1 files changed, 85 insertions, 0 deletions
diff --git a/tests/filefrag-extent-compare b/tests/filefrag-extent-compare
new file mode 100644
index 0000000..155e7ff
--- /dev/null
+++ b/tests/filefrag-extent-compare
@@ -0,0 +1,85 @@
+eval '(exit $?0)' && eval 'exec perl -wS "$0" ${1+"$@"}'
+  & eval 'exec perl -wS "$0" $argv:q'
+    if 0;
+# Determine whether two files have the same extents by comparing
+# the logical block numbers and lengths from filefrag -v for each.
+
+# Invoke like this:
+# This helper function, f, extracts logical block number and lengths.
+# f() { awk '/^ *[0-9]/ {printf "%d %d ",$2,NF<5?$NF:$5} END {print ""}'; }
+# { filefrag -v j1 | f; filefrag -v j2 | f; } | ./filefrag-extent-compare
+
+use warnings;
+use strict;
+(my $ME = $0) =~ s|.*/||;
+
+my @line = <>;
+my $n_lines = @line;
+$n_lines == 2
+  or die "$ME: expected exactly two input lines; got $n_lines\n";
+
+my @A = split ' ', $line[0];
+my @B = split ' ', $line[1];
+@A % 2 || @B % 2
+  and die "$ME: unexpected input: odd number of numbers; expected even\n";
+
+my @a;
+my @b;
+foreach my $i (0..@A/2-1) { $a[$i] = { L_BLK => $A[2*$i], LEN => $A[2*$i+1] } };
+foreach my $i (0..@B/2-1) { $b[$i] = { L_BLK => $B[2*$i], LEN => $B[2*$i+1] } };
+
+# Merge adjacent extents in array E.
+sub merge_extents($)
+{
+  my ($e) = @_;
+
+  my $i = 0;
+  while (1)
+    {
+      !defined $e->[$i+1]
+        and last;
+      $e->[$i]->{L_BLK} + $e->[$i]->{LEN} != $e->[$i+1]->{L_BLK}
+        and ++$i, next;
+
+      $e->[$i]->{LEN} += $e->[$i+1]->{LEN};
+      # Remove $e->[$i+1]
+      splice @$e, $i+1, 1;
+    }
+}
+
+merge_extents \@a;
+merge_extents \@b;
+
+@a == @b
+  or die "$ME: extent counts differ, even after adjustment\n";
+
+my $i = 0;
+while (defined $a[$i])
+  {
+    my $start_match = $a[$i]->{L_BLK} == $b[$i]->{L_BLK};
+    my $len_match = $a[$i]->{LEN} == $b[$i]->{LEN};
+    if ( ! ($start_match && ($len_match || $i == (@a - 1))))
+      {
+        # On XFS on Linux kernel 2.6.38, it was seen that the size of the
+        # last extent can vary, and can extend beyond the length of the file.
+        # So we ignore the length of the last extent, because if the
+        # file is the wrong length we'll get failures elsewhere.
+        die "$ME: differing extent:\n"
+          . "  [$i]=$a[$i]->{L_BLK} $a[$i]->{LEN}\n"
+            . "  [$i]=$b[$i]->{L_BLK} $b[$i]->{LEN}\n";
+      }
+    $i++;
+  }
+
+### Setup "GNU" style for perl-mode and cperl-mode.
+## Local Variables:
+## mode: perl
+## perl-indent-level: 2
+## perl-continued-statement-offset: 2
+## perl-continued-brace-offset: 0
+## perl-brace-offset: 0
+## perl-brace-imaginary-offset: 0
+## perl-label-offset: -2
+## perl-extra-newline-before-brace: t
+## perl-merge-trailing-else: nil
+## End: