Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) | |
3 | * Licensed under the GPL | |
4 | * | |
5 | * Ported the filesystem routines to 2.5. | |
6 | * 2003-02-10 Petr Baudis <pasky@ucw.cz> | |
7 | */ | |
8 | ||
9 | #include <linux/stddef.h> | |
10 | #include <linux/fs.h> | |
1da177e4 LT |
11 | #include <linux/module.h> |
12 | #include <linux/init.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/pagemap.h> | |
15 | #include <linux/blkdev.h> | |
16 | #include <linux/list.h> | |
1da177e4 LT |
17 | #include <linux/statfs.h> |
18 | #include <linux/kdev_t.h> | |
19 | #include <asm/uaccess.h> | |
20 | #include "hostfs.h" | |
21 | #include "kern_util.h" | |
22 | #include "kern.h" | |
23 | #include "user_util.h" | |
1da177e4 LT |
24 | #include "init.h" |
25 | ||
26 | struct hostfs_inode_info { | |
27 | char *host_filename; | |
28 | int fd; | |
29 | int mode; | |
30 | struct inode vfs_inode; | |
31 | }; | |
32 | ||
33 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
34 | { | |
35 | return(list_entry(inode, struct hostfs_inode_info, vfs_inode)); | |
36 | } | |
37 | ||
680b0da9 | 38 | #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) |
1da177e4 LT |
39 | |
40 | int hostfs_d_delete(struct dentry *dentry) | |
41 | { | |
42 | return(1); | |
43 | } | |
44 | ||
45 | struct dentry_operations hostfs_dentry_ops = { | |
46 | .d_delete = hostfs_d_delete, | |
47 | }; | |
48 | ||
49 | /* Changed in hostfs_args before the kernel starts running */ | |
50 | static char *root_ino = "/"; | |
51 | static int append = 0; | |
52 | ||
53 | #define HOSTFS_SUPER_MAGIC 0x00c0ffee | |
54 | ||
92e1d5be AV |
55 | static const struct inode_operations hostfs_iops; |
56 | static const struct inode_operations hostfs_dir_iops; | |
f5e54d6e | 57 | static const struct address_space_operations hostfs_link_aops; |
1da177e4 LT |
58 | |
59 | #ifndef MODULE | |
60 | static int __init hostfs_args(char *options, int *add) | |
61 | { | |
62 | char *ptr; | |
63 | ||
64 | ptr = strchr(options, ','); | |
65 | if(ptr != NULL) | |
66 | *ptr++ = '\0'; | |
67 | if(*options != '\0') | |
68 | root_ino = options; | |
69 | ||
70 | options = ptr; | |
71 | while(options){ | |
72 | ptr = strchr(options, ','); | |
73 | if(ptr != NULL) | |
74 | *ptr++ = '\0'; | |
75 | if(*options != '\0'){ | |
76 | if(!strcmp(options, "append")) | |
77 | append = 1; | |
78 | else printf("hostfs_args - unsupported option - %s\n", | |
79 | options); | |
80 | } | |
81 | options = ptr; | |
82 | } | |
83 | return(0); | |
84 | } | |
85 | ||
86 | __uml_setup("hostfs=", hostfs_args, | |
87 | "hostfs=<root dir>,<flags>,...\n" | |
88 | " This is used to set hostfs parameters. The root directory argument\n" | |
89 | " is used to confine all hostfs mounts to within the specified directory\n" | |
90 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
91 | " mount anything on the host that's accessible to the user that's running\n" | |
92 | " it.\n" | |
93 | " The only flag currently supported is 'append', which specifies that all\n" | |
94 | " files opened by hostfs will be opened in append mode.\n\n" | |
95 | ); | |
96 | #endif | |
97 | ||
98 | static char *dentry_name(struct dentry *dentry, int extra) | |
99 | { | |
100 | struct dentry *parent; | |
101 | char *root, *name; | |
102 | int len; | |
103 | ||
104 | len = 0; | |
105 | parent = dentry; | |
106 | while(parent->d_parent != parent){ | |
107 | len += parent->d_name.len + 1; | |
108 | parent = parent->d_parent; | |
109 | } | |
110 | ||
111 | root = HOSTFS_I(parent->d_inode)->host_filename; | |
112 | len += strlen(root); | |
113 | name = kmalloc(len + extra + 1, GFP_KERNEL); | |
114 | if(name == NULL) return(NULL); | |
115 | ||
116 | name[len] = '\0'; | |
117 | parent = dentry; | |
118 | while(parent->d_parent != parent){ | |
119 | len -= parent->d_name.len + 1; | |
120 | name[len] = '/'; | |
121 | strncpy(&name[len + 1], parent->d_name.name, | |
122 | parent->d_name.len); | |
