The $dread_pid refers to the while-true-do loop, wait for $dread_pid
doesn't mean the xfs_io direct read process is already dead,
sometimes xfs_io process is still running and blocking
_scratch_unmount.
Fix it by making the direct read does a fixed number of loop and
break out the second mmap-fpunch loop if the first loop exits. At
this point we're sure that there's no unfinished background process
blocking the umount.
Reviewed-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file >> $seqres.full
# run a background dio read to a hole in a loop
-while true; do
+for i in `seq 0 999`; do
$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file > /dev/null 2>&1
done &
dread_pid=$!
# run mapped write to the same hole as dio read
-for i in `seq 0 999`; do
+# loop until background dio read exits
+while kill -s 0 $dread_pid >/dev/null 2>&1; do
$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
> /dev/null
$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file > /dev/null
done
-kill -9 $dread_pid > /dev/null 2>&1
wait $dread_pid > /dev/null 2>&1
echo "Silence is golden"