xfs: kill xfs_qmops

Kill the quota ops function vector and replace it with direct calls or
stubs in the CONFIG_XFS_QUOTA=n case.

Make sure we check XFS_IS_QUOTA_RUNNING in the right spots.  We can remove
the number of those checks because the XFS_TRANS_DQ_DIRTY flag can't be set
otherwise.

This brings us back closer to the way this code worked in IRIX and earlier
Linux versions, but we keep a lot of the more useful factoring of common
code.

Eventually we should also kill xfs_qm_bhv.c, but that's left for a later
patch.

Reduces the size of the source code by about 250 lines and the size of
XFS module by about 1.5 kilobytes with quotas enabled:

   text	   data	    bss	    dec	    hex	filename
 615957	   2960	   3848	 622765	  980ad	fs/xfs/xfs.o
 617231	   3152	   3848	 624231	  98667	fs/xfs/xfs.o.old

Fallout:

 - xfs_qm_dqattach is split into xfs_qm_dqattach_locked which expects
   the inode locked and xfs_qm_dqattach which does the locking around it,
   thus removing XFS_QMOPT_ILOCKED.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 5aaa2d7..feb30a9 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -385,7 +385,7 @@
 	 * Make sure that the dquots are there. This doesn't hold
 	 * the ilock across a disk read.
 	 */
-	error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
+	error = xfs_qm_dqattach_locked(ip, 0);
 	if (error)
 		return XFS_ERROR(error);
 
@@ -444,8 +444,7 @@
 	if (error)
 		goto error_out;
 
-	error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip,
-					      qblocks, 0, quota_flag);
+	error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
 	if (error)
 		goto error1;
 
@@ -495,7 +494,7 @@
 
 error0:	/* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
 	xfs_bmap_cancel(&free_list);
-	XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
+	xfs_trans_unreserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
 
 error1:	/* Just cancel transaction */
 	xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
@@ -582,7 +581,7 @@
 	 * Make sure that the dquots are there. This doesn't hold
 	 * the ilock across a disk read.
 	 */
-	error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
+	error = xfs_qm_dqattach_locked(ip, 0);
 	if (error)
 		return XFS_ERROR(error);
 
@@ -684,7 +683,8 @@
 	/*
 	 * Make sure that the dquots are there.
 	 */
-	if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
+	error = xfs_qm_dqattach(ip, 0);
+	if (error)
 		return XFS_ERROR(error);
 
 	offset_fsb = XFS_B_TO_FSBT(mp, offset);