fs/xfs/xfs_bmap_btree.c

   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_types.h"
  21 #include "xfs_bit.h"
  22 #include "xfs_log.h"
  23 #include "xfs_inum.h"
  24 #include "xfs_trans.h"
  25 #include "xfs_sb.h"
  26 #include "xfs_ag.h"
  27 #include "xfs_dir2.h"
  28 #include "xfs_dmapi.h"
  29 #include "xfs_mount.h"
  30 #include "xfs_bmap_btree.h"
  31 #include "xfs_alloc_btree.h"
  32 #include "xfs_ialloc_btree.h"
  33 #include "xfs_dir2_sf.h"
  34 #include "xfs_attr_sf.h"
  35 #include "xfs_dinode.h"
  36 #include "xfs_inode.h"
  37 #include "xfs_inode_item.h"
  38 #include "xfs_alloc.h"
  39 #include "xfs_btree.h"
  40 #include "xfs_btree_trace.h"
  41 #include "xfs_ialloc.h"
  42 #include "xfs_itable.h"
  43 #include "xfs_bmap.h"
  44 #include "xfs_error.h"
  45 #include "xfs_quota.h"
  46
  47 /*
  48  * Determine the extent state.
  49  */
  50 /* ARGSUSED */
  51 STATIC xfs_exntst_t
  52 xfs_extent_state(
  53         xfs_filblks_t           blks,
  54         int                     extent_flag)
  55 {
  56         if (extent_flag) {
  57                 ASSERT(blks != 0);      /* saved for DMIG */
  58                 return XFS_EXT_UNWRITTEN;
  59         }
  60         return XFS_EXT_NORM;
  61 }
  62
  63 /*
  64  * Convert on-disk form of btree root to in-memory form.
  65  */
  66 void
  67 xfs_bmdr_to_bmbt(
  68         struct xfs_mount        *mp,
  69         xfs_bmdr_block_t        *dblock,
  70         int                     dblocklen,
  71         struct xfs_btree_block  *rblock,
  72         int                     rblocklen)
  73 {
  74         int                     dmxr;
  75         xfs_bmbt_key_t          *fkp;
  76         __be64                  *fpp;
  77         xfs_bmbt_key_t          *tkp;
  78         __be64                  *tpp;
  79
  80         rblock->bb_magic = cpu_to_be32(XFS_BMAP_MAGIC);
  81         rblock->bb_level = dblock->bb_level;
  82         ASSERT(be16_to_cpu(rblock->bb_level) > 0);
  83         rblock->bb_numrecs = dblock->bb_numrecs;
  84         rblock->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
  85         rblock->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
  86         dmxr = xfs_bmdr_maxrecs(mp, dblocklen, 0);
  87         fkp = XFS_BMDR_KEY_ADDR(dblock, 1);
  88         tkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
  89         fpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
  90         tpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
  91         dmxr = be16_to_cpu(dblock->bb_numrecs);
  92         memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
  93         memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
  94 }
  95
  96 /*
  97  * Convert a compressed bmap extent record to an uncompressed form.
  98  * This code must be in sync with the routines xfs_bmbt_get_startoff,
  99  * xfs_bmbt_get_startblock, xfs_bmbt_get_blockcount and xfs_bmbt_get_state.
 100  */
 101
 102 STATIC_INLINE void
 103 __xfs_bmbt_get_all(
 104                 __uint64_t l0,
 105                 __uint64_t l1,
 106                 xfs_bmbt_irec_t *s)
 107 {
 108         int     ext_flag;
 109         xfs_exntst_t st;
 110
 111         ext_flag = (int)(l0 >> (64 - BMBT_EXNTFLAG_BITLEN));
 112         s->br_startoff = ((xfs_fileoff_t)l0 &
 113                            xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
 114 #if XFS_BIG_BLKNOS
 115         s->br_startblock = (((xfs_fsblock_t)l0 & xfs_mask64lo(9)) << 43) |
 116                            (((xfs_fsblock_t)l1) >> 21);
 117 #else
 118 #ifdef DEBUG
 119         {
 120                 xfs_dfsbno_t    b;
 121
 122                 b = (((xfs_dfsbno_t)l0 & xfs_mask64lo(9)) << 43) |
 123                     (((xfs_dfsbno_t)l1) >> 21);
 124                 ASSERT((b >> 32) == 0 || isnulldstartblock(b));
 125                 s->br_startblock = (xfs_fsblock_t)b;
 126         }
 127 #else   /* !DEBUG */
 128         s->br_startblock = (xfs_fsblock_t)(((xfs_dfsbno_t)l1) >> 21);
 129 #endif  /* DEBUG */
 130 #endif  /* XFS_BIG_BLKNOS */
 131         s->br_blockcount = (xfs_filblks_t)(l1 & xfs_mask64lo(21));
 132         /* This is xfs_extent_state() in-line */
 133         if (ext_flag) {
 134                 ASSERT(s->br_blockcount != 0);  /* saved for DMIG */
 135                 st = XFS_EXT_UNWRITTEN;
 136         } else
 137                 st = XFS_EXT_NORM;
 138         s->br_state = st;
 139 }
 140
 141 void
 142 xfs_bmbt_get_all(
 143         xfs_bmbt_rec_host_t *r,
 144         xfs_bmbt_irec_t *s)
 145 {
 146         __xfs_bmbt_get_all(r->l0, r->l1, s);
 147 }
 148
 149 /*
 150  * Extract the blockcount field from an in memory bmap extent record.
 151  */
 152 xfs_filblks_t
 153 xfs_bmbt_get_blockcount(
 154         xfs_bmbt_rec_host_t     *r)
 155 {
 156         return (xfs_filblks_t)(r->l1 & xfs_mask64lo(21));
 157 }
 158
 159 /*
 160  * Extract the startblock field from an in memory bmap extent record.
 161  */
 162 xfs_fsblock_t
 163 xfs_bmbt_get_startblock(
 164         xfs_bmbt_rec_host_t     *r)
 165 {
 166 #if XFS_BIG_BLKNOS
 167         return (((xfs_fsblock_t)r->l0 & xfs_mask64lo(9)) << 43) |
 168                (((xfs_fsblock_t)r->l1) >> 21);
 169 #else
 170 #ifdef DEBUG
 171         xfs_dfsbno_t    b;
 172
 173         b = (((xfs_dfsbno_t)r->l0 & xfs_mask64lo(9)) << 43) |
 174             (((xfs_dfsbno_t)r->l1) >> 21);
 175         ASSERT((b >> 32) == 0 || isnulldstartblock(b));
 176         return (xfs_fsblock_t)b;
 177 #else   /* !DEBUG */
 178         return (xfs_fsblock_t)(((xfs_dfsbno_t)r->l1) >> 21);
 179 #endif  /* DEBUG */
 180 #endif  /* XFS_BIG_BLKNOS */
 181 }
 182
 183 /*
 184  * Extract the startoff field from an in memory bmap extent record.
 185  */
 186 xfs_fileoff_t
 187 xfs_bmbt_get_startoff(
 188         xfs_bmbt_rec_host_t     *r)
 189 {
 190         return ((xfs_fileoff_t)r->l0 &
 191                  xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
 192 }
 193
 194 xfs_exntst_t
 195 xfs_bmbt_get_state(
 196         xfs_bmbt_rec_host_t     *r)
 197 {
 198         int     ext_flag;
 199
 200         ext_flag = (int)((r->l0) >> (64 - BMBT_EXNTFLAG_BITLEN));
 201         return xfs_extent_state(xfs_bmbt_get_blockcount(r),
 202                                 ext_flag);
 203 }
 204
 205 /* Endian flipping versions of the bmbt extraction functions */
 206 void
 207 xfs_bmbt_disk_get_all(
 208         xfs_bmbt_rec_t  *r,
 209         xfs_bmbt_irec_t *s)
 210 {
 211         __xfs_bmbt_get_all(get_unaligned_be64(&r->l0),
 212                                 get_unaligned_be64(&r->l1), s);
 213 }
 214
 215 /*
 216  * Extract the blockcount field from an on disk bmap extent record.
 217  */
 218 xfs_filblks_t
 219 xfs_bmbt_disk_get_blockcount(
 220         xfs_bmbt_rec_t  *r)
 221 {
 222         return (xfs_filblks_t)(be64_to_cpu(r->l1) & xfs_mask64lo(21));
 223 }
 224
 225 /*
 226  * Extract the startoff field from a disk format bmap extent record.
 227  */
 228 xfs_fileoff_t
 229 xfs_bmbt_disk_get_startoff(
 230         xfs_bmbt_rec_t  *r)
 231 {
 232         return ((xfs_fileoff_t)be64_to_cpu(r->l0) &
 233                  xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
 234 }
 235
 236
 237 /*
 238  * Set all the fields in a bmap extent record from the arguments.
 239  */
 240 void
 241 xfs_bmbt_set_allf(
 242         xfs_bmbt_rec_host_t     *r,
 243         xfs_fileoff_t           startoff,
 244         xfs_fsblock_t           startblock,
 245         xfs_filblks_t           blockcount,
 246         xfs_exntst_t            state)
 247 {
 248         int             extent_flag = (state == XFS_EXT_NORM) ? 0 : 1;
 249
 250         ASSERT(state == XFS_EXT_NORM || state == XFS_EXT_UNWRITTEN);
 251         ASSERT((startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)) == 0);
 252         ASSERT((blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)) == 0);
 253
 254 #if XFS_BIG_BLKNOS
 255         ASSERT((startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)) == 0);
 256
 257         r->l0 = ((xfs_bmbt_rec_base_t)extent_flag << 63) |
 258                 ((xfs_bmbt_rec_base_t)startoff << 9) |
 259                 ((xfs_bmbt_rec_base_t)startblock >> 43);
 260         r->l1 = ((xfs_bmbt_rec_base_t)startblock << 21) |
 261                 ((xfs_bmbt_rec_base_t)blockcount &
 262                 (xfs_bmbt_rec_base_t)xfs_mask64lo(21));
 263 #else   /* !XFS_BIG_BLKNOS */
 264         if (isnullstartblock(startblock)) {
 265                 r->l0 = ((xfs_bmbt_rec_base_t)extent_flag << 63) |
 266                         ((xfs_bmbt_rec_base_t)startoff << 9) |
 267                          (xfs_bmbt_rec_base_t)xfs_mask64lo(9);
 268                 r->l1 = xfs_mask64hi(11) |
 269                           ((xfs_bmbt_rec_base_t)startblock << 21) |
 270                           ((xfs_bmbt_rec_base_t)blockcount &
 271                            (xfs_bmbt_rec_base_t)xfs_mask64lo(21));
 272         } else {
 273                 r->l0 = ((xfs_bmbt_rec_base_t)extent_flag << 63) |
 274                         ((xfs_bmbt_rec_base_t)startoff << 9);
 275                 r->l1 = ((xfs_bmbt_rec_base_t)startblock << 21) |
 276                          ((xfs_bmbt_rec_base_t)blockcount &
 277                          (xfs_bmbt_rec_base_t)xfs_mask64lo(21));
 278         }
 279 #endif  /* XFS_BIG_BLKNOS */
 280 }
 281
 282 /*
 283  * Set all the fields in a bmap extent record from the uncompressed form.
 284  */
 285 void
 286 xfs_bmbt_set_all(
 287         xfs_bmbt_rec_host_t *r,
 288         xfs_bmbt_irec_t *s)
 289 {
 290         xfs_bmbt_set_allf(r, s->br_startoff, s->br_startblock,
 291                              s->br_blockcount, s->br_state);
 292 }
 293
 294
 295 /*
 296  * Set all the fields in a disk format bmap extent record from the arguments.
 297  */
 298 void
 299 xfs_bmbt_disk_set_allf(
 300         xfs_bmbt_rec_t          *r,
 301         xfs_fileoff_t           startoff,
 302         xfs_fsblock_t           startblock,
 303         xfs_filblks_t           blockcount,
 304         xfs_exntst_t            state)
 305 {
 306         int                     extent_flag = (state == XFS_EXT_NORM) ? 0 : 1;
 307
 308         ASSERT(state == XFS_EXT_NORM || state == XFS_EXT_UNWRITTEN);
 309         ASSERT((startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)) == 0);
 310         ASSERT((blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)) == 0);
 311
 312 #if XFS_BIG_BLKNOS
 313         ASSERT((startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)) == 0);
 314
 315         r->l0 = cpu_to_be64(
 316                 ((xfs_bmbt_rec_base_t)extent_flag << 63) |
 317                  ((xfs_bmbt_rec_base_t)startoff << 9) |
 318                  ((xfs_bmbt_rec_base_t)startblock >> 43));
 319         r->l1 = cpu_to_be64(
 320                 ((xfs_bmbt_rec_base_t)startblock << 21) |
 321                  ((xfs_bmbt_rec_base_t)blockcount &
 322                   (xfs_bmbt_rec_base_t)xfs_mask64lo(21)));
 323 #else   /* !XFS_BIG_BLKNOS */
 324         if (isnullstartblock(startblock)) {
 325                 r->l0 = cpu_to_be64(
 326                         ((xfs_bmbt_rec_base_t)extent_flag << 63) |
 327                          ((xfs_bmbt_rec_base_t)startoff << 9) |
 328                           (xfs_bmbt_rec_base_t)xfs_mask64lo(9));
 329                 r->l1 = cpu_to_be64(xfs_mask64hi(11) |
 330                           ((xfs_bmbt_rec_base_t)startblock << 21) |
 331                           ((xfs_bmbt_rec_base_t)blockcount &
 332                            (xfs_bmbt_rec_base_t)xfs_mask64lo(21)));
 333         } else {
 334                 r->l0 = cpu_to_be64(
 335                         ((xfs_bmbt_rec_base_t)extent_flag << 63) |
 336                          ((xfs_bmbt_rec_base_t)startoff << 9));
 337                 r->l1 = cpu_to_be64(
 338                         ((xfs_bmbt_rec_base_t)startblock << 21) |
 339                          ((xfs_bmbt_rec_base_t)blockcount &
 340                           (xfs_bmbt_rec_base_t)xfs_mask64lo(21)));
 341         }
 342 #endif  /* XFS_BIG_BLKNOS */
 343 }
 344
 345 /*
 346  * Set all the fields in a bmap extent record from the uncompressed form.
