From: Scott Mayhew <smayhew@xxxxxxxxxx> commit 6e73e92b155c868ff7fce9d108839668caf1d9be upstream. 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: 53da6a53e1d4 ("nfsd4: catch some false session retries") Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx> Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/nfsd/nfs4state.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -3067,12 +3067,17 @@ static bool replay_matches_cache(struct (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))