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_mount.h"
  28 #include "xfs_bmap_btree.h"
  29 #include "xfs_alloc_btree.h"
  30 #include "xfs_ialloc_btree.h"
  31 #include "xfs_dinode.h"
  32 #include "xfs_inode.h"
  33 #include "xfs_inode_item.h"
  34 #include "xfs_btree.h"
  35 #include "xfs_error.h"
  36 #include "xfs_alloc.h"
  37 #include "xfs_ialloc.h"
  38 #include "xfs_fsops.h"
  39 #include "xfs_itable.h"
  40 #include "xfs_trans_space.h"
  41 #include "xfs_rtalloc.h"
  42 #include "xfs_rw.h"
  43 #include "xfs_filestream.h"
  44 #include "xfs_trace.h"
  45
  46 /*
  47  * File system operations
  48  */
  49
  50 int
  51 xfs_fs_geometry(
  52         xfs_mount_t             *mp,
  53         xfs_fsop_geom_t         *geo,
  54         int                     new_version)
  55 {
  56
  57         memset(geo, 0, sizeof(*geo));
  58
  59         geo->blocksize = mp->m_sb.sb_blocksize;
  60         geo->rtextsize = mp->m_sb.sb_rextsize;
  61         geo->agblocks = mp->m_sb.sb_agblocks;
  62         geo->agcount = mp->m_sb.sb_agcount;
  63         geo->logblocks = mp->m_sb.sb_logblocks;
  64         geo->sectsize = mp->m_sb.sb_sectsize;
  65         geo->inodesize = mp->m_sb.sb_inodesize;
  66         geo->imaxpct = mp->m_sb.sb_imax_pct;
  67         geo->datablocks = mp->m_sb.sb_dblocks;
  68         geo->rtblocks = mp->m_sb.sb_rblocks;
  69         geo->rtextents = mp->m_sb.sb_rextents;
  70         geo->logstart = mp->m_sb.sb_logstart;
  71         ASSERT(sizeof(geo->uuid)==sizeof(mp->m_sb.sb_uuid));
  72         memcpy(geo->uuid, &mp->m_sb.sb_uuid, sizeof(mp->m_sb.sb_uuid));
  73         if (new_version >= 2) {
  74                 geo->sunit = mp->m_sb.sb_unit;
  75                 geo->swidth = mp->m_sb.sb_width;
  76         }
  77         if (new_version >= 3) {
  78                 geo->version = XFS_FSOP_GEOM_VERSION;
  79                 geo->flags =
  80                         (xfs_sb_version_hasattr(&mp->m_sb) ?
  81                                 XFS_FSOP_GEOM_FLAGS_ATTR : 0) |
  82                         (xfs_sb_version_hasnlink(&mp->m_sb) ?
  83                                 XFS_FSOP_GEOM_FLAGS_NLINK : 0) |
  84                         (xfs_sb_version_hasquota(&mp->m_sb) ?
  85                                 XFS_FSOP_GEOM_FLAGS_QUOTA : 0) |
  86                         (xfs_sb_version_hasalign(&mp->m_sb) ?
  87                                 XFS_FSOP_GEOM_FLAGS_IALIGN : 0) |
  88                         (xfs_sb_version_hasdalign(&mp->m_sb) ?
  89                                 XFS_FSOP_GEOM_FLAGS_DALIGN : 0) |
  90                         (xfs_sb_version_hasshared(&mp->m_sb) ?
  91                                 XFS_FSOP_GEOM_FLAGS_SHARED : 0) |
  92                         (xfs_sb_version_hasextflgbit(&mp->m_sb) ?
  93                                 XFS_FSOP_GEOM_FLAGS_EXTFLG : 0) |
  94                         (xfs_sb_version_hasdirv2(&mp->m_sb) ?
  95                                 XFS_FSOP_GEOM_FLAGS_DIRV2 : 0) |
  96                         (xfs_sb_version_hassector(&mp->m_sb) ?
