fs/xfs/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_format.h"
  21 #include "xfs_bit.h"
  22 #include "xfs_log.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_bmap_util.h"
  33 #include "xfs_rtalloc.h"
  34 #include "xfs_error.h"
  35 #include "xfs_itable.h"
  36 #include "xfs_attr.h"
  37 #include "xfs_buf_item.h"
  38 #include "xfs_trans_space.h"
  39 #include "xfs_trans_priv.h"
  40 #include "xfs_qm.h"
  41 #include "xfs_cksum.h"
  42 #include "xfs_trace.h"
  43
  44 /*
  45  * Lock order:
  46  *
  47  * ip->i_lock
  48  *   qi->qi_tree_lock
  49  *     dquot->q_qlock (xfs_dqlock() and friends)
  50  *       dquot->q_flush (xfs_dqflock() and friends)
  51  *       qi->qi_lru_lock
  52  *
  53  * If two dquots need to be locked the order is user before group/project,
  54  * otherwise by the lowest id first, see xfs_dqlock2.
  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 struct kmem_zone                *xfs_qm_dqtrxzone;
  65 static struct kmem_zone         *xfs_qm_dqzone;
  66
  67 static struct lock_class_key xfs_dquot_other_class;
  68
  69 /*
  70  * This is called to free all the memory associated with a dquot
  71  */
  72 void
  73 xfs_qm_dqdestroy(
  74         xfs_dquot_t     *dqp)
  75 {
  76         ASSERT(list_empty(&dqp->q_lru));
  77
  78         mutex_destroy(&dqp->q_qlock);
  79         kmem_zone_free(xfs_qm_dqzone, dqp);
  80
  81         XFS_STATS_DEC(xs_qm_dquot);
  82 }
  83
  84 /*
  85  * If default limits are in force, push them into the dquot now.
  86  * We overwrite the dquot limits only if they are zero and this
  87  * is not the root dquot.
  88  */
  89 void
  90 xfs_qm_adjust_dqlimits(
  91         struct xfs_mount        *mp,
  92         struct xfs_dquot        *dq)
  93 {
  94         struct xfs_quotainfo    *q = mp->m_quotainfo;
  95         struct xfs_disk_dquot   *d = &dq->q_core;
  96         int                     prealloc = 0;
  97
  98         ASSERT(d->d_id);
  99
 100         if (q->qi_bsoftlimit && !d->d_blk_softlimit) {
 101                 d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
 102                 prealloc = 1;
 103         }
 104         if (q->qi_bhardlimit && !d->d_blk_hardlimit) {
 105                 d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
 106                 prealloc = 1;
 107         }
 108         if (q->qi_isoftlimit && !d->d_ino_softlimit)
 109                 d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
 110         if (q->qi_ihardlimit && !d->d_ino_hardlimit)
 111                 d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
 112         if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
 113                 d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
 114         if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
 115                 d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
 116
 117         if (prealloc)
 118                 xfs_dquot_set_prealloc_limits(dq);
 119 }
 120
 121 /*
 122  * Check the limits and timers of a dquot and start or reset timers
 123  * if necessary.
 124  * This gets called even when quota enforcement is OFF, which makes our
 125  * life a little less complicated. (We just don't reject any quota
 126  * reservations in that case, when enforcement is off).
 127  * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
 128  * enforcement's off.
 129  * In contrast, warnings are a little different in that they don't
 130  * 'automatically' get started when limits get exceeded.  They do
 131  * get reset to zero, however, when we find the count to be under
 132  * the soft limit (they are only ever set non-zero via userspace).
 133  */
 134 void
 135 xfs_qm_adjust_dqtimers(
 136         xfs_mount_t             *mp,
 137         xfs_disk_dquot_t        *d)
 138 {
 139         ASSERT(d->d_id);
 140
 141 #ifdef DEBUG
 142         if (d->d_blk_hardlimit)
 143                 ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
 144                        be64_to_cpu(d->d_blk_hardlimit));
 145         if (d->d_ino_hardlimit)
 146                 ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
 147                        be64_to_cpu(d->d_ino_hardlimit));
 148         if (d->d_rtb_hardlimit)
 149                 ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
 150                        be64_to_cpu(d->d_rtb_hardlimit));
 151 #endif
 152
 153         if (!d->d_btimer) {
 154                 if ((d->d_blk_softlimit &&
 155                      (be64_to_cpu(d->d_bcount) >
 156                       be64_to_cpu(d->d_blk_softlimit))) ||
 157                     (d->d_blk_hardlimit &&
 158                      (be64_to_cpu(d->d_bcount) >
 159                       be64_to_cpu(d->d_blk_hardlimit)))) {
 160                         d->d_btimer = cpu_to_be32(get_seconds() +
 161                                         mp->m_quotainfo->qi_btimelimit);
 162                 } else {
 163                         d->d_bwarns = 0;
 164                 }
 165         } else {
 166                 if ((!d->d_blk_softlimit ||
 167                      (be64_to_cpu(d->d_bcount) <=
 168                       be64_to_cpu(d->d_blk_softlimit))) &&
 169                     (!d->d_blk_hardlimit ||
 170                     (be64_to_cpu(d->d_bcount) <=
 171                      be64_to_cpu(d->d_blk_hardlimit)))) {
 172                         d->d_btimer = 0;
 173                 }
 174         }
 175
 176         if (!d->d_itimer) {
 177                 if ((d->d_ino_softlimit &&
 178                      (be64_to_cpu(d->d_icount) >
 179                       be64_to_cpu(d->d_ino_softlimit))) ||
 180                     (d->d_ino_hardlimit &&
 181                      (be64_to_cpu(d->d_icount) >
 182                       be64_to_cpu(d->d_ino_hardlimit)))) {
 183                         d->d_itimer = cpu_to_be32(get_seconds() +
 184                                         mp->m_quotainfo->qi_itimelimit);
 185                 } else {
 186                         d->d_iwarns = 0;
 187                 }
 188         } else {
 189                 if ((!d->d_ino_softlimit ||
 190                      (be64_to_cpu(d->d_icount) <=
 191                       be64_to_cpu(d->d_ino_softlimit)))  &&
 192                     (!d->d_ino_hardlimit ||
 193                      (be64_to_cpu(d->d_icount) <=
 194                       be64_to_cpu(d->d_ino_hardlimit)))) {
 195                         d->d_itimer = 0;
 196                 }
 197         }
 198
 199         if (!d->d_rtbtimer) {
 200                 if ((d->d_rtb_softlimit &&
 201                      (be64_to_cpu(d->d_rtbcount) >
 202                       be64_to_cpu(d->d_rtb_softlimit))) ||
 203                     (d->d_rtb_hardlimit &&
 204                      (be64_to_cpu(d->d_rtbcount) >
 205                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 206                         d->d_rtbtimer = cpu_to_be32(get_seconds() +
 207                                         mp->m_quotainfo->qi_rtbtimelimit);
 208                 } else {
 209                         d->d_rtbwarns = 0;
 210                 }
 211         } else {
 212                 if ((!d->d_rtb_softlimit ||
 213                      (be64_to_cpu(d->d_rtbcount) <=
 214                       be64_to_cpu(d->d_rtb_softlimit))) &&
 215                     (!d->d_rtb_hardlimit ||
 216                      (be64_to_cpu(d->d_rtbcount) <=
 217                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 218                         d->d_rtbtimer = 0;
 219                 }
 220         }
 221 }
 222
 223 /*
 224  * initialize a buffer full of dquots and log the whole thing
 225  */
 226 STATIC void
 227 xfs_qm_init_dquot_blk(
 228         xfs_trans_t     *tp,
 229         xfs_mount_t     *mp,
 230         xfs_dqid_t      id,
 231         uint            type,
 232         xfs_buf_t       *bp)
 233 {
 234         struct xfs_quotainfo    *q = mp->m_quotainfo;
 235         xfs_dqblk_t     *d;
 236         int             curid, i;
 237
 238         ASSERT(tp);
 239         ASSERT(xfs_buf_islocked(bp));
 240
 241         d = bp->b_addr;
 242
 243         /*
 244          * ID of the first dquot in the block - id's are zero based.
 245          */
 246         curid = id - (id % q->qi_dqperchunk);
 247         ASSERT(curid >= 0);
 248         memset(d, 0, BBTOB(q->qi_dqchunklen));
 249         for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++) {
 250                 d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 251                 d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 252                 d->dd_diskdq.d_id = cpu_to_be32(curid);
 253                 d->dd_diskdq.d_flags = type;
 254                 if (xfs_sb_version_hascrc(&mp->m_sb)) {
 255                         uuid_copy(&d->dd_uuid, &mp->m_sb.sb_uuid);
 256                         xfs_update_cksum((char *)d, sizeof(struct xfs_dqblk),
 257                                          XFS_DQUOT_CRC_OFF);
 258                 }
 259         }
 260
 261         xfs_trans_dquot_buf(tp, bp,
 262                             (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
 263                             ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
 264                              XFS_BLF_GDQUOT_BUF)));
 265         xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
 266 }
 267
 268 /*
 269  * Initialize the dynamic speculative preallocation thresholds. The lo/hi
 270  * watermarks correspond to the soft and hard limits by default. If a soft limit
 271  * is not specified, we use 95% of the hard limit.
 272  */
 273 void
 274 xfs_dquot_set_prealloc_limits(struct xfs_dquot *dqp)
 275 {
 276         __uint64_t space;
 277
 278         dqp->q_prealloc_hi_wmark = be64_to_cpu(dqp->q_core.d_blk_hardlimit);
 279         dqp->q_prealloc_lo_wmark = be64_to_cpu(dqp->q_core.d_blk_softlimit);
 280         if (!dqp->q_prealloc_lo_wmark) {
 281                 dqp->q_prealloc_lo_wmark = dqp->q_prealloc_hi_wmark;
 282                 do_div(dqp->q_prealloc_lo_wmark, 100);
 283                 dqp->q_prealloc_lo_wmark *= 95;
 284         }
 285
 286         space = dqp->q_prealloc_hi_wmark;
 287
 288         do_div(space, 100);
 289         dqp->q_low_space[XFS_QLOWSP_1_PCNT] = space;
 290         dqp->q_low_space[XFS_QLOWSP_3_PCNT] = space * 3;
 291         dqp->q_low_space[XFS_QLOWSP_5_PCNT] = space * 5;
 292 }
 293
 294 STATIC bool
 295 xfs_dquot_buf_verify_crc(
 296         struct xfs_mount        *mp,
 297         struct xfs_buf          *bp)
 298 {
 299         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 300         int                     ndquots;
 301         int                     i;
 302
 303         if (!xfs_sb_version_hascrc(&mp->m_sb))
 304                 return true;
 305
 306         /*
 307          * if we are in log recovery, the quota subsystem has not been
 308          * initialised so we have no quotainfo structure. In that case, we need
 309          * to manually calculate the number of dquots in the buffer.
 310          */
 311         if (mp->m_quotainfo)
 312                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 313         else
 314                 ndquots = xfs_qm_calc_dquots_per_chunk(mp,
 315                                         XFS_BB_TO_FSB(mp, bp->b_length));
 316
 317         for (i = 0; i < ndquots; i++, d++) {
 318                 if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
 319                                  XFS_DQUOT_CRC_OFF))
 320                         return false;
 321                 if (!uuid_equal(&d->dd_uuid, &mp->m_sb.sb_uuid))
 322                         return false;
 323         }
 324         return true;
 325 }
 326
 327 STATIC bool
 328 xfs_dquot_buf_verify(
 329         struct xfs_mount        *mp,
 330         struct xfs_buf          *bp)
 331 {
 332         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 333         xfs_dqid_t              id = 0;
 334         int                     ndquots;
 335         int                     i;
 336
 337         /*
 338          * if we are in log recovery, the quota subsystem has not been
 339          * initialised so we have no quotainfo structure. In that case, we need
 340          * to manually calculate the number of dquots in the buffer.
 341          */
 342         if (mp->m_quotainfo)
 343                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 344         else
 345                 ndquots = xfs_qm_calc_dquots_per_chunk(mp, bp->b_length);
 346
 347         /*
 348          * On the first read of the buffer, verify that each dquot is valid.
 349          * We don't know what the id of the dquot is supposed to be, just that
 350          * they should be increasing monotonically within the buffer. If the
 351          * first id is corrupt, then it will fail on the second dquot in the
 352          * buffer so corruptions could point to the wrong dquot in this case.
 353          */
 354         for (i = 0; i < ndquots; i++) {
 355                 struct xfs_disk_dquot   *ddq;
 356                 int                     error;
 357
 358                 ddq = &d[i].dd_diskdq;
 359
 360                 if (i == 0)
 361                         id = be32_to_cpu(ddq->d_id);
 362
 363                 error = xfs_qm_dqcheck(mp, ddq, id + i, 0, XFS_QMOPT_DOWARN,
 364                                        "xfs_dquot_buf_verify");
 365                 if (error)
 366                         return false;
 367         }
 368         return true;
 369 }
 370
 371 static void
 372 xfs_dquot_buf_read_verify(
 373         struct xfs_buf  *bp)
 374 {
 375         struct xfs_mount        *mp = bp->b_target->bt_mount;
 376
 377         if (!xfs_dquot_buf_verify_crc(mp, bp) || !xfs_dquot_buf_verify(mp, bp)) {
 378                 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
 379                 xfs_buf_ioerror(bp, EFSCORRUPTED);
 380         }
 381 }
 382
 383 /*
 384  * we don't calculate the CRC here as that is done when the dquot is flushed to
 385  * the buffer after the update is done. This ensures that the dquot in the
 386  * buffer always has an up-to-date CRC value.
 387  */
 388 void
 389 xfs_dquot_buf_write_verify(
 390         struct xfs_buf  *bp)
 391 {
 392         struct xfs_mount        *mp = bp->b_target->bt_mount;
 393
 394         if (!xfs_dquot_buf_verify(mp, bp)) {
 395                 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
 396                 xfs_buf_ioerror(bp, EFSCORRUPTED);
 397                 return;
 398         }
 399 }
 400
 401 const struct xfs_buf_ops xfs_dquot_buf_ops = {
 402         .verify_read = xfs_dquot_buf_read_verify,
 403         .verify_write = xfs_dquot_buf_write_verify,
 404 };
 405
 406 /*
 407  * Allocate a block and fill it with dquots.
 408  * This is called when the bmapi finds a hole.
 409  */
 410 STATIC int
 411 xfs_qm_dqalloc(
 412         xfs_trans_t     **tpp,
 413         xfs_mount_t     *mp,
 414         xfs_dquot_t     *dqp,
 415         xfs_inode_t     *quotip,
 416         xfs_fileoff_t   offset_fsb,
 417         xfs_buf_t       **O_bpp)
 418 {
 419         xfs_fsblock_t   firstblock;
 420         xfs_bmap_free_t flist;
 421         xfs_bmbt_irec_t map;
 422         int             nmaps, error, committed;
 423         xfs_buf_t       *bp;
 424         xfs_trans_t     *tp = *tpp;
 425
 426         ASSERT(tp != NULL);
 427
 428         trace_xfs_dqalloc(dqp);
 429
 430         /*
 431          * Initialize the bmap freelist prior to calling bmapi code.
 432          */
 433         xfs_bmap_init(&flist, &firstblock);
 434         xfs_ilock(quotip, XFS_ILOCK_EXCL);
 435         /*
 436          * Return if this type of quotas is turned off while we didn't
 437          * have an inode lock
 438          */
 439         if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
 440                 xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 441                 return (ESRCH);
 442         }
 443
 444         xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
 445         nmaps = 1;
 446         error = xfs_bmapi_write(tp, quotip, offset_fsb,
 447                                 XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
 448                                 &firstblock, XFS_QM_DQALLOC_SPACE_RES(mp),
 449                                 &map, &nmaps, &flist);
 450         if (error)
 451                 goto error0;
 452         ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
 453         ASSERT(nmaps == 1);
 454         ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 455                (map.br_startblock != HOLESTARTBLOCK));
 456
 457         /*
 458          * Keep track of the blkno to save a lookup later
 459          */
 460         dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 461
 462         /* now we can just get the buffer (there's nothing to read yet) */
 463         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
 464                                dqp->q_blkno,
 465                                mp->m_quotainfo->qi_dqchunklen,
 466                                0);
 467
 468         error = xfs_buf_geterror(bp);
 469         if (error)
 470                 goto error1;
 471         bp->b_ops = &xfs_dquot_buf_ops;
 472
 473         /*
 474          * Make a chunk of dquots out of this buffer and log
 475          * the entire thing.
 476          */
 477         xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
 478                               dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
 479
 480         /*
 481          * xfs_bmap_finish() may commit the current transaction and
 482          * start a second transaction if the freelist is not empty.
 483          *
 484          * Since we still want to modify this buffer, we need to
 485          * ensure that the buffer is not released on commit of
 486          * the first transaction and ensure the buffer is added to the
 487          * second transaction.
 488          *
 489          * If there is only one transaction then don't stop the buffer
 490          * from being released when it commits later on.
 491          */
 492
 493         xfs_trans_bhold(tp, bp);
 494
 495         if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
 496                 goto error1;
 497         }
 498
 499         if (committed) {
 500                 tp = *tpp;
 501                 xfs_trans_bjoin(tp, bp);
 502         } else {
 503                 xfs_trans_bhold_release(tp, bp);
 504         }
 505
 506         *O_bpp = bp;
 507         return 0;
 508
 509       error1:
 510         xfs_bmap_cancel(&flist);
 511       error0:
 512         xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 513
 514         return (error);
 515 }
 516 STATIC int
 517 xfs_qm_dqrepair(
 518         struct xfs_mount        *mp,
 519         struct xfs_trans        *tp,
 520         struct xfs_dquot        *dqp,
 521         xfs_dqid_t              firstid,
 522         struct xfs_buf          **bpp)
 523 {
 524         int                     error;
 525         struct xfs_disk_dquot   *ddq;
 526         struct xfs_dqblk        *d;
 527         int                     i;
 528
 529         /*
 530          * Read the buffer without verification so we get the corrupted
 531          * buffer returned to us. make sure we verify it on write, though.
 532          */
 533         error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, dqp->q_blkno,
 534                                    mp->m_quotainfo->qi_dqchunklen,
 535                                    0, bpp, NULL);
 536
 537         if (error) {
 538                 ASSERT(*bpp == NULL);
 539                 return XFS_ERROR(error);
 540         }
 541         (*bpp)->b_ops = &xfs_dquot_buf_ops;
 542
 543         ASSERT(xfs_buf_islocked(*bpp));
 544         d = (struct xfs_dqblk *)(*bpp)->b_addr;
 545
 546         /* Do the actual repair of dquots in this buffer */
 547         for (i = 0; i < mp->m_quotainfo->qi_dqperchunk; i++) {
 548                 ddq = &d[i].dd_diskdq;
 549                 error = xfs_qm_dqcheck(mp, ddq, firstid + i,
 550                                        dqp->dq_flags & XFS_DQ_ALLTYPES,
 551                                        XFS_QMOPT_DQREPAIR, "xfs_qm_dqrepair");
 552                 if (error) {
 553                         /* repair failed, we're screwed */
 554                         xfs_trans_brelse(tp, *bpp);
 555                         return XFS_ERROR(EIO);
 556                 }
 557         }
 558
 559         return 0;
 560 }
 561
 562 /*
 563  * Maps a dquot to the buffer containing its on-disk version.
 564  * This returns a ptr to the buffer containing the on-disk dquot
 565  * in the bpp param, and a ptr to the on-disk dquot within that buffer
 566  */
 567 STATIC int
 568 xfs_qm_dqtobp(
 569         xfs_trans_t             **tpp,
 570         xfs_dquot_t             *dqp,
 571         xfs_disk_dquot_t        **O_ddpp,
 572         xfs_buf_t               **O_bpp,
 573         uint                    flags)
 574 {
 575         struct xfs_bmbt_irec    map;
 576         int                     nmaps = 1, error;
 577         struct xfs_buf          *bp;
 578         struct xfs_inode        *quotip = xfs_dq_to_quota_inode(dqp);
 579         struct xfs_mount        *mp = dqp->q_mount;
 580         xfs_dqid_t              id = be32_to_cpu(dqp->q_core.d_id);
 581         struct xfs_trans        *tp = (tpp ? *tpp : NULL);
 582
 583         dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
 584
 585         xfs_ilock(quotip, XFS_ILOCK_SHARED);
 586         if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
 587                 /*
 588                  * Return if this type of quotas is turned off while we
 589                  * didn't have the quota inode lock.
 590                  */
 591                 xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 592                 return ESRCH;
 593         }
 594
 595         /*
 596          * Find the block map; no allocations yet
 597          */
 598         error = xfs_bmapi_read(quotip, dqp->q_fileoffset,
 599                                XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
 600
 601         xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 602         if (error)
 603                 return error;
 604
 605         ASSERT(nmaps == 1);
 606         ASSERT(map.br_blockcount == 1);
 607
 608         /*
 609          * Offset of dquot in the (fixed sized) dquot chunk.
 610          */
 611         dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
 612                 sizeof(xfs_dqblk_t);
 613
 614         ASSERT(map.br_startblock != DELAYSTARTBLOCK);
 615         if (map.br_startblock == HOLESTARTBLOCK) {
 616                 /*
 617                  * We don't allocate unless we're asked to
 618                  */
 619                 if (!(flags & XFS_QMOPT_DQALLOC))
 620                         return ENOENT;
 621
 622                 ASSERT(tp);
 623                 error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
 624                                         dqp->q_fileoffset, &bp);
 625                 if (error)
 626                         return error;
 627                 tp = *tpp;
 628         } else {
 629                 trace_xfs_dqtobp_read(dqp);
 630
 631                 /*
 632                  * store the blkno etc so that we don't have to do the
 633                  * mapping all the time
 634                  */
 635                 dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 636
 637                 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 638                                            dqp->q_blkno,
 639                                            mp->m_quotainfo->qi_dqchunklen,
 640                                            0, &bp, &xfs_dquot_buf_ops);
 641
 642                 if (error == EFSCORRUPTED && (flags & XFS_QMOPT_DQREPAIR)) {
 643                         xfs_dqid_t firstid = (xfs_dqid_t)map.br_startoff *
 644                                                 mp->m_quotainfo->qi_dqperchunk;
 645                         ASSERT(bp == NULL);
 646                         error = xfs_qm_dqrepair(mp, tp, dqp, firstid, &bp);
 647                 }
 648
 649                 if (error) {
 650                         ASSERT(bp == NULL);
 651                         return XFS_ERROR(error);
 652                 }
 653         }
 654
 655         ASSERT(xfs_buf_islocked(bp));
 656         *O_bpp = bp;
 657         *O_ddpp = bp->b_addr + dqp->q_bufoffset;
 658
 659         return (0);
 660 }
 661
 662
 663 /*
 664  * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
 665  * and release the buffer immediately.
 666  *
 667  * If XFS_QMOPT_DQALLOC is set, allocate a dquot on disk if it needed.
 668  */
 669 int
 670 xfs_qm_dqread(
 671         struct xfs_mount        *mp,
 672         xfs_dqid_t              id,
 673         uint                    type,
 674         uint                    flags,
 675         struct xfs_dquot        **O_dqpp)
 676 {
 677         struct xfs_dquot        *dqp;
 678         struct xfs_disk_dquot   *ddqp;
 679         struct xfs_buf          *bp;
 680         struct xfs_trans        *tp = NULL;
 681         int                     error;
 682         int                     cancelflags = 0;
 683
 684
 685         dqp = kmem_zone_zalloc(xfs_qm_dqzone, KM_SLEEP);
 686
 687         dqp->dq_flags = type;
 688         dqp->q_core.d_id = cpu_to_be32(id);
 689         dqp->q_mount = mp;
 690         INIT_LIST_HEAD(&dqp->q_lru);
 691         mutex_init(&dqp->q_qlock);
 692         init_waitqueue_head(&dqp->q_pinwait);
 693
 694         /*
 695          * Because we want to use a counting completion, complete
 696          * the flush completion once to allow a single access to
 697          * the flush completion without blocking.
 698          */
 699         init_completion(&dqp->q_flush);
 700         complete(&dqp->q_flush);
 701
 702         /*
 703          * Make sure group quotas have a different lock class than user
 704          * quotas.
 705          */
 706         if (!(type & XFS_DQ_USER))
 707                 lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
 708
 709         XFS_STATS_INC(xs_qm_dquot);
 710
 711         trace_xfs_dqread(dqp);
 712
 713         if (flags & XFS_QMOPT_DQALLOC) {
 714                 tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
 715                 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_attrsetm,
 716                                           XFS_QM_DQALLOC_SPACE_RES(mp), 0);
 717                 if (error)
 718                         goto error1;
 719                 cancelflags = XFS_TRANS_RELEASE_LOG_RES;
 720         }
 721
 722         /*
 723          * get a pointer to the on-disk dquot and the buffer containing it
 724          * dqp already knows its own type (GROUP/USER).
 725          */
 726         error = xfs_qm_dqtobp(&tp, dqp, &ddqp, &bp, flags);
 727         if (error) {
 728                 /*
 729                  * This can happen if quotas got turned off (ESRCH),
 730                  * or if the dquot didn't exist on disk and we ask to
 731                  * allocate (ENOENT).
 732                  */
 733                 trace_xfs_dqread_fail(dqp);
 734                 cancelflags |= XFS_TRANS_ABORT;
 735                 goto error1;
 736         }
 737
 738         /* copy everything from disk dquot to the incore dquot */
 739         memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
 740         xfs_qm_dquot_logitem_init(dqp);
 741
 742         /*
 743          * Reservation counters are defined as reservation plus current usage
 744          * to avoid having to add every time.
 745          */
 746         dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
 747         dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
 748         dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
 749
 750         /* initialize the dquot speculative prealloc thresholds */
 751         xfs_dquot_set_prealloc_limits(dqp);
 752
 753         /* Mark the buf so that this will stay incore a little longer */
 754         xfs_buf_set_ref(bp, XFS_DQUOT_REF);
 755
 756         /*
 757          * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
 758          * So we need to release with xfs_trans_brelse().
 759          * The strategy here is identical to that of inodes; we lock
 760          * the dquot in xfs_qm_dqget() before making it accessible to
 761          * others. This is because dquots, like inodes, need a good level of
 762          * concurrency, and we don't want to take locks on the entire buffers
 763          * for dquot accesses.
 764          * Note also that the dquot buffer may even be dirty at this point, if
 765          * this particular dquot was repaired. We still aren't afraid to
 766          * brelse it because we have the changes incore.
 767          */
 768         ASSERT(xfs_buf_islocked(bp));
 769         xfs_trans_brelse(tp, bp);
 770
 771         if (tp) {
 772                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 773                 if (error)
 774                         goto error0;
 775         }
 776
 777         *O_dqpp = dqp;
 778         return error;
 779
 780 error1:
 781         if (tp)
 782                 xfs_trans_cancel(tp, cancelflags);
 783 error0:
 784         xfs_qm_dqdestroy(dqp);
 785         *O_dqpp = NULL;
 786         return error;
 787 }
 788
 789 /*
 790  * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
 791  * a locked dquot, doing an allocation (if requested) as needed.
