[PATCH 1/8] mtd_blkdevs: don't hold del_mtd_blktrans_dev in blktrans_{open, release}

Christoph Hellwig
2021-08-23T07:35:57Z

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>
---
drivers/mtd/mtd_blkdevs.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 44bea3f65060..6b81a1c9ccbe 100644
--- 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 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
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);
}

--
2.30.2