/*
 * Copyright (c) 2000-2006 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_bit.h"
#include "xfs_log.h"
#include "xfs_inum.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_qm.h"


STATIC void
xfs_fill_statvfs_from_dquot(
        struct kstatfs          *statp,
        xfs_disk_dquot_t        *dp)
{
        __uint64_t              limit;

        limit = dp->d_blk_softlimit ?
                be64_to_cpu(dp->d_blk_softlimit) :
                be64_to_cpu(dp->d_blk_hardlimit);
        if (limit && statp->f_blocks > limit) {
                statp->f_blocks = limit;
                statp->f_bfree = statp->f_bavail =
                        (statp->f_blocks > be64_to_cpu(dp->d_bcount)) ?
                         (statp->f_blocks - be64_to_cpu(dp->d_bcount)) : 0;
        }

        limit = dp->d_ino_softlimit ?
                be64_to_cpu(dp->d_ino_softlimit) :
                be64_to_cpu(dp->d_ino_hardlimit);
        if (limit && statp->f_files > limit) {
                statp->f_files = limit;
                statp->f_ffree =
                        (statp->f_files > be64_to_cpu(dp->d_icount)) ?
                         (statp->f_ffree - be64_to_cpu(dp->d_icount)) : 0;
        }
}


/*
 * 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(
        xfs_inode_t             *ip,
        struct kstatfs          *statp)
{
        xfs_mount_t             *mp = ip->i_mount;
        xfs_dquot_t             *dqp;

        if (!xfs_qm_dqget(mp, NULL, xfs_get_projid(ip), XFS_DQ_PROJ, 0, &dqp)) {
                xfs_fill_statvfs_from_dquot(statp, &dqp->q_core);
                xfs_qm_dqput(dqp);
        }
}

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

        quotaondisk = xfs_sb_version_hasquota(&mp->m_sb) &&
                                (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, 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 (((uquotaondisk && !XFS_IS_UQUOTA_ON(mp)) ||
            (!uquotaondisk &&  XFS_IS_UQUOTA_ON(mp)) ||
             (pquotaondisk && !XFS_IS_PQUOTA_ON(mp)) ||
            (!pquotaondisk &&  XFS_IS_PQUOTA_ON(mp)) ||
             (gquotaondisk && !XFS_IS_GQUOTA_ON(mp)) ||
            (!gquotaondisk &&  XFS_IS_OQUOTA_ON(mp)))  &&
            xfs_dev_is_read_only(mp, "changing quota state")) {
                cmn_err(CE_WARN,
                        "XFS: please mount with%s%s%s%s.",
                        (!quotaondisk ? "out quota" : ""),
                        (uquotaondisk ? " usrquota" : ""),
                        (pquotaondisk ? " prjquota" : ""),
                        (gquotaondisk ? " grpquota" : ""));
                return XFS_ERROR(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 occured, 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 = B_TRUE;
                        *quotaflags = mp->m_qflags;
                        mp->m_qflags = 0;
                }
        }

        return 0;
}

void __init
xfs_qm_init(void)
{
        printk(KERN_INFO "SGI XFS Quota Management subsystem\n");
        mutex_init(&xfs_Gqm_lock);
        xfs_qm_init_procfs();
}

void __exit
xfs_qm_exit(void)
{
        xfs_qm_cleanup_procfs();
        if (qm_dqzone)
                kmem_zone_destroy(qm_dqzone);
        if (qm_dqtrxzone)
                kmem_zone_destroy(qm_dqtrxzone);
}