fs/bfs/inode.c

   1 /*
   2  *      fs/bfs/inode.c
   3  *      BFS superblock and inode operations.
   4  *      Copyright (C) 1999 Tigran Aivazian <tigran@ocston.org>
   5  *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/mm.h>
  10 #include <linux/slab.h>
  11 #include <linux/init.h>
  12 #include <linux/locks.h>
  13 #include <linux/bfs_fs.h>
  14
  15 #include <asm/uaccess.h>
  16
  17 #include "bfs_defs.h"
  18
  19 MODULE_AUTHOR("Tigran A. Aivazian");
  20 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
  21 EXPORT_NO_SYMBOLS;
  22
  23 #undef DEBUG
  24
  25 #ifdef DEBUG
  26 #define dprintf(x...)   printf(x)
  27 #else
  28 #define dprintf(x...)
  29 #endif
  30
  31 void dump_imap(const char *prefix, struct super_block * s);
  32
  33 static void bfs_read_inode(struct inode * inode)
  34 {
  35         unsigned long ino = inode->i_ino;
  36         kdev_t dev = inode->i_dev;
  37         struct bfs_inode * di;
  38         struct buffer_head * bh;
  39         int block, off;
  40
  41         if (ino < BFS_ROOT_INO || ino > inode->i_sb->su_lasti) {
  42                 printf("Bad inode number %s:%08lx\n", bdevname(dev), ino);
  43                 make_bad_inode(inode);
  44                 return;
  45         }
  46
  47         block = (ino - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;
  48         bh = bread(dev, block, BFS_BSIZE);
  49         if (!bh) {
  50                 printf("Unable to read inode %s:%08lx\n", bdevname(dev), ino);
  51                 make_bad_inode(inode);
  52                 return;
  53         }
  54
  55         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
  56         di = (struct bfs_inode *)bh->b_data + off;
  57
  58         inode->i_mode = 0x0000FFFF & di->i_mode;
  59         if (di->i_vtype == BFS_VDIR) {
  60                 inode->i_mode |= S_IFDIR;
  61                 inode->i_op = &bfs_dir_inops;
  62                 inode->i_fop = &bfs_dir_operations;
  63         } else if (di->i_vtype == BFS_VREG) {
  64                 inode->i_mode |= S_IFREG;
  65                 inode->i_op = &bfs_file_inops;
  66                 inode->i_fop = &bfs_file_operations;
  67                 inode->i_mapping->a_ops = &bfs_aops;
  68         }
  69
  70         inode->i_uid = di->i_uid;
  71         inode->i_gid = di->i_gid;
  72         inode->i_nlink = di->i_nlink;
  73         inode->i_size = BFS_FILESIZE(di);
  74         inode->i_blocks = BFS_FILEBLOCKS(di);
  75         inode->i_blksize = PAGE_SIZE;
  76         inode->i_atime = di->i_atime;
  77         inode->i_mtime = di->i_mtime;
  78         inode->i_ctime = di->i_ctime;
  79         inode->i_rdev = 0; /* BFS doesn't have special nodes */
  80         inode->iu_dsk_ino = di->i_ino; /* can be 0 so we store a copy */
  81         inode->iu_sblock = di->i_sblock;
  82         inode->iu_eblock = di->i_eblock;
  83
  84         brelse(bh);
  85 }
  86
  87 static void bfs_write_inode(struct inode * inode)
  88 {
  89         unsigned long ino = inode->i_ino;
  90         kdev_t dev = inode->i_dev;
  91         struct bfs_inode * di;
  92         struct buffer_head * bh;
  93         int block, off;
  94
  95         if (ino < BFS_ROOT_INO || ino > inode->i_sb->su_lasti) {
  96                 printf("Bad inode number %s:%08lx\n", bdevname(dev), ino);
  97                 return;
  98         }
  99
 100         block = (ino - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;
 101         bh = bread(dev, block, BFS_BSIZE);
 102         if (!bh) {
 103                 printf("Unable to read inode %s:%08lx\n", bdevname(dev), ino);
 104                 return;
 105         }
 106
 107         off = (ino - BFS_ROOT_INO)%BFS_INODES_PER_BLOCK;
 108         di = (struct bfs_inode *)bh->b_data + off;
 109
 110         if (inode->i_ino == BFS_ROOT_INO)
 111                 di->i_vtype = BFS_VDIR;
 112         else
 113                 di->i_vtype = BFS_VREG;
 114
 115         di->i_ino = inode->i_ino;
