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);
 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         struct xfs_mount        *mp,
 699         uint                    type,
 700         xfs_dqid_t              *id)
 701 {
 702         struct xfs_inode        *quotip = xfs_quota_inode(mp, type);
 703         xfs_dqid_t              next_id = *id + 1; /* simple advance */
 704         uint                    lock_flags;
 705         struct xfs_bmbt_irec    got;
 706         xfs_extnum_t            idx;
 707         xfs_fsblock_t           start;
 708         int                     error = 0;
 709
 710         /* If we'd wrap past the max ID, stop */
 711         if (next_id < *id)
 712                 return -ENOENT;
 713
 714         /* If new ID is within the current chunk, advancing it sufficed */
 715         if (next_id % mp->m_quotainfo->qi_dqperchunk) {
 716                 *id = next_id;
 717                 return 0;
 718         }
 719
 720         /* Nope, next_id is now past the current chunk, so find the next one */
 721         start = (xfs_fsblock_t)next_id / mp->m_quotainfo->qi_dqperchunk;
 722
 723         lock_flags = xfs_ilock_data_map_shared(quotip);
 724         if (!(quotip->i_df.if_flags & XFS_IFEXTENTS)) {
 725                 error = xfs_iread_extents(NULL, quotip, XFS_DATA_FORK);
 726                 if (error)
 727                         return error;
 728         }
 729
 730         if (xfs_iext_lookup_extent(quotip, &quotip->i_df, start, &idx, &got)) {
 731                 /* contiguous chunk, bump startoff for the id calculation */
 732                 if (got.br_startoff < start)
 733                         got.br_startoff = start;
 734                 *id = got.br_startoff * mp->m_quotainfo->qi_dqperchunk;
 735         } else {
 736                 error = -ENOENT;
 737         }
 738
 739         xfs_iunlock(quotip, lock_flags);
 740
 741         return error;
 742 }
 743
 744 /*
 745  * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
 746  * a locked dquot, doing an allocation (if requested) as needed.
 747  * When both an inode and an id are given, the inode's id takes precedence.
 748  * That is, if the id changes while we don't hold the ilock inside this
 749  * function, the new dquot is returned, not necessarily the one requested
 750  * in the id argument.
 751  */
 752 int
 753 xfs_qm_dqget(
 754         xfs_mount_t     *mp,
 755         xfs_inode_t     *ip,      /* locked inode (optional) */
 756         xfs_dqid_t      id,       /* uid/projid/gid depending on type */
 757         uint            type,     /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
 758         uint            flags,    /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
 759         xfs_dquot_t     **O_dqpp) /* OUT : locked incore dquot */
 760 {
 761         struct xfs_quotainfo    *qi = mp->m_quotainfo;
 762         struct radix_tree_root *tree = xfs_dquot_tree(qi, type);
 763         struct xfs_dquot        *dqp;
 764         int                     error;
 765
 766         ASSERT(XFS_IS_QUOTA_RUNNING(mp));
 767         if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
 768             (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
 769             (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
 770                 return -ESRCH;
 771         }
 772
 773 #ifdef DEBUG
 774         if (xfs_do_dqerror) {
 775                 if ((xfs_dqerror_target == mp->m_ddev_targp) &&
 776                     (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
 777                         xfs_debug(mp, "Returning error in dqget");
 778                         return -EIO;
 779                 }
 780         }
 781
 782         ASSERT(type == XFS_DQ_USER ||
 783                type == XFS_DQ_PROJ ||
 784                type == XFS_DQ_GROUP);
 785         if (ip) {
 786                 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 787                 ASSERT(xfs_inode_dquot(ip, type) == NULL);
 788         }
 789 #endif
 790
 791 restart:
 792         mutex_lock(&qi->qi_tree_lock);
 793         dqp = radix_tree_lookup(tree, id);
 794         if (dqp) {
 795                 xfs_dqlock(dqp);
 796                 if (dqp->dq_flags & XFS_DQ_FREEING) {
 797                         xfs_dqunlock(dqp);
 798                         mutex_unlock(&qi->qi_tree_lock);
 799                         trace_xfs_dqget_freeing(dqp);
 800                         delay(1);
 801                         goto restart;
 802                 }
 803
 804                 /* uninit / unused quota found in radix tree, keep looking  */
 805                 if (flags & XFS_QMOPT_DQNEXT) {
 806                         if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) {
 807                                 xfs_dqunlock(dqp);
 808                                 mutex_unlock(&qi->qi_tree_lock);
 809                                 error = xfs_dq_get_next_id(mp, type, &id);
 810                                 if (error)
 811                                         return error;
 812                                 goto restart;
 813                         }
 814                 }
 815
 816                 dqp->q_nrefs++;
 817                 mutex_unlock(&qi->qi_tree_lock);
 818
 819                 trace_xfs_dqget_hit(dqp);
 820                 XFS_STATS_INC(mp, xs_qm_dqcachehits);
 821                 *O_dqpp = dqp;
 822                 return 0;
 823         }
 824         mutex_unlock(&qi->qi_tree_lock);
 825         XFS_STATS_INC(mp, xs_qm_dqcachemisses);
 826
 827         /*
 828          * Dquot cache miss. We don't want to keep the inode lock across
 829          * a (potential) disk read. Also we don't want to deal with the lock
 830          * ordering between quotainode and this inode. OTOH, dropping the inode
 831          * lock here means dealing with a chown that can happen before
 832          * we re-acquire the lock.
