1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_bit.h"
13#include "xfs_mount.h"
14#include "xfs_inode.h"
15#include "xfs_bmap.h"
16#include "xfs_bmap_btree.h"
17#include "xfs_bmap_util.h"
18#include "xfs_trans.h"
19#include "xfs_trans_space.h"
20#include "xfs_icache.h"
21#include "xfs_rtalloc.h"
22#include "xfs_sb.h"
23#include "xfs_rtbitmap.h"
24#include "xfs_quota.h"
25#include "xfs_log_priv.h"
26#include "xfs_health.h"
27
28/*
29 * Return whether there are any free extents in the size range given
30 * by low and high, for the bitmap block bbno.
31 */
32STATIC int
33xfs_rtany_summary(
34 struct xfs_rtalloc_args *args,
35 int low, /* low log2 extent size */
36 int high, /* high log2 extent size */
37 xfs_fileoff_t bbno, /* bitmap block number */
38 int *maxlog) /* out: max log2 extent size free */
39{
40 struct xfs_mount *mp = args->mp;
41 int error;
42 int log; /* loop counter, log2 of ext. size */
43 xfs_suminfo_t sum; /* summary data */
44
45 /* There are no extents at levels >= m_rsum_cache[bbno]. */
46 if (mp->m_rsum_cache) {
47 high = min(high, mp->m_rsum_cache[bbno] - 1);
48 if (low > high) {
49 *maxlog = -1;
50 return 0;
51 }
52 }
53
54 /*
55 * Loop over logs of extent sizes.
56 */
57 for (log = high; log >= low; log--) {
58 /*
59 * Get one summary datum.
60 */
61 error = xfs_rtget_summary(args, log, bbno, &sum);
62 if (error) {
63 return error;
64 }
65 /*
66 * If there are any, return success.
67 */
68 if (sum) {
69 *maxlog = log;
70 goto out;
71 }
72 }
73 /*
74 * Found nothing, return failure.
75 */
76 *maxlog = -1;
77out:
78 /* There were no extents at levels > log. */
79 if (mp->m_rsum_cache && log + 1 < mp->m_rsum_cache[bbno])
80 mp->m_rsum_cache[bbno] = log + 1;
81 return 0;
82}
83
84
85/*
86 * Copy and transform the summary file, given the old and new
87 * parameters in the mount structures.
88 */
89STATIC int
90xfs_rtcopy_summary(
91 struct xfs_rtalloc_args *oargs,
92 struct xfs_rtalloc_args *nargs)
93{
94 xfs_fileoff_t bbno; /* bitmap block number */
95 int error;
96 int log; /* summary level number (log length) */
97 xfs_suminfo_t sum; /* summary data */
98
99 for (log = oargs->mp->m_rsumlevels - 1; log >= 0; log--) {
100 for (bbno = oargs->mp->m_sb.sb_rbmblocks - 1;
101 (xfs_srtblock_t)bbno >= 0;
102 bbno--) {
103 error = xfs_rtget_summary(oargs, log, bbno, &sum);
104 if (error)
105 goto out;
106 if (sum == 0)
107 continue;
108 error = xfs_rtmodify_summary(oargs, log, bbno, -sum);
109 if (error)
110 goto out;
111 error = xfs_rtmodify_summary(nargs, log, bbno, sum);
112 if (error)
113 goto out;
114 ASSERT(sum > 0);
115 }
116 }
117 error = 0;
118out:
119 xfs_rtbuf_cache_relse(oargs);
120 return 0;
121}
122/*
123 * Mark an extent specified by start and len allocated.
124 * Updates all the summary information as well as the bitmap.
125 */
126STATIC int
127xfs_rtallocate_range(
128 struct xfs_rtalloc_args *args,
129 xfs_rtxnum_t start, /* start rtext to allocate */
130 xfs_rtxlen_t len) /* in/out: summary block number */
131{
132 struct xfs_mount *mp = args->mp;
133 xfs_rtxnum_t end; /* end of the allocated rtext */
134 int error;
135 xfs_rtxnum_t postblock = 0; /* first rtext allocated > end */
136 xfs_rtxnum_t preblock = 0; /* first rtext allocated < start */
137
138 end = start + len - 1;
139 /*
140 * Assume we're allocating out of the middle of a free extent.
141 * We need to find the beginning and end of the extent so we can
142 * properly update the summary.
143 */
144 error = xfs_rtfind_back(args, start, 0, &preblock);
145 if (error)
146 return error;
147
148 /*
149 * Find the next allocated block (end of free extent).
150 */
151 error = xfs_rtfind_forw(args, end, mp->m_sb.sb_rextents - 1,
152 &postblock);
153 if (error)
154 return error;
155
156 /*
157 * Decrement the summary information corresponding to the entire
158 * (old) free extent.
159 */
160 error = xfs_rtmodify_summary(args,
161 xfs_highbit64(postblock + 1 - preblock),
162 xfs_rtx_to_rbmblock(mp, preblock), -1);
163 if (error)
164 return error;
165
166 /*
167 * If there are blocks not being allocated at the front of the
168 * old extent, add summary data for them to be free.
169 */
170 if (preblock < start) {
171 error = xfs_rtmodify_summary(args,
172 xfs_highbit64(start - preblock),
173 xfs_rtx_to_rbmblock(mp, preblock), 1);
174 if (error)
175 return error;
176 }
177
178 /*
179 * If there are blocks not being allocated at the end of the
180 * old extent, add summary data for them to be free.
181 */
182 if (postblock > end) {
183 error = xfs_rtmodify_summary(args,
184 xfs_highbit64(postblock - end),
185 xfs_rtx_to_rbmblock(mp, end + 1), 1);
186 if (error)
187 return error;
188 }
189
190 /*
191 * Modify the bitmap to mark this extent allocated.
192 */
193 return xfs_rtmodify_range(args, start, len, 0);
194}
195
196/*
197 * Make sure we don't run off the end of the rt volume. Be careful that
198 * adjusting maxlen downwards doesn't cause us to fail the alignment checks.
199 */
200static inline xfs_rtxlen_t
201xfs_rtallocate_clamp_len(
202 struct xfs_mount *mp,
203 xfs_rtxnum_t startrtx,
204 xfs_rtxlen_t rtxlen,
205 xfs_rtxlen_t prod)
206{
207 xfs_rtxlen_t ret;
208
209 ret = min(mp->m_sb.sb_rextents, startrtx + rtxlen) - startrtx;
210 return rounddown(ret, prod);
211}
212
213/*
214 * Attempt to allocate an extent minlen<=len<=maxlen starting from
215 * bitmap block bbno. If we don't get maxlen then use prod to trim
216 * the length, if given. Returns error; returns starting block in *rtx.
217 * The lengths are all in rtextents.
218 */
219STATIC int
220xfs_rtallocate_extent_block(
221 struct xfs_rtalloc_args *args,
222 xfs_fileoff_t bbno, /* bitmap block number */
223 xfs_rtxlen_t minlen, /* minimum length to allocate */
224 xfs_rtxlen_t maxlen, /* maximum length to allocate */
225 xfs_rtxlen_t *len, /* out: actual length allocated */
226 xfs_rtxnum_t *nextp, /* out: next rtext to try */
227 xfs_rtxlen_t prod, /* extent product factor */
228 xfs_rtxnum_t *rtx) /* out: start rtext allocated */
229{
230 struct xfs_mount *mp = args->mp;
231 xfs_rtxnum_t besti; /* best rtext found so far */
232 xfs_rtxnum_t bestlen;/* best length found so far */
233 xfs_rtxnum_t end; /* last rtext in chunk */
234 int error;
235 xfs_rtxnum_t i; /* current rtext trying */
236 xfs_rtxnum_t next; /* next rtext to try */
237 int stat; /* status from internal calls */
238
239 /*
240 * Loop over all the extents starting in this bitmap block,
241 * looking for one that's long enough.
242 */
243 for (i = xfs_rbmblock_to_rtx(mp, bbno), besti = -1, bestlen = 0,
244 end = xfs_rbmblock_to_rtx(mp, bbno + 1) - 1;
245 i <= end;
246 i++) {
247 /* Make sure we don't scan off the end of the rt volume. */
248 maxlen = xfs_rtallocate_clamp_len(mp, i, maxlen, prod);
249
250 /*
251 * See if there's a free extent of maxlen starting at i.
252 * If it's not so then next will contain the first non-free.
253 */
254 error = xfs_rtcheck_range(args, i, maxlen, 1, &next, &stat);
255 if (error)
256 return error;
257 if (stat) {
258 /*
259 * i for maxlen is all free, allocate and return that.
260 */
261 bestlen = maxlen;
262 besti = i;
263 goto allocate;
264 }
265
266 /*
267 * In the case where we have a variable-sized allocation
268 * request, figure out how big this free piece is,
269 * and if it's big enough for the minimum, and the best
270 * so far, remember it.
271 */
272 if (minlen < maxlen) {
273 xfs_rtxnum_t thislen; /* this extent size */
274
275 thislen = next - i;
276 if (thislen >= minlen && thislen > bestlen) {
277 besti = i;
278 bestlen = thislen;
279 }
280 }
281 /*
282 * If not done yet, find the start of the next free space.
283 */
284 if (next >= end)
285 break;
286 error = xfs_rtfind_forw(args, next, end, &i);
287 if (error)
288 return error;
289 }
290
291 /*
292 * Searched the whole thing & didn't find a maxlen free extent.
293 */
294 if (minlen > maxlen || besti == -1) {
295 /*
296 * Allocation failed. Set *nextp to the next block to try.
297 */
298 *nextp = next;
299 return -ENOSPC;
300 }
301
302 /*
303 * If size should be a multiple of prod, make that so.
304 */
305 if (prod > 1) {
306 xfs_rtxlen_t p; /* amount to trim length by */
307
308 div_u64_rem(bestlen, prod, &p);
309 if (p)
310 bestlen -= p;
311 }
312
313 /*
314 * Allocate besti for bestlen & return that.
315 */
316allocate:
317 error = xfs_rtallocate_range(args, besti, bestlen);
318 if (error)
319 return error;
320 *len = bestlen;
321 *rtx = besti;
322 return 0;
323}
324
325/*
326 * Allocate an extent of length minlen<=len<=maxlen, starting at block
327 * bno. If we don't get maxlen then use prod to trim the length, if given.
328 * Returns error; returns starting block in *rtx.
329 * The lengths are all in rtextents.
330 */
331STATIC int
332xfs_rtallocate_extent_exact(
333 struct xfs_rtalloc_args *args,
334 xfs_rtxnum_t start, /* starting rtext number to allocate */
335 xfs_rtxlen_t minlen, /* minimum length to allocate */
336 xfs_rtxlen_t maxlen, /* maximum length to allocate */
337 xfs_rtxlen_t *len, /* out: actual length allocated */
338 xfs_rtxlen_t prod, /* extent product factor */
339 xfs_rtxnum_t *rtx) /* out: start rtext allocated */
340{
341 int error;
342 xfs_rtxlen_t i; /* extent length trimmed due to prod */
343 int isfree; /* extent is free */
344 xfs_rtxnum_t next; /* next rtext to try (dummy) */
345
346 ASSERT(minlen % prod == 0);
347 ASSERT(maxlen % prod == 0);
348 /*
349 * Check if the range in question (for maxlen) is free.
350 */
351 error = xfs_rtcheck_range(args, start, maxlen, 1, &next, &isfree);
352 if (error)
353 return error;
354
355 if (!isfree) {
356 /*
357 * If not, allocate what there is, if it's at least minlen.
358 */
359 maxlen = next - start;
360 if (maxlen < minlen)
361 return -ENOSPC;
362
363 /*
364 * Trim off tail of extent, if prod is specified.
365 */
366 if (prod > 1 && (i = maxlen % prod)) {
367 maxlen -= i;
368 if (maxlen < minlen)
369 return -ENOSPC;
370 }
371 }
372
373 /*
374 * Allocate what we can and return it.
375 */
376 error = xfs_rtallocate_range(args, start, maxlen);
377 if (error)
378 return error;
379 *len = maxlen;
380 *rtx = start;
381 return 0;
382}
383
384/*
385 * Allocate an extent of length minlen<=len<=maxlen, starting as near
386 * to start as possible. If we don't get maxlen then use prod to trim
387 * the length, if given. The lengths are all in rtextents.
388 */
389STATIC int
390xfs_rtallocate_extent_near(
391 struct xfs_rtalloc_args *args,
392 xfs_rtxnum_t start, /* starting rtext number to allocate */
393 xfs_rtxlen_t minlen, /* minimum length to allocate */
394 xfs_rtxlen_t maxlen, /* maximum length to allocate */
395 xfs_rtxlen_t *len, /* out: actual length allocated */
396 xfs_rtxlen_t prod, /* extent product factor */
397 xfs_rtxnum_t *rtx) /* out: start rtext allocated */
398{
399 struct xfs_mount *mp = args->mp;
400 int maxlog; /* max useful extent from summary */
401 xfs_fileoff_t bbno; /* bitmap block number */
402 int error;
403 int i; /* bitmap block offset (loop control) */
404 int j; /* secondary loop control */
405 int log2len; /* log2 of minlen */
406 xfs_rtxnum_t n; /* next rtext to try */
407
408 ASSERT(minlen % prod == 0);
409 ASSERT(maxlen % prod == 0);
410
411 /*
412 * If the block number given is off the end, silently set it to
413 * the last block.
414 */
415 if (start >= mp->m_sb.sb_rextents)
416 start = mp->m_sb.sb_rextents - 1;
417
418 /* Make sure we don't run off the end of the rt volume. */
419 maxlen = xfs_rtallocate_clamp_len(mp, start, maxlen, prod);
420 if (maxlen < minlen)
421 return -ENOSPC;
422
423 /*
424 * Try the exact allocation first.
425 */
426 error = xfs_rtallocate_extent_exact(args, start, minlen, maxlen, len,
427 prod, rtx);
428 if (error != -ENOSPC)
429 return error;
430
431
432 bbno = xfs_rtx_to_rbmblock(mp, start);
433 i = 0;
434 j = -1;
435 ASSERT(minlen != 0);
436 log2len = xfs_highbit32(minlen);
437 /*
438 * Loop over all bitmap blocks (bbno + i is current block).
439 */
440 for (;;) {
441 /*
442 * Get summary information of extents of all useful levels
443 * starting in this bitmap block.
444 */
445 error = xfs_rtany_summary(args, log2len, mp->m_rsumlevels - 1,
446 bbno + i, &maxlog);
447 if (error)
448 return error;
449
450 /*
451 * If there are any useful extents starting here, try
452 * allocating one.
453 */
454 if (maxlog >= 0) {
455 xfs_extlen_t maxavail =
456 min_t(xfs_rtblock_t, maxlen,
457 (1ULL << (maxlog + 1)) - 1);
458 /*
459 * On the positive side of the starting location.
460 */
461 if (i >= 0) {
462 /*
463 * Try to allocate an extent starting in
464 * this block.
465 */
466 error = xfs_rtallocate_extent_block(args,
467 bbno + i, minlen, maxavail, len,
468 &n, prod, rtx);
469 if (error != -ENOSPC)
470 return error;
471 }
472 /*
473 * On the negative side of the starting location.
474 */
475 else { /* i < 0 */
476 int maxblocks;
477
478 /*
479 * Loop backwards to find the end of the extent
480 * we found in the realtime summary.
481 *
482 * maxblocks is the maximum possible number of
483 * bitmap blocks from the start of the extent
484 * to the end of the extent.
485 */
486 if (maxlog == 0)
487 maxblocks = 0;
488 else if (maxlog < mp->m_blkbit_log)
489 maxblocks = 1;
490 else
491 maxblocks = 2 << (maxlog - mp->m_blkbit_log);
492
493 /*
494 * We need to check bbno + i + maxblocks down to
495 * bbno + i. We already checked bbno down to
496 * bbno + j + 1, so we don't need to check those
497 * again.
498 */
499 j = min(i + maxblocks, j);
500 for (; j >= i; j--) {
501 error = xfs_rtallocate_extent_block(args,
502 bbno + j, minlen,
503 maxavail, len, &n, prod,
504 rtx);
505 if (error != -ENOSPC)
506 return error;
507 }
508 }
509 }
510 /*
511 * Loop control. If we were on the positive side, and there's
512 * still more blocks on the negative side, go there.
513 */
514 if (i > 0 && (int)bbno - i >= 0)
515 i = -i;
516 /*
517 * If positive, and no more negative, but there are more
518 * positive, go there.
519 */
520 else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
521 i++;
522 /*
523 * If negative or 0 (just started), and there are positive
524 * blocks to go, go there. The 0 case moves to block 1.
525 */
526 else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
527 i = 1 - i;
528 /*
529 * If negative or 0 and there are more negative blocks,
530 * go there.
531 */
532 else if (i <= 0 && (int)bbno + i > 0)
533 i--;
534 /*
535 * Must be done. Return failure.
536 */
537 else
538 break;
539 }
540 return -ENOSPC;
541}
542
543static int
544xfs_rtalloc_sumlevel(
545 struct xfs_rtalloc_args *args,
546 int l, /* level number */
547 xfs_rtxlen_t minlen, /* minimum length to allocate */
548 xfs_rtxlen_t maxlen, /* maximum length to allocate */
549 xfs_rtxlen_t prod, /* extent product factor */
550 xfs_rtxlen_t *len, /* out: actual length allocated */
551 xfs_rtxnum_t *rtx) /* out: start rtext allocated */
552{
553 xfs_fileoff_t i; /* bitmap block number */
554
555 for (i = 0; i < args->mp->m_sb.sb_rbmblocks; i++) {
556 xfs_suminfo_t sum; /* summary information for extents */
557 xfs_rtxnum_t n; /* next rtext to be tried */
558 int error;
559
560 error = xfs_rtget_summary(args, l, i, &sum);
561 if (error)
562 return error;
563
564 /*
565 * Nothing there, on to the next block.
566 */
567 if (!sum)
568 continue;
569
570 /*
571 * Try allocating the extent.
572 */
573 error = xfs_rtallocate_extent_block(args, i, minlen, maxlen,
574 len, &n, prod, rtx);
575 if (error != -ENOSPC)
576 return error;
577
578 /*
579 * If the "next block to try" returned from the allocator is
580 * beyond the next bitmap block, skip to that bitmap block.
581 */
582 if (xfs_rtx_to_rbmblock(args->mp, n) > i + 1)
583 i = xfs_rtx_to_rbmblock(args->mp, n) - 1;
584 }
585
586 return -ENOSPC;
587}
588
589/*
590 * Allocate an extent of length minlen<=len<=maxlen, with no position
591 * specified. If we don't get maxlen then use prod to trim
592 * the length, if given. The lengths are all in rtextents.
593 */
594STATIC int
595xfs_rtallocate_extent_size(
596 struct xfs_rtalloc_args *args,
597 xfs_rtxlen_t minlen, /* minimum length to allocate */
598 xfs_rtxlen_t maxlen, /* maximum length to allocate */
599 xfs_rtxlen_t *len, /* out: actual length allocated */
600 xfs_rtxlen_t prod, /* extent product factor */
601 xfs_rtxnum_t *rtx) /* out: start rtext allocated */
602{
603 int error;
604 int l; /* level number (loop control) */
605
606 ASSERT(minlen % prod == 0);
607 ASSERT(maxlen % prod == 0);
608 ASSERT(maxlen != 0);
609
610 /*
611 * Loop over all the levels starting with maxlen.
