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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*/
#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)
{
uint32_t start;
/*
* low level btree operations need to handle the generic btree range
* query functions (which set rc_domain == -1U), so we check that the
* domain is /not/ shared.
*/
start = startblock & ~XFS_REFC_COWFLAG;
if (domain != XFS_REFC_DOMAIN_SHARED)
start |= XFS_REFC_COWFLAG;
return start;
}
enum xfs_refcount_intent_type {
XFS_REFCOUNT_INCREASE = 1,
XFS_REFCOUNT_DECREASE,
XFS_REFCOUNT_ALLOC_COW,
XFS_REFCOUNT_FREE_COW,
};
struct xfs_refcount_intent {
struct list_head ri_list;
enum xfs_refcount_intent_type ri_type;
xfs_extlen_t ri_blockcount;
xfs_fsblock_t ri_startblock;
};
/* Check that the refcount is appropriate for the record domain. */
static inline bool
xfs_refcount_check_domain(
const struct xfs_refcount_irec *irec)
{
if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1)
return false;
if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2)
return false;
return true;
}
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 void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp,
struct xfs_btree_cur *rcur, int error);
extern int xfs_refcount_finish_one(struct xfs_trans *tp,
enum xfs_refcount_intent_type type, xfs_fsblock_t startblock,
xfs_extlen_t blockcount, xfs_fsblock_t *new_fsb,
xfs_extlen_t *new_len, 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 32
extern int xfs_refcount_has_record(struct xfs_btree_cur *cur,
enum xfs_refc_domain domain, xfs_agblock_t bno,
xfs_extlen_t len, bool *exists);
union xfs_btree_rec;
extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec,
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);
#endif /* __XFS_REFCOUNT_H__ */
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