1 // SPDX-License-Identifier: GPL-2.0-only 1 // SPDX-License-Identifier: GPL-2.0-only
2 /* 2 /*
3 * fs/libfs.c 3 * fs/libfs.c
4 * Library for filesystems writers. 4 * Library for filesystems writers.
5 */ 5 */
6 6
7 #include <linux/blkdev.h> 7 #include <linux/blkdev.h>
8 #include <linux/export.h> 8 #include <linux/export.h>
9 #include <linux/pagemap.h> 9 #include <linux/pagemap.h>
10 #include <linux/slab.h> 10 #include <linux/slab.h>
11 #include <linux/cred.h> 11 #include <linux/cred.h>
12 #include <linux/mount.h> 12 #include <linux/mount.h>
13 #include <linux/vfs.h> 13 #include <linux/vfs.h>
14 #include <linux/quotaops.h> 14 #include <linux/quotaops.h>
15 #include <linux/mutex.h> 15 #include <linux/mutex.h>
16 #include <linux/namei.h> 16 #include <linux/namei.h>
17 #include <linux/exportfs.h> 17 #include <linux/exportfs.h>
18 #include <linux/iversion.h> <<
19 #include <linux/writeback.h> 18 #include <linux/writeback.h>
20 #include <linux/buffer_head.h> /* sync_mapping 19 #include <linux/buffer_head.h> /* sync_mapping_buffers */
21 #include <linux/fs_context.h> 20 #include <linux/fs_context.h>
22 #include <linux/pseudo_fs.h> 21 #include <linux/pseudo_fs.h>
23 #include <linux/fsnotify.h> 22 #include <linux/fsnotify.h>
24 #include <linux/unicode.h> 23 #include <linux/unicode.h>
25 #include <linux/fscrypt.h> 24 #include <linux/fscrypt.h>
26 #include <linux/pidfs.h> <<
27 25
28 #include <linux/uaccess.h> 26 #include <linux/uaccess.h>
29 27
30 #include "internal.h" 28 #include "internal.h"
31 29
32 int simple_getattr(struct mnt_idmap *idmap, co !! 30 int simple_getattr(const struct path *path, struct kstat *stat,
33 struct kstat *stat, u32 req !! 31 u32 request_mask, unsigned int query_flags)
34 unsigned int query_flags) <<
35 { 32 {
36 struct inode *inode = d_inode(path->de 33 struct inode *inode = d_inode(path->dentry);
37 generic_fillattr(&nop_mnt_idmap, reque !! 34 generic_fillattr(inode, stat);
38 stat->blocks = inode->i_mapping->nrpag 35 stat->blocks = inode->i_mapping->nrpages << (PAGE_SHIFT - 9);
39 return 0; 36 return 0;
40 } 37 }
41 EXPORT_SYMBOL(simple_getattr); 38 EXPORT_SYMBOL(simple_getattr);
42 39
43 int simple_statfs(struct dentry *dentry, struc 40 int simple_statfs(struct dentry *dentry, struct kstatfs *buf)
44 { 41 {
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; 42 buf->f_type = dentry->d_sb->s_magic;
49 buf->f_bsize = PAGE_SIZE; 43 buf->f_bsize = PAGE_SIZE;
50 buf->f_namelen = NAME_MAX; 44 buf->f_namelen = NAME_MAX;
51 return 0; 45 return 0;
52 } 46 }
53 EXPORT_SYMBOL(simple_statfs); 47 EXPORT_SYMBOL(simple_statfs);
54 48
55 /* 49 /*
56 * Retaining negative dentries for an in-memor 50 * Retaining negative dentries for an in-memory filesystem just wastes
57 * memory and lookup time: arrange for them to 51 * memory and lookup time: arrange for them to be deleted immediately.
58 */ 52 */
59 int always_delete_dentry(const struct dentry * 53 int always_delete_dentry(const struct dentry *dentry)
60 { 54 {
61 return 1; 55 return 1;
62 } 56 }
63 EXPORT_SYMBOL(always_delete_dentry); 57 EXPORT_SYMBOL(always_delete_dentry);
64 58
65 const struct dentry_operations simple_dentry_o 59 const struct dentry_operations simple_dentry_operations = {
66 .d_delete = always_delete_dentry, 60 .d_delete = always_delete_dentry,
67 }; 61 };
68 EXPORT_SYMBOL(simple_dentry_operations); 62 EXPORT_SYMBOL(simple_dentry_operations);
69 63
70 /* 64 /*
71 * Lookup the data. This is trivial - if the d 65 * Lookup the data. This is trivial - if the dentry didn't already
72 * exist, we know it is negative. Set d_op to 66 * exist, we know it is negative. Set d_op to delete negative dentries.
73 */ 67 */
74 struct dentry *simple_lookup(struct inode *dir 68 struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
75 { 69 {
76 if (dentry->d_name.len > NAME_MAX) 70 if (dentry->d_name.len > NAME_MAX)
77 return ERR_PTR(-ENAMETOOLONG); 71 return ERR_PTR(-ENAMETOOLONG);
78 if (!dentry->d_sb->s_d_op) 72 if (!dentry->d_sb->s_d_op)
79 d_set_d_op(dentry, &simple_den 73 d_set_d_op(dentry, &simple_dentry_operations);
80 d_add(dentry, NULL); 74 d_add(dentry, NULL);
81 return NULL; 75 return NULL;
82 } 76 }
83 EXPORT_SYMBOL(simple_lookup); 77 EXPORT_SYMBOL(simple_lookup);
84 78
85 int dcache_dir_open(struct inode *inode, struc 79 int dcache_dir_open(struct inode *inode, struct file *file)
86 { 80 {
87 file->private_data = d_alloc_cursor(fi 81 file->private_data = d_alloc_cursor(file->f_path.dentry);
88 82
89 return file->private_data ? 0 : -ENOME 83 return file->private_data ? 0 : -ENOMEM;
90 } 84 }
91 EXPORT_SYMBOL(dcache_dir_open); 85 EXPORT_SYMBOL(dcache_dir_open);
92 86
93 int dcache_dir_close(struct inode *inode, stru 87 int dcache_dir_close(struct inode *inode, struct file *file)
94 { 88 {
95 dput(file->private_data); 89 dput(file->private_data);
96 return 0; 90 return 0;
97 } 91 }
98 EXPORT_SYMBOL(dcache_dir_close); 92 EXPORT_SYMBOL(dcache_dir_close);
99 93
100 /* parent is locked at least shared */ 94 /* parent is locked at least shared */
101 /* 95 /*
102 * Returns an element of siblings' list. 96 * Returns an element of siblings' list.
103 * We are looking for <count>th positive after 97 * We are looking for <count>th positive after <p>; if
104 * found, dentry is grabbed and returned to ca 98 * found, dentry is grabbed and returned to caller.
105 * If no such element exists, NULL is returned 99 * If no such element exists, NULL is returned.
106 */ 100 */
107 static struct dentry *scan_positives(struct de 101 static struct dentry *scan_positives(struct dentry *cursor,
108 struct !! 102 struct list_head *p,
109 loff_t 103 loff_t count,
110 struct 104 struct dentry *last)
111 { 105 {
112 struct dentry *dentry = cursor->d_pare 106 struct dentry *dentry = cursor->d_parent, *found = NULL;
113 107
114 spin_lock(&dentry->d_lock); 108 spin_lock(&dentry->d_lock);
115 while (*p) { !! 109 while ((p = p->next) != &dentry->d_subdirs) {
116 struct dentry *d = hlist_entry !! 110 struct dentry *d = list_entry(p, struct dentry, d_child);
117 p = &d->d_sib.next; <<
118 // we must at least skip curso 111 // we must at least skip cursors, to avoid livelocks
119 if (d->d_flags & DCACHE_DENTRY 112 if (d->d_flags & DCACHE_DENTRY_CURSOR)
120 continue; 113 continue;
121 if (simple_positive(d) && !--c 114 if (simple_positive(d) && !--count) {
122 spin_lock_nested(&d->d 115 spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
123 if (simple_positive(d) 116 if (simple_positive(d))
124 found = dget_d 117 found = dget_dlock(d);
125 spin_unlock(&d->d_lock 118 spin_unlock(&d->d_lock);
126 if (likely(found)) 119 if (likely(found))
127 break; 120 break;
128 count = 1; 121 count = 1;
129 } 122 }
130 if (need_resched()) { 123 if (need_resched()) {
131 if (!hlist_unhashed(&c !! 124 list_move(&cursor->d_child, p);
132 __hlist_del(&c !! 125 p = &cursor->d_child;
133 hlist_add_behind(&curs <<
134 p = &cursor->d_sib.nex <<
135 spin_unlock(&dentry->d 126 spin_unlock(&dentry->d_lock);
136 cond_resched(); 127 cond_resched();
137 spin_lock(&dentry->d_l 128 spin_lock(&dentry->d_lock);
138 } 129 }
139 } 130 }
140 spin_unlock(&dentry->d_lock); 131 spin_unlock(&dentry->d_lock);
141 dput(last); 132 dput(last);
142 return found; 133 return found;
143 } 134 }
144 135
145 loff_t dcache_dir_lseek(struct file *file, lof 136 loff_t dcache_dir_lseek(struct file *file, loff_t offset, int whence)
146 { 137 {
147 struct dentry *dentry = file->f_path.d 138 struct dentry *dentry = file->f_path.dentry;
148 switch (whence) { 139 switch (whence) {
149 case 1: 140 case 1:
150 offset += file->f_pos; 141 offset += file->f_pos;
151 fallthrough; 142 fallthrough;
152 case 0: 143 case 0:
153 if (offset >= 0) 144 if (offset >= 0)
154 break; 145 break;
155 fallthrough; 146 fallthrough;
156 default: 147 default:
157 return -EINVAL; 148 return -EINVAL;
158 } 149 }
159 if (offset != file->f_pos) { 150 if (offset != file->f_pos) {
160 struct dentry *cursor = file-> 151 struct dentry *cursor = file->private_data;
161 struct dentry *to = NULL; 152 struct dentry *to = NULL;
162 153
163 inode_lock_shared(dentry->d_in 154 inode_lock_shared(dentry->d_inode);
164 155
165 if (offset > 2) 156 if (offset > 2)
166 to = scan_positives(cu !! 157 to = scan_positives(cursor, &dentry->d_subdirs,
167 of 158 offset - 2, NULL);
168 spin_lock(&dentry->d_lock); 159 spin_lock(&dentry->d_lock);
169 hlist_del_init(&cursor->d_sib) <<
170 if (to) 160 if (to)
171 hlist_add_behind(&curs !! 161 list_move(&cursor->d_child, &to->d_child);
>> 162 else
>> 163 list_del_init(&cursor->d_child);
172 spin_unlock(&dentry->d_lock); 164 spin_unlock(&dentry->d_lock);
173 dput(to); 165 dput(to);
174 166
175 file->f_pos = offset; 167 file->f_pos = offset;
176 168
177 inode_unlock_shared(dentry->d_ 169 inode_unlock_shared(dentry->d_inode);
178 } 170 }
179 return offset; 171 return offset;
180 } 172 }
181 EXPORT_SYMBOL(dcache_dir_lseek); 173 EXPORT_SYMBOL(dcache_dir_lseek);
182 174
>> 175 /* Relationship between i_mode and the DT_xxx types */
>> 176 static inline unsigned char dt_type(struct inode *inode)
>> 177 {
>> 178 return (inode->i_mode >> 12) & 15;
>> 179 }
>> 180
183 /* 181 /*
184 * Directory is locked and all positive dentri 182 * Directory is locked and all positive dentries in it are safe, since
185 * for ramfs-type trees they can't go away wit 183 * for ramfs-type trees they can't go away without unlink() or rmdir(),
186 * both impossible due to the lock on director 184 * both impossible due to the lock on directory.
187 */ 185 */
188 186
189 int dcache_readdir(struct file *file, struct d 187 int dcache_readdir(struct file *file, struct dir_context *ctx)
190 { 188 {
191 struct dentry *dentry = file->f_path.d 189 struct dentry *dentry = file->f_path.dentry;
192 struct dentry *cursor = file->private_ 190 struct dentry *cursor = file->private_data;
>> 191 struct list_head *anchor = &dentry->d_subdirs;
193 struct dentry *next = NULL; 192 struct dentry *next = NULL;
194 struct hlist_node **p; !! 193 struct list_head *p;
195 194
196 if (!dir_emit_dots(file, ctx)) 195 if (!dir_emit_dots(file, ctx))
197 return 0; 196 return 0;
198 197
199 if (ctx->pos == 2) 198 if (ctx->pos == 2)
200 p = &dentry->d_children.first; !! 199 p = anchor;
>> 200 else if (!list_empty(&cursor->d_child))
>> 201 p = &cursor->d_child;
201 else 202 else
202 p = &cursor->d_sib.next; !! 203 return 0;
203 204
204 while ((next = scan_positives(cursor, 205 while ((next = scan_positives(cursor, p, 1, next)) != NULL) {
205 if (!dir_emit(ctx, next->d_nam 206 if (!dir_emit(ctx, next->d_name.name, next->d_name.len,
206 d_inode(next)->i !! 207 d_inode(next)->i_ino, dt_type(d_inode(next))))
207 fs_umode_to_dtyp <<
208 break; 208 break;
209 ctx->pos++; 209 ctx->pos++;
210 p = &next->d_sib.next; !! 210 p = &next->d_child;
211 } 211 }
212 spin_lock(&dentry->d_lock); 212 spin_lock(&dentry->d_lock);
213 hlist_del_init(&cursor->d_sib); <<
214 if (next) 213 if (next)
215 hlist_add_before(&cursor->d_si !! 214 list_move_tail(&cursor->d_child, &next->d_child);
>> 215 else
>> 216 list_del_init(&cursor->d_child);
216 spin_unlock(&dentry->d_lock); 217 spin_unlock(&dentry->d_lock);
217 dput(next); 218 dput(next);
218 219
219 return 0; 220 return 0;
220 } 221 }
221 EXPORT_SYMBOL(dcache_readdir); 222 EXPORT_SYMBOL(dcache_readdir);
222 223
223 ssize_t generic_read_dir(struct file *filp, ch 224 ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos)
224 { 225 {
225 return -EISDIR; 226 return -EISDIR;
226 } 227 }
227 EXPORT_SYMBOL(generic_read_dir); 228 EXPORT_SYMBOL(generic_read_dir);
228 229
229 const struct file_operations simple_dir_operat 230 const struct file_operations simple_dir_operations = {
230 .open = dcache_dir_open, 231 .open = dcache_dir_open,
231 .release = dcache_dir_close, 232 .release = dcache_dir_close,
232 .llseek = dcache_dir_lseek, 233 .llseek = dcache_dir_lseek,
233 .read = generic_read_dir, 234 .read = generic_read_dir,
234 .iterate_shared = dcache_readdir, 235 .iterate_shared = dcache_readdir,
235 .fsync = noop_fsync, 236 .fsync = noop_fsync,
236 }; 237 };
237 EXPORT_SYMBOL(simple_dir_operations); 238 EXPORT_SYMBOL(simple_dir_operations);
238 239
239 const struct inode_operations simple_dir_inode 240 const struct inode_operations simple_dir_inode_operations = {
240 .lookup = simple_lookup, 241 .lookup = simple_lookup,
241 }; 242 };
242 EXPORT_SYMBOL(simple_dir_inode_operations); 243 EXPORT_SYMBOL(simple_dir_inode_operations);
243 244
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 245 static struct dentry *find_next_child(struct dentry *parent, struct dentry *prev)
591 { 246 {
592 struct dentry *child = NULL, *d; !! 247 struct dentry *child = NULL;
>> 248 struct list_head *p = prev ? &prev->d_child : &parent->d_subdirs;
593 249
594 spin_lock(&parent->d_lock); 250 spin_lock(&parent->d_lock);
595 d = prev ? d_next_sibling(prev) : d_fi !! 251 while ((p = p->next) != &parent->d_subdirs) {
596 hlist_for_each_entry_from(d, d_sib) { !! 252 struct dentry *d = container_of(p, struct dentry, d_child);
597 if (simple_positive(d)) { 253 if (simple_positive(d)) {
598 spin_lock_nested(&d->d 254 spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
599 if (simple_positive(d) 255 if (simple_positive(d))
600 child = dget_d 256 child = dget_dlock(d);
601 spin_unlock(&d->d_lock 257 spin_unlock(&d->d_lock);
602 if (likely(child)) 258 if (likely(child))
603 break; 259 break;
604 } 260 }
605 } 261 }
606 spin_unlock(&parent->d_lock); 262 spin_unlock(&parent->d_lock);
607 dput(prev); 263 dput(prev);
608 return child; 264 return child;
609 } 265 }
610 266
611 void simple_recursive_removal(struct dentry *d 267 void simple_recursive_removal(struct dentry *dentry,
612 void (*callback) 268 void (*callback)(struct dentry *))
613 { 269 {
614 struct dentry *this = dget(dentry); 270 struct dentry *this = dget(dentry);
615 while (true) { 271 while (true) {
616 struct dentry *victim = NULL, 272 struct dentry *victim = NULL, *child;
617 struct inode *inode = this->d_ 273 struct inode *inode = this->d_inode;
618 274
619 inode_lock(inode); 275 inode_lock(inode);
620 if (d_is_dir(this)) 276 if (d_is_dir(this))
621 inode->i_flags |= S_DE 277 inode->i_flags |= S_DEAD;
622 while ((child = find_next_chil 278 while ((child = find_next_child(this, victim)) == NULL) {
623 // kill and ascend 279 // kill and ascend
624 // update metadata whi 280 // update metadata while it's still locked
625 inode_set_ctime_curren !! 281 inode->i_ctime = current_time(inode);
626 clear_nlink(inode); 282 clear_nlink(inode);
627 inode_unlock(inode); 283 inode_unlock(inode);
628 victim = this; 284 victim = this;
629 this = this->d_parent; 285 this = this->d_parent;
630 inode = this->d_inode; 286 inode = this->d_inode;
631 inode_lock(inode); 287 inode_lock(inode);
632 if (simple_positive(vi 288 if (simple_positive(victim)) {
633 d_invalidate(v 289 d_invalidate(victim); // avoid lost mounts
634 if (d_is_dir(v 290 if (d_is_dir(victim))
635 fsnoti 291 fsnotify_rmdir(inode, victim);
636 else 292 else
637 fsnoti 293 fsnotify_unlink(inode, victim);
638 if (callback) 294 if (callback)
639 callba 295 callback(victim);
640 dput(victim); 296 dput(victim); // unpin it
641 } 297 }
642 if (victim == dentry) 298 if (victim == dentry) {
643 inode_set_mtim !! 299 inode->i_ctime = inode->i_mtime =
644 !! 300 current_time(inode);
645 if (d_is_dir(d 301 if (d_is_dir(dentry))
646 drop_n 302 drop_nlink(inode);
647 inode_unlock(i 303 inode_unlock(inode);
648 dput(dentry); 304 dput(dentry);
649 return; 305 return;
650 } 306 }
651 } 307 }
652 inode_unlock(inode); 308 inode_unlock(inode);
653 this = child; 309 this = child;
654 } 310 }
655 } 311 }
656 EXPORT_SYMBOL(simple_recursive_removal); 312 EXPORT_SYMBOL(simple_recursive_removal);
657 313
658 static const struct super_operations simple_su 314 static const struct super_operations simple_super_operations = {
659 .statfs = simple_statfs, 315 .statfs = simple_statfs,
660 }; 316 };
661 317
662 static int pseudo_fs_fill_super(struct super_b 318 static int pseudo_fs_fill_super(struct super_block *s, struct fs_context *fc)
663 { 319 {
664 struct pseudo_fs_context *ctx = fc->fs 320 struct pseudo_fs_context *ctx = fc->fs_private;
665 struct inode *root; 321 struct inode *root;
666 322
667 s->s_maxbytes = MAX_LFS_FILESIZE; 323 s->s_maxbytes = MAX_LFS_FILESIZE;
668 s->s_blocksize = PAGE_SIZE; 324 s->s_blocksize = PAGE_SIZE;
669 s->s_blocksize_bits = PAGE_SHIFT; 325 s->s_blocksize_bits = PAGE_SHIFT;
670 s->s_magic = ctx->magic; 326 s->s_magic = ctx->magic;
671 s->s_op = ctx->ops ?: &simple_super_op 327 s->s_op = ctx->ops ?: &simple_super_operations;
672 s->s_xattr = ctx->xattr; 328 s->s_xattr = ctx->xattr;
673 s->s_time_gran = 1; 329 s->s_time_gran = 1;
674 root = new_inode(s); 330 root = new_inode(s);
675 if (!root) 331 if (!root)
676 return -ENOMEM; 332 return -ENOMEM;
677 333
678 /* 334 /*
679 * since this is the first inode, make 335 * since this is the first inode, make it number 1. New inodes created
680 * after this must take care not to co 336 * after this must take care not to collide with it (by passing
681 * max_reserved of 1 to iunique). 337 * max_reserved of 1 to iunique).
682 */ 338 */
683 root->i_ino = 1; 339 root->i_ino = 1;
684 root->i_mode = S_IFDIR | S_IRUSR | S_I 340 root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR;
685 simple_inode_init_ts(root); !! 341 root->i_atime = root->i_mtime = root->i_ctime = current_time(root);
686 s->s_root = d_make_root(root); 342 s->s_root = d_make_root(root);
687 if (!s->s_root) 343 if (!s->s_root)
688 return -ENOMEM; 344 return -ENOMEM;
689 s->s_d_op = ctx->dops; 345 s->s_d_op = ctx->dops;
690 return 0; 346 return 0;
691 } 347 }
692 348
693 static int pseudo_fs_get_tree(struct fs_contex 349 static int pseudo_fs_get_tree(struct fs_context *fc)
694 { 350 {
695 return get_tree_nodev(fc, pseudo_fs_fi 351 return get_tree_nodev(fc, pseudo_fs_fill_super);
696 } 352 }
697 353
698 static void pseudo_fs_free(struct fs_context * 354 static void pseudo_fs_free(struct fs_context *fc)
699 { 355 {
700 kfree(fc->fs_private); 356 kfree(fc->fs_private);
701 } 357 }
702 358
703 static const struct fs_context_operations pseu 359 static const struct fs_context_operations pseudo_fs_context_ops = {
704 .free = pseudo_fs_free, 360 .free = pseudo_fs_free,
705 .get_tree = pseudo_fs_get_tree, 361 .get_tree = pseudo_fs_get_tree,
706 }; 362 };
707 363
708 /* 364 /*
709 * Common helper for pseudo-filesystems (sockf 365 * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that
710 * will never be mountable) 366 * will never be mountable)
711 */ 367 */
712 struct pseudo_fs_context *init_pseudo(struct f 368 struct pseudo_fs_context *init_pseudo(struct fs_context *fc,
713 unsign 369 unsigned long magic)
714 { 370 {
715 struct pseudo_fs_context *ctx; 371 struct pseudo_fs_context *ctx;
716 372
717 ctx = kzalloc(sizeof(struct pseudo_fs_ 373 ctx = kzalloc(sizeof(struct pseudo_fs_context), GFP_KERNEL);
718 if (likely(ctx)) { 374 if (likely(ctx)) {
719 ctx->magic = magic; 375 ctx->magic = magic;
720 fc->fs_private = ctx; 376 fc->fs_private = ctx;
721 fc->ops = &pseudo_fs_context_o 377 fc->ops = &pseudo_fs_context_ops;
722 fc->sb_flags |= SB_NOUSER; 378 fc->sb_flags |= SB_NOUSER;
723 fc->global = true; 379 fc->global = true;
724 } 380 }
725 return ctx; 381 return ctx;
726 } 382 }
727 EXPORT_SYMBOL(init_pseudo); 383 EXPORT_SYMBOL(init_pseudo);
728 384
729 int simple_open(struct inode *inode, struct fi 385 int simple_open(struct inode *inode, struct file *file)
730 { 386 {
731 if (inode->i_private) 387 if (inode->i_private)
732 file->private_data = inode->i_ 388 file->private_data = inode->i_private;
733 return 0; 389 return 0;
734 } 390 }
735 EXPORT_SYMBOL(simple_open); 391 EXPORT_SYMBOL(simple_open);
736 392
737 int simple_link(struct dentry *old_dentry, str 393 int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
738 { 394 {
739 struct inode *inode = d_inode(old_dent 395 struct inode *inode = d_inode(old_dentry);
740 396
741 inode_set_mtime_to_ts(dir, !! 397 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
742 inode_set_ctime_ <<
743 inc_nlink(inode); 398 inc_nlink(inode);
744 ihold(inode); 399 ihold(inode);
745 dget(dentry); 400 dget(dentry);
746 d_instantiate(dentry, inode); 401 d_instantiate(dentry, inode);
747 return 0; 402 return 0;
748 } 403 }
749 EXPORT_SYMBOL(simple_link); 404 EXPORT_SYMBOL(simple_link);
750 405
751 int simple_empty(struct dentry *dentry) 406 int simple_empty(struct dentry *dentry)
752 { 407 {
753 struct dentry *child; 408 struct dentry *child;
754 int ret = 0; 409 int ret = 0;
755 410
756 spin_lock(&dentry->d_lock); 411 spin_lock(&dentry->d_lock);
757 hlist_for_each_entry(child, &dentry->d !! 412 list_for_each_entry(child, &dentry->d_subdirs, d_child) {
758 spin_lock_nested(&child->d_loc 413 spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
759 if (simple_positive(child)) { 414 if (simple_positive(child)) {
760 spin_unlock(&child->d_ 415 spin_unlock(&child->d_lock);
761 goto out; 416 goto out;
762 } 417 }
763 spin_unlock(&child->d_lock); 418 spin_unlock(&child->d_lock);
764 } 419 }
765 ret = 1; 420 ret = 1;
766 out: 421 out:
767 spin_unlock(&dentry->d_lock); 422 spin_unlock(&dentry->d_lock);
768 return ret; 423 return ret;
769 } 424 }
770 EXPORT_SYMBOL(simple_empty); 425 EXPORT_SYMBOL(simple_empty);
771 426
772 int simple_unlink(struct inode *dir, struct de 427 int simple_unlink(struct inode *dir, struct dentry *dentry)
773 { 428 {
774 struct inode *inode = d_inode(dentry); 429 struct inode *inode = d_inode(dentry);
775 430
776 inode_set_mtime_to_ts(dir, !! 431 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
777 inode_set_ctime_ <<
778 drop_nlink(inode); 432 drop_nlink(inode);
779 dput(dentry); 433 dput(dentry);
780 return 0; 434 return 0;
781 } 435 }
782 EXPORT_SYMBOL(simple_unlink); 436 EXPORT_SYMBOL(simple_unlink);
783 437
784 int simple_rmdir(struct inode *dir, struct den 438 int simple_rmdir(struct inode *dir, struct dentry *dentry)
785 { 439 {
786 if (!simple_empty(dentry)) 440 if (!simple_empty(dentry))
787 return -ENOTEMPTY; 441 return -ENOTEMPTY;
788 442
789 drop_nlink(d_inode(dentry)); 443 drop_nlink(d_inode(dentry));
790 simple_unlink(dir, dentry); 444 simple_unlink(dir, dentry);
791 drop_nlink(dir); 445 drop_nlink(dir);
792 return 0; 446 return 0;
793 } 447 }
794 EXPORT_SYMBOL(simple_rmdir); 448 EXPORT_SYMBOL(simple_rmdir);
795 449
796 /** !! 450 int simple_rename(struct inode *old_dir, struct dentry *old_dentry,
797 * simple_rename_timestamp - update the variou !! 451 struct inode *new_dir, struct dentry *new_dentry,
798 * @old_dir: old parent directory !! 452 unsigned int flags)
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 { <<
810 struct inode *newino = d_inode(new_den <<
811 <<
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 { 453 {
>> 454 struct inode *inode = d_inode(old_dentry);
846 int they_are_dirs = d_is_dir(old_dentr 455 int they_are_dirs = d_is_dir(old_dentry);
847 456
848 if (flags & ~(RENAME_NOREPLACE | RENAM !! 457 if (flags & ~RENAME_NOREPLACE)
849 return -EINVAL; 458 return -EINVAL;
850 459
851 if (flags & RENAME_EXCHANGE) <<
852 return simple_rename_exchange( <<
853 <<
854 if (!simple_empty(new_dentry)) 460 if (!simple_empty(new_dentry))
855 return -ENOTEMPTY; 461 return -ENOTEMPTY;
856 462
857 if (d_really_is_positive(new_dentry)) 463 if (d_really_is_positive(new_dentry)) {
858 simple_unlink(new_dir, new_den 464 simple_unlink(new_dir, new_dentry);
859 if (they_are_dirs) { 465 if (they_are_dirs) {
860 drop_nlink(d_inode(new 466 drop_nlink(d_inode(new_dentry));
861 drop_nlink(old_dir); 467 drop_nlink(old_dir);
862 } 468 }
863 } else if (they_are_dirs) { 469 } else if (they_are_dirs) {
864 drop_nlink(old_dir); 470 drop_nlink(old_dir);
865 inc_nlink(new_dir); 471 inc_nlink(new_dir);
866 } 472 }
867 473
868 simple_rename_timestamp(old_dir, old_d !! 474 old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime =
>> 475 new_dir->i_mtime = inode->i_ctime = current_time(old_dir);
>> 476
869 return 0; 477 return 0;
870 } 478 }
871 EXPORT_SYMBOL(simple_rename); 479 EXPORT_SYMBOL(simple_rename);
872 480
873 /** 481 /**
874 * simple_setattr - setattr for simple filesys 482 * simple_setattr - setattr for simple filesystem
875 * @idmap: idmap of the target mount <<
876 * @dentry: dentry 483 * @dentry: dentry
877 * @iattr: iattr structure 484 * @iattr: iattr structure
878 * 485 *
879 * Returns 0 on success, -error on failure. 486 * Returns 0 on success, -error on failure.
880 * 487 *
881 * simple_setattr is a simple ->setattr implem 488 * simple_setattr is a simple ->setattr implementation without a proper
882 * implementation of size changes. 489 * implementation of size changes.
883 * 490 *
884 * It can either be used for in-memory filesys 491 * It can either be used for in-memory filesystems or special files
885 * on simple regular filesystems. Anything th 492 * on simple regular filesystems. Anything that needs to change on-disk
886 * or wire state on size changes needs its own 493 * or wire state on size changes needs its own setattr method.
887 */ 494 */
888 int simple_setattr(struct mnt_idmap *idmap, st !! 495 int simple_setattr(struct dentry *dentry, struct iattr *iattr)
889 struct iattr *iattr) <<
890 { 496 {
891 struct inode *inode = d_inode(dentry); 497 struct inode *inode = d_inode(dentry);
892 int error; 498 int error;
893 499
894 error = setattr_prepare(idmap, dentry, !! 500 error = setattr_prepare(dentry, iattr);
895 if (error) 501 if (error)
896 return error; 502 return error;
897 503
898 if (iattr->ia_valid & ATTR_SIZE) 504 if (iattr->ia_valid & ATTR_SIZE)
899 truncate_setsize(inode, iattr- 505 truncate_setsize(inode, iattr->ia_size);
900 setattr_copy(idmap, inode, iattr); !! 506 setattr_copy(inode, iattr);
901 mark_inode_dirty(inode); 507 mark_inode_dirty(inode);
902 return 0; 508 return 0;
903 } 509 }
904 EXPORT_SYMBOL(simple_setattr); 510 EXPORT_SYMBOL(simple_setattr);
905 511
906 static int simple_read_folio(struct file *file !! 512 int simple_readpage(struct file *file, struct page *page)
907 { 513 {
908 folio_zero_range(folio, 0, folio_size( !! 514 clear_highpage(page);
909 flush_dcache_folio(folio); !! 515 flush_dcache_page(page);
910 folio_mark_uptodate(folio); !! 516 SetPageUptodate(page);
911 folio_unlock(folio); !! 517 unlock_page(page);
912 return 0; 518 return 0;
913 } 519 }
>> 520 EXPORT_SYMBOL(simple_readpage);
914 521
915 int simple_write_begin(struct file *file, stru 522 int simple_write_begin(struct file *file, struct address_space *mapping,
916 loff_t pos, unsigned l !! 523 loff_t pos, unsigned len, unsigned flags,
917 struct folio **foliop, !! 524 struct page **pagep, void **fsdata)
918 { 525 {
919 struct folio *folio; !! 526 struct page *page;
>> 527 pgoff_t index;
920 528
921 folio = __filemap_get_folio(mapping, p !! 529 index = pos >> PAGE_SHIFT;
922 mapping_gfp_mask(mappi <<
923 if (IS_ERR(folio)) <<
924 return PTR_ERR(folio); <<
925 530
926 *foliop = folio; !! 531 page = grab_cache_page_write_begin(mapping, index, flags);
>> 532 if (!page)
>> 533 return -ENOMEM;
>> 534
>> 535 *pagep = page;
927 536
928 if (!folio_test_uptodate(folio) && (le !! 537 if (!PageUptodate(page) && (len != PAGE_SIZE)) {
929 size_t from = offset_in_folio( !! 538 unsigned from = pos & (PAGE_SIZE - 1);
930 539
931 folio_zero_segments(folio, 0, !! 540 zero_user_segments(page, 0, from, from + len, PAGE_SIZE);
932 from + len, fo <<
933 } 541 }
934 return 0; 542 return 0;
935 } 543 }
936 EXPORT_SYMBOL(simple_write_begin); 544 EXPORT_SYMBOL(simple_write_begin);
937 545
938 /** 546 /**
939 * simple_write_end - .write_end helper for no 547 * simple_write_end - .write_end helper for non-block-device FSes
940 * @file: See .write_end of address_space_oper 548 * @file: See .write_end of address_space_operations
941 * @mapping: " 549 * @mapping: "
942 * @pos: " 550 * @pos: "
943 * @len: " 551 * @len: "
944 * @copied: " 552 * @copied: "
945 * @folio: " !! 553 * @page: "
946 * @fsdata: " 554 * @fsdata: "
947 * 555 *
948 * simple_write_end does the minimum needed fo !! 556 * simple_write_end does the minimum needed for updating a page after writing is
949 * writing is done. It has the same API signat !! 557 * done. It has the same API signature as the .write_end of
950 * address_space_operations vector. So it can 558 * address_space_operations vector. So it can just be set onto .write_end for
951 * FSes that don't need any other processing. 559 * FSes that don't need any other processing. i_mutex is assumed to be held.
952 * Block based filesystems should use generic_ 560 * Block based filesystems should use generic_write_end().
953 * NOTE: Even though i_size might get updated 561 * NOTE: Even though i_size might get updated by this function, mark_inode_dirty
954 * is not called, so a filesystem that actuall 562 * is not called, so a filesystem that actually does store data in .write_inode
955 * should extend on what's done here with a ca 563 * should extend on what's done here with a call to mark_inode_dirty() in the
956 * case that i_size has changed. 564 * case that i_size has changed.
957 * 565 *
958 * Use *ONLY* with simple_read_folio() !! 566 * Use *ONLY* with simple_readpage()
959 */ 567 */
960 static int simple_write_end(struct file *file, !! 568 int simple_write_end(struct file *file, struct address_space *mapping,
961 loff_t pos, unsigned l 569 loff_t pos, unsigned len, unsigned copied,
962 struct folio *folio, v !! 570 struct page *page, void *fsdata)
963 { 571 {
964 struct inode *inode = folio->mapping-> !! 572 struct inode *inode = page->mapping->host;
965 loff_t last_pos = pos + copied; 573 loff_t last_pos = pos + copied;
966 574
967 /* zero the stale part of the folio if !! 575 /* zero the stale part of the page if we did a short copy */
968 if (!folio_test_uptodate(folio)) { !! 576 if (!PageUptodate(page)) {
969 if (copied < len) { 577 if (copied < len) {
970 size_t from = offset_i !! 578 unsigned from = pos & (PAGE_SIZE - 1);
971 579
972 folio_zero_range(folio !! 580 zero_user(page, from + copied, len - copied);
973 } 581 }
974 folio_mark_uptodate(folio); !! 582 SetPageUptodate(page);
975 } 583 }
976 /* 584 /*
977 * No need to use i_size_read() here, 585 * No need to use i_size_read() here, the i_size
978 * cannot change under us because we h 586 * cannot change under us because we hold the i_mutex.
979 */ 587 */
980 if (last_pos > inode->i_size) 588 if (last_pos > inode->i_size)
981 i_size_write(inode, last_pos); 589 i_size_write(inode, last_pos);
982 590
983 folio_mark_dirty(folio); !! 591 set_page_dirty(page);
984 folio_unlock(folio); !! 592 unlock_page(page);
985 folio_put(folio); !! 593 put_page(page);
986 594
987 return copied; 595 return copied;
988 } 596 }
989 !! 597 EXPORT_SYMBOL(simple_write_end);
990 /* <<
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 598
1001 /* 599 /*
1002 * the inodes created here are not hashed. If 600 * the inodes created here are not hashed. If you use iunique to generate
1003 * unique inode values later for this filesys 601 * unique inode values later for this filesystem, then you must take care
1004 * to pass it an appropriate max_reserved val 602 * to pass it an appropriate max_reserved value to avoid collisions.
1005 */ 603 */
1006 int simple_fill_super(struct super_block *s, 604 int simple_fill_super(struct super_block *s, unsigned long magic,
1007 const struct tree_descr 605 const struct tree_descr *files)
1008 { 606 {
1009 struct inode *inode; 607 struct inode *inode;
>> 608 struct dentry *root;
1010 struct dentry *dentry; 609 struct dentry *dentry;
1011 int i; 610 int i;
1012 611
1013 s->s_blocksize = PAGE_SIZE; 612 s->s_blocksize = PAGE_SIZE;
1014 s->s_blocksize_bits = PAGE_SHIFT; 613 s->s_blocksize_bits = PAGE_SHIFT;
1015 s->s_magic = magic; 614 s->s_magic = magic;
1016 s->s_op = &simple_super_operations; 615 s->s_op = &simple_super_operations;
1017 s->s_time_gran = 1; 616 s->s_time_gran = 1;
1018 617
1019 inode = new_inode(s); 618 inode = new_inode(s);
1020 if (!inode) 619 if (!inode)
1021 return -ENOMEM; 620 return -ENOMEM;
1022 /* 621 /*
1023 * because the root inode is 1, the f 622 * because the root inode is 1, the files array must not contain an
1024 * entry at index 1 623 * entry at index 1
1025 */ 624 */
1026 inode->i_ino = 1; 625 inode->i_ino = 1;
1027 inode->i_mode = S_IFDIR | 0755; 626 inode->i_mode = S_IFDIR | 0755;
1028 simple_inode_init_ts(inode); !! 627 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
1029 inode->i_op = &simple_dir_inode_opera 628 inode->i_op = &simple_dir_inode_operations;
1030 inode->i_fop = &simple_dir_operations 629 inode->i_fop = &simple_dir_operations;
1031 set_nlink(inode, 2); 630 set_nlink(inode, 2);
1032 s->s_root = d_make_root(inode); !! 631 root = d_make_root(inode);
1033 if (!s->s_root) !! 632 if (!root)
1034 return -ENOMEM; 633 return -ENOMEM;
1035 for (i = 0; !files->name || files->na 634 for (i = 0; !files->name || files->name[0]; i++, files++) {
1036 if (!files->name) 635 if (!files->name)
1037 continue; 636 continue;
1038 637
1039 /* warn if it tries to confli 638 /* warn if it tries to conflict with the root inode */
1040 if (unlikely(i == 1)) 639 if (unlikely(i == 1))
1041 printk(KERN_WARNING " 640 printk(KERN_WARNING "%s: %s passed in a files array"
1042 "with an inde 641 "with an index of 1!\n", __func__,
1043 s->s_type->na 642 s->s_type->name);
1044 643
1045 dentry = d_alloc_name(s->s_ro !! 644 dentry = d_alloc_name(root, files->name);
1046 if (!dentry) 645 if (!dentry)
1047 return -ENOMEM; !! 646 goto out;
1048 inode = new_inode(s); 647 inode = new_inode(s);
1049 if (!inode) { 648 if (!inode) {
1050 dput(dentry); 649 dput(dentry);
1051 return -ENOMEM; !! 650 goto out;
1052 } 651 }
1053 inode->i_mode = S_IFREG | fil 652 inode->i_mode = S_IFREG | files->mode;
1054 simple_inode_init_ts(inode); !! 653 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
1055 inode->i_fop = files->ops; 654 inode->i_fop = files->ops;
1056 inode->i_ino = i; 655 inode->i_ino = i;
1057 d_add(dentry, inode); 656 d_add(dentry, inode);
1058 } 657 }
>> 658 s->s_root = root;
1059 return 0; 659 return 0;
>> 660 out:
>> 661 d_genocide(root);
>> 662 shrink_dcache_parent(root);
>> 663 dput(root);
>> 664 return -ENOMEM;
1060 } 665 }
1061 EXPORT_SYMBOL(simple_fill_super); 666 EXPORT_SYMBOL(simple_fill_super);
1062 667
1063 static DEFINE_SPINLOCK(pin_fs_lock); 668 static DEFINE_SPINLOCK(pin_fs_lock);
1064 669
1065 int simple_pin_fs(struct file_system_type *ty 670 int simple_pin_fs(struct file_system_type *type, struct vfsmount **mount, int *count)
1066 { 671 {
1067 struct vfsmount *mnt = NULL; 672 struct vfsmount *mnt = NULL;
1068 spin_lock(&pin_fs_lock); 673 spin_lock(&pin_fs_lock);
1069 if (unlikely(!*mount)) { 674 if (unlikely(!*mount)) {
1070 spin_unlock(&pin_fs_lock); 675 spin_unlock(&pin_fs_lock);
1071 mnt = vfs_kern_mount(type, SB 676 mnt = vfs_kern_mount(type, SB_KERNMOUNT, type->name, NULL);
1072 if (IS_ERR(mnt)) 677 if (IS_ERR(mnt))
1073 return PTR_ERR(mnt); 678 return PTR_ERR(mnt);
1074 spin_lock(&pin_fs_lock); 679 spin_lock(&pin_fs_lock);
1075 if (!*mount) 680 if (!*mount)
1076 *mount = mnt; 681 *mount = mnt;
1077 } 682 }
1078 mntget(*mount); 683 mntget(*mount);
1079 ++*count; 684 ++*count;
1080 spin_unlock(&pin_fs_lock); 685 spin_unlock(&pin_fs_lock);
1081 mntput(mnt); 686 mntput(mnt);
1082 return 0; 687 return 0;
1083 } 688 }
1084 EXPORT_SYMBOL(simple_pin_fs); 689 EXPORT_SYMBOL(simple_pin_fs);
1085 690
1086 void simple_release_fs(struct vfsmount **moun 691 void simple_release_fs(struct vfsmount **mount, int *count)
1087 { 692 {
1088 struct vfsmount *mnt; 693 struct vfsmount *mnt;
1089 spin_lock(&pin_fs_lock); 694 spin_lock(&pin_fs_lock);
1090 mnt = *mount; 695 mnt = *mount;
1091 if (!--*count) 696 if (!--*count)
1092 *mount = NULL; 697 *mount = NULL;
1093 spin_unlock(&pin_fs_lock); 698 spin_unlock(&pin_fs_lock);
1094 mntput(mnt); 699 mntput(mnt);
1095 } 700 }
1096 EXPORT_SYMBOL(simple_release_fs); 701 EXPORT_SYMBOL(simple_release_fs);
1097 702
1098 /** 703 /**
1099 * simple_read_from_buffer - copy data from t 704 * simple_read_from_buffer - copy data from the buffer to user space
1100 * @to: the user space buffer to read to 705 * @to: the user space buffer to read to
1101 * @count: the maximum number of bytes to rea 706 * @count: the maximum number of bytes to read
1102 * @ppos: the current position in the buffer 707 * @ppos: the current position in the buffer
1103 * @from: the buffer to read from 708 * @from: the buffer to read from
1104 * @available: the size of the buffer 709 * @available: the size of the buffer
1105 * 710 *
1106 * The simple_read_from_buffer() function rea 711 * The simple_read_from_buffer() function reads up to @count bytes from the
1107 * buffer @from at offset @ppos into the user 712 * buffer @from at offset @ppos into the user space address starting at @to.
1108 * 713 *
1109 * On success, the number of bytes read is re 714 * On success, the number of bytes read is returned and the offset @ppos is
1110 * advanced by this number, or negative value 715 * advanced by this number, or negative value is returned on error.
1111 **/ 716 **/
1112 ssize_t simple_read_from_buffer(void __user * 717 ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
1113 const void *f 718 const void *from, size_t available)
1114 { 719 {
1115 loff_t pos = *ppos; 720 loff_t pos = *ppos;
1116 size_t ret; 721 size_t ret;
1117 722
1118 if (pos < 0) 723 if (pos < 0)
1119 return -EINVAL; 724 return -EINVAL;
1120 if (pos >= available || !count) 725 if (pos >= available || !count)
1121 return 0; 726 return 0;
1122 if (count > available - pos) 727 if (count > available - pos)
1123 count = available - pos; 728 count = available - pos;
1124 ret = copy_to_user(to, from + pos, co 729 ret = copy_to_user(to, from + pos, count);
1125 if (ret == count) 730 if (ret == count)
1126 return -EFAULT; 731 return -EFAULT;
1127 count -= ret; 732 count -= ret;
1128 *ppos = pos + count; 733 *ppos = pos + count;
1129 return count; 734 return count;
1130 } 735 }
1131 EXPORT_SYMBOL(simple_read_from_buffer); 736 EXPORT_SYMBOL(simple_read_from_buffer);
1132 737
1133 /** 738 /**
1134 * simple_write_to_buffer - copy data from us 739 * simple_write_to_buffer - copy data from user space to the buffer
1135 * @to: the buffer to write to 740 * @to: the buffer to write to
1136 * @available: the size of the buffer 741 * @available: the size of the buffer
1137 * @ppos: the current position in the buffer 742 * @ppos: the current position in the buffer
1138 * @from: the user space buffer to read from 743 * @from: the user space buffer to read from
1139 * @count: the maximum number of bytes to rea 744 * @count: the maximum number of bytes to read
1140 * 745 *
1141 * The simple_write_to_buffer() function read 746 * The simple_write_to_buffer() function reads up to @count bytes from the user
1142 * space address starting at @from into the b 747 * space address starting at @from into the buffer @to at offset @ppos.
1143 * 748 *
1144 * On success, the number of bytes written is 749 * On success, the number of bytes written is returned and the offset @ppos is
1145 * advanced by this number, or negative value 750 * advanced by this number, or negative value is returned on error.
1146 **/ 751 **/
1147 ssize_t simple_write_to_buffer(void *to, size 752 ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
1148 const void __user *from, size 753 const void __user *from, size_t count)
1149 { 754 {
1150 loff_t pos = *ppos; 755 loff_t pos = *ppos;
1151 size_t res; 756 size_t res;
1152 757
1153 if (pos < 0) 758 if (pos < 0)
1154 return -EINVAL; 759 return -EINVAL;
1155 if (pos >= available || !count) 760 if (pos >= available || !count)
1156 return 0; 761 return 0;
1157 if (count > available - pos) 762 if (count > available - pos)
1158 count = available - pos; 763 count = available - pos;
1159 res = copy_from_user(to + pos, from, 764 res = copy_from_user(to + pos, from, count);
1160 if (res == count) 765 if (res == count)
1161 return -EFAULT; 766 return -EFAULT;
1162 count -= res; 767 count -= res;
1163 *ppos = pos + count; 768 *ppos = pos + count;
1164 return count; 769 return count;
1165 } 770 }
1166 EXPORT_SYMBOL(simple_write_to_buffer); 771 EXPORT_SYMBOL(simple_write_to_buffer);
1167 772
1168 /** 773 /**
1169 * memory_read_from_buffer - copy data from t 774 * memory_read_from_buffer - copy data from the buffer
1170 * @to: the kernel space buffer to read to 775 * @to: the kernel space buffer to read to
1171 * @count: the maximum number of bytes to rea 776 * @count: the maximum number of bytes to read
1172 * @ppos: the current position in the buffer 777 * @ppos: the current position in the buffer
1173 * @from: the buffer to read from 778 * @from: the buffer to read from
1174 * @available: the size of the buffer 779 * @available: the size of the buffer
1175 * 780 *
1176 * The memory_read_from_buffer() function rea 781 * The memory_read_from_buffer() function reads up to @count bytes from the
1177 * buffer @from at offset @ppos into the kern 782 * buffer @from at offset @ppos into the kernel space address starting at @to.
1178 * 783 *
1179 * On success, the number of bytes read is re 784 * On success, the number of bytes read is returned and the offset @ppos is
1180 * advanced by this number, or negative value 785 * advanced by this number, or negative value is returned on error.
1181 **/ 786 **/
1182 ssize_t memory_read_from_buffer(void *to, siz 787 ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
1183 const void *f 788 const void *from, size_t available)
1184 { 789 {
1185 loff_t pos = *ppos; 790 loff_t pos = *ppos;
1186 791
1187 if (pos < 0) 792 if (pos < 0)
1188 return -EINVAL; 793 return -EINVAL;
1189 if (pos >= available) 794 if (pos >= available)
1190 return 0; 795 return 0;
1191 if (count > available - pos) 796 if (count > available - pos)
1192 count = available - pos; 797 count = available - pos;
1193 memcpy(to, from + pos, count); 798 memcpy(to, from + pos, count);
1194 *ppos = pos + count; 799 *ppos = pos + count;
1195 800
1196 return count; 801 return count;
1197 } 802 }
1198 EXPORT_SYMBOL(memory_read_from_buffer); 803 EXPORT_SYMBOL(memory_read_from_buffer);
1199 804
1200 /* 805 /*
1201 * Transaction based IO. 806 * Transaction based IO.
1202 * The file expects a single write which trig 807 * The file expects a single write which triggers the transaction, and then
1203 * possibly a read which collects the result 808 * possibly a read which collects the result - which is stored in a
1204 * file-local buffer. 809 * file-local buffer.
1205 */ 810 */
1206 811
1207 void simple_transaction_set(struct file *file 812 void simple_transaction_set(struct file *file, size_t n)
1208 { 813 {
1209 struct simple_transaction_argresp *ar 814 struct simple_transaction_argresp *ar = file->private_data;
1210 815
1211 BUG_ON(n > SIMPLE_TRANSACTION_LIMIT); 816 BUG_ON(n > SIMPLE_TRANSACTION_LIMIT);
1212 817
1213 /* 818 /*
1214 * The barrier ensures that ar->size 819 * The barrier ensures that ar->size will really remain zero until
1215 * ar->data is ready for reading. 820 * ar->data is ready for reading.
1216 */ 821 */
1217 smp_mb(); 822 smp_mb();
1218 ar->size = n; 823 ar->size = n;
1219 } 824 }
1220 EXPORT_SYMBOL(simple_transaction_set); 825 EXPORT_SYMBOL(simple_transaction_set);
1221 826
1222 char *simple_transaction_get(struct file *fil 827 char *simple_transaction_get(struct file *file, const char __user *buf, size_t size)
1223 { 828 {
1224 struct simple_transaction_argresp *ar 829 struct simple_transaction_argresp *ar;
1225 static DEFINE_SPINLOCK(simple_transac 830 static DEFINE_SPINLOCK(simple_transaction_lock);
1226 831
1227 if (size > SIMPLE_TRANSACTION_LIMIT - 832 if (size > SIMPLE_TRANSACTION_LIMIT - 1)
1228 return ERR_PTR(-EFBIG); 833 return ERR_PTR(-EFBIG);
1229 834
1230 ar = (struct simple_transaction_argre 835 ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL);
1231 if (!ar) 836 if (!ar)
1232 return ERR_PTR(-ENOMEM); 837 return ERR_PTR(-ENOMEM);
1233 838
1234 spin_lock(&simple_transaction_lock); 839 spin_lock(&simple_transaction_lock);
1235 840
1236 /* only one write allowed per open */ 841 /* only one write allowed per open */
1237 if (file->private_data) { 842 if (file->private_data) {
1238 spin_unlock(&simple_transacti 843 spin_unlock(&simple_transaction_lock);
1239 free_page((unsigned long)ar); 844 free_page((unsigned long)ar);
1240 return ERR_PTR(-EBUSY); 845 return ERR_PTR(-EBUSY);
1241 } 846 }
1242 847
1243 file->private_data = ar; 848 file->private_data = ar;
1244 849
1245 spin_unlock(&simple_transaction_lock) 850 spin_unlock(&simple_transaction_lock);
1246 851
1247 if (copy_from_user(ar->data, buf, siz 852 if (copy_from_user(ar->data, buf, size))
1248 return ERR_PTR(-EFAULT); 853 return ERR_PTR(-EFAULT);
1249 854
1250 return ar->data; 855 return ar->data;
1251 } 856 }
1252 EXPORT_SYMBOL(simple_transaction_get); 857 EXPORT_SYMBOL(simple_transaction_get);
1253 858
1254 ssize_t simple_transaction_read(struct file * 859 ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
1255 { 860 {
1256 struct simple_transaction_argresp *ar 861 struct simple_transaction_argresp *ar = file->private_data;
1257 862
1258 if (!ar) 863 if (!ar)
1259 return 0; 864 return 0;
1260 return simple_read_from_buffer(buf, s 865 return simple_read_from_buffer(buf, size, pos, ar->data, ar->size);
1261 } 866 }
1262 EXPORT_SYMBOL(simple_transaction_read); 867 EXPORT_SYMBOL(simple_transaction_read);
1263 868
1264 int simple_transaction_release(struct inode * 869 int simple_transaction_release(struct inode *inode, struct file *file)
1265 { 870 {
1266 free_page((unsigned long)file->privat 871 free_page((unsigned long)file->private_data);
1267 return 0; 872 return 0;
1268 } 873 }
1269 EXPORT_SYMBOL(simple_transaction_release); 874 EXPORT_SYMBOL(simple_transaction_release);
1270 875
1271 /* Simple attribute files */ 876 /* Simple attribute files */
1272 877
1273 struct simple_attr { 878 struct simple_attr {
1274 int (*get)(void *, u64 *); 879 int (*get)(void *, u64 *);
1275 int (*set)(void *, u64); 880 int (*set)(void *, u64);
1276 char get_buf[24]; /* enough to 881 char get_buf[24]; /* enough to store a u64 and "\n\0" */
1277 char set_buf[24]; 882 char set_buf[24];
1278 void *data; 883 void *data;
1279 const char *fmt; /* format for 884 const char *fmt; /* format for read operation */
1280 struct mutex mutex; /* protects a 885 struct mutex mutex; /* protects access to these buffers */
1281 }; 886 };
1282 887
1283 /* simple_attr_open is called by an actual at 888 /* simple_attr_open is called by an actual attribute open file operation
1284 * to set the attribute specific access opera 889 * to set the attribute specific access operations. */
1285 int simple_attr_open(struct inode *inode, str 890 int simple_attr_open(struct inode *inode, struct file *file,
1286 int (*get)(void *, u64 * 891 int (*get)(void *, u64 *), int (*set)(void *, u64),
1287 const char *fmt) 892 const char *fmt)
1288 { 893 {
1289 struct simple_attr *attr; 894 struct simple_attr *attr;
1290 895
1291 attr = kzalloc(sizeof(*attr), GFP_KER 896 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
1292 if (!attr) 897 if (!attr)
1293 return -ENOMEM; 898 return -ENOMEM;
1294 899
1295 attr->get = get; 900 attr->get = get;
1296 attr->set = set; 901 attr->set = set;
1297 attr->data = inode->i_private; 902 attr->data = inode->i_private;
1298 attr->fmt = fmt; 903 attr->fmt = fmt;
1299 mutex_init(&attr->mutex); 904 mutex_init(&attr->mutex);
1300 905
1301 file->private_data = attr; 906 file->private_data = attr;
1302 907
1303 return nonseekable_open(inode, file); 908 return nonseekable_open(inode, file);
1304 } 909 }
1305 EXPORT_SYMBOL_GPL(simple_attr_open); 910 EXPORT_SYMBOL_GPL(simple_attr_open);
1306 911
1307 int simple_attr_release(struct inode *inode, 912 int simple_attr_release(struct inode *inode, struct file *file)
1308 { 913 {
1309 kfree(file->private_data); 914 kfree(file->private_data);
1310 return 0; 915 return 0;
1311 } 916 }
1312 EXPORT_SYMBOL_GPL(simple_attr_release); /* GP 917 EXPORT_SYMBOL_GPL(simple_attr_release); /* GPL-only? This? Really? */
1313 918
1314 /* read from the buffer that is filled with t 919 /* read from the buffer that is filled with the get function */
1315 ssize_t simple_attr_read(struct file *file, c 920 ssize_t simple_attr_read(struct file *file, char __user *buf,
1316 size_t len, loff_t * 921 size_t len, loff_t *ppos)
1317 { 922 {
1318 struct simple_attr *attr; 923 struct simple_attr *attr;
1319 size_t size; 924 size_t size;
1320 ssize_t ret; 925 ssize_t ret;
1321 926
1322 attr = file->private_data; 927 attr = file->private_data;
1323 928
1324 if (!attr->get) 929 if (!attr->get)
1325 return -EACCES; 930 return -EACCES;
1326 931
1327 ret = mutex_lock_interruptible(&attr- 932 ret = mutex_lock_interruptible(&attr->mutex);
1328 if (ret) 933 if (ret)
1329 return ret; 934 return ret;
1330 935
1331 if (*ppos && attr->get_buf[0]) { 936 if (*ppos && attr->get_buf[0]) {
1332 /* continued read */ 937 /* continued read */
1333 size = strlen(attr->get_buf); 938 size = strlen(attr->get_buf);
1334 } else { 939 } else {
1335 /* first read */ 940 /* first read */
1336 u64 val; 941 u64 val;
1337 ret = attr->get(attr->data, & 942 ret = attr->get(attr->data, &val);
1338 if (ret) 943 if (ret)
1339 goto out; 944 goto out;
1340 945
1341 size = scnprintf(attr->get_bu 946 size = scnprintf(attr->get_buf, sizeof(attr->get_buf),
1342 attr->fmt, ( 947 attr->fmt, (unsigned long long)val);
1343 } 948 }
1344 949
1345 ret = simple_read_from_buffer(buf, le 950 ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size);
1346 out: 951 out:
1347 mutex_unlock(&attr->mutex); 952 mutex_unlock(&attr->mutex);
1348 return ret; 953 return ret;
1349 } 954 }
1350 EXPORT_SYMBOL_GPL(simple_attr_read); 955 EXPORT_SYMBOL_GPL(simple_attr_read);
1351 956
1352 /* interpret the buffer as a number to call t 957 /* interpret the buffer as a number to call the set function with */
1353 static ssize_t simple_attr_write_xsigned(stru 958 static ssize_t simple_attr_write_xsigned(struct file *file, const char __user *buf,
