[ 72/73] NFSv4.x: Fix handling of partially delegated locks

From: Greg Kroah-Hartman
Date: Thu May 09 2013 - 18:27:55 EST


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

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

From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>

commit c5a2a15f8146fdfe45078df7873a6dc1006b3869 upstream.

If a NFS client receives a delegation for a file after it has taken
a lock on that file, we can currently end up in a situation where
we mistakenly skip unlocking that file.

The following patch swaps an erroneous check in nfs4_proc_unlck for
whether or not the file has a delegation to one which checks whether
or not we hold a lock stateid for that file.

Reported-by: Chuck Lever <Chuck.Lever@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Tested-by: Chuck Lever <Chuck.Lever@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/nfs/nfs4proc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4553,9 +4553,9 @@ static int nfs4_proc_unlck(struct nfs4_s
if (status != 0)
goto out;
/* Is this a delegated lock? */
- if (test_bit(NFS_DELEGATED_STATE, &state->flags))
- goto out;
lsp = request->fl_u.nfs4_fl.owner;
+ if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) == 0)
+ goto out;
seqid = nfs_alloc_seqid(&lsp->ls_seqid, GFP_KERNEL);
status = -ENOMEM;
if (seqid == NULL)


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