1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/*
* linux/fs/affs/dir.c
*
* (c) 1996 Hans-Joachim Widmaier - Rewritten
*
* (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
*
* (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
*
* (C) 1991 Linus Torvalds - minix filesystem
*
* affs directory handling functions
*
*/
#include "affs.h"
static int affs_readdir(struct file *, struct dir_context *);
const struct file_operations affs_dir_operations = {
.read = generic_read_dir,
.llseek = generic_file_llseek,
.iterate = affs_readdir,
.fsync = affs_file_fsync,
};
/*
* directories can handle most operations...
*/
const struct inode_operations affs_dir_inode_operations = {
.create = affs_create,
.lookup = affs_lookup,
.link = affs_link,
.unlink = affs_unlink,
.symlink = affs_symlink,
.mkdir = affs_mkdir,
.rmdir = affs_rmdir,
.rename = affs_rename,
.setattr = affs_notify_change,
};
static int
affs_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct super_block *sb = inode->i_sb;
struct buffer_head *dir_bh = NULL;
struct buffer_head *fh_bh = NULL;
unsigned char *name;
int namelen;
u32 i;
int hash_pos;
int chain_pos;
u32 ino;
int error = 0;
pr_debug("%s(ino=%lu,f_pos=%lx)\n",
__func__, inode->i_ino, (unsigned long)ctx->pos);
if (ctx->pos < 2) {
file->private_data = (void *)0;
if (!dir_emit_dots(file, ctx))
return 0;
}
affs_lock_dir(inode);
chain_pos = (ctx->pos - 2) & 0xffff;
hash_pos = (ctx->pos - 2) >> 16;
if (chain_pos == 0xffff) {
affs_warning(sb, "readdir", "More than 65535 entries in chain");
chain_pos = 0;
hash_pos++;
ctx->pos = ((hash_pos << 16) | chain_pos) + 2;
}
dir_bh = affs_bread(sb, inode->i_ino);
if (!dir_bh)
goto out_unlock_dir;
/* If the directory hasn't changed since the last call to readdir(),
* we can jump directly to where we left off.
*/
ino = (u32)(long)file->private_data;
if (ino && file->f_version == inode->i_version) {
pr_debug("readdir() left off=%d\n", ino);
goto inside;
}
ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
for (i = 0; ino && i < chain_pos; i++) {
fh_bh = affs_bread(sb, ino);
if (!fh_bh) {
affs_error(sb, "readdir","Cannot read block %d", i);
error = -EIO;
goto out_brelse_dir;
}
ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
affs_brelse(fh_bh);
fh_bh = NULL;
}
if (ino)
goto inside;
hash_pos++;
for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
if (!ino)
continue;
ctx->pos = (hash_pos << 16) + 2;
inside:
do {
fh_bh = affs_bread(sb, ino);
if (!fh_bh) {
affs_error(sb, "readdir",
"Cannot read block %d", ino);
break;
}
namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30);
name = AFFS_TAIL(sb, fh_bh)->name + 1;
pr_debug("readdir(): dir_emit(\"%.*s\", "
"ino=%u), hash=%d, f_pos=%x\n",
namelen, name, ino, hash_pos, (u32)ctx->pos);
if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))
goto done;
ctx->pos++;
ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
affs_brelse(fh_bh);
fh_bh = NULL;
} while (ino);
}
done:
file->f_version = inode->i_version;
file->private_data = (void *)(long)ino;
affs_brelse(fh_bh);
out_brelse_dir:
affs_brelse(dir_bh);
out_unlock_dir:
affs_unlock_dir(inode);
return error;
}
|
