cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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bitmap.c (1110B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * QNX4 file system, Linux implementation.
      4 *
      5 * Version : 0.2.1
      6 *
      7 * Using parts of the xiafs filesystem.
      8 *
      9 * History :
     10 *
     11 * 28-05-1998 by Richard Frowijn : first release.
     12 * 20-06-1998 by Frank Denis : basic optimisations.
     13 * 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap .
     14 * 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) .
     15 */
     16
     17#include <linux/buffer_head.h>
     18#include <linux/bitops.h>
     19#include "qnx4.h"
     20
     21unsigned long qnx4_count_free_blocks(struct super_block *sb)
     22{
     23	int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
     24	int total = 0;
     25	int total_free = 0;
     26	int offset = 0;
     27	int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
     28	struct buffer_head *bh;
     29
     30	while (total < size) {
     31		int bytes = min(size - total, QNX4_BLOCK_SIZE);
     32
     33		if ((bh = sb_bread(sb, start + offset)) == NULL) {
     34			printk(KERN_ERR "qnx4: I/O error in counting free blocks\n");
     35			break;
     36		}
     37		total_free += bytes * BITS_PER_BYTE -
     38				memweight(bh->b_data, bytes);
     39		brelse(bh);
     40		total += bytes;
     41		offset++;
     42	}
     43
     44	return total_free;
     45}