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_dir2.h"
  27 #include "xfs_alloc.h"
  28 #include "xfs_dmapi.h"
  29 #include "xfs_quota.h"
  30 #include "xfs_mount.h"
  31 #include "xfs_bmap_btree.h"
  32 #include "xfs_alloc_btree.h"
  33 #include "xfs_ialloc_btree.h"
  34 #include "xfs_dir2_sf.h"
  35 #include "xfs_attr_sf.h"
  36 #include "xfs_dinode.h"
  37 #include "xfs_inode.h"
  38 #include "xfs_btree.h"
  39 #include "xfs_ialloc.h"
  40 #include "xfs_bmap.h"
  41 #include "xfs_rtalloc.h"
  42 #include "xfs_error.h"
  43 #include "xfs_itable.h"
  44 #include "xfs_rw.h"
  45 #include "xfs_attr.h"
  46 #include "xfs_buf_item.h"
  47 #include "xfs_trans_space.h"
  48 #include "xfs_trans_priv.h"
  49 #include "xfs_qm.h"
  50 #include "xfs_trace.h"
  51
  52
  53 /*
  54    LOCK ORDER
  55
  56    inode lock               (ilock)
  57    dquot hash-chain lock    (hashlock)
  58    xqm dquot freelist lock  (freelistlock
  59    mount's dquot list lock  (mplistlock)
  60    user dquot lock - lock ordering among dquots is based on the uid or gid
  61    group dquot lock - similar to udquots. Between the two dquots, the udquot
  62                       has to be locked first.
  63    pin lock - the dquot lock must be held to take this lock.
  64    flush lock - ditto.
  65 */
  66
  67 STATIC void             xfs_qm_dqflush_done(xfs_buf_t *, xfs_dq_logitem_t *);
  68
  69 #ifdef DEBUG
  70 xfs_buftarg_t *xfs_dqerror_target;
  71 int xfs_do_dqerror;
  72 int xfs_dqreq_num;
  73 int xfs_dqerror_mod = 33;
  74 #endif
  75
  76 static struct lock_class_key xfs_dquot_other_class;
  77
  78 /*
  79  * Allocate and initialize a dquot. We don't always allocate fresh memory;
  80  * we try to reclaim a free dquot if the number of incore dquots are above
  81  * a threshold.
  82  * The only field inside the core that gets initialized at this point
  83  * is the d_id field. The idea is to fill in the entire q_core
  84  * when we read in the on disk dquot.
  85  */
  86 STATIC xfs_dquot_t *
  87 xfs_qm_dqinit(
  88         xfs_mount_t  *mp,
  89         xfs_dqid_t   id,
  90         uint         type)
  91 {
  92         xfs_dquot_t     *dqp;
  93         boolean_t       brandnewdquot;
  94
  95         brandnewdquot = xfs_qm_dqalloc_incore(&dqp);
  96         dqp->dq_flags = type;
  97         dqp->q_core.d_id = cpu_to_be32(id);
  98         dqp->q_mount = mp;
  99
 100         /*
 101          * No need to re-initialize these if this is a reclaimed dquot.
 102          */
 103         if (brandnewdquot) {
 104                 INIT_LIST_HEAD(&dqp->q_freelist);
 105                 mutex_init(&dqp->q_qlock);
 106                 init_waitqueue_head(&dqp->q_pinwait);
 107
 108                 /*
 109                  * Because we want to use a counting completion, complete
 110                  * the flush completion once to allow a single access to
 111                  * the flush completion without blocking.
 112                  */
 113                 init_completion(&dqp->q_flush);
 114                 complete(&dqp->q_flush);
 115
 116                 trace_xfs_dqinit(dqp);
 117         } else {
 118                 /*
 119                  * Only the q_core portion was zeroed in dqreclaim_one().
 120                  * So, we need to reset others.
 121                  */
 122                 dqp->q_nrefs = 0;
 123                 dqp->q_blkno = 0;
 124                 INIT_LIST_HEAD(&dqp->q_mplist);
 125                 INIT_LIST_HEAD(&dqp->q_hashlist);
 126                 dqp->q_bufoffset = 0;
 127                 dqp->q_fileoffset = 0;
 128                 dqp->q_transp = NULL;
 129                 dqp->q_gdquot = NULL;
 130                 dqp->q_res_bcount = 0;
 131                 dqp->q_res_icount = 0;
 132                 dqp->q_res_rtbcount = 0;
 133                 atomic_set(&dqp->q_pincount, 0);
 134                 dqp->q_hash = NULL;
 135                 ASSERT(list_empty(&dqp->q_freelist));
 136
 137                 trace_xfs_dqreuse(dqp);
 138         }
 139
 140         /*
 141          * In either case we need to make sure group quotas have a different
 142          * lock class than user quotas, to make sure lockdep knows we can
 143          * locks of one of each at the same time.
 144          */
 145         if (!(type & XFS_DQ_USER))
 146                 lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
 147
 148         /*
 149          * log item gets initialized later
 150          */
 151         return (dqp);
 152 }
 153
 154 /*
 155  * This is called to free all the memory associated with a dquot
 156  */
 157 void
 158 xfs_qm_dqdestroy(
 159         xfs_dquot_t     *dqp)
 160 {
 161         ASSERT(list_empty(&dqp->q_freelist));
 162
 163         mutex_destroy(&dqp->q_qlock);
 164         sv_destroy(&dqp->q_pinwait);
 165         kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
 166
 167         atomic_dec(&xfs_Gqm->qm_totaldquots);
 168 }
 169
 170 /*
 171  * This is what a 'fresh' dquot inside a dquot chunk looks like on disk.
 172  */
 173 STATIC void
 174 xfs_qm_dqinit_core(
 175         xfs_dqid_t      id,
 176         uint            type,
 177         xfs_dqblk_t     *d)
 178 {
 179         /*
 180          * Caller has zero'd the entire dquot 'chunk' already.
 181          */
 182         d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 183         d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 184         d->dd_diskdq.d_id = cpu_to_be32(id);
 185         d->dd_diskdq.d_flags = type;
 186 }
 187
 188 /*
 189  * If default limits are in force, push them into the dquot now.
 190  * We overwrite the dquot limits only if they are zero and this
 191  * is not the root dquot.
 192  */
 193 void
 194 xfs_qm_adjust_dqlimits(
 195         xfs_mount_t             *mp,
 196         xfs_disk_dquot_t        *d)
 197 {
 198         xfs_quotainfo_t         *q = mp->m_quotainfo;
 199
 200         ASSERT(d->d_id);
 201
 202         if (q->qi_bsoftlimit && !d->d_blk_softlimit)
 203                 d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
 204         if (q->qi_bhardlimit && !d->d_blk_hardlimit)
 205                 d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
 206         if (q->qi_isoftlimit && !d->d_ino_softlimit)
 207                 d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
 208         if (q->qi_ihardlimit && !d->d_ino_hardlimit)
 209                 d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
 210         if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
 211                 d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
 212         if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
 213                 d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
 214 }
 215
 216 /*
 217  * Check the limits and timers of a dquot and start or reset timers
 218  * if necessary.
 219  * This gets called even when quota enforcement is OFF, which makes our
 220  * life a little less complicated. (We just don't reject any quota
 221  * reservations in that case, when enforcement is off).
 222  * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
 223  * enforcement's off.
 224  * In contrast, warnings are a little different in that they don't
 225  * 'automatically' get started when limits get exceeded.  They do
 226  * get reset to zero, however, when we find the count to be under
 227  * the soft limit (they are only ever set non-zero via userspace).
 228  */
 229 void
 230 xfs_qm_adjust_dqtimers(
 231         xfs_mount_t             *mp,
 232         xfs_disk_dquot_t        *d)
 233 {
 234         ASSERT(d->d_id);
 235
 236 #ifdef QUOTADEBUG
 237         if (d->d_blk_hardlimit)
 238                 ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
 239                        be64_to_cpu(d->d_blk_hardlimit));
 240         if (d->d_ino_hardlimit)
 241                 ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
 242                        be64_to_cpu(d->d_ino_hardlimit));
 243         if (d->d_rtb_hardlimit)
 244                 ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
 245                        be64_to_cpu(d->d_rtb_hardlimit));
 246 #endif
 247         if (!d->d_btimer) {
 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 = cpu_to_be32(get_seconds() +
 255                                         XFS_QI_BTIMELIMIT(mp));
 256                 } else {
 257                         d->d_bwarns = 0;
 258                 }
 259         } else {
 260                 if ((!d->d_blk_softlimit ||
 261                      (be64_to_cpu(d->d_bcount) <
 262                       be64_to_cpu(d->d_blk_softlimit))) &&
 263                     (!d->d_blk_hardlimit ||
 264                     (be64_to_cpu(d->d_bcount) <
 265                      be64_to_cpu(d->d_blk_hardlimit)))) {
 266                         d->d_btimer = 0;
 267                 }
 268         }
 269
 270         if (!d->d_itimer) {
 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 = cpu_to_be32(get_seconds() +
 278                                         XFS_QI_ITIMELIMIT(mp));
 279                 } else {
 280                         d->d_iwarns = 0;
 281                 }
 282         } else {
 283                 if ((!d->d_ino_softlimit ||
 284                      (be64_to_cpu(d->d_icount) <
 285                       be64_to_cpu(d->d_ino_softlimit)))  &&
 286                     (!d->d_ino_hardlimit ||
 287                      (be64_to_cpu(d->d_icount) <
 288                       be64_to_cpu(d->d_ino_hardlimit)))) {
 289                         d->d_itimer = 0;
 290                 }
 291         }
 292
 293         if (!d->d_rtbtimer) {
 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 = cpu_to_be32(get_seconds() +
 301                                         XFS_QI_RTBTIMELIMIT(mp));
 302                 } else {
 303                         d->d_rtbwarns = 0;
 304                 }
 305         } else {
 306                 if ((!d->d_rtb_softlimit ||
 307                      (be64_to_cpu(d->d_rtbcount) <
 308                       be64_to_cpu(d->d_rtb_softlimit))) &&
 309                     (!d->d_rtb_hardlimit ||
 310                      (be64_to_cpu(d->d_rtbcount) <
 311                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 312                         d->d_rtbtimer = 0;
 313                 }
 314         }
 315 }
 316
 317 /*
 318  * initialize a buffer full of dquots and log the whole thing
 319  */
 320 STATIC void
 321 xfs_qm_init_dquot_blk(
 322         xfs_trans_t     *tp,
 323         xfs_mount_t     *mp,
 324         xfs_dqid_t      id,
 325         uint            type,
 326         xfs_buf_t       *bp)
 327 {
 328         xfs_dqblk_t     *d;
 329         int             curid, i;
 330
 331         ASSERT(tp);
 332         ASSERT(XFS_BUF_ISBUSY(bp));
 333         ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 334
 335         d = (xfs_dqblk_t *)XFS_BUF_PTR(bp);
 336
 337         /*
 338          * ID of the first dquot in the block - id's are zero based.
 339          */
 340         curid = id - (id % XFS_QM_DQPERBLK(mp));
 341         ASSERT(curid >= 0);
 342         memset(d, 0, BBTOB(XFS_QI_DQCHUNKLEN(mp)));
 343         for (i = 0; i < XFS_QM_DQPERBLK(mp); i++, d++, curid++)
 344                 xfs_qm_dqinit_core(curid, type, d);
 345         xfs_trans_dquot_buf(tp, bp,
 346                             (type & XFS_DQ_USER ? XFS_BLI_UDQUOT_BUF :
 347                             ((type & XFS_DQ_PROJ) ? XFS_BLI_PDQUOT_BUF :
 348                              XFS_BLI_GDQUOT_BUF)));
 349         xfs_trans_log_buf(tp, bp, 0, BBTOB(XFS_QI_DQCHUNKLEN(mp)) - 1);
 350 }
 351
 352
 353
 354 /*
 355  * Allocate a block and fill it with dquots.
 356  * This is called when the bmapi finds a hole.
 357  */
 358 STATIC int
 359 xfs_qm_dqalloc(
 360         xfs_trans_t     **tpp,
 361         xfs_mount_t     *mp,
 362         xfs_dquot_t     *dqp,
 363         xfs_inode_t     *quotip,
 364         xfs_fileoff_t   offset_fsb,
 365         xfs_buf_t       **O_bpp)
 366 {
 367         xfs_fsblock_t   firstblock;
 368         xfs_bmap_free_t flist;
 369         xfs_bmbt_irec_t map;
 370         int             nmaps, error, committed;
 371         xfs_buf_t       *bp;
 372         xfs_trans_t     *tp = *tpp;
 373
 374         ASSERT(tp != NULL);
 375
 376         trace_xfs_dqalloc(dqp);
 377
 378         /*
 379          * Initialize the bmap freelist prior to calling bmapi code.
 380          */
 381         xfs_bmap_init(&flist, &firstblock);
 382         xfs_ilock(quotip, XFS_ILOCK_EXCL);
 383         /*
 384          * Return if this type of quotas is turned off while we didn't
 385          * have an inode lock
 386          */
 387         if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
 388                 xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 389                 return (ESRCH);
 390         }
 391
 392         /*
 393          * xfs_trans_commit normally decrements the vnode ref count
 394          * when it unlocks the inode. Since we want to keep the quota
 395          * inode around, we bump the vnode ref count now.
 396          */
 397         IHOLD(quotip);
 398
 399         xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
 400         nmaps = 1;
 401         if ((error = xfs_bmapi(tp, quotip,
 402                               offset_fsb, XFS_DQUOT_CLUSTER_SIZE_FSB,
 403                               XFS_BMAPI_METADATA | XFS_BMAPI_WRITE,
 404                               &firstblock,
 405                               XFS_QM_DQALLOC_SPACE_RES(mp),
 406                               &map, &nmaps, &flist, NULL))) {
 407                 goto error0;
 408         }
 409         ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
 410         ASSERT(nmaps == 1);
 411         ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 412                (map.br_startblock != HOLESTARTBLOCK));
 413
 414         /*
 415          * Keep track of the blkno to save a lookup later
 416          */
 417         dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 418
 419         /* now we can just get the buffer (there's nothing to read yet) */
 420         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
 421                                dqp->q_blkno,
 422                                XFS_QI_DQCHUNKLEN(mp),
 423                                0);
 424         if (!bp || (error = XFS_BUF_GETERROR(bp)))
 425                 goto error1;
 426         /*
 427          * Make a chunk of dquots out of this buffer and log
 428          * the entire thing.
 429          */
 430         xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
 431                               dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
 432
 433         /*
 434          * xfs_bmap_finish() may commit the current transaction and
 435          * start a second transaction if the freelist is not empty.
 436          *
 437          * Since we still want to modify this buffer, we need to
 438          * ensure that the buffer is not released on commit of
 439          * the first transaction and ensure the buffer is added to the
 440          * second transaction.
 441          *
 442          * If there is only one transaction then don't stop the buffer
 443          * from being released when it commits later on.
 444          */
 445
 446         xfs_trans_bhold(tp, bp);
 447
 448         if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
 449                 goto error1;
 450         }
 451
 452         if (committed) {
 453                 tp = *tpp;
 454                 xfs_trans_bjoin(tp, bp);
 455         } else {
 456                 xfs_trans_bhold_release(tp, bp);
 457         }
 458
 459         *O_bpp = bp;
 460         return 0;
 461
 462       error1:
 463         xfs_bmap_cancel(&flist);
 464       error0:
 465         xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 466
 467         return (error);
 468 }
 469
 470 /*
 471  * Maps a dquot to the buffer containing its on-disk version.
 472  * This returns a ptr to the buffer containing the on-disk dquot
 473  * in the bpp param, and a ptr to the on-disk dquot within that buffer
 474  */
 475 STATIC int
 476 xfs_qm_dqtobp(
 477         xfs_trans_t             **tpp,
 478         xfs_dquot_t             *dqp,
 479         xfs_disk_dquot_t        **O_ddpp,
 480         xfs_buf_t               **O_bpp,
 481         uint                    flags)
 482 {
 483         xfs_bmbt_irec_t map;
 484         int             nmaps, error;
 485         xfs_buf_t       *bp;
 486         xfs_inode_t     *quotip;
 487         xfs_mount_t     *mp;
 488         xfs_disk_dquot_t *ddq;
 489         xfs_dqid_t      id;
 490         boolean_t       newdquot;
 491         xfs_trans_t     *tp = (tpp ? *tpp : NULL);
 492
 493         mp = dqp->q_mount;
 494         id = be32_to_cpu(dqp->q_core.d_id);
 495         nmaps = 1;
 496         newdquot = B_FALSE;
 497
 498         /*
 499          * If we don't know where the dquot lives, find out.
 500          */
 501         if (dqp->q_blkno == (xfs_daddr_t) 0) {
 502                 /* We use the id as an index */
 503                 dqp->q_fileoffset = (xfs_fileoff_t)id / XFS_QM_DQPERBLK(mp);
 504                 nmaps = 1;
 505                 quotip = XFS_DQ_TO_QIP(dqp);
 506                 xfs_ilock(quotip, XFS_ILOCK_SHARED);
 507                 /*
 508                  * Return if this type of quotas is turned off while we didn't
 509                  * have an inode lock
 510                  */
 511                 if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
 512                         xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 513                         return (ESRCH);
 514                 }
 515                 /*
 516                  * Find the block map; no allocations yet
 517                  */
 518                 error = xfs_bmapi(NULL, quotip, dqp->q_fileoffset,
 519                                   XFS_DQUOT_CLUSTER_SIZE_FSB,
 520                                   XFS_BMAPI_METADATA,
 521                                   NULL, 0, &map, &nmaps, NULL, NULL);
 522
 523                 xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 524                 if (error)
 525                         return (error);
 526                 ASSERT(nmaps == 1);
 527                 ASSERT(map.br_blockcount == 1);
 528
 529                 /*
 530                  * offset of dquot in the (fixed sized) dquot chunk.
 531                  */
 532                 dqp->q_bufoffset = (id % XFS_QM_DQPERBLK(mp)) *
 533                         sizeof(xfs_dqblk_t);
 534                 if (map.br_startblock == HOLESTARTBLOCK) {
 535                         /*
 536                          * We don't allocate unless we're asked to
 537                          */
 538                         if (!(flags & XFS_QMOPT_DQALLOC))
 539                                 return (ENOENT);
 540
 541                         ASSERT(tp);
 542                         if ((error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
 543                                                 dqp->q_fileoffset, &bp)))
 544                                 return (error);
 545                         tp = *tpp;
 546                         newdquot = B_TRUE;
 547                 } else {
 548                         /*
 549                          * store the blkno etc so that we don't have to do the
 550                          * mapping all the time
 551                          */
 552                         dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 553                 }
 554         }
 555         ASSERT(dqp->q_blkno != DELAYSTARTBLOCK);
 556         ASSERT(dqp->q_blkno != HOLESTARTBLOCK);
 557
 558         /*
 559          * Read in the buffer, unless we've just done the allocation
 560          * (in which case we already have the buf).
 561          */
 562         if (! newdquot) {
 563                 trace_xfs_dqtobp_read(dqp);
 564
 565                 if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 566                                                dqp->q_blkno,
 567                                                XFS_QI_DQCHUNKLEN(mp),
 568                                                0, &bp))) {
 569                         return (error);
 570                 }
 571                 if (error || !bp)
 572                         return XFS_ERROR(error);
 573         }
 574         ASSERT(XFS_BUF_ISBUSY(bp));
 575         ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 576
 577         /*
 578          * calculate the location of the dquot inside the buffer.
 579          */
 580         ddq = (xfs_disk_dquot_t *)((char *)XFS_BUF_PTR(bp) + dqp->q_bufoffset);
 581
 582         /*
 583          * A simple sanity check in case we got a corrupted dquot...
 584          */
 585         if (xfs_qm_dqcheck(ddq, id, dqp->dq_flags & XFS_DQ_ALLTYPES,
 586                            flags & (XFS_QMOPT_DQREPAIR|XFS_QMOPT_DOWARN),
 587                            "dqtobp")) {
 588                 if (!(flags & XFS_QMOPT_DQREPAIR)) {
 589                         xfs_trans_brelse(tp, bp);
 590                         return XFS_ERROR(EIO);
 591                 }
 592                 XFS_BUF_BUSY(bp); /* We dirtied this */
 593         }
 594
 595         *O_bpp = bp;
 596         *O_ddpp = ddq;
 597
 598         return (0);
 599 }
 600
 601
 602 /*
 603  * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
 604  * and release the buffer immediately.
 605  *
 606  */
 607 /* ARGSUSED */
 608 STATIC int
 609 xfs_qm_dqread(
 610         xfs_trans_t     **tpp,
 611         xfs_dqid_t      id,
 612         xfs_dquot_t     *dqp,   /* dquot to get filled in */
 613         uint            flags)
 614 {
 615         xfs_disk_dquot_t *ddqp;
 616         xfs_buf_t        *bp;
 617         int              error;
 618         xfs_trans_t      *tp;
 619
 620         ASSERT(tpp);
 621
 622         trace_xfs_dqread(dqp);
 623
 624         /*
 625          * get a pointer to the on-disk dquot and the buffer containing it
 626          * dqp already knows its own type (GROUP/USER).
 627          */
 628         if ((error = xfs_qm_dqtobp(tpp, dqp, &ddqp, &bp, flags))) {
 629                 return (error);
 630         }
 631         tp = *tpp;
 632
 633         /* copy everything from disk dquot to the incore dquot */
 634         memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
 635         ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);
 636         xfs_qm_dquot_logitem_init(dqp);
 637
 638         /*
 639          * Reservation counters are defined as reservation plus current usage
 640          * to avoid having to add everytime.
 641          */
 642         dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
 643         dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
 644         dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
 645
 646         /* Mark the buf so that this will stay incore a little longer */
 647         XFS_BUF_SET_VTYPE_REF(bp, B_FS_DQUOT, XFS_DQUOT_REF);
 648
 649         /*
 650          * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
 651          * So we need to release with xfs_trans_brelse().
 652          * The strategy here is identical to that of inodes; we lock
 653          * the dquot in xfs_qm_dqget() before making it accessible to
 654          * others. This is because dquots, like inodes, need a good level of
 655          * concurrency, and we don't want to take locks on the entire buffers
 656          * for dquot accesses.
 657          * Note also that the dquot buffer may even be dirty at this point, if
 658          * this particular dquot was repaired. We still aren't afraid to
 659          * brelse it because we have the changes incore.
 660          */
 661         ASSERT(XFS_BUF_ISBUSY(bp));
 662         ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 663         xfs_trans_brelse(tp, bp);
 664
 665         return (error);
 666 }
 667
 668
 669 /*
 670  * allocate an incore dquot from the kernel heap,
 671  * and fill its core with quota information kept on disk.
 672  * If XFS_QMOPT_DQALLOC is set, it'll allocate a dquot on disk
 673  * if it wasn't already allocated.
 674  */
 675 STATIC int
 676 xfs_qm_idtodq(
 677         xfs_mount_t     *mp,
 678         xfs_dqid_t      id,      /* gid or uid, depending on type */
 679         uint            type,    /* UDQUOT or GDQUOT */
 680         uint            flags,   /* DQALLOC, DQREPAIR */
 681         xfs_dquot_t     **O_dqpp)/* OUT : incore dquot, not locked */
 682 {
 683         xfs_dquot_t     *dqp;
 684         int             error;
 685         xfs_trans_t     *tp;
 686         int             cancelflags=0;
 687
 688         dqp = xfs_qm_dqinit(mp, id, type);
 689         tp = NULL;
 690         if (flags & XFS_QMOPT_DQALLOC) {
 691                 tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
 692                 if ((error = xfs_trans_reserve(tp,
 693                                        XFS_QM_DQALLOC_SPACE_RES(mp),
 694                                        XFS_WRITE_LOG_RES(mp) +
 695                                               BBTOB(XFS_QI_DQCHUNKLEN(mp)) - 1 +
 696                                               128,
 697                                        0,
 698                                        XFS_TRANS_PERM_LOG_RES,
 699                                        XFS_WRITE_LOG_COUNT))) {
 700                         cancelflags = 0;
 701                         goto error0;
 702                 }
 703                 cancelflags = XFS_TRANS_RELEASE_LOG_RES;
 704         }
 705
 706         /*
 707          * Read it from disk; xfs_dqread() takes care of
 708          * all the necessary initialization of dquot's fields (locks, etc)
 709          */
 710         if ((error = xfs_qm_dqread(&tp, id, dqp, flags))) {
 711                 /*
 712                  * This can happen if quotas got turned off (ESRCH),
 713                  * or if the dquot didn't exist on disk and we ask to
 714                  * allocate (ENOENT).
 715                  */
 716                 trace_xfs_dqread_fail(dqp);
 717                 cancelflags |= XFS_TRANS_ABORT;
 718                 goto error0;
 719         }
 720         if (tp) {
 721                 if ((error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES)))
 722                         goto error1;
 723         }
 724
 725         *O_dqpp = dqp;
 726         return (0);
 727
 728  error0:
 729         ASSERT(error);
 730         if (tp)
 731                 xfs_trans_cancel(tp, cancelflags);
 732  error1:
 733         xfs_qm_dqdestroy(dqp);
 734         *O_dqpp = NULL;
 735         return (error);
 736 }
 737
 738 /*
 739  * Lookup a dquot in the incore dquot hashtable. We keep two separate
 740  * hashtables for user and group dquots; and, these are global tables
 741  * inside the XQM, not per-filesystem tables.
 742  * The hash chain must be locked by caller, and it is left locked
 743  * on return. Returning dquot is locked.
 744  */
 745 STATIC int
 746 xfs_qm_dqlookup(
 747         xfs_mount_t             *mp,
 748         xfs_dqid_t              id,
 749         xfs_dqhash_t            *qh,
 750         xfs_dquot_t             **O_dqpp)
 751 {
 752         xfs_dquot_t             *dqp;
 753         uint                    flist_locked;
 754
 755         ASSERT(mutex_is_locked(&qh->qh_lock));
 756
 757         flist_locked = B_FALSE;
 758
 759         /*
 760          * Traverse the hashchain looking for a match
 761          */
 762         list_for_each_entry(dqp, &qh->qh_list, q_hashlist) {
 763                 /*
 764                  * We already have the hashlock. We don't need the
 765                  * dqlock to look at the id field of the dquot, since the
 766                  * id can't be modified without the hashlock anyway.
 767                  */
 768                 if (be32_to_cpu(dqp->q_core.d_id) == id && dqp->q_mount == mp) {
 769                         trace_xfs_dqlookup_found(dqp);
 770
 771                         /*
 772                          * All in core dquots must be on the dqlist of mp
 773                          */
 774                         ASSERT(!list_empty(&dqp->q_mplist));
 775
 776                         xfs_dqlock(dqp);
 777                         if (dqp->q_nrefs == 0) {
 778                                 ASSERT(!list_empty(&dqp->q_freelist));
 779                                 if (!mutex_trylock(&xfs_Gqm->qm_dqfrlist_lock)) {
 780                                         trace_xfs_dqlookup_want(dqp);
 781
 782                                         /*
 783                                          * We may have raced with dqreclaim_one()
 784                                          * (and lost). So, flag that we don't
 785                                          * want the dquot to be reclaimed.
 786                                          */
 787                                         dqp->dq_flags |= XFS_DQ_WANT;
 788                                         xfs_dqunlock(dqp);
 789                                         mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
 790                                         xfs_dqlock(dqp);
 791                                         dqp->dq_flags &= ~(XFS_DQ_WANT);
 792                                 }
 793                                 flist_locked = B_TRUE;
 794                         }
 795
 796                         /*
 797                          * id couldn't have changed; we had the hashlock all
 798                          * along
 799                          */
 800                         ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);
 801
 802                         if (flist_locked) {
 803                                 if (dqp->q_nrefs != 0) {
 804                                         mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
 805                                         flist_locked = B_FALSE;
 806                                 } else {
 807                                         /* take it off the freelist */
 808                                         trace_xfs_dqlookup_freelist(dqp);
 809                                         list_del_init(&dqp->q_freelist);
 810                                         xfs_Gqm->qm_dqfrlist_cnt--;
 811                                 }
 812                         }
 813
 814                         XFS_DQHOLD(dqp);
 815
 816                         if (flist_locked)
 817                                 mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
 818                         /*
 819                          * move the dquot to the front of the hashchain
 820                          */
 821                         ASSERT(mutex_is_locked(&qh->qh_lock));
 822                         list_move(&dqp->q_hashlist, &qh->qh_list);
 823                         trace_xfs_dqlookup_done(dqp);
 824                         *O_dqpp = dqp;
 825                         return 0;
 826                 }
 827         }
 828
 829         *O_dqpp = NULL;
 830         ASSERT(mutex_is_locked(&qh->qh_lock));
 831         return (1);
 832 }
 833
 834 /*
 835  * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
 836  * a locked dquot, doing an allocation (if requested) as needed.
 837  * When both an inode and an id are given, the inode's id takes precedence.
 838  * That is, if the id changes while we don't hold the ilock inside this
 839  * function, the new dquot is returned, not necessarily the one requested
 840  * in the id argument.
 841  */
 842 int
 843 xfs_qm_dqget(
 844         xfs_mount_t     *mp,
 845         xfs_inode_t     *ip,      /* locked inode (optional) */
 846         xfs_dqid_t      id,       /* uid/projid/gid depending on type */
 847         uint            type,     /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
 848         uint            flags,    /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
 849         xfs_dquot_t     **O_dqpp) /* OUT : locked incore dquot */
 850 {
 851         xfs_dquot_t     *dqp;
 852         xfs_dqhash_t    *h;
 853         uint            version;
 854         int             error;
 855
 856         ASSERT(XFS_IS_QUOTA_RUNNING(mp));
 857         if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
 858             (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
 859             (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
 860                 return (ESRCH);
 861         }
 862         h = XFS_DQ_HASH(mp, id, type);
 863
 864 #ifdef DEBUG
 865         if (xfs_do_dqerror) {
 866                 if ((xfs_dqerror_target == mp->m_ddev_targp) &&
 867                     (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
 868                         cmn_err(CE_DEBUG, "Returning error in dqget");
 869                         return (EIO);
 870                 }
 871         }
 872 #endif
 873
 874  again:
 875
 876 #ifdef DEBUG
 877         ASSERT(type == XFS_DQ_USER ||
 878                type == XFS_DQ_PROJ ||
 879                type == XFS_DQ_GROUP);
 880         if (ip) {
 881                 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 882                 if (type == XFS_DQ_USER)
 883                         ASSERT(ip->i_udquot == NULL);
 884                 else
 885                         ASSERT(ip->i_gdquot == NULL);
 886         }
 887 #endif
 888         mutex_lock(&h->qh_lock);
 889
 890         /*
 891          * Look in the cache (hashtable).
 892          * The chain is kept locked during lookup.
 893          */
 894         if (xfs_qm_dqlookup(mp, id, h, O_dqpp) == 0) {
 895                 XQM_STATS_INC(xqmstats.xs_qm_dqcachehits);
 896                 /*
 897                  * The dquot was found, moved to the front of the chain,
 898                  * taken off the freelist if it was on it, and locked
 899                  * at this point. Just unlock the hashchain and return.
 900                  */
 901                 ASSERT(*O_dqpp);
 902                 ASSERT(XFS_DQ_IS_LOCKED(*O_dqpp));
 903                 mutex_unlock(&h->qh_lock);
 904                 trace_xfs_dqget_hit(*O_dqpp);
 905                 return (0);     /* success */
 906         }
 907         XQM_STATS_INC(xqmstats.xs_qm_dqcachemisses);
 908
 909         /*
 910          * Dquot cache miss. We don't want to keep the inode lock across
 911          * a (potential) disk read. Also we don't want to deal with the lock
 912          * ordering between quotainode and this inode. OTOH, dropping the inode
 913          * lock here means dealing with a chown that can happen before
 914          * we re-acquire the lock.
 915          */
 916         if (ip)
 917                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 918         /*
 919          * Save the hashchain version stamp, and unlock the chain, so that
 920          * we don't keep the lock across a disk read
 921          */
 922         version = h->qh_version;
 923         mutex_unlock(&h->qh_lock);
 924
 925         /*
 926          * Allocate the dquot on the kernel heap, and read the ondisk
 927          * portion off the disk. Also, do all the necessary initialization
 928          * This can return ENOENT if dquot didn't exist on disk and we didn't
 929          * ask it to allocate; ESRCH if quotas got turned off suddenly.
 930          */
 931         if ((error = xfs_qm_idtodq(mp, id, type,
 932                                   flags & (XFS_QMOPT_DQALLOC|XFS_QMOPT_DQREPAIR|
 933                                            XFS_QMOPT_DOWARN),
 934                                   &dqp))) {
 935                 if (ip)
 936                         xfs_ilock(ip, XFS_ILOCK_EXCL);
 937                 return (error);
 938         }
 939
 940         /*
 941          * See if this is mount code calling to look at the overall quota limits
 942          * which are stored in the id == 0 user or group's dquot.
 943          * Since we may not have done a quotacheck by this point, just return
 944          * the dquot without attaching it to any hashtables, lists, etc, or even
 945          * taking a reference.
 946          * The caller must dqdestroy this once done.
 947          */
 948         if (flags & XFS_QMOPT_DQSUSER) {
 949                 ASSERT(id == 0);
 950                 ASSERT(! ip);
 951                 goto dqret;
 952         }
 953
 954         /*
 955          * Dquot lock comes after hashlock in the lock ordering
 956          */
 957         if (ip) {
 958                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 959                 if (! XFS_IS_DQTYPE_ON(mp, type)) {
 960                         /* inode stays locked on return */
 961                         xfs_qm_dqdestroy(dqp);
 962                         return XFS_ERROR(ESRCH);
 963                 }
 964                 /*
 965                  * A dquot could be attached to this inode by now, since
 966                  * we had dropped the ilock.
 967                  */
 968                 if (type == XFS_DQ_USER) {
 969                         if (ip->i_udquot) {
 970                                 xfs_qm_dqdestroy(dqp);
 971                                 dqp = ip->i_udquot;
 972                                 xfs_dqlock(dqp);
 973                                 goto dqret;
 974                         }
 975                 } else {
 976                         if (ip->i_gdquot) {
 977                                 xfs_qm_dqdestroy(dqp);
 978                                 dqp = ip->i_gdquot;
 979                                 xfs_dqlock(dqp);
 980                                 goto dqret;
 981                         }
 982                 }
 983         }
 984
 985         /*
 986          * Hashlock comes after ilock in lock order
 987          */
 988         mutex_lock(&h->qh_lock);
 989         if (version != h->qh_version) {
 990                 xfs_dquot_t *tmpdqp;
 991                 /*
 992                  * Now, see if somebody else put the dquot in the
 993                  * hashtable before us. This can happen because we didn't
 994                  * keep the hashchain lock. We don't have to worry about
 995                  * lock order between the two dquots here since dqp isn't
 996                  * on any findable lists yet.
