git.oblomov.eu Git - linux-2.6/blob - fs/xfs/xfs_fsops.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_inum.h"
  23 #include "xfs_log.h"
  24 #include "xfs_trans.h"
  25 #include "xfs_sb.h"
  26 #include "xfs_ag.h"
  27 #include "xfs_dir.h"
  28 #include "xfs_dir2.h"
  29 #include "xfs_dmapi.h"
  30 #include "xfs_mount.h"
  31 #include "xfs_bmap_btree.h"
  32 #include "xfs_alloc_btree.h"
  33 #include "xfs_ialloc_btree.h"
  34 #include "xfs_dir_sf.h"
  35 #include "xfs_dir2_sf.h"
  36 #include "xfs_attr_sf.h"
  37 #include "xfs_dinode.h"
  38 #include "xfs_inode.h"
  39 #include "xfs_inode_item.h"
  40 #include "xfs_btree.h"
  41 #include "xfs_error.h"
  42 #include "xfs_alloc.h"
  43 #include "xfs_ialloc.h"
  44 #include "xfs_fsops.h"
  45 #include "xfs_itable.h"
  46 #include "xfs_trans_space.h"
  47 #include "xfs_rtalloc.h"
  48 #include "xfs_rw.h"
  49
  50 /*
  51  * File system operations
  52  */
  53
  54 int
  55 xfs_fs_geometry(
  56         xfs_mount_t             *mp,
  57         xfs_fsop_geom_t         *geo,
  58         int                     new_version)
  59 {
  60         geo->blocksize = mp->m_sb.sb_blocksize;
  61         geo->rtextsize = mp->m_sb.sb_rextsize;
  62         geo->agblocks = mp->m_sb.sb_agblocks;
  63         geo->agcount = mp->m_sb.sb_agcount;
  64         geo->logblocks = mp->m_sb.sb_logblocks;
  65         geo->sectsize = mp->m_sb.sb_sectsize;
  66         geo->inodesize = mp->m_sb.sb_inodesize;
  67         geo->imaxpct = mp->m_sb.sb_imax_pct;
  68         geo->datablocks = mp->m_sb.sb_dblocks;
  69         geo->rtblocks = mp->m_sb.sb_rblocks;
  70         geo->rtextents = mp->m_sb.sb_rextents;
  71         geo->logstart = mp->m_sb.sb_logstart;
  72         ASSERT(sizeof(geo->uuid)==sizeof(mp->m_sb.sb_uuid));
  73         memcpy(geo->uuid, &mp->m_sb.sb_uuid, sizeof(mp->m_sb.sb_uuid));
  74         if (new_version >= 2) {
  75                 geo->sunit = mp->m_sb.sb_unit;
  76                 geo->swidth = mp->m_sb.sb_width;
  77         }
  78         if (new_version >= 3) {
  79                 geo->version = XFS_FSOP_GEOM_VERSION;
  80                 geo->flags =
  81                         (XFS_SB_VERSION_HASATTR(&mp->m_sb) ?
  82                                 XFS_FSOP_GEOM_FLAGS_ATTR : 0) |
  83                         (XFS_SB_VERSION_HASNLINK(&mp->m_sb) ?
  84                                 XFS_FSOP_GEOM_FLAGS_NLINK : 0) |
  85                         (XFS_SB_VERSION_HASQUOTA(&mp->m_sb) ?
  86                                 XFS_FSOP_GEOM_FLAGS_QUOTA : 0) |
  87                         (XFS_SB_VERSION_HASALIGN(&mp->m_sb) ?
  88                                 XFS_FSOP_GEOM_FLAGS_IALIGN : 0) |
  89                         (XFS_SB_VERSION_HASDALIGN(&mp->m_sb) ?
  90                                 XFS_FSOP_GEOM_FLAGS_DALIGN : 0) |
  91                         (XFS_SB_VERSION_HASSHARED(&mp->m_sb) ?
  92                                 XFS_FSOP_GEOM_FLAGS_SHARED : 0) |
  93                         (XFS_SB_VERSION_HASEXTFLGBIT(&mp->m_sb) ?
  94                                 XFS_FSOP_GEOM_FLAGS_EXTFLG : 0) |
  95                         (XFS_SB_VERSION_HASDIRV2(&mp->m_sb) ?
  96                                 XFS_FSOP_GEOM_FLAGS_DIRV2 : 0) |
  97                         (XFS_SB_VERSION_HASSECTOR(&mp->m_sb) ?
  98                                 XFS_FSOP_GEOM_FLAGS_SECTOR : 0) |
  99                         (XFS_SB_VERSION_HASATTR2(&mp->m_sb) ?
 100                                 XFS_FSOP_GEOM_FLAGS_ATTR2 : 0);
 101                 geo->logsectsize = XFS_SB_VERSION_HASSECTOR(&mp->m_sb) ?
 102                                 mp->m_sb.sb_logsectsize : BBSIZE;
 103                 geo->rtsectsize = mp->m_sb.sb_blocksize;
 104                 geo->dirblocksize = mp->m_dirblksize;
 105         }
 106         if (new_version >= 4) {
 107                 geo->flags |=
 108                         (XFS_SB_VERSION_HASLOGV2(&mp->m_sb) ?
 109                                 XFS_FSOP_GEOM_FLAGS_LOGV2 : 0);
 110                 geo->logsunit = mp->m_sb.sb_logsunit;
 111         }
 112         return 0;
 113 }
 114
 115 static int
 116 xfs_growfs_data_private(
 117         xfs_mount_t             *mp,            /* mount point for filesystem */
 118         xfs_growfs_data_t       *in)            /* growfs data input struct */
 119 {
 120         xfs_agf_t               *agf;
 121         xfs_agi_t               *agi;
 122         xfs_agnumber_t          agno;
 123         xfs_extlen_t            agsize;
 124         xfs_extlen_t            tmpsize;
 125         xfs_alloc_rec_t         *arec;
 126         xfs_btree_sblock_t      *block;
 127         xfs_buf_t               *bp;
 128         int                     bucket;
 129         int                     dpct;
 130         int                     error;
 131         xfs_agnumber_t          nagcount;
 132         xfs_agnumber_t          nagimax = 0;
 133         xfs_rfsblock_t          nb, nb_mod;
 134         xfs_rfsblock_t          new;
 135         xfs_rfsblock_t          nfree;
 136         xfs_agnumber_t          oagcount;
 137         int                     pct;
 138         xfs_sb_t                *sbp;
 139         xfs_trans_t             *tp;
 140
 141         nb = in->newblocks;
 142         pct = in->imaxpct;
 143         if (nb < mp->m_sb.sb_dblocks || pct < 0 || pct > 100)
 144                 return XFS_ERROR(EINVAL);
 145         dpct = pct - mp->m_sb.sb_imax_pct;
 146         error = xfs_read_buf(mp, mp->m_ddev_targp,
 147                         XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
 148                         XFS_FSS_TO_BB(mp, 1), 0, &bp);
 149         if (error)
 150                 return error;
 151         ASSERT(bp);
 152         xfs_buf_relse(bp);
 153
 154         new = nb;       /* use new as a temporary here */
 155         nb_mod = do_div(new, mp->m_sb.sb_agblocks);
 156         nagcount = new + (nb_mod != 0);
 157         if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
 158                 nagcount--;
 159                 nb = nagcount * mp->m_sb.sb_agblocks;
 160                 if (nb < mp->m_sb.sb_dblocks)
 161                         return XFS_ERROR(EINVAL);
 162         }
 163         new = nb - mp->m_sb.sb_dblocks;
 164         oagcount = mp->m_sb.sb_agcount;
 165         if (nagcount > oagcount) {
 166                 down_write(&mp->m_peraglock);
 167                 mp->m_perag = kmem_realloc(mp->m_perag,
 168                         sizeof(xfs_perag_t) * nagcount,
 169                         sizeof(xfs_perag_t) * oagcount,
 170                         KM_SLEEP);
 171                 memset(&mp->m_perag[oagcount], 0,
 172                         (nagcount - oagcount) * sizeof(xfs_perag_t));
 173                 mp->m_flags |= XFS_MOUNT_32BITINODES;
 174                 nagimax = xfs_initialize_perag(XFS_MTOVFS(mp), mp, nagcount);
 175                 up_write(&mp->m_peraglock);
 176         }
 177         tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFS);
 178         if ((error = xfs_trans_reserve(tp, XFS_GROWFS_SPACE_RES(mp),
 179                         XFS_GROWDATA_LOG_RES(mp), 0, 0, 0))) {
 180                 xfs_trans_cancel(tp, 0);
 181                 return error;
 182         }
 183
 184         nfree = 0;
 185         for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) {
 186                 /*
 187                  * AG freelist header block
 188                  */
 189                 bp = xfs_buf_get(mp->m_ddev_targp,
 190                                   XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
 191                                   XFS_FSS_TO_BB(mp, 1), 0);
 192                 agf = XFS_BUF_TO_AGF(bp);
 193                 memset(agf, 0, mp->m_sb.sb_sectsize);
 194                 agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
 195                 agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
 196                 agf->agf_seqno = cpu_to_be32(agno);
