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Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * fs/libfs.c | |
3 | * Library for filesystems writers. | |
4 | */ | |
5 | ||
6 | #include <linux/module.h> | |
7 | #include <linux/pagemap.h> | |
8 | #include <linux/mount.h> | |
9 | #include <linux/vfs.h> | |
7cf34c76 | 10 | #include <linux/mutex.h> |
2596110a | 11 | #include <linux/exportfs.h> |
7cf34c76 | 12 | |
1da177e4 LT |
13 | #include <asm/uaccess.h> |
14 | ||
15 | int simple_getattr(struct vfsmount *mnt, struct dentry *dentry, | |
16 | struct kstat *stat) | |
17 | { | |
18 | struct inode *inode = dentry->d_inode; | |
19 | generic_fillattr(inode, stat); | |
20 | stat->blocks = inode->i_mapping->nrpages << (PAGE_CACHE_SHIFT - 9); | |
21 | return 0; | |
22 | } | |
23 | ||
726c3342 | 24 | int simple_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 | 25 | { |
726c3342 | 26 | buf->f_type = dentry->d_sb->s_magic; |
1da177e4 LT |
27 | buf->f_bsize = PAGE_CACHE_SIZE; |
28 | buf->f_namelen = NAME_MAX; | |
29 | return 0; | |
30 | } | |
31 | ||
32 | /* | |
33 | * Retaining negative dentries for an in-memory filesystem just wastes | |
34 | * memory and lookup time: arrange for them to be deleted immediately. | |
35 | */ | |
36 | static int simple_delete_dentry(struct dentry *dentry) | |
37 | { | |
38 | return 1; | |
39 | } | |
40 | ||
41 | /* | |
42 | * Lookup the data. This is trivial - if the dentry didn't already | |
43 | * exist, we know it is negative. Set d_op to delete negative dentries. | |
44 | */ | |
45 | struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
46 | { | |
47 | static struct dentry_operations simple_dentry_operations = { | |
48 | .d_delete = simple_delete_dentry, | |
49 | }; | |
50 | ||
51 | if (dentry->d_name.len > NAME_MAX) | |
52 | return ERR_PTR(-ENAMETOOLONG); | |
53 | dentry->d_op = &simple_dentry_operations; | |
54 | d_add(dentry, NULL); | |
55 | return NULL; | |
56 | } | |
57 | ||
58 | int simple_sync_file(struct file * file, struct dentry *dentry, int datasync) | |
59 | { | |
60 | return 0; | |
61 | } | |
62 | ||
63 | int dcache_dir_open(struct inode *inode, struct file *file) | |
64 | { | |
65 | static struct qstr cursor_name = {.len = 1, .name = "."}; | |
66 | ||
0f7fc9e4 | 67 | file->private_data = d_alloc(file->f_path.dentry, &cursor_name); |
1da177e4 LT |
68 | |
69 | return file->private_data ? 0 : -ENOMEM; | |
70 | } | |
71 | ||
72 | int dcache_dir_close(struct inode *inode, struct file *file) | |
73 | { | |
74 | dput(file->private_data); | |
75 | return 0; | |
76 | } | |
77 | ||
78 | loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) | |
79 | { | |
0f7fc9e4 | 80 | mutex_lock(&file->f_path.dentry->d_inode->i_mutex); |
1da177e4 LT |
81 | switch (origin) { |
82 | case 1: | |
83 | offset += file->f_pos; | |
84 | case 0: | |
85 | if (offset >= 0) | |
86 | break; | |
87 | default: | |
0f7fc9e4 | 88 | mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); |
1da177e4 LT |
89 | return -EINVAL; |
90 | } | |
91 | if (offset != file->f_pos) { | |
92 | file->f_pos = offset; | |
93 | if (file->f_pos >= 2) { | |
94 | struct list_head *p; | |
95 | struct dentry *cursor = file->private_data; | |
96 | loff_t n = file->f_pos - 2; | |
97 | ||
98 | spin_lock(&dcache_lock); | |
5160ee6f | 99 | list_del(&cursor->d_u.d_child); |
0f7fc9e4 JJS |
100 | p = file->f_path.dentry->d_subdirs.next; |
101 | while (n && p != &file->f_path.dentry->d_subdirs) { | |
1da177e4 | 102 | struct dentry *next; |
5160ee6f | 103 | next = list_entry(p, struct dentry, d_u.d_child); |
1da177e4 LT |
104 | if (!d_unhashed(next) && next->d_inode) |
105 | n--; | |
106 | p = p->next; | |
107 | } | |
5160ee6f | 108 | list_add_tail(&cursor->d_u.d_child, p); |
1da177e4 LT |
109 | spin_unlock(&dcache_lock); |
110 | } | |
111 | } | |
0f7fc9e4 | 112 | mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); |
1da177e4 LT |
113 | return offset; |
114 | } | |
115 | ||
116 | /* Relationship between i_mode and the DT_xxx types */ | |
117 | static inline unsigned char dt_type(struct inode *inode) | |
118 | { | |
119 | return (inode->i_mode >> 12) & 15; | |
120 | } | |
121 | ||
122 | /* | |
123 | * Directory is locked and all positive dentries in it are safe, since | |
124 | * for ramfs-type trees they can't go away without unlink() or rmdir(), | |
125 | * both impossible due to the lock on directory. | |
126 | */ | |
127 | ||
128 | int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) | |
129 | { | |
0f7fc9e4 | 130 | struct dentry *dentry = filp->f_path.dentry; |
1da177e4 | 131 | struct dentry *cursor = filp->private_data; |
5160ee6f | 132 | struct list_head *p, *q = &cursor->d_u.d_child; |
1da177e4 LT |
133 | ino_t ino; |
134 | int i = filp->f_pos; | |
135 | ||
136 | switch (i) { | |
137 | case 0: | |
138 | ino = dentry->d_inode->i_ino; | |
139 | if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) | |
140 | break; | |
141 | filp->f_pos++; | |
142 | i++; | |
143 | /* fallthrough */ | |
144 | case 1: | |
145 | ino = parent_ino(dentry); | |
146 | if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) | |
147 | break; | |
148 | filp->f_pos++; | |
149 | i++; | |
150 | /* fallthrough */ | |
151 | default: | |
152 | spin_lock(&dcache_lock); | |
1bfba4e8 AM |
153 | if (filp->f_pos == 2) |
154 | list_move(q, &dentry->d_subdirs); | |
155 | ||
1da177e4 LT |
156 | for (p=q->next; p != &dentry->d_subdirs; p=p->next) { |
157 | struct dentry *next; | |
5160ee6f | 158 | next = list_entry(p, struct dentry, d_u.d_child); |
1da177e4 LT |
159 | if (d_unhashed(next) || !next->d_inode) |
160 | continue; | |
161 | ||
162 | spin_unlock(&dcache_lock); | |
0f8952c2 RN |
163 | if (filldir(dirent, next->d_name.name, |
164 | next->d_name.len, filp->f_pos, | |
165 | next->d_inode->i_ino, | |
166 | dt_type(next->d_inode)) < 0) | |
1da177e4 LT |
167 | return 0; |
168 | spin_lock(&dcache_lock); | |
169 | /* next is still alive */ | |
1bfba4e8 | 170 | list_move(q, p); |
1da177e4 LT |
171 | p = q; |
172 | filp->f_pos++; | |
173 | } | |
174 | spin_unlock(&dcache_lock); | |
175 | } | |
176 | return 0; | |
177 | } | |
178 | ||
179 | ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos) | |
180 | { | |
181 | return -EISDIR; | |
182 | } | |
183 | ||
4b6f5d20 | 184 | const struct file_operations simple_dir_operations = { |
1da177e4 LT |
185 | .open = dcache_dir_open, |
186 | .release = dcache_dir_close, | |
187 | .llseek = dcache_dir_lseek, | |
188 | .read = generic_read_dir, | |
189 | .readdir = dcache_readdir, | |
8ae0b778 | 190 | .fsync = simple_sync_file, |
1da177e4 LT |
191 | }; |
192 | ||
92e1d5be | 193 | const struct inode_operations simple_dir_inode_operations = { |
1da177e4 LT |
194 | .lookup = simple_lookup, |
195 | }; | |
196 | ||
759b9775 HD |
197 | static const struct super_operations simple_super_operations = { |
198 | .statfs = simple_statfs, | |
199 | }; | |
200 | ||
1da177e4 LT |
201 | /* |
202 | * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that | |
