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;	/* passive reference count */
36 	atomic_t	pag_active_ref;	/* active reference count */
37 	wait_queue_head_t pag_active_wq;/* woken active_ref falls to zero */
38 	unsigned long	pag_opstate;
39 	uint8_t		pagf_bno_level;	/* # of levels in bno btree */
40 	uint8_t		pagf_cnt_level;	/* # of levels in cnt btree */
41 	uint8_t		pagf_rmap_level;/* # of levels in rmap btree */
42 	uint32_t	pagf_flcount;	/* count of blocks in freelist */
43 	xfs_extlen_t	pagf_freeblks;	/* total free blocks */
44 	xfs_extlen_t	pagf_longest;	/* longest free space */
45 	uint32_t	pagf_btreeblks;	/* # of blocks held in AGF btrees */
46 	xfs_agino_t	pagi_freecount;	/* number of free inodes */
47 	xfs_agino_t	pagi_count;	/* number of allocated inodes */
48 
49 	/*
50 	 * Inode allocation search lookup optimisation.
51 	 * If the pagino matches, the search for new inodes
52 	 * doesn't need to search the near ones again straight away
53 	 */
54 	xfs_agino_t	pagl_pagino;
55 	xfs_agino_t	pagl_leftrec;
56 	xfs_agino_t	pagl_rightrec;
57 
58 	int		pagb_count;	/* pagb slots in use */
59 	uint8_t		pagf_refcount_level; /* recount btree height */
60 
61 	/* Blocks reserved for all kinds of metadata. */
62 	struct xfs_ag_resv	pag_meta_resv;
63 	/* Blocks reserved for the reverse mapping btree. */
64 	struct xfs_ag_resv	pag_rmapbt_resv;
65 
66 	/* Precalculated geometry info */
67 	xfs_agblock_t		block_count;
68 	xfs_agblock_t		min_block;
69 	xfs_agino_t		agino_min;
70 	xfs_agino_t		agino_max;
71 
72 #ifdef __KERNEL__
73 	/* -- kernel only structures below this line -- */
74 
75 	/*
76 	 * Bitsets of per-ag metadata that have been checked and/or are sick.
77 	 * Callers should hold pag_state_lock before accessing this field.
78 	 */
79 	uint16_t	pag_checked;
80 	uint16_t	pag_sick;
81 
82 #ifdef CONFIG_XFS_ONLINE_REPAIR
83 	/*
84 	 * Alternate btree heights so that online repair won't trip the write
85 	 * verifiers while rebuilding the AG btrees.
86 	 */
87 	uint8_t		pagf_repair_bno_level;
88 	uint8_t		pagf_repair_cnt_level;
89 	uint8_t		pagf_repair_refcount_level;
90 	uint8_t		pagf_repair_rmap_level;
91 #endif
92 
93 	spinlock_t	pag_state_lock;
94 
95 	spinlock_t	pagb_lock;	/* lock for pagb_tree */
96 	struct rb_root	pagb_tree;	/* ordered tree of busy extents */
97 	unsigned int	pagb_gen;	/* generation count for pagb_tree */
98 	wait_queue_head_t pagb_wait;	/* woken when pagb_gen changes */
99 
100 	atomic_t        pagf_fstrms;    /* # of filestreams active in this AG */
101 
102 	spinlock_t	pag_ici_lock;	/* incore inode cache lock */
103 	struct radix_tree_root pag_ici_root;	/* incore inode cache root */
104 	int		pag_ici_reclaimable;	/* reclaimable inodes */
105 	unsigned long	pag_ici_reclaim_cursor;	/* reclaim restart point */
106 
107 	struct xfs_buf_cache	pag_bcache;
108 
109 	/* background prealloc block trimming */
110 	struct delayed_work	pag_blockgc_work;
111 
112 	/*
113 	 * We use xfs_drain to track the number of deferred log intent items
114 	 * that have been queued (but not yet processed) so that waiters (e.g.
115 	 * scrub) will not lock resources when other threads are in the middle
116 	 * of processing a chain of intent items only to find momentary
117 	 * inconsistencies.
118 	 */
119 	struct xfs_defer_drain	pag_intents_drain;
120 
121 	/* Hook to feed rmapbt updates to an active online repair. */
122 	struct xfs_hooks	pag_rmap_update_hooks;
123 #endif /* __KERNEL__ */
124 };
125 
126 /*
127  * Per-AG operational state. These are atomic flag bits.
