1 files changed, 39 insertions, 12 deletions

diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index dfeef583ee50..8ccbc8f3b3af 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -16,6 +16,22 @@
 #include <linux/sort.h>
 #include <linux/sched/clock.h>
 
+/* Default is -1; we skip past it for struct cached_dev's cache mode */
+static const char * const bch_cache_modes[] = {
+	"writethrough",
+	"writeback",
+	"writearound",
+	"none",
+	NULL
+};
+
+/* Default is -1; we skip past it for stop_when_cache_set_failed */
+static const char * const bch_stop_on_failure_modes[] = {
+	"auto",
+	"always",
+	NULL
+};
+
 static const char * const cache_replacement_policies[] = {
 	"lru",
 	"fifo",
@@ -114,6 +130,20 @@ rw_attribute(btree_shrinker_disabled);
 rw_attribute(copy_gc_enabled);
 rw_attribute(size);
 
+static ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
+			    size_t selected)
+{
+	char *out = buf;
+	size_t i;
+
+	for (i = 0; list[i]; i++)
+		out += snprintf(out, buf + size - out,
+				i == selected ? "[%s] " : "%s ", list[i]);
+
+	out[-1] = '\n';
+	return out - buf;
+}
+
 SHOW(__bch_cached_dev)
 {
 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
@@ -124,12 +154,12 @@ SHOW(__bch_cached_dev)
 
 	if (attr == &sysfs_cache_mode)
 		return bch_snprint_string_list(buf, PAGE_SIZE,
-					       bch_cache_modes + 1,
+					       bch_cache_modes,
 					       BDEV_CACHE_MODE(&dc->sb));
 
 	if (attr == &sysfs_stop_when_cache_set_failed)
 		return bch_snprint_string_list(buf, PAGE_SIZE,
-					       bch_stop_on_failure_modes + 1,
+					       bch_stop_on_failure_modes,
 					       dc->stop_when_cache_set_failed);
 
 
@@ -253,8 +283,7 @@ STORE(__cached_dev)
 		bch_cached_dev_run(dc);
 
 	if (attr == &sysfs_cache_mode) {
-		v = bch_read_string_list(buf, bch_cache_modes + 1);
-
+		v = __sysfs_match_string(bch_cache_modes, -1, buf);
 		if (v < 0)
 			return v;
 
@@ -265,8 +294,7 @@ STORE(__cached_dev)
 	}
 
 	if (attr == &sysfs_stop_when_cache_set_failed) {
-		v = bch_read_string_list(buf, bch_stop_on_failure_modes + 1);
-
+		v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
 		if (v < 0)
 			return v;
 
@@ -635,6 +663,7 @@ SHOW_LOCKED(bch_cache_set)
 STORE(__bch_cache_set)
 {
 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
+	ssize_t v;
 
 	if (attr == &sysfs_unregister)
 		bch_cache_set_unregister(c);
@@ -698,8 +727,7 @@ STORE(__bch_cache_set)
 		      c->congested_write_threshold_us);
 
 	if (attr == &sysfs_errors) {
-		ssize_t v = bch_read_string_list(buf, error_actions);
-
+		v = __sysfs_match_string(error_actions, -1, buf);
 		if (v < 0)
 			return v;
 
@@ -714,8 +742,7 @@ STORE(__bch_cache_set)
 		c->error_decay = strtoul_or_return(buf) / 88;
 
 	if (attr == &sysfs_io_disable) {
-		int v = strtoul_or_return(buf);
-
+		v = strtoul_or_return(buf);
 		if (v) {
 			if (test_and_set_bit(CACHE_SET_IO_DISABLE,
 					     &c->flags))
@@ -929,6 +956,7 @@ SHOW_LOCKED(bch_cache)
 STORE(__bch_cache)
 {
 	struct cache *ca = container_of(kobj, struct cache, kobj);
+	ssize_t v;
 
 	if (attr == &sysfs_discard) {
 		bool v = strtoul_or_return(buf);
@@ -943,8 +971,7 @@ STORE(__bch_cache)
 	}
 
 	if (attr == &sysfs_cache_replacement_policy) {
-		ssize_t v = bch_read_string_list(buf, cache_replacement_policies);
-
+		v = __sysfs_match_string(cache_replacement_policies, -1, buf);
 		if (v < 0)
 			return v;