xfs_refcount.h

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright (C) 2016 Oracle.  All Rights Reserved.
  4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
  5 */
  6#ifndef __XFS_REFCOUNT_H__
  7#define __XFS_REFCOUNT_H__
  8
  9struct xfs_trans;
 10struct xfs_mount;
 11struct xfs_perag;
 12struct xfs_btree_cur;
 13struct xfs_bmbt_irec;
 14struct xfs_refcount_irec;
 15struct xfs_rtgroup;
 16
 17extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur,
 18		enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
 19extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur,
 20		enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
 21extern int xfs_refcount_lookup_eq(struct xfs_btree_cur *cur,
 22		enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat);
 23extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur,
 24		struct xfs_refcount_irec *irec, int *stat);
 25
 26static inline uint32_t
 27xfs_refcount_encode_startblock(
 28	xfs_agblock_t		startblock,
 29	enum xfs_refc_domain	domain)
 30{
 31	uint32_t		start;
 32
 33	/*
 34	 * low level btree operations need to handle the generic btree range
 35	 * query functions (which set rc_domain == -1U), so we check that the
 36	 * domain is /not/ shared.
 37	 */
 38	start = startblock & ~XFS_REFC_COWFLAG;
 39	if (domain != XFS_REFC_DOMAIN_SHARED)
 40		start |= XFS_REFC_COWFLAG;
 41
 42	return start;
 43}
 44
 45enum xfs_refcount_intent_type {
 46	XFS_REFCOUNT_INCREASE = 1,
 47	XFS_REFCOUNT_DECREASE,
 48	XFS_REFCOUNT_ALLOC_COW,
 49	XFS_REFCOUNT_FREE_COW,
 50};
 51
 52#define XFS_REFCOUNT_INTENT_STRINGS \
 53	{ XFS_REFCOUNT_INCREASE,	"incr" }, \
 54	{ XFS_REFCOUNT_DECREASE,	"decr" }, \
 55	{ XFS_REFCOUNT_ALLOC_COW,	"alloc_cow" }, \
 56	{ XFS_REFCOUNT_FREE_COW,	"free_cow" }
 57
 58struct xfs_refcount_intent {
 59	struct list_head			ri_list;
 60	struct xfs_group			*ri_group;
 61	enum xfs_refcount_intent_type		ri_type;
 62	xfs_extlen_t				ri_blockcount;
 63	xfs_fsblock_t				ri_startblock;
 64	bool					ri_realtime;
 65};
 66
 67/* Check that the refcount is appropriate for the record domain. */
 68static inline bool
 69xfs_refcount_check_domain(
 70	const struct xfs_refcount_irec	*irec)
 71{
 72	if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1)
 73		return false;
 74	if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2)
 75		return false;
 76	return true;
 77}
 78
 79void xfs_refcount_increase_extent(struct xfs_trans *tp, bool isrt,
 80		struct xfs_bmbt_irec *irec);
 81void xfs_refcount_decrease_extent(struct xfs_trans *tp, bool isrt,
 82		struct xfs_bmbt_irec *irec);
 83
 84int xfs_refcount_finish_one(struct xfs_trans *tp,
 85		struct xfs_refcount_intent *ri, struct xfs_btree_cur **pcur);
 86int xfs_rtrefcount_finish_one(struct xfs_trans *tp,
 87		struct xfs_refcount_intent *ri, struct xfs_btree_cur **pcur);
 88
 89extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur,
 90		xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
 91		xfs_extlen_t *flen, bool find_end_of_shared);
 92
 93void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, bool isrt,
 94		xfs_fsblock_t fsb, xfs_extlen_t len);
 95void xfs_refcount_free_cow_extent(struct xfs_trans *tp, bool isrt,
 96		xfs_fsblock_t fsb, xfs_extlen_t len);
 97int xfs_refcount_recover_cow_leftovers(struct xfs_group *xg);
 98
 99/*
100 * While we're adjusting the refcounts records of an extent, we have
101 * to keep an eye on the number of extents we're dirtying -- run too
102 * many in a single transaction and we'll exceed the transaction's
103 * reservation and crash the fs.  Each record adds 12 bytes to the
104 * log (plus any key updates) so we'll conservatively assume 32 bytes
105 * per record.  We must also leave space for btree splits on both ends
106 * of the range and space for the CUD and a new CUI.
107 *
108 * Each EFI that we attach to the transaction is assumed to consume ~32 bytes.
109 * This is a low estimate for an EFI tracking a single extent (16 bytes for the
110 * EFI header, 16 for the extent, and 12 for the xlog op header), but the
111 * estimate is acceptable if there's more than one extent being freed.
112 * In the worst case of freeing every other block during a refcount decrease
113 * operation, we amortize the space used for one EFI log item across 16
114 * extents.
115 */
116#define XFS_REFCOUNT_ITEM_OVERHEAD	32
117
118extern int xfs_refcount_has_records(struct xfs_btree_cur *cur,
119		enum xfs_refc_domain domain, xfs_agblock_t bno,
120		xfs_extlen_t len, enum xbtree_recpacking *outcome);
121union xfs_btree_rec;
122extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec,
123		struct xfs_refcount_irec *irec);
124xfs_failaddr_t xfs_refcount_check_irec(struct xfs_perag *pag,
125		const struct xfs_refcount_irec *irec);
126xfs_failaddr_t xfs_rtrefcount_check_irec(struct xfs_rtgroup *rtg,
127		const struct xfs_refcount_irec *irec);
128extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
129		struct xfs_refcount_irec *irec, int *stat);
130
131extern struct kmem_cache	*xfs_refcount_intent_cache;
132
133int __init xfs_refcount_intent_init_cache(void);
134void xfs_refcount_intent_destroy_cache(void);
135
136typedef int (*xfs_refcount_query_range_fn)(
137	struct xfs_btree_cur		*cur,
138	const struct xfs_refcount_irec	*rec,
139	void				*priv);
140
141int xfs_refcount_query_range(struct xfs_btree_cur *cur,
142		const struct xfs_refcount_irec *low_rec,
143		const struct xfs_refcount_irec *high_rec,
144		xfs_refcount_query_range_fn fn, void *priv);
145
146#endif	/* __XFS_REFCOUNT_H__ */