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_set_atime(inode, le32_to_cpu(di->i_atime), 0);
  84         inode_set_mtime(inode, le32_to_cpu(di->i_mtime), 0);
  85         inode_set_ctime(inode, le32_to_cpu(di->i_ctime), 0);
  86
  87         brelse(bh);
  88         unlock_new_inode(inode);
  89         return inode;
  90
  91 error:
  92         iget_failed(inode);
  93         return ERR_PTR(-EIO);
  94 }
  95
  96 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
  97 {
  98         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
  99                 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
 100                 return ERR_PTR(-EIO);
 101         }
 102
 103         ino -= BFS_ROOT_INO;
 104
 105         *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
 106         if (!*p) {
 107                 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
 108                 return ERR_PTR(-EIO);
 109         }
 110
 111         return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
 112 }
 113
 114 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 115 {
 116         struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 117         unsigned int ino = (u16)inode->i_ino;
 118         unsigned long i_sblock;
 119         struct bfs_inode *di;
 120         struct buffer_head *bh;
 121         int err = 0;
 122
 123         dprintf("ino=%08x\n", ino);
 124
 125         di = find_inode(inode->i_sb, ino, &bh);
 126         if (IS_ERR(di))
 127                 return PTR_ERR(di);
 128
 129         mutex_lock(&info->bfs_lock);
 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(i_uid_read(inode));
 139         di->i_gid = cpu_to_le32(i_gid_read(inode));
 140         di->i_nlink = cpu_to_le32(inode->i_nlink);
 141         di->i_atime = cpu_to_le32(inode_get_atime_sec(inode));
 142         di->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode));
 143         di->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode));
 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 (wbc->sync_mode == WB_SYNC_ALL) {
 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
 160 static void bfs_evict_inode(struct inode *inode)
 161 {
 162         unsigned long ino = inode->i_ino;
 163         struct bfs_inode *di;
 164         struct buffer_head *bh;
 165         struct super_block *s = inode->i_sb;
 166         struct bfs_sb_info *info = BFS_SB(s);
 167         struct bfs_inode_info *bi = BFS_I(inode);
 168
 169         dprintf("ino=%08lx\n", ino);
 170
 171         truncate_inode_pages_final(&inode->i_data);
 172         invalidate_inode_buffers(inode);
 173         clear_inode(inode);
 174
 175         if (inode->i_nlink)
 176                 return;
 177
 178         di = find_inode(s, inode->i_ino, &bh);
 179         if (IS_ERR(di))
 180                 return;
 181
 182         mutex_lock(&info->bfs_lock);
 183         /* clear on-disk inode */
 184         memset(di, 0, sizeof(struct bfs_inode));
 185         mark_buffer_dirty(bh);
 186         brelse(bh);
 187
 188         if (bi->i_dsk_ino) {
 189                 if (bi->i_sblock)
 190                         info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
 191                 info->si_freei++;
 192                 clear_bit(ino, info->si_imap);
 193                 bfs_dump_imap("evict_inode", s);
 194         }
 195
 196         /*
 197          * If this was the last file, make the previous block
 198          * "last block of the last file" even if there is no
 199          * real file there, saves us 1 gap.
