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