diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_refcount.h')
-rw-r--r-- | fs/xfs/libxfs/xfs_refcount.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_refcount.h b/fs/xfs/libxfs/xfs_refcount.h new file mode 100644 index 0000000000..783cd89ca1 --- /dev/null +++ b/fs/xfs/libxfs/xfs_refcount.h @@ -0,0 +1,130 @@ +// 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; + struct xfs_perag *ri_pag; + 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_update_get_group(struct xfs_mount *mp, + struct xfs_refcount_intent *ri); + +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, + 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 32 + +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); +union 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_btree_cur *cur, + 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); + +#endif /* __XFS_REFCOUNT_H__ */ |