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Commit | Line | Data |
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1da177e4 | 1 | /* |
f1adc05e | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Licensed under the GPL |
4 | * | |
5 | * Ported the filesystem routines to 2.5. | |
6 | * 2003-02-10 Petr Baudis <pasky@ucw.cz> | |
7 | */ | |
8 | ||
1da177e4 | 9 | #include <linux/fs.h> |
1da177e4 | 10 | #include <linux/module.h> |
84b3db04 | 11 | #include <linux/mm.h> |
1da177e4 | 12 | #include <linux/pagemap.h> |
1da177e4 | 13 | #include <linux/statfs.h> |
5a0e3ad6 | 14 | #include <linux/slab.h> |
dd2cc4df | 15 | #include <linux/seq_file.h> |
6966a977 | 16 | #include <linux/mount.h> |
d0352d3e | 17 | #include <linux/namei.h> |
1da177e4 | 18 | #include "hostfs.h" |
1da177e4 | 19 | #include "init.h" |
84b3db04 | 20 | #include "kern.h" |
1da177e4 LT |
21 | |
22 | struct hostfs_inode_info { | |
1da177e4 | 23 | int fd; |
aeb5d727 | 24 | fmode_t mode; |
1da177e4 LT |
25 | struct inode vfs_inode; |
26 | }; | |
27 | ||
28 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
29 | { | |
f1adc05e | 30 | return list_entry(inode, struct hostfs_inode_info, vfs_inode); |
1da177e4 LT |
31 | } |
32 | ||
680b0da9 | 33 | #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) |
1da177e4 | 34 | |
fe15ce44 | 35 | static int hostfs_d_delete(const struct dentry *dentry) |
1da177e4 | 36 | { |
f1adc05e | 37 | return 1; |
1da177e4 LT |
38 | } |
39 | ||
e16404ed | 40 | static const struct dentry_operations hostfs_dentry_ops = { |
1da177e4 LT |
41 | .d_delete = hostfs_d_delete, |
42 | }; | |
43 | ||
44 | /* Changed in hostfs_args before the kernel starts running */ | |
a6eb0be6 | 45 | static char *root_ino = ""; |
1da177e4 LT |
46 | static int append = 0; |
47 | ||
48 | #define HOSTFS_SUPER_MAGIC 0x00c0ffee | |
49 | ||
92e1d5be AV |
50 | static const struct inode_operations hostfs_iops; |
51 | static const struct inode_operations hostfs_dir_iops; | |
d0352d3e | 52 | static const struct inode_operations hostfs_link_iops; |
1da177e4 LT |
53 | |
54 | #ifndef MODULE | |
55 | static int __init hostfs_args(char *options, int *add) | |
56 | { | |
57 | char *ptr; | |
58 | ||
59 | ptr = strchr(options, ','); | |
84b3db04 | 60 | if (ptr != NULL) |
1da177e4 | 61 | *ptr++ = '\0'; |
84b3db04 | 62 | if (*options != '\0') |
1da177e4 LT |
63 | root_ino = options; |
64 | ||
65 | options = ptr; | |
84b3db04 | 66 | while (options) { |
1da177e4 | 67 | ptr = strchr(options, ','); |
84b3db04 | 68 | if (ptr != NULL) |
1da177e4 | 69 | *ptr++ = '\0'; |
84b3db04 JD |
70 | if (*options != '\0') { |
71 | if (!strcmp(options, "append")) | |
1da177e4 LT |
72 | append = 1; |
73 | else printf("hostfs_args - unsupported option - %s\n", | |
74 | options); | |
75 | } | |
76 | options = ptr; | |
77 | } | |
f1adc05e | 78 | return 0; |
1da177e4 LT |
79 | } |
80 | ||
81 | __uml_setup("hostfs=", hostfs_args, | |
82 | "hostfs=<root dir>,<flags>,...\n" | |
83 | " This is used to set hostfs parameters. The root directory argument\n" | |
84 | " is used to confine all hostfs mounts to within the specified directory\n" | |
85 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
86 | " mount anything on the host that's accessible to the user that's running\n" | |
87 | " it.\n" | |
88 | " The only flag currently supported is 'append', which specifies that all\n" | |
89 | " files opened by hostfs will be opened in append mode.\n\n" | |
90 | ); | |
91 | #endif | |
92 | ||
e9193059 | 93 | static char *__dentry_name(struct dentry *dentry, char *name) |
1da177e4 | 94 | { |
ec2447c2 | 95 | char *p = dentry_path_raw(dentry, name, PATH_MAX); |
e9193059 AV |
96 | char *root; |
97 | size_t len; | |
1da177e4 | 98 | |
e9193059 AV |
99 | root = dentry->d_sb->s_fs_info; |
100 | len = strlen(root); | |
101 | if (IS_ERR(p)) { | |
102 | __putname(name); | |
f1adc05e | 103 | return NULL; |
1da177e4 | 104 | } |
850a496f | 105 | strlcpy(name, root, PATH_MAX); |
e9193059 AV |
106 | if (len > p - name) { |
107 | __putname(name); | |
108 | return NULL; | |
109 | } | |
110 | if (p > name + len) { | |
111 | char *s = name + len; | |
112 | while ((*s++ = *p++) != '\0') | |
113 | ; | |
114 | } | |
f1adc05e | 115 | return name; |
1da177e4 LT |
116 | } |
117 | ||
e9193059 AV |
118 | static char *dentry_name(struct dentry *dentry) |
119 | { | |
120 | char *name = __getname(); | |
121 | if (!name) | |
122 | return NULL; | |
123 | ||
e9193059 AV |
124 | return __dentry_name(dentry, name); /* will unlock */ |
125 | } | |
126 | ||
c5322220 | 127 | static char *inode_name(struct inode *ino) |
1da177e4 LT |
128 | { |
129 | struct dentry *dentry; | |
ec2447c2 | 130 | char *name; |
1da177e4 | 131 | |
ec2447c2 NP |
132 | dentry = d_find_alias(ino); |
133 | if (!dentry) | |
e9193059 | 134 | return NULL; |
ec2447c2 NP |
135 | |
136 | name = dentry_name(dentry); | |
137 | ||
138 | dput(dentry); | |
139 | ||
140 | return name; | |
1da177e4 LT |
141 | } |
142 | ||
1da177e4 LT |
143 | static char *follow_link(char *link) |
144 | { | |
145 | int len, n; | |
146 | char *name, *resolved, *end; | |
147 | ||
148 | len = 64; | |
84b3db04 | 149 | while (1) { |
1da177e4 LT |
150 | n = -ENOMEM; |
151 | name = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 152 | if (name == NULL) |
1da177e4 LT |
153 | goto out; |
154 | ||
ea7e743e | 155 | n = hostfs_do_readlink(link, name, len); |
84b3db04 | 156 | if (n < len) |
1da177e4 LT |
157 | break; |
158 | len *= 2; | |
159 | kfree(name); | |
160 | } | |
84b3db04 | 161 | if (n < 0) |
1da177e4 LT |
162 | goto out_free; |
163 | ||
84b3db04 | 164 | if (*name == '/') |
f1adc05e | 165 | return name; |
1da177e4 LT |
166 | |
167 | end = strrchr(link, '/'); | |
84b3db04 | 168 | if (end == NULL) |
f1adc05e | 169 | return name; |
1da177e4 LT |
170 | |
171 | *(end + 1) = '\0'; | |
172 | len = strlen(link) + strlen(name) + 1; | |
173 | ||
174 | resolved = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 175 | if (resolved == NULL) { |
1da177e4 LT |
176 | n = -ENOMEM; |
177 | goto out_free; | |
178 | } | |
179 | ||
180 | sprintf(resolved, "%s%s", link, name); | |
181 | kfree(name); | |
182 | kfree(link); | |
f1adc05e | 183 | return resolved; |
1da177e4 LT |
184 | |
185 | out_free: | |
186 | kfree(name); | |
187 | out: | |
f1adc05e | 188 | return ERR_PTR(n); |
1da177e4 LT |
189 | } |
190 | ||
0a370e5d DH |
191 | static struct inode *hostfs_iget(struct super_block *sb) |
192 | { | |
52b209f7 | 193 | struct inode *inode = new_inode(sb); |
0a370e5d DH |
194 | if (!inode) |
195 | return ERR_PTR(-ENOMEM); | |
0a370e5d DH |
196 | return inode; |
197 | } | |
198 | ||
726c3342 | 199 | int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 | 200 | { |
84b3db04 JD |
201 | /* |
202 | * do_statfs uses struct statfs64 internally, but the linux kernel | |
1da177e4 LT |
203 | * struct statfs still has 32-bit versions for most of these fields, |
204 | * so we convert them here | |
205 | */ | |
206 | int err; | |
207 | long long f_blocks; | |
208 | long long f_bfree; | |
209 | long long f_bavail; | |
210 | long long f_files; | |
211 | long long f_ffree; | |
212 | ||
601d2c38 | 213 | err = do_statfs(dentry->d_sb->s_fs_info, |
1da177e4 LT |
214 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
215 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
1b627d57 | 216 | &sf->f_namelen); |
84b3db04 | 217 | if (err) |
f1adc05e | 218 | return err; |
1da177e4 LT |
219 | sf->f_blocks = f_blocks; |
220 | sf->f_bfree = f_bfree; | |
221 | sf->f_bavail = f_bavail; | |
222 | sf->f_files = f_files; | |
223 | sf->f_ffree = f_ffree; | |
224 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
f1adc05e | 225 | return 0; |
1da177e4 LT |
226 | } |
227 | ||
228 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
229 | { | |
230 | struct hostfs_inode_info *hi; | |
231 | ||
601d2c38 | 232 | hi = kzalloc(sizeof(*hi), GFP_KERNEL); |
84b3db04 | 233 | if (hi == NULL) |
f1adc05e | 234 | return NULL; |
601d2c38 | 235 | hi->fd = -1; |
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); |
e971a6d7 | 243 | end_writeback(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 NP |
252 | struct inode *inode = container_of(head, struct inode, i_rcu); |
253 | INIT_LIST_HEAD(&inode->i_dentry); | |
1da177e4 LT |
254 | kfree(HOSTFS_I(inode)); |
