// SPDX-License-Identifier: GPL-2.0

  /*
   * Quota code necessary even when VFS quota support is not compiled
   * into the kernel.  The interesting stuff is over in dquot.c, here
   * we have symbols for initial quotactl(2) handling, the sysctl(2)
   * variables, etc - things needed even when quota support disabled.
   */
  
  #include <linux/fs.h>
  #include <linux/namei.h>
  #include <linux/slab.h>
  #include <asm/current.h>

  #include <linux/uaccess.h>

  #include <linux/kernel.h>

  #include <linux/security.h>
  #include <linux/syscalls.h>

  #include <linux/capability.h>

  #include <linux/quotaops.h>

  #include <linux/types.h>

  #include <linux/writeback.h>

  #include <linux/nospec.h>

  #include "compat.h"

  static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
  				     qid_t id)

  {

  	switch (cmd) {
  	/* these commands do not require any special privilegues */
  	case Q_GETFMT:
  	case Q_SYNC:
  	case Q_GETINFO:
  	case Q_XGETQSTAT:

  	case Q_XGETQSTATV:

  	case Q_XQUOTASYNC:
  		break;
  	/* allow to query information for dquots we "own" */
  	case Q_GETQUOTA:
  	case Q_XGETQUOTA:

  		if ((type == USRQUOTA && uid_eq(current_euid(), make_kuid(current_user_ns(), id))) ||
  		    (type == GRPQUOTA && in_egroup_p(make_kgid(current_user_ns(), id))))

  			break;

  		fallthrough;

  	default:

  		if (!capable(CAP_SYS_ADMIN))
  			return -EPERM;
  	}

  	return security_quotactl(cmd, type, id, sb);

  }

  static void quota_sync_one(struct super_block *sb, void *arg)
  {

  	int type = *(int *)arg;
  
  	if (sb->s_qcop && sb->s_qcop->quota_sync &&
  	    (sb->s_quota_types & (1 << type)))
  		sb->s_qcop->quota_sync(sb, type);

  }

  static int quota_sync_all(int type)

  {

  	int ret;

  	ret = security_quotactl(Q_SYNC, type, 0, NULL);

  	if (!ret)
  		iterate_supers(quota_sync_one, &type);
  	return ret;

  }

  unsigned int qtype_enforce_flag(int type)
  {
  	switch (type) {
  	case USRQUOTA:
  		return FS_QUOTA_UDQ_ENFD;
  	case GRPQUOTA:
  		return FS_QUOTA_GDQ_ENFD;
  	case PRJQUOTA:
  		return FS_QUOTA_PDQ_ENFD;
  	}
  	return 0;
  }

  static int quota_quotaon(struct super_block *sb, int type, qid_t id,

  		         const struct path *path)

  {

  	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)

  		return -ENOSYS;

  	if (sb->s_qcop->quota_enable)
  		return sb->s_qcop->quota_enable(sb, qtype_enforce_flag(type));

  	if (IS_ERR(path))
  		return PTR_ERR(path);
  	return sb->s_qcop->quota_on(sb, type, id, path);

  }

  static int quota_quotaoff(struct super_block *sb, int type)
  {
  	if (!sb->s_qcop->quota_off && !sb->s_qcop->quota_disable)
  		return -ENOSYS;
  	if (sb->s_qcop->quota_disable)
  		return sb->s_qcop->quota_disable(sb, qtype_enforce_flag(type));
  	return sb->s_qcop->quota_off(sb, type);
  }

  static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
  {
  	__u32 fmt;

  	if (!sb_has_quota_active(sb, type))

  		return -ESRCH;

  	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;

  	if (copy_to_user(addr, &fmt, sizeof(fmt)))
  		return -EFAULT;
  	return 0;
  }

  static int quota_getinfo(struct super_block *sb, int type, void __user *addr)
  {

  	struct qc_state state;
  	struct qc_type_state *tstate;
  	struct if_dqinfo uinfo;

  	int ret;

  	if (!sb->s_qcop->get_state)

  		return -ENOSYS;

  	ret = sb->s_qcop->get_state(sb, &state);
  	if (ret)
  		return ret;
  	tstate = state.s_state + type;
  	if (!(tstate->flags & QCI_ACCT_ENABLED))
  		return -ESRCH;
  	memset(&uinfo, 0, sizeof(uinfo));
  	uinfo.dqi_bgrace = tstate->spc_timelimit;
  	uinfo.dqi_igrace = tstate->ino_timelimit;
  	if (tstate->flags & QCI_SYSFILE)
  		uinfo.dqi_flags |= DQF_SYS_FILE;
  	if (tstate->flags & QCI_ROOT_SQUASH)
  		uinfo.dqi_flags |= DQF_ROOT_SQUASH;
  	uinfo.dqi_valid = IIF_ALL;

  	if (copy_to_user(addr, &uinfo, sizeof(uinfo)))

  		return -EFAULT;

  	return 0;

  }

  static int quota_setinfo(struct super_block *sb, int type, void __user *addr)
  {
  	struct if_dqinfo info;

  	struct qc_info qinfo;

  	if (copy_from_user(&info, addr, sizeof(info)))
  		return -EFAULT;

  	if (!sb->s_qcop->set_info)
  		return -ENOSYS;

  	if (info.dqi_valid & ~(IIF_FLAGS | IIF_BGRACE | IIF_IGRACE))
  		return -EINVAL;
  	memset(&qinfo, 0, sizeof(qinfo));
  	if (info.dqi_valid & IIF_FLAGS) {
  		if (info.dqi_flags & ~DQF_SETINFO_MASK)
  			return -EINVAL;
  		if (info.dqi_flags & DQF_ROOT_SQUASH)
  			qinfo.i_flags |= QCI_ROOT_SQUASH;
  		qinfo.i_fieldmask |= QC_FLAGS;
  	}
  	if (info.dqi_valid & IIF_BGRACE) {
  		qinfo.i_spc_timelimit = info.dqi_bgrace;
  		qinfo.i_fieldmask |= QC_SPC_TIMER;
  	}
  	if (info.dqi_valid & IIF_IGRACE) {
  		qinfo.i_ino_timelimit = info.dqi_igrace;
  		qinfo.i_fieldmask |= QC_INO_TIMER;
  	}
  	return sb->s_qcop->set_info(sb, type, &qinfo);

  }

  static inline qsize_t qbtos(qsize_t blocks)
  {
  	return blocks << QIF_DQBLKSIZE_BITS;
  }
  
  static inline qsize_t stoqb(qsize_t space)
  {
  	return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS;
  }
  
  static void copy_to_if_dqblk(struct if_dqblk *dst, struct qc_dqblk *src)

  {

  	memset(dst, 0, sizeof(*dst));

  	dst->dqb_bhardlimit = stoqb(src->d_spc_hardlimit);
  	dst->dqb_bsoftlimit = stoqb(src->d_spc_softlimit);
  	dst->dqb_curspace = src->d_space;

  	dst->dqb_ihardlimit = src->d_ino_hardlimit;
  	dst->dqb_isoftlimit = src->d_ino_softlimit;

  	dst->dqb_curinodes = src->d_ino_count;
  	dst->dqb_btime = src->d_spc_timer;
  	dst->dqb_itime = src->d_ino_timer;

  	dst->dqb_valid = QIF_ALL;
  }

  static int quota_getquota(struct super_block *sb, int type, qid_t id,
  			  void __user *addr)
  {

  	struct kqid qid;

  	struct qc_dqblk fdq;

  	struct if_dqblk idq;
  	int ret;

  	if (!sb->s_qcop->get_dqblk)
  		return -ENOSYS;

  	qid = make_kqid(current_user_ns(), type, id);

  	if (!qid_has_mapping(sb->s_user_ns, qid))

  		return -EINVAL;
  	ret = sb->s_qcop->get_dqblk(sb, qid, &fdq);

  	if (ret)
  		return ret;

  	copy_to_if_dqblk(&idq, &fdq);

  
  	if (compat_need_64bit_alignment_fixup()) {
  		struct compat_if_dqblk __user *compat_dqblk = addr;
  
  		if (copy_to_user(compat_dqblk, &idq, sizeof(*compat_dqblk)))
  			return -EFAULT;
  		if (put_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
  			return -EFAULT;
  	} else {
  		if (copy_to_user(addr, &idq, sizeof(idq)))
  			return -EFAULT;
  	}

  	return 0;
  }

  /*
   * Return quota for next active quota >= this id, if any exists,

   * otherwise return -ENOENT via ->get_nextdqblk

   */
  static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
  			  void __user *addr)
  {
  	struct kqid qid;
  	struct qc_dqblk fdq;
  	struct if_nextdqblk idq;
  	int ret;
  
  	if (!sb->s_qcop->get_nextdqblk)
  		return -ENOSYS;
  	qid = make_kqid(current_user_ns(), type, id);

  	if (!qid_has_mapping(sb->s_user_ns, qid))

  		return -EINVAL;
  	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
  	if (ret)
  		return ret;
  	/* struct if_nextdqblk is a superset of struct if_dqblk */
  	copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
  	idq.dqb_id = from_kqid(current_user_ns(), qid);
  	if (copy_to_user(addr, &idq, sizeof(idq)))
  		return -EFAULT;
  	return 0;
  }

  static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)

  {

  	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
  	dst->d_spc_softlimit = qbtos(src->dqb_bsoftlimit);
  	dst->d_space = src->dqb_curspace;

  	dst->d_ino_hardlimit = src->dqb_ihardlimit;
  	dst->d_ino_softlimit = src->dqb_isoftlimit;

  	dst->d_ino_count = src->dqb_curinodes;
  	dst->d_spc_timer = src->dqb_btime;
  	dst->d_ino_timer = src->dqb_itime;

  
  	dst->d_fieldmask = 0;
  	if (src->dqb_valid & QIF_BLIMITS)

  		dst->d_fieldmask |= QC_SPC_SOFT | QC_SPC_HARD;

  	if (src->dqb_valid & QIF_SPACE)

  		dst->d_fieldmask |= QC_SPACE;

  	if (src->dqb_valid & QIF_ILIMITS)

  		dst->d_fieldmask |= QC_INO_SOFT | QC_INO_HARD;

  	if (src->dqb_valid & QIF_INODES)

  		dst->d_fieldmask |= QC_INO_COUNT;

  	if (src->dqb_valid & QIF_BTIME)

  		dst->d_fieldmask |= QC_SPC_TIMER;

  	if (src->dqb_valid & QIF_ITIME)

  		dst->d_fieldmask |= QC_INO_TIMER;

  }

  static int quota_setquota(struct super_block *sb, int type, qid_t id,
  			  void __user *addr)
  {

  	struct qc_dqblk fdq;

  	struct if_dqblk idq;

  	struct kqid qid;

  	if (compat_need_64bit_alignment_fixup()) {
  		struct compat_if_dqblk __user *compat_dqblk = addr;
  
  		if (copy_from_user(&idq, compat_dqblk, sizeof(*compat_dqblk)) ||
  		    get_user(idq.dqb_valid, &compat_dqblk->dqb_valid))
  			return -EFAULT;
  	} else {
  		if (copy_from_user(&idq, addr, sizeof(idq)))
  			return -EFAULT;
  	}

  	if (!sb->s_qcop->set_dqblk)
  		return -ENOSYS;

  	qid = make_kqid(current_user_ns(), type, id);

  	if (!qid_has_mapping(sb->s_user_ns, qid))

  		return -EINVAL;

  	copy_from_if_dqblk(&fdq, &idq);

  	return sb->s_qcop->set_dqblk(sb, qid, &fdq);

  }

  static int quota_enable(struct super_block *sb, void __user *addr)

  {
  	__u32 flags;
  
  	if (copy_from_user(&flags, addr, sizeof(flags)))
  		return -EFAULT;

  	if (!sb->s_qcop->quota_enable)

  		return -ENOSYS;

  	return sb->s_qcop->quota_enable(sb, flags);
  }
  
  static int quota_disable(struct super_block *sb, void __user *addr)
  {
  	__u32 flags;
  
  	if (copy_from_user(&flags, addr, sizeof(flags)))
  		return -EFAULT;
  	if (!sb->s_qcop->quota_disable)
  		return -ENOSYS;
  	return sb->s_qcop->quota_disable(sb, flags);

  }

  static int quota_state_to_flags(struct qc_state *state)
  {
  	int flags = 0;
  
  	if (state->s_state[USRQUOTA].flags & QCI_ACCT_ENABLED)
  		flags |= FS_QUOTA_UDQ_ACCT;
  	if (state->s_state[USRQUOTA].flags & QCI_LIMITS_ENFORCED)
  		flags |= FS_QUOTA_UDQ_ENFD;
  	if (state->s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)
  		flags |= FS_QUOTA_GDQ_ACCT;
  	if (state->s_state[GRPQUOTA].flags & QCI_LIMITS_ENFORCED)
  		flags |= FS_QUOTA_GDQ_ENFD;
  	if (state->s_state[PRJQUOTA].flags & QCI_ACCT_ENABLED)
  		flags |= FS_QUOTA_PDQ_ACCT;
  	if (state->s_state[PRJQUOTA].flags & QCI_LIMITS_ENFORCED)
  		flags |= FS_QUOTA_PDQ_ENFD;
  	return flags;
  }

  static int quota_getstate(struct super_block *sb, int type,
  			  struct fs_quota_stat *fqs)

  {

  	struct qc_state state;
  	int ret;

  	memset(&state, 0, sizeof (struct qc_state));

  	ret = sb->s_qcop->get_state(sb, &state);
  	if (ret < 0)
  		return ret;
  
  	memset(fqs, 0, sizeof(*fqs));
  	fqs->qs_version = FS_QSTAT_VERSION;
  	fqs->qs_flags = quota_state_to_flags(&state);
  	/* No quota enabled? */
  	if (!fqs->qs_flags)
  		return -ENOSYS;
  	fqs->qs_incoredqs = state.s_incoredqs;

  	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
  	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
  	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
  	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
  	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;

  
  	/* Inodes may be allocated even if inactive; copy out if present */
  	if (state.s_state[USRQUOTA].ino) {

