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 | |
1da177e4 | 36 | /* Changed in hostfs_args before the kernel starts running */ |
a6eb0be6 | 37 | static char *root_ino = ""; |
1da177e4 LT |
38 | static int append = 0; |
39 | ||
92e1d5be AV |
40 | static const struct inode_operations hostfs_iops; |
41 | static const struct inode_operations hostfs_dir_iops; | |
d0352d3e | 42 | static const struct inode_operations hostfs_link_iops; |
1da177e4 LT |
43 | |
44 | #ifndef MODULE | |
45 | static int __init hostfs_args(char *options, int *add) | |
46 | { | |
47 | char *ptr; | |
48 | ||
49 | ptr = strchr(options, ','); | |
84b3db04 | 50 | if (ptr != NULL) |
1da177e4 | 51 | *ptr++ = '\0'; |
84b3db04 | 52 | if (*options != '\0') |
1da177e4 LT |
53 | root_ino = options; |
54 | ||
55 | options = ptr; | |
84b3db04 | 56 | while (options) { |
1da177e4 | 57 | ptr = strchr(options, ','); |
84b3db04 | 58 | if (ptr != NULL) |
1da177e4 | 59 | *ptr++ = '\0'; |
84b3db04 JD |
60 | if (*options != '\0') { |
61 | if (!strcmp(options, "append")) | |
1da177e4 LT |
62 | append = 1; |
63 | else printf("hostfs_args - unsupported option - %s\n", | |
64 | options); | |
65 | } | |
66 | options = ptr; | |
67 | } | |
f1adc05e | 68 | return 0; |
1da177e4 LT |
69 | } |
70 | ||
71 | __uml_setup("hostfs=", hostfs_args, | |
72 | "hostfs=<root dir>,<flags>,...\n" | |
73 | " This is used to set hostfs parameters. The root directory argument\n" | |
74 | " is used to confine all hostfs mounts to within the specified directory\n" | |
75 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
76 | " mount anything on the host that's accessible to the user that's running\n" | |
77 | " it.\n" | |
78 | " The only flag currently supported is 'append', which specifies that all\n" | |
79 | " files opened by hostfs will be opened in append mode.\n\n" | |
80 | ); | |
81 | #endif | |
82 | ||
e9193059 | 83 | static char *__dentry_name(struct dentry *dentry, char *name) |
1da177e4 | 84 | { |
ec2447c2 | 85 | char *p = dentry_path_raw(dentry, name, PATH_MAX); |
e9193059 AV |
86 | char *root; |
87 | size_t len; | |
1da177e4 | 88 | |
e9193059 AV |
89 | root = dentry->d_sb->s_fs_info; |
90 | len = strlen(root); | |
91 | if (IS_ERR(p)) { | |
92 | __putname(name); | |
f1adc05e | 93 | return NULL; |
1da177e4 | 94 | } |
850a496f | 95 | strlcpy(name, root, PATH_MAX); |
e9193059 AV |
96 | if (len > p - name) { |
97 | __putname(name); | |
98 | return NULL; | |
99 | } | |
100 | if (p > name + len) { | |
101 | char *s = name + len; | |
102 | while ((*s++ = *p++) != '\0') | |
103 | ; | |
104 | } | |
f1adc05e | 105 | return name; |
1da177e4 LT |
106 | } |
107 | ||
e9193059 AV |
108 | static char *dentry_name(struct dentry *dentry) |
109 | { | |
110 | char *name = __getname(); | |
111 | if (!name) | |
112 | return NULL; | |
113 | ||
9dcc5e8a | 114 | return __dentry_name(dentry, name); |
e9193059 AV |
115 | } |
116 | ||
c5322220 | 117 | static char *inode_name(struct inode *ino) |
1da177e4 LT |
118 | { |
119 | struct dentry *dentry; | |
ec2447c2 | 120 | char *name; |
1da177e4 | 121 | |
ec2447c2 NP |
122 | dentry = d_find_alias(ino); |
123 | if (!dentry) | |
e9193059 | 124 | return NULL; |
ec2447c2 NP |
125 | |
126 | name = dentry_name(dentry); | |
127 | ||
128 | dput(dentry); | |
129 | ||
130 | return name; | |
1da177e4 LT |
131 | } |
132 | ||
1da177e4 LT |
133 | static char *follow_link(char *link) |
134 | { | |
135 | int len, n; | |
136 | char *name, *resolved, *end; | |
137 | ||
138 | len = 64; | |
84b3db04 | 139 | while (1) { |
1da177e4 LT |
140 | n = -ENOMEM; |
141 | name = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 142 | if (name == NULL) |
1da177e4 LT |
143 | goto out; |
144 | ||
ea7e743e | 145 | n = hostfs_do_readlink(link, name, len); |
84b3db04 | 146 | if (n < len) |
1da177e4 LT |
147 | break; |
148 | len *= 2; | |
149 | kfree(name); | |
150 | } | |
84b3db04 | 151 | if (n < 0) |
1da177e4 LT |
152 | goto out_free; |
153 | ||
84b3db04 | 154 | if (*name == '/') |
f1adc05e | 155 | return name; |
1da177e4 LT |
156 | |
157 | end = strrchr(link, '/'); | |
84b3db04 | 158 | if (end == NULL) |
f1adc05e | 159 | return name; |
1da177e4 LT |
160 | |
161 | *(end + 1) = '\0'; | |
162 | len = strlen(link) + strlen(name) + 1; | |
163 | ||
164 | resolved = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 165 | if (resolved == NULL) { |
1da177e4 LT |
166 | n = -ENOMEM; |
167 | goto out_free; | |
168 | } | |
169 | ||
170 | sprintf(resolved, "%s%s", link, name); | |
171 | kfree(name); | |
172 | kfree(link); | |
f1adc05e | 173 | return resolved; |
1da177e4 LT |
174 | |
175 | out_free: | |
176 | kfree(name); | |
177 | out: | |
f1adc05e | 178 | return ERR_PTR(n); |
1da177e4 LT |
179 | } |
180 | ||
0a370e5d DH |
181 | static struct inode *hostfs_iget(struct super_block *sb) |
182 | { | |
52b209f7 | 183 | struct inode *inode = new_inode(sb); |
0a370e5d DH |
184 | if (!inode) |
185 | return ERR_PTR(-ENOMEM); | |
0a370e5d DH |
186 | return inode; |
187 | } | |
188 | ||
9e443bc3 | 189 | static int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 | 190 | { |
84b3db04 JD |
191 | /* |
192 | * do_statfs uses struct statfs64 internally, but the linux kernel | |
1da177e4 LT |
193 | * struct statfs still has 32-bit versions for most of these fields, |
194 | * so we convert them here | |
195 | */ | |
196 | int err; | |
197 | long long f_blocks; | |
198 | long long f_bfree; | |
199 | long long f_bavail; | |
200 | long long f_files; | |
201 | long long f_ffree; | |
202 | ||
601d2c38 | 203 | err = do_statfs(dentry->d_sb->s_fs_info, |
1da177e4 LT |
204 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
205 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
1b627d57 | 206 | &sf->f_namelen); |
84b3db04 | 207 | if (err) |
f1adc05e | 208 | return err; |
1da177e4 LT |
209 | sf->f_blocks = f_blocks; |
210 | sf->f_bfree = f_bfree; | |
211 | sf->f_bavail = f_bavail; | |
212 | sf->f_files = f_files; | |
213 | sf->f_ffree = f_ffree; | |
214 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
f1adc05e | 215 | return 0; |
1da177e4 LT |
216 | } |
217 | ||
218 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
219 | { | |
220 | struct hostfs_inode_info *hi; | |
221 | ||
371fdab1 | 222 | hi = kmalloc(sizeof(*hi), GFP_KERNEL); |
84b3db04 | 223 | if (hi == NULL) |
f1adc05e | 224 | return NULL; |
601d2c38 | 225 | hi->fd = -1; |
371fdab1 | 226 | hi->mode = 0; |
1da177e4 | 227 | inode_init_once(&hi->vfs_inode); |
f1adc05e | 228 | return &hi->vfs_inode; |
1da177e4 LT |
229 | } |
230 | ||
e971a6d7 | 231 | static void hostfs_evict_inode(struct inode *inode) |
1da177e4 | 232 | { |
91b0abe3 | 233 | truncate_inode_pages_final(&inode->i_data); |
dbd5768f | 234 | clear_inode(inode); |
84b3db04 | 235 | if (HOSTFS_I(inode)->fd != -1) { |
1da177e4 LT |
236 | close_file(&HOSTFS_I(inode)->fd); |
237 | HOSTFS_I(inode)->fd = -1; | |
238 | } | |
1da177e4 LT |
239 | } |
240 | ||
fa0d7e3d | 241 | static void hostfs_i_callback(struct rcu_head *head) |
1da177e4 | 242 | { |
fa0d7e3d | 243 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
244 | kfree(HOSTFS_I(inode)); |
245 | } | |
fa0d7e3d NP |
246 | |
247 | static void hostfs_destroy_inode(struct inode *inode) | |
248 | { | |
249 | call_rcu(&inode->i_rcu, hostfs_i_callback); | |
250 | } | |
1da177e4 | 251 | |
34c80b1d | 252 | static int hostfs_show_options(struct seq_file *seq, struct dentry *root) |
dd2cc4df | 253 | { |
34c80b1d | 254 | const char *root_path = root->d_sb->s_fs_info; |
dd2cc4df MS |
255 | size_t offset = strlen(root_ino) + 1; |
256 | ||
257 | if (strlen(root_path) > offset) | |
258 | seq_printf(seq, ",%s", root_path + offset); | |
259 | ||
260 | return 0; | |
261 | } | |
262 | ||
ee9b6d61 | 263 | static const struct super_operations hostfs_sbops = { |
1da177e4 | 264 | .alloc_inode = hostfs_alloc_inode, |
1da177e4 | 265 | .destroy_inode = hostfs_destroy_inode, |
e971a6d7 | 266 | .evict_inode = hostfs_evict_inode, |
1da177e4 | 267 | .statfs = hostfs_statfs, |
dd2cc4df | 268 | .show_options = hostfs_show_options, |
1da177e4 LT |
269 | }; |
270 | ||
9e443bc3 | 271 | static int hostfs_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 LT |
272 | { |
273 | void *dir; | |
274 | char *name; | |
275 | unsigned long long next, ino; | |
276 | int error, len; | |
3ee6bd8e | 277 | unsigned int type; |
1da177e4 | 278 | |