123 | parent = parent->d_parent; | |
124 | } | |
125 | strncpy(name, root, strlen(root)); | |
126 | return(name); | |
127 | } | |
128 | ||
129 | static char *inode_name(struct inode *ino, int extra) | |
130 | { | |
131 | struct dentry *dentry; | |
132 | ||
133 | dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); | |
134 | return(dentry_name(dentry, extra)); | |
135 | } | |
136 | ||
137 | static int read_name(struct inode *ino, char *name) | |
138 | { | |
139 | /* The non-int inode fields are copied into ints by stat_file and | |
140 | * then copied into the inode because passing the actual pointers | |
141 | * in and having them treated as int * breaks on big-endian machines | |
142 | */ | |
143 | int err; | |
144 | int i_mode, i_nlink, i_blksize; | |
145 | unsigned long long i_size; | |
146 | unsigned long long i_ino; | |
147 | unsigned long long i_blocks; | |
148 | ||
149 | err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid, | |
150 | &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime, | |
151 | &ino->i_ctime, &i_blksize, &i_blocks); | |
152 | if(err) | |
153 | return(err); | |
154 | ||
155 | ino->i_ino = i_ino; | |
156 | ino->i_mode = i_mode; | |
157 | ino->i_nlink = i_nlink; | |
158 | ino->i_size = i_size; | |
1da177e4 | 159 | ino->i_blocks = i_blocks; |
1da177e4 LT |
160 | return(0); |
161 | } | |
162 | ||
163 | static char *follow_link(char *link) | |
164 | { | |
165 | int len, n; | |
166 | char *name, *resolved, *end; | |
167 | ||
168 | len = 64; | |
169 | while(1){ | |
170 | n = -ENOMEM; | |
171 | name = kmalloc(len, GFP_KERNEL); | |
172 | if(name == NULL) | |
173 | goto out; | |
174 | ||
175 | n = do_readlink(link, name, len); | |
176 | if(n < len) | |
177 | break; | |
178 | len *= 2; | |
179 | kfree(name); | |
180 | } | |
181 | if(n < 0) | |
182 | goto out_free; | |
183 | ||
184 | if(*name == '/') | |
185 | return(name); | |
186 | ||
187 | end = strrchr(link, '/'); | |
188 | if(end == NULL) | |
189 | return(name); | |
190 | ||
191 | *(end + 1) = '\0'; | |
192 | len = strlen(link) + strlen(name) + 1; | |
193 | ||
194 | resolved = kmalloc(len, GFP_KERNEL); | |
195 | if(resolved == NULL){ | |
196 | n = -ENOMEM; | |
197 | goto out_free; | |
198 | } | |
199 | ||
200 | sprintf(resolved, "%s%s", link, name); | |
201 | kfree(name); | |
202 | kfree(link); | |
203 | return(resolved); | |
204 | ||
205 | out_free: | |
206 | kfree(name); | |
207 | out: | |
208 | return(ERR_PTR(n)); | |
209 | } | |
210 | ||
211 | static int read_inode(struct inode *ino) | |
212 | { | |
213 | char *name; | |
214 | int err = 0; | |
215 | ||
216 | /* Unfortunately, we are called from iget() when we don't have a dentry | |
217 | * allocated yet. | |
218 | */ | |
219 | if(list_empty(&ino->i_dentry)) | |
220 | goto out; | |
221 | ||
222 | err = -ENOMEM; | |
223 | name = inode_name(ino, 0); | |
224 | if(name == NULL) | |
225 | goto out; | |
226 | ||
227 | if(file_type(name, NULL, NULL) == OS_TYPE_SYMLINK){ | |
228 | name = follow_link(name); | |
229 | if(IS_ERR(name)){ | |
230 | err = PTR_ERR(name); | |
231 | goto out; | |
232 | } | |
233 | } | |
234 | ||
235 | err = read_name(ino, name); | |
236 | kfree(name); | |
237 | out: | |
238 | return(err); | |
239 | } | |
240 | ||
726c3342 | 241 | int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 LT |
242 | { |
243 | /* do_statfs uses struct statfs64 internally, but the linux kernel | |
244 | * struct statfs still has 32-bit versions for most of these fields, | |
245 | * so we convert them here | |
246 | */ | |
247 | int err; | |
248 | long long f_blocks; | |
249 | long long f_bfree; | |
250 | long long f_bavail; | |
251 | long long f_files; | |
252 | long long f_ffree; | |
253 | ||
726c3342 | 254 | err = do_statfs(HOSTFS_I(dentry->d_sb->s_root->d_inode)->host_filename, |
1da177e4 LT |
255 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
256 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
257 | &sf->f_namelen, sf->f_spare); | |
258 | if(err) return(err); | |
259 | sf->f_blocks = f_blocks; | |
260 | sf->f_bfree = f_bfree; | |
261 | sf->f_bavail = f_bavail; | |
262 | sf->f_files = f_files; | |
263 | sf->f_ffree = f_ffree; | |
264 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
265 | return(0); | |
266 | } | |
267 | ||
268 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
269 | { | |
270 | struct hostfs_inode_info *hi; | |
271 | ||
272 | hi = kmalloc(sizeof(*hi), GFP_KERNEL); | |
273 | if(hi == NULL) | |
274 | return(NULL); | |
275 | ||
276 | *hi = ((struct hostfs_inode_info) { .host_filename = NULL, | |
277 | .fd = -1, | |
278 | .mode = 0 }); | |
279 | inode_init_once(&hi->vfs_inode); | |
280 | return(&hi->vfs_inode); | |
281 | } | |
282 | ||
283 | static void hostfs_delete_inode(struct inode *inode) | |
284 | { | |
fef26658 | 285 | truncate_inode_pages(&inode->i_data, 0); |
1da177e4 LT |
286 | if(HOSTFS_I(inode)->fd != -1) { |
287 | close_file(&HOSTFS_I(inode)->fd); | |
288 | HOSTFS_I(inode)->fd = -1; | |
289 | } | |
290 | clear_inode(inode); | |
291 | } | |
292 | ||
293 | static void hostfs_destroy_inode(struct inode *inode) | |
294 | { | |
f99d49ad | 295 | kfree(HOSTFS_I(inode)->host_filename); |
1da177e4 LT |
296 | |
297 | /*XXX: This should not happen, probably. The check is here for | |
298 | * additional safety.*/ | |
299 | if(HOSTFS_I(inode)->fd != -1) { | |
300 | close_file(&HOSTFS_I(inode)->fd); | |
301 | printk(KERN_DEBUG "Closing host fd in .destroy_inode\n"); | |
302 | } | |
303 | ||
304 | kfree(HOSTFS_I(inode)); | |
305 | } | |
306 | ||
307 | static void hostfs_read_inode(struct inode *inode) | |
308 | { | |
309 | read_inode(inode); | |
310 | } | |
311 | ||
ee9b6d61 | 312 | static const struct super_operations hostfs_sbops = { |
1da177e4 LT |
313 | .alloc_inode = hostfs_alloc_inode, |
314 | .drop_inode = generic_delete_inode, | |
315 | .delete_inode = hostfs_delete_inode, | |
316 | .destroy_inode = hostfs_destroy_inode, | |
317 | .read_inode = hostfs_read_inode, | |
318 | .statfs = hostfs_statfs, | |
319 | }; | |
320 | ||
321 | int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) | |
322 | { | |
323 | void *dir; | |
324 | char *name; | |
325 | unsigned long long next, ino; | |
326 | int error, len; | |
327 | ||
680b0da9 | 328 | name = dentry_name(file->f_path.dentry, 0); |
1da177e4 LT |
329 | if(name == NULL) return(-ENOMEM); |
330 | dir = open_dir(name, &error); | |
331 | kfree(name); | |
332 | if(dir == NULL) return(-error); | |
333 | next = file->f_pos; | |
334 | while((name = read_dir(dir, &next, &ino, &len)) != NULL){ | |
335 | error = (*filldir)(ent, name, len, file->f_pos, | |
336 | ino, DT_UNKNOWN); | |
337 | if(error) break; | |
338 | file->f_pos = next; | |
339 | } | |
340 | close_dir(dir); | |
341 | return(0); | |
342 | } | |
343 | ||
344 | int hostfs_file_open(struct inode *ino, struct file *file) | |
345 | { | |
346 | char *name; | |
347 | int mode = 0, r = 0, w = 0, fd; | |
348 | ||
349 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
350 | if((mode & HOSTFS_I(ino)->mode) == mode) | |
351 | return(0); | |
352 | ||
353 | /* The file may already have been opened, but with the wrong access, | |
354 | * so this resets things and reopens the file with the new access. | |
355 | */ | |
356 | if(HOSTFS_I(ino)->fd != -1){ | |
357 | close_file(&HOSTFS_I(ino)->fd); | |
358 | HOSTFS_I(ino)->fd = -1; | |
359 | } | |
360 | ||
361 | HOSTFS_I(ino)->mode |= mode; | |
362 | if(HOSTFS_I(ino)->mode & FMODE_READ) | |
363 | r = 1; | |
364 | if(HOSTFS_I(ino)->mode & FMODE_WRITE) | |
365 | w = 1; | |
366 | if(w) | |
367 | r = 1; | |
368 | ||
680b0da9 | 369 | name = dentry_name(file->f_path.dentry, 0); |
1da177e4 LT |
370 | if(name == NULL) |
371 | return(-ENOMEM); | |
372 | ||
373 | fd = open_file(name, r, w, append); | |
374 | kfree(name); | |
375 | if(fd < 0) return(fd); | |
376 | FILE_HOSTFS_I(file)->fd = fd; | |
377 | ||
378 | return(0); | |
379 | } | |
380 | ||
