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_bit.h"
  21 #include "xfs_log.h"
  22 #include "xfs_trans.h"
  23 #include "xfs_sb.h"
  24 #include "xfs_ag.h"
  25 #include "xfs_alloc.h"
  26 #include "xfs_quota.h"
  27 #include "xfs_mount.h"
  28 #include "xfs_bmap_btree.h"
  29 #include "xfs_inode.h"
  30 #include "xfs_bmap.h"
  31 #include "xfs_rtalloc.h"
  32 #include "xfs_error.h"
  33 #include "xfs_itable.h"
  34 #include "xfs_attr.h"
  35 #include "xfs_buf_item.h"
  36 #include "xfs_trans_space.h"
  37 #include "xfs_trans_priv.h"
  38 #include "xfs_qm.h"
  39 #include "xfs_cksum.h"
  40 #include "xfs_trace.h"
  41
  42 /*
  43  * Lock order:
  44  *
  45  * ip->i_lock
  46  *   qi->qi_tree_lock
  47  *     dquot->q_qlock (xfs_dqlock() and friends)
  48  *       dquot->q_flush (xfs_dqflock() and friends)
  49  *       qi->qi_lru_lock
  50  *
  51  * If two dquots need to be locked the order is user before group/project,
  52  * otherwise by the lowest id first, see xfs_dqlock2.
  53  */
  54
  55 #ifdef DEBUG
  56 xfs_buftarg_t *xfs_dqerror_target;
  57 int xfs_do_dqerror;
  58 int xfs_dqreq_num;
  59 int xfs_dqerror_mod = 33;
  60 #endif
  61
  62 struct kmem_zone                *xfs_qm_dqtrxzone;
  63 static struct kmem_zone         *xfs_qm_dqzone;
  64
  65 static struct lock_class_key xfs_dquot_other_class;
  66
  67 /*
  68  * This is called to free all the memory associated with a dquot
  69  */
  70 void
  71 xfs_qm_dqdestroy(
  72         xfs_dquot_t     *dqp)
  73 {
  74         ASSERT(list_empty(&dqp->q_lru));
  75
  76         mutex_destroy(&dqp->q_qlock);
  77         kmem_zone_free(xfs_qm_dqzone, dqp);
  78
  79         XFS_STATS_DEC(xs_qm_dquot);
  80 }
  81
  82 /*
  83  * If default limits are in force, push them into the dquot now.
  84  * We overwrite the dquot limits only if they are zero and this
  85  * is not the root dquot.
  86  */
  87 void
  88 xfs_qm_adjust_dqlimits(
  89         struct xfs_mount        *mp,
  90         struct xfs_dquot        *dq)
  91 {
  92         struct xfs_quotainfo    *q = mp->m_quotainfo;
  93         struct xfs_disk_dquot   *d = &dq->q_core;
  94         int                     prealloc = 0;
  95
  96         ASSERT(d->d_id);
  97
  98         if (q->qi_bsoftlimit && !d->d_blk_softlimit) {
  99                 d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
 100                 prealloc = 1;
 101         }
 102         if (q->qi_bhardlimit && !d->d_blk_hardlimit) {
 103                 d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
 104                 prealloc = 1;
 105         }
 106         if (q->qi_isoftlimit && !d->d_ino_softlimit)
 107                 d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
 108         if (q->qi_ihardlimit && !d->d_ino_hardlimit)
 109                 d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
 110         if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
 111                 d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
 112         if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
 113                 d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
 114
 115         if (prealloc)
 116                 xfs_dquot_set_prealloc_limits(dq);
 117 }
 118
 119 /*
 120  * Check the limits and timers of a dquot and start or reset timers
 121  * if necessary.
 122  * This gets called even when quota enforcement is OFF, which makes our
 123  * life a little less complicated. (We just don't reject any quota
 124  * reservations in that case, when enforcement is off).
 125  * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
 126  * enforcement's off.
 127  * In contrast, warnings are a little different in that they don't
 128  * 'automatically' get started when limits get exceeded.  They do
 129  * get reset to zero, however, when we find the count to be under
 130  * the soft limit (they are only ever set non-zero via userspace).
