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_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
index e4f8b2d..8d9e4c7 100644
--- a/fs/xfs/xfs_qm_syscalls.c
+++ b/fs/xfs/xfs_qm_syscalls.c
@@ -296,8 +296,10 @@
 
 	if (flags & XFS_DQ_USER)
 		error = xfs_qm_scall_trunc_qfile(mp, mp->m_sb.sb_uquotino);
-	if (flags & (XFS_DQ_GROUP|XFS_DQ_PROJ))
+	if (flags & XFS_DQ_GROUP)
 		error2 = xfs_qm_scall_trunc_qfile(mp, mp->m_sb.sb_gquotino);
+	if (flags & XFS_DQ_PROJ)
+		error2 = xfs_qm_scall_trunc_qfile(mp, mp->m_sb.sb_pquotino);
 
 	return error ? error : error2;
 }
@@ -413,8 +415,10 @@
 	struct xfs_quotainfo	*q = mp->m_quotainfo;
 	struct xfs_inode	*uip = NULL;
 	struct xfs_inode	*gip = NULL;
+	struct xfs_inode	*pip = NULL;
 	bool                    tempuqip = false;
 	bool                    tempgqip = false;
+	bool                    temppqip = false;
 
 	memset(out, 0, sizeof(fs_quota_stat_t));
 
@@ -424,16 +428,14 @@
 		out->qs_gquota.qfs_ino = NULLFSINO;
 		return (0);
 	}
+
 	out->qs_flags = (__uint16_t) xfs_qm_export_flags(mp->m_qflags &
 							(XFS_ALL_QUOTA_ACCT|
 							 XFS_ALL_QUOTA_ENFD));
-	out->qs_pad = 0;
-	out->qs_uquota.qfs_ino = mp->m_sb.sb_uquotino;
-	out->qs_gquota.qfs_ino = mp->m_sb.sb_gquotino;
-
 	if (q) {
 		uip = q->qi_uquotaip;
 		gip = q->qi_gquotaip;
+		pip = q->qi_pquotaip;
 	}
 	if (!uip && mp->m_sb.sb_uquotino != NULLFSINO) {
 		if (xfs_iget(mp, NULL, mp->m_sb.sb_uquotino,
@@ -445,18 +447,41 @@
 					0, 0, &gip) == 0)
 			tempgqip = true;
 	}
+	/*
+	 * Q_XGETQSTAT doesn't have room for both group and project quotas.
+	 * So, allow the project quota values to be copied out only if
+	 * there is no group quota information available.
+	 */
+	if (!gip) {
+		if (!pip && mp->m_sb.sb_pquotino != NULLFSINO) {
+			if (xfs_iget(mp, NULL, mp->m_sb.sb_pquotino,
+						0, 0, &pip) == 0)
+				temppqip = true;
+		}
+	} else
+		pip = NULL;
 	if (uip) {
+		out->qs_uquota.qfs_ino = mp->m_sb.sb_uquotino;
 		out->qs_uquota.qfs_nblks = uip->i_d.di_nblocks;
 		out->qs_uquota.qfs_nextents = uip->i_d.di_nextents;
 		if (tempuqip)
 			IRELE(uip);
 	}
+
 	if (gip) {
+		out->qs_gquota.qfs_ino = mp->m_sb.sb_gquotino;
 		out->qs_gquota.qfs_nblks = gip->i_d.di_nblocks;
 		out->qs_gquota.qfs_nextents = gip->i_d.di_nextents;
 		if (tempgqip)
 			IRELE(gip);
 	}
+	if (pip) {
+		out->qs_gquota.qfs_ino = mp->m_sb.sb_gquotino;
+		out->qs_gquota.qfs_nblks = pip->i_d.di_nblocks;
+		out->qs_gquota.qfs_nextents = pip->i_d.di_nextents;
+		if (temppqip)
+			IRELE(pip);
+	}
 	if (q) {
 		out->qs_incoredqs = q->qi_dquots;
 		out->qs_btimelimit = q->qi_btimelimit;