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xfs_dquot.c

/*
 * Copyright (c) 2000-2003 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_alloc.h"
#include "xfs_dmapi.h"
#include "xfs_quota.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_bmap.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_itable.h"
#include "xfs_rw.h"
#include "xfs_acl.h"
#include "xfs_attr.h"
#include "xfs_buf_item.h"
#include "xfs_trans_space.h"
#include "xfs_trans_priv.h"
#include "xfs_qm.h"


/*
   LOCK ORDER

   inode lock               (ilock)
   dquot hash-chain lock    (hashlock)
   xqm dquot freelist lock  (freelistlock
   mount's dquot list lock  (mplistlock)
   user dquot lock - lock ordering among dquots is based on the uid or gid
   group dquot lock - similar to udquots. Between the two dquots, the udquot
                  has to be locked first.
   pin lock - the dquot lock must be held to take this lock.
   flush lock - ditto.
*/

STATIC void       xfs_qm_dqflush_done(xfs_buf_t *, xfs_dq_logitem_t *);

#ifdef DEBUG
xfs_buftarg_t *xfs_dqerror_target;
int xfs_do_dqerror;
int xfs_dqreq_num;
int xfs_dqerror_mod = 33;
#endif

/*
 * Allocate and initialize a dquot. We don't always allocate fresh memory;
 * we try to reclaim a free dquot if the number of incore dquots are above
 * a threshold.
 * The only field inside the core that gets initialized at this point
 * is the d_id field. The idea is to fill in the entire q_core
 * when we read in the on disk dquot.
 */
STATIC xfs_dquot_t *
xfs_qm_dqinit(
      xfs_mount_t  *mp,
      xfs_dqid_t   id,
      uint       type)
{
      xfs_dquot_t *dqp;
      boolean_t   brandnewdquot;

      brandnewdquot = xfs_qm_dqalloc_incore(&dqp);
      dqp->dq_flags = type;
      dqp->q_core.d_id = cpu_to_be32(id);
      dqp->q_mount = mp;

      /*
       * No need to re-initialize these if this is a reclaimed dquot.
       */
      if (brandnewdquot) {
            dqp->dq_flnext = dqp->dq_flprev = dqp;
            mutex_init(&dqp->q_qlock);
            initnsema(&dqp->q_flock, 1, "fdq");
            sv_init(&dqp->q_pinwait, SV_DEFAULT, "pdq");

#ifdef XFS_DQUOT_TRACE
            dqp->q_trace = ktrace_alloc(DQUOT_TRACE_SIZE, KM_SLEEP);
            xfs_dqtrace_entry(dqp, "DQINIT");
#endif
      } else {
            /*
             * Only the q_core portion was zeroed in dqreclaim_one().
             * So, we need to reset others.
             */
             dqp->q_nrefs = 0;
             dqp->q_blkno = 0;
             dqp->MPL_NEXT = dqp->HL_NEXT = NULL;
             dqp->HL_PREVP = dqp->MPL_PREVP = NULL;
             dqp->q_bufoffset = 0;
             dqp->q_fileoffset = 0;
             dqp->q_transp = NULL;
             dqp->q_gdquot = NULL;
             dqp->q_res_bcount = 0;
             dqp->q_res_icount = 0;
             dqp->q_res_rtbcount = 0;
             dqp->q_pincount = 0;
             dqp->q_hash = NULL;
             ASSERT(dqp->dq_flnext == dqp->dq_flprev);

#ifdef XFS_DQUOT_TRACE
             ASSERT(dqp->q_trace);
             xfs_dqtrace_entry(dqp, "DQRECLAIMED_INIT");
#endif
       }

      /*
       * log item gets initialized later
       */
      return (dqp);
}

/*
 * This is called to free all the memory associated with a dquot
 */
void
xfs_qm_dqdestroy(
      xfs_dquot_t *dqp)
{
      ASSERT(! XFS_DQ_IS_ON_FREELIST(dqp));

      mutex_destroy(&dqp->q_qlock);
      freesema(&dqp->q_flock);
      sv_destroy(&dqp->q_pinwait);

#ifdef XFS_DQUOT_TRACE
      if (dqp->q_trace)
           ktrace_free(dqp->q_trace);
      dqp->q_trace = NULL;
#endif
      kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
      atomic_dec(&xfs_Gqm->qm_totaldquots);
}

/*
 * This is what a 'fresh' dquot inside a dquot chunk looks like on disk.
 */
STATIC void
xfs_qm_dqinit_core(
      xfs_dqid_t  id,
      uint        type,
      xfs_dqblk_t *d)
{
      /*
       * Caller has zero'd the entire dquot 'chunk' already.
       */
      d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
      d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
      d->dd_diskdq.d_id = cpu_to_be32(id);
      d->dd_diskdq.d_flags = type;
}


#ifdef XFS_DQUOT_TRACE
/*
 * Dquot tracing for debugging.
 */
/* ARGSUSED */
void
__xfs_dqtrace_entry(
      xfs_dquot_t *dqp,
      char        *func,
      void        *retaddr,
      xfs_inode_t *ip)
{
      xfs_dquot_t *udqp = NULL;
      xfs_ino_t   ino = 0;

      ASSERT(dqp->q_trace);
      if (ip) {
            ino = ip->i_ino;
            udqp = ip->i_udquot;
      }
      ktrace_enter(dqp->q_trace,
                 (void *)(__psint_t)DQUOT_KTRACE_ENTRY,
                 (void *)func,
                 (void *)(__psint_t)dqp->q_nrefs,
                 (void *)(__psint_t)dqp->dq_flags,
                 (void *)(__psint_t)dqp->q_res_bcount,
                 (void *)(__psint_t)be64_to_cpu(dqp->q_core.d_bcount),
                 (void *)(__psint_t)be64_to_cpu(dqp->q_core.d_icount),
                 (void *)(__psint_t)be64_to_cpu(dqp->q_core.d_blk_hardlimit),
                 (void *)(__psint_t)be64_to_cpu(dqp->q_core.d_blk_softlimit),
                 (void *)(__psint_t)be64_to_cpu(dqp->q_core.d_ino_hardlimit),
                 (void *)(__psint_t)be64_to_cpu(dqp->q_core.d_ino_softlimit),
                 (void *)(__psint_t)be32_to_cpu(dqp->q_core.d_id),
                 (void *)(__psint_t)current_pid(),
                 (void *)(__psint_t)ino,
                 (void *)(__psint_t)retaddr,
                 (void *)(__psint_t)udqp);
      return;
}
#endif


/*
 * If default limits are in force, push them into the dquot now.
 * We overwrite the dquot limits only if they are zero and this
 * is not the root dquot.
 */
void
xfs_qm_adjust_dqlimits(
      xfs_mount_t       *mp,
      xfs_disk_dquot_t  *d)
{
      xfs_quotainfo_t         *q = mp->m_quotainfo;

      ASSERT(d->d_id);

      if (q->qi_bsoftlimit && !d->d_blk_softlimit)
            d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
      if (q->qi_bhardlimit && !d->d_blk_hardlimit)
            d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
      if (q->qi_isoftlimit && !d->d_ino_softlimit)
            d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
      if (q->qi_ihardlimit && !d->d_ino_hardlimit)
            d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
      if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
            d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
      if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
            d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
}

/*
 * Check the limits and timers of a dquot and start or reset timers
 * if necessary.
 * This gets called even when quota enforcement is OFF, which makes our
 * life a little less complicated. (We just don't reject any quota
 * reservations in that case, when enforcement is off).
 * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
 * enforcement's off.
 * In contrast, warnings are a little different in that they don't
 * 'automatically' get started when limits get exceeded.  They do
 * get reset to zero, however, when we find the count to be under
 * the soft limit (they are only ever set non-zero via userspace).
 */
void
xfs_qm_adjust_dqtimers(
      xfs_mount_t       *mp,
      xfs_disk_dquot_t  *d)
{
      ASSERT(d->d_id);

#ifdef QUOTADEBUG
      if (d->d_blk_hardlimit)
            ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
                   be64_to_cpu(d->d_blk_hardlimit));
      if (d->d_ino_hardlimit)
            ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
                   be64_to_cpu(d->d_ino_hardlimit));
      if (d->d_rtb_hardlimit)
            ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
                   be64_to_cpu(d->d_rtb_hardlimit));
#endif
      if (!d->d_btimer) {
            if ((d->d_blk_softlimit &&
                 (be64_to_cpu(d->d_bcount) >=
                  be64_to_cpu(d->d_blk_softlimit))) ||
                (d->d_blk_hardlimit &&
                 (be64_to_cpu(d->d_bcount) >=
                  be64_to_cpu(d->d_blk_hardlimit)))) {
                  d->d_btimer = cpu_to_be32(get_seconds() +
                              XFS_QI_BTIMELIMIT(mp));
            } else {
                  d->d_bwarns = 0;
            }
      } else {
            if ((!d->d_blk_softlimit ||
                 (be64_to_cpu(d->d_bcount) <
                  be64_to_cpu(d->d_blk_softlimit))) &&
                (!d->d_blk_hardlimit ||
                (be64_to_cpu(d->d_bcount) <
                 be64_to_cpu(d->d_blk_hardlimit)))) {
                  d->d_btimer = 0;
            }
      }

      if (!d->d_itimer) {
            if ((d->d_ino_softlimit &&
                 (be64_to_cpu(d->d_icount) >=
                  be64_to_cpu(d->d_ino_softlimit))) ||
                (d->d_ino_hardlimit &&
                 (be64_to_cpu(d->d_icount) >=
                  be64_to_cpu(d->d_ino_hardlimit)))) {
                  d->d_itimer = cpu_to_be32(get_seconds() +
                              XFS_QI_ITIMELIMIT(mp));
            } else {
                  d->d_iwarns = 0;
            }
      } else {
            if ((!d->d_ino_softlimit ||
                 (be64_to_cpu(d->d_icount) <
                  be64_to_cpu(d->d_ino_softlimit)))  &&
                (!d->d_ino_hardlimit ||
                 (be64_to_cpu(d->d_icount) <
                  be64_to_cpu(d->d_ino_hardlimit)))) {
                  d->d_itimer = 0;
            }
      }

      if (!d->d_rtbtimer) {
            if ((d->d_rtb_softlimit &&
                 (be64_to_cpu(d->d_rtbcount) >=
                  be64_to_cpu(d->d_rtb_softlimit))) ||
                (d->d_rtb_hardlimit &&
                 (be64_to_cpu(d->d_rtbcount) >=
                  be64_to_cpu(d->d_rtb_hardlimit)))) {
                  d->d_rtbtimer = cpu_to_be32(get_seconds() +
                              XFS_QI_RTBTIMELIMIT(mp));
            } else {
                  d->d_rtbwarns = 0;
            }
      } else {
            if ((!d->d_rtb_softlimit ||
                 (be64_to_cpu(d->d_rtbcount) <
                  be64_to_cpu(d->d_rtb_softlimit))) &&
                (!d->d_rtb_hardlimit ||
                 (be64_to_cpu(d->d_rtbcount) <
                  be64_to_cpu(d->d_rtb_hardlimit)))) {
                  d->d_rtbtimer = 0;
            }
      }
}

/*
 * initialize a buffer full of dquots and log the whole thing
 */
STATIC void
xfs_qm_init_dquot_blk(
      xfs_trans_t *tp,
      xfs_mount_t *mp,
      xfs_dqid_t  id,
      uint        type,
      xfs_buf_t   *bp)
{
      xfs_dqblk_t *d;
      int         curid, i;

      ASSERT(tp);
      ASSERT(XFS_BUF_ISBUSY(bp));
      ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);

      d = (xfs_dqblk_t *)XFS_BUF_PTR(bp);

      /*
       * ID of the first dquot in the block - id's are zero based.
       */
      curid = id - (id % XFS_QM_DQPERBLK(mp));
      ASSERT(curid >= 0);
      memset(d, 0, BBTOB(XFS_QI_DQCHUNKLEN(mp)));
      for (i = 0; i < XFS_QM_DQPERBLK(mp); i++, d++, curid++)
            xfs_qm_dqinit_core(curid, type, d);
      xfs_trans_dquot_buf(tp, bp,
                      (type & XFS_DQ_USER ? XFS_BLI_UDQUOT_BUF :
                      ((type & XFS_DQ_PROJ) ? XFS_BLI_PDQUOT_BUF :
                       XFS_BLI_GDQUOT_BUF)));
      xfs_trans_log_buf(tp, bp, 0, BBTOB(XFS_QI_DQCHUNKLEN(mp)) - 1);
}



/*
 * Allocate a block and fill it with dquots.
 * This is called when the bmapi finds a hole.
 */
STATIC int
xfs_qm_dqalloc(
      xfs_trans_t **tpp,
      xfs_mount_t *mp,
      xfs_dquot_t *dqp,
      xfs_inode_t *quotip,
      xfs_fileoff_t     offset_fsb,
      xfs_buf_t   **O_bpp)
{
      xfs_fsblock_t     firstblock;
      xfs_bmap_free_t flist;
      xfs_bmbt_irec_t map;
      int         nmaps, error, committed;
      xfs_buf_t   *bp;
      xfs_trans_t *tp = *tpp;

      ASSERT(tp != NULL);
      xfs_dqtrace_entry(dqp, "DQALLOC");

      /*
       * Initialize the bmap freelist prior to calling bmapi code.
       */
      XFS_BMAP_INIT(&flist, &firstblock);
      xfs_ilock(quotip, XFS_ILOCK_EXCL);
      /*
       * Return if this type of quotas is turned off while we didn't
       * have an inode lock
       */
      if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
            xfs_iunlock(quotip, XFS_ILOCK_EXCL);
            return (ESRCH);
      }

      /*
       * xfs_trans_commit normally decrements the vnode ref count
       * when it unlocks the inode. Since we want to keep the quota
       * inode around, we bump the vnode ref count now.
       */
      VN_HOLD(XFS_ITOV(quotip));

      xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
      nmaps = 1;
      if ((error = xfs_bmapi(tp, quotip,
                        offset_fsb, XFS_DQUOT_CLUSTER_SIZE_FSB,
                        XFS_BMAPI_METADATA | XFS_BMAPI_WRITE,
                        &firstblock,
                        XFS_QM_DQALLOC_SPACE_RES(mp),
                        &map, &nmaps, &flist, NULL))) {
            goto error0;
      }
      ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
      ASSERT(nmaps == 1);
      ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
             (map.br_startblock != HOLESTARTBLOCK));

      /*
       * Keep track of the blkno to save a lookup later
       */
      dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);

      /* now we can just get the buffer (there's nothing to read yet) */
      bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
                         dqp->q_blkno,
                         XFS_QI_DQCHUNKLEN(mp),
                         0);
      if (!bp || (error = XFS_BUF_GETERROR(bp)))
            goto error1;
      /*
       * Make a chunk of dquots out of this buffer and log
       * the entire thing.
       */
      xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
                        dqp->dq_flags & XFS_DQ_ALLTYPES, bp);

      /*
       * xfs_bmap_finish() may commit the current transaction and
       * start a second transaction if the freelist is not empty.
       *
       * Since we still want to modify this buffer, we need to
       * ensure that the buffer is not released on commit of
       * the first transaction and ensure the buffer is added to the
       * second transaction.
       *
       * If there is only one transaction then don't stop the buffer
       * from being released when it commits later on.
       */

      xfs_trans_bhold(tp, bp);

      if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
            goto error1;
      }

      if (committed) {
            tp = *tpp;
            xfs_trans_bjoin(tp, bp);
      } else {
            xfs_trans_bhold_release(tp, bp);
      }

      *O_bpp = bp;
      return 0;

      error1:
      xfs_bmap_cancel(&flist);
      error0:
      xfs_iunlock(quotip, XFS_ILOCK_EXCL);

      return (error);
}

/*
 * Maps a dquot to the buffer containing its on-disk version.
 * This returns a ptr to the buffer containing the on-disk dquot
 * in the bpp param, and a ptr to the on-disk dquot within that buffer
 */
STATIC int
xfs_qm_dqtobp(
      xfs_trans_t       **tpp,
      xfs_dquot_t       *dqp,
      xfs_disk_dquot_t  **O_ddpp,
      xfs_buf_t         **O_bpp,
      uint              flags)
{
      xfs_bmbt_irec_t map;
      int         nmaps, error;
      xfs_buf_t   *bp;
      xfs_inode_t *quotip;
      xfs_mount_t *mp;
      xfs_disk_dquot_t *ddq;
      xfs_dqid_t  id;
      boolean_t   newdquot;
      xfs_trans_t *tp = (tpp ? *tpp : NULL);

      mp = dqp->q_mount;
      id = be32_to_cpu(dqp->q_core.d_id);
      nmaps = 1;
      newdquot = B_FALSE;

      /*
       * If we don't know where the dquot lives, find out.
       */
      if (dqp->q_blkno == (xfs_daddr_t) 0) {
            /* We use the id as an index */
            dqp->q_fileoffset = (xfs_fileoff_t)id / XFS_QM_DQPERBLK(mp);
            nmaps = 1;
            quotip = XFS_DQ_TO_QIP(dqp);
            xfs_ilock(quotip, XFS_ILOCK_SHARED);
            /*
             * Return if this type of quotas is turned off while we didn't
             * have an inode lock
             */
            if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
                  xfs_iunlock(quotip, XFS_ILOCK_SHARED);
                  return (ESRCH);
            }
            /*
             * Find the block map; no allocations yet
             */
            error = xfs_bmapi(NULL, quotip, dqp->q_fileoffset,
                          XFS_DQUOT_CLUSTER_SIZE_FSB,
                          XFS_BMAPI_METADATA,
                          NULL, 0, &map, &nmaps, NULL, NULL);

            xfs_iunlock(quotip, XFS_ILOCK_SHARED);
            if (error)
                  return (error);
            ASSERT(nmaps == 1);
            ASSERT(map.br_blockcount == 1);

            /*
             * offset of dquot in the (fixed sized) dquot chunk.
             */
            dqp->q_bufoffset = (id % XFS_QM_DQPERBLK(mp)) *
                  sizeof(xfs_dqblk_t);
            if (map.br_startblock == HOLESTARTBLOCK) {
                  /*
                   * We don't allocate unless we're asked to
                   */
                  if (!(flags & XFS_QMOPT_DQALLOC))
                        return (ENOENT);

                  ASSERT(tp);
                  if ((error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
                                    dqp->q_fileoffset, &bp)))
                        return (error);
                  tp = *tpp;
                  newdquot = B_TRUE;
            } else {
                  /*
                   * store the blkno etc so that we don't have to do the
                   * mapping all the time
                   */
                  dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
            }
      }
      ASSERT(dqp->q_blkno != DELAYSTARTBLOCK);
      ASSERT(dqp->q_blkno != HOLESTARTBLOCK);

      /*
       * Read in the buffer, unless we've just done the allocation
       * (in which case we already have the buf).
       */
      if (! newdquot) {
            xfs_dqtrace_entry(dqp, "DQTOBP READBUF");
            if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
                                     dqp->q_blkno,
                                     XFS_QI_DQCHUNKLEN(mp),
                                     0, &bp))) {
                  return (error);
            }
            if (error || !bp)
                  return XFS_ERROR(error);
      }
      ASSERT(XFS_BUF_ISBUSY(bp));
      ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);

      /*
       * calculate the location of the dquot inside the buffer.
       */
      ddq = (xfs_disk_dquot_t *)((char *)XFS_BUF_PTR(bp) + dqp->q_bufoffset);

      /*
       * A simple sanity check in case we got a corrupted dquot...
       */
      if (xfs_qm_dqcheck(ddq, id, dqp->dq_flags & XFS_DQ_ALLTYPES,
                     flags & (XFS_QMOPT_DQREPAIR|XFS_QMOPT_DOWARN),
                     "dqtobp")) {
            if (!(flags & XFS_QMOPT_DQREPAIR)) {
                  xfs_trans_brelse(tp, bp);
                  return XFS_ERROR(EIO);
            }
            XFS_BUF_BUSY(bp); /* We dirtied this */
      }

