Set memalloc_nofs_save() on all the rpciod/xprtiod jobs so that we
ensure memory allocations for asynchronous rpc calls don't ever end
up recursing back to the NFS layer for memory reclaim.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

After receiving data into the page cache, we need to call flush_dcache_page()
for the architectures that define it.

Fixes: 277e4ab7 ("SUNRPC: Simplify TCP receive code by switching...")
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.20
Tested-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up some warnings observed when building with "make W=1".
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Signed-off-by: NVasily Averin <vvs@virtuozzo.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If we want /proc/sys/sunrpc the current kernel also drags in other debug
features which we don't really want. Instead, we should always show the
following entries:

/proc/sys/sunrpc/udp_slot_table_entries
/proc/sys/sunrpc/tcp_slot_table_entries
/proc/sys/sunrpc/tcp_max_slot_table_entries
/proc/sys/sunrpc/min_resvport
/proc/sys/sunrpc/max_resvport
/proc/sys/sunrpc/tcp_fin_timeout
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: NThomas Preston <thomas.preston@codethink.co.uk>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Ensure that we clear XPRT_CONNECTING before releasing the XPRT_LOCK so that
we don't have races between the (asynchronous) socket setup code and
tasks in xprt_connect().
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>

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: NDave Wysochanski <dwysocha@redhat.com>
Reported-by: NScott Mayhew <smayhew@redhat.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>

If the connection is broken, then xs_tcp_state_change() will take care
of scheduling the socket close as soon as appropriate. xs_read_stream()
just needs to report the error.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Ensure that we do not exit the socket read callback without clearing
XPRT_SOCK_DATA_READY.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When discarding message data from the stream, we're better off using
the discard iterator, since that will work with non-TCP streams.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the allocator fails before it has reached the target number of pages,
then we need to recheck that we're not seeking past the page buffer.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

The RPC code is occasionally hanging when the receive code fails to
empty the socket buffer due to a partial read of the data. When we
convert that to an EAGAIN, it appears we occasionally leave data in the
socket. The fix is to just keep reading until the socket returns
EAGAIN/EWOULDBLOCK.
Reported-by: NCatalin Marinas <catalin.marinas@arm.com>
Reported-by: NCristian Marussi <cristian.marussi@arm.com>
Reported-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NCristian Marussi <cristian.marussi@arm.com>

sunrpc patches from nfs tree conflict with calling conventions change done
in iov_iter work.  Trivial fixup...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commits ffb6ca33 and e08ea3a9 prevent setting xprt_min_resvport
greater than xprt_max_resvport, but may also break simple code that sets
one parameter then the other, if the new range does not overlap the old.

Also it looks racy to me, unless there's some serialization I'm not
seeing.  Granted it would probably require malicious privileged processes
(unless there's a chance these might eventually be settable in unprivileged
containers), but still it seems better not to let userspace panic the
kernel.

Simpler seems to be to allow setting the parameters to whatever you want
but interpret xprt_min_resvport > xprt_max_resvport as the empty range.

Fixes: ffb6ca33 "sunrpc: Prevent resvport min/max inversion..."
Fixes: e08ea3a9 "sunrpc: Prevent rexvport min/max inversion..."
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

The way connection-oriented transports report connect_time is wrong:
it's supposed to be in seconds, not in jiffies.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

For TCP, the logic in xprt_connect_status is currently never invoked
to record a successful connection. Commit 2a491991 ("SUNRPC:
Return EAGAIN instead of ENOTCONN when waking up xprt->pending")
changed the way TCP xprt's are awoken after a connect succeeds.

Instead, change connection-oriented transports to bump connect_count
and compute connect_time the moment that XPRT_CONNECTED is set.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Simplify the retry logic.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

In preparation for sharing with AF_LOCAL.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Most of this code should also be reusable with other socket types.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Treat socket write space handling in the same way we now treat transport
congestion: by denying the XPRT_LOCK until the transport signals that it
has free buffer space.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

The theory was that we would need to grab the socket lock anyway, so we
might as well use it to gate the allocation of RPC slots for a TCP
socket.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Both RDMA and UDP transports require the request to get a "congestion control"
credit before they can be transmitted. Right now, this is done when
the request locks the socket. We'd like it to happen when a request attempts
to be transmitted for the first time.
In order to support retransmission of requests that already hold such
credits, we also want to ensure that they get queued first, so that we
don't deadlock with requests that have yet to obtain a credit.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When we shift to using the transmit queue, then the task that holds the
write lock will not necessarily be the same as the one being transmitted.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

We will use the same lock to protect both the transmit and receive queues.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the previous message was only partially transmitted, we need to close
the socket in order to avoid corruption of the message stream. To do so,
we currently hijack the unlocking of the socket in order to schedule
the close.
Now that we track the message offset in the socket state, we can move
that kind of checking out of the socket lock code, which is needed to
allow messages to remain queued after dropping the socket lock.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Rather than resetting state variables in socket state_change() callback,
do it in the sunrpc TCP connect function itself.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Since we will want to introduce similar TCP state variables for the
transmission of requests, let's rename the existing ones to label
that they are for the receive side.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Remove trailing whitespace and blank line at EOF
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Refactor: xprtrdma needs to have better control over when RPCs are
awoken from the backlog queue, so replace xprt_free_slot with a
transport op callout.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Some RPC transports have more overhead in their send_request
callouts than others. For example, for RPC-over-RDMA:

- Marshaling an RPC often has to DMA map the RPC arguments

- Registration methods perform memory registration as part of
  marshaling

To capture just server and network latencies more precisely: when
sending a Call, capture the rq_xtime timestamp _after_ the transport
header has been marshaled.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Since commit 33849792 ("xprtrdma: Detect unreachable NFS/RDMA
servers more reliably"), the xprtrdma transport now has a ->timer
callout. But xprtrdma does not need to compute RTT data, only UDP
needs that. Move the xprt_update_rtt call into the UDP transport
implementation.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Changes since v1:
Added changes in these files:
    drivers/infiniband/hw/usnic/usnic_transport.c
    drivers/staging/lustre/lnet/lnet/lib-socket.c
    drivers/target/iscsi/iscsi_target_login.c
    drivers/vhost/net.c
    fs/dlm/lowcomms.c
    fs/ocfs2/cluster/tcp.c
    security/tomoyo/network.c

Before:
All these functions either return a negative error indicator,
or store length of sockaddr into "int *socklen" parameter
and return zero on success.

"int *socklen" parameter is awkward. For example, if caller does not
care, it still needs to provide on-stack storage for the value
it does not need.

None of the many FOO_getname() functions of various protocols
ever used old value of *socklen. They always just overwrite it.

This change drops this parameter, and makes all these functions, on success,
return length of sockaddr. It's always >= 0 and can be differentiated
from an error.

Tests in callers are changed from "if (err)" to "if (err < 0)", where needed.

rpc_sockname() lost "int buflen" parameter, since its only use was
to be passed to kernel_getsockname() as &buflen and subsequently
not used in any way.

Userspace API is not changed.

    text    data     bss      dec     hex filename
30108430 2633624  873672 33615726 200ef6e vmlinux.before.o
30108109 2633612  873672 33615393 200ee21 vmlinux.o
Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
CC: David S. Miller <davem@davemloft.net>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-bluetooth@vger.kernel.org
CC: linux-decnet-user@lists.sourceforge.net
CC: linux-wireless@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: linux-sctp@vger.kernel.org
CC: linux-nfs@vger.kernel.org
CC: linux-x25@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Calling __UDPX_INC_STATS() from a preemptible context leads to a
warning of the form:

 BUG: using __this_cpu_add() in preemptible [00000000] code: kworker/u5:0/31
 caller is xs_udp_data_receive_workfn+0x194/0x270
 CPU: 1 PID: 31 Comm: kworker/u5:0 Not tainted 4.15.0-rc8-00076-g90ea9f1b #2
 Workqueue: xprtiod xs_udp_data_receive_workfn
 Call Trace:
  dump_stack+0x85/0xc1
  check_preemption_disabled+0xce/0xe0
  xs_udp_data_receive_workfn+0x194/0x270
  process_one_work+0x318/0x620
  worker_thread+0x20a/0x390
  ? process_one_work+0x620/0x620
  kthread+0x120/0x130
  ? __kthread_bind_mask+0x60/0x60
  ret_from_fork+0x24/0x30

Since we're taking a spinlock in those functions anyway, let's fix the
issue by moving the call so that it occurs under the spinlock.
Reported-by: Nkernel test robot <fengguang.wu@intel.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Ensure that we release the TCP socket once it is in the TCP_CLOSE or
TCP_TIME_WAIT state (and only then) so that we don't confuse rkhunter
and its ilk.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When reading the reply from the server, insert an explicit
cond_resched() to avoid starving higher priority tasks.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Read the TCP data in chunks of max 2MB so that we do not hog the
socket lock.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>