 116         di->i_mode = inode->i_mode;
 117         di->i_uid = inode->i_uid;
 118         di->i_gid = inode->i_gid;
 119         di->i_nlink = inode->i_nlink;
 120         di->i_atime = inode->i_atime;
 121         di->i_mtime = inode->i_mtime;
 122         di->i_ctime = inode->i_ctime;
 123         di->i_sblock = inode->iu_sblock;
 124         di->i_eblock = inode->iu_eblock;
 125         di->i_eoffset = di->i_sblock * BFS_BSIZE + inode->i_size - 1;
 126
 127         mark_buffer_dirty(bh, 0);
 128         brelse(bh);
 129 }
 130
 131 static void bfs_delete_inode(struct inode * inode)
 132 {
 133         unsigned long ino = inode->i_ino;
 134         kdev_t dev = inode->i_dev;
 135         struct bfs_inode * di;
 136         struct buffer_head * bh;
 137         int block, off;
 138         struct super_block * s = inode->i_sb;
 139
 140         dprintf("ino=%08lx\n", inode->i_ino);
 141
 142         if (!inode || !inode->i_dev || inode->i_count > 1 || inode->i_nlink || !s)
 143                 return;
 144         if (inode->i_ino < BFS_ROOT_INO || inode->i_ino > inode->i_sb->su_lasti) {
 145                 printf("invalid ino=%08lx\n", inode->i_ino);
 146                 return;
 147         }
 148
 149         inode->i_size = 0;
 150         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 151         mark_inode_dirty(inode);
 152         block = (ino - BFS_ROOT_INO)/BFS_INODES_PER_BLOCK + 1;
 153         bh = bread(dev, block, BFS_BSIZE);
 154         if (!bh) {
 155                 printf("Unable to read inode %s:%08lx\n", bdevname(dev), ino);
 156                 return;
 157         }
 158         off = (ino - BFS_ROOT_INO)%BFS_INODES_PER_BLOCK;
 159         di = (struct bfs_inode *)bh->b_data + off;
 160         if (di->i_ino) {
 161                 s->su_freeb += BFS_FILEBLOCKS(di);
 162                 s->su_freei++;
 163                 clear_bit(di->i_ino, s->su_imap);
 164                 dump_imap("delete_inode", s);
 165         }
 166         di->i_ino = 0;
 167         di->i_sblock = 0;
 168         mark_buffer_dirty(bh, 0);
 169         brelse(bh);
 170
 171         /* if this was the last file, make the previous
 172            block "last files last block" even if there is no real file there,
 173            saves us 1 gap */
 174         if (s->su_lf_eblk == inode->iu_eblock) {
 175                 s->su_lf_eblk = inode->iu_sblock - 1;
 176                 mark_buffer_dirty(s->su_sbh, 1);
 177         }
 178         clear_inode(inode);
 179 }
 180
 181 static void bfs_put_super(struct super_block *s)
 182 {
 183         brelse(s->su_sbh);
 184         kfree(s->su_imap);
 185 }
 186
 187 static int bfs_statfs(struct super_block *s, struct statfs *buf)
 188 {
 189         buf->f_type = BFS_MAGIC;
 190         buf->f_bsize = s->s_blocksize;
 191         buf->f_blocks = s->su_blocks;
 192         buf->f_bfree = buf->f_bavail = s->su_freeb;
 193         buf->f_files = s->su_lasti + 1 - BFS_ROOT_INO;
 194         buf->f_ffree = s->su_freei;
 195         buf->f_fsid.val[0] = s->s_dev;
 196         buf->f_namelen = BFS_NAMELEN;
 197         return 0;
 198 }
 199
 200 static void bfs_write_super(struct super_block *s)
 201 {
 202         if (!(s->s_flags & MS_RDONLY))
 203                 mark_buffer_dirty(s->su_sbh, 1);
 204         s->s_dirt = 0;
 205 }
 206
 207 static struct super_operations bfs_sops = {
 208         read_inode:     bfs_read_inode,
 209         write_inode:    bfs_write_inode,
 210         delete_inode:   bfs_delete_inode,
 211         put_super:      bfs_put_super,
 212         write_super:    bfs_write_super,
 213         statfs:         bfs_statfs,
 214 };
 215
 216 void dump_imap(const char *prefix, struct super_block * s)
 217 {
 218 #if 0
 219         int i;
 220         char *tmpbuf = (char *)get_free_page(GFP_KERNEL);
 221
 222         if (!tmpbuf)
 223                 return;
 224         for (i=s->su_lasti; i>=0; i--) {
 225                 if (i>PAGE_SIZE-100) break;
 226                 if (test_bit(i, s->su_imap))
 227                         strcat(tmpbuf, "1");
 228                 else
 229                         strcat(tmpbuf, "0");
 230         }
 231         printk(KERN_ERR "BFS-fs: %s: lasti=%08lx <%s>\n", prefix, s->su_lasti, tmpbuf);
 232         free_page((unsigned long)tmpbuf);
 233 #endif
 234 }
 235
 236 static struct super_block * bfs_read_super(struct super_block * s,
 237         void * data, int silent)
 238 {
 239         kdev_t dev;
 240         struct buffer_head * bh;
 241         struct bfs_super_block * bfs_sb;
 242         struct inode * inode;
 243         int i, imap_len;
 244
 245         dev = s->s_dev;
 246         set_blocksize(dev, BFS_BSIZE);
 247         s->s_blocksize = BFS_BSIZE;
 248         s->s_blocksize_bits = BFS_BSIZE_BITS;
 249
 250         bh = bread(dev, 0, BFS_BSIZE);
 251         if(!bh)
 252                 goto out;
 253         bfs_sb = (struct bfs_super_block *)bh->b_data;
 254         if (bfs_sb->s_magic != BFS_MAGIC) {
 255                 if (!silent)
 256                         printf("No BFS filesystem on %s (magic=%08x)\n",
 257                                 bdevname(dev), bfs_sb->s_magic);
 258                 goto out;
 259         }
 260         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 261                 printf("%s is unclean, continuing\n", bdevname(dev));
 262
 263         s->s_magic = BFS_MAGIC;
 264         s->su_bfs_sb = bfs_sb;
 265         s->su_sbh = bh;
 266         s->su_lasti = (bfs_sb->s_start - BFS_BSIZE)/sizeof(struct bfs_inode)
 267                         + BFS_ROOT_INO - 1;
 268
 269         imap_len = s->su_lasti/8 + 1;
 270         s->su_imap = kmalloc(imap_len, GFP_KERNEL);
 271         if (!s->su_imap)
 272                 goto out;
 273         memset(s->su_imap, 0, imap_len);
 274         for (i=0; i<BFS_ROOT_INO; i++)
 275                 set_bit(i, s->su_imap);
 276
 277         s->s_op = &bfs_sops;
 278         inode = iget(s, BFS_ROOT_INO);
 279         if (!inode) {
 280                 kfree(s->su_imap);
 281                 goto out;
 282         }
 283         s->s_root = d_alloc_root(inode);
 284         if (!s->s_root) {
 285                 iput(inode);
 286                 kfree(s->su_imap);
 287                 goto out;
 288         }
 289
 290         s->su_blocks = (bfs_sb->s_end + 1)>>BFS_BSIZE_BITS; /* for statfs(2) */
 291         s->su_freeb = (bfs_sb->s_end + 1 - bfs_sb->s_start)>>BFS_BSIZE_BITS;
 292         s->su_freei = 0;
 293         s->su_lf_eblk = 0;
 294         s->su_lf_sblk = 0;
 295         s->su_lf_ioff = 0;
 296         for (i=BFS_ROOT_INO; i<=s->su_lasti; i++) {
 297                 inode = iget(s,i);
 298                 if (inode->iu_dsk_ino == 0)
 299                         s->su_freei++;
 300                 else {
 301                         set_bit(i, s->su_imap);
 302                         s->su_freeb -= inode->i_blocks;
 303                         if (inode->iu_eblock > s->su_lf_eblk) {
 304                                 s->su_lf_eblk = inode->iu_eblock;
 305                                 s->su_lf_sblk = inode->iu_sblock;
 306                                 s->su_lf_ioff = BFS_INO2OFF(i);
 307                         }
 308                 }
 309                 iput(inode);
 310         }
 311         if (!(s->s_flags & MS_RDONLY)) {
 312                 mark_buffer_dirty(bh, 1);
 313                 s->s_dirt = 1;
 314         }
 315         dump_imap("read_super", s);
 316         return s;
 317
 318 out:
 319         brelse(bh);
 320         return NULL;
 321 }
 322
 323 static DECLARE_FSTYPE_DEV( bfs_fs_type, "bfs", bfs_read_super);
 324
 325 static int __init init_bfs_fs(void)
 326 {
 327         return register_filesystem(&bfs_fs_type);
 328 }
 329
 330 static void __exit exit_bfs_fs(void)
 331 {
 332         unregister_filesystem(&bfs_fs_type);
 333 }
 334
 335 module_init(init_bfs_fs)
 336 module_exit(exit_bfs_fs)