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1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_shared.h"
21#include "xfs_format.h"
22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
24#include "xfs_bit.h"
25#include "xfs_sb.h"
26#include "xfs_ag.h"
27#include "xfs_mount.h"
28#include "xfs_inode.h"
29#include "xfs_bmap.h"
30#include "xfs_bmap_util.h"
31#include "xfs_bmap_btree.h"
32#include "xfs_alloc.h"
33#include "xfs_error.h"
34#include "xfs_trans.h"
35#include "xfs_trans_space.h"
36#include "xfs_trace.h"
37#include "xfs_buf.h"
38#include "xfs_icache.h"
39#include "xfs_dinode.h"
40#include "xfs_rtalloc.h"
41
42
43/*
44 * Read and return the summary information for a given extent size,
45 * bitmap block combination.
46 * Keeps track of a current summary block, so we don't keep reading
47 * it from the buffer cache.
48 */
49STATIC int /* error */
50xfs_rtget_summary(
51 xfs_mount_t *mp, /* file system mount structure */
52 xfs_trans_t *tp, /* transaction pointer */
53 int log, /* log2 of extent size */
54 xfs_rtblock_t bbno, /* bitmap block number */
55 xfs_buf_t **rbpp, /* in/out: summary block buffer */
56 xfs_fsblock_t *rsb, /* in/out: summary block number */
57 xfs_suminfo_t *sum) /* out: summary info for this block */
58{
59 xfs_buf_t *bp; /* buffer for summary block */
60 int error; /* error value */
61 xfs_fsblock_t sb; /* summary fsblock */
62 int so; /* index into the summary file */
63 xfs_suminfo_t *sp; /* pointer to returned data */
64
65 /*
66 * Compute entry number in the summary file.
67 */
68 so = XFS_SUMOFFS(mp, log, bbno);
69 /*
70 * Compute the block number in the summary file.
71 */
72 sb = XFS_SUMOFFSTOBLOCK(mp, so);
73 /*
74 * If we have an old buffer, and the block number matches, use that.
75 */
76 if (rbpp && *rbpp && *rsb == sb)
77 bp = *rbpp;
78 /*
79 * Otherwise we have to get the buffer.
80 */
81 else {
82 /*
83 * If there was an old one, get rid of it first.
84 */
85 if (rbpp && *rbpp)
86 xfs_trans_brelse(tp, *rbpp);
87 error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
88 if (error) {
89 return error;
90 }
91 /*
92 * Remember this buffer and block for the next call.
93 */
94 if (rbpp) {
95 *rbpp = bp;
96 *rsb = sb;
97 }
98 }
99 /*
100 * Point to the summary information & copy it out.
101 */
102 sp = XFS_SUMPTR(mp, bp, so);
103 *sum = *sp;
104 /*
105 * Drop the buffer if we're not asked to remember it.
106 */
107 if (!rbpp)
108 xfs_trans_brelse(tp, bp);
109 return 0;
110}
111
112
113/*
114 * Return whether there are any free extents in the size range given
115 * by low and high, for the bitmap block bbno.
116 */
117STATIC int /* error */
118xfs_rtany_summary(
119 xfs_mount_t *mp, /* file system mount structure */
120 xfs_trans_t *tp, /* transaction pointer */
121 int low, /* low log2 extent size */
122 int high, /* high log2 extent size */
123 xfs_rtblock_t bbno, /* bitmap block number */
124 xfs_buf_t **rbpp, /* in/out: summary block buffer */
125 xfs_fsblock_t *rsb, /* in/out: summary block number */
126 int *stat) /* out: any good extents here? */
127{
128 int error; /* error value */
129 int log; /* loop counter, log2 of ext. size */
130 xfs_suminfo_t sum; /* summary data */
131
132 /*
133 * Loop over logs of extent sizes. Order is irrelevant.
134 */
135 for (log = low; log <= high; log++) {
136 /*
137 * Get one summary datum.
138 */
139 error = xfs_rtget_summary(mp, tp, log, bbno, rbpp, rsb, &sum);
140 if (error) {
141 return error;
142 }
143 /*
144 * If there are any, return success.
145 */
146 if (sum) {
147 *stat = 1;
148 return 0;
149 }
150 }
151 /*
152 * Found nothing, return failure.
153 */
154 *stat = 0;
155 return 0;
156}
157
158
159/*
160 * Copy and transform the summary file, given the old and new
161 * parameters in the mount structures.
162 */
163STATIC int /* error */
164xfs_rtcopy_summary(
165 xfs_mount_t *omp, /* old file system mount point */
166 xfs_mount_t *nmp, /* new file system mount point */
167 xfs_trans_t *tp) /* transaction pointer */
168{
169 xfs_rtblock_t bbno; /* bitmap block number */
170 xfs_buf_t *bp; /* summary buffer */
171 int error; /* error return value */
172 int log; /* summary level number (log length) */
173 xfs_suminfo_t sum; /* summary data */
174 xfs_fsblock_t sumbno; /* summary block number */
175
176 bp = NULL;
177 for (log = omp->m_rsumlevels - 1; log >= 0; log--) {
178 for (bbno = omp->m_sb.sb_rbmblocks - 1;
179 (xfs_srtblock_t)bbno >= 0;
180 bbno--) {
181 error = xfs_rtget_summary(omp, tp, log, bbno, &bp,
182 &sumbno, &sum);
183 if (error)
184 return error;
185 if (sum == 0)
186 continue;
187 error = xfs_rtmodify_summary(omp, tp, log, bbno, -sum,
188 &bp, &sumbno);
189 if (error)
190 return error;
191 error = xfs_rtmodify_summary(nmp, tp, log, bbno, sum,
192 &bp, &sumbno);
193 if (error)
194 return error;
195 ASSERT(sum > 0);
196 }
197 }
198 return 0;
199}
200/*
201 * Mark an extent specified by start and len allocated.
202 * Updates all the summary information as well as the bitmap.
203 */
204STATIC int /* error */
205xfs_rtallocate_range(
206 xfs_mount_t *mp, /* file system mount point */
207 xfs_trans_t *tp, /* transaction pointer */
208 xfs_rtblock_t start, /* start block to allocate */
209 xfs_extlen_t len, /* length to allocate */
210 xfs_buf_t **rbpp, /* in/out: summary block buffer */
211 xfs_fsblock_t *rsb) /* in/out: summary block number */
212{
213 xfs_rtblock_t end; /* end of the allocated extent */
214 int error; /* error value */
215 xfs_rtblock_t postblock = 0; /* first block allocated > end */
216 xfs_rtblock_t preblock = 0; /* first block allocated < start */
217
218 end = start + len - 1;
219 /*
220 * Assume we're allocating out of the middle of a free extent.
221 * We need to find the beginning and end of the extent so we can
222 * properly update the summary.
223 */
224 error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
225 if (error) {
226 return error;
227 }
228 /*
229 * Find the next allocated block (end of free extent).
230 */
231 error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
232 &postblock);
233 if (error) {
234 return error;
235 }
236 /*
237 * Decrement the summary information corresponding to the entire
238 * (old) free extent.
239 */
240 error = xfs_rtmodify_summary(mp, tp,
241 XFS_RTBLOCKLOG(postblock + 1 - preblock),
242 XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
243 if (error) {
244 return error;
245 }
246 /*
247 * If there are blocks not being allocated at the front of the
248 * old extent, add summary data for them to be free.
249 */
250 if (preblock < start) {
251 error = xfs_rtmodify_summary(mp, tp,
252 XFS_RTBLOCKLOG(start - preblock),
253 XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
254 if (error) {
255 return error;
256 }
257 }
258 /*
259 * If there are blocks not being allocated at the end of the
260 * old extent, add summary data for them to be free.
261 */
262 if (postblock > end) {
263 error = xfs_rtmodify_summary(mp, tp,
264 XFS_RTBLOCKLOG(postblock - end),
265 XFS_BITTOBLOCK(mp, end + 1), 1, rbpp, rsb);
266 if (error) {
267 return error;
268 }
269 }
270 /*
271 * Modify the bitmap to mark this extent allocated.
272 */
273 error = xfs_rtmodify_range(mp, tp, start, len, 0);
274 return error;
275}
276
277/*
278 * Attempt to allocate an extent minlen<=len<=maxlen starting from
279 * bitmap block bbno. If we don't get maxlen then use prod to trim
280 * the length, if given. Returns error; returns starting block in *rtblock.
281 * The lengths are all in rtextents.
282 */
283STATIC int /* error */
284xfs_rtallocate_extent_block(
285 xfs_mount_t *mp, /* file system mount point */
286 xfs_trans_t *tp, /* transaction pointer */
287 xfs_rtblock_t bbno, /* bitmap block number */
288 xfs_extlen_t minlen, /* minimum length to allocate */
289 xfs_extlen_t maxlen, /* maximum length to allocate */
290 xfs_extlen_t *len, /* out: actual length allocated */
291 xfs_rtblock_t *nextp, /* out: next block to try */
292 xfs_buf_t **rbpp, /* in/out: summary block buffer */
293 xfs_fsblock_t *rsb, /* in/out: summary block number */
294 xfs_extlen_t prod, /* extent product factor */
295 xfs_rtblock_t *rtblock) /* out: start block allocated */
296{
297 xfs_rtblock_t besti; /* best rtblock found so far */
298 xfs_rtblock_t bestlen; /* best length found so far */
299 xfs_rtblock_t end; /* last rtblock in chunk */
300 int error; /* error value */
301 xfs_rtblock_t i; /* current rtblock trying */
302 xfs_rtblock_t next; /* next rtblock to try */
303 int stat; /* status from internal calls */
304
305 /*
306 * Loop over all the extents starting in this bitmap block,
307 * looking for one that's long enough.
308 */
309 for (i = XFS_BLOCKTOBIT(mp, bbno), besti = -1, bestlen = 0,
310 end = XFS_BLOCKTOBIT(mp, bbno + 1) - 1;
311 i <= end;
312 i++) {
313 /*
314 * See if there's a free extent of maxlen starting at i.
315 * If it's not so then next will contain the first non-free.
316 */
317 error = xfs_rtcheck_range(mp, tp, i, maxlen, 1, &next, &stat);
318 if (error) {
319 return error;
320 }
321 if (stat) {
322 /*
323 * i for maxlen is all free, allocate and return that.
324 */
325 error = xfs_rtallocate_range(mp, tp, i, maxlen, rbpp,
326 rsb);
327 if (error) {
328 return error;
329 }
330 *len = maxlen;
331 *rtblock = i;
332 return 0;
333 }
334 /*
335 * In the case where we have a variable-sized allocation
336 * request, figure out how big this free piece is,
337 * and if it's big enough for the minimum, and the best
338 * so far, remember it.
339 */
340 if (minlen < maxlen) {
341 xfs_rtblock_t thislen; /* this extent size */
342
343 thislen = next - i;
344 if (thislen >= minlen && thislen > bestlen) {
345 besti = i;
346 bestlen = thislen;
347 }
348 }
349 /*
350 * If not done yet, find the start of the next free space.
351 */
352 if (next < end) {
353 error = xfs_rtfind_forw(mp, tp, next, end, &i);
354 if (error) {
355 return error;
356 }
357 } else
358 break;
359 }
360 /*
361 * Searched the whole thing & didn't find a maxlen free extent.
362 */
363 if (minlen < maxlen && besti != -1) {
364 xfs_extlen_t p; /* amount to trim length by */
365
366 /*
367 * If size should be a multiple of prod, make that so.
368 */
369 if (prod > 1 && (p = do_mod(bestlen, prod)))
370 bestlen -= p;
371 /*
372 * Allocate besti for bestlen & return that.
373 */
374 error = xfs_rtallocate_range(mp, tp, besti, bestlen, rbpp, rsb);
375 if (error) {
376 return error;
377 }
378 *len = bestlen;
379 *rtblock = besti;
380 return 0;
381 }
382 /*
383 * Allocation failed. Set *nextp to the next block to try.
384 */
385 *nextp = next;
386 *rtblock = NULLRTBLOCK;
387 return 0;
388}
389
390/*
391 * Allocate an extent of length minlen<=len<=maxlen, starting at block
392 * bno. If we don't get maxlen then use prod to trim the length, if given.
393 * Returns error; returns starting block in *rtblock.
394 * The lengths are all in rtextents.
395 */
396STATIC int /* error */
397xfs_rtallocate_extent_exact(
398 xfs_mount_t *mp, /* file system mount point */
399 xfs_trans_t *tp, /* transaction pointer */
400 xfs_rtblock_t bno, /* starting block number to allocate */
401 xfs_extlen_t minlen, /* minimum length to allocate */
402 xfs_extlen_t maxlen, /* maximum length to allocate */
403 xfs_extlen_t *len, /* out: actual length allocated */
404 xfs_buf_t **rbpp, /* in/out: summary block buffer */
405 xfs_fsblock_t *rsb, /* in/out: summary block number */
406 xfs_extlen_t prod, /* extent product factor */
407 xfs_rtblock_t *rtblock) /* out: start block allocated */
408{
409 int error; /* error value */
410 xfs_extlen_t i; /* extent length trimmed due to prod */
411 int isfree; /* extent is free */
412 xfs_rtblock_t next; /* next block to try (dummy) */
413
414 ASSERT(minlen % prod == 0 && maxlen % prod == 0);
415 /*
416 * Check if the range in question (for maxlen) is free.
417 */
418 error = xfs_rtcheck_range(mp, tp, bno, maxlen, 1, &next, &isfree);
419 if (error) {
420 return error;
421 }
422 if (isfree) {
423 /*
424 * If it is, allocate it and return success.
425 */
426 error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
427 if (error) {
428 return error;
429 }
430 *len = maxlen;
431 *rtblock = bno;
432 return 0;
433 }
434 /*
435 * If not, allocate what there is, if it's at least minlen.
436 */
437 maxlen = next - bno;
438 if (maxlen < minlen) {
439 /*
440 * Failed, return failure status.
441 */
442 *rtblock = NULLRTBLOCK;
443 return 0;
444 }
445 /*
446 * Trim off tail of extent, if prod is specified.
447 */
448 if (prod > 1 && (i = maxlen % prod)) {
449 maxlen -= i;
450 if (maxlen < minlen) {
451 /*
452 * Now we can't do it, return failure status.
453 */
454 *rtblock = NULLRTBLOCK;
455 return 0;
456 }
457 }
458 /*
459 * Allocate what we can and return it.
460 */
461 error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
462 if (error) {
463 return error;
464 }
465 *len = maxlen;
466 *rtblock = bno;
467 return 0;
468}
469
470/*
471 * Allocate an extent of length minlen<=len<=maxlen, starting as near
472 * to bno as possible. If we don't get maxlen then use prod to trim
473 * the length, if given. The lengths are all in rtextents.
474 */
475STATIC int /* error */
476xfs_rtallocate_extent_near(
477 xfs_mount_t *mp, /* file system mount point */
478 xfs_trans_t *tp, /* transaction pointer */
479 xfs_rtblock_t bno, /* starting block number to allocate */
480 xfs_extlen_t minlen, /* minimum length to allocate */
481 xfs_extlen_t maxlen, /* maximum length to allocate */
482 xfs_extlen_t *len, /* out: actual length allocated */
483 xfs_buf_t **rbpp, /* in/out: summary block buffer */
484 xfs_fsblock_t *rsb, /* in/out: summary block number */
485 xfs_extlen_t prod, /* extent product factor */
486 xfs_rtblock_t *rtblock) /* out: start block allocated */
487{
488 int any; /* any useful extents from summary */
489 xfs_rtblock_t bbno; /* bitmap block number */
490 int error; /* error value */
491 int i; /* bitmap block offset (loop control) */
492 int j; /* secondary loop control */
493 int log2len; /* log2 of minlen */
494 xfs_rtblock_t n; /* next block to try */
495 xfs_rtblock_t r; /* result block */
496
497 ASSERT(minlen % prod == 0 && maxlen % prod == 0);
498 /*
499 * If the block number given is off the end, silently set it to
500 * the last block.
501 */
502 if (bno >= mp->m_sb.sb_rextents)
503 bno = mp->m_sb.sb_rextents - 1;
504 /*
505 * Try the exact allocation first.
506 */
507 error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, len,
508 rbpp, rsb, prod, &r);
509 if (error) {
510 return error;
511 }
512 /*
513 * If the exact allocation worked, return that.
514 */
515 if (r != NULLRTBLOCK) {
516 *rtblock = r;
517 return 0;
518 }
519 bbno = XFS_BITTOBLOCK(mp, bno);
520 i = 0;
521 ASSERT(minlen != 0);
522 log2len = xfs_highbit32(minlen);
523 /*
524 * Loop over all bitmap blocks (bbno + i is current block).
525 */
526 for (;;) {
527 /*
528 * Get summary information of extents of all useful levels
529 * starting in this bitmap block.
530 */
531 error = xfs_rtany_summary(mp, tp, log2len, mp->m_rsumlevels - 1,
532 bbno + i, rbpp, rsb, &any);
533 if (error) {
534 return error;
535 }
536 /*
537 * If there are any useful extents starting here, try
538 * allocating one.
539 */
540 if (any) {
541 /*
542 * On the positive side of the starting location.
543 */
544 if (i >= 0) {
545 /*
546 * Try to allocate an extent starting in
547 * this block.
548 */
549 error = xfs_rtallocate_extent_block(mp, tp,
550 bbno + i, minlen, maxlen, len, &n, rbpp,
551 rsb, prod, &r);
552 if (error) {
553 return error;
554 }
555 /*
556 * If it worked, return it.
557 */
558 if (r != NULLRTBLOCK) {
559 *rtblock = r;
560 return 0;
561 }
562 }
563 /*
564 * On the negative side of the starting location.
565 */
566 else { /* i < 0 */
567 /*
568 * Loop backwards through the bitmap blocks from
569 * the starting point-1 up to where we are now.
570 * There should be an extent which ends in this
571 * bitmap block and is long enough.
572 */
573 for (j = -1; j > i; j--) {
574 /*
575 * Grab the summary information for
576 * this bitmap block.
577 */
578 error = xfs_rtany_summary(mp, tp,
579 log2len, mp->m_rsumlevels - 1,
580 bbno + j, rbpp, rsb, &any);
581 if (error) {
582 return error;
583 }
584 /*
585 * If there's no extent given in the
586 * summary that means the extent we
587 * found must carry over from an
588 * earlier block. If there is an
589 * extent given, we've already tried
590 * that allocation, don't do it again.
591 */
592 if (any)
593 continue;
594 error = xfs_rtallocate_extent_block(mp,
595 tp, bbno + j, minlen, maxlen,
596 len, &n, rbpp, rsb, prod, &r);
597 if (error) {
598 return error;
599 }
600 /*
601 * If it works, return the extent.
602 */
603 if (r != NULLRTBLOCK) {
604 *rtblock = r;
605 return 0;
606 }
607 }
608 /*
609 * There weren't intervening bitmap blocks
610 * with a long enough extent, or the
611 * allocation didn't work for some reason
612 * (i.e. it's a little * too short).
613 * Try to allocate from the summary block
614 * that we found.
615 */
616 error = xfs_rtallocate_extent_block(mp, tp,
617 bbno + i, minlen, maxlen, len, &n, rbpp,
618 rsb, prod, &r);
619 if (error) {
620 return error;
621 }
622 /*
623 * If it works, return the extent.
624 */
625 if (r != NULLRTBLOCK) {
626 *rtblock = r;
627 return 0;
628 }
629 }
630 }
631 /*
632 * Loop control. If we were on the positive side, and there's
633 * still more blocks on the negative side, go there.
634 */
635 if (i > 0 && (int)bbno - i >= 0)
636 i = -i;
637 /*
638 * If positive, and no more negative, but there are more
639 * positive, go there.
640 */
641 else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
642 i++;
643 /*
644 * If negative or 0 (just started), and there are positive
645 * blocks to go, go there. The 0 case moves to block 1.
646 */
647 else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
648 i = 1 - i;
649 /*
650 * If negative or 0 and there are more negative blocks,
651 * go there.
652 */
653 else if (i <= 0 && (int)bbno + i > 0)
654 i--;
655 /*
656 * Must be done. Return failure.
657 */
658 else
659 break;
660 }
661 *rtblock = NULLRTBLOCK;
662 return 0;
663}
664
665/*
666 * Allocate an extent of length minlen<=len<=maxlen, with no position
667 * specified. If we don't get maxlen then use prod to trim
668 * the length, if given. The lengths are all in rtextents.
669 */
670STATIC int /* error */
671xfs_rtallocate_extent_size(
672 xfs_mount_t *mp, /* file system mount point */
673 xfs_trans_t *tp, /* transaction pointer */
674 xfs_extlen_t minlen, /* minimum length to allocate */
675 xfs_extlen_t maxlen, /* maximum length to allocate */
676 xfs_extlen_t *len, /* out: actual length allocated */
677 xfs_buf_t **rbpp, /* in/out: summary block buffer */
678 xfs_fsblock_t *rsb, /* in/out: summary block number */
679 xfs_extlen_t prod, /* extent product factor */
680 xfs_rtblock_t *rtblock) /* out: start block allocated */
681{
682 int error; /* error value */
683 int i; /* bitmap block number */
684 int l; /* level number (loop control) */
685 xfs_rtblock_t n; /* next block to be tried */
686 xfs_rtblock_t r; /* result block number */
687 xfs_suminfo_t sum; /* summary information for extents */
688
689 ASSERT(minlen % prod == 0 && maxlen % prod == 0);
690 ASSERT(maxlen != 0);
691
692 /*
693 * Loop over all the levels starting with maxlen.
694 * At each level, look at all the bitmap blocks, to see if there
695 * are extents starting there that are long enough (>= maxlen).
696 * Note, only on the initial level can the allocation fail if
697 * the summary says there's an extent.
698 */
699 for (l = xfs_highbit32(maxlen); l < mp->m_rsumlevels; l++) {
700 /*
701 * Loop over all the bitmap blocks.
702 */
703 for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
704 /*
705 * Get the summary for this level/block.
706 */
707 error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
708 &sum);
709 if (error) {
710 return error;
711 }
712 /*
713 * Nothing there, on to the next block.
714 */
715 if (!sum)
716 continue;
717 /*
718 * Try allocating the extent.
719 */
720 error = xfs_rtallocate_extent_block(mp, tp, i, maxlen,
721 maxlen, len, &n, rbpp, rsb, prod, &r);
722 if (error) {
723 return error;
724 }
725 /*
726 * If it worked, return that.
727 */
728 if (r != NULLRTBLOCK) {
729 *rtblock = r;
730 return 0;
731 }
732 /*
733 * If the "next block to try" returned from the
734 * allocator is beyond the next bitmap block,
735 * skip to that bitmap block.
736 */
737 if (XFS_BITTOBLOCK(mp, n) > i + 1)
738 i = XFS_BITTOBLOCK(mp, n) - 1;
739 }
740 }
741 /*
742 * Didn't find any maxlen blocks. Try smaller ones, unless
743 * we're asking for a fixed size extent.
744 */
745 if (minlen > --maxlen) {
746 *rtblock = NULLRTBLOCK;
747 return 0;
748 }
749 ASSERT(minlen != 0);
750 ASSERT(maxlen != 0);
751
752 /*
753 * Loop over sizes, from maxlen down to minlen.
754 * This time, when we do the allocations, allow smaller ones
755 * to succeed.
756 */
757 for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
758 /*
759 * Loop over all the bitmap blocks, try an allocation
760 * starting in that block.
761 */
762 for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
763 /*
764 * Get the summary information for this level/block.
765 */
766 error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
767 &sum);
768 if (error) {
769 return error;
770 }
771 /*
772 * If nothing there, go on to next.
773 */
774 if (!sum)
775 continue;
776 /*
777 * Try the allocation. Make sure the specified
778 * minlen/maxlen are in the possible range for
779 * this summary level.
780 */
781 error = xfs_rtallocate_extent_block(mp, tp, i,
782 XFS_RTMAX(minlen, 1 << l),
783 XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
784 len, &n, rbpp, rsb, prod, &r);
785 if (error) {
786 return error;
787 }
788 /*
789 * If it worked, return that extent.
790 */
791 if (r != NULLRTBLOCK) {
792 *rtblock = r;
793 return 0;
794 }
795 /*
796 * If the "next block to try" returned from the
797 * allocator is beyond the next bitmap block,
798 * skip to that bitmap block.
799 */
800 if (XFS_BITTOBLOCK(mp, n) > i + 1)
801 i = XFS_BITTOBLOCK(mp, n) - 1;
802 }
803 }
804 /*
805 * Got nothing, return failure.
806 */
807 *rtblock = NULLRTBLOCK;
808 return 0;
809}
810
811/*
812 * Allocate space to the bitmap or summary file, and zero it, for growfs.
813 */
814STATIC int /* error */
815xfs_growfs_rt_alloc(
816 xfs_mount_t *mp, /* file system mount point */
817 xfs_extlen_t oblocks, /* old count of blocks */
818 xfs_extlen_t nblocks, /* new count of blocks */
819 xfs_inode_t *ip) /* inode (bitmap/summary) */
820{
821 xfs_fileoff_t bno; /* block number in file */
822 xfs_buf_t *bp; /* temporary buffer for zeroing */
823 int committed; /* transaction committed flag */
824 xfs_daddr_t d; /* disk block address */
825 int error; /* error return value */
826 xfs_fsblock_t firstblock; /* first block allocated in xaction */
827 xfs_bmap_free_t flist; /* list of freed blocks */
828 xfs_fsblock_t fsbno; /* filesystem block for bno */
829 xfs_bmbt_irec_t map; /* block map output */
830 int nmap; /* number of block maps */
831 int resblks; /* space reservation */
832
833 /*
834 * Allocate space to the file, as necessary.
835 */
836 while (oblocks < nblocks) {
837 int cancelflags = 0;
838 xfs_trans_t *tp;
839
840 tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_ALLOC);
841 resblks = XFS_GROWFSRT_SPACE_RES(mp, nblocks - oblocks);
842 /*
843 * Reserve space & log for one extent added to the file.
844 */
845 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_growrtalloc,
846 resblks, 0);
847 if (error)
848 goto error_cancel;
849 cancelflags = XFS_TRANS_RELEASE_LOG_RES;
850 /*
851 * Lock the inode.
852 */
853 xfs_ilock(ip, XFS_ILOCK_EXCL);
854 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
855
856 xfs_bmap_init(&flist, &firstblock);
857 /*
858 * Allocate blocks to the bitmap file.
859 */
860 nmap = 1;
861 cancelflags |= XFS_TRANS_ABORT;
862 error = xfs_bmapi_write(tp, ip, oblocks, nblocks - oblocks,
863 XFS_BMAPI_METADATA, &firstblock,
864 resblks, &map, &nmap, &flist);
865 if (!error && nmap < 1)
866 error = XFS_ERROR(ENOSPC);
867 if (error)
868 goto error_cancel;
869 /*
870 * Free any blocks freed up in the transaction, then commit.
871 */
872 error = xfs_bmap_finish(&tp, &flist, &committed);
873 if (error)
874 goto error_cancel;
875 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
876 if (error)
877 goto error;
878 /*
879 * Now we need to clear the allocated blocks.
880 * Do this one block per transaction, to keep it simple.
881 */
882 cancelflags = 0;
883 for (bno = map.br_startoff, fsbno = map.br_startblock;
884 bno < map.br_startoff + map.br_blockcount;
885 bno++, fsbno++) {
886 tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_ZERO);
887 /*
888 * Reserve log for one block zeroing.
889 */
890 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_growrtzero,
891 0, 0);
892 if (error)
893 goto error_cancel;
894 /*
895 * Lock the bitmap inode.
896 */
897 xfs_ilock(ip, XFS_ILOCK_EXCL);
898 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
899 /*
900 * Get a buffer for the block.
901 */
902 d = XFS_FSB_TO_DADDR(mp, fsbno);
903 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
904 mp->m_bsize, 0);
905 if (bp == NULL) {
906 error = XFS_ERROR(EIO);
907error_cancel:
908 xfs_trans_cancel(tp, cancelflags);
909 goto error;
910 }
911 memset(bp->b_addr, 0, mp->m_sb.sb_blocksize);
912 xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
913 /*
914 * Commit the transaction.
915 */
916 error = xfs_trans_commit(tp, 0);
917 if (error)
918 goto error;
919 }
920 /*
921 * Go on to the next extent, if any.
922 */
923 oblocks = map.br_startoff + map.br_blockcount;
924 }
925 return 0;
926
927error:
928 return error;
929}
930
931/*
932 * Visible (exported) functions.
933 */
934
935/*
936 * Grow the realtime area of the filesystem.
937 */
938int
939xfs_growfs_rt(
940 xfs_mount_t *mp, /* mount point for filesystem */
941 xfs_growfs_rt_t *in) /* growfs rt input struct */
942{
943 xfs_rtblock_t bmbno; /* bitmap block number */
944 xfs_buf_t *bp; /* temporary buffer */
945 int error; /* error return value */
946 xfs_mount_t *nmp; /* new (fake) mount structure */
947 xfs_drfsbno_t nrblocks; /* new number of realtime blocks */
948 xfs_extlen_t nrbmblocks; /* new number of rt bitmap blocks */
949 xfs_drtbno_t nrextents; /* new number of realtime extents */
950 uint8_t nrextslog; /* new log2 of sb_rextents */
951 xfs_extlen_t nrsumblocks; /* new number of summary blocks */
952 uint nrsumlevels; /* new rt summary levels */
953 uint nrsumsize; /* new size of rt summary, bytes */
954 xfs_sb_t *nsbp; /* new superblock */
955 xfs_extlen_t rbmblocks; /* current number of rt bitmap blocks */
956 xfs_extlen_t rsumblocks; /* current number of rt summary blks */
957 xfs_sb_t *sbp; /* old superblock */
958 xfs_fsblock_t sumbno; /* summary block number */
959
960 sbp = &mp->m_sb;
961 /*
962 * Initial error checking.
963 */
964 if (!capable(CAP_SYS_ADMIN))
965 return XFS_ERROR(EPERM);
966 if (mp->m_rtdev_targp == NULL || mp->m_rbmip == NULL ||
967 (nrblocks = in->newblocks) <= sbp->sb_rblocks ||
968 (sbp->sb_rblocks && (in->extsize != sbp->sb_rextsize)))
969 return XFS_ERROR(EINVAL);
970 if ((error = xfs_sb_validate_fsb_count(sbp, nrblocks)))
971 return error;
972 /*
973 * Read in the last block of the device, make sure it exists.
974 */
975 bp = xfs_buf_read_uncached(mp->m_rtdev_targp,
976 XFS_FSB_TO_BB(mp, nrblocks - 1),
977 XFS_FSB_TO_BB(mp, 1), 0, NULL);
978 if (!bp)
979 return EIO;
980 if (bp->b_error) {
981 error = bp->b_error;
982 xfs_buf_relse(bp);
983 return error;
984 }
985 xfs_buf_relse(bp);
986
987 /*
988 * Calculate new parameters. These are the final values to be reached.
989 */
990 nrextents = nrblocks;
991 do_div(nrextents, in->extsize);
992 nrbmblocks = howmany_64(nrextents, NBBY * sbp->sb_blocksize);
993 nrextslog = xfs_highbit32(nrextents);
994 nrsumlevels = nrextslog + 1;
995 nrsumsize = (uint)sizeof(xfs_suminfo_t) * nrsumlevels * nrbmblocks;
996 nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
997 nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
998 /*
999 * New summary size can't be more than half the size of
1000 * the log. This prevents us from getting a log overflow,
1001 * since we'll log basically the whole summary file at once.
1002 */
1003 if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1))
1004 return XFS_ERROR(EINVAL);
1005 /*
1006 * Get the old block counts for bitmap and summary inodes.
1007 * These can't change since other growfs callers are locked out.
1008 */
1009 rbmblocks = XFS_B_TO_FSB(mp, mp->m_rbmip->i_d.di_size);
1010 rsumblocks = XFS_B_TO_FSB(mp, mp->m_rsumip->i_d.di_size);
1011 /*
1012 * Allocate space to the bitmap and summary files, as necessary.
1013 */
1014 error = xfs_growfs_rt_alloc(mp, rbmblocks, nrbmblocks, mp->m_rbmip);
1015 if (error)
1016 return error;
1017 error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip);
1018 if (error)
1019 return error;
1020 /*
1021 * Allocate a new (fake) mount/sb.
1022 */
1023 nmp = kmem_alloc(sizeof(*nmp), KM_SLEEP);
1024 /*
1025 * Loop over the bitmap blocks.
1026 * We will do everything one bitmap block at a time.
1027 * Skip the current block if it is exactly full.
1028 * This also deals with the case where there were no rtextents before.
1029 */
1030 for (bmbno = sbp->sb_rbmblocks -
1031 ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
1032 bmbno < nrbmblocks;
1033 bmbno++) {
1034 xfs_trans_t *tp;
1035 int cancelflags = 0;
1036
1037 *nmp = *mp;
1038 nsbp = &nmp->m_sb;
1039 /*
1040 * Calculate new sb and mount fields for this round.
1041 */
1042 nsbp->sb_rextsize = in->extsize;
1043 nsbp->sb_rbmblocks = bmbno + 1;
1044 nsbp->sb_rblocks =
1045 XFS_RTMIN(nrblocks,
1046 nsbp->sb_rbmblocks * NBBY *
1047 nsbp->sb_blocksize * nsbp->sb_rextsize);
1048 nsbp->sb_rextents = nsbp->sb_rblocks;
1049 do_div(nsbp->sb_rextents, nsbp->sb_rextsize);
1050 ASSERT(nsbp->sb_rextents != 0);
1051 nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents);
1052 nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
1053 nrsumsize =
1054 (uint)sizeof(xfs_suminfo_t) * nrsumlevels *
1055 nsbp->sb_rbmblocks;
1056 nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
1057 nmp->m_rsumsize = nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
1058 /*
1059 * Start a transaction, get the log reservation.
1060 */
1061 tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_FREE);
1062 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_growrtfree,
1063 0, 0);
1064 if (error)
1065 goto error_cancel;
1066 /*
1067 * Lock out other callers by grabbing the bitmap inode lock.
1068 */
1069 xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
1070 xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
1071 /*
1072 * Update the bitmap inode's size.
1073 */
1074 mp->m_rbmip->i_d.di_size =
1075 nsbp->sb_rbmblocks * nsbp->sb_blocksize;
1076 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1077 cancelflags |= XFS_TRANS_ABORT;
1078 /*
1079 * Get the summary inode into the transaction.
1080 */
1081 xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL);
1082 xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
1083 /*
1084 * Update the summary inode's size.
1085 */
1086 mp->m_rsumip->i_d.di_size = nmp->m_rsumsize;
1087 xfs_trans_log_inode(tp, mp->m_rsumip, XFS_ILOG_CORE);
1088 /*
1089 * Copy summary data from old to new sizes.
1090 * Do this when the real size (not block-aligned) changes.
1091 */
1092 if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
1093 mp->m_rsumlevels != nmp->m_rsumlevels) {
1094 error = xfs_rtcopy_summary(mp, nmp, tp);
1095 if (error)
1096 goto error_cancel;
1097 }
1098 /*
1099 * Update superblock fields.
1100 */
1101 if (nsbp->sb_rextsize != sbp->sb_rextsize)
1102 xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
1103 nsbp->sb_rextsize - sbp->sb_rextsize);
1104 if (nsbp->sb_rbmblocks != sbp->sb_rbmblocks)
1105 xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
1106 nsbp->sb_rbmblocks - sbp->sb_rbmblocks);
1107 if (nsbp->sb_rblocks != sbp->sb_rblocks)
1108 xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
1109 nsbp->sb_rblocks - sbp->sb_rblocks);
1110 if (nsbp->sb_rextents != sbp->sb_rextents)
1111 xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
1112 nsbp->sb_rextents - sbp->sb_rextents);
1113 if (nsbp->sb_rextslog != sbp->sb_rextslog)
1114 xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
1115 nsbp->sb_rextslog - sbp->sb_rextslog);
1116 /*
1117 * Free new extent.
1118 */
1119 bp = NULL;
1120 error = xfs_rtfree_range(nmp, tp, sbp->sb_rextents,
1121 nsbp->sb_rextents - sbp->sb_rextents, &bp, &sumbno);
1122 if (error) {
1123error_cancel:
1124 xfs_trans_cancel(tp, cancelflags);
1125 break;
1126 }
1127 /*
1128 * Mark more blocks free in the superblock.
1129 */
1130 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS,
1131 nsbp->sb_rextents - sbp->sb_rextents);
1132 /*
1133 * Update mp values into the real mp structure.
1134 */
1135 mp->m_rsumlevels = nrsumlevels;
1136 mp->m_rsumsize = nrsumsize;
1137
1138 error = xfs_trans_commit(tp, 0);
1139 if (error)
1140 break;
1141 }
1142
1143 /*
1144 * Free the fake mp structure.
1145 */
1146 kmem_free(nmp);
1147
1148 return error;
1149}
1150
1151/*
1152 * Allocate an extent in the realtime subvolume, with the usual allocation
1153 * parameters. The length units are all in realtime extents, as is the
1154 * result block number.
1155 */
1156int /* error */
1157xfs_rtallocate_extent(
1158 xfs_trans_t *tp, /* transaction pointer */
1159 xfs_rtblock_t bno, /* starting block number to allocate */
1160 xfs_extlen_t minlen, /* minimum length to allocate */
1161 xfs_extlen_t maxlen, /* maximum length to allocate */
1162 xfs_extlen_t *len, /* out: actual length allocated */
1163 xfs_alloctype_t type, /* allocation type XFS_ALLOCTYPE... */
1164 int wasdel, /* was a delayed allocation extent */
1165 xfs_extlen_t prod, /* extent product factor */
1166 xfs_rtblock_t *rtblock) /* out: start block allocated */
1167{
1168 xfs_mount_t *mp = tp->t_mountp;
1169 int error; /* error value */
1170 xfs_rtblock_t r; /* result allocated block */
1171 xfs_fsblock_t sb; /* summary file block number */
1172 xfs_buf_t *sumbp; /* summary file block buffer */
1173
1174 ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
1175 ASSERT(minlen > 0 && minlen <= maxlen);
1176
1177 /*
1178 * If prod is set then figure out what to do to minlen and maxlen.
1179 */
1180 if (prod > 1) {
1181 xfs_extlen_t i;
1182
1183 if ((i = maxlen % prod))
1184 maxlen -= i;
1185 if ((i = minlen % prod))
1186 minlen += prod - i;
1187 if (maxlen < minlen) {
1188 *rtblock = NULLRTBLOCK;
1189 return 0;
1190 }
1191 }
1192
1193 sumbp = NULL;
1194 /*
1195 * Allocate by size, or near another block, or exactly at some block.
1196 */
1197 switch (type) {
1198 case XFS_ALLOCTYPE_ANY_AG:
1199 error = xfs_rtallocate_extent_size(mp, tp, minlen, maxlen, len,
1200 &sumbp, &sb, prod, &r);
1201 break;
1202 case XFS_ALLOCTYPE_NEAR_BNO:
1203 error = xfs_rtallocate_extent_near(mp, tp, bno, minlen, maxlen,
1204 len, &sumbp, &sb, prod, &r);
1205 break;
1206 case XFS_ALLOCTYPE_THIS_BNO:
1207 error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen,
1208 len, &sumbp, &sb, prod, &r);
1209 break;
1210 default:
1211 error = EIO;
1212 ASSERT(0);
1213 }
1214 if (error)
1215 return error;
1216
1217 /*
1218 * If it worked, update the superblock.
1219 */
1220 if (r != NULLRTBLOCK) {
1221 long slen = (long)*len;
1222
1223 ASSERT(*len >= minlen && *len <= maxlen);
1224 if (wasdel)
1225 xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FREXTENTS, -slen);
1226 else
1227 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, -slen);
1228 }
1229 *rtblock = r;
1230 return 0;
1231}
1232
1233/*
1234 * Initialize realtime fields in the mount structure.
1235 */
1236int /* error */
1237xfs_rtmount_init(
1238 xfs_mount_t *mp) /* file system mount structure */
1239{
1240 xfs_buf_t *bp; /* buffer for last block of subvolume */
1241 xfs_daddr_t d; /* address of last block of subvolume */
1242 xfs_sb_t *sbp; /* filesystem superblock copy in mount */
1243
1244 sbp = &mp->m_sb;
1245 if (sbp->sb_rblocks == 0)
1246 return 0;
1247 if (mp->m_rtdev_targp == NULL) {
1248 xfs_warn(mp,
1249 "Filesystem has a realtime volume, use rtdev=device option");
1250 return XFS_ERROR(ENODEV);
1251 }
1252 mp->m_rsumlevels = sbp->sb_rextslog + 1;
1253 mp->m_rsumsize =
1254 (uint)sizeof(xfs_suminfo_t) * mp->m_rsumlevels *
1255 sbp->sb_rbmblocks;
1256 mp->m_rsumsize = roundup(mp->m_rsumsize, sbp->sb_blocksize);
1257 mp->m_rbmip = mp->m_rsumip = NULL;
1258 /*
1259 * Check that the realtime section is an ok size.
1260 */
1261 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
1262 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_rblocks) {
1263 xfs_warn(mp, "realtime mount -- %llu != %llu",
1264 (unsigned long long) XFS_BB_TO_FSB(mp, d),
1265 (unsigned long long) mp->m_sb.sb_rblocks);
1266 return XFS_ERROR(EFBIG);
1267 }
1268 bp = xfs_buf_read_uncached(mp->m_rtdev_targp,
1269 d - XFS_FSB_TO_BB(mp, 1),
1270 XFS_FSB_TO_BB(mp, 1), 0, NULL);
1271 if (!bp || bp->b_error) {
1272 xfs_warn(mp, "realtime device size check failed");
1273 if (bp)
1274 xfs_buf_relse(bp);
1275 return EIO;
1276 }
1277 xfs_buf_relse(bp);
1278 return 0;
1279}
1280
1281/*
1282 * Get the bitmap and summary inodes into the mount structure
1283 * at mount time.
1284 */
1285int /* error */
1286xfs_rtmount_inodes(
1287 xfs_mount_t *mp) /* file system mount structure */
1288{
1289 int error; /* error return value */
1290 xfs_sb_t *sbp;
1291
1292 sbp = &mp->m_sb;
1293 if (sbp->sb_rbmino == NULLFSINO)
1294 return 0;
1295 error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip);
1296 if (error)
1297 return error;
1298 ASSERT(mp->m_rbmip != NULL);
1299 ASSERT(sbp->sb_rsumino != NULLFSINO);
1300 error = xfs_iget(mp, NULL, sbp->sb_rsumino, 0, 0, &mp->m_rsumip);
1301 if (error) {
1302 IRELE(mp->m_rbmip);
1303 return error;
1304 }
1305 ASSERT(mp->m_rsumip != NULL);
1306 return 0;
1307}
1308
1309void
1310xfs_rtunmount_inodes(
1311 struct xfs_mount *mp)
1312{
1313 if (mp->m_rbmip)
1314 IRELE(mp->m_rbmip);
1315 if (mp->m_rsumip)
1316 IRELE(mp->m_rsumip);
1317}
1318
1319/*
1320 * Pick an extent for allocation at the start of a new realtime file.
1321 * Use the sequence number stored in the atime field of the bitmap inode.
1322 * Translate this to a fraction of the rtextents, and return the product
1323 * of rtextents and the fraction.
1324 * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
1325 */
1326int /* error */
1327xfs_rtpick_extent(
1328 xfs_mount_t *mp, /* file system mount point */
1329 xfs_trans_t *tp, /* transaction pointer */
1330 xfs_extlen_t len, /* allocation length (rtextents) */
1331 xfs_rtblock_t *pick) /* result rt extent */
1332{
1333 xfs_rtblock_t b; /* result block */
1334 int log2; /* log of sequence number */
1335 __uint64_t resid; /* residual after log removed */
1336 __uint64_t seq; /* sequence number of file creation */
1337 __uint64_t *seqp; /* pointer to seqno in inode */
1338
1339 ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
1340
1341 seqp = (__uint64_t *)&mp->m_rbmip->i_d.di_atime;
1342 if (!(mp->m_rbmip->i_d.di_flags & XFS_DIFLAG_NEWRTBM)) {
1343 mp->m_rbmip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
1344 *seqp = 0;
1345 }
1346 seq = *seqp;
1347 if ((log2 = xfs_highbit64(seq)) == -1)
1348 b = 0;
1349 else {
1350 resid = seq - (1ULL << log2);
1351 b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >>
1352 (log2 + 1);
1353 if (b >= mp->m_sb.sb_rextents)
1354 b = do_mod(b, mp->m_sb.sb_rextents);
1355 if (b + len > mp->m_sb.sb_rextents)
1356 b = mp->m_sb.sb_rextents - len;
1357 }
1358 *seqp = seq + 1;
1359 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1360 *pick = b;
1361 return 0;
1362}
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_trans.h"
18#include "xfs_trans_space.h"
19#include "xfs_icache.h"
20#include "xfs_rtalloc.h"
21#include "xfs_sb.h"
22
23/*
24 * Read and return the summary information for a given extent size,
25 * bitmap block combination.
26 * Keeps track of a current summary block, so we don't keep reading
27 * it from the buffer cache.
