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0fd16957 HG |
1 | // SPDX-License-Identifier: MIT |
2 | /* | |
3 | * VirtualBox Guest Shared Folders support: Directory inode and file operations | |
4 | * | |
5 | * Copyright (C) 2006-2018 Oracle Corporation | |
6 | */ | |
7 | ||
8 | #include <linux/namei.h> | |
9 | #include <linux/vbox_utils.h> | |
10 | #include "vfsmod.h" | |
11 | ||
12 | static int vboxsf_dir_open(struct inode *inode, struct file *file) | |
13 | { | |
14 | struct vboxsf_sbi *sbi = VBOXSF_SBI(inode->i_sb); | |
15 | struct shfl_createparms params = {}; | |
16 | struct vboxsf_dir_info *sf_d; | |
17 | int err; | |
18 | ||
19 | sf_d = vboxsf_dir_info_alloc(); | |
20 | if (!sf_d) | |
21 | return -ENOMEM; | |
22 | ||
23 | params.handle = SHFL_HANDLE_NIL; | |
24 | params.create_flags = SHFL_CF_DIRECTORY | SHFL_CF_ACT_OPEN_IF_EXISTS | | |
25 | SHFL_CF_ACT_FAIL_IF_NEW | SHFL_CF_ACCESS_READ; | |
26 | ||
27 | err = vboxsf_create_at_dentry(file_dentry(file), ¶ms); | |
28 | if (err) | |
29 | goto err_free_dir_info; | |
30 | ||
31 | if (params.result != SHFL_FILE_EXISTS) { | |
32 | err = -ENOENT; | |
33 | goto err_close; | |
34 | } | |
35 | ||
36 | err = vboxsf_dir_read_all(sbi, sf_d, params.handle); | |
37 | if (err) | |
38 | goto err_close; | |
39 | ||
40 | vboxsf_close(sbi->root, params.handle); | |
41 | file->private_data = sf_d; | |
42 | return 0; | |
43 | ||
44 | err_close: | |
45 | vboxsf_close(sbi->root, params.handle); | |
46 | err_free_dir_info: | |
47 | vboxsf_dir_info_free(sf_d); | |
48 | return err; | |
49 | } | |
50 | ||
51 | static int vboxsf_dir_release(struct inode *inode, struct file *file) | |
52 | { | |
53 | if (file->private_data) | |
54 | vboxsf_dir_info_free(file->private_data); | |
55 | ||
56 | return 0; | |
57 | } | |
58 | ||
59 | static unsigned int vboxsf_get_d_type(u32 mode) | |
60 | { | |
61 | unsigned int d_type; | |
62 | ||
63 | switch (mode & SHFL_TYPE_MASK) { | |
64 | case SHFL_TYPE_FIFO: | |
65 | d_type = DT_FIFO; | |
66 | break; | |
67 | case SHFL_TYPE_DEV_CHAR: | |
68 | d_type = DT_CHR; | |
69 | break; | |
70 | case SHFL_TYPE_DIRECTORY: | |
71 | d_type = DT_DIR; | |
72 | break; | |
73 | case SHFL_TYPE_DEV_BLOCK: | |
74 | d_type = DT_BLK; | |
75 | break; | |
76 | case SHFL_TYPE_FILE: | |
77 | d_type = DT_REG; | |
78 | break; | |
79 | case SHFL_TYPE_SYMLINK: | |
80 | d_type = DT_LNK; | |
81 | break; | |
82 | case SHFL_TYPE_SOCKET: | |
83 | d_type = DT_SOCK; | |
84 | break; | |
85 | case SHFL_TYPE_WHITEOUT: | |
86 | d_type = DT_WHT; | |
87 | break; | |
88 | default: | |
89 | d_type = DT_UNKNOWN; | |
90 | break; | |
91 | } | |
92 | return d_type; | |
93 | } | |
94 | ||
95 | static bool vboxsf_dir_emit(struct file *dir, struct dir_context *ctx) | |
96 | { | |
97 | struct vboxsf_sbi *sbi = VBOXSF_SBI(file_inode(dir)->i_sb); | |
98 | struct vboxsf_dir_info *sf_d = dir->private_data; | |
99 | struct shfl_dirinfo *info; | |
100 | struct vboxsf_dir_buf *b; | |
101 | unsigned int d_type; | |
102 | loff_t i, cur = 0; | |
103 | ino_t fake_ino; | |
104 | void *end; | |
105 | int err; | |
106 | ||
107 | list_for_each_entry(b, &sf_d->info_list, head) { | |
108 | try_next_entry: | |
109 | if (ctx->pos >= cur + b->entries) { | |
110 | cur += b->entries; | |
111 | continue; | |
112 | } | |
113 | ||
114 | /* | |
115 | * Note the vboxsf_dir_info objects we are iterating over here | |
116 | * are variable sized, so the info pointer may end up being | |
117 | * unaligned. This is how we get the data from the host. | |
118 | * Since vboxsf is only supported on x86 machines this is not | |
119 | * a problem. | |
120 | */ | |
121 | for (i = 0, info = b->buf; i < ctx->pos - cur; i++) { | |
122 | end = &info->name.string.utf8[info->name.size]; | |
123 | /* Only happens if the host gives us corrupt data */ | |
124 | if (WARN_ON(end > (b->buf + b->used))) | |
125 | return false; | |
126 | info = end; | |
127 | } | |
128 | ||
129 | end = &info->name.string.utf8[info->name.size]; | |
130 | if (WARN_ON(end > (b->buf + b->used))) | |
131 | return false; | |
132 | ||
133 | /* Info now points to the right entry, emit it. */ | |
134 | d_type = vboxsf_get_d_type(info->info.attr.mode); | |
135 | ||
136 | /* | |
15f9f63f | 137 | * On 32-bit systems pos is 64-bit signed, while ino is 32-bit |
0fd16957 HG |
138 | * unsigned so fake_ino may overflow, check for this. |
139 | */ | |
140 | if ((ino_t)(ctx->pos + 1) != (u64)(ctx->pos + 1)) { | |
141 | vbg_err("vboxsf: fake ino overflow, truncating dir\n"); | |
142 | return false; | |
143 | } | |
144 | fake_ino = ctx->pos + 1; | |
145 | ||
146 | if (sbi->nls) { | |
147 | char d_name[NAME_MAX]; | |
148 | ||
149 | err = vboxsf_nlscpy(sbi, d_name, NAME_MAX, | |
150 | info->name.string.utf8, | |
151 | info->name.length); | |
152 | if (err) { | |
153 | /* skip erroneous entry and proceed */ | |
154 | ctx->pos += 1; | |
155 | goto try_next_entry; | |
156 | } | |
157 | ||
158 | return dir_emit(ctx, d_name, strlen(d_name), | |
159 | fake_ino, d_type); | |
160 | } | |
161 | ||
162 | return dir_emit(ctx, info->name.string.utf8, info->name.length, | |
163 | fake_ino, d_type); | |
164 | } | |
165 | ||
166 | return false; | |
167 | } | |
168 | ||
169 | static int vboxsf_dir_iterate(struct file *dir, struct dir_context *ctx) | |
170 | { | |
171 | bool emitted; | |
172 | ||
173 | do { | |
174 | emitted = vboxsf_dir_emit(dir, ctx); | |
175 | if (emitted) | |
176 | ctx->pos += 1; | |
177 | } while (emitted); | |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | const struct file_operations vboxsf_dir_fops = { | |
183 | .open = vboxsf_dir_open, | |
184 | .iterate = vboxsf_dir_iterate, | |
185 | .release = vboxsf_dir_release, | |
186 | .read = generic_read_dir, | |
187 | .llseek = generic_file_llseek, | |
188 | }; | |
189 | ||
190 | /* | |
191 | * This is called during name resolution/lookup to check if the @dentry in | |
192 | * the cache is still valid. the job is handled by vboxsf_inode_revalidate. | |
193 | */ | |
194 | static int vboxsf_dentry_revalidate(struct dentry *dentry, unsigned int flags) | |
195 | { | |
196 | if (flags & LOOKUP_RCU) | |
197 | return -ECHILD; | |
198 | ||
199 | if (d_really_is_positive(dentry)) | |
200 | return vboxsf_inode_revalidate(dentry) == 0; | |
201 | else | |
202 | return vboxsf_stat_dentry(dentry, NULL) == -ENOENT; | |
203 | } | |
204 | ||
205 | const struct dentry_operations vboxsf_dentry_ops = { | |
206 | .d_revalidate = vboxsf_dentry_revalidate | |
207 | }; | |
208 | ||
209 | /* iops */ | |
210 | ||