 197                 if (agno == nagcount - 1)
 198                         agsize =
 199                                 nb -
 200                                 (agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
 201                 else
 202                         agsize = mp->m_sb.sb_agblocks;
 203                 agf->agf_length = cpu_to_be32(agsize);
 204                 agf->agf_roots[XFS_BTNUM_BNOi] = cpu_to_be32(XFS_BNO_BLOCK(mp));
 205                 agf->agf_roots[XFS_BTNUM_CNTi] = cpu_to_be32(XFS_CNT_BLOCK(mp));
 206                 agf->agf_levels[XFS_BTNUM_BNOi] = cpu_to_be32(1);
 207                 agf->agf_levels[XFS_BTNUM_CNTi] = cpu_to_be32(1);
 208                 agf->agf_flfirst = 0;
 209                 agf->agf_fllast = cpu_to_be32(XFS_AGFL_SIZE(mp) - 1);
 210                 agf->agf_flcount = 0;
 211                 tmpsize = agsize - XFS_PREALLOC_BLOCKS(mp);
 212                 agf->agf_freeblks = cpu_to_be32(tmpsize);
 213                 agf->agf_longest = cpu_to_be32(tmpsize);
 214                 error = xfs_bwrite(mp, bp);
 215                 if (error) {
 216                         goto error0;
 217                 }
 218                 /*
 219                  * AG inode header block
 220                  */
 221                 bp = xfs_buf_get(mp->m_ddev_targp,
 222                                   XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
 223                                   XFS_FSS_TO_BB(mp, 1), 0);
 224                 agi = XFS_BUF_TO_AGI(bp);
 225                 memset(agi, 0, mp->m_sb.sb_sectsize);
 226                 agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
 227                 agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
 228                 agi->agi_seqno = cpu_to_be32(agno);
 229                 agi->agi_length = cpu_to_be32(agsize);
 230                 agi->agi_count = 0;
 231                 agi->agi_root = cpu_to_be32(XFS_IBT_BLOCK(mp));
 232                 agi->agi_level = cpu_to_be32(1);
 233                 agi->agi_freecount = 0;
 234                 agi->agi_newino = cpu_to_be32(NULLAGINO);
 235                 agi->agi_dirino = cpu_to_be32(NULLAGINO);
 236                 for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
 237                         agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
 238                 error = xfs_bwrite(mp, bp);
 239                 if (error) {
 240                         goto error0;
 241                 }
 242                 /*
 243                  * BNO btree root block
 244                  */
 245                 bp = xfs_buf_get(mp->m_ddev_targp,
 246                         XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
 247                         BTOBB(mp->m_sb.sb_blocksize), 0);
 248                 block = XFS_BUF_TO_SBLOCK(bp);
 249                 memset(block, 0, mp->m_sb.sb_blocksize);
 250                 block->bb_magic = cpu_to_be32(XFS_ABTB_MAGIC);
 251                 block->bb_level = 0;
 252                 block->bb_numrecs = cpu_to_be16(1);
 253                 block->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 254                 block->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 255                 arec = XFS_BTREE_REC_ADDR(mp->m_sb.sb_blocksize, xfs_alloc,
 256                         block, 1, mp->m_alloc_mxr[0]);
 257                 arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
 258                 arec->ar_blockcount = cpu_to_be32(
 259                         agsize - be32_to_cpu(arec->ar_startblock));
 260                 error = xfs_bwrite(mp, bp);
 261                 if (error) {
 262                         goto error0;
 263                 }
 264                 /*
 265                  * CNT btree root block
 266                  */
 267                 bp = xfs_buf_get(mp->m_ddev_targp,
 268                         XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
 269                         BTOBB(mp->m_sb.sb_blocksize), 0);
 270                 block = XFS_BUF_TO_SBLOCK(bp);
 271                 memset(block, 0, mp->m_sb.sb_blocksize);
 272                 block->bb_magic = cpu_to_be32(XFS_ABTC_MAGIC);
 273                 block->bb_level = 0;
 274                 block->bb_numrecs = cpu_to_be16(1);
 275                 block->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 276                 block->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 277                 arec = XFS_BTREE_REC_ADDR(mp->m_sb.sb_blocksize, xfs_alloc,
 278                         block, 1, mp->m_alloc_mxr[0]);
 279                 arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
 280                 arec->ar_blockcount = cpu_to_be32(
 281                         agsize - be32_to_cpu(arec->ar_startblock));
 282                 nfree += be32_to_cpu(arec->ar_blockcount);
 283                 error = xfs_bwrite(mp, bp);
 284                 if (error) {
 285                         goto error0;
 286                 }
 287                 /*
 288                  * INO btree root block
 289                  */
 290                 bp = xfs_buf_get(mp->m_ddev_targp,
 291                         XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
 292                         BTOBB(mp->m_sb.sb_blocksize), 0);
 293                 block = XFS_BUF_TO_SBLOCK(bp);
 294                 memset(block, 0, mp->m_sb.sb_blocksize);
 295                 block->bb_magic = cpu_to_be32(XFS_IBT_MAGIC);
 296                 block->bb_level = 0;
 297                 block->bb_numrecs = 0;
 298                 block->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 299                 block->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 300                 error = xfs_bwrite(mp, bp);
 301                 if (error) {
 302                         goto error0;
 303                 }
 304         }
 305         xfs_trans_agblocks_delta(tp, nfree);
 306         /*
 307          * There are new blocks in the old last a.g.
 308          */
 309         if (new) {
 310                 /*
 311                  * Change the agi length.
 312                  */
 313                 error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
 314                 if (error) {
 315                         goto error0;
 316                 }
 317                 ASSERT(bp);
 318                 agi = XFS_BUF_TO_AGI(bp);
 319                 be32_add(&agi->agi_length, new);
 320                 ASSERT(nagcount == oagcount ||
 321                        be32_to_cpu(agi->agi_length) == mp->m_sb.sb_agblocks);
 322                 xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
 323                 /*
 324                  * Change agf length.
 325                  */
 326                 error = xfs_alloc_read_agf(mp, tp, agno, 0, &bp);
 327                 if (error) {
 328                         goto error0;
 329                 }
 330                 ASSERT(bp);
 331                 agf = XFS_BUF_TO_AGF(bp);
 332                 be32_add(&agf->agf_length, new);
 333                 ASSERT(be32_to_cpu(agf->agf_length) ==
 334                        be32_to_cpu(agi->agi_length));
 335                 /*
 336                  * Free the new space.
 337                  */
 338                 error = xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, agno,
 339                         be32_to_cpu(agf->agf_length) - new), new);
 340                 if (error) {
 341                         goto error0;
 342                 }
 343         }
 344         if (nagcount > oagcount)
 345                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
 346         if (nb > mp->m_sb.sb_dblocks)
 347                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
 348                                  nb - mp->m_sb.sb_dblocks);
 349         if (nfree)
 350                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, nfree);
 351         if (dpct)
 352                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
 353         error = xfs_trans_commit(tp, 0, NULL);
 354         if (error) {
 355                 return error;
 356         }
 357         /* New allocation groups fully initialized, so update mount struct */
 358         if (nagimax)
 359                 mp->m_maxagi = nagimax;
 360         if (mp->m_sb.sb_imax_pct) {
 361                 __uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
 362                 do_div(icount, 100);
 363                 mp->m_maxicount = icount << mp->m_sb.sb_inopblog;
 364         } else
 365                 mp->m_maxicount = 0;
 366         for (agno = 1; agno < nagcount; agno++) {
 367                 error = xfs_read_buf(mp, mp->m_ddev_targp,
 368                                   XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
 369                                   XFS_FSS_TO_BB(mp, 1), 0, &bp);
 370                 if (error) {
 371                         xfs_fs_cmn_err(CE_WARN, mp,
 372                         "error %d reading secondary superblock for ag %d",
 373                                 error, agno);
 374                         break;
 375                 }
 376                 sbp = XFS_BUF_TO_SBP(bp);
 377                 xfs_xlatesb(sbp, &mp->m_sb, -1, XFS_SB_ALL_BITS);
 378                 /*
 379                  * If we get an error writing out the alternate superblocks,
 380                  * just issue a warning and continue.  The real work is
 381                  * already done and committed.
