xfs_trans_dquot.c

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/*
 * Copyright (c) 2000-2002 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_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_alloc.h"
#include "xfs_quota.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_itable.h"
#include "xfs_bmap.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_attr.h"
#include "xfs_buf_item.h"
#include "xfs_trans_priv.h"
#include "xfs_qm.h"

STATIC void xfs_trans_alloc_dqinfo(xfs_trans_t *);

/*
 * Add the locked dquot to the transaction.
 * The dquot must be locked, and it cannot be associated with any
 * transaction.
 */
void
xfs_trans_dqjoin(
    xfs_trans_t *tp,
    xfs_dquot_t *dqp)
{
    ASSERT(dqp->q_transp != tp);
    ASSERT(XFS_DQ_IS_LOCKED(dqp));
    ASSERT(dqp->q_logitem.qli_dquot == dqp);

    /*
     * Get a log_item_desc to point at the new item.
     */
    xfs_trans_add_item(tp, &dqp->q_logitem.qli_item);

    /*
     * Initialize d_transp so we can later determine if this dquot is
     * associated with this transaction.
     */
    dqp->q_transp = tp;
}


/*
 * This is called to mark the dquot as needing
 * to be logged when the transaction is committed.  The dquot must
 * already be associated with the given transaction.
 * Note that it marks the entire transaction as dirty. In the ordinary
 * case, this gets called via xfs_trans_commit, after the transaction
 * is already dirty. However, there's nothing stop this from getting
 * called directly, as done by xfs_qm_scall_setqlim. Hence, the TRANS_DIRTY
 * flag.
 */
void
xfs_trans_log_dquot(
    xfs_trans_t *tp,
    xfs_dquot_t *dqp)
{
    ASSERT(dqp->q_transp == tp);
    ASSERT(XFS_DQ_IS_LOCKED(dqp));

    tp->t_flags |= XFS_TRANS_DIRTY;
    dqp->q_logitem.qli_item.li_desc->lid_flags |= XFS_LID_DIRTY;
}

/*
 * Carry forward whatever is left of the quota blk reservation to
 * the spanky new transaction
 */
void
xfs_trans_dup_dqinfo(
    xfs_trans_t *otp,
    xfs_trans_t *ntp)
{
    xfs_dqtrx_t *oq, *nq;
    int     i,j;
    xfs_dqtrx_t *oqa, *nqa;

    if (!otp->t_dqinfo)
        return;

    xfs_trans_alloc_dqinfo(ntp);
    oqa = otp->t_dqinfo->dqa_usrdquots;
    nqa = ntp->t_dqinfo->dqa_usrdquots;

    /*
     * Because the quota blk reservation is carried forward,
     * it is also necessary to carry forward the DQ_DIRTY flag.
     */
    if(otp->t_flags & XFS_TRANS_DQ_DIRTY)
        ntp->t_flags |= XFS_TRANS_DQ_DIRTY;

    for (j = 0; j < 2; j++) {
        for (i = 0; i < XFS_QM_TRANS_MAXDQS; i++) {
            if (oqa[i].qt_dquot == NULL)
                break;
            oq = &oqa[i];
            nq = &nqa[i];

            nq->qt_dquot = oq->qt_dquot;
            nq->qt_bcount_delta = nq->qt_icount_delta = 0;
            nq->qt_rtbcount_delta = 0;

            /*
             * Transfer whatever is left of the reservations.
             */
            nq->qt_blk_res = oq->qt_blk_res - oq->qt_blk_res_used;
            oq->qt_blk_res = oq->qt_blk_res_used;

            nq->qt_rtblk_res = oq->qt_rtblk_res -
                oq->qt_rtblk_res_used;
            oq->qt_rtblk_res = oq->qt_rtblk_res_used;

            nq->qt_ino_res = oq->qt_ino_res - oq->qt_ino_res_used;
            oq->qt_ino_res = oq->qt_ino_res_used;

        }
        oqa = otp->t_dqinfo->dqa_grpdquots;
        nqa = ntp->t_dqinfo->dqa_grpdquots;
    }
}