28 */
29static int
30xfs_rtget_summary(
31 xfs_mount_t *mp, /* file system mount structure */
32 xfs_trans_t *tp, /* transaction pointer */
33 int log, /* log2 of extent size */
34 xfs_rtblock_t bbno, /* bitmap block number */
35 struct xfs_buf **rbpp, /* in/out: summary block buffer */
36 xfs_fsblock_t *rsb, /* in/out: summary block number */
37 xfs_suminfo_t *sum) /* out: summary info for this block */
38{
39 return xfs_rtmodify_summary_int(mp, tp, log, bbno, 0, rbpp, rsb, sum);
40}
41
42/*
43 * Return whether there are any free extents in the size range given
44 * by low and high, for the bitmap block bbno.
45 */
46STATIC int /* error */
47xfs_rtany_summary(
48 xfs_mount_t *mp, /* file system mount structure */
49 xfs_trans_t *tp, /* transaction pointer */
50 int low, /* low log2 extent size */
51 int high, /* high log2 extent size */
52 xfs_rtblock_t bbno, /* bitmap block number */
53 struct xfs_buf **rbpp, /* in/out: summary block buffer */
54 xfs_fsblock_t *rsb, /* in/out: summary block number */
55 int *stat) /* out: any good extents here? */
56{
57 int error; /* error value */
58 int log; /* loop counter, log2 of ext. size */
59 xfs_suminfo_t sum; /* summary data */
60
61 /* There are no extents at levels < m_rsum_cache[bbno]. */
62 if (mp->m_rsum_cache && low < mp->m_rsum_cache[bbno])
63 low = mp->m_rsum_cache[bbno];
64
65 /*
66 * Loop over logs of extent sizes.
67 */
68 for (log = low; log <= high; log++) {
69 /*
70 * Get one summary datum.
71 */
72 error = xfs_rtget_summary(mp, tp, log, bbno, rbpp, rsb, &sum);
73 if (error) {
74 return error;
75 }
76 /*
77 * If there are any, return success.
78 */
79 if (sum) {
80 *stat = 1;
81 goto out;
82 }
83 }
84 /*
85 * Found nothing, return failure.
86 */
87 *stat = 0;
88out:
89 /* There were no extents at levels < log. */
90 if (mp->m_rsum_cache && log > mp->m_rsum_cache[bbno])
91 mp->m_rsum_cache[bbno] = log;
92 return 0;
93}
94
95
96/*
97 * Copy and transform the summary file, given the old and new
98 * parameters in the mount structures.
99 */
100STATIC int /* error */
101xfs_rtcopy_summary(
102 xfs_mount_t *omp, /* old file system mount point */
103 xfs_mount_t *nmp, /* new file system mount point */
104 xfs_trans_t *tp) /* transaction pointer */
105{
106 xfs_rtblock_t bbno; /* bitmap block number */
107 struct xfs_buf *bp; /* summary buffer */
108 int error; /* error return value */
109 int log; /* summary level number (log length) */
110 xfs_suminfo_t sum; /* summary data */
111 xfs_fsblock_t sumbno; /* summary block number */
112
113 bp = NULL;
114 for (log = omp->m_rsumlevels - 1; log >= 0; log--) {
115 for (bbno = omp->m_sb.sb_rbmblocks - 1;
116 (xfs_srtblock_t)bbno >= 0;
117 bbno--) {
118 error = xfs_rtget_summary(omp, tp, log, bbno, &bp,
119 &sumbno, &sum);
120 if (error)
121 return error;
122 if (sum == 0)
123 continue;
124 error = xfs_rtmodify_summary(omp, tp, log, bbno, -sum,
125 &bp, &sumbno);
126 if (error)
127 return error;
128 error = xfs_rtmodify_summary(nmp, tp, log, bbno, sum,
129 &bp, &sumbno);
130 if (error)
131 return error;
132 ASSERT(sum > 0);
133 }
134 }
135 return 0;
136}
137/*
138 * Mark an extent specified by start and len allocated.
139 * Updates all the summary information as well as the bitmap.
140 */
141STATIC int /* error */
142xfs_rtallocate_range(
143 xfs_mount_t *mp, /* file system mount point */
144 xfs_trans_t *tp, /* transaction pointer */
145 xfs_rtblock_t start, /* start block to allocate */
146 xfs_extlen_t len, /* length to allocate */
147 struct xfs_buf **rbpp, /* in/out: summary block buffer */
148 xfs_fsblock_t *rsb) /* in/out: summary block number */
149{
150 xfs_rtblock_t end; /* end of the allocated extent */
151 int error; /* error value */
152 xfs_rtblock_t postblock = 0; /* first block allocated > end */
153 xfs_rtblock_t preblock = 0; /* first block allocated < start */
154
155 end = start + len - 1;
156 /*
157 * Assume we're allocating out of the middle of a free extent.
158 * We need to find the beginning and end of the extent so we can
159 * properly update the summary.
160 */
161 error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
162 if (error) {
163 return error;
164 }
165 /*
166 * Find the next allocated block (end of free extent).
167 */
168 error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
169 &postblock);
170 if (error) {
171 return error;
172 }
173 /*
174 * Decrement the summary information corresponding to the entire
175 * (old) free extent.
176 */
177 error = xfs_rtmodify_summary(mp, tp,
178 XFS_RTBLOCKLOG(postblock + 1 - preblock),
179 XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
180 if (error) {
181 return error;
182 }
183 /*
184 * If there are blocks not being allocated at the front of the
185 * old extent, add summary data for them to be free.
186 */
187 if (preblock < start) {
188 error = xfs_rtmodify_summary(mp, tp,
189 XFS_RTBLOCKLOG(start - preblock),
190 XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
191 if (error) {
192 return error;
193 }
194 }
195 /*
196 * If there are blocks not being allocated at the end of the
197 * old extent, add summary data for them to be free.
198 */
199 if (postblock > end) {
200 error = xfs_rtmodify_summary(mp, tp,
201 XFS_RTBLOCKLOG(postblock - end),
202 XFS_BITTOBLOCK(mp, end + 1), 1, rbpp, rsb);
203 if (error) {
204 return error;
205 }
206 }
207 /*
208 * Modify the bitmap to mark this extent allocated.
209 */
210 error = xfs_rtmodify_range(mp, tp, start, len, 0);
211 return error;
212}
213
214/*
215 * Attempt to allocate an extent minlen<=len<=maxlen starting from
216 * bitmap block bbno. If we don't get maxlen then use prod to trim
217 * the length, if given. Returns error; returns starting block in *rtblock.
218 * The lengths are all in rtextents.
219 */
220STATIC int /* error */
221xfs_rtallocate_extent_block(
222 xfs_mount_t *mp, /* file system mount point */
223 xfs_trans_t *tp, /* transaction pointer */
224 xfs_rtblock_t bbno, /* bitmap block number */
225 xfs_extlen_t minlen, /* minimum length to allocate */
226 xfs_extlen_t maxlen, /* maximum length to allocate */
227 xfs_extlen_t *len, /* out: actual length allocated */
228 xfs_rtblock_t *nextp, /* out: next block to try */
229 struct xfs_buf **rbpp, /* in/out: summary block buffer */
230 xfs_fsblock_t *rsb, /* in/out: summary block number */
231 xfs_extlen_t prod, /* extent product factor */
232 xfs_rtblock_t *rtblock) /* out: start block allocated */
233{
234 xfs_rtblock_t besti; /* best rtblock found so far */
235 xfs_rtblock_t bestlen; /* best length found so far */
236 xfs_rtblock_t end; /* last rtblock in chunk */
237 int error; /* error value */
238 xfs_rtblock_t i; /* current rtblock trying */
239 xfs_rtblock_t next; /* next rtblock to try */
240 int stat; /* status from internal calls */
241
242 /*
243 * Loop over all the extents starting in this bitmap block,
244 * looking for one that's long enough.
245 */
246 for (i = XFS_BLOCKTOBIT(mp, bbno), besti = -1, bestlen = 0,
247 end = XFS_BLOCKTOBIT(mp, bbno + 1) - 1;
248 i <= end;
249 i++) {
250 /* Make sure we don't scan off the end of the rt volume. */
251 maxlen = min(mp->m_sb.sb_rextents, i + maxlen) - i;
252
253 /*
254 * See if there's a free extent of maxlen starting at i.
255 * If it's not so then next will contain the first non-free.
256 */
257 error = xfs_rtcheck_range(mp, tp, i, maxlen, 1, &next, &stat);
258 if (error) {
259 return error;
260 }
261 if (stat) {
262 /*
263 * i for maxlen is all free, allocate and return that.
264 */
265 error = xfs_rtallocate_range(mp, tp, i, maxlen, rbpp,
266 rsb);
267 if (error) {
268 return error;
269 }
270 *len = maxlen;
271 *rtblock = i;
272 return 0;
273 }
274 /*
275 * In the case where we have a variable-sized allocation
276 * request, figure out how big this free piece is,
277 * and if it's big enough for the minimum, and the best
278 * so far, remember it.
279 */
280 if (minlen < maxlen) {
281 xfs_rtblock_t thislen; /* this extent size */
282
283 thislen = next - i;
284 if (thislen >= minlen && thislen > bestlen) {
285 besti = i;
286 bestlen = thislen;
287 }
288 }
289 /*
290 * If not done yet, find the start of the next free space.
291 */
292 if (next < end) {
293 error = xfs_rtfind_forw(mp, tp, next, end, &i);
294 if (error) {
295 return error;
296 }
297 } else
298 break;
299 }
300 /*
301 * Searched the whole thing & didn't find a maxlen free extent.
302 */
303 if (minlen < maxlen && besti != -1) {
304 xfs_extlen_t p; /* amount to trim length by */
305
306 /*
307 * If size should be a multiple of prod, make that so.
308 */
309 if (prod > 1) {
310 div_u64_rem(bestlen, prod, &p);
311 if (p)
312 bestlen -= p;
313 }
314
315 /*
316 * Allocate besti for bestlen & return that.
317 */
318 error = xfs_rtallocate_range(mp, tp, besti, bestlen, rbpp, rsb);
319 if (error) {
320 return error;
321 }
322 *len = bestlen;
323 *rtblock = besti;
324 return 0;
325 }
326 /*
327 * Allocation failed. Set *nextp to the next block to try.
328 */
329 *nextp = next;
330 *rtblock = NULLRTBLOCK;
331 return 0;
332}
333
334/*
335 * Allocate an extent of length minlen<=len<=maxlen, starting at block
336 * bno. If we don't get maxlen then use prod to trim the length, if given.
337 * Returns error; returns starting block in *rtblock.
338 * The lengths are all in rtextents.
339 */
340STATIC int /* error */
341xfs_rtallocate_extent_exact(
342 xfs_mount_t *mp, /* file system mount point */
343 xfs_trans_t *tp, /* transaction pointer */
344 xfs_rtblock_t bno, /* starting block number to allocate */
345 xfs_extlen_t minlen, /* minimum length to allocate */
346 xfs_extlen_t maxlen, /* maximum length to allocate */
347 xfs_extlen_t *len, /* out: actual length allocated */
348 struct xfs_buf **rbpp, /* in/out: summary block buffer */
349 xfs_fsblock_t *rsb, /* in/out: summary block number */
350 xfs_extlen_t prod, /* extent product factor */
351 xfs_rtblock_t *rtblock) /* out: start block allocated */
352{
353 int error; /* error value */
354 xfs_extlen_t i; /* extent length trimmed due to prod */
355 int isfree; /* extent is free */
356 xfs_rtblock_t next; /* next block to try (dummy) */
357
358 ASSERT(minlen % prod == 0 && maxlen % prod == 0);
359 /*
360 * Check if the range in question (for maxlen) is free.
361 */
362 error = xfs_rtcheck_range(mp, tp, bno, maxlen, 1, &next, &isfree);
363 if (error) {
364 return error;
365 }
366 if (isfree) {
367 /*
368 * If it is, allocate it and return success.
369 */
370 error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
371 if (error) {
372 return error;
373 }
374 *len = maxlen;
375 *rtblock = bno;
376 return 0;
377 }
378 /*
379 * If not, allocate what there is, if it's at least minlen.
380 */
381 maxlen = next - bno;
382 if (maxlen < minlen) {
383 /*
384 * Failed, return failure status.
385 */
386 *rtblock = NULLRTBLOCK;
387 return 0;
388 }
389 /*
390 * Trim off tail of extent, if prod is specified.
391 */
392 if (prod > 1 && (i = maxlen % prod)) {
393 maxlen -= i;
394 if (maxlen < minlen) {
395 /*
396 * Now we can't do it, return failure status.
397 */
398 *rtblock = NULLRTBLOCK;
399 return 0;
400 }
401 }
402 /*
403 * Allocate what we can and return it.
404 */
405 error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
406 if (error) {
407 return error;
408 }
409 *len = maxlen;
410 *rtblock = bno;
411 return 0;
412}
413
414/*
415 * Allocate an extent of length minlen<=len<=maxlen, starting as near
416 * to bno as possible. If we don't get maxlen then use prod to trim
417 * the length, if given. The lengths are all in rtextents.
418 */
419STATIC int /* error */
420xfs_rtallocate_extent_near(
421 xfs_mount_t *mp, /* file system mount point */
422 xfs_trans_t *tp, /* transaction pointer */
423 xfs_rtblock_t bno, /* starting block number to allocate */
424 xfs_extlen_t minlen, /* minimum length to allocate */
425 xfs_extlen_t maxlen, /* maximum length to allocate */
426 xfs_extlen_t *len, /* out: actual length allocated */
427 struct xfs_buf **rbpp, /* in/out: summary block buffer */
428 xfs_fsblock_t *rsb, /* in/out: summary block number */
429 xfs_extlen_t prod, /* extent product factor */
430 xfs_rtblock_t *rtblock) /* out: start block allocated */
431{
432 int any; /* any useful extents from summary */
433 xfs_rtblock_t bbno; /* bitmap block number */
434 int error; /* error value */
435 int i; /* bitmap block offset (loop control) */
436 int j; /* secondary loop control */
437 int log2len; /* log2 of minlen */
438 xfs_rtblock_t n; /* next block to try */
439 xfs_rtblock_t r; /* result block */
440
441 ASSERT(minlen % prod == 0 && maxlen % prod == 0);
442 /*
443 * If the block number given is off the end, silently set it to
444 * the last block.
445 */
446 if (bno >= mp->m_sb.sb_rextents)
447 bno = mp->m_sb.sb_rextents - 1;
448
449 /* Make sure we don't run off the end of the rt volume. */
450 maxlen = min(mp->m_sb.sb_rextents, bno + maxlen) - bno;
451 if (maxlen < minlen) {
452 *rtblock = NULLRTBLOCK;
453 return 0;
454 }
455
456 /*
457 * Try the exact allocation first.
458 */
459 error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, len,
460 rbpp, rsb, prod, &r);
461 if (error) {
462 return error;
463 }
464 /*
465 * If the exact allocation worked, return that.
466 */
467 if (r != NULLRTBLOCK) {
468 *rtblock = r;
469 return 0;
470 }
471 bbno = XFS_BITTOBLOCK(mp, bno);
472 i = 0;
473 ASSERT(minlen != 0);
474 log2len = xfs_highbit32(minlen);
475 /*
476 * Loop over all bitmap blocks (bbno + i is current block).
477 */
478 for (;;) {
479 /*
480 * Get summary information of extents of all useful levels
481 * starting in this bitmap block.
482 */
483 error = xfs_rtany_summary(mp, tp, log2len, mp->m_rsumlevels - 1,
484 bbno + i, rbpp, rsb, &any);
485 if (error) {
486 return error;
487 }
488 /*
489 * If there are any useful extents starting here, try
490 * allocating one.
491 */
492 if (any) {
493 /*
494 * On the positive side of the starting location.
495 */
496 if (i >= 0) {
497 /*
498 * Try to allocate an extent starting in
499 * this block.
500 */
501 error = xfs_rtallocate_extent_block(mp, tp,
502 bbno + i, minlen, maxlen, len, &n, rbpp,
503 rsb, prod, &r);
504 if (error) {
505 return error;
506 }
507 /*
508 * If it worked, return it.
509 */
510 if (r != NULLRTBLOCK) {
511 *rtblock = r;
512 return 0;
513 }
514 }
515 /*
516 * On the negative side of the starting location.
517 */
518 else { /* i < 0 */
519 /*
520 * Loop backwards through the bitmap blocks from
521 * the starting point-1 up to where we are now.
522 * There should be an extent which ends in this
523 * bitmap block and is long enough.
524 */
525 for (j = -1; j > i; j--) {
526 /*
527 * Grab the summary information for
528 * this bitmap block.
529 */
530 error = xfs_rtany_summary(mp, tp,
531 log2len, mp->m_rsumlevels - 1,
532 bbno + j, rbpp, rsb, &any);
533 if (error) {
534 return error;
535 }
536 /*
537 * If there's no extent given in the
538 * summary that means the extent we
539 * found must carry over from an
540 * earlier block. If there is an
541 * extent given, we've already tried
542 * that allocation, don't do it again.
543 */
544 if (any)
545 continue;
546 error = xfs_rtallocate_extent_block(mp,
547 tp, bbno + j, minlen, maxlen,
548 len, &n, rbpp, rsb, prod, &r);
549 if (error) {
550 return error;
551 }
552 /*
553 * If it works, return the extent.
554 */
555 if (r != NULLRTBLOCK) {
556 *rtblock = r;
557 return 0;
558 }
559 }
560 /*
561 * There weren't intervening bitmap blocks
562 * with a long enough extent, or the
563 * allocation didn't work for some reason
564 * (i.e. it's a little * too short).
565 * Try to allocate from the summary block
566 * that we found.
567 */
568 error = xfs_rtallocate_extent_block(mp, tp,
569 bbno + i, minlen, maxlen, len, &n, rbpp,
570 rsb, prod, &r);
571 if (error) {
572 return error;
573 }
574 /*
575 * If it works, return the extent.
576 */
577 if (r != NULLRTBLOCK) {
578 *rtblock = r;
579 return 0;
580 }
581 }
582 }
583 /*
584 * Loop control. If we were on the positive side, and there's
585 * still more blocks on the negative side, go there.
586 */
587 if (i > 0 && (int)bbno - i >= 0)
588 i = -i;
589 /*
590 * If positive, and no more negative, but there are more
591 * positive, go there.
592 */
593 else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
594 i++;
595 /*
596 * If negative or 0 (just started), and there are positive
597 * blocks to go, go there. The 0 case moves to block 1.
598 */
599 else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
600 i = 1 - i;
601 /*
602 * If negative or 0 and there are more negative blocks,
603 * go there.
604 */
605 else if (i <= 0 && (int)bbno + i > 0)
606 i--;
607 /*
608 * Must be done. Return failure.
609 */
610 else
611 break;
612 }
613 *rtblock = NULLRTBLOCK;
614 return 0;
615}
616
617/*
618 * Allocate an extent of length minlen<=len<=maxlen, with no position
619 * specified. If we don't get maxlen then use prod to trim
620 * the length, if given. The lengths are all in rtextents.
621 */
622STATIC int /* error */
623xfs_rtallocate_extent_size(
624 xfs_mount_t *mp, /* file system mount point */
625 xfs_trans_t *tp, /* transaction pointer */
626 xfs_extlen_t minlen, /* minimum length to allocate */
627 xfs_extlen_t maxlen, /* maximum length to allocate */
628 xfs_extlen_t *len, /* out: actual length allocated */
629 struct xfs_buf **rbpp, /* in/out: summary block buffer */
630 xfs_fsblock_t *rsb, /* in/out: summary block number */
631 xfs_extlen_t prod, /* extent product factor */
632 xfs_rtblock_t *rtblock) /* out: start block allocated */
633{
634 int error; /* error value */
635 int i; /* bitmap block number */
636 int l; /* level number (loop control) */
637 xfs_rtblock_t n; /* next block to be tried */
638 xfs_rtblock_t r; /* result block number */
639 xfs_suminfo_t sum; /* summary information for extents */
640
641 ASSERT(minlen % prod == 0 && maxlen % prod == 0);
642 ASSERT(maxlen != 0);
643
644 /*
645 * Loop over all the levels starting with maxlen.
646 * At each level, look at all the bitmap blocks, to see if there
647 * are extents starting there that are long enough (>= maxlen).
648 * Note, only on the initial level can the allocation fail if
649 * the summary says there's an extent.
650 */
651 for (l = xfs_highbit32(maxlen); l < mp->m_rsumlevels; l++) {
652 /*
653 * Loop over all the bitmap blocks.
654 */
655 for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
656 /*
657 * Get the summary for this level/block.
658 */
659 error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
660 &sum);
661 if (error) {
662 return error;
663 }
664 /*
665 * Nothing there, on to the next block.
666 */
667 if (!sum)
668 continue;
669 /*
670 * Try allocating the extent.
671 */
672 error = xfs_rtallocate_extent_block(mp, tp, i, maxlen,
673 maxlen, len, &n, rbpp, rsb, prod, &r);
674 if (error) {
675 return error;
676 }
677 /*
678 * If it worked, return that.
679 */
680 if (r != NULLRTBLOCK) {
681 *rtblock = r;
682 return 0;
683 }
684 /*
685 * If the "next block to try" returned from the
686 * allocator is beyond the next bitmap block,
687 * skip to that bitmap block.
688 */
689 if (XFS_BITTOBLOCK(mp, n) > i + 1)
690 i = XFS_BITTOBLOCK(mp, n) - 1;
691 }
692 }
693 /*
694 * Didn't find any maxlen blocks. Try smaller ones, unless
695 * we're asking for a fixed size extent.
696 */
697 if (minlen > --maxlen) {
698 *rtblock = NULLRTBLOCK;
699 return 0;
700 }
701 ASSERT(minlen != 0);
702 ASSERT(maxlen != 0);
703
704 /*
705 * Loop over sizes, from maxlen down to minlen.
706 * This time, when we do the allocations, allow smaller ones
707 * to succeed.
708 */
709 for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
710 /*
711 * Loop over all the bitmap blocks, try an allocation
712 * starting in that block.
713 */
714 for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
715 /*
716 * Get the summary information for this level/block.
717 */
718 error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
719 &sum);
720 if (error) {
721 return error;
722 }
723 /*
724 * If nothing there, go on to next.
725 */
726 if (!sum)
727 continue;
728 /*
729 * Try the allocation. Make sure the specified
730 * minlen/maxlen are in the possible range for
731 * this summary level.
732 */
733 error = xfs_rtallocate_extent_block(mp, tp, i,
734 XFS_RTMAX(minlen, 1 << l),
735 XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
736 len, &n, rbpp, rsb, prod, &r);
737 if (error) {
738 return error;
739 }
740 /*
741 * If it worked, return that extent.
