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         kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
 153
 154         atomic_dec(&xfs_Gqm->qm_totaldquots);
 155 }
 156
 157 /*
 158  * This is what a 'fresh' dquot inside a dquot chunk looks like on disk.
 159  */
 160 STATIC void
 161 xfs_qm_dqinit_core(
 162         xfs_dqid_t      id,
 163         uint            type,
 164         xfs_dqblk_t     *d)
 165 {
 166         /*
 167          * Caller has zero'd the entire dquot 'chunk' already.
 168          */
 169         d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 170         d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 171         d->dd_diskdq.d_id = cpu_to_be32(id);
 172         d->dd_diskdq.d_flags = type;
 173 }
 174
 175 /*
 176  * If default limits are in force, push them into the dquot now.
 177  * We overwrite the dquot limits only if they are zero and this
 178  * is not the root dquot.
 179  */
 180 void
 181 xfs_qm_adjust_dqlimits(
 182         xfs_mount_t             *mp,
 183         xfs_disk_dquot_t        *d)
 184 {
 185         xfs_quotainfo_t         *q = mp->m_quotainfo;
 186
 187         ASSERT(d->d_id);
 188
 189         if (q->qi_bsoftlimit && !d->d_blk_softlimit)
 190                 d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
 191         if (q->qi_bhardlimit && !d->d_blk_hardlimit)
 192                 d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
 193         if (q->qi_isoftlimit && !d->d_ino_softlimit)
 194                 d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
 195         if (q->qi_ihardlimit && !d->d_ino_hardlimit)
 196                 d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
 197         if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
 198                 d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
 199         if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
 200                 d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
 201 }
 202
 203 /*
 204  * Check the limits and timers of a dquot and start or reset timers
 205  * if necessary.
 206  * This gets called even when quota enforcement is OFF, which makes our
 207  * life a little less complicated. (We just don't reject any quota
 208  * reservations in that case, when enforcement is off).
 209  * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
 210  * enforcement's off.
 211  * In contrast, warnings are a little different in that they don't
 212  * 'automatically' get started when limits get exceeded.  They do
 213  * get reset to zero, however, when we find the count to be under
 214  * the soft limit (they are only ever set non-zero via userspace).
 215  */
 216 void
 217 xfs_qm_adjust_dqtimers(
 218         xfs_mount_t             *mp,
 219         xfs_disk_dquot_t        *d)
 220 {
 221         ASSERT(d->d_id);
 222
 223 #ifdef QUOTADEBUG
 224         if (d->d_blk_hardlimit)
 225                 ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
 226                        be64_to_cpu(d->d_blk_hardlimit));
 227         if (d->d_ino_hardlimit)
 228                 ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
 229                        be64_to_cpu(d->d_ino_hardlimit));
 230         if (d->d_rtb_hardlimit)
 231                 ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
 232                        be64_to_cpu(d->d_rtb_hardlimit));
 233 #endif
 234         if (!d->d_btimer) {
 235                 if ((d->d_blk_softlimit &&
 236                      (be64_to_cpu(d->d_bcount) >=
 237                       be64_to_cpu(d->d_blk_softlimit))) ||
 238                     (d->d_blk_hardlimit &&
 239                      (be64_to_cpu(d->d_bcount) >=
 240                       be64_to_cpu(d->d_blk_hardlimit)))) {
 241                         d->d_btimer = cpu_to_be32(get_seconds() +
 242                                         mp->m_quotainfo->qi_btimelimit);
 243                 } else {
 244                         d->d_bwarns = 0;
 245                 }
 246         } else {
 247                 if ((!d->d_blk_softlimit ||
 248                      (be64_to_cpu(d->d_bcount) <
 249                       be64_to_cpu(d->d_blk_softlimit))) &&
 250                     (!d->d_blk_hardlimit ||
 251                     (be64_to_cpu(d->d_bcount) <
 252                      be64_to_cpu(d->d_blk_hardlimit)))) {
 253                         d->d_btimer = 0;
 254                 }
 255         }
 256
 257         if (!d->d_itimer) {
 258                 if ((d->d_ino_softlimit &&
 259                      (be64_to_cpu(d->d_icount) >=
 260                       be64_to_cpu(d->d_ino_softlimit))) ||
 261                     (d->d_ino_hardlimit &&
 262                      (be64_to_cpu(d->d_icount) >=
 263                       be64_to_cpu(d->d_ino_hardlimit)))) {
 264                         d->d_itimer = cpu_to_be32(get_seconds() +
 265                                         mp->m_quotainfo->qi_itimelimit);
 266                 } else {
 267                         d->d_iwarns = 0;
 268                 }
 269         } else {
 270                 if ((!d->d_ino_softlimit ||
 271                      (be64_to_cpu(d->d_icount) <
 272                       be64_to_cpu(d->d_ino_softlimit)))  &&
 273                     (!d->d_ino_hardlimit ||
 274                      (be64_to_cpu(d->d_icount) <
 275                       be64_to_cpu(d->d_ino_hardlimit)))) {
 276                         d->d_itimer = 0;
 277                 }
 278         }
 279
 280         if (!d->d_rtbtimer) {
 281                 if ((d->d_rtb_softlimit &&
 282                      (be64_to_cpu(d->d_rtbcount) >=
 283                       be64_to_cpu(d->d_rtb_softlimit))) ||
 284                     (d->d_rtb_hardlimit &&
 285                      (be64_to_cpu(d->d_rtbcount) >=
 286                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 287                         d->d_rtbtimer = cpu_to_be32(get_seconds() +
 288                                         mp->m_quotainfo->qi_rtbtimelimit);
 289                 } else {
 290                         d->d_rtbwarns = 0;
 291                 }
 292         } else {
 293                 if ((!d->d_rtb_softlimit ||
 294                      (be64_to_cpu(d->d_rtbcount) <
 295                       be64_to_cpu(d->d_rtb_softlimit))) &&
 296                     (!d->d_rtb_hardlimit ||
 297                      (be64_to_cpu(d->d_rtbcount) <
 298                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 299                         d->d_rtbtimer = 0;
 300                 }
 301         }
 302 }
 303
 304 /*
 305  * initialize a buffer full of dquots and log the whole thing
 306  */
 307 STATIC void
 308 xfs_qm_init_dquot_blk(
 309         xfs_trans_t     *tp,
 310         xfs_mount_t     *mp,
 311         xfs_dqid_t      id,
 312         uint            type,
 313         xfs_buf_t       *bp)
 314 {
 315         struct xfs_quotainfo    *q = mp->m_quotainfo;
 316         xfs_dqblk_t     *d;
 317         int             curid, i;
 318
 319         ASSERT(tp);
 320         ASSERT(XFS_BUF_ISBUSY(bp));
 321         ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 322
 323         d = (xfs_dqblk_t *)XFS_BUF_PTR(bp);
 324
 325         /*
 326          * ID of the first dquot in the block - id's are zero based.
 327          */
 328         curid = id - (id % q->qi_dqperchunk);
 329         ASSERT(curid >= 0);
 330         memset(d, 0, BBTOB(q->qi_dqchunklen));
 331         for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++)
 332                 xfs_qm_dqinit_core(curid, type, d);
 333         xfs_trans_dquot_buf(tp, bp,
 334                             (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
 335                             ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
 336                              XFS_BLF_GDQUOT_BUF)));
 337         xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
 338 }
 339
 340
 341
 342 /*
 343  * Allocate a block and fill it with dquots.
 344  * This is called when the bmapi finds a hole.
 345  */
 346 STATIC int
 347 xfs_qm_dqalloc(
 348         xfs_trans_t     **tpp,
 349         xfs_mount_t     *mp,
 350         xfs_dquot_t     *dqp,
 351         xfs_inode_t     *quotip,
 352         xfs_fileoff_t   offset_fsb,
 353         xfs_buf_t       **O_bpp)
 354 {
 355         xfs_fsblock_t   firstblock;
 356         xfs_bmap_free_t flist;
 357         xfs_bmbt_irec_t map;
 358         int             nmaps, error, committed;
 359         xfs_buf_t       *bp;
 360         xfs_trans_t     *tp = *tpp;
 361
 362         ASSERT(tp != NULL);
 363
 364         trace_xfs_dqalloc(dqp);
 365
 366         /*
 367          * Initialize the bmap freelist prior to calling bmapi code.
