Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * fs/libfs.c | |
3 | * Library for filesystems writers. | |
4 | */ | |
5 | ||
630d9c47 | 6 | #include <linux/export.h> |
1da177e4 | 7 | #include <linux/pagemap.h> |
5a0e3ad6 | 8 | #include <linux/slab.h> |
1da177e4 LT |
9 | #include <linux/mount.h> |
10 | #include <linux/vfs.h> | |
7bb46a67 | 11 | #include <linux/quotaops.h> |
7cf34c76 | 12 | #include <linux/mutex.h> |
87dc800b | 13 | #include <linux/namei.h> |
2596110a | 14 | #include <linux/exportfs.h> |
d5aacad5 | 15 | #include <linux/writeback.h> |
ff01bb48 | 16 | #include <linux/buffer_head.h> /* sync_mapping_buffers */ |
7cf34c76 | 17 | |
1da177e4 LT |
18 | #include <asm/uaccess.h> |
19 | ||
a4464dbc AV |
20 | #include "internal.h" |
21 | ||
da502956 NP |
22 | static inline int simple_positive(struct dentry *dentry) |
23 | { | |
24 | return dentry->d_inode && !d_unhashed(dentry); | |
25 | } | |
26 | ||
1da177e4 LT |
27 | int simple_getattr(struct vfsmount *mnt, struct dentry *dentry, |
28 | struct kstat *stat) | |
29 | { | |
30 | struct inode *inode = dentry->d_inode; | |
31 | generic_fillattr(inode, stat); | |
32 | stat->blocks = inode->i_mapping->nrpages << (PAGE_CACHE_SHIFT - 9); | |
33 | return 0; | |
34 | } | |
12f38872 | 35 | EXPORT_SYMBOL(simple_getattr); |
1da177e4 | 36 | |
726c3342 | 37 | int simple_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 | 38 | { |
726c3342 | 39 | buf->f_type = dentry->d_sb->s_magic; |
1da177e4 LT |
40 | buf->f_bsize = PAGE_CACHE_SIZE; |
41 | buf->f_namelen = NAME_MAX; | |
42 | return 0; | |
43 | } | |
12f38872 | 44 | EXPORT_SYMBOL(simple_statfs); |
1da177e4 LT |
45 | |
46 | /* | |
47 | * Retaining negative dentries for an in-memory filesystem just wastes | |
48 | * memory and lookup time: arrange for them to be deleted immediately. | |
49 | */ | |
b26d4cd3 | 50 | int always_delete_dentry(const struct dentry *dentry) |
1da177e4 LT |
51 | { |
52 | return 1; | |
53 | } | |
b26d4cd3 AV |
54 | EXPORT_SYMBOL(always_delete_dentry); |
55 | ||
56 | const struct dentry_operations simple_dentry_operations = { | |
57 | .d_delete = always_delete_dentry, | |
58 | }; | |
59 | EXPORT_SYMBOL(simple_dentry_operations); | |
1da177e4 LT |
60 | |
61 | /* | |
62 | * Lookup the data. This is trivial - if the dentry didn't already | |
63 | * exist, we know it is negative. Set d_op to delete negative dentries. | |
64 | */ | |
00cd8dd3 | 65 | struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
1da177e4 | 66 | { |
1da177e4 LT |
67 | if (dentry->d_name.len > NAME_MAX) |
68 | return ERR_PTR(-ENAMETOOLONG); | |
74931da7 AV |
69 | if (!dentry->d_sb->s_d_op) |
70 | d_set_d_op(dentry, &simple_dentry_operations); | |
1da177e4 LT |
71 | d_add(dentry, NULL); |
72 | return NULL; | |
73 | } | |
12f38872 | 74 | EXPORT_SYMBOL(simple_lookup); |
1da177e4 | 75 | |
1da177e4 LT |
76 | int dcache_dir_open(struct inode *inode, struct file *file) |
77 | { | |
26fe5750 | 78 | static struct qstr cursor_name = QSTR_INIT(".", 1); |
1da177e4 | 79 | |
0f7fc9e4 | 80 | file->private_data = d_alloc(file->f_path.dentry, &cursor_name); |
1da177e4 LT |
81 | |
82 | return file->private_data ? 0 : -ENOMEM; | |
83 | } | |
12f38872 | 84 | EXPORT_SYMBOL(dcache_dir_open); |
1da177e4 LT |
85 | |
86 | int dcache_dir_close(struct inode *inode, struct file *file) | |
87 | { | |
88 | dput(file->private_data); | |
89 | return 0; | |
90 | } | |
12f38872 | 91 | EXPORT_SYMBOL(dcache_dir_close); |
1da177e4 | 92 | |
965c8e59 | 93 | loff_t dcache_dir_lseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 94 | { |
2fd6b7f5 NP |
95 | struct dentry *dentry = file->f_path.dentry; |
96 | mutex_lock(&dentry->d_inode->i_mutex); | |
965c8e59 | 97 | switch (whence) { |
1da177e4 LT |
98 | case 1: |
99 | offset += file->f_pos; | |
100 | case 0: | |
101 | if (offset >= 0) | |
102 | break; | |
103 | default: | |
2fd6b7f5 | 104 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
105 | return -EINVAL; |
106 | } | |
107 | if (offset != file->f_pos) { | |
108 | file->f_pos = offset; | |
109 | if (file->f_pos >= 2) { | |
110 | struct list_head *p; | |
111 | struct dentry *cursor = file->private_data; | |
112 | loff_t n = file->f_pos - 2; | |
113 | ||
2fd6b7f5 NP |
114 | spin_lock(&dentry->d_lock); |
115 | /* d_lock not required for cursor */ | |
5160ee6f | 116 | list_del(&cursor->d_u.d_child); |
2fd6b7f5 NP |
117 | p = dentry->d_subdirs.next; |
118 | while (n && p != &dentry->d_subdirs) { | |
1da177e4 | 119 | struct dentry *next; |
5160ee6f | 120 | next = list_entry(p, struct dentry, d_u.d_child); |
2fd6b7f5 | 121 | spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); |
da502956 | 122 | if (simple_positive(next)) |
1da177e4 | 123 | n--; |
da502956 | 124 | spin_unlock(&next->d_lock); |
1da177e4 LT |
125 | p = p->next; |
126 | } | |
5160ee6f | 127 | list_add_tail(&cursor->d_u.d_child, p); |
2fd6b7f5 | 128 | spin_unlock(&dentry->d_lock); |
1da177e4 LT |
129 | } |
130 | } | |
2fd6b7f5 | 131 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
132 | return offset; |
133 | } | |
12f38872 | 134 | EXPORT_SYMBOL(dcache_dir_lseek); |
1da177e4 LT |
135 | |
136 | /* Relationship between i_mode and the DT_xxx types */ | |
137 | static inline unsigned char dt_type(struct inode *inode) | |
138 | { | |
139 | return (inode->i_mode >> 12) & 15; | |
140 | } | |
141 | ||
142 | /* | |
143 | * Directory is locked and all positive dentries in it are safe, since | |
144 | * for ramfs-type trees they can't go away without unlink() or rmdir(), | |
145 | * both impossible due to the lock on directory. | |
146 | */ | |
147 | ||
5f99f4e7 | 148 | int dcache_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 149 | { |
5f99f4e7 AV |
150 | struct dentry *dentry = file->f_path.dentry; |
151 | struct dentry *cursor = file->private_data; | |
5160ee6f | 152 | struct list_head *p, *q = &cursor->d_u.d_child; |
1da177e4 | 153 | |
5f99f4e7 AV |
154 | if (!dir_emit_dots(file, ctx)) |
155 | return 0; | |
156 | spin_lock(&dentry->d_lock); | |
157 | if (ctx->pos == 2) | |
158 | list_move(q, &dentry->d_subdirs); | |
159 | ||
160 | for (p = q->next; p != &dentry->d_subdirs; p = p->next) { | |
161 | struct dentry *next = list_entry(p, struct dentry, d_u.d_child); | |
162 | spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); | |
163 | if (!simple_positive(next)) { | |
164 | spin_unlock(&next->d_lock); | |
165 | continue; | |
166 | } | |
1da177e4 | 167 | |
5f99f4e7 AV |
168 | spin_unlock(&next->d_lock); |
169 | spin_unlock(&dentry->d_lock); | |
170 | if (!dir_emit(ctx, next->d_name.name, next->d_name.len, | |
171 | next->d_inode->i_ino, dt_type(next->d_inode))) | |
172 | return 0; | |
173 | spin_lock(&dentry->d_lock); | |
174 | spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); | |
175 | /* next is still alive */ | |
176 | list_move(q, p); | |
177 | spin_unlock(&next->d_lock); | |
178 | p = q; | |
179 | ctx->pos++; | |
1da177e4 | 180 | } |
5f99f4e7 | 181 | spin_unlock(&dentry->d_lock); |
1da177e4 LT |
182 | return 0; |
183 | } | |
12f38872 | 184 | EXPORT_SYMBOL(dcache_readdir); |
1da177e4 LT |
185 | |
186 | ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos) | |
187 | { | |
188 | return -EISDIR; | |
189 | } | |
12f38872 | 190 | EXPORT_SYMBOL(generic_read_dir); |
1da177e4 | 191 | |
4b6f5d20 | 192 | const struct file_operations simple_dir_operations = { |
1da177e4 LT |
193 | .open = dcache_dir_open, |
194 | .release = dcache_dir_close, | |
195 | .llseek = dcache_dir_lseek, | |
196 | .read = generic_read_dir, | |
5f99f4e7 | 197 | .iterate = dcache_readdir, |
1b061d92 | 198 | .fsync = noop_fsync, |
1da177e4 | 199 | }; |
12f38872 | 200 | EXPORT_SYMBOL(simple_dir_operations); |
1da177e4 | 201 | |
92e1d5be | 202 | const struct inode_operations simple_dir_inode_operations = { |
1da177e4 LT |
203 | .lookup = simple_lookup, |
204 | }; | |
12f38872 | 205 | EXPORT_SYMBOL(simple_dir_inode_operations); |
1da177e4 | 206 | |
759b9775 HD |
207 | static const struct super_operations simple_super_operations = { |
208 | .statfs = simple_statfs, | |
209 | }; | |
210 | ||
1da177e4 LT |
211 | /* |
212 | * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that | |
213 | * will never be mountable) | |
214 | */ | |
51139ada | 215 | struct dentry *mount_pseudo(struct file_system_type *fs_type, char *name, |
c74a1cbb AV |
216 | const struct super_operations *ops, |
217 | const struct dentry_operations *dops, unsigned long magic) | |
1da177e4 | 218 | { |
9249e17f | 219 | struct super_block *s; |
1da177e4 LT |
220 | struct dentry *dentry; |
221 | struct inode *root; | |
26fe5750 | 222 | struct qstr d_name = QSTR_INIT(name, strlen(name)); |
1da177e4 | 223 | |
9249e17f | 224 | s = sget(fs_type, NULL, set_anon_super, MS_NOUSER, NULL); |
1da177e4 | 225 | if (IS_ERR(s)) |
51139ada | 226 | return ERR_CAST(s); |
1da177e4 | 227 | |
89a4eb4b | 228 | s->s_maxbytes = MAX_LFS_FILESIZE; |
3971e1a9 AN |
229 | s->s_blocksize = PAGE_SIZE; |
230 | s->s_blocksize_bits = PAGE_SHIFT; | |
1da177e4 | 231 | s->s_magic = magic; |
759b9775 | 232 | s->s_op = ops ? ops : &simple_super_operations; |
1da177e4 LT |
233 | s->s_time_gran = 1; |
234 | root = new_inode(s); | |
235 | if (!root) | |
236 | goto Enomem; | |
1a1c9bb4 JL |
237 | /* |
238 | * since this is the first inode, make it number 1. New inodes created | |
239 | * after this must take care not to collide with it (by passing | |
240 | * max_reserved of 1 to iunique). | |
241 | */ | |
242 | root->i_ino = 1; | |
1da177e4 | 243 | root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR; |
1da177e4 | 244 | root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME; |
a4464dbc | 245 | dentry = __d_alloc(s, &d_name); |
1da177e4 LT |
246 | if (!dentry) { |
247 | iput(root); | |
248 | goto Enomem; | |
249 | } | |
1da177e4 LT |
250 | d_instantiate(dentry, root); |
251 | s->s_root = dentry; | |
c74a1cbb | 252 | s->s_d_op = dops; |
1da177e4 | 253 | s->s_flags |= MS_ACTIVE; |
51139ada | 254 | return dget(s->s_root); |
1da177e4 LT |
255 | |
256 | Enomem: | |
6f5bbff9 | 257 | deactivate_locked_super(s); |
51139ada | 258 | return ERR_PTR(-ENOMEM); |
1da177e4 | 259 | } |
12f38872 | 260 | EXPORT_SYMBOL(mount_pseudo); |
1da177e4 | 261 | |
20955e89 SB |
262 | int simple_open(struct inode *inode, struct file *file) |
263 | { | |
264 | if (inode->i_private) | |
265 | file->private_data = inode->i_private; | |
266 | return 0; | |
267 | } | |
12f38872 | 268 | EXPORT_SYMBOL(simple_open); |
20955e89 | 269 | |
1da177e4 LT |
270 | int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
271 | { | |
272 | struct inode *inode = old_dentry->d_inode; | |
273 | ||
274 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
d8c76e6f | 275 | inc_nlink(inode); |
7de9c6ee | 276 | ihold(inode); |
1da177e4 LT |
277 | dget(dentry); |
278 | d_instantiate(dentry, inode); | |
279 | return 0; | |
280 | } | |
12f38872 | 281 | EXPORT_SYMBOL(simple_link); |
1da177e4 | 282 | |
1da177e4 LT |
283 | int simple_empty(struct dentry *dentry) |
284 | { | |
285 | struct dentry *child; | |
286 | int ret = 0; | |
287 | ||
2fd6b7f5 | 288 | spin_lock(&dentry->d_lock); |
da502956 NP |
289 | list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) { |
290 | spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED); | |
291 | if (simple_positive(child)) { | |
292 | spin_unlock(&child->d_lock); | |
1da177e4 | 293 | goto out; |
da502956 NP |
294 | } |
295 | spin_unlock(&child->d_lock); | |
296 | } | |
1da177e4 LT |
297 | ret = 1; |
298 | out: | |
2fd6b7f5 | 299 | spin_unlock(&dentry->d_lock); |
1da177e4 LT |
300 | return ret; |
301 | } | |
12f38872 | 302 | EXPORT_SYMBOL(simple_empty); |
1da177e4 LT |
303 | |
304 | int simple_unlink(struct inode *dir, struct dentry *dentry) | |
305 | { | |
306 | struct inode *inode = dentry->d_inode; | |
307 | ||
308 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
9a53c3a7 | 309 | drop_nlink(inode); |
1da177e4 LT |
310 | dput(dentry); |
311 | return 0; | |
312 | } | |
12f38872 | 313 | EXPORT_SYMBOL(simple_unlink); |
1da177e4 LT |
314 | |
315 | int simple_rmdir(struct inode *dir, struct dentry *dentry) | |
316 | { | |
317 | if (!simple_empty(dentry)) | |
318 | return -ENOTEMPTY; | |
319 | ||
9a53c3a7 | 320 | drop_nlink(dentry->d_inode); |
1da177e4 | 321 | simple_unlink(dir, dentry); |
9a53c3a7 | 322 | drop_nlink(dir); |
1da177e4 LT |
323 | return 0; |
324 | } | |
12f38872 | 325 | EXPORT_SYMBOL(simple_rmdir); |
1da177e4 LT |
326 | |
327 | int simple_rename(struct inode *old_dir, struct dentry *old_dentry, | |
328 | struct inode *new_dir, struct dentry *new_dentry) | |
329 | { | |
330 | struct inode *inode = old_dentry->d_inode; | |
331 | int they_are_dirs = S_ISDIR(old_dentry->d_inode->i_mode); | |
332 | ||
333 | if (!simple_empty(new_dentry)) | |
334 | return -ENOTEMPTY; | |
335 | ||
336 | if (new_dentry->d_inode) { | |
337 | simple_unlink(new_dir, new_dentry); | |
841590ce AV |
338 | if (they_are_dirs) { |
339 | drop_nlink(new_dentry->d_inode); | |
9a53c3a7 | 340 | drop_nlink(old_dir); |
841590ce | 341 | } |
1da177e4 | 342 | } else if (they_are_dirs) { |
9a53c3a7 | 343 | drop_nlink(old_dir); |
d8c76e6f | 344 | inc_nlink(new_dir); |
1da177e4 LT |
345 | } |
346 | ||
347 | old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime = | |
348 | new_dir->i_mtime = inode->i_ctime = CURRENT_TIME; | |
349 | ||
350 | return 0; | |
351 | } | |
12f38872 | 352 | EXPORT_SYMBOL(simple_rename); |
1da177e4 | 353 | |
7bb46a67 | 354 | /** |
eef2380c | 355 | * simple_setattr - setattr for simple filesystem |
7bb46a67 | 356 | * @dentry: dentry |
357 | * @iattr: iattr structure | |
358 | * | |
359 | * Returns 0 on success, -error on failure. | |
360 | * | |
eef2380c CH |
361 | * simple_setattr is a simple ->setattr implementation without a proper |
362 | * implementation of size changes. | |
363 | * | |
364 | * It can either be used for in-memory filesystems or special files | |
365 | * on simple regular filesystems. Anything that needs to change on-disk | |
366 | * or wire state on size changes needs its own setattr method. | |
7bb46a67 | 367 | */ |
368 | int simple_setattr(struct dentry *dentry, struct iattr *iattr) | |
369 | { | |
370 | struct inode *inode = dentry->d_inode; | |
371 | int error; | |
372 | ||
373 | error = inode_change_ok(inode, iattr); | |
374 | if (error) | |
375 | return error; | |
376 | ||
2c27c65e CH |
377 | if (iattr->ia_valid & ATTR_SIZE) |
378 | truncate_setsize(inode, iattr->ia_size); | |
6a1a90ad | 379 | setattr_copy(inode, iattr); |
eef2380c CH |
380 | mark_inode_dirty(inode); |
381 | return 0; | |
7bb46a67 | 382 | } |
383 | EXPORT_SYMBOL(simple_setattr); | |
384 | ||
1da177e4 LT |
385 | int simple_readpage(struct file *file, struct page *page) |
386 | { | |
c0d92cbc | 387 | clear_highpage(page); |
1da177e4 LT |
388 | flush_dcache_page(page); |
389 | SetPageUptodate(page); | |
1da177e4 LT |
390 | unlock_page(page); |
391 | return 0; | |
392 | } | |
12f38872 | 393 | EXPORT_SYMBOL(simple_readpage); |
1da177e4 | 394 | |
afddba49 NP |
395 | int simple_write_begin(struct file *file, struct address_space *mapping, |
396 | loff_t pos, unsigned len, unsigned flags, | |
397 | struct page **pagep, void **fsdata) | |
398 | { | |
399 | struct page *page; | |
400 | pgoff_t index; | |
afddba49 NP |
401 | |
402 | index = pos >> PAGE_CACHE_SHIFT; | |
afddba49 | 403 | |
54566b2c | 404 | page = grab_cache_page_write_begin(mapping, index, flags); |
afddba49 NP |
405 | if (!page) |
406 | return -ENOMEM; | |
407 | ||
408 | *pagep = page; | |
409 | ||
193cf4b9 BH |
410 | if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) { |
411 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
412 | ||
413 | zero_user_segments(page, 0, from, from + len, PAGE_CACHE_SIZE); | |
414 | } | |
415 | return 0; | |
afddba49 | 416 | } |
12f38872 | 417 | EXPORT_SYMBOL(simple_write_begin); |
afddba49 | 418 | |
ad2a722f BH |
419 | /** |
420 | * simple_write_end - .write_end helper for non-block-device FSes | |
421 | * @available: See .write_end of address_space_operations | |
422 | * @file: " | |
423 | * @mapping: " | |
424 | * @pos: " | |
425 | * @len: " | |
426 | * @copied: " | |
427 | * @page: " | |
428 | * @fsdata: " | |
429 | * | |
430 | * simple_write_end does the minimum needed for updating a page after writing is | |
431 | * done. It has the same API signature as the .write_end of | |
432 | * address_space_operations vector. So it can just be set onto .write_end for | |
433 | * FSes that don't need any other processing. i_mutex is assumed to be held. | |
434 | * Block based filesystems should use generic_write_end(). | |
435 | * NOTE: Even though i_size might get updated by this function, mark_inode_dirty | |
436 | * is not called, so a filesystem that actually does store data in .write_inode | |
437 | * should extend on what's done here with a call to mark_inode_dirty() in the | |
438 | * case that i_size has changed. | |
439 | */ | |
afddba49 NP |
440 | int simple_write_end(struct file *file, struct address_space *mapping, |
441 | loff_t pos, unsigned len, unsigned copied, | |
442 | struct page *page, void *fsdata) | |
443 | { | |
ad2a722f BH |
444 | struct inode *inode = page->mapping->host; |
445 | loff_t last_pos = pos + copied; | |
afddba49 NP |
446 | |
447 | /* zero the stale part of the page if we did a short copy */ | |
448 | if (copied < len) { | |
ad2a722f BH |
449 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
450 | ||
451 | zero_user(page, from + copied, len - copied); | |
afddba49 NP |
452 | } |
453 | ||
ad2a722f BH |
454 | if (!PageUptodate(page)) |
455 | SetPageUptodate(page); | |
456 | /* | |
457 | * No need to use i_size_read() here, the i_size | |
458 | * cannot change under us because we hold the i_mutex. | |
459 | */ | |
460 | if (last_pos > inode->i_size) | |
461 | i_size_write(inode, last_pos); | |
afddba49 | 462 | |
ad2a722f | 463 | set_page_dirty(page); |
afddba49 NP |
464 | unlock_page(page); |
465 | page_cache_release(page); | |
466 | ||
467 | return copied; | |
468 | } | |
12f38872 | 469 | EXPORT_SYMBOL(simple_write_end); |
afddba49 | 470 | |
1a1c9bb4 JL |
471 | /* |
472 | * the inodes created here are not hashed. If you use iunique to generate | |
473 | * unique inode values later for this filesystem, then you must take care | |
474 | * to pass it an appropriate max_reserved value to avoid collisions. | |
475 | */ | |
7d683a09 RS |
476 | int simple_fill_super(struct super_block *s, unsigned long magic, |
477 | struct tree_descr *files) | |
1da177e4 | 478 | { |
1da177e4 LT |
479 | struct inode *inode; |
480 | struct dentry *root; | |
481 | struct dentry *dentry; | |
482 | int i; | |
483 | ||
484 | s->s_blocksize = PAGE_CACHE_SIZE; | |
485 | s->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
486 | s->s_magic = magic; | |
759b9775 | 487 | s->s_op = &simple_super_operations; |
1da177e4 LT |
488 | s->s_time_gran = 1; |
489 | ||
490 | inode = new_inode(s); | |
491 | if (!inode) | |
492 | return -ENOMEM; | |
1a1c9bb4 JL |
493 | /* |
494 | * because the root inode is 1, the files array must not contain an | |
495 | * entry at index 1 | |
496 | */ | |
497 | inode->i_ino = 1; | |
1da177e4 | 498 | inode->i_mode = S_IFDIR | 0755; |
1da177e4 LT |
499 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
500 | inode->i_op = &simple_dir_inode_operations; | |
501 | inode->i_fop = &simple_dir_operations; | |
bfe86848 | 502 | set_nlink(inode, 2); |
48fde701 AV |
503 | root = d_make_root(inode); |
504 | if (!root) | |
1da177e4 | 505 | return -ENOMEM; |
1da177e4 LT |
506 | for (i = 0; !files->name || files->name[0]; i++, files++) { |
507 | if (!files->name) | |
508 | continue; | |
1a1c9bb4 JL |
509 | |
510 | /* warn if it tries to conflict with the root inode */ | |
511 | if (unlikely(i == 1)) | |
512 | printk(KERN_WARNING "%s: %s passed in a files array" | |
513 | "with an index of 1!\n", __func__, | |
514 | s->s_type->name); | |
515 | ||
1da177e4 LT |
