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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
/*
* QNX4 file system, Linux implementation.
*
* Version : 0.2.1
*
* Using parts of the xiafs filesystem.
*
* History :
*
* 01-06-1998 by Richard Frowijn : first release.
* 21-06-1998 by Frank Denis : dcache support, fixed error codes.
* 04-07-1998 by Frank Denis : first step for rmdir/unlink.
*/
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include "qnx4.h"
/*
* check if the filename is correct. For some obscure reason, qnx writes a
* new file twice in the directory entry, first with all possible options at 0
* and for a second time the way it is, they want us not to access the qnx
* filesystem when whe are using linux.
*/
static int qnx4_match(int len, const char *name,
struct buffer_head *bh, unsigned long *offset)
{
struct qnx4_inode_entry *de;
int namelen, thislen;
if (bh == NULL) {
printk("qnx4: matching unassigned buffer !\n");
return 0;
}
de = (struct qnx4_inode_entry *) (bh->b_data + *offset);
*offset += QNX4_DIR_ENTRY_SIZE;
if ((de->di_status & QNX4_FILE_LINK) != 0) {
namelen = QNX4_NAME_MAX;
} else {
namelen = QNX4_SHORT_NAME_MAX;
}
/* "" means "." ---> so paths like "/usr/lib//libc.a" work */
if (!len && (de->di_fname[0] == '.') && (de->di_fname[1] == '\0')) {
return 1;
}
thislen = strlen( de->di_fname );
if ( thislen > namelen )
thislen = namelen;
if (len != thislen) {
return 0;
}
if (strncmp(name, de->di_fname, len) == 0) {
if ((de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)) != 0) {
return 1;
}
}
return 0;
}
static struct buffer_head *qnx4_find_entry(int len, struct inode *dir,
const char *name, struct qnx4_inode_entry **res_dir, int *ino)
{
unsigned long block, offset, blkofs;
struct buffer_head *bh;
*res_dir = NULL;
if (!dir->i_sb) {
printk("qnx4: no superblock on dir.\n");
return NULL;
}
bh = NULL;
block = offset = blkofs = 0;
while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) {
if (!bh) {
bh = qnx4_bread(dir, blkofs, 0);
if (!bh) {
blkofs++;
continue;
}
}
*res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset);
if (qnx4_match(len, name, bh, &offset)) {
block = qnx4_block_map( dir, blkofs );
*ino = block * QNX4_INODES_PER_BLOCK +
(offset / QNX4_DIR_ENTRY_SIZE) - 1;
return bh;
}
if (offset < bh->b_size) {
continue;
}
brelse(bh);
bh = NULL;
offset = 0;
blkofs++;
}
brelse(bh);
*res_dir = NULL;
return NULL;
}
struct dentry * qnx4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
int ino;
struct qnx4_inode_entry *de;
struct qnx4_link_info *lnk;
struct buffer_head *bh;
const char *name = dentry->d_name.name;
int len = dentry->d_name.len;
struct inode *foundinode = NULL;
lock_kernel();
if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino)))
goto out;
/* The entry is linked, let's get the real info */
if ((de->di_status & QNX4_FILE_LINK) == QNX4_FILE_LINK) {
lnk = (struct qnx4_link_info *) de;
ino = (le32_to_cpu(lnk->dl_inode_blk) - 1) *
QNX4_INODES_PER_BLOCK +
lnk->dl_inode_ndx;
}
brelse(bh);
foundinode = qnx4_iget(dir->i_sb, ino);
if (IS_ERR(foundinode)) {
unlock_kernel();
QNX4DEBUG(("qnx4: lookup->iget -> error %ld\n",
PTR_ERR(foundinode)));
return ERR_CAST(foundinode);
}
out:
unlock_kernel();
d_add(dentry, foundinode);
return NULL;
}
#ifdef CONFIG_QNX4FS_RW
int qnx4_create(struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
QNX4DEBUG(("qnx4: qnx4_create\n"));
if (dir == NULL) {
return -ENOENT;
}
return -ENOSPC;
}
int qnx4_rmdir(struct inode *dir, struct dentry *dentry)
{
struct buffer_head *bh;
struct qnx4_inode_entry *de;
struct inode *inode;
int retval;
int ino;
QNX4DEBUG(("qnx4: qnx4_rmdir [%s]\n", dentry->d_name.name));
lock_kernel();
bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
&de, &ino);
if (bh == NULL) {
unlock_kernel();
return -ENOENT;
}
inode = dentry->d_inode;
if (inode->i_ino != ino) {
retval = -EIO;
goto end_rmdir;
}
#if 0
if (!empty_dir(inode)) {
retval = -ENOTEMPTY;
goto end_rmdir;
}
#endif
if (inode->i_nlink != 2) {
QNX4DEBUG(("empty directory has nlink!=2 (%d)\n", inode->i_nlink));
}
QNX4DEBUG(("qnx4: deleting directory\n"));
de->di_status = 0;
memset(de->di_fname, 0, sizeof de->di_fname);
de->di_mode = 0;
mark_buffer_dirty_inode(bh, dir);
clear_nlink(inode);
mark_inode_dirty(inode);
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
inode_dec_link_count(dir);
retval = 0;
end_rmdir:
brelse(bh);
unlock_kernel();
return retval;
}
int qnx4_unlink(struct inode *dir, struct dentry *dentry)
{
struct buffer_head *bh;
struct qnx4_inode_entry *de;
struct inode *inode;
int retval;
int ino;
QNX4DEBUG(("qnx4: qnx4_unlink [%s]\n", dentry->d_name.name));
lock_kernel();
bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name,
&de, &ino);
if (bh == NULL) {
unlock_kernel();
return -ENOENT;
}
inode = dentry->d_inode;
if (inode->i_ino != ino) {
retval = -EIO;
goto end_unlink;
}
retval = -EPERM;
if (!inode->i_nlink) {
QNX4DEBUG(("Deleting nonexistent file (%s:%lu), %d\n",
inode->i_sb->s_id,
inode->i_ino, inode->i_nlink));
inode->i_nlink = 1;
}
de->di_status = 0;
memset(de->di_fname, 0, sizeof de->di_fname);
de->di_mode = 0;
mark_buffer_dirty_inode(bh, dir);
dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
mark_inode_dirty(dir);
inode->i_ctime = dir->i_ctime;
inode_dec_link_count(inode);
retval = 0;
end_unlink:
unlock_kernel();
brelse(bh);
return retval;
}
#endif
|
