spdk: do not half-close the connection before reading the response - #77
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Good, we probably need this first: #76
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Client.communicate() called conn.CloseWrite() immediately after writing
the request and before reading the reply, half-closing the write side
of the socket.
SPDK's JSON-RPC server marks conn->closed when it sees the client's
write-half EOF. Historically that was harmless because
jsonrpc_server_send_response queued the reply regardless. SPDK commit
274643bf27f2d8ac04d8326e90c17c62cd31a614 ("lib/jsonrpc: fix memory leak
on closed connection") changed that: send_response now checks
conn->closed and, when set, drops the reply instead of queuing it,
logging "attempt to send response on closed connection".
For asynchronous RPCs whose reply is produced later by a poller
(e.g. nvmf_create_transport, bdev_nvme_attach_controller), the client's
half-close is processed before the reply is ready, so with that change
the server drops the reply and the client reads a spurious EOF even
though the operation succeeded on the target.
A JSON-RPC request is self-delimiting (a single complete JSON object),
so half-closing the write side is unnecessary to frame the request.
Remove the CloseWrite and keep the connection fully open until the
single response is read.
Signed-off-by: Frankowski, Tomasz <tomasz.frankowski@intel.com>
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Client.communicate() called conn.CloseWrite() immediately after writing the request and before reading the reply, half-closing the write side of the socket.
SPDK's JSON-RPC server marks conn->closed when it sees the client's write-half EOF. Historically that was harmless because jsonrpc_server_send_response queued the reply regardless. SPDK commit 274643bf27f2d8ac04d8326e90c17c62cd31a614 ("lib/jsonrpc: fix memory leak on closed connection") changed that: send_response now checks conn->closed and, when set, drops the reply instead of queuing it, logging "attempt to send response on closed connection".
For asynchronous RPCs whose reply is produced later by a poller (e.g. nvmf_create_transport, bdev_nvme_attach_controller), the client's half-close is processed before the reply is ready, so with that change the server drops the reply and the client reads a spurious EOF even though the operation succeeded on the target.
A JSON-RPC request is self-delimiting (a single complete JSON object), so half-closing the write side is unnecessary to frame the request. Remove the CloseWrite and keep the connection fully open until the single response is read.