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 | ||
387 | static struct file_operations hostfs_file_fops = { | |
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 | ||
402 | static struct file_operations hostfs_dir_fops = { | |
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 | ||
504 | start = (long long) (page->index << PAGE_CACHE_SHIFT) + from; | |
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; | |
509 | if(!err && (start > inode->i_size)) | |
510 | inode->i_size = start; | |
511 | ||
512 | kunmap(page); | |
513 | return(err); | |
514 | } | |
515 | ||
516 | static struct address_space_operations hostfs_aops = { | |
517 | .writepage = hostfs_writepage, | |
518 | .readpage = hostfs_readpage, | |
ffa0aea6 | 519 | .set_page_dirty = __set_page_dirty_nobuffers, |
1da177e4 LT |
520 | .prepare_write = hostfs_prepare_write, |
521 | .commit_write = hostfs_commit_write | |
522 | }; | |
523 | ||
524 | static int init_inode(struct inode *inode, struct dentry *dentry) | |
525 | { | |
526 | char *name; | |
527 | int type, err = -ENOMEM; | |
528 | int maj, min; | |
529 | dev_t rdev = 0; | |
530 | ||
531 | if(dentry){ | |
532 | name = dentry_name(dentry, 0); | |
533 | if(name == NULL) | |
534 | goto out; | |
535 | type = file_type(name, &maj, &min); | |
536 | /*Reencode maj and min with the kernel encoding.*/ | |
537 | rdev = MKDEV(maj, min); | |
538 | kfree(name); | |
539 | } | |
540 | else type = OS_TYPE_DIR; | |
541 | ||
542 | err = 0; | |
543 | if(type == OS_TYPE_SYMLINK) | |
544 | inode->i_op = &page_symlink_inode_operations; | |
545 | else if(type == OS_TYPE_DIR) | |
546 | inode->i_op = &hostfs_dir_iops; | |
547 | else inode->i_op = &hostfs_iops; | |
548 | ||
549 | if(type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; | |
550 | else inode->i_fop = &hostfs_file_fops; | |
551 | ||
552 | if(type == OS_TYPE_SYMLINK) | |
553 | inode->i_mapping->a_ops = &hostfs_link_aops; | |
554 | else inode->i_mapping->a_ops = &hostfs_aops; | |
555 | ||
556 | switch (type) { | |
557 | case OS_TYPE_CHARDEV: | |
558 | init_special_inode(inode, S_IFCHR, rdev); | |
559 | break; | |
560 | case OS_TYPE_BLOCKDEV: | |
561 | init_special_inode(inode, S_IFBLK, rdev); | |
562 | break; | |
563 | case OS_TYPE_FIFO: | |
564 | init_special_inode(inode, S_IFIFO, 0); | |
565 | break; | |
566 | case OS_TYPE_SOCK: | |
567 | init_special_inode(inode, S_IFSOCK, 0); | |
568 | break; | |
569 | } | |
570 | out: | |
571 | return(err); | |
572 | } | |
573 | ||
574 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
575 | struct nameidata *nd) | |
576 | { | |
577 | struct inode *inode; | |
578 | char *name; | |
579 | int error, fd; | |
580 | ||
581 | error = -ENOMEM; | |
582 | inode = iget(dir->i_sb, 0); | |
583 | if(inode == NULL) goto out; | |
584 | ||
585 | error = init_inode(inode, dentry); | |
586 | if(error) | |
587 | goto out_put; | |
588 | ||
589 | error = -ENOMEM; | |
590 | name = dentry_name(dentry, 0); | |
591 | if(name == NULL) | |
592 | goto out_put; | |
593 | ||
594 | fd = file_create(name, | |
595 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
596 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
597 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
598 | if(fd < 0) | |
599 | error = fd; | |
600 | else error = read_name(inode, name); | |
601 | ||
602 | kfree(name); | |
603 | if(error) | |
604 | goto out_put; | |
605 | ||
606 | HOSTFS_I(inode)->fd = fd; | |
607 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
608 | d_instantiate(dentry, inode); | |
609 | return(0); | |
610 | ||
611 | out_put: | |
612 | iput(inode); | |
613 | out: | |
614 | return(error); | |
615 | } | |
616 | ||
617 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
618 | struct nameidata *nd) | |
619 | { | |
620 | struct inode *inode; | |
621 | char *name; | |
622 | int err; | |
623 | ||
624 | err = -ENOMEM; | |
625 | inode = iget(ino->i_sb, 0); | |
626 | if(inode == NULL) | |
627 | goto out; | |
628 | ||
629 | err = init_inode(inode, dentry); | |
630 | if(err) | |
631 | goto out_put; | |
632 | ||
633 | err = -ENOMEM; | |
634 | name = dentry_name(dentry, 0); | |
635 | if(name == NULL) | |
636 | goto out_put; | |
637 | ||
