bcache: use sysfs_strtoul_bool() to set bit-field variables

When setting bcache parameters via sysfs, there are some variables are
defined as bit-field value. Current bcache code in sysfs.c uses either
d_strtoul() or sysfs_strtoul() to convert the input string to unsigned
integer value and set it to the corresponded bit-field value.

The problem is, the bit-field value only takes the lowest bit of the
converted value. If input is 2, the expected value (like bool value)
of the bit-field value should be 1, but indeed it is 0.

The following sysfs files for bit-field variables have such problem,
	bypass_torture_test,	for dc->bypass_torture_test
	writeback_metadata,	for dc->writeback_metadata
	writeback_running,	for dc->writeback_running
	verify,			for c->verify
	key_merging_disabled,	for c->key_merging_disabled
	gc_always_rewrite,	for c->gc_always_rewrite
	btree_shrinker_disabled,for c->shrinker_disabled
	copy_gc_enabled,	for c->copy_gc_enabled

This patch uses sysfs_strtoul_bool() to set such bit-field variables,
then if the converted value is non-zero, the bit-field variables will
be set to 1, like setting a bool value like expensive_debug_checks.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/sysfs.c

@@ -277,9 +277,9 @@ STORE(__cached_dev)
 
 	sysfs_strtoul(data_csum,	dc->disk.data_csum);
 	d_strtoul(verify);
-	d_strtoul(bypass_torture_test);
-	d_strtoul(writeback_metadata);
-	d_strtoul(writeback_running);
+	sysfs_strtoul_bool(bypass_torture_test, dc->bypass_torture_test);
+	sysfs_strtoul_bool(writeback_metadata, dc->writeback_metadata);
+	sysfs_strtoul_bool(writeback_running, dc->writeback_running);
 	d_strtoul(writeback_delay);
 
 	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent,
@@ -816,12 +816,12 @@ STORE(__bch_cache_set)
 	}
 
 	sysfs_strtoul(journal_delay_ms,		c->journal_delay_ms);
-	sysfs_strtoul(verify,			c->verify);
-	sysfs_strtoul(key_merging_disabled,	c->key_merging_disabled);
+	sysfs_strtoul_bool(verify,		c->verify);
+	sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled);
 	sysfs_strtoul(expensive_debug_checks,	c->expensive_debug_checks);
-	sysfs_strtoul(gc_always_rewrite,	c->gc_always_rewrite);
-	sysfs_strtoul(btree_shrinker_disabled,	c->shrinker_disabled);
-	sysfs_strtoul(copy_gc_enabled,		c->copy_gc_enabled);
+	sysfs_strtoul_bool(gc_always_rewrite,	c->gc_always_rewrite);
+	sysfs_strtoul_bool(btree_shrinker_disabled, c->shrinker_disabled);
+	sysfs_strtoul_bool(copy_gc_enabled,	c->copy_gc_enabled);
 	/*
 	 * write gc_after_writeback here may overwrite an already set
 	 * BCH_DO_AUTO_GC, it doesn't matter because this flag will be