linux-kernel - [PATCH] fs/block_dev.c: return the right error in thaw

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Date:   Tue,  4 Oct 2016 10:53:40 +0200
From:   Pierre Morel <pmorel@...ux.vnet.ibm.com>
To:     viro@...iv.linux.org.uk
Cc:     linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        mguzik@...hat.com, farman@...ux.vnet.ibm.com,
        cornelia.huck@...ibm.com
Subject: [PATCH] fs/block_dev.c: return the right error in thaw_bdev()

When triggering thaw-filesystems via magic sysrq, the system enters a
loop in do_thaw_one(), as thaw_bdev() still returns success if
bd_fsfreeze_count == 0. To fix this, let thaw_bdev() always return
error (and simplify the code a bit at the same time).

Reviewed-by: Eric Farman <farman@...ux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@...ibm.com>
Signed-off-by: Pierre Morel <pmorel@...ux.vnet.ibm.com>
---
 fs/block_dev.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 08ae993..0e7a8f4 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -302,14 +302,11 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)
 		error = sb->s_op->thaw_super(sb);
 	else
 		error = thaw_super(sb);
-	if (error) {
+	if (error)
 		bdev->bd_fsfreeze_count++;
-		mutex_unlock(&bdev->bd_fsfreeze_mutex);
-		return error;
-	}
 out:
 	mutex_unlock(&bdev->bd_fsfreeze_mutex);
-	return 0;
+	return error;
 }
 EXPORT_SYMBOL(thaw_bdev);
 
-- 
2.5.0