SAFE public projects git trees. - safe/jmp/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(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                 INT_SET(agf->agf_magicnum, ARCH_CONVERT, XFS_AGF_MAGIC);
 195                 INT_SET(agf->agf_versionnum, ARCH_CONVERT, XFS_AGF_VERSION);
 196                 INT_SET(agf->agf_seqno, ARCH_CONVERT, 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                 INT_SET(agf->agf_length, ARCH_CONVERT, agsize);
 204                 INT_SET(agf->agf_roots[XFS_BTNUM_BNOi], ARCH_CONVERT,
 205                         XFS_BNO_BLOCK(mp));
 206                 INT_SET(agf->agf_roots[XFS_BTNUM_CNTi], ARCH_CONVERT,
 207                         XFS_CNT_BLOCK(mp));
 208                 INT_SET(agf->agf_levels[XFS_BTNUM_BNOi], ARCH_CONVERT, 1);
 209                 INT_SET(agf->agf_levels[XFS_BTNUM_CNTi], ARCH_CONVERT, 1);
 210                 agf->agf_flfirst = 0;
 211                 INT_SET(agf->agf_fllast, ARCH_CONVERT, XFS_AGFL_SIZE(mp) - 1);
 212                 agf->agf_flcount = 0;
 213                 tmpsize = agsize - XFS_PREALLOC_BLOCKS(mp);
 214                 INT_SET(agf->agf_freeblks, ARCH_CONVERT, tmpsize);
 215                 INT_SET(agf->agf_longest, ARCH_CONVERT, tmpsize);
 216                 error = xfs_bwrite(mp, bp);
 217                 if (error) {
 218                         goto error0;
 219                 }
 220                 /*
 221                  * AG inode header block
 222                  */
 223                 bp = xfs_buf_get(mp->m_ddev_targp,
 224                                   XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
 225                                   XFS_FSS_TO_BB(mp, 1), 0);
 226                 agi = XFS_BUF_TO_AGI(bp);
 227                 memset(agi, 0, mp->m_sb.sb_sectsize);
 228                 INT_SET(agi->agi_magicnum, ARCH_CONVERT, XFS_AGI_MAGIC);
 229                 INT_SET(agi->agi_versionnum, ARCH_CONVERT, XFS_AGI_VERSION);
 230                 INT_SET(agi->agi_seqno, ARCH_CONVERT, agno);
 231                 INT_SET(agi->agi_length, ARCH_CONVERT, agsize);
 232                 agi->agi_count = 0;
 233                 INT_SET(agi->agi_root, ARCH_CONVERT, XFS_IBT_BLOCK(mp));
 234                 INT_SET(agi->agi_level, ARCH_CONVERT, 1);
 235                 agi->agi_freecount = 0;
 236                 INT_SET(agi->agi_newino, ARCH_CONVERT, NULLAGINO);
 237                 INT_SET(agi->agi_dirino, ARCH_CONVERT, NULLAGINO);
 238                 for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
 239                         INT_SET(agi->agi_unlinked[bucket], ARCH_CONVERT,
 240                                 NULLAGINO);
 241                 error = xfs_bwrite(mp, bp);
 242                 if (error) {
 243                         goto error0;
 244                 }
 245                 /*
 246                  * BNO btree root block
 247                  */
 248                 bp = xfs_buf_get(mp->m_ddev_targp,
 249                         XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
 250                         BTOBB(mp->m_sb.sb_blocksize), 0);
 251                 block = XFS_BUF_TO_SBLOCK(bp);
 252                 memset(block, 0, mp->m_sb.sb_blocksize);
 253                 INT_SET(block->bb_magic, ARCH_CONVERT, XFS_ABTB_MAGIC);
 254                 block->bb_level = 0;
 255                 INT_SET(block->bb_numrecs, ARCH_CONVERT, 1);
 256                 INT_SET(block->bb_leftsib, ARCH_CONVERT, NULLAGBLOCK);
 257                 INT_SET(block->bb_rightsib, ARCH_CONVERT, NULLAGBLOCK);
 258                 arec = XFS_BTREE_REC_ADDR(mp->m_sb.sb_blocksize, xfs_alloc,
 259                         block, 1, mp->m_alloc_mxr[0]);
 260                 INT_SET(arec->ar_startblock, ARCH_CONVERT,
 261                         XFS_PREALLOC_BLOCKS(mp));
 262                 INT_SET(arec->ar_blockcount, ARCH_CONVERT,
 263                         agsize - INT_GET(arec->ar_startblock, ARCH_CONVERT));
 264                 error = xfs_bwrite(mp, bp);
 265                 if (error) {
 266                         goto error0;
 267                 }
 268                 /*
 269                  * CNT btree root block
 270                  */
 271                 bp = xfs_buf_get(mp->m_ddev_targp,
 272                         XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
 273                         BTOBB(mp->m_sb.sb_blocksize), 0);
 274                 block = XFS_BUF_TO_SBLOCK(bp);
 275                 memset(block, 0, mp->m_sb.sb_blocksize);
 276                 INT_SET(block->bb_magic, ARCH_CONVERT, XFS_ABTC_MAGIC);
 277                 block->bb_level = 0;
 278                 INT_SET(block->bb_numrecs, ARCH_CONVERT, 1);
 279                 INT_SET(block->bb_leftsib, ARCH_CONVERT, NULLAGBLOCK);
 280                 INT_SET(block->bb_rightsib, ARCH_CONVERT, NULLAGBLOCK);
 281                 arec = XFS_BTREE_REC_ADDR(mp->m_sb.sb_blocksize, xfs_alloc,
 282                         block, 1, mp->m_alloc_mxr[0]);
 283                 INT_SET(arec->ar_startblock, ARCH_CONVERT,
 284                         XFS_PREALLOC_BLOCKS(mp));
 285                 INT_SET(arec->ar_blockcount, ARCH_CONVERT,
 286                         agsize - INT_GET(arec->ar_startblock, ARCH_CONVERT));
 287                 nfree += INT_GET(arec->ar_blockcount, ARCH_CONVERT);
 288                 error = xfs_bwrite(mp, bp);
 289                 if (error) {
 290                         goto error0;
 291                 }
 292                 /*
 293                  * INO btree root block
 294                  */
 295                 bp = xfs_buf_get(mp->m_ddev_targp,
 296                         XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
 297                         BTOBB(mp->m_sb.sb_blocksize), 0);
 298                 block = XFS_BUF_TO_SBLOCK(bp);
 299                 memset(block, 0, mp->m_sb.sb_blocksize);
 300                 INT_SET(block->bb_magic, ARCH_CONVERT, XFS_IBT_MAGIC);
 301                 block->bb_level = 0;
 302                 block->bb_numrecs = 0;
 303                 INT_SET(block->bb_leftsib, ARCH_CONVERT, NULLAGBLOCK);
 304                 INT_SET(block->bb_rightsib, ARCH_CONVERT, NULLAGBLOCK);
 305                 error = xfs_bwrite(mp, bp);
 306                 if (error) {
 307                         goto error0;
 308                 }
 309         }
 310         xfs_trans_agblocks_delta(tp, nfree);
 311         /*
 312          * There are new blocks in the old last a.g.
 313          */
 314         if (new) {
 315                 /*
 316                  * Change the agi length.
 317                  */
 318                 error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
 319                 if (error) {
 320                         goto error0;
 321                 }
 322                 ASSERT(bp);
 323                 agi = XFS_BUF_TO_AGI(bp);
 324                 INT_MOD(agi->agi_length, ARCH_CONVERT, new);
 325                 ASSERT(nagcount == oagcount ||
 326                        INT_GET(agi->agi_length, ARCH_CONVERT) ==
 327                                 mp->m_sb.sb_agblocks);
 328                 xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
 329                 /*
 330                  * Change agf length.
 331                  */
 332                 error = xfs_alloc_read_agf(mp, tp, agno, 0, &bp);
 333                 if (error) {
 334                         goto error0;
 335                 }
 336                 ASSERT(bp);
 337                 agf = XFS_BUF_TO_AGF(bp);
 338                 INT_MOD(agf->agf_length, ARCH_CONVERT, new);
 339                 ASSERT(INT_GET(agf->agf_length, ARCH_CONVERT) ==
 340                                 INT_GET(agi->agi_length, ARCH_CONVERT));
 341                 /*
 342                  * Free the new space.