/*
 * Wrap around mod_dquot to account for both user and group quotas.
 */
void
xfs_trans_mod_dquot_byino(
    xfs_trans_t *tp,
    xfs_inode_t *ip,
    uint        field,
    long        delta)
{
    xfs_mount_t *mp = tp->t_mountp;

    if (!XFS_IS_QUOTA_RUNNING(mp) ||
        !XFS_IS_QUOTA_ON(mp) ||
        ip->i_ino == mp->m_sb.sb_uquotino ||
        ip->i_ino == mp->m_sb.sb_gquotino)
        return;

    if (tp->t_dqinfo == NULL)
        xfs_trans_alloc_dqinfo(tp);

    if (XFS_IS_UQUOTA_ON(mp) && ip->i_udquot)
        (void) xfs_trans_mod_dquot(tp, ip->i_udquot, field, delta);
    if (XFS_IS_OQUOTA_ON(mp) && ip->i_gdquot)
        (void) xfs_trans_mod_dquot(tp, ip->i_gdquot, field, delta);
}

STATIC xfs_dqtrx_t *
xfs_trans_get_dqtrx(
    xfs_trans_t *tp,
    xfs_dquot_t *dqp)
{
    int     i;
    xfs_dqtrx_t *qa;

    qa = XFS_QM_ISUDQ(dqp) ?
        tp->t_dqinfo->dqa_usrdquots : tp->t_dqinfo->dqa_grpdquots;

    for (i = 0; i < XFS_QM_TRANS_MAXDQS; i++) {
        if (qa[i].qt_dquot == NULL ||
            qa[i].qt_dquot == dqp)
            return &qa[i];
    }

    return NULL;
}

/*
 * Make the changes in the transaction structure.
 * The moral equivalent to xfs_trans_mod_sb().
 * We don't touch any fields in the dquot, so we don't care
 * if it's locked or not (most of the time it won't be).
 */
void
xfs_trans_mod_dquot(
    xfs_trans_t *tp,
    xfs_dquot_t *dqp,
    uint        field,
    long        delta)
{
    xfs_dqtrx_t *qtrx;

    ASSERT(tp);
    ASSERT(XFS_IS_QUOTA_RUNNING(tp->t_mountp));
    qtrx = NULL;

    if (tp->t_dqinfo == NULL)
        xfs_trans_alloc_dqinfo(tp);
    /*
     * Find either the first free slot or the slot that belongs
     * to this dquot.
     */
    qtrx = xfs_trans_get_dqtrx(tp, dqp);
    ASSERT(qtrx);
    if (qtrx->qt_dquot == NULL)
        qtrx->qt_dquot = dqp;

    switch (field) {

        /*
         * regular disk blk reservation
         */
          case XFS_TRANS_DQ_RES_BLKS:
        qtrx->qt_blk_res += (ulong)delta;
        break;

        /*
         * inode reservation
         */
          case XFS_TRANS_DQ_RES_INOS:
        qtrx->qt_ino_res += (ulong)delta;
        break;

        /*
         * disk blocks used.
         */
          case XFS_TRANS_DQ_BCOUNT:
        if (qtrx->qt_blk_res && delta > 0) {
            qtrx->qt_blk_res_used += (ulong)delta;
            ASSERT(qtrx->qt_blk_res >= qtrx->qt_blk_res_used);
        }
        qtrx->qt_bcount_delta += delta;
        break;

          case XFS_TRANS_DQ_DELBCOUNT:
        qtrx->qt_delbcnt_delta += delta;
        break;

        /*
         * Inode Count
         */
          case XFS_TRANS_DQ_ICOUNT:
        if (qtrx->qt_ino_res && delta > 0) {
            qtrx->qt_ino_res_used += (ulong)delta;
            ASSERT(qtrx->qt_ino_res >= qtrx->qt_ino_res_used);
        }
        qtrx->qt_icount_delta += delta;
        break;

        /*
         * rtblk reservation
         */
          case XFS_TRANS_DQ_RES_RTBLKS:
        qtrx->qt_rtblk_res += (ulong)delta;
        break;

