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Add blkptr command to sdb.
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PaulZ-98 committed Oct 7, 2021
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363 changes: 363 additions & 0 deletions sdb/commands/zfs/blkptr.py
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#
# Copyright 2019 Delphix
# Copyright 2021 Datto, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

# pylint: disable=missing-docstring

from typing import Iterable

import drgn
import sdb
from sdb.commands.zfs.internal import BF64_GET, BF64_GET_SB


class BpInfo:
"""
Store attributes of the block pointer and
get formatted representations of them.
"""

# pylint: disable=too-many-instance-attributes

ndvas = 0
level = 0
ot_type = 0
compress = 0
birth = 0
cksum = 0
byte_order = 0
gang = 0
dedup = 0
copies = ""
pbirth = 0
lsize = ""
psize = ""
crypt = ""
c0 = ""
c1 = ""
c2 = ""
c3 = ""

def set_ndvas(self, nd: int) -> None:
self.ndvas = nd

def set_initial_props(self, bp: drgn.Object) -> None:
self.level = BF64_GET(bp.blk_prop, 56, 5)
self.ot_type = int(BF64_GET(bp.blk_prop, 48, 8))
self.compress = BF64_GET(bp.blk_prop, 32, 7)
self.lsize = format(Blkptr.bp_get_lsize(bp), 'x')
self.psize = format(Blkptr.bp_get_psize(bp), 'x')
self.birth = int(bp.blk_birth)
self.cksum = BF64_GET(bp.blk_prop, 40, 8)
self.byte_order = BF64_GET(bp.blk_prop, 63, 1)
self.crypt = Blkptr.bp_get_crypt(bp, self.ot_type, self.level)
self.gang = (0 if Blkptr.bp_is_embedded(bp) else BF64_GET(
bp.blk_dva[0].dva_word[1], 63, 1))
self.dedup = BF64_GET(bp.blk_prop, 62, 1)
self.copies = Blkptr.copyname[self.ndvas]
self.pbirth = Blkptr.bp_physical_birth(bp)
self.c0 = '%x' % bp.blk_cksum.zc_word[0]
self.c1 = '%x' % bp.blk_cksum.zc_word[1]
self.c2 = '%x' % bp.blk_cksum.zc_word[2]
self.c3 = '%x' % bp.blk_cksum.zc_word[3]

def get_compstr(self) -> str:
comps = sdb.get_object("zio_compress_table")
return str(comps[self.compress].ci_name.string_().decode("utf-8"))

def get_ot_name(self) -> str:
if self.ot_type & Blkptr.DMU_OT_NEWTYPE:
if self.ot_type & Blkptr.DMU_OT_BYTESWAP_MASK > 9:
print(str(self.ot_type & Blkptr.DMU_OT_BYTESWAP_MASK))
return str(self.ot_type & Blkptr.DMU_OT_BYTESWAP_MASK)
bswaps = sdb.get_object("dmu_ot_byteswap")
swap_entry = bswaps[self.ot_type & Blkptr.DMU_OT_BYTESWAP_MASK]
byte_swap = swap_entry.ob_name.string_().decode("utf-8")
meta = "metadata" if self.ot_type & Blkptr.DMU_OT_METADATA else "data"
return "bswap %s %s" % (meta, byte_swap)
return str(
sdb.get_object("dmu_ot")[self.ot_type].ot_name.string_().decode(
"utf-8"))

def get_fill(self, bp: drgn.Object) -> int:
if Blkptr.bp_is_encrypted(bp, self.ot_type, self.level):
return BF64_GET(bp.blk_fill, 0, 32)
if Blkptr.bp_is_embedded(bp):
return 1
return int(bp.blk_fill)

def get_cksum_string(self) -> str:
cksums = sdb.get_object("zio_checksum_table")
return str(cksums[self.cksum].ci_name.string_().decode("utf-8"))

def get_endian(self) -> str:
return "BE" if self.byte_order == 0 else "LE"

def get_gang(self) -> str:
return "gang" if self.gang else "contiguous"

def get_dedup(self) -> str:
return "dedup" if self.dedup else "unique"


