// SPDX-License-Identifier: GPL-2.0

  /*

   * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   * All Rights Reserved.

   */
  #ifndef __XFS_DQUOT_H__
  #define __XFS_DQUOT_H__
  
  /*
   * Dquots are structures that hold quota information about a user or a group,
   * much like inodes are for files. In fact, dquots share many characteristics
   * with inodes. However, dquots can also be a centralized resource, relative
   * to a collection of inodes. In this respect, dquots share some characteristics
   * of the superblock.
   * XFS dquots exploit both those in its algorithms. They make every attempt
   * to not be a bottleneck when quotas are on and have minimal impact, if any,
   * when quotas are off.
   */

  struct xfs_mount;
  struct xfs_trans;

  enum {
  	XFS_QLOWSP_1_PCNT = 0,
  	XFS_QLOWSP_3_PCNT,
  	XFS_QLOWSP_5_PCNT,
  	XFS_QLOWSP_MAX
  };

  struct xfs_dquot_res {
  	/* Total resources allocated and reserved. */
  	xfs_qcnt_t		reserved;

  	/* Total resources allocated. */
  	xfs_qcnt_t		count;

  	/* Absolute and preferred limits. */
  	xfs_qcnt_t		hardlimit;
  	xfs_qcnt_t		softlimit;

  
  	/*

  	 * For root dquots, this is the default grace period, in seconds.
  	 * Otherwise, this is when the quota grace period expires,
  	 * in seconds since the Unix epoch.
  	 */
  	time64_t		timer;
  
  	/*

  	 * For root dquots, this is the maximum number of warnings that will
  	 * be issued for this quota type.  Otherwise, this is the number of
  	 * warnings issued against this quota.  Note that none of this is
  	 * implemented.
  	 */
  	xfs_qwarncnt_t		warnings;

  };

  /*

   * The incore dquot structure
   */

  struct xfs_dquot {

  	struct list_head	q_lru;
  	struct xfs_mount	*q_mount;

  	xfs_dqtype_t		q_type;

  	uint16_t		q_flags;

  	xfs_dqid_t		q_id;

  	uint			q_nrefs;

  	int			q_bufoffset;

  	xfs_daddr_t		q_blkno;

  	xfs_fileoff_t		q_fileoffset;

  	struct xfs_dquot_res	q_blk;	/* regular blocks */
  	struct xfs_dquot_res	q_ino;	/* inodes */
  	struct xfs_dquot_res	q_rtb;	/* realtime blocks */

  	struct xfs_dq_logitem	q_logitem;

  	xfs_qcnt_t		q_prealloc_lo_wmark;
  	xfs_qcnt_t		q_prealloc_hi_wmark;
  	int64_t			q_low_space[XFS_QLOWSP_MAX];
  	struct mutex		q_qlock;
  	struct completion	q_flush;
  	atomic_t		q_pincount;
  	struct wait_queue_head	q_pinwait;
  };

  /*

   * Lock hierarchy for q_qlock:

   *	XFS_QLOCK_NORMAL is the implicit default,

   *	XFS_QLOCK_NESTED is the dquot with the higher id in xfs_dqlock2

   */
  enum {
  	XFS_QLOCK_NORMAL = 0,
  	XFS_QLOCK_NESTED,
  };

  /*

   * Manage the q_flush completion queue embedded in the dquot. This completion

   * queue synchronizes processes attempting to flush the in-core dquot back to
   * disk.

   */

  static inline void xfs_dqflock(struct xfs_dquot *dqp)

  {
  	wait_for_completion(&dqp->q_flush);
  }

  static inline bool xfs_dqflock_nowait(struct xfs_dquot *dqp)

  {
  	return try_wait_for_completion(&dqp->q_flush);
  }

  static inline void xfs_dqfunlock(struct xfs_dquot *dqp)

  {
  	complete(&dqp->q_flush);
  }

  static inline int xfs_dqlock_nowait(struct xfs_dquot *dqp)
  {
  	return mutex_trylock(&dqp->q_qlock);
  }
  
  static inline void xfs_dqlock(struct xfs_dquot *dqp)
  {
  	mutex_lock(&dqp->q_qlock);
  }

  static inline void xfs_dqunlock(struct xfs_dquot *dqp)

  {
  	mutex_unlock(&dqp->q_qlock);
  }

  static inline int
  xfs_dquot_type(const struct xfs_dquot *dqp)
  {

  	return dqp->q_type & XFS_DQTYPE_REC_MASK;

  }

  static inline int xfs_this_quota_on(struct xfs_mount *mp, xfs_dqtype_t type)

