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gparted/src/btrfs.cc

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/* Copyright (C) 2009,2010 Luca Bruno <lucab@debian.org>
* Copyright (C) 2010, 2011 Curtis Gedak
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "btrfs.h"
#include "BlockSpecial.h"
#include "FileSystem.h"
#include "Mount_Info.h"
#include "Partition.h"
#include <ctype.h>
#include <glibmm/miscutils.h>
#include <glibmm/shell.h>
namespace GParted
{
// Cache of required btrfs file system device information by device
// E.g. For a single device btrfs on /dev/sda2 and a three device btrfs
// on /dev/sd[bcd]1 the cache would be as follows. (Note that
// BS(str) is short hand for constructor BlockSpecial(str)).
// btrfs_device_cache[BS("/dev/sda2")] = {devid=1, members=[BS("/dev/sda2")]}
// btrfs_device_cache[BS("/dev/sdb1")] = {devid=1, members=[BS("/dev/sdd1"), BS("/dev/sdc1"), BS("/dev/sdb1")]}
// btrfs_device_cache[BS("/dev/sdc1")] = {devid=2, members=[BS("/dev/sdd1"), BS("/dev/sdc1"), BS("/dev/sdb1")]}
// btrfs_device_cache[BS("/dev/sdd1")] = {devid=3, members=[BS("/dev/sdd1"), BS("/dev/sdc1"), BS("/dev/sdb1")]}
std::map<BlockSpecial, BTRFS_Device> btrfs_device_cache;
FS btrfs::get_filesystem_support()
{
FS fs( FS_BTRFS );
fs .busy = FS::EXTERNAL ;
if ( ! Glib::find_program_in_path( "mkfs.btrfs" ) .empty() )
{
fs.create = FS::EXTERNAL;
fs.create_with_label = FS::EXTERNAL;
}
if (! Glib::find_program_in_path("btrfs").empty())
{
// Use these btrfs multi-tool sub-commands without further checking for
// their availability:
// btrfs check
// btrfs filesystem label
// btrfs filesystem resize
// btrfs filesystem show
// as they are all available in btrfs-progs >= 3.12.
fs.read = FS::EXTERNAL;
fs .read_label = FS::EXTERNAL ;
fs .read_uuid = FS::EXTERNAL ;
fs.check = FS::EXTERNAL;
fs.write_label = FS::EXTERNAL;
//Resizing of btrfs requires mount, umount and kernel
// support as well as btrfs filesystem resize
if ( ! Glib::find_program_in_path( "mount" ) .empty()
&& ! Glib::find_program_in_path( "umount" ) .empty()
&& fs .check
&& Utils::kernel_supports_fs( "btrfs" )
)
{
fs .grow = FS::EXTERNAL ;
if ( fs .read ) //needed to determine a minimum file system size.
fs .shrink = FS::EXTERNAL ;
}
}
if ( ! Glib::find_program_in_path( "btrfstune" ).empty() )
{
Utils::execute_command( "btrfstune --help", output, error, true );
if ( Utils::regexp_label( output + error, "^[[:blank:]]*(-u)[[:blank:]]" ) == "-u" )
fs.write_uuid = FS::EXTERNAL;
}
if ( fs .check )
{
fs.copy = FS::GPARTED;
fs.move = FS::GPARTED;
}
fs .online_read = FS::EXTERNAL ;
#ifdef ENABLE_ONLINE_RESIZE
if ( Utils::kernel_version_at_least( 3, 6, 0 ) )
{
fs .online_grow = fs .grow ;
fs .online_shrink = fs .shrink ;
}
#endif
fs_limits.min_size = 256 * MEBIBYTE;
return fs ;
}
bool btrfs::is_busy( const Glib::ustring & path )
{
//A btrfs file system is busy if any of the member devices are mounted.
// WARNING:
// Removal of the mounting device from a btrfs file system makes it impossible to
// determine whether the file system is mounted or not for linux <= 3.4. This is
// because /proc/mounts continues to show the old device which is no longer a
// member of the file system. Fixed in linux 3.5 by commit:
// Btrfs: implement ->show_devname
// https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=9c5085c147989d48dfe74194b48affc23f376650
return ! get_mount_device( path ) .empty() ;
}
bool btrfs::create( const Partition & new_partition, OperationDetail & operationdetail )
{
return ! execute_command( "mkfs.btrfs -L " + Glib::shell_quote( new_partition.get_filesystem_label() ) +
" " + Glib::shell_quote( new_partition.get_path() ),
operationdetail, EXEC_CHECK_STATUS );
}
bool btrfs::check_repair( const Partition & partition, OperationDetail & operationdetail )
{
return ! execute_command("btrfs check " + Glib::shell_quote(partition.get_path()),
operationdetail, EXEC_CHECK_STATUS);
}
void btrfs::set_used_sectors( Partition & partition )
{
//Called when the file system is unmounted *and* when mounted.
