]>
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> |
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 | ||
250 | static void hostfs_destroy_inode(struct inode *inode) | |
251 | { | |
1da177e4 LT |
252 | kfree(HOSTFS_I(inode)); |
253 | } | |
254 | ||
dd2cc4df MS |
255 | static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs) |
256 | { | |
601d2c38 | 257 | const char *root_path = vfs->mnt_sb->s_fs_info; |
dd2cc4df MS |
258 | size_t offset = strlen(root_ino) + 1; |
259 | ||
260 | if (strlen(root_path) > offset) | |
261 | seq_printf(seq, ",%s", root_path + offset); | |
262 | ||
263 | return 0; | |
264 | } | |
265 | ||
ee9b6d61 | 266 | static const struct super_operations hostfs_sbops = { |
1da177e4 | 267 | .alloc_inode = hostfs_alloc_inode, |
1da177e4 | 268 | .destroy_inode = hostfs_destroy_inode, |
e971a6d7 | 269 | .evict_inode = hostfs_evict_inode, |
1da177e4 | 270 | .statfs = hostfs_statfs, |
dd2cc4df | 271 | .show_options = hostfs_show_options, |
1da177e4 LT |
272 | }; |
273 | ||
274 | int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) | |
275 | { | |
276 | void *dir; | |
277 | char *name; | |
278 | unsigned long long next, ino; | |
279 | int error, len; | |
280 | ||
c5322220 | 281 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 282 | if (name == NULL) |
f1adc05e | 283 | return -ENOMEM; |
1da177e4 | 284 | dir = open_dir(name, &error); |
e9193059 | 285 | __putname(name); |
84b3db04 | 286 | if (dir == NULL) |
f1adc05e | 287 | return -error; |
1da177e4 | 288 | next = file->f_pos; |
84b3db04 | 289 | while ((name = read_dir(dir, &next, &ino, &len)) != NULL) { |
1da177e4 LT |
290 | error = (*filldir)(ent, name, len, file->f_pos, |
291 | ino, DT_UNKNOWN); | |
84b3db04 | 292 | if (error) break; |
1da177e4 LT |
293 | file->f_pos = next; |
294 | } | |
295 | close_dir(dir); | |
f1adc05e | 296 | return 0; |
1da177e4 LT |
297 | } |
298 | ||
299 | int hostfs_file_open(struct inode *ino, struct file *file) | |
300 | { | |
f8ad850f | 301 | static DEFINE_MUTEX(open_mutex); |
1da177e4 | 302 | char *name; |
aeb5d727 | 303 | fmode_t mode = 0; |
f8ad850f | 304 | int err; |
aeb5d727 | 305 | int r = 0, w = 0, fd; |
1da177e4 LT |
306 | |
307 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 308 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 309 | return 0; |
1da177e4 | 310 | |
f8ad850f | 311 | mode |= HOSTFS_I(ino)->mode; |
1da177e4 | 312 | |
f8ad850f AV |
313 | retry: |
314 | if (mode & FMODE_READ) | |
1da177e4 | 315 | r = 1; |
f8ad850f | 316 | if (mode & FMODE_WRITE) |
1da177e4 | 317 | w = 1; |
84b3db04 | 318 | if (w) |
1da177e4 LT |
319 | r = 1; |
320 | ||
c5322220 | 321 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 322 | if (name == NULL) |
f1adc05e | 323 | return -ENOMEM; |
1da177e4 LT |
324 | |
325 | fd = open_file(name, r, w, append); | |
e9193059 | 326 | __putname(name); |
84b3db04 | 327 | if (fd < 0) |
f1adc05e | 328 | return fd; |
f8ad850f AV |
329 | |
330 | mutex_lock(&open_mutex); | |
331 | /* somebody else had handled it first? */ | |
332 | if ((mode & HOSTFS_I(ino)->mode) == mode) { | |
333 | mutex_unlock(&open_mutex); | |
334 | return 0; | |
335 | } | |
336 | if ((mode | HOSTFS_I(ino)->mode) != mode) { | |
337 | mode |= HOSTFS_I(ino)->mode; | |
338 | mutex_unlock(&open_mutex); | |
339 | close_file(&fd); | |
340 | goto retry; | |
341 | } | |
342 | if (HOSTFS_I(ino)->fd == -1) { | |
343 | HOSTFS_I(ino)->fd = fd; | |
344 | } else { | |
345 | err = replace_file(fd, HOSTFS_I(ino)->fd); | |
346 | close_file(&fd); | |
347 | if (err < 0) { | |
348 | mutex_unlock(&open_mutex); | |
349 | return err; | |
350 | } | |
351 | } | |
352 | HOSTFS_I(ino)->mode = mode; | |
353 | mutex_unlock(&open_mutex); | |
1da177e4 | 354 | |
f1adc05e | 355 | return 0; |
1da177e4 LT |
356 | } |
357 | ||
7ea80859 | 358 | int hostfs_fsync(struct file *file, int datasync) |
1da177e4 | 359 | { |
7ea80859 | 360 | return fsync_file(HOSTFS_I(file->f_mapping->host)->fd, datasync); |
1da177e4 LT |
361 | } |
362 | ||
4b6f5d20 | 363 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 364 | .llseek = generic_file_llseek, |
543ade1f | 365 | .read = do_sync_read, |
5ffc4ef4 | 366 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
367 | .aio_read = generic_file_aio_read, |
368 | .aio_write = generic_file_aio_write, | |
543ade1f | 369 | .write = do_sync_write, |
1da177e4 LT |
370 | .mmap = generic_file_mmap, |
371 | .open = hostfs_file_open, | |
372 | .release = NULL, | |
373 | .fsync = hostfs_fsync, | |
374 | }; | |
375 | ||
4b6f5d20 | 376 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
377 | .llseek = generic_file_llseek, |
378 | .readdir = hostfs_readdir, | |
379 | .read = generic_read_dir, | |
380 | }; | |
381 | ||
382 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
383 | { | |
384 | struct address_space *mapping = page->mapping; | |
385 | struct inode *inode = mapping->host; | |
386 | char *buffer; | |
387 | unsigned long long base; | |
388 | int count = PAGE_CACHE_SIZE; | |
389 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
390 | int err; | |
391 | ||
392 | if (page->index >= end_index) | |
393 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
394 | ||
395 | buffer = kmap(page); | |
396 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
397 | ||
398 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 399 | if (err != count) { |
1da177e4 LT |
400 | ClearPageUptodate(page); |
401 | goto out; | |
402 | } | |
403 | ||
404 | if (base > inode->i_size) | |
405 | inode->i_size = base; | |
406 | ||
407 | if (PageError(page)) | |
408 | ClearPageError(page); | |
409 | err = 0; | |
410 | ||
411 | out: | |
412 | kunmap(page); | |
413 | ||
414 | unlock_page(page); | |
415 | return err; | |
416 | } | |
417 | ||
418 | int hostfs_readpage(struct file *file, struct page *page) | |
419 | { | |
420 | char *buffer; | |
421 | long long start; | |
422 | int err = 0; | |
423 | ||
424 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
425 | buffer = kmap(page); | |
426 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
427 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
428 | if (err < 0) |
429 | goto out; | |
1da177e4 LT |
430 | |
431 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
432 | ||
433 | flush_dcache_page(page); | |
434 | SetPageUptodate(page); | |
435 | if (PageError(page)) ClearPageError(page); | |
436 | err = 0; | |
437 | out: | |
438 | kunmap(page); | |
439 | unlock_page(page); | |
f1adc05e | 440 | return err; |
1da177e4 LT |
441 | } |
442 | ||
ae361ff4 NP |
443 | int hostfs_write_begin(struct file *file, struct address_space *mapping, |
444 | loff_t pos, unsigned len, unsigned flags, | |
445 | struct page **pagep, void **fsdata) | |
1da177e4 | 446 | { |
ae361ff4 | 447 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 448 | |
54566b2c | 449 | *pagep = grab_cache_page_write_begin(mapping, index, flags); |
ae361ff4 NP |
450 | if (!*pagep) |
451 | return -ENOMEM; | |
452 | return 0; | |
1da177e4 LT |
453 | } |
454 | ||
ae361ff4 NP |
455 | int hostfs_write_end(struct file *file, struct address_space *mapping, |
