Move busy detection of SWRaid members into the new module (#756829)

Add active attribute to the cache of SWRaid members.  Move parsing of
/proc/mdstat to discover busy SWRaid members into the cache loading
code.  New parsing code is a little different because it is finding all
members of active arrays rather than determining if a specific member is
active.

Bug 756829 - SWRaid member detection enhancements

include/SWRaid_Info.h

@@ -30,18 +30,26 @@
 namespace GParted
 {
 
+struct SWRaid_Member
+{
+	Glib::ustring member;
+	bool          active;
+};
+
 class SWRaid_Info
 {
 public:
 	static void load_cache();
 	static bool is_member( const Glib::ustring & member_path );
+	static bool is_member_active( const Glib::ustring & member_path );
 
 private:
 	static void set_command_found();
 	static void load_swraid_info_cache();
+	static SWRaid_Member & get_cache_entry_by_member( const Glib::ustring & member_path );
 
 	static bool mdadm_found;
-	static std::vector<Glib::ustring> swraid_info_cache;
+	static std::vector<SWRaid_Member> swraid_info_cache;
 };
 
 }//GParted

include/Utils.h

@@ -181,7 +181,6 @@ public:
 	static Glib::ustring get_filesystem_software( FILESYSTEM filesystem ) ;
 	static bool kernel_supports_fs( const Glib::ustring & fs ) ;
 	static bool kernel_version_at_least( int major_ver, int minor_ver, int patch_ver ) ;
-	static bool swraid_member_is_active( const Glib::ustring & path ) ;
 	static Glib::ustring format_size( Sector sectors, Byte_Value sector_size ) ;
 	static Glib::ustring format_time( std::time_t seconds ) ;
 	static double sector_to_unit( Sector sectors, Byte_Value sector_size, SIZE_UNIT size_unit ) ;

src/GParted_Core.cc

@@ -1857,7 +1857,7 @@ bool GParted_Core::is_busy( FILESYSTEM fstype, const Glib::ustring & path )
 		busy = is_dev_mounted( path ) ;
 
 		//Custom checks for recognised but other not-supported file system types
-		busy |= ( fstype == FS_LINUX_SWRAID && Utils::swraid_member_is_active( path ) ) ;
+		busy |= ( fstype == FS_LINUX_SWRAID && SWRaid_Info::is_member_active( path ) );
 	}
 
 	return busy ;

src/SWRaid_Info.cc

@@ -19,19 +19,25 @@
 #include "../include/Utils.h"
 
 #include <glibmm/ustring.h>
+#include <fstream>
 
 namespace GParted
 {
 
 // Data model:
 // mdadm_found       - Is the "mdadm" command available?
-// swraid_info_cache - Vector of /dev entries of members in Linux Software RAID arrays.
+// swraid_info_cache - Vector of member information in Linux Software RAID arrays.
 //                     E.g.
-//                     ["/dev/sda1", "/dev/sda2", ...]
+//                     //member     , active
+//                     [{"/dev/sda1", true },
+//                      {"/dev/sda2", true },
+//                      {"/dev/sda6", false},
+//                      {"/dev/sdb6", false}
+//                     ]
 
 // Initialise static data elements
 bool SWRaid_Info::mdadm_found = false;
-std::vector<Glib::ustring> SWRaid_Info::swraid_info_cache;
+std::vector<SWRaid_Member> SWRaid_Info::swraid_info_cache;
 
 void SWRaid_Info::load_cache()
 {
@@ -41,13 +47,22 @@ void SWRaid_Info::load_cache()
 
 bool SWRaid_Info::is_member( const Glib::ustring & member_path )
 {
-	for ( unsigned int i = 0 ; i < swraid_info_cache.size() ; i ++ )
-		if ( member_path == swraid_info_cache[i] )
+	const SWRaid_Member & memb = get_cache_entry_by_member( member_path );
+	if ( memb.member == member_path )
 		return true;
 
 	return false;
 }
 
+bool SWRaid_Info::is_member_active( const Glib::ustring & member_path )
+{
+	const SWRaid_Member & memb = get_cache_entry_by_member( member_path );
+	if ( memb.member == member_path )
+		return memb.active;
+
+	return false;  // No such member
+}
+
 // Private methods
 
 void SWRaid_Info::set_command_found()
@@ -113,12 +128,67 @@ void SWRaid_Info::load_swraid_info_cache()
 				std::vector<Glib::ustring> devices;
 				Utils::split( devices_str, devices, "," );
 				for ( unsigned int j = 0 ; j < devices.size() ; j ++ )
-					swraid_info_cache.push_back( devices[j] );
+				{
+					SWRaid_Member memb;
+					memb.member = devices[j];
+					memb.active = false;
+					swraid_info_cache.push_back( memb );
+				}
 			}
 			else
 				line_type = LINE_TYPE_OTHER;
 		}
 	}
+
+	// Set which SWRaid members are active.
+	std::string line;
+	std::ifstream input( "/proc/mdstat" );
+	if ( input )
+	{
+		// Read /proc/mdstat extracting members for active arrays, marking them
+		// active in the cache.  Example fragment of /proc/mdstat:
+		//     md1 : active raid1 sdb1[0] sdb2[1]
+		//           1047552 blocks super 1.2 [2/2] [UU]
+		while ( getline( input, line ) )
+		{
+			if ( line.find( " : active " ) != std::string::npos )
+			{
+				// Found a line for an active array.  Split into space
+				// separated fields.
+				std::vector<Glib::ustring> fields;
+				Utils::tokenize( line, fields, " " );
+				for ( unsigned int i = 0 ; i < fields.size() ; i ++ )
+				{
+					Glib::ustring::size_type index = fields[i].find( "[" );
+					if ( index != Glib::ustring::npos )
+					{
+						// Field contains an "[" so got a short
+						// kernel device name of a member.  Mark
+						// as active.
+						Glib::ustring mpath = "/dev/" +
+						                      fields[i].substr( 0, index );
+						SWRaid_Member & memb = get_cache_entry_by_member( mpath );
+						if ( memb.member == mpath )
+							memb.active = true;
+					}
+				}
+			}
+		}
+		input.close();
+	}
+}
+
+// Perform linear search of the cache to find the matching member.
+// Returns found cache entry or not found substitute.
+SWRaid_Member & SWRaid_Info::get_cache_entry_by_member( const Glib::ustring & member_path )
+{
+	for ( unsigned int i = 0 ; i < swraid_info_cache.size() ; i ++ )
+	{
+		if ( member_path == swraid_info_cache[i].member )
+			return swraid_info_cache[i];
+	}
+	static SWRaid_Member memb = {"", false};
+	return memb;
 }
 
 } //GParted

src/Utils.cc

@@ -401,39 +401,6 @@ bool Utils::kernel_version_at_least( int major_ver, int minor_ver, int patch_ver
 	return result ;
 }
 
-//Report whether the device is an active member of a Linux Software RAID array
-bool Utils::swraid_member_is_active( const Glib::ustring & path )
-{
-	//Read /proc/mdstat and look for the device name on an active RAID array
-	//  line.   Example line: "md1 : active raid1 sda1[2] sdb1[3]"
-	//                                           ^^^^^^
-	//                                           needle
-	//  Strip "/dev/" prefix and search for device name with surrounding
-	//  " " and "[" to avoid substring matches.
-	if ( path .substr( 0, 5 ) != "/dev/" )
-		return false ;
-
-	bool member_active = false ;
-	Glib::ustring needle = " " + path .substr( 5 ) + "[" ;
-	std::string line ;
-	std::ifstream input( "/proc/mdstat" ) ;
-	if ( input )
-	{
-		while ( getline( input, line ) )
-		{
-			if (    line .find( " : active " ) != std::string::npos
-			     && line .find( needle ) != std::string::npos       )
-			{
-				member_active = true ;
-				break ;
-			}
-		}
-		input .close() ;
-	}
-
-	return member_active ;
-}
-
 Glib::ustring Utils::format_size( Sector sectors, Byte_Value sector_size )
 {
 	std::stringstream ss ;