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1/*
2 * vfsv0 quota IO operations on file
3 */
4
5#include <linux/errno.h>
6#include <linux/fs.h>
7#include <linux/mount.h>
8#include <linux/dqblk_v2.h>
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/quotaops.h>
14
15#include <asm/byteorder.h>
16
17#include "quota_tree.h"
18
19MODULE_AUTHOR("Jan Kara");
20MODULE_DESCRIPTION("Quota trie support");
21MODULE_LICENSE("GPL");
22
23#define __QUOTA_QT_PARANOIA
24
25static int get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
26{
27 unsigned int epb = info->dqi_usable_bs >> 2;
28
29 depth = info->dqi_qtree_depth - depth - 1;
30 while (depth--)
31 id /= epb;
32 return id % epb;
33}
34
35/* Number of entries in one blocks */
36static int qtree_dqstr_in_blk(struct qtree_mem_dqinfo *info)
37{
38 return (info->dqi_usable_bs - sizeof(struct qt_disk_dqdbheader))
39 / info->dqi_entry_size;
40}
41
42static char *getdqbuf(size_t size)
43{
44 char *buf = kmalloc(size, GFP_NOFS);
45 if (!buf)
46 printk(KERN_WARNING
47 "VFS: Not enough memory for quota buffers.\n");
48 return buf;
49}
50
51static ssize_t read_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
52{
53 struct super_block *sb = info->dqi_sb;
54
55 memset(buf, 0, info->dqi_usable_bs);
56 return sb->s_op->quota_read(sb, info->dqi_type, buf,
57 info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
58}
59
60static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
61{
62 struct super_block *sb = info->dqi_sb;
63 ssize_t ret;
64
65 ret = sb->s_op->quota_write(sb, info->dqi_type, buf,
66 info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
67 if (ret != info->dqi_usable_bs) {
68 quota_error(sb, "dquota write failed");
69 if (ret >= 0)
70 ret = -EIO;
71 }
72 return ret;
73}
74
75/* Remove empty block from list and return it */
76static int get_free_dqblk(struct qtree_mem_dqinfo *info)
77{
78 char *buf = getdqbuf(info->dqi_usable_bs);
79 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
80 int ret, blk;
81
82 if (!buf)
83 return -ENOMEM;
84 if (info->dqi_free_blk) {
85 blk = info->dqi_free_blk;
86 ret = read_blk(info, blk, buf);
87 if (ret < 0)
88 goto out_buf;
89 info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free);
90 }
91 else {
92 memset(buf, 0, info->dqi_usable_bs);
93 /* Assure block allocation... */
94 ret = write_blk(info, info->dqi_blocks, buf);
95 if (ret < 0)
96 goto out_buf;
97 blk = info->dqi_blocks++;
98 }
99 mark_info_dirty(info->dqi_sb, info->dqi_type);
100 ret = blk;
101out_buf:
102 kfree(buf);
103 return ret;
104}
105
106/* Insert empty block to the list */
107static int put_free_dqblk(struct qtree_mem_dqinfo *info, char *buf, uint blk)
108{
109 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
110 int err;
111
112 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_blk);
113 dh->dqdh_prev_free = cpu_to_le32(0);
114 dh->dqdh_entries = cpu_to_le16(0);
115 err = write_blk(info, blk, buf);
116 if (err < 0)
117 return err;
118 info->dqi_free_blk = blk;
119 mark_info_dirty(info->dqi_sb, info->dqi_type);
120 return 0;
121}
122
123/* Remove given block from the list of blocks with free entries */
124static int remove_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
125 uint blk)
126{
127 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
128 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
129 uint nextblk = le32_to_cpu(dh->dqdh_next_free);
130 uint prevblk = le32_to_cpu(dh->dqdh_prev_free);
131 int err;
132
133 if (!tmpbuf)
134 return -ENOMEM;
135 if (nextblk) {
136 err = read_blk(info, nextblk, tmpbuf);
137 if (err < 0)
138 goto out_buf;
139 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
140 dh->dqdh_prev_free;
141 err = write_blk(info, nextblk, tmpbuf);
142 if (err < 0)
143 goto out_buf;
144 }
145 if (prevblk) {
146 err = read_blk(info, prevblk, tmpbuf);
147 if (err < 0)
148 goto out_buf;
149 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_next_free =
150 dh->dqdh_next_free;
151 err = write_blk(info, prevblk, tmpbuf);
152 if (err < 0)
153 goto out_buf;
154 } else {
155 info->dqi_free_entry = nextblk;
156 mark_info_dirty(info->dqi_sb, info->dqi_type);
157 }
158 kfree(tmpbuf);
159 dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
160 /* No matter whether write succeeds block is out of list */
161 if (write_blk(info, blk, buf) < 0)
162 quota_error(info->dqi_sb, "Can't write block (%u) "
163 "with free entries", blk);
164 return 0;
165out_buf:
166 kfree(tmpbuf);
167 return err;
168}
169
170/* Insert given block to the beginning of list with free entries */
171static int insert_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
172 uint blk)
173{
174 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
175 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
