The next several patches introduce an API that allows transports to
choose whether the RPC client provides congestion control or whether
the transport itself provides it.
The first method we abstract is the one that serializes access to the
RPC transport to prevent the bytes from different requests from mingling
together. This method provides proper request serialization and the
opportunity to prevent new requests from being started because the
transport is congested.
The normal situation is for the transport to handle congestion control
itself. Although NFS over UDP was first, it has been recognized after
years of experience that having the transport provide congestion control
is much better than doing it in the RPC client. Thus TCP, and probably
every future transport implementation, will use the default method,
xprt_lock_write, provided in xprt.c, which does not provide any kind
of congestion control. UDP can continue using the xprt.c-provided
Van Jacobson congestion avoidance implementation.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss. Look for significant
regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Prepare the way to remove the "xprt->nocong" variable by adding a callout
to the RPC client transport switch API to handle setting RPC retransmit
timeouts.
Add a pair of generic helper functions that provide the ability to set a
simple fixed timeout, or to set a timeout based on the state of a round-
trip estimator.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss. Look for significant
regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Now we can fix up the last few places that use the "xprt->stream"
variable, and get rid of it from the rpc_xprt structure.
Test-plan:
Destructive testing (unplugging the network temporarily). Connectathon
with UDP and TCP.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Split the socket write space callback function into a TCP version and UDP
version, eliminating one dependence on the "xprt->stream" variable.
Keep the common pieces of this path in xprt.c so other transports can use
it too.
Test-plan:
Write-intensive workload on a single mount point.
Version: Thu, 11 Aug 2005 16:07:51 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean-up: change some comments to reflect the realities of the new RPC
transport switch mechanism. Get rid of unused xprt_receive() prototype.
Also, organize function prototypes in xprt.h by usage and scope.
Test-plan:
Compile kernel with CONFIG_NFS enabled.
Version: Thu, 11 Aug 2005 16:07:21 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean-up: remove only reference to xprt->pending from the socket transport
implementation. This makes a cleaner interface for other transport
implementations as well.
Test-plan:
Compile kernel with CONFIG_NFS enabled.
Version: Thu, 11 Aug 2005 16:06:52 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean-up: get rid of a name reference to sockets in the generic parts of the
RPC client by renaming the sockstate field in the rpc_xprt structure.
Test-plan:
Compile kernel with CONFIG_NFS enabled.
Version: Thu, 11 Aug 2005 16:05:53 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean-up: Replace the xprt_lock with something more aptly named. This lock
single-threads the XID and request slot reservation process.
Test-plan:
Compile kernel with CONFIG_NFS enabled.
Version: Thu, 11 Aug 2005 16:05:26 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean-up: replace a name reference to sockets in the generic parts of the RPC
client by renaming sock_lock in the rpc_xprt structure.
Test-plan:
Compile kernel with CONFIG_NFS enabled.
Version: Thu, 11 Aug 2005 16:05:00 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Introduce block header comments and a function naming convention to the
socket transport implementation. Provide a debug setting for transports
that is separate from RPCDBG_XPRT. Eliminate xprt_default_timeout().
Provide block comments for exposed interfaces in xprt.c, and eliminate
the useless obvious comments.
Convert printk's to dprintk's.
Test-plan:
Compile kernel with CONFIG_NFS enabled.
Version: Thu, 11 Aug 2005 16:04:04 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move the bulk of client-side socket-specific code into a separate source
file, net/sunrpc/xprtsock.c.
Test-plan:
Millions of fsx operations. Performance characterization such as "sio" or
"iozone". Destructive testing (unplugging the network temporarily, server
reboots). Connectathon with v2, v3, and v4.
Version: Thu, 11 Aug 2005 16:03:38 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean-up: Move some code that is common to both RPC client- and server-side
socket transports into its own source file, net/sunrpc/socklib.c.
Test-plan:
Compile kernel with CONFIG_NFS enabled. Millions of fsx operations over
UDP, client and server. Connectathon over UDP.
Version: Thu, 11 Aug 2005 16:03:09 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Implement a best practice: don't use exponential backoff when computing
retransmit timeout values on TCP connections, but simply retransmit
at regular intervals.
This also fixes a bug introduced when xprt_reset_majortimeo() was added.
Test-plan:
Enable RPC debugging and watch timeout behavior on a NFS/TCP mount.
Version: Thu, 11 Aug 2005 16:02:19 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix up xprt_connect_status: the soft timeout logic was clobbering tk_status,
so TCP connect errors were not properly reported on soft mounts.
Test-plan:
Destructive testing (unplugging the network temporarily). Connectathon
with UDP and TCP.
Version: Thu, 11 Aug 2005 16:01:28 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In __xprt_lock_write() we check to see if `task' is NULL, but in other places
we just go and dereference it.
`task' shouldn't be NULL anyway, so remove this test.
This defect was found automatically by Coverity Prevent, a static analysis
tool.
Signed-off-by: Zaur Kambarov <zkambarov@coverity.com>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make the socket transport kick the event queue to start socket connects
immediately. This should improve responsiveness of applications that are
sensitive to slow mount operations (like automounters).
We are now also careful to cancel the connect worker before destroying
the xprt. This eliminates a race where xprt_destroy can finish before
the connect worker is even allowed to run.
Test-plan:
Destructive testing (unplugging the network temporarily). Connectathon
with UDP and TCP. Hard-code impossibly small connect timeout.
Version: Fri, 29 Apr 2005 15:32:01 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When the network layer reports a connection close, the RPC task
waiting to reconnect should be notified so it can retry immediately
instead of waiting for the normal connection establishment timeout.
This reverts a change made in 2.6.6 as part of adding client support
for RPC over TCP socket idle timeouts.
Test-plan:
Destructive testing with NFS over TCP mounts.
Version: Fri, 29 Apr 2005 15:31:46 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cancel autodisconnect requests inside xprt_transmit() in order to avoid
races.
Use more efficient del_singleshot_timer_sync()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
