From 381f32b1c5943afb35940b88c45c3fa4bf5fc1de Mon Sep 17 00:00:00 2001
From: Daniel Swarbrick <daniel.swarbrick@gmail.com>
Date: Fri, 18 Aug 2023 12:49:16 +0200
Subject: [PATCH] btrfs: close btrfs.FS handle after use

Despite being quite hard to provoke (< 10% in my testing), the btrfs
collector would occasionally leave stale FDs relating to btrfs
mountpoints, making the filesystems unable to be unmounted.

Fixes: #2772.

Signed-off-by: Daniel Swarbrick <daniel.swarbrick@gmail.com>
---
 collector/btrfs_linux.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/collector/btrfs_linux.go b/collector/btrfs_linux.go
index b5642b33..f1490541 100644
--- a/collector/btrfs_linux.go
+++ b/collector/btrfs_linux.go
@@ -135,6 +135,7 @@ func (c *btrfsCollector) getIoctlStats() (map[string]*btrfsIoctlFsStats, error)
 				"err", err)
 			continue
 		}
+		defer fs.Close()
 
 		fsInfo, err := fs.Info()
 		if err != nil {