176 int err;
177
178 if (!tmpbuf)
179 return -ENOMEM;
180 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_entry);
181 dh->dqdh_prev_free = cpu_to_le32(0);
182 err = write_blk(info, blk, buf);
183 if (err < 0)
184 goto out_buf;
185 if (info->dqi_free_entry) {
186 err = read_blk(info, info->dqi_free_entry, tmpbuf);
187 if (err < 0)
188 goto out_buf;
189 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
190 cpu_to_le32(blk);
191 err = write_blk(info, info->dqi_free_entry, tmpbuf);
192 if (err < 0)
193 goto out_buf;
194 }
195 kfree(tmpbuf);
196 info->dqi_free_entry = blk;
197 mark_info_dirty(info->dqi_sb, info->dqi_type);
198 return 0;
199out_buf:
200 kfree(tmpbuf);
201 return err;
202}
203
204/* Is the entry in the block free? */
205int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk)
206{
207 int i;
208
209 for (i = 0; i < info->dqi_entry_size; i++)
210 if (disk[i])
211 return 0;
212 return 1;
213}
214EXPORT_SYMBOL(qtree_entry_unused);
215
216/* Find space for dquot */
217static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
218 struct dquot *dquot, int *err)
219{
220 uint blk, i;
221 struct qt_disk_dqdbheader *dh;
222 char *buf = getdqbuf(info->dqi_usable_bs);
223 char *ddquot;
224
225 *err = 0;
226 if (!buf) {
227 *err = -ENOMEM;
228 return 0;
229 }
230 dh = (struct qt_disk_dqdbheader *)buf;
231 if (info->dqi_free_entry) {
232 blk = info->dqi_free_entry;
233 *err = read_blk(info, blk, buf);
234 if (*err < 0)
235 goto out_buf;
236 } else {
237 blk = get_free_dqblk(info);
238 if ((int)blk < 0) {
239 *err = blk;
240 kfree(buf);
241 return 0;
242 }
243 memset(buf, 0, info->dqi_usable_bs);
244 /* This is enough as the block is already zeroed and the entry
245 * list is empty... */
246 info->dqi_free_entry = blk;
247 mark_info_dirty(dquot->dq_sb, dquot->dq_type);
248 }
249 /* Block will be full? */
250 if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
251 *err = remove_free_dqentry(info, buf, blk);
252 if (*err < 0) {
253 quota_error(dquot->dq_sb, "Can't remove block (%u) "
254 "from entry free list", blk);
255 goto out_buf;
256 }
257 }
258 le16_add_cpu(&dh->dqdh_entries, 1);
259 /* Find free structure in block */
260 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
261 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
262 if (qtree_entry_unused(info, ddquot))
263 break;
264 ddquot += info->dqi_entry_size;
265 }
266#ifdef __QUOTA_QT_PARANOIA
267 if (i == qtree_dqstr_in_blk(info)) {
268 quota_error(dquot->dq_sb, "Data block full but it shouldn't");
269 *err = -EIO;
270 goto out_buf;
271 }
272#endif
273 *err = write_blk(info, blk, buf);
274 if (*err < 0) {
275 quota_error(dquot->dq_sb, "Can't write quota data block %u",
276 blk);
277 goto out_buf;
278 }
279 dquot->dq_off = (blk << info->dqi_blocksize_bits) +
280 sizeof(struct qt_disk_dqdbheader) +
281 i * info->dqi_entry_size;
282 kfree(buf);
283 return blk;
284out_buf:
285 kfree(buf);
286 return 0;
287}
288
289/* Insert reference to structure into the trie */
290static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
291 uint *treeblk, int depth)
292{
293 char *buf = getdqbuf(info->dqi_usable_bs);
294 int ret = 0, newson = 0, newact = 0;
295 __le32 *ref;
296 uint newblk;
297
298 if (!buf)
299 return -ENOMEM;
300 if (!*treeblk) {
301 ret = get_free_dqblk(info);
302 if (ret < 0)
303 goto out_buf;
304 *treeblk = ret;
305 memset(buf, 0, info->dqi_usable_bs);
306 newact = 1;
307 } else {
308 ret = read_blk(info, *treeblk, buf);
309 if (ret < 0) {
310 quota_error(dquot->dq_sb, "Can't read tree quota "
311 "block %u", *treeblk);
312 goto out_buf;
313 }
314 }
315 ref = (__le32 *)buf;
316 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
317 if (!newblk)
318 newson = 1;
319 if (depth == info->dqi_qtree_depth - 1) {
320#ifdef __QUOTA_QT_PARANOIA
321 if (newblk) {
322 quota_error(dquot->dq_sb, "Inserting already present "
323 "quota entry (block %u)",
324 le32_to_cpu(ref[get_index(info,
325 dquot->dq_id, depth)]));
326 ret = -EIO;
327 goto out_buf;
328 }
329#endif
330 newblk = find_free_dqentry(info, dquot, &ret);
331 } else {
332 ret = do_insert_tree(info, dquot, &newblk, depth+1);
333 }
334 if (newson && ret >= 0) {
335 ref[get_index(info, dquot->dq_id, depth)] =
336 cpu_to_le32(newblk);
337 ret = write_blk(info, *treeblk, buf);
338 } else if (newact && ret < 0) {
339 put_free_dqblk(info, buf, *treeblk);
340 }
341out_buf:
342 kfree(buf);
343 return ret;
344}
345
346/* Wrapper for inserting quota structure into tree */
347static inline int dq_insert_tree(struct qtree_mem_dqinfo *info,
348 struct dquot *dquot)
349{
350 int tmp = QT_TREEOFF;
351 return do_insert_tree(info, dquot, &tmp, 0);
352}
353
354/*
355 * We don't have to be afraid of deadlocks as we never have quotas on quota
356 * files...
