/[fuse_dbi]/fuse/trunk/kernel/inode.c
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Contents of /fuse/trunk/kernel/inode.c

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Revision 5 - (show annotations)
Wed Aug 4 11:40:49 2004 UTC (18 years, 5 months ago) by dpavlin
File MIME type: text/plain
File size: 10113 byte(s)
copy CVS to trunk

1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2004 Miklos Szeredi <miklos@szeredi.hu>
4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7 */
8
9 #include "fuse_i.h"
10
11 #include <linux/pagemap.h>
12 #include <linux/sched.h>
13 #include <linux/slab.h>
14 #include <linux/file.h>
15 #include <linux/mount.h>
16 #include <linux/proc_fs.h>
17 #include <linux/seq_file.h>
18 #ifdef KERNEL_2_6
19 #include <linux/parser.h>
20 #include <linux/statfs.h>
21 #else
22 #include "compat/parser.h"
23 #endif
24
25
26 static int user_allow_other;
27 static kmem_cache_t *fuse_inode_cachep;
28
29 #ifdef KERNEL_2_6
30 #include <linux/moduleparam.h>
31 module_param(user_allow_other, int, 0);
32 #else
33 MODULE_PARM(user_allow_other, "i");
34 #endif
35
36 MODULE_PARM_DESC(user_allow_other, "Allow non root user to specify the \"allow_other\" mount option");
37
38
39 #define FUSE_SUPER_MAGIC 0x65735546
40
41 #ifndef KERNEL_2_6
42 #define kstatfs statfs
43 #endif
44
45 #ifndef FS_SAFE
46 #define FS_SAFE 0
47 #endif
48
49 struct fuse_mount_data {
50 int fd;
51 unsigned int rootmode;
52 unsigned int uid;
53 unsigned int flags;
54 unsigned int max_read;
55 };
56
57 struct fuse_inode *fuse_inode_alloc(void)
58 {
59 struct fuse_inode *fi;
60
61 fi = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
62 if (fi) {
63 memset(fi, 0, sizeof(*fi));
64 fi->forget_req = fuse_request_alloc();
65 if (!fi->forget_req) {
66 kmem_cache_free(fuse_inode_cachep, fi);
67 fi = NULL;
68 } else {
69 init_rwsem(&fi->write_sem);
70 INIT_LIST_HEAD(&fi->write_files);
71 }
72 }
73
74 return fi;
75 }
76
77 static void fuse_inode_free(struct fuse_inode *fi)
78 {
79 BUG_ON(!list_empty(&fi->write_files));
80 if (fi->forget_req)
81 fuse_request_free(fi->forget_req);
82 kmem_cache_free(fuse_inode_cachep, fi);
83 }
84
85 static void fuse_read_inode(struct inode *inode)
86 {
87 /* No op */
88 }
89
90 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, ino_t ino,
91 int version)
92 {
93 struct fuse_forget_in *inarg = &req->misc.forget_in;
94 inarg->version = version;
95 req->in.h.opcode = FUSE_FORGET;
96 req->in.h.ino = ino;
97 req->in.numargs = 1;
98 req->in.args[0].size = sizeof(struct fuse_forget_in);
99 req->in.args[0].value = inarg;
100 request_send_noreply(fc, req);
101 }
102
103 static void fuse_clear_inode(struct inode *inode)
104 {
105 struct fuse_conn *fc = INO_FC(inode);
106 struct fuse_inode *fi = INO_FI(inode);
107
108 if (fi) {
109 if (fc) {
110 fuse_send_forget(fc, fi->forget_req, inode->i_ino,
111 inode->i_version);
112 fi->forget_req = NULL;
113 }
114 fuse_inode_free(fi);
115 }
116 }
117
118 static void fuse_put_super(struct super_block *sb)
119 {
120 struct fuse_conn *fc = SB_FC(sb);
121
122 spin_lock(&fuse_lock);
123 fc->sb = NULL;
124 fc->uid = 0;
125 fc->flags = 0;
126 /* Flush all readers on this fs */
127 wake_up_all(&fc->waitq);
128 fuse_release_conn(fc);
129 SB_FC(sb) = NULL;
130 spin_unlock(&fuse_lock);
131 }
132
133 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
134 {
135 stbuf->f_type = FUSE_SUPER_MAGIC;
136 stbuf->f_bsize = attr->bsize;
137 stbuf->f_blocks = attr->blocks;
138 stbuf->f_bfree = attr->bfree;
139 stbuf->f_bavail = attr->bavail;
140 stbuf->f_files = attr->files;
141 stbuf->f_ffree = attr->ffree;
142 stbuf->f_namelen = attr->namelen;
143 /* fsid is left zero */
144 }
145
146 static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
147 {
148 struct fuse_conn *fc = SB_FC(sb);
149 struct fuse_req *req;
150 struct fuse_statfs_out outarg;
