xfstests: btrfs/011 improvement for compressed filesystems

Josef noticed that using /dev/zero to generate most of the test
data doesn't work if someone overrides the mount options to
enable compression. The test that performs a cancellation failed
because the replace operation was already finished when the
cancel request was executed.

Since /dev/urandom is too slow to generate multiple GB, the
way how the filesystem data is generated is completely changed
with this patch. Now /dev/urandom is used to generate one 1MB
file and this file is copied up to 2048 times. /dev/zero is no
longer used.

The runtime of the test is about the same as before. Compression
works now, online duplication will again cause issues, but
we don't have online duplication today.

Reported-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Reviewed-by: Jan Schmidt <list.xfs@jan-o-sch.net>
Signed-off-by: Rich Johnston <rjohnston@sgi.com>

diff --git a/tests/btrfs/011 b/tests/btrfs/011
index c8b4aaca83a61f6f90aaacf0d27faed20c413da9..71ff3deb96dfa60998c6d355403b632c8ce71264 100755 (executable)
--- a/tests/btrfs/011
+++ b/tests/btrfs/011
@@ -78,6 +78,7 @@ workout()
        local quick="$4"
        local source_dev="`echo ${SCRATCH_DEV_POOL} | awk '{print $1}'`"
        local target_dev="`echo ${SCRATCH_DEV_POOL} | awk '{print $NF}'`"
+       local fssize
 
        if [ "`echo $SCRATCH_DEV_POOL | wc -w`" -lt `expr $num_devs4raid + 1` ]; then
                echo "Skip workout $1 $2 $3 $4" >> $seqres.full
@@ -107,33 +108,46 @@ workout()
                _notrun "Different device sizes detected"
        fi
 
+       if [ `$BTRFS_SHOW_SUPER_PROG $SCRATCH_DEV | grep dev_item.total_bytes | awk '{print $2}'` -lt 2500000000 ]; then
+               _notrun "device size too small"
+       fi
+
        _scratch_mount
 
-       # Generate 500 times 20K extents in the data chunk and fill up
-       # metadata with inline extents. Ignore ENOSPC.
+       # Generate metadata and some minimal user data, generate 500 times
+       # 20K extents in the data chunk and fill up metadata with inline
+       # extents.
        for i in `seq 1 500`; do
                dd if=/dev/urandom of=$SCRATCH_MNT/l$i bs=16385 count=1
                dd if=/dev/urandom of=$SCRATCH_MNT/s$i bs=3800 count=1
        done > /dev/null 2>&1
 
+       # /dev/urandom is slow but has the benefit that the generated
+       # contents does not shrink during compression.
+       # Generate a template once and quickly copy it multiple times.
+       # Obviously with online deduplication this will not work anymore.
+       dd if=/dev/urandom of=$SCRATCH_MNT/t0 bs=1M count=1 > /dev/null 2>&1
+
        if [ "${quick}Q" = "thoroughQ" ]; then
                # The intention of this "thorough" test is to increase
                # the probability of random errors, in particular in
                # conjunction with the background noise generator and
-               # a sync call while the replace operation in ongoing.
-               # Unfortunately it takes quite some time to generate
-               # the test filesystem, therefore most data consists out
-               # of zeros although this data is not very useful for
-               # detecting misplaced read/write requests.
-               # Ignore ENOSPC, it's not a problem..
-               dd if=/dev/urandom of=$SCRATCH_MNT/r bs=1M count=200 >> $seqres.full 2>&1 &
-               dd if=/dev/zero of=$SCRATCH_MNT/0 bs=1M count=2000 >> $seqres.full 2>&1
-               wait
+               # a sync call while the replace operation is ongoing.
+               fssize=2048
        elif [ "${with_cancel}Q" = "cancelQ" ]; then
-               # produce some data to prevent that the replace operation
-               # finishes before the cancel request is started
-               dd if=/dev/zero of=$SCRATCH_MNT/0 bs=1M count=1000 >> $seqres.full 2>&1
+               # The goal is to produce enough data to prevent that the
+               # replace operation finishes before the cancel request
+               # is started.
+               fssize=1024
+       else
+               fssize=64
        fi
+
+       # since the available size was tested before, do not tolerate
+       # any failures
+       for i in `seq $fssize`; do
+               cp $SCRATCH_MNT/t0 $SCRATCH_MNT/t$i || _fail "cp failed"
+       done > /dev/null 2>> $seqres.full
        sync; sync
 
        btrfs_replace_test $source_dev $target_dev "" $with_cancel $quick
@@ -214,7 +228,7 @@ btrfs_replace_test()
                # before the status is printed
                $BTRFS_UTIL_PROG replace status $SCRATCH_MNT > $tmp.tmp 2>&1
                cat $tmp.tmp >> $seqres.full
-               grep -q canceled $tmp.tmp || _fail "btrfs replace status failed"
+               grep -q canceled $tmp.tmp || _fail "btrfs replace status (canceled) failed"
        else
                if [ "${quick}Q" = "thoroughQ" ]; then
                        # On current hardware, the thorough test runs
@@ -226,7 +240,7 @@ btrfs_replace_test()
 
                $BTRFS_UTIL_PROG replace status $SCRATCH_MNT > $tmp.tmp 2>&1
                cat $tmp.tmp >> $seqres.full
-               grep -q finished $tmp.tmp || _fail "btrfs replace status failed"
+               grep -q finished $tmp.tmp || _fail "btrfs replace status (finished) failed"
        fi
 
        if ps -p $noise_pid | grep -q $noise_pid; then