456 | loff_t pos, unsigned len, unsigned copied, | |
457 | struct page *page, void *fsdata) | |
1da177e4 | 458 | { |
1da177e4 | 459 | struct inode *inode = mapping->host; |
ae361ff4 NP |
460 | void *buffer; |
461 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
462 | int err; | |
1da177e4 | 463 | |
1da177e4 | 464 | buffer = kmap(page); |
ae361ff4 NP |
465 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
466 | kunmap(page); | |
30f04a4e | 467 | |
ae361ff4 NP |
468 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
469 | SetPageUptodate(page); | |
30f04a4e | 470 | |
84b3db04 JD |
471 | /* |
472 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
473 | * i_size against the last byte written. |
474 | */ | |
475 | if (err > 0 && (pos > inode->i_size)) | |
476 | inode->i_size = pos; | |
477 | unlock_page(page); | |
478 | page_cache_release(page); | |
1da177e4 | 479 | |
f1adc05e | 480 | return err; |
1da177e4 LT |
481 | } |
482 | ||
f5e54d6e | 483 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
484 | .writepage = hostfs_writepage, |
485 | .readpage = hostfs_readpage, | |
ffa0aea6 | 486 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
487 | .write_begin = hostfs_write_begin, |
488 | .write_end = hostfs_write_end, | |
1da177e4 LT |
489 | }; |
490 | ||
4754b825 | 491 | static int read_name(struct inode *ino, char *name) |
1da177e4 | 492 | { |
4754b825 AV |
493 | dev_t rdev; |
494 | struct hostfs_stat st; | |
495 | int err = stat_file(name, &st, -1); | |
496 | if (err) | |
497 | return err; | |
1da177e4 | 498 | |
5e2df28c | 499 | /* Reencode maj and min with the kernel encoding.*/ |
4754b825 | 500 | rdev = MKDEV(st.maj, st.min); |
1da177e4 | 501 | |
4754b825 AV |
502 | switch (st.mode & S_IFMT) { |
503 | case S_IFLNK: | |
d0352d3e | 504 | ino->i_op = &hostfs_link_iops; |
1da177e4 | 505 | break; |
4754b825 AV |
506 | case S_IFDIR: |
507 | ino->i_op = &hostfs_dir_iops; | |
508 | ino->i_fop = &hostfs_dir_fops; | |
1da177e4 | 509 | break; |
4754b825 AV |
510 | case S_IFCHR: |
511 | case S_IFBLK: | |
512 | case S_IFIFO: | |
513 | case S_IFSOCK: | |
514 | init_special_inode(ino, st.mode & S_IFMT, rdev); | |
515 | ino->i_op = &hostfs_iops; | |
1da177e4 | 516 | break; |
4754b825 AV |
517 | |
518 | default: | |
519 | ino->i_op = &hostfs_iops; | |
520 | ino->i_fop = &hostfs_file_fops; | |
521 | ino->i_mapping->a_ops = &hostfs_aops; | |
1da177e4 | 522 | } |
4754b825 AV |
523 | |
524 | ino->i_ino = st.ino; | |
525 | ino->i_mode = st.mode; | |
526 | ino->i_nlink = st.nlink; | |
527 | ino->i_uid = st.uid; | |
528 | ino->i_gid = st.gid; | |
529 | ino->i_atime = st.atime; | |
530 | ino->i_mtime = st.mtime; | |
531 | ino->i_ctime = st.ctime; | |
532 | ino->i_size = st.size; | |
533 | ino->i_blocks = st.blocks; | |
534 | return 0; | |
1da177e4 LT |
535 | } |
536 | ||
537 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
84b3db04 | 538 | struct nameidata *nd) |
1da177e4 LT |
539 | { |
540 | struct inode *inode; | |
541 | char *name; | |
542 | int error, fd; | |
543 | ||
0a370e5d DH |
544 | inode = hostfs_iget(dir->i_sb); |
545 | if (IS_ERR(inode)) { | |
546 | error = PTR_ERR(inode); | |
84b3db04 | 547 | goto out; |
0a370e5d | 548 | } |
1da177e4 | 549 | |
1da177e4 | 550 | error = -ENOMEM; |
c5322220 | 551 | name = dentry_name(dentry); |
84b3db04 | 552 | if (name == NULL) |
1da177e4 LT |
553 | goto out_put; |
554 | ||
555 | fd = file_create(name, | |
556 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
