Make the vfs.zfs.vdev.raidz_impl sysctl cross-platform

Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by:	Alan Somers <asomers@gmail.com>
Sponsored by:	ConnectWise
Closes openzfs#16980

Author: asomers

include/os/freebsd/spl/sys/mod_os.h

@@ -94,6 +94,9 @@
 #define	param_set_max_auto_ashift_args(var) \
     CTLTYPE_UINT, NULL, 0, param_set_max_auto_ashift, "IU"
 
+#define	param_set_raidz_impl_args(var) \
+    CTLTYPE_STRING, NULL, 0, param_set_raidz_impl, "A"
+
 #define	spa_taskq_read_param_set_args(var) \
     CTLTYPE_STRING, NULL, 0, spa_taskq_read_param, "A"
 

include/sys/vdev_impl.h

@@ -645,6 +645,10 @@ extern int vdev_obsolete_counts_are_precise(vdev_t *vd, boolean_t *are_precise);
 int vdev_checkpoint_sm_object(vdev_t *vd, uint64_t *sm_obj);
 void vdev_metaslab_group_create(vdev_t *vd);
 uint64_t vdev_best_ashift(uint64_t logical, uint64_t a, uint64_t b);
+#if defined(__linux__)
+int param_get_raidz_impl(char *buf, zfs_kernel_param_t *kp);
+#endif
+int param_set_raidz_impl(ZFS_MODULE_PARAM_ARGS);
 
 /*
  * Vdev ashift optimization tunables

include/sys/vdev_raidz.h

@@ -66,13 +66,16 @@ extern const zio_vsd_ops_t vdev_raidz_vsd_ops;
 /*
  * vdev_raidz_math interface
  */
+/* Required, but not used, by ZFS_MODULE_PARAM_CALL */
+extern uint32_t zfs_vdev_raidz_impl;
 void vdev_raidz_math_init(void);
 void vdev_raidz_math_fini(void);
 const struct raidz_impl_ops *vdev_raidz_math_get_ops(void);
 int vdev_raidz_math_generate(struct raidz_map *, struct raidz_row *);
 int vdev_raidz_math_reconstruct(struct raidz_map *, struct raidz_row *,
     const int *, const int *, const int);
 int vdev_raidz_impl_set(const char *);
+int vdev_raidz_impl_get(char *buffer, size_t size);
 
 typedef struct vdev_raidz_expand {
 	uint64_t vre_vdev_id;

module/Kbuild.in

@@ -447,6 +447,7 @@ ZFS_OBJS_OS := \
 	trace.o \
 	vdev_disk.o \
 	vdev_file.o \
+	vdev_raidz.o \
 	vdev_label_os.o \
 	zfs_acl.o \
 	zfs_ctldir.o \

module/os/freebsd/zfs/sysctl_os.c

@@ -679,6 +679,27 @@ param_set_deadman_failmode(SYSCTL_HANDLER_ARGS)
 	return (-param_set_deadman_failmode_common(buf));
 }
 
+int
+param_set_raidz_impl(SYSCTL_HANDLER_ARGS)
+{
+	const size_t bufsize = 128;
+	char *buf;
+	int rc;
+
+	buf = malloc(bufsize, M_SOLARIS, M_WAITOK | M_ZERO);
+	if (req->newptr == NULL)
+		vdev_raidz_impl_get(buf, bufsize);
+
+	rc = sysctl_handle_string(oidp, buf, bufsize, req);
+	if (rc || req->newptr == NULL) {
+		free(buf, M_SOLARIS);
+		return (rc);
+	}
+	rc = vdev_raidz_impl_set(buf);
+	free(buf, M_SOLARIS);
+	return (rc);
+}
+
 int
 param_set_slop_shift(SYSCTL_HANDLER_ARGS)
 {

module/os/linux/zfs/vdev_raidz.c

@@ -0,0 +1,42 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * 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/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * 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/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 (C) 2025 ConnectWise */
+
+#include <sys/zfs_context.h>
+#include <sys/spa.h>
+#include <sys/zio.h>
+#include <sys/vdev_impl.h>
+#include <sys/vdev_raidz.h>
+
+int
+param_get_raidz_impl(char *buf, zfs_kernel_param_t *kp)
+{
+	return (vdev_raidz_impl_get(buf, PAGE_SIZE));
+}
+
+int
+param_set_raidz_impl(const char *val, zfs_kernel_param_t *kp)
+{
+	int error;
+
+	error = vdev_raidz_impl_set(val);
+	return (error);
+}

module/zfs/vdev.c

@@ -6598,3 +6598,7 @@ ZFS_MODULE_PARAM_CALL(zfs_vdev, zfs_vdev_, max_auto_ashift,
 	param_set_max_auto_ashift, param_get_uint, ZMOD_RW,
 	"Maximum ashift used when optimizing for logical -> physical sector "
 	"size on new top-level vdevs");
+
+ZFS_MODULE_PARAM_CALL(zfs_vdev, zfs_vdev_, raidz_impl,
+		param_set_raidz_impl, param_get_raidz_impl, ZMOD_RW,
+		"RAIDZ implementation");

module/zfs/vdev_raidz_math.c

@@ -81,7 +81,7 @@ static boolean_t raidz_math_initialized = B_FALSE;
 
 #define	RAIDZ_IMPL_READ(i)	(*(volatile uint32_t *) &(i))
 
-static uint32_t zfs_vdev_raidz_impl = IMPL_SCALAR;
+uint32_t zfs_vdev_raidz_impl = IMPL_SCALAR;
 static uint32_t user_sel_impl = IMPL_FASTEST;
 
 /* Hold all supported implementations */
@@ -634,16 +634,8 @@ vdev_raidz_impl_set(const char *val)
 }
 
 #if defined(_KERNEL)
-#if defined(__linux__) || defined(_WIN32)
-
-static int
-zfs_vdev_raidz_impl_set(const char *val, zfs_kernel_param_t *kp)
-{
-	return (vdev_raidz_impl_set(val));
-}
-
-static int
-zfs_vdev_raidz_impl_get(char *buffer, zfs_kernel_param_t *kp)
+int
+vdev_raidz_impl_get(char *buffer, size_t size)
 {
 	int i, cnt = 0;
 	char *fmt;
@@ -654,20 +646,19 @@ zfs_vdev_raidz_impl_get(char *buffer, zfs_kernel_param_t *kp)
 	/* list mandatory options */
 	for (i = 0; i < ARRAY_SIZE(math_impl_opts) - 2; i++) {
 		fmt = (impl == math_impl_opts[i].sel) ? "[%s] " : "%s ";
-		cnt += kmem_scnprintf(buffer + cnt, PAGE_SIZE - cnt, fmt,
+		cnt += kmem_scnprintf(buffer + cnt, size - cnt, fmt,
 		    math_impl_opts[i].name);
 	}
 
 	/* list all supported implementations */
 	for (i = 0; i < raidz_supp_impl_cnt; i++) {
 		fmt = (i == impl) ? "[%s] " : "%s ";
-		cnt += kmem_scnprintf(buffer + cnt, PAGE_SIZE - cnt, fmt,
+		cnt += kmem_scnprintf(buffer + cnt, size - cnt, fmt,
 		    raidz_supp_impl[i]->name);
 	}
 
 	return (cnt);
 }
-#endif /* Linux || Windows */
 
 #ifdef _WIN32
 int
@@ -693,7 +684,4 @@ win32_zfs_vdev_raidz_impl_set(ZFS_MODULE_PARAM_ARGS)
 }
 #endif
 
-module_param_call(zfs_vdev_raidz_impl, zfs_vdev_raidz_impl_set,
-    zfs_vdev_raidz_impl_get, NULL, 0644);
-MODULE_PARM_DESC(zfs_vdev_raidz_impl, "Select raidz implementation.");
 #endif