xref: /linux/fs/xfs/libxfs/xfs_btree_staging.h (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright (C) 2020 Oracle.  All Rights Reserved.
4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
5  */
6 #ifndef __XFS_BTREE_STAGING_H__
7 #define __XFS_BTREE_STAGING_H__
8 
9 /* Fake root for an AG-rooted btree. */
10 struct xbtree_afakeroot {
11 	/* AG block number of the new btree root. */
12 	xfs_agblock_t		af_root;
13 
14 	/* Height of the new btree. */
15 	unsigned int		af_levels;
16 
17 	/* Number of blocks used by the btree. */
18 	unsigned int		af_blocks;
19 };
20 
21 /* Cursor interactions with fake roots for AG-rooted btrees. */
22 void xfs_btree_stage_afakeroot(struct xfs_btree_cur *cur,
23 		struct xbtree_afakeroot *afake);
24 void xfs_btree_commit_afakeroot(struct xfs_btree_cur *cur, struct xfs_trans *tp,
25 		struct xfs_buf *agbp);
26 
27 /* Fake root for an inode-rooted btree. */
28 struct xbtree_ifakeroot {
29 	/* Fake inode fork. */
30 	struct xfs_ifork	*if_fork;
31 
32 	/* Number of blocks used by the btree. */
33 	int64_t			if_blocks;
34 
35 	/* Height of the new btree. */
36 	unsigned int		if_levels;
37 
38 	/* Number of bytes available for this fork in the inode. */
39 	unsigned int		if_fork_size;
40 };
41 
42 /* Cursor interactions with fake roots for inode-rooted btrees. */
43 void xfs_btree_stage_ifakeroot(struct xfs_btree_cur *cur,
44 		struct xbtree_ifakeroot *ifake);
45 void xfs_btree_commit_ifakeroot(struct xfs_btree_cur *cur, struct xfs_trans *tp,
46 		int whichfork);
47 
48 /* Bulk loading of staged btrees. */
49 typedef int (*xfs_btree_bload_get_records_fn)(struct xfs_btree_cur *cur,
50 		unsigned int idx, struct xfs_btree_block *block,
51 		unsigned int nr_wanted, void *priv);
52 typedef int (*xfs_btree_bload_claim_block_fn)(struct xfs_btree_cur *cur,
53 		union xfs_btree_ptr *ptr, void *priv);
54 typedef size_t (*xfs_btree_bload_iroot_size_fn)(struct xfs_btree_cur *cur,
55 		unsigned int level, unsigned int nr_this_level, void *priv);
56 
57 struct xfs_btree_bload {
58 	/*
59 	 * This function will be called to load @nr_wanted records into the
60 	 * btree.  The implementation does this by setting the cursor's bc_rec
61 	 * field in in-core format and using init_rec_from_cur to set the
62 	 * records in the btree block.  Records must be returned in sort order.
63 	 * The function must return the number of records loaded or the usual
64 	 * negative errno.
65 	 */
66 	xfs_btree_bload_get_records_fn	get_records;
67 
68 	/*
69 	 * This function will be called nr_blocks times to obtain a pointer
70 	 * to a new btree block on disk.  Callers must preallocate all space
71 	 * for the new btree before calling xfs_btree_bload, and this function
72 	 * is what claims that reservation.
73 	 */
74 	xfs_btree_bload_claim_block_fn	claim_block;
75 
76 	/*
77 	 * This function should return the size of the in-core btree root
78 	 * block.  It is only necessary for XFS_BTREE_TYPE_INODE btrees.
79 	 */
80 	xfs_btree_bload_iroot_size_fn	iroot_size;
81 
82 	/*
83 	 * The caller should set this to the number of records that will be
84 	 * stored in the new btree.
85 	 */
86 	uint64_t			nr_records;
87 
88 	/*
89 	 * Number of free records to leave in each leaf block.  If the caller
90 	 * sets this to -1, the slack value will be calculated to be halfway
91 	 * between maxrecs and minrecs.  This typically leaves the block 75%
92 	 * full.  Note that slack values are not enforced on inode root blocks.
93 	 */
94 	int				leaf_slack;
95 
96 	/*
97 	 * Number of free key/ptrs pairs to leave in each node block.  This
98 	 * field has the same semantics as leaf_slack.
99 	 */
100 	int				node_slack;
101 
102 	/*
103 	 * The xfs_btree_bload_compute_geometry function will set this to the
104 	 * number of btree blocks needed to store nr_records records.
105 	 */
106 	uint64_t			nr_blocks;
107 
108 	/*
109 	 * The xfs_btree_bload_compute_geometry function will set this to the
110 	 * height of the new btree.
111 	 */
112 	unsigned int			btree_height;
113 
114 	/*
115 	 * Flush the new btree block buffer list to disk after this many blocks
116 	 * have been formatted.  Zero prohibits writing any buffers until all
117 	 * blocks have been formatted.
118 	 */
119 	uint16_t			max_dirty;
120 
121 	/* Number of dirty buffers. */
122 	uint16_t			nr_dirty;
123 };
124 
125 int xfs_btree_bload_compute_geometry(struct xfs_btree_cur *cur,
126 		struct xfs_btree_bload *bbl, uint64_t nr_records);
127 int xfs_btree_bload(struct xfs_btree_cur *cur, struct xfs_btree_bload *bbl,
128 		void *priv);
129 
130 #endif	/* __XFS_BTREE_STAGING_H__ */
131