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 <aivazian.tigran@gmail.com>
   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 <linux/uio.h>
  19#include <linux/uaccess.h>
  20#include "bfs.h"
  21
  22MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>");
  23MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
  24MODULE_LICENSE("GPL");
  25
  26#undef DEBUG
  27
  28#ifdef DEBUG
  29#define dprintf(x...)   printf(x)
  30#else
  31#define dprintf(x...)
  32#endif
  33
  34struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
  35{
  36        struct bfs_inode *di;
  37        struct inode *inode;
  38        struct buffer_head *bh;
  39        int block, off;
  40
  41        inode = iget_locked(sb, ino);
  42        if (!inode)
  43                return ERR_PTR(-ENOMEM);
  44        if (!(inode->i_state & I_NEW))
  45                return inode;
  46
  47        if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
  48                printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
  49                goto error;
  50        }
  51
  52        block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
  53        bh = sb_bread(inode->i_sb, block);
  54        if (!bh) {
  55                printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
  56                                                                        ino);
  57                goto error;
  58        }
  59
  60        off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
  61        di = (struct bfs_inode *)bh->b_data + off;
  62
  63        inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
  64        if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
  65                inode->i_mode |= S_IFDIR;
  66                inode->i_op = &bfs_dir_inops;
  67                inode->i_fop = &bfs_dir_operations;
  68        } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
  69                inode->i_mode |= S_IFREG;
  70                inode->i_op = &bfs_file_inops;
  71                inode->i_fop = &bfs_file_operations;
  72                inode->i_mapping->a_ops = &bfs_aops;
  73        }
  74
  75        BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
  76        BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
  77        BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
  78        i_uid_write(inode, le32_to_cpu(di->i_uid));
  79        i_gid_write(inode,  le32_to_cpu(di->i_gid));
  80        set_nlink(inode, le32_to_cpu(di->i_nlink));
  81        inode->i_size = BFS_FILESIZE(di);
  82        inode->i_blocks = BFS_FILEBLOCKS(di);
  83        inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
  84        inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
  85        inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
  86        inode->i_atime.tv_nsec = 0;
  87        inode->i_mtime.tv_nsec = 0;
  88        inode->i_ctime.tv_nsec = 0;
  89
  90        brelse(bh);
  91        unlock_new_inode(inode);
  92        return inode;
  93
  94error:
  95        iget_failed(inode);
  96        return ERR_PTR(-EIO);
  97}
  98
  99static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
 100{
 101        if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
 102                printf("Bad inode number %s:%08x\n", sb->s_id, ino);
 103                return ERR_PTR(-EIO);
 104        }
 105
 106        ino -= BFS_ROOT_INO;
 107
 108        *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
 109        if (!*p) {
 110                printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
 111                return ERR_PTR(-EIO);
 112        }
 113
 114        return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
 115}
 116
 117static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 118{
 119        struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 120        unsigned int ino = (u16)inode->i_ino;
 121        unsigned long i_sblock;
 122        struct bfs_inode *di;
 123        struct buffer_head *bh;
 124        int err = 0;
 125
 126        dprintf("ino=%08x\n", ino);
 127
 128        di = find_inode(inode->i_sb, ino, &bh);
 129        if (IS_ERR(di))
 130                return PTR_ERR(di);
 131
 132        mutex_lock(&info->bfs_lock);
 133
 134        if (ino == BFS_ROOT_INO)
 135                di->i_vtype = cpu_to_le32(BFS_VDIR);
 136        else
 137                di->i_vtype = cpu_to_le32(BFS_VREG);
 138
 139        di->i_ino = cpu_to_le16(ino);
 140        di->i_mode = cpu_to_le32(inode->i_mode);
 141        di->i_uid = cpu_to_le32(i_uid_read(inode));
 142        di->i_gid = cpu_to_le32(i_gid_read(inode));
 143        di->i_nlink = cpu_to_le32(inode->i_nlink);
 144        di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 145        di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 146        di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 147        i_sblock = BFS_I(inode)->i_sblock;
 148        di->i_sblock = cpu_to_le32(i_sblock);
 149        di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 150        di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 151
 152        mark_buffer_dirty(bh);
 153        if (wbc->sync_mode == WB_SYNC_ALL) {
 154                sync_dirty_buffer(bh);
 155                if (buffer_req(bh) && !buffer_uptodate(bh))
 156                        err = -EIO;
 157        }
 158        brelse(bh);
 159        mutex_unlock(&info->bfs_lock);
 160        return err;
 161}
 162
 163static void bfs_evict_inode(struct inode *inode)
 164{
 165        unsigned long ino = inode->i_ino;
 166        struct bfs_inode *di;
 167        struct buffer_head *bh;
 168        struct super_block *s = inode->i_sb;
 169        struct bfs_sb_info *info = BFS_SB(s);
 170        struct bfs_inode_info *bi = BFS_I(inode);
 171
 172        dprintf("ino=%08lx\n", ino);
 173
 174        truncate_inode_pages_final(&inode->i_data);
 175        invalidate_inode_buffers(inode);
 176        clear_inode(inode);
 177
 178        if (inode->i_nlink)
 179                return;
 180
 181        di = find_inode(s, inode->i_ino, &bh);
 182        if (IS_ERR(di))
 183                return;
 184
 185        mutex_lock(&info->bfs_lock);
 186        /* clear on-disk inode */
 187        memset(di, 0, sizeof(struct bfs_inode));
 188        mark_buffer_dirty(bh);
 189        brelse(bh);
 190
 191        if (bi->i_dsk_ino) {
 192                if (bi->i_sblock)
 193                        info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
 194                info->si_freei++;
 195                clear_bit(ino, info->si_imap);
 196                bfs_dump_imap("delete_inode", s);
 197        }
 198
 199        /*
 200         * If this was the last file, make the previous block
 201         * "last block of the last file" even if there is no
 202         * real file there, saves us 1 gap.
