I just want to add one additional potential race issue that I saw in my
log files.
I used the cryptsetup.target which I understood to be a synchronization
barrier.
In my case I used 'Before=cryptsetup.target' in my mnt-usbkey.mount, but
this issue is more general.
Looking at the log files, it appears that cryptsetup.target is triggered
not triggered when the cryptsetup stuff begins.
Rather, a separate service for each entry in /etc/crypttab completes
right before cryptsetup.target.
So I'm thinking that this is another case of a race issue. If someone
specifies 'Before=cryptsetup.target' as a synchronization target, there
is a window of time before that where stuff in the /etc/crypttab is
being performed yet cryptsetup.target has not triggered.
[ 27.073983] systemd[1]: About to execute:
/lib/systemd/systemd-cryptsetup attach encrypt_storage
/dev/disk/by-id/md-uuid-432b22e3:364555c6:f3927192:227cec7f
/mnt/usbkey/storage.key cipher=aes-cbc-essiv:sha256,size=256,hash=sha1
[ 27.086057] rmmod[1004]: ERROR: Module scsi_wait_scan does not exist
in /proc/modules
[ 27.104056] systemd[1]: Forked /lib/systemd/systemd-cryptsetup as 1007
[ 27.104133] systemd[1]: cryptsetup@encrypt_storage.service changed
dead -> start
...
[ 29.042725] systemd[1]: cryptsetup@encrypt_storage.service: main
process exited, code=exited, status=0
[ 29.075045] systemd[1]: cryptsetup@encrypt_storage.service changed
start -> exited
[ 29.075051] systemd[1]: Job cryptsetup@encrypt_storage.service/start
finished, result=done
[ 29.075215] systemd[1]: cryptsetup.target changed dead -> active
[ 29.075221] systemd[1]: Job cryptsetup.target/start finished, result=done
From the above logs, there is a full 2 seconds between systemd doing
the '/lib/systemd/systemd-cryptsetup attach' and when 'cryptsetup.target
changed dead -> active' is declared.
In my case, I specified a 'Before=cryptsetup.target' in my
mnt-usbkey.mount. However, what would prevent the mnt-usbkey.mount from
not being executed within the above 2 second interval? This looks wrong
to me.
_______________________________________________
systemd-devel mailing list
systemd-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/systemd-devel
