linux-old/fs/xfs/xfs_alloc.c
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   1/*
   2 * Copyright (c) 2000-2002 Silicon Graphics, Inc.  All Rights Reserved.
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms of version 2 of the GNU General Public License as
   6 * published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it would be useful, but
   9 * WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11 *
  12 * Further, this software is distributed without any warranty that it is
  13 * free of the rightful claim of any third person regarding infringement
  14 * or the like.  Any license provided herein, whether implied or
  15 * otherwise, applies only to this software file.  Patent licenses, if
  16 * any, provided herein do not apply to combinations of this program with
  17 * other software, or any other product whatsoever.
  18 *
  19 * You should have received a copy of the GNU General Public License along
  20 * with this program; if not, write the Free Software Foundation, Inc., 59
  21 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22 *
  23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24 * Mountain View, CA  94043, or:
  25 *
  26 * http://www.sgi.com
  27 *
  28 * For further information regarding this notice, see:
  29 *
  30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31 */
  32
  33/*
  34 * Free space allocation for XFS.
  35 */
  36#include "xfs.h"
  37#include "xfs_macros.h"
  38#include "xfs_types.h"
  39#include "xfs_inum.h"
  40#include "xfs_log.h"
  41#include "xfs_trans.h"
  42#include "xfs_sb.h"
  43#include "xfs_ag.h"
  44#include "xfs_dir.h"
  45#include "xfs_dmapi.h"
  46#include "xfs_mount.h"
  47#include "xfs_alloc_btree.h"
  48#include "xfs_bmap_btree.h"
  49#include "xfs_ialloc_btree.h"
  50#include "xfs_btree.h"
  51#include "xfs_ialloc.h"
  52#include "xfs_alloc.h"
  53#include "xfs_bit.h"
  54#include "xfs_error.h"
  55
  56
  57#define XFS_ABSDIFF(a,b)        (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
  58
  59#define XFSA_FIXUP_BNO_OK       1
  60#define XFSA_FIXUP_CNT_OK       2
  61
  62int
  63xfs_alloc_search_busy(xfs_trans_t *tp,
  64                    xfs_agnumber_t agno,
  65                    xfs_agblock_t bno,
  66                    xfs_extlen_t len);
  67
  68#if defined(XFS_ALLOC_TRACE)
  69ktrace_t *xfs_alloc_trace_buf;
  70
  71#define TRACE_ALLOC(s,a)        \
  72        xfs_alloc_trace_alloc(fname, s, a, __LINE__)
  73#define TRACE_FREE(s,a,b,x,f)   \
  74        xfs_alloc_trace_free(fname, s, mp, a, b, x, f, __LINE__)
  75#define TRACE_MODAGF(s,a,f)     \
  76        xfs_alloc_trace_modagf(fname, s, mp, a, f, __LINE__)
  77#define TRACE_BUSY(fname,s,ag,agb,l,sl,tp)      \
  78        xfs_alloc_trace_busy(fname, s, mp, ag, agb, l, sl, tp, XFS_ALLOC_KTRACE_BUSY, __LINE__)
  79#define TRACE_UNBUSY(fname,s,ag,sl,tp)  \
  80        xfs_alloc_trace_busy(fname, s, mp, ag, -1, -1, sl, tp, XFS_ALLOC_KTRACE_UNBUSY, __LINE__)
  81#define TRACE_BUSYSEARCH(fname,s,ag,agb,l,sl,tp)        \
  82        xfs_alloc_trace_busy(fname, s, mp, ag, agb, l, sl, tp, XFS_ALLOC_KTRACE_BUSYSEARCH, __LINE__)
  83#else
  84#define TRACE_ALLOC(s,a)
  85#define TRACE_FREE(s,a,b,x,f)
  86#define TRACE_MODAGF(s,a,f)
  87#define TRACE_BUSY(s,a,ag,agb,l,sl,tp)
  88#define TRACE_UNBUSY(fname,s,ag,sl,tp)
  89#define TRACE_BUSYSEARCH(fname,s,ag,agb,l,sl,tp)
  90#endif  /* XFS_ALLOC_TRACE */
  91
  92/*
  93 * Prototypes for per-ag allocation routines
  94 */
  95
  96STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
  97STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
  98STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
  99STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
 100        xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
 101
 102/*
 103 * Internal functions.
 104 */
 105
 106/*
 107 * Compute aligned version of the found extent.
 108 * Takes alignment and min length into account.
 109 */
 110STATIC int                              /* success (>= minlen) */
 111xfs_alloc_compute_aligned(
 112        xfs_agblock_t   foundbno,       /* starting block in found extent */
 113        xfs_extlen_t    foundlen,       /* length in found extent */
 114        xfs_extlen_t    alignment,      /* alignment for allocation */
 115        xfs_extlen_t    minlen,         /* minimum length for allocation */
 116        xfs_agblock_t   *resbno,        /* result block number */
 117        xfs_extlen_t    *reslen)        /* result length */
 118{
 119        xfs_agblock_t   bno;
 120        xfs_extlen_t    diff;
 121        xfs_extlen_t    len;
 122
 123        if (alignment > 1 && foundlen >= minlen) {
 124                bno = roundup(foundbno, alignment);
 125                diff = bno - foundbno;
 126                len = diff >= foundlen ? 0 : foundlen - diff;
 127        } else {
 128                bno = foundbno;
 129                len = foundlen;
 130        }
 131        *resbno = bno;
 132        *reslen = len;
 133        return len >= minlen;
 134}
 135
 136/*
 137 * Compute best start block and diff for "near" allocations.
 138 * freelen >= wantlen already checked by caller.
 139 */
 140STATIC xfs_extlen_t                     /* difference value (absolute) */
 141xfs_alloc_compute_diff(
 142        xfs_agblock_t   wantbno,        /* target starting block */
 143        xfs_extlen_t    wantlen,        /* target length */
 144        xfs_extlen_t    alignment,      /* target alignment */
 145        xfs_agblock_t   freebno,        /* freespace's starting block */
 146        xfs_extlen_t    freelen,        /* freespace's length */
 147        xfs_agblock_t   *newbnop)       /* result: best start block from free */
 148{
 149        xfs_agblock_t   freeend;        /* end of freespace extent */
 150        xfs_agblock_t   newbno1;        /* return block number */
 151        xfs_agblock_t   newbno2;        /* other new block number */
 152        xfs_extlen_t    newlen1=0;      /* length with newbno1 */
 153        xfs_extlen_t    newlen2=0;      /* length with newbno2 */
 154        xfs_agblock_t   wantend;        /* end of target extent */
 155
 156        ASSERT(freelen >= wantlen);
 157        freeend = freebno + freelen;
 158        wantend = wantbno + wantlen;
 159        if (freebno >= wantbno) {
 160                if ((newbno1 = roundup(freebno, alignment)) >= freeend)
 161                        newbno1 = NULLAGBLOCK;
 162        } else if (freeend >= wantend && alignment > 1) {
 163                newbno1 = roundup(wantbno, alignment);
 164                newbno2 = newbno1 - alignment;
 165                if (newbno1 >= freeend)
 166                        newbno1 = NULLAGBLOCK;
 167                else
 168                        newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
 169                if (newbno2 < freebno)
 170                        newbno2 = NULLAGBLOCK;
 171                else
 172                        newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
 173                if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
 174                        if (newlen1 < newlen2 ||
 175                            (newlen1 == newlen2 &&
 176                             XFS_ABSDIFF(newbno1, wantbno) >
 177                             XFS_ABSDIFF(newbno2, wantbno)))
 178                                newbno1 = newbno2;
 179                } else if (newbno2 != NULLAGBLOCK)
 180                        newbno1 = newbno2;
 181        } else if (freeend >= wantend) {
 182                newbno1 = wantbno;
 183        } else if (alignment > 1) {
 184                newbno1 = roundup(freeend - wantlen, alignment);
 185                if (newbno1 > freeend - wantlen &&
 186                    newbno1 - alignment >= freebno)
 187                        newbno1 -= alignment;
 188                else if (newbno1 >= freeend)
 189                        newbno1 = NULLAGBLOCK;
 190        } else
 191                newbno1 = freeend - wantlen;
 192        *newbnop = newbno1;
 193        return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
 194}
 195
 196/*
 197 * Fix up the length, based on mod and prod.
 198 * len should be k * prod + mod for some k.
 199 * If len is too small it is returned unchanged.
 200 * If len hits maxlen it is left alone.
 201 */
 202STATIC void
 203xfs_alloc_fix_len(
 204        xfs_alloc_arg_t *args)          /* allocation argument structure */
 205{
 206        xfs_extlen_t    k;
 207        xfs_extlen_t    rlen;
 208
 209        ASSERT(args->mod < args->prod);
 210        rlen = args->len;
 211        ASSERT(rlen >= args->minlen);
 212        ASSERT(rlen <= args->maxlen);
 213        if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
 214            (args->mod == 0 && rlen < args->prod))
 215                return;
 216        k = rlen % args->prod;
 217        if (k == args->mod)
 218                return;
 219        if (k > args->mod) {
 220                if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
 221                        return;
 222        } else {
 223                if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
 224                    (int)args->minlen)
 225                        return;
 226        }
 227        ASSERT(rlen >= args->minlen);
 228        ASSERT(rlen <= args->maxlen);
 229        args->len = rlen;
 230}
 231
 232/*
 233 * Fix up length if there is too little space left in the a.g.
 234 * Return 1 if ok, 0 if too little, should give up.
 235 */
 236STATIC int
 237xfs_alloc_fix_minleft(
 238        xfs_alloc_arg_t *args)          /* allocation argument structure */
 239{
 240        xfs_agf_t       *agf;           /* a.g. freelist header */
 241        int             diff;           /* free space difference */
 242
 243        if (args->minleft == 0)
 244                return 1;
 245        agf = XFS_BUF_TO_AGF(args->agbp);
 246        diff = INT_GET(agf->agf_freeblks, ARCH_CONVERT)
 247                + INT_GET(agf->agf_flcount, ARCH_CONVERT)
 248                - args->len - args->minleft;
 249        if (diff >= 0)
 250                return 1;
 251        args->len += diff;              /* shrink the allocated space */
 252        if (args->len >= args->minlen)
 253                return 1;
 254        args->agbno = NULLAGBLOCK;
 255        return 0;
 256}
 257
 258/*
 259 * Update the two btrees, logically removing from freespace the extent
 260 * starting at rbno, rlen blocks.  The extent is contained within the
 261 * actual (current) free extent fbno for flen blocks.
 262 * Flags are passed in indicating whether the cursors are set to the
 263 * relevant records.
 264 */
 265STATIC int                              /* error code */
 266xfs_alloc_fixup_trees(
 267        xfs_btree_cur_t *cnt_cur,       /* cursor for by-size btree */
 268        xfs_btree_cur_t *bno_cur,       /* cursor for by-block btree */
 269        xfs_agblock_t   fbno,           /* starting block of free extent */
 270        xfs_extlen_t    flen,           /* length of free extent */
 271        xfs_agblock_t   rbno,           /* starting block of returned extent */
 272        xfs_extlen_t    rlen,           /* length of returned extent */
 273        int             flags)          /* flags, XFSA_FIXUP_... */
 274{
 275        int             error;          /* error code */
 276        int             i;              /* operation results */
 277        xfs_agblock_t   nfbno1;         /* first new free startblock */
 278        xfs_agblock_t   nfbno2;         /* second new free startblock */
 279        xfs_extlen_t    nflen1=0;       /* first new free length */
 280        xfs_extlen_t    nflen2=0;       /* second new free length */
 281
 282        /*
 283         * Look up the record in the by-size tree if necessary.
 284         */
 285        if (flags & XFSA_FIXUP_CNT_OK) {
 286#ifdef DEBUG
 287                if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
 288                        return error;
 289                XFS_WANT_CORRUPTED_RETURN(
 290                        i == 1 && nfbno1 == fbno && nflen1 == flen);
 291#endif
 292        } else {
 293                if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
 294                        return error;
 295                XFS_WANT_CORRUPTED_RETURN(i == 1);
 296        }
 297        /*
 298         * Look up the record in the by-block tree if necessary.
 299         */
 300        if (flags & XFSA_FIXUP_BNO_OK) {
 301#ifdef DEBUG
 302                if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
 303                        return error;
 304                XFS_WANT_CORRUPTED_RETURN(
 305                        i == 1 && nfbno1 == fbno && nflen1 == flen);
 306#endif
 307        } else {
 308                if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
 309                        return error;
 310                XFS_WANT_CORRUPTED_RETURN(i == 1);
 311        }
 312#ifdef DEBUG
 313        {
 314                xfs_alloc_block_t       *bnoblock;
 315                xfs_alloc_block_t       *cntblock;
 316
 317                if (bno_cur->bc_nlevels == 1 &&
 318                    cnt_cur->bc_nlevels == 1) {
 319                        bnoblock = XFS_BUF_TO_ALLOC_BLOCK(bno_cur->bc_bufs[0]);
 320                        cntblock = XFS_BUF_TO_ALLOC_BLOCK(cnt_cur->bc_bufs[0]);
 321                        XFS_WANT_CORRUPTED_RETURN(
 322                                INT_GET(bnoblock->bb_numrecs, ARCH_CONVERT) == INT_GET(cntblock->bb_numrecs, ARCH_CONVERT));
 323                }
 324        }
 325#endif
 326        /*
 327         * Deal with all four cases: the allocated record is contained
 328         * within the freespace record, so we can have new freespace
 329         * at either (or both) end, or no freespace remaining.
 330         */
 331        if (rbno == fbno && rlen == flen)
 332                nfbno1 = nfbno2 = NULLAGBLOCK;
 333        else if (rbno == fbno) {
 334                nfbno1 = rbno + rlen;
 335                nflen1 = flen - rlen;
 336                nfbno2 = NULLAGBLOCK;
 337        } else if (rbno + rlen == fbno + flen) {
 338                nfbno1 = fbno;
 339                nflen1 = flen - rlen;
 340                nfbno2 = NULLAGBLOCK;
 341        } else {
 342                nfbno1 = fbno;
 343                nflen1 = rbno - fbno;
 344                nfbno2 = rbno + rlen;
 345                nflen2 = (fbno + flen) - nfbno2;
 346        }
 347        /*
 348         * Delete the entry from the by-size btree.
 349         */
 350        if ((error = xfs_alloc_delete(cnt_cur, &i)))
 351                return error;
 352        XFS_WANT_CORRUPTED_RETURN(i == 1);
 353        /*
 354         * Add new by-size btree entry(s).
 355         */
 356        if (nfbno1 != NULLAGBLOCK) {
 357                if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
 358                        return error;
 359                XFS_WANT_CORRUPTED_RETURN(i == 0);
 360                if ((error = xfs_alloc_insert(cnt_cur, &i)))
 361                        return error;
 362                XFS_WANT_CORRUPTED_RETURN(i == 1);
 363        }
 364        if (nfbno2 != NULLAGBLOCK) {
 365                if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
 366                        return error;
 367                XFS_WANT_CORRUPTED_RETURN(i == 0);
 368                if ((error = xfs_alloc_insert(cnt_cur, &i)))
 369                        return error;
 370                XFS_WANT_CORRUPTED_RETURN(i == 1);
 371        }
 372        /*
 373         * Fix up the by-block btree entry(s).
 374         */
 375        if (nfbno1 == NULLAGBLOCK) {
 376                /*
 377                 * No remaining freespace, just delete the by-block tree entry.
 378                 */
 379                if ((error = xfs_alloc_delete(bno_cur, &i)))
 380                        return error;
 381                XFS_WANT_CORRUPTED_RETURN(i == 1);
 382        } else {
 383                /*
 384                 * Update the by-block entry to start later|be shorter.
 385                 */
 386                if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
 387                        return error;
 388        }
 389        if (nfbno2 != NULLAGBLOCK) {
 390                /*
 391                 * 2 resulting free entries, need to add one.
 392                 */
 393                if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
 394                        return error;
 395                XFS_WANT_CORRUPTED_RETURN(i == 0);
 396                if ((error = xfs_alloc_insert(bno_cur, &i)))
 397                        return error;
 398                XFS_WANT_CORRUPTED_RETURN(i == 1);
 399        }
 400        return 0;
 401}
 402
 403/*
 404 * Read in the allocation group free block array.
 405 */
 406STATIC int                              /* error */
 407xfs_alloc_read_agfl(
 408        xfs_mount_t     *mp,            /* mount point structure */
 409        xfs_trans_t     *tp,            /* transaction pointer */
 410        xfs_agnumber_t  agno,           /* allocation group number */
 411        xfs_buf_t       **bpp)          /* buffer for the ag free block array */
 412{
 413        xfs_buf_t       *bp;            /* return value */
 414        int             error;
 415
 416        ASSERT(agno != NULLAGNUMBER);
 417        error = xfs_trans_read_buf(
 418                        mp, tp, mp->m_ddev_targp,
 419                        XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
 420                        XFS_FSS_TO_BB(mp, 1), 0, &bp);
 421        if (error)
 422                return error;
 423        ASSERT(bp);
 424        ASSERT(!XFS_BUF_GETERROR(bp));
 425        XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGFL, XFS_AGFL_REF);
 426        *bpp = bp;
 427        return 0;
 428}
 429
 430#if defined(XFS_ALLOC_TRACE)
 431/*
 432 * Add an allocation trace entry for an alloc call.
 433 */
 434STATIC void
 435xfs_alloc_trace_alloc(
 436        char            *name,          /* function tag string */
 437        char            *str,           /* additional string */
 438        xfs_alloc_arg_t *args,          /* allocation argument structure */
 439        int             line)           /* source line number */
 440{
 441        ktrace_enter(xfs_alloc_trace_buf,
 442                (void *)(__psint_t)(XFS_ALLOC_KTRACE_ALLOC | (line << 16)),
 443                (void *)name,
 444                (void *)str,
 445                (void *)args->mp,
 446                (void *)(__psunsigned_t)args->agno,
 447                (void *)(__psunsigned_t)args->agbno,
 448                (void *)(__psunsigned_t)args->minlen,
 449                (void *)(__psunsigned_t)args->maxlen,
 450                (void *)(__psunsigned_t)args->mod,
 451                (void *)(__psunsigned_t)args->prod,
 452                (void *)(__psunsigned_t)args->minleft,
 453                (void *)(__psunsigned_t)args->total,
 454                (void *)(__psunsigned_t)args->alignment,
 455                (void *)(__psunsigned_t)args->len,
 456                (void *)((((__psint_t)args->type) << 16) |
 457                         (__psint_t)args->otype),
 458                (void *)(__psint_t)((args->wasdel << 3) |
 459                                    (args->wasfromfl << 2) |
 460                                    (args->isfl << 1) |
 461                                    (args->userdata << 0)));
 462}
 463
 464/*
 465 * Add an allocation trace entry for a free call.
 466 */
 467STATIC void
 468xfs_alloc_trace_free(
 469        char            *name,          /* function tag string */
 470        char            *str,           /* additional string */
 471        xfs_mount_t     *mp,            /* file system mount point */
 472        xfs_agnumber_t  agno,           /* allocation group number */
 473        xfs_agblock_t   agbno,          /* a.g. relative block number */
 474        xfs_extlen_t    len,            /* length of extent */
 475        int             isfl,           /* set if is freelist allocation/free */
 476        int             line)           /* source line number */
 477{
 478        ktrace_enter(xfs_alloc_trace_buf,
 479                (void *)(__psint_t)(XFS_ALLOC_KTRACE_FREE | (line << 16)),
 480                (void *)name,
 481                (void *)str,
 482                (void *)mp,
 483                (void *)(__psunsigned_t)agno,
 484                (void *)(__psunsigned_t)agbno,
 485                (void *)(__psunsigned_t)len,
 486                (void *)(__psint_t)isfl,
 487                NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
 488}
 489
 490/*
 491 * Add an allocation trace entry for modifying an agf.
 492 */
 493STATIC void
 494xfs_alloc_trace_modagf(
 495        char            *name,          /* function tag string */
 496        char            *str,           /* additional string */
 497        xfs_mount_t     *mp,            /* file system mount point */
 498        xfs_agf_t       *agf,           /* new agf value */
 499        int             flags,          /* logging flags for agf */
 500        int             line)           /* source line number */
 501{
 502        ktrace_enter(xfs_alloc_trace_buf,
 503                (void *)(__psint_t)(XFS_ALLOC_KTRACE_MODAGF | (line << 16)),
 504                (void *)name,
 505                (void *)str,
 506                (void *)mp,
 507                (void *)(__psint_t)flags,
 508                (void *)(__psunsigned_t)INT_GET(agf->agf_seqno, ARCH_CONVERT),
 509                (void *)(__psunsigned_t)INT_GET(agf->agf_length, ARCH_CONVERT),
 510                (void *)(__psunsigned_t)INT_GET(agf->agf_roots[XFS_BTNUM_BNO],
 511                                                ARCH_CONVERT),
 512                (void *)(__psunsigned_t)INT_GET(agf->agf_roots[XFS_BTNUM_CNT],
 513                                                ARCH_CONVERT),
 514                (void *)(__psunsigned_t)INT_GET(agf->agf_levels[XFS_BTNUM_BNO],
 515                                                ARCH_CONVERT),
 516                (void *)(__psunsigned_t)INT_GET(agf->agf_levels[XFS_BTNUM_CNT],
 517                                                ARCH_CONVERT),
 518                (void *)(__psunsigned_t)INT_GET(agf->agf_flfirst, ARCH_CONVERT),
 519                (void *)(__psunsigned_t)INT_GET(agf->agf_fllast, ARCH_CONVERT),
 520                (void *)(__psunsigned_t)INT_GET(agf->agf_flcount, ARCH_CONVERT),
 521                (void *)(__psunsigned_t)INT_GET(agf->agf_freeblks, ARCH_CONVERT),
 522                (void *)(__psunsigned_t)INT_GET(agf->agf_longest, ARCH_CONVERT));
 523}
 524
 525STATIC void
 526xfs_alloc_trace_busy(
 527        char            *name,          /* function tag string */
 528        char            *str,           /* additional string */
 529        xfs_mount_t     *mp,            /* file system mount poing */
 530        xfs_agnumber_t  agno,           /* allocation group number */
 531        xfs_agblock_t   agbno,          /* a.g. relative block number */
 532        xfs_extlen_t    len,            /* length of extent */
 533        int             slot,           /* perag Busy slot */
 534        xfs_trans_t     *tp,
 535        int             trtype,         /* type: add, delete, search */
 536        int             line)           /* source line number */
 537{
 538        ktrace_enter(xfs_alloc_trace_buf,
 539                (void *)(__psint_t)(trtype | (line << 16)),
 540                (void *)name,
 541                (void *)str,
 542                (void *)mp,
 543                (void *)(__psunsigned_t)agno,
 544                (void *)(__psunsigned_t)agbno,
 545                (void *)(__psunsigned_t)len,
 546                (void *)(__psint_t)slot,
 547                (void *)tp,
 548                NULL, NULL, NULL, NULL, NULL, NULL, NULL);
 549}
 550#endif  /* XFS_ALLOC_TRACE */
 551
 552/*
 553 * Allocation group level functions.
 554 */
 555
 556/*
 557 * Allocate a variable extent in the allocation group agno.
 558 * Type and bno are used to determine where in the allocation group the
 559 * extent will start.
 560 * Extent's length (returned in *len) will be between minlen and maxlen,
 561 * and of the form k * prod + mod unless there's nothing that large.
 562 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
 563 */
 564STATIC int                      /* error */
 565xfs_alloc_ag_vextent(
 566        xfs_alloc_arg_t *args)  /* argument structure for allocation */
 567{
 568        int             error=0;
 569#ifdef XFS_ALLOC_TRACE
 570        static char     fname[] = "xfs_alloc_ag_vextent";
 571#endif
 572
 573        ASSERT(args->minlen > 0);
 574        ASSERT(args->maxlen > 0);
 575        ASSERT(args->minlen <= args->maxlen);
 576        ASSERT(args->mod < args->prod);
 577        ASSERT(args->alignment > 0);
 578        /*
 579         * Branch to correct routine based on the type.
 580         */
 581        args->wasfromfl = 0;
 582        switch (args->type) {
 583        case XFS_ALLOCTYPE_THIS_AG:
 584                error = xfs_alloc_ag_vextent_size(args);
 585                break;
 586        case XFS_ALLOCTYPE_NEAR_BNO:
 587                error = xfs_alloc_ag_vextent_near(args);
 588                break;
 589        case XFS_ALLOCTYPE_THIS_BNO:
 590                error = xfs_alloc_ag_vextent_exact(args);
 591                break;
 592        default:
 593                ASSERT(0);
 594                /* NOTREACHED */
 595        }
 596        if (error)
 597                return error;
 598        /*
 599         * If the allocation worked, need to change the agf structure
 600         * (and log it), and the superblock.
 601         */
 602        if (args->agbno != NULLAGBLOCK) {
 603                xfs_agf_t       *agf;   /* allocation group freelist header */
 604#ifdef XFS_ALLOC_TRACE
 605                xfs_mount_t     *mp = args->mp;
 606#endif
 607                long            slen = (long)args->len;
 608
 609                ASSERT(args->len >= args->minlen && args->len <= args->maxlen);
 610                ASSERT(!(args->wasfromfl) || !args->isfl);
 611                ASSERT(args->agbno % args->alignment == 0);
 612                if (!(args->wasfromfl)) {
 613
 614                        agf = XFS_BUF_TO_AGF(args->agbp);
 615                        INT_MOD(agf->agf_freeblks, ARCH_CONVERT, -(args->len));
 616                        xfs_trans_agblocks_delta(args->tp,
 617                                                 -((long)(args->len)));
 618                        args->pag->pagf_freeblks -= args->len;
 619                        ASSERT(INT_GET(agf->agf_freeblks, ARCH_CONVERT)
 620                                <= INT_GET(agf->agf_length, ARCH_CONVERT));
 621                        TRACE_MODAGF(NULL, agf, XFS_AGF_FREEBLKS);
 622                        xfs_alloc_log_agf(args->tp, args->agbp,
 623                                                XFS_AGF_FREEBLKS);
 624                        /* search the busylist for these blocks */
 625                        xfs_alloc_search_busy(args->tp, args->agno,
 626                                        args->agbno, args->len);
 627                }
 628                if (!args->isfl)
 629                        xfs_trans_mod_sb(args->tp,
 630                                args->wasdel ? XFS_TRANS_SB_RES_FDBLOCKS :
 631                                        XFS_TRANS_SB_FDBLOCKS, -slen);
 632                XFS_STATS_INC(xs_allocx);
 633                XFS_STATS_ADD(xs_allocb, args->len);
 634        }
 635        return 0;
 636}
 637
 638/*
 639 * Allocate a variable extent at exactly agno/bno.
 640 * Extent's length (returned in *len) will be between minlen and maxlen,
 641 * and of the form k * prod + mod unless there's nothing that large.
 642 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
 643 */
 644STATIC int                      /* error */
 645xfs_alloc_ag_vextent_exact(
 646        xfs_alloc_arg_t *args)  /* allocation argument structure */
 647{
 648        xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
 649        xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
 650        xfs_agblock_t   end;    /* end of allocated extent */
 651        int             error;
 652        xfs_agblock_t   fbno;   /* start block of found extent */
 653        xfs_agblock_t   fend;   /* end block of found extent */
 654        xfs_extlen_t    flen;   /* length of found extent */
 655#ifdef XFS_ALLOC_TRACE
 656        static char     fname[] = "xfs_alloc_ag_vextent_exact";
 657#endif
 658        int             i;      /* success/failure of operation */
 659        xfs_agblock_t   maxend; /* end of maximal extent */
 660        xfs_agblock_t   minend; /* end of minimal extent */
 661        xfs_extlen_t    rlen;   /* length of returned extent */
 662
 663        ASSERT(args->alignment == 1);
 664        /*
 665         * Allocate/initialize a cursor for the by-number freespace btree.
 666         */
 667        bno_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
 668                args->agno, XFS_BTNUM_BNO, NULL, 0);
 669        /*
 670         * Lookup bno and minlen in the btree (minlen is irrelevant, really).
 671         * Look for the closest free block <= bno, it must contain bno
 672         * if any free block does.
 673         */
 674        if ((error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i)))
 675                goto error0;
 676        if (!i) {
 677                /*
 678                 * Didn't find it, return null.
 679                 */
 680                xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
 681                args->agbno = NULLAGBLOCK;
 682                return 0;
 683        }
 684        /*
 685         * Grab the freespace record.
 686         */
 687        if ((error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i)))
 688                goto error0;
 689        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 690        ASSERT(fbno <= args->agbno);
 691        minend = args->agbno + args->minlen;
 692        maxend = args->agbno + args->maxlen;
 693        fend = fbno + flen;
 694        /*
 695         * Give up if the freespace isn't long enough for the minimum request.
 696         */
 697        if (fend < minend) {
 698                xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
 699                args->agbno = NULLAGBLOCK;
 700                return 0;
 701        }
 702        /*
 703         * End of extent will be smaller of the freespace end and the
 704         * maximal requested end.
 705         */
 706        end = XFS_AGBLOCK_MIN(fend, maxend);
 707        /*
 708         * Fix the length according to mod and prod if given.
 709         */
 710        args->len = end - args->agbno;
 711        xfs_alloc_fix_len(args);
 712        if (!xfs_alloc_fix_minleft(args)) {
 713                xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
 714                return 0;
 715        }
 716        rlen = args->len;
 717        ASSERT(args->agbno + rlen <= fend);
 718        end = args->agbno + rlen;
 719        /*
 720         * We are allocating agbno for rlen [agbno .. end]
 721         * Allocate/initialize a cursor for the by-size btree.
 722         */
 723        cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
 724                args->agno, XFS_BTNUM_CNT, NULL, 0);
 725        ASSERT(args->agbno + args->len <=
 726                INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
 727                        ARCH_CONVERT));
 728        if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
 729                        args->agbno, args->len, XFSA_FIXUP_BNO_OK))) {
 730                xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
 731                goto error0;
 732        }
 733        xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
 734        xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
 735        TRACE_ALLOC("normal", args);
 736        args->wasfromfl = 0;
 737        return 0;
 738
 739error0:
 740        xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
 741        TRACE_ALLOC("error", args);
 742        return error;
 743}
 744
 745/*
 746 * Allocate a variable extent near bno in the allocation group agno.
 747 * Extent's length (returned in len) will be between minlen and maxlen,
 748 * and of the form k * prod + mod unless there's nothing that large.
 749 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
 750 */
 751STATIC int                              /* error */
 752xfs_alloc_ag_vextent_near(
 753        xfs_alloc_arg_t *args)          /* allocation argument structure */
 754{
 755        xfs_btree_cur_t *bno_cur_gt;    /* cursor for bno btree, right side */
 756        xfs_btree_cur_t *bno_cur_lt;    /* cursor for bno btree, left side */
 757        xfs_btree_cur_t *cnt_cur;       /* cursor for count btree */
 758#ifdef XFS_ALLOC_TRACE
 759        static char     fname[] = "xfs_alloc_ag_vextent_near";
 760#endif
 761        xfs_agblock_t   gtbno;          /* start bno of right side entry */
 762        xfs_agblock_t   gtbnoa;         /* aligned ... */
 763        xfs_extlen_t    gtdiff;         /* difference to right side entry */
 764        xfs_extlen_t    gtlen;          /* length of right side entry */
 765        xfs_extlen_t    gtlena;         /* aligned ... */
 766        xfs_agblock_t   gtnew;          /* useful start bno of right side */
 767        int             error;          /* error code */
 768        int             i;              /* result code, temporary */
 769        int             j;              /* result code, temporary */
 770        xfs_agblock_t   ltbno;          /* start bno of left side entry */
 771        xfs_agblock_t   ltbnoa;         /* aligned ... */
 772        xfs_extlen_t    ltdiff;         /* difference to left side entry */
 773        /*REFERENCED*/
 774        xfs_agblock_t   ltend;          /* end bno of left side entry */
 775        xfs_extlen_t    ltlen;          /* length of left side entry */
 776        xfs_extlen_t    ltlena;         /* aligned ... */
 777        xfs_agblock_t   ltnew;          /* useful start bno of left side */
 778        xfs_extlen_t    rlen;           /* length of returned extent */
 779#if defined(DEBUG) && defined(__KERNEL__)
 780        /*
 781         * Randomly don't execute the first algorithm.
 782         */
 783        int             dofirst;        /* set to do first algorithm */
 784
 785        dofirst = random() & 1;
 786#endif
 787        /*
 788         * Get a cursor for the by-size btree.
 789         */
 790        cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
 791                args->agno, XFS_BTNUM_CNT, NULL, 0);
 792        ltlen = 0;
 793        bno_cur_lt = bno_cur_gt = NULL;
 794        /*
 795         * See if there are any free extents as big as maxlen.
 796         */
 797        if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
 798                goto error0;
 799        /*
 800         * If none, then pick up the last entry in the tree unless the
 801         * tree is empty.
 802         */
 803        if (!i) {
 804                if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &ltbno,
 805                                &ltlen, &i)))
 806                        goto error0;
 807                if (i == 0 || ltlen == 0) {
 808                        xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
 809                        return 0;
 810                }
 811                ASSERT(i == 1);
 812        }
 813        args->wasfromfl = 0;
 814        /*
 815         * First algorithm.
 816         * If the requested extent is large wrt the freespaces available
 817         * in this a.g., then the cursor will be pointing to a btree entry
 818         * near the right edge of the tree.  If it's in the last btree leaf
 819         * block, then we just examine all the entries in that block
 820         * that are big enough, and pick the best one.
 821         * This is written as a while loop so we can break out of it,
 822         * but we never loop back to the top.
 823         */
 824        while (xfs_btree_islastblock(cnt_cur, 0)) {
 825                xfs_extlen_t    bdiff;
 826                int             besti=0;
 827                xfs_extlen_t    blen=0;
 828                xfs_agblock_t   bnew=0;
 829
 830#if defined(DEBUG) && defined(__KERNEL__)
 831                if (!dofirst)
 832                        break;
 833#endif
 834                /*
 835                 * Start from the entry that lookup found, sequence through
 836                 * all larger free blocks.  If we're actually pointing at a
 837                 * record smaller than maxlen, go to the start of this block,
 838                 * and skip all those smaller than minlen.
 839                 */
 840                if (ltlen || args->alignment > 1) {
 841                        cnt_cur->bc_ptrs[0] = 1;
 842                        do {
 843                                if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno,
 844                                                &ltlen, &i)))
 845                                        goto error0;
 846                                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 847                                if (ltlen >= args->minlen)
 848                                        break;
 849                                if ((error = xfs_alloc_increment(cnt_cur, 0, &i)))
 850                                        goto error0;
 851                        } while (i);
 852                        ASSERT(ltlen >= args->minlen);
 853                        if (!i)
 854                                break;
 855                }
 856                i = cnt_cur->bc_ptrs[0];
 857                for (j = 1, blen = 0, bdiff = 0;
 858                     !error && j && (blen < args->maxlen || bdiff > 0);
 859                     error = xfs_alloc_increment(cnt_cur, 0, &j)) {
 860                        /*
 861                         * For each entry, decide if it's better than
 862                         * the previous best entry.
 863                         */
 864                        if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
 865                                goto error0;
 866                        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 867                        if (!xfs_alloc_compute_aligned(ltbno, ltlen,
 868                                        args->alignment, args->minlen,
 869                                        &ltbnoa, &ltlena))
 870                                continue;
 871                        args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
 872                        xfs_alloc_fix_len(args);
 873                        ASSERT(args->len >= args->minlen);
 874                        if (args->len < blen)
 875                                continue;
 876                        ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
 877                                args->alignment, ltbno, ltlen, &ltnew);
 878                        if (ltnew != NULLAGBLOCK &&
 879                            (args->len > blen || ltdiff < bdiff)) {
 880                                bdiff = ltdiff;
 881                                bnew = ltnew;
 882                                blen = args->len;
 883                                besti = cnt_cur->bc_ptrs[0];
 884                        }
 885                }
 886                /*
 887                 * It didn't work.  We COULD be in a case where
 888                 * there's a good record somewhere, so try again.
 889                 */
 890                if (blen == 0)
 891                        break;
 892                /*
 893                 * Point at the best entry, and retrieve it again.
 894                 */
 895                cnt_cur->bc_ptrs[0] = besti;
 896                if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
 897                        goto error0;
 898                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 899                ltend = ltbno + ltlen;
 900                ASSERT(ltend <= INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
 901                                ARCH_CONVERT));
 902                args->len = blen;
 903                if (!xfs_alloc_fix_minleft(args)) {
 904                        xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
 905                        TRACE_ALLOC("nominleft", args);
 906                        return 0;
 907                }
 908                blen = args->len;
 909                /*
 910                 * We are allocating starting at bnew for blen blocks.
 911                 */
 912                args->agbno = bnew;
 913                ASSERT(bnew >= ltbno);
 914                ASSERT(bnew + blen <= ltend);
 915                /*
 916                 * Set up a cursor for the by-bno tree.
 917                 */
 918                bno_cur_lt = xfs_btree_init_cursor(args->mp, args->tp,
 919                        args->agbp, args->agno, XFS_BTNUM_BNO, NULL, 0);
 920                /*
 921                 * Fix up the btree entries.
 922                 */
 923                if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
 924                                ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
 925                        goto error0;
 926                xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
 927                xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
 928                TRACE_ALLOC("first", args);
 929                return 0;
 930        }
 931        /*
 932         * Second algorithm.
 933         * Search in the by-bno tree to the left and to the right
 934         * simultaneously, until in each case we find a space big enough,
 935         * or run into the edge of the tree.  When we run into the edge,
 936         * we deallocate that cursor.
 937         * If both searches succeed, we compare the two spaces and pick
 938         * the better one.