516 | dentry = d_alloc_name(root, files->name); |
517 | if (!dentry) | |
518 | goto out; | |
519 | inode = new_inode(s); | |
32096ea1 KK |
520 | if (!inode) { |
521 | dput(dentry); | |
1da177e4 | 522 | goto out; |
32096ea1 | 523 | } |
1da177e4 | 524 | inode->i_mode = S_IFREG | files->mode; |
1da177e4 LT |
525 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
526 | inode->i_fop = files->ops; | |
527 | inode->i_ino = i; | |
528 | d_add(dentry, inode); | |
529 | } | |
530 | s->s_root = root; | |
531 | return 0; | |
532 | out: | |
533 | d_genocide(root); | |
640946f2 | 534 | shrink_dcache_parent(root); |
1da177e4 LT |
535 | dput(root); |
536 | return -ENOMEM; | |
537 | } | |
12f38872 | 538 | EXPORT_SYMBOL(simple_fill_super); |
1da177e4 LT |
539 | |
540 | static DEFINE_SPINLOCK(pin_fs_lock); | |
541 | ||
1f5ce9e9 | 542 | int simple_pin_fs(struct file_system_type *type, struct vfsmount **mount, int *count) |
1da177e4 LT |
543 | { |
544 | struct vfsmount *mnt = NULL; | |
545 | spin_lock(&pin_fs_lock); | |
546 | if (unlikely(!*mount)) { | |
547 | spin_unlock(&pin_fs_lock); | |
2452992a | 548 | mnt = vfs_kern_mount(type, MS_KERNMOUNT, type->name, NULL); |
1da177e4 LT |
549 | if (IS_ERR(mnt)) |
550 | return PTR_ERR(mnt); | |
551 | spin_lock(&pin_fs_lock); | |
552 | if (!*mount) | |
553 | *mount = mnt; | |
554 | } | |
555 | mntget(*mount); | |
556 | ++*count; | |
557 | spin_unlock(&pin_fs_lock); | |
558 | mntput(mnt); | |
559 | return 0; | |
560 | } | |
12f38872 | 561 | EXPORT_SYMBOL(simple_pin_fs); |
1da177e4 LT |
562 | |
563 | void simple_release_fs(struct vfsmount **mount, int *count) | |
564 | { | |
565 | struct vfsmount *mnt; | |
566 | spin_lock(&pin_fs_lock); | |
567 | mnt = *mount; | |
568 | if (!--*count) | |
569 | *mount = NULL; | |
570 | spin_unlock(&pin_fs_lock); | |
571 | mntput(mnt); | |
572 | } | |
12f38872 | 573 | EXPORT_SYMBOL(simple_release_fs); |
1da177e4 | 574 | |
6d1029b5 AM |
575 | /** |
576 | * simple_read_from_buffer - copy data from the buffer to user space | |
577 | * @to: the user space buffer to read to | |
578 | * @count: the maximum number of bytes to read | |
579 | * @ppos: the current position in the buffer | |
580 | * @from: the buffer to read from | |
581 | * @available: the size of the buffer | |
582 | * | |
583 | * The simple_read_from_buffer() function reads up to @count bytes from the | |
584 | * buffer @from at offset @ppos into the user space address starting at @to. | |
585 | * | |
586 | * On success, the number of bytes read is returned and the offset @ppos is | |
587 | * advanced by this number, or negative value is returned on error. | |
588 | **/ | |
1da177e4 LT |
589 | ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, |
590 | const void *from, size_t available) | |
591 | { | |
592 | loff_t pos = *ppos; | |
14be2746 SR |
593 | size_t ret; |
594 | ||
1da177e4 LT |
595 | if (pos < 0) |
596 | return -EINVAL; | |
14be2746 | 597 | if (pos >= available || !count) |
1da177e4 LT |
598 | return 0; |
599 | if (count > available - pos) | |
600 | count = available - pos; | |
14be2746 SR |
601 | ret = copy_to_user(to, from + pos, count); |
602 | if (ret == count) | |
1da177e4 | 603 | return -EFAULT; |
14be2746 | 604 | count -= ret; |
1da177e4 LT |
605 | *ppos = pos + count; |
606 | return count; | |
607 | } | |
12f38872 | 608 | EXPORT_SYMBOL(simple_read_from_buffer); |
1da177e4 | 609 | |
6a727b43 JS |
610 | /** |
611 | * simple_write_to_buffer - copy data from user space to the buffer | |
612 | * @to: the buffer to write to | |
613 | * @available: the size of the buffer | |
614 | * @ppos: the current position in the buffer | |
615 | * @from: the user space buffer to read from | |
616 | * @count: the maximum number of bytes to read | |
617 | * | |
618 | * The simple_write_to_buffer() function reads up to @count bytes from the user | |
619 | * space address starting at @from into the buffer @to at offset @ppos. | |
620 | * | |
621 | * On success, the number of bytes written is returned and the offset @ppos is | |
622 | * advanced by this number, or negative value is returned on error. | |
623 | **/ | |
624 | ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, | |
625 | const void __user *from, size_t count) | |
626 | { | |
627 | loff_t pos = *ppos; | |
628 | size_t res; | |
629 | ||
630 | if (pos < 0) | |
631 | return -EINVAL; | |
632 | if (pos >= available || !count) | |
633 | return 0; | |
634 | if (count > available - pos) | |
635 | count = available - pos; | |
636 | res = copy_from_user(to + pos, from, count); | |
637 | if (res == count) | |
638 | return -EFAULT; | |
639 | count -= res; | |
640 | *ppos = pos + count; | |
641 | return count; | |
642 | } | |
12f38872 | 643 | EXPORT_SYMBOL(simple_write_to_buffer); |
6a727b43 | 644 | |
6d1029b5 AM |
645 | /** |
646 | * memory_read_from_buffer - copy data from the buffer | |
647 | * @to: the kernel space buffer to read to | |
648 | * @count: the maximum number of bytes to read | |
