linux/fs/xfs/xfs_fsops.c
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   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_dir2.h"
  28#include "xfs_dmapi.h"
  29#include "xfs_mount.h"
  30#include "xfs_bmap_btree.h"
  31#include "xfs_alloc_btree.h"
  32#include "xfs_ialloc_btree.h"
  33#include "xfs_dir2_sf.h"
  34#include "xfs_attr_sf.h"
  35#include "xfs_dinode.h"
  36#include "xfs_inode.h"
  37#include "xfs_inode_item.h"
  38#include "xfs_btree.h"
  39#include "xfs_error.h"
  40#include "xfs_alloc.h"
  41#include "xfs_ialloc.h"
  42#include "xfs_fsops.h"
  43#include "xfs_itable.h"
  44#include "xfs_trans_space.h"
  45#include "xfs_rtalloc.h"
  46#include "xfs_rw.h"
  47#include "xfs_filestream.h"
  48
  49/*
  50 * File system operations
  51 */
  52
  53int
  54xfs_fs_geometry(
  55        xfs_mount_t             *mp,
  56        xfs_fsop_geom_t         *geo,
  57        int                     new_version)
  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_haslazysbcount(&mp->m_sb) ?
  99                                XFS_FSOP_GEOM_FLAGS_LAZYSB : 0) |
 100                        (xfs_sb_version_hasattr2(&mp->m_sb) ?
 101                                XFS_FSOP_GEOM_FLAGS_ATTR2 : 0);
 102                geo->logsectsize = xfs_sb_version_hassector(&mp->m_sb) ?
 103                                mp->m_sb.sb_logsectsize : BBSIZE;
 104                geo->rtsectsize = mp->m_sb.sb_blocksize;
 105                geo->dirblocksize = mp->m_dirblksize;
 106        }
 107        if (new_version >= 4) {
 108                geo->flags |=
 109                        (xfs_sb_version_haslogv2(&mp->m_sb) ?
 110                                XFS_FSOP_GEOM_FLAGS_LOGV2 : 0);
 111                geo->logsunit = mp->m_sb.sb_logsunit;
 112        }
 113        return 0;
 114}
 115
 116static int
 117xfs_growfs_data_private(
 118        xfs_mount_t             *mp,            /* mount point for filesystem */
 119        xfs_growfs_data_t       *in)            /* growfs data input struct */
 120{
 121        xfs_agf_t               *agf;
 122        xfs_agi_t               *agi;
 123        xfs_agnumber_t          agno;
 124        xfs_extlen_t            agsize;
 125        xfs_extlen_t            tmpsize;
 126        xfs_alloc_rec_t         *arec;
 127        xfs_btree_sblock_t      *block;
 128        xfs_buf_t               *bp;
 129        int                     bucket;
 130        int                     dpct;
 131        int                     error;
 132        xfs_agnumber_t          nagcount;
 133        xfs_agnumber_t          nagimax = 0;
 134        xfs_rfsblock_t          nb, nb_mod;
 135        xfs_rfsblock_t          new;
 136        xfs_rfsblock_t          nfree;
 137        xfs_agnumber_t          oagcount;
 138        int                     pct;
 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        if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
 146                return error;
 147        dpct = pct - mp->m_sb.sb_imax_pct;
 148        error = xfs_read_buf(mp, mp->m_ddev_targp,
 149                        XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
 150                        XFS_FSS_TO_BB(mp, 1), 0, &bp);
 151        if (error)
 152                return error;
 153        ASSERT(bp);
 154        xfs_buf_relse(bp);
 155
 156        new = nb;       /* use new as a temporary here */
 157        nb_mod = do_div(new, mp->m_sb.sb_agblocks);
 158        nagcount = new + (nb_mod != 0);
 159        if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
 160                nagcount--;
 161                nb = nagcount * mp->m_sb.sb_agblocks;
 162                if (nb < mp->m_sb.sb_dblocks)
 163                        return XFS_ERROR(EINVAL);
 164        }
 165        new = nb - mp->m_sb.sb_dblocks;
 166        oagcount = mp->m_sb.sb_agcount;
 167        if (nagcount > oagcount) {
 168                xfs_filestream_flush(mp);
 169                down_write(&mp->m_peraglock);
 170                mp->m_perag = kmem_realloc(mp->m_perag,
 171                        sizeof(xfs_perag_t) * nagcount,
 172                        sizeof(xfs_perag_t) * oagcount,
 173                        KM_SLEEP);
 174                memset(&mp->m_perag[oagcount], 0,
 175                        (nagcount - oagcount) * sizeof(xfs_perag_t));
 176                mp->m_flags |= XFS_MOUNT_32BITINODES;
 177                nagimax = xfs_initialize_perag(mp, nagcount);
 178                up_write(&mp->m_peraglock);
 179        }
 180        tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFS);
 181        tp->t_flags |= XFS_TRANS_RESERVE;
 182        if ((error = xfs_trans_reserve(tp, XFS_GROWFS_SPACE_RES(mp),
 183                        XFS_GROWDATA_LOG_RES(mp), 0, 0, 0))) {
 184                xfs_trans_cancel(tp, 0);
 185                return error;
 186        }
 187
 188        nfree = 0;
 189        for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) {
