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Commit | Line | Data |
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1da177e4 | 1 | /* |
f1adc05e | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
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" | |
1da177e4 LT |
23 | #include "init.h" |
24 | ||
25 | struct hostfs_inode_info { | |
26 | char *host_filename; | |
27 | int fd; | |
28 | int mode; | |
29 | struct inode vfs_inode; | |
30 | }; | |
31 | ||
32 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
33 | { | |
f1adc05e | 34 | return list_entry(inode, struct hostfs_inode_info, vfs_inode); |
1da177e4 LT |
35 | } |
36 | ||
680b0da9 | 37 | #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) |
1da177e4 LT |
38 | |
39 | int hostfs_d_delete(struct dentry *dentry) | |
40 | { | |
f1adc05e | 41 | return 1; |
1da177e4 LT |
42 | } |
43 | ||
44 | struct dentry_operations hostfs_dentry_ops = { | |
45 | .d_delete = hostfs_d_delete, | |
46 | }; | |
47 | ||
48 | /* Changed in hostfs_args before the kernel starts running */ | |
a6eb0be6 | 49 | static char *root_ino = ""; |
1da177e4 LT |
50 | static int append = 0; |
51 | ||
52 | #define HOSTFS_SUPER_MAGIC 0x00c0ffee | |
53 | ||
92e1d5be AV |
54 | static const struct inode_operations hostfs_iops; |
55 | static const struct inode_operations hostfs_dir_iops; | |
f5e54d6e | 56 | static const struct address_space_operations hostfs_link_aops; |
1da177e4 LT |
57 | |
58 | #ifndef MODULE | |
59 | static int __init hostfs_args(char *options, int *add) | |
60 | { | |
61 | char *ptr; | |
62 | ||
63 | ptr = strchr(options, ','); | |
64 | if(ptr != NULL) | |
65 | *ptr++ = '\0'; | |
66 | if(*options != '\0') | |
67 | root_ino = options; | |
68 | ||
69 | options = ptr; | |
70 | while(options){ | |
71 | ptr = strchr(options, ','); | |
72 | if(ptr != NULL) | |
73 | *ptr++ = '\0'; | |
74 | if(*options != '\0'){ | |
75 | if(!strcmp(options, "append")) | |
76 | append = 1; | |
77 | else printf("hostfs_args - unsupported option - %s\n", | |
78 | options); | |
79 | } | |
80 | options = ptr; | |
81 | } | |
f1adc05e | 82 | return 0; |
1da177e4 LT |
83 | } |
84 | ||
85 | __uml_setup("hostfs=", hostfs_args, | |
86 | "hostfs=<root dir>,<flags>,...\n" | |
87 | " This is used to set hostfs parameters. The root directory argument\n" | |
88 | " is used to confine all hostfs mounts to within the specified directory\n" | |
89 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
90 | " mount anything on the host that's accessible to the user that's running\n" | |
91 | " it.\n" | |
92 | " The only flag currently supported is 'append', which specifies that all\n" | |
93 | " files opened by hostfs will be opened in append mode.\n\n" | |
94 | ); | |
95 | #endif | |
96 | ||
97 | static char *dentry_name(struct dentry *dentry, int extra) | |
98 | { | |
99 | struct dentry *parent; | |
100 | char *root, *name; | |
101 | int len; | |
102 | ||
103 | len = 0; | |
104 | parent = dentry; | |
105 | while(parent->d_parent != parent){ | |
106 | len += parent->d_name.len + 1; | |
107 | parent = parent->d_parent; | |
108 | } | |
109 | ||
110 | root = HOSTFS_I(parent->d_inode)->host_filename; | |
111 | len += strlen(root); | |
112 | name = kmalloc(len + extra + 1, GFP_KERNEL); | |
f1adc05e JD |
113 | if(name == NULL) |
114 | return NULL; | |
1da177e4 LT |
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)); | |
f1adc05e | 126 | return name; |
1da177e4 LT |
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); | |
