A long time ago we had bugs, primarily in TCP, where we would modify
skb->truesize (for TSO queue collapsing) in ways which would corrupt
the socket memory accounting.

skb_truesize_check() was added in order to try and catch this error
more systematically.

However this debugging check has morphed into a Frankenstein of sorts
and these days it does nothing other than catch false-positives.

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

The overlap with the old SO_TIMESTAMP[NS] options is handled so
that time stamping in software (net_enable_timestamp()) is
enabled when SO_TIMESTAMP[NS] and/or SO_TIMESTAMPING_RX_SOFTWARE
is set.  It's disabled if all of these are off.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Conflicts:
	drivers/net/wireless/iwlwifi/iwl-agn.c
	drivers/net/wireless/iwlwifi/iwl3945-base.c

The problem is that in_atomic() will return false inside spinlocks if
CONFIG_PREEMPT=n.  This will lead to deadlockable GFP_KERNEL allocations
from spinlocked regions.

Secondly, if CONFIG_PREEMPT=y, this bug solves itself because networking
will instead use GFP_ATOMIC from this callsite.  Hence we won't get the
might_sleep() debugging warnings which would have informed us of the buggy
callsites.

Solve both these problems by switching to in_interrupt().  Now, if someone
runs a gfp_any() allocation from inside spinlock we will get the warning
if CONFIG_PREEMPT=y.

I reviewed all callsites and most of them were too complex for my little
brain and none of them documented their interface requirements.  I have no
idea what this patch will do.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The function sock_alloc_send_pskb is completely useless if not
exported since most of the code in it won't be used as is.  In
fact, this code has already been duplicated in the tun driver.

Now that we need accounting in the tun driver, we can in fact
use this function as is.  So this patch marks it for export again.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using one atomic_t per protocol, use a percpu_counter
for "orphan_count", to reduce cache line contention on
heavy duty network servers. 

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using one atomic_t per protocol, use a percpu_counter
for "sockets_allocated", to reduce cache line contention on
heavy duty network servers. 

Note : We revert commit (248969ae31e1b3276fc4399d67ce29a5d81e6fd9
net: af_unix can make unix_nr_socks visbile in /proc),
since it is not anymore used after sock_prot_inuse_add() addition

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Conflicts:

	drivers/isdn/i4l/isdn_net.c
	fs/cifs/connect.c

This is a straightforward patch, using hlist_nulls infrastructure.

RCUification already done on UDP two weeks ago.

Using hlist_nulls permits us to avoid some memory barriers, both
at lookup time and delete time.

Patch is large because it adds new macros to include/net/sock.h.
These macros will be used by TCP & DCCP in next patch.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>