Support debug and debug-devel sub packages

This commit adds support for building debug and debug-devel sub packages
of the zfs-modules main package. This is to allow building packages
which are built against a debug kernel. By default, only packages are
built against a regular non-debug kernel. This can be toggled by passing
the '--with kernel-debug' parameter to rpmbuild.

Examples:

    # To build packages against only the non-debug kernel
    $ rpmbuild --rebuild --with kernel --without kernel-debug $SRPM

    # To build packages against only the debug kernel
    $ rpmbuild --rebuild --without kernel --with kernel-debug $SRPM

    # To build packages against debug and non-debug kernel
    $ rpmbuild --rebuild --with kernel --with kernel-debug $SRPM

Note: Only the RHEL 5/6, CHAOS 5, and Fedora distributions are supported
      for building the debug and debug-devel packages.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Remove Chaos 4.x RPM support

The Chaos 4.x distribution is based on RHEL 5.x which is no longer
supported by ZoL since it uses a 2.6.18 kernel.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Update incorrect ddt_zap_lookup() assertion

When the ddt_zap_lookup() function was updated to dynamically
allocate memory for the cbuf variable, to save stack space, the
'csize <= sizeof (cbuf)' assertion was not updated.  The result
of this was that the size of the pointer was being used in the
comparison rather than the buffer size.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Use ULL suffix in constants

The lack of the ULL suffix causes warnings such as the following on
32-bit systems:

  In function 'zfsctl_is_snapdir':
  zfs-0.6.0//module/zfs/zfs_ctldir.c:151: warning: integer constant
  is too large for 'long' type

We add the ULL suffix to fix that.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #813
Relicense zfs.gentoo.in from GPLv2 to 2-clause BSD

As the Gentoo sys-fs/zfs maintainer, I receive license compatibility
questions and at times, those questions can be harassing. I feel that
the presence of the GPL in Gentoo's package metadata promotes such
questions.  zfs.gentoo.in is the only GPLv2 licensed file in ZFS, so I
have taken the liberty of contacting all contributors to this file to
request permission to relicense it.

All of the contributors to this file have agreed to relicense it under
the 2-clause BSD license. I have added their Signed-offs to this commit,
in order of first contribution. Thank you everyone for being so
understanding.

Signed-off-by: devsk <devsku@gmail.com>
Signed-off-by: Alexey Shvetsov <alexxy@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrew Tselischev <andrewtselischev@gmail.com>
Signed-off-by: Zachary Bedell <zac@thebedells.org>
Signed-off-by: Gunnar Beutner <gunnar@beutner.name>
Signed-off-by: Kyle Fuller <inbox@kylefuller.co.uk>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Closes #819
Illumos #1748: desire support for reguid in zfs

Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Reviewed by: Alexander Eremin <alexander.eremin@nexenta.com>
Reviewed by: Alexander Stetsenko <ams@nexenta.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  https://www.illumos.org/issues/1748

This commit modifies the user to kernel space ioctl ABI.  Extra
care should be taken when updating to ensure both the kernel
modules and utilities are updated.  If only the user space
component is updated both the 'zpool events' command and the
'zpool reguid' command will not work until the kernel modules
are updated.

Ported by:     Martin Matuska <martin@matuska.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #665
Illumos #1949, #1953

1949 crash during reguid causes stale config
1953 allow and unallow missing from zpool history since removal of pyzfs

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Garrett D'Amore <garrett.damore@gmail.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Steve Gonczi <gonczi@comcast.net>
Approved by: Eric Schrock <eric.schrock@delphix.com>

References:
  https://www.illumos.org/issues/1949
  https://www.illumos.org/issues/1953

Ported by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #665
Fix error handling for "zpool online -e".

The error handling code around zpool_relabel_disk() is either inexistent
or wrong. The function call itself is not checked, and
zpool_relabel_disk() is generating error messages from an unitialized
buffer.

Before:

    # zpool online -e homez sdb; echo $?
    `: cannot relabel 'sdb1': unable to open device: 2
    0

After:

    # zpool online -e homez sdb; echo $?
    cannot expand sdb: cannot relabel 'sdb1': unable to open device: 2
    1

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #808
Use the right device path when relabeling.

Currently, zpool_vdev_online() calls zpool_relabel_disk() with a short
partition device name, which is obviously wrong because (1)
zpool_relabel_disk() expects a full, absolute path to use with open()
and (2) efi_write() must be called on an opened disk device, not a
partition device.

With this patch, zpool_relabel_disk() gets called with a full disk
device path. The path is determined using the same algorithm as
zpool_find_vdev().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #808
Fix efi_use_whole_disk() when efi_nparts == 128.

Commit e5dc681a changed EFI_NUMPAR from 9 to 128. This means that the
on-disk EFI label has efi_nparts = 128 instead of 9. The index of the
reserved partition, however, is still 8. This breaks
efi_use_whole_disk(), which uses efi_nparts-1 as the index of the
reserved partition.

This commit fixes efi_use_whole_disk() when the index of the reserved
partition is not efi_nparts-1. It rewrites the algorithm and makes it
more robust by using the order of the partitions instead of their
numbering. It assumes that the last non-empty partition is the reserved
partition, and that the non-empty partition before that is the data
partition.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #808
Add PowerPC to supported VTOCs

This code was was inherited from Solaris which was careful to define
the expected VTOC for various supported architectures.  While this
check may have made sense there it's something we should be able to
safely drop under Linux.

However, I'm not quite ready to do that yet.  So for the moment I'm
just doing the very safe thing of adding PowerPC as a supported type.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Move zfs.release generation to configure step

Previously, the zfs.release file was created at 'make install' time.
This is slightly problematic when the file is needed without running
'make install'. Because of this, the step creating the file was removed
from 'make install' and replaced with a more appropriate zfs.release.in
file.

As a result, the zfs.release file will now be created earlier as part
of the 'configure' step as opposed to the 'make install' step.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Move partition scanning from userspace to module.

Currently, zpool online -e (dynamic vdev expansion) doesn't work on
whole disks because we're invoking ioctl(BLKRRPART) from userspace
while ZFS still has a partition open on the disk, which results in
EBUSY.

This patch moves the BLKRRPART invocation from the zpool utility to the
module. Specifically, this is done just before opening the device in
vdev_disk_open() which is called inside vdev_reopen(). This requires
jumping through some hoops to get to the disk device from the partition
device, and to make sure we can still open the partition after the
BLKRRPART call.

Note that this new code path is triggered on dynamic vdev expansion
only; other actions, like creating a new pool, are unchanged and still
call BLKRRPART from userspace.

This change also depends on API changes which are available in 2.6.37
and latter kernels.  The build system has been updated to detect this,
but there is no compatibility mode for older kernels.  This means that
online expansion will NOT be available in older kernels.  However, it
will still be possible to expand the vdev offline.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #808
Fix build failures on PaX/GRSecurity patched kernels

Gentoo Hardened kernels include the PaX/GRSecurity patches. They use a
dialect of C that relies on a GCC plugin. In particular, struct
file_operations has been marked do_const in the PaX/GRSecurity dialect,
which causes GCC to consider all instances of it as const. This caused
failures in the autotools checks and the ZFS source code.

To address this, we modify the autotools checks to take into account
differences between the PaX C dialect and the regular C dialect. We also
modify struct zfs_acl's z_ops member to be a pointer to a function
pointer table. Lastly, we modify zpl_put_link() to address a PaX change
to the function prototype of nd_get_link().  This avoids compiler errors
in the PaX/GRSecurity dialect.

Note that the change in zpl_put_link() causes a warning that becomes a
build failure when debugging is enabled. Fixing that warning requires
ryao/spl@5ca50ef459c59bc74b7a7cd3af7311da2b1cd2c3.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #484
Add 'inline' keyword

The '__attribute__((always_inline))' does not strictly imply
'inline'.  Newer versions of gcc detect this misuse and issue
the following warning.  Including the missing 'inline' resolves
the build warning.

    ./module/zfs/dsl_scan.c:758:1:error: always_inline function
    might not be inlinable [-Werror=attributes]

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Add ddt_object_load() error handling

Add the missing error handling to ddt_object_load().  There's no
good reason this needs to be fatal.  It is preferable that an
error be returned.  This will allow 'zpool import -FX' to safely
attempt to rollback through previous txgs looking for a good one.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Disable .zfs directory on 32-bit systems

The .zfs control directory implementation currently relies on
the fact that there is a direct 1:1 mapping from an object id
to its inode number.  This works well as long as the system
uses a 64-bit value to store the inode number.

Unfortunately, the Linux kernel defines the inode number as
an 'unsigned long' type.  This means that for 32-bit systems
will only have 32-bit inode numbers but we still have 64-bit
object ids.

This problem is particularly acute for the .zfs directories
which leverage those upper 32-bits.  This is done to avoid
conflicting with object ids which are allocated monotonically
starting from 0.  This is likely to also be a problem for
datasets on 32-bit systems with more than ~2 billion files.

The right long term fix must remove the simple 1:1 mapping.
Until that's done the only safe thing to do is to disable the
.zfs directory on 32-bit systems.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fix NULL pointer dereference on PaX/GRSecurity patched Linux 3.3 and later kernels

Support for PaX/GRSecurity patched kernels was developed against Linux
3.2.  Unfortunately, an autotools check introduced for a Linux 3.3 API
fails on PaX/GRSecurity patched kernels. This causes the module to be
built against the Linux 3.2 ABI, which results in a NULL pointer
dereference at runtime.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Closes #794
Closes #809
Merge remote-tracking branch 'zfsonlinux/master'
Added a to-do item to the README