pNFS/flexfiles: don't report an interrupted DS connect as a DS error

If nfs4_pnfs_ds_connect() is interrupted by a signal,
nfs4_ff_layout_prepare_ds() records an NFS4ERR_NXIO error for the data
server, sends a LAYOUTERROR to the MDS and may mark the layout for
return. The data server is healthy in this case; only the calling task
was killed.

A bpftrace log of a killed task shows the connect failing with
-ERESTARTSYS, followed by a LAYOUTERROR for a data server that completed
the TCP handshake with the same client microseconds later (time in
microseconds, abridged):

  python3 rpc_create (ret)      1xx.yy.50.179:24009 err=-512
  kworker inet_sock_set_state   :735 -> 1xx.yy.50.179:24009 CLOSE -> SYN_SENT
  swapper inet_sock_set_state   :735 -> 1xx.yy.50.179:24009 SYN_SENT -> ESTABLISHED
  kworker inet_sock_set_state   :735 -> 1xx.yy.50.179:24009 ESTABLISHED -> FIN_WAIT1

  python3 nfs4_pnfs_ds_connect (ret) status=-512
  python3 nfs4_ff_layout_prepare_ds (ret) err=-512
  kworker rpc_request               nfs v4 LAYOUTERROR async task=3/6752
  kworker rpc_stats_latency         LAYOUTERROR backlog=66us rtt=315us exec=421us

Return the error to the caller without reporting a DS failure when the
connect ended with -ERESTARTSYS or -EINTR.

Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>

0 files changed, 0 insertions, 0 deletions