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TOMOYO Linux Cross Reference
Linux/fs/xfs/xfs_rtalloc.c

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  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_alloc.h"
 16 #include "xfs_bmap.h"
 17 #include "xfs_bmap_btree.h"
 18 #include "xfs_bmap_util.h"
 19 #include "xfs_trans.h"
 20 #include "xfs_trans_space.h"
 21 #include "xfs_icache.h"
 22 #include "xfs_rtalloc.h"
 23 #include "xfs_sb.h"
 24 #include "xfs_rtbitmap.h"
 25 #include "xfs_quota.h"
 26 #include "xfs_log_priv.h"
 27 #include "xfs_health.h"
 28 
 29 /*
 30  * Return whether there are any free extents in the size range given
 31  * by low and high, for the bitmap block bbno.
 32  */
 33 STATIC int
 34 xfs_rtany_summary(
 35         struct xfs_rtalloc_args *args,
 36         int                     low,    /* low log2 extent size */
 37         int                     high,   /* high log2 extent size */
 38         xfs_fileoff_t           bbno,   /* bitmap block number */
 39         int                     *maxlog) /* out: max log2 extent size free */
 40 {
 41         struct xfs_mount        *mp = args->mp;
 42         int                     error;
 43         int                     log;    /* loop counter, log2 of ext. size */
 44         xfs_suminfo_t           sum;    /* summary data */
 45 
 46         /* There are no extents at levels >= m_rsum_cache[bbno]. */
 47         if (mp->m_rsum_cache) {
 48                 high = min(high, mp->m_rsum_cache[bbno] - 1);
 49                 if (low > high) {
 50                         *maxlog = -1;
 51                         return 0;
 52                 }
 53         }
 54 
 55         /*
 56          * Loop over logs of extent sizes.
 57          */
 58         for (log = high; log >= low; log--) {
 59                 /*
 60                  * Get one summary datum.
 61                  */
 62                 error = xfs_rtget_summary(args, log, bbno, &sum);
 63                 if (error) {
 64                         return error;
 65                 }
 66                 /*
 67                  * If there are any, return success.
 68                  */
 69                 if (sum) {
 70                         *maxlog = log;
 71                         goto out;
 72                 }
 73         }
 74         /*
 75          * Found nothing, return failure.
 76          */
 77         *maxlog = -1;
 78 out:
 79         /* There were no extents at levels > log. */
 80         if (mp->m_rsum_cache && log + 1 < mp->m_rsum_cache[bbno])
 81                 mp->m_rsum_cache[bbno] = log + 1;
 82         return 0;
 83 }
 84 
 85 
 86 /*
 87  * Copy and transform the summary file, given the old and new
 88  * parameters in the mount structures.
 89  */
 90 STATIC int
 91 xfs_rtcopy_summary(
 92         struct xfs_rtalloc_args *oargs,
 93         struct xfs_rtalloc_args *nargs)
 94 {
 95         xfs_fileoff_t           bbno;   /* bitmap block number */
 96         int                     error;
 97         int                     log;    /* summary level number (log length) */
 98         xfs_suminfo_t           sum;    /* summary data */
 99 
100         for (log = oargs->mp->m_rsumlevels - 1; log >= 0; log--) {
101                 for (bbno = oargs->mp->m_sb.sb_rbmblocks - 1;
102                      (xfs_srtblock_t)bbno >= 0;
103                      bbno--) {
104                         error = xfs_rtget_summary(oargs, log, bbno, &sum);
105                         if (error)
106                                 goto out;
107                         if (sum == 0)
108                                 continue;
109                         error = xfs_rtmodify_summary(oargs, log, bbno, -sum);
110                         if (error)
111                                 goto out;
112                         error = xfs_rtmodify_summary(nargs, log, bbno, sum);
113                         if (error)
114                                 goto out;
115                         ASSERT(sum > 0);
116                 }
117         }
118         error = 0;
119 out:
120         xfs_rtbuf_cache_relse(oargs);
121         return 0;
122 }
123 /*
124  * Mark an extent specified by start and len allocated.
125  * Updates all the summary information as well as the bitmap.
126  */
127 STATIC int
128 xfs_rtallocate_range(
129         struct xfs_rtalloc_args *args,
130         xfs_rtxnum_t            start,  /* start rtext to allocate */
131         xfs_rtxlen_t            len)    /* in/out: summary block number */
132 {
133         struct xfs_mount        *mp = args->mp;
134         xfs_rtxnum_t            end;    /* end of the allocated rtext */
135         int                     error;
136         xfs_rtxnum_t            postblock = 0; /* first rtext allocated > end */
137         xfs_rtxnum_t            preblock = 0; /* first rtext allocated < start */
138 
139         end = start + len - 1;
140         /*
141          * Assume we're allocating out of the middle of a free extent.
142          * We need to find the beginning and end of the extent so we can
143          * properly update the summary.
144          */
145         error = xfs_rtfind_back(args, start, 0, &preblock);
146         if (error)
147                 return error;
148 
149         /*
150          * Find the next allocated block (end of free extent).
151          */
152         error = xfs_rtfind_forw(args, end, mp->m_sb.sb_rextents - 1,
153                         &postblock);
154         if (error)
155                 return error;
156 
157         /*
158          * Decrement the summary information corresponding to the entire
159          * (old) free extent.
160          */
161         error = xfs_rtmodify_summary(args,
162                         xfs_highbit64(postblock + 1 - preblock),
163                         xfs_rtx_to_rbmblock(mp, preblock), -1);
164         if (error)
165                 return error;
166 
167         /*
168          * If there are blocks not being allocated at the front of the
169          * old extent, add summary data for them to be free.
170          */
171         if (preblock < start) {
172                 error = xfs_rtmodify_summary(args,
173                                 xfs_highbit64(start - preblock),
174                                 xfs_rtx_to_rbmblock(mp, preblock), 1);
175                 if (error)
176                         return error;
177         }
178 
179         /*
180          * If there are blocks not being allocated at the end of the
181          * old extent, add summary data for them to be free.
182          */
183         if (postblock > end) {
184                 error = xfs_rtmodify_summary(args,
185                                 xfs_highbit64(postblock - end),
186                                 xfs_rtx_to_rbmblock(mp, end + 1), 1);
187                 if (error)
188                         return error;
189         }
190 
191         /*
192          * Modify the bitmap to mark this extent allocated.
193          */
194         return xfs_rtmodify_range(args, start, len, 0);
195 }
196 
197 /*
198  * Make sure we don't run off the end of the rt volume.  Be careful that
199  * adjusting maxlen downwards doesn't cause us to fail the alignment checks.
200  */
201 static inline xfs_rtxlen_t
202 xfs_rtallocate_clamp_len(
203         struct xfs_mount        *mp,
204         xfs_rtxnum_t            startrtx,
205         xfs_rtxlen_t            rtxlen,
206         xfs_rtxlen_t            prod)
207 {
208         xfs_rtxlen_t            ret;
209 
210         ret = min(mp->m_sb.sb_rextents, startrtx + rtxlen) - startrtx;
211         return rounddown(ret, prod);
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 *rtx.
218  * The lengths are all in rtextents.
