text: // SPDX-License-Identifier: GPL-2.0
  /*
   * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
   * All Rights Reserved.
   */
  #ifndef __XFS_TRANS_PRIV_H__
  #define	__XFS_TRANS_PRIV_H__
  
  struct xfs_log_item;
  struct xfs_mount;
  struct xfs_trans;
  struct xfs_ail;
  struct xfs_log_vec;
  
  
  void	xfs_trans_init(struct xfs_mount *);
  void	xfs_trans_add_item(struct xfs_trans *, struct xfs_log_item *);
  void	xfs_trans_del_item(struct xfs_log_item *);
  void	xfs_trans_unreserve_and_mod_sb(struct xfs_trans *tp);
  
  void	xfs_trans_committed_bulk(struct xfs_ail *ailp, struct xfs_log_vec *lv,
  				xfs_lsn_t commit_lsn, bool aborted);
  /*
   * AIL traversal cursor.
   *
   * Rather than using a generation number for detecting changes in the ail, use
   * a cursor that is protected by the ail lock. The aild cursor exists in the
   * struct xfs_ail, but other traversals can declare it on the stack and link it
   * to the ail list.
   *
   * When an object is deleted from or moved int the AIL, the cursor list is
   * searched to see if the object is a designated cursor item. If it is, it is
   * deleted from the cursor so that the next time the cursor is used traversal
   * will return to the start.
   *
   * This means a traversal colliding with a removal will cause a restart of the
   * list scan, rather than any insertion or deletion anywhere in the list. The
   * low bit of the item pointer is set if the cursor has been invalidated so
   * that we can tell the difference between invalidation and reaching the end
   * of the list to trigger traversal restarts.
   */
  struct xfs_ail_cursor {
  	struct list_head	list;
  	struct xfs_log_item	*item;
  };
  
  /*
   * Private AIL structures.
   *
   * Eventually we need to drive the locking in here as well.
   */
  struct xfs_ail {
  	struct xfs_mount	*ail_mount;
  	struct task_struct	*ail_task;
  	struct list_head	ail_head;
  	xfs_lsn_t		ail_target;
  	xfs_lsn_t		ail_target_prev;
  	struct list_head	ail_cursors;
  	spinlock_t		ail_lock;
  	xfs_lsn_t		ail_last_pushed_lsn;
  	int			ail_log_flush;
  	struct list_head	ail_buf_list;
  	wait_queue_head_t	ail_empty;
  };
  
  /*
   * From xfs_trans_ail.c
   */
  void	xfs_trans_ail_update_bulk(struct xfs_ail *ailp,
  				struct xfs_ail_cursor *cur,
  				struct xfs_log_item **log_items, int nr_items,
  				xfs_lsn_t lsn) __releases(ailp->ail_lock);
  /*
   * Return a pointer to the first item in the AIL.  If the AIL is empty, then
   * return NULL.
   */
  static inline struct xfs_log_item *
  xfs_ail_min(
  	struct xfs_ail  *ailp)
  {
  	return list_first_entry_or_null(&ailp->ail_head, struct xfs_log_item,
  					li_ail);
  }
  
  static inline void
  xfs_trans_ail_update(
  	struct xfs_ail		*ailp,
  	struct xfs_log_item	*lip,
  	xfs_lsn_t		lsn) __releases(ailp->ail_lock)
  {
  	xfs_trans_ail_update_bulk(ailp, NULL, &lip, 1, lsn);
  }
  
  xfs_lsn_t xfs_ail_delete_one(struct xfs_ail *ailp, struct xfs_log_item *lip);
  void xfs_ail_update_finish(struct xfs_ail *ailp, xfs_lsn_t old_lsn)
  			__releases(ailp->ail_lock);
  void xfs_trans_ail_delete(struct xfs_ail *ailp, struct xfs_log_item *lip,
  		int shutdown_type);
  
  static inline void
  xfs_trans_ail_remove(
  	struct xfs_log_item	*lip,
  	int			shutdown_type)
  {
  	struct xfs_ail		*ailp = lip->li_ailp;
  
  	spin_lock(&ailp->ail_lock);
  	/* xfs_trans_ail_delete() drops the AIL lock */
  	if (test_bit(XFS_LI_IN_AIL, &lip->li_flags))
  		xfs_trans_ail_delete(ailp, lip, shutdown_type);
  	else
  		spin_unlock(&ailp->ail_lock);
  }
  
  void			xfs_ail_push(struct xfs_ail *, xfs_lsn_t);
  void			xfs_ail_push_all(struct xfs_ail *);
  void			xfs_ail_push_all_sync(struct xfs_ail *);
  struct xfs_log_item	*xfs_ail_min(struct xfs_ail  *ailp);
  xfs_lsn_t		xfs_ail_min_lsn(struct xfs_ail *ailp);
  
  struct xfs_log_item *	xfs_trans_ail_cursor_first(struct xfs_ail *ailp,
  					struct xfs_ail_cursor *cur,
  					xfs_lsn_t lsn);
  struct xfs_log_item *	xfs_trans_ail_cursor_last(struct xfs_ail *ailp,
  					struct xfs_ail_cursor *cur,
  					xfs_lsn_t lsn);
  struct xfs_log_item *	xfs_trans_ail_cursor_next(struct xfs_ail *ailp,
  					struct xfs_ail_cursor *cur);
  void			xfs_trans_ail_cursor_done(struct xfs_ail_cursor *cur);
  
  #if BITS_PER_LONG != 64
  static inline void
  xfs_trans_ail_copy_lsn(
  	struct xfs_ail	*ailp,
  	xfs_lsn_t	*dst,
  	xfs_lsn_t	*src)
  {
  	ASSERT(sizeof(xfs_lsn_t) == 8);	/* don't lock if it shrinks */
  	spin_lock(&ailp->ail_lock);
  	*dst = *src;
  	spin_unlock(&ailp->ail_lock);
  }
  #else
  static inline void
  xfs_trans_ail_copy_lsn(
  	struct xfs_ail	*ailp,
  	xfs_lsn_t	*dst,
  	xfs_lsn_t	*src)
  {
  	ASSERT(sizeof(xfs_lsn_t) == 8);
  	*dst = *src;
  }
  #endif
  
  static inline void
  xfs_clear_li_failed(
  	struct xfs_log_item	*lip)
  {
  	struct xfs_buf	*bp = lip->li_buf;
  
  	ASSERT(test_bit(XFS_LI_IN_AIL, &lip->li_flags));
  	lockdep_assert_held(&lip->li_ailp->ail_lock);
  
  	if (test_and_clear_bit(XFS_LI_FAILED, &lip->li_flags)) {
  		lip->li_buf = NULL;
  		xfs_buf_rele(bp);
  	}
  }
  
  static inline void
  xfs_set_li_failed(
  	struct xfs_log_item	*lip,
  	struct xfs_buf		*bp)
  {
  	lockdep_assert_held(&lip->li_ailp->ail_lock);
  
  	if (!test_and_set_bit(XFS_LI_FAILED, &lip->li_flags)) {
  		xfs_buf_hold(bp);
  		lip->li_buf = bp;
  	}
  }
  
  #endif	/* __XFS_TRANS_PRIV_H__ */
  