612 *
613 * At each level, look at all the bitmap blocks, to see if there are
614 * extents starting there that are long enough (>= maxlen).
615 *
616 * Note, only on the initial level can the allocation fail if the
617 * summary says there's an extent.
618 */
619 for (l = xfs_highbit32(maxlen); l < args->mp->m_rsumlevels; l++) {
620 error = xfs_rtalloc_sumlevel(args, l, minlen, maxlen, prod, len,
621 rtx);
622 if (error != -ENOSPC)
623 return error;
624 }
625
626 /*
627 * Didn't find any maxlen blocks. Try smaller ones, unless we are
628 * looking for a fixed size extent.
629 */
630 if (minlen > --maxlen)
631 return -ENOSPC;
632 ASSERT(minlen != 0);
633 ASSERT(maxlen != 0);
634
635 /*
636 * Loop over sizes, from maxlen down to minlen.
637 *
638 * This time, when we do the allocations, allow smaller ones to succeed,
639 * but make sure the specified minlen/maxlen are in the possible range
640 * for this summary level.
641 */
642 for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
643 error = xfs_rtalloc_sumlevel(args, l,
644 max_t(xfs_rtxlen_t, minlen, 1 << l),
645 min_t(xfs_rtxlen_t, maxlen, (1 << (l + 1)) - 1),
646 prod, len, rtx);
647 if (error != -ENOSPC)
648 return error;
649 }
650
651 return -ENOSPC;
652}
653
654/*
655 * Allocate space to the bitmap or summary file, and zero it, for growfs.
656 */
657STATIC int
658xfs_growfs_rt_alloc(
659 struct xfs_mount *mp, /* file system mount point */
660 xfs_extlen_t oblocks, /* old count of blocks */
661 xfs_extlen_t nblocks, /* new count of blocks */
662 struct xfs_inode *ip) /* inode (bitmap/summary) */
663{
664 xfs_fileoff_t bno; /* block number in file */
665 struct xfs_buf *bp; /* temporary buffer for zeroing */
666 xfs_daddr_t d; /* disk block address */
667 int error; /* error return value */
668 xfs_fsblock_t fsbno; /* filesystem block for bno */
669 struct xfs_bmbt_irec map; /* block map output */
670 int nmap; /* number of block maps */
671 int resblks; /* space reservation */
672 enum xfs_blft buf_type;
673 struct xfs_trans *tp;
674
675 if (ip == mp->m_rsumip)
676 buf_type = XFS_BLFT_RTSUMMARY_BUF;
677 else
678 buf_type = XFS_BLFT_RTBITMAP_BUF;
679
680 /*
681 * Allocate space to the file, as necessary.
682 */
683 while (oblocks < nblocks) {
684 resblks = XFS_GROWFSRT_SPACE_RES(mp, nblocks - oblocks);
685 /*
686 * Reserve space & log for one extent added to the file.
687 */
688 error = xfs_trans_alloc(mp, resp: &M_RES(mp)->tr_growrtalloc, blocks: resblks,
689 rtextents: 0, flags: 0, tpp: &tp);
690 if (error)
691 return error;
692 /*
693 * Lock the inode.
694 */
695 xfs_ilock(ip, XFS_ILOCK_EXCL);
696 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
697
698 error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
699 XFS_IEXT_ADD_NOSPLIT_CNT);
700 if (error == -EFBIG)
701 error = xfs_iext_count_upgrade(tp, ip,
702 XFS_IEXT_ADD_NOSPLIT_CNT);
703 if (error)
704 goto out_trans_cancel;
705
706 /*
707 * Allocate blocks to the bitmap file.
708 */
709 nmap = 1;
710 error = xfs_bmapi_write(tp, ip, oblocks, nblocks - oblocks,
711 XFS_BMAPI_METADATA, 0, &map, &nmap);
712 if (!error && nmap < 1)
713 error = -ENOSPC;
714 if (error)
715 goto out_trans_cancel;
716 /*
717 * Free any blocks freed up in the transaction, then commit.
718 */
719 error = xfs_trans_commit(tp);
720 if (error)
721 return error;
722 /*
723 * Now we need to clear the allocated blocks.
724 * Do this one block per transaction, to keep it simple.
725 */
726 for (bno = map.br_startoff, fsbno = map.br_startblock;
727 bno < map.br_startoff + map.br_blockcount;
728 bno++, fsbno++) {
729 /*
730 * Reserve log for one block zeroing.
731 */
732 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtzero,
733 0, 0, 0, &tp);
734 if (error)
735 return error;
736 /*
737 * Lock the bitmap inode.
738 */
739 xfs_ilock(ip, XFS_ILOCK_EXCL);
740 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
741 /*
742 * Get a buffer for the block.
743 */
744 d = XFS_FSB_TO_DADDR(mp, fsbno);
745 error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
746 mp->m_bsize, 0, &bp);
747 if (error)
748 goto out_trans_cancel;
749
750 xfs_trans_buf_set_type(tp, bp, buf_type);
751 bp->b_ops = &xfs_rtbuf_ops;
752 memset(bp->b_addr, 0, mp->m_sb.sb_blocksize);
753 xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
754 /*
755 * Commit the transaction.
756 */
757 error = xfs_trans_commit(tp);
758 if (error)
759 return error;
760 }
761 /*
762 * Go on to the next extent, if any.
763 */
764 oblocks = map.br_startoff + map.br_blockcount;
765 }
766
767 return 0;
768
769out_trans_cancel:
770 xfs_trans_cancel(tp);
771 return error;
772}
773
774static void
775xfs_alloc_rsum_cache(
776 xfs_mount_t *mp, /* file system mount structure */
777 xfs_extlen_t rbmblocks) /* number of rt bitmap blocks */
778{
779 /*
780 * The rsum cache is initialized to the maximum value, which is
781 * trivially an upper bound on the maximum level with any free extents.
782 * We can continue without the cache if it couldn't be allocated.
783 */
784 mp->m_rsum_cache = kvmalloc(size: rbmblocks, GFP_KERNEL);
785 if (mp->m_rsum_cache)
786 memset(mp->m_rsum_cache, -1, rbmblocks);
787 else
788 xfs_warn(mp, "could not allocate realtime summary cache");
789}
790
791/*
792 * Visible (exported) functions.
793 */
794
795/*
796 * Grow the realtime area of the filesystem.
797 */
798int
799xfs_growfs_rt(
800 xfs_mount_t *mp, /* mount point for filesystem */
801 xfs_growfs_rt_t *in) /* growfs rt input struct */
802{
803 xfs_fileoff_t bmbno; /* bitmap block number */
804 struct xfs_buf *bp; /* temporary buffer */
805 int error; /* error return value */
806 xfs_mount_t *nmp; /* new (fake) mount structure */
807 xfs_rfsblock_t nrblocks; /* new number of realtime blocks */
808 xfs_extlen_t nrbmblocks; /* new number of rt bitmap blocks */
809 xfs_rtxnum_t nrextents; /* new number of realtime extents */
810 uint8_t nrextslog; /* new log2 of sb_rextents */
811 xfs_extlen_t nrsumblocks; /* new number of summary blocks */
812 uint nrsumlevels; /* new rt summary levels */
813 uint nrsumsize; /* new size of rt summary, bytes */
814 xfs_sb_t *nsbp; /* new superblock */
815 xfs_extlen_t rbmblocks; /* current number of rt bitmap blocks */
816 xfs_extlen_t rsumblocks; /* current number of rt summary blks */
817 xfs_sb_t *sbp; /* old superblock */
818 uint8_t *rsum_cache; /* old summary cache */
819
820 sbp = &mp->m_sb;
821
822 if (!capable(CAP_SYS_ADMIN))
823 return -EPERM;
824
825 /* Needs to have been mounted with an rt device. */
826 if (!XFS_IS_REALTIME_MOUNT(mp))
827 return -EINVAL;
828 /*
829 * Mount should fail if the rt bitmap/summary files don't load, but
830 * we'll check anyway.
831 */
832 if (!mp->m_rbmip || !mp->m_rsumip)
833 return -EINVAL;
834
835 /* Shrink not supported. */
836 if (in->newblocks <= sbp->sb_rblocks)
837 return -EINVAL;
838
839 /* Can only change rt extent size when adding rt volume. */
840 if (sbp->sb_rblocks > 0 && in->extsize != sbp->sb_rextsize)
841 return -EINVAL;
842
843 /* Range check the extent size. */
844 if (XFS_FSB_TO_B(mp, in->extsize) > XFS_MAX_RTEXTSIZE ||
845 XFS_FSB_TO_B(mp, in->extsize) < XFS_MIN_RTEXTSIZE)
846 return -EINVAL;
847
848 /* Unsupported realtime features. */
849 if (xfs_has_rmapbt(mp) || xfs_has_reflink(mp) || xfs_has_quota(mp))
850 return -EOPNOTSUPP;
851
852 nrblocks = in->newblocks;
853 error = xfs_sb_validate_fsb_count(sbp, nrblocks);
854 if (error)
855 return error;
856 /*
857 * Read in the last block of the device, make sure it exists.
858 */
859 error = xfs_buf_read_uncached(mp->m_rtdev_targp,
860 XFS_FSB_TO_BB(mp, nrblocks - 1),
861 XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
862 if (error)
863 return error;
864 xfs_buf_relse(bp);
865
866 /*
867 * Calculate new parameters. These are the final values to be reached.
868 */
869 nrextents = nrblocks;
870 do_div(nrextents, in->extsize);
871 if (!xfs_validate_rtextents(nrextents))
872 return -EINVAL;
873 nrbmblocks = xfs_rtbitmap_blockcount(mp, nrextents);
874 nrextslog = xfs_compute_rextslog(nrextents);
875 nrsumlevels = nrextslog + 1;
876 nrsumblocks = xfs_rtsummary_blockcount(mp, nrsumlevels, nrbmblocks);
877 nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
878 /*
879 * New summary size can't be more than half the size of
880 * the log. This prevents us from getting a log overflow,
881 * since we'll log basically the whole summary file at once.
882 */
883 if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1))
884 return -EINVAL;
885 /*
886 * Get the old block counts for bitmap and summary inodes.
887 * These can't change since other growfs callers are locked out.
888 */
889 rbmblocks = XFS_B_TO_FSB(mp, mp->m_rbmip->i_disk_size);
890 rsumblocks = XFS_B_TO_FSB(mp, mp->m_rsumip->i_disk_size);
891 /*
892 * Allocate space to the bitmap and summary files, as necessary.
893 */
894 error = xfs_growfs_rt_alloc(mp, rbmblocks, nrbmblocks, mp->m_rbmip);
895 if (error)
896 return error;
897 error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip);
898 if (error)
899 return error;
900
901 rsum_cache = mp->m_rsum_cache;
902 if (nrbmblocks != sbp->sb_rbmblocks)
903 xfs_alloc_rsum_cache(mp, nrbmblocks);
904
905 /*
906 * Allocate a new (fake) mount/sb.
907 */
908 nmp = kmalloc(size: sizeof(*nmp), GFP_KERNEL | __GFP_NOFAIL);
909 /*
910 * Loop over the bitmap blocks.
911 * We will do everything one bitmap block at a time.
912 * Skip the current block if it is exactly full.
913 * This also deals with the case where there were no rtextents before.
914 */
915 for (bmbno = sbp->sb_rbmblocks -
916 ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
917 bmbno < nrbmblocks;
918 bmbno++) {
919 struct xfs_rtalloc_args args = {
920 .mp = mp,
921 };
922 struct xfs_rtalloc_args nargs = {
923 .mp = nmp,
924 };
925 struct xfs_trans *tp;
926 xfs_rfsblock_t nrblocks_step;
927
928 *nmp = *mp;
929 nsbp = &nmp->m_sb;
930 /*
931 * Calculate new sb and mount fields for this round.
932 */
933 nsbp->sb_rextsize = in->extsize;
934 nmp->m_rtxblklog = -1; /* don't use shift or masking */
935 nsbp->sb_rbmblocks = bmbno + 1;
936 nrblocks_step = (bmbno + 1) * NBBY * nsbp->sb_blocksize *
937 nsbp->sb_rextsize;
938 nsbp->sb_rblocks = min(nrblocks, nrblocks_step);
939 nsbp->sb_rextents = xfs_rtb_to_rtx(nmp, nsbp->sb_rblocks);
940 ASSERT(nsbp->sb_rextents != 0);
941 nsbp->sb_rextslog = xfs_compute_rextslog(nsbp->sb_rextents);
942 nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
943 nrsumblocks = xfs_rtsummary_blockcount(mp, nrsumlevels,
944 nsbp->sb_rbmblocks);
945 nmp->m_rsumsize = nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
946 /* recompute growfsrt reservation from new rsumsize */
947 xfs_trans_resv_calc(nmp, &nmp->m_resv);
948
949 /*
950 * Start a transaction, get the log reservation.
951 */
952 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtfree, 0, 0, 0,
953 &tp);
954 if (error)
955 break;
956 args.tp = tp;
957 nargs.tp = tp;
958
959 /*
960 * Lock out other callers by grabbing the bitmap inode lock.
961 */
962 xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
963 xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
964 /*
965 * Update the bitmap inode's size ondisk and incore. We need
966 * to update the incore size so that inode inactivation won't
967 * punch what it thinks are "posteof" blocks.
968 */
969 mp->m_rbmip->i_disk_size =
970 nsbp->sb_rbmblocks * nsbp->sb_blocksize;
971 i_size_write(VFS_I(mp->m_rbmip), mp->m_rbmip->i_disk_size);
972 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
973 /*
974 * Get the summary inode into the transaction.
975 */
976 xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
977 xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
978 /*
979 * Update the summary inode's size. We need to update the
980 * incore size so that inode inactivation won't punch what it
981 * thinks are "posteof" blocks.
982 */
983 mp->m_rsumip->i_disk_size = nmp->m_rsumsize;
984 i_size_write(VFS_I(mp->m_rsumip), mp->m_rsumip->i_disk_size);
985 xfs_trans_log_inode(tp, mp->m_rsumip, XFS_ILOG_CORE);
986 /*
987 * Copy summary data from old to new sizes.
988 * Do this when the real size (not block-aligned) changes.
989 */
990 if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
991 mp->m_rsumlevels != nmp->m_rsumlevels) {
992 error = xfs_rtcopy_summary(&args, &nargs);
993 if (error)
994 goto error_cancel;
995 }
996 /*
997 * Update superblock fields.
998 */
999 if (nsbp->sb_rextsize != sbp->sb_rextsize)
1000 xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
1001 nsbp->sb_rextsize - sbp->sb_rextsize);
1002 if (nsbp->sb_rbmblocks != sbp->sb_rbmblocks)
1003 xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
1004 nsbp->sb_rbmblocks - sbp->sb_rbmblocks);
1005 if (nsbp->sb_rblocks != sbp->sb_rblocks)
1006 xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
1007 nsbp->sb_rblocks - sbp->sb_rblocks);
1008 if (nsbp->sb_rextents != sbp->sb_rextents)
1009 xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
1010 nsbp->sb_rextents - sbp->sb_rextents);
1011 if (nsbp->sb_rextslog != sbp->sb_rextslog)
1012 xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
1013 nsbp->sb_rextslog - sbp->sb_rextslog);
1014 /*
1015 * Free new extent.
1016 */
1017 error = xfs_rtfree_range(&nargs, sbp->sb_rextents,
1018 nsbp->sb_rextents - sbp->sb_rextents);
1019 xfs_rtbuf_cache_relse(&nargs);
1020 if (error) {
1021error_cancel:
1022 xfs_trans_cancel(tp);
1023 break;
1024 }
1025 /*
1026 * Mark more blocks free in the superblock.
1027 */
1028 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS,
1029 nsbp->sb_rextents - sbp->sb_rextents);
1030 /*
1031 * Update mp values into the real mp structure.
1032 */
1033 mp->m_rsumlevels = nrsumlevels;
1034 mp->m_rsumsize = nrsumsize;
1035 /* recompute growfsrt reservation from new rsumsize */
1036 xfs_trans_resv_calc(mp, &mp->m_resv);
1037
1038 error = xfs_trans_commit(tp);
1039 if (error)
1040 break;
1041
1042 /* Ensure the mount RT feature flag is now set. */
1043 mp->m_features |= XFS_FEAT_REALTIME;
1044 }
1045 if (error)
1046 goto out_free;
1047
1048 /* Update secondary superblocks now the physical grow has completed */
1049 error = xfs_update_secondary_sbs(mp);
1050
1051out_free:
1052 /*
1053 * Free the fake mp structure.
1054 */
1055 kfree(objp: nmp);
1056
1057 /*
1058 * If we had to allocate a new rsum_cache, we either need to free the
1059 * old one (if we succeeded) or free the new one and restore the old one
1060 * (if there was an error).
1061 */
1062 if (rsum_cache != mp->m_rsum_cache) {
1063 if (error) {
1064 kvfree(addr: mp->m_rsum_cache);
1065 mp->m_rsum_cache = rsum_cache;
1066 } else {
1067 kvfree(addr: rsum_cache);
1068 }
1069 }
1070
1071 return error;
1072}
1073
1074/*
1075 * Initialize realtime fields in the mount structure.
1076 */
1077int /* error */
1078xfs_rtmount_init(
1079 struct xfs_mount *mp) /* file system mount structure */
1080{
1081 struct xfs_buf *bp; /* buffer for last block of subvolume */
1082 struct xfs_sb *sbp; /* filesystem superblock copy in mount */
1083 xfs_daddr_t d; /* address of last block of subvolume */
1084 unsigned int rsumblocks;
1085 int error;
1086
1087 sbp = &mp->m_sb;
1088 if (sbp->sb_rblocks == 0)
1089 return 0;
1090 if (mp->m_rtdev_targp == NULL) {
1091 xfs_warn(mp,
1092 "Filesystem has a realtime volume, use rtdev=device option");
1093 return -ENODEV;
1094 }
1095 mp->m_rsumlevels = sbp->sb_rextslog + 1;
1096 rsumblocks = xfs_rtsummary_blockcount(mp, mp->m_rsumlevels,
1097 mp->m_sb.sb_rbmblocks);
1098 mp->m_rsumsize = XFS_FSB_TO_B(mp, rsumblocks);
1099 mp->m_rbmip = mp->m_rsumip = NULL;
1100 /*
1101 * Check that the realtime section is an ok size.
1102 */
1103 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
1104 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_rblocks) {
1105 xfs_warn(mp, "realtime mount -- %llu != %llu",
1106 (unsigned long long) XFS_BB_TO_FSB(mp, d),
1107 (unsigned long long) mp->m_sb.sb_rblocks);
1108 return -EFBIG;
1109 }
1110 error = xfs_buf_read_uncached(target: mp->m_rtdev_targp,
1111 daddr: d - XFS_FSB_TO_BB(mp, 1),
1112 numblks: XFS_FSB_TO_BB(mp, 1), flags: 0, bpp: &bp, NULL);
1113 if (error) {
1114 xfs_warn(mp, "realtime device size check failed");
1115 return error;
1116 }
1117 xfs_buf_relse(bp);
1118 return 0;
1119}
1120
1121static int
1122xfs_rtalloc_count_frextent(
1123 struct xfs_mount *mp,
1124 struct xfs_trans *tp,
1125 const struct xfs_rtalloc_rec *rec,
1126 void *priv)
1127{
1128 uint64_t *valp = priv;
1129
1130 *valp += rec->ar_extcount;
1131 return 0;
1132}
1133
1134/*
1135 * Reinitialize the number of free realtime extents from the realtime bitmap.
