[PATCH 3.2 018/110] fixing infinite OPEN loop in 4.0 stateid recovery

From: Ben Hutchings
Date: Mon Aug 10 2015 - 06:46:46 EST


3.2.71-rc1 review patch. If anyone has any objections, please let me know.

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

From: Olga Kornievskaia <kolga@xxxxxxxxxx>

commit e8d975e73e5fa05f983fbf2723120edcf68e0b38 upstream.

Problem: When an operation like WRITE receives a BAD_STATEID, even though
recovery code clears the RECLAIM_NOGRACE recovery flag before recovering
the open state, because of clearing delegation state for the associated
inode, nfs_inode_find_state_and_recover() gets called and it makes the
same state with RECLAIM_NOGRACE flag again. As a results, when we restart
looking over the open states, we end up in the infinite loop instead of
breaking out in the next test of state flags.

Solution: unset the RECLAIM_NOGRACE set because of
calling of nfs_inode_find_state_and_recover() after returning from calling
recover_open() function.

Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
fs/nfs/nfs4state.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1192,6 +1192,8 @@ restart:
}
spin_unlock(&state->state_lock);
nfs4_put_open_state(state);
+ clear_bit(NFS4CLNT_RECLAIM_NOGRACE,
+ &state->flags);
goto restart;
}
}

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