Backup with SELINUX=permissive may result to restore errors due to /proc & /sys extended attributes

[kritzenthaler]

This defect was observed on 2.2.9.2 (RHEL5.4). It should be the same on other distro though.

The following errors are encountered when trying to restore the backup:

===
setfattr: proc: Operation not supported
setfattr: sys: Operation not supported
===

Due to that, the GUI restore phase does not seem to finalize properly for a lambda end-user (even if it may have no other impacts).

It has been observed in the filelist-7 that /proc and /sys were backed-up with the following xattr:

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# file: proc
security.selinux=0x73797374656d5f753a6f626a6563745f723a70726f635f743a733000
===
# file: sys
security.selinux=0x73797374656d5f753a6f626a6563745f723a73797366735f743a733000
===

Even if /proc and /sys sub-files/sub-dirs are not backed-up, we should also fully remove /proc and /sys from the backup. I guess removing it from the backup would avoid that kind of issue at restore time.

Note that the WA to set -E "/proc /sys" to exclude them did not work for me.