[PATCH 4/6] ext4: Block writes to journal device

From: Jan Kara <jack@suse.cz>
To: <linux-fsdevel@vger.kernel.org>
Cc: <linux-block@vger.kernel.org>,
	Christoph Hellwig <hch@infradead.org>,
	Christian Brauner <brauner@kernel.org>,
	Jens Axboe <axboe@kernel.dk>, Kees Cook <keescook@google.com>,
	Ted Tso <tytso@mit.edu>, syzkaller <syzkaller@googlegroups.com>,
	Alexander Popov <alex.popov@linux.com>,
	Eric Biggers <ebiggers@google.com>, <linux-xfs@vger.kernel.org>,
	linux-btrfs@vger.kernel.org, Dmitry Vyukov <dvyukov@google.com>,
	Jan Kara <jack@suse.cz>
Subject: [PATCH 4/6] ext4: Block writes to journal device
Date: Tue,  4 Jul 2023 14:56:52 +0200	[thread overview]
Message-ID: <20230704125702.23180-4-jack@suse.cz> (raw)
In-Reply-To: <20230704122727.17096-1-jack@suse.cz>

Ask block layer to not allow other writers to open block device used
for ext4 journal.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/super.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index cbeb8a555fe3..8181285b7549 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1112,8 +1112,9 @@ static struct bdev_handle *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 {
 	struct bdev_handle *handle;
 
-	handle = blkdev_get_by_dev(dev, BLK_OPEN_READ | BLK_OPEN_WRITE, sb,
-				   &ext4_holder_ops);
+	handle = blkdev_get_by_dev(dev,
+			BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_BLOCK_WRITES,
+			sb, &ext4_holder_ops);
 	if (IS_ERR(handle))
 		goto fail;
 	return handle;
-- 
2.35.3