1354 size_t len, loff_t 959 size_t len, loff_t *ppos, bool is_signed)
1355 { 960 {
1356 struct simple_attr *attr; 961 struct simple_attr *attr;
1357 unsigned long long val; 962 unsigned long long val;
1358 size_t size; 963 size_t size;
1359 ssize_t ret; 964 ssize_t ret;
1360 965
1361 attr = file->private_data; 966 attr = file->private_data;
1362 if (!attr->set) 967 if (!attr->set)
1363 return -EACCES; 968 return -EACCES;
1364 969
1365 ret = mutex_lock_interruptible(&attr- 970 ret = mutex_lock_interruptible(&attr->mutex);
1366 if (ret) 971 if (ret)
1367 return ret; 972 return ret;
1368 973
1369 ret = -EFAULT; 974 ret = -EFAULT;
1370 size = min(sizeof(attr->set_buf) - 1, 975 size = min(sizeof(attr->set_buf) - 1, len);
1371 if (copy_from_user(attr->set_buf, buf 976 if (copy_from_user(attr->set_buf, buf, size))
1372 goto out; 977 goto out;
1373 978
1374 attr->set_buf[size] = '\0'; 979 attr->set_buf[size] = '\0';
1375 if (is_signed) 980 if (is_signed)
1376 ret = kstrtoll(attr->set_buf, 981 ret = kstrtoll(attr->set_buf, 0, &val);
1377 else 982 else
1378 ret = kstrtoull(attr->set_buf 983 ret = kstrtoull(attr->set_buf, 0, &val);
1379 if (ret) 984 if (ret)
1380 goto out; 985 goto out;
1381 ret = attr->set(attr->data, val); 986 ret = attr->set(attr->data, val);
1382 if (ret == 0) 987 if (ret == 0)
1383 ret = len; /* on success, cla 988 ret = len; /* on success, claim we got the whole input */
1384 out: 989 out:
1385 mutex_unlock(&attr->mutex); 990 mutex_unlock(&attr->mutex);
1386 return ret; 991 return ret;
1387 } 992 }
1388 993
1389 ssize_t simple_attr_write(struct file *file, 994 ssize_t simple_attr_write(struct file *file, const char __user *buf,
1390 size_t len, loff_t 995 size_t len, loff_t *ppos)
1391 { 996 {
1392 return simple_attr_write_xsigned(file 997 return simple_attr_write_xsigned(file, buf, len, ppos, false);
1393 } 998 }
1394 EXPORT_SYMBOL_GPL(simple_attr_write); 999 EXPORT_SYMBOL_GPL(simple_attr_write);
1395 1000
1396 ssize_t simple_attr_write_signed(struct file 1001 ssize_t simple_attr_write_signed(struct file *file, const char __user *buf,
1397 size_t len, loff_t 1002 size_t len, loff_t *ppos)
1398 { 1003 {
1399 return simple_attr_write_xsigned(file 1004 return simple_attr_write_xsigned(file, buf, len, ppos, true);
1400 } 1005 }
1401 EXPORT_SYMBOL_GPL(simple_attr_write_signed); 1006 EXPORT_SYMBOL_GPL(simple_attr_write_signed);
1402 1007
1403 /** 1008 /**
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 /** <<
1445 * generic_fh_to_dentry - generic helper for 1009 * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation
1446 * @sb: filesystem to do the file han 1010 * @sb: filesystem to do the file handle conversion on
1447 * @fid: file handle to convert 1011 * @fid: file handle to convert
1448 * @fh_len: length of the file handle in 1012 * @fh_len: length of the file handle in bytes
1449 * @fh_type: type of file handle 1013 * @fh_type: type of file handle
1450 * @get_inode: filesystem callback to retrie 1014 * @get_inode: filesystem callback to retrieve inode
1451 * 1015 *
1452 * This function decodes @fid as long as it h 1016 * This function decodes @fid as long as it has one of the well-known
1453 * Linux filehandle types and calls @get_inod 1017 * Linux filehandle types and calls @get_inode on it to retrieve the
1454 * inode for the object specified in the file 1018 * inode for the object specified in the file handle.
1455 */ 1019 */
1456 struct dentry *generic_fh_to_dentry(struct su 1020 struct dentry *generic_fh_to_dentry(struct super_block *sb, struct fid *fid,
1457 int fh_len, int fh_type, stru 1021 int fh_len, int fh_type, struct inode *(*get_inode)
1458 (struct super_block * 1022 (struct super_block *sb, u64 ino, u32 gen))
1459 { 1023 {
1460 struct inode *inode = NULL; 1024 struct inode *inode = NULL;
1461 1025
1462 if (fh_len < 2) 1026 if (fh_len < 2)
1463 return NULL; 1027 return NULL;
1464 1028
1465 switch (fh_type) { 1029 switch (fh_type) {
1466 case FILEID_INO32_GEN: 1030 case FILEID_INO32_GEN:
1467 case FILEID_INO32_GEN_PARENT: 1031 case FILEID_INO32_GEN_PARENT:
1468 inode = get_inode(sb, fid->i3 1032 inode = get_inode(sb, fid->i32.ino, fid->i32.gen);
1469 break; 1033 break;
1470 } 1034 }
1471 1035
1472 return d_obtain_alias(inode); 1036 return d_obtain_alias(inode);
1473 } 1037 }
1474 EXPORT_SYMBOL_GPL(generic_fh_to_dentry); 1038 EXPORT_SYMBOL_GPL(generic_fh_to_dentry);
1475 1039
1476 /** 1040 /**
1477 * generic_fh_to_parent - generic helper for 1041 * generic_fh_to_parent - generic helper for the fh_to_parent export operation
1478 * @sb: filesystem to do the file han 1042 * @sb: filesystem to do the file handle conversion on
1479 * @fid: file handle to convert 1043 * @fid: file handle to convert
1480 * @fh_len: length of the file handle in 1044 * @fh_len: length of the file handle in bytes
1481 * @fh_type: type of file handle 1045 * @fh_type: type of file handle
1482 * @get_inode: filesystem callback to retrie 1046 * @get_inode: filesystem callback to retrieve inode
1483 * 1047 *
1484 * This function decodes @fid as long as it h 1048 * This function decodes @fid as long as it has one of the well-known
1485 * Linux filehandle types and calls @get_inod 1049 * Linux filehandle types and calls @get_inode on it to retrieve the
1486 * inode for the _parent_ object specified in 1050 * inode for the _parent_ object specified in the file handle if it
1487 * is specified in the file handle, or NULL o 1051 * is specified in the file handle, or NULL otherwise.
1488 */ 1052 */
1489 struct dentry *generic_fh_to_parent(struct su 1053 struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid,
1490 int fh_len, int fh_type, stru 1054 int fh_len, int fh_type, struct inode *(*get_inode)
1491 (struct super_block * 1055 (struct super_block *sb, u64 ino, u32 gen))
1492 { 1056 {
1493 struct inode *inode = NULL; 1057 struct inode *inode = NULL;
1494 1058
1495 if (fh_len <= 2) 1059 if (fh_len <= 2)
1496 return NULL; 1060 return NULL;
1497 1061
1498 switch (fh_type) { 1062 switch (fh_type) {
1499 case FILEID_INO32_GEN_PARENT: 1063 case FILEID_INO32_GEN_PARENT:
1500 inode = get_inode(sb, fid->i3 1064 inode = get_inode(sb, fid->i32.parent_ino,
1501 (fh_len > 3 1065 (fh_len > 3 ? fid->i32.parent_gen : 0));
1502 break; 1066 break;
1503 } 1067 }
1504 1068
1505 return d_obtain_alias(inode); 1069 return d_obtain_alias(inode);
1506 } 1070 }
1507 EXPORT_SYMBOL_GPL(generic_fh_to_parent); 1071 EXPORT_SYMBOL_GPL(generic_fh_to_parent);
1508 1072
1509 /** 1073 /**
1510 * __generic_file_fsync - generic fsync imple 1074 * __generic_file_fsync - generic fsync implementation for simple filesystems
1511 * 1075 *
1512 * @file: file to synchronize 1076 * @file: file to synchronize
1513 * @start: start offset in bytes 1077 * @start: start offset in bytes
1514 * @end: end offset in bytes (inclusiv 1078 * @end: end offset in bytes (inclusive)
1515 * @datasync: only synchronize essential me 1079 * @datasync: only synchronize essential metadata if true
1516 * 1080 *
1517 * This is a generic implementation of the fs 1081 * This is a generic implementation of the fsync method for simple
1518 * filesystems which track all non-inode meta 1082 * filesystems which track all non-inode metadata in the buffers list
1519 * hanging off the address_space structure. 1083 * hanging off the address_space structure.
1520 */ 1084 */
1521 int __generic_file_fsync(struct file *file, l 1085 int __generic_file_fsync(struct file *file, loff_t start, loff_t end,
1522 int datasync 1086 int datasync)
1523 { 1087 {
1524 struct inode *inode = file->f_mapping 1088 struct inode *inode = file->f_mapping->host;
1525 int err; 1089 int err;
1526 int ret; 1090 int ret;
1527 1091
1528 err = file_write_and_wait_range(file, 1092 err = file_write_and_wait_range(file, start, end);
1529 if (err) 1093 if (err)
1530 return err; 1094 return err;
1531 1095
1532 inode_lock(inode); 1096 inode_lock(inode);
1533 ret = sync_mapping_buffers(inode->i_m 1097 ret = sync_mapping_buffers(inode->i_mapping);
1534 if (!(inode->i_state & I_DIRTY_ALL)) 1098 if (!(inode->i_state & I_DIRTY_ALL))
1535 goto out; 1099 goto out;
1536 if (datasync && !(inode->i_state & I_ 1100 if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
1537 goto out; 1101 goto out;
1538 1102
1539 err = sync_inode_metadata(inode, 1); 1103 err = sync_inode_metadata(inode, 1);
1540 if (ret == 0) 1104 if (ret == 0)
1541 ret = err; 1105 ret = err;
1542 1106
1543 out: 1107 out:
1544 inode_unlock(inode); 1108 inode_unlock(inode);
1545 /* check and advance again to catch e 1109 /* check and advance again to catch errors after syncing out buffers */
1546 err = file_check_and_advance_wb_err(f 1110 err = file_check_and_advance_wb_err(file);
1547 if (ret == 0) 1111 if (ret == 0)
1548 ret = err; 1112 ret = err;
1549 return ret; 1113 return ret;
1550 } 1114 }
1551 EXPORT_SYMBOL(__generic_file_fsync); 1115 EXPORT_SYMBOL(__generic_file_fsync);
1552 1116
1553 /** 1117 /**
1554 * generic_file_fsync - generic fsync impleme 1118 * generic_file_fsync - generic fsync implementation for simple filesystems
1555 * with flush 1119 * with flush
1556 * @file: file to synchronize 1120 * @file: file to synchronize
1557 * @start: start offset in bytes 1121 * @start: start offset in bytes
1558 * @end: end offset in bytes (inclusiv 1122 * @end: end offset in bytes (inclusive)
1559 * @datasync: only synchronize essential me 1123 * @datasync: only synchronize essential metadata if true
1560 * 1124 *
1561 */ 1125 */
1562 1126
1563 int generic_file_fsync(struct file *file, lof 1127 int generic_file_fsync(struct file *file, loff_t start, loff_t end,
1564 int datasync) 1128 int datasync)
1565 { 1129 {
1566 struct inode *inode = file->f_mapping 1130 struct inode *inode = file->f_mapping->host;
1567 int err; 1131 int err;
1568 1132
1569 err = __generic_file_fsync(file, star 1133 err = __generic_file_fsync(file, start, end, datasync);
1570 if (err) 1134 if (err)
1571 return err; 1135 return err;
1572 return blkdev_issue_flush(inode->i_sb !! 1136 return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL);
1573 } 1137 }
1574 EXPORT_SYMBOL(generic_file_fsync); 1138 EXPORT_SYMBOL(generic_file_fsync);
1575 1139
1576 /** 1140 /**
1577 * generic_check_addressable - Check addressa 1141 * generic_check_addressable - Check addressability of file system
1578 * @blocksize_bits: log of file system bl 1142 * @blocksize_bits: log of file system block size
1579 * @num_blocks: number of blocks in f 1143 * @num_blocks: number of blocks in file system
1580 * 1144 *
1581 * Determine whether a file system with @num_ 1145 * Determine whether a file system with @num_blocks blocks (and a
1582 * block size of 2**@blocksize_bits) is addre 1146 * block size of 2**@blocksize_bits) is addressable by the sector_t
1583 * and page cache of the system. Return 0 if 1147 * and page cache of the system. Return 0 if so and -EFBIG otherwise.
