Skip to content

Commit

Permalink
mtd: blktrans: remove mtd_blkcore_priv, switch to per device queue an…
Browse files Browse the repository at this point in the history 
…d 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: Maxim Levitsky <[email protected]>
Signed-off-by: David Woodhouse <[email protected]>
  • Loading branch information
@maximlevitsky
maximlevitsky authored and David Woodhouse committed Feb 26, 2010
1 parent 3bd4565 commit a863862
Show file tree
Hide file tree
Showing 2 changed files with 63 additions and 71 deletions.
124 changes: 58 additions & 66 deletions drivers/mtd/mtd_blkdevs.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand All @@ -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,
Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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))) {
Expand All @@ -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);
Expand All @@ -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);
}


Expand Down Expand Up @@ -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);
Expand All @@ -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;

Expand All @@ -247,19 +238,24 @@ 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:
mutex_init(&new->lock);
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;
Expand All @@ -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)
Expand All @@ -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;
}

Expand Down Expand Up @@ -347,49 +375,19 @@ 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);

ret = register_blkdev(tr->major, tr->name);
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);

Expand All @@ -408,22 +406,16 @@ 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);

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;
}
Expand Down
10 changes: 5 additions & 5 deletions include/linux/mtd/blktrans.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down

0 comments on commit a863862

Please sign in to comment.