1
2
3
4
5
6#include <linux/errno.h>
7#include <linux/fs.h>
8#include <linux/mount.h>
9#include <linux/dqblk_v2.h>
10#include <linux/kernel.h>
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/quotaops.h>
15
16#include <asm/byteorder.h>
17
18#include "quota_tree.h"
19
20MODULE_AUTHOR("Jan Kara");
21MODULE_DESCRIPTION("Quota trie support");
22MODULE_LICENSE("GPL");
23
24#define __QUOTA_QT_PARANOIA
25
26static int __get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
27{
28 unsigned int epb = info->dqi_usable_bs >> 2;
29
30 depth = info->dqi_qtree_depth - depth - 1;
31 while (depth--)
32 id /= epb;
33 return id % epb;
34}
35
36static int get_index(struct qtree_mem_dqinfo *info, struct kqid qid, int depth)
37{
38 qid_t id = from_kqid(&init_user_ns, qid);
39
40 return __get_index(info, id, depth);
41}
42
43
44static int qtree_dqstr_in_blk(struct qtree_mem_dqinfo *info)
45{
46 return (info->dqi_usable_bs - sizeof(struct qt_disk_dqdbheader))
47 / info->dqi_entry_size;
48}
49
50static char *getdqbuf(size_t size)
51{
52 char *buf = kmalloc(size, GFP_NOFS);
53 if (!buf)
54 printk(KERN_WARNING
55 "VFS: Not enough memory for quota buffers.\n");
56 return buf;
57}
58
59static ssize_t read_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
60{
61 struct super_block *sb = info->dqi_sb;
62
63 memset(buf, 0, info->dqi_usable_bs);
64 return sb->s_op->quota_read(sb, info->dqi_type, buf,
65 info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
66}
67
68static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
69{
70 struct super_block *sb = info->dqi_sb;
71 ssize_t ret;
72
73 ret = sb->s_op->quota_write(sb, info->dqi_type, buf,
74 info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
75 if (ret != info->dqi_usable_bs) {
76 quota_error(sb, "dquota write failed");
77 if (ret >= 0)
78 ret = -EIO;
79 }
80 return ret;
81}
82
83
84static int get_free_dqblk(struct qtree_mem_dqinfo *info)
85{
86 char *buf = getdqbuf(info->dqi_usable_bs);
87 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
88 int ret, blk;
89
90 if (!buf)
91 return -ENOMEM;
92 if (info->dqi_free_blk) {
93 blk = info->dqi_free_blk;
94 ret = read_blk(info, blk, buf);
95 if (ret < 0)
96 goto out_buf;
97 info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free);
98 }
99 else {
100 memset(buf, 0, info->dqi_usable_bs);
101
102 ret = write_blk(info, info->dqi_blocks, buf);
103 if (ret < 0)
104 goto out_buf;
105 blk = info->dqi_blocks++;
106 }
107 mark_info_dirty(info->dqi_sb, info->dqi_type);
108 ret = blk;
109out_buf:
110 kfree(buf);
111 return ret;
112}
113
114
115static int put_free_dqblk(struct qtree_mem_dqinfo *info, char *buf, uint blk)
116{
117 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
118 int err;
119
120 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_blk);
121 dh->dqdh_prev_free = cpu_to_le32(0);
122 dh->dqdh_entries = cpu_to_le16(0);
123 err = write_blk(info, blk, buf);
124 if (err < 0)
125 return err;
126 info->dqi_free_blk = blk;
127 mark_info_dirty(info->dqi_sb, info->dqi_type);
128 return 0;
129}
130
131
132static int remove_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
133 uint blk)
134{
135 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
136 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
137 uint nextblk = le32_to_cpu(dh->dqdh_next_free);
138 uint prevblk = le32_to_cpu(dh->dqdh_prev_free);
139 int err;
140
141 if (!tmpbuf)
142 return -ENOMEM;
143 if (nextblk) {
144 err = read_blk(info, nextblk, tmpbuf);
145 if (err < 0)
146 goto out_buf;
147 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
148 dh->dqdh_prev_free;
149 err = write_blk(info, nextblk, tmpbuf);
150 if (err < 0)
151 goto out_buf;
152 }
153 if (prevblk) {
154 err = read_blk(info, prevblk, tmpbuf);
155 if (err < 0)
156 goto out_buf;
157 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_next_free =
158 dh->dqdh_next_free;
159 err = write_blk(info, prevblk, tmpbuf);
160 if (err < 0)
161 goto out_buf;
162 } else {
163 info->dqi_free_entry = nextblk;
164 mark_info_dirty(info->dqi_sb, info->dqi_type);
165 }
166 kfree(tmpbuf);
167 dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
168
169 if (write_blk(info, blk, buf) < 0)
170 quota_error(info->dqi_sb, "Can't write block (%u) "
171 "with free entries", blk);
172 return 0;
173out_buf:
174 kfree(tmpbuf);
175 return err;
176}
177
178
179static int insert_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
180 uint blk)
181{
182 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
183 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
184 int err;
185
186 if (!tmpbuf)
187 return -ENOMEM;
188 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_entry);
189 dh->dqdh_prev_free = cpu_to_le32(0);
190 err = write_blk(info, blk, buf);
191 if (err < 0)
192 goto out_buf;
193 if (info->dqi_free_entry) {
194 err = read_blk(info, info->dqi_free_entry, tmpbuf);
195 if (err < 0)
196 goto out_buf;
197 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
198 cpu_to_le32(blk);
199 err = write_blk(info, info->dqi_free_entry, tmpbuf);
200 if (err < 0)
201 goto out_buf;
202 }
203 kfree(tmpbuf);
204 info->dqi_free_entry = blk;
205 mark_info_dirty(info->dqi_sb, info->dqi_type);
206 return 0;
207out_buf:
208 kfree(tmpbuf);
209 return err;
210}
211
212
213int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk)
214{
215 int i;
216
217 for (i = 0; i < info->dqi_entry_size; i++)
218 if (disk[i])
219 return 0;
220 return 1;
221}
222EXPORT_SYMBOL(qtree_entry_unused);
223
224
225static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
226 struct dquot *dquot, int *err)
227{
228 uint blk, i;
229 struct qt_disk_dqdbheader *dh;
230 char *buf = getdqbuf(info->dqi_usable_bs);
231 char *ddquot;
232
233 *err = 0;
234 if (!buf) {
235 *err = -ENOMEM;
236 return 0;
237 }
238 dh = (struct qt_disk_dqdbheader *)buf;
239 if (info->dqi_free_entry) {
240 blk = info->dqi_free_entry;
241 *err = read_blk(info, blk, buf);
242 if (*err < 0)
243 goto out_buf;
244 } else {
245 blk = get_free_dqblk(info);
246 if ((int)blk < 0) {
247 *err = blk;
248 kfree(buf);
249 return 0;
250 }
251 memset(buf, 0, info->dqi_usable_bs);
252
253
254 info->dqi_free_entry = blk;
255 mark_info_dirty(dquot->dq_sb, dquot->dq_id.type);
256 }
257
258 if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
259 *err = remove_free_dqentry(info, buf, blk);
260 if (*err < 0) {
261 quota_error(dquot->dq_sb, "Can't remove block (%u) "
262 "from entry free list", blk);
263 goto out_buf;
264 }
265 }
266 le16_add_cpu(&dh->dqdh_entries, 1);
267
268 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
269 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
270 if (qtree_entry_unused(info, ddquot))
271 break;
272 ddquot += info->dqi_entry_size;
273 }
274#ifdef __QUOTA_QT_PARANOIA
275 if (i == qtree_dqstr_in_blk(info)) {
276 quota_error(dquot->dq_sb, "Data block full but it shouldn't");
277 *err = -EIO;
278 goto out_buf;
279 }
280#endif
281 *err = write_blk(info, blk, buf);
282 if (*err < 0) {
283 quota_error(dquot->dq_sb, "Can't write quota data block %u",
284 blk);
285 goto out_buf;
286 }
287 dquot->dq_off = (blk << info->dqi_blocksize_bits) +
288 sizeof(struct qt_disk_dqdbheader) +
289 i * info->dqi_entry_size;
290 kfree(buf);
291 return blk;
292out_buf:
293 kfree(buf);
294 return 0;
295}
296
297
298static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