c5322220 | 279 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 280 | if (name == NULL) |
f1adc05e | 281 | return -ENOMEM; |
1da177e4 | 282 | dir = open_dir(name, &error); |
e9193059 | 283 | __putname(name); |
84b3db04 | 284 | if (dir == NULL) |
f1adc05e | 285 | return -error; |
8e28bc7e | 286 | next = ctx->pos; |
3ee6bd8e | 287 | while ((name = read_dir(dir, &next, &ino, &len, &type)) != NULL) { |
8e28bc7e AV |
288 | if (!dir_emit(ctx, name, len, ino, type)) |
289 | break; | |
290 | ctx->pos = next; | |
1da177e4 LT |
291 | } |
292 | close_dir(dir); | |
f1adc05e | 293 | return 0; |
1da177e4 LT |
294 | } |
295 | ||
9e443bc3 | 296 | static int hostfs_file_open(struct inode *ino, struct file *file) |
1da177e4 | 297 | { |
f8ad850f | 298 | static DEFINE_MUTEX(open_mutex); |
1da177e4 | 299 | char *name; |
aeb5d727 | 300 | fmode_t mode = 0; |
f8ad850f | 301 | int err; |
aeb5d727 | 302 | int r = 0, w = 0, fd; |
1da177e4 LT |
303 | |
304 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 305 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 306 | return 0; |
1da177e4 | 307 | |
f8ad850f | 308 | mode |= HOSTFS_I(ino)->mode; |
1da177e4 | 309 | |
f8ad850f AV |
310 | retry: |
311 | if (mode & FMODE_READ) | |
1da177e4 | 312 | r = 1; |
f8ad850f | 313 | if (mode & FMODE_WRITE) |
1da177e4 | 314 | w = 1; |
84b3db04 | 315 | if (w) |
1da177e4 LT |
316 | r = 1; |
317 | ||
c5322220 | 318 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 319 | if (name == NULL) |
f1adc05e | 320 | return -ENOMEM; |
1da177e4 LT |
321 | |
322 | fd = open_file(name, r, w, append); | |
e9193059 | 323 | __putname(name); |
84b3db04 | 324 | if (fd < 0) |
f1adc05e | 325 | return fd; |
f8ad850f AV |
326 | |
327 | mutex_lock(&open_mutex); | |
328 | /* somebody else had handled it first? */ | |
329 | if ((mode & HOSTFS_I(ino)->mode) == mode) { | |
330 | mutex_unlock(&open_mutex); | |
331 | return 0; | |
332 | } | |
333 | if ((mode | HOSTFS_I(ino)->mode) != mode) { | |
334 | mode |= HOSTFS_I(ino)->mode; | |
335 | mutex_unlock(&open_mutex); | |
336 | close_file(&fd); | |
337 | goto retry; | |
338 | } | |
339 | if (HOSTFS_I(ino)->fd == -1) { | |
340 | HOSTFS_I(ino)->fd = fd; | |
341 | } else { | |
342 | err = replace_file(fd, HOSTFS_I(ino)->fd); | |
343 | close_file(&fd); | |
344 | if (err < 0) { | |
345 | mutex_unlock(&open_mutex); | |
346 | return err; | |
347 | } | |
348 | } | |
349 | HOSTFS_I(ino)->mode = mode; | |
350 | mutex_unlock(&open_mutex); | |
1da177e4 | 351 | |
f1adc05e | 352 | return 0; |
1da177e4 LT |
353 | } |
354 | ||
65984ff9 RW |
355 | static int hostfs_file_release(struct inode *inode, struct file *file) |
356 | { | |
357 | filemap_write_and_wait(inode->i_mapping); | |
358 | ||
359 | return 0; | |
360 | } | |
361 | ||
9e443bc3 JH |
362 | static int hostfs_fsync(struct file *file, loff_t start, loff_t end, |
363 | int datasync) | |
1da177e4 | 364 | { |
02c24a82 JB |
365 | struct inode *inode = file->f_mapping->host; |
366 | int ret; | |
367 | ||
368 | ret = filemap_write_and_wait_range(inode->i_mapping, start, end); | |
369 | if (ret) | |
370 | return ret; | |
371 | ||
372 | mutex_lock(&inode->i_mutex); | |
373 | ret = fsync_file(HOSTFS_I(inode)->fd, datasync); | |
374 | mutex_unlock(&inode->i_mutex); | |
375 | ||
376 | return ret; | |
1da177e4 LT |
377 | } |
378 | ||
4b6f5d20 | 379 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 380 | .llseek = generic_file_llseek, |
5ffc4ef4 | 381 | .splice_read = generic_file_splice_read, |
aad4f8bb | 382 | .read_iter = generic_file_read_iter, |
8174202b | 383 | .write_iter = generic_file_write_iter, |
1da177e4 LT |
384 | .mmap = generic_file_mmap, |
385 | .open = hostfs_file_open, | |
65984ff9 | 386 | .release = hostfs_file_release, |
1da177e4 LT |
387 | .fsync = hostfs_fsync, |
388 | }; | |
389 | ||
4b6f5d20 | 390 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 | 391 | .llseek = generic_file_llseek, |
8e28bc7e | 392 | .iterate = hostfs_readdir, |
1da177e4 LT |
393 | .read = generic_read_dir, |
394 | }; | |
395 | ||
9e443bc3 | 396 | static int hostfs_writepage(struct page *page, struct writeback_control *wbc) |
1da177e4 LT |
397 | { |
398 | struct address_space *mapping = page->mapping; | |