  97                                 XFS_FSOP_GEOM_FLAGS_SECTOR : 0) |
  98                         (xfs_sb_version_hasasciici(&mp->m_sb) ?
  99                                 XFS_FSOP_GEOM_FLAGS_DIRV2CI : 0) |
 100                         (xfs_sb_version_haslazysbcount(&mp->m_sb) ?
 101                                 XFS_FSOP_GEOM_FLAGS_LAZYSB : 0) |
 102                         (xfs_sb_version_hasattr2(&mp->m_sb) ?
 103                                 XFS_FSOP_GEOM_FLAGS_ATTR2 : 0);
 104                 geo->logsectsize = xfs_sb_version_hassector(&mp->m_sb) ?
 105                                 mp->m_sb.sb_logsectsize : BBSIZE;
 106                 geo->rtsectsize = mp->m_sb.sb_blocksize;
 107                 geo->dirblocksize = mp->m_dirblksize;
 108         }
 109         if (new_version >= 4) {
 110                 geo->flags |=
 111                         (xfs_sb_version_haslogv2(&mp->m_sb) ?
 112                                 XFS_FSOP_GEOM_FLAGS_LOGV2 : 0);
 113                 geo->logsunit = mp->m_sb.sb_logsunit;
 114         }
 115         return 0;
 116 }
 117
 118 static int
 119 xfs_growfs_data_private(
 120         xfs_mount_t             *mp,            /* mount point for filesystem */
 121         xfs_growfs_data_t       *in)            /* growfs data input struct */
 122 {
 123         xfs_agf_t               *agf;
 124         xfs_agi_t               *agi;
 125         xfs_agnumber_t          agno;
 126         xfs_extlen_t            agsize;
 127         xfs_extlen_t            tmpsize;
 128         xfs_alloc_rec_t         *arec;
 129         struct xfs_btree_block  *block;
 130         xfs_buf_t               *bp;
 131         int                     bucket;
 132         int                     dpct;
 133         int                     error;
 134         xfs_agnumber_t          nagcount;
 135         xfs_agnumber_t          nagimax = 0;
 136         xfs_rfsblock_t          nb, nb_mod;
 137         xfs_rfsblock_t          new;
 138         xfs_rfsblock_t          nfree;
 139         xfs_agnumber_t          oagcount;
 140         int                     pct;
 141         xfs_trans_t             *tp;
 142
 143         nb = in->newblocks;
 144         pct = in->imaxpct;
 145         if (nb < mp->m_sb.sb_dblocks || pct < 0 || pct > 100)
 146                 return XFS_ERROR(EINVAL);
 147         if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
 148                 return error;
 149         dpct = pct - mp->m_sb.sb_imax_pct;
 150         bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
 151                                 XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
 152                                 BBTOB(XFS_FSS_TO_BB(mp, 1)), 0);
 153         if (!bp)
 154                 return EIO;
 155         xfs_buf_relse(bp);
 156
 157         new = nb;       /* use new as a temporary here */
 158         nb_mod = do_div(new, mp->m_sb.sb_agblocks);
 159         nagcount = new + (nb_mod != 0);
 160         if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
 161                 nagcount--;
 162                 nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
 163                 if (nb < mp->m_sb.sb_dblocks)
 164                         return XFS_ERROR(EINVAL);
 165         }
 166         new = nb - mp->m_sb.sb_dblocks;
 167         oagcount = mp->m_sb.sb_agcount;
 168
 169         /* allocate the new per-ag structures */
 170         if (nagcount > oagcount) {
 171                 error = xfs_initialize_perag(mp, nagcount, &nagimax);
 172                 if (error)
 173                         return error;
 174         }
 175
 176         tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFS);
 177         tp->t_flags |= XFS_TRANS_RESERVE;
 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         /*
 185          * Write new AG headers to disk. Non-transactional, but written
 186          * synchronously so they are completed prior to the growfs transaction
 187          * being logged.
 188          */
 189         nfree = 0;
 190         for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) {
 191                 /*
 192                  * AG freelist header block
 193                  */
 194                 bp = xfs_buf_get(mp->m_ddev_targp,
 195                                  XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
 196                                  XFS_FSS_TO_BB(mp, 1), XBF_LOCK | XBF_MAPPED);
 197                 if (!bp) {
 198                         error = ENOMEM;
 199                         goto error0;
 200                 }
 201                 agf = XFS_BUF_TO_AGF(bp);
 202                 memset(agf, 0, mp->m_sb.sb_sectsize);
 203                 agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
 204                 agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
 205                 agf->agf_seqno = cpu_to_be32(agno);
 206                 if (agno == nagcount - 1)
 207                         agsize =
 208                                 nb -
 209                                 (agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
 210                 else
 211                         agsize = mp->m_sb.sb_agblocks;
 212                 agf->agf_length = cpu_to_be32(agsize);
 213                 agf->agf_roots[XFS_BTNUM_BNOi] = cpu_to_be32(XFS_BNO_BLOCK(mp));
 214                 agf->agf_roots[XFS_BTNUM_CNTi] = cpu_to_be32(XFS_CNT_BLOCK(mp));
 215                 agf->agf_levels[XFS_BTNUM_BNOi] = cpu_to_be32(1);
 216                 agf->agf_levels[XFS_BTNUM_CNTi] = cpu_to_be32(1);
 217                 agf->agf_flfirst = 0;
 218                 agf->agf_fllast = cpu_to_be32(XFS_AGFL_SIZE(mp) - 1);
 219                 agf->agf_flcount = 0;
 220                 tmpsize = agsize - XFS_PREALLOC_BLOCKS(mp);
 221                 agf->agf_freeblks = cpu_to_be32(tmpsize);
 222                 agf->agf_longest = cpu_to_be32(tmpsize);
 223                 error = xfs_bwrite(bp);
 224                 xfs_buf_relse(bp);
 225                 if (error)
 226                         goto error0;
 227
 228                 /*
 229                  * AG inode header block
 230                  */
 231                 bp = xfs_buf_get(mp->m_ddev_targp,
 232                                  XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
 233                                  XFS_FSS_TO_BB(mp, 1), XBF_LOCK | XBF_MAPPED);
 234                 if (!bp) {
 235                         error = ENOMEM;
 236                         goto error0;
 237                 }
 238                 agi = XFS_BUF_TO_AGI(bp);
 239                 memset(agi, 0, mp->m_sb.sb_sectsize);
 240                 agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
 241                 agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
 242                 agi->agi_seqno = cpu_to_be32(agno);
 243                 agi->agi_length = cpu_to_be32(agsize);
 244                 agi->agi_count = 0;
 245                 agi->agi_root = cpu_to_be32(XFS_IBT_BLOCK(mp));
 246                 agi->agi_level = cpu_to_be32(1);
 247                 agi->agi_freecount = 0;
 248                 agi->agi_newino = cpu_to_be32(NULLAGINO);
 249                 agi->agi_dirino = cpu_to_be32(NULLAGINO);
 250                 for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
 251                         agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
 252                 error = xfs_bwrite(bp);
 253                 xfs_buf_relse(bp);
 254                 if (error)
 255                         goto error0;
 256
 257                 /*
 258                  * BNO btree root block
 259                  */
 260                 bp = xfs_buf_get(mp->m_ddev_targp,
 261                                  XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
 262                                  BTOBB(mp->m_sb.sb_blocksize),
 263                                  XBF_LOCK | XBF_MAPPED);
 264                 if (!bp) {
 265                         error = ENOMEM;
 266                         goto error0;
 267                 }
 268                 block = XFS_BUF_TO_BLOCK(bp);
 269                 memset(block, 0, mp->m_sb.sb_blocksize);
 270                 block->bb_magic = cpu_to_be32(XFS_ABTB_MAGIC);
 271                 block->bb_level = 0;
 272                 block->bb_numrecs = cpu_to_be16(1);
