I made a simple Bash script to back up my Mac through Time Machine over network. It mounts a server through SSHFS using MacFUSE, mounts a HFS+ sparsebundle disk image inside that mount, and tells Time Machine to back up to it, unmounting them when it's done. It usually works just fine, but a kernel panic happens about once in every 6 or so times when it tries to unmount the sparsebundle disk image. The kernel panics seemed to happen both in MacOS Catalina and Big Sur. The same problem never changed even when I changed from a Macbook Air late 2015 to a 2020 MacBook Pro, so I believe the Mac hardware might be irrelevant.
Is there a way to tell if this is a problem relating to the Apple DiskImages driver, the MacFUSE kernel extension, or something different? Should I consult Apple or the maker of MacFUSE if there is no other way to correct this?
Here is the Kernel Panic backtrace:
panic(cpu 3 caller 0xffffff801ad85bc4): "wire_count == 0, m = 0xffffff8032fd02b0, obj = 0xffffff803d9b9d00\n"@/AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/xnu/xnu-7195.81.3/osfmk/vm/vm_pageout.c:7572
Backtrace (CPU 3), Frame : Return Address
0xffffffa090a739d0 : 0xffffff801acbab4d
0xffffffa090a73a20 : 0xffffff801adfd7e3
0xffffffa090a73a60 : 0xffffff801adede1a
0xffffffa090a73ab0 : 0xffffff801ac5fa2f
0xffffffa090a73ad0 : 0xffffff801acba3ed
0xffffffa090a73bf0 : 0xffffff801acba6d8
0xffffffa090a73c60 : 0xffffff801b4bef9a
0xffffffa090a73cd0 : 0xffffff801ad85bc4
0xffffffa090a73e20 : 0xffffff801b42ad4f
0xffffffa090a73e70 : 0xffffff801d2969c1
0xffffffa090a73e90 : 0xffffff801d2960aa
0xffffffa090a73eb0 : 0xffffff801d296000
0xffffffa090a73ed0 : 0xffffff801b3fc9f7
0xffffffa090a73ef0 : 0xffffff801b3f9a7d
0xffffffa090a73f30 : 0xffffff801b41691e
0xffffffa090a73f70 : 0xffffff801b415f06
0xffffffa090a73fa0 : 0xffffff801ac5f13e
Kernel Extensions in backtrace:
com.apple.driver.DiskImages(493.0)[11E51AF9-6467-39AC-89A2-A62CE763F298]@0xffffff801d295000->0xffffff801d2a0fff
dependency: com.apple.iokit.IOStorageFamily(2.1)[B5300908-BF34-3D47-8776-FB154A6DEE4C]@0xffffff801d73f000->0xffffff801d750fff
Process name corresponding to current thread: kernel_task
Boot args: -v chunklist-security-epoch=0 -chunklist-no-rev2-dev
Mac OS version:
20D74
Kernel version:
Darwin Kernel Version 20.3.0: Thu Jan 21 00:07:06 PST 2021; root:xnu-7195.81.3~1/RELEASE_X86_64
Kernel UUID: C86236B2-4976-3542-80CA-74A6B8B4BA03
KernelCache slide: 0x000000001aa00000
KernelCache base: 0xffffff801ac00000
Kernel slide: 0x000000001aa10000
Kernel text base: 0xffffff801ac10000
__HIB text base: 0xffffff801ab00000
System model name: MacBookPro16,3 (Mac-E7203C0F68AA0004)
System shutdown begun: NO
Hibernation exit count: 0
System uptime in nanoseconds: 11092066957957
Last Sleep: absolute base_tsc base_nano
Uptime : 0x00000a1692b5fd2e
Sleep : 0x00000877d70daad5 0x00000bfb283e2420 0x000008693a36c209
Wake : 0x00000877e168dd7b 0x00000c4e1fdaf8c6 0x00000877e012bf29
last started kext at 11091852477214: >!AXsanScheme 3 (addr 0xffffff801c467000, size 12288)
last stopped kext at 10623433685325: >!AXsanScheme 3 (addr 0xffffff801c467000, size 12288)
loaded kexts:
io.macfuse.filesystems.macfuse 2053.20
org.virtualbox.kext.VBoxNetAdp 6.1.18
org.virtualbox.kext.VBoxNetFlt 6.1.18
org.virtualbox.kext.VBoxUSB 6.1.18
org.virtualbox.kext.VBoxDrv 6.1.18
>AGPM 119
>!APlatformEnabler 2.7.0d0
>X86PlatformShim 1.0.0
@filesystems.autofs 3.0
@fileutil 20.036.15
>!ATopCaseHIDEventDriver 4030.5
>!AHIDALSService 1
>!AGraphicsDevicePolicy 6.2.2
>!AUpstreamUserClient 3.6.8
@AGDCPluginDisplayMetrics 6.2.2
>pmtelemetry 1
>!A!IKBLGraphics 16.0.1
>LuaHardwareAccess 1.0.16