 939         * With alignment, it's possible for both to fail; the upper
 940         * level algorithm that picks allocation groups for allocations
 941         * is not supposed to do this.
 942         */
 943        /*
 944         * Allocate and initialize the cursor for the leftward search.
 945         */
 946        bno_cur_lt = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
 947                args->agno, XFS_BTNUM_BNO, NULL, 0);
 948        /*
 949         * Lookup <= bno to find the leftward search's starting point.
 950         */
 951        if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
 952                goto error0;
 953        if (!i) {
 954                /*
 955                 * Didn't find anything; use this cursor for the rightward
 956                 * search.
 957                 */
 958                bno_cur_gt = bno_cur_lt;
 959                bno_cur_lt = NULL;
 960        }
 961        /*
 962         * Found something.  Duplicate the cursor for the rightward search.
 963         */
 964        else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
 965                goto error0;
 966        /*
 967         * Increment the cursor, so we will point at the entry just right
 968         * of the leftward entry if any, or to the leftmost entry.
 969         */
 970        if ((error = xfs_alloc_increment(bno_cur_gt, 0, &i)))
 971                goto error0;
 972        if (!i) {
 973                /*
 974                 * It failed, there are no rightward entries.
 975                 */
 976                xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
 977                bno_cur_gt = NULL;
 978        }
 979        /*
 980         * Loop going left with the leftward cursor, right with the
 981         * rightward cursor, until either both directions give up or
 982         * we find an entry at least as big as minlen.
 983         */
 984        do {
 985                if (bno_cur_lt) {
 986                        if ((error = xfs_alloc_get_rec(bno_cur_lt, &ltbno, &ltlen, &i)))
 987                                goto error0;
 988                        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 989                        if (xfs_alloc_compute_aligned(ltbno, ltlen,
 990                                        args->alignment, args->minlen,
 991                                        &ltbnoa, &ltlena))
 992                                break;
 993                        if ((error = xfs_alloc_decrement(bno_cur_lt, 0, &i)))
 994                                goto error0;
 995                        if (!i) {
 996                                xfs_btree_del_cursor(bno_cur_lt,
 997                                                     XFS_BTREE_NOERROR);
 998                                bno_cur_lt = NULL;
 999                        }
1000                }
1001                if (bno_cur_gt) {
1002                        if ((error = xfs_alloc_get_rec(bno_cur_gt, &gtbno, &gtlen, &i)))
1003                                goto error0;
1004                        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1005                        if (xfs_alloc_compute_aligned(gtbno, gtlen,
1006                                        args->alignment, args->minlen,
1007                                        &gtbnoa, &gtlena))
1008                                break;
1009                        if ((error = xfs_alloc_increment(bno_cur_gt, 0, &i)))
1010                                goto error0;
1011                        if (!i) {
1012                                xfs_btree_del_cursor(bno_cur_gt,
1013                                                     XFS_BTREE_NOERROR);
1014                                bno_cur_gt = NULL;
1015                        }
1016                }
1017        } while (bno_cur_lt || bno_cur_gt);
1018        /*
1019         * Got both cursors still active, need to find better entry.
1020         */
1021        if (bno_cur_lt && bno_cur_gt) {
1022                /*
1023                 * Left side is long enough, look for a right side entry.
1024                 */
1025                if (ltlena >= args->minlen) {
1026                        /*
1027                         * Fix up the length.
1028                         */
1029                        args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1030                        xfs_alloc_fix_len(args);
1031                        rlen = args->len;
1032                        ltdiff = xfs_alloc_compute_diff(args->agbno, rlen,
1033                                args->alignment, ltbno, ltlen, &ltnew);
1034                        /*
1035                         * Not perfect.
1036                         */
1037                        if (ltdiff) {
1038                                /*
1039                                 * Look until we find a better one, run out of
1040                                 * space, or run off the end.
1041                                 */
1042                                while (bno_cur_lt && bno_cur_gt) {
1043                                        if ((error = xfs_alloc_get_rec(
1044                                                        bno_cur_gt, &gtbno,
1045                                                        &gtlen, &i)))
1046                                                goto error0;
1047                                        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1048                                        xfs_alloc_compute_aligned(gtbno, gtlen,
1049                                                args->alignment, args->minlen,
1050                                                &gtbnoa, &gtlena);
1051                                        /*
1052                                         * The left one is clearly better.
1053                                         */
1054                                        if (gtbnoa >= args->agbno + ltdiff) {
1055                                                xfs_btree_del_cursor(
1056                                                        bno_cur_gt,
1057                                                        XFS_BTREE_NOERROR);
1058                                                bno_cur_gt = NULL;
1059                                                break;
1060                                        }
1061                                        /*
1062                                         * If we reach a big enough entry,
1063                                         * compare the two and pick the best.
1064                                         */
1065                                        if (gtlena >= args->minlen) {
1066                                                args->len =
1067                                                        XFS_EXTLEN_MIN(gtlena,
1068                                                                args->maxlen);
1069                                                xfs_alloc_fix_len(args);
1070                                                rlen = args->len;
1071                                                gtdiff = xfs_alloc_compute_diff(
1072                                                        args->agbno, rlen,
1073                                                        args->alignment,
1074                                                        gtbno, gtlen, &gtnew);
1075                                                /*
1076                                                 * Right side is better.
1077                                                 */
1078                                                if (gtdiff < ltdiff) {
1079                                                        xfs_btree_del_cursor(
1080                                                                bno_cur_lt,
1081                                                                XFS_BTREE_NOERROR);
1082                                                        bno_cur_lt = NULL;
1083                                                }
1084                                                /*
1085                                                 * Left side is better.
1086                                                 */
1087                                                else {
1088                                                        xfs_btree_del_cursor(
1089                                                                bno_cur_gt,
1090                                                                XFS_BTREE_NOERROR);
1091                                                        bno_cur_gt = NULL;
1092                                                }
1093                                                break;
1094                                        }
1095                                        /*
1096                                         * Fell off the right end.
1097                                         */
1098                                        if ((error = xfs_alloc_increment(
1099                                                        bno_cur_gt, 0, &i)))
1100                                                goto error0;
1101                                        if (!i) {
1102                                                xfs_btree_del_cursor(
1103                                                        bno_cur_gt,
1104                                                        XFS_BTREE_NOERROR);
1105                                                bno_cur_gt = NULL;
1106                                                break;
1107                                        }
1108                                }
1109                        }
1110                        /*
1111                         * The left side is perfect, trash the right side.
1112                         */
1113                        else {
1114                                xfs_btree_del_cursor(bno_cur_gt,
1115                                                     XFS_BTREE_NOERROR);
1116                                bno_cur_gt = NULL;
1117                        }
1118                }
1119                /*
1120                 * It's the right side that was found first, look left.
1121                 */
1122                else {
1123                        /*
1124                         * Fix up the length.
1125                         */
1126                        args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1127                        xfs_alloc_fix_len(args);
1128                        rlen = args->len;
1129                        gtdiff = xfs_alloc_compute_diff(args->agbno, rlen,
1130                                args->alignment, gtbno, gtlen, &gtnew);
1131                        /*
1132                         * Right side entry isn't perfect.
1133                         */
1134                        if (gtdiff) {
1135                                /*
1136                                 * Look until we find a better one, run out of
1137                                 * space, or run off the end.
1138                                 */
1139                                while (bno_cur_lt && bno_cur_gt) {
1140                                        if ((error = xfs_alloc_get_rec(
1141                                                        bno_cur_lt, &ltbno,
1142                                                        &ltlen, &i)))
1143                                                goto error0;
1144                                        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1145                                        xfs_alloc_compute_aligned(ltbno, ltlen,
1146                                                args->alignment, args->minlen,
1147                                                &ltbnoa, &ltlena);
1148                                        /*
1149                                         * The right one is clearly better.
1150                                         */
1151                                        if (ltbnoa <= args->agbno - gtdiff) {
1152                                                xfs_btree_del_cursor(
1153                                                        bno_cur_lt,
1154                                                        XFS_BTREE_NOERROR);
1155                                                bno_cur_lt = NULL;
1156                                                break;
1157                                        }
1158                                        /*
1159                                         * If we reach a big enough entry,
1160                                         * compare the two and pick the best.
1161                                         */
1162                                        if (ltlena >= args->minlen) {
1163                                                args->len = XFS_EXTLEN_MIN(
1164                                                        ltlena, args->maxlen);
1165                                                xfs_alloc_fix_len(args);
1166                                                rlen = args->len;
1167                                                ltdiff = xfs_alloc_compute_diff(
1168                                                        args->agbno, rlen,
1169                                                        args->alignment,
1170                                                        ltbno, ltlen, &ltnew);
1171                                                /*
1172                                                 * Left side is better.
1173                                                 */
1174                                                if (ltdiff < gtdiff) {
1175                                                        xfs_btree_del_cursor(
1176                                                                bno_cur_gt,
1177                                                                XFS_BTREE_NOERROR);
1178                                                        bno_cur_gt = NULL;
1179                                                }
1180                                                /*
1181                                                 * Right side is better.
1182                                                 */
1183                                                else {
1184                                                        xfs_btree_del_cursor(
1185                                                                bno_cur_lt,
1186                                                                XFS_BTREE_NOERROR);
1187                                                        bno_cur_lt = NULL;
1188                                                }
1189                                                break;
1190                                        }
1191                                        /*
1192                                         * Fell off the left end.
1193                                         */
1194                                        if ((error = xfs_alloc_decrement(
1195                                                        bno_cur_lt, 0, &i)))
1196                                                goto error0;
1197                                        if (!i) {
1198                                                xfs_btree_del_cursor(bno_cur_lt,
1199                                                        XFS_BTREE_NOERROR);
1200                                                bno_cur_lt = NULL;
1201                                                break;
1202                                        }
1203                                }
1204                        }
1205                        /*
1206                         * The right side is perfect, trash the left side.
1207                         */
1208                        else {
1209                                xfs_btree_del_cursor(bno_cur_lt,
1210                                        XFS_BTREE_NOERROR);
1211                                bno_cur_lt = NULL;
1212                        }
1213                }
1214        }
1215        /*
1216         * If we couldn't get anything, give up.
1217         */
1218        if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
1219                TRACE_ALLOC("neither", args);
1220                args->agbno = NULLAGBLOCK;
1221                return 0;
1222        }
1223        /*
1224         * At this point we have selected a freespace entry, either to the
1225         * left or to the right.  If it's on the right, copy all the
1226         * useful variables to the "left" set so we only have one
1227         * copy of this code.
1228         */
1229        if (bno_cur_gt) {
1230                bno_cur_lt = bno_cur_gt;
1231                bno_cur_gt = NULL;
1232                ltbno = gtbno;
1233                ltbnoa = gtbnoa;
1234                ltlen = gtlen;
1235                ltlena = gtlena;
1236                j = 1;
1237        } else
1238                j = 0;
1239        /*
1240         * Fix up the length and compute the useful address.
1241         */
1242        ltend = ltbno + ltlen;
1243        args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1244        xfs_alloc_fix_len(args);
1245        if (!xfs_alloc_fix_minleft(args)) {
1246                TRACE_ALLOC("nominleft", args);
1247                xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1248                xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1249                return 0;
1250        }
1251        rlen = args->len;
1252        (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment, ltbno,
1253                ltlen, &ltnew);
1254        ASSERT(ltnew >= ltbno);
1255        ASSERT(ltnew + rlen <= ltend);
1256        ASSERT(ltnew + rlen <= INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
1257                ARCH_CONVERT));
1258        args->agbno = ltnew;
1259        if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1260                        ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1261                goto error0;
1262        TRACE_ALLOC(j ? "gt" : "lt", args);
1263        xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1264        xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1265        return 0;
1266
1267 error0:
1268        TRACE_ALLOC("error", args);
1269        if (cnt_cur != NULL)
1270                xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1271        if (bno_cur_lt != NULL)
1272                xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1273        if (bno_cur_gt != NULL)
1274                xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1275        return error;
1276}
1277
1278/*
1279 * Allocate a variable extent anywhere in the allocation group agno.
1280 * Extent's length (returned in len) will be between minlen and maxlen,
1281 * and of the form k * prod + mod unless there's nothing that large.
1282 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1283 */
1284STATIC int                              /* error */
1285xfs_alloc_ag_vextent_size(
1286        xfs_alloc_arg_t *args)          /* allocation argument structure */
1287{
1288        xfs_btree_cur_t *bno_cur;       /* cursor for bno btree */
1289        xfs_btree_cur_t *cnt_cur;       /* cursor for cnt btree */
1290        int             error;          /* error result */
1291        xfs_agblock_t   fbno;           /* start of found freespace */
1292        xfs_extlen_t    flen;           /* length of found freespace */
1293#ifdef XFS_ALLOC_TRACE
1294        static char     fname[] = "xfs_alloc_ag_vextent_size";
1295#endif
1296        int             i;              /* temp status variable */
1297        xfs_agblock_t   rbno;           /* returned block number */
1298        xfs_extlen_t    rlen;           /* length of returned extent */
1299
1300        /*
1301         * Allocate and initialize a cursor for the by-size btree.
