Christopher Haster
5fa85583cd
Unfortunately block-level erased-state checksums (becksums) don't really
work as intended.
An invalid becksum _does_ signal that a prog has been attempted, but a
valid becksum does _not_ prove that a prog has _not_ been attempted.
Rbyd ecksums work, but only thanks to a combination of prioritizing
valid commits and the use of perturb bits to force erased-state changes.
It _is_ possible to end up with an ecksum collision, but only if you
1. lose power before completing a commit, and 2. end up with a
non-trivial crc32c collision. If this does happen, at the very least the
resulting commit will likely end up corrupted and thrown away later.
Block-level becksums, at least as originally designed, don't have either
of these protections. To make matters worse, the blocks these becksums
reference contain only raw user data. Write 0xffs into a file and you
will likely end up with a becksum collision!
This is a problem for a couple of reasons:
1. Progging multiple times to erased-state is likely to result in
corrupted data, though this is also likely to get caught with
validating writes.
Worst case, the resulting data looks valid, but with weakened data
retention.
2. Because becksums are stored in the copy-on-write metadata of the
file, attempting to open a file twice for writing (or more advanced
copy-on-write operations in the future) can lead to a situation where
a prog is attempted on _already committed_ data.
This is very bad and breaks copy-on-write guarantees.
---
So clearly becksums are not fit for purpose and should be dropped. What
can we replace them with?
The first option, implemented here, is RAM-tracked erased state. Give
each lfsr_file_t its own eblock/eoff fields to track the last known good
erased-state. And before each prog, clear eblock/eoff so we never
accidentally prog to the same erased-state twice.
It's interesting to note we don't currently clear eblock/eoff in all
file handles, this is ok only because we don't currently share
eblock/eoff across file handles. Each eblock/eoff is exclusive to the
lfsr_file_t and does not appear anywhere else in the system.
The main downside of this approach is that, well, the RAM-tracked
erase-state is only tracked in RAM. Block-level erased-state effectively
does not persist across reboots. I've considered adding some sort of
per-file erased-state tracking to the mdir that would need to be cleared
before use, but such a mechanism ends up quite complicated.
At the moment, I think the best second option is to put erased-state
tracking in the future-planned bmap. This would let you opt-in to
on-disk tracking of all erased-state in the system.
One nice thing about RAM-tracked erased-state is that it's not on disk,
so it's not really a compatibility concern and won't get in the way of
additional future erased-state tracking.
---
Benchmarking becksums vs RAM-tracking has been quite interesting. While
in theory becksums can track much more erased-state, it's quite unlikely
anything but the most recent erased-state actually ends up used. The end
result is no real measurable performance loss, and actually a minor
speedup because we don't need to calculate becksums on every block
write.
There are some pathological cases, such as multiple write heads, but
these are out-of-scope right now (note! multiple explicit file handles
currently handle this case beautifully because we don't share
eblock/eoff!)
Becksums were also relatively complicated, and needed extra scaffolding
to pass around/propagate as secondary tags alongside the primary bptr.
So trading these for RAM-tracking also gives us a nice bit of code/stack
savings, albeit at a 2-word RAM cost in lfsr_file_t:
code stack structs
before: 33888 2864 1096
after: 33564 (-1.0%) 2816 (-1.7%) 1104 (+0.7%)
lfsr_file_t before: 104
lfsr_file_t after: 112 (+7.7%)
1076 lines
37 KiB
Python
Executable File
1076 lines
37 KiB
Python
Executable File
#!/usr/bin/env python3
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import bisect
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import collections as co
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import itertools as it
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import math as m
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import os
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import struct
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TAG_NULL = 0x0000
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TAG_CONFIG = 0x0000
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TAG_MAGIC = 0x0003
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TAG_VERSION = 0x0004
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TAG_RCOMPAT = 0x0005
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TAG_WCOMPAT = 0x0006
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TAG_OCOMPAT = 0x0007
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TAG_GEOMETRY = 0x0009
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TAG_NAMELIMIT = 0x000c
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TAG_SIZELIMIT = 0x000d
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TAG_GDELTA = 0x0100
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TAG_GRMDELTA = 0x0100
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TAG_NAME = 0x0200
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TAG_REG = 0x0201
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TAG_DIR = 0x0202
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TAG_ORPHAN = 0x0203
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TAG_BOOKMARK = 0x0204
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TAG_STRUCT = 0x0300
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TAG_DATA = 0x0300
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TAG_BLOCK = 0x0304
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TAG_BSHRUB = 0x0308
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TAG_BTREE = 0x030c
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TAG_DID = 0x0310
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TAG_BRANCH = 0x031c
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TAG_MROOT = 0x0321
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TAG_MDIR = 0x0325
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TAG_MTREE = 0x032c
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TAG_UATTR = 0x0400
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TAG_SATTR = 0x0600
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TAG_SHRUB = 0x1000
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TAG_CKSUM = 0x3000
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TAG_ECKSUM = 0x3100
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TAG_ALT = 0x4000
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TAG_R = 0x2000
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TAG_GT = 0x1000
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# some ways of block geometry representations
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# 512 -> 512
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# 512x16 -> (512, 16)
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# 0x200x10 -> (512, 16)
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def bdgeom(s):
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s = s.strip()
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b = 10
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if s.startswith('0x') or s.startswith('0X'):
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s = s[2:]
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b = 16
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elif s.startswith('0o') or s.startswith('0O'):
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s = s[2:]
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b = 8
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elif s.startswith('0b') or s.startswith('0B'):
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s = s[2:]
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b = 2
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if 'x' in s:
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s, s_ = s.split('x', 1)
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return (int(s, b), int(s_, b))
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else:
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return int(s, b)
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# parse some rbyd addr encodings
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# 0xa -> [0xa]
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# 0xa.c -> [(0xa, 0xc)]
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# 0x{a,b} -> [0xa, 0xb]
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# 0x{a,b}.c -> [(0xa, 0xc), (0xb, 0xc)]
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def rbydaddr(s):
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s = s.strip()
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b = 10
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if s.startswith('0x') or s.startswith('0X'):
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s = s[2:]
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b = 16
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elif s.startswith('0o') or s.startswith('0O'):
