fs/bfs/inode.c

   1 /*
   2  *      fs/bfs/inode.c
   3  *      BFS superblock and inode operations.
   4  *      Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>
   5  *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
   6  *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/mm.h>
  11 #include <linux/slab.h>
  12 #include <linux/init.h>
  13 #include <linux/fs.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/vfs.h>
  16 #include <linux/writeback.h>
  17 #include <linux/uio.h>
  18 #include <linux/uaccess.h>
  19 #include "bfs.h"
  20
  21 MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>");
  22 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
  23 MODULE_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
  33 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
  34 {
  35         struct bfs_inode *di;
  36         struct inode *inode;
  37         struct buffer_head *bh;
  38         int block, off;
  39
  40         inode = iget_locked(sb, ino);
  41         if (!inode)
  42                 return ERR_PTR(-ENOMEM);
  43         if (!(inode->i_state & I_NEW))
  44                 return inode;
  45
  46         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
  47                 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
  48                 goto error;
  49         }
  50
  51         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
  52         bh = sb_bread(inode->i_sb, block);
  53         if (!bh) {
  54                 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
  55                                                                         ino);
  56                 goto error;
  57         }
  58
  59         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
  60         di = (struct bfs_inode *)bh->b_data + off;
  61
  62         inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
  63         if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
  64                 inode->i_mode |= S_IFDIR;
  65                 inode->i_op = &bfs_dir_inops;
  66                 inode->i_fop = &bfs_dir_operations;
  67         } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
  68                 inode->i_mode |= S_IFREG;
  69                 inode->i_op = &bfs_file_inops;
  70                 inode->i_fop = &bfs_file_operations;
  71                 inode->i_mapping->a_ops = &bfs_aops;
  72         }
  73
  74         BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
  75         BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
  76         BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
  77         i_uid_write(inode, le32_to_cpu(di->i_uid));
  78         i_gid_write(inode,  le32_to_cpu(di->i_gid));
  79         set_nlink(inode, le32_to_cpu(di->i_nlink));
  80         inode->i_size = BFS_FILESIZE(di);
  81         inode->i_blocks = BFS_FILEBLOCKS(di);
  82         inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
  83         inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
  84         inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
  85         inode->i_atime.tv_nsec = 0;
  86         inode->i_mtime.tv_nsec = 0;
  87         inode->i_ctime.tv_nsec = 0;
  88
  89         brelse(bh);
  90         unlock_new_inode(inode);
  91         return inode;
  92
  93 error:
  94         iget_failed(inode);
  95         return ERR_PTR(-EIO);
  96 }
  97
  98 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
  99 {
 100         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
 101                 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
 102                 return ERR_PTR(-EIO);
 103         }
 104
 105         ino -= BFS_ROOT_INO;
 106
 107         *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
 108         if (!*p) {
 109                 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
 110                 return ERR_PTR(-EIO);
 111         }
 112
 113         return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
 114 }
 115
 116 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 117 {
 118         struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 119         unsigned int ino = (u16)inode->i_ino;
 120         unsigned long i_sblock;
 121         struct bfs_inode *di;
 122         struct buffer_head *bh;
 123         int err = 0;
 124
 125         dprintf("ino=%08x\n", ino);
 126
 127         di = find_inode(inode->i_sb, ino, &bh);
 128         if (IS_ERR(di))
 129                 return PTR_ERR(di);
 130
 131         mutex_lock(&info->bfs_lock);
 132
 133         if (ino == BFS_ROOT_INO)
 134                 di->i_vtype = cpu_to_le32(BFS_VDIR);
 135         else
 136                 di->i_vtype = cpu_to_le32(BFS_VREG);
 137
 138         di->i_ino = cpu_to_le16(ino);
 139         di->i_mode = cpu_to_le32(inode->i_mode);
 140         di->i_uid = cpu_to_le32(i_uid_read(inode));
 141         di->i_gid = cpu_to_le32(i_gid_read(inode));
 142         di->i_nlink = cpu_to_le32(inode->i_nlink);
 143         di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 144         di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 145         di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 146         i_sblock = BFS_I(inode)->i_sblock;
 147         di->i_sblock = cpu_to_le32(i_sblock);
 148         di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 149         di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 150
 151         mark_buffer_dirty(bh);
 152         if (wbc->sync_mode == WB_SYNC_ALL) {
 153                 sync_dirty_buffer(bh);
 154                 if (buffer_req(bh) && !buffer_uptodate(bh))
 155                         err = -EIO;
 156         }
 157         brelse(bh);
 158         mutex_unlock(&info->bfs_lock);
 159         return err;
 160 }
 161
 162 static void bfs_evict_inode(struct inode *inode)
 163 {
 164         unsigned long ino = inode->i_ino;
 165         struct bfs_inode *di;
 166         struct buffer_head *bh;
 167         struct super_block *s = inode->i_sb;
 168         struct bfs_sb_info *info = BFS_SB(s);
 169         struct bfs_inode_info *bi = BFS_I(inode);
 170
 171         dprintf("ino=%08lx\n", ino);
 172
 173         truncate_inode_pages_final(&inode->i_data);
 174         invalidate_inode_buffers(inode);
 175         clear_inode(inode);
 176
 177         if (inode->i_nlink)
 178                 return;
 179
 180         di = find_inode(s, inode->i_ino, &bh);
 181         if (IS_ERR(di))
 182                 return;
 183
 184         mutex_lock(&info->bfs_lock);
 185         /* clear on-disk inode */
 186         memset(di, 0, sizeof(struct bfs_inode));
 187         mark_buffer_dirty(bh);
 188         brelse(bh);
 189
 190         if (bi->i_dsk_ino) {
 191                 if (bi->i_sblock)
 192                         info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
 193                 info->si_freei++;
 194                 clear_bit(ino, info->si_imap);
 195                 bfs_dump_imap("evict_inode", s);
 196         }
 197
 198         /*
 199          * If this was the last file, make the previous block
 200          * "last block of the last file" even if there is no
 201          * real file there, saves us 1 gap.
 202          */
 203         if (info->si_lf_eblk == bi->i_eblock)
 204                 info->si_lf_eblk = bi->i_sblock - 1;
 205         mutex_unlock(&info->bfs_lock);
 206 }
 207
 208 static void bfs_put_super(struct super_block *s)
 209 {
 210         struct bfs_sb_info *info = BFS_SB(s);
 211
 212         if (!info)
 213                 return;
 214
 215         mutex_destroy(&info->bfs_lock);
 216         kfree(info);
 217         s->s_fs_info = NULL;
 218 }
 219
 220 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 221 {
 222         struct super_block *s = dentry->d_sb;
 223         struct bfs_sb_info *info = BFS_SB(s);
 224         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 225         buf->f_type = BFS_MAGIC;
 226         buf->f_bsize = s->s_blocksize;
 227         buf->f_blocks = info->si_blocks;
 228         buf->f_bfree = buf->f_bavail = info->si_freeb;
 229         buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 230         buf->f_ffree = info->si_freei;
 231         buf->f_fsid.val[0] = (u32)id;
 232         buf->f_fsid.val[1] = (u32)(id >> 32);
 233         buf->f_namelen = BFS_NAMELEN;
 234         return 0;
 235 }
 236
 237 static struct kmem_cache *bfs_inode_cachep;
 238
 239 static struct inode *bfs_alloc_inode(struct super_block *sb)
 240 {
 241         struct bfs_inode_info *bi;
 242         bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 243         if (!bi)
 244                 return NULL;
 245         return &bi->vfs_inode;
 246 }
 247
 248 static void bfs_i_callback(struct rcu_head *head)
 249 {
 250         struct inode *inode = container_of(head, struct inode, i_rcu);
 251         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 252 }
 253
 254 static void bfs_destroy_inode(struct inode *inode)
 255 {
 256         call_rcu(&inode->i_rcu, bfs_i_callback);
 257 }
 258
 259 static void init_once(void *foo)
 260 {
 261         struct bfs_inode_info *bi = foo;
 262
 263         inode_init_once(&bi->vfs_inode);
 264 }
 265
 266 static int __init init_inodecache(void)
 267 {
 268         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 269                                              sizeof(struct bfs_inode_info),
 270                                              0, (SLAB_RECLAIM_ACCOUNT|
 271                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 272                                              init_once);
 273         if (bfs_inode_cachep == NULL)
 274                 return -ENOMEM;
 275         return 0;
 276 }
 277
 278 static void destroy_inodecache(void)
 279 {
 280         /*
 281          * Make sure all delayed rcu free inodes are flushed before we
 282          * destroy cache.
