ext4: fix possible leak of s_journal_flag_rwsem in error path

commit af18e35bfd01e6d65a5e3ef84ffe8b252d1628c5 upstream.

Fixes: c8585c6f ("ext4: fix races between changing inode journal ...")
Signed-off-by: NVasily Averin <vvs@virtuozzo.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # 4.7
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/ext4/super.c

@@ -4509,6 +4509,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
 	percpu_counter_destroy(&sbi->s_dirs_counter);
 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
+	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 failed_mount5:
 	ext4_ext_release(sb);
 	ext4_release_system_zone(sb);