Commit | Line | Data |
---|---|---|
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 | ||
1da177e4 | 9 | #include <linux/fs.h> |
2b3b9bb0 | 10 | #include <linux/magic.h> |
1da177e4 | 11 | #include <linux/module.h> |
84b3db04 | 12 | #include <linux/mm.h> |
1da177e4 | 13 | #include <linux/pagemap.h> |
1da177e4 | 14 | #include <linux/statfs.h> |
5a0e3ad6 | 15 | #include <linux/slab.h> |
dd2cc4df | 16 | #include <linux/seq_file.h> |
6966a977 | 17 | #include <linux/mount.h> |
d0352d3e | 18 | #include <linux/namei.h> |
1da177e4 | 19 | #include "hostfs.h" |
37185b33 AV |
20 | #include <init.h> |
21 | #include <kern.h> | |
1da177e4 LT |
22 | |
23 | struct hostfs_inode_info { | |
1da177e4 | 24 | int fd; |
aeb5d727 | 25 | fmode_t mode; |
1da177e4 | 26 | struct inode vfs_inode; |
69886e67 | 27 | struct mutex open_mutex; |
1da177e4 LT |
28 | }; |
29 | ||
30 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
31 | { | |
f1adc05e | 32 | return list_entry(inode, struct hostfs_inode_info, vfs_inode); |
1da177e4 LT |
33 | } |
34 | ||
496ad9aa | 35 | #define FILE_HOSTFS_I(file) HOSTFS_I(file_inode(file)) |
1da177e4 | 36 | |
1da177e4 | 37 | /* Changed in hostfs_args before the kernel starts running */ |
a6eb0be6 | 38 | static char *root_ino = ""; |
1da177e4 LT |
39 | static int append = 0; |
40 | ||
92e1d5be AV |
41 | static const struct inode_operations hostfs_iops; |
42 | static const struct inode_operations hostfs_dir_iops; | |
d0352d3e | 43 | static const struct inode_operations hostfs_link_iops; |
1da177e4 LT |
44 | |
45 | #ifndef MODULE | |
46 | static int __init hostfs_args(char *options, int *add) | |
47 | { | |
48 | char *ptr; | |
49 | ||
50 | ptr = strchr(options, ','); | |
84b3db04 | 51 | if (ptr != NULL) |
1da177e4 | 52 | *ptr++ = '\0'; |
84b3db04 | 53 | if (*options != '\0') |
1da177e4 LT |
54 | root_ino = options; |
55 | ||
56 | options = ptr; | |
84b3db04 | 57 | while (options) { |
1da177e4 | 58 | ptr = strchr(options, ','); |
84b3db04 | 59 | if (ptr != NULL) |
1da177e4 | 60 | *ptr++ = '\0'; |
84b3db04 JD |
61 | if (*options != '\0') { |
62 | if (!strcmp(options, "append")) | |
1da177e4 LT |
63 | append = 1; |
64 | else printf("hostfs_args - unsupported option - %s\n", | |
65 | options); | |
66 | } | |
67 | options = ptr; | |
68 | } | |
f1adc05e | 69 | return 0; |
1da177e4 LT |
70 | } |
71 | ||
72 | __uml_setup("hostfs=", hostfs_args, | |
73 | "hostfs=<root dir>,<flags>,...\n" | |
74 | " This is used to set hostfs parameters. The root directory argument\n" | |
75 | " is used to confine all hostfs mounts to within the specified directory\n" | |
76 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
77 | " mount anything on the host that's accessible to the user that's running\n" | |
78 | " it.\n" | |
79 | " The only flag currently supported is 'append', which specifies that all\n" | |
80 | " files opened by hostfs will be opened in append mode.\n\n" | |
81 | ); | |
82 | #endif | |
83 | ||
e9193059 | 84 | static char *__dentry_name(struct dentry *dentry, char *name) |
1da177e4 | 85 | { |
ec2447c2 | 86 | char *p = dentry_path_raw(dentry, name, PATH_MAX); |
e9193059 AV |
87 | char *root; |
88 | size_t len; | |
1da177e4 | 89 | |
e9193059 AV |
90 | root = dentry->d_sb->s_fs_info; |
91 | len = strlen(root); | |
92 | if (IS_ERR(p)) { | |
93 | __putname(name); | |
f1adc05e | 94 | return NULL; |
1da177e4 | 95 | } |
850a496f | 96 | strlcpy(name, root, PATH_MAX); |
e9193059 AV |
97 | if (len > p - name) { |
98 | __putname(name); | |
99 | return NULL; | |
100 | } | |
101 | if (p > name + len) { | |
102 | char *s = name + len; | |
103 | while ((*s++ = *p++) != '\0') | |
104 | ; | |
105 | } | |
f1adc05e | 106 | return name; |
1da177e4 LT |
107 | } |
108 | ||
e9193059 AV |
109 | static char *dentry_name(struct dentry *dentry) |
110 | { | |
111 | char *name = __getname(); | |
112 | if (!name) | |
113 | return NULL; | |
114 | ||
9dcc5e8a | 115 | return __dentry_name(dentry, name); |
e9193059 AV |
116 | } |
117 | ||
c5322220 | 118 | static char *inode_name(struct inode *ino) |
1da177e4 LT |
119 | { |
120 | struct dentry *dentry; | |
ec2447c2 | 121 | char *name; |
1da177e4 | 122 | |
ec2447c2 NP |
123 | dentry = d_find_alias(ino); |
124 | if (!dentry) | |
e9193059 | 125 | return NULL; |
ec2447c2 NP |
126 | |
127 | name = dentry_name(dentry); | |
128 | ||
129 | dput(dentry); | |
130 | ||
131 | return name; | |
1da177e4 LT |
132 | } |
133 | ||
1da177e4 LT |
134 | static char *follow_link(char *link) |
135 | { | |
136 | int len, n; | |
137 | char *name, *resolved, *end; | |
138 | ||
139 | len = 64; | |
84b3db04 | 140 | while (1) { |
1da177e4 LT |
141 | n = -ENOMEM; |
142 | name = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 143 | if (name == NULL) |
1da177e4 LT |
144 | goto out; |
145 | ||
ea7e743e | 146 | n = hostfs_do_readlink(link, name, len); |
84b3db04 | 147 | if (n < len) |
1da177e4 LT |
148 | break; |
149 | len *= 2; | |
150 | kfree(name); | |
151 | } | |
84b3db04 | 152 | if (n < 0) |
1da177e4 LT |
153 | goto out_free; |
154 | ||
84b3db04 | 155 | if (*name == '/') |
f1adc05e | 156 | return name; |
1da177e4 LT |
157 | |
158 | end = strrchr(link, '/'); | |
84b3db04 | 159 | if (end == NULL) |
f1adc05e | 160 | return name; |
1da177e4 LT |
161 | |
162 | *(end + 1) = '\0'; | |
163 | len = strlen(link) + strlen(name) + 1; | |
164 | ||
165 | resolved = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 166 | if (resolved == NULL) { |
1da177e4 LT |
167 | n = -ENOMEM; |
168 | goto out_free; | |
169 | } | |
170 | ||
171 | sprintf(resolved, "%s%s", link, name); | |
172 | kfree(name); | |
173 | kfree(link); | |
f1adc05e | 174 | return resolved; |
1da177e4 LT |
175 | |
176 | out_free: | |
177 | kfree(name); | |
178 | out: | |
f1adc05e | 179 | return ERR_PTR(n); |
1da177e4 LT |
180 | } |
181 | ||
0a370e5d DH |
182 | static struct inode *hostfs_iget(struct super_block *sb) |
183 | { | |
52b209f7 | 184 | struct inode *inode = new_inode(sb); |
0a370e5d DH |
185 | if (!inode) |
186 | return ERR_PTR(-ENOMEM); | |
0a370e5d DH |
187 | return inode; |
188 | } | |
189 | ||
9e443bc3 | 190 | static int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 | 191 | { |
84b3db04 JD |
192 | /* |
193 | * do_statfs uses struct statfs64 internally, but the linux kernel | |
1da177e4 LT |
194 | * struct statfs still has 32-bit versions for most of these fields, |
195 | * so we convert them here | |
196 | */ | |
197 | int err; | |
198 | long long f_blocks; | |
199 | long long f_bfree; | |
200 | long long f_bavail; | |
201 | long long f_files; | |
202 | long long f_ffree; | |
203 | ||
601d2c38 | 204 | err = do_statfs(dentry->d_sb->s_fs_info, |
1da177e4 LT |
205 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
206 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
1b627d57 | 207 | &sf->f_namelen); |
84b3db04 | 208 | if (err) |
f1adc05e | 209 | return err; |
1da177e4 LT |
210 | sf->f_blocks = f_blocks; |
211 | sf->f_bfree = f_bfree; | |
212 | sf->f_bavail = f_bavail; | |
213 | sf->f_files = f_files; | |
214 | sf->f_ffree = f_ffree; | |
215 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
f1adc05e | 216 | return 0; |
1da177e4 LT |
217 | } |
218 | ||
219 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
220 | { | |
221 | struct hostfs_inode_info *hi; | |
222 | ||
371fdab1 | 223 | hi = kmalloc(sizeof(*hi), GFP_KERNEL); |
84b3db04 | 224 | if (hi == NULL) |
f1adc05e | 225 | return NULL; |
601d2c38 | 226 | hi->fd = -1; |
371fdab1 | 227 | hi->mode = 0; |
1da177e4 | 228 | inode_init_once(&hi->vfs_inode); |
69886e67 | 229 | mutex_init(&hi->open_mutex); |
f1adc05e | 230 | return &hi->vfs_inode; |
1da177e4 LT |
231 | } |
232 | ||
e971a6d7 | 233 | static void hostfs_evict_inode(struct inode *inode) |
1da177e4 | 234 | { |
91b0abe3 | 235 | truncate_inode_pages_final(&inode->i_data); |
dbd5768f | 236 | clear_inode(inode); |
84b3db04 | 237 | if (HOSTFS_I(inode)->fd != -1) { |
1da177e4 LT |
238 | close_file(&HOSTFS_I(inode)->fd); |
239 | HOSTFS_I(inode)->fd = -1; | |
240 | } | |
1da177e4 LT |
241 | } |
242 | ||
fa0d7e3d | 243 | static void hostfs_i_callback(struct rcu_head *head) |
1da177e4 | 244 | { |
fa0d7e3d | 245 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
246 | kfree(HOSTFS_I(inode)); |
247 | } | |
fa0d7e3d NP |
248 | |
249 | static void hostfs_destroy_inode(struct inode *inode) | |
250 | { | |
251 | call_rcu(&inode->i_rcu, hostfs_i_callback); | |
252 | } | |
1da177e4 | 253 | |
34c80b1d | 254 | static int hostfs_show_options(struct seq_file *seq, struct dentry *root) |
dd2cc4df | 255 | { |
34c80b1d | 256 | const char *root_path = root->d_sb->s_fs_info; |
dd2cc4df MS |
257 | size_t offset = strlen(root_ino) + 1; |
258 | ||
259 | if (strlen(root_path) > offset) | |
260 | seq_printf(seq, ",%s", root_path + offset); | |
261 | ||
262 | return 0; | |
263 | } | |
264 | ||
ee9b6d61 | 265 | static const struct super_operations hostfs_sbops = { |
1da177e4 | 266 | .alloc_inode = hostfs_alloc_inode, |
1da177e4 | 267 | .destroy_inode = hostfs_destroy_inode, |
e971a6d7 | 268 | .evict_inode = hostfs_evict_inode, |
1da177e4 | 269 | .statfs = hostfs_statfs, |
dd2cc4df | 270 | .show_options = hostfs_show_options, |
1da177e4 LT |
271 | }; |
272 | ||
9e443bc3 | 273 | static int hostfs_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 LT |
274 | { |
275 | void *dir; | |
276 | char *name; | |
277 | unsigned long long next, ino; | |
278 | int error, len; | |
3ee6bd8e | 279 | unsigned int type; |
1da177e4 | 280 | |
c5322220 | 281 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 282 | if (name == NULL) |
f1adc05e | 283 | return -ENOMEM; |
1da177e4 | 284 | dir = open_dir(name, &error); |
e9193059 | 285 | __putname(name); |
84b3db04 | 286 | if (dir == NULL) |
f1adc05e | 287 | return -error; |
8e28bc7e | 288 | next = ctx->pos; |
3ee6bd8e | 289 | while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) { |
8e28bc7e AV |
290 | if (!dir_emit(ctx, name, len, ino, type)) |
291 | break; | |
292 | ctx->pos = next; | |
1da177e4 LT |
293 | } |
294 | close_dir(dir); | |
f1adc05e | 295 | return 0; |
1da177e4 LT |
296 | } |
297 | ||
4c6dcafc | 298 | static int hostfs_open(struct inode *ino, struct file *file) |
1da177e4 LT |
299 | { |
300 | char *name; | |
aeb5d727 | 301 | fmode_t mode = 0; |
f8ad850f | 302 | int err; |
aeb5d727 | 303 | int r = 0, w = 0, fd; |
1da177e4 LT |
304 | |
305 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 306 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 307 | return 0; |
1da177e4 | 308 | |
f8ad850f | 309 | mode |= HOSTFS_I(ino)->mode; |
1da177e4 | 310 | |
f8ad850f AV |
311 | retry: |
312 | if (mode & FMODE_READ) | |
1da177e4 | 313 | r = 1; |
f8ad850f | 314 | if (mode & FMODE_WRITE) |
1da177e4 | 315 | w = 1; |
84b3db04 | 316 | if (w) |
1da177e4 LT |
317 | r = 1; |
318 | ||
c5322220 | 319 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 320 | if (name == NULL) |
f1adc05e | 321 | return -ENOMEM; |
1da177e4 LT |
322 | |
323 | fd = open_file(name, r, w, append); | |
e9193059 | 324 | __putname(name); |
84b3db04 | 325 | if (fd < 0) |
f1adc05e | 326 | return fd; |
f8ad850f | 327 | |
69886e67 | 328 | mutex_lock(&HOSTFS_I(ino)->open_mutex); |
f8ad850f AV |
329 | /* somebody else had handled it first? */ |
330 | if ((mode & HOSTFS_I(ino)->mode) == mode) { | |
69886e67 | 331 | mutex_unlock(&HOSTFS_I(ino)->open_mutex); |
af955658 | 332 | close_file(&fd); |
f8ad850f AV |
333 | return 0; |
334 | } | |
335 | if ((mode | HOSTFS_I(ino)->mode) != mode) { | |
336 | mode |= HOSTFS_I(ino)->mode; | |
69886e67 | 337 | mutex_unlock(&HOSTFS_I(ino)->open_mutex); |
f8ad850f AV |
338 | close_file(&fd); |
339 | goto retry; | |
340 | } | |
341 | if (HOSTFS_I(ino)->fd == -1) { | |
342 | HOSTFS_I(ino)->fd = fd; | |
343 | } else { | |
344 | err = replace_file(fd, HOSTFS_I(ino)->fd); | |
345 | close_file(&fd); | |
346 | if (err < 0) { | |
69886e67 | 347 | mutex_unlock(&HOSTFS_I(ino)->open_mutex); |
f8ad850f AV |
348 | return err; |
349 | } | |
350 | } | |
351 | HOSTFS_I(ino)->mode = mode; | |
69886e67 | 352 | mutex_unlock(&HOSTFS_I(ino)->open_mutex); |
1da177e4 | 353 | |
f1adc05e | 354 | return 0; |
1da177e4 LT |
355 | } |
356 | ||
65984ff9 RW |
357 | static int hostfs_file_release(struct inode *inode, struct file *file) |
358 | { | |
359 | filemap_write_and_wait(inode->i_mapping); | |
360 | ||
361 | return 0; | |
362 | } | |
363 | ||
9e443bc3 JH |
364 | static int hostfs_fsync(struct file *file, loff_t start, loff_t end, |
365 | int datasync) | |
1da177e4 | 366 | { |
02c24a82 JB |
367 | struct inode *inode = file->f_mapping->host; |
368 | int ret; | |
369 | ||
370 | ret = filemap_write_and_wait_range(inode->i_mapping, start, end); | |
371 | if (ret) | |
372 | return ret; | |
373 | ||
374 | mutex_lock(&inode->i_mutex); | |
375 | ret = fsync_file(HOSTFS_I(inode)->fd, datasync); | |
376 | mutex_unlock(&inode->i_mutex); | |
377 | ||
378 | return ret; | |
1da177e4 LT |
379 | } |
380 | ||
4b6f5d20 | 381 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 382 | .llseek = generic_file_llseek, |
aad4f8bb | 383 | .read = new_sync_read, |
5ffc4ef4 | 384 | .splice_read = generic_file_splice_read, |
aad4f8bb | 385 | .read_iter = generic_file_read_iter, |
8174202b AV |
386 | .write_iter = generic_file_write_iter, |
387 | .write = new_sync_write, | |
1da177e4 | 388 | .mmap = generic_file_mmap, |
4c6dcafc | 389 | .open = hostfs_open, |
65984ff9 | 390 | .release = hostfs_file_release, |
1da177e4 LT |
391 | .fsync = hostfs_fsync, |
392 | }; | |
393 | ||
4b6f5d20 | 394 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 | 395 | .llseek = generic_file_llseek, |
8e28bc7e | 396 | .iterate = hostfs_readdir, |
1da177e4 | 397 | .read = generic_read_dir, |
4c6dcafc RW |
398 | .open = hostfs_open, |
399 | .fsync = hostfs_fsync, | |
1da177e4 LT |
400 | }; |
401 | ||
9e443bc3 | 402 | static int hostfs_writepage(struct page *page, struct writeback_control *wbc) |
1da177e4 LT |
403 | { |
404 | struct address_space *mapping = page->mapping; | |
405 | struct inode *inode = mapping->host; | |
406 | char *buffer; | |
407 | unsigned long long base; | |
408 | int count = PAGE_CACHE_SIZE; | |
409 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
410 | int err; | |
411 | ||
412 | if (page->index >= end_index) | |
413 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
414 | ||
415 | buffer = kmap(page); | |
416 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
417 | ||
418 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 419 | if (err != count) { |
1da177e4 LT |
420 | ClearPageUptodate(page); |
421 | goto out; | |
422 | } | |
423 | ||
424 | if (base > inode->i_size) | |
425 | inode->i_size = base; | |
426 | ||
427 | if (PageError(page)) | |
428 | ClearPageError(page); | |
429 | err = 0; | |
430 | ||
431 | out: | |
432 | kunmap(page); | |
433 | ||
434 | unlock_page(page); | |
435 | return err; | |
436 | } | |
437 | ||
9e443bc3 | 438 | static int hostfs_readpage(struct file *file, struct page *page) |
1da177e4 LT |
439 | { |
440 | char *buffer; | |
441 | long long start; | |
442 | int err = 0; | |
443 | ||
444 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
445 | buffer = kmap(page); | |
446 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
447 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
448 | if (err < 0) |
449 | goto out; | |
1da177e4 LT |
450 | |
451 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
452 | ||
453 | flush_dcache_page(page); | |
454 | SetPageUptodate(page); | |
455 | if (PageError(page)) ClearPageError(page); | |
456 | err = 0; | |
457 | out: | |
458 | kunmap(page); | |
459 | unlock_page(page); | |
f1adc05e | 460 | return err; |
1da177e4 LT |
461 | } |
462 | ||
9e443bc3 JH |
463 | static int hostfs_write_begin(struct file *file, struct address_space *mapping, |
464 | loff_t pos, unsigned len, unsigned flags, | |
465 | struct page **pagep, void **fsdata) | |
1da177e4 | 466 | { |
ae361ff4 | 467 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 468 | |
54566b2c | 469 | *pagep = grab_cache_page_write_begin(mapping, index, flags); |
ae361ff4 NP |
470 | if (!*pagep) |
471 | return -ENOMEM; | |
472 | return 0; | |
1da177e4 LT |
473 | } |
474 | ||
9e443bc3 JH |
475 | static int hostfs_write_end(struct file *file, struct address_space *mapping, |
476 | loff_t pos, unsigned len, unsigned copied, | |
477 | struct page *page, void *fsdata) | |
1da177e4 | 478 | { |
1da177e4 | 479 | struct inode *inode = mapping->host; |
ae361ff4 NP |
480 | void *buffer; |
481 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
482 | int err; | |
1da177e4 | 483 | |
1da177e4 | 484 | buffer = kmap(page); |
ae361ff4 NP |
485 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
486 | kunmap(page); | |
30f04a4e | 487 | |
ae361ff4 NP |
488 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
489 | SetPageUptodate(page); | |
30f04a4e | 490 | |
84b3db04 JD |
491 | /* |
492 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
493 | * i_size against the last byte written. |
494 | */ | |
495 | if (err > 0 && (pos > inode->i_size)) | |
496 | inode->i_size = pos; | |
497 | unlock_page(page); | |
498 | page_cache_release(page); | |
1da177e4 | 499 | |
f1adc05e | 500 | return err; |
1da177e4 LT |
501 | } |
502 | ||
f5e54d6e | 503 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
504 | .writepage = hostfs_writepage, |
505 | .readpage = hostfs_readpage, | |
ffa0aea6 | 506 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
507 | .write_begin = hostfs_write_begin, |
508 | .write_end = hostfs_write_end, | |
1da177e4 LT |
509 | }; |
510 | ||
4754b825 | 511 | static int read_name(struct inode *ino, char *name) |
1da177e4 | 512 | { |
4754b825 AV |
513 | dev_t rdev; |
514 | struct hostfs_stat st; | |
515 | int err = stat_file(name, &st, -1); | |
516 | if (err) | |
517 | return err; | |
1da177e4 | 518 | |
5e2df28c | 519 | /* Reencode maj and min with the kernel encoding.*/ |
4754b825 | 520 | rdev = MKDEV(st.maj, st.min); |
1da177e4 | 521 | |
4754b825 AV |
522 | switch (st.mode & S_IFMT) { |
523 | case S_IFLNK: | |
d0352d3e | 524 | ino->i_op = &hostfs_link_iops; |
1da177e4 | 525 | break; |
4754b825 AV |
526 | case S_IFDIR: |
527 | ino->i_op = &hostfs_dir_iops; | |
528 | ino->i_fop = &hostfs_dir_fops; | |
1da177e4 | 529 | break; |
4754b825 AV |
530 | case S_IFCHR: |
531 | case S_IFBLK: | |
532 | case S_IFIFO: | |
533 | case S_IFSOCK: | |
534 | init_special_inode(ino, st.mode & S_IFMT, rdev); | |
535 | ino->i_op = &hostfs_iops; | |
1da177e4 | 536 | break; |
4754b825 AV |
537 | |
538 | default: | |
539 | ino->i_op = &hostfs_iops; | |
540 | ino->i_fop = &hostfs_file_fops; | |
541 | ino->i_mapping->a_ops = &hostfs_aops; | |
1da177e4 | 542 | } |
4754b825 AV |
543 | |
544 | ino->i_ino = st.ino; | |
545 | ino->i_mode = st.mode; | |
bfe86848 | 546 | set_nlink(ino, st.nlink); |
29f82ae5 EB |
547 | i_uid_write(ino, st.uid); |
548 | i_gid_write(ino, st.gid); | |
4754b825 AV |
549 | ino->i_atime = st.atime; |
550 | ino->i_mtime = st.mtime; | |
551 | ino->i_ctime = st.ctime; | |
552 | ino->i_size = st.size; | |
553 | ino->i_blocks = st.blocks; | |
554 | return 0; | |
1da177e4 LT |
555 | } |
556 | ||
9e443bc3 JH |
557 | static int hostfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
558 | bool excl) | |
1da177e4 LT |
559 | { |
560 | struct inode *inode; | |
561 | char *name; | |
562 | int error, fd; | |
563 | ||
0a370e5d DH |
564 | inode = hostfs_iget(dir->i_sb); |
565 | if (IS_ERR(inode)) { | |
566 | error = PTR_ERR(inode); | |
84b3db04 | 567 | goto out; |
0a370e5d | 568 | } |
1da177e4 | 569 | |
1da177e4 | 570 | error = -ENOMEM; |
c5322220 | 571 | name = dentry_name(dentry); |
84b3db04 | 572 | if (name == NULL) |
1da177e4 LT |
573 | goto out_put; |
574 | ||
575 | fd = file_create(name, | |
576 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
577 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
578 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
4754b825 | 579 | if (fd < 0) |
1da177e4 | 580 | error = fd; |
4754b825 | 581 | else |
5e2df28c | 582 | error = read_name(inode, name); |
1da177e4 | 583 | |
e9193059 | 584 | __putname(name); |
84b3db04 | 585 | if (error) |
1da177e4 LT |
586 | goto out_put; |
587 | ||
588 | HOSTFS_I(inode)->fd = fd; | |
589 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
590 | d_instantiate(dentry, inode); | |
f1adc05e | 591 | return 0; |
1da177e4 LT |
592 | |
593 | out_put: | |
594 | iput(inode); | |
595 | out: | |
f1adc05e | 596 | return error; |
1da177e4 LT |
597 | } |
598 | ||
9e443bc3 JH |
599 | static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, |
600 | unsigned int flags) | |
1da177e4 LT |
601 | { |
602 | struct inode *inode; | |
603 | char *name; | |
604 | int err; | |
605 | ||
0a370e5d DH |
606 | inode = hostfs_iget(ino->i_sb); |
607 | if (IS_ERR(inode)) { | |
608 | err = PTR_ERR(inode); | |
1da177e4 | 609 | goto out; |
0a370e5d | 610 | } |
1da177e4 | 611 | |
1da177e4 | 612 | err = -ENOMEM; |
c5322220 | 613 | name = dentry_name(dentry); |
84b3db04 | 614 | if (name == NULL) |
1da177e4 LT |
615 | goto out_put; |
616 | ||
617 | err = read_name(inode, name); | |
5e2df28c | 618 | |
e9193059 | 619 | __putname(name); |
84b3db04 | 620 | if (err == -ENOENT) { |
1da177e4 LT |
621 | iput(inode); |
622 | inode = NULL; | |
623 | } | |
84b3db04 | 624 | else if (err) |
1da177e4 LT |
625 | goto out_put; |
626 | ||
627 | d_add(dentry, inode); | |
f1adc05e | 628 | return NULL; |
1da177e4 LT |
629 | |
630 | out_put: | |
631 | iput(inode); | |
632 | out: | |
f1adc05e | 633 | return ERR_PTR(err); |
1da177e4 LT |
634 | } |
635 | ||
9e443bc3 JH |
636 | static int hostfs_link(struct dentry *to, struct inode *ino, |
637 | struct dentry *from) | |
1da177e4 | 638 | { |
f1adc05e JD |
639 | char *from_name, *to_name; |
640 | int err; | |
1da177e4 | 641 | |
c5322220 | 642 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 643 | return -ENOMEM; |
c5322220 | 644 | to_name = dentry_name(to); |
84b3db04 | 645 | if (to_name == NULL) { |
e9193059 | 646 | __putname(from_name); |
f1adc05e | 647 | return -ENOMEM; |
1da177e4 | 648 | } |
f1adc05e | 649 | err = link_file(to_name, from_name); |
e9193059 AV |
650 | __putname(from_name); |
651 | __putname(to_name); | |
f1adc05e | 652 | return err; |
1da177e4 LT |
653 | } |
654 | ||
9e443bc3 | 655 | static int hostfs_unlink(struct inode *ino, struct dentry *dentry) |
1da177e4 LT |
656 | { |
657 | char *file; | |
658 | int err; | |
659 | ||
84b3db04 | 660 | if (append) |
f1adc05e | 661 | return -EPERM; |
1da177e4 | 662 | |
f8d7e187 AV |
663 | if ((file = dentry_name(dentry)) == NULL) |
664 | return -ENOMEM; | |
665 | ||
1da177e4 | 666 | err = unlink_file(file); |
e9193059 | 667 | __putname(file); |
f1adc05e | 668 | return err; |
1da177e4 LT |
669 | } |
670 | ||
9e443bc3 JH |
671 | static int hostfs_symlink(struct inode *ino, struct dentry *dentry, |
672 | const char *to) | |
1da177e4 LT |
673 | { |
674 | char *file; | |
675 | int err; | |
676 | ||
c5322220 | 677 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 678 | return -ENOMEM; |
1da177e4 | 679 | err = make_symlink(file, to); |
e9193059 | 680 | __putname(file); |
f1adc05e | 681 | return err; |
1da177e4 LT |
682 | } |
683 | ||
9e443bc3 | 684 | static int hostfs_mkdir(struct inode *ino, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
685 | { |
686 | char *file; | |
687 | int err; | |
688 | ||
c5322220 | 689 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 690 | return -ENOMEM; |
1da177e4 | 691 | err = do_mkdir(file, mode); |
e9193059 | 692 | __putname(file); |
f1adc05e | 693 | return err; |
1da177e4 LT |
694 | } |
695 | ||
9e443bc3 | 696 | static int hostfs_rmdir(struct inode *ino, struct dentry *dentry) |
1da177e4 LT |
697 | { |
698 | char *file; | |
699 | int err; | |
700 | ||
c5322220 | 701 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 702 | return -ENOMEM; |
1da177e4 | 703 | err = do_rmdir(file); |
e9193059 | 704 | __putname(file); |
f1adc05e | 705 | return err; |
1da177e4 LT |
706 | } |
707 | ||
1a67aafb | 708 | static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
1da177e4 LT |
709 | { |
710 | struct inode *inode; | |
711 | char *name; | |
0a370e5d | 712 | int err; |
1da177e4 | 713 | |
0a370e5d DH |
714 | inode = hostfs_iget(dir->i_sb); |
715 | if (IS_ERR(inode)) { | |
716 | err = PTR_ERR(inode); | |
1da177e4 | 717 | goto out; |
0a370e5d | 718 | } |
1da177e4 | 719 | |
1da177e4 | 720 | err = -ENOMEM; |
c5322220 | 721 | name = dentry_name(dentry); |
84b3db04 | 722 | if (name == NULL) |
1da177e4 LT |
723 | goto out_put; |
724 | ||
725 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 726 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
e9193059 | 727 | if (!err) |
1da177e4 LT |
728 | goto out_free; |
729 | ||
730 | err = read_name(inode, name); | |
e9193059 | 731 | __putname(name); |
5e2df28c AV |
732 | if (err) |
733 | goto out_put; | |
84b3db04 | 734 | if (err) |
1da177e4 LT |
735 | goto out_put; |
736 | ||
737 | d_instantiate(dentry, inode); | |
f1adc05e | 738 | return 0; |
1da177e4 LT |
739 | |
740 | out_free: | |
e9193059 | 741 | __putname(name); |
1da177e4 LT |
742 | out_put: |
743 | iput(inode); | |
744 | out: | |
f1adc05e | 745 | return err; |
1da177e4 LT |
746 | } |
747 | ||
9a423bb6 MS |
748 | static int hostfs_rename2(struct inode *old_dir, struct dentry *old_dentry, |
749 | struct inode *new_dir, struct dentry *new_dentry, | |
750 | unsigned int flags) | |
1da177e4 | 751 | { |
9a423bb6 | 752 | char *old_name, *new_name; |
1da177e4 LT |
753 | int err; |
754 | ||
9a423bb6 MS |
755 | if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) |
756 | return -EINVAL; | |
757 | ||
758 | old_name = dentry_name(old_dentry); | |
759 | if (old_name == NULL) | |
f1adc05e | 760 | return -ENOMEM; |
9a423bb6 MS |
761 | new_name = dentry_name(new_dentry); |
762 | if (new_name == NULL) { | |
763 | __putname(old_name); | |
f1adc05e | 764 | return -ENOMEM; |
1da177e4 | 765 | } |
9a423bb6 MS |
766 | if (!flags) |
767 | err = rename_file(old_name, new_name); | |
768 | else | |
769 | err = rename2_file(old_name, new_name, flags); | |
770 | ||
771 | __putname(old_name); | |
772 | __putname(new_name); | |
f1adc05e | 773 | return err; |
1da177e4 LT |
774 | } |
775 | ||