 131  */
 132 void
 133 xfs_qm_adjust_dqtimers(
 134         xfs_mount_t             *mp,
 135         xfs_disk_dquot_t        *d)
 136 {
 137         ASSERT(d->d_id);
 138
 139 #ifdef DEBUG
 140         if (d->d_blk_hardlimit)
 141                 ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
 142                        be64_to_cpu(d->d_blk_hardlimit));
 143         if (d->d_ino_hardlimit)
 144                 ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
 145                        be64_to_cpu(d->d_ino_hardlimit));
 146         if (d->d_rtb_hardlimit)
 147                 ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
 148                        be64_to_cpu(d->d_rtb_hardlimit));
 149 #endif
 150
 151         if (!d->d_btimer) {
 152                 if ((d->d_blk_softlimit &&
 153                      (be64_to_cpu(d->d_bcount) >
 154                       be64_to_cpu(d->d_blk_softlimit))) ||
 155                     (d->d_blk_hardlimit &&
 156                      (be64_to_cpu(d->d_bcount) >
 157                       be64_to_cpu(d->d_blk_hardlimit)))) {
 158                         d->d_btimer = cpu_to_be32(get_seconds() +
 159                                         mp->m_quotainfo->qi_btimelimit);
 160                 } else {
 161                         d->d_bwarns = 0;
 162                 }
 163         } else {
 164                 if ((!d->d_blk_softlimit ||
 165                      (be64_to_cpu(d->d_bcount) <=
 166                       be64_to_cpu(d->d_blk_softlimit))) &&
 167                     (!d->d_blk_hardlimit ||
 168                     (be64_to_cpu(d->d_bcount) <=
 169                      be64_to_cpu(d->d_blk_hardlimit)))) {
 170                         d->d_btimer = 0;
 171                 }
 172         }
 173
 174         if (!d->d_itimer) {
 175                 if ((d->d_ino_softlimit &&
 176                      (be64_to_cpu(d->d_icount) >
 177                       be64_to_cpu(d->d_ino_softlimit))) ||
 178                     (d->d_ino_hardlimit &&
 179                      (be64_to_cpu(d->d_icount) >
 180                       be64_to_cpu(d->d_ino_hardlimit)))) {
 181                         d->d_itimer = cpu_to_be32(get_seconds() +
 182                                         mp->m_quotainfo->qi_itimelimit);
 183                 } else {
 184                         d->d_iwarns = 0;
 185                 }
 186         } else {
 187                 if ((!d->d_ino_softlimit ||
 188                      (be64_to_cpu(d->d_icount) <=
 189                       be64_to_cpu(d->d_ino_softlimit)))  &&
 190                     (!d->d_ino_hardlimit ||
 191                      (be64_to_cpu(d->d_icount) <=
 192                       be64_to_cpu(d->d_ino_hardlimit)))) {
 193                         d->d_itimer = 0;
 194                 }
 195         }
 196
 197         if (!d->d_rtbtimer) {
 198                 if ((d->d_rtb_softlimit &&
 199                      (be64_to_cpu(d->d_rtbcount) >
 200                       be64_to_cpu(d->d_rtb_softlimit))) ||
 201                     (d->d_rtb_hardlimit &&
 202                      (be64_to_cpu(d->d_rtbcount) >
 203                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 204                         d->d_rtbtimer = cpu_to_be32(get_seconds() +
 205                                         mp->m_quotainfo->qi_rtbtimelimit);
 206                 } else {
 207                         d->d_rtbwarns = 0;
 208                 }
 209         } else {
 210                 if ((!d->d_rtb_softlimit ||
 211                      (be64_to_cpu(d->d_rtbcount) <=
 212                       be64_to_cpu(d->d_rtb_softlimit))) &&
 213                     (!d->d_rtb_hardlimit ||
 214                      (be64_to_cpu(d->d_rtbcount) <=
 215                       be64_to_cpu(d->d_rtb_hardlimit)))) {
 216                         d->d_rtbtimer = 0;
 217                 }
 218         }
 219 }
 220
 221 /*
 222  * initialize a buffer full of dquots and log the whole thing
 223  */
 224 STATIC void
 225 xfs_qm_init_dquot_blk(
 226         xfs_trans_t     *tp,
 227         xfs_mount_t     *mp,
 228         xfs_dqid_t      id,
 229         uint            type,
 230         xfs_buf_t       *bp)
 231 {
 232         struct xfs_quotainfo    *q = mp->m_quotainfo;
 233         xfs_dqblk_t     *d;
 234         int             curid, i;
 235
 236         ASSERT(tp);
 237         ASSERT(xfs_buf_islocked(bp));
 238
 239         d = bp->b_addr;
 240
 241         /*
 242          * ID of the first dquot in the block - id's are zero based.
 243          */
 244         curid = id - (id % q->qi_dqperchunk);
 245         ASSERT(curid >= 0);
 246         memset(d, 0, BBTOB(q->qi_dqchunklen));
 247         for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++) {
 248                 d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 249                 d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 250                 d->dd_diskdq.d_id = cpu_to_be32(curid);
 251                 d->dd_diskdq.d_flags = type;
 252                 if (xfs_sb_version_hascrc(&mp->m_sb))
 253                         uuid_copy(&d->dd_uuid, &mp->m_sb.sb_uuid);
 254         }
 255
 256         xfs_trans_dquot_buf(tp, bp,
 257                             (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
 258                             ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
 259                              XFS_BLF_GDQUOT_BUF)));
 260         xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
 261 }
 262
 263 /*
 264  * Initialize the dynamic speculative preallocation thresholds. The lo/hi
 265  * watermarks correspond to the soft and hard limits by default. If a soft limit
 266  * is not specified, we use 95% of the hard limit.
 267  */
 268 void
 269 xfs_dquot_set_prealloc_limits(struct xfs_dquot *dqp)
 270 {
 271         __uint64_t space;
 272
 273         dqp->q_prealloc_hi_wmark = be64_to_cpu(dqp->q_core.d_blk_hardlimit);
 274         dqp->q_prealloc_lo_wmark = be64_to_cpu(dqp->q_core.d_blk_softlimit);
 275         if (!dqp->q_prealloc_lo_wmark) {
 276                 dqp->q_prealloc_lo_wmark = dqp->q_prealloc_hi_wmark;
 277                 do_div(dqp->q_prealloc_lo_wmark, 100);
 278                 dqp->q_prealloc_lo_wmark *= 95;
 279         }
 280
 281         space = dqp->q_prealloc_hi_wmark;
 282
 283         do_div(space, 100);
 284         dqp->q_low_space[XFS_QLOWSP_1_PCNT] = space;
 285         dqp->q_low_space[XFS_QLOWSP_3_PCNT] = space * 3;
 286         dqp->q_low_space[XFS_QLOWSP_5_PCNT] = space * 5;
 287 }
 288
 289 STATIC void
 290 xfs_dquot_buf_calc_crc(
 291         struct xfs_mount        *mp,
 292         struct xfs_buf          *bp)
 293 {
 294         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 295         int                     i;
 296
 297         if (!xfs_sb_version_hascrc(&mp->m_sb))
 298                 return;
 299
 300         for (i = 0; i < mp->m_quotainfo->qi_dqperchunk; i++, d++) {
 301                 xfs_update_cksum((char *)d, sizeof(struct xfs_dqblk),
 302                                  offsetof(struct xfs_dqblk, dd_crc));
 303         }
 304 }
 305
 306 STATIC bool
 307 xfs_dquot_buf_verify_crc(
 308         struct xfs_mount        *mp,
 309         struct xfs_buf          *bp)
 310 {
 311         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 312         int                     ndquots;
 313         int                     i;
 314
 315         if (!xfs_sb_version_hascrc(&mp->m_sb))
 316                 return true;
 317
 318         /*
 319          * if we are in log recovery, the quota subsystem has not been
 320          * initialised so we have no quotainfo structure. In that case, we need
 321          * to manually calculate the number of dquots in the buffer.
