linux-stable.git/include/linux/sunrpc, branch linux-2.6.19.y

knfsd: Fix a race in closing NFSd connections.

2007-02-24T00:24:27+00:00

If you lose this race, it can iput a socket inode twice and you
get a BUG in fs/inode.c

When I added the option for user-space to close a socket,
I added some cruft to svc_delete_socket so that I could call
that function when closing a socket per user-space request.

This was the wrong thing to do.  I should have just set SK_CLOSE
and let normal mechanisms do the work.

Not only wrong, but buggy.  The locking is all wrong and it openned
up a race where-by a socket could be closed twice.

So this patch:
  Introduces svc_close_socket which sets SK_CLOSE then either leave
  the close up to a thread, or calls svc_delete_socket if it can
  get SK_BUSY.

  Adds a bias to sk_busy which is removed when SK_DEAD is set,
  This avoid races around shutting down the socket.

  Changes several 'spin_lock' to 'spin_lock_bh' where the _bh 
  was missing.

Bugzilla-url: http://bugzilla.kernel.org/show_bug.cgi?id=7916

Signed-off-by: Neil Brown 
Signed-off-by: Greg Kroah-Hartman

[PATCH] SUNRPC: Give cloned RPC clients their own rpc_pipefs directory

2007-02-05T16:31:45+00:00

This patch fixes a regression in 2.6.19 in which the use of multiple
krb5 mounts against the same NFS server may result in an Oops on
unmount. The Oops is due to the fact that multiple NFS krb5 clients may
end up inadvertently sharing the same rpc_pipefs upcall pipe. The first
client to 'umount' will unlink that shared pipe, causing an Oops.

The solution is to give each client their own upcall pipe. This fix has
been in mainline since 2.6.20-rc1.

Signed-off-by: Trond Myklebust 
[chrisw: backport to 2.6.19.2]
Signed-off-by: Chris Wright

[PATCH] knfsd: fix an NFSD bug with full sized, non-page-aligned reads.

2007-02-05T16:31:43+00:00

NFSd assumes that largest number of pages that will be needed
for a request+response is 2+N where N pages is the size of the largest
permitted read/write request.  The '2' are 1 for the non-data part of
the request, and 1 for the non-data part of the reply.

However, when a read request is not page-aligned, and we choose to use
->sendfile to send it directly from the page cache, we may need N+1
pages to hold the whole reply.  This can overflow and array and cause
an Oops.

This patch increases size of the array for holding pages by one and
makes sure that entry is NULL when it is not in use.

Signed-off-by: Neil Brown 
Signed-off-by: Chris Wright

[PATCH] fix svc_procfunc declaration

2006-10-20T17:26:40+00:00

svc_procfunc instances return __be32, not int

Signed-off-by: Al Viro 
Acked-by: Trond Myklebust 
Acked-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] knfsd: Allow lockd to drop replies as appropriate

2006-10-17T15:18:46+00:00

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 
Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] knfsd: tidy up up meaning of 'buffer size' in nfsd/sunrpc

2006-10-06T15:53:41+00:00

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 
Cc: "J. Bruce Fields" 
Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] knfsd: register all RPC programs with portmapper by default

2006-10-04T14:55:19+00:00

The NFSACL patches introduced support for multiple RPC services listening on
the same transport.  However, only the first of these services was registered
with portmapper.  This was perfectly fine for nfsacl, as you traditionally do
not want these to show up in a portmapper listing.

The patch below changes the default behavior to always register all services
listening on a given transport, but retains the old behavior for nfsacl
services.

Signed-off-by: Olaf Kirch 
Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] knfsd: knfsd: cache ipmap per TCP socket

2006-10-04T14:55:16+00:00

Speed up high call-rate workloads by caching the struct ip_map for the peer on
the connected struct svc_sock instead of looking it up in the ip_map cache
hashtable on every call.  This helps workloads using AUTH_SYS authentication
over TCP.

Testing was on a 4 CPU 4 NIC Altix using 4 IRIX clients, each with 16
synthetic client threads simulating an rsync (i.e.  recursive directory
listing) workload reading from an i386 RH9 install image (161480 regular files
in 10841 directories) on the server.  That tree is small enough to fill in the
server's RAM so no disk traffic was involved.  This setup gives a sustained
call rate in excess of 60000 calls/sec before being CPU-bound on the server.

Profiling showed strcmp(), called from ip_map_match(), was taking 4.8% of each
CPU, and ip_map_lookup() was taking 2.9%.  This patch drops both contribution
into the profile noise.

Note that the above result overstates this value of this patch for most
workloads.  The synthetic clients are all using separate IP addresses, so
there are 64 entries in the ip_map cache hash.  Because the kernel measured
contained the bug fixed in commit

commit 1f1e030bf75774b6a283518e1534d598e14147d4

and was running on 64bit little-endian machine, probably all of those 64
entries were on a single chain, thus increasing the cost of ip_map_lookup().

With a modern kernel you would need more clients to see the same amount of
performance improvement.  This patch has helped to scale knfsd to handle a
deployment with 2000 NFS clients.

Signed-off-by: Greg Banks 
Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] knfsd: Prepare knfsd for support of rsize/wsize of up to 1MB, over TCP

2006-10-04T14:55:16+00:00

The limit over UDP remains at 32K.  Also, make some of the apparently
arbitrary sizing constants clearer.

The biggest change here involves replacing NFSSVC_MAXBLKSIZE by a function of
the rqstp.  This allows it to be different for different protocols (udp/tcp)
and also allows it to depend on the servers declared sv_bufsiz.

Note that we don't actually increase sv_bufsz for nfs yet.  That comes next.

Signed-off-by: Greg Banks 
Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] knfsd: Avoid excess stack usage in svc_tcp_recvfrom

2006-10-04T14:55:15+00:00

..  by allocating the array of 'kvec' in 'struct svc_rqst'.

As we plan to increase RPCSVC_MAXPAGES from 8 upto 256, we can no longer
allocate an array of this size on the stack.  So we allocate it in 'struct
svc_rqst'.

However svc_rqst contains (indirectly) an array of the same type and size
(actually several, but they are in a union).  So rather than waste space, we
move those arrays out of the separately allocated union and into svc_rqst to
share with the kvec moved out of svc_tcp_recvfrom (various arrays are used at
different times, so there is no conflict).

Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds