/*      $NetBSD: ufs_quota.c,v 1.120 2026/01/22 03:24:19 riastradh Exp $        */

/*
 * Copyright (c) 1982, 1986, 1990, 1993, 1995
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Robert Elz at The University of Melbourne.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)ufs_quota.c 8.5 (Berkeley) 5/20/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ufs_quota.c,v 1.120 2026/01/22 03:24:19 riastradh Exp $");

#if defined(_KERNEL_OPT)
#include "opt_quota.h"
#endif

#include <sys/param.h>
#include <sys/types.h>

#include <sys/file.h>
#include <sys/kauth.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/quotactl.h>
#include <sys/sdt.h>
#include <sys/systm.h>
#include <sys/vnode.h>

#include <ufs/ufs/inode.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ufs/ufs_quota.h>
#include <ufs/ufs/ufsmount.h>

kmutex_t dqlock;
kcondvar_t dqcv;
const char *quotatypes[MAXQUOTAS] = INITQFNAMES;

/*
 * Code pertaining to management of the in-core dquot data structures.
 */
#define DQHASH(dqvp, id) \
        (((((long)(dqvp)) >> 8) + id) & dqhash)
static LIST_HEAD(dqhashhead, dquot) *dqhashtbl;
static u_long dqhash;
static pool_cache_t dquot_cache;


static int quota_handle_cmd_stat(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_idtypestat(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_objtypestat(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_get(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_put(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_cursorget(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_del(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_quotaon(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_quotaoff(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_cursoropen(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_cursorclose(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_cursorskipidtype(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_cursoratend(struct mount *, struct lwp *,
    struct quotactl_args *args);
static int quota_handle_cmd_cursorrewind(struct mount *, struct lwp *,
    struct quotactl_args *args);

/*
 * Initialize the quota fields of an inode.
 */
void
ufsquota_init(struct inode *ip)
{
        int i;

        for (i = 0; i < MAXQUOTAS; i++)
                ip->i_dquot[i] = NODQUOT;
}

/*
 * Release the quota fields from an inode.
 */
void
ufsquota_free(struct inode *ip)
{
        int i;

        for (i = 0; i < MAXQUOTAS; i++) {
                dqrele(ITOV(ip), ip->i_dquot[i]);
                ip->i_dquot[i] = NODQUOT;
        }
}

/*
 * Update disk usage, and take corrective action.
 */
int
chkdq(struct inode *ip, int64_t change, kauth_cred_t cred, int flags)
{
        /* do not track snapshot usage, or we will deadlock */
        if ((ip->i_flags & SF_SNAPSHOT) != 0)
                return 0;

#ifdef QUOTA
        if (ip->i_ump->um_flags & UFS_QUOTA)
                return chkdq1(ip, change, cred, flags);
#endif
#ifdef QUOTA2
        if (ip->i_ump->um_flags & UFS_QUOTA2)
                return chkdq2(ip, change, cred, flags);
#endif
        return 0;
}

/*
 * Check the inode limit, applying corrective action.
 */
int
chkiq(struct inode *ip, int32_t change, kauth_cred_t cred, int flags)
{
        /* do not track snapshot usage, or we will deadlock */
        if ((ip->i_flags & SF_SNAPSHOT) != 0)
                return 0;
#ifdef QUOTA
        if (ip->i_ump->um_flags & UFS_QUOTA)
                return chkiq1(ip, change, cred, flags);
#endif
#ifdef QUOTA2
        if (ip->i_ump->um_flags & UFS_QUOTA2)
                return chkiq2(ip, change, cred, flags);
#endif
        return 0;
}

int
quota_handle_cmd(struct mount *mp, struct lwp *l,
                 struct quotactl_args *args)
{
        int error = 0;

        switch (args->qc_op) {
        case QUOTACTL_STAT:
                error = quota_handle_cmd_stat(mp, l, args);
                break;
        case QUOTACTL_IDTYPESTAT:
                error = quota_handle_cmd_idtypestat(mp, l, args);
                break;
        case QUOTACTL_OBJTYPESTAT:
                error = quota_handle_cmd_objtypestat(mp, l, args);
                break;
        case QUOTACTL_QUOTAON:
                error = quota_handle_cmd_quotaon(mp, l, args);
                break;
        case QUOTACTL_QUOTAOFF:
                error = quota_handle_cmd_quotaoff(mp, l, args);
                break;
        case QUOTACTL_GET:
                error = quota_handle_cmd_get(mp, l, args);
                break;
        case QUOTACTL_PUT:
                error = quota_handle_cmd_put(mp, l, args);
                break;
        case QUOTACTL_CURSORGET:
                error = quota_handle_cmd_cursorget(mp, l, args);
                break;
        case QUOTACTL_DEL:
                error = quota_handle_cmd_del(mp, l, args);
                break;
        case QUOTACTL_CURSOROPEN:
                error = quota_handle_cmd_cursoropen(mp, l, args);
                break;
        case QUOTACTL_CURSORCLOSE:
                error = quota_handle_cmd_cursorclose(mp, l, args);
                break;
        case QUOTACTL_CURSORSKIPIDTYPE:
                error = quota_handle_cmd_cursorskipidtype(mp, l, args);
                break;
        case QUOTACTL_CURSORATEND:
                error = quota_handle_cmd_cursoratend(mp, l, args);
                break;
        case QUOTACTL_CURSORREWIND:
                error = quota_handle_cmd_cursorrewind(mp, l, args);
                break;
        default:
                panic("Invalid quotactl operation %d\n", args->qc_op);
        }

        return error;
}

static int
quota_handle_cmd_stat(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        struct quotastat *info;

        KASSERT(args->qc_op == QUOTACTL_STAT);
        info = args->u.stat.qc_info;

        if ((ump->um_flags & (UFS_QUOTA|UFS_QUOTA2)) == 0)
                return SET_ERROR(EOPNOTSUPP);

#ifdef QUOTA
        if (ump->um_flags & UFS_QUOTA) {
                strcpy(info->qs_implname, "ufs/ffs quota v1");
                info->qs_numidtypes = MAXQUOTAS;
                /* XXX no define for this */
                info->qs_numobjtypes = 2;
                info->qs_restrictions = 0;
                info->qs_restrictions |= QUOTA_RESTRICT_NEEDSQUOTACHECK;
                info->qs_restrictions |= QUOTA_RESTRICT_UNIFORMGRACE;
                info->qs_restrictions |= QUOTA_RESTRICT_32BIT;
        } else
#endif
#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                strcpy(info->qs_implname, "ufs/ffs quota v2");
                info->qs_numidtypes = MAXQUOTAS;
                info->qs_numobjtypes = N_QL;
                info->qs_restrictions = 0;
        } else
#endif
                return SET_ERROR(EOPNOTSUPP);

        return 0;
}

static int
quota_handle_cmd_idtypestat(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        int idtype;
        struct quotaidtypestat *info;
        const char *name;

        KASSERT(args->qc_op == QUOTACTL_IDTYPESTAT);
        idtype = args->u.idtypestat.qc_idtype;
        info = args->u.idtypestat.qc_info;

        if ((ump->um_flags & (UFS_QUOTA|UFS_QUOTA2)) == 0)
                return SET_ERROR(EOPNOTSUPP);

        /*
         * These are the same for both QUOTA and QUOTA2.
         */
        switch (idtype) {
        case QUOTA_IDTYPE_USER:
                name = "user";
                break;
        case QUOTA_IDTYPE_GROUP:
                name = "group";
                break;
        default:
                return SET_ERROR(EINVAL);
        }
        strlcpy(info->qis_name, name, sizeof(info->qis_name));
        return 0;
}

static int
quota_handle_cmd_objtypestat(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        int objtype;
        struct quotaobjtypestat *info;
        const char *name;
        int isbytes;

        KASSERT(args->qc_op == QUOTACTL_OBJTYPESTAT);
        objtype = args->u.objtypestat.qc_objtype;
        info = args->u.objtypestat.qc_info;

        if ((ump->um_flags & (UFS_QUOTA|UFS_QUOTA2)) == 0)
                return SET_ERROR(EOPNOTSUPP);

        /*
         * These are the same for both QUOTA and QUOTA2.
         */
        switch (objtype) {
        case QUOTA_OBJTYPE_BLOCKS:
                name = "block";
                isbytes = 1;
                break;
        case QUOTA_OBJTYPE_FILES:
                name = "file";
                isbytes = 0;
                break;
        default:
                return SET_ERROR(EINVAL);
        }
        strlcpy(info->qos_name, name, sizeof(info->qos_name));
        info->qos_isbytes = isbytes;
        return 0;
}

/* XXX shouldn't all this be in kauth ? */
static int
quota_get_auth(struct mount *mp, struct lwp *l, uid_t id) {
        /* The user can always query about his own quota. */
        if (id == kauth_cred_geteuid(l->l_cred))
                return 0;
        return kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_QUOTA,
            KAUTH_REQ_SYSTEM_FS_QUOTA_GET, mp, KAUTH_ARG(id), NULL);
}

static int
quota_handle_cmd_get(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        int error;
        const struct quotakey *qk;
        struct quotaval *qv;

        KASSERT(args->qc_op == QUOTACTL_GET);
        qk = args->u.get.qc_key;
        qv = args->u.get.qc_val;

        if ((ump->um_flags & (UFS_QUOTA|UFS_QUOTA2)) == 0)
                return SET_ERROR(EOPNOTSUPP);

        error = quota_get_auth(mp, l, qk->qk_id);
        if (error != 0)
                return error;
#ifdef QUOTA
        if (ump->um_flags & UFS_QUOTA) {
                error = quota1_handle_cmd_get(ump, qk, qv);
        } else
#endif
#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                error = quota2_handle_cmd_get(ump, qk, qv);
        } else
#endif
                panic("quota_handle_cmd_get: no support ?");

        if (error != 0)
                return error;

        return error;
}

static int
quota_handle_cmd_put(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        const struct quotakey *qk;
        const struct quotaval *qv;
        id_t kauth_id;
        int error;

        KASSERT(args->qc_op == QUOTACTL_PUT);
        qk = args->u.put.qc_key;
        qv = args->u.put.qc_val;

        if ((ump->um_flags & (UFS_QUOTA|UFS_QUOTA2)) == 0)
                return SET_ERROR(EOPNOTSUPP);

        kauth_id = qk->qk_id;
        if (kauth_id == QUOTA_DEFAULTID) {
                kauth_id = 0;
        }

        error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_QUOTA,
            KAUTH_REQ_SYSTEM_FS_QUOTA_MANAGE, mp, KAUTH_ARG(kauth_id),
            NULL);
        if (error != 0) {
                return error;
        }

#ifdef QUOTA
        if (ump->um_flags & UFS_QUOTA)
                error = quota1_handle_cmd_put(ump, qk, qv);
        else
#endif
#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                error = quota2_handle_cmd_put(ump, qk, qv);
        } else
#endif
                panic("quota_handle_cmd_get: no support ?");

        if (error == ENOENT) {
                error = 0;
        }

        return error;
}

static int
quota_handle_cmd_del(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        const struct quotakey *qk;
        id_t kauth_id;
        int error;

        KASSERT(args->qc_op == QUOTACTL_DEL);
        qk = args->u.del.qc_key;

        kauth_id = qk->qk_id;
        if (kauth_id == QUOTA_DEFAULTID) {
                kauth_id = 0;
        }

        if ((ump->um_flags & UFS_QUOTA2) == 0)
                return SET_ERROR(EOPNOTSUPP);

        /* avoid whitespace changes */
        {
                error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_QUOTA,
                    KAUTH_REQ_SYSTEM_FS_QUOTA_MANAGE, mp, KAUTH_ARG(kauth_id),
                    NULL);
                if (error != 0)
                        goto err;
#ifdef QUOTA2
                if (ump->um_flags & UFS_QUOTA2) {
                        error = quota2_handle_cmd_del(ump, qk);
                } else
#endif
                        panic("quota_handle_cmd_get: no support ?");

                if (error && error != ENOENT)
                        goto err;
        }

        return 0;
 err:
        return error;
}

static int
quota_handle_cmd_cursorget(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        int error;

        KASSERT(args->qc_op == QUOTACTL_CURSORGET);

        if ((ump->um_flags & UFS_QUOTA2) == 0)
                return SET_ERROR(EOPNOTSUPP);

        error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_QUOTA,
            KAUTH_REQ_SYSTEM_FS_QUOTA_GET, mp, NULL, NULL);
        if (error)
                return error;

#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                struct quotakcursor *cursor = args->u.cursorget.qc_cursor;
                struct quotakey *keys = args->u.cursorget.qc_keys;
                struct quotaval *vals = args->u.cursorget.qc_vals;
                unsigned maxnum = args->u.cursorget.qc_maxnum;
                unsigned *ret = args->u.cursorget.qc_ret;

                error = quota2_handle_cmd_cursorget(ump, cursor, keys, vals,
                                                    maxnum, ret);
        } else
#endif
                panic("quota_handle_cmd_cursorget: no support ?");

        return error;
}

static int
quota_handle_cmd_cursoropen(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
#ifdef QUOTA2
        struct ufsmount *ump = VFSTOUFS(mp);
        struct quotakcursor *cursor = args->u.cursoropen.qc_cursor;
#endif
        int error;

        KASSERT(args->qc_op == QUOTACTL_CURSOROPEN);

        error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_QUOTA,
            KAUTH_REQ_SYSTEM_FS_QUOTA_GET, mp, NULL, NULL);
        if (error)
                return error;

#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                error = quota2_handle_cmd_cursoropen(ump, cursor);
        } else
#endif
                error = SET_ERROR(EOPNOTSUPP);

        return error;
}

static int
quota_handle_cmd_cursorclose(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
#ifdef QUOTA2
        struct ufsmount *ump = VFSTOUFS(mp);
        struct quotakcursor *cursor = args->u.cursorclose.qc_cursor;
#endif
        int error;

        KASSERT(args->qc_op == QUOTACTL_CURSORCLOSE);

        error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_QUOTA,
            KAUTH_REQ_SYSTEM_FS_QUOTA_GET, mp, NULL, NULL);
        if (error)
                return error;

#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                error = quota2_handle_cmd_cursorclose(ump, cursor);
        } else
#endif
                error = SET_ERROR(EOPNOTSUPP);

        return error;
}

static int
quota_handle_cmd_cursorskipidtype(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
#ifdef QUOTA2
        struct ufsmount *ump = VFSTOUFS(mp);
        struct quotakcursor *cursor = args->u.cursorskipidtype.qc_cursor;
        int idtype = args->u.cursorskipidtype.qc_idtype;
#endif
        int error;

        KASSERT(args->qc_op == QUOTACTL_CURSORSKIPIDTYPE);

#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                error = quota2_handle_cmd_cursorskipidtype(ump, cursor, idtype);
        } else
#endif
                error = SET_ERROR(EOPNOTSUPP);

        return error;
}

static int
quota_handle_cmd_cursoratend(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
#ifdef QUOTA2
        struct ufsmount *ump = VFSTOUFS(mp);
        struct quotakcursor *cursor = args->u.cursoratend.qc_cursor;
        unsigned *ret = args->u.cursoratend.qc_ret;
#endif
        int error;

        KASSERT(args->qc_op == QUOTACTL_CURSORATEND);

