Commit 0c966214 authored by Ed Cashin's avatar Ed Cashin Committed by Linus Torvalds
Browse files

aoe: support more AoE addresses with dynamic block device minor numbers 



The ATA over Ethernet protocol uses a major (shelf) and minor (slot)
address to identify a particular storage target.  These changes remove an
artificial limitation the aoe driver imposes on the use of AoE addresses.
For example, without these changes, the slot address has a maximum of 15,
but users commonly use slot numbers much greater than that.

The AoE shelf and slot address space is often used sparsely.  Instead of
using a static mapping between AoE addresses and the block device minor
number, the block device minor numbers are now allocated on demand.

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 eecdf226

drivers/block/aoe/aoe.h

+3 −3
Original line number Diff line number Diff line
@@ -49,6 +49,8 @@ struct aoe_hdr { 
	__be32 tag;

};



#define AOE_MAXSHELF (0xffff-1)	/* one less than the broadcast shelf address */



struct aoe_atahdr {

	unsigned char aflags;

	unsigned char errfeat;
@@ -211,8 +213,7 @@ void aoe_ktstop(struct ktstate *k); 


int aoedev_init(void);

void aoedev_exit(void);

struct aoedev *aoedev_by_aoeaddr(int maj, int min);

struct aoedev *aoedev_by_sysminor_m(ulong sysminor);

struct aoedev *aoedev_by_aoeaddr(ulong maj, int min, int do_alloc);

void aoedev_downdev(struct aoedev *d);

int aoedev_flush(const char __user *str, size_t size);

void aoe_failbuf(struct aoedev *, struct buf *);
@@ -223,4 +224,3 @@ void aoenet_exit(void); 
void aoenet_xmit(struct sk_buff_head *);

int is_aoe_netif(struct net_device *ifp);

int set_aoe_iflist(const char __user *str, size_t size);

drivers/block/aoe/aoeblk.c

+1 −1
Original line number Diff line number Diff line
@@ -249,7 +249,7 @@ aoeblk_gdalloc(void *vp) 
	q->queuedata = d;

	d->gd = gd;

	gd->major = AOE_MAJOR;

	gd->first_minor = d->sysminor * AOE_PARTITIONS;

	gd->first_minor = d->sysminor;

	gd->fops = &aoe_bdops;

	gd->private_data = d;

	set_capacity(gd, d->ssize);

drivers/block/aoe/aoechr.c

+1 −1
Original line number Diff line number Diff line
@@ -91,7 +91,7 @@ revalidate(const char __user *str, size_t size) 
		pr_err("aoe: invalid device specification %s\n", buf);

		return -EINVAL;

	}

	d = aoedev_by_aoeaddr(major, minor);

	d = aoedev_by_aoeaddr(major, minor, 0);

	if (!d)

		return -EINVAL;

	spin_lock_irqsave(&d->lock, flags);

drivers/block/aoe/aoecmd.c

+8 −17
Original line number Diff line number Diff line
@@ -1149,7 +1149,7 @@ aoecmd_ata_rsp(struct sk_buff *skb) 


	h = (struct aoe_hdr *) skb->data;

	aoemajor = be16_to_cpu(get_unaligned(&h->major));

	d = aoedev_by_aoeaddr(aoemajor, h->minor);

	d = aoedev_by_aoeaddr(aoemajor, h->minor, 0);

	if (d == NULL) {

		snprintf(ebuf, sizeof ebuf, "aoecmd_ata_rsp: ata response "

			"for unknown device %d.%d\n",
@@ -1330,7 +1330,7 @@ aoecmd_cfg_rsp(struct sk_buff *skb) 
	struct aoe_hdr *h;

	struct aoe_cfghdr *ch;

	struct aoetgt *t;

	ulong flags, sysminor, aoemajor;

	ulong flags, aoemajor;

	struct sk_buff *sl;

	struct sk_buff_head queue;

	u16 n;
@@ -1349,18 +1349,15 @@ aoecmd_cfg_rsp(struct sk_buff *skb) 
			"Check shelf dip switches.\n");

		return;

	}

	if (h->minor >= NPERSHELF) {

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

			aoemajor, h->minor,

			"slot number larger than the maximum",

			NPERSHELF-1);

	if (aoemajor > AOE_MAXSHELF) {

		pr_info("aoe: e%ld.%d: shelf number too large\n",

			aoemajor, (int) h->minor);

		return;

	}



	sysminor = SYSMINOR(aoemajor, h->minor);

	if (sysminor * AOE_PARTITIONS + AOE_PARTITIONS > MINORMASK) {

		printk(KERN_INFO "aoe: e%ld.%d: minor number too large\n",

			aoemajor, (int) h->minor);

	d = aoedev_by_aoeaddr(aoemajor, h->minor, 1);

	if (d == NULL) {

		pr_info("aoe: device allocation failure\n");

		return;