 343                  */
 344                 error = xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, agno,
 345                         INT_GET(agf->agf_length, ARCH_CONVERT) - new), new);
 346                 if (error) {
 347                         goto error0;
 348                 }
 349         }
 350         if (nagcount > oagcount)
 351                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
 352         if (nb > mp->m_sb.sb_dblocks)
 353                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
 354                                  nb - mp->m_sb.sb_dblocks);
 355         if (nfree)
 356                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, nfree);
 357         if (dpct)
 358                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
 359         error = xfs_trans_commit(tp, 0, NULL);
 360         if (error) {
 361                 return error;
 362         }
 363         /* New allocation groups fully initialized, so update mount struct */
 364         if (nagimax)
 365                 mp->m_maxagi = nagimax;
 366         if (mp->m_sb.sb_imax_pct) {
 367                 __uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
 368                 do_div(icount, 100);
 369                 mp->m_maxicount = icount << mp->m_sb.sb_inopblog;
 370         } else
 371                 mp->m_maxicount = 0;
 372         for (agno = 1; agno < nagcount; agno++) {
 373                 error = xfs_read_buf(mp, mp->m_ddev_targp,
 374                                   XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
 375                                   XFS_FSS_TO_BB(mp, 1), 0, &bp);
 376                 if (error) {
 377                         xfs_fs_cmn_err(CE_WARN, mp,
 378                         "error %d reading secondary superblock for ag %d",
 379                                 error, agno);
 380                         break;
 381                 }
 382                 sbp = XFS_BUF_TO_SBP(bp);
 383                 xfs_xlatesb(sbp, &mp->m_sb, -1, XFS_SB_ALL_BITS);
 384                 /*
 385                  * If we get an error writing out the alternate superblocks,
 386                  * just issue a warning and continue.  The real work is
 387                  * already done and committed.
 388                  */
 389                 if (!(error = xfs_bwrite(mp, bp))) {
 390                         continue;
 391                 } else {
 392                         xfs_fs_cmn_err(CE_WARN, mp,
 393                 "write error %d updating secondary superblock for ag %d",
 394                                 error, agno);
 395                         break; /* no point in continuing */
 396                 }
 397         }
 398         return 0;
 399
 400  error0:
 401         xfs_trans_cancel(tp, XFS_TRANS_ABORT);
 402         return error;
 403 }
 404
 405 static int
 406 xfs_growfs_log_private(
 407         xfs_mount_t             *mp,    /* mount point for filesystem */
 408         xfs_growfs_log_t        *in)    /* growfs log input struct */
 409 {
 410         xfs_extlen_t            nb;
 411
 412         nb = in->newblocks;
 413         if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
 414                 return XFS_ERROR(EINVAL);
 415         if (nb == mp->m_sb.sb_logblocks &&
 416             in->isint == (mp->m_sb.sb_logstart != 0))
 417                 return XFS_ERROR(EINVAL);
 418         /*
 419          * Moving the log is hard, need new interfaces to sync
 420          * the log first, hold off all activity while moving it.
 421          * Can have shorter or longer log in the same space,
 422          * or transform internal to external log or vice versa.
 423          */
 424         return XFS_ERROR(ENOSYS);
 425 }
 426
 427 /*
 428  * protected versions of growfs function acquire and release locks on the mount
 429  * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
 430  * XFS_IOC_FSGROWFSRT
 431  */
 432
 433
 434 int
 435 xfs_growfs_data(
 436         xfs_mount_t             *mp,
 437         xfs_growfs_data_t       *in)
 438 {
 439         int error;
 440         if (!cpsema(&mp->m_growlock))
 441                 return XFS_ERROR(EWOULDBLOCK);
 442         error = xfs_growfs_data_private(mp, in);
 443         vsema(&mp->m_growlock);
 444         return error;
 445 }
 446
 447 int
 448 xfs_growfs_log(
 449         xfs_mount_t             *mp,
 450         xfs_growfs_log_t        *in)
 451 {
 452         int error;
 453         if (!cpsema(&mp->m_growlock))
 454                 return XFS_ERROR(EWOULDBLOCK);
 455         error = xfs_growfs_log_private(mp, in);
 456         vsema(&mp->m_growlock);
 457         return error;
 458 }
 459
 460 /*
 461  * exported through ioctl XFS_IOC_FSCOUNTS
 462  */
 463
 464 int
 465 xfs_fs_counts(
 466         xfs_mount_t             *mp,
 467         xfs_fsop_counts_t       *cnt)
 468 {
 469         unsigned long   s;
 470
 471         s = XFS_SB_LOCK(mp);
 472         cnt->freedata = mp->m_sb.sb_fdblocks;
 473         cnt->freertx = mp->m_sb.sb_frextents;
 474         cnt->freeino = mp->m_sb.sb_ifree;
 475         cnt->allocino = mp->m_sb.sb_icount;
 476         XFS_SB_UNLOCK(mp, s);
 477         return 0;
 478 }
 479
 480 /*
 481  * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
 482  *
 483  * xfs_reserve_blocks is called to set m_resblks
 484  * in the in-core mount table. The number of unused reserved blocks
 485  * is kept in m_resbls_avail.