        /*
         * rtblk count
         */
          case XFS_TRANS_DQ_RTBCOUNT:
        if (qtrx->qt_rtblk_res && delta > 0) {
            qtrx->qt_rtblk_res_used += (ulong)delta;
            ASSERT(qtrx->qt_rtblk_res >= qtrx->qt_rtblk_res_used);
        }
        qtrx->qt_rtbcount_delta += delta;
        break;

          case XFS_TRANS_DQ_DELRTBCOUNT:
        qtrx->qt_delrtb_delta += delta;
        break;

          default:
        ASSERT(0);
    }
    tp->t_flags |= XFS_TRANS_DQ_DIRTY;
}


/*
 * Given an array of dqtrx structures, lock all the dquots associated
 * and join them to the transaction, provided they have been modified.
 * We know that the highest number of dquots (of one type - usr OR grp),
 * involved in a transaction is 2 and that both usr and grp combined - 3.
 * So, we don't attempt to make this very generic.
 */
STATIC void
xfs_trans_dqlockedjoin(
    xfs_trans_t *tp,
    xfs_dqtrx_t *q)
{
    ASSERT(q[0].qt_dquot != NULL);
    if (q[1].qt_dquot == NULL) {
        xfs_dqlock(q[0].qt_dquot);
        xfs_trans_dqjoin(tp, q[0].qt_dquot);
    } else {
        ASSERT(XFS_QM_TRANS_MAXDQS == 2);
        xfs_dqlock2(q[0].qt_dquot, q[1].qt_dquot);
        xfs_trans_dqjoin(tp, q[0].qt_dquot);
        xfs_trans_dqjoin(tp, q[1].qt_dquot);
    }
}


/*
 * Called by xfs_trans_commit() and similar in spirit to
 * xfs_trans_apply_sb_deltas().
 * Go thru all the dquots belonging to this transaction and modify the
 * INCORE dquot to reflect the actual usages.
 * Unreserve just the reservations done by this transaction.
 * dquot is still left locked at exit.
 */
void
xfs_trans_apply_dquot_deltas(
    xfs_trans_t     *tp)
{
    int         i, j;
    xfs_dquot_t     *dqp;
    xfs_dqtrx_t     *qtrx, *qa;
    xfs_disk_dquot_t    *d;
    long            totalbdelta;
    long            totalrtbdelta;

    if (!(tp->t_flags & XFS_TRANS_DQ_DIRTY))
        return;

    ASSERT(tp->t_dqinfo);
    qa = tp->t_dqinfo->dqa_usrdquots;
    for (j = 0; j < 2; j++) {
        if (qa[0].qt_dquot == NULL) {
            qa = tp->t_dqinfo->dqa_grpdquots;
            continue;
        }

        /*
         * Lock all of the dquots and join them to the transaction.
         */
        xfs_trans_dqlockedjoin(tp, qa);

        for (i = 0; i < XFS_QM_TRANS_MAXDQS; i++) {
            qtrx = &qa[i];
            /*
             * The array of dquots is filled
             * sequentially, not sparsely.
             */
            if ((dqp = qtrx->qt_dquot) == NULL)
                break;

            ASSERT(XFS_DQ_IS_LOCKED(dqp));
            ASSERT(dqp->q_transp == tp);

            /*
             * adjust the actual number of blocks used
             */
            d = &dqp->q_core;

            /*
             * The issue here is - sometimes we don't make a blkquota
             * reservation intentionally to be fair to users
             * (when the amount is small). On the other hand,
             * delayed allocs do make reservations, but that's
             * outside of a transaction, so we have no
             * idea how much was really reserved.
             * So, here we've accumulated delayed allocation blks and
             * non-delay blks. The assumption is that the
             * delayed ones are always reserved (outside of a
             * transaction), and the others may or may not have
             * quota reservations.
             */
            totalbdelta = qtrx->qt_bcount_delta +
                qtrx->qt_delbcnt_delta;
            totalrtbdelta = qtrx->qt_rtbcount_delta +
                qtrx->qt_delrtb_delta;
#ifdef DEBUG
            if (totalbdelta < 0)
                ASSERT(be64_to_cpu(d->d_bcount) >=
                       -totalbdelta);

            if (totalrtbdelta < 0)
                ASSERT(be64_to_cpu(d->d_rtbcount) >=
                       -totalrtbdelta);

            if (qtrx->qt_icount_delta < 0)
                ASSERT(be64_to_cpu(d->d_icount) >=
                       -qtrx->qt_icount_delta);
#endif
            if (totalbdelta)
                be64_add_cpu(&d->d_bcount, (xfs_qcnt_t)totalbdelta);

            if (qtrx->qt_icount_delta)
                be64_add_cpu(&d->d_icount, (xfs_qcnt_t)qtrx->qt_icount_delta);

            if (totalrtbdelta)
                be64_add_cpu(&d->d_rtbcount, (xfs_qcnt_t)totalrtbdelta);