357 */
358int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
359{
360 int type = dquot->dq_type;
361 struct super_block *sb = dquot->dq_sb;
362 ssize_t ret;
363 char *ddquot = getdqbuf(info->dqi_entry_size);
364
365 if (!ddquot)
366 return -ENOMEM;
367
368 /* dq_off is guarded by dqio_mutex */
369 if (!dquot->dq_off) {
370 ret = dq_insert_tree(info, dquot);
371 if (ret < 0) {
372 quota_error(sb, "Error %zd occurred while creating "
373 "quota", ret);
374 kfree(ddquot);
375 return ret;
376 }
377 }
378 spin_lock(&dq_data_lock);
379 info->dqi_ops->mem2disk_dqblk(ddquot, dquot);
380 spin_unlock(&dq_data_lock);
381 ret = sb->s_op->quota_write(sb, type, ddquot, info->dqi_entry_size,
382 dquot->dq_off);
383 if (ret != info->dqi_entry_size) {
384 quota_error(sb, "dquota write failed");
385 if (ret >= 0)
386 ret = -ENOSPC;
387 } else {
388 ret = 0;
389 }
390 dqstats_inc(DQST_WRITES);
391 kfree(ddquot);
392
393 return ret;
394}
395EXPORT_SYMBOL(qtree_write_dquot);
396
397/* Free dquot entry in data block */
398static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
399 uint blk)
400{
401 struct qt_disk_dqdbheader *dh;
402 char *buf = getdqbuf(info->dqi_usable_bs);
403 int ret = 0;
404
405 if (!buf)
406 return -ENOMEM;
407 if (dquot->dq_off >> info->dqi_blocksize_bits != blk) {
408 quota_error(dquot->dq_sb, "Quota structure has offset to "
409 "other block (%u) than it should (%u)", blk,
410 (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
411 goto out_buf;
412 }
413 ret = read_blk(info, blk, buf);
414 if (ret < 0) {
415 quota_error(dquot->dq_sb, "Can't read quota data block %u",
416 blk);
417 goto out_buf;
418 }
419 dh = (struct qt_disk_dqdbheader *)buf;
420 le16_add_cpu(&dh->dqdh_entries, -1);
421 if (!le16_to_cpu(dh->dqdh_entries)) { /* Block got free? */
422 ret = remove_free_dqentry(info, buf, blk);
423 if (ret >= 0)
424 ret = put_free_dqblk(info, buf, blk);
425 if (ret < 0) {
426 quota_error(dquot->dq_sb, "Can't move quota data block "
427 "(%u) to free list", blk);
428 goto out_buf;
429 }
430 } else {
431 memset(buf +
432 (dquot->dq_off & ((1 << info->dqi_blocksize_bits) - 1)),
433 0, info->dqi_entry_size);
434 if (le16_to_cpu(dh->dqdh_entries) ==
435 qtree_dqstr_in_blk(info) - 1) {
436 /* Insert will write block itself */
437 ret = insert_free_dqentry(info, buf, blk);
438 if (ret < 0) {
439 quota_error(dquot->dq_sb, "Can't insert quota "
440 "data block (%u) to free entry list", blk);
441 goto out_buf;
442 }
443 } else {
444 ret = write_blk(info, blk, buf);
445 if (ret < 0) {
446 quota_error(dquot->dq_sb, "Can't write quota "
447 "data block %u", blk);
448 goto out_buf;
449 }
450 }
451 }
452 dquot->dq_off = 0; /* Quota is now unattached */
453out_buf:
454 kfree(buf);
455 return ret;
456}
457
458/* Remove reference to dquot from tree */
459static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
460 uint *blk, int depth)
461{
462 char *buf = getdqbuf(info->dqi_usable_bs);
463 int ret = 0;
464 uint newblk;
465 __le32 *ref = (__le32 *)buf;
466
467 if (!buf)
468 return -ENOMEM;
469 ret = read_blk(info, *blk, buf);
470 if (ret < 0) {
471 quota_error(dquot->dq_sb, "Can't read quota data block %u",
472 *blk);
473 goto out_buf;
474 }
475 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
476 if (depth == info->dqi_qtree_depth - 1) {
477 ret = free_dqentry(info, dquot, newblk);
478 newblk = 0;
479 } else {
480 ret = remove_tree(info, dquot, &newblk, depth+1);
481 }
482 if (ret >= 0 && !newblk) {
483 int i;
484 ref[get_index(info, dquot->dq_id, depth)] = cpu_to_le32(0);
485 /* Block got empty? */
486 for (i = 0; i < (info->dqi_usable_bs >> 2) && !ref[i]; i++)
487 ;
488 /* Don't put the root block into the free block list */
489 if (i == (info->dqi_usable_bs >> 2)
490 && *blk != QT_TREEOFF) {
491 put_free_dqblk(info, buf, *blk);
492 *blk = 0;
493 } else {
494 ret = write_blk(info, *blk, buf);
495 if (ret < 0)
496 quota_error(dquot->dq_sb,
497 "Can't write quota tree block %u",
498 *blk);
499 }
500 }
501out_buf:
502 kfree(buf);
503 return ret;
504}
505
506/* Delete dquot from tree */
507int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
508{
509 uint tmp = QT_TREEOFF;
510
511 if (!dquot->dq_off) /* Even not allocated? */
512 return 0;
513 return remove_tree(info, dquot, &tmp, 0);
514}
515EXPORT_SYMBOL(qtree_delete_dquot);
516
517/* Find entry in block */
518static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
519 struct dquot *dquot, uint blk)
520{
521 char *buf = getdqbuf(info->dqi_usable_bs);
522 loff_t ret = 0;
523 int i;
524 char *ddquot;
525
526 if (!buf)
527 return -ENOMEM;