203 | * will never be mountable) | |
204 | */ | |
454e2398 | 205 | int get_sb_pseudo(struct file_system_type *fs_type, char *name, |
ee9b6d61 | 206 | const struct super_operations *ops, unsigned long magic, |
454e2398 | 207 | struct vfsmount *mnt) |
1da177e4 LT |
208 | { |
209 | struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL); | |
1da177e4 LT |
210 | struct dentry *dentry; |
211 | struct inode *root; | |
212 | struct qstr d_name = {.name = name, .len = strlen(name)}; | |
213 | ||
214 | if (IS_ERR(s)) | |
454e2398 | 215 | return PTR_ERR(s); |
1da177e4 LT |
216 | |
217 | s->s_flags = MS_NOUSER; | |
218 | s->s_maxbytes = ~0ULL; | |
219 | s->s_blocksize = 1024; | |
220 | s->s_blocksize_bits = 10; | |
221 | s->s_magic = magic; | |
759b9775 | 222 | s->s_op = ops ? ops : &simple_super_operations; |
1da177e4 LT |
223 | s->s_time_gran = 1; |
224 | root = new_inode(s); | |
225 | if (!root) | |
226 | goto Enomem; | |
1a1c9bb4 JL |
227 | /* |
228 | * since this is the first inode, make it number 1. New inodes created | |
229 | * after this must take care not to collide with it (by passing | |
230 | * max_reserved of 1 to iunique). | |
231 | */ | |
232 | root->i_ino = 1; | |
1da177e4 LT |
233 | root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR; |
234 | root->i_uid = root->i_gid = 0; | |
235 | root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME; | |
236 | dentry = d_alloc(NULL, &d_name); | |
237 | if (!dentry) { | |
238 | iput(root); | |
239 | goto Enomem; | |
240 | } | |
241 | dentry->d_sb = s; | |
242 | dentry->d_parent = dentry; | |
243 | d_instantiate(dentry, root); | |
244 | s->s_root = dentry; | |
245 | s->s_flags |= MS_ACTIVE; | |
454e2398 | 246 | return simple_set_mnt(mnt, s); |
1da177e4 LT |
247 | |
248 | Enomem: | |
249 | up_write(&s->s_umount); | |
250 | deactivate_super(s); | |
454e2398 | 251 | return -ENOMEM; |
1da177e4 LT |
252 | } |
253 | ||
254 | int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) | |
255 | { | |
256 | struct inode *inode = old_dentry->d_inode; | |
257 | ||
258 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
d8c76e6f | 259 | inc_nlink(inode); |
1da177e4 LT |
260 | atomic_inc(&inode->i_count); |
261 | dget(dentry); | |
262 | d_instantiate(dentry, inode); | |
263 | return 0; | |
264 | } | |
265 | ||
266 | static inline int simple_positive(struct dentry *dentry) | |
267 | { | |
268 | return dentry->d_inode && !d_unhashed(dentry); | |
269 | } | |
270 | ||
271 | int simple_empty(struct dentry *dentry) | |
272 | { | |
273 | struct dentry *child; | |
274 | int ret = 0; | |
275 | ||
276 | spin_lock(&dcache_lock); | |
5160ee6f | 277 | list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) |
1da177e4 LT |
278 | if (simple_positive(child)) |
279 | goto out; | |
280 | ret = 1; | |
281 | out: | |
282 | spin_unlock(&dcache_lock); | |
283 | return ret; | |
284 | } | |
285 | ||
286 | int simple_unlink(struct inode *dir, struct dentry *dentry) | |
287 | { | |
288 | struct inode *inode = dentry->d_inode; | |
289 | ||
290 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
9a53c3a7 | 291 | drop_nlink(inode); |
1da177e4 LT |
292 | dput(dentry); |
293 | return 0; | |
294 | } | |
295 | ||
296 | int simple_rmdir(struct inode *dir, struct dentry *dentry) | |
297 | { | |
298 | if (!simple_empty(dentry)) | |
299 | return -ENOTEMPTY; | |
300 | ||
9a53c3a7 | 301 | drop_nlink(dentry->d_inode); |
1da177e4 | 302 | simple_unlink(dir, dentry); |
9a53c3a7 | 303 | drop_nlink(dir); |
1da177e4 LT |
304 | return 0; |
305 | } | |
306 | ||
307 | int simple_rename(struct inode *old_dir, struct dentry *old_dentry, | |
308 | struct inode *new_dir, struct dentry *new_dentry) | |
309 | { | |
310 | struct inode *inode = old_dentry->d_inode; | |
311 | int they_are_dirs = S_ISDIR(old_dentry->d_inode->i_mode); | |
312 | ||
313 | if (!simple_empty(new_dentry)) | |
314 | return -ENOTEMPTY; | |
315 | ||
316 | if (new_dentry->d_inode) { | |
317 | simple_unlink(new_dir, new_dentry); | |
318 | if (they_are_dirs) | |
9a53c3a7 | 319 | drop_nlink(old_dir); |
1da177e4 | 320 | } else if (they_are_dirs) { |
9a53c3a7 | 321 | drop_nlink(old_dir); |
d8c76e6f | 322 | inc_nlink(new_dir); |
1da177e4 LT |
323 | } |
324 | ||
325 | old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime = | |
326 | new_dir->i_mtime = inode->i_ctime = CURRENT_TIME; | |
327 | ||
328 | return 0; | |
329 | } | |
330 | ||
331 | int simple_readpage(struct file *file, struct page *page) | |
332 | { | |
c0d92cbc | 333 | clear_highpage(page); |
1da177e4 LT |
334 | flush_dcache_page(page); |
335 | SetPageUptodate(page); | |
1da177e4 LT |
336 | unlock_page(page); |
337 | return 0; | |
338 | } | |
339 | ||
340 | int simple_prepare_write(struct file *file, struct page *page, | |
341 | unsigned from, unsigned to) | |
342 | { | |
343 | if (!PageUptodate(page)) { | |
344 | if (to - from != PAGE_CACHE_SIZE) { | |
345 | void *kaddr = kmap_atomic(page, KM_USER0); | |
346 | memset(kaddr, 0, from); | |
347 | memset(kaddr + to, 0, PAGE_CACHE_SIZE - to); | |
348 | flush_dcache_page(page); | |
349 | kunmap_atomic(kaddr, KM_USER0); | |
350 | } | |
1da177e4 LT |
351 | } |
352 | return 0; | |
353 | } | |
354 | ||
afddba49 NP |
355 | int simple_write_begin(struct file *file, struct address_space *mapping, |
356 | loff_t pos, unsigned len, unsigned flags, | |
357 | struct page **pagep, void **fsdata) | |
358 | { | |
359 | struct page *page; | |
360 | pgoff_t index; | |
361 | unsigned from; | |
362 | ||
363 | index = pos >> PAGE_CACHE_SHIFT; | |
364 | from = pos & (PAGE_CACHE_SIZE - 1); | |
365 | ||
366 | page = __grab_cache_page(mapping, index); | |
367 | if (!page) | |
368 | return -ENOMEM; | |
369 | ||
370 | *pagep = page; | |
371 | ||
372 | return simple_prepare_write(file, page, from, from+len); | |
373 | } | |
374 | ||
4a239427 AB |
375 | static int simple_commit_write(struct file *file, struct page *page, |
376 | unsigned from, unsigned to) | |
1da177e4 LT |
377 | { |
378 | struct inode *inode = page->mapping->host; | |
379 | loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; | |
380 | ||
955eff5a NP |
381 | if (!PageUptodate(page)) |
382 | SetPageUptodate(page); | |
1da177e4 LT |
383 | /* |
384 | * No need to use i_size_read() here, the i_size | |
1b1dcc1b | 385 | * cannot change under us because we hold the i_mutex. |
1da177e4 LT |
386 | */ |
387 | if (pos > inode->i_size) | |
388 | i_size_write(inode, pos); | |
389 | set_page_dirty(page); | |
390 | return 0; | |
391 | } | |
392 | ||
afddba49 NP |
393 | int simple_write_end(struct file *file, struct address_space *mapping, |
394 | loff_t pos, unsigned len, unsigned copied, | |
395 | struct page *page, void *fsdata) | |
396 | { | |
397 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
398 | ||
399 | /* zero the stale part of the page if we did a short copy */ | |
400 | if (copied < len) { | |
401 | void *kaddr = kmap_atomic(page, KM_USER0); | |
402 | memset(kaddr + from + copied, 0, len - copied); | |
403 | flush_dcache_page(page); | |
404 | kunmap_atomic(kaddr, KM_USER0); | |
405 | } | |
406 | ||
407 | simple_commit_write(file, page, from, from+copied); | |
408 | ||
409 | unlock_page(page); | |
410 | page_cache_release(page); | |
411 | ||
412 | return copied; | |
413 | } | |
414 | ||
1a1c9bb4 JL |
415 | /* |
416 | * the inodes created here are not hashed. If you use iunique to generate | |
417 | * unique inode values later for this filesystem, then you must take care | |
418 | * to pass it an appropriate max_reserved value to avoid collisions. | |
419 | */ | |
1da177e4 LT |
420 | int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files) |
421 | { | |
1da177e4 LT |
422 | struct inode *inode; |
423 | struct dentry *root; | |
424 | struct dentry *dentry; | |
425 | int i; | |
426 | ||
427 | s->s_blocksize = PAGE_CACHE_SIZE; | |
428 | s->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
429 | s->s_magic = magic; | |
759b9775 | 430 | s->s_op = &simple_super_operations; |
1da177e4 LT |
431 | s->s_time_gran = 1; |
432 | ||
433 | inode = new_inode(s); | |
434 | if (!inode) | |
435 | return -ENOMEM; | |
1a1c9bb4 JL |
436 | /* |
437 | * because the root inode is 1, the files array must not contain an | |
438 | * entry at index 1 | |
439 | */ | |
440 | inode->i_ino = 1; | |
1da177e4 LT |
441 | inode->i_mode = S_IFDIR | 0755; |
442 | inode->i_uid = inode->i_gid = 0; | |
1da177e4 LT |
443 | inode->i_blocks = 0; |
444 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
445 | inode->i_op = &simple_dir_inode_operations; | |
446 | inode->i_fop = &simple_dir_operations; | |
7656f328 | 447 | inode->i_nlink = 2; |
1da177e4 LT |
448 | root = d_alloc_root(inode); |
449 | if (!root) { | |
450 | iput(inode); | |
451 | return -ENOMEM; | |
452 | } | |
453 | for (i = 0; !files->name || files->name[0]; i++, files++) { | |
454 | if (!files->name) | |
455 | continue; | |
1a1c9bb4 JL |
456 | |
457 | /* warn if it tries to conflict with the root inode */ | |
458 | if (unlikely(i == 1)) | |
459 | printk(KERN_WARNING "%s: %s passed in a files array" | |
460 | "with an index of 1!\n", __func__, | |
461 | s->s_type->name); | |
462 | ||
1da177e4 LT |
463 | dentry = d_alloc_name(root, files->name); |
464 | if (!dentry) | |
465 | goto out; | |
466 | inode = new_inode(s); | |
467 | if (!inode) | |
468 | goto out; | |
469 | inode->i_mode = S_IFREG | files->mode; | |
470 | inode->i_uid = inode->i_gid = 0; | |
1da177e4 LT |
471 | inode->i_blocks = 0; |
472 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
473 | inode->i_fop = files->ops; | |
474 | inode->i_ino = i; | |
475 | d_add(dentry, inode); | |
476 | } | |
477 | s->s_root = root; | |
478 | return 0; | |
479 | out: | |
480 | d_genocide(root); | |
481 | dput(root); | |
482 | return -ENOMEM; | |
483 | } | |
484 | ||
485 | static DEFINE_SPINLOCK(pin_fs_lock); | |
486 | ||
1f5ce9e9 | 487 | int simple_pin_fs(struct file_system_type *type, struct vfsmount **mount, int *count) |
1da177e4 LT |
488 | { |
489 | struct vfsmount *mnt = NULL; | |
490 | spin_lock(&pin_fs_lock); | |
491 | if (unlikely(!*mount)) { | |
492 | spin_unlock(&pin_fs_lock); | |
1f5ce9e9 | 493 | mnt = vfs_kern_mount(type, 0, type->name, NULL); |
1da177e4 LT |
494 | if (IS_ERR(mnt)) |
495 | return PTR_ERR(mnt); | |
496 | spin_lock(&pin_fs_lock); | |
497 | if (!*mount) | |
498 | *mount = mnt; | |
499 | } | |
500 | mntget(*mount); | |
501 | ++*count; | |
502 | spin_unlock(&pin_fs_lock); | |
503 | mntput(mnt); | |
504 | return 0; | |
505 | } | |
506 | ||