381 | int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync) | |
382 | { | |
a2d76bd8 | 383 | return fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync); |
1da177e4 LT |
384 | } |
385 | ||
4b6f5d20 | 386 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 387 | .llseek = generic_file_llseek, |
543ade1f | 388 | .read = do_sync_read, |
1da177e4 LT |
389 | .sendfile = generic_file_sendfile, |
390 | .aio_read = generic_file_aio_read, | |
391 | .aio_write = generic_file_aio_write, | |
543ade1f | 392 | .write = do_sync_write, |
1da177e4 LT |
393 | .mmap = generic_file_mmap, |
394 | .open = hostfs_file_open, | |
395 | .release = NULL, | |
396 | .fsync = hostfs_fsync, | |
397 | }; | |
398 | ||
4b6f5d20 | 399 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
400 | .llseek = generic_file_llseek, |
401 | .readdir = hostfs_readdir, | |
402 | .read = generic_read_dir, | |
403 | }; | |
404 | ||
405 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
406 | { | |
407 | struct address_space *mapping = page->mapping; | |
408 | struct inode *inode = mapping->host; | |
409 | char *buffer; | |
410 | unsigned long long base; | |
411 | int count = PAGE_CACHE_SIZE; | |
412 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
413 | int err; | |
414 | ||
415 | if (page->index >= end_index) | |
416 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
417 | ||
418 | buffer = kmap(page); | |
419 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
420 | ||
421 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
422 | if(err != count){ | |
423 | ClearPageUptodate(page); | |
424 | goto out; | |
425 | } | |
426 | ||
427 | if (base > inode->i_size) | |
428 | inode->i_size = base; | |
429 | ||
430 | if (PageError(page)) | |
431 | ClearPageError(page); | |
432 | err = 0; | |
433 | ||
434 | out: | |
435 | kunmap(page); | |
436 | ||
437 | unlock_page(page); | |
438 | return err; | |
439 | } | |
440 | ||
441 | int hostfs_readpage(struct file *file, struct page *page) | |
442 | { | |
443 | char *buffer; | |
444 | long long start; | |
445 | int err = 0; | |
446 | ||
447 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
448 | buffer = kmap(page); | |
449 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
450 | PAGE_CACHE_SIZE); | |
451 | if(err < 0) goto out; | |
452 | ||
453 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
454 | ||
455 | flush_dcache_page(page); | |
456 | SetPageUptodate(page); | |
457 | if (PageError(page)) ClearPageError(page); | |
458 | err = 0; | |
459 | out: | |
460 | kunmap(page); | |
461 | unlock_page(page); | |
462 | return(err); | |
463 | } | |
464 | ||
465 | int hostfs_prepare_write(struct file *file, struct page *page, | |
466 | unsigned int from, unsigned int to) | |
467 | { | |
468 | char *buffer; | |
469 | long long start, tmp; | |
470 | int err; | |
471 | ||
472 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
473 | buffer = kmap(page); | |
474 | if(from != 0){ | |
475 | tmp = start; | |
476 | err = read_file(FILE_HOSTFS_I(file)->fd, &tmp, buffer, | |
477 | from); | |
478 | if(err < 0) goto out; | |
479 | } | |
480 | if(to != PAGE_CACHE_SIZE){ | |
481 | start += to; | |
482 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer + to, | |
483 | PAGE_CACHE_SIZE - to); | |
484 | if(err < 0) goto out; | |
485 | } | |
486 | err = 0; | |
487 | out: | |
488 | kunmap(page); | |
489 | return(err); | |
490 | } | |
491 | ||
492 | int hostfs_commit_write(struct file *file, struct page *page, unsigned from, | |
493 | unsigned to) | |
494 | { | |
495 | struct address_space *mapping = page->mapping; | |
496 | struct inode *inode = mapping->host; | |
497 | char *buffer; | |
498 | long long start; | |
499 | int err = 0; | |
500 | ||
30f04a4e | 501 | start = (((long long) page->index) << PAGE_CACHE_SHIFT) + from; |
1da177e4 LT |
502 | buffer = kmap(page); |
503 | err = write_file(FILE_HOSTFS_I(file)->fd, &start, buffer + from, | |
504 | to - from); | |
505 | if(err > 0) err = 0; | |
