ZVOL: Make zvol_inhibit_dev module parameter platform-independent

The module parameter now is represented in FreeBSD sysctls list with
name: 'vfs.zfs.vol.inhibit_dev'. The default value is '0', same as on
Linux side.

Sponsored-by: vStack, Inc.
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Alexander Motin <[email protected]>
Reviewed-by: Rob Norris <[email protected]>
Signed-off-by: Fedor Uporov <[email protected]>
Closes #17384

Author: fuporovvStack

include/os/linux/kernel/linux/mod_compat.h

@@ -63,6 +63,7 @@ enum scope_prefix_types {
 	zfs_vdev_disk,
 	zfs_vdev_file,
 	zfs_vdev_mirror,
+	zfs_vol,
 	zfs_vnops,
 	zfs_zevent,
 	zfs_zio,

module/os/freebsd/zfs/zvol_os.c

@@ -1373,6 +1373,9 @@ zvol_os_create_minor(const char *name)
 	int error;
 	bool replayed_zil = B_FALSE;
 
+	if (zvol_inhibit_dev)
+		return (0);
+
 	ZFS_LOG(1, "Creating ZVOL %s...", name);
 	hash = zvol_name_hash(name);
 	if ((zv = zvol_find_by_name_hash(name, hash, RW_NONE)) != NULL) {

module/os/linux/zfs/zvol_os.c

@@ -1788,9 +1788,6 @@ zvol_fini(void)
 	ida_destroy(&zvol_ida);
 }
 
-module_param(zvol_inhibit_dev, uint, 0644);
-MODULE_PARM_DESC(zvol_inhibit_dev, "Do not create zvol device nodes");
-
 module_param(zvol_major, uint, 0444);
 MODULE_PARM_DESC(zvol_major, "Major number for zvol device");
 

module/zfs/zvol.c

@@ -2154,6 +2154,8 @@ zvol_fini_impl(void)
 	}
 }
 
+ZFS_MODULE_PARAM(zfs_vol, zvol_, inhibit_dev, UINT, ZMOD_RW,
+	"Do not create zvol device nodes");
 ZFS_MODULE_PARAM(zfs, , zvol_threads, UINT, ZMOD_RW,
 	"Number of threads for I/O requests. Set to 0 to use all active CPUs");
 ZFS_MODULE_PARAM(zfs, , zvol_num_taskqs, UINT, ZMOD_RW,

tests/zfs-tests/include/tunables.cfg

@@ -99,7 +99,7 @@ VDEV_MAX_AUTO_ASHIFT		vdev.max_auto_ashift		zfs_vdev_max_auto_ashift
 VDEV_MIN_MS_COUNT		vdev.min_ms_count		zfs_vdev_min_ms_count
 VDEV_DIRECT_WR_VERIFY		vdev.direct_write_verify	zfs_vdev_direct_write_verify
 VDEV_VALIDATE_SKIP		vdev.validate_skip		vdev_validate_skip
-VOL_INHIBIT_DEV			UNSUPPORTED			zvol_inhibit_dev
+VOL_INHIBIT_DEV			vol.inhibit_dev			zvol_inhibit_dev
 VOL_MODE			vol.mode			zvol_volmode
 VOL_RECURSIVE			vol.recursive			UNSUPPORTED
 VOL_REQUEST_SYNC		zvol_request_sync		zvol_request_sync

tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_volmode.ksh

@@ -42,7 +42,7 @@
 # 5. Verify "volmode=default" behaves accordingly to "volmode" module parameter
 # 6. Verify "volmode" property is inherited correctly
 # 7. Verify "volmode" behaves correctly at import time
-# 8. Verify "volmode" behaves accordingly to zvol_inhibit_dev (Linux only)
+# 8. Verify "volmode" behaves accordingly to zvol_inhibit_dev
 #
 
 verify_runnable "global"
@@ -64,10 +64,8 @@ function sysctl_inhibit_dev # value
 {
 	typeset value="$1"
 
-	if is_linux; then
-		log_note "Setting zvol_inhibit_dev tunable to $value"
-		log_must set_tunable32 VOL_INHIBIT_DEV $value
-	fi
+	log_note "Setting zvol_inhibit_dev tunable to $value"
+	log_must set_tunable32 VOL_INHIBIT_DEV $value
 }
 
 #
@@ -230,31 +228,29 @@ log_must_busy zfs destroy $SUBZVOL
 blockdev_missing $ZDEV
 blockdev_missing $SUBZDEV
 
-# 8. Verify "volmode" behaves accordingly to zvol_inhibit_dev (Linux only)
-if is_linux; then
-	sysctl_inhibit_dev 1
-	# 7.1 Verify device nodes not are not created with "volmode=full"
-	sysctl_volmode 1
-	log_must zfs create -V $VOLSIZE -s $ZVOL
-	blockdev_missing $ZDEV
-	set_volmode full $ZVOL
-	blockdev_missing $ZDEV
-	log_must_busy zfs destroy $ZVOL
-	blockdev_missing $ZDEV
-	# 7.1 Verify device nodes not are not created with "volmode=dev"
-	sysctl_volmode 2
-	log_must zfs create -V $VOLSIZE -s $ZVOL
-	blockdev_missing $ZDEV
-	set_volmode dev $ZVOL
-	blockdev_missing $ZDEV
-	log_must_busy zfs destroy $ZVOL
-	blockdev_missing $ZDEV
-	# 7.1 Verify device nodes not are not created with "volmode=none"
-	sysctl_volmode 3
-	log_must zfs create -V $VOLSIZE -s $ZVOL
-	blockdev_missing $ZDEV
-	set_volmode none $ZVOL
-	blockdev_missing $ZDEV
-fi
+# 8. Verify "volmode" behaves accordingly to zvol_inhibit_dev
+sysctl_inhibit_dev 1
+# 7.1 Verify device nodes not are not created with "volmode=full"
+sysctl_volmode 1
+log_must zfs create -V $VOLSIZE -s $ZVOL
+blockdev_missing $ZDEV
+set_volmode full $ZVOL
+blockdev_missing $ZDEV
+log_must_busy zfs destroy $ZVOL
+blockdev_missing $ZDEV
+# 7.1 Verify device nodes not are not created with "volmode=dev"
+sysctl_volmode 2
+log_must zfs create -V $VOLSIZE -s $ZVOL
+blockdev_missing $ZDEV
+set_volmode dev $ZVOL
+blockdev_missing $ZDEV
+log_must_busy zfs destroy $ZVOL
+blockdev_missing $ZDEV
+# 7.1 Verify device nodes not are not created with "volmode=none"
+sysctl_volmode 3
+log_must zfs create -V $VOLSIZE -s $ZVOL
+blockdev_missing $ZDEV
+set_volmode none $ZVOL
+blockdev_missing $ZDEV
 
 log_pass "Verify that ZFS volume property 'volmode' works as intended"