linux/fs/xfs/libxfs/xfs_bmap_btree.c
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   1/*
   2 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#include "xfs.h"
  19#include "xfs_fs.h"
  20#include "xfs_shared.h"
  21#include "xfs_format.h"
  22#include "xfs_log_format.h"
  23#include "xfs_trans_resv.h"
  24#include "xfs_bit.h"
  25#include "xfs_mount.h"
  26#include "xfs_inode.h"
  27#include "xfs_trans.h"
  28#include "xfs_inode_item.h"
  29#include "xfs_alloc.h"
  30#include "xfs_btree.h"
  31#include "xfs_bmap_btree.h"
  32#include "xfs_bmap.h"
  33#include "xfs_error.h"
  34#include "xfs_quota.h"
  35#include "xfs_trace.h"
  36#include "xfs_cksum.h"
  37
  38/*
  39 * Determine the extent state.
  40 */
  41/* ARGSUSED */
  42STATIC xfs_exntst_t
  43xfs_extent_state(
  44        xfs_filblks_t           blks,
  45        int                     extent_flag)
  46{
  47        if (extent_flag) {
  48                ASSERT(blks != 0);      /* saved for DMIG */
  49                return XFS_EXT_UNWRITTEN;
  50        }
  51        return XFS_EXT_NORM;
  52}
  53
  54/*
  55 * Convert on-disk form of btree root to in-memory form.
  56 */
  57void
  58xfs_bmdr_to_bmbt(
  59        struct xfs_inode        *ip,
  60        xfs_bmdr_block_t        *dblock,
  61        int                     dblocklen,
  62        struct xfs_btree_block  *rblock,
  63        int                     rblocklen)
  64{
  65        struct xfs_mount        *mp = ip->i_mount;
  66        int                     dmxr;
  67        xfs_bmbt_key_t          *fkp;
  68        __be64                  *fpp;
  69        xfs_bmbt_key_t          *tkp;
  70        __be64                  *tpp;
  71
  72        if (xfs_sb_version_hascrc(&mp->m_sb))
  73                xfs_btree_init_block_int(mp, rblock, XFS_BUF_DADDR_NULL,
  74                                 XFS_BMAP_CRC_MAGIC, 0, 0, ip->i_ino,
  75                                 XFS_BTREE_LONG_PTRS | XFS_BTREE_CRC_BLOCKS);
  76        else
  77                xfs_btree_init_block_int(mp, rblock, XFS_BUF_DADDR_NULL,
  78                                 XFS_BMAP_MAGIC, 0, 0, ip->i_ino,
  79                                 XFS_BTREE_LONG_PTRS);
  80
  81        rblock->bb_level = dblock->bb_level;
  82        ASSERT(be16_to_cpu(rblock->bb_level) > 0);
  83        rblock->bb_numrecs = dblock->bb_numrecs;
  84        dmxr = xfs_bmdr_maxrecs(dblocklen, 0);
  85        fkp = XFS_BMDR_KEY_ADDR(dblock, 1);
  86        tkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
  87        fpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
  88        tpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
  89        dmxr = be16_to_cpu(dblock->bb_numrecs);
  90        memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
  91        memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
  92}
  93
  94/*
  95 * Convert a compressed bmap extent record to an uncompressed form.
  96 * This code must be in sync with the routines xfs_bmbt_get_startoff,
  97 * xfs_bmbt_get_startblock, xfs_bmbt_get_blockcount and xfs_bmbt_get_state.
  98 */
  99STATIC void
 100__xfs_bmbt_get_all(
 101                __uint64_t l0,
 102                __uint64_t l1,
 103                xfs_bmbt_irec_t *s)
 104{
 105        int     ext_flag;
 106        xfs_exntst_t st;
 107
 108        ext_flag = (int)(l0 >> (64 - BMBT_EXNTFLAG_BITLEN));
 109        s->br_startoff = ((xfs_fileoff_t)l0 &
 110                           xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
 111        s->br_startblock = (((xfs_fsblock_t)l0 & xfs_mask64lo(9)) << 43) |
 112                           (((xfs_fsblock_t)l1) >> 21);
 113        s->br_blockcount = (xfs_filblks_t)(l1 & xfs_mask64lo(21));
 114        /* This is xfs_extent_state() in-line */
 115        if (ext_flag) {
 116                ASSERT(s->br_blockcount != 0);  /* saved for DMIG */
 117                st = XFS_EXT_UNWRITTEN;
 118        } else
 119                st = XFS_EXT_NORM;
 120        s->br_state = st;
 121}
 122
 123void
 124xfs_bmbt_get_all(
 125        xfs_bmbt_rec_host_t *r,
 126        xfs_bmbt_irec_t *s)
 127{
 128        __xfs_bmbt_get_all(r->l0, r->l1, s);
 129}
 130
 131/*
 132 * Extract the blockcount field from an in memory bmap extent record.
 133 */
 134xfs_filblks_t
 135xfs_bmbt_get_blockcount(
 136        xfs_bmbt_rec_host_t     *r)
 137{
 138        return (xfs_filblks_t)(r->l1 & xfs_mask64lo(21));
 139}
 140
 141/*
 142 * Extract the startblock field from an in memory bmap extent record.
 143 */
 144xfs_fsblock_t
 145xfs_bmbt_get_startblock(
 146        xfs_bmbt_rec_host_t     *r)
 147{
 148        return (((xfs_fsblock_t)r->l0 & xfs_mask64lo(9)) << 43) |
 149               (((xfs_fsblock_t)r->l1) >> 21);
 150}
 151
 152/*
 153 * Extract the startoff field from an in memory bmap extent record.
 154 */
 155xfs_fileoff_t
 156xfs_bmbt_get_startoff(
 157        xfs_bmbt_rec_host_t     *r)
 158{
 159        return ((xfs_fileoff_t)r->l0 &
 160                 xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
 161}
 162
 163xfs_exntst_t
 164xfs_bmbt_get_state(
 165        xfs_bmbt_rec_host_t     *r)
 166{
 167        int     ext_flag;
 168
 169        ext_flag = (int)((r->l0) >> (64 - BMBT_EXNTFLAG_BITLEN));
 170        return xfs_extent_state(xfs_bmbt_get_blockcount(r),
 171                                ext_flag);
 172}
 173
 174/*
 175 * Extract the blockcount field from an on disk bmap extent record.
 176 */
 177xfs_filblks_t
 178xfs_bmbt_disk_get_blockcount(
 179        xfs_bmbt_rec_t  *r)
 180{
 181        return (xfs_filblks_t)(be64_to_cpu(r->l1) & xfs_mask64lo(21));
 182}
 183
 184/*
 185 * Extract the startoff field from a disk format bmap extent record.
 186 */
 187xfs_fileoff_t
 188xfs_bmbt_disk_get_startoff(
 189        xfs_bmbt_rec_t  *r)
 190{
 191        return ((xfs_fileoff_t)be64_to_cpu(r->l0) &
 192                 xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
 193}
 194
 195
 196/*
 197 * Set all the fields in a bmap extent record from the arguments.
 198 */
 199void
 200xfs_bmbt_set_allf(
 201        xfs_bmbt_rec_host_t     *r,
 202        xfs_fileoff_t           startoff,
 203        xfs_fsblock_t           startblock,
 204        xfs_filblks_t           blockcount,
 205        xfs_exntst_t            state)
 206{
 207        int             extent_flag = (state == XFS_EXT_NORM) ? 0 : 1;
 208
 209        ASSERT(state == XFS_EXT_NORM || state == XFS_EXT_UNWRITTEN);
 210        ASSERT((startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)) == 0);
 211        ASSERT((blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)) == 0);
 212
 213        ASSERT((startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)) == 0);
 214
 215        r->l0 = ((xfs_bmbt_rec_base_t)extent_flag << 63) |
 216                ((xfs_bmbt_rec_base_t)startoff << 9) |
 217                ((xfs_bmbt_rec_base_t)startblock >> 43);
 218        r->l1 = ((xfs_bmbt_rec_base_t)startblock << 21) |
 219                ((xfs_bmbt_rec_base_t)blockcount &
 220                (xfs_bmbt_rec_base_t)xfs_mask64lo(21));
 221}
 222
 223/*
 224 * Set all the fields in a bmap extent record from the uncompressed form.
 225 */
 226void
 227xfs_bmbt_set_all(
 228        xfs_bmbt_rec_host_t *r,
 229        xfs_bmbt_irec_t *s)
 230{
 231        xfs_bmbt_set_allf(r, s->br_startoff, s->br_startblock,
 232                             s->br_blockcount, s->br_state);
 233}
 234
 235
 236/*
 237 * Set all the fields in a disk format bmap extent record from the arguments.
 238 */
 239void
 240xfs_bmbt_disk_set_allf(
 241        xfs_bmbt_rec_t          *r,
 242        xfs_fileoff_t           startoff,
 243        xfs_fsblock_t           startblock,
 244        xfs_filblks_t           blockcount,
 245        xfs_exntst_t            state)
 246{
 247        int                     extent_flag = (state == XFS_EXT_NORM) ? 0 : 1;
 248
 249        ASSERT(state == XFS_EXT_NORM || state == XFS_EXT_UNWRITTEN);
 250        ASSERT((startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)) == 0);
 251        ASSERT((blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)) == 0);
 252        ASSERT((startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)) == 0);
 253
 254        r->l0 = cpu_to_be64(
 255                ((xfs_bmbt_rec_base_t)extent_flag << 63) |
 256                 ((xfs_bmbt_rec_base_t)startoff << 9) |
 257                 ((xfs_bmbt_rec_base_t)startblock >> 43));
 258        r->l1 = cpu_to_be64(
 259                ((xfs_bmbt_rec_base_t)startblock << 21) |
 260                 ((xfs_bmbt_rec_base_t)blockcount &
 261                  (xfs_bmbt_rec_base_t)xfs_mask64lo(21)));
 262}
 263
 264/*
 265 * Set all the fields in a bmap extent record from the uncompressed form.
 266 */
 267STATIC void
 268xfs_bmbt_disk_set_all(
 269        xfs_bmbt_rec_t  *r,
 270        xfs_bmbt_irec_t *s)
 271{
 272        xfs_bmbt_disk_set_allf(r, s->br_startoff, s->br_startblock,
 273                                  s->br_blockcount, s->br_state);
 274}
 275
 276/*
 277 * Set the blockcount field in a bmap extent record.
 278 */
 279void
 280xfs_bmbt_set_blockcount(
 281        xfs_bmbt_rec_host_t *r,
 282        xfs_filblks_t   v)
 283{
 284        ASSERT((v & xfs_mask64hi(43)) == 0);
 285        r->l1 = (r->l1 & (xfs_bmbt_rec_base_t)xfs_mask64hi(43)) |
 286                  (xfs_bmbt_rec_base_t)(v & xfs_mask64lo(21));
 287}
 288
 289/*
 290 * Set the startblock field in a bmap extent record.
 291 */
 292void
 293xfs_bmbt_set_startblock(
 294        xfs_bmbt_rec_host_t *r,
 295        xfs_fsblock_t   v)
 296{
 297        ASSERT((v & xfs_mask64hi(12)) == 0);
 298        r->l0 = (r->l0 & (xfs_bmbt_rec_base_t)xfs_mask64hi(55)) |
 299                  (xfs_bmbt_rec_base_t)(v >> 43);
 300        r->l1 = (r->l1 & (xfs_bmbt_rec_base_t)xfs_mask64lo(21)) |
 301                  (xfs_bmbt_rec_base_t)(v << 21);
 302}
 303
 304/*
 305 * Set the startoff field in a bmap extent record.
 306 */
 307void
 308xfs_bmbt_set_startoff(
 309        xfs_bmbt_rec_host_t *r,
 310        xfs_fileoff_t   v)
 311{
 312        ASSERT((v & xfs_mask64hi(9)) == 0);
 313        r->l0 = (r->l0 & (xfs_bmbt_rec_base_t) xfs_mask64hi(1)) |
 314                ((xfs_bmbt_rec_base_t)v << 9) |
 315                  (r->l0 & (xfs_bmbt_rec_base_t)xfs_mask64lo(9));
 316}
 317
 318/*
 319 * Set the extent state field in a bmap extent record.
 320 */
 321void
 322xfs_bmbt_set_state(
 323        xfs_bmbt_rec_host_t *r,
 324        xfs_exntst_t    v)
 325{
 326        ASSERT(v == XFS_EXT_NORM || v == XFS_EXT_UNWRITTEN);
 327        if (v == XFS_EXT_NORM)
 328                r->l0 &= xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN);
 329        else
 330                r->l0 |= xfs_mask64hi(BMBT_EXNTFLAG_BITLEN);
 331}
 332
 333/*
 334 * Convert in-memory form of btree root to on-disk form.
 335 */
 336void
 337xfs_bmbt_to_bmdr(
 338        struct xfs_mount        *mp,
 339        struct xfs_btree_block  *rblock,
 340        int                     rblocklen,
 341        xfs_bmdr_block_t        *dblock,
 342        int                     dblocklen)
 343{
 344        int                     dmxr;
 345        xfs_bmbt_key_t          *fkp;
 346        __be64                  *fpp;
 347        xfs_bmbt_key_t          *tkp;
 348        __be64                  *tpp;
 349
 350        if (xfs_sb_version_hascrc(&mp->m_sb)) {
 351                ASSERT(rblock->bb_magic == cpu_to_be32(XFS_BMAP_CRC_MAGIC));
 352                ASSERT(uuid_equal(&rblock->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid));
 353                ASSERT(rblock->bb_u.l.bb_blkno ==
 354                       cpu_to_be64(XFS_BUF_DADDR_NULL));
 355        } else
 356                ASSERT(rblock->bb_magic == cpu_to_be32(XFS_BMAP_MAGIC));
 357        ASSERT(rblock->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK));
 358        ASSERT(rblock->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK));
 359        ASSERT(rblock->bb_level != 0);
 360        dblock->bb_level = rblock->bb_level;
 361        dblock->bb_numrecs = rblock->bb_numrecs;
 362        dmxr = xfs_bmdr_maxrecs(dblocklen, 0);
 363        fkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
 364        tkp = XFS_BMDR_KEY_ADDR(dblock, 1);
 365        fpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
 366        tpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
 367        dmxr = be16_to_cpu(dblock->bb_numrecs);
 368        memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
 369        memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
 370}
 371
 372/*
 373 * Check extent records, which have just been read, for
 374 * any bit in the extent flag field. ASSERT on debug
 375 * kernels, as this condition should not occur.
 376 * Return an error condition (1) if any flags found,
 377 * otherwise return 0.
 378 */
 379
 380int
 381xfs_check_nostate_extents(
 382        xfs_ifork_t             *ifp,
 383        xfs_extnum_t            idx,
 384        xfs_extnum_t            num)
 385{
 386        for (; num > 0; num--, idx++) {
 387                xfs_bmbt_rec_host_t *ep = xfs_iext_get_ext(ifp, idx);
 388                if ((ep->l0 >>
 389                     (64 - BMBT_EXNTFLAG_BITLEN)) != 0) {
 390                        ASSERT(0);
 391                        return 1;
 392                }
 393        }
 394        return 0;
 395}
 396
 397
 398STATIC struct xfs_btree_cur *
 399xfs_bmbt_dup_cursor(
 400        struct xfs_btree_cur    *cur)
 401{
 402        struct xfs_btree_cur    *new;
 403
 404        new = xfs_bmbt_init_cursor(cur->bc_mp, cur->bc_tp,
 405                        cur->bc_private.b.ip, cur->bc_private.b.whichfork);
 406
 407        /*
 408         * Copy the firstblock, flist, and flags values,
 409         * since init cursor doesn't get them.
 410         */
 411        new->bc_private.b.firstblock = cur->bc_private.b.firstblock;
 412        new->bc_private.b.flist = cur->bc_private.b.flist;
 413        new->bc_private.b.flags = cur->bc_private.b.flags;
 414
 415        return new;
 416}
 417
 418STATIC void
 419xfs_bmbt_update_cursor(
 420        struct xfs_btree_cur    *src,
 421        struct xfs_btree_cur    *dst)
 422{
 423        ASSERT((dst->bc_private.b.firstblock != NULLFSBLOCK) ||
 424               (dst->bc_private.b.ip->i_d.di_flags & XFS_DIFLAG_REALTIME));
 425        ASSERT(dst->bc_private.b.flist == src->bc_private.b.flist);
 426
 427        dst->bc_private.b.allocated += src->bc_private.b.allocated;
 428        dst->bc_private.b.firstblock = src->bc_private.b.firstblock;
 429
 430        src->bc_private.b.allocated = 0;
 431}
 432
 433STATIC int
 434xfs_bmbt_alloc_block(
 435        struct xfs_btree_cur    *cur,
 436        union xfs_btree_ptr     *start,
 437        union xfs_btree_ptr     *new,
 438        int                     *stat)
 439{
 440        xfs_alloc_arg_t         args;           /* block allocation args */
 441        int                     error;          /* error return value */
 442
 443        memset(&args, 0, sizeof(args));
 444        args.tp = cur->bc_tp;
 445        args.mp = cur->bc_mp;
 446        args.fsbno = cur->bc_private.b.firstblock;
 447        args.firstblock = args.fsbno;
 448
 449        if (args.fsbno == NULLFSBLOCK) {
 450                args.fsbno = be64_to_cpu(start->l);
 451                args.type = XFS_ALLOCTYPE_START_BNO;
 452                /*
 453                 * Make sure there is sufficient room left in the AG to
 454                 * complete a full tree split for an extent insert.  If
 455                 * we are converting the middle part of an extent then
 456                 * we may need space for two tree splits.
 457                 *
 458                 * We are relying on the caller to make the correct block
 459                 * reservation for this operation to succeed.  If the
 460                 * reservation amount is insufficient then we may fail a
 461                 * block allocation here and corrupt the filesystem.
 462                 */
 463                args.minleft = xfs_trans_get_block_res(args.tp);
 464        } else if (cur->bc_private.b.flist->xbf_low) {
 465                args.type = XFS_ALLOCTYPE_START_BNO;
 466        } else {
 467                args.type = XFS_ALLOCTYPE_NEAR_BNO;
 468        }
 469
 470        args.minlen = args.maxlen = args.prod = 1;
 471        args.wasdel = cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL;
 472        if (!args.wasdel && xfs_trans_get_block_res(args.tp) == 0) {
 473                error = -ENOSPC;
 474                goto error0;
 475        }
 476        error = xfs_alloc_vextent(&args);
 477        if (error)
 478                goto error0;
 479
 480        if (args.fsbno == NULLFSBLOCK && args.minleft) {
 481                /*
 482                 * Could not find an AG with enough free space to satisfy
 483                 * a full btree split.  Try again without minleft and if
 484                 * successful activate the lowspace algorithm.
 485                 */
 486                args.fsbno = 0;
 487                args.type = XFS_ALLOCTYPE_FIRST_AG;
 488                args.minleft = 0;
 489                error = xfs_alloc_vextent(&args);
 490                if (error)
 491                        goto error0;
 492                cur->bc_private.b.flist->xbf_low = 1;
 493        }
 494        if (args.fsbno == NULLFSBLOCK) {
 495                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
 496                *stat = 0;
 497                return 0;
 498        }
 499        ASSERT(args.len == 1);
 500        cur->bc_private.b.firstblock = args.fsbno;
 501        cur->bc_private.b.allocated++;
 502        cur->bc_private.b.ip->i_d.di_nblocks++;
 503        xfs_trans_log_inode(args.tp, cur->bc_private.b.ip, XFS_ILOG_CORE);
 504        xfs_trans_mod_dquot_byino(args.tp, cur->bc_private.b.ip,
 505                        XFS_TRANS_DQ_BCOUNT, 1L);
 506
 507        new->l = cpu_to_be64(args.fsbno);
 508
 509        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
 510        *stat = 1;
 511        return 0;
 512
 513 error0:
 514        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
 515        return error;
 516}
 517
 518STATIC int
 519xfs_bmbt_free_block(
 520        struct xfs_btree_cur    *cur,
 521        struct xfs_buf          *bp)
 522{
 523        struct xfs_mount        *mp = cur->bc_mp;
 524        struct xfs_inode        *ip = cur->bc_private.b.ip;
 525        struct xfs_trans        *tp = cur->bc_tp;
 526        xfs_fsblock_t           fsbno = XFS_DADDR_TO_FSB(mp, XFS_BUF_ADDR(bp));
 527
 528        xfs_bmap_add_free(fsbno, 1, cur->bc_private.b.flist, mp);
 529        ip->i_d.di_nblocks--;
 530
 531        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 532        xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
 533        xfs_trans_binval(tp, bp);
 534        return 0;
 535}
 536
 537STATIC int
 538xfs_bmbt_get_minrecs(
 539        struct xfs_btree_cur    *cur,
 540        int                     level)
 541{
 542        if (level == cur->bc_nlevels - 1) {
 543                struct xfs_ifork        *ifp;
 544
 545                ifp = XFS_IFORK_PTR(cur->bc_private.b.ip,
 546                                    cur->bc_private.b.whichfork);
 547
 548                return xfs_bmbt_maxrecs(cur->bc_mp,
 549                                        ifp->if_broot_bytes, level == 0) / 2;
 550        }
 551
 552        return cur->bc_mp->m_bmap_dmnr[level != 0];
 553}
 554
 555int
 556xfs_bmbt_get_maxrecs(
 557        struct xfs_btree_cur    *cur,
 558        int                     level)
 559{
 560        if (level == cur->bc_nlevels - 1) {
 561                struct xfs_ifork        *ifp;
 562
 563                ifp = XFS_IFORK_PTR(cur->bc_private.b.ip,
 564                                    cur->bc_private.b.whichfork);
 565
 566                return xfs_bmbt_maxrecs(cur->bc_mp,
 567                                        ifp->if_broot_bytes, level == 0);
 568        }
 569
 570        return cur->bc_mp->m_bmap_dmxr[level != 0];
 571
 572}
 573
 574/*
 575 * Get the maximum records we could store in the on-disk format.
