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From: David Michael <fedora.dm0@gmail.com>
Date: Fri, 29 Nov 2019 15:22:15 -0500
Message-ID: <CAEvUa7nxnby+rxK-KRMA46=exeOMApkDMAV08AjMkkPnTPV4CQ@mail.gmail.com>
Subject: Compatibility with overlayfs
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Hi,

I tried to test EROFS on Linux 5.4 as the root file system and mounted
a writable overlay (with upper layer on tmpfs) over /etc, but I get
ENODATA errors when attempting to modify files.  For example, adding a
user results in "Failed to take /etc/passwd lock: No data available".
Files can be modified after unlinking and restoring them so they're
created on the upper layer.  This is not necessary with other
read-only file systems (at least squashfs or ext4 with the read-only
feature).  I tried while forcing compact and extended inodes.

Is EROFS intended to be usable as a lower layer with overlayfs?

Thanks.

David