1 files changed, 37 insertions, 2 deletions

diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index 175f544f7c45..bd8379b98374 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -506,6 +506,42 @@ xfs_dquot_alloc(
 	return dqp;
 }
 
+/* Check the ondisk dquot's id and type match what the incore dquot expects. */
+static bool
+xfs_dquot_check_type(
+	struct xfs_dquot	*dqp,
+	struct xfs_disk_dquot	*ddqp)
+{
+	uint8_t			ddqp_type;
+	uint8_t			dqp_type;
+
+	ddqp_type = ddqp->d_type & XFS_DQTYPE_REC_MASK;
+	dqp_type = xfs_dquot_type(dqp);
+
+	if (be32_to_cpu(ddqp->d_id) != dqp->q_id)
+		return false;
+
+	/*
+	 * V5 filesystems always expect an exact type match.  V4 filesystems
+	 * expect an exact match for user dquots and for non-root group and
+	 * project dquots.
+	 */
+	if (xfs_sb_version_hascrc(&dqp->q_mount->m_sb) ||
+	    dqp_type == XFS_DQTYPE_USER || dqp->q_id != 0)
+		return ddqp_type == dqp_type;
+
+	/*
+	 * V4 filesystems support either group or project quotas, but not both
+	 * at the same time.  The non-user quota file can be switched between
+	 * group and project quota uses depending on the mount options, which
+	 * means that we can encounter the other type when we try to load quota
+	 * defaults.  Quotacheck will soon reset the the entire quota file
+	 * (including the root dquot) anyway, but don't log scary corruption
+	 * reports to dmesg.
+	 */
+	return ddqp_type == XFS_DQTYPE_GROUP || ddqp_type == XFS_DQTYPE_PROJ;
+}
+
 /* Copy the in-core quota fields in from the on-disk buffer. */
 STATIC int
 xfs_dquot_from_disk(
@@ -518,8 +554,7 @@ xfs_dquot_from_disk(
 	 * Ensure that we got the type and ID we were looking for.
 	 * Everything else was checked by the dquot buffer verifier.
 	 */
-	if ((ddqp->d_type & XFS_DQTYPE_REC_MASK) != xfs_dquot_type(dqp) ||
-	    be32_to_cpu(ddqp->d_id) != dqp->q_id) {
+	if (!xfs_dquot_check_type(dqp, ddqp)) {
 		xfs_alert_tag(bp->b_mount, XFS_PTAG_VERIFIER_ERROR,
 			  "Metadata corruption detected at %pS, quota %u",
 			  __this_address, dqp->q_id);