1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2010, 2023 Red Hat, Inc.
4 * All Rights Reserved.
5 */
6 #include "xfs.h"
7 #include "xfs_shared.h"
8 #include "xfs_format.h"
9 #include "xfs_log_format.h"
10 #include "xfs_trans_resv.h"
11 #include "xfs_trans.h"
12 #include "xfs_mount.h"
13 #include "xfs_btree.h"
14 #include "xfs_alloc_btree.h"
15 #include "xfs_alloc.h"
16 #include "xfs_discard.h"
17 #include "xfs_error.h"
18 #include "xfs_extent_busy.h"
19 #include "xfs_trace.h"
20 #include "xfs_log.h"
21 #include "xfs_ag.h"
22 #include "xfs_health.h"
23 #include "xfs_rtbitmap.h"
24
25 /*
26 * Notes on an efficient, low latency fstrim algorithm
27 *
28 * We need to walk the filesystem free space and issue discards on the free
29 * space that meet the search criteria (size and location). We cannot issue
30 * discards on extents that might be in use, or are so recently in use they are
31 * still marked as busy. To serialise against extent state changes whilst we are
32 * gathering extents to trim, we must hold the AGF lock to lock out other
33 * allocations and extent free operations that might change extent state.
34 *
35 * However, we cannot just hold the AGF for the entire AG free space walk whilst
36 * we issue discards on each free space that is found. Storage devices can have
37 * extremely slow discard implementations (e.g. ceph RBD) and so walking a
38 * couple of million free extents and issuing synchronous discards on each
39 * extent can take a *long* time. Whilst we are doing this walk, nothing else
40 * can access the AGF, and we can stall transactions and hence the log whilst
41 * modifications wait for the AGF lock to be released. This can lead hung tasks
42 * kicking the hung task timer and rebooting the system. This is bad.
43 *
44 * Hence we need to take a leaf from the bulkstat playbook. It takes the AGI
45 * lock, gathers a range of inode cluster buffers that are allocated, drops the
46 * AGI lock and then reads all the inode cluster buffers and processes them. It
47 * loops doing this, using a cursor to keep track of where it is up to in the AG
48 * for each iteration to restart the INOBT lookup from.
49 *
50 * We can't do this exactly with free space - once we drop the AGF lock, the
51 * state of the free extent is out of our control and we cannot run a discard
52 * safely on it in this situation. Unless, of course, we've marked the free
53 * extent as busy and undergoing a discard operation whilst we held the AGF
54 * locked.
55 *
56 * This is exactly how online discard works - free extents are marked busy when
57 * they are freed, and once the extent free has been committed to the journal,
58 * the busy extent record is marked as "undergoing discard" and the discard is
59 * then issued on the free extent. Once the discard completes, the busy extent
60 * record is removed and the extent is able to be allocated again.
61 *
62 * In the context of fstrim, if we find a free extent we need to discard, we
63 * don't have to discard it immediately. All we need to do it record that free
64 * extent as being busy and under discard, and all the allocation routines will
65 * now avoid trying to allocate it. Hence if we mark the extent as busy under
66 * the AGF lock, we can safely discard it without holding the AGF lock because
67 * nothing will attempt to allocate that free space until the discard completes.
68 *
69 * This also allows us to issue discards asynchronously like we do with online
70 * discard, and so for fast devices fstrim will run much faster as we can have
71 * multiple discard operations in flight at once, as well as pipeline the free
72 * extent search so that it overlaps in flight discard IO.
73 */
74
75 struct workqueue_struct *xfs_discard_wq;
76
77 static void
78 xfs_discard_endio_work(
79 struct work_struct *work)
80 {
81 struct xfs_busy_extents *extents =
82 container_of(work, struct xfs_busy_extents, endio_work);
83
84 xfs_extent_busy_clear(extents->mount, &extents->extent_list, false);
85 kfree(extents->owner);
86 }
87
88 /*
89 * Queue up the actual completion to a thread to avoid IRQ-safe locking for
90 * pagb_lock.
