linux/fs/xfs/xfs_dquot.c
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   1/*
   2 * Copyright (c) 2000-2003 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#include "xfs.h"
  19#include "xfs_fs.h"
  20#include "xfs_bit.h"
  21#include "xfs_log.h"
  22#include "xfs_trans.h"
  23#include "xfs_sb.h"
  24#include "xfs_ag.h"
  25#include "xfs_alloc.h"
  26#include "xfs_quota.h"
  27#include "xfs_mount.h"
  28#include "xfs_bmap_btree.h"
  29#include "xfs_inode.h"
  30#include "xfs_bmap.h"
  31#include "xfs_rtalloc.h"
  32#include "xfs_error.h"
  33#include "xfs_itable.h"
  34#include "xfs_attr.h"
  35#include "xfs_buf_item.h"
  36#include "xfs_trans_space.h"
  37#include "xfs_trans_priv.h"
  38#include "xfs_qm.h"
  39#include "xfs_trace.h"
  40
  41/*
  42 * Lock order:
  43 *
  44 * ip->i_lock
  45 *   qi->qi_tree_lock
  46 *     dquot->q_qlock (xfs_dqlock() and friends)
  47 *       dquot->q_flush (xfs_dqflock() and friends)
  48 *       qi->qi_lru_lock
  49 *
  50 * If two dquots need to be locked the order is user before group/project,
  51 * otherwise by the lowest id first, see xfs_dqlock2.
  52 */
  53
  54#ifdef DEBUG
  55xfs_buftarg_t *xfs_dqerror_target;
  56int xfs_do_dqerror;
  57int xfs_dqreq_num;
  58int xfs_dqerror_mod = 33;
  59#endif
  60
  61struct kmem_zone                *xfs_qm_dqtrxzone;
  62static struct kmem_zone         *xfs_qm_dqzone;
  63
  64static struct lock_class_key xfs_dquot_other_class;
  65
  66/*
  67 * This is called to free all the memory associated with a dquot
  68 */
  69void
  70xfs_qm_dqdestroy(
  71        xfs_dquot_t     *dqp)
  72{
  73        ASSERT(list_empty(&dqp->q_lru));
  74
  75        mutex_destroy(&dqp->q_qlock);
  76        kmem_zone_free(xfs_qm_dqzone, dqp);
  77
  78        XFS_STATS_DEC(xs_qm_dquot);
  79}
  80
  81/*
  82 * If default limits are in force, push them into the dquot now.
  83 * We overwrite the dquot limits only if they are zero and this
  84 * is not the root dquot.
  85 */
  86void
  87xfs_qm_adjust_dqlimits(
  88        xfs_mount_t             *mp,
  89        xfs_disk_dquot_t        *d)
  90{
  91        xfs_quotainfo_t         *q = mp->m_quotainfo;
  92
  93        ASSERT(d->d_id);
  94
  95        if (q->qi_bsoftlimit && !d->d_blk_softlimit)
  96                d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
  97        if (q->qi_bhardlimit && !d->d_blk_hardlimit)
  98                d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
  99        if (q->qi_isoftlimit && !d->d_ino_softlimit)
 100                d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
 101        if (q->qi_ihardlimit && !d->d_ino_hardlimit)
 102                d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
 103        if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
 104                d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
 105        if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
 106                d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
 107}
 108
 109/*
 110 * Check the limits and timers of a dquot and start or reset timers
 111 * if necessary.
 112 * This gets called even when quota enforcement is OFF, which makes our
 113 * life a little less complicated. (We just don't reject any quota
 114 * reservations in that case, when enforcement is off).
 115 * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
 116 * enforcement's off.
 117 * In contrast, warnings are a little different in that they don't
 118 * 'automatically' get started when limits get exceeded.  They do
 119 * get reset to zero, however, when we find the count to be under
 120 * the soft limit (they are only ever set non-zero via userspace).
