From: Jeff Garzik <jeff@garzik.org>
To: NFS list <linux-nfs@vger.kernel.org>
Subject: Linux client misses lack of open-confirm?
Date: Fri, 21 Dec 2007 23:15:11 -0500 [thread overview]
Message-ID: <476C8F4F.7080100@garzik.org> (raw)
While debugging my NFS server, I may have caught a Linux client bug.
My server is currently buggy, in that, it never sets the
OPEN4_RESULT_CONFIRM bit after an OPEN with a new owner. Shockingly, I
can pass ~530 pynfs tests, fsx-linux [Linux v4 client], and build a
kernel [Linux v4 client] even with such brokenness. ;-)
Anyway, the Linux NFSv4 client (2.6.24-rc6) seems quite happy with this
state of affairs, right until CLOSE time, when it passes "seqid + 2" to
my server rather than the expected "seqid + 1".
Though I am quite happy that Linux managed to workaround my stupid
server and store data successfully _anyway_, I thought it was worth
commenting. I was assuming either
a) Linux would notice the lack of OPEN4_RESULT_CONFIRM and
complain accordingly, or,
b) Linux would generate a correct seqid, taking into account
the fact that it did not issue OPEN_CONFIRM.
As you can see from the wireshark-0.99.7-2.fc8 binary dump at
http://gtf.org/garzik/misc/dump.bz2 (33k compressed)
we see many examples of
C: OPEN (seqid == 0)
S: NFS4_OK
C: [perhaps some intervening READ or WRITE or *ATTR]
S: [replies as expected]
C: CLOSE (seqid == 2)
S: NFS4ERR_BAD_SEQID
If you feel this behavior is fine given a broken server, that's cool...
I just figured I would post in case somebody cared about this data point.
Jeff
P.S. I really really hate stateid/seqids at this point. RFC
nonwithstanding, they are basically undocumented. I am reduced to
poking through NFSv4 WG archives and Linux kernel code to find out what
my server should be doing. pynfs is no help here, either.
next reply other threads:[~2007-12-22 4:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-22 4:15 Jeff Garzik [this message]
2007-12-22 15:27 ` Linux client misses lack of open-confirm? Trond Myklebust
[not found] ` <1198337249.7741.52.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org>
2007-12-23 2:05 ` Jeff Garzik
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