print PID of process locking the URPMI database

2 files changed, 23 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index 0001a9f1..7082ba14 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,8 @@
 - add --download-all option to download all packages before attempting
   to start installation
 - fix priviledge escalation in rurpmi and rurpme (#54568)
+- when the database is locked, print the PID of the processus locking it
+ (#38923, Pascal Terjan)
 
 Version 6.29 - 5 October 2009
 
diff --git a/urpm/lock.pm b/urpm/lock.pm
index 00baec12..687437d3 100644
--- a/urpm/lock.pm
+++ b/urpm/lock.pm
@@ -50,6 +50,18 @@ sub new {
     $lock;
 }
 
+sub get_lock_pid {
+    my ($fh) = @_;
+    my ($dev,$ino,undef) = stat($fh);
+    my $major = int($dev/256);
+    my $minor = $dev % 256;
+    my $fileid = sprintf("%02x:%02x:%d",$major,$minor,$ino);
+    open(LOCKS, "/proc/locks") || return;
+    my @locks = <LOCKS>;
+    close(LOCKS); 
+    foreach (@locks) { /FLOCK.*WRITE\s*(\d+)\s*$fileid\s/ && return $1 };
+}
+
 sub _lock {
     my ($lock, $b_exclusive, $b_wait) = @_;
     $b_exclusive ||= '';
@@ -63,7 +75,15 @@ sub _lock {
 	    $lock->{info}(N("%s database is locked. Waiting...", $lock->{db_name}));
 	    flock($lock->{fh}, $mode) or $lock->{fatal}(N("aborting"));
 	} else {
-	    $lock->{fatal}(N("%s database is locked (another program is already using it)", $lock->{db_name}));
+	    my $pid = get_lock_pid($lock->{fh});
+	    if($pid) {
+		my $name = urpm::util::cat_("/proc/$pid/cmdline");
+		$name =~ tr/\0/ /;
+		$name =~ s/ *$//;
+	        $lock->{fatal}(N("%s database is locked, process %d is already using it", $lock->{db_name}, $pid).($name?" ($name)":""));
+	    } else {
+	        $lock->{fatal}(N("%s database is locked (another program is already using it)", $lock->{db_name}));
+	    }
 	}
     }
     $lock->{locked} = 1;