xfs: refactor xfs_trans_reserve() interface

With the new xfs_trans_res structure has been introduced, the log
reservation size, log count as well as log flags are pre-initialized
at mount time.  So it's time to refine xfs_trans_reserve() interface
to be more neat.

Also, introduce a new helper M_RES() to return a pointer to the
mp->m_resv structure to simplify the input.

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_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
index 6fdccc3..5290af2 100644
--- a/fs/xfs/xfs_qm_syscalls.c
+++ b/fs/xfs/xfs_qm_syscalls.c
@@ -247,9 +247,7 @@
 	xfs_ilock(ip, XFS_IOLOCK_EXCL);
 
 	tp = xfs_trans_alloc(mp, XFS_TRANS_TRUNCATE_FILE);
-	error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
-				  XFS_TRANS_PERM_LOG_RES,
-				  XFS_ITRUNCATE_LOG_COUNT);
+	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
 	if (error) {
 		xfs_trans_cancel(tp, 0);
 		xfs_iunlock(ip, XFS_IOLOCK_EXCL);
@@ -540,8 +538,7 @@
 	xfs_dqunlock(dqp);
 
 	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SETQLIM);
-	error = xfs_trans_reserve(tp, 0, XFS_QM_SETQLIM_LOG_RES(mp),
-				  0, 0, XFS_DEFAULT_LOG_COUNT);
+	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_qm_setqlim, 0, 0);
 	if (error) {
 		xfs_trans_cancel(tp, 0);
 		goto out_rele;
@@ -675,8 +672,7 @@
 
 	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_QUOTAOFF_END);
 
-	error = xfs_trans_reserve(tp, 0, XFS_QM_QUOTAOFF_END_LOG_RES(mp),
-				  0, 0, XFS_DEFAULT_LOG_COUNT);
+	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_qm_equotaoff, 0, 0);
 	if (error) {
 		xfs_trans_cancel(tp, 0);
 		return (error);
@@ -709,8 +705,7 @@
 	uint			oldsbqflag=0;
 
 	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_QUOTAOFF);
-	error = xfs_trans_reserve(tp, 0, XFS_QM_QUOTAOFF_LOG_RES(mp),
-				  0, 0, XFS_DEFAULT_LOG_COUNT);
+	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_qm_quotaoff, 0, 0);
 	if (error)
 		goto error0;