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#include <sys/param.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <ufs/inode.h>
#include <ufs/fs.h>
#define sblock sb_un.u_sblock
/*
* The super block. We allow enough room for
* a complete disk block.
*/
union {
struct fs u_sblock;
char dummy[SBSIZE];
} sb_un;
read_blocks(dp)
struct dinode *dp;
{
int count;
register int i, n;
char dblock[MAXBSIZE];
count = dp->di_size;
/*
* For each direct block in the file (NDADDR indicates
* the number of direct addresses stored)...
*/
for (i = 0; (i < NDADDR) && (count > 0); i++) {
/*
* Read in the block from disk. Read in count
* bytes or a disk block, whichever is less.
*/
bread(fsbtodb(&sblock, dp->di_db[i]), dblock,
n = min(count, sblock.fs_bsize));
count -= n;
/* process data block ... */
}
/*
* Now start reading the indirect blocks. NIADDR is
* the number of indirect addresses. Recall that
* the first indirect address is singly indirect,
* the second is doubly indirect, an so on.
*/
for (i = 0; (i < NIADDR) && (count > 0); i++)
read_indirect (dp->di_ib[i], i, &count);
}
/*
* read_indirect--read the indirect blocks of the file. The
* level argument indicates our level of indirection; 0 is
* singly indirect, 1 is doubly indirect, and so on.
*/
read_indirect (blkno, level, count)
ino_t blkno;
int *count;
int level;
{
register int i, n;
char dblock[MAXBSIZE];
daddr_t idblk[MAXBSIZE / sizeof(daddr_t)];
/*
* Read in the block from disk.
*/
if (blkno)
bread(fsbtodb(&sblock, blkno), idblk, sblock.fs_bsize);
else
bzero(idblk, sblock.fs_bsize);
/*
* If level is zero, then this block contains disk block
* addresses, since blkno was a singly indirect address.
* If level is non-zero, then this block contains addresses
* of more indirect blocks.
*/
if (level <= 0) {
/*
* For each disk block (the NINDIR macro returns
* the number of indirect addresses in a block)...
*/
for (i = 0; (i < NINDIR(&sblock)) && (*count > 0); i++) {
/*
* Read in the block from disk.
*/
bread(fsbtodb(&sblock, idblk[i]), dblock,
n = min(*count, sblock.fs_bsize));
*count -= n;
/* process data block ... */
}
/*
* Done processing.
*/
return;
}
/*
* Decrement the level we're at.
*/
level--;
/*
* Handle the next level of indirection by calling
* ourselves recursively with each address in this
* block.
*/
for (i = 0; i < NINDIR(&sblock); i++)
read_indirect(idblk[i], level, count);
}
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