Update utsname support

Modify the code to use the utsname() kernel function rather than
a global variable.  This results is cleaner more portable code
because utsname() is already provided by the kernel and can be
easily emulated in user space via uname(2).  This means that it
will behave consistently in both contexts.

This is also has the benefit that it allows the removal of a few
_KERNEL pre-processor conditions.  And it also is a pre-requisite
for a proper FUSE port because we need to provide a valid utsname.

Finally, it allows us to remove this functionality from the SPL
and all the related compatibility code.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2757

include/linux/Makefile.am

@@ -4,7 +4,8 @@ KERNEL_H = \
 	$(top_srcdir)/include/linux/dcache_compat.h \
 	$(top_srcdir)/include/linux/xattr_compat.h \
 	$(top_srcdir)/include/linux/vfs_compat.h \
-	$(top_srcdir)/include/linux/blkdev_compat.h
+	$(top_srcdir)/include/linux/blkdev_compat.h \
+	$(top_srcdir)/include/linux/utsname_compat.h
 
 USER_H =
 

include/linux/utsname_compat.h

@@ -2,33 +2,28 @@
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
- * Common Development and Distribution License, Version 1.0 only
- * (the "License").  You may not use this file except in compliance
- * with the License.
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
  *
- * You can obtain a copy of the license at usr/src/OPENLIBSPLARIS.LICENSE
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
  * See the License for the specific language governing permissions
  * and limitations under the License.
  *
  * When distributing Covered Code, include this CDDL HEADER in each
- * file and include the License file at usr/src/OPENLIBSPLARIS.LICENSE.
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  * If applicable, add the following below this CDDL HEADER, with the
  * fields enclosed by brackets "[]" replaced with your own identifying
  * information: Portions Copyright [yyyy] [name of copyright owner]
  *
  * CDDL HEADER END
  */
-/*
- * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
- */
 
-#ifndef _LIBSPL_UTSNAME_H
-#define	_LIBSPL_UTSNAME_H
+#ifndef	_ZFS_UTSNAME_H
+#define	_ZFS_UTSNAME_H
 
-#include_next <sys/utsname.h>
+#include <linux/utsname.h>
 
-struct utsname utsname;
+typedef struct new_utsname	utsname_t;
 
-#endif  /* _LIBSPL_UTSNAME_H */
+#endif	/* _ZFS_UTSNAME_H */

include/sys/zfs_context.h

@@ -67,6 +67,7 @@
 #include <sys/ctype.h>
 #include <sys/disp.h>
 #include <linux/dcache_compat.h>
+#include <linux/utsname_compat.h>
 
 #else /* _KERNEL */
 
@@ -117,6 +118,7 @@
 #include <sys/fm/fs/zfs.h>
 #include <sys/sunddi.h>
 #include <sys/debug.h>
+#include <sys/utsname.h>
 
 /*
  * Stack
@@ -673,6 +675,9 @@ extern int ddi_strtoul(const char *str, char **nptr, int base,
 extern int ddi_strtoull(const char *str, char **nptr, int base,
     u_longlong_t *result);
 
+typedef struct utsname	utsname_t;
+extern utsname_t *utsname(void);
+
 /* ZFS Boot Related stuff. */
 
 struct _buf {

lib/libspl/include/sys/Makefile.am

@@ -47,7 +47,6 @@ libspl_HEADERS = \
 	$(top_srcdir)/lib/libspl/include/sys/types.h \
 	$(top_srcdir)/lib/libspl/include/sys/tzfile.h \
 	$(top_srcdir)/lib/libspl/include/sys/uio.h \
-	$(top_srcdir)/lib/libspl/include/sys/utsname.h \
 	$(top_srcdir)/lib/libspl/include/sys/va_list.h \
 	$(top_srcdir)/lib/libspl/include/sys/varargs.h \
 	$(top_srcdir)/lib/libspl/include/sys/vnode.h \

lib/libzpool/kernel.c

@@ -47,10 +47,7 @@ int aok;
 uint64_t physmem;
 vnode_t *rootdir = (vnode_t *)0xabcd1234;
 char hw_serial[HW_HOSTID_LEN];
-
-struct utsname utsname = {
-	"userland", "libzpool", "1", "1", "na"
-};
+struct utsname hw_utsname;
 
 /* this only exists to have its address taken */
 struct proc p0;
@@ -1089,6 +1086,12 @@ ddi_strtoull(const char *str, char **nptr, int base, u_longlong_t *result)
 	return (0);
 }
 
+utsname_t *
+utsname(void)
+{
+	return (&hw_utsname);
+}
+
 /*
  * =========================================================================
  * kernel emulation setup & teardown
@@ -1121,6 +1124,7 @@ kernel_init(int mode)
 
 	VERIFY((random_fd = open("/dev/random", O_RDONLY)) != -1);
 	VERIFY((urandom_fd = open("/dev/urandom", O_RDONLY)) != -1);
+	VERIFY0(uname(&hw_utsname));
 
 	thread_init();
 	system_taskq_init();

module/zfs/spa_config.c

@@ -32,7 +32,6 @@
 #include <sys/fs/zfs.h>
 #include <sys/vdev_impl.h>
 #include <sys/zfs_ioctl.h>
-#include <sys/utsname.h>
 #include <sys/systeminfo.h>
 #include <sys/sunddi.h>
 #include <sys/zfeature.h>
@@ -408,8 +407,8 @@ spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
 		    hostid) == 0);
 	}
-	VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
-	    utsname.nodename) == 0);
+	VERIFY0(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
+	    utsname()->nodename));
 
 	if (vd != rvd) {
 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,

module/zfs/spa_history.c

@@ -32,7 +32,6 @@
 #include <sys/dmu_objset.h>
 #include <sys/dsl_dataset.h>
 #include <sys/dsl_dir.h>
-#include <sys/utsname.h>
 #include <sys/cmn_err.h>
 #include <sys/sunddi.h>
 #include <sys/cred.h>
@@ -236,9 +235,8 @@ spa_history_log_sync(void *arg, dmu_tx_t *tx)
 #endif
 
 	fnvlist_add_uint64(nvl, ZPOOL_HIST_TIME, gethrestime_sec());
-#ifdef _KERNEL
-	fnvlist_add_string(nvl, ZPOOL_HIST_HOST, utsname.nodename);
-#endif
+	fnvlist_add_string(nvl, ZPOOL_HIST_HOST, utsname()->nodename);
+
 	if (nvlist_exists(nvl, ZPOOL_HIST_CMD)) {
 		zfs_dbgmsg("command: %s",
 		    fnvlist_lookup_string(nvl, ZPOOL_HIST_CMD));
@@ -546,11 +544,12 @@ spa_history_log_internal_dd(dsl_dir_t *dd, const char *operation,
 void
 spa_history_log_version(spa_t *spa, const char *operation)
 {
+	utsname_t *u = utsname();
+
 	spa_history_log_internal(spa, operation, NULL,
 	    "pool version %llu; software version %llu/%d; uts %s %s %s %s",
 	    (u_longlong_t)spa_version(spa), SPA_VERSION, ZPL_VERSION,
-	    utsname.nodename, utsname.release, utsname.version,
-	    utsname.machine);
+	    u->nodename, u->release, u->version, u->machine);
 }
 
 #if defined(_KERNEL) && defined(HAVE_SPL)