1 files changed, 152 insertions, 206 deletions

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 5073cbc796d8..28e09d080440 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -1,22 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Interface to Linux 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/kernel.h>
@@ -27,94 +13,87 @@
 #include <linux/mtd/blktrans.h>
 #include <linux/mtd/mtd.h>
 #include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 #include <linux/blkpg.h>
 #include <linux/spinlock.h>
 #include <linux/hdreg.h>
-#include <linux/init.h>
 #include <linux/mutex.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 #include "mtdcore.h"
 
 static LIST_HEAD(blktrans_majors);
-static DEFINE_MUTEX(blktrans_ref_mutex);
 
 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);
+	blk_mq_free_tag_set(dev->tag_set);
+	kfree(dev->tag_set);
 	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);
 }
 
 
-static int do_blktrans_request(struct mtd_blktrans_ops *tr,
+static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr,
 			       struct mtd_blktrans_dev *dev,
 			       struct request *req)
 {
+	struct req_iterator iter;
+	struct bio_vec bvec;
 	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 (req_op(req)) {
+	case REQ_OP_FLUSH:
+		if (tr->flush(dev))
+			return BLK_STS_IOERR;
+		return BLK_STS_OK;
+	case REQ_OP_DISCARD:
+		if (tr->discard(dev, block, nsect))
+			return BLK_STS_IOERR;
+		return BLK_STS_OK;
+	case REQ_OP_READ:
+		buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
+		for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
+			if (tr->readsect(dev, block, buf)) {
+				kunmap(bio_page(req->bio));
+				return BLK_STS_IOERR;
+			}
+		}
+		kunmap(bio_page(req->bio));
 
-	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:
+		rq_for_each_segment(bvec, req, iter)
+			flush_dcache_page(bvec.bv_page);
+		return BLK_STS_OK;
+	case REQ_OP_WRITE:
 		if (!tr->writesect)
-			return -EIO;
+			return BLK_STS_IOERR;
+
+		rq_for_each_segment(bvec, req, iter)
+			flush_dcache_page(bvec.bv_page);
 
-		rq_flush_dcache_pages(req);
-		for (; nsect > 0; nsect--, block++, buf += tr->blksize)
-			if (tr->writesect(dev, block, buf))
-				return -EIO;
-		return 0;
+		buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
+		for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
+			if (tr->writesect(dev, block, buf)) {
+				kunmap(bio_page(req->bio));
+				return BLK_STS_IOERR;
+			}
+		}
+		kunmap(bio_page(req->bio));
+		return BLK_STS_OK;
 	default:
-		printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
-		return -EIO;
+		return BLK_STS_IOERR;
 	}
 }
 
@@ -124,28 +103,39 @@ int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
 }
 EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
 
-static void mtd_blktrans_work(struct work_struct *work)
+static struct request *mtd_next_request(struct mtd_blktrans_dev *dev)
+{
+	struct request *rq;
+
+	rq = list_first_entry_or_null(&dev->rq_list, struct request, queuelist);
+	if (rq) {
+		list_del_init(&rq->queuelist);
+		blk_mq_start_request(rq);
+		return rq;
+	}
+
+	return NULL;
+}
+
+static void mtd_blktrans_work(struct mtd_blktrans_dev *dev)
+	__releases(&dev->queue_lock)
+	__acquires(&dev->queue_lock)
 {
-	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 (1) {
-		int res;
+		blk_status_t res;
 
 		dev->bg_stop = false;
-		if (!req && !(req = blk_fetch_request(rq))) {
+		if (!req && !(req = mtd_next_request(dev))) {
 			if (tr->background && !background_done) {
-				spin_unlock_irq(rq->queue_lock);
+				spin_unlock_irq(&dev->queue_lock);
 				mutex_lock(&dev->lock);
 				tr->background(dev);
 				mutex_unlock(&dev->lock);
-				spin_lock_irq(rq->queue_lock);
+				spin_lock_irq(&dev->queue_lock);
 				/*
 				 * Do background processing just once per idle
 				 * period.
@@ -156,54 +146,54 @@ static void mtd_blktrans_work(struct work_struct *work)
 			break;
 		}
 
-		spin_unlock_irq(rq->queue_lock);
+		spin_unlock_irq(&dev->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))
+		if (!blk_update_request(req, res, blk_rq_cur_bytes(req))) {
+			__blk_mq_end_request(req, res);
 			req = NULL;
+		}
 
 		background_done = 0;
+		cond_resched();
+		spin_lock_irq(&dev->queue_lock);
 	}
-
-	if (req)
-		__blk_end_request_all(req, -EIO);
-
-	spin_unlock_irq(rq->queue_lock);
 }
 
-static void mtd_blktrans_request(struct request_queue *rq)
+static blk_status_t mtd_queue_rq(struct blk_mq_hw_ctx *hctx,
+				 const struct blk_mq_queue_data *bd)
 {
 	struct mtd_blktrans_dev *dev;
-	struct request *req = NULL;
 
-	dev = rq->queuedata;
+	dev = hctx->queue->queuedata;
+	if (!dev) {
+		blk_mq_start_request(bd->rq);
+		return BLK_STS_IOERR;
+	}
+
+	spin_lock_irq(&dev->queue_lock);
+	list_add_tail(&bd->rq->queuelist, &dev->rq_list);
+	mtd_blktrans_work(dev);
+	spin_unlock_irq(&dev->queue_lock);
 
-	if (!dev)
-		while ((req = blk_fetch_request(rq)) != NULL)
-			__blk_end_request_all(req, -ENODEV);
-	else
-		queue_work(dev->wq, &dev->work);
+	return BLK_STS_OK;
 }
 
-static int blktrans_open(struct block_device *bdev, fmode_t mode)
+static int blktrans_open(struct gendisk *disk, blk_mode_t mode)
 {
-	struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
+	struct mtd_blktrans_dev *dev = disk->private_data;
 	int ret = 0;
 
-	if (!dev)
-		return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
+	kref_get(&dev->ref);
 
 	mutex_lock(&dev->lock);
 
 	if (dev->open)
 		goto unlock;
 
-	kref_get(&dev->ref);
 	__module_get(dev->tr->owner);
 
 	if (!dev->mtd)
@@ -218,12 +208,11 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
 	ret = __get_mtd_device(dev->mtd);
 	if (ret)
 		goto error_release;
-	dev->file_mode = mode;
+	dev->writable = mode & BLK_OPEN_WRITE;
 
 unlock:
 	dev->open++;
 	mutex_unlock(&dev->lock);
-	blktrans_dev_put(dev);
 	return ret;
 
 error_release:
@@ -231,25 +220,20 @@ error_release:
 		dev->tr->release(dev);
 error_put:
 	module_put(dev->tr->owner);
-	kref_put(&dev->ref, blktrans_dev_release);
 	mutex_unlock(&dev->lock);
 	blktrans_dev_put(dev);
 	return ret;
 }
 
-static void blktrans_release(struct gendisk *disk, fmode_t mode)
+static void blktrans_release(struct gendisk *disk)
 {
-	struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
-
-	if (!dev)
-		return;
+	struct mtd_blktrans_dev *dev = disk->private_data;
 
 	mutex_lock(&dev->lock);
 
 	if (--dev->open)
 		goto unlock;
 
-	kref_put(&dev->ref, blktrans_dev_release);
 	module_put(dev->tr->owner);
 
 	if (dev->mtd) {
@@ -262,50 +246,19 @@ unlock:
 	blktrans_dev_put(dev);
 }
 
-static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+static int blktrans_getgeo(struct gendisk *disk, struct hd_geometry *geo)
 {
-	struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
+	struct mtd_blktrans_dev *dev = disk->private_data;
 	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;
+	ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENOTTY;
 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;
-
-	mutex_lock(&dev->lock);
-
-	if (!dev->mtd)
-		goto unlock;
-
-	switch (cmd) {
-	case BLKFLSBUF:
-		ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
-		break;
-	default:
-		ret = -ENOTTY;
-	}
-unlock:
-	mutex_unlock(&dev->lock);
-	blktrans_dev_put(dev);
 	return ret;
 }
 
@@ -313,24 +266,24 @@ static const struct block_device_operations mtd_block_ops = {
 	.owner		= THIS_MODULE,
 	.open		= blktrans_open,
 	.release	= blktrans_release,
-	.ioctl		= blktrans_ioctl,
 	.getgeo		= blktrans_getgeo,
 };
 
+static const struct blk_mq_ops mtd_mq_ops = {
+	.queue_rq	= mtd_queue_rq,
+};
+
 int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 {
 	struct mtd_blktrans_ops *tr = new->tr;
 	struct mtd_blktrans_dev *d;
+	struct queue_limits lim = { };
 	int last_devnum = -1;
 	struct gendisk *gd;
 	int ret;
 
-	if (mutex_trylock(&mtd_table_mutex)) {
-		mutex_unlock(&mtd_table_mutex);
-		BUG();
-	}
+	lockdep_assert_held(&mtd_table_mutex);
 
-	mutex_lock(&blktrans_ref_mutex);
 	list_for_each_entry(d, &tr->devs, list) {
 		if (new->devnum == -1) {
 			/* Use first free number */
@@ -342,7 +295,6 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 			}
 		} 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 */
@@ -360,34 +312,49 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 	 * 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;
-	}
+	    (tr->part_bits && new->devnum >= 27 * 26))
+		return ret;
 