#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                error = quota2_handle_cmd_cursoratend(ump, cursor, ret);
        } else
#endif
                error = SET_ERROR(EOPNOTSUPP);

        return error;
}

static int
quota_handle_cmd_cursorrewind(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
#ifdef QUOTA2
        struct ufsmount *ump = VFSTOUFS(mp);
        struct quotakcursor *cursor = args->u.cursorrewind.qc_cursor;
#endif
        int error;

        KASSERT(args->qc_op == QUOTACTL_CURSORREWIND);

#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                error = quota2_handle_cmd_cursorrewind(ump, cursor);
        } else
#endif
                error = SET_ERROR(EOPNOTSUPP);

        return error;
}

static int
quota_handle_cmd_quotaon(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        int error;

        KASSERT(args->qc_op == QUOTACTL_QUOTAON);

        if ((ump->um_flags & UFS_QUOTA2) != 0)
                return SET_ERROR(EBUSY);

        error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_QUOTA,
            KAUTH_REQ_SYSTEM_FS_QUOTA_ONOFF, mp, NULL, NULL);
        if (error != 0) {
                return error;
        }
#ifdef QUOTA
        int idtype = args->u.quotaon.qc_idtype;
        const char *qfile = args->u.quotaon.qc_quotafile;
        error = quota1_handle_cmd_quotaon(l, ump, idtype, qfile);
#else
        error = SET_ERROR(EOPNOTSUPP);
#endif

        return error;
}

static int
quota_handle_cmd_quotaoff(struct mount *mp, struct lwp *l,
    struct quotactl_args *args)
{
        struct ufsmount *ump = VFSTOUFS(mp);
        int error;

        KASSERT(args->qc_op == QUOTACTL_QUOTAOFF);

        if ((ump->um_flags & UFS_QUOTA2) != 0)
                return SET_ERROR(EOPNOTSUPP);

        error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_QUOTA,
            KAUTH_REQ_SYSTEM_FS_QUOTA_ONOFF, mp, NULL, NULL);
        if (error != 0) {
                return error;
        }
#ifdef QUOTA
        int idtype = args->u.quotaoff.qc_idtype;
        error = quota1_handle_cmd_quotaoff(l, ump, idtype);
#else
        error = SET_ERROR(EOPNOTSUPP);
#endif

        return error;
}

/*
 * Initialize the quota system.
 */
void
dqinit(void)
{

        mutex_init(&dqlock, MUTEX_DEFAULT, IPL_NONE);
        cv_init(&dqcv, "quota");
        dqhashtbl = hashinit(desiredvnodes, HASH_LIST, true, &dqhash);
        dquot_cache = pool_cache_init(sizeof(struct dquot), 0, 0, 0, "ufsdq",
            NULL, IPL_NONE, NULL, NULL, NULL);
}

void
dqreinit(void)
{
        struct dquot *dq;
        struct dqhashhead *oldhash, *hash;
        struct vnode *dqvp;
        u_long oldmask, mask, hashval;
        int i;

        hash = hashinit(desiredvnodes, HASH_LIST, true, &mask);
        mutex_enter(&dqlock);
        oldhash = dqhashtbl;
        oldmask = dqhash;
        dqhashtbl = hash;
        dqhash = mask;
        for (i = 0; i <= oldmask; i++) {
                while ((dq = LIST_FIRST(&oldhash[i])) != NULL) {
                        dqvp = dq->dq_ump->um_quotas[dq->dq_type];
                        LIST_REMOVE(dq, dq_hash);
                        hashval = DQHASH(dqvp, dq->dq_id);
                        LIST_INSERT_HEAD(&dqhashtbl[hashval], dq, dq_hash);
                }
        }
        mutex_exit(&dqlock);
        hashdone(oldhash, HASH_LIST, oldmask);
}

/*
 * Free resources held by quota system.
 */
void
dqdone(void)
{

        pool_cache_destroy(dquot_cache);
        hashdone(dqhashtbl, HASH_LIST, dqhash);
        cv_destroy(&dqcv);
        mutex_destroy(&dqlock);
}

/*
 * Set up the quotas for an inode.
 *
 * This routine completely defines the semantics of quotas.
 * If other criterion want to be used to establish quotas, the
 * MAXQUOTAS value in quotas.h should be increased, and the
 * additional dquots set up here.
 */
int
getinoquota(struct inode *ip)
{
        struct ufsmount *ump = ip->i_ump;
        struct vnode *vp = ITOV(ip);
        int i, error;
        u_int32_t ino_ids[MAXQUOTAS];

        /*
         * To avoid deadlocks never update quotas for quota files
         * on the same file system
         */
        for (i = 0; i < MAXQUOTAS; i++)
                if (vp == ump->um_quotas[i])
                        return 0;

        ino_ids[USRQUOTA] = ip->i_uid;
        ino_ids[GRPQUOTA] = ip->i_gid;
        for (i = 0; i < MAXQUOTAS; i++) {
                /*
                 * If the file id changed the quota needs update.
                 */
                if (ip->i_dquot[i] != NODQUOT &&
                    ip->i_dquot[i]->dq_id != ino_ids[i]) {
                        dqrele(ITOV(ip), ip->i_dquot[i]);
                        ip->i_dquot[i] = NODQUOT;
                }
                /*
                 * Set up the quota based on file id.
                 * ENODEV means that quotas are not enabled.
                 */
                if (ip->i_dquot[i] == NODQUOT &&
                    (error = dqget(vp, ino_ids[i], ump, i, &ip->i_dquot[i])) &&
                    error != ENODEV)
                        return error;
        }
        return 0;
}

/*
 * Obtain a dquot structure for the specified identifier and quota file
 * reading the information from the file if necessary.
 */
int
dqget(struct vnode *vp, u_long id, struct ufsmount *ump, int type,
    struct dquot **dqp)
{
        struct dquot *dq, *ndq;
        struct dqhashhead *dqh;
        struct vnode *dqvp;
        int error = 0; /* XXX gcc */

        /* Lock to see an up to date value for QTF_CLOSING. */
        mutex_enter(&dqlock);
        if ((ump->um_flags & (UFS_QUOTA|UFS_QUOTA2)) == 0) {
                mutex_exit(&dqlock);
                *dqp = NODQUOT;
                return SET_ERROR(ENODEV);
        }
        dqvp = ump->um_quotas[type];
#ifdef QUOTA
        if (ump->um_flags & UFS_QUOTA) {
                if (dqvp == NULLVP || (ump->umq1_qflags[type] & QTF_CLOSING)) {
                        mutex_exit(&dqlock);
                        *dqp = NODQUOT;
                        return SET_ERROR(ENODEV);
                }
        }
#endif
#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2) {
                if (dqvp == NULLVP) {
                        mutex_exit(&dqlock);
                        *dqp = NODQUOT;
                        return SET_ERROR(ENODEV);
                }
        }
#endif
        KASSERT(dqvp != vp);
        /*
         * Check the cache first.
         */
        dqh = &dqhashtbl[DQHASH(dqvp, id)];
        LIST_FOREACH(dq, dqh, dq_hash) {
                if (dq->dq_id != id ||
                    dq->dq_ump->um_quotas[dq->dq_type] != dqvp)
                        continue;
                KASSERT(dq->dq_cnt > 0);
                dqref(dq);
                mutex_exit(&dqlock);
                *dqp = dq;
                return 0;
        }
        /*
         * Not in cache, allocate a new one.
         */
        mutex_exit(&dqlock);
        ndq = pool_cache_get(dquot_cache, PR_WAITOK);
        /*
         * Initialize the contents of the dquot structure.
         */
        memset((char *)ndq, 0, sizeof *ndq);
        ndq->dq_flags = 0;
        ndq->dq_id = id;
        ndq->dq_ump = ump;
        ndq->dq_type = type;
        mutex_init(&ndq->dq_interlock, MUTEX_DEFAULT, IPL_NONE);
        mutex_enter(&dqlock);
        dqh = &dqhashtbl[DQHASH(dqvp, id)];
        LIST_FOREACH(dq, dqh, dq_hash) {
                if (dq->dq_id != id ||
                    dq->dq_ump->um_quotas[dq->dq_type] != dqvp)
                        continue;
                /*
                 * Another thread beat us allocating this dquot.
                 */
                KASSERT(dq->dq_cnt > 0);
                dqref(dq);
                mutex_exit(&dqlock);
                mutex_destroy(&ndq->dq_interlock);
                pool_cache_put(dquot_cache, ndq);
                *dqp = dq;
                return 0;
        }
        dq = ndq;
        LIST_INSERT_HEAD(dqh, dq, dq_hash);
        dqref(dq);
        mutex_enter(&dq->dq_interlock);
        mutex_exit(&dqlock);
#ifdef QUOTA
        if (ump->um_flags & UFS_QUOTA)
                error = dq1get(dqvp, id, ump, type, dq);
#endif
#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2)
                error = dq2get(dqvp, id, ump, type, dq);
#endif
        /*
         * I/O error in reading quota file, release
         * quota structure and reflect problem to caller.
         */
        if (error) {
                mutex_enter(&dqlock);
                LIST_REMOVE(dq, dq_hash);
                mutex_exit(&dqlock);
                mutex_exit(&dq->dq_interlock);
                dqrele(vp, dq);
                *dqp = NODQUOT;
                return error;
        }
        mutex_exit(&dq->dq_interlock);
        *dqp = dq;
        return 0;
}

/*
 * Obtain a reference to a dquot.
 */
void
dqref(struct dquot *dq)
{

        KASSERT(mutex_owned(&dqlock));
        dq->dq_cnt++;
        KASSERT(dq->dq_cnt > 0);
}

/*
 * Release a reference to a dquot.
 */
void
dqrele(struct vnode *vp, struct dquot *dq)
{

        if (dq == NODQUOT)
                return;
        mutex_enter(&dq->dq_interlock);
        for (;;) {
                mutex_enter(&dqlock);
                if (dq->dq_cnt > 1) {
                        dq->dq_cnt--;
                        mutex_exit(&dqlock);
                        mutex_exit(&dq->dq_interlock);
                        return;
                }
                if ((dq->dq_flags & DQ_MOD) == 0)
                        break;
                mutex_exit(&dqlock);
#ifdef QUOTA
                if (dq->dq_ump->um_flags & UFS_QUOTA)
                        (void) dq1sync(vp, dq);
#endif
#ifdef QUOTA2
                if (dq->dq_ump->um_flags & UFS_QUOTA2)
                        (void) dq2sync(vp, dq);
#endif
        }
        KASSERT(dq->dq_cnt == 1 && (dq->dq_flags & DQ_MOD) == 0);
        LIST_REMOVE(dq, dq_hash);
        mutex_exit(&dqlock);
        mutex_exit(&dq->dq_interlock);
        mutex_destroy(&dq->dq_interlock);
        pool_cache_put(dquot_cache, dq);
}

int
qsync(struct mount *mp)
{
        struct ufsmount *ump = VFSTOUFS(mp);
#ifdef QUOTA
        if (ump->um_flags & UFS_QUOTA)
                return q1sync(mp);
#endif
#ifdef QUOTA2
        if (ump->um_flags & UFS_QUOTA2)
                return q2sync(mp);
#endif
        return 0;
}

#ifdef DIAGNOSTIC
/*
 * Check the hash chains for stray dquot's.
 */
void
dqflush(struct vnode *vp)
{
        struct dquot *dq;
        int i;

        mutex_enter(&dqlock);
        for (i = 0; i <= dqhash; i++)
                LIST_FOREACH(dq, &dqhashtbl[i], dq_hash)
                        KASSERT(dq->dq_ump->um_quotas[dq->dq_type] != vp);
        mutex_exit(&dqlock);
}
#endif