c4a3f13c2a
In commit 5018393625
("mtd: blktrans: change blktrans_getgeo return
value") we fixed the problem that ioctl(HDIO_GETGEO) might return 0
(success) for mtdblock devices which did not implement the feature and
would leave a blank (zero) result.
But now, let's get the error code right. Other code paths on this ioctl
tend to use -ENOTTY to notify the user that the ioctl() is not supported
for the device, so let's use that instead of -EOPNOTSUPP.
Suggested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
604 lines
13 KiB
C
604 lines
13 KiB
C
/*
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* Interface to Linux block layer for MTD 'translation layers'.
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*
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* Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/fs.h>
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#include <linux/mtd/blktrans.h>
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#include <linux/mtd/mtd.h>
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#include <linux/blkdev.h>
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#include <linux/blkpg.h>
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#include <linux/spinlock.h>
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#include <linux/hdreg.h>
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#include <linux/mutex.h>
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#include <asm/uaccess.h>
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#include "mtdcore.h"
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static LIST_HEAD(blktrans_majors);
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static DEFINE_MUTEX(blktrans_ref_mutex);
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static void blktrans_dev_release(struct kref *kref)
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{
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struct mtd_blktrans_dev *dev =
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container_of(kref, struct mtd_blktrans_dev, ref);
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dev->disk->private_data = NULL;
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blk_cleanup_queue(dev->rq);
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put_disk(dev->disk);
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list_del(&dev->list);
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kfree(dev);
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}
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static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk)
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{
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struct mtd_blktrans_dev *dev;
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mutex_lock(&blktrans_ref_mutex);
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dev = disk->private_data;
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if (!dev)
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goto unlock;
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kref_get(&dev->ref);
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unlock:
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mutex_unlock(&blktrans_ref_mutex);
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return dev;
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}
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static void blktrans_dev_put(struct mtd_blktrans_dev *dev)
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{
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mutex_lock(&blktrans_ref_mutex);
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kref_put(&dev->ref, blktrans_dev_release);
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mutex_unlock(&blktrans_ref_mutex);
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}
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static int do_blktrans_request(struct mtd_blktrans_ops *tr,
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struct mtd_blktrans_dev *dev,
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struct request *req)
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{
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unsigned long block, nsect;
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char *buf;
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block = blk_rq_pos(req) << 9 >> tr->blkshift;
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nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
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buf = bio_data(req->bio);
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if (req->cmd_type != REQ_TYPE_FS)
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return -EIO;
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if (req->cmd_flags & REQ_FLUSH)
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return tr->flush(dev);
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if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
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get_capacity(req->rq_disk))
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return -EIO;
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if (req->cmd_flags & REQ_DISCARD)
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return tr->discard(dev, block, nsect);
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switch(rq_data_dir(req)) {
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case READ:
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for (; nsect > 0; nsect--, block++, buf += tr->blksize)
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if (tr->readsect(dev, block, buf))
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return -EIO;
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rq_flush_dcache_pages(req);
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return 0;
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case WRITE:
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if (!tr->writesect)
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return -EIO;
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rq_flush_dcache_pages(req);
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for (; nsect > 0; nsect--, block++, buf += tr->blksize)
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if (tr->writesect(dev, block, buf))
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return -EIO;
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return 0;
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default:
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printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
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return -EIO;
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}
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}
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int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
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{
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return dev->bg_stop;
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}
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EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
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static void mtd_blktrans_work(struct work_struct *work)
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{
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struct mtd_blktrans_dev *dev =
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container_of(work, struct mtd_blktrans_dev, work);
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struct mtd_blktrans_ops *tr = dev->tr;
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struct request_queue *rq = dev->rq;
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struct request *req = NULL;
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int background_done = 0;
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spin_lock_irq(rq->queue_lock);
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while (1) {
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int res;
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dev->bg_stop = false;
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if (!req && !(req = blk_fetch_request(rq))) {
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if (tr->background && !background_done) {
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spin_unlock_irq(rq->queue_lock);
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mutex_lock(&dev->lock);
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tr->background(dev);
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mutex_unlock(&dev->lock);
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spin_lock_irq(rq->queue_lock);
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/*
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* Do background processing just once per idle
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* period.
