1 // SPDX-License-Identifier: GPL-2.0-only <<
2 /* 1 /*
3 * fs/libfs.c 2 * fs/libfs.c
4 * Library for filesystems writers. 3 * Library for filesystems writers.
5 */ 4 */
6 5
7 #include <linux/blkdev.h> !! 6 #include <linux/module.h>
8 #include <linux/export.h> <<
9 #include <linux/pagemap.h> 7 #include <linux/pagemap.h>
10 #include <linux/slab.h> <<
11 #include <linux/cred.h> <<
12 #include <linux/mount.h> 8 #include <linux/mount.h>
13 #include <linux/vfs.h> 9 #include <linux/vfs.h>
14 #include <linux/quotaops.h> <<
15 #include <linux/mutex.h> 10 #include <linux/mutex.h>
16 #include <linux/namei.h> <<
17 #include <linux/exportfs.h> 11 #include <linux/exportfs.h>
18 #include <linux/iversion.h> <<
19 #include <linux/writeback.h> 12 #include <linux/writeback.h>
20 #include <linux/buffer_head.h> /* sync_mapping !! 13 #include <linux/buffer_head.h>
21 #include <linux/fs_context.h> !! 14
22 #include <linux/pseudo_fs.h> !! 15 #include <asm/uaccess.h>
23 #include <linux/fsnotify.h> !! 16
24 #include <linux/unicode.h> !! 17 int simple_getattr(struct vfsmount *mnt, struct dentry *dentry,
25 #include <linux/fscrypt.h> !! 18 struct kstat *stat)
26 #include <linux/pidfs.h> !! 19 {
27 !! 20 struct inode *inode = dentry->d_inode;
28 #include <linux/uaccess.h> !! 21 generic_fillattr(inode, stat);
29 !! 22 stat->blocks = inode->i_mapping->nrpages << (PAGE_CACHE_SHIFT - 9);
30 #include "internal.h" <<
31 <<
32 int simple_getattr(struct mnt_idmap *idmap, co <<
33 struct kstat *stat, u32 req <<
34 unsigned int query_flags) <<
35 { <<
36 struct inode *inode = d_inode(path->de <<
37 generic_fillattr(&nop_mnt_idmap, reque <<
38 stat->blocks = inode->i_mapping->nrpag <<
39 return 0; 23 return 0;
40 } 24 }
41 EXPORT_SYMBOL(simple_getattr); <<
42 25
43 int simple_statfs(struct dentry *dentry, struc 26 int simple_statfs(struct dentry *dentry, struct kstatfs *buf)
44 { 27 {
45 u64 id = huge_encode_dev(dentry->d_sb- <<
46 <<
47 buf->f_fsid = u64_to_fsid(id); <<
48 buf->f_type = dentry->d_sb->s_magic; 28 buf->f_type = dentry->d_sb->s_magic;
49 buf->f_bsize = PAGE_SIZE; !! 29 buf->f_bsize = PAGE_CACHE_SIZE;
50 buf->f_namelen = NAME_MAX; 30 buf->f_namelen = NAME_MAX;
51 return 0; 31 return 0;
52 } 32 }
53 EXPORT_SYMBOL(simple_statfs); <<
54 33
55 /* 34 /*
56 * Retaining negative dentries for an in-memor 35 * Retaining negative dentries for an in-memory filesystem just wastes
57 * memory and lookup time: arrange for them to 36 * memory and lookup time: arrange for them to be deleted immediately.
58 */ 37 */
59 int always_delete_dentry(const struct dentry * !! 38 static int simple_delete_dentry(struct dentry *dentry)
60 { 39 {
61 return 1; 40 return 1;
62 } 41 }
63 EXPORT_SYMBOL(always_delete_dentry); <<
64 <<
65 const struct dentry_operations simple_dentry_o <<
66 .d_delete = always_delete_dentry, <<
67 }; <<
68 EXPORT_SYMBOL(simple_dentry_operations); <<
69 42
70 /* 43 /*
71 * Lookup the data. This is trivial - if the d 44 * Lookup the data. This is trivial - if the dentry didn't already
72 * exist, we know it is negative. Set d_op to 45 * exist, we know it is negative. Set d_op to delete negative dentries.
73 */ 46 */
74 struct dentry *simple_lookup(struct inode *dir !! 47 struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
75 { 48 {
>> 49 static const struct dentry_operations simple_dentry_operations = {
>> 50 .d_delete = simple_delete_dentry,
>> 51 };
>> 52
76 if (dentry->d_name.len > NAME_MAX) 53 if (dentry->d_name.len > NAME_MAX)
77 return ERR_PTR(-ENAMETOOLONG); 54 return ERR_PTR(-ENAMETOOLONG);
78 if (!dentry->d_sb->s_d_op) !! 55 dentry->d_op = &simple_dentry_operations;
79 d_set_d_op(dentry, &simple_den <<
80 d_add(dentry, NULL); 56 d_add(dentry, NULL);
81 return NULL; 57 return NULL;
82 } 58 }
83 EXPORT_SYMBOL(simple_lookup); <<
84 59
>> 60 int simple_sync_file(struct file * file, struct dentry *dentry, int datasync)
>> 61 {
>> 62 return 0;
>> 63 }
>> 64
85 int dcache_dir_open(struct inode *inode, struc 65 int dcache_dir_open(struct inode *inode, struct file *file)
86 { 66 {
87 file->private_data = d_alloc_cursor(fi !! 67 static struct qstr cursor_name = {.len = 1, .name = "."};
>> 68
>> 69 file->private_data = d_alloc(file->f_path.dentry, &cursor_name);
88 70
89 return file->private_data ? 0 : -ENOME 71 return file->private_data ? 0 : -ENOMEM;
90 } 72 }
91 EXPORT_SYMBOL(dcache_dir_open); <<
92 73
93 int dcache_dir_close(struct inode *inode, stru 74 int dcache_dir_close(struct inode *inode, struct file *file)
94 { 75 {
95 dput(file->private_data); 76 dput(file->private_data);
96 return 0; 77 return 0;
97 } 78 }
98 EXPORT_SYMBOL(dcache_dir_close); <<
99 <<
100 /* parent is locked at least shared */ <<
101 /* <<
102 * Returns an element of siblings' list. <<
103 * We are looking for <count>th positive after <<
104 * found, dentry is grabbed and returned to ca <<
105 * If no such element exists, NULL is returned <<
106 */ <<
107 static struct dentry *scan_positives(struct de <<
108 struct <<
109 loff_t <<
110 struct <<
111 { <<
112 struct dentry *dentry = cursor->d_pare <<
113 <<
114 spin_lock(&dentry->d_lock); <<
115 while (*p) { <<
116 struct dentry *d = hlist_entry <<
117 p = &d->d_sib.next; <<
118 // we must at least skip curso <<
119 if (d->d_flags & DCACHE_DENTRY <<
120 continue; <<
121 if (simple_positive(d) && !--c <<
122 spin_lock_nested(&d->d <<
123 if (simple_positive(d) <<
124 found = dget_d <<
125 spin_unlock(&d->d_lock <<
126 if (likely(found)) <<
127 break; <<
128 count = 1; <<
129 } <<
130 if (need_resched()) { <<
131 if (!hlist_unhashed(&c <<
132 __hlist_del(&c <<
133 hlist_add_behind(&curs <<
134 p = &cursor->d_sib.nex <<
135 spin_unlock(&dentry->d <<
136 cond_resched(); <<
137 spin_lock(&dentry->d_l <<
138 } <<
139 } <<
140 spin_unlock(&dentry->d_lock); <<
141 dput(last); <<
142 return found; <<
143 } <<
144 79
145 loff_t dcache_dir_lseek(struct file *file, lof !! 80 loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
146 { 81 {
147 struct dentry *dentry = file->f_path.d !! 82 mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
148 switch (whence) { !! 83 switch (origin) {
149 case 1: 84 case 1:
150 offset += file->f_pos; 85 offset += file->f_pos;
151 fallthrough; <<
152 case 0: 86 case 0:
153 if (offset >= 0) 87 if (offset >= 0)
154 break; 88 break;
155 fallthrough; <<
156 default: 89 default:
>> 90 mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
157 return -EINVAL; 91 return -EINVAL;
158 } 92 }
159 if (offset != file->f_pos) { 93 if (offset != file->f_pos) {
160 struct dentry *cursor = file-> <<
161 struct dentry *to = NULL; <<
162 <<
163 inode_lock_shared(dentry->d_in <<
164 <<
165 if (offset > 2) <<
166 to = scan_positives(cu <<
167 of <<
168 spin_lock(&dentry->d_lock); <<
169 hlist_del_init(&cursor->d_sib) <<
170 if (to) <<
171 hlist_add_behind(&curs <<
172 spin_unlock(&dentry->d_lock); <<
173 dput(to); <<
174 <<
175 file->f_pos = offset; 94 file->f_pos = offset;
176 !! 95 if (file->f_pos >= 2) {
177 inode_unlock_shared(dentry->d_ !! 96 struct list_head *p;
>> 97 struct dentry *cursor = file->private_data;
>> 98 loff_t n = file->f_pos - 2;
>> 99
>> 100 spin_lock(&dcache_lock);
>> 101 list_del(&cursor->d_u.d_child);
>> 102 p = file->f_path.dentry->d_subdirs.next;
>> 103 while (n && p != &file->f_path.dentry->d_subdirs) {
>> 104 struct dentry *next;
>> 105 next = list_entry(p, struct dentry, d_u.d_child);
>> 106 if (!d_unhashed(next) && next->d_inode)
>> 107 n--;
>> 108 p = p->next;
>> 109 }
>> 110 list_add_tail(&cursor->d_u.d_child, p);
>> 111 spin_unlock(&dcache_lock);
>> 112 }
178 } 113 }
>> 114 mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
179 return offset; 115 return offset;
180 } 116 }
181 EXPORT_SYMBOL(dcache_dir_lseek); !! 117
>> 118 /* Relationship between i_mode and the DT_xxx types */
>> 119 static inline unsigned char dt_type(struct inode *inode)
>> 120 {
>> 121 return (inode->i_mode >> 12) & 15;
>> 122 }
182 123
183 /* 124 /*
184 * Directory is locked and all positive dentri 125 * Directory is locked and all positive dentries in it are safe, since
185 * for ramfs-type trees they can't go away wit 126 * for ramfs-type trees they can't go away without unlink() or rmdir(),
186 * both impossible due to the lock on director 127 * both impossible due to the lock on directory.
187 */ 128 */
188 129
189 int dcache_readdir(struct file *file, struct d !! 130 int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
190 { 131 {
191 struct dentry *dentry = file->f_path.d !! 132 struct dentry *dentry = filp->f_path.dentry;
192 struct dentry *cursor = file->private_ !! 133 struct dentry *cursor = filp->private_data;
193 struct dentry *next = NULL; !! 134 struct list_head *p, *q = &cursor->d_u.d_child;
194 struct hlist_node **p; !! 135 ino_t ino;
195 !! 136 int i = filp->f_pos;
196 if (!dir_emit_dots(file, ctx)) <<
197 return 0; <<
198 137
199 if (ctx->pos == 2) !! 138 switch (i) {
200 p = &dentry->d_children.first; !! 139 case 0:
201 else !! 140 ino = dentry->d_inode->i_ino;
202 p = &cursor->d_sib.next; !! 141 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
203 !! 142 break;
204 while ((next = scan_positives(cursor, !! 143 filp->f_pos++;
205 if (!dir_emit(ctx, next->d_nam !! 144 i++;
206 d_inode(next)->i !! 145 /* fallthrough */
207 fs_umode_to_dtyp !! 146 case 1:
208 break; !! 147 ino = parent_ino(dentry);
209 ctx->pos++; !! 148 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
210 p = &next->d_sib.next; !! 149 break;
>> 150 filp->f_pos++;
>> 151 i++;
>> 152 /* fallthrough */
>> 153 default:
>> 154 spin_lock(&dcache_lock);
>> 155 if (filp->f_pos == 2)
>> 156 list_move(q, &dentry->d_subdirs);
>> 157
>> 158 for (p=q->next; p != &dentry->d_subdirs; p=p->next) {
>> 159 struct dentry *next;
>> 160 next = list_entry(p, struct dentry, d_u.d_child);
>> 161 if (d_unhashed(next) || !next->d_inode)
>> 162 continue;
>> 163
>> 164 spin_unlock(&dcache_lock);
>> 165 if (filldir(dirent, next->d_name.name,
>> 166 next->d_name.len, filp->f_pos,
>> 167 next->d_inode->i_ino,
>> 168 dt_type(next->d_inode)) < 0)
>> 169 return 0;
>> 170 spin_lock(&dcache_lock);
>> 171 /* next is still alive */
>> 172 list_move(q, p);
>> 173 p = q;
>> 174 filp->f_pos++;
>> 175 }
>> 176 spin_unlock(&dcache_lock);
211 } 177 }
212 spin_lock(&dentry->d_lock); <<
213 hlist_del_init(&cursor->d_sib); <<
214 if (next) <<
215 hlist_add_before(&cursor->d_si <<
216 spin_unlock(&dentry->d_lock); <<
217 dput(next); <<
218 <<
219 return 0; 178 return 0;
220 } 179 }
221 EXPORT_SYMBOL(dcache_readdir); <<
222 180
223 ssize_t generic_read_dir(struct file *filp, ch 181 ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos)
224 { 182 {
225 return -EISDIR; 183 return -EISDIR;
226 } 184 }
227 EXPORT_SYMBOL(generic_read_dir); <<
228 185
229 const struct file_operations simple_dir_operat 186 const struct file_operations simple_dir_operations = {
230 .open = dcache_dir_open, 187 .open = dcache_dir_open,
231 .release = dcache_dir_close, 188 .release = dcache_dir_close,
232 .llseek = dcache_dir_lseek, 189 .llseek = dcache_dir_lseek,
233 .read = generic_read_dir, 190 .read = generic_read_dir,
234 .iterate_shared = dcache_readdir, !! 191 .readdir = dcache_readdir,
235 .fsync = noop_fsync, !! 192 .fsync = simple_sync_file,
236 }; 193 };
237 EXPORT_SYMBOL(simple_dir_operations); <<
238 194
239 const struct inode_operations simple_dir_inode 195 const struct inode_operations simple_dir_inode_operations = {
240 .lookup = simple_lookup, 196 .lookup = simple_lookup,
241 }; 197 };
242 EXPORT_SYMBOL(simple_dir_inode_operations); <<
243 <<
244 /* 0 is '.', 1 is '..', so always start with o <<
245 enum { <<
246 DIR_OFFSET_MIN = 2, <<
247 }; <<
248 <<
249 static void offset_set(struct dentry *dentry, <<
250 { <<
251 dentry->d_fsdata = (void *)offset; <<
252 } <<
253 <<
254 static long dentry2offset(struct dentry *dentr <<
255 { <<
256 return (long)dentry->d_fsdata; <<
257 } <<
258 <<
259 static struct lock_class_key simple_offset_loc <<
260 <<
261 /** <<
262 * simple_offset_init - initialize an offset_c <<
263 * @octx: directory offset map to be initializ <<
264 * <<
265 */ <<
266 void simple_offset_init(struct offset_ctx *oct <<
267 { <<
268 mt_init_flags(&octx->mt, MT_FLAGS_ALLO <<
269 lockdep_set_class(&octx->mt.ma_lock, & <<
270 octx->next_offset = DIR_OFFSET_MIN; <<
271 } <<
272 <<
273 /** <<
274 * simple_offset_add - Add an entry to a direc <<
275 * @octx: directory offset ctx to be updated <<
276 * @dentry: new dentry being added <<
277 * <<
278 * Returns zero on success. @octx and the dent <<
279 * Otherwise, a negative errno value is return <<
280 */ <<
281 int simple_offset_add(struct offset_ctx *octx, <<
282 { <<
283 unsigned long offset; <<
284 int ret; <<
285 <<
286 if (dentry2offset(dentry) != 0) <<
287 return -EBUSY; <<
288 <<
289 ret = mtree_alloc_cyclic(&octx->mt, &o <<
290 LONG_MAX, &oc <<
291 if (ret < 0) <<
292 return ret; <<
293 <<
294 offset_set(dentry, offset); <<
295 return 0; <<
296 } <<
297 <<
298 static int simple_offset_replace(struct offset <<
299 long offset) <<
300 { <<
301 int ret; <<
302 <<
303 ret = mtree_store(&octx->mt, offset, d <<
304 if (ret) <<
305 return ret; <<
306 offset_set(dentry, offset); <<
307 return 0; <<
308 } <<
309 <<
310 /** <<
311 * simple_offset_remove - Remove an entry to a <<
312 * @octx: directory offset ctx to be updated <<
313 * @dentry: dentry being removed <<
314 * <<
315 */ <<
316 void simple_offset_remove(struct offset_ctx *o <<
317 { <<
318 long offset; <<
319 <<
320 offset = dentry2offset(dentry); <<
321 if (offset == 0) <<
322 return; <<
323 <<
324 mtree_erase(&octx->mt, offset); <<
325 offset_set(dentry, 0); <<
326 } <<
327 <<
328 /** <<
329 * simple_offset_empty - Check if a dentry can <<
330 * @dentry: dentry to be tested <<
331 * <<
332 * Returns 0 if @dentry is a non-empty directo <<
333 */ <<
334 int simple_offset_empty(struct dentry *dentry) <<
335 { <<
336 struct inode *inode = d_inode(dentry); <<
337 struct offset_ctx *octx; <<
338 struct dentry *child; <<
339 unsigned long index; <<
340 int ret = 1; <<
341 <<
342 if (!inode || !S_ISDIR(inode->i_mode)) <<
343 return ret; <<
344 <<
345 index = DIR_OFFSET_MIN; <<
346 octx = inode->i_op->get_offset_ctx(ino <<
347 mt_for_each(&octx->mt, child, index, L <<
348 spin_lock(&child->d_lock); <<
349 if (simple_positive(child)) { <<
350 spin_unlock(&child->d_ <<
351 ret = 0; <<
352 break; <<
353 } <<
354 spin_unlock(&child->d_lock); <<
355 } <<
356 <<
357 return ret; <<
358 } <<
359 <<
360 /** <<
361 * simple_offset_rename - handle directory off <<
362 * @old_dir: parent directory of source entry <<
363 * @old_dentry: dentry of source entry <<
364 * @new_dir: parent_directory of destination e <<
365 * @new_dentry: dentry of destination <<
366 * <<
367 * Caller provides appropriate serialization. <<
368 * <<
369 * User space expects the directory offset val <<
370 * (new) directory entry to be unchanged after <<
371 * <<
372 * Returns zero on success, a negative errno v <<
373 */ <<
374 int simple_offset_rename(struct inode *old_dir <<
375 struct inode *new_dir <<
376 { <<
377 struct offset_ctx *old_ctx = old_dir-> <<
378 struct offset_ctx *new_ctx = new_dir-> <<
379 long new_offset = dentry2offset(new_de <<
380 <<
381 simple_offset_remove(old_ctx, old_dent <<
382 <<
383 if (new_offset) { <<
384 offset_set(new_dentry, 0); <<
385 return simple_offset_replace(n <<
386 } <<
387 return simple_offset_add(new_ctx, old_ <<
388 } <<
389 <<
390 /** <<
391 * simple_offset_rename_exchange - exchange re <<
392 * @old_dir: parent of dentry being moved <<
393 * @old_dentry: dentry being moved <<
394 * @new_dir: destination parent <<
395 * @new_dentry: destination dentry <<
396 * <<
397 * This API preserves the directory offset val <<
398 * appropriate serialization. <<
399 * <<
400 * Returns zero on success. Otherwise a negati <<
401 * rename is rolled back. <<
402 */ <<
403 int simple_offset_rename_exchange(struct inode <<
404 struct dentr <<
405 struct inode <<
406 struct dentr <<
407 { <<
408 struct offset_ctx *old_ctx = old_dir-> <<
409 struct offset_ctx *new_ctx = new_dir-> <<
410 long old_index = dentry2offset(old_den <<
411 long new_index = dentry2offset(new_den <<
412 int ret; <<
413 <<
414 simple_offset_remove(old_ctx, old_dent <<
415 simple_offset_remove(new_ctx, new_dent <<
416 <<
417 ret = simple_offset_replace(new_ctx, o <<
418 if (ret) <<
419 goto out_restore; <<
420 <<
421 ret = simple_offset_replace(old_ctx, n <<
422 if (ret) { <<
423 simple_offset_remove(new_ctx, <<
424 goto out_restore; <<
425 } <<
426 <<
427 ret = simple_rename_exchange(old_dir, <<
428 if (ret) { <<
429 simple_offset_remove(new_ctx, <<
430 simple_offset_remove(old_ctx, <<
431 goto out_restore; <<
432 } <<
433 return 0; <<
434 <<
435 out_restore: <<
436 (void)simple_offset_replace(old_ctx, o <<
437 (void)simple_offset_replace(new_ctx, n <<
438 return ret; <<
439 } <<
440 <<
441 /** <<
442 * simple_offset_destroy - Release offset map <<
443 * @octx: directory offset ctx that is about t <<
444 * <<
445 * During fs teardown (eg. umount), a director <<
446 * contain entries. xa_destroy() cleans out an <<
447 */ <<
448 void simple_offset_destroy(struct offset_ctx * <<
449 { <<
450 mtree_destroy(&octx->mt); <<
451 } <<
452 <<
453 static int offset_dir_open(struct inode *inode <<
454 { <<
455 struct offset_ctx *ctx = inode->i_op-> <<
456 <<
457 file->private_data = (void *)ctx->next <<
458 return 0; <<
459 } <<
460 <<
461 /** <<
462 * offset_dir_llseek - Advance the read positi <<
463 * @file: an open directory whose position is <<
464 * @offset: a byte offset <<
465 * @whence: enumerator describing the starting <<
466 * <<
467 * SEEK_END, SEEK_DATA, and SEEK_HOLE are not <<
468 * <<
469 * Returns the updated read position if succes <<
470 * negative errno is returned and the read pos <<
471 */ <<
472 static loff_t offset_dir_llseek(struct file *f <<
473 { <<
474 struct inode *inode = file->f_inode; <<
475 struct offset_ctx *ctx = inode->i_op-> <<
476 <<
477 switch (whence) { <<
478 case SEEK_CUR: <<
479 offset += file->f_pos; <<
480 fallthrough; <<
481 case SEEK_SET: <<
482 if (offset >= 0) <<
483 break; <<
484 fallthrough; <<
485 default: <<
486 return -EINVAL; <<
487 } <<
488 <<
489 /* In this case, ->private_data is pro <<
490 if (!offset) <<
491 file->private_data = (void *)c <<
492 return vfs_setpos(file, offset, LONG_M <<
493 } <<
494 <<
495 static struct dentry *offset_find_next(struct <<
496 { <<
497 MA_STATE(mas, &octx->mt, offset, offse <<
498 struct dentry *child, *found = NULL; <<
499 <<
500 rcu_read_lock(); <<
501 child = mas_find(&mas, LONG_MAX); <<
502 if (!child) <<
503 goto out; <<
504 spin_lock(&child->d_lock); <<
505 if (simple_positive(child)) <<
506 found = dget_dlock(child); <<
507 spin_unlock(&child->d_lock); <<
508 out: <<
509 rcu_read_unlock(); <<
510 return found; <<
511 } <<
512 <<
513 static bool offset_dir_emit(struct dir_context <<
514 { <<
515 struct inode *inode = d_inode(dentry); <<
516 long offset = dentry2offset(dentry); <<
517 <<
518 return ctx->actor(ctx, dentry->d_name. <<
519 inode->i_ino, fs_umo <<
520 } <<
521 <<
522 static void offset_iterate_dir(struct inode *i <<
523 { <<
524 struct offset_ctx *octx = inode->i_op- <<
525 struct dentry *dentry; <<
526 <<
527 while (true) { <<
528 dentry = offset_find_next(octx <<
529 if (!dentry) <<
530 return; <<
531 <<
532 if (dentry2offset(dentry) >= l <<
533 dput(dentry); <<
534 return; <<
535 } <<
536 <<
537 if (!offset_dir_emit(ctx, dent <<
538 dput(dentry); <<
539 return; <<
540 } <<
541 <<
542 ctx->pos = dentry2offset(dentr <<
543 dput(dentry); <<
544 } <<
545 } <<
546 <<
547 /** <<
548 * offset_readdir - Emit entries starting at o <<
549 * @file: an open directory to iterate over <<
550 * @ctx: directory iteration context <<
551 * <<
552 * Caller must hold @file's i_rwsem to prevent <<
553 * entries during this call. <<
554 * <<
555 * On entry, @ctx->pos contains an offset that <<
556 * to be read from the directory. <<
557 * <<
558 * The operation continues until there are no <<
559 * until the ctx->actor indicates there is no <<
560 * output buffer. <<
561 * <<
562 * On return, @ctx->pos contains an offset tha <<
563 * in this directory when offset_readdir() is <<
564 * <<
565 * Return values: <<
566 * %0 - Complete <<
567 */ <<
568 static int offset_readdir(struct file *file, s <<
569 { <<
570 struct dentry *dir = file->f_path.dent <<
571 long last_index = (long)file->private_ <<
572 <<
573 lockdep_assert_held(&d_inode(dir)->i_r <<
574 <<
575 if (!dir_emit_dots(file, ctx)) <<
576 return 0; <<
577 <<
578 offset_iterate_dir(d_inode(dir), ctx, <<
579 return 0; <<
580 } <<
581 <<
582 const struct file_operations simple_offset_dir <<
583 .open = offset_dir_open, <<
584 .llseek = offset_dir_llseek, <<
585 .iterate_shared = offset_readdir, <<
586 .read = generic_read_dir, <<
587 .fsync = noop_fsync, <<
588 }; <<
589 <<
590 static struct dentry *find_next_child(struct d <<
591 { <<
592 struct dentry *child = NULL, *d; <<
593 <<
594 spin_lock(&parent->d_lock); <<
595 d = prev ? d_next_sibling(prev) : d_fi <<
596 hlist_for_each_entry_from(d, d_sib) { <<
597 if (simple_positive(d)) { <<
598 spin_lock_nested(&d->d <<
599 if (simple_positive(d) <<
600 child = dget_d <<
601 spin_unlock(&d->d_lock <<
602 if (likely(child)) <<
603 break; <<
604 } <<
605 } <<
606 spin_unlock(&parent->d_lock); <<
607 dput(prev); <<
608 return child; <<
609 } <<
610 <<
611 void simple_recursive_removal(struct dentry *d <<
612 void (*callback) <<
613 { <<
614 struct dentry *this = dget(dentry); <<
615 while (true) { <<
616 struct dentry *victim = NULL, <<
617 struct inode *inode = this->d_ <<
618 <<
619 inode_lock(inode); <<
620 if (d_is_dir(this)) <<
621 inode->i_flags |= S_DE <<
622 while ((child = find_next_chil <<
623 // kill and ascend <<
624 // update metadata whi <<
625 inode_set_ctime_curren <<
626 clear_nlink(inode); <<
627 inode_unlock(inode); <<
628 victim = this; <<
629 this = this->d_parent; <<
630 inode = this->d_inode; <<
631 inode_lock(inode); <<
632 if (simple_positive(vi <<
633 d_invalidate(v <<
634 if (d_is_dir(v <<
635 fsnoti <<
636 else <<
637 fsnoti <<
638 if (callback) <<
639 callba <<
640 dput(victim); <<
641 } <<
642 if (victim == dentry) <<
643 inode_set_mtim <<
644 <<
645 if (d_is_dir(d <<
646 drop_n <<
647 inode_unlock(i <<
648 dput(dentry); <<
649 return; <<
650 } <<
651 } <<
652 inode_unlock(inode); <<
653 this = child; <<
654 } <<
655 } <<
656 EXPORT_SYMBOL(simple_recursive_removal); <<
657 198
658 static const struct super_operations simple_su 199 static const struct super_operations simple_super_operations = {
659 .statfs = simple_statfs, 200 .statfs = simple_statfs,
660 }; 201 };
661 202
662 static int pseudo_fs_fill_super(struct super_b !! 203 /*
>> 204 * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that
>> 205 * will never be mountable)
>> 206 */
>> 207 int get_sb_pseudo(struct file_system_type *fs_type, char *name,
>> 208 const struct super_operations *ops, unsigned long magic,
>> 209 struct vfsmount *mnt)
663 { 210 {
664 struct pseudo_fs_context *ctx = fc->fs !! 211 struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL);
>> 212 struct dentry *dentry;
665 struct inode *root; 213 struct inode *root;
>> 214 struct qstr d_name = {.name = name, .len = strlen(name)};
>> 215
>> 216 if (IS_ERR(s))
>> 217 return PTR_ERR(s);
666 218
>> 219 s->s_flags = MS_NOUSER;
667 s->s_maxbytes = MAX_LFS_FILESIZE; 220 s->s_maxbytes = MAX_LFS_FILESIZE;
668 s->s_blocksize = PAGE_SIZE; 221 s->s_blocksize = PAGE_SIZE;
669 s->s_blocksize_bits = PAGE_SHIFT; 222 s->s_blocksize_bits = PAGE_SHIFT;
670 s->s_magic = ctx->magic; !! 223 s->s_magic = magic;
671 s->s_op = ctx->ops ?: &simple_super_op !! 224 s->s_op = ops ? ops : &simple_super_operations;
672 s->s_xattr = ctx->xattr; <<
673 s->s_time_gran = 1; 225 s->s_time_gran = 1;
674 root = new_inode(s); 226 root = new_inode(s);
675 if (!root) 227 if (!root)
676 return -ENOMEM; !! 228 goto Enomem;
677 <<
678 /* 229 /*
679 * since this is the first inode, make 230 * since this is the first inode, make it number 1. New inodes created
680 * after this must take care not to co 231 * after this must take care not to collide with it (by passing
681 * max_reserved of 1 to iunique). 232 * max_reserved of 1 to iunique).
682 */ 233 */
683 root->i_ino = 1; 234 root->i_ino = 1;
684 root->i_mode = S_IFDIR | S_IRUSR | S_I 235 root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR;
685 simple_inode_init_ts(root); !! 236 root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME;
686 s->s_root = d_make_root(root); !! 237 dentry = d_alloc(NULL, &d_name);
687 if (!s->s_root) !! 238 if (!dentry) {
688 return -ENOMEM; !! 239 iput(root);
689 s->s_d_op = ctx->dops; !! 240 goto Enomem;
690 return 0; <<
691 } <<
692 <<
693 static int pseudo_fs_get_tree(struct fs_contex <<
694 { <<
695 return get_tree_nodev(fc, pseudo_fs_fi <<
696 } <<
697 <<
698 static void pseudo_fs_free(struct fs_context * <<
699 { <<
700 kfree(fc->fs_private); <<
701 } <<
702 <<
703 static const struct fs_context_operations pseu <<
704 .free = pseudo_fs_free, <<
705 .get_tree = pseudo_fs_get_tree, <<
706 }; <<
707 <<
708 /* <<
709 * Common helper for pseudo-filesystems (sockf <<
710 * will never be mountable) <<
711 */ <<
712 struct pseudo_fs_context *init_pseudo(struct f <<
713 unsign <<
714 { <<
715 struct pseudo_fs_context *ctx; <<
716 <<
717 ctx = kzalloc(sizeof(struct pseudo_fs_ <<
718 if (likely(ctx)) { <<
719 ctx->magic = magic; <<
720 fc->fs_private = ctx; <<
721 fc->ops = &pseudo_fs_context_o <<
722 fc->sb_flags |= SB_NOUSER; <<
723 fc->global = true; <<
724 } 241 }
725 return ctx; !! 242 dentry->d_sb = s;
726 } !! 243 dentry->d_parent = dentry;
727 EXPORT_SYMBOL(init_pseudo); !! 244 d_instantiate(dentry, root);
728 !! 245 s->s_root = dentry;
729 int simple_open(struct inode *inode, struct fi !! 246 s->s_flags |= MS_ACTIVE;
730 { !! 247 simple_set_mnt(mnt, s);
731 if (inode->i_private) <<
732 file->private_data = inode->i_ <<
733 return 0; 248 return 0;
>> 249
>> 250 Enomem:
>> 251 deactivate_locked_super(s);
>> 252 return -ENOMEM;
734 } 253 }
735 EXPORT_SYMBOL(simple_open); <<
736 254
737 int simple_link(struct dentry *old_dentry, str 255 int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
738 { 256 {
739 struct inode *inode = d_inode(old_dent !! 257 struct inode *inode = old_dentry->d_inode;
740 258
741 inode_set_mtime_to_ts(dir, !! 259 inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
742 inode_set_ctime_ <<
743 inc_nlink(inode); 260 inc_nlink(inode);
744 ihold(inode); !! 261 atomic_inc(&inode->i_count);
745 dget(dentry); 262 dget(dentry);
746 d_instantiate(dentry, inode); 263 d_instantiate(dentry, inode);
747 return 0; 264 return 0;
748 } 265 }
749 EXPORT_SYMBOL(simple_link); !! 266
>> 267 static inline int simple_positive(struct dentry *dentry)
>> 268 {
>> 269 return dentry->d_inode && !d_unhashed(dentry);
>> 270 }
750 271
751 int simple_empty(struct dentry *dentry) 272 int simple_empty(struct dentry *dentry)
752 { 273 {
753 struct dentry *child; 274 struct dentry *child;
754 int ret = 0; 275 int ret = 0;
755 276
756 spin_lock(&dentry->d_lock); !! 277 spin_lock(&dcache_lock);
757 hlist_for_each_entry(child, &dentry->d !! 278 list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
758 spin_lock_nested(&child->d_loc !! 279 if (simple_positive(child))
759 if (simple_positive(child)) { <<
760 spin_unlock(&child->d_ <<
761 goto out; 280 goto out;
762 } <<
763 spin_unlock(&child->d_lock); <<
764 } <<
765 ret = 1; 281 ret = 1;
766 out: 282 out:
767 spin_unlock(&dentry->d_lock); !! 283 spin_unlock(&dcache_lock);
768 return ret; 284 return ret;
769 } 285 }
770 EXPORT_SYMBOL(simple_empty); <<
771 286
772 int simple_unlink(struct inode *dir, struct de 287 int simple_unlink(struct inode *dir, struct dentry *dentry)
773 { 288 {
774 struct inode *inode = d_inode(dentry); !! 289 struct inode *inode = dentry->d_inode;
775 290
776 inode_set_mtime_to_ts(dir, !! 291 inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
777 inode_set_ctime_ <<
778 drop_nlink(inode); 292 drop_nlink(inode);
779 dput(dentry); 293 dput(dentry);
780 return 0; 294 return 0;
781 } 295 }
782 EXPORT_SYMBOL(simple_unlink); <<
783 296
784 int simple_rmdir(struct inode *dir, struct den 297 int simple_rmdir(struct inode *dir, struct dentry *dentry)
785 { 298 {
786 if (!simple_empty(dentry)) 299 if (!simple_empty(dentry))
787 return -ENOTEMPTY; 300 return -ENOTEMPTY;
788 301
789 drop_nlink(d_inode(dentry)); !! 302 drop_nlink(dentry->d_inode);
790 simple_unlink(dir, dentry); 303 simple_unlink(dir, dentry);
791 drop_nlink(dir); 304 drop_nlink(dir);
792 return 0; 305 return 0;
793 } 306 }
794 EXPORT_SYMBOL(simple_rmdir); <<
795 307
796 /** !! 308 int simple_rename(struct inode *old_dir, struct dentry *old_dentry,
797 * simple_rename_timestamp - update the variou !! 309 struct inode *new_dir, struct dentry *new_dentry)
798 * @old_dir: old parent directory <<
799 * @old_dentry: dentry that is being renamed <<
800 * @new_dir: new parent directory <<
801 * @new_dentry: target for rename <<
802 * <<
803 * POSIX mandates that the old and new parent <<
804 * mtime updated, and that inodes of @old_dent <<
805 * their ctime updated. <<
806 */ <<
807 void simple_rename_timestamp(struct inode *old <<
808 struct inode *new <<
809 { 310 {
810 struct inode *newino = d_inode(new_den !! 311 struct inode *inode = old_dentry->d_inode;
811 !! 312 int they_are_dirs = S_ISDIR(old_dentry->d_inode->i_mode);
812 inode_set_mtime_to_ts(old_dir, inode_s <<
813 if (new_dir != old_dir) <<
814 inode_set_mtime_to_ts(new_dir, <<
815 inode_se <<
816 inode_set_ctime_current(d_inode(old_de <<
817 if (newino) <<
818 inode_set_ctime_current(newino <<
819 } <<
820 EXPORT_SYMBOL_GPL(simple_rename_timestamp); <<
821 <<
822 int simple_rename_exchange(struct inode *old_d <<
823 struct inode *new_d <<
824 { <<
825 bool old_is_dir = d_is_dir(old_dentry) <<
826 bool new_is_dir = d_is_dir(new_dentry) <<
827 <<
828 if (old_dir != new_dir && old_is_dir ! <<
829 if (old_is_dir) { <<
830 drop_nlink(old_dir); <<
831 inc_nlink(new_dir); <<
832 } else { <<
833 drop_nlink(new_dir); <<
834 inc_nlink(old_dir); <<
835 } <<
836 } <<
837 simple_rename_timestamp(old_dir, old_d <<
838 return 0; <<
839 } <<
840 EXPORT_SYMBOL_GPL(simple_rename_exchange); <<
841 <<
842 int simple_rename(struct mnt_idmap *idmap, str <<
843 struct dentry *old_dentry, s <<
844 struct dentry *new_dentry, u <<
845 { <<
846 int they_are_dirs = d_is_dir(old_dentr <<
847 <<
848 if (flags & ~(RENAME_NOREPLACE | RENAM <<
849 return -EINVAL; <<
850 <<
851 if (flags & RENAME_EXCHANGE) <<
852 return simple_rename_exchange( <<
853 313
854 if (!simple_empty(new_dentry)) 314 if (!simple_empty(new_dentry))
855 return -ENOTEMPTY; 315 return -ENOTEMPTY;
856 316
857 if (d_really_is_positive(new_dentry)) !! 317 if (new_dentry->d_inode) {
858 simple_unlink(new_dir, new_den 318 simple_unlink(new_dir, new_dentry);
859 if (they_are_dirs) { !! 319 if (they_are_dirs)
860 drop_nlink(d_inode(new <<
861 drop_nlink(old_dir); 320 drop_nlink(old_dir);
862 } <<
863 } else if (they_are_dirs) { 321 } else if (they_are_dirs) {
864 drop_nlink(old_dir); 322 drop_nlink(old_dir);
865 inc_nlink(new_dir); 323 inc_nlink(new_dir);
866 } 324 }
867 325
868 simple_rename_timestamp(old_dir, old_d !! 326 old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime =
>> 327 new_dir->i_mtime = inode->i_ctime = CURRENT_TIME;
>> 328
869 return 0; 329 return 0;
870 } 330 }
871 EXPORT_SYMBOL(simple_rename); <<
872 331
873 /** !! 332 int simple_readpage(struct file *file, struct page *page)
874 * simple_setattr - setattr for simple filesys <<
875 * @idmap: idmap of the target mount <<
876 * @dentry: dentry <<
877 * @iattr: iattr structure <<
878 * <<
879 * Returns 0 on success, -error on failure. <<
880 * <<
881 * simple_setattr is a simple ->setattr implem <<
882 * implementation of size changes. <<
883 * <<
884 * It can either be used for in-memory filesys <<
885 * on simple regular filesystems. Anything th <<
886 * or wire state on size changes needs its own <<
887 */ <<
888 int simple_setattr(struct mnt_idmap *idmap, st <<
889 struct iattr *iattr) <<
890 { 333 {
891 struct inode *inode = d_inode(dentry); !! 334 clear_highpage(page);
892 int error; !! 335 flush_dcache_page(page);
893 !! 336 SetPageUptodate(page);
894 error = setattr_prepare(idmap, dentry, !! 337 unlock_page(page);
895 if (error) <<
896 return error; <<
897 <<
898 if (iattr->ia_valid & ATTR_SIZE) <<
899 truncate_setsize(inode, iattr- <<
900 setattr_copy(idmap, inode, iattr); <<
901 mark_inode_dirty(inode); <<
902 return 0; 338 return 0;
903 } 339 }
904 EXPORT_SYMBOL(simple_setattr); <<
905 340
906 static int simple_read_folio(struct file *file !! 341 int simple_prepare_write(struct file *file, struct page *page,
>> 342 unsigned from, unsigned to)
907 { 343 {
908 folio_zero_range(folio, 0, folio_size( !! 344 if (!PageUptodate(page)) {
909 flush_dcache_folio(folio); !! 345 if (to - from != PAGE_CACHE_SIZE)
910 folio_mark_uptodate(folio); !! 346 zero_user_segments(page,
911 folio_unlock(folio); !! 347 0, from,
>> 348 to, PAGE_CACHE_SIZE);
>> 349 }
912 return 0; 350 return 0;
913 } 351 }
914 352
915 int simple_write_begin(struct file *file, stru 353 int simple_write_begin(struct file *file, struct address_space *mapping,
916 loff_t pos, unsigned l !! 354 loff_t pos, unsigned len, unsigned flags,
917 struct folio **foliop, !! 355 struct page **pagep, void **fsdata)
918 { 356 {
919 struct folio *folio; !! 357 struct page *page;
>> 358 pgoff_t index;
>> 359 unsigned from;
920 360
921 folio = __filemap_get_folio(mapping, p !! 361 index = pos >> PAGE_CACHE_SHIFT;
922 mapping_gfp_mask(mappi !! 362 from = pos & (PAGE_CACHE_SIZE - 1);
923 if (IS_ERR(folio)) <<
924 return PTR_ERR(folio); <<
925 363
926 *foliop = folio; !! 364 page = grab_cache_page_write_begin(mapping, index, flags);
>> 365 if (!page)
>> 366 return -ENOMEM;
927 367
928 if (!folio_test_uptodate(folio) && (le !! 368 *pagep = page;
929 size_t from = offset_in_folio( <<
930 369
931 folio_zero_segments(folio, 0, !! 370 return simple_prepare_write(file, page, from, from+len);
932 from + len, fo <<
933 } <<
934 return 0; <<
935 } 371 }
936 EXPORT_SYMBOL(simple_write_begin); <<
937 372
938 /** !! 373 static int simple_commit_write(struct file *file, struct page *page,
939 * simple_write_end - .write_end helper for no !! 374 unsigned from, unsigned to)
940 * @file: See .write_end of address_space_oper <<
941 * @mapping: " <<
942 * @pos: " <<
943 * @len: " <<
944 * @copied: " <<
945 * @folio: " <<
946 * @fsdata: " <<
947 * <<
948 * simple_write_end does the minimum needed fo <<
949 * writing is done. It has the same API signat <<
950 * address_space_operations vector. So it can <<
951 * FSes that don't need any other processing. <<
952 * Block based filesystems should use generic_ <<
953 * NOTE: Even though i_size might get updated <<
954 * is not called, so a filesystem that actuall <<
955 * should extend on what's done here with a ca <<
956 * case that i_size has changed. <<
957 * <<
958 * Use *ONLY* with simple_read_folio() <<
959 */ <<
960 static int simple_write_end(struct file *file, <<
961 loff_t pos, unsigned l <<
962 struct folio *folio, v <<
963 { 375 {
964 struct inode *inode = folio->mapping-> !! 376 struct inode *inode = page->mapping->host;
965 loff_t last_pos = pos + copied; !! 377 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
966 378
967 /* zero the stale part of the folio if !! 379 if (!PageUptodate(page))
968 if (!folio_test_uptodate(folio)) { !! 380 SetPageUptodate(page);
969 if (copied < len) { <<
970 size_t from = offset_i <<
971 <<
972 folio_zero_range(folio <<
973 } <<
974 folio_mark_uptodate(folio); <<
975 } <<
976 /* 381 /*
977 * No need to use i_size_read() here, 382 * No need to use i_size_read() here, the i_size
978 * cannot change under us because we h 383 * cannot change under us because we hold the i_mutex.
979 */ 384 */
980 if (last_pos > inode->i_size) !! 385 if (pos > inode->i_size)
981 i_size_write(inode, last_pos); !! 386 i_size_write(inode, pos);
>> 387 set_page_dirty(page);
>> 388 return 0;
>> 389 }
>> 390
>> 391 int simple_write_end(struct file *file, struct address_space *mapping,
>> 392 loff_t pos, unsigned len, unsigned copied,
>> 393 struct page *page, void *fsdata)
>> 394 {
>> 395 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
>> 396
>> 397 /* zero the stale part of the page if we did a short copy */
>> 398 if (copied < len) {
>> 399 void *kaddr = kmap_atomic(page, KM_USER0);
>> 400 memset(kaddr + from + copied, 0, len - copied);
>> 401 flush_dcache_page(page);
>> 402 kunmap_atomic(kaddr, KM_USER0);
>> 403 }
982 404
983 folio_mark_dirty(folio); !! 405 simple_commit_write(file, page, from, from+copied);
984 folio_unlock(folio); !! 406
985 folio_put(folio); !! 407 unlock_page(page);
>> 408 page_cache_release(page);
986 409
987 return copied; 410 return copied;
988 } 411 }
989 412
990 /* 413 /*
991 * Provides ramfs-style behavior: data in the <<
992 */ <<
993 const struct address_space_operations ram_aops <<
994 .read_folio = simple_read_folio, <<
995 .write_begin = simple_write_begin, <<
996 .write_end = simple_write_end, <<
997 .dirty_folio = noop_dirty_folio, <<
998 }; <<
999 EXPORT_SYMBOL(ram_aops); <<
1000 <<
1001 /* <<
1002 * the inodes created here are not hashed. If 414 * the inodes created here are not hashed. If you use iunique to generate
1003 * unique inode values later for this filesys 415 * unique inode values later for this filesystem, then you must take care
1004 * to pass it an appropriate max_reserved val 416 * to pass it an appropriate max_reserved value to avoid collisions.
1005 */ 417 */
1006 int simple_fill_super(struct super_block *s, 418 int simple_fill_super(struct super_block *s, unsigned long magic,
1007 const struct tree_descr !! 419 struct tree_descr *files)
1008 { 420 {
1009 struct inode *inode; 421 struct inode *inode;
>> 422 struct dentry *root;
1010 struct dentry *dentry; 423 struct dentry *dentry;
1011 int i; 424 int i;
1012 425
1013 s->s_blocksize = PAGE_SIZE; !! 426 s->s_blocksize = PAGE_CACHE_SIZE;
1014 s->s_blocksize_bits = PAGE_SHIFT; !! 427 s->s_blocksize_bits = PAGE_CACHE_SHIFT;
1015 s->s_magic = magic; 428 s->s_magic = magic;
1016 s->s_op = &simple_super_operations; 429 s->s_op = &simple_super_operations;
1017 s->s_time_gran = 1; 430 s->s_time_gran = 1;
1018 431
1019 inode = new_inode(s); 432 inode = new_inode(s);
1020 if (!inode) 433 if (!inode)
1021 return -ENOMEM; 434 return -ENOMEM;
1022 /* 435 /*
1023 * because the root inode is 1, the f 436 * because the root inode is 1, the files array must not contain an
1024 * entry at index 1 437 * entry at index 1
1025 */ 438 */
1026 inode->i_ino = 1; 439 inode->i_ino = 1;
1027 inode->i_mode = S_IFDIR | 0755; 440 inode->i_mode = S_IFDIR | 0755;
1028 simple_inode_init_ts(inode); !! 441 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1029 inode->i_op = &simple_dir_inode_opera 442 inode->i_op = &simple_dir_inode_operations;
1030 inode->i_fop = &simple_dir_operations 443 inode->i_fop = &simple_dir_operations;
1031 set_nlink(inode, 2); !! 444 inode->i_nlink = 2;
1032 s->s_root = d_make_root(inode); !! 445 root = d_alloc_root(inode);
1033 if (!s->s_root) !! 446 if (!root) {
>> 447 iput(inode);
1034 return -ENOMEM; 448 return -ENOMEM;
>> 449 }
1035 for (i = 0; !files->name || files->na 450 for (i = 0; !files->name || files->name[0]; i++, files++) {
1036 if (!files->name) 451 if (!files->name)
1037 continue; 452 continue;
1038 453
1039 /* warn if it tries to confli 454 /* warn if it tries to conflict with the root inode */
1040 if (unlikely(i == 1)) 455 if (unlikely(i == 1))
1041 printk(KERN_WARNING " 456 printk(KERN_WARNING "%s: %s passed in a files array"
1042 "with an inde 457 "with an index of 1!\n", __func__,
1043 s->s_type->na 458 s->s_type->name);
1044 459
1045 dentry = d_alloc_name(s->s_ro !! 460 dentry = d_alloc_name(root, files->name);
1046 if (!dentry) 461 if (!dentry)
1047 return -ENOMEM; !! 462 goto out;
1048 inode = new_inode(s); 463 inode = new_inode(s);
1049 if (!inode) { !! 464 if (!inode)
1050 dput(dentry); !! 465 goto out;
1051 return -ENOMEM; <<
1052 } <<
1053 inode->i_mode = S_IFREG | fil 466 inode->i_mode = S_IFREG | files->mode;
1054 simple_inode_init_ts(inode); !! 467 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1055 inode->i_fop = files->ops; 468 inode->i_fop = files->ops;
1056 inode->i_ino = i; 469 inode->i_ino = i;
1057 d_add(dentry, inode); 470 d_add(dentry, inode);
1058 } 471 }
>> 472 s->s_root = root;
1059 return 0; 473 return 0;
>> 474 out:
>> 475 d_genocide(root);
>> 476 dput(root);
>> 477 return -ENOMEM;
1060 } 478 }
1061 EXPORT_SYMBOL(simple_fill_super); <<
1062 479
1063 static DEFINE_SPINLOCK(pin_fs_lock); 480 static DEFINE_SPINLOCK(pin_fs_lock);
1064 481
1065 int simple_pin_fs(struct file_system_type *ty 482 int simple_pin_fs(struct file_system_type *type, struct vfsmount **mount, int *count)
1066 { 483 {
1067 struct vfsmount *mnt = NULL; 484 struct vfsmount *mnt = NULL;
1068 spin_lock(&pin_fs_lock); 485 spin_lock(&pin_fs_lock);
1069 if (unlikely(!*mount)) { 486 if (unlikely(!*mount)) {
1070 spin_unlock(&pin_fs_lock); 487 spin_unlock(&pin_fs_lock);
1071 mnt = vfs_kern_mount(type, SB !! 488 mnt = vfs_kern_mount(type, 0, type->name, NULL);
1072 if (IS_ERR(mnt)) 489 if (IS_ERR(mnt))
1073 return PTR_ERR(mnt); 490 return PTR_ERR(mnt);
1074 spin_lock(&pin_fs_lock); 491 spin_lock(&pin_fs_lock);
1075 if (!*mount) 492 if (!*mount)
1076 *mount = mnt; 493 *mount = mnt;
1077 } 494 }
1078 mntget(*mount); 495 mntget(*mount);
1079 ++*count; 496 ++*count;
1080 spin_unlock(&pin_fs_lock); 497 spin_unlock(&pin_fs_lock);
1081 mntput(mnt); 498 mntput(mnt);
1082 return 0; 499 return 0;
1083 } 500 }
1084 EXPORT_SYMBOL(simple_pin_fs); <<
1085 501
1086 void simple_release_fs(struct vfsmount **moun 502 void simple_release_fs(struct vfsmount **mount, int *count)
1087 { 503 {
1088 struct vfsmount *mnt; 504 struct vfsmount *mnt;
1089 spin_lock(&pin_fs_lock); 505 spin_lock(&pin_fs_lock);
1090 mnt = *mount; 506 mnt = *mount;
1091 if (!--*count) 507 if (!--*count)
1092 *mount = NULL; 508 *mount = NULL;
1093 spin_unlock(&pin_fs_lock); 509 spin_unlock(&pin_fs_lock);
1094 mntput(mnt); 510 mntput(mnt);
1095 } 511 }
1096 EXPORT_SYMBOL(simple_release_fs); <<
1097 512
1098 /** 513 /**
1099 * simple_read_from_buffer - copy data from t 514 * simple_read_from_buffer - copy data from the buffer to user space
1100 * @to: the user space buffer to read to 515 * @to: the user space buffer to read to
1101 * @count: the maximum number of bytes to rea 516 * @count: the maximum number of bytes to read
1102 * @ppos: the current position in the buffer 517 * @ppos: the current position in the buffer
1103 * @from: the buffer to read from 518 * @from: the buffer to read from
1104 * @available: the size of the buffer 519 * @available: the size of the buffer
1105 * 520 *
1106 * The simple_read_from_buffer() function rea 521 * The simple_read_from_buffer() function reads up to @count bytes from the
1107 * buffer @from at offset @ppos into the user 522 * buffer @from at offset @ppos into the user space address starting at @to.
1108 * 523 *
1109 * On success, the number of bytes read is re 524 * On success, the number of bytes read is returned and the offset @ppos is
1110 * advanced by this number, or negative value 525 * advanced by this number, or negative value is returned on error.
1111 **/ 526 **/
1112 ssize_t simple_read_from_buffer(void __user * 527 ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
1113 const void *f 528 const void *from, size_t available)
1114 { 529 {
1115 loff_t pos = *ppos; 530 loff_t pos = *ppos;
1116 size_t ret; 531 size_t ret;
1117 532
1118 if (pos < 0) 533 if (pos < 0)
1119 return -EINVAL; 534 return -EINVAL;
1120 if (pos >= available || !count) 535 if (pos >= available || !count)
1121 return 0; 536 return 0;
1122 if (count > available - pos) 537 if (count > available - pos)
1123 count = available - pos; 538 count = available - pos;
1124 ret = copy_to_user(to, from + pos, co 539 ret = copy_to_user(to, from + pos, count);
1125 if (ret == count) 540 if (ret == count)
1126 return -EFAULT; 541 return -EFAULT;
1127 count -= ret; 542 count -= ret;
1128 *ppos = pos + count; 543 *ppos = pos + count;
1129 return count; 544 return count;
1130 } 545 }
1131 EXPORT_SYMBOL(simple_read_from_buffer); <<
1132 <<
1133 /** <<
1134 * simple_write_to_buffer - copy data from us <<
1135 * @to: the buffer to write to <<
1136 * @available: the size of the buffer <<
1137 * @ppos: the current position in the buffer <<
1138 * @from: the user space buffer to read from <<
1139 * @count: the maximum number of bytes to rea <<
1140 * <<
1141 * The simple_write_to_buffer() function read <<
1142 * space address starting at @from into the b <<
1143 * <<
1144 * On success, the number of bytes written is <<
1145 * advanced by this number, or negative value <<
1146 **/ <<
1147 ssize_t simple_write_to_buffer(void *to, size <<
1148 const void __user *from, size <<
1149 { <<
1150 loff_t pos = *ppos; <<
1151 size_t res; <<
1152 <<
1153 if (pos < 0) <<
1154 return -EINVAL; <<
1155 if (pos >= available || !count) <<
1156 return 0; <<
1157 if (count > available - pos) <<
1158 count = available - pos; <<
1159 res = copy_from_user(to + pos, from, <<
1160 if (res == count) <<
1161 return -EFAULT; <<
1162 count -= res; <<
1163 *ppos = pos + count; <<
1164 return count; <<
1165 } <<
1166 EXPORT_SYMBOL(simple_write_to_buffer); <<
1167 546
1168 /** 547 /**
1169 * memory_read_from_buffer - copy data from t 548 * memory_read_from_buffer - copy data from the buffer
1170 * @to: the kernel space buffer to read to 549 * @to: the kernel space buffer to read to
1171 * @count: the maximum number of bytes to rea 550 * @count: the maximum number of bytes to read
1172 * @ppos: the current position in the buffer 551 * @ppos: the current position in the buffer
1173 * @from: the buffer to read from 552 * @from: the buffer to read from
1174 * @available: the size of the buffer 553 * @available: the size of the buffer
1175 * 554 *
1176 * The memory_read_from_buffer() function rea 555 * The memory_read_from_buffer() function reads up to @count bytes from the
1177 * buffer @from at offset @ppos into the kern 556 * buffer @from at offset @ppos into the kernel space address starting at @to.
1178 * 557 *
1179 * On success, the number of bytes read is re 558 * On success, the number of bytes read is returned and the offset @ppos is
1180 * advanced by this number, or negative value 559 * advanced by this number, or negative value is returned on error.
1181 **/ 560 **/
1182 ssize_t memory_read_from_buffer(void *to, siz 561 ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
1183 const void *f 562 const void *from, size_t available)
1184 { 563 {
1185 loff_t pos = *ppos; 564 loff_t pos = *ppos;
1186 565
1187 if (pos < 0) 566 if (pos < 0)
1188 return -EINVAL; 567 return -EINVAL;
1189 if (pos >= available) 568 if (pos >= available)
1190 return 0; 569 return 0;
1191 if (count > available - pos) 570 if (count > available - pos)
1192 count = available - pos; 571 count = available - pos;
1193 memcpy(to, from + pos, count); 572 memcpy(to, from + pos, count);
1194 *ppos = pos + count; 573 *ppos = pos + count;
1195 574
1196 return count; 575 return count;
1197 } 576 }
1198 EXPORT_SYMBOL(memory_read_from_buffer); <<
1199 577
1200 /* 578 /*
1201 * Transaction based IO. 579 * Transaction based IO.
1202 * The file expects a single write which trig 580 * The file expects a single write which triggers the transaction, and then
1203 * possibly a read which collects the result 581 * possibly a read which collects the result - which is stored in a
1204 * file-local buffer. 582 * file-local buffer.
1205 */ 583 */
1206 584
1207 void simple_transaction_set(struct file *file 585 void simple_transaction_set(struct file *file, size_t n)
1208 { 586 {
1209 struct simple_transaction_argresp *ar 587 struct simple_transaction_argresp *ar = file->private_data;
1210 588
1211 BUG_ON(n > SIMPLE_TRANSACTION_LIMIT); 589 BUG_ON(n > SIMPLE_TRANSACTION_LIMIT);
1212 590
1213 /* 591 /*
1214 * The barrier ensures that ar->size 592 * The barrier ensures that ar->size will really remain zero until
1215 * ar->data is ready for reading. 593 * ar->data is ready for reading.
1216 */ 594 */
1217 smp_mb(); 595 smp_mb();
1218 ar->size = n; 596 ar->size = n;
1219 } 597 }
1220 EXPORT_SYMBOL(simple_transaction_set); <<
1221 598
1222 char *simple_transaction_get(struct file *fil 599 char *simple_transaction_get(struct file *file, const char __user *buf, size_t size)
1223 { 600 {
1224 struct simple_transaction_argresp *ar 601 struct simple_transaction_argresp *ar;
1225 static DEFINE_SPINLOCK(simple_transac 602 static DEFINE_SPINLOCK(simple_transaction_lock);
1226 603
1227 if (size > SIMPLE_TRANSACTION_LIMIT - 604 if (size > SIMPLE_TRANSACTION_LIMIT - 1)
1228 return ERR_PTR(-EFBIG); 605 return ERR_PTR(-EFBIG);
1229 606
1230 ar = (struct simple_transaction_argre 607 ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL);
1231 if (!ar) 608 if (!ar)
1232 return ERR_PTR(-ENOMEM); 609 return ERR_PTR(-ENOMEM);
1233 610
1234 spin_lock(&simple_transaction_lock); 611 spin_lock(&simple_transaction_lock);
1235 612
1236 /* only one write allowed per open */ 613 /* only one write allowed per open */
1237 if (file->private_data) { 614 if (file->private_data) {
1238 spin_unlock(&simple_transacti 615 spin_unlock(&simple_transaction_lock);
1239 free_page((unsigned long)ar); 616 free_page((unsigned long)ar);
1240 return ERR_PTR(-EBUSY); 617 return ERR_PTR(-EBUSY);
1241 } 618 }
1242 619
1243 file->private_data = ar; 620 file->private_data = ar;
1244 621
1245 spin_unlock(&simple_transaction_lock) 622 spin_unlock(&simple_transaction_lock);
1246 623
1247 if (copy_from_user(ar->data, buf, siz 624 if (copy_from_user(ar->data, buf, size))
1248 return ERR_PTR(-EFAULT); 625 return ERR_PTR(-EFAULT);
1249 626
1250 return ar->data; 627 return ar->data;
1251 } 628 }
1252 EXPORT_SYMBOL(simple_transaction_get); <<
1253 629
1254 ssize_t simple_transaction_read(struct file * 630 ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
1255 { 631 {
1256 struct simple_transaction_argresp *ar 632 struct simple_transaction_argresp *ar = file->private_data;
1257 633
1258 if (!ar) 634 if (!ar)
1259 return 0; 635 return 0;
1260 return simple_read_from_buffer(buf, s 636 return simple_read_from_buffer(buf, size, pos, ar->data, ar->size);
1261 } 637 }
1262 EXPORT_SYMBOL(simple_transaction_read); <<
1263 638
1264 int simple_transaction_release(struct inode * 639 int simple_transaction_release(struct inode *inode, struct file *file)
1265 { 640 {
1266 free_page((unsigned long)file->privat 641 free_page((unsigned long)file->private_data);
1267 return 0; 642 return 0;
1268 } 643 }
1269 EXPORT_SYMBOL(simple_transaction_release); <<
1270 644
1271 /* Simple attribute files */ 645 /* Simple attribute files */
1272 646
1273 struct simple_attr { 647 struct simple_attr {
1274 int (*get)(void *, u64 *); 648 int (*get)(void *, u64 *);
1275 int (*set)(void *, u64); 649 int (*set)(void *, u64);
1276 char get_buf[24]; /* enough to 650 char get_buf[24]; /* enough to store a u64 and "\n\0" */
1277 char set_buf[24]; 651 char set_buf[24];
1278 void *data; 652 void *data;
1279 const char *fmt; /* format for 653 const char *fmt; /* format for read operation */
1280 struct mutex mutex; /* protects a 654 struct mutex mutex; /* protects access to these buffers */
1281 }; 655 };
1282 656
1283 /* simple_attr_open is called by an actual at 657 /* simple_attr_open is called by an actual attribute open file operation
1284 * to set the attribute specific access opera 658 * to set the attribute specific access operations. */
1285 int simple_attr_open(struct inode *inode, str 659 int simple_attr_open(struct inode *inode, struct file *file,
1286 int (*get)(void *, u64 * 660 int (*get)(void *, u64 *), int (*set)(void *, u64),
1287 const char *fmt) 661 const char *fmt)
1288 { 662 {
1289 struct simple_attr *attr; 663 struct simple_attr *attr;
1290 664
1291 attr = kzalloc(sizeof(*attr), GFP_KER !! 665 attr = kmalloc(sizeof(*attr), GFP_KERNEL);
1292 if (!attr) 666 if (!attr)
1293 return -ENOMEM; 667 return -ENOMEM;
1294 668
1295 attr->get = get; 669 attr->get = get;
1296 attr->set = set; 670 attr->set = set;
1297 attr->data = inode->i_private; 671 attr->data = inode->i_private;
1298 attr->fmt = fmt; 672 attr->fmt = fmt;
1299 mutex_init(&attr->mutex); 673 mutex_init(&attr->mutex);
1300 674
1301 file->private_data = attr; 675 file->private_data = attr;
1302 676
1303 return nonseekable_open(inode, file); 677 return nonseekable_open(inode, file);
1304 } 678 }
1305 EXPORT_SYMBOL_GPL(simple_attr_open); <<
1306 679
1307 int simple_attr_release(struct inode *inode, 680 int simple_attr_release(struct inode *inode, struct file *file)
1308 { 681 {
1309 kfree(file->private_data); 682 kfree(file->private_data);
1310 return 0; 683 return 0;
1311 } 684 }
1312 EXPORT_SYMBOL_GPL(simple_attr_release); /* GP <<
1313 685
1314 /* read from the buffer that is filled with t 686 /* read from the buffer that is filled with the get function */
1315 ssize_t simple_attr_read(struct file *file, c 687 ssize_t simple_attr_read(struct file *file, char __user *buf,
1316 size_t len, loff_t * 688 size_t len, loff_t *ppos)
1317 { 689 {
1318 struct simple_attr *attr; 690 struct simple_attr *attr;
1319 size_t size; 691 size_t size;
1320 ssize_t ret; 692 ssize_t ret;
1321 693
1322 attr = file->private_data; 694 attr = file->private_data;
1323 695
1324 if (!attr->get) 696 if (!attr->get)
1325 return -EACCES; 697 return -EACCES;
1326 698
1327 ret = mutex_lock_interruptible(&attr- 699 ret = mutex_lock_interruptible(&attr->mutex);
1328 if (ret) 700 if (ret)
1329 return ret; 701 return ret;
1330 702
1331 if (*ppos && attr->get_buf[0]) { !! 703 if (*ppos) { /* continued read */
1332 /* continued read */ <<
1333 size = strlen(attr->get_buf); 704 size = strlen(attr->get_buf);
1334 } else { !! 705 } else { /* first read */
1335 /* first read */ <<
1336 u64 val; 706 u64 val;
1337 ret = attr->get(attr->data, & 707 ret = attr->get(attr->data, &val);
1338 if (ret) 708 if (ret)
1339 goto out; 709 goto out;
1340 710
1341 size = scnprintf(attr->get_bu 711 size = scnprintf(attr->get_buf, sizeof(attr->get_buf),
1342 attr->fmt, ( 712 attr->fmt, (unsigned long long)val);
1343 } 713 }
1344 714
1345 ret = simple_read_from_buffer(buf, le 715 ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size);
1346 out: 716 out:
1347 mutex_unlock(&attr->mutex); 717 mutex_unlock(&attr->mutex);
1348 return ret; 718 return ret;
1349 } 719 }
1350 EXPORT_SYMBOL_GPL(simple_attr_read); <<
1351 720
1352 /* interpret the buffer as a number to call t 721 /* interpret the buffer as a number to call the set function with */
1353 static ssize_t simple_attr_write_xsigned(stru !! 722 ssize_t simple_attr_write(struct file *file, const char __user *buf,
1354 size_t len, loff_t !! 723 size_t len, loff_t *ppos)
1355 { 724 {
1356 struct simple_attr *attr; 725 struct simple_attr *attr;
1357 unsigned long long val; !! 726 u64 val;
1358 size_t size; 727 size_t size;
1359 ssize_t ret; 728 ssize_t ret;
1360 729
1361 attr = file->private_data; 730 attr = file->private_data;
1362 if (!attr->set) 731 if (!attr->set)
1363 return -EACCES; 732 return -EACCES;
1364 733
1365 ret = mutex_lock_interruptible(&attr- 734 ret = mutex_lock_interruptible(&attr->mutex);
1366 if (ret) 735 if (ret)
1367 return ret; 736 return ret;
1368 737
1369 ret = -EFAULT; 738 ret = -EFAULT;
1370 size = min(sizeof(attr->set_buf) - 1, 739 size = min(sizeof(attr->set_buf) - 1, len);
1371 if (copy_from_user(attr->set_buf, buf 740 if (copy_from_user(attr->set_buf, buf, size))
1372 goto out; 741 goto out;
1373 742
1374 attr->set_buf[size] = '\0'; 743 attr->set_buf[size] = '\0';
1375 if (is_signed) !! 744 val = simple_strtol(attr->set_buf, NULL, 0);
1376 ret = kstrtoll(attr->set_buf, <<
1377 else <<
1378 ret = kstrtoull(attr->set_buf <<
1379 if (ret) <<
1380 goto out; <<
1381 ret = attr->set(attr->data, val); 745 ret = attr->set(attr->data, val);
1382 if (ret == 0) 746 if (ret == 0)
1383 ret = len; /* on success, cla 747 ret = len; /* on success, claim we got the whole input */
1384 out: 748 out:
1385 mutex_unlock(&attr->mutex); 749 mutex_unlock(&attr->mutex);
1386 return ret; 750 return ret;
1387 } 751 }
1388 752
1389 ssize_t simple_attr_write(struct file *file, <<
1390 size_t len, loff_t <<
1391 { <<
1392 return simple_attr_write_xsigned(file <<
1393 } <<
1394 EXPORT_SYMBOL_GPL(simple_attr_write); <<
1395 <<
1396 ssize_t simple_attr_write_signed(struct file <<
1397 size_t len, loff_t <<
1398 { <<
1399 return simple_attr_write_xsigned(file <<
1400 } <<
1401 EXPORT_SYMBOL_GPL(simple_attr_write_signed); <<
1402 <<
1403 /** <<
1404 * generic_encode_ino32_fh - generic export_o <<
1405 * @inode: the object to encode <<
1406 * @fh: where to store the file handle f <<
1407 * @max_len: maximum length to store there (i <<
1408 * @parent: parent directory inode, if wante <<
1409 * <<
1410 * This generic encode_fh function assumes th <<
1411 * is suitable for locating an inode, and tha <<
1412 * can be used to check that it is still vali <<
1413 * filehandle fragment where export_decode_fh <<
1414 */ <<
1415 int generic_encode_ino32_fh(struct inode *ino <<
1416 struct inode *par <<
1417 { <<
1418 struct fid *fid = (void *)fh; <<
1419 int len = *max_len; <<
1420 int type = FILEID_INO32_GEN; <<
1421 <<
1422 if (parent && (len < 4)) { <<
1423 *max_len = 4; <<
1424 return FILEID_INVALID; <<
1425 } else if (len < 2) { <<
1426 *max_len = 2; <<
1427 return FILEID_INVALID; <<
1428 } <<
1429 <<
1430 len = 2; <<
1431 fid->i32.ino = inode->i_ino; <<
1432 fid->i32.gen = inode->i_generation; <<
1433 if (parent) { <<
1434 fid->i32.parent_ino = parent- <<
1435 fid->i32.parent_gen = parent- <<
1436 len = 4; <<
1437 type = FILEID_INO32_GEN_PAREN <<
1438 } <<
1439 *max_len = len; <<
1440 return type; <<
1441 } <<
1442 EXPORT_SYMBOL_GPL(generic_encode_ino32_fh); <<
1443 <<
1444 /** 753 /**
1445 * generic_fh_to_dentry - generic helper for 754 * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation
1446 * @sb: filesystem to do the file han 755 * @sb: filesystem to do the file handle conversion on
1447 * @fid: file handle to convert 756 * @fid: file handle to convert
1448 * @fh_len: length of the file handle in 757 * @fh_len: length of the file handle in bytes
1449 * @fh_type: type of file handle 758 * @fh_type: type of file handle
1450 * @get_inode: filesystem callback to retrie 759 * @get_inode: filesystem callback to retrieve inode
1451 * 760 *
1452 * This function decodes @fid as long as it h 761 * This function decodes @fid as long as it has one of the well-known
1453 * Linux filehandle types and calls @get_inod 762 * Linux filehandle types and calls @get_inode on it to retrieve the
1454 * inode for the object specified in the file 763 * inode for the object specified in the file handle.
1455 */ 764 */
1456 struct dentry *generic_fh_to_dentry(struct su 765 struct dentry *generic_fh_to_dentry(struct super_block *sb, struct fid *fid,
1457 int fh_len, int fh_type, stru 766 int fh_len, int fh_type, struct inode *(*get_inode)
1458 (struct super_block * 767 (struct super_block *sb, u64 ino, u32 gen))
1459 { 768 {
1460 struct inode *inode = NULL; 769 struct inode *inode = NULL;
1461 770
1462 if (fh_len < 2) 771 if (fh_len < 2)
1463 return NULL; 772 return NULL;
1464 773
1465 switch (fh_type) { 774 switch (fh_type) {
1466 case FILEID_INO32_GEN: 775 case FILEID_INO32_GEN:
1467 case FILEID_INO32_GEN_PARENT: 776 case FILEID_INO32_GEN_PARENT:
1468 inode = get_inode(sb, fid->i3 777 inode = get_inode(sb, fid->i32.ino, fid->i32.gen);
1469 break; 778 break;
1470 } 779 }
1471 780
1472 return d_obtain_alias(inode); 781 return d_obtain_alias(inode);
1473 } 782 }
1474 EXPORT_SYMBOL_GPL(generic_fh_to_dentry); 783 EXPORT_SYMBOL_GPL(generic_fh_to_dentry);
1475 784
1476 /** 785 /**
1477 * generic_fh_to_parent - generic helper for !! 786 * generic_fh_to_dentry - generic helper for the fh_to_parent export operation
1478 * @sb: filesystem to do the file han 787 * @sb: filesystem to do the file handle conversion on
1479 * @fid: file handle to convert 788 * @fid: file handle to convert
1480 * @fh_len: length of the file handle in 789 * @fh_len: length of the file handle in bytes
1481 * @fh_type: type of file handle 790 * @fh_type: type of file handle
1482 * @get_inode: filesystem callback to retrie 791 * @get_inode: filesystem callback to retrieve inode
1483 * 792 *
1484 * This function decodes @fid as long as it h 793 * This function decodes @fid as long as it has one of the well-known
1485 * Linux filehandle types and calls @get_inod 794 * Linux filehandle types and calls @get_inode on it to retrieve the
1486 * inode for the _parent_ object specified in 795 * inode for the _parent_ object specified in the file handle if it
1487 * is specified in the file handle, or NULL o 796 * is specified in the file handle, or NULL otherwise.
1488 */ 797 */
1489 struct dentry *generic_fh_to_parent(struct su 798 struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid,
1490 int fh_len, int fh_type, stru 799 int fh_len, int fh_type, struct inode *(*get_inode)
1491 (struct super_block * 800 (struct super_block *sb, u64 ino, u32 gen))
1492 { 801 {
1493 struct inode *inode = NULL; 802 struct inode *inode = NULL;
1494 803
1495 if (fh_len <= 2) 804 if (fh_len <= 2)
1496 return NULL; 805 return NULL;
1497 806
1498 switch (fh_type) { 807 switch (fh_type) {
1499 case FILEID_INO32_GEN_PARENT: 808 case FILEID_INO32_GEN_PARENT:
1500 inode = get_inode(sb, fid->i3 809 inode = get_inode(sb, fid->i32.parent_ino,
1501 (fh_len > 3 810 (fh_len > 3 ? fid->i32.parent_gen : 0));
1502 break; 811 break;
1503 } 812 }
1504 813
1505 return d_obtain_alias(inode); 814 return d_obtain_alias(inode);
1506 } 815 }
1507 EXPORT_SYMBOL_GPL(generic_fh_to_parent); 816 EXPORT_SYMBOL_GPL(generic_fh_to_parent);
1508 817
1509 /** !! 818 int simple_fsync(struct file *file, struct dentry *dentry, int datasync)
1510 * __generic_file_fsync - generic fsync imple <<
1511 * <<
1512 * @file: file to synchronize <<
1513 * @start: start offset in bytes <<
1514 * @end: end offset in bytes (inclusiv <<
1515 * @datasync: only synchronize essential me <<
1516 * <<
1517 * This is a generic implementation of the fs <<
1518 * filesystems which track all non-inode meta <<
1519 * hanging off the address_space structure. <<
1520 */ <<
1521 int __generic_file_fsync(struct file *file, l <<
1522 int datasync <<
1523 { 819 {
1524 struct inode *inode = file->f_mapping !! 820 struct writeback_control wbc = {
>> 821 .sync_mode = WB_SYNC_ALL,
>> 822 .nr_to_write = 0, /* metadata-only; caller takes care of data */
>> 823 };
>> 824 struct inode *inode = dentry->d_inode;
1525 int err; 825 int err;
1526 int ret; 826 int ret;
1527 827
1528 err = file_write_and_wait_range(file, <<
1529 if (err) <<
1530 return err; <<
1531 <<
1532 inode_lock(inode); <<
1533 ret = sync_mapping_buffers(inode->i_m 828 ret = sync_mapping_buffers(inode->i_mapping);
1534 if (!(inode->i_state & I_DIRTY_ALL)) !! 829 if (!(inode->i_state & I_DIRTY))
1535 goto out; !! 830 return ret;
1536 if (datasync && !(inode->i_state & I_ 831 if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
1537 goto out; !! 832 return ret;
1538 <<
1539 err = sync_inode_metadata(inode, 1); <<
1540 if (ret == 0) <<
1541 ret = err; <<
1542 833
1543 out: !! 834 err = sync_inode(inode, &wbc);
1544 inode_unlock(inode); <<
1545 /* check and advance again to catch e <<
1546 err = file_check_and_advance_wb_err(f <<
1547 if (ret == 0) 835 if (ret == 0)
1548 ret = err; 836 ret = err;
1549 return ret; 837 return ret;
1550 } 838 }
1551 EXPORT_SYMBOL(__generic_file_fsync); !! 839 EXPORT_SYMBOL(simple_fsync);
1552 <<
1553 /** <<
1554 * generic_file_fsync - generic fsync impleme <<
1555 * with flush <<
1556 * @file: file to synchronize <<
1557 * @start: start offset in bytes <<
1558 * @end: end offset in bytes (inclusiv <<
1559 * @datasync: only synchronize essential me <<
1560 * <<
1561 */ <<
1562 <<
1563 int generic_file_fsync(struct file *file, lof <<
1564 int datasync) <<
1565 { <<
1566 struct inode *inode = file->f_mapping <<
1567 int err; <<
1568 <<
1569 err = __generic_file_fsync(file, star <<
1570 if (err) <<
1571 return err; <<
1572 return blkdev_issue_flush(inode->i_sb <<
1573 } <<
1574 EXPORT_SYMBOL(generic_file_fsync); <<
1575 <<
1576 /** <<
1577 * generic_check_addressable - Check addressa <<
1578 * @blocksize_bits: log of file system bl <<
