/*
- * (C) 2003 David Woodhouse <dwmw2@infradead.org>
+ * Interface to Linux block layer for MTD 'translation layers'.
*
- * Interface to Linux 2.5 block layer for MTD 'translation layers'.
+ * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * 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/mtd/mtd.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
-#include <linux/freezer.h>
#include <linux/spinlock.h>
+#include <linux/smp_lock.h>
#include <linux/hdreg.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include "mtdcore.h"
static LIST_HEAD(blktrans_majors);
+static DEFINE_MUTEX(blktrans_ref_mutex);
+
+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;
+}
+
+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 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,
buf = req->buffer;
- if (!blk_fs_request(req))
+ if (req->cmd_type != REQ_TYPE_FS)
return -EIO;
if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
get_capacity(req->rq_disk))
return -EIO;
- if (blk_discard_rq(req))
+ if (req->cmd_flags & REQ_DISCARD)
return tr->discard(dev, block, nsect);
switch(rq_data_dir(req)) {
//for (; nsect > 0; nsect--, block++, buf += tr->blksize)
if (tr->readsect(dev, block,nsect, buf))
return -EIO;
+ rq_flush_dcache_pages(req);
return 0;
-
case WRITE:
if (!tr->writesect)
return -EIO;
+ rq_flush_dcache_pages(req);
//for (; nsect > 0; nsect--, block++, buf += tr->blksize)
if (tr->writesect(dev, block,nsect, buf))
return -EIO;
return 0;
-
default:
printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
return -EIO;
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;
- /* we might get involved when memory gets low, so use PF_MEMALLOC */
- current->flags |= PF_MEMALLOC;
-
spin_lock_irq(rq->queue_lock);
while (!kthread_should_stop()) {
- struct mtd_blktrans_dev *dev;
int res;
if (!req && !(req = blk_fetch_request(rq))) {
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);
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;
+ struct request *req = NULL;
+ dev = rq->queuedata;
+
+ if (!dev)
+ while ((req = blk_fetch_request(rq)) != NULL)
+ __blk_end_request_all(req, -ENODEV);
+ else
+ wake_up_process(dev->thread);
+}
static int blktrans_open(struct block_device *bdev, fmode_t mode)
{
- struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
- struct mtd_blktrans_ops *tr = dev->tr;
- int ret = -ENODEV;
-
- if (!get_mtd_device(NULL, dev->mtd->index))
- goto out;
-
- if (!try_module_get(tr->owner))
- goto out_tr;
-
- /* 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++;
-
- ret = 0;
- if (tr->open && (ret = tr->open(dev))) {
- dev->mtd->usecount--;
- put_mtd_device(dev->mtd);
- out_tr:
- module_put(tr->owner);
+ struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
+ int ret;
+
+ if (!dev)
+ return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
+
+ lock_kernel();
+ mutex_lock(&dev->lock);
+
+ if (!dev->mtd) {
+ ret = -ENXIO;
+ goto unlock;
}
- out:
+
+ ret = !dev->open++ && dev->tr->open ? dev->tr->open(dev) : 0;
+
+ /* Take another reference on the device so it won't go away till
+ last release */
+ if (!ret)
+ kref_get(&dev->ref);
+unlock:
+ mutex_unlock(&dev->lock);
+ blktrans_dev_put(dev);
+ unlock_kernel();
return ret;
}
static int blktrans_release(struct gendisk *disk, fmode_t mode)
{
- struct mtd_blktrans_dev *dev = disk->private_data;
- struct mtd_blktrans_ops *tr = dev->tr;
- int ret = 0;
+ struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
+ int ret = -ENXIO;
- if (tr->release)
- ret = tr->release(dev);
+ if (!dev)
+ return ret;
- if (!ret) {
- dev->mtd->usecount--;
- put_mtd_device(dev->mtd);
- module_put(tr->owner);
- }
+ lock_kernel();
+ mutex_lock(&dev->lock);
+
+ /* Release one reference, we sure its not the last one here*/
+ kref_put(&dev->ref, blktrans_dev_release);
+
+ if (!dev->mtd)
+ goto unlock;
+ ret = !--dev->open && dev->tr->release ? dev->tr->release(dev) : 0;
+unlock:
+ mutex_unlock(&dev->lock);
+ blktrans_dev_put(dev);
+ unlock_kernel();
return ret;
}
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->tr->getgeo)
- return dev->tr->getgeo(dev, geo);
- return -ENOTTY;
+ if (!dev)
+ return ret;
+
+ mutex_lock(&dev->lock);
+
+ 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 block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
- struct mtd_blktrans_dev *dev = 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;
+
+ lock_kernel();
+ 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);
+ unlock_kernel();
+ blktrans_dev_put(dev);
+ return ret;
}
static const struct block_device_operations mtd_blktrans_ops = {
.owner = THIS_MODULE,
.open = blktrans_open,
.release = blktrans_release,
- .locked_ioctl = blktrans_ioctl,
+ .ioctl = blktrans_ioctl,
.getgeo = blktrans_getgeo,
};
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);
BUG();
}
+ mutex_lock(&blktrans_ref_mutex);
list_for_each_entry(d, &tr->devs, list) {
if (new->devnum == -1) {
/* Use first free number */
}
} 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;
}
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;
//set_capacity(gd, (new->size * tr->blksize) >> 9);
set_capacity(gd, (new->size >> 9) * tr->blksize); //modify by zyf for cap>=4GB 20110120
- 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;
+
+ __get_mtd_device(new->mtd);
+ __module_get(tr->owner);
+
+ /* 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)
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:
+ module_put(tr->owner);
+ __put_mtd_device(new->mtd);
+ 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)
{
+ 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 the thread */
+ kthread_stop(old->thread);
+
+ /* 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);
+
+ /* Ask trans driver for release to the mtd device */
+ mutex_lock(&old->lock);
+ if (old->open && old->tr->release) {
+ old->tr->release(old);
+ old->open = 0;
+ }
+
+ __put_mtd_device(old->mtd);
+ module_put(old->tr->owner);
- del_gendisk(old->blkcore_priv);
- put_disk(old->blkcore_priv);
+ /* At that point, we don't touch the mtd anymore */
+ old->mtd = NULL;
+ mutex_unlock(&old->lock);
+ blktrans_dev_put(old);
return 0;
}
int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
{
- 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);
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)) {
- int 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);
- 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;
}
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;
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff