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 LT |
26 | struct inode vfs_inode; |
27 | }; | |
28 | ||
29 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
30 | { | |
f1adc05e | 31 | return list_entry(inode, struct hostfs_inode_info, vfs_inode); |
1da177e4 LT |
32 | } |
33 | ||
496ad9aa | 34 | #define FILE_HOSTFS_I(file) HOSTFS_I(file_inode(file)) |
1da177e4 | 35 | |
fe15ce44 | 36 | static int hostfs_d_delete(const struct dentry *dentry) |
1da177e4 | 37 | { |
f1adc05e | 38 | return 1; |
1da177e4 LT |
39 | } |
40 | ||
e16404ed | 41 | static const struct dentry_operations hostfs_dentry_ops = { |
1da177e4 LT |
42 | .d_delete = hostfs_d_delete, |
43 | }; | |
44 | ||
45 | /* Changed in hostfs_args before the kernel starts running */ | |
a6eb0be6 | 46 | static char *root_ino = ""; |
1da177e4 LT |
47 | static int append = 0; |
48 | ||
92e1d5be AV |
49 | static const struct inode_operations hostfs_iops; |
50 | static const struct inode_operations hostfs_dir_iops; | |
d0352d3e | 51 | static const struct inode_operations hostfs_link_iops; |
1da177e4 LT |
52 | |
53 | #ifndef MODULE | |
54 | static int __init hostfs_args(char *options, int *add) | |
55 | { | |
56 | char *ptr; | |
57 | ||
58 | ptr = strchr(options, ','); | |
84b3db04 | 59 | if (ptr != NULL) |
1da177e4 | 60 | *ptr++ = '\0'; |
84b3db04 | 61 | if (*options != '\0') |
1da177e4 LT |
62 | root_ino = options; |
63 | ||
64 | options = ptr; | |
84b3db04 | 65 | while (options) { |
1da177e4 | 66 | ptr = strchr(options, ','); |
84b3db04 | 67 | if (ptr != NULL) |
1da177e4 | 68 | *ptr++ = '\0'; |
84b3db04 JD |
69 | if (*options != '\0') { |
70 | if (!strcmp(options, "append")) | |
1da177e4 LT |
71 | append = 1; |
72 | else printf("hostfs_args - unsupported option - %s\n", | |
73 | options); | |
74 | } | |
75 | options = ptr; | |
76 | } | |
f1adc05e | 77 | return 0; |
1da177e4 LT |
78 | } |
79 | ||
80 | __uml_setup("hostfs=", hostfs_args, | |
81 | "hostfs=<root dir>,<flags>,...\n" | |
82 | " This is used to set hostfs parameters. The root directory argument\n" | |
83 | " is used to confine all hostfs mounts to within the specified directory\n" | |
84 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
85 | " mount anything on the host that's accessible to the user that's running\n" | |
86 | " it.\n" | |
87 | " The only flag currently supported is 'append', which specifies that all\n" | |
88 | " files opened by hostfs will be opened in append mode.\n\n" | |
89 | ); | |
90 | #endif | |
91 | ||
e9193059 | 92 | static char *__dentry_name(struct dentry *dentry, char *name) |
1da177e4 | 93 | { |
ec2447c2 | 94 | char *p = dentry_path_raw(dentry, name, PATH_MAX); |
e9193059 AV |
95 | char *root; |
96 | size_t len; | |
1da177e4 | 97 | |
e9193059 AV |
98 | root = dentry->d_sb->s_fs_info; |
99 | len = strlen(root); | |
100 | if (IS_ERR(p)) { | |
101 | __putname(name); | |
f1adc05e | 102 | return NULL; |
1da177e4 | 103 | } |
850a496f | 104 | strlcpy(name, root, PATH_MAX); |
e9193059 AV |
105 | if (len > p - name) { |
106 | __putname(name); | |
107 | return NULL; | |
108 | } | |
109 | if (p > name + len) { | |
110 | char *s = name + len; | |
111 | while ((*s++ = *p++) != '\0') | |
112 | ; | |
113 | } | |
f1adc05e | 114 | return name; |
1da177e4 LT |
115 | } |
116 | ||
e9193059 AV |
117 | static char *dentry_name(struct dentry *dentry) |
118 | { | |
119 | char *name = __getname(); | |
120 | if (!name) | |
121 | return NULL; | |
122 | ||
9dcc5e8a | 123 | return __dentry_name(dentry, name); |
e9193059 AV |
124 | } |
125 | ||
c5322220 | 126 | static char *inode_name(struct inode *ino) |
1da177e4 LT |
127 | { |
128 | struct dentry *dentry; | |
ec2447c2 | 129 | char *name; |
1da177e4 | 130 | |
ec2447c2 NP |
131 | dentry = d_find_alias(ino); |
132 | if (!dentry) | |
e9193059 | 133 | return NULL; |
ec2447c2 NP |
134 | |
135 | name = dentry_name(dentry); | |
136 | ||
137 | dput(dentry); | |
138 | ||
139 | return name; | |
1da177e4 LT |
140 | } |
141 | ||
1da177e4 LT |
142 | static char *follow_link(char *link) |
143 | { | |
144 | int len, n; | |
145 | char *name, *resolved, *end; | |
146 | ||
147 | len = 64; | |
