linux-stable.git/net/sunrpc, branch v3.0.63

SUNRPC: Ensure that we free the rpc_task after cleanups are done

2013-01-17T16:43:55+00:00

commit c6567ed1402c55e19b012e66a8398baec2a726f3 upstream.

This patch ensures that we free the rpc_task after the cleanup callbacks
are done in order to avoid a deadlock problem that can be triggered if
the callback needs to wait for another workqueue item to complete.

Signed-off-by: Trond Myklebust 
Cc: Weston Andros Adamson 
Cc: Tejun Heo 
Cc: Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Prevent races in xs_abort_connection()

2012-10-31T16:51:34+00:00

commit 4bc1e68ed6a8b59be8a79eb719be515a55c7bc68 upstream.

The call to xprt_disconnect_done() that is triggered by a successful
connection reset will trigger another automatic wakeup of all tasks
on the xprt->pending rpc_wait_queue. In particular it will cause an
early wake up of the task that called xprt_connect().

All we really want to do here is clear all the socket-specific state
flags, so we split that functionality out of xs_sock_mark_closed()
into a helper that can be called by xs_abort_connection()

Reported-by: Chris Perl 
Signed-off-by: Trond Myklebust 
Tested-by: Chris Perl 
Signed-off-by: Greg Kroah-Hartman

Revert "SUNRPC: Ensure we close the socket on EPIPE errors too..."

2012-10-31T16:51:34+00:00

commit b9d2bb2ee537424a7f855e1f93eed44eb9ee0854 upstream.

This reverts commit 55420c24a0d4d1fce70ca713f84aa00b6b74a70e.
Now that we clear the connected flag when entering TCP_CLOSE_WAIT,
the deadlock described in this commit is no longer possible.
Instead, the resulting call to xs_tcp_shutdown() can interfere
with pending reconnection attempts.

Reported-by: Chris Perl 
Signed-off-by: Trond Myklebust 
Tested-by: Chris Perl 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Clear the connect flag when socket state is TCP_CLOSE_WAIT

2012-10-31T16:51:34+00:00

commit d0bea455dd48da1ecbd04fedf00eb89437455fdc upstream.

This is needed to ensure that we call xprt_connect() upon the next
call to call_connect().

Signed-off-by: Trond Myklebust 
Tested-by: Chris Perl 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Get rid of the xs_error_report socket callback

2012-10-31T16:51:34+00:00

commit f878b657ce8e7d3673afe48110ec208a29e38c4a upstream.

Chris Perl reports that we're seeing races between the wakeup call in
xs_error_report and the connect attempts. Basically, Chris has shown
that in certain circumstances, the call to xs_error_report causes the
rpc_task that is responsible for reconnecting to wake up early, thus
triggering a disconnect and retry.

Since the sk->sk_error_report() calls in the socket layer are always
followed by a tcp_done() in the cases where we care about waking up
the rpc_tasks, just let the state_change callbacks take responsibility
for those wake ups.

Reported-by: Chris Perl 
Signed-off-by: Trond Myklebust 
Tested-by: Chris Perl 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Prevent kernel stack corruption on long values of flush

2012-10-28T17:02:11+00:00

commit 212ba90696ab4884e2025b0b13726d67aadc2cd4 upstream.

The buffer size in read_flush() is too small for the longest possible values
for it. This can lead to a kernel stack corruption:

[   43.047329] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff833e64b4
[   43.047329]
[   43.049030] Pid: 6015, comm: trinity-child18 Tainted: G        W    3.5.0-rc7-next-20120716-sasha #221
[   43.050038] Call Trace:
[   43.050435]  [] panic+0xcd/0x1f4
[   43.050931]  [] ? read_flush.isra.7+0xe4/0x100
[   43.051602]  [] __stack_chk_fail+0x16/0x20
[   43.052206]  [] read_flush.isra.7+0xe4/0x100
[   43.052951]  [] ? read_flush_pipefs+0x30/0x30
[   43.053594]  [] read_flush_procfs+0x2c/0x30
[   43.053596]  [] proc_reg_read+0x9c/0xd0
[   43.053596]  [] ? proc_reg_write+0xd0/0xd0
[   43.053596]  [] do_loop_readv_writev+0x4b/0x90
[   43.053596]  [] do_readv_writev+0xf6/0x1d0
[   43.053596]  [] vfs_readv+0x3e/0x60
[   43.053596]  [] sys_readv+0x48/0xb0
[   43.053596]  [] system_call_fastpath+0x1a/0x1f

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

SUNRPC: Ensure that the TCP socket is closed when in CLOSE_WAIT

2012-10-21T16:17:10+00:00

commit a519fc7a70d1a918574bb826cc6905b87b482eb9 upstream.

Instead of doing a shutdown() call, we need to do an actual close().
Ditto if/when the server is sending us junk RPC headers.

Signed-off-by: Trond Myklebust 
Tested-by: Simon Kirby 
Signed-off-by: Greg Kroah-Hartman

svcrpc: sends on closed socket should stop immediately

2012-09-14T17:00:39+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

2012-09-14T17:00:39+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

2012-09-14T17:00:38+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