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 new ID is within the current chunk, advancing it sufficed */
 714         if (next_id % mp->m_quotainfo->qi_dqperchunk) {
 715                 *id = next_id;
 716                 return 0;
 717         }
 718
 719         /* Nope, next_id is now past the current chunk, so find the next one */
 720         start = (xfs_fsblock_t)next_id / mp->m_quotainfo->qi_dqperchunk;
 721
 722         quotip = xfs_quota_inode(mp, type);
 723         lock = xfs_ilock_data_map_shared(quotip);
 724
 725         offset = __xfs_seek_hole_data(VFS_I(quotip), XFS_FSB_TO_B(mp, start),
 726                                       eof, SEEK_DATA);
 727         if (offset < 0)
 728                 error = offset;
 729
 730         xfs_iunlock(quotip, lock);
 731
 732         /* -ENXIO is essentially "no more data" */
 733         if (error)
 734                 return (error == -ENXIO ? -ENOENT: error);
 735
 736         /* Convert next data offset back to a quota id */
 737         *id = XFS_B_TO_FSB(mp, offset) * mp->m_quotainfo->qi_dqperchunk;
 738         return 0;
 739 }
 740
 741 /*
 742  * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
 743  * a locked dquot, doing an allocation (if requested) as needed.
 744  * When both an inode and an id are given, the inode's id takes precedence.
 745  * That is, if the id changes while we don't hold the ilock inside this
 746  * function, the new dquot is returned, not necessarily the one requested
 747  * in the id argument.
 748  */
 749 int
 750 xfs_qm_dqget(
 751         xfs_mount_t     *mp,
 752         xfs_inode_t     *ip,      /* locked inode (optional) */
 753         xfs_dqid_t      id,       /* uid/projid/gid depending on type */
 754         uint            type,     /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
 755         uint            flags,    /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
 756         xfs_dquot_t     **O_dqpp) /* OUT : locked incore dquot */
 757 {
 758         struct xfs_quotainfo    *qi = mp->m_quotainfo;
 759         struct radix_tree_root *tree = xfs_dquot_tree(qi, type);
 760         struct xfs_dquot        *dqp;
 761         loff_t                  eof = 0;
 762         int                     error;
 763
 764         ASSERT(XFS_IS_QUOTA_RUNNING(mp));
 765         if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
 766             (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
 767             (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
 768                 return -ESRCH;
 769         }
 770
 771 #ifdef DEBUG
 772         if (xfs_do_dqerror) {
 773                 if ((xfs_dqerror_target == mp->m_ddev_targp) &&
 774                     (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
 775                         xfs_debug(mp, "Returning error in dqget");
 776                         return -EIO;
 777                 }
 778         }
 779
 780         ASSERT(type == XFS_DQ_USER ||
 781                type == XFS_DQ_PROJ ||
 782                type == XFS_DQ_GROUP);
 783         if (ip) {
 784                 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 785                 ASSERT(xfs_inode_dquot(ip, type) == NULL);
 786         }
 787 #endif
 788
 789         /* Get the end of the quota file if we need it */
 790         if (flags & XFS_QMOPT_DQNEXT) {
 791                 struct xfs_inode        *quotip;
 792                 xfs_fileoff_t           last;
 793                 uint                    lock_mode;
 794
 795                 quotip = xfs_quota_inode(mp, type);
 796                 lock_mode = xfs_ilock_data_map_shared(quotip);
 797                 error = xfs_bmap_last_offset(quotip, &last, XFS_DATA_FORK);
 798                 xfs_iunlock(quotip, lock_mode);
 799                 if (error)
 800                         return error;
 801                 eof = XFS_FSB_TO_B(mp, last);
 802         }
 803
 804 restart:
 805         mutex_lock(&qi->qi_tree_lock);
 806         dqp = radix_tree_lookup(tree, id);
 807         if (dqp) {
 808                 xfs_dqlock(dqp);
 809                 if (dqp->dq_flags & XFS_DQ_FREEING) {
 810                         xfs_dqunlock(dqp);
 811                         mutex_unlock(&qi->qi_tree_lock);
 812                         trace_xfs_dqget_freeing(dqp);
 813                         delay(1);
 814                         goto restart;
 815                 }
 816
 817                 /* uninit / unused quota found in radix tree, keep looking  */
 818                 if (flags & XFS_QMOPT_DQNEXT) {
 819                         if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) {
 820                                 xfs_dqunlock(dqp);
 821                                 mutex_unlock(&qi->qi_tree_lock);
 822                                 error = xfs_dq_get_next_id(mp, type, &id, eof);
 823                                 if (error)
 824                                         return error;
 825                                 goto restart;
 826                         }
 827                 }
 828
 829                 dqp->q_nrefs++;
 830                 mutex_unlock(&qi->qi_tree_lock);
 831
 832                 trace_xfs_dqget_hit(dqp);
 833                 XFS_STATS_INC(mp, xs_qm_dqcachehits);
 834                 *O_dqpp = dqp;
 835                 return 0;
 836         }
 837         mutex_unlock(&qi->qi_tree_lock);
 838         XFS_STATS_INC(mp, xs_qm_dqcachemisses);
 839
 840         /*
 841          * Dquot cache miss. We don't want to keep the inode lock across
 842          * a (potential) disk read. Also we don't want to deal with the lock
 843          * ordering between quotainode and this inode. OTOH, dropping the inode
 844          * lock here means dealing with a chown that can happen before
 845          * we re-acquire the lock.
 846          */
 847         if (ip)
 848                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 849
 850         error = xfs_qm_dqread(mp, id, type, flags, &dqp);
 851
 852         if (ip)
 853                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 854
 855         /* If we are asked to find next active id, keep looking */
 856         if (error == -ENOENT && (flags & XFS_QMOPT_DQNEXT)) {
 857                 error = xfs_dq_get_next_id(mp, type, &id, eof);
 858                 if (!error)
 859                         goto restart;
 860         }
 861
 862         if (error)
 863                 return error;
 864
 865         if (ip) {
 866                 /*
 867                  * A dquot could be attached to this inode by now, since
 868                  * we had dropped the ilock.
 869                  */
 870                 if (xfs_this_quota_on(mp, type)) {
 871                         struct xfs_dquot        *dqp1;
 872
 873                         dqp1 = xfs_inode_dquot(ip, type);
 874                         if (dqp1) {
 875                                 xfs_qm_dqdestroy(dqp);
 876                                 dqp = dqp1;
 877                                 xfs_dqlock(dqp);
 878                                 goto dqret;
 879                         }
 880                 } else {
 881                         /* inode stays locked on return */
 882                         xfs_qm_dqdestroy(dqp);
 883                         return -ESRCH;
 884                 }
 885         }
 886
 887         mutex_lock(&qi->qi_tree_lock);
 888         error = radix_tree_insert(tree, id, dqp);
 889         if (unlikely(error)) {
 890                 WARN_ON(error != -EEXIST);
 891
 892                 /*
 893                  * Duplicate found. Just throw away the new dquot and start
 894                  * over.
 895                  */
 896                 mutex_unlock(&qi->qi_tree_lock);
 897                 trace_xfs_dqget_dup(dqp);
 898                 xfs_qm_dqdestroy(dqp);
 899                 XFS_STATS_INC(mp, xs_qm_dquot_dups);
 900                 goto restart;
 901         }
 902
 903         /*
 904          * We return a locked dquot to the caller, with a reference taken
 905          */
 906         xfs_dqlock(dqp);
 907         dqp->q_nrefs = 1;
 908
 909         qi->qi_dquots++;
 910         mutex_unlock(&qi->qi_tree_lock);
 911
 912         /* If we are asked to find next active id, keep looking */
 913         if (flags & XFS_QMOPT_DQNEXT) {
 914                 if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) {
 915                         xfs_qm_dqput(dqp);
 916                         error = xfs_dq_get_next_id(mp, type, &id, eof);
 917                         if (error)
 918                                 return error;
 919                         goto restart;
 920                 }
 921         }
 922
 923  dqret:
 924         ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
 925         trace_xfs_dqget_miss(dqp);
 926         *O_dqpp = dqp;
 927         return 0;
 928 }
 929
 930 /*
 931  * Release a reference to the dquot (decrement ref-count) and unlock it.
 932  *
 933  * If there is a group quota attached to this dquot, carefully release that
 934  * too without tripping over deadlocks'n'stuff.
 935  */
 936 void
 937 xfs_qm_dqput(
 938         struct xfs_dquot        *dqp)
 939 {
 940         ASSERT(dqp->q_nrefs > 0);
 941         ASSERT(XFS_DQ_IS_LOCKED(dqp));
 942
 943         trace_xfs_dqput(dqp);
 944
 945         if (--dqp->q_nrefs == 0) {
 946                 struct xfs_quotainfo    *qi = dqp->q_mount->m_quotainfo;
 947                 trace_xfs_dqput_free(dqp);
 948
 949                 if (list_lru_add(&qi->qi_lru, &dqp->q_lru))
 950                         XFS_STATS_INC(dqp->q_mount, xs_qm_dquot_unused);
 951         }
 952         xfs_dqunlock(dqp);
 953 }
 954
 955 /*
 956  * Release a dquot. Flush it if dirty, then dqput() it.
 957  * dquot must not be locked.
 958  */
 959 void
 960 xfs_qm_dqrele(
 961         xfs_dquot_t     *dqp)
 962 {
 963         if (!dqp)
 964                 return;
 965
 966         trace_xfs_dqrele(dqp);
 967
 968         xfs_dqlock(dqp);
 969         /*
 970          * We don't care to flush it if the dquot is dirty here.
 971          * That will create stutters that we want to avoid.
 972          * Instead we do a delayed write when we try to reclaim
 973          * a dirty dquot. Also xfs_sync will take part of the burden...
 974          */
 975         xfs_qm_dqput(dqp);
 976 }
 977
 978 /*
 979  * This is the dquot flushing I/O completion routine.  It is called
 980  * from interrupt level when the buffer containing the dquot is
 981  * flushed to disk.  It is responsible for removing the dquot logitem
 982  * from the AIL if it has not been re-logged, and unlocking the dquot's
 983  * flush lock. This behavior is very similar to that of inodes..
 984  */
 985 STATIC void
 986 xfs_qm_dqflush_done(
 987         struct xfs_buf          *bp,
 988         struct xfs_log_item     *lip)
 989 {
 990         xfs_dq_logitem_t        *qip = (struct xfs_dq_logitem *)lip;
 991         xfs_dquot_t             *dqp = qip->qli_dquot;
 992         struct xfs_ail          *ailp = lip->li_ailp;
 993
 994         /*
 995          * We only want to pull the item from the AIL if its
 996          * location in the log has not changed since we started the flush.
 997          * Thus, we only bother if the dquot's lsn has
 998          * not changed. First we check the lsn outside the lock
 999          * since it's cheaper, and then we recheck while
1000          * holding the lock before removing the dquot from the AIL.
1001          */
1002         if ((lip->li_flags & XFS_LI_IN_AIL) &&
1003             lip->li_lsn == qip->qli_flush_lsn) {
1004
1005                 /* xfs_trans_ail_delete() drops the AIL lock. */
1006                 spin_lock(&ailp->xa_lock);
1007                 if (lip->li_lsn == qip->qli_flush_lsn)
1008                         xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE);
1009                 else
1010                         spin_unlock(&ailp->xa_lock);
1011         }
1012
1013         /*
1014          * Release the dq's flush lock since we're done with it.
1015          */
1016         xfs_dqfunlock(dqp);
1017 }
1018
1019 /*
1020  * Write a modified dquot to disk.
1021  * The dquot must be locked and the flush lock too taken by caller.
1022  * The flush lock will not be unlocked until the dquot reaches the disk,
1023  * but the dquot is free to be unlocked and modified by the caller
1024  * in the interim. Dquot is still locked on return. This behavior is
1025  * identical to that of inodes.
1026  */
1027 int
1028 xfs_qm_dqflush(
1029         struct xfs_dquot        *dqp,
1030         struct xfs_buf          **bpp)
1031 {
1032         struct xfs_mount        *mp = dqp->q_mount;
1033         struct xfs_buf          *bp;
1034         struct xfs_disk_dquot   *ddqp;
1035         int                     error;
1036
1037         ASSERT(XFS_DQ_IS_LOCKED(dqp));
1038         ASSERT(!completion_done(&dqp->q_flush));
1039
1040         trace_xfs_dqflush(dqp);
1041
1042         *bpp = NULL;
1043
1044         xfs_qm_dqunpin_wait(dqp);
1045
1046         /*
1047          * This may have been unpinned because the filesystem is shutting
1048          * down forcibly. If that's the case we must not write this dquot
1049          * to disk, because the log record didn't make it to disk.
1050          *
1051          * We also have to remove the log item from the AIL in this case,
1052          * as we wait for an emptry AIL as part of the unmount process.
1053          */
1054         if (XFS_FORCED_SHUTDOWN(mp)) {
1055                 struct xfs_log_item     *lip = &dqp->q_logitem.qli_item;
1056                 dqp->dq_flags &= ~XFS_DQ_DIRTY;
1057
1058                 xfs_trans_ail_remove(lip, SHUTDOWN_CORRUPT_INCORE);
1059
1060                 error = -EIO;
1061                 goto out_unlock;
1062         }
1063
1064         /*
1065          * Get the buffer containing the on-disk dquot
1066          */
1067         error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
1068                                    mp->m_quotainfo->qi_dqchunklen, 0, &bp,
1069                                    &xfs_dquot_buf_ops);
1070         if (error)
1071                 goto out_unlock;
1072
1073         /*
1074          * Calculate the location of the dquot inside the buffer.
1075          */
1076         ddqp = bp->b_addr + dqp->q_bufoffset;
1077
1078         /*
1079          * A simple sanity check in case we got a corrupted dquot..
1080          */
1081         error = xfs_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
1082                            XFS_QMOPT_DOWARN, "dqflush (incore copy)");
1083         if (error) {
1084                 xfs_buf_relse(bp);
1085                 xfs_dqfunlock(dqp);
1086                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1087                 return -EIO;
1088         }
1089
1090         /* This is the only portion of data that needs to persist */
1091         memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
1092
1093         /*
1094          * Clear the dirty field and remember the flush lsn for later use.
1095          */
1096         dqp->dq_flags &= ~XFS_DQ_DIRTY;
1097
1098         xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1099                                         &dqp->q_logitem.qli_item.li_lsn);
1100
1101         /*
1102          * copy the lsn into the on-disk dquot now while we have the in memory
1103          * dquot here. This can't be done later in the write verifier as we
1104          * can't get access to the log item at that point in time.
1105          *
1106          * We also calculate the CRC here so that the on-disk dquot in the
1107          * buffer always has a valid CRC. This ensures there is no possibility
1108          * of a dquot without an up-to-date CRC getting to disk.
1109          */
1110         if (xfs_sb_version_hascrc(&mp->m_sb)) {
1111                 struct xfs_dqblk *dqb = (struct xfs_dqblk *)ddqp;
1112
1113                 dqb->dd_lsn = cpu_to_be64(dqp->q_logitem.qli_item.li_lsn);
1114                 xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
1115                                  XFS_DQUOT_CRC_OFF);
1116         }
1117
1118         /*
1119          * Attach an iodone routine so that we can remove this dquot from the
1120          * AIL and release the flush lock once the dquot is synced to disk.
1121          */
1122         xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1123                                   &dqp->q_logitem.qli_item);
1124
1125         /*
1126          * If the buffer is pinned then push on the log so we won't
1127          * get stuck waiting in the write for too long.
1128          */
1129         if (xfs_buf_ispinned(bp)) {
1130                 trace_xfs_dqflush_force(dqp);
1131                 xfs_log_force(mp, 0);
1132         }
1133
1134         trace_xfs_dqflush_done(dqp);
1135         *bpp = bp;
1136         return 0;
1137
1138 out_unlock:
1139         xfs_dqfunlock(dqp);
1140         return -EIO;
1141 }
1142
1143 /*
1144  * Lock two xfs_dquot structures.
1145  *
1146  * To avoid deadlocks we always lock the quota structure with
1147  * the lowerd id first.
1148  */
1149 void
1150 xfs_dqlock2(
1151         xfs_dquot_t     *d1,
1152         xfs_dquot_t     *d2)
1153 {
1154         if (d1 && d2) {
1155                 ASSERT(d1 != d2);
1156                 if (be32_to_cpu(d1->q_core.d_id) >
1157                     be32_to_cpu(d2->q_core.d_id)) {
1158                         mutex_lock(&d2->q_qlock);
1159                         mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1160                 } else {
1161                         mutex_lock(&d1->q_qlock);
1162                         mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1163                 }
1164         } else if (d1) {
1165                 mutex_lock(&d1->q_qlock);
1166         } else if (d2) {
1167                 mutex_lock(&d2->q_qlock);
1168         }
1169 }
1170
1171 int __init
1172 xfs_qm_init(void)
1173 {
1174         xfs_qm_dqzone =
1175                 kmem_zone_init(sizeof(struct xfs_dquot), "xfs_dquot");
1176         if (!xfs_qm_dqzone)
1177                 goto out;
1178
1179         xfs_qm_dqtrxzone =
1180                 kmem_zone_init(sizeof(struct xfs_dquot_acct), "xfs_dqtrx");
1181         if (!xfs_qm_dqtrxzone)
1182                 goto out_free_dqzone;
1183
1184         return 0;
1185
1186 out_free_dqzone:
1187         kmem_zone_destroy(xfs_qm_dqzone);
1188 out:
1189         return -ENOMEM;
1190 }
1191
1192 void
1193 xfs_qm_exit(void)
1194 {
1195         kmem_zone_destroy(xfs_qm_dqtrxzone);
1196         kmem_zone_destroy(xfs_qm_dqzone);
1197 }