557 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
558 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
4754b825 | 559 | if (fd < 0) |
1da177e4 | 560 | error = fd; |
4754b825 | 561 | else |
5e2df28c | 562 | error = read_name(inode, name); |
1da177e4 | 563 | |
e9193059 | 564 | __putname(name); |
84b3db04 | 565 | if (error) |
1da177e4 LT |
566 | goto out_put; |
567 | ||
568 | HOSTFS_I(inode)->fd = fd; | |
569 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
570 | d_instantiate(dentry, inode); | |
f1adc05e | 571 | return 0; |
1da177e4 LT |
572 | |
573 | out_put: | |
574 | iput(inode); | |
575 | out: | |
f1adc05e | 576 | return error; |
1da177e4 LT |
577 | } |
578 | ||
579 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
f1adc05e | 580 | struct nameidata *nd) |
1da177e4 LT |
581 | { |
582 | struct inode *inode; | |
583 | char *name; | |
584 | int err; | |
585 | ||
0a370e5d DH |
586 | inode = hostfs_iget(ino->i_sb); |
587 | if (IS_ERR(inode)) { | |
588 | err = PTR_ERR(inode); | |
1da177e4 | 589 | goto out; |
0a370e5d | 590 | } |
1da177e4 | 591 | |
1da177e4 | 592 | err = -ENOMEM; |
c5322220 | 593 | name = dentry_name(dentry); |
84b3db04 | 594 | if (name == NULL) |
1da177e4 LT |
595 | goto out_put; |
596 | ||
597 | err = read_name(inode, name); | |
5e2df28c | 598 | |
e9193059 | 599 | __putname(name); |
84b3db04 | 600 | if (err == -ENOENT) { |
1da177e4 LT |
601 | iput(inode); |
602 | inode = NULL; | |
603 | } | |
84b3db04 | 604 | else if (err) |
1da177e4 LT |
605 | goto out_put; |
606 | ||
607 | d_add(dentry, inode); | |
608 | dentry->d_op = &hostfs_dentry_ops; | |
f1adc05e | 609 | return NULL; |
1da177e4 LT |
610 | |
611 | out_put: | |
612 | iput(inode); | |
613 | out: | |
f1adc05e | 614 | return ERR_PTR(err); |
1da177e4 LT |
615 | } |
616 | ||
1da177e4 LT |
617 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) |
618 | { | |
f1adc05e JD |
619 | char *from_name, *to_name; |
620 | int err; | |
1da177e4 | 621 | |
c5322220 | 622 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 623 | return -ENOMEM; |
c5322220 | 624 | to_name = dentry_name(to); |
84b3db04 | 625 | if (to_name == NULL) { |
e9193059 | 626 | __putname(from_name); |
f1adc05e | 627 | return -ENOMEM; |
1da177e4 | 628 | } |
f1adc05e | 629 | err = link_file(to_name, from_name); |
e9193059 AV |
630 | __putname(from_name); |
631 | __putname(to_name); | |
f1adc05e | 632 | return err; |
1da177e4 LT |
633 | } |
634 | ||
635 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
636 | { | |
637 | char *file; | |
638 | int err; | |
639 | ||
84b3db04 | 640 | if (append) |
f1adc05e | 641 | return -EPERM; |
1da177e4 | 642 | |
f8d7e187 AV |
643 | if ((file = dentry_name(dentry)) == NULL) |
644 | return -ENOMEM; | |
645 | ||
1da177e4 | 646 | err = unlink_file(file); |
e9193059 | 647 | __putname(file); |
f1adc05e | 648 | return err; |
1da177e4 LT |
649 | } |
650 | ||
651 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
652 | { | |
653 | char *file; | |
654 | int err; | |
655 | ||
c5322220 | 656 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 657 | return -ENOMEM; |
1da177e4 | 658 | err = make_symlink(file, to); |
e9193059 | 659 | __putname(file); |
f1adc05e | 660 | return err; |
1da177e4 LT |
661 | } |
662 | ||
663 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
664 | { | |
665 | char *file; | |
666 | int err; | |
667 | ||
c5322220 | 668 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 669 | return -ENOMEM; |
1da177e4 | 670 | err = do_mkdir(file, mode); |
e9193059 | 671 | __putname(file); |