 121 */
 122void
 123xfs_qm_adjust_dqtimers(
 124        xfs_mount_t             *mp,
 125        xfs_disk_dquot_t        *d)
 126{
 127        ASSERT(d->d_id);
 128
 129#ifdef DEBUG
 130        if (d->d_blk_hardlimit)
 131                ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
 132                       be64_to_cpu(d->d_blk_hardlimit));
 133        if (d->d_ino_hardlimit)
 134                ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
 135                       be64_to_cpu(d->d_ino_hardlimit));
 136        if (d->d_rtb_hardlimit)
 137                ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
 138                       be64_to_cpu(d->d_rtb_hardlimit));
 139#endif
 140
 141        if (!d->d_btimer) {
 142                if ((d->d_blk_softlimit &&
 143                     (be64_to_cpu(d->d_bcount) >
 144                      be64_to_cpu(d->d_blk_softlimit))) ||
 145                    (d->d_blk_hardlimit &&
 146                     (be64_to_cpu(d->d_bcount) >
 147                      be64_to_cpu(d->d_blk_hardlimit)))) {
 148                        d->d_btimer = cpu_to_be32(get_seconds() +
 149                                        mp->m_quotainfo->qi_btimelimit);
 150                } else {
 151                        d->d_bwarns = 0;
 152                }
 153        } else {
 154                if ((!d->d_blk_softlimit ||
 155                     (be64_to_cpu(d->d_bcount) <=
 156                      be64_to_cpu(d->d_blk_softlimit))) &&
 157                    (!d->d_blk_hardlimit ||
 158                    (be64_to_cpu(d->d_bcount) <=
 159                     be64_to_cpu(d->d_blk_hardlimit)))) {
 160                        d->d_btimer = 0;
 161                }
 162        }
 163
 164        if (!d->d_itimer) {
 165                if ((d->d_ino_softlimit &&
 166                     (be64_to_cpu(d->d_icount) >
 167                      be64_to_cpu(d->d_ino_softlimit))) ||
 168                    (d->d_ino_hardlimit &&
 169                     (be64_to_cpu(d->d_icount) >
 170                      be64_to_cpu(d->d_ino_hardlimit)))) {
 171                        d->d_itimer = cpu_to_be32(get_seconds() +
 172                                        mp->m_quotainfo->qi_itimelimit);
 173                } else {
 174                        d->d_iwarns = 0;
 175                }
 176        } else {
 177                if ((!d->d_ino_softlimit ||
 178                     (be64_to_cpu(d->d_icount) <=
 179                      be64_to_cpu(d->d_ino_softlimit)))  &&
 180                    (!d->d_ino_hardlimit ||
 181                     (be64_to_cpu(d->d_icount) <=
 182                      be64_to_cpu(d->d_ino_hardlimit)))) {
 183                        d->d_itimer = 0;
 184                }
 185        }
 186
 187        if (!d->d_rtbtimer) {
 188                if ((d->d_rtb_softlimit &&
 189                     (be64_to_cpu(d->d_rtbcount) >
 190                      be64_to_cpu(d->d_rtb_softlimit))) ||
 191                    (d->d_rtb_hardlimit &&
 192                     (be64_to_cpu(d->d_rtbcount) >
 193                      be64_to_cpu(d->d_rtb_hardlimit)))) {
 194                        d->d_rtbtimer = cpu_to_be32(get_seconds() +
 195                                        mp->m_quotainfo->qi_rtbtimelimit);
 196                } else {
 197                        d->d_rtbwarns = 0;
 198                }
 199        } else {
 200                if ((!d->d_rtb_softlimit ||
 201                     (be64_to_cpu(d->d_rtbcount) <=
 202                      be64_to_cpu(d->d_rtb_softlimit))) &&
 203                    (!d->d_rtb_hardlimit ||
 204                     (be64_to_cpu(d->d_rtbcount) <=
 205                      be64_to_cpu(d->d_rtb_hardlimit)))) {
 206                        d->d_rtbtimer = 0;
 207                }
 208        }
 209}
 210
 211/*
 212 * initialize a buffer full of dquots and log the whole thing
 213 */
 214STATIC void
 215xfs_qm_init_dquot_blk(
 216        xfs_trans_t     *tp,
 217        xfs_mount_t     *mp,
 218        xfs_dqid_t      id,
 219        uint            type,
 220        xfs_buf_t       *bp)
 221{
 222        struct xfs_quotainfo    *q = mp->m_quotainfo;
 223        xfs_dqblk_t     *d;
 224        int             curid, i;
 225
 226        ASSERT(tp);
 227        ASSERT(xfs_buf_islocked(bp));
 228
 229        d = bp->b_addr;
 230
 231        /*
 232         * ID of the first dquot in the block - id's are zero based.
 233         */
 234        curid = id - (id % q->qi_dqperchunk);
 235        ASSERT(curid >= 0);
 236        memset(d, 0, BBTOB(q->qi_dqchunklen));
 237        for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++) {
 238                d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 239                d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 240                d->dd_diskdq.d_id = cpu_to_be32(curid);
 241                d->dd_diskdq.d_flags = type;
 242        }
 243
 244        xfs_trans_dquot_buf(tp, bp,
 245                            (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
 246                            ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
 247                             XFS_BLF_GDQUOT_BUF)));
 248        xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
 249}
 250
 251static void
 252xfs_dquot_buf_verify(
 253        struct xfs_buf          *bp)
 254{
 255        struct xfs_mount        *mp = bp->b_target->bt_mount;
 256        struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 257        struct xfs_disk_dquot   *ddq;
 258        xfs_dqid_t              id = 0;
 259        int                     i;
 260
 261        /*
 262         * On the first read of the buffer, verify that each dquot is valid.
 263         * We don't know what the id of the dquot is supposed to be, just that
 264         * they should be increasing monotonically within the buffer. If the
 265         * first id is corrupt, then it will fail on the second dquot in the
 266         * buffer so corruptions could point to the wrong dquot in this case.
