/*
- * $Id: mtd_blkdevs.c,v 1.27 2005/11/07 11:14:20 gleixner Exp $
+ * Interface to Linux block layer for MTD 'translation layers'.
*
- * (C) 2003 David Woodhouse <dwmw2@infradead.org>
+ * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org>
*
- * Interface to Linux 2.5 block layer for MTD 'translation layers'.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/hdreg.h>
#include <linux/init.h>
#include <linux/mutex.h>
-#include <linux/kthread.h>
#include <asm/uaccess.h>
+#include "mtdcore.h"
+
static LIST_HEAD(blktrans_majors);
+static DEFINE_MUTEX(blktrans_ref_mutex);
-extern struct mutex mtd_table_mutex;
-extern struct mtd_info *mtd_table[];
+static void blktrans_dev_release(struct kref *kref)
+{
+ struct mtd_blktrans_dev *dev =
+ container_of(kref, struct mtd_blktrans_dev, ref);
+
+ dev->disk->private_data = NULL;
+ blk_cleanup_queue(dev->rq);
+ put_disk(dev->disk);
+ list_del(&dev->list);
+ kfree(dev);
+}
+
+static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk)
+{
+ struct mtd_blktrans_dev *dev;
+
+ mutex_lock(&blktrans_ref_mutex);
+ dev = disk->private_data;
+
+ if (!dev)
+ goto unlock;
+ kref_get(&dev->ref);
+unlock:
+ mutex_unlock(&blktrans_ref_mutex);
+ return dev;
+}
+
+static void blktrans_dev_put(struct mtd_blktrans_dev *dev)
+{
+ mutex_lock(&blktrans_ref_mutex);
+ kref_put(&dev->ref, blktrans_dev_release);
+ mutex_unlock(&blktrans_ref_mutex);
+}
-struct mtd_blkcore_priv {
- struct completion thread_dead;
- int exiting;
- wait_queue_head_t thread_wq;
- struct request_queue *rq;
- spinlock_t queue_lock;
-};
static int do_blktrans_request(struct mtd_blktrans_ops *tr,
struct mtd_blktrans_dev *dev,
struct request *req)
{
- unsigned long block, nsect;
+ unsigned long long block, nsect;
char *buf;
- block = req->sector << 9 >> tr->blkshift;
- nsect = req->current_nr_sectors << 9 >> tr->blkshift;
+ block = blk_rq_pos(req) << 9 >> tr->blkshift;
+ nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
buf = req->buffer;
- if (!blk_fs_request(req))
- return 0;
+ if (req->cmd_type != REQ_TYPE_FS)
+ return -EIO;
- if (req->sector + req->current_nr_sectors > get_capacity(req->rq_disk))
- return 0;
+ if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
+ get_capacity(req->rq_disk))
+ return -EIO;
- switch(rq_data_dir(req)) {
+ if (req->cmd_flags & REQ_DISCARD)
+ return tr->discard(dev, block, nsect);
+
+ switch (rq_data_dir(req)) {
case READ:
for (; nsect > 0; nsect--, block++, buf += tr->blksize)
if (tr->readsect(dev, block, buf))
- return 0;
- return 1;
-
+ return -EIO;
+ rq_flush_dcache_pages(req);
+ return 0;
case WRITE:
if (!tr->writesect)
- return 0;
+ return -EIO;
+ rq_flush_dcache_pages(req);
for (; nsect > 0; nsect--, block++, buf += tr->blksize)
if (tr->writesect(dev, block, buf))
- return 0;
- return 1;
-
+ return -EIO;
+ return 0;
default:
printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
- return 0;
+ return -EIO;
}
}
-static int mtd_blktrans_thread(void *arg)
+int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
{
- struct mtd_blktrans_ops *tr = arg;
- struct request_queue *rq = tr->blkcore_priv->rq;
+ return dev->bg_stop;
+}
+EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
- /* we might get involved when memory gets low, so use PF_MEMALLOC */
- current->flags |= PF_MEMALLOC | PF_NOFREEZE;
+static void mtd_blktrans_work(struct work_struct *work)
+{
+ struct mtd_blktrans_dev *dev =
+ container_of(work, struct mtd_blktrans_dev, work);
+ struct mtd_blktrans_ops *tr = dev->tr;
+ struct request_queue *rq = dev->rq;
+ struct request *req = NULL;
+ int background_done = 0;
spin_lock_irq(rq->queue_lock);
- while (!tr->blkcore_priv->exiting) {
- struct request *req;
- struct mtd_blktrans_dev *dev;
- int res = 0;
- DECLARE_WAITQUEUE(wait, current);
-
- req = elv_next_request(rq);
-
- if (!req) {
- add_wait_queue(&tr->blkcore_priv->thread_wq, &wait);
- set_current_state(TASK_INTERRUPTIBLE);
-
- spin_unlock_irq(rq->queue_lock);
-
- schedule();
- remove_wait_queue(&tr->blkcore_priv->thread_wq, &wait);
-
- spin_lock_irq(rq->queue_lock);
-
- continue;
+ while (1) {
+ int res;
+
+ dev->bg_stop = false;
+ if (!req && !(req = blk_fetch_request(rq))) {
+ if (tr->background && !background_done) {
+ spin_unlock_irq(rq->queue_lock);
+ mutex_lock(&dev->lock);
+ tr->background(dev);
+ mutex_unlock(&dev->lock);
+ spin_lock_irq(rq->queue_lock);
+ /*
+ * Do background processing just once per idle
+ * period.
