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56b18dfd9a03a31df3b4b5ce2d55c28e8941f214
littlefs/scripts/dbgbtree.py
Christopher Haster 56b18dfd9a Reworked revision count logic a bit, block_cycles -> block_recycles 
The original goal here was to restore all of the revision count/
wear-leveling features that were intentionally ignored during
refactoring, but over time a few other ideas to better leverage our
revision count bits crept in, so this is sort of the amalgamation of
that...

Note! None of these changes affect reading. mdir fetch strictly needs
only to look at the revision count as a big 32-bit counter to determine
which block is the most recent.

The interesting thing about the original definition of the revision
count, a simple 32-bit counter, is that it actually only needs 2-bits to
work. Well, three states really: 1. most recent, 2. less recent, 3.
future most recent. This means the remaining bits are sort of up for
grabs to other things.

Previously, we've used the extra revision count bits as a heuristic for
wear-leveling. Here we reintroduce that, a bit more rigorously, while
also carving out space for a nonce to help with commit collisions.

Here's the new revision count breakdown:

  vvvvrrrr rrrrrrnn nnnnnnnn nnnnnnnn
  '-.''----.----''---------.--------'
    '------|---------------|---------- 4-bit relocation revision
           '---------------|---------- recycle-bits recycle counter
                           '---------- pseudorandom nonce

- 4-bit relocation revision

  We technically only need 2-bits to tell which block is the most
  recent, but I've bumped it up to 4-bits just to be safe and to make
  it a bit more readable in hex form.

- recycle-bits recycle counter

  A user configurable counter, this counter tracks how many times a
  metadata block has been erased. When it overflows we return the block
  to the allocator to participate in block-level wear-leveling again.
  This implements our copy-on-bounded-write strategy.

- pseudorandom nonce

  The remaining bits we fill with a pseudorandom nonce derived from the
  filesystem's prng. Note this prng isn't the greatest (it's just the
  xor of all mdir cksums), but it gets the job done. It should also be
  reproducible, which can be a good thing.

  Suggested by ithinuel, the addition of a nonce should help with the
  commit collision issue caused by noop erases. It doesn't completely
  solve things, since we're only using crc32c cksums not collision
  resistant cryptographic hashes, but we still have the existing
  valid/perturb bit system to fall back on.

When we allocate a new mdir, we want to zero the recycle counter. This
is where our relocation revision is useful for indicating which block is
the most recent:

  initial state: 10101010 10101010 10101010 10101010
                 '-.'
                  +1     zero           random
                   v .----'----..---------'--------.
  lfsr_rev_init: 10110000 00000011 01110010 11101111

When we increment, we increment recycle counter and xor in a new nonce:

  initial state: 10110000 00000011 01110010 11101111
                 '--------.----''---------.--------'
                         +1              xor <-- random
                          v               v
  lfsr_rev_init: 10110000 00000111 01010100 01000000

And when the recycle counter overflows, we relocate the mdir.

If we aren't wear-leveling, we just increment the relocation revision to
maximize the nonce.

---

Some other notes:

- Renamed block_cycles -> block_recycles.

  This is intended to help avoid confusing block_cycles with the actual
  physical number of erase cycles supported by the device.

  I've noticed this happening a few times, and it's unfortunately
  equivalent to disabling wear-leveling completely. This can be improved
  with better documentation, but also changing the name doesn't hurt.

- We now relocate both blocks in the mdir at the same time.

  Previously we only relocated one block in the mdir per recycle. This
  was necessary to keep our threaded linked-list in sync, but the
  threaded linked-list is now no more!

  Relocating both blocks is simpler, updates the mtree less often,
  compatible with metadata redundancy, and avoids aliasing issues that
  were a problem when relocating one block.

  Note that block_recycles is internally multiplied by 2 so each block
  sees the correct number of erase cycles.

- block_recycles is now rounded down to a power-of-2.

  This makes the counter logic easier to work with and takes up less RAM
  in lfs_t. This is a rough heuristic anyways.

- Moved the lfs->seed updates into lfsr_mountinited + lfsr_mdir_commit.

  This avoids readonly operations affecting the seed and should help
  reproducibility.

- Changed rev count in dbg scripts to render as hex, similar to cksums.

  Now that we using most of the bits in the revision count, the decimal
  version is, uh, not helpful...