|IOUserEthernet 1.0.1
|IO!BSerialManager 8.0.3d9
@Dont_Steal_Mac_OS_X 7.0.0
>!AHV 1
>!ADiskImages2 1
>!A!ISlowAdaptiveClocking 4.0.0
>!ABridgeAudio!C 100.2
>!A!ICFLGraphicsFramebuffer 16.0.1
>!A!IPCHPMC 2.0.1
>BridgeAudioCommunication 100.2
>!AAVEBridge 6.1
>!ABacklight 180.3
>!AThunderboltIP 4.0.3
>!AGFXHDA 100.1.431
>!AMCCSControl 1.14
@filesystems.apfs 1677.81.1
>BCMWLANFirmware4378.Hashstore 1
>BCMWLANFirmware4377.Hashstore 1
>BCMWLANFirmware4364.Hashstore 1
>BCMWLANFirmware4355.Hashstore 1
>!A!BModule 1
@filesystems.tmpfs 1
@filesystems.hfs.kext 556.60.1
@BootCache 40
@!AFSCompression.!AFSCompressionTypeZlib 1.0.0
@!AFSCompression.!AFSCompressionTypeDataless 1.0.0d1
@private.KextAudit 1.0
>!ASmartBatteryManager 161.0.0
>!ABCMWLANBusInterfacePCIeMac 1
>!AACPIButtons 6.1
>!ASMBIOS 2.1
>!AACPIEC 6.1
>!AAPIC 1.7
@!ASystemPolicy 2.0.0
@nke.applicationfirewall 310
|IOKitRegistryCompatibility 1
|EndpointSecurity 1
>!AXsanScheme 3
|IOUSBUserClient 900.4.2
@kext.triggers 1.0
>!AHIDKeyboard 223
>!AActuatorDriver 4400.28
>!AMultitouchDriver 4400.28
>!AInputDeviceSupport 4400.35
>!AHS!BDriver 4030.5
>IO!BHIDDriver 8.0.3d9
>!AGraphicsControl 6.2.2
|IOAVB!F 930.1
>X86PlatformPlugin 1.0.0
@!AGPUWrangler 6.2.2
|IOSlowAdaptiveClocking!F 1.0.0
|IOAccelerator!F2 439.52
>!A!ILpssUARTv1 3.0.60
>!A!ILpssUARTCommon 3.0.60
>!AOnboardSerial 1.0
>IOPlatformPlugin!F 6.0.0d8
@!AGraphicsDeviceControl 6.2.2
>!ABacklightExpert 1.1.0
|IONDRVSupport 585
|IOAudio!F 300.6.1
@vecLib.kext 1.2.0
|IOGraphics!F 585
>!ASMBus!C 1.0.18d1
@plugin.IOgPTPPlugin 900.11
|IOEthernetAVB!C 1.1.0
>usb.cdc.ncm 5.0.0
>usb.cdc 5.0.0
>usb.networking 5.0.0
>usb.!UHostCompositeDevice 1.2
>!AThunderboltPCIDownAdapter 4.1.1
>!AThunderboltDPInAdapter 8.1.4
>!AThunderboltDPAdapter!F 8.1.4
>!AHPM 3.4.4
>!A!ILpssI2C!C 3.0.60
>!A!ILpssDmac 3.0.60
>usb.!UVHCIBCE 1.2
>usb.!UVHCICommonBCE 1.0
>usb.!UVHCI 1.2
>usb.!UVHCICommon 1.0
>!AEffaceableNOR 1.0
|IOBufferCopy!C 1.1.0
|IOBufferCopyEngine!F 1
|IONVMe!F 2.1.0
>!AThunderboltNHI 7.2.8
|IOThunderbolt!F 9.3.2
>IO!BHost!CPCIeTransport 8.0.3d9
|IO!BHost!CTransport 8.0.3d9
>!AConvergedIPCOLYBTControl 1
>!A!BDebug 1
>!A!BDebugService 1
>!AConvergedPCI 1
>!A!ILpssI2C 3.0.60
>usb.!UXHCIPCI 1.2
>usb.!UXHCI 1.2
>!ABSDKextStarter 3
|IOSurface 289.3
@filesystems.hfs.encodings.kext 1
|IOUSB!F 900.4.2
>!AEFINVRAM 2.1
>!AMultiFunctionManagerMac 1
>!AEFIRuntime 2.1
>!ABCMWLANCoreMac 1.0.0
|IOSerial!F 11
|IO80211!FV2 1200.12.2b1
|IOSkywalk!F 1
>mDNSOffloadUserClient 1.0.1b8
>IOImageLoader 1.0.0
>corecapture 1.0.4
>!ASMCRTC 1.0
|IOSMBus!F 1.1
|IOHID!F 2.0.0
$!AImage4 3.0.0
|IOTimeSync!F 900.11
|IONetworking!F 3.4
>DiskImages 493.0.0
|IO!B!F 8.0.3d9
|IOReport!F 47
|IO!BPacketLogger 8.0.3d9
$quarantine 4
$sandbox 300.0
@kext.!AMatch 1.0.0d1
|CoreAnalytics!F 1
>!ASSE 1.0
>!AKeyStore 2
>!UTDM 511.60.2
|IOUSBMass!SDriver 184.40.6
|IOSCSIBlockCommandsDevice 436.40.6
|IO!S!F 2.1
|IOSCSIArchitectureModel!F 436.40.6
>!AMobileFileIntegrity 1.0.5
@kext.CoreTrust 1
>!AFDEKeyStore 28.30
>!AEffaceable!S 1.0
>!ACredentialManager 1.0
>KernelRelayHost 1
|IOUSBHost!F 1.2
>!UHostMergeProperties 1.2
>usb.!UCommon 1.0
>!ABusPower!C 1.0
>!ASEPManager 1.0.1
>IOSlaveProcessor 1
>!AACPIPlatform 6.1
>!ASMC 3.1.9
|IOPCI!F 2.9
|IOACPI!F 1.4
>watchdog 1
@kec.pthread 1
@kec.corecrypto 11.1
@kec.Libm 1
Best Answer
This panic signature is identical to one that I've encountered myself with sudden removal of a disk image backing store. It's a bug in the macOS disk image driver, not MacFUSE (MacFUSE wasn't installed on my machine). You should report the panic to Apple. Giving them readily reproducible steps will be key to fixing the issue.