 190                /*
 191                 * AG freelist header block
 192                 */
 193                bp = xfs_buf_get(mp->m_ddev_targp,
 194                                  XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
 195                                  XFS_FSS_TO_BB(mp, 1), 0);
 196                agf = XFS_BUF_TO_AGF(bp);
 197                memset(agf, 0, mp->m_sb.sb_sectsize);
 198                agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
 199                agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
 200                agf->agf_seqno = cpu_to_be32(agno);
 201                if (agno == nagcount - 1)
 202                        agsize =
 203                                nb -
 204                                (agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
 205                else
 206                        agsize = mp->m_sb.sb_agblocks;
 207                agf->agf_length = cpu_to_be32(agsize);
 208                agf->agf_roots[XFS_BTNUM_BNOi] = cpu_to_be32(XFS_BNO_BLOCK(mp));
 209                agf->agf_roots[XFS_BTNUM_CNTi] = cpu_to_be32(XFS_CNT_BLOCK(mp));
 210                agf->agf_levels[XFS_BTNUM_BNOi] = cpu_to_be32(1);
 211                agf->agf_levels[XFS_BTNUM_CNTi] = cpu_to_be32(1);
 212                agf->agf_flfirst = 0;
 213                agf->agf_fllast = cpu_to_be32(XFS_AGFL_SIZE(mp) - 1);
 214                agf->agf_flcount = 0;
 215                tmpsize = agsize - XFS_PREALLOC_BLOCKS(mp);
 216                agf->agf_freeblks = cpu_to_be32(tmpsize);
 217                agf->agf_longest = cpu_to_be32(tmpsize);
 218                error = xfs_bwrite(mp, bp);
 219                if (error) {
 220                        goto error0;
 221                }
 222                /*
 223                 * AG inode header block
 224                 */
 225                bp = xfs_buf_get(mp->m_ddev_targp,
 226                                  XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
 227                                  XFS_FSS_TO_BB(mp, 1), 0);
 228                agi = XFS_BUF_TO_AGI(bp);
 229                memset(agi, 0, mp->m_sb.sb_sectsize);
 230                agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
 231                agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
 232                agi->agi_seqno = cpu_to_be32(agno);
 233                agi->agi_length = cpu_to_be32(agsize);
 234                agi->agi_count = 0;
 235                agi->agi_root = cpu_to_be32(XFS_IBT_BLOCK(mp));
 236                agi->agi_level = cpu_to_be32(1);
 237                agi->agi_freecount = 0;
 238                agi->agi_newino = cpu_to_be32(NULLAGINO);
 239                agi->agi_dirino = cpu_to_be32(NULLAGINO);
 240                for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
 241                        agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
 242                error = xfs_bwrite(mp, bp);
 243                if (error) {
 244                        goto error0;
 245                }
 246                /*
 247                 * BNO btree root block
 248                 */
 249                bp = xfs_buf_get(mp->m_ddev_targp,
 250                        XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
 251                        BTOBB(mp->m_sb.sb_blocksize), 0);
 252                block = XFS_BUF_TO_SBLOCK(bp);
 253                memset(block, 0, mp->m_sb.sb_blocksize);
 254                block->bb_magic = cpu_to_be32(XFS_ABTB_MAGIC);
 255                block->bb_level = 0;
 256                block->bb_numrecs = cpu_to_be16(1);
 257                block->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 258                block->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 259                arec = XFS_BTREE_REC_ADDR(xfs_alloc, block, 1);
 260                arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
 261                arec->ar_blockcount = cpu_to_be32(
 262                        agsize - be32_to_cpu(arec->ar_startblock));
 263                error = xfs_bwrite(mp, bp);
 264                if (error) {
 265                        goto error0;
 266                }
 267                /*
 268                 * CNT btree root block
 269                 */
 270                bp = xfs_buf_get(mp->m_ddev_targp,
 271                        XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
 272                        BTOBB(mp->m_sb.sb_blocksize), 0);
 273                block = XFS_BUF_TO_SBLOCK(bp);
 274                memset(block, 0, mp->m_sb.sb_blocksize);
 275                block->bb_magic = cpu_to_be32(XFS_ABTC_MAGIC);
 276                block->bb_level = 0;
 277                block->bb_numrecs = cpu_to_be16(1);
 278                block->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 279                block->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 280                arec = XFS_BTREE_REC_ADDR(xfs_alloc, block, 1);
