Add linux zpios support

Linux kernel implementation of PIOS test app.

Signed-off-by: Brian Behlendorf <[email protected]>

5 files changed, 1679 insertions, 0 deletions

diff --git a/module/Makefile.in b/module/Makefile.in
index 489119ab3..f59f04479 100644
--- a/module/Makefile.in
+++ b/module/Makefile.in
@@ -3,6 +3,7 @@ subdir-m += nvpair
 subdir-m += unicode
 subdir-m += zcommon
 subdir-m += zfs
+subdir-m += zpios
 
 modules:
 	# Make the exported SPL symbols available to these modules.
diff --git a/module/zpios/Makefile.in b/module/zpios/Makefile.in
new file mode 100644
index 000000000..4924082a1
--- /dev/null
+++ b/module/zpios/Makefile.in
@@ -0,0 +1,11 @@
+MODULE := zpios
+
+EXTRA_CFLAGS  = -I@MODDIR@/zfs/include
+EXTRA_CFLAGS += -I@MODDIR@/zcommon/include
+EXTRA_CFLAGS += -I@MODDIR@/avl/include
+EXTRA_CFLAGS += -I@MODDIR@/nvpair/include
+EXTRA_CFLAGS += -I@MODDIR@/unicode/include
+EXTRA_CFLAGS += -I@MODDIR@/zpios/include
+EXTRA_CFLAGS += @KERNELCPPFLAGS@
+
+obj-m := ${MODULE}.o
diff --git a/module/zpios/include/zpios-ctl.h b/module/zpios/include/zpios-ctl.h
new file mode 100644
index 000000000..234e96c11
--- /dev/null
+++ b/module/zpios/include/zpios-ctl.h
@@ -0,0 +1,198 @@
+/*****************************************************************************\
+ *  ZPIOS is a heavily modified version of the original PIOS test code.
+ *  It is designed to have the test code running in the Linux kernel
+ *  against ZFS while still being flexibly controled from user space.
+ *
+ *  Copyright (C) 2008-2010 Lawrence Livermore National Security, LLC.
+ *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
+ *  Written by Brian Behlendorf <[email protected]>.
+ *  LLNL-CODE-403049
+ *
+ *  Original PIOS Test Code
+ *  Copyright (C) 2004 Cluster File Systems, Inc.
+ *  Written by Peter Braam <[email protected]>
+ *             Atul Vidwansa <[email protected]>
+ *             Milind Dumbare <[email protected]>
+ *
+ *  This file is part of ZFS on Linux.
+ *  For details, see <http://github.com/behlendorf/zfs/>.
+ *
+ *  ZPIOS is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation; either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  ZPIOS is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with ZPIOS.  If not, see <http://www.gnu.org/licenses/>.
+\*****************************************************************************/
+
+#ifndef _ZPIOS_CTL_H
+#define _ZPIOS_CTL_H
+
+/* Contains shared definitions which both the userspace
+ * and kernelspace portions of zpios must agree on.
+ */
+#ifndef _KERNEL
+#include <stdint.h>
+#endif
+
+#define ZPIOS_MAJOR			232 /* XXX - Arbitrary */
+#define ZPIOS_MINORS			1
+#define ZPIOS_NAME			"zpios"
+#define ZPIOS_DEV			"/dev/zpios"
+
+#define DMU_IO				0x01
+
+#define DMU_WRITE			0x0001
+#define DMU_READ			0x0002
+#define DMU_VERIFY			0x0004
+#define DMU_REMOVE			0x0008
+#define DMU_FPP				0x0010
+#define DMU_WRITE_ZC			0x0020 /* Incompatible w/DMU_VERIFY */
+#define DMU_READ_ZC			0x0040 /* Incompatible w/DMU_VERIFY */
+#define DMU_WRITE_NOWAIT		0x0080
+#define DMU_READ_NOPF			0x0100
+
+#define ZPIOS_NAME_SIZE			16
+#define ZPIOS_PATH_SIZE			128
+
+#define PHASE_PRE_RUN			"pre-run"
+#define PHASE_PRE_CREATE		"pre-create"
+#define PHASE_PRE_WRITE			"pre-write"
+#define PHASE_PRE_READ			"pre-read"
+#define PHASE_PRE_REMOVE		"pre-remove"
+#define PHASE_POST_RUN			"post-run"
+#define PHASE_POST_CREATE		"post-create"
+#define PHASE_POST_WRITE		"post-write"
+#define PHASE_POST_READ			"post-read"
+#define PHASE_POST_REMOVE		"post-remove"
+
+#define	ZPIOS_CFG_MAGIC			0x87237190U
+typedef struct zpios_cfg {
+	uint32_t cfg_magic;		/* Unique magic */
+	int32_t cfg_cmd;		/* Config command */
+	int32_t cfg_arg1;		/* Config command arg 1 */
+	int32_t cfg_rc1;		/* Config response 1 */
+} zpios_cfg_t;
+
+typedef struct zpios_timespec {
+	uint32_t ts_sec;
+	uint32_t ts_nsec;
+} zpios_timespec_t;
+
+typedef struct zpios_time {
+	zpios_timespec_t start;
+	zpios_timespec_t stop;
+	zpios_timespec_t delta;
+} zpios_time_t;
+
+typedef struct zpios_stats {
+	zpios_time_t total_time;
+	zpios_time_t cr_time;
+	zpios_time_t rm_time;
+	zpios_time_t wr_time;
+	zpios_time_t rd_time;
+	uint64_t wr_data;
+	uint64_t wr_chunks;
+	uint64_t rd_data;
+	uint64_t rd_chunks;
+} zpios_stats_t;
+
+#define	ZPIOS_CMD_MAGIC			0x49715385U
+typedef struct zpios_cmd {
+	uint32_t cmd_magic;		/* Unique magic */
+	uint32_t cmd_id;		/* Run ID */
+	char cmd_pool[ZPIOS_NAME_SIZE];	/* Pool name */
+	uint64_t cmd_chunk_size;	/* Chunk size */
+	uint32_t cmd_thread_count;	/* Thread count */
+	uint32_t cmd_region_count;	/* Region count */
+	uint64_t cmd_region_size;	/* Region size */
+	uint64_t cmd_offset;		/* Region offset */
+	uint32_t cmd_region_noise;	/* Region noise */
+	uint32_t cmd_chunk_noise;	/* Chunk noise */
+	uint32_t cmd_thread_delay;	/* Thread delay */
+	uint32_t cmd_flags;		/* Test flags */
+        char cmd_pre[ZPIOS_PATH_SIZE];	/* Pre-exec hook */
+        char cmd_post[ZPIOS_PATH_SIZE];	/* Post-exec hook */
+	char cmd_log[ZPIOS_PATH_SIZE];  /* Requested log dir */
+	uint64_t cmd_data_size;		/* Opaque data size */
+	char cmd_data_str[0];		/* Opaque data region */
+} zpios_cmd_t;
+
+/* Valid ioctls */
+#define ZPIOS_CFG			_IOWR('f', 101, zpios_cfg_t)
+#define ZPIOS_CMD			_IOWR('f', 102, zpios_cmd_t)
+
+/* Valid configuration commands */
+#define ZPIOS_CFG_BUFFER_CLEAR		0x001	/* Clear text buffer */
+#define ZPIOS_CFG_BUFFER_SIZE		0x002	/* Resize text buffer */
+
+#ifndef NSEC_PER_SEC
+#define NSEC_PER_SEC    1000000000L
+#endif
+
+static inline
+void zpios_timespec_normalize(zpios_timespec_t *ts, uint32_t sec, uint32_t nsec)
+{
+	while (nsec >= NSEC_PER_SEC) {
+		nsec -= NSEC_PER_SEC;
+		sec++;
+	}
+	while (nsec < 0) {
+		nsec += NSEC_PER_SEC;
+		sec--;
+	}
+	ts->ts_sec = sec;
+	ts->ts_nsec = nsec;
+}
+
+static inline
+zpios_timespec_t zpios_timespec_add(zpios_timespec_t lhs, zpios_timespec_t rhs)
+{
+	zpios_timespec_t ts_delta;
+	zpios_timespec_normalize(&ts_delta, lhs.ts_sec + rhs.ts_sec,
+	                         lhs.ts_nsec + rhs.ts_nsec);
+        return ts_delta;
+}
+
+static inline
+zpios_timespec_t zpios_timespec_sub(zpios_timespec_t lhs, zpios_timespec_t rhs)
+{
+	zpios_timespec_t ts_delta;
+	zpios_timespec_normalize(&ts_delta, lhs.ts_sec - rhs.ts_sec,
+	                         lhs.ts_nsec - rhs.ts_nsec);
+	return ts_delta;
+}
+
+#ifdef _KERNEL
+
+static inline
+zpios_timespec_t zpios_timespec_now(void)
+{
+	zpios_timespec_t zts_now;
+	struct timespec ts_now;
+
+	ts_now = current_kernel_time();
+	zts_now.ts_sec  = ts_now.tv_sec;
+	zts_now.ts_nsec = ts_now.tv_nsec;
+
+	return zts_now;
+}
+
+#else
+
+static inline
+double zpios_timespec_to_double(zpios_timespec_t ts)
+{
+	return ((double)(ts.ts_sec) +
+	       ((double)(ts.ts_nsec) / (double)(NSEC_PER_SEC)));
+}
+
+#endif /* _KERNEL */
+
+#endif /* _ZPIOS_CTL_H */
diff --git a/module/zpios/include/zpios-internal.h b/module/zpios/include/zpios-internal.h
new file mode 100644
index 000000000..c9b6e0092
--- /dev/null
+++ b/module/zpios/include/zpios-internal.h
@@ -0,0 +1,138 @@
+/*****************************************************************************\
+ *  ZPIOS is a heavily modified version of the original PIOS test code.
+ *  It is designed to have the test code running in the Linux kernel
+ *  against ZFS while still being flexibly controled from user space.
+ *
+ *  Copyright (C) 2008-2010 Lawrence Livermore National Security, LLC.
+ *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
+ *  Written by Brian Behlendorf <[email protected]>.
+ *  LLNL-CODE-403049
+ *
+ *  Original PIOS Test Code
+ *  Copyright (C) 2004 Cluster File Systems, Inc.
+ *  Written by Peter Braam <[email protected]>
+ *             Atul Vidwansa <[email protected]>
+ *             Milind Dumbare <[email protected]>
+ *
+ *  This file is part of ZFS on Linux.
+ *  For details, see <http://github.com/behlendorf/zfs/>.
+ *
+ *  ZPIOS is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation; either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  ZPIOS is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with ZPIOS.  If not, see <http://www.gnu.org/licenses/>.
+\*****************************************************************************/
+
+#ifndef _ZPIOS_INTERNAL_H
+#define _ZPIOS_INTERNAL_H
+
+#include "zpios-ctl.h"
+
+#define OBJ_SIZE	64
+
+struct run_args;
+
+typedef struct dmu_obj {
+	objset_t *os;
+	uint64_t obj;
+} dmu_obj_t;
+
+/* thread doing the IO data */
+typedef struct thread_data {
+	struct run_args *run_args;
+	int thread_no;
+	int rc;
+	zpios_stats_t stats;
+        kmutex_t lock;
+} thread_data_t;
+
+/* region for IO data */
+typedef struct zpios_region {
+	__u64 wr_offset;
+	__u64 rd_offset;
+	__u64 init_offset;
+	__u64 max_offset;
+	dmu_obj_t obj;
+	zpios_stats_t stats;
+        kmutex_t lock;
+} zpios_region_t;
+
+/* arguments for one run */
+typedef struct run_args {
+	/* Config args */
+	int id;
+	char pool[ZPIOS_NAME_SIZE];
+	__u64 chunk_size;
+	__u32 thread_count;
+	__u32 region_count;
+	__u64 region_size;
+	__u64 offset;
+	__u32 region_noise;
+	__u32 chunk_noise;
+	__u32 thread_delay;
+	__u32 flags;
+	char pre[ZPIOS_PATH_SIZE];
+	char post[ZPIOS_PATH_SIZE];
+	char log[ZPIOS_PATH_SIZE];
+
+	/* Control data */
+	objset_t *os;
+        wait_queue_head_t waitq;
+	volatile uint64_t threads_done;
+        kmutex_t lock_work;
+	kmutex_t lock_ctl;
+	__u32 region_next;
+
+	/* Results data */
+	struct file *file;
+	zpios_stats_t stats;
+
+	thread_data_t **threads;
+	zpios_region_t regions[0]; /* Must be last element */
+} run_args_t;
+
+#define ZPIOS_INFO_BUFFER_SIZE          65536
+#define ZPIOS_INFO_BUFFER_REDZONE       1024
+
+typedef struct zpios_info {
+        spinlock_t info_lock;
+        int info_size;
+        char *info_buffer;
+        char *info_head;        /* Internal kernel use only */
+} zpios_info_t;
+
+#define zpios_print(file, format, args...)                              \
+({      zpios_info_t *_info_ = (zpios_info_t *)file->private_data;      \
+        int _rc_;                                                       \
+                                                                        \
+        ASSERT(_info_);                                                 \
+        ASSERT(_info_->info_buffer);                                    \
+                                                                        \
+        spin_lock(&_info_->info_lock);                                  \
+                                                                        \
+        /* Don't allow the kernel to start a write in the red zone */   \
+        if ((int)(_info_->info_head - _info_->info_buffer) >            \
+            (_info_->info_size - ZPIOS_INFO_BUFFER_REDZONE))      {     \
+                _rc_ = -EOVERFLOW;                                      \
+        } else {                                                        \
+                _rc_ = sprintf(_info_->info_head, format, args);        \
+                if (_rc_ >= 0)                                          \
+                        _info_->info_head += _rc_;                      \
+        }                                                               \
+                                                                        \
+        spin_unlock(&_info_->info_lock);                                \
+        _rc_;                                                           \
+})
+
+#define zpios_vprint(file, test, format, args...)                       \
+        zpios_print(file, "%*s: " format, ZPIOS_NAME_SIZE, test, args)
+
+#endif /* _ZPIOS_INTERNAL_H */
diff --git a/module/zpios/zpios.c b/module/zpios/zpios.c
new file mode 100644
index 000000000..3edc16105
--- /dev/null
+++ b/module/zpios/zpios.c
@@ -0,0 +1,1331 @@
+/*****************************************************************************\
+ *  ZPIOS is a heavily modified version of the original PIOS test code.
+ *  It is designed to have the test code running in the Linux kernel
+ *  against ZFS while still being flexibly controled from user space.
+ *
+ *  Copyright (C) 2008-2010 Lawrence Livermore National Security, LLC.
+ *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
+ *  Written by Brian Behlendorf <[email protected]>.
+ *  LLNL-CODE-403049
+ *
+ *  Original PIOS Test Code
+ *  Copyright (C) 2004 Cluster File Systems, Inc.
+ *  Written by Peter Braam <[email protected]>
+ *             Atul Vidwansa <[email protected]>
+ *             Milind Dumbare <[email protected]>
+ *
+ *  This file is part of ZFS on Linux.
+ *  For details, see <http://github.com/behlendorf/zfs/>.
