From 91356e1cee5329a898d79d45ee01a9c2fc208a3d Mon Sep 17 00:00:00 2001 From: "Alex Xu (Hello71)" Date: Tue, 27 Apr 2021 18:31:04 -0400 Subject: update README --- README.rst | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/README.rst b/README.rst index 057d5df..87f8ffc 100644 --- a/README.rst +++ b/README.rst @@ -17,8 +17,8 @@ Benefits over manually calling ``mkdir /tmp/x; mount ...`` - synchronizes owner, permissions, and xattrs (including lowerdir ACL) - autodetects optimization flags (redirect_dir, metacopy, index, volatile) -Overmounting notes ------------------- +Overmounting +------------ Like any other Linux mount, an overlayfs mount only affects new directory lookups. If a process has its current directory or has files open inside the @@ -31,6 +31,21 @@ tmpoverlay to overmount ``/``. .. _pivot_root(2): https://man7.org/linux/man-pages/man2/pivot_root.2.html .. _pivot_root(8): https://man7.org/linux/man-pages/man8/pivot_root.8.html +Changes to underlying filesystems +--------------------------------- + +Per `the kernel overlayfs documentation`_, changing underlying filesystems +while the overlay is mounted is not supported. + +.. _the kernel overlayfs documentation: https://www.kernel.org/doc/html/latest/filesystems/overlayfs.html#changes-to-underlying-filesystems + +Pseudo-filesystems +------------------ + +Pseudo-filesystems like procfs and sysfs are not intended to be used with +overlayfs. Therefore, running commands like ``tmpoverlay /proc`` may have +unexpected results. + POSIX compliance ---------------- -- cgit v1.2.3-54-g00ecf