fs/xfs/xfs_rtalloc.c

   1 /*
   2  * Copyright (c) 2000-2005 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_mount.h"
  29 #include "xfs_bmap_btree.h"
  30 #include "xfs_dinode.h"
  31 #include "xfs_inode.h"
  32 #include "xfs_alloc.h"
  33 #include "xfs_bmap.h"
  34 #include "xfs_rtalloc.h"
  35 #include "xfs_fsops.h"
  36 #include "xfs_error.h"
  37 #include "xfs_rw.h"
  38 #include "xfs_inode_item.h"
  39 #include "xfs_trans_space.h"
  40 #include "xfs_utils.h"
  41 #include "xfs_trace.h"
  42
  43
  44 /*
  45  * Prototypes for internal functions.
  46  */
  47
  48
  49 STATIC int xfs_rtallocate_range(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  50                 xfs_extlen_t, xfs_buf_t **, xfs_fsblock_t *);
  51 STATIC int xfs_rtany_summary(xfs_mount_t *, xfs_trans_t *, int, int,
  52                 xfs_rtblock_t, xfs_buf_t **, xfs_fsblock_t *, int *);
  53 STATIC int xfs_rtcheck_range(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  54                 xfs_extlen_t, int, xfs_rtblock_t *, int *);
  55 STATIC int xfs_rtfind_back(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  56                 xfs_rtblock_t, xfs_rtblock_t *);
  57 STATIC int xfs_rtfind_forw(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  58                 xfs_rtblock_t, xfs_rtblock_t *);
  59 STATIC int xfs_rtget_summary( xfs_mount_t *, xfs_trans_t *, int,
  60                 xfs_rtblock_t, xfs_buf_t **, xfs_fsblock_t *, xfs_suminfo_t *);
  61 STATIC int xfs_rtmodify_range(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  62                 xfs_extlen_t, int);
  63 STATIC int xfs_rtmodify_summary(xfs_mount_t *, xfs_trans_t *, int,
  64                 xfs_rtblock_t, int, xfs_buf_t **, xfs_fsblock_t *);
  65
  66 /*
  67  * Internal functions.
  68  */
  69
  70 /*
  71  * Allocate space to the bitmap or summary file, and zero it, for growfs.
  72  */
  73 STATIC int                              /* error */
  74 xfs_growfs_rt_alloc(
  75         xfs_mount_t     *mp,            /* file system mount point */
  76         xfs_extlen_t    oblocks,        /* old count of blocks */
  77         xfs_extlen_t    nblocks,        /* new count of blocks */
  78         xfs_ino_t       ino)            /* inode number (bitmap/summary) */
  79 {
  80         xfs_fileoff_t   bno;            /* block number in file */
  81         xfs_buf_t       *bp;            /* temporary buffer for zeroing */
  82         int             committed;      /* transaction committed flag */
  83         xfs_daddr_t     d;              /* disk block address */
  84         int             error;          /* error return value */
  85         xfs_fsblock_t   firstblock;     /* first block allocated in xaction */
  86         xfs_bmap_free_t flist;          /* list of freed blocks */
  87         xfs_fsblock_t   fsbno;          /* filesystem block for bno */
  88         xfs_inode_t     *ip;            /* pointer to incore inode */
  89         xfs_bmbt_irec_t map;            /* block map output */
  90         int             nmap;           /* number of block maps */
  91         int             resblks;        /* space reservation */
  92
  93         /*
  94          * Allocate space to the file, as necessary.
  95          */
  96         while (oblocks < nblocks) {
  97                 int             cancelflags = 0;
  98                 xfs_trans_t     *tp;
  99
 100                 tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_ALLOC);
 101                 resblks = XFS_GROWFSRT_SPACE_RES(mp, nblocks - oblocks);
 102                 /*
 103                  * Reserve space & log for one extent added to the file.
 104                  */
 105                 if ((error = xfs_trans_reserve(tp, resblks,
 106                                 XFS_GROWRTALLOC_LOG_RES(mp), 0,
 107                                 XFS_TRANS_PERM_LOG_RES,
 108                                 XFS_DEFAULT_PERM_LOG_COUNT)))
 109                         goto error_cancel;
 110                 cancelflags = XFS_TRANS_RELEASE_LOG_RES;
 111                 /*
 112                  * Lock the inode.
 113                  */
 114                 if ((error = xfs_trans_iget(mp, tp, ino, 0,
 115                                                 XFS_ILOCK_EXCL, &ip)))
 116                         goto error_cancel;
 117                 xfs_bmap_init(&flist, &firstblock);
 118                 /*
 119                  * Allocate blocks to the bitmap file.
 120                  */
 121                 nmap = 1;
 122                 cancelflags |= XFS_TRANS_ABORT;
 123                 error = xfs_bmapi(tp, ip, oblocks, nblocks - oblocks,
 124                         XFS_BMAPI_WRITE | XFS_BMAPI_METADATA, &firstblock,
 125                         resblks, &map, &nmap, &flist);
 126                 if (!error && nmap < 1)
 127                         error = XFS_ERROR(ENOSPC);
 128                 if (error)
 129                         goto error_cancel;
 130                 /*
 131                  * Free any blocks freed up in the transaction, then commit.
 132                  */
 133                 error = xfs_bmap_finish(&tp, &flist, &committed);
 134                 if (error)
 135                         goto error_cancel;
 136                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 137                 if (error)
 138                         goto error;
 139                 /*
 140                  * Now we need to clear the allocated blocks.
 141                  * Do this one block per transaction, to keep it simple.
 142                  */
 143                 cancelflags = 0;
 144                 for (bno = map.br_startoff, fsbno = map.br_startblock;
 145                      bno < map.br_startoff + map.br_blockcount;
 146                      bno++, fsbno++) {
 147                         tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_ZERO);
 148                         /*
 149                          * Reserve log for one block zeroing.
 150                          */
 151                         if ((error = xfs_trans_reserve(tp, 0,
 152                                         XFS_GROWRTZERO_LOG_RES(mp), 0, 0, 0)))
 153                                 goto error_cancel;
 154                         /*
 155                          * Lock the bitmap inode.
 156                          */
 157                         if ((error = xfs_trans_iget(mp, tp, ino, 0,
 158                                                         XFS_ILOCK_EXCL, &ip)))
 159                                 goto error_cancel;
 160                         /*
 161                          * Get a buffer for the block.
 162                          */
 163                         d = XFS_FSB_TO_DADDR(mp, fsbno);
 164                         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
 165                                 mp->m_bsize, 0);
 166                         if (bp == NULL) {
 167                                 error = XFS_ERROR(EIO);
 168 error_cancel:
 169                                 xfs_trans_cancel(tp, cancelflags);
 170                                 goto error;
 171                         }
 172                         memset(XFS_BUF_PTR(bp), 0, mp->m_sb.sb_blocksize);
 173                         xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
 174                         /*
 175                          * Commit the transaction.
 176                          */
 177                         error = xfs_trans_commit(tp, 0);
 178                         if (error)
 179                                 goto error;
 180                 }
 181                 /*
 182                  * Go on to the next extent, if any.
 183                  */
 184                 oblocks = map.br_startoff + map.br_blockcount;
 185         }
 186         return 0;
 187 error:
 188         return error;
 189 }
 190
 191 /*
 192  * Attempt to allocate an extent minlen<=len<=maxlen starting from
 193  * bitmap block bbno.  If we don't get maxlen then use prod to trim
 194  * the length, if given.  Returns error; returns starting block in *rtblock.
 195  * The lengths are all in rtextents.
 196  */
 197 STATIC int                              /* error */
 198 xfs_rtallocate_extent_block(
 199         xfs_mount_t     *mp,            /* file system mount point */
 200         xfs_trans_t     *tp,            /* transaction pointer */
 201         xfs_rtblock_t   bbno,           /* bitmap block number */
 202         xfs_extlen_t    minlen,         /* minimum length to allocate */
 203         xfs_extlen_t    maxlen,         /* maximum length to allocate */
 204         xfs_extlen_t    *len,           /* out: actual length allocated */
 205         xfs_rtblock_t   *nextp,         /* out: next block to try */
 206         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 207         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 208         xfs_extlen_t    prod,           /* extent product factor */
 209         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
 210 {
 211         xfs_rtblock_t   besti;          /* best rtblock found so far */
 212         xfs_rtblock_t   bestlen;        /* best length found so far */
 213         xfs_rtblock_t   end;            /* last rtblock in chunk */
 214         int             error;          /* error value */
 215         xfs_rtblock_t   i;              /* current rtblock trying */
 216         xfs_rtblock_t   next;           /* next rtblock to try */
 217         int             stat;           /* status from internal calls */
 218
 219         /*
 220          * Loop over all the extents starting in this bitmap block,
 221          * looking for one that's long enough.
 222          */
 223         for (i = XFS_BLOCKTOBIT(mp, bbno), besti = -1, bestlen = 0,
 224                 end = XFS_BLOCKTOBIT(mp, bbno + 1) - 1;
 225              i <= end;
 226              i++) {
 227                 /*
 228                  * See if there's a free extent of maxlen starting at i.
 229                  * If it's not so then next will contain the first non-free.
 230                  */
 231                 error = xfs_rtcheck_range(mp, tp, i, maxlen, 1, &next, &stat);
 232                 if (error) {
 233                         return error;
 234                 }
 235                 if (stat) {
 236                         /*
 237                          * i for maxlen is all free, allocate and return that.
 238                          */
 239                         error = xfs_rtallocate_range(mp, tp, i, maxlen, rbpp,
 240                                 rsb);
 241                         if (error) {
 242                                 return error;
 243                         }
 244                         *len = maxlen;
 245                         *rtblock = i;
 246                         return 0;
 247                 }
 248                 /*
 249                  * In the case where we have a variable-sized allocation
 250                  * request, figure out how big this free piece is,
 251                  * and if it's big enough for the minimum, and the best
 252                  * so far, remember it.
 253                  */
 254                 if (minlen < maxlen) {
 255                         xfs_rtblock_t   thislen;        /* this extent size */
 256
 257                         thislen = next - i;
 258                         if (thislen >= minlen && thislen > bestlen) {
 259                                 besti = i;
 260                                 bestlen = thislen;
 261                         }
 262                 }
 263                 /*
 264                  * If not done yet, find the start of the next free space.
 265                  */
 266                 if (next < end) {
 267                         error = xfs_rtfind_forw(mp, tp, next, end, &i);
 268                         if (error) {
 269                                 return error;
 270                         }
 271                 } else
 272                         break;
 273         }
 274         /*
 275          * Searched the whole thing & didn't find a maxlen free extent.
 276          */
 277         if (minlen < maxlen && besti != -1) {
 278                 xfs_extlen_t    p;      /* amount to trim length by */
 279
 280                 /*
 281                  * If size should be a multiple of prod, make that so.
 282                  */
 283                 if (prod > 1 && (p = do_mod(bestlen, prod)))
 284                         bestlen -= p;
 285                 /*
 286                  * Allocate besti for bestlen & return that.
 287                  */
 288                 error = xfs_rtallocate_range(mp, tp, besti, bestlen, rbpp, rsb);
 289                 if (error) {
 290                         return error;
 291                 }
 292                 *len = bestlen;
 293                 *rtblock = besti;
 294                 return 0;
 295         }
 296         /*
 297          * Allocation failed.  Set *nextp to the next block to try.
 298          */
 299         *nextp = next;
 300         *rtblock = NULLRTBLOCK;
 301         return 0;
 302 }
 303
 304 /*
 305  * Allocate an extent of length minlen<=len<=maxlen, starting at block
 306  * bno.  If we don't get maxlen then use prod to trim the length, if given.
 307  * Returns error; returns starting block in *rtblock.
 308  * The lengths are all in rtextents.
 309  */
 310 STATIC int                              /* error */
 311 xfs_rtallocate_extent_exact(
 312         xfs_mount_t     *mp,            /* file system mount point */
 313         xfs_trans_t     *tp,            /* transaction pointer */
 314         xfs_rtblock_t   bno,            /* starting block number to allocate */
 315         xfs_extlen_t    minlen,         /* minimum length to allocate */
 316         xfs_extlen_t    maxlen,         /* maximum length to allocate */
 317         xfs_extlen_t    *len,           /* out: actual length allocated */
 318         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 319         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 320         xfs_extlen_t    prod,           /* extent product factor */
 321         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
 322 {
 323         int             error;          /* error value */
 324         xfs_extlen_t    i;              /* extent length trimmed due to prod */
 325         int             isfree;         /* extent is free */
 326         xfs_rtblock_t   next;           /* next block to try (dummy) */
 327
 328         ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 329         /*
 330          * Check if the range in question (for maxlen) is free.
 331          */
 332         error = xfs_rtcheck_range(mp, tp, bno, maxlen, 1, &next, &isfree);
 333         if (error) {
 334                 return error;
 335         }
 336         if (isfree) {
 337                 /*
 338                  * If it is, allocate it and return success.
 339                  */
 340                 error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
 341                 if (error) {
 342                         return error;
 343                 }
 344                 *len = maxlen;
 345                 *rtblock = bno;
 346                 return 0;
 347         }
 348         /*
 349          * If not, allocate what there is, if it's at least minlen.
 350          */
 351         maxlen = next - bno;
 352         if (maxlen < minlen) {
 353                 /*
 354                  * Failed, return failure status.
 355                  */
 356                 *rtblock = NULLRTBLOCK;
 357                 return 0;
 358         }
 359         /*
 360          * Trim off tail of extent, if prod is specified.
 361          */
 362         if (prod > 1 && (i = maxlen % prod)) {
 363                 maxlen -= i;
 364                 if (maxlen < minlen) {
 365                         /*
 366                          * Now we can't do it, return failure status.
 367                          */
 368                         *rtblock = NULLRTBLOCK;
 369                         return 0;
 370                 }
 371         }
 372         /*
 373          * Allocate what we can and return it.
 374          */
 375         error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
 376         if (error) {
 377                 return error;
 378         }
 379         *len = maxlen;
 380         *rtblock = bno;
 381         return 0;
 382 }
 383
 384 /*
 385  * Allocate an extent of length minlen<=len<=maxlen, starting as near
 386  * to bno as possible.  If we don't get maxlen then use prod to trim
 387  * the length, if given.  The lengths are all in rtextents.
 388  */
 389 STATIC int                              /* error */
 390 xfs_rtallocate_extent_near(
 391         xfs_mount_t     *mp,            /* file system mount point */
 392         xfs_trans_t     *tp,            /* transaction pointer */
 393         xfs_rtblock_t   bno,            /* starting block number to allocate */
 394         xfs_extlen_t    minlen,         /* minimum length to allocate */
 395         xfs_extlen_t    maxlen,         /* maximum length to allocate */
 396         xfs_extlen_t    *len,           /* out: actual length allocated */
 397         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 398         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 399         xfs_extlen_t    prod,           /* extent product factor */
 400         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
 401 {
 402         int             any;            /* any useful extents from summary */
 403         xfs_rtblock_t   bbno;           /* bitmap block number */
 404         int             error;          /* error value */
 405         int             i;              /* bitmap block offset (loop control) */
 406         int             j;              /* secondary loop control */
 407         int             log2len;        /* log2 of minlen */
 408         xfs_rtblock_t   n;              /* next block to try */
 409         xfs_rtblock_t   r;              /* result block */
 410
 411         ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 412         /*
 413          * If the block number given is off the end, silently set it to
 414          * the last block.
 415          */
 416         if (bno >= mp->m_sb.sb_rextents)
 417                 bno = mp->m_sb.sb_rextents - 1;
 418         /*
 419          * Try the exact allocation first.
 420          */
 421         error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, len,
 422                 rbpp, rsb, prod, &r);
 423         if (error) {
 424                 return error;
 425         }
 426         /*
 427          * If the exact allocation worked, return that.
 428          */
 429         if (r != NULLRTBLOCK) {
 430                 *rtblock = r;
 431                 return 0;
 432         }
 433         bbno = XFS_BITTOBLOCK(mp, bno);
 434         i = 0;
 435         ASSERT(minlen != 0);
 436         log2len = xfs_highbit32(minlen);
 437         /*
 438          * Loop over all bitmap blocks (bbno + i is current block).
 439          */
 440         for (;;) {
 441                 /*
 442                  * Get summary information of extents of all useful levels
 443                  * starting in this bitmap block.
 444                  */
 445                 error = xfs_rtany_summary(mp, tp, log2len, mp->m_rsumlevels - 1,
 446                         bbno + i, rbpp, rsb, &any);
 447                 if (error) {
 448                         return error;
 449                 }
 450                 /*
 451                  * If there are any useful extents starting here, try
 452                  * allocating one.
 453                  */
 454                 if (any) {
 455                         /*
 456                          * On the positive side of the starting location.
 457                          */
 458                         if (i >= 0) {
 459                                 /*
 460                                  * Try to allocate an extent starting in
 461                                  * this block.
 462                                  */
 463                                 error = xfs_rtallocate_extent_block(mp, tp,
 464                                         bbno + i, minlen, maxlen, len, &n, rbpp,
 465                                         rsb, prod, &r);
 466                                 if (error) {
 467                                         return error;
 468                                 }
 469                                 /*
 470                                  * If it worked, return it.
 471                                  */
 472                                 if (r != NULLRTBLOCK) {
 473                                         *rtblock = r;
 474                                         return 0;
 475                                 }
 476                         }
 477                         /*
 478                          * On the negative side of the starting location.
 479                          */
 480                         else {          /* i < 0 */
 481                                 /*
 482                                  * Loop backwards through the bitmap blocks from
 483                                  * the starting point-1 up to where we are now.
 484                                  * There should be an extent which ends in this
 485                                  * bitmap block and is long enough.
 486                                  */
 487                                 for (j = -1; j > i; j--) {
 488                                         /*
 489                                          * Grab the summary information for
 490                                          * this bitmap block.
 491                                          */
 492                                         error = xfs_rtany_summary(mp, tp,
 493                                                 log2len, mp->m_rsumlevels - 1,
 494                                                 bbno + j, rbpp, rsb, &any);
 495                                         if (error) {
 496                                                 return error;
 497                                         }
 498                                         /*
 499                                          * If there's no extent given in the
 500                                          * summary that means the extent we
 501                                          * found must carry over from an
 502                                          * earlier block.  If there is an
 503                                          * extent given, we've already tried
 504                                          * that allocation, don't do it again.
 505                                          */
 506                                         if (any)
 507                                                 continue;
 508                                         error = xfs_rtallocate_extent_block(mp,
 509                                                 tp, bbno + j, minlen, maxlen,
 510                                                 len, &n, rbpp, rsb, prod, &r);
 511                                         if (error) {
 512                                                 return error;
 513                                         }
 514                                         /*
 515                                          * If it works, return the extent.
 516                                          */
 517                                         if (r != NULLRTBLOCK) {
 518                                                 *rtblock = r;
 519                                                 return 0;
 520                                         }
 521                                 }
 522                                 /*
 523                                  * There weren't intervening bitmap blocks
 524                                  * with a long enough extent, or the
 525                                  * allocation didn't work for some reason
 526                                  * (i.e. it's a little * too short).
 527                                  * Try to allocate from the summary block
 528                                  * that we found.
 529                                  */
 530                                 error = xfs_rtallocate_extent_block(mp, tp,
 531                                         bbno + i, minlen, maxlen, len, &n, rbpp,
 532                                         rsb, prod, &r);
 533                                 if (error) {
 534                                         return error;
 535                                 }
 536                                 /*
 537                                  * If it works, return the extent.
 538                                  */
 539                                 if (r != NULLRTBLOCK) {
 540                                         *rtblock = r;
 541                                         return 0;
 542                                 }
 543                         }
 544                 }
 545                 /*
 546                  * Loop control.  If we were on the positive side, and there's
 547                  * still more blocks on the negative side, go there.
 548                  */
 549                 if (i > 0 && (int)bbno - i >= 0)
 550                         i = -i;
 551                 /*
 552                  * If positive, and no more negative, but there are more
 553                  * positive, go there.
 554                  */
 555                 else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
 556                         i++;
 557                 /*
 558                  * If negative or 0 (just started), and there are positive
 559                  * blocks to go, go there.  The 0 case moves to block 1.
 560                  */
 561                 else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
 562                         i = 1 - i;
 563                 /*
 564                  * If negative or 0 and there are more negative blocks,
 565                  * go there.
 566                  */
 567                 else if (i <= 0 && (int)bbno + i > 0)
 568                         i--;
 569                 /*
 570                  * Must be done.  Return failure.
 571                  */
 572                 else
 573                         break;
 574         }
 575         *rtblock = NULLRTBLOCK;
 576         return 0;
 577 }
 578
 579 /*
 580  * Allocate an extent of length minlen<=len<=maxlen, with no position
 581  * specified.  If we don't get maxlen then use prod to trim
 582  * the length, if given.  The lengths are all in rtextents.
 583  */
 584 STATIC int                              /* error */
 585 xfs_rtallocate_extent_size(
 586         xfs_mount_t     *mp,            /* file system mount point */
 587         xfs_trans_t     *tp,            /* transaction pointer */
 588         xfs_extlen_t    minlen,         /* minimum length to allocate */
 589         xfs_extlen_t    maxlen,         /* maximum length to allocate */
 590         xfs_extlen_t    *len,           /* out: actual length allocated */
 591         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 592         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 593         xfs_extlen_t    prod,           /* extent product factor */
 594         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
 595 {
 596         int             error;          /* error value */
 597         int             i;              /* bitmap block number */
 598         int             l;              /* level number (loop control) */
 599         xfs_rtblock_t   n;              /* next block to be tried */
 600         xfs_rtblock_t   r;              /* result block number */
 601         xfs_suminfo_t   sum;            /* summary information for extents */
 602
 603         ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 604         ASSERT(maxlen != 0);
 605
 606         /*
 607          * Loop over all the levels starting with maxlen.
 608          * At each level, look at all the bitmap blocks, to see if there
 609          * are extents starting there that are long enough (>= maxlen).
 610          * Note, only on the initial level can the allocation fail if
 611          * the summary says there's an extent.
 612          */
 613         for (l = xfs_highbit32(maxlen); l < mp->m_rsumlevels; l++) {
 614                 /*
 615                  * Loop over all the bitmap blocks.
 616                  */
 617                 for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
 618                         /*
 619                          * Get the summary for this level/block.
 620                          */
 621                         error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
 622                                 &sum);
 623                         if (error) {
 624                                 return error;
 625                         }
 626                         /*
 627                          * Nothing there, on to the next block.
 628                          */
 629                         if (!sum)
 630                                 continue;
 631                         /*
 632                          * Try allocating the extent.
 633                          */
 634                         error = xfs_rtallocate_extent_block(mp, tp, i, maxlen,
 635                                 maxlen, len, &n, rbpp, rsb, prod, &r);
 636                         if (error) {
 637                                 return error;
 638                         }
 639                         /*
 640                          * If it worked, return that.
 641                          */
 642                         if (r != NULLRTBLOCK) {
 643                                 *rtblock = r;
 644                                 return 0;
 645                         }
 646                         /*
 647                          * If the "next block to try" returned from the
 648                          * allocator is beyond the next bitmap block,
 649                          * skip to that bitmap block.
 650                          */
 651                         if (XFS_BITTOBLOCK(mp, n) > i + 1)
 652                                 i = XFS_BITTOBLOCK(mp, n) - 1;
 653                 }
 654         }
 655         /*
 656          * Didn't find any maxlen blocks.  Try smaller ones, unless
 657          * we're asking for a fixed size extent.
 658          */
 659         if (minlen > --maxlen) {
 660                 *rtblock = NULLRTBLOCK;
 661                 return 0;
 662         }
 663         ASSERT(minlen != 0);
 664         ASSERT(maxlen != 0);
 665
 666         /*
 667          * Loop over sizes, from maxlen down to minlen.
 668          * This time, when we do the allocations, allow smaller ones
 669          * to succeed.
 670          */
 671         for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
 672                 /*
 673                  * Loop over all the bitmap blocks, try an allocation
 674                  * starting in that block.
 675                  */
 676                 for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
 677                         /*
 678                          * Get the summary information for this level/block.
 679                          */
 680                         error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
 681                                                   &sum);
 682                         if (error) {
 683                                 return error;
 684                         }
 685                         /*
 686                          * If nothing there, go on to next.
 687                          */
 688                         if (!sum)
 689                                 continue;
 690                         /*
 691                          * Try the allocation.  Make sure the specified
 692                          * minlen/maxlen are in the possible range for
 693                          * this summary level.
 694                          */
 695                         error = xfs_rtallocate_extent_block(mp, tp, i,
 696                                         XFS_RTMAX(minlen, 1 << l),
 697                                         XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
 698                                         len, &n, rbpp, rsb, prod, &r);
 699                         if (error) {
 700                                 return error;
 701                         }
 702                         /*
 703                          * If it worked, return that extent.
 704                          */
 705                         if (r != NULLRTBLOCK) {
 706                                 *rtblock = r;
 707                                 return 0;
 708                         }
 709                         /*
 710                          * If the "next block to try" returned from the
 711                          * allocator is beyond the next bitmap block,
 712                          * skip to that bitmap block.
 713                          */
 714                         if (XFS_BITTOBLOCK(mp, n) > i + 1)
 715                                 i = XFS_BITTOBLOCK(mp, n) - 1;
 716                 }
 717         }
 718         /*
 719          * Got nothing, return failure.
 720          */
 721         *rtblock = NULLRTBLOCK;
 722         return 0;
 723 }
 724
 725 /*
 726  * Mark an extent specified by start and len allocated.
 727  * Updates all the summary information as well as the bitmap.
 728  */
 729 STATIC int                              /* error */
 730 xfs_rtallocate_range(
 731         xfs_mount_t     *mp,            /* file system mount point */
 732         xfs_trans_t     *tp,            /* transaction pointer */
 733         xfs_rtblock_t   start,          /* start block to allocate */
 734         xfs_extlen_t    len,            /* length to allocate */
 735         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 736         xfs_fsblock_t   *rsb)           /* in/out: summary block number */
 737 {
 738         xfs_rtblock_t   end;            /* end of the allocated extent */
 739         int             error;          /* error value */
 740         xfs_rtblock_t   postblock;      /* first block allocated > end */
 741         xfs_rtblock_t   preblock;       /* first block allocated < start */
 742
 743         end = start + len - 1;
 744         /*
 745          * Assume we're allocating out of the middle of a free extent.
 746          * We need to find the beginning and end of the extent so we can
 747          * properly update the summary.
 748          */
 749         error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
 750         if (error) {
 751                 return error;
 752         }
 753         /*
 754          * Find the next allocated block (end of free extent).
 755          */
 756         error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
 757                 &postblock);
 758         if (error) {
 759                 return error;
 760         }
 761         /*
 762          * Decrement the summary information corresponding to the entire
 763          * (old) free extent.
 764          */
 765         error = xfs_rtmodify_summary(mp, tp,
 766                 XFS_RTBLOCKLOG(postblock + 1 - preblock),
 767                 XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
 768         if (error) {
 769                 return error;
 770         }
 771         /*
 772          * If there are blocks not being allocated at the front of the
 773          * old extent, add summary data for them to be free.
 774          */
 775         if (preblock < start) {
 776                 error = xfs_rtmodify_summary(mp, tp,
 777                         XFS_RTBLOCKLOG(start - preblock),
 778                         XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
 779                 if (error) {
 780                         return error;
 781                 }
 782         }
 783         /*
 784          * If there are blocks not being allocated at the end of the
 785          * old extent, add summary data for them to be free.
 786          */
 787         if (postblock > end) {
 788                 error = xfs_rtmodify_summary(mp, tp,
 789                         XFS_RTBLOCKLOG(postblock - end),
 790                         XFS_BITTOBLOCK(mp, end + 1), 1, rbpp, rsb);
 791                 if (error) {
 792                         return error;
 793                 }
 794         }
 795         /*
 796          * Modify the bitmap to mark this extent allocated.
 797          */
 798         error = xfs_rtmodify_range(mp, tp, start, len, 0);
 799         return error;
 800 }
 801
 802 /*
 803  * Return whether there are any free extents in the size range given
 804  * by low and high, for the bitmap block bbno.
 805  */
 806 STATIC int                              /* error */
 807 xfs_rtany_summary(
 808         xfs_mount_t     *mp,            /* file system mount structure */
 809         xfs_trans_t     *tp,            /* transaction pointer */
 810         int             low,            /* low log2 extent size */
 811         int             high,           /* high log2 extent size */
 812         xfs_rtblock_t   bbno,           /* bitmap block number */
 813         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 814         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 815         int             *stat)          /* out: any good extents here? */
 816 {
 817         int             error;          /* error value */
 818         int             log;            /* loop counter, log2 of ext. size */
 819         xfs_suminfo_t   sum;            /* summary data */
 820
 821         /*
 822          * Loop over logs of extent sizes.  Order is irrelevant.
 823          */
 824         for (log = low; log <= high; log++) {
 825                 /*
 826                  * Get one summary datum.
 827                  */
 828                 error = xfs_rtget_summary(mp, tp, log, bbno, rbpp, rsb, &sum);
 829                 if (error) {
 830                         return error;
 831                 }
 832                 /*
 833                  * If there are any, return success.
 834                  */
 835                 if (sum) {
 836                         *stat = 1;
 837                         return 0;
 838                 }
 839         }
 840         /*
 841          * Found nothing, return failure.
 842          */
 843         *stat = 0;
 844         return 0;
 845 }
 846
 847 /*
 848  * Get a buffer for the bitmap or summary file block specified.
 849  * The buffer is returned read and locked.
 850  */
 851 STATIC int                              /* error */
 852 xfs_rtbuf_get(
 853         xfs_mount_t     *mp,            /* file system mount structure */
 854         xfs_trans_t     *tp,            /* transaction pointer */
 855         xfs_rtblock_t   block,          /* block number in bitmap or summary */
 856         int             issum,          /* is summary not bitmap */
 857         xfs_buf_t       **bpp)          /* output: buffer for the block */
 858 {
 859         xfs_buf_t       *bp;            /* block buffer, result */
 860         xfs_daddr_t     d;              /* disk addr of block */
 861         int             error;          /* error value */
 862         xfs_fsblock_t   fsb;            /* fs block number for block */
 863         xfs_inode_t     *ip;            /* bitmap or summary inode */
 864
 865         ip = issum ? mp->m_rsumip : mp->m_rbmip;
 866         /*
 867          * Map from the file offset (block) and inode number to the
 868          * file system block.
 869          */
 870         error = xfs_bmapi_single(tp, ip, XFS_DATA_FORK, &fsb, block);
 871         if (error) {
 872                 return error;
 873         }
 874         ASSERT(fsb != NULLFSBLOCK);
 875         /*
 876          * Convert to disk address for buffer cache.
 877          */
 878         d = XFS_FSB_TO_DADDR(mp, fsb);
 879         /*
 880          * Read the buffer.
 881          */
 882         error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
 883                                    mp->m_bsize, 0, &bp);
 884         if (error) {
 885                 return error;
 886         }
 887         ASSERT(bp && !XFS_BUF_GETERROR(bp));
 888         *bpp = bp;
 889         return 0;
 890 }
 891
 892 #ifdef DEBUG
 893 /*
 894  * Check that the given extent (block range) is allocated already.
