Revert "NFSv4: Remove incorrect check in can_open_delegated()"

This reverts commit 4e379d36c050b0117b5d10048be63a44f5036115.

This commit opens up a race between the recovery code and the open code.

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Cc: stable@vger.kernel # v4.0+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 9e9f781..95c5e8d 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1156,6 +1156,8 @@ static int can_open_delegated(struct nfs_delegation *delegation, fmode_t fmode)
                return 0;
        if ((delegation->type & fmode) != fmode)
                return 0;
+       if (test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags))
+               return 0;
        if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
                return 0;
        nfs_mark_delegation_referenced(delegation);