xfs: refactor loading quota inodes in the regular case

Create a helper function to load quota inodes in the case where the
dqtype and the sb quota inode fields correspond.  This is true for
nearly all the iget callsites in the quota code, except for when we're
switching the group and project quota inodes.  We'll need this in
subsequent patches to make the metadir handling less convoluted.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 40 insertions, 6 deletions

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 63f6ca2db251..7e2307921deb 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -1539,6 +1539,43 @@ xfs_qm_mount_quotas(
 }
 
 /*
+ * Load the inode for a given type of quota, assuming that the sb fields have
+ * been sorted out.  This is not true when switching quota types on a V4
+ * filesystem, so do not use this function for that.
+ *
+ * Returns -ENOENT if the quota inode field is NULLFSINO; 0 and an inode on
+ * success; or a negative errno.
+ */
+int
+xfs_qm_qino_load(
+	struct xfs_mount	*mp,
+	xfs_dqtype_t		type,
+	struct xfs_inode	**ipp)
+{
+	xfs_ino_t		ino = NULLFSINO;
+
+	switch (type) {
+	case XFS_DQTYPE_USER:
+		ino = mp->m_sb.sb_uquotino;
+		break;
+	case XFS_DQTYPE_GROUP:
+		ino = mp->m_sb.sb_gquotino;
+		break;
+	case XFS_DQTYPE_PROJ:
+		ino = mp->m_sb.sb_pquotino;
+		break;
+	default:
+		ASSERT(0);
+		return -EFSCORRUPTED;
+	}
+
+	if (ino == NULLFSINO)
+		return -ENOENT;
+
+	return xfs_iget(mp, NULL, ino, 0, 0, ipp);
+}
+
+/*
  * This is called after the superblock has been read in and we're ready to
  * iget the quota inodes.
  */
@@ -1561,24 +1598,21 @@ xfs_qm_init_quotainos(
 		if (XFS_IS_UQUOTA_ON(mp) &&
 		    mp->m_sb.sb_uquotino != NULLFSINO) {
 			ASSERT(mp->m_sb.sb_uquotino > 0);
-			error = xfs_iget(mp, NULL, mp->m_sb.sb_uquotino,
-					     0, 0, &uip);
+			error = xfs_qm_qino_load(mp, XFS_DQTYPE_USER, &uip);
 			if (error)
 				return error;
 		}
 		if (XFS_IS_GQUOTA_ON(mp) &&
 		    mp->m_sb.sb_gquotino != NULLFSINO) {
 			ASSERT(mp->m_sb.sb_gquotino > 0);
-			error = xfs_iget(mp, NULL, mp->m_sb.sb_gquotino,
-					     0, 0, &gip);
+			error = xfs_qm_qino_load(mp, XFS_DQTYPE_GROUP, &gip);
 			if (error)
 				goto error_rele;
 		}
 		if (XFS_IS_PQUOTA_ON(mp) &&
 		    mp->m_sb.sb_pquotino != NULLFSINO) {
 			ASSERT(mp->m_sb.sb_pquotino > 0);
-			error = xfs_iget(mp, NULL, mp->m_sb.sb_pquotino,
-					     0, 0, &pip);
+			error = xfs_qm_qino_load(mp, XFS_DQTYPE_PROJ, &pip);
 			if (error)
 				goto error_rele;
 		}