638 | err = read_name(inode, name); | |
639 | kfree(name); | |
640 | if(err == -ENOENT){ | |
641 | iput(inode); | |
642 | inode = NULL; | |
643 | } | |
644 | else if(err) | |
645 | goto out_put; | |
646 | ||
647 | d_add(dentry, inode); | |
648 | dentry->d_op = &hostfs_dentry_ops; | |
649 | return(NULL); | |
650 | ||
651 | out_put: | |
652 | iput(inode); | |
653 | out: | |
654 | return(ERR_PTR(err)); | |
655 | } | |
656 | ||
657 | static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) | |
658 | { | |
659 | char *file; | |
660 | int len; | |
661 | ||
662 | file = inode_name(ino, dentry->d_name.len + 1); | |
663 | if(file == NULL) return(NULL); | |
664 | strcat(file, "/"); | |
665 | len = strlen(file); | |
666 | strncat(file, dentry->d_name.name, dentry->d_name.len); | |
667 | file[len + dentry->d_name.len] = '\0'; | |
668 | return(file); | |
669 | } | |
670 | ||
671 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) | |
672 | { | |
673 | char *from_name, *to_name; | |
674 | int err; | |
675 | ||
676 | if((from_name = inode_dentry_name(ino, from)) == NULL) | |
677 | return(-ENOMEM); | |
678 | to_name = dentry_name(to, 0); | |
679 | if(to_name == NULL){ | |
680 | kfree(from_name); | |
681 | return(-ENOMEM); | |
682 | } | |
683 | err = link_file(to_name, from_name); | |
684 | kfree(from_name); | |
685 | kfree(to_name); | |
686 | return(err); | |
687 | } | |
688 | ||
689 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
690 | { | |
691 | char *file; | |
692 | int err; | |
693 | ||
694 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
695 | if(append) | |
696 | return(-EPERM); | |
697 | ||
698 | err = unlink_file(file); | |
699 | kfree(file); | |
700 | return(err); | |
701 | } | |
702 | ||
703 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
704 | { | |
705 | char *file; | |
706 | int err; | |
707 | ||
708 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
709 | err = make_symlink(file, to); | |
710 | kfree(file); | |
711 | return(err); | |
712 | } | |
713 | ||
714 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
715 | { | |
716 | char *file; | |
717 | int err; | |
718 | ||
719 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
720 | err = do_mkdir(file, mode); | |
721 | kfree(file); | |
722 | return(err); | |
723 | } | |
724 | ||
725 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
726 | { | |
727 | char *file; | |
728 | int err; | |
729 | ||
730 | if((file = inode_dentry_name(ino, dentry)) == NULL) return(-ENOMEM); | |
731 | err = do_rmdir(file); | |
732 | kfree(file); | |
733 | return(err); | |
734 | } | |
735 | ||
736 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
737 | { | |
738 | struct inode *inode; | |
739 | char *name; | |
740 | int err = -ENOMEM; | |
741 | ||
742 | inode = iget(dir->i_sb, 0); | |
743 | if(inode == NULL) | |
744 | goto out; | |
745 | ||
746 | err = init_inode(inode, dentry); | |
747 | if(err) | |
748 | goto out_put; | |
749 | ||
750 | err = -ENOMEM; | |
751 | name = dentry_name(dentry, 0); | |
752 | if(name == NULL) | |
753 | goto out_put; | |
754 | ||
755 | init_special_inode(inode, mode, dev); | |
756 | err = do_mknod(name, mode, dev); | |
757 | if(err) | |
758 | goto out_free; | |
759 | ||
760 | err = read_name(inode, name); | |
761 | kfree(name); | |
762 | if(err) | |
763 | goto out_put; | |
764 | ||
765 | d_instantiate(dentry, inode); | |
766 | return(0); | |
767 | ||
768 | out_free: | |
769 | kfree(name); | |
770 | out_put: | |
771 | iput(inode); | |
772 | out: | |
773 | return(err); | |
774 | } | |
775 | ||
776 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
777 | struct inode *to_ino, struct dentry *to) | |
778 | { | |
779 | char *from_name, *to_name; | |
780 | int err; | |
781 | ||
782 | if((from_name = inode_dentry_name(from_ino, from)) == NULL) | |
783 | return(-ENOMEM); | |
784 | if((to_name = inode_dentry_name(to_ino, to)) == NULL){ | |
785 | kfree(from_name); | |
786 | return(-ENOMEM); | |
787 | } | |
788 | err = rename_file(from_name, to_name); | |
789 | kfree(from_name); | |
790 | kfree(to_name); | |
791 | return(err); | |
792 | } | |
793 | ||
1da177e4 LT |
794 | int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) |
795 | { | |
