drivers/block/aoe/aoeblk.c - kernel/msm-4.9 - Gitiles

 /* Copyright (c) 2012 Coraid, Inc.  See COPYING for GPL terms. */
 /*
  * aoeblk.c
  * block device routines
  */

 #include <linux/kernel.h>
 #include <linux/hdreg.h>
 #include <linux/blkdev.h>
 #include <linux/backing-dev.h>
 #include <linux/fs.h>
 #include <linux/ioctl.h>
 #include <linux/slab.h>
 #include <linux/ratelimit.h>
 #include <linux/genhd.h>
 #include <linux/netdevice.h>
 #include <linux/mutex.h>
 #include <linux/export.h>
 #include <linux/moduleparam.h>
 #include <scsi/sg.h>
 #include "aoe.h"

 static DEFINE_MUTEX(aoeblk_mutex);
 static struct kmem_cache *buf_pool_cache;

 /* GPFS needs a larger value than the default. */
 static int aoe_maxsectors;
 module_param(aoe_maxsectors, int, 0644);
 MODULE_PARM_DESC(aoe_maxsectors,
 	"When nonzero, set the maximum number of sectors per I/O request");

 static ssize_t aoedisk_show_state(struct device *dev,
 				  struct device_attribute *attr, char *page)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 	struct aoedev *d = disk->private_data;

 	return snprintf(page, PAGE_SIZE,
 			"%s%s\n",
 			(d->flags & DEVFL_UP) ? "up" : "down",
 			(d->flags & DEVFL_KICKME) ? ",kickme" :
 			(d->nopen && !(d->flags & DEVFL_UP)) ? ",closewait" : "");
 	/* I'd rather see nopen exported so we can ditch closewait */
 }
 static ssize_t aoedisk_show_mac(struct device *dev,
 				struct device_attribute *attr, char *page)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 	struct aoedev *d = disk->private_data;
 	struct aoetgt *t = d->targets[0];

 	if (t == NULL)
 		return snprintf(page, PAGE_SIZE, "none\n");
 	return snprintf(page, PAGE_SIZE, "%pm\n", t->addr);
 }
 static ssize_t aoedisk_show_netif(struct device *dev,
 				  struct device_attribute *attr, char *page)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 	struct aoedev *d = disk->private_data;
 	struct net_device *nds[8], **nd, **nnd, **ne;
 	struct aoetgt **t, **te;
 	struct aoeif *ifp, *e;
 	char *p;

 	memset(nds, 0, sizeof nds);
 	nd = nds;
 	ne = nd + ARRAY_SIZE(nds);
 	t = d->targets;
 	te = t + d->ntargets;
 	for (; t < te && *t; t++) {
 		ifp = (*t)->ifs;
 		e = ifp + NAOEIFS;
 		for (; ifp < e && ifp->nd; ifp++) {
 			for (nnd = nds; nnd < nd; nnd++)
 				if (*nnd == ifp->nd)
 					break;
 			if (nnd == nd && nd != ne)
 				*nd++ = ifp->nd;
 		}
 	}

 	ne = nd;
 	nd = nds;
 	if (*nd == NULL)
 		return snprintf(page, PAGE_SIZE, "none\n");
 	for (p = page; nd < ne; nd++)
 		p += snprintf(p, PAGE_SIZE - (p-page), "%s%s",
 			p == page ? "" : ",", (*nd)->name);
 	p += snprintf(p, PAGE_SIZE - (p-page), "\n");
 	return p-page;
 }
 /* firmware version */
 static ssize_t aoedisk_show_fwver(struct device *dev,
 				  struct device_attribute *attr, char *page)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 	struct aoedev *d = disk->private_data;

 	return snprintf(page, PAGE_SIZE, "0x%04x\n", (unsigned int) d->fw_ver);
 }
 static ssize_t aoedisk_show_payload(struct device *dev,
 				    struct device_attribute *attr, char *page)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 	struct aoedev *d = disk->private_data;

