diff --git a/config/kernel-generic_fillattr.m4 b/config/kernel-generic_fillattr.m4
index 02dee4d4c0..f5323f0dcb 100644
--- a/config/kernel-generic_fillattr.m4
+++ b/config/kernel-generic_fillattr.m4
@@ -7,6 +7,10 @@ dnl #
 dnl # 6.3 API
 dnl # generic_fillattr() now takes struct mnt_idmap* as the first argument
 dnl #
+dnl # 6.6 API
+dnl # generic_fillattr() now takes u32 as second argument, representing a
+dnl # request_mask for statx
+dnl #
 AC_DEFUN([ZFS_AC_KERNEL_SRC_GENERIC_FILLATTR], [
 	ZFS_LINUX_TEST_SRC([generic_fillattr_userns], [
 		#include <linux/fs.h>
@@ -25,22 +29,39 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_GENERIC_FILLATTR], [
 		struct kstat *k = NULL;
 		generic_fillattr(idmap, in, k);
 	])
+
+	ZFS_LINUX_TEST_SRC([generic_fillattr_mnt_idmap_reqmask], [
+		#include <linux/fs.h>
+	],[
+		struct mnt_idmap *idmap = NULL;
+		struct inode *in = NULL;
+		struct kstat *k = NULL;
+		generic_fillattr(idmap, 0, in, k);
+	])
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_GENERIC_FILLATTR], [
-	AC_MSG_CHECKING([whether generic_fillattr requires struct mnt_idmap*])
-	ZFS_LINUX_TEST_RESULT([generic_fillattr_mnt_idmap], [
+	AC_MSG_CHECKING(
+	    [whether generic_fillattr requires struct mnt_idmap* and request_mask])
+	ZFS_LINUX_TEST_RESULT([generic_fillattr_mnt_idmap_reqmask], [
 		AC_MSG_RESULT([yes])
-		AC_DEFINE(HAVE_GENERIC_FILLATTR_IDMAP, 1,
-		    [generic_fillattr requires struct mnt_idmap*])
+		AC_DEFINE(HAVE_GENERIC_FILLATTR_IDMAP_REQMASK, 1,
+		    [generic_fillattr requires struct mnt_idmap* and u32 request_mask])
 	],[
-		AC_MSG_CHECKING([whether generic_fillattr requires struct user_namespace*])
-		ZFS_LINUX_TEST_RESULT([generic_fillattr_userns], [
+		AC_MSG_CHECKING([whether generic_fillattr requires struct mnt_idmap*])
+		ZFS_LINUX_TEST_RESULT([generic_fillattr_mnt_idmap], [
 			AC_MSG_RESULT([yes])
-			AC_DEFINE(HAVE_GENERIC_FILLATTR_USERNS, 1,
-			    [generic_fillattr requires struct user_namespace*])
+			AC_DEFINE(HAVE_GENERIC_FILLATTR_IDMAP, 1,
+				[generic_fillattr requires struct mnt_idmap*])
 		],[
-			AC_MSG_RESULT([no])
+			AC_MSG_CHECKING([whether generic_fillattr requires struct user_namespace*])
+			ZFS_LINUX_TEST_RESULT([generic_fillattr_userns], [
+				AC_MSG_RESULT([yes])
+				AC_DEFINE(HAVE_GENERIC_FILLATTR_USERNS, 1,
+					[generic_fillattr requires struct user_namespace*])
+			],[
+				AC_MSG_RESULT([no])
+			])
 		])
 	])
 ])
diff --git a/include/os/linux/kernel/linux/vfs_compat.h b/include/os/linux/kernel/linux/vfs_compat.h
index e82bbf755d..045135fe92 100644
--- a/include/os/linux/kernel/linux/vfs_compat.h
+++ b/include/os/linux/kernel/linux/vfs_compat.h
@@ -464,10 +464,16 @@ zpl_is_32bit_api(void)
  * 6.3 API change
  * generic_fillattr() first arg is changed to struct mnt_idmap *
  *
+ * 6.6 API change
+ * generic_fillattr() gets new second arg request_mask, a u32 type
+ *
  */
 #ifdef HAVE_GENERIC_FILLATTR_IDMAP
 #define	zpl_generic_fillattr(idmap, ip, sp)	\
     generic_fillattr(idmap, ip, sp)
+#elif defined(HAVE_GENERIC_FILLATTR_IDMAP_REQMASK)
+#define	zpl_generic_fillattr(idmap, rqm, ip, sp)	\
+    generic_fillattr(idmap, rqm, ip, sp)
 #elif defined(HAVE_GENERIC_FILLATTR_USERNS)
 #define	zpl_generic_fillattr(user_ns, ip, sp)	\
     generic_fillattr(user_ns, ip, sp)
diff --git a/include/os/linux/zfs/sys/zfs_vnops_os.h b/include/os/linux/zfs/sys/zfs_vnops_os.h
index 331f2e2bcc..a29f35d258 100644
--- a/include/os/linux/zfs/sys/zfs_vnops_os.h
+++ b/include/os/linux/zfs/sys/zfs_vnops_os.h
@@ -54,7 +54,12 @@ extern int zfs_mkdir(znode_t *dzp, char *dirname, vattr_t *vap,
 extern int zfs_rmdir(znode_t *dzp, char *name, znode_t *cwd,
     cred_t *cr, int flags);
 extern int zfs_readdir(struct inode *ip, zpl_dir_context_t *ctx, cred_t *cr);
+#ifdef HAVE_GENERIC_FILLATTR_IDMAP_REQMASK
+extern int zfs_getattr_fast(zidmap_t *, u32 request_mask, struct inode *ip,
+    struct kstat *sp);
+#else
 extern int zfs_getattr_fast(zidmap_t *, struct inode *ip, struct kstat *sp);
+#endif
 extern int zfs_setattr(znode_t *zp, vattr_t *vap, int flag, cred_t *cr);
 extern int zfs_rename(znode_t *sdzp, char *snm, znode_t *tdzp,
     char *tnm, cred_t *cr, int flags);
diff --git a/module/os/linux/zfs/zfs_vnops_os.c b/module/os/linux/zfs/zfs_vnops_os.c
index 0bc7fd34c1..991d1aa1c2 100644
--- a/module/os/linux/zfs/zfs_vnops_os.c
+++ b/module/os/linux/zfs/zfs_vnops_os.c
@@ -1675,7 +1675,12 @@ out:
  */
 /* ARGSUSED */
 int
+#ifdef HAVE_GENERIC_FILLATTR_IDMAP_REQMASK
+zfs_getattr_fast(zidmap_t *user_ns, u32 request_mask, struct inode *ip,
+    struct kstat *sp)
+#else
 zfs_getattr_fast(zidmap_t *user_ns, struct inode *ip, struct kstat *sp)
+#endif
 {
 	znode_t *zp = ITOZ(ip);
 	zfsvfs_t *zfsvfs = ITOZSB(ip);
@@ -1687,7 +1692,11 @@ zfs_getattr_fast(zidmap_t *user_ns, struct inode *ip, struct kstat *sp)
 
