ubd: remove the code to register as the legacy IDE driver

With the legacy IDE driver long deprecated, and modern userspace being
much more flexible about dev_t assignments there is no reason to fake
a registration as the legacy IDE driver in ubd.  This registeration
is a little problematic as it registers the same request_queue for
multiple gendisks, so just remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Link: https://lore.kernel.org/r/20210614060759.3965724-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 8e0b43cf089f4761b3defb1fb1721bd37d3c2464..f508d45f7a6903a5ca5072a8712f2fff82caaacd 100644 (file)
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -125,9 +125,7 @@ static const struct block_device_operations ubd_blops = {
 };
 
 /* Protected by ubd_lock */
-static int fake_major = UBD_MAJOR;
 static struct gendisk *ubd_gendisk[MAX_DEV];
-static struct gendisk *fake_gendisk[MAX_DEV];
 
 #ifdef CONFIG_BLK_DEV_UBD_SYNC
 #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \
@@ -197,54 +195,19 @@ struct ubd {
 /* Protected by ubd_lock */
 static struct ubd ubd_devs[MAX_DEV] = { [0 ... MAX_DEV - 1] = DEFAULT_UBD };
 
-/* Only changed by fake_ide_setup which is a setup */
-static int fake_ide = 0;
-static struct proc_dir_entry *proc_ide_root = NULL;
-static struct proc_dir_entry *proc_ide = NULL;
-
 static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx,
                                 const struct blk_mq_queue_data *bd);
 
-static void make_proc_ide(void)
-{
-       proc_ide_root = proc_mkdir("ide", NULL);
-       proc_ide = proc_mkdir("ide0", proc_ide_root);
-}
-
-static int fake_ide_media_proc_show(struct seq_file *m, void *v)
-{
-       seq_puts(m, "disk\n");
-       return 0;
-}
-
-static void make_ide_entries(const char *dev_name)
-{
-       struct proc_dir_entry *dir, *ent;
-       char name[64];
-
-       if(proc_ide_root == NULL) make_proc_ide();
-
-       dir = proc_mkdir(dev_name, proc_ide);
-       if(!dir) return;
-
-       ent = proc_create_single("media", S_IRUGO, dir,
-                       fake_ide_media_proc_show);
-       if(!ent) return;
-       snprintf(name, sizeof(name), "ide0/%s", dev_name);
-       proc_symlink(dev_name, proc_ide_root, name);
-}
-
 static int fake_ide_setup(char *str)
 {
-       fake_ide = 1;
+       pr_warn("The fake_ide option has been removed\n");
        return 1;
 }
-
 __setup("fake_ide", fake_ide_setup);
 
 __uml_help(fake_ide_setup,
 "fake_ide\n"
-"    Create ide0 entries that map onto ubd devices.\n\n"
+"    Obsolete stub.\n\n"
 );
 
 static int parse_unit(char **ptr)
@@ -296,20 +259,8 @@ static int ubd_setup_common(char *str, int *index_out, char **error_out)
                        return err;
                }
 
-               mutex_lock(&ubd_lock);
-               if (fake_major != UBD_MAJOR) {
-                       *error_out = "Can't assign a fake major twice";
-                       goto out1;
-               }
-
-               fake_major = major;
-
-               printk(KERN_INFO "Setting extra ubd major number to %d\n",
-                      major);
-               err = 0;
-       out1:
-               mutex_unlock(&ubd_lock);
-               return err;
+               pr_warn("fake major not supported any more\n");
+               return 0;
        }
 
        n = parse_unit(&str);
@@ -917,7 +868,6 @@ static const struct attribute_group *ubd_attr_groups[] = {
 static int ubd_disk_register(int major, u64 size, int unit,
                             struct gendisk **disk_out)
 {
-       struct device *parent = NULL;
        struct gendisk *disk;
 
        disk = alloc_disk(1 << UBD_SHIFT);
@@ -928,24 +878,17 @@ static int ubd_disk_register(int major, u64 size, int unit,
        disk->first_minor = unit << UBD_SHIFT;
        disk->fops = &ubd_blops;
        set_capacity(disk, size / 512);
-       if (major == UBD_MAJOR)
-               sprintf(disk->disk_name, "ubd%c", 'a' + unit);
-       else
-               sprintf(disk->disk_name, "ubd_fake%d", unit);
-
-       /* sysfs register (not for ide fake devices) */
-       if (major == UBD_MAJOR) {
-               ubd_devs[unit].pdev.id   = unit;
-               ubd_devs[unit].pdev.name = DRIVER_NAME;
-               ubd_devs[unit].pdev.dev.release = ubd_device_release;
-               dev_set_drvdata(&ubd_devs[unit].pdev.dev, &ubd_devs[unit]);
-               platform_device_register(&ubd_devs[unit].pdev);
-               parent = &ubd_devs[unit].pdev.dev;
-       }
+       sprintf(disk->disk_name, "ubd%c", 'a' + unit);
+
+       ubd_devs[unit].pdev.id   = unit;
+       ubd_devs[unit].pdev.name = DRIVER_NAME;
+       ubd_devs[unit].pdev.dev.release = ubd_device_release;
+       dev_set_drvdata(&ubd_devs[unit].pdev.dev, &ubd_devs[unit]);
+       platform_device_register(&ubd_devs[unit].pdev);
 
        disk->private_data = &ubd_devs[unit];
        disk->queue = ubd_devs[unit].queue;
-       device_add_disk(parent, disk, ubd_attr_groups);
+       device_add_disk(&ubd_devs[unit].pdev.dev, disk, ubd_attr_groups);
 
        *disk_out = disk;
        return 0;
@@ -1001,17 +944,6 @@ static int ubd_add(int n, char **error_out)
                goto out_cleanup_tags;
        }
 
-       if (fake_major != UBD_MAJOR)
-               ubd_disk_register(fake_major, ubd_dev->size, n,
-                                 &fake_gendisk[n]);
-
-       /*
-        * Perhaps this should also be under the "if (fake_major)" above
-        * using the fake_disk->disk_name
-        */
-       if (fake_ide)
-               make_ide_entries(ubd_gendisk[n]->disk_name);
-
        err = 0;
 out:
        return err;
@@ -1126,12 +1058,6 @@ static int ubd_remove(int n, char **error_out)
                put_disk(disk);
        }
 
-       if(fake_gendisk[n] != NULL){
-               del_gendisk(fake_gendisk[n]);
-               put_disk(fake_gendisk[n]);
-               fake_gendisk[n] = NULL;
-       }
-
        err = 0;
        platform_device_unregister(&ubd_dev->pdev);
 out:
@@ -1188,14 +1114,6 @@ static int __init ubd_init(void)
        if (register_blkdev(UBD_MAJOR, "ubd"))
                return -1;
 
-       if (fake_major != UBD_MAJOR) {
-               char name[sizeof("ubd_nnn\0")];
-
-               snprintf(name, sizeof(name), "ubd_%d", fake_major);
-               if (register_blkdev(fake_major, "ubd"))
-                       return -1;
-       }
-
        irq_req_buffer = kmalloc_array(UBD_REQ_BUFFER_SIZE,
                                       sizeof(struct io_thread_req *),
                                       GFP_KERNEL