            /*
             * Get any default limits in use.
             * Start/reset the timer(s) if needed.
             */
            if (d->d_id) {
                xfs_qm_adjust_dqlimits(tp->t_mountp, d);
                xfs_qm_adjust_dqtimers(tp->t_mountp, d);
            }

            dqp->dq_flags |= XFS_DQ_DIRTY;
            /*
             * add this to the list of items to get logged
             */
            xfs_trans_log_dquot(tp, dqp);
            /*
             * Take off what's left of the original reservation.
             * In case of delayed allocations, there's no
             * reservation that a transaction structure knows of.
             */
            if (qtrx->qt_blk_res != 0) {
                if (qtrx->qt_blk_res != qtrx->qt_blk_res_used) {
                    if (qtrx->qt_blk_res >
                        qtrx->qt_blk_res_used)
                        dqp->q_res_bcount -= (xfs_qcnt_t)
                            (qtrx->qt_blk_res -
                             qtrx->qt_blk_res_used);
                    else
                        dqp->q_res_bcount -= (xfs_qcnt_t)
                            (qtrx->qt_blk_res_used -
                             qtrx->qt_blk_res);
                }
            } else {
                /*
                 * These blks were never reserved, either inside
                 * a transaction or outside one (in a delayed
                 * allocation). Also, this isn't always a
                 * negative number since we sometimes
                 * deliberately skip quota reservations.
                 */
                if (qtrx->qt_bcount_delta) {
                    dqp->q_res_bcount +=
                          (xfs_qcnt_t)qtrx->qt_bcount_delta;
                }
            }
            /*
             * Adjust the RT reservation.
             */
            if (qtrx->qt_rtblk_res != 0) {
                if (qtrx->qt_rtblk_res != qtrx->qt_rtblk_res_used) {
                    if (qtrx->qt_rtblk_res >
                        qtrx->qt_rtblk_res_used)
                           dqp->q_res_rtbcount -= (xfs_qcnt_t)
                               (qtrx->qt_rtblk_res -
                            qtrx->qt_rtblk_res_used);
                    else
                           dqp->q_res_rtbcount -= (xfs_qcnt_t)
                               (qtrx->qt_rtblk_res_used -
                            qtrx->qt_rtblk_res);
                }
            } else {
                if (qtrx->qt_rtbcount_delta)
                    dqp->q_res_rtbcount +=
                        (xfs_qcnt_t)qtrx->qt_rtbcount_delta;
            }

            /*
             * Adjust the inode reservation.
             */
            if (qtrx->qt_ino_res != 0) {
                ASSERT(qtrx->qt_ino_res >=
                       qtrx->qt_ino_res_used);
                if (qtrx->qt_ino_res > qtrx->qt_ino_res_used)
                    dqp->q_res_icount -= (xfs_qcnt_t)
                        (qtrx->qt_ino_res -
                         qtrx->qt_ino_res_used);
            } else {
                if (qtrx->qt_icount_delta)
                    dqp->q_res_icount +=
                        (xfs_qcnt_t)qtrx->qt_icount_delta;
            }

            ASSERT(dqp->q_res_bcount >=
                be64_to_cpu(dqp->q_core.d_bcount));
            ASSERT(dqp->q_res_icount >=
                be64_to_cpu(dqp->q_core.d_icount));
            ASSERT(dqp->q_res_rtbcount >=
                be64_to_cpu(dqp->q_core.d_rtbcount));
        }
        /*
         * Do the group quotas next
         */
        qa = tp->t_dqinfo->dqa_grpdquots;
    }
}

/*
 * Release the reservations, and adjust the dquots accordingly.
 * This is called only when the transaction is being aborted. If by
 * any chance we have done dquot modifications incore (ie. deltas) already,
 * we simply throw those away, since that's the expected behavior
 * when a transaction is curtailed without a commit.
 */
void
xfs_trans_unreserve_and_mod_dquots(
    xfs_trans_t     *tp)
{
    int         i, j;
    xfs_dquot_t     *dqp;
    xfs_dqtrx_t     *qtrx, *qa;
    boolean_t       locked;

    if (!tp->t_dqinfo || !(tp->t_flags & XFS_TRANS_DQ_DIRTY))
        return;

    qa = tp->t_dqinfo->dqa_usrdquots;

    for (j = 0; j < 2; j++) {
        for (i = 0; i < XFS_QM_TRANS_MAXDQS; i++) {
            qtrx = &qa[i];
            /*
             * We assume that the array of dquots is filled
             * sequentially, not sparsely.
             */
            if ((dqp = qtrx->qt_dquot) == NULL)
                break;
            /*
             * Unreserve the original reservation. We don't care
             * about the number of blocks used field, or deltas.
             * Also we don't bother to zero the fields.
             */
            locked = B_FALSE;
            if (qtrx->qt_blk_res) {
                xfs_dqlock(dqp);
                locked = B_TRUE;
                dqp->q_res_bcount -=
                    (xfs_qcnt_t)qtrx->qt_blk_res;
            }
            if (qtrx->qt_ino_res) {
                if (!locked) {
                    xfs_dqlock(dqp);
                    locked = B_TRUE;
                }
                dqp->q_res_icount -=
                    (xfs_qcnt_t)qtrx->qt_ino_res;
            }

            if (qtrx->qt_rtblk_res) {
                if (!locked) {
                    xfs_dqlock(dqp);
                    locked = B_TRUE;
                }
                dqp->q_res_rtbcount -=
                    (xfs_qcnt_t)qtrx->qt_rtblk_res;
            }
            if (locked)
                xfs_dqunlock(dqp);

        }
        qa = tp->t_dqinfo->dqa_grpdquots;
    }
}

STATIC void
xfs_quota_warn(
    struct xfs_mount    *mp,
    struct xfs_dquot    *dqp,
    int         type)
{
    /* no warnings for project quotas - we just return ENOSPC later */
    if (dqp->dq_flags & XFS_DQ_PROJ)
        return;
    quota_send_warning(make_kqid(&init_user_ns,
                     (dqp->dq_flags & XFS_DQ_USER) ?
                     USRQUOTA : GRPQUOTA,
                     be32_to_cpu(dqp->q_core.d_id)),
               mp->m_super->s_dev, type);
}

/*
 * This reserves disk blocks and inodes against a dquot.
 * Flags indicate if the dquot is to be locked here and also
 * if the blk reservation is for RT or regular blocks.
 * Sending in XFS_QMOPT_FORCE_RES flag skips the quota check.
 */
STATIC int
xfs_trans_dqresv(
    xfs_trans_t *tp,
    xfs_mount_t *mp,
    xfs_dquot_t *dqp,
    long        nblks,
    long        ninos,
    uint        flags)
{
    xfs_qcnt_t  hardlimit;
    xfs_qcnt_t  softlimit;
    time_t      timer;
    xfs_qwarncnt_t  warns;
    xfs_qwarncnt_t  warnlimit;
    xfs_qcnt_t  total_count;
    xfs_qcnt_t  *resbcountp;
    xfs_quotainfo_t *q = mp->m_quotainfo;


    xfs_dqlock(dqp);

    if (flags & XFS_TRANS_DQ_RES_BLKS) {
        hardlimit = be64_to_cpu(dqp->q_core.d_blk_hardlimit);
        if (!hardlimit)
            hardlimit = q->qi_bhardlimit;
        softlimit = be64_to_cpu(dqp->q_core.d_blk_softlimit);
        if (!softlimit)
            softlimit = q->qi_bsoftlimit;
        timer = be32_to_cpu(dqp->q_core.d_btimer);
        warns = be16_to_cpu(dqp->q_core.d_bwarns);
        warnlimit = dqp->q_mount->m_quotainfo->qi_bwarnlimit;
        resbcountp = &dqp->q_res_bcount;
    } else {
        ASSERT(flags & XFS_TRANS_DQ_RES_RTBLKS);
        hardlimit = be64_to_cpu(dqp->q_core.d_rtb_hardlimit);
        if (!hardlimit)
            hardlimit = q->qi_rtbhardlimit;
        softlimit = be64_to_cpu(dqp->q_core.d_rtb_softlimit);
        if (!softlimit)
            softlimit = q->qi_rtbsoftlimit;
        timer = be32_to_cpu(dqp->q_core.d_rtbtimer);
        warns = be16_to_cpu(dqp->q_core.d_rtbwarns);
        warnlimit = dqp->q_mount->m_quotainfo->qi_rtbwarnlimit;
        resbcountp = &dqp->q_res_rtbcount;
    }