507 | void simple_release_fs(struct vfsmount **mount, int *count) | |
508 | { | |
509 | struct vfsmount *mnt; | |
510 | spin_lock(&pin_fs_lock); | |
511 | mnt = *mount; | |
512 | if (!--*count) | |
513 | *mount = NULL; | |
514 | spin_unlock(&pin_fs_lock); | |
515 | mntput(mnt); | |
516 | } | |
517 | ||
518 | ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, | |
519 | const void *from, size_t available) | |
520 | { | |
521 | loff_t pos = *ppos; | |
522 | if (pos < 0) | |
523 | return -EINVAL; | |
524 | if (pos >= available) | |
525 | return 0; | |
526 | if (count > available - pos) | |
527 | count = available - pos; | |
528 | if (copy_to_user(to, from + pos, count)) | |
529 | return -EFAULT; | |
530 | *ppos = pos + count; | |
531 | return count; | |
532 | } | |
533 | ||
534 | /* | |
535 | * Transaction based IO. | |
536 | * The file expects a single write which triggers the transaction, and then | |
537 | * possibly a read which collects the result - which is stored in a | |
538 | * file-local buffer. | |
539 | */ | |
540 | char *simple_transaction_get(struct file *file, const char __user *buf, size_t size) | |
541 | { | |
542 | struct simple_transaction_argresp *ar; | |
543 | static DEFINE_SPINLOCK(simple_transaction_lock); | |
544 | ||
545 | if (size > SIMPLE_TRANSACTION_LIMIT - 1) | |
546 | return ERR_PTR(-EFBIG); | |
547 | ||
548 | ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL); | |
549 | if (!ar) | |
550 | return ERR_PTR(-ENOMEM); | |
551 | ||
552 | spin_lock(&simple_transaction_lock); | |
553 | ||
554 | /* only one write allowed per open */ | |
555 | if (file->private_data) { | |
556 | spin_unlock(&simple_transaction_lock); | |
557 | free_page((unsigned long)ar); | |
558 | return ERR_PTR(-EBUSY); | |
559 | } | |
560 | ||
561 | file->private_data = ar; | |
562 | ||
563 | spin_unlock(&simple_transaction_lock); | |
564 | ||
565 | if (copy_from_user(ar->data, buf, size)) | |
566 | return ERR_PTR(-EFAULT); | |
567 | ||
568 | return ar->data; | |
569 | } | |
570 | ||
571 | ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos) | |
572 | { | |
573 | struct simple_transaction_argresp *ar = file->private_data; | |
574 | ||
575 | if (!ar) | |
576 | return 0; | |
577 | return simple_read_from_buffer(buf, size, pos, ar->data, ar->size); | |
578 | } | |
579 | ||
580 | int simple_transaction_release(struct inode *inode, struct file *file) | |
581 | { | |
582 | free_page((unsigned long)file->private_data); | |
583 | return 0; | |
584 | } | |
585 | ||
acaefc25 AB |
586 | /* Simple attribute files */ |
587 | ||
588 | struct simple_attr { | |
589 | u64 (*get)(void *); | |
590 | void (*set)(void *, u64); | |
591 | char get_buf[24]; /* enough to store a u64 and "\n\0" */ | |
592 | char set_buf[24]; | |
593 | void *data; | |
594 | const char *fmt; /* format for read operation */ | |
7cf34c76 | 595 | struct mutex mutex; /* protects access to these buffers */ |
acaefc25 AB |
596 | }; |
597 | ||
598 | /* simple_attr_open is called by an actual attribute open file operation | |
599 | * to set the attribute specific access operations. */ | |
600 | int simple_attr_open(struct inode *inode, struct file *file, | |
601 | u64 (*get)(void *), void (*set)(void *, u64), | |
602 | const char *fmt) | |
603 | { | |
604 | struct simple_attr *attr; | |
605 | ||
606 | attr = kmalloc(sizeof(*attr), GFP_KERNEL); | |
607 | if (!attr) | |
608 | return -ENOMEM; | |
609 | ||
610 | attr->get = get; | |
611 | attr->set = set; | |