+ *
+ *  ZPIOS is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation; either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  ZPIOS is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with ZPIOS.  If not, see <http://www.gnu.org/licenses/>.
+\*****************************************************************************/
+
+#include <sys/zfs_context.h>
+#include <sys/dmu.h>
+#include <sys/txg.h>
+#include <linux/cdev.h>
+#include "zpios-internal.h"
+
+
+static spl_class *zpios_class;
+static spl_device *zpios_device;
+static char *zpios_tag = "zpios_tag";
+
+static
+int zpios_upcall(char *path, char *phase, run_args_t *run_args, int rc)
+{
+	/* This is stack heavy but it should be OK since we are only
+	 * making the upcall between tests when the stack is shallow.
+	 */
+        char id[16], chunk_size[16], region_size[16], thread_count[16];
+	char region_count[16], offset[16], region_noise[16], chunk_noise[16];
+        char thread_delay[16], flags[16], result[8];
+        char *argv[16], *envp[4];
+
+	if ((path == NULL) || (strlen(path) == 0))
+		return -ENOENT;
+
+	snprintf(id, 15, "%d", run_args->id);
+	snprintf(chunk_size, 15, "%lu", (long unsigned)run_args->chunk_size);
+        snprintf(region_size, 15, "%lu",(long unsigned) run_args->region_size);
+	snprintf(thread_count, 15, "%u", run_args->thread_count);
+	snprintf(region_count, 15, "%u", run_args->region_count);
+	snprintf(offset, 15, "%lu", (long unsigned)run_args->offset);
+	snprintf(region_noise, 15, "%u", run_args->region_noise);
+	snprintf(chunk_noise, 15, "%u", run_args->chunk_noise);
+	snprintf(thread_delay, 15, "%u", run_args->thread_delay);
+	snprintf(flags, 15, "0x%x", run_args->flags);
+	snprintf(result, 7, "%d", rc);
+
+	/* Passing 15 args to registered pre/post upcall */
+        argv[0] = path;
+	argv[1] = phase;
+	argv[2] = strlen(run_args->log) ? run_args->log : "<none>";
+	argv[3] = id;
+	argv[4] = run_args->pool;
+	argv[5] = chunk_size;
+	argv[6] = region_size;
+	argv[7] = thread_count;
+	argv[8] = region_count;
+	argv[9] = offset;
+	argv[10] = region_noise;
+	argv[11] = chunk_noise;
+	argv[12] = thread_delay;
+	argv[13] = flags;
+	argv[14] = result;
+	argv[15] = NULL;
+
+	/* Passing environment for user space upcall */
+        envp[0] = "HOME=/";
+        envp[1] = "TERM=linux";
+        envp[2] = "PATH=/sbin:/usr/sbin:/bin:/usr/bin";
+        envp[3] = NULL;
+
+        return call_usermodehelper(path, argv, envp, 1);
+}
+
+static uint64_t
+zpios_dmu_object_create(run_args_t *run_args, objset_t *os)
+{
+	struct dmu_tx *tx;
+        uint64_t obj = 0ULL;
+	int rc;
+
+	tx = dmu_tx_create(os);
+	dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, OBJ_SIZE);
+	rc = dmu_tx_assign(tx, TXG_WAIT);
+	if (rc) {
+		zpios_print(run_args->file,
+			    "dmu_tx_assign() failed: %d\n", rc);
+		dmu_tx_abort(tx);
+		return obj;
+	}
+
+	obj = dmu_object_alloc(os, DMU_OT_UINT64_OTHER, 0,
+	                       DMU_OT_NONE, 0, tx);
+	rc = dmu_object_set_blocksize(os, obj, 128ULL << 10, 0, tx);
+	if (rc) {
+		zpios_print(run_args->file,
+			    "dmu_object_set_blocksize() failed: %d\n", rc);
+	        dmu_tx_abort(tx);
+	        return obj;
+	}
+
+	dmu_tx_commit(tx);
+
+	return obj;
+}
+
+static int
+zpios_dmu_object_free(run_args_t *run_args, objset_t *os, uint64_t obj)
+{
+	struct dmu_tx *tx;
+	int rc;
+
+	tx = dmu_tx_create(os);
+        dmu_tx_hold_free(tx, obj, 0, DMU_OBJECT_END);
+	rc = dmu_tx_assign(tx, TXG_WAIT);
+	if (rc) {
+		zpios_print(run_args->file,
+			    "dmu_tx_assign() failed: %d\n", rc);
+		dmu_tx_abort(tx);
+		return rc;
+	}
+
+	rc = dmu_object_free(os, obj, tx);
+	if (rc) {
+		zpios_print(run_args->file,
+			    "dmu_object_free() failed: %d\n", rc);
+	        dmu_tx_abort(tx);
+	        return rc;
+	}
+
+	dmu_tx_commit(tx);
+
+	return 0;
+}
+
+static int
+zpios_dmu_setup(run_args_t *run_args)
+{
+	zpios_time_t *t = &(run_args->stats.cr_time);
+	objset_t *os;
+	char name[32];
+	uint64_t obj = 0ULL;
+	int i, rc = 0, rc2;
+
+	(void)zpios_upcall(run_args->pre, PHASE_PRE_CREATE, run_args, 0);
+	t->start = zpios_timespec_now();
+
+	(void)snprintf(name, 32, "%s/id_%d", run_args->pool, run_args->id);
+	rc = dmu_objset_create(name, DMU_OST_OTHER, 0, NULL, NULL);
+	if (rc) {
+		zpios_print(run_args->file, "Error dmu_objset_create(%s, ...) "
+			    "failed: %d\n", name, rc);
+		goto out;
+	}
+
+        rc = dmu_objset_own(name, DMU_OST_OTHER, 0, zpios_tag, &os);
+        if (rc) {
+		zpios_print(run_args->file, "Error dmu_objset_own(%s, ...) "
+			    "failed: %d\n", name, rc);
+		goto out_destroy;
+        }
+
+	if (!(run_args->flags & DMU_FPP)) {
+		obj = zpios_dmu_object_create(run_args, os);
+		if (obj == 0) {
+			rc = -EBADF;
+			zpios_print(run_args->file, "Error zpios_dmu_"
+				    "object_create() failed, %d\n", rc);
+			goto out_destroy;
+		}
+	}
+
+	for (i = 0; i < run_args->region_count; i++) {
+		zpios_region_t *region;
+
+		region = &run_args->regions[i];
+	        mutex_init(&region->lock, NULL, MUTEX_DEFAULT, NULL);
+
+		if (run_args->flags & DMU_FPP) {
+			/* File per process */
+			region->obj.os  = os;
+			region->obj.obj = zpios_dmu_object_create(run_args, os);
+			ASSERT(region->obj.obj > 0); /* XXX - Handle this */
+			region->wr_offset   = run_args->offset;
+			region->rd_offset   = run_args->offset;
+			region->init_offset = run_args->offset;
+			region->max_offset  = run_args->offset +
+			                      run_args->region_size;
+		} else {
+			/* Single shared file */
+			region->obj.os  = os;
+			region->obj.obj = obj;
+			region->wr_offset   = run_args->offset * i;
+			region->rd_offset   = run_args->offset * i;
+			region->init_offset = run_args->offset * i;
+			region->max_offset  = run_args->offset *
+			                      i + run_args->region_size;