  {

  	switch (type) {

  	case XFS_DQTYPE_USER:

  		return XFS_IS_UQUOTA_ON(mp);

  	case XFS_DQTYPE_GROUP:

  		return XFS_IS_GQUOTA_ON(mp);

  	case XFS_DQTYPE_PROJ:

  		return XFS_IS_PQUOTA_ON(mp);

  	default:
  		return 0;
  	}
  }

  static inline struct xfs_dquot *xfs_inode_dquot(
  	struct xfs_inode	*ip,
  	xfs_dqtype_t		type)

  {

  	switch (type) {

  	case XFS_DQTYPE_USER:

  		return ip->i_udquot;

  	case XFS_DQTYPE_GROUP:

  		return ip->i_gdquot;

  	case XFS_DQTYPE_PROJ:

  		return ip->i_pdquot;

  	default:
  		return NULL;
  	}
  }

  /* Decide if the dquot's limits are actually being enforced. */
  static inline bool
  xfs_dquot_is_enforced(
  	const struct xfs_dquot	*dqp)
  {

  	switch (xfs_dquot_type(dqp)) {

  	case XFS_DQTYPE_USER:
  		return XFS_IS_UQUOTA_ENFORCED(dqp->q_mount);
  	case XFS_DQTYPE_GROUP:
  		return XFS_IS_GQUOTA_ENFORCED(dqp->q_mount);
  	case XFS_DQTYPE_PROJ:
  		return XFS_IS_PQUOTA_ENFORCED(dqp->q_mount);
  	}
  	ASSERT(0);
  	return false;
  }

  /*
   * Check whether a dquot is under low free space conditions. We assume the quota
   * is enabled and enforced.
   */
  static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
  {
  	int64_t freesp;

  	freesp = dqp->q_blk.hardlimit - dqp->q_blk.reserved;

  	if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
  		return true;
  
  	return false;
  }

  void xfs_dquot_to_disk(struct xfs_disk_dquot *ddqp, struct xfs_dquot *dqp);

  #define XFS_DQ_IS_LOCKED(dqp)	(mutex_is_locked(&((dqp)->q_qlock)))

  #define XFS_DQ_IS_DIRTY(dqp)	((dqp)->q_flags & XFS_DQFLAG_DIRTY)

  void		xfs_qm_dqdestroy(struct xfs_dquot *dqp);
  int		xfs_qm_dqflush(struct xfs_dquot *dqp, struct xfs_buf **bpp);
  void		xfs_qm_dqunpin_wait(struct xfs_dquot *dqp);

  void		xfs_qm_adjust_dqtimers(struct xfs_dquot *d);
  void		xfs_qm_adjust_dqlimits(struct xfs_dquot *d);
  xfs_dqid_t	xfs_qm_id_for_quotatype(struct xfs_inode *ip,

  				xfs_dqtype_t type);

  int		xfs_qm_dqget(struct xfs_mount *mp, xfs_dqid_t id,

  				xfs_dqtype_t type, bool can_alloc,
  				struct xfs_dquot **dqpp);
  int		xfs_qm_dqget_inode(struct xfs_inode *ip, xfs_dqtype_t type,
  				bool can_alloc, struct xfs_dquot **dqpp);

  int		xfs_qm_dqget_next(struct xfs_mount *mp, xfs_dqid_t id,

  				xfs_dqtype_t type, struct xfs_dquot **dqpp);

  int		xfs_qm_dqget_uncached(struct xfs_mount *mp,

  				xfs_dqid_t id, xfs_dqtype_t type,
  				struct xfs_dquot **dqpp);

  void		xfs_qm_dqput(struct xfs_dquot *dqp);

  void		xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);

  void		xfs_dquot_set_prealloc_limits(struct xfs_dquot *);

  static inline struct xfs_dquot *xfs_qm_dqhold(struct xfs_dquot *dqp)
  {
  	xfs_dqlock(dqp);
  	dqp->q_nrefs++;
  	xfs_dqunlock(dqp);
  	return dqp;
  }

  typedef int (*xfs_qm_dqiterate_fn)(struct xfs_dquot *dq,
  		xfs_dqtype_t type, void *priv);
  int xfs_qm_dqiterate(struct xfs_mount *mp, xfs_dqtype_t type,

  		xfs_qm_dqiterate_fn iter_fn, void *priv);

  time64_t xfs_dquot_set_timeout(struct xfs_mount *mp, time64_t timeout);

  time64_t xfs_dquot_set_grace_period(time64_t grace);

  #endif /* __XFS_DQUOT_H__ */