 895  */
 896 STATIC int                              /* error */
 897 xfs_rtcheck_alloc_range(
 898         xfs_mount_t     *mp,            /* file system mount point */
 899         xfs_trans_t     *tp,            /* transaction pointer */
 900         xfs_rtblock_t   bno,            /* starting block number of extent */
 901         xfs_extlen_t    len,            /* length of extent */
 902         int             *stat)          /* out: 1 for allocated, 0 for not */
 903 {
 904         xfs_rtblock_t   new;            /* dummy for xfs_rtcheck_range */
 905
 906         return xfs_rtcheck_range(mp, tp, bno, len, 0, &new, stat);
 907 }
 908 #endif
 909
 910 /*
 911  * Check that the given range is either all allocated (val = 0) or
 912  * all free (val = 1).
 913  */
 914 STATIC int                              /* error */
 915 xfs_rtcheck_range(
 916         xfs_mount_t     *mp,            /* file system mount point */
 917         xfs_trans_t     *tp,            /* transaction pointer */
 918         xfs_rtblock_t   start,          /* starting block number of extent */
 919         xfs_extlen_t    len,            /* length of extent */
 920         int             val,            /* 1 for free, 0 for allocated */
 921         xfs_rtblock_t   *new,           /* out: first block not matching */
 922         int             *stat)          /* out: 1 for matches, 0 for not */
 923 {
 924         xfs_rtword_t    *b;             /* current word in buffer */
 925         int             bit;            /* bit number in the word */
 926         xfs_rtblock_t   block;          /* bitmap block number */
 927         xfs_buf_t       *bp;            /* buf for the block */
 928         xfs_rtword_t    *bufp;          /* starting word in buffer */
 929         int             error;          /* error value */
 930         xfs_rtblock_t   i;              /* current bit number rel. to start */
 931         xfs_rtblock_t   lastbit;        /* last useful bit in word */
 932         xfs_rtword_t    mask;           /* mask of relevant bits for value */
 933         xfs_rtword_t    wdiff;          /* difference from wanted value */
 934         int             word;           /* word number in the buffer */
 935
 936         /*
 937          * Compute starting bitmap block number
 938          */
 939         block = XFS_BITTOBLOCK(mp, start);
 940         /*
 941          * Read the bitmap block.
 942          */
 943         error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
 944         if (error) {
 945                 return error;
 946         }
 947         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
 948         /*
 949          * Compute the starting word's address, and starting bit.
 950          */
 951         word = XFS_BITTOWORD(mp, start);
 952         b = &bufp[word];
 953         bit = (int)(start & (XFS_NBWORD - 1));
 954         /*
 955          * 0 (allocated) => all zero's; 1 (free) => all one's.
 956          */
 957         val = -val;
 958         /*
 959          * If not starting on a word boundary, deal with the first
 960          * (partial) word.
 961          */
 962         if (bit) {
 963                 /*
 964                  * Compute first bit not examined.
 965                  */
 966                 lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
 967                 /*
 968                  * Mask of relevant bits.
 969                  */
 970                 mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
 971                 /*
 972                  * Compute difference between actual and desired value.
 973                  */
 974                 if ((wdiff = (*b ^ val) & mask)) {
 975                         /*
 976                          * Different, compute first wrong bit and return.
 977                          */
 978                         xfs_trans_brelse(tp, bp);
 979                         i = XFS_RTLOBIT(wdiff) - bit;
 980                         *new = start + i;
 981                         *stat = 0;
 982                         return 0;
 983                 }
 984                 i = lastbit - bit;
 985                 /*
 986                  * Go on to next block if that's where the next word is
 987                  * and we need the next word.
 988                  */
 989                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
 990                         /*
 991                          * If done with this block, get the next one.
 992                          */
 993                         xfs_trans_brelse(tp, bp);
 994                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
 995                         if (error) {
 996                                 return error;
 997                         }
 998                         b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
 999                         word = 0;
1000                 } else {
1001                         /*
1002                          * Go on to the next word in the buffer.
1003                          */
1004                         b++;
1005                 }
1006         } else {
1007                 /*
1008                  * Starting on a word boundary, no partial word.
1009                  */
1010                 i = 0;
1011         }
1012         /*
1013          * Loop over whole words in buffers.  When we use up one buffer
1014          * we move on to the next one.
1015          */
1016         while (len - i >= XFS_NBWORD) {
1017                 /*
1018                  * Compute difference between actual and desired value.
1019                  */
1020                 if ((wdiff = *b ^ val)) {
1021                         /*
1022                          * Different, compute first wrong bit and return.
1023                          */
1024                         xfs_trans_brelse(tp, bp);
1025                         i += XFS_RTLOBIT(wdiff);
1026                         *new = start + i;
1027                         *stat = 0;
1028                         return 0;
1029                 }
1030                 i += XFS_NBWORD;
1031                 /*
1032                  * Go on to next block if that's where the next word is
1033                  * and we need the next word.
1034                  */
1035                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1036                         /*
1037                          * If done with this block, get the next one.
1038                          */
1039                         xfs_trans_brelse(tp, bp);
1040                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1041                         if (error) {
1042                                 return error;
1043                         }
1044                         b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1045                         word = 0;
1046                 } else {
1047                         /*
1048                          * Go on to the next word in the buffer.
1049                          */
1050                         b++;
1051                 }
1052         }
1053         /*
1054          * If not ending on a word boundary, deal with the last
1055          * (partial) word.
1056          */
1057         if ((lastbit = len - i)) {
1058                 /*
1059                  * Mask of relevant bits.
1060                  */
1061                 mask = ((xfs_rtword_t)1 << lastbit) - 1;
1062                 /*
1063                  * Compute difference between actual and desired value.
1064                  */
1065                 if ((wdiff = (*b ^ val) & mask)) {
1066                         /*
1067                          * Different, compute first wrong bit and return.
1068                          */
1069                         xfs_trans_brelse(tp, bp);
1070                         i += XFS_RTLOBIT(wdiff);
1071                         *new = start + i;
1072                         *stat = 0;
1073                         return 0;
1074                 } else
1075                         i = len;
1076         }
1077         /*
1078          * Successful, return.
1079          */
1080         xfs_trans_brelse(tp, bp);
1081         *new = start + i;
1082         *stat = 1;
1083         return 0;
1084 }
1085
1086 /*
1087  * Copy and transform the summary file, given the old and new
1088  * parameters in the mount structures.
1089  */
1090 STATIC int                              /* error */
1091 xfs_rtcopy_summary(
1092         xfs_mount_t     *omp,           /* old file system mount point */
1093         xfs_mount_t     *nmp,           /* new file system mount point */
1094         xfs_trans_t     *tp)            /* transaction pointer */
1095 {
1096         xfs_rtblock_t   bbno;           /* bitmap block number */
1097         xfs_buf_t       *bp;            /* summary buffer */
1098         int             error;          /* error return value */
1099         int             log;            /* summary level number (log length) */
1100         xfs_suminfo_t   sum;            /* summary data */
1101         xfs_fsblock_t   sumbno;         /* summary block number */
1102
1103         bp = NULL;
1104         for (log = omp->m_rsumlevels - 1; log >= 0; log--) {
1105                 for (bbno = omp->m_sb.sb_rbmblocks - 1;
1106                      (xfs_srtblock_t)bbno >= 0;
1107                      bbno--) {
1108                         error = xfs_rtget_summary(omp, tp, log, bbno, &bp,
1109                                 &sumbno, &sum);
1110                         if (error)
1111                                 return error;
1112                         if (sum == 0)
1113                                 continue;
1114                         error = xfs_rtmodify_summary(omp, tp, log, bbno, -sum,
1115                                 &bp, &sumbno);
1116                         if (error)
1117                                 return error;
1118                         error = xfs_rtmodify_summary(nmp, tp, log, bbno, sum,
1119                                 &bp, &sumbno);
1120                         if (error)
1121                                 return error;
1122                         ASSERT(sum > 0);
1123                 }
1124         }
1125         return 0;
1126 }
1127
1128 /*
1129  * Searching backward from start to limit, find the first block whose
1130  * allocated/free state is different from start's.
1131  */
1132 STATIC int                              /* error */
1133 xfs_rtfind_back(
1134         xfs_mount_t     *mp,            /* file system mount point */
1135         xfs_trans_t     *tp,            /* transaction pointer */
1136         xfs_rtblock_t   start,          /* starting block to look at */
1137         xfs_rtblock_t   limit,          /* last block to look at */
1138         xfs_rtblock_t   *rtblock)       /* out: start block found */
1139 {
1140         xfs_rtword_t    *b;             /* current word in buffer */
1141         int             bit;            /* bit number in the word */
1142         xfs_rtblock_t   block;          /* bitmap block number */
1143         xfs_buf_t       *bp;            /* buf for the block */
1144         xfs_rtword_t    *bufp;          /* starting word in buffer */
1145         int             error;          /* error value */
1146         xfs_rtblock_t   firstbit;       /* first useful bit in the word */
1147         xfs_rtblock_t   i;              /* current bit number rel. to start */
1148         xfs_rtblock_t   len;            /* length of inspected area */
1149         xfs_rtword_t    mask;           /* mask of relevant bits for value */
1150         xfs_rtword_t    want;           /* mask for "good" values */
1151         xfs_rtword_t    wdiff;          /* difference from wanted value */
1152         int             word;           /* word number in the buffer */
1153
1154         /*
1155          * Compute and read in starting bitmap block for starting block.
1156          */
1157         block = XFS_BITTOBLOCK(mp, start);
1158         error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
1159         if (error) {
1160                 return error;
1161         }
1162         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1163         /*
1164          * Get the first word's index & point to it.
1165          */
1166         word = XFS_BITTOWORD(mp, start);
1167         b = &bufp[word];
1168         bit = (int)(start & (XFS_NBWORD - 1));
1169         len = start - limit + 1;
1170         /*
1171          * Compute match value, based on the bit at start: if 1 (free)
1172          * then all-ones, else all-zeroes.
1173          */
1174         want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
1175         /*
1176          * If the starting position is not word-aligned, deal with the
1177          * partial word.
1178          */
1179         if (bit < XFS_NBWORD - 1) {
1180                 /*
1181                  * Calculate first (leftmost) bit number to look at,
1182                  * and mask for all the relevant bits in this word.
1183                  */
1184                 firstbit = XFS_RTMAX((xfs_srtblock_t)(bit - len + 1), 0);
1185                 mask = (((xfs_rtword_t)1 << (bit - firstbit + 1)) - 1) <<
1186                         firstbit;
1187                 /*
1188                  * Calculate the difference between the value there
1189                  * and what we're looking for.
1190                  */
1191                 if ((wdiff = (*b ^ want) & mask)) {
1192                         /*
1193                          * Different.  Mark where we are and return.
1194                          */
1195                         xfs_trans_brelse(tp, bp);
1196                         i = bit - XFS_RTHIBIT(wdiff);
1197                         *rtblock = start - i + 1;
1198                         return 0;
1199                 }
1200                 i = bit - firstbit + 1;
1201                 /*
1202                  * Go on to previous block if that's where the previous word is
1203                  * and we need the previous word.
1204                  */
1205                 if (--word == -1 && i < len) {
1206                         /*
1207                          * If done with this block, get the previous one.
1208                          */
1209                         xfs_trans_brelse(tp, bp);
1210                         error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
1211                         if (error) {
1212                                 return error;
1213                         }
1214                         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1215                         word = XFS_BLOCKWMASK(mp);
1216                         b = &bufp[word];
1217                 } else {
1218                         /*
1219                          * Go on to the previous word in the buffer.
1220                          */
1221                         b--;
1222                 }
1223         } else {
1224                 /*
1225                  * Starting on a word boundary, no partial word.
1226                  */
1227                 i = 0;
1228         }
1229         /*
1230          * Loop over whole words in buffers.  When we use up one buffer
1231          * we move on to the previous one.
1232          */
1233         while (len - i >= XFS_NBWORD) {
1234                 /*
1235                  * Compute difference between actual and desired value.
1236                  */
1237                 if ((wdiff = *b ^ want)) {
1238                         /*
1239                          * Different, mark where we are and return.
1240                          */
1241                         xfs_trans_brelse(tp, bp);
1242                         i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
1243                         *rtblock = start - i + 1;
1244                         return 0;
1245                 }
1246                 i += XFS_NBWORD;
1247                 /*
1248                  * Go on to previous block if that's where the previous word is
1249                  * and we need the previous word.
1250                  */
1251                 if (--word == -1 && i < len) {
1252                         /*
1253                          * If done with this block, get the previous one.
1254                          */
1255                         xfs_trans_brelse(tp, bp);
1256                         error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
1257                         if (error) {
1258                                 return error;
1259                         }
1260                         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1261                         word = XFS_BLOCKWMASK(mp);
1262                         b = &bufp[word];
1263                 } else {
1264                         /*
1265                          * Go on to the previous word in the buffer.
1266                          */
1267                         b--;
1268                 }
1269         }
1270         /*
1271          * If not ending on a word boundary, deal with the last
1272          * (partial) word.
1273          */
1274         if (len - i) {
1275                 /*
1276                  * Calculate first (leftmost) bit number to look at,
1277                  * and mask for all the relevant bits in this word.
1278                  */
1279                 firstbit = XFS_NBWORD - (len - i);
1280                 mask = (((xfs_rtword_t)1 << (len - i)) - 1) << firstbit;
1281                 /*
1282                  * Compute difference between actual and desired value.
1283                  */
1284                 if ((wdiff = (*b ^ want) & mask)) {
1285                         /*
1286                          * Different, mark where we are and return.
1287                          */
1288                         xfs_trans_brelse(tp, bp);
1289                         i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
1290                         *rtblock = start - i + 1;
1291                         return 0;
1292                 } else
1293                         i = len;
1294         }
1295         /*
1296          * No match, return that we scanned the whole area.
1297          */
1298         xfs_trans_brelse(tp, bp);
1299         *rtblock = start - i + 1;
1300         return 0;
1301 }
1302
1303 /*
1304  * Searching forward from start to limit, find the first block whose
1305  * allocated/free state is different from start's.
1306  */
1307 STATIC int                              /* error */
1308 xfs_rtfind_forw(
1309         xfs_mount_t     *mp,            /* file system mount point */
1310         xfs_trans_t     *tp,            /* transaction pointer */
1311         xfs_rtblock_t   start,          /* starting block to look at */
1312         xfs_rtblock_t   limit,          /* last block to look at */
1313         xfs_rtblock_t   *rtblock)       /* out: start block found */
1314 {
1315         xfs_rtword_t    *b;             /* current word in buffer */
1316         int             bit;            /* bit number in the word */
1317         xfs_rtblock_t   block;          /* bitmap block number */
1318         xfs_buf_t       *bp;            /* buf for the block */
1319         xfs_rtword_t    *bufp;          /* starting word in buffer */
1320         int             error;          /* error value */
1321         xfs_rtblock_t   i;              /* current bit number rel. to start */
1322         xfs_rtblock_t   lastbit;        /* last useful bit in the word */
1323         xfs_rtblock_t   len;            /* length of inspected area */
1324         xfs_rtword_t    mask;           /* mask of relevant bits for value */
1325         xfs_rtword_t    want;           /* mask for "good" values */
1326         xfs_rtword_t    wdiff;          /* difference from wanted value */
1327         int             word;           /* word number in the buffer */
1328
1329         /*
1330          * Compute and read in starting bitmap block for starting block.
1331          */
1332         block = XFS_BITTOBLOCK(mp, start);
1333         error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
1334         if (error) {
1335                 return error;
1336         }
1337         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1338         /*
1339          * Get the first word's index & point to it.
1340          */
1341         word = XFS_BITTOWORD(mp, start);
1342         b = &bufp[word];
1343         bit = (int)(start & (XFS_NBWORD - 1));
1344         len = limit - start + 1;
1345         /*
1346          * Compute match value, based on the bit at start: if 1 (free)
1347          * then all-ones, else all-zeroes.
1348          */
1349         want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
1350         /*
1351          * If the starting position is not word-aligned, deal with the
1352          * partial word.
1353          */
1354         if (bit) {
1355                 /*
1356                  * Calculate last (rightmost) bit number to look at,
1357                  * and mask for all the relevant bits in this word.
1358                  */
1359                 lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
1360                 mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
1361                 /*
1362                  * Calculate the difference between the value there
1363                  * and what we're looking for.
1364                  */
1365                 if ((wdiff = (*b ^ want) & mask)) {
1366                         /*
1367                          * Different.  Mark where we are and return.
1368                          */
1369                         xfs_trans_brelse(tp, bp);
1370                         i = XFS_RTLOBIT(wdiff) - bit;
1371                         *rtblock = start + i - 1;
1372                         return 0;
1373                 }
1374                 i = lastbit - bit;
1375                 /*
1376                  * Go on to next block if that's where the next word is
1377                  * and we need the next word.
1378                  */
1379                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1380                         /*
1381                          * If done with this block, get the previous one.
1382                          */
1383                         xfs_trans_brelse(tp, bp);
1384                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1385                         if (error) {
1386                                 return error;
1387                         }
1388                         b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1389                         word = 0;
1390                 } else {
1391                         /*
1392                          * Go on to the previous word in the buffer.
1393                          */
1394                         b++;
1395                 }
1396         } else {
1397                 /*
1398                  * Starting on a word boundary, no partial word.
1399                  */
1400                 i = 0;
1401         }
1402         /*
1403          * Loop over whole words in buffers.  When we use up one buffer
1404          * we move on to the next one.
1405          */
1406         while (len - i >= XFS_NBWORD) {
1407                 /*
1408                  * Compute difference between actual and desired value.
1409                  */
1410                 if ((wdiff = *b ^ want)) {
1411                         /*
1412                          * Different, mark where we are and return.
1413                          */
1414                         xfs_trans_brelse(tp, bp);
1415                         i += XFS_RTLOBIT(wdiff);
1416                         *rtblock = start + i - 1;
1417                         return 0;
1418                 }
1419                 i += XFS_NBWORD;
1420                 /*
1421                  * Go on to next block if that's where the next word is
1422                  * and we need the next word.
1423                  */
1424                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1425                         /*
1426                          * If done with this block, get the next one.
1427                          */
1428                         xfs_trans_brelse(tp, bp);
1429                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1430                         if (error) {
1431                                 return error;
1432                         }
1433                         b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1434                         word = 0;
1435                 } else {
1436                         /*
1437                          * Go on to the next word in the buffer.
1438                          */
1439                         b++;
1440                 }
1441         }
1442         /*
1443          * If not ending on a word boundary, deal with the last
1444          * (partial) word.
1445          */
1446         if ((lastbit = len - i)) {
1447                 /*
1448                  * Calculate mask for all the relevant bits in this word.
1449                  */
1450                 mask = ((xfs_rtword_t)1 << lastbit) - 1;
1451                 /*
1452                  * Compute difference between actual and desired value.
1453                  */
1454                 if ((wdiff = (*b ^ want) & mask)) {
1455                         /*
1456                          * Different, mark where we are and return.
1457                          */
1458                         xfs_trans_brelse(tp, bp);
1459                         i += XFS_RTLOBIT(wdiff);
1460                         *rtblock = start + i - 1;
1461                         return 0;
1462                 } else
1463                         i = len;
1464         }
1465         /*
1466          * No match, return that we scanned the whole area.
1467          */
1468         xfs_trans_brelse(tp, bp);
1469         *rtblock = start + i - 1;
1470         return 0;
1471 }
1472
1473 /*
1474  * Mark an extent specified by start and len freed.
1475  * Updates all the summary information as well as the bitmap.
1476  */
1477 STATIC int                              /* error */
1478 xfs_rtfree_range(
1479         xfs_mount_t     *mp,            /* file system mount point */
1480         xfs_trans_t     *tp,            /* transaction pointer */
1481         xfs_rtblock_t   start,          /* starting block to free */
1482         xfs_extlen_t    len,            /* length to free */
1483         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
1484         xfs_fsblock_t   *rsb)           /* in/out: summary block number */
1485 {
1486         xfs_rtblock_t   end;            /* end of the freed extent */
1487         int             error;          /* error value */
1488         xfs_rtblock_t   postblock;      /* first block freed > end */
1489         xfs_rtblock_t   preblock;       /* first block freed < start */
1490
1491         end = start + len - 1;
1492         /*
1493          * Modify the bitmap to mark this extent freed.
1494          */
1495         error = xfs_rtmodify_range(mp, tp, start, len, 1);
1496         if (error) {
1497                 return error;
1498         }
1499         /*
1500          * Assume we're freeing out of the middle of an allocated extent.
1501          * We need to find the beginning and end of the extent so we can
1502          * properly update the summary.
1503          */
1504         error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
1505         if (error) {
1506                 return error;
1507         }
1508         /*
1509          * Find the next allocated block (end of allocated extent).
1510          */
1511         error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
1512                 &postblock);
1513         if (error)
1514                 return error;
1515         /*
1516          * If there are blocks not being freed at the front of the
1517          * old extent, add summary data for them to be allocated.