 368          */
 369         xfs_bmap_init(&flist, &firstblock);
 370         xfs_ilock(quotip, XFS_ILOCK_EXCL);
 371         /*
 372          * Return if this type of quotas is turned off while we didn't
 373          * have an inode lock
 374          */
 375         if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
 376                 xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 377                 return (ESRCH);
 378         }
 379
 380         xfs_trans_ijoin_ref(tp, quotip, XFS_ILOCK_EXCL);
 381         nmaps = 1;
 382         if ((error = xfs_bmapi(tp, quotip,
 383                               offset_fsb, XFS_DQUOT_CLUSTER_SIZE_FSB,
 384                               XFS_BMAPI_METADATA | XFS_BMAPI_WRITE,
 385                               &firstblock,
 386                               XFS_QM_DQALLOC_SPACE_RES(mp),
 387                               &map, &nmaps, &flist))) {
 388                 goto error0;
 389         }
 390         ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
 391         ASSERT(nmaps == 1);
 392         ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 393                (map.br_startblock != HOLESTARTBLOCK));
 394
 395         /*
 396          * Keep track of the blkno to save a lookup later
 397          */
 398         dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 399
 400         /* now we can just get the buffer (there's nothing to read yet) */
 401         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
 402                                dqp->q_blkno,
 403                                mp->m_quotainfo->qi_dqchunklen,
 404                                0);
 405         if (!bp || (error = XFS_BUF_GETERROR(bp)))
 406                 goto error1;
 407         /*
 408          * Make a chunk of dquots out of this buffer and log
 409          * the entire thing.
 410          */
 411         xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
 412                               dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
 413
 414         /*
 415          * xfs_bmap_finish() may commit the current transaction and
 416          * start a second transaction if the freelist is not empty.
 417          *
 418          * Since we still want to modify this buffer, we need to
 419          * ensure that the buffer is not released on commit of
 420          * the first transaction and ensure the buffer is added to the
 421          * second transaction.
 422          *
 423          * If there is only one transaction then don't stop the buffer
 424          * from being released when it commits later on.
 425          */
 426
 427         xfs_trans_bhold(tp, bp);
 428
 429         if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
 430                 goto error1;
 431         }
 432
 433         if (committed) {
 434                 tp = *tpp;
 435                 xfs_trans_bjoin(tp, bp);
 436         } else {
 437                 xfs_trans_bhold_release(tp, bp);
 438         }
 439
 440         *O_bpp = bp;
 441         return 0;
 442
 443       error1:
 444         xfs_bmap_cancel(&flist);
 445       error0:
 446         xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 447
 448         return (error);
 449 }
 450
 451 /*
 452  * Maps a dquot to the buffer containing its on-disk version.
 453  * This returns a ptr to the buffer containing the on-disk dquot
 454  * in the bpp param, and a ptr to the on-disk dquot within that buffer
 455  */
 456 STATIC int
 457 xfs_qm_dqtobp(
 458         xfs_trans_t             **tpp,
 459         xfs_dquot_t             *dqp,
 460         xfs_disk_dquot_t        **O_ddpp,
 461         xfs_buf_t               **O_bpp,
 462         uint                    flags)
 463 {
 464         xfs_bmbt_irec_t map;
 465         int             nmaps = 1, error;
 466         xfs_buf_t       *bp;
 467         xfs_inode_t     *quotip = XFS_DQ_TO_QIP(dqp);
 468         xfs_mount_t     *mp = dqp->q_mount;
 469         xfs_disk_dquot_t *ddq;
 470         xfs_dqid_t      id = be32_to_cpu(dqp->q_core.d_id);
 471         xfs_trans_t     *tp = (tpp ? *tpp : NULL);
 472
 473         dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
 474
 475         xfs_ilock(quotip, XFS_ILOCK_SHARED);
 476         if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
 477                 /*
 478                  * Return if this type of quotas is turned off while we
 479                  * didn't have the quota inode lock.
 480                  */
 481                 xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 482                 return ESRCH;
 483         }
 484
 485         /*
 486          * Find the block map; no allocations yet
 487          */
 488         error = xfs_bmapi(NULL, quotip, dqp->q_fileoffset,
 489                           XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
 490                           NULL, 0, &map, &nmaps, NULL);
 491
 492         xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 493         if (error)
 494                 return error;
 495
 496         ASSERT(nmaps == 1);
 497         ASSERT(map.br_blockcount == 1);
 498
 499         /*
 500          * Offset of dquot in the (fixed sized) dquot chunk.
