46 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			46 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * QNX4 file system, Linux implementation.
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|  *
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|  * Version : 0.2.1
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|  *
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|  * Using parts of the xiafs filesystem.
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|  *
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|  * History :
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|  *
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|  * 28-05-1998 by Richard Frowijn : first release.
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|  * 20-06-1998 by Frank Denis : basic optimisations.
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|  * 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap .
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|  * 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) .
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|  */
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| 
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| #include <linux/buffer_head.h>
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| #include <linux/bitops.h>
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| #include "qnx4.h"
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| 
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| unsigned long qnx4_count_free_blocks(struct super_block *sb)
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| {
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| 	int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
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| 	int total = 0;
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| 	int total_free = 0;
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| 	int offset = 0;
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| 	int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
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| 	struct buffer_head *bh;
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| 
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| 	while (total < size) {
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| 		int bytes = min(size - total, QNX4_BLOCK_SIZE);
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| 
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| 		if ((bh = sb_bread(sb, start + offset)) == NULL) {
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| 			printk(KERN_ERR "qnx4: I/O error in counting free blocks\n");
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| 			break;
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| 		}
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| 		total_free += bytes * BITS_PER_BYTE -
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| 				memweight(bh->b_data, bytes);
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| 		brelse(bh);
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| 		total += bytes;
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| 		offset++;
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| 	}
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| 
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| 	return total_free;
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| }
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