1518          */
1519         if (preblock < start) {
1520                 error = xfs_rtmodify_summary(mp, tp,
1521                         XFS_RTBLOCKLOG(start - preblock),
1522                         XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
1523                 if (error) {
1524                         return error;
1525                 }
1526         }
1527         /*
1528          * If there are blocks not being freed at the end of the
1529          * old extent, add summary data for them to be allocated.
1530          */
1531         if (postblock > end) {
1532                 error = xfs_rtmodify_summary(mp, tp,
1533                         XFS_RTBLOCKLOG(postblock - end),
1534                         XFS_BITTOBLOCK(mp, end + 1), -1, rbpp, rsb);
1535                 if (error) {
1536                         return error;
1537                 }
1538         }
1539         /*
1540          * Increment the summary information corresponding to the entire
1541          * (new) free extent.
1542          */
1543         error = xfs_rtmodify_summary(mp, tp,
1544                 XFS_RTBLOCKLOG(postblock + 1 - preblock),
1545                 XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
1546         return error;
1547 }
1548
1549 /*
1550  * Read and return the summary information for a given extent size,
1551  * bitmap block combination.
1552  * Keeps track of a current summary block, so we don't keep reading
1553  * it from the buffer cache.
1554  */
1555 STATIC int                              /* error */
1556 xfs_rtget_summary(
1557         xfs_mount_t     *mp,            /* file system mount structure */
1558         xfs_trans_t     *tp,            /* transaction pointer */
1559         int             log,            /* log2 of extent size */
1560         xfs_rtblock_t   bbno,           /* bitmap block number */
1561         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
1562         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
1563         xfs_suminfo_t   *sum)           /* out: summary info for this block */
1564 {
1565         xfs_buf_t       *bp;            /* buffer for summary block */
1566         int             error;          /* error value */
1567         xfs_fsblock_t   sb;             /* summary fsblock */
1568         int             so;             /* index into the summary file */
1569         xfs_suminfo_t   *sp;            /* pointer to returned data */
1570
1571         /*
1572          * Compute entry number in the summary file.
1573          */
1574         so = XFS_SUMOFFS(mp, log, bbno);
1575         /*
1576          * Compute the block number in the summary file.
1577          */
1578         sb = XFS_SUMOFFSTOBLOCK(mp, so);
1579         /*
1580          * If we have an old buffer, and the block number matches, use that.
1581          */
1582         if (rbpp && *rbpp && *rsb == sb)
1583                 bp = *rbpp;
1584         /*
1585          * Otherwise we have to get the buffer.
1586          */
1587         else {
1588                 /*
1589                  * If there was an old one, get rid of it first.
1590                  */
1591                 if (rbpp && *rbpp)
1592                         xfs_trans_brelse(tp, *rbpp);
1593                 error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
1594                 if (error) {
1595                         return error;
1596                 }
1597                 /*
1598                  * Remember this buffer and block for the next call.
1599                  */
1600                 if (rbpp) {
1601                         *rbpp = bp;
1602                         *rsb = sb;
1603                 }
1604         }
1605         /*
1606          * Point to the summary information & copy it out.
1607          */
1608         sp = XFS_SUMPTR(mp, bp, so);
1609         *sum = *sp;
1610         /*
1611          * Drop the buffer if we're not asked to remember it.
1612          */
1613         if (!rbpp)
1614                 xfs_trans_brelse(tp, bp);
1615         return 0;
1616 }
1617
1618 /*
1619  * Set the given range of bitmap bits to the given value.
1620  * Do whatever I/O and logging is required.
1621  */
1622 STATIC int                              /* error */
1623 xfs_rtmodify_range(
1624         xfs_mount_t     *mp,            /* file system mount point */
1625         xfs_trans_t     *tp,            /* transaction pointer */
1626         xfs_rtblock_t   start,          /* starting block to modify */
1627         xfs_extlen_t    len,            /* length of extent to modify */
1628         int             val)            /* 1 for free, 0 for allocated */
1629 {
1630         xfs_rtword_t    *b;             /* current word in buffer */
1631         int             bit;            /* bit number in the word */
1632         xfs_rtblock_t   block;          /* bitmap block number */
1633         xfs_buf_t       *bp;            /* buf for the block */
1634         xfs_rtword_t    *bufp;          /* starting word in buffer */
1635         int             error;          /* error value */
1636         xfs_rtword_t    *first;         /* first used word in the buffer */
1637         int             i;              /* current bit number rel. to start */
1638         int             lastbit;        /* last useful bit in word */
1639         xfs_rtword_t    mask;           /* mask o frelevant bits for value */
1640         int             word;           /* word number in the buffer */
1641
1642         /*
1643          * Compute starting bitmap block number.
1644          */
1645         block = XFS_BITTOBLOCK(mp, start);
1646         /*
1647          * Read the bitmap block, and point to its data.
1648          */
1649         error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
1650         if (error) {
1651                 return error;
1652         }
1653         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1654         /*
1655          * Compute the starting word's address, and starting bit.
1656          */
1657         word = XFS_BITTOWORD(mp, start);
1658         first = b = &bufp[word];
1659         bit = (int)(start & (XFS_NBWORD - 1));
1660         /*
1661          * 0 (allocated) => all zeroes; 1 (free) => all ones.
1662          */
1663         val = -val;
1664         /*
1665          * If not starting on a word boundary, deal with the first
1666          * (partial) word.
1667          */
1668         if (bit) {
1669                 /*
1670                  * Compute first bit not changed and mask of relevant bits.
1671                  */
1672                 lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
1673                 mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
1674                 /*
1675                  * Set/clear the active bits.
1676                  */
1677                 if (val)
1678                         *b |= mask;
1679                 else
1680                         *b &= ~mask;
1681                 i = lastbit - bit;
1682                 /*
1683                  * Go on to the next block if that's where the next word is
1684                  * and we need the next word.
1685                  */
1686                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1687                         /*
1688                          * Log the changed part of this block.
1689                          * Get the next one.
1690                          */
1691                         xfs_trans_log_buf(tp, bp,
1692                                 (uint)((char *)first - (char *)bufp),
1693                                 (uint)((char *)b - (char *)bufp));
1694                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1695                         if (error) {
1696                                 return error;
1697                         }
1698                         first = b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1699                         word = 0;
1700                 } else {
1701                         /*
1702                          * Go on to the next word in the buffer
1703                          */
1704                         b++;
1705                 }
1706         } else {
1707                 /*
1708                  * Starting on a word boundary, no partial word.
1709                  */
1710                 i = 0;
1711         }
1712         /*
1713          * Loop over whole words in buffers.  When we use up one buffer
1714          * we move on to the next one.
1715          */
1716         while (len - i >= XFS_NBWORD) {
1717                 /*
1718                  * Set the word value correctly.
1719                  */
1720                 *b = val;
1721                 i += XFS_NBWORD;
1722                 /*
1723                  * Go on to the next block if that's where the next word is
1724                  * and we need the next word.
1725                  */
1726                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1727                         /*
1728                          * Log the changed part of this block.
1729                          * Get the next one.
1730                          */
1731                         xfs_trans_log_buf(tp, bp,
1732                                 (uint)((char *)first - (char *)bufp),
1733                                 (uint)((char *)b - (char *)bufp));
1734                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1735                         if (error) {
1736                                 return error;
1737                         }
1738                         first = b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1739                         word = 0;
1740                 } else {
1741                         /*
1742                          * Go on to the next word in the buffer
1743                          */
1744                         b++;
1745                 }
1746         }
1747         /*
1748          * If not ending on a word boundary, deal with the last
1749          * (partial) word.
1750          */
1751         if ((lastbit = len - i)) {
1752                 /*
1753                  * Compute a mask of relevant bits.
1754                  */
1755                 bit = 0;
1756                 mask = ((xfs_rtword_t)1 << lastbit) - 1;
1757                 /*
1758                  * Set/clear the active bits.
1759                  */
1760                 if (val)
1761                         *b |= mask;
1762                 else
1763                         *b &= ~mask;
1764                 b++;
1765         }
1766         /*
1767          * Log any remaining changed bytes.
1768          */
1769         if (b > first)
1770                 xfs_trans_log_buf(tp, bp, (uint)((char *)first - (char *)bufp),
1771                         (uint)((char *)b - (char *)bufp - 1));
1772         return 0;
1773 }
1774
1775 /*
1776  * Read and modify the summary information for a given extent size,
1777  * bitmap block combination.
1778  * Keeps track of a current summary block, so we don't keep reading
1779  * it from the buffer cache.
1780  */
1781 STATIC int                              /* error */
1782 xfs_rtmodify_summary(
1783         xfs_mount_t     *mp,            /* file system mount point */
1784         xfs_trans_t     *tp,            /* transaction pointer */
1785         int             log,            /* log2 of extent size */
1786         xfs_rtblock_t   bbno,           /* bitmap block number */
1787         int             delta,          /* change to make to summary info */
1788         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
1789         xfs_fsblock_t   *rsb)           /* in/out: summary block number */
1790 {
1791         xfs_buf_t       *bp;            /* buffer for the summary block */
1792         int             error;          /* error value */
1793         xfs_fsblock_t   sb;             /* summary fsblock */
1794         int             so;             /* index into the summary file */
1795         xfs_suminfo_t   *sp;            /* pointer to returned data */
1796
1797         /*
1798          * Compute entry number in the summary file.
1799          */
1800         so = XFS_SUMOFFS(mp, log, bbno);
1801         /*
1802          * Compute the block number in the summary file.
1803          */
1804         sb = XFS_SUMOFFSTOBLOCK(mp, so);
1805         /*
1806          * If we have an old buffer, and the block number matches, use that.
1807          */
1808         if (rbpp && *rbpp && *rsb == sb)
1809                 bp = *rbpp;
1810         /*
1811          * Otherwise we have to get the buffer.
1812          */
1813         else {
1814                 /*
1815                  * If there was an old one, get rid of it first.
1816                  */
1817                 if (rbpp && *rbpp)
1818                         xfs_trans_brelse(tp, *rbpp);
1819                 error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
1820                 if (error) {
1821                         return error;
1822                 }
1823                 /*
1824                  * Remember this buffer and block for the next call.
1825                  */
1826                 if (rbpp) {
1827                         *rbpp = bp;
1828                         *rsb = sb;
1829                 }
1830         }
1831         /*
1832          * Point to the summary information, modify and log it.
