kdbus: when running in a container, don't complain that we cannot write to /sys

[elogind.git] / src / libsystemd / sd-bus / bus-kernel.c

diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
index 759d566eb31d9fc4d3c8a7fb33bcc3802a9c9310..84fb4bdf2b4af185c8ab6f0de7523c96d5a6ce79 100644 (file)
--- a/src/libsystemd/sd-bus/bus-kernel.c
+++ b/src/libsystemd/sd-bus/bus-kernel.c
@@ -1800,15 +1800,18 @@ int bus_kernel_realize_attach_flags(sd_bus *bus) {
 
 int bus_kernel_fix_attach_mask(void) {
         _cleanup_free_ char *mask = NULL;
-        uint64_t m = (uint32_t) -1;
+        uint64_t m = (uint64_t) -1;
         char buf[2+16+2];
         int r;
 
+        /* By default we don't want any kdbus metadata fields to be
+         * suppressed, hence we reset the kernel mask for it to
+         * (uint64_t) -1. This is overridable via a kernel command
+         * line option, however. */
+
         r = get_proc_cmdline_key("systemd.kdbus_attach_flags_mask=", &mask);
-        if (r < 0) {
-                log_warning_errno(-r, "Failed to read kernel command line: %m");
-                return r;
-        }
+        if (r < 0)
+                return log_warning_errno(r, "Failed to read kernel command line: %m");
 
         if (mask) {
                 const char *p = mask;
@@ -1822,10 +1825,10 @@ int bus_kernel_fix_attach_mask(void) {
 
         sprintf(buf, "0x%" PRIx64 "\n", m);
         r = write_string_file("/sys/module/kdbus/parameters/attach_flags_mask", buf);
-        if (r < 0) {
-                log_warning_errno(-r, "Failed to write kdbus attach mask: %m");
-                return r;
-        }
+        if (r < 0)
+                return log_full_errno(
+                                r == -EROFS ? LOG_DEBUG : LOG_WARNING, r,
+                                "Failed to write kdbus attach mask: %m");
 
         return 0;
 }