255 | } | |
fa0d7e3d NP |
256 | |
257 | static void hostfs_destroy_inode(struct inode *inode) | |
258 | { | |
259 | call_rcu(&inode->i_rcu, hostfs_i_callback); | |
260 | } | |
1da177e4 | 261 | |
dd2cc4df MS |
262 | static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs) |
263 | { | |
601d2c38 | 264 | const char *root_path = vfs->mnt_sb->s_fs_info; |
dd2cc4df MS |
265 | size_t offset = strlen(root_ino) + 1; |
266 | ||
267 | if (strlen(root_path) > offset) | |
268 | seq_printf(seq, ",%s", root_path + offset); | |
269 | ||
270 | return 0; | |
271 | } | |
272 | ||
ee9b6d61 | 273 | static const struct super_operations hostfs_sbops = { |
1da177e4 | 274 | .alloc_inode = hostfs_alloc_inode, |
1da177e4 | 275 | .destroy_inode = hostfs_destroy_inode, |
e971a6d7 | 276 | .evict_inode = hostfs_evict_inode, |
1da177e4 | 277 | .statfs = hostfs_statfs, |
dd2cc4df | 278 | .show_options = hostfs_show_options, |
1da177e4 LT |
279 | }; |
280 | ||
281 | int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) | |
282 | { | |
283 | void *dir; | |
284 | char *name; | |
285 | unsigned long long next, ino; | |
286 | int error, len; | |
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; |
1da177e4 | 295 | next = file->f_pos; |
84b3db04 | 296 | while ((name = read_dir(dir, &next, &ino, &len)) != NULL) { |
1da177e4 LT |
297 | error = (*filldir)(ent, name, len, file->f_pos, |
298 | ino, DT_UNKNOWN); | |
84b3db04 | 299 | if (error) break; |
1da177e4 LT |
300 | file->f_pos = next; |
301 | } | |
302 | close_dir(dir); | |
f1adc05e | 303 | return 0; |
1da177e4 LT |
304 | } |
305 | ||
306 | int hostfs_file_open(struct inode *ino, struct file *file) | |
307 | { | |
f8ad850f | 308 | static DEFINE_MUTEX(open_mutex); |
1da177e4 | 309 | char *name; |
aeb5d727 | 310 | fmode_t mode = 0; |
f8ad850f | 311 | int err; |
aeb5d727 | 312 | int r = 0, w = 0, fd; |
1da177e4 LT |
313 | |
314 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 315 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 316 | return 0; |
1da177e4 | 317 | |
f8ad850f | 318 | mode |= HOSTFS_I(ino)->mode; |
1da177e4 | 319 | |
f8ad850f AV |
320 | retry: |
321 | if (mode & FMODE_READ) | |
1da177e4 | 322 | r = 1; |
f8ad850f | 323 | if (mode & FMODE_WRITE) |
1da177e4 | 324 | w = 1; |
84b3db04 | 325 | if (w) |
1da177e4 LT |
326 | r = 1; |
327 | ||
c5322220 | 328 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 329 | if (name == NULL) |
f1adc05e | 330 | return -ENOMEM; |
1da177e4 LT |
331 | |
332 | fd = open_file(name, r, w, append); | |
e9193059 | 333 | __putname(name); |
84b3db04 | 334 | if (fd < 0) |
f1adc05e | 335 | return fd; |
f8ad850f AV |
336 | |
337 | mutex_lock(&open_mutex); | |
338 | /* somebody else had handled it first? */ | |
339 | if ((mode & HOSTFS_I(ino)->mode) == mode) { | |
340 | mutex_unlock(&open_mutex); | |
341 | return 0; | |
342 | } | |
343 | if ((mode | HOSTFS_I(ino)->mode) != mode) { | |
344 | mode |= HOSTFS_I(ino)->mode; | |
345 | mutex_unlock(&open_mutex); | |
346 | close_file(&fd); | |
347 | goto retry; | |
348 | } | |
349 | if (HOSTFS_I(ino)->fd == -1) { | |
350 | HOSTFS_I(ino)->fd = fd; | |
351 | } else { | |
352 | err = replace_file(fd, HOSTFS_I(ino)->fd); | |
353 | close_file(&fd); | |
354 | if (err < 0) { | |
355 | mutex_unlock(&open_mutex); | |
356 | return err; | |
357 | } | |
358 | } | |
359 | HOSTFS_I(ino)->mode = mode; | |
360 | mutex_unlock(&open_mutex); | |
1da177e4 | 361 | |
f1adc05e | 362 | return 0; |
1da177e4 LT |
363 | } |
364 | ||
7ea80859 | 365 | int hostfs_fsync(struct file *file, int datasync) |
1da177e4 | 366 | { |
7ea80859 | 367 | return fsync_file(HOSTFS_I(file->f_mapping->host)->fd, datasync); |
1da177e4 LT |
368 | } |
369 | ||
4b6f5d20 | 370 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 371 | .llseek = generic_file_llseek, |
543ade1f | 372 | .read = do_sync_read, |
5ffc4ef4 | 373 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
374 | .aio_read = generic_file_aio_read, |
375 | .aio_write = generic_file_aio_write, | |
543ade1f | 376 | .write = do_sync_write, |
1da177e4 LT |
377 | .mmap = generic_file_mmap, |
378 | .open = hostfs_file_open, | |
379 | .release = NULL, | |
380 | .fsync = hostfs_fsync, | |
381 | }; | |
382 | ||
4b6f5d20 | 383 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
384 | .llseek = generic_file_llseek, |
385 | .readdir = hostfs_readdir, | |
386 | .read = generic_read_dir, | |
387 | }; | |
388 | ||
389 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
390 | { | |
391 | struct address_space *mapping = page->mapping; | |
392 | struct inode *inode = mapping->host; | |
393 | char *buffer; | |
394 | unsigned long long base; | |
395 | int count = PAGE_CACHE_SIZE; | |
396 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
397 | int err; | |
398 | ||
399 | if (page->index >= end_index) | |
400 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
401 | ||
402 | buffer = kmap(page); | |
403 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
404 | ||
405 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 406 | if (err != count) { |
1da177e4 LT |
407 | ClearPageUptodate(page); |
408 | goto out; | |
409 | } | |
410 | ||
411 | if (base > inode->i_size) | |
412 | inode->i_size = base; | |
413 | ||
414 | if (PageError(page)) | |
415 | ClearPageError(page); | |
416 | err = 0; | |
417 | ||
418 | out: | |
419 | kunmap(page); | |
420 | ||
421 | unlock_page(page); | |
422 | return err; | |
423 | } | |
424 | ||
425 | int hostfs_readpage(struct file *file, struct page *page) | |
426 | { | |
427 | char *buffer; | |
428 | long long start; | |
429 | int err = 0; | |
430 | ||
431 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
432 | buffer = kmap(page); | |
433 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
434 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
435 | if (err < 0) |
436 | goto out; | |
1da177e4 LT |
437 | |
438 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
439 | ||
440 | flush_dcache_page(page); | |
441 | SetPageUptodate(page); | |
442 | if (PageError(page)) ClearPageError(page); | |
443 | err = 0; | |
444 | out: | |
445 | kunmap(page); | |
446 | unlock_page(page); | |
f1adc05e | 447 | return err; |
1da177e4 LT |
448 | } |
449 | ||
ae361ff4 NP |
450 | int hostfs_write_begin(struct file *file, struct address_space *mapping, |
451 | loff_t pos, unsigned len, unsigned flags, | |
452 | struct page **pagep, void **fsdata) | |
1da177e4 | 453 | { |
ae361ff4 | 454 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 455 | |
54566b2c | 456 | *pagep = grab_cache_page_write_begin(mapping, index, flags); |
ae361ff4 NP |
457 | if (!*pagep) |
458 | return -ENOMEM; | |
459 | return 0; | |
1da177e4 LT |
460 | } |
461 | ||
ae361ff4 NP |
462 | int hostfs_write_end(struct file *file, struct address_space *mapping, |
463 | loff_t pos, unsigned len, unsigned copied, | |
464 | struct page *page, void *fsdata) | |
1da177e4 | 465 | { |
1da177e4 | 466 | struct inode *inode = mapping->host; |
ae361ff4 NP |
467 | void *buffer; |
468 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
469 | int err; | |
1da177e4 | 470 | |
1da177e4 | 471 | buffer = kmap(page); |
ae361ff4 NP |
472 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
473 | kunmap(page); | |
30f04a4e | 474 | |
ae361ff4 NP |
475 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
476 | SetPageUptodate(page); | |
30f04a4e | 477 | |
84b3db04 JD |
478 | /* |
479 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
480 | * i_size against the last byte written. |
481 | */ | |
482 | if (err > 0 && (pos > inode->i_size)) | |
483 | inode->i_size = pos; | |
484 | unlock_page(page); | |
485 | page_cache_release(page); | |
1da177e4 | 486 | |
f1adc05e | 487 | return err; |
1da177e4 LT |
488 | } |
489 | ||
f5e54d6e | 490 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
491 | .writepage = hostfs_writepage, |
492 | .readpage = hostfs_readpage, | |
ffa0aea6 | 493 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
494 | .write_begin = hostfs_write_begin, |
495 | .write_end = hostfs_write_end, | |
1da177e4 LT |
496 | }; |
497 | ||
4754b825 | 498 | static int read_name(struct inode *ino, char *name) |
1da177e4 | 499 | { |
4754b825 AV |
500 | dev_t rdev; |
501 | struct hostfs_stat st; | |
502 | int err = stat_file(name, &st, -1); | |
503 | if (err) | |
504 | return err; | |
1da177e4 | 505 | |
5e2df28c | 506 | /* Reencode maj and min with the kernel encoding.*/ |
4754b825 | 507 | rdev = MKDEV(st.maj, st.min); |
1da177e4 | 508 | |
4754b825 AV |
509 | switch (st.mode & S_IFMT) { |
510 | case S_IFLNK: | |
d0352d3e | 511 | ino->i_op = &hostfs_link_iops; |
1da177e4 | 512 | break; |
4754b825 AV |
513 | case S_IFDIR: |
514 | ino->i_op = &hostfs_dir_iops; | |
515 | ino->i_fop = &hostfs_dir_fops; | |
1da177e4 | 516 | break; |
4754b825 AV |
517 | case S_IFCHR: |
518 | case S_IFBLK: | |
519 | case S_IFIFO: | |
520 | case S_IFSOCK: | |
521 | init_special_inode(ino, st.mode & S_IFMT, rdev); | |
522 | ino->i_op = &hostfs_iops; | |
1da177e4 | 523 | break; |
4754b825 AV |
524 | |
525 | default: | |
526 | ino->i_op = &hostfs_iops; | |
527 | ino->i_fop = &hostfs_file_fops; | |
528 | ino->i_mapping->a_ops = &hostfs_aops; | |
1da177e4 | 529 | } |
4754b825 AV |
530 | |
531 | ino->i_ino = st.ino; | |
532 | ino->i_mode = st.mode; | |
533 | ino->i_nlink = st.nlink; | |
534 | ino->i_uid = st.uid; | |
535 | ino->i_gid = st.gid; | |
536 | ino->i_atime = st.atime; | |
537 | ino->i_mtime = st.mtime; | |
538 | ino->i_ctime = st.ctime; | |
539 | ino->i_size = st.size; | |
540 | ino->i_blocks = st.blocks; | |
541 | return 0; | |
1da177e4 LT |
542 | } |
543 | ||
544 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
84b3db04 | 545 | struct nameidata *nd) |
1da177e4 LT |
546 | { |
547 | struct inode *inode; | |
548 | char *name; | |
549 | int error, fd; | |
550 | ||
0a370e5d DH |
551 | inode = hostfs_iget(dir->i_sb); |
552 | if (IS_ERR(inode)) { | |
553 | error = PTR_ERR(inode); | |
84b3db04 | 554 | goto out; |
0a370e5d | 555 | } |
1da177e4 | 556 | |
1da177e4 | 557 | error = -ENOMEM; |
c5322220 | 558 | name = dentry_name(dentry); |
84b3db04 | 559 | if (name == NULL) |
1da177e4 LT |
560 | goto out_put; |
561 | ||
562 | fd = file_create(name, | |
563 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
564 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
565 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
4754b825 | 566 | if (fd < 0) |
1da177e4 | 567 | error = fd; |
4754b825 | 568 | else |
5e2df28c | 569 | error = read_name(inode, name); |
1da177e4 | 570 | |
e9193059 | 571 | __putname(name); |
84b3db04 | 572 | if (error) |
1da177e4 LT |
573 | goto out_put; |
574 | ||
575 | HOSTFS_I(inode)->fd = fd; | |
576 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
577 | d_instantiate(dentry, inode); | |
f1adc05e | 578 | return 0; |
1da177e4 LT |
579 | |
580 | out_put: | |
581 | iput(inode); | |
582 | out: | |
f1adc05e | 583 | return error; |
1da177e4 LT |
584 | } |
585 | ||
586 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
f1adc05e | 587 | struct nameidata *nd) |
1da177e4 LT |
588 | { |
589 | struct inode *inode; | |
590 | char *name; | |
591 | int err; | |
592 | ||
0a370e5d DH |
593 | inode = hostfs_iget(ino->i_sb); |
594 | if (IS_ERR(inode)) { | |
595 | err = PTR_ERR(inode); | |
1da177e4 | 596 | goto out; |
0a370e5d | 597 | } |
1da177e4 | 598 | |
1da177e4 | 599 | err = -ENOMEM; |
c5322220 | 600 | name = dentry_name(dentry); |
84b3db04 | 601 | if (name == NULL) |
1da177e4 LT |
602 | goto out_put; |
603 | ||
604 | err = read_name(inode, name); | |
5e2df28c | 605 | |
e9193059 | 606 | __putname(name); |
84b3db04 | 607 | if (err == -ENOENT) { |
1da177e4 LT |
608 | iput(inode); |
609 | inode = NULL; | |
610 | } | |
84b3db04 | 611 | else if (err) |
1da177e4 LT |
612 | goto out_put; |
613 | ||
614 | d_add(dentry, inode); | |
f1adc05e | 615 | return NULL; |
1da177e4 LT |
616 | |
617 | out_put: | |
618 | iput(inode); | |
619 | out: | |
f1adc05e | 620 | return ERR_PTR(err); |
1da177e4 LT |
621 | } |
622 | ||
1da177e4 LT |
623 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) |
624 | { | |
f1adc05e JD |
625 | char *from_name, *to_name; |
626 | int err; | |
1da177e4 | 627 | |
c5322220 | 628 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 629 | return -ENOMEM; |
c5322220 | 630 | to_name = dentry_name(to); |
84b3db04 | 631 | if (to_name == NULL) { |
e9193059 | 632 | __putname(from_name); |
f1adc05e | 633 | return -ENOMEM; |