 347  */
 348 void
 349 xfs_bmbt_disk_set_all(
 350         xfs_bmbt_rec_t  *r,
 351         xfs_bmbt_irec_t *s)
 352 {
 353         xfs_bmbt_disk_set_allf(r, s->br_startoff, s->br_startblock,
 354                                   s->br_blockcount, s->br_state);
 355 }
 356
 357 /*
 358  * Set the blockcount field in a bmap extent record.
 359  */
 360 void
 361 xfs_bmbt_set_blockcount(
 362         xfs_bmbt_rec_host_t *r,
 363         xfs_filblks_t   v)
 364 {
 365         ASSERT((v & xfs_mask64hi(43)) == 0);
 366         r->l1 = (r->l1 & (xfs_bmbt_rec_base_t)xfs_mask64hi(43)) |
 367                   (xfs_bmbt_rec_base_t)(v & xfs_mask64lo(21));
 368 }
 369
 370 /*
 371  * Set the startblock field in a bmap extent record.
 372  */
 373 void
 374 xfs_bmbt_set_startblock(
 375         xfs_bmbt_rec_host_t *r,
 376         xfs_fsblock_t   v)
 377 {
 378 #if XFS_BIG_BLKNOS
 379         ASSERT((v & xfs_mask64hi(12)) == 0);
 380         r->l0 = (r->l0 & (xfs_bmbt_rec_base_t)xfs_mask64hi(55)) |
 381                   (xfs_bmbt_rec_base_t)(v >> 43);
 382         r->l1 = (r->l1 & (xfs_bmbt_rec_base_t)xfs_mask64lo(21)) |
 383                   (xfs_bmbt_rec_base_t)(v << 21);
 384 #else   /* !XFS_BIG_BLKNOS */
 385         if (isnullstartblock(v)) {
 386                 r->l0 |= (xfs_bmbt_rec_base_t)xfs_mask64lo(9);
 387                 r->l1 = (xfs_bmbt_rec_base_t)xfs_mask64hi(11) |
 388                           ((xfs_bmbt_rec_base_t)v << 21) |
 389                           (r->l1 & (xfs_bmbt_rec_base_t)xfs_mask64lo(21));
 390         } else {
 391                 r->l0 &= ~(xfs_bmbt_rec_base_t)xfs_mask64lo(9);
 392                 r->l1 = ((xfs_bmbt_rec_base_t)v << 21) |
 393                           (r->l1 & (xfs_bmbt_rec_base_t)xfs_mask64lo(21));
 394         }
 395 #endif  /* XFS_BIG_BLKNOS */
 396 }
 397
 398 /*
 399  * Set the startoff field in a bmap extent record.
 400  */
 401 void
 402 xfs_bmbt_set_startoff(
 403         xfs_bmbt_rec_host_t *r,
 404         xfs_fileoff_t   v)
 405 {
 406         ASSERT((v & xfs_mask64hi(9)) == 0);
 407         r->l0 = (r->l0 & (xfs_bmbt_rec_base_t) xfs_mask64hi(1)) |
 408                 ((xfs_bmbt_rec_base_t)v << 9) |
 409                   (r->l0 & (xfs_bmbt_rec_base_t)xfs_mask64lo(9));
 410 }
 411
 412 /*
 413  * Set the extent state field in a bmap extent record.
 414  */
 415 void
 416 xfs_bmbt_set_state(
 417         xfs_bmbt_rec_host_t *r,
 418         xfs_exntst_t    v)
 419 {
 420         ASSERT(v == XFS_EXT_NORM || v == XFS_EXT_UNWRITTEN);
 421         if (v == XFS_EXT_NORM)
 422                 r->l0 &= xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN);
 423         else
 424                 r->l0 |= xfs_mask64hi(BMBT_EXNTFLAG_BITLEN);
 425 }
 426
 427 /*
 428  * Convert in-memory form of btree root to on-disk form.
 429  */
 430 void
 431 xfs_bmbt_to_bmdr(
 432         struct xfs_mount        *mp,
 433         struct xfs_btree_block  *rblock,
 434         int                     rblocklen,
 435         xfs_bmdr_block_t        *dblock,
 436         int                     dblocklen)
 437 {
 438         int                     dmxr;
 439         xfs_bmbt_key_t          *fkp;
 440         __be64                  *fpp;
 441         xfs_bmbt_key_t          *tkp;
 442         __be64                  *tpp;
 443
 444         ASSERT(be32_to_cpu(rblock->bb_magic) == XFS_BMAP_MAGIC);
 445         ASSERT(be64_to_cpu(rblock->bb_u.l.bb_leftsib) == NULLDFSBNO);
 446         ASSERT(be64_to_cpu(rblock->bb_u.l.bb_rightsib) == NULLDFSBNO);
 447         ASSERT(be16_to_cpu(rblock->bb_level) > 0);
 448         dblock->bb_level = rblock->bb_level;
 449         dblock->bb_numrecs = rblock->bb_numrecs;
 450         dmxr = xfs_bmdr_maxrecs(mp, dblocklen, 0);
 451         fkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
 452         tkp = XFS_BMDR_KEY_ADDR(dblock, 1);
 453         fpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
 454         tpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
 455         dmxr = be16_to_cpu(dblock->bb_numrecs);
 456         memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
 457         memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
 458 }
 459
 460 /*
 461  * Check extent records, which have just been read, for
 462  * any bit in the extent flag field. ASSERT on debug
 463  * kernels, as this condition should not occur.