 792  * When both an inode and an id are given, the inode's id takes precedence.
 793  * That is, if the id changes while we don't hold the ilock inside this
 794  * function, the new dquot is returned, not necessarily the one requested
 795  * in the id argument.
 796  */
 797 int
 798 xfs_qm_dqget(
 799         xfs_mount_t     *mp,
 800         xfs_inode_t     *ip,      /* locked inode (optional) */
 801         xfs_dqid_t      id,       /* uid/projid/gid depending on type */
 802         uint            type,     /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
 803         uint            flags,    /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
 804         xfs_dquot_t     **O_dqpp) /* OUT : locked incore dquot */
 805 {
 806         struct xfs_quotainfo    *qi = mp->m_quotainfo;
 807         struct radix_tree_root *tree = xfs_dquot_tree(qi, type);
 808         struct xfs_dquot        *dqp;
 809         int                     error;
 810
 811         ASSERT(XFS_IS_QUOTA_RUNNING(mp));
 812         if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
 813             (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
 814             (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
 815                 return (ESRCH);
 816         }
 817
 818 #ifdef DEBUG
 819         if (xfs_do_dqerror) {
 820                 if ((xfs_dqerror_target == mp->m_ddev_targp) &&
 821                     (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
 822                         xfs_debug(mp, "Returning error in dqget");
 823                         return (EIO);
 824                 }
 825         }
 826
 827         ASSERT(type == XFS_DQ_USER ||
 828                type == XFS_DQ_PROJ ||
 829                type == XFS_DQ_GROUP);
 830         if (ip) {
 831                 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 832                 ASSERT(xfs_inode_dquot(ip, type) == NULL);
 833         }
 834 #endif
 835
 836 restart:
 837         mutex_lock(&qi->qi_tree_lock);
 838         dqp = radix_tree_lookup(tree, id);
 839         if (dqp) {
 840                 xfs_dqlock(dqp);
 841                 if (dqp->dq_flags & XFS_DQ_FREEING) {
 842                         xfs_dqunlock(dqp);
 843                         mutex_unlock(&qi->qi_tree_lock);
 844                         trace_xfs_dqget_freeing(dqp);
 845                         delay(1);
 846                         goto restart;
 847                 }
 848
 849                 dqp->q_nrefs++;
 850                 mutex_unlock(&qi->qi_tree_lock);
 851
 852                 trace_xfs_dqget_hit(dqp);
 853                 XFS_STATS_INC(xs_qm_dqcachehits);
 854                 *O_dqpp = dqp;
 855                 return 0;
 856         }
 857         mutex_unlock(&qi->qi_tree_lock);
 858         XFS_STATS_INC(xs_qm_dqcachemisses);
 859
 860         /*
 861          * Dquot cache miss. We don't want to keep the inode lock across
 862          * a (potential) disk read. Also we don't want to deal with the lock
 863          * ordering between quotainode and this inode. OTOH, dropping the inode
 864          * lock here means dealing with a chown that can happen before
 865          * we re-acquire the lock.
 866          */
 867         if (ip)
 868                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 869
 870         error = xfs_qm_dqread(mp, id, type, flags, &dqp);
 871
 872         if (ip)
 873                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 874
 875         if (error)
 876                 return error;
 877
 878         if (ip) {
 879                 /*
 880                  * A dquot could be attached to this inode by now, since
 881                  * we had dropped the ilock.
 882                  */
 883                 if (xfs_this_quota_on(mp, type)) {
 884                         struct xfs_dquot        *dqp1;
 885
 886                         dqp1 = xfs_inode_dquot(ip, type);
 887                         if (dqp1) {
 888                                 xfs_qm_dqdestroy(dqp);
 889                                 dqp = dqp1;
 890                                 xfs_dqlock(dqp);
 891                                 goto dqret;
 892                         }
 893                 } else {
 894                         /* inode stays locked on return */
 895                         xfs_qm_dqdestroy(dqp);
 896                         return XFS_ERROR(ESRCH);
 897                 }
 898         }
 899
 900         mutex_lock(&qi->qi_tree_lock);
 901         error = -radix_tree_insert(tree, id, dqp);
 902         if (unlikely(error)) {
 903                 WARN_ON(error != EEXIST);
 904
 905                 /*
 906                  * Duplicate found. Just throw away the new dquot and start
 907                  * over.
 908                  */
 909                 mutex_unlock(&qi->qi_tree_lock);
 910                 trace_xfs_dqget_dup(dqp);
 911                 xfs_qm_dqdestroy(dqp);
 912                 XFS_STATS_INC(xs_qm_dquot_dups);
 913                 goto restart;
 914         }
 915
 916         /*
 917          * We return a locked dquot to the caller, with a reference taken
 918          */
 919         xfs_dqlock(dqp);
 920         dqp->q_nrefs = 1;
 921
 922         qi->qi_dquots++;
 923         mutex_unlock(&qi->qi_tree_lock);
 924
 925  dqret:
 926         ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
 927         trace_xfs_dqget_miss(dqp);
 928         *O_dqpp = dqp;
 929         return (0);
 930 }
 931
 932
 933 STATIC void
 934 xfs_qm_dqput_final(
 935         struct xfs_dquot        *dqp)
 936 {
 937         struct xfs_quotainfo    *qi = dqp->q_mount->m_quotainfo;
 938         struct xfs_dquot        *gdqp;
 939         struct xfs_dquot        *pdqp;
 940
 941         trace_xfs_dqput_free(dqp);
 942
 943         if (list_lru_add(&qi->qi_lru, &dqp->q_lru))
 944                 XFS_STATS_INC(xs_qm_dquot_unused);
 945
 946         /*
 947          * If we just added a udquot to the freelist, then we want to release
 948          * the gdquot/pdquot reference that it (probably) has. Otherwise it'll
 949          * keep the gdquot/pdquot from getting reclaimed.
