fs/bfs/inode.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *      fs/bfs/inode.c
   4  *      BFS superblock and inode operations.
   5  *      Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>
   6  *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
   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
  22 MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>");
  23 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
  24 MODULE_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
  34 struct 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
  94 error:
  95         iget_failed(inode);
  96         return ERR_PTR(-EIO);
  97 }
  98
  99 static 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
 117 static 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
 163 static 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("evict_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
 209 static 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);
 218         s->s_fs_info = NULL;
 219 }
 220
 221 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 222 {
 223         struct super_block *s = dentry->d_sb;
 224         struct bfs_sb_info *info = BFS_SB(s);
 225         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 226         buf->f_type = BFS_MAGIC;
 227         buf->f_bsize = s->s_blocksize;
 228         buf->f_blocks = info->si_blocks;
 229         buf->f_bfree = buf->f_bavail = info->si_freeb;
 230         buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 231         buf->f_ffree = info->si_freei;
 232         buf->f_fsid = u64_to_fsid(id);
 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_free_inode(struct inode *inode)
 249 {
 250         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 251 }
 252
 253 static void init_once(void *foo)
 254 {
 255         struct bfs_inode_info *bi = foo;
 256
 257         inode_init_once(&bi->vfs_inode);
 258 }
 259
 260 static int __init init_inodecache(void)
 261 {
 262         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 263                                              sizeof(struct bfs_inode_info),
 264                                              0, (SLAB_RECLAIM_ACCOUNT|
 265                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 266                                              init_once);
 267         if (bfs_inode_cachep == NULL)
 268                 return -ENOMEM;
 269         return 0;
 270 }
 271
 272 static void destroy_inodecache(void)
 273 {
 274         /*
 275          * Make sure all delayed rcu free inodes are flushed before we
 276          * destroy cache.
 277          */
 278         rcu_barrier();
 279         kmem_cache_destroy(bfs_inode_cachep);
 280 }
 281
 282 static const struct super_operations bfs_sops = {
 283         .alloc_inode    = bfs_alloc_inode,
 284         .free_inode     = bfs_free_inode,
 285         .write_inode    = bfs_write_inode,
 286         .evict_inode    = bfs_evict_inode,
 287         .put_super      = bfs_put_super,
 288         .statfs         = bfs_statfs,
 289 };
 290
 291 void bfs_dump_imap(const char *prefix, struct super_block *s)
 292 {
 293 #ifdef DEBUG
 294         int i;
 295         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 296
 297         if (!tmpbuf)
 298                 return;
 299         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 300                 if (i > PAGE_SIZE - 100) break;
 301                 if (test_bit(i, BFS_SB(s)->si_imap))
 302                         strcat(tmpbuf, "1");
 303                 else
 304                         strcat(tmpbuf, "0");
 305         }
 306         printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
 307         free_page((unsigned long)tmpbuf);
 308 #endif
 309 }
 310
 311 static int bfs_fill_super(struct super_block *s, void *data, int silent)
 312 {
 313         struct buffer_head *bh, *sbh;
 314         struct bfs_super_block *bfs_sb;
 315         struct inode *inode;
 316         unsigned i;
 317         struct bfs_sb_info *info;
 318         int ret = -EINVAL;
 319         unsigned long i_sblock, i_eblock, i_eoff, s_size;
 320
 321         info = kzalloc(sizeof(*info), GFP_KERNEL);
 322         if (!info)
 323                 return -ENOMEM;
 324         mutex_init(&info->bfs_lock);
 325         s->s_fs_info = info;
 326         s->s_time_min = 0;
 327         s->s_time_max = U32_MAX;
 328
 329         sb_set_blocksize(s, BFS_BSIZE);
 330
 331         sbh = sb_bread(s, 0);
 332         if (!sbh)
 333                 goto out;
 334         bfs_sb = (struct bfs_super_block *)sbh->b_data;
 335         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 336                 if (!silent)
 337                         printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 338                 goto out1;
 339         }
 340         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 341                 printf("%s is unclean, continuing\n", s->s_id);
 342
 343         s->s_magic = BFS_MAGIC;
 344
