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Commit | Line | Data |
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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 | ||
38 | #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_dentry->d_inode) | |
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 | ||
55 | static struct inode_operations hostfs_iops; | |
56 | static struct inode_operations hostfs_dir_iops; | |
57 | static struct address_space_operations hostfs_link_aops; | |
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; | |
159 | ino->i_blksize = i_blksize; | |
160 | ino->i_blocks = i_blocks; | |
1da177e4 LT |
161 | return(0); |
162 | } | |
163 | ||
164 | static char *follow_link(char *link) | |
165 | { | |
166 | int len, n; | |
167 | char *name, *resolved, *end; | |
168 | ||
169 | len = 64; | |
170 | while(1){ | |
171 | n = -ENOMEM; | |
172 | name = kmalloc(len, GFP_KERNEL); | |
173 | if(name == NULL) | |
174 | goto out; | |
175 | ||
176 | n = do_readlink(link, name, len); | |
177 | if(n < len) | |
178 | break; | |
179 | len *= 2; | |
180 | kfree(name); | |
181 | } | |
182 | if(n < 0) | |
183 | goto out_free; | |
184 | ||
185 | if(*name == '/') | |
186 | return(name); | |
187 | ||
188 | end = strrchr(link, '/'); | |
189 | if(end == NULL) | |
190 | return(name); | |
191 | ||
192 | *(end + 1) = '\0'; | |
193 | len = strlen(link) + strlen(name) + 1; | |
194 | ||
195 | resolved = kmalloc(len, GFP_KERNEL); | |
196 | if(resolved == NULL){ | |
197 | n = -ENOMEM; | |
198 | goto out_free; | |
199 | } | |
200 | ||
201 | sprintf(resolved, "%s%s", link, name); | |
202 | kfree(name); | |
203 | kfree(link); | |
204 | return(resolved); | |
205 | ||
206 | out_free: | |
207 | kfree(name); | |
208 | out: | |
209 | return(ERR_PTR(n)); | |
210 | } | |
211 | ||
212 | static int read_inode(struct inode *ino) | |
213 | { | |
214 | char *name; | |
215 | int err = 0; | |
216 | ||
217 | /* Unfortunately, we are called from iget() when we don't have a dentry | |
218 | * allocated yet. | |
219 | */ | |
220 | if(list_empty(&ino->i_dentry)) | |
221 | goto out; | |
222 | ||
223 | err = -ENOMEM; | |
224 | name = inode_name(ino, 0); | |
225 | if(name == NULL) | |
226 | goto out; | |
227 | ||
228 | if(file_type(name, NULL, NULL) == OS_TYPE_SYMLINK){ | |
229 | name = follow_link(name); | |
230 | if(IS_ERR(name)){ | |
231 | err = PTR_ERR(name); | |
232 | goto out; | |
233 | } | |
234 | } | |
235 | ||
236 | err = read_name(ino, name); | |
237 | kfree(name); | |
238 | out: | |
239 | return(err); | |
240 | } | |
241 | ||
242 | int hostfs_statfs(struct super_block *sb, struct kstatfs *sf) | |
243 | { | |
244 | /* do_statfs uses struct statfs64 internally, but the linux kernel | |
245 | * struct statfs still has 32-bit versions for most of these fields, | |
246 | * so we convert them here | |
247 | */ | |
248 | int err; | |
249 | long long f_blocks; | |
250 | long long f_bfree; | |
251 | long long f_bavail; | |
252 | long long f_files; | |
253 | long long f_ffree; | |
254 | ||
255 | err = do_statfs(HOSTFS_I(sb->s_root->d_inode)->host_filename, | |
256 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, | |
257 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
258 | &sf->f_namelen, sf->f_spare); | |
259 | if(err) return(err); | |
260 | sf->f_blocks = f_blocks; | |
261 | sf->f_bfree = f_bfree; | |
262 | sf->f_bavail = f_bavail; | |
263 | sf->f_files = f_files; | |
264 | sf->f_ffree = f_ffree; | |
265 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
266 | return(0); | |
267 | } | |
268 | ||
269 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
270 | { | |
271 | struct hostfs_inode_info *hi; | |
272 | ||
273 | hi = kmalloc(sizeof(*hi), GFP_KERNEL); | |
274 | if(hi == NULL) | |
275 | return(NULL); | |
276 | ||
277 | *hi = ((struct hostfs_inode_info) { .host_filename = NULL, | |
278 | .fd = -1, | |
279 | .mode = 0 }); | |
280 | inode_init_once(&hi->vfs_inode); | |
281 | return(&hi->vfs_inode); | |
282 | } | |
283 | ||
284 | static void hostfs_delete_inode(struct inode *inode) | |
285 | { | |
fef26658 | 286 | truncate_inode_pages(&inode->i_data, 0); |
1da177e4 LT |
287 | if(HOSTFS_I(inode)->fd != -1) { |
288 | close_file(&HOSTFS_I(inode)->fd); | |
289 | HOSTFS_I(inode)->fd = -1; | |
290 | } | |
291 | clear_inode(inode); | |
292 | } | |
293 | ||
294 | static void hostfs_destroy_inode(struct inode *inode) | |
295 | { | |
f99d49ad | 296 | kfree(HOSTFS_I(inode)->host_filename); |
1da177e4 LT |
297 | |
298 | /*XXX: This should not happen, probably. The check is here for | |
299 | * additional safety.*/ | |
300 | if(HOSTFS_I(inode)->fd != -1) { | |
301 | close_file(&HOSTFS_I(inode)->fd); | |
302 | printk(KERN_DEBUG "Closing host fd in .destroy_inode\n"); | |
303 | } | |
304 | ||
305 | kfree(HOSTFS_I(inode)); | |
306 | } | |
307 | ||
308 | static void hostfs_read_inode(struct inode *inode) | |
309 | { | |
310 | read_inode(inode); | |
311 | } | |
312 | ||
313 | static struct super_operations hostfs_sbops = { | |
314 | .alloc_inode = hostfs_alloc_inode, | |
315 | .drop_inode = generic_delete_inode, | |
316 | .delete_inode = hostfs_delete_inode, | |
317 | .destroy_inode = hostfs_destroy_inode, | |
318 | .read_inode = hostfs_read_inode, | |
319 | .statfs = hostfs_statfs, | |
320 | }; | |
321 | ||
322 | int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) | |
323 | { | |
324 | void *dir; | |
325 | char *name; | |
326 | unsigned long long next, ino; | |
327 | int error, len; | |
328 | ||
329 | name = dentry_name(file->f_dentry, 0); | |
330 | if(name == NULL) return(-ENOMEM); | |
331 | dir = open_dir(name, &error); | |
332 | kfree(name); | |
333 | if(dir == NULL) return(-error); | |
334 | next = file->f_pos; | |
335 | while((name = read_dir(dir, &next, &ino, &len)) != NULL){ | |
336 | error = (*filldir)(ent, name, len, file->f_pos, | |
337 | ino, DT_UNKNOWN); | |
338 | if(error) break; | |
339 | file->f_pos = next; | |
340 | } | |
341 | close_dir(dir); | |
342 | return(0); | |
343 | } | |
344 | ||
345 | int hostfs_file_open(struct inode *ino, struct file *file) | |
346 | { | |
347 | char *name; | |
348 | int mode = 0, r = 0, w = 0, fd; | |
349 | ||
350 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
351 | if((mode & HOSTFS_I(ino)->mode) == mode) | |
352 | return(0); | |
353 | ||
354 | /* The file may already have been opened, but with the wrong access, | |
355 | * so this resets things and reopens the file with the new access. | |
356 | */ | |
357 | if(HOSTFS_I(ino)->fd != -1){ | |
358 | close_file(&HOSTFS_I(ino)->fd); | |
359 | HOSTFS_I(ino)->fd = -1; | |
360 | } | |
361 | ||
362 | HOSTFS_I(ino)->mode |= mode; | |
363 | if(HOSTFS_I(ino)->mode & FMODE_READ) | |
364 | r = 1; | |