84b3db04 | 148 | while (1) { |
1da177e4 LT |
149 | n = -ENOMEM; |
150 | name = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 151 | if (name == NULL) |
1da177e4 LT |
152 | goto out; |
153 | ||
ea7e743e | 154 | n = hostfs_do_readlink(link, name, len); |
84b3db04 | 155 | if (n < len) |
1da177e4 LT |
156 | break; |
157 | len *= 2; | |
158 | kfree(name); | |
159 | } | |
84b3db04 | 160 | if (n < 0) |
1da177e4 LT |
161 | goto out_free; |
162 | ||
84b3db04 | 163 | if (*name == '/') |
f1adc05e | 164 | return name; |
1da177e4 LT |
165 | |
166 | end = strrchr(link, '/'); | |
84b3db04 | 167 | if (end == NULL) |
f1adc05e | 168 | return name; |
1da177e4 LT |
169 | |
170 | *(end + 1) = '\0'; | |
171 | len = strlen(link) + strlen(name) + 1; | |
172 | ||
173 | resolved = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 174 | if (resolved == NULL) { |
1da177e4 LT |
175 | n = -ENOMEM; |
176 | goto out_free; | |
177 | } | |
178 | ||
179 | sprintf(resolved, "%s%s", link, name); | |
180 | kfree(name); | |
181 | kfree(link); | |
f1adc05e | 182 | return resolved; |
1da177e4 LT |
183 | |
184 | out_free: | |
185 | kfree(name); | |
186 | out: | |
f1adc05e | 187 | return ERR_PTR(n); |
1da177e4 LT |
188 | } |
189 | ||
0a370e5d DH |
190 | static struct inode *hostfs_iget(struct super_block *sb) |
191 | { | |
52b209f7 | 192 | struct inode *inode = new_inode(sb); |
0a370e5d DH |
193 | if (!inode) |
194 | return ERR_PTR(-ENOMEM); | |
0a370e5d DH |
195 | return inode; |
196 | } | |
197 | ||
726c3342 | 198 | int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 | 199 | { |
84b3db04 JD |
200 | /* |
201 | * do_statfs uses struct statfs64 internally, but the linux kernel | |
1da177e4 LT |
202 | * struct statfs still has 32-bit versions for most of these fields, |
203 | * so we convert them here | |
204 | */ | |
205 | int err; | |
206 | long long f_blocks; | |
207 | long long f_bfree; | |
208 | long long f_bavail; | |
209 | long long f_files; | |
210 | long long f_ffree; | |
211 | ||
601d2c38 | 212 | err = do_statfs(dentry->d_sb->s_fs_info, |
1da177e4 LT |
213 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
214 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
1b627d57 | 215 | &sf->f_namelen); |
84b3db04 | 216 | if (err) |
f1adc05e | 217 | return err; |
1da177e4 LT |
218 | sf->f_blocks = f_blocks; |
219 | sf->f_bfree = f_bfree; | |
220 | sf->f_bavail = f_bavail; | |
221 | sf->f_files = f_files; | |
222 | sf->f_ffree = f_ffree; | |
223 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
f1adc05e | 224 | return 0; |
1da177e4 LT |
225 | } |
226 | ||
227 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
228 | { | |
229 | struct hostfs_inode_info *hi; | |
230 | ||
371fdab1 | 231 | hi = kmalloc(sizeof(*hi), GFP_KERNEL); |
84b3db04 | 232 | if (hi == NULL) |
f1adc05e | 233 | return NULL; |
601d2c38 | 234 | hi->fd = -1; |
371fdab1 | 235 | hi->mode = 0; |
1da177e4 | 236 | inode_init_once(&hi->vfs_inode); |
f1adc05e | 237 | return &hi->vfs_inode; |
1da177e4 LT |
238 | } |
239 | ||
e971a6d7 | 240 | static void hostfs_evict_inode(struct inode *inode) |
1da177e4 | 241 | { |
fef26658 | 242 | truncate_inode_pages(&inode->i_data, 0); |
dbd5768f | 243 | clear_inode(inode); |
84b3db04 | 244 | if (HOSTFS_I(inode)->fd != -1) { |
1da177e4 LT |
245 | close_file(&HOSTFS_I(inode)->fd); |
246 | HOSTFS_I(inode)->fd = -1; | |
247 | } | |
1da177e4 LT |
248 | } |
249 | ||
fa0d7e3d | 250 | static void hostfs_i_callback(struct rcu_head *head) |
1da177e4 | 251 | { |
fa0d7e3d | 252 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
253 | kfree(HOSTFS_I(inode)); |
254 | } | |
fa0d7e3d NP |
255 | |
256 | static void hostfs_destroy_inode(struct inode *inode) | |
257 | { | |
258 | call_rcu(&inode->i_rcu, hostfs_i_callback); | |
259 | } | |
1da177e4 | 260 | |
34c80b1d | 261 | static int hostfs_show_options(struct seq_file *seq, struct dentry *root) |
dd2cc4df | 262 | { |
34c80b1d | 263 | const char *root_path = root->d_sb->s_fs_info; |
dd2cc4df MS |
264 | size_t offset = strlen(root_ino) + 1; |
265 | ||
266 | if (strlen(root_path) > offset) | |
267 | seq_printf(seq, ",%s", root_path + offset); | |
268 | ||
