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
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
|
#include <sys/sysmacros.h>
#include <sys/vnode.h>
#include "config.h"
void *rootdir = NULL;
EXPORT_SYMBOL(rootdir);
static vtype_t
vn_get_sol_type(umode_t mode)
{
if (S_ISREG(mode))
return VREG;
if (S_ISDIR(mode))
return VDIR;
if (S_ISCHR(mode))
return VCHR;
if (S_ISBLK(mode))
return VBLK;
if (S_ISFIFO(mode))
return VFIFO;
if (S_ISLNK(mode))
return VLNK;
if (S_ISSOCK(mode))
return VSOCK;
if (S_ISCHR(mode))
return VCHR;
return VNON;
} /* vn_get_sol_type() */
int
vn_open(const char *path, int seg, int flags, int mode,
vnode_t **vpp, int x1, void *x2)
{
struct file *fp;
struct kstat stat;
int rc, saved_umask, flags_rw;
vnode_t *vp;
BUG_ON(seg != UIO_SYSSPACE);
BUG_ON(!vpp);
*vpp = NULL;
if (!(flags & FCREAT) && (flags & FWRITE))
flags |= FEXCL;
flags_rw = flags & (FWRITE | FREAD);
flags &= ~(FWRITE | FREAD);
switch (flags_rw) {
case FWRITE: flags |= O_WRONLY;
case FREAD: flags |= O_RDONLY;
case (FWRITE | FREAD): flags |= O_RDWR;
}
if (flags & FCREAT)
saved_umask = xchg(¤t->fs->umask, 0);
fp = filp_open(path, flags, mode);
if (flags & FCREAT)
(void)xchg(¤t->fs->umask, saved_umask);
if (IS_ERR(fp))
return PTR_ERR(fp);
rc = vfs_getattr(fp->f_vfsmnt, fp->f_dentry, &stat);
if (rc) {
filp_close(fp, 0);
return rc;
}
vp = kmalloc(sizeof(vnode_t), GFP_ATOMIC);
if (!vp) {
filp_close(fp, 0);
return -ENOMEM;
}
vp->v_type = vn_get_sol_type(stat.mode);
vp->v_fp = fp;
*vpp = vp;
return 0;
} /* vn_open() */
EXPORT_SYMBOL(vn_open);
int
vn_openat(const char *path, int seg, int flags, int mode,
vnode_t **vpp, int x1, void *x2, vnode_t *vp, int fd)
{
char *realpath;
int rc;
BUG_ON(vp != rootdir);
realpath = kmalloc(strlen(path) + 2, GFP_KERNEL);
if (!realpath)
return -ENOMEM;
sprintf(realpath, "/%s", path);
rc = vn_open(realpath, seg, flags, mode, vpp, x1, x2);
kfree(realpath);
return rc;
} /* vn_openat() */
EXPORT_SYMBOL(vn_openat);
int
vn_rdwr(uio_rw_t uio, vnode_t *vp, void *addr, ssize_t len, offset_t off,
int seg, int x1, rlim64_t x2, void *x3, ssize_t *residp)
{
loff_t offset;
mm_segment_t saved_fs;
struct file *fp;
int rc;
BUG_ON(!(uio == UIO_WRITE || uio == UIO_READ));
BUG_ON(!vp);
BUG_ON(!vp->v_fp);
BUG_ON(seg != UIO_SYSSPACE);
BUG_ON(x1 != 0);
BUG_ON(x2 != RLIM64_INFINITY);
offset = off;
fp = vp->v_fp;
/* Writable user data segment must be briefly increased for this
* process so we can use the user space read call paths to write
* in to memory allocated by the kernel. */
saved_fs = get_fs();
set_fs(get_ds());
if (uio & UIO_WRITE)
rc = vfs_write(fp, addr, len, &offset);
else
rc = vfs_read(fp, addr, len, &offset);
set_fs(saved_fs);
if (rc < 0)
return rc;
if (residp) {
*residp = len - rc;
} else {
if (rc != len)
return -EIO;
}
return 0;
} /* vn_rdwr() */
EXPORT_SYMBOL(vn_rdwr);
int
vn_close(vnode_t *vp, int flags, int x1, int x2, void *x3, void *x4)
{
int rc;
BUG_ON(!vp);
BUG_ON(!vp->v_fp);
rc = filp_close(vp->v_fp, 0);
kfree(vp);
return rc;
} /* vn_close() */
EXPORT_SYMBOL(vn_close);
static struct dentry *lookup_hash(struct nameidata *nd)
{
return __lookup_hash(&nd->last, nd->dentry, nd);
} /* lookup_hash() */
/* Modified do_unlinkat() from linux/fs/namei.c, only uses exported symbols */
int
vn_remove(const char *path, int seg, int flags)
{
struct dentry *dentry;
struct nameidata nd;
struct inode *inode = NULL;
int rc = 0;
BUG_ON(seg != UIO_SYSSPACE);
BUG_ON(flags != RMFILE);
rc = path_lookup(path, LOOKUP_PARENT, &nd);
if (rc)
goto exit;