91 */
92 static void
93 xfs_discard_endio(
94 struct bio *bio)
95 {
96 struct xfs_busy_extents *extents = bio->bi_private;
97
98 INIT_WORK(&extents->endio_work, xfs_discard_endio_work);
99 queue_work(xfs_discard_wq, &extents->endio_work);
100 bio_put(bio);
101 }
102
103 /*
104 * Walk the discard list and issue discards on all the busy extents in the
105 * list. We plug and chain the bios so that we only need a single completion
106 * call to clear all the busy extents once the discards are complete.
107 */
108 int
109 xfs_discard_extents(
110 struct xfs_mount *mp,
111 struct xfs_busy_extents *extents)
112 {
113 struct xfs_extent_busy *busyp;
114 struct bio *bio = NULL;
115 struct blk_plug plug;
116 int error = 0;
117
118 blk_start_plug(&plug);
119 list_for_each_entry(busyp, &extents->extent_list, list) {
120 trace_xfs_discard_extent(mp, busyp->agno, busyp->bno,
121 busyp->length);
122
123 error = __blkdev_issue_discard(mp->m_ddev_targp->bt_bdev,
124 XFS_AGB_TO_DADDR(mp, busyp->agno, busyp->bno),
125 XFS_FSB_TO_BB(mp, busyp->length),
126 GFP_KERNEL, &bio);
127 if (error && error != -EOPNOTSUPP) {
128 xfs_info(mp,
129 "discard failed for extent [0x%llx,%u], error %d",
130 (unsigned long long)busyp->bno,
131 busyp->length,
132 error);
133 break;
134 }
135 }
136
137 if (bio) {
138 bio->bi_private = extents;
139 bio->bi_end_io = xfs_discard_endio;
140 submit_bio(bio);
141 } else {
142 xfs_discard_endio_work(&extents->endio_work);
143 }
144 blk_finish_plug(&plug);
145
146 return error;
147 }
148
149 struct xfs_trim_cur {
150 xfs_agblock_t start;
151 xfs_extlen_t count;
152 xfs_agblock_t end;
153 xfs_extlen_t minlen;
154 bool by_bno;
155 };
156
157 static int
158 xfs_trim_gather_extents(
159 struct xfs_perag *pag,
160 struct xfs_trim_cur *tcur,
161 struct xfs_busy_extents *extents)
162 {
163 struct xfs_mount *mp = pag->pag_mount;
164 struct xfs_trans *tp;
165 struct xfs_btree_cur *cur;
166 struct xfs_buf *agbp;
167 int error;
168 int i;
169 int batch = 100;
170
171 /*
172 * Force out the log. This means any transactions that might have freed
173 * space before we take the AGF buffer lock are now on disk, and the
174 * volatile disk cache is flushed.
175 */
176 xfs_log_force(mp, XFS_LOG_SYNC);
177
178 error = xfs_trans_alloc_empty(mp, &tp);
179 if (error)
180 return error;
181
182 error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
183 if (error)
184 goto out_trans_cancel;
185
186 if (tcur->by_bno) {
187 /* sub-AG discard request always starts at tcur->start */
188 cur = xfs_bnobt_init_cursor(mp, tp, agbp, pag);
189 error = xfs_alloc_lookup_le(cur, tcur->start, 0, &i);
190 if (!error && !i)
191 error = xfs_alloc_lookup_ge(cur, tcur->start, 0, &i);
192 } else if (tcur->start == 0) {
193 /* first time through a by-len starts with max length */
194 cur = xfs_cntbt_init_cursor(mp, tp, agbp, pag);
195 error = xfs_alloc_lookup_ge(cur, 0, tcur->count, &i);
196 } else {
197 /* nth time through a by-len starts where we left off */
198 cur = xfs_cntbt_init_cursor(mp, tp, agbp, pag);
199 error = xfs_alloc_lookup_le(cur, tcur->start, tcur->count, &i);
200 }
201 if (error)
202 goto out_del_cursor;
203 if (i == 0) {
204 /* nothing of that length left in the AG, we are done */
205 tcur->count = 0;
206 goto out_del_cursor;
207 }
208
209 /*
210 * Loop until we are done with all extents that are large
211 * enough to be worth discarding or we hit batch limits.
212 */
213 while (i) {
214 xfs_agblock_t fbno;
215 xfs_extlen_t flen;
216
217 error = xfs_alloc_get_rec(cur, &fbno, &flen, &i);
218 if (error)
219 break;
220 if (XFS_IS_CORRUPT(mp, i != 1)) {
221 xfs_btree_mark_sick(cur);
222 error = -EFSCORRUPTED;
223 break;
224 }
225
226 if (--batch <= 0) {
227 /*
228 * Update the cursor to point at this extent so we
229 * restart the next batch from this extent.
230 */
231 tcur->start = fbno;
232 tcur->count = flen;
233 break;
234 }
235
236 /*
237 * If the extent is entirely outside of the range we are
238 * supposed to skip it. Do not bother to trim down partially
239 * overlapping ranges for now.
240 */
241 if (fbno + flen < tcur->start) {
242 trace_xfs_discard_exclude(mp, pag->pag_agno, fbno, flen);
243 goto next_extent;
244 }
245 if (fbno > tcur->end) {
246 trace_xfs_discard_exclude(mp, pag->pag_agno, fbno, flen);
247 if (tcur->by_bno) {
248 tcur->count = 0;
249 break;
250 }
251 goto next_extent;
252 }
253
254 /* Trim the extent returned to the range we want. */
255 if (fbno < tcur->start) {
256 flen -= tcur->start - fbno;
257 fbno = tcur->start;
258 }
259 if (fbno + flen > tcur->end + 1)
260 flen = tcur->end - fbno + 1;
261
262 /* Too small? Give up. */
263 if (flen < tcur->minlen) {
264 trace_xfs_discard_toosmall(mp, pag->pag_agno, fbno, flen);
265 if (tcur->by_bno)
266 goto next_extent;
267 tcur->count = 0;
268 break;
269 }
270
271 /*
272 * If any blocks in the range are still busy, skip the
273 * discard and try again the next time.
274 */
275 if (xfs_extent_busy_search(mp, pag, fbno, flen)) {
276 trace_xfs_discard_busy(mp, pag->pag_agno, fbno, flen);
277 goto next_extent;
278 }
279
280 xfs_extent_busy_insert_discard(pag, fbno, flen,
281 &extents->extent_list);
282 next_extent:
283 if (tcur->by_bno)
284 error = xfs_btree_increment(cur, 0, &i);
285 else
286 error = xfs_btree_decrement(cur, 0, &i);
287 if (error)
288 break;
289
290 /*
291 * If there's no more records in the tree, we are done. Set the
292 * cursor block count to 0 to indicate to the caller that there
293 * is no more extents to search.
294 */
295 if (i == 0)
296 tcur->count = 0;
297 }
298
299 /*
300 * If there was an error, release all the gathered busy extents because
301 * we aren't going to issue a discard on them any more.
302 */
303 if (error)
304 xfs_extent_busy_clear(mp, &extents->extent_list, false);
305 out_del_cursor:
306 xfs_btree_del_cursor(cur, error);
307 out_trans_cancel:
308 xfs_trans_cancel(tp);
309 return error;
310 }
311
312 static bool
313 xfs_trim_should_stop(void)
314 {
315 return fatal_signal_pending(current) || freezing(current);
316 }
317
318 /*
319 * Iterate the free list gathering extents and discarding them. We need a cursor
320 * for the repeated iteration of gather/discard loop, so use the longest extent
321 * we found in the last batch as the key to start the next.
322 */
323 static int
324 xfs_trim_perag_extents(
325 struct xfs_perag *pag,
326 xfs_agblock_t start,
327 xfs_agblock_t end,
328 xfs_extlen_t minlen)
329 {
330 struct xfs_trim_cur tcur = {
331 .start = start,
332 .count = pag->pagf_longest,
333 .end = end,
334 .minlen = minlen,
335 };
336 int error = 0;
337
338 if (start != 0 || end != pag->block_count)
339 tcur.by_bno = true;
340
341 do {
342 struct xfs_busy_extents *extents;
343
344 extents = kzalloc(sizeof(*extents), GFP_KERNEL);
345 if (!extents) {
346 error = -ENOMEM;
347 break;
348 }
349
350 extents->mount = pag->pag_mount;
351 extents->owner = extents;
352 INIT_LIST_HEAD(&extents->extent_list);
353
354 error = xfs_trim_gather_extents(pag, &tcur, extents);
355 if (error) {
356 kfree(extents);
357 break;
358 }
359
360 /*
361 * We hand the extent list to the discard function here so the
362 * discarded extents can be removed from the busy extent list.
