From: Ondrej Kozina <okozina@redhat.com>
Date: Tue, 13 Aug 2013 09:02:51 +0000 (+0200)
Subject: - get version and related LVM2 capabilities only once
X-Git-Tag: v0.1.7~8^2~8
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a37e5e081580a2f8ce54814304d76562fe5b017a;p=thirdparty%2Fsnapper.git

- get version and related LVM2 capabilities only once
---

diff --git a/snapper/Lvm.cc b/snapper/Lvm.cc
index 443cdb85..6012c25e 100644
--- a/snapper/Lvm.cc
+++ b/snapper/Lvm.cc
@@ -58,7 +58,7 @@ namespace snapper
 
     Lvm::Lvm(const string& subvolume, const string& mount_type)
 	: Filesystem(subvolume), mount_type(mount_type),
-	version(getLvmVersion())
+	caps(LvmCapabilities::get_lvm_capabilities())
     {
 	if (access(LVCREATEBIN, X_OK) != 0)
 	{
@@ -75,12 +75,6 @@ namespace snapper
 	    throw ProgramNotInstalledException(LVCHANGEBIN " not installed");
 	}
 
-	if (!version.valid())
-	    y2war("Couldn't get proper LVM version");
-
-	if (version >= lvm_version(2, 2, 99))
-	    ignoreactivationskip = " -K";
-
 	bool found = false;
 	MtabData mtab_data;
 
@@ -331,7 +325,7 @@ namespace snapper
     void
     Lvm::activateSnapshot(const string& vg_name, const string& lv_name) const
     {
-	SystemCmd cmd(LVCHANGEBIN + ignoreactivationskip + " -ay " + quote(vg_name + "/" + lv_name));
+	SystemCmd cmd(LVCHANGEBIN + caps->get_ignoreactivationskip() + " -ay " + quote(vg_name + "/" + lv_name));
 	if (cmd.retcode() != 0)
 	{
 	    y2err("Couldn't activate snapshot " << vg_name << "/" << lv_name);
@@ -357,32 +351,41 @@ namespace snapper
     }
 
 
-    lvm_version
-    Lvm::getLvmVersion()
+    LvmCapabilities::LvmCapabilities()
+	: ignoreactivationskip(), time_support(false)
     {
-	uint16_t maj, min, rev;
-
 	SystemCmd cmd(string(LVSBIN " --version"));
 
 	if (cmd.retcode() != 0)
 	{
-	    return lvm_version::invalid_version();
+	    y2war("Couldn't get LVM version info");
 	}
 	else
 	{
 	    Regex rx(".*LVM[[:space:]]+version:[[:space:]]+([0-9]+)\\.([0-9]+)\\.([0-9]+).*$");
 
 	    if (!rx.match(cmd.getLine(0)))
-		return lvm_version::invalid_version();
+	    {
+		y2war("LVM version format didn't match");
+	    }
 	    else
 	    {
+		uint16_t maj, min, rev;
+
 		rx.cap(1) >> maj;
 		rx.cap(2) >> min;
 		rx.cap(3) >> rev;
+
+		lvm_version version(maj, min, rev);
+
+		if (version >= lvm_version(2,2,99))
+		{
+		    ignoreactivationskip = " -K";
+		}
+
+		time_support = (version >= lvm_version(2,2,88));
 	    }
 	}
-
-	return lvm_version(maj, min, rev);
     }
 
 
@@ -392,4 +395,31 @@ namespace snapper
 	return a.version >= b.version;
     }
 
+
+    LvmCapabilities*
+    LvmCapabilities::get_lvm_capabilities()
+    {
+	/*
+	 * NOTE: verify only one thread can access
+	 * 	 this section at the same time!
+	 */
+	static LvmCapabilities caps;
+
+	return &caps;
+    }
+
+
+    string
+    LvmCapabilities::get_ignoreactivationskip() const
+    {
+	return ignoreactivationskip;
+    }
+
+
+    bool
+    LvmCapabilities::get_time_support() const
+    {
+	return time_support;
+    }
+
 }
diff --git a/snapper/Lvm.h b/snapper/Lvm.h
index 3223e090..462236cb 100644
--- a/snapper/Lvm.h
+++ b/snapper/Lvm.h
@@ -23,6 +23,7 @@
 #ifndef SNAPPER_LVM_H
 #define SNAPPER_LVM_H
 
+#include <boost/noncopyable.hpp>
 
 #include "snapper/Filesystem.h"
 
@@ -43,19 +44,31 @@ namespace snapper
     };
 
 
-    class lvm_version
+    struct lvm_version
     {
-    public:
-	static lvm_version invalid_version() { return lvm_version(0, 0, 0); }
-
 	lvm_version(uint16_t maj, uint16_t min, uint16_t rev)
-	    : version(rev | ((uint32_t) min << 16) | ((uint64_t) maj << 32)) {}
+	    : version(rev | ((uint32_t)min << 16)  | ((uint64_t)maj << 32)) {}
+
+	const uint64_t version;
+    };
+
+    bool operator>=(const lvm_version& a, const lvm_version& b);
+
+    class LvmCapabilities : public boost::noncopyable
+    {
+    public:
+	static LvmCapabilities* get_lvm_capabilities();
 
-	bool valid() const { return version != 0; }
+	bool get_time_support() const;
+	string get_ignoreactivationskip() const;
 
-	friend bool operator>=(const lvm_version& a, const lvm_version& b);
     private:
-	const uint64_t version;
+	LvmCapabilities();
+
+	// empty or " -K" if lvm supports ignore activation skip flag
+	string ignoreactivationskip;
+	// true if lvm2 supports time info stored in metadata
+	bool time_support;
     };
 
 
@@ -89,10 +102,8 @@ namespace snapper
 
     private:
 
-	static lvm_version getLvmVersion();
-
 	const string mount_type;
-	const lvm_version version;
+	const LvmCapabilities* caps;
 
 	bool detectThinVolumeNames(const MtabData& mtab_data);
 	void activateSnapshot(const string& vg_name, const string& lv_name) const;
@@ -106,7 +117,6 @@ namespace snapper
 
 	vector<string> mount_options;
 
-	string ignoreactivationskip;
     };
 
 }