fs/xfs/libxfs/xfs_defer.h

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2016 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 */
#ifndef __XFS_DEFER_H__
#define	__XFS_DEFER_H__

struct xfs_defer_op_type;
struct xfs_defer_capture;

/*
 * Header for deferred operation list.
 */
enum xfs_defer_ops_type {
	XFS_DEFER_OPS_TYPE_BMAP,
	XFS_DEFER_OPS_TYPE_REFCOUNT,
	XFS_DEFER_OPS_TYPE_RMAP,
	XFS_DEFER_OPS_TYPE_FREE,
	XFS_DEFER_OPS_TYPE_AGFL_FREE,
	XFS_DEFER_OPS_TYPE_MAX,
};

/*
 * Save a log intent item and a list of extents, so that we can replay
 * whatever action had to happen to the extent list and file the log done
 * item.
 */
struct xfs_defer_pending {
	struct list_head		dfp_list;	/* pending items */
	struct list_head		dfp_work;	/* work items */
	struct xfs_log_item		*dfp_intent;	/* log intent item */
	void				*dfp_done;	/* log done item */
	unsigned int			dfp_count;	/* # extent items */
	enum xfs_defer_ops_type		dfp_type;
};

void xfs_defer_add(struct xfs_trans *tp, enum xfs_defer_ops_type type,
		struct list_head *h);
int xfs_defer_finish_noroll(struct xfs_trans **tp);
int xfs_defer_finish(struct xfs_trans **tp);
void xfs_defer_cancel(struct xfs_trans *);
void xfs_defer_move(struct xfs_trans *dtp, struct xfs_trans *stp);

/* Description of a deferred type. */
struct xfs_defer_op_type {
	struct xfs_log_item *(*create_intent)(struct xfs_trans *tp,
			struct list_head *items, unsigned int count, bool sort);
	void (*abort_intent)(struct xfs_log_item *intent);
	void *(*create_done)(struct xfs_trans *tp, struct xfs_log_item *intent,
			unsigned int count);
	int (*finish_item)(struct xfs_trans *, struct list_head *, void *,
			void **);
	void (*finish_cleanup)(struct xfs_trans *, void *, int);
	void (*cancel_item)(struct list_head *);
	unsigned int		max_items;
};

extern const struct xfs_defer_op_type xfs_bmap_update_defer_type;
extern const struct xfs_defer_op_type xfs_refcount_update_defer_type;
extern const struct xfs_defer_op_type xfs_rmap_update_defer_type;
extern const struct xfs_defer_op_type xfs_extent_free_defer_type;
extern const struct xfs_defer_op_type xfs_agfl_free_defer_type;

/*
 * This structure enables a dfops user to detach the chain of deferred
 * operations from a transaction so that they can be continued later.
 */
struct xfs_defer_capture {
	/* List of other capture structures. */
	struct list_head	dfc_list;

	/* Deferred ops state saved from the transaction. */
	struct list_head	dfc_dfops;
	unsigned int		dfc_tpflags;

	/* Block reservations for the data and rt devices. */
	unsigned int		dfc_blkres;
	unsigned int		dfc_rtxres;

	/* Log reservation saved from the transaction. */
	unsigned int		dfc_logres;

	/*
	 * An inode reference that must be maintained to complete the deferred
	 * work.
	 */
	struct xfs_inode	*dfc_capture_ip;
};

/*
 * Functions to capture a chain of deferred operations and continue them later.
 * This doesn't normally happen except log recovery.
 */
int xfs_defer_ops_capture_and_commit(struct xfs_trans *tp,
		struct xfs_inode *capture_ip, struct list_head *capture_list);
void xfs_defer_ops_continue(struct xfs_defer_capture *d, struct xfs_trans *tp,
		struct xfs_inode **captured_ipp);
void xfs_defer_ops_release(struct xfs_mount *mp, struct xfs_defer_capture *d);

#endif /* __XFS_DEFER_H__ */