649 | * @ppos: the current position in the buffer | |
650 | * @from: the buffer to read from | |
651 | * @available: the size of the buffer | |
652 | * | |
653 | * The memory_read_from_buffer() function reads up to @count bytes from the | |
654 | * buffer @from at offset @ppos into the kernel space address starting at @to. | |
655 | * | |
656 | * On success, the number of bytes read is returned and the offset @ppos is | |
657 | * advanced by this number, or negative value is returned on error. | |
658 | **/ | |
93b07113 AM |
659 | ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, |
660 | const void *from, size_t available) | |
661 | { | |
662 | loff_t pos = *ppos; | |
663 | ||
664 | if (pos < 0) | |
665 | return -EINVAL; | |
666 | if (pos >= available) | |
667 | return 0; | |
668 | if (count > available - pos) | |
669 | count = available - pos; | |
670 | memcpy(to, from + pos, count); | |
671 | *ppos = pos + count; | |
672 | ||
673 | return count; | |
674 | } | |
12f38872 | 675 | EXPORT_SYMBOL(memory_read_from_buffer); |
93b07113 | 676 | |
1da177e4 LT |
677 | /* |
678 | * Transaction based IO. | |
679 | * The file expects a single write which triggers the transaction, and then | |
680 | * possibly a read which collects the result - which is stored in a | |
681 | * file-local buffer. | |
682 | */ | |
76791ab2 IM |
683 | |
684 | void simple_transaction_set(struct file *file, size_t n) | |
685 | { | |
686 | struct simple_transaction_argresp *ar = file->private_data; | |
687 | ||
688 | BUG_ON(n > SIMPLE_TRANSACTION_LIMIT); | |
689 | ||
690 | /* | |
691 | * The barrier ensures that ar->size will really remain zero until | |
692 | * ar->data is ready for reading. | |
693 | */ | |
694 | smp_mb(); | |
695 | ar->size = n; | |
696 | } | |
12f38872 | 697 | EXPORT_SYMBOL(simple_transaction_set); |
76791ab2 | 698 | |
1da177e4 LT |
699 | char *simple_transaction_get(struct file *file, const char __user *buf, size_t size) |
700 | { | |
701 | struct simple_transaction_argresp *ar; | |
702 | static DEFINE_SPINLOCK(simple_transaction_lock); | |
703 | ||
704 | if (size > SIMPLE_TRANSACTION_LIMIT - 1) | |
705 | return ERR_PTR(-EFBIG); | |
706 | ||
707 | ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL); | |
708 | if (!ar) | |
709 | return ERR_PTR(-ENOMEM); | |
710 | ||
711 | spin_lock(&simple_transaction_lock); | |
712 | ||
713 | /* only one write allowed per open */ | |
714 | if (file->private_data) { | |
715 | spin_unlock(&simple_transaction_lock); | |
716 | free_page((unsigned long)ar); | |
717 | return ERR_PTR(-EBUSY); | |
718 | } | |
719 | ||
720 | file->private_data = ar; | |
721 | ||
722 | spin_unlock(&simple_transaction_lock); | |
723 | ||
724 | if (copy_from_user(ar->data, buf, size)) | |
725 | return ERR_PTR(-EFAULT); | |
726 | ||
727 | return ar->data; | |
728 | } | |
12f38872 | 729 | EXPORT_SYMBOL(simple_transaction_get); |
1da177e4 LT |
730 | |
731 | ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos) | |
732 | { | |
733 | struct simple_transaction_argresp *ar = file->private_data; | |
734 | ||
735 | if (!ar) | |
736 | return 0; | |
737 | return simple_read_from_buffer(buf, size, pos, ar->data, ar->size); | |
738 | } | |
12f38872 | 739 | EXPORT_SYMBOL(simple_transaction_read); |
1da177e4 LT |
740 | |
741 | int simple_transaction_release(struct inode *inode, struct file *file) | |
742 | { | |
743 | free_page((unsigned long)file->private_data); | |
744 | return 0; | |
745 | } | |
12f38872 | 746 | EXPORT_SYMBOL(simple_transaction_release); |
1da177e4 | 747 | |
acaefc25 AB |
748 | /* Simple attribute files */ |
749 | ||
750 | struct simple_attr { | |
8b88b099 CH |
751 | int (*get)(void *, u64 *); |
752 | int (*set)(void *, u64); | |
acaefc25 AB |
753 | char get_buf[24]; /* enough to store a u64 and "\n\0" */ |
754 | char set_buf[24]; | |
755 | void *data; | |
756 | const char *fmt; /* format for read operation */ | |
7cf34c76 | 757 | struct mutex mutex; /* protects access to these buffers */ |
acaefc25 AB |
758 | }; |
759 | ||
760 | /* simple_attr_open is called by an actual attribute open file operation | |
761 | * to set the attribute specific access operations. */ | |
762 | int simple_attr_open(struct inode *inode, struct file *file, | |
8b88b099 | 763 | int (*get)(void *, u64 *), int (*set)(void *, u64), |
acaefc25 AB |
764 | const char *fmt) |
765 | { | |
766 | struct simple_attr *attr; | |
767 | ||
768 | attr = kmalloc(sizeof(*attr), GFP_KERNEL); | |
769 | if (!attr) | |
770 | return -ENOMEM; | |
771 | ||
772 | attr->get = get; | |
773 | attr->set = set; | |
8e18e294 | 774 | attr->data = inode->i_private; |
acaefc25 | 775 | attr->fmt = fmt; |
7cf34c76 | 776 | mutex_init(&attr->mutex); |
acaefc25 AB |
777 | |
778 | file->private_data = attr; | |
779 | ||
780 | return nonseekable_open(inode, file); | |
781 | } | |
12f38872 | 782 | EXPORT_SYMBOL_GPL(simple_attr_open); |
acaefc25 | 783 | |
74bedc4d | 784 | int simple_attr_release(struct inode *inode, struct file *file) |
acaefc25 AB |
785 | { |
