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 9 struct xfs_trans; 10 struct xfs_mount; 11 struct xfs_perag; 12 struct xfs_btree_cur; 13 struct xfs_bmbt_irec; 14 struct xfs_refcount_irec; 15 16 extern int xfs_refcount_lookup_le(struct xfs_btree_cur *cur, 17 enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat); 18 extern int xfs_refcount_lookup_ge(struct xfs_btree_cur *cur, 19 enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat); 20 extern int xfs_refcount_lookup_eq(struct xfs_btree_cur *cur, 21 enum xfs_refc_domain domain, xfs_agblock_t bno, int *stat); 22 extern int xfs_refcount_get_rec(struct xfs_btree_cur *cur, 23 struct xfs_refcount_irec *irec, int *stat); 24 25 static inline uint32_t 26 xfs_refcount_encode_startblock( 27 xfs_agblock_t startblock, 28 enum xfs_refc_domain domain) 29 { 30 uint32_t start; 31 32 /* 33 * low level btree operations need to handle the generic btree range 34 * query functions (which set rc_domain == -1U), so we check that the 35 * domain is /not/ shared. 36 */ 37 start = startblock & ~XFS_REFC_COWFLAG; 38 if (domain != XFS_REFC_DOMAIN_SHARED) 39 start |= XFS_REFC_COWFLAG; 40 41 return start; 42 } 43 44 enum xfs_refcount_intent_type { 45 XFS_REFCOUNT_INCREASE = 1, 46 XFS_REFCOUNT_DECREASE, 47 XFS_REFCOUNT_ALLOC_COW, 48 XFS_REFCOUNT_FREE_COW, 49 }; 50 51 struct xfs_refcount_intent { 52 struct list_head ri_list; 53 enum xfs_refcount_intent_type ri_type; 54 xfs_extlen_t ri_blockcount; 55 xfs_fsblock_t ri_startblock; 56 }; 57 58 /* Check that the refcount is appropriate for the record domain. */ 59 static inline bool 60 xfs_refcount_check_domain( 61 const struct xfs_refcount_irec *irec) 62 { 63 if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1) 64 return false; 65 if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2) 66 return false; 67 return true; 68 } 69 70 void xfs_refcount_increase_extent(struct xfs_trans *tp, 71 struct xfs_bmbt_irec *irec); 72 void xfs_refcount_decrease_extent(struct xfs_trans *tp, 73 struct xfs_bmbt_irec *irec); 74 75 extern void xfs_refcount_finish_one_cleanup(struct xfs_trans *tp, 76 struct xfs_btree_cur *rcur, int error); 77 extern int xfs_refcount_finish_one(struct xfs_trans *tp, 78 struct xfs_refcount_intent *ri, struct xfs_btree_cur **pcur); 79 80 extern int xfs_refcount_find_shared(struct xfs_btree_cur *cur, 81 xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno, 82 xfs_extlen_t *flen, bool find_end_of_shared); 83 84 void xfs_refcount_alloc_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb, 85 xfs_extlen_t len); 86 void xfs_refcount_free_cow_extent(struct xfs_trans *tp, xfs_fsblock_t fsb, 87 xfs_extlen_t len); 88 extern int xfs_refcount_recover_cow_leftovers(struct xfs_mount *mp, 89 struct xfs_perag *pag); 90 91 /* 92 * While we're adjusting the refcounts records of an extent, we have 93 * to keep an eye on the number of extents we're dirtying -- run too 94 * many in a single transaction and we'll exceed the transaction's 95 * reservation and crash the fs. Each record adds 12 bytes to the 96 * log (plus any key updates) so we'll conservatively assume 32 bytes 97 * per record. We must also leave space for btree splits on both ends 98 * of the range and space for the CUD and a new CUI. 99 * 100 * Each EFI that we attach to the transaction is assumed to consume ~32 bytes. 101 * This is a low estimate for an EFI tracking a single extent (16 bytes for the 102 * EFI header, 16 for the extent, and 12 for the xlog op header), but the 103 * estimate is acceptable if there's more than one extent being freed. 104 * In the worst case of freeing every other block during a refcount decrease 105 * operation, we amortize the space used for one EFI log item across 16 106 * extents. 107 */ 108 #define XFS_REFCOUNT_ITEM_OVERHEAD 32 109 110 extern int xfs_refcount_has_record(struct xfs_btree_cur *cur, 111 enum xfs_refc_domain domain, xfs_agblock_t bno, 112 xfs_extlen_t len, bool *exists); 113 union xfs_btree_rec; 114 extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec, 115 struct xfs_refcount_irec *irec); 116 extern int xfs_refcount_insert(struct xfs_btree_cur *cur, 117 struct xfs_refcount_irec *irec, int *stat); 118 119 extern struct kmem_cache *xfs_refcount_intent_cache; 120 121 int __init xfs_refcount_intent_init_cache(void); 122 void xfs_refcount_intent_destroy_cache(void); 123 124 #endif /* __XFS_REFCOUNT_H__ */ 125