doc: fix details on the interaction of df with device nodes

* man/df.x: Don't say that a dev node is always on the root file system.
* doc/coreutils.texi (df invocation): Likewise.  Also state that the
device node to mounted file system interpretation is only done when
passed absolute paths to device nodes.

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index ae1081b1acefdb5d2cf3ea3d212480e8d1ac0425..b3233f602cc16f83db8c67a0dd2feb886f09ab50 100644 (file)
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -11023,14 +11023,12 @@ not shown per default when already the real root device has been mounted.
 
 @cindex disk device file
 @cindex device file, disk
-If an argument @var{file} is a disk device file containing a mounted
-file system, @command{df} shows the space available on that file system
-rather than on the file system containing the device node (i.e., the root
-file system).  GNU @command{df} does not attempt to determine the
-disk usage
+If an argument @var{file} is an absolute name of a disk device node containing
+a mounted file system, @command{df} shows the space available on that
+file system rather than on the file system containing the device node.
+GNU @command{df} does not attempt to determine the disk usage
 on unmounted file systems, because on most kinds of systems doing so
-requires extremely nonportable intimate knowledge of file system
-structures.
+requires extremely nonportable intimate knowledge of file system structures.
 
 The program accepts the following options.  Also see @ref{Common options}.
 

diff --git a/man/df.x b/man/df.x
index 7e908ae09a8a294504e551cc1024950a2b66d808..c8889b42b11c246479edd03994d4f25de757e0fc 100644 (file)
--- a/man/df.x
+++ b/man/df.x
@@ -21,8 +21,7 @@ If an argument is the absolute file name of a disk device node containing a
 mounted file system,
 .B df
 shows the space available on that file system rather than on the
-file system containing the device node (which is always the root
-file system).  This version of
+file system containing the device node.  This version of
 .B df
 cannot show the space available on unmounted file systems, because on
 most kinds of systems doing so requires very nonportable intimate