From 0d3ce181e19a8433fa6995cdedd7d93d1bd3651c Mon Sep 17 00:00:00 2001
From: Zdenek Kabelac <zkabelac@redhat.com>
Date: Mon, 12 Mar 2012 14:40:41 +0000
Subject: [PATCH] Better structure layout for device_info

Save some relocation entries and use directly char[].
Since we do not need yes more then 127 partitions per device, use just int8_t.
Move lvm_type_filter_destroy into local static function.
---
 WHATS_NEW              |  1 +
 lib/device/dev-cache.h |  2 +-
 lib/filters/filter.c   | 38 +++++++++++++++++++-------------------
 lib/filters/filter.h   |  2 --
 4 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/WHATS_NEW b/WHATS_NEW
index 5f609624f..b39bc9d40 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.96 - 
 ================================
+  Better structure layout for device_info in dev_subsystem_name().
   Change message severity for creation of VG over uninitialised devices.
   Fix error path for failing toolcontext creation.
   Fix warn msg for thin pool chunk size and update man for chunksize (2.02.89).
diff --git a/lib/device/dev-cache.h b/lib/device/dev-cache.h
index 717fb6872..b684df611 100644
--- a/lib/device/dev-cache.h
+++ b/lib/device/dev-cache.h
@@ -25,8 +25,8 @@
 struct dev_filter {
 	int (*passes_filter) (struct dev_filter * f, struct device * dev);
 	void (*destroy) (struct dev_filter * f);
-	unsigned use_count;
 	void *private;
+	unsigned use_count;
 };
 
 /*
diff --git a/lib/filters/filter.c b/lib/filters/filter.c
index d8bc35904..aa1e89c37 100644
--- a/lib/filters/filter.c
+++ b/lib/filters/filter.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
- * Copyright (C) 2004-2011 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004-2012 Red Hat, Inc. All rights reserved.
  *
  * This file is part of LVM2.
  *
@@ -36,8 +36,8 @@ static struct {
 } _partitions[NUMBER_OF_MAJORS];
 
 typedef struct {
-	const char *name;
-	const int max_partitions;
+	const char name[15];
+	const int8_t max_partitions;
 } device_info_t;
 
 static int _md_major = -1;
@@ -107,7 +107,7 @@ const char *dev_subsystem_name(const struct device *dev)
  *
  * The list can be supplemented with devices/types in the config file.
  */
-static const device_info_t device_info[] = {
+static const device_info_t _device_info[] = {
 	{"ide", 64},		/* IDE disk */
 	{"sd", 16},		/* SCSI disk */
 	{"md", 1},		/* Multiple Disk driver (SoftRAID) */
@@ -136,7 +136,7 @@ static const device_info_t device_info[] = {
 	{"mmc", 16},		/* MMC block device */
 	{"blkext", 1},		/* Extended device partitions */
 	{"fio", 16},		/* Fusion */
-	{NULL, 0}
+	{"", 0}
 };
 
 static int _passes_lvm_type_device_filter(struct dev_filter *f __attribute__((unused)),
@@ -220,7 +220,7 @@ static int _scan_proc_dev(const char *proc, const struct dm_config_node *cn)
 		return 0;
 	}
 
-	while (fgets(line, 80, pd) != NULL) {
+	while (fgets(line, sizeof(line), pd) != NULL) {
 		i = 0;
 		while (line[i] == ' ')
 			i++;
@@ -269,13 +269,13 @@ static int _scan_proc_dev(const char *proc, const struct dm_config_node *cn)
 
 		/* Go through the valid device names and if there is a
 		   match store max number of partitions */
-		for (j = 0; device_info[j].name != NULL; j++) {
-			dev_len = strlen(device_info[j].name);
+		for (j = 0; _device_info[j].name[0]; j++) {
+			dev_len = strlen(_device_info[j].name);
 			if (dev_len <= strlen(line + i) &&
-			    !strncmp(device_info[j].name, line + i, dev_len) &&
+			    !strncmp(_device_info[j].name, line + i, dev_len) &&
 			    (line_maj < NUMBER_OF_MAJORS)) {
 				_partitions[line_maj].max_partitions =
-				    device_info[j].max_partitions;
+				    _device_info[j].max_partitions;
 				break;
 			}
 		}
@@ -342,6 +342,14 @@ int major_is_scsi_device(int major)
 	return (_partitions[major].flags & PARTITION_SCSI_DEVICE) ? 1 : 0;
 }
 
+static void _lvm_type_filter_destroy(struct dev_filter *f)
+{
+	if (f->use_count)
+		log_error(INTERNAL_ERROR "Destroying lvm_type filter while in use %u times.", f->use_count);
+
+	dm_free(f);
+}
+
 struct dev_filter *lvm_type_filter_create(const char *proc,
 					  const struct dm_config_node *cn)
 {
@@ -353,7 +361,7 @@ struct dev_filter *lvm_type_filter_create(const char *proc,
 	}
 
 	f->passes_filter = _passes_lvm_type_device_filter;
-	f->destroy = lvm_type_filter_destroy;
+	f->destroy = _lvm_type_filter_destroy;
 	f->use_count = 0;
 	f->private = NULL;
 
@@ -364,11 +372,3 @@ struct dev_filter *lvm_type_filter_create(const char *proc,
 
 	return f;
 }
-
-void lvm_type_filter_destroy(struct dev_filter *f)
-{
-	if (f->use_count)
-		log_error(INTERNAL_ERROR "Destroying lvm_type filter while in use %u times.", f->use_count);
-
-	dm_free(f);
-}
diff --git a/lib/filters/filter.h b/lib/filters/filter.h
index 21cb89bde..cdbcfe837 100644
--- a/lib/filters/filter.h
+++ b/lib/filters/filter.h
@@ -33,8 +33,6 @@
 struct dev_filter *lvm_type_filter_create(const char *proc,
 					  const struct dm_config_node *cn);
 
-void lvm_type_filter_destroy(struct dev_filter *f);
-
 int dm_major(void);
 int md_major(void);
 int blkext_major(void);