 486  *
 487  * Reserve the requested number of blocks if available. Otherwise return
 488  * as many as possible to satisfy the request. The actual number
 489  * reserved are returned in outval
 490  *
 491  * A null inval pointer indicates that only the current reserved blocks
 492  * available  should  be returned no settings are changed.
 493  */
 494
 495 int
 496 xfs_reserve_blocks(
 497         xfs_mount_t             *mp,
 498         __uint64_t              *inval,
 499         xfs_fsop_resblks_t      *outval)
 500 {
 501         __int64_t               lcounter, delta;
 502         __uint64_t              request;
 503         unsigned long           s;
 504
 505         /* If inval is null, report current values and return */
 506
 507         if (inval == (__uint64_t *)NULL) {
 508                 outval->resblks = mp->m_resblks;
 509                 outval->resblks_avail = mp->m_resblks_avail;
 510                 return(0);
 511         }
 512
 513         request = *inval;
 514         s = XFS_SB_LOCK(mp);
 515
 516         /*
 517          * If our previous reservation was larger than the current value,
 518          * then move any unused blocks back to the free pool.
 519          */
 520
 521         if (mp->m_resblks > request) {
 522                 lcounter = mp->m_resblks_avail - request;
 523                 if (lcounter  > 0) {            /* release unused blocks */
 524                         mp->m_sb.sb_fdblocks += lcounter;
 525                         mp->m_resblks_avail -= lcounter;
 526                 }
 527                 mp->m_resblks = request;
 528         } else {
 529                 delta = request - mp->m_resblks;
 530                 lcounter = mp->m_sb.sb_fdblocks - delta;
 531                 if (lcounter < 0) {
 532                         /* We can't satisfy the request, just get what we can */
 533                         mp->m_resblks += mp->m_sb.sb_fdblocks;
 534                         mp->m_resblks_avail += mp->m_sb.sb_fdblocks;
 535                         mp->m_sb.sb_fdblocks = 0;
 536                 } else {
 537                         mp->m_sb.sb_fdblocks = lcounter;
 538                         mp->m_resblks = request;
 539                         mp->m_resblks_avail += delta;
 540                 }
 541         }
 542
 543         outval->resblks = mp->m_resblks;
 544         outval->resblks_avail = mp->m_resblks_avail;
 545         XFS_SB_UNLOCK(mp, s);
 546         return(0);
 547 }
 548
 549 int
 550 xfs_fs_goingdown(
 551         xfs_mount_t     *mp,
 552         __uint32_t      inflags)
 553 {
 554         switch (inflags) {
 555         case XFS_FSOP_GOING_FLAGS_DEFAULT: {
 556                 struct vfs *vfsp = XFS_MTOVFS(mp);
 557                 struct super_block *sb = freeze_bdev(vfsp->vfs_super->s_bdev);
 558
 559                 if (sb) {
 560                         xfs_force_shutdown(mp, XFS_FORCE_UMOUNT);
 561                         thaw_bdev(sb->s_bdev, sb);
 562                 }
 563
 564                 break;
 565         }
 566         case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
 567                 xfs_force_shutdown(mp, XFS_FORCE_UMOUNT);
 568                 break;
 569         case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
 570                 xfs_force_shutdown(mp, XFS_FORCE_UMOUNT|XFS_LOG_IO_ERROR);
 571                 break;
 572         default:
 573                 return XFS_ERROR(EINVAL);
 574         }
 575
 576         return 0;
 577 }