On 8/20/21 8:08 AM, Christoph Hellwig wrote:
Please try the patch below:
---
From 7609266da56160d211662cd2fbe26570aad11b15 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@xxxxxx>
Date: Fri, 20 Aug 2021 17:00:11 +0200
Subject: 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.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
A cautious
Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Cautious because -next is a bit broken right now and I can not run a complete
test for all images.
Guenter
---
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);
}