+		}
+	}
+
+	run_args->os = os;
+out_destroy:
+	if (rc) {
+		rc2 = dmu_objset_destroy(name, B_FALSE);
+		if (rc2)
+			zpios_print(run_args->file, "Error dmu_objset_destroy"
+				    "(%s, ...) failed: %d\n", name, rc2);
+	}
+out:
+	t->stop  = zpios_timespec_now();
+	t->delta = zpios_timespec_sub(t->stop, t->start);
+	(void)zpios_upcall(run_args->post, PHASE_POST_CREATE, run_args, rc);
+
+	return rc;
+}
+
+static int
+zpios_setup_run(run_args_t **run_args, zpios_cmd_t *kcmd, struct file *file)
+{
+	run_args_t *ra;
+	int rc, size;
+
+	size = sizeof(*ra) + kcmd->cmd_region_count * sizeof(zpios_region_t);
+
+	ra = vmem_zalloc(size, KM_SLEEP);
+	if (ra == NULL) {
+		zpios_print(file, "Unable to vmem_zalloc() %d bytes "
+			    "for regions\n", size);
+		return -ENOMEM;
+	}
+
+	*run_args = ra;
+	strncpy(ra->pool, kcmd->cmd_pool, ZPIOS_NAME_SIZE - 1);
+	strncpy(ra->pre, kcmd->cmd_pre, ZPIOS_PATH_SIZE - 1);
+	strncpy(ra->post, kcmd->cmd_post, ZPIOS_PATH_SIZE - 1);
+	strncpy(ra->log, kcmd->cmd_log, ZPIOS_PATH_SIZE - 1);
+	ra->id              = kcmd->cmd_id;
+	ra->chunk_size      = kcmd->cmd_chunk_size;
+	ra->thread_count    = kcmd->cmd_thread_count;
+	ra->region_count    = kcmd->cmd_region_count;
+	ra->region_size     = kcmd->cmd_region_size;
+	ra->offset          = kcmd->cmd_offset;
+	ra->region_noise    = kcmd->cmd_region_noise;
+	ra->chunk_noise     = kcmd->cmd_chunk_noise;
+	ra->thread_delay    = kcmd->cmd_thread_delay;
+	ra->flags           = kcmd->cmd_flags;
+	ra->stats.wr_data   = 0;
+	ra->stats.wr_chunks = 0;
+	ra->stats.rd_data   = 0;
+	ra->stats.rd_chunks = 0;
+	ra->region_next     = 0;
+	ra->file            = file;
+        mutex_init(&ra->lock_work, NULL, MUTEX_DEFAULT, NULL);
+        mutex_init(&ra->lock_ctl, NULL, MUTEX_DEFAULT, NULL);
+
+	(void)zpios_upcall(ra->pre, PHASE_PRE_RUN, ra, 0);
+
+	rc = zpios_dmu_setup(ra);
+	if (rc) {
+	        mutex_destroy(&ra->lock_ctl);
+	        mutex_destroy(&ra->lock_work);
+		vmem_free(ra, size);
+		*run_args = NULL;
+	}
+
+	return rc;
+}
+
+static int
+zpios_get_work_item(run_args_t *run_args, dmu_obj_t *obj, __u64 *offset,
+		    __u32 *chunk_size, zpios_region_t **region, __u32 flags)
+{
+	int i, j, count = 0;
+	unsigned int random_int;
+
+	get_random_bytes(&random_int, sizeof(unsigned int));
+
+	mutex_enter(&run_args->lock_work);
+	i = run_args->region_next;
+
+	/* XXX: I don't much care for this chunk selection mechansim
+	 * there's the potential to burn a lot of time here doing nothing
+	 * useful while holding the global lock.  This could give some
+	 * misleading performance results.  I'll fix it latter.
+	 */
+	while (count < run_args->region_count) {
+		__u64 *rw_offset;
+		zpios_time_t *rw_time;
+
+		j = i % run_args->region_count;
+		*region = &(run_args->regions[j]);
+
+		if (flags & DMU_WRITE) {
+			rw_offset = &((*region)->wr_offset);
+			rw_time = &((*region)->stats.wr_time);
+		} else {
+			rw_offset = &((*region)->rd_offset);
+			rw_time = &((*region)->stats.rd_time);
+		}
+
+		/* test if region is fully written */
+		if (*rw_offset + *chunk_size > (*region)->max_offset) {
+			i++;
+			count++;
+
+			if (unlikely(rw_time->stop.ts_sec == 0) &&
+			    unlikely(rw_time->stop.ts_nsec == 0))
+				rw_time->stop = zpios_timespec_now();
+
+			continue;
+		}
+
+		*offset = *rw_offset;
+		*obj = (*region)->obj;
+		*rw_offset += *chunk_size;
+
+		/* update ctl structure */
+		if (run_args->region_noise) {
+			get_random_bytes(&random_int, sizeof(unsigned int));
+	                run_args->region_next += random_int % run_args->region_noise;
+		} else {
+			run_args->region_next++;
+		}
+
+		mutex_exit(&run_args->lock_work);
+		return 1;
+	}
+
+	/* nothing left to do */
+	mutex_exit(&run_args->lock_work);
+
+	return 0;
+}
+
+static void
+zpios_remove_objset(run_args_t *run_args)
+{
+	zpios_time_t *t = &(run_args->stats.rm_time);
+	zpios_region_t *region;
+	char name[32];
+	int rc = 0, i;
+
+	(void)zpios_upcall(run_args->pre, PHASE_PRE_REMOVE, run_args, 0);
+	t->start = zpios_timespec_now();
+
+	(void)snprintf(name, 32, "%s/id_%d", run_args->pool, run_args->id);
+
+	if (run_args->flags & DMU_REMOVE) {
+		if (run_args->flags & DMU_FPP) {
+			for (i = 0; i < run_args->region_count; i++) {
+				region = &run_args->regions[i];
+				rc = zpios_dmu_object_free(run_args,
+							   region->obj.os,
+							   region->obj.obj);
+				if (rc)
+					zpios_print(run_args->file, "Error "
+						    "removing object %d, %d\n",
+					            (int)region->obj.obj, rc);
+			}
+		} else {
+			region = &run_args->regions[0];
+			rc = zpios_dmu_object_free(run_args,
+						   region->obj.os,
+						   region->obj.obj);
+			if (rc)
+				zpios_print(run_args->file, "Error "
+					    "removing object %d, %d\n",
+				            (int)region->obj.obj, rc);
+		}
+	}
+
+	dmu_objset_disown(run_args->os, zpios_tag);
+
+	if (run_args->flags & DMU_REMOVE) {
+		rc = dmu_objset_destroy(name, B_FALSE);
+		if (rc)
+			zpios_print(run_args->file, "Error dmu_objset_destroy"
+				    "(%s, ...) failed: %d\n", name, rc);
+	}
+
+	t->stop  = zpios_timespec_now();
+	t->delta = zpios_timespec_sub(t->stop, t->start);
+	(void)zpios_upcall(run_args->post, PHASE_POST_REMOVE, run_args, rc);
+}
+
+static void
+zpios_cleanup_run(run_args_t *run_args)
+{
+	int i, size = 0;
+
+	if (run_args == NULL)
+		return;
+
+	if (run_args->threads != NULL) {
+		for (i = 0; i < run_args->thread_count; i++) {
+			if (run_args->threads[i]) {
+				mutex_destroy(&run_args->threads[i]->lock);
+				kmem_free(run_args->threads[i],
+					  sizeof(thread_data_t));
+			}
+		}
+
+		kmem_free(run_args->threads,
+			  sizeof(thread_data_t *) * run_args->thread_count);
+	}
+
+	for (i = 0; i < run_args->region_count; i++)
+		mutex_destroy(&run_args->regions[i].lock);
+
+	mutex_destroy(&run_args->lock_work);
+	mutex_destroy(&run_args->lock_ctl);
+	size = run_args->region_count * sizeof(zpios_region_t);
+
+	vmem_free(run_args, sizeof(*run_args) + size);
+}
+
+static int
+zpios_dmu_write(run_args_t *run_args, objset_t *os, uint64_t object,
+		uint64_t offset, uint64_t size, const void *buf)
+{
+	struct dmu_tx *tx;
+	int rc, how = TXG_WAIT;
+//	int flags = 0;
+
+	if (run_args->flags & DMU_WRITE_NOWAIT)
+		how = TXG_NOWAIT;
+
+	while (1) {
+		tx = dmu_tx_create(os);
+		dmu_tx_hold_write(tx, object, offset, size);
+		rc = dmu_tx_assign(tx, how);
+
+		if (rc) {
+			if (rc == ERESTART && how == TXG_NOWAIT) {
+				dmu_tx_wait(tx);
+				dmu_tx_abort(tx);
+				continue;
+			}
+			zpios_print(run_args->file,
+				    "Error in dmu_tx_assign(), %d", rc);
+			dmu_tx_abort(tx);
+			return rc;
+		}
+		break;
+	}
+
+//	if (run_args->flags & DMU_WRITE_ZC)
+//		flags |= DMU_WRITE_ZEROCOPY;
+
+	dmu_write(os, object, offset, size, buf, tx);
+	dmu_tx_commit(tx);
+
+	return 0;
+}
+
+static int
+zpios_dmu_read(run_args_t *run_args, objset_t *os, uint64_t object,
+	       uint64_t offset, uint64_t size, void *buf)
+{
+	int flags = 0;
+
+//	if (run_args->flags & DMU_READ_ZC)
+//		flags |= DMU_READ_ZEROCOPY;
+
+	if (run_args->flags & DMU_READ_NOPF)
+		flags |= DMU_READ_NO_PREFETCH;
+
+	return dmu_read(os, object, offset, size, buf, flags);
+}
+
+static int
+zpios_thread_main(void *data)
+{
+	thread_data_t *thr = (thread_data_t *)data;
+	run_args_t *run_args = thr->run_args;
+	zpios_time_t t;
+	dmu_obj_t obj;
+	__u64 offset;
+	__u32 chunk_size;
+	zpios_region_t *region;
+	char *buf;
+	unsigned int random_int;
+	int chunk_noise = run_args->chunk_noise;
+	int chunk_noise_tmp = 0;
+	int thread_delay = run_args->thread_delay;
+	int thread_delay_tmp = 0;
+	int i, rc = 0;
+
+	if (chunk_noise) {
+		get_random_bytes(&random_int, sizeof(unsigned int));
+		chunk_noise_tmp = (random_int % (chunk_noise * 2))-chunk_noise;
+	}
+
+	/* It's OK to vmem_alloc() this memory because it will be copied
+	 * in to the slab and pointers to the slab copy will be setup in
+	 * the bio when the IO is submitted.  This of course is not ideal
+	 * since we want a zero-copy IO path if possible.  It would be nice
+	 * to have direct access to those slab entries.
+	 */
+	chunk_size = run_args->chunk_size + chunk_noise_tmp;
+	buf = (char *)vmem_alloc(chunk_size, KM_SLEEP);
+	ASSERT(buf);
+
+	/* Trivial data verification pattern for now. */
+	if (run_args->flags & DMU_VERIFY)
+		memset(buf, 'z', chunk_size);
+
+	/* Write phase */
+	mutex_enter(&thr->lock);
+	thr->stats.wr_time.start = zpios_timespec_now();
+	mutex_exit(&thr->lock);
+
+	while (zpios_get_work_item(run_args, &obj, &offset,
+				   &chunk_size, &region, DMU_WRITE)) {
+		if (thread_delay) {
+			get_random_bytes(&random_int, sizeof(unsigned int));
+			thread_delay_tmp = random_int % thread_delay;
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			schedule_timeout(thread_delay_tmp); /* In jiffies */
+		}
+
+		t.start = zpios_timespec_now();
+		rc = zpios_dmu_write(run_args, obj.os, obj.obj,
+				     offset, chunk_size, buf);
+		t.stop  = zpios_timespec_now();
+		t.delta = zpios_timespec_sub(t.stop, t.start);
+
+		if (rc) {
+			zpios_print(run_args->file, "IO error while doing "
+				    "dmu_write(): %d\n", rc);
+			break;
+		}
+
+		mutex_enter(&thr->lock);
+		thr->stats.wr_data += chunk_size;
+		thr->stats.wr_chunks++;
+		thr->stats.wr_time.delta = zpios_timespec_add(
+		        thr->stats.wr_time.delta, t.delta);
+		mutex_exit(&thr->lock);
+
+		mutex_enter(&region->lock);
+		region->stats.wr_data += chunk_size;
+		region->stats.wr_chunks++;
+		region->stats.wr_time.delta = zpios_timespec_add(
+		        region->stats.wr_time.delta, t.delta);
+
+		/* First time region was accessed */
+		if (region->init_offset == offset)
+			region->stats.wr_time.start = t.start;
+
+		mutex_exit(&region->lock);
+	}
+
+	mutex_enter(&run_args->lock_ctl);
+	run_args->threads_done++;
+	mutex_exit(&run_args->lock_ctl);
+
+	mutex_enter(&thr->lock);
+	thr->rc = rc;
+	thr->stats.wr_time.stop = zpios_timespec_now();
+	mutex_exit(&thr->lock);
+	wake_up(&run_args->waitq);
+
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	schedule();
+
+	/* Check if we should exit */
+	mutex_enter(&thr->lock);
+	rc = thr->rc;
+	mutex_exit(&thr->lock);
+	if (rc)
+		goto out;
+
+	/* Read phase */
+	mutex_enter(&thr->lock);
+	thr->stats.rd_time.start = zpios_timespec_now();
+	mutex_exit(&thr->lock);
+
+	while (zpios_get_work_item(run_args, &obj, &offset,
+				   &chunk_size, &region, DMU_READ)) {
+		if (thread_delay) {
+			get_random_bytes(&random_int, sizeof(unsigned int));
+			thread_delay_tmp = random_int % thread_delay;
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			schedule_timeout(thread_delay_tmp); /* In jiffies */
+		}
+
+		if (run_args->flags & DMU_VERIFY)
+			memset(buf, 0, chunk_size);
+
+		t.start = zpios_timespec_now();
+		rc = zpios_dmu_read(run_args, obj.os, obj.obj,
+				    offset, chunk_size, buf);
+		t.stop  = zpios_timespec_now();
+		t.delta = zpios_timespec_sub(t.stop, t.start);
+
+		if (rc) {
+			zpios_print(run_args->file, "IO error while doing "
+				    "dmu_read(): %d\n", rc);
+			break;
+		}
+
+		/* Trivial data verification, expensive! */
+		if (run_args->flags & DMU_VERIFY) {
+			for (i = 0; i < chunk_size; i++) {
+				if (buf[i] != 'z') {
+					zpios_print(run_args->file,
+						    "IO verify error: %d/%d/%d\n",
+					            (int)obj.obj, (int)offset,
+					            (int)chunk_size);
+					break;
+				}
+			}
+		}
+
+		mutex_enter(&thr->lock);
+		thr->stats.rd_data += chunk_size;
+		thr->stats.rd_chunks++;
+		thr->stats.rd_time.delta = zpios_timespec_add(
+		        thr->stats.rd_time.delta, t.delta);