f1adc05e | 672 | return err; |
1da177e4 LT |
673 | } |
674 | ||
675 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
676 | { | |
677 | char *file; | |
678 | int err; | |
679 | ||
c5322220 | 680 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 681 | return -ENOMEM; |
1da177e4 | 682 | err = do_rmdir(file); |
e9193059 | 683 | __putname(file); |
f1adc05e | 684 | return err; |
1da177e4 LT |
685 | } |
686 | ||
687 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
688 | { | |
689 | struct inode *inode; | |
690 | char *name; | |
0a370e5d | 691 | int err; |
1da177e4 | 692 | |
0a370e5d DH |
693 | inode = hostfs_iget(dir->i_sb); |
694 | if (IS_ERR(inode)) { | |
695 | err = PTR_ERR(inode); | |
1da177e4 | 696 | goto out; |
0a370e5d | 697 | } |
1da177e4 | 698 | |
1da177e4 | 699 | err = -ENOMEM; |
c5322220 | 700 | name = dentry_name(dentry); |
84b3db04 | 701 | if (name == NULL) |
1da177e4 LT |
702 | goto out_put; |
703 | ||
704 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 705 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
e9193059 | 706 | if (!err) |
1da177e4 LT |
707 | goto out_free; |
708 | ||
709 | err = read_name(inode, name); | |
e9193059 | 710 | __putname(name); |
5e2df28c AV |
711 | if (err) |
712 | goto out_put; | |
84b3db04 | 713 | if (err) |
1da177e4 LT |
714 | goto out_put; |
715 | ||
716 | d_instantiate(dentry, inode); | |
f1adc05e | 717 | return 0; |
1da177e4 LT |
718 | |
719 | out_free: | |
e9193059 | 720 | __putname(name); |
1da177e4 LT |
721 | out_put: |
722 | iput(inode); | |
723 | out: | |
f1adc05e | 724 | return err; |
1da177e4 LT |
725 | } |
726 | ||
727 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
728 | struct inode *to_ino, struct dentry *to) | |
729 | { | |
730 | char *from_name, *to_name; | |
731 | int err; | |
732 | ||
c5322220 | 733 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 734 | return -ENOMEM; |
c5322220 | 735 | if ((to_name = dentry_name(to)) == NULL) { |
e9193059 | 736 | __putname(from_name); |
f1adc05e | 737 | return -ENOMEM; |
1da177e4 LT |
738 | } |
739 | err = rename_file(from_name, to_name); | |
e9193059 AV |
740 | __putname(from_name); |
741 | __putname(to_name); | |
f1adc05e | 742 | return err; |
1da177e4 LT |
743 | } |
744 | ||
e6305c43 | 745 | int hostfs_permission(struct inode *ino, int desired) |
1da177e4 LT |
746 | { |
747 | char *name; | |
748 | int r = 0, w = 0, x = 0, err; | |
749 | ||
750 | if (desired & MAY_READ) r = 1; | |
751 | if (desired & MAY_WRITE) w = 1; | |
752 | if (desired & MAY_EXEC) x = 1; | |
c5322220 | 753 | name = inode_name(ino); |
f1adc05e JD |
754 | if (name == NULL) |
755 | return -ENOMEM; | |
1da177e4 LT |
756 | |
757 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 758 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
759 | err = 0; |
760 | else | |
761 | err = access_file(name, r, w, x); | |
e9193059 | 762 | __putname(name); |
84b3db04 | 763 | if (!err) |
1da177e4 LT |
764 | err = generic_permission(ino, desired, NULL); |
765 | return err; | |
766 | } | |
767 | ||
768 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
769 | { | |
1025774c | 770 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
771 | struct hostfs_iattr attrs; |
772 | char *name; | |
773 | int err; | |
774 | ||
1025774c | 775 | int fd = HOSTFS_I(inode)->fd; |
5822b7fa | 776 | |
1025774c | 777 | err = inode_change_ok(inode, attr); |
1da177e4 LT |
778 | if (err) |
779 | return err; | |
780 | ||
84b3db04 | 781 | if (append) |
1da177e4 LT |
782 | attr->ia_valid &= ~ATTR_SIZE; |
783 | ||
