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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};
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/*
19 * A qnx4 directory entry is an inode entry or link info
20 * depending on the status field in the last byte. The
21 * first byte is where the name start either way, and a
22 * zero means it's empty.
23 *
24 * Also, due to a bug in gcc, we don't want to use the
25 * real (differently sized) name arrays in the inode and
26 * link entries, but always the 'de_name[]' one in the
27 * fake struct entry.
28 *
29 * See
30 *
31 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578#c6
32 *
33 * for details, but basically gcc will take the size of the
34 * 'name' array from one of the used union entries randomly.
35 *
36 * This use of 'de_name[]' (48 bytes) avoids the false positive
37 * warnings that would happen if gcc decides to use 'inode.di_name'
38 * (16 bytes) even when the pointer and size were to come from
39 * 'link.dl_name' (48 bytes).
40 *
41 * In all cases the actual name pointer itself is the same, it's
42 * only the gcc internal 'what is the size of this field' logic
43 * that can get confused.
44 */
45union qnx4_directory_entry {
46 struct {
47 const char de_name[48];
48 u8 de_pad[15];
49 u8 de_status;
50 };
51 struct qnx4_inode_entry inode;
52 struct qnx4_link_info link;
53};
54
55static int qnx4_readdir(struct file *file, struct dir_context *ctx)
56{
57 struct inode *inode = file_inode(file);
58 unsigned int offset;
59 struct buffer_head *bh;
60 unsigned long blknum;
61 int ix, ino;
62 int size;
63
64 QNX4DEBUG((KERN_INFO "qnx4_readdir:i_size = %ld\n", (long) inode->i_size));
65 QNX4DEBUG((KERN_INFO "pos = %ld\n", (long) ctx->pos));
66
67 while (ctx->pos < inode->i_size) {
68 blknum = qnx4_block_map(inode, ctx->pos >> QNX4_BLOCK_SIZE_BITS);
69 bh = sb_bread(inode->i_sb, blknum);
70 if (bh == NULL) {
71 printk(KERN_ERR "qnx4_readdir: bread failed (%ld)\n", blknum);
72 return 0;
73 }
74 ix = (ctx->pos >> QNX4_DIR_ENTRY_SIZE_BITS) % QNX4_INODES_PER_BLOCK;
75 for (; ix < QNX4_INODES_PER_BLOCK; ix++, ctx->pos += QNX4_DIR_ENTRY_SIZE) {
76 union qnx4_directory_entry *de;
77
78 offset = ix * QNX4_DIR_ENTRY_SIZE;
79 de = (union qnx4_directory_entry *) (bh->b_data + offset);
80
81 if (!de->de_name[0])
82 continue;
83 if (!(de->de_status & (QNX4_FILE_USED|QNX4_FILE_LINK)))
84 continue;
85 if (!(de->de_status & QNX4_FILE_LINK)) {
86 size = sizeof(de->inode.di_fname);
87 ino = blknum * QNX4_INODES_PER_BLOCK + ix - 1;
88 } else {
89 size = sizeof(de->link.dl_fname);
90 ino = ( le32_to_cpu(de->link.dl_inode_blk) - 1 ) *
91 QNX4_INODES_PER_BLOCK +
92 de->link.dl_inode_ndx;
93 }
94 size = strnlen(de->de_name, size);
95 QNX4DEBUG((KERN_INFO "qnx4_readdir:%.*s\n", size, name));
96 if (!dir_emit(ctx, de->de_name, size, ino, DT_UNKNOWN)) {
97 brelse(bh);
98 return 0;
99 }
100 }
101 brelse(bh);
102 }
103 return 0;
104}
105
106const struct file_operations qnx4_dir_operations =
107{
108 .llseek = generic_file_llseek,
109 .read = generic_read_dir,
110 .iterate_shared = qnx4_readdir,
111 .fsync = generic_file_fsync,
112};
113
114const struct inode_operations qnx4_dir_inode_operations =
115{
116 .lookup = qnx4_lookup,
117};