1579 * @num_blocks: number of blocks in f <<
1580 * <<
1581 * Determine whether a file system with @num_ <<
1582 * block size of 2**@blocksize_bits) is addre <<
1583 * and page cache of the system. Return 0 if <<
1584 */ <<
1585 int generic_check_addressable(unsigned blocks <<
1586 { <<
1587 u64 last_fs_block = num_blocks - 1; <<
1588 u64 last_fs_page = <<
1589 last_fs_block >> (PAGE_SHIFT <<
1590 <<
1591 if (unlikely(num_blocks == 0)) <<
1592 return 0; <<
1593 <<
1594 if ((blocksize_bits < 9) || (blocksiz <<
1595 return -EINVAL; <<
1596 <<
1597 if ((last_fs_block > (sector_t)(~0ULL <<
1598 (last_fs_page > (pgoff_t)(~0ULL)) <<
1599 return -EFBIG; <<
1600 } <<
1601 return 0; <<
1602 } <<
1603 EXPORT_SYMBOL(generic_check_addressable); <<
1604 <<
1605 /* <<
1606 * No-op implementation of ->fsync for in-mem <<
1607 */ <<
1608 int noop_fsync(struct file *file, loff_t star <<
1609 { <<
1610 return 0; <<
1611 } <<
1612 EXPORT_SYMBOL(noop_fsync); <<
1613 <<
1614 ssize_t noop_direct_IO(struct kiocb *iocb, st <<
1615 { <<
1616 /* <<
1617 * iomap based filesystems support di <<
1618 * this callback. However, it still n <<
1619 * inode->a_ops so that open/fcntl kn <<
1620 * generally supported. <<
1621 */ <<
1622 return -EINVAL; <<
1623 } <<
1624 EXPORT_SYMBOL_GPL(noop_direct_IO); <<
1625 <<
1626 /* Because kfree isn't assignment-compatible <<
1627 void kfree_link(void *p) <<
1628 { <<
1629 kfree(p); <<
1630 } <<
1631 EXPORT_SYMBOL(kfree_link); <<
1632 <<
1633 struct inode *alloc_anon_inode(struct super_b <<
1634 { <<
1635 static const struct address_space_ope <<
1636 .dirty_folio = noop_dirty_ <<
1637 }; <<
1638 struct inode *inode = new_inode_pseud <<
1639 <<
1640 if (!inode) <<
1641 return ERR_PTR(-ENOMEM); <<
1642 <<
1643 inode->i_ino = get_next_ino(); <<
1644 inode->i_mapping->a_ops = &anon_aops; <<
1645 <<
1646 /* <<
1647 * Mark the inode dirty from the very <<
1648 * that way it will never be moved to <<
1649 * list because mark_inode_dirty() wi <<
1650 * that it already _is_ on the dirty <<
1651 */ <<
1652 inode->i_state = I_DIRTY; <<
1653 inode->i_mode = S_IRUSR | S_IWUSR; <<
1654 inode->i_uid = current_fsuid(); <<
1655 inode->i_gid = current_fsgid(); <<
1656 inode->i_flags |= S_PRIVATE; <<
1657 simple_inode_init_ts(inode); <<
1658 return inode; <<
1659 } <<
1660 EXPORT_SYMBOL(alloc_anon_inode); <<
1661 <<
1662 /** <<
1663 * simple_nosetlease - generic helper for pro <<
1664 * @filp: file pointer <<
1665 * @arg: type of lease to obtain <<
1666 * @flp: new lease supplied for insertion <<
1667 * @priv: private data for lm_setup operation <<
1668 * <<
1669 * Generic helper for filesystems that do not <<
1670 * All arguments are ignored and it just retu <<
1671 */ <<
1672 int <<
1673 simple_nosetlease(struct file *filp, int arg, <<
1674 void **priv) <<
1675 { <<
1676 return -EINVAL; <<
1677 } <<
1678 EXPORT_SYMBOL(simple_nosetlease); <<
1679 <<
1680 /** <<
1681 * simple_get_link - generic helper to get th <<
1682 * @dentry: not used here <<
1683 * @inode: the symlink inode <<
1684 * @done: not used here <<
1685 * <<
1686 * Generic helper for filesystems to use for <<
1687 * the symlink target is stored in ->i_link. <<
1688 * since as an optimization the path lookup c <<
1689 * directly, without calling ->get_link(). B <<
1690 * to mark the inode_operations as being for <<
1691 * <<
1692 * Return: the symlink target <<
1693 */ <<
1694 const char *simple_get_link(struct dentry *de <<
1695 struct delayed_ca <<
1696 { <<
1697 return inode->i_link; <<
1698 } <<
1699 EXPORT_SYMBOL(simple_get_link); <<
1700 <<
1701 const struct inode_operations simple_symlink_ <<
1702 .get_link = simple_get_link, <<
1703 }; <<
1704 EXPORT_SYMBOL(simple_symlink_inode_operations <<
1705 <<
1706 /* <<
1707 * Operations for a permanently empty directo <<
1708 */ <<
1709 static struct dentry *empty_dir_lookup(struct <<
1710 { <<
1711 return ERR_PTR(-ENOENT); <<
1712 } <<
1713 <<
1714 static int empty_dir_getattr(struct mnt_idmap <<
1715 const struct pat <<
1716 u32 request_mask <<
1717 { <<
1718 struct inode *inode = d_inode(path->d <<
1719 generic_fillattr(&nop_mnt_idmap, requ <<
1720 return 0; <<
1721 } <<
1722 <<
1723 static int empty_dir_setattr(struct mnt_idmap <<
1724 struct dentry *d <<
1725 { <<
1726 return -EPERM; <<
1727 } <<
1728 <<
1729 static ssize_t empty_dir_listxattr(struct den <<
1730 { <<
1731 return -EOPNOTSUPP; <<
1732 } <<
1733 <<
1734 static const struct inode_operations empty_di <<
1735 .lookup = empty_dir_lookup, <<
1736 .permission = generic_permission, <<
1737 .setattr = empty_dir_setattr, <<
1738 .getattr = empty_dir_getattr, <<
1739 .listxattr = empty_dir_listxattr <<
1740 }; <<
1741 <<
1742 static loff_t empty_dir_llseek(struct file *f <<
1743 { <<
1744 /* An empty directory has two entries <<
1745 return generic_file_llseek_size(file, <<
1746 } <<
1747 <<
1748 static int empty_dir_readdir(struct file *fil <<
1749 { <<
1750 dir_emit_dots(file, ctx); <<
1751 return 0; <<
1752 } <<
1753 <<
1754 static const struct file_operations empty_dir <<
1755 .llseek = empty_dir_llseek, <<
1756 .read = generic_read_dir, <<
1757 .iterate_shared = empty_dir_readdir, <<
1758 .fsync = noop_fsync, <<
1759 }; <<
1760 <<
1761 <<
1762 void make_empty_dir_inode(struct inode *inode <<
1763 { <<
1764 set_nlink(inode, 2); <<
1765 inode->i_mode = S_IFDIR | S_IRUGO | S <<
1766 inode->i_uid = GLOBAL_ROOT_UID; <<
1767 inode->i_gid = GLOBAL_ROOT_GID; <<
1768 inode->i_rdev = 0; <<
1769 inode->i_size = 0; <<
1770 inode->i_blkbits = PAGE_SHIFT; <<
1771 inode->i_blocks = 0; <<
1772 <<
1773 inode->i_op = &empty_dir_inode_operat <<
1774 inode->i_opflags &= ~IOP_XATTR; <<
1775 inode->i_fop = &empty_dir_operations; <<
1776 } <<
1777 <<
1778 bool is_empty_dir_inode(struct inode *inode) <<
1779 { <<
1780 return (inode->i_fop == &empty_dir_op <<
1781 (inode->i_op == &empty_dir_in <<
1782 } <<
1783 <<
1784 #if IS_ENABLED(CONFIG_UNICODE) <<
1785 /** <<
1786 * generic_ci_d_compare - generic d_compare i <<
1787 * @dentry: dentry whose name we are chec <<
1788 * @len: len of name of dentry <<
1789 * @str: str pointer to name of dentry <<
1790 * @name: Name to compare against <<
1791 * <<
1792 * Return: 0 if names match, 1 if mismatch, o <<
1793 */ <<
1794 static int generic_ci_d_compare(const struct <<
1795 const char *s <<
1796 { <<
1797 const struct dentry *parent; <<
1798 const struct inode *dir; <<
1799 char strbuf[DNAME_INLINE_LEN]; <<
1800 struct qstr qstr; <<
1801 <<
1802 /* <<
1803 * Attempt a case-sensitive match fir <<
1804 * should cover most lookups, includi <<
1805 * applications that expect a case-se <<
1806 * <<
1807 * This comparison is safe under RCU <<
1808 * guarantees the consistency between <<
1809 * __d_lookup_rcu_op_compare() for de <<
1810 */ <<
1811 if (len == name->len && !memcmp(str, <<
1812 return 0; <<
1813 <<
1814 parent = READ_ONCE(dentry->d_parent); <<
1815 dir = READ_ONCE(parent->d_inode); <<
1816 if (!dir || !IS_CASEFOLDED(dir)) <<
1817 return 1; <<
1818 <<
1819 /* <<
1820 * If the dentry name is stored in-li <<
1821 * modified by a rename. If this hap <<
1822 * the lookup, so it doesn't matter w <<
1823 * However, it's unsafe to call utf8_ <<
1824 * string. Therefore, we have to cop <<
1825 */ <<
1826 if (len <= DNAME_INLINE_LEN - 1) { <<
1827 memcpy(strbuf, str, len); <<
1828 strbuf[len] = 0; <<
1829 str = strbuf; <<
1830 /* prevent compiler from opti <<
1831 barrier(); <<
1832 } <<
1833 qstr.len = len; <<
1834 qstr.name = str; <<
1835 <<
1836 return utf8_strncasecmp(dentry->d_sb- <<
1837 } <<
1838 <<
1839 /** <<
1840 * generic_ci_d_hash - generic d_hash impleme <<
1841 * @dentry: dentry of the parent director <<
1842 * @str: qstr of name whose hash we sh <<
1843 * <<
1844 * Return: 0 if hash was successful or unchan <<
1845 */ <<
1846 static int generic_ci_d_hash(const struct den <<
1847 { <<
1848 const struct inode *dir = READ_ONCE(d <<
1849 struct super_block *sb = dentry->d_sb <<
1850 const struct unicode_map *um = sb->s_ <<
1851 int ret; <<
1852 <<
1853 if (!dir || !IS_CASEFOLDED(dir)) <<
1854 return 0; <<
1855 840
1856 ret = utf8_casefold_hash(um, dentry, !! 841 EXPORT_SYMBOL(dcache_dir_close);
1857 if (ret < 0 && sb_has_strict_encoding !! 842 EXPORT_SYMBOL(dcache_dir_lseek);
1858 return -EINVAL; !! 843 EXPORT_SYMBOL(dcache_dir_open);
1859 return 0; !! 844 EXPORT_SYMBOL(dcache_readdir);
1860 } !! 845 EXPORT_SYMBOL(generic_read_dir);
1861 !! 846 EXPORT_SYMBOL(get_sb_pseudo);
1862 static const struct dentry_operations generic !! 847 EXPORT_SYMBOL(simple_write_begin);
1863 .d_hash = generic_ci_d_hash, !! 848 EXPORT_SYMBOL(simple_write_end);
1864 .d_compare = generic_ci_d_compare, !! 849 EXPORT_SYMBOL(simple_dir_inode_operations);
1865 #ifdef CONFIG_FS_ENCRYPTION !! 850 EXPORT_SYMBOL(simple_dir_operations);
1866 .d_revalidate = fscrypt_d_revalidate, !! 851 EXPORT_SYMBOL(simple_empty);
1867 #endif !! 852 EXPORT_SYMBOL(d_alloc_name);
1868 }; !! 853 EXPORT_SYMBOL(simple_fill_super);
1869 !! 854 EXPORT_SYMBOL(simple_getattr);
1870 /** !! 855 EXPORT_SYMBOL(simple_link);
1871 * generic_ci_match() - Match a name (case-in !! 856 EXPORT_SYMBOL(simple_lookup);
1872 * This is a filesystem helper for comparison !! 857 EXPORT_SYMBOL(simple_pin_fs);
1873 * generic_ci_d_compare should be used in VFS !! 858 EXPORT_UNUSED_SYMBOL(simple_prepare_write);
1874 * !! 859 EXPORT_SYMBOL(simple_readpage);
1875 * @parent: Inode of the parent of the dirent !! 860 EXPORT_SYMBOL(simple_release_fs);
1876 * @name: name under lookup. !! 861 EXPORT_SYMBOL(simple_rename);
1877 * @folded_name: Optional pre-folded name und !! 862 EXPORT_SYMBOL(simple_rmdir);
1878 * @de_name: Dirent name. !! 863 EXPORT_SYMBOL(simple_statfs);
1879 * @de_name_len: dirent name length. !! 864 EXPORT_SYMBOL(simple_sync_file);
1880 * !! 865 EXPORT_SYMBOL(simple_unlink);
1881 * Test whether a case-insensitive directory !! 866 EXPORT_SYMBOL(simple_read_from_buffer);
1882 * being searched. If @folded_name is provid !! 867 EXPORT_SYMBOL(memory_read_from_buffer);
1883 * recalculating the casefold of @name. !! 868 EXPORT_SYMBOL(simple_transaction_set);
1884 * !! 869 EXPORT_SYMBOL(simple_transaction_get);
1885 * Return: > 0 if the directory entry matches !! 870 EXPORT_SYMBOL(simple_transaction_read);
1886 * < 0 on error. !! 871 EXPORT_SYMBOL(simple_transaction_release);
1887 */ !! 872 EXPORT_SYMBOL_GPL(simple_attr_open);
1888 int generic_ci_match(const struct inode *pare !! 873 EXPORT_SYMBOL_GPL(simple_attr_release);
1889 const struct qstr *name, !! 874 EXPORT_SYMBOL_GPL(simple_attr_read);
1890 const struct qstr *folde !! 875 EXPORT_SYMBOL_GPL(simple_attr_write);
1891 const u8 *de_name, u32 d <<
1892 { <<
1893 const struct super_block *sb = parent <<
1894 const struct unicode_map *um = sb->s_ <<
1895 struct fscrypt_str decrypted_name = F <<
1896 struct qstr dirent = QSTR_INIT(de_nam <<
1897 int res = 0; <<
1898 <<
1899 if (IS_ENCRYPTED(parent)) { <<
1900 const struct fscrypt_str encr <<
1901 FSTR_INIT((u8 *) de_n <<
1902 <<
1903 if (WARN_ON_ONCE(!fscrypt_has <<
1904 return -EINVAL; <<
1905 <<
1906 decrypted_name.name = kmalloc <<
1907 if (!decrypted_name.name) <<
1908 return -ENOMEM; <<
1909 res = fscrypt_fname_disk_to_u <<
1910 <<
1911 if (res < 0) { <<
1912 kfree(decrypted_name. <<
1913 return res; <<
1914 } <<
1915 dirent.name = decrypted_name. <<
1916 dirent.len = decrypted_name.l <<
1917 } <<
1918 <<
1919 /* <<
1920 * Attempt a case-sensitive match fir <<
1921 * should cover most lookups, includi <<
1922 * applications that expect a case-se <<
1923 */ <<
1924 <<
1925 if (dirent.len == name->len && <<
1926 !memcmp(name->name, dirent.name, <<
1927 goto out; <<
1928 <<
1929 if (folded_name->name) <<
1930 res = utf8_strncasecmp_folded <<
1931 else <<
1932 res = utf8_strncasecmp(um, na <<
1933 <<
1934 out: <<
1935 kfree(decrypted_name.name); <<
1936 if (res < 0 && sb_has_strict_encoding <<
1937 pr_err_ratelimited("Directory <<
1938 return 0; <<
1939 } <<
1940 return !res; <<
1941 } <<
1942 EXPORT_SYMBOL(generic_ci_match); <<
1943 #endif <<
1944 <<
1945 #ifdef CONFIG_FS_ENCRYPTION <<
1946 static const struct dentry_operations generic <<
1947 .d_revalidate = fscrypt_d_revalidate, <<
1948 }; <<
1949 #endif <<
1950 <<
1951 /** <<
1952 * generic_set_sb_d_ops - helper for choosing <<
1953 * filesystem-wide dentry operations for the <<
1954 * @sb: superblock to be configured <<
1955 * <<
1956 * Filesystems supporting casefolding and/or <<
1957 * helper at mount-time to configure sb->s_d_ <<
1958 * operations required for the enabled featur <<
1959 * called after these have been configured, b <<
1960 * is created. <<
1961 */ <<
1962 void generic_set_sb_d_ops(struct super_block <<
1963 { <<
1964 #if IS_ENABLED(CONFIG_UNICODE) <<
1965 if (sb->s_encoding) { <<
1966 sb->s_d_op = &generic_ci_dent <<
1967 return; <<
1968 } <<
1969 #endif <<
1970 #ifdef CONFIG_FS_ENCRYPTION <<
1971 if (sb->s_cop) { <<
1972 sb->s_d_op = &generic_encrypt <<
1973 return; <<
1974 } <<
1975 #endif <<
1976 } <<
1977 EXPORT_SYMBOL(generic_set_sb_d_ops); <<
1978 <<
1979 /** <<
1980 * inode_maybe_inc_iversion - increments i_ve <<
1981 * @inode: inode with the i_version that shou <<
1982 * @force: increment the counter even if it's <<
1983 * <<
1984 * Every time the inode is modified, the i_ve <<
1985 * changed by any observer. <<
1986 * <<
1987 * If "force" is set or the QUERIED flag is s <<
1988 * the value, and clear the queried flag. <<
1989 * <<
1990 * In the common case where neither is set, t <<
1991 * updating i_version. <<
1992 * <<
1993 * If this function returns false, and no oth <<
1994 * can avoid logging the metadata. <<
1995 */ <<
1996 bool inode_maybe_inc_iversion(struct inode *i <<
1997 { <<
1998 u64 cur, new; <<
1999 <<
2000 /* <<
2001 * The i_version field is not strictl <<
2002 * information, but the legacy inode_ <<
2003 * to serialize increments. <<
2004 * <<
2005 * We add a full memory barrier to en <<
2006 * with other state is preserved (eit <<
2007 * or explicitly from smp_mb if we do <<
2008 * the former). <<
2009 * <<
2010 * These barriers pair with inode_que <<
2011 */ <<
2012 cur = inode_peek_iversion_raw(inode); <<
2013 if (!force && !(cur & I_VERSION_QUERI <<
2014 smp_mb(); <<
2015 cur = inode_peek_iversion_raw <<
2016 } <<
2017 <<
2018 do { <<
2019 /* If flag is clear then we n <<
2020 if (!force && !(cur & I_VERSI <<
2021 return false; <<
2022 <<
2023 /* Since lowest bit is flag, <<
2024 new = (cur & ~I_VERSION_QUERI <<
2025 } while (!atomic64_try_cmpxchg(&inode <<
2026 return true; <<
2027 } <<
2028 EXPORT_SYMBOL(inode_maybe_inc_iversion); <<
2029 <<
2030 /** <<
2031 * inode_query_iversion - read i_version for <<
2032 * @inode: inode from which i_version should <<
2033 * <<
2034 * Read the inode i_version counter. This sho <<
2035 * to store the returned i_version for later <<
2036 * that a later query of the i_version will r <<
2037 * anything has changed. <<
2038 * <<
2039 * In this implementation, we fetch the curre <<
2040 * then try to swap it into place with a cmpx <<
2041 * that fails, we try again with the newly fe <<
2042 */ <<
2043 u64 inode_query_iversion(struct inode *inode) <<
2044 { <<
2045 u64 cur, new; <<
2046 bool fenced = false; <<
2047 <<
2048 /* <<
2049 * Memory barriers (implicit in cmpxc <<
2050 * inode_maybe_inc_iversion(), see th <<
2051 */ <<
2052 cur = inode_peek_iversion_raw(inode); <<
2053 do { <<
2054 /* If flag is already set, th <<
2055 if (cur & I_VERSION_QUERIED) <<
2056 if (!fenced) <<
2057 smp_mb(); <<
2058 break; <<
2059 } <<
2060 <<
2061 fenced = true; <<
2062 new = cur | I_VERSION_QUERIED <<
2063 } while (!atomic64_try_cmpxchg(&inode <<
2064 return cur >> I_VERSION_QUERIED_SHIFT <<
2065 } <<
2066 EXPORT_SYMBOL(inode_query_iversion); <<
2067 <<
2068 ssize_t direct_write_fallback(struct kiocb *i <<
2069 ssize_t direct_written, ssize <<
2070 { <<
2071 struct address_space *mapping = iocb- <<
2072 loff_t pos = iocb->ki_pos - buffered_ <<
2073 loff_t end = iocb->ki_pos - 1; <<
2074 int err; <<
2075 <<
2076 /* <<
2077 * If the buffered write fallback ret <<
2078 * the number of bytes which were wri <<
2079 * code if that was zero. <<
2080 * <<
2081 * Note that this differs from normal <<
2082 * return -EFOO even if some bytes we <<
2083 */ <<
2084 if (unlikely(buffered_written < 0)) { <<
2085 if (direct_written) <<
2086 return direct_written <<
2087 return buffered_written; <<
2088 } <<
2089 <<
2090 /* <<
2091 * We need to ensure that the page ca <<
2092 * invalidated to preserve the expect <<
2093 */ <<
2094 err = filemap_write_and_wait_range(ma <<
2095 if (err < 0) { <<
2096 /* <<
2097 * We don't know how much we <<
2098 * bytes which were direct-wr <<
2099 */ <<
2100 iocb->ki_pos -= buffered_writ <<
2101 if (direct_written) <<
2102 return direct_written <<
2103 return err; <<
2104 } <<
2105 invalidate_mapping_pages(mapping, pos <<
2106 return direct_written + buffered_writ <<
2107 } <<
2108 EXPORT_SYMBOL_GPL(direct_write_fallback); <<
2109 <<
2110 /** <<
2111 * simple_inode_init_ts - initialize the time <<
2112 * @inode: inode to be initialized <<
2113 * <<
2114 * When a new inode is created, most filesyst <<
2115 * current time. Add a helper to do this. <<
2116 */ <<
2117 struct timespec64 simple_inode_init_ts(struct <<
2118 { <<
2119 struct timespec64 ts = inode_set_ctim <<
2120 <<
2121 inode_set_atime_to_ts(inode, ts); <<
2122 inode_set_mtime_to_ts(inode, ts); <<
2123 return ts; <<
2124 } <<
2125 EXPORT_SYMBOL(simple_inode_init_ts); <<
2126 <<
2127 static inline struct dentry *get_stashed_dent <<
2128 { <<
2129 struct dentry *dentry; <<
2130 <<
2131 guard(rcu)(); <<
2132 dentry = rcu_dereference(*stashed); <<
2133 if (!dentry) <<
2134 return NULL; <<
2135 if (!lockref_get_not_dead(&dentry->d_ <<
2136 return NULL; <<
2137 return dentry; <<
2138 } <<
2139 <<
2140 static struct dentry *prepare_anon_dentry(str <<
2141 str <<
2142 voi <<
2143 { <<
2144 struct dentry *dentry; <<
2145 struct inode *inode; <<
2146 const struct stashed_operations *sops <<
2147 int ret; <<
2148 <<
2149 inode = new_inode_pseudo(sb); <<
2150 if (!inode) { <<
2151 sops->put_data(data); <<
2152 return ERR_PTR(-ENOMEM); <<
2153 } <<
2154 <<
2155 inode->i_flags |= S_IMMUTABLE; <<
2156 inode->i_mode = S_IFREG; <<
2157 simple_inode_init_ts(inode); <<
2158 <<
2159 ret = sops->init_inode(inode, data); <<
2160 if (ret < 0) { <<
2161 iput(inode); <<
2162 return ERR_PTR(ret); <<
2163 } <<
2164 <<
2165 /* Notice when this is changed. */ <<
2166 WARN_ON_ONCE(!S_ISREG(inode->i_mode)) <<
2167 WARN_ON_ONCE(!IS_IMMUTABLE(inode)); <<
2168 <<
2169 dentry = d_alloc_anon(sb); <<
2170 if (!dentry) { <<
2171 iput(inode); <<
2172 return ERR_PTR(-ENOMEM); <<
2173 } <<
2174 <<
2175 /* Store address of location where de <<
2176 dentry->d_fsdata = stashed; <<
2177 <<
2178 /* @data is now owned by the fs */ <<
2179 d_instantiate(dentry, inode); <<
2180 return dentry; <<
2181 } <<
2182 <<
2183 static struct dentry *stash_dentry(struct den <<
2184 struct den <<
2185 { <<
2186 guard(rcu)(); <<
2187 for (;;) { <<
2188 struct dentry *old; <<
2189 <<
2190 /* Assume any old dentry was <<
2191 old = cmpxchg(stashed, NULL, <<
2192 if (likely(!old)) <<
2193 return dentry; <<
2194 <<
2195 /* Check if somebody else ins <<
2196 if (lockref_get_not_dead(&old <<
2197 return old; <<
2198 <<
2199 /* There's an old dead dentry <<
2200 if (likely(try_cmpxchg(stashe <<
2201 return dentry; <<
2202 } <<
2203 } <<
2204 <<
2205 /** <<
2206 * path_from_stashed - create path from stash <<
2207 * @stashed: where to retrieve or stash de <<
2208 * @mnt: mnt of the filesystems to use <<
2209 * @data: data to store in inode->i_pri <<
2210 * @path: path to create <<
2211 * <<
2212 * The function tries to retrieve a stashed d <<
2213 * is still valid then it will be reused. If <<
2214 * will allocate a new dentry and inode. It w <<
2215 * can reuse an existing dentry in case one h <<
2216 * update @stashed with the newly added dentr <<
2217 * <<
2218 * Special-purpose helper for nsfs and pidfs. <<
2219 * <<
2220 * Return: On success zero and on failure a n <<
2221 */ <<
2222 int path_from_stashed(struct dentry **stashed <<
2223 struct path *path) <<
2224 { <<
2225 struct dentry *dentry; <<
2226 const struct stashed_operations *sops <<
2227 <<
2228 /* See if dentry can be reused. */ <<
2229 path->dentry = get_stashed_dentry(sta <<
2230 if (path->dentry) { <<
2231 sops->put_data(data); <<
2232 goto out_path; <<
2233 } <<
2234 <<
2235 /* Allocate a new dentry. */ <<
2236 dentry = prepare_anon_dentry(stashed, <<
2237 if (IS_ERR(dentry)) <<
2238 return PTR_ERR(dentry); <<
2239 <<
2240 /* Added a new dentry. @data is now o <<
2241 path->dentry = stash_dentry(stashed, <<
2242 if (path->dentry != dentry) <<
2243 dput(dentry); <<
2244 <<
2245 out_path: <<
2246 WARN_ON_ONCE(path->dentry->d_fsdata ! <<
2247 WARN_ON_ONCE(d_inode(path->dentry)->i <<
2248 path->mnt = mntget(mnt); <<
2249 return 0; <<
2250 } <<
2251 <<
2252 void stashed_dentry_prune(struct dentry *dent <<
2253 { <<
2254 struct dentry **stashed = dentry->d_f <<
2255 struct inode *inode = d_inode(dentry) <<
2256 <<
2257 if (WARN_ON_ONCE(!stashed)) <<
2258 return; <<
2259 <<
2260 if (!inode) <<
2261 return; <<
2262 <<
2263 /* <<
2264 * Only replace our own @dentry as so <<
2265 * already cleared out @dentry and st <<
2266 * dentry in there. <<
2267 */ <<
2268 cmpxchg(stashed, dentry, NULL); <<
2269 } <<
2270 876
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