linux.git/net/sunrpc/clnt.c, branch v4.2

SUNRPC: Don't reencode message if transmission failed with ENOBUFS

2015-07-03T13:42:12+00:00

If we're running out of buffer memory when transmitting data, then
we want to just delay for a moment, and then continue transmitting
the remainder of the message.

Signed-off-by: Trond Myklebust

SUNRPC: Handle connection issues correctly on the back channel

2015-06-19T17:04:13+00:00

If the back channel is disconnected, we can and should just fail the
transmission. The expectation is that the NFSv4.1 server will always
retransmit any outstanding callbacks once the connection is
re-established.

Signed-off-by: Trond Myklebust

SUNRPC: Transport fault injection

2015-06-10T22:37:26+00:00

It has been exceptionally useful to exercise the logic that handles
local immediate errors and RDMA connection loss.  To enable
developers to test this regularly and repeatably, add logic to
simulate connection loss every so often.

Fault injection is disabled by default. It is enabled with

  $ sudo echo xxx > /sys/kernel/debug/sunrpc/inject_fault/disconnect

where "xxx" is a large positive number of transport method calls
before a disconnect. A value of several thousand is usually a good
number that allows reasonable forward progress while still causing a
lot of connection drops.

These hooks are disabled when SUNRPC_DEBUG is turned off.

Signed-off-by: Chuck Lever 
Signed-off-by: Trond Myklebust

sunrpc: turn swapper_enable/disable functions into rpc_xprt_ops

2015-06-10T22:26:26+00:00

RDMA xprts don't have a sock_xprt, but an rdma_xprt, so the
xs_swapper_enable/disable functions will likely oops when fed an RDMA
xprt. Turn these functions into rpc_xprt_ops so that that doesn't
occur. For now the RDMA versions are no-ops that just return -EINVAL
on an attempt to swapon.

Cc: Chuck Lever 
Signed-off-by: Jeff Layton 
Reviewed-by: Chuck Lever 
Signed-off-by: Trond Myklebust

sunrpc: make xprt->swapper an atomic_t

2015-06-10T22:26:18+00:00

Split xs_swapper into enable/disable functions and eliminate the
"enable" flag.

Currently, it's racy if you have multiple swapon/swapoff operations
running in parallel over the same xprt. Also fix it so that we only
set it to a memalloc socket on a 0->1 transition and only clear it
on a 1->0 transition.

Cc: Mel Gorman 
Signed-off-by: Jeff Layton 
Reviewed-by: Chuck Lever 
Signed-off-by: Trond Myklebust

sunrpc: keep a count of swapfiles associated with the rpc_clnt

2015-06-10T22:26:14+00:00

Jerome reported seeing a warning pop when working with a swapfile on
NFS. The nfs_swap_activate can end up calling sk_set_memalloc while
holding the rcu_read_lock and that function can sleep.

To fix that, we need to take a reference to the xprt while holding the
rcu_read_lock, set the socket up for swapping and then drop that
reference. But, xprt_put is not exported and having NFS deal with the
underlying xprt is a bit of layering violation anyway.

Fix this by adding a set of activate/deactivate functions that take a
rpc_clnt pointer instead of an rpc_xprt, and have nfs_swap_activate and
nfs_swap_deactivate call those.

Also, add a per-rpc_clnt atomic counter to keep track of the number of
active swapfiles associated with it. When the counter does a 0->1
transition, we enable swapping on the xprt, when we do a 1->0 transition
we disable swapping on it.

This also allows us to be a bit more selective with the RPC_TASK_SWAPPER
flag. If non-swapper and swapper clnts are sharing a xprt, then we only
need to flag the tasks from the swapper clnt with that flag.

Acked-by: Mel Gorman 
Reported-by: Jerome Marchand 
Signed-off-by: Jeff Layton 
Reviewed-by: Chuck Lever 
Signed-off-by: Trond Myklebust

SUNRPC: Remove unused argument 'tk_ops' in rpc_run_bc_task

2015-06-05T15:15:42+00:00

Signed-off-by: Trond Myklebust

SUNRPC: Backchannel handle socket nospace

2015-06-02T17:30:35+00:00

If the socket was busy due to a socket nospace error, then we should
retry the send.

Signed-off-by: Trond Myklebust

sunrpc: make debugfs file creation failure non-fatal

2015-03-31T18:15:08+00:00

We currently have a problem that SELinux policy is being enforced when
creating debugfs files. If a debugfs file is created as a side effect of
doing some syscall, then that creation can fail if the SELinux policy
for that process prevents it.

This seems wrong. We don't do that for files under /proc, for instance,
so Bruce has proposed a patch to fix that.

While discussing that patch however, Greg K.H. stated:

    "No kernel code should care / fail if a debugfs function fails, so
     please fix up the sunrpc code first."

This patch converts all of the sunrpc debugfs setup code to be void
return functins, and the callers to not look for errors from those
functions.

This should allow rpc_clnt and rpc_xprt creation to work, even if the
kernel fails to create debugfs files for some reason.

Symptoms were failing krb5 mounts on systems using gss-proxy and
selinux.

Fixes: 388f0c776781 "sunrpc: add a debugfs rpc_xprt directory..."
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: J. Bruce Fields

SUNRPC: Handle EADDRINUSE on connect

2015-02-09T02:47:27+00:00

Now that we're setting SO_REUSEPORT, we still need to handle the
case where a connect() is attempted, but the old socket is still
lingering.
Essentially, all we want to do here is handle the error by waiting
a few seconds and then retrying.

Signed-off-by: Trond Myklebust