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Commit a8638622 authored by Maxim Levitsky's avatar Maxim Levitsky Committed by David Woodhouse
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mtd: blktrans: remove mtd_blkcore_priv, switch to per device queue and thread 



This is the biggest change. To make hotplug possible, and this layer 
clean, the mtd_blktrans_dev now contains everything for a single mtd 
block translation device. Also removed some very old leftovers.

Signed-off-by: default avatarMaxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 3bd45657

drivers/mtd/mtd_blkdevs.c

+58 −66
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 
#include <linux/mtd/mtd.h>

#include <linux/blkdev.h>

#include <linux/blkpg.h>

#include <linux/freezer.h>

#include <linux/spinlock.h>

#include <linux/hdreg.h>

#include <linux/init.h>
@@ -26,11 +25,6 @@ 


static LIST_HEAD(blktrans_majors);



struct mtd_blkcore_priv {

	struct task_struct *thread;

	struct request_queue *rq;

	spinlock_t queue_lock;

};



static int do_blktrans_request(struct mtd_blktrans_ops *tr,

			       struct mtd_blktrans_dev *dev,
@@ -61,7 +55,6 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr, 
				return -EIO;

		rq_flush_dcache_pages(req);

		return 0;



	case WRITE:

		if (!tr->writesect)

			return -EIO;
@@ -71,7 +64,6 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr, 
			if (tr->writesect(dev, block, buf))

				return -EIO;

		return 0;



	default:

		printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));

		return -EIO;
@@ -80,14 +72,13 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr, 


static int mtd_blktrans_thread(void *arg)

{

	struct mtd_blktrans_ops *tr = arg;

	struct request_queue *rq = tr->blkcore_priv->rq;

	struct mtd_blktrans_dev *dev = arg;

	struct request_queue *rq = dev->rq;

	struct request *req = NULL;



	spin_lock_irq(rq->queue_lock);



	while (!kthread_should_stop()) {

		struct mtd_blktrans_dev *dev;

		int res;



		if (!req && !(req = blk_fetch_request(rq))) {
@@ -98,13 +89,10 @@ static int mtd_blktrans_thread(void *arg) 
			continue;

		}



		dev = req->rq_disk->private_data;

		tr = dev->tr;



		spin_unlock_irq(rq->queue_lock);



		mutex_lock(&dev->lock);

		res = do_blktrans_request(tr, dev, req);

		res = do_blktrans_request(dev->tr, dev, req);

		mutex_unlock(&dev->lock);



		spin_lock_irq(rq->queue_lock);
@@ -123,8 +111,8 @@ static int mtd_blktrans_thread(void *arg) 


static void mtd_blktrans_request(struct request_queue *rq)

{

	struct mtd_blktrans_ops *tr = rq->queuedata;

	wake_up_process(tr->blkcore_priv->thread);

	struct mtd_blktrans_dev *dev = rq->queuedata;

	wake_up_process(dev->thread);

}
@@ -214,6 +202,7 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) 
	struct mtd_blktrans_dev *d;

	int last_devnum = -1;

	struct gendisk *gd;

	int ret;



	if (mutex_trylock(&mtd_table_mutex)) {

		mutex_unlock(&mtd_table_mutex);
@@ -239,6 +228,8 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) 
		}

		last_devnum = d->devnum;

	}



	ret = -EBUSY;

	if (new->devnum == -1)

		new->devnum = last_devnum+1;
@@ -247,7 +238,7 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) 
	 * with this number. */

	if (new->devnum > (MINORMASK >> tr->part_bits) ||

	    (tr->part_bits && new->devnum >= 27 * 26))

		return -EBUSY;

		goto error1;



	list_add_tail(&new->list, &tr->devs);

 added:
@@ -255,11 +246,16 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) 
	if (!tr->writesect)

		new->readonly = 1;





	/* Create gendisk */

	ret = -ENOMEM;

	gd = alloc_disk(1 << tr->part_bits);

	if (!gd) {

		list_del(&new->list);

		return -ENOMEM;

	}



	if (!gd)

		goto error2;



	new->disk = gd;

	gd->private_data = new;

	gd->major = tr->major;

	gd->first_minor = (new->devnum) << tr->part_bits;

	gd->fops = &mtd_blktrans_ops;
@@ -277,21 +273,49 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) 
		snprintf(gd->disk_name, sizeof(gd->disk_name),

			 "%s%d", tr->name, new->devnum);



	/* 2.5 has capacity in units of 512 bytes while still

	   having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */

	set_capacity(gd, (new->size * tr->blksize) >> 9);



	gd->private_data = new;

	new->blkcore_priv = gd;

	gd->queue = tr->blkcore_priv->rq;



	/* Create the request queue */

	spin_lock_init(&new->queue_lock);

	new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);



	if (!new->rq)

		goto error3;



	new->rq->queuedata = new;

	blk_queue_logical_block_size(new->rq, tr->blksize);



	if (tr->discard)

		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,

					new->rq);



	gd->queue = new->rq;



	/* Create processing thread */

	/* TODO: workqueue ? */

	new->thread = kthread_run(mtd_blktrans_thread, new,

			"%s%d", tr->name, new->mtd->index);

	if (IS_ERR(new->thread)) {

		ret = PTR_ERR(new->thread);

		goto error4;

	}

	gd->driverfs_dev = &new->mtd->dev;



	if (new->readonly)

		set_disk_ro(gd, 1);



	add_disk(gd);



	return 0;

error4:

	blk_cleanup_queue(new->rq);

error3:

	put_disk(new->disk);

error2:

	list_del(&new->list);

error1:

	kfree(new);

	return ret;

}



int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
@@ -303,9 +327,13 @@ int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) 


	list_del(&old->list);



	del_gendisk(old->blkcore_priv);

	put_disk(old->blkcore_priv);

	/* stop new requests to arrive */

	del_gendisk(old->disk);



	/* Stop the thread */

	kthread_stop(old->thread);



	blk_cleanup_queue(old->rq);

	return 0;

}
@@ -347,9 +375,6 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr) 
	if (!blktrans_notifier.list.next)

		register_mtd_user(&blktrans_notifier);



	tr->blkcore_priv = kzalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL);

	if (!tr->blkcore_priv)

		return -ENOMEM;



	mutex_lock(&mtd_table_mutex);
@@ -357,39 +382,12 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr) 
	if (ret) {

		printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",

		       tr->name, tr->major, ret);

		kfree(tr->blkcore_priv);

		mutex_unlock(&mtd_table_mutex);

		return ret;

	}

	spin_lock_init(&tr->blkcore_priv->queue_lock);



	tr->blkcore_priv->rq = blk_init_queue(mtd_blktrans_request, &tr->blkcore_priv->queue_lock);

	if (!tr->blkcore_priv->rq) {

		unregister_blkdev(tr->major, tr->name);

		kfree(tr->blkcore_priv);

		mutex_unlock(&mtd_table_mutex);

		return -ENOMEM;

	}



	tr->blkcore_priv->rq->queuedata = tr;

	blk_queue_logical_block_size(tr->blkcore_priv->rq, tr->blksize);

	if (tr->discard)

		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,

					tr->blkcore_priv->rq);



	tr->blkshift = ffs(tr->blksize) - 1;



	tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr,

			"%sd", tr->name);

	if (IS_ERR(tr->blkcore_priv->thread)) {

		ret = PTR_ERR(tr->blkcore_priv->thread);

		blk_cleanup_queue(tr->blkcore_priv->rq);

		unregister_blkdev(tr->major, tr->name);

		kfree(tr->blkcore_priv);

		mutex_unlock(&mtd_table_mutex);

		return ret;

	}



	INIT_LIST_HEAD(&tr->devs);

	list_add(&tr->list, &blktrans_majors);
@@ -408,8 +406,6 @@ int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) 


	mutex_lock(&mtd_table_mutex);



	/* Clean up the kernel thread */

	kthread_stop(tr->blkcore_priv->thread);



	/* Remove it from the list of active majors */

	list_del(&tr->list);
@@ -417,13 +413,9 @@ int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) 
	list_for_each_entry_safe(dev, next, &tr->devs, list)

		tr->remove_dev(dev);



	blk_cleanup_queue(tr->blkcore_priv->rq);

	unregister_blkdev(tr->major, tr->name);



	mutex_unlock(&mtd_table_mutex);



	kfree(tr->blkcore_priv);



	BUG_ON(!list_empty(&tr->devs));

	return 0;

}

include/linux/mtd/blktrans.h

+5 −5
Original line number Diff line number Diff line
@@ -24,11 +24,13 @@ struct mtd_blktrans_dev { 
	int devnum;

	unsigned long size;

	int readonly;

	void *blkcore_priv; /* gendisk in 2.5, devfs_handle in 2.4 */

	struct gendisk *disk;

	struct task_struct *thread;

	struct request_queue *rq;

	spinlock_t queue_lock;

	void *priv;

};



struct blkcore_priv; /* Differs for 2.4 and 2.5 kernels; private */



struct mtd_blktrans_ops {

	char *name;

	int major;
@@ -60,8 +62,6 @@ struct mtd_blktrans_ops { 
	struct list_head devs;

	struct list_head list;

	struct module *owner;



	struct mtd_blkcore_priv *blkcore_priv;

};



extern int register_mtd_blktrans(struct mtd_blktrans_ops *tr);