#!/usr/bin/env python3
# 9998-strip-xattrs.hook.chroot
#
# mksquashfs 4.5.1 (Debian bookworm) writes a non-INVALID xattr_id_table_start
# even with -no-xattrs when the source tree contains POSIX ACL xattrs set by
# dpkg/install-time.  Linux 6.1 squashfs driver then fails with
# "unable to read xattr id index table" and aborts the mount.
#
# Strip all xattrs from the live chroot before mksquashfs sees the tree so the
# resulting squashfs has SQUASHFS_INVALID_BLK in xattr_id_table_start.

import os

def strip(path):
    try:
        for attr in os.listxattr(path, follow_symlinks=False):
            try:
                os.removexattr(path, attr, follow_symlinks=False)
            except OSError:
                pass
    except OSError:
        pass

removed = 0
for root, dirs, files in os.walk('/', topdown=True, followlinks=False):
    for name in dirs + files:
        p = os.path.join(root, name)
        try:
            attrs = os.listxattr(p, follow_symlinks=False)
            if attrs:
                strip(p)
                removed += len(attrs)
        except OSError:
            pass
    strip(root)

print(f"9998-strip-xattrs: removed xattrs from {removed} entries")