 	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);
+	new->tag_set = kzalloc(sizeof(*new->tag_set), GFP_KERNEL);
+	if (!new->tag_set)
+		goto out_list_del;
 
-	if (!gd)
-		goto error2;
+	ret = blk_mq_alloc_sq_tag_set(new->tag_set, &mtd_mq_ops, 2,
+			BLK_MQ_F_BLOCKING);
+	if (ret)
+		goto out_kfree_tag_set;
+	
+	lim.logical_block_size = tr->blksize;
+	if (tr->discard)
+		lim.max_hw_discard_sectors = UINT_MAX;
+	if (tr->flush)
+		lim.features |= BLK_FEAT_WRITE_CACHE;
+
+	/* Create gendisk */
+	gd = blk_mq_alloc_disk(new->tag_set, &lim, new);
+	if (IS_ERR(gd)) {
+		ret = PTR_ERR(gd);
+		goto out_free_tag_set;
+	}
 
 	new->disk = gd;
+	new->rq = new->disk->queue;
 	gd->private_data = new;
 	gd->major = tr->major;
 	gd->first_minor = (new->devnum) << tr->part_bits;
+	gd->minors = 1 << tr->part_bits;
 	gd->fops = &mtd_block_ops;
 
-	if (tr->part_bits)
+	if (tr->part_bits) {
 		if (new->devnum < 26)
 			snprintf(gd->disk_name, sizeof(gd->disk_name),
 				 "%s%c", tr->name, 'a' + new->devnum);
@@ -396,44 +363,25 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 				 "%s%c%c", tr->name,
 				 'a' - 1 + new->devnum / 26,
 				 'a' + new->devnum % 26);
-	else
+	} else {
 		snprintf(gd->disk_name, sizeof(gd->disk_name),
 			 "%s%d", tr->name, new->devnum);
+		gd->flags |= GENHD_FL_NO_PART;
+	}
 
-	set_capacity(gd, (new->size * tr->blksize) >> 9);
+	set_capacity(gd, ((u64)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);
-
-	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;
-	}
-
+	INIT_LIST_HEAD(&new->rq_list);
 	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);
+	ret = device_add_disk(&new->mtd->dev, gd, NULL);
+	if (ret)
+		goto out_cleanup_disk;
 
 	if (new->disk_attributes) {
 		ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
@@ -441,24 +389,24 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
 		WARN_ON(ret);
 	}
 	return 0;
-error4:
-	blk_cleanup_queue(new->rq);
-error3:
+
+out_cleanup_disk:
 	put_disk(new->disk);
-error2:
+out_free_tag_set:
+	blk_mq_free_tag_set(new->tag_set);
+out_kfree_tag_set:
+	kfree(new->tag_set);
+out_list_del:
 	list_del(&new->list);
-error1:
 	return ret;
 }
 
 int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
 {
 	unsigned long flags;
+	unsigned int memflags;
 
-	if (mutex_trylock(&mtd_table_mutex)) {
-		mutex_unlock(&mtd_table_mutex);
-		BUG();
-	}
+	lockdep_assert_held(&mtd_table_mutex);
 
 	if (old->disk_attributes)
 		sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
@@ -467,15 +415,17 @@ int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
 	/* 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);
 
+	/* freeze+quiesce queue to ensure all requests are flushed */
+	memflags = blk_mq_freeze_queue(old->rq);
+	blk_mq_quiesce_queue(old->rq);
+	blk_mq_unquiesce_queue(old->rq);
+	blk_mq_unfreeze_queue(old->rq, memflags);
+
 	/* 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);
@@ -507,7 +457,7 @@ static void blktrans_notify_add(struct mtd_info *mtd)
 {
 	struct mtd_blktrans_ops *tr;
 
-	if (mtd->type == MTD_ABSENT)
+	if (mtd->type == MTD_ABSENT || mtd->type == MTD_UBIVOLUME)
 		return;
 
 	list_for_each_entry(tr, &blktrans_majors, list)
@@ -530,14 +480,10 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
 	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;
 	}
 
@@ -547,12 +493,12 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
 	tr->blkshift = ffs(tr->blksize) - 1;
 
 	INIT_LIST_HEAD(&tr->devs);
-	list_add(&tr->list, &blktrans_majors);
 
+	mutex_lock(&mtd_table_mutex);
+	list_add(&tr->list, &blktrans_majors);
 	mtd_for_each_device(mtd)
-		if (mtd->type != MTD_ABSENT)
+		if (mtd->type != MTD_ABSENT && mtd->type != MTD_UBIVOLUME)
 			tr->add_mtd(tr, mtd);
-
 	mutex_unlock(&mtd_table_mutex);
 	return 0;
 }
@@ -569,8 +515,8 @@ int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
 	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);
+	unregister_blkdev(tr->major, tr->name);
 
 	BUG_ON(!list_empty(&tr->devs));
 	return 0;