Re: [PATCH] fs-private data in struct block_device

[Christoph Hellwig <hch@lst.de>]

On Thu, Jan 01, 2004 at 11:28:32PM +0000, viro@parcelfarce.linux.theplanet.co.uk wrote:
> > Okay, let's make it more general.  Throw the filesystem completly out of
> > the few and say the private data can be used by the owner of that
> > blockdevice as established by bd_claim, okay?
> 
> OK...  One question: what rules do you want wrt multiple claims with the
> same owner?

I'd say this is the owners problem and add a big comment about that.
What about something like the version below?:


--- 1.276/include/linux/fs.h	Mon Dec 29 22:37:20 2003
+++ edited/include/linux/fs.h	Fri Jan  2 01:30:42 2004
@@ -353,6 +353,13 @@
 	int			bd_invalidated;
 	struct gendisk *	bd_disk;
 	struct list_head	bd_list;
+	/*
+	 * Private data.  You must have bd_claimed the block_device
+	 * to use this.  NOTE:  bd_claims allows an owner to claim
+	 * the same device multiple timers, the owner must take special
+	 * care to not mess up bd_private for that case.
+	 */
+	unsigned long		bd_private;
 };
 
 /*