399 | struct inode *inode = mapping->host; | |
400 | char *buffer; | |
401 | unsigned long long base; | |
402 | int count = PAGE_CACHE_SIZE; | |
403 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
404 | int err; | |
405 | ||
406 | if (page->index >= end_index) | |
407 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
408 | ||
409 | buffer = kmap(page); | |
410 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
411 | ||
412 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 413 | if (err != count) { |
1da177e4 LT |
414 | ClearPageUptodate(page); |
415 | goto out; | |
416 | } | |
417 | ||
418 | if (base > inode->i_size) | |
419 | inode->i_size = base; | |
420 | ||
421 | if (PageError(page)) | |
422 | ClearPageError(page); | |
423 | err = 0; | |
424 | ||
425 | out: | |
426 | kunmap(page); | |
427 | ||
428 | unlock_page(page); | |
429 | return err; | |
430 | } | |
431 | ||
9e443bc3 | 432 | static int hostfs_readpage(struct file *file, struct page *page) |
1da177e4 LT |
433 | { |
434 | char *buffer; | |
435 | long long start; | |
436 | int err = 0; | |
437 | ||
438 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
439 | buffer = kmap(page); | |
440 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
441 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
442 | if (err < 0) |
443 | goto out; | |
1da177e4 LT |
444 | |
445 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
446 | ||
447 | flush_dcache_page(page); | |
448 | SetPageUptodate(page); | |
449 | if (PageError(page)) ClearPageError(page); | |
450 | err = 0; | |
451 | out: | |
452 | kunmap(page); | |
453 | unlock_page(page); | |
f1adc05e | 454 | return err; |
1da177e4 LT |
455 | } |
456 | ||
9e443bc3 JH |
457 | static int hostfs_write_begin(struct file *file, struct address_space *mapping, |
458 | loff_t pos, unsigned len, unsigned flags, | |
459 | struct page **pagep, void **fsdata) | |
1da177e4 | 460 | { |
ae361ff4 | 461 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 462 | |
54566b2c | 463 | *pagep = grab_cache_page_write_begin(mapping, index, flags); |
ae361ff4 NP |
464 | if (!*pagep) |
465 | return -ENOMEM; | |
466 | return 0; | |
1da177e4 LT |
467 | } |
468 | ||
9e443bc3 JH |
469 | static int hostfs_write_end(struct file *file, struct address_space *mapping, |
470 | loff_t pos, unsigned len, unsigned copied, | |
471 | struct page *page, void *fsdata) | |
1da177e4 | 472 | { |
1da177e4 | 473 | struct inode *inode = mapping->host; |
ae361ff4 NP |
474 | void *buffer; |
475 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
476 | int err; | |
1da177e4 | 477 | |
1da177e4 | 478 | buffer = kmap(page); |
ae361ff4 NP |
479 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
480 | kunmap(page); | |
30f04a4e | 481 | |
ae361ff4 NP |
482 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
483 | SetPageUptodate(page); | |
30f04a4e | 484 | |
84b3db04 JD |
485 | /* |
486 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
487 | * i_size against the last byte written. |
488 | */ | |
489 | if (err > 0 && (pos > inode->i_size)) | |
490 | inode->i_size = pos; | |
491 | unlock_page(page); | |
492 | page_cache_release(page); | |
1da177e4 | 493 | |
f1adc05e | 494 | return err; |
1da177e4 LT |
495 | } |
496 | ||
f5e54d6e | 497 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
498 | .writepage = hostfs_writepage, |
499 | .readpage = hostfs_readpage, | |
ffa0aea6 | 500 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
501 | .write_begin = hostfs_write_begin, |
502 | .write_end = hostfs_write_end, | |
1da177e4 LT |
503 | }; |
504 | ||
4754b825 | 505 | static int read_name(struct inode *ino, char *name) |
1da177e4 | 506 | { |
4754b825 AV |
507 | dev_t rdev; |
508 | struct hostfs_stat st; | |
509 | int err = stat_file(name, &st, -1); | |
510 | if (err) | |
511 | return err; | |
1da177e4 | 512 | |
5e2df28c | 513 | /* Reencode maj and min with the kernel encoding.*/ |
4754b825 | 514 | rdev = MKDEV(st.maj, st.min); |
1da177e4 | 515 | |
4754b825 AV |
516 | switch (st.mode & S_IFMT) { |
517 | case S_IFLNK: | |
d0352d3e | 518 | ino->i_op = &hostfs_link_iops; |
1da177e4 | 519 | break; |
4754b825 AV |
520 | case S_IFDIR: |
521 | ino->i_op = &hostfs_dir_iops; | |
522 | ino->i_fop = &hostfs_dir_fops; | |
1da177e4 | 523 | break; |
4754b825 AV |
524 | case S_IFCHR: |
525 | case S_IFBLK: | |
526 | case S_IFIFO: | |
527 | case S_IFSOCK: | |
528 | init_special_inode(ino, st.mode & S_IFMT, rdev); | |
529 | ino->i_op = &hostfs_iops; | |
1da177e4 | 530 | break; |
4754b825 AV |
531 | |
532 | default: | |
533 | ino->i_op = &hostfs_iops; | |
534 | ino->i_fop = &hostfs_file_fops; | |
535 | ino->i_mapping->a_ops = &hostfs_aops; | |
1da177e4 | 536 | } |
4754b825 AV |
537 | |
538 | ino->i_ino = st.ino; | |
539 | ino->i_mode = st.mode; | |
bfe86848 | 540 | set_nlink(ino, st.nlink); |
29f82ae5 EB |
541 | i_uid_write(ino, st.uid); |
542 | i_gid_write(ino, st.gid); | |
4754b825 AV |
543 | ino->i_atime = st.atime; |
544 | ino->i_mtime = st.mtime; | |
545 | ino->i_ctime = st.ctime; | |
546 | ino->i_size = st.size; | |
547 | ino->i_blocks = st.blocks; | |
548 | return 0; | |
1da177e4 LT |
549 | } |
550 | ||
9e443bc3 JH |
551 | static int hostfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
552 | bool excl) | |
1da177e4 LT |
553 | { |
554 | struct inode *inode; | |
555 | char *name; | |
556 | int error, fd; | |
557 | ||
0a370e5d DH |
558 | inode = hostfs_iget(dir->i_sb); |
559 | if (IS_ERR(inode)) { | |
560 | error = PTR_ERR(inode); | |
84b3db04 | 561 | goto out; |
0a370e5d | 562 | } |
1da177e4 | 563 | |
1da177e4 | 564 | error = -ENOMEM; |
c5322220 | 565 | name = dentry_name(dentry); |
84b3db04 | 566 | if (name == NULL) |
1da177e4 LT |
567 | goto out_put; |
568 | ||
569 | fd = file_create(name, | |
570 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
571 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
572 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
4754b825 | 573 | if (fd < 0) |
1da177e4 | 574 | error = fd; |
4754b825 | 575 | else |
5e2df28c | 576 | error = read_name(inode, name); |
1da177e4 | 577 | |
e9193059 | 578 | __putname(name); |
84b3db04 | 579 | if (error) |
1da177e4 LT |
580 | goto out_put; |
581 | ||
582 | HOSTFS_I(inode)->fd = fd; | |
583 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
584 | d_instantiate(dentry, inode); | |
f1adc05e | 585 | return 0; |
1da177e4 LT |
586 | |
587 | out_put: | |
588 | iput(inode); | |
589 | out: | |
f1adc05e | 590 | return error; |
1da177e4 LT |
591 | } |
592 | ||
9e443bc3 JH |
593 | static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, |
594 | unsigned int flags) | |
1da177e4 LT |
595 | { |
596 | struct inode *inode; | |
597 | char *name; | |
598 | int err; | |
599 | ||
0a370e5d DH |
600 | inode = hostfs_iget(ino->i_sb); |
601 | if (IS_ERR(inode)) { | |
602 | err = PTR_ERR(inode); | |
1da177e4 | 603 | goto out; |
0a370e5d | 604 | } |
1da177e4 | 605 | |
1da177e4 | 606 | err = -ENOMEM; |
c5322220 | 607 | name = dentry_name(dentry); |
84b3db04 | 608 | if (name == NULL) |
1da177e4 LT |
609 | goto out_put; |
610 | ||
611 | err = read_name(inode, name); | |
5e2df28c | 612 | |
e9193059 | 613 | __putname(name); |
84b3db04 | 614 | if (err == -ENOENT) { |
1da177e4 LT |
615 | iput(inode); |
616 | inode = NULL; | |
617 | } | |
84b3db04 | 618 | else if (err) |
1da177e4 LT |
619 | goto out_put; |
620 | ||
621 | d_add(dentry, inode); | |
f1adc05e | 622 | return NULL; |
1da177e4 LT |
623 | |
624 | out_put: | |
625 | iput(inode); | |
626 | out: | |
f1adc05e | 627 | return ERR_PTR(err); |
1da177e4 LT |
628 | } |
629 | ||
9e443bc3 JH |
630 | static int hostfs_link(struct dentry *to, struct inode *ino, |
631 | struct dentry *from) | |
1da177e4 | 632 | { |
f1adc05e JD |
633 | char *from_name, *to_name; |
634 | int err; | |
1da177e4 | 635 | |
c5322220 | 636 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 637 | return -ENOMEM; |
c5322220 | 638 | to_name = dentry_name(to); |
84b3db04 | 639 | if (to_name == NULL) { |
e9193059 | 640 | __putname(from_name); |
f1adc05e | 641 | return -ENOMEM; |
1da177e4 | 642 | } |
f1adc05e | 643 | err = link_file(to_name, from_name); |
e9193059 AV |
644 | __putname(from_name); |
645 | __putname(to_name); | |
f1adc05e | 646 | return err; |
1da177e4 LT |
647 | } |
648 | ||
9e443bc3 | 649 | static int hostfs_unlink(struct inode *ino, struct dentry *dentry) |
1da177e4 LT |
650 | { |
651 | char *file; | |
652 | int err; | |
653 | ||
84b3db04 | 654 | if (append) |
f1adc05e | 655 | return -EPERM; |
1da177e4 | 656 | |
f8d7e187 AV |
657 | if ((file = dentry_name(dentry)) == NULL) |
658 | return -ENOMEM; | |
659 | ||
1da177e4 | 660 | err = unlink_file(file); |
e9193059 | 661 | __putname(file); |
f1adc05e | 662 | return err; |
1da177e4 LT |
663 | } |
664 | ||
9e443bc3 JH |
665 | static int hostfs_symlink(struct inode *ino, struct dentry *dentry, |
666 | const char *to) | |
1da177e4 LT |
667 | { |
668 | char *file; | |
669 | int err; | |
670 | ||
c5322220 | 671 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 672 | return -ENOMEM; |
1da177e4 | 673 | err = make_symlink(file, to); |
e9193059 | 674 | __putname(file); |
f1adc05e | 675 | return err; |
1da177e4 LT |
676 | } |
677 | ||
9e443bc3 | 678 | static int hostfs_mkdir(struct inode *ino, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
679 | { |
680 | char *file; | |
681 | int err; | |
682 | ||
c5322220 | 683 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 684 | return -ENOMEM; |
1da177e4 | 685 | err = do_mkdir(file, mode); |
e9193059 | 686 | __putname(file); |
f1adc05e | 687 | return err; |
1da177e4 LT |
688 | } |
689 | ||
9e443bc3 | 690 | static int hostfs_rmdir(struct inode *ino, struct dentry *dentry) |
1da177e4 LT |
691 | { |
692 | char *file; | |
693 | int err; | |
694 | ||
c5322220 | 695 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 696 | return -ENOMEM; |
1da177e4 | 697 | err = do_rmdir(file); |
e9193059 | 698 | __putname(file); |
f1adc05e | 699 | return err; |
1da177e4 LT |
700 | } |
701 | ||
1a67aafb | 702 | static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
1da177e4 LT |
703 | { |
704 | struct inode *inode; | |
705 | char *name; | |
0a370e5d | 706 | int err; |
1da177e4 | 707 | |
0a370e5d DH |
708 | inode = hostfs_iget(dir->i_sb); |
709 | if (IS_ERR(inode)) { | |
710 | err = PTR_ERR(inode); | |
1da177e4 | 711 | goto out; |
0a370e5d | 712 | } |
1da177e4 | 713 | |
1da177e4 | 714 | err = -ENOMEM; |
c5322220 | 715 | name = dentry_name(dentry); |
84b3db04 | 716 | if (name == NULL) |
1da177e4 LT |
717 | goto out_put; |
718 | ||
719 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 720 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
e9193059 | 721 | if (!err) |
1da177e4 LT |
722 | goto out_free; |
723 | ||
724 | err = read_name(inode, name); | |
e9193059 | 725 | __putname(name); |
5e2df28c AV |
726 | if (err) |
727 | goto out_put; | |
84b3db04 | 728 | if (err) |
1da177e4 LT |
729 | goto out_put; |
730 | ||
731 | d_instantiate(dentry, inode); | |
f1adc05e | 732 | return 0; |
1da177e4 LT |
733 | |
734 | out_free: | |
e9193059 | 735 | __putname(name); |
1da177e4 LT |
736 | out_put: |
737 | iput(inode); | |
738 | out: | |
f1adc05e | 739 | return err; |
1da177e4 LT |
740 | } |
741 | ||
9a423bb6 MS |
742 | static int hostfs_rename2(struct inode *old_dir, struct dentry *old_dentry, |
743 | struct inode *new_dir, struct dentry *new_dentry, | |
744 | unsigned int flags) | |
1da177e4 | 745 | { |
9a423bb6 | 746 | char *old_name, *new_name; |
1da177e4 LT |
747 | int err; |
748 | ||
9a423bb6 MS |
749 | if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) |
750 | return -EINVAL; | |
751 | ||
752 | old_name = dentry_name(old_dentry); | |
753 | if (old_name == NULL) | |
f1adc05e | 754 | return -ENOMEM; |
9a423bb6 MS |
755 | new_name = dentry_name(new_dentry); |
756 | if (new_name == NULL) { | |
757 | __putname(old_name); | |
f1adc05e | 758 | return -ENOMEM; |
1da177e4 | 759 | } |
9a423bb6 MS |
760 | if (!flags) |
761 | err = rename_file(old_name, new_name); | |
762 | else | |
763 | err = rename2_file(old_name, new_name, flags); | |
764 | ||
765 | __putname(old_name); | |
766 | __putname(new_name); | |
f1adc05e | 767 | return err; |
1da177e4 LT |
768 | } |
769 | ||
9e443bc3 | 770 | static int hostfs_permission(struct inode *ino, int desired) |
1da177e4 LT |
771 | { |
772 | char *name; | |
773 | int r = 0, w = 0, x = 0, err; | |
774 | ||
10556cb2 | 775 | if (desired & MAY_NOT_BLOCK) |
b74c79e9 NP |
776 | return -ECHILD; |
777 | ||
1da177e4 LT |
778 | if (desired & MAY_READ) r = 1; |
779 | if (desired & MAY_WRITE) w = 1; | |