8e18e294 | 612 | attr->data = inode->i_private; |
acaefc25 | 613 | attr->fmt = fmt; |
7cf34c76 | 614 | mutex_init(&attr->mutex); |
acaefc25 AB |
615 | |
616 | file->private_data = attr; | |
617 | ||
618 | return nonseekable_open(inode, file); | |
619 | } | |
620 | ||
621 | int simple_attr_close(struct inode *inode, struct file *file) | |
622 | { | |
623 | kfree(file->private_data); | |
624 | return 0; | |
625 | } | |
626 | ||
627 | /* read from the buffer that is filled with the get function */ | |
628 | ssize_t simple_attr_read(struct file *file, char __user *buf, | |
629 | size_t len, loff_t *ppos) | |
630 | { | |
631 | struct simple_attr *attr; | |
632 | size_t size; | |
633 | ssize_t ret; | |
634 | ||
635 | attr = file->private_data; | |
636 | ||
637 | if (!attr->get) | |
638 | return -EACCES; | |
639 | ||
7cf34c76 | 640 | mutex_lock(&attr->mutex); |
acaefc25 AB |
641 | if (*ppos) /* continued read */ |
642 | size = strlen(attr->get_buf); | |
643 | else /* first read */ | |
644 | size = scnprintf(attr->get_buf, sizeof(attr->get_buf), | |
645 | attr->fmt, | |
646 | (unsigned long long)attr->get(attr->data)); | |
647 | ||
648 | ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size); | |
7cf34c76 | 649 | mutex_unlock(&attr->mutex); |
acaefc25 AB |
650 | return ret; |
651 | } | |
652 | ||
653 | /* interpret the buffer as a number to call the set function with */ | |
654 | ssize_t simple_attr_write(struct file *file, const char __user *buf, | |
655 | size_t len, loff_t *ppos) | |
656 | { | |
657 | struct simple_attr *attr; | |
658 | u64 val; | |
659 | size_t size; | |
660 | ssize_t ret; | |
661 | ||
662 | attr = file->private_data; | |
663 | ||
664 | if (!attr->set) | |
665 | return -EACCES; | |
666 | ||
7cf34c76 | 667 | mutex_lock(&attr->mutex); |
acaefc25 AB |
668 | ret = -EFAULT; |
669 | size = min(sizeof(attr->set_buf) - 1, len); | |
670 | if (copy_from_user(attr->set_buf, buf, size)) | |
671 | goto out; | |
672 | ||
673 | ret = len; /* claim we got the whole input */ | |
674 | attr->set_buf[size] = '\0'; | |
675 | val = simple_strtol(attr->set_buf, NULL, 0); | |
676 | attr->set(attr->data, val); | |
677 | out: | |
7cf34c76 | 678 | mutex_unlock(&attr->mutex); |
acaefc25 AB |
679 | return ret; |
680 | } | |
681 | ||
2596110a CH |
682 | /* |
683 | * This is what d_alloc_anon should have been. Once the exportfs | |
684 | * argument transition has been finished I will update d_alloc_anon | |
685 | * to this prototype and this wrapper will go away. --hch | |
686 | */ | |
687 | static struct dentry *exportfs_d_alloc(struct inode *inode) | |
688 | { | |
689 | struct dentry *dentry; | |
690 | ||
691 | if (!inode) | |
692 | return NULL; | |
693 | if (IS_ERR(inode)) | |
694 | return ERR_PTR(PTR_ERR(inode)); | |
695 | ||
696 | dentry = d_alloc_anon(inode); | |
697 | if (!dentry) { | |
698 | iput(inode); | |
699 | dentry = ERR_PTR(-ENOMEM); | |
700 | } | |
701 | return dentry; | |
702 | } | |
703 | ||
704 | /** | |
705 | * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation | |
706 | * @sb: filesystem to do the file handle conversion on | |
707 | * @fid: file handle to convert | |
708 | * @fh_len: length of the file handle in bytes | |
709 | * @fh_type: type of file handle | |
710 | * @get_inode: filesystem callback to retrieve inode | |
711 | * | |
712 | * This function decodes @fid as long as it has one of the well-known | |
713 | * Linux filehandle types and calls @get_inode on it to retrieve the | |
714 | * inode for the object specified in the file handle. | |