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*/
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background_done = !dev->bg_stop;
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continue;
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}
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break;
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}
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spin_unlock_irq(rq->queue_lock);
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mutex_lock(&dev->lock);
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res = do_blktrans_request(dev->tr, dev, req);
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mutex_unlock(&dev->lock);
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spin_lock_irq(rq->queue_lock);
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if (!__blk_end_request_cur(req, res))
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req = NULL;
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background_done = 0;
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}
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spin_unlock_irq(rq->queue_lock);
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}
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static void mtd_blktrans_request(struct request_queue *rq)
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{
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struct mtd_blktrans_dev *dev;
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struct request *req = NULL;
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dev = rq->queuedata;
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if (!dev)
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while ((req = blk_fetch_request(rq)) != NULL)
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__blk_end_request_all(req, -ENODEV);
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else
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queue_work(dev->wq, &dev->work);
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}
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static int blktrans_open(struct block_device *bdev, fmode_t mode)
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{
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struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
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int ret = 0;
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if (!dev)
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return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
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mutex_lock(&dev->lock);
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mutex_lock(&mtd_table_mutex);
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if (dev->open)
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goto unlock;
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kref_get(&dev->ref);
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__module_get(dev->tr->owner);
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if (!dev->mtd)
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goto unlock;
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if (dev->tr->open) {
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ret = dev->tr->open(dev);
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if (ret)
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goto error_put;
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}
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ret = __get_mtd_device(dev->mtd);
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if (ret)
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goto error_release;
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dev->file_mode = mode;
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unlock:
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dev->open++;
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mutex_unlock(&mtd_table_mutex);
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mutex_unlock(&dev->lock);
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blktrans_dev_put(dev);
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return ret;
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error_release:
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if (dev->tr->release)
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dev->tr->release(dev);
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error_put:
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module_put(dev->tr->owner);
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kref_put(&dev->ref, blktrans_dev_release);
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mutex_unlock(&mtd_table_mutex);
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mutex_unlock(&dev->lock);
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blktrans_dev_put(dev);
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return ret;
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}
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static void blktrans_release(struct gendisk *disk, fmode_t mode)
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{
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struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
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if (!dev)
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return;
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mutex_lock(&dev->lock);
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mutex_lock(&mtd_table_mutex);
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if (--dev->open)
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goto unlock;
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kref_put(&dev->ref, blktrans_dev_release);
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module_put(dev->tr->owner);
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if (dev->mtd) {
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if (dev->tr->release)
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dev->tr->release(dev);
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__put_mtd_device(dev->mtd);
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}
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unlock:
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mutex_unlock(&mtd_table_mutex);
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mutex_unlock(&dev->lock);
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blktrans_dev_put(dev);
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}
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static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
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{
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struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
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int ret = -ENXIO;
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if (!dev)
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return ret;
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mutex_lock(&dev->lock);
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if (!dev->mtd)
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goto unlock;
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ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY;
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unlock:
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mutex_unlock(&dev->lock);
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blktrans_dev_put(dev);
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return ret;
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}
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static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
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unsigned int cmd, unsigned long arg)
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{
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struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
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int ret = -ENXIO;
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if (!dev)
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return ret;
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mutex_lock(&dev->lock);
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if (!dev->mtd)
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goto unlock;
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switch (cmd) {
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case BLKFLSBUF:
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ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
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break;
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default:
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ret = -ENOTTY;
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}
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unlock:
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mutex_unlock(&dev->lock);
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blktrans_dev_put(dev);
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return ret;
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}
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static const struct block_device_operations mtd_block_ops = {
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.owner = THIS_MODULE,
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.open = blktrans_open,
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.release = blktrans_release,
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.ioctl = blktrans_ioctl,
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.getgeo = blktrans_getgeo,
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};
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int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
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{
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struct mtd_blktrans_ops *tr = new->tr;
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struct mtd_blktrans_dev *d;
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int last_devnum = -1;
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struct gendisk *gd;
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int ret;
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if (mutex_trylock(&mtd_table_mutex)) {
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mutex_unlock(&mtd_table_mutex);
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BUG();
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}
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mutex_lock(&blktrans_ref_mutex);
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list_for_each_entry(d, &tr->devs, list) {
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if (new->devnum == -1) {
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/* Use first free number */
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if (d->devnum != last_devnum+1) {
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/* Found a free devnum. Plug it in here */
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new->devnum = last_devnum+1;
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list_add_tail(&new->list, &d->list);
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goto added;
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}
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} else if (d->devnum == new->devnum) {
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/* Required number taken */
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mutex_unlock(&blktrans_ref_mutex);
