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->s_dev = 0;
  79                 unlock_super(s);
  80                 printk("MINIX-fs magic match failed\n");
  81                 return NULL;
  82         }
  83         for (i=0;i < MINIX_I_MAP_SLOTS;i++)
  84                 s->u.minix_sb.s_imap[i] = NULL;
  85         for (i=0;i < MINIX_Z_MAP_SLOTS;i++)
  86                 s->u.minix_sb.s_zmap[i] = NULL;
  87         block=2;
  88         for (i=0 ; i < s->u.minix_sb.s_imap_blocks ; i++)
  89                 if ((s->u.minix_sb.s_imap[i]=bread(dev,block,BLOCK_SIZE)) != NULL)
  90                         block++;
  91                 else
  92                         break;
  93         for (i=0 ; i < s->u.minix_sb.s_zmap_blocks ; i++)
  94                 if ((s->u.minix_sb.s_zmap[i]=bread(dev,block,BLOCK_SIZE)) != NULL)
  95                         block++;
  96                 else
  97                         break;
  98         if (block != 2+s->u.minix_sb.s_imap_blocks+s->u.minix_sb.s_zmap_blocks) {
  99                 for(i=0;i<MINIX_I_MAP_SLOTS;i++)
 100                         brelse(s->u.minix_sb.s_imap[i]);
 101                 for(i=0;i<MINIX_Z_MAP_SLOTS;i++)
 102                         brelse(s->u.minix_sb.s_zmap[i]);
 103                 s->s_dev=0;
 104                 unlock_super(s);
 105                 printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
 106                 return NULL;
 107         }
 108         s->u.minix_sb.s_imap[0]->b_data[0] |= 1;
 109         s->u.minix_sb.s_zmap[0]->b_data[0] |= 1;
 110         /* set up enough so that it can read an inode */
 111         s->s_dev = dev;
 112         s->s_op = &minix_sops;
 113         s->s_mounted = iget(s,MINIX_ROOT_INO);
 114         unlock_super(s);
 115         if (!s->s_mounted) {
 116                 s->s_dev = 0;
 117                 printk("MINIX-fs: get root inode failed\n");
 118                 return NULL;
 119         }
 120         return s;
 121 }
 122 
 123 void minix_statfs(struct super_block *sb, struct statfs *buf)
     /*  */
 124 {
 125         long tmp;
 126 
 127         put_fs_long(MINIX_SUPER_MAGIC, &buf->f_type);
 128         put_fs_long(1024, &buf->f_bsize);
 129         put_fs_long(sb->u.minix_sb.s_nzones << sb->u.minix_sb.s_log_zone_size, &buf->f_blocks);
 130         tmp = minix_count_free_blocks(sb);
 131         put_fs_long(tmp, &buf->f_bfree);
 132         put_fs_long(tmp, &buf->f_bavail);
 133         put_fs_long(sb->u.minix_sb.s_ninodes, &buf->f_files);
 134         put_fs_long(minix_count_free_inodes(sb), &buf->f_ffree);
 135         /* Don't know what value to put in buf->f_fsid */
 136 }
 137 
 138 #define inode_bmap(inode,nr) ((inode)->u.minix_i.i_data[(nr)])
 139 
 140 static int block_bmap(struct buffer_head * bh, int nr)
     /*  */
 141 {
 142         int tmp;
 143 
 144         if (!bh)
 145                 return 0;
 146         tmp = ((unsigned short *) bh->b_data)[nr];
 147         brelse(bh);
 148         return tmp;
 149 }
 150 
 151 int minix_bmap(struct inode * inode,int block)
     /*  */
 152 {
 153         int i;
 154 
 155         if (block<0) {
 156                 printk("minix_bmap: block<0");
 157                 return 0;
 158         }
 159         if (block >= 7+512+512*512) {
 160                 printk("minix_bmap: block>big");
 161                 return 0;
 162         }
 163         if (block < 7)
 164                 return inode_bmap(inode,block);
 165         block -= 7;
 166         if (block < 512) {
 167                 i = inode_bmap(inode,7);
 168                 if (!i)
 169                         return 0;
 170                 return block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block);
 171         }
 172         block -= 512;
 173         i = inode_bmap(inode,8);
 174         if (!i)
 175                 return 0;
 176         i = block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block>>9);
 177         if (!i)
 178                 return 0;
 179         return block_bmap(bread(inode->i_dev,i,BLOCK_SIZE),block & 511);
 180 }
 181 
 182 static struct buffer_head * inode_getblk(struct inode * inode, int nr, int create)
     /*  */
 183 {
 184         int tmp;
 185         unsigned short *p;
 186         struct buffer_head * result;
 187 
 188         p = inode->u.minix_i.i_data + nr;
 189 repeat:
 190         tmp = *p;
 191         if (tmp) {
 192                 result = getblk(inode->i_dev, tmp, BLOCK_SIZE);
 193                 if (tmp == *p)
 194                         return result;
 195                 brelse(result);
 196                 goto repeat;
 197         }
 198         if (!create)
 199                 return NULL;
 200         tmp = minix_new_block(inode->i_sb);
 201         if (!tmp)
 202                 return NULL;
 203         result = getblk(inode->i_dev, tmp, BLOCK_SIZE);
 204         if (*p) {
 205                 minix_free_block(inode->i_sb,tmp);
 206                 brelse(result);
 207                 goto repeat;
 208         }
 209         *p = tmp;
 210         inode->i_ctime = CURRENT_TIME;
 211         inode->i_dirt = 1;
 212         return result;
 213 }
 214 
 215 static struct buffer_head * block_getblk(struct inode * inode, 
     /*  */
 216         struct buffer_head * bh, int nr, int create)
 217 {
 218         int tmp;
 219         unsigned short *p;
 220         struct buffer_head * result;
 221 
 222         if (!bh)
 223                 return NULL;
 224         if (!bh->b_uptodate) {
 225                 ll_rw_block(READ, 1, &bh);
 226                 wait_on_buffer(bh);
 227                 if (!bh->b_uptodate) {
 228                         brelse(bh);
 229                         return NULL;
 230                 }
 231         }
 232         p = nr + (unsigned short *) bh->b_data;
 233 repeat:
 234         tmp = *p;
 235         if (tmp) {
 236                 result = getblk(bh->b_dev, tmp, BLOCK_SIZE);
 237                 if (tmp == *p) {
 238                         brelse(bh);
 239                         return result;
 240                 }
 241                 brelse(result);
 242                 goto repeat;
 243         }
 244         if (!create) {
 245                 brelse(bh);
 246                 return NULL;
 247         }
 248         tmp = minix_new_block(inode->i_sb);
 249         if (!tmp) {
 250                 brelse(bh);
 251                 return NULL;
 252         }
 253         result = getblk(bh->b_dev, tmp, BLOCK_SIZE);
 254         if (*p) {
 255                 minix_free_block(inode->i_sb,tmp);
 256                 brelse(result);
 257                 goto repeat;
 258         }
 259         *p = tmp;
 260         bh->b_dirt = 1;
 261         brelse(bh);
 262         return result;
 263 }
 264 
 265 struct buffer_head * minix_getblk(struct inode * inode, int block, int create)
     /*  */
 266 {
 267         struct buffer_head * bh;
 268 
 269         if (block<0) {
 270                 printk("minix_getblk: block<0");
 271                 return NULL;
 272         }
 273         if (block >= 7+512+512*512) {
 274                 printk("minix_getblk: block>big");
 275                 return NULL;
 276         }
 277         if (block < 7)
 278                 return inode_getblk(inode,block,create);
 279         block -= 7;
 280         if (block < 512) {
 281                 bh = inode_getblk(inode,7,create);
 282                 return block_getblk(inode, bh, block, create);
 283         }
 284         block -= 512;
 285         bh = inode_getblk(inode,8,create);
 286         bh = block_getblk(inode, bh, block>>9, create);
 287         return block_getblk(inode, bh, block & 511, create);
 288 }
 289 
 290 struct buffer_head * minix_bread(struct inode * inode, int block, int create)
     /*  */
 291 {
 292         struct buffer_head * bh;
 293 
 294         bh = minix_getblk(inode,block,create);
 295         if (!bh || bh->b_uptodate)
 296                 return bh;
 297         ll_rw_block(READ, 1, &bh);
 298         wait_on_buffer(bh);
 299         if (bh->b_uptodate)
 300                 return bh;
 301         brelse(bh);
 302         return NULL;
 303 }
 304 
 305 void minix_read_inode(struct inode * inode)
     /*  */
 306 {
 307         struct buffer_head * bh;
 308         struct minix_inode * raw_inode;
