When the 'loop' kernel module isn't loaded in a running system, it gets
excluded from the hostonly initrd. Given that the crypt-loop dracut
module has to be loaded explicitly anyway, it makes sense to always
include the requisite loop kernel module.
When booting with 'rd.info', the 'info' statements in the crypt-loop
module's 'loop_decrypt' function are output to stdout along with the key
that gets piped into the 'cryptsetup' command, which causes the crypt
device unlocking to fail.
There are two possible simple solutions to this problem:
1. Redirect the info messages to stderr (just add '>&2' at the end of
the info statements).
or
2. Remove the info statements altogether.
I have tested both and they both work, but this commit implements #2.
The existing info messages are long (they overflow 80 characters
easily) and redundant (the password prompt clearly indicates what is
happening), and just generally not useful. Given that no one has
reported or fixed this bug in the three years that this module has
existed, no one will miss these info messages.
The commit also changes an error message in the same function to be more
descriptive.
Add new functions require_binaries() and require_any_binary() to be used
in the check() section of module-setup.sh.
These functions print a warning line telling the user, which binary is
missing for the specific dracut module.
This unifies the way of checking for binaries and makes the life of an
initramfs creator easier, if he wants to find out why a specific dracut
module is not included in the initramfs.
James Lee