 267         */
 268        for (i = 0; i < mp->m_quotainfo->qi_dqperchunk; i++) {
 269                int     error;
 270
 271                ddq = &d[i].dd_diskdq;
 272
 273                if (i == 0)
 274                        id = be32_to_cpu(ddq->d_id);
 275
 276                error = xfs_qm_dqcheck(mp, ddq, id + i, 0, XFS_QMOPT_DOWARN,
 277                                        "xfs_dquot_read_verify");
 278                if (error) {
 279                        XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, d);
 280                        xfs_buf_ioerror(bp, EFSCORRUPTED);
 281                        break;
 282                }
 283        }
 284}
 285
 286static void
 287xfs_dquot_buf_read_verify(
 288        struct xfs_buf  *bp)
 289{
 290        xfs_dquot_buf_verify(bp);
 291}
 292
 293void
 294xfs_dquot_buf_write_verify(
 295        struct xfs_buf  *bp)
 296{
 297        xfs_dquot_buf_verify(bp);
 298}
 299
 300const struct xfs_buf_ops xfs_dquot_buf_ops = {
 301        .verify_read = xfs_dquot_buf_read_verify,
 302        .verify_write = xfs_dquot_buf_write_verify,
 303};
 304
 305/*
 306 * Allocate a block and fill it with dquots.
 307 * This is called when the bmapi finds a hole.
 308 */
 309STATIC int
 310xfs_qm_dqalloc(
 311        xfs_trans_t     **tpp,
 312        xfs_mount_t     *mp,
 313        xfs_dquot_t     *dqp,
 314        xfs_inode_t     *quotip,
 315        xfs_fileoff_t   offset_fsb,
 316        xfs_buf_t       **O_bpp)
 317{
 318        xfs_fsblock_t   firstblock;
 319        xfs_bmap_free_t flist;
 320        xfs_bmbt_irec_t map;
 321        int             nmaps, error, committed;
 322        xfs_buf_t       *bp;
 323        xfs_trans_t     *tp = *tpp;
 324
 325        ASSERT(tp != NULL);
 326
 327        trace_xfs_dqalloc(dqp);
 328
 329        /*
 330         * Initialize the bmap freelist prior to calling bmapi code.
 331         */
 332        xfs_bmap_init(&flist, &firstblock);
 333        xfs_ilock(quotip, XFS_ILOCK_EXCL);
 334        /*
 335         * Return if this type of quotas is turned off while we didn't
 336         * have an inode lock
 337         */
 338        if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
 339                xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 340                return (ESRCH);
 341        }
 342
 343        xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
 344        nmaps = 1;
 345        error = xfs_bmapi_write(tp, quotip, offset_fsb,
 346                                XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
 347                                &firstblock, XFS_QM_DQALLOC_SPACE_RES(mp),
 348                                &map, &nmaps, &flist);
 349        if (error)
 350                goto error0;
 351        ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
 352        ASSERT(nmaps == 1);
 353        ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 354               (map.br_startblock != HOLESTARTBLOCK));
 355
 356        /*
 357         * Keep track of the blkno to save a lookup later
 358         */
 359        dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 360
 361        /* now we can just get the buffer (there's nothing to read yet) */
 362        bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
 363                               dqp->q_blkno,
 364                               mp->m_quotainfo->qi_dqchunklen,
 365                               0);
 366
 367        error = xfs_buf_geterror(bp);
 368        if (error)
 369                goto error1;
 370        bp->b_ops = &xfs_dquot_buf_ops;
 371
 372        /*
 373         * Make a chunk of dquots out of this buffer and log
 374         * the entire thing.
 375         */
 376        xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
 377                              dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
 378
 379        /*
 380         * xfs_bmap_finish() may commit the current transaction and
 381         * start a second transaction if the freelist is not empty.
 382         *
 383         * Since we still want to modify this buffer, we need to
 384         * ensure that the buffer is not released on commit of
 385         * the first transaction and ensure the buffer is added to the
 386         * second transaction.
 387         *
 388         * If there is only one transaction then don't stop the buffer
 389         * from being released when it commits later on.
 390         */
 391
 392        xfs_trans_bhold(tp, bp);
 393
 394        if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
 395                goto error1;
 396        }
 397
 398        if (committed) {
 399                tp = *tpp;
 400                xfs_trans_bjoin(tp, bp);
 401        } else {
 402                xfs_trans_bhold_release(tp, bp);
 403        }
 404
 405        *O_bpp = bp;
 406        return 0;
 407
 408      error1:
 409        xfs_bmap_cancel(&flist);
 410      error0:
 411        xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 412
 413        return (error);
 414}
 415STATIC int
 416xfs_qm_dqrepair(
 417        struct xfs_mount        *mp,
 418        struct xfs_trans        *tp,
 419        struct xfs_dquot        *dqp,
 420        xfs_dqid_t              firstid,
 421        struct xfs_buf          **bpp)
 422{
 423        int                     error;
 424        struct xfs_disk_dquot   *ddq;
 425        struct xfs_dqblk        *d;
 426        int                     i;
 427
 428        /*
 429         * Read the buffer without verification so we get the corrupted
 430         * buffer returned to us. make sure we verify it on write, though.