+		mutex_exit(&thr->lock);
+
+		mutex_enter(&region->lock);
+		region->stats.rd_data += chunk_size;
+		region->stats.rd_chunks++;
+		region->stats.rd_time.delta = zpios_timespec_add(
+		        region->stats.rd_time.delta, t.delta);
+
+		/* First time region was accessed */
+		if (region->init_offset == offset)
+			region->stats.rd_time.start = t.start;
+
+		mutex_exit(&region->lock);
+	}
+
+	mutex_enter(&run_args->lock_ctl);
+	run_args->threads_done++;
+	mutex_exit(&run_args->lock_ctl);
+
+	mutex_enter(&thr->lock);
+	thr->rc = rc;
+	thr->stats.rd_time.stop = zpios_timespec_now();
+	mutex_exit(&thr->lock);
+	wake_up(&run_args->waitq);
+
+out:
+	vmem_free(buf, chunk_size);
+	do_exit(0);
+
+	return rc; /* Unreachable, due to do_exit() */
+}
+
+static int
+zpios_thread_done(run_args_t *run_args)
+{
+	ASSERT(run_args->threads_done <= run_args->thread_count);
+	return (run_args->threads_done == run_args->thread_count);
+}
+
+static int
+zpios_threads_run(run_args_t *run_args)
+{
+	struct task_struct *tsk, **tsks;
+	thread_data_t *thr = NULL;
+	zpios_time_t *tt = &(run_args->stats.total_time);
+	zpios_time_t *tw = &(run_args->stats.wr_time);
+	zpios_time_t *tr = &(run_args->stats.rd_time);
+	int i, rc = 0, tc = run_args->thread_count;
+
+	tsks = kmem_zalloc(sizeof(struct task_struct *) * tc, KM_SLEEP);
+	if (tsks == NULL) {
+		rc = -ENOMEM;
+		goto cleanup2;
+	}
+
+	run_args->threads = kmem_zalloc(sizeof(thread_data_t *) * tc, KM_SLEEP);
+	if (run_args->threads == NULL) {
+		rc = -ENOMEM;
+		goto cleanup;
+	}
+
+	init_waitqueue_head(&run_args->waitq);
+	run_args->threads_done = 0;
+
+	/* Create all the needed threads which will sleep until awoken */
+	for (i = 0; i < tc; i++) {
+		thr = kmem_zalloc(sizeof(thread_data_t), KM_SLEEP);
+		if (thr == NULL) {
+			rc = -ENOMEM;
+			goto taskerr;
+		}
+
+		thr->thread_no = i;
+		thr->run_args = run_args;
+		thr->rc = 0;
+		mutex_init(&thr->lock, NULL, MUTEX_DEFAULT, NULL);
+		run_args->threads[i] = thr;
+
+		tsk = kthread_create(zpios_thread_main, (void *)thr,
+		                     "%s/%d", "zpios_io", i);
+		if (IS_ERR(tsk)) {
+			rc = -EINVAL;
+			goto taskerr;
+		}
+
+		tsks[i] = tsk;
+	}
+
+	tt->start = zpios_timespec_now();
+
+	/* Wake up all threads for write phase */
+	(void)zpios_upcall(run_args->pre, PHASE_PRE_WRITE, run_args, 0);
+	for (i = 0; i < tc; i++)
+		wake_up_process(tsks[i]);
+
+	/* Wait for write phase to complete */
+	tw->start = zpios_timespec_now();
+	wait_event(run_args->waitq, zpios_thread_done(run_args));
+	tw->stop = zpios_timespec_now();
+	(void)zpios_upcall(run_args->post, PHASE_POST_WRITE, run_args, rc);
+
+	for (i = 0; i < tc; i++) {
+		thr = run_args->threads[i];
+
+		mutex_enter(&thr->lock);
+
+		if (!rc && thr->rc)
+			rc = thr->rc;
+
+		run_args->stats.wr_data += thr->stats.wr_data;
+		run_args->stats.wr_chunks += thr->stats.wr_chunks;
+		mutex_exit(&thr->lock);
+	}
+
+	if (rc) {
+		/* Wake up all threads and tell them to exit */
+		for (i = 0; i < tc; i++) {
+			mutex_enter(&thr->lock);
+			thr->rc = rc;
+			mutex_exit(&thr->lock);
+
+			wake_up_process(tsks[i]);
+		}
+		goto out;
+	}
+
+	mutex_enter(&run_args->lock_ctl);
+	ASSERT(run_args->threads_done == run_args->thread_count);
+	run_args->threads_done = 0;
+	mutex_exit(&run_args->lock_ctl);
+
+	/* Wake up all threads for read phase */
+	(void)zpios_upcall(run_args->pre, PHASE_PRE_READ, run_args, 0);
+        for (i = 0; i < tc; i++)
+		wake_up_process(tsks[i]);
+
+	/* Wait for read phase to complete */
+	tr->start = zpios_timespec_now();
+	wait_event(run_args->waitq, zpios_thread_done(run_args));
+	tr->stop = zpios_timespec_now();
+	(void)zpios_upcall(run_args->post, PHASE_POST_READ, run_args, rc);
+
+	for (i = 0; i < tc; i++) {
+		thr = run_args->threads[i];
+
+		mutex_enter(&thr->lock);
+
+		if (!rc && thr->rc)
+			rc = thr->rc;
+
+		run_args->stats.rd_data += thr->stats.rd_data;
+		run_args->stats.rd_chunks += thr->stats.rd_chunks;
+		mutex_exit(&thr->lock);
+	}
+out:
+	tt->stop  = zpios_timespec_now();
+	tt->delta = zpios_timespec_sub(tt->stop, tt->start);
+	tw->delta = zpios_timespec_sub(tw->stop, tw->start);
+	tr->delta = zpios_timespec_sub(tr->stop, tr->start);
+
+cleanup:
+	kmem_free(tsks, sizeof(struct task_struct *) * tc);
+cleanup2:
+	/* Returns first encountered thread error (if any) */
+	return rc;
+
+taskerr:
+	/* Destroy all threads that were created successfully */
+	for (i = 0; i < tc; i++)
+		if (tsks[i] != NULL)
+			(void) kthread_stop(tsks[i]);
+
+	goto cleanup;
+}
+
+static int
+zpios_do_one_run(struct file *file, zpios_cmd_t *kcmd,
+                 int data_size, void *data)
+{
+	run_args_t *run_args = { 0 };
+	zpios_stats_t *stats = (zpios_stats_t *)data;
+	int i, n, m, size, rc;
+
+	if ((!kcmd->cmd_chunk_size) || (!kcmd->cmd_region_size) ||
+	    (!kcmd->cmd_thread_count) || (!kcmd->cmd_region_count)) {
+		zpios_print(file, "Invalid chunk_size, region_size, "
+			    "thread_count, or region_count, %d\n", -EINVAL);
+		return -EINVAL;
+	}
+
+	if (!(kcmd->cmd_flags & DMU_WRITE) ||
+	    !(kcmd->cmd_flags & DMU_READ)) {
+		zpios_print(file, "Invalid flags, minimally DMU_WRITE "
+			    "and DMU_READ must be set, %d\n", -EINVAL);
+		return -EINVAL;
+	}
+
+	if ((kcmd->cmd_flags & (DMU_WRITE_ZC | DMU_READ_ZC)) &&
+	    (kcmd->cmd_flags & DMU_VERIFY)) {
+		zpios_print(file, "Invalid flags, DMU_*_ZC incompatible "
+			    "with DMU_VERIFY, used for performance analysis "
+			    "only, %d\n", -EINVAL);
+		return -EINVAL;
+	}
+
+	/* Opaque data on return contains structs of the following form:
+	 *
+	 * zpios_stat_t stats[];
+	 * stats[0]     = run_args->stats;
+	 * stats[1-N]   = threads[N]->stats;
+	 * stats[N+1-M] = regions[M]->stats;
+	 *
+	 * Where N is the number of threads, and M is the number of regions.
+	 */
+	size = (sizeof(zpios_stats_t) +
+	       (kcmd->cmd_thread_count * sizeof(zpios_stats_t)) +
+	       (kcmd->cmd_region_count * sizeof(zpios_stats_t)));
+	if (data_size < size) {
+		zpios_print(file, "Invalid size, command data buffer "
+			    "size too small, (%d < %d)\n", data_size, size);
+		return -ENOSPC;
+	}
+
+	rc = zpios_setup_run(&run_args, kcmd, file);
+	if (rc)
+		return rc;
+
+        rc = zpios_threads_run(run_args);
+	zpios_remove_objset(run_args);
+	if (rc)
+		goto cleanup;
+
+	if (stats) {
+		n = 1;
+		m = 1 + kcmd->cmd_thread_count;
+		stats[0] = run_args->stats;
+
+		for (i = 0; i < kcmd->cmd_thread_count; i++)
+			stats[n+i] = run_args->threads[i]->stats;
+
+		for (i = 0; i < kcmd->cmd_region_count; i++)
+			stats[m+i] = run_args->regions[i].stats;
+	}
+
+cleanup:
+        zpios_cleanup_run(run_args);
+
+	(void)zpios_upcall(kcmd->cmd_post, PHASE_POST_RUN, run_args, 0);
+
+	return rc;
+}
+
+static int
+zpios_open(struct inode *inode, struct file *file)
+{
+	unsigned int minor = iminor(inode);
+	zpios_info_t *info;
+
+	if (minor >= ZPIOS_MINORS)
+		return -ENXIO;
+
+	info = (zpios_info_t *)kmem_alloc(sizeof(*info), KM_SLEEP);
+	if (info == NULL)
+		return -ENOMEM;
+
+	spin_lock_init(&info->info_lock);
+	info->info_size = ZPIOS_INFO_BUFFER_SIZE;
+	info->info_buffer = (char *)vmem_alloc(ZPIOS_INFO_BUFFER_SIZE,KM_SLEEP);
+	if (info->info_buffer == NULL) {
+		kmem_free(info, sizeof(*info));
+		return -ENOMEM;
+	}
+
+	info->info_head = info->info_buffer;
+	file->private_data = (void *)info;
+
+        return 0;
+}
+
+static int
+zpios_release(struct inode *inode, struct file *file)
+{
+	unsigned int minor = iminor(inode);
+	zpios_info_t *info = (zpios_info_t *)file->private_data;
+
+	if (minor >= ZPIOS_MINORS)
+		return -ENXIO;
+
+	ASSERT(info);
+	ASSERT(info->info_buffer);
+
+	vmem_free(info->info_buffer, ZPIOS_INFO_BUFFER_SIZE);
+	kmem_free(info, sizeof(*info));
+
+	return 0;
+}
+
+static int
+zpios_buffer_clear(struct file *file, zpios_cfg_t *kcfg, unsigned long arg)
+{
+	zpios_info_t *info = (zpios_info_t *)file->private_data;
+
+	ASSERT(info);
+	ASSERT(info->info_buffer);
+
+	spin_lock(&info->info_lock);
+	memset(info->info_buffer, 0, info->info_size);
+	info->info_head = info->info_buffer;
+	spin_unlock(&info->info_lock);
+
+	return 0;
+}
+
+static int
+zpios_buffer_size(struct file *file, zpios_cfg_t *kcfg, unsigned long arg)
+{
+	zpios_info_t *info = (zpios_info_t *)file->private_data;
+	char *buf;
+	int min, size, rc = 0;
+
+	ASSERT(info);
+	ASSERT(info->info_buffer);
+
+	spin_lock(&info->info_lock);
+	if (kcfg->cfg_arg1 > 0) {
+
+		size = kcfg->cfg_arg1;
+		buf = (char *)vmem_alloc(size, KM_SLEEP);
+		if (buf == NULL) {
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		/* Zero fill and truncate contents when coping buffer */
+		min = ((size < info->info_size) ? size : info->info_size);
+		memset(buf, 0, size);
+		memcpy(buf, info->info_buffer, min);
+		vmem_free(info->info_buffer, info->info_size);
+		info->info_size = size;
+		info->info_buffer = buf;
+		info->info_head = info->info_buffer;
+	}
+
+	kcfg->cfg_rc1 = info->info_size;
+
+	if (copy_to_user((struct zpios_cfg_t __user *)arg, kcfg, sizeof(*kcfg)))
+		rc = -EFAULT;
+out:
+	spin_unlock(&info->info_lock);
+
+	return rc;
+}
+
+static int
+zpios_ioctl_cfg(struct file *file, unsigned long arg)
+{
+	zpios_cfg_t kcfg;
+	int rc = 0;
+
+	if (copy_from_user(&kcfg, (zpios_cfg_t *)arg, sizeof(kcfg)))
+		return -EFAULT;
+
+	if (kcfg.cfg_magic != ZPIOS_CFG_MAGIC) {
+		zpios_print(file, "Bad config magic 0x%x != 0x%x\n",
+		            kcfg.cfg_magic, ZPIOS_CFG_MAGIC);
+		return -EINVAL;
+	}
+
+	switch (kcfg.cfg_cmd) {
+		case ZPIOS_CFG_BUFFER_CLEAR:
+			/* cfg_arg1 - Unused
+			 * cfg_rc1  - Unused
+			 */
+			rc = zpios_buffer_clear(file, &kcfg, arg);
+			break;
+		case ZPIOS_CFG_BUFFER_SIZE:
+			/* cfg_arg1 - 0 - query size; >0 resize
+			 * cfg_rc1  - Set to current buffer size
+			 */
+			rc = zpios_buffer_size(file, &kcfg, arg);
+			break;
+		default:
+			zpios_print(file, "Bad config command %d\n",
+				    kcfg.cfg_cmd);
+			rc = -EINVAL;
+			break;
+	}
+
+	return rc;
+}
+
+static int
+zpios_ioctl_cmd(struct file *file, unsigned long arg)
+{
+	zpios_cmd_t *kcmd;
+	void *data = NULL;
+	int rc = -EINVAL;
+
+	kcmd = kmem_alloc(sizeof(zpios_cmd_t), KM_SLEEP);
+	if (kcmd == NULL) {
+		zpios_print(file, "Unable to kmem_alloc() %ld byte for "
+			    "zpios_cmd_t\n", (long int)sizeof(zpios_cmd_t));
+		return -ENOMEM;
+	}
+
+	rc = copy_from_user(kcmd, (zpios_cfg_t *)arg, sizeof(zpios_cmd_t));
+	if (rc) {
+		zpios_print(file, "Unable to copy command structure "
+			    "from user to kernel memory, %d\n", rc);
+		goto out_cmd;
+	}
+
+	if (kcmd->cmd_magic != ZPIOS_CMD_MAGIC) {
+		zpios_print(file, "Bad command magic 0x%x != 0x%x\n",
+		            kcmd->cmd_magic, ZPIOS_CFG_MAGIC);
+		rc = -EINVAL;
+		goto out_cmd;
+	}
+
+	/* Allocate memory for any opaque data the caller needed to pass on */
+	if (kcmd->cmd_data_size > 0) {
+		data = (void *)vmem_alloc(kcmd->cmd_data_size, KM_SLEEP);
+		if (data == NULL) {
+			zpios_print(file, "Unable to vmem_alloc() %ld "
+				    "bytes for data buffer\n",
+				    (long)kcmd->cmd_data_size);
+			rc = -ENOMEM;
+			goto out_cmd;
+		}
+
+		rc = copy_from_user(data, (void *)(arg + offsetof(zpios_cmd_t,
+		                    cmd_data_str)), kcmd->cmd_data_size);
+		if (rc) {
+			zpios_print(file, "Unable to copy data buffer "
+				    "from user to kernel memory, %d\n", rc);
+			goto out_data;
+		}
+	}
+
+	rc = zpios_do_one_run(file, kcmd, kcmd->cmd_data_size, data);
+
+	if (data != NULL) {
+		/* If the test failed do not print out the stats */
+		if (rc)
+			goto out_data;
+
+		rc = copy_to_user((void *)(arg + offsetof(zpios_cmd_t,
+		                  cmd_data_str)), data, kcmd->cmd_data_size);
+		if (rc) {
+			zpios_print(file, "Unable to copy data buffer "
+				    "from kernel to user memory, %d\n", rc);
+			rc = -EFAULT;
+		}
+
+out_data:
+		vmem_free(data, kcmd->cmd_data_size);
+	}
+out_cmd:
+	kmem_free(kcmd, sizeof(zpios_cmd_t));
+
+	return rc;
+}
+
+static int
+zpios_ioctl(struct inode *inode, struct file *file,
+            unsigned int cmd, unsigned long arg)
+{
+        unsigned int minor = iminor(inode);
+	int rc = 0;
+
+	/* Ignore tty ioctls */
+	if ((cmd & 0xffffff00) == ((int)'T') << 8)
+		return -ENOTTY;
+
+	if (minor >= ZPIOS_MINORS)
+		return -ENXIO;
+
+	switch (cmd) {
+		case ZPIOS_CFG:
+			rc = zpios_ioctl_cfg(file, arg);
+			break;
+		case ZPIOS_CMD:
+			rc = zpios_ioctl_cmd(file, arg);
+			break;
+		default:
+			zpios_print(file, "Bad ioctl command %d\n", cmd);
+			rc = -EINVAL;
+			break;
+	}
+
+	return rc;
+}
+
+#ifdef CONFIG_COMPAT
+/* Compatibility handler for ioctls from 32-bit ELF binaries */
+static long
+zpios_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	return zpios_ioctl(file->f_dentry->d_inode, file, cmd, arg);
+}
+#endif /* CONFIG_COMPAT */
+
+/* I'm not sure why you would want to write in to this buffer from
+ * user space since its principle use is to pass test status info
+ * back to the user space, but I don't see any reason to prevent it.
+ */
+static ssize_t
+zpios_write(struct file *file, const char __user *buf,
+            size_t count, loff_t *ppos)
+{
+        unsigned int minor = iminor(file->f_dentry->d_inode);
+	zpios_info_t *info = (zpios_info_t *)file->private_data;
+	int rc = 0;
+
+	if (minor >= ZPIOS_MINORS)
+		return -ENXIO;
+
+	ASSERT(info);
+	ASSERT(info->info_buffer);
+
+	spin_lock(&info->info_lock);
+
+	/* Write beyond EOF */
+	if (*ppos >= info->info_size) {
+		rc = -EFBIG;
+		goto out;
+	}
+
+	/* Resize count if beyond EOF */
+	if (*ppos + count > info->info_size)
+		count = info->info_size - *ppos;
+
+	if (copy_from_user(info->info_buffer, buf, count)) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	*ppos += count;
+	rc = count;
+out:
+	spin_unlock(&info->info_lock);
+	return rc;
+}
+
+static ssize_t
+zpios_read(struct file *file, char __user *buf,
+		        size_t count, loff_t *ppos)
+{
+        unsigned int minor = iminor(file->f_dentry->d_inode);
+	zpios_info_t *info = (zpios_info_t *)file->private_data;
+	int rc = 0;
+
+	if (minor >= ZPIOS_MINORS)
+		return -ENXIO;
+
+	ASSERT(info);
+	ASSERT(info->info_buffer);
+
+	spin_lock(&info->info_lock);
+
+	/* Read beyond EOF */
+	if (*ppos >= info->info_size)
+		goto out;
+
+	/* Resize count if beyond EOF */
+	if (*ppos + count > info->info_size)
+		count = info->info_size - *ppos;
+
+	if (copy_to_user(buf, info->info_buffer + *ppos, count)) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	*ppos += count;
+	rc = count;
+out:
+	spin_unlock(&info->info_lock);
+	return rc;
+}
+
+static loff_t zpios_seek(struct file *file, loff_t offset, int origin)
+{
+        unsigned int minor = iminor(file->f_dentry->d_inode);
+	zpios_info_t *info = (zpios_info_t *)file->private_data;
+	int rc = -EINVAL;
+
+	if (minor >= ZPIOS_MINORS)
+		return -ENXIO;
+
+	ASSERT(info);
+	ASSERT(info->info_buffer);
+
+	spin_lock(&info->info_lock);
+
+	switch (origin) {
+	case 0: /* SEEK_SET - No-op just do it */
+		break;
+	case 1: /* SEEK_CUR - Seek from current */
+		offset = file->f_pos + offset;
+		break;
+	case 2: /* SEEK_END - Seek from end */
+		offset = info->info_size + offset;
+		break;
+	}
+
+	if (offset >= 0) {
+		file->f_pos = offset;
+		file->f_version = 0;
+		rc = offset;
+	}
+
+	spin_unlock(&info->info_lock);
+
+	return rc;
+}
+
+static struct cdev zpios_cdev;
+static struct file_operations zpios_fops = {
+	.owner		= THIS_MODULE,
+	.open		= zpios_open,
+	.release	= zpios_release,
+	.ioctl		= zpios_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= zpios_compat_ioctl,
+#endif
+	.read		= zpios_read,
+	.write		= zpios_write,
+	.llseek		= zpios_seek,
+};
+
+static int
+zpios_init(void)
+{
+	dev_t dev;
+	int rc;
+
+	dev = MKDEV(ZPIOS_MAJOR, 0);
+	if ((rc = register_chrdev_region(dev, ZPIOS_MINORS, ZPIOS_NAME)))
+		goto error;
+
+	/* Support for registering a character driver */
+	cdev_init(&zpios_cdev, &zpios_fops);
+	zpios_cdev.owner = THIS_MODULE;
+	kobject_set_name(&zpios_cdev.kobj, ZPIOS_NAME);
+	if ((rc = cdev_add(&zpios_cdev, dev, ZPIOS_MINORS))) {
+		printk(KERN_ERR "ZPIOS: Error adding cdev, %d\n", rc);
+		kobject_put(&zpios_cdev.kobj);
+		unregister_chrdev_region(dev, ZPIOS_MINORS);
+		goto error;
+	}
+
+	/* Support for udev make driver info available in sysfs */
+	zpios_class = spl_class_create(THIS_MODULE, ZPIOS_NAME);
+	if (IS_ERR(zpios_class)) {
+		rc = PTR_ERR(zpios_class);
+		printk(KERN_ERR "ZPIOS: Error creating zpios class, %d\n", rc);
+		cdev_del(&zpios_cdev);
+		unregister_chrdev_region(dev, ZPIOS_MINORS);
+		goto error;
+	}
+
+	zpios_device = spl_device_create(zpios_class, NULL,
+					 dev, NULL, ZPIOS_NAME);
+	return 0;
+error:
+	printk(KERN_ERR "ZPIOS: Error registering zpios device, %d\n", rc);
+	return rc;
+}
+
+static int
+zpios_fini(void)
+{
+	dev_t dev = MKDEV(ZPIOS_MAJOR, 0);
+
+	spl_device_destroy(zpios_class, zpios_device, dev);
+	spl_class_destroy(zpios_class);
+	cdev_del(&zpios_cdev);
+	unregister_chrdev_region(dev, ZPIOS_MINORS);
+
+	return 0;
+}
+
+spl_module_init(zpios_init);
+spl_module_exit(zpios_fini);
+
+MODULE_AUTHOR("LLNL / Sun");
+MODULE_DESCRIPTION("Kernel PIOS implementation");
+MODULE_LICENSE("GPL");