// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2006 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_quota.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_qm.h"


STATIC void
xfs_fill_statvfs_from_dquot(
        struct kstatfs          *statp,
        struct xfs_inode        *ip,
        struct xfs_dquot        *dqp)
{
        struct xfs_dquot_res    *blkres = &dqp->q_blk;
        uint64_t                limit;

        if (XFS_IS_REALTIME_MOUNT(ip->i_mount) &&
            (ip->i_diflags & (XFS_DIFLAG_RTINHERIT | XFS_DIFLAG_REALTIME)))
                blkres = &dqp->q_rtb;

        limit = blkres->softlimit ?
                blkres->softlimit :
                blkres->hardlimit;
        if (limit) {
                uint64_t        remaining = 0;

                if (limit > blkres->reserved)
                        remaining = limit - blkres->reserved;

                statp->f_blocks = min(statp->f_blocks, limit);
                statp->f_bfree = min(statp->f_bfree, remaining);
        }

        limit = dqp->q_ino.softlimit ?
                dqp->q_ino.softlimit :
                dqp->q_ino.hardlimit;
        if (limit) {
                uint64_t        remaining = 0;

                if (limit > dqp->q_ino.reserved)
                        remaining = limit - dqp->q_ino.reserved;

                statp->f_files = min(statp->f_files, limit);
                statp->f_ffree = min(statp->f_ffree, remaining);
        }
}


/*
 * Directory tree accounting is implemented using project quotas, where
 * the project identifier is inherited from parent directories.
 * A statvfs (df, etc.) of a directory that is using project quota should
 * return a statvfs of the project, not the entire filesystem.
 * This makes such trees appear as if they are filesystems in themselves.
 */
void
xfs_qm_statvfs(
        struct xfs_inode        *ip,
        struct kstatfs          *statp)
{
        struct xfs_mount        *mp = ip->i_mount;
        struct xfs_dquot        *dqp;

        if (!xfs_qm_dqget(mp, ip->i_projid, XFS_DQTYPE_PROJ, false, &dqp)) {
                mutex_lock(&dqp->q_qlock);
                xfs_fill_statvfs_from_dquot(statp, ip, dqp);
                mutex_unlock(&dqp->q_qlock);
                xfs_qm_dqrele(dqp);
        }
}

STATIC int
xfs_qm_validate_state_change(
        struct xfs_mount        *mp,
        uint                    uqd,
        uint                    gqd,
        uint                    pqd)
{
        int state;

        /* Is quota state changing? */
        state = ((uqd && !XFS_IS_UQUOTA_ON(mp)) ||
                (!uqd &&  XFS_IS_UQUOTA_ON(mp)) ||
                 (gqd && !XFS_IS_GQUOTA_ON(mp)) ||
                (!gqd &&  XFS_IS_GQUOTA_ON(mp)) ||
                 (pqd && !XFS_IS_PQUOTA_ON(mp)) ||
                (!pqd &&  XFS_IS_PQUOTA_ON(mp)));

        return  state &&
                (xfs_dev_is_read_only(mp, "changing quota state") ||
                xfs_has_norecovery(mp));
}

int
xfs_qm_newmount(
        xfs_mount_t     *mp,
        uint            *needquotamount,
        uint            *quotaflags)
{
        uint            quotaondisk;
        uint            uquotaondisk = 0, gquotaondisk = 0, pquotaondisk = 0;

        quotaondisk = xfs_has_quota(mp) &&
                                (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT);

        if (quotaondisk) {
                uquotaondisk = mp->m_sb.sb_qflags & XFS_UQUOTA_ACCT;
                pquotaondisk = mp->m_sb.sb_qflags & XFS_PQUOTA_ACCT;
                gquotaondisk = mp->m_sb.sb_qflags & XFS_GQUOTA_ACCT;
        }

        /*
         * If the device itself is read-only and/or in norecovery
         * mode, we can't allow the user to change the state of
         * quota on the mount - this would generate a transaction
         * on the ro device, which would lead to an I/O error and
         * shutdown.
         */

        if (xfs_qm_validate_state_change(mp, uquotaondisk,
                            gquotaondisk, pquotaondisk)) {

                if (xfs_has_metadir(mp))
                        xfs_warn(mp,
                "metadir enabled, please mount without any quota mount options");
                else
                        xfs_warn(mp, "please mount with%s%s%s%s.",
                                (!quotaondisk ? "out quota" : ""),
                                (uquotaondisk ? " usrquota" : ""),
                                (gquotaondisk ? " grpquota" : ""),
                                (pquotaondisk ? " prjquota" : ""));
                return -EPERM;
        }

        if (XFS_IS_QUOTA_ON(mp) || quotaondisk) {
                /*
                 * Call mount_quotas at this point only if we won't have to do
                 * a quotacheck.
                 */
                if (quotaondisk && !XFS_QM_NEED_QUOTACHECK(mp)) {
                        /*
                         * If an error occurred, qm_mount_quotas code
                         * has already disabled quotas. So, just finish
                         * mounting, and get on with the boring life
                         * without disk quotas.
                         */
                        xfs_qm_mount_quotas(mp);
                } else {
                        /*
                         * Clear the quota flags, but remember them. This
                         * is so that the quota code doesn't get invoked
                         * before we're ready. This can happen when an
                         * inode goes inactive and wants to free blocks,
                         * or via xfs_log_mount_finish.
                         */
                        *needquotamount = true;
                        *quotaflags = mp->m_qflags;
                        mp->m_qflags = 0;
                }
        }

        return 0;
}

/*
 * If the sysadmin didn't provide any quota mount options, restore the quota
 * accounting and enforcement state from the ondisk superblock.  Only do this
 * for metadir filesystems because this is a behavior change.
 */
void
xfs_qm_resume_quotaon(
        struct xfs_mount        *mp)
{
        if (!xfs_has_metadir(mp))
                return;
        if (xfs_has_norecovery(mp))
                return;

        mp->m_qflags = mp->m_sb.sb_qflags & (XFS_ALL_QUOTA_ACCT |
                                             XFS_ALL_QUOTA_ENFD);
}