211 | static struct dentry *vboxsf_dir_lookup(struct inode *parent, | |
212 | struct dentry *dentry, | |
213 | unsigned int flags) | |
214 | { | |
215 | struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb); | |
216 | struct shfl_fsobjinfo fsinfo; | |
217 | struct inode *inode; | |
218 | int err; | |
219 | ||
220 | dentry->d_time = jiffies; | |
221 | ||
222 | err = vboxsf_stat_dentry(dentry, &fsinfo); | |
223 | if (err) { | |
224 | inode = (err == -ENOENT) ? NULL : ERR_PTR(err); | |
225 | } else { | |
226 | inode = vboxsf_new_inode(parent->i_sb); | |
227 | if (!IS_ERR(inode)) | |
e98f93e7 | 228 | vboxsf_init_inode(sbi, inode, &fsinfo, false); |
0fd16957 HG |
229 | } |
230 | ||
231 | return d_splice_alias(inode, dentry); | |
232 | } | |
233 | ||
234 | static int vboxsf_dir_instantiate(struct inode *parent, struct dentry *dentry, | |
235 | struct shfl_fsobjinfo *info) | |
236 | { | |
237 | struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb); | |
238 | struct vboxsf_inode *sf_i; | |
239 | struct inode *inode; | |
240 | ||
241 | inode = vboxsf_new_inode(parent->i_sb); | |
242 | if (IS_ERR(inode)) | |
243 | return PTR_ERR(inode); | |
244 | ||
245 | sf_i = VBOXSF_I(inode); | |
246 | /* The host may have given us different attr then requested */ | |
247 | sf_i->force_restat = 1; | |
e98f93e7 | 248 | vboxsf_init_inode(sbi, inode, info, false); |
0fd16957 HG |
249 | |
250 | d_instantiate(dentry, inode); | |
251 | ||
252 | return 0; | |
253 | } | |
254 | ||
255 | static int vboxsf_dir_create(struct inode *parent, struct dentry *dentry, | |
ab0c2968 | 256 | umode_t mode, bool is_dir, bool excl, u64 *handle_ret) |
0fd16957 HG |
257 | { |
258 | struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent); | |
259 | struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb); | |
260 | struct shfl_createparms params = {}; | |
261 | int err; | |
262 | ||
263 | params.handle = SHFL_HANDLE_NIL; | |
cc3ddee9 HG |
264 | params.create_flags = SHFL_CF_ACT_CREATE_IF_NEW | SHFL_CF_ACCESS_READWRITE; |
265 | if (is_dir) | |
266 | params.create_flags |= SHFL_CF_DIRECTORY; | |
267 | if (excl) | |
268 | params.create_flags |= SHFL_CF_ACT_FAIL_IF_EXISTS; | |
269 | ||
0fd16957 HG |
270 | params.info.attr.mode = (mode & 0777) | |
271 | (is_dir ? SHFL_TYPE_DIRECTORY : SHFL_TYPE_FILE); | |
272 | params.info.attr.additional = SHFLFSOBJATTRADD_NOTHING; | |
273 | ||
274 | err = vboxsf_create_at_dentry(dentry, ¶ms); | |
275 | if (err) | |
276 | return err; | |
277 | ||
278 | if (params.result != SHFL_FILE_CREATED) | |
279 | return -EPERM; | |
280 | ||
0fd16957 HG |
281 | err = vboxsf_dir_instantiate(parent, dentry, ¶ms.info); |
282 | if (err) | |
ab0c2968 | 283 | goto out; |
0fd16957 HG |
284 | |
285 | /* parent directory access/change time changed */ | |
286 | sf_parent_i->force_restat = 1; | |
287 | ||
ab0c2968 HG |
288 | out: |
289 | if (err == 0 && handle_ret) | |
290 | *handle_ret = params.handle; | |
291 | else | |
292 | vboxsf_close(sbi->root, params.handle); | |
293 | ||
294 | return err; | |
0fd16957 HG |
295 | } |
296 | ||
6c960e68 | 297 | static int vboxsf_dir_mkfile(struct mnt_idmap *idmap, |
549c7297 | 298 | struct inode *parent, struct dentry *dentry, |
0fd16957 HG |
299 | umode_t mode, bool excl) |
300 | { | |