1136 * Callers must ensure that there is no other activity in the filesystem.
1137 */
1138int
1139xfs_rtalloc_reinit_frextents(
1140 struct xfs_mount *mp)
1141{
1142 uint64_t val = 0;
1143 int error;
1144
1145 xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
1146 error = xfs_rtalloc_query_all(mp, NULL, xfs_rtalloc_count_frextent,
1147 &val);
1148 xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
1149 if (error)
1150 return error;
1151
1152 spin_lock(lock: &mp->m_sb_lock);
1153 mp->m_sb.sb_frextents = val;
1154 spin_unlock(lock: &mp->m_sb_lock);
1155 percpu_counter_set(fbc: &mp->m_frextents, amount: mp->m_sb.sb_frextents);
1156 return 0;
1157}
1158
1159/*
1160 * Read in the bmbt of an rt metadata inode so that we never have to load them
1161 * at runtime. This enables the use of shared ILOCKs for rtbitmap scans. Use
1162 * an empty transaction to avoid deadlocking on loops in the bmbt.
1163 */
1164static inline int
1165xfs_rtmount_iread_extents(
1166 struct xfs_inode *ip,
1167 unsigned int lock_class)
1168{
1169 struct xfs_trans *tp;
1170 int error;
1171
1172 error = xfs_trans_alloc_empty(mp: ip->i_mount, tpp: &tp);
1173 if (error)
1174 return error;
1175
1176 xfs_ilock(ip, XFS_ILOCK_EXCL | lock_class);
1177
1178 error = xfs_iread_extents(tp, ip, XFS_DATA_FORK);
1179 if (error)
1180 goto out_unlock;
1181
1182 if (xfs_inode_has_attr_fork(ip)) {
1183 error = xfs_iread_extents(tp, ip, XFS_ATTR_FORK);
1184 if (error)
1185 goto out_unlock;
1186 }
1187
1188out_unlock:
1189 xfs_iunlock(ip, XFS_ILOCK_EXCL | lock_class);
1190 xfs_trans_cancel(tp);
1191 return error;
1192}
1193
1194/*
1195 * Get the bitmap and summary inodes and the summary cache into the mount
1196 * structure at mount time.
1197 */
1198int /* error */
1199xfs_rtmount_inodes(
1200 xfs_mount_t *mp) /* file system mount structure */
1201{
1202 int error; /* error return value */
1203 xfs_sb_t *sbp;
1204
1205 sbp = &mp->m_sb;
1206 error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip);
1207 if (xfs_metadata_is_sick(error))
1208 xfs_rt_mark_sick(mp, XFS_SICK_RT_BITMAP);
1209 if (error)
1210 return error;
1211 ASSERT(mp->m_rbmip != NULL);
1212
1213 error = xfs_rtmount_iread_extents(ip: mp->m_rbmip, XFS_ILOCK_RTBITMAP);
1214 if (error)
1215 goto out_rele_bitmap;
1216
1217 error = xfs_iget(mp, NULL, sbp->sb_rsumino, 0, 0, &mp->m_rsumip);
1218 if (xfs_metadata_is_sick(error))
1219 xfs_rt_mark_sick(mp, XFS_SICK_RT_SUMMARY);
1220 if (error)
1221 goto out_rele_bitmap;
1222 ASSERT(mp->m_rsumip != NULL);
1223
1224 error = xfs_rtmount_iread_extents(ip: mp->m_rsumip, XFS_ILOCK_RTSUM);
1225 if (error)
1226 goto out_rele_summary;
1227
1228 xfs_alloc_rsum_cache(mp, sbp->sb_rbmblocks);
1229 return 0;
1230
1231out_rele_summary:
1232 xfs_irele(ip: mp->m_rsumip);
1233out_rele_bitmap:
1234 xfs_irele(ip: mp->m_rbmip);
1235 return error;
1236}
1237
1238void
1239xfs_rtunmount_inodes(
1240 struct xfs_mount *mp)
1241{
1242 kvfree(addr: mp->m_rsum_cache);
1243 if (mp->m_rbmip)
1244 xfs_irele(ip: mp->m_rbmip);
1245 if (mp->m_rsumip)
1246 xfs_irele(ip: mp->m_rsumip);
1247}
1248
1249/*
1250 * Pick an extent for allocation at the start of a new realtime file.
1251 * Use the sequence number stored in the atime field of the bitmap inode.
1252 * Translate this to a fraction of the rtextents, and return the product
1253 * of rtextents and the fraction.
1254 * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
1255 */
1256static int
1257xfs_rtpick_extent(
1258 xfs_mount_t *mp, /* file system mount point */
1259 xfs_trans_t *tp, /* transaction pointer */
1260 xfs_rtxlen_t len, /* allocation length (rtextents) */
1261 xfs_rtxnum_t *pick) /* result rt extent */
1262{
1263 xfs_rtxnum_t b; /* result rtext */
1264 int log2; /* log of sequence number */
1265 uint64_t resid; /* residual after log removed */
1266 uint64_t seq; /* sequence number of file creation */
1267 struct timespec64 ts; /* timespec in inode */
1268
1269 xfs_assert_ilocked(mp->m_rbmip, XFS_ILOCK_EXCL);
1270
1271 ts = inode_get_atime(inode: VFS_I(ip: mp->m_rbmip));
1272 if (!(mp->m_rbmip->i_diflags & XFS_DIFLAG_NEWRTBM)) {
1273 mp->m_rbmip->i_diflags |= XFS_DIFLAG_NEWRTBM;
1274 seq = 0;
1275 } else {
1276 seq = ts.tv_sec;
1277 }
1278 if ((log2 = xfs_highbit64(seq)) == -1)
1279 b = 0;
1280 else {
1281 resid = seq - (1ULL << log2);
1282 b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >>
1283 (log2 + 1);
1284 if (b >= mp->m_sb.sb_rextents)
1285 div64_u64_rem(b, mp->m_sb.sb_rextents, &b);
1286 if (b + len > mp->m_sb.sb_rextents)
1287 b = mp->m_sb.sb_rextents - len;
1288 }
1289 ts.tv_sec = seq + 1;
1290 inode_set_atime_to_ts(inode: VFS_I(ip: mp->m_rbmip), ts);
1291 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1292 *pick = b;
1293 return 0;
1294}
1295
1296static void
1297xfs_rtalloc_align_minmax(
1298 xfs_rtxlen_t *raminlen,
1299 xfs_rtxlen_t *ramaxlen,
1300 xfs_rtxlen_t *prod)
1301{
1302 xfs_rtxlen_t newmaxlen = *ramaxlen;
1303 xfs_rtxlen_t newminlen = *raminlen;
1304 xfs_rtxlen_t slack;
1305
1306 slack = newmaxlen % *prod;
1307 if (slack)
1308 newmaxlen -= slack;
1309 slack = newminlen % *prod;
1310 if (slack)
1311 newminlen += *prod - slack;
1312
1313 /*
1314 * If adjusting for extent size hint alignment produces an invalid
1315 * min/max len combination, go ahead without it.
1316 */
1317 if (newmaxlen < newminlen) {
1318 *prod = 1;
1319 return;
1320 }
1321 *ramaxlen = newmaxlen;
1322 *raminlen = newminlen;
1323}
1324
1325int
1326xfs_bmap_rtalloc(
1327 struct xfs_bmalloca *ap)
1328{
1329 struct xfs_mount *mp = ap->ip->i_mount;
1330 xfs_fileoff_t orig_offset = ap->offset;
1331 xfs_rtxnum_t start; /* allocation hint rtextent no */
1332 xfs_rtxnum_t rtx; /* actually allocated rtextent no */
1333 xfs_rtxlen_t prod = 0; /* product factor for allocators */
1334 xfs_extlen_t mod = 0; /* product factor for allocators */
1335 xfs_rtxlen_t ralen = 0; /* realtime allocation length */
1336 xfs_extlen_t align; /* minimum allocation alignment */
1337 xfs_extlen_t orig_length = ap->length;
1338 xfs_extlen_t minlen = mp->m_sb.sb_rextsize;
1339 xfs_rtxlen_t raminlen;
1340 bool rtlocked = false;
1341 bool ignore_locality = false;
1342 struct xfs_rtalloc_args args = {
1343 .mp = mp,
1344 .tp = ap->tp,
1345 };
1346 int error;
1347
1348 align = xfs_get_extsz_hint(ap->ip);
1349retry:
1350 error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
1351 align, 1, ap->eof, 0,
1352 ap->conv, &ap->offset, &ap->length);
1353 if (error)
1354 return error;
1355 ASSERT(ap->length);
1356 ASSERT(xfs_extlen_to_rtxmod(mp, ap->length) == 0);
1357
1358 /*
1359 * If we shifted the file offset downward to satisfy an extent size
1360 * hint, increase minlen by that amount so that the allocator won't
1361 * give us an allocation that's too short to cover at least one of the
1362 * blocks that the caller asked for.
1363 */
1364 if (ap->offset != orig_offset)
1365 minlen += orig_offset - ap->offset;
1366
1367 /*
1368 * Set ralen to be the actual requested length in rtextents.
1369 *
1370 * If the old value was close enough to XFS_BMBT_MAX_EXTLEN that
1371 * we rounded up to it, cut it back so it's valid again.
1372 * Note that if it's a really large request (bigger than
1373 * XFS_BMBT_MAX_EXTLEN), we don't hear about that number, and can't
1374 * adjust the starting point to match it.
1375 */
1376 ralen = xfs_extlen_to_rtxlen(mp, min(ap->length, XFS_MAX_BMBT_EXTLEN));
1377 raminlen = max_t(xfs_rtxlen_t, 1, xfs_extlen_to_rtxlen(mp, minlen));
1378 ASSERT(raminlen > 0);
1379 ASSERT(raminlen <= ralen);
1380
1381 /*
1382 * Lock out modifications to both the RT bitmap and summary inodes
1383 */
1384 if (!rtlocked) {
1385 xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
1386 xfs_trans_ijoin(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL);
1387 xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
1388 xfs_trans_ijoin(ap->tp, mp->m_rsumip, XFS_ILOCK_EXCL);
1389 rtlocked = true;
1390 }
1391
1392 if (ignore_locality) {
1393 start = 0;
1394 } else if (xfs_bmap_adjacent(ap)) {
1395 start = xfs_rtb_to_rtx(mp, ap->blkno);
1396 } else if (ap->eof && ap->offset == 0) {
1397 /*
1398 * If it's an allocation to an empty file at offset 0, pick an
1399 * extent that will space things out in the rt area.
1400 */
1401 error = xfs_rtpick_extent(mp, ap->tp, ralen, &start);
1402 if (error)
1403 return error;
1404 } else {
1405 start = 0;
1406 }
1407
1408 /*
1409 * Only bother calculating a real prod factor if offset & length are
1410 * perfectly aligned, otherwise it will just get us in trouble.
1411 */
1412 div_u64_rem(ap->offset, align, &mod);
1413 if (mod || ap->length % align) {
1414 prod = 1;
1415 } else {
1416 prod = xfs_extlen_to_rtxlen(mp, align);
1417 if (prod > 1)
1418 xfs_rtalloc_align_minmax(&raminlen, &ralen, &prod);
1419 }
1420
1421 if (start) {
1422 error = xfs_rtallocate_extent_near(&args, start, raminlen,
1423 ralen, &ralen, prod, &rtx);
1424 } else {
1425 error = xfs_rtallocate_extent_size(&args, raminlen,
1426 ralen, &ralen, prod, &rtx);
1427 }
1428 xfs_rtbuf_cache_relse(&args);
1429
1430 if (error == -ENOSPC) {
1431 if (align > mp->m_sb.sb_rextsize) {
1432 /*
1433 * We previously enlarged the request length to try to
1434 * satisfy an extent size hint. The allocator didn't
1435 * return anything, so reset the parameters to the
1436 * original values and try again without alignment
1437 * criteria.
1438 */
1439 ap->offset = orig_offset;
1440 ap->length = orig_length;
1441 minlen = align = mp->m_sb.sb_rextsize;
1442 goto retry;
1443 }
1444
1445 if (!ignore_locality && start != 0) {
1446 /*
1447 * If we can't allocate near a specific rt extent, try
1448 * again without locality criteria.
1449 */
1450 ignore_locality = true;
1451 goto retry;
1452 }
1453
1454 ap->blkno = NULLFSBLOCK;
1455 ap->length = 0;
1456 return 0;
1457 }
1458 if (error)
1459 return error;
1460
1461 xfs_trans_mod_sb(ap->tp, ap->wasdel ?
1462 XFS_TRANS_SB_RES_FREXTENTS : XFS_TRANS_SB_FREXTENTS,
1463 -(long)ralen);
1464 ap->blkno = xfs_rtx_to_rtb(mp, rtx);
1465 ap->length = xfs_rtxlen_to_extlen(mp, ralen);
1466 xfs_bmap_alloc_account(ap);
1467 return 0;
1468}
1469

source code of linux/fs/xfs/xfs_rtalloc.c