219  */
220 STATIC int
221 xfs_rtallocate_extent_block(
222         struct xfs_rtalloc_args *args,
223         xfs_fileoff_t           bbno,   /* bitmap block number */
224         xfs_rtxlen_t            minlen, /* minimum length to allocate */
225         xfs_rtxlen_t            maxlen, /* maximum length to allocate */
226         xfs_rtxlen_t            *len,   /* out: actual length allocated */
227         xfs_rtxnum_t            *nextp, /* out: next rtext to try */
228         xfs_rtxlen_t            prod,   /* extent product factor */
229         xfs_rtxnum_t            *rtx)   /* out: start rtext allocated */
230 {
231         struct xfs_mount        *mp = args->mp;
232         xfs_rtxnum_t            besti;  /* best rtext found so far */
233         xfs_rtxnum_t            bestlen;/* best length found so far */
234         xfs_rtxnum_t            end;    /* last rtext in chunk */
235         int                     error;
236         xfs_rtxnum_t            i;      /* current rtext trying */
237         xfs_rtxnum_t            next;   /* next rtext to try */
238         int                     stat;   /* status from internal calls */
239 
240         /*
241          * Loop over all the extents starting in this bitmap block,
242          * looking for one that's long enough.
243          */
244         for (i = xfs_rbmblock_to_rtx(mp, bbno), besti = -1, bestlen = 0,
245                 end = xfs_rbmblock_to_rtx(mp, bbno + 1) - 1;
246              i <= end;
247              i++) {
248                 /* Make sure we don't scan off the end of the rt volume. */
249                 maxlen = xfs_rtallocate_clamp_len(mp, i, maxlen, prod);
250 
251                 /*
252                  * See if there's a free extent of maxlen starting at i.
253                  * If it's not so then next will contain the first non-free.
254                  */
255                 error = xfs_rtcheck_range(args, i, maxlen, 1, &next, &stat);
256                 if (error)
257                         return error;
258                 if (stat) {
259                         /*
260                          * i for maxlen is all free, allocate and return that.
261                          */
262                         bestlen = maxlen;
263                         besti = i;
264                         goto allocate;
265                 }
266 
267                 /*
268                  * In the case where we have a variable-sized allocation
269                  * request, figure out how big this free piece is,
270                  * and if it's big enough for the minimum, and the best
271                  * so far, remember it.
272                  */
273                 if (minlen < maxlen) {
274                         xfs_rtxnum_t    thislen;        /* this extent size */
275 
276                         thislen = next - i;
277                         if (thislen >= minlen && thislen > bestlen) {
278                                 besti = i;
279                                 bestlen = thislen;
280                         }
281                 }
282                 /*
283                  * If not done yet, find the start of the next free space.
284                  */
285                 if (next >= end)
286                         break;
287                 error = xfs_rtfind_forw(args, next, end, &i);
288                 if (error)
289                         return error;
290         }
291 
292         /*
293          * Searched the whole thing & didn't find a maxlen free extent.
294          */
295         if (minlen > maxlen || besti == -1) {
296                 /*
297                  * Allocation failed.  Set *nextp to the next block to try.
298                  */
299                 *nextp = next;
300                 return -ENOSPC;
301         }
302 
303         /*
304          * If size should be a multiple of prod, make that so.
305          */
306         if (prod > 1) {
307                 xfs_rtxlen_t    p;      /* amount to trim length by */
308 
309                 div_u64_rem(bestlen, prod, &p);
310                 if (p)
311                         bestlen -= p;
312         }
313 
314         /*
315          * Allocate besti for bestlen & return that.
316          */
317 allocate:
318         error = xfs_rtallocate_range(args, besti, bestlen);
319         if (error)
320                 return error;
321         *len = bestlen;
322         *rtx = besti;
323         return 0;
324 }
325 
326 /*
327  * Allocate an extent of length minlen<=len<=maxlen, starting at block
328  * bno.  If we don't get maxlen then use prod to trim the length, if given.
329  * Returns error; returns starting block in *rtx.
330  * The lengths are all in rtextents.
331  */
332 STATIC int
333 xfs_rtallocate_extent_exact(
334         struct xfs_rtalloc_args *args,
335         xfs_rtxnum_t            start,  /* starting rtext number to allocate */
336         xfs_rtxlen_t            minlen, /* minimum length to allocate */
337         xfs_rtxlen_t            maxlen, /* maximum length to allocate */
338         xfs_rtxlen_t            *len,   /* out: actual length allocated */
339         xfs_rtxlen_t            prod,   /* extent product factor */
340         xfs_rtxnum_t            *rtx)   /* out: start rtext allocated */
341 {
342         int                     error;
343         xfs_rtxlen_t            i;      /* extent length trimmed due to prod */
344         int                     isfree; /* extent is free */
345         xfs_rtxnum_t            next;   /* next rtext to try (dummy) */
346 
347         ASSERT(minlen % prod == 0);
348         ASSERT(maxlen % prod == 0);
349         /*
350          * Check if the range in question (for maxlen) is free.
351          */
352         error = xfs_rtcheck_range(args, start, maxlen, 1, &next, &isfree);
353         if (error)
354                 return error;
355 
356         if (!isfree) {
357                 /*
358                  * If not, allocate what there is, if it's at least minlen.
359                  */
360                 maxlen = next - start;
361                 if (maxlen < minlen)
362                         return -ENOSPC;
363 
364                 /*
365                  * Trim off tail of extent, if prod is specified.
366                  */
367                 if (prod > 1 && (i = maxlen % prod)) {
368                         maxlen -= i;
369                         if (maxlen < minlen)
370                                 return -ENOSPC;
371                 }
372         }
373 
374         /*
375          * Allocate what we can and return it.
376          */
377         error = xfs_rtallocate_range(args, start, maxlen);
378         if (error)
379                 return error;
380         *len = maxlen;
381         *rtx = start;
382         return 0;
383 }
384 
385 /*
386  * Allocate an extent of length minlen<=len<=maxlen, starting as near
387  * to start as possible.  If we don't get maxlen then use prod to trim
388  * the length, if given.  The lengths are all in rtextents.
389  */
390 STATIC int
391 xfs_rtallocate_extent_near(
392         struct xfs_rtalloc_args *args,
393         xfs_rtxnum_t            start,  /* starting rtext number to allocate */
394         xfs_rtxlen_t            minlen, /* minimum length to allocate */
395         xfs_rtxlen_t            maxlen, /* maximum length to allocate */
396         xfs_rtxlen_t            *len,   /* out: actual length allocated */
397         xfs_rtxlen_t            prod,   /* extent product factor */
398         xfs_rtxnum_t            *rtx)   /* out: start rtext allocated */
399 {
400         struct xfs_mount        *mp = args->mp;
401         int                     maxlog; /* max useful extent from summary */
402         xfs_fileoff_t           bbno;   /* bitmap block number */
403         int                     error;
404         int                     i;      /* bitmap block offset (loop control) */
405         int                     j;      /* secondary loop control */
406         int                     log2len; /* log2 of minlen */
407         xfs_rtxnum_t            n;      /* next rtext to try */
408 
409         ASSERT(minlen % prod == 0);
410         ASSERT(maxlen % prod == 0);
411 
412         /*
413          * If the block number given is off the end, silently set it to
414          * the last block.
415          */
416         if (start >= mp->m_sb.sb_rextents)
417                 start = mp->m_sb.sb_rextents - 1;
418 
419         /* Make sure we don't run off the end of the rt volume. */
420         maxlen = xfs_rtallocate_clamp_len(mp, start, maxlen, prod);
421         if (maxlen < minlen)
422                 return -ENOSPC;
423 
424         /*
425          * Try the exact allocation first.
426          */
427         error = xfs_rtallocate_extent_exact(args, start, minlen, maxlen, len,
428                         prod, rtx);
429         if (error != -ENOSPC)
430                 return error;
431 
432 
433         bbno = xfs_rtx_to_rbmblock(mp, start);
434         i = 0;
435         j = -1;
436         ASSERT(minlen != 0);
437         log2len = xfs_highbit32(minlen);
438         /*
439          * Loop over all bitmap blocks (bbno + i is current block).
440          */
441         for (;;) {
442                 /*
443                  * Get summary information of extents of all useful levels
444                  * starting in this bitmap block.
445                  */
446                 error = xfs_rtany_summary(args, log2len, mp->m_rsumlevels - 1,
447                                 bbno + i, &maxlog);
448                 if (error)
449                         return error;
450 
451                 /*
452                  * If there are any useful extents starting here, try
453                  * allocating one.
454                  */
455                 if (maxlog >= 0) {
456                         xfs_extlen_t maxavail =
457                                 min_t(xfs_rtblock_t, maxlen,
458                                       (1ULL << (maxlog + 1)) - 1);
459                         /*
460                          * On the positive side of the starting location.
461                          */
462                         if (i >= 0) {
463                                 /*
464                                  * Try to allocate an extent starting in
465                                  * this block.
466                                  */
467                                 error = xfs_rtallocate_extent_block(args,
468                                                 bbno + i, minlen, maxavail, len,
469                                                 &n, prod, rtx);
470                                 if (error != -ENOSPC)
471                                         return error;
472                         }
473                         /*
474                          * On the negative side of the starting location.
475                          */
476                         else {          /* i < 0 */
477                                 int     maxblocks;
478 
479                                 /*
480                                  * Loop backwards to find the end of the extent
481                                  * we found in the realtime summary.
482                                  *
483                                  * maxblocks is the maximum possible number of
484                                  * bitmap blocks from the start of the extent
485                                  * to the end of the extent.
486                                  */
487                                 if (maxlog == 0)
488                                         maxblocks = 0;
489                                 else if (maxlog < mp->m_blkbit_log)
490                                         maxblocks = 1;
491                                 else
492                                         maxblocks = 2 << (maxlog - mp->m_blkbit_log);
493 
494                                 /*
495                                  * We need to check bbno + i + maxblocks down to
496                                  * bbno + i. We already checked bbno down to
497                                  * bbno + j + 1, so we don't need to check those
498                                  * again.
499                                  */
500                                 j = min(i + maxblocks, j);
501                                 for (; j >= i; j--) {
502                                         error = xfs_rtallocate_extent_block(args,
503                                                         bbno + j, minlen,
504                                                         maxavail, len, &n, prod,
505                                                         rtx);
506                                         if (error != -ENOSPC)
507                                                 return error;
508                                 }
509                         }
510                 }
511                 /*
512                  * Loop control.  If we were on the positive side, and there's
513                  * still more blocks on the negative side, go there.
514                  */
515                 if (i > 0 && (int)bbno - i >= 0)
516                         i = -i;
517                 /*
518                  * If positive, and no more negative, but there are more
519                  * positive, go there.
520                  */
521                 else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
522                         i++;
523                 /*
524                  * If negative or 0 (just started), and there are positive
525                  * blocks to go, go there.  The 0 case moves to block 1.
526                  */
527                 else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
528                         i = 1 - i;
529                 /*
530                  * If negative or 0 and there are more negative blocks,
531                  * go there.
532                  */
533                 else if (i <= 0 && (int)bbno + i > 0)
534                         i--;
535                 /*
536                  * Must be done.  Return failure.
537                  */
538                 else
539                         break;
540         }
541         return -ENOSPC;
542 }
543 
544 static int
545 xfs_rtalloc_sumlevel(
546         struct xfs_rtalloc_args *args,
547         int                     l,      /* level number */
548         xfs_rtxlen_t            minlen, /* minimum length to allocate */
549         xfs_rtxlen_t            maxlen, /* maximum length to allocate */
550         xfs_rtxlen_t            prod,   /* extent product factor */
551         xfs_rtxlen_t            *len,   /* out: actual length allocated */
552         xfs_rtxnum_t            *rtx)   /* out: start rtext allocated */
553 {
554         xfs_fileoff_t           i;      /* bitmap block number */
555 
556         for (i = 0; i < args->mp->m_sb.sb_rbmblocks; i++) {
557                 xfs_suminfo_t   sum;    /* summary information for extents */
558                 xfs_rtxnum_t    n;      /* next rtext to be tried */
559                 int             error;
560 
561                 error = xfs_rtget_summary(args, l, i, &sum);
562                 if (error)
563                         return error;
564 
565                 /*
566                  * Nothing there, on to the next block.
567                  */
568                 if (!sum)
569                         continue;
570 
571                 /*
572                  * Try allocating the extent.
573                  */
574                 error = xfs_rtallocate_extent_block(args, i, minlen, maxlen,
575                                 len, &n, prod, rtx);
576                 if (error != -ENOSPC)
577                         return error;
578 
579                 /*
580                  * If the "next block to try" returned from the allocator is
581                  * beyond the next bitmap block, skip to that bitmap block.
582                  */
583                 if (xfs_rtx_to_rbmblock(args->mp, n) > i + 1)
584                         i = xfs_rtx_to_rbmblock(args->mp, n) - 1;
585         }
586 
587         return -ENOSPC;
588 }
589 
590 /*
591  * Allocate an extent of length minlen<=len<=maxlen, with no position
592  * specified.  If we don't get maxlen then use prod to trim
593  * the length, if given.  The lengths are all in rtextents.
594  */
595 STATIC int
596 xfs_rtallocate_extent_size(
597         struct xfs_rtalloc_args *args,
598         xfs_rtxlen_t            minlen, /* minimum length to allocate */
599         xfs_rtxlen_t            maxlen, /* maximum length to allocate */
600         xfs_rtxlen_t            *len,   /* out: actual length allocated */
601         xfs_rtxlen_t            prod,   /* extent product factor */
602         xfs_rtxnum_t            *rtx)   /* out: start rtext allocated */
603 {
604         int                     error;
605         int                     l;      /* level number (loop control) */
606 
607         ASSERT(minlen % prod == 0);
608         ASSERT(maxlen % prod == 0);
609         ASSERT(maxlen != 0);
610 
611         /*
612          * Loop over all the levels starting with maxlen.
613          *
614          * At each level, look at all the bitmap blocks, to see if there are
615          * extents starting there that are long enough (>= maxlen).
616          *
617          * Note, only on the initial level can the allocation fail if the
618          * summary says there's an extent.