151 int err;
152
153 req = fuse_get_request(fc);
154 if (!req)
155 return -ERESTARTSYS;
156
157 req->in.numargs = 0;
158 req->in.h.opcode = FUSE_STATFS;
159 req->out.numargs = 1;
160 req->out.args[0].size = sizeof(outarg);
161 req->out.args[0].value = &outarg;
162 request_send(fc, req);
163 err = req->out.h.error;
164 if (!err)
165 convert_fuse_statfs(buf, &outarg.st);
166 fuse_put_request(fc, req);
167 return err;
168 }
169
170 enum { opt_fd,
171 opt_rootmode,
172 opt_uid,
173 opt_default_permissions,
174 opt_allow_other,
175 opt_kernel_cache,
176 #ifndef KERNEL_2_6
177 opt_large_read,
178 #endif
179 opt_direct_io,
180 opt_max_read,
181 opt_err };
182
183 static match_table_t tokens = {
184 {opt_fd, "fd=%u"},
185 {opt_rootmode, "rootmode=%o"},
186 {opt_uid, "uid=%u"},
187 {opt_default_permissions, "default_permissions"},
188 {opt_allow_other, "allow_other"},
189 {opt_kernel_cache, "kernel_cache"},
190 #ifndef KERNEL_2_6
191 {opt_large_read, "large_read"},
192 #endif
193 {opt_direct_io, "direct_io"},
194 {opt_max_read, "max_read=%u" },
195 {opt_err, NULL}
196 };
197
198 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
199 {
200 char *p;
201 memset(d, 0, sizeof(struct fuse_mount_data));
202 d->fd = -1;
203 d->max_read = ~0;
204
205 while ((p = strsep(&opt, ",")) != NULL) {
206 int token;
207 int value;
208 substring_t args[MAX_OPT_ARGS];
209 if (!*p)
210 continue;
211
212 token = match_token(p, tokens, args);
213 switch (token) {
214 case opt_fd:
215 if (match_int(&args[0], &value))
216 return 0;
217 d->fd = value;
218 break;
219
220 case opt_rootmode:
221 if (match_octal(&args[0], &value))
222 return 0;
223 d->rootmode = value;
224 break;
225
226 case opt_uid:
227 if (match_int(&args[0], &value))
228 return 0;
229 d->uid = value;
230 break;
231
232 case opt_default_permissions:
233 d->flags |= FUSE_DEFAULT_PERMISSIONS;
234 break;
235
236 case opt_allow_other:
237 d->flags |= FUSE_ALLOW_OTHER;
238 break;
239
240 case opt_kernel_cache:
241 d->flags |= FUSE_KERNEL_CACHE;
242 break;
243
244 #ifndef KERNEL_2_6
245 case opt_large_read:
246 d->flags |= FUSE_LARGE_READ;
247 break;
248 #endif
249
250 case opt_direct_io:
251 d->flags |= FUSE_DIRECT_IO;
252 break;
253
254 case opt_max_read:
255 if (match_int(&args[0], &value))
256 return 0;
257 d->max_read = value;
258 break;
259
260 default:
261 return 0;
262 }
263 }
264 if (d->fd == -1)
265 return 0;
266
267 return 1;
268 }
269
270 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
271 {
272 struct fuse_conn *fc = SB_FC(mnt->mnt_sb);
273
274 seq_printf(m, ",uid=%u", fc->uid);
275 if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
276 seq_puts(m, ",default_permissions");
277 if (fc->flags & FUSE_ALLOW_OTHER)
278 seq_puts(m, ",allow_other");
279 if (fc->flags & FUSE_KERNEL_CACHE)
280 seq_puts(m, ",kernel_cache");
281 #ifndef KERNEL_2_6
282 if (fc->flags & FUSE_LARGE_READ)
283 seq_puts(m, ",large_read");
284 #endif
285 if (fc->flags & FUSE_DIRECT_IO)
286 seq_puts(m, ",direct_io");
287 if (fc->max_read != ~0)
288 seq_printf(m, ",max_read=%u", fc->max_read);
289 return 0;
290 }
291
292 static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
293 {
294 struct fuse_conn *fc;
295 struct inode *ino;
296
297 ino = file->f_dentry->d_inode;
298 if (!ino || !proc_fuse_dev || proc_fuse_dev->low_ino != ino->i_ino) {
299 printk("FUSE: bad communication file descriptor\n");
300 return NULL;
301 }
302 fc = file->private_data;
303 if (fc->sb != NULL) {
304 printk("fuse_read_super: connection already mounted\n");
305 return NULL;
306 }
307 fc->sb = sb;
308 return fc;
309 }
310
311 static struct inode *get_root_inode(struct super_block *sb, unsigned int mode)
312 {
313 struct fuse_attr attr;
314 memset(&attr, 0, sizeof(attr));
315
316 attr.mode = mode;
317 return fuse_iget(sb, 1, 0, &attr, 0);
318 }
319
320
321 #ifdef KERNEL_2_6
322