528 ret = read_blk(info, blk, buf);
529 if (ret < 0) {
530 quota_error(dquot->dq_sb, "Can't read quota tree "
531 "block %u", blk);
532 goto out_buf;
533 }
534 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
535 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
536 if (info->dqi_ops->is_id(ddquot, dquot))
537 break;
538 ddquot += info->dqi_entry_size;
539 }
540 if (i == qtree_dqstr_in_blk(info)) {
541 quota_error(dquot->dq_sb, "Quota for id %u referenced "
542 "but not present", dquot->dq_id);
543 ret = -EIO;
544 goto out_buf;
545 } else {
546 ret = (blk << info->dqi_blocksize_bits) + sizeof(struct
547 qt_disk_dqdbheader) + i * info->dqi_entry_size;
548 }
549out_buf:
550 kfree(buf);
551 return ret;
552}
553
554/* Find entry for given id in the tree */
555static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
556 struct dquot *dquot, uint blk, int depth)
557{
558 char *buf = getdqbuf(info->dqi_usable_bs);
559 loff_t ret = 0;
560 __le32 *ref = (__le32 *)buf;
561
562 if (!buf)
563 return -ENOMEM;
564 ret = read_blk(info, blk, buf);
565 if (ret < 0) {
566 quota_error(dquot->dq_sb, "Can't read quota tree block %u",
567 blk);
568 goto out_buf;
569 }
570 ret = 0;
571 blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
572 if (!blk) /* No reference? */
573 goto out_buf;
574 if (depth < info->dqi_qtree_depth - 1)
575 ret = find_tree_dqentry(info, dquot, blk, depth+1);
576 else
577 ret = find_block_dqentry(info, dquot, blk);
578out_buf:
579 kfree(buf);
580 return ret;
581}
582
583/* Find entry for given id in the tree - wrapper function */
584static inline loff_t find_dqentry(struct qtree_mem_dqinfo *info,
585 struct dquot *dquot)
586{
587 return find_tree_dqentry(info, dquot, QT_TREEOFF, 0);
588}
589
590int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
591{
592 int type = dquot->dq_type;
593 struct super_block *sb = dquot->dq_sb;
594 loff_t offset;
595 char *ddquot;
596 int ret = 0;
597
598#ifdef __QUOTA_QT_PARANOIA
599 /* Invalidated quota? */
600 if (!sb_dqopt(dquot->dq_sb)->files[type]) {
601 quota_error(sb, "Quota invalidated while reading!");
602 return -EIO;
603 }
604#endif
605 /* Do we know offset of the dquot entry in the quota file? */
606 if (!dquot->dq_off) {
607 offset = find_dqentry(info, dquot);
608 if (offset <= 0) { /* Entry not present? */
609 if (offset < 0)
610 quota_error(sb, "Can't read quota structure "
611 "for id %u", dquot->dq_id);
612 dquot->dq_off = 0;
613 set_bit(DQ_FAKE_B, &dquot->dq_flags);
614 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
615 ret = offset;
616 goto out;
617 }
618 dquot->dq_off = offset;
619 }
620 ddquot = getdqbuf(info->dqi_entry_size);
621 if (!ddquot)
622 return -ENOMEM;
623 ret = sb->s_op->quota_read(sb, type, ddquot, info->dqi_entry_size,
624 dquot->dq_off);
625 if (ret != info->dqi_entry_size) {
626 if (ret >= 0)
627 ret = -EIO;
628 quota_error(sb, "Error while reading quota structure for id %u",
629 dquot->dq_id);
630 set_bit(DQ_FAKE_B, &dquot->dq_flags);
631 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
632 kfree(ddquot);
633 goto out;
634 }
635 spin_lock(&dq_data_lock);
636 info->dqi_ops->disk2mem_dqblk(dquot, ddquot);
637 if (!dquot->dq_dqb.dqb_bhardlimit &&
638 !dquot->dq_dqb.dqb_bsoftlimit &&
639 !dquot->dq_dqb.dqb_ihardlimit &&
640 !dquot->dq_dqb.dqb_isoftlimit)
641 set_bit(DQ_FAKE_B, &dquot->dq_flags);
642 spin_unlock(&dq_data_lock);
643 kfree(ddquot);
644out:
645 dqstats_inc(DQST_READS);
646 return ret;
647}
648EXPORT_SYMBOL(qtree_read_dquot);
649
650/* Check whether dquot should not be deleted. We know we are
651 * the only one operating on dquot (thanks to dq_lock) */
652int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
653{
654 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) &&
655 !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
656 return qtree_delete_dquot(info, dquot);
657 return 0;
658}
659EXPORT_SYMBOL(qtree_release_dquot);
1/*
2 * vfsv0 quota IO operations on file
3 */
4
5#include <linux/errno.h>
6#include <linux/fs.h>
7#include <linux/mount.h>
8#include <linux/dqblk_v2.h>
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/quotaops.h>
14
15#include <asm/byteorder.h>
16
17#include "quota_tree.h"
18
19MODULE_AUTHOR("Jan Kara");
20MODULE_DESCRIPTION("Quota trie support");
21MODULE_LICENSE("GPL");
22
23#define __QUOTA_QT_PARANOIA
24
25static int __get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
26{
27 unsigned int epb = info->dqi_usable_bs >> 2;
28
29 depth = info->dqi_qtree_depth - depth - 1;
30 while (depth--)
31 id /= epb;
32 return id % epb;
33}
34
35static int get_index(struct qtree_mem_dqinfo *info, struct kqid qid, int depth)
36{
37 qid_t id = from_kqid(&init_user_ns, qid);
38
39 return __get_index(info, id, depth);
40}
41
42/* Number of entries in one blocks */
43static int qtree_dqstr_in_blk(struct qtree_mem_dqinfo *info)
44{
45 return (info->dqi_usable_bs - sizeof(struct qt_disk_dqdbheader))
46 / info->dqi_entry_size;
47}
48
49static char *getdqbuf(size_t size)
50{
51 char *buf = kmalloc(size, GFP_NOFS);
52 if (!buf)
53 printk(KERN_WARNING
54 "VFS: Not enough memory for quota buffers.\n");
55 return buf;
56}
57
58static ssize_t read_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
59{
60 struct super_block *sb = info->dqi_sb;
61
62 memset(buf, 0, info->dqi_usable_bs);
63 return sb->s_op->quota_read(sb, info->dqi_type, buf,
64 info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
65}
66
67static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
68{
69 struct super_block *sb = info->dqi_sb;
70 ssize_t ret;
71
72 ret = sb->s_op->quota_write(sb, info->dqi_type, buf,
73 info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
74 if (ret != info->dqi_usable_bs) {
75 quota_error(sb, "dquota write failed");
76 if (ret >= 0)
77 ret = -EIO;
78 }
79 return ret;
80}
81
82/* Remove empty block from list and return it */
83static int get_free_dqblk(struct qtree_mem_dqinfo *info)
84{
85 char *buf = getdqbuf(info->dqi_usable_bs);
86 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
87 int ret, blk;
88
89 if (!buf)
90 return -ENOMEM;
91 if (info->dqi_free_blk) {
92 blk = info->dqi_free_blk;
93 ret = read_blk(info, blk, buf);
94 if (ret < 0)
95 goto out_buf;
96 info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free);
97 }
98 else {
99 memset(buf, 0, info->dqi_usable_bs);
100 /* Assure block allocation... */
101 ret = write_blk(info, info->dqi_blocks, buf);
102 if (ret < 0)
103 goto out_buf;
104 blk = info->dqi_blocks++;
105 }
106 mark_info_dirty(info->dqi_sb, info->dqi_type);
107 ret = blk;
108out_buf:
109 kfree(buf);
110 return ret;
111}
112
113/* Insert empty block to the list */
114static int put_free_dqblk(struct qtree_mem_dqinfo *info, char *buf, uint blk)
115{
116 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
117 int err;
118
119 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_blk);
120 dh->dqdh_prev_free = cpu_to_le32(0);
121 dh->dqdh_entries = cpu_to_le16(0);
122 err = write_blk(info, blk, buf);
123 if (err < 0)
124 return err;
125 info->dqi_free_blk = blk;
126 mark_info_dirty(info->dqi_sb, info->dqi_type);
127 return 0;
128}
129
130/* Remove given block from the list of blocks with free entries */
131static int remove_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
132 uint blk)
133{
134 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
135 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
136 uint nextblk = le32_to_cpu(dh->dqdh_next_free);
137 uint prevblk = le32_to_cpu(dh->dqdh_prev_free);
138 int err;
139
140 if (!tmpbuf)
141 return -ENOMEM;
142 if (nextblk) {
143 err = read_blk(info, nextblk, tmpbuf);
144 if (err < 0)
145 goto out_buf;
146 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
147 dh->dqdh_prev_free;
148 err = write_blk(info, nextblk, tmpbuf);
149 if (err < 0)
150 goto out_buf;
151 }
152 if (prevblk) {
153 err = read_blk(info, prevblk, tmpbuf);
154 if (err < 0)
155 goto out_buf;
156 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_next_free =
157 dh->dqdh_next_free;
158 err = write_blk(info, prevblk, tmpbuf);
159 if (err < 0)
160 goto out_buf;
161 } else {
162 info->dqi_free_entry = nextblk;
163 mark_info_dirty(info->dqi_sb, info->dqi_type);
164 }
165 kfree(tmpbuf);
166 dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
167 /* No matter whether write succeeds block is out of list */
168 if (write_blk(info, blk, buf) < 0)
169 quota_error(info->dqi_sb, "Can't write block (%u) "
170 "with free entries", blk);
171 return 0;
172out_buf:
173 kfree(tmpbuf);
174 return err;
175}
176
177/* Insert given block to the beginning of list with free entries */
178static int insert_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
179 uint blk)
180{
181 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
182 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
183 int err;
184
185 if (!tmpbuf)
186 return -ENOMEM;
187 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_entry);
188 dh->dqdh_prev_free = cpu_to_le32(0);
189 err = write_blk(info, blk, buf);
190 if (err < 0)
191 goto out_buf;
192 if (info->dqi_free_entry) {
193 err = read_blk(info, info->dqi_free_entry, tmpbuf);
194 if (err < 0)
195 goto out_buf;
