Attachment 312458 Details for Bug 455756 – Expand RHEL-4 blkfront to support > 16 xvd devices

[patch] Expand RHEL-4 blkfront to support > 16 xvd devices

linux-2.6.9-xen-expand-xvd-blkfront.patch (text/plain), 5.81 KB, created by Chris Lalancette on 2008-07-23 10:12:42 UTC

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Creator: Chris Lalancette

Created: 2008-07-23 10:12:42 UTC

Size: 5.81 KB

patch

obsolete

>diff -urp linux-2.6.9.patch1/drivers/xen/blkfront/blkfront.c linux-2.6.9/drivers/xen/blkfront/blkfront.c
>--- linux-2.6.9.patch1/drivers/xen/blkfront/blkfront.c	2008-07-14 22:02:39.000000000 +0200
>+++ linux-2.6.9/drivers/xen/blkfront/blkfront.c	2008-07-14 22:05:03.000000000 +0200
>@@ -91,8 +91,13 @@ static int blkfront_probe(struct xenbus_
> 	err = xenbus_scanf(XBT_NIL, dev->nodename,
> 			   "virtual-device", "%i", &vdevice);
> 	if (err != 1) {
>-		xenbus_dev_fatal(dev, err, "reading virtual-device");
>-		return err;
>+		/* go looking in the extended area instead */
>+		err = xenbus_scanf(XBT_NIL, dev->nodename,
>+				   "virtual-device-ext", "%i", &vdevice);
>+		if (err != 1) {
>+			xenbus_dev_fatal(dev, err, "reading virtual-device");
>+			return err;
>+		}
> 	}
> 
> 	info = kzalloc(sizeof(*info), GFP_KERNEL);
>diff -urp linux-2.6.9.patch1/drivers/xen/blkfront/vbd.c linux-2.6.9/drivers/xen/blkfront/vbd.c
>--- linux-2.6.9.patch1/drivers/xen/blkfront/vbd.c	2008-07-14 22:00:57.000000000 +0200
>+++ linux-2.6.9/drivers/xen/blkfront/vbd.c	2008-07-14 22:32:30.000000000 +0200
>@@ -39,6 +39,11 @@
> #define BLKIF_MAJOR(dev) ((dev)>>8)
> #define BLKIF_MINOR(dev) ((dev) & 0xff)
> 
>+#define EXT_SHIFT 28
>+#define EXTENDED (1<<EXT_SHIFT)
>+#define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED))
>+#define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED))
>+
> #ifdef HAVE_XEN_PLATFORM_COMPAT_H
> #include <xen/platform-compat.h>
> #endif
>@@ -51,7 +56,7 @@
> 
> #define NUM_IDE_MAJORS 10
> #define NUM_SCSI_MAJORS 17
>-#define NUM_VBD_MAJORS 1
>+#define NUM_VBD_MAJORS 2
> 
> static struct xlbd_type_info xlbd_ide_type = {
> 	.partn_shift = 6,
>@@ -74,6 +79,13 @@ static struct xlbd_type_info xlbd_vbd_ty
> 	.diskname = "xvd",
> };
> 
>+static struct xlbd_type_info xlbd_vbd_type_ext = {
>+	.partn_shift = 8,
>+	.disks_per_major = 256,
>+	.devname = "xvd",
>+	.diskname = "xvd",
>+};
>+
> static struct xlbd_major_info *major_info[NUM_IDE_MAJORS + NUM_SCSI_MAJORS +
> 					 NUM_VBD_MAJORS];
> 
>@@ -85,10 +97,6 @@ static struct xlbd_major_info *major_inf
> #define XLBD_MAJOR_SCSI_RANGE	XLBD_MAJOR_SCSI_START ... XLBD_MAJOR_VBD_START - 1
> #define XLBD_MAJOR_VBD_RANGE	XLBD_MAJOR_VBD_START ... XLBD_MAJOR_VBD_START + NUM_VBD_MAJORS - 1
> 
>-/* Information about our VBDs. */
>-#define MAX_VBDS 64
>-static LIST_HEAD(vbds_list);
>-
> static struct block_device_operations xlvbd_block_fops =
> {
> 	.owner = THIS_MODULE,
>@@ -104,6 +112,7 @@ static struct xlbd_major_info *
> xlbd_alloc_major_info(int major, int minor, int index)
> {
> 	struct xlbd_major_info *ptr;
>+	int do_register;
> 
> 	ptr = kzalloc(sizeof(struct xlbd_major_info), GFP_KERNEL);
> 	if (ptr == NULL)
>@@ -121,33 +130,41 @@ xlbd_alloc_major_info(int major, int min
> 		ptr->index = index - XLBD_MAJOR_SCSI_START;
> 		break;
> 	case XLBD_MAJOR_VBD_RANGE:
>-		ptr->type = &xlbd_vbd_type;
>-		ptr->index = index - XLBD_MAJOR_VBD_START;
>+		ptr->index = 0;
>+		if ((index - XLBD_MAJOR_VBD_START) == 0)
>+			ptr->type = &xlbd_vbd_type;
>+		else
>+			ptr->type = &xlbd_vbd_type_ext;
>+
>+		/* 
>+		 * if someone already registered block major 202,
>+		 * don't try to register it again
>+		 */
>+		if (major_info[XLBD_MAJOR_VBD_START] != NULL)
>+			do_register = 0;
> 		break;
> 	}
> 
>-	printk("Registering block device major %i\n", ptr->major);
>-	if (register_blkdev(ptr->major, ptr->type->devname)) {
>-		WPRINTK("can't get major %d with name %s\n",
>-			ptr->major, ptr->type->devname);
>-		kfree(ptr);
>-		return NULL;
>+	if (do_register) {
>+		printk("Registering block device major %i\n", ptr->major);
>+		if (register_blkdev(ptr->major, ptr->type->devname)) {
>+			WPRINTK("can't get major %d with name %s\n",
>+				ptr->major, ptr->type->devname);
>+			kfree(ptr);
>+			return NULL;
>+		}
> 	}
> 
>-	devfs_mk_dir(ptr->type->devname);
> 	printk("xen-vbd: registered block device major %i\n", ptr->major);
> 	major_info[index] = ptr;
> 	return ptr;
> }
> 
> static struct xlbd_major_info *
>-xlbd_get_major_info(int vdevice)
>+xlbd_get_major_info(int major, int minor, int vdevice)
> {
> 	struct xlbd_major_info *mi;
>-	int major, minor, index;
>-
>-	major = BLKIF_MAJOR(vdevice);
>-	minor = BLKIF_MINOR(vdevice);
>+	int index;
> 
> 	switch (major) {
> 	case IDE0_MAJOR: index = 0; break;
>@@ -168,7 +185,12 @@ xlbd_get_major_info(int vdevice)
> 		index = 18 + major - SCSI_DISK8_MAJOR;
> 		break;
> 	case SCSI_CDROM_MAJOR: index = 26; break;
>-	default: index = 27; break;
>+	default:
>+		if (!VDEV_IS_EXTENDED(vdevice))
>+			index = 27;
>+		else
>+			index = 28;
>+		break;
> 	}
> 
> 	mi = ((major_info[index] != NULL) ? major_info[index] :
>@@ -217,7 +239,7 @@ xlvbd_init_blk_queue(struct gendisk *gd,
> }
> 
> static int
>-xlvbd_alloc_gendisk(int minor, blkif_sector_t capacity, int vdevice,
>+xlvbd_alloc_gendisk(int major, int minor, blkif_sector_t capacity, int vdevice,
> 		    u16 vdisk_info, u16 sector_size,
> 		    struct blkfront_info *info)
> {
>@@ -231,7 +253,7 @@ xlvbd_alloc_gendisk(int minor, blkif_sec
> 	BUG_ON(info->mi != NULL);
> 	BUG_ON(info->rq != NULL);
> 
>-	mi = xlbd_get_major_info(vdevice);
>+	mi = xlbd_get_major_info(major, minor, vdevice);
> 	if (mi == NULL)
> 		goto out;
> 	info->mi = mi;
>@@ -308,15 +330,30 @@ xlvbd_add(blkif_sector_t capacity, int v
> {
> 	struct block_device *bd;
> 	int err = 0;
>+	int major, minor;
> 
>-	info->dev = MKDEV(BLKIF_MAJOR(vdevice), BLKIF_MINOR(vdevice));
>+	if ((vdevice>>EXT_SHIFT) > 1) {
>+		/* this is above the extended range; something is wrong */
>+		printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", vdevice);
>+		return -ENODEV;
>+	}
>+
>+	if (!VDEV_IS_EXTENDED(vdevice)) {
>+		major = BLKIF_MAJOR(vdevice);
>+		minor = BLKIF_MINOR(vdevice);
>+	}
>+	else {
>+		major = 202;
>+		minor = BLKIF_MINOR_EXT(vdevice);
>+	}
> 
>+	info->dev = MKDEV(major, minor);
> 	bd = bdget(info->dev);
> 	if (bd == NULL)
> 		return -ENODEV;
> 
>-	err = xlvbd_alloc_gendisk(BLKIF_MINOR(vdevice), capacity, vdevice,
>-				  vdisk_info, sector_size, info);
>+	err = xlvbd_alloc_gendisk(major, minor, capacity, vdevice, vdisk_info,
>+				  sector_size, info);
> 
> 	bdput(bd);
> 	return err;

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Attachments on bug 455756: 312457 | 312458