Index: lib/libc/sys/mount.2
===================================================================
--- lib/libc/sys/mount.2
+++ lib/libc/sys/mount.2
@@ -274,6 +274,10 @@
 .Fa dir
 argument
 points outside the process's allocated address space.
+.It Bq Er EINTEGRITY
+The backing store for
+.Fa special
+detected corrupted data while reading.
 .El
 .Pp
 The following errors can occur for a
Index: lib/libc/sys/read.2
===================================================================
--- lib/libc/sys/read.2
+++ lib/libc/sys/read.2
@@ -217,6 +217,10 @@
 .Fa nbytes
 is greater than
 .Dv INT_MAX .
+.It Bq Er EINTEGRITY
+The backing store for
+.Fa fd
+detected corrupted data while reading.
 .El
 .Pp
 In addition,
Index: lib/libc/sys/write.2
===================================================================
--- lib/libc/sys/write.2
+++ lib/libc/sys/write.2
@@ -205,6 +205,12 @@
 if the sysctl
 .Va debug.iosize_max_clamp
 is non-zero).
+.It Bq Er EINTEGRITY
+The backing store for
+.Fa fd
+detected corrupted data while reading.
+(For example, writing a partial filesystem block may require first reading
+the existing block which may trigger this error.)
 .El
 .Pp
 In addition,