      *O_bpp = bp;
      *O_ddpp = ddq;

      return (0);
}


/*
 * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
 * and release the buffer immediately.
 *
 */
/* ARGSUSED */
STATIC int
xfs_qm_dqread(
      xfs_trans_t **tpp,
      xfs_dqid_t  id,
      xfs_dquot_t *dqp, /* dquot to get filled in */
      uint        flags)
{
      xfs_disk_dquot_t *ddqp;
      xfs_buf_t    *bp;
      int          error;
      xfs_trans_t  *tp;

      ASSERT(tpp);

      /*
       * get a pointer to the on-disk dquot and the buffer containing it
       * dqp already knows its own type (GROUP/USER).
       */
      xfs_dqtrace_entry(dqp, "DQREAD");
      if ((error = xfs_qm_dqtobp(tpp, dqp, &ddqp, &bp, flags))) {
            return (error);
      }
      tp = *tpp;

      /* copy everything from disk dquot to the incore dquot */
      memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
      ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);
      xfs_qm_dquot_logitem_init(dqp);

      /*
       * Reservation counters are defined as reservation plus current usage
       * to avoid having to add everytime.
       */
      dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
      dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
      dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);

      /* Mark the buf so that this will stay incore a little longer */
      XFS_BUF_SET_VTYPE_REF(bp, B_FS_DQUOT, XFS_DQUOT_REF);

      /*
       * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
       * So we need to release with xfs_trans_brelse().
       * The strategy here is identical to that of inodes; we lock
       * the dquot in xfs_qm_dqget() before making it accessible to
       * others. This is because dquots, like inodes, need a good level of
       * concurrency, and we don't want to take locks on the entire buffers
       * for dquot accesses.
       * Note also that the dquot buffer may even be dirty at this point, if
       * this particular dquot was repaired. We still aren't afraid to
       * brelse it because we have the changes incore.
       */
      ASSERT(XFS_BUF_ISBUSY(bp));
      ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
      xfs_trans_brelse(tp, bp);

      return (error);
}


/*
 * allocate an incore dquot from the kernel heap,
 * and fill its core with quota information kept on disk.
 * If XFS_QMOPT_DQALLOC is set, it'll allocate a dquot on disk
 * if it wasn't already allocated.
 */
STATIC int
xfs_qm_idtodq(
      xfs_mount_t *mp,
      xfs_dqid_t  id,    /* gid or uid, depending on type */
      uint        type,  /* UDQUOT or GDQUOT */
      uint        flags,       /* DQALLOC, DQREPAIR */
      xfs_dquot_t **O_dqpp)/* OUT : incore dquot, not locked */
{
      xfs_dquot_t *dqp;
      int         error;
      xfs_trans_t *tp;
      int         cancelflags=0;

      dqp = xfs_qm_dqinit(mp, id, type);
      tp = NULL;
      if (flags & XFS_QMOPT_DQALLOC) {
            tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
            if ((error = xfs_trans_reserve(tp,
                               XFS_QM_DQALLOC_SPACE_RES(mp),
                               XFS_WRITE_LOG_RES(mp) +
                                    BBTOB(XFS_QI_DQCHUNKLEN(mp)) - 1 +
                                    128,
                               0,
                               XFS_TRANS_PERM_LOG_RES,
                               XFS_WRITE_LOG_COUNT))) {
                  cancelflags = 0;
                  goto error0;
            }
            cancelflags = XFS_TRANS_RELEASE_LOG_RES;
      }

      /*
       * Read it from disk; xfs_dqread() takes care of
       * all the necessary initialization of dquot's fields (locks, etc)
       */
      if ((error = xfs_qm_dqread(&tp, id, dqp, flags))) {
            /*
             * This can happen if quotas got turned off (ESRCH),
             * or if the dquot didn't exist on disk and we ask to
             * allocate (ENOENT).
             */
            xfs_dqtrace_entry(dqp, "DQREAD FAIL");
            cancelflags |= XFS_TRANS_ABORT;
            goto error0;
      }
      if (tp) {
            if ((error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES)))
                  goto error1;
      }

      *O_dqpp = dqp;
      return (0);

 error0:
      ASSERT(error);
      if (tp)
            xfs_trans_cancel(tp, cancelflags);
 error1:
      xfs_qm_dqdestroy(dqp);
      *O_dqpp = NULL;
      return (error);
}

/*
 * Lookup a dquot in the incore dquot hashtable. We keep two separate
 * hashtables for user and group dquots; and, these are global tables
 * inside the XQM, not per-filesystem tables.
 * The hash chain must be locked by caller, and it is left locked
 * on return. Returning dquot is locked.
 */
STATIC int
xfs_qm_dqlookup(
      xfs_mount_t       *mp,
      xfs_dqid_t        id,
      xfs_dqhash_t            *qh,
      xfs_dquot_t       **O_dqpp)
{
      xfs_dquot_t       *dqp;
      uint              flist_locked;
      xfs_dquot_t       *d;

      ASSERT(XFS_DQ_IS_HASH_LOCKED(qh));

      flist_locked = B_FALSE;

      /*
       * Traverse the hashchain looking for a match
       */
      for (dqp = qh->qh_next; dqp != NULL; dqp = dqp->HL_NEXT) {
            /*
             * We already have the hashlock. We don't need the
             * dqlock to look at the id field of the dquot, since the
             * id can't be modified without the hashlock anyway.
             */
            if (be32_to_cpu(dqp->q_core.d_id) == id && dqp->q_mount == mp) {
                  xfs_dqtrace_entry(dqp, "DQFOUND BY LOOKUP");
                  /*
                   * All in core dquots must be on the dqlist of mp
                   */
                  ASSERT(dqp->MPL_PREVP != NULL);

                  xfs_dqlock(dqp);
                  if (dqp->q_nrefs == 0) {
                        ASSERT (XFS_DQ_IS_ON_FREELIST(dqp));
                        if (! xfs_qm_freelist_lock_nowait(xfs_Gqm)) {
                              xfs_dqtrace_entry(dqp, "DQLOOKUP: WANT");

                              /*
                               * We may have raced with dqreclaim_one()
                               * (and lost). So, flag that we don't
                               * want the dquot to be reclaimed.
                               */
                              dqp->dq_flags |= XFS_DQ_WANT;
                              xfs_dqunlock(dqp);
                              xfs_qm_freelist_lock(xfs_Gqm);
                              xfs_dqlock(dqp);
                              dqp->dq_flags &= ~(XFS_DQ_WANT);
                        }
                        flist_locked = B_TRUE;
                  }