 200          */
 201         if (info->si_lf_eblk == bi->i_eblock)
 202                 info->si_lf_eblk = bi->i_sblock - 1;
 203         mutex_unlock(&info->bfs_lock);
 204 }
 205
 206 static void bfs_put_super(struct super_block *s)
 207 {
 208         struct bfs_sb_info *info = BFS_SB(s);
 209
 210         if (!info)
 211                 return;
 212
 213         mutex_destroy(&info->bfs_lock);
 214         kfree(info);
 215         s->s_fs_info = NULL;
 216 }
 217
 218 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 219 {
 220         struct super_block *s = dentry->d_sb;
 221         struct bfs_sb_info *info = BFS_SB(s);
 222         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 223         buf->f_type = BFS_MAGIC;
 224         buf->f_bsize = s->s_blocksize;
 225         buf->f_blocks = info->si_blocks;
 226         buf->f_bfree = buf->f_bavail = info->si_freeb;
 227         buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 228         buf->f_ffree = info->si_freei;
 229         buf->f_fsid = u64_to_fsid(id);
 230         buf->f_namelen = BFS_NAMELEN;
 231         return 0;
 232 }
 233
 234 static struct kmem_cache *bfs_inode_cachep;
 235
 236 static struct inode *bfs_alloc_inode(struct super_block *sb)
 237 {
 238         struct bfs_inode_info *bi;
 239         bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL);
 240         if (!bi)
 241                 return NULL;
 242         return &bi->vfs_inode;
 243 }
 244
 245 static void bfs_free_inode(struct inode *inode)
 246 {
 247         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 248 }
 249
 250 static void init_once(void *foo)
 251 {
 252         struct bfs_inode_info *bi = foo;
 253
 254         inode_init_once(&bi->vfs_inode);
 255 }
 256
 257 static int __init init_inodecache(void)
 258 {
 259         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 260                                              sizeof(struct bfs_inode_info),
 261                                              0, (SLAB_RECLAIM_ACCOUNT|
 262                                                 SLAB_ACCOUNT),
 263                                              init_once);
 264         if (bfs_inode_cachep == NULL)
 265                 return -ENOMEM;
 266         return 0;
 267 }
 268
 269 static void destroy_inodecache(void)
 270 {
 271         /*
 272          * Make sure all delayed rcu free inodes are flushed before we
 273          * destroy cache.
 274          */
 275         rcu_barrier();
 276         kmem_cache_destroy(bfs_inode_cachep);
 277 }
 278
 279 static const struct super_operations bfs_sops = {
 280         .alloc_inode    = bfs_alloc_inode,
 281         .free_inode     = bfs_free_inode,
 282         .write_inode    = bfs_write_inode,
 283         .evict_inode    = bfs_evict_inode,
 284         .put_super      = bfs_put_super,
 285         .statfs         = bfs_statfs,
 286 };
 287
 288 void bfs_dump_imap(const char *prefix, struct super_block *s)
 289 {
 290 #ifdef DEBUG
 291         int i;
 292         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 293
 294         if (!tmpbuf)
 295                 return;
 296         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 297                 if (i > PAGE_SIZE - 100) break;
 298                 if (test_bit(i, BFS_SB(s)->si_imap))
 299                         strcat(tmpbuf, "1");
 300                 else
 301                         strcat(tmpbuf, "0");
 302         }
 303         printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
 304         free_page((unsigned long)tmpbuf);
 305 #endif
 306 }
 307
 308 static int bfs_fill_super(struct super_block *s, void *data, int silent)
 309 {
 310         struct buffer_head *bh, *sbh;
 311         struct bfs_super_block *bfs_sb;
 312         struct inode *inode;
 313         unsigned i;
 314         struct bfs_sb_info *info;
 315         int ret = -EINVAL;
 316         unsigned long i_sblock, i_eblock, i_eoff, s_size;
 317
 318         info = kzalloc(sizeof(*info), GFP_KERNEL);
 319         if (!info)
 320                 return -ENOMEM;
 321         mutex_init(&info->bfs_lock);
 322         s->s_fs_info = info;
 323         s->s_time_min = 0;
 324         s->s_time_max = U32_MAX;
 325
 326         sb_set_blocksize(s, BFS_BSIZE);
 327
 328         sbh = sb_bread(s, 0);
 329         if (!sbh)
 330                 goto out;
 331         bfs_sb = (struct bfs_super_block *)sbh->b_data;
 332         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 333                 if (!silent)
 334                         printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 335                 goto out1;
 336         }
 337         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 338                 printf("%s is unclean, continuing\n", s->s_id);
 339
 340         s->s_magic = BFS_MAGIC;
 341
 342         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
 343             le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
 344                 printf("Superblock is corrupted on %s\n", s->s_id);
 345                 goto out1;
 346         }
 347
 348         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
 349         if (info->si_lasti == BFS_MAX_LASTI)
 350                 printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
 351         else if (info->si_lasti > BFS_MAX_LASTI) {
 352                 printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
 353                 goto out1;
 354         }
 355         for (i = 0; i < BFS_ROOT_INO; i++)
 356                 set_bit(i, info->si_imap);
 357
 358         s->s_op = &bfs_sops;
 359         inode = bfs_iget(s, BFS_ROOT_INO);
 360         if (IS_ERR(inode)) {
 361                 ret = PTR_ERR(inode);
 362                 goto out1;
 363         }
 364         s->s_root = d_make_root(inode);
 365         if (!s->s_root) {
 366                 ret = -ENOMEM;
 367                 goto out1;
 368         }
 369
 370         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 371         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 372         info->si_freei = 0;
 373         info->si_lf_eblk = 0;
 374
 375         /* can we read the last block? */
 376         bh = sb_bread(s, info->si_blocks - 1);
 377         if (!bh) {
 378                 printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
 379                 ret = -EIO;
 380                 goto out2;
 381         }
 382         brelse(bh);
 383
 384         bh = NULL;
 385         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 386                 struct bfs_inode *di;
 387                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 388                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 389                 unsigned long eblock;
 390
 391                 if (!off) {
 392                         brelse(bh);
 393                         bh = sb_bread(s, block);
 394                 }
 395
 396                 if (!bh)
 397                         continue;
 398
 399                 di = (struct bfs_inode *)bh->b_data + off;
 400
 401                 /* test if filesystem is not corrupted */
 402
 403                 i_eoff = le32_to_cpu(di->i_eoffset);
 404                 i_sblock = le32_to_cpu(di->i_sblock);
 405                 i_eblock = le32_to_cpu(di->i_eblock);
 406                 s_size = le32_to_cpu(bfs_sb->s_end);
 407
 408                 if (i_sblock > info->si_blocks ||
 409                         i_eblock > info->si_blocks ||
 410                         i_sblock > i_eblock ||
 411                         (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
 412                         i_sblock * BFS_BSIZE > i_eoff) {
 413
 414                         printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);
 415
 416                         brelse(bh);
 417                         ret = -EIO;
 418                         goto out2;
 419                 }
 420
 421                 if (!di->i_ino) {
 422                         info->si_freei++;
 423                         continue;
 424                 }
 425                 set_bit(i, info->si_imap);
 426                 info->si_freeb -= BFS_FILEBLOCKS(di);
 427
 428                 eblock =  le32_to_cpu(di->i_eblock);
 429                 if (eblock > info->si_lf_eblk)
 430                         info->si_lf_eblk = eblock;
 431         }
 432         brelse(bh);
 433         brelse(sbh);
 434         bfs_dump_imap("fill_super", s);
 435         return 0;
 436
 437 out2:
 438         dput(s->s_root);
 439         s->s_root = NULL;
 440 out1:
 441         brelse(sbh);
 442 out:
 443         mutex_destroy(&info->bfs_lock);
 444         kfree(info);
 445         s->s_fs_info = NULL;
 446         return ret;
 447 }
 448
 449 static struct dentry *bfs_mount(struct file_system_type *fs_type,
 450         int flags, const char *dev_name, void *data)
 451 {
 452         return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
 453 }
 454
 455 static struct file_system_type bfs_fs_type = {
 456         .owner          = THIS_MODULE,
 457         .name           = "bfs",
 458         .mount          = bfs_mount,
 459         .kill_sb        = kill_block_super,
 460         .fs_flags       = FS_REQUIRES_DEV,
 461 };
 462 MODULE_ALIAS_FS("bfs");
 463
 464 static int __init init_bfs_fs(void)
 465 {
 466         int err = init_inodecache();
 467         if (err)
 468                 goto out1;
 469         err = register_filesystem(&bfs_fs_type);
 470         if (err)
 471                 goto out;
 472         return 0;
 473 out:
 474         destroy_inodecache();
 475 out1:
 476         return err;
 477 }
 478
 479 static void __exit exit_bfs_fs(void)
 480 {
 481         unregister_filesystem(&bfs_fs_type);
 482         destroy_inodecache();
 483 }
 484
 485 module_init(init_bfs_fs)
 486 module_exit(exit_bfs_fs)