 997                  */
 998                 if (xfs_qm_dqlookup(mp, id, h, &tmpdqp) == 0) {
 999                         /*
1000                          * Duplicate found. Just throw away the new dquot
1001                          * and start over.
1002                          */
1003                         xfs_qm_dqput(tmpdqp);
1004                         mutex_unlock(&h->qh_lock);
1005                         xfs_qm_dqdestroy(dqp);
1006                         XQM_STATS_INC(xqmstats.xs_qm_dquot_dups);
1007                         goto again;
1008                 }
1009         }
1010
1011         /*
1012          * Put the dquot at the beginning of the hash-chain and mp's list
1013          * LOCK ORDER: hashlock, freelistlock, mplistlock, udqlock, gdqlock ..
1014          */
1015         ASSERT(mutex_is_locked(&h->qh_lock));
1016         dqp->q_hash = h;
1017         list_add(&dqp->q_hashlist, &h->qh_list);
1018         h->qh_version++;
1019
1020         /*
1021          * Attach this dquot to this filesystem's list of all dquots,
1022          * kept inside the mount structure in m_quotainfo field
1023          */
1024         mutex_lock(&mp->m_quotainfo->qi_dqlist_lock);
1025
1026         /*
1027          * We return a locked dquot to the caller, with a reference taken
1028          */
1029         xfs_dqlock(dqp);
1030         dqp->q_nrefs = 1;
1031
1032         list_add(&dqp->q_mplist, &mp->m_quotainfo->qi_dqlist);
1033         mp->m_quotainfo->qi_dquots++;
1034         mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
1035         mutex_unlock(&h->qh_lock);
1036  dqret:
1037         ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
1038         trace_xfs_dqget_miss(dqp);
1039         *O_dqpp = dqp;
1040         return (0);
1041 }
1042
1043
1044 /*
1045  * Release a reference to the dquot (decrement ref-count)
1046  * and unlock it. If there is a group quota attached to this
1047  * dquot, carefully release that too without tripping over
1048  * deadlocks'n'stuff.
1049  */
1050 void
1051 xfs_qm_dqput(
1052         xfs_dquot_t     *dqp)
1053 {
1054         xfs_dquot_t     *gdqp;
1055
1056         ASSERT(dqp->q_nrefs > 0);
1057         ASSERT(XFS_DQ_IS_LOCKED(dqp));
1058
1059         trace_xfs_dqput(dqp);
1060
1061         if (dqp->q_nrefs != 1) {
1062                 dqp->q_nrefs--;
1063                 xfs_dqunlock(dqp);
1064                 return;
1065         }
1066
1067         /*
1068          * drop the dqlock and acquire the freelist and dqlock
1069          * in the right order; but try to get it out-of-order first
1070          */
1071         if (!mutex_trylock(&xfs_Gqm->qm_dqfrlist_lock)) {
1072                 trace_xfs_dqput_wait(dqp);
1073                 xfs_dqunlock(dqp);
1074                 mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
1075                 xfs_dqlock(dqp);
1076         }
1077
1078         while (1) {
1079                 gdqp = NULL;
1080
1081                 /* We can't depend on nrefs being == 1 here */
1082                 if (--dqp->q_nrefs == 0) {
1083                         trace_xfs_dqput_free(dqp);
1084
1085                         list_add_tail(&dqp->q_freelist, &xfs_Gqm->qm_dqfrlist);
1086                         xfs_Gqm->qm_dqfrlist_cnt++;
1087
1088                         /*
1089                          * If we just added a udquot to the freelist, then
1090                          * we want to release the gdquot reference that
1091                          * it (probably) has. Otherwise it'll keep the
1092                          * gdquot from getting reclaimed.
1093                          */
1094                         if ((gdqp = dqp->q_gdquot)) {
1095                                 /*
1096                                  * Avoid a recursive dqput call
1097                                  */
1098                                 xfs_dqlock(gdqp);
1099                                 dqp->q_gdquot = NULL;
1100                         }
1101                 }
1102                 xfs_dqunlock(dqp);
1103
1104                 /*
1105                  * If we had a group quota inside the user quota as a hint,
1106                  * release it now.
1107                  */
1108                 if (! gdqp)
1109                         break;
1110                 dqp = gdqp;
1111         }
1112         mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
1113 }
1114
1115 /*
1116  * Release a dquot. Flush it if dirty, then dqput() it.
1117  * dquot must not be locked.
1118  */
1119 void
1120 xfs_qm_dqrele(
1121         xfs_dquot_t     *dqp)
1122 {
1123         if (!dqp)
1124                 return;
1125
1126         trace_xfs_dqrele(dqp);
1127
1128         xfs_dqlock(dqp);
1129         /*
1130          * We don't care to flush it if the dquot is dirty here.
1131          * That will create stutters that we want to avoid.
1132          * Instead we do a delayed write when we try to reclaim
1133          * a dirty dquot. Also xfs_sync will take part of the burden...
1134          */
1135         xfs_qm_dqput(dqp);
1136 }
1137
1138
1139 /*
1140  * Write a modified dquot to disk.
1141  * The dquot must be locked and the flush lock too taken by caller.
1142  * The flush lock will not be unlocked until the dquot reaches the disk,
1143  * but the dquot is free to be unlocked and modified by the caller
1144  * in the interim. Dquot is still locked on return. This behavior is
1145  * identical to that of inodes.
1146  */
1147 int
1148 xfs_qm_dqflush(
1149         xfs_dquot_t             *dqp,
1150         uint                    flags)
1151 {
1152         xfs_mount_t             *mp;
1153         xfs_buf_t               *bp;
1154         xfs_disk_dquot_t        *ddqp;
1155         int                     error;
1156
1157         ASSERT(XFS_DQ_IS_LOCKED(dqp));
1158         ASSERT(!completion_done(&dqp->q_flush));
1159         trace_xfs_dqflush(dqp);
1160
1161         /*
1162          * If not dirty, or it's pinned and we are not supposed to
1163          * block, nada.
1164          */
1165         if (!XFS_DQ_IS_DIRTY(dqp) ||
1166             (!(flags & SYNC_WAIT) && atomic_read(&dqp->q_pincount) > 0)) {
1167                 xfs_dqfunlock(dqp);
1168                 return 0;
1169         }
1170         xfs_qm_dqunpin_wait(dqp);
1171
1172         /*
1173          * This may have been unpinned because the filesystem is shutting
1174          * down forcibly. If that's the case we must not write this dquot
1175          * to disk, because the log record didn't make it to disk!
1176          */
1177         if (XFS_FORCED_SHUTDOWN(dqp->q_mount)) {
1178                 dqp->dq_flags &= ~(XFS_DQ_DIRTY);
1179                 xfs_dqfunlock(dqp);
1180                 return XFS_ERROR(EIO);
1181         }
1182
1183         /*
1184          * Get the buffer containing the on-disk dquot
1185          * We don't need a transaction envelope because we know that the
1186          * the ondisk-dquot has already been allocated for.