1833          */
1834         sp = XFS_SUMPTR(mp, bp, so);
1835         *sp += delta;
1836         xfs_trans_log_buf(tp, bp, (uint)((char *)sp - (char *)XFS_BUF_PTR(bp)),
1837                 (uint)((char *)sp - (char *)XFS_BUF_PTR(bp) + sizeof(*sp) - 1));
1838         return 0;
1839 }
1840
1841 /*
1842  * Visible (exported) functions.
1843  */
1844
1845 /*
1846  * Grow the realtime area of the filesystem.
1847  */
1848 int
1849 xfs_growfs_rt(
1850         xfs_mount_t     *mp,            /* mount point for filesystem */
1851         xfs_growfs_rt_t *in)            /* growfs rt input struct */
1852 {
1853         xfs_rtblock_t   bmbno;          /* bitmap block number */
1854         xfs_buf_t       *bp;            /* temporary buffer */
1855         int             error;          /* error return value */
1856         xfs_inode_t     *ip;            /* bitmap inode, used as lock */
1857         xfs_mount_t     *nmp;           /* new (fake) mount structure */
1858         xfs_drfsbno_t   nrblocks;       /* new number of realtime blocks */
1859         xfs_extlen_t    nrbmblocks;     /* new number of rt bitmap blocks */
1860         xfs_drtbno_t    nrextents;      /* new number of realtime extents */
1861         uint8_t         nrextslog;      /* new log2 of sb_rextents */
1862         xfs_extlen_t    nrsumblocks;    /* new number of summary blocks */
1863         uint            nrsumlevels;    /* new rt summary levels */
1864         uint            nrsumsize;      /* new size of rt summary, bytes */
1865         xfs_sb_t        *nsbp;          /* new superblock */
1866         xfs_extlen_t    rbmblocks;      /* current number of rt bitmap blocks */
1867         xfs_extlen_t    rsumblocks;     /* current number of rt summary blks */
1868         xfs_sb_t        *sbp;           /* old superblock */
1869         xfs_fsblock_t   sumbno;         /* summary block number */
1870
1871         sbp = &mp->m_sb;
1872         /*
1873          * Initial error checking.
1874          */
1875         if (!capable(CAP_SYS_ADMIN))
1876                 return XFS_ERROR(EPERM);
1877         if (mp->m_rtdev_targp == NULL || mp->m_rbmip == NULL ||
1878             (nrblocks = in->newblocks) <= sbp->sb_rblocks ||
1879             (sbp->sb_rblocks && (in->extsize != sbp->sb_rextsize)))
1880                 return XFS_ERROR(EINVAL);
1881         if ((error = xfs_sb_validate_fsb_count(sbp, nrblocks)))
1882                 return error;
1883         /*
1884          * Read in the last block of the device, make sure it exists.
1885          */
1886         error = xfs_read_buf(mp, mp->m_rtdev_targp,
1887                         XFS_FSB_TO_BB(mp, nrblocks - 1),
1888                         XFS_FSB_TO_BB(mp, 1), 0, &bp);
1889         if (error)
1890                 return error;
1891         ASSERT(bp);
1892         xfs_buf_relse(bp);
1893         /*
1894          * Calculate new parameters.  These are the final values to be reached.
1895          */
1896         nrextents = nrblocks;
1897         do_div(nrextents, in->extsize);
1898         nrbmblocks = howmany_64(nrextents, NBBY * sbp->sb_blocksize);
1899         nrextslog = xfs_highbit32(nrextents);
1900         nrsumlevels = nrextslog + 1;
1901         nrsumsize = (uint)sizeof(xfs_suminfo_t) * nrsumlevels * nrbmblocks;
1902         nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
1903         nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
1904         /*
1905          * New summary size can't be more than half the size of
1906          * the log.  This prevents us from getting a log overflow,
1907          * since we'll log basically the whole summary file at once.
1908          */
1909         if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1))
1910                 return XFS_ERROR(EINVAL);
1911         /*
1912          * Get the old block counts for bitmap and summary inodes.
1913          * These can't change since other growfs callers are locked out.
1914          */
1915         rbmblocks = XFS_B_TO_FSB(mp, mp->m_rbmip->i_d.di_size);
1916         rsumblocks = XFS_B_TO_FSB(mp, mp->m_rsumip->i_d.di_size);
1917         /*
1918          * Allocate space to the bitmap and summary files, as necessary.
1919          */
1920         if ((error = xfs_growfs_rt_alloc(mp, rbmblocks, nrbmblocks,
1921                         mp->m_sb.sb_rbmino)))
1922                 return error;
1923         if ((error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks,
1924                         mp->m_sb.sb_rsumino)))
1925                 return error;
1926         /*
1927          * Allocate a new (fake) mount/sb.
1928          */
1929         nmp = kmem_alloc(sizeof(*nmp), KM_SLEEP);
1930         /*
1931          * Loop over the bitmap blocks.
1932          * We will do everything one bitmap block at a time.
1933          * Skip the current block if it is exactly full.
1934          * This also deals with the case where there were no rtextents before.
1935          */
1936         for (bmbno = sbp->sb_rbmblocks -
1937                      ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
1938              bmbno < nrbmblocks;
1939              bmbno++) {
1940                 xfs_trans_t     *tp;
1941                 int             cancelflags = 0;
1942
1943                 *nmp = *mp;
1944                 nsbp = &nmp->m_sb;
1945                 /*
1946                  * Calculate new sb and mount fields for this round.
1947                  */
1948                 nsbp->sb_rextsize = in->extsize;
1949                 nsbp->sb_rbmblocks = bmbno + 1;
1950                 nsbp->sb_rblocks =
1951                         XFS_RTMIN(nrblocks,
1952                                   nsbp->sb_rbmblocks * NBBY *
1953                                   nsbp->sb_blocksize * nsbp->sb_rextsize);
1954                 nsbp->sb_rextents = nsbp->sb_rblocks;
1955                 do_div(nsbp->sb_rextents, nsbp->sb_rextsize);
1956                 ASSERT(nsbp->sb_rextents != 0);
1957                 nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents);
1958                 nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
1959                 nrsumsize =
1960                         (uint)sizeof(xfs_suminfo_t) * nrsumlevels *
1961                         nsbp->sb_rbmblocks;
1962                 nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
1963                 nmp->m_rsumsize = nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
1964                 /*
1965                  * Start a transaction, get the log reservation.
1966                  */
1967                 tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_FREE);
1968                 if ((error = xfs_trans_reserve(tp, 0,
1969                                 XFS_GROWRTFREE_LOG_RES(nmp), 0, 0, 0)))
1970                         goto error_cancel;
1971                 /*
1972                  * Lock out other callers by grabbing the bitmap inode lock.
1973                  */
1974                 if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
1975                                                 XFS_ILOCK_EXCL, &ip)))
1976                         goto error_cancel;
1977                 ASSERT(ip == mp->m_rbmip);
1978                 /*
1979                  * Update the bitmap inode's size.
1980                  */
1981                 mp->m_rbmip->i_d.di_size =
1982                         nsbp->sb_rbmblocks * nsbp->sb_blocksize;
1983                 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1984                 cancelflags |= XFS_TRANS_ABORT;
1985                 /*
1986                  * Get the summary inode into the transaction.
1987                  */
1988                 if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rsumino, 0,
1989                                                 XFS_ILOCK_EXCL, &ip)))
1990                         goto error_cancel;
1991                 ASSERT(ip == mp->m_rsumip);
1992                 /*
1993                  * Update the summary inode's size.
1994                  */
1995                 mp->m_rsumip->i_d.di_size = nmp->m_rsumsize;
1996                 xfs_trans_log_inode(tp, mp->m_rsumip, XFS_ILOG_CORE);
1997                 /*
1998                  * Copy summary data from old to new sizes.
1999                  * Do this when the real size (not block-aligned) changes.
2000                  */
2001                 if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
2002                     mp->m_rsumlevels != nmp->m_rsumlevels) {
2003                         error = xfs_rtcopy_summary(mp, nmp, tp);
2004                         if (error)
2005                                 goto error_cancel;
2006                 }
2007                 /*
2008                  * Update superblock fields.
2009                  */
2010                 if (nsbp->sb_rextsize != sbp->sb_rextsize)
2011                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
2012                                 nsbp->sb_rextsize - sbp->sb_rextsize);
2013                 if (nsbp->sb_rbmblocks != sbp->sb_rbmblocks)
2014                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
2015                                 nsbp->sb_rbmblocks - sbp->sb_rbmblocks);
2016                 if (nsbp->sb_rblocks != sbp->sb_rblocks)
2017                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
2018                                 nsbp->sb_rblocks - sbp->sb_rblocks);
2019                 if (nsbp->sb_rextents != sbp->sb_rextents)
2020                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
2021                                 nsbp->sb_rextents - sbp->sb_rextents);
2022                 if (nsbp->sb_rextslog != sbp->sb_rextslog)
2023                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
2024                                 nsbp->sb_rextslog - sbp->sb_rextslog);
2025                 /*
2026                  * Free new extent.
2027                  */
2028                 bp = NULL;
2029                 error = xfs_rtfree_range(nmp, tp, sbp->sb_rextents,
2030                         nsbp->sb_rextents - sbp->sb_rextents, &bp, &sumbno);
2031                 if (error) {
2032 error_cancel:
2033                         xfs_trans_cancel(tp, cancelflags);
2034                         break;
2035                 }
2036                 /*
2037                  * Mark more blocks free in the superblock.
2038                  */
2039                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS,
2040                         nsbp->sb_rextents - sbp->sb_rextents);
2041                 /*
2042                  * Update mp values into the real mp structure.
2043                  */
2044                 mp->m_rsumlevels = nrsumlevels;
2045                 mp->m_rsumsize = nrsumsize;
2046
2047                 error = xfs_trans_commit(tp, 0);
2048                 if (error)
2049                         break;
2050         }
2051
2052         /*
2053          * Free the fake mp structure.
2054          */
2055         kmem_free(nmp);
2056
2057         return error;
2058 }
2059
2060 /*
2061  * Allocate an extent in the realtime subvolume, with the usual allocation
2062  * parameters.  The length units are all in realtime extents, as is the
2063  * result block number.
2064  */
2065 int                                     /* error */
2066 xfs_rtallocate_extent(
2067         xfs_trans_t     *tp,            /* transaction pointer */
2068         xfs_rtblock_t   bno,            /* starting block number to allocate */
2069         xfs_extlen_t    minlen,         /* minimum length to allocate */
2070         xfs_extlen_t    maxlen,         /* maximum length to allocate */
2071         xfs_extlen_t    *len,           /* out: actual length allocated */
2072         xfs_alloctype_t type,           /* allocation type XFS_ALLOCTYPE... */
2073         int             wasdel,         /* was a delayed allocation extent */
2074         xfs_extlen_t    prod,           /* extent product factor */
2075         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
2076 {
2077         int             error;          /* error value */
2078         xfs_inode_t     *ip;            /* inode for bitmap file */
2079         xfs_mount_t     *mp;            /* file system mount structure */
2080         xfs_rtblock_t   r;              /* result allocated block */
2081         xfs_fsblock_t   sb;             /* summary file block number */
2082         xfs_buf_t       *sumbp;         /* summary file block buffer */
2083
2084         ASSERT(minlen > 0 && minlen <= maxlen);
2085         mp = tp->t_mountp;
2086         /*
2087          * If prod is set then figure out what to do to minlen and maxlen.
2088          */
2089         if (prod > 1) {
2090                 xfs_extlen_t    i;
2091
2092                 if ((i = maxlen % prod))
2093                         maxlen -= i;
2094                 if ((i = minlen % prod))
2095                         minlen += prod - i;
2096                 if (maxlen < minlen) {
2097                         *rtblock = NULLRTBLOCK;
2098                         return 0;
2099                 }
2100         }
2101         /*
2102          * Lock out other callers by grabbing the bitmap inode lock.
2103          */
2104         if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
2105                                         XFS_ILOCK_EXCL, &ip)))
2106                 return error;
2107         sumbp = NULL;
2108         /*
2109          * Allocate by size, or near another block, or exactly at some block.
2110          */
2111         switch (type) {
2112         case XFS_ALLOCTYPE_ANY_AG:
2113                 error = xfs_rtallocate_extent_size(mp, tp, minlen, maxlen, len,
2114                                 &sumbp, &sb, prod, &r);
2115                 break;
2116         case XFS_ALLOCTYPE_NEAR_BNO:
2117                 error = xfs_rtallocate_extent_near(mp, tp, bno, minlen, maxlen,
2118                                 len, &sumbp, &sb, prod, &r);
2119                 break;
2120         case XFS_ALLOCTYPE_THIS_BNO:
2121                 error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen,
2122                                 len, &sumbp, &sb, prod, &r);
2123                 break;
2124         default:
2125                 ASSERT(0);
2126         }
2127         if (error) {
2128                 return error;
2129         }
2130         /*
2131          * If it worked, update the superblock.
2132          */
2133         if (r != NULLRTBLOCK) {
2134                 long    slen = (long)*len;
2135
2136                 ASSERT(*len >= minlen && *len <= maxlen);
2137                 if (wasdel)
2138                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FREXTENTS, -slen);
2139                 else
2140                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, -slen);
2141         }
2142         *rtblock = r;
2143         return 0;
2144 }
2145
2146 /*
2147  * Free an extent in the realtime subvolume.  Length is expressed in
2148  * realtime extents, as is the block number.
2149  */
2150 int                                     /* error */
2151 xfs_rtfree_extent(
2152         xfs_trans_t     *tp,            /* transaction pointer */
2153         xfs_rtblock_t   bno,            /* starting block number to free */
2154         xfs_extlen_t    len)            /* length of extent freed */
2155 {
2156         int             error;          /* error value */
2157         xfs_inode_t     *ip;            /* bitmap file inode */
2158         xfs_mount_t     *mp;            /* file system mount structure */
2159         xfs_fsblock_t   sb;             /* summary file block number */
2160         xfs_buf_t       *sumbp;         /* summary file block buffer */
2161
2162         mp = tp->t_mountp;
2163         /*
2164          * Synchronize by locking the bitmap inode.
2165          */
2166         if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
2167                                         XFS_ILOCK_EXCL, &ip)))
2168                 return error;
2169 #if defined(__KERNEL__) && defined(DEBUG)
2170         /*
2171          * Check to see that this whole range is currently allocated.
2172          */
2173         {
2174                 int     stat;           /* result from checking range */
2175
2176                 error = xfs_rtcheck_alloc_range(mp, tp, bno, len, &stat);
2177                 if (error) {
2178                         return error;
2179                 }
2180                 ASSERT(stat);
2181         }
2182 #endif
2183         sumbp = NULL;
2184         /*
2185          * Free the range of realtime blocks.
2186          */
2187         error = xfs_rtfree_range(mp, tp, bno, len, &sumbp, &sb);
2188         if (error) {
2189                 return error;
2190         }
2191         /*
2192          * Mark more blocks free in the superblock.
2193          */
2194         xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, (long)len);
2195         /*
2196          * If we've now freed all the blocks, reset the file sequence
2197          * number to 0.
2198          */
2199         if (tp->t_frextents_delta + mp->m_sb.sb_frextents ==
2200             mp->m_sb.sb_rextents) {
2201                 if (!(ip->i_d.di_flags & XFS_DIFLAG_NEWRTBM))
2202                         ip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
2203                 *(__uint64_t *)&ip->i_d.di_atime = 0;
2204                 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2205         }
2206         return 0;
2207 }
2208
2209 /*
2210  * Initialize realtime fields in the mount structure.
2211  */
2212 int                             /* error */
2213 xfs_rtmount_init(
2214         xfs_mount_t     *mp)    /* file system mount structure */
2215 {
2216         xfs_buf_t       *bp;    /* buffer for last block of subvolume */
2217         xfs_daddr_t     d;      /* address of last block of subvolume */
2218         int             error;  /* error return value */
2219         xfs_sb_t        *sbp;   /* filesystem superblock copy in mount */
2220
2221         sbp = &mp->m_sb;
2222         if (sbp->sb_rblocks == 0)
2223                 return 0;
2224         if (mp->m_rtdev_targp == NULL) {
2225                 cmn_err(CE_WARN,
2226         "XFS: This filesystem has a realtime volume, use rtdev=device option");
2227                 return XFS_ERROR(ENODEV);
2228         }
2229         mp->m_rsumlevels = sbp->sb_rextslog + 1;
2230         mp->m_rsumsize =
2231                 (uint)sizeof(xfs_suminfo_t) * mp->m_rsumlevels *
2232                 sbp->sb_rbmblocks;
2233         mp->m_rsumsize = roundup(mp->m_rsumsize, sbp->sb_blocksize);
2234         mp->m_rbmip = mp->m_rsumip = NULL;
2235         /*
2236          * Check that the realtime section is an ok size.
2237          */
2238         d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
2239         if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_rblocks) {
2240                 cmn_err(CE_WARN, "XFS: realtime mount -- %llu != %llu",
2241                         (unsigned long long) XFS_BB_TO_FSB(mp, d),
2242                         (unsigned long long) mp->m_sb.sb_rblocks);
2243                 return XFS_ERROR(EFBIG);
2244         }
2245         error = xfs_read_buf(mp, mp->m_rtdev_targp,
2246                                 d - XFS_FSB_TO_BB(mp, 1),
2247                                 XFS_FSB_TO_BB(mp, 1), 0, &bp);
2248         if (error) {
2249                 cmn_err(CE_WARN,
2250         "XFS: realtime mount -- xfs_read_buf failed, returned %d", error);
2251                 if (error == ENOSPC)
2252                         return XFS_ERROR(EFBIG);
2253                 return error;
2254         }
2255         xfs_buf_relse(bp);
2256         return 0;
2257 }
2258
2259 /*
2260  * Get the bitmap and summary inodes into the mount structure
2261  * at mount time.
2262  */
2263 int                                     /* error */
2264 xfs_rtmount_inodes(
2265         xfs_mount_t     *mp)            /* file system mount structure */
2266 {
2267         int             error;          /* error return value */
2268         xfs_sb_t        *sbp;
2269
2270         sbp = &mp->m_sb;
2271         if (sbp->sb_rbmino == NULLFSINO)
2272                 return 0;
2273         error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip);
2274         if (error)
2275                 return error;
2276         ASSERT(mp->m_rbmip != NULL);
2277         ASSERT(sbp->sb_rsumino != NULLFSINO);
2278         error = xfs_iget(mp, NULL, sbp->sb_rsumino, 0, 0, &mp->m_rsumip);
2279         if (error) {
2280                 IRELE(mp->m_rbmip);
2281                 return error;
2282         }
2283         ASSERT(mp->m_rsumip != NULL);
2284         return 0;
2285 }
2286
2287 void
2288 xfs_rtunmount_inodes(
2289         struct xfs_mount        *mp)
2290 {
2291         if (mp->m_rbmip)
2292                 IRELE(mp->m_rbmip);
2293         if (mp->m_rsumip)
2294                 IRELE(mp->m_rsumip);
2295 }
2296
2297 /*
2298  * Pick an extent for allocation at the start of a new realtime file.
2299  * Use the sequence number stored in the atime field of the bitmap inode.
2300  * Translate this to a fraction of the rtextents, and return the product
2301  * of rtextents and the fraction.
2302  * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
2303  */
2304 int                                     /* error */
2305 xfs_rtpick_extent(
2306         xfs_mount_t     *mp,            /* file system mount point */
2307         xfs_trans_t     *tp,            /* transaction pointer */
2308         xfs_extlen_t    len,            /* allocation length (rtextents) */
2309         xfs_rtblock_t   *pick)          /* result rt extent */
2310 {
2311         xfs_rtblock_t   b;              /* result block */
2312         int             error;          /* error return value */
2313         xfs_inode_t     *ip;            /* bitmap incore inode */
2314         int             log2;           /* log of sequence number */
2315         __uint64_t      resid;          /* residual after log removed */
2316         __uint64_t      seq;            /* sequence number of file creation */
2317         __uint64_t      *seqp;          /* pointer to seqno in inode */
2318
2319         if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
2320                                         XFS_ILOCK_EXCL, &ip)))
2321                 return error;
2322         ASSERT(ip == mp->m_rbmip);
2323         seqp = (__uint64_t *)&ip->i_d.di_atime;
2324         if (!(ip->i_d.di_flags & XFS_DIFLAG_NEWRTBM)) {
2325                 ip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
2326                 *seqp = 0;
2327         }
2328         seq = *seqp;
2329         if ((log2 = xfs_highbit64(seq)) == -1)
2330                 b = 0;
2331         else {
2332                 resid = seq - (1ULL << log2);
2333                 b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >>
2334                     (log2 + 1);
2335                 if (b >= mp->m_sb.sb_rextents)
2336                         b = do_mod(b, mp->m_sb.sb_rextents);
2337                 if (b + len > mp->m_sb.sb_rextents)
2338                         b = mp->m_sb.sb_rextents - len;
2339         }
2340         *seqp = seq + 1;
2341         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2342         *pick = b;
2343         return 0;
2344 }