 345         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
 346             le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
 347                 printf("Superblock is corrupted on %s\n", s->s_id);
 348                 goto out1;
 349         }
 350
 351         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
 352         if (info->si_lasti == BFS_MAX_LASTI)
 353                 printf("WARNING: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
 354         else if (info->si_lasti > BFS_MAX_LASTI) {
 355                 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
 356                 goto out1;
 357         }
 358         for (i = 0; i < BFS_ROOT_INO; i++)
 359                 set_bit(i, info->si_imap);
 360
 361         s->s_op = &bfs_sops;
 362         inode = bfs_iget(s, BFS_ROOT_INO);
 363         if (IS_ERR(inode)) {
 364                 ret = PTR_ERR(inode);
 365                 goto out1;
 366         }
 367         s->s_root = d_make_root(inode);
 368         if (!s->s_root) {
 369                 ret = -ENOMEM;
 370                 goto out1;
 371         }
 372
 373         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 374         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 375         info->si_freei = 0;
 376         info->si_lf_eblk = 0;
 377
 378         /* can we read the last block? */
 379         bh = sb_bread(s, info->si_blocks - 1);
 380         if (!bh) {
 381                 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
 382                 ret = -EIO;
 383                 goto out2;
 384         }
 385         brelse(bh);
 386
 387         bh = NULL;
 388         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 389                 struct bfs_inode *di;
 390                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 391                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 392                 unsigned long eblock;
 393
 394                 if (!off) {
 395                         brelse(bh);
 396                         bh = sb_bread(s, block);
 397                 }
 398
 399                 if (!bh)
 400                         continue;
 401
 402                 di = (struct bfs_inode *)bh->b_data + off;
 403
 404                 /* test if filesystem is not corrupted */
 405
 406                 i_eoff = le32_to_cpu(di->i_eoffset);
 407                 i_sblock = le32_to_cpu(di->i_sblock);
 408                 i_eblock = le32_to_cpu(di->i_eblock);
 409                 s_size = le32_to_cpu(bfs_sb->s_end);
 410
 411                 if (i_sblock > info->si_blocks ||
 412                         i_eblock > info->si_blocks ||
 413                         i_sblock > i_eblock ||
 414                         (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
 415                         i_sblock * BFS_BSIZE > i_eoff) {
 416
 417                         printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
 418
 419                         brelse(bh);
 420                         ret = -EIO;
 421                         goto out2;
 422                 }
 423
 424                 if (!di->i_ino) {
 425                         info->si_freei++;
 426                         continue;
 427                 }
 428                 set_bit(i, info->si_imap);
 429                 info->si_freeb -= BFS_FILEBLOCKS(di);
 430
 431                 eblock =  le32_to_cpu(di->i_eblock);
 432                 if (eblock > info->si_lf_eblk)
 433                         info->si_lf_eblk = eblock;
 434         }
 435         brelse(bh);
 436         brelse(sbh);
 437         bfs_dump_imap("fill_super", s);
 438         return 0;
 439
 440 out2:
 441         dput(s->s_root);
 442         s->s_root = NULL;
 443 out1:
 444         brelse(sbh);
 445 out:
 446         mutex_destroy(&info->bfs_lock);
 447         kfree(info);
 448         s->s_fs_info = NULL;
 449         return ret;
 450 }
 451
 452 static struct dentry *bfs_mount(struct file_system_type *fs_type,
 453         int flags, const char *dev_name, void *data)
 454 {
 455         return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
 456 }
 457
 458 static struct file_system_type bfs_fs_type = {
 459         .owner          = THIS_MODULE,
 460         .name           = "bfs",
 461         .mount          = bfs_mount,
 462         .kill_sb        = kill_block_super,
 463         .fs_flags       = FS_REQUIRES_DEV,
 464 };
 465 MODULE_ALIAS_FS("bfs");
 466
 467 static int __init init_bfs_fs(void)
 468 {
 469         int err = init_inodecache();
 470         if (err)
 471                 goto out1;
 472         err = register_filesystem(&bfs_fs_type);
 473         if (err)
 474                 goto out;
 475         return 0;
 476 out:
 477         destroy_inodecache();
 478 out1:
 479         return err;
 480 }
 481
 482 static void __exit exit_bfs_fs(void)
 483 {
 484         unregister_filesystem(&bfs_fs_type);
 485         destroy_inodecache();
 486 }
 487
 488 module_init(init_bfs_fs)
 489 module_exit(exit_bfs_fs)