196 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
197 cpu_to_le32(blk);
198 err = write_blk(info, info->dqi_free_entry, tmpbuf);
199 if (err < 0)
200 goto out_buf;
201 }
202 kfree(tmpbuf);
203 info->dqi_free_entry = blk;
204 mark_info_dirty(info->dqi_sb, info->dqi_type);
205 return 0;
206out_buf:
207 kfree(tmpbuf);
208 return err;
209}
210
211/* Is the entry in the block free? */
212int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk)
213{
214 int i;
215
216 for (i = 0; i < info->dqi_entry_size; i++)
217 if (disk[i])
218 return 0;
219 return 1;
220}
221EXPORT_SYMBOL(qtree_entry_unused);
222
223/* Find space for dquot */
224static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
225 struct dquot *dquot, int *err)
226{
227 uint blk, i;
228 struct qt_disk_dqdbheader *dh;
229 char *buf = getdqbuf(info->dqi_usable_bs);
230 char *ddquot;
231
232 *err = 0;
233 if (!buf) {
234 *err = -ENOMEM;
235 return 0;
236 }
237 dh = (struct qt_disk_dqdbheader *)buf;
238 if (info->dqi_free_entry) {
239 blk = info->dqi_free_entry;
240 *err = read_blk(info, blk, buf);
241 if (*err < 0)
242 goto out_buf;
243 } else {
244 blk = get_free_dqblk(info);
245 if ((int)blk < 0) {
246 *err = blk;
247 kfree(buf);
248 return 0;
249 }
250 memset(buf, 0, info->dqi_usable_bs);
251 /* This is enough as the block is already zeroed and the entry
252 * list is empty... */
253 info->dqi_free_entry = blk;
254 mark_info_dirty(dquot->dq_sb, dquot->dq_id.type);
255 }
256 /* Block will be full? */
257 if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
258 *err = remove_free_dqentry(info, buf, blk);
259 if (*err < 0) {
260 quota_error(dquot->dq_sb, "Can't remove block (%u) "
261 "from entry free list", blk);
262 goto out_buf;
263 }
264 }
265 le16_add_cpu(&dh->dqdh_entries, 1);
266 /* Find free structure in block */
267 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
268 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
269 if (qtree_entry_unused(info, ddquot))
270 break;
271 ddquot += info->dqi_entry_size;
272 }
273#ifdef __QUOTA_QT_PARANOIA
274 if (i == qtree_dqstr_in_blk(info)) {
275 quota_error(dquot->dq_sb, "Data block full but it shouldn't");
276 *err = -EIO;
277 goto out_buf;
278 }
279#endif
280 *err = write_blk(info, blk, buf);
281 if (*err < 0) {
282 quota_error(dquot->dq_sb, "Can't write quota data block %u",
283 blk);
284 goto out_buf;
285 }
286 dquot->dq_off = (blk << info->dqi_blocksize_bits) +
287 sizeof(struct qt_disk_dqdbheader) +
288 i * info->dqi_entry_size;
289 kfree(buf);
290 return blk;
291out_buf:
292 kfree(buf);
293 return 0;
294}
295
296/* Insert reference to structure into the trie */
297static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
298 uint *treeblk, int depth)
299{
300 char *buf = getdqbuf(info->dqi_usable_bs);
301 int ret = 0, newson = 0, newact = 0;
302 __le32 *ref;
303 uint newblk;
304
305 if (!buf)
306 return -ENOMEM;
307 if (!*treeblk) {
308 ret = get_free_dqblk(info);
309 if (ret < 0)
310 goto out_buf;
311 *treeblk = ret;
312 memset(buf, 0, info->dqi_usable_bs);
313 newact = 1;
314 } else {
315 ret = read_blk(info, *treeblk, buf);
316 if (ret < 0) {
317 quota_error(dquot->dq_sb, "Can't read tree quota "
318 "block %u", *treeblk);
319 goto out_buf;
320 }
321 }
322 ref = (__le32 *)buf;
323 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
324 if (!newblk)
325 newson = 1;
326 if (depth == info->dqi_qtree_depth - 1) {
327#ifdef __QUOTA_QT_PARANOIA
328 if (newblk) {
329 quota_error(dquot->dq_sb, "Inserting already present "
330 "quota entry (block %u)",
331 le32_to_cpu(ref[get_index(info,
332 dquot->dq_id, depth)]));
333 ret = -EIO;
334 goto out_buf;
335 }
336#endif
337 newblk = find_free_dqentry(info, dquot, &ret);
338 } else {
339 ret = do_insert_tree(info, dquot, &newblk, depth+1);
340 }
341 if (newson && ret >= 0) {
342 ref[get_index(info, dquot->dq_id, depth)] =
343 cpu_to_le32(newblk);
344 ret = write_blk(info, *treeblk, buf);
345 } else if (newact && ret < 0) {
346 put_free_dqblk(info, buf, *treeblk);
347 }
348out_buf:
349 kfree(buf);
350 return ret;
351}
352
353/* Wrapper for inserting quota structure into tree */
354static inline int dq_insert_tree(struct qtree_mem_dqinfo *info,
355 struct dquot *dquot)
356{
357 int tmp = QT_TREEOFF;
358
359#ifdef __QUOTA_QT_PARANOIA
360 if (info->dqi_blocks <= QT_TREEOFF) {
361 quota_error(dquot->dq_sb, "Quota tree root isn't allocated!");
362 return -EIO;
363 }
364#endif
365 return do_insert_tree(info, dquot, &tmp, 0);
366}
367
368/*
369 * We don't have to be afraid of deadlocks as we never have quotas on quota
370 * files...
