nilfs2: fix backing_dev_info reference leak

setup_bdev_super() already initializes sb->s_bdev and takes a
reference on the block device backing_dev_info when assigning sb->s_bdi.

nilfs_fill_super() takes another reference to the same
backing_dev_info and stores it in sb->s_bdi again. The extra
reference is not paired with a matching bdi_put(), since
generic_shutdown_super() releases sb->s_bdi only once.

Drop the redundant bdi_get() in nilfs_fill_super(). The single
reference taken by setup_bdev_super() is enough and is released
during superblock shutdown.

Fixes: c1e012ea9e83 ("nilfs2: use setup_bdev_super to de-duplicate the mount code")
Signed-off-by: Shuangpeng Bai <shuangpeng.kernel@gmail.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>

diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 7aa5ef8606cdd473ad6f43ac61e7a4910c19d954..893a504cb80c8a608f3f2f176b9a2af8614d2a8c 100644 (file)
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -1070,8 +1070,6 @@ nilfs_fill_super(struct super_block *sb, struct fs_context *fc)
        sb->s_time_gran = 1;
        sb->s_max_links = NILFS_LINK_MAX;
 
-       sb->s_bdi = bdi_get(sb->s_bdev->bd_disk->bdi);
-
        err = load_nilfs(nilfs, sb);
        if (err)
                goto failed_nilfs;