linux-stable.git/net/sunrpc, branch v3.4.12

svcrpc: sends on closed socket should stop immediately

2012-09-14T17:00:19+00:00

commit f06f00a24d76e168ecb38d352126fd203937b601 upstream.

svc_tcp_sendto sets XPT_CLOSE if we fail to transmit the entire reply.
However, the XPT_CLOSE won't be acted on immediately.  Meanwhile other
threads could send further replies before the socket is really shut
down.  This can manifest as data corruption: for example, if a truncated
read reply is followed by another rpc reply, that second reply will look
to the client like further read data.

Symptoms were data corruption preceded by svc_tcp_sendto logging
something like

	kernel: rpc-srv/tcp: nfsd: sent only 963696 when sending 1048708 bytes - shutting down socket

Reported-by: Malahal Naineni 
Tested-by: Malahal Naineni 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

svcrpc: fix svc_xprt_enqueue/svc_recv busy-looping

2012-09-14T17:00:19+00:00

commit d10f27a750312ed5638c876e4bd6aa83664cccd8 upstream.

The rpc server tries to ensure that there will be room to send a reply
before it receives a request.

It does this by tracking, in xpt_reserved, an upper bound on the total
size of the replies that is has already committed to for the socket.

Currently it is adding in the estimate for a new reply *before* it
checks whether there is space available.  If it finds that there is not
space, it then subtracts the estimate back out.

This may lead the subsequent svc_xprt_enqueue to decide that there is
space after all.

The results is a svc_recv() that will repeatedly return -EAGAIN, causing
server threads to loop without doing any actual work.

Reported-by: Michael Tokarev 
Tested-by: Michael Tokarev 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

svcrpc: fix BUG() in svc_tcp_clear_pages

2012-09-14T17:00:19+00:00

commit be1e44441a560c43c136a562d49a1c9623c91197 upstream.

Examination of svc_tcp_clear_pages shows that it assumes sk_tcplen is
consistent with sk_pages[] (in particular, sk_pages[n] can't be NULL if
sk_tcplen would lead us to expect n pages of data).

svc_tcp_restore_pages zeroes out sk_pages[] while leaving sk_tcplen.
This is OK, since both functions are serialized by XPT_BUSY.  However,
that means the inconsistency must be repaired before dropping XPT_BUSY.

Therefore we should be ensuring that svc_tcp_save_pages repairs the
problem before exiting svc_tcp_recv_record on error.

Symptoms were a BUG() in svc_tcp_clear_pages.

Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: return negative value in case rpcbind client creation error

2012-08-15T15:10:05+00:00

commit caea33da898e4e14f0ba58173e3b7689981d2c0b upstream.

Without this patch kernel will panic on LockD start, because lockd_up() checks
lockd_up_net() result for negative value.
From my pow it's better to return negative value from rpcbind routines instead
of replacing all such checks like in lockd_up().

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

sunrpc: clnt: Add missing braces

2012-08-15T15:10:04+00:00

commit cac5d07e3ca696dcacfb123553cf6c722111cfd3 upstream.

Add a missing set of braces that commit 4e0038b6b24
("SUNRPC: Move clnt->cl_server into struct rpc_xprt")
forgot.

Signed-off-by: Joe Perches 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

nfs: skip commit in releasepage if we're freeing memory for fs-related reasons

2012-08-09T15:31:40+00:00

commit 5cf02d09b50b1ee1c2d536c9cf64af5a7d433f56 upstream.

We've had some reports of a deadlock where rpciod ends up with a stack
trace like this:

