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d7bdd849ef
We've noticed a situation where an unstable TCP connection can cause the
TLS handshake to timeout waiting for userspace to complete it. When this
happens, we don't want to return from xs_tls_handshake_sync() with zero, as
this will cause the upper xprt to be set CONNECTED, and subsequent attempts
to transmit will be returned with -EPIPE. The sunrpc machine does not
recover from this situation and will spin attempting to transmit.
The return value of tls_handshake_cancel() can be used to detect a race
with completion:
* tls_handshake_cancel - cancel a pending handshake
* Return values:
* %true - Uncompleted handshake request was canceled
* %false - Handshake request already completed or not found
If true, we do not want the upper xprt to be connected, so return
-ETIMEDOUT. If false, its possible the handshake request was lost and
that may be the reason for our timeout. Again we do not want the upper
xprt to be connected, so return -ETIMEDOUT.
Ensure that we alway return an error from xs_tls_handshake_sync() if we
call tls_handshake_cancel().
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Fixes: 75eb6af7ac ("SUNRPC: Add a TCP-with-TLS RPC transport class")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.