 309         int block, ino;
 310 
 311         ino = inode->i_ino;
 312         inode->i_op = NULL;
 313         inode->i_mode = 0;
 314         if (!ino || ino >= inode->i_sb->u.minix_sb.s_ninodes) {
 315                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 316                         inode->i_dev, ino);
 317                 return;
 318         }
 319         block = 2 + inode->i_sb->u.minix_sb.s_imap_blocks +
 320                     inode->i_sb->u.minix_sb.s_zmap_blocks +
 321                     (ino-1)/MINIX_INODES_PER_BLOCK;
 322         if (!(bh=bread(inode->i_dev,block, BLOCK_SIZE))) {
 323                 printk("Major problem: unable to read inode from dev 0x%04x\n",
 324                         inode->i_dev);
 325                 return;
 326         }
 327         raw_inode = ((struct minix_inode *) bh->b_data) +
 328                     (ino-1)%MINIX_INODES_PER_BLOCK;
 329         inode->i_mode = raw_inode->i_mode;
 330         inode->i_uid = raw_inode->i_uid;
 331         inode->i_gid = raw_inode->i_gid;
 332         inode->i_nlink = raw_inode->i_nlinks;
 333         inode->i_size = raw_inode->i_size;
 334         inode->i_mtime = inode->i_atime = inode->i_ctime = raw_inode->i_time;
 335         inode->i_blocks = inode->i_blksize = 0;
 336         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 337                 inode->i_rdev = raw_inode->i_zone[0];
 338         else for (block = 0; block < 9; block++)
 339                 inode->u.minix_i.i_data[block] = raw_inode->i_zone[block];
 340         brelse(bh);
 341         if (S_ISREG(inode->i_mode))
 342                 inode->i_op = &minix_file_inode_operations;
 343         else if (S_ISDIR(inode->i_mode))
 344                 inode->i_op = &minix_dir_inode_operations;
 345         else if (S_ISLNK(inode->i_mode))
 346                 inode->i_op = &minix_symlink_inode_operations;
 347         else if (S_ISCHR(inode->i_mode))
 348                 inode->i_op = &minix_chrdev_inode_operations;
 349         else if (S_ISBLK(inode->i_mode))
 350                 inode->i_op = &minix_blkdev_inode_operations;
 351         else if (S_ISFIFO(inode->i_mode)) {
 352                 inode->i_op = &minix_fifo_inode_operations;
 353                 inode->i_pipe = 1;
 354                 PIPE_BASE(*inode) = NULL;
 355                 PIPE_HEAD(*inode) = PIPE_TAIL(*inode) = 0;
 356                 PIPE_READ_WAIT(*inode) = PIPE_WRITE_WAIT(*inode) = NULL;
 357                 PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 0;
 358         }
 359 }
 360 
 361 void minix_write_inode(struct inode * inode)
     /*  */
 362 {
 363         struct buffer_head * bh;
 364         struct minix_inode * raw_inode;
 365         int ino, block;
 366 
 367         ino = inode->i_ino;
 368         if (!ino || ino >= inode->i_sb->u.minix_sb.s_ninodes) {
 369                 printk("Bad inode number on dev 0x%04x: %d is out of range\n",
 370                         inode->i_dev, ino);
 371                 inode->i_dirt = 0;
 372                 return;
 373         }
 374         block = 2 + inode->i_sb->u.minix_sb.s_imap_blocks + inode->i_sb->u.minix_sb.s_zmap_blocks +
 375                 (ino-1)/MINIX_INODES_PER_BLOCK;
 376         if (!(bh=bread(inode->i_dev, block, BLOCK_SIZE)))
 377                 panic("unable to read i-node block");
 378         raw_inode = ((struct minix_inode *)bh->b_data) +
 379                 (ino-1)%MINIX_INODES_PER_BLOCK;
 380         raw_inode->i_mode = inode->i_mode;
 381         raw_inode->i_uid = inode->i_uid;
 382         raw_inode->i_gid = inode->i_gid;
 383         raw_inode->i_nlinks = inode->i_nlink;
 384         raw_inode->i_size = inode->i_size;
 385         raw_inode->i_time = inode->i_mtime;
 386         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 387                 raw_inode->i_zone[0] = inode->i_rdev;
 388         else for (block = 0; block < 9; block++)
 389                 raw_inode->i_zone[block] = inode->u.minix_i.i_data[block];
 390         inode->i_dirt=0;
 391         bh->b_dirt=1;
 392         brelse(bh);
 393 }
/* */
root/fs/minix/inode.c

DEFINITIONS
