Commit c48a11c7ad26 ("netvm: propagate page->pfmemalloc to skb") added
checks for page->pfmemalloc to __skb_fill_page_desc():

        if (page->pfmemalloc && !page->mapping)
                skb->pfmemalloc = true;

It assumes page->mapping == NULL implies that page->pfmemalloc can be
trusted.  However, __delete_from_page_cache() can set set page->mapping
to NULL and leave page->index value alone.  Due to being in union, a
non-zero page->index will be interpreted as true page->pfmemalloc.

So the assumption is invalid if the networking code can see such a page.
And it seems it can.  We have encountered this with a NFS over loopback
setup when such a page is attached to a new skbuf.  There is no copying
going on in this case so the page confuses __skb_fill_page_desc which
interprets the index as pfmemalloc flag and the network stack drops
packets that have been allocated using the reserves unless they are to
be queued on sockets handling the swapping which is the case here and
that leads to hangs when the nfs client waits for a response from the
server which has been dropped and thus never arrive.

The struct page is already heavily packed so rather than finding another
hole to put it in, let's do a trick instead.  We can reuse the index
again but define it to an impossible value (-1UL).  This is the page
index so it should never see the value that large.  Replace all direct
users of page->pfmemalloc by page_is_pfmemalloc which will hide this
nastiness from unspoiled eyes.

The information will get lost if somebody wants to use page->index
obviously but that was the case before and the original code expected
that the information should be persisted somewhere else if that is
really needed (e.g.  what SLAB and SLUB do).

[akpm@linux-foundation.org: fix blooper in slub]
Fixes: c48a11c7ad26 ("netvm: propagate page->pfmemalloc to skb")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Debugged-by: Vlastimil Babka <vbabka@suse.com>
Debugged-by: Jiri Bohac <jbohac@suse.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: <stable@vger.kernel.org>	[3.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Bump version of igb to igb-5.2.18

Signed-off-by: Todd Fujinaka <todd.fujinaka@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Disable IPv6 extension header processing as per hardware errata.

Also fix copyright date.

Signed-off-by: Todd Fujinaka <todd.fujinaka@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

When programming the start of a periodic output, the code wrongly places
the seconds value into the "low" register and the nanoseconds into the
"high" register.  Even though this is backwards, it slipped through my
testing, because the re-arming code in the interrupt service routine is
correct, and the signal does appear starting with the second edge.

This patch fixes the issue by programming the registers correctly.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Four minor merge conflicts:

1) qca_spi.c renamed the local variable used for the SPI device
   from spi_device to spi, meanwhile the spi_set_drvdata() call
   got moved further up in the probe function.

2) Two changes were both adding new members to codel params
   structure, and thus we had overlapping changes to the
   initializer function.

3) 'net' was making a fix to sk_release_kernel() which is
   completely removed in 'net-next'.

4) In net_namespace.c, the rtnl_net_fill() call for GET operations
   had the command value fixed, meanwhile 'net-next' adjusted the
   argument signature a bit.

This also matches example merge resolutions posted by Stephen
Rothwell over the past two days.

Signed-off-by: David S. Miller <davem@davemloft.net>

This change updates igb so that it will correctly perform the descriptor
count calculation.  Previously it was taking NETDEV_FRAG_PAGE_MAX_SIZE
into account with isn't really correct since a different value is used to
determine the size of the pages used for TCP.  That is actually determined
by SKB_FRAG_PAGE_ORDER.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

adapter->tx_ring is set to NULL where rx_ring should be.

Fixes: 5536d2102a2d ("igb: Combine q_vector and ring allocation into a single function")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

When changing the number of rings by ethtool -L, q_vectors are reused,
which causes oops because of uninitialized pointers.

- When an rx is reused as a tx, q_vector->rx.ring is not set to NULL, which
  misleads igb_poll() to determine that it has an rx ring although it
  actually points to the tx ring.
- When a tx is reused as an rx, q_vector->rx.ring->skb
  (q_vector->ring[0].skb) has a value that was used as tx_stats before.

Fix these problems by zeroing it out on reuseing it.

Fixes: 02ef6e1d0b00 ("igb: Fix queue allocation method to accommodate changing during runtime")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

igb_enable_mas() should only be called for the 82575 and has no clear
return so changing it to void. Also simplify the odd conditional
expression.

Signed-off-by: Todd Fujinaka <todd.fujinaka@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>