784 | attrs.ia_valid = 0; | |
84b3db04 | 785 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
786 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
787 | attrs.ia_mode = attr->ia_mode; | |
788 | } | |
84b3db04 | 789 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 LT |
790 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
791 | attrs.ia_uid = attr->ia_uid; | |
792 | } | |
84b3db04 | 793 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 LT |
794 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
795 | attrs.ia_gid = attr->ia_gid; | |
796 | } | |
84b3db04 | 797 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
798 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
799 | attrs.ia_size = attr->ia_size; | |
800 | } | |
84b3db04 | 801 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
802 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
803 | attrs.ia_atime = attr->ia_atime; | |
804 | } | |
84b3db04 | 805 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
806 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
807 | attrs.ia_mtime = attr->ia_mtime; | |
808 | } | |
84b3db04 | 809 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
810 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
811 | attrs.ia_ctime = attr->ia_ctime; | |
812 | } | |
84b3db04 | 813 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
814 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
815 | } | |
84b3db04 | 816 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
817 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
818 | } | |
c5322220 | 819 | name = dentry_name(dentry); |
84b3db04 | 820 | if (name == NULL) |
f1adc05e | 821 | return -ENOMEM; |
5822b7fa | 822 | err = set_attr(name, &attrs, fd); |
e9193059 | 823 | __putname(name); |
84b3db04 | 824 | if (err) |
f1adc05e | 825 | return err; |
1da177e4 | 826 | |
1025774c CH |
827 | if ((attr->ia_valid & ATTR_SIZE) && |
828 | attr->ia_size != i_size_read(inode)) { | |
829 | int error; | |
830 | ||
831 | error = vmtruncate(inode, attr->ia_size); | |
832 | if (err) | |
833 | return err; | |
834 | } | |
835 | ||
836 | setattr_copy(inode, attr); | |
837 | mark_inode_dirty(inode); | |
838 | return 0; | |
1da177e4 LT |
839 | } |
840 | ||
92e1d5be | 841 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
842 | .create = hostfs_create, |
843 | .link = hostfs_link, | |
844 | .unlink = hostfs_unlink, | |
845 | .symlink = hostfs_symlink, | |
846 | .mkdir = hostfs_mkdir, | |
847 | .rmdir = hostfs_rmdir, | |
848 | .mknod = hostfs_mknod, | |
849 | .rename = hostfs_rename, | |
1da177e4 LT |
850 | .permission = hostfs_permission, |
851 | .setattr = hostfs_setattr, | |
1da177e4 LT |
852 | }; |
853 | ||
92e1d5be | 854 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
855 | .create = hostfs_create, |
856 | .lookup = hostfs_lookup, | |
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 | ||
d0352d3e AV |
868 | static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
869 | { | |
870 | char *link = __getname(); | |
871 | if (link) { | |
872 | char *path = dentry_name(dentry); | |
873 | int err = -ENOMEM; | |
874 | if (path) { | |
3b6036d1 | 875 | err = hostfs_do_readlink(path, link, PATH_MAX); |
d0352d3e AV |
876 | if (err == PATH_MAX) |
877 | err = -E2BIG; | |
e9193059 | 878 | __putname(path); |
d0352d3e AV |
879 | } |
880 | if (err < 0) { | |
881 | __putname(link); | |
882 | link = ERR_PTR(err); | |
883 | } | |
884 | } else { | |
885 | link = ERR_PTR(-ENOMEM); | |
1da177e4 | 886 | } |
d0352d3e AV |
887 | |
888 | nd_set_link(nd, link); | |
889 | return NULL; | |
890 | } | |
891 | ||
892 | static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) | |
893 | { | |
894 | char *s = nd_get_link(nd); | |
895 | if (!IS_ERR(s)) | |
896 | __putname(s); | |
1da177e4 LT |
897 | } |
898 | ||
d0352d3e AV |
899 | static const struct inode_operations hostfs_link_iops = { |
900 | .readlink = generic_readlink, | |
901 | .follow_link = hostfs_follow_link, | |
902 | .put_link = hostfs_put_link, | |
1da177e4 LT |
903 | }; |
904 | ||
905 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
906 | { | |
907 | struct inode *root_inode; | |
75e8defb | 908 | char *host_root_path, *req_root = d; |
1da177e4 LT |
909 | int err; |
910 | ||
911 | sb->s_blocksize = 1024; | |
912 | sb->s_blocksize_bits = 10; | |
913 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
914 | sb->s_op = &hostfs_sbops; | |
752fa51e | 915 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
1da177e4 | 916 | |
a6eb0be6 | 917 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
918 | if (req_root == NULL) |
919 | req_root = ""; | |
1da177e4 LT |
920 | |
921 | err = -ENOMEM; | |
601d2c38 AV |
922 | sb->s_fs_info = host_root_path = |
923 | kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); | |
84b3db04 | 924 | if (host_root_path == NULL) |
1da177e4 LT |
925 | goto out; |
926 | ||
75e8defb | 927 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 | 928 | |
52b209f7 AV |
929 | root_inode = new_inode(sb); |
930 | if (!root_inode) | |
601d2c38 | 931 | goto out; |
1da177e4 | 932 | |
4754b825 AV |
933 | err = read_name(root_inode, host_root_path); |
934 | if (err) | |
935 | goto out_put; | |
52b209f7 | 936 | |
4754b825 | 937 | if (S_ISLNK(root_inode->i_mode)) { |
52b209f7 AV |
938 | char *name = follow_link(host_root_path); |
939 | if (IS_ERR(name)) | |
940 | err = PTR_ERR(name); | |
941 | else | |
942 | err = read_name(root_inode, name); | |
943 | kfree(name); | |
4754b825 AV |
944 | if (err) |
945 | goto out_put; | |
52b209f7 | 946 | } |
1da177e4 | 947 | |
1da177e4 LT |
948 | err = -ENOMEM; |
949 | sb->s_root = d_alloc_root(root_inode); | |
84b3db04 | 950 | if (sb->s_root == NULL) |
1da177e4 LT |
951 | goto out_put; |
952 | ||
f1adc05e | 953 | return 0; |
1da177e4 | 954 | |
f1adc05e JD |
955 | out_put: |
956 | iput(root_inode); | |
f1adc05e JD |
957 | out: |
958 | return err; | |
1da177e4 LT |
959 | } |
960 | ||
3c26ff6e | 961 | static struct dentry *hostfs_read_sb(struct file_system_type *type, |
454e2398 | 962 | int flags, const char *dev_name, |
3c26ff6e | 963 | void *data) |
1da177e4 | 964 | { |
3c26ff6e | 965 | return mount_nodev(type, flags, data, hostfs_fill_sb_common); |
1da177e4 LT |
966 | } |
967 | ||
601d2c38 AV |
968 | static void hostfs_kill_sb(struct super_block *s) |
969 | { | |
970 | kill_anon_super(s); | |
971 | kfree(s->s_fs_info); | |
972 | } | |
973 | ||
1da177e4 LT |
974 | static struct file_system_type hostfs_type = { |
975 | .owner = THIS_MODULE, | |
976 | .name = "hostfs", | |
3c26ff6e | 977 | .mount = hostfs_read_sb, |
601d2c38 | 978 | .kill_sb = hostfs_kill_sb, |
1da177e4 LT |
979 | .fs_flags = 0, |
980 | }; | |
981 | ||
982 | static int __init init_hostfs(void) | |
983 | { | |
f1adc05e | 984 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
985 | } |
986 | ||
987 | static void __exit exit_hostfs(void) | |
988 | { | |
989 | unregister_filesystem(&hostfs_type); | |
990 | } | |
991 | ||
992 | module_init(init_hostfs) | |
993 | module_exit(exit_hostfs) | |
994 | MODULE_LICENSE("GPL"); |