Commit Graph

327 Commits

Author SHA1 Message Date
Chuck Lever
fbf76683ff SUNRPC: relocate the creation of socket-specific tunables
Clean-up:

The RPC client currently creates some sysctls that are specific to the
socket transport.  Move those entirely into xprtsock.c.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:53 -05:00
Chuck Lever
282b32e17f SUNRPC: create stubs for xprtsock init and cleanup
Over time we will want to add some specific init and cleanup logic for the
xprtsock implementation.  Add stub routines for initialization and exit
processing.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:53 -05:00
Chuck Lever
dd4564715e SUNRPC: Rename skb_reader_t and friends
Clean-up:  hch suggested that the RPC client shouldn't pollute the name
space used by the generic skb manipulation routines in net/core/skbuff.c.

Rename a couple of types in xdr.h to adhere to this convention.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:52 -05:00
Chuck Lever
9d29231690 SUNRPC: skb_read_bits is the same as xs_tcp_copy_data
Clean-up: eliminate xs_tcp_copy_data -- it's exactly the same logic as the
common routine skb_read_bits.  The UDP and TCP socket read code now share
the same routine for copying data into an xdr_buf.

Now that skb_read_bits() is exported, rename it to avoid confusing it with
a generic skb_* function.  As these functions are XDR-specific, they should
not have names that suggest they are of generic use.  Also rename
skb_read_and_csum_bits() to be consistent.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:52 -05:00
Chuck Lever
7559c7a28f SUNRPC: Make address format buffers more generic
For now we will assume that all transports will use the address format
buffers in the rpc_xprt struct to store their addresses.  Change
rpc_peer2str() to be a generic routine to handle this, and get rid of the
print_address() op in the rpc_xprt_ops vector.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:51 -05:00
Chuck Lever
314dfd7987 SUNRPC: move saved socket callback functions to a private data structure
Move the three fields for saving socket callback functions out of the
rpc_xprt structure and into a private data structure maintained in
net/sunrpc/xprtsock.c.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:51 -05:00
Chuck Lever
7c6e066ec2 SUNRPC: Move the UDP socket bufsize parameters to a private data structure
Move the socket-specific buffer size parameters for UDP sockets to a
private data structure maintained in net/sunrpc/xprtsock.c.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:50 -05:00
Chuck Lever
c847546182 SUNRPC: Move rpc_xprt socket connect fields into private data structure
Move the socket-specific connection management fields out of the generic
rpc_xprt structure into a private data structure maintained in
net/sunrpc/xprtsock.c.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:50 -05:00
Chuck Lever
e136d0926e SUNRPC: Move TCP state flags into xprtsock.c
Move "XPRT_LAST_FRAG" and friends from xprt.h into xprtsock.c, and rename
them to use the naming scheme in use in xprtsock.c.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:50 -05:00
Chuck Lever
51971139b2 SUNRPC: Move TCP receive state variables into private data structure
Move the TCP receive state variables from the generic rpc_xprt structure to
a private structure maintained inside net/sunrpc/xprtsock.c.

Also rename a function/variable pair to refer to RPC fragment headers
instead of record markers, to be consistent with types defined in
sunrpc/*.h.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:49 -05:00
Chuck Lever
ee0ac0c227 SUNRPC: Remove sock and inet fields from rpc_xprt
The "sock" and "inet" fields are socket-specific.  Move them to a private
data structure maintained entirely within net/sunrpc/xprtsock.c

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:49 -05:00
Chuck Lever
ffc2e518c9 SUNRPC: Allocate a private data area for socket-specific rpc_xprt fields
When setting up a new transport instance, allocate enough memory for an
rpc_xprt and a private area.  As part of the same memory allocation, it
will be easy to find one, given a pointer to the other.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:48 -05:00
J. Bruce Fields
94efa93435 rpcgss: krb5: miscellaneous cleanup
Miscellaneous cosmetic fixes.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:48 -05:00
J. Bruce Fields
717757ad10 rpcgss: krb5: ignore seed
We're currently not actually using seed or seed_init.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:47 -05:00
J. Bruce Fields
d922a84a8b rpcgss: krb5: sanity check sealalg value in the downcall
The sealalg is checked in several places, giving the impression it could be
either SEAL_ALG_NONE or SEAL_ALG_DES.  But in fact SEAL_ALG_NONE seems to
be sufficient only for making mic's, and all the contexts we get must be
capable of wrapping as well.  So the sealalg must be SEAL_ALG_DES.  As
with signalg, just check for the right value on the downcall and ignore it
otherwise.  Similarly, tighten expectations for the sealalg on incoming
tokens, in case we do support other values eventually.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:47 -05:00
J. Bruce Fields
39a21dd1b0 rpcgss: krb5: clean up some goto's, etc.
Remove some unnecessary goto labels; clean up some return values; etc.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:46 -05:00
J. Bruce Fields
ca54f89645 rpcgss: simplify make_checksum
We're doing some pointless translation between krb5 constants and kernel
crypto string names.

Also clean up some related spkm3 code as necessary.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:46 -05:00
J. Bruce Fields
2818bf81a8 rpcgss: krb5: kill checksum_type, miscellaneous small cleanup
Previous changes reveal some obvious cruft.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:45 -05:00
J. Bruce Fields
5eb064f939 rpcgss: krb5: expect a constant signalg value
We also only ever receive one value of the signalg, so let's not pretend
otherwise

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:45 -05:00
J. Bruce Fields
e678e06bf8 gss: krb5: remove signalg and sealalg
We designed the krb5 context import without completely understanding the
context.  Now it's clear that there are a number of fields that we ignore,
or that we depend on having one single value.

In particular, we only support one value of signalg currently; so let's
check the signalg field in the downcall (in case we decide there's
something else we could support here eventually), but ignore it otherwise.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:44 -05:00
Olga Kornievskaia
adeb8133dd rpc: spkm3 update
This updates the spkm3 code to bring it up to date with our current
understanding of the spkm3 spec.

In doing so, we're changing the downcall format used by gssd in the spkm3 case,
which will cause an incompatilibity with old userland spkm3 support.  Since the
old code a) didn't implement the protocol correctly, and b) was never
distributed except in the form of some experimental patches from the citi web
site, we're assuming this is OK.

We do detect the old downcall format and print warning (and fail).  We also
include a version number in the new downcall format, to be used in the
future in case any further change is required.

In some more detail:

	- fix integrity support
	- removed dependency on NIDs. instead OIDs are used
	- known OID values for algorithms added.
	- fixed some context fields and types

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:44 -05:00
Olga Kornievskaia
37a4e6cb03 rpc: move process_xdr_buf
Since process_xdr_buf() is useful outside of the kerberos-specific code, we
move it to net/sunrpc/xdr.c, export it, and rename it in keeping with xdr_*
naming convention of xdr.c.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:44 -05:00
J. Bruce Fields
87d918d667 rpc: gss: fix a kmap_atomic race in krb5 code
This code is never called from interrupt context; it's always run by either
a user thread or rpciod.  So KM_SKB_SUNRPC_DATA is inappropriate here.

Thanks to Aimé Le Rouzic for capturing an oops which showed the kernel
taking an interrupt while we were in this piece of code, resulting in a
nested kmap_atomic(.,KM_SKB_SUNRPC_DATA) call from
xdr_partial_copy_from_skb().

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:43 -05:00
J. Bruce Fields
8fc7500bb8 rpc: gss: eliminate print_hexl()'s
Dumping all this data to the logs is wasteful (even when debugging is turned
off), and creates too much output to be useful when it's turned on.

Fix a minor style bug or two while we're at it.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:43 -05:00
Chuck Lever
2b577f1f14 SUNRPC: another pmap wakeup fix
Don't wake up bind waiters if a task finds that another task is already
trying to bind.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:42 -05:00
Chuck Lever
c8541ecdd5 SUNRPC: Make the transport-specific setup routine allocate rpc_xprt
Change the location where the rpc_xprt structure is allocated so each
transport implementation can allocate a private area from the same
chunk of memory.

Note also that xprt->ops->destroy, rather than xprt_destroy, is now
responsible for freeing rpc_xprt when the transport is destroyed.

Test plan:
Connectathon.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:34 -05:00
Trond Myklebust
24c5684b65 SUNRPC: Clean up xs_send_pages()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:33 -05:00
Trond Myklebust
bee57c99c3 SUNRPC: Ensure xdr_buf_read_netobj() checks for memory overruns
Also clean up the code...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:33 -05:00
Trond Myklebust
4e3e43ad14 SUNRPC: Add __(read|write)_bytes_from_xdr_buf
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:32 -05:00
Trond Myklebust
1e78957e0a SUNRPC: Clean up argument types in xdr.c
Converts various integer buffer offsets and sizes to unsigned integer.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:32 -05:00
Trond Myklebust
6d5fcb5a52 SUNRPC: Remove BKL around the RPC socket operations etc.
All internal RPC client operations should no longer depend on the BKL,
however lockd and NFS callbacks may still require it.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:30 -05:00
Trond Myklebust
bbd5a1f9fc SUNRPC: Fix up missing BKL in asynchronous RPC callback functions
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:29 -05:00
Trond Myklebust
3e32a5d99a SUNRPC: Give cloned RPC clients their own rpc_pipefs directory
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:29 -05:00
Trond Myklebust
23bf85ba43 SUNRPC: Handle the cases where rpc_alloc_iostats() fails
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:28 -05:00
Trond Myklebust
8aca67f0ae SUNRPC: Fix a potential race in rpc_wake_up_task()
Use RCU to ensure that we can safely call rpc_finish_wakeup after we've
called __rpc_do_wake_up_task. If not, there is a theoretical race, in which
the rpc_task finishes executing, and gets freed first.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:26 -05:00
Trond Myklebust
e6b3c4db6f Fix a second potential rpc_wakeup race...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-12-06 10:46:25 -05:00
Christophe Saout
cc4dc59e55 Subject: Re: [PATCH] Fix SUNRPC wakeup/execute race condition
The sunrpc scheduler contains a race condition that can let an RPC
task end up being neither running nor on any wait queue. The race takes
place between rpc_make_runnable (called from rpc_wake_up_task) and
__rpc_execute under the following condition:

First __rpc_execute calls tk_action which puts the task on some wait
queue. The task is dequeued by another process before __rpc_execute
continues its execution. While executing rpc_make_runnable exactly after
setting the task `running' bit and before clearing the `queued' bit
__rpc_execute picks up execution, clears `running' and subsequently
both functions fall through, both under the false assumption somebody
else took the job.

Swapping rpc_test_and_set_running with rpc_clear_queued in
rpc_make_runnable fixes that hole. This introduces another possible
race condition that can be handled by checking for `queued' after
setting the `running' bit.

Bug noticed on a 4-way x86_64 system under XEN with an NFSv4 server
on the same physical machine, apparently one of the few ways to hit
this race condition at all.

Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Christophe Saout <christophe@saout.de>
Signed-off-by: Trond Myklebust <trond.myklebust@fys.uio.no>
2006-12-06 10:46:24 -05:00
Arnaldo Carvalho de Melo
e69062b4f7 [SUNRPC]: Use k{mem,str}dup where applicable
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:30:20 -08:00
Al Viro
5f92a7388a [NET]: Annotate callers of the reset of checksum.h stuff.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:23:34 -08:00
Al Viro
d3bc23e7ee [NET]: Annotate callers of csum_fold() in net/*
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:23:27 -08:00
Al Viro
4806126d78 [SUNRPC]: annotate hash_ip()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:16 -08:00
Akinobu Mita
0c7bb31db0 [PATCH] sunrpc: add missing spin_unlock
auth_domain_put() forgot to unlock acquired spinlock.

Cc: Olaf Kirch <okir@monad.swb.de>
Cc: Andy Adamson <andros@citi.umich.edu>
Cc: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-06 01:46:23 -08:00
Andrew Morton
202dd45024 [PATCH] fix "sunrpc: fix refcounting problems in rpc servers"
- printk should remain dprintk

- fix coding-style.

Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-30 12:12:21 -08:00
Neil Brown
d6740df98e [PATCH] sunrpc: fix refcounting problems in rpc servers
A recent patch fixed a problem which would occur when the refcount on an
auth_domain reached zero.  This problem has not been reported in practice
despite existing in two major kernel releases because the refcount can
never reach zero.

This patch fixes the problems that stop the refcount reaching zero.

1/ We were adding to the refcount when inserting in the hash table,
   but only removing from the hashtable when the refcount reached zero.
   Obviously it never would.  So don't count the implied reference of
   being in the hash table.

2/ There are two paths on which a socket can be destroyed.  One called
   svcauth_unix_info_release().  The other didn't.  So when the other was
   taken, we can lose a reference to an ip_map which in-turn holds a
   reference to an auth_domain

   So unify the exit paths into svc_sock_put.  This highlights the fact
   that svc_delete_socket has slightly odd semantics - it does not drop
   a reference but probably should.  Fixing this need a bit more
   thought and testing.

Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-30 12:08:42 -08:00
NeilBrown
1a047060a9 [PATCH] knfsd: fix race that can disable NFS server
This patch is suitable for just about any 2.6 kernel.  It should go in
2.6.19 and 2.6.18.2 and possible even the .17 and .16 stable series.

This is a long standing bug that seems to have only recently become
apparent, presumably due to increasing use of NFS over TCP - many
distros seem to be making it the default.

The SK_CONN bit gets set when a listening socket may be ready
for an accept, just as SK_DATA is set when data may be available.

It is entirely possible for svc_tcp_accept to be called with neither
of these set.  It doesn't happen often but there is a small race in
svc_sock_enqueue as SK_CONN and SK_DATA are tested outside the
spin_lock.  They could be cleared immediately after the test and
before the lock is gained.

This normally shouldn't be a problem.  The sockets are non-blocking so
trying to read() or accept() when ther is nothing to do is not a problem.

However: svc_tcp_recvfrom makes the decision "Should I accept() or
should I read()" based on whether SK_CONN is set or not.  This usually
works but is not safe.  The decision should be based on whether it is
a TCP_LISTEN socket or a TCP_CONNECTED socket.

Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Adrian Bunk <bunk@stusta.de>
Cc: <stable@kernel.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 10:26:44 -07:00
Chuck Lever
b7766da7f7 [PATCH] SUNRPC: fix a typo
Yes, this actually passed tests the way it was.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 10:26:39 -07:00
Chuck Lever
71bdcf8056 [PATCH] SUNRPC: fix race in in-kernel RPC portmapper client
When submitting a request to a fast portmapper (such as the local rpcbind
daemon), the request can complete before the parent task is even queued up on
xprt->binding.  Fix this by queuing before submitting the rpcbind request.

Test plan:
Connectathon locking test with UDP.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 10:26:39 -07:00
NeilBrown
d343fce148 [PATCH] knfsd: Allow lockd to drop replies as appropriate
It is possible for the ->fopen callback from lockd into nfsd to find that an
answer cannot be given straight away (an upcall is needed) and so the request
has to be 'dropped', to be retried later.  That error status is not currently
propagated back.

So:
  Change nlm_fopen to return nlm error codes (rather than a private
  protocol) and define a new nlm_drop_reply code.
  Cause nlm_drop_reply to cause the rpc request to get rpc_drop_reply
  when this error comes back.
  Cause svc_process to drop a request which returns a status of
  rpc_drop_reply.

[akpm@osdl.org: fix warning storm]
Cc: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:46 -07:00
Al Viro
cfbdbab063 [PATCH] net/sunrpc/auth_gss/svcauth_gss.c endianness regression
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-10 15:37:24 -07:00
NeilBrown
c6b0a9f87b [PATCH] knfsd: tidy up up meaning of 'buffer size' in nfsd/sunrpc
There is some confusion about the meaning of 'bufsz' for a sunrpc server.
In some cases it is the largest message that can be sent or received.  In
other cases it is the largest 'payload' that can be included in a NFS
message.

In either case, it is not possible for both the request and the reply to be
this large.  One of the request or reply may only be one page long, which
fits nicely with NFS.

So we remove 'bufsz' and replace it with two numbers: 'max_payload' and
'max_mesg'.  Max_payload is the size that the server requests.  It is used
by the server to check the max size allowed on a particular connection:
depending on the protocol a lower limit might be used.

max_mesg is the largest single message that can be sent or received.  It is
calculated as the max_payload, rounded up to a multiple of PAGE_SIZE, and
with PAGE_SIZE added to overhead.  Only one of the request and reply may be
this size.  The other must be at most one page.

Cc: Greg Banks <gnb@sgi.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-06 08:53:41 -07:00