From 35be05171dcce5e35b9db880f7f00a74b2de9895 Mon Sep 17 00:00:00 2001
From: Shashank Kumar <75466339+datacore-skumar@users.noreply.github.com>
Date: Fri, 18 Mar 2022 15:21:18 +0530
Subject: [PATCH] IOCTL to fetch IOPS and read/write bytes of a zpool

---
 include/os/windows/zfs/sys/zfs_windows.h  |  2 ++
 include/sys/zfs_ioctl.h                   |  3 ++
 module/os/windows/zfs/zfs_ioctl_os.c      | 41 +++++++++++++++++++++++
 module/os/windows/zfs/zfs_vnops_windows.c |  4 +++
 4 files changed, 50 insertions(+)

diff --git a/include/os/windows/zfs/sys/zfs_windows.h b/include/os/windows/zfs/sys/zfs_windows.h
index ddc3f28c6361..ec416dd38d76 100644
--- a/include/os/windows/zfs/sys/zfs_windows.h
+++ b/include/os/windows/zfs/sys/zfs_windows.h
@@ -186,5 +186,7 @@ extern NTSTATUS ioctl_query_stable_guid(PDEVICE_OBJECT, PIRP,
     PIO_STACK_LOCATION);
 extern NTSTATUS zpool_get_size_stats(PDEVICE_OBJECT DeviceObject, PIRP Irp,
     PIO_STACK_LOCATION IrpSp);
+extern NTSTATUS zpool_get_iops_thrput(PDEVICE_OBJECT DeviceObject, PIRP Irp,
+    PIO_STACK_LOCATION IrpSp);
 
 #endif
diff --git a/include/sys/zfs_ioctl.h b/include/sys/zfs_ioctl.h
index e5db57e39ba1..1a83506b4c16 100644
--- a/include/sys/zfs_ioctl.h
+++ b/include/sys/zfs_ioctl.h
@@ -536,6 +536,8 @@ typedef struct {
 	uint64_t alloc;
 } zpool_size_stats;
 
+#define ZPOOL_GET_IOPS_THRPUT_STATS	CTL_CODE(ZFSIOCTL_TYPE, 0xFFE, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
 typedef struct
 {
     uint64_t total;
@@ -577,6 +579,7 @@ typedef struct {
     unsigned __int64	vsx_disk_histo_write_time;
     unsigned __int64	vsx_disk_histo_write_count;
     unsigned __int64	dp_dirty_total_io;	// zpool only
+    char zpool_name[MAXNAMELEN];
 } zpool_perf_counters;
 
 typedef struct {
diff --git a/module/os/windows/zfs/zfs_ioctl_os.c b/module/os/windows/zfs/zfs_ioctl_os.c
index f09445dec67a..2fe118d8ff97 100644
--- a/module/os/windows/zfs/zfs_ioctl_os.c
+++ b/module/os/windows/zfs/zfs_ioctl_os.c
@@ -88,6 +88,47 @@ zfs_vfs_ref(zfsvfs_t **zfvp)
 	return (error);
 }
 
+NTSTATUS zpool_get_iops_thrput(PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
+{
+    if (IrpSp->Parameters.DeviceIoControl.OutputBufferLength < sizeof(zpool_perf_counters)) {
+	Irp->IoStatus.Information = sizeof(zpool_perf_counters);
+	return STATUS_BUFFER_TOO_SMALL;
+    }
+
+    zpool_perf_counters* perf = (zpool_perf_counters*)Irp->AssociatedIrp.SystemBuffer;
+    if (!perf)
+	return STATUS_INVALID_PARAMETER;
+
+    perf->zpool_name[MAXNAMELEN - 1] = '\0';
+
+    // If 'zpool/zvol' name is provided, truncating it to zpool name only
+    char* slash = strchr(perf->zpool_name, '/');
+    if (slash)
+	*slash = '\0';
+
+    mutex_enter(&spa_namespace_lock);
+    spa_t* spa;
+    if ((spa = spa_lookup(perf->zpool_name)) == NULL) {
+	mutex_exit(&spa_namespace_lock);
+	return STATUS_NOT_FOUND;
+    }
+    vdev_stat_t vs;
+    spa_config_enter(spa, SCL_ALL, FTAG, RW_READER);
+    vdev_get_stats(spa->spa_root_vdev, &vs);
+    spa_config_exit(spa, SCL_ALL, FTAG);
+    mutex_exit(&spa_namespace_lock);
+
+    perf->read_iops = vs.vs_ops[ZIO_TYPE_READ];
+    perf->write_iops = vs.vs_ops[ZIO_TYPE_WRITE];
+    perf->read_bytes = vs.vs_bytes[ZIO_TYPE_READ] / (1024 * 1024);
+    perf->write_bytes = vs.vs_bytes[ZIO_TYPE_WRITE] / (1024 * 1024);
+    perf->total_iops = vs.vs_ops[ZIO_TYPE_READ] + vs.vs_ops[ZIO_TYPE_WRITE];
+    perf->total_bytes = (vs.vs_bytes[ZIO_TYPE_READ] + vs.vs_bytes[ZIO_TYPE_WRITE]) / (1024 * 1024);
+
+    Irp->IoStatus.Information = sizeof(zpool_perf_counters);
+    return STATUS_SUCCESS;
+}
+
 NTSTATUS NTAPI
 ZFSinPerfCallBack(PCW_CALLBACK_TYPE Type, PPCW_CALLBACK_INFORMATION Info,
     PVOID Context)
diff --git a/module/os/windows/zfs/zfs_vnops_windows.c b/module/os/windows/zfs/zfs_vnops_windows.c
index 10ea683defe2..d5cd1f2e7d97 100644
--- a/module/os/windows/zfs/zfs_vnops_windows.c
+++ b/module/os/windows/zfs/zfs_vnops_windows.c
@@ -4660,6 +4660,10 @@ _Function_class_(DRIVER_DISPATCH)
 				Status = zpool_get_size_stats(DeviceObject,
 				    Irp, IrpSp);
 				break;
+			case ZPOOL_GET_IOPS_THRPUT_STATS:
+			    dprintf("ZPOOL_GET_IOPS_THRPUT_STATS\n");
+			    Status = zpool_get_iops_thrput(DeviceObject, Irp, IrpSp);
+			    break;
 			default:
 				dprintf("**** unknown Windows IOCTL: 0x%lx\n",
 				    cmd);