bcachefs: Fix bch2_extent_fallocate() in nocow mode

When we allocate disk space, we need to be incrementing the WRITE io
clock, which perhaps should be renamed to sectors allocated - copygc
uses this io clock to know when to run.

Also, we should be incrementing the same clock when allocating btree
nodes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_update_interior.c

@@ -11,6 +11,7 @@
 #include "btree_iter.h"
 #include "btree_locking.h"
 #include "buckets.h"
+#include "clock.h"
 #include "error.h"
 #include "extents.h"
 #include "journal.h"
@@ -363,6 +364,7 @@ static struct btree *bch2_btree_node_alloc(struct btree_update *as,
 	BUG_ON(ret);
 
 	trace_and_count(c, btree_node_alloc, c, b);
+	bch2_increment_clock(c, btree_sectors(c), WRITE);
 	return b;
 }
 

fs/bcachefs/io.c

@@ -384,6 +384,7 @@ int bch2_extent_fallocate(struct btree_trans *trans,
 	struct open_buckets open_buckets;
 	struct bkey_s_c k;
 	struct bkey_buf old, new;
+	unsigned sectors_allocated;
 	bool have_reservation = false;
 	bool unwritten = opts.nocow &&
 	    c->sb.version >= bcachefs_metadata_version_unwritten_extents;
@@ -394,6 +395,8 @@ int bch2_extent_fallocate(struct btree_trans *trans,
 	closure_init_stack(&cl);
 	open_buckets.nr = 0;
 retry:
+	sectors_allocated = 0;
+
 	k = bch2_btree_iter_peek_slot(iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -459,6 +462,7 @@ int bch2_extent_fallocate(struct btree_trans *trans,
 			return ret;
 
 		sectors = min(sectors, wp->sectors_free);
+		sectors_allocated = sectors;
 
 		bch2_key_resize(&e->k, sectors);
 
@@ -485,6 +489,9 @@ int bch2_extent_fallocate(struct btree_trans *trans,
 		goto retry;
 	}
 
+	if (!ret && sectors_allocated)
+		bch2_increment_clock(c, sectors_allocated, WRITE);
+
 	bch2_open_buckets_put(c, &open_buckets);
 	bch2_disk_reservation_put(c, &disk_res);
 	bch2_bkey_buf_exit(&new, c);