class Blkptr(sdb.PrettyPrinter):
"""
DESCRIPTION
Pretty-print zfs block pointers.
EXAMPLES
sdb> dbuf | head 1 | member db_blkptr | blkptr
DVA[0]=<0:2cefd5e00:20000> [L0 ZFS plain file] fletcher4 uncompressed unencrypted LE
contiguous unique single 20000L/20000P birth=1624L/1624P fill=1 cksum=3feb86d3fa14:
ff98411222361a1:7cd8eb3816d141e1:2d65ae38a67197c7
sdb> echo 0xffffa0889343c680 | blkptr
DVA[0]=<0:41e90000:30000> [L0 ZFS plain file] fletcher4 uncompressed unencrypted LE
contiguous unique single 20000L/20000P birth=10L/10P fill=1 cksum=3ffba121eb4d:
ffd4345f8d679e2:efa124922f72ec66:34642a9a05fbafef
"""

BP_EMBEDDED_TYPE_DATA = 0
BP_EMBEDDED_TYPE_REDACTED = 2

SPA_MINBLOCKSHIFT = 9
SPA_MAXBLOCKSHIFT = 24
SPA_MAXBLOCKSIZE = 1 << SPA_MAXBLOCKSHIFT
SPA_ASIZEBITS = 24
SPA_VDEVBITS = 24
SPA_LSIZEBITS = 16
SPA_PSIZEBITS = 16

TRUE = 1
FALSE = 0

DMU_OT_NEWTYPE = 128
DMU_OT_ENCRYPTED = 32
DMU_OT_METADATA = 0x40
DMU_OT_BYTESWAP_MASK = 0x1f

copyname = ['zero', 'single', 'double', 'triple']

@staticmethod
def __bp_is_authenticated(bp: drgn.Object, ot: int, level: int) -> int:
return (Blkptr.bp_uses_crypt(bp) and level > 0 and
not Blkptr.dmu_ot_is_encrypted(ot))

@staticmethod
def __bp_has_indirect_mac_checksum(bp: drgn.Object, level: int) -> int:
return Blkptr.bp_uses_crypt(bp) and level > 0

@staticmethod
def __dmu_ot_is_valid(bp: drgn.Object) -> int:
ot = BF64_GET(bp.blk_prop, 48, 8)
if ot & Blkptr.DMU_OT_NEWTYPE:
return (ot & Blkptr.DMU_OT_BYTESWAP_MASK < len(
sdb.get_object("dmu_ot_byteswap")))
return ot < len(sdb.get_object("dmu_ot"))

@staticmethod
def dmu_ot_is_encrypted(ot: int) -> int:
if ot & Blkptr.DMU_OT_NEWTYPE:
return ot & Blkptr.DMU_OT_ENCRYPTED
return int(sdb.get_object("dmu_ot")[ot].ot_encrypt)

@staticmethod
def bp_is_embedded(bp: drgn.Object) -> int:
return BF64_GET(bp.blk_prop, 39, 1)

@staticmethod
def bp_is_redacted(bp: drgn.Object) -> int:
return (Blkptr.bp_is_embedded(bp) and BF64_GET(bp.blk_prop, 40, 8)
== Blkptr.BP_EMBEDDED_TYPE_REDACTED)

@staticmethod
def bp_uses_crypt(bp: drgn.Object) -> int:
return BF64_GET(bp.blk_prop, 61, 1)

@staticmethod
def bp_is_encrypted(bp: drgn.Object, ot: int, level: int) -> int:
return (Blkptr.bp_uses_crypt(bp) and level <= 0 and
Blkptr.dmu_ot_is_encrypted(ot))

@staticmethod
def bp_get_crypt(bp: drgn.Object, ot: int, level: int) -> str:
if Blkptr.bp_is_encrypted(bp, ot, level):
return "encrypted"
if Blkptr.__bp_is_authenticated(bp, ot, level):
return "authenticated"
if Blkptr.__bp_has_indirect_mac_checksum(bp, level):
return "indirect-MAC"
return "unencrypted"

@staticmethod
def dva_is_empty(bp: drgn.Object) -> int:
return int(bp.blk_dva[0].dva_word[0] == 0 and
bp.blk_dva[0].dva_word[1] == 0)

@staticmethod
def dva_get_offset(bp: drgn.Object, which_dva: int) -> int:
return BF64_GET_SB(bp.blk_dva[which_dva].dva_word[1], 0, 63,
Blkptr.SPA_MINBLOCKSHIFT, 0)