269 | return 0; | |
270 | } | |
271 | ||
ee9b6d61 | 272 | static const struct super_operations hostfs_sbops = { |
1da177e4 | 273 | .alloc_inode = hostfs_alloc_inode, |
1da177e4 | 274 | .destroy_inode = hostfs_destroy_inode, |
e971a6d7 | 275 | .evict_inode = hostfs_evict_inode, |
1da177e4 | 276 | .statfs = hostfs_statfs, |
dd2cc4df | 277 | .show_options = hostfs_show_options, |
1da177e4 LT |
278 | }; |
279 | ||
8e28bc7e | 280 | int hostfs_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 LT |
281 | { |
282 | void *dir; | |
283 | char *name; | |
284 | unsigned long long next, ino; | |
285 | int error, len; | |
3ee6bd8e | 286 | unsigned int type; |
1da177e4 | 287 | |
c5322220 | 288 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 289 | if (name == NULL) |
f1adc05e | 290 | return -ENOMEM; |
1da177e4 | 291 | dir = open_dir(name, &error); |
e9193059 | 292 | __putname(name); |
84b3db04 | 293 | if (dir == NULL) |
f1adc05e | 294 | return -error; |
8e28bc7e | 295 | next = ctx->pos; |
3ee6bd8e | 296 | while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) { |
8e28bc7e AV |
297 | if (!dir_emit(ctx, name, len, ino, type)) |
298 | break; | |
299 | ctx->pos = next; | |
1da177e4 LT |
300 | } |
301 | close_dir(dir); | |
f1adc05e | 302 | return 0; |
1da177e4 LT |
303 | } |
304 | ||
305 | int hostfs_file_open(struct inode *ino, struct file *file) | |
306 | { | |
f8ad850f | 307 | static DEFINE_MUTEX(open_mutex); |
1da177e4 | 308 | char *name; |
aeb5d727 | 309 | fmode_t mode = 0; |
f8ad850f | 310 | int err; |
aeb5d727 | 311 | int r = 0, w = 0, fd; |
1da177e4 LT |
312 | |
313 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 314 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 315 | return 0; |
1da177e4 | 316 | |
f8ad850f | 317 | mode |= HOSTFS_I(ino)->mode; |
1da177e4 | 318 | |
f8ad850f AV |
319 | retry: |
320 | if (mode & FMODE_READ) | |
1da177e4 | 321 | r = 1; |
f8ad850f | 322 | if (mode & FMODE_WRITE) |
1da177e4 | 323 | w = 1; |
84b3db04 | 324 | if (w) |
1da177e4 LT |
325 | r = 1; |
326 | ||
c5322220 | 327 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 328 | if (name == NULL) |
f1adc05e | 329 | return -ENOMEM; |
1da177e4 LT |
330 | |
331 | fd = open_file(name, r, w, append); | |
e9193059 | 332 | __putname(name); |
84b3db04 | 333 | if (fd < 0) |
f1adc05e | 334 | return fd; |
f8ad850f AV |
335 | |
336 | mutex_lock(&open_mutex); | |
337 | /* somebody else had handled it first? */ | |
338 | if ((mode & HOSTFS_I(ino)->mode) == mode) { | |
339 | mutex_unlock(&open_mutex); | |
340 | return 0; | |
341 | } | |
342 | if ((mode | HOSTFS_I(ino)->mode) != mode) { | |
343 | mode |= HOSTFS_I(ino)->mode; | |
344 | mutex_unlock(&open_mutex); | |
345 | close_file(&fd); | |
346 | goto retry; | |
347 | } | |
348 | if (HOSTFS_I(ino)->fd == -1) { | |
349 | HOSTFS_I(ino)->fd = fd; | |
350 | } else { | |
351 | err = replace_file(fd, HOSTFS_I(ino)->fd); | |
352 | close_file(&fd); | |
353 | if (err < 0) { | |
354 | mutex_unlock(&open_mutex); | |
355 | return err; | |
356 | } | |
357 | } | |
358 | HOSTFS_I(ino)->mode = mode; | |
359 | mutex_unlock(&open_mutex); | |
1da177e4 | 360 | |
f1adc05e | 361 | return 0; |
1da177e4 LT |
362 | } |
363 | ||
02c24a82 | 364 | int hostfs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
1da177e4 | 365 | { |
02c24a82 JB |
366 | struct inode *inode = file->f_mapping->host; |
367 | int ret; | |
368 | ||
369 | ret = filemap_write_and_wait_range(inode->i_mapping, start, end); | |
370 | if (ret) | |
371 | return ret; | |
372 | ||
373 | mutex_lock(&inode->i_mutex); | |
374 | ret = fsync_file(HOSTFS_I(inode)->fd, datasync); | |
375 | mutex_unlock(&inode->i_mutex); | |
376 | ||
377 | return ret; | |
1da177e4 LT |
378 | } |
379 | ||
4b6f5d20 | 380 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 381 | .llseek = generic_file_llseek, |
543ade1f | 382 | .read = do_sync_read, |
5ffc4ef4 | 383 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
384 | .aio_read = generic_file_aio_read, |
385 | .aio_write = generic_file_aio_write, | |
543ade1f | 386 | .write = do_sync_write, |
1da177e4 LT |
387 | .mmap = generic_file_mmap, |
388 | .open = hostfs_file_open, | |
389 | .release = NULL, | |
390 | .fsync = hostfs_fsync, | |
391 | }; | |
392 | ||
4b6f5d20 | 393 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 | 394 | .llseek = generic_file_llseek, |
8e28bc7e | 395 | .iterate = hostfs_readdir, |
1da177e4 LT |
396 | .read = generic_read_dir, |
397 | }; | |
398 | ||
399 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
400 | { | |
401 | struct address_space *mapping = page->mapping; | |
402 | struct inode *inode = mapping->host; | |
403 | char *buffer; | |
404 | unsigned long long base; | |
405 | int count = PAGE_CACHE_SIZE; | |
406 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
407 | int err; | |
408 | ||
409 | if (page->index >= end_index) | |
410 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
411 | ||
412 | buffer = kmap(page); | |
413 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
414 | ||
415 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 416 | if (err != count) { |
1da177e4 LT |
417 | ClearPageUptodate(page); |
418 | goto out; | |
419 | } | |
420 | ||
421 | if (base > inode->i_size) | |
422 | inode->i_size = base; | |
423 | ||
424 | if (PageError(page)) | |
425 | ClearPageError(page); | |
426 | err = 0; | |
427 | ||
428 | out: | |
429 | kunmap(page); | |
430 | ||
431 | unlock_page(page); | |
432 | return err; | |
433 | } | |
434 | ||
435 | int hostfs_readpage(struct file *file, struct page *page) | |
436 | { | |
437 | char *buffer; | |
438 | long long start; | |
439 | int err = 0; | |
440 | ||
441 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
442 | buffer = kmap(page); | |
443 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
444 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
445 | if (err < 0) |
446 | goto out; | |
1da177e4 LT |
447 | |
448 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
449 | ||
450 | flush_dcache_page(page); | |
451 | SetPageUptodate(page); | |
452 | if (PageError(page)) ClearPageError(page); | |
453 | err = 0; | |
454 | out: | |
455 | kunmap(page); | |
456 | unlock_page(page); | |
f1adc05e | 457 | return err; |
1da177e4 LT |
458 | } |
459 | ||
ae361ff4 NP |
460 | int hostfs_write_begin(struct file *file, struct address_space *mapping, |
461 | loff_t pos, unsigned len, unsigned flags, | |
462 | struct page **pagep, void **fsdata) | |
1da177e4 | 463 | { |
ae361ff4 | 464 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 465 | |
54566b2c | 466 | *pagep = grab_cache_page_write_begin(mapping, index, flags); |
ae361ff4 NP |
467 | if (!*pagep) |
468 | return -ENOMEM; | |
469 | return 0; | |
1da177e4 LT |
470 | } |
471 | ||
ae361ff4 NP |
472 | int hostfs_write_end(struct file *file, struct address_space *mapping, |
473 | loff_t pos, unsigned len, unsigned copied, | |
474 | struct page *page, void *fsdata) | |
1da177e4 | 475 | { |
1da177e4 | 476 | struct inode *inode = mapping->host; |
ae361ff4 NP |
477 | void *buffer; |
478 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
479 | int err; | |
1da177e4 | 480 | |
1da177e4 | 481 | buffer = kmap(page); |
ae361ff4 NP |
482 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
483 | kunmap(page); | |
30f04a4e | 484 | |
ae361ff4 NP |
485 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
486 | SetPageUptodate(page); | |
30f04a4e | 487 | |
84b3db04 JD |
488 | /* |
489 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
490 | * i_size against the last byte written. |
491 | */ | |
492 | if (err > 0 && (pos > inode->i_size)) | |
493 | inode->i_size = pos; | |
494 | unlock_page(page); | |
495 | page_cache_release(page); | |
1da177e4 | 496 | |
f1adc05e | 497 | return err; |
1da177e4 LT |
498 | } |
499 | ||
f5e54d6e | 500 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
501 | .writepage = hostfs_writepage, |
502 | .readpage = hostfs_readpage, | |
ffa0aea6 | 503 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
504 | .write_begin = hostfs_write_begin, |
505 | .write_end = hostfs_write_end, | |
1da177e4 LT |
506 | }; |
507 | ||
4754b825 | 508 | static int read_name(struct inode *ino, char *name) |
1da177e4 | 509 | { |
4754b825 AV |
510 | dev_t rdev; |
511 | struct hostfs_stat st; | |
512 | int err = stat_file(name, &st, -1); | |
513 | if (err) | |
514 | return err; | |
1da177e4 | 515 | |
5e2df28c | 516 | /* Reencode maj and min with the kernel encoding.*/ |
4754b825 | 517 | rdev = MKDEV(st.maj, st.min); |
1da177e4 | 518 | |
4754b825 AV |
519 | switch (st.mode & S_IFMT) { |
520 | case S_IFLNK: | |
d0352d3e | 521 | ino->i_op = &hostfs_link_iops; |
1da177e4 | 522 | break; |
4754b825 AV |
523 | case S_IFDIR: |
524 | ino->i_op = &hostfs_dir_iops; | |
525 | ino->i_fop = &hostfs_dir_fops; | |
1da177e4 | 526 | break; |
4754b825 AV |
527 | case S_IFCHR: |
528 | case S_IFBLK: | |
529 | case S_IFIFO: | |
530 | case S_IFSOCK: | |
531 | init_special_inode(ino, st.mode & S_IFMT, rdev); | |
532 | ino->i_op = &hostfs_iops; | |
1da177e4 | 533 | break; |
4754b825 AV |
534 | |
535 | default: | |
536 | ino->i_op = &hostfs_iops; | |
537 | ino->i_fop = &hostfs_file_fops; | |
538 | ino->i_mapping->a_ops = &hostfs_aops; | |
1da177e4 | 539 | } |
4754b825 AV |
540 | |
541 | ino->i_ino = st.ino; | |
542 | ino->i_mode = st.mode; | |
bfe86848 | 543 | set_nlink(ino, st.nlink); |
29f82ae5 EB |
544 | i_uid_write(ino, st.uid); |
545 | i_gid_write(ino, st.gid); | |
4754b825 AV |
546 | ino->i_atime = st.atime; |
547 | ino->i_mtime = st.mtime; | |
548 | ino->i_ctime = st.ctime; | |
549 | ino->i_size = st.size; | |
550 | ino->i_blocks = st.blocks; | |
551 | return 0; | |
1da177e4 LT |
552 | } |
553 | ||
4acdaf27 | 554 | int hostfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
ebfc3b49 | 555 | bool excl) |
1da177e4 LT |
556 | { |
557 | struct inode *inode; | |
558 | char *name; | |
559 | int error, fd; | |
560 | ||
0a370e5d DH |
561 | inode = hostfs_iget(dir->i_sb); |
562 | if (IS_ERR(inode)) { | |
563 | error = PTR_ERR(inode); | |
84b3db04 | 564 | goto out; |
0a370e5d | 565 | } |
1da177e4 | 566 | |
1da177e4 | 567 | error = -ENOMEM; |
c5322220 | 568 | name = dentry_name(dentry); |
84b3db04 | 569 | if (name == NULL) |
1da177e4 LT |
570 | goto out_put; |
571 | ||
572 | fd = file_create(name, | |
573 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
574 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
575 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
4754b825 | 576 | if (fd < 0) |
1da177e4 | 577 | error = fd; |
4754b825 | 578 | else |
5e2df28c | 579 | error = read_name(inode, name); |
1da177e4 | 580 | |
e9193059 | 581 | __putname(name); |
84b3db04 | 582 | if (error) |
1da177e4 LT |
583 | goto out_put; |
584 | ||
585 | HOSTFS_I(inode)->fd = fd; | |
586 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
587 | d_instantiate(dentry, inode); | |
f1adc05e | 588 | return 0; |
1da177e4 LT |
589 | |
590 | out_put: | |
591 | iput(inode); | |
592 | out: | |
f1adc05e | 593 | return error; |
1da177e4 LT |
594 | } |
595 | ||
596 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
00cd8dd3 | 597 | unsigned int flags) |
1da177e4 LT |
598 | { |
599 | struct inode *inode; | |
600 | char *name; | |
601 | int err; | |
602 | ||
0a370e5d DH |
603 | inode = hostfs_iget(ino->i_sb); |
604 | if (IS_ERR(inode)) { | |
605 | err = PTR_ERR(inode); | |
1da177e4 | 606 | goto out; |
0a370e5d | 607 | } |
1da177e4 | 608 | |
1da177e4 | 609 | err = -ENOMEM; |
c5322220 | 610 | name = dentry_name(dentry); |
84b3db04 | 611 | if (name == NULL) |
1da177e4 LT |
612 | goto out_put; |
613 | ||
614 | err = read_name(inode, name); | |
5e2df28c | 615 | |
e9193059 | 616 | __putname(name); |
84b3db04 | 617 | if (err == -ENOENT) { |
1da177e4 LT |
618 | iput(inode); |
619 | inode = NULL; | |
620 | } | |
84b3db04 | 621 | else if (err) |
1da177e4 LT |
622 | goto out_put; |
623 | ||
624 | d_add(dentry, inode); | |
f1adc05e | 625 | return NULL; |
1da177e4 LT |
626 | |
627 | out_put: | |
628 | iput(inode); | |
629 | out: | |
f1adc05e | 630 | return ERR_PTR(err); |
1da177e4 LT |
631 | } |
632 | ||
1da177e4 LT |
633 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) |
634 | { | |
f1adc05e JD |
635 | char *from_name, *to_name; |
636 | int err; | |
1da177e4 | 637 | |
c5322220 | 638 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 639 | return -ENOMEM; |
c5322220 | 640 | to_name = dentry_name(to); |
84b3db04 | 641 | if (to_name == NULL) { |
e9193059 | 642 | __putname(from_name); |
f1adc05e | 643 | return -ENOMEM; |
1da177e4 | 644 | } |
f1adc05e | 645 | err = link_file(to_name, from_name); |
e9193059 AV |
646 | __putname(from_name); |
647 | __putname(to_name); | |
f1adc05e | 648 | return err; |
1da177e4 LT |
649 | } |
650 | ||
651 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
652 | { | |
653 | char *file; | |
654 | int err; | |
655 | ||
84b3db04 | 656 | if (append) |
f1adc05e | 657 | return -EPERM; |
1da177e4 | 658 | |
f8d7e187 AV |
659 | if ((file = dentry_name(dentry)) == NULL) |
660 | return -ENOMEM; | |
661 | ||
1da177e4 | 662 | err = unlink_file(file); |
e9193059 | 663 | __putname(file); |
f1adc05e | 664 | return err; |
1da177e4 LT |
665 | } |
666 | ||
667 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
668 | { | |
669 | char *file; | |
670 | int err; | |
671 | ||
c5322220 | 672 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 673 | return -ENOMEM; |
1da177e4 | 674 | err = make_symlink(file, to); |
e9193059 | 675 | __putname(file); |
f1adc05e | 676 | return err; |
1da177e4 LT |
677 | } |
678 | ||
18bb1db3 | 679 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
680 | { |
681 | char *file; | |
682 | int err; | |
683 | ||
c5322220 | 684 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 685 | return -ENOMEM; |
1da177e4 | 686 | err = do_mkdir(file, mode); |
e9193059 | 687 | __putname(file); |
f1adc05e | 688 | return err; |
1da177e4 LT |
689 | } |
690 | ||
691 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
692 | { | |
693 | char *file; | |
694 | int err; | |
695 | ||
c5322220 | 696 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 697 | return -ENOMEM; |
1da177e4 | 698 | err = do_rmdir(file); |
e9193059 | 699 | __putname(file); |
f1adc05e | 700 | return err; |
1da177e4 LT |
701 | } |
702 | ||
1a67aafb | 703 | static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
1da177e4 LT |
704 | { |
705 | struct inode *inode; | |
706 | char *name; | |
0a370e5d | 707 | int err; |
1da177e4 | 708 | |
0a370e5d DH |
709 | inode = hostfs_iget(dir->i_sb); |
710 | if (IS_ERR(inode)) { | |
711 | err = PTR_ERR(inode); | |
1da177e4 | 712 | goto out; |
0a370e5d | 713 | } |
1da177e4 | 714 | |
1da177e4 | 715 | err = -ENOMEM; |
c5322220 | 716 | name = dentry_name(dentry); |
84b3db04 | 717 | if (name == NULL) |
1da177e4 LT |
718 | goto out_put; |
719 | ||
720 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 721 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
e9193059 | 722 | if (!err) |
1da177e4 LT |
723 | goto out_free; |
724 | ||
725 | err = read_name(inode, name); | |
e9193059 | 726 | __putname(name); |
5e2df28c AV |
727 | if (err) |
728 | goto out_put; | |
84b3db04 | 729 | if (err) |
1da177e4 LT |
730 | goto out_put; |
731 | ||
732 | d_instantiate(dentry, inode); | |
f1adc05e | 733 | return 0; |
1da177e4 LT |
734 | |
735 | out_free: | |
e9193059 | 736 | __putname(name); |
1da177e4 LT |
737 | out_put: |
738 | iput(inode); | |
739 | out: | |
f1adc05e | 740 | return err; |
1da177e4 LT |
741 | } |
742 | ||
743 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
744 | struct inode *to_ino, struct dentry *to) | |
745 | { | |
746 | char *from_name, *to_name; | |
747 | int err; | |
748 | ||
c5322220 | 749 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 750 | return -ENOMEM; |
c5322220 | 751 | if ((to_name = dentry_name(to)) == NULL) { |
e9193059 | 752 | __putname(from_name); |
f1adc05e | 753 | return -ENOMEM; |
1da177e4 LT |
754 | } |
755 | err = rename_file(from_name, to_name); | |
e9193059 AV |
756 | __putname(from_name); |
757 | __putname(to_name); | |
f1adc05e | 758 | return err; |
1da177e4 LT |
759 | } |
760 | ||
10556cb2 | 761 | int hostfs_permission(struct inode *ino, int desired) |
1da177e4 LT |
762 | { |
763 | char *name; | |
764 | int r = 0, w = 0, x = 0, err; | |
765 | ||
10556cb2 | 766 | if (desired & MAY_NOT_BLOCK) |
b74c79e9 NP |
767 | return -ECHILD; |
768 | ||
1da177e4 LT |
769 | if (desired & MAY_READ) r = 1; |
770 | if (desired & MAY_WRITE) w = 1; | |
771 | if (desired & MAY_EXEC) x = 1; | |
c5322220 | 772 | name = inode_name(ino); |
f1adc05e JD |
773 | if (name == NULL) |
774 | return -ENOMEM; | |
1da177e4 LT |
775 | |
776 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 777 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
778 | err = 0; |
779 | else | |
780 | err = access_file(name, r, w, x); | |
e9193059 | 781 | __putname(name); |
84b3db04 | 782 | if (!err) |
2830ba7f | 783 | err = generic_permission(ino, desired); |
1da177e4 LT |
784 | return err; |
785 | } | |
786 | ||
787 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
788 | { | |
1025774c | 789 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
790 | struct hostfs_iattr attrs; |
791 | char *name; | |
792 | int err; | |
793 | ||
1025774c | 794 | int fd = HOSTFS_I(inode)->fd; |
5822b7fa | 795 | |
1025774c | 796 | err = inode_change_ok(inode, attr); |
1da177e4 LT |
797 | if (err) |
798 | return err; | |
799 | ||
84b3db04 | 800 | if (append) |
1da177e4 LT |
801 | attr->ia_valid &= ~ATTR_SIZE; |
802 | ||
803 | attrs.ia_valid = 0; | |
84b3db04 | 804 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
805 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
806 | attrs.ia_mode = attr->ia_mode; | |
807 | } | |
84b3db04 | 808 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 | 809 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
29f82ae5 | 810 | attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid); |
1da177e4 | 811 | } |
84b3db04 | 812 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 | 813 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
29f82ae5 | 814 | attrs.ia_gid = from_kgid(&init_user_ns, attr->ia_gid); |
1da177e4 | 815 | } |
84b3db04 | 816 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
817 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
818 | attrs.ia_size = attr->ia_size; | |
819 | } | |
84b3db04 | 820 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
821 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
822 | attrs.ia_atime = attr->ia_atime; | |
823 | } | |
84b3db04 | 824 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
825 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
826 | attrs.ia_mtime = attr->ia_mtime; | |
827 | } | |
84b3db04 | 828 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
829 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
830 | attrs.ia_ctime = attr->ia_ctime; | |
831 | } | |
84b3db04 | 832 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
833 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
834 | } | |
84b3db04 | 835 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
836 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
837 | } | |
c5322220 | 838 | name = dentry_name(dentry); |
84b3db04 | 839 | if (name == NULL) |
f1adc05e | 840 | return -ENOMEM; |
5822b7fa | 841 | err = set_attr(name, &attrs, fd); |
e9193059 | 842 | __putname(name); |
84b3db04 | 843 | if (err) |
f1adc05e | 844 | return err; |
1da177e4 | 845 | |
1025774c | 846 | if ((attr->ia_valid & ATTR_SIZE) && |
bc077320 | 847 | attr->ia_size != i_size_read(inode)) |
3be2be0a | 848 | truncate_setsize(inode, attr->ia_size); |
1025774c CH |
849 | |
850 | setattr_copy(inode, attr); | |
851 | mark_inode_dirty(inode); | |
852 | return 0; | |
1da177e4 LT |
853 | } |
854 | ||
92e1d5be | 855 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
856 | .permission = hostfs_permission, |
857 | .setattr = hostfs_setattr, | |
1da177e4 LT |
858 | }; |
859 | ||
92e1d5be | 860 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
861 | .create = hostfs_create, |
862 | .lookup = hostfs_lookup, | |
863 | .link = hostfs_link, | |
864 | .unlink = hostfs_unlink, | |
865 | .symlink = hostfs_symlink, | |
866 | .mkdir = hostfs_mkdir, | |
867 | .rmdir = hostfs_rmdir, | |
868 | .mknod = hostfs_mknod, | |
869 | .rename = hostfs_rename, | |
1da177e4 LT |
870 | .permission = hostfs_permission, |
871 | .setattr = hostfs_setattr, | |
1da177e4 LT |
872 | }; |
873 | ||
d0352d3e AV |
874 | static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
875 | { | |
876 | char *link = __getname(); | |
877 | if (link) { | |
878 | char *path = dentry_name(dentry); | |
879 | int err = -ENOMEM; | |
880 | if (path) { | |
3b6036d1 | 881 | err = hostfs_do_readlink(path, link, PATH_MAX); |
d0352d3e AV |
882 | if (err == PATH_MAX) |
883 | err = -E2BIG; | |
e9193059 | 884 | __putname(path); |
d0352d3e AV |
885 | } |
886 | if (err < 0) { | |
887 | __putname(link); | |
888 | link = ERR_PTR(err); | |
889 | } | |
890 | } else { | |
891 | link = ERR_PTR(-ENOMEM); | |
1da177e4 | 892 | } |
d0352d3e AV |
893 | |
894 | nd_set_link(nd, link); | |
895 | return NULL; | |
896 | } | |
897 | ||
898 | static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) | |
899 | { | |
900 | char *s = nd_get_link(nd); | |
901 | if (!IS_ERR(s)) | |
902 | __putname(s); | |
1da177e4 LT |
903 | } |
904 | ||
d0352d3e AV |
905 | static const struct inode_operations hostfs_link_iops = { |
906 | .readlink = generic_readlink, | |
907 | .follow_link = hostfs_follow_link, | |
908 | .put_link = hostfs_put_link, | |
1da177e4 LT |
909 | }; |
910 | ||
911 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
912 | { | |
913 | struct inode *root_inode; | |
75e8defb | 914 | char *host_root_path, *req_root = d; |
1da177e4 LT |
915 | int err; |
916 | ||
917 | sb->s_blocksize = 1024; | |
918 | sb->s_blocksize_bits = 10; | |
919 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
920 | sb->s_op = &hostfs_sbops; | |
f772c4a6 | 921 | sb->s_d_op = &hostfs_dentry_ops; |
752fa51e | 922 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
1da177e4 | 923 | |
a6eb0be6 | 924 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
925 | if (req_root == NULL) |
926 | req_root = ""; | |
1da177e4 LT |
927 | |
928 | err = -ENOMEM; | |
601d2c38 AV |
929 | sb->s_fs_info = host_root_path = |
930 | kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); | |
84b3db04 | 931 | if (host_root_path == NULL) |
1da177e4 LT |
932 | goto out; |
933 | ||
75e8defb | 934 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 | 935 | |
52b209f7 AV |
936 | root_inode = new_inode(sb); |
937 | if (!root_inode) | |
601d2c38 | 938 | goto out; |
1da177e4 | 939 | |
4754b825 AV |
940 | err = read_name(root_inode, host_root_path); |
941 | if (err) | |
942 | goto out_put; | |
52b209f7 | 943 | |
4754b825 | 944 | if (S_ISLNK(root_inode->i_mode)) { |
52b209f7 AV |
945 | char *name = follow_link(host_root_path); |
946 | if (IS_ERR(name)) | |
947 | err = PTR_ERR(name); | |
948 | else | |
949 | err = read_name(root_inode, name); | |
950 | kfree(name); | |
4754b825 AV |
951 | if (err) |
952 | goto out_put; | |
52b209f7 | 953 | } |
1da177e4 | 954 | |
1da177e4 | 955 | err = -ENOMEM; |
48fde701 | 956 | sb->s_root = d_make_root(root_inode); |
84b3db04 | 957 | if (sb->s_root == NULL) |
48fde701 | 958 | goto out; |
1da177e4 | 959 | |
f1adc05e | 960 | return 0; |
1da177e4 | 961 | |
f1adc05e JD |
962 | out_put: |
963 | iput(root_inode); | |
f1adc05e JD |
964 | out: |
965 | return err; | |
1da177e4 LT |
966 | } |
967 | ||
3c26ff6e | 968 | static struct dentry *hostfs_read_sb(struct file_system_type *type, |
454e2398 | 969 | int flags, const char *dev_name, |
3c26ff6e | 970 | void *data) |
1da177e4 | 971 | { |
3c26ff6e | 972 | return mount_nodev(type, flags, data, hostfs_fill_sb_common); |
1da177e4 LT |
973 | } |
974 | ||
601d2c38 AV |
975 | static void hostfs_kill_sb(struct super_block *s) |
976 | { | |
977 | kill_anon_super(s); | |
978 | kfree(s->s_fs_info); | |
979 | } | |
980 | ||
1da177e4 LT |
981 | static struct file_system_type hostfs_type = { |
982 | .owner = THIS_MODULE, | |
983 | .name = "hostfs", | |
3c26ff6e | 984 | .mount = hostfs_read_sb, |
601d2c38 | 985 | .kill_sb = hostfs_kill_sb, |
1da177e4 LT |
986 | .fs_flags = 0, |
987 | }; | |
3e64fe5b | 988 | MODULE_ALIAS_FS("hostfs"); |
1da177e4 LT |
989 | |
990 | static int __init init_hostfs(void) | |
991 | { | |
f1adc05e | 992 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
993 | } |
994 | ||
995 | static void __exit exit_hostfs(void) | |
996 | { | |
997 | unregister_filesystem(&hostfs_type); | |
998 | } | |
999 | ||
1000 | module_init(init_hostfs) | |
1001 | module_exit(exit_hostfs) | |
1002 | MODULE_LICENSE("GPL"); |