1302         */
1303        cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
1304                args->agno, XFS_BTNUM_CNT, NULL, 0);
1305        bno_cur = NULL;
1306        /*
1307         * Look for an entry >= maxlen+alignment-1 blocks.
1308         */
1309        if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1310                        args->maxlen + args->alignment - 1, &i)))
1311                goto error0;
1312        /*
1313         * If none, then pick up the last entry in the tree unless the
1314         * tree is empty.
1315         */
1316        if (!i) {
1317                if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &fbno,
1318                                &flen, &i)))
1319                        goto error0;
1320                if (i == 0 || flen == 0) {
1321                        xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1322                        TRACE_ALLOC("noentry", args);
1323                        return 0;
1324                }
1325                ASSERT(i == 1);
1326        }
1327        /*
1328         * There's a freespace as big as maxlen+alignment-1, get it.
1329         */
1330        else {
1331                if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i)))
1332                        goto error0;
1333                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1334        }
1335        /*
1336         * In the first case above, we got the last entry in the
1337         * by-size btree.  Now we check to see if the space hits maxlen
1338         * once aligned; if not, we search left for something better.
1339         * This can't happen in the second case above.
1340         */
1341        xfs_alloc_compute_aligned(fbno, flen, args->alignment, args->minlen,
1342                &rbno, &rlen);
1343        rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1344        XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1345                        (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1346        if (rlen < args->maxlen) {
1347                xfs_agblock_t   bestfbno;
1348                xfs_extlen_t    bestflen;
1349                xfs_agblock_t   bestrbno;
1350                xfs_extlen_t    bestrlen;
1351
1352                bestrlen = rlen;
1353                bestrbno = rbno;
1354                bestflen = flen;
1355                bestfbno = fbno;
1356                for (;;) {
1357                        if ((error = xfs_alloc_decrement(cnt_cur, 0, &i)))
1358                                goto error0;
1359                        if (i == 0)
1360                                break;
1361                        if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1362                                        &i)))
1363                                goto error0;
1364                        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1365                        if (flen < bestrlen)
1366                                break;
1367                        xfs_alloc_compute_aligned(fbno, flen, args->alignment,
1368                                args->minlen, &rbno, &rlen);
1369                        rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1370                        XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1371                                (rlen <= flen && rbno + rlen <= fbno + flen),
1372                                error0);
1373                        if (rlen > bestrlen) {
1374                                bestrlen = rlen;
1375                                bestrbno = rbno;
1376                                bestflen = flen;
1377                                bestfbno = fbno;
1378                                if (rlen == args->maxlen)
1379                                        break;
1380                        }
1381                }
1382                if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1383                                &i)))
1384                        goto error0;
1385                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1386                rlen = bestrlen;
1387                rbno = bestrbno;
1388                flen = bestflen;
1389                fbno = bestfbno;
1390        }
1391        args->wasfromfl = 0;
1392        /*
1393         * Fix up the length.
1394         */
1395        args->len = rlen;
1396        xfs_alloc_fix_len(args);
1397        if (rlen < args->minlen || !xfs_alloc_fix_minleft(args)) {
1398                xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1399                TRACE_ALLOC("nominleft", args);
1400                args->agbno = NULLAGBLOCK;
1401                return 0;
1402        }
1403        rlen = args->len;
1404        XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
1405        /*
1406         * Allocate and initialize a cursor for the by-block tree.
1407         */
1408        bno_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
1409                args->agno, XFS_BTNUM_BNO, NULL, 0);
1410        if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1411                        rbno, rlen, XFSA_FIXUP_CNT_OK)))
1412                goto error0;
1413        xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1414        xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1415        cnt_cur = bno_cur = NULL;
1416        args->len = rlen;
1417        args->agbno = rbno;
1418        XFS_WANT_CORRUPTED_GOTO(
1419                args->agbno + args->len <=
1420                        INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
1421                        ARCH_CONVERT),
1422                error0);
1423        TRACE_ALLOC("normal", args);
1424        return 0;
1425
1426error0:
1427        TRACE_ALLOC("error", args);
1428        if (cnt_cur)
1429                xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1430        if (bno_cur)
1431                xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1432        return error;
1433}
1434
1435/*
1436 * Deal with the case where only small freespaces remain.
1437 * Either return the contents of the last freespace record,
1438 * or allocate space from the freelist if there is nothing in the tree.
1439 */
1440STATIC int                      /* error */
1441xfs_alloc_ag_vextent_small(
1442        xfs_alloc_arg_t *args,  /* allocation argument structure */
1443        xfs_btree_cur_t *ccur,  /* by-size cursor */
1444        xfs_agblock_t   *fbnop, /* result block number */
1445        xfs_extlen_t    *flenp, /* result length */
1446        int             *stat)  /* status: 0-freelist, 1-normal/none */
1447{
1448        int             error;
1449        xfs_agblock_t   fbno;
1450        xfs_extlen_t    flen;
1451#ifdef XFS_ALLOC_TRACE
1452        static char     fname[] = "xfs_alloc_ag_vextent_small";
1453#endif
1454        int             i;
1455
1456        if ((error = xfs_alloc_decrement(ccur, 0, &i)))
1457                goto error0;
1458        if (i) {
1459                if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
1460                        goto error0;
1461                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1462        }
1463        /*
1464         * Nothing in the btree, try the freelist.  Make sure
1465         * to respect minleft even when pulling from the
1466         * freelist.
1467         */
1468        else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
1469                 (INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_flcount,
1470                        ARCH_CONVERT) > args->minleft)) {
1471                if ((error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno)))
1472                        goto error0;
1473                if (fbno != NULLAGBLOCK) {
1474                        if (args->userdata) {
1475                                xfs_buf_t       *bp;
1476
1477                                bp = xfs_btree_get_bufs(args->mp, args->tp,
1478                                        args->agno, fbno, 0);
1479                                xfs_trans_binval(args->tp, bp);
1480                        }
1481                        args->len = 1;
1482                        args->agbno = fbno;
1483                        XFS_WANT_CORRUPTED_GOTO(
1484                                args->agbno + args->len <=
1485                                INT_GET(XFS_BUF_TO_AGF(args->agbp)->agf_length,
1486                                        ARCH_CONVERT),
1487                                error0);
1488                        args->wasfromfl = 1;
1489                        TRACE_ALLOC("freelist", args);
1490                        *stat = 0;
1491                        return 0;
1492                }
1493                /*
1494                 * Nothing in the freelist.
1495                 */
1496                else
1497                        flen = 0;
1498        }
1499        /*
1500         * Can't allocate from the freelist for some reason.
1501         */
1502        else
1503                flen = 0;
1504        /*
1505         * Can't do the allocation, give up.
1506         */
1507        if (flen < args->minlen) {
1508                args->agbno = NULLAGBLOCK;
1509                TRACE_ALLOC("notenough", args);
1510                flen = 0;
1511        }
1512        *fbnop = fbno;
1513        *flenp = flen;
1514        *stat = 1;
1515        TRACE_ALLOC("normal", args);
1516        return 0;
1517
1518error0:
1519        TRACE_ALLOC("error", args);
1520        return error;
1521}
1522
1523/*
1524 * Free the extent starting at agno/bno for length.
1525 */
1526STATIC int                      /* error */
1527xfs_free_ag_extent(
1528        xfs_trans_t     *tp,    /* transaction pointer */
1529        xfs_buf_t       *agbp,  /* buffer for a.g. freelist header */
1530        xfs_agnumber_t  agno,   /* allocation group number */
1531        xfs_agblock_t   bno,    /* starting block number */
1532        xfs_extlen_t    len,    /* length of extent */
1533        int             isfl)   /* set if is freelist blocks - no sb acctg */
1534{
1535        xfs_btree_cur_t *bno_cur;       /* cursor for by-block btree */
1536        xfs_btree_cur_t *cnt_cur;       /* cursor for by-size btree */
1537        int             error;          /* error return value */
1538#ifdef XFS_ALLOC_TRACE
1539        static char     fname[] = "xfs_free_ag_extent";
1540#endif
1541        xfs_agblock_t   gtbno;          /* start of right neighbor block */
1542        xfs_extlen_t    gtlen;          /* length of right neighbor block */
1543        int             haveleft;       /* have a left neighbor block */
1544        int             haveright;      /* have a right neighbor block */
1545        int             i;              /* temp, result code */
1546        xfs_agblock_t   ltbno;          /* start of left neighbor block */
1547        xfs_extlen_t    ltlen;          /* length of left neighbor block */
1548        xfs_mount_t     *mp;            /* mount point struct for filesystem */
1549        xfs_agblock_t   nbno;           /* new starting block of freespace */
1550        xfs_extlen_t    nlen;           /* new length of freespace */
1551
1552        mp = tp->t_mountp;
1553        /*
1554         * Allocate and initialize a cursor for the by-block btree.
1555         */
1556        bno_cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO, NULL,
1557                0);
1558        cnt_cur = NULL;
1559        /*
1560         * Look for a neighboring block on the left (lower block numbers)
1561         * that is contiguous with this space.
1562         */
1563        if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1564                goto error0;
1565        if (haveleft) {
1566                /*
1567                 * There is a block to our left.
1568                 */
1569                if ((error = xfs_alloc_get_rec(bno_cur, &ltbno, &ltlen, &i)))
1570                        goto error0;
1571                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1572                /*
1573                 * It's not contiguous, though.
1574                 */
1575                if (ltbno + ltlen < bno)
1576                        haveleft = 0;
1577                else {
1578                        /*
1579                         * If this failure happens the request to free this
1580                         * space was invalid, it's (partly) already free.
1581                         * Very bad.
1582                         */
1583                        XFS_WANT_CORRUPTED_GOTO(ltbno + ltlen <= bno, error0);
1584                }
1585        }
1586        /*
1587         * Look for a neighboring block on the right (higher block numbers)
1588         * that is contiguous with this space.
1589         */
1590        if ((error = xfs_alloc_increment(bno_cur, 0, &haveright)))
1591                goto error0;
1592        if (haveright) {
1593                /*
1594                 * There is a block to our right.
1595                 */
1596                if ((error = xfs_alloc_get_rec(bno_cur, &gtbno, &gtlen, &i)))
1597                        goto error0;
1598                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1599                /*
1600                 * It's not contiguous, though.
1601                 */
1602                if (bno + len < gtbno)
1603                        haveright = 0;
1604                else {
1605                        /*
1606                         * If this failure happens the request to free this
1607                         * space was invalid, it's (partly) already free.
1608                         * Very bad.
1609                         */
1610                        XFS_WANT_CORRUPTED_GOTO(gtbno >= bno + len, error0);
1611                }
1612        }
1613        /*
1614         * Now allocate and initialize a cursor for the by-size tree.
1615         */
1616        cnt_cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT, NULL,
1617                0);
1618        /*
1619         * Have both left and right contiguous neighbors.
1620         * Merge all three into a single free block.
1621         */
1622        if (haveleft && haveright) {
1623                /*
1624                 * Delete the old by-size entry on the left.
1625                 */
1626                if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1627                        goto error0;
1628                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1629                if ((error = xfs_alloc_delete(cnt_cur, &i)))
1630                        goto error0;
1631                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1632                /*
1633                 * Delete the old by-size entry on the right.
1634                 */
1635                if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1636                        goto error0;
1637                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1638                if ((error = xfs_alloc_delete(cnt_cur, &i)))
1639                        goto error0;
1640                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1641                /*
1642                 * Delete the old by-block entry for the right block.
1643                 */
1644                if ((error = xfs_alloc_delete(bno_cur, &i)))
1645                        goto error0;
1646                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1647                /*
1648                 * Move the by-block cursor back to the left neighbor.
1649                 */
1650                if ((error = xfs_alloc_decrement(bno_cur, 0, &i)))
1651                        goto error0;
1652                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1653#ifdef DEBUG
1654                /*
1655                 * Check that this is the right record: delete didn't
1656                 * mangle the cursor.
1657                 */
1658                {
1659                        xfs_agblock_t   xxbno;
1660                        xfs_extlen_t    xxlen;
1661
1662                        if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1663                                        &i)))
1664                                goto error0;
1665                        XFS_WANT_CORRUPTED_GOTO(
1666                                i == 1 && xxbno == ltbno && xxlen == ltlen,
1667                                error0);
1668                }
1669#endif
1670                /*
1671                 * Update remaining by-block entry to the new, joined block.
1672                 */
1673                nbno = ltbno;
1674                nlen = len + ltlen + gtlen;
1675                if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1676                        goto error0;
1677        }
1678        /*
1679         * Have only a left contiguous neighbor.
