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 : Linux 2.1.99+ & dcache support.
13 */
14
15#include <linux/buffer_head.h>
16#include "qnx4.h"
17
18static int qnx4_readdir(struct file *file, struct dir_context *ctx)
19{
20	struct inode *inode = file_inode(file);
21	unsigned int offset;
22	struct buffer_head *bh;
23	unsigned long blknum;
24	int ix, ino;
25	int size;
26
27	QNX4DEBUG((KERN_INFO "qnx4_readdir:i_size = %ld\n", (long) inode->i_size));
28	QNX4DEBUG((KERN_INFO "pos                 = %ld\n", (long) ctx->pos));
29
30	while (ctx->pos < inode->i_size) {
31		blknum = qnx4_block_map(inode, ctx->pos >> QNX4_BLOCK_SIZE_BITS);
32		bh = sb_bread(inode->i_sb, blknum);
33		if (bh == NULL) {
34			printk(KERN_ERR "qnx4_readdir: bread failed (%ld)\n", blknum);
35			return 0;
36		}
37		ix = (ctx->pos >> QNX4_DIR_ENTRY_SIZE_BITS) % QNX4_INODES_PER_BLOCK;
38		for (; ix < QNX4_INODES_PER_BLOCK; ix++, ctx->pos += QNX4_DIR_ENTRY_SIZE) {
39			union qnx4_directory_entry *de;
40			const char *fname;
41
42			offset = ix * QNX4_DIR_ENTRY_SIZE;
43			de = (union qnx4_directory_entry *) (bh->b_data + offset);
44
45			fname = get_entry_fname(de, &size);
46			if (!fname)
47				continue;
48
49			if (!(de->de_status & QNX4_FILE_LINK)) {
50				ino = blknum * QNX4_INODES_PER_BLOCK + ix - 1;
51			} else {
52				ino = ( le32_to_cpu(de->link.dl_inode_blk) - 1 ) *
53					QNX4_INODES_PER_BLOCK +
54					de->link.dl_inode_ndx;
55			}
56
57			QNX4DEBUG((KERN_INFO "qnx4_readdir:%.*s\n", size, fname));
58			if (!dir_emit(ctx, fname, size, ino, DT_UNKNOWN)) {
59				brelse(bh);
60				return 0;
61			}
62		}
63		brelse(bh);
64	}
65	return 0;
66}
67
68const struct file_operations qnx4_dir_operations =
69{
70	.llseek		= generic_file_llseek,
71	.read		= generic_read_dir,
72	.iterate_shared	= qnx4_readdir,
73	.fsync		= generic_file_fsync,
74};
75
76const struct inode_operations qnx4_dir_inode_operations =
77{
78	.lookup		= qnx4_lookup,
79};
80