30f04a4e PBG |
506 | |
507 | /* Actually, if !err, write_file has added to-from to start, so, despite | |
508 | * the appearance, we are comparing i_size against the _last_ written | |
509 | * location, as we should. */ | |
510 | ||
1da177e4 LT |
511 | if(!err && (start > inode->i_size)) |
512 | inode->i_size = start; | |
513 | ||
514 | kunmap(page); | |
515 | return(err); | |
516 | } | |
517 | ||
f5e54d6e | 518 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
519 | .writepage = hostfs_writepage, |
520 | .readpage = hostfs_readpage, | |
ffa0aea6 | 521 | .set_page_dirty = __set_page_dirty_nobuffers, |
1da177e4 LT |
522 | .prepare_write = hostfs_prepare_write, |
523 | .commit_write = hostfs_commit_write | |
524 | }; | |
525 | ||
526 | static int init_inode(struct inode *inode, struct dentry *dentry) | |
527 | { | |
528 | char *name; | |
529 | int type, err = -ENOMEM; | |
530 | int maj, min; | |
531 | dev_t rdev = 0; | |
532 | ||
533 | if(dentry){ | |
534 | name = dentry_name(dentry, 0); | |
535 | if(name == NULL) | |
536 | goto out; | |
537 | type = file_type(name, &maj, &min); | |
538 | /*Reencode maj and min with the kernel encoding.*/ | |
539 | rdev = MKDEV(maj, min); | |
540 | kfree(name); | |
541 | } | |
542 | else type = OS_TYPE_DIR; | |
543 | ||
544 | err = 0; | |
545 | if(type == OS_TYPE_SYMLINK) | |
546 | inode->i_op = &page_symlink_inode_operations; | |
547 | else if(type == OS_TYPE_DIR) | |
548 | inode->i_op = &hostfs_dir_iops; | |
549 | else inode->i_op = &hostfs_iops; | |
550 | ||
551 | if(type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; | |
552 | else inode->i_fop = &hostfs_file_fops; | |
553 | ||
554 | if(type == OS_TYPE_SYMLINK) | |
555 | inode->i_mapping->a_ops = &hostfs_link_aops; | |
556 | else inode->i_mapping->a_ops = &hostfs_aops; | |
557 | ||
558 | switch (type) { | |
559 | case OS_TYPE_CHARDEV: | |
560 | init_special_inode(inode, S_IFCHR, rdev); | |
561 | break; | |
562 | case OS_TYPE_BLOCKDEV: | |
563 | init_special_inode(inode, S_IFBLK, rdev); | |
564 | break; | |
565 | case OS_TYPE_FIFO: | |
566 | init_special_inode(inode, S_IFIFO, 0); | |
567 | break; | |
568 | case OS_TYPE_SOCK: | |
569 | init_special_inode(inode, S_IFSOCK, 0); | |
570 | break; | |
571 | } | |
572 | out: | |
573 | return(err); | |
574 | } | |
575 | ||
576 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
577 | struct nameidata *nd) | |
578 | { | |
579 | struct inode *inode; | |
580 | char *name; | |
581 | int error, fd; | |
582 | ||
583 | error = -ENOMEM; | |
584 | inode = iget(dir->i_sb, 0); | |
585 | if(inode == NULL) goto out; | |
586 | ||
587 | error = init_inode(inode, dentry); | |
588 | if(error) | |
589 | goto out_put; | |
590 | ||
591 | error = -ENOMEM; | |
592 | name = dentry_name(dentry, 0); | |
593 | if(name == NULL) | |
594 | goto out_put; | |
595 | ||
596 | fd = file_create(name, | |
597 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
598 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
599 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
600 | if(fd < 0) | |
601 | error = fd; | |
602 | else error = read_name(inode, name); | |
603 | ||
604 | kfree(name); | |
605 | if(error) | |
606 | goto out_put; | |
607 | ||
608 | HOSTFS_I(inode)->fd = fd; | |
609 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
610 | d_instantiate(dentry, inode); | |
611 | return(0); | |
612 | ||
613 | out_put: | |
614 | iput(inode); | |
615 | out: | |
616 | return(error); | |
617 | } | |
618 | ||
619 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
620 | struct nameidata *nd) | |
621 | { | |
622 | struct inode *inode; | |
623 | char *name; | |
624 | int err; | |
625 | ||
626 | err = -ENOMEM; | |
627 | inode = iget(ino->i_sb, 0); | |
628 | if(inode == NULL) | |
629 | goto out; | |
630 | ||
631 | err = init_inode(inode, dentry); | |
632 | if(err) | |
633 | goto out_put; | |
634 | ||
635 | err = -ENOMEM; | |
636 | name = dentry_name(dentry, 0); | |