 281                arec->ar_startblock = cpu_to_be32(XFS_PREALLOC_BLOCKS(mp));
 282                arec->ar_blockcount = cpu_to_be32(
 283                        agsize - be32_to_cpu(arec->ar_startblock));
 284                nfree += be32_to_cpu(arec->ar_blockcount);
 285                error = xfs_bwrite(mp, bp);
 286                if (error) {
 287                        goto error0;
 288                }
 289                /*
 290                 * INO btree root block
 291                 */
 292                bp = xfs_buf_get(mp->m_ddev_targp,
 293                        XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
 294                        BTOBB(mp->m_sb.sb_blocksize), 0);
 295                block = XFS_BUF_TO_SBLOCK(bp);
 296                memset(block, 0, mp->m_sb.sb_blocksize);
 297                block->bb_magic = cpu_to_be32(XFS_IBT_MAGIC);
 298                block->bb_level = 0;
 299                block->bb_numrecs = 0;
 300                block->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 301                block->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 302                error = xfs_bwrite(mp, bp);
 303                if (error) {
 304                        goto error0;
 305                }
 306        }
 307        xfs_trans_agblocks_delta(tp, nfree);
 308        /*
 309         * There are new blocks in the old last a.g.
 310         */
 311        if (new) {
 312                /*
 313                 * Change the agi length.
 314                 */
 315                error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
 316                if (error) {
 317                        goto error0;
 318                }
 319                ASSERT(bp);
 320                agi = XFS_BUF_TO_AGI(bp);
 321                be32_add_cpu(&agi->agi_length, new);
 322                ASSERT(nagcount == oagcount ||
 323                       be32_to_cpu(agi->agi_length) == mp->m_sb.sb_agblocks);
 324                xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
 325                /*
 326                 * Change agf length.
 327                 */
 328                error = xfs_alloc_read_agf(mp, tp, agno, 0, &bp);
 329                if (error) {
 330                        goto error0;
 331                }
 332                ASSERT(bp);
 333                agf = XFS_BUF_TO_AGF(bp);
 334                be32_add_cpu(&agf->agf_length, new);
 335                ASSERT(be32_to_cpu(agf->agf_length) ==
 336                       be32_to_cpu(agi->agi_length));
 337                xfs_alloc_log_agf(tp, bp, XFS_AGF_LENGTH);
 338                /*
 339                 * Free the new space.
 340                 */
 341                error = xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, agno,
 342                        be32_to_cpu(agf->agf_length) - new), new);
 343                if (error) {
 344                        goto error0;
 345                }
 346        }
 347        if (nagcount > oagcount)
 348                xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
 349        if (nb > mp->m_sb.sb_dblocks)
 350                xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
 351                                 nb - mp->m_sb.sb_dblocks);
 352        if (nfree)
 353                xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, nfree);
 354        if (dpct)
 355                xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
 356        error = xfs_trans_commit(tp, 0);
 357        if (error) {
 358                return error;
 359        }
 360        /* New allocation groups fully initialized, so update mount struct */
 361        if (nagimax)
 362                mp->m_maxagi = nagimax;
 363        if (mp->m_sb.sb_imax_pct) {
 364                __uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
 365                do_div(icount, 100);
 366                mp->m_maxicount = icount << mp->m_sb.sb_inopblog;
 367        } else
 368                mp->m_maxicount = 0;
 369        for (agno = 1; agno < nagcount; agno++) {
 370                error = xfs_read_buf(mp, mp->m_ddev_targp,
 371                                  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
 372                                  XFS_FSS_TO_BB(mp, 1), 0, &bp);
 373                if (error) {
 374                        xfs_fs_cmn_err(CE_WARN, mp,
 375                        "error %d reading secondary superblock for ag %d",
 376                                error, agno);
 377                        break;
 378                }
 379                xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, XFS_SB_ALL_BITS);
 380                /*
 381                 * If we get an error writing out the alternate superblocks,
 382                 * just issue a warning and continue.  The real work is
 383                 * already done and committed.
 384                 */
 385                if (!(error = xfs_bwrite(mp, bp))) {
 386                        continue;
 387                } else {
 388                        xfs_fs_cmn_err(CE_WARN, mp,
 389                "write error %d updating secondary superblock for ag %d",
 390                                error, agno);
 391                        break; /* no point in continuing */
 392                }
 393        }
 394        return 0;
 395
 396 error0:
 397        xfs_trans_cancel(tp, XFS_TRANS_ABORT);
 398        return error;
 399}
 400
 401static int
 402xfs_growfs_log_private(
 403        xfs_mount_t             *mp,    /* mount point for filesystem */
 404        xfs_growfs_log_t        *in)    /* growfs log input struct */
 405{
 406        xfs_extlen_t            nb;
 407
 408        nb = in->newblocks;
 409        if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
 410                return XFS_ERROR(EINVAL);
 411        if (nb == mp->m_sb.sb_logblocks &&
 412            in->isint == (mp->m_sb.sb_logstart != 0))
 413                return XFS_ERROR(EINVAL);
 414        /*
 415         * Moving the log is hard, need new interfaces to sync
 416         * the log first, hold off all activity while moving it.
 417         * Can have shorter or longer log in the same space,
 418         * or transform internal to external log or vice versa.
 419         */
 420        return XFS_ERROR(ENOSYS);
 421}
 422
 423/*
 424 * protected versions of growfs function acquire and release locks on the mount
 425 * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
 426 * XFS_IOC_FSGROWFSRT
 427 */
 428
 429
 430int
 431xfs_growfs_data(
 432        xfs_mount_t             *mp,
 433        xfs_growfs_data_t       *in)
 434{
 435        int error;
 436        if (!mutex_trylock(&mp->m_growlock))
 437                return XFS_ERROR(EWOULDBLOCK);
 438        error = xfs_growfs_data_private(mp, in);
 439        mutex_unlock(&mp->m_growlock);
 440        return error;
 441}
 442
 443int
 444xfs_growfs_log(
 445        xfs_mount_t             *mp,
 446        xfs_growfs_log_t        *in)
 447{
 448        int error;
 449        if (!mutex_trylock(&mp->m_growlock))
 450                return XFS_ERROR(EWOULDBLOCK);
 451        error = xfs_growfs_log_private(mp, in);
 452        mutex_unlock(&mp->m_growlock);
 453        return error;
 454}
 455
 456/*
 457 * exported through ioctl XFS_IOC_FSCOUNTS
 458 */
 459
 460int
 461xfs_fs_counts(
 462        xfs_mount_t             *mp,
 463        xfs_fsop_counts_t       *cnt)
 464{
 465        xfs_icsb_sync_counters_flags(mp, XFS_ICSB_LAZY_COUNT);
 466        spin_lock(&mp->m_sb_lock);
 467        cnt->freedata = mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
 468        cnt->freertx = mp->m_sb.sb_frextents;
 469        cnt->freeino = mp->m_sb.sb_ifree;
 470        cnt->allocino = mp->m_sb.sb_icount;
 471        spin_unlock(&mp->m_sb_lock);
 472        return 0;
 473}
 474
 475/*
 476 * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
 477 *
 478 * xfs_reserve_blocks is called to set m_resblks
 479 * in the in-core mount table. The number of unused reserved blocks
 480 * is kept in m_resblks_avail.
 481 *
 482 * Reserve the requested number of blocks if available. Otherwise return
 483 * as many as possible to satisfy the request. The actual number
 484 * reserved are returned in outval
 485 *
 486 * A null inval pointer indicates that only the current reserved blocks
 487 * available  should  be returned no settings are changed.
 488 */
 489
 490int
 491xfs_reserve_blocks(
 492        xfs_mount_t             *mp,
 493        __uint64_t              *inval,
 494        xfs_fsop_resblks_t      *outval)
 495{
 496        __int64_t               lcounter, delta, fdblks_delta;
 497        __uint64_t              request;
 498
 499        /* If inval is null, report current values and return */
 500        if (inval == (__uint64_t *)NULL) {
 501                if (!outval)
 502                        return EINVAL;
 503                outval->resblks = mp->m_resblks;
 504                outval->resblks_avail = mp->m_resblks_avail;
 505                return 0;
 506        }
 507
 508        request = *inval;
 509
 510        /*
 511         * With per-cpu counters, this becomes an interesting
 512         * problem. we needto work out if we are freeing or allocation
 513         * blocks first, then we can do the modification as necessary.
 514         *
 515         * We do this under the m_sb_lock so that if we are near
 516         * ENOSPC, we will hold out any changes while we work out
 517         * what to do. This means that the amount of free space can
 518         * change while we do this, so we need to retry if we end up
 519         * trying to reserve more space than is available.
 520         *
 521         * We also use the xfs_mod_incore_sb() interface so that we
 522         * don't have to care about whether per cpu counter are
 523         * enabled, disabled or even compiled in....
 524         */
 525retry:
 526        spin_lock(&mp->m_sb_lock);
 527        xfs_icsb_sync_counters_flags(mp, XFS_ICSB_SB_LOCKED);
 528
 529        /*
 530         * If our previous reservation was larger than the current value,
 531         * then move any unused blocks back to the free pool.
 532         */
 533        fdblks_delta = 0;
 534        if (mp->m_resblks > request) {
 535                lcounter = mp->m_resblks_avail - request;
 536                if (lcounter  > 0) {            /* release unused blocks */
 537                        fdblks_delta = lcounter;
 538                        mp->m_resblks_avail -= lcounter;
 539                }
 540                mp->m_resblks = request;
 541        } else {
 542                __int64_t       free;
 543
 544                free =  mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
 545                if (!free)
 546                        goto out; /* ENOSPC and fdblks_delta = 0 */
 547
 548                delta = request - mp->m_resblks;
 549                lcounter = free - delta;
 550                if (lcounter < 0) {
 551                        /* We can't satisfy the request, just get what we can */
 552                        mp->m_resblks += free;
 553                        mp->m_resblks_avail += free;
 554                        fdblks_delta = -free;
 555                        mp->m_sb.sb_fdblocks = XFS_ALLOC_SET_ASIDE(mp);
 556                } else {
 557                        fdblks_delta = -delta;
 558                        mp->m_sb.sb_fdblocks =
 559                                lcounter + XFS_ALLOC_SET_ASIDE(mp);
 560                        mp->m_resblks = request;
 561                        mp->m_resblks_avail += delta;
 562                }
 563        }
 564out:
 565        if (outval) {
 566                outval->resblks = mp->m_resblks;
 567                outval->resblks_avail = mp->m_resblks_avail;
 568        }
 569        spin_unlock(&mp->m_sb_lock);
 570
 571        if (fdblks_delta) {
 572                /*
 573                 * If we are putting blocks back here, m_resblks_avail is
 574                 * already at it's max so this will put it in the free pool.
 575                 *
 576                 * If we need space, we'll either succeed in getting it
 577                 * from the free block count or we'll get an enospc. If
 578                 * we get a ENOSPC, it means things changed while we were
 579                 * calculating fdblks_delta and so we should try again to
 580                 * see if there is anything left to reserve.
 581                 *
 582                 * Don't set the reserved flag here - we don't want to reserve
 583                 * the extra reserve blocks from the reserve.....
 584                 */
 585                int error;
 586                error = xfs_mod_incore_sb(mp, XFS_SBS_FDBLOCKS, fdblks_delta, 0);
 587                if (error == ENOSPC)
 588                        goto retry;
 589        }
 590
 591        return 0;
 592}
 593
 594void
 595xfs_fs_log_dummy(
 596        xfs_mount_t     *mp)
 597{
 598        xfs_trans_t     *tp;
 599        xfs_inode_t     *ip;
 600
 601        tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);
 602        if (xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0)) {
 603                xfs_trans_cancel(tp, 0);
 604                return;
 605        }
 606
 607        ip = mp->m_rootip;
 608        xfs_ilock(ip, XFS_ILOCK_EXCL);
 609
 610        xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 611        xfs_trans_ihold(tp, ip);
 612        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 613        xfs_trans_set_sync(tp);
 614        xfs_trans_commit(tp, 0);
 615
 616        xfs_iunlock(ip, XFS_ILOCK_EXCL);
 617}
 618
 619int
 620xfs_fs_goingdown(
 621        xfs_mount_t     *mp,
 622        __uint32_t      inflags)
 623{
 624        switch (inflags) {
 625        case XFS_FSOP_GOING_FLAGS_DEFAULT: {
 626                struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);
 627
 628                if (sb && !IS_ERR(sb)) {
 629                        xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
 630                        thaw_bdev(sb->s_bdev, sb);
 631                }
 632        
 633                break;
 634        }
 635        case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
 636                xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
 637                break;
 638        case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
 639                xfs_force_shutdown(mp,
 640                                SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
 641                break;
 642        default:
 643                return XFS_ERROR(EINVAL);
 644        }
 645
 646        return 0;
 647}
 648
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