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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> |
dd2cc4df | 14 | #include <linux/seq_file.h> |
1da177e4 | 15 | #include "hostfs.h" |
1da177e4 | 16 | #include "init.h" |
84b3db04 | 17 | #include "kern.h" |
1da177e4 LT |
18 | |
19 | struct hostfs_inode_info { | |
20 | char *host_filename; | |
21 | int fd; | |
22 | int mode; | |
23 | struct inode vfs_inode; | |
24 | }; | |
25 | ||
26 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
27 | { | |
f1adc05e | 28 | return list_entry(inode, struct hostfs_inode_info, vfs_inode); |
1da177e4 LT |
29 | } |
30 | ||
680b0da9 | 31 | #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) |
1da177e4 LT |
32 | |
33 | int hostfs_d_delete(struct dentry *dentry) | |
34 | { | |
f1adc05e | 35 | return 1; |
1da177e4 LT |
36 | } |
37 | ||
38 | struct dentry_operations hostfs_dentry_ops = { | |
39 | .d_delete = hostfs_d_delete, | |
40 | }; | |
41 | ||
42 | /* Changed in hostfs_args before the kernel starts running */ | |
a6eb0be6 | 43 | static char *root_ino = ""; |
1da177e4 LT |
44 | static int append = 0; |
45 | ||
46 | #define HOSTFS_SUPER_MAGIC 0x00c0ffee | |
47 | ||
92e1d5be AV |
48 | static const struct inode_operations hostfs_iops; |
49 | static const struct inode_operations hostfs_dir_iops; | |
f5e54d6e | 50 | static const struct address_space_operations hostfs_link_aops; |
1da177e4 LT |
51 | |
52 | #ifndef MODULE | |
53 | static int __init hostfs_args(char *options, int *add) | |
54 | { | |
55 | char *ptr; | |
56 | ||
57 | ptr = strchr(options, ','); | |
84b3db04 | 58 | if (ptr != NULL) |
1da177e4 | 59 | *ptr++ = '\0'; |
84b3db04 | 60 | if (*options != '\0') |
1da177e4 LT |
61 | root_ino = options; |
62 | ||
63 | options = ptr; | |
84b3db04 | 64 | while (options) { |
1da177e4 | 65 | ptr = strchr(options, ','); |
84b3db04 | 66 | if (ptr != NULL) |
1da177e4 | 67 | *ptr++ = '\0'; |
84b3db04 JD |
68 | if (*options != '\0') { |
69 | if (!strcmp(options, "append")) | |
1da177e4 LT |
70 | append = 1; |
71 | else printf("hostfs_args - unsupported option - %s\n", | |
72 | options); | |
73 | } | |
74 | options = ptr; | |
75 | } | |
f1adc05e | 76 | return 0; |
1da177e4 LT |
77 | } |
78 | ||
79 | __uml_setup("hostfs=", hostfs_args, | |
80 | "hostfs=<root dir>,<flags>,...\n" | |
81 | " This is used to set hostfs parameters. The root directory argument\n" | |
82 | " is used to confine all hostfs mounts to within the specified directory\n" | |
83 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
84 | " mount anything on the host that's accessible to the user that's running\n" | |
85 | " it.\n" | |
86 | " The only flag currently supported is 'append', which specifies that all\n" | |
87 | " files opened by hostfs will be opened in append mode.\n\n" | |
88 | ); | |
89 | #endif | |
90 | ||
91 | static char *dentry_name(struct dentry *dentry, int extra) | |
92 | { | |
93 | struct dentry *parent; | |
94 | char *root, *name; | |
95 | int len; | |
96 | ||
97 | len = 0; | |
98 | parent = dentry; | |
84b3db04 | 99 | while (parent->d_parent != parent) { |
1da177e4 LT |
100 | len += parent->d_name.len + 1; |
101 | parent = parent->d_parent; | |
102 | } | |
103 | ||
104 | root = HOSTFS_I(parent->d_inode)->host_filename; | |
105 | len += strlen(root); | |
106 | name = kmalloc(len + extra + 1, GFP_KERNEL); | |
84b3db04 | 107 | if (name == NULL) |
f1adc05e | 108 | return NULL; |
1da177e4 LT |
109 | |
110 | name[len] = '\0'; | |
111 | parent = dentry; | |
84b3db04 | 112 | while (parent->d_parent != parent) { |
1da177e4 LT |
113 | len -= parent->d_name.len + 1; |
114 | name[len] = '/'; | |
115 | strncpy(&name[len + 1], parent->d_name.name, | |
116 | parent->d_name.len); | |
117 | parent = parent->d_parent; | |
118 | } | |
119 | strncpy(name, root, strlen(root)); | |
f1adc05e | 120 | return name; |
1da177e4 LT |
121 | } |
122 | ||
123 | static char *inode_name(struct inode *ino, int extra) | |
124 | { | |
125 | struct dentry *dentry; | |
126 | ||
127 | dentry = list_entry(ino->i_dentry.next, struct dentry, d_alias); | |
f1adc05e | 128 | return dentry_name(dentry, extra); |
1da177e4 LT |
129 | } |
130 | ||
131 | static int read_name(struct inode *ino, char *name) | |
132 | { | |
84b3db04 JD |
133 | /* |
134 | * The non-int inode fields are copied into ints by stat_file and | |
1da177e4 LT |
135 | * then copied into the inode because passing the actual pointers |
