// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2002 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs_platform.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_quota.h"
#include "xfs_qm.h"
#include "xfs_trace.h"
#include "xfs_error.h"
#include "xfs_health.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(
        struct xfs_trans        *tp,
        struct xfs_dquot        *dqp)
{
        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);
}

/*
 * 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(
        struct xfs_trans        *tp,
        struct xfs_dquot        *dqp)
{
        ASSERT(XFS_DQ_IS_LOCKED(dqp));

        /* Upgrade the dquot to bigtime format if possible. */
        if (dqp->q_id != 0 &&
            xfs_has_bigtime(tp->t_mountp) &&
            !(dqp->q_type & XFS_DQTYPE_BIGTIME))
                dqp->q_type |= XFS_DQTYPE_BIGTIME;

        tp->t_flags |= XFS_TRANS_DIRTY;
        set_bit(XFS_LI_DIRTY, &dqp->q_logitem.qli_item.li_flags);
}

/*
 * Carry forward whatever is left of the quota blk reservation to
 * the spanky new transaction
 */
void
xfs_trans_dup_dqinfo(
        struct xfs_trans        *otp,
        struct xfs_trans        *ntp)
{
        struct xfs_dqtrx        *oq, *nq;
        int                     i, j;
        struct xfs_dqtrx        *oqa, *nqa;
        uint64_t                blk_res_used;

        if (!otp->t_dqinfo)
                return;

        xfs_trans_alloc_dqinfo(ntp);

        for (j = 0; j < XFS_QM_TRANS_DQTYPES; j++) {
                oqa = otp->t_dqinfo->dqs[j];
                nqa = ntp->t_dqinfo->dqs[j];
                for (i = 0; i < XFS_QM_TRANS_MAXDQS; i++) {
                        blk_res_used = 0;

                        if (oqa[i].qt_dquot == NULL)
                                break;
                        oq = &oqa[i];
                        nq = &nqa[i];

                        if (oq->qt_blk_res && oq->qt_bcount_delta > 0)
                                blk_res_used = oq->qt_bcount_delta;

                        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 - blk_res_used;
                        oq->qt_blk_res = 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;

                }
        }
}

#ifdef CONFIG_XFS_LIVE_HOOKS
/*
 * Use a static key here to reduce the overhead of quota live updates.  If the
 * compiler supports jump labels, the static branch will be replaced by a nop
 * sled when there are no hook users.  Online fsck is currently the only
 * caller, so this is a reasonable tradeoff.
 *
 * Note: Patching the kernel code requires taking the cpu hotplug lock.  Other
 * parts of the kernel allocate memory with that lock held, which means that
 * XFS callers cannot hold any locks that might be used by memory reclaim or
 * writeback when calling the static_branch_{inc,dec} functions.
 */
DEFINE_STATIC_XFS_HOOK_SWITCH(xfs_dqtrx_hooks_switch);

void
xfs_dqtrx_hook_disable(void)
{
        xfs_hooks_switch_off(&xfs_dqtrx_hooks_switch);
}

void
xfs_dqtrx_hook_enable(void)
{
        xfs_hooks_switch_on(&xfs_dqtrx_hooks_switch);
}

/* Schedule a transactional dquot update on behalf of an inode. */
void
xfs_trans_mod_ino_dquot(
        struct xfs_trans                *tp,
        struct xfs_inode                *ip,
        struct xfs_dquot                *dqp,
        unsigned int                    field,
        int64_t                         delta)
{
        if (xfs_is_metadir_inode(ip))
                return;

        xfs_trans_mod_dquot(tp, dqp, field, delta);

        if (xfs_hooks_switched_on(&xfs_dqtrx_hooks_switch)) {
                struct xfs_mod_ino_dqtrx_params p = {
                        .tx_id          = (uintptr_t)tp,
                        .ino            = ip->i_ino,
                        .q_type         = xfs_dquot_type(dqp),
                        .q_id           = dqp->q_id,
                        .delta          = delta
                };
                struct xfs_quotainfo    *qi = tp->t_mountp->m_quotainfo;

                xfs_hooks_call(&qi->qi_mod_ino_dqtrx_hooks, field, &p);
        }
}

/* Call the specified functions during a dquot counter update. */
int
xfs_dqtrx_hook_add(
        struct xfs_quotainfo    *qi,
        struct xfs_dqtrx_hook   *hook)
{
        int                     error;

        /*
         * Transactional dquot updates first call the mod hook when changes
         * are attached to the transaction and then call the apply hook when
         * those changes are committed (or canceled).
         *
         * The apply hook must be installed before the mod hook so that we
         * never fail to catch the end of a quota update sequence.
         */
        error = xfs_hooks_add(&qi->qi_apply_dqtrx_hooks, &hook->apply_hook);
        if (error)
                goto out;

        error = xfs_hooks_add(&qi->qi_mod_ino_dqtrx_hooks, &hook->mod_hook);
        if (error)
                goto out_apply;

        return 0;

out_apply:
        xfs_hooks_del(&qi->qi_apply_dqtrx_hooks, &hook->apply_hook);
out:
        return error;
}

/* Stop calling the specified function during a dquot counter update. */
void
xfs_dqtrx_hook_del(
        struct xfs_quotainfo    *qi,
        struct xfs_dqtrx_hook   *hook)
{
        /*
         * The mod hook must be removed before apply hook to avoid giving the
         * hook consumer with an incomplete update.  No hooks should be running
         * after these functions return.
         */
        xfs_hooks_del(&qi->qi_mod_ino_dqtrx_hooks, &hook->mod_hook);
        xfs_hooks_del(&qi->qi_apply_dqtrx_hooks, &hook->apply_hook);
}

/* Configure dquot update hook functions. */
void
xfs_dqtrx_hook_setup(
        struct xfs_dqtrx_hook   *hook,
        notifier_fn_t           mod_fn,
        notifier_fn_t           apply_fn)
{
        xfs_hook_setup(&hook->mod_hook, mod_fn);
        xfs_hook_setup(&hook->apply_hook, apply_fn);
}
#endif /* CONFIG_XFS_LIVE_HOOKS */

/*
 * 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,
        int64_t         delta)
{
        xfs_mount_t     *mp = tp->t_mountp;

        if (!XFS_IS_QUOTA_ON(mp) ||
            xfs_is_quota_inode(&mp->m_sb, ip->i_ino) ||
            xfs_is_metadir_inode(ip))
                return;

        if (XFS_IS_UQUOTA_ON(mp) && ip->i_udquot)
                xfs_trans_mod_ino_dquot(tp, ip, ip->i_udquot, field, delta);
        if (XFS_IS_GQUOTA_ON(mp) && ip->i_gdquot)
                xfs_trans_mod_ino_dquot(tp, ip, ip->i_gdquot, field, delta);
        if (XFS_IS_PQUOTA_ON(mp) && ip->i_pdquot)
                xfs_trans_mod_ino_dquot(tp, ip, ip->i_pdquot, field, delta);
}

STATIC struct xfs_dqtrx *
xfs_trans_get_dqtrx(
        struct xfs_trans        *tp,
        struct xfs_dquot        *dqp)
{
        int                     i;
        struct xfs_dqtrx        *qa;

        switch (xfs_dquot_type(dqp)) {
        case XFS_DQTYPE_USER:
                qa = tp->t_dqinfo->dqs[XFS_QM_TRANS_USR];
                break;
        case XFS_DQTYPE_GROUP:
                qa = tp->t_dqinfo->dqs[XFS_QM_TRANS_GRP];
                break;
        case XFS_DQTYPE_PROJ:
                qa = tp->t_dqinfo->dqs[XFS_QM_TRANS_PRJ];
                break;
        default:
                return NULL;
        }

        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(
        struct xfs_trans        *tp,
        struct xfs_dquot        *dqp,
        uint                    field,
        int64_t                 delta)
{
        struct xfs_dqtrx        *qtrx;

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

        if (!delta)
                return;

