Hi, Quoting Peter Pentchev (2024-05-30 10:33:08) > > thank you for having discussed this change on d-devel and for adding > > documentation to NEWS and release notes to announce this change. I also > > think it is sensible to roll this only out on new installations and to keep > > the behaviour on existing setups. Thank you for implementing that as well. > > > > That being said, maybe some Perl wizard knows how to do a flock on a > > directory > > in Perl? > > I wouldn't call myself a Perl wizard by a long stretch, but I can give it a > try :) > > > I tried this: > > > > use Fcntl qw(LOCK_EX); > > opendir(my $handle, ".") or die "opendir: $!"; > [snip] > > Here lies your problem. The flock(2) syscall works on file descriptors, > the things returned by open(2), not on the dirent structures returned by > opendir(3). So you need something like this: > > use v5.10; # I really should switch to at least 5.16 if not 5.24 > use strict; > use warnings; > > use Fcntl qw(O_RDONLY O_DIRECTORY LOCK_EX); > > my $dirname = "/tmp/to-be-locked"; > sysopen(my $handle, "/tmp/to-be-locked", O_RDONLY | O_DIRECTORY) or > die "Could not open $dirname: $!\n"; > flock($handle, LOCK_EX) or > die "Could not lock $dirname: $!\n"; > > say "locked, it seems"; > sleep(3600);' > > I only put the sleep() part so I could check using lsof that > the directory was indeed locked. And yeah, the v5.10 part is a leftover > from the days (...until a month or two ago...) when I still had to > support stock CentOS 7 systems; I really should train my fingers to > put 5.24 there. > > Hope that helps!
it absolutely does! Thank you! I was misled by `perldoc -f flock` which states that it works on filehandles. I'll add your name to the git commit message unless you object. :) I also found another issue with this change in systemd. After the upload to unstable, 76 out of 264 mmdebstrap tests on jenkins.debian.net started to fail: https://jenkins.debian.net/job/mmdebstrap-jenkins-worker/692/consoleText The problem is, that debootstrap wants to mknod which will not work on a tmpfs mounted with nodev: + debootstrap --no-merged-usr --variant=buildd oldstable /tmp/tmp.nWmx8YeAh3 http://127.0.0.1/debian /usr/sbin/debootstrap: 1840: cannot create /tmp/tmp.nWmx8YeAh3/test-dev-null: Permission denied E: Cannot install into target '/tmp/tmp.nWmx8YeAh3' mounted with noexec or nodev Maybe this affects more CI scripts and test setups which attempt to create a temporary chroot with debootstrap in /tmp. The fix which is documented in systemd NEWS makes everything work again: --customize-hook='touch "$1/etc/systemd/system/tmp.mount"' Thanks! cheers, josch
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