 	return snprintf(page, PAGE_SIZE, "%lu\n", d->maxbcnt);
 }

 static DEVICE_ATTR(state, S_IRUGO, aoedisk_show_state, NULL);
 static DEVICE_ATTR(mac, S_IRUGO, aoedisk_show_mac, NULL);
 static DEVICE_ATTR(netif, S_IRUGO, aoedisk_show_netif, NULL);
 static struct device_attribute dev_attr_firmware_version = {
 	.attr = { .name = "firmware-version", .mode = S_IRUGO },
 	.show = aoedisk_show_fwver,
 };
 static DEVICE_ATTR(payload, S_IRUGO, aoedisk_show_payload, NULL);

 static struct attribute *aoe_attrs[] = {
 	&dev_attr_state.attr,
 	&dev_attr_mac.attr,
 	&dev_attr_netif.attr,
 	&dev_attr_firmware_version.attr,
 	&dev_attr_payload.attr,
 	NULL,
 };

 static const struct attribute_group attr_group = {
 	.attrs = aoe_attrs,
 };

 static int
 aoedisk_add_sysfs(struct aoedev *d)
 {
 	return sysfs_create_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 }
 void
 aoedisk_rm_sysfs(struct aoedev *d)
 {
 	sysfs_remove_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 }

 static int
 aoeblk_open(struct block_device *bdev, fmode_t mode)
 {
 	struct aoedev *d = bdev->bd_disk->private_data;
 	ulong flags;

 	if (!virt_addr_valid(d)) {
 		pr_crit("aoe: invalid device pointer in %s\n",
 			__func__);
 		WARN_ON(1);
 		return -ENODEV;
 	}
 	if (!(d->flags & DEVFL_UP) || d->flags & DEVFL_TKILL)
 		return -ENODEV;

 	mutex_lock(&aoeblk_mutex);
 	spin_lock_irqsave(&d->lock, flags);
 	if (d->flags & DEVFL_UP && !(d->flags & DEVFL_TKILL)) {
 		d->nopen++;
 		spin_unlock_irqrestore(&d->lock, flags);
 		mutex_unlock(&aoeblk_mutex);
 		return 0;
 	}
 	spin_unlock_irqrestore(&d->lock, flags);
 	mutex_unlock(&aoeblk_mutex);
 	return -ENODEV;
 }

 static int
 aoeblk_release(struct gendisk *disk, fmode_t mode)
 {
 	struct aoedev *d = disk->private_data;
 	ulong flags;

 	spin_lock_irqsave(&d->lock, flags);

 	if (--d->nopen == 0) {
 		spin_unlock_irqrestore(&d->lock, flags);
 		aoecmd_cfg(d->aoemajor, d->aoeminor);
 		return 0;
 	}
 	spin_unlock_irqrestore(&d->lock, flags);

 	return 0;
 }

 static void
 aoeblk_request(struct request_queue *q)
 {
 	struct aoedev *d;
 	struct request *rq;

 	d = q->queuedata;
 	if ((d->flags & DEVFL_UP) == 0) {
 		pr_info_ratelimited("aoe: device %ld.%d is not up\n",
 			d->aoemajor, d->aoeminor);
 		while ((rq = blk_peek_request(q))) {
 			blk_start_request(rq);
 			aoe_end_request(d, rq, 1);
 		}
 		return;
 	}
 	aoecmd_work(d);
 }

 static int
 aoeblk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 {
 	struct aoedev *d = bdev->bd_disk->private_data;

 	if ((d->flags & DEVFL_UP) == 0) {
 		printk(KERN_ERR "aoe: disk not up\n");
 		return -ENODEV;
 	}

 	geo->cylinders = d->geo.cylinders;
 	geo->heads = d->geo.heads;
 	geo->sectors = d->geo.sectors;
 	return 0;
 }

 static int
 aoeblk_ioctl(struct block_device *bdev, fmode_t mode, uint cmd, ulong arg)
 {
 	struct aoedev *d;

 	if (!arg)
 		return -EINVAL;

 	d = bdev->bd_disk->private_data;
 	if ((d->flags & DEVFL_UP) == 0) {
 		pr_err("aoe: disk not up\n");
 		return -ENODEV;
 	}

 	if (cmd == HDIO_GET_IDENTITY) {
 		if (!copy_to_user((void __user *) arg, &d->ident,
 			sizeof(d->ident)))
 			return 0;
 		return -EFAULT;
 	}

 	/* udev calls scsi_id, which uses SG_IO, resulting in noise */
 	if (cmd != SG_IO)
 		pr_info("aoe: unknown ioctl 0x%x\n", cmd);

 	return -ENOTTY;
 }

 static const struct block_device_operations aoe_bdops = {
 	.open = aoeblk_open,
 	.release = aoeblk_release,
 	.ioctl = aoeblk_ioctl,
 	.getgeo = aoeblk_getgeo,
 	.owner = THIS_MODULE,
 };

 /* alloc_disk and add_disk can sleep */
 void
 aoeblk_gdalloc(void *vp)
 {
 	struct aoedev *d = vp;
 	struct gendisk *gd;
 	mempool_t *mp;
 	struct request_queue *q;
 	enum { KB = 1024, MB = KB * KB, READ_AHEAD = 2 * MB, };
 	ulong flags;
 	int late = 0;

 	spin_lock_irqsave(&d->lock, flags);
 	if (d->flags & DEVFL_GDALLOC
 	&& !(d->flags & DEVFL_TKILL)
 	&& !(d->flags & DEVFL_GD_NOW))
 		d->flags |= DEVFL_GD_NOW;
 	else
 		late = 1;
 	spin_unlock_irqrestore(&d->lock, flags);
 	if (late)
 		return;

 	gd = alloc_disk(AOE_PARTITIONS);
 	if (gd == NULL) {
 		pr_err("aoe: cannot allocate disk structure for %ld.%d\n",
 			d->aoemajor, d->aoeminor);
 		goto err;
 	}

 	mp = mempool_create(MIN_BUFS, mempool_alloc_slab, mempool_free_slab,
 		buf_pool_cache);
 	if (mp == NULL) {
 		printk(KERN_ERR "aoe: cannot allocate bufpool for %ld.%d\n",
 			d->aoemajor, d->aoeminor);
 		goto err_disk;
 	}
 	q = blk_init_queue(aoeblk_request, &d->lock);
 	if (q == NULL) {
 		pr_err("aoe: cannot allocate block queue for %ld.%d\n",
 			d->aoemajor, d->aoeminor);
 		goto err_mempool;
 	}

 	spin_lock_irqsave(&d->lock, flags);
 	WARN_ON(!(d->flags & DEVFL_GD_NOW));
 	WARN_ON(!(d->flags & DEVFL_GDALLOC));
 	WARN_ON(d->flags & DEVFL_TKILL);
 	WARN_ON(d->gd);
 	WARN_ON(d->flags & DEVFL_UP);
 	blk_queue_max_hw_sectors(q, BLK_DEF_MAX_SECTORS);
 	q->backing_dev_info.name = "aoe";
 	q->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE;
 	d->bufpool = mp;
 	d->blkq = gd->queue = q;
 	q->queuedata = d;
 	d->gd = gd;
 	if (aoe_maxsectors)
 		blk_queue_max_hw_sectors(q, aoe_maxsectors);
 	gd->major = AOE_MAJOR;
 	gd->first_minor = d->sysminor;
 	gd->fops = &aoe_bdops;
 	gd->private_data = d;
 	set_capacity(gd, d->ssize);
 	snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d",
 		d->aoemajor, d->aoeminor);

 	d->flags &= ~DEVFL_GDALLOC;
 	d->flags |= DEVFL_UP;

 	spin_unlock_irqrestore(&d->lock, flags);

 	add_disk(gd);
 	aoedisk_add_sysfs(d);

 	spin_lock_irqsave(&d->lock, flags);
 	WARN_ON(!(d->flags & DEVFL_GD_NOW));
 	d->flags &= ~DEVFL_GD_NOW;
 	spin_unlock_irqrestore(&d->lock, flags);
 	return;

 err_mempool:
 	mempool_destroy(mp);
 err_disk:
 	put_disk(gd);
 err:
 	spin_lock_irqsave(&d->lock, flags);
 	d->flags &= ~DEVFL_GD_NOW;
 	schedule_work(&d->work);
 	spin_unlock_irqrestore(&d->lock, flags);
 }

 void
 aoeblk_exit(void)
 {
 	kmem_cache_destroy(buf_pool_cache);
 }

 int __init
 aoeblk_init(void)
 {
 	buf_pool_cache = kmem_cache_create("aoe_bufs",
 					   sizeof(struct buf),
 					   0, 0, NULL);
 	if (buf_pool_cache == NULL)
 		return -ENOMEM;

 	return 0;
 }
	/* Copyright (c) 2012 Coraid, Inc. See COPYING for GPL terms. */
	/*
	* aoeblk.c
	* block device routines
	*/

	#include <linux/kernel.h>
	#include <linux/hdreg.h>
	#include <linux/blkdev.h>
	#include <linux/backing-dev.h>
	#include <linux/fs.h>
	#include <linux/ioctl.h>
	#include <linux/slab.h>
	#include <linux/ratelimit.h>
	#include <linux/genhd.h>
	#include <linux/netdevice.h>
	#include <linux/mutex.h>
	#include <linux/export.h>
	#include <linux/moduleparam.h>
	#include <scsi/sg.h>
	#include "aoe.h"

	static DEFINE_MUTEX(aoeblk_mutex);
	static struct kmem_cache *buf_pool_cache;

	/* GPFS needs a larger value than the default. */
	static int aoe_maxsectors;
	module_param(aoe_maxsectors, int, 0644);
	MODULE_PARM_DESC(aoe_maxsectors,
	"When nonzero, set the maximum number of sectors per I/O request");

	static ssize_t aoedisk_show_state(struct device *dev,
	struct device_attribute attr, char page)
	{
	struct gendisk *disk = dev_to_disk(dev);
	struct aoedev *d = disk->private_data;

	return snprintf(page, PAGE_SIZE,
	"%s%s\n",
	(d->flags & DEVFL_UP) ? "up" : "down",
	(d->flags & DEVFL_KICKME) ? ",kickme" :
	(d->nopen && !(d->flags & DEVFL_UP)) ? ",closewait" : "");
	/* I'd rather see nopen exported so we can ditch closewait */
	}
	static ssize_t aoedisk_show_mac(struct device *dev,
	struct device_attribute attr, char page)
	{
	struct gendisk *disk = dev_to_disk(dev);
	struct aoedev *d = disk->private_data;
	struct aoetgt *t = d->targets[0];

	if (t == NULL)
	return snprintf(page, PAGE_SIZE, "none\n");
	return snprintf(page, PAGE_SIZE, "%pm\n", t->addr);
	}
	static ssize_t aoedisk_show_netif(struct device *dev,
	struct device_attribute attr, char page)
	{
	struct gendisk *disk = dev_to_disk(dev);
	struct aoedev *d = disk->private_data;
	struct net_device nds[8], nd, nnd, *ne;
	struct aoetgt t, te;
	struct aoeif ifp, e;
	char *p;

	memset(nds, 0, sizeof nds);
	nd = nds;
	ne = nd + ARRAY_SIZE(nds);
	t = d->targets;
	te = t + d->ntargets;
	for (; t < te && *t; t++) {
	ifp = (*t)->ifs;
	e = ifp + NAOEIFS;
	for (; ifp < e && ifp->nd; ifp++) {
	for (nnd = nds; nnd < nd; nnd++)
	if (*nnd == ifp->nd)
	break;
	if (nnd == nd && nd != ne)
	*nd++ = ifp->nd;
	}
	}

	ne = nd;
	nd = nds;
	if (*nd == NULL)
	return snprintf(page, PAGE_SIZE, "none\n");
	for (p = page; nd < ne; nd++)
	p += snprintf(p, PAGE_SIZE - (p-page), "%s%s",
	p == page ? "" : ",", (*nd)->name);
	p += snprintf(p, PAGE_SIZE - (p-page), "\n");
	return p-page;
	}
	/* firmware version */
	static ssize_t aoedisk_show_fwver(struct device *dev,
	struct device_attribute attr, char page)
	{
	struct gendisk *disk = dev_to_disk(dev);
	struct aoedev *d = disk->private_data;

	return snprintf(page, PAGE_SIZE, "0x%04x\n", (unsigned int) d->fw_ver);
	}
	static ssize_t aoedisk_show_payload(struct device *dev,
	struct device_attribute attr, char page)
	{
	struct gendisk *disk = dev_to_disk(dev);
	struct aoedev *d = disk->private_data;

