Define the needed ISA types for Sparc

Add the minimum required ISA types to support the Sparc
architecture.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: marku89 <mar42@kola.li>
Issue #1700
Use local variable to read zp->z_mode

When accessing the zp->z_mode through the SA bulk interface we
expect that 64-bits are available to hold the result.  However,
on 32-bit platforms mode_t will only be 32-bits so we cannot
pass it to SA_ADD_BULK_ATTR().  Instead a local uint64_t variable
must be used and the result assigned to zp->z_mode.

This went unnoticed on 32-bit little endian platforms because
the bytes happen to end up in the correct 32-bits.  But on big
endian platforms like Sparc the zp->z_mode will always end up
set to zero.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: marku89 <mar42@kola.li>
Issue #1700
Fix nvlist 'Bus Error' for Sparc

The mis-aligned memory accesses in nvpair_native_embedded() and
nvpair_native_embedded_array() will cause a 'Bus Error' for
architectures such as Sparc which not fully byte addressible.
To avoid this issue care is taken to avoid dereferencing the
potentially mis-aligned packed nvlist_t.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: marku89 <mar42@kola.li>
Issue #1700
Fix zfs_getattr_fast types

On Sparc sp->blksize will be a 64-bit value which is then cast
incorrectly to a 32-bit value.  For big endian systems this
results in an incorrect value for sp->blksize.  To resolve the
problem local variables of the correct size are used and then
assigned to sp->blksize.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: marku89 <mar42@kola.li>
Issue #1700
Force LZ4_FORCE_SW_BITCOUNT for Sparc

This change was proposed for Sparc but it's not clear to me
why it's required.  Proper support exists in the lz4 code to
detect the endianness and the required builtins are available
for gcc.  Still I'm including the patch because it will only
impact Sparc and it may resolve a case which hasn't occured
to me.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: marku89 <mar42@kola.li>
Issue #1700
Drain iput taskq outside z_teardown_lock

It's unsafe to drain the iput taskq while holding the z_teardown_lock
as a writer.  This is because when the last reference on an inode is
dropped it may still have pages which need to be written to disk.
This will be done through zpl_writepages which will acquire the
z_teardown_lock as a reader in ZFS_ENTER.  Therefore, if we're
holding the lock as a writer in zfs_sb_teardown the unmount will
deadlock.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Closes #1988