 382                  */
 383                 if (!(error = xfs_bwrite(mp, bp))) {
 384                         continue;
 385                 } else {
 386                         xfs_fs_cmn_err(CE_WARN, mp,
 387                 "write error %d updating secondary superblock for ag %d",
 388                                 error, agno);
 389                         break; /* no point in continuing */
 390                 }
 391         }
 392         return 0;
 393
 394  error0:
 395         xfs_trans_cancel(tp, XFS_TRANS_ABORT);
 396         return error;
 397 }
 398
 399 static int
 400 xfs_growfs_log_private(
 401         xfs_mount_t             *mp,    /* mount point for filesystem */
 402         xfs_growfs_log_t        *in)    /* growfs log input struct */
 403 {
 404         xfs_extlen_t            nb;
 405
 406         nb = in->newblocks;
 407         if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
 408                 return XFS_ERROR(EINVAL);
 409         if (nb == mp->m_sb.sb_logblocks &&
 410             in->isint == (mp->m_sb.sb_logstart != 0))
 411                 return XFS_ERROR(EINVAL);
 412         /*
 413          * Moving the log is hard, need new interfaces to sync
 414          * the log first, hold off all activity while moving it.
 415          * Can have shorter or longer log in the same space,
 416          * or transform internal to external log or vice versa.
 417          */
 418         return XFS_ERROR(ENOSYS);
 419 }
 420
 421 /*
 422  * protected versions of growfs function acquire and release locks on the mount
 423  * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
 424  * XFS_IOC_FSGROWFSRT
 425  */
 426
 427
 428 int
 429 xfs_growfs_data(
 430         xfs_mount_t             *mp,
 431         xfs_growfs_data_t       *in)
 432 {
 433         int error;
 434         if (!cpsema(&mp->m_growlock))
 435                 return XFS_ERROR(EWOULDBLOCK);
 436         error = xfs_growfs_data_private(mp, in);
 437         vsema(&mp->m_growlock);
 438         return error;
 439 }
 440
 441 int
 442 xfs_growfs_log(
 443         xfs_mount_t             *mp,
 444         xfs_growfs_log_t        *in)
 445 {
 446         int error;
 447         if (!cpsema(&mp->m_growlock))
 448                 return XFS_ERROR(EWOULDBLOCK);
 449         error = xfs_growfs_log_private(mp, in);
 450         vsema(&mp->m_growlock);
 451         return error;
 452 }
 453
 454 /*
 455  * exported through ioctl XFS_IOC_FSCOUNTS
 456  */
 457
 458 int
 459 xfs_fs_counts(
 460         xfs_mount_t             *mp,
 461         xfs_fsop_counts_t       *cnt)
 462 {
 463         unsigned long   s;
 464
 465         s = XFS_SB_LOCK(mp);
 466         cnt->freedata = mp->m_sb.sb_fdblocks;
 467         cnt->freertx = mp->m_sb.sb_frextents;
 468         cnt->freeino = mp->m_sb.sb_ifree;
 469         cnt->allocino = mp->m_sb.sb_icount;
 470         XFS_SB_UNLOCK(mp, s);
 471         return 0;
 472 }
 473
 474 /*
 475  * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
 476  *
 477  * xfs_reserve_blocks is called to set m_resblks
 478  * in the in-core mount table. The number of unused reserved blocks
 479  * is kept in m_resbls_avail.
 480  *
 481  * Reserve the requested number of blocks if available. Otherwise return
 482  * as many as possible to satisfy the request. The actual number
 483  * reserved are returned in outval
 484  *
 485  * A null inval pointer indicates that only the current reserved blocks
 486  * available  should  be returned no settings are changed.
 487  */
 488
 489 int
 490 xfs_reserve_blocks(
 491         xfs_mount_t             *mp,
 492         __uint64_t              *inval,
 493         xfs_fsop_resblks_t      *outval)
 494 {
 495         __int64_t               lcounter, delta;
 496         __uint64_t              request;
 497         unsigned long           s;
 498
 499         /* If inval is null, report current values and return */
 500
 501         if (inval == (__uint64_t *)NULL) {
 502                 outval->resblks = mp->m_resblks;
 503                 outval->resblks_avail = mp->m_resblks_avail;
 504                 return 0;
 505         }
 506
 507         request = *inval;
 508         s = XFS_SB_LOCK(mp);
 509
 510         /*
 511          * If our previous reservation was larger than the current value,
 512          * then move any unused blocks back to the free pool.
 513          */
 514
 515         if (mp->m_resblks > request) {
 516                 lcounter = mp->m_resblks_avail - request;
 517                 if (lcounter  > 0) {            /* release unused blocks */
 518                         mp->m_sb.sb_fdblocks += lcounter;
 519                         mp->m_resblks_avail -= lcounter;
 520                 }
 521                 mp->m_resblks = request;
 522         } else {
 523                 delta = request - mp->m_resblks;
 524                 lcounter = mp->m_sb.sb_fdblocks - delta;
 525                 if (lcounter < 0) {
 526                         /* We can't satisfy the request, just get what we can */
 527                         mp->m_resblks += mp->m_sb.sb_fdblocks;
 528                         mp->m_resblks_avail += mp->m_sb.sb_fdblocks;
 529                         mp->m_sb.sb_fdblocks = 0;
 530                 } else {
 531                         mp->m_sb.sb_fdblocks = lcounter;
 532                         mp->m_resblks = request;
 533                         mp->m_resblks_avail += delta;
 534                 }
 535         }
 536
 537         outval->resblks = mp->m_resblks;
 538         outval->resblks_avail = mp->m_resblks_avail;
 539         XFS_SB_UNLOCK(mp, s);
 540         return 0;
 541 }
 542
 543 void
 544 xfs_fs_log_dummy(xfs_mount_t *mp)
 545 {
 546         xfs_trans_t *tp;
 547         xfs_inode_t *ip;
 548
 549
 550         tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);
 551         atomic_inc(&mp->m_active_trans);
 552         if (xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0)) {
 553                 xfs_trans_cancel(tp, 0);
 554                 return;
 555         }
 556
 557         ip = mp->m_rootip;
 558         xfs_ilock(ip, XFS_ILOCK_EXCL);
 559
 560         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 561         xfs_trans_ihold(tp, ip);
 562         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 563         xfs_trans_set_sync(tp);
 564         xfs_trans_commit(tp, 0, NULL);
 565
 566         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 567 }
 568
 569 int
 570 xfs_fs_goingdown(
 571         xfs_mount_t     *mp,
 572         __uint32_t      inflags)
 573 {
 574         switch (inflags) {
 575         case XFS_FSOP_GOING_FLAGS_DEFAULT: {
 576                 struct vfs *vfsp = XFS_MTOVFS(mp);
 577                 struct super_block *sb = freeze_bdev(vfsp->vfs_super->s_bdev);
 578
 579                 if (sb && !IS_ERR(sb)) {
 580                         xfs_force_shutdown(mp, XFS_FORCE_UMOUNT);
 581                         thaw_bdev(sb->s_bdev, sb);
 582                 }
 583
 584                 break;
 585         }
 586         case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
 587                 xfs_force_shutdown(mp, XFS_FORCE_UMOUNT);
 588                 break;
 589         case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
 590                 xfs_force_shutdown(mp, XFS_FORCE_UMOUNT|XFS_LOG_IO_ERROR);
 591                 break;
 592         default:
 593                 return XFS_ERROR(EINVAL);
 594         }
 595
 596         return 0;
 597 }