f1adc05e | 134 | return dentry_name(dentry, extra); |
1da177e4 LT |
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, | |
5822b7fa | 151 | &ino->i_ctime, &i_blksize, &i_blocks, -1); |
1da177e4 | 152 | if(err) |
f1adc05e | 153 | return err; |
1da177e4 LT |
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; |
f1adc05e | 160 | return 0; |
1da177e4 LT |
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 == '/') | |
f1adc05e | 185 | return name; |
1da177e4 LT |
186 | |
187 | end = strrchr(link, '/'); | |
188 | if(end == NULL) | |
f1adc05e | 189 | return name; |
1da177e4 LT |
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); | |
f1adc05e | 203 | return resolved; |
1da177e4 LT |
204 | |
205 | out_free: | |
206 | kfree(name); | |
207 | out: | |
f1adc05e | 208 | return ERR_PTR(n); |
1da177e4 LT |
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: | |
f1adc05e | 238 | return err; |
1da177e4 LT |
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); | |
f1adc05e JD |
258 | if(err) |
259 | return err; | |
1da177e4 LT |
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; | |
f1adc05e | 266 | return 0; |
1da177e4 LT |
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) | |
f1adc05e | 275 | return NULL; |
1da177e4 LT |
276 | |
277 | *hi = ((struct hostfs_inode_info) { .host_filename = NULL, | |
278 | .fd = -1, | |
279 | .mode = 0 }); | |
280 | inode_init_once(&hi->vfs_inode); | |
f1adc05e | 281 | return &hi->vfs_inode; |
1da177e4 LT |
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 | ||
ee9b6d61 | 313 | static const struct super_operations hostfs_sbops = { |
1da177e4 LT |
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 | ||
680b0da9 | 329 | name = dentry_name(file->f_path.dentry, 0); |
f1adc05e JD |
330 | if(name == NULL) |
331 | return -ENOMEM; | |
1da177e4 LT |
332 | dir = open_dir(name, &error); |
333 | kfree(name); | |
f1adc05e JD |
334 | if(dir == NULL) |
335 | return -error; | |
1da177e4 LT |
336 | next = file->f_pos; |
337 | while((name = read_dir(dir, &next, &ino, &len)) != NULL){ | |
338 | error = (*filldir)(ent, name, len, file->f_pos, | |
339 | ino, DT_UNKNOWN); | |
340 | if(error) break; | |
341 | file->f_pos = next; | |
342 | } | |
343 | close_dir(dir); | |
f1adc05e | 344 | return 0; |
1da177e4 LT |
345 | } |
346 | ||
347 | int hostfs_file_open(struct inode *ino, struct file *file) | |
348 | { | |
349 | char *name; | |
350 | int mode = 0, r = 0, w = 0, fd; | |
351 | ||
352 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
353 | if((mode & HOSTFS_I(ino)->mode) == mode) | |
f1adc05e | 354 | return 0; |
1da177e4 LT |
355 | |
356 | /* The file may already have been opened, but with the wrong access, | |
357 | * so this resets things and reopens the file with the new access. | |
358 | */ | |
359 | if(HOSTFS_I(ino)->fd != -1){ | |
360 | close_file(&HOSTFS_I(ino)->fd); | |
361 | HOSTFS_I(ino)->fd = -1; | |
362 | } | |
363 | ||
364 | HOSTFS_I(ino)->mode |= mode; | |
365 | if(HOSTFS_I(ino)->mode & FMODE_READ) | |
366 | r = 1; | |
367 | if(HOSTFS_I(ino)->mode & FMODE_WRITE) | |
368 | w = 1; | |
369 | if(w) | |
370 | r = 1; | |
371 | ||
680b0da9 | 372 | name = dentry_name(file->f_path.dentry, 0); |
1da177e4 | 373 | if(name == NULL) |
f1adc05e | 374 | return -ENOMEM; |
1da177e4 LT |
375 | |
376 | fd = open_file(name, r, w, append); | |
377 | kfree(name); | |
f1adc05e JD |
378 | if(fd < 0) |
379 | return fd; | |
1da177e4 LT |
380 | FILE_HOSTFS_I(file)->fd = fd; |
381 | ||
f1adc05e | 382 | return 0; |
1da177e4 LT |
383 | } |
384 | ||
385 | int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync) | |
386 | { | |
a2d76bd8 | 387 | return fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync); |
1da177e4 LT |
388 | } |
389 | ||
4b6f5d20 | 390 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 391 | .llseek = generic_file_llseek, |
543ade1f | 392 | .read = do_sync_read, |
5ffc4ef4 | 393 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
394 | .aio_read = generic_file_aio_read, |
395 | .aio_write = generic_file_aio_write, | |
543ade1f | 396 | .write = do_sync_write, |
1da177e4 LT |
397 | .mmap = generic_file_mmap, |
398 | .open = hostfs_file_open, | |
399 | .release = NULL, | |
400 | .fsync = hostfs_fsync, | |
401 | }; | |
402 | ||
4b6f5d20 | 403 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
404 | .llseek = generic_file_llseek, |
405 | .readdir = hostfs_readdir, | |
406 | .read = generic_read_dir, | |
407 | }; | |
408 | ||
409 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
410 | { | |
411 | struct address_space *mapping = page->mapping; | |
412 | struct inode *inode = mapping->host; | |
413 | char *buffer; | |
414 | unsigned long long base; | |
415 | int count = PAGE_CACHE_SIZE; | |
416 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
417 | int err; | |
418 | ||
419 | if (page->index >= end_index) | |
420 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
421 | ||
422 | buffer = kmap(page); | |
423 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
424 | ||
425 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
426 | if(err != count){ | |
427 | ClearPageUptodate(page); | |
428 | goto out; | |
429 | } | |
430 | ||
431 | if (base > inode->i_size) | |
432 | inode->i_size = base; | |
433 | ||
434 | if (PageError(page)) | |
435 | ClearPageError(page); | |
436 | err = 0; | |
437 | ||
438 | out: | |
439 | kunmap(page); | |
440 | ||
441 | unlock_page(page); | |
442 | return err; | |
443 | } | |
444 | ||
445 | int hostfs_readpage(struct file *file, struct page *page) | |
446 | { | |
447 | char *buffer; | |
448 | long long start; | |
449 | int err = 0; | |
450 | ||
451 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
452 | buffer = kmap(page); | |
453 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
454 | PAGE_CACHE_SIZE); | |
455 | if(err < 0) goto out; | |
456 | ||
457 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
458 | ||
459 | flush_dcache_page(page); | |
460 | SetPageUptodate(page); | |
461 | if (PageError(page)) ClearPageError(page); | |
462 | err = 0; | |
463 | out: | |
464 | kunmap(page); | |
465 | unlock_page(page); | |
f1adc05e | 466 | return err; |
1da177e4 LT |
467 | } |
468 | ||
469 | int hostfs_prepare_write(struct file *file, struct page *page, | |
470 | unsigned int from, unsigned int to) | |
471 | { | |
472 | char *buffer; | |
473 | long long start, tmp; | |
474 | int err; | |
475 | ||
476 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
477 | buffer = kmap(page); | |
478 | if(from != 0){ | |
479 | tmp = start; | |
480 | err = read_file(FILE_HOSTFS_I(file)->fd, &tmp, buffer, | |
481 | from); | |
482 | if(err < 0) goto out; | |
483 | } | |
484 | if(to != PAGE_CACHE_SIZE){ | |
485 | start += to; | |
486 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer + to, | |
487 | PAGE_CACHE_SIZE - to); | |
488 | if(err < 0) goto out; | |
489 | } | |
490 | err = 0; | |
491 | out: | |
492 | kunmap(page); | |
f1adc05e | 493 | return err; |
1da177e4 LT |
494 | } |
495 | ||
496 | int hostfs_commit_write(struct file *file, struct page *page, unsigned from, | |
497 | unsigned to) | |
498 | { | |
499 | struct address_space *mapping = page->mapping; | |
500 | struct inode *inode = mapping->host; | |
501 | char *buffer; | |
502 | long long start; | |
503 | int err = 0; | |
504 | ||
30f04a4e | 505 | start = (((long long) page->index) << PAGE_CACHE_SHIFT) + from; |
1da177e4 LT |
506 | buffer = kmap(page); |
507 | err = write_file(FILE_HOSTFS_I(file)->fd, &start, buffer + from, | |
508 | to - from); | |
509 | if(err > 0) err = 0; | |
30f04a4e PBG |
510 | |
511 | /* Actually, if !err, write_file has added to-from to start, so, despite | |
512 | * the appearance, we are comparing i_size against the _last_ written | |
513 | * location, as we should. */ | |
514 | ||
1da177e4 LT |
515 | if(!err && (start > inode->i_size)) |
516 | inode->i_size = start; | |
517 | ||
518 | kunmap(page); | |
f1adc05e | 519 | return err; |
1da177e4 LT |
520 | } |
521 | ||
f5e54d6e | 522 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
523 | .writepage = hostfs_writepage, |
524 | .readpage = hostfs_readpage, | |
ffa0aea6 | 525 | .set_page_dirty = __set_page_dirty_nobuffers, |
1da177e4 LT |
526 | .prepare_write = hostfs_prepare_write, |
527 | .commit_write = hostfs_commit_write | |
528 | }; | |
529 | ||
530 | static int init_inode(struct inode *inode, struct dentry *dentry) | |
531 | { | |
532 | char *name; | |
533 | int type, err = -ENOMEM; | |
534 | int maj, min; | |
535 | dev_t rdev = 0; | |
536 | ||
537 | if(dentry){ | |
538 | name = dentry_name(dentry, 0); | |
539 | if(name == NULL) | |
540 | goto out; | |
541 | type = file_type(name, &maj, &min); | |
542 | /*Reencode maj and min with the kernel encoding.*/ | |
543 | rdev = MKDEV(maj, min); | |
544 | kfree(name); | |
545 | } | |
546 | else type = OS_TYPE_DIR; | |
547 | ||
548 | err = 0; | |
549 | if(type == OS_TYPE_SYMLINK) | |
550 | inode->i_op = &page_symlink_inode_operations; | |
551 | else if(type == OS_TYPE_DIR) | |
552 | inode->i_op = &hostfs_dir_iops; | |
553 | else inode->i_op = &hostfs_iops; | |
554 | ||
555 | if(type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; | |
556 | else inode->i_fop = &hostfs_file_fops; | |
557 | ||
558 | if(type == OS_TYPE_SYMLINK) | |
559 | inode->i_mapping->a_ops = &hostfs_link_aops; | |
560 | else inode->i_mapping->a_ops = &hostfs_aops; | |
561 | ||
562 | switch (type) { | |
563 | case OS_TYPE_CHARDEV: | |
564 | init_special_inode(inode, S_IFCHR, rdev); | |
565 | break; | |
566 | case OS_TYPE_BLOCKDEV: | |
567 | init_special_inode(inode, S_IFBLK, rdev); | |
568 | break; | |
569 | case OS_TYPE_FIFO: | |
570 | init_special_inode(inode, S_IFIFO, 0); | |
571 | break; | |
572 | case OS_TYPE_SOCK: | |
573 | init_special_inode(inode, S_IFSOCK, 0); | |
574 | break; | |
575 | } | |
576 | out: | |
f1adc05e | 577 | return err; |
1da177e4 LT |
578 | } |
579 | ||
580 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
581 | struct nameidata *nd) | |
582 | { | |
583 | struct inode *inode; | |
584 | char *name; | |
585 | int error, fd; | |
586 | ||
587 | error = -ENOMEM; | |
588 | inode = iget(dir->i_sb, 0); | |
589 | if(inode == NULL) goto out; | |
590 | ||
591 | error = init_inode(inode, dentry); | |
592 | if(error) | |
593 | goto out_put; | |
594 | ||
595 | error = -ENOMEM; | |
596 | name = dentry_name(dentry, 0); | |
597 | if(name == NULL) | |
598 | goto out_put; | |
599 | ||
600 | fd = file_create(name, | |
601 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
602 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
603 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
604 | if(fd < 0) | |
605 | error = fd; | |
606 | else error = read_name(inode, name); | |
607 | ||
608 | kfree(name); | |
609 | if(error) | |
610 | goto out_put; | |
611 | ||
612 | HOSTFS_I(inode)->fd = fd; | |
613 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
614 | d_instantiate(dentry, inode); | |
f1adc05e | 615 | return 0; |
1da177e4 LT |
616 | |
617 | out_put: | |
618 | iput(inode); | |
619 | out: | |
f1adc05e | 620 | return error; |
1da177e4 LT |
621 | } |
622 | ||
623 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
f1adc05e | 624 | struct nameidata *nd) |
1da177e4 LT |
625 | { |
626 | struct inode *inode; | |
627 | char *name; | |
628 | int err; | |
629 | ||
630 | err = -ENOMEM; | |
631 | inode = iget(ino->i_sb, 0); | |
632 | if(inode == NULL) | |
633 | goto out; | |
634 | ||
635 | err = init_inode(inode, dentry); | |
636 | if(err) | |
637 | goto out_put; | |
638 | ||
639 | err = -ENOMEM; | |
640 | name = dentry_name(dentry, 0); | |
641 | if(name == NULL) | |
642 | goto out_put; | |
643 | ||
644 | err = read_name(inode, name); | |
645 | kfree(name); | |
646 | if(err == -ENOENT){ | |
647 | iput(inode); | |
648 | inode = NULL; | |
649 | } | |
650 | else if(err) | |
651 | goto out_put; | |
652 | ||
653 | d_add(dentry, inode); | |
654 | dentry->d_op = &hostfs_dentry_ops; | |
f1adc05e | 655 | return NULL; |
1da177e4 LT |
656 | |
657 | out_put: | |
658 | iput(inode); | |
659 | out: | |
f1adc05e | 660 | return ERR_PTR(err); |
1da177e4 LT |
661 | } |
662 | ||
663 | static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) | |
664 | { | |
f1adc05e | 665 | char *file; |
1da177e4 LT |
666 | int len; |
667 | ||
668 | file = inode_name(ino, dentry->d_name.len + 1); | |
f1adc05e JD |
669 | if(file == NULL) |
670 | return NULL; | |
671 | strcat(file, "/"); | |
1da177e4 | 672 | len = strlen(file); |
f1adc05e | 673 | strncat(file, dentry->d_name.name, dentry->d_name.len); |
1da177e4 | 674 | file[len + dentry->d_name.len] = '\0'; |
f1adc05e | 675 | return file; |
1da177e4 LT |
676 | } |
677 | ||
678 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) | |
679 | { | |
f1adc05e JD |
680 | char *from_name, *to_name; |
681 | int err; | |
1da177e4 | 682 | |
f1adc05e JD |
683 | if((from_name = inode_dentry_name(ino, from)) == NULL) |
684 | return -ENOMEM; | |
685 | to_name = dentry_name(to, 0); | |
1da177e4 LT |
686 | if(to_name == NULL){ |
687 | kfree(from_name); | |
f1adc05e | 688 | return -ENOMEM; |
1da177e4 | 689 | } |
f1adc05e JD |
690 | err = link_file(to_name, from_name); |
691 | kfree(from_name); | |
692 | kfree(to_name); | |
693 | return err; | |
1da177e4 LT |
694 | } |
695 | ||
696 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
697 | { | |
698 | char *file; | |
699 | int err; | |
700 | ||
f1adc05e JD |
701 | if((file = inode_dentry_name(ino, dentry)) == NULL) |
702 | return -ENOMEM; | |
1da177e4 | 703 | if(append) |
f1adc05e | 704 | return -EPERM; |
1da177e4 LT |
705 | |
706 | err = unlink_file(file); | |
707 | kfree(file); | |
f1adc05e | 708 | return err; |
1da177e4 LT |
709 | } |
710 | ||
711 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
712 | { | |
713 | char *file; | |
714 | int err; | |
715 | ||
f1adc05e JD |
716 | if((file = inode_dentry_name(ino, dentry)) == NULL) |
717 | return -ENOMEM; | |
1da177e4 LT |
718 | err = make_symlink(file, to); |
719 | kfree(file); | |
f1adc05e | 720 | return err; |
1da177e4 LT |
721 | } |
722 | ||
723 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
724 | { | |
725 | char *file; | |
726 | int err; | |
727 | ||
f1adc05e JD |
728 | if((file = inode_dentry_name(ino, dentry)) == NULL) |
729 | return -ENOMEM; | |
1da177e4 LT |
730 | err = do_mkdir(file, mode); |
731 | kfree(file); | |
f1adc05e | 732 | return err; |
1da177e4 LT |
733 | } |
734 | ||
735 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
736 | { | |
737 | char *file; | |
738 | int err; | |
739 | ||
f1adc05e JD |
740 | if((file = inode_dentry_name(ino, dentry)) == NULL) |
741 | return -ENOMEM; | |
1da177e4 LT |
742 | err = do_rmdir(file); |
743 | kfree(file); | |
f1adc05e | 744 | return err; |
1da177e4 LT |
745 | } |
746 | ||
747 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
748 | { | |
749 | struct inode *inode; | |
750 | char *name; | |
751 | int err = -ENOMEM; | |
752 | ||
753 | inode = iget(dir->i_sb, 0); | |
754 | if(inode == NULL) | |
755 | goto out; | |
756 | ||
757 | err = init_inode(inode, dentry); | |
758 | if(err) | |
759 | goto out_put; | |
760 | ||
761 | err = -ENOMEM; | |
762 | name = dentry_name(dentry, 0); | |
763 | if(name == NULL) | |
764 | goto out_put; | |
765 | ||
766 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 767 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
1da177e4 LT |
768 | if(err) |
769 | goto out_free; | |
770 | ||
771 | err = read_name(inode, name); | |
772 | kfree(name); | |
773 | if(err) | |
774 | goto out_put; | |
775 | ||
776 | d_instantiate(dentry, inode); | |
f1adc05e | 777 | return 0; |
1da177e4 LT |
778 | |
779 | out_free: | |
780 | kfree(name); | |
781 | out_put: | |
782 | iput(inode); | |
783 | out: | |
f1adc05e | 784 | return err; |
1da177e4 LT |
785 | } |
786 | ||
787 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
788 | struct inode *to_ino, struct dentry *to) | |
789 | { | |
790 | char *from_name, *to_name; | |
791 | int err; | |
792 | ||
793 | if((from_name = inode_dentry_name(from_ino, from)) == NULL) | |
f1adc05e | 794 | return -ENOMEM; |
1da177e4 LT |
795 | if((to_name = inode_dentry_name(to_ino, to)) == NULL){ |
796 | kfree(from_name); | |
f1adc05e | 797 | return -ENOMEM; |
1da177e4 LT |
798 | } |
799 | err = rename_file(from_name, to_name); | |
800 | kfree(from_name); | |
801 | kfree(to_name); | |
f1adc05e | 802 | return err; |
1da177e4 LT |
803 | } |
804 | ||
1da177e4 LT |
805 | int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) |
806 | { | |
807 | char *name; | |
808 | int r = 0, w = 0, x = 0, err; | |
809 | ||
810 | if (desired & MAY_READ) r = 1; | |
811 | if (desired & MAY_WRITE) w = 1; | |
812 | if (desired & MAY_EXEC) x = 1; | |
813 | name = inode_name(ino, 0); | |
f1adc05e JD |
814 | if (name == NULL) |
815 | return -ENOMEM; | |
1da177e4 LT |
816 | |
817 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
818 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) | |
819 | err = 0; | |
820 | else | |
821 | err = access_file(name, r, w, x); | |
822 | kfree(name); | |
823 | if(!err) | |
824 | err = generic_permission(ino, desired, NULL); | |
825 | return err; | |
826 | } | |
827 | ||
828 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
829 | { | |
830 | struct hostfs_iattr attrs; | |
831 | char *name; | |
832 | int err; | |
833 | ||
5822b7fa AB |
834 | int fd = HOSTFS_I(dentry->d_inode)->fd; |
835 | ||
1da177e4 LT |
836 | err = inode_change_ok(dentry->d_inode, attr); |
837 | if (err) | |
838 | return err; | |
839 | ||
840 | if(append) | |
841 | attr->ia_valid &= ~ATTR_SIZE; | |
842 | ||
843 | attrs.ia_valid = 0; | |
844 | if(attr->ia_valid & ATTR_MODE){ | |
845 | attrs.ia_valid |= HOSTFS_ATTR_MODE; | |
846 | attrs.ia_mode = attr->ia_mode; | |
847 | } | |
848 | if(attr->ia_valid & ATTR_UID){ | |
1da177e4 LT |
849 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
850 | attrs.ia_uid = attr->ia_uid; | |
851 | } | |
852 | if(attr->ia_valid & ATTR_GID){ | |
1da177e4 LT |
853 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
854 | attrs.ia_gid = attr->ia_gid; | |
855 | } | |
856 | if(attr->ia_valid & ATTR_SIZE){ | |
857 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; | |
858 | attrs.ia_size = attr->ia_size; | |
859 | } | |
860 | if(attr->ia_valid & ATTR_ATIME){ | |
861 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; | |
862 | attrs.ia_atime = attr->ia_atime; | |
863 | } | |
864 | if(attr->ia_valid & ATTR_MTIME){ | |
865 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; | |
866 | attrs.ia_mtime = attr->ia_mtime; | |
867 | } | |
868 | if(attr->ia_valid & ATTR_CTIME){ | |
869 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; | |
870 | attrs.ia_ctime = attr->ia_ctime; | |
871 | } | |
872 | if(attr->ia_valid & ATTR_ATIME_SET){ | |
873 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; | |
874 | } | |
875 | if(attr->ia_valid & ATTR_MTIME_SET){ | |
876 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; | |
877 | } | |
878 | name = dentry_name(dentry, 0); | |
f1adc05e JD |
879 | if(name == NULL) |
880 | return -ENOMEM; | |
5822b7fa | 881 | err = set_attr(name, &attrs, fd); |
1da177e4 LT |
882 | kfree(name); |
883 | if(err) | |
f1adc05e | 884 | return err; |
1da177e4 | 885 | |
f1adc05e | 886 | return inode_setattr(dentry->d_inode, attr); |
1da177e4 LT |
887 | } |
888 | ||
889 | int hostfs_getattr(struct vfsmount *mnt, struct dentry *dentry, | |
890 | struct kstat *stat) | |
891 | { | |
892 | generic_fillattr(dentry->d_inode, stat); | |
f1adc05e | 893 | return 0; |
1da177e4 LT |
894 | } |
895 | ||
92e1d5be | 896 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
897 | .create = hostfs_create, |
898 | .link = hostfs_link, | |
899 | .unlink = hostfs_unlink, | |
900 | .symlink = hostfs_symlink, | |
901 | .mkdir = hostfs_mkdir, | |
902 | .rmdir = hostfs_rmdir, | |
903 | .mknod = hostfs_mknod, | |
904 | .rename = hostfs_rename, | |
1da177e4 LT |
905 | .permission = hostfs_permission, |
906 | .setattr = hostfs_setattr, | |
907 | .getattr = hostfs_getattr, | |
908 | }; | |
909 | ||
92e1d5be | 910 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
911 | .create = hostfs_create, |
912 | .lookup = hostfs_lookup, | |
913 | .link = hostfs_link, | |
914 | .unlink = hostfs_unlink, | |
915 | .symlink = hostfs_symlink, | |
916 | .mkdir = hostfs_mkdir, | |
917 | .rmdir = hostfs_rmdir, | |
918 | .mknod = hostfs_mknod, | |
919 | .rename = hostfs_rename, | |
1da177e4 LT |
920 | .permission = hostfs_permission, |
921 | .setattr = hostfs_setattr, | |
922 | .getattr = hostfs_getattr, | |
923 | }; | |
924 | ||
925 | int hostfs_link_readpage(struct file *file, struct page *page) | |
926 | { | |
927 | char *buffer, *name; | |
1da177e4 LT |
928 | int err; |
929 | ||
1da177e4 LT |
930 | buffer = kmap(page); |
931 | name = inode_name(page->mapping->host, 0); | |
f1adc05e JD |
932 | if(name == NULL) |
933 | return -ENOMEM; | |
1da177e4 LT |
934 | err = do_readlink(name, buffer, PAGE_CACHE_SIZE); |
935 | kfree(name); | |
936 | if(err == PAGE_CACHE_SIZE) | |
937 | err = -E2BIG; | |
938 | else if(err > 0){ | |
939 | flush_dcache_page(page); | |
940 | SetPageUptodate(page); | |
941 | if (PageError(page)) ClearPageError(page); | |
942 | err = 0; | |
943 | } | |
944 | kunmap(page); | |
945 | unlock_page(page); | |
f1adc05e | 946 | return err; |
1da177e4 LT |
947 | } |
948 | ||
f5e54d6e | 949 | static const struct address_space_operations hostfs_link_aops = { |
1da177e4 LT |
950 | .readpage = hostfs_link_readpage, |
951 | }; | |
952 | ||
953 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
954 | { | |
955 | struct inode *root_inode; | |
75e8defb | 956 | char *host_root_path, *req_root = d; |
1da177e4 LT |
957 | int err; |
958 | ||
959 | sb->s_blocksize = 1024; | |
960 | sb->s_blocksize_bits = 10; | |
961 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
962 | sb->s_op = &hostfs_sbops; | |
963 | ||
a6eb0be6 | 964 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
965 | if (req_root == NULL) |
966 | req_root = ""; | |
1da177e4 LT |
967 | |
968 | err = -ENOMEM; | |
75e8defb PBG |
969 | host_root_path = kmalloc(strlen(root_ino) + 1 |
970 | + strlen(req_root) + 1, GFP_KERNEL); | |
971 | if(host_root_path == NULL) | |
1da177e4 LT |
972 | goto out; |
973 | ||
75e8defb | 974 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 LT |
975 | |
976 | root_inode = iget(sb, 0); | |
977 | if(root_inode == NULL) | |
978 | goto out_free; | |
979 | ||
980 | err = init_inode(root_inode, NULL); | |
981 | if(err) | |
982 | goto out_put; | |
983 | ||
75e8defb PBG |
984 | HOSTFS_I(root_inode)->host_filename = host_root_path; |
985 | /* Avoid that in the error path, iput(root_inode) frees again | |
986 | * host_root_path through hostfs_destroy_inode! */ | |
987 | host_root_path = NULL; | |
1da177e4 LT |
988 | |
989 | err = -ENOMEM; | |
990 | sb->s_root = d_alloc_root(root_inode); | |
991 | if(sb->s_root == NULL) | |
992 | goto out_put; | |
993 | ||
994 | err = read_inode(root_inode); | |
51a14110 | 995 | if(err){ |
f1adc05e JD |
996 | /* No iput in this case because the dput does that for us */ |
997 | dput(sb->s_root); | |
998 | sb->s_root = NULL; | |
bca27113 | 999 | goto out; |
f1adc05e | 1000 | } |
1da177e4 | 1001 | |
f1adc05e | 1002 | return 0; |
1da177e4 | 1003 | |
f1adc05e JD |
1004 | out_put: |
1005 | iput(root_inode); | |
1006 | out_free: | |
75e8defb | 1007 | kfree(host_root_path); |
f1adc05e JD |
1008 | out: |
1009 | return err; | |
1da177e4 LT |
1010 | } |
1011 | ||
454e2398 DH |
1012 | static int hostfs_read_sb(struct file_system_type *type, |
1013 | int flags, const char *dev_name, | |
1014 | void *data, struct vfsmount *mnt) | |
1da177e4 | 1015 | { |
454e2398 | 1016 | return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); |
1da177e4 LT |
1017 | } |
1018 | ||
1019 | static struct file_system_type hostfs_type = { | |
1020 | .owner = THIS_MODULE, | |
1021 | .name = "hostfs", | |
1022 | .get_sb = hostfs_read_sb, | |
1023 | .kill_sb = kill_anon_super, | |
1024 | .fs_flags = 0, | |
1025 | }; | |
1026 | ||
1027 | static int __init init_hostfs(void) | |
1028 | { | |
f1adc05e | 1029 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
1030 | } |
1031 | ||
1032 | static void __exit exit_hostfs(void) | |
1033 | { | |
1034 | unregister_filesystem(&hostfs_type); | |
1035 | } | |
1036 | ||
1037 | module_init(init_hostfs) | |
1038 | module_exit(exit_hostfs) | |
1039 | MODULE_LICENSE("GPL"); |