Cast 'zfs bad bloc' to ULL for x86

Explicitly case this value to an unsigned long long for 32-bit
systems to inform the compiler that a long type should not be
used.  Otherwise we get the following compiler error:

  dmu_send.c:376: error: integer constant is too large for
  ‘long’ type

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fix function relocations in libzpool

binutils 2.23.1 fails in situations that generate function relocations
on PowerPC and possibly other architectures. This causes linking of
libzpool to fail because it depends on libnvpair. We add a dependency on
libnvpair to lib/libzpool/Makefile.am to correct that.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1267
Remove unused machelf.h header

The machelf.h header is never included by anything in the zfs
build process.  It is all effectively dead code which can be
safely removed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1265
Switch KM_SLEEP to KM_PUSHPAGE

Two more locations where KM_SLEEP was used in a call which must
use KM_PUSHPAGE were found while using the zpool upgrade command.
See commit b8d06fc for additional details.

Also make a small correction to the comment block above
dsl_dir_open_spa().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1268
Update the zfs.8 "ZFS Volumes as Swap" section

As of 0.6.0-rc11 using ZFS volumes as Linux swap devices is
supported.  Swapping to files in ZFS filesystems is not.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1189
Add explicit MAXNAMELEN check

It turns out that the Linux VFS doesn't strictly handle all cases
where a component path name exceeds MAXNAMELEN.  It does however
appear to correctly handle MAXPATHLEN for us.

The right way to handle this appears to be to add an explicit
check to the zpl_lookup() function.  Several in-tree filesystems
handle this case the same way.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1279
Make spa.c assertions catch unsupported pre-feature flag pool versions

A couple of assertions in spa.c were designed to prevent the use of
invalid pool versions. They were written under the assumption
that all valid pools are less than SPA_VERSION. Since feature flags
jumped from 28 to 5000, any numbers in the range 28 to 5000
non-inclusive will fail to trigger them.  We switch to the new
SPA_VERSION_IS_SUPPORTED macro to correct this.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1282
Fix broken RPATH in spec file

Rather then setting _prefix=/ and having to override all the
default install locations.  It's cleaner, and more understandable,
to leave prefix=/usr and only override _sbindir and _libdir.  This
fixes three issues:

* The commands no longer get built with an incorrect rpath for
  the libraries.   This is good because fixing this sort of
  thing is required by the Fedora packaging guidelines.

    http://fedoraproject.org/wiki/Packaging:Guidelines#Beware_of_Rpath

* The various AUTHORS, COPYRIGHT, etc files are now correctly
  installed under /usr/share/doc instead of /share/doc.

* _libexecdir is now handled properly for each distribution.
  Fedora/RHEL=/usr/libexec, OpenSUSE/SLES=/usr/lib, Debian=/usr/lib/rpm

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1058
Enable zfs_arc_memory_throttle_disable by default

The zfs_arc_memory_throttle_disable module option was introduced
by commit 0c5493d47059f25ce9dbf20c9fe87655f55102a1 to resolve a
memory miscalculation which could result in the txg_sync thread
spinning.

When this was first introduced the default behavior was left
unchanged until enough real world usage confirmed there were no
unexpected issues.  We've now reached that point.  Linux's
direct reclaim is working as expected so we're enabling this
behavior by default.

This helps pave the way to retire the spl_kmem_availrmem()
functionality in the SPL layer.  This was the only caller.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #938