1 files changed, 56 insertions, 28 deletions

diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 225b15aa0340..150cf4f4cf74 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -130,8 +130,10 @@ 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)
+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;
@@ -148,7 +150,8 @@ SHOW(__bch_cached_dev)
 {
 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
 					     disk.kobj);
-	const char *states[] = { "no cache", "clean", "dirty", "inconsistent" };
+	char const *states[] = { "no cache", "clean", "dirty", "inconsistent" };
+	int wb = dc->writeback_running;
 
 #define var(stat)		(dc->stat)
 
@@ -170,7 +173,8 @@ SHOW(__bch_cached_dev)
 	var_printf(writeback_running,	"%i");
 	var_print(writeback_delay);
 	var_print(writeback_percent);
-	sysfs_hprint(writeback_rate,	dc->writeback_rate.rate << 9);
+	sysfs_hprint(writeback_rate,
+		     wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 : 0);
 	sysfs_hprint(io_errors,		atomic_read(&dc->io_errors));
 	sysfs_printf(io_error_limit,	"%i", dc->error_limit);
 	sysfs_printf(io_disable,	"%i", dc->io_disable);
@@ -188,15 +192,22 @@ SHOW(__bch_cached_dev)
 		char change[20];
 		s64 next_io;
 
-		bch_hprint(rate,	dc->writeback_rate.rate << 9);
-		bch_hprint(dirty,	bcache_dev_sectors_dirty(&dc->disk) << 9);
-		bch_hprint(target,	dc->writeback_rate_target << 9);
-		bch_hprint(proportional,dc->writeback_rate_proportional << 9);
-		bch_hprint(integral,	dc->writeback_rate_integral_scaled << 9);
-		bch_hprint(change,	dc->writeback_rate_change << 9);
-
-		next_io = div64_s64(dc->writeback_rate.next - local_clock(),
-				    NSEC_PER_MSEC);
+		/*
+		 * Except for dirty and target, other values should
+		 * be 0 if writeback is not running.
+		 */
+		bch_hprint(rate,
+			   wb ? atomic_long_read(&dc->writeback_rate.rate) << 9
+			      : 0);
+		bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9);
+		bch_hprint(target, dc->writeback_rate_target << 9);
+		bch_hprint(proportional,
+			   wb ? dc->writeback_rate_proportional << 9 : 0);
+		bch_hprint(integral,
+			   wb ? dc->writeback_rate_integral_scaled << 9 : 0);
+		bch_hprint(change, wb ? dc->writeback_rate_change << 9 : 0);
+		next_io = wb ? div64_s64(dc->writeback_rate.next-local_clock(),
+					 NSEC_PER_MSEC) : 0;
 
 		return sprintf(buf,
 			       "rate:\t\t%s/sec\n"
@@ -255,8 +266,19 @@ STORE(__cached_dev)
 
 	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, 0, 40);
 
-	sysfs_strtoul_clamp(writeback_rate,
-			    dc->writeback_rate.rate, 1, INT_MAX);
+	if (attr == &sysfs_writeback_rate) {
+		ssize_t ret;
+		long int v = atomic_long_read(&dc->writeback_rate.rate);
+
+		ret = strtoul_safe_clamp(buf, v, 1, INT_MAX);
+
+		if (!ret) {
+			atomic_long_set(&dc->writeback_rate.rate, v);
+			ret = size;
+		}
+
+		return ret;
+	}
 
 	sysfs_strtoul_clamp(writeback_rate_update_seconds,
 			    dc->writeback_rate_update_seconds,
@@ -287,7 +309,7 @@ STORE(__cached_dev)
 		if (v < 0)
 			return v;
 
-		if ((unsigned) v != BDEV_CACHE_MODE(&dc->sb)) {
+		if ((unsigned int) v != BDEV_CACHE_MODE(&dc->sb)) {
 			SET_BDEV_CACHE_MODE(&dc->sb, v);
 			bch_write_bdev_super(dc, NULL);
 		}
@@ -321,8 +343,9 @@ STORE(__cached_dev)
 		add_uevent_var(env, "DRIVER=bcache");
 		add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid),
 		add_uevent_var(env, "CACHED_LABEL=%s", buf);
-		kobject_uevent_env(
-			&disk_to_dev(dc->disk.disk)->kobj, KOBJ_CHANGE, env->envp);
+		kobject_uevent_env(&disk_to_dev(dc->disk.disk)->kobj,
+				   KOBJ_CHANGE,
+				   env->envp);
 		kfree(env);
 	}
 