        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;

        trace_xfs_trans_mod_dquot_before(qtrx);
        trace_xfs_trans_mod_dquot(tp, dqp, field, delta);

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

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

        /* disk blocks used. */
        case XFS_TRANS_DQ_BCOUNT:
                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 += 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 += delta;
                break;

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

        trace_xfs_trans_mod_dquot_after(qtrx);
}


/*
 * Given an array of dqtrx structures, lock all the dquots associated and join
 * them to the transaction, provided they have been modified.
 */
STATIC void
xfs_trans_dqlockedjoin(
        struct xfs_trans        *tp,
        struct xfs_dqtrx        *q)
{
        unsigned int            i;
        ASSERT(q[0].qt_dquot != NULL);
        if (q[1].qt_dquot == NULL) {
                mutex_lock(&q[0].qt_dquot->q_qlock);
                xfs_trans_dqjoin(tp, q[0].qt_dquot);
        } else if (q[2].qt_dquot == NULL) {
                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);
        } else {
                xfs_dqlockn(q);
                for (i = 0; i < XFS_QM_TRANS_MAXDQS; i++) {
                        if (q[i].qt_dquot == NULL)
                                break;
                        xfs_trans_dqjoin(tp, q[i].qt_dquot);
                }
        }
}

/* Apply dqtrx changes to the quota reservation counters. */
static inline void
xfs_apply_quota_reservation_deltas(
        struct xfs_dquot_res    *res,
        uint64_t                reserved,
        int64_t                 res_used,
        int64_t                 count_delta)
{
        if (reserved != 0) {
                /*
                 * Subtle math here: If reserved > res_used (the normal case),
                 * we're simply subtracting the unused transaction quota
                 * reservation from the dquot reservation.
                 *
                 * If, however, res_used > reserved, then we have allocated
                 * more quota blocks than were reserved for the transaction.
                 * We must add that excess to the dquot reservation since it
                 * tracks (usage + resv) and by definition we didn't reserve
                 * that excess.
                 */
                res->reserved -= abs(reserved - res_used);
        } else if (count_delta != 0) {
                /*
                 * 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.
                 */
                res->reserved += count_delta;
        }
}

#ifdef CONFIG_XFS_LIVE_HOOKS
/* Call downstream hooks now that it's time to apply dquot deltas. */
static inline void
xfs_trans_apply_dquot_deltas_hook(
        struct xfs_trans                *tp,
        struct xfs_dquot                *dqp)
{
        if (xfs_hooks_switched_on(&xfs_dqtrx_hooks_switch)) {
                struct xfs_apply_dqtrx_params   p = {
                        .tx_id          = (uintptr_t)tp,
                        .q_type         = xfs_dquot_type(dqp),
                        .q_id           = dqp->q_id,
                };
                struct xfs_quotainfo    *qi = tp->t_mountp->m_quotainfo;

                xfs_hooks_call(&qi->qi_apply_dqtrx_hooks,
                                XFS_APPLY_DQTRX_COMMIT, &p);
        }
}
#else
# define xfs_trans_apply_dquot_deltas_hook(tp, dqp)     ((void)0)
#endif /* CONFIG_XFS_LIVE_HOOKS */

/*
 * 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(
        struct xfs_trans        *tp)
{
        int                     i, j;
        struct xfs_dquot        *dqp;
        struct xfs_dqtrx        *qtrx, *qa;
        int64_t                 totalbdelta;
        int64_t                 totalrtbdelta;

        if (!tp->t_dqinfo)
                return;

        ASSERT(tp->t_dqinfo);
        for (j = 0; j < XFS_QM_TRANS_DQTYPES; j++) {
                qa = tp->t_dqinfo->dqs[j];
                if (qa[0].qt_dquot == NULL)
                        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++) {
                        uint64_t        blk_res_used;

                        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));

                        xfs_trans_apply_dquot_deltas_hook(tp, dqp);

                        /*
                         * adjust the actual number of blocks used
                         */

                        /*
                         * 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;

                        if (totalbdelta != 0 || totalrtbdelta != 0 ||
                            qtrx->qt_icount_delta != 0) {
                                trace_xfs_trans_apply_dquot_deltas_before(dqp);
                                trace_xfs_trans_apply_dquot_deltas(qtrx);
                        }

#ifdef DEBUG
                        if (totalbdelta < 0)
                                ASSERT(dqp->q_blk.count >= -totalbdelta);

                        if (totalrtbdelta < 0)
                                ASSERT(dqp->q_rtb.count >= -totalrtbdelta);

                        if (qtrx->qt_icount_delta < 0)
                                ASSERT(dqp->q_ino.count >= -qtrx->qt_icount_delta);
#endif
                        if (totalbdelta)
                                dqp->q_blk.count += totalbdelta;

                        if (qtrx->qt_icount_delta)
                                dqp->q_ino.count += qtrx->qt_icount_delta;

                        if (totalrtbdelta)
                                dqp->q_rtb.count += totalrtbdelta;

                        if (totalbdelta != 0 || totalrtbdelta != 0 ||
                            qtrx->qt_icount_delta != 0)
                                trace_xfs_trans_apply_dquot_deltas_after(dqp);

                        /*
                         * Get any default limits in use.
                         * Start/reset the timer(s) if needed.
                         */
                        if (dqp->q_id) {
                                xfs_qm_adjust_dqlimits(dqp);
                                xfs_qm_adjust_dqtimers(dqp);
                        }

                        dqp->q_flags |= XFS_DQFLAG_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.
                         */
                        blk_res_used = max_t(int64_t, 0, qtrx->qt_bcount_delta);
                        xfs_apply_quota_reservation_deltas(&dqp->q_blk,
                                        qtrx->qt_blk_res, blk_res_used,
                                        qtrx->qt_bcount_delta);

                        /*
                         * Adjust the RT reservation.
                         */
                        xfs_apply_quota_reservation_deltas(&dqp->q_rtb,
                                        qtrx->qt_rtblk_res,
                                        qtrx->qt_rtblk_res_used,
                                        qtrx->qt_rtbcount_delta);

                        /*
                         * Adjust the inode reservation.
                         */
                        ASSERT(qtrx->qt_ino_res >= qtrx->qt_ino_res_used);
                        xfs_apply_quota_reservation_deltas(&dqp->q_ino,
                                        qtrx->qt_ino_res,
                                        qtrx->qt_ino_res_used,
                                        qtrx->qt_icount_delta);

                        ASSERT(dqp->q_blk.reserved >= dqp->q_blk.count);
                        ASSERT(dqp->q_ino.reserved >= dqp->q_ino.count);
                        ASSERT(dqp->q_rtb.reserved >= dqp->q_rtb.count);

                        /*
                         * We've applied the count changes and given back
                         * whatever reservation we didn't use.  Zero out the
                         * dqtrx fields.
                         */
                        qtrx->qt_blk_res = 0;
                        qtrx->qt_bcount_delta = 0;
                        qtrx->qt_delbcnt_delta = 0;

                        qtrx->qt_rtblk_res = 0;
                        qtrx->qt_rtblk_res_used = 0;
                        qtrx->qt_rtbcount_delta = 0;
                        qtrx->qt_delrtb_delta = 0;

                        qtrx->qt_ino_res = 0;
                        qtrx->qt_ino_res_used = 0;
                        qtrx->qt_icount_delta = 0;
                }
        }
}

#ifdef CONFIG_XFS_LIVE_HOOKS
/* Call downstream hooks now that it's time to cancel dquot deltas. */
static inline void
xfs_trans_unreserve_and_mod_dquots_hook(
        struct xfs_trans                *tp,
        struct xfs_dquot                *dqp)
{
        if (xfs_hooks_switched_on(&xfs_dqtrx_hooks_switch)) {
                struct xfs_apply_dqtrx_params   p = {
                        .tx_id          = (uintptr_t)tp,
                        .q_type         = xfs_dquot_type(dqp),
                        .q_id           = dqp->q_id,
                };
                struct xfs_quotainfo    *qi = tp->t_mountp->m_quotainfo;

                xfs_hooks_call(&qi->qi_apply_dqtrx_hooks,
                                XFS_APPLY_DQTRX_UNRESERVE, &p);
        }
}
#else
# define xfs_trans_unreserve_and_mod_dquots_hook(tp, dqp)       ((void)0)
#endif /* CONFIG_XFS_LIVE_HOOKS */

/*
 * 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(
        struct xfs_trans        *tp,
        bool                    already_locked)
{
        int                     i, j;
        struct xfs_dquot        *dqp;
        struct xfs_dqtrx        *qtrx, *qa;
        bool                    locked;

        if (!tp->t_dqinfo)
                return;

        for (j = 0; j < XFS_QM_TRANS_DQTYPES; j++) {
                qa = tp->t_dqinfo->dqs[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;

                        xfs_trans_unreserve_and_mod_dquots_hook(tp, dqp);

                        /*
                         * 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 = already_locked;
                        if (qtrx->qt_blk_res) {
                                if (!locked) {
                                        mutex_lock(&dqp->q_qlock);
                                        locked = true;
                                }
                                dqp->q_blk.reserved -=
                                        (xfs_qcnt_t)qtrx->qt_blk_res;
                        }
                        if (qtrx->qt_ino_res) {
                                if (!locked) {
                                        mutex_lock(&dqp->q_qlock);
                                        locked = true;
                                }
                                dqp->q_ino.reserved -=
                                        (xfs_qcnt_t)qtrx->qt_ino_res;
                        }

                        if (qtrx->qt_rtblk_res) {
                                if (!locked) {
                                        mutex_lock(&dqp->q_qlock);
                                        locked = true;
                                }
                                dqp->q_rtb.reserved -=
                                        (xfs_qcnt_t)qtrx->qt_rtblk_res;
                        }
                        if (locked && !already_locked)
                                mutex_unlock(&dqp->q_qlock);

                }
        }
}

STATIC void
xfs_quota_warn(
        struct xfs_mount        *mp,
        struct xfs_dquot        *dqp,
        int                     type)
{
        enum quota_type         qtype;

        switch (xfs_dquot_type(dqp)) {
        case XFS_DQTYPE_PROJ:
                qtype = PRJQUOTA;
                break;
        case XFS_DQTYPE_USER:
                qtype = USRQUOTA;
                break;
        case XFS_DQTYPE_GROUP:
                qtype = GRPQUOTA;
                break;
        default:
                return;
        }

        quota_send_warning(make_kqid(&init_user_ns, qtype, dqp->q_id),
                           mp->m_super->s_dev, type);
}

/*
 * Decide if we can make an additional reservation against a quota resource.
 * Returns an inode QUOTA_NL_ warning code and whether or not it's fatal.
 *
 * Note that we assume that the numeric difference between the inode and block
 * warning codes will always be 3 since it's userspace ABI now, and will never
 * decrease the quota reservation, so the *BELOW messages are irrelevant.
 */
static inline int
xfs_dqresv_check(
        struct xfs_dquot_res    *res,
        struct xfs_quota_limits *qlim,
        int64_t                 delta,
        bool                    *fatal)
{
        xfs_qcnt_t              hardlimit = res->hardlimit;
        xfs_qcnt_t              softlimit = res->softlimit;
        xfs_qcnt_t              total_count = res->reserved + delta;

        BUILD_BUG_ON(QUOTA_NL_BHARDWARN     != QUOTA_NL_IHARDWARN + 3);
        BUILD_BUG_ON(QUOTA_NL_BSOFTLONGWARN != QUOTA_NL_ISOFTLONGWARN + 3);
        BUILD_BUG_ON(QUOTA_NL_BSOFTWARN     != QUOTA_NL_ISOFTWARN + 3);

        *fatal = false;
        if (delta <= 0)
                return QUOTA_NL_NOWARN;

        if (!hardlimit)
                hardlimit = qlim->hard;
        if (!softlimit)
                softlimit = qlim->soft;

        if (hardlimit && total_count > hardlimit) {
                *fatal = true;
                return QUOTA_NL_IHARDWARN;
        }

        if (softlimit && total_count > softlimit) {
                time64_t        now = ktime_get_real_seconds();

                if (res->timer != 0 && now > res->timer) {
                        *fatal = true;
                        return QUOTA_NL_ISOFTLONGWARN;
                }

                return QUOTA_NL_ISOFTWARN;
        }

        return QUOTA_NL_NOWARN;
}

/*
 * 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(
        struct xfs_trans        *tp,
        struct xfs_mount        *mp,
        struct xfs_dquot        *dqp,
        int64_t                 nblks,
        long                    ninos,
        uint                    flags)
{
        struct xfs_quotainfo    *q = mp->m_quotainfo;
        struct xfs_def_quota    *defq;
        struct xfs_dquot_res    *blkres;
        struct xfs_quota_limits *qlim;

        mutex_lock(&dqp->q_qlock);

        defq = xfs_get_defquota(q, xfs_dquot_type(dqp));

        if (flags & XFS_TRANS_DQ_RES_BLKS) {
                blkres = &dqp->q_blk;
                qlim = &defq->blk;
        } else {
                blkres = &dqp->q_rtb;
                qlim = &defq->rtb;
        }

        if ((flags & XFS_QMOPT_FORCE_RES) == 0 && dqp->q_id &&
            xfs_dquot_is_enforced(dqp)) {
                int             quota_nl;
                bool            fatal;

                /*
                 * dquot is locked already. See if we'd go over the hardlimit
                 * or exceed the timelimit if we'd reserve resources.
                 */
                quota_nl = xfs_dqresv_check(blkres, qlim, nblks, &fatal);
                if (quota_nl != QUOTA_NL_NOWARN) {
                        /*
                         * Quota block warning codes are 3 more than the inode
                         * codes, which we check above.
                         */
                        xfs_quota_warn(mp, dqp, quota_nl + 3);
                        if (fatal)
                                goto error_return;
                }

                quota_nl = xfs_dqresv_check(&dqp->q_ino, &defq->ino, ninos,
                                &fatal);
                if (quota_nl != QUOTA_NL_NOWARN) {
                        xfs_quota_warn(mp, dqp, quota_nl);
                        if (fatal)
                                goto error_return;
                }
        }

        /*
         * Change the reservation, but not the actual usage.
         * Note that q_blk.reserved = q_blk.count + resv
         */
        blkres->reserved += (xfs_qcnt_t)nblks;
        dqp->q_ino.reserved += (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(flags & XFS_QMOPT_RESBLK_MASK);
                xfs_trans_mod_dquot(tp, dqp, flags & XFS_QMOPT_RESBLK_MASK,
                                    nblks);
                xfs_trans_mod_dquot(tp, dqp, XFS_TRANS_DQ_RES_INOS, ninos);
        }

        if (XFS_IS_CORRUPT(mp, dqp->q_blk.reserved < dqp->q_blk.count) ||
            XFS_IS_CORRUPT(mp, dqp->q_rtb.reserved < dqp->q_rtb.count) ||
            XFS_IS_CORRUPT(mp, dqp->q_ino.reserved < dqp->q_ino.count))
                goto error_corrupt;

        mutex_unlock(&dqp->q_qlock);
        return 0;

error_return:
        mutex_unlock(&dqp->q_qlock);
        if (xfs_dquot_type(dqp) == XFS_DQTYPE_PROJ)
                return -ENOSPC;
        return -EDQUOT;
error_corrupt:
        mutex_unlock(&dqp->q_qlock);
        xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
        xfs_fs_mark_sick(mp, XFS_SICK_FS_QUOTACHECK);
        return -EFSCORRUPTED;
}


/*
 * Given dquot(s), make disk block and/or inode reservations against them.
 * The fact that this does the reservation against user, group and
 * project quotas is important, because this follows a all-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(
        struct xfs_trans        *tp,
        struct xfs_mount        *mp,
        struct xfs_dquot        *udqp,
        struct xfs_dquot        *gdqp,
        struct xfs_dquot        *pdqp,
        int64_t                 nblks,
        long                    ninos,
        uint                    flags)
{
        int             error;

        if (!XFS_IS_QUOTA_ON(mp))
                return 0;

        ASSERT(flags & XFS_QMOPT_RESBLK_MASK);

        if (udqp) {
                error = xfs_trans_dqresv(tp, mp, udqp, nblks, ninos, flags);
                if (error)
                        return error;
        }

        if (gdqp) {
                error = xfs_trans_dqresv(tp, mp, gdqp, nblks, ninos, flags);
                if (error)
                        goto unwind_usr;
        }

        if (pdqp) {
                error = xfs_trans_dqresv(tp, mp, pdqp, nblks, ninos, flags);
                if (error)
                        goto unwind_grp;
        }

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

unwind_grp:
        flags |= XFS_QMOPT_FORCE_RES;
        if (gdqp)
                xfs_trans_dqresv(tp, mp, gdqp, -nblks, -ninos, flags);
unwind_usr:
        flags |= XFS_QMOPT_FORCE_RES;
        if (udqp)
                xfs_trans_dqresv(tp, mp, udqp, -nblks, -ninos, flags);
        return error;
}


/*
 * 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,
        int64_t                 dblocks,
        int64_t                 rblocks,
        bool                    force)
{
        struct xfs_mount        *mp = ip->i_mount;
        unsigned int            qflags = 0;
        int                     error;

        if (!XFS_IS_QUOTA_ON(mp))
                return 0;
        if (xfs_is_metadir_inode(ip))
                return 0;

        ASSERT(!xfs_is_quota_inode(&mp->m_sb, ip->i_ino));
        xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);

        if (force)
                qflags |= XFS_QMOPT_FORCE_RES;

        /* Reserve data device quota against the inode's dquots. */
        error = xfs_trans_reserve_quota_bydquots(tp, mp, ip->i_udquot,
                        ip->i_gdquot, ip->i_pdquot, dblocks, 0,
                        XFS_QMOPT_RES_REGBLKS | qflags);
        if (error)
                return error;

        /* Do the same but for realtime blocks. */
        error = xfs_trans_reserve_quota_bydquots(tp, mp, ip->i_udquot,
                        ip->i_gdquot, ip->i_pdquot, rblocks, 0,
                        XFS_QMOPT_RES_RTBLKS | qflags);
        if (error) {
                xfs_trans_reserve_quota_bydquots(tp, mp, ip->i_udquot,
                                ip->i_gdquot, ip->i_pdquot, -dblocks, 0,
                                XFS_QMOPT_RES_REGBLKS);
                return error;
        }

        return 0;
}

/* Change the quota reservations for an inode creation activity. */
int
xfs_trans_reserve_quota_icreate(
        struct xfs_trans        *tp,
        struct xfs_dquot        *udqp,
        struct xfs_dquot        *gdqp,
        struct xfs_dquot        *pdqp,
        int64_t                 dblocks)
{
        struct xfs_mount        *mp = tp->t_mountp;

        if (!XFS_IS_QUOTA_ON(mp))
                return 0;

        return xfs_trans_reserve_quota_bydquots(tp, mp, udqp, gdqp, pdqp,
                        dblocks, 1, XFS_QMOPT_RES_REGBLKS);
}

STATIC void
xfs_trans_alloc_dqinfo(
        xfs_trans_t     *tp)
{
        tp->t_dqinfo = kmem_cache_zalloc(xfs_dqtrx_cache,
                                         GFP_KERNEL | __GFP_NOFAIL);
}

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

int
xfs_quota_reserve_blkres(
        struct xfs_inode        *ip,
        int64_t                 blocks)
{
        if (XFS_IS_REALTIME_INODE(ip))
                return xfs_trans_reserve_quota_nblks(NULL, ip, 0, blocks,
                                false);
        return xfs_trans_reserve_quota_nblks(NULL, ip, blocks, 0, false);
}