![Arnd Bergmann](/assets/img/avatar_default.png)
As a preparation for the removal of the big kernel lock in the block layer, this removes the BKL from the common ioctl handling code, moving it into every single driver still using it. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
548 lines
12 KiB
C
548 lines
12 KiB
C
/*
|
|
* (C) 2003 David Woodhouse <dwmw2@infradead.org>
|
|
*
|
|
* Interface to Linux 2.5 block layer for MTD 'translation layers'.
|
|
*
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/list.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mtd/blktrans.h>
|
|
#include <linux/mtd/mtd.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/blkpg.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/smp_lock.h>
|
|
#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);
|
|
|
|
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);
|
|
}
|
|
|
|
|
|
static int do_blktrans_request(struct mtd_blktrans_ops *tr,
|
|
struct mtd_blktrans_dev *dev,
|
|
struct request *req)
|
|
{
|
|
unsigned long block, nsect;
|
|
char *buf;
|
|
|
|
block = blk_rq_pos(req) << 9 >> tr->blkshift;
|
|
nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
|
|
|
|
buf = req->buffer;
|
|
|
|
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 (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 -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, 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_dev *dev = arg;
|
|
struct request_queue *rq = dev->rq;
|
|
struct request *req = NULL;
|
|
|
|
spin_lock_irq(rq->queue_lock);
|
|
|
|
while (!kthread_should_stop()) {
|
|
int res;
|
|
|
|
if (!req && !(req = blk_fetch_request(rq))) {
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
spin_unlock_irq(rq->queue_lock);
|
|
schedule();
|
|
spin_lock_irq(rq->queue_lock);
|
|
continue;
|
|
}
|
|
|
|
spin_unlock_irq(rq->queue_lock);
|
|
|
|
mutex_lock(&dev->lock);
|
|
res = do_blktrans_request(dev->tr, dev, req);
|
|
mutex_unlock(&dev->lock);
|
|
|
|
spin_lock_irq(rq->queue_lock);
|
|
|
|
if (!__blk_end_request_cur(req, res))
|
|
req = NULL;
|
|
}
|
|
|
|
if (req)
|
|
__blk_end_request_all(req, -EIO);
|
|
|
|
spin_unlock_irq(rq->queue_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mtd_blktrans_request(struct request_queue *rq)
|
|
{
|
|
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 = blktrans_dev_get(bdev->bd_disk);
|
|
int ret;
|
|
|
|
if (!dev)
|
|
return -ERESTARTSYS;
|
|
|
|
mutex_lock(&dev->lock);
|
|
|
|
if (!dev->mtd) {
|
|
ret = -ENXIO;
|
|
goto unlock;
|
|
}
|
|
|
|
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);
|
|
return ret;
|
|
}
|
|
|
|
static int blktrans_release(struct gendisk *disk, fmode_t mode)
|
|
{
|
|
struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
|
|
int ret = -ENXIO;
|
|
|
|
if (!dev)
|
|
return ret;
|
|
|
|
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);
|
|
return ret;
|
|
}
|
|
|
|
static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
|
|
{
|
|
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;
|
|
|
|
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 = 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:
|
|
ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
|
|
default:
|
|
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,
|
|
.ioctl = blktrans_ioctl,
|
|
.getgeo = blktrans_getgeo,
|
|
};
|
|
|
|
int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
|
|
{
|
|
struct mtd_blktrans_ops *tr = new->tr;
|
|
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 */
|
|
if (d->devnum != last_devnum+1) {
|
|
/* Found a free devnum. Plug it in here */
|
|
new->devnum = last_devnum+1;
|
|
list_add_tail(&new->list, &d->list);
|
|
goto added;
|
|
}
|
|
} 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 */
|
|
list_add_tail(&new->list, &d->list);
|
|
goto added;
|
|
}
|
|
last_devnum = d->devnum;
|
|
}
|
|
|
|
ret = -EBUSY;
|
|
if (new->devnum == -1)
|
|
new->devnum = last_devnum+1;
|
|
|
|
/* 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)
|
|
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;
|
|
|
|
if (tr->part_bits)
|
|
if (new->devnum < 26)
|
|
snprintf(gd->disk_name, sizeof(gd->disk_name),
|
|
"%s%c", tr->name, 'a' + new->devnum);
|
|
else
|
|
snprintf(gd->disk_name, sizeof(gd->disk_name),
|
|
"%s%c%c", tr->name,
|
|
'a' - 1 + new->devnum / 26,
|
|
'a' + new->devnum % 26);
|
|
else
|
|
snprintf(gd->disk_name, sizeof(gd->disk_name),
|
|
"%s%d", tr->name, new->devnum);
|
|
|
|
set_capacity(gd, (new->size * tr->blksize) >> 9);
|
|
|
|
/* 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)
|
|
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:
|
|
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();
|
|
}
|
|
|
|
/* Stop new requests to arrive */
|
|
del_gendisk(old->disk);
|
|
|
|
if (old->disk_attributes)
|
|
sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
|
|
old->disk_attributes);
|
|
|
|
/* 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);
|
|
|
|
/* At that point, we don't touch the mtd anymore */
|
|
old->mtd = NULL;
|
|
|
|
mutex_unlock(&old->lock);
|
|
blktrans_dev_put(old);
|
|
return 0;
|
|
}
|
|
|
|
static void blktrans_notify_remove(struct mtd_info *mtd)
|
|
{
|
|
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 mtd_blktrans_ops *tr;
|
|
|
|
if (mtd->type == MTD_ABSENT)
|
|
return;
|
|
|
|
list_for_each_entry(tr, &blktrans_majors, list)
|
|
tr->add_mtd(tr, mtd);
|
|
}
|
|
|
|
static struct mtd_notifier blktrans_notifier = {
|
|
.add = blktrans_notify_add,
|
|
.remove = blktrans_notify_remove,
|
|
};
|
|
|
|
int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
|
|
{
|
|
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
|
|
us over. */
|
|
if (!blktrans_notifier.list.next)
|
|
register_mtd_user(&blktrans_notifier);
|
|
|
|
|
|
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);
|
|
mutex_unlock(&mtd_table_mutex);
|
|
return ret;
|
|
}
|
|
|
|
tr->blkshift = ffs(tr->blksize) - 1;
|
|
|
|
INIT_LIST_HEAD(&tr->devs);
|
|
list_add(&tr->list, &blktrans_majors);
|
|
|
|
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 mtd_blktrans_dev *dev, *next;
|
|
|
|
mutex_lock(&mtd_table_mutex);
|
|
|
|
/* 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);
|
|
|
|
unregister_blkdev(tr->major, tr->name);
|
|
mutex_unlock(&mtd_table_mutex);
|
|
|
|
BUG_ON(!list_empty(&tr->devs));
|
|
return 0;
|
|
}
|
|
|
|
static void __exit mtd_blktrans_exit(void)
|
|
{
|
|
/* No race here -- if someone's currently in register_mtd_blktrans
|
|
we're screwed anyway. */
|
|
if (blktrans_notifier.list.next)
|
|
unregister_mtd_user(&blktrans_notifier);
|
|
}
|
|
|
|
module_exit(mtd_blktrans_exit);
|
|
|
|
EXPORT_SYMBOL_GPL(register_mtd_blktrans);
|
|
EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
|
|
EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
|
|
EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
|
|
|
|
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");
|