From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 25C9C910FB for ; Tue, 13 Feb 2024 16:14:16 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 9D16F38340 for ; Tue, 13 Feb 2024 16:14:15 +0100 (CET) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS for ; Tue, 13 Feb 2024 16:14:14 +0100 (CET) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 3EADB47D0F for ; Tue, 13 Feb 2024 16:14:14 +0100 (CET) From: Christoph Heiss To: pve-devel@lists.proxmox.com Date: Tue, 13 Feb 2024 16:13:59 +0100 Message-ID: <20240213151405.1282639-3-c.heiss@proxmox.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240213151405.1282639-1-c.heiss@proxmox.com> References: <20240213151405.1282639-1-c.heiss@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.003 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record T_SCC_BODY_TEXT_LINE -0.01 - Subject: [pve-devel] [PATCH installer v2 2/6] sys: command: factor out kill() + waitpid() from run_command() X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Feb 2024 15:14:16 -0000 This moves the kill() + waitpid() combo into a separate subroutine, avoiding open-coding that sequence. wait_for_process() also handles properly unkillable process (e.g. in D-state) and avoids completely locking up the installer in such cases. See [0]. For the latter case, a timeout exists (with a default of 5 seconds) in which to wait for the process to exit after sending an optional TERM/KILL signal. Also while at it, add a few basic tests for run_command(). [0] https://lists.proxmox.com/pipermail/pve-devel/2024-February/061697.html Signed-off-by: Christoph Heiss --- Changes since v1: * new patch Proxmox/Sys/Command.pm | 60 +++++++++++++++++++++++++++++++++++++----- test/Makefile | 5 +++- test/run-command.pl | 35 ++++++++++++++++++++++++ 3 files changed, 92 insertions(+), 8 deletions(-) create mode 100755 test/run-command.pl diff --git a/Proxmox/Sys/Command.pm b/Proxmox/Sys/Command.pm index c3e24b3..e64e0ee 100644 --- a/Proxmox/Sys/Command.pm +++ b/Proxmox/Sys/Command.pm @@ -33,12 +33,55 @@ my sub cmd2string { return join (' ', $quoted_args->@*); } +# Safely for the (sub-)process specified by $pid to exit, using a timeout. +# +# When kill => 1 is set, at first a TERM-signal is sent to the process before +# checking if it exited. +# If that fails, KILL is sent to process and then up to timeout => $timeout +# seconds (default: 5) are waited for the process to exit. +# +# On sucess, the exitcode of the process is returned, otherwise `undef` (aka. +# the process was unkillable). +my sub wait_for_process { + my ($pid, %params) = @_; + + kill('TERM', $pid) if $params{kill}; + + my $terminated = waitpid($pid, WNOHANG); + return $? if $terminated > 0; + + kill('KILL', $pid) if $params{kill}; + + my $timeout = $params{timeout} // 5; + for (1 .. $timeout) { + $terminated = waitpid($pid, WNOHANG); + return $? if $terminated > 0; + sleep(1); + } + + log_warn("failed to kill child pid $pid, probably stuck in D-state?\n"); + + # We tried our best, better let the child hang in the back then completely + # blocking installer progress .. it's a rather short-lived environment anyway +} + sub syscmd { my ($cmd) = @_; return run_command($cmd, undef, undef, 1); } +# Runs a command an a subprocess, properly handling IO via piping, cleaning up and passing back the +# exit code. +# +# If $cmd contains a pipe |, the command will be executed inside a bash shell. +# If $cmd contains 'chpasswd', the input will be specially quoted for that purpose. +# +# Arguments: +# * $cmd - The command to run, either a single string or array with individual arguments +# * $func - Logging subroutine to call, receives both stdout and stderr +# * $input - Stdin contents for the spawned subprocess +# * $noout - Whether to append any process output to the return value sub run_command { my ($cmd, $func, $input, $noout) = @_; @@ -104,8 +147,7 @@ sub run_command { my $count = sysread ($h, $buf, 4096); if (!defined ($count)) { my $err = $!; - kill (9, $pid); - waitpid ($pid, 0); + wait_for_process($pid, kill => 1); die "command '$cmd' failed: $err"; } $select->remove($h) if !$count; @@ -128,15 +170,19 @@ sub run_command { &$func($logout) if $func; - my $rv = waitpid ($pid, 0); + my $ec = wait_for_process($pid); - return $? if $noout; # behave like standard system(); + # behave like standard system(); returns -1 in case of errors too + return ($ec // -1) if $noout; - if ($? == -1) { + if (!defined($ec)) { + # Don't fail completely here to let the install continue + warn "command '$cmdstr' failed to exit properly\n"; + } elsif ($ec == -1) { croak "command '$cmdstr' failed to execute\n"; - } elsif (my $sig = ($? & 127)) { + } elsif (my $sig = ($ec & 127)) { croak "command '$cmdstr' failed - got signal $sig\n"; - } elsif (my $exitcode = ($? >> 8)) { + } elsif (my $exitcode = ($ec >> 8)) { croak "command '$cmdstr' failed with exit code $exitcode"; } diff --git a/test/Makefile b/test/Makefile index fb80fc4..ae80a94 100644 --- a/test/Makefile +++ b/test/Makefile @@ -3,8 +3,11 @@ all: export PERLLIB=.. .PHONY: check -check: test-zfs-arc-max +check: test-zfs-arc-max test-run-command .PHONY: test-zfs-arc-max test-zfs-arc-max: ./zfs-arc-max.pl + +test-run-command: + ./run-command.pl diff --git a/test/run-command.pl b/test/run-command.pl new file mode 100755 index 0000000..7d5805e --- /dev/null +++ b/test/run-command.pl @@ -0,0 +1,35 @@ +#!/usr/bin/perl + +use strict; +use warnings; + +use File::Temp; +use Test::More; + +use Proxmox::Sys::Command qw(run_command CMD_FINISHED); +use Proxmox::Sys::File qw(file_read_all); +use Proxmox::UI; + +my $log_file = File::Temp->new(); +Proxmox::Log::init($log_file->filename); + +Proxmox::UI::init_stdio(); + +is(run_command('echo test'), "test\n", 'basic usage'); + +is(run_command('echo test', undef, undef, 1), 0, 'system()-mode'); + +my $ret = run_command('bash -c "echo test; sleep 1000; echo test"', sub { + my $line = shift; + is($line, 'test', 'using CMD_FINISHED - produced correct log line'); + + return CMD_FINISHED; +}); +is($ret, '', 'using CMD_FINISHED'); + +# Check the log for errors/warnings +my $log = file_read_all($log_file->filename); +ok($log !~ m/(WARN|ERROR): /, 'no warnings or errors logged'); +print $log if $log =~ m/(WARN|ERROR): /; + +done_testing(); -- 2.43.0