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Re: memcpy of struct buf, or similar?
Simon Burge wrote:
> Andrew Doran wrote:
>> I am trying to fix PR 38761. [ ... ]
> FWIW, just sticking a
> before each time b_cflags is modified fails to reach single user when it
> hits genfs_getpages():
> panic: kernel diagnostic assertion "mutex_owned(&bufcache_lock)" failed: file
> "../../../../miscfs/genfs/genfs_io.c", line 418
I think thats a false positive, getiobuf gives you a fresh clean buffer,
which isn't known about to the buffer cache code (yet) Looking at the
getiobuf it already sets cflags to BC_BUSY, so doing so genfs doesn't
actually need to do so (and probably shouldn't anyway, otherwise people
might thing cflags can be played with outside of the bufcache code)
I've also seen a similar hang. I had a biolock and a biowait on the
same buffer, and bunch of tstiles.
The biowait was from an open call. The biolock was from a close call.
AFAIR the vnode was different, but the buf was the same.
show buf indicated that the buffer was flagged as done.
Since applying ad's patch to add a KASSERT for cv_has_waiters(or running
LOCKDEBUG kernel) I've not been able to repro the issue, build.sh -j8
(on a quad-core) runs to completion, even with raidframe rebuilding
All fs are ffs on raidframe mirror. / doesn't use softdep, /home does
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