From: Tiago Salem Herrmann <therrmann@suse.com>
Date: Tue, 12 Dec 2017 15:52:45 +0000 (-0200)
Subject: sysctl: disable buffer while writing to /proc
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=61837b944ab30193dbcb286b95470771efba82b2;p=elogind.git

sysctl: disable buffer while writing to /proc

fputs() writes only first 2048 bytes and fails
to write to /proc when values are larger than that.
This patch adds a new flag to WriteStringFileFlags
that make it possible to disable the buffer under
specific cases.
---

diff --git a/src/basic/fileio.c b/src/basic/fileio.c
index 3c2f9742e..2f9d47019 100644
--- a/src/basic/fileio.c
+++ b/src/basic/fileio.c
@@ -166,6 +166,9 @@ int write_string_file_ts(
                 }
         }
 
+        if (flags & WRITE_STRING_FILE_DISABLE_BUFFER)
+                setvbuf(f, NULL, _IONBF, 0);
+
         r = write_string_stream_ts(f, line, flags, ts);
         if (r < 0)
                 goto fail;
diff --git a/src/basic/fileio.h b/src/basic/fileio.h
index d90fa4836..08423c1c9 100644
--- a/src/basic/fileio.h
+++ b/src/basic/fileio.h
@@ -34,6 +34,7 @@ typedef enum {
         WRITE_STRING_FILE_AVOID_NEWLINE     = 1<<2,
         WRITE_STRING_FILE_VERIFY_ON_FAILURE = 1<<3,
         WRITE_STRING_FILE_SYNC              = 1<<4,
+        WRITE_STRING_FILE_DISABLE_BUFFER    = 1<<5,
 
         /* And before you wonder, why write_string_file_atomic_label_ts() is a separate function instead of just one
            more flag here: it's about linking: we don't want to pull -lselinux into all users of write_string_file()