commit 0445f92c5d537c173a54446b80d2052145de5148
author Trond Myklebust <trond.myklebust@hammerspace.com> Mon Dec 17 13:34:59 2018 -0500
committer Trond Myklebust <trond.myklebust@hammerspace.com> Tue Dec 18 11:03:57 2018 -0500
tree 23b94aa7599440d464970fe1cd85689446b84580
parent 7566ec393f4161572ba6f11ad5171fd5d59b0fbd

SUNRPC: Fix disconnection races

When the socket is closed, we need to call xprt_disconnect_done() in order
to clean up the XPRT_WRITE_SPACE flag, and wake up the sleeping tasks.

However, we also want to ensure that we don't wake them up before the socket
is closed, since that would cause thundering herd issues with everyone
piling up to retransmit before the TCP shutdown dance has completed.
Only the task that holds XPRT_LOCKED needs to wake up early in order to
allow the close to complete.

Reported-by: Dave Wysochanski <dwysocha@redhat.com>
Reported-by: Scott Mayhew <smayhew@redhat.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>