fs/xfs/quota/xfs_dquot.c

   1 /*
   2  * Copyright (c) 2000-2003 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_bit.h"
  21 #include "xfs_log.h"
  22 #include "xfs_inum.h"
  23 #include "xfs_trans.h"
  24 #include "xfs_sb.h"
  25 #include "xfs_ag.h"
  26 #include "xfs_alloc.h"
  27 #include "xfs_quota.h"
  28 #include "xfs_mount.h"
  29 #include "xfs_bmap_btree.h"
  30 #include "xfs_inode.h"
  31 #include "xfs_bmap.h"
  32 #include "xfs_rtalloc.h"
  33 #include "xfs_error.h"
  34 #include "xfs_itable.h"
  35 #include "xfs_attr.h"
  36 #include "xfs_buf_item.h"
  37 #include "xfs_trans_space.h"
  38 #include "xfs_trans_priv.h"
  39 #include "xfs_qm.h"
  40 #include "xfs_trace.h"
  41
  42
  43 /*
  44    LOCK ORDER
  45
  46    inode lock               (ilock)
  47    dquot hash-chain lock    (hashlock)
  48    xqm dquot freelist lock  (freelistlock
  49    mount's dquot list lock  (mplistlock)
  50    user dquot lock - lock ordering among dquots is based on the uid or gid
  51    group dquot lock - similar to udquots. Between the two dquots, the udquot
  52                       has to be locked first.
  53    pin lock - the dquot lock must be held to take this lock.
  54    flush lock - ditto.
  55 */
  56
  57 #ifdef DEBUG
  58 xfs_buftarg_t *xfs_dqerror_target;
  59 int xfs_do_dqerror;
  60 int xfs_dqreq_num;
  61 int xfs_dqerror_mod = 33;
  62 #endif
  63
  64 static struct lock_class_key xfs_dquot_other_class;
  65
  66 /*
  67  * Allocate and initialize a dquot. We don't always allocate fresh memory;
  68  * we try to reclaim a free dquot if the number of incore dquots are above
  69  * a threshold.
  70  * The only field inside the core that gets initialized at this point
  71  * is the d_id field. The idea is to fill in the entire q_core
  72  * when we read in the on disk dquot.
  73  */
  74 STATIC xfs_dquot_t *
  75 xfs_qm_dqinit(
  76         xfs_mount_t  *mp,
  77         xfs_dqid_t   id,
  78         uint         type)
  79 {
  80         xfs_dquot_t     *dqp;
  81         boolean_t       brandnewdquot;
  82
  83         brandnewdquot = xfs_qm_dqalloc_incore(&dqp);
  84         dqp->dq_flags = type;
  85         dqp->q_core.d_id = cpu_to_be32(id);
  86         dqp->q_mount = mp;
  87
  88         /*
  89          * No need to re-initialize these if this is a reclaimed dquot.
  90          */
  91         if (brandnewdquot) {
  92                 INIT_LIST_HEAD(&dqp->q_freelist);
  93                 mutex_init(&dqp->q_qlock);
  94                 init_waitqueue_head(&dqp->q_pinwait);
  95
  96                 /*
  97                  * Because we want to use a counting completion, complete
  98                  * the flush completion once to allow a single access to
  99                  * the flush completion without blocking.
 100                  */
 101                 init_completion(&dqp->q_flush);
 102                 complete(&dqp->q_flush);
 103
 104                 trace_xfs_dqinit(dqp);
 105         } else {
 106                 /*
 107                  * Only the q_core portion was zeroed in dqreclaim_one().
 108                  * So, we need to reset others.
 109                  */
 110                 dqp->q_nrefs = 0;
 111                 dqp->q_blkno = 0;
 112                 INIT_LIST_HEAD(&dqp->q_mplist);
 113                 INIT_LIST_HEAD(&dqp->q_hashlist);
 114                 dqp->q_bufoffset = 0;
 115                 dqp->q_fileoffset = 0;
 116                 dqp->q_transp = NULL;
 117                 dqp->q_gdquot = NULL;
 118                 dqp->q_res_bcount = 0;
 119                 dqp->q_res_icount = 0;
 120                 dqp->q_res_rtbcount = 0;
 121                 atomic_set(&dqp->q_pincount, 0);
 122                 dqp->q_hash = NULL;
 123                 ASSERT(list_empty(&dqp->q_freelist));
 124
 125                 trace_xfs_dqreuse(dqp);
 126         }
 127
 128         /*
 129          * In either case we need to make sure group quotas have a different
 130          * lock class than user quotas, to make sure lockdep knows we can
 131          * locks of one of each at the same time.
 132          */
 133         if (!(type & XFS_DQ_USER))
 134                 lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
 135
 136         /*
 137          * log item gets initialized later
 138          */
 139         return (dqp);
 140 }
 141
 142 /*
 143  * This is called to free all the memory associated with a dquot
 144  */
 145 void
 146 xfs_qm_dqdestroy(
 147         xfs_dquot_t     *dqp)
 148 {
 149         ASSERT(list_empty(&dqp->q_freelist));
 150
 151         mutex_destroy(&dqp->q_qlock);
 152         sv_destroy(&dqp->q_pinwait);
 153         kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
 154
 155         atomic_dec(&xfs_Gqm->qm_totaldquots);
 156 }
 157
 158 /*
 159  * This is what a 'fresh' dquot inside a dquot chunk looks like on disk.
 160  */
 161 STATIC void
 162 xfs_qm_dqinit_core(
 163         xfs_dqid_t      id,
 164         uint            type,
 165         xfs_dqblk_t     *d)
 166 {
 167         /*
 168          * Caller has zero'd the entire dquot 'chunk' already.
 169          */
 170         d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 171         d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 172         d->dd_diskdq.d_id = cpu_to_be32(id);
 173         d->dd_diskdq.d_flags = type;
 174 }
 175
 176 /*
 177  * If default limits are in force, push them into the dquot now.
 178  * We overwrite the dquot limits only if they are zero and this
 179  * is not the root dquot.
 180  */
 181 void
 182 xfs_qm_adjust_dqlimits(
 183         xfs_mount_t             *mp,
 184         xfs_disk_dquot_t        *d)
 185 {
 186         xfs_quotainfo_t         *q = mp->m_quotainfo;
 187
 188         ASSERT(d->d_id);
 189
 190         if (q->qi_bsoftlimit && !d->d_blk_softlimit)
 191                 d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
 192         if (q->qi_bhardlimit && !d->d_blk_hardlimit)
 193                 d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
 194         if (q->qi_isoftlimit && !d->d_ino_softlimit)
 195                 d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
 196         if (q->qi_ihardlimit && !d->d_ino_hardlimit)
 197                 d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
 198         if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
 199                 d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
 200         if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
 201                 d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
 202 }
 203
 204 /*
 205  * Check the limits and timers of a dquot and start or reset timers
 206  * if necessary.
 207  * This gets called even when quota enforcement is OFF, which makes our
 208  * life a little less complicated. (We just don't reject any quota
 209  * reservations in that case, when enforcement is off).
 210  * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
 211  * enforcement's off.
 212  * In contrast, warnings are a little different in that they don't
 213  * 'automatically' get started when limits get exceeded.  They do
 214  * get reset to zero, however, when we find the count to be under
 215  * the soft limit (they are only ever set non-zero via userspace).
 216  */
 217 void
 218 xfs_qm_adjust_dqtimers(
 219         xfs_mount_t             *mp,
 220         xfs_disk_dquot_t        *d)
 221 {
 222         ASSERT(d->d_id);
 223
 224 #ifdef QUOTADEBUG
 225         if (d->d_blk_hardlimit)
 226                 ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
 227                        be64_to_cpu(d->d_blk_hardlimit));
 228         if (d->d_ino_hardlimit)
 229                 ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
 230                        be64_to_cpu(d->d_ino_hardlimit));
 231         if (d->d_rtb_hardlimit)
 232                 ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
 233                        be64_to_cpu(d->d_rtb_hardlimit));
 234 #endif
 235         if (!d->d_btimer) {
 236                 if ((d->d_blk_softlimit &&
 237                      (be64_to_cpu(d->d_bcount) >=
 238                       be64_to_cpu(d->d_blk_softlimit))) ||
 239                     (d->d_blk_hardlimit &&
 240                      (be64_to_cpu(d->d_bcount) >=
 241                       be64_to_cpu(d->d_blk_hardlimit)))) {
 242                         d->d_btimer = cpu_to_be32(get_seconds() +
 243                                         mp->m_quotainfo->qi_btimelimit);
 244                 } else {
 245                         d->d_bwarns = 0;
 246                 }
 247         } else {
 248                 if ((!d->d_blk_softlimit ||
 249                      (be64_to_cpu(d->d_bcount) <
 250                       be64_to_cpu(d->d_blk_softlimit))) &&
 251                     (!d->d_blk_hardlimit ||
 252                     (be64_to_cpu(d->d_bcount) <
 253                      be64_to_cpu(d->d_blk_hardlimit)))) {
 254                         d->d_btimer = 0;
 255                 }
 256         }
 257
 258         if (!d->d_itimer) {
 259                 if ((d->d_ino_softlimit &&
 260                      (be64_to_cpu(d->d_icount) >=
 261                       be64_to_cpu(d->d_ino_softlimit))) ||
 262                     (d->d_ino_hardlimit &&
 263                      (be64_to_cpu(d->d_icount) >=
 264                       be64_to_cpu(d->d_ino_hardlimit)))) {
 265                         d->d_itimer = cpu_to_be32(get_seconds() +
 266                                         mp->m_quotainfo->qi_itimelimit);
 267                 } else {
 268                         d->d_iwarns = 0;
 269                 }
 270         } else {
 271                 if ((!d->d_ino_softlimit ||
 272                      (be64_to_cpu(d->d_icount) <
 273                       be64_to_cpu(d->d_ino_softlimit)))  &&
 274                     (!d->d_ino_hardlimit ||
 275                      (be64_to_cpu(d->d_icount) <
 276                       be64_to_cpu(d->d_ino_hardlimit)))) {
 277                         d->d_itimer = 0;
 278                 }
 279         }
 280
 281         if (!d->d_rtbtimer) {
 282                 if ((d->d_rtb_softlimit &&
 283                      (be64_to_cpu(d->d_rtbcount) >=
 284                       be64_to_cpu(d->d_rtb_softlimit))) ||
 285                     (d->d_rtb_hardlimit &&
 286                      (be64_to_cpu(d->d_rtbcount) >=
 287                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 288                         d->d_rtbtimer = cpu_to_be32(get_seconds() +
 289                                         mp->m_quotainfo->qi_rtbtimelimit);
 290                 } else {
 291                         d->d_rtbwarns = 0;
 292                 }
 293         } else {
 294                 if ((!d->d_rtb_softlimit ||
 295                      (be64_to_cpu(d->d_rtbcount) <
 296                       be64_to_cpu(d->d_rtb_softlimit))) &&
 297                     (!d->d_rtb_hardlimit ||
 298                      (be64_to_cpu(d->d_rtbcount) <
 299                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 300                         d->d_rtbtimer = 0;
 301                 }
 302         }
 303 }
 304
 305 /*
 306  * initialize a buffer full of dquots and log the whole thing
 307  */
 308 STATIC void
 309 xfs_qm_init_dquot_blk(
 310         xfs_trans_t     *tp,
 311         xfs_mount_t     *mp,
 312         xfs_dqid_t      id,
 313         uint            type,
 314         xfs_buf_t       *bp)
 315 {
 316         struct xfs_quotainfo    *q = mp->m_quotainfo;
 317         xfs_dqblk_t     *d;
 318         int             curid, i;
 319
 320         ASSERT(tp);
 321         ASSERT(XFS_BUF_ISBUSY(bp));
 322         ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 323
 324         d = (xfs_dqblk_t *)XFS_BUF_PTR(bp);
 325
 326         /*
 327          * ID of the first dquot in the block - id's are zero based.
 328          */
 329         curid = id - (id % q->qi_dqperchunk);
 330         ASSERT(curid >= 0);
 331         memset(d, 0, BBTOB(q->qi_dqchunklen));
 332         for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++)
 333                 xfs_qm_dqinit_core(curid, type, d);
 334         xfs_trans_dquot_buf(tp, bp,
 335                             (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
 336                             ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
 337                              XFS_BLF_GDQUOT_BUF)));
 338         xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
 339 }
 340
 341
 342
 343 /*
 344  * Allocate a block and fill it with dquots.
 345  * This is called when the bmapi finds a hole.
 346  */
 347 STATIC int
 348 xfs_qm_dqalloc(
 349         xfs_trans_t     **tpp,
 350         xfs_mount_t     *mp,
 351         xfs_dquot_t     *dqp,
 352         xfs_inode_t     *quotip,
 353         xfs_fileoff_t   offset_fsb,
 354         xfs_buf_t       **O_bpp)
 355 {
 356         xfs_fsblock_t   firstblock;
 357         xfs_bmap_free_t flist;
 358         xfs_bmbt_irec_t map;
 359         int             nmaps, error, committed;
 360         xfs_buf_t       *bp;
 361         xfs_trans_t     *tp = *tpp;
 362
 363         ASSERT(tp != NULL);
 364
 365         trace_xfs_dqalloc(dqp);
 366
 367         /*
 368          * Initialize the bmap freelist prior to calling bmapi code.