365 | if(HOSTFS_I(ino)->mode & FMODE_WRITE) | |
366 | w = 1; | |
367 | if(w) | |
368 | r = 1; | |
369 | ||
370 | name = dentry_name(file->f_dentry, 0); | |
371 | if(name == NULL) | |
372 | return(-ENOMEM); | |
373 | ||
374 | fd = open_file(name, r, w, append); | |
375 | kfree(name); | |
376 | if(fd < 0) return(fd); | |
377 | FILE_HOSTFS_I(file)->fd = fd; | |
378 | ||
379 | return(0); | |
380 | } | |
381 | ||
382 | int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync) | |
383 | { | |
a2d76bd8 | 384 | return fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync); |
1da177e4 LT |
385 | } |
386 | ||
4b6f5d20 | 387 | static const struct file_operations hostfs_file_fops = { |
1da177e4 LT |
388 | .llseek = generic_file_llseek, |
389 | .read = generic_file_read, | |
390 | .sendfile = generic_file_sendfile, | |
391 | .aio_read = generic_file_aio_read, | |
392 | .aio_write = generic_file_aio_write, | |
393 | .readv = generic_file_readv, | |
394 | .writev = generic_file_writev, | |
395 | .write = generic_file_write, | |
396 | .mmap = generic_file_mmap, | |
397 | .open = hostfs_file_open, | |
398 | .release = NULL, | |
399 | .fsync = hostfs_fsync, | |
400 | }; | |
401 | ||
4b6f5d20 | 402 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
403 | .llseek = generic_file_llseek, |
404 | .readdir = hostfs_readdir, | |
405 | .read = generic_read_dir, | |
406 | }; | |
407 | ||
408 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
409 | { | |
410 | struct address_space *mapping = page->mapping; | |
411 | struct inode *inode = mapping->host; | |
412 | char *buffer; | |
413 | unsigned long long base; | |
414 | int count = PAGE_CACHE_SIZE; | |
415 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
416 | int err; | |
417 | ||
418 | if (page->index >= end_index) | |
419 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
420 | ||
421 | buffer = kmap(page); | |
422 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
423 | ||
424 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
425 | if(err != count){ | |
426 | ClearPageUptodate(page); | |
427 | goto out; | |
428 | } | |
429 | ||
430 | if (base > inode->i_size) | |
431 | inode->i_size = base; | |
432 | ||
433 | if (PageError(page)) | |
434 | ClearPageError(page); | |
435 | err = 0; | |
436 | ||
437 | out: | |
438 | kunmap(page); | |
439 | ||
440 | unlock_page(page); | |
441 | return err; | |
442 | } | |
443 | ||
444 | int hostfs_readpage(struct file *file, struct page *page) | |
445 | { | |
446 | char *buffer; | |
447 | long long start; | |
448 | int err = 0; | |
449 | ||
450 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
451 | buffer = kmap(page); | |
452 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
453 | PAGE_CACHE_SIZE); | |
454 | if(err < 0) goto out; | |
455 | ||
456 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
457 | ||
458 | flush_dcache_page(page); | |
459 | SetPageUptodate(page); | |
460 | if (PageError(page)) ClearPageError(page); | |
461 | err = 0; | |
462 | out: | |
463 | kunmap(page); | |
464 | unlock_page(page); | |
465 | return(err); | |
466 | } | |
467 | ||
468 | int hostfs_prepare_write(struct file *file, struct page *page, | |
469 | unsigned int from, unsigned int to) | |
470 | { | |
471 | char *buffer; | |
472 | long long start, tmp; | |
473 | int err; | |
474 | ||
475 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