rc = -EISDIR;
if (nd.last_type != LAST_NORM)
goto exit1;
mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_hash(&nd);
rc = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
/* Why not before? Because we want correct rc value */
if (nd.last.name[nd.last.len])
goto slashes;
inode = dentry->d_inode;
if (inode)
atomic_inc(&inode->i_count);
rc = vfs_unlink(nd.dentry->d_inode, dentry);
exit2:
dput(dentry);
}
mutex_unlock(&nd.dentry->d_inode->i_mutex);
if (inode)
iput(inode); /* truncate the inode here */
exit1:
path_release(&nd);
exit:
return rc;
slashes:
rc = !dentry->d_inode ? -ENOENT :
S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR;
goto exit2;
} /* vn_remove() */
EXPORT_SYMBOL(vn_remove);
/* Modified do_rename() from linux/fs/namei.c, only uses exported symbols */
int
vn_rename(const char *oldname, const char *newname, int x1)
{
struct dentry * old_dir, * new_dir;
struct dentry * old_dentry, *new_dentry;
struct dentry * trap;
struct nameidata oldnd, newnd;
int rc = 0;
rc = path_lookup(oldname, LOOKUP_PARENT, &oldnd);
if (rc)
goto exit;
rc = path_lookup(newname, LOOKUP_PARENT, &newnd);
if (rc)
goto exit1;
rc = -EXDEV;
if (oldnd.mnt != newnd.mnt)
goto exit2;
old_dir = oldnd.dentry;
rc = -EBUSY;
if (oldnd.last_type != LAST_NORM)
goto exit2;
new_dir = newnd.dentry;
if (newnd.last_type != LAST_NORM)
goto exit2;
trap = lock_rename(new_dir, old_dir);
old_dentry = lookup_hash(&oldnd);
rc = PTR_ERR(old_dentry);
if (IS_ERR(old_dentry))
goto exit3;
/* source must exist */
rc = -ENOENT;
if (!old_dentry->d_inode)
goto exit4;
/* unless the source is a directory trailing slashes give -ENOTDIR */
if (!S_ISDIR(old_dentry->d_inode->i_mode)) {
rc = -ENOTDIR;
if (oldnd.last.name[oldnd.last.len])
goto exit4;
if (newnd.last.name[newnd.last.len])
goto exit4;
}
/* source should not be ancestor of target */
rc = -EINVAL;
if (old_dentry == trap)
goto exit4;
new_dentry = lookup_hash(&newnd);
rc = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
goto exit4;
/* target should not be an ancestor of source */
rc = -ENOTEMPTY;
if (new_dentry == trap)
goto exit5;
rc = vfs_rename(old_dir->d_inode, old_dentry,
new_dir->d_inode, new_dentry);
exit5:
dput(new_dentry);
exit4:
dput(old_dentry);
exit3:
unlock_rename(new_dir, old_dir);
exit2:
path_release(&newnd);
exit1:
path_release(&oldnd);
exit:
return rc;
}
EXPORT_SYMBOL(vn_rename);
int
vn_getattr(vnode_t *vp, vattr_t *vap, int flags, void *x3, void *x4)
{
struct file *fp;
struct kstat stat;
int rc;
BUG_ON(!vp);
BUG_ON(!vp->v_fp);
BUG_ON(!vap);
fp = vp->v_fp;
rc = vfs_getattr(fp->f_vfsmnt, fp->f_dentry, &stat);
if (rc)
return rc;
vap->va_type = vn_get_sol_type(stat.mode);
vap->va_mode = stat.mode;
vap->va_uid = stat.uid;
vap->va_gid = stat.gid;
vap->va_fsid = 0;
vap->va_nodeid = stat.ino;
vap->va_nlink = stat.nlink;
vap->va_size = stat.size;
vap->va_blocksize = stat.blksize;
vap->va_atime.tv_sec = stat.atime.tv_sec;
vap->va_atime.tv_usec = stat.atime.tv_nsec / NSEC_PER_USEC;
vap->va_mtime.tv_sec = stat.mtime.tv_sec;
vap->va_mtime.tv_usec = stat.mtime.tv_nsec / NSEC_PER_USEC;
vap->va_ctime.tv_sec = stat.ctime.tv_sec;
vap->va_ctime.tv_usec = stat.ctime.tv_nsec / NSEC_PER_USEC;
vap->va_rdev = stat.rdev;
vap->va_blocks = stat.blocks;
return rc;
}
EXPORT_SYMBOL(vn_getattr);
int vn_fsync(vnode_t *vp, int flags, void *x3, void *x4)
{
int datasync = 0;
BUG_ON(!vp);
BUG_ON(!vp->v_fp);
if (flags & FDSYNC)
datasync = 1;
return file_fsync(vp->v_fp, vp->v_fp->f_dentry, datasync);
} /* vn_fsync() */
EXPORT_SYMBOL(vn_fsync);
|