Date: Wed, 5 Apr 2000 11:42:40 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: "Jonathan M. Bresler" <jmb@hub.freebsd.org> Cc: brdean@unx.sas.com, grog@lemis.com, phk@critter.freebsd.dk, blk@skynet.be, asmodai@wxs.nl, current@FreeBSD.ORG Subject: Vinum breakage Summary (was Re: Vinum breakage) Message-ID: <200004051842.LAA79600@apollo.backplane.com> References: <20000405170350.103FC37BBA8@hub.freebsd.org>
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:Matt,
: help me understand your patch. this is how i read it at this
:time:
:
:
:Matt has just made available an early patch that corrects the vinum
:panic. is this the same vinum panic that people are claiming phk
:created with the bio/buf changes? i dont know the vinum code. i dont
:know the bio/buf code. i do see that all the code changes are to
:vinum source files. none of the changes reference the buf/bio parts
:for the kernel.
:
:the patch is against 4.0, code unaffected by phk's changes.
:the revision levels are those indicated in Matt's patch and those I
:recevied via CVSup last night.
There is a lot of confusion here, which I will straighten out:
* 3/20 - phk makes his first buffer cache commit, adding b_iocmd.
This breaks vinum, but it takes a while for people to realize it.
(see 1.46 sys/dev/vinum/vinumrequest.c and other files)
This commit is made into -current. -stable is not effected
* 3/26 - alfred fixes phk's type-o that broke vinum (1.47 vinumrequest.c,
and other files). (3/26 == last week).
* During the last week, at aroudn the same time, a panic was traced
definitively to vinum. On saturday it was traced to the raid5 code.
Some of the people using vinum, including Greg, are using it under
-current.
* Phk begins making more radical commits (to -current) on sunday.
* Confusion reigns. I don't think the later commits broke vinum again,
but at this point there were a number of people focused on vinum and
having the buffer cache ripped out from under them might have resulted
in false positives due to people using vinum as a kld rather then
building it into the kernel. I believe there was a message or two
in this regard that turned out to be a false positive.
* Greg's test machine was running -current. Greg is dead in the water
at this point (i.e. he would need to retool to -stable), and
complains mightily (and appropriately, I believe).
Despites the truth that it would be better to track the vinum bug down
in -stable, the fact remains that many people are using -current.
* I start complaining about the lack of discussion, review,
notification, or documentation prior to phk's commits.
* Phk is referenced by Brad as breaking vinum in 4.0, which is
incorrect (message-id <v04220803b50f8d254208@[195.238.1.121]>),
on 4/4, and Brad retracts this later when the mistake is realized,
also on 4/4.
(more confusion added to the mix).
* I spend five or six hours settings vinum up on my -stable test box to
try to reproduce and fix the panic on monday.
* I come up with a patch, which Greg is now reviewing & using as a
basis for the 'real' fix. This patch fixes a bug in vinum -- we
knew there was one (on saturday, see above). The only known bug
introduced by phk's commit (so far) was fixed by Alfred on 3/26.
This panic is not related to phk's commits.
My patch is relative to 4.0.
* It is currently unknown whether further breakage in -current exists
due to phk's changes. I don't think we'll know whether there are
further problems until the currently known bug fix is committed and
we see where we stand.
* I also do not know if Greg has successfully retooled his test
box to run -stable.
-Matt
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