323 static struct dentry *fuse_get_dentry(struct super_block *sb, void *vobjp)
324 {
325 __u32 *objp = vobjp;
326 unsigned long ino = objp[0];
327 __u32 generation = objp[1];
328 struct inode *inode;
329 struct dentry *entry;
330
331 if (ino == 0)
332 return ERR_PTR(-ESTALE);
333
334 inode = ilookup(sb, ino);
335 if (!inode || inode->i_generation != generation)
336 return ERR_PTR(-ESTALE);
337
338 entry = d_alloc_anon(inode);
339 if (!entry) {
340 iput(inode);
341 return ERR_PTR(-ENOMEM);
342 }
343
344 return entry;
345 }
346
347 static struct export_operations fuse_export_operations = {
348 .get_dentry = fuse_get_dentry,
349 };
350 #endif
351
352 static struct super_operations fuse_super_operations = {
353 .read_inode = fuse_read_inode,
354 .clear_inode = fuse_clear_inode,
355 .put_super = fuse_put_super,
356 .statfs = fuse_statfs,
357 .show_options = fuse_show_options,
358 };
359
360 static int fuse_read_super(struct super_block *sb, void *data, int silent)
361 {
362 struct fuse_conn *fc;
363 struct inode *root;
364 struct fuse_mount_data d;
365 struct file *file;
366
367 if (!parse_fuse_opt((char *) data, &d))
368 return -EINVAL;
369
370 if (!user_allow_other && (d.flags & FUSE_ALLOW_OTHER) &&
371 current->uid != 0)
372 return -EPERM;
373
374 sb->s_blocksize = PAGE_CACHE_SIZE;
375 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
376 sb->s_magic = FUSE_SUPER_MAGIC;
377 sb->s_op = &fuse_super_operations;
378 sb->s_maxbytes = MAX_LFS_FILESIZE;
379 #ifdef KERNEL_2_6
380 sb->s_export_op = &fuse_export_operations;
381 #endif
382
383 file = fget(d.fd);
384 if (!file)
385 return -EINVAL;
386
387 spin_lock(&fuse_lock);
388 fc = get_conn(file, sb);
389 spin_unlock(&fuse_lock);
390 fput(file);
391 if (fc == NULL)
392 return -EINVAL;
393
394 fc->flags = d.flags;
395 fc->uid = d.uid;
396 fc->max_read = d.max_read;
397 fc->max_write = FUSE_MAX_IN / 2;
398
399 /* fc is needed in fuse_init_file_inode which could be called
400 from get_root_inode */
401 SB_FC(sb) = fc;
402
403 root = get_root_inode(sb, d.rootmode);
404 if (root == NULL) {
405 printk("fuse_read_super: failed to get root inode\n");
406 goto err;
407 }
408
409 sb->s_root = d_alloc_root(root);
410 if (!sb->s_root) {
411 iput(root);
412 goto err;
413 }
414
415 return 0;
416
417 err:
418 spin_lock(&fuse_lock);
419 fc->sb = NULL;
420 fuse_release_conn(fc);
421 spin_unlock(&fuse_lock);
422 SB_FC(sb) = NULL;
423 return -EINVAL;
424 }
425
426 #ifdef KERNEL_2_6
427 static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
428 int flags, const char *dev_name,
429 void *raw_data)
430 {
431 return get_sb_nodev(fs_type, flags, raw_data, fuse_read_super);
432 }
433
434 static struct file_system_type fuse_fs_type = {
435 .owner = THIS_MODULE,
436 .name = "fuse",
437 .get_sb = fuse_get_sb,
438 .kill_sb = kill_anon_super,
439 .fs_flags = FS_SAFE,
440 };
441 #else
442 static struct super_block *fuse_read_super_compat(struct super_block *sb,
443 void *data, int silent)
444 {
445 int err = fuse_read_super(sb, data, silent);
446 if (err)
447 return NULL;
448 else
449 return sb;
450 }
451
452 static DECLARE_FSTYPE(fuse_fs_type, "fuse", fuse_read_super_compat, 0);
453 #endif
454
455 int fuse_fs_init()
456 {
457 int err;
458
459 err = register_filesystem(&fuse_fs_type);
460 if (err)
461 printk("fuse: failed to register filesystem\n");
462 else {
463 fuse_inode_cachep = kmem_cache_create("fuse_inode",
464 sizeof(struct fuse_inode),
465 0, 0, NULL, NULL);
466 if (!fuse_inode_cachep) {
467 unregister_filesystem(&fuse_fs_type);
468 err = -ENOMEM;
469 }
470 }
471
472 return err;
473 }
474
475 void fuse_fs_cleanup()
476 {
477 unregister_filesystem(&fuse_fs_type);
478 kmem_cache_destroy(fuse_inode_cachep);
479 }
480
481 /*
482 * Local Variables:
483 * indent-tabs-mode: t
484 * c-basic-offset: 8
485 * End:
486 */

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