1da177e4 | 634 | } |
f1adc05e | 635 | err = link_file(to_name, from_name); |
e9193059 AV |
636 | __putname(from_name); |
637 | __putname(to_name); | |
f1adc05e | 638 | return err; |
1da177e4 LT |
639 | } |
640 | ||
641 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
642 | { | |
643 | char *file; | |
644 | int err; | |
645 | ||
84b3db04 | 646 | if (append) |
f1adc05e | 647 | return -EPERM; |
1da177e4 | 648 | |
f8d7e187 AV |
649 | if ((file = dentry_name(dentry)) == NULL) |
650 | return -ENOMEM; | |
651 | ||
1da177e4 | 652 | err = unlink_file(file); |
e9193059 | 653 | __putname(file); |
f1adc05e | 654 | return err; |
1da177e4 LT |
655 | } |
656 | ||
657 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
658 | { | |
659 | char *file; | |
660 | int err; | |
661 | ||
c5322220 | 662 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 663 | return -ENOMEM; |
1da177e4 | 664 | err = make_symlink(file, to); |
e9193059 | 665 | __putname(file); |
f1adc05e | 666 | return err; |
1da177e4 LT |
667 | } |
668 | ||
669 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
670 | { | |
671 | char *file; | |
672 | int err; | |
673 | ||
c5322220 | 674 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 675 | return -ENOMEM; |
1da177e4 | 676 | err = do_mkdir(file, mode); |
e9193059 | 677 | __putname(file); |
f1adc05e | 678 | return err; |
1da177e4 LT |
679 | } |
680 | ||
681 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
682 | { | |
683 | char *file; | |
684 | int err; | |
685 | ||
79bf7c73 SW |
686 | dentry_unhash(dentry); |
687 | ||
c5322220 | 688 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 689 | return -ENOMEM; |
1da177e4 | 690 | err = do_rmdir(file); |
e9193059 | 691 | __putname(file); |
f1adc05e | 692 | return err; |
1da177e4 LT |
693 | } |
694 | ||
695 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
696 | { | |
697 | struct inode *inode; | |
698 | char *name; | |
0a370e5d | 699 | int err; |
1da177e4 | 700 | |
0a370e5d DH |
701 | inode = hostfs_iget(dir->i_sb); |
702 | if (IS_ERR(inode)) { | |
703 | err = PTR_ERR(inode); | |
1da177e4 | 704 | goto out; |
0a370e5d | 705 | } |
1da177e4 | 706 | |
1da177e4 | 707 | err = -ENOMEM; |
c5322220 | 708 | name = dentry_name(dentry); |
84b3db04 | 709 | if (name == NULL) |
1da177e4 LT |
710 | goto out_put; |
711 | ||
712 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 713 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
e9193059 | 714 | if (!err) |
1da177e4 LT |
715 | goto out_free; |
716 | ||
717 | err = read_name(inode, name); | |
e9193059 | 718 | __putname(name); |
5e2df28c AV |
719 | if (err) |
720 | goto out_put; | |
84b3db04 | 721 | if (err) |
1da177e4 LT |
722 | goto out_put; |
723 | ||
724 | d_instantiate(dentry, inode); | |
f1adc05e | 725 | return 0; |
1da177e4 LT |
726 | |
727 | out_free: | |
e9193059 | 728 | __putname(name); |
1da177e4 LT |
729 | out_put: |
730 | iput(inode); | |
731 | out: | |
f1adc05e | 732 | return err; |
1da177e4 LT |
733 | } |
734 | ||
735 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
736 | struct inode *to_ino, struct dentry *to) | |
737 | { | |
738 | char *from_name, *to_name; | |
739 | int err; | |
740 | ||
e4eaac06 SW |
741 | if (to->d_inode && S_ISDIR(to->d_inode->i_mode)) |
742 | dentry_unhash(to); | |
743 | ||
c5322220 | 744 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 745 | return -ENOMEM; |
c5322220 | 746 | if ((to_name = dentry_name(to)) == NULL) { |
e9193059 | 747 | __putname(from_name); |
f1adc05e | 748 | return -ENOMEM; |
1da177e4 LT |
749 | } |
750 | err = rename_file(from_name, to_name); | |
e9193059 AV |
751 | __putname(from_name); |
752 | __putname(to_name); | |
f1adc05e | 753 | return err; |
1da177e4 LT |
754 | } |
755 | ||
b74c79e9 | 756 | int hostfs_permission(struct inode *ino, int desired, unsigned int flags) |
1da177e4 LT |
757 | { |
758 | char *name; | |
759 | int r = 0, w = 0, x = 0, err; | |
760 | ||
b74c79e9 NP |
761 | if (flags & IPERM_FLAG_RCU) |
762 | return -ECHILD; | |
763 | ||
1da177e4 LT |
764 | if (desired & MAY_READ) r = 1; |
765 | if (desired & MAY_WRITE) w = 1; | |
766 | if (desired & MAY_EXEC) x = 1; | |
