[PATCH 6/6] xfs/535: Fix test to execute in multi-block directory config

[Chandan Babu R <chandanrlinux@gmail.com>]

xfs/535 attempts to create $srcfile and $dstfile after reduce_max_iextents
error tag is injected. Creation of these files fails when using a multi-block
directory test configuration because,
1. A directory can have a pseudo maximum extent count of 10.
2. In the worst case a directory entry creation operation can consume
   (XFS_DA_NODE_MAXDEPTH + 1 + 1) * (Nr fs blocks in a single directory block)
   extents.
   With 1k fs block size and 4k directory block size, this evaluates to,
   (5 + 1 + 1) * 4
   = 7 * 4
   = 28
   > 10 (Pseudo maximum inode extent count).

This commit fixes the issue by creating $srcfile and $dstfile before injecting
reduce_max_iextents error tag.

Reported-by: Darrick J. Wong <djwong@kernel.org>
Suggested-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
---
 tests/xfs/535     | 11 +++++++++++
 tests/xfs/535.out |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/tests/xfs/535 b/tests/xfs/535
index 2d82624c..f2a8a3a5 100755
--- a/tests/xfs/535
+++ b/tests/xfs/535
@@ -51,6 +51,9 @@ nr_blks=15
 srcfile=${SCRATCH_MNT}/srcfile
 dstfile=${SCRATCH_MNT}/dstfile
 
+touch $srcfile
+touch $dstfile
+
 echo "Inject reduce_max_iextents error tag"
 _scratch_inject_error reduce_max_iextents 1
 
@@ -77,10 +80,18 @@ if (( $nextents > 10 )); then
 	exit 1
 fi
 
+echo "Disable reduce_max_iextents error tag"
+_scratch_inject_error reduce_max_iextents 0
+
 rm $dstfile
 
 echo "* Funshare shared extent"
 
+touch $dstfile
+
+echo "Inject reduce_max_iextents error tag"
+_scratch_inject_error reduce_max_iextents 1
+
 echo "Share the extent with \$dstfile"
 _reflink $srcfile $dstfile >> $seqres.full
 
diff --git a/tests/xfs/535.out b/tests/xfs/535.out
index 4383e921..8f600272 100644
--- a/tests/xfs/535.out
+++ b/tests/xfs/535.out
@@ -6,7 +6,9 @@ Create a $srcfile having an extent of length 15 blocks
 Share the extent with $dstfile
 Buffered write to every other block of $dstfile's shared extent
 Verify $dstfile's extent count
+Disable reduce_max_iextents error tag
 * Funshare shared extent
+Inject reduce_max_iextents error tag
 Share the extent with $dstfile
 Funshare every other block of $dstfile's shared extent
 Verify $dstfile's extent count
-- 
2.29.2