 273                 block->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 274                 block->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 275                 arec = XFS_ALLOC_REC_ADDR(mp, block, 1);
 276                 arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
 277                 arec->ar_blockcount = cpu_to_be32(
 278                         agsize - be32_to_cpu(arec->ar_startblock));
 279                 error = xfs_bwrite(bp);
 280                 xfs_buf_relse(bp);
 281                 if (error)
 282                         goto error0;
 283
 284                 /*
 285                  * CNT btree root block
 286                  */
 287                 bp = xfs_buf_get(mp->m_ddev_targp,
 288                                  XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
 289                                  BTOBB(mp->m_sb.sb_blocksize),
 290                                  XBF_LOCK | XBF_MAPPED);
 291                 if (!bp) {
 292                         error = ENOMEM;
 293                         goto error0;
 294                 }
 295                 block = XFS_BUF_TO_BLOCK(bp);
 296                 memset(block, 0, mp->m_sb.sb_blocksize);
 297                 block->bb_magic = cpu_to_be32(XFS_ABTC_MAGIC);
 298                 block->bb_level = 0;
 299                 block->bb_numrecs = cpu_to_be16(1);
 300                 block->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 301                 block->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 302                 arec = XFS_ALLOC_REC_ADDR(mp, block, 1);
 303                 arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
 304                 arec->ar_blockcount = cpu_to_be32(
 305                         agsize - be32_to_cpu(arec->ar_startblock));
 306                 nfree += be32_to_cpu(arec->ar_blockcount);
 307                 error = xfs_bwrite(bp);
 308                 xfs_buf_relse(bp);
 309                 if (error)
 310                         goto error0;
 311
 312                 /*
 313                  * INO btree root block
 314                  */
 315                 bp = xfs_buf_get(mp->m_ddev_targp,
 316                                  XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
 317                                  BTOBB(mp->m_sb.sb_blocksize),
 318                                  XBF_LOCK | XBF_MAPPED);
 319                 if (!bp) {
 320                         error = ENOMEM;
 321                         goto error0;
 322                 }
 323                 block = XFS_BUF_TO_BLOCK(bp);
 324                 memset(block, 0, mp->m_sb.sb_blocksize);
 325                 block->bb_magic = cpu_to_be32(XFS_IBT_MAGIC);
 326                 block->bb_level = 0;
 327                 block->bb_numrecs = 0;
 328                 block->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 329                 block->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 330                 error = xfs_bwrite(bp);
 331                 xfs_buf_relse(bp);
 332                 if (error)
 333                         goto error0;
 334         }
 335         xfs_trans_agblocks_delta(tp, nfree);
 336         /*
 337          * There are new blocks in the old last a.g.
 338          */
 339         if (new) {
 340                 /*
 341                  * Change the agi length.
 342                  */
 343                 error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
 344                 if (error) {
 345                         goto error0;
 346                 }
 347                 ASSERT(bp);
 348                 agi = XFS_BUF_TO_AGI(bp);
 349                 be32_add_cpu(&agi->agi_length, new);
 350                 ASSERT(nagcount == oagcount ||
 351                        be32_to_cpu(agi->agi_length) == mp->m_sb.sb_agblocks);
 352                 xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
 353                 /*
 354                  * Change agf length.
 355                  */
 356                 error = xfs_alloc_read_agf(mp, tp, agno, 0, &bp);
 357                 if (error) {
 358                         goto error0;
 359                 }
 360                 ASSERT(bp);
 361                 agf = XFS_BUF_TO_AGF(bp);
 362                 be32_add_cpu(&agf->agf_length, new);
 363                 ASSERT(be32_to_cpu(agf->agf_length) ==
 364                        be32_to_cpu(agi->agi_length));
 365
 366                 xfs_alloc_log_agf(tp, bp, XFS_AGF_LENGTH);
 367                 /*
 368                  * Free the new space.
