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_trans.h"
17 #include "xfs_rtalloc.h"
18
19
20 /*
21 * Realtime allocator bitmap functions shared with userspace.
22 */
23
24 /*
25 * Real time buffers need verifiers to avoid runtime warnings during IO.
26 * We don't have anything to verify, however, so these are just dummy
27 * operations.
28 */
29 static void
30 xfs_rtbuf_verify_read(
31 struct xfs_buf *bp)
32 {
33 return;
34 }
35
36 static void
37 xfs_rtbuf_verify_write(
38 struct xfs_buf *bp)
39 {
40 return;
41 }
42
43 const struct xfs_buf_ops xfs_rtbuf_ops = {
44 .name = "rtbuf",
45 .verify_read = xfs_rtbuf_verify_read,
46 .verify_write = xfs_rtbuf_verify_write,
47 };
48
49 /*
50 * Get a buffer for the bitmap or summary file block specified.
51 * The buffer is returned read and locked.
52 */
53 int
54 xfs_rtbuf_get(
55 xfs_mount_t *mp, /* file system mount structure */
56 xfs_trans_t *tp, /* transaction pointer */
57 xfs_rtblock_t block, /* block number in bitmap or summary */
58 int issum, /* is summary not bitmap */
59 xfs_buf_t **bpp) /* output: buffer for the block */
60 {
61 xfs_buf_t *bp; /* block buffer, result */
62 xfs_inode_t *ip; /* bitmap or summary inode */
63 xfs_bmbt_irec_t map;
64 int nmap = 1;
65 int error; /* error value */
66
67 ip = issum ? mp->m_rsumip : mp->m_rbmip;
68
69 error = xfs_bmapi_read(ip, block, 1, &map, &nmap, XFS_DATA_FORK);
70 if (error)
71 return error;
72
73 if (nmap == 0 || !xfs_bmap_is_real_extent(&map))
74 return -EFSCORRUPTED;
75
76 ASSERT(map.br_startblock != NULLFSBLOCK);
77 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
78 XFS_FSB_TO_DADDR(mp, map.br_startblock),
79 mp->m_bsize, 0, &bp, &xfs_rtbuf_ops);
80 if (error)
81 return error;
82
83 xfs_trans_buf_set_type(tp, bp, issum ? XFS_BLFT_RTSUMMARY_BUF
84 : XFS_BLFT_RTBITMAP_BUF);
85 *bpp = bp;
86 return 0;
87 }
88
89 /*
90 * Searching backward from start to limit, find the first block whose
91 * allocated/free state is different from start's.
92 */
93 int
94 xfs_rtfind_back(
95 xfs_mount_t *mp, /* file system mount point */
96 xfs_trans_t *tp, /* transaction pointer */
97 xfs_rtblock_t start, /* starting block to look at */
98 xfs_rtblock_t limit, /* last block to look at */
99 xfs_rtblock_t *rtblock) /* out: start block found */
100 {
101 xfs_rtword_t *b; /* current word in buffer */
102 int bit; /* bit number in the word */
103 xfs_rtblock_t block; /* bitmap block number */
104 xfs_buf_t *bp; /* buf for the block */
105 xfs_rtword_t *bufp; /* starting word in buffer */
106 int error; /* error value */
107 xfs_rtblock_t firstbit; /* first useful bit in the word */
108 xfs_rtblock_t i; /* current bit number rel. to start */
109 xfs_rtblock_t len; /* length of inspected area */
110 xfs_rtword_t mask; /* mask of relevant bits for value */
111 xfs_rtword_t want; /* mask for "good" values */
112 xfs_rtword_t wdiff; /* difference from wanted value */
113 int word; /* word number in the buffer */
114
115 /*
116 * Compute and read in starting bitmap block for starting block.
117 */
118 block = XFS_BITTOBLOCK(mp, start);
119 error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
120 if (error) {
121 return error;
122 }
123 bufp = bp->b_addr;
124 /*
125 * Get the first word's index & point to it.
126 */
127 word = XFS_BITTOWORD(mp, start);
128 b = &bufp[word];
129 bit = (int)(start & (XFS_NBWORD - 1));
130 len = start - limit + 1;
131 /*
132 * Compute match value, based on the bit at start: if 1 (free)
133 * then all-ones, else all-zeroes.