//
// Btrfs has a volume manager layer within the file system which allows it to
// provide multiple levels of data redundancy, RAID levels, and use multiple
// devices both of which can be changed while the file system is mounted. To
// achieve this btrfs has to allocate space at two different levels: (1) chunks
// of 256 MiB or more at the volume manager level; and (2) extents at the file
// data level.
// References:
// * Btrfs: Working with multiple devices
// https://lwn.net/Articles/577961/
// * Btrfs wiki: Glossary
// https://btrfs.wiki.kernel.org/index.php/Glossary
//
// This makes the question of how much disk space is being used in an individual
// device a complicated question to answer. Further, the current btrfs tools
// don't provide the required information.
//
// Btrfs filesystem show only provides space usage information at the chunk level
// per device. At the file extent level only a single figure for the whole file
// system is provided. It also reports size of the data and metadata being
// stored, not the larger figure of the amount of space taken after redundancy is
// applied. So it is impossible to answer the question of how much disk space is
// being used in an individual device. Example output:
//
// Label: none uuid: 36eb51a2-2927-4c92-820f-b2f0b5cdae50
// Total devices 2 FS bytes used 156.00KB
// devid 2 size 2.00GB used 512.00MB path /dev/sdb2
// devid 1 size 2.00GB used 240.75MB path /dev/sdb1
//
// Guesstimate the per device used figure as the fraction of the file system wide
// extent usage based on chunk usage per device.
//
// Positives:
// 1) Per device used figure will correctly be between zero and allocated chunk
// size.
//
// Known inaccuracies:
// [for single and multi-device btrfs file systems]
// 1) Btrfs filesystem show reports file system wide file extent usage without
// considering redundancy applied to that data. (By default btrfs stores two
// copies of metadata and one copy of data).
// 2) At minimum size when all data has been consolidated there will be a few
// partly filled chunks of 256 MiB or more for data and metadata of each
// storage profile (RAID level).
// [for multi-device btrfs file systems only]
// 3) Data may be far from evenly distributed between the chunks on multiple
// devices.
// 4) Extents can be and are relocated to other devices within the file system
// when shrinking a device.
Utils::execute_command("btrfs filesystem show " + Glib::shell_quote(partition.get_path()),
output, error, true);
//In many cases the exit status doesn't reflect valid output or an error condition
// so rely on parsing the output to determine success.
//Extract the per device size figure. Guesstimate the per device used
// figure as discussed above. Example output:
//
// Label: none uuid: 36eb51a2-2927-4c92-820f-b2f0b5cdae50
// Total devices 2 FS bytes used 156.00KB
// devid 2 size 2.00GB used 512.00MB path /dev/sdb2
// devid 1 size 2.00GB used 240.75MB path /dev/sdb1
//
// Calculations:
// ptn fs size = devid size
// ptn fs used = total fs used * devid used / sum devid used
Byte_Value ptn_size = partition .get_byte_length() ;
Byte_Value total_fs_used = -1 ; //total fs used
Byte_Value sum_devid_used = 0 ; //sum devid used
Byte_Value devid_used = -1 ; //devid used
Byte_Value devid_size = -1 ; //devid size
//Btrfs file system wide used bytes (extents and items)
Glib::ustring str ;
if ( ! ( str = Utils::regexp_label( output, "FS bytes used ([0-9\\.]+( ?[KMGTPE]?i?B)?)" ) ) .empty() )
total_fs_used = Utils::round( btrfs_size_to_gdouble( str ) ) ;
Glib::ustring::size_type offset = 0 ;
Glib::ustring::size_type index ;
while ( ( index = output .find( "devid ", offset ) ) != Glib::ustring::npos )
{
