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
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
|
/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2004 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
#include "fuse_i.h"
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#ifdef KERNEL_2_6
#include <linux/parser.h>
#include <linux/statfs.h>
#else
#include "compat/parser.h"
#endif
static int user_allow_other;
static kmem_cache_t *fuse_inode_cachep;
#ifdef KERNEL_2_6
#include <linux/moduleparam.h>
module_param(user_allow_other, int, 0);
#else
MODULE_PARM(user_allow_other, "i");
#endif
MODULE_PARM_DESC(user_allow_other, "Allow non root user to specify the \"allow_other\" mount option");
#define FUSE_SUPER_MAGIC 0x65735546
#ifndef KERNEL_2_6
#define kstatfs statfs
#endif
#ifndef FS_SAFE
#define FS_SAFE 0
#endif
struct fuse_mount_data {
int fd;
unsigned int rootmode;
unsigned int uid;
unsigned int flags;
unsigned int max_read;
};
struct fuse_inode *fuse_inode_alloc(void)
{
struct fuse_inode *fi;
fi = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
if (fi) {
memset(fi, 0, sizeof(*fi));
fi->forget_req = fuse_request_alloc();
if (!fi->forget_req) {
kmem_cache_free(fuse_inode_cachep, fi);
fi = NULL;
} else
init_rwsem(&fi->write_sem);
}
return fi;
}
static void fuse_inode_free(struct fuse_inode *fi)
{
kmem_cache_free(fuse_inode_cachep, fi);
}
static void fuse_read_inode(struct inode *inode)
{
/* No op */
}
void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, ino_t ino,
int version)
{
struct fuse_forget_in *inarg = &req->misc.forget_in;
inarg->version = version;
req->in.h.opcode = FUSE_FORGET;
req->in.h.ino = ino;
req->in.numargs = 1;
req->in.args[0].size = sizeof(struct fuse_forget_in);
req->in.args[0].value = inarg;
request_send_noreply(fc, req);
}
static void fuse_clear_inode(struct inode *inode)
{
struct fuse_conn *fc = INO_FC(inode);
struct fuse_inode *fi = INO_FI(inode);
if (fi) {
if (fc == NULL)
fuse_request_free(fi->forget_req);
else
fuse_send_forget(fc, fi->forget_req, inode->i_ino,
inode->i_version);
fuse_inode_free(fi);
}
}
static void fuse_put_super(struct super_block *sb)
{
struct fuse_conn *fc = SB_FC(sb);
spin_lock(&fuse_lock);
fc->sb = NULL;
fc->uid = 0;
fc->flags = 0;
/* Flush all readers on this fs */
wake_up_all(&fc->waitq);
fuse_release_conn(fc);
SB_FC(sb) = NULL;
spin_unlock(&fuse_lock);
}
static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
{
stbuf->f_type = FUSE_SUPER_MAGIC;
stbuf->f_bsize = attr->bsize;
stbuf->f_blocks = attr->blocks;
stbuf->f_bfree = attr->bfree;
stbuf->f_bavail = attr->bavail;
stbuf->f_files = attr->files;
stbuf->f_ffree = attr->ffree;
stbuf->f_namelen = attr->namelen;
/* fsid is left zero */
}
static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
{
struct fuse_conn *fc = SB_FC(sb);
struct fuse_req *req;
struct fuse_statfs_out outarg;
int err;
req = fuse_get_request(fc);
if (!req)
return -ERESTARTSYS;
req->in.numargs = 0;
req->in.h.opcode = FUSE_STATFS;
req->out.numargs = 1;
req->out.args[0].size = sizeof(outarg);
req->out.args[0].value = &outarg;
request_send(fc, req);
err = req->out.h.error;
if (!err)
convert_fuse_statfs(buf, &outarg.st);
fuse_put_request(fc, req);
return err;
}
enum { opt_fd, opt_rootmode, opt_uid, opt_default_permissions,
opt_allow_other, opt_kernel_cache, opt_large_read, opt_direct_io,
opt_max_read, opt_err };
static match_table_t tokens = {
{opt_fd, "fd=%u"},
{opt_rootmode, "rootmode=%o"},
{opt_uid, "uid=%u"},
{opt_default_permissions, "default_permissions"},
{opt_allow_other, "allow_other"},
{opt_kernel_cache, "kernel_cache"},
{opt_large_read, "large_read"},
{opt_direct_io, "direct_io"},
{opt_max_read, "max_read" },
{opt_err, NULL}
};
static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
{
char *p;
memset(d, 0, sizeof(struct fuse_mount_data));
d->fd = -1;
d->max_read = ~0;
while ((p = strsep(&opt, ",")) != NULL) {
int token;
int value;
substring_t args[MAX_OPT_ARGS];
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case opt_fd:
if (match_int(&args[0], &value))
return 0;
d->fd = value;
break;
case opt_rootmode:
if (match_octal(&args[0], &value))
return 0;
d->rootmode = value;
break;
case opt_uid:
if (match_int(&args[0], &value))
return 0;
d->uid = value;
break;
case opt_default_permissions:
d->flags |= FUSE_DEFAULT_PERMISSIONS;
break;
case opt_allow_other:
d->flags |= FUSE_ALLOW_OTHER;
break;
case opt_kernel_cache:
d->flags |= FUSE_KERNEL_CACHE;
break;
case opt_large_read:
d->flags |= FUSE_LARGE_READ;