 283          */
 284         rcu_barrier();
 285         kmem_cache_destroy(bfs_inode_cachep);
 286 }
 287
 288 static const struct super_operations bfs_sops = {
 289         .alloc_inode    = bfs_alloc_inode,
 290         .destroy_inode  = bfs_destroy_inode,
 291         .write_inode    = bfs_write_inode,
 292         .evict_inode    = bfs_evict_inode,
 293         .put_super      = bfs_put_super,
 294         .statfs         = bfs_statfs,
 295 };
 296
 297 void bfs_dump_imap(const char *prefix, struct super_block *s)
 298 {
 299 #ifdef DEBUG
 300         int i;
 301         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 302
 303         if (!tmpbuf)
 304                 return;
 305         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 306                 if (i > PAGE_SIZE - 100) break;
 307                 if (test_bit(i, BFS_SB(s)->si_imap))
 308                         strcat(tmpbuf, "1");
 309                 else
 310                         strcat(tmpbuf, "0");
 311         }
 312         printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
 313         free_page((unsigned long)tmpbuf);
 314 #endif
 315 }
 316
 317 static int bfs_fill_super(struct super_block *s, void *data, int silent)
 318 {
 319         struct buffer_head *bh, *sbh;
 320         struct bfs_super_block *bfs_sb;
 321         struct inode *inode;
 322         unsigned i;
 323         struct bfs_sb_info *info;
 324         int ret = -EINVAL;
 325         unsigned long i_sblock, i_eblock, i_eoff, s_size;
 326
 327         info = kzalloc(sizeof(*info), GFP_KERNEL);
 328         if (!info)
 329                 return -ENOMEM;
 330         mutex_init(&info->bfs_lock);
 331         s->s_fs_info = info;
 332
 333         sb_set_blocksize(s, BFS_BSIZE);
 334
 335         sbh = sb_bread(s, 0);
 336         if (!sbh)
 337                 goto out;
 338         bfs_sb = (struct bfs_super_block *)sbh->b_data;
 339         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 340                 if (!silent)
 341                         printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 342                 goto out1;
 343         }
 344         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 345                 printf("%s is unclean, continuing\n", s->s_id);
 346
 347         s->s_magic = BFS_MAGIC;
 348
 349         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
 350             le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
 351                 printf("Superblock is corrupted on %s\n", s->s_id);
 352                 goto out1;
 353         }
 354
 355         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
 356         if (info->si_lasti == BFS_MAX_LASTI)
 357                 printf("WARNING: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
 358         else if (info->si_lasti > BFS_MAX_LASTI) {
 359                 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
 360                 goto out1;
 361         }
 362         for (i = 0; i < BFS_ROOT_INO; i++)
 363                 set_bit(i, info->si_imap);
 364
 365         s->s_op = &bfs_sops;
 366         inode = bfs_iget(s, BFS_ROOT_INO);
 367         if (IS_ERR(inode)) {
 368                 ret = PTR_ERR(inode);
 369                 goto out1;
 370         }
 371         s->s_root = d_make_root(inode);
 372         if (!s->s_root) {
 373                 ret = -ENOMEM;
 374                 goto out1;
 375         }
 376
 377         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 378         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 379         info->si_freei = 0;
 380         info->si_lf_eblk = 0;
 381
 382         /* can we read the last block? */
 383         bh = sb_bread(s, info->si_blocks - 1);
 384         if (!bh) {
 385                 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
 386                 ret = -EIO;
 387                 goto out2;
 388         }
 389         brelse(bh);
 390
 391         bh = NULL;
 392         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 393                 struct bfs_inode *di;
 394                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 395                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 396                 unsigned long eblock;
 397
 398                 if (!off) {
 399                         brelse(bh);
 400                         bh = sb_bread(s, block);
 401                 }
 402
 403                 if (!bh)
 404                         continue;
 405
 406                 di = (struct bfs_inode *)bh->b_data + off;
 407
 408                 /* test if filesystem is not corrupted */
 409
 410                 i_eoff = le32_to_cpu(di->i_eoffset);
 411                 i_sblock = le32_to_cpu(di->i_sblock);
 412                 i_eblock = le32_to_cpu(di->i_eblock);
 413                 s_size = le32_to_cpu(bfs_sb->s_end);
 414
 415                 if (i_sblock > info->si_blocks ||
 416                         i_eblock > info->si_blocks ||
 417                         i_sblock > i_eblock ||
 418                         (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
 419                         i_sblock * BFS_BSIZE > i_eoff) {
 420
 421                         printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
 422
 423                         brelse(bh);
 424                         ret = -EIO;
 425                         goto out2;
 426                 }
 427
 428                 if (!di->i_ino) {
 429                         info->si_freei++;
 430                         continue;
 431                 }
 432                 set_bit(i, info->si_imap);
 433                 info->si_freeb -= BFS_FILEBLOCKS(di);
 434
 435                 eblock =  le32_to_cpu(di->i_eblock);
 436                 if (eblock > info->si_lf_eblk)
 437                         info->si_lf_eblk = eblock;
 438         }
 439         brelse(bh);
 440         brelse(sbh);
 441         bfs_dump_imap("fill_super", s);
 442         return 0;
 443
 444 out2:
 445         dput(s->s_root);
 446         s->s_root = NULL;
 447 out1:
 448         brelse(sbh);
 449 out:
 450         mutex_destroy(&info->bfs_lock);
 451         kfree(info);
 452         s->s_fs_info = NULL;
 453         return ret;
 454 }
 455
 456 static struct dentry *bfs_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, bfs_fill_super);
 460 }
 461
 462 static struct file_system_type bfs_fs_type = {
 463         .owner          = THIS_MODULE,
 464         .name           = "bfs",
 465         .mount          = bfs_mount,
 466         .kill_sb        = kill_block_super,
 467         .fs_flags       = FS_REQUIRES_DEV,
 468 };
 469 MODULE_ALIAS_FS("bfs");
 470
 471 static int __init init_bfs_fs(void)
 472 {
 473         int err = init_inodecache();
 474         if (err)
 475                 goto out1;
 476         err = register_filesystem(&bfs_fs_type);
 477         if (err)
 478                 goto out;
 479         return 0;
 480 out:
 481         destroy_inodecache();
 482 out1:
 483         return err;
 484 }
 485
 486 static void __exit exit_bfs_fs(void)
 487 {
 488         unregister_filesystem(&bfs_fs_type);
 489         destroy_inodecache();
 490 }
 491
 492 module_init(init_bfs_fs)
 493 module_exit(exit_bfs_fs)