mount(1) at boot hangs in spa_namespace_lock

Gang,

for a few weeks now I can't get a CURRENT system to boot. I am using the
zfsloader and have root fs on ZFS. This has worked flawlessly for more
than a year.

The last message printed is "Mounting local file systems:" (from
rc.d/mountcritlocal) and the system hangs until I push reset. Ctrl-C etc
are ignored. However, CTRL-T says that mount is running in
spa_namespace_lock, and the "r"untime increases at 1 second per second
which looks like it is busy spinning on that lock.

What can I do to diagnose and solve it? I do have a customized
kernel config, which lookslike this. Anything wrong with it?

# grep '^[^#]' sys/amd64/conf/HAL9000
cpu             HAMMER
ident HAL9000
makeoptions     DEBUG=-g                # Build kernel with gdb(1) debug symbols
makeoptions     WITH_CTF=1              # Run ctfconvert(1) for DTrace support
options         SCHED_ULE               # ULE scheduler
options         PREEMPTION              # Enable kernel thread preemption
options         INET                    # InterNETworking
options         INET6                   # IPv6 communications protocols
options         IPSEC                   # IP (v4/v6) security
options         TCP_OFFLOAD             # TCP offload
options         SCTP                    # Stream Control Transmission Protocol
options         FFS                     # Berkeley Fast Filesystem
options         SOFTUPDATES             # Enable FFS soft updates support
options         UFS_ACL                 # Support for access control lists
options         UFS_DIRHASH             # Improve performance on big directories
options         UFS_GJOURNAL            # Enable gjournal-based UFS journaling
options         QUOTA                   # Enable disk quotas for UFS
options         MD_ROOT                 # MD is a potential root device
options         NFSCL                   # Network Filesystem Client
options         NFSD                    # Network Filesystem Server
options         NFSLOCKD                # Network Lock Manager
options         NFS_ROOT                # NFS usable as /, requires NFSCL
options         MSDOSFS                 # MSDOS Filesystem
options         CD9660                  # ISO 9660 Filesystem
options         PROCFS                  # Process filesystem (requires PSEUDOFS)
options         PSEUDOFS                # Pseudo-filesystem framework
options         GEOM_PART_GPT           # GUID Partition Tables.
options         GEOM_RAID               # Soft RAID functionality.
options         GEOM_LABEL              # Provides labelization
options         COMPAT_FREEBSD32        # Compatible with i386 binaries
options         SCSI_DELAY=5000         # Delay (in ms) before probing SCSI
options         KTRACE                  # ktrace(1) support
options         STACK                   # stack(9) support
options         SYSVSHM                 # SYSV-style shared memory
options         SYSVMSG                 # SYSV-style message queues
options         SYSVSEM                 # SYSV-style semaphores
options         _KPOSIX_PRIORITY_SCHEDULING # POSIX P1003_1B real-time extensions
options         PRINTF_BUFR_SIZE=128    # Prevent printf output being interspersed.
options         KBD_INSTALL_CDEV        # install a CDEV entry in /dev
options         HWPMC_HOOKS             # Necessary kernel hooks for hwpmc(4)
options         MAC                     # TrustedBSD MAC Framework
options         KDTRACE_FRAME           # Ensure frames are compiled in
options         KDTRACE_HOOKS           # Kernel DTrace hooks
options         DDB_CTF                 # Kernel ELF linker loads CTF data
options         INCLUDE_CONFIG_FILE     # Include this file in kernel
options         RACCT                   # Resource accounting framework
options         RACCT_DEFAULT_TO_DISABLED # Set kern.racct.enable=0 by default
options         RCTL                    # Resource limits
options         KDB                     # Enable kernel debugger support.
options         KDB_TRACE               # Print a stack trace for a panic.
options         DDB                     # Support DDB.
options         MALLOC_DEBUG_MAXZONES=8 # Separate malloc(9) zones
options         SMP                     # Symmetric MultiProcessor Kernel
device          cpufreq
device          acpi
options         ACPI_DMAR
device          pci
options         PCI_IOV                 # PCI SR-IOV support
device          ahci                    # AHCI-compatible SATA controllers
device          ata                     # Legacy ATA/SATA controllers
options         ATA_STATIC_ID           # Static device numbering
device          scbus                   # SCSI bus (required for ATA/SCSI)
device          ch                      # SCSI media changers
device          da                      # Direct Access (disks)
device          sa                      # Sequential Access (tape etc)
device          cd                      # CD
device          pass                    # Passthrough device (direct ATA/SCSI access)
device          ses                     # Enclosure Services (SES and SAF-TE)
device          atkbdc                  # AT keyboard controller
device          atkbd                   # AT keyboard
device          psm                     # PS/2 mouse
device          kbdmux                  # keyboard multiplexer
device          vga                     # VGA video card driver
options         VESA                    # Add support for VESA BIOS Extensions (VBE)
device          splash                  # Splash screen and screen saver support
device          sc
device          vt
device          vt_vga
device          vt_efifb
device          agp                     # support several AGP chipsets
device          ppbus                   # Parallel port bus (required)
device          miibus                  # MII bus support
device          loop                    # Network loopback
device          random                  # Entropy device
device          padlock_rng             # VIA Padlock RNG
device          rdrand_rng              # Intel Bull Mountain RNG
device          ether                   # Ethernet support
device          vlan                    # 802.1Q VLAN support
device          tun                     # Packet tunnel.
device          md                      # Memory "disks"
device          firmware                # firmware assist module
device          bpf                     # Berkeley packet filter
options         USB_DEBUG               # enable debug msgs
device          uhci                    # UHCI PCI->USB interface
device          ohci                    # OHCI PCI->USB interface
device          ehci                    # EHCI PCI->USB interface (USB 2.0)
device          xhci                    # XHCI PCI->USB interface (USB 3.0)
device          usb                     # USB Bus (required)
device          ukbd                    # Keyboard
device          umass                   # Disks/Mass storage - Requires scbus and da
device          sound                   # Generic sound driver (required)
device          virtio                  # Generic VirtIO bus (required)
device          virtio_pci              # VirtIO PCI device
device          vtnet                   # VirtIO Ethernet device
device          virtio_blk              # VirtIO Block device
device          virtio_scsi             # VirtIO SCSI device
device          virtio_balloon          # VirtIO Memory Balloon device
options         HYPERV                  # Hyper-V kernel infrastructure
device          hyperv                  # HyperV drivers
options         XENHVM                  # Xen HVM kernel infrastructure
device          xenpci                  # Xen HVM Hypervisor services driver
device          netmap                  # netmap(4) support
device          crypto                  # Required by IPSEC
options         EXT2FS
options         IPFIREWALL
options         IPFIREWALL_VERBOSE
options         IPFIREWALL_VERBOSE_LIMIT=100
options         IPDIVERT



Regards,

	Jens
-- 
Jens Schweikhardt http://www.schweikhardt.net/
SIGSIG -- signature too long (core dumped)