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Commit 4bcce1a3 authored by Ed L. Cashin's avatar Ed L. Cashin Committed by Linus Torvalds
Browse files

aoe: retain static block device numbers for backwards compatibility 



The old mapping between AoE target shelf and slot addresses and the block
device minor number is retained as a backwards-compatible feature, with a
new "aoe_dyndevs" module parameter available for enabling dynamic block
device minor numbers.

Signed-off-by: default avatarEd Cashin <ecashin@coraid.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0c966214

drivers/block/aoe/aoedev.c

+51 −3
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/slab.h>

#include <linux/bitmap.h>

#include <linux/kdev_t.h>

#include <linux/moduleparam.h>

#include "aoe.h"



static void dummy_timer(ulong);
@@ -18,6 +19,10 @@ static void aoedev_freedev(struct aoedev *); 
static void freetgt(struct aoedev *d, struct aoetgt *t);

static void skbpoolfree(struct aoedev *d);



static int aoe_dyndevs;

module_param(aoe_dyndevs, int, 0644);

MODULE_PARM_DESC(aoe_dyndevs, "Use dynamic minor numbers for devices.");



static struct aoedev *devlist;

static DEFINE_SPINLOCK(devlist_lock);
@@ -34,7 +39,7 @@ static DEFINE_SPINLOCK(used_minors_lock); 
static DECLARE_BITMAP(used_minors, N_DEVS);



static int

minor_get(ulong *minor)

minor_get_dyn(ulong *sysminor)

{

	ulong flags;

	ulong n;
@@ -48,10 +53,53 @@ minor_get(ulong *minor) 
		error = -1;

	spin_unlock_irqrestore(&used_minors_lock, flags);



	*minor = n * AOE_PARTITIONS;

	*sysminor = n * AOE_PARTITIONS;

	return error;

}



static int

minor_get_static(ulong *sysminor, ulong aoemaj, int aoemin)

{

	ulong flags;

	ulong n;

	int error = 0;

	enum {

		/* for backwards compatibility when !aoe_dyndevs,

		 * a static number of supported slots per shelf */

		NPERSHELF = 16,

	};



	n = aoemaj * NPERSHELF + aoemin;

	if (aoemin >= NPERSHELF || n >= N_DEVS) {

		pr_err("aoe: %s with e%ld.%d\n",

			"cannot use static minor device numbers",

			aoemaj, aoemin);

		error = -1;

	} else {

		spin_lock_irqsave(&used_minors_lock, flags);

		if (test_bit(n, used_minors)) {

			pr_err("aoe: %s %lu\n",

				"existing device already has static minor number",

				n);

			error = -1;

		} else

			set_bit(n, used_minors);

		spin_unlock_irqrestore(&used_minors_lock, flags);

	}



	*sysminor = n;

	return error;

}



static int

minor_get(ulong *sysminor, ulong aoemaj, int aoemin)

{

	if (aoe_dyndevs)

		return minor_get_dyn(sysminor);

	else

		return minor_get_static(sysminor, aoemaj, aoemin);

}



static void

minor_free(ulong minor)

{
@@ -293,7 +341,7 @@ aoedev_by_aoeaddr(ulong maj, int min, int do_alloc) 
			d->ref++;

			break;

		}

	if (d || !do_alloc || minor_get(&sysminor) < 0)

	if (d || !do_alloc || minor_get(&sysminor, maj, min) < 0)

		goto out;

	d = kcalloc(1, sizeof *d, GFP_ATOMIC);

	if (!d)