363 * This allows the discards to run asynchronously with gathering
364 * the next round of extents to discard.
365 *
366 * However, we must ensure that we do not reference the extent
367 * list after this function call, as it may have been freed by
368 * the time control returns to us.
369 */
370 error = xfs_discard_extents(pag->pag_mount, extents);
371 if (error)
372 break;
373
374 if (xfs_trim_should_stop())
375 break;
376
377 } while (tcur.count != 0);
378
379 return error;
380
381 }
382
383 static int
384 xfs_trim_datadev_extents(
385 struct xfs_mount *mp,
386 xfs_daddr_t start,
387 xfs_daddr_t end,
388 xfs_extlen_t minlen)
389 {
390 xfs_agnumber_t start_agno, end_agno;
391 xfs_agblock_t start_agbno, end_agbno;
392 xfs_daddr_t ddev_end;
393 struct xfs_perag *pag;
394 int last_error = 0, error;
395
396 ddev_end = min_t(xfs_daddr_t, end,
397 XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1);
398
399 start_agno = xfs_daddr_to_agno(mp, start);
400 start_agbno = xfs_daddr_to_agbno(mp, start);
401 end_agno = xfs_daddr_to_agno(mp, ddev_end);
402 end_agbno = xfs_daddr_to_agbno(mp, ddev_end);
403
404 for_each_perag_range(mp, start_agno, end_agno, pag) {
405 xfs_agblock_t agend = pag->block_count;
406
407 if (start_agno == end_agno)
408 agend = end_agbno;
409 error = xfs_trim_perag_extents(pag, start_agbno, agend, minlen);
410 if (error)
411 last_error = error;
412
413 if (xfs_trim_should_stop()) {
414 xfs_perag_rele(pag);
415 break;
416 }
417 start_agbno = 0;
418 }
419
420 return last_error;
421 }
422
423 #ifdef CONFIG_XFS_RT
424 struct xfs_trim_rtdev {
425 /* list of rt extents to free */
426 struct list_head extent_list;
427
428 /* minimum length that caller allows us to trim */
429 xfs_rtblock_t minlen_fsb;
430
431 /* restart point for the rtbitmap walk */
432 xfs_rtxnum_t restart_rtx;
433
434 /* stopping point for the current rtbitmap walk */
435 xfs_rtxnum_t stop_rtx;
436 };
437
438 struct xfs_rtx_busy {
439 struct list_head list;
440 xfs_rtblock_t bno;
441 xfs_rtblock_t length;
442 };
443
444 static void
445 xfs_discard_free_rtdev_extents(
446 struct xfs_trim_rtdev *tr)
447 {
448 struct xfs_rtx_busy *busyp, *n;
449
450 list_for_each_entry_safe(busyp, n, &tr->extent_list, list) {
451 list_del_init(&busyp->list);
452 kfree(busyp);
453 }
454 }
455
456 /*
457 * Walk the discard list and issue discards on all the busy extents in the
458 * list. We plug and chain the bios so that we only need a single completion
459 * call to clear all the busy extents once the discards are complete.
460 */
461 static int
462 xfs_discard_rtdev_extents(
463 struct xfs_mount *mp,
464 struct xfs_trim_rtdev *tr)
465 {
466 struct block_device *bdev = mp->m_rtdev_targp->bt_bdev;
467 struct xfs_rtx_busy *busyp;
468 struct bio *bio = NULL;
469 struct blk_plug plug;
470 xfs_rtblock_t start = NULLRTBLOCK, length = 0;
471 int error = 0;
472
473 blk_start_plug(&plug);
474 list_for_each_entry(busyp, &tr->extent_list, list) {
475 if (start == NULLRTBLOCK)
476 start = busyp->bno;
477 length += busyp->length;
478
479 trace_xfs_discard_rtextent(mp, busyp->bno, busyp->length);
480
481 error = __blkdev_issue_discard(bdev,
482 XFS_FSB_TO_BB(mp, busyp->bno),
483 XFS_FSB_TO_BB(mp, busyp->length),
484 GFP_NOFS, &bio);
485 if (error)
486 break;
487 }
488 xfs_discard_free_rtdev_extents(tr);
489
490 if (bio) {
491 error = submit_bio_wait(bio);
492 if (error == -EOPNOTSUPP)
493 error = 0;
494 if (error)
495 xfs_info(mp,
496 "discard failed for rtextent [0x%llx,%llu], error %d",
497 (unsigned long long)start,
498 (unsigned long long)length,
499 error);
500 bio_put(bio);
501 }
502 blk_finish_plug(&plug);
503
504 return error;
505 }
506
507 static int
508 xfs_trim_gather_rtextent(
509 struct xfs_mount *mp,
510 struct xfs_trans *tp,
511 const struct xfs_rtalloc_rec *rec,
512 void *priv)
513 {
514 struct xfs_trim_rtdev *tr = priv;
515 struct xfs_rtx_busy *busyp;
516 xfs_rtblock_t rbno, rlen;
517
518 if (rec->ar_startext > tr->stop_rtx) {
519 /*
520 * If we've scanned a large number of rtbitmap blocks, update
521 * the cursor to point at this extent so we restart the next
522 * batch from this extent.
523 */
524 tr->restart_rtx = rec->ar_startext;
525 return -ECANCELED;
526 }
527
528 rbno = xfs_rtx_to_rtb(mp, rec->ar_startext);
529 rlen = xfs_rtx_to_rtb(mp, rec->ar_extcount);
530
531 /* Ignore too small. */
532 if (rlen < tr->minlen_fsb) {
533 trace_xfs_discard_rttoosmall(mp, rbno, rlen);
534 return 0;
535 }
536
537 busyp = kzalloc(sizeof(struct xfs_rtx_busy), GFP_KERNEL);
538 if (!busyp)
539 return -ENOMEM;
540
541 busyp->bno = rbno;
542 busyp->length = rlen;
543 INIT_LIST_HEAD(&busyp->list);
544 list_add_tail(&busyp->list, &tr->extent_list);
545
546 tr->restart_rtx = rec->ar_startext + rec->ar_extcount;
547 return 0;
548 }
549
550 static int
551 xfs_trim_rtdev_extents(
552 struct xfs_mount *mp,
553 xfs_daddr_t start,
554 xfs_daddr_t end,
555 xfs_daddr_t minlen)
556 {
557 struct xfs_rtalloc_rec low = { };
558 struct xfs_rtalloc_rec high = { };
559 struct xfs_trim_rtdev tr = {
560 .minlen_fsb = XFS_BB_TO_FSB(mp, minlen),
561 };
562 struct xfs_trans *tp;
563 xfs_daddr_t rtdev_daddr;
564 int error;
565
566 INIT_LIST_HEAD(&tr.extent_list);
567
568 /* Shift the start and end downwards to match the rt device. */
569 rtdev_daddr = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
570 if (start > rtdev_daddr)
571 start -= rtdev_daddr;
572 else
573 start = 0;
574
575 if (end <= rtdev_daddr)
576 return 0;
577 end -= rtdev_daddr;
578
579 error = xfs_trans_alloc_empty(mp, &tp);
580 if (error)
581 return error;
582
583 end = min_t(xfs_daddr_t, end,
584 XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks) - 1);
585
586 /* Convert the rt blocks to rt extents */
587 low.ar_startext = xfs_rtb_to_rtxup(mp, XFS_BB_TO_FSB(mp, start));
588 high.ar_startext = xfs_rtb_to_rtx(mp, XFS_BB_TO_FSBT(mp, end));
589
590 /*
591 * Walk the free ranges between low and high. The query_range function
592 * trims the extents returned.
593 */
594 do {
595 tr.stop_rtx = low.ar_startext + (mp->m_sb.sb_blocksize * NBBY);
596 xfs_rtbitmap_lock_shared(mp, XFS_RBMLOCK_BITMAP);
597 error = xfs_rtalloc_query_range(mp, tp, &low, &high,
598 xfs_trim_gather_rtextent, &tr);
599
600 if (error == -ECANCELED)
601 error = 0;
602 if (error) {
603 xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
604 xfs_discard_free_rtdev_extents(&tr);
605 break;
606 }
607
608 if (list_empty(&tr.extent_list)) {
609 xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
610 break;
611 }
612
613 error = xfs_discard_rtdev_extents(mp, &tr);
614 xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
615 if (error)
616 break;
617
618 low.ar_startext = tr.restart_rtx;
619 } while (!xfs_trim_should_stop() && low.ar_startext <= high.ar_startext);
620
621 xfs_trans_cancel(tp);
622 return error;
623 }
624 #else
625 # define xfs_trim_rtdev_extents(...) (-EOPNOTSUPP)
626 #endif /* CONFIG_XFS_RT */
627
628 /*
629 * trim a range of the filesystem.
630 *
631 * Note: the parameters passed from userspace are byte ranges into the
632 * filesystem which does not match to the format we use for filesystem block
633 * addressing. FSB addressing is sparse (AGNO|AGBNO), while the incoming format
634 * is a linear address range. Hence we need to use DADDR based conversions and
635 * comparisons for determining the correct offset and regions to trim.
636 *
637 * The realtime device is mapped into the FITRIM "address space" immediately
638 * after the data device.
639 */
640 int
641 xfs_ioc_trim(
642 struct xfs_mount *mp,
643 struct fstrim_range __user *urange)
644 {
645 unsigned int granularity =
646 bdev_discard_granularity(mp->m_ddev_targp->bt_bdev);
647 struct block_device *rt_bdev = NULL;
648 struct fstrim_range range;
649 xfs_daddr_t start, end;
650 xfs_extlen_t minlen;
651 xfs_rfsblock_t max_blocks;
652 int error, last_error = 0;
653
654 if (!capable(CAP_SYS_ADMIN))
655 return -EPERM;
656 if (mp->m_rtdev_targp &&
657 bdev_max_discard_sectors(mp->m_rtdev_targp->bt_bdev))
658 rt_bdev = mp->m_rtdev_targp->bt_bdev;
659 if (!bdev_max_discard_sectors(mp->m_ddev_targp->bt_bdev) && !rt_bdev)
660 return -EOPNOTSUPP;
661
662 if (rt_bdev)
663 granularity = max(granularity,
664 bdev_discard_granularity(rt_bdev));
665
666 /*
667 * We haven't recovered the log, so we cannot use our bnobt-guided
668 * storage zapping commands.
669 */
670 if (xfs_has_norecovery(mp))
671 return -EROFS;
672
673 if (copy_from_user(&range, urange, sizeof(range)))
674 return -EFAULT;
675
676 range.minlen = max_t(u64, granularity, range.minlen);
677 minlen = XFS_B_TO_FSB(mp, range.minlen);
678
679 /*
680 * Truncating down the len isn't actually quite correct, but using
681 * BBTOB would mean we trivially get overflows for values
682 * of ULLONG_MAX or slightly lower. And ULLONG_MAX is the default
683 * used by the fstrim application. In the end it really doesn't
684 * matter as trimming blocks is an advisory interface.
685 */
686 max_blocks = mp->m_sb.sb_dblocks + mp->m_sb.sb_rblocks;
687 if (range.start >= XFS_FSB_TO_B(mp, max_blocks) ||
688 range.minlen > XFS_FSB_TO_B(mp, mp->m_ag_max_usable) ||
689 range.len < mp->m_sb.sb_blocksize)
690 return -EINVAL;
691
692 start = BTOBB(range.start);
693 end = start + BTOBBT(range.len) - 1;
694
695 if (bdev_max_discard_sectors(mp->m_ddev_targp->bt_bdev)) {
696 error = xfs_trim_datadev_extents(mp, start, end, minlen);
697 if (error)
698 last_error = error;
699 }
700
701 if (rt_bdev && !xfs_trim_should_stop()) {
702 error = xfs_trim_rtdev_extents(mp, start, end, minlen);
703 if (error)
704 last_error = error;
705 }
706
707 if (last_error)
708 return last_error;
709
710 range.len = min_t(unsigned long long, range.len,
711 XFS_FSB_TO_B(mp, max_blocks));
712 if (copy_to_user(urange, &range, sizeof(range)))
713 return -EFAULT;
714 return 0;
715 }
716
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.