linux-kernel - Re: [PATCH 2.6.32 42/62] fixing infinite OPEN loop in 4.0 stateid recovery

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Message-ID: <4804EB4C-FCAE-49A7-9075-4C63D72F9AA9@netapp.com>
Date:	Mon, 14 Sep 2015 23:54:34 +0000
From:	"Kornievskaia, Olga" <Olga.Kornievskaia@...app.com>
To:	Willy Tarreau <w@....eu>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"stable@...r.kernel.org" <stable@...r.kernel.org>,
	Trond Myklebust <trond.myklebust@...marydata.com>,
	Ben Hutchings <ben@...adent.org.uk>
Subject: Re: [PATCH 2.6.32 42/62] fixing infinite OPEN loop in 4.0 stateid
 recovery

Hi Willy,

I believe the patch introduced another problem and needs to be corrected. 

> On Sep 12, 2015, at 6:56 PM, Willy Tarreau <w@....eu> wrote:
> 
> 2.6.32-longterm review patch.  If anyone has any objections, please let me know.
> 
> ------------------
> 
> From: Olga Kornievskaia <kolga@...app.com>
> 
> 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@...app.com>
> Signed-off-by: Trond Myklebust <trond.myklebust@...marydata.com>
> [bwh: Backported to 3.2: adjust context]
> Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
> (cherry picked from commit ef8500b18fc4bb03286a93b6032d56ec7bcbfd15)
> 
> Signed-off-by: Willy Tarreau <w@....eu>
> ---
> fs/nfs/nfs4state.c | 2 ++
> 1 file changed, 2 insertions(+)
> 
> diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
> index 2a7f163..71ee6f6 100644
> --- a/fs/nfs/nfs4state.c
> +++ b/fs/nfs/nfs4state.c
> @@ -929,6 +929,8 @@ restart:
> 							__func__);
> 				}
> 				nfs4_put_open_state(state);
> +				clear_bit(NFS4CLNT_RECLAIM_NOGRACE,
> +					&state->flags);
> 				goto restart;
> 			}
> 		}
> -- 
> 1.7.12.2.21.g234cd45.dirty
> 
> 
> 

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