From dff90d58a1c815b87b2603295382c97e78064349 Mon Sep 17 00:00:00 2001
From: Coly Li <colyli@suse.de>
Date: Fri, 28 Jun 2019 20:00:00 +0800
Subject: [PATCH] bcache: add reclaimed_journal_buckets to struct cache_set
Git-commit: dff90d58a1c815b87b2603295382c97e78064349
References: bsc#1140652
Patch-mainline: v5.3-rc1

Now we have counters for how many times jouranl is reclaimed, how many
times cached dirty btree nodes are flushed, but we don't know how many
jouranl buckets are really reclaimed.

This patch adds reclaimed_journal_buckets into struct cache_set, this
is an increasing only counter, to tell how many journal buckets are
reclaimed since cache set runs. From all these three counters (reclaim,
reclaimed_journal_buckets, flush_write), we can have idea how well
current journal space reclaim code works.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

---
 drivers/md/bcache/bcache.h  | 1 +
 drivers/md/bcache/journal.c | 1 +
 drivers/md/bcache/sysfs.c   | 5 +++++
 3 files changed, 7 insertions(+)

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 35396248a7d5..013e35a9e317 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -705,6 +705,7 @@ struct cache_set {
 	atomic_long_t		writeback_keys_failed;
 
 	atomic_long_t		reclaim;
+	atomic_long_t		reclaimed_journal_buckets;
 	atomic_long_t		flush_write;
 
 	enum			{
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 8bcd8f1bf8cb..be2a2a201603 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -614,6 +614,7 @@ static void journal_reclaim(struct cache_set *c)
 		k->ptr[n++] = MAKE_PTR(0,
 				  bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
 				  ca->sb.nr_this_dev);
+		atomic_long_inc(&c->reclaimed_journal_buckets);
 	}
 
 	if (n) {
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 701a386a954c..9f0826712845 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -82,6 +82,7 @@ read_attribute(bset_tree_stats);
 read_attribute(state);
 read_attribute(cache_read_races);
 read_attribute(reclaim);
+read_attribute(reclaimed_journal_buckets);
 read_attribute(flush_write);
 read_attribute(writeback_keys_done);
 read_attribute(writeback_keys_failed);
@@ -705,6 +706,9 @@ SHOW(__bch_cache_set)
 	sysfs_print(reclaim,
 		    atomic_long_read(&c->reclaim));
 
+	sysfs_print(reclaimed_journal_buckets,
+		    atomic_long_read(&c->reclaimed_journal_buckets));
+
 	sysfs_print(flush_write,
 		    atomic_long_read(&c->flush_write));
 
@@ -931,6 +935,7 @@ static struct attribute *bch_cache_set_internal_files[] = {
 	&sysfs_bset_tree_stats,
 	&sysfs_cache_read_races,
 	&sysfs_reclaim,
+	&sysfs_reclaimed_journal_buckets,
 	&sysfs_flush_write,
 	&sysfs_writeback_keys_done,
 	&sysfs_writeback_keys_failed,
-- 
2.16.4