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s = s[2:]
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b = 8
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elif s.startswith('0b') or s.startswith('0B'):
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s = s[2:]
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b = 2
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trunk = None
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if '.' in s:
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s, s_ = s.split('.', 1)
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trunk = int(s_, b)
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if s.startswith('{') and '}' in s:
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ss = s[1:s.find('}')].split(',')
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else:
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ss = [s]
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addr = []
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for s in ss:
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if trunk is not None:
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addr.append((int(s, b), trunk))
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else:
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addr.append(int(s, b))
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return addr
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def crc32c(data, crc=0):
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crc ^= 0xffffffff
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for b in data:
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crc ^= b
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for j in range(8):
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crc = (crc >> 1) ^ ((crc & 1) * 0x82f63b78)
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return 0xffffffff ^ crc
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def popc(x):
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return bin(x).count('1')
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def fromle32(data):
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return struct.unpack('<I', data[0:4].ljust(4, b'\0'))[0]
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def fromleb128(data):
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word = 0
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for i, b in enumerate(data):
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word |= ((b & 0x7f) << 7*i)
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word &= 0xffffffff
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if not b & 0x80:
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return word, i+1
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return word, len(data)
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def fromtag(data):
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data = data.ljust(4, b'\0')
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tag = (data[0] << 8) | data[1]
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weight, d = fromleb128(data[2:])
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size, d_ = fromleb128(data[2+d:])
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return tag>>15, tag&0x7fff, weight, size, 2+d+d_
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def frombranch(data):
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d = 0
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block, d_ = fromleb128(data[d:]); d += d_
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trunk, d_ = fromleb128(data[d:]); d += d_
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cksum = fromle32(data[d:]); d += 4
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return block, trunk, cksum
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def xxd(data, width=16):
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for i in range(0, len(data), width):
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yield '%-*s %-*s' % (
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3*width,
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' '.join('%02x' % b for b in data[i:i+width]),
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width,
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''.join(
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b if b >= ' ' and b <= '~' else '.'
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for b in map(chr, data[i:i+width])))
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def tagrepr(tag, w=None, size=None, off=None):
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if (tag & 0x6fff) == TAG_NULL:
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return '%snull%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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' w%d' % w if w else '',
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' %d' % size if size else '')
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elif (tag & 0x6f00) == TAG_CONFIG:
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return '%s%s%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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'magic' if (tag & 0xfff) == TAG_MAGIC
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else 'version' if (tag & 0xfff) == TAG_VERSION
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else 'rcompat' if (tag & 0xfff) == TAG_RCOMPAT
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else 'wcompat' if (tag & 0xfff) == TAG_WCOMPAT
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else 'ocompat' if (tag & 0xfff) == TAG_OCOMPAT
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else 'geometry' if (tag & 0xfff) == TAG_GEOMETRY
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else 'sizelimit' if (tag & 0xfff) == TAG_SIZELIMIT
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else 'namelimit' if (tag & 0xfff) == TAG_NAMELIMIT
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else 'config 0x%02x' % (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6f00) == TAG_GDELTA:
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return '%s%s%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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'grmdelta' if (tag & 0xfff) == TAG_GRMDELTA
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else 'gdelta 0x%02x' % (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6f00) == TAG_NAME:
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return '%s%s%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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'name' if (tag & 0xfff) == TAG_NAME
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else 'reg' if (tag & 0xfff) == TAG_REG
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else 'dir' if (tag & 0xfff) == TAG_DIR
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else 'orphan' if (tag & 0xfff) == TAG_ORPHAN
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else 'bookmark' if (tag & 0xfff) == TAG_BOOKMARK
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else 'name 0x%02x' % (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6f00) == TAG_STRUCT:
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return '%s%s%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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'data' if (tag & 0xfff) == TAG_DATA
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else 'block' if (tag & 0xfff) == TAG_BLOCK
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else 'bshrub' if (tag & 0xfff) == TAG_BSHRUB
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else 'btree' if (tag & 0xfff) == TAG_BTREE
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else 'did' if (tag & 0xfff) == TAG_DID
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else 'branch' if (tag & 0xfff) == TAG_BRANCH
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else 'mroot' if (tag & 0xfff) == TAG_MROOT
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else 'mdir' if (tag & 0xfff) == TAG_MDIR
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else 'mtree' if (tag & 0xfff) == TAG_MTREE
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else 'struct 0x%02x' % (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6e00) == TAG_UATTR:
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return '%suattr 0x%02x%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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((tag & 0x100) >> 1) | (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x6e00) == TAG_SATTR:
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return '%ssattr 0x%02x%s%s' % (
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'shrub' if tag & TAG_SHRUB else '',
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((tag & 0x100) >> 1) | (tag & 0xff),
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x7f00) == TAG_CKSUM:
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return 'cksum 0x%02x%s%s' % (
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tag & 0xff,
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif (tag & 0x7f00) == TAG_ECKSUM:
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return 'ecksum%s%s%s' % (
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' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
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' w%d' % w if w else '',
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' %s' % size if size is not None else '')
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elif tag & TAG_ALT:
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return 'alt%s%s%s%s%s' % (
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'r' if tag & TAG_R else 'b',
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'a' if tag & 0x0fff == 0 and tag & TAG_GT
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else 'n' if tag & 0x0fff == 0
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else 'gt' if tag & TAG_GT
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else 'le',
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' 0x%x' % (tag & 0x0fff) if tag & 0x0fff != 0 else '',
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' w%d' % w if w is not None else '',
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' 0x%x' % (0xffffffff & (off-size))
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if size and off is not None
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else ' -%d' % size if size
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else '')
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else:
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return '0x%04x%s%s' % (
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tag,
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' w%d' % w if w is not None else '',
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' %d' % size if size is not None else '')
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# this type is used for tree representations
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TBranch = co.namedtuple('TBranch', 'a, b, d, c')
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# our core rbyd type
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class Rbyd:
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def __init__(self, block, data, rev, eoff, trunk, weight):
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self.block = block
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self.data = data
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self.rev = rev
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self.eoff = eoff
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self.trunk = trunk
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self.weight = weight
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self.redund_blocks = []
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def addr(self):
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if not self.redund_blocks:
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return '0x%x.%x' % (self.block, self.trunk)
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else:
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return '0x{%x,%s}.%x' % (
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self.block,
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','.join('%x' % block for block in self.redund_blocks),
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self.trunk)
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@classmethod
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def fetch(cls, f, block_size, blocks, trunk=None):
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if isinstance(blocks, int):
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blocks = [blocks]
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if len(blocks) > 1:
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# fetch all blocks
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rbyds = [cls.fetch(f, block_size, block, trunk) for block in blocks]
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# determine most recent revision
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i = 0
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for i_, rbyd in enumerate(rbyds):
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# compare with sequence arithmetic
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if rbyd and (
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not rbyds[i]
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or not ((rbyd.rev - rbyds[i].rev) & 0x80000000)
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or (rbyd.rev == rbyds[i].rev
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and rbyd.trunk > rbyds[i].trunk)):
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i = i_
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# keep track of the other blocks
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rbyd = rbyds[i]
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rbyd.redund_blocks = [rbyds[(i+1+j) % len(rbyds)].block
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for j in range(len(rbyds)-1)]
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return rbyd
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else:
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# block may encode a trunk
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block = blocks[0]
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if isinstance(block, tuple):
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if trunk is None:
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trunk = block[1]
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block = block[0]
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# seek to the block
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f.seek(block * block_size)
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data = f.read(block_size)
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# fetch the rbyd
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rev = fromle32(data[0:4])
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cksum = 0
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cksum_ = crc32c(data[0:4])
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eoff = 0
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j_ = 4
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trunk_ = 0
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trunk__ = 0
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trunk___ = 0
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weight = 0
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weight_ = 0
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weight__ = 0
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wastrunk = False
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trunkeoff = None
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while j_ < len(data) and (not trunk or eoff <= trunk):
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v, tag, w, size, d = fromtag(data[j_:])
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if v != (popc(cksum_) & 1):
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break
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cksum_ = crc32c(data[j_:j_+d], cksum_)
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j_ += d
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if not tag & TAG_ALT and j_ + size > len(data):
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break
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# take care of cksums
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if not tag & TAG_ALT:
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if (tag & 0xff00) != TAG_CKSUM:
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cksum_ = crc32c(data[j_:j_+size], cksum_)
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# found a cksum?
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else:
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cksum__ = fromle32(data[j_:j_+4])
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if cksum_ != cksum__:
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break
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# commit what we have
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eoff = trunkeoff if trunkeoff else j_ + size
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cksum = cksum_
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trunk_ = trunk__
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weight = weight_
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# evaluate trunks
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if (tag & 0xf000) != TAG_CKSUM and (
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not trunk or trunk >= j_-d or wastrunk):
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# new trunk?
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if not wastrunk:
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wastrunk = True
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trunk___ = j_-d
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weight__ = 0
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# keep track of weight
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weight__ += w
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# end of trunk?