786 | kfree(file->private_data); | |
787 | return 0; | |
788 | } | |
12f38872 | 789 | EXPORT_SYMBOL_GPL(simple_attr_release); /* GPL-only? This? Really? */ |
acaefc25 AB |
790 | |
791 | /* read from the buffer that is filled with the get function */ | |
792 | ssize_t simple_attr_read(struct file *file, char __user *buf, | |
793 | size_t len, loff_t *ppos) | |
794 | { | |
795 | struct simple_attr *attr; | |
796 | size_t size; | |
797 | ssize_t ret; | |
798 | ||
799 | attr = file->private_data; | |
800 | ||
801 | if (!attr->get) | |
802 | return -EACCES; | |
803 | ||
9261303a CH |
804 | ret = mutex_lock_interruptible(&attr->mutex); |
805 | if (ret) | |
806 | return ret; | |
807 | ||
8b88b099 | 808 | if (*ppos) { /* continued read */ |
acaefc25 | 809 | size = strlen(attr->get_buf); |
8b88b099 CH |
810 | } else { /* first read */ |
811 | u64 val; | |
812 | ret = attr->get(attr->data, &val); | |
813 | if (ret) | |
814 | goto out; | |
815 | ||
acaefc25 | 816 | size = scnprintf(attr->get_buf, sizeof(attr->get_buf), |
8b88b099 CH |
817 | attr->fmt, (unsigned long long)val); |
818 | } | |
acaefc25 AB |
819 | |
820 | ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size); | |
8b88b099 | 821 | out: |
7cf34c76 | 822 | mutex_unlock(&attr->mutex); |
acaefc25 AB |
823 | return ret; |
824 | } | |
12f38872 | 825 | EXPORT_SYMBOL_GPL(simple_attr_read); |
acaefc25 AB |
826 | |
827 | /* interpret the buffer as a number to call the set function with */ | |
828 | ssize_t simple_attr_write(struct file *file, const char __user *buf, | |
829 | size_t len, loff_t *ppos) | |
830 | { | |
831 | struct simple_attr *attr; | |
832 | u64 val; | |
833 | size_t size; | |
834 | ssize_t ret; | |
835 | ||
836 | attr = file->private_data; | |
acaefc25 AB |
837 | if (!attr->set) |
838 | return -EACCES; | |
839 | ||
9261303a CH |
840 | ret = mutex_lock_interruptible(&attr->mutex); |
841 | if (ret) | |
842 | return ret; | |
843 | ||
acaefc25 AB |
844 | ret = -EFAULT; |
845 | size = min(sizeof(attr->set_buf) - 1, len); | |
846 | if (copy_from_user(attr->set_buf, buf, size)) | |
847 | goto out; | |
848 | ||
acaefc25 | 849 | attr->set_buf[size] = '\0'; |
f7b88631 | 850 | val = simple_strtoll(attr->set_buf, NULL, 0); |
05cc0cee WF |
851 | ret = attr->set(attr->data, val); |
852 | if (ret == 0) | |
853 | ret = len; /* on success, claim we got the whole input */ | |
acaefc25 | 854 | out: |
7cf34c76 | 855 | mutex_unlock(&attr->mutex); |
acaefc25 AB |
856 | return ret; |
857 | } | |
12f38872 | 858 | EXPORT_SYMBOL_GPL(simple_attr_write); |
acaefc25 | 859 | |
2596110a CH |
860 | /** |
861 | * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation | |
862 | * @sb: filesystem to do the file handle conversion on | |
863 | * @fid: file handle to convert | |
864 | * @fh_len: length of the file handle in bytes | |
865 | * @fh_type: type of file handle | |
866 | * @get_inode: filesystem callback to retrieve inode | |
867 | * | |
868 | * This function decodes @fid as long as it has one of the well-known | |
869 | * Linux filehandle types and calls @get_inode on it to retrieve the | |
870 | * inode for the object specified in the file handle. | |
871 | */ | |
872 | struct dentry *generic_fh_to_dentry(struct super_block *sb, struct fid *fid, | |
873 | int fh_len, int fh_type, struct inode *(*get_inode) | |
874 | (struct super_block *sb, u64 ino, u32 gen)) | |
875 | { | |
876 | struct inode *inode = NULL; | |
877 | ||
878 | if (fh_len < 2) | |
879 | return NULL; | |
880 | ||
881 | switch (fh_type) { | |
882 | case FILEID_INO32_GEN: | |
883 | case FILEID_INO32_GEN_PARENT: | |
884 | inode = get_inode(sb, fid->i32.ino, fid->i32.gen); | |
885 | break; | |
886 | } | |
887 | ||
4ea3ada2 | 888 | return d_obtain_alias(inode); |
2596110a CH |
889 | } |
890 | EXPORT_SYMBOL_GPL(generic_fh_to_dentry); | |
891 | ||
892 | /** | |
ca186830 | 893 | * generic_fh_to_parent - generic helper for the fh_to_parent export operation |
2596110a CH |
894 | * @sb: filesystem to do the file handle conversion on |
895 | * @fid: file handle to convert | |
896 | * @fh_len: length of the file handle in bytes | |
897 | * @fh_type: type of file handle | |
898 | * @get_inode: filesystem callback to retrieve inode | |
899 | * | |
900 | * This function decodes @fid as long as it has one of the well-known | |
901 | * Linux filehandle types and calls @get_inode on it to retrieve the | |
902 | * inode for the _parent_ object specified in the file handle if it | |
903 | * is specified in the file handle, or NULL otherwise. | |
904 | */ | |
905 | struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid, | |
906 | int fh_len, int fh_type, struct inode *(*get_inode) | |
907 | (struct super_block *sb, u64 ino, u32 gen)) | |
908 | { | |
909 | struct inode *inode = NULL; | |
910 | ||
911 | if (fh_len <= 2) | |
912 | return NULL; | |
913 | ||
914 | switch (fh_type) { | |
915 | case FILEID_INO32_GEN_PARENT: | |
916 | inode = get_inode(sb, fid->i32.parent_ino, | |
