>From 7e27d28b799f0399bbf79074854fa9967ff7752e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A1draig=20Brady?= <address@hidden>
Date: Sat, 19 Mar 2011 01:22:37 +0000
Subject: [PATCH] tests: fix the sparse-fiemap test

* tests/filefrag-extent-compare: Merge adjacent extents in
each list before processing, so we correctly account for
split extents in either list.
* tests/cp/sparse-fiemap: Remove the explicit syncing,
which was only changing way extents were arranged,
and thus working around the extent comparison issue
that was seen on ext4 loop back.
---
 tests/cp/sparse-fiemap        |   11 +++++------
 tests/filefrag-extent-compare |   41 ++++++++++++++++++++++++++++++-----------
 2 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/tests/cp/sparse-fiemap b/tests/cp/sparse-fiemap
index a2460a0..5f0beb7 100755
--- a/tests/cp/sparse-fiemap
+++ b/tests/cp/sparse-fiemap
@@ -69,12 +69,11 @@ for i in $(seq 1 2 21); do
           -e 'for (1..'$j') { sysseek (*F, $n, 1)' \
           -e '&& syswrite (*F, chr($_)x$n) or die "$!"}' > j1 || fail=1
 
-    # Note the explicit fdatasync is used here as
-    # it was seen that `filefrag -s` (FIEMAP_FLAG_SYNC) was
-    # ineffective on ext4 loopback on Linux 2.6.35.10-72.fc14.i686
-    dd if=/dev/null of=j1 conv=notrunc,fdatasync
+    # Note there is an implicit sync performed by cp to
+    # work arounds bugs in EXT4 and BTRFS before Linux 2.6.38
+    # Note also the -s parameter to the second filefrag below
+    # for the same reasons.
     cp --sparse=always j1 j2 || fail=1
-    dd if=/dev/null of=j2 conv=notrunc,fdatasync
 
     cmp j1 j2 || fail=1
     if ! filefrag -v j1 | grep -F extent >/dev/null; then
@@ -98,7 +97,7 @@ for i in $(seq 1 2 21); do
 
       # exclude the physical block numbers; they always differ
       filefrag -v j1 > ff1 || framework_failure
-      filefrag -v j2 > ff2 || framework_failure
+      filefrag -vs j2 > ff2 || framework_failure
       { f ff1; f ff2; } | $PERL $abs_top_srcdir/tests/filefrag-extent-compare ||
         fail=1
     fi
diff --git a/tests/filefrag-extent-compare b/tests/filefrag-extent-compare
index 3c095d5..fa04d9e 100644
--- a/tests/filefrag-extent-compare
+++ b/tests/filefrag-extent-compare
@@ -28,31 +28,50 @@ 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 passed array
+# Discounted extents have length set to 0
+sub merge_extents($)
+{
+  my @e = @{ $_[0] };
+
+  my $a = 1;
+  my $b = 0;
+  while (1)
+    {
+      (!defined $e[$a] || !defined $e[$b])
+        and last;
+      ($e[$b]->{L_BLK} + $e[$b]->{LEN} == $e[$a]->{L_BLK})
+        and $e[$b]->{LEN} += $e[$a]->{LEN}, $e[$a]->{LEN} = 0, next;
+      $b=$a;
+    }
+  continue
+    {
+      ++$a;
+    }
+}
+
+merge_extents(\@a);
+merge_extents(\@b);
+
 my $i = 0;
 my $j = 0;
 while (1)
   {
+    # skip discounted extents
+    defined $a[$i] && $a[$i]->{LEN} == 0 and ++$i, next;
+    defined $b[$j] && $b[$j]->{LEN} == 0 and ++$j, next;
+
     !defined $a[$i] && !defined $b[$j]
       and exit 0;
     defined $a[$i] && defined $b[$j]
       or die "\@a and \@b have different lengths, even after adjustment\n";
     ($a[$i]->{L_BLK} == $b[$j]->{L_BLK}
      && $a[$i]->{LEN} == $b[$j]->{LEN})
-      and next;
-    ($a[$i]->{LEN} < $b[$j]->{LEN}
-     && exists $a[$i+1] && $a[$i]->{LEN} + $a[$i+1]->{LEN} == $b[$j]->{LEN})
-      and ++$i, next;
-    exists $b[$j+1] && $a[$i]->{LEN} == $b[$i]->{LEN} + $b[$i+1]->{LEN}
-      and ++$j, next;
+      and $i++, $j++, next;
     die "differing extent:\n"
       . "  [$i]=$a[$i]->{L_BLK} $a[$i]->{LEN}\n"
       . "  [$j]=$b[$j]->{L_BLK} $b[$j]->{LEN}\n"
   }
-continue
-  {
-    ++$i;
-    ++$j;
-  }
 
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-- 
1.7.4