9e443bc3 | 776 | static int hostfs_permission(struct inode *ino, int desired) |
1da177e4 LT |
777 | { |
778 | char *name; | |
779 | int r = 0, w = 0, x = 0, err; | |
780 | ||
10556cb2 | 781 | if (desired & MAY_NOT_BLOCK) |
b74c79e9 NP |
782 | return -ECHILD; |
783 | ||
1da177e4 LT |
784 | if (desired & MAY_READ) r = 1; |
785 | if (desired & MAY_WRITE) w = 1; | |
786 | if (desired & MAY_EXEC) x = 1; | |
c5322220 | 787 | name = inode_name(ino); |
f1adc05e JD |
788 | if (name == NULL) |
789 | return -ENOMEM; | |
1da177e4 LT |
790 | |
791 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 792 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
793 | err = 0; |
794 | else | |
795 | err = access_file(name, r, w, x); | |
e9193059 | 796 | __putname(name); |
84b3db04 | 797 | if (!err) |
2830ba7f | 798 | err = generic_permission(ino, desired); |
1da177e4 LT |
799 | return err; |
800 | } | |
801 | ||
9e443bc3 | 802 | static int hostfs_setattr(struct dentry *dentry, struct iattr *attr) |
1da177e4 | 803 | { |
1025774c | 804 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
805 | struct hostfs_iattr attrs; |
806 | char *name; | |
807 | int err; | |
808 | ||
1025774c | 809 | int fd = HOSTFS_I(inode)->fd; |
5822b7fa | 810 | |
1025774c | 811 | err = inode_change_ok(inode, attr); |
1da177e4 LT |
812 | if (err) |
813 | return err; | |
814 | ||
84b3db04 | 815 | if (append) |
1da177e4 LT |
816 | attr->ia_valid &= ~ATTR_SIZE; |
817 | ||
818 | attrs.ia_valid = 0; | |
84b3db04 | 819 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
820 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
821 | attrs.ia_mode = attr->ia_mode; | |
822 | } | |
84b3db04 | 823 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 | 824 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
29f82ae5 | 825 | attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid); |
1da177e4 | 826 | } |
84b3db04 | 827 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 | 828 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
29f82ae5 | 829 | attrs.ia_gid = from_kgid(&init_user_ns, attr->ia_gid); |
1da177e4 | 830 | } |
84b3db04 | 831 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
832 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
833 | attrs.ia_size = attr->ia_size; | |
834 | } | |
84b3db04 | 835 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
836 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
837 | attrs.ia_atime = attr->ia_atime; | |
838 | } | |
84b3db04 | 839 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
840 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
841 | attrs.ia_mtime = attr->ia_mtime; | |
842 | } | |
84b3db04 | 843 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
844 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
845 | attrs.ia_ctime = attr->ia_ctime; | |
846 | } | |
84b3db04 | 847 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
848 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
849 | } | |
84b3db04 | 850 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
851 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
852 | } | |
c5322220 | 853 | name = dentry_name(dentry); |
84b3db04 | 854 | if (name == NULL) |
f1adc05e | 855 | return -ENOMEM; |
5822b7fa | 856 | err = set_attr(name, &attrs, fd); |
e9193059 | 857 | __putname(name); |
84b3db04 | 858 | if (err) |
f1adc05e | 859 | return err; |
1da177e4 | 860 | |
1025774c | 861 | if ((attr->ia_valid & ATTR_SIZE) && |
bc077320 | 862 | attr->ia_size != i_size_read(inode)) |
3be2be0a | 863 | truncate_setsize(inode, attr->ia_size); |
1025774c CH |
864 | |
865 | setattr_copy(inode, attr); | |
866 | mark_inode_dirty(inode); | |
867 | return 0; | |
1da177e4 LT |
868 | } |
869 | ||
92e1d5be | 870 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
871 | .permission = hostfs_permission, |
872 | .setattr = hostfs_setattr, | |
1da177e4 LT |
873 | }; |
874 | ||
92e1d5be | 875 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
876 | .create = hostfs_create, |
877 | .lookup = hostfs_lookup, | |
878 | .link = hostfs_link, | |
879 | .unlink = hostfs_unlink, | |
880 | .symlink = hostfs_symlink, | |
881 | .mkdir = hostfs_mkdir, | |
882 | .rmdir = hostfs_rmdir, | |
883 | .mknod = hostfs_mknod, | |
9a423bb6 | 884 | .rename2 = hostfs_rename2, |
1da177e4 LT |
885 | .permission = hostfs_permission, |
886 | .setattr = hostfs_setattr, | |
1da177e4 LT |
887 | }; |
888 | ||
d0352d3e AV |
889 | static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
890 | { | |
891 | char *link = __getname(); | |
892 | if (link) { | |
893 | char *path = dentry_name(dentry); | |
894 | int err = -ENOMEM; | |
895 | if (path) { | |
3b6036d1 | 896 | err = hostfs_do_readlink(path, link, PATH_MAX); |
d0352d3e AV |
897 | if (err == PATH_MAX) |
898 | err = -E2BIG; | |
e9193059 | 899 | __putname(path); |
d0352d3e AV |
900 | } |
901 | if (err < 0) { | |
902 | __putname(link); | |
903 | link = ERR_PTR(err); | |
904 | } | |
905 | } else { | |
906 | link = ERR_PTR(-ENOMEM); | |
1da177e4 | 907 | } |
d0352d3e AV |
908 | |
909 | nd_set_link(nd, link); | |
910 | return NULL; | |
911 | } | |
912 | ||
913 | static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) | |
914 | { | |
915 | char *s = nd_get_link(nd); | |
916 | if (!IS_ERR(s)) | |
917 | __putname(s); | |
1da177e4 LT |
918 | } |
919 | ||
d0352d3e AV |
920 | static const struct inode_operations hostfs_link_iops = { |
921 | .readlink = generic_readlink, | |
922 | .follow_link = hostfs_follow_link, | |
923 | .put_link = hostfs_put_link, | |
1da177e4 LT |
924 | }; |
925 | ||
926 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
927 | { | |
928 | struct inode *root_inode; | |
75e8defb | 929 | char *host_root_path, *req_root = d; |
1da177e4 LT |
930 | int err; |
931 | ||
932 | sb->s_blocksize = 1024; | |
933 | sb->s_blocksize_bits = 10; | |
934 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
935 | sb->s_op = &hostfs_sbops; | |
b26d4cd3 | 936 | sb->s_d_op = &simple_dentry_operations; |
752fa51e | 937 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
1da177e4 | 938 | |
a6eb0be6 | 939 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
940 | if (req_root == NULL) |
941 | req_root = ""; | |
1da177e4 LT |
942 | |
943 | err = -ENOMEM; | |
601d2c38 AV |
944 | sb->s_fs_info = host_root_path = |
945 | kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); | |
84b3db04 | 946 | if (host_root_path == NULL) |
1da177e4 LT |
947 | goto out; |
948 | ||
75e8defb | 949 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 | 950 | |
52b209f7 AV |
951 | root_inode = new_inode(sb); |
952 | if (!root_inode) | |
601d2c38 | 953 | goto out; |
1da177e4 | 954 | |
4754b825 AV |
955 | err = read_name(root_inode, host_root_path); |
956 | if (err) | |
957 | goto out_put; | |
52b209f7 | 958 | |
4754b825 | 959 | if (S_ISLNK(root_inode->i_mode)) { |
52b209f7 AV |
960 | char *name = follow_link(host_root_path); |
961 | if (IS_ERR(name)) | |
962 | err = PTR_ERR(name); | |
963 | else | |
964 | err = read_name(root_inode, name); | |
965 | kfree(name); | |
4754b825 AV |
966 | if (err) |
967 | goto out_put; | |
52b209f7 | 968 | } |
1da177e4 | 969 | |
1da177e4 | 970 | err = -ENOMEM; |
48fde701 | 971 | sb->s_root = d_make_root(root_inode); |
84b3db04 | 972 | if (sb->s_root == NULL) |
48fde701 | 973 | goto out; |
1da177e4 | 974 | |
f1adc05e | 975 | return 0; |
1da177e4 | 976 | |
f1adc05e JD |
977 | out_put: |
978 | iput(root_inode); | |
f1adc05e JD |
979 | out: |
980 | return err; | |
1da177e4 LT |
981 | } |
982 | ||
3c26ff6e | 983 | static struct dentry *hostfs_read_sb(struct file_system_type *type, |
454e2398 | 984 | int flags, const char *dev_name, |
3c26ff6e | 985 | void *data) |
1da177e4 | 986 | { |
3c26ff6e | 987 | return mount_nodev(type, flags, data, hostfs_fill_sb_common); |
1da177e4 LT |
988 | } |
989 | ||
601d2c38 AV |
990 | static void hostfs_kill_sb(struct super_block *s) |
991 | { | |
992 | kill_anon_super(s); | |
993 | kfree(s->s_fs_info); | |
994 | } | |
995 | ||
1da177e4 LT |
996 | static struct file_system_type hostfs_type = { |
997 | .owner = THIS_MODULE, | |
998 | .name = "hostfs", | |
3c26ff6e | 999 | .mount = hostfs_read_sb, |
601d2c38 | 1000 | .kill_sb = hostfs_kill_sb, |
1da177e4 LT |
1001 | .fs_flags = 0, |
1002 | }; | |
3e64fe5b | 1003 | MODULE_ALIAS_FS("hostfs"); |
1da177e4 LT |
1004 | |
1005 | static int __init init_hostfs(void) | |
1006 | { | |
f1adc05e | 1007 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
1008 | } |
1009 | ||
1010 | static void __exit exit_hostfs(void) | |
1011 | { | |
1012 | unregister_filesystem(&hostfs_type); | |
1013 | } | |
1014 | ||
1015 | module_init(init_hostfs) | |
1016 | module_exit(exit_hostfs) | |
1017 | MODULE_LICENSE("GPL"); |