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#!/usr/bin/env python
# RaidGuessFS, a FUSE pseudo-filesystem to guess RAID parameters of a damaged device
# Copyright (C) 2015 Ludovic Pouzenc <ludovic@pouzenc.fr>
#
# This file is part of RaidGuessFS.
#
# RaidGuessFS 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 3 of the License, or
# (at your option) any later version.
#
# RaidGuessFS 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 RaidGuessFS. If not, see <http://www.gnu.org/licenses/>
import logging, numpy
class MyRaid():
"""Auxiliary class, managing RAID layer"""
RAID_TYPES = [ '0', '1', '5', '5+0' ]
RAID5_LAYOUTS = [ 'la', 'ra', 'ls', 'rs' ]
def __init__(self, *args, **kwargs):
self.disks = []
self.raid_start = 0
self.raid_end = 0
self.raid_sector_size = 512
self.raid_chunk_size = 65536
self.raid_disk_order = []
self.raid_disk_count = 0
self.raid_layout = 'ls'
def get_raid_start(self):
return self.raid_start
def get_raid_end(self):
return self.raid_end
def get_raid_chunk_size(self):
return self.raid_chunk_size
def get_raid_disk_order(self):
return self.raid_disk_order
def get_raid_disk_order_str(self):
return ' '.join(map(str,self.raid_disk_order))
def get_raid_layout(self):
return self.raid_layout
def set_disks(self, disks):
self.disks = disks
def set_raid_start(self, new_raid_start):
"""Update the start offset of raid data on underlying disks"""
self.raid_start = new_raid_start
def set_raid_end(self, new_raid_end):
"""Update the end offset of raid data on underlying disks"""
self.raid_end = new_raid_end
def set_raid_chunk_size(self, new_raid_chunk_size):
"""Update the size of chucks of data (or slice size)"""
self.raid_chunk_size = new_raid_chunk_size
def set_raid_disk_order(self, new_raid_disk_order):
"""Update the raid logical disk order"""
card=len(self.disks)
check=[0]*card
for item in new_raid_disk_order:
d = int(item)
if not 0 <= d < card:
raise ValueError('Value out of range : %i [0,%i]'%(d,card-1))
check[d]=check[d]+1
for d in range(card):
if check[d] != 1 and check[d] != 0:
raise ValueError('Disk %i appears %i times (must be 0 or 1)'%(d,check[d]))
self.raid_disk_order = new_raid_disk_order
self.raid_disk_count = len(new_raid_disk_order)
def set_raid_layout(self, new_raid_layout):
if new_raid_layout in MyRaid.RAID5_LAYOUTS:
self.raid_layout = new_raid_layout
else:
raise ValueError('raid_layout has to be one of %s'%' '.join(RAID_LAYOUTS))
def sizeof_raid_result(self, raid_type):
size = self.raid_end - self.raid_start
if size <= 0 :
return 0
else:
return {
'0' : size * self.raid_disk_count,
'1' : size if self.raid_disk_count == 2 else 0,
'5' : size * (self.raid_disk_count - 1) if self.raid_disk_count >= 3 else 0,
'5+0': size * (self.raid_disk_count - 2) if self.raid_disk_count >= 6 and self.raid_disk_count % 2 == 0 else 0,
}[raid_type]
def sizeof_disk_xor(self, raid_type):
size = self.raid_end - self.raid_start
if size <= 0:
return 0
else:
return {
'0' : 0, # TODO Could contain some plain text error message
'1' : size if self.raid_disk_count == 2 else 0,
'5' : size if self.raid_disk_count >= 3 else 0,
'5+0': size if self.raid_disk_count >= 6 and self.raid_disk_count % 2 == 0 else 0,
}[raid_type]
def sizeof_disk_parity(self, raid_type):
return self.sizeof_disk_xor(raid_type) / self.raid_sector_size * 16
def xor_blocks(self,fd_list, offset, size):
"""Compute bitwise XOR against a bunch of disks slice"""
logging.info("Enter xor_blocks(fd_list,%d,%d)"%(offset, size))
if size % 8 != 0:
raise ValueError('xor_blocks : size must be multiple of 8')
dt = numpy.dtype('<Q8')
fd_list[0].seek(offset)
str_b1=fd_list[0].read(size)
