+/*
+ * The following three functions are provided for compatibility with
+ * older ZPL version in order to determine if the file use to have
+ * an external ACL and what version of ACL previously existed on the
+ * file. Would really be nice to not need this, sigh.
+ */
+uint64_t
+zfs_external_acl(znode_t *zp)
+{
+ zfs_acl_phys_t acl_phys;
+ int error;
+
+ if (zp->z_is_sa)
+ return (0);
+
+ /*
+ * Need to deal with a potential
+ * race where zfs_sa_upgrade could cause
+ * z_isa_sa to change.
+ *
+ * If the lookup fails then the state of z_is_sa should have
+ * changed.
+ */
+
+ if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_ZNODE_ACL(ZTOZSB(zp)),
+ &acl_phys, sizeof (acl_phys))) == 0)
+ return (acl_phys.z_acl_extern_obj);
+ else {
+ /*
+ * after upgrade the SA_ZPL_ZNODE_ACL should have been
+ * removed
+ */
+ VERIFY(zp->z_is_sa && error == ENOENT);
+ return (0);
+ }
+}
+
+/*
+ * Determine size of ACL in bytes
+ *
+ * This is more complicated than it should be since we have to deal
+ * with old external ACLs.
+ */
+static int
+zfs_acl_znode_info(znode_t *zp, int *aclsize, int *aclcount,
+ zfs_acl_phys_t *aclphys)
+{
+ zfs_sb_t *zsb = ZTOZSB(zp);
+ uint64_t acl_count;
+ int size;
+ int error;
+
+ ASSERT(MUTEX_HELD(&zp->z_acl_lock));
+ if (zp->z_is_sa) {
+ if ((error = sa_size(zp->z_sa_hdl, SA_ZPL_DACL_ACES(zsb),
+ &size)) != 0)
+ return (error);
+ *aclsize = size;
+ if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_DACL_COUNT(zsb),
+ &acl_count, sizeof (acl_count))) != 0)
+ return (error);
+ *aclcount = acl_count;
+ } else {
+ if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_ZNODE_ACL(zsb),
+ aclphys, sizeof (*aclphys))) != 0)
+ return (error);
+
+ if (aclphys->z_acl_version == ZFS_ACL_VERSION_INITIAL) {
+ *aclsize = ZFS_ACL_SIZE(aclphys->z_acl_size);
+ *aclcount = aclphys->z_acl_size;
+ } else {
+ *aclsize = aclphys->z_acl_size;
+ *aclcount = aclphys->z_acl_count;
+ }
+ }
+ return (0);
+}
+
+int
+zfs_znode_acl_version(znode_t *zp)
+{
+ zfs_acl_phys_t acl_phys;
+
+ if (zp->z_is_sa)
+ return (ZFS_ACL_VERSION_FUID);
+ else {
+ int error;
+
+ /*
+ * Need to deal with a potential
+ * race where zfs_sa_upgrade could cause
+ * z_isa_sa to change.
+ *
+ * If the lookup fails then the state of z_is_sa should have
+ * changed.
+ */
+ if ((error = sa_lookup(zp->z_sa_hdl,
+ SA_ZPL_ZNODE_ACL(ZTOZSB(zp)),
+ &acl_phys, sizeof (acl_phys))) == 0)
+ return (acl_phys.z_acl_version);
+ else {
+ /*
+ * After upgrade SA_ZPL_ZNODE_ACL should have
+ * been removed.
+ */
+ VERIFY(zp->z_is_sa && error == ENOENT);
+ return (ZFS_ACL_VERSION_FUID);
+ }
+ }
+}
+