 431         */
 432        error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, dqp->q_blkno,
 433                                   mp->m_quotainfo->qi_dqchunklen,
 434                                   0, bpp, NULL);
 435
 436        if (error) {
 437                ASSERT(*bpp == NULL);
 438                return XFS_ERROR(error);
 439        }
 440        (*bpp)->b_ops = &xfs_dquot_buf_ops;
 441
 442        ASSERT(xfs_buf_islocked(*bpp));
 443        d = (struct xfs_dqblk *)(*bpp)->b_addr;
 444
 445        /* Do the actual repair of dquots in this buffer */
 446        for (i = 0; i < mp->m_quotainfo->qi_dqperchunk; i++) {
 447                ddq = &d[i].dd_diskdq;
 448                error = xfs_qm_dqcheck(mp, ddq, firstid + i,
 449                                       dqp->dq_flags & XFS_DQ_ALLTYPES,
 450                                       XFS_QMOPT_DQREPAIR, "xfs_qm_dqrepair");
 451                if (error) {
 452                        /* repair failed, we're screwed */
 453                        xfs_trans_brelse(tp, *bpp);
 454                        return XFS_ERROR(EIO);
 455                }
 456        }
 457
 458        return 0;
 459}
 460
 461/*
 462 * Maps a dquot to the buffer containing its on-disk version.
 463 * This returns a ptr to the buffer containing the on-disk dquot
 464 * in the bpp param, and a ptr to the on-disk dquot within that buffer
 465 */
 466STATIC int
 467xfs_qm_dqtobp(
 468        xfs_trans_t             **tpp,
 469        xfs_dquot_t             *dqp,
 470        xfs_disk_dquot_t        **O_ddpp,
 471        xfs_buf_t               **O_bpp,
 472        uint                    flags)
 473{
 474        xfs_bmbt_irec_t map;
 475        int             nmaps = 1, error;
 476        xfs_buf_t       *bp;
 477        xfs_inode_t     *quotip = XFS_DQ_TO_QIP(dqp);
 478        xfs_mount_t     *mp = dqp->q_mount;
 479        xfs_dqid_t      id = be32_to_cpu(dqp->q_core.d_id);
 480        xfs_trans_t     *tp = (tpp ? *tpp : NULL);
 481
 482        dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
 483
 484        xfs_ilock(quotip, XFS_ILOCK_SHARED);
 485        if (!xfs_this_quota_on(dqp->q_mount, dqp->dq_flags)) {
 486                /*
 487                 * Return if this type of quotas is turned off while we
 488                 * didn't have the quota inode lock.
 489                 */
 490                xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 491                return ESRCH;
 492        }
 493
 494        /*
 495         * Find the block map; no allocations yet
 496         */
 497        error = xfs_bmapi_read(quotip, dqp->q_fileoffset,
 498                               XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
 499
 500        xfs_iunlock(quotip, XFS_ILOCK_SHARED);
 501        if (error)
 502                return error;
 503
 504        ASSERT(nmaps == 1);
 505        ASSERT(map.br_blockcount == 1);
 506
 507        /*
 508         * Offset of dquot in the (fixed sized) dquot chunk.
 509         */
 510        dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
 511                sizeof(xfs_dqblk_t);
 512
 513        ASSERT(map.br_startblock != DELAYSTARTBLOCK);
 514        if (map.br_startblock == HOLESTARTBLOCK) {
 515                /*
 516                 * We don't allocate unless we're asked to
 517                 */
 518                if (!(flags & XFS_QMOPT_DQALLOC))
 519                        return ENOENT;
 520
 521                ASSERT(tp);
 522                error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
 523                                        dqp->q_fileoffset, &bp);
 524                if (error)
 525                        return error;
 526                tp = *tpp;
 527        } else {
 528                trace_xfs_dqtobp_read(dqp);
 529
 530                /*
 531                 * store the blkno etc so that we don't have to do the
 532                 * mapping all the time
 533                 */
 534                dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 535
 536                error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 537                                           dqp->q_blkno,
 538                                           mp->m_quotainfo->qi_dqchunklen,
 539                                           0, &bp, &xfs_dquot_buf_ops);
 540
 541                if (error == EFSCORRUPTED && (flags & XFS_QMOPT_DQREPAIR)) {
 542                        xfs_dqid_t firstid = (xfs_dqid_t)map.br_startoff *
 543                                                mp->m_quotainfo->qi_dqperchunk;
 544                        ASSERT(bp == NULL);
 545                        error = xfs_qm_dqrepair(mp, tp, dqp, firstid, &bp);
 546                }
 547
 548                if (error) {
 549                        ASSERT(bp == NULL);
 550                        return XFS_ERROR(error);
 551                }
 552        }
 553
 554        ASSERT(xfs_buf_islocked(bp));
 555        *O_bpp = bp;
 556        *O_ddpp = bp->b_addr + dqp->q_bufoffset;
 557
 558        return (0);
 559}
 560
 561
 562/*
 563 * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
 564 * and release the buffer immediately.
 565 *
 566 * If XFS_QMOPT_DQALLOC is set, allocate a dquot on disk if it needed.