1187          */
1188         if ((error = xfs_qm_dqtobp(NULL, dqp, &ddqp, &bp, XFS_QMOPT_DOWARN))) {
1189                 ASSERT(error != ENOENT);
1190                 /*
1191                  * Quotas could have gotten turned off (ESRCH)
1192                  */
1193                 xfs_dqfunlock(dqp);
1194                 return (error);
1195         }
1196
1197         if (xfs_qm_dqcheck(&dqp->q_core, be32_to_cpu(ddqp->d_id),
1198                            0, XFS_QMOPT_DOWARN, "dqflush (incore copy)")) {
1199                 xfs_force_shutdown(dqp->q_mount, SHUTDOWN_CORRUPT_INCORE);
1200                 return XFS_ERROR(EIO);
1201         }
1202
1203         /* This is the only portion of data that needs to persist */
1204         memcpy(ddqp, &(dqp->q_core), sizeof(xfs_disk_dquot_t));
1205
1206         /*
1207          * Clear the dirty field and remember the flush lsn for later use.
1208          */
1209         dqp->dq_flags &= ~(XFS_DQ_DIRTY);
1210         mp = dqp->q_mount;
1211
1212         xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1213                                         &dqp->q_logitem.qli_item.li_lsn);
1214
1215         /*
1216          * Attach an iodone routine so that we can remove this dquot from the
1217          * AIL and release the flush lock once the dquot is synced to disk.
1218          */
1219         xfs_buf_attach_iodone(bp, (void(*)(xfs_buf_t *, xfs_log_item_t *))
1220                               xfs_qm_dqflush_done, &(dqp->q_logitem.qli_item));
1221         /*
1222          * If the buffer is pinned then push on the log so we won't
1223          * get stuck waiting in the write for too long.
1224          */
1225         if (XFS_BUF_ISPINNED(bp)) {
1226                 trace_xfs_dqflush_force(dqp);
1227                 xfs_log_force(mp, 0);
1228         }
1229
1230         if (flags & SYNC_WAIT)
1231                 error = xfs_bwrite(mp, bp);
1232         else
1233                 xfs_bdwrite(mp, bp);
1234
1235         trace_xfs_dqflush_done(dqp);
1236
1237         /*
1238          * dqp is still locked, but caller is free to unlock it now.
1239          */
1240         return error;
1241
1242 }
1243
1244 /*
1245  * This is the dquot flushing I/O completion routine.  It is called
1246  * from interrupt level when the buffer containing the dquot is
1247  * flushed to disk.  It is responsible for removing the dquot logitem
1248  * from the AIL if it has not been re-logged, and unlocking the dquot's
1249  * flush lock. This behavior is very similar to that of inodes..
1250  */
1251 /*ARGSUSED*/
1252 STATIC void
1253 xfs_qm_dqflush_done(
1254         xfs_buf_t               *bp,
1255         xfs_dq_logitem_t        *qip)
1256 {
1257         xfs_dquot_t             *dqp;
1258         struct xfs_ail          *ailp;
1259
1260         dqp = qip->qli_dquot;
1261         ailp = qip->qli_item.li_ailp;
1262
1263         /*
1264          * We only want to pull the item from the AIL if its
1265          * location in the log has not changed since we started the flush.
1266          * Thus, we only bother if the dquot's lsn has
1267          * not changed. First we check the lsn outside the lock
1268          * since it's cheaper, and then we recheck while
1269          * holding the lock before removing the dquot from the AIL.
1270          */
1271         if ((qip->qli_item.li_flags & XFS_LI_IN_AIL) &&
1272             qip->qli_item.li_lsn == qip->qli_flush_lsn) {
1273
1274                 /* xfs_trans_ail_delete() drops the AIL lock. */
1275                 spin_lock(&ailp->xa_lock);
1276                 if (qip->qli_item.li_lsn == qip->qli_flush_lsn)
1277                         xfs_trans_ail_delete(ailp, (xfs_log_item_t*)qip);
1278                 else
1279                         spin_unlock(&ailp->xa_lock);
1280         }
1281
1282         /*
1283          * Release the dq's flush lock since we're done with it.
1284          */
1285         xfs_dqfunlock(dqp);
1286 }
1287
1288 int
1289 xfs_qm_dqlock_nowait(
1290         xfs_dquot_t *dqp)
1291 {
1292         return mutex_trylock(&dqp->q_qlock);
1293 }
1294
1295 void
1296 xfs_dqlock(
1297         xfs_dquot_t *dqp)
1298 {
1299         mutex_lock(&dqp->q_qlock);
1300 }
1301
1302 void
1303 xfs_dqunlock(
1304         xfs_dquot_t *dqp)
1305 {
1306         mutex_unlock(&(dqp->q_qlock));
1307         if (dqp->q_logitem.qli_dquot == dqp) {
1308                 /* Once was dqp->q_mount, but might just have been cleared */
1309                 xfs_trans_unlocked_item(dqp->q_logitem.qli_item.li_ailp,
1310                                         (xfs_log_item_t*)&(dqp->q_logitem));
1311         }
1312 }
1313
1314
1315 void
1316 xfs_dqunlock_nonotify(
1317         xfs_dquot_t *dqp)
1318 {
1319         mutex_unlock(&(dqp->q_qlock));
1320 }
1321
1322 /*
1323  * Lock two xfs_dquot structures.
1324  *
1325  * To avoid deadlocks we always lock the quota structure with
1326  * the lowerd id first.
1327  */
1328 void
1329 xfs_dqlock2(
1330         xfs_dquot_t     *d1,
1331         xfs_dquot_t     *d2)
1332 {
1333         if (d1 && d2) {
1334                 ASSERT(d1 != d2);
1335                 if (be32_to_cpu(d1->q_core.d_id) >
1336                     be32_to_cpu(d2->q_core.d_id)) {
1337                         mutex_lock(&d2->q_qlock);
1338                         mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1339                 } else {
1340                         mutex_lock(&d1->q_qlock);
1341                         mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1342                 }
1343         } else if (d1) {
1344                 mutex_lock(&d1->q_qlock);
1345         } else if (d2) {
1346                 mutex_lock(&d2->q_qlock);
1347         }
1348 }
1349
1350
1351 /*
1352  * Take a dquot out of the mount's dqlist as well as the hashlist.
1353  * This is called via unmount as well as quotaoff, and the purge
1354  * will always succeed unless there are soft (temp) references
1355  * outstanding.
1356  *
1357  * This returns 0 if it was purged, 1 if it wasn't. It's not an error code
1358  * that we're returning! XXXsup - not cool.
1359  */
1360 /* ARGSUSED */
1361 int
1362 xfs_qm_dqpurge(
1363         xfs_dquot_t     *dqp)
1364 {
1365         xfs_dqhash_t    *qh = dqp->q_hash;
1366         xfs_mount_t     *mp = dqp->q_mount;
1367
1368         ASSERT(mutex_is_locked(&mp->m_quotainfo->qi_dqlist_lock));
1369         ASSERT(mutex_is_locked(&dqp->q_hash->qh_lock));
1370
1371         xfs_dqlock(dqp);
1372         /*
1373          * We really can't afford to purge a dquot that is
1374          * referenced, because these are hard refs.
1375          * It shouldn't happen in general because we went thru _all_ inodes in
1376          * dqrele_all_inodes before calling this and didn't let the mountlock go.
