3  * Primary bucket allocation code
9  * Each bucket has associated an 8 bit gen; this gen corresponds to the gen in
12  * Thus (assuming a bucket has no dirty data or metadata in it) we can reuse a
13  * bucket simply by incrementing its gen.
19  * When we invalidate a bucket, we have to write its new gen to disk and wait
33  * If we've got discards enabled, that happens when a bucket moves from the
46  * a bucket is in danger of wrapping around we simply skip invalidating it that
50  * bch_bucket_alloc() allocates a single bucket from a specific cache.
52  * bch_bucket_alloc_set() allocates one  bucket from different caches
74 /* Bucket heap / gen */
76 uint8_t bch_inc_gen(struct cache *ca, struct bucket *b)  in bch_inc_gen()
89 	struct bucket *b;  in bch_rescale_priorities()
125 static inline bool can_inc_bucket_gen(struct bucket *b)  in can_inc_bucket_gen()
130 bool bch_can_invalidate_bucket(struct cache *ca, struct bucket *b)  in bch_can_invalidate_bucket()
137 void __bch_invalidate_one_bucket(struct cache *ca, struct bucket *b)  in __bch_invalidate_one_bucket()
151 static void bch_invalidate_one_bucket(struct cache *ca, struct bucket *b)  in bch_invalidate_one_bucket()
161  * bucket, and in order for that multiply to make sense we have to scale bucket
163  * Thus, we scale the bucket priorities so that the bucket with the smallest
167 static inline unsigned int new_bucket_prio(struct cache *ca, struct bucket *b)  in new_bucket_prio()
176 	struct bucket **lhs = (struct bucket **)l;  in new_bucket_max_cmp()
177 	struct bucket **rhs = (struct bucket **)r;  in new_bucket_max_cmp()
185 	struct bucket **lhs = (struct bucket **)l;  in new_bucket_min_cmp()
186 	struct bucket **rhs = (struct bucket **)r;  in new_bucket_min_cmp()
194 	struct bucket *b;  in invalidate_buckets_lru()
239 	struct bucket *b;  in invalidate_buckets_fifo()
262 	struct bucket *b;  in invalidate_buckets_random()
323 static int bch_allocator_push(struct cache *ca, long bucket)  in bch_allocator_push()  argument
328 	if (fifo_push(&ca->free[RESERVE_PRIO], bucket))  in bch_allocator_push()
332 		if (fifo_push(&ca->free[i], bucket))  in bch_allocator_push()
347 		 * possibly issue discards to them, then we add the bucket to  in bch_allocator_thread()
351 			long bucket;  in bch_allocator_thread()  local
353 			if (!fifo_pop(&ca->free_inc, bucket))  in bch_allocator_thread()
359 					bucket_to_sector(ca->set, bucket),  in bch_allocator_thread()
364 			allocator_wait(ca, bch_allocator_push(ca, bucket));  in bch_allocator_thread()
415 	struct bucket *b;  in bch_bucket_alloc()
489 void __bch_bucket_free(struct cache *ca, struct bucket *b)  in __bch_bucket_free()
559  * only volume write streams from cached devices, secondly we look for a bucket
561  * failing that we look for a bucket that was last used by the same task.
634 	 * We might have to allocate a new bucket, which we can't do with a  in bch_alloc_sectors()
637 	 * allocated bucket(s).  in bch_alloc_sectors()
658 	 * second time we call pick_data_bucket(). If we allocated a bucket but  in bch_alloc_sectors()
679 	 * Move b to the end of the lru, and keep track of what this bucket was  in bch_alloc_sectors()
700 	 * into the btree, but if we're done with this bucket we just transfer  in bch_alloc_sectors()