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> |
1da177e4 | 14 | #include "hostfs.h" |
1da177e4 | 15 | #include "init.h" |
84b3db04 | 16 | #include "kern.h" |
1da177e4 LT |
17 | |
18 | struct hostfs_inode_info { | |
19 | char *host_filename; | |
20 | int fd; | |
21 | int mode; | |
22 | struct inode vfs_inode; | |
23 | }; | |
24 | ||
25 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
26 | { | |
f1adc05e | 27 | return list_entry(inode, struct hostfs_inode_info, vfs_inode); |
1da177e4 LT |
28 | } |
29 | ||
680b0da9 | 30 | #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) |
1da177e4 LT |
31 | |
32 | int hostfs_d_delete(struct dentry *dentry) | |
33 | { | |
f1adc05e | 34 | return 1; |
1da177e4 LT |
35 | } |
36 | ||
37 | struct dentry_operations hostfs_dentry_ops = { | |
38 | .d_delete = hostfs_d_delete, | |
39 | }; | |
40 | ||
41 | /* Changed in hostfs_args before the kernel starts running */ | |
a6eb0be6 | 42 | static char *root_ino = ""; |
1da177e4 LT |
43 | static int append = 0; |
44 | ||
45 | #define HOSTFS_SUPER_MAGIC 0x00c0ffee | |
46 | ||
92e1d5be AV |
47 | static const struct inode_operations hostfs_iops; |
48 | static const struct inode_operations hostfs_dir_iops; | |
f5e54d6e | 49 | static const struct address_space_operations hostfs_link_aops; |
1da177e4 LT |
50 | |
51 | #ifndef MODULE | |
52 | static int __init hostfs_args(char *options, int *add) | |
53 | { | |
54 | char *ptr; | |
55 | ||
56 | ptr = strchr(options, ','); | |
84b3db04 | 57 | if (ptr != NULL) |
1da177e4 | 58 | *ptr++ = '\0'; |
84b3db04 | 59 | if (*options != '\0') |
1da177e4 LT |
60 | root_ino = options; |
61 | ||
62 | options = ptr; | |
84b3db04 | 63 | while (options) { |
1da177e4 | 64 | ptr = strchr(options, ','); |
84b3db04 | 65 | if (ptr != NULL) |
1da177e4 | 66 | *ptr++ = '\0'; |
84b3db04 JD |
67 | if (*options != '\0') { |
68 | if (!strcmp(options, "append")) | |
1da177e4 LT |
69 | append = 1; |
70 | else printf("hostfs_args - unsupported option - %s\n", | |
71 | options); | |
72 | } | |
73 | options = ptr; | |
74 | } | |
f1adc05e | 75 | return 0; |
1da177e4 LT |
76 | } |
77 | ||
78 | __uml_setup("hostfs=", hostfs_args, | |
79 | "hostfs=<root dir>,<flags>,...\n" | |
80 | " This is used to set hostfs parameters. The root directory argument\n" | |
81 | " is used to confine all hostfs mounts to within the specified directory\n" | |
82 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
83 | " mount anything on the host that's accessible to the user that's running\n" | |
84 | " it.\n" | |
85 | " The only flag currently supported is 'append', which specifies that all\n" | |
86 | " files opened by hostfs will be opened in append mode.\n\n" | |
87 | ); | |
88 | #endif | |
89 | ||
90 | static char *dentry_name(struct dentry *dentry, int extra) | |
91 | { | |
92 | struct dentry *parent; | |
93 | char *root, *name; | |
94 | int len; | |
95 | ||
96 | len = 0; | |
97 | parent = dentry; | |
84b3db04 | 98 | while (parent->d_parent != parent) { |
1da177e4 LT |
99 | len += parent->d_name.len + 1; |
100 | parent = parent->d_parent; | |
101 | } | |
102 | ||
103 | root = HOSTFS_I(parent->d_inode)->host_filename; | |
104 | len += strlen(root); | |
105 | name = kmalloc(len + extra + 1, GFP_KERNEL); | |
84b3db04 | 106 | if (name == NULL) |
f1adc05e | 107 | return NULL; |
1da177e4 LT |
108 | |
109 | name[len] = '\0'; | |
110 | parent = dentry; | |
84b3db04 | 111 | while (parent->d_parent != parent) { |
1da177e4 LT |
112 | len -= parent->d_name.len + 1; |
113 | name[len] = '/'; | |
114 | strncpy(&name[len + 1], parent->d_name.name, | |
115 | parent->d_name.len); | |
116 | parent = parent->d_parent; | |
117 | } | |
118 | strncpy(name, root, strlen(root)); | |
f1adc05e | 119 | return name; |
1da177e4 LT |
120 | } |
121 | ||
122 | static char *inode_name(struct inode *ino, int extra) | |
123 | { | |
124 | struct dentry *dentry; | |
125 | ||
126 | dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); | |
f1adc05e | 127 | return dentry_name(dentry, extra); |
1da177e4 LT |
128 | } |
129 | ||
130 | static int read_name(struct inode *ino, char *name) | |
131 | { | |
84b3db04 JD |
132 | /* |
133 | * The non-int inode fields are copied into ints by stat_file and | |
1da177e4 LT |
