xfs: Start using pquotaino from the superblock.

Start using pquotino and define a macro to check if the
superblock has pquotino.

Keep backward compatibilty by alowing mount of older superblock
with no separate pquota inode.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 1d68ffc..525524e 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -421,12 +421,6 @@
 	}
 #endif
 
-	if ((mp->m_qflags & (XFS_GQUOTA_ACCT | XFS_GQUOTA_ACTIVE)) &&
-	    (mp->m_qflags & (XFS_PQUOTA_ACCT | XFS_PQUOTA_ACTIVE))) {
-		xfs_warn(mp, "cannot mount with both project and group quota");
-		return EINVAL;
-	}
-
 	if ((dsunit && !dswidth) || (!dsunit && dswidth)) {
 		xfs_warn(mp, "sunit and swidth must be specified together");
 		return EINVAL;
@@ -556,14 +550,13 @@
 	else if (mp->m_qflags & XFS_UQUOTA_ACCT)
 		seq_puts(m, "," MNTOPT_UQUOTANOENF);
 
-	/* Either project or group quotas can be active, not both */
-
 	if (mp->m_qflags & XFS_PQUOTA_ACCT) {
 		if (mp->m_qflags & XFS_PQUOTA_ENFD)
 			seq_puts(m, "," MNTOPT_PRJQUOTA);
 		else
 			seq_puts(m, "," MNTOPT_PQUOTANOENF);
-	} else if (mp->m_qflags & XFS_GQUOTA_ACCT) {
+	}
+	if (mp->m_qflags & XFS_GQUOTA_ACCT) {
 		if (mp->m_qflags & XFS_GQUOTA_ENFD)
 			seq_puts(m, "," MNTOPT_GRPQUOTA);
 		else
@@ -1396,6 +1389,14 @@
 		return XFS_ERROR(EROFS);
 	}
 
+	if ((mp->m_qflags & (XFS_GQUOTA_ACCT | XFS_GQUOTA_ACTIVE)) &&
+	    (mp->m_qflags & (XFS_PQUOTA_ACCT | XFS_PQUOTA_ACTIVE)) &&
+	    !xfs_sb_version_has_pquotino(&mp->m_sb)) {
+		xfs_warn(mp,
+		  "Super block does not support project and group quota together");
+		return XFS_ERROR(EINVAL);
+	}
+
 	return 0;
 }