fs/minix/inode.c

/* */
This source file includes following definitions.
minix_put_inode
minix_put_super
minix_read_super
minix_statfs
block_bmap
minix_bmap
inode_getblk
block_getblk
minix_getblk
minix_bread
minix_read_inode
minix_write_inode
   1 /*
   2  *  linux/fs/minix/inode.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6 
   7 #include <linux/sched.h>
   8 #include <linux/minix_fs.h>
   9 #include <linux/kernel.h>
  10 #include <linux/mm.h>
  11 #include <linux/string.h>
  12 #include <linux/stat.h>
  13 #include <linux/locks.h>
  14 
  15 #include <asm/system.h>
  16 #include <asm/segment.h>
  17 
  18 void minix_put_inode(struct inode *inode)
     /*  */
  19 {
  20         if (inode->i_nlink)
  21                 return;
  22         inode->i_size = 0;
  23         minix_truncate(inode);
  24         minix_free_inode(inode);
  25 }
  26 
  27 void minix_put_super(struct super_block *sb)
     /*  */
  28 {
  29         int i;
  30 
  31         lock_super(sb);
  32         sb->s_dev = 0;
  33         for(i = 0 ; i < MINIX_I_MAP_SLOTS ; i++)
  34                 brelse(sb->u.minix_sb.s_imap[i]);
  35         for(i = 0 ; i < MINIX_Z_MAP_SLOTS ; i++)
  36                 brelse(sb->u.minix_sb.s_zmap[i]);
  37         unlock_super(sb);
  38         return;
  39 }
  40 
  41 static struct super_operations minix_sops = { 
  42         minix_read_inode,
  43         NULL,
  44         minix_write_inode,
  45         minix_put_inode,
  46         minix_put_super,
  47         NULL,
  48         minix_statfs
  49 };
  50 
  51 struct super_block *minix_read_super(struct super_block *s,void *data)
     /*  */
  52 {
  53         struct buffer_head *bh;
  54         struct minix_super_block *ms;
  55         int i,dev=s->s_dev,block;
  56 
  57         if (32 != sizeof (struct minix_inode))
  58                 panic("bad i-node size");
  59         lock_super(s);
  60         if (!(bh = bread(dev,1,BLOCK_SIZE))) {
  61                 s->s_dev=0;
  62                 unlock_super(s);
  63                 printk("MINIX-fs: unable to read superblock\n");
  64                 return NULL;
  65         }
  66         ms = (struct minix_super_block *) bh->b_data;
  67         s->s_blocksize = 1024;
  68         s->u.minix_sb.s_ninodes = ms->s_ninodes;
  69         s->u.minix_sb.s_nzones = ms->s_nzones;
  70         s->u.minix_sb.s_imap_blocks = ms->s_imap_blocks;
  71         s->u.minix_sb.s_zmap_blocks = ms->s_zmap_blocks;
  72         s->u.minix_sb.s_firstdatazone = ms->s_firstdatazone;
  73         s->u.minix_sb.s_log_zone_size = ms->s_log_zone_size;
  74         s->u.minix_sb.s_max_size = ms->s_max_size;
  75         s->s_magic = ms->s_magic;
  76         brelse(bh);
  77         if (s->s_magic == MINIX_SUPER_MAGIC) {
  78                 s->u.minix_sb.s_dirsize = 16;
  79                 s->u.minix_sb.s_namelen = 14;
  80         } else if (s->s_magic == MINIX_SUPER_MAGIC2) {
  81                 s->u.minix_sb.s_dirsize = 32;
  82                 s->u.minix_sb.s_namelen = 30;
  83         } else {
  84                 s->s_dev = 0;
  85                 unlock_super(s);
  86                 printk("MINIX-fs magic match failed\n");
  87                 return NULL;
  88         }
  89         for (i=0;i < MINIX_I_MAP_SLOTS;i++)
  90                 s->u.minix_sb.s_imap[i] = NULL;
  91         for (i=0;i < MINIX_Z_MAP_SLOTS;i++)
  92                 s->u.minix_sb.s_zmap[i] = NULL;
  93         block=2;
  94         for (i=0 ; i < s->u.minix_sb.s_imap_blocks ; i++)
  95                 if ((s->u.minix_sb.s_imap[i]=bread(dev,block,BLOCK_SIZE)) != NULL)
  96                         block++;
  97                 else
  98                         break;
  99         for (i=0 ; i < s->u.minix_sb.s_zmap_blocks ; i++)
 100                 if ((s->u.minix_sb.s_zmap[i]=bread(dev,block,BLOCK_SIZE)) != NULL)
 101                         block++;
 102                 else
 103                         break;
 104         if (block != 2+s->u.minix_sb.s_imap_blocks+s->u.minix_sb.s_zmap_blocks) {
 105                 for(i=0;i<MINIX_I_MAP_SLOTS;i++)
 106                         brelse(s->u.minix_sb.s_imap[i]);
 107                 for(i=0;i<MINIX_Z_MAP_SLOTS;i++)
 108                         brelse(s->u.minix_sb.s_zmap[i]);
 109                 s->s_dev=0;
 110                 unlock_super(s);
 111                 printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
 112                 return NULL;
 113         }
 114         s->u.minix_sb.s_imap[0]->b_data[0] |= 1;
 115         s->u.minix_sb.s_zmap[0]->b_data[0] |= 1;
 116         /* set up enough so that it can read an inode */
 117         s->s_dev = dev;
 118         s->s_op = &minix_sops;
 119         s->s_mounted = iget(s,MINIX_ROOT_INO);
 120         unlock_super(s);
 121         if (!s->s_mounted) {
 122                 s->s_dev = 0;
 123                 printk("MINIX-fs: get root inode failed\n");
 124                 return NULL;
 125         }
 126         return s;
 127 }
 128 
 129 void minix_statfs(struct super_block *sb, struct statfs *buf)
     /*  */
 130 {
 131         long tmp;
 132 
 133         put_fs_long(MINIX_SUPER_MAGIC, &buf->f_type);
 134         put_fs_long(1024, &buf->f_bsize);
 135         put_fs_long(sb->u.minix_sb.s_nzones << sb->u.minix_sb.s_log_zone_size, &buf->f_blocks);
 136         tmp = minix_count_free_blocks(sb);
 137         put_fs_long(tmp, &buf->f_bfree);
 138         put_fs_long(tmp, &buf->f_bavail);
 139         put_fs_long(sb->u.minix_sb.s_ninodes, &buf->f_files);
 140         put_fs_long(minix_count_free_inodes(sb), &buf->f_ffree);
 141         /* Don't know what value to put in buf->f_fsid */
 142 }
 143 
 144 #define inode_bmap(inode,nr) ((inode)->u.minix_i.i_data[(nr)])
 145 
 146 static int block_bmap(struct buffer_head * bh, int nr)
     /*  */
 147 {
 148         int tmp;
 149 
 150         if (!bh)
 151                 return 0;
 152         tmp = ((unsigned short *) bh->b_data)[nr];
 153         brelse(bh);
 154         return tmp;
 155 }
 156 
 157 int minix_bmap(struct inode * inode,int block)
     /*  */
 158 {
 159         int i;
 160 
 161         if (block<0) {
 162                 printk("minix_bmap: block<0");
 163                 return 0;
 164         }
 165         if (block >= 7+512+512*512) {
 166                 printk("minix_bmap: block>big");
 167                 return 0;
 168         }
 169         if (block < 7)
 170                 return inode_bmap(inode,block);
 171         block -= 7;
 172         if (block < 512) {
 173                 i = inode_bmap(inode,7);
 174                 if (!i)
 175                         return 0;
 176                 return block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block);
 177         }
 178         block -= 512;
 179         i = inode_bmap(inode,8);
 180         if (!i)
 181                 return 0;
 182         i = block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block>>9);
 183         if (!i)
 184                 return 0;
 185         return block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block & 511);
 186 }
 187 
 188 static struct buffer_head * inode_getblk(struct inode * inode, int nr, int create)
     /*  */
 189 {
 190         int tmp;
 191         unsigned short *p;
 192         struct buffer_head * result;
 193 
 194         p = inode->u.minix_i.i_data + nr;
 195 repeat:
 196         tmp = *p;
 197         if (tmp) {
 198                 result = getblk(inode->i_dev, tmp, BLOCK_SIZE);
 199                 if (tmp == *p)
 200                         return result;
 201                 brelse(result);
 202                 goto repeat;
 203         }
 204         if (!create)
 205                 return NULL;
 206         tmp = minix_new_block(inode->i_sb);
 207         if (!tmp)
 208                 return NULL;
 209         result = getblk(inode->i_dev, tmp, BLOCK_SIZE);
 210         if (*p) {
 211                 minix_free_block(inode->i_sb,tmp);
 212                 brelse(result);
 213                 goto repeat;
 214         }
 215         *p = tmp;
 216         inode->i_ctime = CURRENT_TIME;
 217         inode->i_dirt = 1;
 218         return result;
 219 }
 220 
 221 static struct buffer_head * block_getblk(struct inode * inode, 
     /*  */
 222         struct buffer_head * bh, int nr, int create)
 223 {
 224         int tmp;
 225         unsigned short *p;
 226         struct buffer_head * result;
 227 
 228         if (!bh)
 229                 return NULL;
 230         if (!bh->b_uptodate) {
 231                 ll_rw_block(READ, 1, &bh);
 232                 wait_on_buffer(bh);
 233                 if (!bh->b_uptodate) {
 234                         brelse(bh);
 235                         return NULL;
 236                 }
 237         }
 238         p = nr + (unsigned short *) bh->b_data;
 239 repeat:
 240         tmp = *p;
 241         if (tmp) {
 242                 result = getblk(bh->b_dev, tmp, BLOCK_SIZE);
 243                 if (tmp == *p) {
 244                         brelse(bh);
 245                         return result;
 246                 }
 247                 brelse(result);
 248                 goto repeat;
 249         }
 250         if (!create) {
 251                 brelse(bh);
 252                 return NULL;
 253         }
 254         tmp = minix_new_block(inode->i_sb);
 255         if (!tmp) {
 256                 brelse(bh);
 257                 return NULL;
 258         }
 259         result = getblk(bh->b_dev, tmp, BLOCK_SIZE);
 260         if (*p) {
 261                 minix_free_block(inode->i_sb,tmp);
 262                 brelse(result);
 263                 goto repeat;
 264         }
 265         *p = tmp;
 266         bh->b_dirt = 1;
 267         brelse(bh);
 268         return result;
 269 }
 270 
 271 struct buffer_head * minix_getblk(struct inode * inode, int block, int create)
     /*  */
 272 {
 273         struct buffer_head * bh;
 274 
 275         if (block<0) {
 276                 printk("minix_getblk: block<0");
 277                 return NULL;
 278         }
 279         if (block >= 7+512+512*512) {
 280                 printk("minix_getblk: block>big");
 281                 return NULL;
 282         }
 283         if (block < 7)
 284                 return inode_getblk(inode,block,create);
 285         block -= 7;
 286         if (block < 512) {
 287                 bh = inode_getblk(inode,7,create);
 288                 return block_getblk(inode, bh, block, create);
 289         }
 290         block -= 512;
 291         bh = inode_getblk(inode,8,create);
 292         bh = block_getblk(inode, bh, block>>9, create);
 293         return block_getblk(inode, bh, block & 511, create);
 294 }
 295 
 296 struct buffer_head * minix_bread(struct inode * inode, int block, int create)
     /*  */
 297 {
 298         struct buffer_head * bh;
 299 
 300         bh = minix_getblk(inode,block,create);
 301         if (!bh || bh->b_uptodate)
 302                 return bh;
 303         ll_rw_block(READ, 1, &bh);
 304         wait_on_buffer(bh);
 305         if (bh->b_uptodate)
 306                 return bh;
 307         brelse(bh);
 308         return NULL;
 309 }
 310 
 311 void minix_read_inode(struct inode * inode)
     /*  */
 312 {
 313         struct buffer_head * bh;
 314         struct minix_inode * raw_inode;
 315         int block, ino;
 316 
 317         ino = inode->i_ino;
 318         inode->i_op = NULL;
 319         inode->i_mode = 0;
 320         if (!ino || ino >= inode->i_sb->u.minix_sb.s_ninodes) {
 321                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 322                         inode->i_dev, ino);