	return snprintf(page, PAGE_SIZE, "%lu\n", d->maxbcnt);
	}

	static DEVICE_ATTR(state, S_IRUGO, aoedisk_show_state, NULL);
	static DEVICE_ATTR(mac, S_IRUGO, aoedisk_show_mac, NULL);
	static DEVICE_ATTR(netif, S_IRUGO, aoedisk_show_netif, NULL);
	static struct device_attribute dev_attr_firmware_version = {
	.attr = { .name = "firmware-version", .mode = S_IRUGO },
	.show = aoedisk_show_fwver,
	};
	static DEVICE_ATTR(payload, S_IRUGO, aoedisk_show_payload, NULL);

	static struct attribute *aoe_attrs[] = {
	&dev_attr_state.attr,
	&dev_attr_mac.attr,
	&dev_attr_netif.attr,
	&dev_attr_firmware_version.attr,
	&dev_attr_payload.attr,
	NULL,
	};

	static const struct attribute_group attr_group = {
	.attrs = aoe_attrs,
	};

	static int
	aoedisk_add_sysfs(struct aoedev *d)
	{
	return sysfs_create_group(&disk_to_dev(d->gd)->kobj, &attr_group);
	}
	void
	aoedisk_rm_sysfs(struct aoedev *d)
	{
	sysfs_remove_group(&disk_to_dev(d->gd)->kobj, &attr_group);
	}

	static int
	aoeblk_open(struct block_device *bdev, fmode_t mode)
	{
	struct aoedev *d = bdev->bd_disk->private_data;
	ulong flags;

	if (!virt_addr_valid(d)) {
	pr_crit("aoe: invalid device pointer in %s\n",
	__func__);
	WARN_ON(1);
	return -ENODEV;
	}
	if (!(d->flags & DEVFL_UP) \|\| d->flags & DEVFL_TKILL)
	return -ENODEV;

	mutex_lock(&aoeblk_mutex);
	spin_lock_irqsave(&d->lock, flags);
	if (d->flags & DEVFL_UP && !(d->flags & DEVFL_TKILL)) {
	d->nopen++;
	spin_unlock_irqrestore(&d->lock, flags);
	mutex_unlock(&aoeblk_mutex);
	return 0;
	}
	spin_unlock_irqrestore(&d->lock, flags);
	mutex_unlock(&aoeblk_mutex);
	return -ENODEV;
	}

	static int
	aoeblk_release(struct gendisk *disk, fmode_t mode)
	{
	struct aoedev *d = disk->private_data;
	ulong flags;

	spin_lock_irqsave(&d->lock, flags);

	if (--d->nopen == 0) {
	spin_unlock_irqrestore(&d->lock, flags);
	aoecmd_cfg(d->aoemajor, d->aoeminor);
	return 0;
	}
	spin_unlock_irqrestore(&d->lock, flags);

	return 0;
	}

	static void
	aoeblk_request(struct request_queue *q)
	{
	struct aoedev *d;
	struct request *rq;

	d = q->queuedata;
	if ((d->flags & DEVFL_UP) == 0) {
	pr_info_ratelimited("aoe: device %ld.%d is not up\n",
	d->aoemajor, d->aoeminor);
	while ((rq = blk_peek_request(q))) {
	blk_start_request(rq);
	aoe_end_request(d, rq, 1);
	}
	return;
	}
	aoecmd_work(d);
	}

	static int
	aoeblk_getgeo(struct block_device bdev, struct hd_geometry geo)
	{
	struct aoedev *d = bdev->bd_disk->private_data;

	if ((d->flags & DEVFL_UP) == 0) {
	printk(KERN_ERR "aoe: disk not up\n");
	return -ENODEV;
	}

	geo->cylinders = d->geo.cylinders;
	geo->heads = d->geo.heads;
	geo->sectors = d->geo.sectors;
	return 0;
	}

	static int
	aoeblk_ioctl(struct block_device *bdev, fmode_t mode, uint cmd, ulong arg)
	{
	struct aoedev *d;

	if (!arg)
	return -EINVAL;

	d = bdev->bd_disk->private_data;
	if ((d->flags & DEVFL_UP) == 0) {
	pr_err("aoe: disk not up\n");
	return -ENODEV;
	}

	if (cmd == HDIO_GET_IDENTITY) {
	if (!copy_to_user((void __user *) arg, &d->ident,
	sizeof(d->ident)))
	return 0;
	return -EFAULT;
	}

	/* udev calls scsi_id, which uses SG_IO, resulting in noise */
	if (cmd != SG_IO)
	pr_info("aoe: unknown ioctl 0x%x\n", cmd);

	return -ENOTTY;
	}

	static const struct block_device_operations aoe_bdops = {
	.open = aoeblk_open,
	.release = aoeblk_release,
	.ioctl = aoeblk_ioctl,
	.getgeo = aoeblk_getgeo,
	.owner = THIS_MODULE,
	};

	/* alloc_disk and add_disk can sleep */
	void
	aoeblk_gdalloc(void *vp)
	{
	struct aoedev *d = vp;
	struct gendisk *gd;
	mempool_t *mp;
	struct request_queue *q;
	enum { KB = 1024, MB = KB * KB, READ_AHEAD = 2 * MB, };
	ulong flags;
	int late = 0;

	spin_lock_irqsave(&d->lock, flags);
	if (d->flags & DEVFL_GDALLOC
	&& !(d->flags & DEVFL_TKILL)
	&& !(d->flags & DEVFL_GD_NOW))
	d->flags \|= DEVFL_GD_NOW;
	else
	late = 1;
	spin_unlock_irqrestore(&d->lock, flags);
	if (late)
	return;

	gd = alloc_disk(AOE_PARTITIONS);
	if (gd == NULL) {
	pr_err("aoe: cannot allocate disk structure for %ld.%d\n",
	d->aoemajor, d->aoeminor);
	goto err;
	}

	mp = mempool_create(MIN_BUFS, mempool_alloc_slab, mempool_free_slab,
	buf_pool_cache);
	if (mp == NULL) {
	printk(KERN_ERR "aoe: cannot allocate bufpool for %ld.%d\n",
	d->aoemajor, d->aoeminor);
	goto err_disk;
	}
	q = blk_init_queue(aoeblk_request, &d->lock);
	if (q == NULL) {
	pr_err("aoe: cannot allocate block queue for %ld.%d\n",
	d->aoemajor, d->aoeminor);
	goto err_mempool;
	}

	spin_lock_irqsave(&d->lock, flags);
	WARN_ON(!(d->flags & DEVFL_GD_NOW));
	WARN_ON(!(d->flags & DEVFL_GDALLOC));
	WARN_ON(d->flags & DEVFL_TKILL);
	WARN_ON(d->gd);
	WARN_ON(d->flags & DEVFL_UP);
	blk_queue_max_hw_sectors(q, BLK_DEF_MAX_SECTORS);
	q->backing_dev_info.name = "aoe";
	q->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE;
	d->bufpool = mp;
	d->blkq = gd->queue = q;
	q->queuedata = d;
	d->gd = gd;
	if (aoe_maxsectors)
	blk_queue_max_hw_sectors(q, aoe_maxsectors);
	gd->major = AOE_MAJOR;
	gd->first_minor = d->sysminor;
	gd->fops = &aoe_bdops;
	gd->private_data = d;
	set_capacity(gd, d->ssize);
	snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d",
	d->aoemajor, d->aoeminor);

	d->flags &= ~DEVFL_GDALLOC;
	d->flags \|= DEVFL_UP;

	spin_unlock_irqrestore(&d->lock, flags);

	add_disk(gd);
	aoedisk_add_sysfs(d);

	spin_lock_irqsave(&d->lock, flags);
	WARN_ON(!(d->flags & DEVFL_GD_NOW));
	d->flags &= ~DEVFL_GD_NOW;
	spin_unlock_irqrestore(&d->lock, flags);
	return;

	err_mempool:
	mempool_destroy(mp);
	err_disk:
	put_disk(gd);
	err:
	spin_lock_irqsave(&d->lock, flags);
	d->flags &= ~DEVFL_GD_NOW;
	schedule_work(&d->work);
	spin_unlock_irqrestore(&d->lock, flags);
	}

	void
	aoeblk_exit(void)
	{
	kmem_cache_destroy(buf_pool_cache);
	}

	int __init
	aoeblk_init(void)
	{
	buf_pool_cache = kmem_cache_create("aoe_bufs",
	sizeof(struct buf),
	0, 0, NULL);
	if (buf_pool_cache == NULL)
	return -ENOMEM;

	return 0;
	}