476 | buffer = kmap(page); | |
477 | if(from != 0){ | |
478 | tmp = start; | |
479 | err = read_file(FILE_HOSTFS_I(file)->fd, &tmp, buffer, | |
480 | from); | |
481 | if(err < 0) goto out; | |
482 | } | |
483 | if(to != PAGE_CACHE_SIZE){ | |
484 | start += to; | |
485 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer + to, | |
486 | PAGE_CACHE_SIZE - to); | |
487 | if(err < 0) goto out; | |
488 | } | |
489 | err = 0; | |
490 | out: | |
491 | kunmap(page); | |
492 | return(err); | |
493 | } | |
494 | ||
495 | int hostfs_commit_write(struct file *file, struct page *page, unsigned from, | |
496 | unsigned to) | |
497 | { | |
498 | struct address_space *mapping = page->mapping; | |
499 | struct inode *inode = mapping->host; | |
500 | char *buffer; | |
501 | long long start; | |
502 | int err = 0; | |
503 | ||
30f04a4e | 504 | start = (((long long) page->index) << PAGE_CACHE_SHIFT) + from; |
1da177e4 LT |
505 | buffer = kmap(page); |
506 | err = write_file(FILE_HOSTFS_I(file)->fd, &start, buffer + from, | |
507 | to - from); | |
508 | if(err > 0) err = 0; | |
30f04a4e PBG |
509 | |
510 | /* Actually, if !err, write_file has added to-from to start, so, despite | |
511 | * the appearance, we are comparing i_size against the _last_ written | |
512 | * location, as we should. */ | |
513 | ||
1da177e4 LT |
514 | if(!err && (start > inode->i_size)) |
515 | inode->i_size = start; | |
516 | ||
517 | kunmap(page); | |
518 | return(err); | |
519 | } | |
520 | ||
521 | static struct address_space_operations hostfs_aops = { | |
522 | .writepage = hostfs_writepage, | |
523 | .readpage = hostfs_readpage, | |
ffa0aea6 | 524 | .set_page_dirty = __set_page_dirty_nobuffers, |
1da177e4 LT |
525 | .prepare_write = hostfs_prepare_write, |
526 | .commit_write = hostfs_commit_write | |
527 | }; | |
528 | ||
529 | static int init_inode(struct inode *inode, struct dentry *dentry) | |
530 | { | |
531 | char *name; | |
532 | int type, err = -ENOMEM; | |
533 | int maj, min; | |
534 | dev_t rdev = 0; | |
535 | ||
536 | if(dentry){ | |
537 | name = dentry_name(dentry, 0); | |
538 | if(name == NULL) | |
539 | goto out; | |
540 | type = file_type(name, &maj, &min); | |
541 | /*Reencode maj and min with the kernel encoding.*/ | |
542 | rdev = MKDEV(maj, min); | |
543 | kfree(name); | |
544 | } | |
545 | else type = OS_TYPE_DIR; | |
546 | ||
547 | err = 0; | |
548 | if(type == OS_TYPE_SYMLINK) | |
549 | inode->i_op = &page_symlink_inode_operations; | |
550 | else if(type == OS_TYPE_DIR) | |
551 | inode->i_op = &hostfs_dir_iops; | |
552 | else inode->i_op = &hostfs_iops; | |
553 | ||
554 | if(type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; | |
555 | else inode->i_fop = &hostfs_file_fops; | |
556 | ||
557 | if(type == OS_TYPE_SYMLINK) | |
558 | inode->i_mapping->a_ops = &hostfs_link_aops; | |
559 | else inode->i_mapping->a_ops = &hostfs_aops; | |
560 | ||
561 | switch (type) { | |
562 | case OS_TYPE_CHARDEV: | |
563 | init_special_inode(inode, S_IFCHR, rdev); | |
564 | break; | |
565 | case OS_TYPE_BLOCKDEV: | |
566 | init_special_inode(inode, S_IFBLK, rdev); | |
567 | break; | |
568 | case OS_TYPE_FIFO: | |
569 | init_special_inode(inode, S_IFIFO, 0); | |
570 | break; | |
571 | case OS_TYPE_SOCK: | |
572 | init_special_inode(inode, S_IFSOCK, 0); | |
573 | break; | |
574 | } | |
575 | out: | |
576 | return(err); | |