1584 */ 1148 */
1585 int generic_check_addressable(unsigned blocks 1149 int generic_check_addressable(unsigned blocksize_bits, u64 num_blocks)
1586 { 1150 {
1587 u64 last_fs_block = num_blocks - 1; 1151 u64 last_fs_block = num_blocks - 1;
1588 u64 last_fs_page = 1152 u64 last_fs_page =
1589 last_fs_block >> (PAGE_SHIFT 1153 last_fs_block >> (PAGE_SHIFT - blocksize_bits);
1590 1154
1591 if (unlikely(num_blocks == 0)) 1155 if (unlikely(num_blocks == 0))
1592 return 0; 1156 return 0;
1593 1157
1594 if ((blocksize_bits < 9) || (blocksiz 1158 if ((blocksize_bits < 9) || (blocksize_bits > PAGE_SHIFT))
1595 return -EINVAL; 1159 return -EINVAL;
1596 1160
1597 if ((last_fs_block > (sector_t)(~0ULL 1161 if ((last_fs_block > (sector_t)(~0ULL) >> (blocksize_bits - 9)) ||
1598 (last_fs_page > (pgoff_t)(~0ULL)) 1162 (last_fs_page > (pgoff_t)(~0ULL))) {
1599 return -EFBIG; 1163 return -EFBIG;
1600 } 1164 }
1601 return 0; 1165 return 0;
1602 } 1166 }
1603 EXPORT_SYMBOL(generic_check_addressable); 1167 EXPORT_SYMBOL(generic_check_addressable);
1604 1168
1605 /* 1169 /*
1606 * No-op implementation of ->fsync for in-mem 1170 * No-op implementation of ->fsync for in-memory filesystems.
1607 */ 1171 */
1608 int noop_fsync(struct file *file, loff_t star 1172 int noop_fsync(struct file *file, loff_t start, loff_t end, int datasync)
1609 { 1173 {
1610 return 0; 1174 return 0;
1611 } 1175 }
1612 EXPORT_SYMBOL(noop_fsync); 1176 EXPORT_SYMBOL(noop_fsync);
1613 1177
>> 1178 int noop_set_page_dirty(struct page *page)
>> 1179 {
>> 1180 /*
>> 1181 * Unlike __set_page_dirty_no_writeback that handles dirty page
>> 1182 * tracking in the page object, dax does all dirty tracking in
>> 1183 * the inode address_space in response to mkwrite faults. In the
>> 1184 * dax case we only need to worry about potentially dirty CPU
>> 1185 * caches, not dirty page cache pages to write back.
>> 1186 *
>> 1187 * This callback is defined to prevent fallback to
>> 1188 * __set_page_dirty_buffers() in set_page_dirty().
>> 1189 */
>> 1190 return 0;
>> 1191 }
>> 1192 EXPORT_SYMBOL_GPL(noop_set_page_dirty);
>> 1193
>> 1194 void noop_invalidatepage(struct page *page, unsigned int offset,
>> 1195 unsigned int length)
>> 1196 {
>> 1197 /*
>> 1198 * There is no page cache to invalidate in the dax case, however
>> 1199 * we need this callback defined to prevent falling back to
>> 1200 * block_invalidatepage() in do_invalidatepage().
>> 1201 */
>> 1202 }
>> 1203 EXPORT_SYMBOL_GPL(noop_invalidatepage);
>> 1204
1614 ssize_t noop_direct_IO(struct kiocb *iocb, st 1205 ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
1615 { 1206 {
1616 /* 1207 /*
1617 * iomap based filesystems support di 1208 * iomap based filesystems support direct I/O without need for
1618 * this callback. However, it still n 1209 * this callback. However, it still needs to be set in
1619 * inode->a_ops so that open/fcntl kn 1210 * inode->a_ops so that open/fcntl know that direct I/O is
1620 * generally supported. 1211 * generally supported.
1621 */ 1212 */
1622 return -EINVAL; 1213 return -EINVAL;
1623 } 1214 }
1624 EXPORT_SYMBOL_GPL(noop_direct_IO); 1215 EXPORT_SYMBOL_GPL(noop_direct_IO);
1625 1216
1626 /* Because kfree isn't assignment-compatible 1217 /* Because kfree isn't assignment-compatible with void(void*) ;-/ */
1627 void kfree_link(void *p) 1218 void kfree_link(void *p)
1628 { 1219 {
1629 kfree(p); 1220 kfree(p);
1630 } 1221 }
1631 EXPORT_SYMBOL(kfree_link); 1222 EXPORT_SYMBOL(kfree_link);
1632 1223
>> 1224 /*
>> 1225 * nop .set_page_dirty method so that people can use .page_mkwrite on
>> 1226 * anon inodes.
>> 1227 */
>> 1228 static int anon_set_page_dirty(struct page *page)
>> 1229 {
>> 1230 return 0;
>> 1231 };
>> 1232
>> 1233 /*
>> 1234 * A single inode exists for all anon_inode files. Contrary to pipes,
>> 1235 * anon_inode inodes have no associated per-instance data, so we need
>> 1236 * only allocate one of them.
>> 1237 */
1633 struct inode *alloc_anon_inode(struct super_b 1238 struct inode *alloc_anon_inode(struct super_block *s)
1634 { 1239 {
1635 static const struct address_space_ope 1240 static const struct address_space_operations anon_aops = {
1636 .dirty_folio = noop_dirty_ !! 1241 .set_page_dirty = anon_set_page_dirty,
1637 }; 1242 };
1638 struct inode *inode = new_inode_pseud 1243 struct inode *inode = new_inode_pseudo(s);
1639 1244
1640 if (!inode) 1245 if (!inode)
1641 return ERR_PTR(-ENOMEM); 1246 return ERR_PTR(-ENOMEM);
1642 1247
1643 inode->i_ino = get_next_ino(); 1248 inode->i_ino = get_next_ino();
1644 inode->i_mapping->a_ops = &anon_aops; 1249 inode->i_mapping->a_ops = &anon_aops;
1645 1250
1646 /* 1251 /*
1647 * Mark the inode dirty from the very 1252 * Mark the inode dirty from the very beginning,
1648 * that way it will never be moved to 1253 * that way it will never be moved to the dirty
1649 * list because mark_inode_dirty() wi 1254 * list because mark_inode_dirty() will think
1650 * that it already _is_ on the dirty 1255 * that it already _is_ on the dirty list.
1651 */ 1256 */
1652 inode->i_state = I_DIRTY; 1257 inode->i_state = I_DIRTY;
1653 inode->i_mode = S_IRUSR | S_IWUSR; 1258 inode->i_mode = S_IRUSR | S_IWUSR;
1654 inode->i_uid = current_fsuid(); 1259 inode->i_uid = current_fsuid();
1655 inode->i_gid = current_fsgid(); 1260 inode->i_gid = current_fsgid();
1656 inode->i_flags |= S_PRIVATE; 1261 inode->i_flags |= S_PRIVATE;
1657 simple_inode_init_ts(inode); !! 1262 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
1658 return inode; 1263 return inode;
1659 } 1264 }
1660 EXPORT_SYMBOL(alloc_anon_inode); 1265 EXPORT_SYMBOL(alloc_anon_inode);
1661 1266
1662 /** 1267 /**
1663 * simple_nosetlease - generic helper for pro 1268 * simple_nosetlease - generic helper for prohibiting leases
1664 * @filp: file pointer 1269 * @filp: file pointer
1665 * @arg: type of lease to obtain 1270 * @arg: type of lease to obtain
1666 * @flp: new lease supplied for insertion 1271 * @flp: new lease supplied for insertion
1667 * @priv: private data for lm_setup operation 1272 * @priv: private data for lm_setup operation
1668 * 1273 *
1669 * Generic helper for filesystems that do not 1274 * Generic helper for filesystems that do not wish to allow leases to be set.
1670 * All arguments are ignored and it just retu 1275 * All arguments are ignored and it just returns -EINVAL.
1671 */ 1276 */
1672 int 1277 int
1673 simple_nosetlease(struct file *filp, int arg, !! 1278 simple_nosetlease(struct file *filp, long arg, struct file_lock **flp,
1674 void **priv) 1279 void **priv)
1675 { 1280 {
1676 return -EINVAL; 1281 return -EINVAL;
1677 } 1282 }
1678 EXPORT_SYMBOL(simple_nosetlease); 1283 EXPORT_SYMBOL(simple_nosetlease);
1679 1284
1680 /** 1285 /**
1681 * simple_get_link - generic helper to get th 1286 * simple_get_link - generic helper to get the target of "fast" symlinks
1682 * @dentry: not used here 1287 * @dentry: not used here
1683 * @inode: the symlink inode 1288 * @inode: the symlink inode
1684 * @done: not used here 1289 * @done: not used here
1685 * 1290 *
1686 * Generic helper for filesystems to use for 1291 * Generic helper for filesystems to use for symlink inodes where a pointer to
1687 * the symlink target is stored in ->i_link. 1292 * the symlink target is stored in ->i_link. NOTE: this isn't normally called,
1688 * since as an optimization the path lookup c 1293 * since as an optimization the path lookup code uses any non-NULL ->i_link
1689 * directly, without calling ->get_link(). B 1294 * directly, without calling ->get_link(). But ->get_link() still must be set,
1690 * to mark the inode_operations as being for 1295 * to mark the inode_operations as being for a symlink.
1691 * 1296 *
1692 * Return: the symlink target 1297 * Return: the symlink target
1693 */ 1298 */
1694 const char *simple_get_link(struct dentry *de 1299 const char *simple_get_link(struct dentry *dentry, struct inode *inode,
1695 struct delayed_ca 1300 struct delayed_call *done)
1696 { 1301 {
1697 return inode->i_link; 1302 return inode->i_link;
1698 } 1303 }
1699 EXPORT_SYMBOL(simple_get_link); 1304 EXPORT_SYMBOL(simple_get_link);
1700 1305
1701 const struct inode_operations simple_symlink_ 1306 const struct inode_operations simple_symlink_inode_operations = {
1702 .get_link = simple_get_link, 1307 .get_link = simple_get_link,
1703 }; 1308 };
1704 EXPORT_SYMBOL(simple_symlink_inode_operations 1309 EXPORT_SYMBOL(simple_symlink_inode_operations);
1705 1310
1706 /* 1311 /*
1707 * Operations for a permanently empty directo 1312 * Operations for a permanently empty directory.
