nfsd4: fix up replay_matches_cache() (6e73e92b) · Commits · 戴 / test

When running an nfs stress test, I see quite a few cached replies that don't match up with the actual request. The first comment in replay_matches_cache() makes sense, but the code doesn't seem to match... fix it. This isn't exactly a bugfix, as the server isn't required to catch every case of a false retry. So, we may as well do this, but if this is fixing a problem then that suggests there's a client bug. Fixes: ("nfsd4: catch some false session retries") Signed-off-by:

Scott Mayhew <smayhew@redhat.com> Signed-off-by:

J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4state.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -3548,12 +3548,17 @@ static bool replay_matches_cache(struct svc_rqst *rqstp,
		(bool)seq->cachethis)
		return false;
		/*
		* If there's an error than the reply can have fewer ops than
		* the call. But if we cached a reply with more ops than the
		* call you're sending us now, then this new call is clearly not
		* really a replay of the old one:
		* If there's an error then the reply can have fewer ops than
		* the call.
		*/
		if (slot->sl_opcnt < argp->opcnt)
		if (slot->sl_opcnt < argp->opcnt && !slot->sl_status)
		return false;
		/*
		* But if we cached a reply with more ops than the call you're
		* sending us now, then this new call is clearly not really a
		* replay of the old one:
		*/
		if (slot->sl_opcnt > argp->opcnt)
		return false;
		/* This is the only check explicitly called by spec: */
		if (!same_creds(&rqstp->rq_cred, &slot->sl_cred))

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