xfs: store xfs_mount in the buftarg instead of in the xfs_buf
Each buffer contains both a buftarg pointer and a mount pointer. If
we add a mount pointer into the buftarg, we can avoid needing the
b_mount field in every buffer and grab it from the buftarg when
needed instead. This shrinks the xfs_buf by 8 bytes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 1b09d7a..ee75576 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -692,8 +692,7 @@
* the first. If we do already have one, there is
* nothing to do here so return.
*/
- if (bp->b_mount != mp)
- bp->b_mount = mp;
+ ASSERT(bp->b_target->bt_mount == mp);
if (XFS_BUF_FSPRIVATE(bp, void *) != NULL) {
lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
if (lip->li_type == XFS_LI_BUF) {