mtd_blkdevs: don't hold del_mtd_blktrans_dev in blktrans_{open, release}

There is nothing that this protects against except for slightly reducing
the window when new opens can appear just before calling del_gendisk.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210823073359.705281-2-hch@lst.de

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 6ce4bc5..94d42ba 100644 (file)
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -207,7 +207,6 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
        if (!dev)
                return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
 
-       mutex_lock(&mtd_table_mutex);
        mutex_lock(&dev->lock);
 
        if (dev->open)
@@ -233,7 +232,6 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
 unlock:
        dev->open++;
        mutex_unlock(&dev->lock);
-       mutex_unlock(&mtd_table_mutex);
        blktrans_dev_put(dev);
        return ret;
 
@@ -244,7 +242,6 @@ error_put:
        module_put(dev->tr->owner);
        kref_put(&dev->ref, blktrans_dev_release);
        mutex_unlock(&dev->lock);
-       mutex_unlock(&mtd_table_mutex);
        blktrans_dev_put(dev);
        return ret;
 }
@@ -256,7 +253,6 @@ static void blktrans_release(struct gendisk *disk, fmode_t mode)
        if (!dev)
                return;
 
-       mutex_lock(&mtd_table_mutex);
        mutex_lock(&dev->lock);
 
        if (--dev->open)
@@ -272,7 +268,6 @@ static void blktrans_release(struct gendisk *disk, fmode_t mode)
        }
 unlock:
        mutex_unlock(&dev->lock);
-       mutex_unlock(&mtd_table_mutex);
        blktrans_dev_put(dev);
 }