1680         * Merge it together with the new freespace.
1681         */
1682        else if (haveleft) {
1683                /*
1684                 * Delete the old by-size entry on the left.
1685                 */
1686                if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1687                        goto error0;
1688                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1689                if ((error = xfs_alloc_delete(cnt_cur, &i)))
1690                        goto error0;
1691                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1692                /*
1693                 * Back up the by-block cursor to the left neighbor, and
1694                 * update its length.
1695                 */
1696                if ((error = xfs_alloc_decrement(bno_cur, 0, &i)))
1697                        goto error0;
1698                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1699                nbno = ltbno;
1700                nlen = len + ltlen;
1701                if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1702                        goto error0;
1703        }
1704        /*
1705         * Have only a right contiguous neighbor.
1706         * Merge it together with the new freespace.
1707         */
1708        else if (haveright) {
1709                /*
1710                 * Delete the old by-size entry on the right.
1711                 */
1712                if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1713                        goto error0;
1714                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1715                if ((error = xfs_alloc_delete(cnt_cur, &i)))
1716                        goto error0;
1717                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1718                /*
1719                 * Update the starting block and length of the right
1720                 * neighbor in the by-block tree.
1721                 */
1722                nbno = bno;
1723                nlen = len + gtlen;
1724                if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1725                        goto error0;
1726        }
1727        /*
1728         * No contiguous neighbors.
1729         * Insert the new freespace into the by-block tree.
1730         */
1731        else {
1732                nbno = bno;
1733                nlen = len;
1734                if ((error = xfs_alloc_insert(bno_cur, &i)))
1735                        goto error0;
1736                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1737        }
1738        xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1739        bno_cur = NULL;
1740        /*
1741         * In all cases we need to insert the new freespace in the by-size tree.
1742         */
1743        if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1744                goto error0;
1745        XFS_WANT_CORRUPTED_GOTO(i == 0, error0);
1746        if ((error = xfs_alloc_insert(cnt_cur, &i)))
1747                goto error0;
1748        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1749        xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1750        cnt_cur = NULL;
1751        /*
1752         * Update the freespace totals in the ag and superblock.
1753         */
1754        {
1755                xfs_agf_t       *agf;
1756                xfs_perag_t     *pag;           /* per allocation group data */
1757
1758                agf = XFS_BUF_TO_AGF(agbp);
1759                pag = &mp->m_perag[agno];
1760                INT_MOD(agf->agf_freeblks, ARCH_CONVERT, len);
1761                xfs_trans_agblocks_delta(tp, len);
1762                pag->pagf_freeblks += len;
1763                XFS_WANT_CORRUPTED_GOTO(
1764                        INT_GET(agf->agf_freeblks, ARCH_CONVERT)
1765                                <= INT_GET(agf->agf_length, ARCH_CONVERT),
1766                        error0);
1767                TRACE_MODAGF(NULL, agf, XFS_AGF_FREEBLKS);
1768                xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
1769                if (!isfl)
1770                        xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
1771                XFS_STATS_INC(xs_freex);
1772                XFS_STATS_ADD(xs_freeb, len);
1773        }
1774        TRACE_FREE(haveleft ?
1775                        (haveright ? "both" : "left") :
1776                        (haveright ? "right" : "none"),
1777                agno, bno, len, isfl);
1778
1779        /*
1780         * Since blocks move to the free list without the coordination
1781         * used in xfs_bmap_finish, we can't allow block to be available
1782         * for reallocation and non-transaction writing (user data)
1783         * until we know that the transaction that moved it to the free
1784         * list is permanently on disk.  We track the blocks by declaring
1785         * these blocks as "busy"; the busy list is maintained on a per-ag
1786         * basis and each transaction records which entries should be removed
1787         * when the iclog commits to disk.  If a busy block is allocated,
1788         * the iclog is pushed up to the LSN that freed the block.
1789         */
1790        xfs_alloc_mark_busy(tp, agno, bno, len);
1791        return 0;
1792
1793 error0:
1794        TRACE_FREE("error", agno, bno, len, isfl);
1795        if (bno_cur)
1796                xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1797        if (cnt_cur)
1798                xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1799        return error;
1800}
1801
1802/*
1803 * Visible (exported) allocation/free functions.
1804 * Some of these are used just by xfs_alloc_btree.c and this file.
1805 */
1806
1807/*
1808 * Compute and fill in value of m_ag_maxlevels.
1809 */
1810void
1811xfs_alloc_compute_maxlevels(
1812        xfs_mount_t     *mp)    /* file system mount structure */
1813{
1814        int             level;
1815        uint            maxblocks;
1816        uint            maxleafents;
1817        int             minleafrecs;
1818        int             minnoderecs;
1819
1820        maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
1821        minleafrecs = mp->m_alloc_mnr[0];
1822        minnoderecs = mp->m_alloc_mnr[1];
1823        maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1824        for (level = 1; maxblocks > 1; level++)
1825                maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1826        mp->m_ag_maxlevels = level;
1827}
1828
1829/*
1830 * Decide whether to use this allocation group for this allocation.
1831 * If so, fix up the btree freelist's size.
1832 */
1833STATIC int                      /* error */
1834xfs_alloc_fix_freelist(
1835        xfs_alloc_arg_t *args,  /* allocation argument structure */
1836        int             flags)  /* XFS_ALLOC_FLAG_... */
1837{
1838        xfs_buf_t       *agbp;  /* agf buffer pointer */
1839        xfs_agf_t       *agf;   /* a.g. freespace structure pointer */
1840        xfs_buf_t       *agflbp;/* agfl buffer pointer */
1841        xfs_agblock_t   bno;    /* freelist block */
1842        xfs_extlen_t    delta;  /* new blocks needed in freelist */
1843        int             error;  /* error result code */
1844        xfs_extlen_t    longest;/* longest extent in allocation group */
1845        xfs_mount_t     *mp;    /* file system mount point structure */
1846        xfs_extlen_t    need;   /* total blocks needed in freelist */
1847        xfs_perag_t     *pag;   /* per-ag information structure */
1848        xfs_alloc_arg_t targs;  /* local allocation arguments */
1849        xfs_trans_t     *tp;    /* transaction pointer */
1850
1851        mp = args->mp;
1852
1853        pag = args->pag;
1854        tp = args->tp;
1855        if (!pag->pagf_init) {
1856                if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1857                                &agbp)))
1858                        return error;
1859                if (!pag->pagf_init) {
1860                        args->agbp = NULL;
1861                        return 0;
1862                }
1863        } else
1864                agbp = NULL;
1865
1866        /* If this is a metadata prefered pag and we are user data
1867         * then try somewhere else if we are not being asked to
1868         * try harder at this point
1869         */
1870        if (pag->pagf_metadata && args->userdata && flags) {
1871                args->agbp = NULL;
1872                return 0;
1873        }
1874
1875        need = XFS_MIN_FREELIST_PAG(pag, mp);
1876        delta = need > pag->pagf_flcount ? need - pag->pagf_flcount : 0;
1877        /*
1878         * If it looks like there isn't a long enough extent, or enough
1879         * total blocks, reject it.
1880         */
1881        longest = (pag->pagf_longest > delta) ?
1882                (pag->pagf_longest - delta) :
1883                (pag->pagf_flcount > 0 || pag->pagf_longest > 0);
1884        if (args->minlen + args->alignment + args->minalignslop - 1 > longest ||
1885            (args->minleft &&
1886             (int)(pag->pagf_freeblks + pag->pagf_flcount -
1887                   need - args->total) <
1888             (int)args->minleft)) {
1889                if (agbp)
1890                        xfs_trans_brelse(tp, agbp);
1891                args->agbp = NULL;
1892                return 0;
1893        }
1894        /*
1895         * Get the a.g. freespace buffer.
1896         * Can fail if we're not blocking on locks, and it's held.
1897         */
1898        if (agbp == NULL) {
1899                if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1900                                &agbp)))
1901                        return error;
1902                if (agbp == NULL) {
1903                        args->agbp = NULL;
1904                        return 0;
1905                }
1906        }
1907        /*
1908         * Figure out how many blocks we should have in the freelist.
1909         */
1910        agf = XFS_BUF_TO_AGF(agbp);
1911        need = XFS_MIN_FREELIST(agf, mp);
1912        delta = need > INT_GET(agf->agf_flcount, ARCH_CONVERT) ?
1913                (need - INT_GET(agf->agf_flcount, ARCH_CONVERT)) : 0;
1914        /*
1915         * If there isn't enough total or single-extent, reject it.
1916         */
1917        longest = INT_GET(agf->agf_longest, ARCH_CONVERT);
1918        longest = (longest > delta) ? (longest - delta) :
1919                (INT_GET(agf->agf_flcount, ARCH_CONVERT) > 0 || longest > 0);
1920        if (args->minlen + args->alignment + args->minalignslop - 1 > longest ||
1921             (args->minleft &&
1922                (int)(INT_GET(agf->agf_freeblks, ARCH_CONVERT) +
1923                   INT_GET(agf->agf_flcount, ARCH_CONVERT) - need - args->total) <
1924             (int)args->minleft)) {
1925                xfs_trans_brelse(tp, agbp);
1926                args->agbp = NULL;
1927                return 0;
1928        }
1929        /*
1930         * Make the freelist shorter if it's too long.
1931         */
1932        while (INT_GET(agf->agf_flcount, ARCH_CONVERT) > need) {
1933                xfs_buf_t       *bp;
1934
1935                if ((error = xfs_alloc_get_freelist(tp, agbp, &bno)))
1936                        return error;
1937                if ((error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1)))
1938                        return error;
1939                bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
1940                xfs_trans_binval(tp, bp);
1941        }
1942        /*
1943         * Initialize the args structure.
1944         */
1945        targs.tp = tp;
1946        targs.mp = mp;
1947        targs.agbp = agbp;
1948        targs.agno = args->agno;
1949        targs.mod = targs.minleft = targs.wasdel = targs.userdata =
1950                targs.minalignslop = 0;
1951        targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
1952        targs.type = XFS_ALLOCTYPE_THIS_AG;
1953        targs.pag = pag;
1954        if ((error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp)))
1955                return error;
1956        /*
1957         * Make the freelist longer if it's too short.
1958         */
1959        while (INT_GET(agf->agf_flcount, ARCH_CONVERT) < need) {
1960                targs.agbno = 0;
1961                targs.maxlen = need - INT_GET(agf->agf_flcount, ARCH_CONVERT);
1962                /*
1963                 * Allocate as many blocks as possible at once.
1964                 */
1965                if ((error = xfs_alloc_ag_vextent(&targs)))
1966                        return error;
1967                /*
1968                 * Stop if we run out.  Won't happen if callers are obeying
1969                 * the restrictions correctly.  Can happen for free calls
1970                 * on a completely full ag.
1971                 */
1972                if (targs.agbno == NULLAGBLOCK)
1973                        break;
1974                /*
1975                 * Put each allocated block on the list.
1976                 */
1977                for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
1978                        if ((error = xfs_alloc_put_freelist(tp, agbp, agflbp,
1979                                        bno)))
1980                                return error;
1981                }
1982        }
1983        args->agbp = agbp;
1984        return 0;
1985}
1986
1987/*
1988 * Get a block from the freelist.
1989 * Returns with the buffer for the block gotten.
1990 */
1991int                             /* error */
1992xfs_alloc_get_freelist(
1993        xfs_trans_t     *tp,    /* transaction pointer */
1994        xfs_buf_t       *agbp,  /* buffer containing the agf structure */
1995        xfs_agblock_t   *bnop)  /* block address retrieved from freelist */
1996{
1997        xfs_agf_t       *agf;   /* a.g. freespace structure */
1998        xfs_agfl_t      *agfl;  /* a.g. freelist structure */
1999        xfs_buf_t       *agflbp;/* buffer for a.g. freelist structure */
2000        xfs_agblock_t   bno;    /* block number returned */
2001        int             error;
2002#ifdef XFS_ALLOC_TRACE
2003        static char     fname[] = "xfs_alloc_get_freelist";
2004#endif
2005        xfs_mount_t     *mp;    /* mount structure */
2006        xfs_perag_t     *pag;   /* per allocation group data */
2007
2008        agf = XFS_BUF_TO_AGF(agbp);
2009        /*
2010         * Freelist is empty, give up.
2011         */
2012        if (INT_ISZERO(agf->agf_flcount, ARCH_CONVERT)) {
2013                *bnop = NULLAGBLOCK;
2014                return 0;
2015        }
2016        /*
2017         * Read the array of free blocks.
2018         */
2019        mp = tp->t_mountp;
2020        if ((error = xfs_alloc_read_agfl(mp, tp,
2021                        INT_GET(agf->agf_seqno, ARCH_CONVERT), &agflbp)))
2022                return error;
2023        agfl = XFS_BUF_TO_AGFL(agflbp);
2024        /*
2025         * Get the block number and update the data structures.
2026         */
2027        bno = INT_GET(agfl->agfl_bno[INT_GET(agf->agf_flfirst, ARCH_CONVERT)], ARCH_CONVERT);
2028        INT_MOD(agf->agf_flfirst, ARCH_CONVERT, 1);
2029        xfs_trans_brelse(tp, agflbp);
2030        if (INT_GET(agf->agf_flfirst, ARCH_CONVERT) == XFS_AGFL_SIZE(mp))
2031                INT_ZERO(agf->agf_flfirst, ARCH_CONVERT);
2032        pag = &mp->m_perag[INT_GET(agf->agf_seqno, ARCH_CONVERT)];
2033        INT_MOD(agf->agf_flcount, ARCH_CONVERT, -1);
2034        xfs_trans_agflist_delta(tp, -1);
2035        pag->pagf_flcount--;
2036        TRACE_MODAGF(NULL, agf, XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
2037        xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
2038        *bnop = bno;
2039
2040        /*
2041         * As blocks are freed, they are added to the per-ag busy list
2042         * and remain there until the freeing transaction is committed to
2043         * disk.  Now that we have allocated blocks, this list must be
2044         * searched to see if a block is being reused.  If one is, then
2045         * the freeing transaction must be pushed to disk NOW by forcing
2046         * to disk all iclogs up that transaction's LSN.
2047         */
2048        xfs_alloc_search_busy(tp, INT_GET(agf->agf_seqno, ARCH_CONVERT), bno, 1);
2049        return 0;
2050}
2051
2052/*
2053 * Log the given fields from the agf structure.
2054 */
2055void
2056xfs_alloc_log_agf(
2057        xfs_trans_t     *tp,    /* transaction pointer */
2058        xfs_buf_t       *bp,    /* buffer for a.g. freelist header */
2059        int             fields) /* mask of fields to be logged (XFS_AGF_...) */
2060{
2061        int     first;          /* first byte offset */
2062        int     last;           /* last byte offset */
2063        static const short      offsets[] = {
2064                offsetof(xfs_agf_t, agf_magicnum),
2065                offsetof(xfs_agf_t, agf_versionnum),
2066                offsetof(xfs_agf_t, agf_seqno),
2067                offsetof(xfs_agf_t, agf_length),
2068                offsetof(xfs_agf_t, agf_roots[0]),
2069                offsetof(xfs_agf_t, agf_levels[0]),
2070                offsetof(xfs_agf_t, agf_flfirst),
2071                offsetof(xfs_agf_t, agf_fllast),
2072                offsetof(xfs_agf_t, agf_flcount),
2073                offsetof(xfs_agf_t, agf_freeblks),
2074                offsetof(xfs_agf_t, agf_longest),
2075                sizeof(xfs_agf_t)
2076        };
2077
2078        xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2079        xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2080}
2081
2082/*
2083 * Interface for inode allocation to force the pag data to be initialized.
2084 */
2085int                                     /* error */
2086xfs_alloc_pagf_init(
2087        xfs_mount_t             *mp,    /* file system mount structure */
2088        xfs_trans_t             *tp,    /* transaction pointer */
2089        xfs_agnumber_t          agno,   /* allocation group number */
2090        int                     flags)  /* XFS_ALLOC_FLAGS_... */
2091{
2092        xfs_buf_t               *bp;
2093        int                     error;
2094
2095        if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2096                return error;
2097        if (bp)
2098                xfs_trans_brelse(tp, bp);
2099        return 0;
2100}
2101
2102/*
2103 * Put the block on the freelist for the allocation group.
2104 */
2105int                                     /* error */
2106xfs_alloc_put_freelist(
2107        xfs_trans_t             *tp,    /* transaction pointer */
2108        xfs_buf_t               *agbp,  /* buffer for a.g. freelist header */
2109        xfs_buf_t               *agflbp,/* buffer for a.g. free block array */
2110        xfs_agblock_t           bno)    /* block being freed */
2111{
2112        xfs_agf_t               *agf;   /* a.g. freespace structure */
2113        xfs_agfl_t              *agfl;  /* a.g. free block array */
2114        xfs_agblock_t           *blockp;/* pointer to array entry */
2115        int                     error;
2116#ifdef XFS_ALLOC_TRACE
2117        static char             fname[] = "xfs_alloc_put_freelist";
2118#endif
2119        xfs_mount_t             *mp;    /* mount structure */
2120        xfs_perag_t             *pag;   /* per allocation group data */
2121
2122        agf = XFS_BUF_TO_AGF(agbp);
2123        mp = tp->t_mountp;
2124
2125        if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
2126                        INT_GET(agf->agf_seqno, ARCH_CONVERT), &agflbp)))
2127                return error;
2128        agfl = XFS_BUF_TO_AGFL(agflbp);
2129        INT_MOD(agf->agf_fllast, ARCH_CONVERT, 1);
2130        if (INT_GET(agf->agf_fllast, ARCH_CONVERT) == XFS_AGFL_SIZE(mp))
2131                INT_ZERO(agf->agf_fllast, ARCH_CONVERT);
2132        pag = &mp->m_perag[INT_GET(agf->agf_seqno, ARCH_CONVERT)];
2133        INT_MOD(agf->agf_flcount, ARCH_CONVERT, 1);
2134        xfs_trans_agflist_delta(tp, 1);
2135        pag->pagf_flcount++;
2136        ASSERT(INT_GET(agf->agf_flcount, ARCH_CONVERT) <= XFS_AGFL_SIZE(mp));
2137        blockp = &agfl->agfl_bno[INT_GET(agf->agf_fllast, ARCH_CONVERT)];
2138        INT_SET(*blockp, ARCH_CONVERT, bno);
2139        TRACE_MODAGF(NULL, agf, XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
2140        xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
2141        xfs_trans_log_buf(tp, agflbp,
2142                (int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl),
2143                (int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl +
2144                        sizeof(xfs_agblock_t) - 1));
2145        return 0;
2146}
2147
2148/*
2149 * Read in the allocation group header (free/alloc section).
2150 */
2151int                                     /* error */
2152xfs_alloc_read_agf(
2153        xfs_mount_t     *mp,            /* mount point structure */
2154        xfs_trans_t     *tp,            /* transaction pointer */
2155        xfs_agnumber_t  agno,           /* allocation group number */
2156        int             flags,          /* XFS_ALLOC_FLAG_... */
2157        xfs_buf_t       **bpp)          /* buffer for the ag freelist header */
2158{
2159        xfs_agf_t       *agf;           /* ag freelist header */
2160        int             agf_ok;         /* set if agf is consistent */
2161        xfs_buf_t       *bp;            /* return value */
2162        xfs_perag_t     *pag;           /* per allocation group data */
2163        int             error;
2164
2165        ASSERT(agno != NULLAGNUMBER);
2166        error = xfs_trans_read_buf(
2167                        mp, tp, mp->m_ddev_targp,
2168                        XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
2169                        XFS_FSS_TO_BB(mp, 1),
2170                        (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XFS_BUF_TRYLOCK : 0U,
2171                        &bp);
2172        if (error)
2173                return error;
2174        ASSERT(!bp || !XFS_BUF_GETERROR(bp));
2175        if (!bp) {
2176                *bpp = NULL;
2177                return 0;
2178        }
2179        /*
2180         * Validate the magic number of the agf block.
2181         */
2182        agf = XFS_BUF_TO_AGF(bp);
2183        agf_ok =
2184                INT_GET(agf->agf_magicnum, ARCH_CONVERT) == XFS_AGF_MAGIC &&
2185                XFS_AGF_GOOD_VERSION(
2186                        INT_GET(agf->agf_versionnum, ARCH_CONVERT)) &&
2187                INT_GET(agf->agf_freeblks, ARCH_CONVERT) <=
2188                                INT_GET(agf->agf_length, ARCH_CONVERT) &&
2189                INT_GET(agf->agf_flfirst, ARCH_CONVERT) < XFS_AGFL_SIZE(mp) &&
2190                INT_GET(agf->agf_fllast,  ARCH_CONVERT) < XFS_AGFL_SIZE(mp) &&
2191                INT_GET(agf->agf_flcount, ARCH_CONVERT) <= XFS_AGFL_SIZE(mp);
2192        if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
2193                        XFS_RANDOM_ALLOC_READ_AGF))) {
2194                XFS_CORRUPTION_ERROR("xfs_alloc_read_agf",
2195                                     XFS_ERRLEVEL_LOW, mp, agf);
2196                xfs_trans_brelse(tp, bp);
2197                return XFS_ERROR(EFSCORRUPTED);
2198        }
2199        pag = &mp->m_perag[agno];
2200        if (!pag->pagf_init) {
2201                pag->pagf_freeblks = INT_GET(agf->agf_freeblks, ARCH_CONVERT);
2202                pag->pagf_flcount = INT_GET(agf->agf_flcount, ARCH_CONVERT);
2203                pag->pagf_longest = INT_GET(agf->agf_longest, ARCH_CONVERT);
2204                pag->pagf_levels[XFS_BTNUM_BNOi] =
2205                        INT_GET(agf->agf_levels[XFS_BTNUM_BNOi], ARCH_CONVERT);
2206                pag->pagf_levels[XFS_BTNUM_CNTi] =
2207                        INT_GET(agf->agf_levels[XFS_BTNUM_CNTi], ARCH_CONVERT);
2208                spinlock_init(&pag->pagb_lock, "xfspagb");
2209                pag->pagb_list = kmem_zalloc(XFS_PAGB_NUM_SLOTS *
2210                                        sizeof(xfs_perag_busy_t), KM_SLEEP);
2211                pag->pagf_init = 1;
2212        }
2213#ifdef DEBUG
2214        else if (!XFS_FORCED_SHUTDOWN(mp)) {
2215                ASSERT(pag->pagf_freeblks == INT_GET(agf->agf_freeblks, ARCH_CONVERT));
2216                ASSERT(pag->pagf_flcount == INT_GET(agf->agf_flcount, ARCH_CONVERT));
2217                ASSERT(pag->pagf_longest == INT_GET(agf->agf_longest, ARCH_CONVERT));
2218                ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
2219                       INT_GET(agf->agf_levels[XFS_BTNUM_BNOi], ARCH_CONVERT));
2220                ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
2221                       INT_GET(agf->agf_levels[XFS_BTNUM_CNTi], ARCH_CONVERT));
2222        }
2223#endif
2224        XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGF, XFS_AGF_REF);
2225        *bpp = bp;
2226        return 0;
2227}
2228
2229/*
2230 * Allocate an extent (variable-size).
2231 * Depending on the allocation type, we either look in a single allocation
2232 * group or loop over the allocation groups to find the result.
2233 */
2234int                             /* error */
2235xfs_alloc_vextent(
2236        xfs_alloc_arg_t *args)  /* allocation argument structure */
2237{
2238        xfs_agblock_t   agsize; /* allocation group size */
2239        int             error;
2240        int             flags;  /* XFS_ALLOC_FLAG_... locking flags */
2241#ifdef XFS_ALLOC_TRACE
2242        static char     fname[] = "xfs_alloc_vextent";
2243#endif
2244        xfs_extlen_t    minleft;/* minimum left value, temp copy */
2245        xfs_mount_t     *mp;    /* mount structure pointer */
2246        xfs_agnumber_t  sagno;  /* starting allocation group number */
2247        xfs_alloctype_t type;   /* input allocation type */
2248        int             bump_rotor = 0;
2249        int             no_min = 0;
2250        xfs_agnumber_t  rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2251
2252        mp = args->mp;
2253        type = args->otype = args->type;
2254        args->agbno = NULLAGBLOCK;
2255        /*
2256         * Just fix this up, for the case where the last a.g. is shorter
2257         * (or there's only one a.g.) and the caller couldn't easily figure
2258         * that out (xfs_bmap_alloc).
2259         */
2260        agsize = mp->m_sb.sb_agblocks;
2261        if (args->maxlen > agsize)
2262                args->maxlen = agsize;
2263        if (args->alignment == 0)
2264                args->alignment = 1;
2265        ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2266        ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2267        ASSERT(args->minlen <= args->maxlen);
2268        ASSERT(args->minlen <= agsize);
2269        ASSERT(args->mod < args->prod);
2270        if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2271            XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2272            args->minlen > args->maxlen || args->minlen > agsize ||
2273            args->mod >= args->prod) {
2274                args->fsbno = NULLFSBLOCK;
2275                TRACE_ALLOC("badargs", args);
2276                return 0;
2277        }
2278        minleft = args->minleft;
2279
2280        switch (type) {
2281        case XFS_ALLOCTYPE_THIS_AG:
2282        case XFS_ALLOCTYPE_NEAR_BNO:
2283        case XFS_ALLOCTYPE_THIS_BNO:
2284                /*
2285                 * These three force us into a single a.g.
2286                 */
2287                args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2288                down_read(&mp->m_peraglock);
2289                args->pag = &mp->m_perag[args->agno];
2290                args->minleft = 0;
2291                error = xfs_alloc_fix_freelist(args, 0);
2292                args->minleft = minleft;
2293                if (error) {
2294                        TRACE_ALLOC("nofix", args);
2295                        goto error0;
2296                }
2297                if (!args->agbp) {
2298                        up_read(&mp->m_peraglock);
2299                        TRACE_ALLOC("noagbp", args);
2300                        break;
2301                }
2302                args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2303                if ((error = xfs_alloc_ag_vextent(args)))
2304                        goto error0;
2305                up_read(&mp->m_peraglock);
2306                break;
2307        case XFS_ALLOCTYPE_START_BNO:
2308                /*
2309                 * Try near allocation first, then anywhere-in-ag after
2310                 * the first a.g. fails.
2311                 */
2312                if ((args->userdata  == XFS_ALLOC_INITIAL_USER_DATA) &&
2313                    (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2314                        args->fsbno = XFS_AGB_TO_FSB(mp,
2315                                        ((mp->m_agfrotor / rotorstep) %
2316                                        mp->m_sb.sb_agcount), 0);
2317                        bump_rotor = 1;
2318                }
2319                args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2320                args->type = XFS_ALLOCTYPE_NEAR_BNO;
2321                /* FALLTHROUGH */
2322        case XFS_ALLOCTYPE_ANY_AG:
2323        case XFS_ALLOCTYPE_START_AG:
2324        case XFS_ALLOCTYPE_FIRST_AG:
2325                /*
2326                 * Rotate through the allocation groups looking for a winner.
2327                 */
2328                if (type == XFS_ALLOCTYPE_ANY_AG) {
2329                        /*
2330                         * Start with the last place we left off.
2331                         */
2332                        args->agno = sagno = (mp->m_agfrotor / rotorstep) %
2333                                        mp->m_sb.sb_agcount;
2334                        args->type = XFS_ALLOCTYPE_THIS_AG;
2335                        flags = XFS_ALLOC_FLAG_TRYLOCK;
2336                } else if (type == XFS_ALLOCTYPE_FIRST_AG) {
2337                        /*
2338                         * Start with allocation group given by bno.
2339                         */
2340                        args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2341                        args->type = XFS_ALLOCTYPE_THIS_AG;
2342                        sagno = 0;
2343                        flags = 0;
2344                } else {
2345                        if (type == XFS_ALLOCTYPE_START_AG)
2346                                args->type = XFS_ALLOCTYPE_THIS_AG;
2347                        /*
2348                         * Start with the given allocation group.
2349                         */
2350                        args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2351                        flags = XFS_ALLOC_FLAG_TRYLOCK;
2352                }
2353                /*
2354                 * Loop over allocation groups twice; first time with
2355                 * trylock set, second time without.
2356                 */
2357                down_read(&mp->m_peraglock);
2358                for (;;) {
2359                        args->pag = &mp->m_perag[args->agno];
2360                        if (no_min) args->minleft = 0;
2361                        error = xfs_alloc_fix_freelist(args, flags);
2362                        args->minleft = minleft;
2363                        if (error) {
2364                                TRACE_ALLOC("nofix", args);
2365                                goto error0;
2366                        }
2367                        /*
2368                         * If we get a buffer back then the allocation will fly.
2369                         */
2370                        if (args->agbp) {
2371                                if ((error = xfs_alloc_ag_vextent(args)))
2372                                        goto error0;
2373                                break;
2374                        }
2375                        TRACE_ALLOC("loopfailed", args);
2376                        /*
2377                         * Didn't work, figure out the next iteration.
2378                         */
2379                        if (args->agno == sagno &&
2380                            type == XFS_ALLOCTYPE_START_BNO)
2381                                args->type = XFS_ALLOCTYPE_THIS_AG;
2382                        if (++(args->agno) == mp->m_sb.sb_agcount)
2383                                args->agno = 0;
2384                        /*
2385                         * Reached the starting a.g., must either be done
2386                         * or switch to non-trylock mode.
2387                         */
2388                        if (args->agno == sagno) {
2389                                if (no_min == 1) {
2390                                        args->agbno = NULLAGBLOCK;
2391                                        TRACE_ALLOC("allfailed", args);
2392                                        break;
2393                                }
2394                                if (flags == 0) {
2395                                        no_min = 1;
2396                                } else {
2397                                        flags = 0;
2398                                        if (type == XFS_ALLOCTYPE_START_BNO) {
2399                                                args->agbno = XFS_FSB_TO_AGBNO(mp,
2400                                                        args->fsbno);
2401                                                args->type = XFS_ALLOCTYPE_NEAR_BNO;
2402                                        }
2403                                }
2404                        }
2405                }
2406                up_read(&mp->m_peraglock);
2407                if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) {
2408                        if (args->agno == sagno)
2409                                mp->m_agfrotor = (mp->m_agfrotor + 1) %
2410                                        (mp->m_sb.sb_agcount * rotorstep);
2411                        else
2412                                mp->m_agfrotor = (args->agno * rotorstep + 1) %
2413                                        (mp->m_sb.sb_agcount * rotorstep);
2414                }
2415                break;
2416        default:
2417                ASSERT(0);
2418                /* NOTREACHED */
2419        }
2420        if (args->agbno == NULLAGBLOCK)
2421                args->fsbno = NULLFSBLOCK;
2422        else {
2423                args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2424#ifdef DEBUG
2425                ASSERT(args->len >= args->minlen);
2426                ASSERT(args->len <= args->maxlen);
2427                ASSERT(args->agbno % args->alignment == 0);
2428                XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2429                        args->len);
2430#endif
2431        }
2432        return 0;
2433error0:
2434        up_read(&mp->m_peraglock);
2435        return error;
2436}
2437
2438/*
2439 * Free an extent.
2440 * Just break up the extent address and hand off to xfs_free_ag_extent
2441 * after fixing up the freelist.
2442 */
2443int                             /* error */
2444xfs_free_extent(
2445        xfs_trans_t     *tp,    /* transaction pointer */
2446        xfs_fsblock_t   bno,    /* starting block number of extent */
2447        xfs_extlen_t    len)    /* length of extent */
2448{
2449#ifdef DEBUG
2450        xfs_agf_t       *agf;   /* a.g. freespace header */
2451#endif
2452        xfs_alloc_arg_t args;   /* allocation argument structure */
2453        int             error;
2454
2455        ASSERT(len != 0);
2456        args.tp = tp;
2457        args.mp = tp->t_mountp;
2458        args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
2459        ASSERT(args.agno < args.mp->m_sb.sb_agcount);
2460        args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
2461        args.alignment = 1;
2462        args.minlen = args.minleft = args.minalignslop = 0;
2463        down_read(&args.mp->m_peraglock);
2464        args.pag = &args.mp->m_perag[args.agno];
2465        if ((error = xfs_alloc_fix_freelist(&args, 0)))
2466                goto error0;
2467#ifdef DEBUG
2468        ASSERT(args.agbp != NULL);
2469        agf = XFS_BUF_TO_AGF(args.agbp);
2470        ASSERT(args.agbno + len <= INT_GET(agf->agf_length, ARCH_CONVERT));
2471#endif
2472        error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno,
2473                len, 0);
2474error0:
2475        up_read(&args.mp->m_peraglock);
2476        return error;
2477}
2478
2479
2480/*
2481 * AG Busy list management
2482 * The busy list contains block ranges that have been freed but whose
2483 * transacations have not yet hit disk.  If any block listed in a busy
2484 * list is reused, the transaction that freed it must be forced to disk
2485 * before continuing to use the block.
2486 *
2487 * xfs_alloc_mark_busy - add to the per-ag busy list
2488 * xfs_alloc_clear_busy - remove an item from the per-ag busy list
2489 */
2490void
2491xfs_alloc_mark_busy(xfs_trans_t *tp,
2492                    xfs_agnumber_t agno,
2493                    xfs_agblock_t bno,
2494                    xfs_extlen_t len)
2495{
2496        xfs_mount_t             *mp;
2497        xfs_perag_busy_t        *bsy;
2498        int                     n;
2499        SPLDECL(s);
2500
2501        mp = tp->t_mountp;
2502        s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
2503
2504        /* search pagb_list for an open slot */
2505        for (bsy = mp->m_perag[agno].pagb_list, n = 0;
2506             n < XFS_PAGB_NUM_SLOTS;
2507             bsy++, n++) {
2508                if (bsy->busy_tp == NULL) {
2509                        break;
2510                }
2511        }
2512
2513        if (n < XFS_PAGB_NUM_SLOTS) {
2514                bsy = &mp->m_perag[agno].pagb_list[n];
2515                mp->m_perag[agno].pagb_count++;
2516                TRACE_BUSY("xfs_alloc_mark_busy", "got", agno, bno, len, n, tp);
2517                bsy->busy_start = bno;
2518                bsy->busy_length = len;
2519                bsy->busy_tp = tp;
2520                xfs_trans_add_busy(tp, agno, n);
2521        } else {
2522                TRACE_BUSY("xfs_alloc_mark_busy", "FULL", agno, bno, len, -1, tp);
2523                /*
2524                 * The busy list is full!  Since it is now not possible to
2525                 * track the free block, make this a synchronous transaction
2526                 * to insure that the block is not reused before this
2527                 * transaction commits.
2528                 */
2529                xfs_trans_set_sync(tp);
2530        }
2531
2532        mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
2533}
2534
2535void
2536xfs_alloc_clear_busy(xfs_trans_t *tp,
2537                     xfs_agnumber_t agno,
2538                     int idx)
2539{
2540        xfs_mount_t             *mp;
2541        xfs_perag_busy_t        *list;
2542        SPLDECL(s);
2543
2544        mp = tp->t_mountp;
2545
2546        s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
2547        list = mp->m_perag[agno].pagb_list;
2548
2549        ASSERT(idx < XFS_PAGB_NUM_SLOTS);
2550        if (list[idx].busy_tp == tp) {
2551                TRACE_UNBUSY("xfs_alloc_clear_busy", "found", agno, idx, tp);
2552                list[idx].busy_tp = NULL;
2553                mp->m_perag[agno].pagb_count--;
2554        } else {
2555                TRACE_UNBUSY("xfs_alloc_clear_busy", "missing", agno, idx, tp);
2556        }
2557
2558        mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
2559}
2560
2561
2562/*
2563 * returns non-zero if any of (agno,bno):len is in a busy list
2564 */
2565int
2566xfs_alloc_search_busy(xfs_trans_t *tp,
2567                    xfs_agnumber_t agno,
2568                    xfs_agblock_t bno,
2569                    xfs_extlen_t len)
2570{
2571        xfs_mount_t             *mp;
2572        xfs_perag_busy_t        *bsy;
2573        int                     n;
2574        xfs_agblock_t           uend, bend;
2575        xfs_lsn_t               lsn;
2576        int                     cnt;
2577        SPLDECL(s);
2578
2579        mp = tp->t_mountp;
2580
2581        s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
2582        cnt = mp->m_perag[agno].pagb_count;
2583
2584        uend = bno + len - 1;
2585
2586        /* search pagb_list for this slot, skipping open slots */
2587        for (bsy = mp->m_perag[agno].pagb_list, n = 0;
2588             cnt; bsy++, n++) {
2589
2590                /*
2591                 * (start1,length1) within (start2, length2)
2592                 */
2593                if (bsy->busy_tp != NULL) {
2594                        bend = bsy->busy_start + bsy->busy_length - 1;
2595                        if ((bno > bend) ||
2596                            (uend < bsy->busy_start)) {
2597                                cnt--;
2598                        } else {
2599                                TRACE_BUSYSEARCH("xfs_alloc_search_busy",
2600                                                 "found1", agno, bno, len, n,
2601                                                 tp);
2602                                break;
2603                        }
2604                }
2605        }
2606
2607        /*
2608         * If a block was found, force the log through the LSN of the
2609         * transaction that freed the block
2610         */
2611        if (cnt) {
2612                TRACE_BUSYSEARCH("xfs_alloc_search_busy", "found", agno, bno, len, n, tp);
2613                lsn = bsy->busy_tp->t_commit_lsn;
2614                mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
2615                xfs_log_force(mp, lsn, XFS_LOG_FORCE|XFS_LOG_SYNC);
2616        } else {
2617                TRACE_BUSYSEARCH("xfs_alloc_search_busy", "not-found", agno, bno, len, n, tp);
2618                n = -1;
2619                mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
2620        }
2621
2622        return n;
2623}
2624