100 lines
1.7 KiB
C
100 lines
1.7 KiB
C
/*
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* linux/fs/truncate.c
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*
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* (C) 1991 Linus Torvalds
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*/
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#include <linux/sched.h>
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#include <sys/stat.h>
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static int free_ind(int dev,int block)
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{
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struct buffer_head * bh;
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unsigned short * p;
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int i;
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int block_busy;
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if (!block)
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return 1;
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block_busy = 0;
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if (bh=bread(dev,block)) {
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p = (unsigned short *) bh->b_data;
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for (i=0;i<512;i++,p++)
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if (*p)
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if (free_block(dev,*p)) {
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*p = 0;
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bh->b_dirt = 1;
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} else
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block_busy = 1;
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brelse(bh);
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}
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if (block_busy)
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return 0;
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else
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return free_block(dev,block);
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}
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static int free_dind(int dev,int block)
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{
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struct buffer_head * bh;
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unsigned short * p;
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int i;
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int block_busy;
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if (!block)
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return 1;
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block_busy = 0;
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if (bh=bread(dev,block)) {
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p = (unsigned short *) bh->b_data;
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for (i=0;i<512;i++,p++)
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if (*p)
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if (free_ind(dev,*p)) {
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*p = 0;
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bh->b_dirt = 1;
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} else
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block_busy = 1;
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brelse(bh);
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}
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if (block_busy)
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return 0;
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else
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return free_block(dev,block);
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}
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void truncate(struct m_inode * inode)
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{
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int i;
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int block_busy;
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if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
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S_ISLNK(inode->i_mode)))
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return;
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repeat:
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block_busy = 0;
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for (i=0;i<7;i++)
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if (inode->i_zone[i]) {
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if (free_block(inode->i_dev,inode->i_zone[i]))
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inode->i_zone[i]=0;
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else
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block_busy = 1;
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}
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if (free_ind(inode->i_dev,inode->i_zone[7]))
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inode->i_zone[7] = 0;
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else
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block_busy = 1;
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if (free_dind(inode->i_dev,inode->i_zone[8]))
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inode->i_zone[8] = 0;
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else
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block_busy = 1;
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inode->i_dirt = 1;
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if (block_busy) {
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current->counter = 0;
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schedule();
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goto repeat;
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}
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inode->i_size = 0;
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inode->i_mtime = inode->i_ctime = CURRENT_TIME;
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}
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