linux-toradex.git/net/sunrpc, branch v3.0.41

SUNRPC: return negative value in case rpcbind client creation error

2012-08-15T19:04:09+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

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

2012-08-09T15:27:51+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

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

2012-06-22T18:34:13+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

nfsd: don't allow zero length strings in cache_parse()

2012-04-02T16:27:21+00:00

commit 6d8d17499810479eabd10731179c04b2ca22152f upstream.

There is no point in passing a zero length string here and quite a
few of that cache_parse() implementations will Oops if count is
zero.

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

SUNRPC: We must not use list_for_each_entry_safe() in rpc_wake_up()

2012-04-02T16:27:17+00:00

commit 540a0f7584169651f485e8ab67461fcb06934e38 upstream.

The problem is that for the case of priority queues, we
have to assume that __rpc_remove_wait_queue_priority will move new
elements from the tk_wait.links lists into the queue->tasks[] list.
We therefore cannot use list_for_each_entry_safe() on queue->tasks[],
since that will skip these new tasks that __rpc_remove_wait_queue_priority
is adding.

Without this fix, rpc_wake_up and rpc_wake_up_status will both fail
to wake up all functions on priority wait queues, which can result
in some nasty hangs.

Reported-by: Andy Adamson 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

svcrpc: avoid memory-corruption on pool shutdown

2012-01-26T01:24:48+00:00

commit b4f36f88b3ee7cf26bf0be84e6c7fc15f84dcb71 upstream.

Socket callbacks use svc_xprt_enqueue() to add an xprt to a
pool->sp_sockets list.  In normal operation a server thread will later
come along and take the xprt off that list.  On shutdown, after all the
threads have exited, we instead manually walk the sv_tempsocks and
sv_permsocks lists to find all the xprt's and delete them.

So the sp_sockets lists don't really matter any more.  As a result,
we've mostly just ignored them and hoped they would go away.

Which has gotten us into trouble; witness for example ebc63e531cc6
"svcrpc: fix list-corrupting race on nfsd shutdown", the result of Ben
Greear noticing that a still-running svc_xprt_enqueue() could re-add an
xprt to an sp_sockets list just before it was deleted.  The fix was to
remove it from the list at the end of svc_delete_xprt().  But that only
made corruption less likely--I can see nothing that prevents a
svc_xprt_enqueue() from adding another xprt to the list at the same
moment that we're removing this xprt from the list.  In fact, despite
the earlier xpo_detach(), I don't even see what guarantees that
svc_xprt_enqueue() couldn't still be running on this xprt.

So, instead, note that svc_xprt_enqueue() essentially does:
	lock sp_lock
		if XPT_BUSY unset
			add to sp_sockets
	unlock sp_lock

So, if we do:

	set XPT_BUSY on every xprt.
	Empty every sp_sockets list, under the sp_socks locks.

Then we're left knowing that the sp_sockets lists are all empty and will
stay that way, since any svc_xprt_enqueue() will check XPT_BUSY under
the sp_lock and see it set.

And *then* we can continue deleting the xprt's.

(Thanks to Jeff Layton for being correctly suspicious of this code....)

Cc: Ben Greear 
Cc: Jeff Layton 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

svcrpc: destroy server sockets all at once

2012-01-26T01:24:48+00:00

commit 2fefb8a09e7ed251ae8996e0c69066e74c5aa560 upstream.

There's no reason I can see that we need to call sv_shutdown between
closing the two lists of sockets.

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

svcrpc: fix double-free on shutdown of nfsd after changing pool mode

2012-01-26T01:24:47+00:00

commit 61c8504c428edcebf23b97775a129c5b393a302b upstream.

The pool_to and to_pool fields of the global svc_pool_map are freed on
shutdown, but are initialized in nfsd startup only in the
SVC_POOL_PERCPU and SVC_POOL_PERNODE cases.

They *are* initialized to zero on kernel startup.  So as long as you use
only SVC_POOL_GLOBAL (the default), this will never be a problem.

You're also OK if you only ever use SVC_POOL_PERCPU or SVC_POOL_PERNODE.

However, the following sequence events leads to a double-free:

	1. set SVC_POOL_PERCPU or SVC_POOL_PERNODE
	2. start nfsd: both fields are initialized.
	3. shutdown nfsd: both fields are freed.
	4. set SVC_POOL_GLOBAL
	5. start nfsd: the fields are left untouched.
	6. shutdown nfsd: now we try to free them again.

Step 4 is actually unnecessary, since (for some bizarre reason), nfsd
automatically resets the pool mode to SVC_POOL_GLOBAL on shutdown.

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

SUNRPC: Ensure we return EAGAIN in xs_nospace if congestion is cleared

2011-12-09T16:52:27+00:00

commit 24ca9a847791fd53d9b217330b15f3c285827a18 upstream.

By returning '0' instead of 'EAGAIN' when the tests in xs_nospace() fail
to find evidence of socket congestion, we are making the RPC engine believe
that the message was incorrectly sent and so it disconnects the socket
instead of just retrying.

The bug appears to have been introduced by commit
5e3771ce2d6a69e10fcc870cdf226d121d868491 (SUNRPC: Ensure that xs_nospace
return values are propagated).

Reported-by: Andrew Cooper 
Signed-off-by: Trond Myklebust 
Tested-by: Andrew Cooper 
Signed-off-by: Greg Kroah-Hartman

NFS/sunrpc: don't use a credential with extra groups.

2011-11-11T17:37:07+00:00

commit dc6f55e9f8dac4b6479be67c5c9128ad37bb491f upstream.

The sunrpc layer keeps a cache of recently used credentials and
'unx_match' is used to find the credential which matches the current
process.

However unx_match allows a match when the cached credential has extra
groups at the end of uc_gids list which are not in the process group list.

So if a process with a list of (say) 4 group accesses a file and gains
access because of the last group in the list, then another process
with the same uid and gid, and a gid list being the first tree of the
gids of the original process tries to access the file, it will be
granted access even though it shouldn't as the wrong rpc credential
will be used.

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