 464  * Return an error condition (1) if any flags found,
 465  * otherwise return 0.
 466  */
 467
 468 int
 469 xfs_check_nostate_extents(
 470         xfs_ifork_t             *ifp,
 471         xfs_extnum_t            idx,
 472         xfs_extnum_t            num)
 473 {
 474         for (; num > 0; num--, idx++) {
 475                 xfs_bmbt_rec_host_t *ep = xfs_iext_get_ext(ifp, idx);
 476                 if ((ep->l0 >>
 477                      (64 - BMBT_EXNTFLAG_BITLEN)) != 0) {
 478                         ASSERT(0);
 479                         return 1;
 480                 }
 481         }
 482         return 0;
 483 }
 484
 485
 486 STATIC struct xfs_btree_cur *
 487 xfs_bmbt_dup_cursor(
 488         struct xfs_btree_cur    *cur)
 489 {
 490         struct xfs_btree_cur    *new;
 491
 492         new = xfs_bmbt_init_cursor(cur->bc_mp, cur->bc_tp,
 493                         cur->bc_private.b.ip, cur->bc_private.b.whichfork);
 494
 495         /*
 496          * Copy the firstblock, flist, and flags values,
 497          * since init cursor doesn't get them.
 498          */
 499         new->bc_private.b.firstblock = cur->bc_private.b.firstblock;
 500         new->bc_private.b.flist = cur->bc_private.b.flist;
 501         new->bc_private.b.flags = cur->bc_private.b.flags;
 502
 503         return new;
 504 }
 505
 506 STATIC void
 507 xfs_bmbt_update_cursor(
 508         struct xfs_btree_cur    *src,
 509         struct xfs_btree_cur    *dst)
 510 {
 511         ASSERT((dst->bc_private.b.firstblock != NULLFSBLOCK) ||
 512                (dst->bc_private.b.ip->i_d.di_flags & XFS_DIFLAG_REALTIME));
 513         ASSERT(dst->bc_private.b.flist == src->bc_private.b.flist);
 514
 515         dst->bc_private.b.allocated += src->bc_private.b.allocated;
 516         dst->bc_private.b.firstblock = src->bc_private.b.firstblock;
 517
 518         src->bc_private.b.allocated = 0;
 519 }
 520
 521 STATIC int
 522 xfs_bmbt_alloc_block(
 523         struct xfs_btree_cur    *cur,
 524         union xfs_btree_ptr     *start,
 525         union xfs_btree_ptr     *new,
 526         int                     length,
 527         int                     *stat)
 528 {
 529         xfs_alloc_arg_t         args;           /* block allocation args */
 530         int                     error;          /* error return value */
 531
 532         memset(&args, 0, sizeof(args));
 533         args.tp = cur->bc_tp;
 534         args.mp = cur->bc_mp;
 535         args.fsbno = cur->bc_private.b.firstblock;
 536         args.firstblock = args.fsbno;
 537
 538         if (args.fsbno == NULLFSBLOCK) {
 539                 args.fsbno = be64_to_cpu(start->l);
 540                 args.type = XFS_ALLOCTYPE_START_BNO;
 541                 /*
 542                  * Make sure there is sufficient room left in the AG to
 543                  * complete a full tree split for an extent insert.  If
 544                  * we are converting the middle part of an extent then
 545                  * we may need space for two tree splits.
 546                  *
 547                  * We are relying on the caller to make the correct block
 548                  * reservation for this operation to succeed.  If the
 549                  * reservation amount is insufficient then we may fail a
 550                  * block allocation here and corrupt the filesystem.
 551                  */
 552                 args.minleft = xfs_trans_get_block_res(args.tp);
 553         } else if (cur->bc_private.b.flist->xbf_low) {
 554                 args.type = XFS_ALLOCTYPE_START_BNO;
 555         } else {
 556                 args.type = XFS_ALLOCTYPE_NEAR_BNO;
 557         }
 558
 559         args.minlen = args.maxlen = args.prod = 1;
 560         args.wasdel = cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL;
 561         if (!args.wasdel && xfs_trans_get_block_res(args.tp) == 0) {
 562                 error = XFS_ERROR(ENOSPC);
 563                 goto error0;
 564         }
 565         error = xfs_alloc_vextent(&args);
 566         if (error)
 567                 goto error0;
 568
 569         if (args.fsbno == NULLFSBLOCK && args.minleft) {
 570                 /*
 571                  * Could not find an AG with enough free space to satisfy
 572                  * a full btree split.  Try again without minleft and if
 573                  * successful activate the lowspace algorithm.