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if not tag & TAG_ALT:
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wastrunk = False
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# update trunk/weight unless we found a shrub or an
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# explicit trunk (which may be a shrub) is requested
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if not tag & TAG_SHRUB or trunk:
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trunk__ = trunk___
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weight_ = weight__
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# keep track of eoff for best matching trunk
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if trunk and j_ + size > trunk:
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trunkeoff = j_ + size
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eoff = trunkeoff
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cksum = cksum_
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trunk_ = trunk__
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weight = weight_
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if not tag & TAG_ALT:
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j_ += size
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return cls(block, data, rev, eoff, trunk_, weight)
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def lookup(self, rid, tag):
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if not self:
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return True, 0, -1, 0, 0, 0, b'', []
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tag = max(tag, 0x1)
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lower = 0
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upper = self.weight
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path = []
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# descend down tree
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j = self.trunk
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while True:
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_, alt, weight_, jump, d = fromtag(self.data[j:])
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# found an alt?
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if alt & TAG_ALT:
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# follow?
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if ((rid, tag & 0xfff) > (upper-weight_-1, alt & 0xfff)
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if alt & TAG_GT
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else ((rid, tag & 0xfff)
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<= (lower+weight_-1, alt & 0xfff))):
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lower += upper-lower-weight_ if alt & TAG_GT else 0
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upper -= upper-lower-weight_ if not alt & TAG_GT else 0
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j = j - jump
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# figure out which color
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if alt & TAG_R:
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_, nalt, _, _, _ = fromtag(self.data[j+jump+d:])
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if nalt & TAG_R:
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path.append((j+jump, j, True, 'y'))
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else:
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path.append((j+jump, j, True, 'r'))
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else:
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path.append((j+jump, j, True, 'b'))
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# stay on path
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else:
|
|
lower += weight_ if not alt & TAG_GT else 0
|
|
upper -= weight_ if alt & TAG_GT else 0
|
|
j = j + d
|
|
|
|
# figure out which color
|
|
if alt & TAG_R:
|
|
_, nalt, _, _, _ = fromtag(self.data[j:])
|
|
if nalt & TAG_R:
|
|
path.append((j-d, j, False, 'y'))
|
|
else:
|
|
path.append((j-d, j, False, 'r'))
|
|
else:
|
|
path.append((j-d, j, False, 'b'))
|
|
|
|
# found tag
|
|
else:
|
|
rid_ = upper-1
|
|
tag_ = alt
|
|
w_ = upper-lower
|
|
|
|
done = not tag_ or (rid_, tag_) < (rid, tag)
|
|
|
|
return done, rid_, tag_, w_, j, d, self.data[j+d:j+d+jump], path
|
|
|
|
def __bool__(self):
|
|
return bool(self.trunk)
|
|
|
|
def __eq__(self, other):
|
|
return self.block == other.block and self.trunk == other.trunk
|
|
|
|
def __ne__(self, other):
|
|
return not self.__eq__(other)
|
|
|
|
def __iter__(self):
|
|
tag = 0
|
|
rid = -1
|
|
|
|
while True:
|
|
done, rid, tag, w, j, d, data, _ = self.lookup(rid, tag+0x1)
|
|
if done:
|
|
break
|
|
|
|
yield rid, tag, w, j, d, data
|
|
|
|
# create tree representation for debugging
|
|
def tree(self, *,
|
|
rbyd=False):
|
|
trunks = co.defaultdict(lambda: (-1, 0))
|
|
alts = co.defaultdict(lambda: {})
|
|
|
|
rid, tag = -1, 0
|
|
while True:
|
|
done, rid, tag, w, j, d, data, path = self.lookup(rid, tag+0x1)
|
|
# found end of tree?
|
|
if done:
|
|
break
|
|
|
|
# keep track of trunks/alts
|
|
trunks[j] = (rid, tag)
|
|
|
|
for j_, j__, followed, c in path:
|
|
if followed:
|
|
alts[j_] |= {'f': j__, 'c': c}
|
|
else:
|
|
alts[j_] |= {'nf': j__, 'c': c}
|
|
|
|
if rbyd:
|
|
# treat unreachable alts as converging paths
|
|
for j_, alt in alts.items():
|
|
if 'f' not in alt:
|
|
alt['f'] = alt['nf']
|
|
elif 'nf' not in alt:
|
|
alt['nf'] = alt['f']
|
|
|
|
else:
|
|
# prune any alts with unreachable edges
|
|
pruned = {}
|
|
for j_, alt in alts.items():
|
|
if 'f' not in alt:
|
|
pruned[j_] = alt['nf']
|
|
elif 'nf' not in alt:
|
|
pruned[j_] = alt['f']
|
|
for j_ in pruned.keys():
|
|
del alts[j_]
|
|
|
|
for j_, alt in alts.items():
|
|
while alt['f'] in pruned:
|
|
alt['f'] = pruned[alt['f']]
|
|
while alt['nf'] in pruned:
|
|
alt['nf'] = pruned[alt['nf']]
|
|
|
|
# find the trunk and depth of each alt
|
|
def rec_trunk(j_):
|
|
if j_ not in alts:
|
|
return trunks[j_]
|
|
else:
|
|
if 'nft' not in alts[j_]:
|
|
alts[j_]['nft'] = rec_trunk(alts[j_]['nf'])
|
|
return alts[j_]['nft']
|
|
|
|
for j_ in alts.keys():
|
|
rec_trunk(j_)
|
|
for j_, alt in alts.items():
|
|
if alt['f'] in alts:
|
|
alt['ft'] = alts[alt['f']]['nft']
|
|
else:
|
|
alt['ft'] = trunks[alt['f']]
|
|
|
|
def rec_height(j_):
|
|
if j_ not in alts:
|
|
return 0
|
|
else:
|
|
if 'h' not in alts[j_]:
|
|
alts[j_]['h'] = max(
|
|
rec_height(alts[j_]['f']),
|
|
rec_height(alts[j_]['nf'])) + 1
|
|
return alts[j_]['h']
|
|
|
|
for j_ in alts.keys():
|
|
rec_height(j_)
|
|
|
|
t_depth = max((alt['h']+1 for alt in alts.values()), default=0)
|
|
|
|
# convert to more general tree representation
|
|
tree = set()
|
|
for j, alt in alts.items():
|
|
# note all non-trunk edges should be black
|
|
tree.add(TBranch(
|
|
a=alt['nft'],
|
|
b=alt['nft'],
|
|
d=t_depth-1 - alt['h'],
|
|
c=alt['c'],
|
|
))
|
|
if alt['ft'] != alt['nft']:
|
|
tree.add(TBranch(
|
|
a=alt['nft'],
|
|
b=alt['ft'],
|
|
d=t_depth-1 - alt['h'],
|
|
c='b',
|
|
))
|
|
|
|
return tree, t_depth
|
|
|
|
|
|
def main(disk, roots=None, *,
|
|
block_size=None,
|
|
block_count=None,
|
|
trunk=None,
|
|
color='auto',
|
|
**args):
|
|
# figure out what color should be
|
|
if color == 'auto':
|
|
color = sys.stdout.isatty()
|
|
elif color == 'always':
|
|
color = True
|
|
else:
|
|
color = False
|
|
|
|
# is bd geometry specified?
|
|
if isinstance(block_size, tuple):
|
|
block_size, block_count_ = block_size
|
|
if block_count is None:
|
|
block_count = block_count_
|
|
|
|
# flatten roots, default to block 0
|
|
if not roots:
|
|
roots = [[0]]
|
|
roots = [block for roots_ in roots for block in roots_]
|
|
|
|
# we seek around a bunch, so just keep the disk open
|
|
with open(disk, 'rb') as f:
|
|
# if block_size is omitted, assume the block device is one big block
|
|
if block_size is None:
|
|
f.seek(0, os.SEEK_END)
|
|
block_size = f.tell()
|
|
|
|
# fetch the root
|
|
btree = Rbyd.fetch(f, block_size, roots, trunk)
|
|
print('btree %s, rev %d, weight %d' % (
|
|
btree.addr(), btree.rev, btree.weight))
|
|
|
|
# look up a bid, while keeping track of the search path
|
|
def btree_lookup(bid, *,
|
|
depth=None):
|
|
rbyd = btree
|
|
rid = bid
|
|
depth_ = 1
|
|
path = []
|
|
|
|
# corrupted? return a corrupted block once
|
|
if not rbyd:
|
|
return bid > 0, bid, 0, rbyd, -1, [], path
|
|
|
|
while True:
|
|
# collect all tags, normally you don't need to do this
|
|
# but we are debugging here
|
|
name = None
|
|
tags = []
|
|
branch = None
|
|
rid_ = rid
|
|
tag = 0
|
|
w = 0
|
|
for i in it.count():
|
|
done, rid__, tag, w_, j, d, data, _ = rbyd.lookup(
|
|
rid_, tag+0x1)
|
|
if done or (i != 0 and rid__ != rid_):
|
|
break
|
|
|
|
# first tag indicates the branch's weight
|
|
if i == 0:
|
|
rid_, w = rid__, w_
|
|
|
|
# catch any branches
|
|
if tag & 0xfff == TAG_BRANCH:
|
|
branch = (tag, j, d, data)
|
|
|
|
tags.append((tag, j, d, data))
|
|
|
|
# keep track of path
|
|
path.append((bid + (rid_-rid), w, rbyd, rid_, tags))
|
|
|
|
# descend down branch?
|
|
if branch is not None and (
|
|
not depth or depth_ < depth):
|
|
tag, j, d, data = branch
|
|
block, trunk, cksum = frombranch(data)
|
|
rbyd = Rbyd.fetch(f, block_size, block, trunk)
|
|
|
|
# corrupted? bail here so we can keep traversing the tree
|
|
if not rbyd:
|
|
return False, bid + (rid_-rid), w, rbyd, -1, [], path
|
|
|
|
rid -= (rid_-(w-1))
|
|
depth_ += 1
|
|
else:
|
|
return not tags, bid + (rid_-rid), w, rbyd, rid_, tags, path
|
|
|
|
# precompute rbyd-trees if requested
|
|
t_width = 0
|
|
if args.get('tree') or args.get('rbyd'):
|
|
# find the max depth of each layer to nicely align trees
|
|
bdepths = {}
|
|
bid = -1
|
|
while True:
|
|
done, bid, w, rbyd, rid, tags, path = btree_lookup(
|
|
bid+1, depth=args.get('depth'))
|
|
if done:
|
|
break
|
|
|
|
for d, (bid, w, rbyd, rid, tags) in enumerate(path):
|
|
_, rdepth = rbyd.tree(rbyd=args.get('rbyd'))
|
|
bdepths[d] = max(bdepths.get(d, 0), rdepth)
|
|
|
|
# find all branches
|
|
tree = set()
|
|
root = None
|
|
branches = {}
|
|
bid = -1
|
|
while True:
|
|
done, bid, w, rbyd, rid, tags, path = btree_lookup(
|
|
bid+1, depth=args.get('depth'))
|
|
if done:
|
|
break
|
|
|
|
d_ = 0
|
|
leaf = None
|
|
for d, (bid, w, rbyd, rid, tags) in enumerate(path):
|
|
if not tags:
|
|
continue
|
|
|
|
# map rbyd tree into B-tree space
|
|
rtree, rdepth = rbyd.tree(rbyd=args.get('rbyd'))
|
|
|
|
# note we adjust our bid/rids to be left-leaning,
|
|
# this allows a global order and make tree rendering quite
|
|
# a bit easier
|
|
rtree_ = set()
|
|
for branch in rtree:
|
|
a_rid, a_tag = branch.a
|
|
b_rid, b_tag = branch.b
|
|
_, _, _, a_w, _, _, _, _ = rbyd.lookup(a_rid, 0)
|
|
_, _, _, b_w, _, _, _, _ = rbyd.lookup(b_rid, 0)
|
|
rtree_.add(TBranch(
|
|
a=(a_rid-(a_w-1), a_tag),
|
|
b=(b_rid-(b_w-1), b_tag),
|
|
d=branch.d,
|
|
c=branch.c,
|
|
))
|
|
rtree = rtree_
|
|
|
|
# connect our branch to the rbyd's root
|
|
if leaf is not None:
|
|
root = min(rtree,
|
|
key=lambda branch: branch.d,
|
|
default=None)
|
|
|
|
if root is not None:
|
|
r_rid, r_tag = root.a
|
|
else:
|
|
r_rid, r_tag = rid-(w-1), tags[0][0]
|
|
tree.add(TBranch(
|
|
a=leaf,
|
|
b=(bid-rid+r_rid, d, r_rid, r_tag),
|
|
d=d_-1,
|
|
c='b',
|
|
))
|
|
|
|
for branch in rtree:
|
|
# map rbyd branches into our btree space
|
|
a_rid, a_tag = branch.a
|
|
b_rid, b_tag = branch.b
|
|
tree.add(TBranch(
|
|
a=(bid-rid+a_rid, d, a_rid, a_tag),
|
|
b=(bid-rid+b_rid, d, b_rid, b_tag),
|
|
d=branch.d + d_ + bdepths.get(d, 0)-rdepth,
|
|
c=branch.c,
|
|
))
|
|
|
|
d_ += max(bdepths.get(d, 0), 1)
|
|
leaf = (bid-(w-1), d, rid-(w-1),
|
|
next((tag for tag, _, _, _ in tags
|
|
if tag & 0xfff == TAG_BRANCH),
|
|
TAG_BRANCH))
|
|
|
|
# remap branches to leaves if we aren't showing inner branches
|
|
if not args.get('inner'):
|
|
# step through each layer backwards
|
|
b_depth = max((branch.b[1]+1 for branch in tree), default=0)
|
|
|
|
# keep track of the original bids, unfortunately because we
|
|
# store the bids in the branches we overwrite these
|
|
tree = {(branch.b[0] - branch.b[2], branch) for branch in tree}
|
|
|
|
for bd in reversed(range(b_depth-1)):
|
|
# find leaf-roots at this level
|
|
roots = {}
|
|
for bid, branch in tree:
|
|
# choose the highest node as the root
|
|
if (branch.b[1] == b_depth-1
|
|
and (bid not in roots
|
|
or branch.d < roots[bid].d)):
|
|
roots[bid] = branch
|
|
|
|
# remap branches to leaf-roots
|
|
tree_ = set()
|
|
for bid, branch in tree:
|
|
if branch.a[1] == bd and branch.a[0] in roots:
|
|
branch = TBranch(
|
|
a=roots[branch.a[0]].b,
|
|
b=branch.b,
|
|
d=branch.d,
|
|
c=branch.c,
|
|
)
|
|
if branch.b[1] == bd and branch.b[0] in roots:
|
|
branch = TBranch(
|
|
a=branch.a,
|
|
b=roots[branch.b[0]].b,
|
|
d=branch.d,
|
|
c=branch.c,
|
|
)
|
|
tree_.add((bid, branch))
|
|
tree = tree_
|
|
|
|
# strip out bids
|
|
tree = {branch for _, branch in tree}
|
|
|
|
# precompute B-trees if requested
|
|
elif args.get('btree'):
|
|
# find all branches
|
|
tree = set()
|
|
root = None
|
|
branches = {}
|
|
bid = -1
|
|
while True:
|
|
done, bid, w, rbyd, rid, tags, path = btree_lookup(
|
|
bid+1, depth=args.get('depth'))
|
|
if done:
|
|
break
|
|
|
|
# if we're not showing inner nodes, prefer names higher in
|
|
# the tree since this avoids showing vestigial names
|
|
name = None
|
|
if not args.get('inner'):
|
|
name = None
|
|
for bid_, w_, rbyd_, rid_, tags_ in reversed(path):
|
|
for tag_, j_, d_, data_ in tags_:
|
|
if tag_ & 0x7f00 == TAG_NAME:
|
|
name = (tag_, j_, d_, data_)
|
|
|
|
if rid_-(w_-1) != 0:
|
|
break
|
|
|
|
a = root
|
|
for d, (bid, w, rbyd, rid, tags) in enumerate(path):
|
|
if not tags:
|
|
continue
|
|
|
|
b = (bid-(w-1), d, rid-(w-1),
|
|
(name if name else tags[0])[0])
|
|
|
|
# remap branches to leaves if we aren't showing
|
|
# inner branches
|
|
if not args.get('inner'):
|
|
if b not in branches:
|
|
bid, w, rbyd, rid, tags = path[-1]
|
|
if not tags:
|
|
continue
|
|
branches[b] = (
|
|
bid-(w-1), len(path)-1, rid-(w-1),
|
|
(name if name else tags[0])[0])
|
|
b = branches[b]
