LVM2 ./WHATS_NEW_DM libdm/libdm-string.c

LVM2 ./WHATS_NEW_DM libdm/libdm-string.c

[zkabelac]

CVSROOT:	/cvs/lvm2
Module name:	LVM2
Changes by:	zkabelac@sourceware.org	2012-02-10 13:56:20

Modified files:
	.              : WHATS_NEW_DM 
	libdm          : libdm-string.c 

Log message:
	Return error for failing allocation
	
	Fix case, where final strdup would have failed and it would miss to return
	failure for this case and return success and NULL pointer.

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW_DM.diff?cvsroot=lvm2&r1=1.544&r2=1.545
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/libdm/libdm-string.c.diff?cvsroot=lvm2&r1=1.17&r2=1.18

--- LVM2/WHATS_NEW_DM	2012/02/10 13:52:05	1.544
+++ LVM2/WHATS_NEW_DM	2012/02/10 13:56:19	1.545
@@ -1,5 +1,6 @@
 Version 1.02.70 - 
 ===================================
+  Return error for failing allocation in dm_asprintf().
   Add missing test for failing allocation in dm_realloc() code.
   Add test for memory allocation failures in regex matcher code.
   Simplify dm_task_set_geometry() and use dm_asprintf().
--- LVM2/libdm/libdm-string.c	2011/09/14 16:07:07	1.17
+++ LVM2/libdm/libdm-string.c	2012/02/10 13:56:20	1.18
@@ -156,7 +156,9 @@
 		}
 	}
 
-	*result = dm_strdup(buf);
+	if (!(*result = dm_strdup(buf)))
+		n = -2; /* return -1 */
+
 	dm_free(buf);
 	return n + 1;
 }

LVM2 ./WHATS_NEW_DM libdm/libdm-string.c

[zkabelac]

CVSROOT:	/cvs/lvm2
Module name:	LVM2
Changes by:	zkabelac@sourceware.org	2012-02-23 18:05:13

Modified files:
	.              : WHATS_NEW_DM 
	libdm          : libdm-string.c 

Log message:
	Limit number of mem allocs and copies
	
	If we have good enough glibc to return number of needed chars, do not
	loop try to reach good size, but use this size directly for allocation,
	saving also last strdup.
	
	Since now we start with 16 bytes - skip buffer realloc for shorter string.

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW_DM.diff?cvsroot=lvm2&r1=1.570&r2=1.571
http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/libdm/libdm-string.c.diff?cvsroot=lvm2&r1=1.18&r2=1.19

--- LVM2/WHATS_NEW_DM	2012/02/20 21:11:06	1.570
+++ LVM2/WHATS_NEW_DM	2012/02/23 18:05:12	1.571
@@ -1,5 +1,6 @@
 Version 1.02.72 - 
 ====================================
+  Avoid memory reallocation for dm_asprintf.
 
 Version 1.02.71 - 20th February 2012
 ====================================
--- LVM2/libdm/libdm-string.c	2012/02/10 13:56:20	1.18
+++ LVM2/libdm/libdm-string.c	2012/02/23 18:05:12	1.19
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006-2007 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2006-2012 Red Hat, Inc. All rights reserved.
  *
  * This file is part of the device-mapper userspace tools.
  *
@@ -131,7 +131,7 @@
 
 int dm_asprintf(char **result, const char *format, ...)
 {
-	int n, ok = 0, size = 32;
+	int i, n, size = 16;
 	va_list ap;
 	char *buf = dm_malloc(size);
 
@@ -140,26 +140,30 @@
 	if (!buf)
 		return -1;
 
-	while (!ok) {
+	for (i = 0;; i++) {
 		va_start(ap, format);
 		n = vsnprintf(buf, size, format, ap);
 		va_end(ap);
 
 		if (0 <= n && n < size)
-			ok = 1;
-		else {
-			dm_free(buf);
-			size *= 2;
-			buf = dm_malloc(size);
-			if (!buf)
-				return -1;
-		}
+			break;
+
+		dm_free(buf);
+		/* Up to glibc 2.0.6 returns -1 */
+		size = (n < 0) ? size * 2 : n + 1;
+		if (!(buf = dm_malloc(size)))
+			return -1;
 	}
 
-	if (!(*result = dm_strdup(buf)))
-		n = -2; /* return -1 */
+	if (i > 1) {
+		/* Reallocating more then once? */
+		if (!(*result = dm_strdup(buf))) {
+			dm_free(buf);
+			return -1;
+		}
+	} else
+		*result = buf;
 
-	dm_free(buf);
 	return n + 1;
 }