Commit 560a3915 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Miquel Raynal
Browse files

mtd_blkdevs: remove blktrans_ref_mutex 



blktrans_ref_mutex is not actually needed.  The kref is serialized
internally, and devnum assignment in add_mtd_blktrans_dev happens before
the disk is added and thus any of the block_device_operations methods
otherwise using it are called.  It  is also already serialized by the
global mtd_table_mutex.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210823073359.705281-7-hch@lst.de
parent 89843828

drivers/mtd/mtd_blkdevs.c

+1 −12
Original line number Diff line number Diff line
@@ -23,7 +23,6 @@ 
#include "mtdcore.h"



static LIST_HEAD(blktrans_majors);

static DEFINE_MUTEX(blktrans_ref_mutex);



static void blktrans_dev_release(struct kref *kref)

{
@@ -41,18 +40,13 @@ static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk) 
{

	struct mtd_blktrans_dev *dev = disk->private_data;



	mutex_lock(&blktrans_ref_mutex);

	kref_get(&dev->ref);

	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);

}
@@ -299,7 +293,6 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) 


	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 */
@@ -311,7 +304,6 @@ 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 */
@@ -329,14 +321,11 @@ 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);

	    (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);