Glib::ustring devid_path = Utils::regexp_label( output .substr( index ),
"devid .* path (/dev/[[:graph:]]+)" ) ;
if ( ! devid_path .empty() )
{
//Btrfs per devid used bytes (chunks)
Byte_Value used = -1 ;
if ( ! ( str = Utils::regexp_label( output .substr( index ),
"devid .* used ([0-9\\.]+( ?[KMGTPE]?i?B)?) path" ) ) .empty() )
{
used = btrfs_size_to_num( str, ptn_size, false ) ;
sum_devid_used += used ;
if ( devid_path == partition .get_path() )
devid_used = used ;
}
if ( devid_path == partition .get_path() )
{
//Btrfs per device size bytes (chunks)
if ( ! ( str = Utils::regexp_label( output .substr( index ),
"devid .* size ([0-9\\.]+( ?[KMGTPE]?i?B)?) used " ) ) .empty() )
devid_size = btrfs_size_to_num( str, ptn_size, true ) ;
}
}
offset = index + 5 ; //Next find starts immediately after current "devid"
}
if ( total_fs_used > -1 && devid_size > -1 && devid_used > -1 && sum_devid_used > 0 )
{
T = Utils::round( devid_size / double(partition .sector_size) ) ; //ptn fs size
double ptn_fs_used = total_fs_used * ( devid_used / double(sum_devid_used) ) ; //ptn fs used
N = T - Utils::round( ptn_fs_used / double(partition .sector_size) ) ;
partition .set_sector_usage( T, N ) ;
}
else
{
if ( ! output .empty() )
partition.push_back_message( output );
if ( ! error .empty() )
partition.push_back_message( error );
}
}
bool btrfs::write_label( const Partition & partition, OperationDetail & operationdetail )
{
return ! execute_command( "btrfs filesystem label " + Glib::shell_quote( partition.get_path() ) +
" " + Glib::shell_quote( partition.get_filesystem_label() ),
operationdetail, EXEC_CHECK_STATUS );
}
bool btrfs::resize( const Partition & partition_new, OperationDetail & operationdetail, bool fill_partition )
{
bool success = true ;
Glib::ustring path = partition_new .get_path() ;
BTRFS_Device btrfs_dev = get_cache_entry( path ) ;
if ( btrfs_dev .devid == -1 )
{
operationdetail .add_child( OperationDetail(
Glib::ustring::compose( _("Failed to find devid for path %1"), path ), STATUS_ERROR ) ) ;
return false ;
}
Glib::ustring devid_str = Utils::num_to_str( btrfs_dev .devid ) ;
Glib::ustring mount_point ;
if ( ! partition_new .busy )
{
mount_point = mk_temp_dir( "", operationdetail ) ;
if ( mount_point .empty() )
return false ;
success &= ! execute_command( "mount -v -t btrfs " + Glib::shell_quote( path ) +
" " + Glib::shell_quote( mount_point ),
operationdetail, EXEC_CHECK_STATUS );
}
else
mount_point = partition_new .get_mountpoint() ;
if ( success )
{
Glib::ustring size ;
if ( ! fill_partition )
size = Utils::num_to_str( floor( Utils::sector_to_unit(
partition_new .get_sector_length(), partition_new .sector_size, UNIT_KIB ) ) ) + "K" ;
else
size = "max" ;
success &= ! execute_command("btrfs filesystem resize " + devid_str + ":" + size +
" " + Glib::shell_quote(mount_point),
operationdetail, EXEC_CHECK_STATUS);
if ( ! partition_new .busy )
success &= ! execute_command( "umount -v " + Glib::shell_quote( mount_point ),
operationdetail, EXEC_CHECK_STATUS );
}
if ( ! partition_new .busy )
rm_temp_dir( mount_point, operationdetail ) ;
return success ;
}
void btrfs::read_label( Partition & partition )
{
Utils::execute_command("btrfs filesystem show " + Glib::shell_quote(partition.get_path()),
output, error, true);
//In many cases the exit status doesn't reflect valid output or an error condition
// so rely on parsing the output to determine success.
if ( output .compare( 0, 18, "Label: none uuid:" ) == 0 )
{
//Indistinguishable cases of either no label or the label is actually set
// to "none". Assume no label case.
partition.set_filesystem_label( "" );
}
else
{
// Try matching a label enclosed in single quotes, then without quotes, to
// handle reporting of mounted file systems by old btrfs-progs 3.12.
