bcachefs: Kill bch2_invalidate_bucket()

This patch is working towards eventually getting rid of the in memory
struct bucket, and relying only on the btree representation.

Since bch2_invalidate_bucket() was only used for incrementing gens, not
invalidating cached data, no other counters were being changed as a side
effect - meaning it's safe for the allocator code to increment the
bucket gen directly.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/alloc_background.c

@@ -896,34 +896,32 @@ static int bch2_invalidate_one_bucket2(struct btree_trans *trans,
 
 	/* first, put on free_inc and mark as owned by allocator: */
 	percpu_down_read(&c->mark_lock);
-	spin_lock(&c->freelist_lock);
-
-	verify_not_on_freelist(c, ca, b);
-
-	BUG_ON(!fifo_push(&ca->free_inc, b));
-
 	g = bucket(ca, b);
 	m = READ_ONCE(g->mark);
 
-	invalidating_cached_data = m.cached_sectors != 0;
+	BUG_ON(m.data_type || m.dirty_sectors);
+
+	bch2_mark_alloc_bucket(c, ca, b, true, gc_pos_alloc(c, NULL), 0);
+
+	spin_lock(&c->freelist_lock);
+	verify_not_on_freelist(c, ca, b);
+	BUG_ON(!fifo_push(&ca->free_inc, b));
+	spin_unlock(&c->freelist_lock);
 
 	/*
 	 * If we're not invalidating cached data, we only increment the bucket
 	 * gen in memory here, the incremented gen will be updated in the btree
 	 * by bch2_trans_mark_pointer():
 	 */
+	if (!m.cached_sectors &&
+	    !bucket_needs_journal_commit(m, c->journal.last_seq_ondisk)) {
+		bucket_cmpxchg(g, m, m.gen++);
+		percpu_up_read(&c->mark_lock);
+		goto out;
+	}
 
-	if (!invalidating_cached_data)
-		bch2_invalidate_bucket(c, ca, b, &m);
-	else
-		bch2_mark_alloc_bucket(c, ca, b, true, gc_pos_alloc(c, NULL), 0);
-
-	spin_unlock(&c->freelist_lock);
 	percpu_up_read(&c->mark_lock);
 
-	if (!invalidating_cached_data)
-		goto out;
-
 	/*
 	 * If the read-only path is trying to shut down, we can't be generating
 	 * new btree updates:

fs/bcachefs/buckets.c

@@ -644,46 +644,6 @@ int bch2_replicas_delta_list_apply(struct bch_fs *c,
 	ret;								\
 })
 
-static int __bch2_invalidate_bucket(struct bch_fs *c, struct bch_dev *ca,
-				    size_t b, struct bucket_mark *ret,
-				    bool gc)
-{
-	struct bch_fs_usage *fs_usage = fs_usage_ptr(c, 0, gc);
-	struct bucket *g = __bucket(ca, b, gc);
-	struct bucket_mark old, new;
-
-	old = bucket_cmpxchg(g, new, ({
-		BUG_ON(!is_available_bucket(new));
-
-		new.owned_by_allocator	= true;
-		new.data_type		= 0;
-		new.cached_sectors	= 0;
-		new.dirty_sectors	= 0;
-		new.gen++;
-	}));
-
-	bch2_dev_usage_update(c, ca, fs_usage, old, new, gc);
-
-	if (old.cached_sectors)
-		update_cached_sectors(c, fs_usage, ca->dev_idx,
-				      -((s64) old.cached_sectors));
-
-	if (!gc)
-		*ret = old;
-	return 0;
-}
-
-void bch2_invalidate_bucket(struct bch_fs *c, struct bch_dev *ca,
-			    size_t b, struct bucket_mark *old)
-{
-	do_mark_fn(__bch2_invalidate_bucket, c, gc_phase(GC_PHASE_START), 0,
-		   ca, b, old);
-
-	if (!old->owned_by_allocator && old->cached_sectors)
-		trace_invalidate(ca, bucket_to_sector(ca, b),
-				 old->cached_sectors);
-}
-
 static int __bch2_mark_alloc_bucket(struct bch_fs *c, struct bch_dev *ca,
 				    size_t b, bool owned_by_allocator,
 				    bool gc)

fs/bcachefs/buckets.h

@@ -236,8 +236,6 @@ bch2_fs_usage_read_short(struct bch_fs *);
 void bch2_bucket_seq_cleanup(struct bch_fs *);
 void bch2_fs_usage_initialize(struct bch_fs *);
 
-void bch2_invalidate_bucket(struct bch_fs *, struct bch_dev *,
-			    size_t, struct bucket_mark *);
 void bch2_mark_alloc_bucket(struct bch_fs *, struct bch_dev *,
 			    size_t, bool, struct gc_pos, unsigned);
 void bch2_mark_metadata_bucket(struct bch_fs *, struct bch_dev *,