dax: advance the iomap_iter on pte and pmd faults

Advance the iomap_iter on PTE and PMD faults. Each of these
operations assign a hardcoded size to iter.processed. Replace those
with an advance and status return.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://lore.kernel.org/r/20250224144757.237706-10-bfoster@redhat.com
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: Brian Foster

fs/dax.c

@@ -1771,8 +1771,10 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
 			ret |= VM_FAULT_MAJOR;
 		}
 
-		if (!(ret & VM_FAULT_ERROR))
-			iter.processed = PAGE_SIZE;
+		if (!(ret & VM_FAULT_ERROR)) {
+			u64 length = PAGE_SIZE;
+			iter.processed = iomap_iter_advance(&iter, &length);
+		}
 	}
 
 	if (iomap_errp)
@@ -1885,8 +1887,10 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
 			continue; /* actually breaks out of the loop */
 
 		ret = dax_fault_iter(vmf, &iter, pfnp, &xas, &entry, true);
-		if (ret != VM_FAULT_FALLBACK)
-			iter.processed = PMD_SIZE;
+		if (ret != VM_FAULT_FALLBACK) {
+			u64 length = PMD_SIZE;
+			iter.processed = iomap_iter_advance(&iter, &length);
+		}
 	}
 
 unlock_entry: