Fix corrupted l2_asize in arcstats

Commit e0b0ca9 accidentally corrupted the l2_asize displayed in
arcstats.  This was caused by changing the l2arc_buf_hdr.b_asize
member from an int to uint32_t type.  There are places in the
code where this field is cast to a uint64_t resulting in the
b_hits member being treated as part of b_asize.

To resolve the issue the type has been changed to a uint64_t,
and the b_hits member is placed after the enum to prevent the
size of the structure from increasing.

This is a good example of exactly why it's a bad idea to use
ambiguous types (int) in these structures.

Signed-off-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1990
Add systemd unit files for ZFS startup

This adds systemd unit files replacing the functionality offered by
the SysV init script found in etc/init.d.

It has been developed and tested on Fedora 19, Fedora 20
and openSuSE 13.1.

Four unit files and one target are offered.

zfs-import-cache.service:
    Import pools from /etc/zfs/zpool.cache. This unit will wait for
    udev to settle.
zfs-import-scan.service:
    Import pools by scanning /dev/disk/by-id for zvols. This unit will
    only run if /etc/zfs/zpool.cache is not present. This unit will wait
    for udev to settle
zfs-mount.service:
    Mount ZFS native filesystems. It contains a dependency to be loaded
    before local-fs.target.
zfs-share.service:
    Share NFS/SMB filesystems. This unit contains a dependency that
    will cause it to be restarted whenever the smb or nfs-server unit
    is restarted, restoring the shares added.
zfs.target:
    This target pulls in the other units in order to start ZFS. It's
    the only unit that can be enabled/disabled, all other services
    are static and pulled in by dependencies. It will honour zfs=off
    and zfs=no options on the kernel command line.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2108
Accept user specified spl and kernel source dir.
Fix corrupted l2_asize in arcstats

Commit e0b0ca9 accidentally corrupted the l2_asize displayed in
arcstats.  This was caused by changing the l2arc_buf_hdr.b_asize
member from an int to uint32_t type.  There are places in the
code where this field is cast to a uint64_t resulting in the
b_hits member being treated as part of b_asize.

To resolve the issue the type has been changed to a uint64_t,
and the b_hits member is placed after the enum to prevent the
size of the structure from increasing.

This is a good example of exactly why it's a bad idea to use
ambiguous types (int) in these structures.

Signed-off-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1990
Add systemd unit files for ZFS startup

This adds systemd unit files replacing the functionality offered by
the SysV init script found in etc/init.d.

It has been developed and tested on Fedora 19, Fedora 20
and openSuSE 13.1.

Four unit files and one target are offered.

zfs-import-cache.service:
    Import pools from /etc/zfs/zpool.cache. This unit will wait for
    udev to settle.
zfs-import-scan.service:
    Import pools by scanning /dev/disk/by-id for zvols. This unit will
    only run if /etc/zfs/zpool.cache is not present. This unit will wait
    for udev to settle
zfs-mount.service:
    Mount ZFS native filesystems. It contains a dependency to be loaded
    before local-fs.target.
zfs-share.service:
    Share NFS/SMB filesystems. This unit contains a dependency that
    will cause it to be restarted whenever the smb or nfs-server unit
    is restarted, restoring the shares added.
zfs.target:
    This target pulls in the other units in order to start ZFS. It's
    the only unit that can be enabled/disabled, all other services
    are static and pulled in by dependencies. It will honour zfs=off
    and zfs=no options on the kernel command line.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2108
Merge branch 'master' of git://github.com/zfsonlinux/zfs
Initramfs scripts for ZoL.
* Put in /usr/share/initramfs-tools/ or /etc/initramfs-tools/.
* With pull request #1476 (not yet merged) comes a verbose warning
  if /usr/bin/net doesn't exist or isn't executable. Just create
  a dummy...
* If user haven't specified pool, but bootfs then use the first part
  of the bootfs path as pool name.
* Add support for booting of a ZFS snapshot.
  Do this by cloning the snapshot into a dataset. If this the resulting
  dataset already exists, destroy it. Then set mountpoint=/ on that
  dataset and mount it on root.