134 | * then copied into the inode because passing the actual pointers |
135 | * in and having them treated as int * breaks on big-endian machines | |
136 | */ | |
137 | int err; | |
138 | int i_mode, i_nlink, i_blksize; | |
139 | unsigned long long i_size; | |
140 | unsigned long long i_ino; | |
141 | unsigned long long i_blocks; | |
142 | ||
143 | err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid, | |
144 | &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime, | |
5822b7fa | 145 | &ino->i_ctime, &i_blksize, &i_blocks, -1); |
84b3db04 | 146 | if (err) |
f1adc05e | 147 | return err; |
1da177e4 LT |
148 | |
149 | ino->i_ino = i_ino; | |
150 | ino->i_mode = i_mode; | |
151 | ino->i_nlink = i_nlink; | |
152 | ino->i_size = i_size; | |
1da177e4 | 153 | ino->i_blocks = i_blocks; |
f1adc05e | 154 | return 0; |
1da177e4 LT |
155 | } |
156 | ||
157 | static char *follow_link(char *link) | |
158 | { | |
159 | int len, n; | |
160 | char *name, *resolved, *end; | |
161 | ||
162 | len = 64; | |
84b3db04 | 163 | while (1) { |
1da177e4 LT |
164 | n = -ENOMEM; |
165 | name = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 166 | if (name == NULL) |
1da177e4 LT |
167 | goto out; |
168 | ||
169 | n = do_readlink(link, name, len); | |
84b3db04 | 170 | if (n < len) |
1da177e4 LT |
171 | break; |
172 | len *= 2; | |
173 | kfree(name); | |
174 | } | |
84b3db04 | 175 | if (n < 0) |
1da177e4 LT |
176 | goto out_free; |
177 | ||
84b3db04 | 178 | if (*name == '/') |
f1adc05e | 179 | return name; |
1da177e4 LT |
180 | |
181 | end = strrchr(link, '/'); | |
84b3db04 | 182 | if (end == NULL) |
f1adc05e | 183 | return name; |
1da177e4 LT |
184 | |
185 | *(end + 1) = '\0'; | |
186 | len = strlen(link) + strlen(name) + 1; | |
187 | ||
188 | resolved = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 189 | if (resolved == NULL) { |
1da177e4 LT |
190 | n = -ENOMEM; |
191 | goto out_free; | |
192 | } | |
193 | ||
194 | sprintf(resolved, "%s%s", link, name); | |
195 | kfree(name); | |
196 | kfree(link); | |
f1adc05e | 197 | return resolved; |
1da177e4 LT |
198 | |
199 | out_free: | |
200 | kfree(name); | |
201 | out: | |
f1adc05e | 202 | return ERR_PTR(n); |
1da177e4 LT |
203 | } |
204 | ||
205 | static int read_inode(struct inode *ino) | |
206 | { | |
207 | char *name; | |
208 | int err = 0; | |
209 | ||
84b3db04 JD |
210 | /* |
211 | * Unfortunately, we are called from iget() when we don't have a dentry | |
1da177e4 LT |
212 | * allocated yet. |
213 | */ | |
84b3db04 | 214 | if (list_empty(&ino->i_dentry)) |
1da177e4 LT |
215 | goto out; |
216 | ||
217 | err = -ENOMEM; | |
218 | name = inode_name(ino, 0); | |
84b3db04 | 219 | if (name == NULL) |
1da177e4 LT |
220 | goto out; |
221 | ||
84b3db04 | 222 | if (file_type(name, NULL, NULL) == OS_TYPE_SYMLINK) { |
1da177e4 | 223 | name = follow_link(name); |
84b3db04 | 224 | if (IS_ERR(name)) { |
1da177e4 LT |
225 | err = PTR_ERR(name); |
226 | goto out; | |
227 | } | |
228 | } | |
229 | ||
230 | err = read_name(ino, name); | |
231 | kfree(name); | |
232 | out: | |
f1adc05e | 233 | return err; |
1da177e4 LT |
234 | } |
235 | ||
726c3342 | 236 | int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 | 237 | { |
84b3db04 JD |
238 | /* |
239 | * do_statfs uses struct statfs64 internally, but the linux kernel | |
1da177e4 LT |
240 | * struct statfs still has 32-bit versions for most of these fields, |
241 | * so we convert them here | |
242 | */ | |
243 | int err; | |
244 | long long f_blocks; | |
245 | long long f_bfree; | |
246 | long long f_bavail; | |
247 | long long f_files; | |
248 | long long f_ffree; | |
249 | ||
726c3342 | 250 | err = do_statfs(HOSTFS_I(dentry->d_sb->s_root->d_inode)->host_filename, |
1da177e4 LT |
251 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
252 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
253 | &sf->f_namelen, sf->f_spare); | |
84b3db04 | 254 | if (err) |
f1adc05e | 255 | return err; |
1da177e4 LT |
256 | sf->f_blocks = f_blocks; |
257 | sf->f_bfree = f_bfree; | |
258 | sf->f_bavail = f_bavail; | |
259 | sf->f_files = f_files; | |
260 | sf->f_ffree = f_ffree; | |
261 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
f1adc05e | 262 | return 0; |
1da177e4 LT |
263 | } |
264 | ||
265 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
266 | { | |
267 | struct hostfs_inode_info *hi; | |
268 | ||
269 | hi = kmalloc(sizeof(*hi), GFP_KERNEL); | |
84b3db04 | 270 | if (hi == NULL) |
f1adc05e | 271 | return NULL; |
1da177e4 LT |
272 | |
273 | *hi = ((struct hostfs_inode_info) { .host_filename = NULL, | |
274 | .fd = -1, | |
275 | .mode = 0 }); | |
276 | inode_init_once(&hi->vfs_inode); | |
f1adc05e | 277 | return &hi->vfs_inode; |
1da177e4 LT |
278 | } |
279 | ||
280 | static void hostfs_delete_inode(struct inode *inode) | |
281 | { | |
fef26658 | 282 | truncate_inode_pages(&inode->i_data, 0); |
84b3db04 | 283 | if (HOSTFS_I(inode)->fd != -1) { |
1da177e4 LT |
284 | close_file(&HOSTFS_I(inode)->fd); |
285 | HOSTFS_I(inode)->fd = -1; | |
286 | } | |
287 | clear_inode(inode); | |
288 | } | |
289 | ||
290 | static void hostfs_destroy_inode(struct inode *inode) | |
291 | { | |
f99d49ad | 292 | kfree(HOSTFS_I(inode)->host_filename); |
1da177e4 | 293 | |
84b3db04 JD |
294 | /* |
295 | * XXX: This should not happen, probably. The check is here for | |
296 | * additional safety. | |
297 | */ | |
298 | if (HOSTFS_I(inode)->fd != -1) { | |
1da177e4 LT |
299 | close_file(&HOSTFS_I(inode)->fd); |
300 | printk(KERN_DEBUG "Closing host fd in .destroy_inode\n"); | |
301 | } | |
302 | ||
303 | kfree(HOSTFS_I(inode)); | |
304 | } | |
305 | ||
306 | static void hostfs_read_inode(struct inode *inode) | |
307 | { | |
308 | read_inode(inode); | |
309 | } | |
310 | ||
ee9b6d61 | 311 | static const struct super_operations hostfs_sbops = { |
1da177e4 LT |
312 | .alloc_inode = hostfs_alloc_inode, |
313 | .drop_inode = generic_delete_inode, | |
314 | .delete_inode = hostfs_delete_inode, | |
315 | .destroy_inode = hostfs_destroy_inode, | |
316 | .read_inode = hostfs_read_inode, | |
317 | .statfs = hostfs_statfs, | |
318 | }; | |
319 | ||
320 | int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) | |
321 | { | |
322 | void *dir; | |
323 | char *name; | |
324 | unsigned long long next, ino; | |
325 | int error, len; | |
326 | ||
680b0da9 | 327 | name = dentry_name(file->f_path.dentry, 0); |
84b3db04 | 328 | if (name == NULL) |
f1adc05e | 329 | return -ENOMEM; |
1da177e4 LT |
330 | dir = open_dir(name, &error); |
331 | kfree(name); | |
84b3db04 | 332 | if (dir == NULL) |
f1adc05e | 333 | return -error; |
1da177e4 | 334 | next = file->f_pos; |
84b3db04 | 335 | while ((name = read_dir(dir, &next, &ino, &len)) != NULL) { |
1da177e4 LT |
336 | error = (*filldir)(ent, name, len, file->f_pos, |
337 | ino, DT_UNKNOWN); | |
84b3db04 | 338 | if (error) break; |
1da177e4 LT |
339 | file->f_pos = next; |
340 | } | |
341 | close_dir(dir); | |
f1adc05e | 342 | return 0; |
1da177e4 LT |
343 | } |
344 | ||
345 | int hostfs_file_open(struct inode *ino, struct file *file) | |
346 | { | |
347 | char *name; | |
348 | int mode = 0, r = 0, w = 0, fd; | |
349 | ||
350 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 351 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 352 | return 0; |
1da177e4 | 353 | |
84b3db04 JD |
354 | /* |
355 | * The file may already have been opened, but with the wrong access, | |
1da177e4 LT |
356 | * so this resets things and reopens the file with the new access. |
357 | */ | |
84b3db04 | 358 | if (HOSTFS_I(ino)->fd != -1) { |
1da177e4 LT |
359 | close_file(&HOSTFS_I(ino)->fd); |
360 | HOSTFS_I(ino)->fd = -1; | |
361 | } | |
362 | ||
363 | HOSTFS_I(ino)->mode |= mode; | |
84b3db04 | 364 | if (HOSTFS_I(ino)->mode & FMODE_READ) |
1da177e4 | 365 | r = 1; |
84b3db04 | 366 | if (HOSTFS_I(ino)->mode & FMODE_WRITE) |
1da177e4 | 367 | w = 1; |
84b3db04 | 368 | if (w) |
1da177e4 LT |
369 | r = 1; |
370 | ||
680b0da9 | 371 | name = dentry_name(file->f_path.dentry, 0); |
84b3db04 | 372 | if (name == NULL) |
f1adc05e | 373 | return -ENOMEM; |
1da177e4 LT |
374 | |
375 | fd = open_file(name, r, w, append); | |
376 | kfree(name); | |
84b3db04 | 377 | if (fd < 0) |
f1adc05e | 378 | return fd; |
1da177e4 LT |
379 | FILE_HOSTFS_I(file)->fd = fd; |
380 | ||
f1adc05e | 381 | return 0; |
1da177e4 LT |
382 | } |
383 | ||
384 | int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync) | |
385 | { | |
a2d76bd8 | 386 | return fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync); |
1da177e4 LT |
387 | } |
388 | ||
4b6f5d20 | 389 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 390 | .llseek = generic_file_llseek, |
543ade1f | 391 | .read = do_sync_read, |
5ffc4ef4 | 392 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
393 | .aio_read = generic_file_aio_read, |
394 | .aio_write = generic_file_aio_write, | |
543ade1f | 395 | .write = do_sync_write, |
1da177e4 LT |
396 | .mmap = generic_file_mmap, |
397 | .open = hostfs_file_open, | |
398 | .release = NULL, | |
399 | .fsync = hostfs_fsync, | |
400 | }; | |
401 | ||
4b6f5d20 | 402 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
403 | .llseek = generic_file_llseek, |
404 | .readdir = hostfs_readdir, | |
405 | .read = generic_read_dir, | |
406 | }; | |
407 | ||
408 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
409 | { | |
410 | struct address_space *mapping = page->mapping; | |
411 | struct inode *inode = mapping->host; | |
412 | char *buffer; | |
413 | unsigned long long base; | |
414 | int count = PAGE_CACHE_SIZE; | |
415 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
416 | int err; | |
417 | ||
418 | if (page->index >= end_index) | |
419 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
420 | ||
421 | buffer = kmap(page); | |
422 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
423 | ||
424 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 425 | if (err != count) { |
1da177e4 LT |
426 | ClearPageUptodate(page); |
427 | goto out; | |
428 | } | |
429 | ||
430 | if (base > inode->i_size) | |
431 | inode->i_size = base; | |
432 | ||
433 | if (PageError(page)) | |
434 | ClearPageError(page); | |
435 | err = 0; | |
436 | ||
437 | out: | |
438 | kunmap(page); | |
439 | ||
440 | unlock_page(page); | |
441 | return err; | |
442 | } | |
443 | ||
444 | int hostfs_readpage(struct file *file, struct page *page) | |
445 | { | |
446 | char *buffer; | |
447 | long long start; | |
448 | int err = 0; | |
449 | ||
450 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
451 | buffer = kmap(page); | |
452 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
453 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
454 | if (err < 0) |
455 | goto out; | |
1da177e4 LT |
456 | |
457 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
458 | ||
459 | flush_dcache_page(page); | |
460 | SetPageUptodate(page); | |
461 | if (PageError(page)) ClearPageError(page); | |
462 | err = 0; | |
463 | out: | |
464 | kunmap(page); | |
465 | unlock_page(page); | |
f1adc05e | 466 | return err; |
1da177e4 LT |
467 | } |
468 | ||
ae361ff4 NP |
469 | int hostfs_write_begin(struct file *file, struct address_space *mapping, |
470 | loff_t pos, unsigned len, unsigned flags, | |
471 | struct page **pagep, void **fsdata) | |
1da177e4 | 472 | { |
ae361ff4 | 473 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 474 | |
ae361ff4 NP |
475 | *pagep = __grab_cache_page(mapping, index); |
476 | if (!*pagep) | |
477 | return -ENOMEM; | |
478 | return 0; | |
1da177e4 LT |
479 | } |
480 | ||
ae361ff4 NP |
481 | int hostfs_write_end(struct file *file, struct address_space *mapping, |
482 | loff_t pos, unsigned len, unsigned copied, | |
483 | struct page *page, void *fsdata) | |
1da177e4 | 484 | { |
1da177e4 | 485 | struct inode *inode = mapping->host; |
ae361ff4 NP |
486 | void *buffer; |
487 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
488 | int err; | |
1da177e4 | 489 | |
1da177e4 | 490 | buffer = kmap(page); |
ae361ff4 NP |
491 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
492 | kunmap(page); | |
30f04a4e | 493 | |
ae361ff4 NP |
494 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
495 | SetPageUptodate(page); | |
30f04a4e | 496 | |
84b3db04 JD |
497 | /* |
498 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
499 | * i_size against the last byte written. |
500 | */ | |
501 | if (err > 0 && (pos > inode->i_size)) | |
502 | inode->i_size = pos; | |
503 | unlock_page(page); | |
504 | page_cache_release(page); | |
1da177e4 | 505 | |
f1adc05e | 506 | return err; |
1da177e4 LT |
507 | } |
508 | ||
f5e54d6e | 509 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
510 | .writepage = hostfs_writepage, |
511 | .readpage = hostfs_readpage, | |
