88 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			88 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef _BCACHEFS_BTREE_GC_H
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| #define _BCACHEFS_BTREE_GC_H
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| 
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| #include "bkey.h"
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| #include "btree_gc_types.h"
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| #include "btree_types.h"
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| 
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| int bch2_check_topology(struct bch_fs *);
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| int bch2_check_allocations(struct bch_fs *);
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| 
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| /*
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|  * For concurrent mark and sweep (with other index updates), we define a total
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|  * ordering of _all_ references GC walks:
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|  *
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|  * Note that some references will have the same GC position as others - e.g.
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|  * everything within the same btree node; in those cases we're relying on
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|  * whatever locking exists for where those references live, i.e. the write lock
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|  * on a btree node.
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|  *
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|  * That locking is also required to ensure GC doesn't pass the updater in
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|  * between the updater adding/removing the reference and updating the GC marks;
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|  * without that, we would at best double count sometimes.
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|  *
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|  * That part is important - whenever calling bch2_mark_pointers(), a lock _must_
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|  * be held that prevents GC from passing the position the updater is at.
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|  *
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|  * (What about the start of gc, when we're clearing all the marks? GC clears the
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|  * mark with the gc pos seqlock held, and bch_mark_bucket checks against the gc
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|  * position inside its cmpxchg loop, so crap magically works).
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|  */
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| 
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| /* Position of (the start of) a gc phase: */
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| static inline struct gc_pos gc_phase(enum gc_phase phase)
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| {
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| 	return (struct gc_pos) { .phase	= phase, };
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| }
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| 
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| static inline struct gc_pos gc_pos_btree(enum btree_id btree, unsigned level,
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| 					 struct bpos pos)
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| {
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| 	return (struct gc_pos) {
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| 		.phase	= GC_PHASE_btree,
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| 		.btree	= btree,
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| 		.level	= level,
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| 		.pos	= pos,
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| 	};
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| }
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| 
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| static inline int gc_btree_order(enum btree_id btree)
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| {
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| 	if (btree == BTREE_ID_alloc)
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| 		return -2;
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| 	if (btree == BTREE_ID_stripes)
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| 		return -1;
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| 	return btree;
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| }
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| 
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| static inline int gc_pos_cmp(struct gc_pos l, struct gc_pos r)
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| {
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| 	return  cmp_int(l.phase, r.phase) ?:
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| 		cmp_int(gc_btree_order(l.btree),
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| 			gc_btree_order(r.btree)) ?:
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| 		cmp_int(l.level, r.level) ?:
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| 		bpos_cmp(l.pos, r.pos);
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| }
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| 
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| static inline bool gc_visited(struct bch_fs *c, struct gc_pos pos)
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| {
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| 	unsigned seq;
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| 	bool ret;
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| 
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| 	do {
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| 		seq = read_seqcount_begin(&c->gc_pos_lock);
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| 		ret = gc_pos_cmp(pos, c->gc_pos) <= 0;
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| 	} while (read_seqcount_retry(&c->gc_pos_lock, seq));
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| 
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| 	return ret;
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| }
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| 
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| void bch2_gc_pos_to_text(struct printbuf *, struct gc_pos *);
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| 
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| int bch2_gc_gens(struct bch_fs *);
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| void bch2_gc_gens_async(struct bch_fs *);
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| void bch2_fs_gc_init(struct bch_fs *);
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| 
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| #endif /* _BCACHEFS_BTREE_GC_H */
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