371 */
372int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
373{
374 int type = dquot->dq_id.type;
375 struct super_block *sb = dquot->dq_sb;
376 ssize_t ret;
377 char *ddquot = getdqbuf(info->dqi_entry_size);
378
379 if (!ddquot)
380 return -ENOMEM;
381
382 /* dq_off is guarded by dqio_mutex */
383 if (!dquot->dq_off) {
384 ret = dq_insert_tree(info, dquot);
385 if (ret < 0) {
386 quota_error(sb, "Error %zd occurred while creating "
387 "quota", ret);
388 kfree(ddquot);
389 return ret;
390 }
391 }
392 spin_lock(&dq_data_lock);
393 info->dqi_ops->mem2disk_dqblk(ddquot, dquot);
394 spin_unlock(&dq_data_lock);
395 ret = sb->s_op->quota_write(sb, type, ddquot, info->dqi_entry_size,
396 dquot->dq_off);
397 if (ret != info->dqi_entry_size) {
398 quota_error(sb, "dquota write failed");
399 if (ret >= 0)
400 ret = -ENOSPC;
401 } else {
402 ret = 0;
403 }
404 dqstats_inc(DQST_WRITES);
405 kfree(ddquot);
406
407 return ret;
408}
409EXPORT_SYMBOL(qtree_write_dquot);
410
411/* Free dquot entry in data block */
412static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
413 uint blk)
414{
415 struct qt_disk_dqdbheader *dh;
416 char *buf = getdqbuf(info->dqi_usable_bs);
417 int ret = 0;
418
419 if (!buf)
420 return -ENOMEM;
421 if (dquot->dq_off >> info->dqi_blocksize_bits != blk) {
422 quota_error(dquot->dq_sb, "Quota structure has offset to "
423 "other block (%u) than it should (%u)", blk,
424 (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
425 goto out_buf;
426 }
427 ret = read_blk(info, blk, buf);
428 if (ret < 0) {
429 quota_error(dquot->dq_sb, "Can't read quota data block %u",
430 blk);
431 goto out_buf;
432 }
433 dh = (struct qt_disk_dqdbheader *)buf;
434 le16_add_cpu(&dh->dqdh_entries, -1);
435 if (!le16_to_cpu(dh->dqdh_entries)) { /* Block got free? */
436 ret = remove_free_dqentry(info, buf, blk);
437 if (ret >= 0)
438 ret = put_free_dqblk(info, buf, blk);
439 if (ret < 0) {
440 quota_error(dquot->dq_sb, "Can't move quota data block "
441 "(%u) to free list", blk);
442 goto out_buf;
443 }
444 } else {
445 memset(buf +
446 (dquot->dq_off & ((1 << info->dqi_blocksize_bits) - 1)),
447 0, info->dqi_entry_size);
448 if (le16_to_cpu(dh->dqdh_entries) ==
449 qtree_dqstr_in_blk(info) - 1) {
450 /* Insert will write block itself */
451 ret = insert_free_dqentry(info, buf, blk);
452 if (ret < 0) {
453 quota_error(dquot->dq_sb, "Can't insert quota "
454 "data block (%u) to free entry list", blk);
455 goto out_buf;
456 }
457 } else {
458 ret = write_blk(info, blk, buf);
459 if (ret < 0) {
460 quota_error(dquot->dq_sb, "Can't write quota "
461 "data block %u", blk);
462 goto out_buf;
463 }
464 }
465 }
466 dquot->dq_off = 0; /* Quota is now unattached */
467out_buf:
468 kfree(buf);
469 return ret;
470}
471
472/* Remove reference to dquot from tree */
473static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
474 uint *blk, int depth)
475{
476 char *buf = getdqbuf(info->dqi_usable_bs);
477 int ret = 0;
478 uint newblk;
479 __le32 *ref = (__le32 *)buf;
480
481 if (!buf)
482 return -ENOMEM;
483 ret = read_blk(info, *blk, buf);
484 if (ret < 0) {
485 quota_error(dquot->dq_sb, "Can't read quota data block %u",
486 *blk);
487 goto out_buf;
488 }
489 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
490 if (depth == info->dqi_qtree_depth - 1) {
491 ret = free_dqentry(info, dquot, newblk);
492 newblk = 0;
493 } else {
494 ret = remove_tree(info, dquot, &newblk, depth+1);
495 }
496 if (ret >= 0 && !newblk) {
497 int i;
498 ref[get_index(info, dquot->dq_id, depth)] = cpu_to_le32(0);
499 /* Block got empty? */
500 for (i = 0; i < (info->dqi_usable_bs >> 2) && !ref[i]; i++)
501 ;
502 /* Don't put the root block into the free block list */
503 if (i == (info->dqi_usable_bs >> 2)
504 && *blk != QT_TREEOFF) {
505 put_free_dqblk(info, buf, *blk);
506 *blk = 0;
507 } else {
508 ret = write_blk(info, *blk, buf);
509 if (ret < 0)
510 quota_error(dquot->dq_sb,
511 "Can't write quota tree block %u",
512 *blk);
513 }
514 }
515out_buf:
516 kfree(buf);
517 return ret;
518}
519
520/* Delete dquot from tree */
521int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
522{
523 uint tmp = QT_TREEOFF;
524
525 if (!dquot->dq_off) /* Even not allocated? */
526 return 0;
527 return remove_tree(info, dquot, &tmp, 0);
528}
529EXPORT_SYMBOL(qtree_delete_dquot);
530
531/* Find entry in block */
532static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
533 struct dquot *dquot, uint blk)
534{
535 char *buf = getdqbuf(info->dqi_usable_bs);
536 loff_t ret = 0;
537 int i;
538 char *ddquot;
539
540 if (!buf)
541 return -ENOMEM;
542 ret = read_blk(info, blk, buf);
543 if (ret < 0) {
544 quota_error(dquot->dq_sb, "Can't read quota tree "
545 "block %u", blk);
546 goto out_buf;
547 }
548 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
549 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
550 if (info->dqi_ops->is_id(ddquot, dquot))
551 break;
552 ddquot += info->dqi_entry_size;
553 }
554 if (i == qtree_dqstr_in_blk(info)) {
555 quota_error(dquot->dq_sb,
556 "Quota for id %u referenced but not present",
557 from_kqid(&init_user_ns, dquot->dq_id));
558 ret = -EIO;
559 goto out_buf;
560 } else {
561 ret = (blk << info->dqi_blocksize_bits) + sizeof(struct
562 qt_disk_dqdbheader) + i * info->dqi_entry_size;
563 }
564out_buf:
565 kfree(buf);
566 return ret;
567}
568
569/* Find entry for given id in the tree */
570static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
571 struct dquot *dquot, uint blk, int depth)
572{
573 char *buf = getdqbuf(info->dqi_usable_bs);
574 loff_t ret = 0;
575 __le32 *ref = (__le32 *)buf;
576
577 if (!buf)
578 return -ENOMEM;
579 ret = read_blk(info, blk, buf);
580 if (ret < 0) {
581 quota_error(dquot->dq_sb, "Can't read quota tree block %u",
582 blk);
583 goto out_buf;
584 }
585 ret = 0;
586 blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
587 if (!blk) /* No reference? */
588 goto out_buf;
589 if (depth < info->dqi_qtree_depth - 1)
590 ret = find_tree_dqentry(info, dquot, blk, depth+1);
591 else
592 ret = find_block_dqentry(info, dquot, blk);
593out_buf:
594 kfree(buf);
595 return ret;
596}
597
598/* Find entry for given id in the tree - wrapper function */
599static inline loff_t find_dqentry(struct qtree_mem_dqinfo *info,
600 struct dquot *dquot)
601{
602 return find_tree_dqentry(info, dquot, QT_TREEOFF, 0);
603}
604
605int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
606{
607 int type = dquot->dq_id.type;
608 struct super_block *sb = dquot->dq_sb;
609 loff_t offset;
610 char *ddquot;
611 int ret = 0;
612
613#ifdef __QUOTA_QT_PARANOIA
614 /* Invalidated quota? */
615 if (!sb_dqopt(dquot->dq_sb)->files[type]) {
616 quota_error(sb, "Quota invalidated while reading!");
617 return -EIO;
618 }
619#endif
620 /* Do we know offset of the dquot entry in the quota file? */
621 if (!dquot->dq_off) {
622 offset = find_dqentry(info, dquot);
623 if (offset <= 0) { /* Entry not present? */
624 if (offset < 0)
625 quota_error(sb,"Can't read quota structure "
626 "for id %u",
627 from_kqid(&init_user_ns,
628 dquot->dq_id));
629 dquot->dq_off = 0;
630 set_bit(DQ_FAKE_B, &dquot->dq_flags);
631 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
632 ret = offset;
633 goto out;
634 }
635 dquot->dq_off = offset;
636 }
637 ddquot = getdqbuf(info->dqi_entry_size);
638 if (!ddquot)
639 return -ENOMEM;
640 ret = sb->s_op->quota_read(sb, type, ddquot, info->dqi_entry_size,
641 dquot->dq_off);
642 if (ret != info->dqi_entry_size) {
643 if (ret >= 0)
644 ret = -EIO;
645 quota_error(sb, "Error while reading quota structure for id %u",
646 from_kqid(&init_user_ns, dquot->dq_id));
647 set_bit(DQ_FAKE_B, &dquot->dq_flags);
648 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
649 kfree(ddquot);
650 goto out;
651 }
652 spin_lock(&dq_data_lock);
653 info->dqi_ops->disk2mem_dqblk(dquot, ddquot);
654 if (!dquot->dq_dqb.dqb_bhardlimit &&
655 !dquot->dq_dqb.dqb_bsoftlimit &&
656 !dquot->dq_dqb.dqb_ihardlimit &&
657 !dquot->dq_dqb.dqb_isoftlimit)
658 set_bit(DQ_FAKE_B, &dquot->dq_flags);
659 spin_unlock(&dq_data_lock);
660 kfree(ddquot);
661out:
662 dqstats_inc(DQST_READS);
663 return ret;
664}
665EXPORT_SYMBOL(qtree_read_dquot);
666
667/* Check whether dquot should not be deleted. We know we are
668 * the only one operating on dquot (thanks to dq_lock) */
669int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
670{
671 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) &&
672 !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
673 return qtree_delete_dquot(info, dquot);
674 return 0;
675}
676EXPORT_SYMBOL(qtree_release_dquot);
677
678static int find_next_id(struct qtree_mem_dqinfo *info, qid_t *id,
679 unsigned int blk, int depth)
680{
681 char *buf = getdqbuf(info->dqi_usable_bs);
682 __le32 *ref = (__le32 *)buf;
683 ssize_t ret;
684 unsigned int epb = info->dqi_usable_bs >> 2;
685 unsigned int level_inc = 1;
686 int i;
687
688 if (!buf)
689 return -ENOMEM;
690
691 for (i = depth; i < info->dqi_qtree_depth - 1; i++)
692 level_inc *= epb;
693
694 ret = read_blk(info, blk, buf);
695 if (ret < 0) {
696 quota_error(info->dqi_sb,
697 "Can't read quota tree block %u", blk);
698 goto out_buf;
699 }
700 for (i = __get_index(info, *id, depth); i < epb; i++) {
701 if (ref[i] == cpu_to_le32(0)) {
702 *id += level_inc;
703 continue;
704 }
705 if (depth == info->dqi_qtree_depth - 1) {
706 ret = 0;
707 goto out_buf;
708 }
709 ret = find_next_id(info, id, le32_to_cpu(ref[i]), depth + 1);
710 if (ret != -ENOENT)
711 break;
712 }
713 if (i == epb) {
714 ret = -ENOENT;
715 goto out_buf;
716 }
717out_buf:
718 kfree(buf);
719 return ret;
720}
721
722int qtree_get_next_id(struct qtree_mem_dqinfo *info, struct kqid *qid)
723{
724 qid_t id = from_kqid(&init_user_ns, *qid);
725 int ret;
726
727 ret = find_next_id(info, &id, QT_TREEOFF, 0);
728 if (ret < 0)
729 return ret;
730 *qid = make_kqid(&init_user_ns, qid->type, id);
731 return 0;
732}
733EXPORT_SYMBOL(qtree_get_next_id);