 501          */
 502         dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
 503                 sizeof(xfs_dqblk_t);
 504
 505         ASSERT(map.br_startblock != DELAYSTARTBLOCK);
 506         if (map.br_startblock == HOLESTARTBLOCK) {
 507                 /*
 508                  * We don't allocate unless we're asked to
 509                  */
 510                 if (!(flags & XFS_QMOPT_DQALLOC))
 511                         return ENOENT;
 512
 513                 ASSERT(tp);
 514                 error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
 515                                         dqp->q_fileoffset, &bp);
 516                 if (error)
 517                         return error;
 518                 tp = *tpp;
 519         } else {
 520                 trace_xfs_dqtobp_read(dqp);
 521
 522                 /*
 523                  * store the blkno etc so that we don't have to do the
 524                  * mapping all the time
 525                  */
 526                 dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 527
 528                 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 529                                            dqp->q_blkno,
 530                                            mp->m_quotainfo->qi_dqchunklen,
 531                                            0, &bp);
 532                 if (error || !bp)
 533                         return XFS_ERROR(error);
 534         }
 535
 536         ASSERT(XFS_BUF_ISBUSY(bp));
 537         ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 538
 539         /*
 540          * calculate the location of the dquot inside the buffer.
 541          */
 542         ddq = (struct xfs_disk_dquot *)(XFS_BUF_PTR(bp) + dqp->q_bufoffset);
 543
 544         /*
 545          * A simple sanity check in case we got a corrupted dquot...
 546          */
 547         error = xfs_qm_dqcheck(mp, ddq, id, dqp->dq_flags & XFS_DQ_ALLTYPES,
 548                            flags & (XFS_QMOPT_DQREPAIR|XFS_QMOPT_DOWARN),
 549                            "dqtobp");
 550         if (error) {
 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                         xfs_debug(mp, "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         error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
1212                            XFS_QMOPT_DOWARN, "dqflush (incore copy)");
1213         if (error) {
1214                 xfs_buf_relse(bp);
1215                 xfs_dqfunlock(dqp);
1216                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1217                 return XFS_ERROR(EIO);
1218         }
1219
1220         /* This is the only portion of data that needs to persist */
1221         memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
1222
1223         /*
1224          * Clear the dirty field and remember the flush lsn for later use.
1225          */
1226         dqp->dq_flags &= ~XFS_DQ_DIRTY;
1227
1228         xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1229                                         &dqp->q_logitem.qli_item.li_lsn);
1230
1231         /*
1232          * Attach an iodone routine so that we can remove this dquot from the
1233          * AIL and release the flush lock once the dquot is synced to disk.
1234          */
1235         xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1236                                   &dqp->q_logitem.qli_item);
1237
1238         /*
1239          * If the buffer is pinned then push on the log so we won't
1240          * get stuck waiting in the write for too long.
1241          */
1242         if (XFS_BUF_ISPINNED(bp)) {
1243                 trace_xfs_dqflush_force(dqp);
1244                 xfs_log_force(mp, 0);
1245         }
1246
1247         if (flags & SYNC_WAIT)
1248                 error = xfs_bwrite(mp, bp);
1249         else
1250                 xfs_bdwrite(mp, bp);
1251
1252         trace_xfs_dqflush_done(dqp);
1253
1254         /*
1255          * dqp is still locked, but caller is free to unlock it now.
1256          */
1257         return error;
1258
1259 }
1260
1261 int
1262 xfs_qm_dqlock_nowait(
1263         xfs_dquot_t *dqp)
1264 {
1265         return mutex_trylock(&dqp->q_qlock);
1266 }
1267
1268 void
1269 xfs_dqlock(
1270         xfs_dquot_t *dqp)
1271 {
1272         mutex_lock(&dqp->q_qlock);
1273 }
1274
1275 void
1276 xfs_dqunlock(
1277         xfs_dquot_t *dqp)
1278 {
1279         mutex_unlock(&(dqp->q_qlock));
1280         if (dqp->q_logitem.qli_dquot == dqp) {
1281                 /* Once was dqp->q_mount, but might just have been cleared */
1282                 xfs_trans_unlocked_item(dqp->q_logitem.qli_item.li_ailp,
1283                                         (xfs_log_item_t*)&(dqp->q_logitem));
1284         }
1285 }
1286
1287
1288 void
1289 xfs_dqunlock_nonotify(
1290         xfs_dquot_t *dqp)
1291 {
1292         mutex_unlock(&(dqp->q_qlock));
1293 }
1294
1295 /*
1296  * Lock two xfs_dquot structures.
1297  *
1298  * To avoid deadlocks we always lock the quota structure with
1299  * the lowerd id first.
1300  */
1301 void
1302 xfs_dqlock2(
1303         xfs_dquot_t     *d1,
1304         xfs_dquot_t     *d2)
1305 {
1306         if (d1 && d2) {
1307                 ASSERT(d1 != d2);
1308                 if (be32_to_cpu(d1->q_core.d_id) >
1309                     be32_to_cpu(d2->q_core.d_id)) {
1310                         mutex_lock(&d2->q_qlock);
1311                         mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1312                 } else {
1313                         mutex_lock(&d1->q_qlock);
1314                         mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1315                 }
1316         } else if (d1) {
1317                 mutex_lock(&d1->q_qlock);
1318         } else if (d2) {
1319                 mutex_lock(&d2->q_qlock);
1320         }
1321 }
1322
1323
1324 /*
1325  * Take a dquot out of the mount's dqlist as well as the hashlist.
1326  * This is called via unmount as well as quotaoff, and the purge
1327  * will always succeed unless there are soft (temp) references
1328  * outstanding.
1329  *
1330  * This returns 0 if it was purged, 1 if it wasn't. It's not an error code
1331  * that we're returning! XXXsup - not cool.
1332  */
1333 /* ARGSUSED */
1334 int
1335 xfs_qm_dqpurge(
1336         xfs_dquot_t     *dqp)
1337 {
1338         xfs_dqhash_t    *qh = dqp->q_hash;
1339         xfs_mount_t     *mp = dqp->q_mount;
1340
1341         ASSERT(mutex_is_locked(&mp->m_quotainfo->qi_dqlist_lock));
1342         ASSERT(mutex_is_locked(&dqp->q_hash->qh_lock));
1343
1344         xfs_dqlock(dqp);
1345         /*
1346          * We really can't afford to purge a dquot that is
1347          * referenced, because these are hard refs.
1348          * It shouldn't happen in general because we went thru _all_ inodes in
1349          * dqrele_all_inodes before calling this and didn't let the mountlock go.
1350          * However it is possible that we have dquots with temporary
1351          * references that are not attached to an inode. e.g. see xfs_setattr().
1352          */
1353         if (dqp->q_nrefs != 0) {
1354                 xfs_dqunlock(dqp);
1355                 mutex_unlock(&dqp->q_hash->qh_lock);
1356                 return (1);
1357         }
1358
1359         ASSERT(!list_empty(&dqp->q_freelist));
1360
1361         /*
1362          * If we're turning off quotas, we have to make sure that, for
1363          * example, we don't delete quota disk blocks while dquots are
1364          * in the process of getting written to those disk blocks.
1365          * This dquot might well be on AIL, and we can't leave it there
1366          * if we're turning off quotas. Basically, we need this flush
1367          * lock, and are willing to block on it.
1368          */
1369         if (!xfs_dqflock_nowait(dqp)) {
1370                 /*
1371                  * Block on the flush lock after nudging dquot buffer,
1372                  * if it is incore.
1373                  */
1374                 xfs_qm_dqflock_pushbuf_wait(dqp);
1375         }
1376
1377         /*
1378          * XXXIf we're turning this type of quotas off, we don't care
1379          * about the dirty metadata sitting in this dquot. OTOH, if
1380          * we're unmounting, we do care, so we flush it and wait.
1381          */
1382         if (XFS_DQ_IS_DIRTY(dqp)) {
1383                 int     error;
1384
1385                 /* dqflush unlocks dqflock */
1386                 /*
1387                  * Given that dqpurge is a very rare occurrence, it is OK
1388                  * that we're holding the hashlist and mplist locks
1389                  * across the disk write. But, ... XXXsup
1390                  *
1391                  * We don't care about getting disk errors here. We need
1392                  * to purge this dquot anyway, so we go ahead regardless.
1393                  */
1394                 error = xfs_qm_dqflush(dqp, SYNC_WAIT);
1395                 if (error)
1396                         xfs_warn(mp, "%s: dquot %p flush failed",
1397                                 __func__, dqp);
1398                 xfs_dqflock(dqp);
1399         }
1400         ASSERT(atomic_read(&dqp->q_pincount) == 0);
1401         ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
1402                !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));
1403
1404         list_del_init(&dqp->q_hashlist);
1405         qh->qh_version++;
1406         list_del_init(&dqp->q_mplist);
1407         mp->m_quotainfo->qi_dqreclaims++;
1408         mp->m_quotainfo->qi_dquots--;
1409         /*
1410          * XXX Move this to the front of the freelist, if we can get the
1411          * freelist lock.
