Be a bit more specific about EINVAL and negative offsets.

diff --git a/lib/libc/sys/lseek.2 b/lib/libc/sys/lseek.2
index 9a4f2b8..f32bc54 100644 (file)
--- a/lib/libc/sys/lseek.2
+++ b/lib/libc/sys/lseek.2
@@ -120,7 +120,9 @@ is not an open file descriptor.
 is associated with a pipe, socket, or FIFO.
 .It Bq Er EINVAL
 .Fa Whence
-is not a proper value or the resulting offset would be negative.
+is not a proper value or the resulting offset would be negative
+on a file system or special device that does not allow negative
+offsets to be used.
 .El
 .Sh SEE ALSO
 .Xr dup 2 ,