1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 2018 Red Hat, Inc.
4  * All rights reserved.
5  */
6 
7 #ifndef __LIBXFS_AG_H
8 #define __LIBXFS_AG_H 1
9 
10 struct xfs_mount;
11 struct xfs_trans;
12 struct xfs_perag;
13 
14 /*
15  * Per-ag infrastructure
16  */
17 
18 /* per-AG block reservation data structures*/
19 struct xfs_ag_resv {
20 	/* number of blocks originally reserved here */
21 	xfs_extlen_t			ar_orig_reserved;
22 	/* number of blocks reserved here */
23 	xfs_extlen_t			ar_reserved;
24 	/* number of blocks originally asked for */
25 	xfs_extlen_t			ar_asked;
26 };
27 
28 /*
29  * Per-ag incore structure, copies of information in agf and agi, to improve the
30  * performance of allocation group selection.
31  */
32 struct xfs_perag {
33 	struct xfs_mount *pag_mount;	/* owner filesystem */
34 	xfs_agnumber_t	pag_agno;	/* AG this structure belongs to */
35 	atomic_t	pag_ref;	/* perag reference count */
36 	char		pagf_init;	/* this agf's entry is initialized */
37 	char		pagi_init;	/* this agi's entry is initialized */
38 	char		pagf_metadata;	/* the agf is preferred to be metadata */
39 	char		pagi_inodeok;	/* The agi is ok for inodes */
40 	uint8_t		pagf_levels[XFS_BTNUM_AGF];
41 					/* # of levels in bno & cnt btree */
42 	bool		pagf_agflreset; /* agfl requires reset before use */
43 	uint32_t	pagf_flcount;	/* count of blocks in freelist */
44 	xfs_extlen_t	pagf_freeblks;	/* total free blocks */
45 	xfs_extlen_t	pagf_longest;	/* longest free space */
46 	uint32_t	pagf_btreeblks;	/* # of blocks held in AGF btrees */
47 	xfs_agino_t	pagi_freecount;	/* number of free inodes */
48 	xfs_agino_t	pagi_count;	/* number of allocated inodes */
49 
50 	/*
51 	 * Inode allocation search lookup optimisation.
52 	 * If the pagino matches, the search for new inodes
53 	 * doesn't need to search the near ones again straight away
54 	 */
55 	xfs_agino_t	pagl_pagino;
56 	xfs_agino_t	pagl_leftrec;
57 	xfs_agino_t	pagl_rightrec;
58 
59 	int		pagb_count;	/* pagb slots in use */
60 	uint8_t		pagf_refcount_level; /* recount btree height */
61 
62 	/* Blocks reserved for all kinds of metadata. */
63 	struct xfs_ag_resv	pag_meta_resv;
64 	/* Blocks reserved for the reverse mapping btree. */
65 	struct xfs_ag_resv	pag_rmapbt_resv;
66 
67 	/* for rcu-safe freeing */
68 	struct rcu_head	rcu_head;
69 
70 	/* Precalculated geometry info */
71 	xfs_agblock_t		block_count;
72 	xfs_agblock_t		min_block;
73 	xfs_agino_t		agino_min;
74 	xfs_agino_t		agino_max;
75 
76 #ifdef __KERNEL__
77 	/* -- kernel only structures below this line -- */
78 
79 	/*
80 	 * Bitsets of per-ag metadata that have been checked and/or are sick.
81 	 * Callers should hold pag_state_lock before accessing this field.
82 	 */
83 	uint16_t	pag_checked;
84 	uint16_t	pag_sick;
85 	spinlock_t	pag_state_lock;
86 
87 	spinlock_t	pagb_lock;	/* lock for pagb_tree */
88 	struct rb_root	pagb_tree;	/* ordered tree of busy extents */
89 	unsigned int	pagb_gen;	/* generation count for pagb_tree */
90 	wait_queue_head_t pagb_wait;	/* woken when pagb_gen changes */
91 
92 	atomic_t        pagf_fstrms;    /* # of filestreams active in this AG */
93 
94 	spinlock_t	pag_ici_lock;	/* incore inode cache lock */
95 	struct radix_tree_root pag_ici_root;	/* incore inode cache root */
96 	int		pag_ici_reclaimable;	/* reclaimable inodes */
97 	unsigned long	pag_ici_reclaim_cursor;	/* reclaim restart point */
98 
99 	/* buffer cache index */
100 	spinlock_t	pag_buf_lock;	/* lock for pag_buf_hash */
101 	struct rhashtable pag_buf_hash;
102 
103 	/* background prealloc block trimming */
104 	struct delayed_work	pag_blockgc_work;
105 
106 #endif /* __KERNEL__ */
107 };
108 
109 int xfs_initialize_perag(struct xfs_mount *mp, xfs_agnumber_t agcount,
110 			xfs_rfsblock_t dcount, xfs_agnumber_t *maxagi);
111 int xfs_initialize_perag_data(struct xfs_mount *mp, xfs_agnumber_t agno);
112 void xfs_free_perag(struct xfs_mount *mp);
113 
114 struct xfs_perag *xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno);
115 struct xfs_perag *xfs_perag_get_tag(struct xfs_mount *mp, xfs_agnumber_t agno,
116 		unsigned int tag);
117 void xfs_perag_put(struct xfs_perag *pag);
118 
119 /*
120  * Per-ag geometry infomation and validation
121  */
122 xfs_agblock_t xfs_ag_block_count(struct xfs_mount *mp, xfs_agnumber_t agno);
123 void xfs_agino_range(struct xfs_mount *mp, xfs_agnumber_t agno,
124 		xfs_agino_t *first, xfs_agino_t *last);
125 
126 static inline bool
xfs_verify_agbno(struct xfs_perag * pag,xfs_agblock_t agbno)127 xfs_verify_agbno(struct xfs_perag *pag, xfs_agblock_t agbno)
128 {
129 	if (agbno >= pag->block_count)
130 		return false;
131 	if (agbno <= pag->min_block)
132 		return false;
133 	return true;
134 }
135 
136 static inline bool
xfs_verify_agbext(struct xfs_perag * pag,xfs_agblock_t agbno,xfs_agblock_t len)137 xfs_verify_agbext(
138 	struct xfs_perag	*pag,
139 	xfs_agblock_t		agbno,
140 	xfs_agblock_t		len)
141 {
142 	if (agbno + len <= agbno)
143 		return false;
144 
145 	if (!xfs_verify_agbno(pag, agbno))
146 		return false;
147 
148 	return xfs_verify_agbno(pag, agbno + len - 1);
149 }
150 
151 /*
152  * Verify that an AG inode number pointer neither points outside the AG
153  * nor points at static metadata.