@@ -338,8 +361,8 @@ STORE(__cached_dev)
 			if (!v)
 				return size;
 		}
-
-		pr_err("Can't attach %s: cache set not found", buf);
+		if (v == -ENOENT)
+			pr_err("Can't attach %s: cache set not found", buf);
 		return v;
 	}
 
@@ -439,6 +462,7 @@ STORE(__bch_flash_dev)
 
 	if (attr == &sysfs_size) {
 		uint64_t v;
+
 		strtoi_h_or_return(buf, v);
 
 		u->sectors = v >> 9;
@@ -513,9 +537,9 @@ static int bch_bset_print_stats(struct cache_set *c, char *buf)
 			op.stats.floats, op.stats.failed);
 }
 
-static unsigned bch_root_usage(struct cache_set *c)
+static unsigned int bch_root_usage(struct cache_set *c)
 {
-	unsigned bytes = 0;
+	unsigned int bytes = 0;
 	struct bkey *k;
 	struct btree *b;
 	struct btree_iter iter;
@@ -550,9 +574,9 @@ static size_t bch_cache_size(struct cache_set *c)
 	return ret;
 }
 
-static unsigned bch_cache_max_chain(struct cache_set *c)
+static unsigned int bch_cache_max_chain(struct cache_set *c)
 {
-	unsigned ret = 0;
+	unsigned int ret = 0;
 	struct hlist_head *h;
 
 	mutex_lock(&c->bucket_lock);
@@ -560,7 +584,7 @@ static unsigned bch_cache_max_chain(struct cache_set *c)
 	for (h = c->bucket_hash;
 	     h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
 	     h++) {
-		unsigned i = 0;
+		unsigned int i = 0;
 		struct hlist_node *p;
 
 		hlist_for_each(p, h)
@@ -573,13 +597,13 @@ static unsigned bch_cache_max_chain(struct cache_set *c)
 	return ret;
 }
 
-static unsigned bch_btree_used(struct cache_set *c)
+static unsigned int bch_btree_used(struct cache_set *c)
 {
 	return div64_u64(c->gc_stats.key_bytes * 100,
 			 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
 }
 
-static unsigned bch_average_key_size(struct cache_set *c)
+static unsigned int bch_average_key_size(struct cache_set *c)
 {
 	return c->gc_stats.nkeys
 		? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
@@ -683,6 +707,7 @@ STORE(__bch_cache_set)
 	if (attr == &sysfs_flash_vol_create) {
 		int r;
 		uint64_t v;
+
 		strtoi_h_or_return(buf, v);
 
 		r = bch_flash_dev_create(c, v);
@@ -716,6 +741,7 @@ STORE(__bch_cache_set)
 
 	if (attr == &sysfs_prune_cache) {
 		struct shrink_control sc;
+
 		sc.gfp_mask = GFP_KERNEL;
 		sc.nr_to_scan = strtoul_or_return(buf);
 		c->shrink.scan_objects(&c->shrink, &sc);
@@ -769,12 +795,14 @@ STORE_LOCKED(bch_cache_set)
 SHOW(bch_cache_set_internal)
 {
 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
+
 	return bch_cache_set_show(&c->kobj, attr, buf);
 }
 
 STORE(bch_cache_set_internal)
 {
 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
+
 	return bch_cache_set_store(&c->kobj, attr, buf, size);
 }
 
@@ -976,7 +1004,7 @@ STORE(__bch_cache)
 		if (v < 0)
 			return v;
 
-		if ((unsigned) v != CACHE_REPLACEMENT(&ca->sb)) {
+		if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) {
 			mutex_lock(&ca->set->bucket_lock);
 			SET_CACHE_REPLACEMENT(&ca->sb, v);
 			mutex_unlock(&ca->set->bucket_lock);