191 lines
7 KiB
C
191 lines
7 KiB
C
/* fslib.c - routines needed by fs and fs utilities */
|
|
|
|
#include <minix/config.h> /* for unused stuff in <minix/type.h> :-( */
|
|
#include <ansi.h>
|
|
#include <limits.h>
|
|
#include <dirent.h>
|
|
#include <sys/types.h>
|
|
#include <minix/const.h>
|
|
#include <minix/type.h> /* for unshort :-( */
|
|
#include "mfs/const.h" /* depends of -I flag in Makefile */
|
|
#include "mfs/type.h" /* ditto */
|
|
#include "mfs/inode.h" /* ditto */
|
|
#include "mfs/super.h"
|
|
#include <minix/fslib.h>
|
|
|
|
/* The next routine is copied from fsck.c and mkfs.c... (Re)define some
|
|
* things for consistency. Some things should be done better.
|
|
*/
|
|
|
|
/* Convert from bit count to a block count. The usual expression
|
|
*
|
|
* (nr_bits + (1 << BITMAPSHIFT) - 1) >> BITMAPSHIFT
|
|
*
|
|
* doesn't work because of overflow.
|
|
*
|
|
* Other overflow bugs, such as the expression for N_ILIST overflowing when
|
|
* s_inodes is just over V*_INODES_PER_BLOCK less than the maximum+1, are not
|
|
* fixed yet, because that number of inodes is silly.
|
|
*/
|
|
/* The above comment doesn't all apply now bit_t is long. Overflow is now
|
|
* unlikely, but negative bit counts are now possible (though unlikely)
|
|
* and give silly results.
|
|
*/
|
|
PUBLIC int bitmapsize(nr_bits, block_size)
|
|
bit_t nr_bits;
|
|
int block_size;
|
|
{
|
|
int nr_blocks;
|
|
|
|
nr_blocks = (int) (nr_bits / FS_BITS_PER_BLOCK(block_size));
|
|
if (((bit_t) nr_blocks * FS_BITS_PER_BLOCK(block_size)) < nr_bits) ++nr_blocks;
|
|
return(nr_blocks);
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* conv2 *
|
|
*===========================================================================*/
|
|
PUBLIC unsigned conv2(norm, w)
|
|
int norm; /* TRUE if no swap, FALSE for byte swap */
|
|
int w; /* promotion of 16-bit word to be swapped */
|
|
{
|
|
/* Possibly swap a 16-bit word between 8086 and 68000 byte order. */
|
|
|
|
if (norm) return( (unsigned) w & 0xFFFF);
|
|
return( ((w&BYTE) << 8) | ( (w>>8) & BYTE));
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* conv4 *
|
|
*===========================================================================*/
|
|
PUBLIC long conv4(norm, x)
|
|
int norm; /* TRUE if no swap, FALSE for byte swap */
|
|
long x; /* 32-bit long to be byte swapped */
|
|
{
|
|
/* Possibly swap a 32-bit long between 8086 and 68000 byte order. */
|
|
|
|
unsigned lo, hi;
|
|
long l;
|
|
|
|
if (norm) return(x); /* byte order was already ok */
|
|
lo = conv2(FALSE, (int) x & 0xFFFF); /* low-order half, byte swapped */
|
|
hi = conv2(FALSE, (int) (x>>16) & 0xFFFF); /* high-order half, swapped */
|
|
l = ( (long) lo <<16) | hi;
|
|
return(l);
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* conv_inode *
|
|
*===========================================================================*/
|
|
PUBLIC void conv_inode(rip, dip, dip2, rw_flag, magic)
|
|
register struct inode *rip; /* pointer to the in-core inode struct */
|
|
register d1_inode *dip; /* pointer to the V1 on-disk inode struct */
|
|
register d2_inode *dip2; /* pointer to the V2 on-disk inode struct */
|
|
int rw_flag; /* READING or WRITING */
|
|
int magic; /* magic number of file system */
|
|
{
|
|
/* Copy the inode from the disk block to the in-core table or vice versa.
|
|
* If the fourth parameter below is FALSE, the bytes are swapped.
|
|
*/
|
|
switch (magic) {
|
|
case SUPER_MAGIC: old_icopy(rip, dip, rw_flag, TRUE); break;
|
|
case SUPER_REV: old_icopy(rip, dip, rw_flag, FALSE); break;
|
|
case SUPER_V3:
|
|
case SUPER_V2: new_icopy(rip, dip2, rw_flag, TRUE); break;
|
|
case SUPER_V2_REV: new_icopy(rip, dip2, rw_flag, FALSE); break;
|
|
}
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* old_icopy *
|
|
*===========================================================================*/
|
|
PUBLIC void old_icopy(rip, dip, direction, norm)
|
|
register struct inode *rip; /* pointer to the in-core inode struct */
|
|
register d1_inode *dip; /* pointer to the d1_inode inode struct */
|
|
int direction; /* READING (from disk) or WRITING (to disk) */
|
|
int norm; /* TRUE = do not swap bytes; FALSE = swap */
|
|
|
|
{
|
|
/* 4 different on-disk inode layouts are supported, one for each combination
|
|
* of V1.x/V2.x * bytes-swapped/not-swapped. When an inode is read or written
|
|
* this routine handles the conversions so that the information in the inode
|
|
* table is independent of the disk structure from which the inode came.
