Tools::df: fork and use Filesys::Df

Instead of depending on the 'df' commandline tool do a
fork() to create a killable process and run Filesys::Df,
returning the data over a pipe.

diff --git a/debian/control b/debian/control
index 2d85e01c4c56fd64d6d70af51b7f417479a36dd5..c00ca5e43b74967d638a3c1749c00fdc24da205a 100644 (file)
--- a/debian/control
+++ b/debian/control
@@ -7,6 +7,6 @@ Standards-Version: 3.8.4
 
 Package: libpve-common-perl
 Architecture: all
-Depends: ${perl:Depends} ${misc:Depends}, libclone-perl, libdevel-cycle-perl, libwww-perl, libjson-perl, liblinux-inotify2-perl, libio-stringy-perl, liburi-perl, libstring-shellquote-perl, libnet-ip-perl
+Depends: ${perl:Depends} ${misc:Depends}, libclone-perl, libdevel-cycle-perl, libwww-perl, libjson-perl, liblinux-inotify2-perl, libio-stringy-perl, liburi-perl, libstring-shellquote-perl, libnet-ip-perl, libfilesys-df-perl
 Description: Proxmox VE base library
  This package contains the base library used by other Proxmox VE components.

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index 32f36ac2d6ac9a2fa9fa5cd9ce6bb21bd60ef422..c52a3d0ced935cf1a9c36c059688dd83c70b09f6 100644 (file)
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -8,6 +8,8 @@ use Socket qw(AF_INET AF_INET6 AI_ALL AI_V4MAPPED);
 use IO::Select;
 use File::Basename;
 use File::Path qw(make_path);
+use Filesys::Df (); # don't overwrite our df()
+use IO::Pipe;
 use IO::File;
 use IO::Dir;
 use IPC::Open3;
@@ -790,33 +792,51 @@ sub next_spice_port {
 # NOTE: NFS syscall can't be interrupted, so alarm does 
 # not work to provide timeouts.
 # from 'man nfs': "Only SIGKILL can interrupt a pending NFS operation"
-# So the spawn external 'df' process instead of using
-# Filesys::Df (which uses statfs syscall)
+# So fork() before using Filesys::Df
 sub df {
     my ($path, $timeout) = @_;
 
-    my $cmd = [ 'df', '-P', '-B', '1', $path];
-
     my $res = {
        total => 0,
        used => 0,
        avail => 0,
     };
 
-    my $parser = sub {
-       my $line = shift;
-       if (my ($fsid, $total, $used, $avail) = $line =~
-           m/^(\S+.*)\s+(\d+)\s+(\d+)\s+(\d+)\s+\d+%\s.*$/) {
-           $res = {
-               total => $total,
-               used => $used,
-               avail => $avail,
-           };
+    my $pipe = IO::Pipe->new();
+    my $child = fork();
+    if (!defined($child)) {
+       warn "fork failed: $!\n";
+       return $res;
+    }
+
+    if (!$child) {
+       $pipe->writer();
+       eval {
+           my $df = Filesys::Df::df($path, 1);
+           print {$pipe} "$df->{blocks}\n$df->{used}\n$df->{bavail}\n";
+           $pipe->close();
+       };
+       if (my $err = $@) {
+           warn $err;
+           POSIX::_exit(1);
        }
+       POSIX::_exit(0);
+    }
+
+    $pipe->reader();
+
+    my $readvalues = sub {
+       $res->{total} = int(<$pipe>);
+       $res->{used}  = int(<$pipe>);
+       $res->{avail} = int(<$pipe>);
+    };
+    eval {
+       run_with_timeout($timeout, $readvalues);
     };
-    eval { run_command($cmd, timeout => $timeout, outfunc => $parser); };
     warn $@ if $@;
-
+    $pipe->close();
+    kill('KILL', $child);
+    waitpid($child, 0);
     return $res;
 }