154  */
155 static inline bool
xfs_verify_agino(struct xfs_perag * pag,xfs_agino_t agino)156 xfs_verify_agino(struct xfs_perag *pag, xfs_agino_t agino)
157 {
158 	if (agino < pag->agino_min)
159 		return false;
160 	if (agino > pag->agino_max)
161 		return false;
162 	return true;
163 }
164 
165 /*
166  * Verify that an AG inode number pointer neither points outside the AG
167  * nor points at static metadata, or is NULLAGINO.
168  */
169 static inline bool
xfs_verify_agino_or_null(struct xfs_perag * pag,xfs_agino_t agino)170 xfs_verify_agino_or_null(struct xfs_perag *pag, xfs_agino_t agino)
171 {
172 	if (agino == NULLAGINO)
173 		return true;
174 	return xfs_verify_agino(pag, agino);
175 }
176 
177 static inline bool
xfs_ag_contains_log(struct xfs_mount * mp,xfs_agnumber_t agno)178 xfs_ag_contains_log(struct xfs_mount *mp, xfs_agnumber_t agno)
179 {
180 	return mp->m_sb.sb_logstart > 0 &&
181 	       agno == XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart);
182 }
183 
184 /*
185  * Perag iteration APIs
186  */
187 static inline struct xfs_perag *
xfs_perag_next(struct xfs_perag * pag,xfs_agnumber_t * agno,xfs_agnumber_t end_agno)188 xfs_perag_next(
189 	struct xfs_perag	*pag,
190 	xfs_agnumber_t		*agno,
191 	xfs_agnumber_t		end_agno)
192 {
193 	struct xfs_mount	*mp = pag->pag_mount;
194 
195 	*agno = pag->pag_agno + 1;
196 	xfs_perag_put(pag);
197 	if (*agno > end_agno)
198 		return NULL;
199 	return xfs_perag_get(mp, *agno);
200 }
201 
202 #define for_each_perag_range(mp, agno, end_agno, pag) \
203 	for ((pag) = xfs_perag_get((mp), (agno)); \
204 		(pag) != NULL; \
205 		(pag) = xfs_perag_next((pag), &(agno), (end_agno)))
206 
207 #define for_each_perag_from(mp, agno, pag) \
208 	for_each_perag_range((mp), (agno), (mp)->m_sb.sb_agcount - 1, (pag))
209 
210 
211 #define for_each_perag(mp, agno, pag) \
212 	(agno) = 0; \
213 	for_each_perag_from((mp), (agno), (pag))
214 
215 #define for_each_perag_tag(mp, agno, pag, tag) \
216 	for ((agno) = 0, (pag) = xfs_perag_get_tag((mp), 0, (tag)); \
217 		(pag) != NULL; \
218 		(agno) = (pag)->pag_agno + 1, \
219 		xfs_perag_put(pag), \
220 		(pag) = xfs_perag_get_tag((mp), (agno), (tag)))
221 
222 struct aghdr_init_data {
223 	/* per ag data */
224 	xfs_agblock_t		agno;		/* ag to init */
225 	xfs_extlen_t		agsize;		/* new AG size */
226 	struct list_head	buffer_list;	/* buffer writeback list */
227 	xfs_rfsblock_t		nfree;		/* cumulative new free space */
228 
229 	/* per header data */
230 	xfs_daddr_t		daddr;		/* header location */
231 	size_t			numblks;	/* size of header */
232 	xfs_btnum_t		type;		/* type of btree root block */
233 };
234 
235 int xfs_ag_init_headers(struct xfs_mount *mp, struct aghdr_init_data *id);
236 int xfs_ag_shrink_space(struct xfs_perag *pag, struct xfs_trans **tpp,
237 			xfs_extlen_t delta);
238 int xfs_ag_extend_space(struct xfs_perag *pag, struct xfs_trans *tp,
239 			xfs_extlen_t len);
240 int xfs_ag_get_geometry(struct xfs_perag *pag, struct xfs_ag_geometry *ageo);
241 
242 #endif /* __LIBXFS_AG_H */
243