134 */
135 want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
136 /*
137 * If the starting position is not word-aligned, deal with the
138 * partial word.
139 */
140 if (bit < XFS_NBWORD - 1) {
141 /*
142 * Calculate first (leftmost) bit number to look at,
143 * and mask for all the relevant bits in this word.
144 */
145 firstbit = XFS_RTMAX((xfs_srtblock_t)(bit - len + 1), 0);
146 mask = (((xfs_rtword_t)1 << (bit - firstbit + 1)) - 1) <<
147 firstbit;
148 /*
149 * Calculate the difference between the value there
150 * and what we're looking for.
151 */
152 if ((wdiff = (*b ^ want) & mask)) {
153 /*
154 * Different. Mark where we are and return.
155 */
156 xfs_trans_brelse(tp, bp);
157 i = bit - XFS_RTHIBIT(wdiff);
158 *rtblock = start - i + 1;
159 return 0;
160 }
161 i = bit - firstbit + 1;
162 /*
163 * Go on to previous block if that's where the previous word is
164 * and we need the previous word.
165 */
166 if (--word == -1 && i < len) {
167 /*
168 * If done with this block, get the previous one.
169 */
170 xfs_trans_brelse(tp, bp);
171 error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
172 if (error) {
173 return error;
174 }
175 bufp = bp->b_addr;
176 word = XFS_BLOCKWMASK(mp);
177 b = &bufp[word];
178 } else {
179 /*
180 * Go on to the previous word in the buffer.
181 */
182 b--;
183 }
184 } else {
185 /*
186 * Starting on a word boundary, no partial word.
187 */
188 i = 0;
189 }
190 /*
191 * Loop over whole words in buffers. When we use up one buffer
192 * we move on to the previous one.
193 */
194 while (len - i >= XFS_NBWORD) {
195 /*
196 * Compute difference between actual and desired value.
197 */
198 if ((wdiff = *b ^ want)) {
199 /*
200 * Different, mark where we are and return.
201 */
202 xfs_trans_brelse(tp, bp);
203 i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
204 *rtblock = start - i + 1;
205 return 0;
206 }
207 i += XFS_NBWORD;
208 /*
209 * Go on to previous block if that's where the previous word is
210 * and we need the previous word.
211 */
212 if (--word == -1 && i < len) {
213 /*
214 * If done with this block, get the previous one.
215 */
216 xfs_trans_brelse(tp, bp);
217 error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
218 if (error) {
219 return error;
220 }
221 bufp = bp->b_addr;
222 word = XFS_BLOCKWMASK(mp);
223 b = &bufp[word];
224 } else {
225 /*
226 * Go on to the previous word in the buffer.
227 */
228 b--;
229 }
230 }
231 /*
232 * If not ending on a word boundary, deal with the last
233 * (partial) word.
234 */
235 if (len - i) {
236 /*
237 * Calculate first (leftmost) bit number to look at,
238 * and mask for all the relevant bits in this word.
239 */
240 firstbit = XFS_NBWORD - (len - i);
241 mask = (((xfs_rtword_t)1 << (len - i)) - 1) << firstbit;
242 /*
243 * Compute difference between actual and desired value.
244 */
245 if ((wdiff = (*b ^ want) & mask)) {
246 /*
247 * Different, mark where we are and return.
248 */
249 xfs_trans_brelse(tp, bp);
250 i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
251 *rtblock = start - i + 1;
252 return 0;
253 } else
254 i = len;
255 }
256 /*
257 * No match, return that we scanned the whole area.
258 */
259 xfs_trans_brelse(tp, bp);
260 *rtblock = start - i + 1;
261 return 0;
262 }
263
264 /*
265 * Searching forward from start to limit, find the first block whose
266 * allocated/free state is different from start's.
267 */
268 int
269 xfs_rtfind_forw(
270 xfs_mount_t *mp, /* file system mount point */
271 xfs_trans_t *tp, /* transaction pointer */
272 xfs_rtblock_t start, /* starting block to look at */
273 xfs_rtblock_t limit, /* last block to look at */
274 xfs_rtblock_t *rtblock) /* out: start block found */
275 {
276 xfs_rtword_t *b; /* current word in buffer */
277 int bit; /* bit number in the word */
278 xfs_rtblock_t block; /* bitmap block number */
279 xfs_buf_t *bp; /* buf for the block */
280 xfs_rtword_t *bufp; /* starting word in buffer */
281 int error; /* error value */
282 xfs_rtblock_t i; /* current bit number rel. to start */
283 xfs_rtblock_t lastbit; /* last useful bit in the word */
284 xfs_rtblock_t len; /* length of inspected area */
285 xfs_rtword_t mask; /* mask of relevant bits for value */
286 xfs_rtword_t want; /* mask for "good" values */
287 xfs_rtword_t wdiff; /* difference from wanted value */
288 int word; /* word number in the buffer */
289
290 /*
291 * Compute and read in starting bitmap block for starting block.
292 */
293 block = XFS_BITTOBLOCK(mp, start);
294 error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
295 if (error) {
296 return error;
297 }
298 bufp = bp->b_addr;
299 /*
300 * Get the first word's index & point to it.
301 */
302 word = XFS_BITTOWORD(mp, start);
303 b = &bufp[word];
304 bit = (int)(start & (XFS_NBWORD - 1));
305 len = limit - start + 1;
306 /*
307 * Compute match value, based on the bit at start: if 1 (free)
308 * then all-ones, else all-zeroes.
309 */
310 want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
311 /*
312 * If the starting position is not word-aligned, deal with the
313 * partial word.
314 */
315 if (bit) {
316 /*
317 * Calculate last (rightmost) bit number to look at,
318 * and mask for all the relevant bits in this word.
319 */
320 lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
321 mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
322 /*
323 * Calculate the difference between the value there
324 * and what we're looking for.
325 */
326 if ((wdiff = (*b ^ want) & mask)) {
327 /*
328 * Different. Mark where we are and return.
329 */
330 xfs_trans_brelse(tp, bp);
331 i = XFS_RTLOBIT(wdiff) - bit;
332 *rtblock = start + i - 1;
333 return 0;
334 }
335 i = lastbit - bit;
336 /*
337 * Go on to next block if that's where the next word is
338 * and we need the next word.
339 */
340 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
341 /*
342 * If done with this block, get the previous one.
343 */
344 xfs_trans_brelse(tp, bp);
345 error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
346 if (error) {
347 return error;
348 }
349 b = bufp = bp->b_addr;
350 word = 0;
351 } else {
352 /*
353 * Go on to the previous word in the buffer.
354 */
355 b++;
356 }
357 } else {
358 /*
359 * Starting on a word boundary, no partial word.
360 */
361 i = 0;
362 }
363 /*
364 * Loop over whole words in buffers. When we use up one buffer
365 * we move on to the next one.
366 */
367 while (len - i >= XFS_NBWORD) {
368 /*
369 * Compute difference between actual and desired value.
370 */
371 if ((wdiff = *b ^ want)) {
372 /*
373 * Different, mark where we are and return.
374 */
375 xfs_trans_brelse(tp, bp);
376 i += XFS_RTLOBIT(wdiff);
377 *rtblock = start + i - 1;
378 return 0;
379 }
380 i += XFS_NBWORD;
381 /*
382 * Go on to next block if that's where the next word is
383 * and we need the next word.
384 */
385 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
386 /*
387 * If done with this block, get the next one.
388 */
389 xfs_trans_brelse(tp, bp);
390 error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
391 if (error) {
392 return error;
393 }
394 b = bufp = bp->b_addr;
395 word = 0;
396 } else {
397 /*
398 * Go on to the next word in the buffer.
399 */
400 b++;
401 }
402 }
403 /*
404 * If not ending on a word boundary, deal with the last
405 * (partial) word.
406 */
407 if ((lastbit = len - i)) {
408 /*
409 * Calculate mask for all the relevant bits in this word.
410 */
411 mask = ((xfs_rtword_t)1 << lastbit) - 1;
412 /*
413 * Compute difference between actual and desired value.
414 */
415 if ((wdiff = (*b ^ want) & mask)) {
416 /*
417 * Different, mark where we are and return.
418 */
419 xfs_trans_brelse(tp, bp);
420 i += XFS_RTLOBIT(wdiff);
421 *rtblock = start + i - 1;
422 return 0;
423 } else
424 i = len;
425 }
426 /*
427 * No match, return that we scanned the whole area.
428 */
429 xfs_trans_brelse(tp, bp);
430 *rtblock = start + i - 1;
431 return 0;
432 }
433
434 /*
435 * Read and/or modify the summary information for a given extent size,
436 * bitmap block combination.
437 * Keeps track of a current summary block, so we don't keep reading
438 * it from the buffer cache.
439 *
440 * Summary information is returned in *sum if specified.
441 * If no delta is specified, returns summary only.
442 */
443 int
444 xfs_rtmodify_summary_int(
445 xfs_mount_t *mp, /* file system mount structure */
446 xfs_trans_t *tp, /* transaction pointer */
447 int log, /* log2 of extent size */
448 xfs_rtblock_t bbno, /* bitmap block number */
449 int delta, /* change to make to summary info */
450 xfs_buf_t **rbpp, /* in/out: summary block buffer */
451 xfs_fsblock_t *rsb, /* in/out: summary block number */
452 xfs_suminfo_t *sum) /* out: summary info for this block */
453 {
454 xfs_buf_t *bp; /* buffer for the summary block */
455 int error; /* error value */
456 xfs_fsblock_t sb; /* summary fsblock */
457 int so; /* index into the summary file */
458 xfs_suminfo_t *sp; /* pointer to returned data */
459
460 /*
461 * Compute entry number in the summary file.
462 */
463 so = XFS_SUMOFFS(mp, log, bbno);
464 /*
465 * Compute the block number in the summary file.
466 */
467 sb = XFS_SUMOFFSTOBLOCK(mp, so);
468 /*
469 * If we have an old buffer, and the block number matches, use that.
470 */
471 if (*rbpp && *rsb == sb)
472 bp = *rbpp;
473 /*
474 * Otherwise we have to get the buffer.
475 */
476 else {
477 /*
478 * If there was an old one, get rid of it first.
479 */
480 if (*rbpp)
481 xfs_trans_brelse(tp, *rbpp);
482 error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
483 if (error) {
484 return error;
485 }
486 /*
487 * Remember this buffer and block for the next call.
488 */
489 *rbpp = bp;
490 *rsb = sb;
491 }
492 /*
493 * Point to the summary information, modify/log it, and/or copy it out.
494 */
495 sp = XFS_SUMPTR(mp, bp, so);
496 if (delta) {
497 uint first = (uint)((char *)sp - (char *)bp->b_addr);
498
499 *sp += delta;
500 if (mp->m_rsum_cache) {
501 if (*sp == 0 && log == mp->m_rsum_cache[bbno])
502 mp->m_rsum_cache[bbno]++;
503 if (*sp != 0 && log < mp->m_rsum_cache[bbno])
504 mp->m_rsum_cache[bbno] = log;
505 }
506 xfs_trans_log_buf(tp, bp, first, first + sizeof(*sp) - 1);
507 }
508 if (sum)
509 *sum = *sp;
510 return 0;
511 }
512
513 int
514 xfs_rtmodify_summary(
515 xfs_mount_t *mp, /* file system mount structure */
516 xfs_trans_t *tp, /* transaction pointer */
517 int log, /* log2 of extent size */
518 xfs_rtblock_t bbno, /* bitmap block number */
519 int delta, /* change to make to summary info */
520 xfs_buf_t **rbpp, /* in/out: summary block buffer */
521 xfs_fsblock_t *rsb) /* in/out: summary block number */
522 {
523 return xfs_rtmodify_summary_int(mp, tp, log, bbno,
524 delta, rbpp, rsb, NULL);
525 }
526
527 /*
528 * Set the given range of bitmap bits to the given value.
529 * Do whatever I/O and logging is required.
530 */
531 int
532 xfs_rtmodify_range(
533 xfs_mount_t *mp, /* file system mount point */
534 xfs_trans_t *tp, /* transaction pointer */
535 xfs_rtblock_t start, /* starting block to modify */
536 xfs_extlen_t len, /* length of extent to modify */
537 int val) /* 1 for free, 0 for allocated */
538 {
539 xfs_rtword_t *b; /* current word in buffer */
540 int bit; /* bit number in the word */
541 xfs_rtblock_t block; /* bitmap block number */
542 xfs_buf_t *bp; /* buf for the block */
543 xfs_rtword_t *bufp; /* starting word in buffer */
544 int error; /* error value */
545 xfs_rtword_t *first; /* first used word in the buffer */
546 int i; /* current bit number rel. to start */
547 int lastbit; /* last useful bit in word */
548 xfs_rtword_t mask; /* mask o frelevant bits for value */
549 int word; /* word number in the buffer */
550
551 /*
552 * Compute starting bitmap block number.
553 */
554 block = XFS_BITTOBLOCK(mp, start);
555 /*
556 * Read the bitmap block, and point to its data.
557 */
558 error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
559 if (error) {
560 return error;
561 }
562 bufp = bp->b_addr;
563 /*
564 * Compute the starting word's address, and starting bit.
565 */
566 word = XFS_BITTOWORD(mp, start);
567 first = b = &bufp[word];
568 bit = (int)(start & (XFS_NBWORD - 1));
569 /*
570 * 0 (allocated) => all zeroes; 1 (free) => all ones.
571 */
572 val = -val;
573 /*
574 * If not starting on a word boundary, deal with the first
575 * (partial) word.
576 */
577 if (bit) {
578 /*
579 * Compute first bit not changed and mask of relevant bits.
580 */
581 lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
582 mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
583 /*
584 * Set/clear the active bits.
585 */
586 if (val)
587 *b |= mask;
588 else
589 *b &= ~mask;
590 i = lastbit - bit;
591 /*
592 * Go on to the next block if that's where the next word is
593 * and we need the next word.
594 */
595 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
596 /*
597 * Log the changed part of this block.
598 * Get the next one.
599 */
600 xfs_trans_log_buf(tp, bp,
601 (uint)((char *)first - (char *)bufp),
602 (uint)((char *)b - (char *)bufp));
603 error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
604 if (error) {
605 return error;
606 }
607 first = b = bufp = bp->b_addr;
608 word = 0;
609 } else {
610 /*
611 * Go on to the next word in the buffer
612 */
613 b++;
614 }
615 } else {
616 /*
617 * Starting on a word boundary, no partial word.
618 */
619 i = 0;
620 }
621 /*
622 * Loop over whole words in buffers. When we use up one buffer
623 * we move on to the next one.
624 */
625 while (len - i >= XFS_NBWORD) {
626 /*
627 * Set the word value correctly.
628 */
629 *b = val;
630 i += XFS_NBWORD;
631 /*
632 * Go on to the next block if that's where the next word is
633 * and we need the next word.
634 */
635 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
636 /*
637 * Log the changed part of this block.
638 * Get the next one.
639 */
640 xfs_trans_log_buf(tp, bp,
641 (uint)((char *)first - (char *)bufp),
642 (uint)((char *)b - (char *)bufp));
643 error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
644 if (error) {
645 return error;
646 }
647 first = b = bufp = bp->b_addr;
648 word = 0;
649 } else {
650 /*
651 * Go on to the next word in the buffer
652 */
653 b++;
654 }
655 }
656 /*
657 * If not ending on a word boundary, deal with the last
658 * (partial) word.
659 */
660 if ((lastbit = len - i)) {
661 /*
662 * Compute a mask of relevant bits.
663 */
664 mask = ((xfs_rtword_t)1 << lastbit) - 1;
665 /*
666 * Set/clear the active bits.
667 */
668 if (val)
669 *b |= mask;
670 else
671 *b &= ~mask;
672 b++;
673 }
674 /*
675 * Log any remaining changed bytes.
676 */
677 if (b > first)
678 xfs_trans_log_buf(tp, bp, (uint)((char *)first - (char *)bufp),
679 (uint)((char *)b - (char *)bufp - 1));
680 return 0;
681 }
682
683 /*
684 * Mark an extent specified by start and len freed.
685 * Updates all the summary information as well as the bitmap.
686 */
687 int
688 xfs_rtfree_range(
689 xfs_mount_t *mp, /* file system mount point */
690 xfs_trans_t *tp, /* transaction pointer */
691 xfs_rtblock_t start, /* starting block to free */
692 xfs_extlen_t len, /* length to free */
693 xfs_buf_t **rbpp, /* in/out: summary block buffer */
694 xfs_fsblock_t *rsb) /* in/out: summary block number */
695 {
696 xfs_rtblock_t end; /* end of the freed extent */
697 int error; /* error value */
698 xfs_rtblock_t postblock; /* first block freed > end */
699 xfs_rtblock_t preblock; /* first block freed < start */
700
701 end = start + len - 1;
702 /*
703 * Modify the bitmap to mark this extent freed.
