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