 369          */
 370         xfs_bmap_init(&flist, &firstblock);
 371         xfs_ilock(quotip, XFS_ILOCK_EXCL);
 372         /*
 373          * Return if this type of quotas is turned off while we didn't
 374          * have an inode lock
 375          */
 376         if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
 377                 xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 378                 return (ESRCH);
 379         }
 380
 381         xfs_trans_ijoin_ref(tp, quotip, XFS_ILOCK_EXCL);
 382         nmaps = 1;
 383         if ((error = xfs_bmapi(tp, quotip,
 384                               offset_fsb, XFS_DQUOT_CLUSTER_SIZE_FSB,
 385                               XFS_BMAPI_METADATA | XFS_BMAPI_WRITE,
 386                               &firstblock,
 387                               XFS_QM_DQALLOC_SPACE_RES(mp),
 388                               &map, &nmaps, &flist))) {
 389                 goto error0;
 390         }
 391         ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
 392         ASSERT(nmaps == 1);
 393         ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 394                (map.br_startblock != HOLESTARTBLOCK));
 395
 396         /*
 397          * Keep track of the blkno to save a lookup later
 398          */
 399         dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 400
 401         /* now we can just get the buffer (there's nothing to read yet) */
 402         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
 403                                dqp->q_blkno,
 404                                mp->m_quotainfo->qi_dqchunklen,
 405                                0);
 406         if (!bp || (error = XFS_BUF_GETERROR(bp)))
 407                 goto error1;
 408         /*
 409          * Make a chunk of dquots out of this buffer and log
 410          * the entire thing.
 411          */
 412         xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
 413                               dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
 414
 415         /*
 416          * xfs_bmap_finish() may commit the current transaction and
 417          * start a second transaction if the freelist is not empty.
 418          *
 419          * Since we still want to modify this buffer, we need to
 420          * ensure that the buffer is not released on commit of
 421          * the first transaction and ensure the buffer is added to the
 422          * second transaction.
 423          *
 424          * If there is only one transaction then don't stop the buffer
 425          * from being released when it commits later on.
 426          */
 427
 428         xfs_trans_bhold(tp, bp);
 429
 430         if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
 431                 goto error1;
 432         }
 433
 434         if (committed) {
 435                 tp = *tpp;
 436                 xfs_trans_bjoin(tp, bp);
 437         } else {
 438                 xfs_trans_bhold_release(tp, bp);
 439         }
 440
 441         *O_bpp = bp;
 442         return 0;
 443
 444       error1:
 445         xfs_bmap_cancel(&flist);
 446       error0:
 447         xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 448
 449         return (error);
 450 }
 451
 452 /*
 453  * Maps a dquot to the buffer containing its on-disk version.
 454  * This returns a ptr to the buffer containing the on-disk dquot
 455  * in the bpp param, and a ptr to the on-disk dquot within that buffer
 456  */
 457 STATIC int
 458 xfs_qm_dqtobp(
 459         xfs_trans_t             **tpp,
 460         xfs_dquot_t             *dqp,
 461         xfs_disk_dquot_t        **O_ddpp,
 462         xfs_buf_t               **O_bpp,
 463         uint                    flags)
 464 {
 465         xfs_bmbt_irec_t map;
 466         int             nmaps = 1, error;
 467         xfs_buf_t       *bp;
 468         xfs_inode_t     *quotip = XFS_DQ_TO_QIP(dqp);
 469         xfs_mount_t     *mp = dqp->q_mount;
 470         xfs_disk_dquot_t *ddq;
 471         xfs_dqid_t      id = be32_to_cpu(dqp->q_core.d_id);
 472         xfs_trans_t     *tp = (tpp ? *tpp : NULL);
 473
 474         dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
 475
 476         xfs_ilock(quotip, XFS_ILOCK_SHARED);
 477         if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
 478                 /*
 479                  * Return if this type of quotas is turned off while we
 480                  * didn't have the quota inode lock.
 481                  */
 482                 xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 483                 return ESRCH;
 484         }
 485
 486         /*
 487          * Find the block map; no allocations yet
 488          */
 489         error = xfs_bmapi(NULL, quotip, dqp->q_fileoffset,
 490                           XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
 491                           NULL, 0, &map, &nmaps, NULL);
 492
 493         xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 494         if (error)
 495                 return error;
 496
 497         ASSERT(nmaps == 1);
 498         ASSERT(map.br_blockcount == 1);
 499
 500         /*
 501          * Offset of dquot in the (fixed sized) dquot chunk.
 502          */
 503         dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
 504                 sizeof(xfs_dqblk_t);
 505
 506         ASSERT(map.br_startblock != DELAYSTARTBLOCK);
 507         if (map.br_startblock == HOLESTARTBLOCK) {
 508                 /*
 509                  * We don't allocate unless we're asked to
 510                  */
 511                 if (!(flags & XFS_QMOPT_DQALLOC))
 512                         return ENOENT;
 513
 514                 ASSERT(tp);
 515                 error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
 516                                         dqp->q_fileoffset, &bp);
 517                 if (error)
 518                         return error;
 519                 tp = *tpp;
 520         } else {
 521                 trace_xfs_dqtobp_read(dqp);
 522
 523                 /*
 524                  * store the blkno etc so that we don't have to do the
 525                  * mapping all the time
 526                  */
 527                 dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 528
 529                 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 530                                            dqp->q_blkno,
 531                                            mp->m_quotainfo->qi_dqchunklen,
 532                                            0, &bp);
 533                 if (error || !bp)
 534                         return XFS_ERROR(error);
 535         }
 536
 537         ASSERT(XFS_BUF_ISBUSY(bp));
 538         ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 539
 540         /*
 541          * calculate the location of the dquot inside the buffer.
 542          */
 543         ddq = (struct xfs_disk_dquot *)(XFS_BUF_PTR(bp) + dqp->q_bufoffset);
 544
 545         /*
 546          * A simple sanity check in case we got a corrupted dquot...
 547          */
 548         if (xfs_qm_dqcheck(ddq, id, dqp->dq_flags & XFS_DQ_ALLTYPES,
 549                            flags & (XFS_QMOPT_DQREPAIR|XFS_QMOPT_DOWARN),
 550                            "dqtobp")) {
 551                 if (!(flags & XFS_QMOPT_DQREPAIR)) {
 552                         xfs_trans_brelse(tp, bp);
 553                         return XFS_ERROR(EIO);
 554                 }
 555                 XFS_BUF_BUSY(bp); /* We dirtied this */
 556         }
 557
 558         *O_bpp = bp;
 559         *O_ddpp = ddq;
 560
 561         return (0);
 562 }
 563
 564
 565 /*
 566  * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
 567  * and release the buffer immediately.
 568  *
 569  */
 570 /* ARGSUSED */
 571 STATIC int
 572 xfs_qm_dqread(
 573         xfs_trans_t     **tpp,
 574         xfs_dqid_t      id,
 575         xfs_dquot_t     *dqp,   /* dquot to get filled in */
 576         uint            flags)
 577 {
 578         xfs_disk_dquot_t *ddqp;
 579         xfs_buf_t        *bp;
 580         int              error;
 581         xfs_trans_t      *tp;
 582
 583         ASSERT(tpp);
 584
 585         trace_xfs_dqread(dqp);
 586
 587         /*
 588          * get a pointer to the on-disk dquot and the buffer containing it
 589          * dqp already knows its own type (GROUP/USER).
 590          */
 591         if ((error = xfs_qm_dqtobp(tpp, dqp, &ddqp, &bp, flags))) {
 592                 return (error);
 593         }
 594         tp = *tpp;
 595
 596         /* copy everything from disk dquot to the incore dquot */
 597         memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
 598         ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);
 599         xfs_qm_dquot_logitem_init(dqp);
 600
 601         /*
 602          * Reservation counters are defined as reservation plus current usage
 603          * to avoid having to add everytime.
 604          */
 605         dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
 606         dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
 607         dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
 608
 609         /* Mark the buf so that this will stay incore a little longer */
 610         XFS_BUF_SET_VTYPE_REF(bp, B_FS_DQUOT, XFS_DQUOT_REF);
 611
 612         /*
 613          * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
 614          * So we need to release with xfs_trans_brelse().
 615          * The strategy here is identical to that of inodes; we lock
 616          * the dquot in xfs_qm_dqget() before making it accessible to
 617          * others. This is because dquots, like inodes, need a good level of
 618          * concurrency, and we don't want to take locks on the entire buffers
 619          * for dquot accesses.
 620          * Note also that the dquot buffer may even be dirty at this point, if
 621          * this particular dquot was repaired. We still aren't afraid to
 622          * brelse it because we have the changes incore.
 623          */
 624         ASSERT(XFS_BUF_ISBUSY(bp));
 625         ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 626         xfs_trans_brelse(tp, bp);
 627
 628         return (error);
 629 }
 630
 631
 632 /*
 633  * allocate an incore dquot from the kernel heap,
 634  * and fill its core with quota information kept on disk.
 635  * If XFS_QMOPT_DQALLOC is set, it'll allocate a dquot on disk
 636  * if it wasn't already allocated.
 637  */
 638 STATIC int
 639 xfs_qm_idtodq(
 640         xfs_mount_t     *mp,
 641         xfs_dqid_t      id,      /* gid or uid, depending on type */
 642         uint            type,    /* UDQUOT or GDQUOT */
 643         uint            flags,   /* DQALLOC, DQREPAIR */
 644         xfs_dquot_t     **O_dqpp)/* OUT : incore dquot, not locked */
 645 {
 646         xfs_dquot_t     *dqp;
 647         int             error;
 648         xfs_trans_t     *tp;
 649         int             cancelflags=0;
 650
 651         dqp = xfs_qm_dqinit(mp, id, type);
 652         tp = NULL;
 653         if (flags & XFS_QMOPT_DQALLOC) {
 654                 tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
 655                 error = xfs_trans_reserve(tp, XFS_QM_DQALLOC_SPACE_RES(mp),
 656                                 XFS_WRITE_LOG_RES(mp) +
 657                                 BBTOB(mp->m_quotainfo->qi_dqchunklen) - 1 +
 658                                 128,
 659                                 0,
 660                                 XFS_TRANS_PERM_LOG_RES,
 661                                 XFS_WRITE_LOG_COUNT);
 662                 if (error) {
 663                         cancelflags = 0;
 664                         goto error0;
 665                 }
 666                 cancelflags = XFS_TRANS_RELEASE_LOG_RES;
 667         }
 668
 669         /*
 670          * Read it from disk; xfs_dqread() takes care of
 671          * all the necessary initialization of dquot's fields (locks, etc)
 672          */
 673         if ((error = xfs_qm_dqread(&tp, id, dqp, flags))) {
 674                 /*
 675                  * This can happen if quotas got turned off (ESRCH),
 676                  * or if the dquot didn't exist on disk and we ask to
 677                  * allocate (ENOENT).
 678                  */
 679                 trace_xfs_dqread_fail(dqp);
 680                 cancelflags |= XFS_TRANS_ABORT;
 681                 goto error0;
 682         }
 683         if (tp) {
 684                 if ((error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES)))
 685                         goto error1;
 686         }
 687
 688         *O_dqpp = dqp;
 689         return (0);
 690
 691  error0:
 692         ASSERT(error);
 693         if (tp)
 694                 xfs_trans_cancel(tp, cancelflags);
 695  error1:
 696         xfs_qm_dqdestroy(dqp);
 697         *O_dqpp = NULL;
 698         return (error);
 699 }
 700
 701 /*
 702  * Lookup a dquot in the incore dquot hashtable. We keep two separate
 703  * hashtables for user and group dquots; and, these are global tables
 704  * inside the XQM, not per-filesystem tables.
 705  * The hash chain must be locked by caller, and it is left locked
 706  * on return. Returning dquot is locked.
 707  */
 708 STATIC int
 709 xfs_qm_dqlookup(
 710         xfs_mount_t             *mp,
 711         xfs_dqid_t              id,
 712         xfs_dqhash_t            *qh,
 713         xfs_dquot_t             **O_dqpp)
 714 {
 715         xfs_dquot_t             *dqp;
 716         uint                    flist_locked;
 717
 718         ASSERT(mutex_is_locked(&qh->qh_lock));
 719
 720         flist_locked = B_FALSE;
 721
 722         /*
 723          * Traverse the hashchain looking for a match
 724          */
 725         list_for_each_entry(dqp, &qh->qh_list, q_hashlist) {
 726                 /*
 727                  * We already have the hashlock. We don't need the
 728                  * dqlock to look at the id field of the dquot, since the
 729                  * id can't be modified without the hashlock anyway.
 730                  */
 731                 if (be32_to_cpu(dqp->q_core.d_id) == id && dqp->q_mount == mp) {
 732                         trace_xfs_dqlookup_found(dqp);
 733
 734                         /*
 735                          * All in core dquots must be on the dqlist of mp
 736                          */
 737                         ASSERT(!list_empty(&dqp->q_mplist));
 738
 739                         xfs_dqlock(dqp);
 740                         if (dqp->q_nrefs == 0) {
 741                                 ASSERT(!list_empty(&dqp->q_freelist));
 742                                 if (!mutex_trylock(&xfs_Gqm->qm_dqfrlist_lock)) {
 743                                         trace_xfs_dqlookup_want(dqp);
 744
 745                                         /*
 746                                          * We may have raced with dqreclaim_one()
 747                                          * (and lost). So, flag that we don't
 748                                          * want the dquot to be reclaimed.
 749                                          */
 750                                         dqp->dq_flags |= XFS_DQ_WANT;
 751                                         xfs_dqunlock(dqp);
 752                                         mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
 753                                         xfs_dqlock(dqp);
 754                                         dqp->dq_flags &= ~(XFS_DQ_WANT);
 755                                 }
 756                                 flist_locked = B_TRUE;
 757                         }
 758
 759                         /*
 760                          * id couldn't have changed; we had the hashlock all
 761                          * along
 762                          */
 763                         ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);
 764
 765                         if (flist_locked) {
 766                                 if (dqp->q_nrefs != 0) {
 767                                         mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
 768                                         flist_locked = B_FALSE;
 769                                 } else {
 770                                         /* take it off the freelist */
 771                                         trace_xfs_dqlookup_freelist(dqp);
 772                                         list_del_init(&dqp->q_freelist);
 773                                         xfs_Gqm->qm_dqfrlist_cnt--;
 774                                 }
 775                         }
 776
 777                         XFS_DQHOLD(dqp);
 778
 779                         if (flist_locked)
 780                                 mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
 781                         /*
 782                          * move the dquot to the front of the hashchain
 783                          */
 784                         ASSERT(mutex_is_locked(&qh->qh_lock));
 785                         list_move(&dqp->q_hashlist, &qh->qh_list);
 786                         trace_xfs_dqlookup_done(dqp);
 787                         *O_dqpp = dqp;
 788                         return 0;
 789                 }
 790         }
 791
 792         *O_dqpp = NULL;
 793         ASSERT(mutex_is_locked(&qh->qh_lock));
 794         return (1);
 795 }
 796
 797 /*
 798  * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
 799  * a locked dquot, doing an allocation (if requested) as needed.