numpy_b1 = numpy.fromstring(str_b1, dtype=dt)
all_zero = (numpy.count_nonzero(numpy_b1) == 0 )
any_zero = all_zero
for fd in fd_list[1:]:
fd.seek(offset)
str_b2=fd.read(size)
numpy_b2 = numpy.fromstring(str_b2, dtype=dt)
b2_zero = (numpy.count_nonzero(numpy_b2) == 0 )
if all_zero == True:
all_zero = b2_zero
if any_zero == False:
any_zero = b2_zero
numpy.bitwise_xor(numpy_b1,numpy_b2,numpy_b1)
if all_zero == True:
result = 'z'
elif numpy.count_nonzero(numpy_b1) == 0:
if any_zero:
result = 'g'
else:
result = 'G'
else:
result = 'b'
logging.info("Exit. xor_blocks(fd_list,%d,%d)"%(offset, size))
#import binascii
#logging.warn(binascii.hexlify(numpy_b1))
return (result,numpy_b1)
def read_disk_xor(self,raid_type,offset,size):
raid_disks = [ self.disks[i] for i in self.raid_disk_order ]
return self.xor_blocks(raid_disks,offset,size)[1].tostring()
def read_disk_parity(self,raid_type,offset,size):
"""Returns textual information about parity status of each sector"""
logging.warn("Enter read_disk_parity(%s,%d,%d)"%(raid_type,offset,size))
raid_disks = [ self.disks[i] for i in self.raid_disk_order ]
start = self.raid_start + offset * self.raid_sector_size / 16
end = start + size * self.raid_sector_size / 16
#TODO : improove for nested levels
if raid_type in ['1','5', '5+0']:
result = ''.join(
[ '0x%011x %c\n'%( addr, self.xor_blocks(raid_disks, addr, self.raid_sector_size)[0])
for addr in range(start, end, self.raid_sector_size)
])
else:
result = None
logging.warn("Exit. read_disk_parity(%s,%d,%d)"%(raid_type,offset,size))
return result
def read_raid_result(self,raid_type,offset,size):
"""Returns actual RAID data"""
raid_disks = [ self.disks[i] for i in self.raid_disk_order ] # TODO A garder en attribut ?
disk_count = len(self.raid_disk_order) # TODO doublon ?
if raid_type == '0':
segment_no = offset / self.raid_chunk_size
segment_off = offset % self.raid_chunk_size
stripe_no = segment_no / disk_count
par_disk = -1
data_disk = segment_no % disk_count
off_disk = self.raid_start + stripe_no * self.raid_chunk_size + segment_off
size2 = min(size, (segment_no+1) * self.raid_chunk_size - offset)
elif raid_type == '1':
segment_no = -1
segment_off = -1
stripe_no = -1
par_disk = 1
data_disk = 0
off_disk = self.raid_start + offset
size2 = size
elif raid_type == '5':
segment_no = offset / self.raid_chunk_size
segment_off = offset % self.raid_chunk_size
stripe_no = segment_no / (disk_count-1)
if self.raid_layout in ['ls','la']:
par_disk = (disk_count-1) - (stripe_no % disk_count)
else: # self.raid_layout in ['rs','ra']:
par_disk = stripe_no % disk_count
if self.raid_layout in ['ls','rs']:
data_disk = (par_disk+1 + (segment_no % (disk_count-1)) ) % disk_count
else: # self.raid_layout in ['la','ra']:
data_disk = segment_no % (disk_count-1)
if data_disk >= par_disk:
data_disk = data_disk + 1
off_disk = self.raid_start + stripe_no * self.raid_chunk_size + segment_off
size2 = min(size, (segment_no+1) * self.raid_chunk_size - offset)
logging.info("raid.read_result(%s): offset=%d,segment_no=%d,segment_off=%d,stripe_no=%d,par_disk=%d,data_disk=%d,off_disk=%d,size2=%d,segment_off+size2=%d"
% (raid_type,offset,segment_no,segment_off,stripe_no,par_disk,data_disk,off_disk,size2,segment_off+size2) )
#TODO recorver from parity if damaged sectors in data_disk
data_fd = raid_disks[data_disk]
data_fd.seek(off_disk)
data = data_fd.read(size2)
# This kills performance but don't make short reads before EOF
#if size2 > 0 and size2 < size:
# data += self.read_result(self,raid_type,offset+size2,size-size2)
return data
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