ffa0aea6 | 512 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
513 | .write_begin = hostfs_write_begin, |
514 | .write_end = hostfs_write_end, | |
1da177e4 LT |
515 | }; |
516 | ||
517 | static int init_inode(struct inode *inode, struct dentry *dentry) | |
518 | { | |
519 | char *name; | |
520 | int type, err = -ENOMEM; | |
521 | int maj, min; | |
522 | dev_t rdev = 0; | |
523 | ||
84b3db04 | 524 | if (dentry) { |
1da177e4 | 525 | name = dentry_name(dentry, 0); |
84b3db04 | 526 | if (name == NULL) |
1da177e4 LT |
527 | goto out; |
528 | type = file_type(name, &maj, &min); | |
84b3db04 | 529 | /* Reencode maj and min with the kernel encoding.*/ |
1da177e4 LT |
530 | rdev = MKDEV(maj, min); |
531 | kfree(name); | |
532 | } | |
533 | else type = OS_TYPE_DIR; | |
534 | ||
535 | err = 0; | |
84b3db04 | 536 | if (type == OS_TYPE_SYMLINK) |
1da177e4 | 537 | inode->i_op = &page_symlink_inode_operations; |
84b3db04 | 538 | else if (type == OS_TYPE_DIR) |
1da177e4 LT |
539 | inode->i_op = &hostfs_dir_iops; |
540 | else inode->i_op = &hostfs_iops; | |
541 | ||
84b3db04 | 542 | if (type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; |
1da177e4 LT |
543 | else inode->i_fop = &hostfs_file_fops; |
544 | ||
84b3db04 | 545 | if (type == OS_TYPE_SYMLINK) |
1da177e4 LT |
546 | inode->i_mapping->a_ops = &hostfs_link_aops; |
547 | else inode->i_mapping->a_ops = &hostfs_aops; | |
548 | ||
549 | switch (type) { | |
550 | case OS_TYPE_CHARDEV: | |
551 | init_special_inode(inode, S_IFCHR, rdev); | |
552 | break; | |
553 | case OS_TYPE_BLOCKDEV: | |
554 | init_special_inode(inode, S_IFBLK, rdev); | |
555 | break; | |
556 | case OS_TYPE_FIFO: | |
557 | init_special_inode(inode, S_IFIFO, 0); | |
558 | break; | |
559 | case OS_TYPE_SOCK: | |
560 | init_special_inode(inode, S_IFSOCK, 0); | |
561 | break; | |
562 | } | |
563 | out: | |
f1adc05e | 564 | return err; |
1da177e4 LT |
565 | } |
566 | ||
567 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
84b3db04 | 568 | struct nameidata *nd) |
1da177e4 LT |
569 | { |
570 | struct inode *inode; | |
571 | char *name; | |
572 | int error, fd; | |
573 | ||
574 | error = -ENOMEM; | |
575 | inode = iget(dir->i_sb, 0); | |
84b3db04 JD |
576 | if (inode == NULL) |
577 | goto out; | |
1da177e4 LT |
578 | |
579 | error = init_inode(inode, dentry); | |
84b3db04 | 580 | if (error) |
1da177e4 LT |
581 | goto out_put; |
582 | ||
583 | error = -ENOMEM; | |
584 | name = dentry_name(dentry, 0); | |
84b3db04 | 585 | if (name == NULL) |
1da177e4 LT |
586 | goto out_put; |
587 | ||
588 | fd = file_create(name, | |
589 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
590 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
591 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
84b3db04 | 592 | if (fd < 0) |
1da177e4 LT |
593 | error = fd; |
594 | else error = read_name(inode, name); | |
595 | ||
596 | kfree(name); | |
84b3db04 | 597 | if (error) |
1da177e4 LT |
598 | goto out_put; |
599 | ||
600 | HOSTFS_I(inode)->fd = fd; | |
601 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
602 | d_instantiate(dentry, inode); | |
f1adc05e | 603 | return 0; |
1da177e4 LT |
604 | |
605 | out_put: | |
606 | iput(inode); | |
607 | out: | |
f1adc05e | 608 | return error; |
1da177e4 LT |
609 | } |
610 | ||
611 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
f1adc05e | 612 | struct nameidata *nd) |
1da177e4 LT |
613 | { |
614 | struct inode *inode; | |
615 | char *name; | |
616 | int err; | |
617 | ||
618 | err = -ENOMEM; | |
619 | inode = iget(ino->i_sb, 0); | |
84b3db04 | 620 | if (inode == NULL) |
1da177e4 LT |
621 | goto out; |
622 | ||
623 | err = init_inode(inode, dentry); | |
84b3db04 | 624 | if (err) |
1da177e4 LT |
625 | goto out_put; |
626 | ||
627 | err = -ENOMEM; | |
628 | name = dentry_name(dentry, 0); | |
84b3db04 | 629 | if (name == NULL) |
1da177e4 LT |
630 | goto out_put; |
631 | ||
632 | err = read_name(inode, name); | |
633 | kfree(name); | |
84b3db04 | 634 | if (err == -ENOENT) { |
1da177e4 LT |
635 | iput(inode); |
636 | inode = NULL; | |
637 | } | |
84b3db04 | 638 | else if (err) |
1da177e4 LT |
639 | goto out_put; |
640 | ||
641 | d_add(dentry, inode); | |
642 | dentry->d_op = &hostfs_dentry_ops; | |
f1adc05e | 643 | return NULL; |
1da177e4 LT |
644 | |
645 | out_put: | |
646 | iput(inode); | |
647 | out: | |
f1adc05e | 648 | return ERR_PTR(err); |
1da177e4 LT |
649 | } |
650 | ||
651 | static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) | |
652 | { | |
f1adc05e | 653 | char *file; |
1da177e4 LT |
654 | int len; |
655 | ||
656 | file = inode_name(ino, dentry->d_name.len + 1); | |
84b3db04 | 657 | if (file == NULL) |
f1adc05e JD |
658 | return NULL; |
659 | strcat(file, "/"); | |
1da177e4 | 660 | len = strlen(file); |
f1adc05e | 661 | strncat(file, dentry->d_name.name, dentry->d_name.len); |
1da177e4 | 662 | file[len + dentry->d_name.len] = '\0'; |
f1adc05e | 663 | return file; |
1da177e4 LT |
664 | } |
665 | ||
666 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) | |
667 | { | |
f1adc05e JD |
668 | char *from_name, *to_name; |
669 | int err; | |
1da177e4 | 670 | |
84b3db04 | 671 | if ((from_name = inode_dentry_name(ino, from)) == NULL) |
f1adc05e JD |
672 | return -ENOMEM; |
673 | to_name = dentry_name(to, 0); | |
84b3db04 | 674 | if (to_name == NULL) { |
1da177e4 | 675 | kfree(from_name); |
f1adc05e | 676 | return -ENOMEM; |
1da177e4 | 677 | } |
f1adc05e JD |
678 | err = link_file(to_name, from_name); |
679 | kfree(from_name); | |
680 | kfree(to_name); | |
681 | return err; | |
1da177e4 LT |
682 | } |
683 | ||
684 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
685 | { | |
686 | char *file; | |
687 | int err; | |
688 | ||
84b3db04 | 689 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 690 | return -ENOMEM; |
84b3db04 | 691 | if (append) |
f1adc05e | 692 | return -EPERM; |
1da177e4 LT |
693 | |
694 | err = unlink_file(file); | |
695 | kfree(file); | |
f1adc05e | 696 | return err; |
1da177e4 LT |
697 | } |
698 | ||
699 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
700 | { | |
701 | char *file; | |
702 | int err; | |
703 | ||
84b3db04 | 704 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 705 | return -ENOMEM; |
1da177e4 LT |
706 | err = make_symlink(file, to); |
707 | kfree(file); | |
f1adc05e | 708 | return err; |
1da177e4 LT |
709 | } |
710 | ||
711 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
712 | { | |
713 | char *file; | |
714 | int err; | |
715 | ||
84b3db04 | 716 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 717 | return -ENOMEM; |
1da177e4 LT |
718 | err = do_mkdir(file, mode); |
719 | kfree(file); | |
f1adc05e | 720 | return err; |
1da177e4 LT |
721 | } |
722 | ||
723 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
724 | { | |
725 | char *file; | |
726 | int err; | |
727 | ||
84b3db04 | 728 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 729 | return -ENOMEM; |
1da177e4 LT |
730 | err = do_rmdir(file); |
731 | kfree(file); | |
f1adc05e | 732 | return err; |
1da177e4 LT |
733 | } |
734 | ||
735 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
736 | { | |
737 | struct inode *inode; | |
738 | char *name; | |
739 | int err = -ENOMEM; | |
740 | ||
741 | inode = iget(dir->i_sb, 0); | |
84b3db04 | 742 | if (inode == NULL) |
1da177e4 LT |
743 | goto out; |
744 | ||
745 | err = init_inode(inode, dentry); | |
84b3db04 | 746 | if (err) |
1da177e4 LT |
747 | goto out_put; |
748 | ||
749 | err = -ENOMEM; | |
750 | name = dentry_name(dentry, 0); | |
84b3db04 | 751 | if (name == NULL) |
1da177e4 LT |
752 | goto out_put; |
753 | ||
754 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 755 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
84b3db04 | 756 | if (err) |
1da177e4 LT |
757 | goto out_free; |
758 | ||
759 | err = read_name(inode, name); | |
760 | kfree(name); | |
84b3db04 | 761 | if (err) |
1da177e4 LT |
762 | goto out_put; |
763 | ||
764 | d_instantiate(dentry, inode); | |
f1adc05e | 765 | return 0; |
1da177e4 LT |
766 | |
767 | out_free: | |
768 | kfree(name); | |
769 | out_put: | |
770 | iput(inode); | |
771 | out: | |
f1adc05e | 772 | return err; |
1da177e4 LT |
773 | } |
774 | ||
775 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
776 | struct inode *to_ino, struct dentry *to) | |
777 | { | |
778 | char *from_name, *to_name; | |
779 | int err; | |
780 | ||
84b3db04 | 781 | if ((from_name = inode_dentry_name(from_ino, from)) == NULL) |
f1adc05e | 782 | return -ENOMEM; |