 369                  */
 370                 error = xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, agno,
 371                         be32_to_cpu(agf->agf_length) - new), new);
 372                 if (error) {
 373                         goto error0;
 374                 }
 375         }
 376
 377         /*
 378          * Update changed superblock fields transactionally. These are not
 379          * seen by the rest of the world until the transaction commit applies
 380          * them atomically to the superblock.
 381          */
 382         if (nagcount > oagcount)
 383                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
 384         if (nb > mp->m_sb.sb_dblocks)
 385                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
 386                                  nb - mp->m_sb.sb_dblocks);
 387         if (nfree)
 388                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, nfree);
 389         if (dpct)
 390                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
 391         error = xfs_trans_commit(tp, 0);
 392         if (error)
 393                 return error;
 394
 395         /* New allocation groups fully initialized, so update mount struct */
 396         if (nagimax)
 397                 mp->m_maxagi = nagimax;
 398         if (mp->m_sb.sb_imax_pct) {
 399                 __uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
 400                 do_div(icount, 100);
 401                 mp->m_maxicount = icount << mp->m_sb.sb_inopblog;
 402         } else
 403                 mp->m_maxicount = 0;
 404         xfs_set_low_space_thresholds(mp);
 405
 406         /* update secondary superblocks. */
 407         for (agno = 1; agno < nagcount; agno++) {
 408                 error = xfs_read_buf(mp, mp->m_ddev_targp,
 409                                   XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
 410                                   XFS_FSS_TO_BB(mp, 1), 0, &bp);
 411                 if (error) {
 412                         xfs_warn(mp,
 413                 "error %d reading secondary superblock for ag %d",
 414                                 error, agno);
 415                         break;
 416                 }
 417                 xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, XFS_SB_ALL_BITS);
 418                 /*
 419                  * If we get an error writing out the alternate superblocks,
 420                  * just issue a warning and continue.  The real work is
 421                  * already done and committed.
 422                  */
 423                 error = xfs_bwrite(bp);
 424                 xfs_buf_relse(bp);
 425                 if (error) {
 426                         xfs_warn(mp,
 427                 "write error %d updating secondary superblock for ag %d",
 428                                 error, agno);
 429                         break; /* no point in continuing */
 430                 }
 431         }
 432         return 0;
 433
 434  error0:
 435         xfs_trans_cancel(tp, XFS_TRANS_ABORT);
 436         return error;
 437 }
 438
 439 static int
 440 xfs_growfs_log_private(
 441         xfs_mount_t             *mp,    /* mount point for filesystem */
 442         xfs_growfs_log_t        *in)    /* growfs log input struct */
 443 {
 444         xfs_extlen_t            nb;
 445
 446         nb = in->newblocks;
 447         if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
 448                 return XFS_ERROR(EINVAL);
 449         if (nb == mp->m_sb.sb_logblocks &&
 450             in->isint == (mp->m_sb.sb_logstart != 0))
 451                 return XFS_ERROR(EINVAL);
 452         /*
 453          * Moving the log is hard, need new interfaces to sync
 454          * the log first, hold off all activity while moving it.
 455          * Can have shorter or longer log in the same space,
 456          * or transform internal to external log or vice versa.