@staticmethod
def dva_get_vdev(bp: drgn.Object, which_dva: int) -> int:
return BF64_GET(bp.blk_dva[which_dva].dva_word[0], 32,
Blkptr.SPA_VDEVBITS)

@staticmethod
def __bp_is_hole(bp: drgn.Object) -> int:
return Blkptr.bp_is_embedded(bp) != Blkptr.TRUE and Blkptr.dva_is_empty(
bp)

@staticmethod
def dva_get_asize(bp: drgn.Object, which_dva: int) -> int:
if Blkptr.bp_is_embedded(bp):
return 0
return BF64_GET_SB(bp.blk_dva[which_dva].dva_word[0], 0,
Blkptr.SPA_ASIZEBITS, Blkptr.SPA_MINBLOCKSHIFT, 0)

@staticmethod
def bp_get_ndvas(bp: drgn.Object) -> int:
ndvas = 0
for x in range(0, 3):
ndvas += Blkptr.dva_get_asize(bp, x) != 0
return ndvas

@staticmethod
def bpe_get_lsize(bp: drgn.Object) -> int:
return BF64_GET_SB(bp.blk_prop, 0, 25, 0, 1)

@staticmethod
def bp_get_lsize(bp: drgn.Object) -> int:
if Blkptr.bp_is_embedded(bp):
if BF64_GET(bp.blk_prop, 40, 8) == Blkptr.BP_EMBEDDED_TYPE_DATA:
return Blkptr.bpe_get_lsize(bp)
return 0
return BF64_GET_SB(bp.blk_prop, 0, Blkptr.SPA_LSIZEBITS,
Blkptr.SPA_MINBLOCKSHIFT, 1)

@staticmethod
def bp_get_psize(bp: drgn.Object) -> int:
if Blkptr.bp_is_embedded(bp):
return 0
return BF64_GET_SB(bp.blk_prop, 16, Blkptr.SPA_PSIZEBITS,
Blkptr.SPA_MINBLOCKSHIFT, 1)

@staticmethod
def bp_physical_birth(bp: drgn.Object) -> int:
if Blkptr.bp_is_embedded(bp):
phys = 0
else:
phys = bp.blk_phys_birth if bp.blk_phys_birth != 0 else bp.blk_birth
return int(phys)

@staticmethod
def bp_get_checksum(bp: drgn.Object) -> int:
if Blkptr.bp_is_embedded(bp):
return 2 # ZIO_CHECKSUM_OFF
return BF64_GET(bp.blk_prop, 40, 8)

@staticmethod
def bp_validate(bp: drgn.Object) -> int:
errors = 0
addr = hex(bp)
if not Blkptr.__dmu_ot_is_valid(bp):
tp = BF64_GET(bp.blk_prop, 48, 8)
print(f"blkptr at {addr} has invalid TYPE {tp}")
errors += 1
ck = Blkptr.bp_get_checksum(bp)
if ck >= len(sdb.get_object("zio_checksum_table")) or ck <= 1:
print(f"blkptr at {addr} has invalid CHECKSUM {ck}")
errors += 1
comp = BF64_GET(bp.blk_prop, 32, 7)
if comp >= len(sdb.get_object("zio_compress_table")) or comp <= 1:
print(f"blkptr at {addr} has invalid COMPRESS {comp}")
errors += 1
lsz = Blkptr.bp_get_lsize(bp)
psz = Blkptr.bp_get_psize(bp)
if lsz > Blkptr.SPA_MAXBLOCKSIZE:
print(f"blkptr at {addr} has invalid LSIZE {lsz}")
errors += 1
if psz > Blkptr.SPA_MAXBLOCKSIZE:
print(f"blkptr at {addr} has invalid PSIZE {psz}")
errors += 1
if Blkptr.bp_is_embedded(bp):
etype = BF64_GET(bp.blk_prop, 40, 8)
if etype >= 3:
print(f"blkptr at {addr} has invalid ETYPE {etype}")
errors += 1
return errors

names = ["blkptr"]
input_type = "blkptr_t *"

