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From: Christoph Hellwig <hch@lst.de>
To: Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>
Cc: Guenter Roeck <linux@roeck-us.net>, linux-mtd@lists.infradead.org
Subject: [PATCH 1/8] mtd_blkdevs: don't hold del_mtd_blktrans_dev in blktrans_{open, release}
Date: Mon, 23 Aug 2021 09:33:52 +0200	[thread overview]
Message-ID: <20210823073359.705281-2-hch@lst.de> (raw)
In-Reply-To: <20210823073359.705281-1-hch@lst.de>

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


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  reply	other threads:[~2021-08-23  7:35 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-23  7:33 mtd locking fix and cleanups Christoph Hellwig
2021-08-23  7:33 ` Christoph Hellwig [this message]
2021-08-23  8:33   ` [PATCH 1/8] mtd_blkdevs: don't hold del_mtd_blktrans_dev in blktrans_{open, release} Miquel Raynal
2021-08-23  7:33 ` [PATCH 2/8] mtd_blkdevs: use lockdep_assert_held Christoph Hellwig
2021-08-23  8:33   ` Miquel Raynal
2021-08-23  7:33 ` [PATCH 3/8] mtd/ftl: don't cast away the type when calling add_mtd_blktrans_dev Christoph Hellwig
2021-08-23  8:33   ` Miquel Raynal
2021-08-23  7:33 ` [PATCH 4/8] mtd/rfd_ftl: " Christoph Hellwig
2021-08-23  8:33   ` Miquel Raynal
2021-08-23  7:33 ` [PATCH 5/8] mtd_blkdevs: simplify blktrans_dev_get Christoph Hellwig
2021-08-23  8:33   ` Miquel Raynal
2021-08-23  7:33 ` [PATCH 6/8] mtd_blkdevs: remove blktrans_ref_mutex Christoph Hellwig
2021-08-23  8:33   ` Miquel Raynal
2021-08-23  7:33 ` [PATCH 7/8] mtd_blkdevs: simplify blktrans_getgeo Christoph Hellwig
2021-08-23  8:33   ` Miquel Raynal
2021-08-23  7:33 ` [PATCH 8/8] mtd_blkdevs: simplify the refcounting in blktrans_{open, release} Christoph Hellwig
2021-08-23  8:33   ` Miquel Raynal
2021-08-23  8:30 ` mtd locking fix and cleanups Miquel Raynal

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