fs/bfs/inode.c

   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/smp_lock.h>
  16 #include <linux/buffer_head.h>
  17 #include <linux/vfs.h>
  18 #include <asm/uaccess.h>
  19 #include "bfs.h"
  20
  21 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
  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 void dump_imap(const char *prefix, struct super_block *s);
  34
  35 struct 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         inode->i_uid =  le32_to_cpu(di->i_uid);
  80         inode->i_gid =  le32_to_cpu(di->i_gid);
  81         inode->i_nlink =  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
  95 error:
  96         iget_failed(inode);
  97         return ERR_PTR(-EIO);
  98 }
  99
 100 static int bfs_write_inode(struct inode *inode, int unused)
 101 {
 102         unsigned int ino = (u16)inode->i_ino;
 103         unsigned long i_sblock;
 104         struct bfs_inode *di;
 105         struct buffer_head *bh;
 106         int block, off;
 107
 108         dprintf("ino=%08x\n", ino);
 109
 110         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
 111                 printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
 112                 return -EIO;
 113         }
 114
 115         lock_kernel();
 116         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 117         bh = sb_bread(inode->i_sb, block);
 118         if (!bh) {
 119                 printf("Unable to read inode %s:%08x\n",
 120                                 inode->i_sb->s_id, ino);
 121                 unlock_kernel();
 122                 return -EIO;
 123         }
 124
 125         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 126         di = (struct bfs_inode *)bh->b_data + off;
 127
 128         if (ino == BFS_ROOT_INO)
 129                 di->i_vtype = cpu_to_le32(BFS_VDIR);
 130         else
 131                 di->i_vtype = cpu_to_le32(BFS_VREG);
 132
 133         di->i_ino = cpu_to_le16(ino);
 134         di->i_mode = cpu_to_le32(inode->i_mode);
 135         di->i_uid = cpu_to_le32(inode->i_uid);
 136         di->i_gid = cpu_to_le32(inode->i_gid);
 137         di->i_nlink = cpu_to_le32(inode->i_nlink);
 138         di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 139         di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 140         di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 141         i_sblock = BFS_I(inode)->i_sblock;
 142         di->i_sblock = cpu_to_le32(i_sblock);
 143         di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 144         di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 145
 146         mark_buffer_dirty(bh);
 147         brelse(bh);
 148         unlock_kernel();
 149         return 0;
 150 }
 151
 152 static void bfs_delete_inode(struct inode *inode)
 153 {
 154         unsigned long ino = inode->i_ino;
 155         struct bfs_inode *di;
 156         struct buffer_head *bh;
 157         int block, off;
 158         struct super_block *s = inode->i_sb;
 159         struct bfs_sb_info *info = BFS_SB(s);
 160         struct bfs_inode_info *bi = BFS_I(inode);
 161
 162         dprintf("ino=%08lx\n", ino);
 163
 164         truncate_inode_pages(&inode->i_data, 0);
 165
 166         if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
 167                 printf("invalid ino=%08lx\n", ino);
 168                 return;
 169         }
 170
 171         inode->i_size = 0;
 172         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 173         lock_kernel();
 174         mark_inode_dirty(inode);
 175
 176         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 177         bh = sb_bread(s, block);
 178         if (!bh) {
 179                 printf("Unable to read inode %s:%08lx\n",
 180                                         inode->i_sb->s_id, ino);
 181                 unlock_kernel();
 182                 return;
 183         }
 184         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 185         di = (struct bfs_inode *)bh->b_data + off;
 186         memset((void *)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                 dump_imap("delete_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                 mark_buffer_dirty(info->si_sbh);
 206         }
 207         unlock_kernel();
 208         clear_inode(inode);
 209 }
 210
 211 static void bfs_put_super(struct super_block *s)
 212 {
 213         struct bfs_sb_info *info = BFS_SB(s);
 214         brelse(info->si_sbh);
 215         kfree(info->si_imap);
 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 void bfs_write_super(struct super_block *s)
 238 {
 239         lock_kernel();
 240         if (!(s->s_flags & MS_RDONLY))
 241                 mark_buffer_dirty(BFS_SB(s)->si_sbh);
 242         s->s_dirt = 0;
 243         unlock_kernel();
 244 }
 245
 246 static struct kmem_cache *bfs_inode_cachep;
 247
 248 static struct inode *bfs_alloc_inode(struct super_block *sb)
 249 {
 250         struct bfs_inode_info *bi;
 251         bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 252         if (!bi)
 253                 return NULL;
 254         return &bi->vfs_inode;
 255 }
 256
 257 static void bfs_destroy_inode(struct inode *inode)
 258 {
 259         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 260 }
 261
 262 static void init_once(struct kmem_cache *cachep, void *foo)
 263 {
 264         struct bfs_inode_info *bi = foo;
 265
 266         inode_init_once(&bi->vfs_inode);
 267 }
 268
 269 static 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
 281 static void destroy_inodecache(void)
 282 {
 283         kmem_cache_destroy(bfs_inode_cachep);
 284 }
 285
 286 static const struct super_operations bfs_sops = {
 287         .alloc_inode    = bfs_alloc_inode,
 288         .destroy_inode  = bfs_destroy_inode,
 289         .write_inode    = bfs_write_inode,
 290         .delete_inode   = bfs_delete_inode,
 291         .put_super      = bfs_put_super,
 292         .write_super    = bfs_write_super,
 293         .statfs         = bfs_statfs,
 294 };
 295
 296 void dump_imap(const char *prefix, struct super_block *s)
 297 {
 298 #ifdef DEBUG
 299         int i;
 300         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 301
 302         if (!tmpbuf)
 303                 return;
 304         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 305                 if (i > PAGE_SIZE - 100) break;
 306                 if (test_bit(i, BFS_SB(s)->si_imap))
 307                         strcat(tmpbuf, "1");
 308                 else
 309                         strcat(tmpbuf, "0");
 310         }
 311         printf("BFS-fs: %s: lasti=%08lx <%s>\n",
 312                                 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;
 320         struct bfs_super_block *bfs_sb;
 321         struct inode *inode;
 322         unsigned i, imap_len;
 323         struct bfs_sb_info *info;
 324         long ret = -EINVAL;
 325
 326         info = kzalloc(sizeof(*info), GFP_KERNEL);
 327         if (!info)
 328                 return -ENOMEM;
 329         s->s_fs_info = info;
 330
 331         sb_set_blocksize(s, BFS_BSIZE);
 332
 333         bh = sb_bread(s, 0);
 334         if(!bh)
 335                 goto out;
 336         bfs_sb = (struct bfs_super_block *)bh->b_data;
 337         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 338                 if (!silent)
 339                         printf("No BFS filesystem on %s (magic=%08x)\n",
 340                                 s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 341                 goto out;
 342         }
 343         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 344                 printf("%s is unclean, continuing\n", s->s_id);
 345
 346         s->s_magic = BFS_MAGIC;
 347         info->si_sbh = bh;
 348         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
 349                                         sizeof(struct bfs_inode)
 350                                         + BFS_ROOT_INO - 1;
 351         imap_len = (info->si_lasti / 8) + 1;
 352         info->si_imap = kzalloc(imap_len, GFP_KERNEL);
 353         if (!info->si_imap)
 354                 goto out;
 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                 kfree(info->si_imap);
 363                 goto out;
 364         }
 365         s->s_root = d_alloc_root(inode);
 366         if (!s->s_root) {
 367                 iput(inode);
 368                 ret = -ENOMEM;
 369                 kfree(info->si_imap);
 370                 goto out;
 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
 375                         - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 376         info->si_freei = 0;
 377         info->si_lf_eblk = 0;
 378         bh = NULL;
 379         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 380                 struct bfs_inode *di;
 381                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 382                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 383                 unsigned long sblock, eblock;
 384
 385                 if (!off) {
 386                         brelse(bh);
 387                         bh = sb_bread(s, block);
 388                 }
 389
 390                 if (!bh)
 391                         continue;
 392
 393                 di = (struct bfs_inode *)bh->b_data + off;
 394
 395                 if (!di->i_ino) {
 396                         info->si_freei++;
 397                         continue;
 398                 }
 399                 set_bit(i, info->si_imap);
 400                 info->si_freeb -= BFS_FILEBLOCKS(di);
 401
 402                 sblock =  le32_to_cpu(di->i_sblock);
 403                 eblock =  le32_to_cpu(di->i_eblock);
 404                 if (eblock > info->si_lf_eblk)
 405                         info->si_lf_eblk = eblock;
 406         }
 407         brelse(bh);
 408         if (!(s->s_flags & MS_RDONLY)) {
 409                 mark_buffer_dirty(info->si_sbh);
 410                 s->s_dirt = 1;
 411         }
 412         dump_imap("read_super", s);
 413         return 0;
 414
 415 out:
 416         brelse(bh);
 417         kfree(info);
 418         s->s_fs_info = NULL;
 419         return ret;
 420 }
 421
 422 static int bfs_get_sb(struct file_system_type *fs_type,
 423         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 424 {
 425         return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
 426 }
 427
 428 static struct file_system_type bfs_fs_type = {
 429         .owner          = THIS_MODULE,
 430         .name           = "bfs",
 431         .get_sb         = bfs_get_sb,
 432         .kill_sb        = kill_block_super,
 433         .fs_flags       = FS_REQUIRES_DEV,
 434 };
 435
 436 static int __init init_bfs_fs(void)
 437 {
 438         int err = init_inodecache();
 439         if (err)
 440                 goto out1;
 441         err = register_filesystem(&bfs_fs_type);
 442         if (err)
 443                 goto out;
 444         return 0;
 445 out:
 446         destroy_inodecache();
 447 out1:
 448         return err;
 449 }
 450
 451 static void __exit exit_bfs_fs(void)
 452 {
 453         unregister_filesystem(&bfs_fs_type);
 454         destroy_inodecache();
 455 }
 456
 457 module_init(init_bfs_fs)
 458 module_exit(exit_bfs_fs)