 950          */
 951         gdqp = dqp->q_gdquot;
 952         if (gdqp) {
 953                 xfs_dqlock(gdqp);
 954                 dqp->q_gdquot = NULL;
 955         }
 956
 957         pdqp = dqp->q_pdquot;
 958         if (pdqp) {
 959                 xfs_dqlock(pdqp);
 960                 dqp->q_pdquot = NULL;
 961         }
 962         xfs_dqunlock(dqp);
 963
 964         /*
 965          * If we had a group/project quota hint, release it now.
 966          */
 967         if (gdqp)
 968                 xfs_qm_dqput(gdqp);
 969         if (pdqp)
 970                 xfs_qm_dqput(pdqp);
 971 }
 972
 973 /*
 974  * Release a reference to the dquot (decrement ref-count) and unlock it.
 975  *
 976  * If there is a group quota attached to this dquot, carefully release that
 977  * too without tripping over deadlocks'n'stuff.
 978  */
 979 void
 980 xfs_qm_dqput(
 981         struct xfs_dquot        *dqp)
 982 {
 983         ASSERT(dqp->q_nrefs > 0);
 984         ASSERT(XFS_DQ_IS_LOCKED(dqp));
 985
 986         trace_xfs_dqput(dqp);
 987
 988         if (--dqp->q_nrefs > 0)
 989                 xfs_dqunlock(dqp);
 990         else
 991                 xfs_qm_dqput_final(dqp);
 992 }
 993
 994 /*
 995  * Release a dquot. Flush it if dirty, then dqput() it.
 996  * dquot must not be locked.
 997  */
 998 void
 999 xfs_qm_dqrele(
1000         xfs_dquot_t     *dqp)
1001 {
1002         if (!dqp)
1003                 return;
1004
1005         trace_xfs_dqrele(dqp);
1006
1007         xfs_dqlock(dqp);
1008         /*
1009          * We don't care to flush it if the dquot is dirty here.
1010          * That will create stutters that we want to avoid.
1011          * Instead we do a delayed write when we try to reclaim
1012          * a dirty dquot. Also xfs_sync will take part of the burden...
1013          */
1014         xfs_qm_dqput(dqp);
1015 }
1016
1017 /*
1018  * This is the dquot flushing I/O completion routine.  It is called
1019  * from interrupt level when the buffer containing the dquot is
1020  * flushed to disk.  It is responsible for removing the dquot logitem
1021  * from the AIL if it has not been re-logged, and unlocking the dquot's
1022  * flush lock. This behavior is very similar to that of inodes..
1023  */
1024 STATIC void
1025 xfs_qm_dqflush_done(
1026         struct xfs_buf          *bp,
1027         struct xfs_log_item     *lip)
1028 {
1029         xfs_dq_logitem_t        *qip = (struct xfs_dq_logitem *)lip;
1030         xfs_dquot_t             *dqp = qip->qli_dquot;
1031         struct xfs_ail          *ailp = lip->li_ailp;
1032
1033         /*
1034          * We only want to pull the item from the AIL if its
1035          * location in the log has not changed since we started the flush.
1036          * Thus, we only bother if the dquot's lsn has
1037          * not changed. First we check the lsn outside the lock
1038          * since it's cheaper, and then we recheck while
1039          * holding the lock before removing the dquot from the AIL.
1040          */
1041         if ((lip->li_flags & XFS_LI_IN_AIL) &&
1042             lip->li_lsn == qip->qli_flush_lsn) {
1043
1044                 /* xfs_trans_ail_delete() drops the AIL lock. */
1045                 spin_lock(&ailp->xa_lock);
1046                 if (lip->li_lsn == qip->qli_flush_lsn)
1047                         xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE);
1048                 else
1049                         spin_unlock(&ailp->xa_lock);
1050         }
1051
1052         /*
1053          * Release the dq's flush lock since we're done with it.
1054          */
1055         xfs_dqfunlock(dqp);
1056 }
1057
1058 /*
1059  * Write a modified dquot to disk.
1060  * The dquot must be locked and the flush lock too taken by caller.
1061  * The flush lock will not be unlocked until the dquot reaches the disk,
1062  * but the dquot is free to be unlocked and modified by the caller
1063  * in the interim. Dquot is still locked on return. This behavior is
1064  * identical to that of inodes.
1065  */
1066 int
1067 xfs_qm_dqflush(
1068         struct xfs_dquot        *dqp,
1069         struct xfs_buf          **bpp)
1070 {
1071         struct xfs_mount        *mp = dqp->q_mount;
1072         struct xfs_buf          *bp;
1073         struct xfs_disk_dquot   *ddqp;
1074         int                     error;
1075
1076         ASSERT(XFS_DQ_IS_LOCKED(dqp));
1077         ASSERT(!completion_done(&dqp->q_flush));
1078
1079         trace_xfs_dqflush(dqp);
1080
1081         *bpp = NULL;
1082
1083         xfs_qm_dqunpin_wait(dqp);
1084
1085         /*
1086          * This may have been unpinned because the filesystem is shutting
1087          * down forcibly. If that's the case we must not write this dquot
1088          * to disk, because the log record didn't make it to disk.
1089          *
1090          * We also have to remove the log item from the AIL in this case,
1091          * as we wait for an emptry AIL as part of the unmount process.
1092          */
1093         if (XFS_FORCED_SHUTDOWN(mp)) {
1094                 struct xfs_log_item     *lip = &dqp->q_logitem.qli_item;
1095                 dqp->dq_flags &= ~XFS_DQ_DIRTY;
1096
1097                 spin_lock(&mp->m_ail->xa_lock);
1098                 if (lip->li_flags & XFS_LI_IN_AIL)
1099                         xfs_trans_ail_delete(mp->m_ail, lip,
1100                                              SHUTDOWN_CORRUPT_INCORE);
1101                 else
1102                         spin_unlock(&mp->m_ail->xa_lock);
1103                 error = XFS_ERROR(EIO);
1104                 goto out_unlock;
1105         }
1106
1107         /*
1108          * Get the buffer containing the on-disk dquot
1109          */
1110         error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
1111                                    mp->m_quotainfo->qi_dqchunklen, 0, &bp, NULL);
1112         if (error)
1113                 goto out_unlock;
1114
1115         /*
1116          * Calculate the location of the dquot inside the buffer.
1117          */
1118         ddqp = bp->b_addr + dqp->q_bufoffset;
1119
1120         /*
1121          * A simple sanity check in case we got a corrupted dquot..
1122          */
1123         error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
1124                            XFS_QMOPT_DOWARN, "dqflush (incore copy)");
1125         if (error) {
1126                 xfs_buf_relse(bp);
1127                 xfs_dqfunlock(dqp);
1128                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1129                 return XFS_ERROR(EIO);
1130         }
1131
1132         /* This is the only portion of data that needs to persist */
1133         memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
1134
1135         /*
1136          * Clear the dirty field and remember the flush lsn for later use.
1137          */
1138         dqp->dq_flags &= ~XFS_DQ_DIRTY;
1139
1140         xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1141                                         &dqp->q_logitem.qli_item.li_lsn);
1142
1143         /*
1144          * copy the lsn into the on-disk dquot now while we have the in memory
1145          * dquot here. This can't be done later in the write verifier as we
1146          * can't get access to the log item at that point in time.
1147          *
1148          * We also calculate the CRC here so that the on-disk dquot in the
1149          * buffer always has a valid CRC. This ensures there is no possibility
1150          * of a dquot without an up-to-date CRC getting to disk.
1151          */
1152         if (xfs_sb_version_hascrc(&mp->m_sb)) {
1153                 struct xfs_dqblk *dqb = (struct xfs_dqblk *)ddqp;
1154
1155                 dqb->dd_lsn = cpu_to_be64(dqp->q_logitem.qli_item.li_lsn);
1156                 xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
1157                                  XFS_DQUOT_CRC_OFF);
1158         }
1159
1160         /*
1161          * Attach an iodone routine so that we can remove this dquot from the
1162          * AIL and release the flush lock once the dquot is synced to disk.
1163          */
1164         xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1165                                   &dqp->q_logitem.qli_item);
1166
1167         /*
1168          * If the buffer is pinned then push on the log so we won't
1169          * get stuck waiting in the write for too long.
1170          */
1171         if (xfs_buf_ispinned(bp)) {
1172                 trace_xfs_dqflush_force(dqp);
1173                 xfs_log_force(mp, 0);
1174         }
1175
1176         trace_xfs_dqflush_done(dqp);
1177         *bpp = bp;
1178         return 0;
1179
1180 out_unlock:
1181         xfs_dqfunlock(dqp);
1182         return XFS_ERROR(EIO);
1183 }
1184
1185 /*
1186  * Lock two xfs_dquot structures.
1187  *
1188  * To avoid deadlocks we always lock the quota structure with
1189  * the lowerd id first.
1190  */
1191 void
1192 xfs_dqlock2(
1193         xfs_dquot_t     *d1,
1194         xfs_dquot_t     *d2)
1195 {
1196         if (d1 && d2) {
1197                 ASSERT(d1 != d2);
1198                 if (be32_to_cpu(d1->q_core.d_id) >
1199                     be32_to_cpu(d2->q_core.d_id)) {
1200                         mutex_lock(&d2->q_qlock);
1201                         mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1202                 } else {
1203                         mutex_lock(&d1->q_qlock);
1204                         mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1205                 }
1206         } else if (d1) {
1207                 mutex_lock(&d1->q_qlock);
1208         } else if (d2) {
1209                 mutex_lock(&d2->q_qlock);
1210         }
1211 }
1212
1213 int __init
1214 xfs_qm_init(void)
1215 {
1216         xfs_qm_dqzone =
1217                 kmem_zone_init(sizeof(struct xfs_dquot), "xfs_dquot");
1218         if (!xfs_qm_dqzone)
1219                 goto out;
1220
1221         xfs_qm_dqtrxzone =
1222                 kmem_zone_init(sizeof(struct xfs_dquot_acct), "xfs_dqtrx");
1223         if (!xfs_qm_dqtrxzone)
1224                 goto out_free_dqzone;
1225
1226         return 0;
1227
1228 out_free_dqzone:
1229         kmem_zone_destroy(xfs_qm_dqzone);
1230 out:
1231         return -ENOMEM;
1232 }
1233
1234 void
1235 xfs_qm_exit(void)
1236 {
1237         kmem_zone_destroy(xfs_qm_dqtrxzone);
1238         kmem_zone_destroy(xfs_qm_dqzone);
1239 }