Glib::ustring label = Utils::regexp_label( output, "^Label: '(.*)' uuid:" ) ;
if ( label .empty() )
label = Utils::regexp_label( output, "^Label: (.*) uuid:" ) ;
if ( ! label .empty() )
partition.set_filesystem_label( label );
else
{
if ( ! output .empty() )
partition.push_back_message( output );
if ( ! error .empty() )
partition.push_back_message( error );
}
}
}
void btrfs::read_uuid( Partition & partition )
{
Utils::execute_command("btrfs filesystem show " + Glib::shell_quote(partition.get_path()),
output, error, true);
//In many cases the exit status doesn't reflect valid output or an error condition
// so rely on parsing the output to determine success.
Glib::ustring uuid_str = Utils::regexp_label( output, "uuid:[[:blank:]]*(" RFC4122_NONE_NIL_UUID_REGEXP ")" ) ;
if ( ! uuid_str .empty() )
partition .uuid = uuid_str ;
else
{
if ( ! output .empty() )
partition.push_back_message( output );
if ( ! error .empty() )
partition.push_back_message( error );
}
}
bool btrfs::write_uuid( const Partition & partition, OperationDetail & operationdetail )
{
return ! execute_command( "btrfstune -f -u " + Glib::shell_quote( partition.get_path() ),
operationdetail, EXEC_CHECK_STATUS );
}
void btrfs::clear_cache()
{
btrfs_device_cache .clear() ;
}
//Return the device which is mounting the btrfs in this partition.
// Return empty string if not found (not mounted).
Glib::ustring btrfs::get_mount_device( const Glib::ustring & path )
{
BTRFS_Device btrfs_dev = get_cache_entry( path ) ;
if ( btrfs_dev .devid == -1 || btrfs_dev .members .empty() )
{
//WARNING:
// No btrfs device cache entry found or entry without any member devices.
// Use fallback busy detection method which can only determine if the
// mounting device is mounted or not, not any of the other members of a
// multi-device btrfs file system.
if ( Mount_Info::is_dev_mounted( path ) )
return path ;
return "" ;
}
for ( unsigned int i = 0 ; i < btrfs_dev .members .size() ; i ++ )
if ( Mount_Info::is_dev_mounted( btrfs_dev.members[i] ) )
return btrfs_dev.members[i].m_name;
return "" ;
}
std::vector<Glib::ustring> btrfs::get_members( const Glib::ustring & path )
{
BTRFS_Device btrfs_dev = get_cache_entry( path ) ;
std::vector<Glib::ustring> membs;
for ( unsigned int i = 0 ; i < btrfs_dev.members.size() ; i ++ )
membs.push_back( btrfs_dev.members[i].m_name );
return membs;
}
//Private methods
//Return btrfs device cache entry, incrementally loading cache as required
const BTRFS_Device & btrfs::get_cache_entry( const Glib::ustring & path )
{
std::map<BlockSpecial, BTRFS_Device>::const_iterator bd_iter = btrfs_device_cache.find( BlockSpecial( path ) );
if ( bd_iter != btrfs_device_cache .end() )
return bd_iter ->second ;
Glib::ustring output, error ;
std::vector<int> devid_list ;
std::vector<Glib::ustring> path_list ;
Utils::execute_command("btrfs filesystem show " + Glib::shell_quote(path), output, error, true);
//In many cases the exit status doesn't reflect valid output or an error condition
// so rely on parsing the output to determine success.
//Extract devid and path for each device from output like this:
// Label: none uuid: 36eb51a2-2927-4c92-820f-b2f0b5cdae50
// Total devices 2 FS bytes used 156.00KB
// devid 2 size 2.00GB used 512.00MB path /dev/sdb2
// devid 1 size 2.00GB used 240.75MB path /dev/sdb1
Glib::ustring::size_type offset = 0 ;
Glib::ustring::size_type index ;
while ( ( index = output .find( "devid ", offset ) ) != Glib::ustring::npos )
{
int devid = -1 ;
sscanf( output .substr( index ) .c_str(), "devid %d", &devid ) ;
Glib::ustring devid_path = Utils::regexp_label( output .substr( index ),
"devid .* path (/dev/[[:graph:]]+)" ) ;
if ( devid > -1 && ! devid_path .empty() )
{
devid_list .push_back( devid ) ;
path_list .push_back( devid_path ) ;
}
offset = index + 5 ; //Next find starts immediately after current "devid"
}
//Add cache entries for all found devices
std::vector<BlockSpecial> bs_list;
for ( unsigned int i = 0 ; i < path_list.size() ; i ++ )
bs_list.push_back( BlockSpecial( path_list[i] ) );
for ( unsigned int i = 0 ; i < devid_list .size() ; i ++ )
{
BTRFS_Device btrfs_dev ;
btrfs_dev .devid = devid_list[ i ] ;
btrfs_dev.members = bs_list;
btrfs_device_cache[ BlockSpecial( path_list[i] ) ] = btrfs_dev;
}
bd_iter = btrfs_device_cache.find( BlockSpecial( path ) );
if ( bd_iter != btrfs_device_cache .end() )
return bd_iter ->second ;
//If for any reason we fail to parse the information return an "unknown" record
static BTRFS_Device btrfs_dev = { -1, } ;
return btrfs_dev ;
}
//Return the value of a btrfs tool formatted size, including reversing
// changes in certain cases caused by using binary prefix multipliers
// and rounding to two decimal places of precision. E.g. "2.00GB".