 322          */
 323         if (mp->m_quotainfo)
 324                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 325         else
 326                 ndquots = xfs_qm_calc_dquots_per_chunk(mp,
 327                                         XFS_BB_TO_FSB(mp, bp->b_length));
 328
 329         for (i = 0; i < ndquots; i++, d++) {
 330                 if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
 331                                  offsetof(struct xfs_dqblk, dd_crc)))
 332                         return false;
 333                 if (!uuid_equal(&d->dd_uuid, &mp->m_sb.sb_uuid))
 334                         return false;
 335         }
 336
 337         return true;
 338 }
 339
 340 STATIC bool
 341 xfs_dquot_buf_verify(
 342         struct xfs_mount        *mp,
 343         struct xfs_buf          *bp)
 344 {
 345         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 346         xfs_dqid_t              id = 0;
 347         int                     ndquots;
 348         int                     i;
 349
 350         /*
 351          * if we are in log recovery, the quota subsystem has not been
 352          * initialised so we have no quotainfo structure. In that case, we need
 353          * to manually calculate the number of dquots in the buffer.
 354          */
 355         if (mp->m_quotainfo)
 356                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 357         else
 358                 ndquots = xfs_qm_calc_dquots_per_chunk(mp, bp->b_length);
 359
 360         /*
 361          * On the first read of the buffer, verify that each dquot is valid.
 362          * We don't know what the id of the dquot is supposed to be, just that
 363          * they should be increasing monotonically within the buffer. If the
 364          * first id is corrupt, then it will fail on the second dquot in the
 365          * buffer so corruptions could point to the wrong dquot in this case.
 366          */
 367         for (i = 0; i < ndquots; i++) {
 368                 struct xfs_disk_dquot   *ddq;
 369                 int                     error;
 370
 371                 ddq = &d[i].dd_diskdq;
 372
 373                 if (i == 0)
 374                         id = be32_to_cpu(ddq->d_id);
 375
 376                 error = xfs_qm_dqcheck(mp, ddq, id + i, 0, XFS_QMOPT_DOWARN,
 377                                        "xfs_dquot_buf_verify");
 378                 if (error)
 379                         return false;
 380         }
 381         return true;
 382 }
 383
 384 static void
 385 xfs_dquot_buf_read_verify(
 386         struct xfs_buf  *bp)
 387 {
 388         struct xfs_mount        *mp = bp->b_target->bt_mount;
 389
 390         if (!xfs_dquot_buf_verify_crc(mp, bp) || !xfs_dquot_buf_verify(mp, bp)) {
 391                 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
 392                 xfs_buf_ioerror(bp, EFSCORRUPTED);
 393         }
 394 }
 395
 396 void
 397 xfs_dquot_buf_write_verify(
 398         struct xfs_buf  *bp)
 399 {
 400         struct xfs_mount        *mp = bp->b_target->bt_mount;
 401
 402         if (!xfs_dquot_buf_verify(mp, bp)) {
 403                 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
 404                 xfs_buf_ioerror(bp, EFSCORRUPTED);
 405                 return;
 406         }
 407         xfs_dquot_buf_calc_crc(mp, bp);
 408 }
 409
 410 const struct xfs_buf_ops xfs_dquot_buf_ops = {
 411         .verify_read = xfs_dquot_buf_read_verify,
 412         .verify_write = xfs_dquot_buf_write_verify,
 413 };
 414
 415 /*
 416  * Allocate a block and fill it with dquots.
 417  * This is called when the bmapi finds a hole.
 418  */
 419 STATIC int
 420 xfs_qm_dqalloc(
 421         xfs_trans_t     **tpp,
 422         xfs_mount_t     *mp,
 423         xfs_dquot_t     *dqp,
 424         xfs_inode_t     *quotip,
 425         xfs_fileoff_t   offset_fsb,
 426         xfs_buf_t       **O_bpp)
 427 {
 428         xfs_fsblock_t   firstblock;
 429         xfs_bmap_free_t flist;
 430         xfs_bmbt_irec_t map;
 431         int             nmaps, error, committed;
 432         xfs_buf_t       *bp;
 433         xfs_trans_t     *tp = *tpp;
 434
 435         ASSERT(tp != NULL);
 436
 437         trace_xfs_dqalloc(dqp);
 438
 439         /*
 440          * Initialize the bmap freelist prior to calling bmapi code.
 441          */
 442         xfs_bmap_init(&flist, &firstblock);
 443         xfs_ilock(quotip, XFS_ILOCK_EXCL);
 444         /*
 445          * Return if this type of quotas is turned off while we didn't
 446          * have an inode lock
 447          */
 448         if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
 449                 xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 450                 return (ESRCH);
 451         }
 452
 453         xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
 454         nmaps = 1;
 455         error = xfs_bmapi_write(tp, quotip, offset_fsb,
 456                                 XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
 457                                 &firstblock, XFS_QM_DQALLOC_SPACE_RES(mp),
 458                                 &map, &nmaps, &flist);
 459         if (error)
 460                 goto error0;
 461         ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
 462         ASSERT(nmaps == 1);
 463         ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 464                (map.br_startblock != HOLESTARTBLOCK));
 465
 466         /*
 467          * Keep track of the blkno to save a lookup later
 468          */
 469         dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 470
 471         /* now we can just get the buffer (there's nothing to read yet) */
 472         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
 473                                dqp->q_blkno,
 474                                mp->m_quotainfo->qi_dqchunklen,
 475                                0);
 476
 477         error = xfs_buf_geterror(bp);
 478         if (error)
 479                 goto error1;
 480         bp->b_ops = &xfs_dquot_buf_ops;
 481
 482         /*
 483          * Make a chunk of dquots out of this buffer and log
 484          * the entire thing.
 485          */
 486         xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
 487                               dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
 488
 489         /*
 490          * xfs_bmap_finish() may commit the current transaction and
 491          * start a second transaction if the freelist is not empty.
 492          *
 493          * Since we still want to modify this buffer, we need to
 494          * ensure that the buffer is not released on commit of
 495          * the first transaction and ensure the buffer is added to the
 496          * second transaction.
 497          *
 498          * If there is only one transaction then don't stop the buffer
 499          * from being released when it commits later on.
 500          */
 501
 502         xfs_trans_bhold(tp, bp);
 503
 504         if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
 505                 goto error1;
 506         }
 507
 508         if (committed) {
 509                 tp = *tpp;
 510                 xfs_trans_bjoin(tp, bp);
 511         } else {
 512                 xfs_trans_bhold_release(tp, bp);
 513         }
 514
 515         *O_bpp = bp;
 516         return 0;
 517
 518       error1:
 519         xfs_bmap_cancel(&flist);
 520       error0:
 521         xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 522
 523         return (error);
 524 }
 525 STATIC int
 526 xfs_qm_dqrepair(
 527         struct xfs_mount        *mp,
 528         struct xfs_trans        *tp,
 529         struct xfs_dquot        *dqp,
 530         xfs_dqid_t              firstid,
 531         struct xfs_buf          **bpp)
 532 {
 533         int                     error;
 534         struct xfs_disk_dquot   *ddq;
 535         struct xfs_dqblk        *d;
 536         int                     i;
 537
 538         /*
 539          * Read the buffer without verification so we get the corrupted
 540          * buffer returned to us. make sure we verify it on write, though.
 541          */
 542         error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, dqp->q_blkno,
 543                                    mp->m_quotainfo->qi_dqchunklen,
 544                                    0, bpp, NULL);
 545
 546         if (error) {
 547                 ASSERT(*bpp == NULL);
 548                 return XFS_ERROR(error);
 549         }
 550         (*bpp)->b_ops = &xfs_dquot_buf_ops;
 551
 552         ASSERT(xfs_buf_islocked(*bpp));
 553         d = (struct xfs_dqblk *)(*bpp)->b_addr;
 554
 555         /* Do the actual repair of dquots in this buffer */
 556         for (i = 0; i < mp->m_quotainfo->qi_dqperchunk; i++) {
 557                 ddq = &d[i].dd_diskdq;
 558                 error = xfs_qm_dqcheck(mp, ddq, firstid + i,
 559                                        dqp->dq_flags & XFS_DQ_ALLTYPES,
 560                                        XFS_QMOPT_DQREPAIR, "xfs_qm_dqrepair");
 561                 if (error) {
 562                         /* repair failed, we're screwed */
 563                         xfs_trans_brelse(tp, *bpp);
 564                         return XFS_ERROR(EIO);
 565                 }
 566         }
 567
 568         return 0;
 569 }
 570
 571 /*
 572  * Maps a dquot to the buffer containing its on-disk version.
 573  * This returns a ptr to the buffer containing the on-disk dquot
 574  * in the bpp param, and a ptr to the on-disk dquot within that buffer
 575  */
 576 STATIC int
 577 xfs_qm_dqtobp(
 578         xfs_trans_t             **tpp,
 579         xfs_dquot_t             *dqp,
 580         xfs_disk_dquot_t        **O_ddpp,
 581         xfs_buf_t               **O_bpp,
 582         uint                    flags)
 583 {
 584         xfs_bmbt_irec_t map;
 585         int             nmaps = 1, error;
 586         xfs_buf_t       *bp;
 587         xfs_inode_t     *quotip = XFS_DQ_TO_QIP(dqp);
 588         xfs_mount_t     *mp = dqp->q_mount;
 589         xfs_dqid_t      id = be32_to_cpu(dqp->q_core.d_id);
 590         xfs_trans_t     *tp = (tpp ? *tpp : NULL);
 591
 592         dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
 593
 594         xfs_ilock(quotip, XFS_ILOCK_SHARED);
 595         if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
 596                 /*
 597                  * Return if this type of quotas is turned off while we
 598                  * didn't have the quota inode lock.
 599                  */
 600                 xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 601                 return ESRCH;
 602         }
 603
 604         /*
 605          * Find the block map; no allocations yet
 606          */
 607         error = xfs_bmapi_read(quotip, dqp->q_fileoffset,
 608                                XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
 609
 610         xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 611         if (error)
 612                 return error;
 613
 614         ASSERT(nmaps == 1);
 615         ASSERT(map.br_blockcount == 1);
 616
 617         /*
 618          * Offset of dquot in the (fixed sized) dquot chunk.
 619          */
 620         dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
 621                 sizeof(xfs_dqblk_t);
 622
 623         ASSERT(map.br_startblock != DELAYSTARTBLOCK);
 624         if (map.br_startblock == HOLESTARTBLOCK) {
 625                 /*
 626                  * We don't allocate unless we're asked to
 627                  */
 628                 if (!(flags & XFS_QMOPT_DQALLOC))
 629                         return ENOENT;
 630
 631                 ASSERT(tp);
 632                 error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
 633                                         dqp->q_fileoffset, &bp);
 634                 if (error)
 635                         return error;
 636                 tp = *tpp;
 637         } else {
 638                 trace_xfs_dqtobp_read(dqp);
 639
 640                 /*
 641                  * store the blkno etc so that we don't have to do the
 642                  * mapping all the time
 643                  */
 644                 dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 645
 646                 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 647                                            dqp->q_blkno,
 648                                            mp->m_quotainfo->qi_dqchunklen,
 649                                            0, &bp, &xfs_dquot_buf_ops);
 650
 651                 if (error == EFSCORRUPTED && (flags & XFS_QMOPT_DQREPAIR)) {
 652                         xfs_dqid_t firstid = (xfs_dqid_t)map.br_startoff *
 653                                                 mp->m_quotainfo->qi_dqperchunk;
 654                         ASSERT(bp == NULL);
 655                         error = xfs_qm_dqrepair(mp, tp, dqp, firstid, &bp);
 656                 }
 657
 658                 if (error) {
 659                         ASSERT(bp == NULL);
 660                         return XFS_ERROR(error);
 661                 }
 662         }
 663
 664         ASSERT(xfs_buf_islocked(bp));
 665         *O_bpp = bp;
 666         *O_ddpp = bp->b_addr + dqp->q_bufoffset;
 667
 668         return (0);
 669 }
 670
 671
 672 /*
 673  * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
 674  * and release the buffer immediately.
 675  *
 676  * If XFS_QMOPT_DQALLOC is set, allocate a dquot on disk if it needed.
 677  */
 678 int
 679 xfs_qm_dqread(
 680         struct xfs_mount        *mp,
 681         xfs_dqid_t              id,
 682         uint                    type,
 683         uint                    flags,
 684         struct xfs_dquot        **O_dqpp)
 685 {
 686         struct xfs_dquot        *dqp;
 687         struct xfs_disk_dquot   *ddqp;
 688         struct xfs_buf          *bp;
 689         struct xfs_trans        *tp = NULL;
 690         int                     error;
 691         int                     cancelflags = 0;
 692
 693
 694         dqp = kmem_zone_zalloc(xfs_qm_dqzone, KM_SLEEP);
 695
 696         dqp->dq_flags = type;
 697         dqp->q_core.d_id = cpu_to_be32(id);
 698         dqp->q_mount = mp;
 699         INIT_LIST_HEAD(&dqp->q_lru);
 700         mutex_init(&dqp->q_qlock);
 701         init_waitqueue_head(&dqp->q_pinwait);
 702
 703         /*
 704          * Because we want to use a counting completion, complete
 705          * the flush completion once to allow a single access to
 706          * the flush completion without blocking.
 707          */
 708         init_completion(&dqp->q_flush);
 709         complete(&dqp->q_flush);
 710
 711         /*
 712          * Make sure group quotas have a different lock class than user
 713          * quotas.
 714          */
 715         if (!(type & XFS_DQ_USER))
 716                 lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
 717
 718         XFS_STATS_INC(xs_qm_dquot);
 719
 720         trace_xfs_dqread(dqp);
 721
 722         if (flags & XFS_QMOPT_DQALLOC) {
 723                 tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
 724                 error = xfs_trans_reserve(tp, XFS_QM_DQALLOC_SPACE_RES(mp),
 725                                           XFS_QM_DQALLOC_LOG_RES(mp), 0,
 726                                           XFS_TRANS_PERM_LOG_RES,
 727                                           XFS_WRITE_LOG_COUNT);
 728                 if (error)
 729                         goto error1;
 730                 cancelflags = XFS_TRANS_RELEASE_LOG_RES;
 731         }
 732
 733         /*
 734          * get a pointer to the on-disk dquot and the buffer containing it
 735          * dqp already knows its own type (GROUP/USER).
 736          */
 737         error = xfs_qm_dqtobp(&tp, dqp, &ddqp, &bp, flags);
 738         if (error) {
 739                 /*
 740                  * This can happen if quotas got turned off (ESRCH),
 741                  * or if the dquot didn't exist on disk and we ask to
 742                  * allocate (ENOENT).
 743                  */
 744                 trace_xfs_dqread_fail(dqp);
 745                 cancelflags |= XFS_TRANS_ABORT;
 746                 goto error1;
 747         }
 748
 749         /* copy everything from disk dquot to the incore dquot */
 750         memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
 751         xfs_qm_dquot_logitem_init(dqp);
 752
 753         /*
 754          * Reservation counters are defined as reservation plus current usage
 755          * to avoid having to add every time.
 756          */
 757         dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
 758         dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
 759         dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
 760
 761         /* initialize the dquot speculative prealloc thresholds */
 762         xfs_dquot_set_prealloc_limits(dqp);
 763
 764         /* Mark the buf so that this will stay incore a little longer */
 765         xfs_buf_set_ref(bp, XFS_DQUOT_REF);
 766
 767         /*
 768          * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
 769          * So we need to release with xfs_trans_brelse().
 770          * The strategy here is identical to that of inodes; we lock
 771          * the dquot in xfs_qm_dqget() before making it accessible to
 772          * others. This is because dquots, like inodes, need a good level of
 773          * concurrency, and we don't want to take locks on the entire buffers
 774          * for dquot accesses.
 775          * Note also that the dquot buffer may even be dirty at this point, if
 776          * this particular dquot was repaired. We still aren't afraid to
 777          * brelse it because we have the changes incore.
 778          */
 779         ASSERT(xfs_buf_islocked(bp));
 780         xfs_trans_brelse(tp, bp);
 781
 782         if (tp) {
 783                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 784                 if (error)
 785                         goto error0;
 786         }
 787
 788         *O_dqpp = dqp;
 789         return error;
 790
 791 error1:
 792         if (tp)
 793                 xfs_trans_cancel(tp, cancelflags);
 794 error0:
 795         xfs_qm_dqdestroy(dqp);
 796         *O_dqpp = NULL;
 797         return error;
 798 }
 799
 800 /*
 801  * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
 802  * a locked dquot, doing an allocation (if requested) as needed.
 803  * When both an inode and an id are given, the inode's id takes precedence.
 804  * That is, if the id changes while we don't hold the ilock inside this
 805  * function, the new dquot is returned, not necessarily the one requested
 806  * in the id argument.
 807  */
 808 int
 809 xfs_qm_dqget(
 810         xfs_mount_t     *mp,
 811         xfs_inode_t     *ip,      /* locked inode (optional) */
 812         xfs_dqid_t      id,       /* uid/projid/gid depending on type */
 813         uint            type,     /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
 814         uint            flags,    /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
 815         xfs_dquot_t     **O_dqpp) /* OUT : locked incore dquot */
 816 {
 817         struct xfs_quotainfo    *qi = mp->m_quotainfo;
 818         struct radix_tree_root *tree = XFS_DQUOT_TREE(qi, type);
 819         struct xfs_dquot        *dqp;
 820         int                     error;
 821
 822         ASSERT(XFS_IS_QUOTA_RUNNING(mp));
 823         if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
 824             (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
 825             (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
 826                 return (ESRCH);
 827         }
 828
 829 #ifdef DEBUG
 830         if (xfs_do_dqerror) {
 831                 if ((xfs_dqerror_target == mp->m_ddev_targp) &&
 832                     (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
 833                         xfs_debug(mp, "Returning error in dqget");
 834                         return (EIO);
 835                 }
 836         }
 837
 838         ASSERT(type == XFS_DQ_USER ||
 839                type == XFS_DQ_PROJ ||
 840                type == XFS_DQ_GROUP);
 841         if (ip) {
 842                 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 843                 ASSERT(xfs_inode_dquot(ip, type) == NULL);
 844         }
 845 #endif
 846
 847 restart:
 848         mutex_lock(&qi->qi_tree_lock);
 849         dqp = radix_tree_lookup(tree, id);
 850         if (dqp) {
 851                 xfs_dqlock(dqp);
 852                 if (dqp->dq_flags & XFS_DQ_FREEING) {
 853                         xfs_dqunlock(dqp);
 854                         mutex_unlock(&qi->qi_tree_lock);
 855                         trace_xfs_dqget_freeing(dqp);
 856                         delay(1);
 857                         goto restart;
 858                 }
 859
 860                 dqp->q_nrefs++;
 861                 mutex_unlock(&qi->qi_tree_lock);
 862
 863                 trace_xfs_dqget_hit(dqp);
 864                 XFS_STATS_INC(xs_qm_dqcachehits);
 865                 *O_dqpp = dqp;
 866                 return 0;
 867         }
 868         mutex_unlock(&qi->qi_tree_lock);
 869         XFS_STATS_INC(xs_qm_dqcachemisses);
 870
 871         /*
 872          * Dquot cache miss. We don't want to keep the inode lock across
 873          * a (potential) disk read. Also we don't want to deal with the lock
 874          * ordering between quotainode and this inode. OTOH, dropping the inode
 875          * lock here means dealing with a chown that can happen before
 876          * we re-acquire the lock.
 877          */
 878         if (ip)
 879                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 880
 881         error = xfs_qm_dqread(mp, id, type, flags, &dqp);
 882
 883         if (ip)
 884                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 885
 886         if (error)
 887                 return error;
 888
 889         if (ip) {
 890                 /*
 891                  * A dquot could be attached to this inode by now, since
 892                  * we had dropped the ilock.
 893                  */
 894                 if (xfs_this_quota_on(mp, type)) {
 895                         struct xfs_dquot        *dqp1;
 896
 897                         dqp1 = xfs_inode_dquot(ip, type);
 898                         if (dqp1) {
 899                                 xfs_qm_dqdestroy(dqp);
 900                                 dqp = dqp1;
 901                                 xfs_dqlock(dqp);
 902                                 goto dqret;
 903                         }
 904                 } else {
 905                         /* inode stays locked on return */
 906                         xfs_qm_dqdestroy(dqp);
 907                         return XFS_ERROR(ESRCH);
 908                 }
 909         }
 910
 911         mutex_lock(&qi->qi_tree_lock);
 912         error = -radix_tree_insert(tree, id, dqp);
 913         if (unlikely(error)) {
 914                 WARN_ON(error != EEXIST);
 915
 916                 /*
 917                  * Duplicate found. Just throw away the new dquot and start
 918                  * over.
 919                  */
 920                 mutex_unlock(&qi->qi_tree_lock);
 921                 trace_xfs_dqget_dup(dqp);
 922                 xfs_qm_dqdestroy(dqp);
 923                 XFS_STATS_INC(xs_qm_dquot_dups);
 924                 goto restart;
 925         }
 926
 927         /*
 928          * We return a locked dquot to the caller, with a reference taken
 929          */
 930         xfs_dqlock(dqp);
 931         dqp->q_nrefs = 1;
 932
 933         qi->qi_dquots++;
 934         mutex_unlock(&qi->qi_tree_lock);
 935
 936  dqret:
 937         ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
 938         trace_xfs_dqget_miss(dqp);
 939         *O_dqpp = dqp;
 940         return (0);
 941 }
 942
 943
 944 STATIC void
 945 xfs_qm_dqput_final(
 946         struct xfs_dquot        *dqp)
 947 {
 948         struct xfs_quotainfo    *qi = dqp->q_mount->m_quotainfo;
 949         struct xfs_dquot        *gdqp;
 950
 951         trace_xfs_dqput_free(dqp);
 952
 953         mutex_lock(&qi->qi_lru_lock);
 954         if (list_empty(&dqp->q_lru)) {
 955                 list_add_tail(&dqp->q_lru, &qi->qi_lru_list);
 956                 qi->qi_lru_count++;
 957                 XFS_STATS_INC(xs_qm_dquot_unused);
 958         }
 959         mutex_unlock(&qi->qi_lru_lock);
 960
 961         /*
 962          * If we just added a udquot to the freelist, then we want to release
 963          * the gdquot reference that it (probably) has. Otherwise it'll keep
 964          * the gdquot from getting reclaimed.
 965          */
 966         gdqp = dqp->q_gdquot;
 967         if (gdqp) {
 968                 xfs_dqlock(gdqp);
 969                 dqp->q_gdquot = NULL;
 970         }
 971         xfs_dqunlock(dqp);
 972
 973         /*
 974          * If we had a group quota hint, release it now.
 975          */
 976         if (gdqp)
 977                 xfs_qm_dqput(gdqp);
 978 }
 979
 980 /*
 981  * Release a reference to the dquot (decrement ref-count) and unlock it.
 982  *
 983  * If there is a group quota attached to this dquot, carefully release that
 984  * too without tripping over deadlocks'n'stuff.
 985  */
 986 void
 987 xfs_qm_dqput(
 988         struct xfs_dquot        *dqp)
 989 {
 990         ASSERT(dqp->q_nrefs > 0);
 991         ASSERT(XFS_DQ_IS_LOCKED(dqp));
 992
 993         trace_xfs_dqput(dqp);
 994
 995         if (--dqp->q_nrefs > 0)
 996                 xfs_dqunlock(dqp);
 997         else
 998                 xfs_qm_dqput_final(dqp);
 999 }
1000
1001 /*
1002  * Release a dquot. Flush it if dirty, then dqput() it.
1003  * dquot must not be locked.
1004  */
1005 void
1006 xfs_qm_dqrele(
1007         xfs_dquot_t     *dqp)
1008 {
1009         if (!dqp)
1010                 return;
1011
1012         trace_xfs_dqrele(dqp);
1013
1014         xfs_dqlock(dqp);
1015         /*
1016          * We don't care to flush it if the dquot is dirty here.
1017          * That will create stutters that we want to avoid.
1018          * Instead we do a delayed write when we try to reclaim
1019          * a dirty dquot. Also xfs_sync will take part of the burden...
1020          */
1021         xfs_qm_dqput(dqp);
1022 }
1023
1024 /*
1025  * This is the dquot flushing I/O completion routine.  It is called
1026  * from interrupt level when the buffer containing the dquot is
1027  * flushed to disk.  It is responsible for removing the dquot logitem
1028  * from the AIL if it has not been re-logged, and unlocking the dquot's
1029  * flush lock. This behavior is very similar to that of inodes..
1030  */
1031 STATIC void
1032 xfs_qm_dqflush_done(
1033         struct xfs_buf          *bp,
1034         struct xfs_log_item     *lip)
1035 {
1036         xfs_dq_logitem_t        *qip = (struct xfs_dq_logitem *)lip;
1037         xfs_dquot_t             *dqp = qip->qli_dquot;
1038         struct xfs_ail          *ailp = lip->li_ailp;
1039
1040         /*
1041          * We only want to pull the item from the AIL if its
1042          * location in the log has not changed since we started the flush.
1043          * Thus, we only bother if the dquot's lsn has
1044          * not changed. First we check the lsn outside the lock
1045          * since it's cheaper, and then we recheck while
1046          * holding the lock before removing the dquot from the AIL.
1047          */
1048         if ((lip->li_flags & XFS_LI_IN_AIL) &&
1049             lip->li_lsn == qip->qli_flush_lsn) {
1050
1051                 /* xfs_trans_ail_delete() drops the AIL lock. */
1052                 spin_lock(&ailp->xa_lock);
1053                 if (lip->li_lsn == qip->qli_flush_lsn)
1054                         xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE);
1055                 else
1056                         spin_unlock(&ailp->xa_lock);
1057         }
1058
1059         /*
1060          * Release the dq's flush lock since we're done with it.
1061          */
1062         xfs_dqfunlock(dqp);
1063 }
1064
1065 /*
1066  * Write a modified dquot to disk.
1067  * The dquot must be locked and the flush lock too taken by caller.
1068  * The flush lock will not be unlocked until the dquot reaches the disk,
1069  * but the dquot is free to be unlocked and modified by the caller
1070  * in the interim. Dquot is still locked on return. This behavior is
1071  * identical to that of inodes.
1072  */
1073 int
1074 xfs_qm_dqflush(
1075         struct xfs_dquot        *dqp,
1076         struct xfs_buf          **bpp)
1077 {
1078         struct xfs_mount        *mp = dqp->q_mount;
1079         struct xfs_buf          *bp;
1080         struct xfs_disk_dquot   *ddqp;
1081         int                     error;
1082
1083         ASSERT(XFS_DQ_IS_LOCKED(dqp));
1084         ASSERT(!completion_done(&dqp->q_flush));
1085
1086         trace_xfs_dqflush(dqp);
1087
1088         *bpp = NULL;
1089
1090         xfs_qm_dqunpin_wait(dqp);
1091
1092         /*
1093          * This may have been unpinned because the filesystem is shutting
1094          * down forcibly. If that's the case we must not write this dquot
1095          * to disk, because the log record didn't make it to disk.
1096          *
1097          * We also have to remove the log item from the AIL in this case,
1098          * as we wait for an emptry AIL as part of the unmount process.
1099          */
1100         if (XFS_FORCED_SHUTDOWN(mp)) {
1101                 struct xfs_log_item     *lip = &dqp->q_logitem.qli_item;
1102                 dqp->dq_flags &= ~XFS_DQ_DIRTY;
1103
1104                 spin_lock(&mp->m_ail->xa_lock);
1105                 if (lip->li_flags & XFS_LI_IN_AIL)
1106                         xfs_trans_ail_delete(mp->m_ail, lip,
1107                                              SHUTDOWN_CORRUPT_INCORE);
1108                 else
1109                         spin_unlock(&mp->m_ail->xa_lock);
1110                 error = XFS_ERROR(EIO);
1111                 goto out_unlock;
1112         }
1113
1114         /*
1115          * Get the buffer containing the on-disk dquot
1116          */
1117         error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
1118                                    mp->m_quotainfo->qi_dqchunklen, 0, &bp, NULL);
1119         if (error)
1120                 goto out_unlock;
1121
1122         /*
1123          * Calculate the location of the dquot inside the buffer.
1124          */
1125         ddqp = bp->b_addr + dqp->q_bufoffset;
1126
1127         /*
1128          * A simple sanity check in case we got a corrupted dquot..
1129          */
1130         error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
1131                            XFS_QMOPT_DOWARN, "dqflush (incore copy)");
1132         if (error) {
1133                 xfs_buf_relse(bp);
1134                 xfs_dqfunlock(dqp);
1135                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1136                 return XFS_ERROR(EIO);
1137         }
1138
1139         /* This is the only portion of data that needs to persist */
1140         memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
1141
1142         /*
1143          * Clear the dirty field and remember the flush lsn for later use.
1144          */
1145         dqp->dq_flags &= ~XFS_DQ_DIRTY;
1146
1147         xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1148                                         &dqp->q_logitem.qli_item.li_lsn);
1149
1150         /*
1151          * copy the lsn into the on-disk dquot now while we have the in memory
1152          * dquot here. This can't be done later in the write verifier as we
1153          * can't get access to the log item at that point in time.
1154          */
1155         if (xfs_sb_version_hascrc(&mp->m_sb)) {
1156                 struct xfs_dqblk *dqb = (struct xfs_dqblk *)ddqp;
1157
1158                 dqb->dd_lsn = cpu_to_be64(dqp->q_logitem.qli_item.li_lsn);
1159         }
1160
1161         /*
1162          * Attach an iodone routine so that we can remove this dquot from the
1163          * AIL and release the flush lock once the dquot is synced to disk.
1164          */
1165         xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1166                                   &dqp->q_logitem.qli_item);
1167
1168         /*
1169          * If the buffer is pinned then push on the log so we won't
1170          * get stuck waiting in the write for too long.
1171          */
1172         if (xfs_buf_ispinned(bp)) {
1173                 trace_xfs_dqflush_force(dqp);
1174                 xfs_log_force(mp, 0);
1175         }
1176
1177         trace_xfs_dqflush_done(dqp);
1178         *bpp = bp;
1179         return 0;
1180
1181 out_unlock:
1182         xfs_dqfunlock(dqp);
1183         return XFS_ERROR(EIO);
1184 }
1185
1186 /*
1187  * Lock two xfs_dquot structures.
1188  *
1189  * To avoid deadlocks we always lock the quota structure with
1190  * the lowerd id first.
1191  */
1192 void
1193 xfs_dqlock2(
1194         xfs_dquot_t     *d1,
1195         xfs_dquot_t     *d2)
1196 {
1197         if (d1 && d2) {
1198                 ASSERT(d1 != d2);
1199                 if (be32_to_cpu(d1->q_core.d_id) >
1200                     be32_to_cpu(d2->q_core.d_id)) {
1201                         mutex_lock(&d2->q_qlock);
1202                         mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1203                 } else {
1204                         mutex_lock(&d1->q_qlock);
1205                         mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1206                 }
1207         } else if (d1) {
1208                 mutex_lock(&d1->q_qlock);
1209         } else if (d2) {
1210                 mutex_lock(&d2->q_qlock);
1211         }
1212 }
1213
1214 int __init
1215 xfs_qm_init(void)
1216 {
1217         xfs_qm_dqzone =
1218                 kmem_zone_init(sizeof(struct xfs_dquot), "xfs_dquot");
1219         if (!xfs_qm_dqzone)
1220                 goto out;
1221
1222         xfs_qm_dqtrxzone =
1223                 kmem_zone_init(sizeof(struct xfs_dquot_acct), "xfs_dqtrx");
1224         if (!xfs_qm_dqtrxzone)
1225                 goto out_free_dqzone;
1226
1227         return 0;
1228
1229 out_free_dqzone:
1230         kmem_zone_destroy(xfs_qm_dqzone);
1231 out:
1232         return -ENOMEM;
1233 }
1234
1235 void
1236 xfs_qm_exit(void)
1237 {
1238         kmem_zone_destroy(xfs_qm_dqtrxzone);
1239         kmem_zone_destroy(xfs_qm_dqzone);
1240 }