linux-kernel - [PATCH 3.14 039/130] Failing to send a CLOSE if file is opened WRONLY and server reboots on a 4.x mount

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Message-Id: <20160301234501.132240148@linuxfoundation.org>
Date:	Tue, 01 Mar 2016 23:51:03 +0000
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	<linux-kernel@...r.kernel.org>
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	<stable@...r.kernel.org>, Olga Kornievskaia <aglo@...ch.edu>,
	Trond Myklebust <trond.myklebust@...marydata.com>
Subject: [PATCH 3.14 039/130] Failing to send a CLOSE if file is opened WRONLY and server reboots on a 4.x mount

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Olga Kornievskaia <aglo@...ch.edu>

commit a41cbe86df3afbc82311a1640e20858c0cd7e065 upstream.

A test case is as the description says:
open(foobar, O_WRONLY);
sleep()  --> reboot the server
close(foobar)

The bug is because in nfs4state.c in nfs4_reclaim_open_state() a few
line before going to restart, there is
clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &state->flags).

NFS4CLNT_RECLAIM_NOGRACE is a flag for the client states not open
owner states. Value of NFS4CLNT_RECLAIM_NOGRACE is 4 which is the
value of NFS_O_WRONLY_STATE in nfs4_state->flags. So clearing it wipes
out state and when we go to close it, “call_close” doesn’t get set as
state flag is not set and CLOSE doesn’t go on the wire.

Signed-off-by: Olga Kornievskaia <aglo@...ch.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@...marydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 fs/nfs/nfs4state.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1482,7 +1482,7 @@ restart:
 					spin_unlock(&state->state_lock);
 				}
 				nfs4_put_open_state(state);
-				clear_bit(NFS4CLNT_RECLAIM_NOGRACE,
+				clear_bit(NFS_STATE_RECLAIM_NOGRACE,
 					&state->flags);
 				spin_lock(&sp->so_lock);
 				goto restart;