 576 *
 577 * For non-root nodes this is equivalent to xfs_bmbt_get_maxrecs, but
 578 * for the root node this checks the available space in the dinode fork
 579 * so that we can resize the in-memory buffer to match it.  After a
 580 * resize to the maximum size this function returns the same value
 581 * as xfs_bmbt_get_maxrecs for the root node, too.
 582 */
 583STATIC int
 584xfs_bmbt_get_dmaxrecs(
 585        struct xfs_btree_cur    *cur,
 586        int                     level)
 587{
 588        if (level != cur->bc_nlevels - 1)
 589                return cur->bc_mp->m_bmap_dmxr[level != 0];
 590        return xfs_bmdr_maxrecs(cur->bc_private.b.forksize, level == 0);
 591}
 592
 593STATIC void
 594xfs_bmbt_init_key_from_rec(
 595        union xfs_btree_key     *key,
 596        union xfs_btree_rec     *rec)
 597{
 598        key->bmbt.br_startoff =
 599                cpu_to_be64(xfs_bmbt_disk_get_startoff(&rec->bmbt));
 600}
 601
 602STATIC void
 603xfs_bmbt_init_rec_from_key(
 604        union xfs_btree_key     *key,
 605        union xfs_btree_rec     *rec)
 606{
 607        ASSERT(key->bmbt.br_startoff != 0);
 608
 609        xfs_bmbt_disk_set_allf(&rec->bmbt, be64_to_cpu(key->bmbt.br_startoff),
 610                               0, 0, XFS_EXT_NORM);
 611}
 612
 613STATIC void
 614xfs_bmbt_init_rec_from_cur(
 615        struct xfs_btree_cur    *cur,
 616        union xfs_btree_rec     *rec)
 617{
 618        xfs_bmbt_disk_set_all(&rec->bmbt, &cur->bc_rec.b);
 619}
 620
 621STATIC void
 622xfs_bmbt_init_ptr_from_cur(
 623        struct xfs_btree_cur    *cur,
 624        union xfs_btree_ptr     *ptr)
 625{
 626        ptr->l = 0;
 627}
 628
 629STATIC __int64_t
 630xfs_bmbt_key_diff(
 631        struct xfs_btree_cur    *cur,
 632        union xfs_btree_key     *key)
 633{
 634        return (__int64_t)be64_to_cpu(key->bmbt.br_startoff) -
 635                                      cur->bc_rec.b.br_startoff;
 636}
 637
 638static bool
 639xfs_bmbt_verify(
 640        struct xfs_buf          *bp)
 641{
 642        struct xfs_mount        *mp = bp->b_target->bt_mount;
 643        struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
 644        unsigned int            level;
 645
 646        switch (block->bb_magic) {
 647        case cpu_to_be32(XFS_BMAP_CRC_MAGIC):
 648                if (!xfs_sb_version_hascrc(&mp->m_sb))
 649                        return false;
 650                if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid))
 651                        return false;
 652                if (be64_to_cpu(block->bb_u.l.bb_blkno) != bp->b_bn)
 653                        return false;
 654                /*
 655                 * XXX: need a better way of verifying the owner here. Right now
 656                 * just make sure there has been one set.
 657                 */
 658                if (be64_to_cpu(block->bb_u.l.bb_owner) == 0)
 659                        return false;
 660                /* fall through */
 661        case cpu_to_be32(XFS_BMAP_MAGIC):
 662                break;
 663        default:
 664                return false;
 665        }
 666
 667        /*
 668         * numrecs and level verification.
 669         *
 670         * We don't know what fork we belong to, so just verify that the level
 671         * is less than the maximum of the two. Later checks will be more
 672         * precise.
 673         */
 674        level = be16_to_cpu(block->bb_level);
 675        if (level > max(mp->m_bm_maxlevels[0], mp->m_bm_maxlevels[1]))
 676                return false;
 677        if (be16_to_cpu(block->bb_numrecs) > mp->m_bmap_dmxr[level != 0])
 678                return false;
 679
 680        /* sibling pointer verification */
 681        if (!block->bb_u.l.bb_leftsib ||
 682            (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
 683             !XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_u.l.bb_leftsib))))
 684                return false;
 685        if (!block->bb_u.l.bb_rightsib ||
 686            (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
 687             !XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_u.l.bb_rightsib))))
 688                return false;
 689
 690        return true;
 691}
 692
 693static void
 694xfs_bmbt_read_verify(
 695        struct xfs_buf  *bp)
 696{
 697        if (!xfs_btree_lblock_verify_crc(bp))
 698                xfs_buf_ioerror(bp, -EFSBADCRC);
 699        else if (!xfs_bmbt_verify(bp))
 700                xfs_buf_ioerror(bp, -EFSCORRUPTED);
 701
 702        if (bp->b_error) {
 703                trace_xfs_btree_corrupt(bp, _RET_IP_);
 704                xfs_verifier_error(bp);
 705        }
 706}
 707
 708static void
 709xfs_bmbt_write_verify(
 710        struct xfs_buf  *bp)
 711{
 712        if (!xfs_bmbt_verify(bp)) {
 713                trace_xfs_btree_corrupt(bp, _RET_IP_);
 714                xfs_buf_ioerror(bp, -EFSCORRUPTED);
 715                xfs_verifier_error(bp);
 716                return;
 717        }
 718        xfs_btree_lblock_calc_crc(bp);
 719}
 720
 721const struct xfs_buf_ops xfs_bmbt_buf_ops = {
 722        .verify_read = xfs_bmbt_read_verify,
 723        .verify_write = xfs_bmbt_write_verify,
 724};
 725
 726
 727#if defined(DEBUG) || defined(XFS_WARN)
 728STATIC int
 729xfs_bmbt_keys_inorder(
 730        struct xfs_btree_cur    *cur,
 731        union xfs_btree_key     *k1,
 732        union xfs_btree_key     *k2)
 733{
 734        return be64_to_cpu(k1->bmbt.br_startoff) <
 735                be64_to_cpu(k2->bmbt.br_startoff);
 736}
 737
 738STATIC int
 739xfs_bmbt_recs_inorder(
 740        struct xfs_btree_cur    *cur,
 741        union xfs_btree_rec     *r1,
 742        union xfs_btree_rec     *r2)
 743{
 744        return xfs_bmbt_disk_get_startoff(&r1->bmbt) +
 745                xfs_bmbt_disk_get_blockcount(&r1->bmbt) <=
 746                xfs_bmbt_disk_get_startoff(&r2->bmbt);
 747}
 748#endif  /* DEBUG */
 749
 750static const struct xfs_btree_ops xfs_bmbt_ops = {
 751        .rec_len                = sizeof(xfs_bmbt_rec_t),
 752        .key_len                = sizeof(xfs_bmbt_key_t),
 753
 754        .dup_cursor             = xfs_bmbt_dup_cursor,
 755        .update_cursor          = xfs_bmbt_update_cursor,
 756        .alloc_block            = xfs_bmbt_alloc_block,
 757        .free_block             = xfs_bmbt_free_block,
 758        .get_maxrecs            = xfs_bmbt_get_maxrecs,
 759        .get_minrecs            = xfs_bmbt_get_minrecs,
 760        .get_dmaxrecs           = xfs_bmbt_get_dmaxrecs,
 761        .init_key_from_rec      = xfs_bmbt_init_key_from_rec,
 762        .init_rec_from_key      = xfs_bmbt_init_rec_from_key,
 763        .init_rec_from_cur      = xfs_bmbt_init_rec_from_cur,
 764        .init_ptr_from_cur      = xfs_bmbt_init_ptr_from_cur,
 765        .key_diff               = xfs_bmbt_key_diff,
 766        .buf_ops                = &xfs_bmbt_buf_ops,
 767#if defined(DEBUG) || defined(XFS_WARN)
 768        .keys_inorder           = xfs_bmbt_keys_inorder,
 769        .recs_inorder           = xfs_bmbt_recs_inorder,
 770#endif
 771};
 772
 773/*
 774 * Allocate a new bmap btree cursor.