c5322220 | 767 | name = inode_name(ino); |
f1adc05e JD |
768 | if (name == NULL) |
769 | return -ENOMEM; | |
1da177e4 LT |
770 | |
771 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 772 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
773 | err = 0; |
774 | else | |
775 | err = access_file(name, r, w, x); | |
e9193059 | 776 | __putname(name); |
84b3db04 | 777 | if (!err) |
b74c79e9 | 778 | err = generic_permission(ino, desired, flags, NULL); |
1da177e4 LT |
779 | return err; |
780 | } | |
781 | ||
782 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
783 | { | |
1025774c | 784 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
785 | struct hostfs_iattr attrs; |
786 | char *name; | |
787 | int err; | |
788 | ||
1025774c | 789 | int fd = HOSTFS_I(inode)->fd; |
5822b7fa | 790 | |
1025774c | 791 | err = inode_change_ok(inode, attr); |
1da177e4 LT |
792 | if (err) |
793 | return err; | |
794 | ||
84b3db04 | 795 | if (append) |
1da177e4 LT |
796 | attr->ia_valid &= ~ATTR_SIZE; |
797 | ||
798 | attrs.ia_valid = 0; | |
84b3db04 | 799 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
800 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
801 | attrs.ia_mode = attr->ia_mode; | |
802 | } | |
84b3db04 | 803 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 LT |
804 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
805 | attrs.ia_uid = attr->ia_uid; | |
806 | } | |
84b3db04 | 807 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 LT |
808 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
809 | attrs.ia_gid = attr->ia_gid; | |
810 | } | |
84b3db04 | 811 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
812 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
813 | attrs.ia_size = attr->ia_size; | |
814 | } | |
84b3db04 | 815 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
816 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
817 | attrs.ia_atime = attr->ia_atime; | |
818 | } | |
84b3db04 | 819 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
820 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
821 | attrs.ia_mtime = attr->ia_mtime; | |
822 | } | |
84b3db04 | 823 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
824 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
825 | attrs.ia_ctime = attr->ia_ctime; | |
826 | } | |
84b3db04 | 827 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
828 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
829 | } | |
84b3db04 | 830 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
831 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
832 | } | |
c5322220 | 833 | name = dentry_name(dentry); |
84b3db04 | 834 | if (name == NULL) |
f1adc05e | 835 | return -ENOMEM; |
5822b7fa | 836 | err = set_attr(name, &attrs, fd); |
e9193059 | 837 | __putname(name); |
84b3db04 | 838 | if (err) |
f1adc05e | 839 | return err; |
1da177e4 | 840 | |
1025774c CH |
841 | if ((attr->ia_valid & ATTR_SIZE) && |
842 | attr->ia_size != i_size_read(inode)) { | |
843 | int error; | |
844 | ||
845 | error = vmtruncate(inode, attr->ia_size); | |
846 | if (err) | |
847 | return err; | |
848 | } | |
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 | .create = hostfs_create, |
857 | .link = hostfs_link, | |
858 | .unlink = hostfs_unlink, | |
859 | .symlink = hostfs_symlink, | |
860 | .mkdir = hostfs_mkdir, | |
861 | .rmdir = hostfs_rmdir, | |
862 | .mknod = hostfs_mknod, | |
863 | .rename = hostfs_rename, | |
1da177e4 LT |
864 | .permission = hostfs_permission, |
865 | .setattr = hostfs_setattr, | |
1da177e4 LT |
866 | }; |
867 | ||
92e1d5be | 868 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
869 | .create = hostfs_create, |
870 | .lookup = hostfs_lookup, | |
871 | .link = hostfs_link, | |
872 | .unlink = hostfs_unlink, | |
873 | .symlink = hostfs_symlink, | |
874 | .mkdir = hostfs_mkdir, | |
875 | .rmdir = hostfs_rmdir, | |
876 | .mknod = hostfs_mknod, | |
877 | .rename = hostfs_rename, | |
1da177e4 LT |
878 | .permission = hostfs_permission, |
879 | .setattr = hostfs_setattr, | |
1da177e4 LT |
880 | }; |
881 | ||
d0352d3e AV |
882 | static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
