xref: /linux/fs/qnx4/dir.c (revision 2697b79a469b68e3ad3640f55284359c1396278d)
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 
18 static 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 
68 const 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 
76 const struct inode_operations qnx4_dir_inode_operations =
77 {
78 	.lookup		= qnx4_lookup,
79 };
80