 457          */
 458         return XFS_ERROR(ENOSYS);
 459 }
 460
 461 /*
 462  * protected versions of growfs function acquire and release locks on the mount
 463  * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
 464  * XFS_IOC_FSGROWFSRT
 465  */
 466
 467
 468 int
 469 xfs_growfs_data(
 470         xfs_mount_t             *mp,
 471         xfs_growfs_data_t       *in)
 472 {
 473         int error;
 474
 475         if (!capable(CAP_SYS_ADMIN))
 476                 return XFS_ERROR(EPERM);
 477         if (!mutex_trylock(&mp->m_growlock))
 478                 return XFS_ERROR(EWOULDBLOCK);
 479         error = xfs_growfs_data_private(mp, in);
 480         mutex_unlock(&mp->m_growlock);
 481         return error;
 482 }
 483
 484 int
 485 xfs_growfs_log(
 486         xfs_mount_t             *mp,
 487         xfs_growfs_log_t        *in)
 488 {
 489         int error;
 490
 491         if (!capable(CAP_SYS_ADMIN))
 492                 return XFS_ERROR(EPERM);
 493         if (!mutex_trylock(&mp->m_growlock))
 494                 return XFS_ERROR(EWOULDBLOCK);
 495         error = xfs_growfs_log_private(mp, in);
 496         mutex_unlock(&mp->m_growlock);
 497         return error;
 498 }
 499
 500 /*
 501  * exported through ioctl XFS_IOC_FSCOUNTS
 502  */
 503
 504 int
 505 xfs_fs_counts(
 506         xfs_mount_t             *mp,
 507         xfs_fsop_counts_t       *cnt)
 508 {
 509         xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);
 510         spin_lock(&mp->m_sb_lock);
 511         cnt->freedata = mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
 512         cnt->freertx = mp->m_sb.sb_frextents;
 513         cnt->freeino = mp->m_sb.sb_ifree;
 514         cnt->allocino = mp->m_sb.sb_icount;
 515         spin_unlock(&mp->m_sb_lock);
 516         return 0;
 517 }
 518
 519 /*
 520  * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
 521  *
 522  * xfs_reserve_blocks is called to set m_resblks
 523  * in the in-core mount table. The number of unused reserved blocks
 524  * is kept in m_resblks_avail.
 525  *
 526  * Reserve the requested number of blocks if available. Otherwise return
 527  * as many as possible to satisfy the request. The actual number
 528  * reserved are returned in outval
 529  *
 530  * A null inval pointer indicates that only the current reserved blocks
 531  * available  should  be returned no settings are changed.
 532  */
 533
 534 int
 535 xfs_reserve_blocks(
 536         xfs_mount_t             *mp,
 537         __uint64_t              *inval,
 538         xfs_fsop_resblks_t      *outval)
 539 {
 540         __int64_t               lcounter, delta, fdblks_delta;
 541         __uint64_t              request;
 542
 543         /* If inval is null, report current values and return */
 544         if (inval == (__uint64_t *)NULL) {
 545                 if (!outval)
 546                         return EINVAL;
 547                 outval->resblks = mp->m_resblks;
 548                 outval->resblks_avail = mp->m_resblks_avail;
 549                 return 0;
 550         }
 551
 552         request = *inval;
 553
 554         /*
 555          * With per-cpu counters, this becomes an interesting
 556          * problem. we needto work out if we are freeing or allocation
 557          * blocks first, then we can do the modification as necessary.
 558          *
 559          * We do this under the m_sb_lock so that if we are near
 560          * ENOSPC, we will hold out any changes while we work out
 561          * what to do. This means that the amount of free space can
 562          * change while we do this, so we need to retry if we end up
 563          * trying to reserve more space than is available.
 564          *
 565          * We also use the xfs_mod_incore_sb() interface so that we
 566          * don't have to care about whether per cpu counter are
 567          * enabled, disabled or even compiled in....
 568          */
 569 retry:
 570         spin_lock(&mp->m_sb_lock);
 571         xfs_icsb_sync_counters_locked(mp, 0);
 572
 573         /*
 574          * If our previous reservation was larger than the current value,
 575          * then move any unused blocks back to the free pool.
 576          */
 577         fdblks_delta = 0;
 578         if (mp->m_resblks > request) {
 579                 lcounter = mp->m_resblks_avail - request;
 580                 if (lcounter  > 0) {            /* release unused blocks */
 581                         fdblks_delta = lcounter;
 582                         mp->m_resblks_avail -= lcounter;
 583                 }
 584                 mp->m_resblks = request;
 585         } else {
 586                 __int64_t       free;
 587
 588                 free =  mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
 589                 if (!free)
 590                         goto out; /* ENOSPC and fdblks_delta = 0 */
 591
 592                 delta = request - mp->m_resblks;
 593                 lcounter = free - delta;
 594                 if (lcounter < 0) {
 595                         /* We can't satisfy the request, just get what we can */
 596                         mp->m_resblks += free;
 597                         mp->m_resblks_avail += free;
 598                         fdblks_delta = -free;
 599                 } else {
 600                         fdblks_delta = -delta;
 601                         mp->m_resblks = request;
 602                         mp->m_resblks_avail += delta;
 603                 }
 604         }
 605 out:
 606         if (outval) {
 607                 outval->resblks = mp->m_resblks;
 608                 outval->resblks_avail = mp->m_resblks_avail;
 609         }
 610         spin_unlock(&mp->m_sb_lock);
 611
 612         if (fdblks_delta) {
 613                 /*
 614                  * If we are putting blocks back here, m_resblks_avail is
 615                  * already at its max so this will put it in the free pool.
 616                  *
 617                  * If we need space, we'll either succeed in getting it
 618                  * from the free block count or we'll get an enospc. If
 619                  * we get a ENOSPC, it means things changed while we were
 620                  * calculating fdblks_delta and so we should try again to
 621                  * see if there is anything left to reserve.
 622                  *
 623                  * Don't set the reserved flag here - we don't want to reserve
 624                  * the extra reserve blocks from the reserve.....
 625                  */
 626                 int error;
 627                 error = xfs_icsb_modify_counters(mp, XFS_SBS_FDBLOCKS,
 628                                                  fdblks_delta, 0);
 629                 if (error == ENOSPC)
 630                         goto retry;
 631         }
 632         return 0;
 633 }
 634
 635 /*
 636  * Dump a transaction into the log that contains no real change. This is needed
 637  * to be able to make the log dirty or stamp the current tail LSN into the log
 638  * during the covering operation.
 639  *
 640  * We cannot use an inode here for this - that will push dirty state back up
 641  * into the VFS and then periodic inode flushing will prevent log covering from
 642  * making progress. Hence we log a field in the superblock instead and use a
 643  * synchronous transaction to ensure the superblock is immediately unpinned
 644  * and can be written back.
 645  */
 646 int
 647 xfs_fs_log_dummy(
 648         xfs_mount_t     *mp)
 649 {
 650         xfs_trans_t     *tp;
 651         int             error;
 652
 653         tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1, KM_SLEEP);
 654         error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
 655                                         XFS_DEFAULT_LOG_COUNT);
 656         if (error) {
 657                 xfs_trans_cancel(tp, 0);
 658                 return error;
 659         }
 660
 661         /* log the UUID because it is an unchanging field */
 662         xfs_mod_sb(tp, XFS_SB_UUID);
 663         xfs_trans_set_sync(tp);
 664         return xfs_trans_commit(tp, 0);
 665 }
 666
 667 int
 668 xfs_fs_goingdown(
 669         xfs_mount_t     *mp,
 670         __uint32_t      inflags)
 671 {
 672         switch (inflags) {
 673         case XFS_FSOP_GOING_FLAGS_DEFAULT: {
 674                 struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);
 675
 676                 if (sb && !IS_ERR(sb)) {
 677                         xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
 678                         thaw_bdev(sb->s_bdev, sb);
 679                 }
 680
 681                 break;
 682         }
 683         case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
 684                 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
 685                 break;
 686         case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
 687                 xfs_force_shutdown(mp,
 688                                 SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
 689                 break;
 690         default:
 691                 return XFS_ERROR(EINVAL);
 692         }
 693
 694         return 0;
 695 }