From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 5 Apr 2022 21:34:44 +0000 (+0200)
Subject: loop-util: explicitly close loopback block device before sleeping
X-Git-Tag: v251-rc2~165^2~4
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=3e9210577dbe78b3c0cc9a8b0488c51f7339dd02;p=thirdparty%2Fsystemd.git

loop-util: explicitly close loopback block device before sleeping

attach_empty() file takes a BSD file lock on the device, and we really
should release that before going to sleep. hence explicitly close the
block device before the sleep instead of relying on _cleanup_ to close
it after the sleep.
---

diff --git a/src/shared/loop-util.c b/src/shared/loop-util.c
index 257af7340f0..073755fb9e2 100644
--- a/src/shared/loop-util.c
+++ b/src/shared/loop-util.c
@@ -561,6 +561,9 @@ static int loop_device_make_internal(
                 if (++n_attempts >= 64) /* Give up eventually */
                         return -EBUSY;
 
+                /* Now close the loop device explicitly. This will release any lock acquired by
+                 * attach_empty_file() or similar, while we sleep below. */
+                loop = safe_close(loop);
                 loopdev = mfree(loopdev);
 
                 /* Wait some random time, to make collision less likely. Let's pick a random time in the