From bd7c26bc7bb7af37c21d46faf28aa0e88606b98f Mon Sep 17 00:00:00 2001 From: John Ericson Date: Sun, 7 Apr 2024 21:37:30 -0400 Subject: [PATCH] Add comment explaining `LIBMOUNT_FORCE_MOUNT2=always` --- .../functional/local-overlay-store/common.sh | 21 +++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/tests/functional/local-overlay-store/common.sh b/tests/functional/local-overlay-store/common.sh index 1c70f947f..2634f8c8f 100644 --- a/tests/functional/local-overlay-store/common.sh +++ b/tests/functional/local-overlay-store/common.sh @@ -1,5 +1,26 @@ source ../common.sh +# The new Linux mount interface does not seem to support remounting +# OverlayFS mount points. +# +# It is not clear whether this is intentional or not: +# +# The kernel source code [1] would seem to indicate merely remounting +# while *changing* mount options is now an error because it erroneously +# succeeded (by ignoring those new options) before. However, we are +# *not* trying to remount with changed options, and are still hitting +# the failure when using the new interface. +# +# For further details, see these `util-linux` issues: +# +# - https://github.com/util-linux/util-linux/issues/2528 +# - https://github.com/util-linux/util-linux/issues/2576 +# +# In the meantime, setting this environment variable to "always" will +# force the use of the old mount interface, keeping the remounting +# working and these tests passing. +# +# [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/overlayfs/params.c?id=3006adf3be79cde4d14b1800b963b82b6e5572e0#n549 export LIBMOUNT_FORCE_MOUNT2=always requireEnvironment () {