From 77969722aaef10d9dd8fc13569f9a6d45c1a577e Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 1 Mar 2017 16:25:08 +0100
Subject: [PATCH] core: when a unit's SourcePath points to API VFS pretend we
 are never out-of-date (#5487)

If the unit's SourcePath is below /proc then it's a unit genreated from
a kernel resource (such as a .mount or .swap unit). And those we watch
anyway, and hence should never be out-of-date.

Fixes: #5461
---
 src/core/unit.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/core/unit.c b/src/core/unit.c
index b091a0999b8..f76b6c30a83 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -3154,6 +3154,11 @@ static bool fragment_mtime_newer(const char *path, usec_t mtime, bool path_maske
         if (!path)
                 return false;
 
+        /* If the source is some virtual kernel file system, then we assume we watch it anyway, and hence pretend we
+         * are never out-of-date. */
+        if (PATH_STARTSWITH_SET(path, "/proc", "/sys"))
+                return false;
+
         if (stat(path, &st) < 0)
                 /* What, cannot access this anymore? */
                 return true;