 800  * When both an inode and an id are given, the inode's id takes precedence.
 801  * That is, if the id changes while we don't hold the ilock inside this
 802  * function, the new dquot is returned, not necessarily the one requested
 803  * in the id argument.
 804  */
 805 int
 806 xfs_qm_dqget(
 807         xfs_mount_t     *mp,
 808         xfs_inode_t     *ip,      /* locked inode (optional) */
 809         xfs_dqid_t      id,       /* uid/projid/gid depending on type */
 810         uint            type,     /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
 811         uint            flags,    /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
 812         xfs_dquot_t     **O_dqpp) /* OUT : locked incore dquot */
 813 {
 814         xfs_dquot_t     *dqp;
 815         xfs_dqhash_t    *h;
 816         uint            version;
 817         int             error;
 818
 819         ASSERT(XFS_IS_QUOTA_RUNNING(mp));
 820         if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
 821             (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
 822             (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
 823                 return (ESRCH);
 824         }
 825         h = XFS_DQ_HASH(mp, id, type);
 826
 827 #ifdef DEBUG
 828         if (xfs_do_dqerror) {
 829                 if ((xfs_dqerror_target == mp->m_ddev_targp) &&
 830                     (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
 831                         cmn_err(CE_DEBUG, "Returning error in dqget");
 832                         return (EIO);
 833                 }
 834         }
 835 #endif
 836
 837  again:
 838
 839 #ifdef DEBUG
 840         ASSERT(type == XFS_DQ_USER ||
 841                type == XFS_DQ_PROJ ||
 842                type == XFS_DQ_GROUP);
 843         if (ip) {
 844                 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 845                 if (type == XFS_DQ_USER)
 846                         ASSERT(ip->i_udquot == NULL);
 847                 else
 848                         ASSERT(ip->i_gdquot == NULL);
 849         }
 850 #endif
 851         mutex_lock(&h->qh_lock);
 852
 853         /*
 854          * Look in the cache (hashtable).
 855          * The chain is kept locked during lookup.
 856          */
 857         if (xfs_qm_dqlookup(mp, id, h, O_dqpp) == 0) {
 858                 XQM_STATS_INC(xqmstats.xs_qm_dqcachehits);
 859                 /*
 860                  * The dquot was found, moved to the front of the chain,
 861                  * taken off the freelist if it was on it, and locked
 862                  * at this point. Just unlock the hashchain and return.
 863                  */
 864                 ASSERT(*O_dqpp);
 865                 ASSERT(XFS_DQ_IS_LOCKED(*O_dqpp));
 866                 mutex_unlock(&h->qh_lock);
 867                 trace_xfs_dqget_hit(*O_dqpp);
 868                 return (0);     /* success */
 869         }
 870         XQM_STATS_INC(xqmstats.xs_qm_dqcachemisses);
 871
 872         /*
 873          * Dquot cache miss. We don't want to keep the inode lock across
 874          * a (potential) disk read. Also we don't want to deal with the lock
 875          * ordering between quotainode and this inode. OTOH, dropping the inode
 876          * lock here means dealing with a chown that can happen before
 877          * we re-acquire the lock.
 878          */
 879         if (ip)
 880                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 881         /*
 882          * Save the hashchain version stamp, and unlock the chain, so that
 883          * we don't keep the lock across a disk read
 884          */
 885         version = h->qh_version;
 886         mutex_unlock(&h->qh_lock);
 887
 888         /*
 889          * Allocate the dquot on the kernel heap, and read the ondisk
 890          * portion off the disk. Also, do all the necessary initialization
 891          * This can return ENOENT if dquot didn't exist on disk and we didn't
 892          * ask it to allocate; ESRCH if quotas got turned off suddenly.
 893          */
 894         if ((error = xfs_qm_idtodq(mp, id, type,
 895                                   flags & (XFS_QMOPT_DQALLOC|XFS_QMOPT_DQREPAIR|
 896                                            XFS_QMOPT_DOWARN),
 897                                   &dqp))) {
 898                 if (ip)
 899                         xfs_ilock(ip, XFS_ILOCK_EXCL);
 900                 return (error);
 901         }
 902
 903         /*
 904          * See if this is mount code calling to look at the overall quota limits
 905          * which are stored in the id == 0 user or group's dquot.
 906          * Since we may not have done a quotacheck by this point, just return
 907          * the dquot without attaching it to any hashtables, lists, etc, or even
 908          * taking a reference.
 909          * The caller must dqdestroy this once done.
 910          */
 911         if (flags & XFS_QMOPT_DQSUSER) {
 912                 ASSERT(id == 0);
 913                 ASSERT(! ip);
 914                 goto dqret;
 915         }
 916
 917         /*
 918          * Dquot lock comes after hashlock in the lock ordering
 919          */
 920         if (ip) {
 921                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 922
 923                 /*
 924                  * A dquot could be attached to this inode by now, since
 925                  * we had dropped the ilock.
 926                  */
 927                 if (type == XFS_DQ_USER) {
 928                         if (!XFS_IS_UQUOTA_ON(mp)) {
 929                                 /* inode stays locked on return */
 930                                 xfs_qm_dqdestroy(dqp);
 931                                 return XFS_ERROR(ESRCH);
 932                         }
 933                         if (ip->i_udquot) {
 934                                 xfs_qm_dqdestroy(dqp);
 935                                 dqp = ip->i_udquot;
 936                                 xfs_dqlock(dqp);
 937                                 goto dqret;
 938                         }
 939                 } else {
 940                         if (!XFS_IS_OQUOTA_ON(mp)) {
 941                                 /* inode stays locked on return */
 942                                 xfs_qm_dqdestroy(dqp);
 943                                 return XFS_ERROR(ESRCH);
 944                         }
 945                         if (ip->i_gdquot) {
 946                                 xfs_qm_dqdestroy(dqp);
 947                                 dqp = ip->i_gdquot;
 948                                 xfs_dqlock(dqp);
 949                                 goto dqret;
 950                         }
 951                 }
 952         }
 953
 954         /*
 955          * Hashlock comes after ilock in lock order
 956          */
 957         mutex_lock(&h->qh_lock);
 958         if (version != h->qh_version) {
 959                 xfs_dquot_t *tmpdqp;
 960                 /*
 961                  * Now, see if somebody else put the dquot in the
 962                  * hashtable before us. This can happen because we didn't
 963                  * keep the hashchain lock. We don't have to worry about
 964                  * lock order between the two dquots here since dqp isn't
 965                  * on any findable lists yet.
 966                  */
 967                 if (xfs_qm_dqlookup(mp, id, h, &tmpdqp) == 0) {
 968                         /*
 969                          * Duplicate found. Just throw away the new dquot
 970                          * and start over.
 971                          */
 972                         xfs_qm_dqput(tmpdqp);
 973                         mutex_unlock(&h->qh_lock);
 974                         xfs_qm_dqdestroy(dqp);
 975                         XQM_STATS_INC(xqmstats.xs_qm_dquot_dups);
 976                         goto again;
 977                 }
 978         }
 979
 980         /*
 981          * Put the dquot at the beginning of the hash-chain and mp's list
 982          * LOCK ORDER: hashlock, freelistlock, mplistlock, udqlock, gdqlock ..
 983          */
 984         ASSERT(mutex_is_locked(&h->qh_lock));
 985         dqp->q_hash = h;
 986         list_add(&dqp->q_hashlist, &h->qh_list);
 987         h->qh_version++;
 988
 989         /*
 990          * Attach this dquot to this filesystem's list of all dquots,
 991          * kept inside the mount structure in m_quotainfo field
 992          */
 993         mutex_lock(&mp->m_quotainfo->qi_dqlist_lock);
 994
 995         /*
 996          * We return a locked dquot to the caller, with a reference taken
 997          */
 998         xfs_dqlock(dqp);
 999         dqp->q_nrefs = 1;
1000
1001         list_add(&dqp->q_mplist, &mp->m_quotainfo->qi_dqlist);
1002         mp->m_quotainfo->qi_dquots++;
1003         mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
1004         mutex_unlock(&h->qh_lock);
1005  dqret:
1006         ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
1007         trace_xfs_dqget_miss(dqp);
1008         *O_dqpp = dqp;
1009         return (0);
1010 }
1011
1012
1013 /*
1014  * Release a reference to the dquot (decrement ref-count)
1015  * and unlock it. If there is a group quota attached to this
1016  * dquot, carefully release that too without tripping over
1017  * deadlocks'n'stuff.
1018  */
1019 void
1020 xfs_qm_dqput(
1021         xfs_dquot_t     *dqp)
1022 {
1023         xfs_dquot_t     *gdqp;
1024
1025         ASSERT(dqp->q_nrefs > 0);
1026         ASSERT(XFS_DQ_IS_LOCKED(dqp));
1027
1028         trace_xfs_dqput(dqp);
1029
1030         if (dqp->q_nrefs != 1) {
1031                 dqp->q_nrefs--;
1032                 xfs_dqunlock(dqp);
1033                 return;
1034         }
1035
1036         /*
1037          * drop the dqlock and acquire the freelist and dqlock
1038          * in the right order; but try to get it out-of-order first
1039          */
1040         if (!mutex_trylock(&xfs_Gqm->qm_dqfrlist_lock)) {
1041                 trace_xfs_dqput_wait(dqp);
1042                 xfs_dqunlock(dqp);
1043                 mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
1044                 xfs_dqlock(dqp);
1045         }
1046
1047         while (1) {
1048                 gdqp = NULL;
1049
1050                 /* We can't depend on nrefs being == 1 here */
1051                 if (--dqp->q_nrefs == 0) {
1052                         trace_xfs_dqput_free(dqp);
1053
1054                         list_add_tail(&dqp->q_freelist, &xfs_Gqm->qm_dqfrlist);
1055                         xfs_Gqm->qm_dqfrlist_cnt++;
1056
1057                         /*
1058                          * If we just added a udquot to the freelist, then
1059                          * we want to release the gdquot reference that
1060                          * it (probably) has. Otherwise it'll keep the
1061                          * gdquot from getting reclaimed.
1062                          */
1063                         if ((gdqp = dqp->q_gdquot)) {
1064                                 /*
1065                                  * Avoid a recursive dqput call
1066                                  */
1067                                 xfs_dqlock(gdqp);
1068                                 dqp->q_gdquot = NULL;
1069                         }
1070                 }
1071                 xfs_dqunlock(dqp);
1072
1073                 /*
1074                  * If we had a group quota inside the user quota as a hint,
1075                  * release it now.
1076                  */
1077                 if (! gdqp)
1078                         break;
1079                 dqp = gdqp;
1080         }
1081         mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
1082 }
1083
1084 /*
1085  * Release a dquot. Flush it if dirty, then dqput() it.
1086  * dquot must not be locked.
1087  */
1088 void
1089 xfs_qm_dqrele(
1090         xfs_dquot_t     *dqp)
1091 {
1092         if (!dqp)
1093                 return;
1094
1095         trace_xfs_dqrele(dqp);
1096
1097         xfs_dqlock(dqp);
1098         /*
1099          * We don't care to flush it if the dquot is dirty here.
1100          * That will create stutters that we want to avoid.
1101          * Instead we do a delayed write when we try to reclaim
1102          * a dirty dquot. Also xfs_sync will take part of the burden...
1103          */
1104         xfs_qm_dqput(dqp);
1105 }
1106
1107 /*
1108  * This is the dquot flushing I/O completion routine.  It is called
1109  * from interrupt level when the buffer containing the dquot is
1110  * flushed to disk.  It is responsible for removing the dquot logitem
1111  * from the AIL if it has not been re-logged, and unlocking the dquot's
1112  * flush lock. This behavior is very similar to that of inodes..
1113  */
1114 STATIC void
1115 xfs_qm_dqflush_done(
1116         struct xfs_buf          *bp,
1117         struct xfs_log_item     *lip)
1118 {
1119         xfs_dq_logitem_t        *qip = (struct xfs_dq_logitem *)lip;
1120         xfs_dquot_t             *dqp = qip->qli_dquot;
1121         struct xfs_ail          *ailp = lip->li_ailp;
1122
1123         /*
1124          * We only want to pull the item from the AIL if its
1125          * location in the log has not changed since we started the flush.
1126          * Thus, we only bother if the dquot's lsn has
1127          * not changed. First we check the lsn outside the lock
1128          * since it's cheaper, and then we recheck while
1129          * holding the lock before removing the dquot from the AIL.
1130          */
1131         if ((lip->li_flags & XFS_LI_IN_AIL) &&
1132             lip->li_lsn == qip->qli_flush_lsn) {
1133
1134                 /* xfs_trans_ail_delete() drops the AIL lock. */
1135                 spin_lock(&ailp->xa_lock);
1136                 if (lip->li_lsn == qip->qli_flush_lsn)
1137                         xfs_trans_ail_delete(ailp, lip);
1138                 else
1139                         spin_unlock(&ailp->xa_lock);
1140         }
1141
1142         /*
1143          * Release the dq's flush lock since we're done with it.
1144          */
1145         xfs_dqfunlock(dqp);
1146 }
1147
1148 /*
1149  * Write a modified dquot to disk.
1150  * The dquot must be locked and the flush lock too taken by caller.
1151  * The flush lock will not be unlocked until the dquot reaches the disk,
1152  * but the dquot is free to be unlocked and modified by the caller
1153  * in the interim. Dquot is still locked on return. This behavior is
1154  * identical to that of inodes.
1155  */
1156 int
1157 xfs_qm_dqflush(
1158         xfs_dquot_t             *dqp,
1159         uint                    flags)
1160 {
1161         struct xfs_mount        *mp = dqp->q_mount;
1162         struct xfs_buf          *bp;
1163         struct xfs_disk_dquot   *ddqp;
1164         int                     error;
1165
1166         ASSERT(XFS_DQ_IS_LOCKED(dqp));
1167         ASSERT(!completion_done(&dqp->q_flush));
1168
1169         trace_xfs_dqflush(dqp);
1170
1171         /*
1172          * If not dirty, or it's pinned and we are not supposed to block, nada.
1173          */
1174         if (!XFS_DQ_IS_DIRTY(dqp) ||
1175             (!(flags & SYNC_WAIT) && atomic_read(&dqp->q_pincount) > 0)) {
1176                 xfs_dqfunlock(dqp);
1177                 return 0;
1178         }
1179         xfs_qm_dqunpin_wait(dqp);
1180
1181         /*
1182          * This may have been unpinned because the filesystem is shutting
1183          * down forcibly. If that's the case we must not write this dquot
1184          * to disk, because the log record didn't make it to disk!
1185          */
1186         if (XFS_FORCED_SHUTDOWN(mp)) {
1187                 dqp->dq_flags &= ~XFS_DQ_DIRTY;
1188                 xfs_dqfunlock(dqp);
1189                 return XFS_ERROR(EIO);
1190         }
1191
1192         /*
1193          * Get the buffer containing the on-disk dquot
1194          */
1195         error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
1196                                    mp->m_quotainfo->qi_dqchunklen, 0, &bp);
1197         if (error) {
1198                 ASSERT(error != ENOENT);
1199                 xfs_dqfunlock(dqp);
1200                 return error;
1201         }
1202
1203         /*
1204          * Calculate the location of the dquot inside the buffer.
1205          */
1206         ddqp = (struct xfs_disk_dquot *)(XFS_BUF_PTR(bp) + dqp->q_bufoffset);
1207
1208         /*
1209          * A simple sanity check in case we got a corrupted dquot..
1210          */
1211         if (xfs_qm_dqcheck(&dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
1212                            XFS_QMOPT_DOWARN, "dqflush (incore copy)")) {
1213                 xfs_buf_relse(bp);
1214                 xfs_dqfunlock(dqp);
1215                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1216                 return XFS_ERROR(EIO);
1217         }
1218
1219         /* This is the only portion of data that needs to persist */
1220         memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
1221
1222         /*
1223          * Clear the dirty field and remember the flush lsn for later use.
1224          */
1225         dqp->dq_flags &= ~XFS_DQ_DIRTY;
1226
1227         xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1228                                         &dqp->q_logitem.qli_item.li_lsn);
1229
1230         /*
1231          * Attach an iodone routine so that we can remove this dquot from the
1232          * AIL and release the flush lock once the dquot is synced to disk.
1233          */
1234         xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1235                                   &dqp->q_logitem.qli_item);
1236
1237         /*
1238          * If the buffer is pinned then push on the log so we won't
1239          * get stuck waiting in the write for too long.
1240          */
1241         if (XFS_BUF_ISPINNED(bp)) {
1242                 trace_xfs_dqflush_force(dqp);
1243                 xfs_log_force(mp, 0);
1244         }
1245
1246         if (flags & SYNC_WAIT)
1247                 error = xfs_bwrite(mp, bp);
1248         else
1249                 xfs_bdwrite(mp, bp);
1250
1251         trace_xfs_dqflush_done(dqp);
1252
1253         /*
1254          * dqp is still locked, but caller is free to unlock it now.
1255          */
1256         return error;
1257
1258 }
1259
1260 int
1261 xfs_qm_dqlock_nowait(
1262         xfs_dquot_t *dqp)
1263 {
1264         return mutex_trylock(&dqp->q_qlock);
1265 }
1266
1267 void
1268 xfs_dqlock(
1269         xfs_dquot_t *dqp)
1270 {
1271         mutex_lock(&dqp->q_qlock);
1272 }
1273
1274 void
1275 xfs_dqunlock(
1276         xfs_dquot_t *dqp)
1277 {
1278         mutex_unlock(&(dqp->q_qlock));
1279         if (dqp->q_logitem.qli_dquot == dqp) {
1280                 /* Once was dqp->q_mount, but might just have been cleared */
1281                 xfs_trans_unlocked_item(dqp->q_logitem.qli_item.li_ailp,
1282                                         (xfs_log_item_t*)&(dqp->q_logitem));
1283         }
1284 }
1285
1286
1287 void
1288 xfs_dqunlock_nonotify(
1289         xfs_dquot_t *dqp)
1290 {
1291         mutex_unlock(&(dqp->q_qlock));
1292 }
1293
1294 /*
1295  * Lock two xfs_dquot structures.
1296  *
1297  * To avoid deadlocks we always lock the quota structure with
1298  * the lowerd id first.
1299  */
1300 void
1301 xfs_dqlock2(
1302         xfs_dquot_t     *d1,
1303         xfs_dquot_t     *d2)
1304 {
1305         if (d1 && d2) {
1306                 ASSERT(d1 != d2);
1307                 if (be32_to_cpu(d1->q_core.d_id) >
1308                     be32_to_cpu(d2->q_core.d_id)) {
1309                         mutex_lock(&d2->q_qlock);
1310                         mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1311                 } else {
1312                         mutex_lock(&d1->q_qlock);
1313                         mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1314                 }
1315         } else if (d1) {
1316                 mutex_lock(&d1->q_qlock);
1317         } else if (d2) {
1318                 mutex_lock(&d2->q_qlock);
1319         }
1320 }
1321
1322
1323 /*
1324  * Take a dquot out of the mount's dqlist as well as the hashlist.
1325  * This is called via unmount as well as quotaoff, and the purge
1326  * will always succeed unless there are soft (temp) references
1327  * outstanding.
1328  *
1329  * This returns 0 if it was purged, 1 if it wasn't. It's not an error code
1330  * that we're returning! XXXsup - not cool.
1331  */
1332 /* ARGSUSED */
1333 int
1334 xfs_qm_dqpurge(
1335         xfs_dquot_t     *dqp)
1336 {
1337         xfs_dqhash_t    *qh = dqp->q_hash;
1338         xfs_mount_t     *mp = dqp->q_mount;
1339
1340         ASSERT(mutex_is_locked(&mp->m_quotainfo->qi_dqlist_lock));
1341         ASSERT(mutex_is_locked(&dqp->q_hash->qh_lock));
1342
1343         xfs_dqlock(dqp);
1344         /*
1345          * We really can't afford to purge a dquot that is
1346          * referenced, because these are hard refs.
1347          * It shouldn't happen in general because we went thru _all_ inodes in
1348          * dqrele_all_inodes before calling this and didn't let the mountlock go.