Code changes:

           code          stack
  before: 33342           2640
  after:  33434 (+0.3%)   2640 (+0.0%)
2024-05-22 18:49:05 -05:00

1095 lines
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#!/usr/bin/env python3
import bisect
import collections as co
import itertools as it
import math as m
import os
import struct
TAG_NULL = 0x0000
TAG_CONFIG = 0x0000
TAG_MAGIC = 0x0003
TAG_VERSION = 0x0004
TAG_RCOMPAT = 0x0005
TAG_WCOMPAT = 0x0006
TAG_OCOMPAT = 0x0007
TAG_GEOMETRY = 0x0009
TAG_NAMELIMIT = 0x000c
TAG_FILELIMIT = 0x000d
TAG_GDELTA = 0x0100
TAG_GRMDELTA = 0x0100
TAG_NAME = 0x0200
TAG_REG = 0x0201
TAG_DIR = 0x0202
TAG_BOOKMARK = 0x0204
TAG_ORPHAN = 0x0205
TAG_STRUCT = 0x0300
TAG_DATA = 0x0300
TAG_BLOCK = 0x0304
TAG_BSHRUB = 0x0308
TAG_BTREE = 0x030c
TAG_MROOT = 0x0311
TAG_MDIR = 0x0315
TAG_MTREE = 0x031c
TAG_DID = 0x0320
TAG_BRANCH = 0x032c
TAG_UATTR = 0x0400
TAG_SATTR = 0x0600
TAG_SHRUB = 0x1000
TAG_CKSUM = 0x3000
TAG_PERTURB = 0x3100
TAG_ECKSUM = 0x3200
TAG_ALT = 0x4000
TAG_R = 0x2000
TAG_GT = 0x1000
# some ways of block geometry representations
# 512 -> 512
# 512x16 -> (512, 16)
# 0x200x10 -> (512, 16)
def bdgeom(s):
s = s.strip()
b = 10
if s.startswith('0x') or s.startswith('0X'):
s = s[2:]
b = 16
elif s.startswith('0o') or s.startswith('0O'):
s = s[2:]
b = 8
elif s.startswith('0b') or s.startswith('0B'):
s = s[2:]
b = 2
if 'x' in s:
s, s_ = s.split('x', 1)
return (int(s, b), int(s_, b))
else:
return int(s, b)
# parse some rbyd addr encodings
# 0xa -> [0xa]
# 0xa.c -> [(0xa, 0xc)]
# 0x{a,b} -> [0xa, 0xb]
# 0x{a,b}.c -> [(0xa, 0xc), (0xb, 0xc)]
def rbydaddr(s):
s = s.strip()
b = 10
if s.startswith('0x') or s.startswith('0X'):
s = s[2:]
b = 16
elif s.startswith('0o') or s.startswith('0O'):
s = s[2:]
b = 8
elif s.startswith('0b') or s.startswith('0B'):
s = s[2:]
b = 2
trunk = None
if '.' in s:
s, s_ = s.split('.', 1)
trunk = int(s_, b)
if s.startswith('{') and '}' in s:
ss = s[1:s.find('}')].split(',')
else:
ss = [s]
addr = []
for s in ss:
if trunk is not None:
addr.append((int(s, b), trunk))
else:
addr.append(int(s, b))
return addr
def crc32c(data, crc=0):
crc ^= 0xffffffff
for b in data:
crc ^= b
for j in range(8):
crc = (crc >> 1) ^ ((crc & 1) * 0x82f63b78)
return 0xffffffff ^ crc
def popc(x):
return bin(x).count('1')
def parity(x):
return popc(x) & 1
def fromle32(data):
return struct.unpack('<I', data[0:4].ljust(4, b'\0'))[0]
def fromleb128(data):
word = 0
for i, b in enumerate(data):
word |= ((b & 0x7f) << 7*i)
word &= 0xffffffff
if not b & 0x80:
return word, i+1
return word, len(data)
def fromtag(data):
data = data.ljust(4, b'\0')
tag = (data[0] << 8) | data[1]
weight, d = fromleb128(data[2:])
size, d_ = fromleb128(data[2+d:])
return tag>>15, tag&0x7fff, weight, size, 2+d+d_
def frombranch(data):
d = 0
block, d_ = fromleb128(data[d:]); d += d_
trunk, d_ = fromleb128(data[d:]); d += d_
cksum = fromle32(data[d:]); d += 4
return block, trunk, cksum
def xxd(data, width=16):
for i in range(0, len(data), width):
yield '%-*s %-*s' % (
3*width,
' '.join('%02x' % b for b in data[i:i+width]),
width,
''.join(
b if b >= ' ' and b <= '~' else '.'
for b in map(chr, data[i:i+width])))
def tagrepr(tag, w=None, size=None, off=None):
if (tag & 0x6fff) == TAG_NULL:
return '%snull%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
' w%d' % w if w else '',
' %d' % size if size else '')
elif (tag & 0x6f00) == TAG_CONFIG:
return '%s%s%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
'magic' if (tag & 0xfff) == TAG_MAGIC
else 'version' if (tag & 0xfff) == TAG_VERSION
else 'rcompat' if (tag & 0xfff) == TAG_RCOMPAT
else 'wcompat' if (tag & 0xfff) == TAG_WCOMPAT
else 'ocompat' if (tag & 0xfff) == TAG_OCOMPAT
else 'geometry' if (tag & 0xfff) == TAG_GEOMETRY
else 'namelimit' if (tag & 0xfff) == TAG_NAMELIMIT
else 'filelimit' if (tag & 0xfff) == TAG_FILELIMIT
else 'config 0x%02x' % (tag & 0xff),
' w%d' % w if w else '',
' %s' % size if size is not None else '')
elif (tag & 0x6f00) == TAG_GDELTA:
return '%s%s%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
'grmdelta' if (tag & 0xfff) == TAG_GRMDELTA
else 'gdelta 0x%02x' % (tag & 0xff),
' w%d' % w if w else '',
' %s' % size if size is not None else '')
elif (tag & 0x6f00) == TAG_NAME:
return '%s%s%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
'name' if (tag & 0xfff) == TAG_NAME
else 'reg' if (tag & 0xfff) == TAG_REG
else 'dir' if (tag & 0xfff) == TAG_DIR
else 'orphan' if (tag & 0xfff) == TAG_ORPHAN
else 'bookmark' if (tag & 0xfff) == TAG_BOOKMARK
else 'name 0x%02x' % (tag & 0xff),
' w%d' % w if w else '',
' %s' % size if size is not None else '')
elif (tag & 0x6f00) == TAG_STRUCT:
return '%s%s%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
'data' if (tag & 0xfff) == TAG_DATA
else 'block' if (tag & 0xfff) == TAG_BLOCK
else 'bshrub' if (tag & 0xfff) == TAG_BSHRUB
else 'btree' if (tag & 0xfff) == TAG_BTREE
else 'mroot' if (tag & 0xfff) == TAG_MROOT
else 'mdir' if (tag & 0xfff) == TAG_MDIR
else 'mtree' if (tag & 0xfff) == TAG_MTREE
else 'did' if (tag & 0xfff) == TAG_DID
else 'branch' if (tag & 0xfff) == TAG_BRANCH
else 'struct 0x%02x' % (tag & 0xff),
' w%d' % w if w else '',
' %s' % size if size is not None else '')
elif (tag & 0x6e00) == TAG_UATTR:
return '%suattr 0x%02x%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
((tag & 0x100) >> 1) | (tag & 0xff),
' w%d' % w if w else '',
' %s' % size if size is not None else '')
elif (tag & 0x6e00) == TAG_SATTR:
return '%ssattr 0x%02x%s%s' % (
'shrub' if tag & TAG_SHRUB else '',
((tag & 0x100) >> 1) | (tag & 0xff),
' w%d' % w if w else '',
' %s' % size if size is not None else '')
elif (tag & 0x7f00) == TAG_CKSUM:
return 'cksum 0x%02x%s%s' % (
tag & 0xff,
' w%d' % w if w else '',
' %s' % size if size is not None else '')
elif (tag & 0x7f00) == TAG_PERTURB:
return 'perturb%s%s%s' % (
' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
' w%d' % w if w else '',
' %s' % size if size is not None else '')
elif (tag & 0x7f00) == TAG_ECKSUM:
return 'ecksum%s%s%s' % (
' 0x%02x' % (tag & 0xff) if tag & 0xff else '',
' w%d' % w if w else '',
' %s' % size if size is not None else '')
elif tag & TAG_ALT:
return 'alt%s%s%s%s%s' % (
'r' if tag & TAG_R else 'b',
'a' if tag & 0x0fff == 0 and tag & TAG_GT
else 'n' if tag & 0x0fff == 0
else 'gt' if tag & TAG_GT
else 'le',
' 0x%x' % (tag & 0x0fff) if tag & 0x0fff != 0 else '',
' w%d' % w if w is not None else '',
' 0x%x' % (0xffffffff & (off-size))
if size and off is not None
else ' -%d' % size if size
else '')
else:
return '0x%04x%s%s' % (
tag,
' w%d' % w if w is not None else '',
' %d' % size if size is not None else '')
# this type is used for tree representations
TBranch = co.namedtuple('TBranch', 'a, b, d, c')
# our core rbyd type
class Rbyd:
def __init__(self, block, data, rev, eoff, trunk, weight, cksum):
self.block = block
self.data = data
self.rev = rev
self.eoff = eoff
self.trunk = trunk
self.weight = weight
self.cksum = cksum
self.redund_blocks = []
def addr(self):
if not self.redund_blocks:
return '0x%x.%x' % (self.block, self.trunk)
else:
return '0x{%x,%s}.%x' % (
self.block,
','.join('%x' % block for block in self.redund_blocks),
self.trunk)
@classmethod
def fetch(cls, f, block_size, blocks, trunk=None):
if isinstance(blocks, int):
blocks = [blocks]
if len(blocks) > 1:
# fetch all blocks
rbyds = [cls.fetch(f, block_size, block, trunk) for block in blocks]
# determine most recent revision
i = 0
for i_, rbyd in enumerate(rbyds):
# compare with sequence arithmetic
if rbyd and (
not rbyds[i]
or not ((rbyd.rev - rbyds[i].rev) & 0x80000000)
or (rbyd.rev == rbyds[i].rev
and rbyd.trunk > rbyds[i].trunk)):
i = i_
# keep track of the other blocks
rbyd = rbyds[i]
rbyd.redund_blocks = [rbyds[(i+1+j) % len(rbyds)].block
for j in range(len(rbyds)-1)]
return rbyd
else:
# block may encode a trunk
block = blocks[0]
if isinstance(block, tuple):
if trunk is None:
trunk = block[1]
block = block[0]
# seek to the block
f.seek(block * block_size)
data = f.read(block_size)
# fetch the rbyd
rev = fromle32(data[0:4])
cksum = 0
cksum_ = crc32c(data[0:4])
cksum__ = cksum_
parity__ = parity(cksum_)
eoff = 0
eoff_ = None
j_ = 4
trunk_ = 0
trunk__ = 0
trunk___ = 0
weight = 0
weight_ = 0
weight__ = 0
while j_ < len(data) and (not trunk or eoff <= trunk):
v, tag, w, size, d = fromtag(data[j_:])
if v != parity__:
break
parity__ ^= parity(cksum__)
cksum__ = crc32c([data[j_] & ~0x80], cksum__)
cksum__ = crc32c(data[j_+1:j_+d], cksum__)
parity__ ^= parity(cksum__)
j_ += d
if not tag & TAG_ALT and j_ + size > len(data):
break
# take care of cksums
if not tag & TAG_ALT:
if (tag & 0xff00) != TAG_CKSUM:
parity__ ^= parity(cksum__)
cksum__ = crc32c(data[j_:j_+size], cksum__)
parity__ ^= parity(cksum__)
# found a cksum?
else:
cksum___ = fromle32(data[j_:j_+4])
if cksum__ != cksum___:
break
# commit what we have
eoff = eoff_ if eoff_ else j_ + size
cksum = cksum_
trunk_ = trunk__
weight = weight_
# revert to data cksum
cksum__ = cksum_
# evaluate trunks
if (tag & 0xf000) != TAG_CKSUM and (
not trunk or j_-d <= trunk or trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
# keep track of weight
weight__ += w
# end of trunk?
if not tag & TAG_ALT:
# update data checksum
cksum_ = cksum__
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
if not tag & TAG_ALT:
j_ += size
return cls(block, data, rev, eoff, trunk_, weight, cksum)
def lookup(self, rid, tag):
if not self:
return True, 0, -1, 0, 0, 0, b'', []
tag = max(tag, 0x1)
lower = 0
upper = self.weight
path = []
# descend down tree
j = self.trunk
while True:
_, alt, weight_, jump, d = fromtag(self.data[j:])
# found an alt?
if alt & TAG_ALT:
# follow?
if ((rid, tag & 0xfff) > (upper-weight_-1, alt & 0xfff)
if alt & TAG_GT
else ((rid, tag & 0xfff)
<= (lower+weight_-1, alt & 0xfff))):
lower += upper-lower-weight_ if alt & TAG_GT else 0
upper -= upper-lower-weight_ if not alt & TAG_GT else 0
j = j - jump
# figure out which color
if alt & TAG_R:
_, nalt, _, _, _ = fromtag(self.data[j+jump+d:])
if nalt & TAG_R:
path.append((j+jump, j, True, 'y'))
else:
path.append((j+jump, j, True, 'r'))
else:
path.append((j+jump, j, True, 'b'))
# stay on path
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 %08x, weight %d, cksum %08x' % (
btree.addr(), btree.rev, btree.weight, btree.cksum))
# 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}))
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