715 | */ | |
716 | struct dentry *generic_fh_to_dentry(struct super_block *sb, struct fid *fid, | |
717 | int fh_len, int fh_type, struct inode *(*get_inode) | |
718 | (struct super_block *sb, u64 ino, u32 gen)) | |
719 | { | |
720 | struct inode *inode = NULL; | |
721 | ||
722 | if (fh_len < 2) | |
723 | return NULL; | |
724 | ||
725 | switch (fh_type) { | |
726 | case FILEID_INO32_GEN: | |
727 | case FILEID_INO32_GEN_PARENT: | |
728 | inode = get_inode(sb, fid->i32.ino, fid->i32.gen); | |
729 | break; | |
730 | } | |
731 | ||
732 | return exportfs_d_alloc(inode); | |
733 | } | |
734 | EXPORT_SYMBOL_GPL(generic_fh_to_dentry); | |
735 | ||
736 | /** | |
737 | * generic_fh_to_dentry - generic helper for the fh_to_parent export operation | |
738 | * @sb: filesystem to do the file handle conversion on | |
739 | * @fid: file handle to convert | |
740 | * @fh_len: length of the file handle in bytes | |
741 | * @fh_type: type of file handle | |
742 | * @get_inode: filesystem callback to retrieve inode | |
743 | * | |
744 | * This function decodes @fid as long as it has one of the well-known | |
745 | * Linux filehandle types and calls @get_inode on it to retrieve the | |
746 | * inode for the _parent_ object specified in the file handle if it | |
747 | * is specified in the file handle, or NULL otherwise. | |
748 | */ | |
749 | struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid, | |
750 | int fh_len, int fh_type, struct inode *(*get_inode) | |
751 | (struct super_block *sb, u64 ino, u32 gen)) | |
752 | { | |
753 | struct inode *inode = NULL; | |
754 | ||
755 | if (fh_len <= 2) | |
756 | return NULL; | |
757 | ||
758 | switch (fh_type) { | |
759 | case FILEID_INO32_GEN_PARENT: | |
760 | inode = get_inode(sb, fid->i32.parent_ino, | |
761 | (fh_len > 3 ? fid->i32.parent_gen : 0)); | |
762 | break; | |
763 | } | |
764 | ||
765 | return exportfs_d_alloc(inode); | |
766 | } | |
767 | EXPORT_SYMBOL_GPL(generic_fh_to_parent); | |
768 | ||
1da177e4 LT |
769 | EXPORT_SYMBOL(dcache_dir_close); |
770 | EXPORT_SYMBOL(dcache_dir_lseek); | |
771 | EXPORT_SYMBOL(dcache_dir_open); | |
772 | EXPORT_SYMBOL(dcache_readdir); | |
773 | EXPORT_SYMBOL(generic_read_dir); | |
774 | EXPORT_SYMBOL(get_sb_pseudo); | |
afddba49 NP |
775 | EXPORT_SYMBOL(simple_write_begin); |
776 | EXPORT_SYMBOL(simple_write_end); | |
1da177e4 LT |
777 | EXPORT_SYMBOL(simple_dir_inode_operations); |
778 | EXPORT_SYMBOL(simple_dir_operations); | |
779 | EXPORT_SYMBOL(simple_empty); | |
780 | EXPORT_SYMBOL(d_alloc_name); | |
781 | EXPORT_SYMBOL(simple_fill_super); | |
782 | EXPORT_SYMBOL(simple_getattr); | |
783 | EXPORT_SYMBOL(simple_link); | |
784 | EXPORT_SYMBOL(simple_lookup); | |
785 | EXPORT_SYMBOL(simple_pin_fs); | |
786 | EXPORT_SYMBOL(simple_prepare_write); | |
787 | EXPORT_SYMBOL(simple_readpage); | |
788 | EXPORT_SYMBOL(simple_release_fs); | |
789 | EXPORT_SYMBOL(simple_rename); | |
790 | EXPORT_SYMBOL(simple_rmdir); | |
791 | EXPORT_SYMBOL(simple_statfs); | |
792 | EXPORT_SYMBOL(simple_sync_file); | |
793 | EXPORT_SYMBOL(simple_unlink); | |
794 | EXPORT_SYMBOL(simple_read_from_buffer); | |
795 | EXPORT_SYMBOL(simple_transaction_get); | |
796 | EXPORT_SYMBOL(simple_transaction_read); | |
797 | EXPORT_SYMBOL(simple_transaction_release); | |
acaefc25 AB |
798 | EXPORT_SYMBOL_GPL(simple_attr_open); |
799 | EXPORT_SYMBOL_GPL(simple_attr_close); | |
800 | EXPORT_SYMBOL_GPL(simple_attr_read); | |
801 | EXPORT_SYMBOL_GPL(simple_attr_write); |