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commit b5381c96298d75ba66625a007e2390e2b501850d
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Author: Trond Myklebust <trond.myklebust@hammerspace.com>
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Date:   Wed Jan 29 10:45:39 2020 -0500
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    manpage: Add a description of the 'softreval' / 'nosoftreval' mount option
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    Add a description of the 'softreval' / 'nosoftreval' mount options on
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    the 'nfs' generic manpage.
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    Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
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    Signed-off-by: Steve Dickson <steved@redhat.com>
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diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man
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index 84462cd7..6f79c63a 100644
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--- a/utils/mount/nfs.man
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+++ b/utils/mount/nfs.man
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@@ -121,6 +121,36 @@ option may mitigate some of the risks of using the
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 .B soft
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 option.
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 .TP 1.5i
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+.BR softreval " / " nosoftreval
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+In cases where the NFS server is down, it may be useful to
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+allow the NFS client to continue to serve up paths and
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+attributes from cache after
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+.B retrans
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+attempts to revalidate that cache have timed out.
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+This may, for instance, be helpful when trying to unmount a
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+filesystem tree from a server that is permanently down.
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+.IP
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+It is possible to combine
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+.BR softreval
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+with the
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+.B soft
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+mount option, in which case operations that cannot be served up
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+from cache will time out and return an error after
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+.B retrans
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+attempts. The combination with the default
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+.B hard
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+mount option implies those uncached operations will continue to
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+retry until a response is received from the server.
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+.IP
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+Note: the default mount option is
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+.BR nosoftreval
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+which disallows fallback to cache when revalidation fails, and
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+instead follows the behavior dictated by the
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+.B hard
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+or
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+.B soft
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+mount option.
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+.TP 1.5i
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 .BR intr " / " nointr
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 This option is provided for backward compatibility.
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 It is ignored after kernel 2.6.25.