panic: softdep_disk_io_initiation: read

[Garrett Wollman]

Does this panic look familiar?  I'm stress-testing 5-current by
running a production news server on it, and this morning I came in to
find it had crashed.  The source is about a month old (last compiled
before I went on vacation).  Here's as much of the traceback from DDB
as I was able to write down:

cluster_wbuild(c9e2936c,4000,10,0,2)
vfs_bio_awrite(d2b37a38,0,c039d00a,8bd,0)
flushbufqueues(0,0,c039d00a,109,64)
buf_daemon(...)

I was unable to continue from the panic to get a proper crash dump.
This is the first panic observed on this machine since it was set up
three weeks ago.

-GAWollman