1349          * However it is possible that we have dquots with temporary
1350          * references that are not attached to an inode. e.g. see xfs_setattr().
1351          */
1352         if (dqp->q_nrefs != 0) {
1353                 xfs_dqunlock(dqp);
1354                 mutex_unlock(&dqp->q_hash->qh_lock);
1355                 return (1);
1356         }
1357
1358         ASSERT(!list_empty(&dqp->q_freelist));
1359
1360         /*
1361          * If we're turning off quotas, we have to make sure that, for
1362          * example, we don't delete quota disk blocks while dquots are
1363          * in the process of getting written to those disk blocks.
1364          * This dquot might well be on AIL, and we can't leave it there
1365          * if we're turning off quotas. Basically, we need this flush
1366          * lock, and are willing to block on it.
1367          */
1368         if (!xfs_dqflock_nowait(dqp)) {
1369                 /*
1370                  * Block on the flush lock after nudging dquot buffer,
1371                  * if it is incore.
1372                  */
1373                 xfs_qm_dqflock_pushbuf_wait(dqp);
1374         }
1375
1376         /*
1377          * XXXIf we're turning this type of quotas off, we don't care
1378          * about the dirty metadata sitting in this dquot. OTOH, if
1379          * we're unmounting, we do care, so we flush it and wait.
1380          */
1381         if (XFS_DQ_IS_DIRTY(dqp)) {
1382                 int     error;
1383
1384                 /* dqflush unlocks dqflock */
1385                 /*
1386                  * Given that dqpurge is a very rare occurrence, it is OK
1387                  * that we're holding the hashlist and mplist locks
1388                  * across the disk write. But, ... XXXsup
1389                  *
1390                  * We don't care about getting disk errors here. We need
1391                  * to purge this dquot anyway, so we go ahead regardless.
1392                  */
1393                 error = xfs_qm_dqflush(dqp, SYNC_WAIT);
1394                 if (error)
1395                         xfs_fs_cmn_err(CE_WARN, mp,
1396                                 "xfs_qm_dqpurge: dquot %p flush failed", dqp);
1397                 xfs_dqflock(dqp);
1398         }
1399         ASSERT(atomic_read(&dqp->q_pincount) == 0);
1400         ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
1401                !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));
1402
1403         list_del_init(&dqp->q_hashlist);
1404         qh->qh_version++;
1405         list_del_init(&dqp->q_mplist);
1406         mp->m_quotainfo->qi_dqreclaims++;
1407         mp->m_quotainfo->qi_dquots--;
1408         /*
1409          * XXX Move this to the front of the freelist, if we can get the
1410          * freelist lock.
1411          */
1412         ASSERT(!list_empty(&dqp->q_freelist));
1413
1414         dqp->q_mount = NULL;
1415         dqp->q_hash = NULL;
1416         dqp->dq_flags = XFS_DQ_INACTIVE;
1417         memset(&dqp->q_core, 0, sizeof(dqp->q_core));
1418         xfs_dqfunlock(dqp);
1419         xfs_dqunlock(dqp);
1420         mutex_unlock(&qh->qh_lock);
1421         return (0);
1422 }
1423
1424
1425 #ifdef QUOTADEBUG
1426 void
1427 xfs_qm_dqprint(xfs_dquot_t *dqp)
1428 {
1429         cmn_err(CE_DEBUG, "-----------KERNEL DQUOT----------------");
1430         cmn_err(CE_DEBUG, "---- dquotID =  %d",
1431                 (int)be32_to_cpu(dqp->q_core.d_id));
1432         cmn_err(CE_DEBUG, "---- type    =  %s", DQFLAGTO_TYPESTR(dqp));
1433         cmn_err(CE_DEBUG, "---- fs      =  0x%p", dqp->q_mount);
1434         cmn_err(CE_DEBUG, "---- blkno   =  0x%x", (int) dqp->q_blkno);
1435         cmn_err(CE_DEBUG, "---- boffset =  0x%x", (int) dqp->q_bufoffset);
1436         cmn_err(CE_DEBUG, "---- blkhlimit =  %Lu (0x%x)",
1437                 be64_to_cpu(dqp->q_core.d_blk_hardlimit),
1438                 (int)be64_to_cpu(dqp->q_core.d_blk_hardlimit));
1439         cmn_err(CE_DEBUG, "---- blkslimit =  %Lu (0x%x)",
1440                 be64_to_cpu(dqp->q_core.d_blk_softlimit),
1441                 (int)be64_to_cpu(dqp->q_core.d_blk_softlimit));
1442         cmn_err(CE_DEBUG, "---- inohlimit =  %Lu (0x%x)",
1443                 be64_to_cpu(dqp->q_core.d_ino_hardlimit),
1444                 (int)be64_to_cpu(dqp->q_core.d_ino_hardlimit));
1445         cmn_err(CE_DEBUG, "---- inoslimit =  %Lu (0x%x)",
1446                 be64_to_cpu(dqp->q_core.d_ino_softlimit),
1447                 (int)be64_to_cpu(dqp->q_core.d_ino_softlimit));
1448         cmn_err(CE_DEBUG, "---- bcount  =  %Lu (0x%x)",
1449                 be64_to_cpu(dqp->q_core.d_bcount),
1450                 (int)be64_to_cpu(dqp->q_core.d_bcount));
1451         cmn_err(CE_DEBUG, "---- icount  =  %Lu (0x%x)",
1452                 be64_to_cpu(dqp->q_core.d_icount),
1453                 (int)be64_to_cpu(dqp->q_core.d_icount));
1454         cmn_err(CE_DEBUG, "---- btimer  =  %d",
1455                 (int)be32_to_cpu(dqp->q_core.d_btimer));
1456         cmn_err(CE_DEBUG, "---- itimer  =  %d",
1457                 (int)be32_to_cpu(dqp->q_core.d_itimer));
1458         cmn_err(CE_DEBUG, "---------------------------");
1459 }
1460 #endif
1461
1462 /*
1463  * Give the buffer a little push if it is incore and
1464  * wait on the flush lock.
1465  */
1466 void
1467 xfs_qm_dqflock_pushbuf_wait(
1468         xfs_dquot_t     *dqp)
1469 {
1470         xfs_mount_t     *mp = dqp->q_mount;
1471         xfs_buf_t       *bp;
1472
1473         /*
1474          * Check to see if the dquot has been flushed delayed
1475          * write.  If so, grab its buffer and send it
1476          * out immediately.  We'll be able to acquire
1477          * the flush lock when the I/O completes.
1478          */
1479         bp = xfs_incore(mp->m_ddev_targp, dqp->q_blkno,
1480                         mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK);
1481         if (!bp)
1482                 goto out_lock;
1483
1484         if (XFS_BUF_ISDELAYWRITE(bp)) {
1485                 if (XFS_BUF_ISPINNED(bp))
1486                         xfs_log_force(mp, 0);
1487                 xfs_buf_delwri_promote(bp);
1488                 wake_up_process(bp->b_target->bt_task);
1489         }
1490         xfs_buf_relse(bp);
1491 out_lock:
1492         xfs_dqflock(dqp);
1493 }