917 | (fh_len > 3 ? fid->i32.parent_gen : 0)); | |
918 | break; | |
919 | } | |
920 | ||
4ea3ada2 | 921 | return d_obtain_alias(inode); |
2596110a CH |
922 | } |
923 | EXPORT_SYMBOL_GPL(generic_fh_to_parent); | |
924 | ||
1b061d92 CH |
925 | /** |
926 | * generic_file_fsync - generic fsync implementation for simple filesystems | |
927 | * @file: file to synchronize | |
928 | * @datasync: only synchronize essential metadata if true | |
929 | * | |
930 | * This is a generic implementation of the fsync method for simple | |
931 | * filesystems which track all non-inode metadata in the buffers list | |
932 | * hanging off the address_space structure. | |
933 | */ | |
02c24a82 JB |
934 | int generic_file_fsync(struct file *file, loff_t start, loff_t end, |
935 | int datasync) | |
d5aacad5 | 936 | { |
7ea80859 | 937 | struct inode *inode = file->f_mapping->host; |
d5aacad5 AV |
938 | int err; |
939 | int ret; | |
940 | ||
02c24a82 JB |
941 | err = filemap_write_and_wait_range(inode->i_mapping, start, end); |
942 | if (err) | |
943 | return err; | |
944 | ||
945 | mutex_lock(&inode->i_mutex); | |
d5aacad5 AV |
946 | ret = sync_mapping_buffers(inode->i_mapping); |
947 | if (!(inode->i_state & I_DIRTY)) | |
02c24a82 | 948 | goto out; |
d5aacad5 | 949 | if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) |
02c24a82 | 950 | goto out; |
d5aacad5 | 951 | |
c3765016 | 952 | err = sync_inode_metadata(inode, 1); |
d5aacad5 AV |
953 | if (ret == 0) |
954 | ret = err; | |
02c24a82 JB |
955 | out: |
956 | mutex_unlock(&inode->i_mutex); | |
d5aacad5 AV |
957 | return ret; |
958 | } | |
1b061d92 CH |
959 | EXPORT_SYMBOL(generic_file_fsync); |
960 | ||
30ca22c7 PL |
961 | /** |
962 | * generic_check_addressable - Check addressability of file system | |
963 | * @blocksize_bits: log of file system block size | |
964 | * @num_blocks: number of blocks in file system | |
965 | * | |
966 | * Determine whether a file system with @num_blocks blocks (and a | |
967 | * block size of 2**@blocksize_bits) is addressable by the sector_t | |
968 | * and page cache of the system. Return 0 if so and -EFBIG otherwise. | |
969 | */ | |
970 | int generic_check_addressable(unsigned blocksize_bits, u64 num_blocks) | |
971 | { | |
972 | u64 last_fs_block = num_blocks - 1; | |
a33f13ef JB |
973 | u64 last_fs_page = |
974 | last_fs_block >> (PAGE_CACHE_SHIFT - blocksize_bits); | |
30ca22c7 PL |
975 | |
976 | if (unlikely(num_blocks == 0)) | |
977 | return 0; | |
978 | ||
979 | if ((blocksize_bits < 9) || (blocksize_bits > PAGE_CACHE_SHIFT)) | |
980 | return -EINVAL; | |
981 | ||
a33f13ef JB |
982 | if ((last_fs_block > (sector_t)(~0ULL) >> (blocksize_bits - 9)) || |
983 | (last_fs_page > (pgoff_t)(~0ULL))) { | |
30ca22c7 PL |
984 | return -EFBIG; |
985 | } | |
986 | return 0; | |
987 | } | |
988 | EXPORT_SYMBOL(generic_check_addressable); | |
989 | ||
1b061d92 CH |
990 | /* |
991 | * No-op implementation of ->fsync for in-memory filesystems. | |
992 | */ | |
02c24a82 | 993 | int noop_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
1b061d92 CH |
994 | { |
995 | return 0; | |
996 | } | |
1b061d92 | 997 | EXPORT_SYMBOL(noop_fsync); |
87dc800b AV |
998 | |
999 | void kfree_put_link(struct dentry *dentry, struct nameidata *nd, | |
1000 | void *cookie) | |
1001 | { | |
1002 | char *s = nd_get_link(nd); | |
1003 | if (!IS_ERR(s)) | |
1004 | kfree(s); | |
1005 | } | |
1006 | EXPORT_SYMBOL(kfree_put_link); | |
6987843f AV |
1007 | |
1008 | /* | |
1009 | * nop .set_page_dirty method so that people can use .page_mkwrite on | |
1010 | * anon inodes. | |
1011 | */ | |
1012 | static int anon_set_page_dirty(struct page *page) | |
1013 | { | |
1014 | return 0; | |
1015 | }; | |
1016 | ||
1017 | /* | |
1018 | * A single inode exists for all anon_inode files. Contrary to pipes, | |
1019 | * anon_inode inodes have no associated per-instance data, so we need | |
1020 | * only allocate one of them. | |
1021 | */ | |
1022 | struct inode *alloc_anon_inode(struct super_block *s) | |
1023 | { | |
1024 | static const struct address_space_operations anon_aops = { | |
1025 | .set_page_dirty = anon_set_page_dirty, | |
1026 | }; | |
1027 | struct inode *inode = new_inode_pseudo(s); | |
1028 | ||
1029 | if (!inode) | |
1030 | return ERR_PTR(-ENOMEM); | |
1031 | ||
1032 | inode->i_ino = get_next_ino(); | |
1033 | inode->i_mapping->a_ops = &anon_aops; | |
1034 | ||
1035 | /* | |
1036 | * Mark the inode dirty from the very beginning, | |
1037 | * that way it will never be moved to the dirty | |
1038 | * list because mark_inode_dirty() will think | |
1039 | * that it already _is_ on the dirty list. | |
1040 | */ | |
1041 | inode->i_state = I_DIRTY; | |
1042 | inode->i_mode = S_IRUSR | S_IWUSR; | |
1043 | inode->i_uid = current_fsuid(); | |
1044 | inode->i_gid = current_fsgid(); | |
1045 | inode->i_flags |= S_PRIVATE; | |
1046 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
1047 | return inode; | |
1048 | } | |
1049 | EXPORT_SYMBOL(alloc_anon_inode); |