Byte_Value btrfs::btrfs_size_to_num( Glib::ustring str, Byte_Value ptn_bytes, bool scale_up )
{
Byte_Value size_bytes = Utils::round( btrfs_size_to_gdouble( str ) ) ;
gdouble delta = btrfs_size_max_delta( str ) ;
Byte_Value upper_size = size_bytes + ceil( delta ) ;
Byte_Value lower_size = size_bytes - floor( delta ) ;
if ( size_bytes > ptn_bytes && lower_size <= ptn_bytes )
{
//Scale value down to partition size:
// The btrfs tool reported size appears larger than the partition
// size, but the minimum possible size which could have been rounded
// to the reported figure is within the partition size so use the
// smaller partition size instead. Applied to FS device size and FS
// wide used bytes.
// ............| ptn_bytes
// [ x ) size_bytes with upper & lower size
// x scaled down size_bytes
// Do this to avoid the FS size or used bytes being larger than the
// partition size and GParted failing to read the file system usage and
// report a warning.
size_bytes = ptn_bytes ;
}
else if ( scale_up && size_bytes < ptn_bytes && upper_size > ptn_bytes )
{
//Scale value up to partition size:
// The btrfs tool reported size appears smaller than the partition
// size, but the maximum possible size which could have been rounded
// to the reported figure is within the partition size so use the
// larger partition size instead. Applied to FS device size only.
// ............| ptn_bytes
// [ x ) size_bytes with upper & lower size
// x scaled up size_bytes
// Make an assumption that the file system actually fills the
// partition, rather than is slightly smaller to avoid false reporting
// of unallocated space.
size_bytes = ptn_bytes ;
}
return size_bytes ;
}
//Return maximum delta for which num +/- delta would be rounded by btrfs
// tools to str. E.g. btrfs_size_max_delta("2.00GB") -> 5368709.12
gdouble btrfs::btrfs_size_max_delta( Glib::ustring str )
{
Glib::ustring limit_str ;
//Create limit_str. E.g. str = "2.00GB" -> limit_str = "0.005GB"
for ( Glib::ustring::iterator p = str .begin() ; p != str .end() ; p ++ )
{
if ( isdigit( *p ) )
limit_str .append( "0" ) ;
else if ( *p == '.' )
limit_str .append( "." ) ;
else
{
limit_str .append( "5" ) ;
limit_str .append( p, str .end() ) ;
break ;
}
}
gdouble max_delta = btrfs_size_to_gdouble( limit_str ) ;
return max_delta ;
}
//Return the value of a btrfs tool formatted size.
// E.g. btrfs_size_to_gdouble("2.00GB") -> 2147483648.0
gdouble btrfs::btrfs_size_to_gdouble( Glib::ustring str )
{
gchar * suffix ;
gdouble rawN = g_ascii_strtod( str .c_str(), & suffix ) ;
while ( isspace( suffix[0] ) ) //Skip white space before suffix
suffix ++ ;
unsigned long long mult ;
switch ( suffix[0] )
{
case 'K': mult = KIBIBYTE ; break ;
case 'M': mult = MEBIBYTE ; break ;
case 'G': mult = GIBIBYTE ; break ;
case 'T': mult = TEBIBYTE ; break ;
case 'P': mult = PEBIBYTE ; break ;
case 'E': mult = EXBIBYTE ; break ;
default: mult = 1 ; break ;
}
return rawN * mult ;
}
} //GParted
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