break;
case opt_direct_io:
d->flags |= FUSE_DIRECT_IO;
break;
case opt_max_read:
if (match_int(&args[0], &value))
return 0;
d->max_read = value;
break;
default:
return 0;
}
}
if (d->fd == -1)
return 0;
return 1;
}
static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
{
struct fuse_conn *fc = SB_FC(mnt->mnt_sb);
seq_printf(m, ",uid=%u", fc->uid);
if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
seq_puts(m, ",default_permissions");
if (fc->flags & FUSE_ALLOW_OTHER)
seq_puts(m, ",allow_other");
if (fc->flags & FUSE_KERNEL_CACHE)
seq_puts(m, ",kernel_cache");
if (fc->flags & FUSE_LARGE_READ)
seq_puts(m, ",large_read");
if (fc->flags & FUSE_DIRECT_IO)
seq_puts(m, ",direct_io");
if (fc->max_read != ~0)
seq_printf(m, ",max_read=%u", fc->max_read);
return 0;
}
static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
{
struct fuse_conn *fc;
struct inode *ino;
ino = file->f_dentry->d_inode;
if (!ino || !proc_fuse_dev || proc_fuse_dev->low_ino != ino->i_ino) {
printk("FUSE: bad communication file descriptor\n");
return NULL;
}
fc = file->private_data;
if (fc->sb != NULL) {
printk("fuse_read_super: connection already mounted\n");
return NULL;
}
fc->sb = sb;
return fc;
}
static struct inode *get_root_inode(struct super_block *sb, unsigned int mode)
{
struct fuse_attr attr;
memset(&attr, 0, sizeof(attr));
attr.mode = mode;
return fuse_iget(sb, 1, 0, &attr, 0);
}
#ifdef KERNEL_2_6
static struct dentry *fuse_get_dentry(struct super_block *sb, void *vobjp)
{
__u32 *objp = vobjp;
unsigned long ino = objp[0];
__u32 generation = objp[1];
struct inode *inode;
struct dentry *entry;
if (ino == 0)
return ERR_PTR(-ESTALE);
inode = ilookup(sb, ino);
if (!inode || inode->i_generation != generation)
return ERR_PTR(-ESTALE);
entry = d_alloc_anon(inode);
if (!entry) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
return entry;
}
static struct export_operations fuse_export_operations = {
.get_dentry = fuse_get_dentry,
};
#endif
static struct super_operations fuse_super_operations = {
.read_inode = fuse_read_inode,
.clear_inode = fuse_clear_inode,
.put_super = fuse_put_super,
.statfs = fuse_statfs,
.show_options = fuse_show_options,
};
static int fuse_read_super(struct super_block *sb, void *data, int silent)
{
struct fuse_conn *fc;
struct inode *root;
struct fuse_mount_data d;
struct file *file;
if (!parse_fuse_opt((char *) data, &d))
return -EINVAL;
if (!user_allow_other && (d.flags & FUSE_ALLOW_OTHER) &&
current->uid != 0)
return -EPERM;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = FUSE_SUPER_MAGIC;
sb->s_op = &fuse_super_operations;
sb->s_maxbytes = MAX_LFS_FILESIZE;
#ifdef KERNEL_2_6
sb->s_export_op = &fuse_export_operations;
#endif
file = fget(d.fd);
if (!file)
return -EINVAL;
spin_lock(&fuse_lock);
fc = get_conn(file, sb);
spin_unlock(&fuse_lock);
fput(file);
if (fc == NULL)
return -EINVAL;
fc->flags = d.flags;
fc->uid = d.uid;
fc->max_read = d.max_read;
fc->max_write = FUSE_MAX_IN / 2;
/* fc is needed in fuse_init_file_inode which could be called
from get_root_inode */
SB_FC(sb) = fc;
root = get_root_inode(sb, d.rootmode);
if (root == NULL) {
printk("fuse_read_super: failed to get root inode\n");
goto err;
}
sb->s_root = d_alloc_root(root);
if (!sb->s_root) {
iput(root);
goto err;
}
return 0;
err:
spin_lock(&fuse_lock);
fc->sb = NULL;
fuse_release_conn(fc);
spin_unlock(&fuse_lock);
SB_FC(sb) = NULL;
return -EINVAL;
}
#ifdef KERNEL_2_6
static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *raw_data)
{
return get_sb_nodev(fs_type, flags, raw_data, fuse_read_super);
}
static struct file_system_type fuse_fs_type = {
.owner = THIS_MODULE,
.name = "fuse",
.get_sb = fuse_get_sb,
.kill_sb = kill_anon_super,
.fs_flags = FS_SAFE,
};
#else
static struct super_block *fuse_read_super_compat(struct super_block *sb,
void *data, int silent)
{
int err = fuse_read_super(sb, data, silent);
if (err)
return NULL;
else
return sb;
}
static DECLARE_FSTYPE(fuse_fs_type, "fuse", fuse_read_super_compat, 0);
#endif
int fuse_fs_init()
{
int err;
err = register_filesystem(&fuse_fs_type);
if (err)
printk("fuse: failed to register filesystem\n");
else {
fuse_inode_cachep = kmem_cache_create("fuse_inode",
sizeof(struct fuse_inode),
0, 0, NULL, NULL);
if (!fuse_inode_cachep) {
unregister_filesystem(&fuse_fs_type);
err = -ENOMEM;
}
}
return err;
}
void fuse_fs_cleanup()
{
unregister_filesystem(&fuse_fs_type);
kmem_cache_destroy(fuse_inode_cachep);
}
/*
* Local Variables:
* indent-tabs-mode: t
* c-basic-offset: 8
* End:
*/
|