def pretty_print(self, objs: Iterable[drgn.Object]) -> None:
for bp in objs:
if bp is None:
print("<NULL>")
continue
if not Blkptr.__bp_is_hole(bp) and Blkptr.bp_validate(bp) != 0:
continue
bpi = BpInfo()
if Blkptr.bp_is_embedded(bp) != 0:
bpi.set_ndvas(0)
else:
bpi.set_ndvas(Blkptr.bp_get_ndvas(bp))
for i in range(0, bpi.ndvas):
vdev = Blkptr.dva_get_vdev(bp, i)
offset = format(Blkptr.dva_get_offset(bp, i), 'x')
asize = format(Blkptr.dva_get_asize(bp, i), 'x')
print(f"DVA[{i}]=<{vdev}:{offset}:{asize}> ", end='')

bpi.set_initial_props(bp)

if Blkptr.bp_is_embedded(bp) != 0:
etype = BF64_GET(bp.blk_prop, 40, 8)
lsize = format(BF64_GET_SB(bp.blk_prop, 0, 25, 0, 1), 'x')
psize = format(BF64_GET_SB(bp.blk_prop, 25, 7, 0, 1), 'x')
print(
f"EMBEDDED [L{bpi.level} {bpi.get_ot_name()}] et={etype} ",
end='')
print(f"{bpi.get_compstr()} size=", end='')
print(f"{lsize}L/{psize}P birth={bpi.birth}L")
continue
if Blkptr.__bp_is_hole(bp):
print(
f"HOLE [L{bpi.level} {bpi.get_ot_name()}] size={bpi.lsize}L ",
end='')
print(f"birth={bpi.birth}L")
continue
if Blkptr.bp_is_redacted(bp):
print(
f"REDACTED [L{bpi.level} {bpi.get_ot_name()}] size={bpi.lsize}L ",
end='')
print(f"birth={bpi.birth}L")
continue

print(
f"[L{bpi.level} {bpi.get_ot_name()}] {bpi.get_cksum_string()}",
end='')
print(
f" {bpi.get_compstr()} {bpi.crypt} {bpi.get_endian()} {bpi.get_gang()}",
end='')
print(f" {bpi.get_dedup()} {bpi.copies} {bpi.lsize}L/{bpi.psize}P ",
end='')
print(f"birth={bpi.birth}L/{bpi.pbirth}P", end='')
print(
f" fill={bpi.get_fill(bp)} cksum={bpi.c0}:{bpi.c1}:{bpi.c2}:{bpi.c3}"
)
4 changes: 4 additions & 0 deletions sdb/commands/zfs/internal/__init__.py
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,10 @@ def BF64_GET(x: drgn.Object, low: int, length: int) -> int:
return BF64_DECODE(x, low, length)


def BF64_GET_SB(x: int, low: int, length: int, shift: int, bias: int) -> int:
return (BF64_GET(x, low, length) + bias) << shift


def WEIGHT_IS_SPACEBASED(weight: int) -> bool:
return weight == 0 or (BF64_GET(weight, 60, 1) != 0)

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blkptr at 0xffffa088ce68c040 has invalid CHECKSUM 0
blkptr at 0xffffa088ce68c040 has invalid COMPRESS 0
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@@ -0,0 +1 @@
HOLE [L0 unallocated] size=200L birth=0L
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@@ -0,0 +1 @@
DVA[0]=<0:2cefd5e00:20000> [L0 ZFS plain file] fletcher4 uncompressed unencrypted LE contiguous unique single 20000L/20000P birth=1624L/1624P fill=1 cksum=3feb86d3fa14:ff98411222361a1:7cd8eb3816d141e1:2d65ae38a67197c7
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DVA[0]=<0:80001e00:200> DVA[1]=<0:a0001e00:200> DVA[2]=<0:10000da00:200> [L0 DMU objset] fletcher4 lz4 unencrypted LE contiguous unique triple 1000L/200P birth=609L/609P fill=67 cksum=98a43f544:3eab35f140c:d164e4328324:1da8f37ef09087
2 changes: 2 additions & 0 deletions tests/integration/test_linux_generic.py
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Expand Up @@ -68,6 +68,8 @@
"slabs | pp",
"slabs -s util | slabs",
"slabs | head 2 | slabs",
'slabs | filter \'obj.name == "dnode_t"\' |walk | tail 8 | head 1 | cast dnode_t * | deref |member dn_phys |member dn_blkptr[0] |blkptr',
'slabs | filter \'obj.name == "dnode_t"\' |walk | head 6056 | tail 1| cast dnode_t * | deref |member dn_phys |member dn_blkptr[0] |blkptr',

# slub
'slabs | filter \'obj.name == "zio_cache"\' | slub_cache',
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