[PATCH 2/2] common/rc: handle xfs_io copy_range when copy_file_range syscall isn't available

[Luis Henriques <lhenriques@suse.com>]

_require_xfs_io_command() isn't handling the case where the copy_file_range
syscall isn't available.  Unfortunately, old versions of xfs_io don't
handle it correctly either and the test will succeed with an empty file.

To fix this function, we need to add two checks:

1) for old xfs_io versions, fail if the test seems to succeed (no output)
   but the file created is empty,
2) for newer versions, use the error returned.

Signed-off-by: Luis Henriques <lhenriques@suse.com>
---
 common/rc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/common/rc b/common/rc
index 2972f89e9527..aad065cb2ade 100644
--- a/common/rc
+++ b/common/rc
@@ -2146,6 +2146,10 @@ _require_xfs_io_command()
 		$XFS_IO_PROG -F -f -c "pwrite 0 4k" $testfile > /dev/null 2>&1
 		testio=`$XFS_IO_PROG -F -f -c "copy_range $testfile" $testcopy 2>&1`
 		rm -f $testcopy > /dev/null 2>&1
+		[ -z "$testio" -a ! -s "$testcopy" ] && \
+			_notrun "xfs_io $command support is missing"
+		echo $testio | egrep -q "Function not implemented" && \
+			_notrun "xfs_io $command support is missing"
 		;;
 	"falloc" )
 		testio=`$XFS_IO_PROG -F -f -c "falloc $param 0 1m" $testfile 2>&1`