SUNRPC: Ensure we flush any closed sockets before xs_xprt_free()
authorTrond Myklebust <trond.myklebust@hammerspace.com>
Sun, 3 Apr 2022 19:58:11 +0000 (15:58 -0400)
committerTrond Myklebust <trond.myklebust@hammerspace.com>
Thu, 7 Apr 2022 20:19:47 +0000 (16:19 -0400)
commitf00432063db1a0db484e85193eccc6845435b80e
treea0e0a9341d7355b4b840521190b24f08e4d15ecd
parent830f1111d90e8770fcfad8bd5628e8ae6fecec06
SUNRPC: Ensure we flush any closed sockets before xs_xprt_free()

We must ensure that all sockets are closed before we call xprt_free()
and release the reference to the net namespace. The problem is that
calling fput() will defer closing the socket until delayed_fput() gets
called.
Let's fix the situation by allowing rpciod and the transport teardown
code (which runs on the system wq) to call __fput_sync(), and directly
close the socket.

Reported-by: Felix Fu <foyjog@gmail.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: a73881c96d73 ("SUNRPC: Fix an Oops in udp_poll()")
Cc: stable@vger.kernel.org # 5.1.x: 3be232f11a3c: SUNRPC: Prevent immediate close+reconnect
Cc: stable@vger.kernel.org # 5.1.x: 89f42494f92f: SUNRPC: Don't call connect() more than once on a TCP socket
Cc: stable@vger.kernel.org # 5.1.x
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
fs/file_table.c
include/trace/events/sunrpc.h
net/sunrpc/xprt.c
net/sunrpc/xprtsock.c