299 uint *treeblk, int depth)
300{
301 char *buf = getdqbuf(info->dqi_usable_bs);
302 int ret = 0, newson = 0, newact = 0;
303 __le32 *ref;
304 uint newblk;
305
306 if (!buf)
307 return -ENOMEM;
308 if (!*treeblk) {
309 ret = get_free_dqblk(info);
310 if (ret < 0)
311 goto out_buf;
312 *treeblk = ret;
313 memset(buf, 0, info->dqi_usable_bs);
314 newact = 1;
315 } else {
316 ret = read_blk(info, *treeblk, buf);
317 if (ret < 0) {
318 quota_error(dquot->dq_sb, "Can't read tree quota "
319 "block %u", *treeblk);
320 goto out_buf;
321 }
322 }
323 ref = (__le32 *)buf;
324 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
325 if (!newblk)
326 newson = 1;
327 if (depth == info->dqi_qtree_depth - 1) {
328#ifdef __QUOTA_QT_PARANOIA
329 if (newblk) {
330 quota_error(dquot->dq_sb, "Inserting already present "
331 "quota entry (block %u)",
332 le32_to_cpu(ref[get_index(info,
333 dquot->dq_id, depth)]));
334 ret = -EIO;
335 goto out_buf;
336 }
337#endif
338 newblk = find_free_dqentry(info, dquot, &ret);
339 } else {
340 ret = do_insert_tree(info, dquot, &newblk, depth+1);
341 }
342 if (newson && ret >= 0) {
343 ref[get_index(info, dquot->dq_id, depth)] =
344 cpu_to_le32(newblk);
345 ret = write_blk(info, *treeblk, buf);
346 } else if (newact && ret < 0) {
347 put_free_dqblk(info, buf, *treeblk);
348 }
349out_buf:
350 kfree(buf);
351 return ret;
352}
353
354
355static inline int dq_insert_tree(struct qtree_mem_dqinfo *info,
356 struct dquot *dquot)
357{
358 int tmp = QT_TREEOFF;
359
360#ifdef __QUOTA_QT_PARANOIA
361 if (info->dqi_blocks <= QT_TREEOFF) {
362 quota_error(dquot->dq_sb, "Quota tree root isn't allocated!");
363 return -EIO;
364 }
365#endif
366 return do_insert_tree(info, dquot, &tmp, 0);
367}
368
369
370
371
372
373int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
374{
375 int type = dquot->dq_id.type;
376 struct super_block *sb = dquot->dq_sb;
377 ssize_t ret;
378 char *ddquot = getdqbuf(info->dqi_entry_size);
379
380 if (!ddquot)
381 return -ENOMEM;
382
383
384 if (!dquot->dq_off) {
385 ret = dq_insert_tree(info, dquot);
386 if (ret < 0) {
387 quota_error(sb, "Error %zd occurred while creating "
388 "quota", ret);
389 kfree(ddquot);
390 return ret;
391 }
392 }
393 spin_lock(&dquot->dq_dqb_lock);
394 info->dqi_ops->mem2disk_dqblk(ddquot, dquot);
395 spin_unlock(&dquot->dq_dqb_lock);
396 ret = sb->s_op->quota_write(sb, type, ddquot, info->dqi_entry_size,
397 dquot->dq_off);
398 if (ret != info->dqi_entry_size) {
399 quota_error(sb, "dquota write failed");
400 if (ret >= 0)
401 ret = -ENOSPC;
402 } else {
403 ret = 0;
404 }
405 dqstats_inc(DQST_WRITES);
406 kfree(ddquot);
407
408 return ret;
409}
410EXPORT_SYMBOL(qtree_write_dquot);
411
412
413static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
414 uint blk)
415{
416 struct qt_disk_dqdbheader *dh;
417 char *buf = getdqbuf(info->dqi_usable_bs);
418 int ret = 0;
419
420 if (!buf)
421 return -ENOMEM;
422 if (dquot->dq_off >> info->dqi_blocksize_bits != blk) {
423 quota_error(dquot->dq_sb, "Quota structure has offset to "
424 "other block (%u) than it should (%u)", blk,
425 (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
426 goto out_buf;
427 }
428 ret = read_blk(info, blk, buf);
429 if (ret < 0) {
430 quota_error(dquot->dq_sb, "Can't read quota data block %u",
431 blk);
432 goto out_buf;
433 }
434 dh = (struct qt_disk_dqdbheader *)buf;
435 le16_add_cpu(&dh->dqdh_entries, -1);
436 if (!le16_to_cpu(dh->dqdh_entries)) {
437 ret = remove_free_dqentry(info, buf, blk);
438 if (ret >= 0)
439 ret = put_free_dqblk(info, buf, blk);
440 if (ret < 0) {
441 quota_error(dquot->dq_sb, "Can't move quota data block "
442 "(%u) to free list", blk);
443 goto out_buf;
444 }
445 } else {
446 memset(buf +
447 (dquot->dq_off & ((1 << info->dqi_blocksize_bits) - 1)),
448 0, info->dqi_entry_size);
449 if (le16_to_cpu(dh->dqdh_entries) ==
450 qtree_dqstr_in_blk(info) - 1) {
451
452 ret = insert_free_dqentry(info, buf, blk);
453 if (ret < 0) {
454 quota_error(dquot->dq_sb, "Can't insert quota "
455 "data block (%u) to free entry list", blk);
456 goto out_buf;
457 }
458 } else {
459 ret = write_blk(info, blk, buf);
460 if (ret < 0) {
461 quota_error(dquot->dq_sb, "Can't write quota "
462 "data block %u", blk);
463 goto out_buf;
464 }
465 }
466 }
467 dquot->dq_off = 0;
468out_buf:
469 kfree(buf);
470 return ret;
471}
472
473
474static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
475 uint *blk, int depth)
476{
477 char *buf = getdqbuf(info->dqi_usable_bs);
478 int ret = 0;
479 uint newblk;
480 __le32 *ref = (__le32 *)buf;
481
482 if (!buf)
483 return -ENOMEM;
484 ret = read_blk(info, *blk, buf);
485 if (ret < 0) {
486 quota_error(dquot->dq_sb, "Can't read quota data block %u",
487 *blk);
488 goto out_buf;
489 }
490 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
491 if (depth == info->dqi_qtree_depth - 1) {
492 ret = free_dqentry(info, dquot, newblk);
493 newblk = 0;
494 } else {
495 ret = remove_tree(info, dquot, &newblk, depth+1);
496 }
497 if (ret >= 0 && !newblk) {
498 int i;
499 ref[get_index(info, dquot->dq_id, depth)] = cpu_to_le32(0);
500
501 for (i = 0; i < (info->dqi_usable_bs >> 2) && !ref[i]; i++)
502 ;
503
504 if (i == (info->dqi_usable_bs >> 2)
505 && *blk != QT_TREEOFF) {
506 put_free_dqblk(info, buf, *blk);
507 *blk = 0;
508 } else {
509 ret = write_blk(info, *blk, buf);
510 if (ret < 0)
511 quota_error(dquot->dq_sb,
512 "Can't write quota tree block %u",
513 *blk);
514 }
515 }
516out_buf:
517 kfree(buf);
518 return ret;
519}
520
521
522int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
523{
524 uint tmp = QT_TREEOFF;
525
526 if (!dquot->dq_off)
527 return 0;
528 return remove_tree(info, dquot, &tmp, 0);
529}
530EXPORT_SYMBOL(qtree_delete_dquot);
531
532
533static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
534 struct dquot *dquot, uint blk)
535{
536 char *buf = getdqbuf(info->dqi_usable_bs);
537 loff_t ret = 0;
538 int i;
539 char *ddquot;
540
541 if (!buf)
542 return -ENOMEM;
543 ret = read_blk(info, blk, buf);
544 if (ret < 0) {
545 quota_error(dquot->dq_sb, "Can't read quota tree "
546 "block %u", blk);
547 goto out_buf;
548 }
549 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
550 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
551 if (info->dqi_ops->is_id(ddquot, dquot))
552 break;
553 ddquot += info->dqi_entry_size;
554 }
555 if (i == qtree_dqstr_in_blk(info)) {
556 quota_error(dquot->dq_sb,
557 "Quota for id %u referenced but not present",
558 from_kqid(&init_user_ns, dquot->dq_id));
559 ret = -EIO;
560 goto out_buf;
561 } else {
562 ret = (blk << info->dqi_blocksize_bits) + sizeof(struct
563 qt_disk_dqdbheader) + i * info->dqi_entry_size;
564 }
565out_buf:
566 kfree(buf);
567 return ret;
568}
569
570
571static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
572 struct dquot *dquot, uint blk, int depth)
573{
574 char *buf = getdqbuf(info->dqi_usable_bs);
575 loff_t ret = 0;
576 __le32 *ref = (__le32 *)buf;
577
578 if (!buf)
579 return -ENOMEM;
580 ret = read_blk(info, blk, buf);
581 if (ret < 0) {
582 quota_error(dquot->dq_sb, "Can't read quota tree block %u",
583 blk);
584 goto out_buf;
585 }
586 ret = 0;
587 blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
588 if (!blk)
589 goto out_buf;
590 if (depth < info->dqi_qtree_depth - 1)
591 ret = find_tree_dqentry(info, dquot, blk, depth+1);
