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