 833          */
 834         if (ip)
 835                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 836
 837         error = xfs_qm_dqread(mp, id, type, flags, &dqp);
 838
 839         if (ip)
 840                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 841
 842         /* If we are asked to find next active id, keep looking */
 843         if (error == -ENOENT && (flags & XFS_QMOPT_DQNEXT)) {
 844                 error = xfs_dq_get_next_id(mp, type, &id);
 845                 if (!error)
 846                         goto restart;
 847         }
 848
 849         if (error)
 850                 return error;
 851
 852         if (ip) {
 853                 /*
 854                  * A dquot could be attached to this inode by now, since
 855                  * we had dropped the ilock.
 856                  */
 857                 if (xfs_this_quota_on(mp, type)) {
 858                         struct xfs_dquot        *dqp1;
 859
 860                         dqp1 = xfs_inode_dquot(ip, type);
 861                         if (dqp1) {
 862                                 xfs_qm_dqdestroy(dqp);
 863                                 dqp = dqp1;
 864                                 xfs_dqlock(dqp);
 865                                 goto dqret;
 866                         }
 867                 } else {
 868                         /* inode stays locked on return */
 869                         xfs_qm_dqdestroy(dqp);
 870                         return -ESRCH;
 871                 }
 872         }
 873
 874         mutex_lock(&qi->qi_tree_lock);
 875         error = radix_tree_insert(tree, id, dqp);
 876         if (unlikely(error)) {
 877                 WARN_ON(error != -EEXIST);
 878
 879                 /*
 880                  * Duplicate found. Just throw away the new dquot and start
 881                  * over.
 882                  */
 883                 mutex_unlock(&qi->qi_tree_lock);
 884                 trace_xfs_dqget_dup(dqp);
 885                 xfs_qm_dqdestroy(dqp);
 886                 XFS_STATS_INC(mp, xs_qm_dquot_dups);
 887                 goto restart;
 888         }
 889
 890         /*
 891          * We return a locked dquot to the caller, with a reference taken
 892          */
 893         xfs_dqlock(dqp);
 894         dqp->q_nrefs = 1;
 895
 896         qi->qi_dquots++;
 897         mutex_unlock(&qi->qi_tree_lock);
 898
 899         /* If we are asked to find next active id, keep looking */
 900         if (flags & XFS_QMOPT_DQNEXT) {
 901                 if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) {
 902                         xfs_qm_dqput(dqp);
 903                         error = xfs_dq_get_next_id(mp, type, &id);
 904                         if (error)
 905                                 return error;
 906                         goto restart;
 907                 }
 908         }
 909
 910  dqret:
 911         ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
 912         trace_xfs_dqget_miss(dqp);
 913         *O_dqpp = dqp;
 914         return 0;
 915 }
 916
 917 /*
 918  * Release a reference to the dquot (decrement ref-count) and unlock it.
 919  *
 920  * If there is a group quota attached to this dquot, carefully release that
 921  * too without tripping over deadlocks'n'stuff.
 922  */
 923 void
 924 xfs_qm_dqput(
 925         struct xfs_dquot        *dqp)
 926 {
 927         ASSERT(dqp->q_nrefs > 0);
 928         ASSERT(XFS_DQ_IS_LOCKED(dqp));
 929
 930         trace_xfs_dqput(dqp);
 931
 932         if (--dqp->q_nrefs == 0) {
 933                 struct xfs_quotainfo    *qi = dqp->q_mount->m_quotainfo;
 934                 trace_xfs_dqput_free(dqp);
 935
 936                 if (list_lru_add(&qi->qi_lru, &dqp->q_lru))
 937                         XFS_STATS_INC(dqp->q_mount, xs_qm_dquot_unused);
 938         }
 939         xfs_dqunlock(dqp);
 940 }
 941
 942 /*
 943  * Release a dquot. Flush it if dirty, then dqput() it.
 944  * dquot must not be locked.
 945  */
 946 void
 947 xfs_qm_dqrele(
 948         xfs_dquot_t     *dqp)
 949 {
 950         if (!dqp)
 951                 return;
 952
 953         trace_xfs_dqrele(dqp);
 954
 955         xfs_dqlock(dqp);
 956         /*
 957          * We don't care to flush it if the dquot is dirty here.
 958          * That will create stutters that we want to avoid.
 959          * Instead we do a delayed write when we try to reclaim
 960          * a dirty dquot. Also xfs_sync will take part of the burden...
 961          */
 962         xfs_qm_dqput(dqp);
 963 }
 964
 965 /*
 966  * This is the dquot flushing I/O completion routine.  It is called
 967  * from interrupt level when the buffer containing the dquot is
 968  * flushed to disk.  It is responsible for removing the dquot logitem
 969  * from the AIL if it has not been re-logged, and unlocking the dquot's
 970  * flush lock. This behavior is very similar to that of inodes..
 971  */
 972 STATIC void
 973 xfs_qm_dqflush_done(
 974         struct xfs_buf          *bp,
 975         struct xfs_log_item     *lip)
 976 {
 977         xfs_dq_logitem_t        *qip = (struct xfs_dq_logitem *)lip;
 978         xfs_dquot_t             *dqp = qip->qli_dquot;
 979         struct xfs_ail          *ailp = lip->li_ailp;
 980
 981         /*
 982          * We only want to pull the item from the AIL if its
 983          * location in the log has not changed since we started the flush.
 984          * Thus, we only bother if the dquot's lsn has
 985          * not changed. First we check the lsn outside the lock
 986          * since it's cheaper, and then we recheck while
 987          * holding the lock before removing the dquot from the AIL.
 988          */
 989         if ((lip->li_flags & XFS_LI_IN_AIL) &&
 990             ((lip->li_lsn == qip->qli_flush_lsn) ||
 991              (lip->li_flags & XFS_LI_FAILED))) {
 992
 993                 /* xfs_trans_ail_delete() drops the AIL lock. */
 994                 spin_lock(&ailp->xa_lock);
 995                 if (lip->li_lsn == qip->qli_flush_lsn) {
 996                         xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE);
 997                 } else {
 998                         /*
 999                          * Clear the failed state since we are about to drop the
1000                          * flush lock
1001                          */
1002                         if (lip->li_flags & XFS_LI_FAILED)
1003                                 xfs_clear_li_failed(lip);
1004                         spin_unlock(&ailp->xa_lock);
1005                 }
1006         }
1007
1008         /*
1009          * Release the dq's flush lock since we're done with it.
1010          */
1011         xfs_dqfunlock(dqp);
1012 }
1013
1014 /*
1015  * Write a modified dquot to disk.
1016  * The dquot must be locked and the flush lock too taken by caller.
1017  * The flush lock will not be unlocked until the dquot reaches the disk,
1018  * but the dquot is free to be unlocked and modified by the caller
1019  * in the interim. Dquot is still locked on return. This behavior is
1020  * identical to that of inodes.
1021  */
1022 int
1023 xfs_qm_dqflush(
1024         struct xfs_dquot        *dqp,
1025         struct xfs_buf          **bpp)
1026 {
1027         struct xfs_mount        *mp = dqp->q_mount;
1028         struct xfs_buf          *bp;
1029         struct xfs_disk_dquot   *ddqp;
1030         int                     error;
1031
1032         ASSERT(XFS_DQ_IS_LOCKED(dqp));
1033         ASSERT(!completion_done(&dqp->q_flush));
1034
1035         trace_xfs_dqflush(dqp);
1036
1037         *bpp = NULL;
1038
1039         xfs_qm_dqunpin_wait(dqp);
1040
1041         /*
1042          * This may have been unpinned because the filesystem is shutting
1043          * down forcibly. If that's the case we must not write this dquot
1044          * to disk, because the log record didn't make it to disk.
1045          *
1046          * We also have to remove the log item from the AIL in this case,
1047          * as we wait for an emptry AIL as part of the unmount process.
1048          */
1049         if (XFS_FORCED_SHUTDOWN(mp)) {
1050                 struct xfs_log_item     *lip = &dqp->q_logitem.qli_item;
1051                 dqp->dq_flags &= ~XFS_DQ_DIRTY;
1052
1053                 xfs_trans_ail_remove(lip, SHUTDOWN_CORRUPT_INCORE);
1054
1055                 error = -EIO;
1056                 goto out_unlock;
1057         }
1058
1059         /*
1060          * Get the buffer containing the on-disk dquot
1061          */
1062         error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
1063                                    mp->m_quotainfo->qi_dqchunklen, 0, &bp,
1064                                    &xfs_dquot_buf_ops);
1065         if (error)
1066                 goto out_unlock;
1067
1068         /*
1069          * Calculate the location of the dquot inside the buffer.