 	mutex_enter(&zp->z_lock);
 
+#ifdef HAVE_GENERIC_FILLATTR_IDMAP_REQMASK
+	zpl_generic_fillattr(user_ns, request_mask, ip, sp);
+#else
 	zpl_generic_fillattr(user_ns, ip, sp);
+#endif
 	/*
 	 * +1 link count for root inode with visible '.zfs' directory.
 	 */
diff --git a/module/os/linux/zfs/zpl_ctldir.c b/module/os/linux/zfs/zpl_ctldir.c
index 302f0bb0ed..cb8824cc89 100644
--- a/module/os/linux/zfs/zpl_ctldir.c
+++ b/module/os/linux/zfs/zpl_ctldir.c
@@ -121,6 +121,8 @@ zpl_root_getattr_impl(const struct path *path, struct kstat *stat,
 	generic_fillattr(user_ns, ip, stat);
 #elif defined(HAVE_GENERIC_FILLATTR_IDMAP)
 	generic_fillattr(user_ns, ip, stat);
+#elif defined(HAVE_GENERIC_FILLATTR_IDMAP_REQMASK)
+	generic_fillattr(user_ns, request_mask, ip, stat);
 #else
 	(void) user_ns;
 #endif
@@ -425,6 +427,8 @@ zpl_snapdir_getattr_impl(const struct path *path, struct kstat *stat,
 	generic_fillattr(user_ns, ip, stat);
 #elif defined(HAVE_GENERIC_FILLATTR_IDMAP)
 	generic_fillattr(user_ns, ip, stat);
+#elif defined(HAVE_GENERIC_FILLATTR_IDMAP_REQMASK)
+	generic_fillattr(user_ns, request_mask, ip, stat);
 #else
 	(void) user_ns;
 #endif
@@ -583,6 +587,8 @@ zpl_shares_getattr_impl(const struct path *path, struct kstat *stat,
 		generic_fillattr(user_ns, path->dentry->d_inode, stat);
 #elif defined(HAVE_GENERIC_FILLATTR_IDMAP)
 		generic_fillattr(user_ns, path->dentry->d_inode, stat);
+#elif defined(HAVE_GENERIC_FILLATTR_IDMAP_REQMASK)
+	generic_fillattr(user_ns, request_mask, ip, stat);
 #else
 		(void) user_ns;
 #endif
@@ -597,7 +603,10 @@ zpl_shares_getattr_impl(const struct path *path, struct kstat *stat,
 
 	error = -zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp);
 	if (error == 0) {
-#if (defined(HAVE_USERNS_IOPS_GETATTR) || defined(HAVE_IDMAP_IOPS_GETATTR))
+#ifdef HAVE_GENERIC_FILLATTR_IDMAP_REQMASK
+		error = -zfs_getattr_fast(user_ns, request_mask, ZTOI(dzp),
+		    stat);
+#elif (defined(HAVE_USERNS_IOPS_GETATTR) || defined(HAVE_IDMAP_IOPS_GETATTR))
 		error = -zfs_getattr_fast(user_ns, ZTOI(dzp), stat);
 #else
 		error = -zfs_getattr_fast(kcred->user_ns, ZTOI(dzp), stat);
diff --git a/module/os/linux/zfs/zpl_inode.c b/module/os/linux/zfs/zpl_inode.c
index b4ebe0632d..ce1524440a 100644
--- a/module/os/linux/zfs/zpl_inode.c
+++ b/module/os/linux/zfs/zpl_inode.c
@@ -418,7 +418,9 @@ zpl_getattr_impl(const struct path *path, struct kstat *stat, u32 request_mask,
 	 * XXX query_flags currently ignored.
 	 */
 
-#if (defined(HAVE_USERNS_IOPS_GETATTR) || defined(HAVE_IDMAP_IOPS_GETATTR))
+#ifdef HAVE_GENERIC_FILLATTR_IDMAP_REQMASK
+	error = -zfs_getattr_fast(user_ns, request_mask, ip, stat);
+#elif (defined(HAVE_USERNS_IOPS_GETATTR) || defined(HAVE_IDMAP_IOPS_GETATTR))
 	error = -zfs_getattr_fast(user_ns, ip, stat);
 #else
 	error = -zfs_getattr_fast(kcred->user_ns, ip, stat);