From: Scott Mayhew <smayhew@redhat.com>
To: bfields@fieldses.org, jlayton@kernel.org
Cc: linux-nfs@vger.kernel.org
Subject: [PATCH] nfsd: CB_RECALL can race with FREE_STATEID
Date: Thu, 18 Apr 2019 09:24:00 -0400 [thread overview]
Message-ID: <20190418132400.24161-1-smayhew@redhat.com> (raw)
While trying to track down some issues involving large numbers of
delegations being recalled/revoked, I caught the server setting
SEQ4_STATUS_CB_PATH_DOWN while the client was actively responding to
CB_RECALLs. It turns out that the client had already done a
TEST_STATEID and FREE_STATEID for a delegation being recalled by the
time it received the CB_RECALL.
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
---
fs/nfsd/nfs4state.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 6a45fb00c5fc..e88e429133a8 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3958,6 +3958,14 @@ static int nfsd4_cb_recall_done(struct nfsd4_callback *cb,
rpc_delay(task, 2 * HZ);
return 0;
}
+ /*
+ * Race: client may have done a FREE_STATEID before
+ * receiving the CB_RECALL.
+ */
+ if (dp->dl_stid.sc_type == NFS4_REVOKED_DELEG_STID &&
+ refcount_read(&dp->dl_stid.sc_count) == 1 &&
+ list_empty(&dp->dl_recall_lru))
+ return 1;
/*FALLTHRU*/
default:
return -1;
--
2.17.2
next reply other threads:[~2019-04-18 13:24 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-18 13:24 Scott Mayhew [this message]
2019-04-18 15:13 ` [PATCH] nfsd: CB_RECALL can race with FREE_STATEID J. Bruce Fields
2019-04-18 20:50 ` Scott Mayhew
2019-04-18 21:37 ` J. Bruce Fields
2019-04-30 18:58 ` Scott Mayhew
2019-04-30 19:03 ` Trond Myklebust
2019-05-02 11:35 ` Scott Mayhew
2019-05-02 11:49 ` Trond Myklebust
2019-04-18 22:03 ` Trond Myklebust
2019-04-18 23:42 ` bfields
2019-04-30 18:46 ` Scott Mayhew
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