xfs: Introduce a new structure to hold transaction reservation items

Introduce a new structure xfs_trans_res to hold transaction
reservation item info per log ticket.

We also need to improve xfs_trans_resv_calc() by initializing the
log count as well as log flags for permanent log reservation.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 829035f6..1fa0584 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -136,7 +136,7 @@
 	int			m_ialloc_blks;	/* blocks in inode allocation */
 	int			m_inoalign_mask;/* mask sb_inoalignmt if used */
 	uint			m_qflags;	/* quota status flags */
-	struct xfs_trans_resv	m_reservations;	/* precomputed res values */
+	struct xfs_trans_resv	m_resv;		/* precomputed res values */
 	__uint64_t		m_maxicount;	/* maximum inode count */
 	__uint64_t		m_resblks;	/* total reserved blocks */
 	__uint64_t		m_resblks_avail;/* available reserved blocks */