Update build system and packaging

Minimal changes required to integrate the SPL sources in to the
ZFS repository build infrastructure and packaging.

Build system and packaging:
  * Renamed SPL_* autoconf m4 macros to ZFS_*.
  * Removed redundant SPL_* autoconf m4 macros.
  * Updated the RPM spec files to remove SPL package dependency.
  * The zfs package obsoletes the spl package, and the zfs-kmod
    package obsoletes the spl-kmod package.
  * The zfs-kmod-devel* packages were updated to add compatibility
    symlinks under /usr/src/spl-x.y.z until all dependent packages
    can be updated.  They will be removed in a future release.
  * Updated copy-builtin script for in-kernel builds.
  * Updated DKMS package to include the spl.ko.
  * Updated stale AUTHORS file to include all contributors.
  * Updated stale COPYRIGHT and included the SPL as an exception.
  * Renamed README.markdown to README.md
  * Renamed OPENSOLARIS.LICENSE to LICENSE.
  * Renamed DISCLAIMER to NOTICE.

Required code changes:
  * Removed redundant HAVE_SPL macro.
  * Removed _BOOT from nvpairs since it doesn't apply for Linux.
  * Initial header cleanup (removal of empty headers, refactoring).
  * Remove SPL repository clone/build from zimport.sh.
  * Use of DEFINE_RATELIMIT_STATE and DEFINE_SPINLOCK removed due
    to build issues when forcing C99 compilation.
  * Replaced legacy ACCESS_ONCE with READ_ONCE.
  * Include needed headers for `current` and `EXPORT_SYMBOL`.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
TEST_ZIMPORT_SKIP="yes"
Closes #7556

module/zcommon/zfeature_common.c

@@ -26,9 +26,7 @@
  * Copyright (c) 2014, Nexenta Systems, Inc. All rights reserved.
  */
 
-#ifdef _KERNEL
-#include <sys/systm.h>
-#else
+#ifndef _KERNEL
 #include <errno.h>
 #include <string.h>
 #endif
@@ -351,7 +349,7 @@ zpool_feature_init(void)
 	}
 }
 
-#if defined(_KERNEL) && defined(HAVE_SPL)
+#if defined(_KERNEL)
 EXPORT_SYMBOL(zfeature_lookup_name);
 EXPORT_SYMBOL(zfeature_is_supported);
 EXPORT_SYMBOL(zfeature_is_valid_guid);

module/zcommon/zfs_comutil.c

@@ -29,15 +29,12 @@
  * then a separate file should to be created.
  */
 
-#if defined(_KERNEL)
-#include <sys/systm.h>
-#else
+#if !defined(_KERNEL)
 #include <string.h>
 #endif
 
 #include <sys/types.h>
 #include <sys/fs/zfs.h>
-#include <sys/int_limits.h>
 #include <sys/nvpair.h>
 #include "zfs_comutil.h"
 #include <sys/zfs_ratelimit.h>
@@ -207,7 +204,7 @@ const char *zfs_history_event_names[ZFS_NUM_LEGACY_HISTORY_EVENTS] = {
 	"pool split",
 };
 
-#if defined(_KERNEL) && defined(HAVE_SPL)
+#if defined(_KERNEL)
 EXPORT_SYMBOL(zfs_allocatable_devs);
 EXPORT_SYMBOL(zpool_get_rewind_policy);
 EXPORT_SYMBOL(zfs_zpl_version_map);

module/zcommon/zfs_deleg.c

@@ -28,16 +28,15 @@
 #include <sys/zfs_context.h>
 
 #if defined(_KERNEL)
-#include <sys/systm.h>
 #include <sys/sunddi.h>
 #include <sys/ctype.h>
 #else
 #include <stdio.h>
 #include <unistd.h>
-#include <strings.h>
 #include <libnvpair.h>
 #include <ctype.h>
 #endif
+#include <sys/strings.h>
 #include <sys/dsl_deleg.h>
 #include "zfs_prop.h"
 #include "zfs_deleg.h"
@@ -244,7 +243,7 @@ zfs_deleg_whokey(char *attr, zfs_deleg_who_type_t type,
 	}
 }
 
-#if defined(_KERNEL) && defined(HAVE_SPL)
+#if defined(_KERNEL)
 EXPORT_SYMBOL(zfs_deleg_verify_nvlist);
 EXPORT_SYMBOL(zfs_deleg_whokey);
 EXPORT_SYMBOL(zfs_deleg_canonicalize_perm);

module/zcommon/zfs_fletcher.c

@@ -867,7 +867,7 @@ zio_abd_checksum_func_t fletcher_4_abd_ops = {
 };
 