577 | } | |
578 | ||
579 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
580 | struct nameidata *nd) | |
581 | { | |
582 | struct inode *inode; | |
583 | char *name; | |
584 | int error, fd; | |
585 | ||
586 | error = -ENOMEM; | |
587 | inode = iget(dir->i_sb, 0); | |
588 | if(inode == NULL) goto out; | |
589 | ||
590 | error = init_inode(inode, dentry); | |
591 | if(error) | |
592 | goto out_put; | |
593 | ||
594 | error = -ENOMEM; | |
595 | name = dentry_name(dentry, 0); | |
596 | if(name == NULL) | |
597 | goto out_put; | |
598 | ||
599 | fd = file_create(name, | |
600 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
601 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
602 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
603 | if(fd < 0) | |
604 | error = fd; | |
605 | else error = read_name(inode, name); | |
606 | ||
607 | kfree(name); | |
608 | if(error) | |
609 | goto out_put; | |
610 | ||
611 | HOSTFS_I(inode)->fd = fd; | |
612 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
613 | d_instantiate(dentry, inode); | |
614 | return(0); | |
615 | ||
616 | out_put: | |
617 | iput(inode); | |
618 | out: | |
619 | return(error); | |
620 | } | |
621 | ||
622 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
623 | struct nameidata *nd) | |
624 | { | |
625 | struct inode *inode; | |
626 | char *name; | |
627 | int err; | |
628 | ||
629 | err = -ENOMEM; | |
630 | inode = iget(ino->i_sb, 0); | |
631 | if(inode == NULL) | |
632 | goto out; | |
633 | ||
634 | err = init_inode(inode, dentry); | |
635 | if(err) | |
636 | goto out_put; | |
637 | ||
638 | err = -ENOMEM; | |
639 | name = dentry_name(dentry, 0); | |
640 | if(name == NULL) | |
641 | goto out_put; | |
642 | ||
643 | err = read_name(inode, name); | |
644 | kfree(name); | |
645 | if(err == -ENOENT){ | |
646 | iput(inode); | |
647 | inode = NULL; | |
648 | } | |
649 | else if(err) | |
650 | goto out_put; | |
651 | ||
652 | d_add(dentry, inode); | |
653 | dentry->d_op = &hostfs_dentry_ops; | |
654 | return(NULL); | |
655 | ||
656 | out_put: | |
657 | iput(inode); | |
658 | out: | |
659 | return(ERR_PTR(err)); | |
660 | } | |
661 | ||
662 | static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) | |
663 | { | |
664 | char *file; | |
665 | int len; | |
666 | ||
667 | file = inode_name(ino, dentry->d_name.len + 1); | |
668 | if(file == NULL) return(NULL); | |
669 | strcat(file, "/"); | |
670 | len = strlen(file); | |
671 | strncat(file, dentry->d_name.name, dentry->d_name.len); | |
672 | file[len + dentry->d_name.len] = '\0'; | |
673 | return(file); | |
674 | } | |
675 | ||
676 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) | |
677 | { | |
678 | char *from_name, *to_name; | |
679 | int err; | |
680 | ||
681 | if((from_name = inode_dentry_name(ino, from)) == NULL) | |
682 | return(-ENOMEM); | |
683 | to_name = dentry_name(to, 0); | |
684 | if(to_name == NULL){ | |
685 | kfree(from_name); | |
686 | return(-ENOMEM); | |
687 | } | |
688 | err = link_file(to_name, from_name); | |
689 | kfree(from_name); | |
690 | kfree(to_name); | |
691 | return(err); | |
692 | } | |
693 | ||
694 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
695 | { | |
696 | char *file; | |
697 | int err; | |
698 | ||
699 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
700 | if(append) | |
701 | return(-EPERM); | |
702 | ||
703 | err = unlink_file(file); | |
704 | kfree(file); | |
705 | return(err); | |
706 | } | |
707 | ||
708 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
709 | { | |
710 | char *file; | |
711 | int err; | |
712 | ||
713 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
714 | err = make_symlink(file, to); | |
715 | kfree(file); | |
716 | return(err); | |
717 | } | |
718 | ||
719 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
720 | { | |
721 | char *file; | |
722 | int err; | |
723 | ||
724 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
725 | err = do_mkdir(file, mode); | |
726 | kfree(file); | |
727 | return(err); | |
728 | } | |
729 | ||
730 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
731 | { | |
732 | char *file; | |
733 | int err; | |
734 | ||
735 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
736 | err = do_rmdir(file); | |
737 | kfree(file); | |
738 | return(err); | |
739 | } | |
740 | ||
741 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
742 | { | |
743 | struct inode *inode; | |
744 | char *name; | |
745 | int err = -ENOMEM; | |
746 | ||
747 | inode = iget(dir->i_sb, 0); | |
748 | if(inode == NULL) | |
749 | goto out; | |
750 | ||
751 | err = init_inode(inode, dentry); | |
752 | if(err) | |
753 | goto out_put; | |
754 | ||
755 | err = -ENOMEM; | |
756 | name = dentry_name(dentry, 0); | |
757 | if(name == NULL) | |
758 | goto out_put; | |
759 | ||
760 | init_special_inode(inode, mode, dev); | |
761 | err = do_mknod(name, mode, dev); | |
762 | if(err) | |
763 | goto out_free; | |
764 | ||
765 | err = read_name(inode, name); | |
766 | kfree(name); | |
767 | if(err) | |
768 | goto out_put; | |
769 | ||
770 | d_instantiate(dentry, inode); | |
771 | return(0); | |
772 | ||
773 | out_free: | |
774 | kfree(name); | |
775 | out_put: | |
776 | iput(inode); | |
777 | out: | |
778 | return(err); | |
779 | } | |
780 | ||
781 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
782 | struct inode *to_ino, struct dentry *to) | |
783 | { | |
784 | char *from_name, *to_name; | |
785 | int err; | |
786 | ||
787 | if((from_name = inode_dentry_name(from_ino, from)) == NULL) | |
788 | return(-ENOMEM); | |
789 | if((to_name = inode_dentry_name(to_ino, to)) == NULL){ | |
790 | kfree(from_name); | |
791 | return(-ENOMEM); | |
792 | } | |
793 | err = rename_file(from_name, to_name); | |
794 | kfree(from_name); | |
795 | kfree(to_name); | |
796 | return(err); | |
797 | } | |
798 | ||
1da177e4 LT |
799 | int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) |
800 | { | |
801 | char *name; | |
802 | int r = 0, w = 0, x = 0, err; | |
803 | ||
804 | if (desired & MAY_READ) r = 1; | |
805 | if (desired & MAY_WRITE) w = 1; | |
806 | if (desired & MAY_EXEC) x = 1; | |
807 | name = inode_name(ino, 0); | |
808 | if (name == NULL) return(-ENOMEM); | |
809 | ||
810 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
811 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) | |
812 | err = 0; | |
813 | else | |
814 | err = access_file(name, r, w, x); | |
815 | kfree(name); | |
816 | if(!err) | |
817 | err = generic_permission(ino, desired, NULL); | |
818 | return err; | |
819 | } | |
820 | ||
821 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
822 | { | |
823 | struct hostfs_iattr attrs; | |
824 | char *name; | |
825 | int err; | |
826 | ||
827 | err = inode_change_ok(dentry->d_inode, attr); | |
828 | if (err) | |
829 | return err; | |
830 | ||
831 | if(append) | |
832 | attr->ia_valid &= ~ATTR_SIZE; | |
833 | ||
834 | attrs.ia_valid = 0; | |
835 | if(attr->ia_valid & ATTR_MODE){ | |
836 | attrs.ia_valid |= HOSTFS_ATTR_MODE; | |
837 | attrs.ia_mode = attr->ia_mode; | |
838 | } | |
839 | if(attr->ia_valid & ATTR_UID){ | |
1da177e4 LT |
840 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
841 | attrs.ia_uid = attr->ia_uid; | |
842 | } | |
843 | if(attr->ia_valid & ATTR_GID){ | |
1da177e4 LT |
844 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
845 | attrs.ia_gid = attr->ia_gid; | |
846 | } | |
847 | if(attr->ia_valid & ATTR_SIZE){ | |
848 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; | |
849 | attrs.ia_size = attr->ia_size; | |
850 | } | |
851 | if(attr->ia_valid & ATTR_ATIME){ | |
852 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; | |
853 | attrs.ia_atime = attr->ia_atime; | |
854 | } | |
855 | if(attr->ia_valid & ATTR_MTIME){ | |
856 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; | |
857 | attrs.ia_mtime = attr->ia_mtime; | |
858 | } | |
859 | if(attr->ia_valid & ATTR_CTIME){ | |
860 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; | |
861 | attrs.ia_ctime = attr->ia_ctime; | |
862 | } | |
863 | if(attr->ia_valid & ATTR_ATIME_SET){ | |
864 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; | |
865 | } | |
866 | if(attr->ia_valid & ATTR_MTIME_SET){ | |
867 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; | |
868 | } | |
869 | name = dentry_name(dentry, 0); | |
870 | if(name == NULL) return(-ENOMEM); | |
871 | err = set_attr(name, &attrs); | |
872 | kfree(name); | |
873 | if(err) | |
874 | return(err); | |
875 | ||
876 | return(inode_setattr(dentry->d_inode, attr)); | |
877 | } | |
878 | ||
879 | int hostfs_getattr(struct vfsmount *mnt, struct dentry *dentry, | |
880 | struct kstat *stat) | |
881 | { | |
882 | generic_fillattr(dentry->d_inode, stat); | |
883 | return(0); | |
884 | } | |
885 | ||
886 | static struct inode_operations hostfs_iops = { | |
887 | .create = hostfs_create, | |
888 | .link = hostfs_link, | |
889 | .unlink = hostfs_unlink, | |
890 | .symlink = hostfs_symlink, | |
891 | .mkdir = hostfs_mkdir, | |
892 | .rmdir = hostfs_rmdir, | |
893 | .mknod = hostfs_mknod, | |
894 | .rename = hostfs_rename, | |
1da177e4 LT |
895 | .permission = hostfs_permission, |
896 | .setattr = hostfs_setattr, | |
897 | .getattr = hostfs_getattr, | |
898 | }; | |
899 | ||
900 | static struct inode_operations hostfs_dir_iops = { | |
901 | .create = hostfs_create, | |
902 | .lookup = hostfs_lookup, | |
903 | .link = hostfs_link, | |
904 | .unlink = hostfs_unlink, | |
905 | .symlink = hostfs_symlink, | |
906 | .mkdir = hostfs_mkdir, | |
907 | .rmdir = hostfs_rmdir, | |
908 | .mknod = hostfs_mknod, | |
909 | .rename = hostfs_rename, | |
1da177e4 LT |
910 | .permission = hostfs_permission, |
911 | .setattr = hostfs_setattr, | |
912 | .getattr = hostfs_getattr, | |
913 | }; | |
914 | ||
915 | int hostfs_link_readpage(struct file *file, struct page *page) | |
916 | { | |
917 | char *buffer, *name; | |
1da177e4 LT |
918 | int err; |
919 | ||
1da177e4 LT |
920 | buffer = kmap(page); |
921 | name = inode_name(page->mapping->host, 0); | |
922 | if(name == NULL) return(-ENOMEM); | |
923 | err = do_readlink(name, buffer, PAGE_CACHE_SIZE); | |