1412          */
1413         ASSERT(!list_empty(&dqp->q_freelist));
1414
1415         dqp->q_mount = NULL;
1416         dqp->q_hash = NULL;
1417         dqp->dq_flags = XFS_DQ_INACTIVE;
1418         memset(&dqp->q_core, 0, sizeof(dqp->q_core));
1419         xfs_dqfunlock(dqp);
1420         xfs_dqunlock(dqp);
1421         mutex_unlock(&qh->qh_lock);
1422         return (0);
1423 }
1424
1425
1426 #ifdef QUOTADEBUG
1427 void
1428 xfs_qm_dqprint(xfs_dquot_t *dqp)
1429 {
1430         struct xfs_mount        *mp = dqp->q_mount;
1431
1432         xfs_debug(mp, "-----------KERNEL DQUOT----------------");
1433         xfs_debug(mp, "---- dquotID =  %d",
1434                 (int)be32_to_cpu(dqp->q_core.d_id));
1435         xfs_debug(mp, "---- type    =  %s", DQFLAGTO_TYPESTR(dqp));
1436         xfs_debug(mp, "---- fs      =  0x%p", dqp->q_mount);
1437         xfs_debug(mp, "---- blkno   =  0x%x", (int) dqp->q_blkno);
1438         xfs_debug(mp, "---- boffset =  0x%x", (int) dqp->q_bufoffset);
1439         xfs_debug(mp, "---- blkhlimit =  %Lu (0x%x)",
1440                 be64_to_cpu(dqp->q_core.d_blk_hardlimit),
1441                 (int)be64_to_cpu(dqp->q_core.d_blk_hardlimit));
1442         xfs_debug(mp, "---- blkslimit =  %Lu (0x%x)",
1443                 be64_to_cpu(dqp->q_core.d_blk_softlimit),
1444                 (int)be64_to_cpu(dqp->q_core.d_blk_softlimit));
1445         xfs_debug(mp, "---- inohlimit =  %Lu (0x%x)",
1446                 be64_to_cpu(dqp->q_core.d_ino_hardlimit),
1447                 (int)be64_to_cpu(dqp->q_core.d_ino_hardlimit));
1448         xfs_debug(mp, "---- inoslimit =  %Lu (0x%x)",
1449                 be64_to_cpu(dqp->q_core.d_ino_softlimit),
1450                 (int)be64_to_cpu(dqp->q_core.d_ino_softlimit));
1451         xfs_debug(mp, "---- bcount  =  %Lu (0x%x)",
1452                 be64_to_cpu(dqp->q_core.d_bcount),
1453                 (int)be64_to_cpu(dqp->q_core.d_bcount));
1454         xfs_debug(mp, "---- icount  =  %Lu (0x%x)",
1455                 be64_to_cpu(dqp->q_core.d_icount),
1456                 (int)be64_to_cpu(dqp->q_core.d_icount));
1457         xfs_debug(mp, "---- btimer  =  %d",
1458                 (int)be32_to_cpu(dqp->q_core.d_btimer));
1459         xfs_debug(mp, "---- itimer  =  %d",
1460                 (int)be32_to_cpu(dqp->q_core.d_itimer));
1461         xfs_debug(mp, "---------------------------");
1462 }
1463 #endif
1464
1465 /*
1466  * Give the buffer a little push if it is incore and
1467  * wait on the flush lock.
1468  */
1469 void
1470 xfs_qm_dqflock_pushbuf_wait(
1471         xfs_dquot_t     *dqp)
1472 {
1473         xfs_mount_t     *mp = dqp->q_mount;
1474         xfs_buf_t       *bp;
1475
1476         /*
1477          * Check to see if the dquot has been flushed delayed
1478          * write.  If so, grab its buffer and send it
1479          * out immediately.  We'll be able to acquire
1480          * the flush lock when the I/O completes.
1481          */
1482         bp = xfs_incore(mp->m_ddev_targp, dqp->q_blkno,
1483                         mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK);
1484         if (!bp)
1485                 goto out_lock;
1486
1487         if (XFS_BUF_ISDELAYWRITE(bp)) {
1488                 if (XFS_BUF_ISPINNED(bp))
1489                         xfs_log_force(mp, 0);
1490                 xfs_buf_delwri_promote(bp);
1491                 wake_up_process(bp->b_target->bt_task);
1492         }
1493         xfs_buf_relse(bp);
1494 out_lock:
1495         xfs_dqflock(dqp);
1496 }