Re: panic: assertion: error == 0 in hammer_start_transaction

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:...
:few "RPC timeout for server 192.168.0.16" before the network starts working
:and goes on booting, but if I run the vkernel under gdb, I only get perhaps 2
:of those messages and after that nothing happens - gets stuck) which was
:semi-diskless (root on nfs, and one hammer fs partition on the first vkd, but
:since it was stuck at the RPC timeout messages it shouldn't have gotten far
:enough to mount the root, let alone the local hammer partition - unless it
:started booting sometime during the night).
:
:The backtrace:
:panic: assertion: error == 0 in hammer_start_transaction
:mp_lock = 00000000; cpuid = 0
:Trace beginning at frame 0xe28c9968
:panic(e28c998c,c02c6806,e28c9a84,c39a6738,e28c99a8) at panic+0x14d
:...
:The dump is located at leaf:~rumko/crash/{kernel,vmcore}.0
:
:The kernel was compiled on the 2nd January around noon CET ... so the sources
:should have been from around then as well.
:-- 
:Regards,
:Rumko

    Looking at the core the error code was 6, ENXIO, which implies
    the underlying block device to the HAMMER filesystem went away.

    It looks like a HAMMER mount on /mnt, backed by a VN device
    (/dev/vn0s1a):

    f_mntonname = "/mnt", '\0' <repeats 75 times>, 
    f_mntfromname = "VROOT", '\0' <repeats 74 times>, 

    vol_name = 0xe1c84080 "/dev/vn0s1a", 

    My guess is that your VN device is backed by a file over NFS
    and NFS errored out.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>