136 | * in and having them treated as int * breaks on big-endian machines | |
137 | */ | |
138 | int err; | |
139 | int i_mode, i_nlink, i_blksize; | |
140 | unsigned long long i_size; | |
141 | unsigned long long i_ino; | |
142 | unsigned long long i_blocks; | |
143 | ||
144 | err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid, | |
145 | &ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime, | |
5822b7fa | 146 | &ino->i_ctime, &i_blksize, &i_blocks, -1); |
84b3db04 | 147 | if (err) |
f1adc05e | 148 | return err; |
1da177e4 LT |
149 | |
150 | ino->i_ino = i_ino; | |
151 | ino->i_mode = i_mode; | |
152 | ino->i_nlink = i_nlink; | |
153 | ino->i_size = i_size; | |
1da177e4 | 154 | ino->i_blocks = i_blocks; |
f1adc05e | 155 | return 0; |
1da177e4 LT |
156 | } |
157 | ||
158 | static char *follow_link(char *link) | |
159 | { | |
160 | int len, n; | |
161 | char *name, *resolved, *end; | |
162 | ||
163 | len = 64; | |
84b3db04 | 164 | while (1) { |
1da177e4 LT |
165 | n = -ENOMEM; |
166 | name = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 167 | if (name == NULL) |
1da177e4 LT |
168 | goto out; |
169 | ||
170 | n = do_readlink(link, name, len); | |
84b3db04 | 171 | if (n < len) |
1da177e4 LT |
172 | break; |
173 | len *= 2; | |
174 | kfree(name); | |
175 | } | |
84b3db04 | 176 | if (n < 0) |
1da177e4 LT |
177 | goto out_free; |
178 | ||
84b3db04 | 179 | if (*name == '/') |
f1adc05e | 180 | return name; |
1da177e4 LT |
181 | |
182 | end = strrchr(link, '/'); | |
84b3db04 | 183 | if (end == NULL) |
f1adc05e | 184 | return name; |
1da177e4 LT |
185 | |
186 | *(end + 1) = '\0'; | |
187 | len = strlen(link) + strlen(name) + 1; | |
188 | ||
189 | resolved = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 190 | if (resolved == NULL) { |
1da177e4 LT |
191 | n = -ENOMEM; |
192 | goto out_free; | |
193 | } | |
194 | ||
195 | sprintf(resolved, "%s%s", link, name); | |
196 | kfree(name); | |
197 | kfree(link); | |
f1adc05e | 198 | return resolved; |
1da177e4 LT |
199 | |
200 | out_free: | |
201 | kfree(name); | |
202 | out: | |
f1adc05e | 203 | return ERR_PTR(n); |
1da177e4 LT |
204 | } |
205 | ||
0a370e5d | 206 | static int hostfs_read_inode(struct inode *ino) |
1da177e4 LT |
207 | { |
208 | char *name; | |
209 | int err = 0; | |
210 | ||
84b3db04 JD |
211 | /* |
212 | * Unfortunately, we are called from iget() when we don't have a dentry | |
1da177e4 LT |
213 | * allocated yet. |
214 | */ | |
84b3db04 | 215 | if (list_empty(&ino->i_dentry)) |
1da177e4 LT |
216 | goto out; |
217 | ||
218 | err = -ENOMEM; | |
219 | name = inode_name(ino, 0); | |
84b3db04 | 220 | if (name == NULL) |
1da177e4 LT |
221 | goto out; |
222 | ||
84b3db04 | 223 | if (file_type(name, NULL, NULL) == OS_TYPE_SYMLINK) { |
1da177e4 | 224 | name = follow_link(name); |
84b3db04 | 225 | if (IS_ERR(name)) { |
1da177e4 LT |
226 | err = PTR_ERR(name); |
227 | goto out; | |
228 | } | |
229 | } | |
230 | ||
231 | err = read_name(ino, name); | |
232 | kfree(name); | |
233 | out: | |
f1adc05e | 234 | return err; |
1da177e4 LT |
235 | } |
236 | ||
0a370e5d DH |
237 | static struct inode *hostfs_iget(struct super_block *sb) |
238 | { | |
239 | struct inode *inode; | |
240 | long ret; | |
241 | ||
242 | inode = iget_locked(sb, 0); | |
243 | if (!inode) | |
244 | return ERR_PTR(-ENOMEM); | |
245 | if (inode->i_state & I_NEW) { | |
246 | ret = hostfs_read_inode(inode); | |
247 | if (ret < 0) { | |
248 | iget_failed(inode); | |
249 | return ERR_PTR(ret); | |
250 | } | |
251 | unlock_new_inode(inode); | |
252 | } | |
253 | return inode; | |
254 | } | |
255 | ||
726c3342 | 256 | int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 | 257 | { |
84b3db04 JD |
258 | /* |
259 | * do_statfs uses struct statfs64 internally, but the linux kernel | |
1da177e4 LT |
260 | * struct statfs still has 32-bit versions for most of these fields, |
261 | * so we convert them here | |
262 | */ | |
263 | int err; | |
264 | long long f_blocks; | |
265 | long long f_bfree; | |
266 | long long f_bavail; | |
267 | long long f_files; | |
268 | long long f_ffree; | |
269 | ||
726c3342 | 270 | err = do_statfs(HOSTFS_I(dentry->d_sb->s_root->d_inode)->host_filename, |
1da177e4 LT |
271 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
272 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
273 | &sf->f_namelen, sf->f_spare); | |
84b3db04 | 274 | if (err) |
