[PATCH REPOST] ext4: Destroy ext4_fc_dentry_cachep kmemcache on module removal.

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

The kmemcache for ext4_fc_dentry_cachep remains registered after module
removal.

Destroy ext4_fc_dentry_cachep kmemcache on module removal.

Fixes: aa75f4d3daaeb ("ext4: main fast-commit commit path")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Link: https://lore.kernel.org/r/20211110134640.lyku5vklvdndw6uk@linutronix.de
---
 fs/ext4/ext4.h        | 1 +
 fs/ext4/fast_commit.c | 5 +++++
 fs/ext4/super.c       | 2 ++
 3 files changed, 8 insertions(+)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 404dd50856e5d..af7088085d4e4 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2935,6 +2935,7 @@ bool ext4_fc_replay_check_excluded(struct super_block *sb, ext4_fsblk_t block);
 void ext4_fc_replay_cleanup(struct super_block *sb);
 int ext4_fc_commit(journal_t *journal, tid_t commit_tid);
 int __init ext4_fc_init_dentry_cache(void);
+void ext4_fc_destroy_dentry_cache(void);
 
 /* mballoc.c */
 extern const struct seq_operations ext4_mb_seq_groups_ops;
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 0f32b445582ab..4665508efd778 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -2192,3 +2192,8 @@ int __init ext4_fc_init_dentry_cache(void)
 
 	return 0;
 }
+
+void ext4_fc_destroy_dentry_cache(void)
+{
+	kmem_cache_destroy(ext4_fc_dentry_cachep);
+}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 4e33b5eca694d..71185a217d05b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -6649,6 +6649,7 @@ static int __init ext4_init_fs(void)
 out:
 	unregister_as_ext2();
 	unregister_as_ext3();
+	ext4_fc_destroy_dentry_cache();
 out05:
 	destroy_inodecache();
 out1:
@@ -6675,6 +6676,7 @@ static void __exit ext4_exit_fs(void)
 	unregister_as_ext2();
 	unregister_as_ext3();
 	unregister_filesystem(&ext4_fs_type);
+	ext4_fc_destroy_dentry_cache();
 	destroy_inodecache();
 	ext4_exit_mballoc();
 	ext4_exit_sysfs();
-- 
2.34.1