619          */
620         for (l = xfs_highbit32(maxlen); l < args->mp->m_rsumlevels; l++) {
621                 error = xfs_rtalloc_sumlevel(args, l, minlen, maxlen, prod, len,
622                                 rtx);
623                 if (error != -ENOSPC)
624                         return error;
625         }
626 
627         /*
628          * Didn't find any maxlen blocks.  Try smaller ones, unless we are
629          * looking for a fixed size extent.
630          */
631         if (minlen > --maxlen)
632                 return -ENOSPC;
633         ASSERT(minlen != 0);
634         ASSERT(maxlen != 0);
635 
636         /*
637          * Loop over sizes, from maxlen down to minlen.
638          *
639          * This time, when we do the allocations, allow smaller ones to succeed,
640          * but make sure the specified minlen/maxlen are in the possible range
641          * for this summary level.
642          */
643         for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
644                 error = xfs_rtalloc_sumlevel(args, l,
645                                 max_t(xfs_rtxlen_t, minlen, 1 << l),
646                                 min_t(xfs_rtxlen_t, maxlen, (1 << (l + 1)) - 1),
647                                 prod, len, rtx);
648                 if (error != -ENOSPC)
649                         return error;
650         }
651 
652         return -ENOSPC;
653 }
654 
655 /*
656  * Allocate space to the bitmap or summary file, and zero it, for growfs.
657  */
658 STATIC int
659 xfs_growfs_rt_alloc(
660         struct xfs_mount        *mp,            /* file system mount point */
661         xfs_extlen_t            oblocks,        /* old count of blocks */
662         xfs_extlen_t            nblocks,        /* new count of blocks */
663         struct xfs_inode        *ip)            /* inode (bitmap/summary) */
664 {
665         xfs_fileoff_t           bno;            /* block number in file */
666         struct xfs_buf          *bp;    /* temporary buffer for zeroing */
667         xfs_daddr_t             d;              /* disk block address */
668         int                     error;          /* error return value */
669         xfs_fsblock_t           fsbno;          /* filesystem block for bno */
670         struct xfs_bmbt_irec    map;            /* block map output */
671         int                     nmap;           /* number of block maps */
672         int                     resblks;        /* space reservation */
673         enum xfs_blft           buf_type;
674         struct xfs_trans        *tp;
675 
676         if (ip == mp->m_rsumip)
677                 buf_type = XFS_BLFT_RTSUMMARY_BUF;
678         else
679                 buf_type = XFS_BLFT_RTBITMAP_BUF;
680 
681         /*
682          * Allocate space to the file, as necessary.
683          */
684         while (oblocks < nblocks) {
685                 resblks = XFS_GROWFSRT_SPACE_RES(mp, nblocks - oblocks);
686                 /*
687                  * Reserve space & log for one extent added to the file.
688                  */
689                 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtalloc, resblks,
690                                 0, 0, &tp);
691                 if (error)
692                         return error;
693                 /*
694                  * Lock the inode.
695                  */
696                 xfs_ilock(ip, XFS_ILOCK_EXCL);
697                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
698 
699                 error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
700                                 XFS_IEXT_ADD_NOSPLIT_CNT);
701                 if (error)
702                         goto out_trans_cancel;
703 
704                 /*
705                  * Allocate blocks to the bitmap file.
706                  */
707                 nmap = 1;
708                 error = xfs_bmapi_write(tp, ip, oblocks, nblocks - oblocks,
709                                         XFS_BMAPI_METADATA, 0, &map, &nmap);
710                 if (error)
711                         goto out_trans_cancel;
712                 /*
713                  * Free any blocks freed up in the transaction, then commit.
714                  */
715                 error = xfs_trans_commit(tp);
716                 if (error)
717                         return error;
718                 /*
719                  * Now we need to clear the allocated blocks.
720                  * Do this one block per transaction, to keep it simple.
721                  */
722                 for (bno = map.br_startoff, fsbno = map.br_startblock;
723                      bno < map.br_startoff + map.br_blockcount;
724                      bno++, fsbno++) {
725                         /*
726                          * Reserve log for one block zeroing.
727                          */
728                         error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtzero,
729                                         0, 0, 0, &tp);
730                         if (error)
731                                 return error;
732                         /*
733                          * Lock the bitmap inode.
734                          */
735                         xfs_ilock(ip, XFS_ILOCK_EXCL);
736                         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
737                         /*
738                          * Get a buffer for the block.
739                          */
740                         d = XFS_FSB_TO_DADDR(mp, fsbno);
741                         error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
742                                         mp->m_bsize, 0, &bp);
743                         if (error)
744                                 goto out_trans_cancel;
745 
746                         xfs_trans_buf_set_type(tp, bp, buf_type);
747                         bp->b_ops = &xfs_rtbuf_ops;
748                         memset(bp->b_addr, 0, mp->m_sb.sb_blocksize);
749                         xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
750                         /*
751                          * Commit the transaction.
752                          */
753                         error = xfs_trans_commit(tp);
754                         if (error)
755                                 return error;
756                 }
757                 /*
758                  * Go on to the next extent, if any.
759                  */
760                 oblocks = map.br_startoff + map.br_blockcount;
761         }
762 
763         return 0;
764 
765 out_trans_cancel:
766         xfs_trans_cancel(tp);
767         return error;
768 }
769 
770 static void
771 xfs_alloc_rsum_cache(
772         xfs_mount_t     *mp,            /* file system mount structure */
773         xfs_extlen_t    rbmblocks)      /* number of rt bitmap blocks */
774 {
775         /*
776          * The rsum cache is initialized to the maximum value, which is
777          * trivially an upper bound on the maximum level with any free extents.
778          * We can continue without the cache if it couldn't be allocated.
779          */
780         mp->m_rsum_cache = kvmalloc(rbmblocks, GFP_KERNEL);
781         if (mp->m_rsum_cache)
782                 memset(mp->m_rsum_cache, -1, rbmblocks);
783         else
784                 xfs_warn(mp, "could not allocate realtime summary cache");
785 }
786 
787 /*
788  * If we changed the rt extent size (meaning there was no rt volume previously)
789  * and the root directory had EXTSZINHERIT and RTINHERIT set, it's possible
790  * that the extent size hint on the root directory is no longer congruent with
791  * the new rt extent size.  Log the rootdir inode to fix this.
792  */
793 static int
794 xfs_growfs_rt_fixup_extsize(
795         struct xfs_mount        *mp)
796 {
797         struct xfs_inode        *ip = mp->m_rootip;
798         struct xfs_trans        *tp;
799         int                     error = 0;
800 
801         xfs_ilock(ip, XFS_IOLOCK_EXCL);
802         if (!(ip->i_diflags & XFS_DIFLAG_RTINHERIT) ||
803             !(ip->i_diflags & XFS_DIFLAG_EXTSZINHERIT))
804                 goto out_iolock;
805 
806         error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_ichange, 0, 0, false,
807                         &tp);
808         if (error)
809                 goto out_iolock;
810 
811         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
812         error = xfs_trans_commit(tp);
813         xfs_iunlock(ip, XFS_ILOCK_EXCL);
814 
815 out_iolock:
816         xfs_iunlock(ip, XFS_IOLOCK_EXCL);
817         return error;
818 }
819 
820 /*
821  * Visible (exported) functions.
822  */
823 
824 /*
825  * Grow the realtime area of the filesystem.
826  */
827 int
828 xfs_growfs_rt(
829         xfs_mount_t     *mp,            /* mount point for filesystem */
830         xfs_growfs_rt_t *in)            /* growfs rt input struct */
831 {
832         xfs_fileoff_t   bmbno;          /* bitmap block number */
833         struct xfs_buf  *bp;            /* temporary buffer */
834         int             error;          /* error return value */
835         xfs_mount_t     *nmp;           /* new (fake) mount structure */
836         xfs_rfsblock_t  nrblocks;       /* new number of realtime blocks */
837         xfs_extlen_t    nrbmblocks;     /* new number of rt bitmap blocks */
838         xfs_rtxnum_t    nrextents;      /* new number of realtime extents */
839         uint8_t         nrextslog;      /* new log2 of sb_rextents */
840         xfs_extlen_t    nrsumblocks;    /* new number of summary blocks */
841         uint            nrsumlevels;    /* new rt summary levels */
842         uint            nrsumsize;      /* new size of rt summary, bytes */
843         xfs_sb_t        *nsbp;          /* new superblock */
844         xfs_extlen_t    rbmblocks;      /* current number of rt bitmap blocks */
845         xfs_extlen_t    rsumblocks;     /* current number of rt summary blks */
846         xfs_sb_t        *sbp;           /* old superblock */
847         uint8_t         *rsum_cache;    /* old summary cache */
848         xfs_agblock_t   old_rextsize = mp->m_sb.sb_rextsize;
849 
850         sbp = &mp->m_sb;
851 
852         if (!capable(CAP_SYS_ADMIN))
853                 return -EPERM;
854 
855         /* Needs to have been mounted with an rt device. */
856         if (!XFS_IS_REALTIME_MOUNT(mp))
857                 return -EINVAL;
858 
859         if (!mutex_trylock(&mp->m_growlock))
860                 return -EWOULDBLOCK;
861         /*
862          * Mount should fail if the rt bitmap/summary files don't load, but
863          * we'll check anyway.
864          */
865         error = -EINVAL;
866         if (!mp->m_rbmip || !mp->m_rsumip)
867                 goto out_unlock;
868 
869         /* Shrink not supported. */
870         if (in->newblocks <= sbp->sb_rblocks)
871                 goto out_unlock;
872 
873         /* Can only change rt extent size when adding rt volume. */
874         if (sbp->sb_rblocks > 0 && in->extsize != sbp->sb_rextsize)
875                 goto out_unlock;
876 
877         /* Range check the extent size. */
878         if (XFS_FSB_TO_B(mp, in->extsize) > XFS_MAX_RTEXTSIZE ||
879             XFS_FSB_TO_B(mp, in->extsize) < XFS_MIN_RTEXTSIZE)
880                 goto out_unlock;
881 
882         /* Unsupported realtime features. */
883         error = -EOPNOTSUPP;
884         if (xfs_has_rmapbt(mp) || xfs_has_reflink(mp) || xfs_has_quota(mp))
885                 goto out_unlock;
886 
887         nrblocks = in->newblocks;
888         error = xfs_sb_validate_fsb_count(sbp, nrblocks);
889         if (error)
890                 goto out_unlock;
891         /*
892          * Read in the last block of the device, make sure it exists.
893          */
894         error = xfs_buf_read_uncached(mp->m_rtdev_targp,
895                                 XFS_FSB_TO_BB(mp, nrblocks - 1),
896                                 XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
897         if (error)
898                 goto out_unlock;
899         xfs_buf_relse(bp);
900 
901         /*
902          * Calculate new parameters.  These are the final values to be reached.
903          */
904         nrextents = nrblocks;
905         do_div(nrextents, in->extsize);
906         if (!xfs_validate_rtextents(nrextents)) {
907                 error = -EINVAL;
908                 goto out_unlock;
909         }
910         nrbmblocks = xfs_rtbitmap_blockcount(mp, nrextents);
911         nrextslog = xfs_compute_rextslog(nrextents);
912         nrsumlevels = nrextslog + 1;
913         nrsumblocks = xfs_rtsummary_blockcount(mp, nrsumlevels, nrbmblocks);
914         nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
915         /*
916          * New summary size can't be more than half the size of
917          * the log.  This prevents us from getting a log overflow,
918          * since we'll log basically the whole summary file at once.
919          */
920         if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1)) {
921                 error = -EINVAL;
922                 goto out_unlock;
923         }
924 
925         /*
926          * Get the old block counts for bitmap and summary inodes.
927          * These can't change since other growfs callers are locked out.
928          */
929         rbmblocks = XFS_B_TO_FSB(mp, mp->m_rbmip->i_disk_size);
930         rsumblocks = XFS_B_TO_FSB(mp, mp->m_rsumip->i_disk_size);
931         /*
932          * Allocate space to the bitmap and summary files, as necessary.
933          */
934         error = xfs_growfs_rt_alloc(mp, rbmblocks, nrbmblocks, mp->m_rbmip);
935         if (error)
936                 goto out_unlock;
937         error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip);
938         if (error)
939                 goto out_unlock;
940 
941         rsum_cache = mp->m_rsum_cache;
942         if (nrbmblocks != sbp->sb_rbmblocks)
943                 xfs_alloc_rsum_cache(mp, nrbmblocks);
944 
945         /*
946          * Allocate a new (fake) mount/sb.
947          */
948         nmp = kmalloc(sizeof(*nmp), GFP_KERNEL | __GFP_NOFAIL);
949         /*
950          * Loop over the bitmap blocks.
951          * We will do everything one bitmap block at a time.
952          * Skip the current block if it is exactly full.
953          * This also deals with the case where there were no rtextents before.
954          */
955         for (bmbno = sbp->sb_rbmblocks -
956                      ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
957              bmbno < nrbmblocks;
958              bmbno++) {
959                 struct xfs_rtalloc_args args = {
960                         .mp             = mp,
961                 };
962                 struct xfs_rtalloc_args nargs = {
963                         .mp             = nmp,
964                 };
965                 struct xfs_trans        *tp;
966                 xfs_rfsblock_t          nrblocks_step;
967 
968                 *nmp = *mp;
969                 nsbp = &nmp->m_sb;
970                 /*
971                  * Calculate new sb and mount fields for this round.
972                  */
973                 nsbp->sb_rextsize = in->extsize;
974                 nmp->m_rtxblklog = -1; /* don't use shift or masking */
975                 nsbp->sb_rbmblocks = bmbno + 1;
976                 nrblocks_step = (bmbno + 1) * NBBY * nsbp->sb_blocksize *
977                                 nsbp->sb_rextsize;
978                 nsbp->sb_rblocks = min(nrblocks, nrblocks_step);
979                 nsbp->sb_rextents = xfs_rtb_to_rtx(nmp, nsbp->sb_rblocks);
980                 ASSERT(nsbp->sb_rextents != 0);
981                 nsbp->sb_rextslog = xfs_compute_rextslog(nsbp->sb_rextents);
982                 nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
983                 nrsumblocks = xfs_rtsummary_blockcount(mp, nrsumlevels,
984                                 nsbp->sb_rbmblocks);
985                 nmp->m_rsumsize = nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
986                 /* recompute growfsrt reservation from new rsumsize */
987                 xfs_trans_resv_calc(nmp, &nmp->m_resv);
988 
989                 /*
990                  * Start a transaction, get the log reservation.