f1adc05e | 275 | return err; |
1da177e4 LT |
276 | sf->f_blocks = f_blocks; |
277 | sf->f_bfree = f_bfree; | |
278 | sf->f_bavail = f_bavail; | |
279 | sf->f_files = f_files; | |
280 | sf->f_ffree = f_ffree; | |
281 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
f1adc05e | 282 | return 0; |
1da177e4 LT |
283 | } |
284 | ||
285 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
286 | { | |
287 | struct hostfs_inode_info *hi; | |
288 | ||
289 | hi = kmalloc(sizeof(*hi), GFP_KERNEL); | |
84b3db04 | 290 | if (hi == NULL) |
f1adc05e | 291 | return NULL; |
1da177e4 LT |
292 | |
293 | *hi = ((struct hostfs_inode_info) { .host_filename = NULL, | |
294 | .fd = -1, | |
295 | .mode = 0 }); | |
296 | inode_init_once(&hi->vfs_inode); | |
f1adc05e | 297 | return &hi->vfs_inode; |
1da177e4 LT |
298 | } |
299 | ||
300 | static void hostfs_delete_inode(struct inode *inode) | |
301 | { | |
fef26658 | 302 | truncate_inode_pages(&inode->i_data, 0); |
84b3db04 | 303 | if (HOSTFS_I(inode)->fd != -1) { |
1da177e4 LT |
304 | close_file(&HOSTFS_I(inode)->fd); |
305 | HOSTFS_I(inode)->fd = -1; | |
306 | } | |
307 | clear_inode(inode); | |
308 | } | |
309 | ||
310 | static void hostfs_destroy_inode(struct inode *inode) | |
311 | { | |
f99d49ad | 312 | kfree(HOSTFS_I(inode)->host_filename); |
1da177e4 | 313 | |
84b3db04 JD |
314 | /* |
315 | * XXX: This should not happen, probably. The check is here for | |
316 | * additional safety. | |
317 | */ | |
318 | if (HOSTFS_I(inode)->fd != -1) { | |
1da177e4 LT |
319 | close_file(&HOSTFS_I(inode)->fd); |
320 | printk(KERN_DEBUG "Closing host fd in .destroy_inode\n"); | |
321 | } | |
322 | ||
323 | kfree(HOSTFS_I(inode)); | |
324 | } | |
325 | ||
dd2cc4df MS |
326 | static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs) |
327 | { | |
328 | struct inode *root = vfs->mnt_sb->s_root->d_inode; | |
329 | const char *root_path = HOSTFS_I(root)->host_filename; | |
330 | size_t offset = strlen(root_ino) + 1; | |
331 | ||
332 | if (strlen(root_path) > offset) | |
333 | seq_printf(seq, ",%s", root_path + offset); | |
334 | ||
335 | return 0; | |
336 | } | |
337 | ||
ee9b6d61 | 338 | static const struct super_operations hostfs_sbops = { |
1da177e4 LT |
339 | .alloc_inode = hostfs_alloc_inode, |
340 | .drop_inode = generic_delete_inode, | |
341 | .delete_inode = hostfs_delete_inode, | |
342 | .destroy_inode = hostfs_destroy_inode, | |
1da177e4 | 343 | .statfs = hostfs_statfs, |
dd2cc4df | 344 | .show_options = hostfs_show_options, |
1da177e4 LT |
345 | }; |
346 | ||
347 | int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) | |
348 | { | |
349 | void *dir; | |
350 | char *name; | |
351 | unsigned long long next, ino; | |
352 | int error, len; | |
353 | ||
680b0da9 | 354 | name = dentry_name(file->f_path.dentry, 0); |
84b3db04 | 355 | if (name == NULL) |
f1adc05e | 356 | return -ENOMEM; |
1da177e4 LT |
357 | dir = open_dir(name, &error); |
358 | kfree(name); | |
84b3db04 | 359 | if (dir == NULL) |
f1adc05e | 360 | return -error; |
1da177e4 | 361 | next = file->f_pos; |
84b3db04 | 362 | while ((name = read_dir(dir, &next, &ino, &len)) != NULL) { |
1da177e4 LT |
363 | error = (*filldir)(ent, name, len, file->f_pos, |
364 | ino, DT_UNKNOWN); | |
84b3db04 | 365 | if (error) break; |
1da177e4 LT |
366 | file->f_pos = next; |
367 | } | |
368 | close_dir(dir); | |
f1adc05e | 369 | return 0; |
1da177e4 LT |
370 | } |
371 | ||
372 | int hostfs_file_open(struct inode *ino, struct file *file) | |
373 | { | |
374 | char *name; | |
375 | int mode = 0, r = 0, w = 0, fd; | |
376 | ||
377 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 378 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 379 | return 0; |
1da177e4 | 380 | |
84b3db04 JD |
381 | /* |
382 | * The file may already have been opened, but with the wrong access, | |
1da177e4 LT |
383 | * so this resets things and reopens the file with the new access. |
384 | */ | |
84b3db04 | 385 | if (HOSTFS_I(ino)->fd != -1) { |
1da177e4 LT |
386 | close_file(&HOSTFS_I(ino)->fd); |
387 | HOSTFS_I(ino)->fd = -1; | |
388 | } | |
389 | ||
390 | HOSTFS_I(ino)->mode |= mode; | |
84b3db04 | 391 | if (HOSTFS_I(ino)->mode & FMODE_READ) |
1da177e4 | 392 | r = 1; |
84b3db04 | 393 | if (HOSTFS_I(ino)->mode & FMODE_WRITE) |
1da177e4 | 394 | w = 1; |
84b3db04 | 395 | if (w) |
1da177e4 LT |
396 | r = 1; |
397 | ||
680b0da9 | 398 | name = dentry_name(file->f_path.dentry, 0); |
84b3db04 | 399 | if (name == NULL) |
f1adc05e | 400 | return -ENOMEM; |
1da177e4 LT |
401 | |
402 | fd = open_file(name, r, w, append); | |
403 | kfree(name); | |
84b3db04 | 404 | if (fd < 0) |
f1adc05e | 405 | return fd; |
1da177e4 LT |
406 | FILE_HOSTFS_I(file)->fd = fd; |
407 | ||
f1adc05e | 408 | return 0; |
1da177e4 LT |
409 | } |
410 | ||
411 | int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync) | |
412 | { | |
a2d76bd8 | 413 | return fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync); |
1da177e4 LT |
414 | } |
415 | ||
4b6f5d20 | 416 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 417 | .llseek = generic_file_llseek, |
543ade1f | 418 | .read = do_sync_read, |
5ffc4ef4 | 419 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
420 | .aio_read = generic_file_aio_read, |
421 | .aio_write = generic_file_aio_write, | |
543ade1f | 422 | .write = do_sync_write, |
1da177e4 LT |
423 | .mmap = generic_file_mmap, |
424 | .open = hostfs_file_open, | |
425 | .release = NULL, | |
426 | .fsync = hostfs_fsync, | |
427 | }; | |
428 | ||
4b6f5d20 | 429 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
430 | .llseek = generic_file_llseek, |
431 | .readdir = hostfs_readdir, | |
432 | .read = generic_read_dir, | |
433 | }; | |
434 | ||
435 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
436 | { | |
437 | struct address_space *mapping = page->mapping; | |
438 | struct inode *inode = mapping->host; | |
439 | char *buffer; | |
440 | unsigned long long base; | |
441 | int count = PAGE_CACHE_SIZE; | |
442 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
443 | int err; | |
444 | ||
445 | if (page->index >= end_index) | |
446 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
447 | ||
448 | buffer = kmap(page); | |
449 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
450 | ||
451 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 452 | if (err != count) { |
1da177e4 LT |
453 | ClearPageUptodate(page); |
454 | goto out; | |
455 | } | |
456 | ||
457 | if (base > inode->i_size) | |
458 | inode->i_size = base; | |
459 | ||
460 | if (PageError(page)) | |
461 | ClearPageError(page); | |
462 | err = 0; | |
463 | ||
464 | out: | |
465 | kunmap(page); | |
466 | ||
467 | unlock_page(page); | |
468 | return err; | |
469 | } | |
470 | ||
471 | int hostfs_readpage(struct file *file, struct page *page) | |
472 | { | |
473 | char *buffer; | |
474 | long long start; | |
475 | int err = 0; | |
476 | ||
477 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
478 | buffer = kmap(page); | |
479 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
480 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
481 | if (err < 0) |
482 | goto out; | |
1da177e4 LT |
483 | |
484 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
485 | ||
486 | flush_dcache_page(page); | |
487 | SetPageUptodate(page); | |
488 | if (PageError(page)) ClearPageError(page); | |
489 | err = 0; | |
490 | out: | |
491 | kunmap(page); | |
492 | unlock_page(page); | |
f1adc05e | 493 | return err; |
1da177e4 LT |
494 | } |
495 | ||
ae361ff4 NP |
496 | int hostfs_write_begin(struct file *file, struct address_space *mapping, |
497 | loff_t pos, unsigned len, unsigned flags, | |
498 | struct page **pagep, void **fsdata) | |
1da177e4 | 499 | { |
ae361ff4 | 500 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 501 | |
ae361ff4 NP |
502 | *pagep = __grab_cache_page(mapping, index); |
503 | if (!*pagep) | |
504 | return -ENOMEM; | |
505 | return 0; | |
1da177e4 LT |
506 | } |
507 | ||
ae361ff4 NP |
508 | int hostfs_write_end(struct file *file, struct address_space *mapping, |
509 | loff_t pos, unsigned len, unsigned copied, | |
510 | struct page *page, void *fsdata) | |
1da177e4 | 511 | { |
1da177e4 | 512 | struct inode *inode = mapping->host; |
ae361ff4 NP |
513 | void *buffer; |
514 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
515 | int err; | |
1da177e4 | 516 | |
1da177e4 | 517 | buffer = kmap(page); |
ae361ff4 NP |
518 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
519 | kunmap(page); | |
30f04a4e | 520 | |
ae361ff4 NP |
521 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
522 | SetPageUptodate(page); | |
30f04a4e | 523 | |
84b3db04 JD |
524 | /* |
525 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
526 | * i_size against the last byte written. |
527 | */ | |
528 | if (err > 0 && (pos > inode->i_size)) | |
529 | inode->i_size = pos; | |
530 | unlock_page(page); | |
531 | page_cache_release(page); | |
1da177e4 | 532 | |
f1adc05e | 533 | return err; |
1da177e4 LT |
534 | } |
535 | ||
f5e54d6e | 536 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
537 | .writepage = hostfs_writepage, |
538 | .readpage = hostfs_readpage, | |
ffa0aea6 | 539 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
540 | .write_begin = hostfs_write_begin, |
541 | .write_end = hostfs_write_end, | |
1da177e4 LT |
542 | }; |
543 | ||
544 | static int init_inode(struct inode *inode, struct dentry *dentry) | |
545 | { | |
546 | char *name; | |
547 | int type, err = -ENOMEM; | |
548 | int maj, min; | |
549 | dev_t rdev = 0; | |
550 | ||
84b3db04 | 551 | if (dentry) { |
1da177e4 | 552 | name = dentry_name(dentry, 0); |
84b3db04 | 553 | if (name == NULL) |
1da177e4 LT |
554 | goto out; |
555 | type = file_type(name, &maj, &min); | |
84b3db04 | 556 | /* Reencode maj and min with the kernel encoding.*/ |
1da177e4 LT |
557 | rdev = MKDEV(maj, min); |
558 | kfree(name); | |
559 | } | |
560 | else type = OS_TYPE_DIR; | |
561 | ||
562 | err = 0; | |
84b3db04 | 563 | if (type == OS_TYPE_SYMLINK) |
1da177e4 | 564 | inode->i_op = &page_symlink_inode_operations; |
84b3db04 | 565 | else if (type == OS_TYPE_DIR) |
1da177e4 LT |
566 | inode->i_op = &hostfs_dir_iops; |
567 | else inode->i_op = &hostfs_iops; | |
568 | ||
84b3db04 | 569 | if (type == OS_TYPE_DIR) inode->i_fop = &hostfs_dir_fops; |
1da177e4 LT |
570 | else inode->i_fop = &hostfs_file_fops; |
571 | ||
84b3db04 | 572 | if (type == OS_TYPE_SYMLINK) |
1da177e4 LT |
573 | inode->i_mapping->a_ops = &hostfs_link_aops; |
574 | else inode->i_mapping->a_ops = &hostfs_aops; | |
575 | ||
576 | switch (type) { | |
577 | case OS_TYPE_CHARDEV: | |
578 | init_special_inode(inode, S_IFCHR, rdev); | |
579 | break; | |
580 | case OS_TYPE_BLOCKDEV: | |
581 | init_special_inode(inode, S_IFBLK, rdev); | |
582 | break; | |
583 | case OS_TYPE_FIFO: | |
584 | init_special_inode(inode, S_IFIFO, 0); | |
585 | break; | |
586 | case OS_TYPE_SOCK: | |
587 | init_special_inode(inode, S_IFSOCK, 0); | |
588 | break; | |
589 | } | |
590 | out: | |
f1adc05e | 591 | return err; |
1da177e4 LT |
592 | } |
593 | ||
594 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
84b3db04 | 595 | struct nameidata *nd) |
1da177e4 LT |
596 | { |
597 | struct inode *inode; | |
598 | char *name; | |
599 | int error, fd; | |
600 | ||
0a370e5d DH |
601 | inode = hostfs_iget(dir->i_sb); |
602 | if (IS_ERR(inode)) { | |
603 | error = PTR_ERR(inode); | |
84b3db04 | 604 | goto out; |
0a370e5d | 605 | } |
1da177e4 LT |
606 | |
607 | error = init_inode(inode, dentry); | |
84b3db04 | 608 | if (error) |
1da177e4 LT |
609 | goto out_put; |
610 | ||
611 | error = -ENOMEM; | |
612 | name = dentry_name(dentry, 0); | |
84b3db04 | 613 | if (name == NULL) |
1da177e4 LT |
614 | goto out_put; |
615 | ||
616 | fd = file_create(name, | |
617 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
618 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
619 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
84b3db04 | 620 | if (fd < 0) |
1da177e4 LT |
621 | error = fd; |
622 | else error = read_name(inode, name); | |
623 | ||
624 | kfree(name); | |
84b3db04 | 625 | if (error) |
1da177e4 LT |
626 | goto out_put; |
627 | ||
628 | HOSTFS_I(inode)->fd = fd; | |
629 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
630 | d_instantiate(dentry, inode); | |
f1adc05e | 631 | return 0; |
1da177e4 LT |
632 | |
633 | out_put: | |
634 | iput(inode); | |
635 | out: | |
f1adc05e | 636 | return error; |
1da177e4 LT |
637 | } |
638 | ||
639 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
f1adc05e | 640 | struct nameidata *nd) |
1da177e4 LT |
641 | { |
642 | struct inode *inode; | |
643 | char *name; | |
644 | int err; | |
645 | ||
0a370e5d DH |
646 | inode = hostfs_iget(ino->i_sb); |
647 | if (IS_ERR(inode)) { | |
648 | err = PTR_ERR(inode); | |
1da177e4 | 649 | goto out; |
0a370e5d | 650 | } |
1da177e4 LT |
651 | |
652 | err = init_inode(inode, dentry); | |
84b3db04 | 653 | if (err) |
1da177e4 LT |
654 | goto out_put; |
655 | ||
656 | err = -ENOMEM; | |
657 | name = dentry_name(dentry, 0); | |
84b3db04 | 658 | if (name == NULL) |
1da177e4 LT |
659 | goto out_put; |
660 | ||
661 | err = read_name(inode, name); | |
662 | kfree(name); | |
84b3db04 | 663 | if (err == -ENOENT) { |
1da177e4 LT |
664 | iput(inode); |
665 | inode = NULL; | |
666 | } | |
84b3db04 | 667 | else if (err) |
1da177e4 LT |
668 | goto out_put; |
669 | ||
670 | d_add(dentry, inode); | |
671 | dentry->d_op = &hostfs_dentry_ops; | |
f1adc05e | 672 | return NULL; |
1da177e4 LT |
673 | |
674 | out_put: | |
675 | iput(inode); | |
676 | out: | |
f1adc05e | 677 | return ERR_PTR(err); |
1da177e4 LT |
678 | } |
679 | ||
680 | static char *inode_dentry_name(struct inode *ino, struct dentry *dentry) | |
681 | { | |
f1adc05e | 682 | char *file; |
1da177e4 LT |
683 | int len; |
684 | ||
685 | file = inode_name(ino, dentry->d_name.len + 1); | |
84b3db04 | 686 | if (file == NULL) |
f1adc05e JD |
687 | return NULL; |
688 | strcat(file, "/"); | |
1da177e4 | 689 | len = strlen(file); |
f1adc05e | 690 | strncat(file, dentry->d_name.name, dentry->d_name.len); |
1da177e4 | 691 | file[len + dentry->d_name.len] = '\0'; |
f1adc05e | 692 | return file; |
1da177e4 LT |
693 | } |
694 | ||
695 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) | |
696 | { | |
f1adc05e JD |
697 | char *from_name, *to_name; |
698 | int err; | |
1da177e4 | 699 | |
84b3db04 | 700 | if ((from_name = inode_dentry_name(ino, from)) == NULL) |
f1adc05e JD |
701 | return -ENOMEM; |
702 | to_name = dentry_name(to, 0); | |
84b3db04 | 703 | if (to_name == NULL) { |
1da177e4 | 704 | kfree(from_name); |
f1adc05e | 705 | return -ENOMEM; |
1da177e4 | 706 | } |
f1adc05e JD |
707 | err = link_file(to_name, from_name); |
708 | kfree(from_name); | |
709 | kfree(to_name); | |
710 | return err; | |
1da177e4 LT |
711 | } |
712 | ||
713 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
714 | { | |
715 | char *file; | |
716 | int err; | |
717 | ||
84b3db04 | 718 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 719 | return -ENOMEM; |
84b3db04 | 720 | if (append) |
f1adc05e | 721 | return -EPERM; |
1da177e4 LT |
722 | |
723 | err = unlink_file(file); | |
724 | kfree(file); | |
f1adc05e | 725 | return err; |
1da177e4 LT |
726 | } |
727 | ||
728 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
729 | { | |
730 | char *file; | |
731 | int err; | |
732 | ||
84b3db04 | 733 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 734 | return -ENOMEM; |
1da177e4 LT |
735 | err = make_symlink(file, to); |
736 | kfree(file); | |
f1adc05e | 737 | return err; |
1da177e4 LT |
738 | } |
739 | ||
740 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
741 | { | |
742 | char *file; | |
743 | int err; | |
744 | ||
84b3db04 | 745 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 746 | return -ENOMEM; |
1da177e4 LT |
747 | err = do_mkdir(file, mode); |
748 | kfree(file); | |
f1adc05e | 749 | return err; |
1da177e4 LT |
750 | } |
751 | ||
752 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
753 | { | |
754 | char *file; | |
755 | int err; | |
756 | ||
84b3db04 | 757 | if ((file = inode_dentry_name(ino, dentry)) == NULL) |
f1adc05e | 758 | return -ENOMEM; |
1da177e4 LT |
759 | err = do_rmdir(file); |
760 | kfree(file); | |
f1adc05e | 761 | return err; |
1da177e4 LT |
762 | } |
763 | ||
764 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
765 | { | |
766 | struct inode *inode; | |
767 | char *name; | |
0a370e5d | 768 | int err; |
1da177e4 | 769 | |
0a370e5d DH |
770 | inode = hostfs_iget(dir->i_sb); |
771 | if (IS_ERR(inode)) { | |
772 | err = PTR_ERR(inode); | |
1da177e4 | 773 | goto out; |
0a370e5d | 774 | } |
1da177e4 LT |
775 | |
776 | err = init_inode(inode, dentry); | |
84b3db04 | 777 | if (err) |
1da177e4 LT |
778 | goto out_put; |
779 | ||
780 | err = -ENOMEM; | |
781 | name = dentry_name(dentry, 0); | |
84b3db04 | 782 | if (name == NULL) |
1da177e4 LT |
783 | goto out_put; |
784 | ||
785 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 786 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
84b3db04 | 787 | if (err) |
1da177e4 LT |
788 | goto out_free; |
789 | ||
790 | err = read_name(inode, name); | |
791 | kfree(name); | |
84b3db04 | 792 | if (err) |
1da177e4 LT |
793 | goto out_put; |
794 | ||
795 | d_instantiate(dentry, inode); | |
f1adc05e | 796 | return 0; |
1da177e4 LT |
797 | |
798 | out_free: | |
799 | kfree(name); | |
800 | out_put: | |
801 | iput(inode); | |
802 | out: | |
f1adc05e | 803 | return err; |
1da177e4 LT |
804 | } |
805 | ||
806 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
807 | struct inode *to_ino, struct dentry *to) | |
