429                        ret = -EIO;
 430                        goto out3;
 431                }
 432
 433                if (!di->i_ino) {
 434                        info->si_freei++;
 435                        continue;
 436                }
 437                set_bit(i, info->si_imap);
 438                info->si_freeb -= BFS_FILEBLOCKS(di);
 439
 440                eblock =  le32_to_cpu(di->i_eblock);
 441                if (eblock > info->si_lf_eblk)
 442                        info->si_lf_eblk = eblock;
 443        }
 444        brelse(bh);
 445        brelse(sbh);
 446        dump_imap("read_super", s);
 447        return 0;
 448
 449out3:
 450        dput(s->s_root);
 451        s->s_root = NULL;
 452out2:
 453        kfree(info->si_imap);
 454out1:
 455        brelse(sbh);
 456out:
 457        mutex_destroy(&info->bfs_lock);
 458        kfree(info);
 459        s->s_fs_info = NULL;
 460        return ret;
 461}
 462
 463static struct dentry *bfs_mount(struct file_system_type *fs_type,
 464        int flags, const char *dev_name, void *data)
 465{
 466        return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
 467}
 468
 469static struct file_system_type bfs_fs_type = {
 470        .owner          = THIS_MODULE,
 471        .name           = "bfs",
 472        .mount          = bfs_mount,
 473        .kill_sb        = kill_block_super,
 474        .fs_flags       = FS_REQUIRES_DEV,
 475};
 476
 477static int __init init_bfs_fs(void)
 478{
 479        int err = init_inodecache();
 480        if (err)
 481                goto out1;
 482        err = register_filesystem(&bfs_fs_type);
 483        if (err)
 484                goto out;
 485        return 0;
 486out:
 487        destroy_inodecache();
 488out1:
 489        return err;
 490}
 491
 492static void __exit exit_bfs_fs(void)
 493{
 494        unregister_filesystem(&bfs_fs_type);
 495        destroy_inodecache();
 496}
 497
 498module_init(init_bfs_fs)
 499module_exit(exit_bfs_fs)
 500
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