ab0c2968 | 301 | return vboxsf_dir_create(parent, dentry, mode, false, excl, NULL); |
0fd16957 HG |
302 | } |
303 | ||
c54bd91e | 304 | static int vboxsf_dir_mkdir(struct mnt_idmap *idmap, |
549c7297 | 305 | struct inode *parent, struct dentry *dentry, |
0fd16957 HG |
306 | umode_t mode) |
307 | { | |
ab0c2968 | 308 | return vboxsf_dir_create(parent, dentry, mode, true, true, NULL); |
0fd16957 HG |
309 | } |
310 | ||
52dfd86a HG |
311 | static int vboxsf_dir_atomic_open(struct inode *parent, struct dentry *dentry, |
312 | struct file *file, unsigned int flags, umode_t mode) | |
313 | { | |
314 | struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb); | |
315 | struct vboxsf_handle *sf_handle; | |
316 | struct dentry *res = NULL; | |
317 | u64 handle; | |
318 | int err; | |
319 | ||
320 | if (d_in_lookup(dentry)) { | |
321 | res = vboxsf_dir_lookup(parent, dentry, 0); | |
322 | if (IS_ERR(res)) | |
323 | return PTR_ERR(res); | |
324 | ||
325 | if (res) | |
326 | dentry = res; | |
327 | } | |
328 | ||
329 | /* Only creates */ | |
330 | if (!(flags & O_CREAT) || d_really_is_positive(dentry)) | |
331 | return finish_no_open(file, res); | |
332 | ||
333 | err = vboxsf_dir_create(parent, dentry, mode, false, flags & O_EXCL, &handle); | |
334 | if (err) | |
335 | goto out; | |
336 | ||
337 | sf_handle = vboxsf_create_sf_handle(d_inode(dentry), handle, SHFL_CF_ACCESS_READWRITE); | |
338 | if (IS_ERR(sf_handle)) { | |
339 | vboxsf_close(sbi->root, handle); | |
340 | err = PTR_ERR(sf_handle); | |
341 | goto out; | |
342 | } | |
343 | ||
344 | err = finish_open(file, dentry, generic_file_open); | |
345 | if (err) { | |
346 | /* This also closes the handle passed to vboxsf_create_sf_handle() */ | |
347 | vboxsf_release_sf_handle(d_inode(dentry), sf_handle); | |
348 | goto out; | |
349 | } | |
350 | ||
351 | file->private_data = sf_handle; | |
352 | file->f_mode |= FMODE_CREATED; | |
353 | out: | |
354 | dput(res); | |
355 | return err; | |
356 | } | |
357 | ||
0fd16957 HG |
358 | static int vboxsf_dir_unlink(struct inode *parent, struct dentry *dentry) |
359 | { | |
360 | struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb); | |
361 | struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent); | |
362 | struct inode *inode = d_inode(dentry); | |
363 | struct shfl_string *path; | |
364 | u32 flags; | |
365 | int err; | |
366 | ||
367 | if (S_ISDIR(inode->i_mode)) | |
368 | flags = SHFL_REMOVE_DIR; | |
369 | else | |
370 | flags = SHFL_REMOVE_FILE; | |
371 | ||
372 | if (S_ISLNK(inode->i_mode)) | |
373 | flags |= SHFL_REMOVE_SYMLINK; | |
374 | ||
375 | path = vboxsf_path_from_dentry(sbi, dentry); | |
376 | if (IS_ERR(path)) | |
377 | return PTR_ERR(path); | |
378 | ||
379 | err = vboxsf_remove(sbi->root, path, flags); | |
380 | __putname(path); | |
381 | if (err) | |
382 | return err; | |
383 | ||
384 | /* parent directory access/change time changed */ | |
385 | sf_parent_i->force_restat = 1; | |
386 | ||
387 | return 0; | |
388 | } | |
389 | ||
e18275ae | 390 | static int vboxsf_dir_rename(struct mnt_idmap *idmap, |
549c7297 | 391 | struct inode *old_parent, |
0fd16957 HG |
392 | struct dentry *old_dentry, |
393 | struct inode *new_parent, | |
394 | struct dentry *new_dentry, | |
395 | unsigned int flags) | |
396 | { | |
397 | struct vboxsf_sbi *sbi = VBOXSF_SBI(old_parent->i_sb); | |
398 | struct vboxsf_inode *sf_old_parent_i = VBOXSF_I(old_parent); | |
399 | struct vboxsf_inode *sf_new_parent_i = VBOXSF_I(new_parent); | |
400 | u32 shfl_flags = SHFL_RENAME_FILE | SHFL_RENAME_REPLACE_IF_EXISTS; | |
401 | struct shfl_string *old_path, *new_path; | |
402 | int err; | |
403 | ||
404 | if (flags) | |
405 | return -EINVAL; | |
406 | ||
407 | old_path = vboxsf_path_from_dentry(sbi, old_dentry); | |
408 | if (IS_ERR(old_path)) | |
409 | return PTR_ERR(old_path); | |
410 | ||
411 | new_path = vboxsf_path_from_dentry(sbi, new_dentry); | |
412 | if (IS_ERR(new_path)) { | |
413 | err = PTR_ERR(new_path); | |
414 | goto err_put_old_path; | |
415 | } | |
416 | ||
417 | if (d_inode(old_dentry)->i_mode & S_IFDIR) | |
418 | shfl_flags = 0; | |
419 | ||
420 | err = vboxsf_rename(sbi->root, old_path, new_path, shfl_flags); | |
421 | if (err == 0) { | |
422 | /* parent directories access/change time changed */ | |
423 | sf_new_parent_i->force_restat = 1; | |
424 | sf_old_parent_i->force_restat = 1; | |
425 | } | |
426 | ||
427 | __putname(new_path); | |
428 | err_put_old_path: | |
429 | __putname(old_path); | |
430 | return err; | |
431 | } | |
432 | ||
7a77db95 | 433 | static int vboxsf_dir_symlink(struct mnt_idmap *idmap, |
549c7297 | 434 | struct inode *parent, struct dentry *dentry, |
0fd16957 HG |
435 | const char *symname) |
436 | { | |
437 | struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent); | |
438 | struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb); | |
439 | int symname_size = strlen(symname) + 1; | |
440 | struct shfl_string *path, *ssymname; | |
441 | struct shfl_fsobjinfo info; | |
442 | int err; | |
443 | ||
444 | path = vboxsf_path_from_dentry(sbi, dentry); | |
445 | if (IS_ERR(path)) | |
446 | return PTR_ERR(path); | |
447 | ||
448 | ssymname = kmalloc(SHFLSTRING_HEADER_SIZE + symname_size, GFP_KERNEL); | |
449 | if (!ssymname) { | |
450 | __putname(path); | |
451 | return -ENOMEM; | |
452 | } | |
453 | ssymname->length = symname_size - 1; | |
454 | ssymname->size = symname_size; | |
455 | memcpy(ssymname->string.utf8, symname, symname_size); | |
456 | ||
457 | err = vboxsf_symlink(sbi->root, path, ssymname, &info); | |
458 | kfree(ssymname); | |
459 | __putname(path); | |
460 | if (err) { | |
461 | /* -EROFS means symlinks are note support -> -EPERM */ | |
462 | return (err == -EROFS) ? -EPERM : err; | |
463 | } | |
464 | ||
465 | err = vboxsf_dir_instantiate(parent, dentry, &info); | |
466 | if (err) | |
467 | return err; | |
468 | ||
469 | /* parent directory access/change time changed */ | |
470 | sf_parent_i->force_restat = 1; | |
471 | return 0; | |
472 | } | |
473 | ||
474 | const struct inode_operations vboxsf_dir_iops = { | |
475 | .lookup = vboxsf_dir_lookup, | |
476 | .create = vboxsf_dir_mkfile, | |
477 | .mkdir = vboxsf_dir_mkdir, | |
52dfd86a | 478 | .atomic_open = vboxsf_dir_atomic_open, |
0fd16957 HG |
479 | .rmdir = vboxsf_dir_unlink, |
480 | .unlink = vboxsf_dir_unlink, | |
481 | .rename = vboxsf_dir_rename, | |
482 | .symlink = vboxsf_dir_symlink, | |
483 | .getattr = vboxsf_getattr, | |
484 | .setattr = vboxsf_setattr, | |
485 | }; |