bcachefs: Call bch2_do_invalidates() when going read write

Like bch2_do_discards(), we should check if this needs to be done when
going rw.

Also, add some sysfs code for debugging bucket invalidation.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/super.c

@@ -383,6 +383,7 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 	bch2_recalc_capacity(c);
 
 	bch2_do_discards(c);
+	bch2_do_invalidates(c);
 
 	if (!early) {
 		ret = bch2_fs_read_write_late(c);

fs/bcachefs/sysfs.c

@@ -154,6 +154,7 @@ do {									\
 
 write_attribute(trigger_gc);
 write_attribute(trigger_discards);
+write_attribute(trigger_invalidates);
 write_attribute(prune_cache);
 rw_attribute(btree_gc_periodic);
 rw_attribute(gc_gens_pos);
@@ -516,6 +517,9 @@ STORE(bch2_fs)
 	if (attr == &sysfs_trigger_discards)
 		bch2_do_discards(c);
 
+	if (attr == &sysfs_trigger_invalidates)
+		bch2_do_invalidates(c);
+
 #ifdef CONFIG_BCACHEFS_TESTS
 	if (attr == &sysfs_perf_test) {
 		char *tmp = kstrdup(buf, GFP_KERNEL), *p = tmp;
@@ -627,6 +631,7 @@ struct attribute *bch2_fs_internal_files[] = {
 
 	&sysfs_trigger_gc,
 	&sysfs_trigger_discards,
+	&sysfs_trigger_invalidates,
 	&sysfs_prune_cache,
 
 	&sysfs_read_realloc_races,
@@ -792,6 +797,7 @@ static void dev_alloc_debug_to_text(struct printbuf *out, struct bch_dev *ca)
 	       "open_buckets_wait\t%s\n"
 	       "open_buckets_btree\t%u\n"
 	       "open_buckets_user\t%u\n"
+	       "buckets_to_invalidate\t%llu\n"
 	       "btree reserve cache\t%u\n",
 	       stats.buckets_ec,
 	       c->freelist_wait.list.first		? "waiting" : "empty",
@@ -801,6 +807,7 @@ static void dev_alloc_debug_to_text(struct printbuf *out, struct bch_dev *ca)
 	       c->open_buckets_wait.list.first		? "waiting" : "empty",
 	       nr[BCH_DATA_btree],
 	       nr[BCH_DATA_user],
+	       should_invalidate_buckets(ca, stats),
 	       c->btree_reserve_cache_nr);
 }