[PATCH 2/2] fstests: btrfs/177 fix for nodesize 64K and type single

[Anand Jain <anand.jain@oracle.com>]

In the blockgroup type single with nodesize 64K, the relocation of the bg
containing the swapfile is not being attempted during the resize. So due
to this the resize is successful and does not generate the required
'Text file busy' error message as in the golden output and so the testcase
fails.

Fix this by replacing the mkfs created chunk with the bigger kernel created
chunk using balance, and then fill it up to the full. Upsize to 3x of fssize
once instead of first to 2G and then to 3G. Also drop the unnecessary downsize
to 2G step.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 tests/btrfs/177     | 34 +++++++++++++++++++++++-----------
 tests/btrfs/177.out |  6 ++----
 2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/tests/btrfs/177 b/tests/btrfs/177
index a627c2ab1666..67f8dbc1a590 100755
--- a/tests/btrfs/177
+++ b/tests/btrfs/177
@@ -39,30 +39,42 @@ devsize=$(blockdev --getsize64 $SCRATCH_DEV)
 [ "$devsize" -lt "$minsize" ] && \
 	_notrun "Scratch device $SCRATCH_DEV $devsize must be at least $minsize"
 
-# First, create a 1GB filesystem and fill it up.
-_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full 2>&1
+# First, create a 1GB filesystem.
+fssize=$((1024 * 1024 * 1024))
+_scratch_mkfs_sized $fssize >> $seqres.full 2>&1
 _scratch_mount
-dd if=/dev/zero of="$SCRATCH_MNT/fill" bs=1024k >> $seqres.full 2>&1
-# Now add more space and create a swap file. We know that the first 1GB of the
-# filesystem was used, so the swap file must be in the new part of the
+
+# Create a small file and run balance so we shall deal with the chunk
+# size as allocated by the kernel, mkfs allocated chunks are smaller.
+dd if=/dev/zero of="$SCRATCH_MNT/fill" bs=4096 count=1 >> $seqres.full 2>&1
+_run_btrfs_balance_start "$SCRATCH_MNT"
+
+# Now fill it up.
+dd if=/dev/zero of="$SCRATCH_MNT/refill" bs=4096 >> $seqres.full 2>&1
+
+# Now add more space and create a swap file. We know that the first $fssize
+# of the filesystem was used, so the swap file must be in the new part of the
 # filesystem.
-$BTRFS_UTIL_PROG filesystem resize 2G "$SCRATCH_MNT" | _filter_scratch
+$BTRFS_UTIL_PROG filesystem resize $((3 * fssize)) "$SCRATCH_MNT" | \
+							_filter_scratch
 _format_swapfile "$swapfile" $((32 * 1024 * 1024))
 swapon "$swapfile"
-# Add even more space which we know is unused.
-$BTRFS_UTIL_PROG filesystem resize 3G "$SCRATCH_MNT" | _filter_scratch
+
 # Free up the first 1GB of the filesystem.
 rm -f "$SCRATCH_MNT/fill"
+rm -f "$SCRATCH_MNT/refill"
+
 # Get rid of empty block groups and also make sure that balance skips block
 # groups containing active swap files.
 _run_btrfs_balance_start "$SCRATCH_MNT"
-# Shrink away the unused space.
-$BTRFS_UTIL_PROG filesystem resize 2G "$SCRATCH_MNT" | _filter_scratch
+
 # Try to shrink away the area occupied by the swap file, which should fail.
 $BTRFS_UTIL_PROG filesystem resize 1G "$SCRATCH_MNT" 2>&1 | grep -o "Text file busy"
+
 swapoff "$swapfile"
+
 # It should work again after swapoff.
-$BTRFS_UTIL_PROG filesystem resize 1G "$SCRATCH_MNT" | _filter_scratch
+$BTRFS_UTIL_PROG filesystem resize $fssize "$SCRATCH_MNT" | _filter_scratch
 
 status=0
 exit
diff --git a/tests/btrfs/177.out b/tests/btrfs/177.out
index 6ced01da9f61..63aca0e5362d 100644
--- a/tests/btrfs/177.out
+++ b/tests/btrfs/177.out
@@ -1,6 +1,4 @@
 QA output created by 177
-Resize 'SCRATCH_MNT' of '2G'
-Resize 'SCRATCH_MNT' of '3G'
-Resize 'SCRATCH_MNT' of '2G'
+Resize 'SCRATCH_MNT' of '3221225472'
 Text file busy
-Resize 'SCRATCH_MNT' of '1G'
+Resize 'SCRATCH_MNT' of '1073741824'
-- 
2.18.1