vdev_disk: remove zfs_vdev_scheduler option

It has existed as a warning since 0.8.3, 5+ years ago. I think people
have had enough time.

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Alexander Motin <[email protected]>
Reviewed-by: George Melikov <[email protected]>
Reviewed-by: Pavel Snajdr <[email protected]>
Signed-off-by: Rob Norris <[email protected]>
Closes #17376

Author: robn

man/man4/zfs.4

@@ -2411,10 +2411,6 @@ aarch64_neonx2	NEON with more unrolling	Aarch64/64-bit ARMv8
 powerpc_altivec	Altivec	PowerPC
 .TE
 .
-.It Sy zfs_vdev_scheduler Pq charp
-.Sy DEPRECATED .
-Prints warning to kernel log for compatibility.
-.
 .It Sy zfs_zevent_len_max Ns = Ns Sy 512 Pq uint
 Max event queue length.
 Events in the queue can be viewed with

module/os/linux/zfs/vdev_disk.c

@@ -1576,29 +1576,6 @@ vdev_ops_t vdev_disk_ops = {
 	.vdev_op_kobj_evt_post = vdev_disk_kobj_evt_post
 };
 
-/*
- * The zfs_vdev_scheduler module option has been deprecated. Setting this
- * value no longer has any effect.  It has not yet been entirely removed
- * to allow the module to be loaded if this option is specified in the
- * /etc/modprobe.d/zfs.conf file.  The following warning will be logged.
- */
-static int
-param_set_vdev_scheduler(const char *val, zfs_kernel_param_t *kp)
-{
-	int error = param_set_charp(val, kp);
-	if (error == 0) {
-		printk(KERN_INFO "The 'zfs_vdev_scheduler' module option "
-		    "is not supported.\n");
-	}
-
-	return (error);
-}
-
-static const char *zfs_vdev_scheduler = "unused";
-module_param_call(zfs_vdev_scheduler, param_set_vdev_scheduler,
-    param_get_charp, &zfs_vdev_scheduler, 0644);
-MODULE_PARM_DESC(zfs_vdev_scheduler, "I/O scheduler");
-
 int
 param_set_min_auto_ashift(const char *buf, zfs_kernel_param_t *kp)
 {