[PATCH] loadparm: Do not talloc empty params

[Volker Lendecke]

Hi!

Review appreciated!

Thanks, Volker

-- 
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-------------- next part --------------
From d79436f338f1693b0fc83210fc66c9672301bbcb Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl at samba.org>
Date: Thu, 26 Nov 2015 13:23:41 +0100
Subject: [PATCH] loadparm: Do not talloc empty params

Reduce memory footprint for large smb.conf files. With 1400 shares this
gets smbd -i from 7259kb to 3087kb according to 64-bit x86 massif. If
you want to serve 1000 clients, this saves you 4GB.

Signed-off-by: Volker Lendecke <vl at samba.org>
---
 lib/param/loadparm.c     | 15 ++++++++++-----
 source3/param/loadparm.c |  2 +-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/param/loadparm.c b/lib/param/loadparm.c
index 640c602..13ca2b5 100644
--- a/lib/param/loadparm.c
+++ b/lib/param/loadparm.c
@@ -128,7 +128,7 @@ static const char *lpcfg_string(const char *s)
 	standard_sub_basic(ret,len+100);
 	return (ret);
 #endif
-	return s;
+	return s ? s : "";
 }
 
 /*
@@ -876,11 +876,16 @@ void copy_service(struct loadparm_service *pserviceDest,
 					*(char *)dest_ptr = *(const char *)src_ptr;
 					break;
 
-				case P_STRING:
-					lpcfg_string_set(pserviceDest,
-						   (char **)dest_ptr,
-						   *(const char * const *)src_ptr);
+				case P_STRING: {
+					const char * const *src = (const char * const *)src_ptr;
+					char **dst = (char **)dest_ptr;
+					if ((*src == NULL) || (**src != '\0')) {
+						lpcfg_string_set(pserviceDest, dst, *src);
+					} else {
+						*dst = NULL;
+					}
 					break;
+				}
 
 				case P_USTRING:
 					lpcfg_string_set_upper(pserviceDest,
diff --git a/source3/param/loadparm.c b/source3/param/loadparm.c
index 9f40e65..7d734a4 100644
--- a/source3/param/loadparm.c
+++ b/source3/param/loadparm.c
@@ -962,7 +962,7 @@ char *lp_string(TALLOC_CTX *ctx, const char *s)
 	DEBUG(10, ("lp_string(%s)\n", s));
 #endif
 	if (!s) {
-		return NULL;
+		s = "";
 	}
 
 	ret = talloc_sub_basic(ctx,
-- 
1.9.1