128  */
129 #define XFS_AGSTATE_AGF_INIT		0
130 #define XFS_AGSTATE_AGI_INIT		1
131 #define XFS_AGSTATE_PREFERS_METADATA	2
132 #define XFS_AGSTATE_ALLOWS_INODES	3
133 #define XFS_AGSTATE_AGFL_NEEDS_RESET	4
134 
135 #define __XFS_AG_OPSTATE(name, NAME) \
136 static inline bool xfs_perag_ ## name (struct xfs_perag *pag) \
137 { \
138 	return test_bit(XFS_AGSTATE_ ## NAME, &pag->pag_opstate); \
139 }
140 
141 __XFS_AG_OPSTATE(initialised_agf, AGF_INIT)
142 __XFS_AG_OPSTATE(initialised_agi, AGI_INIT)
143 __XFS_AG_OPSTATE(prefers_metadata, PREFERS_METADATA)
144 __XFS_AG_OPSTATE(allows_inodes, ALLOWS_INODES)
145 __XFS_AG_OPSTATE(agfl_needs_reset, AGFL_NEEDS_RESET)
146 
147 int xfs_initialize_perag(struct xfs_mount *mp, xfs_agnumber_t old_agcount,
148 		xfs_agnumber_t agcount, xfs_rfsblock_t dcount,
149 		xfs_agnumber_t *maxagi);
150 void xfs_free_perag_range(struct xfs_mount *mp, xfs_agnumber_t first_agno,
151 		xfs_agnumber_t end_agno);
152 int xfs_initialize_perag_data(struct xfs_mount *mp, xfs_agnumber_t agno);
153 int xfs_update_last_ag_size(struct xfs_mount *mp, xfs_agnumber_t prev_agcount);
154 
155 /* Passive AG references */
156 struct xfs_perag *xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno);
157 struct xfs_perag *xfs_perag_hold(struct xfs_perag *pag);
158 void xfs_perag_put(struct xfs_perag *pag);
159 
160 /* Active AG references */
161 struct xfs_perag *xfs_perag_grab(struct xfs_mount *, xfs_agnumber_t);
162 void xfs_perag_rele(struct xfs_perag *pag);
163 
164 /*
165  * Per-ag geometry infomation and validation
166  */
167 xfs_agblock_t xfs_ag_block_count(struct xfs_mount *mp, xfs_agnumber_t agno);
168 void xfs_agino_range(struct xfs_mount *mp, xfs_agnumber_t agno,
169 		xfs_agino_t *first, xfs_agino_t *last);
170 
171 static inline bool
xfs_verify_agbno(struct xfs_perag * pag,xfs_agblock_t agbno)172 xfs_verify_agbno(struct xfs_perag *pag, xfs_agblock_t agbno)
173 {
174 	if (agbno >= pag->block_count)
175 		return false;
176 	if (agbno <= pag->min_block)
177 		return false;
178 	return true;
179 }
180 
181 static inline bool
xfs_verify_agbext(struct xfs_perag * pag,xfs_agblock_t agbno,xfs_agblock_t len)182 xfs_verify_agbext(
183 	struct xfs_perag	*pag,
184 	xfs_agblock_t		agbno,
185 	xfs_agblock_t		len)
186 {
187 	if (agbno + len <= agbno)
188 		return false;
189 
190 	if (!xfs_verify_agbno(pag, agbno))
191 		return false;
192 
193 	return xfs_verify_agbno(pag, agbno + len - 1);
194 }
195 
196 /*
197  * Verify that an AG inode number pointer neither points outside the AG
198  * nor points at static metadata.
199  */
200 static inline bool
xfs_verify_agino(struct xfs_perag * pag,xfs_agino_t agino)201 xfs_verify_agino(struct xfs_perag *pag, xfs_agino_t agino)
202 {
203 	if (agino < pag->agino_min)
204 		return false;
205 	if (agino > pag->agino_max)
206 		return false;
207 	return true;
208 }
209 
210 /*
211  * Verify that an AG inode number pointer neither points outside the AG
212  * nor points at static metadata, or is NULLAGINO.
213  */
214 static inline bool
xfs_verify_agino_or_null(struct xfs_perag * pag,xfs_agino_t agino)215 xfs_verify_agino_or_null(struct xfs_perag *pag, xfs_agino_t agino)
216 {
217 	if (agino == NULLAGINO)
218 		return true;
219 	return xfs_verify_agino(pag, agino);
220 }
221 
222 static inline bool
xfs_ag_contains_log(struct xfs_mount * mp,xfs_agnumber_t agno)223 xfs_ag_contains_log(struct xfs_mount *mp, xfs_agnumber_t agno)
224 {
225 	return mp->m_sb.sb_logstart > 0 &&
226 	       agno == XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart);
227 }
228 
229 /*
230  * Perag iteration APIs
231  */
232 static inline struct xfs_perag *
xfs_perag_next(struct xfs_perag * pag,xfs_agnumber_t * agno,xfs_agnumber_t end_agno)233 xfs_perag_next(
234 	struct xfs_perag	*pag,
235 	xfs_agnumber_t		*agno,
236 	xfs_agnumber_t		end_agno)
237 {
238 	struct xfs_mount	*mp = pag->pag_mount;
239 
240 	*agno = pag->pag_agno + 1;
241 	xfs_perag_rele(pag);
242 	while (*agno <= end_agno) {
243 		pag = xfs_perag_grab(mp, *agno);
244 		if (pag)
245 			return pag;
246 		(*agno)++;
247 	}
248 	return NULL;
249 }
250 
251 #define for_each_perag_range(mp, agno, end_agno, pag) \
252 	for ((pag) = xfs_perag_grab((mp), (agno)); \
253 		(pag) != NULL; \
254 		(pag) = xfs_perag_next((pag), &(agno), (end_agno)))
255 
256 #define for_each_perag_from(mp, agno, pag) \
257 	for_each_perag_range((mp), (agno), (mp)->m_sb.sb_agcount - 1, (pag))
258 
259 #define for_each_perag(mp, agno, pag) \
260 	(agno) = 0; \
261 	for_each_perag_from((mp), (agno), (pag))
262 
263 static inline struct xfs_perag *
xfs_perag_next_wrap(struct xfs_perag * pag,xfs_agnumber_t * agno,xfs_agnumber_t stop_agno,xfs_agnumber_t restart_agno,xfs_agnumber_t wrap_agno)264 xfs_perag_next_wrap(
265 	struct xfs_perag	*pag,
266 	xfs_agnumber_t		*agno,
267 	xfs_agnumber_t		stop_agno,
268 	xfs_agnumber_t		restart_agno,
269 	xfs_agnumber_t		wrap_agno)
270 {
271 	struct xfs_mount	*mp = pag->pag_mount;
272 
273 	*agno = pag->pag_agno + 1;
274 	xfs_perag_rele(pag);
275 	while (*agno != stop_agno) {
276 		if (*agno >= wrap_agno) {
277 			if (restart_agno >= stop_agno)
278 				break;
279 			*agno = restart_agno;
280 		}
281 
282 		pag = xfs_perag_grab(mp, *agno);
283 		if (pag)
284 			return pag;
285 		(*agno)++;
286 	}
287 	return NULL;
288 }
289 
290 /*
291  * Iterate all AGs from start_agno through wrap_agno, then restart_agno through
292  * (start_agno - 1).
293  */
294 #define for_each_perag_wrap_range(mp, start_agno, restart_agno, wrap_agno, agno, pag) \
295 	for ((agno) = (start_agno), (pag) = xfs_perag_grab((mp), (agno)); \
296 		(pag) != NULL; \
297 		(pag) = xfs_perag_next_wrap((pag), &(agno), (start_agno), \
298 				(restart_agno), (wrap_agno)))
299 /*
300  * Iterate all AGs from start_agno through wrap_agno, then 0 through
301  * (start_agno - 1).
302  */
303 #define for_each_perag_wrap_at(mp, start_agno, wrap_agno, agno, pag) \
304 	for_each_perag_wrap_range((mp), (start_agno), 0, (wrap_agno), (agno), (pag))
305 
306 /*
307  * Iterate all AGs from start_agno through to the end of the filesystem, then 0
308  * through (start_agno - 1).
309  */
310 #define for_each_perag_wrap(mp, start_agno, agno, pag) \
311 	for_each_perag_wrap_at((mp), (start_agno), (mp)->m_sb.sb_agcount, \
312 				(agno), (pag))
313 
314 
315 struct aghdr_init_data {
316 	/* per ag data */
317 	xfs_agblock_t		agno;		/* ag to init */
318 	xfs_extlen_t		agsize;		/* new AG size */
319 	struct list_head	buffer_list;	/* buffer writeback list */
320 	xfs_rfsblock_t		nfree;		/* cumulative new free space */
321 
322 	/* per header data */
323 	xfs_daddr_t		daddr;		/* header location */
324 	size_t			numblks;	/* size of header */
325 	const struct xfs_btree_ops *bc_ops;	/* btree ops */
326 };
327 
328 int xfs_ag_init_headers(struct xfs_mount *mp, struct aghdr_init_data *id);
329 int xfs_ag_shrink_space(struct xfs_perag *pag, struct xfs_trans **tpp,
330 			xfs_extlen_t delta);
331 int xfs_ag_extend_space(struct xfs_perag *pag, struct xfs_trans *tp,
332 			xfs_extlen_t len);
333 int xfs_ag_get_geometry(struct xfs_perag *pag, struct xfs_ag_geometry *ageo);
334 
335 #endif /* __LIBXFS_AG_H */
336