637 | if(name == NULL) | |
638 | goto out_put; | |
639 | ||
640 | err = read_name(inode, name); | |
641 | kfree(name); | |
642 | if(err == -ENOENT){ | |
643 | iput(inode); | |
644 | inode = NULL; | |
645 | } | |
646 | else if(err) | |
647 | goto out_put; | |
648 | ||
649 | d_add(dentry, inode); | |
650 | dentry->d_op = &hostfs_dentry_ops; | |
651 | return(NULL); | |
652 | ||
653 | out_put: | |
654 | iput(inode); | |
655 | out: | |
656 | return(ERR_PTR(err)); | |
657 | } | |
658 | ||
659 | static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) | |
660 | { | |
661 | char *file; | |
662 | int len; | |
663 | ||
664 | file = inode_name(ino, dentry->d_name.len + 1); | |
665 | if(file == NULL) return(NULL); | |
666 | strcat(file, "/"); | |
667 | len = strlen(file); | |
668 | strncat(file, dentry->d_name.name, dentry->d_name.len); | |
669 | file[len + dentry->d_name.len] = '\0'; | |
670 | return(file); | |
671 | } | |
672 | ||
673 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) | |
674 | { | |
675 | char *from_name, *to_name; | |
676 | int err; | |
677 | ||
678 | if((from_name = inode_dentry_name(ino, from)) == NULL) | |
679 | return(-ENOMEM); | |
680 | to_name = dentry_name(to, 0); | |
681 | if(to_name == NULL){ | |
682 | kfree(from_name); | |
683 | return(-ENOMEM); | |
684 | } | |
685 | err = link_file(to_name, from_name); | |
686 | kfree(from_name); | |
687 | kfree(to_name); | |
688 | return(err); | |
689 | } | |
690 | ||
691 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
692 | { | |
693 | char *file; | |
694 | int err; | |
695 | ||
696 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
697 | if(append) | |
698 | return(-EPERM); | |
699 | ||
700 | err = unlink_file(file); | |
701 | kfree(file); | |
702 | return(err); | |
703 | } | |
704 | ||
705 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
706 | { | |
707 | char *file; | |
708 | int err; | |
709 | ||
710 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
711 | err = make_symlink(file, to); | |
712 | kfree(file); | |
713 | return(err); | |
714 | } | |
715 | ||
716 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
717 | { | |
718 | char *file; | |
719 | int err; | |
720 | ||
721 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
722 | err = do_mkdir(file, mode); | |
723 | kfree(file); | |
724 | return(err); | |
725 | } | |
726 | ||
727 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
728 | { | |
729 | char *file; | |
730 | int err; | |
731 | ||
732 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
733 | err = do_rmdir(file); | |
734 | kfree(file); | |
735 | return(err); | |
736 | } | |
737 | ||
738 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
739 | { | |
740 | struct inode *inode; | |
741 | char *name; | |
742 | int err = -ENOMEM; | |
743 | ||
744 | inode = iget(dir->i_sb, 0); | |
745 | if(inode == NULL) | |
746 | goto out; | |
747 | ||
748 | err = init_inode(inode, dentry); | |
749 | if(err) | |
750 | goto out_put; | |
751 | ||
752 | err = -ENOMEM; | |
753 | name = dentry_name(dentry, 0); | |
754 | if(name == NULL) | |
755 | goto out_put; | |
756 | ||
757 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 758 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
1da177e4 LT |
759 | if(err) |
760 | goto out_free; | |
761 | ||
762 | err = read_name(inode, name); | |
763 | kfree(name); | |
764 | if(err) | |
765 | goto out_put; | |
766 | ||
767 | d_instantiate(dentry, inode); | |
768 | return(0); | |
769 | ||
770 | out_free: | |
771 | kfree(name); | |
772 | out_put: | |
773 | iput(inode); | |
774 | out: | |
775 | return(err); | |
776 | } | |
777 | ||
778 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
779 | struct inode *to_ino, struct dentry *to) | |
780 | { | |
781 | char *from_name, *to_name; | |
782 | int err; | |
783 | ||
784 | if((from_name = inode_dentry_name(from_ino, from)) == NULL) | |
785 | return(-ENOMEM); | |
786 | if((to_name = inode_dentry_name(to_ino, to)) == NULL){ | |
787 | kfree(from_name); | |
788 | return(-ENOMEM); | |
789 | } | |
790 | err = rename_file(from_name, to_name); | |
791 | kfree(from_name); | |
792 | kfree(to_name); | |
793 | return(err); | |
794 | } | |
795 | ||
1da177e4 LT |
796 | int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) |
797 | { | |
798 | char *name; | |
799 | int r = 0, w = 0, x = 0, err; | |
800 | ||
801 | if (desired & MAY_READ) r = 1; | |
802 | if (desired & MAY_WRITE) w = 1; | |
803 | if (desired & MAY_EXEC) x = 1; | |
804 | name = inode_name(ino, 0); | |
805 | if (name == NULL) return(-ENOMEM); | |
806 | ||
807 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
808 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) | |
809 | err = 0; | |
810 | else | |
811 | err = access_file(name, r, w, x); | |
812 | kfree(name); | |
813 | if(!err) | |
814 | err = generic_permission(ino, desired, NULL); | |
815 | return err; | |
816 | } | |
817 | ||
818 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
819 | { | |
820 | struct hostfs_iattr attrs; | |
821 | char *name; | |
822 | int err; | |
823 | ||
824 | err = inode_change_ok(dentry->d_inode, attr); | |
825 | if (err) | |
826 | return err; | |
827 | ||
828 | if(append) | |
829 | attr->ia_valid &= ~ATTR_SIZE; | |
830 | ||
831 | attrs.ia_valid = 0; | |
832 | if(attr->ia_valid & ATTR_MODE){ | |
833 | attrs.ia_valid |= HOSTFS_ATTR_MODE; | |
834 | attrs.ia_mode = attr->ia_mode; | |
835 | } | |
836 | if(attr->ia_valid & ATTR_UID){ | |
1da177e4 LT |
837 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
838 | attrs.ia_uid = attr->ia_uid; | |
839 | } | |
840 | if(attr->ia_valid & ATTR_GID){ | |
1da177e4 LT |
841 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
842 | attrs.ia_gid = attr->ia_gid; | |
843 | } | |
844 | if(attr->ia_valid & ATTR_SIZE){ | |
845 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; | |
846 | attrs.ia_size = attr->ia_size; | |
847 | } | |
848 | if(attr->ia_valid & ATTR_ATIME){ | |
849 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; | |
850 | attrs.ia_atime = attr->ia_atime; | |
851 | } | |
852 | if(attr->ia_valid & ATTR_MTIME){ | |
853 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; | |
854 | attrs.ia_mtime = attr->ia_mtime; | |
855 | } | |
856 | if(attr->ia_valid & ATTR_CTIME){ | |
857 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; | |
858 | attrs.ia_ctime = attr->ia_ctime; | |
859 | } | |
860 | if(attr->ia_valid & ATTR_ATIME_SET){ | |
861 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; | |
862 | } | |
863 | if(attr->ia_valid & ATTR_MTIME_SET){ | |
864 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; | |
865 | } | |
866 | name = dentry_name(dentry, 0); | |
867 | if(name == NULL) return(-ENOMEM); | |
868 | err = set_attr(name, &attrs); | |
869 | kfree(name); | |
870 | if(err) | |
871 | return(err); | |
872 | ||
873 | return(inode_setattr(dentry->d_inode, attr)); | |
874 | } | |
875 | ||
876 | int hostfs_getattr(struct vfsmount *mnt, struct dentry *dentry, | |
877 | struct kstat *stat) | |
878 | { | |
879 | generic_fillattr(dentry->d_inode, stat); | |
880 | return(0); | |
881 | } | |
882 | ||
92e1d5be | 883 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
884 | .create = hostfs_create, |
885 | .link = hostfs_link, | |
886 | .unlink = hostfs_unlink, | |
887 | .symlink = hostfs_symlink, | |
888 | .mkdir = hostfs_mkdir, | |
889 | .rmdir = hostfs_rmdir, | |
890 | .mknod = hostfs_mknod, | |
891 | .rename = hostfs_rename, | |
1da177e4 LT |
892 | .permission = hostfs_permission, |
893 | .setattr = hostfs_setattr, | |
894 | .getattr = hostfs_getattr, | |
895 | }; | |
896 | ||
92e1d5be | 897 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
898 | .create = hostfs_create, |
899 | .lookup = hostfs_lookup, | |
900 | .link = hostfs_link, | |
901 | .unlink = hostfs_unlink, | |
902 | .symlink = hostfs_symlink, | |
903 | .mkdir = hostfs_mkdir, | |
904 | .rmdir = hostfs_rmdir, | |
905 | .mknod = hostfs_mknod, | |
906 | .rename = hostfs_rename, | |
1da177e4 LT |
907 | .permission = hostfs_permission, |
908 | .setattr = hostfs_setattr, | |
909 | .getattr = hostfs_getattr, | |
910 | }; | |
911 | ||
912 | int hostfs_link_readpage(struct file *file, struct page *page) | |
913 | { | |
914 | char *buffer, *name; | |
1da177e4 LT |
915 | int err; |
916 | ||
1da177e4 LT |
917 | buffer = kmap(page); |
918 | name = inode_name(page->mapping->host, 0); | |
919 | if(name == NULL) return(-ENOMEM); | |
920 | err = do_readlink(name, buffer, PAGE_CACHE_SIZE); | |
921 | kfree(name); | |
922 | if(err == PAGE_CACHE_SIZE) | |
923 | err = -E2BIG; | |
924 | else if(err > 0){ | |
925 | flush_dcache_page(page); | |
926 | SetPageUptodate(page); | |
927 | if (PageError(page)) ClearPageError(page); | |
928 | err = 0; | |
929 | } | |
930 | kunmap(page); | |
931 | unlock_page(page); | |
932 | return(err); | |
933 | } | |
934 | ||
f5e54d6e | 935 | static const struct address_space_operations hostfs_link_aops = { |
1da177e4 LT |
936 | .readpage = hostfs_link_readpage, |
937 | }; | |
938 | ||
939 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
940 | { | |
941 | struct inode *root_inode; | |
942 | char *name, *data = d; | |
943 | int err; | |
944 | ||
945 | sb->s_blocksize = 1024; | |
946 | sb->s_blocksize_bits = 10; | |
947 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
948 | sb->s_op = &hostfs_sbops; | |
949 | ||
950 | if((data == NULL) || (*data == '\0')) | |
951 | data = root_ino; | |
952 | ||
953 | err = -ENOMEM; | |
954 | name = kmalloc(strlen(data) + 1, GFP_KERNEL); | |
955 | if(name == NULL) | |
956 | goto out; | |
957 | ||
958 | strcpy(name, data); | |
959 | ||
960 | root_inode = iget(sb, 0); | |
961 | if(root_inode == NULL) | |
962 | goto out_free; | |
963 | ||
964 | err = init_inode(root_inode, NULL); | |
965 | if(err) | |
966 | goto out_put; | |
967 | ||
968 | HOSTFS_I(root_inode)->host_filename = name; | |
969 | ||
970 | err = -ENOMEM; | |
971 | sb->s_root = d_alloc_root(root_inode); | |
972 | if(sb->s_root == NULL) | |
973 | goto out_put; | |
974 | ||
975 | err = read_inode(root_inode); | |
51a14110 JD |
976 | if(err){ |
977 | /* No iput in this case because the dput does that for us */ | |
978 | dput(sb->s_root); | |
979 | sb->s_root = NULL; | |
980 | goto out_free; | |
981 | } | |
1da177e4 LT |
982 | |
983 | return(0); | |
984 | ||
985 | out_put: | |
51a14110 | 986 | iput(root_inode); |
1da177e4 LT |
987 | out_free: |
988 | kfree(name); | |
989 | out: | |
990 | return(err); | |
991 | } | |
992 | ||
454e2398 DH |
993 | static int hostfs_read_sb(struct file_system_type *type, |
994 | int flags, const char *dev_name, | |
995 | void *data, struct vfsmount *mnt) | |
1da177e4 | 996 | { |
454e2398 | 997 | return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); |
1da177e4 LT |
998 | } |
999 | ||
1000 | static struct file_system_type hostfs_type = { | |
1001 | .owner = THIS_MODULE, | |
1002 | .name = "hostfs", | |
1003 | .get_sb = hostfs_read_sb, | |
1004 | .kill_sb = kill_anon_super, | |
1005 | .fs_flags = 0, | |
1006 | }; | |
1007 | ||
1008 | static int __init init_hostfs(void) | |
1009 | { | |
1010 | return(register_filesystem(&hostfs_type)); | |
1011 | } | |
1012 | ||
1013 | static void __exit exit_hostfs(void) | |
1014 | { | |
1015 | unregister_filesystem(&hostfs_type); | |
1016 | } | |
1017 | ||
1018 | module_init(init_hostfs) | |
1019 | module_exit(exit_hostfs) | |
1020 | MODULE_LICENSE("GPL"); | |
1021 | ||
1022 | /* | |
1023 | * Overrides for Emacs so that we follow Linus's tabbing style. | |
1024 | * Emacs will notice this stuff at the end of the file and automatically | |
1025 | * adjust the settings for this buffer only. This must remain at the end | |
1026 | * of the file. | |
1027 | * --------------------------------------------------------------------------- | |
1028 | * Local variables: | |
1029 | * c-file-style: "linux" | |
1030 | * End: | |
1031 | */ |