 323                 return;
 324         }
 325         block = 2 + inode->i_sb->u.minix_sb.s_imap_blocks +
 326                     inode->i_sb->u.minix_sb.s_zmap_blocks +
 327                     (ino-1)/MINIX_INODES_PER_BLOCK;
 328         if (!(bh=bread(inode->i_dev,block, BLOCK_SIZE))) {
 329                 printk("Major problem: unable to read inode from dev 0x%04x\n",
 330                         inode->i_dev);
 331                 return;
 332         }
 333         raw_inode = ((struct minix_inode *) bh->b_data) +
 334                     (ino-1)%MINIX_INODES_PER_BLOCK;
 335         inode->i_mode = raw_inode->i_mode;
 336         inode->i_uid = raw_inode->i_uid;
 337         inode->i_gid = raw_inode->i_gid;
 338         inode->i_nlink = raw_inode->i_nlinks;
 339         inode->i_size = raw_inode->i_size;
 340         inode->i_mtime = inode->i_atime = inode->i_ctime = raw_inode->i_time;
 341         inode->i_blocks = inode->i_blksize = 0;
 342         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 343                 inode->i_rdev = raw_inode->i_zone[0];
 344         else for (block = 0; block < 9; block++)
 345                 inode->u.minix_i.i_data[block] = raw_inode->i_zone[block];
 346         brelse(bh);
 347         if (S_ISREG(inode->i_mode))
 348                 inode->i_op = &minix_file_inode_operations;
 349         else if (S_ISDIR(inode->i_mode))
 350                 inode->i_op = &minix_dir_inode_operations;
 351         else if (S_ISLNK(inode->i_mode))
 352                 inode->i_op = &minix_symlink_inode_operations;
 353         else if (S_ISCHR(inode->i_mode))
 354                 inode->i_op = &chrdev_inode_operations;
 355         else if (S_ISBLK(inode->i_mode))
 356                 inode->i_op = &blkdev_inode_operations;
 357         else if (S_ISFIFO(inode->i_mode)) {
 358                 inode->i_op = &fifo_inode_operations;
 359                 inode->i_pipe = 1;
 360                 PIPE_BASE(*inode) = NULL;
 361                 PIPE_HEAD(*inode) = PIPE_TAIL(*inode) = 0;
 362                 PIPE_READ_WAIT(*inode) = PIPE_WRITE_WAIT(*inode) = NULL;
 363                 PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 0;
 364         }
 365 }
 366 
 367 void minix_write_inode(struct inode * inode)
     /*  */
 368 {
 369         struct buffer_head * bh;
 370         struct minix_inode * raw_inode;
 371         int ino, block;
 372 
 373         ino = inode->i_ino;
 374         if (!ino || ino >= inode->i_sb->u.minix_sb.s_ninodes) {
 375                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 376                         inode->i_dev, ino);
 377                 inode->i_dirt = 0;
 378                 return;
 379         }
 380         block = 2 + inode->i_sb->u.minix_sb.s_imap_blocks + inode->i_sb->u.minix_sb.s_zmap_blocks +
 381                 (ino-1)/MINIX_INODES_PER_BLOCK;
 382         if (!(bh=bread(inode->i_dev, block, BLOCK_SIZE))) {
 383                 printk("unable to read i-node block\n");
 384                 inode->i_dirt = 0;
 385                 return;
 386         }
 387         raw_inode = ((struct minix_inode *)bh->b_data) +
 388                 (ino-1)%MINIX_INODES_PER_BLOCK;
 389         raw_inode->i_mode = inode->i_mode;
 390         raw_inode->i_uid = inode->i_uid;
 391         raw_inode->i_gid = inode->i_gid;
 392         raw_inode->i_nlinks = inode->i_nlink;
 393         raw_inode->i_size = inode->i_size;
 394         raw_inode->i_time = inode->i_mtime;
 395         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 396                 raw_inode->i_zone[0] = inode->i_rdev;
 397         else for (block = 0; block < 9; block++)
 398                 raw_inode->i_zone[block] = inode->u.minix_i.i_data[block];
 399         inode->i_dirt=0;
 400         bh->b_dirt=1;
 401         brelse(bh);
 402 }
/* */
root/fs/minix/inode.c

DEFINITIONS