    PID: 2507   TASK: ffff88103691ab40  CPU: 14  COMMAND: "rpciod/14"
     #0 [ffff8810343bf2f0] schedule at ffffffff814dabd9
     #1 [ffff8810343bf3b8] nfs_wait_bit_killable at ffffffffa038fc04 [nfs]
     #2 [ffff8810343bf3c8] __wait_on_bit at ffffffff814dbc2f
     #3 [ffff8810343bf418] out_of_line_wait_on_bit at ffffffff814dbcd8
     #4 [ffff8810343bf488] nfs_commit_inode at ffffffffa039e0c1 [nfs]
     #5 [ffff8810343bf4f8] nfs_release_page at ffffffffa038bef6 [nfs]
     #6 [ffff8810343bf528] try_to_release_page at ffffffff8110c670
     #7 [ffff8810343bf538] shrink_page_list.clone.0 at ffffffff81126271
     #8 [ffff8810343bf668] shrink_inactive_list at ffffffff81126638
     #9 [ffff8810343bf818] shrink_zone at ffffffff8112788f
    #10 [ffff8810343bf8c8] do_try_to_free_pages at ffffffff81127b1e
    #11 [ffff8810343bf958] try_to_free_pages at ffffffff8112812f
    #12 [ffff8810343bfa08] __alloc_pages_nodemask at ffffffff8111fdad
    #13 [ffff8810343bfb28] kmem_getpages at ffffffff81159942
    #14 [ffff8810343bfb58] fallback_alloc at ffffffff8115a55a
    #15 [ffff8810343bfbd8] ____cache_alloc_node at ffffffff8115a2d9
    #16 [ffff8810343bfc38] kmem_cache_alloc at ffffffff8115b09b
    #17 [ffff8810343bfc78] sk_prot_alloc at ffffffff81411808
    #18 [ffff8810343bfcb8] sk_alloc at ffffffff8141197c
    #19 [ffff8810343bfce8] inet_create at ffffffff81483ba6
    #20 [ffff8810343bfd38] __sock_create at ffffffff8140b4a7
    #21 [ffff8810343bfd98] xs_create_sock at ffffffffa01f649b [sunrpc]
    #22 [ffff8810343bfdd8] xs_tcp_setup_socket at ffffffffa01f6965 [sunrpc]
    #23 [ffff8810343bfe38] worker_thread at ffffffff810887d0
    #24 [ffff8810343bfee8] kthread at ffffffff8108dd96
    #25 [ffff8810343bff48] kernel_thread at ffffffff8100c1ca

rpciod is trying to allocate memory for a new socket to talk to the
server. The VM ends up calling ->releasepage to get more memory, and it
tries to do a blocking commit. That commit can't succeed however without
a connected socket, so we deadlock.

Fix this by setting PF_FSTRANS on the workqueue task prior to doing the
socket allocation, and having nfs_release_page check for that flag when
deciding whether to do a commit call. Also, set PF_FSTRANS
unconditionally in rpc_async_schedule since that function can also do
allocations sometimes.

Signed-off-by: Jeff Layton 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: move per-net operations from svc_destroy()

2012-07-16T16:04:39+00:00

upstream commit 786185b5f8abefa6a8a16695bb4a59c164d5a071.

The idea is to separate service destruction and per-net operations,
because these are two different things and the mix looks ugly.

Notes:

1) For NFS server this patch looks ugly (sorry for that). But these
place will be rewritten soon during NFSd containerization.

2) LockD per-net counter increase int lockd_up() was moved prior to
make_socks() to make lockd_down_net() call safe in case of error.

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: new svc_bind() routine introduced

2012-07-16T16:04:39+00:00

upstream commit 9793f7c88937e7ac07305ab1af1a519225836823.

This new routine is responsible for service registration in a specified
network context.

The idea is to separate service creation from per-net operations.

Note also: since registering service with svc_bind() can fail, the
service will be destroyed and during destruction it will try to
unregister itself from rpcbind. In this case unregistration has to be
skipped.

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

rpc_pipefs: allow rpc_purge_list to take a NULL waitq pointer

2012-06-22T18:36:55+00:00

commit 92123e068efa310b09e9943ac1cfd10ff6b6d2e4 upstream.

In the event that we don't have a dentry for a rpc_pipefs pipe, we still
need to allow the queue_timeout job to clean out the queue. There's just
no waitq to wake up in that event.

Reported-by: Hans de Bruin 
Reported-by: Joerg Platte 
Signed-off-by: Jeff Layton 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

NFSv4.1: Fix a request leak on the back channel

2012-06-22T18:36:54+00:00

commit b3b02ae5865c2dcd506322e0fc6def59a042e72f upstream.

If the call to svc_process_common() fails, then the request
needs to be freed before we can exit bc_svc_process.

Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman