root/fs/xfs/xfs_qm_syscalls.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2005 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_sb.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_quota.h"
#include "xfs_qm.h"
#include "xfs_icache.h"

int
xfs_qm_scall_quotaoff(
        xfs_mount_t             *mp,
        uint                    flags)
{
        /*
         * No file system can have quotas enabled on disk but not in core.
         * Note that quota utilities (like quotaoff) _expect_
         * errno == -EEXIST here.
         */
        if ((mp->m_qflags & flags) == 0)
                return -EEXIST;

        /*
         * We do not support actually turning off quota accounting any more.
         * Just log a warning and ignore the accounting related flags.
         */
        if (flags & XFS_ALL_QUOTA_ACCT)
                xfs_info(mp, "disabling of quota accounting not supported.");

        mutex_lock(&mp->m_quotainfo->qi_quotaofflock);
        mp->m_qflags &= ~(flags & XFS_ALL_QUOTA_ENFD);
        spin_lock(&mp->m_sb_lock);
        mp->m_sb.sb_qflags = mp->m_qflags;
        spin_unlock(&mp->m_sb_lock);
        mutex_unlock(&mp->m_quotainfo->qi_quotaofflock);

        /* XXX what to do if error ? Revert back to old vals incore ? */
        return xfs_sync_sb(mp, false);
}

STATIC int
xfs_qm_scall_trunc_qfile(
        struct xfs_mount        *mp,
        xfs_dqtype_t            type)
{
        struct xfs_inode        *ip;
        struct xfs_trans        *tp;
        int                     error;

        error = xfs_qm_qino_load(mp, type, &ip);
        if (error == -ENOENT)
                return 0;
        if (error)
                return error;

        xfs_ilock(ip, XFS_IOLOCK_EXCL);

        error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
        if (error) {
                xfs_iunlock(ip, XFS_IOLOCK_EXCL);
                goto out_put;
        }

        xfs_ilock(ip, XFS_ILOCK_EXCL);
        xfs_trans_ijoin(tp, ip, 0);

        ip->i_disk_size = 0;
        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

        error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, 0);
        if (error) {
                xfs_trans_cancel(tp);
                goto out_unlock;
        }

        ASSERT(ip->i_df.if_nextents == 0);

        xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
        error = xfs_trans_commit(tp);

out_unlock:
        xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
out_put:
        xfs_irele(ip);
        return error;
}

int
xfs_qm_scall_trunc_qfiles(
        xfs_mount_t     *mp,
        uint            flags)
{
        int             error = -EINVAL;

        if (!xfs_has_quota(mp) || flags == 0 ||
            (flags & ~XFS_QMOPT_QUOTALL)) {
                xfs_debug(mp, "%s: flags=%x m_qflags=%x",
                        __func__, flags, mp->m_qflags);
                return -EINVAL;
        }

        if (flags & XFS_QMOPT_UQUOTA) {
                error = xfs_qm_scall_trunc_qfile(mp, XFS_DQTYPE_USER);
                if (error)
                        return error;
        }
        if (flags & XFS_QMOPT_GQUOTA) {
                error = xfs_qm_scall_trunc_qfile(mp, XFS_DQTYPE_GROUP);
                if (error)
                        return error;
        }
        if (flags & XFS_QMOPT_PQUOTA)
                error = xfs_qm_scall_trunc_qfile(mp, XFS_DQTYPE_PROJ);

        return error;
}

/*
 * Switch on (a given) quota enforcement for a filesystem.  This takes
 * effect immediately.
 * (Switching on quota accounting must be done at mount time.)
 */
int
xfs_qm_scall_quotaon(
        xfs_mount_t     *mp,
        uint            flags)
{
        int             error;
        uint            qf;

        /*
         * Switching on quota accounting must be done at mount time,
         * only consider quota enforcement stuff here.
         */
        flags &= XFS_ALL_QUOTA_ENFD;

        if (flags == 0) {
                xfs_debug(mp, "%s: zero flags, m_qflags=%x",
                        __func__, mp->m_qflags);
                return -EINVAL;
        }

        /*
         * Can't enforce without accounting. We check the superblock
         * qflags here instead of m_qflags because rootfs can have
         * quota acct on ondisk without m_qflags' knowing.
         */
        if (((mp->m_sb.sb_qflags & XFS_UQUOTA_ACCT) == 0 &&
             (flags & XFS_UQUOTA_ENFD)) ||
            ((mp->m_sb.sb_qflags & XFS_GQUOTA_ACCT) == 0 &&
             (flags & XFS_GQUOTA_ENFD)) ||
            ((mp->m_sb.sb_qflags & XFS_PQUOTA_ACCT) == 0 &&
             (flags & XFS_PQUOTA_ENFD))) {
                xfs_debug(mp,
                        "%s: Can't enforce without acct, flags=%x sbflags=%x",
                        __func__, flags, mp->m_sb.sb_qflags);
                return -EINVAL;
        }
        /*
         * If everything's up to-date incore, then don't waste time.
         */
        if ((mp->m_qflags & flags) == flags)
                return -EEXIST;

        /*
         * Change sb_qflags on disk but not incore mp->qflags
         * if this is the root filesystem.
         */
        spin_lock(&mp->m_sb_lock);
        qf = mp->m_sb.sb_qflags;
        mp->m_sb.sb_qflags = qf | flags;
        spin_unlock(&mp->m_sb_lock);

        /*
         * There's nothing to change if it's the same.
         */
        if ((qf & flags) == flags)
                return -EEXIST;

        error = xfs_sync_sb(mp, false);
        if (error)
                return error;
        /*
         * If we aren't trying to switch on quota enforcement, we are done.
         */
        if  (((mp->m_sb.sb_qflags & XFS_UQUOTA_ACCT) !=
             (mp->m_qflags & XFS_UQUOTA_ACCT)) ||
             ((mp->m_sb.sb_qflags & XFS_PQUOTA_ACCT) !=
             (mp->m_qflags & XFS_PQUOTA_ACCT)) ||
             ((mp->m_sb.sb_qflags & XFS_GQUOTA_ACCT) !=
             (mp->m_qflags & XFS_GQUOTA_ACCT)))
                return 0;

        if (!XFS_IS_QUOTA_ON(mp))
                return -ESRCH;

        /*
         * Switch on quota enforcement in core.
         */
        mutex_lock(&mp->m_quotainfo->qi_quotaofflock);
        mp->m_qflags |= (flags & XFS_ALL_QUOTA_ENFD);
        mutex_unlock(&mp->m_quotainfo->qi_quotaofflock);

        return 0;
}

#define XFS_QC_MASK (QC_LIMIT_MASK | QC_TIMER_MASK)

/*
 * Adjust limits of this quota, and the defaults if passed in.  Returns true
 * if the new limits made sense and were applied, false otherwise.
 */
static inline bool
xfs_setqlim_limits(
        struct xfs_mount        *mp,
        struct xfs_dquot_res    *res,
        struct xfs_quota_limits *qlim,
        xfs_qcnt_t              hard,
        xfs_qcnt_t              soft,
        const char              *tag)
{
        /* The hard limit can't be less than the soft limit. */
        if (hard != 0 && hard < soft) {
                xfs_debug(mp, "%shard %lld < %ssoft %lld", tag, hard, tag,
                                soft);
                return false;
        }

        res->hardlimit = hard;
        res->softlimit = soft;
        if (qlim) {
                qlim->hard = hard;
                qlim->soft = soft;
        }

        return true;
}

static inline void
xfs_setqlim_timer(
        struct xfs_mount        *mp,
        struct xfs_dquot_res    *res,
        struct xfs_quota_limits *qlim,
        s64                     timer)
{
        if (qlim) {
                /* Set the length of the default grace period. */
                res->timer = xfs_dquot_set_grace_period(timer);
                qlim->time = res->timer;
        } else {
                /* Set the grace period expiration on a quota. */
                res->timer = xfs_dquot_set_timeout(mp, timer);
        }
}

/*
 * Adjust quota limits, and start/stop timers accordingly.
 */
int
xfs_qm_scall_setqlim(
        struct xfs_mount        *mp,
        xfs_dqid_t              id,
        xfs_dqtype_t            type,
        struct qc_dqblk         *newlim)
{
        struct xfs_quotainfo    *q = mp->m_quotainfo;
        struct xfs_dquot        *dqp;
        struct xfs_trans        *tp;
        struct xfs_def_quota    *defq;
        struct xfs_dquot_res    *res;
        struct xfs_quota_limits *qlim;
        int                     error;
        xfs_qcnt_t              hard, soft;

        if (newlim->d_fieldmask & ~XFS_QC_MASK)
                return -EINVAL;
        if ((newlim->d_fieldmask & XFS_QC_MASK) == 0)
                return 0;

        /*
         * Get the dquot (locked) before we start, as we need to do a
         * transaction to allocate it if it doesn't exist. Once we have the
         * dquot, unlock it so we can start the next transaction safely. We hold
         * a reference to the dquot, so it's safe to do this unlock/lock without
         * it being reclaimed in the mean time.
         */
        error = xfs_qm_dqget(mp, id, type, true, &dqp);
        if (error) {
                ASSERT(error != -ENOENT);
                return error;
        }

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

        error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_setqlim, 0, 0, 0, &tp);
        if (error)
                goto out_rele;

        mutex_lock(&dqp->q_qlock);
        xfs_trans_dqjoin(tp, dqp);

        /*
         * Update quota limits, warnings, and timers, and the defaults
         * if we're touching id == 0.
         *
         * Make sure that hardlimits are >= soft limits before changing.
         *
         * Update warnings counter(s) if requested.
         *
         * Timelimits for the super user set the relative time the other users
         * can be over quota for this file system. If it is zero a default is
         * used.  Ditto for the default soft and hard limit values (already
         * done, above), and for warnings.
         *
         * For other IDs, userspace can bump out the grace period if over
         * the soft limit.
         */

        /* Blocks on the data device. */
        hard = (newlim->d_fieldmask & QC_SPC_HARD) ?
                (xfs_qcnt_t) XFS_B_TO_FSB(mp, newlim->d_spc_hardlimit) :
                        dqp->q_blk.hardlimit;
        soft = (newlim->d_fieldmask & QC_SPC_SOFT) ?
                (xfs_qcnt_t) XFS_B_TO_FSB(mp, newlim->d_spc_softlimit) :
                        dqp->q_blk.softlimit;
        res = &dqp->q_blk;
        qlim = id == 0 ? &defq->blk : NULL;

        if (xfs_setqlim_limits(mp, res, qlim, hard, soft, "blk"))
                xfs_dquot_set_prealloc_limits(dqp);
        if (newlim->d_fieldmask & QC_SPC_TIMER)
                xfs_setqlim_timer(mp, res, qlim, newlim->d_spc_timer);

        /* Blocks on the realtime device. */
        hard = (newlim->d_fieldmask & QC_RT_SPC_HARD) ?
                (xfs_qcnt_t) XFS_B_TO_FSB(mp, newlim->d_rt_spc_hardlimit) :
                        dqp->q_rtb.hardlimit;
        soft = (newlim->d_fieldmask & QC_RT_SPC_SOFT) ?
                (xfs_qcnt_t) XFS_B_TO_FSB(mp, newlim->d_rt_spc_softlimit) :
                        dqp->q_rtb.softlimit;
        res = &dqp->q_rtb;
        qlim = id == 0 ? &defq->rtb : NULL;

        xfs_setqlim_limits(mp, res, qlim, hard, soft, "rtb");
        if (newlim->d_fieldmask & QC_RT_SPC_TIMER)
                xfs_setqlim_timer(mp, res, qlim, newlim->d_rt_spc_timer);

        /* Inodes */
        hard = (newlim->d_fieldmask & QC_INO_HARD) ?
                (xfs_qcnt_t) newlim->d_ino_hardlimit :
                        dqp->q_ino.hardlimit;
        soft = (newlim->d_fieldmask & QC_INO_SOFT) ?
                (xfs_qcnt_t) newlim->d_ino_softlimit :
                        dqp->q_ino.softlimit;
        res = &dqp->q_ino;
        qlim = id == 0 ? &defq->ino : NULL;

        xfs_setqlim_limits(mp, res, qlim, hard, soft, "ino");
        if (newlim->d_fieldmask & QC_INO_TIMER)
                xfs_setqlim_timer(mp, res, qlim, newlim->d_ino_timer);

        if (id != 0) {
                /*
                 * If the user is now over quota, start the timelimit.
                 * The user will not be 'warned'.
                 * Note that we keep the timers ticking, whether enforcement
                 * is on or off. We don't really want to bother with iterating
                 * over all ondisk dquots and turning the timers on/off.
                 */
                xfs_qm_adjust_dqtimers(dqp);
        }
        dqp->q_flags |= XFS_DQFLAG_DIRTY;
        xfs_trans_log_dquot(tp, dqp);

        error = xfs_trans_commit(tp);

out_rele:
        xfs_qm_dqrele(dqp);
        return error;
}

/* Fill out the quota context. */
static void
xfs_qm_scall_getquota_fill_qc(
        struct xfs_mount        *mp,
        xfs_dqtype_t            type,
        const struct xfs_dquot  *dqp,
        struct qc_dqblk         *dst)
{
        memset(dst, 0, sizeof(*dst));
        dst->d_spc_hardlimit = XFS_FSB_TO_B(mp, dqp->q_blk.hardlimit);
        dst->d_spc_softlimit = XFS_FSB_TO_B(mp, dqp->q_blk.softlimit);
        dst->d_ino_hardlimit = dqp->q_ino.hardlimit;
        dst->d_ino_softlimit = dqp->q_ino.softlimit;
        dst->d_space = XFS_FSB_TO_B(mp, dqp->q_blk.reserved);
        dst->d_ino_count = dqp->q_ino.reserved;
        dst->d_spc_timer = dqp->q_blk.timer;
        dst->d_ino_timer = dqp->q_ino.timer;
        dst->d_ino_warns = 0;
        dst->d_spc_warns = 0;
        dst->d_rt_spc_hardlimit = XFS_FSB_TO_B(mp, dqp->q_rtb.hardlimit);
        dst->d_rt_spc_softlimit = XFS_FSB_TO_B(mp, dqp->q_rtb.softlimit);
        dst->d_rt_space = XFS_FSB_TO_B(mp, dqp->q_rtb.reserved);
        dst->d_rt_spc_timer = dqp->q_rtb.timer;
        dst->d_rt_spc_warns = 0;

        /*
         * Internally, we don't reset all the timers when quota enforcement
         * gets turned off. No need to confuse the user level code,
         * so return zeroes in that case.
         */
        if (!xfs_dquot_is_enforced(dqp)) {
                dst->d_spc_timer = 0;
                dst->d_ino_timer = 0;
                dst->d_rt_spc_timer = 0;
        }
}

/* Return the quota information for the dquot matching id. */
int
xfs_qm_scall_getquota(
        struct xfs_mount        *mp,
        xfs_dqid_t              id,
        xfs_dqtype_t            type,
        struct qc_dqblk         *dst)
{
        struct xfs_dquot        *dqp;
        int                     error;

        /*
         * Expedite pending inodegc work at the start of a quota reporting
         * scan but don't block waiting for it to complete.
         */
        if (id == 0)
                xfs_inodegc_push(mp);

        /*
         * Try to get the dquot. We don't want it allocated on disk, so don't
         * set doalloc. If it doesn't exist, we'll get ENOENT back.
         */
        error = xfs_qm_dqget(mp, id, type, false, &dqp);
        if (error)
                return error;

        /*
         * If everything's NULL, this dquot doesn't quite exist as far as
         * our utility programs are concerned.
         */
        mutex_lock(&dqp->q_qlock);
        if (XFS_IS_DQUOT_UNINITIALIZED(dqp)) {
                error = -ENOENT;
                goto out_put;
        }

        xfs_qm_scall_getquota_fill_qc(mp, type, dqp, dst);

out_put:
        mutex_unlock(&dqp->q_qlock);
        xfs_qm_dqrele(dqp);
        return error;
}

/*
 * Return the quota information for the first initialized dquot whose id
 * is at least as high as id.
 */
int
xfs_qm_scall_getquota_next(
        struct xfs_mount        *mp,
        xfs_dqid_t              *id,
        xfs_dqtype_t            type,
        struct qc_dqblk         *dst)
{
        struct xfs_dquot        *dqp;
        int                     error;

        /* Flush inodegc work at the start of a quota reporting scan. */
        if (*id == 0)
                xfs_inodegc_push(mp);

        error = xfs_qm_dqget_next(mp, *id, type, &dqp);
        if (error)
                return error;

        /* Fill in the ID we actually read from disk */
        *id = dqp->q_id;

        xfs_qm_scall_getquota_fill_qc(mp, type, dqp, dst);
        mutex_unlock(&dqp->q_qlock);

        xfs_qm_dqrele(dqp);
        return error;
}