883 | { | |
884 | char *link = __getname(); | |
885 | if (link) { | |
886 | char *path = dentry_name(dentry); | |
887 | int err = -ENOMEM; | |
888 | if (path) { | |
3b6036d1 | 889 | err = hostfs_do_readlink(path, link, PATH_MAX); |
d0352d3e AV |
890 | if (err == PATH_MAX) |
891 | err = -E2BIG; | |
e9193059 | 892 | __putname(path); |
d0352d3e AV |
893 | } |
894 | if (err < 0) { | |
895 | __putname(link); | |
896 | link = ERR_PTR(err); | |
897 | } | |
898 | } else { | |
899 | link = ERR_PTR(-ENOMEM); | |
1da177e4 | 900 | } |
d0352d3e AV |
901 | |
902 | nd_set_link(nd, link); | |
903 | return NULL; | |
904 | } | |
905 | ||
906 | static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) | |
907 | { | |
908 | char *s = nd_get_link(nd); | |
909 | if (!IS_ERR(s)) | |
910 | __putname(s); | |
1da177e4 LT |
911 | } |
912 | ||
d0352d3e AV |
913 | static const struct inode_operations hostfs_link_iops = { |
914 | .readlink = generic_readlink, | |
915 | .follow_link = hostfs_follow_link, | |
916 | .put_link = hostfs_put_link, | |
1da177e4 LT |
917 | }; |
918 | ||
919 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
920 | { | |
921 | struct inode *root_inode; | |
75e8defb | 922 | char *host_root_path, *req_root = d; |
1da177e4 LT |
923 | int err; |
924 | ||
925 | sb->s_blocksize = 1024; | |
926 | sb->s_blocksize_bits = 10; | |
927 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
928 | sb->s_op = &hostfs_sbops; | |
f772c4a6 | 929 | sb->s_d_op = &hostfs_dentry_ops; |
752fa51e | 930 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
1da177e4 | 931 | |
a6eb0be6 | 932 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
933 | if (req_root == NULL) |
934 | req_root = ""; | |
1da177e4 LT |
935 | |
936 | err = -ENOMEM; | |
601d2c38 AV |
937 | sb->s_fs_info = host_root_path = |
938 | kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); | |
84b3db04 | 939 | if (host_root_path == NULL) |
1da177e4 LT |
940 | goto out; |
941 | ||
75e8defb | 942 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 | 943 | |
52b209f7 AV |
944 | root_inode = new_inode(sb); |
945 | if (!root_inode) | |
601d2c38 | 946 | goto out; |
1da177e4 | 947 | |
4754b825 AV |
948 | err = read_name(root_inode, host_root_path); |
949 | if (err) | |
950 | goto out_put; | |
52b209f7 | 951 | |
4754b825 | 952 | if (S_ISLNK(root_inode->i_mode)) { |
52b209f7 AV |
953 | char *name = follow_link(host_root_path); |
954 | if (IS_ERR(name)) | |
955 | err = PTR_ERR(name); | |
956 | else | |
957 | err = read_name(root_inode, name); | |
958 | kfree(name); | |
4754b825 AV |
959 | if (err) |
960 | goto out_put; | |
52b209f7 | 961 | } |
1da177e4 | 962 | |
1da177e4 LT |
963 | err = -ENOMEM; |
964 | sb->s_root = d_alloc_root(root_inode); | |
84b3db04 | 965 | if (sb->s_root == NULL) |
1da177e4 LT |
966 | goto out_put; |
967 | ||
f1adc05e | 968 | return 0; |
1da177e4 | 969 | |
f1adc05e JD |
970 | out_put: |
971 | iput(root_inode); | |
f1adc05e JD |
972 | out: |
973 | return err; | |
1da177e4 LT |
974 | } |
975 | ||
3c26ff6e | 976 | static struct dentry *hostfs_read_sb(struct file_system_type *type, |
454e2398 | 977 | int flags, const char *dev_name, |
3c26ff6e | 978 | void *data) |
1da177e4 | 979 | { |
3c26ff6e | 980 | return mount_nodev(type, flags, data, hostfs_fill_sb_common); |
1da177e4 LT |
981 | } |
982 | ||
601d2c38 AV |
983 | static void hostfs_kill_sb(struct super_block *s) |
984 | { | |
985 | kill_anon_super(s); | |
986 | kfree(s->s_fs_info); | |
987 | } | |
988 | ||
1da177e4 LT |
989 | static struct file_system_type hostfs_type = { |
990 | .owner = THIS_MODULE, | |
991 | .name = "hostfs", | |
3c26ff6e | 992 | .mount = hostfs_read_sb, |
601d2c38 | 993 | .kill_sb = hostfs_kill_sb, |
1da177e4 LT |
994 | .fs_flags = 0, |
995 | }; | |
996 | ||
997 | static int __init init_hostfs(void) | |
998 | { | |
f1adc05e | 999 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
1000 | } |
1001 | ||
1002 | static void __exit exit_hostfs(void) | |
1003 | { | |
1004 | unregister_filesystem(&hostfs_type); | |
1005 | } | |
1006 | ||
1007 | module_init(init_hostfs) | |
1008 | module_exit(exit_hostfs) | |
1009 | MODULE_LICENSE("GPL"); |