manager: do not append '\n' when writing sysctl settings

When booting with debug logs, we print:

   Setting '/proc/sys/fs/file-max' to '9223372036854775807
   '
   Setting '/proc/sys/fs/nr_open' to '2147483640
   '
   Couldn't write fs.nr_open as 2147483640, halving it.
   Setting '/proc/sys/fs/nr_open' to '1073741816
   '
   Successfully bumped fs.nr_open to 1073741816

The strange formatting is because we explicitly appended a newline in those two
places. It seems that the kernel doesn't care. In fact, we have a few dozen other
writes to sysctl where we don't append a newline. So let's just drop those here
too, to make the code a bit simpler and avoid strange output in the logs.

diff --git a/src/core/main.c b/src/core/main.c
index 119c518664ff78877bebd87a4a055ae11e2d7971..ffe5c1688aaa9ff575aa115a9d43c2ba1f27f205 100644 (file)
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -1184,9 +1184,10 @@ static void bump_file_max_and_nr_open(void) {
 #if BUMP_PROC_SYS_FS_FILE_MAX
         /* The maximum the kernel allows for this since 5.2 is LONG_MAX, use that. (Previously things were
          * different, but the operation would fail silently.) */
-        r = sysctl_writef("fs/file-max", "%li\n", LONG_MAX);
+        r = sysctl_writef("fs/file-max", "%li", LONG_MAX);
         if (r < 0)
-                log_full_errno(IN_SET(r, -EROFS, -EPERM, -EACCES) ? LOG_DEBUG : LOG_WARNING, r, "Failed to bump fs.file-max, ignoring: %m");
+                log_full_errno(IN_SET(r, -EROFS, -EPERM, -EACCES) ? LOG_DEBUG : LOG_WARNING,
+                               r, "Failed to bump fs.file-max, ignoring: %m");
 #endif
 
 #if BUMP_PROC_SYS_FS_NR_OPEN
@@ -1218,7 +1219,7 @@ static void bump_file_max_and_nr_open(void) {
                         break;
                 }
 
-                r = sysctl_writef("fs/nr_open", "%i\n", v);
+                r = sysctl_writef("fs/nr_open", "%i", v);
                 if (r == -EINVAL) {
                         log_debug("Couldn't write fs.nr_open as %i, halving it.", v);
                         v /= 2;