[PATCH 1/2] xfs: use b_maps[] for discontiguous buffers

[Christoph Hellwig]

On Tue, Nov 20, 2012 at 04:41:21PM -0600, Mark Tinguely wrote:
> This patch sets all the b_bmap accesses to be b_maps[0]. b_maps[0]
> works for single and multiple segment buffers.
> 
> This fixes a bug where xfs_trans_buf_item_match() could not find a
> multi-segment buffer associated with the transaction because it was
> looking for the block number in the single segment location
> b_map.bm.bn rather than the new generic b_maps[0].bm.bn. This
> resulted in recursive buffer lock that can never be satisfied.

Should b_map be renamed to __b_map so that accesses to it are cought
more easily?

Also do hyou have a test case for the issue?