From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Fri, 8 Dec 2006 10:36:14 +0000 (-0800)
Subject: [PATCH] new bd_mutex lockdep annotation
X-Git-Tag: v2.6.20-rc1~34^2~388
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=35a6027f1ab6594068cb8bca7705e4567753946b;p=linux-2.6

[PATCH] new bd_mutex lockdep annotation

Use the gendisk partition number to set a lock class.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 36c38f48a4..528cf053ce 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -355,10 +355,14 @@ static int bdev_set(struct inode *inode, void *data)
 
 static LIST_HEAD(all_bdevs);
 
+static struct lock_class_key bdev_part_lock_key;
+
 struct block_device *bdget(dev_t dev)
 {
 	struct block_device *bdev;
 	struct inode *inode;
+	struct gendisk *disk;
+	int part = 0;
 
 	inode = iget5_locked(bd_mnt->mnt_sb, hash(dev),
 			bdev_test, bdev_set, &dev);
@@ -384,6 +388,11 @@ struct block_device *bdget(dev_t dev)
 		list_add(&bdev->bd_list, &all_bdevs);
 		spin_unlock(&bdev_lock);
 		unlock_new_inode(inode);
+		mutex_init(&bdev->bd_mutex);
+		disk = get_gendisk(dev, &part);
+		if (part)
+			lockdep_set_class(&bdev->bd_mutex, &bdev_part_lock_key);
+		put_disk(disk);
 	}
 	return bdev;
 }