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return -EBUSY;
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} else if (d->devnum > new->devnum) {
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/* Required number was free */
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list_add_tail(&new->list, &d->list);
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goto added;
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}
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last_devnum = d->devnum;
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}
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ret = -EBUSY;
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if (new->devnum == -1)
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new->devnum = last_devnum+1;
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/* Check that the device and any partitions will get valid
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* minor numbers and that the disk naming code below can cope
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* with this number. */
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if (new->devnum > (MINORMASK >> tr->part_bits) ||
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(tr->part_bits && new->devnum >= 27 * 26)) {
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mutex_unlock(&blktrans_ref_mutex);
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goto error1;
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}
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list_add_tail(&new->list, &tr->devs);
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added:
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mutex_unlock(&blktrans_ref_mutex);
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mutex_init(&new->lock);
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kref_init(&new->ref);
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if (!tr->writesect)
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new->readonly = 1;
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/* Create gendisk */
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ret = -ENOMEM;
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gd = alloc_disk(1 << tr->part_bits);
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if (!gd)
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goto error2;
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new->disk = gd;
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gd->private_data = new;
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gd->major = tr->major;
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gd->first_minor = (new->devnum) << tr->part_bits;
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gd->fops = &mtd_block_ops;
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if (tr->part_bits)
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if (new->devnum < 26)
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snprintf(gd->disk_name, sizeof(gd->disk_name),
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"%s%c", tr->name, 'a' + new->devnum);
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else
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snprintf(gd->disk_name, sizeof(gd->disk_name),
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"%s%c%c", tr->name,
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'a' - 1 + new->devnum / 26,
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'a' + new->devnum % 26);
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else
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snprintf(gd->disk_name, sizeof(gd->disk_name),
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"%s%d", tr->name, new->devnum);
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set_capacity(gd, (new->size * tr->blksize) >> 9);
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/* Create the request queue */
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spin_lock_init(&new->queue_lock);
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new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);
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if (!new->rq)
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goto error3;
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if (tr->flush)
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blk_queue_flush(new->rq, REQ_FLUSH);
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new->rq->queuedata = new;
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blk_queue_logical_block_size(new->rq, tr->blksize);
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queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq);
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queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, new->rq);
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if (tr->discard) {
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queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq);
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new->rq->limits.max_discard_sectors = UINT_MAX;
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}
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gd->queue = new->rq;
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/* Create processing workqueue */
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new->wq = alloc_workqueue("%s%d", 0, 0,
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tr->name, new->mtd->index);
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if (!new->wq)
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goto error4;
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INIT_WORK(&new->work, mtd_blktrans_work);
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gd->driverfs_dev = &new->mtd->dev;
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if (new->readonly)
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set_disk_ro(gd, 1);
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add_disk(gd);
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if (new->disk_attributes) {
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ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
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new->disk_attributes);
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WARN_ON(ret);
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}
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return 0;
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error4:
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blk_cleanup_queue(new->rq);
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error3:
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put_disk(new->disk);
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error2:
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list_del(&new->list);
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error1:
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return ret;
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}
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int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
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{
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unsigned long flags;
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if (mutex_trylock(&mtd_table_mutex)) {
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mutex_unlock(&mtd_table_mutex);
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BUG();
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}
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if (old->disk_attributes)
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sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
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old->disk_attributes);
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/* Stop new requests to arrive */
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del_gendisk(old->disk);
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/* Stop workqueue. This will perform any pending request. */
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destroy_workqueue(old->wq);
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/* Kill current requests */
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spin_lock_irqsave(&old->queue_lock, flags);
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old->rq->queuedata = NULL;
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blk_start_queue(old->rq);
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spin_unlock_irqrestore(&old->queue_lock, flags);
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/* If the device is currently open, tell trans driver to close it,
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then put mtd device, and don't touch it again */
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mutex_lock(&old->lock);
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if (old->open) {
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if (old->tr->release)
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old->tr->release(old);
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__put_mtd_device(old->mtd);
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}
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old->mtd = NULL;
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mutex_unlock(&old->lock);
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blktrans_dev_put(old);
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return 0;
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}
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static void blktrans_notify_remove(struct mtd_info *mtd)
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{
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struct mtd_blktrans_ops *tr;
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struct mtd_blktrans_dev *dev, *next;
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list_for_each_entry(tr, &blktrans_majors, list)
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list_for_each_entry_safe(dev, next, &tr->devs, list)
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if (dev->mtd == mtd)
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tr->remove_dev(dev);
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}
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static void blktrans_notify_add(struct mtd_info *mtd)
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{
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struct mtd_blktrans_ops *tr;
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if (mtd->type == MTD_ABSENT)
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return;
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list_for_each_entry(tr, &blktrans_majors, list)
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tr->add_mtd(tr, mtd);
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}
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static struct mtd_notifier blktrans_notifier = {
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.add = blktrans_notify_add,
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.remove = blktrans_notify_remove,
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};
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int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
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{
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struct mtd_info *mtd;
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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 < 0) {
|
|
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;
|
|
}
|
|
|
|
if (ret)
|
|
tr->major = 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'");
|