 574                  */
 575                 args.fsbno = 0;
 576                 args.type = XFS_ALLOCTYPE_FIRST_AG;
 577                 args.minleft = 0;
 578                 error = xfs_alloc_vextent(&args);
 579                 if (error)
 580                         goto error0;
 581                 cur->bc_private.b.flist->xbf_low = 1;
 582         }
 583         if (args.fsbno == NULLFSBLOCK) {
 584                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
 585                 *stat = 0;
 586                 return 0;
 587         }
 588         ASSERT(args.len == 1);
 589         cur->bc_private.b.firstblock = args.fsbno;
 590         cur->bc_private.b.allocated++;
 591         cur->bc_private.b.ip->i_d.di_nblocks++;
 592         xfs_trans_log_inode(args.tp, cur->bc_private.b.ip, XFS_ILOG_CORE);
 593         XFS_TRANS_MOD_DQUOT_BYINO(args.mp, args.tp, cur->bc_private.b.ip,
 594                         XFS_TRANS_DQ_BCOUNT, 1L);
 595
 596         new->l = cpu_to_be64(args.fsbno);
 597
 598         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
 599         *stat = 1;
 600         return 0;
 601
 602  error0:
 603         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
 604         return error;
 605 }
 606
 607 STATIC int
 608 xfs_bmbt_free_block(
 609         struct xfs_btree_cur    *cur,
 610         struct xfs_buf          *bp)
 611 {
 612         struct xfs_mount        *mp = cur->bc_mp;
 613         struct xfs_inode        *ip = cur->bc_private.b.ip;
 614         struct xfs_trans        *tp = cur->bc_tp;
 615         xfs_fsblock_t           fsbno = XFS_DADDR_TO_FSB(mp, XFS_BUF_ADDR(bp));
 616
 617         xfs_bmap_add_free(fsbno, 1, cur->bc_private.b.flist, mp);
 618         ip->i_d.di_nblocks--;
 619
 620         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 621         XFS_TRANS_MOD_DQUOT_BYINO(mp, tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
 622         xfs_trans_binval(tp, bp);
 623         return 0;
 624 }
 625
 626 STATIC int
 627 xfs_bmbt_get_minrecs(
 628         struct xfs_btree_cur    *cur,
 629         int                     level)
 630 {
 631         if (level == cur->bc_nlevels - 1) {
 632                 struct xfs_ifork        *ifp;
 633
 634                 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip,
 635                                     cur->bc_private.b.whichfork);
 636
 637                 return xfs_bmbt_maxrecs(cur->bc_mp,
 638                                         ifp->if_broot_bytes, level == 0) / 2;
 639         }
 640
 641         return cur->bc_mp->m_bmap_dmnr[level != 0];
 642 }
 643
 644 int
 645 xfs_bmbt_get_maxrecs(
 646         struct xfs_btree_cur    *cur,
 647         int                     level)
 648 {
 649         if (level == cur->bc_nlevels - 1) {
 650                 struct xfs_ifork        *ifp;
 651
 652                 ifp = XFS_IFORK_PTR(cur->bc_private.b.ip,
 653                                     cur->bc_private.b.whichfork);
 654
 655                 return xfs_bmbt_maxrecs(cur->bc_mp,
 656                                         ifp->if_broot_bytes, level == 0);
 657         }
 658
 659         return cur->bc_mp->m_bmap_dmxr[level != 0];
 660
 661 }
 662
 663 /*
 664  * Get the maximum records we could store in the on-disk format.
 665  *
 666  * For non-root nodes this is equivalent to xfs_bmbt_get_maxrecs, but
 667  * for the root node this checks the available space in the dinode fork
 668  * so that we can resize the in-memory buffer to match it.  After a
 669  * resize to the maximum size this function returns the same value
 670  * as xfs_bmbt_get_maxrecs for the root node, too.
 671  */
 672 STATIC int
 673 xfs_bmbt_get_dmaxrecs(
 674         struct xfs_btree_cur    *cur,
 675         int                     level)
 676 {
 677         if (level != cur->bc_nlevels - 1)
 678                 return cur->bc_mp->m_bmap_dmxr[level != 0];
 679         return xfs_bmdr_maxrecs(cur->bc_mp, cur->bc_private.b.forksize,
 680                                 level == 0);
 681 }
 682
 683 STATIC void
 684 xfs_bmbt_init_key_from_rec(
 685         union xfs_btree_key     *key,
 686         union xfs_btree_rec     *rec)
 687 {
 688         key->bmbt.br_startoff =
 689                 cpu_to_be64(xfs_bmbt_disk_get_startoff(&rec->bmbt));
 690 }
 691
 692 STATIC void
 693 xfs_bmbt_init_rec_from_key(
 694         union xfs_btree_key     *key,
 695         union xfs_btree_rec     *rec)
 696 {
 697         ASSERT(key->bmbt.br_startoff != 0);
 698
 699         xfs_bmbt_disk_set_allf(&rec->bmbt, be64_to_cpu(key->bmbt.br_startoff),
 700                                0, 0, XFS_EXT_NORM);
 701 }
 702
 703 STATIC void
 704 xfs_bmbt_init_rec_from_cur(
 705         struct xfs_btree_cur    *cur,
 706         union xfs_btree_rec     *rec)
 707 {
 708         xfs_bmbt_disk_set_all(&rec->bmbt, &cur->bc_rec.b);
 709 }
 710
 711 STATIC void
 712 xfs_bmbt_init_ptr_from_cur(
 713         struct xfs_btree_cur    *cur,
 714         union xfs_btree_ptr     *ptr)
 715 {
 716         ptr->l = 0;
 717 }
 718
 719 STATIC __int64_t
 720 xfs_bmbt_key_diff(
 721         struct xfs_btree_cur    *cur,
 722         union xfs_btree_key     *key)
 723 {
 724         return (__int64_t)be64_to_cpu(key->bmbt.br_startoff) -
 725                                       cur->bc_rec.b.br_startoff;
 726 }
 727
 728 #ifdef DEBUG
 729 STATIC int
 730 xfs_bmbt_keys_inorder(
 731         struct xfs_btree_cur    *cur,
 732         union xfs_btree_key     *k1,
 733         union xfs_btree_key     *k2)
 734 {
 735         return be64_to_cpu(k1->bmbt.br_startoff) <
 736                 be64_to_cpu(k2->bmbt.br_startoff);
 737 }
 738
 739 STATIC int
 740 xfs_bmbt_recs_inorder(
 741         struct xfs_btree_cur    *cur,
 742         union xfs_btree_rec     *r1,
 743         union xfs_btree_rec     *r2)
 744 {
 745         return xfs_bmbt_disk_get_startoff(&r1->bmbt) +
 746                 xfs_bmbt_disk_get_blockcount(&r1->bmbt) <=
 747                 xfs_bmbt_disk_get_startoff(&r2->bmbt);
 748 }
 749 #endif  /* DEBUG */
 750
 751 #ifdef XFS_BTREE_TRACE
 752 ktrace_t        *xfs_bmbt_trace_buf;
 753
 754 STATIC void
 755 xfs_bmbt_trace_enter(
 756         struct xfs_btree_cur    *cur,
 757         const char              *func,
 758         char                    *s,
 759         int                     type,
 760         int                     line,
 761         __psunsigned_t          a0,
 762         __psunsigned_t          a1,
 763         __psunsigned_t          a2,
 764         __psunsigned_t          a3,
 765         __psunsigned_t          a4,
 766         __psunsigned_t          a5,
 767         __psunsigned_t          a6,
 768         __psunsigned_t          a7,
 769         __psunsigned_t          a8,
 770         __psunsigned_t          a9,
 771         __psunsigned_t          a10)
 772 {
 773         struct xfs_inode        *ip = cur->bc_private.b.ip;
 774         int                     whichfork = cur->bc_private.b.whichfork;
 775
 776         ktrace_enter(xfs_bmbt_trace_buf,
 777                 (void *)((__psint_t)type | (whichfork << 8) | (line << 16)),
 778                 (void *)func, (void *)s, (void *)ip, (void *)cur,
 779                 (void *)a0, (void *)a1, (void *)a2, (void *)a3,
 780                 (void *)a4, (void *)a5, (void *)a6, (void *)a7,
 781                 (void *)a8, (void *)a9, (void *)a10);
 782         ktrace_enter(ip->i_btrace,
 783                 (void *)((__psint_t)type | (whichfork << 8) | (line << 16)),
 784                 (void *)func, (void *)s, (void *)ip, (void *)cur,
 785                 (void *)a0, (void *)a1, (void *)a2, (void *)a3,
 786                 (void *)a4, (void *)a5, (void *)a6, (void *)a7,
 787                 (void *)a8, (void *)a9, (void *)a10);
 788 }
 789
 790 STATIC void
 791 xfs_bmbt_trace_cursor(
 792         struct xfs_btree_cur    *cur,
 793         __uint32_t              *s0,
 794         __uint64_t              *l0,
 795         __uint64_t              *l1)
 796 {
 797         struct xfs_bmbt_rec_host r;
 798
 799         xfs_bmbt_set_all(&r, &cur->bc_rec.b);
 800
 801         *s0 = (cur->bc_nlevels << 24) |
 802               (cur->bc_private.b.flags << 16) |
 803                cur->bc_private.b.allocated;
 804         *l0 = r.l0;
 805         *l1 = r.l1;