|
|
* The old_icopy routine copies to and from V1 disks.
|
|
*/
|
|
|
|
int i;
|
|
|
|
if (direction == READING) {
|
|
/* Copy V1.x inode to the in-core table, swapping bytes if need be. */
|
|
rip->i_mode = conv2(norm, dip->d1_mode);
|
|
rip->i_uid = conv2(norm,dip->d1_uid );
|
|
rip->i_size = conv4(norm,dip->d1_size);
|
|
rip->i_mtime = conv4(norm,dip->d1_mtime);
|
|
rip->i_atime = 0;
|
|
rip->i_ctime = 0;
|
|
rip->i_nlinks = (nlink_t) dip->d1_nlinks; /* 1 char */
|
|
rip->i_gid = (gid_t) dip->d1_gid; /* 1 char */
|
|
rip->i_ndzones = V1_NR_DZONES;
|
|
rip->i_nindirs = V1_INDIRECTS;
|
|
for (i = 0; i < V1_NR_TZONES; i++)
|
|
rip->i_zone[i] = conv2(norm, (int) dip->d1_zone[i]);
|
|
} else {
|
|
/* Copying V1.x inode to disk from the in-core table. */
|
|
dip->d1_mode = conv2(norm,rip->i_mode);
|
|
dip->d1_uid = conv2(norm,rip->i_uid );
|
|
dip->d1_size = conv4(norm,rip->i_size);
|
|
dip->d1_mtime = conv4(norm,rip->i_mtime);
|
|
dip->d1_nlinks = (nlink_t) rip->i_nlinks; /* 1 char */
|
|
dip->d1_gid = (gid_t) rip->i_gid; /* 1 char */
|
|
for (i = 0; i < V1_NR_TZONES; i++)
|
|
dip->d1_zone[i] = conv2(norm, (int) rip->i_zone[i]);
|
|
}
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* new_icopy *
|
|
*===========================================================================*/
|
|
PUBLIC void new_icopy(rip, dip, direction, norm)
|
|
register struct inode *rip; /* pointer to the in-core inode struct */
|
|
register d2_inode *dip; /* pointer to the d2_inode struct */
|
|
int direction; /* READING (from disk) or WRITING (to disk) */
|
|
int norm; /* TRUE = do not swap bytes; FALSE = swap */
|
|
|
|
{
|
|
/* Same as old_icopy, but to/from V2 disk layout. */
|
|
|
|
int i;
|
|
|
|
if (direction == READING) {
|
|
/* Copy V2.x inode to the in-core table, swapping bytes if need be. */
|
|
rip->i_mode = conv2(norm,dip->d2_mode);
|
|
rip->i_uid = conv2(norm,dip->d2_uid );
|
|
rip->i_nlinks = conv2(norm,(int) dip->d2_nlinks);
|
|
rip->i_gid = conv2(norm,(int) dip->d2_gid );
|
|
rip->i_size = conv4(norm,dip->d2_size);
|
|
rip->i_atime = conv4(norm,dip->d2_atime);
|
|
rip->i_ctime = conv4(norm,dip->d2_ctime);
|
|
rip->i_mtime = conv4(norm,dip->d2_mtime);
|
|
rip->i_ndzones = V2_NR_DZONES;
|
|
rip->i_nindirs = V2_INDIRECTS(rip->i_sp->s_block_size);
|
|
for (i = 0; i < V2_NR_TZONES; i++)
|
|
rip->i_zone[i] = conv4(norm, (long) dip->d2_zone[i]);
|
|
} else {
|
|
/* Copying V2.x inode to disk from the in-core table. */
|
|
dip->d2_mode = conv2(norm,rip->i_mode);
|
|
dip->d2_uid = conv2(norm,rip->i_uid );
|
|
dip->d2_nlinks = conv2(norm,rip->i_nlinks);
|
|
dip->d2_gid = conv2(norm,rip->i_gid );
|
|
dip->d2_size = conv4(norm,rip->i_size);
|
|
dip->d2_atime = conv4(norm,rip->i_atime);
|
|
dip->d2_ctime = conv4(norm,rip->i_ctime);
|
|
dip->d2_mtime = conv4(norm,rip->i_mtime);
|
|
for (i = 0; i < V2_NR_TZONES; i++)
|
|
dip->d2_zone[i] = conv4(norm, (long) rip->i_zone[i]);
|
|
}
|
|
}
|