1708 */ 1313 */
1709 static struct dentry *empty_dir_lookup(struct 1314 static struct dentry *empty_dir_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1710 { 1315 {
1711 return ERR_PTR(-ENOENT); 1316 return ERR_PTR(-ENOENT);
1712 } 1317 }
1713 1318
1714 static int empty_dir_getattr(struct mnt_idmap !! 1319 static int empty_dir_getattr(const struct path *path, struct kstat *stat,
1715 const struct pat <<
1716 u32 request_mask 1320 u32 request_mask, unsigned int query_flags)
1717 { 1321 {
1718 struct inode *inode = d_inode(path->d 1322 struct inode *inode = d_inode(path->dentry);
1719 generic_fillattr(&nop_mnt_idmap, requ !! 1323 generic_fillattr(inode, stat);
1720 return 0; 1324 return 0;
1721 } 1325 }
1722 1326
1723 static int empty_dir_setattr(struct mnt_idmap !! 1327 static int empty_dir_setattr(struct dentry *dentry, struct iattr *attr)
1724 struct dentry *d <<
1725 { 1328 {
1726 return -EPERM; 1329 return -EPERM;
1727 } 1330 }
1728 1331
1729 static ssize_t empty_dir_listxattr(struct den 1332 static ssize_t empty_dir_listxattr(struct dentry *dentry, char *list, size_t size)
1730 { 1333 {
1731 return -EOPNOTSUPP; 1334 return -EOPNOTSUPP;
1732 } 1335 }
1733 1336
1734 static const struct inode_operations empty_di 1337 static const struct inode_operations empty_dir_inode_operations = {
1735 .lookup = empty_dir_lookup, 1338 .lookup = empty_dir_lookup,
1736 .permission = generic_permission, 1339 .permission = generic_permission,
1737 .setattr = empty_dir_setattr, 1340 .setattr = empty_dir_setattr,
1738 .getattr = empty_dir_getattr, 1341 .getattr = empty_dir_getattr,
1739 .listxattr = empty_dir_listxattr 1342 .listxattr = empty_dir_listxattr,
1740 }; 1343 };
1741 1344
1742 static loff_t empty_dir_llseek(struct file *f 1345 static loff_t empty_dir_llseek(struct file *file, loff_t offset, int whence)
1743 { 1346 {
1744 /* An empty directory has two entries 1347 /* An empty directory has two entries . and .. at offsets 0 and 1 */
1745 return generic_file_llseek_size(file, 1348 return generic_file_llseek_size(file, offset, whence, 2, 2);
1746 } 1349 }
1747 1350
1748 static int empty_dir_readdir(struct file *fil 1351 static int empty_dir_readdir(struct file *file, struct dir_context *ctx)
1749 { 1352 {
1750 dir_emit_dots(file, ctx); 1353 dir_emit_dots(file, ctx);
1751 return 0; 1354 return 0;
1752 } 1355 }
1753 1356
1754 static const struct file_operations empty_dir 1357 static const struct file_operations empty_dir_operations = {
1755 .llseek = empty_dir_llseek, 1358 .llseek = empty_dir_llseek,
1756 .read = generic_read_dir, 1359 .read = generic_read_dir,
1757 .iterate_shared = empty_dir_readdir, 1360 .iterate_shared = empty_dir_readdir,
1758 .fsync = noop_fsync, 1361 .fsync = noop_fsync,
1759 }; 1362 };
1760 1363
1761 1364
1762 void make_empty_dir_inode(struct inode *inode 1365 void make_empty_dir_inode(struct inode *inode)
1763 { 1366 {
1764 set_nlink(inode, 2); 1367 set_nlink(inode, 2);
1765 inode->i_mode = S_IFDIR | S_IRUGO | S 1368 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
1766 inode->i_uid = GLOBAL_ROOT_UID; 1369 inode->i_uid = GLOBAL_ROOT_UID;
1767 inode->i_gid = GLOBAL_ROOT_GID; 1370 inode->i_gid = GLOBAL_ROOT_GID;
1768 inode->i_rdev = 0; 1371 inode->i_rdev = 0;
1769 inode->i_size = 0; 1372 inode->i_size = 0;
1770 inode->i_blkbits = PAGE_SHIFT; 1373 inode->i_blkbits = PAGE_SHIFT;
1771 inode->i_blocks = 0; 1374 inode->i_blocks = 0;
1772 1375
1773 inode->i_op = &empty_dir_inode_operat 1376 inode->i_op = &empty_dir_inode_operations;
1774 inode->i_opflags &= ~IOP_XATTR; 1377 inode->i_opflags &= ~IOP_XATTR;
1775 inode->i_fop = &empty_dir_operations; 1378 inode->i_fop = &empty_dir_operations;
1776 } 1379 }
1777 1380
1778 bool is_empty_dir_inode(struct inode *inode) 1381 bool is_empty_dir_inode(struct inode *inode)
1779 { 1382 {
1780 return (inode->i_fop == &empty_dir_op 1383 return (inode->i_fop == &empty_dir_operations) &&
1781 (inode->i_op == &empty_dir_in 1384 (inode->i_op == &empty_dir_inode_operations);
1782 } 1385 }
1783 1386
1784 #if IS_ENABLED(CONFIG_UNICODE) !! 1387 #ifdef CONFIG_UNICODE
>> 1388 /*
>> 1389 * Determine if the name of a dentry should be casefolded.
>> 1390 *
>> 1391 * Return: if names will need casefolding
>> 1392 */
>> 1393 static bool needs_casefold(const struct inode *dir)
>> 1394 {
>> 1395 return IS_CASEFOLDED(dir) && dir->i_sb->s_encoding;
>> 1396 }
>> 1397
1785 /** 1398 /**
1786 * generic_ci_d_compare - generic d_compare i 1399 * generic_ci_d_compare - generic d_compare implementation for casefolding filesystems
1787 * @dentry: dentry whose name we are chec 1400 * @dentry: dentry whose name we are checking against
1788 * @len: len of name of dentry 1401 * @len: len of name of dentry
1789 * @str: str pointer to name of dentry 1402 * @str: str pointer to name of dentry
1790 * @name: Name to compare against 1403 * @name: Name to compare against
1791 * 1404 *
1792 * Return: 0 if names match, 1 if mismatch, o 1405 * Return: 0 if names match, 1 if mismatch, or -ERRNO
1793 */ 1406 */
1794 static int generic_ci_d_compare(const struct !! 1407 int generic_ci_d_compare(const struct dentry *dentry, unsigned int len,
1795 const char *s !! 1408 const char *str, const struct qstr *name)
1796 { 1409 {
1797 const struct dentry *parent; !! 1410 const struct dentry *parent = READ_ONCE(dentry->d_parent);
1798 const struct inode *dir; !! 1411 const struct inode *dir = READ_ONCE(parent->d_inode);
>> 1412 const struct super_block *sb = dentry->d_sb;
>> 1413 const struct unicode_map *um = sb->s_encoding;
>> 1414 struct qstr qstr = QSTR_INIT(str, len);
1799 char strbuf[DNAME_INLINE_LEN]; 1415 char strbuf[DNAME_INLINE_LEN];
1800 struct qstr qstr; !! 1416 int ret;
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 1417
>> 1418 if (!dir || !needs_casefold(dir))
>> 1419 goto fallback;
1819 /* 1420 /*
1820 * If the dentry name is stored in-li 1421 * If the dentry name is stored in-line, then it may be concurrently
1821 * modified by a rename. If this hap 1422 * modified by a rename. If this happens, the VFS will eventually retry
1822 * the lookup, so it doesn't matter w 1423 * the lookup, so it doesn't matter what ->d_compare() returns.
1823 * However, it's unsafe to call utf8_ 1424 * However, it's unsafe to call utf8_strncasecmp() with an unstable
1824 * string. Therefore, we have to cop 1425 * string. Therefore, we have to copy the name into a temporary buffer.
1825 */ 1426 */
1826 if (len <= DNAME_INLINE_LEN - 1) { 1427 if (len <= DNAME_INLINE_LEN - 1) {
1827 memcpy(strbuf, str, len); 1428 memcpy(strbuf, str, len);
1828 strbuf[len] = 0; 1429 strbuf[len] = 0;
1829 str = strbuf; !! 1430 qstr.name = strbuf;
1830 /* prevent compiler from opti 1431 /* prevent compiler from optimizing out the temporary buffer */
1831 barrier(); 1432 barrier();
1832 } 1433 }
1833 qstr.len = len; !! 1434 ret = utf8_strncasecmp(um, name, &qstr);
1834 qstr.name = str; !! 1435 if (ret >= 0)
>> 1436 return ret;
1835 1437
1836 return utf8_strncasecmp(dentry->d_sb- !! 1438 if (sb_has_strict_encoding(sb))
>> 1439 return -EINVAL;
>> 1440 fallback:
>> 1441 if (len != name->len)
>> 1442 return 1;
>> 1443 return !!memcmp(str, name->name, len);
1837 } 1444 }
>> 1445 EXPORT_SYMBOL(generic_ci_d_compare);
1838 1446
1839 /** 1447 /**
1840 * generic_ci_d_hash - generic d_hash impleme 1448 * generic_ci_d_hash - generic d_hash implementation for casefolding filesystems
1841 * @dentry: dentry of the parent director 1449 * @dentry: dentry of the parent directory
1842 * @str: qstr of name whose hash we sh 1450 * @str: qstr of name whose hash we should fill in
1843 * 1451 *
1844 * Return: 0 if hash was successful or unchan 1452 * Return: 0 if hash was successful or unchanged, and -EINVAL on error
1845 */ 1453 */
1846 static int generic_ci_d_hash(const struct den !! 1454 int generic_ci_d_hash(const struct dentry *dentry, struct qstr *str)
1847 { 1455 {
1848 const struct inode *dir = READ_ONCE(d 1456 const struct inode *dir = READ_ONCE(dentry->d_inode);
1849 struct super_block *sb = dentry->d_sb 1457 struct super_block *sb = dentry->d_sb;
1850 const struct unicode_map *um = sb->s_ 1458 const struct unicode_map *um = sb->s_encoding;
1851 int ret; !! 1459 int ret = 0;
1852 1460
1853 if (!dir || !IS_CASEFOLDED(dir)) !! 1461 if (!dir || !needs_casefold(dir))
1854 return 0; 1462 return 0;
1855 1463
1856 ret = utf8_casefold_hash(um, dentry, 1464 ret = utf8_casefold_hash(um, dentry, str);
1857 if (ret < 0 && sb_has_strict_encoding 1465 if (ret < 0 && sb_has_strict_encoding(sb))
1858 return -EINVAL; 1466 return -EINVAL;
1859 return 0; 1467 return 0;
1860 } 1468 }
1861 !! 1469 EXPORT_SYMBOL(generic_ci_d_hash);
1862 static const struct dentry_operations generic <<
1863 .d_hash = generic_ci_d_hash, <<
1864 .d_compare = generic_ci_d_compare, <<
1865 #ifdef CONFIG_FS_ENCRYPTION <<
1866 .d_revalidate = fscrypt_d_revalidate, <<
1867 #endif <<
1868 }; <<
1869 <<
1870 /** <<
1871 * generic_ci_match() - Match a name (case-in <<
1872 * This is a filesystem helper for comparison <<
1873 * generic_ci_d_compare should be used in VFS <<
1874 * <<
1875 * @parent: Inode of the parent of the dirent <<
1876 * @name: name under lookup. <<
1877 * @folded_name: Optional pre-folded name und <<
1878 * @de_name: Dirent name. <<
1879 * @de_name_len: dirent name length. <<
1880 * <<
1881 * Test whether a case-insensitive directory <<
1882 * being searched. If @folded_name is provid <<
1883 * recalculating the casefold of @name. <<
1884 * <<
1885 * Return: > 0 if the directory entry matches <<
1886 * < 0 on error. <<
1887 */ <<
1888 int generic_ci_match(const struct inode *pare <<
1889 const struct qstr *name, <<
1890 const struct qstr *folde <<
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 1470 #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 1471
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