796 | char *name; | |
797 | int r = 0, w = 0, x = 0, err; | |
798 | ||
799 | if (desired & MAY_READ) r = 1; | |
800 | if (desired & MAY_WRITE) w = 1; | |
801 | if (desired & MAY_EXEC) x = 1; | |
802 | name = inode_name(ino, 0); | |
803 | if (name == NULL) return(-ENOMEM); | |
804 | ||
805 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
806 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) | |
807 | err = 0; | |
808 | else | |
809 | err = access_file(name, r, w, x); | |
810 | kfree(name); | |
811 | if(!err) | |
812 | err = generic_permission(ino, desired, NULL); | |
813 | return err; | |
814 | } | |
815 | ||
816 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
817 | { | |
818 | struct hostfs_iattr attrs; | |
819 | char *name; | |
820 | int err; | |
821 | ||
822 | err = inode_change_ok(dentry->d_inode, attr); | |
823 | if (err) | |
824 | return err; | |
825 | ||
826 | if(append) | |
827 | attr->ia_valid &= ~ATTR_SIZE; | |
828 | ||
829 | attrs.ia_valid = 0; | |
830 | if(attr->ia_valid & ATTR_MODE){ | |
831 | attrs.ia_valid |= HOSTFS_ATTR_MODE; | |
832 | attrs.ia_mode = attr->ia_mode; | |
833 | } | |
834 | if(attr->ia_valid & ATTR_UID){ | |
1da177e4 LT |
835 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
836 | attrs.ia_uid = attr->ia_uid; | |
837 | } | |
838 | if(attr->ia_valid & ATTR_GID){ | |
1da177e4 LT |
839 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
840 | attrs.ia_gid = attr->ia_gid; | |
841 | } | |
842 | if(attr->ia_valid & ATTR_SIZE){ | |
843 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; | |
844 | attrs.ia_size = attr->ia_size; | |
845 | } | |
846 | if(attr->ia_valid & ATTR_ATIME){ | |
847 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; | |
848 | attrs.ia_atime = attr->ia_atime; | |
849 | } | |
850 | if(attr->ia_valid & ATTR_MTIME){ | |
851 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; | |
852 | attrs.ia_mtime = attr->ia_mtime; | |
853 | } | |
854 | if(attr->ia_valid & ATTR_CTIME){ | |
855 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; | |
856 | attrs.ia_ctime = attr->ia_ctime; | |
857 | } | |
858 | if(attr->ia_valid & ATTR_ATIME_SET){ | |
859 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; | |
860 | } | |
861 | if(attr->ia_valid & ATTR_MTIME_SET){ | |
862 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; | |
863 | } | |
864 | name = dentry_name(dentry, 0); | |
865 | if(name == NULL) return(-ENOMEM); | |
866 | err = set_attr(name, &attrs); | |
867 | kfree(name); | |
868 | if(err) | |
869 | return(err); | |
870 | ||
871 | return(inode_setattr(dentry->d_inode, attr)); | |
872 | } | |
873 | ||
874 | int hostfs_getattr(struct vfsmount *mnt, struct dentry *dentry, | |
875 | struct kstat *stat) | |
876 | { | |
877 | generic_fillattr(dentry->d_inode, stat); | |
878 | return(0); | |
879 | } | |
880 | ||
881 | static struct inode_operations hostfs_iops = { | |
882 | .create = hostfs_create, | |
883 | .link = hostfs_link, | |
884 | .unlink = hostfs_unlink, | |
885 | .symlink = hostfs_symlink, | |
886 | .mkdir = hostfs_mkdir, | |
887 | .rmdir = hostfs_rmdir, | |
888 | .mknod = hostfs_mknod, | |
889 | .rename = hostfs_rename, | |
1da177e4 LT |
890 | .permission = hostfs_permission, |
891 | .setattr = hostfs_setattr, | |
892 | .getattr = hostfs_getattr, | |
893 | }; | |
894 | ||
895 | static struct inode_operations hostfs_dir_iops = { | |
896 | .create = hostfs_create, | |
897 | .lookup = hostfs_lookup, | |
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 | ||
910 | int hostfs_link_readpage(struct file *file, struct page *page) | |
911 | { | |
912 | char *buffer, *name; | |
913 | long long start; | |
914 | int err; | |
915 | ||
916 | start = page->index << PAGE_CACHE_SHIFT; | |
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 | ||
935 | static struct address_space_operations hostfs_link_aops = { | |
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 | ||
993 | static struct super_block *hostfs_read_sb(struct file_system_type *type, | |
994 | int flags, const char *dev_name, | |
995 | void *data) | |
996 | { | |
997 | return(get_sb_nodev(type, flags, data, hostfs_fill_sb_common)); | |
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 | */ |