 
-#if defined(_KERNEL) && defined(HAVE_SPL)
+#if defined(_KERNEL)
 #include <linux/mod_compat.h>
 
 static int

module/zcommon/zfs_fletcher_aarch64_neon.c

@@ -45,8 +45,8 @@
 
 #include <linux/simd_aarch64.h>
 #include <sys/spa_checksum.h>
+#include <sys/strings.h>
 #include <zfs_fletcher.h>
-#include <strings.h>
 
 static void
 fletcher_4_aarch64_neon_init(fletcher_4_ctx_t *ctx)

module/zcommon/zfs_fletcher_avx512.c

@@ -28,8 +28,8 @@
 #include <sys/byteorder.h>
 #include <sys/frame.h>
 #include <sys/spa_checksum.h>
+#include <sys/strings.h>
 #include <zfs_fletcher.h>
-#include <strings.h>
 
 #define	__asm __asm__ __volatile__
 

module/zcommon/zfs_fletcher_intel.c

@@ -44,8 +44,8 @@
 
 #include <linux/simd_x86.h>
 #include <sys/spa_checksum.h>
+#include <sys/strings.h>
 #include <zfs_fletcher.h>
-#include <strings.h>
 
 static void
 fletcher_4_avx2_init(fletcher_4_ctx_t *ctx)

module/zcommon/zfs_fletcher_sse.c

@@ -46,8 +46,8 @@
 #include <linux/simd_x86.h>
 #include <sys/spa_checksum.h>
 #include <sys/byteorder.h>
+#include <sys/strings.h>
 #include <zfs_fletcher.h>
-#include <strings.h>
 
 static void
 fletcher_4_sse2_init(fletcher_4_ctx_t *ctx)

module/zcommon/zfs_fletcher_superscalar.c

@@ -43,8 +43,8 @@
 
 #include <sys/byteorder.h>
 #include <sys/spa_checksum.h>
+#include <sys/strings.h>
 #include <zfs_fletcher.h>
-#include <strings.h>
 
 static void
 fletcher_4_superscalar_init(fletcher_4_ctx_t *ctx)

module/zcommon/zfs_fletcher_superscalar4.c

@@ -43,8 +43,8 @@
 
 #include <sys/byteorder.h>
 #include <sys/spa_checksum.h>
+#include <sys/strings.h>
 #include <zfs_fletcher.h>
-#include <strings.h>
 
 static void
 fletcher_4_superscalar4_init(fletcher_4_ctx_t *ctx)

module/zcommon/zfs_namecheck.c

@@ -38,9 +38,7 @@
  * Each function returns 0 on success, -1 on error.
  */
 
-#if defined(_KERNEL)
-#include <sys/systm.h>
-#else
+#if !defined(_KERNEL)
 #include <string.h>
 #endif
 
@@ -349,7 +347,7 @@ pool_namecheck(const char *pool, namecheck_err_t *why, char *what)
 	return (0);
 }
 
-#if defined(_KERNEL) && defined(HAVE_SPL)
+#if defined(_KERNEL)
 EXPORT_SYMBOL(pool_namecheck);
 EXPORT_SYMBOL(dataset_namecheck);
 EXPORT_SYMBOL(zfs_component_namecheck);

module/zcommon/zfs_prop.c

@@ -39,9 +39,7 @@
 #include "zfs_deleg.h"
 #include "zfs_fletcher.h"
 
-#if defined(_KERNEL)
-#include <sys/systm.h>
-#else
+#if !defined(_KERNEL)
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
@@ -847,7 +845,7 @@ zfs_prop_align_right(zfs_prop_t prop)
 
 #endif
 
-#if defined(_KERNEL) && defined(HAVE_SPL)
+#if defined(_KERNEL)
 static int __init
 zcommon_init(void)
 {

module/zcommon/zfs_uio.c

@@ -49,6 +49,8 @@
 
 #include <sys/types.h>
 #include <sys/uio_impl.h>
+#include <sys/sysmacros.h>
+#include <sys/strings.h>
 #include <linux/kmap_compat.h>
 
 /*

module/zcommon/zpool_prop.c

@@ -32,9 +32,7 @@
 
 #include "zfs_prop.h"
 
-#if defined(_KERNEL)
-#include <sys/systm.h>
-#else
+#if !defined(_KERNEL)
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
@@ -244,7 +242,7 @@ zpool_prop_align_right(zpool_prop_t prop)
 }
 #endif
 
-#if defined(_KERNEL) && defined(HAVE_SPL)
+#if defined(_KERNEL)
 /* zpool property functions */
 EXPORT_SYMBOL(zpool_prop_init);
 EXPORT_SYMBOL(zpool_prop_get_type);

module/zcommon/zprop_common.c

@@ -41,8 +41,9 @@
 #include "zfs_deleg.h"
 
 #if defined(_KERNEL)
-#include <sys/systm.h>
-#include <util/qsort.h>
+#include <linux/sort.h>
+#define	qsort(base, num, size, cmp) \
+    sort(base, num, size, cmp, NULL)
 #else
 #include <stdlib.h>
 #include <string.h>
@@ -435,7 +436,7 @@ zprop_width(int prop, boolean_t *fixed, zfs_type_t type)
 
 #endif
 
-#if defined(_KERNEL) && defined(HAVE_SPL)
+#if defined(_KERNEL)
 /* Common routines to initialize property tables */
 EXPORT_SYMBOL(zprop_register_impl);
 EXPORT_SYMBOL(zprop_register_string);