780 | if (desired & MAY_EXEC) x = 1; | |
c5322220 | 781 | name = inode_name(ino); |
f1adc05e JD |
782 | if (name == NULL) |
783 | return -ENOMEM; | |
1da177e4 LT |
784 | |
785 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 786 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
787 | err = 0; |
788 | else | |
789 | err = access_file(name, r, w, x); | |
e9193059 | 790 | __putname(name); |
84b3db04 | 791 | if (!err) |
2830ba7f | 792 | err = generic_permission(ino, desired); |
1da177e4 LT |
793 | return err; |
794 | } | |
795 | ||
9e443bc3 | 796 | static int hostfs_setattr(struct dentry *dentry, struct iattr *attr) |
1da177e4 | 797 | { |
2b0143b5 | 798 | struct inode *inode = d_inode(dentry); |
1da177e4 LT |
799 | struct hostfs_iattr attrs; |
800 | char *name; | |
801 | int err; | |
802 | ||
1025774c | 803 | int fd = HOSTFS_I(inode)->fd; |
5822b7fa | 804 | |
1025774c | 805 | err = inode_change_ok(inode, attr); |
1da177e4 LT |
806 | if (err) |
807 | return err; | |
808 | ||
84b3db04 | 809 | if (append) |
1da177e4 LT |
810 | attr->ia_valid &= ~ATTR_SIZE; |
811 | ||
812 | attrs.ia_valid = 0; | |
84b3db04 | 813 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
814 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
815 | attrs.ia_mode = attr->ia_mode; | |
816 | } | |
84b3db04 | 817 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 | 818 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
29f82ae5 | 819 | attrs.ia_uid = from_kuid(&init_user_ns, attr->ia_uid); |
1da177e4 | 820 | } |
84b3db04 | 821 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 | 822 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
29f82ae5 | 823 | attrs.ia_gid = from_kgid(&init_user_ns, attr->ia_gid); |
1da177e4 | 824 | } |
84b3db04 | 825 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
826 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
827 | attrs.ia_size = attr->ia_size; | |
828 | } | |
84b3db04 | 829 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
830 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
831 | attrs.ia_atime = attr->ia_atime; | |
832 | } | |
84b3db04 | 833 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
834 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
835 | attrs.ia_mtime = attr->ia_mtime; | |
836 | } | |
84b3db04 | 837 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
838 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
839 | attrs.ia_ctime = attr->ia_ctime; | |
840 | } | |
84b3db04 | 841 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
842 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
843 | } | |
84b3db04 | 844 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
845 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
846 | } | |
c5322220 | 847 | name = dentry_name(dentry); |
84b3db04 | 848 | if (name == NULL) |
f1adc05e | 849 | return -ENOMEM; |
5822b7fa | 850 | err = set_attr(name, &attrs, fd); |
e9193059 | 851 | __putname(name); |
84b3db04 | 852 | if (err) |
f1adc05e | 853 | return err; |
1da177e4 | 854 | |
1025774c | 855 | if ((attr->ia_valid & ATTR_SIZE) && |
bc077320 | 856 | attr->ia_size != i_size_read(inode)) |
3be2be0a | 857 | truncate_setsize(inode, attr->ia_size); |
1025774c CH |
858 | |
859 | setattr_copy(inode, attr); | |
860 | mark_inode_dirty(inode); | |
861 | return 0; | |
1da177e4 LT |
862 | } |
863 | ||
92e1d5be | 864 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
865 | .permission = hostfs_permission, |
866 | .setattr = hostfs_setattr, | |
1da177e4 LT |
867 | }; |
868 | ||
92e1d5be | 869 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
870 | .create = hostfs_create, |
871 | .lookup = hostfs_lookup, | |
872 | .link = hostfs_link, | |
873 | .unlink = hostfs_unlink, | |
874 | .symlink = hostfs_symlink, | |
875 | .mkdir = hostfs_mkdir, | |
876 | .rmdir = hostfs_rmdir, | |
877 | .mknod = hostfs_mknod, | |
9a423bb6 | 878 | .rename2 = hostfs_rename2, |
1da177e4 LT |
879 | .permission = hostfs_permission, |
880 | .setattr = hostfs_setattr, | |
1da177e4 LT |
881 | }; |
882 | ||
d0352d3e AV |
883 | static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
884 | { | |
885 | char *link = __getname(); | |
886 | if (link) { | |
887 | char *path = dentry_name(dentry); | |
888 | int err = -ENOMEM; | |
889 | if (path) { | |
3b6036d1 | 890 | err = hostfs_do_readlink(path, link, PATH_MAX); |
d0352d3e AV |
891 | if (err == PATH_MAX) |
892 | err = -E2BIG; | |
e9193059 | 893 | __putname(path); |
d0352d3e AV |
894 | } |
895 | if (err < 0) { | |
896 | __putname(link); | |
897 | link = ERR_PTR(err); | |
898 | } | |
899 | } else { | |
900 | link = ERR_PTR(-ENOMEM); | |
1da177e4 | 901 | } |
d0352d3e AV |
902 | |
903 | nd_set_link(nd, link); | |
904 | return NULL; | |
905 | } | |
906 | ||
907 | static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) | |
908 | { | |
909 | char *s = nd_get_link(nd); | |
910 | if (!IS_ERR(s)) | |
911 | __putname(s); | |
1da177e4 LT |
912 | } |
913 | ||
d0352d3e AV |
914 | static const struct inode_operations hostfs_link_iops = { |
915 | .readlink = generic_readlink, | |
916 | .follow_link = hostfs_follow_link, | |
917 | .put_link = hostfs_put_link, | |
1da177e4 LT |
918 | }; |
919 | ||
920 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
921 | { | |
922 | struct inode *root_inode; | |
75e8defb | 923 | char *host_root_path, *req_root = d; |
1da177e4 LT |
924 | int err; |
925 | ||
926 | sb->s_blocksize = 1024; | |
927 | sb->s_blocksize_bits = 10; | |
928 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
929 | sb->s_op = &hostfs_sbops; | |
b26d4cd3 | 930 | sb->s_d_op = &simple_dentry_operations; |
752fa51e | 931 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
1da177e4 | 932 | |
a6eb0be6 | 933 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
934 | if (req_root == NULL) |
935 | req_root = ""; | |
1da177e4 LT |
936 | |
937 | err = -ENOMEM; | |
601d2c38 AV |
938 | sb->s_fs_info = host_root_path = |
939 | kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); | |
84b3db04 | 940 | if (host_root_path == NULL) |
1da177e4 LT |
941 | goto out; |
942 | ||
75e8defb | 943 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 | 944 | |
52b209f7 AV |
945 | root_inode = new_inode(sb); |
946 | if (!root_inode) | |
601d2c38 | 947 | goto out; |
1da177e4 | 948 | |
4754b825 AV |
949 | err = read_name(root_inode, host_root_path); |
950 | if (err) | |
951 | goto out_put; | |
52b209f7 | 952 | |
4754b825 | 953 | if (S_ISLNK(root_inode->i_mode)) { |
52b209f7 AV |
954 | char *name = follow_link(host_root_path); |
955 | if (IS_ERR(name)) | |
956 | err = PTR_ERR(name); | |
957 | else | |
958 | err = read_name(root_inode, name); | |
959 | kfree(name); | |
4754b825 AV |
960 | if (err) |
961 | goto out_put; | |
52b209f7 | 962 | } |
1da177e4 | 963 | |
1da177e4 | 964 | err = -ENOMEM; |
48fde701 | 965 | sb->s_root = d_make_root(root_inode); |
84b3db04 | 966 | if (sb->s_root == NULL) |
48fde701 | 967 | goto out; |
1da177e4 | 968 | |
f1adc05e | 969 | return 0; |
1da177e4 | 970 | |
f1adc05e JD |
971 | out_put: |
972 | iput(root_inode); | |
f1adc05e JD |
973 | out: |
974 | return err; | |
1da177e4 LT |
975 | } |
976 | ||
3c26ff6e | 977 | static struct dentry *hostfs_read_sb(struct file_system_type *type, |
454e2398 | 978 | int flags, const char *dev_name, |
3c26ff6e | 979 | void *data) |
1da177e4 | 980 | { |
3c26ff6e | 981 | return mount_nodev(type, flags, data, hostfs_fill_sb_common); |
1da177e4 LT |
982 | } |
983 | ||
601d2c38 AV |
984 | static void hostfs_kill_sb(struct super_block *s) |
985 | { | |
986 | kill_anon_super(s); | |
987 | kfree(s->s_fs_info); | |
988 | } | |
989 | ||
1da177e4 LT |
990 | static struct file_system_type hostfs_type = { |
991 | .owner = THIS_MODULE, | |
992 | .name = "hostfs", | |
3c26ff6e | 993 | .mount = hostfs_read_sb, |
601d2c38 | 994 | .kill_sb = hostfs_kill_sb, |
1da177e4 LT |
995 | .fs_flags = 0, |
996 | }; | |
3e64fe5b | 997 | MODULE_ALIAS_FS("hostfs"); |
1da177e4 LT |
998 | |
999 | static int __init init_hostfs(void) | |
1000 | { | |
f1adc05e | 1001 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
1002 | } |
1003 | ||
1004 | static void __exit exit_hostfs(void) | |
1005 | { | |
1006 | unregister_filesystem(&hostfs_type); | |
1007 | } | |
1008 | ||
1009 | module_init(init_hostfs) | |
1010 | module_exit(exit_hostfs) | |
1011 | MODULE_LICENSE("GPL"); |