 567 */
 568int
 569xfs_qm_dqread(
 570        struct xfs_mount        *mp,
 571        xfs_dqid_t              id,
 572        uint                    type,
 573        uint                    flags,
 574        struct xfs_dquot        **O_dqpp)
 575{
 576        struct xfs_dquot        *dqp;
 577        struct xfs_disk_dquot   *ddqp;
 578        struct xfs_buf          *bp;
 579        struct xfs_trans        *tp = NULL;
 580        int                     error;
 581        int                     cancelflags = 0;
 582
 583
 584        dqp = kmem_zone_zalloc(xfs_qm_dqzone, KM_SLEEP);
 585
 586        dqp->dq_flags = type;
 587        dqp->q_core.d_id = cpu_to_be32(id);
 588        dqp->q_mount = mp;
 589        INIT_LIST_HEAD(&dqp->q_lru);
 590        mutex_init(&dqp->q_qlock);
 591        init_waitqueue_head(&dqp->q_pinwait);
 592
 593        /*
 594         * Because we want to use a counting completion, complete
 595         * the flush completion once to allow a single access to
 596         * the flush completion without blocking.
 597         */
 598        init_completion(&dqp->q_flush);
 599        complete(&dqp->q_flush);
 600
 601        /*
 602         * Make sure group quotas have a different lock class than user
 603         * quotas.
 604         */
 605        if (!(type & XFS_DQ_USER))
 606                lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
 607
 608        XFS_STATS_INC(xs_qm_dquot);
 609
 610        trace_xfs_dqread(dqp);
 611
 612        if (flags & XFS_QMOPT_DQALLOC) {
 613                tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
 614                error = xfs_trans_reserve(tp, XFS_QM_DQALLOC_SPACE_RES(mp),
 615                                XFS_WRITE_LOG_RES(mp) +
 616                                /*
 617                                 * Round the chunklen up to the next multiple
 618                                 * of 128 (buf log item chunk size)).
 619                                 */
 620                                BBTOB(mp->m_quotainfo->qi_dqchunklen) - 1 + 128,
 621                                0,
 622                                XFS_TRANS_PERM_LOG_RES,
 623                                XFS_WRITE_LOG_COUNT);
 624                if (error)
 625                        goto error1;
 626                cancelflags = XFS_TRANS_RELEASE_LOG_RES;
 627        }
 628
 629        /*
 630         * get a pointer to the on-disk dquot and the buffer containing it
 631         * dqp already knows its own type (GROUP/USER).
 632         */
 633        error = xfs_qm_dqtobp(&tp, dqp, &ddqp, &bp, flags);
 634        if (error) {
 635                /*
 636                 * This can happen if quotas got turned off (ESRCH),
 637                 * or if the dquot didn't exist on disk and we ask to
 638                 * allocate (ENOENT).
 639                 */
 640                trace_xfs_dqread_fail(dqp);
 641                cancelflags |= XFS_TRANS_ABORT;
 642                goto error1;
 643        }
 644
 645        /* copy everything from disk dquot to the incore dquot */
 646        memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
 647        xfs_qm_dquot_logitem_init(dqp);
 648
 649        /*
 650         * Reservation counters are defined as reservation plus current usage
 651         * to avoid having to add every time.
 652         */
 653        dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
 654        dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
 655        dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
 656
 657        /* Mark the buf so that this will stay incore a little longer */
 658        xfs_buf_set_ref(bp, XFS_DQUOT_REF);
 659
 660        /*
 661         * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
 662         * So we need to release with xfs_trans_brelse().
 663         * The strategy here is identical to that of inodes; we lock
 664         * the dquot in xfs_qm_dqget() before making it accessible to
 665         * others. This is because dquots, like inodes, need a good level of
 666         * concurrency, and we don't want to take locks on the entire buffers
 667         * for dquot accesses.
 668         * Note also that the dquot buffer may even be dirty at this point, if
 669         * this particular dquot was repaired. We still aren't afraid to
 670         * brelse it because we have the changes incore.
 671         */
 672        ASSERT(xfs_buf_islocked(bp));
 673        xfs_trans_brelse(tp, bp);
 674
 675        if (tp) {
 676                error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 677                if (error)
 678                        goto error0;
 679        }
 680
 681        *O_dqpp = dqp;
 682        return error;
 683
 684error1:
 685        if (tp)
 686                xfs_trans_cancel(tp, cancelflags);
 687error0:
 688        xfs_qm_dqdestroy(dqp);
 689        *O_dqpp = NULL;
 690        return error;
 691}
 692
 693/*
 694 * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
 695 * a locked dquot, doing an allocation (if requested) as needed.
 696 * When both an inode and an id are given, the inode's id takes precedence.
 697 * That is, if the id changes while we don't hold the ilock inside this
 698 * function, the new dquot is returned, not necessarily the one requested
 699 * in the id argument.
 700 */
 701int
 702xfs_qm_dqget(
 703        xfs_mount_t     *mp,
 704        xfs_inode_t     *ip,      /* locked inode (optional) */
 705        xfs_dqid_t      id,       /* uid/projid/gid depending on type */
 706        uint            type,     /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
 707        uint            flags,    /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
 708        xfs_dquot_t     **O_dqpp) /* OUT : locked incore dquot */
 709{
 710        struct xfs_quotainfo    *qi = mp->m_quotainfo;
 711        struct radix_tree_root *tree = XFS_DQUOT_TREE(qi, type);
 712        struct xfs_dquot        *dqp;
 713        int                     error;
 714
 715        ASSERT(XFS_IS_QUOTA_RUNNING(mp));
 716        if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
 717            (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
 718            (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
 719                return (ESRCH);
 720        }
 721
 722#ifdef DEBUG
 723        if (xfs_do_dqerror) {
 724                if ((xfs_dqerror_target == mp->m_ddev_targp) &&
 725                    (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
 726                        xfs_debug(mp, "Returning error in dqget");
 727                        return (EIO);
 728                }
 729        }
 730
 731        ASSERT(type == XFS_DQ_USER ||
 732               type == XFS_DQ_PROJ ||
 733               type == XFS_DQ_GROUP);
 734        if (ip) {
 735                ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 736                ASSERT(xfs_inode_dquot(ip, type) == NULL);
 737        }
 738#endif
 739
 740restart:
 741        mutex_lock(&qi->qi_tree_lock);
 742        dqp = radix_tree_lookup(tree, id);
 743        if (dqp) {
 744                xfs_dqlock(dqp);
 745                if (dqp->dq_flags & XFS_DQ_FREEING) {
 746                        xfs_dqunlock(dqp);
 747                        mutex_unlock(&qi->qi_tree_lock);
 748                        trace_xfs_dqget_freeing(dqp);
 749                        delay(1);
 750                        goto restart;
 751                }
 752
 753                dqp->q_nrefs++;
 754                mutex_unlock(&qi->qi_tree_lock);
 755
 756                trace_xfs_dqget_hit(dqp);
 757                XFS_STATS_INC(xs_qm_dqcachehits);
 758                *O_dqpp = dqp;
 759                return 0;
 760        }
 761        mutex_unlock(&qi->qi_tree_lock);
 762        XFS_STATS_INC(xs_qm_dqcachemisses);
 763
 764        /*
 765         * Dquot cache miss. We don't want to keep the inode lock across
 766         * a (potential) disk read. Also we don't want to deal with the lock
 767         * ordering between quotainode and this inode. OTOH, dropping the inode
 768         * lock here means dealing with a chown that can happen before
 769         * we re-acquire the lock.
 770         */
 771        if (ip)
 772                xfs_iunlock(ip, XFS_ILOCK_EXCL);
 773
 774        error = xfs_qm_dqread(mp, id, type, flags, &dqp);
 775
 776        if (ip)
 777                xfs_ilock(ip, XFS_ILOCK_EXCL);
 778
 779        if (error)
 780                return error;
 781
 782        if (ip) {
 783                /*
 784                 * A dquot could be attached to this inode by now, since
 785                 * we had dropped the ilock.
 786                 */
 787                if (xfs_this_quota_on(mp, type)) {
 788                        struct xfs_dquot        *dqp1;
 789
 790                        dqp1 = xfs_inode_dquot(ip, type);
 791                        if (dqp1) {
 792                                xfs_qm_dqdestroy(dqp);
 793                                dqp = dqp1;
 794                                xfs_dqlock(dqp);
 795                                goto dqret;
 796                        }
 797                } else {
 798                        /* inode stays locked on return */
 799                        xfs_qm_dqdestroy(dqp);
 800                        return XFS_ERROR(ESRCH);
 801                }
 802        }
 803
 804        mutex_lock(&qi->qi_tree_lock);
 805        error = -radix_tree_insert(tree, id, dqp);
 806        if (unlikely(error)) {
 807                WARN_ON(error != EEXIST);
 808
 809                /*
 810                 * Duplicate found. Just throw away the new dquot and start
 811                 * over.
 812                 */
 813                mutex_unlock(&qi->qi_tree_lock);
 814                trace_xfs_dqget_dup(dqp);
 815                xfs_qm_dqdestroy(dqp);
 816                XFS_STATS_INC(xs_qm_dquot_dups);
 817                goto restart;
 818        }
 819
 820        /*
 821         * We return a locked dquot to the caller, with a reference taken
 822         */
 823        xfs_dqlock(dqp);
 824        dqp->q_nrefs = 1;
 825
 826        qi->qi_dquots++;
 827        mutex_unlock(&qi->qi_tree_lock);
 828
 829 dqret:
 830        ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
 831        trace_xfs_dqget_miss(dqp);
 832        *O_dqpp = dqp;
 833        return (0);
 834}
 835
 836
 837STATIC void
 838xfs_qm_dqput_final(
 839        struct xfs_dquot        *dqp)
 840{
 841        struct xfs_quotainfo    *qi = dqp->q_mount->m_quotainfo;
 842        struct xfs_dquot        *gdqp;
 843
 844        trace_xfs_dqput_free(dqp);
 845
 846        mutex_lock(&qi->qi_lru_lock);
 847        if (list_empty(&dqp->q_lru)) {
 848                list_add_tail(&dqp->q_lru, &qi->qi_lru_list);
 849                qi->qi_lru_count++;
 850                XFS_STATS_INC(xs_qm_dquot_unused);
 851        }
 852        mutex_unlock(&qi->qi_lru_lock);
 853
 854        /*
 855         * If we just added a udquot to the freelist, then we want to release
 856         * the gdquot reference that it (probably) has. Otherwise it'll keep
 857         * the gdquot from getting reclaimed.
 858         */
 859        gdqp = dqp->q_gdquot;
 860        if (gdqp) {
 861                xfs_dqlock(gdqp);
 862                dqp->q_gdquot = NULL;
 863        }
 864        xfs_dqunlock(dqp);
 865
 866        /*
 867         * If we had a group quota hint, release it now.
 868         */
 869        if (gdqp)
 870                xfs_qm_dqput(gdqp);
 871}
 872
 873/*
 874 * Release a reference to the dquot (decrement ref-count) and unlock it.
 875 *
 876 * If there is a group quota attached to this dquot, carefully release that
 877 * too without tripping over deadlocks'n'stuff.
 878 */
 879void
 880xfs_qm_dqput(
 881        struct xfs_dquot        *dqp)
 882{
 883        ASSERT(dqp->q_nrefs > 0);
 884        ASSERT(XFS_DQ_IS_LOCKED(dqp));
 885
 886        trace_xfs_dqput(dqp);
 887
 888        if (--dqp->q_nrefs > 0)
 889                xfs_dqunlock(dqp);
 890        else
 891                xfs_qm_dqput_final(dqp);
 892}
 893
 894/*
 895 * Release a dquot. Flush it if dirty, then dqput() it.
 896 * dquot must not be locked.
 897 */
 898void
 899xfs_qm_dqrele(
 900        xfs_dquot_t     *dqp)
 901{
 902        if (!dqp)
 903                return;
 904
 905        trace_xfs_dqrele(dqp);
 906
 907        xfs_dqlock(dqp);
 908        /*
 909         * We don't care to flush it if the dquot is dirty here.
 910         * That will create stutters that we want to avoid.
 911         * Instead we do a delayed write when we try to reclaim
 912         * a dirty dquot. Also xfs_sync will take part of the burden...
 913         */
 914        xfs_qm_dqput(dqp);
 915}
 916
 917/*
 918 * This is the dquot flushing I/O completion routine.  It is called
 919 * from interrupt level when the buffer containing the dquot is
 920 * flushed to disk.  It is responsible for removing the dquot logitem
 921 * from the AIL if it has not been re-logged, and unlocking the dquot's
 922 * flush lock. This behavior is very similar to that of inodes..
 923 */
 924STATIC void
 925xfs_qm_dqflush_done(
 926        struct xfs_buf          *bp,
 927        struct xfs_log_item     *lip)
 928{
 929        xfs_dq_logitem_t        *qip = (struct xfs_dq_logitem *)lip;
 930        xfs_dquot_t             *dqp = qip->qli_dquot;
 931        struct xfs_ail          *ailp = lip->li_ailp;
 932
 933        /*
 934         * We only want to pull the item from the AIL if its
 935         * location in the log has not changed since we started the flush.
 936         * Thus, we only bother if the dquot's lsn has
 937         * not changed. First we check the lsn outside the lock
 938         * since it's cheaper, and then we recheck while
 939         * holding the lock before removing the dquot from the AIL.
 940         */
 941        if ((lip->li_flags & XFS_LI_IN_AIL) &&
 942            lip->li_lsn == qip->qli_flush_lsn) {
 943
 944                /* xfs_trans_ail_delete() drops the AIL lock. */
 945                spin_lock(&ailp->xa_lock);
 946                if (lip->li_lsn == qip->qli_flush_lsn)
 947                        xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE);
 948                else
 949                        spin_unlock(&ailp->xa_lock);
 950        }
 951
 952        /*
 953         * Release the dq's flush lock since we're done with it.
 954         */
 955        xfs_dqfunlock(dqp);
 956}
 957
 958/*
 959 * Write a modified dquot to disk.
 960 * The dquot must be locked and the flush lock too taken by caller.
 961 * The flush lock will not be unlocked until the dquot reaches the disk,
 962 * but the dquot is free to be unlocked and modified by the caller
 963 * in the interim. Dquot is still locked on return. This behavior is
 964 * identical to that of inodes.
 965 */
 966int
 967xfs_qm_dqflush(
 968        struct xfs_dquot        *dqp,
 969        struct xfs_buf          **bpp)
 970{
 971        struct xfs_mount        *mp = dqp->q_mount;
 972        struct xfs_buf          *bp;
 973        struct xfs_disk_dquot   *ddqp;
 974        int                     error;
 975
 976        ASSERT(XFS_DQ_IS_LOCKED(dqp));
 977        ASSERT(!completion_done(&dqp->q_flush));
 978
 979        trace_xfs_dqflush(dqp);
 980
 981        *bpp = NULL;
 982
 983        xfs_qm_dqunpin_wait(dqp);
 984
 985        /*
 986         * This may have been unpinned because the filesystem is shutting
 987         * down forcibly. If that's the case we must not write this dquot
 988         * to disk, because the log record didn't make it to disk.
 989         *
 990         * We also have to remove the log item from the AIL in this case,
 991         * as we wait for an emptry AIL as part of the unmount process.
 992         */
 993        if (XFS_FORCED_SHUTDOWN(mp)) {
 994                struct xfs_log_item     *lip = &dqp->q_logitem.qli_item;
 995                dqp->dq_flags &= ~XFS_DQ_DIRTY;
 996
 997                spin_lock(&mp->m_ail->xa_lock);
 998                if (lip->li_flags & XFS_LI_IN_AIL)
 999                        xfs_trans_ail_delete(mp->m_ail, lip,
1000                                             SHUTDOWN_CORRUPT_INCORE);
1001                else
1002                        spin_unlock(&mp->m_ail->xa_lock);
1003                error = XFS_ERROR(EIO);
1004                goto out_unlock;
1005        }
1006
1007        /*
1008         * Get the buffer containing the on-disk dquot
1009         */
1010        error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
1011                                   mp->m_quotainfo->qi_dqchunklen, 0, &bp, NULL);
1012        if (error)
1013                goto out_unlock;
1014
1015        /*
1016         * Calculate the location of the dquot inside the buffer.
1017         */
1018        ddqp = bp->b_addr + dqp->q_bufoffset;
1019
1020        /*
1021         * A simple sanity check in case we got a corrupted dquot..
1022         */
1023        error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
1024                           XFS_QMOPT_DOWARN, "dqflush (incore copy)");
1025        if (error) {
1026                xfs_buf_relse(bp);
1027                xfs_dqfunlock(dqp);
1028                xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1029                return XFS_ERROR(EIO);
1030        }
1031
1032        /* This is the only portion of data that needs to persist */
1033        memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
1034
1035        /*
1036         * Clear the dirty field and remember the flush lsn for later use.
1037         */
1038        dqp->dq_flags &= ~XFS_DQ_DIRTY;
1039
1040        xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1041                                        &dqp->q_logitem.qli_item.li_lsn);
1042
1043        /*
1044         * Attach an iodone routine so that we can remove this dquot from the
1045         * AIL and release the flush lock once the dquot is synced to disk.
1046         */
1047        xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1048                                  &dqp->q_logitem.qli_item);
1049
1050        /*
1051         * If the buffer is pinned then push on the log so we won't
1052         * get stuck waiting in the write for too long.
1053         */
1054        if (xfs_buf_ispinned(bp)) {
1055                trace_xfs_dqflush_force(dqp);
1056                xfs_log_force(mp, 0);
1057        }
1058
1059        trace_xfs_dqflush_done(dqp);
1060        *bpp = bp;
1061        return 0;
1062
1063out_unlock:
1064        xfs_dqfunlock(dqp);
1065        return XFS_ERROR(EIO);
1066}
1067
1068/*
1069 * Lock two xfs_dquot structures.
1070 *
1071 * To avoid deadlocks we always lock the quota structure with
1072 * the lowerd id first.
1073 */
1074void
1075xfs_dqlock2(
1076        xfs_dquot_t     *d1,
1077        xfs_dquot_t     *d2)
1078{
1079        if (d1 && d2) {
1080                ASSERT(d1 != d2);
1081                if (be32_to_cpu(d1->q_core.d_id) >
1082                    be32_to_cpu(d2->q_core.d_id)) {
1083                        mutex_lock(&d2->q_qlock);
1084                        mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1085                } else {
1086                        mutex_lock(&d1->q_qlock);
1087                        mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1088                }
1089        } else if (d1) {
1090                mutex_lock(&d1->q_qlock);
1091        } else if (d2) {
1092                mutex_lock(&d2->q_qlock);
1093        }
1094}
1095
1096int __init
1097xfs_qm_init(void)
1098{
1099        xfs_qm_dqzone =
1100                kmem_zone_init(sizeof(struct xfs_dquot), "xfs_dquot");
1101        if (!xfs_qm_dqzone)
1102                goto out;
1103
1104        xfs_qm_dqtrxzone =
1105                kmem_zone_init(sizeof(struct xfs_dquot_acct), "xfs_dqtrx");
1106        if (!xfs_qm_dqtrxzone)
1107                goto out_free_dqzone;
1108
1109        return 0;
1110
1111out_free_dqzone:
1112        kmem_zone_destroy(xfs_qm_dqzone);
1113out:
1114        return -ENOMEM;
1115}
1116
1117void
1118xfs_qm_exit(void)
1119{
1120        kmem_zone_destroy(xfs_qm_dqtrxzone);
1121        kmem_zone_destroy(xfs_qm_dqzone);
1122}
1123
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