                  /*
                   * id couldn't have changed; we had the hashlock all
                   * along
                   */
                  ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);

                  if (flist_locked) {
                        if (dqp->q_nrefs != 0) {
                              xfs_qm_freelist_unlock(xfs_Gqm);
                              flist_locked = B_FALSE;
                        } else {
                              /*
                               * take it off the freelist
                               */
                              xfs_dqtrace_entry(dqp,
                                          "DQLOOKUP: TAKEOFF FL");
                              XQM_FREELIST_REMOVE(dqp);
                              /* xfs_qm_freelist_print(&(xfs_Gqm->
                                          qm_dqfreelist),
                                          "after removal"); */
                        }
                  }

                  /*
                   * grab a reference
                   */
                  XFS_DQHOLD(dqp);

                  if (flist_locked)
                        xfs_qm_freelist_unlock(xfs_Gqm);
                  /*
                   * move the dquot to the front of the hashchain
                   */
                  ASSERT(XFS_DQ_IS_HASH_LOCKED(qh));
                  if (dqp->HL_PREVP != &qh->qh_next) {
                        xfs_dqtrace_entry(dqp,
                                      "DQLOOKUP: HASH MOVETOFRONT");
                        if ((d = dqp->HL_NEXT))
                              d->HL_PREVP = dqp->HL_PREVP;
                        *(dqp->HL_PREVP) = d;
                        d = qh->qh_next;
                        d->HL_PREVP = &dqp->HL_NEXT;
                        dqp->HL_NEXT = d;
                        dqp->HL_PREVP = &qh->qh_next;
                        qh->qh_next = dqp;
                  }
                  xfs_dqtrace_entry(dqp, "LOOKUP END");
                  *O_dqpp = dqp;
                  ASSERT(XFS_DQ_IS_HASH_LOCKED(qh));
                  return (0);
            }
      }

      *O_dqpp = NULL;
      ASSERT(XFS_DQ_IS_HASH_LOCKED(qh));
      return (1);
}

/*
 * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
 * a locked dquot, doing an allocation (if requested) as needed.
 * When both an inode and an id are given, the inode's id takes precedence.
 * That is, if the id changes while we don't hold the ilock inside this
 * function, the new dquot is returned, not necessarily the one requested
 * in the id argument.
 */
int
xfs_qm_dqget(
      xfs_mount_t *mp,
      xfs_inode_t *ip,    /* locked inode (optional) */
      xfs_dqid_t  id,     /* uid/projid/gid depending on type */
      uint        type,   /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
      uint        flags,        /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
      xfs_dquot_t **O_dqpp) /* OUT : locked incore dquot */
{
      xfs_dquot_t *dqp;
      xfs_dqhash_t      *h;
      uint        version;
      int         error;

      ASSERT(XFS_IS_QUOTA_RUNNING(mp));
      if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
          (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
          (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
            return (ESRCH);
      }
      h = XFS_DQ_HASH(mp, id, type);

#ifdef DEBUG
      if (xfs_do_dqerror) {
            if ((xfs_dqerror_target == mp->m_ddev_targp) &&
                (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
                  cmn_err(CE_DEBUG, "Returning error in dqget");
                  return (EIO);
            }
      }
#endif

 again:

#ifdef DEBUG
      ASSERT(type == XFS_DQ_USER ||
             type == XFS_DQ_PROJ ||
             type == XFS_DQ_GROUP);
      if (ip) {
            ASSERT(XFS_ISLOCKED_INODE_EXCL(ip));
            if (type == XFS_DQ_USER)
                  ASSERT(ip->i_udquot == NULL);
            else
                  ASSERT(ip->i_gdquot == NULL);
      }
#endif
      XFS_DQ_HASH_LOCK(h);

      /*
       * Look in the cache (hashtable).
       * The chain is kept locked during lookup.
       */
      if (xfs_qm_dqlookup(mp, id, h, O_dqpp) == 0) {
            XQM_STATS_INC(xqmstats.xs_qm_dqcachehits);
            /*
             * The dquot was found, moved to the front of the chain,
             * taken off the freelist if it was on it, and locked
             * at this point. Just unlock the hashchain and return.
             */
            ASSERT(*O_dqpp);
            ASSERT(XFS_DQ_IS_LOCKED(*O_dqpp));
            XFS_DQ_HASH_UNLOCK(h);
            xfs_dqtrace_entry(*O_dqpp, "DQGET DONE (FROM CACHE)");
            return (0); /* success */
      }
      XQM_STATS_INC(xqmstats.xs_qm_dqcachemisses);

      /*
       * Dquot cache miss. We don't want to keep the inode lock across
       * a (potential) disk read. Also we don't want to deal with the lock
       * ordering between quotainode and this inode. OTOH, dropping the inode
       * lock here means dealing with a chown that can happen before
       * we re-acquire the lock.
       */
      if (ip)
            xfs_iunlock(ip, XFS_ILOCK_EXCL);
      /*
       * Save the hashchain version stamp, and unlock the chain, so that
       * we don't keep the lock across a disk read
       */
      version = h->qh_version;
      XFS_DQ_HASH_UNLOCK(h);

      /*
       * Allocate the dquot on the kernel heap, and read the ondisk
       * portion off the disk. Also, do all the necessary initialization
       * This can return ENOENT if dquot didn't exist on disk and we didn't
       * ask it to allocate; ESRCH if quotas got turned off suddenly.
       */
      if ((error = xfs_qm_idtodq(mp, id, type,
                          flags & (XFS_QMOPT_DQALLOC|XFS_QMOPT_DQREPAIR|
                                 XFS_QMOPT_DOWARN),
                          &dqp))) {
            if (ip)
                  xfs_ilock(ip, XFS_ILOCK_EXCL);
            return (error);
      }

      /*
       * See if this is mount code calling to look at the overall quota limits
       * which are stored in the id == 0 user or group's dquot.
       * Since we may not have done a quotacheck by this point, just return
       * the dquot without attaching it to any hashtables, lists, etc, or even
       * taking a reference.
       * The caller must dqdestroy this once done.
       */
      if (flags & XFS_QMOPT_DQSUSER) {
            ASSERT(id == 0);
            ASSERT(! ip);
            goto dqret;
      }

      /*
       * Dquot lock comes after hashlock in the lock ordering
       */
      if (ip) {
            xfs_ilock(ip, XFS_ILOCK_EXCL);
            if (! XFS_IS_DQTYPE_ON(mp, type)) {
                  /* inode stays locked on return */
                  xfs_qm_dqdestroy(dqp);
                  return XFS_ERROR(ESRCH);
            }
            /*
             * A dquot could be attached to this inode by now, since
             * we had dropped the ilock.
             */
            if (type == XFS_DQ_USER) {
                  if (ip->i_udquot) {
                        xfs_qm_dqdestroy(dqp);
                        dqp = ip->i_udquot;
                        xfs_dqlock(dqp);
                        goto dqret;
                  }
            } else {
                  if (ip->i_gdquot) {
                        xfs_qm_dqdestroy(dqp);
                        dqp = ip->i_gdquot;
                        xfs_dqlock(dqp);
                        goto dqret;
                  }
            }
      }