704 */
705 error = xfs_rtmodify_range(mp, tp, start, len, 1);
706 if (error) {
707 return error;
708 }
709 /*
710 * Assume we're freeing out of the middle of an allocated extent.
711 * We need to find the beginning and end of the extent so we can
712 * properly update the summary.
713 */
714 error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
715 if (error) {
716 return error;
717 }
718 /*
719 * Find the next allocated block (end of allocated extent).
720 */
721 error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
722 &postblock);
723 if (error)
724 return error;
725 /*
726 * If there are blocks not being freed at the front of the
727 * old extent, add summary data for them to be allocated.
728 */
729 if (preblock < start) {
730 error = xfs_rtmodify_summary(mp, tp,
731 XFS_RTBLOCKLOG(start - preblock),
732 XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
733 if (error) {
734 return error;
735 }
736 }
737 /*
738 * If there are blocks not being freed at the end of the
739 * old extent, add summary data for them to be allocated.
740 */
741 if (postblock > end) {
742 error = xfs_rtmodify_summary(mp, tp,
743 XFS_RTBLOCKLOG(postblock - end),
744 XFS_BITTOBLOCK(mp, end + 1), -1, rbpp, rsb);
745 if (error) {
746 return error;
747 }
748 }
749 /*
750 * Increment the summary information corresponding to the entire
751 * (new) free extent.
752 */
753 error = xfs_rtmodify_summary(mp, tp,
754 XFS_RTBLOCKLOG(postblock + 1 - preblock),
755 XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
756 return error;
757 }
758
759 /*
760 * Check that the given range is either all allocated (val = 0) or
761 * all free (val = 1).
762 */
763 int
764 xfs_rtcheck_range(
765 xfs_mount_t *mp, /* file system mount point */
766 xfs_trans_t *tp, /* transaction pointer */
767 xfs_rtblock_t start, /* starting block number of extent */
768 xfs_extlen_t len, /* length of extent */
769 int val, /* 1 for free, 0 for allocated */
770 xfs_rtblock_t *new, /* out: first block not matching */
771 int *stat) /* out: 1 for matches, 0 for not */
772 {
773 xfs_rtword_t *b; /* current word in buffer */
774 int bit; /* bit number in the word */
775 xfs_rtblock_t block; /* bitmap block number */
776 xfs_buf_t *bp; /* buf for the block */
777 xfs_rtword_t *bufp; /* starting word in buffer */
778 int error; /* error value */
779 xfs_rtblock_t i; /* current bit number rel. to start */
780 xfs_rtblock_t lastbit; /* last useful bit in word */
781 xfs_rtword_t mask; /* mask of relevant bits for value */
782 xfs_rtword_t wdiff; /* difference from wanted value */
783 int word; /* word number in the buffer */
784
785 /*
786 * Compute starting bitmap block number
787 */
788 block = XFS_BITTOBLOCK(mp, start);
789 /*
790 * Read the bitmap block.
791 */
792 error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
793 if (error) {
794 return error;
795 }
796 bufp = bp->b_addr;
797 /*
798 * Compute the starting word's address, and starting bit.
799 */
800 word = XFS_BITTOWORD(mp, start);
801 b = &bufp[word];
802 bit = (int)(start & (XFS_NBWORD - 1));
803 /*
804 * 0 (allocated) => all zero's; 1 (free) => all one's.
805 */
806 val = -val;
807 /*
808 * If not starting on a word boundary, deal with the first
809 * (partial) word.
810 */
811 if (bit) {
812 /*
813 * Compute first bit not examined.
814 */
815 lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
816 /*
817 * Mask of relevant bits.
818 */
819 mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
820 /*
821 * Compute difference between actual and desired value.
822 */
823 if ((wdiff = (*b ^ val) & mask)) {
824 /*
825 * Different, compute first wrong bit and return.
826 */
827 xfs_trans_brelse(tp, bp);
828 i = XFS_RTLOBIT(wdiff) - bit;
829 *new = start + i;
830 *stat = 0;
831 return 0;
832 }
833 i = lastbit - bit;
834 /*
835 * Go on to next block if that's where the next word is
836 * and we need the next word.
837 */
838 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
839 /*
840 * If done with this block, get the next one.
841 */
842 xfs_trans_brelse(tp, bp);
843 error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
844 if (error) {
845 return error;
846 }
847 b = bufp = bp->b_addr;
848 word = 0;
849 } else {
850 /*
851 * Go on to the next word in the buffer.
852 */
853 b++;
854 }
855 } else {
856 /*
857 * Starting on a word boundary, no partial word.
858 */
859 i = 0;
860 }
861 /*
862 * Loop over whole words in buffers. When we use up one buffer
863 * we move on to the next one.
864 */
865 while (len - i >= XFS_NBWORD) {
866 /*
867 * Compute difference between actual and desired value.
868 */
869 if ((wdiff = *b ^ val)) {
870 /*
871 * Different, compute first wrong bit and return.
872 */
873 xfs_trans_brelse(tp, bp);
874 i += XFS_RTLOBIT(wdiff);
875 *new = start + i;
876 *stat = 0;
877 return 0;
878 }
879 i += XFS_NBWORD;
880 /*
881 * Go on to next block if that's where the next word is
882 * and we need the next word.
883 */
884 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
885 /*
886 * If done with this block, get the next one.
887 */
888 xfs_trans_brelse(tp, bp);
889 error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
890 if (error) {
891 return error;
892 }
893 b = bufp = bp->b_addr;
894 word = 0;
895 } else {
896 /*
897 * Go on to the next word in the buffer.
898 */
899 b++;
900 }
901 }
902 /*
903 * If not ending on a word boundary, deal with the last
904 * (partial) word.
905 */
906 if ((lastbit = len - i)) {
907 /*
908 * Mask of relevant bits.
909 */
910 mask = ((xfs_rtword_t)1 << lastbit) - 1;
911 /*
912 * Compute difference between actual and desired value.
913 */
914 if ((wdiff = (*b ^ val) & mask)) {
915 /*
916 * Different, compute first wrong bit and return.
917 */
918 xfs_trans_brelse(tp, bp);
919 i += XFS_RTLOBIT(wdiff);
920 *new = start + i;
921 *stat = 0;
922 return 0;
923 } else
924 i = len;
925 }
926 /*
927 * Successful, return.
928 */
929 xfs_trans_brelse(tp, bp);
930 *new = start + i;
931 *stat = 1;
932 return 0;
933 }
934
935 #ifdef DEBUG
936 /*
937 * Check that the given extent (block range) is allocated already.
938 */
939 STATIC int /* error */
940 xfs_rtcheck_alloc_range(
941 xfs_mount_t *mp, /* file system mount point */
942 xfs_trans_t *tp, /* transaction pointer */
943 xfs_rtblock_t bno, /* starting block number of extent */
944 xfs_extlen_t len) /* length of extent */
945 {
946 xfs_rtblock_t new; /* dummy for xfs_rtcheck_range */
947 int stat;
948 int error;
949
950 error = xfs_rtcheck_range(mp, tp, bno, len, 0, &new, &stat);
951 if (error)
952 return error;
953 ASSERT(stat);
954 return 0;
955 }
956 #else
957 #define xfs_rtcheck_alloc_range(m,t,b,l) (0)
958 #endif
959 /*
960 * Free an extent in the realtime subvolume. Length is expressed in
961 * realtime extents, as is the block number.
962 */
963 int /* error */
964 xfs_rtfree_extent(
965 xfs_trans_t *tp, /* transaction pointer */
966 xfs_rtblock_t bno, /* starting block number to free */
967 xfs_extlen_t len) /* length of extent freed */
968 {
969 int error; /* error value */
970 xfs_mount_t *mp; /* file system mount structure */
971 xfs_fsblock_t sb; /* summary file block number */
972 xfs_buf_t *sumbp = NULL; /* summary file block buffer */
973
974 mp = tp->t_mountp;
975
976 ASSERT(mp->m_rbmip->i_itemp != NULL);
977 ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
978
979 error = xfs_rtcheck_alloc_range(mp, tp, bno, len);
980 if (error)
981 return error;
982
983 /*
984 * Free the range of realtime blocks.
985 */
986 error = xfs_rtfree_range(mp, tp, bno, len, &sumbp, &sb);
987 if (error) {
988 return error;
989 }
990 /*
991 * Mark more blocks free in the superblock.
992 */
993 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, (long)len);
994 /*
995 * If we've now freed all the blocks, reset the file sequence
996 * number to 0.
997 */
998 if (tp->t_frextents_delta + mp->m_sb.sb_frextents ==
999 mp->m_sb.sb_rextents) {
1000 if (!(mp->m_rbmip->i_d.di_flags & XFS_DIFLAG_NEWRTBM))
1001 mp->m_rbmip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
1002 *(uint64_t *)&VFS_I(mp->m_rbmip)->i_atime = 0;
1003 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1004 }
1005 return 0;
1006 }
1007
1008 /* Find all the free records within a given range. */
1009 int
1010 xfs_rtalloc_query_range(
1011 struct xfs_trans *tp,
1012 struct xfs_rtalloc_rec *low_rec,
1013 struct xfs_rtalloc_rec *high_rec,
1014 xfs_rtalloc_query_range_fn fn,
1015 void *priv)
1016 {
1017 struct xfs_rtalloc_rec rec;
1018 struct xfs_mount *mp = tp->t_mountp;
1019 xfs_rtblock_t rtstart;
1020 xfs_rtblock_t rtend;
1021 xfs_rtblock_t rem;
1022 int is_free;
1023 int error = 0;
1024
1025 if (low_rec->ar_startext > high_rec->ar_startext)
1026 return -EINVAL;
1027 if (low_rec->ar_startext >= mp->m_sb.sb_rextents ||
1028 low_rec->ar_startext == high_rec->ar_startext)
1029 return 0;
1030 if (high_rec->ar_startext > mp->m_sb.sb_rextents)
1031 high_rec->ar_startext = mp->m_sb.sb_rextents;
1032
1033 /* Iterate the bitmap, looking for discrepancies. */
1034 rtstart = low_rec->ar_startext;
1035 rem = high_rec->ar_startext - rtstart;
1036 while (rem) {
1037 /* Is the first block free? */
1038 error = xfs_rtcheck_range(mp, tp, rtstart, 1, 1, &rtend,
1039 &is_free);
1040 if (error)
1041 break;
1042
1043 /* How long does the extent go for? */
1044 error = xfs_rtfind_forw(mp, tp, rtstart,
1045 high_rec->ar_startext - 1, &rtend);
1046 if (error)
1047 break;
1048
1049 if (is_free) {
1050 rec.ar_startext = rtstart;
1051 rec.ar_extcount = rtend - rtstart + 1;
1052
1053 error = fn(tp, &rec, priv);
1054 if (error)
1055 break;
1056 }
1057
1058 rem -= rtend - rtstart + 1;
1059 rtstart = rtend + 1;
1060 }
1061
1062 return error;
1063 }
1064
1065 /* Find all the free records. */
1066 int
1067 xfs_rtalloc_query_all(
1068 struct xfs_trans *tp,
1069 xfs_rtalloc_query_range_fn fn,
1070 void *priv)
1071 {
1072 struct xfs_rtalloc_rec keys[2];
1073
1074 keys[0].ar_startext = 0;
1075 keys[1].ar_startext = tp->t_mountp->m_sb.sb_rextents - 1;
1076 keys[0].ar_extcount = keys[1].ar_extcount = 0;
1077
1078 return xfs_rtalloc_query_range(tp, &keys[0], &keys[1], fn, priv);
1079 }
1080
1081 /* Is the given extent all free? */
1082 int
1083 xfs_rtalloc_extent_is_free(
1084 struct xfs_mount *mp,
1085 struct xfs_trans *tp,
1086 xfs_rtblock_t start,
1087 xfs_extlen_t len,
1088 bool *is_free)
1089 {
1090 xfs_rtblock_t end;
1091 int matches;
1092 int error;
1093
1094 error = xfs_rtcheck_range(mp, tp, start, len, 1, &end, &matches);
1095 if (error)
1096 return error;
1097
1098 *is_free = matches;
1099 return 0;
1100 }