pivot_root.2: Rework the text on "future changes" to reflect that 20 years have passed

Some of the text was written long ago, and hinted that things
might change in the future. However, 20 years have passed
and these details have not changed, so rework the text to
hint at that fact.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man2/pivot_root.2 b/man2/pivot_root.2
index 569faa5640221db65219ab7315ef50df5ac3b3bc..0428a5eb3ecc131defae06d055ca1883e3d95a31 100644 (file)
--- a/man2/pivot_root.2
+++ b/man2/pivot_root.2
@@ -50,8 +50,12 @@ root and current working directory to \fInew_root\fP before invoking
 .PP
 The paragraph above is intentionally vague because the implementation of
 .BR pivot_root ()
-may change in the future.
-Currently,
+may change in the future
+(or so it was thought when this system call was first added).
+However,
+the behavior on this point has remained consistent since
+.BR pivot_root ()
+was first implemented:
 .BR pivot_root ()
 changes the root directory and the current working directory
 of each process or thread in the same mount namespace to
@@ -61,7 +65,7 @@ This is necessary in order to prevent kernel threads from keeping the old
 root directory busy with their root and current working directory,
 even if they never access
 the filesystem in any way.
-In the future, there may be a mechanism for
+Perhaps one day there may be a mechanism for
 kernel threads to explicitly relinquish any access to the filesystem,
 such that this fairly intrusive mechanism can be removed from
 .BR pivot_root ().