      /*
       * Hashlock comes after ilock in lock order
       */
      XFS_DQ_HASH_LOCK(h);
      if (version != h->qh_version) {
            xfs_dquot_t *tmpdqp;
            /*
             * Now, see if somebody else put the dquot in the
             * hashtable before us. This can happen because we didn't
             * keep the hashchain lock. We don't have to worry about
             * lock order between the two dquots here since dqp isn't
             * on any findable lists yet.
             */
            if (xfs_qm_dqlookup(mp, id, h, &tmpdqp) == 0) {
                  /*
                   * Duplicate found. Just throw away the new dquot
                   * and start over.
                   */
                  xfs_qm_dqput(tmpdqp);
                  XFS_DQ_HASH_UNLOCK(h);
                  xfs_qm_dqdestroy(dqp);
                  XQM_STATS_INC(xqmstats.xs_qm_dquot_dups);
                  goto again;
            }
      }

      /*
       * Put the dquot at the beginning of the hash-chain and mp's list
       * LOCK ORDER: hashlock, freelistlock, mplistlock, udqlock, gdqlock ..
       */
      ASSERT(XFS_DQ_IS_HASH_LOCKED(h));
      dqp->q_hash = h;
      XQM_HASHLIST_INSERT(h, dqp);

      /*
       * Attach this dquot to this filesystem's list of all dquots,
       * kept inside the mount structure in m_quotainfo field
       */
      xfs_qm_mplist_lock(mp);

      /*
       * We return a locked dquot to the caller, with a reference taken
       */
      xfs_dqlock(dqp);
      dqp->q_nrefs = 1;

      XQM_MPLIST_INSERT(&(XFS_QI_MPL_LIST(mp)), dqp);

      xfs_qm_mplist_unlock(mp);
      XFS_DQ_HASH_UNLOCK(h);
 dqret:
      ASSERT((ip == NULL) || XFS_ISLOCKED_INODE_EXCL(ip));
      xfs_dqtrace_entry(dqp, "DQGET DONE");
      *O_dqpp = dqp;
      return (0);
}


/*
 * Release a reference to the dquot (decrement ref-count)
 * and unlock it. If there is a group quota attached to this
 * dquot, carefully release that too without tripping over
 * deadlocks'n'stuff.
 */
void
xfs_qm_dqput(
      xfs_dquot_t *dqp)
{
      xfs_dquot_t *gdqp;

      ASSERT(dqp->q_nrefs > 0);
      ASSERT(XFS_DQ_IS_LOCKED(dqp));
      xfs_dqtrace_entry(dqp, "DQPUT");

      if (dqp->q_nrefs != 1) {
            dqp->q_nrefs--;
            xfs_dqunlock(dqp);
            return;
      }

      /*
       * drop the dqlock and acquire the freelist and dqlock
       * in the right order; but try to get it out-of-order first
       */
      if (! xfs_qm_freelist_lock_nowait(xfs_Gqm)) {
            xfs_dqtrace_entry(dqp, "DQPUT: FLLOCK-WAIT");
            xfs_dqunlock(dqp);
            xfs_qm_freelist_lock(xfs_Gqm);
            xfs_dqlock(dqp);
      }

      while (1) {
            gdqp = NULL;

            /* We can't depend on nrefs being == 1 here */
            if (--dqp->q_nrefs == 0) {
                  xfs_dqtrace_entry(dqp, "DQPUT: ON FREELIST");
                  /*
                   * insert at end of the freelist.
                   */
                  XQM_FREELIST_INSERT(&(xfs_Gqm->qm_dqfreelist), dqp);

                  /*
                   * If we just added a udquot to the freelist, then
                   * we want to release the gdquot reference that
                   * it (probably) has. Otherwise it'll keep the
                   * gdquot from getting reclaimed.
                   */
                  if ((gdqp = dqp->q_gdquot)) {
                        /*
                         * Avoid a recursive dqput call
                         */
                        xfs_dqlock(gdqp);
                        dqp->q_gdquot = NULL;
                  }

                  /* xfs_qm_freelist_print(&(xfs_Gqm->qm_dqfreelist),
                     "@@@@@++ Free list (after append) @@@@@+");
                     */
            }
            xfs_dqunlock(dqp);

            /*
             * If we had a group quota inside the user quota as a hint,
             * release it now.
             */
            if (! gdqp)
                  break;
            dqp = gdqp;
      }
      xfs_qm_freelist_unlock(xfs_Gqm);
}

/*
 * Release a dquot. Flush it if dirty, then dqput() it.
 * dquot must not be locked.
 */
void
xfs_qm_dqrele(
      xfs_dquot_t *dqp)
{
      ASSERT(dqp);
      xfs_dqtrace_entry(dqp, "DQRELE");

      xfs_dqlock(dqp);
      /*
       * We don't care to flush it if the dquot is dirty here.
       * That will create stutters that we want to avoid.
       * Instead we do a delayed write when we try to reclaim
       * a dirty dquot. Also xfs_sync will take part of the burden...
       */
      xfs_qm_dqput(dqp);
}


/*
 * Write a modified dquot to disk.
 * The dquot must be locked and the flush lock too taken by caller.
 * The flush lock will not be unlocked until the dquot reaches the disk,
 * but the dquot is free to be unlocked and modified by the caller
 * in the interim. Dquot is still locked on return. This behavior is
 * identical to that of inodes.
 */
int
xfs_qm_dqflush(
      xfs_dquot_t       *dqp,
      uint              flags)
{
      xfs_mount_t       *mp;
      xfs_buf_t         *bp;
      xfs_disk_dquot_t  *ddqp;
      int               error;
      SPLDECL(s);

      ASSERT(XFS_DQ_IS_LOCKED(dqp));
      ASSERT(XFS_DQ_IS_FLUSH_LOCKED(dqp));
      xfs_dqtrace_entry(dqp, "DQFLUSH");

      /*
       * If not dirty, nada.
       */
      if (!XFS_DQ_IS_DIRTY(dqp)) {
            xfs_dqfunlock(dqp);
            return (0);
      }

      /*
       * Cant flush a pinned dquot. Wait for it.
       */
      xfs_qm_dqunpin_wait(dqp);

      /*
       * This may have been unpinned because the filesystem is shutting
       * down forcibly. If that's the case we must not write this dquot
       * to disk, because the log record didn't make it to disk!
       */
      if (XFS_FORCED_SHUTDOWN(dqp->q_mount)) {
            dqp->dq_flags &= ~(XFS_DQ_DIRTY);
            xfs_dqfunlock(dqp);
            return XFS_ERROR(EIO);
      }

      /*
       * Get the buffer containing the on-disk dquot
       * We don't need a transaction envelope because we know that the
       * the ondisk-dquot has already been allocated for.
       */
      if ((error = xfs_qm_dqtobp(NULL, dqp, &ddqp, &bp, XFS_QMOPT_DOWARN))) {
            xfs_dqtrace_entry(dqp, "DQTOBP FAIL");
            ASSERT(error != ENOENT);
            /*
             * Quotas could have gotten turned off (ESRCH)
             */
            xfs_dqfunlock(dqp);
            return (error);
      }

      if (xfs_qm_dqcheck(&dqp->q_core, be32_to_cpu(ddqp->d_id),
                     0, XFS_QMOPT_DOWARN, "dqflush (incore copy)")) {
            xfs_force_shutdown(dqp->q_mount, SHUTDOWN_CORRUPT_INCORE);
            return XFS_ERROR(EIO);
      }

      /* This is the only portion of data that needs to persist */
      memcpy(ddqp, &(dqp->q_core), sizeof(xfs_disk_dquot_t));

      /*
       * Clear the dirty field and remember the flush lsn for later use.
       */
      dqp->dq_flags &= ~(XFS_DQ_DIRTY);
      mp = dqp->q_mount;

      /* lsn is 64 bits */
      AIL_LOCK(mp, s);
      dqp->q_logitem.qli_flush_lsn = dqp->q_logitem.qli_item.li_lsn;
      AIL_UNLOCK(mp, s);

      /*
       * Attach an iodone routine so that we can remove this dquot from the
       * AIL and release the flush lock once the dquot is synced to disk.
       */
      xfs_buf_attach_iodone(bp, (void(*)(xfs_buf_t *, xfs_log_item_t *))
                        xfs_qm_dqflush_done, &(dqp->q_logitem.qli_item));
      /*
       * If the buffer is pinned then push on the log so we won't
       * get stuck waiting in the write for too long.
       */
      if (XFS_BUF_ISPINNED(bp)) {
            xfs_dqtrace_entry(dqp, "DQFLUSH LOG FORCE");
            xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE);
      }

      if (flags & XFS_QMOPT_DELWRI) {
            xfs_bdwrite(mp, bp);
      } else if (flags & XFS_QMOPT_ASYNC) {
            xfs_bawrite(mp, bp);
      } else {
            error = xfs_bwrite(mp, bp);
      }
      xfs_dqtrace_entry(dqp, "DQFLUSH END");
      /*
       * dqp is still locked, but caller is free to unlock it now.
       */
      return (error);

}

/*
 * This is the dquot flushing I/O completion routine.  It is called
 * from interrupt level when the buffer containing the dquot is
 * flushed to disk.  It is responsible for removing the dquot logitem
 * from the AIL if it has not been re-logged, and unlocking the dquot's
 * flush lock. This behavior is very similar to that of inodes..
 */
/*ARGSUSED*/
STATIC void
xfs_qm_dqflush_done(
      xfs_buf_t         *bp,
      xfs_dq_logitem_t  *qip)
{
      xfs_dquot_t       *dqp;
      SPLDECL(s);

      dqp = qip->qli_dquot;

      /*
       * We only want to pull the item from the AIL if its
       * location in the log has not changed since we started the flush.
       * Thus, we only bother if the dquot's lsn has
       * not changed. First we check the lsn outside the lock
       * since it's cheaper, and then we recheck while
       * holding the lock before removing the dquot from the AIL.
       */
      if ((qip->qli_item.li_flags & XFS_LI_IN_AIL) &&
          qip->qli_item.li_lsn == qip->qli_flush_lsn) {

            AIL_LOCK(dqp->q_mount, s);
            /*
             * xfs_trans_delete_ail() drops the AIL lock.
             */
            if (qip->qli_item.li_lsn == qip->qli_flush_lsn)
                  xfs_trans_delete_ail(dqp->q_mount,
                                   (xfs_log_item_t*)qip, s);
            else
                  AIL_UNLOCK(dqp->q_mount, s);
      }

      /*
       * Release the dq's flush lock since we're done with it.
       */
      xfs_dqfunlock(dqp);
}


int
xfs_qm_dqflock_nowait(
      xfs_dquot_t *dqp)
{
      int locked;

      locked = cpsema(&((dqp)->q_flock));

      /* XXX ifdef these out */
      if (locked)
            (dqp)->dq_flags |= XFS_DQ_FLOCKED;
      return (locked);
}


int
xfs_qm_dqlock_nowait(
      xfs_dquot_t *dqp)
{
      return (mutex_trylock(&((dqp)->q_qlock)));
}

void
xfs_dqlock(
      xfs_dquot_t *dqp)
{
      mutex_lock(&(dqp->q_qlock));
}

void
xfs_dqunlock(
      xfs_dquot_t *dqp)
{
      mutex_unlock(&(dqp->q_qlock));
      if (dqp->q_logitem.qli_dquot == dqp) {
            /* Once was dqp->q_mount, but might just have been cleared */
            xfs_trans_unlocked_item(dqp->q_logitem.qli_item.li_mountp,
                              (xfs_log_item_t*)&(dqp->q_logitem));
      }
}


void
xfs_dqunlock_nonotify(
      xfs_dquot_t *dqp)
{
      mutex_unlock(&(dqp->q_qlock));
}

void
xfs_dqlock2(
      xfs_dquot_t *d1,
      xfs_dquot_t *d2)
{
      if (d1 && d2) {
            ASSERT(d1 != d2);
            if (be32_to_cpu(d1->q_core.d_id) >
                be32_to_cpu(d2->q_core.d_id)) {
                  xfs_dqlock(d2);
                  xfs_dqlock(d1);
            } else {
                  xfs_dqlock(d1);
                  xfs_dqlock(d2);
            }
      } else {
            if (d1) {
                  xfs_dqlock(d1);
            } else if (d2) {
                  xfs_dqlock(d2);
            }
      }
}


/*
 * Take a dquot out of the mount's dqlist as well as the hashlist.
 * This is called via unmount as well as quotaoff, and the purge
 * will always succeed unless there are soft (temp) references
 * outstanding.
 *
 * This returns 0 if it was purged, 1 if it wasn't. It's not an error code
 * that we're returning! XXXsup - not cool.
 */
/* ARGSUSED */
int
xfs_qm_dqpurge(
      xfs_dquot_t *dqp,
      uint        flags)
{
      xfs_dqhash_t      *thishash;
      xfs_mount_t *mp;

      mp = dqp->q_mount;

      ASSERT(XFS_QM_IS_MPLIST_LOCKED(mp));
      ASSERT(XFS_DQ_IS_HASH_LOCKED(dqp->q_hash));

      xfs_dqlock(dqp);
      /*
       * We really can't afford to purge a dquot that is
       * referenced, because these are hard refs.
       * It shouldn't happen in general because we went thru _all_ inodes in
       * dqrele_all_inodes before calling this and didn't let the mountlock go.
       * However it is possible that we have dquots with temporary
       * references that are not attached to an inode. e.g. see xfs_setattr().
       */
      if (dqp->q_nrefs != 0) {
            xfs_dqunlock(dqp);
            XFS_DQ_HASH_UNLOCK(dqp->q_hash);
            return (1);
      }

      ASSERT(XFS_DQ_IS_ON_FREELIST(dqp));

      /*
       * If we're turning off quotas, we have to make sure that, for
       * example, we don't delete quota disk blocks while dquots are
       * in the process of getting written to those disk blocks.
       * This dquot might well be on AIL, and we can't leave it there
       * if we're turning off quotas. Basically, we need this flush
       * lock, and are willing to block on it.
       */
      if (! xfs_qm_dqflock_nowait(dqp)) {
            /*
             * Block on the flush lock after nudging dquot buffer,
             * if it is incore.
             */
            xfs_qm_dqflock_pushbuf_wait(dqp);
      }

      /*
       * XXXIf we're turning this type of quotas off, we don't care
       * about the dirty metadata sitting in this dquot. OTOH, if
       * we're unmounting, we do care, so we flush it and wait.
       */
      if (XFS_DQ_IS_DIRTY(dqp)) {
            xfs_dqtrace_entry(dqp, "DQPURGE ->DQFLUSH: DQDIRTY");
            /* dqflush unlocks dqflock */
            /*
             * Given that dqpurge is a very rare occurrence, it is OK
             * that we're holding the hashlist and mplist locks
             * across the disk write. But, ... XXXsup
             *
             * We don't care about getting disk errors here. We need
             * to purge this dquot anyway, so we go ahead regardless.
             */
            (void) xfs_qm_dqflush(dqp, XFS_QMOPT_SYNC);
            xfs_dqflock(dqp);
      }
      ASSERT(dqp->q_pincount == 0);
      ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
             !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));

      thishash = dqp->q_hash;
      XQM_HASHLIST_REMOVE(thishash, dqp);
      XQM_MPLIST_REMOVE(&(XFS_QI_MPL_LIST(mp)), dqp);
      /*
       * XXX Move this to the front of the freelist, if we can get the
       * freelist lock.
       */
      ASSERT(XFS_DQ_IS_ON_FREELIST(dqp));

      dqp->q_mount = NULL;
      dqp->q_hash = NULL;
      dqp->dq_flags = XFS_DQ_INACTIVE;
      memset(&dqp->q_core, 0, sizeof(dqp->q_core));
      xfs_dqfunlock(dqp);
      xfs_dqunlock(dqp);
      XFS_DQ_HASH_UNLOCK(thishash);
      return (0);
}


#ifdef QUOTADEBUG
void
xfs_qm_dqprint(xfs_dquot_t *dqp)
{
      cmn_err(CE_DEBUG, "-----------KERNEL DQUOT----------------");
      cmn_err(CE_DEBUG, "---- dquotID =  %d",
            (int)be32_to_cpu(dqp->q_core.d_id));
      cmn_err(CE_DEBUG, "---- type    =  %s", DQFLAGTO_TYPESTR(dqp));
      cmn_err(CE_DEBUG, "---- fs      =  0x%p", dqp->q_mount);
      cmn_err(CE_DEBUG, "---- blkno   =  0x%x", (int) dqp->q_blkno);
      cmn_err(CE_DEBUG, "---- boffset =  0x%x", (int) dqp->q_bufoffset);
      cmn_err(CE_DEBUG, "---- blkhlimit =  %Lu (0x%x)",
            be64_to_cpu(dqp->q_core.d_blk_hardlimit),
            (int)be64_to_cpu(dqp->q_core.d_blk_hardlimit));
      cmn_err(CE_DEBUG, "---- blkslimit =  %Lu (0x%x)",
            be64_to_cpu(dqp->q_core.d_blk_softlimit),
            (int)be64_to_cpu(dqp->q_core.d_blk_softlimit));
      cmn_err(CE_DEBUG, "---- inohlimit =  %Lu (0x%x)",
            be64_to_cpu(dqp->q_core.d_ino_hardlimit),
            (int)be64_to_cpu(dqp->q_core.d_ino_hardlimit));
      cmn_err(CE_DEBUG, "---- inoslimit =  %Lu (0x%x)",
            be64_to_cpu(dqp->q_core.d_ino_softlimit),
            (int)be64_to_cpu(dqp->q_core.d_ino_softlimit));
      cmn_err(CE_DEBUG, "---- bcount  =  %Lu (0x%x)",
            be64_to_cpu(dqp->q_core.d_bcount),
            (int)be64_to_cpu(dqp->q_core.d_bcount));
      cmn_err(CE_DEBUG, "---- icount  =  %Lu (0x%x)",
            be64_to_cpu(dqp->q_core.d_icount),
            (int)be64_to_cpu(dqp->q_core.d_icount));
      cmn_err(CE_DEBUG, "---- btimer  =  %d",
            (int)be32_to_cpu(dqp->q_core.d_btimer));
      cmn_err(CE_DEBUG, "---- itimer  =  %d",
            (int)be32_to_cpu(dqp->q_core.d_itimer));
      cmn_err(CE_DEBUG, "---------------------------");
}
#endif

/*
 * Give the buffer a little push if it is incore and
 * wait on the flush lock.
 */
void
xfs_qm_dqflock_pushbuf_wait(
      xfs_dquot_t *dqp)
{
      xfs_buf_t   *bp;

      /*
       * Check to see if the dquot has been flushed delayed
       * write.  If so, grab its buffer and send it
       * out immediately.  We'll be able to acquire
       * the flush lock when the I/O completes.
       */
      bp = xfs_incore(dqp->q_mount->m_ddev_targp, dqp->q_blkno,
                XFS_QI_DQCHUNKLEN(dqp->q_mount),
                XFS_INCORE_TRYLOCK);
      if (bp != NULL) {
            if (XFS_BUF_ISDELAYWRITE(bp)) {
                  if (XFS_BUF_ISPINNED(bp)) {
                        xfs_log_force(dqp->q_mount,
                                    (xfs_lsn_t)0,
                                    XFS_LOG_FORCE);
                  }
                  xfs_bawrite(dqp->q_mount, bp);
            } else {
                  xfs_buf_relse(bp);
            }
      }
      xfs_dqflock(dqp);
}

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