84b3db04 | 783 | if ((to_name = inode_dentry_name(to_ino, to)) == NULL) { |
1da177e4 | 784 | kfree(from_name); |
f1adc05e | 785 | return -ENOMEM; |
1da177e4 LT |
786 | } |
787 | err = rename_file(from_name, to_name); | |
788 | kfree(from_name); | |
789 | kfree(to_name); | |
f1adc05e | 790 | return err; |
1da177e4 LT |
791 | } |
792 | ||
1da177e4 LT |
793 | int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) |
794 | { | |
795 | char *name; | |
796 | int r = 0, w = 0, x = 0, err; | |
797 | ||
798 | if (desired & MAY_READ) r = 1; | |
799 | if (desired & MAY_WRITE) w = 1; | |
800 | if (desired & MAY_EXEC) x = 1; | |
801 | name = inode_name(ino, 0); | |
f1adc05e JD |
802 | if (name == NULL) |
803 | return -ENOMEM; | |
1da177e4 LT |
804 | |
805 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 806 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
807 | err = 0; |
808 | else | |
809 | err = access_file(name, r, w, x); | |
810 | kfree(name); | |
84b3db04 | 811 | if (!err) |
1da177e4 LT |
812 | err = generic_permission(ino, desired, NULL); |
813 | return err; | |
814 | } | |
815 | ||
816 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
817 | { | |
818 | struct hostfs_iattr attrs; | |
819 | char *name; | |
820 | int err; | |
821 | ||
5822b7fa AB |
822 | int fd = HOSTFS_I(dentry->d_inode)->fd; |
823 | ||
1da177e4 LT |
824 | err = inode_change_ok(dentry->d_inode, attr); |
825 | if (err) | |
826 | return err; | |
827 | ||
84b3db04 | 828 | if (append) |
1da177e4 LT |
829 | attr->ia_valid &= ~ATTR_SIZE; |
830 | ||
831 | attrs.ia_valid = 0; | |
84b3db04 | 832 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
833 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
834 | attrs.ia_mode = attr->ia_mode; | |
835 | } | |
84b3db04 | 836 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 LT |
837 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
838 | attrs.ia_uid = attr->ia_uid; | |
839 | } | |
84b3db04 | 840 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 LT |
841 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
842 | attrs.ia_gid = attr->ia_gid; | |
843 | } | |
84b3db04 | 844 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
845 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
846 | attrs.ia_size = attr->ia_size; | |
847 | } | |
84b3db04 | 848 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
849 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
850 | attrs.ia_atime = attr->ia_atime; | |
851 | } | |
84b3db04 | 852 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
853 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
854 | attrs.ia_mtime = attr->ia_mtime; | |
855 | } | |
84b3db04 | 856 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
857 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
858 | attrs.ia_ctime = attr->ia_ctime; | |
859 | } | |
84b3db04 | 860 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
861 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
862 | } | |
84b3db04 | 863 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
864 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
865 | } | |
866 | name = dentry_name(dentry, 0); | |
84b3db04 | 867 | if (name == NULL) |
f1adc05e | 868 | return -ENOMEM; |
5822b7fa | 869 | err = set_attr(name, &attrs, fd); |
1da177e4 | 870 | kfree(name); |
84b3db04 | 871 | if (err) |
f1adc05e | 872 | return err; |
1da177e4 | 873 | |
f1adc05e | 874 | return inode_setattr(dentry->d_inode, attr); |
1da177e4 LT |
875 | } |
876 | ||
92e1d5be | 877 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
878 | .create = hostfs_create, |
879 | .link = hostfs_link, | |
880 | .unlink = hostfs_unlink, | |
881 | .symlink = hostfs_symlink, | |
882 | .mkdir = hostfs_mkdir, | |
883 | .rmdir = hostfs_rmdir, | |
884 | .mknod = hostfs_mknod, | |
885 | .rename = hostfs_rename, | |
1da177e4 LT |
886 | .permission = hostfs_permission, |
887 | .setattr = hostfs_setattr, | |
1da177e4 LT |
888 | }; |
889 | ||
92e1d5be | 890 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
891 | .create = hostfs_create, |
892 | .lookup = hostfs_lookup, | |
893 | .link = hostfs_link, | |
894 | .unlink = hostfs_unlink, | |
895 | .symlink = hostfs_symlink, | |
896 | .mkdir = hostfs_mkdir, | |
897 | .rmdir = hostfs_rmdir, | |
898 | .mknod = hostfs_mknod, | |
899 | .rename = hostfs_rename, | |
1da177e4 LT |
900 | .permission = hostfs_permission, |
901 | .setattr = hostfs_setattr, | |
1da177e4 LT |
902 | }; |
903 | ||
904 | int hostfs_link_readpage(struct file *file, struct page *page) | |
905 | { | |
906 | char *buffer, *name; | |
1da177e4 LT |
907 | int err; |
908 | ||
1da177e4 LT |
909 | buffer = kmap(page); |
910 | name = inode_name(page->mapping->host, 0); | |
84b3db04 | 911 | if (name == NULL) |
f1adc05e | 912 | return -ENOMEM; |
1da177e4 LT |
913 | err = do_readlink(name, buffer, PAGE_CACHE_SIZE); |
914 | kfree(name); | |
84b3db04 | 915 | if (err == PAGE_CACHE_SIZE) |
1da177e4 | 916 | err = -E2BIG; |
84b3db04 | 917 | else if (err > 0) { |
1da177e4 LT |
918 | flush_dcache_page(page); |
919 | SetPageUptodate(page); | |
920 | if (PageError(page)) ClearPageError(page); | |
921 | err = 0; | |
922 | } | |
923 | kunmap(page); | |
924 | unlock_page(page); | |
f1adc05e | 925 | return err; |
1da177e4 LT |
926 | } |
927 | ||
f5e54d6e | 928 | static const struct address_space_operations hostfs_link_aops = { |
1da177e4 LT |
929 | .readpage = hostfs_link_readpage, |
930 | }; | |
931 | ||
932 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
933 | { | |
934 | struct inode *root_inode; | |
75e8defb | 935 | char *host_root_path, *req_root = d; |
1da177e4 LT |
936 | int err; |
937 | ||
938 | sb->s_blocksize = 1024; | |
939 | sb->s_blocksize_bits = 10; | |
940 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
941 | sb->s_op = &hostfs_sbops; | |
942 | ||
a6eb0be6 | 943 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
944 | if (req_root == NULL) |
945 | req_root = ""; | |
1da177e4 LT |
946 | |
947 | err = -ENOMEM; | |
75e8defb PBG |
948 | host_root_path = kmalloc(strlen(root_ino) + 1 |
949 | + strlen(req_root) + 1, GFP_KERNEL); | |
84b3db04 | 950 | if (host_root_path == NULL) |
1da177e4 LT |
951 | goto out; |
952 | ||
75e8defb | 953 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 LT |
954 | |
955 | root_inode = iget(sb, 0); | |
84b3db04 | 956 | if (root_inode == NULL) |
1da177e4 LT |
957 | goto out_free; |
958 | ||
959 | err = init_inode(root_inode, NULL); | |
84b3db04 | 960 | if (err) |
1da177e4 LT |
961 | goto out_put; |
962 | ||
75e8defb | 963 | HOSTFS_I(root_inode)->host_filename = host_root_path; |
84b3db04 JD |
964 | /* |
965 | * Avoid that in the error path, iput(root_inode) frees again | |
966 | * host_root_path through hostfs_destroy_inode! | |
967 | */ | |
75e8defb | 968 | host_root_path = NULL; |
1da177e4 LT |
969 | |
970 | err = -ENOMEM; | |
971 | sb->s_root = d_alloc_root(root_inode); | |
84b3db04 | 972 | if (sb->s_root == NULL) |
1da177e4 LT |
973 | goto out_put; |
974 | ||
975 | err = read_inode(root_inode); | |
84b3db04 | 976 | if (err) { |
f1adc05e JD |
977 | /* No iput in this case because the dput does that for us */ |
978 | dput(sb->s_root); | |
979 | sb->s_root = NULL; | |
bca27113 | 980 | goto out; |
f1adc05e | 981 | } |
1da177e4 | 982 | |
f1adc05e | 983 | return 0; |
1da177e4 | 984 | |
f1adc05e JD |
985 | out_put: |
986 | iput(root_inode); | |
987 | out_free: | |
75e8defb | 988 | kfree(host_root_path); |
f1adc05e JD |
989 | out: |
990 | return err; | |
1da177e4 LT |
991 | } |
992 | ||
454e2398 DH |
993 | static int hostfs_read_sb(struct file_system_type *type, |
994 | int flags, const char *dev_name, | |
995 | void *data, struct vfsmount *mnt) | |
1da177e4 | 996 | { |
454e2398 | 997 | return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); |
1da177e4 LT |
998 | } |
999 | ||
1000 | static struct file_system_type hostfs_type = { | |
1001 | .owner = THIS_MODULE, | |
1002 | .name = "hostfs", | |
1003 | .get_sb = hostfs_read_sb, | |
1004 | .kill_sb = kill_anon_super, | |
1005 | .fs_flags = 0, | |
1006 | }; | |
1007 | ||
1008 | static int __init init_hostfs(void) | |
1009 | { | |
f1adc05e | 1010 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
1011 | } |
1012 | ||
1013 | static void __exit exit_hostfs(void) | |
1014 | { | |
1015 | unregister_filesystem(&hostfs_type); | |
1016 | } | |
1017 | ||
1018 | module_init(init_hostfs) | |
1019 | module_exit(exit_hostfs) | |
1020 | MODULE_LICENSE("GPL"); |