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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
        Jens Axboe <axboe@kernel.dk>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 0759/1017] memstick/mspro_block: fix handling of read-only devices
Date:   Tue,  5 Apr 2022 09:27:52 +0200
Message-Id: <20220405070416.789172716@linuxfoundation.org>
In-Reply-To: <20220405070354.155796697@linuxfoundation.org>
References: <20220405070354.155796697@linuxfoundation.org>
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From: Christoph Hellwig <hch@lst.de>

[ Upstream commit 6dab421bfe06a59bf8f212a72e34673e8acf2018 ]

Use set_disk_ro to propagate the read-only state to the block layer
instead of checking for it in ->open and leaking a reference in case
of a read-only device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220215094514.3828912-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/memstick/core/mspro_block.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/memstick/core/mspro_block.c b/drivers/memstick/core/mspro_block.c
index c0450397b673..7ea312f0840e 100644
--- a/drivers/memstick/core/mspro_block.c
+++ b/drivers/memstick/core/mspro_block.c
@@ -186,13 +186,8 @@ static int mspro_block_bd_open(struct block_device *bdev, fmode_t mode)
 
 	mutex_lock(&mspro_block_disk_lock);
 
-	if (msb && msb->card) {
+	if (msb && msb->card)
 		msb->usage_count++;
-		if ((mode & FMODE_WRITE) && msb->read_only)
-			rc = -EROFS;
-		else
-			rc = 0;
-	}
 
 	mutex_unlock(&mspro_block_disk_lock);
 
@@ -1239,6 +1234,9 @@ static int mspro_block_init_disk(struct memstick_dev *card)
 	set_capacity(msb->disk, capacity);
 	dev_dbg(&card->dev, "capacity set %ld\n", capacity);
 
+	if (msb->read_only)
+		set_disk_ro(msb->disk, true);
+
 	rc = device_add_disk(&card->dev, msb->disk, NULL);
 	if (rc)
 		goto out_cleanup_disk;
-- 
2.34.1