 806 }
 807
 808 STATIC void
 809 xfs_bmbt_trace_key(
 810         struct xfs_btree_cur    *cur,
 811         union xfs_btree_key     *key,
 812         __uint64_t              *l0,
 813         __uint64_t              *l1)
 814 {
 815         *l0 = be64_to_cpu(key->bmbt.br_startoff);
 816         *l1 = 0;
 817 }
 818
 819 STATIC void
 820 xfs_bmbt_trace_record(
 821         struct xfs_btree_cur    *cur,
 822         union xfs_btree_rec     *rec,
 823         __uint64_t              *l0,
 824         __uint64_t              *l1,
 825         __uint64_t              *l2)
 826 {
 827         struct xfs_bmbt_irec    irec;
 828
 829         xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
 830         *l0 = irec.br_startoff;
 831         *l1 = irec.br_startblock;
 832         *l2 = irec.br_blockcount;
 833 }
 834 #endif /* XFS_BTREE_TRACE */
 835
 836 static const struct xfs_btree_ops xfs_bmbt_ops = {
 837         .rec_len                = sizeof(xfs_bmbt_rec_t),
 838         .key_len                = sizeof(xfs_bmbt_key_t),
 839
 840         .dup_cursor             = xfs_bmbt_dup_cursor,
 841         .update_cursor          = xfs_bmbt_update_cursor,
 842         .alloc_block            = xfs_bmbt_alloc_block,
 843         .free_block             = xfs_bmbt_free_block,
 844         .get_maxrecs            = xfs_bmbt_get_maxrecs,
 845         .get_minrecs            = xfs_bmbt_get_minrecs,
 846         .get_dmaxrecs           = xfs_bmbt_get_dmaxrecs,
 847         .init_key_from_rec      = xfs_bmbt_init_key_from_rec,
 848         .init_rec_from_key      = xfs_bmbt_init_rec_from_key,
 849         .init_rec_from_cur      = xfs_bmbt_init_rec_from_cur,
 850         .init_ptr_from_cur      = xfs_bmbt_init_ptr_from_cur,
 851         .key_diff               = xfs_bmbt_key_diff,
 852
 853 #ifdef DEBUG
 854         .keys_inorder           = xfs_bmbt_keys_inorder,
 855         .recs_inorder           = xfs_bmbt_recs_inorder,
 856 #endif
 857
 858 #ifdef XFS_BTREE_TRACE
 859         .trace_enter            = xfs_bmbt_trace_enter,
 860         .trace_cursor           = xfs_bmbt_trace_cursor,
 861         .trace_key              = xfs_bmbt_trace_key,
 862         .trace_record           = xfs_bmbt_trace_record,
 863 #endif
 864 };
 865
 866 /*
 867  * Allocate a new bmap btree cursor.
 868  */
 869 struct xfs_btree_cur *                          /* new bmap btree cursor */
 870 xfs_bmbt_init_cursor(
 871         struct xfs_mount        *mp,            /* file system mount point */
 872         struct xfs_trans        *tp,            /* transaction pointer */
 873         struct xfs_inode        *ip,            /* inode owning the btree */
 874         int                     whichfork)      /* data or attr fork */
 875 {
 876         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
 877         struct xfs_btree_cur    *cur;
 878
 879         cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
 880
 881         cur->bc_tp = tp;
 882         cur->bc_mp = mp;
 883         cur->bc_nlevels = be16_to_cpu(ifp->if_broot->bb_level) + 1;
 884         cur->bc_btnum = XFS_BTNUM_BMAP;
 885         cur->bc_blocklog = mp->m_sb.sb_blocklog;
 886
 887         cur->bc_ops = &xfs_bmbt_ops;
 888         cur->bc_flags = XFS_BTREE_LONG_PTRS | XFS_BTREE_ROOT_IN_INODE;
 889
 890         cur->bc_private.b.forksize = XFS_IFORK_SIZE(ip, whichfork);
 891         cur->bc_private.b.ip = ip;
 892         cur->bc_private.b.firstblock = NULLFSBLOCK;
 893         cur->bc_private.b.flist = NULL;
 894         cur->bc_private.b.allocated = 0;
 895         cur->bc_private.b.flags = 0;
 896         cur->bc_private.b.whichfork = whichfork;
 897
 898         return cur;
 899 }
 900
 901 /*
 902  * Calculate number of records in a bmap btree block.
 903  */
 904 int
 905 xfs_bmbt_maxrecs(
 906         struct xfs_mount        *mp,
 907         int                     blocklen,
 908         int                     leaf)
 909 {
 910         blocklen -= XFS_BMBT_BLOCK_LEN(mp);
 911
 912         if (leaf)
 913                 return blocklen / sizeof(xfs_bmbt_rec_t);
 914         return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t));
 915 }
 916
 917 /*
 918  * Calculate number of records in a bmap btree inode root.
 919  */
 920 int
 921 xfs_bmdr_maxrecs(
 922         struct xfs_mount        *mp,
 923         int                     blocklen,
 924         int                     leaf)
 925 {
 926         blocklen -= sizeof(xfs_bmdr_block_t);
 927
 928         if (leaf)
 929                 return blocklen / sizeof(xfs_bmdr_rec_t);
 930         return blocklen / (sizeof(xfs_bmdr_key_t) + sizeof(xfs_bmdr_ptr_t));
 931 }