991                  */
992                 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growrtfree, 0, 0, 0,
993                                 &tp);
994                 if (error)
995                         break;
996                 args.tp = tp;
997                 nargs.tp = tp;
998 
999                 /*
1000                  * Lock out other callers by grabbing the bitmap and summary
1001                  * inode locks and joining them to the transaction.
1002                  */
1003                 xfs_rtbitmap_lock(tp, mp);
1004                 /*
1005                  * Update the bitmap inode's size ondisk and incore.  We need
1006                  * to update the incore size so that inode inactivation won't
1007                  * punch what it thinks are "posteof" blocks.
1008                  */
1009                 mp->m_rbmip->i_disk_size =
1010                         nsbp->sb_rbmblocks * nsbp->sb_blocksize;
1011                 i_size_write(VFS_I(mp->m_rbmip), mp->m_rbmip->i_disk_size);
1012                 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1013                 /*
1014                  * Update the summary inode's size.  We need to update the
1015                  * incore size so that inode inactivation won't punch what it
1016                  * thinks are "posteof" blocks.
1017                  */
1018                 mp->m_rsumip->i_disk_size = nmp->m_rsumsize;
1019                 i_size_write(VFS_I(mp->m_rsumip), mp->m_rsumip->i_disk_size);
1020                 xfs_trans_log_inode(tp, mp->m_rsumip, XFS_ILOG_CORE);
1021                 /*
1022                  * Copy summary data from old to new sizes.
1023                  * Do this when the real size (not block-aligned) changes.
1024                  */
1025                 if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
1026                     mp->m_rsumlevels != nmp->m_rsumlevels) {
1027                         error = xfs_rtcopy_summary(&args, &nargs);
1028                         if (error)
1029                                 goto error_cancel;
1030                 }
1031                 /*
1032                  * Update superblock fields.
1033                  */
1034                 if (nsbp->sb_rextsize != sbp->sb_rextsize)
1035                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
1036                                 nsbp->sb_rextsize - sbp->sb_rextsize);
1037                 if (nsbp->sb_rbmblocks != sbp->sb_rbmblocks)
1038                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
1039                                 nsbp->sb_rbmblocks - sbp->sb_rbmblocks);
1040                 if (nsbp->sb_rblocks != sbp->sb_rblocks)
1041                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
1042                                 nsbp->sb_rblocks - sbp->sb_rblocks);
1043                 if (nsbp->sb_rextents != sbp->sb_rextents)
1044                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
1045                                 nsbp->sb_rextents - sbp->sb_rextents);
1046                 if (nsbp->sb_rextslog != sbp->sb_rextslog)
1047                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
1048                                 nsbp->sb_rextslog - sbp->sb_rextslog);
1049                 /*
1050                  * Free new extent.
1051                  */
1052                 error = xfs_rtfree_range(&nargs, sbp->sb_rextents,
1053                                 nsbp->sb_rextents - sbp->sb_rextents);
1054                 xfs_rtbuf_cache_relse(&nargs);
1055                 if (error) {
1056 error_cancel:
1057                         xfs_trans_cancel(tp);
1058                         break;
1059                 }
1060                 /*
1061                  * Mark more blocks free in the superblock.
1062                  */
1063                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS,
1064                         nsbp->sb_rextents - sbp->sb_rextents);
1065                 /*
1066                  * Update mp values into the real mp structure.
1067                  */
1068                 mp->m_rsumlevels = nrsumlevels;
1069                 mp->m_rsumsize = nrsumsize;
1070                 /* recompute growfsrt reservation from new rsumsize */
1071                 xfs_trans_resv_calc(mp, &mp->m_resv);
1072 
1073                 error = xfs_trans_commit(tp);
1074                 if (error)
1075                         break;
1076 
1077                 /* Ensure the mount RT feature flag is now set. */
1078                 mp->m_features |= XFS_FEAT_REALTIME;
1079         }
1080         if (error)
1081                 goto out_free;
1082 
1083         if (old_rextsize != in->extsize) {
1084                 error = xfs_growfs_rt_fixup_extsize(mp);
1085                 if (error)
1086                         goto out_free;
1087         }
1088 
1089         /* Update secondary superblocks now the physical grow has completed */
1090         error = xfs_update_secondary_sbs(mp);
1091 
1092 out_free:
1093         /*
1094          * Free the fake mp structure.
1095          */
1096         kfree(nmp);
1097 
1098         /*
1099          * If we had to allocate a new rsum_cache, we either need to free the
1100          * old one (if we succeeded) or free the new one and restore the old one
1101          * (if there was an error).
1102          */
1103         if (rsum_cache != mp->m_rsum_cache) {
1104                 if (error) {
1105                         kvfree(mp->m_rsum_cache);
1106                         mp->m_rsum_cache = rsum_cache;
1107                 } else {
1108                         kvfree(rsum_cache);
1109                 }
1110         }
1111 
1112 out_unlock:
1113         mutex_unlock(&mp->m_growlock);
1114         return error;
1115 }
1116 
1117 /*
1118  * Initialize realtime fields in the mount structure.
1119  */
1120 int                             /* error */
1121 xfs_rtmount_init(
1122         struct xfs_mount        *mp)    /* file system mount structure */
1123 {
1124         struct xfs_buf          *bp;    /* buffer for last block of subvolume */
1125         struct xfs_sb           *sbp;   /* filesystem superblock copy in mount */
1126         xfs_daddr_t             d;      /* address of last block of subvolume */
1127         unsigned int            rsumblocks;
1128         int                     error;
1129 
1130         sbp = &mp->m_sb;
1131         if (sbp->sb_rblocks == 0)
1132                 return 0;
1133         if (mp->m_rtdev_targp == NULL) {
1134                 xfs_warn(mp,
1135         "Filesystem has a realtime volume, use rtdev=device option");
1136                 return -ENODEV;
1137         }
1138         mp->m_rsumlevels = sbp->sb_rextslog + 1;
1139         rsumblocks = xfs_rtsummary_blockcount(mp, mp->m_rsumlevels,
1140                         mp->m_sb.sb_rbmblocks);
1141         mp->m_rsumsize = XFS_FSB_TO_B(mp, rsumblocks);
1142         mp->m_rbmip = mp->m_rsumip = NULL;
1143         /*
1144          * Check that the realtime section is an ok size.
1145          */
1146         d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
1147         if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_rblocks) {
1148                 xfs_warn(mp, "realtime mount -- %llu != %llu",
1149                         (unsigned long long) XFS_BB_TO_FSB(mp, d),
1150                         (unsigned long long) mp->m_sb.sb_rblocks);
1151                 return -EFBIG;
1152         }
1153         error = xfs_buf_read_uncached(mp->m_rtdev_targp,
1154                                         d - XFS_FSB_TO_BB(mp, 1),
1155                                         XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
1156         if (error) {
1157                 xfs_warn(mp, "realtime device size check failed");
1158                 return error;
1159         }
1160         xfs_buf_relse(bp);
1161         return 0;
1162 }
1163 
1164 static int
1165 xfs_rtalloc_count_frextent(
1166         struct xfs_mount                *mp,
1167         struct xfs_trans                *tp,
1168         const struct xfs_rtalloc_rec    *rec,
1169         void                            *priv)
1170 {
1171         uint64_t                        *valp = priv;
1172 
1173         *valp += rec->ar_extcount;
1174         return 0;
1175 }
1176 
1177 /*
1178  * Reinitialize the number of free realtime extents from the realtime bitmap.
1179  * Callers must ensure that there is no other activity in the filesystem.
1180  */
1181 int
1182 xfs_rtalloc_reinit_frextents(
1183         struct xfs_mount        *mp)
1184 {
1185         uint64_t                val = 0;
1186         int                     error;
1187 
1188         xfs_rtbitmap_lock_shared(mp, XFS_RBMLOCK_BITMAP);
1189         error = xfs_rtalloc_query_all(mp, NULL, xfs_rtalloc_count_frextent,
1190                         &val);
1191         xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
1192         if (error)
1193                 return error;
1194 
1195         spin_lock(&mp->m_sb_lock);
1196         mp->m_sb.sb_frextents = val;
1197         spin_unlock(&mp->m_sb_lock);
1198         percpu_counter_set(&mp->m_frextents, mp->m_sb.sb_frextents);
1199         return 0;
1200 }
1201 
1202 /*
1203  * Read in the bmbt of an rt metadata inode so that we never have to load them
1204  * at runtime.  This enables the use of shared ILOCKs for rtbitmap scans.  Use
1205  * an empty transaction to avoid deadlocking on loops in the bmbt.
1206  */
1207 static inline int
1208 xfs_rtmount_iread_extents(
1209         struct xfs_inode        *ip,
1210         unsigned int            lock_class)
1211 {
1212         struct xfs_trans        *tp;
1213         int                     error;
1214 
1215         error = xfs_trans_alloc_empty(ip->i_mount, &tp);
1216         if (error)
1217                 return error;
1218 
1219         xfs_ilock(ip, XFS_ILOCK_EXCL | lock_class);
1220 
1221         error = xfs_iread_extents(tp, ip, XFS_DATA_FORK);
1222         if (error)
1223                 goto out_unlock;
1224 
1225         if (xfs_inode_has_attr_fork(ip)) {
1226                 error = xfs_iread_extents(tp, ip, XFS_ATTR_FORK);
1227                 if (error)
1228                         goto out_unlock;
1229         }
1230 
1231 out_unlock:
1232         xfs_iunlock(ip, XFS_ILOCK_EXCL | lock_class);
1233         xfs_trans_cancel(tp);
1234         return error;
1235 }
1236 
1237 /*
1238  * Get the bitmap and summary inodes and the summary cache into the mount
1239  * structure at mount time.
1240  */
1241 int                                     /* error */
1242 xfs_rtmount_inodes(
1243         xfs_mount_t     *mp)            /* file system mount structure */
1244 {
1245         int             error;          /* error return value */
1246         xfs_sb_t        *sbp;
1247 
1248         sbp = &mp->m_sb;
1249         error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip);
1250         if (xfs_metadata_is_sick(error))
1251                 xfs_rt_mark_sick(mp, XFS_SICK_RT_BITMAP);
1252         if (error)
1253                 return error;
1254         ASSERT(mp->m_rbmip != NULL);
1255 
1256         error = xfs_rtmount_iread_extents(mp->m_rbmip, XFS_ILOCK_RTBITMAP);
1257         if (error)
1258                 goto out_rele_bitmap;
1259 
1260         error = xfs_iget(mp, NULL, sbp->sb_rsumino, 0, 0, &mp->m_rsumip);
1261         if (xfs_metadata_is_sick(error))
1262                 xfs_rt_mark_sick(mp, XFS_SICK_RT_SUMMARY);
1263         if (error)
1264                 goto out_rele_bitmap;
1265         ASSERT(mp->m_rsumip != NULL);
1266 
1267         error = xfs_rtmount_iread_extents(mp->m_rsumip, XFS_ILOCK_RTSUM);
1268         if (error)
1269                 goto out_rele_summary;
1270 
1271         xfs_alloc_rsum_cache(mp, sbp->sb_rbmblocks);
1272         return 0;
1273 
1274 out_rele_summary:
1275         xfs_irele(mp->m_rsumip);
1276 out_rele_bitmap:
1277         xfs_irele(mp->m_rbmip);
1278         return error;
1279 }
1280 
1281 void
1282 xfs_rtunmount_inodes(
1283         struct xfs_mount        *mp)
1284 {
1285         kvfree(mp->m_rsum_cache);
1286         if (mp->m_rbmip)
1287                 xfs_irele(mp->m_rbmip);
1288         if (mp->m_rsumip)
1289                 xfs_irele(mp->m_rsumip);
1290 }
1291 
1292 /*
1293  * Pick an extent for allocation at the start of a new realtime file.
1294  * Use the sequence number stored in the atime field of the bitmap inode.
1295  * Translate this to a fraction of the rtextents, and return the product
1296  * of rtextents and the fraction.
1297  * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
1298  */
1299 static int
1300 xfs_rtpick_extent(
1301         xfs_mount_t             *mp,            /* file system mount point */
1302         xfs_trans_t             *tp,            /* transaction pointer */
1303         xfs_rtxlen_t            len,            /* allocation length (rtextents) */
1304         xfs_rtxnum_t            *pick)          /* result rt extent */
1305 {
1306         xfs_rtxnum_t            b;              /* result rtext */
1307         int                     log2;           /* log of sequence number */
1308         uint64_t                resid;          /* residual after log removed */
1309         uint64_t                seq;            /* sequence number of file creation */
1310         struct timespec64       ts;             /* timespec in inode */
1311 
1312         xfs_assert_ilocked(mp->m_rbmip, XFS_ILOCK_EXCL);
1313 
1314         ts = inode_get_atime(VFS_I(mp->m_rbmip));
1315         if (!(mp->m_rbmip->i_diflags & XFS_DIFLAG_NEWRTBM)) {
1316                 mp->m_rbmip->i_diflags |= XFS_DIFLAG_NEWRTBM;
1317                 seq = 0;
1318         } else {
1319                 seq = ts.tv_sec;
1320         }
1321         if ((log2 = xfs_highbit64(seq)) == -1)
1322                 b = 0;
1323         else {
1324                 resid = seq - (1ULL << log2);
1325                 b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >>
1326                     (log2 + 1);
1327                 if (b >= mp->m_sb.sb_rextents)
1328                         div64_u64_rem(b, mp->m_sb.sb_rextents, &b);
1329                 if (b + len > mp->m_sb.sb_rextents)
1330                         b = mp->m_sb.sb_rextents - len;
1331         }
1332         ts.tv_sec = seq + 1;
1333         inode_set_atime_to_ts(VFS_I(mp->m_rbmip), ts);
1334         xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1335         *pick = b;
1336         return 0;
1337 }
1338 
1339 static void
1340 xfs_rtalloc_align_minmax(
1341         xfs_rtxlen_t            *raminlen,
1342         xfs_rtxlen_t            *ramaxlen,
1343         xfs_rtxlen_t            *prod)
1344 {
1345         xfs_rtxlen_t            newmaxlen = *ramaxlen;
1346         xfs_rtxlen_t            newminlen = *raminlen;
1347         xfs_rtxlen_t            slack;
1348 
1349         slack = newmaxlen % *prod;
1350         if (slack)
1351                 newmaxlen -= slack;
1352         slack = newminlen % *prod;
1353         if (slack)
1354                 newminlen += *prod - slack;
1355 
1356         /*
1357          * If adjusting for extent size hint alignment produces an invalid
1358          * min/max len combination, go ahead without it.
1359          */
1360         if (newmaxlen < newminlen) {
1361                 *prod = 1;
1362                 return;
1363         }
1364         *ramaxlen = newmaxlen;
1365         *raminlen = newminlen;
1366 }
1367 
1368 int
1369 xfs_bmap_rtalloc(
1370         struct xfs_bmalloca     *ap)
1371 {
1372         struct xfs_mount        *mp = ap->ip->i_mount;
1373         xfs_fileoff_t           orig_offset = ap->offset;
1374         xfs_rtxnum_t            start;     /* allocation hint rtextent no */
1375         xfs_rtxnum_t            rtx;       /* actually allocated rtextent no */
1376         xfs_rtxlen_t            prod = 0;  /* product factor for allocators */
1377         xfs_extlen_t            mod = 0;   /* product factor for allocators */
1378         xfs_rtxlen_t            ralen = 0; /* realtime allocation length */
1379         xfs_extlen_t            align;     /* minimum allocation alignment */
1380         xfs_extlen_t            orig_length = ap->length;
1381         xfs_extlen_t            minlen = mp->m_sb.sb_rextsize;
1382         xfs_rtxlen_t            raminlen;
1383         bool                    rtlocked = false;
1384         bool                    ignore_locality = false;
1385         struct xfs_rtalloc_args args = {
1386                 .mp             = mp,
1387                 .tp             = ap->tp,
1388         };
1389         int                     error;
1390 
1391         align = xfs_get_extsz_hint(ap->ip);
1392         if (!align)
1393                 align = 1;
1394 retry:
1395         error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
1396                                         align, 1, ap->eof, 0,
1397                                         ap->conv, &ap->offset, &ap->length);
1398         if (error)
1399                 return error;
1400         ASSERT(ap->length);
1401         ASSERT(xfs_extlen_to_rtxmod(mp, ap->length) == 0);
1402 
1403         /*
1404          * If we shifted the file offset downward to satisfy an extent size
1405          * hint, increase minlen by that amount so that the allocator won't
1406          * give us an allocation that's too short to cover at least one of the
1407          * blocks that the caller asked for.
1408          */
1409         if (ap->offset != orig_offset)
1410                 minlen += orig_offset - ap->offset;
1411 
1412         /*
1413          * Set ralen to be the actual requested length in rtextents.
1414          *
1415          * If the old value was close enough to XFS_BMBT_MAX_EXTLEN that
1416          * we rounded up to it, cut it back so it's valid again.
1417          * Note that if it's a really large request (bigger than
1418          * XFS_BMBT_MAX_EXTLEN), we don't hear about that number, and can't
1419          * adjust the starting point to match it.
1420          */
1421         ralen = xfs_extlen_to_rtxlen(mp, min(ap->length, XFS_MAX_BMBT_EXTLEN));
1422         raminlen = max_t(xfs_rtxlen_t, 1, xfs_extlen_to_rtxlen(mp, minlen));
1423         ASSERT(raminlen > 0);
1424         ASSERT(raminlen <= ralen);
1425 
1426         /*
1427          * Lock out modifications to both the RT bitmap and summary inodes
1428          */
1429         if (!rtlocked) {
1430                 xfs_rtbitmap_lock(ap->tp, mp);
1431                 rtlocked = true;
1432         }
1433 
1434         if (ignore_locality) {
1435                 start = 0;
1436         } else if (xfs_bmap_adjacent(ap)) {
1437                 start = xfs_rtb_to_rtx(mp, ap->blkno);
1438         } else if (ap->datatype & XFS_ALLOC_INITIAL_USER_DATA) {
1439                 /*
1440                  * If it's an allocation to an empty file at offset 0, pick an
1441                  * extent that will space things out in the rt area.
1442                  */
1443                 error = xfs_rtpick_extent(mp, ap->tp, ralen, &start);
1444                 if (error)
1445                         return error;
1446         } else {
1447                 start = 0;
1448         }
1449 
1450         /*
1451          * Only bother calculating a real prod factor if offset & length are
1452          * perfectly aligned, otherwise it will just get us in trouble.
1453          */
1454         div_u64_rem(ap->offset, align, &mod);
1455         if (mod || ap->length % align) {
1456                 prod = 1;
1457         } else {
1458                 prod = xfs_extlen_to_rtxlen(mp, align);
1459                 if (prod > 1)
1460                         xfs_rtalloc_align_minmax(&raminlen, &ralen, &prod);
1461         }
1462 
1463         if (start) {
1464                 error = xfs_rtallocate_extent_near(&args, start, raminlen,
1465                                 ralen, &ralen, prod, &rtx);
1466         } else {
1467                 error = xfs_rtallocate_extent_size(&args, raminlen,
1468                                 ralen, &ralen, prod, &rtx);
1469         }
1470         xfs_rtbuf_cache_relse(&args);
1471 
1472         if (error == -ENOSPC) {
1473                 if (align > mp->m_sb.sb_rextsize) {
1474                         /*
1475                          * We previously enlarged the request length to try to
1476                          * satisfy an extent size hint.  The allocator didn't
1477                          * return anything, so reset the parameters to the
1478                          * original values and try again without alignment
1479                          * criteria.
1480                          */
1481                         ap->offset = orig_offset;
1482                         ap->length = orig_length;
1483                         minlen = align = mp->m_sb.sb_rextsize;
1484                         goto retry;
1485                 }
1486 
1487                 if (!ignore_locality && start != 0) {
1488                         /*
1489                          * If we can't allocate near a specific rt extent, try
1490                          * again without locality criteria.
1491                          */
1492                         ignore_locality = true;
1493                         goto retry;
1494                 }
1495 
1496                 ap->blkno = NULLFSBLOCK;
1497                 ap->length = 0;
1498                 return 0;
1499         }
1500         if (error)
1501                 return error;
1502 
1503         xfs_trans_mod_sb(ap->tp, ap->wasdel ?
1504                         XFS_TRANS_SB_RES_FREXTENTS : XFS_TRANS_SB_FREXTENTS,
1505                         -(long)ralen);
1506         ap->blkno = xfs_rtx_to_rtb(mp, rtx);
1507         ap->length = xfs_rtxlen_to_extlen(mp, ralen);
1508         xfs_bmap_alloc_account(ap);
1509         return 0;
1510 }
1511 

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