47 lines
1.5 KiB
C
47 lines
1.5 KiB
C
/* fslib.c - routines needed by fs and fs utilities */
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#include <minix/config.h> /* for unused stuff in <minix/type.h> :-( */
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#include <limits.h>
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#include <dirent.h>
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#include <assert.h>
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#include <stdlib.h> /* for abort() */
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#include <sys/types.h>
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#include <minix/const.h>
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#include <minix/type.h> /* for unshort :-( */
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#include <minix/minlib.h>
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#include <minix/ipc.h>
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#include "mfs/const.h" /* depends of -I flag in Makefile */
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#include "mfs/type.h" /* ditto */
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#include "mfs/inode.h" /* ditto */
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#include "mfs/super.h"
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#include <minix/fslib.h>
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/* The next routine is copied from fsck.c and mkfs.c... (Re)define some
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* things for consistency. Some things should be done better.
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*/
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/* Convert from bit count to a block count. The usual expression
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*
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* (nr_bits + (1 << BITMAPSHIFT) - 1) >> BITMAPSHIFT
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*
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* doesn't work because of overflow.
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*
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* Other overflow bugs, such as the expression for N_ILIST overflowing when
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* s_inodes is just over V*_INODES_PER_BLOCK less than the maximum+1, are not
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* fixed yet, because that number of inodes is silly.
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*/
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/* The above comment doesn't all apply now bit_t is long. Overflow is now
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* unlikely, but negative bit counts are now possible (though unlikely)
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* and give silly results.
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*/
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int bitmapsize(nr_bits, block_size)
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bit_t nr_bits;
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int block_size;
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{
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int nr_blocks;
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nr_blocks = (int) (nr_bits / FS_BITS_PER_BLOCK(block_size));
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if (((bit_t) nr_blocks * FS_BITS_PER_BLOCK(block_size)) < nr_bits) ++nr_blocks;
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return(nr_blocks);
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}
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