808 | { | |
809 | char *from_name, *to_name; | |
810 | int err; | |
811 | ||
84b3db04 | 812 | if ((from_name = inode_dentry_name(from_ino, from)) == NULL) |
f1adc05e | 813 | return -ENOMEM; |
84b3db04 | 814 | if ((to_name = inode_dentry_name(to_ino, to)) == NULL) { |
1da177e4 | 815 | kfree(from_name); |
f1adc05e | 816 | return -ENOMEM; |
1da177e4 LT |
817 | } |
818 | err = rename_file(from_name, to_name); | |
819 | kfree(from_name); | |
820 | kfree(to_name); | |
f1adc05e | 821 | return err; |
1da177e4 LT |
822 | } |
823 | ||
1da177e4 LT |
824 | int hostfs_permission(struct inode *ino, int desired, struct nameidata *nd) |
825 | { | |
826 | char *name; | |
827 | int r = 0, w = 0, x = 0, err; | |
828 | ||
829 | if (desired & MAY_READ) r = 1; | |
830 | if (desired & MAY_WRITE) w = 1; | |
831 | if (desired & MAY_EXEC) x = 1; | |
832 | name = inode_name(ino, 0); | |
f1adc05e JD |
833 | if (name == NULL) |
834 | return -ENOMEM; | |
1da177e4 LT |
835 | |
836 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 837 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
838 | err = 0; |
839 | else | |
840 | err = access_file(name, r, w, x); | |
841 | kfree(name); | |
84b3db04 | 842 | if (!err) |
1da177e4 LT |
843 | err = generic_permission(ino, desired, NULL); |
844 | return err; | |
845 | } | |
846 | ||
847 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
848 | { | |
849 | struct hostfs_iattr attrs; | |
850 | char *name; | |
851 | int err; | |
852 | ||
5822b7fa AB |
853 | int fd = HOSTFS_I(dentry->d_inode)->fd; |
854 | ||
1da177e4 LT |
855 | err = inode_change_ok(dentry->d_inode, attr); |
856 | if (err) | |
857 | return err; | |
858 | ||
84b3db04 | 859 | if (append) |
1da177e4 LT |
860 | attr->ia_valid &= ~ATTR_SIZE; |
861 | ||
862 | attrs.ia_valid = 0; | |
84b3db04 | 863 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
864 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
865 | attrs.ia_mode = attr->ia_mode; | |
866 | } | |
84b3db04 | 867 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 LT |
868 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
869 | attrs.ia_uid = attr->ia_uid; | |
870 | } | |
84b3db04 | 871 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 LT |
872 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
873 | attrs.ia_gid = attr->ia_gid; | |
874 | } | |
84b3db04 | 875 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
876 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
877 | attrs.ia_size = attr->ia_size; | |
878 | } | |
84b3db04 | 879 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
880 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
881 | attrs.ia_atime = attr->ia_atime; | |
882 | } | |
84b3db04 | 883 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
884 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
885 | attrs.ia_mtime = attr->ia_mtime; | |
886 | } | |
84b3db04 | 887 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
888 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
889 | attrs.ia_ctime = attr->ia_ctime; | |
890 | } | |
84b3db04 | 891 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
892 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
893 | } | |
84b3db04 | 894 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
895 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
896 | } | |
897 | name = dentry_name(dentry, 0); | |
84b3db04 | 898 | if (name == NULL) |
f1adc05e | 899 | return -ENOMEM; |
5822b7fa | 900 | err = set_attr(name, &attrs, fd); |
1da177e4 | 901 | kfree(name); |
84b3db04 | 902 | if (err) |
f1adc05e | 903 | return err; |
1da177e4 | 904 | |
f1adc05e | 905 | return inode_setattr(dentry->d_inode, attr); |
1da177e4 LT |
906 | } |
907 | ||
92e1d5be | 908 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
909 | .create = hostfs_create, |
910 | .link = hostfs_link, | |
911 | .unlink = hostfs_unlink, | |
912 | .symlink = hostfs_symlink, | |
913 | .mkdir = hostfs_mkdir, | |
914 | .rmdir = hostfs_rmdir, | |
915 | .mknod = hostfs_mknod, | |
916 | .rename = hostfs_rename, | |
1da177e4 LT |
917 | .permission = hostfs_permission, |
918 | .setattr = hostfs_setattr, | |
1da177e4 LT |
919 | }; |
920 | ||
92e1d5be | 921 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
922 | .create = hostfs_create, |
923 | .lookup = hostfs_lookup, | |
924 | .link = hostfs_link, | |
925 | .unlink = hostfs_unlink, | |