|
|
|
|
# found entry point?
|
|
if root is None:
|
|
root = b
|
|
a = root
|
|
|
|
tree.add(TBranch(
|
|
a=a,
|
|
b=b,
|
|
d=d,
|
|
c='b',
|
|
))
|
|
a = b
|
|
|
|
# common tree renderer
|
|
if args.get('tree') or args.get('rbyd') or args.get('btree'):
|
|
# find the max depth from the tree
|
|
t_depth = max((branch.d+1 for branch in tree), default=0)
|
|
if t_depth > 0:
|
|
t_width = 2*t_depth + 2
|
|
|
|
def treerepr(bid, w, bd, rid, tag):
|
|
if t_depth == 0:
|
|
return ''
|
|
|
|
def branchrepr(x, d, was):
|
|
for branch in tree:
|
|
if branch.d == d and branch.b == x:
|
|
if any(branch.d == d and branch.a == x
|
|
for branch in tree):
|
|
return '+-', branch.c, branch.c
|
|
elif any(branch.d == d
|
|
and x > min(branch.a, branch.b)
|
|
and x < max(branch.a, branch.b)
|
|
for branch in tree):
|
|
return '|-', branch.c, branch.c
|
|
elif branch.a < branch.b:
|
|
return '\'-', branch.c, branch.c
|
|
else:
|
|
return '.-', branch.c, branch.c
|
|
for branch in tree:
|
|
if branch.d == d and branch.a == x:
|
|
return '+ ', branch.c, None
|
|
for branch in tree:
|
|
if (branch.d == d
|
|
and x > min(branch.a, branch.b)
|
|
and x < max(branch.a, branch.b)):
|
|
return '| ', branch.c, was
|
|
if was:
|
|
return '--', was, was
|
|
return ' ', None, None
|
|
|
|
trunk = []
|
|
was = None
|
|
for d in range(t_depth):
|
|
t, c, was = branchrepr(
|
|
(bid-(w-1), bd, rid-(w-1), tag), d, was)
|
|
|
|
trunk.append('%s%s%s%s' % (
|
|
'\x1b[33m' if color and c == 'y'
|
|
else '\x1b[31m' if color and c == 'r'
|
|
else '\x1b[90m' if color and c == 'b'
|
|
else '',
|
|
t,
|
|
('>' if was else ' ') if d == t_depth-1 else '',
|
|
'\x1b[m' if color and c else ''))
|
|
|
|
return '%s ' % ''.join(trunk)
|
|
|
|
|
|
# dynamically size the id field
|
|
w_width = m.ceil(m.log10(max(1, btree.weight)+1))
|
|
|
|
# prbyd here means the last rendered rbyd, we update
|
|
# in dbg_branch to always print interleaved addresses
|
|
prbyd = None
|
|
def dbg_branch(bid, w, rbyd, rid, tags, bd):
|
|
nonlocal prbyd
|
|
|
|
# show human-readable representation
|
|
for i, (tag, j, d, data) in enumerate(tags):
|
|
print('%10s %s%*s %-*s %s' % (
|
|
'%04x.%04x:' % (rbyd.block, rbyd.trunk)
|
|
if prbyd is None or rbyd != prbyd
|
|
else '',
|
|
treerepr(bid, w, bd, rid, tag)
|
|
if args.get('tree')
|
|
or args.get('rbyd')
|
|
or args.get('btree') else '',
|
|
2*w_width+1, '' if i != 0
|
|
else '%d-%d' % (bid-(w-1), bid) if w > 1
|
|
else bid if w > 0
|
|
else '',
|
|
21+w_width, tagrepr(
|
|
tag, w if i == 0 else 0, len(data), None),
|
|
next(xxd(data, 8), '')
|
|
if not args.get('raw') and not args.get('no_truncate')
|
|
else ''))
|
|
prbyd = rbyd
|
|
|
|
# show on-disk encoding of tags/data
|
|
if args.get('raw'):
|
|
for o, line in enumerate(xxd(rbyd.data[j:j+d])):
|
|
print('%9s: %*s%*s %s' % (
|
|
'%04x' % (j + o*16),
|
|
t_width, '',
|
|
2*w_width+1, '',
|
|
line))
|
|
if args.get('raw') or args.get('no_truncate'):
|
|
for o, line in enumerate(xxd(data)):
|
|
print('%9s: %*s%*s %s' % (
|
|
'%04x' % (j+d + o*16),
|
|
t_width, '',
|
|
2*w_width+1, '',
|
|
line))
|
|
|
|
|
|
# traverse and print entries
|
|
bid = -1
|
|
prbyd = None
|
|
ppath = []
|
|
corrupted = False
|
|
while True:
|
|
done, bid, w, rbyd, rid, tags, path = btree_lookup(
|
|
bid+1, depth=args.get('depth'))
|
|
if done:
|
|
break
|
|
|
|
# print inner btree entries if requested
|
|
if args.get('inner'):
|
|
changed = False
|
|
for (x, px) in it.zip_longest(
|
|
enumerate(path[:-1]),
|
|
enumerate(ppath[:-1])):
|
|
if x is None:
|
|
break
|
|
if not (changed or px is None or x != px):
|
|
continue
|
|
changed = True
|
|
|
|
# show the inner entry
|
|
d, (bid_, w_, rbyd_, rid_, tags_) = x
|
|
dbg_branch(bid_, w_, rbyd_, rid_, tags_, d)
|
|
ppath = path
|
|
|
|
# corrupted? try to keep printing the tree
|
|
if not rbyd:
|
|
print('%04x.%04x: %*s%s%s%s' % (
|
|
rbyd.block, rbyd.trunk,
|
|
t_width, '',
|
|
'\x1b[31m' if color else '',
|
|
'(corrupted rbyd %s)' % rbyd.addr(),
|
|
'\x1b[m' if color else ''))
|
|
prbyd = rbyd
|
|
corrupted = True
|
|
continue
|
|
|
|
# if we're not showing inner nodes, prefer names higher in the tree
|
|
# since this avoids showing vestigial names
|
|
if not args.get('inner'):
|
|
name = None
|
|
for bid_, w_, rbyd_, rid_, tags_ in reversed(path):
|
|
for tag_, j_, d_, data_ in tags_:
|
|
if tag_ & 0x7f00 == TAG_NAME:
|
|
name = (tag_, j_, d_, data_)
|
|
|
|
if rid_-(w_-1) != 0:
|
|
break
|
|
|
|
if name is not None:
|
|
tags = [name] + [(tag, j, d, data)
|
|
for tag, j, d, data in tags
|
|
if tag & 0x7f00 != TAG_NAME]
|
|
|
|
# show the branch
|
|
dbg_branch(bid, w, rbyd, rid, tags, len(path)-1)
|
|
|
|
if args.get('error_on_corrupt') and corrupted:
|
|
sys.exit(2)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import argparse
|
|
import sys
|
|
parser = argparse.ArgumentParser(
|
|
description="Debug rbyd B-trees.",
|
|
allow_abbrev=False)
|
|
parser.add_argument(
|
|
'disk',
|
|
help="File containing the block device.")
|
|
parser.add_argument(
|
|
'roots',
|
|
nargs='*',
|
|
type=rbydaddr,
|
|
help="Block address of the roots of the tree.")
|
|
parser.add_argument(
|
|
'-b', '--block-size',
|
|
type=bdgeom,
|
|
help="Block size/geometry in bytes.")
|
|
parser.add_argument(
|
|
'--block-count',
|
|
type=lambda x: int(x, 0),
|
|
help="Block count in blocks.")
|
|
parser.add_argument(
|
|
'--trunk',
|
|
type=lambda x: int(x, 0),
|
|
help="Use this offset as the trunk of the tree.")
|
|
parser.add_argument(
|
|
'--color',
|
|
choices=['never', 'always', 'auto'],
|
|
default='auto',
|
|
help="When to use terminal colors. Defaults to 'auto'.")
|
|
parser.add_argument(
|
|
'-r', '--raw',
|
|
action='store_true',
|
|
help="Show the raw data including tag encodings.")
|
|
parser.add_argument(
|
|
'-T', '--no-truncate',
|
|
action='store_true',
|
|
help="Don't truncate, show the full contents.")
|
|
parser.add_argument(
|
|
'-t', '--tree',
|
|
action='store_true',
|
|
help="Show the underlying rbyd trees.")
|
|
parser.add_argument(
|
|
'-B', '--btree',
|
|
action='store_true',
|
|
help="Show the B-tree.")
|
|
parser.add_argument(
|
|
'-R', '--rbyd',
|
|
action='store_true',
|
|
help="Show the full underlying rbyd trees.")
|
|
parser.add_argument(
|
|
'-i', '--inner',
|
|
action='store_true',
|
|
help="Show inner branches.")
|
|
parser.add_argument(
|
|
'-z', '--depth',
|
|
nargs='?',
|
|
type=lambda x: int(x, 0),
|
|
const=0,
|
|
help="Depth of tree to show.")
|
|
parser.add_argument(
|
|
'-e', '--error-on-corrupt',
|
|
action='store_true',
|
|
help="Error if B-tree is corrupt.")
|
|
sys.exit(main(**{k: v
|
|
for k, v in vars(parser.parse_intermixed_args()).items()
|
|
if v is not None}))
|