+ */
+ background_done = !dev->bg_stop;
+ continue;
+ }
+ break;
}
- 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);
- end_request(req, res);
+ if (!__blk_end_request_cur(req, res))
+ req = NULL;
+
+ background_done = 0;
}
- spin_unlock_irq(rq->queue_lock);
- complete_and_exit(&tr->blkcore_priv->thread_dead, 0);
+ if (req)
+ __blk_end_request_all(req, -EIO);
+
+ spin_unlock_irq(rq->queue_lock);
}
static void mtd_blktrans_request(struct request_queue *rq)
{
- struct mtd_blktrans_ops *tr = rq->queuedata;
- wake_up(&tr->blkcore_priv->thread_wq);
-}
+ struct mtd_blktrans_dev *dev;
+ struct request *req = NULL;
+ dev = rq->queuedata;
-static int blktrans_open(struct inode *i, struct file *f)
+ if (!dev)
+ while ((req = blk_fetch_request(rq)) != NULL)
+ __blk_end_request_all(req, -ENODEV);
+ else
+ queue_work(dev->wq, &dev->work);
+}
+
+static int blktrans_open(struct block_device *bdev, fmode_t mode)
{
- struct mtd_blktrans_dev *dev;
- struct mtd_blktrans_ops *tr;
- int ret = -ENODEV;
+ struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
+ int ret = 0;
+
+ if (!dev)
+ return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
- dev = i->i_bdev->bd_disk->private_data;
- tr = dev->tr;
+ mutex_lock(&dev->lock);
+ mutex_lock(&mtd_table_mutex);
- if (!try_module_get(dev->mtd->owner))
- goto out;
+ if (dev->open)
+ goto unlock;
- if (!try_module_get(tr->owner))
- goto out_tr;
+ kref_get(&dev->ref);
+ __module_get(dev->tr->owner);
- /* FIXME: Locking. A hot pluggable device can go away
- (del_mtd_device can be called for it) without its module
- being unloaded. */
- dev->mtd->usecount++;
+ if (!dev->mtd)
+ goto unlock;
- ret = 0;
- if (tr->open && (ret = tr->open(dev))) {
- dev->mtd->usecount--;
- module_put(dev->mtd->owner);
- out_tr:
- module_put(tr->owner);
+ if (dev->tr->open) {
+ ret = dev->tr->open(dev);
+ if (ret)
+ goto error_put;
}
- out:
+
+ ret = __get_mtd_device(dev->mtd);
+ if (ret)
+ goto error_release;
+ dev->file_mode = mode;
+
+unlock:
+ dev->open++;
+ mutex_unlock(&mtd_table_mutex);
+ mutex_unlock(&dev->lock);
+ blktrans_dev_put(dev);
+ return ret;
+
+error_release:
+ if (dev->tr->release)
+ dev->tr->release(dev);
+error_put:
+ module_put(dev->tr->owner);
+ kref_put(&dev->ref, blktrans_dev_release);
+ mutex_unlock(&mtd_table_mutex);
+ mutex_unlock(&dev->lock);
+ blktrans_dev_put(dev);
return ret;
}
-static int blktrans_release(struct inode *i, struct file *f)
+static void blktrans_release(struct gendisk *disk, fmode_t mode)
{
- struct mtd_blktrans_dev *dev;
- struct mtd_blktrans_ops *tr;
- int ret = 0;
+ struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
+
+ if (!dev)
+ return;
- dev = i->i_bdev->bd_disk->private_data;
- tr = dev->tr;
+ mutex_lock(&dev->lock);
+ mutex_lock(&mtd_table_mutex);
- if (tr->release)
- ret = tr->release(dev);
+ if (--dev->open)
+ goto unlock;
- if (!ret) {
- dev->mtd->usecount--;
- module_put(dev->mtd->owner);
- module_put(tr->owner);
- }
+ kref_put(&dev->ref, blktrans_dev_release);
+ module_put(dev->tr->owner);
- return ret;
+ if (dev->mtd) {
+ if (dev->tr->release)
+ dev->tr->release(dev);
+ __put_mtd_device(dev->mtd);
+ }
+unlock:
+ mutex_unlock(&mtd_table_mutex);
+ mutex_unlock(&dev->lock);
+ blktrans_dev_put(dev);
}
static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
- struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
+ struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
+ int ret = -ENXIO;
+
+ if (!dev)
+ return ret;
+
+ mutex_lock(&dev->lock);
- if (dev->tr->getgeo)
- return dev->tr->getgeo(dev, geo);
- return -ENOTTY;
+ if (!dev->mtd)
+ goto unlock;
+
+ ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0;
+unlock:
+ mutex_unlock(&dev->lock);
+ blktrans_dev_put(dev);
+ return ret;
}
-static int blktrans_ioctl(struct inode *inode, struct file *file,
+static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
- struct mtd_blktrans_dev *dev = inode->i_bdev->bd_disk->private_data;
- struct mtd_blktrans_ops *tr = dev->tr;
+ struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
+ int ret = -ENXIO;
+
+ if (!dev)
+ return ret;
+
+ mutex_lock(&dev->lock);
+
+ if (!dev->mtd)
+ goto unlock;
switch (cmd) {
case BLKFLSBUF:
- if (tr->flush)
- return tr->flush(dev);
- /* The core code did the work, we had nothing to do. */
- return 0;
+ ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
+ break;
default:
- return -ENOTTY;
+ ret = -ENOTTY;
}
+unlock:
+ mutex_unlock(&dev->lock);
+ blktrans_dev_put(dev);
+ return ret;
}
-struct block_device_operations mtd_blktrans_ops = {
+static const struct block_device_operations mtd_block_ops = {
.owner = THIS_MODULE,
.open = blktrans_open,
.release = blktrans_release,
int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
{
struct mtd_blktrans_ops *tr = new->tr;
- struct list_head *this;
+ struct mtd_blktrans_dev *d;
int last_devnum = -1;
struct gendisk *gd;
+ int ret;
- if (!!mutex_trylock(&mtd_table_mutex)) {
+ if (mutex_trylock(&mtd_table_mutex)) {
mutex_unlock(&mtd_table_mutex);
BUG();
}
- list_for_each(this, &tr->devs) {
- struct mtd_blktrans_dev *d = list_entry(this, struct mtd_blktrans_dev, list);
+ mutex_lock(&blktrans_ref_mutex);
+ list_for_each_entry(d, &tr->devs, list) {
if (new->devnum == -1) {
/* Use first free number */
if (d->devnum != last_devnum+1) {
}
} else if (d->devnum == new->devnum) {
/* Required number taken */
+ mutex_unlock(&blktrans_ref_mutex);
return -EBUSY;
} else if (d->devnum > new->devnum) {
/* Required number was free */
}
last_devnum = d->devnum;
}
+
+ ret = -EBUSY;
if (new->devnum == -1)
new->devnum = last_devnum+1;
- if ((new->devnum << tr->part_bits) > 256) {
- return -EBUSY;
+ /* Check that the device and any partitions will get valid
+ * minor numbers and that the disk naming code below can cope
+ * with this number. */
+ if (new->devnum > (MINORMASK >> tr->part_bits) ||
+ (tr->part_bits && new->devnum >= 27 * 26)) {
+ mutex_unlock(&blktrans_ref_mutex);
+ goto error1;
}
- mutex_init(&new->lock);
list_add_tail(&new->list, &tr->devs);
added:
+ mutex_unlock(&blktrans_ref_mutex);
+
+ mutex_init(&new->lock);
+ kref_init(&new->ref);
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;
+ gd->fops = &mtd_block_ops;
if (tr->part_bits)
if (new->devnum < 26)
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);
+
+ queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq);
+
+ if (tr->discard) {
+ queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq);
+ new->rq->limits.max_discard_sectors = UINT_MAX;
+ }
+
+ gd->queue = new->rq;
+
+ /* Create processing workqueue */
+ new->wq = alloc_workqueue("%s%d", 0, 0,
+ tr->name, new->mtd->index);
+ if (!new->wq)
+ goto error4;
+ INIT_WORK(&new->work, mtd_blktrans_work);
+
+ gd->driverfs_dev = &new->mtd->dev;
if (new->readonly)
set_disk_ro(gd, 1);
add_disk(gd);
+ if (new->disk_attributes) {
+ ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
+ new->disk_attributes);
+ WARN_ON(ret);
+ }
return 0;
+error4:
+ blk_cleanup_queue(new->rq);
+error3:
+ put_disk(new->disk);
+error2:
+ list_del(&new->list);
+error1:
+ return ret;
}
int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
{
- if (!!mutex_trylock(&mtd_table_mutex)) {
+ unsigned long flags;
+
+ if (mutex_trylock(&mtd_table_mutex)) {
mutex_unlock(&mtd_table_mutex);
BUG();
}
- list_del(&old->list);
+ if (old->disk_attributes)
+ sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
+ old->disk_attributes);
+
+ /* Stop new requests to arrive */
+ del_gendisk(old->disk);
+
+ /* Stop workqueue. This will perform any pending request. */
+ destroy_workqueue(old->wq);
+
+ /* Kill current requests */
+ spin_lock_irqsave(&old->queue_lock, flags);
+ old->rq->queuedata = NULL;
+ blk_start_queue(old->rq);
+ spin_unlock_irqrestore(&old->queue_lock, flags);
+
+ /* If the device is currently open, tell trans driver to close it,
+ then put mtd device, and don't touch it again */
+ mutex_lock(&old->lock);
+ if (old->open) {
+ if (old->tr->release)
+ old->tr->release(old);
+ __put_mtd_device(old->mtd);
+ }
- del_gendisk(old->blkcore_priv);
- put_disk(old->blkcore_priv);
+ old->mtd = NULL;
+ mutex_unlock(&old->lock);
+ blktrans_dev_put(old);
return 0;
}
static void blktrans_notify_remove(struct mtd_info *mtd)
{
- struct list_head *this, *this2, *next;
-
- list_for_each(this, &blktrans_majors) {
- struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list);
-
- list_for_each_safe(this2, next, &tr->devs) {
- struct mtd_blktrans_dev *dev = list_entry(this2, struct mtd_blktrans_dev, list);
+ struct mtd_blktrans_ops *tr;
+ struct mtd_blktrans_dev *dev, *next;
+ list_for_each_entry(tr, &blktrans_majors, list)
+ list_for_each_entry_safe(dev, next, &tr->devs, list)
if (dev->mtd == mtd)
tr->remove_dev(dev);
- }
- }
}
static void blktrans_notify_add(struct mtd_info *mtd)
{
- struct list_head *this;
+ struct mtd_blktrans_ops *tr;
if (mtd->type == MTD_ABSENT)
return;
- list_for_each(this, &blktrans_majors) {
- struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list);
-
+ list_for_each_entry(tr, &blktrans_majors, list)
tr->add_mtd(tr, mtd);
- }
-
}
static struct mtd_notifier blktrans_notifier = {
int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
{
- struct task_struct *task;
- int ret, i;
+ struct mtd_info *mtd;
+ int ret;
/* Register the notifier if/when the first device type is
registered, to prevent the link/init ordering from fucking
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) {
+ if (ret < 0) {
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);
- init_completion(&tr->blkcore_priv->thread_dead);
- init_waitqueue_head(&tr->blkcore_priv->thread_wq);
-
- 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_hardsect_size(tr->blkcore_priv->rq, tr->blksize);
- tr->blkshift = ffs(tr->blksize) - 1;
+ if (ret)
+ tr->major = ret;
- task = kthread_run(mtd_blktrans_thread, tr, "%sd", tr->name);
- if (IS_ERR(task)) {
- blk_cleanup_queue(tr->blkcore_priv->rq);
- unregister_blkdev(tr->major, tr->name);
- kfree(tr->blkcore_priv);
- mutex_unlock(&mtd_table_mutex);
- return PTR_ERR(task);
- }
+ tr->blkshift = ffs(tr->blksize) - 1;
INIT_LIST_HEAD(&tr->devs);
list_add(&tr->list, &blktrans_majors);
- for (i=0; i<MAX_MTD_DEVICES; i++) {
- if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT)
- tr->add_mtd(tr, mtd_table[i]);
- }
+ mtd_for_each_device(mtd)
+ if (mtd->type != MTD_ABSENT)
+ tr->add_mtd(tr, mtd);
mutex_unlock(&mtd_table_mutex);
-
return 0;
}
int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
{
- struct list_head *this, *next;
+ struct mtd_blktrans_dev *dev, *next;
mutex_lock(&mtd_table_mutex);
- /* Clean up the kernel thread */
- tr->blkcore_priv->exiting = 1;
- wake_up(&tr->blkcore_priv->thread_wq);
- wait_for_completion(&tr->blkcore_priv->thread_dead);
-
/* Remove it from the list of active majors */
list_del(&tr->list);
- list_for_each_safe(this, next, &tr->devs) {
- struct mtd_blktrans_dev *dev = list_entry(this, struct mtd_blktrans_dev, 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;
}