924 | kfree(name); | |
925 | if(err == PAGE_CACHE_SIZE) | |
926 | err = -E2BIG; | |
927 | else if(err > 0){ | |
928 | flush_dcache_page(page); | |
929 | SetPageUptodate(page); | |
930 | if (PageError(page)) ClearPageError(page); | |
931 | err = 0; | |
932 | } | |
933 | kunmap(page); | |
934 | unlock_page(page); | |
935 | return(err); | |
936 | } | |
937 | ||
938 | static struct address_space_operations hostfs_link_aops = { | |
939 | .readpage = hostfs_link_readpage, | |
940 | }; | |
941 | ||
942 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
943 | { | |
944 | struct inode *root_inode; | |
945 | char *name, *data = d; | |
946 | int err; | |
947 | ||
948 | sb->s_blocksize = 1024; | |
949 | sb->s_blocksize_bits = 10; | |
950 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
951 | sb->s_op = &hostfs_sbops; | |
952 | ||
953 | if((data == NULL) || (*data == '\0')) | |
954 | data = root_ino; | |
955 | ||
956 | err = -ENOMEM; | |
957 | name = kmalloc(strlen(data) + 1, GFP_KERNEL); | |
958 | if(name == NULL) | |
959 | goto out; | |
960 | ||
961 | strcpy(name, data); | |
962 | ||
963 | root_inode = iget(sb, 0); | |
964 | if(root_inode == NULL) | |
965 | goto out_free; | |
966 | ||
967 | err = init_inode(root_inode, NULL); | |
968 | if(err) | |
969 | goto out_put; | |
970 | ||
971 | HOSTFS_I(root_inode)->host_filename = name; | |
972 | ||
973 | err = -ENOMEM; | |
974 | sb->s_root = d_alloc_root(root_inode); | |
975 | if(sb->s_root == NULL) | |
976 | goto out_put; | |
977 | ||
978 | err = read_inode(root_inode); | |
51a14110 JD |
979 | if(err){ |
980 | /* No iput in this case because the dput does that for us */ | |
981 | dput(sb->s_root); | |
982 | sb->s_root = NULL; | |
983 | goto out_free; | |
984 | } | |
1da177e4 LT |
985 | |
986 | return(0); | |
987 | ||
988 | out_put: | |
51a14110 | 989 | iput(root_inode); |
1da177e4 LT |
990 | out_free: |
991 | kfree(name); | |
992 | out: | |
993 | return(err); | |
994 | } | |
995 | ||
454e2398 DH |
996 | static int hostfs_read_sb(struct file_system_type *type, |
997 | int flags, const char *dev_name, | |
998 | void *data, struct vfsmount *mnt) | |
1da177e4 | 999 | { |
454e2398 | 1000 | return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); |
1da177e4 LT |
1001 | } |
1002 | ||
1003 | static struct file_system_type hostfs_type = { | |
1004 | .owner = THIS_MODULE, | |
1005 | .name = "hostfs", | |
1006 | .get_sb = hostfs_read_sb, | |
1007 | .kill_sb = kill_anon_super, | |
1008 | .fs_flags = 0, | |
1009 | }; | |
1010 | ||
1011 | static int __init init_hostfs(void) | |
1012 | { | |
1013 | return(register_filesystem(&hostfs_type)); | |
1014 | } | |
1015 | ||
1016 | static void __exit exit_hostfs(void) | |
1017 | { | |
1018 | unregister_filesystem(&hostfs_type); | |
1019 | } | |
1020 | ||
1021 | module_init(init_hostfs) | |
1022 | module_exit(exit_hostfs) | |
1023 | MODULE_LICENSE("GPL"); | |
1024 | ||
1025 | /* | |
1026 | * Overrides for Emacs so that we follow Linus's tabbing style. | |
1027 | * Emacs will notice this stuff at the end of the file and automatically | |
1028 | * adjust the settings for this buffer only. This must remain at the end | |
1029 | * of the file. | |
1030 | * --------------------------------------------------------------------------- | |
1031 | * Local variables: | |
1032 | * c-file-style: "linux" | |
1033 | * End: | |
1034 | */ |