1377          * However it is possible that we have dquots with temporary
1378          * references that are not attached to an inode. e.g. see xfs_setattr().
1379          */
1380         if (dqp->q_nrefs != 0) {
1381                 xfs_dqunlock(dqp);
1382                 mutex_unlock(&dqp->q_hash->qh_lock);
1383                 return (1);
1384         }
1385
1386         ASSERT(!list_empty(&dqp->q_freelist));
1387
1388         /*
1389          * If we're turning off quotas, we have to make sure that, for
1390          * example, we don't delete quota disk blocks while dquots are
1391          * in the process of getting written to those disk blocks.
1392          * This dquot might well be on AIL, and we can't leave it there
1393          * if we're turning off quotas. Basically, we need this flush
1394          * lock, and are willing to block on it.
1395          */
1396         if (!xfs_dqflock_nowait(dqp)) {
1397                 /*
1398                  * Block on the flush lock after nudging dquot buffer,
1399                  * if it is incore.
1400                  */
1401                 xfs_qm_dqflock_pushbuf_wait(dqp);
1402         }
1403
1404         /*
1405          * XXXIf we're turning this type of quotas off, we don't care
1406          * about the dirty metadata sitting in this dquot. OTOH, if
1407          * we're unmounting, we do care, so we flush it and wait.
1408          */
1409         if (XFS_DQ_IS_DIRTY(dqp)) {
1410                 int     error;
1411
1412                 /* dqflush unlocks dqflock */
1413                 /*
1414                  * Given that dqpurge is a very rare occurrence, it is OK
1415                  * that we're holding the hashlist and mplist locks
1416                  * across the disk write. But, ... XXXsup
1417                  *
1418                  * We don't care about getting disk errors here. We need
1419                  * to purge this dquot anyway, so we go ahead regardless.
1420                  */
1421                 error = xfs_qm_dqflush(dqp, SYNC_WAIT);
1422                 if (error)
1423                         xfs_fs_cmn_err(CE_WARN, mp,
1424                                 "xfs_qm_dqpurge: dquot %p flush failed", dqp);
1425                 xfs_dqflock(dqp);
1426         }
1427         ASSERT(atomic_read(&dqp->q_pincount) == 0);
1428         ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
1429                !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));
1430
1431         list_del_init(&dqp->q_hashlist);
1432         qh->qh_version++;
1433         list_del_init(&dqp->q_mplist);
1434         mp->m_quotainfo->qi_dqreclaims++;
1435         mp->m_quotainfo->qi_dquots--;
1436         /*
1437          * XXX Move this to the front of the freelist, if we can get the
1438          * freelist lock.
1439          */
1440         ASSERT(!list_empty(&dqp->q_freelist));
1441
1442         dqp->q_mount = NULL;
1443         dqp->q_hash = NULL;
1444         dqp->dq_flags = XFS_DQ_INACTIVE;
1445         memset(&dqp->q_core, 0, sizeof(dqp->q_core));
1446         xfs_dqfunlock(dqp);
1447         xfs_dqunlock(dqp);
1448         mutex_unlock(&qh->qh_lock);
1449         return (0);
1450 }
1451
1452
1453 #ifdef QUOTADEBUG
1454 void
1455 xfs_qm_dqprint(xfs_dquot_t *dqp)
1456 {
1457         cmn_err(CE_DEBUG, "-----------KERNEL DQUOT----------------");
1458         cmn_err(CE_DEBUG, "---- dquotID =  %d",
1459                 (int)be32_to_cpu(dqp->q_core.d_id));
1460         cmn_err(CE_DEBUG, "---- type    =  %s", DQFLAGTO_TYPESTR(dqp));
1461         cmn_err(CE_DEBUG, "---- fs      =  0x%p", dqp->q_mount);
1462         cmn_err(CE_DEBUG, "---- blkno   =  0x%x", (int) dqp->q_blkno);
1463         cmn_err(CE_DEBUG, "---- boffset =  0x%x", (int) dqp->q_bufoffset);
1464         cmn_err(CE_DEBUG, "---- blkhlimit =  %Lu (0x%x)",
1465                 be64_to_cpu(dqp->q_core.d_blk_hardlimit),
1466                 (int)be64_to_cpu(dqp->q_core.d_blk_hardlimit));
1467         cmn_err(CE_DEBUG, "---- blkslimit =  %Lu (0x%x)",
1468                 be64_to_cpu(dqp->q_core.d_blk_softlimit),
1469                 (int)be64_to_cpu(dqp->q_core.d_blk_softlimit));
1470         cmn_err(CE_DEBUG, "---- inohlimit =  %Lu (0x%x)",
1471                 be64_to_cpu(dqp->q_core.d_ino_hardlimit),
1472                 (int)be64_to_cpu(dqp->q_core.d_ino_hardlimit));
1473         cmn_err(CE_DEBUG, "---- inoslimit =  %Lu (0x%x)",
1474                 be64_to_cpu(dqp->q_core.d_ino_softlimit),
1475                 (int)be64_to_cpu(dqp->q_core.d_ino_softlimit));
1476         cmn_err(CE_DEBUG, "---- bcount  =  %Lu (0x%x)",
1477                 be64_to_cpu(dqp->q_core.d_bcount),
1478                 (int)be64_to_cpu(dqp->q_core.d_bcount));
1479         cmn_err(CE_DEBUG, "---- icount  =  %Lu (0x%x)",
1480                 be64_to_cpu(dqp->q_core.d_icount),
1481                 (int)be64_to_cpu(dqp->q_core.d_icount));
1482         cmn_err(CE_DEBUG, "---- btimer  =  %d",
1483                 (int)be32_to_cpu(dqp->q_core.d_btimer));
1484         cmn_err(CE_DEBUG, "---- itimer  =  %d",
1485                 (int)be32_to_cpu(dqp->q_core.d_itimer));
1486         cmn_err(CE_DEBUG, "---------------------------");
1487 }
1488 #endif
1489
1490 /*
1491  * Give the buffer a little push if it is incore and
1492  * wait on the flush lock.
1493  */
1494 void
1495 xfs_qm_dqflock_pushbuf_wait(
1496         xfs_dquot_t     *dqp)
1497 {
1498         xfs_buf_t       *bp;
1499
1500         /*
1501          * Check to see if the dquot has been flushed delayed
1502          * write.  If so, grab its buffer and send it
1503          * out immediately.  We'll be able to acquire
1504          * the flush lock when the I/O completes.
1505          */
1506         bp = xfs_incore(dqp->q_mount->m_ddev_targp, dqp->q_blkno,
1507                     XFS_QI_DQCHUNKLEN(dqp->q_mount), XBF_TRYLOCK);
1508         if (!bp)
1509                 goto out_lock;
1510
1511         if (XFS_BUF_ISDELAYWRITE(bp)) {
1512                 if (XFS_BUF_ISPINNED(bp))
1513                         xfs_log_force(dqp->q_mount, 0);
1514                 xfs_buf_delwri_promote(bp);
1515                 wake_up_process(bp->b_target->bt_task);
1516         }
1517         xfs_buf_relse(bp);
1518 out_lock:
1519         xfs_dqflock(dqp);
1520 }