926 | .symlink = hostfs_symlink, | |
927 | .mkdir = hostfs_mkdir, | |
928 | .rmdir = hostfs_rmdir, | |
929 | .mknod = hostfs_mknod, | |
930 | .rename = hostfs_rename, | |
1da177e4 LT |
931 | .permission = hostfs_permission, |
932 | .setattr = hostfs_setattr, | |
1da177e4 LT |
933 | }; |
934 | ||
935 | int hostfs_link_readpage(struct file *file, struct page *page) | |
936 | { | |
937 | char *buffer, *name; | |
1da177e4 LT |
938 | int err; |
939 | ||
1da177e4 LT |
940 | buffer = kmap(page); |
941 | name = inode_name(page->mapping->host, 0); | |
84b3db04 | 942 | if (name == NULL) |
f1adc05e | 943 | return -ENOMEM; |
1da177e4 LT |
944 | err = do_readlink(name, buffer, PAGE_CACHE_SIZE); |
945 | kfree(name); | |
84b3db04 | 946 | if (err == PAGE_CACHE_SIZE) |
1da177e4 | 947 | err = -E2BIG; |
84b3db04 | 948 | else if (err > 0) { |
1da177e4 LT |
949 | flush_dcache_page(page); |
950 | SetPageUptodate(page); | |
951 | if (PageError(page)) ClearPageError(page); | |
952 | err = 0; | |
953 | } | |
954 | kunmap(page); | |
955 | unlock_page(page); | |
f1adc05e | 956 | return err; |
1da177e4 LT |
957 | } |
958 | ||
f5e54d6e | 959 | static const struct address_space_operations hostfs_link_aops = { |
1da177e4 LT |
960 | .readpage = hostfs_link_readpage, |
961 | }; | |
962 | ||
963 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
964 | { | |
965 | struct inode *root_inode; | |
75e8defb | 966 | char *host_root_path, *req_root = d; |
1da177e4 LT |
967 | int err; |
968 | ||
969 | sb->s_blocksize = 1024; | |
970 | sb->s_blocksize_bits = 10; | |
971 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
972 | sb->s_op = &hostfs_sbops; | |
973 | ||
a6eb0be6 | 974 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
975 | if (req_root == NULL) |
976 | req_root = ""; | |
1da177e4 LT |
977 | |
978 | err = -ENOMEM; | |
75e8defb PBG |
979 | host_root_path = kmalloc(strlen(root_ino) + 1 |
980 | + strlen(req_root) + 1, GFP_KERNEL); | |
84b3db04 | 981 | if (host_root_path == NULL) |
1da177e4 LT |
982 | goto out; |
983 | ||
75e8defb | 984 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 | 985 | |
0a370e5d DH |
986 | root_inode = hostfs_iget(sb); |
987 | if (IS_ERR(root_inode)) { | |
988 | err = PTR_ERR(root_inode); | |
1da177e4 | 989 | goto out_free; |
0a370e5d | 990 | } |
1da177e4 LT |
991 | |
992 | err = init_inode(root_inode, NULL); | |
84b3db04 | 993 | if (err) |
1da177e4 LT |
994 | goto out_put; |
995 | ||
75e8defb | 996 | HOSTFS_I(root_inode)->host_filename = host_root_path; |
84b3db04 JD |
997 | /* |
998 | * Avoid that in the error path, iput(root_inode) frees again | |
999 | * host_root_path through hostfs_destroy_inode! | |
1000 | */ | |
75e8defb | 1001 | host_root_path = NULL; |
1da177e4 LT |
1002 | |
1003 | err = -ENOMEM; | |
1004 | sb->s_root = d_alloc_root(root_inode); | |
84b3db04 | 1005 | if (sb->s_root == NULL) |
1da177e4 LT |
1006 | goto out_put; |
1007 | ||
0a370e5d | 1008 | err = hostfs_read_inode(root_inode); |
84b3db04 | 1009 | if (err) { |
f1adc05e JD |
1010 | /* No iput in this case because the dput does that for us */ |
1011 | dput(sb->s_root); | |
1012 | sb->s_root = NULL; | |
bca27113 | 1013 | goto out; |
f1adc05e | 1014 | } |
1da177e4 | 1015 | |
f1adc05e | 1016 | return 0; |
1da177e4 | 1017 | |
f1adc05e JD |
1018 | out_put: |
1019 | iput(root_inode); | |
1020 | out_free: | |
75e8defb | 1021 | kfree(host_root_path); |
f1adc05e JD |
1022 | out: |
1023 | return err; | |
1da177e4 LT |
1024 | } |
1025 | ||
454e2398 DH |
1026 | static int hostfs_read_sb(struct file_system_type *type, |
1027 | int flags, const char *dev_name, | |
1028 | void *data, struct vfsmount *mnt) | |
1da177e4 | 1029 | { |
454e2398 | 1030 | return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); |
1da177e4 LT |
1031 | } |
1032 | ||
1033 | static struct file_system_type hostfs_type = { | |
1034 | .owner = THIS_MODULE, | |
1035 | .name = "hostfs", | |
1036 | .get_sb = hostfs_read_sb, | |
1037 | .kill_sb = kill_anon_super, | |
1038 | .fs_flags = 0, | |
1039 | }; | |
1040 | ||
1041 | static int __init init_hostfs(void) | |
1042 | { | |
f1adc05e | 1043 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
1044 | } |
1045 | ||
1046 | static void __exit exit_hostfs(void) | |
1047 | { | |
1048 | unregister_filesystem(&hostfs_type); | |
1049 | } | |
1050 | ||
1051 | module_init(init_hostfs) | |
1052 | module_exit(exit_hostfs) | |
1053 | MODULE_LICENSE("GPL"); |