	}
@@ -1368,12 +1365,6 @@ aoecmd_cfg_rsp(struct sk_buff *skb) 
	if (n > aoe_maxout)	/* keep it reasonable */

		n = aoe_maxout;



	d = aoedev_by_sysminor_m(sysminor);

	if (d == NULL) {

		printk(KERN_INFO "aoe: device sysminor_m failure\n");

		return;

	}



	spin_lock_irqsave(&d->lock, flags);



	t = gettgt(d, h->src);

drivers/block/aoe/aoedev.c

+59 −27
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ 
#include <linux/netdevice.h>

#include <linux/delay.h>

#include <linux/slab.h>

#include <linux/bitmap.h>

#include <linux/kdev_t.h>

#include "aoe.h"



static void dummy_timer(ulong);
@@ -19,35 +21,63 @@ static void skbpoolfree(struct aoedev *d); 
static struct aoedev *devlist;

static DEFINE_SPINLOCK(devlist_lock);



/*

 * Users who grab a pointer to the device with aoedev_by_aoeaddr or

 * aoedev_by_sysminor_m automatically get a reference count and must

 * be responsible for performing a aoedev_put.  With the addition of

 * async kthread processing I'm no longer confident that we can

 * guarantee consistency in the face of device flushes.

 *

 * For the time being, we only bother to add extra references for

 * frames sitting on the iocq.  When the kthreads finish processing

 * these frames, they will aoedev_put the device.

/* Because some systems will have one, many, or no

 *   - partitions,

 *   - slots per shelf,

 *   - or shelves,

 * we need some flexibility in the way the minor numbers

 * are allocated.  So they are dynamic.

 */

struct aoedev *

aoedev_by_aoeaddr(int maj, int min)

#define N_DEVS ((1U<<MINORBITS)/AOE_PARTITIONS)



static DEFINE_SPINLOCK(used_minors_lock);

static DECLARE_BITMAP(used_minors, N_DEVS);



static int

minor_get(ulong *minor)

{

	struct aoedev *d;

	ulong flags;

	ulong n;

	int error = 0;



	spin_lock_irqsave(&used_minors_lock, flags);

	n = find_first_zero_bit(used_minors, N_DEVS);

	if (n < N_DEVS)

		set_bit(n, used_minors);

	else

		error = -1;

	spin_unlock_irqrestore(&used_minors_lock, flags);



	*minor = n * AOE_PARTITIONS;

	return error;

}



	spin_lock_irqsave(&devlist_lock, flags);

static void

minor_free(ulong minor)

{

	ulong flags;



	for (d=devlist; d; d=d->next)

		if (d->aoemajor == maj && d->aoeminor == min) {

			d->ref++;

			break;

		}

	minor /= AOE_PARTITIONS;

	BUG_ON(minor >= N_DEVS);



	spin_unlock_irqrestore(&devlist_lock, flags);

	return d;

	spin_lock_irqsave(&used_minors_lock, flags);

	BUG_ON(!test_bit(minor, used_minors));

	clear_bit(minor, used_minors);

	spin_unlock_irqrestore(&used_minors_lock, flags);

}



/*

 * Users who grab a pointer to the device with aoedev_by_aoeaddr

 * automatically get a reference count and must be responsible

 * for performing a aoedev_put.  With the addition of async

 * kthread processing I'm no longer confident that we can

 * guarantee consistency in the face of device flushes.

 *

 * For the time being, we only bother to add extra references for

 * frames sitting on the iocq.  When the kthreads finish processing

 * these frames, they will aoedev_put the device.

 */



void

aoedev_put(struct aoedev *d)

{
@@ -159,6 +189,7 @@ aoedev_freedev(struct aoedev *d) 
	if (d->bufpool)

		mempool_destroy(d->bufpool);

	skbpoolfree(d);

	minor_free(d->sysminor);

	kfree(d);

}
@@ -246,22 +277,23 @@ skbpoolfree(struct aoedev *d) 
	__skb_queue_head_init(&d->skbpool);

}



/* find it or malloc it */

/* find it or allocate it */

struct aoedev *

aoedev_by_sysminor_m(ulong sysminor)

aoedev_by_aoeaddr(ulong maj, int min, int do_alloc)

{

	struct aoedev *d;

	int i;

	ulong flags;

	ulong sysminor;



	spin_lock_irqsave(&devlist_lock, flags);



	for (d=devlist; d; d=d->next)

		if (d->sysminor == sysminor) {

		if (d->aoemajor == maj && d->aoeminor == min) {

			d->ref++;

			break;

		}

	if (d)

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

		goto out;

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

	if (!d)
@@ -280,8 +312,8 @@ aoedev_by_sysminor_m(ulong sysminor) 
	for (i = 0; i < NFACTIVE; i++)

		INIT_LIST_HEAD(&d->factive[i]);

	d->sysminor = sysminor;

	d->aoemajor = AOEMAJOR(sysminor);

	d->aoeminor = AOEMINOR(sysminor);

	d->aoemajor = maj;

	d->aoeminor = min;

	d->mintimer = MINTIMER;

	d->next = devlist;

	devlist = d;

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