 775 */
 776struct xfs_btree_cur *                          /* new bmap btree cursor */
 777xfs_bmbt_init_cursor(
 778        struct xfs_mount        *mp,            /* file system mount point */
 779        struct xfs_trans        *tp,            /* transaction pointer */
 780        struct xfs_inode        *ip,            /* inode owning the btree */
 781        int                     whichfork)      /* data or attr fork */
 782{
 783        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
 784        struct xfs_btree_cur    *cur;
 785
 786        cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
 787
 788        cur->bc_tp = tp;
 789        cur->bc_mp = mp;
 790        cur->bc_nlevels = be16_to_cpu(ifp->if_broot->bb_level) + 1;
 791        cur->bc_btnum = XFS_BTNUM_BMAP;
 792        cur->bc_blocklog = mp->m_sb.sb_blocklog;
 793
 794        cur->bc_ops = &xfs_bmbt_ops;
 795        cur->bc_flags = XFS_BTREE_LONG_PTRS | XFS_BTREE_ROOT_IN_INODE;
 796        if (xfs_sb_version_hascrc(&mp->m_sb))
 797                cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
 798
 799        cur->bc_private.b.forksize = XFS_IFORK_SIZE(ip, whichfork);
 800        cur->bc_private.b.ip = ip;
 801        cur->bc_private.b.firstblock = NULLFSBLOCK;
 802        cur->bc_private.b.flist = NULL;
 803        cur->bc_private.b.allocated = 0;
 804        cur->bc_private.b.flags = 0;
 805        cur->bc_private.b.whichfork = whichfork;
 806
 807        return cur;
 808}
 809
 810/*
 811 * Calculate number of records in a bmap btree block.
 812 */
 813int
 814xfs_bmbt_maxrecs(
 815        struct xfs_mount        *mp,
 816        int                     blocklen,
 817        int                     leaf)
 818{
 819        blocklen -= XFS_BMBT_BLOCK_LEN(mp);
 820
 821        if (leaf)
 822                return blocklen / sizeof(xfs_bmbt_rec_t);
 823        return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t));
 824}
 825
 826/*
 827 * Calculate number of records in a bmap btree inode root.
 828 */
 829int
 830xfs_bmdr_maxrecs(
 831        int                     blocklen,
 832        int                     leaf)
 833{
 834        blocklen -= sizeof(xfs_bmdr_block_t);
 835
 836        if (leaf)
 837                return blocklen / sizeof(xfs_bmdr_rec_t);
 838        return blocklen / (sizeof(xfs_bmdr_key_t) + sizeof(xfs_bmdr_ptr_t));
 839}
 840
 841/*
 842 * Change the owner of a btree format fork fo the inode passed in. Change it to
 843 * the owner of that is passed in so that we can change owners before or after
 844 * we switch forks between inodes. The operation that the caller is doing will
 845 * determine whether is needs to change owner before or after the switch.
 846 *
 847 * For demand paged transactional modification, the fork switch should be done
 848 * after reading in all the blocks, modifying them and pinning them in the
 849 * transaction. For modification when the buffers are already pinned in memory,
 850 * the fork switch can be done before changing the owner as we won't need to
 851 * validate the owner until the btree buffers are unpinned and writes can occur
 852 * again.
 853 *
 854 * For recovery based ownership change, there is no transactional context and
 855 * so a buffer list must be supplied so that we can record the buffers that we
 856 * modified for the caller to issue IO on.
 857 */
 858int
 859xfs_bmbt_change_owner(
 860        struct xfs_trans        *tp,
 861        struct xfs_inode        *ip,
 862        int                     whichfork,
 863        xfs_ino_t               new_owner,
 864        struct list_head        *buffer_list)
 865{
 866        struct xfs_btree_cur    *cur;
 867        int                     error;
 868
 869        ASSERT(tp || buffer_list);
 870        ASSERT(!(tp && buffer_list));
 871        if (whichfork == XFS_DATA_FORK)
 872                ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_BTREE);
 873        else
 874                ASSERT(ip->i_d.di_aformat == XFS_DINODE_FMT_BTREE);
 875
 876        cur = xfs_bmbt_init_cursor(ip->i_mount, tp, ip, whichfork);
 877        if (!cur)
 878                return -ENOMEM;
 879
 880        error = xfs_btree_change_owner(cur, new_owner, buffer_list);
 881        xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
 882        return error;
 883}
 884