592 else
593 ret = find_block_dqentry(info, dquot, blk);
594out_buf:
595 kfree(buf);
596 return ret;
597}
598
599
600static inline loff_t find_dqentry(struct qtree_mem_dqinfo *info,
601 struct dquot *dquot)
602{
603 return find_tree_dqentry(info, dquot, QT_TREEOFF, 0);
604}
605
606int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
607{
608 int type = dquot->dq_id.type;
609 struct super_block *sb = dquot->dq_sb;
610 loff_t offset;
611 char *ddquot;
612 int ret = 0;
613
614#ifdef __QUOTA_QT_PARANOIA
615
616 if (!sb_dqopt(dquot->dq_sb)->files[type]) {
617 quota_error(sb, "Quota invalidated while reading!");
618 return -EIO;
619 }
620#endif
621
622 if (!dquot->dq_off) {
623 offset = find_dqentry(info, dquot);
624 if (offset <= 0) {
625 if (offset < 0)
626 quota_error(sb,"Can't read quota structure "
627 "for id %u",
628 from_kqid(&init_user_ns,
629 dquot->dq_id));
630 dquot->dq_off = 0;
631 set_bit(DQ_FAKE_B, &dquot->dq_flags);
632 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
633 ret = offset;
634 goto out;
635 }
636 dquot->dq_off = offset;
637 }
638 ddquot = getdqbuf(info->dqi_entry_size);
639 if (!ddquot)
640 return -ENOMEM;
641 ret = sb->s_op->quota_read(sb, type, ddquot, info->dqi_entry_size,
642 dquot->dq_off);
643 if (ret != info->dqi_entry_size) {
644 if (ret >= 0)
645 ret = -EIO;
646 quota_error(sb, "Error while reading quota structure for id %u",
647 from_kqid(&init_user_ns, dquot->dq_id));
648 set_bit(DQ_FAKE_B, &dquot->dq_flags);
649 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
650 kfree(ddquot);
651 goto out;
652 }
653 spin_lock(&dquot->dq_dqb_lock);
654 info->dqi_ops->disk2mem_dqblk(dquot, ddquot);
655 if (!dquot->dq_dqb.dqb_bhardlimit &&
656 !dquot->dq_dqb.dqb_bsoftlimit &&
657 !dquot->dq_dqb.dqb_ihardlimit &&
658 !dquot->dq_dqb.dqb_isoftlimit)
659 set_bit(DQ_FAKE_B, &dquot->dq_flags);
660 spin_unlock(&dquot->dq_dqb_lock);
661 kfree(ddquot);
662out:
663 dqstats_inc(DQST_READS);
664 return ret;
665}
666EXPORT_SYMBOL(qtree_read_dquot);
667
668
669
670int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
671{
672 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) &&
673 !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
674 return qtree_delete_dquot(info, dquot);
675 return 0;
676}
677EXPORT_SYMBOL(qtree_release_dquot);
678
679static int find_next_id(struct qtree_mem_dqinfo *info, qid_t *id,
680 unsigned int blk, int depth)
681{
682 char *buf = getdqbuf(info->dqi_usable_bs);
683 __le32 *ref = (__le32 *)buf;
684 ssize_t ret;
685 unsigned int epb = info->dqi_usable_bs >> 2;
686 unsigned int level_inc = 1;
687 int i;
688
689 if (!buf)
690 return -ENOMEM;
691
692 for (i = depth; i < info->dqi_qtree_depth - 1; i++)
693 level_inc *= epb;
694
695 ret = read_blk(info, blk, buf);
696 if (ret < 0) {
697 quota_error(info->dqi_sb,
698 "Can't read quota tree block %u", blk);
699 goto out_buf;
700 }
701 for (i = __get_index(info, *id, depth); i < epb; i++) {
702 if (ref[i] == cpu_to_le32(0)) {
703 *id += level_inc;
704 continue;
705 }
706 if (depth == info->dqi_qtree_depth - 1) {
707 ret = 0;
708 goto out_buf;
709 }
710 ret = find_next_id(info, id, le32_to_cpu(ref[i]), depth + 1);
711 if (ret != -ENOENT)
712 break;
713 }
714 if (i == epb) {
715 ret = -ENOENT;
716 goto out_buf;
717 }
718out_buf:
719 kfree(buf);
720 return ret;
721}
722
723int qtree_get_next_id(struct qtree_mem_dqinfo *info, struct kqid *qid)
724{
725 qid_t id = from_kqid(&init_user_ns, *qid);
726 int ret;
727
728 ret = find_next_id(info, &id, QT_TREEOFF, 0);
729 if (ret < 0)
730 return ret;
731 *qid = make_kqid(&init_user_ns, qid->type, id);
732 return 0;
733}
734EXPORT_SYMBOL(qtree_get_next_id);
735