 203         */
 204        if (info->si_lf_eblk == bi->i_eblock)
 205                info->si_lf_eblk = bi->i_sblock - 1;
 206        mutex_unlock(&info->bfs_lock);
 207}
 208
 209static void bfs_put_super(struct super_block *s)
 210{
 211        struct bfs_sb_info *info = BFS_SB(s);
 212
 213        if (!info)
 214                return;
 215
 216        mutex_destroy(&info->bfs_lock);
 217        kfree(info->si_imap);
 218        kfree(info);
 219        s->s_fs_info = NULL;
 220}
 221
 222static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 223{
 224        struct super_block *s = dentry->d_sb;
 225        struct bfs_sb_info *info = BFS_SB(s);
 226        u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 227        buf->f_type = BFS_MAGIC;
 228        buf->f_bsize = s->s_blocksize;
 229        buf->f_blocks = info->si_blocks;
 230        buf->f_bfree = buf->f_bavail = info->si_freeb;
 231        buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 232        buf->f_ffree = info->si_freei;
 233        buf->f_fsid.val[0] = (u32)id;
 234        buf->f_fsid.val[1] = (u32)(id >> 32);
 235        buf->f_namelen = BFS_NAMELEN;
 236        return 0;
 237}
 238
 239static struct kmem_cache *bfs_inode_cachep;
 240
 241static struct inode *bfs_alloc_inode(struct super_block *sb)
 242{
 243        struct bfs_inode_info *bi;
 244        bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 245        if (!bi)
 246                return NULL;
 247        return &bi->vfs_inode;
 248}
 249
 250static void bfs_i_callback(struct rcu_head *head)
 251{
 252        struct inode *inode = container_of(head, struct inode, i_rcu);
 253        kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 254}
 255
 256static void bfs_destroy_inode(struct inode *inode)
 257{
 258        call_rcu(&inode->i_rcu, bfs_i_callback);
 259}
 260
 261static void init_once(void *foo)
 262{
 263        struct bfs_inode_info *bi = foo;
 264
 265        inode_init_once(&bi->vfs_inode);
 266}
 267
 268static int __init init_inodecache(void)
 269{
 270        bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 271                                             sizeof(struct bfs_inode_info),
 272                                             0, (SLAB_RECLAIM_ACCOUNT|
 273                                                SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 274                                             init_once);
 275        if (bfs_inode_cachep == NULL)
 276                return -ENOMEM;
 277        return 0;
 278}
 279
 280static void destroy_inodecache(void)
 281{
 282        /*
 283         * Make sure all delayed rcu free inodes are flushed before we
 284         * destroy cache.
 285         */
 286        rcu_barrier();
 287        kmem_cache_destroy(bfs_inode_cachep);
 288}
 289
 290static const struct super_operations bfs_sops = {
 291        .alloc_inode    = bfs_alloc_inode,
 292        .destroy_inode  = bfs_destroy_inode,
 293        .write_inode    = bfs_write_inode,
 294        .evict_inode    = bfs_evict_inode,
 295        .put_super      = bfs_put_super,
 296        .statfs         = bfs_statfs,
 297};
 298
 299void bfs_dump_imap(const char *prefix, struct super_block *s)
 300{
 301#ifdef DEBUG
 302        int i;
 303        char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 304
 305        if (!tmpbuf)
 306                return;
 307        for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 308                if (i > PAGE_SIZE - 100) break;
 309                if (test_bit(i, BFS_SB(s)->si_imap))
 310                        strcat(tmpbuf, "1");
 311                else
 312                        strcat(tmpbuf, "0");
 313        }
 314        printf("BFS-fs: %s: lasti=%08lx <%s>\n",
 315                                prefix, BFS_SB(s)->si_lasti, tmpbuf);
 316        free_page((unsigned long)tmpbuf);
 317#endif
 318}
 319
 320static int bfs_fill_super(struct super_block *s, void *data, int silent)
 321{
 322        struct buffer_head *bh, *sbh;
 323        struct bfs_super_block *bfs_sb;
 324        struct inode *inode;
 325        unsigned i, imap_len;
 326        struct bfs_sb_info *info;
 327        int ret = -EINVAL;
 328        unsigned long i_sblock, i_eblock, i_eoff, s_size;
 329
 330        info = kzalloc(sizeof(*info), GFP_KERNEL);
 331        if (!info)
 332                return -ENOMEM;
 333        mutex_init(&info->bfs_lock);
 334        s->s_fs_info = info;
 335
 336        sb_set_blocksize(s, BFS_BSIZE);
 337
 338        sbh = sb_bread(s, 0);
 339        if (!sbh)
 340                goto out;
 341        bfs_sb = (struct bfs_super_block *)sbh->b_data;
 342        if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 343                if (!silent)
 344                        printf("No BFS filesystem on %s (magic=%08x)\n", 
 345                                s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 346                goto out1;
 347        }
 348        if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 349                printf("%s is unclean, continuing\n", s->s_id);
 350
 351        s->s_magic = BFS_MAGIC;
 352
 353        if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
 354                printf("Superblock is corrupted\n");
 355                goto out1;
 356        }
 357
 358        info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
 359                                        sizeof(struct bfs_inode)
 360                                        + BFS_ROOT_INO - 1;
 361        imap_len = (info->si_lasti / 8) + 1;
 362        info->si_imap = kzalloc(imap_len, GFP_KERNEL);
 363        if (!info->si_imap)
 364                goto out1;
 365        for (i = 0; i < BFS_ROOT_INO; i++)
 366                set_bit(i, info->si_imap);
 367
 368        s->s_op = &bfs_sops;
 369        inode = bfs_iget(s, BFS_ROOT_INO);
 370        if (IS_ERR(inode)) {
 371                ret = PTR_ERR(inode);
 372                goto out2;
 373        }
 374        s->s_root = d_make_root(inode);
 375        if (!s->s_root) {
 376                ret = -ENOMEM;
 377                goto out2;
 378        }
 379
 380        info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 381        info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
 382                        - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 383        info->si_freei = 0;
 384        info->si_lf_eblk = 0;
 385
 386        /* can we read the last block? */
 387        bh = sb_bread(s, info->si_blocks - 1);
 388        if (!bh) {
 389                printf("Last block not available: %lu\n", info->si_blocks - 1);
 390                ret = -EIO;
 391                goto out3;
 392        }
 393        brelse(bh);
 394
 395        bh = NULL;
 396        for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 397                struct bfs_inode *di;
 398                int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 399                int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 400                unsigned long eblock;
 401
 402                if (!off) {
 403                        brelse(bh);
 404                        bh = sb_bread(s, block);
 405                }
 406
 407                if (!bh)
 408                        continue;
 409
 410                di = (struct bfs_inode *)bh->b_data + off;
 411
 412                /* test if filesystem is not corrupted */
 413
 414                i_eoff = le32_to_cpu(di->i_eoffset);
 415                i_sblock = le32_to_cpu(di->i_sblock);
 416                i_eblock = le32_to_cpu(di->i_eblock);
 417                s_size = le32_to_cpu(bfs_sb->s_end);
 418
 419                if (i_sblock > info->si_blocks ||
 420                        i_eblock > info->si_blocks ||
 421                        i_sblock > i_eblock ||
 422                        (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
 423                        i_sblock * BFS_BSIZE > i_eoff) {
 424
 425                        printf("Inode 0x%08x corrupted\n", i);
 426
 427                        brelse(bh);
 428                        ret = -EIO;
 429                        goto out3;
 430                }
 431
 432                if (!di->i_ino) {
 433                        info->si_freei++;
 434                        continue;
 435                }
 436                set_bit(i, info->si_imap);
 437                info->si_freeb -= BFS_FILEBLOCKS(di);
 438
 439                eblock =  le32_to_cpu(di->i_eblock);
 440                if (eblock > info->si_lf_eblk)
 441                        info->si_lf_eblk = eblock;
 442        }
 443        brelse(bh);
 444        brelse(sbh);
 445        bfs_dump_imap("read_super", s);
 446        return 0;
 447
 448out3:
 449        dput(s->s_root);
 450        s->s_root = NULL;
 451out2:
 452        kfree(info->si_imap);
 453out1:
 454        brelse(sbh);
 455out:
 456        mutex_destroy(&info->bfs_lock);
 457        kfree(info);
 458        s->s_fs_info = NULL;
 459        return ret;
 460}
 461
 462static struct dentry *bfs_mount(struct file_system_type *fs_type,
 463        int flags, const char *dev_name, void *data)
 464{
 465        return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
 466}
 467
 468static struct file_system_type bfs_fs_type = {
 469        .owner          = THIS_MODULE,
 470        .name           = "bfs",
 471        .mount          = bfs_mount,
 472        .kill_sb        = kill_block_super,
 473        .fs_flags       = FS_REQUIRES_DEV,
 474};
 475MODULE_ALIAS_FS("bfs");
 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