    if ((flags & XFS_QMOPT_FORCE_RES) == 0 &&
        dqp->q_core.d_id &&
        ((XFS_IS_UQUOTA_ENFORCED(dqp->q_mount) && XFS_QM_ISUDQ(dqp)) ||
         (XFS_IS_OQUOTA_ENFORCED(dqp->q_mount) &&
          (XFS_QM_ISPDQ(dqp) || XFS_QM_ISGDQ(dqp))))) {
        if (nblks > 0) {
            /*
             * dquot is locked already. See if we'd go over the
             * hardlimit or exceed the timelimit if we allocate
             * nblks.
             */
            total_count = *resbcountp + nblks;
            if (hardlimit && total_count > hardlimit) {
                xfs_quota_warn(mp, dqp, QUOTA_NL_BHARDWARN);
                goto error_return;
            }
            if (softlimit && total_count > softlimit) {
                if ((timer != 0 && get_seconds() > timer) ||
                    (warns != 0 && warns >= warnlimit)) {
                    xfs_quota_warn(mp, dqp,
                               QUOTA_NL_BSOFTLONGWARN);
                    goto error_return;
                }

                xfs_quota_warn(mp, dqp, QUOTA_NL_BSOFTWARN);
            }
        }
        if (ninos > 0) {
            total_count = be64_to_cpu(dqp->q_core.d_icount) + ninos;
            timer = be32_to_cpu(dqp->q_core.d_itimer);
            warns = be16_to_cpu(dqp->q_core.d_iwarns);
            warnlimit = dqp->q_mount->m_quotainfo->qi_iwarnlimit;
            hardlimit = be64_to_cpu(dqp->q_core.d_ino_hardlimit);
            if (!hardlimit)
                hardlimit = q->qi_ihardlimit;
            softlimit = be64_to_cpu(dqp->q_core.d_ino_softlimit);
            if (!softlimit)
                softlimit = q->qi_isoftlimit;

            if (hardlimit && total_count > hardlimit) {
                xfs_quota_warn(mp, dqp, QUOTA_NL_IHARDWARN);
                goto error_return;
            }
            if (softlimit && total_count > softlimit) {
                if  ((timer != 0 && get_seconds() > timer) ||
                     (warns != 0 && warns >= warnlimit)) {
                    xfs_quota_warn(mp, dqp,
                               QUOTA_NL_ISOFTLONGWARN);
                    goto error_return;
                }
                xfs_quota_warn(mp, dqp, QUOTA_NL_ISOFTWARN);
            }
        }
    }

    /*
     * Change the reservation, but not the actual usage.
     * Note that q_res_bcount = q_core.d_bcount + resv
     */
    (*resbcountp) += (xfs_qcnt_t)nblks;
    if (ninos != 0)
        dqp->q_res_icount += (xfs_qcnt_t)ninos;

    /*
     * note the reservation amt in the trans struct too,
     * so that the transaction knows how much was reserved by
     * it against this particular dquot.
     * We don't do this when we are reserving for a delayed allocation,
     * because we don't have the luxury of a transaction envelope then.
     */
    if (tp) {
        ASSERT(tp->t_dqinfo);
        ASSERT(flags & XFS_QMOPT_RESBLK_MASK);
        if (nblks != 0)
            xfs_trans_mod_dquot(tp, dqp,
                        flags & XFS_QMOPT_RESBLK_MASK,
                        nblks);
        if (ninos != 0)
            xfs_trans_mod_dquot(tp, dqp,
                        XFS_TRANS_DQ_RES_INOS,
                        ninos);
    }
    ASSERT(dqp->q_res_bcount >= be64_to_cpu(dqp->q_core.d_bcount));
    ASSERT(dqp->q_res_rtbcount >= be64_to_cpu(dqp->q_core.d_rtbcount));
    ASSERT(dqp->q_res_icount >= be64_to_cpu(dqp->q_core.d_icount));

    xfs_dqunlock(dqp);
    return 0;

error_return:
    xfs_dqunlock(dqp);
    if (flags & XFS_QMOPT_ENOSPC)
        return ENOSPC;
    return EDQUOT;
}


/*
 * Given dquot(s), make disk block and/or inode reservations against them.
 * The fact that this does the reservation against both the usr and
 * grp/prj quotas is important, because this follows a both-or-nothing
 * approach.
 *
 * flags = XFS_QMOPT_FORCE_RES evades limit enforcement. Used by chown.
 *     XFS_QMOPT_ENOSPC returns ENOSPC not EDQUOT.  Used by pquota.
 *     XFS_TRANS_DQ_RES_BLKS reserves regular disk blocks
 *     XFS_TRANS_DQ_RES_RTBLKS reserves realtime disk blocks
 * dquots are unlocked on return, if they were not locked by caller.
 */
int
xfs_trans_reserve_quota_bydquots(
    xfs_trans_t *tp,
    xfs_mount_t *mp,
    xfs_dquot_t *udqp,
    xfs_dquot_t *gdqp,
    long        nblks,
    long        ninos,
    uint        flags)
{
    int     resvd = 0, error;

    if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
        return 0;

    if (tp && tp->t_dqinfo == NULL)
        xfs_trans_alloc_dqinfo(tp);

    ASSERT(flags & XFS_QMOPT_RESBLK_MASK);

    if (udqp) {
        error = xfs_trans_dqresv(tp, mp, udqp, nblks, ninos,
                    (flags & ~XFS_QMOPT_ENOSPC));
        if (error)
            return error;
        resvd = 1;
    }

    if (gdqp) {
        error = xfs_trans_dqresv(tp, mp, gdqp, nblks, ninos, flags);
        if (error) {
            /*
             * can't do it, so backout previous reservation
             */
            if (resvd) {
                flags |= XFS_QMOPT_FORCE_RES;
                xfs_trans_dqresv(tp, mp, udqp,
                         -nblks, -ninos, flags);
            }
            return error;
        }
    }

    /*
     * Didn't change anything critical, so, no need to log
     */
    return 0;
}


/*
 * Lock the dquot and change the reservation if we can.
 * This doesn't change the actual usage, just the reservation.
 * The inode sent in is locked.
 */
int
xfs_trans_reserve_quota_nblks(
    struct xfs_trans    *tp,
    struct xfs_inode    *ip,
    long            nblks,
    long            ninos,
    uint            flags)
{
    struct xfs_mount    *mp = ip->i_mount;

    if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
        return 0;
    if (XFS_IS_PQUOTA_ON(mp))
        flags |= XFS_QMOPT_ENOSPC;

    ASSERT(ip->i_ino != mp->m_sb.sb_uquotino);
    ASSERT(ip->i_ino != mp->m_sb.sb_gquotino);

    ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
    ASSERT((flags & ~(XFS_QMOPT_FORCE_RES | XFS_QMOPT_ENOSPC)) ==
                XFS_TRANS_DQ_RES_RTBLKS ||
           (flags & ~(XFS_QMOPT_FORCE_RES | XFS_QMOPT_ENOSPC)) ==
                XFS_TRANS_DQ_RES_BLKS);

    /*
     * Reserve nblks against these dquots, with trans as the mediator.
     */
    return xfs_trans_reserve_quota_bydquots(tp, mp,
                        ip->i_udquot, ip->i_gdquot,
                        nblks, ninos, flags);
}

/*
 * This routine is called to allocate a quotaoff log item.
 */
xfs_qoff_logitem_t *
xfs_trans_get_qoff_item(
    xfs_trans_t     *tp,
    xfs_qoff_logitem_t  *startqoff,
    uint            flags)
{
    xfs_qoff_logitem_t  *q;

    ASSERT(tp != NULL);

    q = xfs_qm_qoff_logitem_init(tp->t_mountp, startqoff, flags);
    ASSERT(q != NULL);

    /*
     * Get a log_item_desc to point at the new item.
     */
    xfs_trans_add_item(tp, &q->qql_item);
    return q;
}


/*
 * This is called to mark the quotaoff logitem as needing
 * to be logged when the transaction is committed.  The logitem must
 * already be associated with the given transaction.
 */
void
xfs_trans_log_quotaoff_item(
    xfs_trans_t     *tp,
    xfs_qoff_logitem_t  *qlp)
{
    tp->t_flags |= XFS_TRANS_DIRTY;
    qlp->qql_item.li_desc->lid_flags |= XFS_LID_DIRTY;
}

STATIC void
xfs_trans_alloc_dqinfo(
    xfs_trans_t *tp)
{
    tp->t_dqinfo = kmem_zone_zalloc(xfs_qm_dqtrxzone, KM_SLEEP);
}

void
xfs_trans_free_dqinfo(
    xfs_trans_t *tp)
{
    if (!tp->t_dqinfo)
        return;
    kmem_zone_free(xfs_qm_dqtrxzone, tp->t_dqinfo);
    tp->t_dqinfo = NULL;
}