linux/fs/xfs/libxfs/xfs_refcount.h

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2016 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <[email protected]>
 */
#ifndef __XFS_REFCOUNT_H__
#define __XFS_REFCOUNT_H__

struct xfs_trans;
struct xfs_mount;
struct xfs_perag;
struct xfs_btree_cur;
struct xfs_bmbt_irec;
struct xfs_refcount_irec;

extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
		enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
		enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
extern int xfs_refcount_lookup_eq(struct xfs_btree_cur *cur,
		enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
		struct xfs_refcount_irec *irec, int *stat);

static inline uint32_t
xfs_refcount_encode_startblock(
	xfs_agblock_t		startblock,
	enum xfs_refc_domain	domain)
{ … }

enum xfs_refcount_intent_type { … };

#define XFS_REFCOUNT_INTENT_STRINGS …

struct xfs_refcount_intent { … };

/* Check that the refcount is appropriate for the record domain. */
static inline bool
xfs_refcount_check_domain(
	const struct xfs_refcount_irec	*irec)
{ … }

void xfs_refcount_increase_extent(struct xfs_trans *tp,
		struct xfs_bmbt_irec *irec);
void xfs_refcount_decrease_extent(struct xfs_trans *tp,
		struct xfs_bmbt_irec *irec);

extern int xfs_refcount_finish_one(struct xfs_trans *tp,
		struct xfs_refcount_intent *ri, struct xfs_btree_cur **pcur);

extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
		xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
		xfs_extlen_t *flen, bool find_end_of_shared);

void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
		xfs_extlen_t len);
void xfs_refcount_free_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb,
		xfs_extlen_t len);
extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp,
		struct xfs_perag *pag);

/*
 * While we're adjusting the refcounts records of an extent, we have
 * to keep an eye on the number of extents we're dirtying -- run too
 * many in a single transaction and we'll exceed the transaction's
 * reservation and crash the fs.  Each record adds 12 bytes to the
 * log (plus any key updates) so we'll conservatively assume 32 bytes
 * per record.  We must also leave space for btree splits on both ends
 * of the range and space for the CUD and a new CUI.
 *
 * Each EFI that we attach to the transaction is assumed to consume ~32 bytes.
 * This is a low estimate for an EFI tracking a single extent (16 bytes for the
 * EFI header, 16 for the extent, and 12 for the xlog op header), but the
 * estimate is acceptable if there's more than one extent being freed.
 * In the worst case of freeing every other block during a refcount decrease
 * operation, we amortize the space used for one EFI log item across 16
 * extents.
 */
#define XFS_REFCOUNT_ITEM_OVERHEAD …

extern int xfs_refcount_has_records(struct xfs_btree_cur *cur,
		enum xfs_refc_domain domain, xfs_agblock_t bno,
		xfs_extlen_t len, enum xbtree_recpacking *outcome);
xfs_btree_rec;
extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec,
		struct xfs_refcount_irec *irec);
xfs_failaddr_t xfs_refcount_check_irec(struct xfs_perag *pag,
		const struct xfs_refcount_irec *irec);
extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
		struct xfs_refcount_irec *irec, int *stat);

extern struct kmem_cache	*xfs_refcount_intent_cache;

int __init xfs_refcount_intent_init_cache(void);
void xfs_refcount_intent_destroy_cache(void);

xfs_refcount_query_range_fn;

int xfs_refcount_query_range(struct xfs_btree_cur *cur,
		const struct xfs_refcount_irec *low_rec,
		const struct xfs_refcount_irec *high_rec,
		xfs_refcount_query_range_fn fn, void *priv);

#endif	/* __XFS_REFCOUNT_H__ */