742 */
743 if (r != NULLRTBLOCK) {
744 *rtblock = r;
745 return 0;
746 }
747 /*
748 * If the "next block to try" returned from the
749 * allocator is beyond the next bitmap block,
750 * skip to that bitmap block.
751 */
752 if (XFS_BITTOBLOCK(mp, n) > i + 1)
753 i = XFS_BITTOBLOCK(mp, n) - 1;
754 }
755 }
756 /*
757 * Got nothing, return failure.
758 */
759 *rtblock = NULLRTBLOCK;
760 return 0;
761}
762
763/*
764 * Allocate space to the bitmap or summary file, and zero it, for growfs.
765 */
766STATIC int
767xfs_growfs_rt_alloc(
768 struct xfs_mount *mp, /* file system mount point */
769 xfs_extlen_t oblocks, /* old count of blocks */
770 xfs_extlen_t nblocks, /* new count of blocks */
771 struct xfs_inode *ip) /* inode (bitmap/summary) */
772{
773 xfs_fileoff_t bno; /* block number in file */
774 struct xfs_buf *bp; /* temporary buffer for zeroing */
775 xfs_daddr_t d; /* disk block address */
776 int error; /* error return value */
777 xfs_fsblock_t fsbno; /* filesystem block for bno */
778 struct xfs_bmbt_irec map; /* block map output */
779 int nmap; /* number of block maps */
780 int resblks; /* space reservation */
781 enum xfs_blft buf_type;
782 struct xfs_trans *tp;
783
784 if (ip == mp->m_rsumip)
785 buf_type = XFS_BLFT_RTSUMMARY_BUF;
786 else
787 buf_type = XFS_BLFT_RTBITMAP_BUF;
788
789 /*
790 * Allocate space to the file, as necessary.
791 */
792 while (oblocks < nblocks) {
793 resblks = XFS_GROWFSRT_SPACE_RES(mp, nblocks - oblocks);
794 /*
795 * Reserve space & log for one extent added to the file.
796 */
797 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtalloc, resblks,
798 0, 0, &tp);
799 if (error)
800 return error;
801 /*
802 * Lock the inode.
803 */
804 xfs_ilock(ip, XFS_ILOCK_EXCL);
805 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
806
807 error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
808 XFS_IEXT_ADD_NOSPLIT_CNT);
809 if (error)
810 goto out_trans_cancel;
811
812 /*
813 * Allocate blocks to the bitmap file.
814 */
815 nmap = 1;
816 error = xfs_bmapi_write(tp, ip, oblocks, nblocks - oblocks,
817 XFS_BMAPI_METADATA, 0, &map, &nmap);
818 if (!error && nmap < 1)
819 error = -ENOSPC;
820 if (error)
821 goto out_trans_cancel;
822 /*
823 * Free any blocks freed up in the transaction, then commit.
824 */
825 error = xfs_trans_commit(tp);
826 if (error)
827 return error;
828 /*
829 * Now we need to clear the allocated blocks.
830 * Do this one block per transaction, to keep it simple.
831 */
832 for (bno = map.br_startoff, fsbno = map.br_startblock;
833 bno < map.br_startoff + map.br_blockcount;
834 bno++, fsbno++) {
835 /*
836 * Reserve log for one block zeroing.
837 */
838 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtzero,
839 0, 0, 0, &tp);
840 if (error)
841 return error;
842 /*
843 * Lock the bitmap inode.
844 */
845 xfs_ilock(ip, XFS_ILOCK_EXCL);
846 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
847 /*
848 * Get a buffer for the block.
849 */
850 d = XFS_FSB_TO_DADDR(mp, fsbno);
851 error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
852 mp->m_bsize, 0, &bp);
853 if (error)
854 goto out_trans_cancel;
855
856 xfs_trans_buf_set_type(tp, bp, buf_type);
857 bp->b_ops = &xfs_rtbuf_ops;
858 memset(bp->b_addr, 0, mp->m_sb.sb_blocksize);
859 xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
860 /*
861 * Commit the transaction.
862 */
863 error = xfs_trans_commit(tp);
864 if (error)
865 return error;
866 }
867 /*
868 * Go on to the next extent, if any.
869 */
870 oblocks = map.br_startoff + map.br_blockcount;
871 }
872
873 return 0;
874
875out_trans_cancel:
876 xfs_trans_cancel(tp);
877 return error;
878}
879
880static void
881xfs_alloc_rsum_cache(
882 xfs_mount_t *mp, /* file system mount structure */
883 xfs_extlen_t rbmblocks) /* number of rt bitmap blocks */
884{
885 /*
886 * The rsum cache is initialized to all zeroes, which is trivially a
887 * lower bound on the minimum level with any free extents. We can
888 * continue without the cache if it couldn't be allocated.
889 */
890 mp->m_rsum_cache = kvzalloc(rbmblocks, GFP_KERNEL);
891 if (!mp->m_rsum_cache)
892 xfs_warn(mp, "could not allocate realtime summary cache");
893}
894
895/*
896 * Visible (exported) functions.
897 */
898
899/*
900 * Grow the realtime area of the filesystem.
901 */
902int
903xfs_growfs_rt(
904 xfs_mount_t *mp, /* mount point for filesystem */
905 xfs_growfs_rt_t *in) /* growfs rt input struct */
906{
907 xfs_rtblock_t bmbno; /* bitmap block number */
908 struct xfs_buf *bp; /* temporary buffer */
909 int error; /* error return value */
910 xfs_mount_t *nmp; /* new (fake) mount structure */
911 xfs_rfsblock_t nrblocks; /* new number of realtime blocks */
912 xfs_extlen_t nrbmblocks; /* new number of rt bitmap blocks */
913 xfs_rtblock_t nrextents; /* new number of realtime extents */
914 uint8_t nrextslog; /* new log2 of sb_rextents */
915 xfs_extlen_t nrsumblocks; /* new number of summary blocks */
916 uint nrsumlevels; /* new rt summary levels */
917 uint nrsumsize; /* new size of rt summary, bytes */
918 xfs_sb_t *nsbp; /* new superblock */
919 xfs_extlen_t rbmblocks; /* current number of rt bitmap blocks */
920 xfs_extlen_t rsumblocks; /* current number of rt summary blks */
921 xfs_sb_t *sbp; /* old superblock */
922 xfs_fsblock_t sumbno; /* summary block number */
923 uint8_t *rsum_cache; /* old summary cache */
924
925 sbp = &mp->m_sb;
926
927 if (!capable(CAP_SYS_ADMIN))
928 return -EPERM;
929
930 /* Needs to have been mounted with an rt device. */
931 if (!XFS_IS_REALTIME_MOUNT(mp))
932 return -EINVAL;
933 /*
934 * Mount should fail if the rt bitmap/summary files don't load, but
935 * we'll check anyway.
936 */
937 if (!mp->m_rbmip || !mp->m_rsumip)
938 return -EINVAL;
939
940 /* Shrink not supported. */
941 if (in->newblocks <= sbp->sb_rblocks)
942 return -EINVAL;
943
944 /* Can only change rt extent size when adding rt volume. */
945 if (sbp->sb_rblocks > 0 && in->extsize != sbp->sb_rextsize)
946 return -EINVAL;
947
948 /* Range check the extent size. */
949 if (XFS_FSB_TO_B(mp, in->extsize) > XFS_MAX_RTEXTSIZE ||
950 XFS_FSB_TO_B(mp, in->extsize) < XFS_MIN_RTEXTSIZE)
951 return -EINVAL;
952
953 /* Unsupported realtime features. */
954 if (xfs_sb_version_hasrmapbt(&mp->m_sb) ||
955 xfs_sb_version_hasreflink(&mp->m_sb))
956 return -EOPNOTSUPP;
957
958 nrblocks = in->newblocks;
959 error = xfs_sb_validate_fsb_count(sbp, nrblocks);
960 if (error)
961 return error;
962 /*
963 * Read in the last block of the device, make sure it exists.
964 */
965 error = xfs_buf_read_uncached(mp->m_rtdev_targp,
966 XFS_FSB_TO_BB(mp, nrblocks - 1),
967 XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
968 if (error)
969 return error;
970 xfs_buf_relse(bp);
971
972 /*
973 * Calculate new parameters. These are the final values to be reached.
974 */
975 nrextents = nrblocks;
976 do_div(nrextents, in->extsize);
977 nrbmblocks = howmany_64(nrextents, NBBY * sbp->sb_blocksize);
978 nrextslog = xfs_highbit32(nrextents);
979 nrsumlevels = nrextslog + 1;
980 nrsumsize = (uint)sizeof(xfs_suminfo_t) * nrsumlevels * nrbmblocks;
981 nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
982 nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
983 /*
984 * New summary size can't be more than half the size of
985 * the log. This prevents us from getting a log overflow,
986 * since we'll log basically the whole summary file at once.
987 */
988 if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1))
989 return -EINVAL;
990 /*
991 * Get the old block counts for bitmap and summary inodes.
992 * These can't change since other growfs callers are locked out.
993 */
994 rbmblocks = XFS_B_TO_FSB(mp, mp->m_rbmip->i_disk_size);
995 rsumblocks = XFS_B_TO_FSB(mp, mp->m_rsumip->i_disk_size);
996 /*
997 * Allocate space to the bitmap and summary files, as necessary.
998 */
999 error = xfs_growfs_rt_alloc(mp, rbmblocks, nrbmblocks, mp->m_rbmip);
1000 if (error)
1001 return error;
1002 error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip);
1003 if (error)
1004 return error;
1005
1006 rsum_cache = mp->m_rsum_cache;
1007 if (nrbmblocks != sbp->sb_rbmblocks)
1008 xfs_alloc_rsum_cache(mp, nrbmblocks);
1009
1010 /*
1011 * Allocate a new (fake) mount/sb.
1012 */
1013 nmp = kmem_alloc(sizeof(*nmp), 0);
1014 /*
1015 * Loop over the bitmap blocks.
1016 * We will do everything one bitmap block at a time.
1017 * Skip the current block if it is exactly full.
1018 * This also deals with the case where there were no rtextents before.
1019 */
1020 for (bmbno = sbp->sb_rbmblocks -
1021 ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
1022 bmbno < nrbmblocks;
1023 bmbno++) {
1024 struct xfs_trans *tp;
1025 xfs_rfsblock_t nrblocks_step;
1026
1027 *nmp = *mp;
1028 nsbp = &nmp->m_sb;
1029 /*
1030 * Calculate new sb and mount fields for this round.
1031 */
1032 nsbp->sb_rextsize = in->extsize;
1033 nsbp->sb_rbmblocks = bmbno + 1;
1034 nrblocks_step = (bmbno + 1) * NBBY * nsbp->sb_blocksize *
1035 nsbp->sb_rextsize;
1036 nsbp->sb_rblocks = min(nrblocks, nrblocks_step);
1037 nsbp->sb_rextents = nsbp->sb_rblocks;
1038 do_div(nsbp->sb_rextents, nsbp->sb_rextsize);
1039 ASSERT(nsbp->sb_rextents != 0);
1040 nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents);
1041 nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
1042 nrsumsize =
1043 (uint)sizeof(xfs_suminfo_t) * nrsumlevels *
1044 nsbp->sb_rbmblocks;
1045 nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
1046 nmp->m_rsumsize = nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
1047 /*
1048 * Start a transaction, get the log reservation.
1049 */
1050 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtfree, 0, 0, 0,
1051 &tp);
1052 if (error)
1053 break;
1054 /*
1055 * Lock out other callers by grabbing the bitmap inode lock.
1056 */
1057 xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
1058 xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
1059 /*
1060 * Update the bitmap inode's size ondisk and incore. We need
1061 * to update the incore size so that inode inactivation won't
1062 * punch what it thinks are "posteof" blocks.
1063 */
1064 mp->m_rbmip->i_disk_size =
1065 nsbp->sb_rbmblocks * nsbp->sb_blocksize;
1066 i_size_write(VFS_I(mp->m_rbmip), mp->m_rbmip->i_disk_size);
1067 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1068 /*
1069 * Get the summary inode into the transaction.
1070 */
1071 xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
1072 xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
1073 /*
1074 * Update the summary inode's size. We need to update the
1075 * incore size so that inode inactivation won't punch what it
1076 * thinks are "posteof" blocks.
1077 */
1078 mp->m_rsumip->i_disk_size = nmp->m_rsumsize;
1079 i_size_write(VFS_I(mp->m_rsumip), mp->m_rsumip->i_disk_size);
1080 xfs_trans_log_inode(tp, mp->m_rsumip, XFS_ILOG_CORE);
1081 /*
1082 * Copy summary data from old to new sizes.
1083 * Do this when the real size (not block-aligned) changes.
1084 */
1085 if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
1086 mp->m_rsumlevels != nmp->m_rsumlevels) {
1087 error = xfs_rtcopy_summary(mp, nmp, tp);
1088 if (error)
1089 goto error_cancel;
1090 }
1091 /*
1092 * Update superblock fields.
1093 */
1094 if (nsbp->sb_rextsize != sbp->sb_rextsize)
1095 xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
1096 nsbp->sb_rextsize - sbp->sb_rextsize);
1097 if (nsbp->sb_rbmblocks != sbp->sb_rbmblocks)
1098 xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
1099 nsbp->sb_rbmblocks - sbp->sb_rbmblocks);
1100 if (nsbp->sb_rblocks != sbp->sb_rblocks)
1101 xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
1102 nsbp->sb_rblocks - sbp->sb_rblocks);
1103 if (nsbp->sb_rextents != sbp->sb_rextents)
1104 xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
1105 nsbp->sb_rextents - sbp->sb_rextents);
1106 if (nsbp->sb_rextslog != sbp->sb_rextslog)
1107 xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
1108 nsbp->sb_rextslog - sbp->sb_rextslog);
1109 /*
1110 * Free new extent.
1111 */
1112 bp = NULL;
1113 error = xfs_rtfree_range(nmp, tp, sbp->sb_rextents,
1114 nsbp->sb_rextents - sbp->sb_rextents, &bp, &sumbno);
1115 if (error) {
1116error_cancel:
1117 xfs_trans_cancel(tp);
1118 break;
1119 }
1120 /*
1121 * Mark more blocks free in the superblock.
1122 */
1123 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS,
1124 nsbp->sb_rextents - sbp->sb_rextents);
1125 /*
1126 * Update mp values into the real mp structure.
1127 */
1128 mp->m_rsumlevels = nrsumlevels;
1129 mp->m_rsumsize = nrsumsize;
1130
1131 error = xfs_trans_commit(tp);
1132 if (error)
1133 break;
1134 }
1135 if (error)
1136 goto out_free;
1137
1138 /* Update secondary superblocks now the physical grow has completed */
1139 error = xfs_update_secondary_sbs(mp);
1140
1141out_free:
1142 /*
1143 * Free the fake mp structure.
1144 */
1145 kmem_free(nmp);
1146
1147 /*
1148 * If we had to allocate a new rsum_cache, we either need to free the
1149 * old one (if we succeeded) or free the new one and restore the old one
1150 * (if there was an error).
1151 */
1152 if (rsum_cache != mp->m_rsum_cache) {
1153 if (error) {
1154 kmem_free(mp->m_rsum_cache);
1155 mp->m_rsum_cache = rsum_cache;
1156 } else {
1157 kmem_free(rsum_cache);
1158 }
1159 }
1160
1161 return error;
1162}
1163
1164/*
1165 * Allocate an extent in the realtime subvolume, with the usual allocation
1166 * parameters. The length units are all in realtime extents, as is the
1167 * result block number.
1168 */
1169int /* error */
1170xfs_rtallocate_extent(
1171 xfs_trans_t *tp, /* transaction pointer */
1172 xfs_rtblock_t bno, /* starting block number to allocate */
1173 xfs_extlen_t minlen, /* minimum length to allocate */
1174 xfs_extlen_t maxlen, /* maximum length to allocate */
1175 xfs_extlen_t *len, /* out: actual length allocated */
1176 int wasdel, /* was a delayed allocation extent */
1177 xfs_extlen_t prod, /* extent product factor */
1178 xfs_rtblock_t *rtblock) /* out: start block allocated */
1179{
1180 xfs_mount_t *mp = tp->t_mountp;
1181 int error; /* error value */
1182 xfs_rtblock_t r; /* result allocated block */
1183 xfs_fsblock_t sb; /* summary file block number */
1184 struct xfs_buf *sumbp; /* summary file block buffer */
1185
1186 ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
1187 ASSERT(minlen > 0 && minlen <= maxlen);
1188
1189 /*
1190 * If prod is set then figure out what to do to minlen and maxlen.
1191 */
1192 if (prod > 1) {
1193 xfs_extlen_t i;
1194
1195 if ((i = maxlen % prod))
1196 maxlen -= i;
1197 if ((i = minlen % prod))
1198 minlen += prod - i;
1199 if (maxlen < minlen) {
1200 *rtblock = NULLRTBLOCK;
1201 return 0;
1202 }
1203 }
1204
1205retry:
1206 sumbp = NULL;
1207 if (bno == 0) {
1208 error = xfs_rtallocate_extent_size(mp, tp, minlen, maxlen, len,
1209 &sumbp, &sb, prod, &r);
1210 } else {
1211 error = xfs_rtallocate_extent_near(mp, tp, bno, minlen, maxlen,
1212 len, &sumbp, &sb, prod, &r);
1213 }
1214
1215 if (error)
1216 return error;
1217
1218 /*
1219 * If it worked, update the superblock.
1220 */
1221 if (r != NULLRTBLOCK) {
1222 long slen = (long)*len;
1223
1224 ASSERT(*len >= minlen && *len <= maxlen);
1225 if (wasdel)
1226 xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FREXTENTS, -slen);
1227 else
1228 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, -slen);
1229 } else if (prod > 1) {
1230 prod = 1;
1231 goto retry;
1232 }
1233
1234 *rtblock = r;
1235 return 0;
1236}
1237
1238/*
1239 * Initialize realtime fields in the mount structure.
1240 */
1241int /* error */
1242xfs_rtmount_init(
1243 struct xfs_mount *mp) /* file system mount structure */
1244{
1245 struct xfs_buf *bp; /* buffer for last block of subvolume */
1246 struct xfs_sb *sbp; /* filesystem superblock copy in mount */
1247 xfs_daddr_t d; /* address of last block of subvolume */
1248 int error;
1249
1250 sbp = &mp->m_sb;
1251 if (sbp->sb_rblocks == 0)
1252 return 0;
1253 if (mp->m_rtdev_targp == NULL) {
1254 xfs_warn(mp,
1255 "Filesystem has a realtime volume, use rtdev=device option");
1256 return -ENODEV;
1257 }
1258 mp->m_rsumlevels = sbp->sb_rextslog + 1;
1259 mp->m_rsumsize =
1260 (uint)sizeof(xfs_suminfo_t) * mp->m_rsumlevels *
1261 sbp->sb_rbmblocks;
1262 mp->m_rsumsize = roundup(mp->m_rsumsize, sbp->sb_blocksize);
1263 mp->m_rbmip = mp->m_rsumip = NULL;
1264 /*
1265 * Check that the realtime section is an ok size.
1266 */
1267 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
1268 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_rblocks) {
1269 xfs_warn(mp, "realtime mount -- %llu != %llu",
1270 (unsigned long long) XFS_BB_TO_FSB(mp, d),
1271 (unsigned long long) mp->m_sb.sb_rblocks);
1272 return -EFBIG;
1273 }
1274 error = xfs_buf_read_uncached(mp->m_rtdev_targp,
1275 d - XFS_FSB_TO_BB(mp, 1),
1276 XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
1277 if (error) {
1278 xfs_warn(mp, "realtime device size check failed");
1279 return error;
1280 }
1281 xfs_buf_relse(bp);
1282 return 0;
1283}
1284
1285/*
1286 * Get the bitmap and summary inodes and the summary cache into the mount
1287 * structure at mount time.
1288 */
1289int /* error */
1290xfs_rtmount_inodes(
1291 xfs_mount_t *mp) /* file system mount structure */
1292{
1293 int error; /* error return value */
1294 xfs_sb_t *sbp;
1295
1296 sbp = &mp->m_sb;
1297 error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip);
1298 if (error)
1299 return error;
1300 ASSERT(mp->m_rbmip != NULL);
1301
1302 error = xfs_iget(mp, NULL, sbp->sb_rsumino, 0, 0, &mp->m_rsumip);
1303 if (error) {
1304 xfs_irele(mp->m_rbmip);
1305 return error;
1306 }
1307 ASSERT(mp->m_rsumip != NULL);
1308 xfs_alloc_rsum_cache(mp, sbp->sb_rbmblocks);
1309 return 0;
1310}
1311
1312void
1313xfs_rtunmount_inodes(
1314 struct xfs_mount *mp)
1315{
1316 kmem_free(mp->m_rsum_cache);
1317 if (mp->m_rbmip)
1318 xfs_irele(mp->m_rbmip);
1319 if (mp->m_rsumip)
1320 xfs_irele(mp->m_rsumip);
1321}
1322
1323/*
1324 * Pick an extent for allocation at the start of a new realtime file.
1325 * Use the sequence number stored in the atime field of the bitmap inode.
1326 * Translate this to a fraction of the rtextents, and return the product
1327 * of rtextents and the fraction.
1328 * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
1329 */
1330int /* error */
1331xfs_rtpick_extent(
1332 xfs_mount_t *mp, /* file system mount point */
1333 xfs_trans_t *tp, /* transaction pointer */
1334 xfs_extlen_t len, /* allocation length (rtextents) */
1335 xfs_rtblock_t *pick) /* result rt extent */
1336{
1337 xfs_rtblock_t b; /* result block */
1338 int log2; /* log of sequence number */
1339 uint64_t resid; /* residual after log removed */
1340 uint64_t seq; /* sequence number of file creation */
1341 uint64_t *seqp; /* pointer to seqno in inode */
1342
1343 ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
1344
1345 seqp = (uint64_t *)&VFS_I(mp->m_rbmip)->i_atime;
1346 if (!(mp->m_rbmip->i_diflags & XFS_DIFLAG_NEWRTBM)) {
1347 mp->m_rbmip->i_diflags |= XFS_DIFLAG_NEWRTBM;
1348 *seqp = 0;
1349 }
1350 seq = *seqp;
1351 if ((log2 = xfs_highbit64(seq)) == -1)
1352 b = 0;
1353 else {
1354 resid = seq - (1ULL << log2);
1355 b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >>
1356 (log2 + 1);
1357 if (b >= mp->m_sb.sb_rextents)
1358 div64_u64_rem(b, mp->m_sb.sb_rextents, &b);
1359 if (b + len > mp->m_sb.sb_rextents)
1360 b = mp->m_sb.sb_rextents - len;
1361 }
1362 *seqp = seq + 1;
1363 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1364 *pick = b;
1365 return 0;
1366}