1070          */
1071         ddqp = bp->b_addr + dqp->q_bufoffset;
1072
1073         /*
1074          * A simple sanity check in case we got a corrupted dquot..
1075          */
1076         error = xfs_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
1077                            XFS_QMOPT_DOWARN, "dqflush (incore copy)");
1078         if (error) {
1079                 xfs_buf_relse(bp);
1080                 xfs_dqfunlock(dqp);
1081                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1082                 return -EIO;
1083         }
1084
1085         /* This is the only portion of data that needs to persist */
1086         memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
1087
1088         /*
1089          * Clear the dirty field and remember the flush lsn for later use.
1090          */
1091         dqp->dq_flags &= ~XFS_DQ_DIRTY;
1092
1093         xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1094                                         &dqp->q_logitem.qli_item.li_lsn);
1095
1096         /*
1097          * copy the lsn into the on-disk dquot now while we have the in memory
1098          * dquot here. This can't be done later in the write verifier as we
1099          * can't get access to the log item at that point in time.
1100          *
1101          * We also calculate the CRC here so that the on-disk dquot in the
1102          * buffer always has a valid CRC. This ensures there is no possibility
1103          * of a dquot without an up-to-date CRC getting to disk.
1104          */
1105         if (xfs_sb_version_hascrc(&mp->m_sb)) {
1106                 struct xfs_dqblk *dqb = (struct xfs_dqblk *)ddqp;
1107
1108                 dqb->dd_lsn = cpu_to_be64(dqp->q_logitem.qli_item.li_lsn);
1109                 xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
1110                                  XFS_DQUOT_CRC_OFF);
1111         }
1112
1113         /*
1114          * Attach an iodone routine so that we can remove this dquot from the
1115          * AIL and release the flush lock once the dquot is synced to disk.
1116          */
1117         xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1118                                   &dqp->q_logitem.qli_item);
1119
1120         /*
1121          * If the buffer is pinned then push on the log so we won't
1122          * get stuck waiting in the write for too long.
1123          */
1124         if (xfs_buf_ispinned(bp)) {
1125                 trace_xfs_dqflush_force(dqp);
1126                 xfs_log_force(mp, 0);
1127         }
1128
1129         trace_xfs_dqflush_done(dqp);
1130         *bpp = bp;
1131         return 0;
1132
1133 out_unlock:
1134         xfs_dqfunlock(dqp);
1135         return -EIO;
1136 }
1137
1138 /*
1139  * Lock two xfs_dquot structures.
1140  *
1141  * To avoid deadlocks we always lock the quota structure with
1142  * the lowerd id first.
1143  */
1144 void
1145 xfs_dqlock2(
1146         xfs_dquot_t     *d1,
1147         xfs_dquot_t     *d2)
1148 {
1149         if (d1 && d2) {
1150                 ASSERT(d1 != d2);
1151                 if (be32_to_cpu(d1->q_core.d_id) >
1152                     be32_to_cpu(d2->q_core.d_id)) {
1153                         mutex_lock(&d2->q_qlock);
1154                         mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1155                 } else {
1156                         mutex_lock(&d1->q_qlock);
1157                         mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1158                 }
1159         } else if (d1) {
1160                 mutex_lock(&d1->q_qlock);
1161         } else if (d2) {
1162                 mutex_lock(&d2->q_qlock);
1163         }
1164 }
1165
1166 int __init
1167 xfs_qm_init(void)
1168 {
1169         xfs_qm_dqzone =
1170                 kmem_zone_init(sizeof(struct xfs_dquot), "xfs_dquot");
1171         if (!xfs_qm_dqzone)
1172                 goto out;
1173
1174         xfs_qm_dqtrxzone =
1175                 kmem_zone_init(sizeof(struct xfs_dquot_acct), "xfs_dqtrx");
1176         if (!xfs_qm_dqtrxzone)
1177                 goto out_free_dqzone;
1178
1179         return 0;
1180
1181 out_free_dqzone:
1182         kmem_zone_destroy(xfs_qm_dqzone);
1183 out:
1184         return -ENOMEM;
1185 }
1186
1187 void
1188 xfs_qm_exit(void)
1189 {
1190         kmem_zone_destroy(xfs_qm_dqtrxzone);
1191         kmem_zone_destroy(xfs_qm_dqzone);
1192 }