  		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
  		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
  		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
  	}

  	if (state.s_state[GRPQUOTA].ino) {

  		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
  		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
  		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
  	}

  	if (state.s_state[PRJQUOTA].ino) {

  		/*
  		 * Q_XGETQSTAT doesn't have room for both group and project
  		 * quotas.  So, allow the project quota values to be copied out
  		 * only if there is no group quota information available.
  		 */
  		if (!(state.s_state[GRPQUOTA].flags & QCI_ACCT_ENABLED)) {
  			fqs->qs_gquota.qfs_ino = state.s_state[PRJQUOTA].ino;
  			fqs->qs_gquota.qfs_nblks =
  					state.s_state[PRJQUOTA].blocks;
  			fqs->qs_gquota.qfs_nextents =
  					state.s_state[PRJQUOTA].nextents;
  		}
  	}
  	return 0;
  }

  static int compat_copy_fs_qfilestat(struct compat_fs_qfilestat __user *to,
  		struct fs_qfilestat *from)
  {
  	if (copy_to_user(to, from, sizeof(*to)) ||
  	    put_user(from->qfs_nextents, &to->qfs_nextents))
  		return -EFAULT;
  	return 0;
  }
  
  static int compat_copy_fs_quota_stat(struct compat_fs_quota_stat __user *to,
  		struct fs_quota_stat *from)
  {
  	if (put_user(from->qs_version, &to->qs_version) ||
  	    put_user(from->qs_flags, &to->qs_flags) ||
  	    put_user(from->qs_pad, &to->qs_pad) ||
  	    compat_copy_fs_qfilestat(&to->qs_uquota, &from->qs_uquota) ||
  	    compat_copy_fs_qfilestat(&to->qs_gquota, &from->qs_gquota) ||
  	    put_user(from->qs_incoredqs, &to->qs_incoredqs) ||
  	    put_user(from->qs_btimelimit, &to->qs_btimelimit) ||
  	    put_user(from->qs_itimelimit, &to->qs_itimelimit) ||
  	    put_user(from->qs_rtbtimelimit, &to->qs_rtbtimelimit) ||
  	    put_user(from->qs_bwarnlimit, &to->qs_bwarnlimit) ||
  	    put_user(from->qs_iwarnlimit, &to->qs_iwarnlimit))
  		return -EFAULT;
  	return 0;
  }

  static int quota_getxstate(struct super_block *sb, int type, void __user *addr)

  {
  	struct fs_quota_stat fqs;
  	int ret;

  	if (!sb->s_qcop->get_state)

  		return -ENOSYS;

  	ret = quota_getstate(sb, type, &fqs);

  	if (ret)
  		return ret;
  
  	if (compat_need_64bit_alignment_fixup())
  		return compat_copy_fs_quota_stat(addr, &fqs);
  	if (copy_to_user(addr, &fqs, sizeof(fqs)))

  		return -EFAULT;

  	return 0;

  }

  static int quota_getstatev(struct super_block *sb, int type,
  			   struct fs_quota_statv *fqs)

  {

  	struct qc_state state;
  	int ret;

  	memset(&state, 0, sizeof (struct qc_state));

  	ret = sb->s_qcop->get_state(sb, &state);
  	if (ret < 0)
  		return ret;
  
  	memset(fqs, 0, sizeof(*fqs));
  	fqs->qs_version = FS_QSTAT_VERSION;
  	fqs->qs_flags = quota_state_to_flags(&state);
  	/* No quota enabled? */
  	if (!fqs->qs_flags)
  		return -ENOSYS;
  	fqs->qs_incoredqs = state.s_incoredqs;

  	fqs->qs_btimelimit = state.s_state[type].spc_timelimit;
  	fqs->qs_itimelimit = state.s_state[type].ino_timelimit;
  	fqs->qs_rtbtimelimit = state.s_state[type].rt_spc_timelimit;
  	fqs->qs_bwarnlimit = state.s_state[type].spc_warnlimit;
  	fqs->qs_iwarnlimit = state.s_state[type].ino_warnlimit;

  
  	/* Inodes may be allocated even if inactive; copy out if present */
  	if (state.s_state[USRQUOTA].ino) {

  		fqs->qs_uquota.qfs_ino = state.s_state[USRQUOTA].ino;
  		fqs->qs_uquota.qfs_nblks = state.s_state[USRQUOTA].blocks;
  		fqs->qs_uquota.qfs_nextents = state.s_state[USRQUOTA].nextents;
  	}

  	if (state.s_state[GRPQUOTA].ino) {

  		fqs->qs_gquota.qfs_ino = state.s_state[GRPQUOTA].ino;
  		fqs->qs_gquota.qfs_nblks = state.s_state[GRPQUOTA].blocks;
  		fqs->qs_gquota.qfs_nextents = state.s_state[GRPQUOTA].nextents;
  	}

  	if (state.s_state[PRJQUOTA].ino) {

  		fqs->qs_pquota.qfs_ino = state.s_state[PRJQUOTA].ino;
  		fqs->qs_pquota.qfs_nblks = state.s_state[PRJQUOTA].blocks;
  		fqs->qs_pquota.qfs_nextents = state.s_state[PRJQUOTA].nextents;
  	}
  	return 0;
  }

  static int quota_getxstatev(struct super_block *sb, int type, void __user *addr)

  {
  	struct fs_quota_statv fqs;
  	int ret;

  	if (!sb->s_qcop->get_state)

  		return -ENOSYS;
  
  	memset(&fqs, 0, sizeof(fqs));
  	if (copy_from_user(&fqs, addr, 1)) /* Just read qs_version */
  		return -EFAULT;
  
  	/* If this kernel doesn't support user specified version, fail */
  	switch (fqs.qs_version) {
  	case FS_QSTATV_VERSION1:
  		break;
  	default:
  		return -EINVAL;
  	}

  	ret = quota_getstatev(sb, type, &fqs);

  	if (!ret && copy_to_user(addr, &fqs, sizeof(fqs)))
  		return -EFAULT;
  	return ret;
  }

  /*
   * XFS defines BBTOB and BTOBB macros inside fs/xfs/ and we cannot move them
   * out of there as xfsprogs rely on definitions being in that header file. So
   * just define same functions here for quota purposes.
   */
  #define XFS_BB_SHIFT 9
  
  static inline u64 quota_bbtob(u64 blocks)
  {
  	return blocks << XFS_BB_SHIFT;
  }
  
  static inline u64 quota_btobb(u64 bytes)
  {
  	return (bytes + (1 << XFS_BB_SHIFT) - 1) >> XFS_BB_SHIFT;
  }

  static inline s64 copy_from_xfs_dqblk_ts(const struct fs_disk_quota *d,
  		__s32 timer, __s8 timer_hi)
  {
  	if (d->d_fieldmask & FS_DQ_BIGTIME)
  		return (u32)timer | (s64)timer_hi << 32;
  	return timer;
  }

  static void copy_from_xfs_dqblk(struct qc_dqblk *dst, struct fs_disk_quota *src)
  {
  	dst->d_spc_hardlimit = quota_bbtob(src->d_blk_hardlimit);
  	dst->d_spc_softlimit = quota_bbtob(src->d_blk_softlimit);
  	dst->d_ino_hardlimit = src->d_ino_hardlimit;
  	dst->d_ino_softlimit = src->d_ino_softlimit;
  	dst->d_space = quota_bbtob(src->d_bcount);
  	dst->d_ino_count = src->d_icount;

  	dst->d_ino_timer = copy_from_xfs_dqblk_ts(src, src->d_itimer,
  						  src->d_itimer_hi);
  	dst->d_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_btimer,
  						  src->d_btimer_hi);

  	dst->d_ino_warns = src->d_iwarns;
  	dst->d_spc_warns = src->d_bwarns;
  	dst->d_rt_spc_hardlimit = quota_bbtob(src->d_rtb_hardlimit);
  	dst->d_rt_spc_softlimit = quota_bbtob(src->d_rtb_softlimit);
  	dst->d_rt_space = quota_bbtob(src->d_rtbcount);

  	dst->d_rt_spc_timer = copy_from_xfs_dqblk_ts(src, src->d_rtbtimer,
  						     src->d_rtbtimer_hi);

  	dst->d_rt_spc_warns = src->d_rtbwarns;
  	dst->d_fieldmask = 0;
  	if (src->d_fieldmask & FS_DQ_ISOFT)
  		dst->d_fieldmask |= QC_INO_SOFT;
  	if (src->d_fieldmask & FS_DQ_IHARD)
  		dst->d_fieldmask |= QC_INO_HARD;
  	if (src->d_fieldmask & FS_DQ_BSOFT)
  		dst->d_fieldmask |= QC_SPC_SOFT;
  	if (src->d_fieldmask & FS_DQ_BHARD)
  		dst->d_fieldmask |= QC_SPC_HARD;
  	if (src->d_fieldmask & FS_DQ_RTBSOFT)
  		dst->d_fieldmask |= QC_RT_SPC_SOFT;
  	if (src->d_fieldmask & FS_DQ_RTBHARD)
  		dst->d_fieldmask |= QC_RT_SPC_HARD;
  	if (src->d_fieldmask & FS_DQ_BTIMER)
  		dst->d_fieldmask |= QC_SPC_TIMER;
  	if (src->d_fieldmask & FS_DQ_ITIMER)
  		dst->d_fieldmask |= QC_INO_TIMER;
  	if (src->d_fieldmask & FS_DQ_RTBTIMER)
  		dst->d_fieldmask |= QC_RT_SPC_TIMER;
  	if (src->d_fieldmask & FS_DQ_BWARNS)
  		dst->d_fieldmask |= QC_SPC_WARNS;
  	if (src->d_fieldmask & FS_DQ_IWARNS)
  		dst->d_fieldmask |= QC_INO_WARNS;
  	if (src->d_fieldmask & FS_DQ_RTBWARNS)
  		dst->d_fieldmask |= QC_RT_SPC_WARNS;
  	if (src->d_fieldmask & FS_DQ_BCOUNT)
  		dst->d_fieldmask |= QC_SPACE;
  	if (src->d_fieldmask & FS_DQ_ICOUNT)
  		dst->d_fieldmask |= QC_INO_COUNT;
  	if (src->d_fieldmask & FS_DQ_RTBCOUNT)
  		dst->d_fieldmask |= QC_RT_SPACE;
  }

  static void copy_qcinfo_from_xfs_dqblk(struct qc_info *dst,
  				       struct fs_disk_quota *src)
  {
  	memset(dst, 0, sizeof(*dst));
  	dst->i_spc_timelimit = src->d_btimer;
  	dst->i_ino_timelimit = src->d_itimer;
  	dst->i_rt_spc_timelimit = src->d_rtbtimer;
  	dst->i_ino_warnlimit = src->d_iwarns;
  	dst->i_spc_warnlimit = src->d_bwarns;
  	dst->i_rt_spc_warnlimit = src->d_rtbwarns;
  	if (src->d_fieldmask & FS_DQ_BWARNS)
  		dst->i_fieldmask |= QC_SPC_WARNS;
  	if (src->d_fieldmask & FS_DQ_IWARNS)
  		dst->i_fieldmask |= QC_INO_WARNS;
  	if (src->d_fieldmask & FS_DQ_RTBWARNS)
  		dst->i_fieldmask |= QC_RT_SPC_WARNS;
  	if (src->d_fieldmask & FS_DQ_BTIMER)
  		dst->i_fieldmask |= QC_SPC_TIMER;
  	if (src->d_fieldmask & FS_DQ_ITIMER)
  		dst->i_fieldmask |= QC_INO_TIMER;
  	if (src->d_fieldmask & FS_DQ_RTBTIMER)
  		dst->i_fieldmask |= QC_RT_SPC_TIMER;
  }

  static int quota_setxquota(struct super_block *sb, int type, qid_t id,
  			   void __user *addr)
  {
  	struct fs_disk_quota fdq;

  	struct qc_dqblk qdq;

  	struct kqid qid;

  
  	if (copy_from_user(&fdq, addr, sizeof(fdq)))
  		return -EFAULT;

  	if (!sb->s_qcop->set_dqblk)

  		return -ENOSYS;

  	qid = make_kqid(current_user_ns(), type, id);

  	if (!qid_has_mapping(sb->s_user_ns, qid))

  		return -EINVAL;

  	/* Are we actually setting timer / warning limits for all users? */

  	if (from_kqid(sb->s_user_ns, qid) == 0 &&

  	    fdq.d_fieldmask & (FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK)) {
  		struct qc_info qinfo;
  		int ret;
  
  		if (!sb->s_qcop->set_info)
  			return -EINVAL;
  		copy_qcinfo_from_xfs_dqblk(&qinfo, &fdq);
  		ret = sb->s_qcop->set_info(sb, type, &qinfo);
  		if (ret)
  			return ret;
  		/* These are already done */
  		fdq.d_fieldmask &= ~(FS_DQ_WARNS_MASK | FS_DQ_TIMER_MASK);
  	}

  	copy_from_xfs_dqblk(&qdq, &fdq);
  	return sb->s_qcop->set_dqblk(sb, qid, &qdq);
  }

  static inline void copy_to_xfs_dqblk_ts(const struct fs_disk_quota *d,
  		__s32 *timer_lo, __s8 *timer_hi, s64 timer)
  {
  	*timer_lo = timer;
  	if (d->d_fieldmask & FS_DQ_BIGTIME)
  		*timer_hi = timer >> 32;
  }
  
  static inline bool want_bigtime(s64 timer)
  {
  	return timer > S32_MAX || timer < S32_MIN;
  }

  static void copy_to_xfs_dqblk(struct fs_disk_quota *dst, struct qc_dqblk *src,
  			      int type, qid_t id)
  {
  	memset(dst, 0, sizeof(*dst));

  	if (want_bigtime(src->d_ino_timer) || want_bigtime(src->d_spc_timer) ||
  	    want_bigtime(src->d_rt_spc_timer))
  		dst->d_fieldmask |= FS_DQ_BIGTIME;

  	dst->d_version = FS_DQUOT_VERSION;
  	dst->d_id = id;
  	if (type == USRQUOTA)
  		dst->d_flags = FS_USER_QUOTA;
  	else if (type == PRJQUOTA)
  		dst->d_flags = FS_PROJ_QUOTA;
  	else
  		dst->d_flags = FS_GROUP_QUOTA;
  	dst->d_blk_hardlimit = quota_btobb(src->d_spc_hardlimit);
  	dst->d_blk_softlimit = quota_btobb(src->d_spc_softlimit);
  	dst->d_ino_hardlimit = src->d_ino_hardlimit;
  	dst->d_ino_softlimit = src->d_ino_softlimit;
  	dst->d_bcount = quota_btobb(src->d_space);
  	dst->d_icount = src->d_ino_count;

  	copy_to_xfs_dqblk_ts(dst, &dst->d_itimer, &dst->d_itimer_hi,
  			     src->d_ino_timer);
  	copy_to_xfs_dqblk_ts(dst, &dst->d_btimer, &dst->d_btimer_hi,
  			     src->d_spc_timer);

  	dst->d_iwarns = src->d_ino_warns;
  	dst->d_bwarns = src->d_spc_warns;
  	dst->d_rtb_hardlimit = quota_btobb(src->d_rt_spc_hardlimit);
  	dst->d_rtb_softlimit = quota_btobb(src->d_rt_spc_softlimit);
  	dst->d_rtbcount = quota_btobb(src->d_rt_space);

  	copy_to_xfs_dqblk_ts(dst, &dst->d_rtbtimer, &dst->d_rtbtimer_hi,
  			     src->d_rt_spc_timer);

  	dst->d_rtbwarns = src->d_rt_spc_warns;

  }
  
  static int quota_getxquota(struct super_block *sb, int type, qid_t id,
  			   void __user *addr)
  {
  	struct fs_disk_quota fdq;

  	struct qc_dqblk qdq;

  	struct kqid qid;

  	int ret;

  	if (!sb->s_qcop->get_dqblk)

  		return -ENOSYS;

  	qid = make_kqid(current_user_ns(), type, id);

  	if (!qid_has_mapping(sb->s_user_ns, qid))

  		return -EINVAL;

  	ret = sb->s_qcop->get_dqblk(sb, qid, &qdq);
  	if (ret)
  		return ret;
  	copy_to_xfs_dqblk(&fdq, &qdq, type, id);
  	if (copy_to_user(addr, &fdq, sizeof(fdq)))

  		return -EFAULT;
  	return ret;
  }

  /*
   * Return quota for next active quota >= this id, if any exists,

   * otherwise return -ENOENT via ->get_nextdqblk.

   */
  static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
  			    void __user *addr)
  {
  	struct fs_disk_quota fdq;
  	struct qc_dqblk qdq;
  	struct kqid qid;
  	qid_t id_out;
  	int ret;
  
  	if (!sb->s_qcop->get_nextdqblk)
  		return -ENOSYS;
  	qid = make_kqid(current_user_ns(), type, id);

  	if (!qid_has_mapping(sb->s_user_ns, qid))

  		return -EINVAL;
  	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
  	if (ret)
  		return ret;
  	id_out = from_kqid(current_user_ns(), qid);
  	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
  	if (copy_to_user(addr, &fdq, sizeof(fdq)))
  		return -EFAULT;
  	return ret;
  }

  static int quota_rmxquota(struct super_block *sb, void __user *addr)
  {
  	__u32 flags;
  
  	if (copy_from_user(&flags, addr, sizeof(flags)))
  		return -EFAULT;
  	if (!sb->s_qcop->rm_xquota)
  		return -ENOSYS;
  	return sb->s_qcop->rm_xquota(sb, flags);
  }

  /* Copy parameters and call proper function */
  static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,

  		       void __user *addr, const struct path *path)

  {

  	int ret;

  	type = array_index_nospec(type, MAXQUOTAS);

  	/*
  	 * Quota not supported on this fs? Check this before s_quota_types
  	 * since they needn't be set if quota is not supported at all.
  	 */

  	if (!sb->s_qcop)
  		return -ENOSYS;

  	if (!(sb->s_quota_types & (1 << type)))
  		return -EINVAL;

  
  	ret = check_quotactl_permission(sb, type, cmd, id);
  	if (ret < 0)
  		return ret;

  	switch (cmd) {
  	case Q_QUOTAON:

  		return quota_quotaon(sb, type, id, path);

  	case Q_QUOTAOFF:

  		return quota_quotaoff(sb, type);

  	case Q_GETFMT:
  		return quota_getfmt(sb, type, addr);
  	case Q_GETINFO:
  		return quota_getinfo(sb, type, addr);
  	case Q_SETINFO:
  		return quota_setinfo(sb, type, addr);
  	case Q_GETQUOTA:
  		return quota_getquota(sb, type, id, addr);

  	case Q_GETNEXTQUOTA:
  		return quota_getnextquota(sb, type, id, addr);

  	case Q_SETQUOTA:
  		return quota_setquota(sb, type, id, addr);
  	case Q_SYNC:

  		if (!sb->s_qcop->quota_sync)
  			return -ENOSYS;

  		return sb->s_qcop->quota_sync(sb, type);

  	case Q_XQUOTAON:

  		return quota_enable(sb, addr);

  	case Q_XQUOTAOFF:

  		return quota_disable(sb, addr);

  	case Q_XQUOTARM:
  		return quota_rmxquota(sb, addr);

  	case Q_XGETQSTAT:

  		return quota_getxstate(sb, type, addr);

  	case Q_XGETQSTATV:

  		return quota_getxstatev(sb, type, addr);

  	case Q_XSETQLIM:
  		return quota_setxquota(sb, type, id, addr);
  	case Q_XGETQUOTA:
  		return quota_getxquota(sb, type, id, addr);

  	case Q_XGETNEXTQUOTA:
  		return quota_getnextxquota(sb, type, id, addr);

  	case Q_XQUOTASYNC:

  		if (sb_rdonly(sb))

  			return -EROFS;

  		/* XFS quotas are fully coherent now, making this call a noop */

  		return 0;

  	default:

  		return -EINVAL;

  	}

  }

  #ifdef CONFIG_BLOCK

  /* Return 1 if 'cmd' will block on frozen filesystem */
  static int quotactl_cmd_write(int cmd)
  {

  	/*
  	 * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
  	 * as dquot_acquire() may allocate space for new structure and OCFS2
  	 * needs to increment on-disk use count.
  	 */

  	switch (cmd) {
  	case Q_GETFMT:
  	case Q_GETINFO:
  	case Q_SYNC:
  	case Q_XGETQSTAT:

  	case Q_XGETQSTATV:

  	case Q_XGETQUOTA:

  	case Q_XGETNEXTQUOTA:

  	case Q_XQUOTASYNC:
  		return 0;
  	}
  	return 1;
  }

  #endif /* CONFIG_BLOCK */

  /* Return true if quotactl command is manipulating quota on/off state */
  static bool quotactl_cmd_onoff(int cmd)
  {

  	return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) ||
  		 (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF);

  }

  /*

   * look up a superblock on which quota ops will be performed
   * - use the name of a block device to find the superblock thereon
   */

  static struct super_block *quotactl_block(const char __user *special, int cmd)

  {
  #ifdef CONFIG_BLOCK
  	struct block_device *bdev;
  	struct super_block *sb;

  	struct filename *tmp = getname(special);

  
  	if (IS_ERR(tmp))

  		return ERR_CAST(tmp);

  	bdev = lookup_bdev(tmp->name);

  	putname(tmp);
  	if (IS_ERR(bdev))

  		return ERR_CAST(bdev);

  	if (quotactl_cmd_onoff(cmd))
  		sb = get_super_exclusive_thawed(bdev);
  	else if (quotactl_cmd_write(cmd))

  		sb = get_super_thawed(bdev);
  	else
  		sb = get_super(bdev);

  	bdput(bdev);
  	if (!sb)
  		return ERR_PTR(-ENODEV);
  
  	return sb;
  #else
  	return ERR_PTR(-ENODEV);
  #endif
  }
  
  /*

   * This is the system call interface. This communicates with
   * the user-level programs. Currently this only supports diskquota
   * calls. Maybe we need to add the process quotas etc. in the future,
   * but we probably should use rlimits for that.
   */

  SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
  		qid_t, id, void __user *, addr)

  {
  	uint cmds, type;
  	struct super_block *sb = NULL;

  	struct path path, *pathp = NULL;

  	int ret;
  
  	cmds = cmd >> SUBCMDSHIFT;
  	type = cmd & SUBCMDMASK;

  	if (type >= MAXQUOTAS)
  		return -EINVAL;

  	/*
  	 * As a special case Q_SYNC can be called without a specific device.
  	 * It will iterate all superblocks that have quota enabled and call
  	 * the sync action on each of them.
  	 */
  	if (!special) {
  		if (cmds == Q_SYNC)
  			return quota_sync_all(type);
  		return -ENODEV;

  	}

  	/*
  	 * Path for quotaon has to be resolved before grabbing superblock
  	 * because that gets s_umount sem which is also possibly needed by path
  	 * resolution (think about autofs) and thus deadlocks could arise.
  	 */
  	if (cmds == Q_QUOTAON) {

  		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);

  		if (ret)
  			pathp = ERR_PTR(ret);
  		else
  			pathp = &path;
  	}

  	sb = quotactl_block(special, cmds);

  	if (IS_ERR(sb)) {
  		ret = PTR_ERR(sb);
  		goto out;
  	}

  	ret = do_quotactl(sb, type, cmds, id, addr, pathp);

  	if (!quotactl_cmd_onoff(cmds))
  		drop_super(sb);
  	else
  		drop_super_exclusive(sb);

  out:

  	if (pathp && !IS_ERR(pathp))
  		path_put(pathp);

  	return ret;
  }